// Copyright (c) 2004-2013 Sergey Lyubka // 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 . // // 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 . #if defined(_WIN32) #if !defined(_CRT_SECURE_NO_WARNINGS) #define _CRT_SECURE_NO_WARNINGS // Disable deprecation warning in VS2005 #endif #else #ifdef __linux__ #define _XOPEN_SOURCE 600 // For flockfile() on Linux #endif #if !defined(_LARGEFILE_SOURCE) #define _LARGEFILE_SOURCE // Enable 64-bit file offsets #endif #define __STDC_FORMAT_MACROS // wants this for C++ #define __STDC_LIMIT_MACROS // C++ wants that for INT64_MAX #endif #if defined (_MSC_VER) // conditional expression is constant: introduced by FD_SET(..) #pragma warning (disable : 4127) // non-constant aggregate initializer: issued due to missing C99 support #pragma warning (disable : 4204) #endif // Disable WIN32_LEAN_AND_MEAN. // This makes windows.h always include winsock2.h #ifdef WIN32_LEAN_AND_MEAN #undef WIN32_LEAN_AND_MEAN #endif #if defined(__SYMBIAN32__) #define NO_SSL // SSL is not supported #define NO_CGI // CGI is not supported #define PATH_MAX FILENAME_MAX #endif // __SYMBIAN32__ #ifndef _WIN32_WCE // Some ANSI #includes are not available on Windows CE #include #include #include #include #include #endif // !_WIN32_WCE #include #include #include #include #include #include #include #include #include #if defined(_WIN32) && !defined(__SYMBIAN32__) // Windows specific #undef _WIN32_WINNT #define _WIN32_WINNT 0x0400 // To make it link in VS2005 #include #ifndef PATH_MAX #define PATH_MAX MAX_PATH #endif #ifndef _WIN32_WCE #include #include #include #else // _WIN32_WCE #define NO_CGI // WinCE has no pipes typedef long off_t; #define errno GetLastError() #define strerror(x) _ultoa(x, (char *) _alloca(sizeof(x) *3 ), 10) #endif // _WIN32_WCE #define MAKEUQUAD(lo, hi) ((uint64_t)(((uint32_t)(lo)) | \ ((uint64_t)((uint32_t)(hi))) << 32)) #define RATE_DIFF 10000000 // 100 nsecs #define EPOCH_DIFF MAKEUQUAD(0xd53e8000, 0x019db1de) #define SYS2UNIX_TIME(lo, hi) \ (time_t) ((MAKEUQUAD((lo), (hi)) - EPOCH_DIFF) / RATE_DIFF) // Visual Studio 6 does not know __func__ or __FUNCTION__ // The rest of MS compilers use __FUNCTION__, not C99 __func__ // Also use _strtoui64 on modern M$ compilers #if defined(_MSC_VER) && _MSC_VER < 1300 #define STRX(x) #x #define STR(x) STRX(x) #define __func__ __FILE__ ":" STR(__LINE__) #define strtoull(x, y, z) (unsigned __int64) _atoi64(x) #define strtoll(x, y, z) _atoi64(x) #else #define __func__ __FUNCTION__ #define strtoull(x, y, z) _strtoui64(x, y, z) #define strtoll(x, y, z) _strtoi64(x, y, z) #endif // _MSC_VER #define ERRNO GetLastError() #define NO_SOCKLEN_T #define SSL_LIB "ssleay32.dll" #define CRYPTO_LIB "libeay32.dll" #define O_NONBLOCK 0 #if !defined(EWOULDBLOCK) #define EWOULDBLOCK WSAEWOULDBLOCK #endif // !EWOULDBLOCK #define _POSIX_ #define INT64_FMT "I64d" #define WINCDECL __cdecl #define SHUT_WR 1 #define snprintf _snprintf #define vsnprintf _vsnprintf #define mg_sleep(x) Sleep(x) #define pipe(x) _pipe(x, MG_BUF_LEN, _O_BINARY) #ifndef popen #define popen(x, y) _popen(x, y) #endif #ifndef pclose #define pclose(x) _pclose(x) #endif #define close(x) _close(x) #define dlsym(x,y) GetProcAddress((HINSTANCE) (x), (y)) #define RTLD_LAZY 0 #define fseeko(x, y, z) _lseeki64(_fileno(x), (y), (z)) #define fdopen(x, y) _fdopen((x), (y)) #define write(x, y, z) _write((x), (y), (unsigned) z) #define read(x, y, z) _read((x), (y), (unsigned) z) #define flockfile(x) #define funlockfile(x) #define sleep(x) Sleep((x) * 1000) #define rmdir(x) _rmdir(x) #if !defined(va_copy) #define va_copy(x, y) x = y #endif // !va_copy MINGW #defines va_copy #if !defined(fileno) #define fileno(x) _fileno(x) #endif // !fileno MINGW #defines fileno typedef HANDLE pthread_mutex_t; typedef struct {HANDLE signal, broadcast;} pthread_cond_t; typedef DWORD pthread_t; #define pid_t HANDLE // MINGW typedefs pid_t to int. Using #define here. static int pthread_mutex_lock(pthread_mutex_t *); static int pthread_mutex_unlock(pthread_mutex_t *); static void to_unicode(const char *path, wchar_t *wbuf, size_t wbuf_len); struct file; static char *mg_fgets(char *buf, size_t size, struct file *filep, char **p); #if defined(HAVE_STDINT) #include #else typedef unsigned int uint32_t; typedef unsigned short uint16_t; typedef unsigned __int64 uint64_t; typedef __int64 int64_t; #define INT64_MAX 9223372036854775807 #endif // HAVE_STDINT // POSIX dirent interface struct dirent { char d_name[PATH_MAX]; }; typedef struct DIR { HANDLE handle; WIN32_FIND_DATAW info; struct dirent result; } DIR; #ifndef HAVE_POLL struct pollfd { SOCKET fd; short events; short revents; }; #define POLLIN 1 #endif // Mark required libraries #ifdef _MSC_VER #pragma comment(lib, "Ws2_32.lib") #endif #else // UNIX specific #include #include #include #include #include #include #include #include #include #include #include #include #if !defined(NO_SSL_DL) && !defined(NO_SSL) #include #endif #include #if defined(__MACH__) #define SSL_LIB "libssl.dylib" #define CRYPTO_LIB "libcrypto.dylib" #else #if !defined(SSL_LIB) #define SSL_LIB "libssl.so" #endif #if !defined(CRYPTO_LIB) #define CRYPTO_LIB "libcrypto.so" #endif #endif #ifndef O_BINARY #define O_BINARY 0 #endif // O_BINARY #define closesocket(a) close(a) #define mg_mkdir(x, y) mkdir(x, y) #define mg_remove(x) remove(x) #define mg_sleep(x) usleep((x) * 1000) #define ERRNO errno #define INVALID_SOCKET (-1) #define INT64_FMT PRId64 typedef int SOCKET; #define WINCDECL #endif // End of Windows and UNIX specific includes #include "mongoose.h" #define MONGOOSE_VERSION "4.1" #define PASSWORDS_FILE_NAME ".htpasswd" #define CGI_ENVIRONMENT_SIZE 4096 #define MAX_CGI_ENVIR_VARS 64 #define MG_BUF_LEN 8192 #define MAX_REQUEST_SIZE 16384 #define ARRAY_SIZE(array) (sizeof(array) / sizeof(array[0])) #ifdef _WIN32 static pthread_t pthread_self(void) { return GetCurrentThreadId(); } #endif // _WIN32 #ifdef DEBUG_TRACE #undef DEBUG_TRACE #define DEBUG_TRACE(x) #else #if defined(DEBUG) #define DEBUG_TRACE(x) do { \ flockfile(stdout); \ printf("*** %lu.%p.%s.%d: ", \ (unsigned long) time(NULL), (void *) pthread_self(), \ __func__, __LINE__); \ printf x; \ putchar('\n'); \ fflush(stdout); \ funlockfile(stdout); \ } while (0) #else #define DEBUG_TRACE(x) #endif // DEBUG #endif // DEBUG_TRACE // Darwin prior to 7.0 and Win32 do not have socklen_t #ifdef NO_SOCKLEN_T typedef int socklen_t; #endif // NO_SOCKLEN_T #define _DARWIN_UNLIMITED_SELECT #define IP_ADDR_STR_LEN 50 // IPv6 hex string is 46 chars #if !defined(MSG_NOSIGNAL) #define MSG_NOSIGNAL 0 #endif #if !defined(SOMAXCONN) #define SOMAXCONN 100 #endif #if !defined(PATH_MAX) #define PATH_MAX 4096 #endif // Size of the accepted socket queue #if !defined(MGSQLEN) #define MGSQLEN 20 #endif // Extra HTTP headers to send in every static file reply #if !defined(EXTRA_HTTP_HEADERS) #define EXTRA_HTTP_HEADERS "" #endif static const char *http_500_error = "Internal Server Error"; #if defined(NO_SSL_DL) #include #include #else // SSL loaded dynamically from DLL. // I put the prototypes here to be independent from OpenSSL source installation. typedef struct ssl_st SSL; typedef struct ssl_method_st SSL_METHOD; typedef struct ssl_ctx_st SSL_CTX; struct ssl_func { const char *name; // SSL function name void (*ptr)(void); // Function pointer }; #define SSL_free (* (void (*)(SSL *)) ssl_sw[0].ptr) #define SSL_accept (* (int (*)(SSL *)) ssl_sw[1].ptr) #define SSL_connect (* (int (*)(SSL *)) ssl_sw[2].ptr) #define SSL_read (* (int (*)(SSL *, void *, int)) ssl_sw[3].ptr) #define SSL_write (* (int (*)(SSL *, const void *,int)) ssl_sw[4].ptr) #define SSL_get_error (* (int (*)(SSL *, int)) ssl_sw[5].ptr) #define SSL_set_fd (* (int (*)(SSL *, SOCKET)) ssl_sw[6].ptr) #define SSL_new (* (SSL * (*)(SSL_CTX *)) ssl_sw[7].ptr) #define SSL_CTX_new (* (SSL_CTX * (*)(SSL_METHOD *)) ssl_sw[8].ptr) #define SSLv23_server_method (* (SSL_METHOD * (*)(void)) ssl_sw[9].ptr) #define SSL_library_init (* (int (*)(void)) ssl_sw[10].ptr) #define SSL_CTX_use_PrivateKey_file (* (int (*)(SSL_CTX *, \ const char *, int)) ssl_sw[11].ptr) #define SSL_CTX_use_certificate_file (* (int (*)(SSL_CTX *, \ const char *, int)) ssl_sw[12].ptr) #define SSL_CTX_set_default_passwd_cb \ (* (void (*)(SSL_CTX *, mg_callback_t)) ssl_sw[13].ptr) #define SSL_CTX_free (* (void (*)(SSL_CTX *)) ssl_sw[14].ptr) #define SSL_load_error_strings (* (void (*)(void)) ssl_sw[15].ptr) #define SSL_CTX_use_certificate_chain_file \ (* (int (*)(SSL_CTX *, const char *)) ssl_sw[16].ptr) #define SSLv23_client_method (* (SSL_METHOD * (*)(void)) ssl_sw[17].ptr) #define SSL_pending (* (int (*)(SSL *)) ssl_sw[18].ptr) #define SSL_CTX_set_verify (* (void (*)(SSL_CTX *, int, int)) ssl_sw[19].ptr) #define SSL_shutdown (* (int (*)(SSL *)) ssl_sw[20].ptr) #define CRYPTO_num_locks (* (int (*)(void)) crypto_sw[0].ptr) #define CRYPTO_set_locking_callback \ (* (void (*)(void (*)(int, int, const char *, int))) crypto_sw[1].ptr) #define CRYPTO_set_id_callback \ (* (void (*)(unsigned long (*)(void))) crypto_sw[2].ptr) #define ERR_get_error (* (unsigned long (*)(void)) crypto_sw[3].ptr) #define ERR_error_string (* (char * (*)(unsigned long,char *)) crypto_sw[4].ptr) // set_ssl_option() function updates this array. // It loads SSL library dynamically and changes NULLs to the actual addresses // of respective functions. The macros above (like SSL_connect()) are really // just calling these functions indirectly via the pointer. static struct ssl_func ssl_sw[] = { {"SSL_free", NULL}, {"SSL_accept", NULL}, {"SSL_connect", NULL}, {"SSL_read", NULL}, {"SSL_write", NULL}, {"SSL_get_error", NULL}, {"SSL_set_fd", NULL}, {"SSL_new", NULL}, {"SSL_CTX_new", NULL}, {"SSLv23_server_method", NULL}, {"SSL_library_init", NULL}, {"SSL_CTX_use_PrivateKey_file", NULL}, {"SSL_CTX_use_certificate_file",NULL}, {"SSL_CTX_set_default_passwd_cb",NULL}, {"SSL_CTX_free", NULL}, {"SSL_load_error_strings", NULL}, {"SSL_CTX_use_certificate_chain_file", NULL}, {"SSLv23_client_method", NULL}, {"SSL_pending", NULL}, {"SSL_CTX_set_verify", NULL}, {"SSL_shutdown", NULL}, {NULL, NULL} }; // Similar array as ssl_sw. These functions could be located in different lib. #if !defined(NO_SSL) static struct ssl_func crypto_sw[] = { {"CRYPTO_num_locks", NULL}, {"CRYPTO_set_locking_callback", NULL}, {"CRYPTO_set_id_callback", NULL}, {"ERR_get_error", NULL}, {"ERR_error_string", NULL}, {NULL, NULL} }; #endif // NO_SSL #endif // NO_SSL_DL static const char *month_names[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; // Unified socket address. For IPv6 support, add IPv6 address structure // in the union u. union usa { struct sockaddr sa; struct sockaddr_in sin; #if defined(USE_IPV6) struct sockaddr_in6 sin6; #endif }; // Describes a string (chunk of memory). struct vec { const char *ptr; size_t len; }; struct file { int is_directory; time_t modification_time; int64_t size; FILE *fp; const char *membuf; // Non-NULL if file data is in memory // set to 1 if the content is gzipped // in which case we need a content-encoding: gzip header int gzipped; }; #define STRUCT_FILE_INITIALIZER {0, 0, 0, NULL, NULL, 0} // Describes listening socket, or socket which was accept()-ed by the master // thread and queued for future handling by the worker thread. struct socket { SOCKET sock; // Listening socket union usa lsa; // Local socket address union usa rsa; // Remote socket address unsigned is_ssl:1; // Is port SSL-ed unsigned ssl_redir:1; // Is port supposed to redirect everything to SSL port }; // NOTE(lsm): this enum shoulds be in sync with the config_options below. enum { CGI_EXTENSIONS, CGI_ENVIRONMENT, PUT_DELETE_PASSWORDS_FILE, CGI_INTERPRETER, PROTECT_URI, AUTHENTICATION_DOMAIN, SSI_EXTENSIONS, THROTTLE, ACCESS_LOG_FILE, ENABLE_DIRECTORY_LISTING, ERROR_LOG_FILE, GLOBAL_PASSWORDS_FILE, INDEX_FILES, ENABLE_KEEP_ALIVE, ACCESS_CONTROL_LIST, EXTRA_MIME_TYPES, LISTENING_PORTS, DOCUMENT_ROOT, SSL_CERTIFICATE, NUM_THREADS, RUN_AS_USER, REWRITE, HIDE_FILES, REQUEST_TIMEOUT, NUM_OPTIONS }; static const char *config_options[] = { "cgi_pattern", "**.cgi$|**.pl$|**.php$", "cgi_environment", NULL, "put_delete_auth_file", NULL, "cgi_interpreter", NULL, "protect_uri", NULL, "authentication_domain", "mydomain.com", "ssi_pattern", "**.shtml$|**.shtm$", "throttle", NULL, "access_log_file", NULL, "enable_directory_listing", "yes", "error_log_file", NULL, "global_auth_file", NULL, "index_files", "index.html,index.htm,index.cgi,index.shtml,index.php,index.lp", "enable_keep_alive", "no", "access_control_list", NULL, "extra_mime_types", NULL, "listening_ports", "8080", "document_root", NULL, "ssl_certificate", NULL, "num_threads", "50", "run_as_user", NULL, "url_rewrite_patterns", NULL, "hide_files_patterns", NULL, "request_timeout_ms", "30000", NULL }; struct mg_context { volatile int stop_flag; // Should we stop event loop SSL_CTX *ssl_ctx; // SSL context char *config[NUM_OPTIONS]; // Mongoose configuration parameters struct mg_callbacks callbacks; // User-defined callback function void *user_data; // User-defined data struct socket *listening_sockets; int num_listening_sockets; volatile int num_threads; // Number of threads pthread_mutex_t mutex; // Protects (max|num)_threads pthread_cond_t cond; // Condvar for tracking workers terminations struct socket queue[MGSQLEN]; // Accepted sockets volatile int sq_head; // Head of the socket queue volatile int sq_tail; // Tail of the socket queue pthread_cond_t sq_full; // Signaled when socket is produced pthread_cond_t sq_empty; // Signaled when socket is consumed }; struct mg_connection { struct mg_request_info request_info; struct mg_context *ctx; SSL *ssl; // SSL descriptor SSL_CTX *client_ssl_ctx; // SSL context for client connections struct socket client; // Connected client time_t birth_time; // Time when request was received int64_t num_bytes_sent; // Total bytes sent to client int64_t content_len; // Content-Length header value int64_t consumed_content; // How many bytes of content have been read char *buf; // Buffer for received data char *path_info; // PATH_INFO part of the URL int must_close; // 1 if connection must be closed int buf_size; // Buffer size int request_len; // Size of the request + headers in a buffer int data_len; // Total size of data in a buffer int status_code; // HTTP reply status code, e.g. 200 int throttle; // Throttling, bytes/sec. <= 0 means no throttle time_t last_throttle_time; // Last time throttled data was sent int64_t last_throttle_bytes;// Bytes sent this second }; // Directory entry struct de { struct mg_connection *conn; char *file_name; struct file file; }; const char **mg_get_valid_option_names(void) { return config_options; } static int is_file_in_memory(struct mg_connection *conn, const char *path, struct file *filep) { size_t size = 0; if ((filep->membuf = conn->ctx->callbacks.open_file == NULL ? NULL : conn->ctx->callbacks.open_file(conn, path, &size)) != NULL) { // NOTE: override filep->size only on success. Otherwise, it might break // constructs like if (!mg_stat() || !mg_fopen()) ... filep->size = size; } return filep->membuf != NULL; } static int is_file_opened(const struct file *filep) { return filep->membuf != NULL || filep->fp != NULL; } static int mg_fopen(struct mg_connection *conn, const char *path, const char *mode, struct file *filep) { if (!is_file_in_memory(conn, path, filep)) { #ifdef _WIN32 wchar_t wbuf[PATH_MAX], wmode[20]; to_unicode(path, wbuf, ARRAY_SIZE(wbuf)); MultiByteToWideChar(CP_UTF8, 0, mode, -1, wmode, ARRAY_SIZE(wmode)); filep->fp = _wfopen(wbuf, wmode); #else filep->fp = fopen(path, mode); #endif } return is_file_opened(filep); } static void mg_fclose(struct file *filep) { if (filep != NULL && filep->fp != NULL) { fclose(filep->fp); } } static int get_option_index(const char *name) { int i; for (i = 0; config_options[i * 2] != NULL; i++) { if (strcmp(config_options[i * 2], name) == 0) { return i; } } return -1; } const char *mg_get_option(const struct mg_context *ctx, const char *name) { int i; if ((i = get_option_index(name)) == -1) { return NULL; } else if (ctx->config[i] == NULL) { return ""; } else { return ctx->config[i]; } } static void sockaddr_to_string(char *buf, size_t len, const union usa *usa) { buf[0] = '\0'; #if defined(USE_IPV6) inet_ntop(usa->sa.sa_family, usa->sa.sa_family == AF_INET ? (void *) &usa->sin.sin_addr : (void *) &usa->sin6.sin6_addr, buf, len); #elif defined(_WIN32) // Only Windoze Vista (and newer) have inet_ntop() strncpy(buf, inet_ntoa(usa->sin.sin_addr), len); #else inet_ntop(usa->sa.sa_family, (void *) &usa->sin.sin_addr, buf, len); #endif } static void cry(struct mg_connection *conn, PRINTF_FORMAT_STRING(const char *fmt), ...) PRINTF_ARGS(2, 3); // Print error message to the opened error log stream. static void cry(struct mg_connection *conn, const char *fmt, ...) { char buf[MG_BUF_LEN], src_addr[IP_ADDR_STR_LEN]; va_list ap; FILE *fp; time_t timestamp; va_start(ap, fmt); (void) vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); // Do not lock when getting the callback value, here and below. // I suppose this is fine, since function cannot disappear in the // same way string option can. if (conn->ctx->callbacks.log_message == NULL || conn->ctx->callbacks.log_message(conn, buf) == 0) { fp = conn->ctx == NULL || conn->ctx->config[ERROR_LOG_FILE] == NULL ? NULL : fopen(conn->ctx->config[ERROR_LOG_FILE], "a+"); if (fp != NULL) { flockfile(fp); timestamp = time(NULL); sockaddr_to_string(src_addr, sizeof(src_addr), &conn->client.rsa); fprintf(fp, "[%010lu] [error] [client %s] ", (unsigned long) timestamp, src_addr); if (conn->request_info.request_method != NULL) { fprintf(fp, "%s %s: ", conn->request_info.request_method, conn->request_info.uri); } fprintf(fp, "%s", buf); fputc('\n', fp); funlockfile(fp); fclose(fp); } } } // Return fake connection structure. Used for logging, if connection // is not applicable at the moment of logging. static struct mg_connection *fc(struct mg_context *ctx) { static struct mg_connection fake_connection; fake_connection.ctx = ctx; return &fake_connection; } const char *mg_version(void) { return MONGOOSE_VERSION; } struct mg_request_info *mg_get_request_info(struct mg_connection *conn) { return &conn->request_info; } static void mg_strlcpy(register char *dst, register const char *src, size_t n) { for (; *src != '\0' && n > 1; n--) { *dst++ = *src++; } *dst = '\0'; } static int lowercase(const char *s) { return tolower(* (const unsigned char *) s); } static int mg_strncasecmp(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; } static int mg_strcasecmp(const char *s1, const char *s2) { int diff; do { diff = lowercase(s1++) - lowercase(s2++); } while (diff == 0 && s1[-1] != '\0'); return diff; } static char * mg_strndup(const char *ptr, size_t len) { char *p; if ((p = (char *) malloc(len + 1)) != NULL) { mg_strlcpy(p, ptr, len + 1); } return p; } static char * mg_strdup(const char *str) { return mg_strndup(str, strlen(str)); } static const char *mg_strcasestr(const char *big_str, const char *small_str) { int i, big_len = strlen(big_str), small_len = strlen(small_str); for (i = 0; i <= big_len - small_len; i++) { if (mg_strncasecmp(big_str + i, small_str, small_len) == 0) { return big_str + i; } } return NULL; } // Like snprintf(), but never returns negative value, or a value // that is larger than a supplied buffer. // Thanks to Adam Zeldis to pointing snprintf()-caused vulnerability // in his audit report. static int mg_vsnprintf(struct mg_connection *conn, char *buf, size_t buflen, const char *fmt, va_list ap) { int n; if (buflen == 0) return 0; n = vsnprintf(buf, buflen, fmt, ap); if (n < 0) { cry(conn, "vsnprintf error"); n = 0; } else if (n >= (int) buflen) { cry(conn, "truncating vsnprintf buffer: [%.*s]", n > 200 ? 