mongoose.cc

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#include "mongoose.h"
#ifdef MG_MODULE_LINES
#line 1 "./src/internal.h"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#ifndef CS_MONGOOSE_SRC_INTERNAL_H_
#define CS_MONGOOSE_SRC_INTERNAL_H_

#ifndef MG_MALLOC
#define MG_MALLOC malloc
#endif

#ifndef MG_CALLOC
#define MG_CALLOC calloc
#endif

#ifndef MG_REALLOC
#define MG_REALLOC realloc
#endif

#ifndef MG_FREE
#define MG_FREE free
#endif

#ifndef MBUF_REALLOC
#define MBUF_REALLOC MG_REALLOC
#endif

#ifndef MBUF_FREE
#define MBUF_FREE MG_FREE
#endif

#define MG_SET_PTRPTR(_ptr, _v) \
do {                          \
if (_ptr) *(_ptr) = _v;     \
} while (0)

#ifndef MG_INTERNAL
#define MG_INTERNAL static
#endif

#ifdef PICOTCP
#define NO_LIBC
#define MG_DISABLE_FILESYSTEM
#define MG_DISABLE_POPEN
#define MG_DISABLE_CGI
#define MG_DISABLE_DIRECTORY_LISTING
#define MG_DISABLE_SOCKETPAIR
#define MG_DISABLE_PFS
#endif

/* Amalgamated: #include "mongoose/src/net.h" */
/* Amalgamated: #include "mongoose/src/http.h" */

#define MG_CTL_MSG_MESSAGE_SIZE 8192

/* internals that need to be accessible in unit tests */
MG_INTERNAL struct mg_connection *mg_do_connect(struct mg_connection *nc,
                                                int proto,
                                                union socket_address *sa);

MG_INTERNAL int mg_parse_address(const char *str, union socket_address *sa,
                                 int *proto, char *host, size_t host_len);
MG_INTERNAL void mg_call(struct mg_connection *nc,
                         mg_event_handler_t ev_handler, int ev, void *ev_data);
void mg_forward(struct mg_connection *from, struct mg_connection *to);
MG_INTERNAL void mg_add_conn(struct mg_mgr *mgr, struct mg_connection *c);
MG_INTERNAL void mg_remove_conn(struct mg_connection *c);
MG_INTERNAL struct mg_connection *mg_create_connection(
                                                       struct mg_mgr *mgr, mg_event_handler_t callback,
                                                       struct mg_add_sock_opts opts);
#ifndef MG_DISABLE_FILESYSTEM
MG_INTERNAL int mg_uri_to_local_path(struct http_message *hm,
                                     const struct mg_serve_http_opts *opts,
                                     char **local_path,
                                     struct mg_str *remainder);
#endif
#ifdef _WIN32
/* Retur value is the same as for MultiByteToWideChar. */
int to_wchar(const char *path, wchar_t *wbuf, size_t wbuf_len);
#endif

/*
 * Reassemble the content of the buffer (buf, blen) which should be
 * in the HTTP chunked encoding, by collapsing data chunks to the
 * beginning of the buffer.
 *
 * If chunks get reassembled, modify hm->body to point to the reassembled
 * body and fire MG_EV_HTTP_CHUNK event. If handler sets MG_F_DELETE_CHUNK
 * in nc->flags, delete reassembled body from the mbuf.
 *
 * Return reassembled body size.
 */
MG_INTERNAL size_t mg_handle_chunked(struct mg_connection *nc,
                                     struct http_message *hm, char *buf,
                                     size_t blen);

#ifndef MG_DISABLE_FILESYSTEM
MG_INTERNAL time_t mg_parse_date_string(const char *datetime);
MG_INTERNAL int mg_is_not_modified(struct http_message *hm, cs_stat_t *st);
#endif

struct ctl_msg {
   mg_event_handler_t callback;
   char message[MG_CTL_MSG_MESSAGE_SIZE];
};

#ifndef MG_DISABLE_MQTT
struct mg_mqtt_message;
MG_INTERNAL int parse_mqtt(struct mbuf *io, struct mg_mqtt_message *mm);
#endif

/* Forward declarations for testing. */
extern void *(*test_malloc)(size_t size);
extern void *(*test_calloc)(size_t count, size_t size);

#endif /* CS_MONGOOSE_SRC_INTERNAL_H_ */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/base64.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#ifndef EXCLUDE_COMMON

/* Amalgamated: #include "common/base64.h" */
#include <string.h>

/* ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/ */

#define NUM_UPPERCASES ('Z' - 'A' + 1)
#define NUM_LETTERS (NUM_UPPERCASES * 2)
#define NUM_DIGITS ('9' - '0' + 1)

/*
 * Emit a base64 code char.
 *
 * Doesn't use memory, thus it's safe to use to safely dump memory in crashdumps
 */
static void cs_base64_emit_code(struct cs_base64_ctx *ctx, int v) {
   if (v < NUM_UPPERCASES) {
      ctx->b64_putc(v + 'A', ctx->user_data);
   } else if (v < (NUM_LETTERS)) {
      ctx->b64_putc(v - NUM_UPPERCASES + 'a', ctx->user_data);
   } else if (v < (NUM_LETTERS + NUM_DIGITS)) {
      ctx->b64_putc(v - NUM_LETTERS + '0', ctx->user_data);
   } else {
      ctx->b64_putc(v - NUM_LETTERS - NUM_DIGITS == 0 ? '+' : '/',
                    ctx->user_data);
   }
}

static void cs_base64_emit_chunk(struct cs_base64_ctx *ctx) {
   int a, b, c;
   
   a = ctx->chunk[0];
   b = ctx->chunk[1];
   c = ctx->chunk[2];
   
   cs_base64_emit_code(ctx, a >> 2);
   cs_base64_emit_code(ctx, ((a & 3) << 4) | (b >> 4));
   if (ctx->chunk_size > 1) {
      cs_base64_emit_code(ctx, (b & 15) << 2 | (c >> 6));
   }
   if (ctx->chunk_size > 2) {
      cs_base64_emit_code(ctx, c & 63);
   }
}

void cs_base64_init(struct cs_base64_ctx *ctx, cs_base64_putc_t b64_putc,
                    void *user_data) {
   ctx->chunk_size = 0;
   ctx->b64_putc = b64_putc;
   ctx->user_data = user_data;
}

void cs_base64_update(struct cs_base64_ctx *ctx, const char *str, size_t len) {
   const unsigned char *src = (const unsigned char *) str;
   size_t i;
   for (i = 0; i < len; i++) {
      ctx->chunk[ctx->chunk_size++] = src[i];
      if (ctx->chunk_size == 3) {
         cs_base64_emit_chunk(ctx);
         ctx->chunk_size = 0;
      }
   }
}

void cs_base64_finish(struct cs_base64_ctx *ctx) {
   if (ctx->chunk_size > 0) {
      int i;
      memset(&ctx->chunk[ctx->chunk_size], 0, 3 - ctx->chunk_size);
      cs_base64_emit_chunk(ctx);
      for (i = 0; i < (3 - ctx->chunk_size); i++) {
         ctx->b64_putc('=', ctx->user_data);
      }
   }
}

#define BASE64_ENCODE_BODY                                                \
static const char *b64 =                                                \
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; \
int i, j, a, b, c;                                                      \
\
for (i = j = 0; i < src_len; i += 3) {                                  \
a = src[i];                                                           \
b = i + 1 >= src_len ? 0 : src[i + 1];                                \
c = i + 2 >= src_len ? 0 : src[i + 2];                                \
\
BASE64_OUT(b64[a >> 2]);                                              \
BASE64_OUT(b64[((a & 3) << 4) | (b >> 4)]);                           \
if (i + 1 < src_len) {                                                \
BASE64_OUT(b64[(b & 15) << 2 | (c >> 6)]);                          \
}                                                                     \
if (i + 2 < src_len) {                                                \
BASE64_OUT(b64[c & 63]);                                            \
}                                                                     \
}                                                                       \
\
while (j % 4 != 0) {                                                    \
BASE64_OUT('=');                                                      \
}                                                                       \
BASE64_FLUSH()

#define BASE64_OUT(ch) \
do {                 \
dst[j++] = (ch);   \
} while (0)

#define BASE64_FLUSH() \
do {                 \
dst[j++] = '\0';   \
} while (0)

void cs_base64_encode(const unsigned char *src, int src_len, char *dst) {
   BASE64_ENCODE_BODY;
}

#undef BASE64_OUT
#undef BASE64_FLUSH

#ifndef CS_DISABLE_STDIO
#define BASE64_OUT(ch)      \
do {                      \
fprintf(f, "%c", (ch)); \
j++;                    \
} while (0)

#define BASE64_FLUSH()

void cs_fprint_base64(FILE *f, const unsigned char *src, int src_len) {
   BASE64_ENCODE_BODY;
}

#undef BASE64_OUT
#undef BASE64_FLUSH
#endif /* !CS_DISABLE_STDIO */

/* Convert one byte of encoded base64 input stream to 6-bit chunk */
static unsigned char from_b64(unsigned char ch) {
   /* Inverse lookup map */
   static const unsigned char tab[128] = {
      255, 255, 255, 255,
      255, 255, 255, 255, /*  0 */
      255, 255, 255, 255,
      255, 255, 255, 255, /*  8 */
      255, 255, 255, 255,
      255, 255, 255, 255, /*  16 */
      255, 255, 255, 255,
      255, 255, 255, 255, /*  24 */
      255, 255, 255, 255,
      255, 255, 255, 255, /*  32 */
      255, 255, 255, 62,
      255, 255, 255, 63, /*  40 */
      52,  53,  54,  55,
      56,  57,  58,  59, /*  48 */
      60,  61,  255, 255,
      255, 200, 255, 255, /*  56   '=' is 200, on index 61 */
      255, 0,   1,   2,
      3,   4,   5,   6, /*  64 */
      7,   8,   9,   10,
      11,  12,  13,  14, /*  72 */
      15,  16,  17,  18,
      19,  20,  21,  22, /*  80 */
      23,  24,  25,  255,
      255, 255, 255, 255, /*  88 */
      255, 26,  27,  28,
      29,  30,  31,  32, /*  96 */
      33,  34,  35,  36,
      37,  38,  39,  40, /*  104 */
      41,  42,  43,  44,
      45,  46,  47,  48, /*  112 */
      49,  50,  51,  255,
      255, 255, 255, 255, /*  120 */
   };
   return tab[ch & 127];
}

int cs_base64_decode(const unsigned char *s, int len, char *dst) {
   unsigned char a, b, c, d;
   int orig_len = len;
   while (len >= 4 && (a = from_b64(s[0])) != 255 &&
          (b = from_b64(s[1])) != 255 && (c = from_b64(s[2])) != 255 &&
          (d = from_b64(s[3])) != 255) {
      s += 4;
      len -= 4;
      if (a == 200 || b == 200) break; /* '=' can't be there */
      *dst++ = a << 2 | b >> 4;
      if (c == 200) break;
      *dst++ = b << 4 | c >> 2;
      if (d == 200) break;
      *dst++ = c << 6 | d;
   }
   *dst = 0;
   return orig_len - len;
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/cs_dbg.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

/* Amalgamated: #include "common/cs_dbg.h" */

#include <stdarg.h>
#include <stdio.h>

/* Amalgamated: #include "common/cs_time.h" */

enum cs_log_level cs_log_level =
#ifdef CS_ENABLE_DEBUG
LL_VERBOSE_DEBUG;
#else
LL_ERROR;
#endif

#ifndef CS_DISABLE_STDIO

FILE *cs_log_file = NULL;

#ifdef CS_LOG_TS_DIFF
double cs_log_ts;
#endif

void cs_log_print_prefix(const char *func) {
   if (cs_log_file == NULL) cs_log_file = stderr;
   fprintf(cs_log_file, "%-20s ", func);
#ifdef CS_LOG_TS_DIFF
   {
   double now = cs_time();
   fprintf(cs_log_file, "%7u ", (unsigned int) ((now - cs_log_ts) * 1000000));
   cs_log_ts = now;
   }
#endif
}

void cs_log_printf(const char *fmt, ...) {
   va_list ap;
   va_start(ap, fmt);
   vfprintf(cs_log_file, fmt, ap);
   va_end(ap);
   fputc('\n', cs_log_file);
   fflush(cs_log_file);
}

void cs_log_set_file(FILE *file) {
   cs_log_file = file;
}

#endif /* !CS_DISABLE_STDIO */

void cs_log_set_level(enum cs_log_level level) {
   cs_log_level = level;
#if defined(CS_LOG_TS_DIFF) && !defined(CS_DISABLE_STDIO)
   cs_log_ts = cs_time();
#endif
}
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/cs_dirent.h"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#ifndef CS_COMMON_CS_DIRENT_H_
#define CS_COMMON_CS_DIRENT_H_

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
   
#ifdef CS_ENABLE_SPIFFS
   
#include <spiffs.h>
   
   typedef struct {
      spiffs_DIR dh;
      struct spiffs_dirent de;
   } DIR;
   
#define d_name name
#define dirent spiffs_dirent
   
   int rmdir(const char *path);
   int mkdir(const char *path, mode_t mode);
   
#endif
   
#if defined(_WIN32)
   struct dirent {
      char d_name[MAX_PATH];
   };
   
   typedef struct DIR {
      HANDLE handle;
      WIN32_FIND_DATAW info;
      struct dirent result;
   } DIR;
#endif
   
#if defined(_WIN32) || defined(CS_ENABLE_SPIFFS)
   DIR *opendir(const char *dir_name);
   int closedir(DIR *dir);
   struct dirent *readdir(DIR *dir);
#endif
   
#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CS_COMMON_CS_DIRENT_H_ */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/cs_dirent.c"
#endif
/*
 * Copyright (c) 2015 Cesanta Software Limited
 * All rights reserved
 */

#ifndef EXCLUDE_COMMON

/* Amalgamated: #include "common/cs_dirent.h" */

/*
 * This file contains POSIX opendir/closedir/readdir API implementation
 * for systems which do not natively support it (e.g. Windows).
 */

#ifndef MG_FREE
#define MG_FREE free
#endif

#ifndef MG_MALLOC
#define MG_MALLOC malloc
#endif

#ifdef _WIN32
DIR *opendir(const char *name) {
   DIR *dir = NULL;
   wchar_t wpath[MAX_PATH];
   DWORD attrs;
   
   if (name == NULL) {
      SetLastError(ERROR_BAD_ARGUMENTS);
   } else if ((dir = (DIR *) MG_MALLOC(sizeof(*dir))) == NULL) {
      SetLastError(ERROR_NOT_ENOUGH_MEMORY);
   } else {
      to_wchar(name, wpath, ARRAY_SIZE(wpath));
      attrs = GetFileAttributesW(wpath);
      if (attrs != 0xFFFFFFFF && (attrs & FILE_ATTRIBUTE_DIRECTORY)) {
         (void) wcscat(wpath, L"\\*");
         dir->handle = FindFirstFileW(wpath, &dir->info);
         dir->result.d_name[0] = '\0';
      } else {
         MG_FREE(dir);
         dir = NULL;
      }
   }
   
   return dir;
}

int closedir(DIR *dir) {
   int result = 0;
   
   if (dir != NULL) {
      if (dir->handle != INVALID_HANDLE_VALUE)
         result = FindClose(dir->handle) ? 0 : -1;
      MG_FREE(dir);
   } else {
      result = -1;
      SetLastError(ERROR_BAD_ARGUMENTS);
   }
   
   return result;
}

struct dirent *readdir(DIR *dir) {
   struct dirent *result = NULL;
   
   if (dir) {
      if (dir->handle != INVALID_HANDLE_VALUE) {
         result = &dir->result;
         (void) WideCharToMultiByte(CP_UTF8, 0, dir->info.cFileName, -1,
                                    result->d_name, sizeof(result->d_name), NULL,
                                    NULL);
         
         if (!FindNextFileW(dir->handle, &dir->info)) {
            (void) FindClose(dir->handle);
            dir->handle = INVALID_HANDLE_VALUE;
         }
         
      } else {
         SetLastError(ERROR_FILE_NOT_FOUND);
      }
   } else {
      SetLastError(ERROR_BAD_ARGUMENTS);
   }
   
   return result;
}
#endif

#ifdef CS_ENABLE_SPIFFS

DIR *opendir(const char *dir_name) {
   DIR *dir = NULL;
   extern spiffs fs;
   
   if (dir_name != NULL && (dir = (DIR *) malloc(sizeof(*dir))) != NULL &&
       SPIFFS_opendir(&fs, (char *) dir_name, &dir->dh) == NULL) {
      free(dir);
      dir = NULL;
   }
   
   return dir;
}

int closedir(DIR *dir) {
   if (dir != NULL) {
      SPIFFS_closedir(&dir->dh);
      free(dir);
   }
   return 0;
}

struct dirent *readdir(DIR *dir) {
   return SPIFFS_readdir(&dir->dh, &dir->de);
}

/* SPIFFs doesn't support directory operations */
int rmdir(const char *path) {
   (void) path;
   return ENOTDIR;
}

int mkdir(const char *path, mode_t mode) {
   (void) path;
   (void) mode;
   /* for spiffs supports only root dir, which comes from mongoose as '.' */
   return (strlen(path) == 1 && *path == '.') ? 0 : ENOTDIR;
}

#endif /* CS_ENABLE_SPIFFS */

#endif /* EXCLUDE_COMMON */

/* ISO C requires a translation unit to contain at least one declaration */
typedef int cs_dirent_dummy;
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/cs_time.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

/* Amalgamated: #include "common/cs_time.h" */

#ifndef _WIN32
#include <stddef.h>
#if !defined(CS_PLATFORM) || \
(CS_PLATFORM != CS_P_CC3200 && CS_PLATFORM != CS_P_MSP432)
#include <sys/time.h>
#endif
#else
#include <windows.h>
#endif

double cs_time() {
   double now;
#ifndef _WIN32
   struct timeval tv;
   if (gettimeofday(&tv, NULL /* tz */) != 0) return 0;
   now = (double) tv.tv_sec + (((double) tv.tv_usec) / 1000000.0);
#else
   now = GetTickCount() / 1000.0;
#endif
   return now;
}
#ifdef MG_MODULE_LINES
#line 1 "./src/../deps/frozen/frozen.c"
#endif
/*
 * Copyright (c) 2004-2013 Sergey Lyubka <valenok@gmail.com>
 * Copyright (c) 2013 Cesanta Software Limited
 * All rights reserved
 *
 * This library is dual-licensed: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. For the terms of this
 * license, see <http: *www.gnu.org/licenses/>.
 *
 * You are free to use this library under the terms of the GNU General
 * Public License, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * Alternatively, you can license this library under a commercial
 * license, as set out in <http://cesanta.com/products.html>.
 */

#ifndef _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS /* Disable deprecation warning in VS2005+ */
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
/* Amalgamated: #include "frozen.h" */

#ifdef _WIN32
#define snprintf _snprintf
#endif

#ifndef FROZEN_REALLOC
#define FROZEN_REALLOC realloc
#endif

#ifndef FROZEN_FREE
#define FROZEN_FREE free
#endif

struct frozen {
   const char *end;
   const char *cur;
   struct json_token *tokens;
   int max_tokens;
   int num_tokens;
   int do_realloc;
};

static int parse_object(struct frozen *f);
static int parse_value(struct frozen *f);

#define EXPECT(cond, err_code)      \
do {                              \
if (!(cond)) return (err_code); \
} while (0)
#define TRY(expr)          \
do {                     \
int _n = expr;         \
if (_n < 0) return _n; \
} while (0)
#define END_OF_STRING (-1)

static int left(const struct frozen *f) {
   return f->end - f->cur;
}

static int is_space(int ch) {
   return ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n';
}

static void skip_whitespaces(struct frozen *f) {
   while (f->cur < f->end && is_space(*f->cur)) f->cur++;
}

static int cur(struct frozen *f) {
   skip_whitespaces(f);
   return f->cur >= f->end ? END_OF_STRING : *(unsigned char *) f->cur;
}

static int test_and_skip(struct frozen *f, int expected) {
   int ch = cur(f);
   if (ch == expected) {
      f->cur++;
      return 0;
   }
   return ch == END_OF_STRING ? JSON_STRING_INCOMPLETE : JSON_STRING_INVALID;
}

static int test_no_skip(struct frozen *f, int expected) {
   int ch = cur(f);
   if (ch == expected) {
      return 0;
   }
   return ch == END_OF_STRING ? JSON_STRING_INCOMPLETE : JSON_STRING_INVALID;
}

static int is_alpha(int ch) {
   return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z');
}

static int is_digit(int ch) {
   return ch >= '0' && ch <= '9';
}

static int is_hex_digit(int ch) {
   return is_digit(ch) || (ch >= 'a' && ch <= 'f') || (ch >= 'A' && ch <= 'F');
}

static int get_escape_len(const char *s, int len) {
   switch (*s) {
      case 'u':
         return len < 6 ? JSON_STRING_INCOMPLETE
         : is_hex_digit(s[1]) && is_hex_digit(s[2]) &&
         is_hex_digit(s[3]) && is_hex_digit(s[4])
         ? 5
         : JSON_STRING_INVALID;
      case '"':
      case '\\':
      case '/':
      case 'b':
      case 'f':
      case 'n':
      case 'r':
      case 't':
         return len < 2 ? JSON_STRING_INCOMPLETE : 1;
      default:
         return JSON_STRING_INVALID;
   }
}

static int capture_ptr(struct frozen *f, const char *ptr, enum json_type type) {
   if (f->do_realloc && f->num_tokens >= f->max_tokens) {
      int new_size = f->max_tokens == 0 ? 100 : f->max_tokens * 2;
      void *p = FROZEN_REALLOC(f->tokens, new_size * sizeof(f->tokens[0]));
      if (p == NULL) return JSON_TOKEN_ARRAY_TOO_SMALL;
      f->max_tokens = new_size;
      f->tokens = (struct json_token *) p;
   }
   if (f->tokens == NULL || f->max_tokens == 0) return 0;
   if (f->num_tokens >= f->max_tokens) return JSON_TOKEN_ARRAY_TOO_SMALL;
   f->tokens[f->num_tokens].ptr = ptr;
   f->tokens[f->num_tokens].type = type;
   f->num_tokens++;
   return 0;
}

static int capture_len(struct frozen *f, int token_index, const char *ptr) {
   if (f->tokens == 0 || f->max_tokens == 0) return 0;
   EXPECT(token_index >= 0 && token_index < f->max_tokens, JSON_STRING_INVALID);
   f->tokens[token_index].len = ptr - f->tokens[token_index].ptr;
   f->tokens[token_index].num_desc = (f->num_tokens - 1) - token_index;
   return 0;
}

/* identifier = letter { letter | digit | '_' } */
static int parse_identifier(struct frozen *f) {
   EXPECT(is_alpha(cur(f)), JSON_STRING_INVALID);
   TRY(capture_ptr(f, f->cur, JSON_TYPE_STRING));
   while (f->cur < f->end &&
          (*f->cur == '_' || is_alpha(*f->cur) || is_digit(*f->cur))) {
      f->cur++;
   }
   capture_len(f, f->num_tokens - 1, f->cur);
   return 0;
}

static int get_utf8_char_len(unsigned char ch) {
   if ((ch & 0x80) == 0) return 1;
   switch (ch & 0xf0) {
      case 0xf0:
         return 4;
      case 0xe0:
         return 3;
      default:
         return 2;
   }
}

/* string = '"' { quoted_printable_chars } '"' */
static int parse_string(struct frozen *f) {
   int n, ch = 0, len = 0;
   TRY(test_and_skip(f, '"'));
   TRY(capture_ptr(f, f->cur, JSON_TYPE_STRING));
   for (; f->cur < f->end; f->cur += len) {
      ch = *(unsigned char *) f->cur;
      len = get_utf8_char_len((unsigned char) ch);
      EXPECT(ch >= 32 && len > 0, JSON_STRING_INVALID); /* No control chars */
      EXPECT(len < left(f), JSON_STRING_INCOMPLETE);
      if (ch == '\\') {
         EXPECT((n = get_escape_len(f->cur + 1, left(f))) > 0, n);
         len += n;
      } else if (ch == '"') {
         capture_len(f, f->num_tokens - 1, f->cur);
         f->cur++;
         break;
      };
   }
   return ch == '"' ? 0 : JSON_STRING_INCOMPLETE;
}

/* number = [ '-' ] digit+ [ '.' digit+ ] [ ['e'|'E'] ['+'|'-'] digit+ ] */
static int parse_number(struct frozen *f) {
   int ch = cur(f);
   TRY(capture_ptr(f, f->cur, JSON_TYPE_NUMBER));
   if (ch == '-') f->cur++;
   EXPECT(f->cur < f->end, JSON_STRING_INCOMPLETE);
   EXPECT(is_digit(f->cur[0]), JSON_STRING_INVALID);
   while (f->cur < f->end && is_digit(f->cur[0])) f->cur++;
   if (f->cur < f->end && f->cur[0] == '.') {
      f->cur++;
      EXPECT(f->cur < f->end, JSON_STRING_INCOMPLETE);
      EXPECT(is_digit(f->cur[0]), JSON_STRING_INVALID);
      while (f->cur < f->end && is_digit(f->cur[0])) f->cur++;
   }
   if (f->cur < f->end && (f->cur[0] == 'e' || f->cur[0] == 'E')) {
      f->cur++;
      EXPECT(f->cur < f->end, JSON_STRING_INCOMPLETE);
      if ((f->cur[0] == '+' || f->cur[0] == '-')) f->cur++;
      EXPECT(f->cur < f->end, JSON_STRING_INCOMPLETE);
      EXPECT(is_digit(f->cur[0]), JSON_STRING_INVALID);
      while (f->cur < f->end && is_digit(f->cur[0])) f->cur++;
   }
   capture_len(f, f->num_tokens - 1, f->cur);
   return 0;
}

/* array = '[' [ value { ',' value } ] ']' */
static int parse_array(struct frozen *f) {
   int ind;
   TRY(test_and_skip(f, '['));
   TRY(capture_ptr(f, f->cur - 1, JSON_TYPE_ARRAY));
   ind = f->num_tokens - 1;
   while (cur(f) != ']') {
      TRY(parse_value(f));
      if (cur(f) == ',') f->cur++;
   }
   TRY(test_and_skip(f, ']'));
   capture_len(f, ind, f->cur);
   return 0;
}

static int compare(const char *s, const char *str, int len) {
   int i = 0;
   while (i < len && s[i] == str[i]) i++;
   return i == len ? 1 : 0;
}

static int expect(struct frozen *f, const char *s, int len, enum json_type t) {
   int i, n = left(f);
   
   TRY(capture_ptr(f, f->cur, t));
   for (i = 0; i < len; i++) {
      if (i >= n) return JSON_STRING_INCOMPLETE;
      if (f->cur[i] != s[i]) return JSON_STRING_INVALID;
   }
   f->cur += len;
   TRY(capture_len(f, f->num_tokens - 1, f->cur));
   
   return 0;
}

/* value = 'null' | 'true' | 'false' | number | string | array | object */
static int parse_value(struct frozen *f) {
   int ch = cur(f);
   
   switch (ch) {
      case '"':
         TRY(parse_string(f));
         break;
      case '{':
         TRY(parse_object(f));
         break;
      case '[':
         TRY(parse_array(f));
         break;
      case 'n':
         TRY(expect(f, "null", 4, JSON_TYPE_NULL));
         break;
      case 't':
         TRY(expect(f, "true", 4, JSON_TYPE_TRUE));
         break;
      case 'f':
         TRY(expect(f, "false", 5, JSON_TYPE_FALSE));
         break;
      case '-':
      case '0':
      case '1':
      case '2':
      case '3':
      case '4':
      case '5':
      case '6':
      case '7':
      case '8':
      case '9':
         TRY(parse_number(f));
         break;
      default:
         return ch == END_OF_STRING ? JSON_STRING_INCOMPLETE : JSON_STRING_INVALID;
   }
   
   return 0;
}

/* key = identifier | string */
static int parse_key(struct frozen *f) {
   int ch = cur(f);
#if 0
   printf("%s 1 [%.*s]\n", __func__, (int) (f->end - f->cur), f->cur);
#endif
   if (is_alpha(ch)) {
      TRY(parse_identifier(f));
   } else if (ch == '"') {
      TRY(parse_string(f));
   } else {
      return ch == END_OF_STRING ? JSON_STRING_INCOMPLETE : JSON_STRING_INVALID;
   }
   return 0;
}

/* pair = key ':' value */
static int parse_pair(struct frozen *f) {
   TRY(parse_key(f));
   TRY(test_and_skip(f, ':'));
   TRY(parse_value(f));
   return 0;
}

/* object = '{' pair { ',' pair } '}' */
static int parse_object(struct frozen *f) {
   int ind;
   TRY(test_and_skip(f, '{'));
   TRY(capture_ptr(f, f->cur - 1, JSON_TYPE_OBJECT));
   ind = f->num_tokens - 1;
   while (cur(f) != '}') {
      TRY(parse_pair(f));
      if (cur(f) == ',') f->cur++;
   }
   TRY(test_and_skip(f, '}'));
   capture_len(f, ind, f->cur);
   return 0;
}

static int doit(struct frozen *f) {
   int ret = 0;
   
   if (f->cur == 0 || f->end < f->cur) return JSON_STRING_INVALID;
   if (f->end == f->cur) return JSON_STRING_INCOMPLETE;
   
   if (0 == (ret = test_no_skip(f, '{'))) {
      TRY(parse_object(f));
   } else if (0 == (ret = test_no_skip(f, '['))) {
      TRY(parse_array(f));
   } else {
      return ret;
   }
   
   TRY(capture_ptr(f, f->cur, JSON_TYPE_EOF));
   capture_len(f, f->num_tokens, f->cur);
   return 0;
}

/* json = object */
int parse_json(const char *s, int s_len, struct json_token *arr, int arr_len) {
   struct frozen frozen;
   
   memset(&frozen, 0, sizeof(frozen));
   frozen.end = s + s_len;
   frozen.cur = s;
   frozen.tokens = arr;
   frozen.max_tokens = arr_len;
   
   TRY(doit(&frozen));
   
   return frozen.cur - s;
}

struct json_token *parse_json2(const char *s, int s_len) {
   struct frozen frozen;
   
   memset(&frozen, 0, sizeof(frozen));
   frozen.end = s + s_len;
   frozen.cur = s;
   frozen.do_realloc = 1;
   
   if (doit(&frozen) < 0) {
      FROZEN_FREE((void *) frozen.tokens);
      frozen.tokens = NULL;
   }
   return frozen.tokens;
}

static int path_part_len(const char *p) {
   int i = 0;
   while (p[i] != '\0' && p[i] != '[' && p[i] != '.') i++;
   return i;
}

struct json_token *find_json_token(struct json_token *toks, const char *path) {
   while (path != 0 && path[0] != '\0') {
      int i, ind2 = 0, ind = -1, skip = 2, n = path_part_len(path);
      if (path[0] == '[') {
         if (toks->type != JSON_TYPE_ARRAY || !is_digit(path[1])) return 0;
         for (ind = 0, n = 1; path[n] != ']' && path[n] != '\0'; n++) {
            if (!is_digit(path[n])) return 0;
            ind *= 10;
            ind += path[n] - '0';
         }
         if (path[n++] != ']') return 0;
         skip = 1; /* In objects, we skip 2 elems while iterating, in arrays 1. */
      } else if (toks->type != JSON_TYPE_OBJECT)
         return 0;
      toks++;
      for (i = 0; i < toks[-1].num_desc; i += skip, ind2++) {
         /* ind == -1 indicated that we're iterating an array, not object */
         if (ind == -1 && toks[i].type != JSON_TYPE_STRING) return 0;
         if (ind2 == ind ||
             (ind == -1 && toks[i].len == n && compare(path, toks[i].ptr, n))) {
            i += skip - 1;
            break;
         };
         if (toks[i - 1 + skip].type == JSON_TYPE_ARRAY ||
             toks[i - 1 + skip].type == JSON_TYPE_OBJECT) {
            i += toks[i - 1 + skip].num_desc;
         }
      }
      if (i == toks[-1].num_desc) return 0;
      path += n;
      if (path[0] == '.') path++;
      if (path[0] == '\0') return &toks[i];
      toks += i;
   }
   return 0;
}

int json_emit_long(char *buf, int buf_len, long int value) {
   char tmp[20];
   int n = snprintf(tmp, sizeof(tmp), "%ld", value);
   strncpy(buf, tmp, buf_len > 0 ? buf_len : 0);
   return n;
}

int json_emit_double(char *buf, int buf_len, double value) {
   char tmp[20];
   int n = snprintf(tmp, sizeof(tmp), "%g", value);
   strncpy(buf, tmp, buf_len > 0 ? buf_len : 0);
   return n;
}

int json_emit_quoted_str(char *s, int s_len, const char *str, int len) {
   const char *begin = s, *end = s + s_len, *str_end = str + len;
   char ch;
   
#define EMIT(x)          \
do {                   \
if (s < end) *s = x; \
s++;                 \
} while (0)
   
   EMIT('"');
   while (str < str_end) {
      ch = *str++;
      switch (ch) {
         case '"':
            EMIT('\\');
            EMIT('"');
            break;
         case '\\':
            EMIT('\\');
            EMIT('\\');
            break;
         case '\b':
            EMIT('\\');
            EMIT('b');
            break;
         case '\f':
            EMIT('\\');
            EMIT('f');
            break;
         case '\n':
            EMIT('\\');
            EMIT('n');
            break;
         case '\r':
            EMIT('\\');
            EMIT('r');
            break;
         case '\t':
            EMIT('\\');
            EMIT('t');
            break;
         default:
            EMIT(ch);
      }
   }
   EMIT('"');
   if (s < end) {
      *s = '\0';
   }
   
   return s - begin;
}

int json_emit_unquoted_str(char *buf, int buf_len, const char *str, int len) {
   if (buf_len > 0 && len > 0) {
      int n = len < buf_len ? len : buf_len;
      memcpy(buf, str, n);
      if (n < buf_len) {
         buf[n] = '\0';
      }
   }
   return len;
}

int json_emit_va(char *s, int s_len, const char *fmt, va_list ap) {
   const char *end = s + s_len, *str, *orig = s;
   size_t len;
   
   while (*fmt != '\0') {
      switch (*fmt) {
         case '[':
         case ']':
         case '{':
         case '}':
         case ',':
         case ':':
         case ' ':
         case '\r':
         case '\n':
         case '\t':
            if (s < end) {
               *s = *fmt;
            }
            s++;
            break;
         case 'i':
            s += json_emit_long(s, end - s, va_arg(ap, long) );
            break;
         case 'f':
            s += json_emit_double(s, end - s, va_arg(ap, double) );
            break;
         case 'v':
            str = va_arg(ap, char *);
            len = va_arg(ap, size_t);
            s += json_emit_quoted_str(s, end - s, str, len);
            break;
         case 'V':
            str = va_arg(ap, char *);
            len = va_arg(ap, size_t);
            s += json_emit_unquoted_str(s, end - s, str, len);
            break;
         case 's':
            str = va_arg(ap, char *);
            s += json_emit_quoted_str(s, end - s, str, strlen(str));
            break;
         case 'S':
            str = va_arg(ap, char *);
            s += json_emit_unquoted_str(s, end - s, str, strlen(str));
            break;
         case 'T':
            s += json_emit_unquoted_str(s, end - s, "true", 4);
            break;
         case 'F':
            s += json_emit_unquoted_str(s, end - s, "false", 5);
            break;
         case 'N':
            s += json_emit_unquoted_str(s, end - s, "null", 4);
            break;
         default:
            return 0;
      }
      fmt++;
   }
   
   /* Best-effort to 0-terminate generated string */
   if (s < end) {
      *s = '\0';
   }
   
   return s - orig;
}

int json_emit(char *buf, int buf_len, const char *fmt, ...) {
   int len;
   va_list ap;
   
   va_start(ap, fmt);
   len = json_emit_va(buf, buf_len, fmt, ap);
   va_end(ap);
   
   return len;
}
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/md5.c"
#endif
/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */

#if !defined(DISABLE_MD5) && !defined(EXCLUDE_COMMON)

/* Amalgamated: #include "common/md5.h" */

#ifndef CS_ENABLE_NATIVE_MD5
static void byteReverse(unsigned char *buf, unsigned longs) {
   /* Forrest: MD5 expect LITTLE_ENDIAN, swap if BIG_ENDIAN */
#if BYTE_ORDER == BIG_ENDIAN
   do {
      uint32_t t = (uint32_t)((unsigned) buf[3] << 8 | buf[2]) << 16 |
      ((unsigned) buf[1] << 8 | buf[0]);
      *(uint32_t *) buf = t;
      buf += 4;
   } while (--longs);
#else
   (void) buf;
   (void) longs;
#endif
}

#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

#define MD5STEP(f, w, x, y, z, data, s) \
(w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void MD5_Init(MD5_CTX *ctx) {
   ctx->buf[0] = 0x67452301;
   ctx->buf[1] = 0xefcdab89;
   ctx->buf[2] = 0x98badcfe;
   ctx->buf[3] = 0x10325476;
   
   ctx->bits[0] = 0;
   ctx->bits[1] = 0;
}

static void MD5Transform(uint32_t buf[4], uint32_t const in[16]) {
   uint32_t a, b, c, d;
   
   a = buf[0];
   b = buf[1];
   c = buf[2];
   d = buf[3];
   
   MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
   MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
   MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
   MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
   MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
   MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
   MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
   MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
   MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
   MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
   MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
   MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
   MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
   MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
   MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
   MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
   
   MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
   MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
   MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
   MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
   MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
   MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
   MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
   MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
   MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
   MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
   MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
   MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
   MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
   MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
   MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
   MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
   
   MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
   MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
   MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
   MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
   MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
   MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
   MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
   MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
   MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
   MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
   MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
   MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
   MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
   MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
   MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
   MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
   
   MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
   MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
   MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
   MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
   MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
   MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
   MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
   MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
   MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
   MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
   MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
   MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
   MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
   MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
   MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
   MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
   
   buf[0] += a;
   buf[1] += b;
   buf[2] += c;
   buf[3] += d;
}

void MD5_Update(MD5_CTX *ctx, const unsigned char *buf, size_t len) {
   uint32_t t;
   
   t = ctx->bits[0];
   if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t) ctx->bits[1]++;
   ctx->bits[1] += (uint32_t) len >> 29;
   
   t = (t >> 3) & 0x3f;
   
   if (t) {
      unsigned char *p = (unsigned char *) ctx->in + t;
      
      t = 64 - t;
      if (len < t) {
         memcpy(p, buf, len);
         return;
      }
      memcpy(p, buf, t);
      byteReverse(ctx->in, 16);
      MD5Transform(ctx->buf, (uint32_t *) ctx->in);
      buf += t;
      len -= t;
   }
   
   while (len >= 64) {
      memcpy(ctx->in, buf, 64);
      byteReverse(ctx->in, 16);
      MD5Transform(ctx->buf, (uint32_t *) ctx->in);
      buf += 64;
      len -= 64;
   }
   
   memcpy(ctx->in, buf, len);
}

void MD5_Final(unsigned char digest[16], MD5_CTX *ctx) {
   unsigned count;
   unsigned char *p;
   uint32_t *a;
   
   count = (ctx->bits[0] >> 3) & 0x3F;
   
   p = ctx->in + count;
   *p++ = 0x80;
   count = 64 - 1 - count;
   if (count < 8) {
      memset(p, 0, count);
      byteReverse(ctx->in, 16);
      MD5Transform(ctx->buf, (uint32_t *) ctx->in);
      memset(ctx->in, 0, 56);
   } else {
      memset(p, 0, count - 8);
   }
   byteReverse(ctx->in, 14);
   
   a = (uint32_t *) ctx->in;
   a[14] = ctx->bits[0];
   a[15] = ctx->bits[1];
   
   MD5Transform(ctx->buf, (uint32_t *) ctx->in);
   byteReverse((unsigned char *) ctx->buf, 4);
   memcpy(digest, ctx->buf, 16);
   memset((char *) ctx, 0, sizeof(*ctx));
}
#endif /* CS_ENABLE_NATIVE_MD5 */

/*
 * Stringify binary data. Output buffer size must be 2 * size_of_input + 1
 * because each byte of input takes 2 bytes in string representation
 * plus 1 byte for the terminating \0 character.
 */
void cs_to_hex(char *to, const unsigned char *p, size_t len) {
   static const char *hex = "0123456789abcdef";
   
   for (; len--; p++) {
      *to++ = hex[p[0] >> 4];
      *to++ = hex[p[0] & 0x0f];
   }
   *to = '\0';
}

char *cs_md5(char buf[33], ...) {
   unsigned char hash[16];
   const unsigned char *p;
   va_list ap;
   MD5_CTX ctx;
   
   MD5_Init(&ctx);
   
   va_start(ap, buf);
   while ((p = va_arg(ap, const unsigned char *) ) != NULL) {
      size_t len = va_arg(ap, size_t);
      MD5_Update(&ctx, p, len);
   }
   va_end(ap);
   
   MD5_Final(hash, &ctx);
   cs_to_hex(buf, hash, sizeof(hash));
   
   return buf;
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/mbuf.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#ifndef EXCLUDE_COMMON

#include <assert.h>
#include <string.h>
/* Amalgamated: #include "common/mbuf.h" */

#ifndef MBUF_REALLOC
#define MBUF_REALLOC realloc
#endif

#ifndef MBUF_FREE
#define MBUF_FREE free
#endif

void mbuf_init(struct mbuf *mbuf, size_t initial_size) {
   mbuf->len = mbuf->size = 0;
   mbuf->buf = NULL;
   mbuf_resize(mbuf, initial_size);
}

void mbuf_free(struct mbuf *mbuf) {
   if (mbuf->buf != NULL) {
      MBUF_FREE(mbuf->buf);
      mbuf_init(mbuf, 0);
   }
}

void mbuf_resize(struct mbuf *a, size_t new_size) {
   if (new_size > a->size || (new_size < a->size && new_size >= a->len)) {
      char *buf = (char *) MBUF_REALLOC(a->buf, new_size);
      /*
       * In case realloc fails, there's not much we can do, except keep things as
       * they are. Note that NULL is a valid return value from realloc when
       * size == 0, but that is covered too.
       */
      if (buf == NULL && new_size != 0) return;
      a->buf = buf;
      a->size = new_size;
   }
}

void mbuf_trim(struct mbuf *mbuf) {
   mbuf_resize(mbuf, mbuf->len);
}

size_t mbuf_insert(struct mbuf *a, size_t off, const void *buf, size_t len) {
   char *p = NULL;
   
   assert(a != NULL);
   assert(a->len <= a->size);
   assert(off <= a->len);
   
   /* check overflow */
   if (~(size_t) 0 - (size_t) a->buf < len) return 0;
   
   if (a->len + len <= a->size) {
      memmove(a->buf + off + len, a->buf + off, a->len - off);
      if (buf != NULL) {
         memcpy(a->buf + off, buf, len);
      }
      a->len += len;
   } else {
      size_t new_size = (a->len + len) * MBUF_SIZE_MULTIPLIER;
      if ((p = (char *) MBUF_REALLOC(a->buf, new_size)) != NULL) {
         a->buf = p;
         memmove(a->buf + off + len, a->buf + off, a->len - off);
         if (buf != NULL) memcpy(a->buf + off, buf, len);
         a->len += len;
         a->size = new_size;
      } else {
         len = 0;
      }
   }
   
   return len;
}

size_t mbuf_append(struct mbuf *a, const void *buf, size_t len) {
   return mbuf_insert(a, a->len, buf, len);
}

void mbuf_remove(struct mbuf *mb, size_t n) {
   if (n > 0 && n <= mb->len) {
      memmove(mb->buf, mb->buf + n, mb->len - n);
      mb->len -= n;
   }
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/sha1.c"
#endif
/* Copyright(c) By Steve Reid <steve@edmweb.com> */
/* 100% Public Domain */

#if !defined(DISABLE_SHA1) && !defined(EXCLUDE_COMMON)

/* Amalgamated: #include "common/sha1.h" */

#define SHA1HANDSOFF
#if defined(__sun)
/* Amalgamated: #include "common/solarisfixes.h" */
#endif

union char64long16 {
   unsigned char c[64];
   uint32_t l[16];
};

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

static uint32_t blk0(union char64long16 *block, int i) {
   /* Forrest: SHA expect BIG_ENDIAN, swap if LITTLE_ENDIAN */
#if BYTE_ORDER == LITTLE_ENDIAN
   block->l[i] =
   (rol(block->l[i], 24) & 0xFF00FF00) | (rol(block->l[i], 8) & 0x00FF00FF);
#endif
   return block->l[i];
}

/* Avoid redefine warning (ARM /usr/include/sys/ucontext.h define R0~R4) */
#undef blk
#undef R0
#undef R1
#undef R2
#undef R3
#undef R4

