/* * ===================================================================================== * * Filename: webserv.c * * Description: Web server for managing the web interface of the module * * Version: 0.1 * Created: 05/10/2010 14:12:24 * Revision: none * Compiler: gcc * * Author: BlackLight (http://0x00.ath.cx), * Licence: GNU GPL v.3 * Company: DO WHAT YOU WANT CAUSE A PIRATE IS FREE, YOU ARE A PIRATE! * * ===================================================================================== */ #include "spp_ai.h" #include #include #include #include #include #include #include /** \defgroup webserv Web server managing the web interface of the module * @{ */ #define HTTP_RESPONSE_HEADERS_FORMAT "%s %d %s\r\n" \ "Date: %s\r\n" \ "Server: %s\r\n" \ "Content-Type: %s\r\n" \ "Content-Length: %u\r\n\r\n" #define HTTP_ERR_RESPONSE_FORMAT "\n" \ "\n" \ "%u %s\n" \ "\n" \ "

%s

\n" \ "

\n" \ "%s\n" \ "\n\n" /** * \brief Escape a string to be used or included in an URL * \param str String to be escaped * \param out Pointer to the string containing the output (its length must be at least 3*length(str) + 2) * \param str_len Length of the input string * \return The length of the output string after the operation */ size_t __AI_url_escape ( char *str, char **out, size_t str_len ) { char escape_seq[5] = { 0 }; size_t i, out_len = 0; for ( i=0; i < str_len; i++ ) { if ( ( str[i] >= 'a' && str[i] <= 'z' ) || ( str[i] >= 'A' && str[i] <= 'Z' ) || ( str[i] >= '0' && str[i] <= '9' ) || str[i] == '_' || str[i] == '.' || str[i] == '/' || str[i] == '?' || str[i] == '=' ) { (*out)[out_len++] = str[i]; } else { snprintf ( escape_seq, sizeof ( escape_seq ), "%%%.2X", str[i] ); (*out)[out_len++] = escape_seq[0]; (*out)[out_len++] = escape_seq[1]; (*out)[out_len++] = escape_seq[2]; } } (*out)[out_len] = 0; return out_len; } /* ----- end of function __AI_url_escape ----- */ /** * \brief Unescape a string in URL format * \param str String to be unescaped * \param out Pointer to the string containing the output (its length must be at least the same of str + 1) * \param str_len Length of the input string * \return The length of the output string after the operation */ PRIVATE size_t __AI_url_unescape ( char *str, char **out, size_t str_len ) { char escape_seq[5] = { 0 }; size_t i, out_len = 0; for ( i=0; i < str_len; i++ ) { if ( str[i] == '%' && i < str_len-2 ) { if ( (( str[i+1] >= '0' && str[i+1] <= '9' ) || ( str[i+1] >= 'a' && str[i+1] <= 'z' ) || ( str[i+1] >= 'A' && str[i+1] <= 'Z' )) && (( str[i+2] >= '0' && str[i+2] <= '9' ) || ( str[i+2] >= 'a' && str[i+2] <= 'z' ) || ( str[i+2] >= 'A' && str[i+2] <= 'Z' ))) { escape_seq[0] = str[i+1]; escape_seq[1] = str[i+2]; escape_seq[2] = 0; (*out)[out_len++] = (char) strtoul ( escape_seq, NULL, 16 ); i += 2; continue; } } (*out)[out_len++] = str[i]; } (*out)[out_len] = 0; return out_len; } /* ----- end of function __AI_url_unescape ----- */ /** * \brief Read a line from a file descriptor * \param fp FILE descriptor * \return A char* pointer to the read line (to be free-ed!!!) */ PRIVATE char* __AI_getline ( FILE *fp ) { char ch; char *line = NULL; int nbytes = 1; if ( !feof ( fp )) { while (( ch = fgetc ( fp )) != '\n' && ch != '\0' && !feof ( fp )) { if ( ch == '\r' ) continue; if ( !( line = (char*) realloc ( line, ++nbytes ))) { AI_fatal_err ( "Fatal dynamic memory allocation", __FILE__, __LINE__ ); } line[ nbytes - 2 ] = ch; } } if ( nbytes > 1 ) { line[ nbytes - 1 ] = 0; } return line; } /* ----- end of function __AI_getline ----- */ /** * \brief Manage a client connection * \param arg void* reference to the client socket */ PRIVATE void* __AI_webservlet_thread ( void *arg ) { time_t ltime = time ( NULL ); struct stat st; FILE *sock = NULL, *fp = NULL; int i, *sd = (int*) arg, nlines = 0, nmatches = 0, max_content_length = 0, max_headers_length = 0, req_file_absolute_path_size = 0; char *line = NULL, *unescaped = NULL, *http_response = NULL, *http_headers = NULL, *strtime = NULL, **matches = NULL, *req_file_absolute_path = NULL, content_type[108] = { 0 }, extension[100] = { 0 }, http_ver[10] = { 0 }, req_file[1024] = { 0 }; max_content_length = strlen ( HTTP_ERR_RESPONSE_FORMAT ) + strlen ( config->webserv_banner ) + 1000; max_headers_length = strlen ( HTTP_RESPONSE_HEADERS_FORMAT ) + strlen ( config->webserv_banner ) + 1000; if ( !