200 : n, buf); n = (int) buflen - 1; } buf[n] = '\0'; return n; } static int mg_snprintf(struct mg_connection *conn, char *buf, size_t buflen, PRINTF_FORMAT_STRING(const char *fmt), ...) PRINTF_ARGS(4, 5); static int mg_snprintf(struct mg_connection *conn, char *buf, size_t buflen, const char *fmt, ...) { va_list ap; int n; va_start(ap, fmt); n = mg_vsnprintf(conn, buf, buflen, fmt, ap); va_end(ap); return n; } // Skip the characters until one of the delimiters characters found. // 0-terminate resulting word. Skip the delimiter and following whitespaces. // Advance pointer to buffer to the next word. Return found 0-terminated word. // Delimiters can be quoted with quotechar. static char *skip_quoted(char **buf, const char *delimiters, const char *whitespace, char quotechar) { char *p, *begin_word, *end_word, *end_whitespace; begin_word = *buf; end_word = begin_word + strcspn(begin_word, delimiters); // Check for quotechar if (end_word > begin_word) { p = end_word - 1; while (*p == quotechar) { // If there is anything beyond end_word, copy it if (*end_word == '\0') { *p = '\0'; break; } else { size_t end_off = strcspn(end_word + 1, delimiters); memmove (p, end_word, end_off + 1); p += end_off; // p must correspond to end_word - 1 end_word += end_off + 1; } } for (p++; p < end_word; p++) { *p = '\0'; } } if (*end_word == '\0') { *buf = end_word; } else { end_whitespace = end_word + 1 + strspn(end_word + 1, whitespace); for (p = end_word; p < end_whitespace; p++) { *p = '\0'; } *buf = end_whitespace; } return begin_word; } // Simplified version of skip_quoted without quote char // and whitespace == delimiters static char *skip(char **buf, const char *delimiters) { return skip_quoted(buf, delimiters, delimiters, 0); } // Return HTTP header value, or NULL if not found. static const char *get_header(const struct mg_request_info *ri, const char *name) { int i; for (i = 0; i < ri->num_headers; i++) if (!mg_strcasecmp(name, ri->http_headers[i].name)) return ri->http_headers[i].value; return NULL; } const char *mg_get_header(const struct mg_connection *conn, const char *name) { return get_header(&conn->request_info, name); } // A helper function for traversing a comma separated list of values. // It returns a list pointer shifted to the next value, or NULL if the end // of the list found. // Value is stored in val vector. If value has form "x=y", then eq_val // vector is initialized to point to the "y" part, and val vector length // is adjusted to point only to "x". static const char *next_option(const char *list, struct vec *val, struct vec *eq_val) { if (list == NULL || *list == '\0') { // End of the list list = NULL; } else { val->ptr = list; if ((list = strchr(val->ptr, ',')) != NULL) { // Comma found. Store length and shift the list ptr val->len = list - val->ptr; list++; } else { // This value is the last one list = val->ptr + strlen(val->ptr); val->len = list - val->ptr; } 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->ptr = (const char *) memchr(val->ptr, '=', val->len); if (eq_val->ptr != NULL) { eq_val->ptr++; // Skip over '=' character eq_val->len = val->ptr + val->len - eq_val->ptr; val->len = (eq_val->ptr - val->ptr) - 1; } } } return list; } // Perform case-insensitive match of string against pattern static int match_prefix(const char *pattern, int pattern_len, const char *str) { const char *or_str; int i, j, len, res; if ((or_str = (const char *) memchr(pattern, '|', pattern_len)) != NULL) { res = match_prefix(pattern, or_str - pattern, str); return res > 0 ? res : match_prefix(or_str + 1, (pattern + pattern_len) - (or_str + 1), str); } i = j = 0; res = -1; for (; i < pattern_len; i++, j++) { if (pattern[i] == '?' && str[j] != '\0') { continue; } else if (pattern[i] == '$') { return str[j] == '\0' ? j : -1; } else if (pattern[i] == '*') { i++; if (pattern[i] == '*') { i++; len = (int) strlen(str + j); } else { len = (int) strcspn(str + j, "/"); } if (i == pattern_len) { return j + len; } do { res = match_prefix(pattern + i, pattern_len - i, str + j + len); } while (res == -1 && len-- > 0); return res == -1 ? -1 : j + res + len; } else if (lowercase(&pattern[i]) != lowercase(&str[j])) { return -1; } } return j; } // HTTP 1.1 assumes keep alive if "Connection:" header is not set // This function must tolerate situations when connection info is not // set up, for example if request parsing failed. static int should_keep_alive(const struct mg_connection *conn) { const char *http_version = conn->request_info.http_version; const char *header = mg_get_header(conn, "Connection"); if (conn->must_close || conn->status_code == 401 || mg_strcasecmp(conn->ctx->config[ENABLE_KEEP_ALIVE], "yes") != 0 || (header != NULL && mg_strcasecmp(header, "keep-alive") != 0) || (header == NULL && http_version && strcmp(http_version, "1.1"))) { return 0; } return 1; } static const char *suggest_connection_header(const struct mg_connection *conn) { return should_keep_alive(conn) ? "keep-alive" : "close"; } static void send_http_error(struct mg_connection *, int, const char *, PRINTF_FORMAT_STRING(const char *fmt), ...) PRINTF_ARGS(4, 5); static void send_http_error(struct mg_connection *conn, int status, const char *reason, const char *fmt, ...) { char buf[MG_BUF_LEN]; va_list ap; int len = 0; conn->status_code = status; buf[0] = '\0'; // Errors 1xx, 204 and 304 MUST NOT send a body if (status > 199 && status != 204 && status != 304) { len = mg_snprintf(conn, buf, sizeof(buf), "Error %d: %s", status, reason); buf[len++] = '\n'; va_start(ap, fmt); len += mg_vsnprintf(conn, buf + len, sizeof(buf) - len, fmt, ap); va_end(ap); } DEBUG_TRACE(("[%s]", buf)); mg_printf(conn, "HTTP/1.1 %d %s\r\n" "Content-Length: %d\r\n" "Connection: %s\r\n\r\n", status, reason, len, suggest_connection_header(conn)); conn->num_bytes_sent += mg_printf(conn, "%s", buf); } #if defined(_WIN32) && !defined(__SYMBIAN32__) static int pthread_mutex_init(pthread_mutex_t *mutex, void *unused) { (void) unused; *mutex = CreateMutex(NULL, FALSE, NULL); return *mutex == NULL ? -1 : 0; } static int pthread_mutex_destroy(pthread_mutex_t *mutex) { return CloseHandle(*mutex) == 0 ? -1 : 0; } static int pthread_mutex_lock(pthread_mutex_t *mutex) { return WaitForSingleObject(*mutex, INFINITE) == WAIT_OBJECT_0? 0 : -1; } static int pthread_mutex_unlock(pthread_mutex_t *mutex) { return ReleaseMutex(*mutex) == 0 ? -1 : 0; } static int pthread_cond_init(pthread_cond_t *cv, const void *unused) { (void) unused; cv->signal = CreateEvent(NULL, FALSE, FALSE, NULL); cv->broadcast = CreateEvent(NULL, TRUE, FALSE, NULL); return cv->signal != NULL && cv->broadcast != NULL ? 0 : -1; } static int pthread_cond_wait(pthread_cond_t *cv, pthread_mutex_t *mutex) { HANDLE handles[] = {cv->signal, cv->broadcast}; ReleaseMutex(*mutex); WaitForMultipleObjects(2, handles, FALSE, INFINITE); return WaitForSingleObject(*mutex, INFINITE) == WAIT_OBJECT_0? 0 : -1; } static int pthread_cond_signal(pthread_cond_t *cv) { return SetEvent(cv->signal) == 0 ? -1 : 0; } static int pthread_cond_broadcast(pthread_cond_t *cv) { // Implementation with PulseEvent() has race condition, see // http://www.cs.wustl.edu/~schmidt/win32-cv-1.html return PulseEvent(cv->broadcast) == 0 ? -1 : 0; } static int pthread_cond_destroy(pthread_cond_t *cv) { return CloseHandle(cv->signal) && CloseHandle(cv->broadcast) ? 0 : -1; } // For Windows, change all slashes to backslashes in path names. static void change_slashes_to_backslashes(char *path) { int i; for (i = 0; path[i] != '\0'; i++) { if (path[i] == '/') path[i] = '\\'; // i > 0 check is to preserve UNC paths, like \\server\file.txt if (path[i] == '\\' && i > 0) while (path[i + 1] == '\\' || path[i + 1] == '/') (void) memmove(path + i + 1, path + i + 2, strlen(path + i + 1)); } } // Encode 'path' which is assumed UTF-8 string, into UNICODE string. // wbuf and wbuf_len is a target buffer and its length. static void to_unicode(const char *path, wchar_t *wbuf, size_t wbuf_len) { char buf[PATH_MAX], buf2[PATH_MAX]; mg_strlcpy(buf, path, sizeof(buf)); change_slashes_to_backslashes(buf); // Convert to Unicode and back. If doubly-converted string does not // match the original, something is fishy, reject. memset(wbuf, 0, wbuf_len * sizeof(wchar_t)); MultiByteToWideChar(CP_UTF8, 0, buf, -1, wbuf, (int) wbuf_len); WideCharToMultiByte(CP_UTF8, 0, wbuf, (int) wbuf_len, buf2, sizeof(buf2), NULL, NULL); if (strcmp(buf, buf2) != 0) { wbuf[0] = L'\0'; } } #if defined(_WIN32_WCE) static time_t time(time_t *ptime) { time_t t; SYSTEMTIME st; FILETIME ft; GetSystemTime(&st); SystemTimeToFileTime(&st, &ft); t = SYS2UNIX_TIME(ft.dwLowDateTime, ft.dwHighDateTime); if (ptime != NULL) { *ptime = t; } return t; } static struct tm *localtime(const time_t *ptime, struct tm *ptm) { int64_t t = ((int64_t) *ptime) * RATE_DIFF + EPOCH_DIFF; FILETIME ft, lft; SYSTEMTIME st; TIME_ZONE_INFORMATION tzinfo; if (ptm == NULL) { return NULL; } * (int64_t *) &ft = t; FileTimeToLocalFileTime(&ft, &lft); FileTimeToSystemTime(&lft, &st); ptm->tm_year = st.wYear - 1900; ptm->tm_mon = st.wMonth - 1; ptm->tm_wday = st.wDayOfWeek; ptm->tm_mday = st.wDay; ptm->tm_hour = st.wHour; ptm->tm_min = st.wMinute; ptm->tm_sec = st.wSecond; ptm->tm_yday = 0; // hope nobody uses this ptm->tm_isdst = GetTimeZoneInformation(&tzinfo) == TIME_ZONE_ID_DAYLIGHT ? 1 : 0; return ptm; } static struct tm *gmtime(const time_t *ptime, struct tm *ptm) { // FIXME(lsm): fix this. return localtime(ptime, ptm); } static size_t strftime(char *dst, size_t dst_size, const char *fmt, const struct tm *tm) { (void) snprintf(dst, dst_size, "implement strftime() for WinCE"); return 0; } #endif // Windows happily opens files with some garbage at the end of file name. // For example, fopen("a.cgi ", "r") on Windows successfully opens // "a.cgi", despite one would expect an error back. // This function returns non-0 if path ends with some garbage. static int path_cannot_disclose_cgi(const char *path) { static const char *allowed_last_characters = "_-"; int last = path[strlen(path) - 1]; return isalnum(last) || strchr(allowed_last_characters, last) != NULL; } static int mg_stat(struct mg_connection *conn, const char *path, struct file *filep) { wchar_t wbuf[PATH_MAX]; WIN32_FILE_ATTRIBUTE_DATA info; if (!is_file_in_memory(conn, path, filep)) { to_unicode(path, wbuf, ARRAY_SIZE(wbuf)); if (GetFileAttributesExW(wbuf, GetFileExInfoStandard, &info) != 0) { filep->size = MAKEUQUAD(info.nFileSizeLow, info.nFileSizeHigh); filep->modification_time = SYS2UNIX_TIME( info.ftLastWriteTime.dwLowDateTime, info.ftLastWriteTime.dwHighDateTime); filep->is_directory = info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY; // If file name is fishy, reset the file structure and return error. // Note it is important to reset, not just return the error, cause // functions like is_file_opened() check the struct. if (!filep->is_directory && !path_cannot_disclose_cgi(path)) { memset(filep, 0, sizeof(*filep)); } } } return filep->membuf != NULL || filep->modification_time != 0; } static int mg_remove(const char *path) { wchar_t wbuf[PATH_MAX]; to_unicode(path, wbuf, ARRAY_SIZE(wbuf)); return DeleteFileW(wbuf) ? 0 : -1; } static int mg_mkdir(const char *path, int mode) { char buf[PATH_MAX]; wchar_t wbuf[PATH_MAX]; (void) mode; mg_strlcpy(buf, path, sizeof(buf)); change_slashes_to_backslashes(buf); (void) MultiByteToWideChar(CP_UTF8, 0, buf, -1, wbuf, ARRAY_SIZE(wbuf)); return CreateDirectoryW(wbuf, NULL) ? 0 : -1; } // Implementation of POSIX opendir/closedir/readdir for Windows. static DIR * opendir(const char *name) { DIR *dir = NULL; wchar_t wpath[PATH_MAX]; DWORD attrs; if (name == NULL) { SetLastError(ERROR_BAD_ARGUMENTS); } else if ((dir = (DIR *) malloc(sizeof(*dir))) == NULL) { SetLastError(ERROR_NOT_ENOUGH_MEMORY); } else { to_unicode(name, wpath, ARRAY_SIZE(wpath)); attrs = GetFileAttributesW(wpath); if (attrs != 0xFFFFFFFF && ((attrs & FILE_ATTRIBUTE_DIRECTORY) == FILE_ATTRIBUTE_DIRECTORY)) { (void) wcscat(wpath, L"\\*"); dir->handle = FindFirstFileW(wpath, &dir->info); dir->result.d_name[0] = '\0'; } else { free(dir); dir = NULL; } } return dir; } static int closedir(DIR *dir) { int result = 0; if (dir != NULL) { if (dir->handle != INVALID_HANDLE_VALUE) result = FindClose(dir->handle) ? 0 : -1; free(dir); } else { result = -1; SetLastError(ERROR_BAD_ARGUMENTS); } return result; } static struct dirent *readdir(DIR *dir) { struct dirent *result = 0; 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; } #ifndef HAVE_POLL static int poll(struct pollfd *pfd, int n, int milliseconds) { struct timeval tv; fd_set set; int i, result; SOCKET maxfd = 0; tv.tv_sec = milliseconds / 1000; tv.tv_usec = (milliseconds % 1000) * 1000; FD_ZERO(&set); for (i = 0; i < n; i++) { FD_SET((SOCKET) pfd[i].fd, &set); pfd[i].revents = 0; if (pfd[i].fd > maxfd) { maxfd = pfd[i].fd; } } if ((result = select(maxfd + 1, &set, NULL, NULL, &tv)) > 0) { for (i = 0; i < n; i++) { if (FD_ISSET(pfd[i].fd, &set)) { pfd[i].revents = POLLIN; } } } return result; } #endif // HAVE_POLL static void set_close_on_exec(SOCKET sock) { (void) SetHandleInformation((HANDLE) sock, HANDLE_FLAG_INHERIT, 0); } int mg_start_thread(mg_thread_func_t f, void *p) { return (long)_beginthread((void (__cdecl *)(void *)) f, 0, p) == -1L ? -1 : 0; } static HANDLE dlopen(const char *dll_name, int flags) { wchar_t wbuf[PATH_MAX]; (void) flags; to_unicode(dll_name, wbuf, ARRAY_SIZE(wbuf)); return LoadLibraryW(wbuf); } #if !defined(NO_CGI) #define SIGKILL 0 static int kill(pid_t pid, int sig_num) { (void) TerminateProcess(pid, sig_num); (void) CloseHandle(pid); return 0; } static void trim_trailing_whitespaces(char *s) { char *e = s + strlen(s) - 1; while (e > s && isspace(* (unsigned char *) e)) { *e-- = '\0'; } } static pid_t spawn_process(struct mg_connection *conn, const char *prog, char *envblk, char *envp[], int fdin, int fdout, const char *dir) { HANDLE me; char *p, *interp, full_interp[PATH_MAX], full_dir[PATH_MAX], cmdline[PATH_MAX], buf[PATH_MAX]; struct file file = STRUCT_FILE_INITIALIZER; STARTUPINFOA si; PROCESS_INFORMATION pi = { 0 }; (void) envp; memset(&si, 0, sizeof(si)); si.cb = sizeof(si); // TODO(lsm): redirect CGI errors to the error log file si.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW; si.wShowWindow = SW_HIDE; me = GetCurrentProcess(); DuplicateHandle(me, (HANDLE) _get_osfhandle(fdin), me, &si.hStdInput, 0, TRUE, DUPLICATE_SAME_ACCESS); DuplicateHandle(me, (HANDLE) _get_osfhandle(fdout), me, &si.hStdOutput, 0, TRUE, DUPLICATE_SAME_ACCESS); // If CGI file is a script, try to read the interpreter line interp = conn->ctx->config[CGI_INTERPRETER]; if (interp == NULL) { buf[0] = buf[1] = '\0'; // Read the first line of the script into the buffer snprintf(cmdline, sizeof(cmdline), "%s%c%s", dir, '/', prog); if (mg_fopen(conn, cmdline, "r", &file)) { p = (char *) file.membuf; mg_fgets(buf, sizeof(buf), &file, &p); mg_fclose(&file); buf[sizeof(buf) - 1] = '\0'; } if (buf[0] == '#' && buf[1] == '!') { trim_trailing_whitespaces(buf + 2); } else { buf[2] = '\0'; } interp = buf + 2; } if (interp[0] != '\0') { GetFullPathNameA(interp, sizeof(full_interp), full_interp, NULL); interp = full_interp; } GetFullPathNameA(dir, sizeof(full_dir), full_dir, NULL); mg_snprintf(conn, cmdline, sizeof(cmdline), "%s%s\"%s\\%s\"", interp, interp[0] == '\0' ? "" : " ", full_dir, prog); DEBUG_TRACE(("Running [%s]", cmdline)); if (CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, CREATE_NEW_PROCESS_GROUP, envblk, NULL, &si, &pi) == 0) { cry(conn, "%s: CreateProcess(%s): %ld", __func__, cmdline, ERRNO); pi.hProcess = (pid_t) -1; } (void) CloseHandle(si.hStdOutput); (void) CloseHandle(si.hStdInput); (void) CloseHandle(pi.hThread); return (pid_t) pi.hProcess; } #endif // !NO_CGI static int set_non_blocking_mode(SOCKET sock) { unsigned long on = 1; return ioctlsocket(sock, FIONBIO, &on); } #else static int mg_stat(struct mg_connection *conn, const char *path, struct file *filep) { struct stat st; if (!is_file_in_memory(conn, path, filep) && !stat(path, &st)) { filep->size = st.st_size; filep->modification_time = st.st_mtime; filep->is_directory = S_ISDIR(st.st_mode); } else { filep->modification_time = (time_t) 0; } return filep->membuf != NULL || filep->modification_time != (time_t) 0; } static void set_close_on_exec(int fd) { fcntl(fd, F_SETFD, FD_CLOEXEC); } int mg_start_thread(mg_thread_func_t func, void *param) { pthread_t thread_id; pthread_attr_t attr; int result; (void) pthread_attr_init(&attr); (void) pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); #if USE_STACK_SIZE > 1 // Compile-time option to control stack size, e.g. -DUSE_STACK_SIZE=16384 (void) pthread_attr_setstacksize(&attr, USE_STACK_SIZE); #endif result = pthread_create(&thread_id, &attr, func, param); pthread_attr_destroy(&attr); return result; } #ifndef NO_CGI static pid_t spawn_process(struct mg_connection *conn, const char *prog, char *envblk, char *envp[], int fdin, int fdout, const char *dir) { pid_t pid; const char *interp; (void) envblk; if ((pid = fork()) == -1) { // Parent send_http_error(conn, 500, http_500_error, "fork(): %s", strerror(ERRNO)); } else if (pid == 0) { // Child if (chdir(dir) != 0) { cry(conn, "%s: chdir(%s): %s", __func__, dir, strerror(ERRNO)); } else if (dup2(fdin, 0) == -1) { cry(conn, "%s: dup2(%d, 0): %s", __func__, fdin, strerror(ERRNO)); } else if (dup2(fdout, 1) == -1) { cry(conn, "%s: dup2(%d, 1): %s", __func__, fdout, strerror(ERRNO)); } else { // Not redirecting stderr to stdout, to avoid output being littered // with the error messages. (void) close(fdin); (void) close(fdout); // 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); interp = conn->ctx->config[CGI_INTERPRETER]; if (interp == NULL) { (void) execle(prog, prog, NULL, envp); cry(conn, "%s: execle(%s): %s", __func__, prog, strerror(ERRNO)); } else { (void) execle(interp, interp, prog, NULL, envp); cry(conn, "%s: execle(%s %s): %s", __func__, interp, prog, strerror(ERRNO)); } } exit(EXIT_FAILURE); } return pid; } #endif // !NO_CGI static int set_non_blocking_mode(SOCKET sock) { int flags; flags = fcntl(sock, F_GETFL, 0); (void) fcntl(sock, F_SETFL, flags | O_NONBLOCK); return 0; } #endif // _WIN32 // Write data to the IO channel - opened file descriptor, socket or SSL // descriptor. Return number of bytes written. static int64_t push(FILE *fp, SOCKET sock, SSL *ssl, const char *buf, int64_t len) { int64_t sent; int n, k; (void) ssl; // Get rid of warning sent = 0; while (sent < len) { // How many bytes we send in this iteration k = len - sent > INT_MAX ? INT_MAX : (int) (len - sent); #ifndef NO_SSL if (ssl != NULL) { n = SSL_write(ssl, buf + sent, k); } else #endif if (fp != NULL) { n = (int) fwrite(buf + sent, 1, (size_t) k, fp); if (ferror(fp)) n = -1; } else { n = send(sock, buf + sent, (size_t) k, MSG_NOSIGNAL); } if (n <= 0) break; sent += n; } return sent; } // Read from IO channel - opened file descriptor, socket, or SSL descriptor. // Return negative value on error, or number of bytes read on success. static int pull(FILE *fp, struct mg_connection *conn, char *buf, int len) { int nread; if (fp != NULL) { // Use read() instead of fread(), because if we're reading from the CGI // pipe, fread() may block until IO buffer is filled up. We cannot afford // to block and must pass all read bytes immediately to the client. nread = read(fileno(fp), buf, (size_t) len); #ifndef NO_SSL } else if (conn->ssl != NULL) { nread = SSL_read(conn->ssl, buf, len); #endif } else { nread = recv(conn->client.sock, buf, (size_t) len, 0); } return conn->ctx->stop_flag ? -1 : nread; } static int pull_all(FILE *fp, struct mg_connection *conn, char *buf, int len) { int n, nread = 0; while (len > 0 && conn->ctx->stop_flag == 0) { n = pull(fp, conn, buf + nread, len); if (n < 0) { nread = n; // Propagate the error break; } else if (n == 0) { break; // No more data to read } else { conn->consumed_content += n; nread += n; len -= n; } } return nread; } int mg_read(struct mg_connection *conn, void *buf, size_t len) { int n, buffered_len, nread; const char *body; // If Content-Length is not set, read until socket is closed if (conn->consumed_content == 0 && conn->content_len == 0) { conn->content_len = INT64_MAX; conn->must_close = 1; } nread = 0; if (conn->consumed_content < conn->content_len) { // Adjust number of bytes to read. int64_t to_read = conn->content_len - conn->consumed_content; if (to_read < (int64_t) len) { len = (size_t) to_read; } // Return buffered data body = conn->buf + conn->request_len + conn->consumed_content; buffered_len = &conn->buf[conn->data_len] - body; if (buffered_len > 0) { if (len < (size_t) buffered_len) { buffered_len = (int) len; } memcpy(buf, body, (size_t) buffered_len); len -= buffered_len; conn->consumed_content += buffered_len; nread += buffered_len; buf = (char *) buf + buffered_len; } // We have returned all buffered data. Read new data from the remote socket. n = pull_all(NULL, conn, (char *) buf, (int) len); nread = n >= 0 ? nread + n : n; } return nread; } int mg_write(struct mg_connection *conn, const void *buf, size_t len) { time_t now; int64_t n, total, allowed; if (conn->throttle > 0) { if ((now = time(NULL)) != conn->last_throttle_time) { conn->last_throttle_time = now; conn->last_throttle_bytes = 0; } allowed = conn->throttle - conn->last_throttle_bytes; if (allowed > (int64_t) len) { allowed = len; } if ((total = push(NULL, conn->client.sock, conn->ssl, (const char *) buf, (int64_t) allowed)) == allowed) { buf = (char *) buf + total; conn->last_throttle_bytes += total; while (total < (int64_t) len && conn->ctx->stop_flag == 0) { allowed = conn->throttle > (int64_t) len - total ? (int64_t) len - total : conn->throttle; if ((n = push(NULL, conn->client.sock, conn->ssl, (const char *) buf, (int64_t) allowed)) != allowed) { break; } sleep(1); conn->last_throttle_bytes = allowed; conn->last_throttle_time = time(NULL); buf = (char *) buf + n; total += n; } } } else { total = push(NULL, conn->client.sock, conn->ssl, (const char *) buf, (int64_t) len); } return (int) total; } // Print message to buffer. If buffer is large enough to hold the message, // return buffer. If buffer is to small, allocate large enough buffer on heap, // and return allocated buffer. static int alloc_vprintf(char **buf, size_t size, const char *fmt, va_list ap) { va_list ap_copy; int len; // Windows is not standard-compliant, and vsnprintf() returns -1 if // buffer is too small. Also, older versions of msvcrt.dll do not have // _vscprintf(). However, if size is 0, vsnprintf() behaves correctly. // Therefore, we make two passes: on first pass, get required message length. // On second pass, actually print the message. va_copy(ap_copy, ap); len = vsnprintf(NULL, 0, fmt, ap_copy); if (len > (int) size && (size = len + 1) > 0 && (*buf = (char *) malloc(size)) == NULL) { len = -1; // Allocation failed, mark failure } else { va_copy(ap_copy, ap); vsnprintf(*buf, size, fmt, ap_copy); } return len; } int mg_vprintf(struct mg_connection *conn, const char *fmt, va_list ap) { char mem[MG_BUF_LEN], *buf = mem; int len; if ((len = alloc_vprintf(&buf, sizeof(mem), fmt, ap)) > 0) { len = mg_write(conn, buf, (size_t) len); } if (buf != mem && buf != NULL) { free(buf); } return len; } int mg_printf(struct mg_connection *conn, const char *fmt, ...) { va_list ap; va_start(ap, fmt); return mg_vprintf(conn, fmt, ap); } int mg_chunked_printf(struct mg_connection *conn, const char *fmt, ...) { char mem[MG_BUF_LEN], *buf = mem; int len; va_list ap; va_start(ap, fmt); if ((len = alloc_vprintf(&buf, sizeof(mem), fmt, ap)) > 0) { len = mg_printf(conn, "%X\r\n%s\r\n", len, buf); } if (buf != mem && buf != NULL) { free(buf); } return len; } 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] == '%' && 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 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_var(const char *data, size_t data_len, 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 (data == NULL || name == NULL || data_len == 0) { len = -1; dst[0] = '\0'; } else { name_len = strlen(name); e = data + data_len; len = -1; dst[0] = '\0'; // data is "var1=val1&var2=val2...". Find variable first for (p = data; p + name_len < e; p++) { if ((p == data || p[-1] == '&') && p[name_len] == '=' && !mg_strncasecmp(name, p, name_len)) { // Point p to variable value p += name_len + 1; // Point s to the end of the value s = (const char *) memchr(p, '&', (size_t)(e - p)); if (s == NULL) { s = e; } assert(s >= p); // Decode variable into destination buffer len = mg_url_decode(p, (size_t)(s - p), dst, dst_len, 1); // Redirect error code from -1 to -2 (destination buffer too small). if (len == -1) { len = -2; } break; } } } return len; } int mg_get_cookie(const char *cookie_header, const char *var_name, char *dst, size_t dst_size) { const char *s, *p, *end; int name_len, len = -1; if (dst == NULL || dst_size == 0) { len = -2; } else if (var_name == NULL || (s = cookie_header) == NULL) { len = -1; dst[0] = '\0'; } else { name_len = (int) strlen(var_name); end = s + strlen(s); dst[0] = '\0'; for (; (s = mg_strcasestr(s, var_name)) != NULL; s += name_len) { if (s[name_len] == '=') { s += name_len + 1; if ((p = strchr(s, ' ')) == NULL) p = end; if (p[-1] == ';') p--; if (*s == '"' && p[-1] == '"' && p > s + 1) { s++; p--; } if ((size_t) (p - s) < dst_size) { len = p - s; mg_strlcpy(dst, s, (size_t) len + 1); } else { len = -3; } break; } } } return len; } static void convert_uri_to_file_name(struct mg_connection *conn, char *buf, size_t buf_len, struct file *filep) { struct vec a, b; const char *rewrite, *uri = conn->request_info.uri, *root = conn->ctx->config[DOCUMENT_ROOT]; char *p; int match_len; char gz_path[PATH_MAX]; char const* accept_encoding; // Using buf_len - 1 because memmove() for PATH_INFO may shift part // of the path one byte on the right. // If document_root is NULL, leave the file empty. mg_snprintf(conn, buf, buf_len - 1, "%s%s", root == NULL ? "" : root, root == NULL ? "" : uri); rewrite = conn->ctx->config[REWRITE]; while ((rewrite = next_option(rewrite, &a, &b)) != NULL) { if ((match_len = match_prefix(a.ptr, a.len, uri)) > 0) { mg_snprintf(conn, buf, buf_len - 1, "%.