#define blk(i)                                                               \
(block->l[i & 15] = rol(block->l[(i + 13) & 15] ^ block->l[(i + 8) & 15] ^ \
block->l[(i + 2) & 15] ^ block->l[i & 15],     \
1))
#define R0(v, w, x, y, z, i)                                          \
z += ((w & (x ^ y)) ^ y) + blk0(block, i) + 0x5A827999 + rol(v, 5); \
w = rol(w, 30);
#define R1(v, w, x, y, z, i)                                  \
z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
w = rol(w, 30);
#define R2(v, w, x, y, z, i)                          \
z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); \
w = rol(w, 30);
#define R3(v, w, x, y, z, i)                                        \
z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
w = rol(w, 30);
#define R4(v, w, x, y, z, i)                          \
z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
w = rol(w, 30);

void cs_sha1_transform(uint32_t state[5], const unsigned char buffer[64]) {
   uint32_t a, b, c, d, e;
   union char64long16 block[1];
   
   memcpy(block, buffer, 64);
   a = state[0];
   b = state[1];
   c = state[2];
   d = state[3];
   e = state[4];
   R0(a, b, c, d, e, 0);
   R0(e, a, b, c, d, 1);
   R0(d, e, a, b, c, 2);
   R0(c, d, e, a, b, 3);
   R0(b, c, d, e, a, 4);
   R0(a, b, c, d, e, 5);
   R0(e, a, b, c, d, 6);
   R0(d, e, a, b, c, 7);
   R0(c, d, e, a, b, 8);
   R0(b, c, d, e, a, 9);
   R0(a, b, c, d, e, 10);
   R0(e, a, b, c, d, 11);
   R0(d, e, a, b, c, 12);
   R0(c, d, e, a, b, 13);
   R0(b, c, d, e, a, 14);
   R0(a, b, c, d, e, 15);
   R1(e, a, b, c, d, 16);
   R1(d, e, a, b, c, 17);
   R1(c, d, e, a, b, 18);
   R1(b, c, d, e, a, 19);
   R2(a, b, c, d, e, 20);
   R2(e, a, b, c, d, 21);
   R2(d, e, a, b, c, 22);
   R2(c, d, e, a, b, 23);
   R2(b, c, d, e, a, 24);
   R2(a, b, c, d, e, 25);
   R2(e, a, b, c, d, 26);
   R2(d, e, a, b, c, 27);
   R2(c, d, e, a, b, 28);
   R2(b, c, d, e, a, 29);
   R2(a, b, c, d, e, 30);
   R2(e, a, b, c, d, 31);
   R2(d, e, a, b, c, 32);
   R2(c, d, e, a, b, 33);
   R2(b, c, d, e, a, 34);
   R2(a, b, c, d, e, 35);
   R2(e, a, b, c, d, 36);
   R2(d, e, a, b, c, 37);
   R2(c, d, e, a, b, 38);
   R2(b, c, d, e, a, 39);
   R3(a, b, c, d, e, 40);
   R3(e, a, b, c, d, 41);
   R3(d, e, a, b, c, 42);
   R3(c, d, e, a, b, 43);
   R3(b, c, d, e, a, 44);
   R3(a, b, c, d, e, 45);
   R3(e, a, b, c, d, 46);
   R3(d, e, a, b, c, 47);
   R3(c, d, e, a, b, 48);
   R3(b, c, d, e, a, 49);
   R3(a, b, c, d, e, 50);
   R3(e, a, b, c, d, 51);
   R3(d, e, a, b, c, 52);
   R3(c, d, e, a, b, 53);
   R3(b, c, d, e, a, 54);
   R3(a, b, c, d, e, 55);
   R3(e, a, b, c, d, 56);
   R3(d, e, a, b, c, 57);
   R3(c, d, e, a, b, 58);
   R3(b, c, d, e, a, 59);
   R4(a, b, c, d, e, 60);
   R4(e, a, b, c, d, 61);
   R4(d, e, a, b, c, 62);
   R4(c, d, e, a, b, 63);
   R4(b, c, d, e, a, 64);
   R4(a, b, c, d, e, 65);
   R4(e, a, b, c, d, 66);
   R4(d, e, a, b, c, 67);
   R4(c, d, e, a, b, 68);
   R4(b, c, d, e, a, 69);
   R4(a, b, c, d, e, 70);
   R4(e, a, b, c, d, 71);
   R4(d, e, a, b, c, 72);
   R4(c, d, e, a, b, 73);
   R4(b, c, d, e, a, 74);
   R4(a, b, c, d, e, 75);
   R4(e, a, b, c, d, 76);
   R4(d, e, a, b, c, 77);
   R4(c, d, e, a, b, 78);
   R4(b, c, d, e, a, 79);
   state[0] += a;
   state[1] += b;
   state[2] += c;
   state[3] += d;
   state[4] += e;
   /* Erase working structures. The order of operations is important,
    * used to ensure that compiler doesn't optimize those out. */
   memset(block, 0, sizeof(block));
   a = b = c = d = e = 0;
   (void) a;
   (void) b;
   (void) c;
   (void) d;
   (void) e;
}

void cs_sha1_init(cs_sha1_ctx *context) {
   context->state[0] = 0x67452301;
   context->state[1] = 0xEFCDAB89;
   context->state[2] = 0x98BADCFE;
   context->state[3] = 0x10325476;
   context->state[4] = 0xC3D2E1F0;
   context->count[0] = context->count[1] = 0;
}

void cs_sha1_update(cs_sha1_ctx *context, const unsigned char *data,
                    uint32_t len) {
   uint32_t i, j;
   
   j = context->count[0];
   if ((context->count[0] += len << 3) < j) context->count[1]++;
   context->count[1] += (len >> 29);
   j = (j >> 3) & 63;
   if ((j + len) > 63) {
      memcpy(&context->buffer[j], data, (i = 64 - j));
      cs_sha1_transform(context->state, context->buffer);
      for (; i + 63 < len; i += 64) {
         cs_sha1_transform(context->state, &data[i]);
      }
      j = 0;
   } else
      i = 0;
   memcpy(&context->buffer[j], &data[i], len - i);
}

void cs_sha1_final(unsigned char digest[20], cs_sha1_ctx *context) {
   unsigned i;
   unsigned char finalcount[8], c;
   
   for (i = 0; i < 8; i++) {
      finalcount[i] = (unsigned char) ((context->count[(i >= 4 ? 0 : 1)] >>
                                        ((3 - (i & 3)) * 8)) &
                                       255);
   }
   c = 0200;
   cs_sha1_update(context, &c, 1);
   while ((context->count[0] & 504) != 448) {
      c = 0000;
      cs_sha1_update(context, &c, 1);
   }
   cs_sha1_update(context, finalcount, 8);
   for (i = 0; i < 20; i++) {
      digest[i] =
      (unsigned char) ((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255);
   }
   memset(context, '\0', sizeof(*context));
   memset(&finalcount, '\0', sizeof(finalcount));
}

void cs_hmac_sha1(const unsigned char *key, size_t keylen,
                  const unsigned char *data, size_t datalen,
                  unsigned char out[20]) {
   cs_sha1_ctx ctx;
   unsigned char buf1[64], buf2[64], tmp_key[20], i;
   
   if (keylen > sizeof(buf1)) {
      cs_sha1_init(&ctx);
      cs_sha1_update(&ctx, key, keylen);
      cs_sha1_final(tmp_key, &ctx);
      key = tmp_key;
      keylen = sizeof(tmp_key);
   }
   
   memset(buf1, 0, sizeof(buf1));
   memset(buf2, 0, sizeof(buf2));
   memcpy(buf1, key, keylen);
   memcpy(buf2, key, keylen);
   
   for (i = 0; i < sizeof(buf1); i++) {
      buf1[i] ^= 0x36;
      buf2[i] ^= 0x5c;
   }
   
   cs_sha1_init(&ctx);
   cs_sha1_update(&ctx, buf1, sizeof(buf1));
   cs_sha1_update(&ctx, data, datalen);
   cs_sha1_final(out, &ctx);
   
   cs_sha1_init(&ctx);
   cs_sha1_update(&ctx, buf2, sizeof(buf2));
   cs_sha1_update(&ctx, out, 20);
   cs_sha1_final(out, &ctx);
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/str_util.c"
#endif
/*
 * Copyright (c) 2015 Cesanta Software Limited
 * All rights reserved
 */

#ifndef EXCLUDE_COMMON

/* Amalgamated: #include "common/platform.h" */
/* Amalgamated: #include "common/str_util.h" */

size_t c_strnlen(const char *s, size_t maxlen) {
   size_t l = 0;
   for (; l < maxlen && s[l] != '\0'; l++) {
   }
   return l;
}

#define C_SNPRINTF_APPEND_CHAR(ch)       \
do {                                   \
if (i < (int) buf_size) buf[i] = ch; \
i++;                                 \
} while (0)

#define C_SNPRINTF_FLAG_ZERO 1

#ifdef C_DISABLE_BUILTIN_SNPRINTF
int c_vsnprintf(char *buf, size_t buf_size, const char *fmt, va_list ap) {
   return vsnprintf(buf, buf_size, fmt, ap);
}
#else
static int c_itoa(char *buf, size_t buf_size, int64_t num, int base, int flags,
                  int field_width) {
   char tmp[40];
   int i = 0, k = 0, neg = 0;
   
   if (num < 0) {
      neg++;
      num = -num;
   }
   
   /* Print into temporary buffer - in reverse order */
   do {
      int rem = num % base;
      if (rem < 10) {
         tmp[k++] = '0' + rem;
      } else {
         tmp[k++] = 'a' + (rem - 10);
      }
      num /= base;
   } while (num > 0);
   
   /* Zero padding */
   if (flags && C_SNPRINTF_FLAG_ZERO) {
      while (k < field_width && k < (int) sizeof(tmp) - 1) {
         tmp[k++] = '0';
      }
   }
   
   /* And sign */
   if (neg) {
      tmp[k++] = '-';
   }
   
   /* Now output */
   while (--k >= 0) {
      C_SNPRINTF_APPEND_CHAR(tmp[k]);
   }
   
   return i;
}

int c_vsnprintf(char *buf, size_t buf_size, const char *fmt, va_list ap) {
   int ch, i = 0, len_mod, flags, precision, field_width;
   
   while ((ch = *fmt++) != '\0') {
      if (ch != '%') {
         C_SNPRINTF_APPEND_CHAR(ch);
      } else {
         /*
          * Conversion specification:
          *   zero or more flags (one of: # 0 - <space> + ')
          *   an optional minimum  field  width (digits)
          *   an  optional precision (. followed by digits, or *)
          *   an optional length modifier (one of: hh h l ll L q j z t)
          *   conversion specifier (one of: d i o u x X e E f F g G a A c s p n)
          */
         flags = field_width = precision = len_mod = 0;
         
         /* Flags. only zero-pad flag is supported. */
         if (*fmt == '0') {
            flags |= C_SNPRINTF_FLAG_ZERO;
         }
         
         /* Field width */
         while (*fmt >= '0' && *fmt <= '9') {
            field_width *= 10;
            field_width += *fmt++ - '0';
         }
         /* Dynamic field width */
         if (*fmt == '*') {
            field_width = va_arg(ap, int);
            fmt++;
         }
         
         /* Precision */
         if (*fmt == '.') {
            fmt++;
            if (*fmt == '*') {
               precision = va_arg(ap, int);
               fmt++;
            } else {
               while (*fmt >= '0' && *fmt <= '9') {
                  precision *= 10;
                  precision += *fmt++ - '0';
               }
            }
         }
         
         /* Length modifier */
         switch (*fmt) {
            case 'h':
            case 'l':
            case 'L':
            case 'I':
            case 'q':
            case 'j':
            case 'z':
            case 't':
               len_mod = *fmt++;
               if (*fmt == 'h') {
                  len_mod = 'H';
                  fmt++;
               }
               if (*fmt == 'l') {
                  len_mod = 'q';
                  fmt++;
               }
               break;
         }
         
         ch = *fmt++;
         if (ch == 's') {
            const char *s = va_arg(ap, const char *); /* Always fetch parameter */
            int j;
            int pad = field_width - (precision >= 0 ? c_strnlen(s, precision) : 0);
            for (j = 0; j < pad; j++) {
               C_SNPRINTF_APPEND_CHAR(' ');
            }
            
            /* `s` may be NULL in case of %.*s */
            if (s != NULL) {
               /* Ignore negative and 0 precisions */
               for (j = 0; (precision <= 0 || j < precision) && s[j] != '\0'; j++) {
                  C_SNPRINTF_APPEND_CHAR(s[j]);
               }
            }
         } else if (ch == 'c') {
            ch = va_arg(ap, int); /* Always fetch parameter */
            C_SNPRINTF_APPEND_CHAR(ch);
         } else if (ch == 'd' && len_mod == 0) {
            i += c_itoa(buf + i, buf_size - i, va_arg(ap, int), 10, flags,
                        field_width);
         } else if (ch == 'd' && len_mod == 'l') {
            i += c_itoa(buf + i, buf_size - i, va_arg(ap, long), 10, flags,
                        field_width);
#ifdef SSIZE_MAX
         } else if (ch == 'd' && len_mod == 'z') {
            i += c_itoa(buf + i, buf_size - i, va_arg(ap, ssize_t), 10, flags,
                        field_width);
#endif
         } else if (ch == 'd' && len_mod == 'q') {
            i += c_itoa(buf + i, buf_size - i, va_arg(ap, int64_t), 10, flags,
                        field_width);
         } else if ((ch == 'x' || ch == 'u') && len_mod == 0) {
            i += c_itoa(buf + i, buf_size - i, va_arg(ap, unsigned),
                        ch == 'x' ? 16 : 10, flags, field_width);
         } else if ((ch == 'x' || ch == 'u') && len_mod == 'l') {
            i += c_itoa(buf + i, buf_size - i, va_arg(ap, unsigned long),
                        ch == 'x' ? 16 : 10, flags, field_width);
         } else if ((ch == 'x' || ch == 'u') && len_mod == 'z') {
            i += c_itoa(buf + i, buf_size - i, va_arg(ap, size_t),
                        ch == 'x' ? 16 : 10, flags, field_width);
         } else if (ch == 'p') {
            unsigned long num = (unsigned long) va_arg(ap, void *);
            C_SNPRINTF_APPEND_CHAR('0');
            C_SNPRINTF_APPEND_CHAR('x');
            i += c_itoa(buf + i, buf_size - i, num, 16, flags, 0);
         } else {
#ifndef NO_LIBC
            /*
             * TODO(lsm): abort is not nice in a library, remove it
             * Also, ESP8266 SDK doesn't have it
             */
            abort();
#endif
         }
      }
   }
   
   /* Zero-terminate the result */
   if (buf_size > 0) {
      buf[i < (int) buf_size ? i : (int) buf_size - 1] = '\0';
   }
   
   return i;
}
#endif

int c_snprintf(char *buf, size_t buf_size, const char *fmt, ...) {
   int result;
   va_list ap;
   va_start(ap, fmt);
   result = c_vsnprintf(buf, buf_size, fmt, ap);
   va_end(ap);
   return result;
}

#ifdef _WIN32
int to_wchar(const char *path, wchar_t *wbuf, size_t wbuf_len) {
   int ret;
   char buf[MAX_PATH * 2], buf2[MAX_PATH * 2], *p;
   
   strncpy(buf, path, sizeof(buf));
   buf[sizeof(buf) - 1] = '\0';
   
   /* Trim trailing slashes. Leave backslash for paths like "X:\" */
   p = buf + strlen(buf) - 1;
   while (p > buf && p[-1] != ':' && (p[0] == '\\' || p[0] == '/')) *p-- = '\0';
   
   memset(wbuf, 0, wbuf_len * sizeof(wchar_t));
   ret = MultiByteToWideChar(CP_UTF8, 0, buf, -1, wbuf, (int) wbuf_len);
   
   /*
    * Convert back to Unicode. If doubly-converted string does not match the
    * original, something is fishy, reject.
    */
   WideCharToMultiByte(CP_UTF8, 0, wbuf, (int) wbuf_len, buf2, sizeof(buf2),
                       NULL, NULL);
   if (strcmp(buf, buf2) != 0) {
      wbuf[0] = L'\0';
      ret = 0;
   }
   
   return ret;
}
#endif /* _WIN32 */

/* The simplest O(mn) algorithm. Better implementation are GPLed */
const char *c_strnstr(const char *s, const char *find, size_t slen) {
   size_t find_length = strlen(find);
   size_t i;
   
   for (i = 0; i < slen; i++) {
      if (i + find_length > slen) {
         return NULL;
      }
      
      if (strncmp(&s[i], find, find_length) == 0) {
         return &s[i];
      }
   }
   
   return NULL;
}

#endif /* EXCLUDE_COMMON */
#ifdef MG_MODULE_LINES
#line 1 "./src/net.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 *
 * This software is dual-licensed: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. For the terms of this
 * license, see <http://www.gnu.org/licenses/>.
 *
 * You are free to use this software under the terms of the GNU General
 * Public License, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * Alternatively, you can license this software under a commercial
 * license, as set out in <https://www.cesanta.com/license>.
 */

/* Amalgamated: #include "mongoose/src/internal.h" */
/* Amalgamated: #include "mongoose/src/util.h" */
/* Amalgamated: #include "mongoose/src/dns.h" */
/* Amalgamated: #include "mongoose/src/resolv.h" */
/* Amalgamated: #include "common/cs_time.h" */

#define MG_MAX_HOST_LEN 200

#define MG_COPY_COMMON_CONNECTION_OPTIONS(dst, src) \
memcpy(dst, src, sizeof(*dst));

/* Which flags can be pre-set by the user at connection creation time. */
#define _MG_ALLOWED_CONNECT_FLAGS_MASK                                   \
(MG_F_USER_1 | MG_F_USER_2 | MG_F_USER_3 | MG_F_USER_4 | MG_F_USER_5 | \
MG_F_USER_6 | MG_F_WEBSOCKET_NO_DEFRAG)
/* Which flags should be modifiable by user's callbacks. */
#define _MG_CALLBACK_MODIFIABLE_FLAGS_MASK                               \
(MG_F_USER_1 | MG_F_USER_2 | MG_F_USER_3 | MG_F_USER_4 | MG_F_USER_5 | \
MG_F_USER_6 | MG_F_WEBSOCKET_NO_DEFRAG | MG_F_SEND_AND_CLOSE |        \
MG_F_CLOSE_IMMEDIATELY | MG_F_IS_WEBSOCKET | MG_F_DELETE_CHUNK)

#ifndef intptr_t
#define intptr_t long
#endif

int mg_is_error(int n);
void mg_set_non_blocking_mode(sock_t sock);

extern void mg_ev_mgr_init(struct mg_mgr *mgr);
extern void mg_ev_mgr_free(struct mg_mgr *mgr);
extern void mg_ev_mgr_add_conn(struct mg_connection *nc);
extern void mg_ev_mgr_remove_conn(struct mg_connection *nc);

MG_INTERNAL void mg_add_conn(struct mg_mgr *mgr, struct mg_connection *c) {
   DBG(("%p %p", mgr, c));
   c->mgr = mgr;
   c->next = mgr->active_connections;
   mgr->active_connections = c;
   c->prev = NULL;
   if (c->next != NULL) c->next->prev = c;
   mg_ev_mgr_add_conn(c);
}

MG_INTERNAL void mg_remove_conn(struct mg_connection *conn) {
   if (conn->prev == NULL) conn->mgr->active_connections = conn->next;
   if (conn->prev) conn->prev->next = conn->next;
   if (conn->next) conn->next->prev = conn->prev;
   mg_ev_mgr_remove_conn(conn);
}

MG_INTERNAL void mg_call(struct mg_connection *nc,
                         mg_event_handler_t ev_handler, int ev, void *ev_data) {
   if (ev_handler == NULL) {
      /*
       * If protocol handler is specified, call it. Otherwise, call user-specified
       * event handler.
       */
      ev_handler = nc->proto_handler ? nc->proto_handler : nc->handler;
   }
   DBG(("%p %s ev=%d ev_data=%p flags=%lu rmbl=%d smbl=%d", nc,
        ev_handler == nc->handler ? "user" : "proto", ev, ev_data, nc->flags,
        (int) nc->recv_mbuf.len, (int) nc->send_mbuf.len));
   
#if !defined(NO_LIBC) && !defined(MG_DISABLE_HEXDUMP)
   /* LCOV_EXCL_START */
   if (nc->mgr->hexdump_file != NULL && ev != MG_EV_POLL &&
       ev != MG_EV_SEND /* handled separately */) {
      if (ev == MG_EV_RECV) {
         mg_hexdump_connection(nc, nc->mgr->hexdump_file, nc->recv_mbuf.buf,
                               *(int *) ev_data, ev);
      } else {
         mg_hexdump_connection(nc, nc->mgr->hexdump_file, NULL, 0, ev);
      }
   }
   /* LCOV_EXCL_STOP */
#endif
   if (ev_handler != NULL) {
      unsigned long flags_before = nc->flags;
      size_t recv_mbuf_before = nc->recv_mbuf.len, recved;
      ev_handler(nc, ev, ev_data);
      recved = (recv_mbuf_before - nc->recv_mbuf.len);
      /* Prevent user handler from fiddling with system flags. */
      if (ev_handler == nc->handler && nc->flags != flags_before) {
         nc->flags = (flags_before & ~_MG_CALLBACK_MODIFIABLE_FLAGS_MASK) |
         (nc->flags & _MG_CALLBACK_MODIFIABLE_FLAGS_MASK);
      }
      if (recved > 0 && !(nc->flags & MG_F_UDP)) {
         mg_if_recved(nc, recved);
      }
   }
   DBG(("%p after %s flags=%lu rmbl=%d smbl=%d", nc,
        ev_handler == nc->handler ? "user" : "proto", nc->flags,
        (int) nc->recv_mbuf.len, (int) nc->send_mbuf.len));
}

void mg_if_timer(struct mg_connection *c, double now) {
   if (c->ev_timer_time > 0 && now >= c->ev_timer_time) {
      double old_value = c->ev_timer_time;
      mg_call(c, NULL, MG_EV_TIMER, &now);
      /*
       * To prevent timer firing all the time, reset the timer after delivery.
       * However, in case user sets it to new value, do not reset.
       */
      if (c->ev_timer_time == old_value) {
         c->ev_timer_time = 0;
      }
   }
}

void mg_if_poll(struct mg_connection *nc, time_t now) {
   if (nc->ssl == NULL || (nc->flags & MG_F_SSL_HANDSHAKE_DONE)) {
      mg_call(nc, NULL, MG_EV_POLL, &now);
   }
}

static void mg_destroy_conn(struct mg_connection *conn) {
   if (conn->proto_data != NULL && conn->proto_data_destructor != NULL) {
      conn->proto_data_destructor(conn->proto_data);
   }
   mg_if_destroy_conn(conn);
#ifdef MG_ENABLE_SSL
   if (conn->ssl != NULL) SSL_free(conn->ssl);
   if (conn->ssl_ctx != NULL) SSL_CTX_free(conn->ssl_ctx);
#endif
   mbuf_free(&conn->recv_mbuf);
   mbuf_free(&conn->send_mbuf);
   
   memset(conn, 0, sizeof(*conn));
   MG_FREE(conn);
}

void mg_close_conn(struct mg_connection *conn) {
   DBG(("%p %lu", conn, conn->flags));
   mg_call(conn, NULL, MG_EV_CLOSE, NULL);
   mg_remove_conn(conn);
   mg_destroy_conn(conn);
}

void mg_mgr_init(struct mg_mgr *m, void *user_data) {
   memset(m, 0, sizeof(*m));
#ifndef MG_DISABLE_SOCKETPAIR
   m->ctl[0] = m->ctl[1] = INVALID_SOCKET;
#endif
   m->user_data = user_data;
   
#ifdef _WIN32
   {
   WSADATA data;
   WSAStartup(MAKEWORD(2, 2), &data);
   }
#elif defined(__unix__)
   /* Ignore SIGPIPE signal, so if client cancels the request, it
    * won't kill the whole process. */
   signal(SIGPIPE, SIG_IGN);
#endif
   
#ifdef MG_ENABLE_SSL
   {
   static int init_done;
   if (!init_done) {
      SSL_library_init();
      init_done++;
   }
   }
#endif
   
   mg_ev_mgr_init(m);
   DBG(("=================================="));
   DBG(("init mgr=%p", m));
}

#ifdef MG_ENABLE_JAVASCRIPT
static enum v7_err mg_send_js(struct v7 *v7, v7_val_t *res) {
   v7_val_t arg0 = v7_arg(v7, 0);
   v7_val_t arg1 = v7_arg(v7, 1);
   struct mg_connection *c = (struct mg_connection *) v7_get_ptr(arg0);
   size_t len = 0;
   
   if (v7_is_string(arg1)) {
      const char *data = v7_get_string(v7, &arg1, &len);
      mg_send(c, data, len);
   }
   
   *res = v7_mk_number(len);
   
   return V7_OK;
}

enum v7_err mg_enable_javascript(struct mg_mgr *m, struct v7 *v7,
                                 const char *init_file_name) {
   v7_val_t v;
   m->v7 = v7;
   v7_set_method(v7, v7_get_global(v7), "mg_send", mg_send_js);
   return v7_exec_file(v7, init_file_name, &v);
}
#endif

void mg_mgr_free(struct mg_mgr *m) {
   struct mg_connection *conn, *tmp_conn;
   
   DBG(("%p", m));
   if (m == NULL) return;
   /* Do one last poll, see https://github.com/cesanta/mongoose/issues/286 */
   mg_mgr_poll(m, 0);
   
#ifndef MG_DISABLE_SOCKETPAIR
   if (m->ctl[0] != INVALID_SOCKET) closesocket(m->ctl[0]);
   if (m->ctl[1] != INVALID_SOCKET) closesocket(m->ctl[1]);
   m->ctl[0] = m->ctl[1] = INVALID_SOCKET;
#endif
   
   for (conn = m->active_connections; conn != NULL; conn = tmp_conn) {
      tmp_conn = conn->next;
      mg_close_conn(conn);
   }
   
   mg_ev_mgr_free(m);
}

int mg_vprintf(struct mg_connection *nc, const char *fmt, va_list ap) {
   char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
   int len;
   
   if ((len = mg_avprintf(&buf, sizeof(mem), fmt, ap)) > 0) {
      mg_send(nc, buf, len);
   }
   if (buf != mem && buf != NULL) {
      MG_FREE(buf); /* LCOV_EXCL_LINE */
   }               /* LCOV_EXCL_LINE */
   
   return len;
}

int mg_printf(struct mg_connection *conn, const char *fmt, ...) {
   int len;
   va_list ap;
   va_start(ap, fmt);
   len = mg_vprintf(conn, fmt, ap);
   va_end(ap);
   return len;
}

#ifndef MG_DISABLE_SYNC_RESOLVER
/* TODO(lsm): use non-blocking resolver */
static int mg_resolve2(const char *host, struct in_addr *ina) {
#ifdef MG_ENABLE_GETADDRINFO
   int rv = 0;
   struct addrinfo hints, *servinfo, *p;
   struct sockaddr_in *h = NULL;
   memset(&hints, 0, sizeof hints);
   hints.ai_family = AF_INET;
   hints.ai_socktype = SOCK_STREAM;
   if ((rv = getaddrinfo(host, NULL, NULL, &servinfo)) != 0) {
      DBG(("getaddrinfo(%s) failed: %s", host, strerror(errno)));
      return 0;
   }
   for (p = servinfo; p != NULL; p = p->ai_next) {
      memcpy(&h, &p->ai_addr, sizeof(struct sockaddr_in *));
      memcpy(ina, &h->sin_addr, sizeof(ina));
   }
   freeaddrinfo(servinfo);
   return 1;
#else
   struct hostent *he;
   if ((he = gethostbyname(host)) == NULL) {
      DBG(("gethostbyname(%s) failed: %s", host, strerror(errno)));
   } else {
      memcpy(ina, he->h_addr_list[0], sizeof(*ina));
      return 1;
   }
   return 0;
#endif /* MG_ENABLE_GETADDRINFO */
}

int mg_resolve(const char *host, char *buf, size_t n) {
   struct in_addr ad;
   return mg_resolve2(host, &ad) ? snprintf(buf, n, "%s", inet_ntoa(ad)) : 0;
}
#endif /* MG_DISABLE_SYNC_RESOLVER */

MG_INTERNAL struct mg_connection *mg_create_connection_base(
                                                            struct mg_mgr *mgr, mg_event_handler_t callback,
                                                            struct mg_add_sock_opts opts) {
   struct mg_connection *conn;
   
   if ((conn = (struct mg_connection *) MG_CALLOC(1, sizeof(*conn))) != NULL) {
      conn->sock = INVALID_SOCKET;
      conn->handler = callback;
      conn->mgr = mgr;
      conn->last_io_time = mg_time();
      conn->flags = opts.flags & _MG_ALLOWED_CONNECT_FLAGS_MASK;
      conn->user_data = opts.user_data;
      /*
       * SIZE_MAX is defined as a long long constant in
       * system headers on some platforms and so it
       * doesn't compile with pedantic ansi flags.
       */
      conn->recv_mbuf_limit = ~0;
   } else {
      MG_SET_PTRPTR(opts.error_string, "failed to create connection");
   }
   
   return conn;
}

MG_INTERNAL struct mg_connection *mg_create_connection(
                                                       struct mg_mgr *mgr, mg_event_handler_t callback,
                                                       struct mg_add_sock_opts opts) {
   struct mg_connection *conn = mg_create_connection_base(mgr, callback, opts);
   
   if (!mg_if_create_conn(conn)) {
      MG_FREE(conn);
      conn = NULL;
      MG_SET_PTRPTR(opts.error_string, "failed to init connection");
   }
   
   return conn;
}

/*
 * Address format: [PROTO://][HOST]:PORT
 *
 * HOST could be IPv4/IPv6 address or a host name.
 * `host` is a destination buffer to hold parsed HOST part. Shoud be at least
 * MG_MAX_HOST_LEN bytes long.
 * `proto` is a returned socket type, either SOCK_STREAM or SOCK_DGRAM
 *
 * Return:
 *   -1   on parse error
 *    0   if HOST needs DNS lookup
 *   >0   length of the address string
 */
MG_INTERNAL int mg_parse_address(const char *str, union socket_address *sa,
                                 int *proto, char *host, size_t host_len) {
   unsigned int a, b, c, d, port = 0;
   int ch, len = 0;
#ifdef MG_ENABLE_IPV6
   char buf[100];
#endif
   
   /*
    * MacOS needs that. If we do not zero it, subsequent bind() will fail.
    * Also, all-zeroes in the socket address means binding to all addresses
    * for both IPv4 and IPv6 (INADDR_ANY and IN6ADDR_ANY_INIT).
    */
   memset(sa, 0, sizeof(*sa));
   sa->sin.sin_family = AF_INET;
   
   *proto = SOCK_STREAM;
   
   if (strncmp(str, "udp://", 6) == 0) {
      str += 6;
      *proto = SOCK_DGRAM;
   } else if (strncmp(str, "tcp://", 6) == 0) {
      str += 6;
   }
   
   if (sscanf(str, "%u.%u.%u.%u:%u%n", &a, &b, &c, &d, &port, &len) == 5) {
      /* Bind to a specific IPv4 address, e.g. 192.168.1.5:8080 */
      sa->sin.sin_addr.s_addr =
      htonl(((uint32_t) a << 24) | ((uint32_t) b << 16) | c << 8 | d);
      sa->sin.sin_port = htons((uint16_t) port);
#ifdef MG_ENABLE_IPV6
   } else if (sscanf(str, "[%99[^]]]:%u%n", buf, &port, &len) == 2 &&
              inet_pton(AF_INET6, buf, &sa->sin6.sin6_addr)) {
      /* IPv6 address, e.g. [3ffe:2a00:100:7031::1]:8080 */
      sa->sin6.sin6_family = AF_INET6;
      sa->sin.sin_port = htons((uint16_t) port);
#endif
#ifndef MG_DISABLE_RESOLVER
   } else if (strlen(str) < host_len &&
              sscanf(str, "%[^ :]:%u%n", host, &port, &len) == 2) {
      sa->sin.sin_port = htons((uint16_t) port);
      if (mg_resolve_from_hosts_file(host, sa) != 0) {
         return 0;
      }
#endif
   } else if (sscanf(str, ":%u%n", &port, &len) == 1 ||
              sscanf(str, "%u%n", &port, &len) == 1) {
      /* If only port is specified, bind to IPv4, INADDR_ANY */
      sa->sin.sin_port = htons((uint16_t) port);
   } else {
      return -1;
   }
   
   ch = str[len]; /* Character that follows the address */
   return port < 0xffffUL && (ch == '\0' || ch == ',' || isspace(ch)) ? len : -1;
}

#ifdef MG_ENABLE_SSL
/*
 * Certificate generation script is at
 * https://github.com/cesanta/mongoose/blob/master/scripts/generate_ssl_certificates.sh
 */

#ifndef MG_DISABLE_PFS
/*
 * Cipher suite options used for TLS negotiation.
 * https://wiki.mozilla.org/Security/Server_Side_TLS#Recommended_configurations
 */
static const char mg_s_cipher_list[] =
#if defined(MG_SSL_CRYPTO_MODERN)
"ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:"
"ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:"
"DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:"
"ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:"
"ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:"
"ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:"
"DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:"
"DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:"
"!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK"
#elif defined(MG_SSL_CRYPTO_OLD)
"ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:"
"ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:"
"DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:"
"ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:"
"ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:"
"ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:"
"DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:"
"DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:ECDHE-RSA-DES-CBC3-SHA:"
"ECDHE-ECDSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:"
"AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:DES-CBC3-SHA:"
"HIGH:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:"
"!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA"
#else /* Default - intermediate. */
"ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:"
"ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:"
"DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:"
"ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:"
"ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:"
"ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:"
"DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:"
"DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:"
"AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:"
"DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:"
"!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA"
#endif
;

/*
 * Default DH params for PFS cipher negotiation. This is a 2048-bit group.
 * Will be used if none are provided by the user in the certificate file.
 */
static const char mg_s_default_dh_params[] =
"\
-----BEGIN DH PARAMETERS-----\n\
MIIBCAKCAQEAlvbgD/qh9znWIlGFcV0zdltD7rq8FeShIqIhkQ0C7hYFThrBvF2E\n\
Z9bmgaP+sfQwGpVlv9mtaWjvERbu6mEG7JTkgmVUJrUt/wiRzwTaCXBqZkdUO8Tq\n\
+E6VOEQAilstG90ikN1Tfo+K6+X68XkRUIlgawBTKuvKVwBhuvlqTGerOtnXWnrt\n\
ym//hd3cd5PBYGBix0i7oR4xdghvfR2WLVu0LgdThTBb6XP7gLd19cQ1JuBtAajZ\n\
wMuPn7qlUkEFDIkAZy59/Hue/H2Q2vU/JsvVhHWCQBL4F1ofEAt50il6ZxR1QfFK\n\
9VGKDC4oOgm9DlxwwBoC2FjqmvQlqVV3kwIBAg==\n\
-----END DH PARAMETERS-----\n";
#endif

static int mg_use_ca_cert(SSL_CTX *ctx, const char *cert) {
   if (ctx == NULL) {
      return -1;
   } else if (cert == NULL || cert[0] == '\0') {
      return 0;
   }
   SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, 0);
   return SSL_CTX_load_verify_locations(ctx, cert, NULL) == 1 ? 0 : -2;
}

static int mg_use_cert(SSL_CTX *ctx, const char *pem_file) {
   if (ctx == NULL) {
      return -1;
   } else if (pem_file == NULL || pem_file[0] == '\0') {
      return 0;
   } else if (SSL_CTX_use_certificate_file(ctx, pem_file, 1) == 0 ||
              SSL_CTX_use_PrivateKey_file(ctx, pem_file, 1) == 0) {
      return -2;
   } else {
#ifndef MG_DISABLE_PFS
      BIO *bio = NULL;
      DH *dh = NULL;
      
      /* Try to read DH parameters from the cert/key file. */
      bio = BIO_new_file(pem_file, "r");
      if (bio != NULL) {
         dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
         BIO_free(bio);
      }
      /*
       * If there are no DH params in the file, fall back to hard-coded ones.
       * Not ideal, but better than nothing.
       */
      if (dh == NULL) {
         bio = BIO_new_mem_buf((void *) mg_s_default_dh_params, -1);
         dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
         BIO_free(bio);
      }
      if (dh != NULL) {
         SSL_CTX_set_tmp_dh(ctx, dh);
         SSL_CTX_set_options(ctx, SSL_OP_SINGLE_DH_USE);
         DH_free(dh);
      }
#endif
      SSL_CTX_set_mode(ctx, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
      SSL_CTX_use_certificate_chain_file(ctx, pem_file);
      return 0;
   }
}

/*
 * Turn the connection into SSL mode.
 * `cert` is the certificate file in PEM format. For listening connections,
 * certificate file must contain private key and server certificate,
 * concatenated. It may also contain DH params - these will be used for more
 * secure key exchange. `ca_cert` is a certificate authority (CA) PEM file, and
 * it is optional (can be set to NULL). If `ca_cert` is non-NULL, then
 * the connection is so-called two-way-SSL: other peer's certificate is
 * checked against the `ca_cert`.
 *
 * Handy OpenSSL command to generate test self-signed certificate:
 *
 *    openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 999
 *
 * Return NULL on success, or error message on failure.
 */
const char *mg_set_ssl(struct mg_connection *nc, const char *cert,
                       const char *ca_cert) {
   const char *result = NULL;
   DBG(("%p %s %s", nc, (cert ? cert : ""), (ca_cert ? ca_cert : "")));
   
   if (nc->flags & MG_F_UDP) {
      return "SSL for UDP is not supported";
   }
   
   if (nc->ssl != NULL) {
      SSL_free(nc->ssl);
      nc->ssl = NULL;
   }
   if (nc->ssl_ctx != NULL) {
      SSL_CTX_free(nc->ssl_ctx);
      nc->ssl_ctx = NULL;
   }
   
   if ((nc->flags & MG_F_LISTENING) &&
       (nc->ssl_ctx = SSL_CTX_new(SSLv23_server_method())) == NULL) {
      result = "SSL_CTX_new() failed";
   } else if (!(nc->flags & MG_F_LISTENING) &&
              (nc->ssl_ctx = SSL_CTX_new(SSLv23_client_method())) == NULL) {
      result = "SSL_CTX_new() failed";
   } else if (mg_use_cert(nc->ssl_ctx, cert) != 0) {
      result = "Invalid ssl cert";
   } else if (mg_use_ca_cert(nc->ssl_ctx, ca_cert) != 0) {
      result = "Invalid CA cert";
   } else if (!(nc->flags & MG_F_LISTENING) &&
              (nc->ssl = SSL_new(nc->ssl_ctx)) == NULL) {
      result = "SSL_new() failed";
   } else if (!(nc->flags & MG_F_LISTENING) && nc->sock != INVALID_SOCKET) {
      /*
       * Socket is open here only if we are connecting to IP address
       * and does not open if we are connecting using async DNS resolver
       */
      SSL_set_fd(nc->ssl, nc->sock);
   }
   
#ifndef MG_DISABLE_PFS
   SSL_CTX_set_cipher_list(nc->ssl_ctx, mg_s_cipher_list);
#endif
   return result;
}
#endif /* MG_ENABLE_SSL */

struct mg_connection *mg_if_accept_new_conn(struct mg_connection *lc) {
   struct mg_add_sock_opts opts;
   struct mg_connection *nc;
   memset(&opts, 0, sizeof(opts));
   nc = mg_create_connection(lc->mgr, lc->handler, opts);
   if (nc == NULL) return NULL;
   nc->listener = lc;
   nc->proto_handler = lc->proto_handler;
   nc->user_data = lc->user_data;
   nc->recv_mbuf_limit = lc->recv_mbuf_limit;
   mg_add_conn(nc->mgr, nc);
   DBG(("%p %p %d %d, %p %p", lc, nc, nc->sock, (int) nc->flags, lc->ssl_ctx,
        nc->ssl));
   return nc;
}

void mg_if_accept_tcp_cb(struct mg_connection *nc, union socket_address *sa,
                         size_t sa_len) {
   (void) sa_len;
   nc->sa = *sa;
   mg_call(nc, NULL, MG_EV_ACCEPT, &nc->sa);
}

void mg_send(struct mg_connection *nc, const void *buf, int len) {
   nc->last_io_time = mg_time();
   if (nc->flags & MG_F_UDP) {
      mg_if_udp_send(nc, buf, len);
   } else {
      mg_if_tcp_send(nc, buf, len);
   }
#if !defined(NO_LIBC) && !defined(MG_DISABLE_HEXDUMP)
   if (nc->mgr && nc->mgr->hexdump_file != NULL) {
      mg_hexdump_connection(nc, nc->mgr->hexdump_file, buf, len, MG_EV_SEND);
   }
#endif
}

void mg_if_sent_cb(struct mg_connection *nc, int num_sent) {
   if (num_sent < 0) {
      nc->flags |= MG_F_CLOSE_IMMEDIATELY;
   }
   mg_call(nc, NULL, MG_EV_SEND, &num_sent);
}

static void mg_recv_common(struct mg_connection *nc, void *buf, int len) {
   DBG(("%p %d %u", nc, len, (unsigned int) nc->recv_mbuf.len));
   if (nc->flags & MG_F_CLOSE_IMMEDIATELY) {
      DBG(("%p discarded %d bytes", nc, len));
      /*
       * This connection will not survive next poll. Do not deliver events,
       * send data to /dev/null without acking.
       */
      MG_FREE(buf);
      return;
   }
   nc->last_io_time = mg_time();
   if (nc->recv_mbuf.len == 0) {
      /* Adopt buf as recv_mbuf's backing store. */
      mbuf_free(&nc->recv_mbuf);
      nc->recv_mbuf.buf = (char *) buf;
      nc->recv_mbuf.size = nc->recv_mbuf.len = len;
   } else {
      mbuf_append(&nc->recv_mbuf, buf, len);
      MG_FREE(buf);
   }
   mg_call(nc, NULL, MG_EV_RECV, &len);
}

void mg_if_recv_tcp_cb(struct mg_connection *nc, void *buf, int len) {
   mg_recv_common(nc, buf, len);
}

void mg_if_recv_udp_cb(struct mg_connection *nc, void *buf, int len,
                       union socket_address *sa, size_t sa_len) {
   assert(nc->flags & MG_F_UDP);
   DBG(("%p %u", nc, (unsigned int) len));
   if (nc->flags & MG_F_LISTENING) {
      struct mg_connection *lc = nc;
      /*
       * Do we have an existing connection for this source?
       * This is very inefficient for long connection lists.
       */
      for (nc = mg_next(lc->mgr, NULL); nc != NULL; nc = mg_next(lc->mgr, nc)) {
         if (memcmp(&nc->sa.sa, &sa->sa, sa_len) == 0 && nc->listener == lc) {
            break;
         }
      }
      if (nc == NULL) {
         struct mg_add_sock_opts opts;
         memset(&opts, 0, sizeof(opts));
         /* Create fake connection w/out sock initialization */
         nc = mg_create_connection_base(lc->mgr, lc->handler, opts);
         if (nc != NULL) {
            nc->sock = lc->sock;
            nc->listener = lc;
            nc->sa = *sa;
            nc->proto_handler = lc->proto_handler;
            nc->user_data = lc->user_data;
            nc->recv_mbuf_limit = lc->recv_mbuf_limit;
            nc->flags = MG_F_UDP;
            mg_add_conn(lc->mgr, nc);
            mg_call(nc, NULL, MG_EV_ACCEPT, &nc->sa);
         } else {
            DBG(("OOM"));
            /* No return here, we still need to drop on the floor */
         }
      }
   }
   if (nc != NULL) {
      mg_recv_common(nc, buf, len);
   } else {
      /* Drop on the floor. */
      MG_FREE(buf);
      mg_if_recved(nc, len);
   }
}

/*
 * Schedules an async connect for a resolved address and proto.
 * Called from two places: `mg_connect_opt()` and from async resolver.
 * When called from the async resolver, it must trigger `MG_EV_CONNECT` event
 * with a failure flag to indicate connection failure.
 */
MG_INTERNAL struct mg_connection *mg_do_connect(struct mg_connection *nc,
                                                int proto,
                                                union socket_address *sa) {
   DBG(("%p %s://%s:%hu", nc, proto == SOCK_DGRAM ? "udp" : "tcp",
        inet_ntoa(sa->sin.sin_addr), ntohs(sa->sin.sin_port)));
   
   nc->flags |= MG_F_CONNECTING;
   if (proto == SOCK_DGRAM) {
      mg_if_connect_udp(nc);
   } else {
      mg_if_connect_tcp(nc, sa);
   }
   mg_add_conn(nc->mgr, nc);
   return nc;
}

void mg_if_connect_cb(struct mg_connection *nc, int err) {
   DBG(("%p connect, err=%d", nc, err));
   nc->flags &= ~MG_F_CONNECTING;
   if (err != 0) {
      nc->flags |= MG_F_CLOSE_IMMEDIATELY;
   }
   mg_call(nc, NULL, MG_EV_CONNECT, &err);
}

#ifndef MG_DISABLE_RESOLVER
/*
 * Callback for the async resolver on mg_connect_opt() call.
 * Main task of this function is to trigger MG_EV_CONNECT event with
 *    either failure (and dealloc the connection)
 *    or success (and proceed with connect()
 */
static void resolve_cb(struct mg_dns_message *msg, void *data,
                       enum mg_resolve_err e) {
   struct mg_connection *nc = (struct mg_connection *) data;
   int i;
   int failure = -1;
   
   nc->flags &= ~MG_F_RESOLVING;
   if (msg != NULL) {
      /*
       * Take the first DNS A answer and run...
       */
      for (i = 0; i < msg->num_answers; i++) {
         if (msg->answers[i].rtype == MG_DNS_A_RECORD) {
            /*
             * Async resolver guarantees that there is at least one answer.
             * TODO(lsm): handle IPv6 answers too
             */
            mg_dns_parse_record_data(msg, &msg->answers[i], &nc->sa.sin.sin_addr,
                                     4);
            mg_do_connect(nc, nc->flags & MG_F_UDP ? SOCK_DGRAM : SOCK_STREAM,
                          &nc->sa);
            return;
         }
      }
   }
   
   if (e == MG_RESOLVE_TIMEOUT) {
      double now = mg_time();
      mg_call(nc, NULL, MG_EV_TIMER, &now);
   }
   
   /*
    * If we get there was no MG_DNS_A_RECORD in the answer
    */
   mg_call(nc, NULL, MG_EV_CONNECT, &failure);
   mg_call(nc, NULL, MG_EV_CLOSE, NULL);
   mg_destroy_conn(nc);
}
#endif

struct mg_connection *mg_connect(struct mg_mgr *mgr, const char *address,
                                 mg_event_handler_t callback) {
   struct mg_connect_opts opts;
   memset(&opts, 0, sizeof(opts));
   return mg_connect_opt(mgr, address, callback, opts);
}

struct mg_connection *mg_connect_opt(struct mg_mgr *mgr, const char *address,
                                     mg_event_handler_t callback,
                                     struct mg_connect_opts opts) {
   struct mg_connection *nc = NULL;
   int proto, rc;
   struct mg_add_sock_opts add_sock_opts;
   char host[MG_MAX_HOST_LEN];
   
   MG_COPY_COMMON_CONNECTION_OPTIONS(&add_sock_opts, &opts);
   
   if ((nc = mg_create_connection(mgr, callback, add_sock_opts)) == NULL) {
      return NULL;
   } else if ((rc = mg_parse_address(address, &nc->sa, &proto, host,
                                     sizeof(host))) < 0) {
      /* Address is malformed */
      MG_SET_PTRPTR(opts.error_string, "cannot parse address");
      mg_destroy_conn(nc);
      return NULL;
   }
   nc->flags |= opts.flags & _MG_ALLOWED_CONNECT_FLAGS_MASK;
   nc->flags |= (proto == SOCK_DGRAM) ? MG_F_UDP : 0;
   nc->user_data = opts.user_data;
   
#ifdef MG_ENABLE_SSL
   if (opts.ssl_cert != NULL || opts.ssl_ca_cert != NULL) {
      const char *err = mg_set_ssl(nc, opts.ssl_cert, opts.ssl_ca_cert);
      if (err != NULL) {
         MG_SET_PTRPTR(opts.error_string, err);
         mg_destroy_conn(nc);
         return NULL;
      }
      if (opts.ssl_ca_cert != NULL && (opts.ssl_server_name == NULL ||
                                       strcmp(opts.ssl_server_name, "*") != 0)) {
         if (opts.ssl_server_name == NULL) opts.ssl_server_name = host;
#ifdef SSL_KRYPTON
         SSL_CTX_kr_set_verify_name(nc->ssl_ctx, opts.ssl_server_name);
#else
         /* TODO(rojer): Implement server name verification on OpenSSL. */
         MG_SET_PTRPTR(opts.error_string,
                       "Server name verification requested but is not supported");
         mg_destroy_conn(nc);
         return NULL;
#endif /* SSL_KRYPTON */
      }
   }
#endif /* MG_ENABLE_SSL */
   
   if (rc == 0) {
#ifndef MG_DISABLE_RESOLVER
      /*
       * DNS resolution is required for host.
       * mg_parse_address() fills port in nc->sa, which we pass to resolve_cb()
       */
      struct mg_connection *dns_conn = NULL;
      struct mg_resolve_async_opts o;
      memset(&o, 0, sizeof(o));
      o.dns_conn = &dns_conn;
      if (mg_resolve_async_opt(nc->mgr, host, MG_DNS_A_RECORD, resolve_cb, nc,
                               o) != 0) {
         MG_SET_PTRPTR(opts.error_string, "cannot schedule DNS lookup");
         mg_destroy_conn(nc);
         return NULL;
      }
      nc->priv_2 = dns_conn;
      nc->flags |= MG_F_RESOLVING;
      return nc;
#else
      MG_SET_PTRPTR(opts.error_string, "Resolver is disabled");
      mg_destroy_conn(nc);
      return NULL;
#endif
   } else {
      /* Address is parsed and resolved to IP. proceed with connect() */
      return mg_do_connect(nc, proto, &nc->sa);
   }
}

struct mg_connection *mg_bind(struct mg_mgr *srv, const char *address,
                              mg_event_handler_t event_handler) {
   struct mg_bind_opts opts;
   memset(&opts, 0, sizeof(opts));
   return mg_bind_opt(srv, address, event_handler, opts);
}

struct mg_connection *mg_bind_opt(struct mg_mgr *mgr, const char *address,
                                  mg_event_handler_t callback,
                                  struct mg_bind_opts opts) {
   union socket_address sa;
   struct mg_connection *nc = NULL;
   int proto, rc;
   struct mg_add_sock_opts add_sock_opts;
   char host[MG_MAX_HOST_LEN];
   
   MG_COPY_COMMON_CONNECTION_OPTIONS(&add_sock_opts, &opts);
   
   if (mg_parse_address(address, &sa, &proto, host, sizeof(host)) <= 0) {
      MG_SET_PTRPTR(opts.error_string, "cannot parse address");
      return NULL;
   }
   
   nc = mg_create_connection(mgr, callback, add_sock_opts);
   if (nc == NULL) {
      return NULL;
   }
   
   nc->sa = sa;
   nc->flags |= MG_F_LISTENING;
   if (proto == SOCK_DGRAM) {
      nc->flags |= MG_F_UDP;
      rc = mg_if_listen_udp(nc, &nc->sa);
   } else {
      rc = mg_if_listen_tcp(nc, &nc->sa);
   }
   if (rc != 0) {
      DBG(("Failed to open listener: %d", rc));
      MG_SET_PTRPTR(opts.error_string, "failed to open listener");
      mg_destroy_conn(nc);
      return NULL;
   }
#ifdef MG_ENABLE_SSL
   if (opts.ssl_cert != NULL || opts.ssl_ca_cert != NULL) {
      const char *err = mg_set_ssl(nc, opts.ssl_cert, opts.ssl_ca_cert);
      if (err != NULL) {
         MG_SET_PTRPTR(opts.error_string, err);
         mg_destroy_conn(nc);
         return NULL;
      }
   }
#endif /* MG_ENABLE_SSL */
   mg_add_conn(nc->mgr, nc);
   
   return nc;
}

struct mg_connection *mg_next(struct mg_mgr *s, struct mg_connection *conn) {
   return conn == NULL ? s->active_connections : conn->next;
}

