| /* |
| * libwebsockets - small server side websockets and web server implementation |
| * |
| * Copyright (C) 2010-2013 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" |
| |
| /* |
| * -04 of the protocol (actually the 80th version) has a radically different |
| * handshake. The 04 spec gives the following idea |
| * |
| * The handshake from the client looks as follows: |
| * |
| * GET /chat HTTP/1.1 |
| * Host: server.example.com |
| * Upgrade: websocket |
| * Connection: Upgrade |
| * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ== |
| * Sec-WebSocket-Origin: http://example.com |
| * Sec-WebSocket-Protocol: chat, superchat |
| * Sec-WebSocket-Version: 4 |
| * |
| * The handshake from the server looks as follows: |
| * |
| * HTTP/1.1 101 Switching Protocols |
| * Upgrade: websocket |
| * Connection: Upgrade |
| * Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo= |
| * Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC== |
| * Sec-WebSocket-Protocol: chat |
| */ |
| |
| /* |
| * We have to take care about parsing because the headers may be split |
| * into multiple fragments. They may contain unknown headers with arbitrary |
| * argument lengths. So, we parse using a single-character at a time state |
| * machine that is completely independent of packet size. |
| */ |
| |
| int |
| libwebsocket_read(struct libwebsocket_context *context, |
| struct libwebsocket *wsi, unsigned char *buf, size_t len) |
| { |
| size_t n; |
| struct allocated_headers *ah; |
| char *uri_ptr; |
| int uri_len; |
| |
| switch (wsi->state) { |
| case WSI_STATE_HTTP_ISSUING_FILE: |
| case WSI_STATE_HTTP: |
| wsi->state = WSI_STATE_HTTP_HEADERS; |
| wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART; |
| wsi->u.hdr.lextable_pos = 0; |
| /* fallthru */ |
| case WSI_STATE_HTTP_HEADERS: |
| |
| lwsl_parser("issuing %d bytes to parser\n", (int)len); |
| |
| #ifndef LWS_NO_CLIENT |
| switch (wsi->mode) { |
| case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY: |
| case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE: |
| case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY: |
| case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT: |
| case LWS_CONNMODE_WS_CLIENT: |
| for (n = 0; n < len; n++) |
| if (libwebsocket_client_rx_sm(wsi, *buf++)) { |
| lwsl_info("client_rx_sm failed\n"); |
| goto bail; |
| } |
| return 0; |
| default: |
| break; |
| } |
| #endif |
| #ifndef LWS_NO_SERVER |
| /* LWS_CONNMODE_WS_SERVING */ |
| |
| for (n = 0; n < len; n++) |
| if (libwebsocket_parse(wsi, *buf++)) { |
| lwsl_info("libwebsocket_parse failed\n"); |
| goto bail; |
| } |
| |
| if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE) |
| break; |
| |
| lwsl_parser("libwebsocket_parse sees parsing complete\n"); |
| |
| /* is this websocket protocol or normal http 1.0? */ |
| |
| if (!lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE) || |
| !lws_hdr_total_length(wsi, WSI_TOKEN_CONNECTION)) { |
| |
| /* it's not websocket.... shall we accept it as http? */ |
| |
| if (!lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI)) { |
| lwsl_warn("Missing URI in HTTP request\n"); |
| /* drop the header info */ |
| if (wsi->u.hdr.ah) |
| free(wsi->u.hdr.ah); |
| goto bail; |
| } |
| |
| lwsl_info("HTTP request for '%s'\n", |
| lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI)); |
| |
| if (libwebsocket_ensure_user_space(wsi)) { |
| /* drop the header info */ |
| if (wsi->u.hdr.ah) |
| free(wsi->u.hdr.ah); |
| goto bail; |
| } |
| |
| /* |
| * Hm we still need the headers so the |
| * callback can look at leaders like the URI, but we |
| * need to transition to http union state.... hold a |
| * copy of u.hdr.ah and deallocate afterwards |
| */ |
| |
| ah = wsi->u.hdr.ah; |
| uri_ptr = lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI); |
| uri_len = lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI); |
| |
| /* union transition */ |
| memset(&wsi->u, 0, sizeof(wsi->u)); |