*s%s", (int) b.len, b.ptr, uri + match_len); break; } } if (mg_stat(conn, buf, filep)) return; // if we can't find the actual file, look for the file // with the same name but a .gz extension. If we find it, // use that and set the gzipped flag in the file struct // to indicate that the response need to have the content- // encoding: gzip header // we can only do this if the browser declares support if ((accept_encoding = mg_get_header(conn, "Accept-Encoding")) != NULL) { if (strstr(accept_encoding,"gzip") != NULL) { snprintf(gz_path, sizeof(gz_path), "%s.gz", buf); if (mg_stat(conn, gz_path, filep)) { filep->gzipped = 1; return; } } } // Support PATH_INFO for CGI scripts. for (p = buf + strlen(root == NULL ? "" : root); *p != '\0'; p++) { if (*p == '/') { *p = '\0'; if (match_prefix(conn->ctx->config[CGI_EXTENSIONS], strlen(conn->ctx->config[CGI_EXTENSIONS]), buf) > 0 && mg_stat(conn, buf, filep)) { // Shift PATH_INFO block one character right, e.g. // "/x.cgi/foo/bar\x00" => "/x.cgi\x00/foo/bar\x00" // conn->path_info is pointing to the local variable "path" declared // in handle_request(), so PATH_INFO is not valid after // handle_request returns. conn->path_info = p + 1; memmove(p + 2, p + 1, strlen(p + 1) + 1); // +1 is for trailing \0 p[1] = '/'; break; } else { *p = '/'; } } } } // 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 get_request_len(const char *buf, int buflen) { const char *s, *e; int len = 0; for (s = buf, e = s + buflen - 1; len <= 0 && s < e; s++) // Control characters are not allowed but >=128 is. if (!isprint(* (const unsigned char *) s) && *s != '\r' && *s != '\n' && * (const unsigned char *) s < 128) { len = -1; break; // [i_a] abort scan as soon as one malformed character is found; // don't let subsequent \r\n\r\n win us over anyhow } else if (s[0] == '\n' && s[1] == '\n') { len = (int) (s - buf) + 2; } else if (s[0] == '\n' && &s[1] < e && s[1] == '\r' && s[2] == '\n') { len = (int) (s - buf) + 3; } return len; } // Convert month to the month number. Return -1 on error, or month number static int get_month_index(const char *s) { 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 num_leap_years(int year) { return year / 4 - year / 100 + year / 400; } // Parse UTC date-time string, and return the corresponding time_t value. static time_t 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 = get_month_index(month_str)) != -1) { leap_days = num_leap_years(year) - 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; } // Protect against directory disclosure attack by removing '..', // excessive '/' and '\' characters static void remove_double_dots_and_double_slashes(char *s) { char *p = s; while (*s != '\0') { *p++ = *s++; if (s[-1] == '/' || s[-1] == '\\') { // Skip all following slashes, backslashes and double-dots while (s[0] != '\0') { if (s[0] == '/' || s[0] == '\\') { s++; } else if (s[0] == '.' && s[1] == '.') { s += 2; } else { break; } } } } *p = '\0'; } static const struct { const char *extension; size_t ext_len; const char *mime_type; } builtin_mime_types[] = { {".html", 5, "text/html"}, {".htm", 4, "text/html"}, {".shtm", 5, "text/html"}, {".shtml", 6, "text/html"}, {".css", 4, "text/css"}, {".js", 3, "application/x-javascript"}, {".ico", 4, "image/x-icon"}, {".gif", 4, "image/gif"}, {".jpg", 4, "image/jpeg"}, {".jpeg", 5, "image/jpeg"}, {".png", 4, "image/png"}, {".svg", 4, "image/svg+xml"}, {".txt", 4, "text/plain"}, {".torrent", 8, "application/x-bittorrent"}, {".wav", 4, "audio/x-wav"}, {".mp3", 4, "audio/x-mp3"}, {".mid", 4, "audio/mid"}, {".m3u", 4, "audio/x-mpegurl"}, {".ogg", 4, "application/ogg"}, {".ram", 4, "audio/x-pn-realaudio"}, {".xml", 4, "text/xml"}, {".json", 5, "text/json"}, {".xslt", 5, "application/xml"}, {".xsl", 4, "application/xml"}, {".ra", 3, "audio/x-pn-realaudio"}, {".doc", 4, "application/msword"}, {".exe", 4, "application/octet-stream"}, {".zip", 4, "application/x-zip-compressed"}, {".xls", 4, "application/excel"}, {".tgz", 4, "application/x-tar-gz"}, {".tar", 4, "application/x-tar"}, {".gz", 3, "application/x-gunzip"}, {".arj", 4, "application/x-arj-compressed"}, {".rar", 4, "application/x-arj-compressed"}, {".rtf", 4, "application/rtf"}, {".pdf", 4, "application/pdf"}, {".swf", 4, "application/x-shockwave-flash"}, {".mpg", 4, "video/mpeg"}, {".webm", 5, "video/webm"}, {".mpeg", 5, "video/mpeg"}, {".mov", 4, "video/quicktime"}, {".mp4", 4, "video/mp4"}, {".m4v", 4, "video/x-m4v"}, {".asf", 4, "video/x-ms-asf"}, {".avi", 4, "video/x-msvideo"}, {".bmp", 4, "image/bmp"}, {".ttf", 4, "application/x-font-ttf"}, {NULL, 0, NULL} }; const char *mg_get_builtin_mime_type(const char *path) { const char *ext; size_t i, path_len; path_len = strlen(path); for (i = 0; builtin_mime_types[i].extension != NULL; i++) { ext = path + (path_len - builtin_mime_types[i].ext_len); if (path_len > builtin_mime_types[i].ext_len && mg_strcasecmp(ext, builtin_mime_types[i].extension) == 0) { return builtin_mime_types[i].mime_type; } } return "text/plain"; } // Look at the "path" extension and figure what mime type it has. // Store mime type in the vector. static void get_mime_type(struct mg_context *ctx, const char *path, struct vec *vec) { struct vec ext_vec, mime_vec; const char *list, *ext; size_t path_len; path_len = strlen(path); // Scan user-defined mime types first, in case user wants to // override default mime types. list = ctx->config[EXTRA_MIME_TYPES]; while ((list = next_option(list, &ext_vec, &mime_vec)) != NULL) { // ext now points to the path suffix ext = path + path_len - ext_vec.len; if (mg_strncasecmp(ext, ext_vec.ptr, ext_vec.len) == 0) { *vec = mime_vec; return; } } vec->ptr = mg_get_builtin_mime_type(path); vec->len = strlen(vec->ptr); } static int is_big_endian(void) { static const int n = 1; return ((char *) &n)[0] == 0; } #ifndef HAVE_MD5 typedef struct MD5Context { uint32_t buf[4]; uint32_t bits[2]; unsigned char in[64]; } MD5_CTX; static void byteReverse(unsigned char *buf, unsigned longs) { uint32_t t; // Forrest: MD5 expect LITTLE_ENDIAN, swap if BIG_ENDIAN if (is_big_endian()) { do { t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 | ((unsigned) buf[1] << 8 | buf[0]); * (uint32_t *) buf = t; buf += 4; } while (--longs); } } #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<>(32-s), w += x ) // Start MD5 accumulation. Set bit count to 0 and buffer to mysterious // initialization constants. static void MD5Init(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]) { register 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; } static void MD5Update(MD5_CTX *ctx, unsigned char const *buf, unsigned len) { uint32_t t; t = ctx->bits[0]; if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t) ctx->bits[1]++; ctx->bits[1] += 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); } static void MD5Final(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 // !HAVE_MD5 // Stringify binary data. Output buffer must be twice as big as input, // because each byte takes 2 bytes in string representation static void bin2str(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'; } // Return stringified MD5 hash for list of strings. Buffer must be 33 bytes. char *mg_md5(char buf[33], ...) { unsigned char hash[16]; const char *p; va_list ap; MD5_CTX ctx; MD5Init(&ctx); va_start(ap, buf); while ((p = va_arg(ap, const char *)) != NULL) { MD5Update(&ctx, (const unsigned char *) p, (unsigned) strlen(p)); } va_end(ap); MD5Final(hash, &ctx); bin2str(buf, hash, sizeof(hash)); return buf; } // Check the user's password, return 1 if OK static int check_password(const char *method, const char *ha1, const char *uri, const char *nonce, const char *nc, const char *cnonce, const char *qop, const char *response) { char ha2[32 + 1], expected_response[32 + 1]; // Some of the parameters may be NULL if (method == NULL || nonce == NULL || nc == NULL || cnonce == NULL || qop == NULL || response == NULL) { return 0; } // NOTE(lsm): due to a bug in MSIE, we do not compare the URI // TODO(lsm): check for authentication timeout if (// strcmp(dig->uri, c->ouri) != 0 || strlen(response) != 32 // || now - strtoul(dig->nonce, NULL, 10) > 3600 ) { return 0; } mg_md5(ha2, method, ":", uri, NULL); mg_md5(expected_response, ha1, ":", nonce, ":", nc, ":", cnonce, ":", qop, ":", ha2, NULL); return mg_strcasecmp(response, expected_response) == 0; } // Use the global passwords file, if specified by auth_gpass option, // or search for .htpasswd in the requested directory. static void open_auth_file(struct mg_connection *conn, const char *path, struct file *filep) { char name[PATH_MAX]; const char *p, *e, *gpass = conn->ctx->config[GLOBAL_PASSWORDS_FILE]; struct file file = STRUCT_FILE_INITIALIZER; if (gpass != NULL) { // Use global passwords file if (!mg_fopen(conn, gpass, "r", filep)) { cry(conn, "fopen(%s): %s", gpass, strerror(ERRNO)); } // Important: using local struct file to test path for is_directory flag. // If filep is used, mg_stat() makes it appear as if auth file was opened. } else if (mg_stat(conn, path, &file) && file.is_directory) { mg_snprintf(conn, name, sizeof(name), "%s%c%s", path, '/', PASSWORDS_FILE_NAME); mg_fopen(conn, name, "r", filep); } else { // Try to find .htpasswd in requested directory. for (p = path, e = p + strlen(p) - 1; e > p; e--) if (e[0] == '/') break; mg_snprintf(conn, name, sizeof(name), "%.*s%c%s", (int) (e - p), p, '/', PASSWORDS_FILE_NAME); mg_fopen(conn, name, "r", filep); } } // Parsed Authorization header struct ah { char *user, *uri, *cnonce, *response, *qop, *nc, *nonce; }; // Return 1 on success. Always initializes the ah structure. static int parse_auth_header(struct mg_connection *conn, char *buf, size_t buf_size, struct ah *ah) { char *name, *value, *s; const char *auth_header; (void) memset(ah, 0, sizeof(*ah)); if ((auth_header = mg_get_header(conn, "Authorization")) == NULL || mg_strncasecmp(auth_header, "Digest ", 7) != 0) { return 0; } // Make modifiable copy of the auth header (void) mg_strlcpy(buf, auth_header + 7, buf_size); s = buf; // Parse authorization header for (;;) { // Gobble initial spaces while (isspace(* (unsigned char *) s)) { s++; } name = skip_quoted(&s, "=", " ", 0); // Value is either quote-delimited, or ends at first comma or space. if (s[0] == '\"') { s++; value = skip_quoted(&s, "\"", " ", '\\'); if (s[0] == ',') { s++; } } else { value = skip_quoted(&s, ", ", " ", 0); // IE uses commas, FF uses spaces } if (*name == '\0') { break; } if (!strcmp(name, "username")) { ah->user = value; } else if (!strcmp(name, "cnonce")) { ah->cnonce = value; } else if (!strcmp(name, "response")) { ah->response = value; } else if (!strcmp(name, "uri")) { ah->uri = value; } else if (!strcmp(name, "qop")) { ah->qop = value; } else if (!strcmp(name, "nc")) { ah->nc = value; } else if (!strcmp(name, "nonce")) { ah->nonce = value; } } // CGI needs it as REMOTE_USER if (ah->user != NULL) { conn->request_info.remote_user = mg_strdup(ah->user); } else { return 0; } return 1; } static char *mg_fgets(char *buf, size_t size, struct file *filep, char **p) { char *eof; size_t len; char *memend; if (filep->membuf != NULL && *p != NULL) { memend = (char *) &filep->membuf[filep->size]; // Search for \n from p till the end of stream eof = (char *) memchr(*p, '\n', memend - *p); if (eof != NULL) { eof += 1; // Include \n } else { eof = memend; // Copy remaining data } len = (size_t) (eof - *p) > size - 1 ? size - 1 : (size_t) (eof - *p); memcpy(buf, *p, len); buf[len] = '\0'; *p += len; return len ? eof : NULL; } else if (filep->fp != NULL) { return fgets(buf, size, filep->fp); } else { return NULL; } } // Authorize against the opened passwords file. Return 1 if authorized. static int authorize(struct mg_connection *conn, struct file *filep) { struct ah ah; char line[256], f_user[256], ha1[256], f_domain[256], buf[MG_BUF_LEN], *p; if (!parse_auth_header(conn, buf, sizeof(buf), &ah)) { return 0; } // Loop over passwords file p = (char *) filep->membuf; while (mg_fgets(line, sizeof(line), filep, &p) != NULL) { if (sscanf(line, "%[^:]:%[^:]:%s", f_user, f_domain, ha1) != 3) { continue; } if (!strcmp(ah.user, f_user) && !strcmp(conn->ctx->config[AUTHENTICATION_DOMAIN], f_domain)) return check_password(conn->request_info.request_method, ha1, ah.uri, ah.nonce, ah.nc, ah.cnonce, ah.qop, ah.response); } return 0; } // Return 1 if request is authorised, 0 otherwise. static int check_authorization(struct mg_connection *conn, const char *path) { char fname[PATH_MAX]; struct vec uri_vec, filename_vec; const char *list; struct file file = STRUCT_FILE_INITIALIZER; int authorized = 1; list = conn->ctx->config[PROTECT_URI]; while ((list = next_option(list, &uri_vec, &filename_vec)) != NULL) { if (!memcmp(conn->request_info.uri, uri_vec.ptr, uri_vec.len)) { mg_snprintf(conn, fname, sizeof(fname), "%.*s", (int) filename_vec.len, filename_vec.ptr); if (!mg_fopen(conn, fname, "r", &file)) { cry(conn, "%s: cannot open %s: %s", __func__, fname, strerror(errno)); } break; } } if (!is_file_opened(&file)) { open_auth_file(conn, path, &file); } if (is_file_opened(&file)) { authorized = authorize(conn, &file); mg_fclose(&file); } return authorized; } static void send_authorization_request(struct mg_connection *conn) { conn->status_code = 401; mg_printf(conn, "HTTP/1.1 401 Unauthorized\r\n" "Content-Length: 0\r\n" "WWW-Authenticate: Digest qop=\"auth\", " "realm=\"%s\", nonce=\"%lu\"\r\n\r\n", conn->ctx->config[AUTHENTICATION_DOMAIN], (unsigned long) time(NULL)); } static int is_authorized_for_put(struct mg_connection *conn) { struct file file = STRUCT_FILE_INITIALIZER; const char *passfile = conn->ctx->config[PUT_DELETE_PASSWORDS_FILE]; int ret = 0; if (passfile != NULL && mg_fopen(conn, passfile, "r", &file)) { ret = authorize(conn, &file); mg_fclose(&file); } return ret; } int mg_modify_passwords_file(const char *fname, const char *domain, const char *user, const char *pass) { int found; char line[512], u[512], d[512], ha1[33], tmp[PATH_MAX]; FILE *fp, *fp2; found = 0; fp = fp2 = NULL; // Regard empty password as no password - remove user record. if (pass != NULL && pass[0] == '\0') { pass = NULL; } (void) snprintf(tmp, sizeof(tmp), "%s.tmp", fname); // Create the file if does not exist if ((fp = fopen(fname, "a+")) != NULL) { (void) fclose(fp); } // Open the given file and temporary file if ((fp = fopen(fname, "r")) == NULL) { return 0; } else if ((fp2 = fopen(tmp, "w+")) == NULL) { fclose(fp); return 0; } // Copy the stuff to temporary file while (fgets(line, sizeof(line), fp) != NULL) { if (sscanf(line, "%[^:]:%[^:]:%*s", u, d) != 2) { continue; } if (!strcmp(u, user) && !strcmp(d, domain)) { found++; if (pass != NULL) { mg_md5(ha1, user, ":", domain, ":", pass, NULL); fprintf(fp2, "%s:%s:%s\n", user, domain, ha1); } } else { fprintf(fp2, "%s", line); } } // If new user, just add it if (!found && pass != NULL) { mg_md5(ha1, user, ":", domain, ":", pass, NULL); fprintf(fp2, "%s:%s:%s\n", user, domain, ha1); } // Close files fclose(fp); fclose(fp2); // Put the temp file in place of real file remove(fname); rename(tmp, fname); return 1; } static SOCKET conn2(const char *host, int port, int use_ssl, char *ebuf, size_t ebuf_len) { struct sockaddr_in sin; struct hostent *he; SOCKET sock = INVALID_SOCKET; if (host == NULL) { snprintf(ebuf, ebuf_len, "%s", "NULL host"); } else if (use_ssl && SSLv23_client_method == NULL) { snprintf(ebuf, ebuf_len, "%s", "SSL is not initialized"); // TODO(lsm): use something threadsafe instead of gethostbyname() } else if ((he = gethostbyname(host)) == NULL) { snprintf(ebuf, ebuf_len, "gethostbyname(%s): %s", host, strerror(ERRNO)); } else if ((sock = socket(PF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) { snprintf(ebuf, ebuf_len, "socket(): %s", strerror(ERRNO)); } else { set_close_on_exec(sock); sin.sin_family = AF_INET; sin.sin_port = htons((uint16_t) port); sin.sin_addr = * (struct in_addr *) he->h_addr_list[0]; if (connect(sock, (struct sockaddr *) &sin, sizeof(sin)) != 0) { snprintf(ebuf, ebuf_len, "connect(%s:%d): %s", host, port, strerror(ERRNO)); closesocket(sock); sock = INVALID_SOCKET; } } return sock; } void mg_url_encode(const char *src, char *dst, size_t dst_len) { static const char *dont_escape = "._-$,;~()"; static const char *hex = "0123456789abcdef"; const char *end = dst + dst_len - 1; for (; *src != '\0' && dst < end; src++, dst++) { if (isalnum(*(const unsigned char *) src) || strchr(dont_escape, * (const unsigned char *) src) != NULL) { *dst = *src; } else if (dst + 2 < end) { dst[0] = '%'; dst[1] = hex[(* (const unsigned char *) src) >> 4]; dst[2] = hex[(* (const unsigned char *) src) & 0xf]; dst += 2; } } *dst = '\0'; } static void print_dir_entry(struct de *de) { char size[64], mod[64], href[PATH_MAX]; if (de->file.is_directory) { mg_snprintf(de->conn, size, sizeof(size), "%s", "[DIRECTORY]"); } else { // We use (signed) cast below because MSVC 6 compiler cannot // convert unsigned __int64 to double. Sigh. if (de->file.size < 1024) { mg_snprintf(de->conn, size, sizeof(size), "%d", (int) de->file.size); } else if (de->file.size < 0x100000) { mg_snprintf(de->conn, size, sizeof(size), "%.1fk", (double) de->file.size / 1024.0); } else if (de->file.size < 0x40000000) { mg_snprintf(de->conn, size, sizeof(size), "%.1fM", (double) de->file.size / 1048576); } else { mg_snprintf(de->conn, size, sizeof(size), "%.1fG", (double) de->file.size / 1073741824); } } strftime(mod, sizeof(mod), "%d-%b-%Y %H:%M", localtime(&de->file.modification_time)); mg_url_encode(de->file_name, href, sizeof(href)); de->conn->num_bytes_sent += mg_chunked_printf(de->conn, "%s%s" " %s  %s\n", de->conn->request_info.uri, href, de->file.is_directory ? "/" : "", de->file_name, de->file.is_directory ? "/" : "", mod, size); } // This function is called from send_directory() and used for // sorting directory entries by size, or name, or modification time. // On windows, __cdecl specification is needed in case if project is built // with __stdcall convention. qsort always requires __cdels callback. static int WINCDECL compare_dir_entries(const void *p1, const void *p2) { const struct de *a = (const struct de *) p1, *b = (const struct de *) p2; const char *query_string = a->conn->request_info.query_string; int cmp_result = 0; if (query_string == NULL) { query_string = "na"; } if (a->file.is_directory && !b->file.is_directory) { return -1; // Always put directories on top } else if (!a->file.is_directory && b->file.is_directory) { return 1; // Always put directories on top } else if (*query_string == 'n') { cmp_result = strcmp(a->file_name, b->file_name); } else if (*query_string == 's') { cmp_result = a->file.size == b->file.size ? 0 : a->file.size > b->file.size ? 1 : -1; } else if (*query_string == 'd') { cmp_result = a->file.modification_time == b->file.modification_time ? 0 : a->file.modification_time > b->file.modification_time ? 1 : -1; } return query_string[1] == 'd' ? -cmp_result : cmp_result; } static int must_hide_file(struct mg_connection *conn, const char *path) { const char *pw_pattern = "**" PASSWORDS_FILE_NAME "$"; const char *pattern = conn->ctx->config[HIDE_FILES]; return match_prefix(pw_pattern, strlen(pw_pattern), path) > 0 || (pattern != NULL && match_prefix(pattern, strlen(pattern), path) > 0); } static int scan_directory(struct mg_connection *conn, const char *dir, void *data, void (*cb)(struct de *, void *)) { char path[PATH_MAX]; struct dirent *dp; DIR *dirp; struct de de; if ((dirp = opendir(dir)) == NULL) { return 0; } else { de.conn = conn; while ((dp = readdir(dirp)) != NULL) { // Do not show current dir and hidden files if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, "..") || must_hide_file(conn, dp->d_name)) { continue; } mg_snprintf(conn, path, sizeof(path), "%s%c%s", dir, '/', dp->d_name); // If we don't memset stat structure to zero, mtime will have // garbage and strftime() will segfault later on in // print_dir_entry(). memset is required only if mg_stat() // fails. For more details, see // http://code.google.com/p/mongoose/issues/detail?id=79 memset(&de.file, 0, sizeof(de.file)); mg_stat(conn, path, &de.file); de.file_name = dp->d_name; cb(&de, data); } (void) closedir(dirp); } return 1; } static int remove_directory(struct mg_connection *conn, const char *dir) { char path[PATH_MAX]; struct dirent *dp; DIR *dirp; struct de de; if ((dirp = opendir(dir)) == NULL) { return 0; } else { de.conn = conn; while ((dp = readdir(dirp)) != NULL) { // Do not show current dir, but show hidden files if (!strcmp(dp->d_name, ".") || !strcmp(dp->d_name, "..")) { continue; } mg_snprintf(conn, path, sizeof(path), "%s%c%s", dir, '/', dp->d_name); // If we don't memset stat structure to zero, mtime will have // garbage and strftime() will segfault later on in // print_dir_entry(). memset is required only if mg_stat() // fails. For more details, see // http://code.google.com/p/mongoose/issues/detail?id=79 memset(&de.file, 0, sizeof(de.file)); mg_stat(conn, path, &de.file); if(de.file.modification_time) { if(de.file.is_directory) { remove_directory(conn, path); } else { mg_remove(path); } } } (void) closedir(dirp); rmdir(dir); } return 1; } struct dir_scan_data { struct de *entries; int num_entries; int arr_size; }; // Behaves like realloc(), but frees original pointer on failure static void *realloc2(void *ptr, size_t size) { void *new_ptr = realloc(ptr, size); if (new_ptr == NULL) { free(ptr); } return new_ptr; } static void dir_scan_callback(struct de *de, void *data) { struct dir_scan_data *dsd = (struct dir_scan_data *) data; if (dsd->entries == NULL || dsd->num_entries >= dsd->arr_size) { dsd->arr_size *= 2; dsd->entries = (struct de *) realloc2(dsd->entries, dsd->arr_size * sizeof(dsd->entries[0])); } if (dsd->entries == NULL) { // TODO(lsm): propagate an error to the caller dsd->num_entries = 0; } else { dsd->entries[dsd->num_entries].file_name = mg_strdup(de->file_name); dsd->entries[dsd->num_entries].file = de->file; dsd->entries[dsd->num_entries].conn = de->conn; dsd->num_entries++; } } static void handle_directory_request(struct mg_connection *conn, const char *dir) { int i, sort_direction; struct dir_scan_data data = { NULL, 0, 128 }; if (!scan_directory(conn, dir, &data, dir_scan_callback)) { send_http_error(conn, 500, "Cannot open directory", "Error: opendir(%s): %s", dir, strerror(ERRNO)); return; } sort_direction = conn->request_info.query_string != NULL && conn->request_info.query_string[1] == 'd' ? 'a' : 'd'; conn->must_close = 1; mg_printf(conn, "%s", "HTTP/1.1 200 OK\r\n" "Transfer-Encoding: Chunked\r\n" "Content-Type: text/html; charset=utf-8\r\n\r\n"); conn->num_bytes_sent += mg_chunked_printf(conn, "Index of %s" "" "