#ifndef MG_DISABLE_SOCKETPAIR
void mg_broadcast(struct mg_mgr *mgr, mg_event_handler_t cb, void *data,
                  size_t len) {
   struct ctl_msg ctl_msg;
   
   /*
    * Mongoose manager has a socketpair, `struct mg_mgr::ctl`,
    * where `mg_broadcast()` pushes the message.
    * `mg_mgr_poll()` wakes up, reads a message from the socket pair, and calls
    * specified callback for each connection. Thus the callback function executes
    * in event manager thread.
    */
   if (mgr->ctl[0] != INVALID_SOCKET && data != NULL &&
       len < sizeof(ctl_msg.message)) {
      size_t dummy;
      
      ctl_msg.callback = cb;
      memcpy(ctl_msg.message, data, len);
      dummy = MG_SEND_FUNC(mgr->ctl[0], (char *) &ctl_msg,
                           offsetof(struct ctl_msg, message) + len, 0);
      dummy = MG_RECV_FUNC(mgr->ctl[0], (char *) &len, 1, 0);
      (void) dummy; /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25509 */
   }
}
#endif /* MG_DISABLE_SOCKETPAIR */

static int isbyte(int n) {
   return n >= 0 && n <= 255;
}

static int parse_net(const char *spec, uint32_t *net, uint32_t *mask) {
   int n, a, b, c, d, slash = 32, len = 0;
   
   if ((sscanf(spec, "%d.%d.%d.%d/%d%n", &a, &b, &c, &d, &slash, &n) == 5 ||
        sscanf(spec, "%d.%d.%d.%d%n", &a, &b, &c, &d, &n) == 4) &&
       isbyte(a) && isbyte(b) && isbyte(c) && isbyte(d) && slash >= 0 &&
       slash < 33) {
      len = n;
      *net =
      ((uint32_t) a << 24) | ((uint32_t) b << 16) | ((uint32_t) c << 8) | d;
      *mask = slash ? 0xffffffffU << (32 - slash) : 0;
   }
   
   return len;
}

int mg_check_ip_acl(const char *acl, uint32_t remote_ip) {
   int allowed, flag;
   uint32_t net, mask;
   struct mg_str vec;
   
   /* If any ACL is set, deny by default */
   allowed = (acl == NULL || *acl == '\0') ? '+' : '-';
   
   while ((acl = mg_next_comma_list_entry(acl, &vec, NULL)) != NULL) {
      flag = vec.p[0];
      if ((flag != '+' && flag != '-') ||
          parse_net(&vec.p[1], &net, &mask) == 0) {
         return -1;
      }
      
      if (net == (remote_ip & mask)) {
         allowed = flag;
      }
   }
   
   DBG(("%08x %c", remote_ip, allowed));
   return allowed == '+';
}

/* Move data from one connection to another */
void mg_forward(struct mg_connection *from, struct mg_connection *to) {
   mg_send(to, from->recv_mbuf.buf, from->recv_mbuf.len);
   mbuf_remove(&from->recv_mbuf, from->recv_mbuf.len);
}

double mg_set_timer(struct mg_connection *c, double timestamp) {
   double result = c->ev_timer_time;
   c->ev_timer_time = timestamp;
   /*
    * If this connection is resolving, it's not in the list of active
    * connections, so not processed yet. It has a DNS resolver connection
    * linked to it. Set up a timer for the DNS connection.
    */
   DBG(("%p %p %d -> %lu", c, c->priv_2, c->flags & MG_F_RESOLVING,
        (unsigned long) timestamp));
   if ((c->flags & MG_F_RESOLVING) && c->priv_2 != NULL) {
      ((struct mg_connection *) c->priv_2)->ev_timer_time = timestamp;
   }
   return result;
}

struct mg_connection *mg_add_sock_opt(struct mg_mgr *s, sock_t sock,
                                      mg_event_handler_t callback,
                                      struct mg_add_sock_opts opts) {
   struct mg_connection *nc = mg_create_connection_base(s, callback, opts);
   if (nc != NULL) {
      mg_sock_set(nc, sock);
      mg_add_conn(nc->mgr, nc);
   }
   return nc;
}

struct mg_connection *mg_add_sock(struct mg_mgr *s, sock_t sock,
                                  mg_event_handler_t callback) {
   struct mg_add_sock_opts opts;
   memset(&opts, 0, sizeof(opts));
   return mg_add_sock_opt(s, sock, callback, opts);
}

double mg_time() {
   return cs_time();
}
#ifdef MG_MODULE_LINES
#line 1 "./src/net_if_socket.c"
#endif
/*
 * Copyright (c) 2014-2016 Cesanta Software Limited
 * All rights reserved
 */

#ifndef MG_DISABLE_SOCKET_IF

/* Amalgamated: #include "mongoose/src/internal.h" */
/* Amalgamated: #include "mongoose/src/util.h" */

#define MG_TCP_RECV_BUFFER_SIZE 1024
#define MG_UDP_RECV_BUFFER_SIZE 1500

static sock_t mg_open_listening_socket(union socket_address *sa, int proto);
#ifdef MG_ENABLE_SSL
static void mg_ssl_begin(struct mg_connection *nc);
static int mg_ssl_err(struct mg_connection *conn, int res);
#endif

void mg_set_non_blocking_mode(sock_t sock) {
#ifdef _WIN32
   unsigned long on = 1;
   ioctlsocket(sock, FIONBIO, &on);
#elif defined(MG_SOCKET_SIMPLELINK)
   SlSockNonblocking_t opt;
   opt.NonblockingEnabled = 1;
   sl_SetSockOpt(sock, SL_SOL_SOCKET, SL_SO_NONBLOCKING, &opt, sizeof(opt));
#else
   int flags = fcntl(sock, F_GETFL, 0);
   fcntl(sock, F_SETFL, flags | O_NONBLOCK);
#endif
}

int mg_is_error(int n) {
#ifdef MG_SOCKET_SIMPLELINK
   DBG(("n = %d, errno = %d", n, errno));
   if (n < 0) errno = n;
#endif
   return n == 0 || (n < 0 && errno != EINTR && errno != EINPROGRESS &&
                     errno != EAGAIN && errno != EWOULDBLOCK
#ifdef MG_SOCKET_SIMPLELINK
                     && errno != SL_EALREADY
#endif
#ifdef _WIN32
                     && WSAGetLastError() != WSAEINTR &&
                     WSAGetLastError() != WSAEWOULDBLOCK
#endif
                     );
}

void mg_if_connect_tcp(struct mg_connection *nc,
                       const union socket_address *sa) {
   int rc;
   nc->sock = socket(AF_INET, SOCK_STREAM, 0);
   if (nc->sock == INVALID_SOCKET) {
      nc->err = errno ? errno : 1;
      return;
   }
#if !defined(MG_SOCKET_SIMPLELINK) && !defined(MG_ESP8266)
   mg_set_non_blocking_mode(nc->sock);
#endif
   rc = connect(nc->sock, &sa->sa, sizeof(sa->sin));
   nc->err = mg_is_error(rc) ? errno : 0;
   DBG(("%p sock %d err %d", nc, nc->sock, nc->err));
}

void mg_if_connect_udp(struct mg_connection *nc) {
   nc->sock = socket(AF_INET, SOCK_DGRAM, 0);
   if (nc->sock == INVALID_SOCKET) {
      nc->err = errno ? errno : 1;
      return;
   }
   nc->err = 0;
}

int mg_if_listen_tcp(struct mg_connection *nc, union socket_address *sa) {
   sock_t sock = mg_open_listening_socket(sa, SOCK_STREAM);
   if (sock == INVALID_SOCKET) {
      return (errno ? errno : 1);
   }
   mg_sock_set(nc, sock);
   return 0;
}

int mg_if_listen_udp(struct mg_connection *nc, union socket_address *sa) {
   sock_t sock = mg_open_listening_socket(sa, SOCK_DGRAM);
   if (sock == INVALID_SOCKET) return (errno ? errno : 1);
   mg_sock_set(nc, sock);
   return 0;
}

void mg_if_tcp_send(struct mg_connection *nc, const void *buf, size_t len) {
   mbuf_append(&nc->send_mbuf, buf, len);
}

void mg_if_udp_send(struct mg_connection *nc, const void *buf, size_t len) {
   mbuf_append(&nc->send_mbuf, buf, len);
}

void mg_if_recved(struct mg_connection *nc, size_t len) {
   (void) nc;
   (void) len;
}

int mg_if_create_conn(struct mg_connection *nc) {
   (void) nc;
   return 1;
}

void mg_if_destroy_conn(struct mg_connection *nc) {
   if (nc->sock == INVALID_SOCKET) return;
   if (!(nc->flags & MG_F_UDP)) {
      closesocket(nc->sock);
   } else {
      /* Only close outgoing UDP sockets or listeners. */
      if (nc->listener == NULL) closesocket(nc->sock);
   }
   /*
    * avoid users accidentally double close a socket
    * because it can lead to difficult to debug situations.
    * It would happen only if reusing a destroyed mg_connection
    * but it's not always possible to run the code through an
    * address sanitizer.
    */
   nc->sock = INVALID_SOCKET;
}

static int mg_accept_conn(struct mg_connection *lc) {
   struct mg_connection *nc;
   union socket_address sa;
   socklen_t sa_len = sizeof(sa);
   /* NOTE(lsm): on Windows, sock is always > FD_SETSIZE */
   sock_t sock = accept(lc->sock, &sa.sa, &sa_len);
   if (sock == INVALID_SOCKET) {
      if (mg_is_error(-1)) DBG(("%p: failed to accept: %d", lc, errno));
      return 0;
   }
   nc = mg_if_accept_new_conn(lc);
   if (nc == NULL) {
      closesocket(sock);
      return 0;
   }
   DBG(("%p conn from %s:%d", nc, inet_ntoa(sa.sin.sin_addr),
        ntohs(sa.sin.sin_port)));
   mg_sock_set(nc, sock);
#ifdef MG_ENABLE_SSL
   if (lc->ssl_ctx != NULL) {
      nc->ssl = SSL_new(lc->ssl_ctx);
      if (nc->ssl == NULL || SSL_set_fd(nc->ssl, sock) != 1) {
         DBG(("SSL error"));
         mg_close_conn(nc);
      }
   } else
#endif
      {
      mg_if_accept_tcp_cb(nc, &sa, sa_len);
      }
   return 1;
}

/* 'sa' must be an initialized address to bind to */
static sock_t mg_open_listening_socket(union socket_address *sa, int proto) {
   socklen_t sa_len =
   (sa->sa.sa_family == AF_INET) ? sizeof(sa->sin) : sizeof(sa->sin6);
   sock_t sock = INVALID_SOCKET;
#if !defined(MG_SOCKET_SIMPLELINK) && !defined(MG_LWIP)
   int on = 1;
#endif
   
   if ((sock = socket(sa->sa.sa_family, proto, 0)) != INVALID_SOCKET &&
#if !defined(MG_SOCKET_SIMPLELINK) && \
!defined(MG_LWIP) /* SimpleLink and LWIP don't support either */
#if defined(_WIN32) && defined(SO_EXCLUSIVEADDRUSE)
       /* "Using SO_REUSEADDR and SO_EXCLUSIVEADDRUSE" http://goo.gl/RmrFTm */
       !setsockopt(sock, SOL_SOCKET, SO_EXCLUSIVEADDRUSE, (void *) &on,
                   sizeof(on)) &&
#endif
       
#if !defined(_WIN32) || !defined(SO_EXCLUSIVEADDRUSE)
       /*
        * SO_RESUSEADDR is not enabled on Windows because the semantics of
        * SO_REUSEADDR on UNIX and Windows is different. On Windows,
        * SO_REUSEADDR allows to bind a socket to a port without error even if
        * the port is already open by another program. This is not the behavior
        * SO_REUSEADDR was designed for, and leads to hard-to-track failure
        * scenarios. Therefore, SO_REUSEADDR was disabled on Windows unless
        * SO_EXCLUSIVEADDRUSE is supported and set on a socket.
        */
       !setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *) &on, sizeof(on)) &&
#endif
#endif /* !MG_SOCKET_SIMPLELINK && !MG_LWIP */
       
       !bind(sock, &sa->sa, sa_len) &&
       (proto == SOCK_DGRAM || listen(sock, SOMAXCONN) == 0)) {
#if !defined(MG_SOCKET_SIMPLELINK) && \
!defined(MG_LWIP) /* TODO(rojer): Fix this. */
      mg_set_non_blocking_mode(sock);
      /* In case port was set to 0, get the real port number */
      (void) getsockname(sock, &sa->sa, &sa_len);
#endif
   } else if (sock != INVALID_SOCKET) {
      closesocket(sock);
      sock = INVALID_SOCKET;
   }
   
   return sock;
}

static void mg_write_to_socket(struct mg_connection *nc) {
   struct mbuf *io = &nc->send_mbuf;
   int n = 0;
   
#ifdef MG_LWIP
   /* With LWIP we don't know if the socket is ready */
   if (io->len == 0) return;
#endif
   
   assert(io->len > 0);
   
   if (nc->flags & MG_F_UDP) {
      int n =
      sendto(nc->sock, io->buf, io->len, 0, &nc->sa.sa, sizeof(nc->sa.sin));
      DBG(("%p %d %d %d %s:%hu", nc, nc->sock, n, errno,
           inet_ntoa(nc->sa.sin.sin_addr), ntohs(nc->sa.sin.sin_port)));
      if (n > 0) {
         mbuf_remove(io, n);
      }
      mg_if_sent_cb(nc, n);
      return;
   }
   
#ifdef MG_ENABLE_SSL
   if (nc->ssl != NULL) {
      if (nc->flags & MG_F_SSL_HANDSHAKE_DONE) {
         n = SSL_write(nc->ssl, io->buf, io->len);
         DBG(("%p %d bytes -> %d (SSL)", nc, n, nc->sock));
         if (n <= 0) {
            int ssl_err = mg_ssl_err(nc, n);
            if (ssl_err == SSL_ERROR_WANT_READ || ssl_err == SSL_ERROR_WANT_WRITE) {
               return; /* Call us again */
            }
         } else {
            /* Successful SSL operation, clear off SSL wait flags */
            nc->flags &= ~(MG_F_WANT_READ | MG_F_WANT_WRITE);
         }
      } else {
         mg_ssl_begin(nc);
         return;
      }
   } else
#endif
      {
      n = (int) MG_SEND_FUNC(nc->sock, io->buf, io->len, 0);
      DBG(("%p %d bytes -> %d", nc, n, nc->sock));
      if (n < 0 && !mg_is_error(n)) return;
      }
   
   if (n > 0) {
      mbuf_remove(io, n);
   }
   mg_if_sent_cb(nc, n);
}

MG_INTERNAL size_t recv_avail_size(struct mg_connection *conn, size_t max) {
   size_t avail;
   if (conn->recv_mbuf_limit < conn->recv_mbuf.len) return 0;
   avail = conn->recv_mbuf_limit - conn->recv_mbuf.len;
   return avail > max ? max : avail;
}

static void mg_read_from_socket(struct mg_connection *conn) {
   int n = 0;
   char *buf = (char *) MG_MALLOC(MG_TCP_RECV_BUFFER_SIZE);
   
   if (buf == NULL) {
      DBG(("OOM"));
      return;
   }
   
#ifdef MG_ENABLE_SSL
   if (conn->ssl != NULL) {
      if (conn->flags & MG_F_SSL_HANDSHAKE_DONE) {
         /* SSL library may have more bytes ready to read then we ask to read.
          * Therefore, read in a loop until we read everything. Without the loop,
          * we skip to the next select() cycle which can just timeout. */
         while ((n = SSL_read(conn->ssl, buf, MG_TCP_RECV_BUFFER_SIZE)) > 0) {
            DBG(("%p %d bytes <- %d (SSL)", conn, n, conn->sock));
            mg_if_recv_tcp_cb(conn, buf, n);
            buf = NULL;
            if (conn->flags & MG_F_CLOSE_IMMEDIATELY) break;
            /* buf has been freed, we need a new one. */
            buf = (char *) MG_MALLOC(MG_TCP_RECV_BUFFER_SIZE);
            if (buf == NULL) break;
         }
         MG_FREE(buf);
         mg_ssl_err(conn, n);
      } else {
         MG_FREE(buf);
         mg_ssl_begin(conn);
         return;
      }
   } else
#endif
      {
      n = (int) MG_RECV_FUNC(conn->sock, buf,
                             recv_avail_size(conn, MG_TCP_RECV_BUFFER_SIZE), 0);
      DBG(("%p %d bytes (PLAIN) <- %d", conn, n, conn->sock));
      if (n > 0) {
         mg_if_recv_tcp_cb(conn, buf, n);
      } else {
         MG_FREE(buf);
      }
      if (n == 0) {
         /* Orderly shutdown of the socket, try flushing output. */
         conn->flags |= MG_F_SEND_AND_CLOSE;
      } else if (mg_is_error(n)) {
         conn->flags |= MG_F_CLOSE_IMMEDIATELY;
      }
      }
}

static int mg_recvfrom(struct mg_connection *nc, union socket_address *sa,
                       socklen_t *sa_len, char **buf) {
   int n;
   *buf = (char *) MG_MALLOC(MG_UDP_RECV_BUFFER_SIZE);
   if (*buf == NULL) {
      DBG(("Out of memory"));
      return -ENOMEM;
   }
   n = recvfrom(nc->sock, *buf, MG_UDP_RECV_BUFFER_SIZE, 0, &sa->sa, sa_len);
   if (n <= 0) {
      DBG(("%p recvfrom: %s", nc, strerror(errno)));
      MG_FREE(*buf);
   }
   return n;
}

static void mg_handle_udp_read(struct mg_connection *nc) {
   char *buf = NULL;
   union socket_address sa;
   socklen_t sa_len = sizeof(sa);
   int n = mg_recvfrom(nc, &sa, &sa_len, &buf);
   DBG(("%p %d bytes from %s:%d", nc, n, inet_ntoa(nc->sa.sin.sin_addr),
        ntohs(nc->sa.sin.sin_port)));
   mg_if_recv_udp_cb(nc, buf, n, &sa, sa_len);
}

#ifdef MG_ENABLE_SSL
static int mg_ssl_err(struct mg_connection *conn, int res) {
   int ssl_err = SSL_get_error(conn->ssl, res);
   DBG(("%p %d -> %d", conn, res, ssl_err));
   if (ssl_err == SSL_ERROR_WANT_READ) {
      conn->flags |= MG_F_WANT_READ;
   } else if (ssl_err == SSL_ERROR_WANT_WRITE) {
      conn->flags |= MG_F_WANT_WRITE;
   } else {
      /* There could be an alert to deliver. Try our best. */
      SSL_write(conn->ssl, "", 0);
      conn->flags |= MG_F_CLOSE_IMMEDIATELY;
   }
   return ssl_err;
}

static void mg_ssl_begin(struct mg_connection *nc) {
   int server_side = (nc->listener != NULL);
   int res = server_side ? SSL_accept(nc->ssl) : SSL_connect(nc->ssl);
   DBG(("%p %d res %d %d", nc, server_side, res, errno));
   
   if (res == 1) {
      nc->flags |= MG_F_SSL_HANDSHAKE_DONE;
      nc->flags &= ~(MG_F_WANT_READ | MG_F_WANT_WRITE);
      
      if (server_side) {
         union socket_address sa;
         socklen_t sa_len = sizeof(sa);
         (void) getpeername(nc->sock, &sa.sa, &sa_len);
         mg_if_accept_tcp_cb(nc, &sa, sa_len);
      } else {
         mg_if_connect_cb(nc, 0);
      }
   } else {
      int ssl_err = mg_ssl_err(nc, res);
      if (ssl_err != SSL_ERROR_WANT_READ && ssl_err != SSL_ERROR_WANT_WRITE) {
         if (!server_side) {
            mg_if_connect_cb(nc, ssl_err);
         }
         nc->flags |= MG_F_CLOSE_IMMEDIATELY;
      }
   }
}
#endif /* MG_ENABLE_SSL */

#define _MG_F_FD_CAN_READ 1
#define _MG_F_FD_CAN_WRITE 1 << 1
#define _MG_F_FD_ERROR 1 << 2

void mg_mgr_handle_conn(struct mg_connection *nc, int fd_flags, double now) {
   DBG(("%p fd=%d fd_flags=%d nc_flags=%lu rmbl=%d smbl=%d", nc, nc->sock,
        fd_flags, nc->flags, (int) nc->recv_mbuf.len, (int) nc->send_mbuf.len));
   
   if (nc->flags & MG_F_CONNECTING) {
      if (fd_flags != 0) {
         int err = 0;
#if !defined(MG_SOCKET_SIMPLELINK) && !defined(MG_ESP8266)
         if (!(nc->flags & MG_F_UDP)) {
            socklen_t len = sizeof(err);
            int ret =
            getsockopt(nc->sock, SOL_SOCKET, SO_ERROR, (char *) &err, &len);
            if (ret != 0) err = 1;
         }
#else
         /* On SimpleLink and ESP8266 we use blocking connect. If we got as far as
          * this, it means connect() was successful.
          * TODO(rojer): Figure out why it fails where blocking succeeds.
          */
#endif
#ifdef MG_ENABLE_SSL
         if (nc->ssl != NULL && err == 0) {
            SSL_set_fd(nc->ssl, nc->sock);
            mg_ssl_begin(nc);
         } else {
            mg_if_connect_cb(nc, err);
         }
#else
         mg_if_connect_cb(nc, err);
#endif
      } else if (nc->err != 0) {
         mg_if_connect_cb(nc, nc->err);
      }
   }
   
   if (fd_flags & _MG_F_FD_CAN_READ) {
      if (nc->flags & MG_F_UDP) {
         mg_handle_udp_read(nc);
      } else {
         if (nc->flags & MG_F_LISTENING) {
            /*
             * We're not looping here, and accepting just one connection at
             * a time. The reason is that eCos does not respect non-blocking
             * flag on a listening socket and hangs in a loop.
             */
            if (fd_flags & _MG_F_FD_CAN_READ) mg_accept_conn(nc);
         } else {
            mg_read_from_socket(nc);
         }
      }
   }
   
   if (!(nc->flags & MG_F_CLOSE_IMMEDIATELY)) {
      if ((fd_flags & _MG_F_FD_CAN_WRITE) && nc->send_mbuf.len > 0) {
         mg_write_to_socket(nc);
      }
      
      if (!(fd_flags & (_MG_F_FD_CAN_READ | _MG_F_FD_CAN_WRITE))) {
         mg_if_poll(nc, now);
      }
      mg_if_timer(nc, now);
   }
   
   DBG(("%p after fd=%d nc_flags=%lu rmbl=%d smbl=%d", nc, nc->sock, nc->flags,
        (int) nc->recv_mbuf.len, (int) nc->send_mbuf.len));
}

#ifndef MG_DISABLE_SOCKETPAIR
static void mg_mgr_handle_ctl_sock(struct mg_mgr *mgr) {
   struct ctl_msg ctl_msg;
   int len =
   (int) MG_RECV_FUNC(mgr->ctl[1], (char *) &ctl_msg, sizeof(ctl_msg), 0);
   size_t dummy = MG_SEND_FUNC(mgr->ctl[1], ctl_msg.message, 1, 0);
   DBG(("read %d from ctl socket", len));
   (void) dummy; /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25509 */
   if (len >= (int) sizeof(ctl_msg.callback) && ctl_msg.callback != NULL) {
      struct mg_connection *nc;
      for (nc = mg_next(mgr, NULL); nc != NULL; nc = mg_next(mgr, nc)) {
         ctl_msg.callback(nc, MG_EV_POLL, ctl_msg.message);
      }
   }
}
#endif

/* Associate a socket to a connection. */
void mg_sock_set(struct mg_connection *nc, sock_t sock) {
   mg_set_non_blocking_mode(sock);
   mg_set_close_on_exec(sock);
   nc->sock = sock;
   DBG(("%p %d", nc, sock));
}

void mg_ev_mgr_init(struct mg_mgr *mgr) {
   (void) mgr;
   DBG(("%p using select()", mgr));
#ifndef MG_DISABLE_SOCKETPAIR
   do {
      mg_socketpair(mgr->ctl, SOCK_DGRAM);
   } while (mgr->ctl[0] == INVALID_SOCKET);
#endif
}

void mg_ev_mgr_free(struct mg_mgr *mgr) {
   (void) mgr;
}

void mg_ev_mgr_add_conn(struct mg_connection *nc) {
   (void) nc;
}

void mg_ev_mgr_remove_conn(struct mg_connection *nc) {
   (void) nc;
}

void mg_add_to_set(sock_t sock, fd_set *set, sock_t *max_fd) {
   if (sock != INVALID_SOCKET
#ifdef __unix__
       && sock < FD_SETSIZE
#endif
       ) {
      FD_SET(sock, set);
      if (*max_fd == INVALID_SOCKET || sock > *max_fd) {
         *max_fd = sock;
      }
   }
}

time_t mg_mgr_poll(struct mg_mgr *mgr, int timeout_ms) {
   double now = mg_time();
   double min_timer;
   struct mg_connection *nc, *tmp;
   struct timeval tv;
   fd_set read_set, write_set, err_set;
   sock_t max_fd = INVALID_SOCKET;
   int num_fds, num_ev, num_timers = 0;
#ifdef __unix__
   int try_dup = 1;
#endif
   
   FD_ZERO(&read_set);
   FD_ZERO(&write_set);
   FD_ZERO(&err_set);
#ifndef MG_DISABLE_SOCKETPAIR
   mg_add_to_set(mgr->ctl[1], &read_set, &max_fd);
#endif
   
   /*
    * Note: it is ok to have connections with sock == INVALID_SOCKET in the list,
    * e.g. timer-only "connections".
    */
   min_timer = 0;
   for (nc = mgr->active_connections, num_fds = 0; nc != NULL; nc = tmp) {
      tmp = nc->next;
      
      if (nc->sock != INVALID_SOCKET) {
         num_fds++;
         
#ifdef __unix__
         /* A hack to make sure all our file descriptos fit into FD_SETSIZE. */
         if (nc->sock >= FD_SETSIZE && try_dup) {
            int new_sock = dup(nc->sock);
            if (new_sock >= 0 && new_sock < FD_SETSIZE) {
               closesocket(nc->sock);
               DBG(("new sock %d -> %d", nc->sock, new_sock));
               nc->sock = new_sock;
            } else {
               try_dup = 0;
            }
         }
#endif
         
         if (!(nc->flags & MG_F_WANT_WRITE) &&
             nc->recv_mbuf.len < nc->recv_mbuf_limit &&
             (!(nc->flags & MG_F_UDP) || nc->listener == NULL)) {
            mg_add_to_set(nc->sock, &read_set, &max_fd);
         }
         
         if (((nc->flags & MG_F_CONNECTING) && !(nc->flags & MG_F_WANT_READ)) ||
             (nc->send_mbuf.len > 0 && !(nc->flags & MG_F_CONNECTING))) {
            mg_add_to_set(nc->sock, &write_set, &max_fd);
            mg_add_to_set(nc->sock, &err_set, &max_fd);
         }
      }
      
      if (nc->ev_timer_time > 0) {
         if (num_timers == 0 || nc->ev_timer_time < min_timer) {
            min_timer = nc->ev_timer_time;
         }
         num_timers++;
      }
   }
   
   /*
    * If there is a timer to be fired earlier than the requested timeout,
    * adjust the timeout.
    */
   if (num_timers > 0) {
      double timer_timeout_ms = (min_timer - mg_time()) * 1000 + 1 /* rounding */;
      if (timer_timeout_ms < timeout_ms) {
         timeout_ms = timer_timeout_ms;
      }
   }
   if (timeout_ms < 0) timeout_ms = 0;
   
   tv.tv_sec = timeout_ms / 1000;
   tv.tv_usec = (timeout_ms % 1000) * 1000;
   
   num_ev = select((int) max_fd + 1, &read_set, &write_set, &err_set, &tv);
   now = mg_time();
   DBG(("select @ %ld num_ev=%d of %d, timeout=%d", (long) now, num_ev, num_fds,
        timeout_ms));
   
#ifndef MG_DISABLE_SOCKETPAIR
   if (num_ev > 0 && mgr->ctl[1] != INVALID_SOCKET &&
       FD_ISSET(mgr->ctl[1], &read_set)) {
      mg_mgr_handle_ctl_sock(mgr);
   }
#endif
   
   for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
      int fd_flags = 0;
      if (nc->sock != INVALID_SOCKET) {
         if (num_ev > 0) {
            fd_flags = (FD_ISSET(nc->sock, &read_set) &&
                        (!(nc->flags & MG_F_UDP) || nc->listener == NULL)
                        ? _MG_F_FD_CAN_READ
                        : 0) |
            (FD_ISSET(nc->sock, &write_set) ? _MG_F_FD_CAN_WRITE : 0) |
            (FD_ISSET(nc->sock, &err_set) ? _MG_F_FD_ERROR : 0);
         }
#ifdef MG_SOCKET_SIMPLELINK
         /* SimpleLink does not report UDP sockets as writeable. */
         if (nc->flags & MG_F_UDP &&
             (nc->send_mbuf.len > 0 || nc->flags & MG_F_CONNECTING)) {
            fd_flags |= _MG_F_FD_CAN_WRITE;
         }
#endif
#ifdef MG_LWIP
         /* With LWIP socket emulation layer, we don't get write events */
         fd_flags |= _MG_F_FD_CAN_WRITE;
#endif
      }
      tmp = nc->next;
      mg_mgr_handle_conn(nc, fd_flags, now);
   }
   
   for (nc = mgr->active_connections; nc != NULL; nc = tmp) {
      tmp = nc->next;
      if ((nc->flags & MG_F_CLOSE_IMMEDIATELY) ||
          (nc->send_mbuf.len == 0 && (nc->flags & MG_F_SEND_AND_CLOSE))) {
         mg_close_conn(nc);
      }
   }
   
   return now;
}

#ifndef MG_DISABLE_SOCKETPAIR
int mg_socketpair(sock_t sp[2], int sock_type) {
   union socket_address sa;
   sock_t sock;
   socklen_t len = sizeof(sa.sin);
   int ret = 0;
   
   sock = sp[0] = sp[1] = INVALID_SOCKET;
   
   (void) memset(&sa, 0, sizeof(sa));
   sa.sin.sin_family = AF_INET;
   sa.sin.sin_port = htons(0);
   sa.sin.sin_addr.s_addr = htonl(0x7f000001); /* 127.0.0.1 */
   
   if ((sock = socket(AF_INET, sock_type, 0)) == INVALID_SOCKET) {
   } else if (bind(sock, &sa.sa, len) != 0) {
   } else if (sock_type == SOCK_STREAM && listen(sock, 1) != 0) {
   } else if (getsockname(sock, &sa.sa, &len) != 0) {
   } else if ((sp[0] = socket(AF_INET, sock_type, 0)) == INVALID_SOCKET) {
   } else if (connect(sp[0], &sa.sa, len) != 0) {
   } else if (sock_type == SOCK_DGRAM &&
              (getsockname(sp[0], &sa.sa, &len) != 0 ||
               connect(sock, &sa.sa, len) != 0)) {
              } else if ((sp[1] = (sock_type == SOCK_DGRAM ? sock
                                   : accept(sock, &sa.sa, &len))) ==
                         INVALID_SOCKET) {
              } else {
                 mg_set_close_on_exec(sp[0]);
                 mg_set_close_on_exec(sp[1]);
                 if (sock_type == SOCK_STREAM) closesocket(sock);
                 ret = 1;
              }
   
   if (!ret) {
      if (sp[0] != INVALID_SOCKET) closesocket(sp[0]);
      if (sp[1] != INVALID_SOCKET) closesocket(sp[1]);
      if (sock != INVALID_SOCKET) closesocket(sock);
      sock = sp[0] = sp[1] = INVALID_SOCKET;
   }
   
   return ret;
}
#endif /* MG_DISABLE_SOCKETPAIR */

#ifndef MG_SOCKET_SIMPLELINK
static void mg_sock_get_addr(sock_t sock, int remote,
                             union socket_address *sa) {
   socklen_t slen = sizeof(*sa);
   memset(sa, 0, slen);
   if (remote) {
      getpeername(sock, &sa->sa, &slen);
   } else {
      getsockname(sock, &sa->sa, &slen);
   }
}

void mg_sock_to_str(sock_t sock, char *buf, size_t len, int flags) {
   union socket_address sa;
   mg_sock_get_addr(sock, flags & MG_SOCK_STRINGIFY_REMOTE, &sa);
   mg_sock_addr_to_str(&sa, buf, len, flags);
}
#endif

void mg_if_get_conn_addr(struct mg_connection *nc, int remote,
                         union socket_address *sa) {
#ifndef MG_SOCKET_SIMPLELINK
   mg_sock_get_addr(nc->sock, remote, sa);
#else
   /* SimpleLink does not provide a way to get socket's peer address after
    * accept or connect. Address hould have been preserved in the connection,
    * so we do our best here by using it. */
   if (remote) memcpy(sa, &nc->sa, sizeof(*sa));
#endif
}

#endif /* !MG_DISABLE_SOCKET_IF */
#ifdef MG_MODULE_LINES
#line 1 "./src/multithreading.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

/* Amalgamated: #include "mongoose/src/internal.h" */
/* Amalgamated: #include "mongoose/src/util.h" */

#ifdef MG_ENABLE_THREADS

static void multithreaded_ev_handler(struct mg_connection *c, int ev, void *p);

/*
 * This thread function executes user event handler.
 * It runs an event manager that has only one connection, until that
 * connection is alive.
 */
static void *per_connection_thread_function(void *param) {
   struct mg_connection *c = (struct mg_connection *) param;
   struct mg_mgr m;
   
   mg_mgr_init(&m, NULL);
   mg_add_conn(&m, c);
   while (m.active_connections != NULL) {
      mg_mgr_poll(&m, 1000);
   }
   mg_mgr_free(&m);
   
   return param;
}

static void link_conns(struct mg_connection *c1, struct mg_connection *c2) {
   c1->priv_2 = c2;
   c2->priv_2 = c1;
}

static void unlink_conns(struct mg_connection *c) {
   struct mg_connection *peer = (struct mg_connection *) c->priv_2;
   if (peer != NULL) {
      peer->flags |= MG_F_SEND_AND_CLOSE;
      peer->priv_2 = NULL;
   }
   c->priv_2 = NULL;
}

static void forwarder_ev_handler(struct mg_connection *c, int ev, void *p) {
   (void) p;
   if (ev == MG_EV_RECV && c->priv_2) {
      mg_forward(c, (struct mg_connection *) c->priv_2);
   } else if (ev == MG_EV_CLOSE) {
      unlink_conns(c);
   }
}

static void spawn_handling_thread(struct mg_connection *nc) {
   struct mg_mgr dummy;
   sock_t sp[2];
   struct mg_connection *c[2];
   
   /*
    * Create a socket pair, and wrap each socket into the connection with
    * dummy event manager.
    * c[0] stays in this thread, c[1] goes to another thread.
    */
   mg_socketpair(sp, SOCK_STREAM);
   memset(&dummy, 0, sizeof(dummy));
   c[0] = mg_add_sock(&dummy, sp[0], forwarder_ev_handler);
   c[1] = mg_add_sock(&dummy, sp[1], nc->listener->priv_1.f);
   
   /* Interlink client connection with c[0] */
   link_conns(c[0], nc);
   
   /*
    * Switch c[0] manager from the dummy one to the real one. c[1] manager
    * will be set in another thread, allocated on stack of that thread.
    */
   mg_add_conn(nc->mgr, c[0]);
   
   /*
    * Dress c[1] as nc.
    * TODO(lsm): code in accept_conn() looks similar. Refactor.
    */
   c[1]->listener = nc->listener;
   c[1]->proto_handler = nc->proto_handler;
   c[1]->proto_data = nc->proto_data;
   c[1]->user_data = nc->user_data;
   
   mg_start_thread(per_connection_thread_function, c[1]);
}

static void multithreaded_ev_handler(struct mg_connection *c, int ev, void *p) {
   (void) p;
   if (ev == MG_EV_ACCEPT) {
      spawn_handling_thread(c);
      c->handler = forwarder_ev_handler;
   }
}

void mg_enable_multithreading(struct mg_connection *nc) {
   /* Wrap user event handler into our multithreaded_ev_handler */
   nc->priv_1.f = nc->handler;
   nc->handler = multithreaded_ev_handler;
}
#endif
#ifdef MG_MODULE_LINES
#line 1 "./src/uri.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

/* Amalgamated: #include "mongoose/src/internal.h" */
/* Amalgamated: #include "mongoose/src/uri.h" */

/*
 * scan string until `sep`, keeping track of component boundaries in `res`.
 *
 * `p` will point to the char after the separator or it will be `end`.
 */
static void parse_uri_component(const char **p, const char *end, char sep,
                                struct mg_str *res) {
   res->p = *p;
   for (; *p < end; (*p)++) {
      if (**p == sep) {
         break;
      }
   }
   res->len = (*p) - res->p;
   if (*p < end) (*p)++;
}

int mg_parse_uri(struct mg_str uri, struct mg_str *scheme,
                 struct mg_str *user_info, struct mg_str *host,
                 unsigned int *port, struct mg_str *path, struct mg_str *query,
                 struct mg_str *fragment) {
   struct mg_str rscheme = {0, 0}, ruser_info = {0, 0}, rhost = {0, 0},
   rpath = {0, 0}, rquery = {0, 0}, rfragment = {0, 0};
   unsigned int rport = 0;
   enum {
      P_START,
      P_SCHEME_OR_PORT,
      P_USER_INFO,
      P_HOST,
      P_PORT,
      P_REST
   } state = P_START;
   
   const char *p = uri.p, *end = p + uri.len;
   while (p < end) {
      switch (state) {
         case P_START:
            /*
             * expecting on of:
             * - `scheme://xxxx`
             * - `xxxx:port`
             * - `xxxx/path`
             */
            for (; p < end; p++) {
               if (*p == ':') {
                  state = P_SCHEME_OR_PORT;
                  break;
               } else if (*p == '/') {
                  state = P_REST;
                  break;
               }
            }
            if (state == P_START || state == P_REST) {
               rhost.p = uri.p;
               rhost.len = p - uri.p;
            }
            break;
         case P_SCHEME_OR_PORT:
            if (end - p >= 3 && memcmp(p, "://", 3) == 0) {
               rscheme.p = uri.p;
               rscheme.len = p - uri.p;
               state = P_USER_INFO;
               p += 2; /* point to last separator char */
            } else {
               rhost.p = uri.p;
               rhost.len = p - uri.p;
               state = P_PORT;
            }
            break;
         case P_USER_INFO:
            p++;
            ruser_info.p = p;
            for (; p < end; p++) {
               if (*p == '@') {
                  state = P_HOST;
                  break;
               } else if (*p == '/') {
                  break;
               }
            }
            if (p == end || *p == '/') {
               /* backtrack and parse as host */
               state = P_HOST;
               p = ruser_info.p;
            }
            ruser_info.len = p - ruser_info.p;
            break;
         case P_HOST:
            if (*p == '@') p++;
            rhost.p = p;
            for (; p < end; p++) {
               if (*p == ':') {
                  state = P_PORT;
                  break;
               } else if (*p == '/') {
                  state = P_REST;
                  break;
               }
            }
            rhost.len = p - rhost.p;
            break;
         case P_PORT:
            p++;
            for (; p < end; p++) {
               if (*p == '/') {
                  state = P_REST;
                  break;
               }
               rport *= 10;
               rport += *p - '0';
            }
            break;
         case P_REST:
            /* `p` points to separator. `path` includes the separator */
            parse_uri_component(&p, end, '?', &rpath);
            parse_uri_component(&p, end, '#', &rquery);
            parse_uri_component(&p, end, '\0', &rfragment);
            break;
      }
   }
   
   if (scheme != 0) *scheme = rscheme;
   if (user_info != 0) *user_info = ruser_info;
   if (host != 0) *host = rhost;
   if (port != 0) *port = rport;
   if (path != 0) *path = rpath;
   if (query != 0) *query = rquery;
   if (fragment != 0) *fragment = rfragment;
   
   return 0;
}

/* Normalize the URI path. Remove/resolve "." and "..". */
int mg_normalize_uri_path(const struct mg_str *in, struct mg_str *out) {
   const char *s = in->p, *se = s + in->len;
   char *cp = (char *) out->p, *d;
   
   if (in->len == 0 || *s != '/') {
      out->len = 0;
      return 0;
   }
   
   d = cp;
   
   while (s < se) {
      const char *next = s;
      struct mg_str component;
      parse_uri_component(&next, se, '/', &component);
      if (mg_vcmp(&component, ".") == 0) {
         /* Yum. */
      } else if (mg_vcmp(&component, "..") == 0) {
         /* Backtrack to previous slash. */
         if (d > cp + 1 && *(d - 1) == '/') d--;
         while (d > cp && *(d - 1) != '/') d--;
      } else {
         memmove(d, s, next - s);
         d += next - s;
      }
      s = next;
   }
   if (d == cp) *d++ = '/';
   
   out->p = cp;
   out->len = d - cp;
   return 1;
}
#ifdef MG_MODULE_LINES
#line 1 "./src/http.c"
#endif
/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#ifndef MG_DISABLE_HTTP

/* Amalgamated: #include "mongoose/src/internal.h" */
/* Amalgamated: #include "mongoose/src/util.h" */
/* Amalgamated: #include "common/sha1.h" */
/* Amalgamated: #include "common/md5.h" */

#ifndef MG_DISABLE_HTTP_WEBSOCKET
#define MG_WS_NO_HOST_HEADER_MAGIC ((char *) 0x1)
#endif

/* CGI requires socketpair. */
#if defined(MG_DISABLE_SOCKETPAIR) && !defined(MG_DISABLE_CGI)
#define MG_DISABLE_CGI 1
#endif

static const char *mg_version_header = "Mongoose/" MG_VERSION;

enum mg_http_proto_data_type { DATA_NONE, DATA_FILE, DATA_PUT };

struct mg_http_proto_data_file {
   FILE *fp;      /* Opened file. */
   int64_t cl;    /* Content-Length. How many bytes to send. */
   int64_t sent;  /* How many bytes have been already sent. */
   int keepalive; /* Keep connection open after sending. */
   enum mg_http_proto_data_type type;
};

struct mg_http_proto_data_cgi {
   struct mg_connection *cgi_nc;
};

struct mg_http_proto_data_chuncked {
   int64_t body_len; /* How many bytes of chunked body was reassembled. */
};

struct mg_http_endpoint {
   struct mg_http_endpoint *next;
   const char *name;
   size_t name_len;
   mg_event_handler_t handler;
};

enum mg_http_multipart_stream_state {
   MPS_BEGIN,
   MPS_WAITING_FOR_BOUNDARY,
   MPS_WAITING_FOR_CHUNK,
   MPS_GOT_CHUNK,
   MPS_GOT_BOUNDARY,
   MPS_FINALIZE,
   MPS_FINISHED
};

struct mg_http_multipart_stream {
   const char *boundary;
   int boundary_len;
   const char *var_name;
   const char *file_name;
   void *user_data;
   int prev_io_len;
   enum mg_http_multipart_stream_state state;
   int processing_part;
};

struct mg_http_proto_data {
#ifndef MG_DISABLE_FILESYSTEM
   struct mg_http_proto_data_file file;
#endif
#ifndef MG_DISABLE_CGI
   struct mg_http_proto_data_cgi cgi;
#endif
#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
   struct mg_http_multipart_stream mp_stream;
#endif
   struct mg_http_proto_data_chuncked chunk;
   struct mg_http_endpoint *endpoints;
   mg_event_handler_t endpoint_handler;
};

static void mg_http_conn_destructor(void *proto_data);

static struct mg_http_proto_data *mg_http_get_proto_data(
                                                         struct mg_connection *c) {
   if (c->proto_data == NULL) {
      c->proto_data = MG_CALLOC(1, sizeof(struct mg_http_proto_data));
      c->proto_data_destructor = mg_http_conn_destructor;
   }
   
   return (struct mg_http_proto_data *) c->proto_data;
}

#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
static void mg_http_free_proto_data_mp_stream(
                                              struct mg_http_multipart_stream *mp) {
   free((void *) mp->boundary);
   mp->boundary = NULL;
   free((void *) mp->var_name);
   mp->var_name = NULL;
   free((void *) mp->file_name);
   mp->file_name = NULL;
}
#endif

#ifndef MG_DISABLE_FILESYSTEM
static void mg_http_free_proto_data_file(struct mg_http_proto_data_file *d) {
   if (d != NULL) {
      if (d->fp != NULL) {
         fclose(d->fp);
      }
      memset(d, 0, sizeof(struct mg_http_proto_data_file));
   }
}
#endif

#ifndef MG_DISABLE_CGI
static void mg_http_free_proto_data_cgi(struct mg_http_proto_data_cgi *d) {
   if (d != NULL) {
      if (d->cgi_nc != NULL) d->cgi_nc->flags |= MG_F_CLOSE_IMMEDIATELY;
      memset(d, 0, sizeof(struct mg_http_proto_data_cgi));
   }
}
#endif

static void mg_http_free_proto_data_endpoints(struct mg_http_endpoint **ep) {
   struct mg_http_endpoint *current = *ep;
   
   while (current != NULL) {
      struct mg_http_endpoint *tmp = current->next;
      free((void *) current->name);
      free(current);
      current = tmp;
   }
   
   ep = NULL;
}

static void mg_http_conn_destructor(void *proto_data) {
   struct mg_http_proto_data *pd = (struct mg_http_proto_data *) proto_data;
#ifndef MG_DISABLE_FILESYSTEM
   mg_http_free_proto_data_file(&pd->file);
#endif
#ifndef MG_DISABLE_CGI
   mg_http_free_proto_data_cgi(&pd->cgi);
#endif
#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
   mg_http_free_proto_data_mp_stream(&pd->mp_stream);
#endif
   mg_http_free_proto_data_endpoints(&pd->endpoints);
   free(proto_data);
}

/*
 * This structure helps to create an environment for the spawned CGI program.
 * Environment is an array of "VARIABLE=VALUE\0" ASCIIZ strings,
 * last element must be NULL.
 * However, on Windows there is a requirement that all these VARIABLE=VALUE\0
 * strings must reside in a contiguous buffer. The end of the buffer is
 * marked by two '\0' characters.
 * We satisfy both worlds: we create an envp array (which is vars), all
 * entries are actually pointers inside buf.
 */
struct mg_cgi_env_block {
   struct mg_connection *nc;
   char buf[MG_CGI_ENVIRONMENT_SIZE];       /* Environment buffer */
   const char *vars[MG_MAX_CGI_ENVIR_VARS]; /* char *envp[] */
   int len;                                 /* Space taken */
   int nvars;                               /* Number of variables in envp[] */
};

