| /* |
| * libwebsockets - small server side websockets and web server implementation |
| * |
| * Copyright (C) 2010 Andy Green <andy@warmcat.com> |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation: |
| * version 2.1 of the License. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
| * MA 02110-1301 USA |
| */ |
| |
| #include "private-libwebsockets.h" |
| |
| const struct lws_tokens lws_tokens[WSI_TOKEN_COUNT] = { |
| { "GET ", 4 }, |
| { "Host:", 5 }, |
| { "Connection:", 11 }, |
| { "Sec-WebSocket-Key1:", 19 }, |
| { "Sec-WebSocket-Key2:", 19 }, |
| { "Sec-WebSocket-Protocol:", 23 }, |
| { "Upgrade:", 8 }, |
| { "Origin:", 7 }, |
| { "Sec-WebSocket-Draft:", 20 }, |
| { "\x0d\x0a", 2 }, |
| }; |
| |
| int libwebsocket_parse(struct libwebsocket *wsi, unsigned char c) |
| { |
| int n; |
| |
| switch (wsi->parser_state) { |
| case WSI_TOKEN_GET_URI: |
| case WSI_TOKEN_HOST: |
| case WSI_TOKEN_CONNECTION: |
| case WSI_TOKEN_KEY1: |
| case WSI_TOKEN_KEY2: |
| case WSI_TOKEN_PROTOCOL: |
| case WSI_TOKEN_UPGRADE: |
| case WSI_TOKEN_ORIGIN: |
| case WSI_TOKEN_DRAFT: |
| case WSI_TOKEN_CHALLENGE: |
| |
| debug("WSI_TOKEN_(%d) '%c'\n", wsi->parser_state, c); |
| |
| /* collect into malloc'd buffers */ |
| /* optional space swallow */ |
| if (!wsi->utf8_token[wsi->parser_state].token_len && c == ' ') |
| break; |
| |
| /* special case space terminator for get-uri */ |
| if (wsi->parser_state == WSI_TOKEN_GET_URI && c == ' ') { |
| wsi->utf8_token[wsi->parser_state].token[ |
| wsi->utf8_token[wsi->parser_state].token_len] = '\0'; |
| wsi->parser_state = WSI_TOKEN_SKIPPING; |
| break; |
| } |
| |
| /* allocate appropriate memory */ |
| if (wsi->utf8_token[wsi->parser_state].token_len == |
| wsi->current_alloc_len - 1) { |
| /* need to extend */ |
| wsi->current_alloc_len += LWS_ADDITIONAL_HDR_ALLOC; |
| if (wsi->current_alloc_len >= LWS_MAX_HEADER_LEN) { |
| /* it's waaay to much payload, fail it */ |
| strcpy(wsi->utf8_token[wsi->parser_state].token, |
| "!!! Length exceeded maximum supported !!!"); |
| wsi->parser_state = WSI_TOKEN_SKIPPING; |
| break; |
| } |
| wsi->utf8_token[wsi->parser_state].token = |
| realloc(wsi->utf8_token[wsi->parser_state].token, |
| wsi->current_alloc_len); |
| } |
| |
| /* bail at EOL */ |
| if (wsi->parser_state != WSI_TOKEN_CHALLENGE && c == '\x0d') { |
| wsi->utf8_token[wsi->parser_state].token[ |
| wsi->utf8_token[wsi->parser_state].token_len] = '\0'; |
| wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR; |
| break; |
| } |
| |
| wsi->utf8_token[wsi->parser_state].token[ |
| wsi->utf8_token[wsi->parser_state].token_len++] = c; |
| |
| /* special payload limiting */ |
| if (wsi->parser_state == WSI_TOKEN_CHALLENGE && |
| wsi->utf8_token[wsi->parser_state].token_len == 8) { |
| debug("Setting WSI_PARSING_COMPLETE\n"); |
| wsi->parser_state = WSI_PARSING_COMPLETE; |
| break; |
| } |
| |
| break; |
| |
| /* collecting and checking a name part */ |
| case WSI_TOKEN_NAME_PART: |
| debug("WSI_TOKEN_NAME_PART '%c'\n", c); |
| |
| if (wsi->name_buffer_pos == sizeof(wsi->name_buffer) - 1) { |
| /* name bigger than we can handle, skip until next */ |
| wsi->parser_state = WSI_TOKEN_SKIPPING; |
| break; |
| } |
| wsi->name_buffer[wsi->name_buffer_pos++] = c; |