Index of %s

"
      ""
      ""
      ""
      "",
      conn->request_info.uri, conn->request_info.uri,
      sort_direction, sort_direction, sort_direction);

  // Print first entry - link to a parent directory
  conn->num_bytes_sent += mg_chunked_printf(conn,
      ""
      "\n",
      conn->request_info.uri, "..", "Parent directory", "-", "-");

  // Sort and print directory entries
  qsort(data.entries, (size_t) data.num_entries, sizeof(data.entries[0]),
        compare_dir_entries);
  for (i = 0; i < data.num_entries; i++) {
    print_dir_entry(&data.entries[i]);
    free(data.entries[i].file_name);
  }
  free(data.entries);

  conn->num_bytes_sent += mg_chunked_printf(conn, "%s", "
NameModifiedSize
%s %s  %s
");
  conn->num_bytes_sent += mg_write(conn, "0\r\n\r\n", 5);
  conn->status_code = 200;
}

// Send len bytes from the opened file to the client.
static void send_file_data(struct mg_connection *conn, struct file *filep,
                           int64_t offset, int64_t len) {
  char buf[MG_BUF_LEN];
  int to_read, num_read, num_written;

  // Sanity check the offset
  offset = offset < 0 ? 0 : offset > filep->size ? filep->size : offset;

  if (len > 0 && filep->membuf != NULL && filep->size > 0) {
    if (len > filep->size - offset) {
      len = filep->size - offset;
    }
    mg_write(conn, filep->membuf + offset, (size_t) len);
  } else if (len > 0 && filep->fp != NULL) {
    fseeko(filep->fp, offset, SEEK_SET);
    while (len > 0) {
      // Calculate how much to read from the file in the buffer
      to_read = sizeof(buf);
      if ((int64_t) to_read > len) {
        to_read = (int) len;
      }

      // Read from file, exit the loop on error
      if ((num_read = fread(buf, 1, (size_t) to_read, filep->fp)) <= 0) {
        break;
      }