#ifndef MG_DISABLE_FILESYSTEM

#define MIME_ENTRY(_ext, _type) \
{ _ext, sizeof(_ext) - 1, _type }
static const struct {
   const char *extension;
   size_t ext_len;
   const char *mime_type;
} mg_static_builtin_mime_types[] = {
   MIME_ENTRY("html", "text/html"),
   MIME_ENTRY("html", "text/html"),
   MIME_ENTRY("htm", "text/html"),
   MIME_ENTRY("shtm", "text/html"),
   MIME_ENTRY("shtml", "text/html"),
   MIME_ENTRY("css", "text/css"),
   MIME_ENTRY("js", "application/x-javascript"),
   MIME_ENTRY("ico", "image/x-icon"),
   MIME_ENTRY("gif", "image/gif"),
   MIME_ENTRY("jpg", "image/jpeg"),
   MIME_ENTRY("jpeg", "image/jpeg"),
   MIME_ENTRY("png", "image/png"),
   MIME_ENTRY("svg", "image/svg+xml"),
   MIME_ENTRY("txt", "text/plain"),
   MIME_ENTRY("torrent", "application/x-bittorrent"),
   MIME_ENTRY("wav", "audio/x-wav"),
   MIME_ENTRY("mp3", "audio/x-mp3"),
   MIME_ENTRY("mid", "audio/mid"),
   MIME_ENTRY("m3u", "audio/x-mpegurl"),
   MIME_ENTRY("ogg", "application/ogg"),
   MIME_ENTRY("ram", "audio/x-pn-realaudio"),
   MIME_ENTRY("xml", "text/xml"),
   MIME_ENTRY("ttf", "application/x-font-ttf"),
   MIME_ENTRY("json", "application/json"),
   MIME_ENTRY("xslt", "application/xml"),
   MIME_ENTRY("xsl", "application/xml"),
   MIME_ENTRY("ra", "audio/x-pn-realaudio"),
   MIME_ENTRY("doc", "application/msword"),
   MIME_ENTRY("exe", "application/octet-stream"),
   MIME_ENTRY("zip", "application/x-zip-compressed"),
   MIME_ENTRY("xls", "application/excel"),
   MIME_ENTRY("tgz", "application/x-tar-gz"),
   MIME_ENTRY("tar", "application/x-tar"),
   MIME_ENTRY("gz", "application/x-gunzip"),
   MIME_ENTRY("arj", "application/x-arj-compressed"),
   MIME_ENTRY("rar", "application/x-rar-compressed"),
   MIME_ENTRY("rtf", "application/rtf"),
   MIME_ENTRY("pdf", "application/pdf"),
   MIME_ENTRY("swf", "application/x-shockwave-flash"),
   MIME_ENTRY("mpg", "video/mpeg"),
   MIME_ENTRY("webm", "video/webm"),
   MIME_ENTRY("mpeg", "video/mpeg"),
   MIME_ENTRY("mov", "video/quicktime"),
   MIME_ENTRY("mp4", "video/mp4"),
   MIME_ENTRY("m4v", "video/x-m4v"),
   MIME_ENTRY("asf", "video/x-ms-asf"),
   MIME_ENTRY("avi", "video/x-msvideo"),
   MIME_ENTRY("bmp", "image/bmp"),
   {NULL, 0, NULL}};

#ifndef MG_DISABLE_DAV
static int mg_mkdir(const char *path, uint32_t mode) {
#ifndef _WIN32
   return mkdir(path, mode);
#else
   (void) mode;
   return _mkdir(path);
#endif
}
#endif

static struct mg_str mg_get_mime_type(const char *path, const char *dflt,
                                      const struct mg_serve_http_opts *opts) {
   const char *ext, *overrides;
   size_t i, path_len;
   struct mg_str r, k, v;
   
   path_len = strlen(path);
   
   overrides = opts->custom_mime_types;
   while ((overrides = mg_next_comma_list_entry(overrides, &k, &v)) != NULL) {
      ext = path + (path_len - k.len);
      if (path_len > k.len && mg_vcasecmp(&k, ext) == 0) {
         return v;
      }
   }
   
   for (i = 0; mg_static_builtin_mime_types[i].extension != NULL; i++) {
      ext = path + (path_len - mg_static_builtin_mime_types[i].ext_len);
      if (path_len > mg_static_builtin_mime_types[i].ext_len && ext[-1] == '.' &&
          mg_casecmp(ext, mg_static_builtin_mime_types[i].extension) == 0) {
         r.p = mg_static_builtin_mime_types[i].mime_type;
         r.len = strlen(r.p);
         return r;
      }
   }
   
   r.p = dflt;
   r.len = strlen(r.p);
   return r;
}
#endif

/*
 * Check whether full request is buffered. Return:
 *   -1  if request is malformed
 *    0  if request is not yet fully buffered
 *   >0  actual request length, including last \r\n\r\n
 */
static int mg_http_get_request_len(const char *s, int buf_len) {
   const unsigned char *buf = (unsigned char *) s;
   int i;
   
   for (i = 0; i < buf_len; i++) {
      if (!isprint(buf[i]) && buf[i] != '\r' && buf[i] != '\n' && buf[i] < 128) {
         return -1;
      } else if (buf[i] == '\n' && i + 1 < buf_len && buf[i + 1] == '\n') {
         return i + 2;
      } else if (buf[i] == '\n' && i + 2 < buf_len && buf[i + 1] == '\r' &&
                 buf[i + 2] == '\n') {
         return i + 3;
      }
   }
   
   return 0;
}

static const char *mg_http_parse_headers(const char *s, const char *end,
                                         int len, struct http_message *req) {
   int i;
   for (i = 0; i < (int) ARRAY_SIZE(req->header_names) - 1; i++) {
      struct mg_str *k = &req->header_names[i], *v = &req->header_values[i];
      
      s = mg_skip(s, end, ": ", k);
      s = mg_skip(s, end, "\r\n", v);
      
      while (v->len > 0 && v->p[v->len - 1] == ' ') {
         v->len--; /* Trim trailing spaces in header value */
      }
      
      if (k->len == 0 || v->len == 0) {
         k->p = v->p = NULL;
         k->len = v->len = 0;
         break;
      }
      
      if (!mg_ncasecmp(k->p, "Content-Length", 14)) {
         req->body.len = to64(v->p);
         req->message.len = len + req->body.len;
      }
   }
   
   return s;
}

int mg_parse_http(const char *s, int n, struct http_message *hm, int is_req) {
   const char *end, *qs;
   int len = mg_http_get_request_len(s, n);
   
   if (len <= 0) return len;
   
   memset(hm, 0, sizeof(*hm));
   hm->message.p = s;
   hm->body.p = s + len;
   hm->message.len = hm->body.len = (size_t) ~0;
   end = s + len;
   
   /* Request is fully buffered. Skip leading whitespaces. */
   while (s < end && isspace(*(unsigned char *) s)) s++;
   
   if (is_req) {
      /* Parse request line: method, URI, proto */
      s = mg_skip(s, end, " ", &hm->method);
      s = mg_skip(s, end, " ", &hm->uri);
      s = mg_skip(s, end, "\r\n", &hm->proto);
      if (hm->uri.p <= hm->method.p || hm->proto.p <= hm->uri.p) return -1;
      
      /* If URI contains '?' character, initialize query_string */
      if ((qs = (char *) memchr(hm->uri.p, '?', hm->uri.len)) != NULL) {
         hm->query_string.p = qs + 1;
         hm->query_string.len = &hm->uri.p[hm->uri.len] - (qs + 1);
         hm->uri.len = qs - hm->uri.p;
      }
   } else {
      s = mg_skip(s, end, " ", &hm->proto);
      if (end - s < 4 || s[3] != ' ') return -1;
      hm->resp_code = atoi(s);
      if (hm->resp_code < 100 || hm->resp_code >= 600) return -1;
      s += 4;
      s = mg_skip(s, end, "\r\n", &hm->resp_status_msg);
   }
   
   s = mg_http_parse_headers(s, end, len, hm);
   
   /*
    * mg_parse_http() is used to parse both HTTP requests and HTTP
    * responses. If HTTP response does not have Content-Length set, then
    * body is read until socket is closed, i.e. body.len is infinite (~0).
    *
    * For HTTP requests though, according to
    * http://tools.ietf.org/html/rfc7231#section-8.1.3,
    * only POST and PUT methods have defined body semantics.
    * Therefore, if Content-Length is not specified and methods are
    * not one of PUT or POST, set body length to 0.
    *
    * So,
    * if it is HTTP request, and Content-Length is not set,
    * and method is not (PUT or POST) then reset body length to zero.
    */
   if (hm->body.len == (size_t) ~0 && is_req &&
       mg_vcasecmp(&hm->method, "PUT") != 0 &&
       mg_vcasecmp(&hm->method, "POST") != 0) {
      hm->body.len = 0;
      hm->message.len = len;
   }
   
   return len;
}

struct mg_str *mg_get_http_header(struct http_message *hm, const char *name) {
   size_t i, len = strlen(name);
   
   for (i = 0; hm->header_names[i].len > 0; i++) {
      struct mg_str *h = &hm->header_names[i], *v = &hm->header_values[i];
      if (h->p != NULL && h->len == len && !mg_ncasecmp(h->p, name, len))
         return v;
   }
   
   return NULL;
}

#ifndef MG_DISABLE_HTTP_WEBSOCKET

static int mg_is_ws_fragment(unsigned char flags) {
   return (flags & 0x80) == 0 || (flags & 0x0f) == 0;
}

static int mg_is_ws_first_fragment(unsigned char flags) {
   return (flags & 0x80) == 0 && (flags & 0x0f) != 0;
}

static void mg_handle_incoming_websocket_frame(struct mg_connection *nc,
                                               struct websocket_message *wsm) {
   if (wsm->flags & 0x8) {
      mg_call(nc, nc->handler, MG_EV_WEBSOCKET_CONTROL_FRAME, wsm);
   } else {
      mg_call(nc, nc->handler, MG_EV_WEBSOCKET_FRAME, wsm);
   }
}

static int mg_deliver_websocket_data(struct mg_connection *nc) {
   /* Using unsigned char *, cause of integer arithmetic below */
   uint64_t i, data_len = 0, frame_len = 0, buf_len = nc->recv_mbuf.len, len,
   mask_len = 0, header_len = 0;
   unsigned char *p = (unsigned char *) nc->recv_mbuf.buf, *buf = p,
   *e = p + buf_len;
   unsigned *sizep = (unsigned *) &p[1]; /* Size ptr for defragmented frames */
   int ok, reass = buf_len > 0 && mg_is_ws_fragment(p[0]) &&
   !(nc->flags & MG_F_WEBSOCKET_NO_DEFRAG);
   
   /* If that's a continuation frame that must be reassembled, handle it */
   if (reass && !mg_is_ws_first_fragment(p[0]) &&
       buf_len >= 1 + sizeof(*sizep) && buf_len >= 1 + sizeof(*sizep) + *sizep) {
      buf += 1 + sizeof(*sizep) + *sizep;
      buf_len -= 1 + sizeof(*sizep) + *sizep;
   }
   
   if (buf_len >= 2) {
      len = buf[1] & 127;
      mask_len = buf[1] & 128 ? 4 : 0;
      if (len < 126 && buf_len >= mask_len) {
         data_len = len;
         header_len = 2 + mask_len;
      } else if (len == 126 && buf_len >= 4 + mask_len) {
         header_len = 4 + mask_len;
         data_len = ntohs(*(uint16_t *) &buf[2]);
      } else if (buf_len >= 10 + mask_len) {
         header_len = 10 + mask_len;
         data_len = (((uint64_t) ntohl(*(uint32_t *) &buf[2])) << 32) +
         ntohl(*(uint32_t *) &buf[6]);
      }
   }
   
   frame_len = header_len + data_len;
   ok = frame_len > 0 && frame_len <= buf_len;
   
   if (ok) {
      struct websocket_message wsm;
      
      wsm.size = (size_t) data_len;
      wsm.data = buf + header_len;
      wsm.flags = buf[0];
      
      /* Apply mask if necessary */
      if (mask_len > 0) {
         for (i = 0; i < data_len; i++) {
            buf[i + header_len] ^= (buf + header_len - mask_len)[i % 4];
         }
      }
      
      if (reass) {
         /* On first fragmented frame, nullify size */
         if (mg_is_ws_first_fragment(wsm.flags)) {
            mbuf_resize(&nc->recv_mbuf, nc->recv_mbuf.size + sizeof(*sizep));
            p[0] &= ~0x0f; /* Next frames will be treated as continuation */
            buf = p + 1 + sizeof(*sizep);
            *sizep = 0; /* TODO(lsm): fix. this can stomp over frame data */
         }
         
         /* Append this frame to the reassembled buffer */
         memmove(buf, wsm.data, e - wsm.data);
         (*sizep) += wsm.size;
         nc->recv_mbuf.len -= wsm.data - buf;
         
         /* On last fragmented frame - call user handler and remove data */
         if (wsm.flags & 0x80) {
            wsm.data = p + 1 + sizeof(*sizep);
            wsm.size = *sizep;
            mg_handle_incoming_websocket_frame(nc, &wsm);
            mbuf_remove(&nc->recv_mbuf, 1 + sizeof(*sizep) + *sizep);
         }
      } else {
         /* TODO(lsm): properly handle OOB control frames during defragmentation */
         mg_handle_incoming_websocket_frame(nc, &wsm);
         mbuf_remove(&nc->recv_mbuf, (size_t) frame_len); /* Cleanup frame */
      }
      
      /* If client closes, close too */
      if ((buf[0] & 0x0f) == WEBSOCKET_OP_CLOSE) {
         nc->flags |= MG_F_SEND_AND_CLOSE;
      }
   }
   
   return ok;
}

struct ws_mask_ctx {
   size_t pos; /* zero means unmasked */
   uint32_t mask;
};

static uint32_t mg_ws_random_mask(void) {
   uint32_t mask;
   /*
    * The spec requires WS client to generate hard to
    * guess mask keys. From RFC6455, Section 5.3:
    *
    * The unpredictability of the masking key is essential to prevent
    * authors of malicious applications from selecting the bytes that appear on
    * the wire.
    *
    * Hence this feature is essential when the actual end user of this API
    * is untrusted code that wouldn't have access to a lower level net API
    * anyway (e.g. web browsers). Hence this feature is low prio for most
    * mongoose use cases and thus can be disabled, e.g. when porting to a platform
    * that lacks random().
    */
#ifdef MG_DISABLE_WS_RANDOM_MASK
   mask = 0xefbeadde; /* generated with a random number generator, I swear */
#else
   if (sizeof(long) >= 4) {
      mask = (uint32_t) random();
   } else if (sizeof(long) == 2) {
      mask = (uint32_t) random() << 16 | (uint32_t) random();
   }
#endif
   return mask;
}

static void mg_send_ws_header(struct mg_connection *nc, int op, size_t len,
                              struct ws_mask_ctx *ctx) {
   int header_len;
   unsigned char header[10];
   
   header[0] = (op & WEBSOCKET_DONT_FIN ? 0x0 : 0x80) + (op & 0x0f);
   if (len < 126) {
      header[1] = len;
      header_len = 2;
   } else if (len < 65535) {
      uint16_t tmp = htons((uint16_t) len);
      header[1] = 126;
      memcpy(&header[2], &tmp, sizeof(tmp));
      header_len = 4;
   } else {
      uint32_t tmp;
      header[1] = 127;
      tmp = htonl((uint32_t)((uint64_t) len >> 32));
      memcpy(&header[2], &tmp, sizeof(tmp));
      tmp = htonl((uint32_t)(len & 0xffffffff));
      memcpy(&header[6], &tmp, sizeof(tmp));
      header_len = 10;
   }
   
   /* client connections enable masking */
   if (nc->listener == NULL) {
      header[1] |= 1 << 7; /* set masking flag */
      mg_send(nc, header, header_len);
      ctx->mask = mg_ws_random_mask();
      mg_send(nc, &ctx->mask, sizeof(ctx->mask));
      ctx->pos = nc->send_mbuf.len;
   } else {
      mg_send(nc, header, header_len);
      ctx->pos = 0;
   }
}

static void mg_ws_mask_frame(struct mbuf *mbuf, struct ws_mask_ctx *ctx) {
   size_t i;
   if (ctx->pos == 0) return;
   for (i = 0; i < (mbuf->len - ctx->pos); i++) {
      mbuf->buf[ctx->pos + i] ^= ((char *) &ctx->mask)[i % 4];
   }
}

void mg_send_websocket_frame(struct mg_connection *nc, int op, const void *data,
                             size_t len) {
   struct ws_mask_ctx ctx;
   DBG(("%p %d %d", nc, op, (int) len));
   mg_send_ws_header(nc, op, len, &ctx);
   mg_send(nc, data, len);
   
   mg_ws_mask_frame(&nc->send_mbuf, &ctx);
   
   if (op == WEBSOCKET_OP_CLOSE) {
      nc->flags |= MG_F_SEND_AND_CLOSE;
   }
}

void mg_send_websocket_framev(struct mg_connection *nc, int op,
                              const struct mg_str *strv, int strvcnt) {
   struct ws_mask_ctx ctx;
   int i;
   int len = 0;
   for (i = 0; i < strvcnt; i++) {
      len += strv[i].len;
   }
   
   mg_send_ws_header(nc, op, len, &ctx);
   
   for (i = 0; i < strvcnt; i++) {
      mg_send(nc, strv[i].p, strv[i].len);
   }
   
   mg_ws_mask_frame(&nc->send_mbuf, &ctx);
   
   if (op == WEBSOCKET_OP_CLOSE) {
      nc->flags |= MG_F_SEND_AND_CLOSE;
   }
}

void mg_printf_websocket_frame(struct mg_connection *nc, int op,
                               const char *fmt, ...) {
   char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
   va_list ap;
   int len;
   
   va_start(ap, fmt);
   if ((len = mg_avprintf(&buf, sizeof(mem), fmt, ap)) > 0) {
      mg_send_websocket_frame(nc, op, buf, len);
   }
   va_end(ap);
   
   if (buf != mem && buf != NULL) {
      MG_FREE(buf);
   }
}

static void mg_websocket_handler(struct mg_connection *nc, int ev,
                                 void *ev_data) {
   mg_call(nc, nc->handler, ev, ev_data);
   
   switch (ev) {
      case MG_EV_RECV:
         do {
         } while (mg_deliver_websocket_data(nc));
         break;
      case MG_EV_POLL:
         /* Ping idle websocket connections */
      {
      time_t now = *(time_t *) ev_data;
      if (nc->flags & MG_F_IS_WEBSOCKET &&
          now > nc->last_io_time + MG_WEBSOCKET_PING_INTERVAL_SECONDS) {
         mg_send_websocket_frame(nc, WEBSOCKET_OP_PING, "", 0);
      }
      }
         break;
      default:
         break;
   }
}

static void mg_ws_handshake(struct mg_connection *nc,
                            const struct mg_str *key) {
   static const char *magic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
   char buf[MG_VPRINTF_BUFFER_SIZE], sha[20], b64_sha[sizeof(sha) * 2];
   cs_sha1_ctx sha_ctx;
   
   snprintf(buf, sizeof(buf), "%.*s%s", (int) key->len, key->p, magic);
   
   cs_sha1_init(&sha_ctx);
   cs_sha1_update(&sha_ctx, (unsigned char *) buf, strlen(buf));
   cs_sha1_final((unsigned char *) sha, &sha_ctx);
   
   mg_base64_encode((unsigned char *) sha, sizeof(sha), b64_sha);
   mg_printf(nc, "%s%s%s",
             "HTTP/1.1 101 Switching Protocols\r\n"
             "Upgrade: websocket\r\n"
             "Connection: Upgrade\r\n"
             "Sec-WebSocket-Accept: ",
             b64_sha, "\r\n\r\n");
   DBG(("%p %.*s %s", nc, (int) key->len, key->p, b64_sha));
}

#endif /* MG_DISABLE_HTTP_WEBSOCKET */

#ifndef MG_DISABLE_FILESYSTEM
static void mg_http_transfer_file_data(struct mg_connection *nc) {
   struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
   char buf[MG_MAX_HTTP_SEND_MBUF];
   int64_t left = pd->file.cl - pd->file.sent;
   size_t n = 0, to_read = 0;
   
   if (pd->file.type == DATA_FILE) {
      struct mbuf *io = &nc->send_mbuf;
      if (io->len < sizeof(buf)) {
         to_read = sizeof(buf) - io->len;
      }
      
      if (left > 0 && to_read > (size_t) left) {
         to_read = left;
      }
      
      if (to_read == 0) {
         /* Rate limiting. send_mbuf is too full, wait until it's drained. */
      } else if (pd->file.sent < pd->file.cl &&
                 (n = fread(buf, 1, to_read, pd->file.fp)) > 0) {
         mg_send(nc, buf, n);
         pd->file.sent += n;
      } else {
         if (!pd->file.keepalive) nc->flags |= MG_F_SEND_AND_CLOSE;
         mg_http_free_proto_data_file(&pd->file);
      }
   } else if (pd->file.type == DATA_PUT) {
      struct mbuf *io = &nc->recv_mbuf;
      size_t to_write =
      left <= 0 ? 0 : left < (int64_t) io->len ? (size_t) left : io->len;
      size_t n = fwrite(io->buf, 1, to_write, pd->file.fp);
      if (n > 0) {
         mbuf_remove(io, n);
         pd->file.sent += n;
      }
      if (n == 0 || pd->file.sent >= pd->file.cl) {
         if (!pd->file.keepalive) nc->flags |= MG_F_SEND_AND_CLOSE;
         mg_http_free_proto_data_file(&pd->file);
      }
   }
#ifndef MG_DISABLE_CGI
   else if (pd->cgi.cgi_nc != NULL) {
      /* This is POST data that needs to be forwarded to the CGI process */
      if (pd->cgi.cgi_nc != NULL) {
         mg_forward(nc, pd->cgi.cgi_nc);
      } else {
         nc->flags |= MG_F_SEND_AND_CLOSE;
      }
   }
#endif
}
#endif /* MG_DISABLE_FILESYSTEM */

/*
 * Parse chunked-encoded buffer. Return 0 if the buffer is not encoded, or
 * if it's incomplete. If the chunk is fully buffered, return total number of
 * bytes in a chunk, and store data in `data`, `data_len`.
 */
static size_t mg_http_parse_chunk(char *buf, size_t len, char **chunk_data,
                                  size_t *chunk_len) {
   unsigned char *s = (unsigned char *) buf;
   size_t n = 0; /* scanned chunk length */
   size_t i = 0; /* index in s */
   
   /* Scan chunk length. That should be a hexadecimal number. */
   while (i < len && isxdigit(s[i])) {
      n *= 16;
      n += (s[i] >= '0' && s[i] <= '9') ? s[i] - '0' : tolower(s[i]) - 'a' + 10;
      i++;
   }
   
   /* Skip new line */
   if (i == 0 || i + 2 > len || s[i] != '\r' || s[i + 1] != '\n') {
      return 0;
   }
   i += 2;
   
   /* Record where the data is */
   *chunk_data = (char *) s + i;
   *chunk_len = n;
   
   /* Skip data */
   i += n;
   
   /* Skip new line */
   if (i == 0 || i + 2 > len || s[i] != '\r' || s[i + 1] != '\n') {
      return 0;
   }
   return i + 2;
}

MG_INTERNAL size_t mg_handle_chunked(struct mg_connection *nc,
                                     struct http_message *hm, char *buf,
                                     size_t blen) {
   struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
   char *data;
   size_t i, n, data_len, body_len, zero_chunk_received = 0;
   
   /* Find out piece of received data that is not yet reassembled */
   body_len = pd->chunk.body_len;
   assert(blen >= body_len);
   
   /* Traverse all fully buffered chunks */
   for (i = body_len;
        (n = mg_http_parse_chunk(buf + i, blen - i, &data, &data_len)) > 0;
        i += n) {
      /* Collapse chunk data to the rest of HTTP body */
      memmove(buf + body_len, data, data_len);
      body_len += data_len;
      hm->body.len = body_len;
      
      if (data_len == 0) {
         zero_chunk_received = 1;
         i += n;
         break;
      }
   }
   
   if (i > body_len) {
      /* Shift unparsed content to the parsed body */
      assert(i <= blen);
      memmove(buf + body_len, buf + i, blen - i);
      memset(buf + body_len + blen - i, 0, i - body_len);
      nc->recv_mbuf.len -= i - body_len;
      pd->chunk.body_len = body_len;
      
      /* Send MG_EV_HTTP_CHUNK event */
      nc->flags &= ~MG_F_DELETE_CHUNK;
      mg_call(nc, nc->handler, MG_EV_HTTP_CHUNK, hm);
      
      /* Delete processed data if user set MG_F_DELETE_CHUNK flag */
      if (nc->flags & MG_F_DELETE_CHUNK) {
         memset(buf, 0, body_len);
         memmove(buf, buf + body_len, blen - i);
         nc->recv_mbuf.len -= body_len;
         hm->body.len = pd->chunk.body_len = 0;
      }
      
      if (zero_chunk_received) {
         hm->message.len = pd->chunk.body_len + blen - i;
      }
   }
   
   return body_len;
}

static mg_event_handler_t mg_http_get_endpoint_handler(
                                                       struct mg_connection *nc, struct mg_str *uri_path) {
   struct mg_http_proto_data *pd;
   mg_event_handler_t ret = NULL;
   int matched, matched_max = 0;
   struct mg_http_endpoint *ep;
   
   if (nc == NULL) {
      return NULL;
   }
   
   pd = mg_http_get_proto_data(nc);
   
   ep = pd->endpoints;
   while (ep != NULL) {
      const struct mg_str name_s = {ep->name, ep->name_len};
      if ((matched = mg_match_prefix_n(name_s, *uri_path)) != -1) {
         if (matched > matched_max) {
            /* Looking for the longest suitable handler */
            ret = ep->handler;
            matched_max = matched;
         }
      }
      
      ep = ep->next;
   }
   
   return ret;
}

static void mg_http_call_endpoint_handler(struct mg_connection *nc, int ev,
                                          struct http_message *hm) {
   struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
   
   if (pd->endpoint_handler == NULL || ev == MG_EV_HTTP_REQUEST) {
      pd->endpoint_handler =
      ev == MG_EV_HTTP_REQUEST
      ? mg_http_get_endpoint_handler(nc->listener, &hm->uri)
      : NULL;
   }
   mg_call(nc, pd->endpoint_handler ? pd->endpoint_handler : nc->handler, ev,
           hm);
}

#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
static void mg_http_multipart_continue(struct mg_connection *nc);

static void mg_http_multipart_begin(struct mg_connection *nc,
                                    struct http_message *hm, int req_len);

#endif

/*
 * lx106 compiler has a bug (TODO(mkm) report and insert tracking bug here)
 * If a big structure is declared in a big function, lx106 gcc will make it
 * even bigger (round up to 4k, from 700 bytes of actual size).
 */
#ifdef __xtensa__
static void mg_http_handler2(struct mg_connection *nc, int ev, void *ev_data,
                             struct http_message *hm) __attribute__((noinline));

void mg_http_handler(struct mg_connection *nc, int ev, void *ev_data) {
   struct http_message hm;
   mg_http_handler2(nc, ev, ev_data, &hm);
}

static void mg_http_handler2(struct mg_connection *nc, int ev, void *ev_data,
                             struct http_message *hm) {
#else  /* !__XTENSA__ */
   void mg_http_handler(struct mg_connection *nc, int ev, void *ev_data) {
      struct http_message shm;
      struct http_message *hm = &shm;
#endif /* __XTENSA__ */
      struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
      struct mbuf *io = &nc->recv_mbuf;
      int req_len;
      const int is_req = (nc->listener != NULL);
#ifndef MG_DISABLE_HTTP_WEBSOCKET
      struct mg_str *vec;
#endif
      if (ev == MG_EV_CLOSE) {
#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
         if (pd->mp_stream.boundary != NULL) {
            /*
             * Multipart message is in progress, but we get close
             * MG_EV_HTTP_PART_END with error flag
             */
            struct mg_http_multipart_part mp;
            memset(&mp, 0, sizeof(mp));
            
            mp.status = -1;
            mp.var_name = pd->mp_stream.var_name;
            mp.file_name = pd->mp_stream.file_name;
            mg_call(nc, (pd->endpoint_handler ? pd->endpoint_handler : nc->handler),
                    MG_EV_HTTP_PART_END, &mp);
         } else
#endif
            if (io->len > 0 && mg_parse_http(io->buf, io->len, hm, is_req) > 0) {
               /*
                * For HTTP messages without Content-Length, always send HTTP message
                * before MG_EV_CLOSE message.
                */
               int ev2 = is_req ? MG_EV_HTTP_REQUEST : MG_EV_HTTP_REPLY;
               hm->message.len = io->len;
               hm->body.len = io->buf + io->len - hm->body.p;
               mg_http_call_endpoint_handler(nc, ev2, hm);
            }
      }
      
#ifndef MG_DISABLE_FILESYSTEM
      if (pd->file.fp != NULL) {
         mg_http_transfer_file_data(nc);
      }
#endif
      
      mg_call(nc, nc->handler, ev, ev_data);
      
      if (ev == MG_EV_RECV) {
         struct mg_str *s;
         
#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
         if (pd->mp_stream.boundary != NULL) {
            mg_http_multipart_continue(nc);
            return;
         }
#endif /* MG_ENABLE_HTTP_STREAMING_MULTIPART */
         
         req_len = mg_parse_http(io->buf, io->len, hm, is_req);
         
         if (req_len > 0 &&
             (s = mg_get_http_header(hm, "Transfer-Encoding")) != NULL &&
             mg_vcasecmp(s, "chunked") == 0) {
            mg_handle_chunked(nc, hm, io->buf + req_len, io->len - req_len);
         }
         
#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
         if (req_len > 0 && (s = mg_get_http_header(hm, "Content-Type")) != NULL &&
             s->len >= 9 && strncmp(s->p, "multipart", 9) == 0) {
            mg_http_multipart_begin(nc, hm, req_len);
            mg_http_multipart_continue(nc);
            return;
         }
#endif /* MG_ENABLE_HTTP_STREAMING_MULTIPART */
         
         /* TODO(alashkin): refactor this ifelseifelseifelseifelse */
         if ((req_len < 0 ||
              (req_len == 0 && io->len >= MG_MAX_HTTP_REQUEST_SIZE))) {
            DBG(("invalid request"));
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
         } else if (req_len == 0) {
            /* Do nothing, request is not yet fully buffered */
         }
#ifndef MG_DISABLE_HTTP_WEBSOCKET
         else if (nc->listener == NULL &&
                  mg_get_http_header(hm, "Sec-WebSocket-Accept")) {
            /* We're websocket client, got handshake response from server. */
            /* TODO(lsm): check the validity of accept Sec-WebSocket-Accept */
            mbuf_remove(io, req_len);
            nc->proto_handler = mg_websocket_handler;
            nc->flags |= MG_F_IS_WEBSOCKET;
            mg_call(nc, nc->handler, MG_EV_WEBSOCKET_HANDSHAKE_DONE, NULL);
            mg_websocket_handler(nc, MG_EV_RECV, ev_data);
         } else if (nc->listener != NULL &&
                    (vec = mg_get_http_header(hm, "Sec-WebSocket-Key")) != NULL) {
            /* This is a websocket request. Switch protocol handlers. */
            mbuf_remove(io, req_len);
            nc->proto_handler = mg_websocket_handler;
            nc->flags |= MG_F_IS_WEBSOCKET;
            
            /* Send handshake */
            mg_call(nc, nc->handler, MG_EV_WEBSOCKET_HANDSHAKE_REQUEST, hm);
            if (!(nc->flags & MG_F_CLOSE_IMMEDIATELY)) {
               if (nc->send_mbuf.len == 0) {
                  mg_ws_handshake(nc, vec);
               }
               mg_call(nc, nc->handler, MG_EV_WEBSOCKET_HANDSHAKE_DONE, NULL);
               mg_websocket_handler(nc, MG_EV_RECV, ev_data);
            }
#endif /* MG_DISABLE_HTTP_WEBSOCKET */
         } else if (hm->message.len <= io->len) {
            int trigger_ev = nc->listener ? MG_EV_HTTP_REQUEST : MG_EV_HTTP_REPLY;
            
            /* Whole HTTP message is fully buffered, call event handler */
            
#ifdef MG_ENABLE_JAVASCRIPT
            v7_val_t v1, v2, headers, req, args, res;
            struct v7 *v7 = nc->mgr->v7;
            const char *ev_name = trigger_ev == MG_EV_HTTP_REPLY ? "onsnd" : "onrcv";
            int i, js_callback_handled_request = 0;
            
            if (v7 != NULL) {
               /* Lookup JS callback */
               v1 = v7_get(v7, v7_get_global(v7), "Http", ~0);
               v2 = v7_get(v7, v1, ev_name, ~0);
               
               /* Create callback params. TODO(lsm): own/disown those */
               args = v7_mk_array(v7);
               req = v7_mk_object(v7);
               headers = v7_mk_object(v7);
               
               /* Populate request object */
               v7_set(v7, req, "method", ~0,
                      v7_mk_string(v7, hm->method.p, hm->method.len, 1));
               v7_set(v7, req, "uri", ~0, v7_mk_string(v7, hm->uri.p, hm->uri.len, 1));
               v7_set(v7, req, "body", ~0,
                      v7_mk_string(v7, hm->body.p, hm->body.len, 1));
               v7_set(v7, req, "headers", ~0, headers);
               for (i = 0; hm->header_names[i].len > 0; i++) {
                  const struct mg_str *name = &hm->header_names[i];
                  const struct mg_str *value = &hm->header_values[i];
                  v7_set(v7, headers, name->p, name->len,
                         v7_mk_string(v7, value->p, value->len, 1));
               }
               
               /* Invoke callback. TODO(lsm): report errors */
               v7_array_push(v7, args, v7_mk_foreign(nc));
               v7_array_push(v7, args, req);
               if (v7_apply(v7, v2, v7_mk_undefined(), args, &res) == V7_OK &&
                   v7_is_truthy(v7, res)) {
                  js_callback_handled_request++;
               }
            }
            
            /* If JS callback returns true, stop request processing */
            if (js_callback_handled_request) {
               nc->flags |= MG_F_SEND_AND_CLOSE;
            } else {
               mg_http_call_endpoint_handler(nc, trigger_ev, hm);
            }
#else
            mg_http_call_endpoint_handler(nc, trigger_ev, hm);
#endif
            mbuf_remove(io, hm->message.len);
         }
      }
      (void) pd;
   }
   
   static size_t mg_get_line_len(const char *buf, size_t buf_len) {
      size_t len = 0;
      while (len < buf_len && buf[len] != '\n') len++;
      return len == buf_len ? 0 : len + 1;
   }
   
#ifdef MG_ENABLE_HTTP_STREAMING_MULTIPART
   static void mg_http_multipart_begin(struct mg_connection *nc,
                                       struct http_message *hm, int req_len) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
      struct mg_str *ct;
      struct mbuf *io = &nc->recv_mbuf;
      
      char boundary[100];
      int boundary_len;
      
      if (nc->listener == NULL) {
         /* No streaming for replies now */
         goto exit_mp;
      }
      
      ct = mg_get_http_header(hm, "Content-Type");
      if (ct == NULL) {
         /* We need more data - or it isn't multipart mesage */
         goto exit_mp;
      }
      
      /* Content-type should start with "multipart" */
      if (ct->len < 9 || strncmp(ct->p, "multipart", 9) != 0) {
         goto exit_mp;
      }
      
      boundary_len =
      mg_http_parse_header(ct, "boundary", boundary, sizeof(boundary));
      if (boundary_len == 0) {
         /*
          * Content type is multipart, but there is no boundary,
          * probably malformed request
          */
         nc->flags = MG_F_CLOSE_IMMEDIATELY;
         DBG(("invalid request"));
         goto exit_mp;
      }
      
      /* If we reach this place - that is multipart request */
      
      if (pd->mp_stream.boundary != NULL) {
         /*
          * Another streaming request was in progress,
          * looks like protocol error
          */
         nc->flags |= MG_F_CLOSE_IMMEDIATELY;
      } else {
         pd->mp_stream.boundary = strdup(boundary);
         pd->mp_stream.boundary_len = strlen(boundary);
         pd->mp_stream.var_name = pd->mp_stream.file_name = NULL;
         
         pd->endpoint_handler = mg_http_get_endpoint_handler(nc->listener, &hm->uri);
         if (pd->endpoint_handler == NULL) {
            pd->endpoint_handler = nc->handler;
         }
         
         mg_call(nc, pd->endpoint_handler, MG_EV_HTTP_MULTIPART_REQUEST, hm);
         
         mbuf_remove(io, req_len);
      }
   exit_mp:
      ;
   }
   
#define CONTENT_DISPOSITION "Content-Disposition: "
   
   static void mg_http_multipart_call_handler(struct mg_connection *c, int ev,
                                              const char *data, size_t data_len) {
      struct mg_http_multipart_part mp;
      struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
      memset(&mp, 0, sizeof(mp));
      
      mp.var_name = pd->mp_stream.var_name;
      mp.file_name = pd->mp_stream.file_name;
      mp.user_data = pd->mp_stream.user_data;
      mp.data.p = data;
      mp.data.len = data_len;
      mg_call(c, pd->endpoint_handler, ev, &mp);
      pd->mp_stream.user_data = mp.user_data;
   }
   
   static int mg_http_multipart_got_chunk(struct mg_connection *c) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
      struct mbuf *io = &c->recv_mbuf;
      
      mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_DATA, io->buf,
                                     pd->mp_stream.prev_io_len);
      mbuf_remove(io, pd->mp_stream.prev_io_len);
      pd->mp_stream.prev_io_len = 0;
      pd->mp_stream.state = MPS_WAITING_FOR_CHUNK;
      
      return 0;
   }
   
   static int mg_http_multipart_finalize(struct mg_connection *c) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
      
      mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_END, NULL, 0);
      mg_http_free_proto_data_mp_stream(&pd->mp_stream);
      pd->mp_stream.state = MPS_FINISHED;
      
      return 1;
   }
   
   static int mg_http_multipart_wait_for_boundary(struct mg_connection *c) {
      const char *boundary;
      struct mbuf *io = &c->recv_mbuf;
      struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
      
      if ((int) io->len < pd->mp_stream.boundary_len + 2) {
         return 0;
      }
      
      boundary = c_strnstr(io->buf, pd->mp_stream.boundary, io->len);
      if (boundary != NULL) {
         if (io->len - (boundary - io->buf) < 4) {
            return 0;
         }
         if (memcmp(boundary + pd->mp_stream.boundary_len, "--", 2) == 0) {
            pd->mp_stream.state = MPS_FINALIZE;
         } else {
            pd->mp_stream.state = MPS_GOT_BOUNDARY;
         }
      } else {
         return 0;
      }
      
      return 1;
   }
   
   static int mg_http_multipart_process_boundary(struct mg_connection *c) {
      int data_size;
      const char *boundary, *block_begin;
      struct mbuf *io = &c->recv_mbuf;
      struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
      char file_name[100], var_name[100];
      int line_len;
      boundary = c_strnstr(io->buf, pd->mp_stream.boundary, io->len);
      block_begin = boundary + pd->mp_stream.boundary_len + 2;
      data_size = io->len - (block_begin - io->buf);
      
      while (data_size > 0 &&
             (line_len = mg_get_line_len(block_begin, data_size)) != 0) {
         if (line_len > (int) sizeof(CONTENT_DISPOSITION) &&
             mg_ncasecmp(block_begin, CONTENT_DISPOSITION,
                         sizeof(CONTENT_DISPOSITION) - 1) == 0) {
                struct mg_str header;
                
                header.p = block_begin + sizeof(CONTENT_DISPOSITION) - 1;
                header.len = line_len - sizeof(CONTENT_DISPOSITION) - 1;
                mg_http_parse_header(&header, "name", var_name, sizeof(var_name) - 2);
                mg_http_parse_header(&header, "filename", file_name,
                                     sizeof(file_name) - 2);
                block_begin += line_len;
                data_size -= line_len;
                continue;
             }
         
         if (line_len == 2 && mg_ncasecmp(block_begin, "\r\n", 2) == 0) {
            mbuf_remove(io, block_begin - io->buf + 2);
            
            if (pd->mp_stream.processing_part != 0) {
               mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_END, NULL, 0);
            }
            
            free((void *) pd->mp_stream.file_name);
            pd->mp_stream.file_name = strdup(file_name);
            free((void *) pd->mp_stream.var_name);
            pd->mp_stream.var_name = strdup(var_name);
            
            mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_BEGIN, NULL, 0);
            pd->mp_stream.state = MPS_WAITING_FOR_CHUNK;
            pd->mp_stream.processing_part++;
            return 1;
         }
         
         block_begin += line_len;
      }
      
      pd->mp_stream.state = MPS_WAITING_FOR_BOUNDARY;
      
      return 0;
   }
   
   static int mg_http_multipart_continue_wait_for_chunk(struct mg_connection *c) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
      struct mbuf *io = &c->recv_mbuf;
      
      const char *boundary;
      if ((int) io->len < pd->mp_stream.boundary_len + 6 /* \r\n, --, -- */) {
         return 0;
      }
      
      boundary = c_strnstr(io->buf, pd->mp_stream.boundary, io->len);
      if (boundary == NULL && pd->mp_stream.prev_io_len == 0) {
         pd->mp_stream.prev_io_len = io->len;
         return 0;
      } else if (boundary == NULL &&
                 (int) io->len >
                 pd->mp_stream.prev_io_len + pd->mp_stream.boundary_len + 4) {
         pd->mp_stream.state = MPS_GOT_CHUNK;
         return 1;
      } else if (boundary != NULL) {
         int data_size = (boundary - io->buf - 4);
         mg_http_multipart_call_handler(c, MG_EV_HTTP_PART_DATA, io->buf, data_size);
         mbuf_remove(io, (boundary - io->buf));
         pd->mp_stream.prev_io_len = 0;
         pd->mp_stream.state = MPS_WAITING_FOR_BOUNDARY;
         return 1;
      } else {
         return 0;
      }
   }
   
   static void mg_http_multipart_continue(struct mg_connection *c) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(c);
      while (1) {
         switch (pd->mp_stream.state) {
            case MPS_BEGIN: {
               pd->mp_stream.state = MPS_WAITING_FOR_BOUNDARY;
               break;
            }
            case MPS_WAITING_FOR_BOUNDARY: {
               if (mg_http_multipart_wait_for_boundary(c) == 0) {
                  return;
               }
               break;
            }
            case MPS_GOT_BOUNDARY: {
               if (mg_http_multipart_process_boundary(c) == 0) {
                  return;
               }
               break;
            }
            case MPS_WAITING_FOR_CHUNK: {
               if (mg_http_multipart_continue_wait_for_chunk(c) == 0) {
                  return;
               }
               break;
            }
            case MPS_GOT_CHUNK: {
               if (mg_http_multipart_got_chunk(c) == 0) {
                  return;
               }
               break;
            }
            case MPS_FINALIZE: {
               if (mg_http_multipart_finalize(c) == 0) {
                  return;
               }
               break;
            }
            case MPS_FINISHED: {
               mbuf_remove(&c->recv_mbuf, c->recv_mbuf.len);
               return;
            }
         }
      }
   }
   
   struct file_upload_state {
      char *lfn;
      size_t num_recd;
      FILE *fp;
   };
   
   void mg_file_upload_handler(struct mg_connection *nc, int ev, void *ev_data,
                               mg_fu_fname_fn local_name_fn) {
      switch (ev) {
         case MG_EV_HTTP_PART_BEGIN: {
            struct mg_http_multipart_part *mp =
            (struct mg_http_multipart_part *) ev_data;
            struct file_upload_state *fus =
            (struct file_upload_state *) calloc(1, sizeof(*fus));
            mp->user_data = NULL;
            
            struct mg_str lfn = local_name_fn(nc, mg_mk_str(mp->file_name));
            if (lfn.p == NULL || lfn.len == 0) {
               LOG(LL_ERROR, ("%p Not allowed to upload %s", nc, mp->file_name));
               mg_printf(nc,
                         "HTTP/1.1 403 Not Allowed\r\n"
                         "Content-Type: text/plain\r\n"
                         "Connection: close\r\n\r\n"
                         "Not allowed to upload %s\r\n",
                         mp->file_name);
               nc->flags |= MG_F_SEND_AND_CLOSE;
               return;
            }
            fus->lfn = (char *) malloc(lfn.len + 1);
            memcpy(fus->lfn, lfn.p, lfn.len);
            fus->lfn[lfn.len] = '\0';
            if (lfn.p != mp->file_name) free((char *) lfn.p);
            LOG(LL_DEBUG,
                ("%p Receiving file %s -> %s", nc, mp->file_name, fus->lfn));
            fus->fp = fopen(fus->lfn, "w");
            if (fus->fp == NULL) {
               mg_printf(nc,
                         "HTTP/1.1 500 Internal Server Error\r\n"
                         "Content-Type: text/plain\r\n"
                         "Connection: close\r\n\r\n");
               LOG(LL_ERROR, ("Failed to open %s: %d\n", fus->lfn, errno));
               mg_printf(nc, "Failed to open %s: %d\n", fus->lfn, errno);
               /* Do not close the connection just yet, discard remainder of the data.
                * This is because at the time of writing some browsers (Chrome) fail to
                * render response before all the data is sent. */
            }
            mp->user_data = (void *) fus;
            break;
         }
         case MG_EV_HTTP_PART_DATA: {
            struct mg_http_multipart_part *mp =
            (struct mg_http_multipart_part *) ev_data;
            struct file_upload_state *fus =
            (struct file_upload_state *) mp->user_data;
            if (fus == NULL || fus->fp == NULL) break;
            if (fwrite(mp->data.p, 1, mp->data.len, fus->fp) != mp->data.len) {
               LOG(LL_ERROR, ("Failed to write to %s: %d, wrote %d", fus->lfn, errno,
                              (int) fus->num_recd));
               if (errno == ENOSPC
#ifdef SPIFFS_ERR_FULL
                   || errno == SPIFFS_ERR_FULL
#endif
                   ) {
                  mg_printf(nc,
                            "HTTP/1.1 413 Payload Too Large\r\n"
                            "Content-Type: text/plain\r\n"
                            "Connection: close\r\n\r\n");
                  mg_printf(nc, "Failed to write to %s: no space left; wrote %d\r\n",
                            fus->lfn, (int) fus->num_recd);
               } else {
                  mg_printf(nc,
                            "HTTP/1.1 500 Internal Server Error\r\n"
                            "Content-Type: text/plain\r\n"
                            "Connection: close\r\n\r\n");
                  mg_printf(nc, "Failed to write to %s: %d, wrote %d", mp->file_name,
                            errno, (int) fus->num_recd);
               }
               fclose(fus->fp);
               remove(fus->lfn);
               fus->fp = NULL;
               /* Do not close the connection just yet, discard remainder of the data.
                * This is because at the time of writing some browsers (Chrome) fail to
                * render response before all the data is sent. */
               return;
            }
            fus->num_recd += mp->data.len;
            LOG(LL_DEBUG, ("%p rec'd %d bytes, %d total", nc, (int) mp->data.len,
                           (int) fus->num_recd));
            break;
         }
         case MG_EV_HTTP_PART_END: {
            struct mg_http_multipart_part *mp =
            (struct mg_http_multipart_part *) ev_data;
            struct file_upload_state *fus =
            (struct file_upload_state *) mp->user_data;
            if (fus == NULL) break;
            if (mp->status >= 0 && fus->fp != NULL) {
               LOG(LL_DEBUG, ("%p Uploaded %s (%s), %d bytes", nc, mp->file_name,
                              fus->lfn, (int) fus->num_recd));
               mg_printf(nc,
                         "HTTP/1.1 200 OK\r\n"
                         "Content-Type: text/plain\r\n"
                         "Connection: close\r\n\r\n"
                         "Ok, %s - %d bytes.\r\n",
                         mp->file_name, (int) fus->num_recd);
            } else {
               LOG(LL_ERROR, ("Failed to store %s (%s)", mp->file_name, fus->lfn));
               /*
                * mp->status < 0 means connection was terminated, so no reason to send
                * HTTP reply
                */
            }
            if (fus->fp != NULL) fclose(fus->fp);
            free(fus->lfn);
            free(fus);
            mp->user_data = NULL;
            nc->flags |= MG_F_SEND_AND_CLOSE;
            break;
         }
      }
   }
   
#endif /* MG_ENABLE_HTTP_STREAMING_MULTIPART */
   
   void mg_set_protocol_http_websocket(struct mg_connection *nc) {
      nc->proto_handler = mg_http_handler;
   }
   
#ifndef MG_DISABLE_HTTP_WEBSOCKET
   
   void mg_send_websocket_handshake2(struct mg_connection *nc, const char *path,
                                     const char *host, const char *protocol,
                                     const char *extra_headers) {
      /* pretty poor source of randomness, TODO fix */
      unsigned long random = (unsigned long) path;
      char key[sizeof(random) * 3];
      
      mg_base64_encode((unsigned char *) &random, sizeof(random), key);
      mg_printf(nc,
                "GET %s HTTP/1.1\r\n"
                "Upgrade: websocket\r\n"
                "Connection: Upgrade\r\n"
                "Sec-WebSocket-Version: 13\r\n"
                "Sec-WebSocket-Key: %s\r\n",
                path, key);
      
      /* TODO(mkm): take default hostname from http proto data if host == NULL */
      if (host != MG_WS_NO_HOST_HEADER_MAGIC) {
         mg_printf(nc, "Host: %s\r\n", host);
      }
      if (protocol != NULL) {
         mg_printf(nc, "Sec-WebSocket-Protocol: %s\r\n", protocol);
      }
      if (extra_headers != NULL) {
         mg_printf(nc, "%s", extra_headers);
      }
      mg_printf(nc, "\r\n");
   }
   
   void mg_send_websocket_handshake(struct mg_connection *nc, const char *path,
                                    const char *extra_headers) {
      mg_send_websocket_handshake2(nc, path, MG_WS_NO_HOST_HEADER_MAGIC, NULL,
                                   extra_headers);
   }
   
