2 * libwebsockets - small server side websockets and web server implementation
4 * Copyright (C) 2010-2013 Andy Green <andy@warmcat.com>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation:
9 * version 2.1 of the License.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
22 #include "private-libwebsockets.h"
25 * -04 of the protocol (actually the 80th version) has a radically different
26 * handshake. The 04 spec gives the following idea
28 * The handshake from the client looks as follows:
31 * Host: server.example.com
34 * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
35 * Sec-WebSocket-Origin: http://example.com
36 * Sec-WebSocket-Protocol: chat, superchat
37 * Sec-WebSocket-Version: 4
39 * The handshake from the server looks as follows:
41 * HTTP/1.1 101 Switching Protocols
44 * Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
45 * Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
46 * Sec-WebSocket-Protocol: chat
50 * We have to take care about parsing because the headers may be split
51 * into multiple fragments. They may contain unknown headers with arbitrary
52 * argument lengths. So, we parse using a single-character at a time state
53 * machine that is completely independent of packet size.
57 extern int handshake_0405(struct libwebsocket_context *context, struct libwebsocket *wsi);
61 libwebsocket_read(struct libwebsocket_context *context,
62 struct libwebsocket *wsi, unsigned char * buf, size_t len)
67 case WSI_STATE_HTTP_ISSUING_FILE:
69 wsi->state = WSI_STATE_HTTP_HEADERS;
70 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
71 wsi->u.hdr.lextable_pos = 0;
73 case WSI_STATE_HTTP_HEADERS:
75 lwsl_parser("issuing %d bytes to parser\n", (int)len);
77 //fwrite(buf, 1, len, stderr);
82 // lwsl_info("mode=%d\n", wsi->mode);
85 case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
86 case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
87 case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
88 case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
89 case LWS_CONNMODE_WS_CLIENT:
90 for (n = 0; n < len; n++)
91 if (libwebsocket_client_rx_sm(wsi, *buf++)) {
92 lwsl_info("libwebsocket_client_rx_sm failed\n");
100 #ifndef LWS_NO_SERVER
101 /* LWS_CONNMODE_WS_SERVING */
103 for (n = 0; n < len; n++)
104 if (libwebsocket_parse(wsi, *buf++)) {
105 lwsl_info("libwebsocket_parse failed\n");
109 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
112 lwsl_parser("libwebsocket_parse sees parsing complete\n");
114 /* is this websocket protocol or normal http 1.0? */
116 if (!wsi->u.hdr.hdrs[WSI_TOKEN_UPGRADE].token_len ||
117 !wsi->u.hdr.hdrs[WSI_TOKEN_CONNECTION].token_len) {
118 wsi->state = WSI_STATE_HTTP;
119 if (wsi->protocol->callback)
120 if (wsi->protocol->callback(context, wsi,
123 wsi->u.hdr.hdrs[WSI_TOKEN_GET_URI].token,
124 wsi->u.hdr.hdrs[WSI_TOKEN_GET_URI].token_len)) {
125 lwsl_info("LWS_CALLBACK_HTTP wanted to close\n");
132 lwsl_err("NULL protocol at libwebsocket_read\n");
137 * Make sure user side is happy about protocol
140 while (wsi->protocol->callback) {
142 if (wsi->u.hdr.hdrs[WSI_TOKEN_PROTOCOL].token == NULL) {
143 if (wsi->protocol->name == NULL)
146 if (wsi->protocol->name && strcmp(
147 wsi->u.hdr.hdrs[WSI_TOKEN_PROTOCOL].token,
148 wsi->protocol->name) == 0)
154 /* we didn't find a protocol he wanted? */
156 if (wsi->protocol->callback == NULL) {
157 if (wsi->u.hdr.hdrs[WSI_TOKEN_PROTOCOL].token == NULL) {
158 lwsl_info("[no protocol] "
159 "mapped to protocol 0 handler\n");
160 wsi->protocol = &context->protocols[0];
162 lwsl_err("Requested protocol %s "
164 wsi->u.hdr.hdrs[WSI_TOKEN_PROTOCOL].token);
170 * Give the user code a chance to study the request and
171 * have the opportunity to deny it
174 if ((wsi->protocol->callback)(wsi->protocol->owning_server, wsi,
175 LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
176 &wsi->u.hdr.hdrs[0], NULL, 0)) {
177 lwsl_warn("User code denied connection\n");
183 * Perform the handshake according to the protocol version the
187 switch (wsi->ietf_spec_revision) {
189 lwsl_parser("libwebsocket_parse calling handshake_04\n");
190 if (handshake_0405(context, wsi)) {
191 lwsl_info("handshake_0405 xor 05 has failed the connection\n");
197 lwsl_warn("Unknown client spec version %d\n",
198 wsi->ietf_spec_revision);
202 /* drop the header info */
204 /* free up his parsing allocations... these are gone... */
206 for (n = 0; n < WSI_TOKEN_COUNT; n++)
207 if (wsi->u.hdr.hdrs[n].token)
208 free(wsi->u.hdr.hdrs[n].token);
210 wsi->mode = LWS_CONNMODE_WS_SERVING;
212 /* union transition */
213 memset(&wsi->u, 0, sizeof wsi->u);
216 * create the frame buffer for this connection according to the
217 * size mentioned in the protocol definition. If 0 there, use
218 * a big default for compatibility
221 n = wsi->protocol->rx_buffer_size;
223 n = LWS_MAX_SOCKET_IO_BUF;
224 n += LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING;
225 wsi->u.ws.rx_user_buffer = malloc(n);
226 if (!wsi->u.ws.rx_user_buffer) {
227 lwsl_err("Out of Mem allocating rx buffer %d\n", n);
230 lwsl_info("Allocating RX buffer %d\n", n);
232 lwsl_parser("accepted v%02d connection\n",
233 wsi->ietf_spec_revision);
237 case WSI_STATE_AWAITING_CLOSE_ACK:
238 case WSI_STATE_ESTABLISHED:
239 #ifndef LWS_NO_CLIENT
241 case LWS_CONNMODE_WS_CLIENT:
242 for (n = 0; n < len; n++)
243 if (libwebsocket_client_rx_sm(wsi, *buf++) < 0) {
244 lwsl_info("client rx has bailed\n");
253 #ifndef LWS_NO_SERVER
254 /* LWS_CONNMODE_WS_SERVING */
256 if (libwebsocket_interpret_incoming_packet(wsi, buf, len) < 0) {
257 lwsl_info("interpret_incoming_packet has bailed\n");
263 lwsl_err("libwebsocket_read: Unhandled state\n");
270 lwsl_info("closing connection at libwebsocket_read bail:\n");
272 libwebsocket_close_and_free_session(context, wsi,
273 LWS_CLOSE_STATUS_NOSTATUS);