| wsi->name_buffer[wsi->name_buffer_pos] = '\0'; |
| |
| for (n = 0; n < WSI_TOKEN_COUNT; n++) { |
| if (wsi->name_buffer_pos != lws_tokens[n].token_len) |
| continue; |
| if (strcmp(lws_tokens[n].token, wsi->name_buffer)) |
| continue; |
| debug("known hdr '%s'\n", wsi->name_buffer); |
| wsi->parser_state = WSI_TOKEN_GET_URI + n; |
| wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC; |
| wsi->utf8_token[wsi->parser_state].token = |
| malloc(wsi->current_alloc_len); |
| wsi->utf8_token[wsi->parser_state].token_len = 0; |
| n = WSI_TOKEN_COUNT; |
| } |
| |
| /* colon delimiter means we just don't know this name */ |
| |
| if (wsi->parser_state == WSI_TOKEN_NAME_PART && c == ':') { |
| debug("skipping unknown header '%s'\n", |
| wsi->name_buffer); |
| wsi->parser_state = WSI_TOKEN_SKIPPING; |
| break; |
| } |
| |
| /* don't look for payload when it can just be http headers */ |
| |
| if (wsi->parser_state == WSI_TOKEN_CHALLENGE && |
| !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len) { |
| /* they're HTTP headers, not websocket upgrade! */ |
| debug("Setting WSI_PARSING_COMPLETE " |
| "from http headers\n"); |
| wsi->parser_state = WSI_PARSING_COMPLETE; |
| } |
| break; |
| |
| /* skipping arg part of a name we didn't recognize */ |
| case WSI_TOKEN_SKIPPING: |
| debug("WSI_TOKEN_SKIPPING '%c'\n", c); |
| if (c == '\x0d') |
| wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR; |
| break; |
| case WSI_TOKEN_SKIPPING_SAW_CR: |
| debug("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c); |
| if (c == '\x0a') |
| wsi->parser_state = WSI_TOKEN_NAME_PART; |
| else |
| wsi->parser_state = WSI_TOKEN_SKIPPING; |
| wsi->name_buffer_pos = 0; |
| break; |
| /* we're done, ignore anything else */ |
| case WSI_PARSING_COMPLETE: |
| debug("WSI_PARSING_COMPLETE '%c'\n", c); |
| break; |
| |
| default: /* keep gcc happy */ |
| break; |
| } |
| |
| return 0; |
| } |
| |
| |
| static int libwebsocket_rx_sm(struct libwebsocket *wsi, unsigned char c) |
| { |
| int n; |
| unsigned char buf[2]; |
| |
| switch (wsi->lws_rx_parse_state) { |
| case LWS_RXPS_NEW: |
| |
| switch (wsi->ietf_spec_revision) { |
| /* Firefox 4.0b6 likes this as of 30 Oct */ |
| case 76: |
| if (c == 0xff) |
| wsi->lws_rx_parse_state = LWS_RXPS_SEEN_76_FF; |
| break; |
| case 0: |
| break; |
| } |
| |
| if (c == 0) { |
| wsi->lws_rx_parse_state = LWS_RXPS_EAT_UNTIL_76_FF; |
| wsi->rx_user_buffer_head = 0; |
| } |
| break; |
| case LWS_RXPS_EAT_UNTIL_76_FF: |
| if (c == 0xff) { |
| wsi->lws_rx_parse_state = LWS_RXPS_NEW; |
| goto issue; |
| } |
| wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING + |
| (wsi->rx_user_buffer_head++)] = c; |
| |
| if (wsi->rx_user_buffer_head != MAX_USER_RX_BUFFER) |
| break; |
| issue: |
| if (wsi->callback) |
| wsi->callback(wsi, LWS_CALLBACK_RECEIVE, |
| &wsi->user_space[0], |
| &wsi->rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING], |
| wsi->rx_user_buffer_head); |
| wsi->rx_user_buffer_head = 0; |
| break; |
| case LWS_RXPS_SEEN_76_FF: |
| if (c) |
| break; |
| |
| debug("Seen that client is requesting " |
| "a v76 close, sending ack\n"); |
| buf[0] = 0xff; |
| buf[1] = 0; |
| n = libwebsocket_write(wsi, buf, 2, LWS_WRITE_HTTP); |
| if (n < 0) { |
| fprintf(stderr, "ERROR writing to socket"); |