( http_response = (char*) alloca ( max_content_length ))) { pthread_exit ((void*) 0); return (void*) 0; } if ( !( http_headers = (char*) alloca ( max_headers_length ))) { pthread_exit ((void*) 0); return (void*) 0; } if ( !( sock = fdopen ( *sd, "r+" ))) { pthread_exit ((void*) 0); return (void*) 0; } req_file_absolute_path_size = sizeof ( req_file ) + strlen ( config->webserv_dir ) + 1; if ( !( req_file_absolute_path = (char*) alloca ( req_file_absolute_path_size ))) { pthread_exit ((void*) 0); return (void*) 0; } for ( nlines=0; ( line = __AI_getline ( sock )); nlines++ ) { if ( preg_match ( "^\\s*GET\\s+(/[^ ]*)\\s*(HTTP/[0-9]\\.[0-9])?", line, &matches, &nmatches ) > 0 ) { if ( strlen ( matches[1] ) > 0 ) { strncpy ( http_ver, matches[1], sizeof ( http_ver )); } else { strncpy ( http_ver, "HTTP/1.0", sizeof ( http_ver )); } if ( !strcmp ( matches[0], "/" )) { free ( matches[0] ); matches[0] = strdup ( "/index.html" ); } snprintf ( req_file_absolute_path, req_file_absolute_path_size, "%s%s", config->webserv_dir, matches[0] ); if ( strcmp ( http_ver, "HTTP/1.0" ) && strcmp ( http_ver, "HTTP/1.1" )) { snprintf ( http_response, max_content_length, HTTP_ERR_RESPONSE_FORMAT, 400, "Bad Request", "Bad Request", "The request could not be understood by the server due to malformed syntax", config->webserv_banner ); ltime = time ( NULL ); strtime = strdup ( ctime ( <ime )); strtime [ strlen(strtime) - 1 ] = 0; snprintf ( http_headers, max_headers_length, HTTP_RESPONSE_HEADERS_FORMAT, "HTTP/1.1", 400, "Bad Request", strtime, config->webserv_banner, "text/html", strlen ( http_response )); free ( strtime ); free ( line ); line = NULL; continue; } for ( i=0; i < nmatches; i++ ) { free ( matches[i] ); } free ( matches ); matches = NULL; if ( !( unescaped = (char*) alloca ( strlen ( req_file_absolute_path ) + 2 ))) { pthread_exit ((void*) 0); return (void*) 0; } /* Avoid directory traversal */ __AI_url_unescape ( req_file_absolute_path, &unescaped, strlen ( req_file_absolute_path )); unescaped = str_replace_all ( unescaped, "../", "" ); strncpy ( req_file_absolute_path, unescaped, req_file_absolute_path_size ); free ( unescaped ); if ( stat ( req_file_absolute_path, &st ) < 0 ) { snprintf ( http_response, max_content_length, HTTP_ERR_RESPONSE_FORMAT, 404, "Not Found", "Not Found", "The requested resource was not found on the server", config->webserv_banner ); ltime = time ( NULL ); strtime = strdup ( ctime ( <ime )); strtime [ strlen(strtime) - 1 ] = 0; snprintf ( http_headers, max_headers_length, HTTP_RESPONSE_HEADERS_FORMAT, http_ver, 404, "Not Found", strtime, config->webserv_banner, "text/html", strlen ( http_response )); free ( strtime ); free ( line ); line = NULL; continue; } if ( !( fp = fopen ( req_file_absolute_path, "r" ))) { snprintf ( http_response, max_content_length, HTTP_ERR_RESPONSE_FORMAT, 403, "Forbidden", "Forbidden", "The client does not have enough permissions for accessing the requested resource on the server", config->webserv_banner ); ltime = time ( NULL ); strtime = strdup ( ctime ( <ime )); strtime [ strlen(strtime) - 1 ] = 0; snprintf ( http_headers, max_headers_length, HTTP_RESPONSE_HEADERS_FORMAT, http_ver, 403, "Forbidden", strtime, config->webserv_banner, "text/html", strlen ( http_response )); free ( strtime ); free ( line ); line = NULL; continue; } if ( preg_match ( "\\.