      // Send read bytes to the client, exit the loop on error
      if ((num_written = mg_write(conn, buf, (size_t) num_read)) != num_read) {
        break;
      }

      // Both read and were successful, adjust counters
      conn->num_bytes_sent += num_written;
      len -= num_written;
    }
  }
}

static int parse_range_header(const char *header, int64_t *a, int64_t *b) {
  return sscanf(header, "bytes=%" INT64_FMT "-%" INT64_FMT, a, b);
}

static void 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 void construct_etag(char *buf, size_t buf_len,
                           const struct file *filep) {
  snprintf(buf, buf_len, "\"%lx.%" INT64_FMT "\"",
           (unsigned long) filep->modification_time, filep->size);
}

static void fclose_on_exec(struct file *filep) {
  if (filep != NULL && filep->fp != NULL) {
#ifndef _WIN32
    fcntl(fileno(filep->fp), F_SETFD, FD_CLOEXEC);
#endif
  }
}

static void handle_file_request(struct mg_connection *conn, const char *path,
                                struct file *filep) {
  char date[64], lm[64], etag[64], range[64];
  const char *msg = "OK", *hdr;
  time_t curtime = time(NULL);
  int64_t cl, r1, r2;
  struct vec mime_vec;
  int n;
  char gz_path[PATH_MAX];
  char const* encoding = "";

  get_mime_type(conn->ctx, path, &mime_vec);
  cl = filep->size;
  conn->status_code = 200;
  range[0] = '\0';

  // if this file is in fact a pre-gzipped file, rewrite its filename
  // it's important to rewrite the filename after resolving
  // the mime type from it, to preserve the actual file's type
  if (filep->gzipped) {
    snprintf(gz_path, sizeof(gz_path), "%s.gz", path);
    path = gz_path;
    encoding = "Content-Encoding: gzip\r\n";
  }

  if (!mg_fopen(conn, path, "rb", filep)) {
    send_http_error(conn, 500, http_500_error,
                    "fopen(%s): %s", path, strerror(ERRNO));
    return;
  }

  fclose_on_exec(filep);

  // If Range: header specified, act accordingly
  r1 = r2 = 0;
  hdr = mg_get_header(conn, "Range");
  if (hdr != NULL && (n = parse_range_header(hdr, &r1, &r2)) > 0 &&
      r1 >= 0 && r2 >= 0) {
    // actually, range requests don't play well with a pre-gzipped
    // file (since the range is specified in the uncmpressed space)
    if (filep->gzipped) {
      send_http_error(conn, 501, "Not Implemented",
                      "range requests in gzipped files are not supported");
      return;
    }
    conn->status_code = 206;
    cl = n == 2 ? (r2 > cl ? cl : r2) - r1 + 1: cl - r1;
    mg_snprintf(conn, range, sizeof(range),
                "Content-Range: bytes "
                "%" INT64_FMT "-%"
                INT64_FMT "/%" INT64_FMT "\r\n",
                r1, r1 + cl - 1, filep->size);
    msg = "Partial Content";
  }

  // Prepare Etag, Date, Last-Modified headers. Must be in UTC, according to
  // http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.3
  gmt_time_string(date, sizeof(date), &curtime);
  gmt_time_string(lm, sizeof(lm), &filep->modification_time);
  construct_etag(etag, sizeof(etag), filep);

  (void) mg_printf(conn,
      "HTTP/1.1 %d %s\r\n"
      "Date: %s\r\n"
      "Last-Modified: %s\r\n"
      "Etag: %s\r\n"
      "Content-Type: %.*s\r\n"
      "Content-Length: %" INT64_FMT "\r\n"
      "Connection: %s\r\n"
      "Accept-Ranges: bytes\r\n"
      "%s%s%s\r\n",
      conn->status_code, msg, date, lm, etag, (int) mime_vec.len,
      mime_vec.ptr, cl, suggest_connection_header(conn), range, encoding,
      EXTRA_HTTP_HEADERS);

  if (strcmp(conn->request_info.request_method, "HEAD") != 0) {
    send_file_data(conn, filep, r1, cl);
  }
  mg_fclose(filep);
}

void mg_send_file(struct mg_connection *conn, const char *path) {
  struct file file = STRUCT_FILE_INITIALIZER;
  if (mg_stat(conn, path, &file)) {
    handle_file_request(conn, path, &file);
  } else {
    send_http_error(conn, 404, "Not Found", "%s", "File not found");
  }
}


// Parse HTTP headers from the given buffer, advance buffer to the point
// where parsing stopped.
static void parse_http_headers(char **buf, struct mg_request_info *ri) {
  int i;

  for (i = 0; i < (int) ARRAY_SIZE(ri->http_headers); i++) {
    ri->http_headers[i].name = skip_quoted(buf, ":", " ", 0);
    ri->http_headers[i].value = skip(buf, "\r\n");
    if (ri->http_headers[i].name[0] == '\0')
      break;
    ri->num_headers = i + 1;
  }
}

static int is_valid_http_method(const char *method) {
  return !strcmp(method, "GET") || !strcmp(method, "POST") ||
    !strcmp(method, "HEAD") || !strcmp(method, "CONNECT") ||
    !strcmp(method, "PUT") || !strcmp(method, "DELETE") ||
    !strcmp(method, "OPTIONS") || !strcmp(method, "PROPFIND")
    || !strcmp(method, "MKCOL")
          ;
}

// Parse HTTP request, fill in mg_request_info structure.
// This function modifies the buffer by NUL-terminating
// HTTP request components, header names and header values.
static int parse_http_message(char *buf, int len, struct mg_request_info *ri) {
  int is_request, request_length = get_request_len(buf, len);
  if (request_length > 0) {
    // Reset attributes. DO NOT TOUCH is_ssl, remote_ip, remote_port
    ri->remote_user = ri->request_method = ri->uri = ri->http_version = NULL;
    ri->num_headers = 0;

    buf[request_length - 1] = '\0';

    // RFC says that all initial whitespaces should be ingored
    while (*buf != '\0' && isspace(* (unsigned char *) buf)) {
      buf++;
    }
    ri->request_method = skip(&buf, " ");
    ri->uri = skip(&buf, " ");
    ri->http_version = skip(&buf, "\r\n");

    // HTTP message could be either HTTP request or HTTP response, e.g.
    // "GET / HTTP/1.0 ...." or  "HTTP/1.0 200 OK ..."
    is_request = is_valid_http_method(ri->request_method);
    if ((is_request && memcmp(ri->http_version, "HTTP/", 5) != 0) ||
        (!is_request && memcmp(ri->request_method, "HTTP/", 5) != 0)) {
      request_length = -1;
    } else {
      if (is_request) {
        ri->http_version += 5;
      }
      parse_http_headers(&buf, ri);
    }
  }
  return request_length;
}

// Keep reading the input (either opened file descriptor fd, or socket sock,
// or SSL descriptor ssl) into buffer buf, until \r\n\r\n appears in the
// buffer (which marks the end of HTTP request). Buffer buf may already
// have some data. The length of the data is stored in nread.
// Upon every read operation, increase nread by the number of bytes read.
static int read_request(FILE *fp, struct mg_connection *conn,
                        char *buf, int bufsiz, int *nread) {
  int request_len, n = 0;

  request_len = get_request_len(buf, *nread);
  while (conn->ctx->stop_flag == 0 &&
         *nread < bufsiz && request_len == 0 &&
         (n = pull(fp, conn, buf + *nread, bufsiz - *nread)) > 0) {
    *nread += n;
    assert(*nread <= bufsiz);
    request_len = get_request_len(buf, *nread);
  }

  return request_len <= 0 && n <= 0 ? -1 : request_len;
}

// For given directory path, substitute it to valid index file.
// Return 0 if index file has been found, -1 if not found.
// If the file is found, it's stats is returned in stp.
static int substitute_index_file(struct mg_connection *conn, char *path,
                                 size_t path_len, struct file *filep) {
  const char *list = conn->ctx->config[INDEX_FILES];
  struct file file = STRUCT_FILE_INITIALIZER;
  struct vec filename_vec;
  size_t n = strlen(path);
  int found = 0;

  // The 'path' given to us points to the directory. Remove all trailing
  // directory separator characters from the end of the path, and
  // then append single directory separator character.
  while (n > 0 && path[n - 1] == '/') {
    n--;
  }
  path[n] = '/';

  // 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 = next_option(list, &filename_vec, NULL)) != NULL) {

    // Ignore too long entries that may overflow path buffer
    if (filename_vec.len > path_len - (n + 2))
      continue;

    // Prepare full path to the index file
    mg_strlcpy(path + n + 1, filename_vec.ptr, filename_vec.len + 1);

    // Does it exist?
    if (mg_stat(conn, path, &file)) {
      // Yes it does, break the loop
      *filep = file;
      found = 1;
      break;
    }
  }

  // If no index file exists, restore directory path
  if (!found) {
    path[n] = '\0';
  }

  return found;
}

// Return True if we should reply 304 Not Modified.
static int is_not_modified(const struct mg_connection *conn,
                           const struct file *filep) {
  char etag[64];
  const char *ims = mg_get_header(conn, "If-Modified-Since");
  const char *inm = mg_get_header(conn, "If-None-Match");
  construct_etag(etag, sizeof(etag), filep);
  return (inm != NULL && !mg_strcasecmp(etag, inm)) ||
    (ims != NULL && filep->modification_time <= parse_date_string(ims));
}

static int forward_body_data(struct mg_connection *conn, FILE *fp,
                             SOCKET sock, SSL *ssl) {
  const char *expect, *body;
  char buf[MG_BUF_LEN];
  int to_read, nread, buffered_len, success = 0;

  expect = mg_get_header(conn, "Expect");
  assert(fp != NULL);

  if (conn->content_len == -1) {
    send_http_error(conn, 411, "Length Required", "%s", "");
  } else if (expect != NULL && mg_strcasecmp(expect, "100-continue")) {
    send_http_error(conn, 417, "Expectation Failed", "%s", "");
  } else {
    if (expect != NULL) {
      (void) mg_printf(conn, "%s", "HTTP/1.1 100 Continue\r\n\r\n");
    }

    body = conn->buf + conn->request_len + conn->consumed_content;
    buffered_len = &conn->buf[conn->data_len] - body;
    assert(buffered_len >= 0);
    assert(conn->consumed_content == 0);

    if (buffered_len > 0) {
      if ((int64_t) buffered_len > conn->content_len) {
        buffered_len = (int) conn->content_len;
      }
      push(fp, sock, ssl, body, (int64_t) buffered_len);
      conn->consumed_content += buffered_len;
    }

    nread = 0;
    while (conn->consumed_content < conn->content_len) {
      to_read = sizeof(buf);
      if ((int64_t) to_read > conn->content_len - conn->consumed_content) {
        to_read = (int) (conn->content_len - conn->consumed_content);
      }
      nread = pull(NULL, conn, buf, to_read);
      if (nread <= 0 || push(fp, sock, ssl, buf, nread) != nread) {
        break;
      }
      conn->consumed_content += nread;
    }

    if (conn->consumed_content == conn->content_len) {
      success = nread >= 0;
    }

    // Each error code path in this function must send an error
    if (!success) {
      send_http_error(conn, 577, http_500_error, "%s", "");
    }
  }

  return success;
}

#if !defined(NO_CGI)
// 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 cgi_env_block {
  struct mg_connection *conn;
  char buf[CGI_ENVIRONMENT_SIZE]; // Environment buffer
  int len; // Space taken
  char *vars[MAX_CGI_ENVIR_VARS]; // char **envp
  int nvars; // Number of variables
};

static char *addenv(struct cgi_env_block *block,
                    PRINTF_FORMAT_STRING(const char *fmt), ...)
  PRINTF_ARGS(2, 3);

// Append VARIABLE=VALUE\0 string to the buffer, and add a respective
// pointer into the vars array.
static char *addenv(struct cgi_env_block *block, const char *fmt, ...) {
  int n, space;
  char *added;
  va_list ap;

  // Calculate how much space is left in the buffer
  space = sizeof(block->buf) - block->len - 2;
  assert(space >= 0);

  // Make a pointer to the free space int the buffer
  added = block->buf + block->len;

  // Copy VARIABLE=VALUE\0 string into the free space
  va_start(ap, fmt);
  n = mg_vsnprintf(block->conn, 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;
  } else {
    cry(block->conn, "%s: CGI env buffer truncated for [%s]", __func__, fmt);
  }

  return added;
}

static void prepare_cgi_environment(struct mg_connection *conn,
                                    const char *prog,
                                    struct cgi_env_block *blk) {
  const struct mg_request_info *ri = &conn->request_info;
  const char *s, *slash;
  struct vec var_vec;
  char *p, src_addr[IP_ADDR_STR_LEN];
  int  i;

  blk->len = blk->nvars = 0;
  blk->conn = conn;
  sockaddr_to_string(src_addr, sizeof(src_addr), &conn->client.rsa);

  addenv(blk, "SERVER_NAME=%s", conn->ctx->config[AUTHENTICATION_DOMAIN]);
  addenv(blk, "SERVER_ROOT=%s", conn->ctx->config[DOCUMENT_ROOT]);
  addenv(blk, "DOCUMENT_ROOT=%s", conn->ctx->config[DOCUMENT_ROOT]);
  addenv(blk, "SERVER_SOFTWARE=%s/%s", "Mongoose", mg_version());

  // Prepare the environment block
  addenv(blk, "%s", "GATEWAY_INTERFACE=CGI/1.1");
  addenv(blk, "%s", "SERVER_PROTOCOL=HTTP/1.1");
  addenv(blk, "%s", "REDIRECT_STATUS=200"); // For PHP

  // TODO(lsm): fix this for IPv6 case
  addenv(blk, "SERVER_PORT=%d", ntohs(conn->client.lsa.sin.sin_port));

  addenv(blk, "REQUEST_METHOD=%s", ri->request_method);
  addenv(blk, "REMOTE_ADDR=%s", src_addr);
  addenv(blk, "REMOTE_PORT=%d", ri->remote_port);
  addenv(blk, "REQUEST_URI=%s%s%s", ri->uri,
         ri->query_string == NULL ? "" : "?",
         ri->query_string == NULL ? "" : ri->query_string);

  // SCRIPT_NAME
  if (conn->path_info != NULL) {
    addenv(blk, "SCRIPT_NAME=%.*s",
           (int) (strlen(ri->uri) - strlen(conn->path_info)), ri->uri);
    addenv(blk, "PATH_INFO=%s", conn->path_info);
  } else {
    s = strrchr(prog, '/');
    slash = strrchr(ri->uri, '/');
    addenv(blk, "SCRIPT_NAME=%.*s%s",
           slash == NULL ? 0 : (int) (slash - ri->uri), ri->uri,
           s == NULL ? prog : s);
  }

  addenv(blk, "SCRIPT_FILENAME=%s", prog);
  addenv(blk, "PATH_TRANSLATED=%s", prog);
  addenv(blk, "HTTPS=%s", conn->ssl == NULL ? "off" : "on");

  if ((s = mg_get_header(conn, "Content-Type")) != NULL)
    addenv(blk, "CONTENT_TYPE=%s", s);

  if (ri->query_string != NULL) {
    addenv(blk, "QUERY_STRING=%s", ri->query_string);
  }

  if ((s = mg_get_header(conn, "Content-Length")) != NULL)
    addenv(blk, "CONTENT_LENGTH=%s", s);

  if ((s = getenv("PATH")) != NULL)
    addenv(blk, "PATH=%s", s);

#if defined(_WIN32)
  if ((s = getenv("COMSPEC")) != NULL) {
    addenv(blk, "COMSPEC=%s", s);
  }
  if ((s = getenv("SYSTEMROOT")) != NULL) {
    addenv(blk, "SYSTEMROOT=%s", s);
  }
  if ((s = getenv("SystemDrive")) != NULL) {
    addenv(blk, "SystemDrive=%s", s);
  }
  if ((s = getenv("ProgramFiles")) != NULL) {
    addenv(blk, "ProgramFiles=%s", s);
  }
  if ((s = getenv("ProgramFiles(x86)")) != NULL) {
    addenv(blk, "ProgramFiles(x86)=%s", s);
  }
#else
  if ((s = getenv("LD_LIBRARY_PATH")) != NULL)
    addenv(blk, "LD_LIBRARY_PATH=%s", s);
#endif // _WIN32

  if ((s = getenv("PERLLIB")) != NULL)
    addenv(blk, "PERLLIB=%s", s);

  if (ri->remote_user != NULL) {
    addenv(blk, "REMOTE_USER=%s", ri->remote_user);
    addenv(blk, "%s", "AUTH_TYPE=Digest");
  }

  // Add all headers as HTTP_* variables
  for (i = 0; i < ri->num_headers; i++) {
    p = addenv(blk, "HTTP_%s=%s",
        ri->http_headers[i].name, ri->http_headers[i].value);

    // Convert variable name into uppercase, and change - to _
    for (; *p != '=' && *p != '\0'; p++) {
      if (*p == '-')
        *p = '_';
      *p = (char) toupper(* (unsigned char *) p);
    }
  }

  // Add user-specified variables
  s = conn->ctx->config[CGI_ENVIRONMENT];
  while ((s = next_option(s, &var_vec, NULL)) != NULL) {
    addenv(blk, "%.*s", (int) var_vec.len, var_vec.ptr);
  }

  blk->vars[blk->nvars++] = NULL;
  blk->buf[blk->len++] = '\0';

  assert(blk->nvars < (int) ARRAY_SIZE(blk->vars));
  assert(blk->len > 0);
  assert(blk->len < (int) sizeof(blk->buf));
}

static void handle_cgi_request(struct mg_connection *conn, const char *prog) {
  int headers_len, data_len, i, fdin[2], fdout[2];
  const char *status, *status_text;
  char buf[16384], *pbuf, dir[PATH_MAX], *p;
  struct mg_request_info ri;
  struct cgi_env_block blk;
  FILE *in = NULL, *out = NULL;
  struct file fout = STRUCT_FILE_INITIALIZER;
  pid_t pid = (pid_t) -1;

  prepare_cgi_environment(conn, prog, &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'.
  (void) mg_snprintf(conn, dir, sizeof(dir), "%s", prog);
  if ((p = strrchr(dir, '/')) != NULL) {
    *p++ = '\0';
  } else {
    dir[0] = '.', dir[1] = '\0';
    p = (char *) prog;
  }

  if (pipe(fdin) != 0 || pipe(fdout) != 0) {
    send_http_error(conn, 500, http_500_error,
        "Cannot create CGI pipe: %s", strerror(ERRNO));
    goto done;
  }

  pid = spawn_process(conn, p, blk.buf, blk.vars, fdin[0], fdout[1], dir);
  if (pid == (pid_t) -1) {
    send_http_error(conn, 500, http_500_error,
        "Cannot spawn CGI process [%s]: %s", prog, strerror(ERRNO));
    goto done;
  }

  // Make sure child closes all pipe descriptors. It must dup them to 0,1
  set_close_on_exec(fdin[0]);
  set_close_on_exec(fdin[1]);
  set_close_on_exec(fdout[0]);
  set_close_on_exec(fdout[1]);

  // Parent closes only one side of the pipes.
  // If we don't mark them as closed, close() attempt before
  // return from this function throws an exception on Windows.
  // Windows does not like when closed descriptor is closed again.
  (void) close(fdin[0]);
  (void) close(fdout[1]);
  fdin[0] = fdout[1] = -1;


  if ((in = fdopen(fdin[1], "wb")) == NULL ||
      (out = fdopen(fdout[0], "rb")) == NULL) {
    send_http_error(conn, 500, http_500_error,
        "fopen: %s", strerror(ERRNO));
    goto done;
  }

  setbuf(in, NULL);
  setbuf(out, NULL);
  fout.fp = out;

  // Send POST data to the CGI process if needed
  if (!strcmp(conn->request_info.request_method, "POST") &&
      !forward_body_data(conn, in, INVALID_SOCKET, NULL)) {
    goto done;
  }

  // Close so child gets an EOF.
  fclose(in);
  in = NULL;
  fdin[1] = -1;