#endif /* MG_DISABLE_HTTP_WEBSOCKET */
   
   void mg_send_response_line(struct mg_connection *nc, int status_code,
                              const char *extra_headers) {
      const char *status_message = "OK";
      switch (status_code) {
         case 206:
            status_message = "Partial Content";
            break;
         case 301:
            status_message = "Moved";
            break;
         case 302:
            status_message = "Found";
            break;
         case 401:
            status_message = "Unauthorized";
            break;
         case 403:
            status_message = "Forbidden";
            break;
         case 404:
            status_message = "Not Found";
            break;
         case 416:
            status_message = "Requested range not satisfiable";
            break;
         case 418:
            status_message = "I'm a teapot";
            break;
         case 500:
            status_message = "Internal Server Error";
            break;
      }
      mg_printf(nc, "HTTP/1.1 %d %s\r\nServer: %s\r\n", status_code, status_message,
                mg_version_header);
      if (extra_headers != NULL) {
         mg_printf(nc, "%s\r\n", extra_headers);
      }
   }
   
   void mg_send_head(struct mg_connection *c, int status_code,
                     int64_t content_length, const char *extra_headers) {
      mg_send_response_line(c, status_code, extra_headers);
      if (content_length < 0) {
         mg_printf(c, "%s", "Transfer-Encoding: chunked\r\n");
      } else {
         mg_printf(c, "Content-Length: %" INT64_FMT "\r\n", content_length);
      }
      mg_send(c, "\r\n", 2);
   }
   
#ifdef MG_DISABLE_FILESYSTEM
   void mg_serve_http(struct mg_connection *nc, struct http_message *hm,
                      struct mg_serve_http_opts opts) {
      mg_send_head(nc, 501, 0, NULL);
   }
#else
   static void mg_http_send_error(struct mg_connection *nc, int code,
                                  const char *reason) {
      if (!reason) reason = "";
      DBG(("%p %d %s", nc, code, reason));
      mg_send_head(nc, code, strlen(reason),
                   "Content-Type: text/plain\r\nConnection: close");
      mg_send(nc, reason, strlen(reason));
      nc->flags |= MG_F_SEND_AND_CLOSE;
   }
#ifndef MG_DISABLE_SSI
   static void mg_send_ssi_file(struct mg_connection *, const char *, FILE *, int,
                                const struct mg_serve_http_opts *);
   
   static void mg_send_file_data(struct mg_connection *nc, FILE *fp) {
      char buf[BUFSIZ];
      size_t n;
      while ((n = fread(buf, 1, sizeof(buf), fp)) > 0) {
         mg_send(nc, buf, n);
      }
   }
   
   static void mg_do_ssi_include(struct mg_connection *nc, const char *ssi,
                                 char *tag, int include_level,
                                 const struct mg_serve_http_opts *opts) {
      char file_name[BUFSIZ], path[MAX_PATH_SIZE], *p;
      FILE *fp;
      
      /*
       * sscanf() is safe here, since send_ssi_file() also uses buffer
       * of size MG_BUF_LEN to get the tag. So strlen(tag) is always < MG_BUF_LEN.
       */
      if (sscanf(tag, " virtual=\"%[^\"]\"", file_name) == 1) {
         /* File name is relative to the webserver root */
         snprintf(path, sizeof(path), "%s/%s", opts->document_root, file_name);
      } else if (sscanf(tag, " abspath=\"%[^\"]\"", file_name) == 1) {
         /*
          * File name is relative to the webserver working directory
          * or it is absolute system path
          */
         snprintf(path, sizeof(path), "%s", file_name);
      } else if (sscanf(tag, " file=\"%[^\"]\"", file_name) == 1 ||
                 sscanf(tag, " \"%[^\"]\"", file_name) == 1) {
         /* File name is relative to the currect document */
         snprintf(path, sizeof(path), "%s", ssi);
         if ((p = strrchr(path, DIRSEP)) != NULL) {
            p[1] = '\0';
         }
         snprintf(path + strlen(path), sizeof(path) - strlen(path), "%s", file_name);
      } else {
         mg_printf(nc, "Bad SSI #include: [%s]", tag);
         return;
      }
      
      if ((fp = fopen(path, "rb")) == NULL) {
         mg_printf(nc, "SSI include error: fopen(%s): %s", path, strerror(errno));
      } else {
         mg_set_close_on_exec(fileno(fp));
         if (mg_match_prefix(opts->ssi_pattern, strlen(opts->ssi_pattern), path) >
             0) {
            mg_send_ssi_file(nc, path, fp, include_level + 1, opts);
         } else {
            mg_send_file_data(nc, fp);
         }
         fclose(fp);
      }
   }
   
#ifndef MG_DISABLE_POPEN
   static void do_ssi_exec(struct mg_connection *nc, char *tag) {
      char cmd[BUFSIZ];
      FILE *fp;
      
      if (sscanf(tag, " \"%[^\"]\"", cmd) != 1) {
         mg_printf(nc, "Bad SSI #exec: [%s]", tag);
      } else if ((fp = popen(cmd, "r")) == NULL) {
         mg_printf(nc, "Cannot SSI #exec: [%s]: %s", cmd, strerror(errno));
      } else {
         mg_send_file_data(nc, fp);
         pclose(fp);
      }
   }
#endif /* !MG_DISABLE_POPEN */
   
   static void mg_do_ssi_call(struct mg_connection *nc, char *tag) {
      mg_call(nc, NULL, MG_EV_SSI_CALL, tag);
   }
   
   /*
    * SSI directive has the following format:
    * <!--#directive parameter=value parameter=value -->
    */
   static void mg_send_ssi_file(struct mg_connection *nc, const char *path,
                                FILE *fp, int include_level,
                                const struct mg_serve_http_opts *opts) {
      static const struct mg_str btag = MG_MK_STR("<!--#");
      static const struct mg_str d_include = MG_MK_STR("include");
      static const struct mg_str d_call = MG_MK_STR("call");
#ifndef MG_DISABLE_POPEN
      static const struct mg_str d_exec = MG_MK_STR("exec");
#endif
      char buf[BUFSIZ], *p = buf + btag.len; /* p points to SSI directive */
      int ch, len, in_ssi_tag;
      
      if (include_level > 10) {
         mg_printf(nc, "SSI #include level is too deep (%s)", path);
         return;
      }
      
      in_ssi_tag = len = 0;
      while ((ch = fgetc(fp)) != EOF) {
         if (in_ssi_tag && ch == '>' && buf[len - 1] == '-' && buf[len - 2] == '-') {
            size_t i = len - 2;
            in_ssi_tag = 0;
            
            /* Trim closing --> */
            buf[i--] = '\0';
            while (i > 0 && buf[i] == ' ') {
               buf[i--] = '\0';
            }
            
            /* Handle known SSI directives */
            if (memcmp(p, d_include.p, d_include.len) == 0) {
               mg_do_ssi_include(nc, path, p + d_include.len + 1, include_level, opts);
            } else if (memcmp(p, d_call.p, d_call.len) == 0) {
               mg_do_ssi_call(nc, p + d_call.len + 1);
#ifndef MG_DISABLE_POPEN
            } else if (memcmp(p, d_exec.p, d_exec.len) == 0) {
               do_ssi_exec(nc, p + d_exec.len + 1);
#endif
            } else {
               /* Silently ignore unknown SSI directive. */
            }
            len = 0;
         } else if (ch == '<') {
            in_ssi_tag = 1;
            if (len > 0) {
               mg_send(nc, buf, (size_t) len);
            }
            len = 0;
            buf[len++] = ch & 0xff;
         } else if (in_ssi_tag) {
            if (len == (int) btag.len && memcmp(buf, btag.p, btag.len) != 0) {
               /* Not an SSI tag */
               in_ssi_tag = 0;
            } else if (len == (int) sizeof(buf) - 2) {
               mg_printf(nc, "%s: SSI tag is too large", path);
               len = 0;
            }
            buf[len++] = ch & 0xff;
         } else {
            buf[len++] = ch & 0xff;
            if (len == (int) sizeof(buf)) {
               mg_send(nc, buf, (size_t) len);
               len = 0;
            }
         }
      }
      
      /* Send the rest of buffered data */
      if (len > 0) {
         mg_send(nc, buf, (size_t) len);
      }
   }
   
   static void mg_handle_ssi_request(struct mg_connection *nc, const char *path,
                                     const struct mg_serve_http_opts *opts) {
      FILE *fp;
      struct mg_str mime_type;
      
      if ((fp = fopen(path, "rb")) == NULL) {
         mg_http_send_error(nc, 404, NULL);
      } else {
         mg_set_close_on_exec(fileno(fp));
         
         mime_type = mg_get_mime_type(path, "text/plain", opts);
         mg_send_response_line(nc, 200, opts->extra_headers);
         mg_printf(nc,
                   "Content-Type: %.*s\r\n"
                   "Connection: close\r\n\r\n",
                   (int) mime_type.len, mime_type.p);
         mg_send_ssi_file(nc, path, fp, 0, opts);
         fclose(fp);
         nc->flags |= MG_F_SEND_AND_CLOSE;
      }
   }
#else
   static void mg_handle_ssi_request(struct mg_connection *nc, const char *path,
                                     const struct mg_serve_http_opts *opts) {
      (void) path;
      (void) opts;
      mg_http_send_error(nc, 500, "SSI disabled");
   }
#endif /* MG_DISABLE_SSI */
   
   static void mg_http_construct_etag(char *buf, size_t buf_len,
                                      const cs_stat_t *st) {
      snprintf(buf, buf_len, "\"%lx.%" INT64_FMT "\"", (unsigned long) st->st_mtime,
               (int64_t) st->st_size);
   }
   static void mg_gmt_time_string(char *buf, size_t buf_len, time_t *t) {
      strftime(buf, buf_len, "%a, %d %b %Y %H:%M:%S GMT", gmtime(t));
   }
   
   static int mg_http_parse_range_header(const struct mg_str *header, int64_t *a,
                                         int64_t *b) {
      /*
       * There is no snscanf. Headers are not guaranteed to be NUL-terminated,
       * so we have this. Ugh.
       */
      int result;
      char *p = (char *) MG_MALLOC(header->len + 1);
      if (p == NULL) return 0;
      memcpy(p, header->p, header->len);
      p[header->len] = '\0';
      result = sscanf(p, "bytes=%" INT64_FMT "-%" INT64_FMT, a, b);
      MG_FREE(p);
      return result;
   }
   
   static void mg_http_send_file2(struct mg_connection *nc, const char *path,
                                  cs_stat_t *st, struct http_message *hm,
                                  struct mg_serve_http_opts *opts) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
      struct mg_str mime_type;
      
      DBG(("%p [%s]", nc, path));
      mg_http_free_proto_data_file(&pd->file);
      if ((pd->file.fp = fopen(path, "rb")) == NULL) {
         int code;
         switch (errno) {
            case EACCES:
               code = 403;
               break;
            case ENOENT:
               code = 404;
               break;
            default:
               code = 500;
         };
         mg_http_send_error(nc, code, "Open failed");
      } else if (mg_match_prefix(opts->ssi_pattern, strlen(opts->ssi_pattern),
                                 path) > 0) {
         mg_handle_ssi_request(nc, path, opts);
      } else {
         char etag[50], current_time[50], last_modified[50], range[70];
         time_t t = time(NULL);
         int64_t r1 = 0, r2 = 0, cl = st->st_size;
         struct mg_str *range_hdr = mg_get_http_header(hm, "Range");
         int n, status_code = 200;
         
         /* Handle Range header */
         range[0] = '\0';
         if (range_hdr != NULL &&
             (n = mg_http_parse_range_header(range_hdr, &r1, &r2)) > 0 && r1 >= 0 &&
             r2 >= 0) {
            /* If range is specified like "400-", set second limit to content len */
            if (n == 1) {
               r2 = cl - 1;
            }
            if (r1 > r2 || r2 >= cl) {
               status_code = 416;
               cl = 0;
               snprintf(range, sizeof(range),
                        "Content-Range: bytes */%" INT64_FMT "\r\n",
                        (int64_t) st->st_size);
            } else {
               status_code = 206;
               cl = r2 - r1 + 1;
               snprintf(range, sizeof(range), "Content-Range: bytes %" INT64_FMT
                        "-%" INT64_FMT "/%" INT64_FMT "\r\n",
                        r1, r1 + cl - 1, (int64_t) st->st_size);
#if _FILE_OFFSET_BITS == 64 || _POSIX_C_SOURCE >= 200112L || \
_XOPEN_SOURCE >= 600
               fseeko(pd->file.fp, r1, SEEK_SET);
#else
               fseek(pd->file.fp, r1, SEEK_SET);
#endif
            }
         }
         
#ifndef MG_DISABLE_HTTP_KEEP_ALIVE
         {
         struct mg_str *conn_hdr = mg_get_http_header(hm, "Connection");
         if (conn_hdr != NULL) {
            pd->file.keepalive = (mg_vcasecmp(conn_hdr, "keep-alive") == 0);
         } else {
            pd->file.keepalive = (mg_vcmp(&hm->proto, "HTTP/1.1") == 0);
         }
         }
#endif
         
         mg_http_construct_etag(etag, sizeof(etag), st);
         mg_gmt_time_string(current_time, sizeof(current_time), &t);
         mg_gmt_time_string(last_modified, sizeof(last_modified), &st->st_mtime);
         mime_type = mg_get_mime_type(path, "text/plain", opts);
         /*
          * Content length casted to size_t because:
          * 1) that's the maximum buffer size anyway
          * 2) ESP8266 RTOS SDK newlib vprintf cannot contain a 64bit arg at non-last
          *    position
          * TODO(mkm): fix ESP8266 RTOS SDK
          */
         mg_send_response_line(nc, status_code, opts->extra_headers);
         mg_printf(nc,
                   "Date: %s\r\n"
                   "Last-Modified: %s\r\n"
                   "Accept-Ranges: bytes\r\n"
                   "Content-Type: %.*s\r\n"
                   "Connection: %s\r\n"
                   "Content-Length: %" SIZE_T_FMT
                   "\r\n"
                   "%sEtag: %s\r\n\r\n",
                   current_time, last_modified, (int) mime_type.len, mime_type.p,
                   (pd->file.keepalive ? "keep-alive" : "close"), (size_t) cl, range,
                   etag);
         
         pd->file.cl = cl;
         pd->file.type = DATA_FILE;
         mg_http_transfer_file_data(nc);
      }
   }
   
#endif
   
   int mg_url_decode(const char *src, int src_len, char *dst, int dst_len,
                     int is_form_url_encoded) {
      int i, j, a, b;
#define HEXTOI(x) (isdigit(x) ? x - '0' : x - 'W')
      
      for (i = j = 0; i < src_len && j < dst_len - 1; i++, j++) {
         if (src[i] == '%') {
            if (i < src_len - 2 && isxdigit(*(const unsigned char *) (src + i + 1)) &&
                isxdigit(*(const unsigned char *) (src + i + 2))) {
               a = tolower(*(const unsigned char *) (src + i + 1));
               b = tolower(*(const unsigned char *) (src + i + 2));
               dst[j] = (char) ((HEXTOI(a) << 4) | HEXTOI(b));
               i += 2;
            } else {
               return -1;
            }
         } else if (is_form_url_encoded && src[i] == '+') {
            dst[j] = ' ';
         } else {
            dst[j] = src[i];
         }
      }
      
      dst[j] = '\0'; /* Null-terminate the destination */
      
      return i >= src_len ? j : -1;
   }
   
   int mg_get_http_var(const struct mg_str *buf, const char *name, char *dst,
                       size_t dst_len) {
      const char *p, *e, *s;
      size_t name_len;
      int len;
      
      if (dst == NULL || dst_len == 0) {
         len = -2;
      } else if (buf->p == NULL || name == NULL || buf->len == 0) {
         len = -1;
         dst[0] = '\0';
      } else {
         name_len = strlen(name);
         e = buf->p + buf->len;
         len = -1;
         dst[0] = '\0';
         
         for (p = buf->p; p + name_len < e; p++) {
            if ((p == buf->p || p[-1] == '&') && p[name_len] == '=' &&
                !mg_ncasecmp(name, p, name_len)) {
               p += name_len + 1;
               s = (const char *) memchr(p, '&', (size_t)(e - p));
               if (s == NULL) {
                  s = e;
               }
               len = mg_url_decode(p, (size_t)(s - p), dst, dst_len, 1);
               if (len == -1) {
                  len = -2;
               }
               break;
            }
         }
      }
      
      return len;
   }
   
   void mg_send_http_chunk(struct mg_connection *nc, const char *buf, size_t len) {
      char chunk_size[50];
      int n;
      
      n = snprintf(chunk_size, sizeof(chunk_size), "%lX\r\n", (unsigned long) len);
      mg_send(nc, chunk_size, n);
      mg_send(nc, buf, len);
      mg_send(nc, "\r\n", 2);
   }
   
   void mg_printf_http_chunk(struct mg_connection *nc, const char *fmt, ...) {
      char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
      int len;
      va_list ap;
      
      va_start(ap, fmt);
      len = mg_avprintf(&buf, sizeof(mem), fmt, ap);
      va_end(ap);
      
      if (len >= 0) {
         mg_send_http_chunk(nc, buf, len);
      }
      
      /* LCOV_EXCL_START */
      if (buf != mem && buf != NULL) {
         MG_FREE(buf);
      }
      /* LCOV_EXCL_STOP */
   }
   
   void mg_printf_html_escape(struct mg_connection *nc, const char *fmt, ...) {
      char mem[MG_VPRINTF_BUFFER_SIZE], *buf = mem;
      int i, j, len;
      va_list ap;
      
      va_start(ap, fmt);
      len = mg_avprintf(&buf, sizeof(mem), fmt, ap);
      va_end(ap);
      
      if (len >= 0) {
         for (i = j = 0; i < len; i++) {
            if (buf[i] == '<' || buf[i] == '>') {
               mg_send(nc, buf + j, i - j);
               mg_send(nc, buf[i] == '<' ? "&lt;" : "&gt;", 4);
               j = i + 1;
            }
         }
         mg_send(nc, buf + j, i - j);
      }
      
      /* LCOV_EXCL_START */
      if (buf != mem && buf != NULL) {
         MG_FREE(buf);
      }
      /* LCOV_EXCL_STOP */
   }
   
   int mg_http_parse_header(struct mg_str *hdr, const char *var_name, char *buf,
                            size_t buf_size) {
      int ch = ' ', ch1 = ',', len = 0, n = strlen(var_name);
      const char *p, *end = hdr ? hdr->p + hdr->len : NULL, *s = NULL;
      
      if (buf != NULL && buf_size > 0) buf[0] = '\0';
      if (hdr == NULL) return 0;
      
      /* Find where variable starts */
      for (s = hdr->p; s != NULL && s + n < end; s++) {
         if ((s == hdr->p || s[-1] == ch || s[-1] == ch1) && s[n] == '=' &&
             !memcmp(s, var_name, n))
            break;
      }
      
      if (s != NULL && &s[n + 1] < end) {
         s += n + 1;
         if (*s == '"' || *s == '\'') {
            ch = ch1 = *s++;
         }
         p = s;
         while (p < end && p[0] != ch && p[0] != ch1 && len < (int) buf_size) {
            if (ch != ' ' && p[0] == '\\' && p[1] == ch) p++;
            buf[len++] = *p++;
         }
         if (len >= (int) buf_size || (ch != ' ' && *p != ch)) {
            len = 0;
         } else {
            if (len > 0 && s[len - 1] == ',') len--;
            if (len > 0 && s[len - 1] == ';') len--;
            buf[len] = '\0';
         }
      }
      
      return len;
   }
   
#ifndef MG_DISABLE_FILESYSTEM
   static int mg_is_file_hidden(const char *path,
                                const struct mg_serve_http_opts *opts,
                                int exclude_specials) {
      const char *p1 = opts->per_directory_auth_file;
      const char *p2 = opts->hidden_file_pattern;
      
      /* Strip directory path from the file name */
      const char *pdir = strrchr(path, DIRSEP);
      if (pdir != NULL) {
         path = pdir + 1;
      }
      
      return (exclude_specials && (!strcmp(path, ".") || !strcmp(path, ".."))) ||
      (p1 != NULL &&
       mg_match_prefix(p1, strlen(p1), path) == (int) strlen(p1)) ||
      (p2 != NULL && mg_match_prefix(p2, strlen(p2), path) > 0);
   }
   
#ifndef MG_DISABLE_HTTP_DIGEST_AUTH
   static void mg_mkmd5resp(const char *method, size_t method_len, const char *uri,
                            size_t uri_len, const char *ha1, size_t ha1_len,
                            const char *nonce, size_t nonce_len, const char *nc,
                            size_t nc_len, const char *cnonce, size_t cnonce_len,
                            const char *qop, size_t qop_len, char *resp) {
      static const char colon[] = ":";
      static const size_t one = 1;
      char ha2[33];
      
      cs_md5(ha2, method, method_len, colon, one, uri, uri_len, NULL);
      cs_md5(resp, ha1, ha1_len, colon, one, nonce, nonce_len, colon, one, nc,
             nc_len, colon, one, cnonce, cnonce_len, colon, one, qop, qop_len,
             colon, one, ha2, sizeof(ha2) - 1, NULL);
   }
   
   int mg_http_create_digest_auth_header(char *buf, size_t buf_len,
                                         const char *method, const char *uri,
                                         const char *auth_domain, const char *user,
                                         const char *passwd) {
      static const char colon[] = ":", qop[] = "auth";
      static const size_t one = 1;
      char ha1[33], resp[33], cnonce[40];
      
      snprintf(cnonce, sizeof(cnonce), "%x", (unsigned int) time(NULL));
      cs_md5(ha1, user, (size_t) strlen(user), colon, one, auth_domain,
             (size_t) strlen(auth_domain), colon, one, passwd,
             (size_t) strlen(passwd), NULL);
      mg_mkmd5resp(method, strlen(method), uri, strlen(uri), ha1, sizeof(ha1) - 1,
                   cnonce, strlen(cnonce), "1", one, cnonce, strlen(cnonce), qop,
                   sizeof(qop) - 1, resp);
      return snprintf(buf, buf_len,
                      "Authorization: Digest username=\"%s\","
                      "realm=\"%s\",uri=\"%s\",qop=%s,nc=1,cnonce=%s,"
                      "nonce=%s,response=%s\r\n",
                      user, auth_domain, uri, qop, cnonce, cnonce, resp);
   }
   
   /*
    * Check for authentication timeout.
    * Clients send time stamp encoded in nonce. Make sure it is not too old,
    * to prevent replay attacks.
    * Assumption: nonce is a hexadecimal number of seconds since 1970.
    */
   static int mg_check_nonce(const char *nonce) {
      unsigned long now = (unsigned long) time(NULL);
      unsigned long val = (unsigned long) strtoul(nonce, NULL, 16);
      return now < val || now - val < 3600;
   }
   
   int mg_http_check_digest_auth(struct http_message *hm, const char *auth_domain,
                                 FILE *fp) {
      struct mg_str *hdr;
      char buf[128], f_user[sizeof(buf)], f_ha1[sizeof(buf)], f_domain[sizeof(buf)];
      char user[50], cnonce[33], response[40], uri[200], qop[20], nc[20], nonce[30];
      char expected_response[33];
      
      /* Parse "Authorization:" header, fail fast on parse error */
      if (hm == NULL || fp == NULL ||
          (hdr = mg_get_http_header(hm, "Authorization")) == NULL ||
          mg_http_parse_header(hdr, "username", user, sizeof(user)) == 0 ||
          mg_http_parse_header(hdr, "cnonce", cnonce, sizeof(cnonce)) == 0 ||
          mg_http_parse_header(hdr, "response", response, sizeof(response)) == 0 ||
          mg_http_parse_header(hdr, "uri", uri, sizeof(uri)) == 0 ||
          mg_http_parse_header(hdr, "qop", qop, sizeof(qop)) == 0 ||
          mg_http_parse_header(hdr, "nc", nc, sizeof(nc)) == 0 ||
          mg_http_parse_header(hdr, "nonce", nonce, sizeof(nonce)) == 0 ||
          mg_check_nonce(nonce) == 0) {
         return 0;
      }
      
      /*
       * Read passwords file line by line. If should have htdigest format,
       * i.e. each line should be a colon-separated sequence:
       * USER_NAME:DOMAIN_NAME:HA1_HASH_OF_USER_DOMAIN_AND_PASSWORD
       */
      while (fgets(buf, sizeof(buf), fp) != NULL) {
         if (sscanf(buf, "%[^:]:%[^:]:%s", f_user, f_domain, f_ha1) == 3 &&
             strcmp(user, f_user) == 0 &&
             /* NOTE(lsm): due to a bug in MSIE, we do not compare URIs */
             strcmp(auth_domain, f_domain) == 0) {
            /* User and domain matched, check the password */
            mg_mkmd5resp(
                         hm->method.p, hm->method.len, hm->uri.p,
                         hm->uri.len + (hm->query_string.len ? hm->query_string.len + 1 : 0),
                         f_ha1, strlen(f_ha1), nonce, strlen(nonce), nc, strlen(nc), cnonce,
                         strlen(cnonce), qop, strlen(qop), expected_response);
            return mg_casecmp(response, expected_response) == 0;
         }
      }
      
      /* None of the entries in the passwords file matched - return failure */
      return 0;
   }
   
   static int mg_is_authorized(struct http_message *hm, const char *path,
                               int is_directory, const char *domain,
                               const char *passwords_file,
                               int is_global_pass_file) {
      char buf[MG_MAX_PATH];
      const char *p;
      FILE *fp;
      int authorized = 1;
      
      if (domain != NULL && passwords_file != NULL) {
         if (is_global_pass_file) {
            fp = fopen(passwords_file, "r");
         } else if (is_directory) {
            snprintf(buf, sizeof(buf), "%s%c%s", path, DIRSEP, passwords_file);
            fp = fopen(buf, "r");
         } else {
            p = strrchr(path, DIRSEP);
            if (p == NULL) p = path;
            snprintf(buf, sizeof(buf), "%.*s%c%s", (int) (p - path), path, DIRSEP,
                     passwords_file);
            fp = fopen(buf, "r");
         }
         
         if (fp != NULL) {
            authorized = mg_http_check_digest_auth(hm, domain, fp);
            fclose(fp);
         }
      }
      
      DBG(("%s %s %d %d", path, passwords_file ? passwords_file : "",
           is_global_pass_file, authorized));
      return authorized;
   }
#else
   static int mg_is_authorized(struct http_message *hm, const char *path,
                               int is_directory, const char *domain,
                               const char *passwords_file,
                               int is_global_pass_file) {
      (void) hm;
      (void) path;
      (void) is_directory;
      (void) domain;
      (void) passwords_file;
      (void) is_global_pass_file;
      return 1;
   }
#endif
   
#ifndef MG_DISABLE_DIRECTORY_LISTING
   static size_t mg_url_encode(const char *src, size_t s_len, char *dst,
                               size_t dst_len) {
      static const char *dont_escape = "._-$,;~()/";
      static const char *hex = "0123456789abcdef";
      size_t i = 0, j = 0;
      
      for (i = j = 0; dst_len > 0 && i < s_len && j + 2 < dst_len - 1; i++, j++) {
         if (isalnum(*(const unsigned char *) (src + i)) ||
             strchr(dont_escape, *(const unsigned char *) (src + i)) != NULL) {
            dst[j] = src[i];
         } else if (j + 3 < dst_len) {
            dst[j] = '%';
            dst[j + 1] = hex[(*(const unsigned char *) (src + i)) >> 4];
            dst[j + 2] = hex[(*(const unsigned char *) (src + i)) & 0xf];
            j += 2;
         }
      }
      
      dst[j] = '\0';
      return j;
   }
   
   static void mg_escape(const char *src, char *dst, size_t dst_len) {
      size_t n = 0;
      while (*src != '\0' && n + 5 < dst_len) {
         unsigned char ch = *(unsigned char *) src++;
         if (ch == '<') {
            n += snprintf(dst + n, dst_len - n, "%s", "&lt;");
         } else {
            dst[n++] = ch;
         }
      }
      dst[n] = '\0';
   }
   
   static void mg_print_dir_entry(struct mg_connection *nc, const char *file_name,
                                  cs_stat_t *stp) {
      char size[64], mod[64], href[MAX_PATH_SIZE * 3], path[MAX_PATH_SIZE];
      int64_t fsize = stp->st_size;
      int is_dir = S_ISDIR(stp->st_mode);
      const char *slash = is_dir ? "/" : "";
      
      if (is_dir) {
         snprintf(size, sizeof(size), "%s", "[DIRECTORY]");
      } else {
         /*
          * We use (double) cast below because MSVC 6 compiler cannot
          * convert unsigned __int64 to double.
          */
         if (fsize < 1024) {
            snprintf(size, sizeof(size), "%d", (int) fsize);
         } else if (fsize < 0x100000) {
            snprintf(size, sizeof(size), "%.1fk", (double) fsize / 1024.0);
         } else if (fsize < 0x40000000) {
            snprintf(size, sizeof(size), "%.1fM", (double) fsize / 1048576);
         } else {
            snprintf(size, sizeof(size), "%.1fG", (double) fsize / 1073741824);
         }
      }
      strftime(mod, sizeof(mod), "%d-%b-%Y %H:%M", localtime(&stp->st_mtime));
      mg_escape(file_name, path, sizeof(path));
      mg_url_encode(file_name, strlen(file_name), href, sizeof(href));
      mg_printf_http_chunk(nc,
                           "<tr><td><a href=\"%s%s\">%s%s</a></td>"
                           "<td>%s</td><td name=%" INT64_FMT ">%s</td></tr>\n",
                           href, slash, path, slash, mod, is_dir ? -1 : fsize,
                           size);
   }
   
   static void mg_scan_directory(struct mg_connection *nc, const char *dir,
                                 const struct mg_serve_http_opts *opts,
                                 void (*func)(struct mg_connection *, const char *,
                                              cs_stat_t *)) {
                                    char path[MAX_PATH_SIZE];
                                    cs_stat_t st;
                                    struct dirent *dp;
                                    DIR *dirp;
                                    
                                    DBG(("%p [%s]", nc, dir));
                                    if ((dirp = (opendir(dir))) != NULL) {
                                       while ((dp = readdir(dirp)) != NULL) {
                                          /* Do not show current dir and hidden files */
                                          if (mg_is_file_hidden((const char *) dp->d_name, opts, 1)) {
                                             continue;
                                          }
                                          snprintf(path, sizeof(path), "%s/%s", dir, dp->d_name);
                                          if (mg_stat(path, &st) == 0) {
                                             func(nc, (const char *) dp->d_name, &st);
                                          }
                                       }
                                       closedir(dirp);
                                    } else {
                                       DBG(("%p opendir(%s) -> %d", nc, dir, errno));
                                    }
                                 }
   
   static void mg_send_directory_listing(struct mg_connection *nc, const char *dir,
                                         struct http_message *hm,
                                         struct mg_serve_http_opts *opts) {
      static const char *sort_js_code =
      "<script>function srt(tb, col) {"
      "var tr = Array.prototype.slice.call(tb.rows, 0),"
      "tr = tr.sort(function (a, b) { var c1 = a.cells[col], c2 = b.cells[col],"
      "n1 = c1.getAttribute('name'), n2 = c2.getAttribute('name'), "
      "t1 = a.cells[2].getAttribute('name'), "
      "t2 = b.cells[2].getAttribute('name'); "
      "return t1 < 0 && t2 >= 0 ? -1 : t2 < 0 && t1 >= 0 ? 1 : "
      "n1 ? parseInt(n2) - parseInt(n1) : "
      "c1.textContent.trim().localeCompare(c2.textContent.trim()); });";
      static const char *sort_js_code2 =
      "for (var i = 0; i < tr.length; i++) tb.appendChild(tr[i]);}"
      "window.onload = function() { "
      "var tb = document.getElementById('tb');"
      "document.onclick = function(ev){ "
      "var c = ev.target.rel; if (c) srt(tb, c)}; srt(tb, 2); };</script>";
      
      mg_send_response_line(nc, 200, opts->extra_headers);
      mg_printf(nc, "%s: %s\r\n%s: %s\r\n\r\n", "Transfer-Encoding", "chunked",
                "Content-Type", "text/html; charset=utf-8");
      
      mg_printf_http_chunk(
                           nc,
                           "<html><head><title>Index of %.*s</title>%s%s"
                           "<style>th,td {text-align: left; padding-right: 1em; "
                           "font-family: monospace; }</style></head>\n"
                           "<body><h1>Index of %.*s</h1>\n<table cellpadding=0><thead>"
                           "<tr><th><a href=# rel=0>Name</a></th><th>"
                           "<a href=# rel=1>Modified</a</th>"
                           "<th><a href=# rel=2>Size</a></th></tr>"
                           "<tr><td colspan=3><hr></td></tr>\n"
                           "</thead>\n"
                           "<tbody id=tb>",
                           (int) hm->uri.len, hm->uri.p, sort_js_code, sort_js_code2,
                           (int) hm->uri.len, hm->uri.p);
      mg_scan_directory(nc, dir, opts, mg_print_dir_entry);
      mg_printf_http_chunk(nc,
                           "<tr><td colspan=3><hr></td></tr>\n"
                           "</tbody></table>\n"
                           "<address>%s</address>\n"
                           "</body></html>",
                           mg_version_header);
      mg_send_http_chunk(nc, "", 0);
      /* TODO(rojer): Remove when cesanta/dev/issues/197 is fixed. */
      nc->flags |= MG_F_SEND_AND_CLOSE;
   }
#endif /* MG_DISABLE_DIRECTORY_LISTING */
   
#ifndef MG_DISABLE_DAV
   static void mg_print_props(struct mg_connection *nc, const char *name,
                              cs_stat_t *stp) {
      char mtime[64], buf[MAX_PATH_SIZE * 3];
      time_t t = stp->st_mtime; /* store in local variable for NDK compile */
      mg_gmt_time_string(mtime, sizeof(mtime), &t);
      mg_url_encode(name, strlen(name), buf, sizeof(buf));
      mg_printf(nc,
                "<d:response>"
                "<d:href>%s</d:href>"
                "<d:propstat>"
                "<d:prop>"
                "<d:resourcetype>%s</d:resourcetype>"
                "<d:getcontentlength>%" INT64_FMT
                "</d:getcontentlength>"
                "<d:getlastmodified>%s</d:getlastmodified>"
                "</d:prop>"
                "<d:status>HTTP/1.1 200 OK</d:status>"
                "</d:propstat>"
                "</d:response>\n",
                buf, S_ISDIR(stp->st_mode) ? "<d:collection/>" : "",
                (int64_t) stp->st_size, mtime);
   }
   
   static void mg_handle_propfind(struct mg_connection *nc, const char *path,
                                  cs_stat_t *stp, struct http_message *hm,
                                  struct mg_serve_http_opts *opts) {
      static const char header[] =
      "HTTP/1.1 207 Multi-Status\r\n"
      "Connection: close\r\n"
      "Content-Type: text/xml; charset=utf-8\r\n\r\n"
      "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
      "<d:multistatus xmlns:d='DAV:'>\n";
      static const char footer[] = "</d:multistatus>\n";
      const struct mg_str *depth = mg_get_http_header(hm, "Depth");
      
      /* Print properties for the requested resource itself */
      if (S_ISDIR(stp->st_mode) &&
          strcmp(opts->enable_directory_listing, "yes") != 0) {
         mg_printf(nc, "%s", "HTTP/1.1 403 Directory Listing Denied\r\n\r\n");
      } else {
         char uri[MAX_PATH_SIZE];
         mg_send(nc, header, sizeof(header) - 1);
         snprintf(uri, sizeof(uri), "%.*s", (int) hm->uri.len, hm->uri.p);
         mg_print_props(nc, uri, stp);
         if (S_ISDIR(stp->st_mode) && (depth == NULL || mg_vcmp(depth, "0") != 0)) {
            mg_scan_directory(nc, path, opts, mg_print_props);
         }
         mg_send(nc, footer, sizeof(footer) - 1);
         nc->flags |= MG_F_SEND_AND_CLOSE;
      }
   }
   
#ifdef MG_ENABLE_FAKE_DAVLOCK
   /*
    * Windows explorer (probably there are another WebDav clients like it)
    * requires LOCK support in webdav. W/out this, it still works, but fails
    * to save file: shows error message and offers "Save As".
    * "Save as" works, but this message is very annoying.
    * This is fake lock, which doesn't lock something, just returns LOCK token,
    * UNLOCK always answers "OK".
    * With this fake LOCK Windows Explorer looks happy and saves file.
    * NOTE: that is not DAV LOCK imlementation, it is just a way to shut up
    * Windows native DAV client. This is why FAKE LOCK is not enabed by default
    */
   static void mg_handle_lock(struct mg_connection *nc, const char *path) {
      static const char *reply =
      "HTTP/1.1 207 Multi-Status\r\n"
      "Connection: close\r\n"
      "Content-Type: text/xml; charset=utf-8\r\n\r\n"
      "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
      "<d:multistatus xmlns:d='DAV:'>\n"
      "<D:lockdiscovery>\n"
      "<D:activelock>\n"
      "<D:locktoken>\n"
      "<D:href>\n"
      "opaquelocktoken:%s%u"
      "</D:href>"
      "</D:locktoken>"
      "</D:activelock>\n"
      "</D:lockdiscovery>"
      "</d:multistatus>\n";
      mg_printf(nc, reply, path, (unsigned int) time(NULL));
      nc->flags |= MG_F_SEND_AND_CLOSE;
   }
#endif
   
   static void mg_handle_mkcol(struct mg_connection *nc, const char *path,
                               struct http_message *hm) {
      int status_code = 500;
      if (hm->body.len != (size_t) ~0 && hm->body.len > 0) {
         status_code = 415;
      } else if (!mg_mkdir(path, 0755)) {
         status_code = 201;
      } else if (errno == EEXIST) {
         status_code = 405;
      } else if (errno == EACCES) {
         status_code = 403;
      } else if (errno == ENOENT) {
         status_code = 409;
      } else {
         status_code = 500;
      }
      mg_http_send_error(nc, status_code, NULL);
   }
   
   static int mg_remove_directory(const struct mg_serve_http_opts *opts,
                                  const char *dir) {
      char path[MAX_PATH_SIZE];
      struct dirent *dp;
      cs_stat_t st;
      DIR *dirp;
      
      if ((dirp = opendir(dir)) == NULL) return 0;
      
      while ((dp = readdir(dirp)) != NULL) {
         if (mg_is_file_hidden((const char *) dp->d_name, opts, 1)) {
            continue;
         }
         snprintf(path, sizeof(path), "%s%c%s", dir, '/', dp->d_name);
         mg_stat(path, &st);
         if (S_ISDIR(st.st_mode)) {
            mg_remove_directory(opts, path);
         } else {
            remove(path);
         }
      }
      closedir(dirp);
      rmdir(dir);
      
      return 1;
   }
   
   static void mg_handle_move(struct mg_connection *c,
                              const struct mg_serve_http_opts *opts,
                              const char *path, struct http_message *hm) {
      const struct mg_str *dest = mg_get_http_header(hm, "Destination");
      if (dest == NULL) {
         mg_http_send_error(c, 411, NULL);
      } else {
         const char *p = (char *) memchr(dest->p, '/', dest->len);
         if (p != NULL && p[1] == '/' &&
             (p = (char *) memchr(p + 2, '/', dest->p + dest->len - p)) != NULL) {
            char buf[MAX_PATH_SIZE];
            snprintf(buf, sizeof(buf), "%s%.*s", opts->dav_document_root,
                     (int) (dest->p + dest->len - p), p);
            if (rename(path, buf) == 0) {
               mg_http_send_error(c, 200, NULL);
            } else {
               mg_http_send_error(c, 418, NULL);
            }
         } else {
            mg_http_send_error(c, 500, NULL);
         }
      }
   }
   
   static void mg_handle_delete(struct mg_connection *nc,
                                const struct mg_serve_http_opts *opts,
                                const char *path) {
      cs_stat_t st;
      if (mg_stat(path, &st) != 0) {
         mg_http_send_error(nc, 404, NULL);
      } else if (S_ISDIR(st.st_mode)) {
         mg_remove_directory(opts, path);
         mg_http_send_error(nc, 204, NULL);
      } else if (remove(path) == 0) {
         mg_http_send_error(nc, 204, NULL);
      } else {
         mg_http_send_error(nc, 423, NULL);
      }
   }
   
   /* Return -1 on error, 1 on success. */
   static int mg_create_itermediate_directories(const char *path) {
      const char *s;
      
      /* Create intermediate directories if they do not exist */
      for (s = path + 1; *s != '\0'; s++) {
         if (*s == '/') {
            char buf[MAX_PATH_SIZE];
            cs_stat_t st;
            snprintf(buf, sizeof(buf), "%.*s", (int) (s - path), path);
            buf[sizeof(buf) - 1] = '\0';
            if (mg_stat(buf, &st) != 0 && mg_mkdir(buf, 0755) != 0) {
               return -1;
            }
         }
      }
      
      return 1;
   }
   
   static void mg_handle_put(struct mg_connection *nc, const char *path,
                             struct http_message *hm) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
      cs_stat_t st;
      const struct mg_str *cl_hdr = mg_get_http_header(hm, "Content-Length");
      int rc, status_code = mg_stat(path, &st) == 0 ? 200 : 201;
      
      mg_http_free_proto_data_file(&pd->file);
      if ((rc = mg_create_itermediate_directories(path)) == 0) {
         mg_printf(nc, "HTTP/1.1 %d OK\r\nContent-Length: 0\r\n\r\n", status_code);
      } else if (rc == -1) {
         mg_http_send_error(nc, 500, NULL);
      } else if (cl_hdr == NULL) {
         mg_http_send_error(nc, 411, NULL);
      } else if ((pd->file.fp = fopen(path, "w+b")) == NULL) {
         mg_http_send_error(nc, 500, NULL);
      } else {
         const struct mg_str *range_hdr = mg_get_http_header(hm, "Content-Range");
         int64_t r1 = 0, r2 = 0;
         pd->file.type = DATA_PUT;
         mg_set_close_on_exec(fileno(pd->file.fp));
         pd->file.cl = to64(cl_hdr->p);
         if (range_hdr != NULL &&
             mg_http_parse_range_header(range_hdr, &r1, &r2) > 0) {
            status_code = 206;
            fseeko(pd->file.fp, r1, SEEK_SET);
            pd->file.cl = r2 > r1 ? r2 - r1 + 1 : pd->file.cl - r1;
         }
         mg_printf(nc, "HTTP/1.1 %d OK\r\nContent-Length: 0\r\n\r\n", status_code);
         /* Remove HTTP request from the mbuf, leave only payload */
         mbuf_remove(&nc->recv_mbuf, hm->message.len - hm->body.len);
         mg_http_transfer_file_data(nc);
      }
   }
#endif /* MG_DISABLE_DAV */
   
   static int mg_is_dav_request(const struct mg_str *s) {
      static const char *methods[] = {"PUT", "DELETE", "MKCOL", "PROPFIND", "MOVE"
#ifdef MG_ENABLE_FAKE_DAVLOCK
         ,
         "LOCK", "UNLOCK"
#endif
      };
      size_t i;
      
      for (i = 0; i < ARRAY_SIZE(methods); i++) {
         if (mg_vcmp(s, methods[i]) == 0) {
            return 1;
         }
      }
      
      return 0;
   }
   
   /*
    * Given a directory path, find one of the files specified in the
    * comma-separated list of index files `list`.
    * First found index file wins. If an index file is found, then gets
    * appended to the `path`, stat-ed, and result of `stat()` passed to `stp`.
    * If index file is not found, then `path` and `stp` remain unchanged.
    */
   MG_INTERNAL void mg_find_index_file(const char *path, const char *list,
                                       char **index_file, cs_stat_t *stp) {
      struct mg_str vec;
      size_t path_len = strlen(path);
      int found = 0;
      *index_file = NULL;
      
      /* Traverse index files list. For each entry, append it to the given */
      /* path and see if the file exists. If it exists, break the loop */
      while ((list = mg_next_comma_list_entry(list, &vec, NULL)) != NULL) {
         cs_stat_t st;
         size_t len = path_len + 1 + vec.len + 1;
         *index_file = (char *) MG_REALLOC(*index_file, len);
         if (*index_file == NULL) break;
         snprintf(*index_file, len, "%s%c%.*s", path, DIRSEP, (int) vec.len, vec.p);
         
         /* Does it exist? Is it a file? */
         if (mg_stat(*index_file, &st) == 0 && S_ISREG(st.st_mode)) {
            /* Yes it does, break the loop */
            *stp = st;
            found = 1;
            break;
         }
      }
      if (!found) {
         MG_FREE(*index_file);
         *index_file = NULL;
      }
      DBG(("[%s] [%s]", path, (*index_file ? *index_file : "")));
   }
   
   static int mg_http_send_port_based_redirect(
                                               struct mg_connection *c, struct http_message *hm,
                                               const struct mg_serve_http_opts *opts) {
      const char *rewrites = opts->url_rewrites;
      struct mg_str a, b;
      char local_port[20] = {'%'};
      
      mg_conn_addr_to_str(c, local_port + 1, sizeof(local_port) - 1,
                          MG_SOCK_STRINGIFY_PORT);
      
      while ((rewrites = mg_next_comma_list_entry(rewrites, &a, &b)) != NULL) {
         if (mg_vcmp(&a, local_port) == 0) {
            mg_send_response_line(c, 301, NULL);
            mg_printf(c, "Content-Length: 0\r\nLocation: %.*s%.*s\r\n\r\n",
                      (int) b.len, b.p, (int) (hm->proto.p - hm->uri.p - 1),
                      hm->uri.p);
            return 1;
         }
      }
      
      return 0;
   }
   
   MG_INTERNAL int mg_uri_to_local_path(struct http_message *hm,
                                        const struct mg_serve_http_opts *opts,
                                        char **local_path,
                                        struct mg_str *remainder) {
      int ok = 1;
      const char *cp = hm->uri.p, *cp_end = hm->uri.p + hm->uri.len;
      struct mg_str root = {NULL, 0};
      const char *file_uri_start = cp;
      *local_path = NULL;
      remainder->p = NULL;
      remainder->len = 0;
      
      { /* 1. Determine which root to use. */
         const char *rewrites = opts->url_rewrites;
         struct mg_str *hh = mg_get_http_header(hm, "Host");
         struct mg_str a, b;
         /* Check rewrites first. */
         while ((rewrites = mg_next_comma_list_entry(rewrites, &a, &b)) != NULL) {
            if (a.len > 1 && a.p[0] == '@') {
               /* Host rewrite. */
               if (hh != NULL && hh->len == a.len - 1 &&
                   mg_ncasecmp(a.p + 1, hh->p, a.len - 1) == 0) {
                  root = b;
                  break;
               }
            } else {
               /* Regular rewrite, URI=directory */
               int match_len = mg_match_prefix_n(a, hm->uri);
               if (match_len > 0) {
                  file_uri_start = hm->uri.p + match_len;
                  if (*file_uri_start == '/' || file_uri_start == cp_end) {
                     /* Match ended at component boundary, ok. */
                  } else if (*(file_uri_start - 1) == '/') {
                     /* Pattern ends with '/', backtrack. */
                     file_uri_start--;
                  } else {
                     /* No match: must fall on the component boundary. */
                     continue;
                  }
                  root = b;
                  break;
               }
            }
         }
         /* If no rewrite rules matched, use DAV or regular document root. */
         if (root.p == NULL) {
#ifndef MG_DISABLE_DAV
            if (opts->dav_document_root != NULL && mg_is_dav_request(&hm->method)) {
               root.p = opts->dav_document_root;
               root.len = strlen(opts->dav_document_root);
            } else
#endif
               {
               root.p = opts->document_root;
               root.len = strlen(opts->document_root);
               }
         }
         assert(root.p != NULL && root.len > 0);
      }
      
      { /* 2. Find where in the canonical URI path the local path ends. */
         const char *u = file_uri_start + 1;
         char *lp = (char *) MG_MALLOC(root.len + hm->uri.len + 1);
         char *lp_end = lp + root.len + hm->uri.len + 1;
         char *p = lp, *ps;
         int exists = 1;
         if (lp == NULL) {
            ok = 0;
            goto out;
         }
         memcpy(p, root.p, root.len);
         p += root.len;
         if (*(p - 1) == DIRSEP) p--;
         *p = '\0';
         ps = p;
         