| |
| wsi->state = WSI_STATE_HTTP; |
| n = 0; |
| if (wsi->protocol->callback) |
| n = wsi->protocol->callback(context, wsi, |
| LWS_CALLBACK_HTTP, |
| wsi->user_space, uri_ptr, uri_len); |
| |
| /* now drop the header info we kept a pointer to */ |
| if (ah) |
| free(ah); |
| |
| if (n) { |
| lwsl_info("LWS_CALLBACK_HTTP closing\n"); |
| goto bail; |
| } |
| |
| return 0; |
| } |
| |
| if (!wsi->protocol) |
| lwsl_err("NULL protocol at libwebsocket_read\n"); |
| |
| /* |
| * It's websocket |
| * |
| * Make sure user side is happy about protocol |
| */ |
| |
| while (wsi->protocol->callback) { |
| |
| if (!lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL)) { |
| if (wsi->protocol->name == NULL) |
| break; |
| } else |
| if (wsi->protocol->name && strcmp( |
| lws_hdr_simple_ptr(wsi, |
| WSI_TOKEN_PROTOCOL), |
| wsi->protocol->name) == 0) |
| break; |
| |
| wsi->protocol++; |
| } |
| |
| /* we didn't find a protocol he wanted? */ |
| |
| if (wsi->protocol->callback == NULL) { |
| if (lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL) == |
| NULL) { |
| lwsl_info("no protocol -> prot 0 handler\n"); |
| wsi->protocol = &context->protocols[0]; |
| } else { |
| lwsl_err("Req protocol %s not supported\n", |
| lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL)); |
| goto bail; |
| } |
| } |
| |
| /* |
| * Give the user code a chance to study the request and |
| * have the opportunity to deny it |
| */ |
| |
| if ((wsi->protocol->callback)(wsi->protocol->owning_server, wsi, |
| LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION, |
| lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL), |
| NULL, 0)) { |
| lwsl_warn("User code denied connection\n"); |
| goto bail; |
| } |
| |
| |
| /* |
| * Perform the handshake according to the protocol version the |
| * client announced |
| */ |
| |
| switch (wsi->ietf_spec_revision) { |
| case 13: |
| lwsl_parser("lws_parse calling handshake_04\n"); |
| if (handshake_0405(context, wsi)) { |
| lwsl_info("hs0405 has failed the connection\n"); |
| goto bail; |
| } |
| break; |
| |
| default: |
| lwsl_warn("Unknown client spec version %d\n", |
| wsi->ietf_spec_revision); |
| goto bail; |
| } |
| |
| /* drop the header info */ |
| |
| if (wsi->u.hdr.ah) |
| free(wsi->u.hdr.ah); |
| |
| wsi->mode = LWS_CONNMODE_WS_SERVING; |
| |
| /* union transition */ |
| memset(&wsi->u, 0, sizeof(wsi->u)); |
| |
| /* |
| * create the frame buffer for this connection according to the |
| * size mentioned in the protocol definition. If 0 there, use |
| * a big default for compatibility |
| */ |
| |
| n = wsi->protocol->rx_buffer_size; |
| if (!n) |
| n = LWS_MAX_SOCKET_IO_BUF; |
| n += LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING; |
| wsi->u.ws.rx_user_buffer = malloc(n); |
| if (!wsi->u.ws.rx_user_buffer) { |
| lwsl_err("Out of Mem allocating rx buffer %d\n", n); |
| goto bail; |
| } |
| lwsl_info("Allocating RX buffer %d\n", n); |
| |
| lwsl_parser("accepted v%02d connection\n", |
| wsi->ietf_spec_revision); |
| #endif |
| break; |
| |
| case WSI_STATE_AWAITING_CLOSE_ACK: |
| case WSI_STATE_ESTABLISHED: |
| #ifndef LWS_NO_CLIENT |
| switch (wsi->mode) { |
| case LWS_CONNMODE_WS_CLIENT: |
| for (n = 0; n < len; n++) |
| if (libwebsocket_client_rx_sm( |
| wsi, *buf++) < 0) { |
| lwsl_info("client rx has bailed\n"); |
| goto bail; |
| } |
| |
| return 0; |
| default: |
| break; |
| } |
| #endif |
| #ifndef LWS_NO_SERVER |
| /* LWS_CONNMODE_WS_SERVING */ |
| |
| if (libwebsocket_interpret_incoming_packet(wsi, buf, len) < 0) { |
| lwsl_info("interpret_incoming_packet has bailed\n"); |
| goto bail; |
| } |
| #endif |
| break; |
| default: |
| lwsl_err("libwebsocket_read: Unhandled state\n"); |
| break; |
| } |
| |
| return 0; |
| |
| bail: |
| lwsl_info("closing connection at libwebsocket_read bail:\n"); |
| |
| libwebsocket_close_and_free_session(context, wsi, |
| LWS_CLOSE_STATUS_NOSTATUS); |
| |
| return -1; |
| } |