  // Now read CGI reply into a buffer. We need to set correct
  // status code, thus we need to see all HTTP headers first.
  // Do not send anything back to client, until we buffer in all
  // HTTP headers.
  data_len = 0;
  headers_len = read_request(out, conn, buf, sizeof(buf), &data_len);
  if (headers_len <= 0) {
    send_http_error(conn, 500, http_500_error,
                    "CGI program sent malformed or too big (>%u bytes) "
                    "HTTP headers: [%.*s]",
                    (unsigned) sizeof(buf), data_len, buf);
    goto done;
  }
  pbuf = buf;
  buf[headers_len - 1] = '\0';
  parse_http_headers(&pbuf, &ri);

  // Make up and send the status line
  status_text = "OK";
  if ((status = get_header(&ri, "Status")) != NULL) {
    conn->status_code = atoi(status);
    status_text = status;
    while (isdigit(* (unsigned char *) status_text) || *status_text == ' ') {
      status_text++;
    }
  } else if (get_header(&ri, "Location") != NULL) {
    conn->status_code = 302;
  } else {
    conn->status_code = 200;
  }
  if (get_header(&ri, "Connection") != NULL &&
      !mg_strcasecmp(get_header(&ri, "Connection"), "keep-alive")) {
    conn->must_close = 1;
  }
  (void) mg_printf(conn, "HTTP/1.1 %d %s\r\n", conn->status_code,
                   status_text);

  // Send headers
  for (i = 0; i < ri.num_headers; i++) {
    mg_printf(conn, "%s: %s\r\n",
              ri.http_headers[i].name, ri.http_headers[i].value);
  }
  mg_write(conn, "\r\n", 2);

  // Send chunk of data that may have been read after the headers
  conn->num_bytes_sent += mg_write(conn, buf + headers_len,
                                   (size_t)(data_len - headers_len));

  // Read the rest of CGI output and send to the client
  send_file_data(conn, &fout, 0, INT64_MAX);

done:
  if (pid != (pid_t) -1) {
    kill(pid, SIGKILL);
  }
  if (fdin[0] != -1) {
    close(fdin[0]);
  }
  if (fdout[1] != -1) {
    close(fdout[1]);
  }

  if (in != NULL) {
    fclose(in);
  } else if (fdin[1] != -1) {
    close(fdin[1]);
  }

  if (out != NULL) {
    fclose(out);
  } else if (fdout[0] != -1) {
    close(fdout[0]);
  }
}
#endif // !NO_CGI

// For a given PUT path, create all intermediate subdirectories
// for given path. Return 0 if the path itself is a directory,
// or -1 on error, 1 if OK.
static int put_dir(struct mg_connection *conn, const char *path) {
  char buf[PATH_MAX];
  const char *s, *p;
  struct file file = STRUCT_FILE_INITIALIZER;
  int len, res = 1;

  for (s = p = path + 2; (p = strchr(s, '/')) != NULL; s = ++p) {
    len = p - path;
    if (len >= (int) sizeof(buf)) {
      res = -1;
      break;
    }
    memcpy(buf, path, len);
    buf[len] = '\0';

    // Try to create intermediate directory
    DEBUG_TRACE(("mkdir(%s)", buf));
    if (!mg_stat(conn, buf, &file) && mg_mkdir(buf, 0755) != 0) {
      res = -1;
      break;
    }

    // Is path itself a directory?
    if (p[1] == '\0') {
      res = 0;
    }
  }

  return res;
}

static void mkcol(struct mg_connection *conn, const char *path) {
  int rc, body_len;
  struct de de;
  memset(&de.file, 0, sizeof(de.file));
  mg_stat(conn, path, &de.file);

  if(de.file.modification_time) {
      send_http_error(conn, 405, "Method Not Allowed",
                      "mkcol(%s): %s", path, strerror(ERRNO));
      return;
  }

  body_len = conn->data_len - conn->request_len;
  if(body_len > 0) {
      send_http_error(conn, 415, "Unsupported media type",
                      "mkcol(%s): %s", path, strerror(ERRNO));
      return;
  }

  rc = mg_mkdir(path, 0755);

  if (rc == 0) {
    conn->status_code = 201;
    mg_printf(conn, "HTTP/1.1 %d Created\r\n\r\n", conn->status_code);
  } else if (rc == -1) {
      if(errno == EEXIST)
        send_http_error(conn, 405, "Method Not Allowed",
                      "mkcol(%s): %s", path, strerror(ERRNO));
      else if(errno == EACCES)
          send_http_error(conn, 403, "Forbidden",
                        "mkcol(%s): %s", path, strerror(ERRNO));
      else if(errno == ENOENT)
          send_http_error(conn, 409, "Conflict",
                        "mkcol(%s): %s", path, strerror(ERRNO));
      else
          send_http_error(conn, 500, http_500_error,
                          "fopen(%s): %s", path, strerror(ERRNO));
  }
}

static void put_file(struct mg_connection *conn, const char *path) {
  struct file file = STRUCT_FILE_INITIALIZER;
  const char *range;
  int64_t r1, r2;
  int rc;

  conn->status_code = mg_stat(conn, path, &file) ? 200 : 201;

  if ((rc = put_dir(conn, path)) == 0) {
    mg_printf(conn, "HTTP/1.1 %d OK\r\n\r\n", conn->status_code);
  } else if (rc == -1) {
    send_http_error(conn, 500, http_500_error,
                    "put_dir(%s): %s", path, strerror(ERRNO));
  } else if (!mg_fopen(conn, path, "wb+", &file) || file.fp == NULL) {
    mg_fclose(&file);
    send_http_error(conn, 500, http_500_error,
                    "fopen(%s): %s", path, strerror(ERRNO));
  } else {
    fclose_on_exec(&file);
    range = mg_get_header(conn, "Content-Range");
    r1 = r2 = 0;
    if (range != NULL && parse_range_header(range, &r1, &r2) > 0) {
      conn->status_code = 206;
      fseeko(file.fp, r1, SEEK_SET);
    }
    if (!forward_body_data(conn, file.fp, INVALID_SOCKET, NULL)) {
      conn->status_code = 500;
    }
    mg_printf(conn, "HTTP/1.1 %d OK\r\nContent-Length: 0\r\n\r\n",
              conn->status_code);
    mg_fclose(&file);
  }
}

static void send_ssi_file(struct mg_connection *, const char *,
                          struct file *, int);

static void do_ssi_include(struct mg_connection *conn, const char *ssi,
                           char *tag, int include_level) {
  char file_name[MG_BUF_LEN], path[PATH_MAX], *p;
  struct file file = STRUCT_FILE_INITIALIZER;

  // 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
    (void) mg_snprintf(conn, path, sizeof(path), "%s%c%s",
        conn->ctx->config[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
    (void) mg_snprintf(conn, 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
    (void) mg_snprintf(conn, path, sizeof(path), "%s", ssi);
    if ((p = strrchr(path, '/')) != NULL) {
      p[1] = '\0';
    }
    (void) mg_snprintf(conn, path + strlen(path),
        sizeof(path) - strlen(path), "%s", file_name);
  } else {
    cry(conn, "Bad SSI #include: [%s]", tag);
    return;
  }

  if (!mg_fopen(conn, path, "rb", &file)) {
    cry(conn, "Cannot open SSI #include: [%s]: fopen(%s): %s",
        tag, path, strerror(ERRNO));
  } else {
    fclose_on_exec(&file);
    if (match_prefix(conn->ctx->config[SSI_EXTENSIONS],
                     strlen(conn->ctx->config[SSI_EXTENSIONS]), path) > 0) {
      send_ssi_file(conn, path, &file, include_level + 1);
    } else {
      send_file_data(conn, &file, 0, INT64_MAX);
    }
    mg_fclose(&file);
  }
}

#if !defined(NO_POPEN)
static void do_ssi_exec(struct mg_connection *conn, char *tag) {
  char cmd[MG_BUF_LEN];
  struct file file = STRUCT_FILE_INITIALIZER;

  if (sscanf(tag, " \"%[^\"]\"", cmd) != 1) {
    cry(conn, "Bad SSI #exec: [%s]", tag);
  } else if ((file.fp = popen(cmd, "r")) == NULL) {
    cry(conn, "Cannot SSI #exec: [%s]: %s", cmd, strerror(ERRNO));
  } else {
    send_file_data(conn, &file, 0, INT64_MAX);
    pclose(file.fp);
  }
}
#endif // !NO_POPEN

static int mg_fgetc(struct file *filep, int offset) {
  if (filep->membuf != NULL && offset >=0 && offset < filep->size) {
    return ((unsigned char *) filep->membuf)[offset];
  } else if (filep->fp != NULL) {
    return fgetc(filep->fp);
  } else {
    return EOF;
  }
}

static void send_ssi_file(struct mg_connection *conn, const char *path,
                          struct file *filep, int include_level) {
  char buf[MG_BUF_LEN];
  int ch, offset, len, in_ssi_tag;

  if (include_level > 10) {
    cry(conn, "SSI #include level is too deep (%s)", path);
    return;
  }

  in_ssi_tag = len = offset = 0;
  while ((ch = mg_fgetc(filep, offset)) != EOF) {
    if (in_ssi_tag && ch == '>') {
      in_ssi_tag = 0;
      buf[len++] = (char) ch;
      buf[len] = '\0';
      assert(len <= (int) sizeof(buf));
      if (len < 6 || memcmp(buf, "|<--data_len-->|
    //     |<-conn->request_len->|<-----body_len----------->|
    //     |<-------------------conn->data_len------------->|

    if (header_len > 0) {
      // Allocate space to hold websocket payload
      data = mem;
      if (data_len > sizeof(mem) && (data = malloc(data_len)) == NULL) {
        // Allocation failed, exit the loop and then close the connection
        // TODO: notify user about the failure
        break;
      }

      // Save mask and bits, otherwise it may be clobbered by memmove below
      bits = buf[0];
      memcpy(mask, buf + header_len - mask_len, mask_len);

      // Read frame payload into the allocated buffer.
      assert(body_len >= header_len);
      if (data_len + header_len > body_len) {
        len = body_len - header_len;
        memcpy(data, buf + header_len, len);
        // TODO: handle pull error
        pull_all(NULL, conn, data + len, data_len - len);
        conn->data_len = conn->request_len;
      } else {
        len = data_len + header_len;
        memcpy(data, buf + header_len, data_len);
        memmove(buf, buf + len, body_len - len);
        conn->data_len -= len;
      }

      // Apply mask if necessary
      if (mask_len > 0) {
        for (i = 0; i < data_len; i++) {
          data[i] ^= mask[i % 4];
        }
      }

      // Exit the loop if callback signalled to exit,
      // or "connection close" opcode received.
      if ((bits & WEBSOCKET_OPCODE_CONNECTION_CLOSE) ||
          (conn->ctx->callbacks.websocket_data != NULL &&
           !conn->ctx->callbacks.websocket_data(conn, bits, data, data_len))) {
        stop = 1;
      }

      if (data != mem) {
        free(data);
      }
      // Not breaking the loop, process next websocket frame.
    } else {
      // Buffering websocket request
      if ((n = pull(NULL, conn, conn->buf + conn->data_len,
                    conn->buf_size - conn->data_len)) <= 0) {
        break;
      }
      conn->data_len += n;
    }
  }
}

int mg_websocket_write(struct mg_connection* conn, int opcode,
                       const char *data, size_t data_len) {
    unsigned char *copy;
    size_t copy_len = 0;
    int retval = -1;

    if ((copy = (unsigned char *) malloc(data_len + 10)) == NULL) {
      return -1;
    }

    copy[0] = 0x80 + (opcode & 0x0f);

    // Frame format: http://tools.ietf.org/html/rfc6455#section-5.2
    if (data_len < 126) {
      // Inline 7-bit length field
      copy[1] = data_len;
      memcpy(copy + 2, data, data_len);
      copy_len = 2 + data_len;
    } else if (data_len <= 0xFFFF) {
      // 16-bit length field
      copy[1] = 126;
      * (uint16_t *) (copy + 2) = htons(data_len);
      memcpy(copy + 4, data, data_len);
      copy_len = 4 + data_len;
    } else {
      // 64-bit length field
      copy[1] = 127;
      * (uint32_t *) (copy + 2) = htonl((uint64_t) data_len >> 32);
      * (uint32_t *) (copy + 6) = htonl(data_len & 0xffffffff);
      memcpy(copy + 10, data, data_len);
      copy_len = 10 + data_len;
    }

    // Not thread safe
    if (copy_len > 0) {
      retval = mg_write(conn, copy, copy_len);
    }
    free(copy);

    return retval;
}

static void handle_websocket_request(struct mg_connection *conn) {
  const char *version = mg_get_header(conn, "Sec-WebSocket-Version");
  if (version == NULL || strcmp(version, "13") != 0) {
    send_http_error(conn, 426, "Upgrade Required", "%s", "Upgrade Required");
  } else if (conn->ctx->callbacks.websocket_connect != NULL &&
             conn->ctx->callbacks.websocket_connect(conn) != 0) {
    // Callback has returned non-zero, do not proceed with handshake
  } else {
    send_websocket_handshake(conn);
    if (conn->ctx->callbacks.websocket_ready != NULL) {
      conn->ctx->callbacks.websocket_ready(conn);
    }
    read_websocket(conn);
  }
}

static int is_websocket_request(const struct mg_connection *conn) {
  const char *host, *upgrade, *connection, *version, *key;

  host = mg_get_header(conn, "Host");
  upgrade = mg_get_header(conn, "Upgrade");
  connection = mg_get_header(conn, "Connection");
  key = mg_get_header(conn, "Sec-WebSocket-Key");
  version = mg_get_header(conn, "Sec-WebSocket-Version");

  return host != NULL && upgrade != NULL && connection != NULL &&
    key != NULL && version != NULL &&
    mg_strcasestr(upgrade, "websocket") != NULL &&
    mg_strcasestr(connection, "Upgrade") != NULL;
}
#endif // !USE_WEBSOCKET

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;
}

static int set_throttle(const char *spec, uint32_t remote_ip, const char *uri) {
  int throttle = 0;
  struct vec vec, val;
  uint32_t net, mask;
  char mult;
  double v;

  while ((spec = next_option(spec, &vec, &val)) != NULL) {
    mult = ',';
    if (sscanf(val.ptr, "%lf%c", &v, &mult) < 1 || v < 0 ||
        (lowercase(&mult) != 'k' && lowercase(&mult) != 'm' && mult != ',')) {
      continue;
    }
    v *= lowercase(&mult) == 'k' ? 1024 : lowercase(&mult) == 'm' ? 1048576 : 1;
    if (vec.len == 1 && vec.ptr[0] == '*') {
      throttle = (int) v;
    } else if (parse_net(vec.ptr, &net, &mask) > 0) {
      if ((remote_ip & mask) == net) {
        throttle = (int) v;
      }
    } else if (match_prefix(vec.ptr, vec.len, uri) > 0) {
      throttle = (int) v;
    }
  }

  return throttle;
}

static uint32_t get_remote_ip(const struct mg_connection *conn) {
  return ntohl(* (uint32_t *) &conn->client.rsa.sin.sin_addr);
}

#ifdef USE_LUA
#include "build/mod_lua.c"
#endif // USE_LUA

int mg_upload(struct mg_connection *conn, const char *destination_dir) {
  const char *content_type_header, *boundary_start;
  char buf[MG_BUF_LEN], path[PATH_MAX], fname[1024], boundary[100], *s;
  FILE *fp;
  int bl, n, i, j, headers_len, boundary_len, eof,
      len = 0, num_uploaded_files = 0;

  // Request looks like this:
  //
  // POST /upload HTTP/1.1
  // Host: 127.0.0.1:8080
  // Content-Length: 244894
  // Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryRVr
  //
  // ------WebKitFormBoundaryRVr
  // Content-Disposition: form-data; name="file"; filename="accum.png"
  // Content-Type: image/png
  //
  //  <89>PNG
  //  
  // ------WebKitFormBoundaryRVr

  // Extract boundary string from the Content-Type header
  if ((content_type_header = mg_get_header(conn, "Content-Type")) == NULL ||
      (boundary_start = mg_strcasestr(content_type_header,
                                      "boundary=")) == NULL ||
      (sscanf(boundary_start, "boundary=\"%99[^\"]\"", boundary) == 0 &&
       sscanf(boundary_start, "boundary=%99s", boundary) == 0) ||
      boundary[0] == '\0') {
    return num_uploaded_files;
  }

  boundary_len = strlen(boundary);
  bl = boundary_len + 4;  // \r\n--
  for (;;) {
    // Pull in headers
    assert(len >= 0 && len <= (int) sizeof(buf));
    while ((n = mg_read(conn, buf + len, sizeof(buf) - len)) > 0) {
      len += n;
    }
    if ((headers_len = get_request_len(buf, len)) <= 0) {
      break;
    }

    // Fetch file name.
    fname[0] = '\0';
    for (i = j = 0; i < headers_len; i++) {
      if (buf[i] == '\r' && buf[i + 1] == '\n') {
        buf[i] = buf[i + 1] = '\0';
        // TODO(lsm): don't expect filename to be the 3rd field,
        // parse the header properly instead.
        sscanf(&buf[j], "Content-Disposition: %*s %*s filename=\"%1023[^\"]",
               fname);
        j = i + 2;
      }
    }

    // Give up if the headers are not what we expect
    if (fname[0] == '\0') {
      break;
    }

    // Move data to the beginning of the buffer
    assert(len >= headers_len);
    memmove(buf, &buf[headers_len], len - headers_len);
    len -= headers_len;

    // We open the file with exclusive lock held. This guarantee us
    // there is no other thread can save into the same file simultaneously.
    fp = NULL;
    // Construct destination file name. Do not allow paths to have slashes.
    if ((s = strrchr(fname, '/')) == NULL &&
        (s = strrchr(fname, '\\')) == NULL) {
      s = fname;
    }

    // Open file in binary mode. TODO: set an exclusive lock.
    snprintf(path, sizeof(path), "%s/%s", destination_dir, s);
    if ((fp = fopen(path, "wb")) == NULL) {
      break;
    }

    // Read POST data, write into file until boundary is found.
    eof = n = 0;
    do {
      len += n;
      for (i = 0; i < len - bl; i++) {
        if (!memcmp(&buf[i], "\r\n--", 4) &&
            !memcmp(&buf[i + 4], boundary, boundary_len)) {
          // Found boundary, that's the end of file data.
          fwrite(buf, 1, i, fp);
          eof = 1;
          memmove(buf, &buf[i + bl], len - (i + bl));
          len -= i + bl;
          break;
        }
      }
      if (!eof && len > bl) {
        fwrite(buf, 1, len - bl, fp);
        memmove(buf, &buf[len - bl], bl);
        len = bl;
      }
    } while (!eof && (n = mg_read(conn, buf + len, sizeof(buf) - len)) > 0);
    fclose(fp);
    if (eof) {
      num_uploaded_files++;
      if (conn->ctx->callbacks.upload != NULL) {
        conn->ctx->callbacks.upload(conn, path);
      }
    }
  }

  return num_uploaded_files;
}

static int is_put_or_delete_request(const struct mg_connection *conn) {
  const char *s = conn->request_info.request_method;
  return s != NULL && (!strcmp(s, "PUT") ||
                       !strcmp(s, "DELETE") ||
                       !strcmp(s, "MKCOL"));
}

static int get_first_ssl_listener_index(const struct mg_context *ctx) {
  int i, index = -1;
  for (i = 0; index == -1 && i < ctx->num_listening_sockets; i++) {
    index = ctx->listening_sockets[i].is_ssl ? i : -1;
  }
  return index;
}

static void redirect_to_https_port(struct mg_connection *conn, int ssl_index) {
  char host[1025];
  const char *host_header;

  if ((host_header = mg_get_header(conn, "Host")) == NULL ||
      sscanf(host_header, "%1024[^:]", host) == 0) {
    // Cannot get host from the Host: header. Fallback to our IP address.
    sockaddr_to_string(host, sizeof(host), &conn->client.lsa);
  }

  mg_printf(conn, "HTTP/1.1 302 Found\r\nLocation: https://%s:%d%s\r\n\r\n",
            host, (int) ntohs(conn->ctx->listening_sockets[ssl_index].
                              lsa.sin.sin_port), conn->request_info.uri);
}