| return -1; |
| } |
| debug(" v76 close ack sent, server closing skt\n"); |
| /* returning < 0 will get it closed in parent */ |
| return -1; |
| |
| case LWS_RXPS_PULLING_76_LENGTH: |
| break; |
| case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED: |
| break; |
| } |
| |
| return 0; |
| } |
| |
| int libwebsocket_interpret_incoming_packet(struct libwebsocket *wsi, |
| unsigned char *buf, size_t len) |
| { |
| int n; |
| |
| fprintf(stderr, "received %d byte packet\n", (int)len); |
| for (n = 0; n < len; n++) |
| fprintf(stderr, "%02X ", buf[n]); |
| fprintf(stderr, "\n"); |
| |
| /* let the rx protocol state machine have as much as it needs */ |
| |
| n = 0; |
| while (wsi->lws_rx_parse_state != |
| LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED && n < len) |
| if (libwebsocket_rx_sm(wsi, buf[n++]) < 0) |
| return -1; |
| |
| return -0; |
| } |
| |
| |
| |
| /** |
| * libwebsocket_write() - Apply protocol then write data to client |
| * @wsi: Websocket instance (available from user callback) |
| * @buf: The data to send. For data being sent on a websocket |
| * connection (ie, not default http), this buffer MUST have |
| * LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer |
| * and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid |
| * in the buffer after (buf + len). This is so the protocol |
| * header and trailer data can be added in-situ. |
| * @len: Count of the data bytes in the payload starting from buf |
| * @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one |
| * of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate |
| * data on a websockets connection. Remember to allow the extra |
| * bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT |
| * are used. |
| * |
| * This function provides the way to issue data back to the client |
| * for both http and websocket protocols. |
| * |
| * In the case of sending using websocket protocol, be sure to allocate |
| * valid storage before and after buf as explained above. This scheme |
| * allows maximum efficiency of sending data and protocol in a single |
| * packet while not burdening the user code with any protocol knowledge. |
| */ |
| |
| int libwebsocket_write(struct libwebsocket * wsi, unsigned char *buf, |
| size_t len, enum libwebsocket_write_protocol protocol) |
| { |
| int n; |
| int pre = 0; |
| int post = 0; |
| unsigned int shift = 7; |
| |
| if (protocol == LWS_WRITE_HTTP) |
| goto send_raw; |
| |
| /* websocket protocol, either binary or text */ |
| |
| if (wsi->state != WSI_STATE_ESTABLISHED) |
| return -1; |
| |
| switch (wsi->ietf_spec_revision) { |
| /* chrome likes this as of 30 Oct */ |
| /* Firefox 4.0b6 likes this as of 30 Oct */ |
| case 76: |
| if (protocol == LWS_WRITE_BINARY) { |
| /* in binary mode we send 7-bit used length blocks */ |
| pre = 1; |
| while (len & (127 << shift)) { |
| pre++; |
| shift += 7; |
| } |
| n = 0; |
| shift -= 7; |
| while (shift >= 0) { |
| if (shift) |
| buf[0 - pre + n] = |
| ((len >> shift) & 127) | 0x80; |
| else |
| buf[0 - pre + n] = |
| ((len >> shift) & 127); |
| n++; |
| shift -= 7; |
| } |
| break; |
| } |
| |
| /* frame type = text, length-free spam mode */ |
| |
| buf[-1] = 0; |
| buf[len] = 0xff; /* EOT marker */ |
| pre = 1; |
| post = 1; |