([a-zA-Z0-9]+)$", req_file_absolute_path, &matches, &nmatches ) > 0 ) { if ( strlen ( matches[0] ) < sizeof ( extension )) { strncpy ( extension, matches[0], sizeof ( extension )); } } if ( !strcasecmp ( extension, "html" )) { strncpy ( content_type, "text/html", sizeof ( content_type )); } else if ( !strcasecmp ( extension, "css" )) { strncpy ( content_type, "text/css", sizeof ( content_type )); } else if ( !strcasecmp ( extension, "js" )) { strncpy ( content_type, "application/x-javascript", sizeof ( content_type )); } else if ( !strcasecmp ( extension, "jpg" ) || !strcasecmp ( extension, "jpeg" )) { strncpy ( content_type, "image/jpeg", sizeof ( content_type )); } else if ( !strcasecmp ( extension, "gif" ) || !strcasecmp ( extension, "png" ) || !strcasecmp ( extension, "bmp" ) || !strcasecmp ( extension, "tif" ) || !strcasecmp ( extension, "ppm" )) { snprintf ( content_type, sizeof ( content_type ), "image/%s", extension ); } else { strncpy ( content_type, "text/plain", sizeof ( content_type )); } if ( !( http_response = (char*) alloca ( st.st_size + 2 ))) { pthread_exit ((void*) 0); return (void*) 0; } memset ( http_response, 0, st.st_size + 2 ); fread ( http_response, st.st_size, 1, fp ); fclose ( fp ); ltime = time ( NULL ); strtime = strdup ( ctime ( <ime )); strtime [ strlen(strtime) - 1 ] = 0; snprintf ( http_headers, max_headers_length, HTTP_RESPONSE_HEADERS_FORMAT, http_ver, 200, "Found", strtime, config->webserv_banner, content_type, strlen ( http_response )); free ( strtime ); free ( line ); line = NULL; continue; } else if ( nlines == 0 ) { snprintf ( http_response, max_content_length, HTTP_ERR_RESPONSE_FORMAT, 405, "Method Not Allowed", "Method Not Allowed", "The requested HTTP method is not allowed", config->webserv_banner ); ltime = time ( NULL ); strtime = strdup ( ctime ( <ime )); strtime [ strlen(strtime) - 1 ] = 0; snprintf ( http_headers, max_headers_length, HTTP_RESPONSE_HEADERS_FORMAT, "HTTP/1.1", 405, "Method Not Allowed", strtime, "text/html", config->webserv_banner, strlen ( http_response )); free ( strtime ); free ( line ); line = NULL; continue; } free ( line ); line = NULL; } fprintf ( sock, "%s%s", http_headers, http_response ); fclose ( sock ); close ( *sd ); pthread_exit ( 0 ); } /* ----- end of function __AI_webservlet_thread ----- */ /** * \brief Thread running the code of the web server for the web interface of the module */ void* AI_webserv_thread ( void *arg ) { int on = 1, sd, client_sd; struct sockaddr_in addr; pthread_t servlet_thread; pthread_attr_t attr; if (( sd = socket ( AF_INET, SOCK_STREAM, 0 )) < 0 ) { AI_fatal_err ( "Error while creating webserver socket", __FILE__, __LINE__ ); } if ( setsockopt ( sd, SOL_SOCKET, SO_REUSEADDR, (void*) &on, sizeof ( on )) < 0 ) { AI_fatal_err ( "Error while setting SO_REUSEADDR on the socket", __FILE__, __LINE__ ); } memset ( &addr, 0, sizeof ( struct sockaddr_in )); addr.sin_family = AF_INET; addr.sin_port = htons ( config->webserv_port ); addr.sin_addr.s_addr = INADDR_ANY; if ( bind ( sd, (struct sockaddr*) &addr, sizeof ( addr )) < 0 ) { AI_fatal_err ( "Error while binding socket", __FILE__, __LINE__ ); } if ( listen ( sd, 10 ) < 0 ) { AI_fatal_err ( "Error while setting the socket in listen mode", __FILE__, __LINE__ ); } pthread_attr_init ( &attr ); pthread_attr_setdetachstate ( &attr, PTHREAD_CREATE_DETACHED ); while ( 1 ) { if (( client_sd = accept ( sd, NULL, NULL )) < 0 ) continue; if ( pthread_create ( &servlet_thread, &attr, __AI_webservlet_thread, (void*) &client_sd ) != 0 ) { AI_fatal_err ( "Error while creating the webservlet thread", __FILE__, __LINE__ ); } } close ( sd ); pthread_exit ((void*) 0); return (void*) 0; } /* ----- end of function AI_webserv_thread ----- */ /** @} */