// This is the heart of the Mongoose's logic.
// This function is called when the request is read, parsed and validated,
// and Mongoose must decide what action to take: serve a file, or
// a directory, or call embedded function, etcetera.
static void handle_request(struct mg_connection *conn) {
  struct mg_request_info *ri = &conn->request_info;
  char path[PATH_MAX];
  int uri_len, ssl_index;
  struct file file = STRUCT_FILE_INITIALIZER;

  if ((conn->request_info.query_string = strchr(ri->uri, '?')) != NULL) {
    * ((char *) conn->request_info.query_string++) = '\0';
  }
  uri_len = (int) strlen(ri->uri);
  mg_url_decode(ri->uri, uri_len, (char *) ri->uri, uri_len + 1, 0);
  remove_double_dots_and_double_slashes((char *) ri->uri);
  convert_uri_to_file_name(conn, path, sizeof(path), &file);
  conn->throttle = set_throttle(conn->ctx->config[THROTTLE],
                                get_remote_ip(conn), ri->uri);

  DEBUG_TRACE(("%s", ri->uri));
  // Perform redirect and auth checks before calling begin_request() handler.
  // Otherwise, begin_request() would need to perform auth checks and redirects.
  if (!conn->client.is_ssl && conn->client.ssl_redir &&
      (ssl_index = get_first_ssl_listener_index(conn->ctx)) > -1) {
    redirect_to_https_port(conn, ssl_index);
  } else if (!is_put_or_delete_request(conn) &&
             !check_authorization(conn, path)) {
    send_authorization_request(conn);
  } else if (conn->ctx->callbacks.begin_request != NULL &&
      conn->ctx->callbacks.begin_request(conn)) {
    // Do nothing, callback has served the request
#if defined(USE_WEBSOCKET)
  } else if (is_websocket_request(conn)) {
    handle_websocket_request(conn);
#endif
  } else if (!strcmp(ri->request_method, "OPTIONS")) {
    send_options(conn);
  } else if (conn->ctx->config[DOCUMENT_ROOT] == NULL) {
    send_http_error(conn, 404, "Not Found", "Not Found");
  } else if (is_put_or_delete_request(conn) &&
             (is_authorized_for_put(conn) != 1)) {
    send_authorization_request(conn);
  } else if (!strcmp(ri->request_method, "PUT")) {
    put_file(conn, path);
  } else if (!strcmp(ri->request_method, "MKCOL")) {
    mkcol(conn, path);
  } else if (!strcmp(ri->request_method, "DELETE")) {
      struct de de;
      memset(&de.file, 0, sizeof(de.file));
      if(!mg_stat(conn, path, &de.file)) {
          send_http_error(conn, 404, "Not Found", "%s", "File not found");
      } else {
          if(de.file.modification_time) {
              if(de.file.is_directory) {
                  remove_directory(conn, path);
                  send_http_error(conn, 204, "No Content", "%s", "");
              } else if (mg_remove(path) == 0) {
                  send_http_error(conn, 204, "No Content", "%s", "");
              } else {
                  send_http_error(conn, 423, "Locked", "remove(%s): %s", path,
                          strerror(ERRNO));
              }
          }
          else {
              send_http_error(conn, 500, http_500_error, "remove(%s): %s", path,
                    strerror(ERRNO));
          }
      }
  } else if ((file.membuf == NULL && file.modification_time == (time_t) 0) ||
             must_hide_file(conn, path)) {
    send_http_error(conn, 404, "Not Found", "%s", "File not found");
  } else if (file.is_directory && ri->uri[uri_len - 1] != '/') {
    mg_printf(conn, "HTTP/1.1 301 Moved Permanently\r\n"
              "Location: %s/\r\n\r\n", ri->uri);
  } else if (!strcmp(ri->request_method, "PROPFIND")) {
    handle_propfind(conn, path, &file);
  } else if (file.is_directory &&
             !substitute_index_file(conn, path, sizeof(path), &file)) {
    if (!mg_strcasecmp(conn->ctx->config[ENABLE_DIRECTORY_LISTING], "yes")) {
      handle_directory_request(conn, path);
    } else {
      send_http_error(conn, 403, "Directory Listing Denied",
          "Directory listing denied");
    }
#ifdef USE_LUA
  } else if (match_prefix("**.lp$", 6, path) > 0) {
    handle_lsp_request(conn, path, &file, NULL);
#endif
#if !defined(NO_CGI)
  } else if (match_prefix(conn->ctx->config[CGI_EXTENSIONS],
                          strlen(conn->ctx->config[CGI_EXTENSIONS]),
                          path) > 0) {
    if (strcmp(ri->request_method, "POST") &&
        strcmp(ri->request_method, "HEAD") &&
        strcmp(ri->request_method, "GET")) {
      send_http_error(conn, 501, "Not Implemented",
                      "Method %s is not implemented", ri->request_method);
    } else {
      handle_cgi_request(conn, path);
    }
#endif // !NO_CGI
  } else if (match_prefix(conn->ctx->config[SSI_EXTENSIONS],
                          strlen(conn->ctx->config[SSI_EXTENSIONS]),
                          path) > 0) {
    handle_ssi_file_request(conn, path);
  } else if (is_not_modified(conn, &file)) {
    send_http_error(conn, 304, "Not Modified", "%s", "");
  } else {
    handle_file_request(conn, path, &file);
  }
}

static void close_all_listening_sockets(struct mg_context *ctx) {
  int i;
  for (i = 0; i < ctx->num_listening_sockets; i++) {
    closesocket(ctx->listening_sockets[i].sock);
  }
  free(ctx->listening_sockets);
}

static int is_valid_port(unsigned int port) {
  return port > 0 && port < 0xffff;
}

// Valid listening port specification is: [ip_address:]port[s]
// Examples: 80, 443s, 127.0.0.1:3128, 1.2.3.4:8080s
// TODO(lsm): add parsing of the IPv6 address
static int parse_port_string(const struct vec *vec, struct socket *so) {
  unsigned int a, b, c, d, ch, len, port;
#if defined(USE_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(so, 0, sizeof(*so));
  so->lsa.sin.sin_family = AF_INET;

  if (sscanf(vec->ptr, "%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
    so->lsa.sin.sin_addr.s_addr = htonl((a << 24) | (b << 16) | (c << 8) | d);
    so->lsa.sin.sin_port = htons((uint16_t) port);
#if defined(USE_IPV6)

  } else if (sscanf(vec->ptr, "[%49[^]]]:%d%n", buf, &port, &len) == 2 &&
             inet_pton(AF_INET6, buf, &so->lsa.sin6.sin6_addr)) {
    // IPv6 address, e.g. [3ffe:2a00:100:7031::1]:8080
    so->lsa.sin6.sin6_family = AF_INET6;
    so->lsa.sin6.sin6_port = htons((uint16_t) port);
#endif
  } else if (sscanf(vec->ptr, "%u%n", &port, &len) == 1) {
    // If only port is specified, bind to IPv4, INADDR_ANY
    so->lsa.sin.sin_port = htons((uint16_t) port);
  } else {
    port = len = 0;   // Parsing failure. Make port invalid.
  }

  ch = vec->ptr[len];  // Next character after the port number
  so->is_ssl = ch == 's';
  so->ssl_redir = ch == 'r';

  // Make sure the port is valid and vector ends with 's', 'r' or ','
  return is_valid_port(port) &&
    (ch == '\0' || ch == 's' || ch == 'r' || ch == ',');
}

static int set_ports_option(struct mg_context *ctx) {
  const char *list = ctx->config[LISTENING_PORTS];
  int on = 1, success = 1;
#if defined(USE_IPV6)
  int off = 0;
#endif
  struct vec vec;
  struct socket so, *ptr;

  while (success && (list = next_option(list, &vec, NULL)) != NULL) {
    if (!parse_port_string(&vec, &so)) {
      cry(fc(ctx), "%s: %.*s: invalid port spec. Expecting list of: %s",
          __func__, (int) vec.len, vec.ptr, "[IP_ADDRESS:]PORT[s|r]");
      success = 0;
    } else if (so.is_ssl && ctx->ssl_ctx == NULL) {
      cry(fc(ctx), "Cannot add SSL socket, is -ssl_certificate option set?");
      success = 0;
    } else if ((so.sock = socket(so.lsa.sa.sa_family, SOCK_STREAM, 6)) ==
               INVALID_SOCKET ||
               // On Windows, SO_REUSEADDR is recommended only for
               // broadcast UDP sockets
               setsockopt(so.sock, SOL_SOCKET, SO_REUSEADDR,
                          (void *) &on, sizeof(on)) != 0 ||
#if defined(USE_IPV6)
               (so.lsa.sa.sa_family == AF_INET6 &&
                setsockopt(so.sock, IPPROTO_IPV6, IPV6_V6ONLY, (void *) &off,
                           sizeof(off)) != 0) ||
#endif
               bind(so.sock, &so.lsa.sa, so.lsa.sa.sa_family == AF_INET ?
                    sizeof(so.lsa.sin) : sizeof(so.lsa)) != 0 ||
               listen(so.sock, SOMAXCONN) != 0) {
      cry(fc(ctx), "%s: cannot bind to %.*s: %d (%s)", __func__,
          (int) vec.len, vec.ptr, ERRNO, strerror(errno));
      closesocket(so.sock);
      success = 0;
    } else if ((ptr = (struct socket *) realloc(ctx->listening_sockets,
                              (ctx->num_listening_sockets + 1) *
                              sizeof(ctx->listening_sockets[0]))) == NULL) {
      closesocket(so.sock);
      success = 0;
    } else {
      set_close_on_exec(so.sock);
      ctx->listening_sockets = ptr;
      ctx->listening_sockets[ctx->num_listening_sockets] = so;
      ctx->num_listening_sockets++;
    }
  }

  if (!success) {
    close_all_listening_sockets(ctx);
  }

  return success;
}

static void log_header(const struct mg_connection *conn, const char *header,
                       FILE *fp) {
  const char *header_value;

  if ((header_value = mg_get_header(conn, header)) == NULL) {
    (void) fprintf(fp, "%s", " -");
  } else {
    (void) fprintf(fp, " \"%s\"", header_value);
  }
}

static void log_access(const struct mg_connection *conn) {
  const struct mg_request_info *ri;
  FILE *fp;
  char date[64], src_addr[IP_ADDR_STR_LEN];

  fp = conn->ctx->config[ACCESS_LOG_FILE] == NULL ?  NULL :
    fopen(conn->ctx->config[ACCESS_LOG_FILE], "a+");

  if (fp == NULL)
    return;

  strftime(date, sizeof(date), "%d/%b/%Y:%H:%M:%S %z",
           localtime(&conn->birth_time));

  ri = &conn->request_info;
  flockfile(fp);

  sockaddr_to_string(src_addr, sizeof(src_addr), &conn->client.rsa);
  fprintf(fp, "%s - %s [%s] \"%s %s HTTP/%s\" %d %" INT64_FMT,
          src_addr, ri->remote_user == NULL ? "-" : ri->remote_user, date,
          ri->request_method ? ri->request_method : "-",
          ri->uri ? ri->uri : "-", ri->http_version,
          conn->status_code, conn->num_bytes_sent);
  log_header(conn, "Referer", fp);
  log_header(conn, "User-Agent", fp);
  fputc('\n', fp);
  fflush(fp);

  funlockfile(fp);
  fclose(fp);
}

// Verify given socket address against the ACL.
// Return -1 if ACL is malformed, 0 if address is disallowed, 1 if allowed.
static int check_acl(struct mg_context *ctx, uint32_t remote_ip) {
  int allowed, flag;
  uint32_t net, mask;
  struct vec vec;
  const char *list = ctx->config[ACCESS_CONTROL_LIST];

  // If any ACL is set, deny by default
  allowed = list == NULL ? '+' : '-';

  while ((list = next_option(list, &vec, NULL)) != NULL) {
    flag = vec.ptr[0];
    if ((flag != '+' && flag != '-') ||
        parse_net(&vec.ptr[1], &net, &mask) == 0) {
      cry(fc(ctx), "%s: subnet must be [+|-]x.x.x.x[/x]", __func__);
      return -1;
    }

    if (net == (remote_ip & mask)) {
      allowed = flag;
    }
  }

  return allowed == '+';
}

#if !defined(_WIN32)
static int set_uid_option(struct mg_context *ctx) {
  struct passwd *pw;
  const char *uid = ctx->config[RUN_AS_USER];
  int success = 0;

  if (uid == NULL) {
    success = 1;
  } else {
    if ((pw = getpwnam(uid)) == NULL) {
      cry(fc(ctx), "%s: unknown user [%s]", __func__, uid);
    } else if (setgid(pw->pw_gid) == -1) {
      cry(fc(ctx), "%s: setgid(%s): %s", __func__, uid, strerror(errno));
    } else if (setuid(pw->pw_uid) == -1) {
      cry(fc(ctx), "%s: setuid(%s): %s", __func__, uid, strerror(errno));
    } else {
      success = 1;
    }
  }

  return success;
}
#endif // !_WIN32

#if !defined(NO_SSL)
static pthread_mutex_t *ssl_mutexes;

static int sslize(struct mg_connection *conn, SSL_CTX *s, int (*func)(SSL *)) {
  return (conn->ssl = SSL_new(s)) != NULL &&
    SSL_set_fd(conn->ssl, conn->client.sock) == 1 &&
    func(conn->ssl) == 1;
}

// Return OpenSSL error message
static const char *ssl_error(void) {
  unsigned long err;
  err = ERR_get_error();
  return err == 0 ? "" : ERR_error_string(err, NULL);
}

static void ssl_locking_callback(int mode, int mutex_num, const char *file,
                                 int line) {
  (void) line;
  (void) file;

  if (mode & 1) {  // 1 is CRYPTO_LOCK
    (void) pthread_mutex_lock(&ssl_mutexes[mutex_num]);
  } else {
    (void) pthread_mutex_unlock(&ssl_mutexes[mutex_num]);
  }
}

static unsigned long ssl_id_callback(void) {
  return (unsigned long) pthread_self();
}

#if !defined(NO_SSL_DL)
static int load_dll(struct mg_context *ctx, const char *dll_name,
                    struct ssl_func *sw) {
  union {void *p; void (*fp)(void);} u;
  void  *dll_handle;
  struct ssl_func *fp;

  if ((dll_handle = dlopen(dll_name, RTLD_LAZY)) == NULL) {
    cry(fc(ctx), "%s: cannot load %s", __func__, dll_name);
    return 0;
  }

  for (fp = sw; fp->name != NULL; fp++) {
#ifdef _WIN32
    // GetProcAddress() returns pointer to function
    u.fp = (void (*)(void)) dlsym(dll_handle, fp->name);
#else
    // dlsym() on UNIX returns void *. ISO C forbids casts of data pointers to
    // function pointers. We need to use a union to make a cast.
    u.p = dlsym(dll_handle, fp->name);
#endif // _WIN32
    if (u.fp == NULL) {
      cry(fc(ctx), "%s: %s: cannot find %s", __func__, dll_name, fp->name);
      return 0;
    } else {
      fp->ptr = u.fp;
    }
  }

  return 1;
}
#endif // NO_SSL_DL

// Dynamically load SSL library. Set up ctx->ssl_ctx pointer.
static int set_ssl_option(struct mg_context *ctx) {
  int i, size;
  const char *pem;

  // If PEM file is not specified and the init_ssl callback
  // is not specified, skip SSL initialization.
  if ((pem = ctx->config[SSL_CERTIFICATE]) == NULL &&
      ctx->callbacks.init_ssl == NULL) {
    return 1;
  }

#if !defined(NO_SSL_DL)
  if (!load_dll(ctx, SSL_LIB, ssl_sw) ||
      !load_dll(ctx, CRYPTO_LIB, crypto_sw)) {
    return 0;
  }
#endif // NO_SSL_DL

  // Initialize SSL library
  SSL_library_init();
  SSL_load_error_strings();

  if ((ctx->ssl_ctx = SSL_CTX_new(SSLv23_server_method())) == NULL) {
    cry(fc(ctx), "SSL_CTX_new (server) error: %s", ssl_error());
    return 0;
  }

  // If user callback returned non-NULL, that means that user callback has
  // set up certificate itself. In this case, skip sertificate setting.
  if ((ctx->callbacks.init_ssl == NULL ||
       !ctx->callbacks.init_ssl(ctx->ssl_ctx, ctx->user_data)) &&
      (SSL_CTX_use_certificate_file(ctx->ssl_ctx, pem, 1) == 0 ||
       SSL_CTX_use_PrivateKey_file(ctx->ssl_ctx, pem, 1) == 0)) {
    cry(fc(ctx), "%s: cannot open %s: %s", __func__, pem, ssl_error());
    return 0;
  }

  if (pem != NULL) {
    (void) SSL_CTX_use_certificate_chain_file(ctx->ssl_ctx, pem);
  }

  // Initialize locking callbacks, needed for thread safety.
  // http://www.openssl.org/support/faq.html#PROG1
  size = sizeof(pthread_mutex_t) * CRYPTO_num_locks();
  if ((ssl_mutexes = (pthread_mutex_t *) malloc((size_t)size)) == NULL) {
    cry(fc(ctx), "%s: cannot allocate mutexes: %s", __func__, ssl_error());
    return 0;
  }

  for (i = 0; i < CRYPTO_num_locks(); i++) {
    pthread_mutex_init(&ssl_mutexes[i], NULL);
  }

  CRYPTO_set_locking_callback(&ssl_locking_callback);
  CRYPTO_set_id_callback(&ssl_id_callback);

  return 1;
}

static void uninitialize_ssl(struct mg_context *ctx) {
  int i;
  if (ctx->ssl_ctx != NULL) {
    CRYPTO_set_locking_callback(NULL);
    for (i = 0; i < CRYPTO_num_locks(); i++) {
      pthread_mutex_destroy(&ssl_mutexes[i]);
    }
    CRYPTO_set_locking_callback(NULL);
    CRYPTO_set_id_callback(NULL);
  }
}
#endif // !NO_SSL

static int set_gpass_option(struct mg_context *ctx) {
  struct file file = STRUCT_FILE_INITIALIZER;
  const char *path = ctx->config[GLOBAL_PASSWORDS_FILE];
  if (path != NULL && !mg_stat(fc(ctx), path, &file)) {
    cry(fc(ctx), "Cannot open %s: %s", path, strerror(ERRNO));
    return 0;
  }
  return 1;
}

static int set_acl_option(struct mg_context *ctx) {
  return check_acl(ctx, (uint32_t) 0x7f000001UL) != -1;
}

static void reset_per_request_attributes(struct mg_connection *conn) {
  conn->path_info = NULL;
  conn->num_bytes_sent = conn->consumed_content = 0;
  conn->status_code = -1;
  conn->must_close = conn->request_len = conn->throttle = 0;
}

static void close_socket_gracefully(struct mg_connection *conn) {
#if defined(_WIN32)
  char buf[MG_BUF_LEN];
  int n;
#endif
  struct linger linger;

  // Set linger option to avoid socket hanging out after close. This prevent
  // ephemeral port exhaust problem under high QPS.
  linger.l_onoff = 1;
  linger.l_linger = 1;
  setsockopt(conn->client.sock, SOL_SOCKET, SO_LINGER,
             (char *) &linger, sizeof(linger));

  // Send FIN to the client
  shutdown(conn->client.sock, SHUT_WR);
  set_non_blocking_mode(conn->client.sock);

#if defined(_WIN32)
  // Read and discard pending incoming data. If we do not do that and close the
  // socket, the data in the send buffer may be discarded. This
  // behaviour is seen on Windows, when client keeps sending data
  // when server decides to close the connection; then when client
  // does recv() it gets no data back.
  do {
    n = pull(NULL, conn, buf, sizeof(buf));
  } while (n > 0);
#endif

  // Now we know that our FIN is ACK-ed, safe to close
  closesocket(conn->client.sock);
}

static void close_connection(struct mg_connection *conn) {
  conn->must_close = 1;