| break; |
| |
| case 0: |
| buf[-9] = 0xff; |
| #if defined __LP64__ |
| buf[-8] = len >> 56; |
| buf[-7] = len >> 48; |
| buf[-6] = len >> 40; |
| buf[-5] = len >> 32; |
| #else |
| buf[-8] = 0; |
| buf[-7] = 0; |
| buf[-6] = 0; |
| buf[-5] = 0; |
| #endif |
| buf[-4] = len >> 24; |
| buf[-3] = len >> 16; |
| buf[-2] = len >> 8; |
| buf[-1] = len; |
| pre = 9; |
| break; |
| |
| /* just an unimplemented spec right now apparently */ |
| case 2: |
| n = 4; /* text */ |
| if (protocol == LWS_WRITE_BINARY) |
| n = 5; /* binary */ |
| if (len < 126) { |
| buf[-2] = n; |
| buf[-1] = len; |
| pre = 2; |
| } else { |
| if (len < 65536) { |
| buf[-4] = n; |
| buf[-3] = 126; |
| buf[-2] = len >> 8; |
| buf[-1] = len; |
| pre = 4; |
| } else { |
| buf[-10] = n; |
| buf[-9] = 127; |
| #if defined __LP64__ |
| buf[-8] = (len >> 56) & 0x7f; |
| buf[-7] = len >> 48; |
| buf[-6] = len >> 40; |
| buf[-5] = len >> 32; |
| #else |
| buf[-8] = 0; |
| buf[-7] = 0; |
| buf[-6] = 0; |
| buf[-5] = 0; |
| #endif |
| buf[-4] = len >> 24; |
| buf[-3] = len >> 16; |
| buf[-2] = len >> 8; |
| buf[-1] = len; |
| pre = 10; |
| } |
| } |
| break; |
| } |
| |
| #if 0 |
| for (n = 0; n < (len + pre + post); n++) |
| fprintf(stderr, "%02X ", buf[n - pre]); |
| |
| fprintf(stderr, "\n"); |
| #endif |
| |
| send_raw: |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (use_ssl) { |
| n = SSL_write(wsi->ssl, buf - pre, len + pre + post); |
| if (n < 0) { |
| fprintf(stderr, "ERROR writing to socket"); |
| return -1; |
| } |
| } else { |
| #endif |
| n = send(wsi->sock, buf - pre, len + pre + post, 0); |
| if (n < 0) { |
| fprintf(stderr, "ERROR writing to socket"); |
| return -1; |
| } |
| #ifdef LWS_OPENSSL_SUPPORT |
| } |
| #endif |
| // fprintf(stderr, "written %d bytes to client\n", (int)len); |
| |
| return 0; |
| } |
| |
| |
| /** |
| * libwebsockets_serve_http_file() - Send a file back to the client using http |
| * @wsi: Websocket instance (available from user callback) |
| * @file: The file to issue over http |
| * @content_type: The http content type, eg, text/html |
| * |
| * This function is intended to be called from the callback in response |
| * to http requests from the client. It allows the callback to issue |
| * local files down the http link in a single step. |
| */ |
| |
| int libwebsockets_serve_http_file(struct libwebsocket *wsi, const char * file, |
| const char * content_type) |
| { |
| int fd; |
| struct stat stat; |
| char buf[512]; |
| char *p = buf; |
| int n; |
| |
| fd = open(file, O_RDONLY); |
| if (fd < 1) { |
| p += sprintf(p, "HTTP/1.0 400 Bad\x0d\x0a" |
| "Server: libwebsockets\x0d\x0a" |
| "\x0d\x0a" |
| ); |
| libwebsocket_write(wsi, (unsigned char *)buf, p - buf, |
| LWS_WRITE_HTTP); |
| |
| return -1; |
| } |
| |
| fstat(fd, &stat); |
| p += sprintf(p, "HTTP/1.0 200 OK\x0d\x0a" |
| "Server: libwebsockets\x0d\x0a" |
| "Content-Type: %s\x0d\x0a" |
| "Content-Length: %u\x0d\x0a" |
| "\x0d\x0a", content_type, (unsigned int)stat.st_size); |
| |
| libwebsocket_write(wsi, (unsigned char *)buf, p - buf, LWS_WRITE_HTTP); |
| |
| n = 1; |
| while (n > 0) { |
| n = read(fd, buf, 512); |
| libwebsocket_write(wsi, (unsigned char *)buf, n, |
| LWS_WRITE_HTTP); |
| } |
| |
| close(fd); |
| |
| return 0; |
| } |