         /* Chop off URI path components one by one and build local path. */
         while (u <= cp_end) {
            const char *next = u;
            struct mg_str component;
            if (exists) {
               cs_stat_t st;
               exists = (mg_stat(lp, &st) == 0);
               if (exists && S_ISREG(st.st_mode)) {
                  /* We found the terminal, the rest of the URI (if any) is path_info.
                   */
                  if (*(u - 1) == '/') u--;
                  break;
               }
            }
            if (u >= cp_end) break;
            parse_uri_component((const char **) &next, cp_end, '/', &component);
            if (component.len > 0) {
               int len;
               memmove(p + 1, component.p, component.len);
               len = mg_url_decode(p + 1, component.len, p + 1, lp_end - p - 1, 0);
               if (len <= 0) {
                  ok = 0;
                  break;
               }
               component.p = p + 1;
               component.len = len;
               if (mg_vcmp(&component, ".") == 0) {
                  /* Yum. */
               } else if (mg_vcmp(&component, "..") == 0) {
                  while (p > ps && *p != DIRSEP) p--;
                  *p = '\0';
               } else {
                  size_t i;
#ifdef _WIN32
                  /* On Windows, make sure it's valid Unicode (no funny stuff). */
                  wchar_t buf[MG_MAX_PATH * 2];
                  if (to_wchar(component.p, buf, MG_MAX_PATH) == 0) {
                     DBG(("[%.*s] smells funny", (int) component.len, component.p));
                     ok = 0;
                     break;
                  }
#endif
                  *p++ = DIRSEP;
                  /* No NULs and DIRSEPs in the component (percent-encoded). */
                  for (i = 0; i < component.len; i++, p++) {
                     if (*p == '\0' || *p == DIRSEP
#ifdef _WIN32
                         /* On Windows, "/" is also accepted, so check for that too. */
                         ||
                         *p == '/'
#endif
                         ) {
                        ok = 0;
                        break;
                     }
                  }
               }
            }
            u = next;
         }
         if (ok) {
            *local_path = lp;
            remainder->p = u;
            remainder->len = cp_end - u;
         } else {
            MG_FREE(lp);
         }
      }
      
   out:
      DBG(("'%.*s' -> '%s' + '%.*s'", (int) hm->uri.len, hm->uri.p,
           *local_path ? *local_path : "", (int) remainder->len, remainder->p));
      return ok;
   }
   
#ifndef MG_DISABLE_CGI
#ifdef _WIN32
   struct mg_threadparam {
      sock_t s;
      HANDLE hPipe;
   };
   
   static int mg_wait_until_ready(sock_t sock, int for_read) {
      fd_set set;
      FD_ZERO(&set);
      FD_SET(sock, &set);
      return select(sock + 1, for_read ? &set : 0, for_read ? 0 : &set, 0, 0) == 1;
   }
   
   static void *mg_push_to_stdin(void *arg) {
      struct mg_threadparam *tp = (struct mg_threadparam *) arg;
      int n, sent, stop = 0;
      DWORD k;
      char buf[BUFSIZ];
      
      while (!stop && mg_wait_until_ready(tp->s, 1) &&
             (n = recv(tp->s, buf, sizeof(buf), 0)) > 0) {
         if (n == -1 && GetLastError() == WSAEWOULDBLOCK) continue;
         for (sent = 0; !stop && sent < n; sent += k) {
            if (!WriteFile(tp->hPipe, buf + sent, n - sent, &k, 0)) stop = 1;
         }
      }
      DBG(("%s", "FORWARED EVERYTHING TO CGI"));
      CloseHandle(tp->hPipe);
      MG_FREE(tp);
      _endthread();
      return NULL;
   }
   
   static void *mg_pull_from_stdout(void *arg) {
      struct mg_threadparam *tp = (struct mg_threadparam *) arg;
      int k = 0, stop = 0;
      DWORD n, sent;
      char buf[BUFSIZ];
      
      while (!stop && ReadFile(tp->hPipe, buf, sizeof(buf), &n, NULL)) {
         for (sent = 0; !stop && sent < n; sent += k) {
            if (mg_wait_until_ready(tp->s, 0) &&
                (k = send(tp->s, buf + sent, n - sent, 0)) <= 0)
               stop = 1;
         }
      }
      DBG(("%s", "EOF FROM CGI"));
      CloseHandle(tp->hPipe);
      shutdown(tp->s, 2);  // Without this, IO thread may get truncated data
      closesocket(tp->s);
      MG_FREE(tp);
      _endthread();
      return NULL;
   }
   
   static void mg_spawn_stdio_thread(sock_t sock, HANDLE hPipe,
                                     void *(*func)(void *)) {
      struct mg_threadparam *tp = (struct mg_threadparam *) MG_MALLOC(sizeof(*tp));
      if (tp != NULL) {
         tp->s = sock;
         tp->hPipe = hPipe;
         mg_start_thread(func, tp);
      }
   }
   
   static void mg_abs_path(const char *utf8_path, char *abs_path, size_t len) {
      wchar_t buf[MAX_PATH_SIZE], buf2[MAX_PATH_SIZE];
      to_wchar(utf8_path, buf, ARRAY_SIZE(buf));
      GetFullPathNameW(buf, ARRAY_SIZE(buf2), buf2, NULL);
      WideCharToMultiByte(CP_UTF8, 0, buf2, wcslen(buf2) + 1, abs_path, len, 0, 0);
   }
   
   static pid_t mg_start_process(const char *interp, const char *cmd,
                                 const char *env, const char *envp[],
                                 const char *dir, sock_t sock) {
      STARTUPINFOW si;
      PROCESS_INFORMATION pi;
      HANDLE a[2], b[2], me = GetCurrentProcess();
      wchar_t wcmd[MAX_PATH_SIZE], full_dir[MAX_PATH_SIZE];
      char buf[MAX_PATH_SIZE], buf2[MAX_PATH_SIZE], buf5[MAX_PATH_SIZE],
      buf4[MAX_PATH_SIZE], cmdline[MAX_PATH_SIZE];
      DWORD flags = DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS;
      FILE *fp;
      
      memset(&si, 0, sizeof(si));
      memset(&pi, 0, sizeof(pi));
      
      si.cb = sizeof(si);
      si.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
      si.wShowWindow = SW_HIDE;
      si.hStdError = GetStdHandle(STD_ERROR_HANDLE);
      
      CreatePipe(&a[0], &a[1], NULL, 0);
      CreatePipe(&b[0], &b[1], NULL, 0);
      DuplicateHandle(me, a[0], me, &si.hStdInput, 0, TRUE, flags);
      DuplicateHandle(me, b[1], me, &si.hStdOutput, 0, TRUE, flags);
      
      if (interp == NULL && (fp = fopen(cmd, "r")) != NULL) {
         buf[0] = buf[1] = '\0';
         fgets(buf, sizeof(buf), fp);
         buf[sizeof(buf) - 1] = '\0';
         if (buf[0] == '#' && buf[1] == '!') {
            interp = buf + 2;
            /* Trim leading spaces: https://github.com/cesanta/mongoose/issues/489 */
            while (*interp != '\0' && isspace(*(unsigned char *) interp)) {
               interp++;
            }
         }
         fclose(fp);
      }
      
      snprintf(buf, sizeof(buf), "%s/%s", dir, cmd);
      mg_abs_path(buf, buf2, ARRAY_SIZE(buf2));
      
      mg_abs_path(dir, buf5, ARRAY_SIZE(buf5));
      to_wchar(dir, full_dir, ARRAY_SIZE(full_dir));
      
      if (interp != NULL) {
         mg_abs_path(interp, buf4, ARRAY_SIZE(buf4));
         snprintf(cmdline, sizeof(cmdline), "%s \"%s\"", buf4, buf2);
      } else {
         snprintf(cmdline, sizeof(cmdline), "\"%s\"", buf2);
      }
      to_wchar(cmdline, wcmd, ARRAY_SIZE(wcmd));
      
      if (CreateProcessW(NULL, wcmd, NULL, NULL, TRUE, CREATE_NEW_PROCESS_GROUP,
                         (void *) env, full_dir, &si, &pi) != 0) {
         mg_spawn_stdio_thread(sock, a[1], mg_push_to_stdin);
         mg_spawn_stdio_thread(sock, b[0], mg_pull_from_stdout);
      } else {
         CloseHandle(a[1]);
         CloseHandle(b[0]);
         closesocket(sock);
      }
      DBG(("CGI command: [%ls] -> %p", wcmd, pi.hProcess));
      
      /* Not closing a[0] and b[1] because we've used DUPLICATE_CLOSE_SOURCE */
      CloseHandle(si.hStdOutput);
      CloseHandle(si.hStdInput);
      /* TODO(lsm): check if we need close process and thread handles too */
      /* CloseHandle(pi.hThread); */
      /* CloseHandle(pi.hProcess); */
      
      return pi.hProcess;
   }
#else
   static pid_t mg_start_process(const char *interp, const char *cmd,
                                 const char *env, const char *envp[],
                                 const char *dir, sock_t sock) {
      char buf[500];
      pid_t pid = fork();
      (void) env;
      
      if (pid == 0) {
         /*
          * In Linux `chdir` declared with `warn_unused_result` attribute
          * To shutup compiler we have yo use result in some way
          */
         int tmp = chdir(dir);
         (void) tmp;
         (void) dup2(sock, 0);
         (void) dup2(sock, 1);
         closesocket(sock);
         
         /*
          * After exec, all signal handlers are restored to their default values,
          * with one exception of SIGCHLD. According to POSIX.1-2001 and Linux's
          * implementation, SIGCHLD's handler will leave unchanged after exec
          * if it was set to be ignored. Restore it to default action.
          */
         signal(SIGCHLD, SIG_DFL);
         
         if (interp == NULL) {
            execle(cmd, cmd, (char *) 0, envp); /* (char *) 0 to squash warning */
         } else {
            execle(interp, interp, cmd, (char *) 0, envp);
         }
         snprintf(buf, sizeof(buf),
                  "Status: 500\r\n\r\n"
                  "500 Server Error: %s%s%s: %s",
                  interp == NULL ? "" : interp, interp == NULL ? "" : " ", cmd,
                  strerror(errno));
         send(1, buf, strlen(buf), 0);
         exit(EXIT_FAILURE); /* exec call failed */
      }
      
      return pid;
   }
#endif /* _WIN32 */
   
   /*
    * Append VARIABLE=VALUE\0 string to the buffer, and add a respective
    * pointer into the vars array.
    */
   static char *mg_addenv(struct mg_cgi_env_block *block, const char *fmt, ...) {
      int n, space;
      char *added = block->buf + block->len;
      va_list ap;
      
      /* Calculate how much space is left in the buffer */
      space = sizeof(block->buf) - (block->len + 2);
      if (space > 0) {
         /* Copy VARIABLE=VALUE\0 string into the free space */
         va_start(ap, fmt);
         n = vsnprintf(added, (size_t) space, fmt, ap);
         va_end(ap);
         
         /* Make sure we do not overflow buffer and the envp array */
         if (n > 0 && n + 1 < space &&
             block->nvars < (int) ARRAY_SIZE(block->vars) - 2) {
            /* Append a pointer to the added string into the envp array */
            block->vars[block->nvars++] = added;
            /* Bump up used length counter. Include \0 terminator */
            block->len += n + 1;
         }
      }
      
      return added;
   }
   
   static void mg_addenv2(struct mg_cgi_env_block *blk, const char *name) {
      const char *s;
      if ((s = getenv(name)) != NULL) mg_addenv(blk, "%s=%s", name, s);
   }
   
   static void mg_prepare_cgi_environment(struct mg_connection *nc,
                                          const char *prog,
                                          const struct mg_str *path_info,
                                          const struct http_message *hm,
                                          const struct mg_serve_http_opts *opts,
                                          struct mg_cgi_env_block *blk) {
      const char *s;
      struct mg_str *h;
      char *p;
      size_t i;
      char buf[100];
      
      blk->len = blk->nvars = 0;
      blk->nc = nc;
      
      if ((s = getenv("SERVER_NAME")) != NULL) {
         mg_addenv(blk, "SERVER_NAME=%s", s);
      } else {
         mg_sock_to_str(nc->sock, buf, sizeof(buf), 3);
         mg_addenv(blk, "SERVER_NAME=%s", buf);
      }
      mg_addenv(blk, "SERVER_ROOT=%s", opts->document_root);
      mg_addenv(blk, "DOCUMENT_ROOT=%s", opts->document_root);
      mg_addenv(blk, "SERVER_SOFTWARE=%s/%s", "Mongoose", MG_VERSION);
      
      /* Prepare the environment block */
      mg_addenv(blk, "%s", "GATEWAY_INTERFACE=CGI/1.1");
      mg_addenv(blk, "%s", "SERVER_PROTOCOL=HTTP/1.1");
      mg_addenv(blk, "%s", "REDIRECT_STATUS=200"); /* For PHP */
      
      mg_addenv(blk, "REQUEST_METHOD=%.*s", (int) hm->method.len, hm->method.p);
      
      mg_addenv(blk, "REQUEST_URI=%.*s%s%.*s", (int) hm->uri.len, hm->uri.p,
                hm->query_string.len == 0 ? "" : "?", (int) hm->query_string.len,
                hm->query_string.p);
      
      mg_conn_addr_to_str(nc, buf, sizeof(buf),
                          MG_SOCK_STRINGIFY_REMOTE | MG_SOCK_STRINGIFY_IP);
      mg_addenv(blk, "REMOTE_ADDR=%s", buf);
      mg_conn_addr_to_str(nc, buf, sizeof(buf), MG_SOCK_STRINGIFY_PORT);
      mg_addenv(blk, "SERVER_PORT=%s", buf);
      
      s = hm->uri.p + hm->uri.len - path_info->len - 1;
      if (*s == '/') {
         const char *base_name = strrchr(prog, DIRSEP);
         mg_addenv(blk, "SCRIPT_NAME=%.*s/%s", (int) (s - hm->uri.p), hm->uri.p,
                   (base_name != NULL ? base_name + 1 : prog));
      } else {
         mg_addenv(blk, "SCRIPT_NAME=%.*s", (int) (s - hm->uri.p + 1), hm->uri.p);
      }
      mg_addenv(blk, "SCRIPT_FILENAME=%s", prog);
      
      if (path_info != NULL && path_info->len > 0) {
         mg_addenv(blk, "PATH_INFO=%.*s", (int) path_info->len, path_info->p);
         /* Not really translated... */
         mg_addenv(blk, "PATH_TRANSLATED=%.*s", (int) path_info->len, path_info->p);
      }
      
      mg_addenv(blk, "HTTPS=%s", nc->ssl != NULL ? "on" : "off");
      
      if ((h = mg_get_http_header((struct http_message *) hm, "Content-Type")) !=
          NULL) {
         mg_addenv(blk, "CONTENT_TYPE=%.*s", (int) h->len, h->p);
      }
      
      if (hm->query_string.len > 0) {
         mg_addenv(blk, "QUERY_STRING=%.*s", (int) hm->query_string.len,
                   hm->query_string.p);
      }
      
      if ((h = mg_get_http_header((struct http_message *) hm, "Content-Length")) !=
          NULL) {
         mg_addenv(blk, "CONTENT_LENGTH=%.*s", (int) h->len, h->p);
      }
      
      mg_addenv2(blk, "PATH");
      mg_addenv2(blk, "TMP");
      mg_addenv2(blk, "TEMP");
      mg_addenv2(blk, "TMPDIR");
      mg_addenv2(blk, "PERLLIB");
      mg_addenv2(blk, MG_ENV_EXPORT_TO_CGI);
      
#if defined(_WIN32)
      mg_addenv2(blk, "COMSPEC");
      mg_addenv2(blk, "SYSTEMROOT");
      mg_addenv2(blk, "SystemDrive");
      mg_addenv2(blk, "ProgramFiles");
      mg_addenv2(blk, "ProgramFiles(x86)");
      mg_addenv2(blk, "CommonProgramFiles(x86)");
#else
      mg_addenv2(blk, "LD_LIBRARY_PATH");
#endif /* _WIN32 */
      
      /* Add all headers as HTTP_* variables */
      for (i = 0; hm->header_names[i].len > 0; i++) {
         p = mg_addenv(blk, "HTTP_%.*s=%.*s", (int) hm->header_names[i].len,
                       hm->header_names[i].p, (int) hm->header_values[i].len,
                       hm->header_values[i].p);
         
         /* Convert variable name into uppercase, and change - to _ */
         for (; *p != '=' && *p != '\0'; p++) {
            if (*p == '-') *p = '_';
            *p = (char) toupper(*(unsigned char *) p);
         }
      }
      
      blk->vars[blk->nvars++] = NULL;
      blk->buf[blk->len++] = '\0';
   }
   
   static void mg_cgi_ev_handler(struct mg_connection *cgi_nc, int ev,
                                 void *ev_data) {
      struct mg_connection *nc = (struct mg_connection *) cgi_nc->user_data;
      (void) ev_data;
      
      if (nc == NULL) return;
      
      switch (ev) {
         case MG_EV_RECV:
            /*
             * CGI script does not output reply line, like "HTTP/1.1 CODE XXXXX\n"
             * It outputs headers, then body. Headers might include "Status"
             * header, which changes CODE, and it might include "Location" header
             * which changes CODE to 302.
             *
             * Therefore we do not send the output from the CGI script to the user
             * until all CGI headers are received.
             *
             * Here we parse the output from the CGI script, and if all headers has
             * been received, send appropriate reply line, and forward all
             * received headers to the client.
             */
            if (nc->flags & MG_F_USER_1) {
               struct mbuf *io = &cgi_nc->recv_mbuf;
               int len = mg_http_get_request_len(io->buf, io->len);
               
               if (len == 0) break;
               if (len < 0 || io->len > MG_MAX_HTTP_REQUEST_SIZE) {
                  cgi_nc->flags |= MG_F_CLOSE_IMMEDIATELY;
                  mg_http_send_error(nc, 500, "Bad headers");
               } else {
                  struct http_message hm;
                  struct mg_str *h;
                  mg_http_parse_headers(io->buf, io->buf + io->len, io->len, &hm);
                  if (mg_get_http_header(&hm, "Location") != NULL) {
                     mg_printf(nc, "%s", "HTTP/1.1 302 Moved\r\n");
                  } else if ((h = mg_get_http_header(&hm, "Status")) != NULL) {
                     mg_printf(nc, "HTTP/1.1 %.*s\r\n", (int) h->len, h->p);
                  } else {
                     mg_printf(nc, "%s", "HTTP/1.1 200 OK\r\n");
                  }
               }
               nc->flags &= ~MG_F_USER_1;
            }
            if (!(nc->flags & MG_F_USER_1)) {
               mg_forward(cgi_nc, nc);
            }
            break;
         case MG_EV_CLOSE:
            mg_http_free_proto_data_cgi(&mg_http_get_proto_data(cgi_nc)->cgi);
            nc->flags |= MG_F_SEND_AND_CLOSE;
            break;
      }
   }
   
   static void mg_handle_cgi(struct mg_connection *nc, const char *prog,
                             const struct mg_str *path_info,
                             const struct http_message *hm,
                             const struct mg_serve_http_opts *opts) {
      struct mg_cgi_env_block blk;
      char dir[MAX_PATH_SIZE];
      const char *p;
      sock_t fds[2];
      
      DBG(("%p [%s]", nc, prog));
      mg_prepare_cgi_environment(nc, prog, path_info, hm, opts, &blk);
      /*
       * CGI must be executed in its own directory. 'dir' must point to the
       * directory containing executable program, 'p' must point to the
       * executable program name relative to 'dir'.
       */
      if ((p = strrchr(prog, DIRSEP)) == NULL) {
         snprintf(dir, sizeof(dir), "%s", ".");
      } else {
         snprintf(dir, sizeof(dir), "%.*s", (int) (p - prog), prog);
         prog = p + 1;
      }
      
      /*
       * Try to create socketpair in a loop until success. mg_socketpair()
       * can be interrupted by a signal and fail.
       * TODO(lsm): use sigaction to restart interrupted syscall
       */
      do {
         mg_socketpair(fds, SOCK_STREAM);
      } while (fds[0] == INVALID_SOCKET);
      
      if (mg_start_process(opts->cgi_interpreter, prog, blk.buf, blk.vars, dir,
                           fds[1]) != 0) {
         size_t n = nc->recv_mbuf.len - (hm->message.len - hm->body.len);
         struct mg_connection *cgi_nc =
         mg_add_sock(nc->mgr, fds[0], mg_cgi_ev_handler);
         struct mg_http_proto_data *cgi_pd = mg_http_get_proto_data(cgi_nc);
         cgi_pd->cgi.cgi_nc = cgi_nc;
         cgi_pd->cgi.cgi_nc->user_data = nc;
         nc->flags |= MG_F_USER_1;
         /* Push POST data to the CGI */
         if (n > 0 && n < nc->recv_mbuf.len) {
            mg_send(cgi_pd->cgi.cgi_nc, hm->body.p, n);
         }
         mbuf_remove(&nc->recv_mbuf, nc->recv_mbuf.len);
      } else {
         closesocket(fds[0]);
         mg_http_send_error(nc, 500, "CGI failure");
      }
      
#ifndef _WIN32
      closesocket(fds[1]); /* On Windows, CGI stdio thread closes that socket */
#endif
   }
#endif
   
   static int mg_get_month_index(const char *s) {
      static const char *month_names[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
      size_t i;
      
      for (i = 0; i < ARRAY_SIZE(month_names); i++)
         if (!strcmp(s, month_names[i])) return (int) i;
      
      return -1;
   }
   
   static int mg_num_leap_years(int year) {
      return year / 4 - year / 100 + year / 400;
   }
   
   /* Parse UTC date-time string, and return the corresponding time_t value. */
   MG_INTERNAL time_t mg_parse_date_string(const char *datetime) {
      static const unsigned short days_before_month[] = {
         0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
      char month_str[32];
      int second, minute, hour, day, month, year, leap_days, days;
      time_t result = (time_t) 0;
      
      if (((sscanf(datetime, "%d/%3s/%d %d:%d:%d", &day, month_str, &year, &hour,
                   &minute, &second) == 6) ||
           (sscanf(datetime, "%d %3s %d %d:%d:%d", &day, month_str, &year, &hour,
                   &minute, &second) == 6) ||
           (sscanf(datetime, "%*3s, %d %3s %d %d:%d:%d", &day, month_str, &year,
                   &hour, &minute, &second) == 6) ||
           (sscanf(datetime, "%d-%3s-%d %d:%d:%d", &day, month_str, &year, &hour,
                   &minute, &second) == 6)) &&
          year > 1970 && (month = mg_get_month_index(month_str)) != -1) {
         leap_days = mg_num_leap_years(year) - mg_num_leap_years(1970);
         year -= 1970;
         days = year * 365 + days_before_month[month] + (day - 1) + leap_days;
         result = days * 24 * 3600 + hour * 3600 + minute * 60 + second;
      }
      
      return result;
   }
   
   MG_INTERNAL int mg_is_not_modified(struct http_message *hm, cs_stat_t *st) {
      struct mg_str *hdr;
      if ((hdr = mg_get_http_header(hm, "If-None-Match")) != NULL) {
         char etag[64];
         mg_http_construct_etag(etag, sizeof(etag), st);
         return mg_vcasecmp(hdr, etag) == 0;
      } else if ((hdr = mg_get_http_header(hm, "If-Modified-Since")) != NULL) {
         return st->st_mtime <= mg_parse_date_string(hdr->p);
      } else {
         return 0;
      }
   }
   
   static void mg_http_send_digest_auth_request(struct mg_connection *c,
                                                const char *domain) {
      mg_printf(c,
                "HTTP/1.1 401 Unauthorized\r\n"
                "WWW-Authenticate: Digest qop=\"auth\", "
                "realm=\"%s\", nonce=\"%lu\"\r\n"
                "Content-Length: 0\r\n\r\n",
                domain, (unsigned long) time(NULL));
   }
   
   static void mg_http_send_options(struct mg_connection *nc) {
      mg_printf(nc, "%s",
                "HTTP/1.1 200 OK\r\nAllow: GET, POST, HEAD, CONNECT, OPTIONS"
#ifndef MG_DISABLE_DAV
                ", MKCOL, PUT, DELETE, PROPFIND, MOVE\r\nDAV: 1,2"
#endif
                "\r\n\r\n");
      nc->flags |= MG_F_SEND_AND_CLOSE;
   }
   
   static int mg_is_creation_request(const struct http_message *hm) {
      return mg_vcmp(&hm->method, "MKCOL") == 0 || mg_vcmp(&hm->method, "PUT") == 0;
   }
   
   MG_INTERNAL void mg_send_http_file(struct mg_connection *nc, char *path,
                                      const struct mg_str *path_info,
                                      struct http_message *hm,
                                      struct mg_serve_http_opts *opts) {
      int exists, is_directory, is_dav = mg_is_dav_request(&hm->method);
      int is_cgi;
      char *index_file = NULL;
      cs_stat_t st;
      
      exists = (mg_stat(path, &st) == 0);
      is_directory = exists && S_ISDIR(st.st_mode);
      
      if (is_directory)
         mg_find_index_file(path, opts->index_files, &index_file, &st);
      
      is_cgi =
      (mg_match_prefix(opts->cgi_file_pattern, strlen(opts->cgi_file_pattern),
                       index_file ? index_file : path) > 0);
      
      DBG(("%p %.*s [%s] exists=%d is_dir=%d is_dav=%d is_cgi=%d index=%s", nc,
           (int) hm->method.len, hm->method.p, path, exists, is_directory, is_dav,
           is_cgi, index_file ? index_file : ""));
      
      if (is_directory && hm->uri.p[hm->uri.len - 1] != '/' && !is_dav) {
         mg_printf(nc,
                   "HTTP/1.1 301 Moved\r\nLocation: %.*s/\r\n"
                   "Content-Length: 0\r\n\r\n",
                   (int) hm->uri.len, hm->uri.p);
         MG_FREE(index_file);
         return;
      }
      
      /* If we have path_info, the only way to handle it is CGI. */
      if (path_info->len > 0 && !is_cgi) {
         mg_http_send_error(nc, 501, NULL);
         MG_FREE(index_file);
         return;
      }
      
      if (is_dav && opts->dav_document_root == NULL) {
         mg_http_send_error(nc, 501, NULL);
      } else if (!mg_is_authorized(hm, path, is_directory, opts->auth_domain,
                                   opts->global_auth_file, 1) ||
                 !mg_is_authorized(hm, path, is_directory, opts->auth_domain,
                                   opts->per_directory_auth_file, 0)) {
                    mg_http_send_digest_auth_request(nc, opts->auth_domain);
                 } else if (is_cgi) {
#if !defined(MG_DISABLE_CGI)
                    mg_handle_cgi(nc, index_file ? index_file : path, path_info, hm, opts);
#else
                    mg_http_send_error(nc, 501, NULL);
#endif /* MG_DISABLE_CGI */
                 } else if ((!exists ||
                             mg_is_file_hidden(path, opts, 0 /* specials are ok */)) &&
                            !mg_is_creation_request(hm)) {
                    mg_http_send_error(nc, 404, NULL);
#ifndef MG_DISABLE_DAV
                 } else if (!mg_vcmp(&hm->method, "PROPFIND")) {
                    mg_handle_propfind(nc, path, &st, hm, opts);
#ifndef MG_DISABLE_DAV_AUTH
                 } else if (is_dav &&
                            (opts->dav_auth_file == NULL ||
                             (strcmp(opts->dav_auth_file, "-") != 0 &&
                              !mg_is_authorized(hm, path, is_directory, opts->auth_domain,
                                                opts->dav_auth_file, 1)))) {
                                 mg_http_send_digest_auth_request(nc, opts->auth_domain);
#endif
                              } else if (!mg_vcmp(&hm->method, "MKCOL")) {
                                 mg_handle_mkcol(nc, path, hm);
                              } else if (!mg_vcmp(&hm->method, "DELETE")) {
                                 mg_handle_delete(nc, opts, path);
                              } else if (!mg_vcmp(&hm->method, "PUT")) {
                                 mg_handle_put(nc, path, hm);
                              } else if (!mg_vcmp(&hm->method, "MOVE")) {
                                 mg_handle_move(nc, opts, path, hm);
#ifdef MG_ENABLE_FAKE_DAVLOCK
                              } else if (!mg_vcmp(&hm->method, "LOCK")) {
                                 mg_handle_lock(nc, path);
#endif
#endif
                              } else if (!mg_vcmp(&hm->method, "OPTIONS")) {
                                 mg_http_send_options(nc);
                              } else if (is_directory && index_file == NULL) {
#ifndef MG_DISABLE_DIRECTORY_LISTING
                                 if (strcmp(opts->enable_directory_listing, "yes") == 0) {
                                    mg_send_directory_listing(nc, path, hm, opts);
                                 } else {
                                    mg_http_send_error(nc, 403, NULL);
                                 }
#else
                                 mg_http_send_error(nc, 501, NULL);
#endif
                              } else if (mg_is_not_modified(hm, &st)) {
                                 mg_http_send_error(nc, 304, "Not Modified");
                              } else {
                                 mg_http_send_file2(nc, index_file ? index_file : path, &st, hm, opts);
                              }
      MG_FREE(index_file);
   }
   
   void mg_serve_http(struct mg_connection *nc, struct http_message *hm,
                      struct mg_serve_http_opts opts) {
      char *path = NULL;
      struct mg_str *hdr, path_info;
      uint32_t remote_ip = ntohl(*(uint32_t *) &nc->sa.sin.sin_addr);
      
      if (mg_check_ip_acl(opts.ip_acl, remote_ip) != 1) {
         /* Not allowed to connect */
         mg_http_send_error(nc, 403, NULL);
         nc->flags |= MG_F_SEND_AND_CLOSE;
         return;
      }
      
      if (mg_http_send_port_based_redirect(nc, hm, &opts)) {
         return;
      }
      
      if (opts.document_root == NULL) {
         opts.document_root = ".";
      }
      if (opts.per_directory_auth_file == NULL) {
         opts.per_directory_auth_file = ".htpasswd";
      }
      if (opts.enable_directory_listing == NULL) {
         opts.enable_directory_listing = "yes";
      }
      if (opts.cgi_file_pattern == NULL) {
         opts.cgi_file_pattern = "**.cgi$|**.php$";
      }
      if (opts.ssi_pattern == NULL) {
         opts.ssi_pattern = "**.shtml$|**.shtm$";
      }
      if (opts.index_files == NULL) {
         opts.index_files = "index.html,index.htm,index.shtml,index.cgi,index.php";
      }
      /* Normalize path - resolve "." and ".." (in-place). */
      if (!mg_normalize_uri_path(&hm->uri, &hm->uri)) {
         mg_http_send_error(nc, 400, NULL);
         return;
      }
      if (mg_uri_to_local_path(hm, &opts, &path, &path_info) == 0) {
         mg_http_send_error(nc, 404, NULL);
         return;
      }
      mg_send_http_file(nc, path, &path_info, hm, &opts);
      
      MG_FREE(path);
      path = NULL;
      
      /* Close connection for non-keep-alive requests */
      if (mg_vcmp(&hm->proto, "HTTP/1.1") != 0 ||
          ((hdr = mg_get_http_header(hm, "Connection")) != NULL &&
           mg_vcmp(hdr, "keep-alive") != 0)) {
#if 0
             nc->flags |= MG_F_SEND_AND_CLOSE;
#endif
          }
   }
   
#endif /* MG_DISABLE_FILESYSTEM */
   
   /* returns 0 on success, -1 on error */
   static int mg_http_common_url_parse(const char *url, const char *schema,
                                       const char *schema_tls, int *use_ssl,
                                       char **addr, int *port_i,
                                       const char **path) {
      int addr_len = 0;
      
      if (memcmp(url, schema, strlen(schema)) == 0) {
         url += strlen(schema);
      } else if (memcmp(url, schema_tls, strlen(schema_tls)) == 0) {
         url += strlen(schema_tls);
         *use_ssl = 1;
#ifndef MG_ENABLE_SSL
         return -1; /* SSL is not enabled, cannot do HTTPS URLs */
#endif
      }
      
      while (*url != '\0') {
         *addr = (char *) MG_REALLOC(*addr, addr_len + 5 /* space for port too. */);
         if (*addr == NULL) {
            DBG(("OOM"));
            return -1;
         }
         if (*url == '/') {
            break;
         }
         if (*url == ':') *port_i = addr_len;
         (*addr)[addr_len++] = *url;
         (*addr)[addr_len] = '\0';
         url++;
      }
      if (addr_len == 0) goto cleanup;
      if (*port_i < 0) {
         *port_i = addr_len;
         strcpy(*addr + *port_i, *use_ssl ? ":443" : ":80");
      } else {
         *port_i = -1;
      }
      
      if (*path == NULL) *path = url;
      
      if (**path == '\0') *path = "/";
      
      DBG(("%s %s", *addr, *path));
      
      return 0;
      
   cleanup:
      MG_FREE(*addr);
      return -1;
   }
   
   struct mg_connection *mg_connect_http_base(
                                              struct mg_mgr *mgr, mg_event_handler_t ev_handler,
                                              struct mg_connect_opts opts, const char *schema, const char *schema_ssl,
                                              const char *url, const char **path, char **addr) {
      struct mg_connection *nc = NULL;
      int port_i = -1;
      int use_ssl = 0;
      
      if (mg_http_common_url_parse(url, schema, schema_ssl, &use_ssl, addr, &port_i,
                                   path) < 0) {
         return NULL;
      }
      
#ifndef MG_ENABLE_SSL
      if (use_ssl) {
         MG_SET_PTRPTR(opts.error_string, "ssl is disabled");
         MG_FREE(addr);
         return NULL;
      }
#endif
      
      if ((nc = mg_connect_opt(mgr, *addr, ev_handler, opts)) != NULL) {
#ifdef MG_ENABLE_SSL
         if (use_ssl && nc->ssl_ctx == NULL) {
            /*
             * Schema requires SSL, but no SSL parameters were provided in
             * opts. In order to maintain backward compatibility, use
             * NULL, NULL
             */
            mg_set_ssl(nc, NULL, NULL);
         }
#endif
         mg_set_protocol_http_websocket(nc);
         
         /* If the port was addred by us, restore the original host. */
         if (port_i >= 0) (*addr)[port_i] = '\0';
      }
      
      return nc;
   }
   
   struct mg_connection *mg_connect_http_opt(struct mg_mgr *mgr,
                                             mg_event_handler_t ev_handler,
                                             struct mg_connect_opts opts,
                                             const char *url,
                                             const char *extra_headers,
                                             const char *post_data) {
      char *addr = NULL;
      const char *path = NULL;
      struct mg_connection *nc = mg_connect_http_base(
                                                      mgr, ev_handler, opts, "http://", "https://", url, &path, &addr);
      
      if (nc == NULL) {
         return NULL;
      }
      
      mg_printf(nc, "%s %s HTTP/1.1\r\nHost: %s\r\nContent-Length: %" SIZE_T_FMT
                "\r\n%s\r\n%s",
                post_data == NULL ? "GET" : "POST", path, addr,
                post_data == NULL ? 0 : strlen(post_data),
                extra_headers == NULL ? "" : extra_headers,
                post_data == NULL ? "" : post_data);
      
      MG_FREE(addr);
      return nc;
   }
   
   struct mg_connection *mg_connect_http(struct mg_mgr *mgr,
                                         mg_event_handler_t ev_handler,
                                         const char *url,
                                         const char *extra_headers,
                                         const char *post_data) {
      struct mg_connect_opts opts;
      memset(&opts, 0, sizeof(opts));
      return mg_connect_http_opt(mgr, ev_handler, opts, url, extra_headers,
                                 post_data);
   }
   
   struct mg_connection *mg_connect_ws_opt(struct mg_mgr *mgr,
                                           mg_event_handler_t ev_handler,
                                           struct mg_connect_opts opts,
                                           const char *url, const char *protocol,
                                           const char *extra_headers) {
      char *addr = NULL;
      const char *path = NULL;
      struct mg_connection *nc = mg_connect_http_base(
                                                      mgr, ev_handler, opts, "ws://", "wss://", url, &path, &addr);
      
      if (nc == NULL) {
         return NULL;
      }
      
      mg_send_websocket_handshake2(nc, path, addr, protocol, extra_headers);
      
      MG_FREE(addr);
      return nc;
   }
   
   struct mg_connection *mg_connect_ws(struct mg_mgr *mgr,
                                       mg_event_handler_t ev_handler,
                                       const char *url, const char *protocol,
                                       const char *extra_headers) {
      struct mg_connect_opts opts;
      memset(&opts, 0, sizeof(opts));
      return mg_connect_ws_opt(mgr, ev_handler, opts, url, protocol, extra_headers);
   }
   
   size_t mg_parse_multipart(const char *buf, size_t buf_len, char *var_name,
                             size_t var_name_len, char *file_name,
                             size_t file_name_len, const char **data,
                             size_t *data_len) {
      static const char cd[] = "Content-Disposition: ";
      size_t hl, bl, n, ll, pos, cdl = sizeof(cd) - 1;
      
      if (buf == NULL || buf_len <= 0) return 0;
      if ((hl = mg_http_get_request_len(buf, buf_len)) <= 0) return 0;
      if (buf[0] != '-' || buf[1] != '-' || buf[2] == '\n') return 0;
      
      /* Get boundary length */
      bl = mg_get_line_len(buf, buf_len);
      
      /* Loop through headers, fetch variable name and file name */
      var_name[0] = file_name[0] = '\0';
      for (n = bl; (ll = mg_get_line_len(buf + n, hl - n)) > 0; n += ll) {
         if (mg_ncasecmp(cd, buf + n, cdl) == 0) {
            struct mg_str header;
            header.p = buf + n + cdl;
            header.len = ll - (cdl + 2);
            mg_http_parse_header(&header, "name", var_name, var_name_len);
            mg_http_parse_header(&header, "filename", file_name, file_name_len);
         }
      }
      
      /* Scan through the body, search for terminating boundary */
      for (pos = hl; pos + (bl - 2) < buf_len; pos++) {
         if (buf[pos] == '-' && !memcmp(buf, &buf[pos], bl - 2)) {
            if (data_len != NULL) *data_len = (pos - 2) - hl;
            if (data != NULL) *data = buf + hl;
            return pos;
         }
      }
      
      return 0;
   }
   
   void mg_register_http_endpoint(struct mg_connection *nc, const char *uri_path,
                                  mg_event_handler_t handler) {
      struct mg_http_proto_data *pd = mg_http_get_proto_data(nc);
      struct mg_http_endpoint *new_ep =
      (struct mg_http_endpoint *) calloc(1, sizeof(*new_ep));
      new_ep->name = strdup(uri_path);
      new_ep->name_len = strlen(new_ep->name);
      new_ep->handler = handler;
      new_ep->next = pd->endpoints;
      pd->endpoints = new_ep;
   }
   
#endif /* MG_DISABLE_HTTP */
#ifdef MG_MODULE_LINES
#line 1 "./src/util.c"
#endif
   /*
    * Copyright (c) 2014 Cesanta Software Limited
    * All rights reserved
    */
   
   /* Amalgamated: #include "common/base64.h" */
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/util.h" */
   
   const char *mg_skip(const char *s, const char *end, const char *delims,
                       struct mg_str *v) {
      v->p = s;
      while (s < end && strchr(delims, *(unsigned char *) s) == NULL) s++;
      v->len = s - v->p;
      while (s < end && strchr(delims, *(unsigned char *) s) != NULL) s++;
      return s;
   }
   
   static int lowercase(const char *s) {
      return tolower(*(const unsigned char *) s);
   }
   
   int mg_ncasecmp(const char *s1, const char *s2, size_t len) {
      int diff = 0;
      
      if (len > 0) do {
         diff = lowercase(s1++) - lowercase(s2++);
      } while (diff == 0 && s1[-1] != '\0' && --len > 0);
      
      return diff;
   }
   
   int mg_casecmp(const char *s1, const char *s2) {
      return mg_ncasecmp(s1, s2, (size_t) ~0);
   }
   
   int mg_vcasecmp(const struct mg_str *str1, const char *str2) {
      size_t n2 = strlen(str2), n1 = str1->len;
      int r = mg_ncasecmp(str1->p, str2, (n1 < n2) ? n1 : n2);
      if (r == 0) {
         return n1 - n2;
      }
      return r;
   }
   
   int mg_vcmp(const struct mg_str *str1, const char *str2) {
      size_t n2 = strlen(str2), n1 = str1->len;
      int r = memcmp(str1->p, str2, (n1 < n2) ? n1 : n2);
      if (r == 0) {
         return n1 - n2;
      }
      return r;
   }
   
#ifndef MG_DISABLE_FILESYSTEM
   int mg_stat(const char *path, cs_stat_t *st) {
#ifdef _WIN32
      wchar_t wpath[MAX_PATH_SIZE];
      to_wchar(path, wpath, ARRAY_SIZE(wpath));
      DBG(("[%ls] -> %d", wpath, _wstati64(wpath, st)));
      return _wstati64(wpath, (struct _stati64 *) st);
#else
      return stat(path, st);
#endif
   }
   
   FILE *mg_fopen(const char *path, const char *mode) {
#ifdef _WIN32
      wchar_t wpath[MAX_PATH_SIZE], wmode[10];
      to_wchar(path, wpath, ARRAY_SIZE(wpath));
      to_wchar(mode, wmode, ARRAY_SIZE(wmode));
      return _wfopen(wpath, wmode);
#else
      return fopen(path, mode);
#endif
   }
   
   int mg_open(const char *path, int flag, int mode) { /* LCOV_EXCL_LINE */
#ifdef _WIN32
      wchar_t wpath[MAX_PATH_SIZE];
      to_wchar(path, wpath, ARRAY_SIZE(wpath));
      return _wopen(wpath, flag, mode);
#else
      return open(path, flag, mode); /* LCOV_EXCL_LINE */
#endif
   }
#endif
   
   void mg_base64_encode(const unsigned char *src, int src_len, char *dst) {
      cs_base64_encode(src, src_len, dst);
   }
   
   int mg_base64_decode(const unsigned char *s, int len, char *dst) {
      return cs_base64_decode(s, len, dst);
   }
   
#ifdef MG_ENABLE_THREADS
   void *mg_start_thread(void *(*f)(void *), void *p) {
#ifdef _WIN32
      return (void *) _beginthread((void(__cdecl *) (void *) ) f, 0, p);
#else
      pthread_t thread_id = (pthread_t) 0;
      pthread_attr_t attr;
      
      (void) pthread_attr_init(&attr);
      (void) pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
      
#if defined(MG_STACK_SIZE) && MG_STACK_SIZE > 1
      (void) pthread_attr_setstacksize(&attr, MG_STACK_SIZE);
#endif
      
      pthread_create(&thread_id, &attr, f, p);
      pthread_attr_destroy(&attr);
      
      return (void *) thread_id;
#endif
   }
#endif /* MG_ENABLE_THREADS */
   
   /* Set close-on-exec bit for a given socket. */
   void mg_set_close_on_exec(sock_t sock) {
#ifdef _WIN32
      (void) SetHandleInformation((HANDLE) sock, HANDLE_FLAG_INHERIT, 0);
#elif defined(__unix__)
      fcntl(sock, F_SETFD, FD_CLOEXEC);
#else
      (void) sock;
#endif
   }
   
   void mg_sock_addr_to_str(const union socket_address *sa, char *buf, size_t len,
                            int flags) {
      int is_v6;
      if (buf == NULL || len <= 0) return;
      buf[0] = '\0';
#if defined(MG_ENABLE_IPV6)
      is_v6 = sa->sa.sa_family == AF_INET6;
#else
      is_v6 = 0;
#endif
      if (flags & MG_SOCK_STRINGIFY_IP) {
#if defined(MG_ENABLE_IPV6)
         const void *addr = NULL;
         char *start = buf;
         socklen_t capacity = len;
         if (!is_v6) {
            addr = &sa->sin.sin_addr;
         } else {
            addr = (void *) &sa->sin6.sin6_addr;
            if (flags & MG_SOCK_STRINGIFY_PORT) {
               *buf = '[';
               start++;
               capacity--;
            }
         }
         if (inet_ntop(sa->sa.sa_family, addr, start, capacity) == NULL) {
            *buf = '\0';
         }
#elif defined(_WIN32) || defined(MG_LWIP)
         /* Only Windoze Vista (and newer) have inet_ntop() */
         strncpy(buf, inet_ntoa(sa->sin.sin_addr), len);
#else
         inet_ntop(AF_INET, (void *) &sa->sin.sin_addr, buf, len);
#endif
      }
      if (flags & MG_SOCK_STRINGIFY_PORT) {
         int port = ntohs(sa->sin.sin_port);
         if (flags & MG_SOCK_STRINGIFY_IP) {
            snprintf(buf + strlen(buf), len - (strlen(buf) + 1), "%s:%d",
                     (is_v6 ? "]" : ""), port);
         } else {
            snprintf(buf, len, "%d", port);
         }
      }
   }
   
   void mg_conn_addr_to_str(struct mg_connection *nc, char *buf, size_t len,
                            int flags) {
      union socket_address sa;
      memset(&sa, 0, sizeof(sa));
      mg_if_get_conn_addr(nc, flags & MG_SOCK_STRINGIFY_REMOTE, &sa);
      mg_sock_addr_to_str(&sa, buf, len, flags);
   }
   