#ifndef NO_SSL
  if (conn->ssl != NULL) {
    // Run SSL_shutdown twice to ensure completly close SSL connection
    SSL_shutdown(conn->ssl);
    SSL_free(conn->ssl);
    conn->ssl = NULL;
  }
#endif
  if (conn->client.sock != INVALID_SOCKET) {
    close_socket_gracefully(conn);
    conn->client.sock = INVALID_SOCKET;
  }
}

void mg_close_connection(struct mg_connection *conn) {
#ifndef NO_SSL
  if (conn->client_ssl_ctx != NULL) {
    SSL_CTX_free((SSL_CTX *) conn->client_ssl_ctx);
  }
#endif
  close_connection(conn);
  free(conn);
}

struct mg_connection *mg_connect(const char *host, int port, int use_ssl,
                                 char *ebuf, size_t ebuf_len) {
  static struct mg_context fake_ctx;
  struct mg_connection *conn = NULL;
  SOCKET sock;

  if ((sock = conn2(host, port, use_ssl, ebuf, ebuf_len)) == INVALID_SOCKET) {
  } else if ((conn = (struct mg_connection *)
              calloc(1, sizeof(*conn) + MAX_REQUEST_SIZE)) == NULL) {
    snprintf(ebuf, ebuf_len, "calloc(): %s", strerror(ERRNO));
    closesocket(sock);
#ifndef NO_SSL
  } else if (use_ssl && (conn->client_ssl_ctx =
                         SSL_CTX_new(SSLv23_client_method())) == NULL) {
    snprintf(ebuf, ebuf_len, "SSL_CTX_new error");
    closesocket(sock);
    free(conn);
    conn = NULL;
#endif // NO_SSL
  } else {
    socklen_t len = sizeof(struct sockaddr);
    conn->buf_size = MAX_REQUEST_SIZE;
    conn->buf = (char *) (conn + 1);
    conn->ctx = &fake_ctx;
    conn->client.sock = sock;
    getsockname(sock, &conn->client.rsa.sa, &len);
    conn->client.is_ssl = use_ssl;
#ifndef NO_SSL
    if (use_ssl) {
      // SSL_CTX_set_verify call is needed to switch off server certificate
      // checking, which is off by default in OpenSSL and on in yaSSL.
      SSL_CTX_set_verify(conn->client_ssl_ctx, 0, 0);
      sslize(conn, conn->client_ssl_ctx, SSL_connect);
    }
#endif
  }

  return conn;
}

static int is_valid_uri(const char *uri) {
  // Conform to http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1.2
  // URI can be an asterisk (*) or should start with slash.
  return uri[0] == '/' || (uri[0] == '*' && uri[1] == '\0');
}

static int getreq(struct mg_connection *conn, char *ebuf, size_t ebuf_len) {
  const char *cl;

  ebuf[0] = '\0';
  reset_per_request_attributes(conn);
  conn->request_len = read_request(NULL, conn, conn->buf, conn->buf_size,
                                   &conn->data_len);
  assert(conn->request_len < 0 || conn->data_len >= conn->request_len);

  if (conn->request_len == 0 && conn->data_len == conn->buf_size) {
    snprintf(ebuf, ebuf_len, "%s", "Request Too Large");
  } else if (conn->request_len <= 0) {
    snprintf(ebuf, ebuf_len, "%s", "Client closed connection");
  } else if (parse_http_message(conn->buf, conn->buf_size,
                                &conn->request_info) <= 0) {
    snprintf(ebuf, ebuf_len, "Bad request: [%.*s]", conn->data_len, conn->buf);
  } else {
    // Request is valid
    if ((cl = get_header(&conn->request_info, "Content-Length")) != NULL) {
      conn->content_len = strtoll(cl, NULL, 10);
    } else if (!mg_strcasecmp(conn->request_info.request_method, "POST") ||
               !mg_strcasecmp(conn->request_info.request_method, "PUT")) {
      conn->content_len = -1;
    } else {
      conn->content_len = 0;
    }
    conn->birth_time = time(NULL);
  }
  return ebuf[0] == '\0';
}

struct mg_connection *mg_download(const char *host, int port, int use_ssl,
                                  char *ebuf, size_t ebuf_len,
                                  const char *fmt, ...) {
  struct mg_connection *conn;
  va_list ap;

  va_start(ap, fmt);
  ebuf[0] = '\0';
  if ((conn = mg_connect(host, port, use_ssl, ebuf, ebuf_len)) == NULL) {
  } else if (mg_vprintf(conn, fmt, ap) <= 0) {
    snprintf(ebuf, ebuf_len, "%s", "Error sending request");
  } else {
    getreq(conn, ebuf, ebuf_len);
  }
  if (ebuf[0] != '\0' && conn != NULL) {
    mg_close_connection(conn);
    conn = NULL;
  }

  return conn;
}

static void process_new_connection(struct mg_connection *conn) {
  struct mg_request_info *ri = &conn->request_info;
  int keep_alive_enabled, keep_alive, discard_len;
  char ebuf[100];

  keep_alive_enabled = !strcmp(conn->ctx->config[ENABLE_KEEP_ALIVE], "yes");
  keep_alive = 0;

  // Important: on new connection, reset the receiving buffer. Credit goes
  // to crule42.
  conn->data_len = 0;
  do {
    if (!getreq(conn, ebuf, sizeof(ebuf))) {
      send_http_error(conn, 500, "Server Error", "%s", ebuf);
      conn->must_close = 1;
    } else if (!is_valid_uri(conn->request_info.uri)) {
      snprintf(ebuf, sizeof(ebuf), "Invalid URI: [%s]", ri->uri);
      send_http_error(conn, 400, "Bad Request", "%s", ebuf);
    } else if (strcmp(ri->http_version, "1.0") &&
               strcmp(ri->http_version, "1.1")) {
      snprintf(ebuf, sizeof(ebuf), "Bad HTTP version: [%s]", ri->http_version);
      send_http_error(conn, 505, "Bad HTTP version", "%s", ebuf);
    }

    if (ebuf[0] == '\0') {
      handle_request(conn);
      if (conn->ctx->callbacks.end_request != NULL) {
        conn->ctx->callbacks.end_request(conn, conn->status_code);
      }
      log_access(conn);
    }
    if (ri->remote_user != NULL) {
      free((void *) ri->remote_user);
      // Important! When having connections with and without auth
      // would cause double free and then crash
      ri->remote_user = NULL;
    }

    // NOTE(lsm): order is important here. should_keep_alive() call
    // is using parsed request, which will be invalid after memmove's below.
    // Therefore, memorize should_keep_alive() result now for later use
    // in loop exit condition.
    keep_alive = conn->ctx->stop_flag == 0 && keep_alive_enabled &&
      conn->content_len >= 0 && should_keep_alive(conn);

    // Discard all buffered data for this request
    discard_len = conn->content_len >= 0 && conn->request_len > 0 &&
      conn->request_len + conn->content_len < (int64_t) conn->data_len ?
      (int) (conn->request_len + conn->content_len) : conn->data_len;
    assert(discard_len >= 0);
    memmove(conn->buf, conn->buf + discard_len, conn->data_len - discard_len);
    conn->data_len -= discard_len;
    assert(conn->data_len >= 0);
    assert(conn->data_len <= conn->buf_size);
  } while (keep_alive);
}

// Worker threads take accepted socket from the queue
static int consume_socket(struct mg_context *ctx, struct socket *sp) {
  (void) pthread_mutex_lock(&ctx->mutex);
  DEBUG_TRACE(("going idle"));

  // If the queue is empty, wait. We're idle at this point.
  while (ctx->sq_head == ctx->sq_tail && ctx->stop_flag == 0) {
    pthread_cond_wait(&ctx->sq_full, &ctx->mutex);
  }

  // If we're stopping, sq_head may be equal to sq_tail.
  if (ctx->sq_head > ctx->sq_tail) {
    // Copy socket from the queue and increment tail
    *sp = ctx->queue[ctx->sq_tail % ARRAY_SIZE(ctx->queue)];
    ctx->sq_tail++;
    DEBUG_TRACE(("grabbed socket %d, going busy", sp->sock));

    // Wrap pointers if needed
    while (ctx->sq_tail > (int) ARRAY_SIZE(ctx->queue)) {
      ctx->sq_tail -= ARRAY_SIZE(ctx->queue);
      ctx->sq_head -= ARRAY_SIZE(ctx->queue);
    }
  }

  (void) pthread_cond_signal(&ctx->sq_empty);
  (void) pthread_mutex_unlock(&ctx->mutex);

  return !ctx->stop_flag;
}

static void *worker_thread(void *thread_func_param) {
  struct mg_context *ctx = (struct mg_context *) thread_func_param;
  struct mg_connection *conn;

  conn = (struct mg_connection *) calloc(1, sizeof(*conn) + MAX_REQUEST_SIZE);
  if (conn == NULL) {
    cry(fc(ctx), "%s", "Cannot create new connection struct, OOM");
  } else {
    conn->buf_size = MAX_REQUEST_SIZE;
    conn->buf = (char *) (conn + 1);
    conn->ctx = ctx;
    conn->request_info.user_data = ctx->user_data;

    if (ctx->callbacks.thread_start != NULL) {
      ctx->callbacks.thread_start(&conn->request_info.user_data,
                                  &conn->request_info.conn_data);
    }

    // Call consume_socket() even when ctx->stop_flag > 0, to let it signal
    // sq_empty condvar to wake up the master waiting in produce_socket()
    while (consume_socket(ctx, &conn->client)) {
      conn->birth_time = time(NULL);

      // Fill in IP, port info early so even if SSL setup below fails,
      // error handler would have the corresponding info.
      // Thanks to Johannes Winkelmann for the patch.
      // TODO(lsm): Fix IPv6 case
      conn->request_info.remote_port = ntohs(conn->client.rsa.sin.sin_port);
      memcpy(&conn->request_info.remote_ip,
             &conn->client.rsa.sin.sin_addr.s_addr, 4);
      conn->request_info.remote_ip = ntohl(conn->request_info.remote_ip);
      conn->request_info.is_ssl = conn->client.is_ssl;

      if (!conn->client.is_ssl
#ifndef NO_SSL
          || sslize(conn, conn->ctx->ssl_ctx, SSL_accept)
#endif
         ) {
        process_new_connection(conn);
      }

      close_connection(conn);
    }
    if (ctx->callbacks.thread_stop != NULL) {
      ctx->callbacks.thread_stop(&conn->request_info.user_data,
                                 &conn->request_info.conn_data);
    }
    free(conn);
  }

  // Signal master that we're done with connection and exiting
  (void) pthread_mutex_lock(&ctx->mutex);
  ctx->num_threads--;
  (void) pthread_cond_signal(&ctx->cond);
  assert(ctx->num_threads >= 0);
  (void) pthread_mutex_unlock(&ctx->mutex);

  DEBUG_TRACE(("exiting"));
  return NULL;
}

// Master thread adds accepted socket to a queue
static void produce_socket(struct mg_context *ctx, const struct socket *sp) {
  (void) pthread_mutex_lock(&ctx->mutex);

  // If the queue is full, wait
  while (ctx->stop_flag == 0 &&
         ctx->sq_head - ctx->sq_tail >= (int) ARRAY_SIZE(ctx->queue)) {
    (void) pthread_cond_wait(&ctx->sq_empty, &ctx->mutex);
  }

  if (ctx->sq_head - ctx->sq_tail < (int) ARRAY_SIZE(ctx->queue)) {
    // Copy socket to the queue and increment head
    ctx->queue[ctx->sq_head % ARRAY_SIZE(ctx->queue)] = *sp;
    ctx->sq_head++;
    DEBUG_TRACE(("queued socket %d", sp->sock));
  }

  (void) pthread_cond_signal(&ctx->sq_full);
  (void) pthread_mutex_unlock(&ctx->mutex);
}

static int set_sock_timeout(SOCKET sock, int milliseconds) {
#ifdef _WIN32
  DWORD t = milliseconds;
#else
  struct timeval t;
  t.tv_sec = milliseconds / 1000;
  t.tv_usec = (milliseconds * 1000) % 1000000;
#endif
  return setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (void *) &t, sizeof(t)) ||
    setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, (void *) &t, sizeof(t));
}

static void accept_new_connection(const struct socket *listener,
                                  struct mg_context *ctx) {
  struct socket so;
  char src_addr[IP_ADDR_STR_LEN];
  socklen_t len = sizeof(so.rsa);
  int on = 1;

  if ((so.sock = accept(listener->sock, &so.rsa.sa, &len)) == INVALID_SOCKET) {
  } else if (!check_acl(ctx, ntohl(* (uint32_t *) &so.rsa.sin.sin_addr))) {
    sockaddr_to_string(src_addr, sizeof(src_addr), &so.rsa);
    cry(fc(ctx), "%s: %s is not allowed to connect", __func__, src_addr);
    closesocket(so.sock);
  } else {
    // Put so socket structure into the queue
    DEBUG_TRACE(("Accepted socket %d", (int) so.sock));
    set_close_on_exec(so.sock);
    so.is_ssl = listener->is_ssl;
    so.ssl_redir = listener->ssl_redir;
    getsockname(so.sock, &so.lsa.sa, &len);
    // Set TCP keep-alive. This is needed because if HTTP-level keep-alive
    // is enabled, and client resets the connection, server won't get
    // TCP FIN or RST and will keep the connection open forever. With TCP
    // keep-alive, next keep-alive handshake will figure out that the client
    // is down and will close the server end.
    // Thanks to Igor Klopov who suggested the patch.
    setsockopt(so.sock, SOL_SOCKET, SO_KEEPALIVE, (void *) &on, sizeof(on));
    set_sock_timeout(so.sock, atoi(ctx->config[REQUEST_TIMEOUT]));
    produce_socket(ctx, &so);
  }
}

static void *master_thread(void *thread_func_param) {
  struct mg_context *ctx = (struct mg_context *) thread_func_param;
  struct pollfd *pfd;
  int i;

  // Increase priority of the master thread
#if defined(_WIN32)
  SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_ABOVE_NORMAL);
#endif

#if defined(ISSUE_317)
  struct sched_param sched_param;
  sched_param.sched_priority = sched_get_priority_max(SCHED_RR);
  pthread_setschedparam(pthread_self(), SCHED_RR, &sched_param);
#endif

  if (ctx->callbacks.thread_start != NULL) {
    ctx->callbacks.thread_start(&ctx->user_data, NULL);
  }

  pfd = (struct pollfd *) calloc(ctx->num_listening_sockets, sizeof(pfd[0]));
  while (pfd != NULL && ctx->stop_flag == 0) {
    for (i = 0; i < ctx->num_listening_sockets; i++) {
      pfd[i].fd = ctx->listening_sockets[i].sock;
      pfd[i].events = POLLIN;
    }

    if (poll(pfd, ctx->num_listening_sockets, 200) > 0) {
      for (i = 0; i < ctx->num_listening_sockets; i++) {
        // NOTE(lsm): on QNX, poll() returns POLLRDNORM after the
        // successfull poll, and POLLIN is defined as (POLLRDNORM | POLLRDBAND)
        // Therefore, we're checking pfd[i].revents & POLLIN, not
        // pfd[i].revents == POLLIN.
        if (ctx->stop_flag == 0 && (pfd[i].revents & POLLIN)) {
          accept_new_connection(&ctx->listening_sockets[i], ctx);
        }
      }
    }
  }
  free(pfd);
  DEBUG_TRACE(("stopping workers"));

  // Stop signal received: somebody called mg_stop. Quit.
  close_all_listening_sockets(ctx);

  // Wakeup workers that are waiting for connections to handle.
  pthread_cond_broadcast(&ctx->sq_full);

  // Wait until all threads finish
  (void) pthread_mutex_lock(&ctx->mutex);
  while (ctx->num_threads > 0) {
    (void) pthread_cond_wait(&ctx->cond, &ctx->mutex);
  }
  (void) pthread_mutex_unlock(&ctx->mutex);

  // All threads exited, no sync is needed. Destroy mutex and condvars
  (void) pthread_mutex_destroy(&ctx->mutex);
  (void) pthread_cond_destroy(&ctx->cond);
  (void) pthread_cond_destroy(&ctx->sq_empty);
  (void) pthread_cond_destroy(&ctx->sq_full);

#if !defined(NO_SSL)
  uninitialize_ssl(ctx);
#endif
  DEBUG_TRACE(("exiting"));

  if (ctx->callbacks.thread_stop != NULL) {
    ctx->callbacks.thread_stop(&ctx->user_data, NULL);
  }

  // Signal mg_stop() that we're done.
  // WARNING: This must be the very last thing this
  // thread does, as ctx becomes invalid after this line.
  ctx->stop_flag = 2;
  return NULL;
}

static void free_context(struct mg_context *ctx) {
  int i;

  // Deallocate config parameters
  for (i = 0; i < NUM_OPTIONS; i++) {
    if (ctx->config[i] != NULL)
      free(ctx->config[i]);
  }

#ifndef NO_SSL
  // Deallocate SSL context
  if (ctx->ssl_ctx != NULL) {
    SSL_CTX_free(ctx->ssl_ctx);
  }
  if (ssl_mutexes != NULL) {
    free(ssl_mutexes);
    ssl_mutexes = NULL;
  }
#endif // !NO_SSL

  // Deallocate context itself
  free(ctx);
}

void mg_stop(struct mg_context *ctx) {
  ctx->stop_flag = 1;

  // Wait until mg_fini() stops
  while (ctx->stop_flag != 2) {
    (void) mg_sleep(10);
  }
  free_context(ctx);

#if defined(_WIN32) && !defined(__SYMBIAN32__)
  (void) WSACleanup();
#endif // _WIN32
}

struct mg_context *mg_start(const struct mg_callbacks *callbacks,
                            void *user_data,
                            const char **options) {
  struct mg_context *ctx;
  const char *name, *value, *default_value;
  int i;

#if defined(_WIN32) && !defined(__SYMBIAN32__)
  WSADATA data;
  WSAStartup(MAKEWORD(2,2), &data);
#endif // _WIN32

  // Allocate context and initialize reasonable general case defaults.
  // TODO(lsm): do proper error handling here.
  if ((ctx = (struct mg_context *) calloc(1, sizeof(*ctx))) == NULL) {
    return NULL;
  }
  ctx->callbacks = *callbacks;
  ctx->user_data = user_data;

  while (options && (name = *options++) != NULL) {
    if ((i = get_option_index(name)) == -1) {
      cry(fc(ctx), "Invalid option: %s", name);
      free_context(ctx);
      return NULL;
    } else if ((value = *options++) == NULL) {
      cry(fc(ctx), "%s: option value cannot be NULL", name);
      free_context(ctx);
      return NULL;
    }
    if (ctx->config[i] != NULL) {
      cry(fc(ctx), "warning: %s: duplicate option", name);
      free(ctx->config[i]);
    }
    ctx->config[i] = mg_strdup(value);
    DEBUG_TRACE(("[%s] -> [%s]", name, value));
  }

  // Set default value if needed
  for (i = 0; config_options[i * 2] != NULL; i++) {
    default_value = config_options[i * 2 + 1];
    if (ctx->config[i] == NULL && default_value != NULL) {
      ctx->config[i] = mg_strdup(default_value);
    }
  }

  // NOTE(lsm): order is important here. SSL certificates must
  // be initialized before listening ports. UID must be set last.
  if (!set_gpass_option(ctx) ||
#if !defined(NO_SSL)
      !set_ssl_option(ctx) ||
#endif
      !set_ports_option(ctx) ||
#if !defined(_WIN32)
      !set_uid_option(ctx) ||
#endif
      !set_acl_option(ctx)) {
    free_context(ctx);
    return NULL;
  }

#if !defined(_WIN32) && !defined(__SYMBIAN32__)
  // Ignore SIGPIPE signal, so if browser cancels the request, it
  // won't kill the whole process.
  (void) signal(SIGPIPE, SIG_IGN);
#endif // !_WIN32

  (void) pthread_mutex_init(&ctx->mutex, NULL);
  (void) pthread_cond_init(&ctx->cond, NULL);
  (void) pthread_cond_init(&ctx->sq_empty, NULL);
  (void) pthread_cond_init(&ctx->sq_full, NULL);

  // Start master (listening) thread
  mg_start_thread(master_thread, ctx);

  // Start worker threads
  for (i = 0; i < atoi(ctx->config[NUM_THREADS]); i++) {
    if (mg_start_thread(worker_thread, ctx) != 0) {
      cry(fc(ctx), "Cannot start worker thread: %ld", (long) ERRNO);
    } else {
      ctx->num_threads++;
    }
  }

  return ctx;
}