#ifndef MG_DISABLE_HEXDUMP
   int mg_hexdump(const void *buf, int len, char *dst, int dst_len) {
      const unsigned char *p = (const unsigned char *) buf;
      char ascii[17] = "";
      int i, idx, n = 0;
      
      for (i = 0; i < len; i++) {
         idx = i % 16;
         if (idx == 0) {
            if (i > 0) n += snprintf(dst + n, dst_len - n, "  %s\n", ascii);
            n += snprintf(dst + n, dst_len - n, "%04x ", i);
         }
         n += snprintf(dst + n, dst_len - n, " %02x", p[i]);
         ascii[idx] = p[i] < 0x20 || p[i] > 0x7e ? '.' : p[i];
         ascii[idx + 1] = '\0';
      }
      
      while (i++ % 16) n += snprintf(dst + n, dst_len - n, "%s", "   ");
      n += snprintf(dst + n, dst_len - n, "  %s\n\n", ascii);
      
      return n;
   }
#endif
   
   int mg_avprintf(char **buf, size_t size, const char *fmt, va_list ap) {
      va_list ap_copy;
      int len;
      
      va_copy(ap_copy, ap);
      len = vsnprintf(*buf, size, fmt, ap_copy);
      va_end(ap_copy);
      
      if (len < 0) {
         /* eCos and Windows are not standard-compliant and return -1 when
          * the buffer is too small. Keep allocating larger buffers until we
          * succeed or out of memory. */
         *buf = NULL; /* LCOV_EXCL_START */
         while (len < 0) {
            MG_FREE(*buf);
            size *= 2;
            if ((*buf = (char *) MG_MALLOC(size)) == NULL) break;
            va_copy(ap_copy, ap);
            len = vsnprintf(*buf, size, fmt, ap_copy);
            va_end(ap_copy);
         }
         /* LCOV_EXCL_STOP */
      } else if (len >= (int) size) {
         /* Standard-compliant code path. Allocate a buffer that is large enough. */
         if ((*buf = (char *) MG_MALLOC(len + 1)) == NULL) {
            len = -1; /* LCOV_EXCL_LINE */
         } else {    /* LCOV_EXCL_LINE */
            va_copy(ap_copy, ap);
            len = vsnprintf(*buf, len + 1, fmt, ap_copy);
            va_end(ap_copy);
         }
      }
      
      return len;
   }
   
#if !defined(MG_DISABLE_HEXDUMP)
   void mg_hexdump_connection(struct mg_connection *nc, const char *path,
                              const void *buf, int num_bytes, int ev) {
#if !defined(NO_LIBC) && !defined(MG_DISABLE_STDIO)
      FILE *fp = NULL;
      char *hexbuf, src[60], dst[60];
      int buf_size = num_bytes * 5 + 100;
      
      if (strcmp(path, "-") == 0) {
         fp = stdout;
      } else if (strcmp(path, "--") == 0) {
         fp = stderr;
#ifndef MG_DISABLE_FILESYSTEM
      } else {
         fp = fopen(path, "a");
#endif
      }
      if (fp == NULL) return;
      
      mg_conn_addr_to_str(nc, src, sizeof(src),
                          MG_SOCK_STRINGIFY_IP | MG_SOCK_STRINGIFY_PORT);
      mg_conn_addr_to_str(nc, dst, sizeof(dst), MG_SOCK_STRINGIFY_IP |
                          MG_SOCK_STRINGIFY_PORT |
                          MG_SOCK_STRINGIFY_REMOTE);
      fprintf(
              fp, "%lu %p %s %s %s %d\n", (unsigned long) time(NULL), (void *) nc, src,
              ev == MG_EV_RECV ? "<-" : ev == MG_EV_SEND
              ? "->"
              : ev == MG_EV_ACCEPT
              ? "<A"
              : ev == MG_EV_CONNECT ? "C>" : "XX",
              dst, num_bytes);
      if (num_bytes > 0 && (hexbuf = (char *) MG_MALLOC(buf_size)) != NULL) {
         mg_hexdump(buf, num_bytes, hexbuf, buf_size);
         fprintf(fp, "%s", hexbuf);
         MG_FREE(hexbuf);
      }
      if (fp != stdin && fp != stdout) fclose(fp);
#endif
   }
#endif
   
   int mg_is_big_endian(void) {
      static const int n = 1;
      /* TODO(mkm) use compiletime check with 4-byte char literal */
      return ((char *) &n)[0] == 0;
   }
   
   const char *mg_next_comma_list_entry(const char *list, struct mg_str *val,
                                        struct mg_str *eq_val) {
      if (list == NULL || *list == '\0') {
         /* End of the list */
         list = NULL;
      } else {
         val->p = list;
         if ((list = strchr(val->p, ',')) != NULL) {
            /* Comma found. Store length and shift the list ptr */
            val->len = list - val->p;
            list++;
         } else {
            /* This value is the last one */
            list = val->p + strlen(val->p);
            val->len = list - val->p;
         }
         
         if (eq_val != NULL) {
            /* Value has form "x=y", adjust pointers and lengths */
            /* so that val points to "x", and eq_val points to "y". */
            eq_val->len = 0;
            eq_val->p = (const char *) memchr(val->p, '=', val->len);
            if (eq_val->p != NULL) {
               eq_val->p++; /* Skip over '=' character */
               eq_val->len = val->p + val->len - eq_val->p;
               val->len = (eq_val->p - val->p) - 1;
            }
         }
      }
      
      return list;
   }
   
   int mg_match_prefix_n(const struct mg_str pattern, const struct mg_str str) {
      const char *or_str;
      size_t len, i = 0, j = 0;
      int res;
      
      if ((or_str = (const char *) memchr(pattern.p, '|', pattern.len)) != NULL) {
         struct mg_str pstr = {pattern.p, (size_t)(or_str - pattern.p)};
         res = mg_match_prefix_n(pstr, str);
         if (res > 0) return res;
         pstr.p = or_str + 1;
         pstr.len = (pattern.p + pattern.len) - (or_str + 1);
         return mg_match_prefix_n(pstr, str);
      }
      
      for (; i < pattern.len; i++, j++) {
         if (pattern.p[i] == '?' && j != str.len) {
            continue;
         } else if (pattern.p[i] == '$') {
            return j == str.len ? (int) j : -1;
         } else if (pattern.p[i] == '*') {
            i++;
            if (pattern.p[i] == '*') {
               i++;
               len = str.len - j;
            } else {
               len = 0;
               while (j + len != str.len && str.p[len] != '/') {
                  len++;
               }
            }
            if (i == pattern.len) {
               return j + len;
            }
            do {
               const struct mg_str pstr = {pattern.p + i, pattern.len - i};
               const struct mg_str sstr = {str.p + j + len, str.len - j - len};
               res = mg_match_prefix_n(pstr, sstr);
            } while (res == -1 && len-- > 0);
            return res == -1 ? -1 : (int) (j + res + len);
         } else if (lowercase(&pattern.p[i]) != lowercase(&str.p[j])) {
            return -1;
         }
      }
      return j;
   }
   
   int mg_match_prefix(const char *pattern, int pattern_len, const char *str) {
      const struct mg_str pstr = {pattern, (size_t) pattern_len};
      return mg_match_prefix_n(pstr, mg_mk_str(str));
   }
   
   struct mg_str mg_mk_str(const char *s) {
      struct mg_str ret = {s, 0};
      if (s != NULL) ret.len = strlen(s);
      return ret;
   }
#ifdef MG_MODULE_LINES
#line 1 "./src/json-rpc.c"
#endif
   /* Copyright (c) 2014 Cesanta Software Limited */
   /* All rights reserved */
   
#ifndef MG_DISABLE_JSON_RPC
   
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/json-rpc.h" */
   /* Amalgamated: #include "mongoose/deps/frozen/frozen.h" */
   
   int mg_rpc_create_reply(char *buf, int len, const struct mg_rpc_request *req,
                           const char *result_fmt, ...) {
      static const struct json_token null_tok = {"null", 4, 0, JSON_TYPE_NULL};
      const struct json_token *id = req->id == NULL ? &null_tok : req->id;
      va_list ap;
      int n = 0;
      
      n += json_emit(buf + n, len - n, "{s:s,s:", "jsonrpc", "2.0", "id");
      if (id->type == JSON_TYPE_STRING) {
         n += json_emit_quoted_str(buf + n, len - n, id->ptr, id->len);
      } else {
         n += json_emit_unquoted_str(buf + n, len - n, id->ptr, id->len);
      }
      n += json_emit(buf + n, len - n, ",s:", "result");
      
      va_start(ap, result_fmt);
      n += json_emit_va(buf + n, len - n, result_fmt, ap);
      va_end(ap);
      
      n += json_emit(buf + n, len - n, "}");
      
      return n;
   }
   
   int mg_rpc_create_request(char *buf, int len, const char *method,
                             const char *id, const char *params_fmt, ...) {
      va_list ap;
      int n = 0;
      
      n += json_emit(buf + n, len - n, "{s:s,s:s,s:s,s:", "jsonrpc", "2.0", "id",
                     id, "method", method, "params");
      va_start(ap, params_fmt);
      n += json_emit_va(buf + n, len - n, params_fmt, ap);
      va_end(ap);
      
      n += json_emit(buf + n, len - n, "}");
      
      return n;
   }
   
   int mg_rpc_create_error(char *buf, int len, struct mg_rpc_request *req,
                           int code, const char *message, const char *fmt, ...) {
      va_list ap;
      int n = 0;
      
      n += json_emit(buf + n, len - n, "{s:s,s:V,s:{s:i,s:s,s:", "jsonrpc", "2.0",
                     "id", req->id == NULL ? "null" : req->id->ptr,
                     req->id == NULL ? 4 : req->id->len, "error", "code",
                     (long) code, "message", message, "data");
      va_start(ap, fmt);
      n += json_emit_va(buf + n, len - n, fmt, ap);
      va_end(ap);
      
      n += json_emit(buf + n, len - n, "}}");
      
      return n;
   }
   
   int mg_rpc_create_std_error(char *buf, int len, struct mg_rpc_request *req,
                               int code) {
      const char *message = NULL;
      
      switch (code) {
         case JSON_RPC_PARSE_ERROR:
            message = "parse error";
            break;
         case JSON_RPC_INVALID_REQUEST_ERROR:
            message = "invalid request";
            break;
         case JSON_RPC_METHOD_NOT_FOUND_ERROR:
            message = "method not found";
            break;
         case JSON_RPC_INVALID_PARAMS_ERROR:
            message = "invalid parameters";
            break;
         case JSON_RPC_SERVER_ERROR:
            message = "server error";
            break;
         default:
            message = "unspecified error";
            break;
      }
      
      return mg_rpc_create_error(buf, len, req, code, message, "N");
   }
   
   int mg_rpc_dispatch(const char *buf, int len, char *dst, int dst_len,
                       const char **methods, mg_rpc_handler_t *handlers) {
      struct json_token tokens[200];
      struct mg_rpc_request req;
      int i, n;
      
      memset(&req, 0, sizeof(req));
      n = parse_json(buf, len, tokens, sizeof(tokens) / sizeof(tokens[0]));
      if (n <= 0) {
         int err_code = (n == JSON_STRING_INVALID) ? JSON_RPC_PARSE_ERROR
         : JSON_RPC_SERVER_ERROR;
         return mg_rpc_create_std_error(dst, dst_len, &req, err_code);
      }
      
      req.message = tokens;
      req.id = find_json_token(tokens, "id");
      req.method = find_json_token(tokens, "method");
      req.params = find_json_token(tokens, "params");
      
      if (req.id == NULL || req.method == NULL) {
         return mg_rpc_create_std_error(dst, dst_len, &req,
                                        JSON_RPC_INVALID_REQUEST_ERROR);
      }
      
      for (i = 0; methods[i] != NULL; i++) {
         int mlen = strlen(methods[i]);
         if (mlen == req.method->len &&
             memcmp(methods[i], req.method->ptr, mlen) == 0)
            break;
      }
      
      if (methods[i] == NULL) {
         return mg_rpc_create_std_error(dst, dst_len, &req,
                                        JSON_RPC_METHOD_NOT_FOUND_ERROR);
      }
      
      return handlers[i](dst, dst_len, &req);
   }
   
   int mg_rpc_parse_reply(const char *buf, int len, struct json_token *toks,
                          int max_toks, struct mg_rpc_reply *rep,
                          struct mg_rpc_error *er) {
      int n = parse_json(buf, len, toks, max_toks);
      
      memset(rep, 0, sizeof(*rep));
      memset(er, 0, sizeof(*er));
      
      if (n > 0) {
         if ((rep->result = find_json_token(toks, "result")) != NULL) {
            rep->message = toks;
            rep->id = find_json_token(toks, "id");
         } else {
            er->message = toks;
            er->id = find_json_token(toks, "id");
            er->error_code = find_json_token(toks, "error.code");
            er->error_message = find_json_token(toks, "error.message");
            er->error_data = find_json_token(toks, "error.data");
         }
      }
      return n;
   }
   
#endif /* MG_DISABLE_JSON_RPC */
#ifdef MG_MODULE_LINES
#line 1 "./src/mqtt.c"
#endif
   /*
    * Copyright (c) 2014 Cesanta Software Limited
    * All rights reserved
    */
   
#ifndef MG_DISABLE_MQTT
   
#include <string.h>
   
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/mqtt.h" */
   
   MG_INTERNAL int parse_mqtt(struct mbuf *io, struct mg_mqtt_message *mm) {
      uint8_t header;
      int cmd;
      size_t len = 0;
      int var_len = 0;
      char *vlen = &io->buf[1];
      
      if (io->len < 2) return -1;
      
      header = io->buf[0];
      cmd = header >> 4;
      
      /* decode mqtt variable length */
      do {
         len += (*vlen & 127) << 7 * (vlen - &io->buf[1]);
      } while ((*vlen++ & 128) != 0 && ((size_t)(vlen - io->buf) <= io->len));
      
      if (len != 0 && io->len < (size_t)(len - 1)) return -1;
      
      mbuf_remove(io, 1 + (vlen - &io->buf[1]));
      mm->cmd = cmd;
      mm->qos = MG_MQTT_GET_QOS(header);
      
      switch (cmd) {
         case MG_MQTT_CMD_CONNECT:
            /* TODO(mkm): parse keepalive and will */
            break;
         case MG_MQTT_CMD_CONNACK:
            mm->connack_ret_code = io->buf[1];
            var_len = 2;
            break;
         case MG_MQTT_CMD_PUBACK:
         case MG_MQTT_CMD_PUBREC:
         case MG_MQTT_CMD_PUBREL:
         case MG_MQTT_CMD_PUBCOMP:
         case MG_MQTT_CMD_SUBACK:
            mm->message_id = ntohs(*(uint16_t *) io->buf);
            var_len = 2;
            break;
         case MG_MQTT_CMD_PUBLISH: {
            uint16_t topic_len = ntohs(*(uint16_t *) io->buf);
            mm->topic = (char *) MG_MALLOC(topic_len + 1);
            mm->topic[topic_len] = 0;
            strncpy(mm->topic, io->buf + 2, topic_len);
            var_len = topic_len + 2;
            
            if (MG_MQTT_GET_QOS(header) > 0) {
               mm->message_id = ntohs(*(uint16_t *) io->buf);
               var_len += 2;
            }
         } break;
         case MG_MQTT_CMD_SUBSCRIBE:
            /*
             * topic expressions are left in the payload and can be parsed with
             * `mg_mqtt_next_subscribe_topic`
             */
            mm->message_id = ntohs(*(uint16_t *) io->buf);
            var_len = 2;
            break;
         default:
            /* Unhandled command */
            break;
      }
      
      mbuf_remove(io, var_len);
      return len - var_len;
   }
   
   static void mqtt_handler(struct mg_connection *nc, int ev, void *ev_data) {
      int len;
      struct mbuf *io = &nc->recv_mbuf;
      struct mg_mqtt_message mm;
      memset(&mm, 0, sizeof(mm));
      
      nc->handler(nc, ev, ev_data);
      
      switch (ev) {
         case MG_EV_RECV:
            len = parse_mqtt(io, &mm);
            if (len == -1) break; /* not fully buffered */
            mm.payload.p = io->buf;
            mm.payload.len = len;
            
            nc->handler(nc, MG_MQTT_EVENT_BASE + mm.cmd, &mm);
            
            if (mm.topic) {
               MG_FREE(mm.topic);
            }
            mbuf_remove(io, mm.payload.len);
            break;
      }
   }
   
   void mg_set_protocol_mqtt(struct mg_connection *nc) {
      nc->proto_handler = mqtt_handler;
   }
   
   void mg_send_mqtt_handshake(struct mg_connection *nc, const char *client_id) {
      static struct mg_send_mqtt_handshake_opts opts;
      mg_send_mqtt_handshake_opt(nc, client_id, opts);
   }
   
   void mg_send_mqtt_handshake_opt(struct mg_connection *nc, const char *client_id,
                                   struct mg_send_mqtt_handshake_opts opts) {
      uint8_t header = MG_MQTT_CMD_CONNECT << 4;
      uint8_t rem_len;
      uint16_t keep_alive;
      uint16_t len;
      
      /*
       * 9: version_header(len, magic_string, version_number), 1: flags, 2:
       * keep-alive timer,
       * 2: client_identifier_len, n: client_id
       */
      rem_len = 9 + 1 + 2 + 2 + strlen(client_id);
      
      if (opts.user_name != NULL) {
         opts.flags |= MG_MQTT_HAS_USER_NAME;
         rem_len += strlen(opts.user_name) + 2;
      }
      if (opts.password != NULL) {
         opts.flags |= MG_MQTT_HAS_PASSWORD;
         rem_len += strlen(opts.password) + 2;
      }
      
      mg_send(nc, &header, 1);
      mg_send(nc, &rem_len, 1);
      mg_send(nc, "\00\06MQIsdp\03", 9);
      mg_send(nc, &opts.flags, 1);
      
      if (opts.keep_alive == 0) {
         opts.keep_alive = 60;
      }
      keep_alive = htons(opts.keep_alive);
      mg_send(nc, &keep_alive, 2);
      
      len = htons(strlen(client_id));
      mg_send(nc, &len, 2);
      mg_send(nc, client_id, strlen(client_id));
      
      if (opts.flags & MG_MQTT_HAS_USER_NAME) {
         len = htons(strlen(opts.user_name));
         mg_send(nc, &len, 2);
         mg_send(nc, opts.user_name, strlen(opts.user_name));
      }
      if (opts.flags & MG_MQTT_HAS_PASSWORD) {
         len = htons(strlen(opts.password));
         mg_send(nc, &len, 2);
         mg_send(nc, opts.password, strlen(opts.password));
      }
   }
   
   static void mg_mqtt_prepend_header(struct mg_connection *nc, uint8_t cmd,
                                      uint8_t flags, size_t len) {
      size_t off = nc->send_mbuf.len - len;
      uint8_t header = cmd << 4 | (uint8_t) flags;
      
      uint8_t buf[1 + sizeof(size_t)];
      uint8_t *vlen = &buf[1];
      
      assert(nc->send_mbuf.len >= len);
      
      buf[0] = header;
      
      /* mqtt variable length encoding */
      do {
         *vlen = len % 0x80;
         len /= 0x80;
         if (len > 0) *vlen |= 0x80;
         vlen++;
      } while (len > 0);
      
      mbuf_insert(&nc->send_mbuf, off, buf, vlen - buf);
   }
   
   void mg_mqtt_publish(struct mg_connection *nc, const char *topic,
                        uint16_t message_id, int flags, const void *data,
                        size_t len) {
      size_t old_len = nc->send_mbuf.len;
      
      uint16_t topic_len = htons(strlen(topic));
      uint16_t message_id_net = htons(message_id);
      
      mg_send(nc, &topic_len, 2);
      mg_send(nc, topic, strlen(topic));
      if (MG_MQTT_GET_QOS(flags) > 0) {
         mg_send(nc, &message_id_net, 2);
      }
      mg_send(nc, data, len);
      
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_PUBLISH, flags,
                             nc->send_mbuf.len - old_len);
   }
   
   void mg_mqtt_subscribe(struct mg_connection *nc,
                          const struct mg_mqtt_topic_expression *topics,
                          size_t topics_len, uint16_t message_id) {
      size_t old_len = nc->send_mbuf.len;
      
      uint16_t message_id_n = htons(message_id);
      size_t i;
      
      mg_send(nc, (char *) &message_id_n, 2);
      for (i = 0; i < topics_len; i++) {
         uint16_t topic_len_n = htons(strlen(topics[i].topic));
         mg_send(nc, &topic_len_n, 2);
         mg_send(nc, topics[i].topic, strlen(topics[i].topic));
         mg_send(nc, &topics[i].qos, 1);
      }
      
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_SUBSCRIBE, MG_MQTT_QOS(1),
                             nc->send_mbuf.len - old_len);
   }
   
   int mg_mqtt_next_subscribe_topic(struct mg_mqtt_message *msg,
                                    struct mg_str *topic, uint8_t *qos, int pos) {
      unsigned char *buf = (unsigned char *) msg->payload.p + pos;
      if ((size_t) pos >= msg->payload.len) {
         return -1;
      }
      
      topic->len = buf[0] << 8 | buf[1];
      topic->p = (char *) buf + 2;
      *qos = buf[2 + topic->len];
      return pos + 2 + topic->len + 1;
   }
   
   void mg_mqtt_unsubscribe(struct mg_connection *nc, char **topics,
                            size_t topics_len, uint16_t message_id) {
      size_t old_len = nc->send_mbuf.len;
      
      uint16_t message_id_n = htons(message_id);
      size_t i;
      
      mg_send(nc, (char *) &message_id_n, 2);
      for (i = 0; i < topics_len; i++) {
         uint16_t topic_len_n = htons(strlen(topics[i]));
         mg_send(nc, &topic_len_n, 2);
         mg_send(nc, topics[i], strlen(topics[i]));
      }
      
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_UNSUBSCRIBE, MG_MQTT_QOS(1),
                             nc->send_mbuf.len - old_len);
   }
   
   void mg_mqtt_connack(struct mg_connection *nc, uint8_t return_code) {
      uint8_t unused = 0;
      mg_send(nc, &unused, 1);
      mg_send(nc, &return_code, 1);
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_CONNACK, 0, 2);
   }
   
   /*
    * Sends a command which contains only a `message_id` and a QoS level of 1.
    *
    * Helper function.
    */
   static void mg_send_mqtt_short_command(struct mg_connection *nc, uint8_t cmd,
                                          uint16_t message_id) {
      uint16_t message_id_net = htons(message_id);
      mg_send(nc, &message_id_net, 2);
      mg_mqtt_prepend_header(nc, cmd, MG_MQTT_QOS(1), 2);
   }
   
   void mg_mqtt_puback(struct mg_connection *nc, uint16_t message_id) {
      mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBACK, message_id);
   }
   
   void mg_mqtt_pubrec(struct mg_connection *nc, uint16_t message_id) {
      mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBREC, message_id);
   }
   
   void mg_mqtt_pubrel(struct mg_connection *nc, uint16_t message_id) {
      mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBREL, message_id);
   }
   
   void mg_mqtt_pubcomp(struct mg_connection *nc, uint16_t message_id) {
      mg_send_mqtt_short_command(nc, MG_MQTT_CMD_PUBCOMP, message_id);
   }
   
   void mg_mqtt_suback(struct mg_connection *nc, uint8_t *qoss, size_t qoss_len,
                       uint16_t message_id) {
      size_t i;
      uint16_t message_id_net = htons(message_id);
      mg_send(nc, &message_id_net, 2);
      for (i = 0; i < qoss_len; i++) {
         mg_send(nc, &qoss[i], 1);
      }
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_SUBACK, MG_MQTT_QOS(1), 2 + qoss_len);
   }
   
   void mg_mqtt_unsuback(struct mg_connection *nc, uint16_t message_id) {
      mg_send_mqtt_short_command(nc, MG_MQTT_CMD_UNSUBACK, message_id);
   }
   
   void mg_mqtt_ping(struct mg_connection *nc) {
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_PINGREQ, 0, 0);
   }
   
   void mg_mqtt_pong(struct mg_connection *nc) {
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_PINGRESP, 0, 0);
   }
   
   void mg_mqtt_disconnect(struct mg_connection *nc) {
      mg_mqtt_prepend_header(nc, MG_MQTT_CMD_DISCONNECT, 0, 0);
   }
   
#endif /* MG_DISABLE_MQTT */
#ifdef MG_MODULE_LINES
#line 1 "./src/mqtt-broker.c"
#endif
   /*
    * Copyright (c) 2014 Cesanta Software Limited
    * All rights reserved
    */
   
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/mqtt-broker.h" */
   
#ifdef MG_ENABLE_MQTT_BROKER
   
   static void mg_mqtt_session_init(struct mg_mqtt_broker *brk,
                                    struct mg_mqtt_session *s,
                                    struct mg_connection *nc) {
      s->brk = brk;
      s->subscriptions = NULL;
      s->num_subscriptions = 0;
      s->nc = nc;
   }
   
   static void mg_mqtt_add_session(struct mg_mqtt_session *s) {
      s->next = s->brk->sessions;
      s->brk->sessions = s;
      s->prev = NULL;
      if (s->next != NULL) s->next->prev = s;
   }
   
   static void mg_mqtt_remove_session(struct mg_mqtt_session *s) {
      if (s->prev == NULL) s->brk->sessions = s->next;
      if (s->prev) s->prev->next = s->next;
      if (s->next) s->next->prev = s->prev;
   }
   
   static void mg_mqtt_destroy_session(struct mg_mqtt_session *s) {
      size_t i;
      for (i = 0; i < s->num_subscriptions; i++) {
         MG_FREE((void *) s->subscriptions[i].topic);
      }
      MG_FREE(s->subscriptions);
      MG_FREE(s);
   }
   
   static void mg_mqtt_close_session(struct mg_mqtt_session *s) {
      mg_mqtt_remove_session(s);
      mg_mqtt_destroy_session(s);
   }
   
   void mg_mqtt_broker_init(struct mg_mqtt_broker *brk, void *user_data) {
      brk->sessions = NULL;
      brk->user_data = user_data;
   }
   
   static void mg_mqtt_broker_handle_connect(struct mg_mqtt_broker *brk,
                                             struct mg_connection *nc) {
      struct mg_mqtt_session *s = (struct mg_mqtt_session *) malloc(sizeof *s);
      if (s == NULL) {
         /* LCOV_EXCL_START */
         mg_mqtt_connack(nc, MG_EV_MQTT_CONNACK_SERVER_UNAVAILABLE);
         return;
         /* LCOV_EXCL_STOP */
      }
      
      /* TODO(mkm): check header (magic and version) */
      
      mg_mqtt_session_init(brk, s, nc);
      s->user_data = nc->user_data;
      nc->user_data = s;
      mg_mqtt_add_session(s);
      
      mg_mqtt_connack(nc, MG_EV_MQTT_CONNACK_ACCEPTED);
   }
   
   static void mg_mqtt_broker_handle_subscribe(struct mg_connection *nc,
                                               struct mg_mqtt_message *msg) {
      struct mg_mqtt_session *ss = (struct mg_mqtt_session *) nc->user_data;
      uint8_t qoss[512];
      size_t qoss_len = 0;
      struct mg_str topic;
      uint8_t qos;
      int pos;
      struct mg_mqtt_topic_expression *te;
      
      for (pos = 0;
           (pos = mg_mqtt_next_subscribe_topic(msg, &topic, &qos, pos)) != -1;) {
         qoss[qoss_len++] = qos;
      }
      
      ss->subscriptions = (struct mg_mqtt_topic_expression *) realloc(
                                                                      ss->subscriptions, sizeof(*ss->subscriptions) * qoss_len);
      for (pos = 0;
           (pos = mg_mqtt_next_subscribe_topic(msg, &topic, &qos, pos)) != -1;
           ss->num_subscriptions++) {
         te = &ss->subscriptions[ss->num_subscriptions];
         te->topic = (char *) malloc(topic.len + 1);
         te->qos = qos;
         strncpy((char *) te->topic, topic.p, topic.len + 1);
      }
      
      mg_mqtt_suback(nc, qoss, qoss_len, msg->message_id);
   }
   
   /*
    * Matches a topic against a topic expression
    *
    * See http://goo.gl/iWk21X
    *
    * Returns 1 if it matches; 0 otherwise.
    */
   static int mg_mqtt_match_topic_expression(const char *exp, const char *topic) {
      /* TODO(mkm): implement real matching */
      int len = strlen(exp);
      if (strchr(exp, '#')) {
         len -= 2;
      }
      return strncmp(exp, topic, len) == 0;
   }
   
   static void mg_mqtt_broker_handle_publish(struct mg_mqtt_broker *brk,
                                             struct mg_mqtt_message *msg) {
      struct mg_mqtt_session *s;
      size_t i;
      
      for (s = mg_mqtt_next(brk, NULL); s != NULL; s = mg_mqtt_next(brk, s)) {
         for (i = 0; i < s->num_subscriptions; i++) {
            if (mg_mqtt_match_topic_expression(s->subscriptions[i].topic,
                                               msg->topic)) {
               mg_mqtt_publish(s->nc, msg->topic, 0, 0, msg->payload.p,
                               msg->payload.len);
               break;
            }
         }
      }
   }
   
   void mg_mqtt_broker(struct mg_connection *nc, int ev, void *data) {
      struct mg_mqtt_message *msg = (struct mg_mqtt_message *) data;
      struct mg_mqtt_broker *brk;
      
      if (nc->listener) {
         brk = (struct mg_mqtt_broker *) nc->listener->user_data;
      } else {
         brk = (struct mg_mqtt_broker *) nc->user_data;
      }
      
      switch (ev) {
         case MG_EV_ACCEPT:
            mg_set_protocol_mqtt(nc);
            break;
         case MG_EV_MQTT_CONNECT:
            mg_mqtt_broker_handle_connect(brk, nc);
            break;
         case MG_EV_MQTT_SUBSCRIBE:
            mg_mqtt_broker_handle_subscribe(nc, msg);
            break;
         case MG_EV_MQTT_PUBLISH:
            mg_mqtt_broker_handle_publish(brk, msg);
            break;
         case MG_EV_CLOSE:
            if (nc->listener) {
               mg_mqtt_close_session((struct mg_mqtt_session *) nc->user_data);
            }
            break;
      }
   }
   
   struct mg_mqtt_session *mg_mqtt_next(struct mg_mqtt_broker *brk,
                                        struct mg_mqtt_session *s) {
      return s == NULL ? brk->sessions : s->next;
   }
   
#endif /* MG_ENABLE_MQTT_BROKER */
#ifdef MG_MODULE_LINES
#line 1 "./src/dns.c"
#endif
   /*
    * Copyright (c) 2014 Cesanta Software Limited
    * All rights reserved
    */
   
#ifndef MG_DISABLE_DNS
   
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/dns.h" */
   
   static int mg_dns_tid = 0xa0;
   
   struct mg_dns_header {
      uint16_t transaction_id;
      uint16_t flags;
      uint16_t num_questions;
      uint16_t num_answers;
      uint16_t num_authority_prs;
      uint16_t num_other_prs;
   };
   
   struct mg_dns_resource_record *mg_dns_next_record(
                                                     struct mg_dns_message *msg, int query,
                                                     struct mg_dns_resource_record *prev) {
      struct mg_dns_resource_record *rr;
      
      for (rr = (prev == NULL ? msg->answers : prev + 1);
           rr - msg->answers < msg->num_answers; rr++) {
         if (rr->rtype == query) {
            return rr;
         }
      }
      return NULL;
   }
   
   int mg_dns_parse_record_data(struct mg_dns_message *msg,
                                struct mg_dns_resource_record *rr, void *data,
                                size_t data_len) {
      switch (rr->rtype) {
         case MG_DNS_A_RECORD:
            if (data_len < sizeof(struct in_addr)) {
               return -1;
            }
            if (rr->rdata.p + data_len > msg->pkt.p + msg->pkt.len) {
               return -1;
            }
            memcpy(data, rr->rdata.p, data_len);
            return 0;
#ifdef MG_ENABLE_IPV6
         case MG_DNS_AAAA_RECORD:
            if (data_len < sizeof(struct in6_addr)) {
               return -1; /* LCOV_EXCL_LINE */
            }
            memcpy(data, rr->rdata.p, data_len);
            return 0;
#endif
         case MG_DNS_CNAME_RECORD:
            mg_dns_uncompress_name(msg, &rr->rdata, (char *) data, data_len);
            return 0;
      }
      
      return -1;
   }
   
   int mg_dns_insert_header(struct mbuf *io, size_t pos,
                            struct mg_dns_message *msg) {
      struct mg_dns_header header;
      
      memset(&header, 0, sizeof(header));
      header.transaction_id = msg->transaction_id;
      header.flags = htons(msg->flags);
      header.num_questions = htons(msg->num_questions);
      header.num_answers = htons(msg->num_answers);
      
      return mbuf_insert(io, pos, &header, sizeof(header));
   }
   
   int mg_dns_copy_questions(struct mbuf *io, struct mg_dns_message *msg) {
      unsigned char *begin, *end;
      struct mg_dns_resource_record *last_q;
      if (msg->num_questions <= 0) return 0;
      begin = (unsigned char *) msg->pkt.p + sizeof(struct mg_dns_header);
      last_q = &msg->questions[msg->num_questions - 1];
      end = (unsigned char *) last_q->name.p + last_q->name.len + 4;
      return mbuf_append(io, begin, end - begin);
   }
   
   static int mg_dns_encode_name(struct mbuf *io, const char *name, size_t len) {
      const char *s;
      unsigned char n;
      size_t pos = io->len;
      
      do {
         if ((s = strchr(name, '.')) == NULL) {
            s = name + len;
         }
         
         if (s - name > 127) {
            return -1; /* TODO(mkm) cover */
         }
         n = s - name;           /* chunk length */
         mbuf_append(io, &n, 1); /* send length */
         mbuf_append(io, name, n);
         
         if (*s == '.') {
            n++;
         }
         
         name += n;
         len -= n;
      } while (*s != '\0');
      mbuf_append(io, "\0", 1); /* Mark end of host name */
      
      return io->len - pos;
   }
   
   int mg_dns_encode_record(struct mbuf *io, struct mg_dns_resource_record *rr,
                            const char *name, size_t nlen, const void *rdata,
                            size_t rlen) {
      size_t pos = io->len;
      uint16_t u16;
      uint32_t u32;
      
      if (rr->kind == MG_DNS_INVALID_RECORD) {
         return -1; /* LCOV_EXCL_LINE */
      }
      
      if (mg_dns_encode_name(io, name, nlen) == -1) {
         return -1;
      }
      
      u16 = htons(rr->rtype);
      mbuf_append(io, &u16, 2);
      u16 = htons(rr->rclass);
      mbuf_append(io, &u16, 2);
      
      if (rr->kind == MG_DNS_ANSWER) {
         u32 = htonl(rr->ttl);
         mbuf_append(io, &u32, 4);
         
         if (rr->rtype == MG_DNS_CNAME_RECORD) {
            int clen;
            /* fill size after encoding */
            size_t off = io->len;
            mbuf_append(io, &u16, 2);
            if ((clen = mg_dns_encode_name(io, (const char *) rdata, rlen)) == -1) {
               return -1;
            }
            u16 = clen;
            io->buf[off] = u16 >> 8;
            io->buf[off + 1] = u16 & 0xff;
         } else {
            u16 = htons(rlen);
            mbuf_append(io, &u16, 2);
            mbuf_append(io, rdata, rlen);
         }
      }
      
      return io->len - pos;
   }
   
   void mg_send_dns_query(struct mg_connection *nc, const char *name,
                          int query_type) {
      struct mg_dns_message *msg =
      (struct mg_dns_message *) MG_CALLOC(1, sizeof(*msg));
      struct mbuf pkt;
      struct mg_dns_resource_record *rr = &msg->questions[0];
      
      DBG(("%s %d", name, query_type));
      
      mbuf_init(&pkt, 64 /* Start small, it'll grow as needed. */);
      
      msg->transaction_id = ++mg_dns_tid;
      msg->flags = 0x100;
      msg->num_questions = 1;
      
      mg_dns_insert_header(&pkt, 0, msg);
      
      rr->rtype = query_type;
      rr->rclass = 1; /* Class: inet */
      rr->kind = MG_DNS_QUESTION;
      
      if (mg_dns_encode_record(&pkt, rr, name, strlen(name), NULL, 0) == -1) {
         /* TODO(mkm): return an error code */
         goto cleanup; /* LCOV_EXCL_LINE */
      }
      
      /* TCP DNS requires messages to be prefixed with len */
      if (!(nc->flags & MG_F_UDP)) {
         uint16_t len = htons(pkt.len);
         mbuf_insert(&pkt, 0, &len, 2);
      }
      
      mg_send(nc, pkt.buf, pkt.len);
      mbuf_free(&pkt);
      
   cleanup:
      MG_FREE(msg);
   }
   
   static unsigned char *mg_parse_dns_resource_record(
                                                      unsigned char *data, unsigned char *end, struct mg_dns_resource_record *rr,
                                                      int reply) {
      unsigned char *name = data;
      int chunk_len, data_len;
      
      while (data < end && (chunk_len = *data)) {
         if (((unsigned char *) data)[0] & 0xc0) {
            data += 1;
            break;
         }
         data += chunk_len + 1;
      }
      
      if (data > end - 5) {
         return NULL;
      }
      
      rr->name.p = (char *) name;
      rr->name.len = data - name + 1;
      data++;
      
      rr->rtype = data[0] << 8 | data[1];
      data += 2;
      
      rr->rclass = data[0] << 8 | data[1];
      data += 2;
      
      rr->kind = reply ? MG_DNS_ANSWER : MG_DNS_QUESTION;
      if (reply) {
         if (data >= end - 6) {
            return NULL;
         }
         
         rr->ttl = (uint32_t) data[0] << 24 | (uint32_t) data[1] << 16 |
         data[2] << 8 | data[3];
         data += 4;
         
         data_len = *data << 8 | *(data + 1);
         data += 2;
         
         rr->rdata.p = (char *) data;
         rr->rdata.len = data_len;
         data += data_len;
      }
      return data;
   }
   
   int mg_parse_dns(const char *buf, int len, struct mg_dns_message *msg) {
      struct mg_dns_header *header = (struct mg_dns_header *) buf;
      unsigned char *data = (unsigned char *) buf + sizeof(*header);
      unsigned char *end = (unsigned char *) buf + len;
      int i;
      
      memset(msg, 0, sizeof(*msg));
      msg->pkt.p = buf;
      msg->pkt.len = len;
      
      if (len < (int) sizeof(*header)) return -1;
      
      msg->transaction_id = header->transaction_id;
      msg->flags = ntohs(header->flags);
      msg->num_questions = ntohs(header->num_questions);
      if (msg->num_questions > (int) ARRAY_SIZE(msg->questions)) {
         msg->num_questions = (int) ARRAY_SIZE(msg->questions);
      }
      msg->num_answers = ntohs(header->num_answers);
      if (msg->num_answers > (int) ARRAY_SIZE(msg->answers)) {
         msg->num_answers = (int) ARRAY_SIZE(msg->answers);
      }
      
      for (i = 0; i < msg->num_questions; i++) {
         data = mg_parse_dns_resource_record(data, end, &msg->questions[i], 0);
         if (data == NULL) return -1;
      }
      
      for (i = 0; i < msg->num_answers; i++) {
         data = mg_parse_dns_resource_record(data, end, &msg->answers[i], 1);
         if (data == NULL) return -1;
      }
      
      return 0;
   }
   
   size_t mg_dns_uncompress_name(struct mg_dns_message *msg, struct mg_str *name,
                                 char *dst, int dst_len) {
      int chunk_len;
      char *old_dst = dst;
      const unsigned char *data = (unsigned char *) name->p;
      const unsigned char *end = (unsigned char *) msg->pkt.p + msg->pkt.len;
      
      if (data >= end) {
         return 0;
      }
      
      while ((chunk_len = *data++)) {
         int leeway = dst_len - (dst - old_dst);
         if (data >= end) {
            return 0;
         }
         
         if (chunk_len & 0xc0) {
            uint16_t off = (data[-1] & (~0xc0)) << 8 | data[0];
            if (off >= msg->pkt.len) {
               return 0;
            }
            data = (unsigned char *) msg->pkt.p + off;
            continue;
         }
         if (chunk_len > leeway) {
            chunk_len = leeway;
         }
         
         if (data + chunk_len >= end) {
            return 0;
         }
         
         memcpy(dst, data, chunk_len);
         data += chunk_len;
         dst += chunk_len;
         leeway -= chunk_len;
         if (leeway == 0) {
            return dst - old_dst;
         }
         *dst++ = '.';
      }
      
      if (dst != old_dst) {
         *--dst = 0;
      }
      return dst - old_dst;
   }
   
   static void dns_handler(struct mg_connection *nc, int ev, void *ev_data) {
      struct mbuf *io = &nc->recv_mbuf;
      struct mg_dns_message msg;
      
      /* Pass low-level events to the user handler */
      nc->handler(nc, ev, ev_data);
      
      switch (ev) {
         case MG_EV_RECV:
            if (!(nc->flags & MG_F_UDP)) {
               mbuf_remove(&nc->recv_mbuf, 2);
            }
            if (mg_parse_dns(nc->recv_mbuf.buf, nc->recv_mbuf.len, &msg) == -1) {
               /* reply + recursion allowed + format error */
               memset(&msg, 0, sizeof(msg));
               msg.flags = 0x8081;
               mg_dns_insert_header(io, 0, &msg);
               if (!(nc->flags & MG_F_UDP)) {
                  uint16_t len = htons(io->len);
                  mbuf_insert(io, 0, &len, 2);
               }
               mg_send(nc, io->buf, io->len);
            } else {
               /* Call user handler with parsed message */
               nc->handler(nc, MG_DNS_MESSAGE, &msg);
            }
            mbuf_remove(io, io->len);
            break;
      }
   }
   
   void mg_set_protocol_dns(struct mg_connection *nc) {
      nc->proto_handler = dns_handler;
   }
   
#endif /* MG_DISABLE_DNS */
#ifdef MG_MODULE_LINES
#line 1 "./src/dns-server.c"
#endif
   /*
    * Copyright (c) 2014 Cesanta Software Limited
    * All rights reserved
    */
   
#ifdef MG_ENABLE_DNS_SERVER
   
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/dns-server.h" */
   
   struct mg_dns_reply mg_dns_create_reply(struct mbuf *io,
                                           struct mg_dns_message *msg) {
      struct mg_dns_reply rep;
      rep.msg = msg;
      rep.io = io;
      rep.start = io->len;
      
      /* reply + recursion allowed */
      msg->flags |= 0x8080;
      mg_dns_copy_questions(io, msg);
      
      msg->num_answers = 0;
      return rep;
   }
   
   void mg_dns_send_reply(struct mg_connection *nc, struct mg_dns_reply *r) {
      size_t sent = r->io->len - r->start;
      mg_dns_insert_header(r->io, r->start, r->msg);
      if (!(nc->flags & MG_F_UDP)) {
         uint16_t len = htons(sent);
         mbuf_insert(r->io, r->start, &len, 2);
      }
      
      if (&nc->send_mbuf != r->io) {
         mg_send(nc, r->io->buf + r->start, r->io->len - r->start);
         r->io->len = r->start;
      }
   }
   
   int mg_dns_reply_record(struct mg_dns_reply *reply,
                           struct mg_dns_resource_record *question,
                           const char *name, int rtype, int ttl, const void *rdata,
                           size_t rdata_len) {
      struct mg_dns_message *msg = (struct mg_dns_message *) reply->msg;
      char rname[512];
      struct mg_dns_resource_record *ans = &msg->answers[msg->num_answers];
      if (msg->num_answers >= MG_MAX_DNS_ANSWERS) {
         return -1; /* LCOV_EXCL_LINE */
      }
      
      if (name == NULL) {
         name = rname;
         rname[511] = 0;
         mg_dns_uncompress_name(msg, &question->name, rname, sizeof(rname) - 1);
      }
      
      *ans = *question;
      ans->kind = MG_DNS_ANSWER;
      ans->rtype = rtype;
      ans->ttl = ttl;
      
      if (mg_dns_encode_record(reply->io, ans, name, strlen(name), rdata,
                               rdata_len) == -1) {
         return -1; /* LCOV_EXCL_LINE */
      };
      
      msg->num_answers++;
      return 0;
   }
   
#endif /* MG_ENABLE_DNS_SERVER */
#ifdef MG_MODULE_LINES
#line 1 "./src/resolv.c"
#endif
   /*
    * Copyright (c) 2014 Cesanta Software Limited
    * All rights reserved
    */
   
#ifndef MG_DISABLE_RESOLVER
   
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/resolv.h" */
   
#ifndef MG_DEFAULT_NAMESERVER
#define MG_DEFAULT_NAMESERVER "8.8.8.8"
#endif
   
   static const char *mg_default_dns_server = "udp://" MG_DEFAULT_NAMESERVER ":53";
   
   MG_INTERNAL char mg_dns_server[256];
   
   struct mg_resolve_async_request {
      char name[1024];
      int query;
      mg_resolve_callback_t callback;
      void *data;
      time_t timeout;
      int max_retries;
      enum mg_resolve_err err;
      
      /* state */
      time_t last_time;
      int retries;
   };
   
   /*
    * Find what nameserver to use.
    *
    * Return 0 if OK, -1 if error
    */
   static int mg_get_ip_address_of_nameserver(char *name, size_t name_len) {
      int ret = -1;
      
#ifdef _WIN32
      int i;
      LONG err;
      HKEY hKey, hSub;
      char subkey[512], value[128],
      *key = "SYSTEM\\ControlSet001\\Services\\Tcpip\\Parameters\\Interfaces";
      
      if ((err = RegOpenKeyA(HKEY_LOCAL_MACHINE, key, &hKey)) != ERROR_SUCCESS) {
         fprintf(stderr, "cannot open reg key %s: %d\n", key, err);
         ret = -1;
      } else {
         for (ret = -1, i = 0;
              RegEnumKeyA(hKey, i, subkey, sizeof(subkey)) == ERROR_SUCCESS; i++) {
            DWORD type, len = sizeof(value);
            if (RegOpenKeyA(hKey, subkey, &hSub) == ERROR_SUCCESS &&
                (RegQueryValueExA(hSub, "NameServer", 0, &type, (void *) value,
                                  &len) == ERROR_SUCCESS ||
                 RegQueryValueExA(hSub, "DhcpNameServer", 0, &type, (void *) value,
                                  &len) == ERROR_SUCCESS)) {
                    /*
                     * See https://github.com/cesanta/mongoose/issues/176
                     * The value taken from the registry can be empty, a single
                     * IP address, or multiple IP addresses separated by comma.
                     * If it's empty, check the next interface.
                     * If it's multiple IP addresses, take the first one.
                     */
                    char *comma = strchr(value, ',');
                    if (value[0] == '\0') {
                       continue;
                    }
                    if (comma != NULL) {
                       *comma = '\0';
                    }
                    snprintf(name, name_len, "udp://%s:53", value);
                    ret = 0;
                    RegCloseKey(hSub);
                    break;
                 }
         }
         RegCloseKey(hKey);
      }
#elif !defined(MG_DISABLE_FILESYSTEM)
      FILE *fp;
      char line[512];
      
      if ((fp = fopen("/etc/resolv.conf", "r")) == NULL) {
         ret = -1;
      } else {
         /* Try to figure out what nameserver to use */
         for (ret = -1; fgets(line, sizeof(line), fp) != NULL;) {
            char buf[256];
            if (sscanf(line, "nameserver %255[^\n\t #]s", buf) == 1) {
               snprintf(name, name_len, "udp://%s:53", buf);
               ret = 0;
               break;
            }
         }
         (void) fclose(fp);
      }
#else
      snprintf(name, name_len, "%s", mg_default_dns_server);
#endif /* _WIN32 */
      
      return ret;
   }
   
   int mg_resolve_from_hosts_file(const char *name, union socket_address *usa) {
#ifndef MG_DISABLE_FILESYSTEM
      /* TODO(mkm) cache /etc/hosts */
      FILE *fp;
      char line[1024];
      char *p;
      char alias[256];
      unsigned int a, b, c, d;
      int len = 0;
      
      if ((fp = fopen("/etc/hosts", "r")) == NULL) {
         return -1;
      }
      
      for (; fgets(line, sizeof(line), fp) != NULL;) {
         if (line[0] == '#') continue;
         
         if (sscanf(line, "%u.%u.%u.%u%n", &a, &b, &c, &d, &len) == 0) {
            /* TODO(mkm): handle ipv6 */
            continue;
         }
         for (p = line + len; sscanf(p, "%s%n", alias, &len) == 1; p += len) {
            if (strcmp(alias, name) == 0) {
               usa->sin.sin_addr.s_addr = htonl(a << 24 | b << 16 | c << 8 | d);
               fclose(fp);
               return 0;
            }
         }
      }
      
      fclose(fp);
#endif
      
      return -1;
   }
   
   static void mg_resolve_async_eh(struct mg_connection *nc, int ev, void *data) {
      time_t now = time(NULL);
      struct mg_resolve_async_request *req;
      struct mg_dns_message *msg;
      
      DBG(("ev=%d user_data=%p", ev, nc->user_data));
      
      req = (struct mg_resolve_async_request *) nc->user_data;
      
      if (req == NULL) {
         return;
      }
      
      switch (ev) {
         case MG_EV_CONNECT:
         case MG_EV_POLL:
            if (req->retries > req->max_retries) {
               req->err = MG_RESOLVE_EXCEEDED_RETRY_COUNT;
               nc->flags |= MG_F_CLOSE_IMMEDIATELY;
               break;
            }
            if (now - req->last_time >= req->timeout) {
               mg_send_dns_query(nc, req->name, req->query);
               req->last_time = now;
               req->retries++;
            }
            break;
         case MG_EV_RECV:
            msg = (struct mg_dns_message *) MG_MALLOC(sizeof(*msg));
            if (mg_parse_dns(nc->recv_mbuf.buf, *(int *) data, msg) == 0 &&
                msg->num_answers > 0) {
               req->callback(msg, req->data, MG_RESOLVE_OK);
               nc->user_data = NULL;
               MG_FREE(req);
            } else {
               req->err = MG_RESOLVE_NO_ANSWERS;
            }
            MG_FREE(msg);
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            break;
         case MG_EV_SEND:
            /*
             * If a send error occurs, prevent closing of the connection by the core.
             * We will retry after timeout.
             */
            nc->flags &= ~MG_F_CLOSE_IMMEDIATELY;
            mbuf_remove(&nc->send_mbuf, nc->send_mbuf.len);
            break;
         case MG_EV_TIMER:
            req->err = MG_RESOLVE_TIMEOUT;
            nc->flags |= MG_F_CLOSE_IMMEDIATELY;
            break;
         case MG_EV_CLOSE:
            /* If we got here with request still not done, fire an error callback. */
            if (req != NULL) {
               req->callback(NULL, req->data, req->err);
               nc->user_data = NULL;
               MG_FREE(req);
            }
            break;
      }
   }
   
   int mg_resolve_async(struct mg_mgr *mgr, const char *name, int query,
                        mg_resolve_callback_t cb, void *data) {
      struct mg_resolve_async_opts opts;
      memset(&opts, 0, sizeof(opts));
      return mg_resolve_async_opt(mgr, name, query, cb, data, opts);
   }
   
   int mg_resolve_async_opt(struct mg_mgr *mgr, const char *name, int query,
                            mg_resolve_callback_t cb, void *data,
                            struct mg_resolve_async_opts opts) {
      struct mg_resolve_async_request *req;
      struct mg_connection *dns_nc;
      const char *nameserver = opts.nameserver_url;
      
      DBG(("%s %d %p", name, query, opts.dns_conn));
      
      /* resolve with DNS */
      req = (struct mg_resolve_async_request *) MG_CALLOC(1, sizeof(*req));
      if (req == NULL) {
         return -1;
      }
      
      strncpy(req->name, name, sizeof(req->name));
      req->query = query;
      req->callback = cb;
      req->data = data;
      /* TODO(mkm): parse defaults out of resolve.conf */
      req->max_retries = opts.max_retries ? opts.max_retries : 2;
      req->timeout = opts.timeout ? opts.timeout : 5;
      
      /* Lazily initialize dns server */
      if (nameserver == NULL && mg_dns_server[0] == '\0' &&
          mg_get_ip_address_of_nameserver(mg_dns_server, sizeof(mg_dns_server)-10) ==
          -1) {
         strncpy(mg_dns_server, mg_default_dns_server, sizeof(mg_dns_server));
      }
      
      if (nameserver == NULL) {
         nameserver = mg_dns_server;
      }
      
      dns_nc = mg_connect(mgr, nameserver, mg_resolve_async_eh);
      if (dns_nc == NULL) {
         free(req);
         return -1;
      }
      dns_nc->user_data = req;
      if (opts.dns_conn != NULL) {
         *opts.dns_conn = dns_nc;
      }
      
      return 0;
   }
   
#endif /* MG_DISABLE_RESOLVE */
#ifdef MG_MODULE_LINES
#line 1 "./src/coap.c"
#endif
   /*
    * Copyright (c) 2015 Cesanta Software Limited
    * All rights reserved
    * This software is dual-licensed: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License version 2 as
    * published by the Free Software Foundation. For the terms of this
    * license, see <http://www.gnu.org/licenses/>.
    *
    * You are free to use this software under the terms of the GNU General
    * Public License, but WITHOUT ANY WARRANTY; without even the implied
    * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    * See the GNU General Public License for more details.
    *
    * Alternatively, you can license this software under a commercial
    * license, as set out in <https://www.cesanta.com/license>.
    */
   
   /* Amalgamated: #include "mongoose/src/internal.h" */
   /* Amalgamated: #include "mongoose/src/coap.h" */
   
#ifdef MG_ENABLE_COAP
   
   void mg_coap_free_options(struct mg_coap_message *cm) {
      while (cm->options != NULL) {
         struct mg_coap_option *next = cm->options->next;
         MG_FREE(cm->options);
         cm->options = next;
      }
   }
   
   struct mg_coap_option *mg_coap_add_option(struct mg_coap_message *cm,
                                             uint32_t number, char *value,
                                             size_t len) {
      struct mg_coap_option *new_option =
      (struct mg_coap_option *) MG_CALLOC(1, sizeof(*new_option));
      
      new_option->number = number;
      new_option->value.p = value;
      new_option->value.len = len;
      
      if (cm->options == NULL) {
         cm->options = cm->optiomg_tail = new_option;
      } else {
         /*
          * A very simple attention to help clients to compose options:
          * CoAP wants to see options ASC ordered.
          * Could be change by using sort in coap_compose
          */
         if (cm->optiomg_tail->number <= new_option->number) {
            /* if option is already ordered just add it */
            cm->optiomg_tail = cm->optiomg_tail->next = new_option;
         } else {
            /* looking for appropriate position */
            struct mg_coap_option *current_opt = cm->options;
            struct mg_coap_option *prev_opt = 0;
            
            while (current_opt != NULL) {
               if (current_opt->number > new_option->number) {
                  break;
               }
               prev_opt = current_opt;
               current_opt = current_opt->next;
            }
            
            if (prev_opt != NULL) {
               prev_opt->next = new_option;
               new_option->next = current_opt;
            } else {
               /* insert new_option to the beginning */
               new_option->next = cm->options;
               cm->options = new_option;
            }
         }
      }
      
      return new_option;
   }
   
   /*
    * Fills CoAP header in mg_coap_message.
    *
    * Helper function.
    */
   static char *coap_parse_header(char *ptr, struct mbuf *io,
                                  struct mg_coap_message *cm) {
      if (io->len < sizeof(uint32_t)) {
         cm->flags |= MG_COAP_NOT_ENOUGH_DATA;
         return NULL;
      }
      
      /*
       * Version (Ver):  2-bit unsigned integer.  Indicates the CoAP version
       * number.  Implementations of this specification MUST set this field
       * to 1 (01 binary).  Other values are reserved for future versions.
       * Messages with unknown version numbers MUST be silently ignored.
       */
      if (((uint8_t) *ptr >> 6) != 1) {
         cm->flags |= MG_COAP_IGNORE;
         return NULL;
      }
      
      /*
       * Type (T):  2-bit unsigned integer.  Indicates if this message is of
       * type Confirmable (0), Non-confirmable (1), Acknowledgement (2), or
       * Reset (3).
       */
      cm->msg_type = ((uint8_t) *ptr & 0x30) >> 4;
      cm->flags |= MG_COAP_MSG_TYPE_FIELD;
      
      /*
       * Token Length (TKL):  4-bit unsigned integer.  Indicates the length of
       * the variable-length Token field (0-8 bytes).  Lengths 9-15 are
       * reserved, MUST NOT be sent, and MUST be processed as a message
       * format error.
       */
      cm->token.len = *ptr & 0x0F;
      if (cm->token.len > 8) {
         cm->flags |= MG_COAP_FORMAT_ERROR;
         return NULL;
      }
      
      ptr++;
      
      /*
       * Code:  8-bit unsigned integer, split into a 3-bit class (most
       * significant bits) and a 5-bit detail (least significant bits)
       */
      cm->code_class = (uint8_t) *ptr >> 5;
      cm->code_detail = *ptr & 0x1F;
      cm->flags |= (MG_COAP_CODE_CLASS_FIELD | MG_COAP_CODE_DETAIL_FIELD);
      
      ptr++;
      
      /* Message ID:  16-bit unsigned integer in network byte order. */
      cm->msg_id = (uint8_t) *ptr << 8 | (uint8_t) * (ptr + 1);
      cm->flags |= MG_COAP_MSG_ID_FIELD;
      
      ptr += 2;
      
      return ptr;
   }
   
   /*
    * Fills token information in mg_coap_message.
    *
    * Helper function.
    */
   static char *coap_get_token(char *ptr, struct mbuf *io,
                               struct mg_coap_message *cm) {
      if (cm->token.len != 0) {
         if (ptr + cm->token.len > io->buf + io->len) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA;
            return NULL;
         } else {
            cm->token.p = ptr;
            ptr += cm->token.len;
            cm->flags |= MG_COAP_TOKEN_FIELD;
         }
      }
      
      return ptr;
   }
   
   /*
    * Returns Option Delta or Length.
    *
    * Helper function.
    */
   static int coap_get_ext_opt(char *ptr, struct mbuf *io, uint16_t *opt_info) {
      int ret = 0;
      
      if (*opt_info == 13) {
         /*
          * 13:  An 8-bit unsigned integer follows the initial byte and
          * indicates the Option Delta/Length minus 13.
          */
         if (ptr < io->buf + io->len) {
            *opt_info = (uint8_t) *ptr + 13;
            ret = sizeof(uint8_t);
         } else {
            ret = -1; /* LCOV_EXCL_LINE */
         }
      } else if (*opt_info == 14) {
         /*
          * 14:  A 16-bit unsigned integer in network byte order follows the
          * initial byte and indicates the Option Delta/Length minus 269.
          */
         if (ptr + sizeof(uint8_t) < io->buf + io->len) {
            *opt_info = ((uint8_t) *ptr << 8 | (uint8_t) * (ptr + 1)) + 269;
            ret = sizeof(uint16_t);
         } else {
            ret = -1; /* LCOV_EXCL_LINE */
         }
      }
      
      return ret;
   }
   
   /*
    * Fills options in mg_coap_message.
    *
    * Helper function.
    *
    * General options format:
    * +---------------+---------------+
    * | Option Delta  | Option Length |  1 byte
    * +---------------+---------------+
    * \    Option Delta (extended)    \  0-2 bytes
    * +-------------------------------+
    * / Option Length  (extended)     \  0-2 bytes
    * +-------------------------------+
    * \         Option Value          \  0 or more bytes
    * +-------------------------------+
    */
   static char *coap_get_options(char *ptr, struct mbuf *io,
                                 struct mg_coap_message *cm) {
      uint16_t prev_opt = 0;
      
      if (ptr == io->buf + io->len) {
         /* end of packet, ok */
         return NULL;
      }
      
      /* 0xFF is payload marker */
      while (ptr < io->buf + io->len && (uint8_t) *ptr != 0xFF) {
         uint16_t option_delta, option_lenght;
         int optinfo_len;
         
         /* Option Delta:  4-bit unsigned integer */
         option_delta = ((uint8_t) *ptr & 0xF0) >> 4;
         /* Option Length:  4-bit unsigned integer */
         option_lenght = *ptr & 0x0F;
         
         if (option_delta == 15 || option_lenght == 15) {
            /*
             * 15:  Reserved for future use.  If the field is set to this value,
             * it MUST be processed as a message format error
             */
            cm->flags |= MG_COAP_FORMAT_ERROR;
            break;
         }
         
         ptr++;
         
         /* check for extended option delta */
         optinfo_len = coap_get_ext_opt(ptr, io, &option_delta);
         if (optinfo_len == -1) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA; /* LCOV_EXCL_LINE */
            break;                                /* LCOV_EXCL_LINE */
         }
         
         ptr += optinfo_len;
         
         /* check or extended option lenght */
         optinfo_len = coap_get_ext_opt(ptr, io, &option_lenght);
         if (optinfo_len == -1) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA; /* LCOV_EXCL_LINE */
            break;                                /* LCOV_EXCL_LINE */
         }
         
         ptr += optinfo_len;
         
         /*
          * Instead of specifying the Option Number directly, the instances MUST
          * appear in order of their Option Numbers and a delta encoding is used
          * between them.
          */
         option_delta += prev_opt;
         
         mg_coap_add_option(cm, option_delta, ptr, option_lenght);
         
         prev_opt = option_delta;
         
         if (ptr + option_lenght > io->buf + io->len) {
            cm->flags |= MG_COAP_NOT_ENOUGH_DATA; /* LCOV_EXCL_LINE */
            break;                                /* LCOV_EXCL_LINE */
         }
         
         ptr += option_lenght;
      }
      
      if ((cm->flags & MG_COAP_ERROR) != 0) {
         mg_coap_free_options(cm);
         return NULL;
      }
      
      cm->flags |= MG_COAP_OPTIOMG_FIELD;
      
      if (ptr == io->buf + io->len) {
         /* end of packet, ok */
         return NULL;
      }
      
      ptr++;
      
      return ptr;
   }
   
   uint32_t mg_coap_parse(struct mbuf *io, struct mg_coap_message *cm) {
      char *ptr;
      
      memset(cm, 0, sizeof(*cm));
      
      if ((ptr = coap_parse_header(io->buf, io, cm)) == NULL) {
         return cm->flags;
      }
      
      if ((ptr = coap_get_token(ptr, io, cm)) == NULL) {
         return cm->flags;
      }
      
      if ((ptr = coap_get_options(ptr, io, cm)) == NULL) {
         return cm->flags;
      }
      
      /* the rest is payload */
      cm->payload.len = io->len - (ptr - io->buf);
      if (cm->payload.len != 0) {
         cm->payload.p = ptr;
         cm->flags |= MG_COAP_PAYLOAD_FIELD;
      }
      
      return cm->flags;
   }
   
   /*
    * Calculates extended size of given Opt Number/Length in coap message.
    *
    * Helper function.
    */
   static size_t coap_get_ext_opt_size(uint32_t value) {
      int ret = 0;
      
      if (value >= 13 && value <= 0xFF + 13) {
         ret = sizeof(uint8_t);
      } else if (value > 0xFF + 13 && value <= 0xFFFF + 269) {
         ret = sizeof(uint16_t);
      }
      
      return ret;
   }
   
   /*
    * Splits given Opt Number/Length into base and ext values.
    *
    * Helper function.
    */
   static int coap_split_opt(uint32_t value, uint8_t *base, uint16_t *ext) {
      int ret = 0;
      
      if (value < 13) {
         *base = value;
      } else if (value >= 13 && value <= 0xFF + 13) {
         *base = 13;
         *ext = value - 13;
         ret = sizeof(uint8_t);
      } else if (value > 0xFF + 13 && value <= 0xFFFF + 269) {
         *base = 14;
         *ext = value - 269;
         ret = sizeof(uint16_t);
      }
      
      return ret;
   }
   
   /*
    * Puts uint16_t (in network order) into given char stream.
    *
    * Helper function.
    */
   static char *coap_add_uint16(char *ptr, uint16_t val) {
      *ptr = val >> 8;
      ptr++;
      *ptr = val & 0x00FF;
      ptr++;
      return ptr;
   }
   
   /*
    * Puts extended value of Opt Number/Length into given char stream.
    *
    * Helper function.
    */
   static char *coap_add_opt_info(char *ptr, uint16_t val, size_t len) {
      if (len == sizeof(uint8_t)) {
         *ptr = val;
         ptr++;
      } else if (len == sizeof(uint16_t)) {
         ptr = coap_add_uint16(ptr, val);
      }
      
      return ptr;
   }
   
   /*
    * Verifies given mg_coap_message and calculates message size for it.
    *
    * Helper function.
    */
   static uint32_t coap_calculate_packet_size(struct mg_coap_message *cm,
                                              size_t *len) {
      struct mg_coap_option *opt;
      uint32_t prev_opt_number;
      
      *len = 4; /* header */
      if (cm->msg_type > MG_COAP_MSG_MAX) {
         return MG_COAP_ERROR | MG_COAP_MSG_TYPE_FIELD;
      }
      if (cm->token.len > 8) {
         return MG_COAP_ERROR | MG_COAP_TOKEN_FIELD;
      }
      if (cm->code_class > 7) {
         return MG_COAP_ERROR | MG_COAP_CODE_CLASS_FIELD;
      }
      if (cm->code_detail > 31) {
         return MG_COAP_ERROR | MG_COAP_CODE_DETAIL_FIELD;
      }
      
      *len += cm->token.len;
      if (cm->payload.len != 0) {
         *len += cm->payload.len + 1; /* ... + 1; add payload marker */
      }
      
      opt = cm->options;
      prev_opt_number = 0;
      while (opt != NULL) {
         *len += 1; /* basic delta/length */
         *len += coap_get_ext_opt_size(opt->number);
         *len += coap_get_ext_opt_size((uint32_t) opt->value.len);
         /*
          * Current implementation performs check if
          * option_number > previous option_number and produces an error
          * TODO(alashkin): write design doc with limitations
          * May be resorting is more suitable solution.
          */
         if ((opt->next != NULL && opt->number > opt->next->number) ||
             opt->value.len > 0xFFFF + 269 ||
             opt->number - prev_opt_number > 0xFFFF + 269) {
            return MG_COAP_ERROR | MG_COAP_OPTIOMG_FIELD;
         }
         *len += opt->value.len;
         opt = opt->next;
      }
      
      return 0;
   }
   
   uint32_t mg_coap_compose(struct mg_coap_message *cm, struct mbuf *io) {
      struct mg_coap_option *opt;
      uint32_t res, prev_opt_number;
      size_t prev_io_len, packet_size;
      char *ptr;
      
      res = coap_calculate_packet_size(cm, &packet_size);
      if (res != 0) {
         return res;
      }
      
      /* saving previous lenght to handle non-empty mbuf */
      prev_io_len = io->len;
      mbuf_append(io, NULL, packet_size);
      ptr = io->buf + prev_io_len;
      
      /*
       * since cm is verified, it is possible to use bits shift operator
       * without additional zeroing of unused bits
       */
      
      /* ver: 2 bits, msg_type: 2 bits, toklen: 4 bits */
      *ptr = (1 << 6) | (cm->msg_type << 4) | (cm->token.len);
      ptr++;
      
      /* code class: 3 bits, code detail: 5 bits */
      *ptr = (cm->code_class << 5) | (cm->code_detail);
      ptr++;
      
      ptr = coap_add_uint16(ptr, cm->msg_id);
      
      if (cm->token.len != 0) {
         memcpy(ptr, cm->token.p, cm->token.len);
         ptr += cm->token.len;
      }
      
      opt = cm->options;
      prev_opt_number = 0;
      while (opt != NULL) {
         uint8_t delta_base = 0, length_base = 0;
         uint16_t delta_ext, length_ext;
         
         size_t opt_delta_len =
         coap_split_opt(opt->number - prev_opt_number, &delta_base, &delta_ext);
         size_t opt_lenght_len =
         coap_split_opt((uint32_t) opt->value.len, &length_base, &length_ext);
         
         *ptr = (delta_base << 4) | length_base;
         ptr++;
         
         ptr = coap_add_opt_info(ptr, delta_ext, opt_delta_len);
         ptr = coap_add_opt_info(ptr, length_ext, opt_lenght_len);
         
         if (opt->value.len != 0) {
            memcpy(ptr, opt->value.p, opt->value.len);
            ptr += opt->value.len;
         }
         
         prev_opt_number = opt->number;
         opt = opt->next;
      }
      
      if (cm->payload.len != 0) {
         *ptr = -1;
         ptr++;
         memcpy(ptr, cm->payload.p, cm->payload.len);
      }
      
      return 0;
   }
   
   uint32_t mg_coap_send_message(struct mg_connection *nc,
                                 struct mg_coap_message *cm) {
      struct mbuf packet_out;
      uint32_t compose_res;
      
      mbuf_init(&packet_out, 0);
      compose_res = mg_coap_compose(cm, &packet_out);
      if (compose_res != 0) {
         return compose_res; /* LCOV_EXCL_LINE */
      }
      
      mg_send(nc, packet_out.buf, (int) packet_out.len);
      mbuf_free(&packet_out);
      
      return 0;
   }
   
   uint32_t mg_coap_send_ack(struct mg_connection *nc, uint16_t msg_id) {
      struct mg_coap_message cm;
      memset(&cm, 0, sizeof(cm));
      cm.msg_type = MG_COAP_MSG_ACK;
      cm.msg_id = msg_id;
      
      return mg_coap_send_message(nc, &cm);
   }
   
   static void coap_handler(struct mg_connection *nc, int ev, void *ev_data) {
      struct mbuf *io = &nc->recv_mbuf;
      struct mg_coap_message cm;
      uint32_t parse_res;
      
      memset(&cm, 0, sizeof(cm));
      
      nc->handler(nc, ev, ev_data);
      
      switch (ev) {
         case MG_EV_RECV:
            parse_res = mg_coap_parse(io, &cm);
            if ((parse_res & MG_COAP_IGNORE) == 0) {
               if ((cm.flags & MG_COAP_NOT_ENOUGH_DATA) != 0) {
                  /*
                   * Since we support UDP only
                   * MG_COAP_NOT_ENOUGH_DATA == MG_COAP_FORMAT_ERROR
                   */
                  cm.flags |= MG_COAP_FORMAT_ERROR; /* LCOV_EXCL_LINE */
               }                                   /* LCOV_EXCL_LINE */
               nc->handler(nc, MG_COAP_EVENT_BASE + cm.msg_type, &cm);
            }
            
            mg_coap_free_options(&cm);
            mbuf_remove(io, io->len);
            break;
      }
   }
   /*
    * Attach built-in CoAP event handler to the given connection.
    *
    * The user-defined event handler will receive following extra events:
    *
    * - MG_EV_COAP_CON
    * - MG_EV_COAP_NOC
    * - MG_EV_COAP_ACK
    * - MG_EV_COAP_RST
    */
   int mg_set_protocol_coap(struct mg_connection *nc) {
      /* supports UDP only */
      if ((nc->flags & MG_F_UDP) == 0) {
         return -1;
      }
      
      nc->proto_handler = coap_handler;
      
      return 0;
   }
   
#endif /* MG_DISABLE_COAP */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/platforms/cc3200/cc3200_libc.c"
#endif
   /*
    * Copyright (c) 2014-2016 Cesanta Software Limited
    * All rights reserved
    */
   
#if CS_PLATFORM == CS_P_CC3200
   
#include <stdio.h>
#include <string.h>
   
#ifndef __TI_COMPILER_VERSION__
#include <reent.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#endif
   
#include <inc/hw_types.h>
#include <inc/hw_memmap.h>
#include <driverlib/prcm.h>
#include <driverlib/rom.h>
#include <driverlib/rom_map.h>
#include <driverlib/uart.h>
#include <driverlib/utils.h>
   
#define CONSOLE_UART UARTA0_BASE
   
#ifdef __TI_COMPILER_VERSION__
   int asprintf(char **strp, const char *fmt, ...) {
      va_list ap;
      int len;
      
      *strp = malloc(BUFSIZ);
      if (*strp == NULL) return -1;
      
      va_start(ap, fmt);
      len = vsnprintf(*strp, BUFSIZ, fmt, ap);
      va_end(ap);
      
      if (len > 0) {
         *strp = realloc(*strp, len);
         if (*strp == NULL) return -1;
      }
      
      if (len >= BUFSIZ) {
         va_start(ap, fmt);
         len = vsnprintf(*strp, len, fmt, ap);
         va_end(ap);
      }
      
      return len;
   }
#endif /* __TI_COMPILER_VERSION__ */
   
#ifndef __TI_COMPILER_VERSION__
   int _gettimeofday_r(struct _reent *r, struct timeval *tp, void *tzp) {
#else
      int gettimeofday(struct timeval *tp, void *tzp) {
#endif
         unsigned long long r1 = 0, r2;
         /* Achieve two consecutive reads of the same value. */
         do {
            r2 = r1;
            r1 = PRCMSlowClkCtrFastGet();
         } while (r1 != r2);
         /* This is a 32768 Hz counter. */
         tp->tv_sec = (r1 >> 15);
         /* 1/32768-th of a second is 30.517578125 microseconds, approx. 31,
          * but we round down so it doesn't overflow at 32767 */
         tp->tv_usec = (r1 & 0x7FFF) * 30;
         return 0;
      }
      
      long int random(void) {
         return 42; /* FIXME */
      }
      
      void fprint_str(FILE *fp, const char *str) {
         while (*str != '\0') {
            if (*str == '\n') MAP_UARTCharPut(CONSOLE_UART, '\r');
            MAP_UARTCharPut(CONSOLE_UART, *str++);
         }
      }
      
      void _exit(int status) {
         fprint_str(stderr, "_exit\n");
         /* cause an unaligned access exception, that will drop you into gdb */
         *(int *) 1 = status;
         while (1)
            ; /* avoid gcc warning because stdlib abort() has noreturn attribute */
      }
      
      void _not_implemented(const char *what) {
         fprint_str(stderr, what);
         fprint_str(stderr, " is not implemented\n");
         _exit(42);
      }
      
      int _kill(int pid, int sig) {
         (void) pid;
         (void) sig;
         _not_implemented("_kill");
         return -1;
      }
      
      int _getpid() {
         fprint_str(stderr, "_getpid is not implemented\n");
         return 42;
      }
      
      int _isatty(int fd) {
         /* 0, 1 and 2 are TTYs. */
         return fd < 2;
      }
      
#endif /* CS_PLATFORM == CS_P_CC3200 */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/platforms/msp432/msp432_libc.c"
#endif
      /*
       * Copyright (c) 2014-2016 Cesanta Software Limited
       * All rights reserved
       */
      
#if CS_PLATFORM == CS_P_MSP432
      
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Clock.h>
      
      int gettimeofday(struct timeval *tp, void *tzp) {
         uint32_t ticks = Clock_getTicks();
         tp->tv_sec = ticks / 1000;
         tp->tv_usec = (ticks % 1000) * 1000;
         return 0;
      }
      
      long int random(void) {
         return 42; /* FIXME */
      }
      
#endif /* CS_PLATFORM == CS_P_MSP432 */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/platforms/simplelink/sl_fs_slfs.h"
#endif
      /*
       * Copyright (c) 2014-2016 Cesanta Software Limited
       * All rights reserved
       */
      
#ifndef CS_COMMON_PLATFORMS_SIMPLELINK_SL_FS_SLFS_H_
#define CS_COMMON_PLATFORMS_SIMPLELINK_SL_FS_SLFS_H_
      
#if defined(MG_FS_SLFS)
      
#include <stdio.h>
#ifndef __TI_COMPILER_VERSION__
#include <unistd.h>
#include <sys/stat.h>
#endif
      
#define MAX_OPEN_SLFS_FILES 8
      
      /* Indirect libc interface - same functions, different names. */
      int fs_slfs_open(const char *pathname, int flags, mode_t mode);
      int fs_slfs_close(int fd);
      ssize_t fs_slfs_read(int fd, void *buf, size_t count);
      ssize_t fs_slfs_write(int fd, const void *buf, size_t count);
      int fs_slfs_stat(const char *pathname, struct stat *s);
      int fs_slfs_fstat(int fd, struct stat *s);
      off_t fs_slfs_lseek(int fd, off_t offset, int whence);
      int fs_slfs_unlink(const char *filename);
      int fs_slfs_rename(const char *from, const char *to);
      
      void fs_slfs_set_new_file_size(const char *name, size_t size);
      
#endif /* defined(MG_FS_SLFS) */
      
#endif /* CS_COMMON_PLATFORMS_SIMPLELINK_SL_FS_SLFS_H_ */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/platforms/simplelink/sl_fs_slfs.c"
#endif
      /*
       * Copyright (c) 2014-2016 Cesanta Software Limited
       * All rights reserved
       */
      
      /* Standard libc interface to TI SimpleLink FS. */
      
#if defined(MG_FS_SLFS) || defined(CC3200_FS_SLFS)
      
      /* Amalgamated: #include "common/platforms/simplelink/sl_fs_slfs.h" */
      
#include <errno.h>
      
#if CS_PLATFORM == CS_P_CC3200
#include <inc/hw_types.h>
#endif
#include <simplelink/include/simplelink.h>
#include <simplelink/include/fs.h>
      
      /* Amalgamated: #include "common/cs_dbg.h" */
      
      extern int set_errno(int e); /* From sl_fs.c */
      
      /*
       * With SLFS, you have to pre-declare max file size. Yes. Really.
       * 64K should be enough for everyone. Right?
       */
#ifndef FS_SLFS_MAX_FILE_SIZE
#define FS_SLFS_MAX_FILE_SIZE (64 * 1024)
#endif
      
      struct sl_file_size_hint {
         char *name;
         size_t size;
      };
      
      struct sl_fd_info {
         _i32 fh;
         _off_t pos;
         size_t size;
      };
      
      static struct sl_fd_info s_sl_fds[MAX_OPEN_SLFS_FILES];
      static struct sl_file_size_hint s_sl_file_size_hints[MAX_OPEN_SLFS_FILES];
      
      static int sl_fs_to_errno(_i32 r) {
         DBG(("SL error: %d", (int) r));
         switch (r) {
            case SL_FS_OK:
               return 0;
            case SL_FS_FILE_NAME_EXIST:
               return EEXIST;
            case SL_FS_WRONG_FILE_NAME:
               return EINVAL;
            case SL_FS_ERR_NO_AVAILABLE_NV_INDEX:
            case SL_FS_ERR_NO_AVAILABLE_BLOCKS:
               return ENOSPC;
            case SL_FS_ERR_FAILED_TO_ALLOCATE_MEM:
               return ENOMEM;
            case SL_FS_ERR_FILE_NOT_EXISTS:
               return ENOENT;
            case SL_FS_ERR_NOT_SUPPORTED:
               return ENOTSUP;
         }
         return ENXIO;
      }
      
      int fs_slfs_open(const char *pathname, int flags, mode_t mode) {
         int fd;
         for (fd = 0; fd < MAX_OPEN_SLFS_FILES; fd++) {
            if (s_sl_fds[fd].fh <= 0) break;
         }
         if (fd >= MAX_OPEN_SLFS_FILES) return set_errno(ENOMEM);
         struct sl_fd_info *fi = &s_sl_fds[fd];
         
         _u32 am = 0;
         fi->size = (size_t) -1;
         if (pathname[0] == '/') pathname++;
         int rw = (flags & 3);
         if (rw == O_RDONLY) {
            SlFsFileInfo_t sl_fi;
            _i32 r = sl_FsGetInfo((const _u8 *) pathname, 0, &sl_fi);
            if (r == SL_FS_OK) {
               fi->size = sl_fi.FileLen;
            }
            am = FS_MODE_OPEN_READ;
         } else {
            if (!(flags & O_TRUNC) || (flags & O_APPEND)) {
               // FailFS files cannot be opened for append and will be truncated
               // when opened for write.
               return set_errno(ENOTSUP);
            }
            if (flags & O_CREAT) {
               size_t i, size = FS_SLFS_MAX_FILE_SIZE;
               for (i = 0; i < MAX_OPEN_SLFS_FILES; i++) {
                  if (s_sl_file_size_hints[i].name != NULL &&
                      strcmp(s_sl_file_size_hints[i].name, pathname) == 0) {
                     size = s_sl_file_size_hints[i].size;
                     free(s_sl_file_size_hints[i].name);
                     s_sl_file_size_hints[i].name = NULL;
                     break;
                  }
               }
               DBG(("creating %s with max size %d", pathname, (int) size));
               am = FS_MODE_OPEN_CREATE(size, 0);
            } else {
               am = FS_MODE_OPEN_WRITE;
            }
         }
         _i32 r = sl_FsOpen((_u8 *) pathname, am, NULL, &fi->fh);
         DBG(("sl_FsOpen(%s, 0x%x) = %d, %d", pathname, (int) am, (int) r,
              (int) fi->fh));
         if (r == SL_FS_OK) {
            fi->pos = 0;
            r = fd;
         } else {
            fi->fh = -1;
            r = set_errno(sl_fs_to_errno(r));
         }
         return r;
      }
      
      int fs_slfs_close(int fd) {
         struct sl_fd_info *fi = &s_sl_fds[fd];
         if (fi->fh <= 0) return set_errno(EBADF);
         _i32 r = sl_FsClose(fi->fh, NULL, NULL, 0);
         DBG(("sl_FsClose(%d) = %d", (int) fi->fh, (int) r));
         s_sl_fds[fd].fh = -1;
         return set_errno(sl_fs_to_errno(r));
      }
      
      ssize_t fs_slfs_read(int fd, void *buf, size_t count) {
         struct sl_fd_info *fi = &s_sl_fds[fd];
         if (fi->fh <= 0) return set_errno(EBADF);
         /* Simulate EOF. sl_FsRead @ file_size return SL_FS_ERR_OFFSET_OUT_OF_RANGE.
          */
         if (fi->pos == fi->size) return 0;
         _i32 r = sl_FsRead(fi->fh, fi->pos, buf, count);
         DBG(("sl_FsRead(%d, %d, %d) = %d", (int) fi->fh, (int) fi->pos, (int) count,
              (int) r));
         if (r >= 0) {
            fi->pos += r;
            return r;
         }
         return set_errno(sl_fs_to_errno(r));
      }
      
      ssize_t fs_slfs_write(int fd, const void *buf, size_t count) {
         struct sl_fd_info *fi = &s_sl_fds[fd];
         if (fi->fh <= 0) return set_errno(EBADF);
         _i32 r = sl_FsWrite(fi->fh, fi->pos, (_u8 *) buf, count);
         DBG(("sl_FsWrite(%d, %d, %d) = %d", (int) fi->fh, (int) fi->pos, (int) count,
              (int) r));
         if (r >= 0) {
            fi->pos += r;
            return r;
         }
         return set_errno(sl_fs_to_errno(r));
      }
      
      int fs_slfs_stat(const char *pathname, struct stat *s) {
         SlFsFileInfo_t sl_fi;
         _i32 r = sl_FsGetInfo((const _u8 *) pathname, 0, &sl_fi);
         if (r == SL_FS_OK) {
            s->st_mode = S_IFREG | 0666;
            s->st_nlink = 1;
            s->st_size = sl_fi.FileLen;
            return 0;
         }
         return set_errno(sl_fs_to_errno(r));
      }
      
      int fs_slfs_fstat(int fd, struct stat *s) {
         struct sl_fd_info *fi = &s_sl_fds[fd];
         if (fi->fh <= 0) return set_errno(EBADF);
         s->st_mode = 0666;
         s->st_mode = S_IFREG | 0666;
         s->st_nlink = 1;
         s->st_size = fi->size;
         return 0;
      }
      
      off_t fs_slfs_lseek(int fd, off_t offset, int whence) {
         if (s_sl_fds[fd].fh <= 0) return set_errno(EBADF);
         switch (whence) {
            case SEEK_SET:
               s_sl_fds[fd].pos = offset;
               break;
            case SEEK_CUR:
               s_sl_fds[fd].pos += offset;
               break;
            case SEEK_END:
               return set_errno(ENOTSUP);
         }
         return 0;
      }
      
      int fs_slfs_unlink(const char *filename) {
         return set_errno(sl_fs_to_errno(sl_FsDel((const _u8 *) filename, 0)));
      }
      
      int fs_slfs_rename(const char *from, const char *to) {
         return set_errno(ENOTSUP);
      }
      
      void fs_slfs_set_new_file_size(const char *name, size_t size) {
         int i;
         for (i = 0; i < MAX_OPEN_SLFS_FILES; i++) {
            if (s_sl_file_size_hints[i].name == NULL) {
               DBG(("File size hint: %s %d", name, (int) size));
               s_sl_file_size_hints[i].name = strdup(name);
               s_sl_file_size_hints[i].size = size;
               break;
            }
         }
      }
      
#endif /* defined(MG_FS_SLFS) || defined(CC3200_FS_SLFS) */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/platforms/simplelink/sl_fs.c"
#endif
      /*
       * Copyright (c) 2014-2016 Cesanta Software Limited
       * All rights reserved
       */
      
#if defined(MG_SOCKET_SIMPLELINK) && \
(defined(MG_FS_SLFS) || defined(MG_FS_SPIFFS))
      
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef __TI_COMPILER_VERSION__
#include <file.h>
#endif
      
#if CS_PLATFORM == CS_P_CC3200
#include <inc/hw_types.h>
#include <inc/hw_memmap.h>
#include <driverlib/rom.h>
#include <driverlib/rom_map.h>
#include <driverlib/uart.h>
#endif
      
      /* Amalgamated: #include "common/cs_dbg.h" */
      /* Amalgamated: #include "common/platform.h" */
      
#ifdef CC3200_FS_SPIFFS
      /* Amalgamated: #include "cc3200_fs_spiffs.h" */
#endif
      
#ifdef MG_FS_SLFS
      /* Amalgamated: #include "sl_fs_slfs.h" */
#endif
      
#define NUM_SYS_FDS 3
#define SPIFFS_FD_BASE 10
#define SLFS_FD_BASE 100
      
#define CONSOLE_UART UARTA0_BASE
      
      int set_errno(int e) {
         errno = e;
         return -e;
      }
      
      static int is_sl_fname(const char *fname) {
         return strncmp(fname, "SL:", 3) == 0;
      }
      
      static const char *sl_fname(const char *fname) {
         return fname + 3;
      }
      
      static const char *drop_dir(const char *fname) {
         if (*fname == '.') fname++;
         if (*fname == '/') fname++;
         return fname;
      }
      
      enum fd_type {
         FD_INVALID,
         FD_SYS,
#ifdef CC3200_FS_SPIFFS
         FD_SPIFFS,
#endif
#ifdef MG_FS_SLFS
         FD_SLFS
#endif
      };
      static int fd_type(int fd) {
         if (fd >= 0 && fd < NUM_SYS_FDS) return FD_SYS;
#ifdef CC3200_FS_SPIFFS
         if (fd >= SPIFFS_FD_BASE && fd < SPIFFS_FD_BASE + MAX_OPEN_SPIFFS_FILES) {
            return FD_SPIFFS;
         }
#endif
#ifdef MG_FS_SLFS
         if (fd >= SLFS_FD_BASE && fd < SLFS_FD_BASE + MAX_OPEN_SLFS_FILES) {
            return FD_SLFS;
         }
#endif
         return FD_INVALID;
      }
      
      int _open(const char *pathname, int flags, mode_t mode) {
         int fd = -1;
         pathname = drop_dir(pathname);
         if (is_sl_fname(pathname)) {
#ifdef MG_FS_SLFS
            fd = fs_slfs_open(sl_fname(pathname), flags, mode);
            if (fd >= 0) fd += SLFS_FD_BASE;
#endif
         } else {
#ifdef CC3200_FS_SPIFFS
            fd = fs_spiffs_open(pathname, flags, mode);
            if (fd >= 0) fd += SPIFFS_FD_BASE;
#endif
         }
         DBG(("open(%s, 0x%x) = %d", pathname, flags, fd));
         return fd;
      }
      
      int _stat(const char *pathname, struct stat *st) {
         int res = -1;
         const char *fname = pathname;
         int is_sl = is_sl_fname(pathname);
         if (is_sl) fname = sl_fname(pathname);
         fname = drop_dir(fname);
         memset(st, 0, sizeof(*st));
         /* Simulate statting the root directory. */
         if (strcmp(fname, "") == 0) {
            st->st_ino = 0;
            st->st_mode = S_IFDIR | 0777;
            st->st_nlink = 1;
            st->st_size = 0;
            return 0;
         }
         if (is_sl) {
#ifdef MG_FS_SLFS
            res = fs_slfs_stat(fname, st);
#endif
         } else {
#ifdef CC3200_FS_SPIFFS
            res = fs_spiffs_stat(fname, st);
#endif
         }
         DBG(("stat(%s) = %d; fname = %s", pathname, res, fname));
         return res;
      }
      
      int _close(int fd) {
         int r = -1;
         switch (fd_type(fd)) {
            case FD_INVALID:
               r = set_errno(EBADF);
               break;
            case FD_SYS:
               r = set_errno(EACCES);
               break;
#ifdef CC3200_FS_SPIFFS
            case FD_SPIFFS:
               r = fs_spiffs_close(fd - SPIFFS_FD_BASE);
               break;
#endif
#ifdef MG_FS_SLFS
            case FD_SLFS:
               r = fs_slfs_close(fd - SLFS_FD_BASE);
               break;
#endif
         }
         DBG(("close(%d) = %d", fd, r));
         return r;
      }
      
      off_t _lseek(int fd, off_t offset, int whence) {
         int r = -1;
         switch (fd_type(fd)) {
            case FD_INVALID:
               r = set_errno(EBADF);
               break;
            case FD_SYS:
               r = set_errno(ESPIPE);
               break;
#ifdef CC3200_FS_SPIFFS
            case FD_SPIFFS:
               r = fs_spiffs_lseek(fd - SPIFFS_FD_BASE, offset, whence);
               break;
#endif
#ifdef MG_FS_SLFS
            case FD_SLFS:
               r = fs_slfs_lseek(fd - SLFS_FD_BASE, offset, whence);
               break;
#endif
         }
         DBG(("lseek(%d, %d, %d) = %d", fd, (int) offset, whence, r));
         return r;
      }
      
      int _fstat(int fd, struct stat *s) {
         int r = -1;
         memset(s, 0, sizeof(*s));
         switch (fd_type(fd)) {
            case FD_INVALID:
               r = set_errno(EBADF);
               break;
            case FD_SYS: {
               /* Create barely passable stats for STD{IN,OUT,ERR}. */
               memset(s, 0, sizeof(*s));
               s->st_ino = fd;
               s->st_mode = S_IFCHR | 0666;
               r = 0;
               break;
            }
#ifdef CC3200_FS_SPIFFS
            case FD_SPIFFS:
               r = fs_spiffs_fstat(fd - SPIFFS_FD_BASE, s);
               break;
#endif
#ifdef MG_FS_SLFS
            case FD_SLFS:
               r = fs_slfs_fstat(fd - SLFS_FD_BASE, s);
               break;
#endif
         }
         DBG(("fstat(%d) = %d", fd, r));
         return r;
      }
      
      ssize_t _read(int fd, void *buf, size_t count) {
         int r = -1;
         switch (fd_type(fd)) {
            case FD_INVALID:
               r = set_errno(EBADF);
               break;
            case FD_SYS: {
               if (fd != 0) {
                  r = set_errno(EACCES);
                  break;
               }
               /* Should we allow reading from stdin = uart? */
               r = set_errno(ENOTSUP);
               break;
            }
#ifdef CC3200_FS_SPIFFS
            case FD_SPIFFS:
               r = fs_spiffs_read(fd - SPIFFS_FD_BASE, buf, count);
               break;
#endif
#ifdef MG_FS_SLFS
            case FD_SLFS:
               r = fs_slfs_read(fd - SLFS_FD_BASE, buf, count);
               break;
#endif
         }
         DBG(("read(%d, %u) = %d", fd, count, r));
         return r;
      }
      
      ssize_t _write(int fd, const void *buf, size_t count) {
         int r = -1;
         size_t i = 0;
         switch (fd_type(fd)) {
            case FD_INVALID:
               r = set_errno(EBADF);
               break;
            case FD_SYS: {
               if (fd == 0) {
                  r = set_errno(EACCES);
                  break;
               }
#if CS_PLATFORM == CS_P_CC3200
               for (i = 0; i < count; i++) {
                  const char c = ((const char *) buf)[i];
                  if (c == '\n') MAP_UARTCharPut(CONSOLE_UART, '\r');
                  MAP_UARTCharPut(CONSOLE_UART, c);
               }
#else
               (void) i;
#endif
               r = count;
               break;
            }
#ifdef CC3200_FS_SPIFFS
            case FD_SPIFFS:
               r = fs_spiffs_write(fd - SPIFFS_FD_BASE, buf, count);
               break;
#endif
#ifdef MG_FS_SLFS
            case FD_SLFS:
               r = fs_slfs_write(fd - SLFS_FD_BASE, buf, count);
               break;
#endif
         }
         return r;
      }
      
      int _rename(const char *from, const char *to) {
         int r = -1;
         from = drop_dir(from);
         to = drop_dir(to);
         if (is_sl_fname(from) || is_sl_fname(to)) {
#ifdef MG_FS_SLFS
            r = fs_slfs_rename(sl_fname(from), sl_fname(to));
#endif
         } else {
#ifdef CC3200_FS_SPIFFS
            r = fs_spiffs_rename(from, to);
#endif
         }
         DBG(("rename(%s, %s) = %d", from, to, r));
         return r;
      }
      
      int _link(const char *from, const char *to) {
         DBG(("link(%s, %s)", from, to));
         return set_errno(ENOTSUP);
      }
      
      int _unlink(const char *filename) {
         int r = -1;
         filename = drop_dir(filename);
         if (is_sl_fname(filename)) {
#ifdef MG_FS_SLFS
            r = fs_slfs_unlink(sl_fname(filename));
#endif
         } else {
#ifdef CC3200_FS_SPIFFS
            r = fs_spiffs_unlink(filename);
#endif
         }
         DBG(("unlink(%s) = %d", filename, r));
         return r;
      }
      
#ifdef CC3200_FS_SPIFFS /* FailFS does not support listing files. */
      DIR *opendir(const char *dir_name) {
         DIR *r = NULL;
         if (is_sl_fname(dir_name)) {
            r = NULL;
            set_errno(ENOTSUP);
         } else {
            r = fs_spiffs_opendir(dir_name);
         }
         DBG(("opendir(%s) = %p", dir_name, r));
         return r;
      }
      
      struct dirent *readdir(DIR *dir) {
         struct dirent *res = fs_spiffs_readdir(dir);
         DBG(("readdir(%p) = %p", dir, res));
         return res;
      }
      
      int closedir(DIR *dir) {
         int res = fs_spiffs_closedir(dir);
         DBG(("closedir(%p) = %d", dir, res));
         return res;
      }
      
      int rmdir(const char *path) {
         return fs_spiffs_rmdir(path);
      }
      
      int mkdir(const char *path, mode_t mode) {
         (void) path;
         (void) mode;
         /* for spiffs supports only root dir, which comes from mongoose as '.' */
         return (strlen(path) == 1 && *path == '.') ? 0 : ENOTDIR;
      }
#endif
      
      int sl_fs_init() {
         int ret = 1;
#ifdef __TI_COMPILER_VERSION__
#ifdef MG_FS_SLFS
#pragma diag_push
#pragma diag_suppress 169 /* Nothing we can do about the prototype mismatch. */
         ret = (add_device("SL", _MSA, fs_slfs_open, fs_slfs_close, fs_slfs_read,
                           fs_slfs_write, fs_slfs_lseek, fs_slfs_unlink,
                           fs_slfs_rename) == 0);
#pragma diag_pop
#endif
#endif
         return ret;
      }
      
#endif /* defined(MG_SOCKET_SIMPLELINK) && (defined(MG_FS_SLFS) || \
defined(MG_FS_SPIFFS)) */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/platforms/simplelink/sl_socket.c"
#endif
      /*
       * Copyright (c) 2014-2016 Cesanta Software Limited
       * All rights reserved
       */
      
#ifdef MG_SOCKET_SIMPLELINK
      
#include <errno.h>
#include <stdio.h>
      
      /* Amalgamated: #include "common/platform.h" */
      
#include <simplelink/include/netapp.h>
      
      const char *inet_ntop(int af, const void *src, char *dst, socklen_t size) {
         int res;
         struct in_addr *in = (struct in_addr *) src;
         if (af != AF_INET) {
            errno = EAFNOSUPPORT;
            return NULL;
         }
         res = snprintf(dst, size, "%lu.%lu.%lu.%lu", SL_IPV4_BYTE(in->s_addr, 0),
                        SL_IPV4_BYTE(in->s_addr, 1), SL_IPV4_BYTE(in->s_addr, 2),
                        SL_IPV4_BYTE(in->s_addr, 3));
         return res > 0 ? dst : NULL;
      }
      
      char *inet_ntoa(struct in_addr n) {
         static char a[16];
         return (char *) inet_ntop(AF_INET, &n, a, sizeof(n));
      }
      
      int inet_pton(int af, const char *src, void *dst) {
         uint32_t a0, a1, a2, a3;
         uint8_t *db = (uint8_t *) dst;
         if (af != AF_INET) {
            errno = EAFNOSUPPORT;
            return 0;
         }
         if (sscanf(src, "%lu.%lu.%lu.%lu", &a0, &a1, &a2, &a3) != 4) {
            return 0;
         }
         *db = a3;
         *(db + 1) = a2;
         *(db + 2) = a1;
         *(db + 3) = a0;
         return 1;
      }
      
#endif /* CS_COMMON_PLATFORMS_SIMPLELINK_SL_SOCKET_C_ */
#ifdef MG_MODULE_LINES
#line 1 "./src/../../common/platforms/simplelink/sl_mg_task.c"
#endif
#if defined(MG_SOCKET_SIMPLELINK)
      
      /* Amalgamated: #include "mg_task.h" */
      
#include <oslib/osi.h>
      
      enum mg_q_msg_type {
         MG_Q_MSG_CB,
      };
      struct mg_q_msg {
         enum mg_q_msg_type type;
         void (*cb)(struct mg_mgr *mgr, void *arg);
         void *arg;
      };
      static OsiMsgQ_t s_mg_q;
      static void mg_task(void *arg);
      
      bool mg_start_task(int priority, int stack_size, mg_init_cb mg_init) {
         if (osi_MsgQCreate(&s_mg_q, "MG", sizeof(struct mg_q_msg), 16) != OSI_OK) {
            return false;
         }
         if (osi_TaskCreate(mg_task, (const signed char *) "MG", stack_size,
                            (void *) mg_init, priority, NULL) != OSI_OK) {
            return false;
         }
         return true;
      }
      
      static void mg_task(void *arg) {
         struct mg_mgr mgr;
         mg_init_cb mg_init = (mg_init_cb) arg;
         mg_mgr_init(&mgr, NULL);
         mg_init(&mgr);
         while (1) {
            struct mg_q_msg msg;
            mg_mgr_poll(&mgr, 1);
            if (osi_MsgQRead(&s_mg_q, &msg, 1) != OSI_OK) continue;
            switch (msg.type) {
               case MG_Q_MSG_CB: {
                  msg.cb(&mgr, msg.arg);
               }
            }
         }
      }
      
      void mg_run_in_task(void (*cb)(struct mg_mgr *mgr, void *arg), void *cb_arg) {
         struct mg_q_msg msg = {MG_Q_MSG_CB, cb, cb_arg};
         osi_MsgQWrite(&s_mg_q, &msg, OSI_NO_WAIT);
      }
      
#endif /* defined(MG_SOCKET_SIMPLELINK) */