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 libwebsocket_read(struct libwebsocket_context *context,
58 struct libwebsocket *wsi, unsigned char *buf, size_t len)
63 case WSI_STATE_HTTP_ISSUING_FILE:
65 wsi->state = WSI_STATE_HTTP_HEADERS;
66 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
67 wsi->u.hdr.lextable_pos = 0;
69 case WSI_STATE_HTTP_HEADERS:
71 lwsl_parser("issuing %d bytes to parser\n", (int)len);
75 case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
76 case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
77 case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
78 case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
79 case LWS_CONNMODE_WS_CLIENT:
80 for (n = 0; n < len; n++)
81 if (libwebsocket_client_rx_sm(wsi, *buf++)) {
82 lwsl_info("client_rx_sm failed\n");
91 /* LWS_CONNMODE_WS_SERVING */
93 for (n = 0; n < len; n++)
94 if (libwebsocket_parse(wsi, *buf++)) {
95 lwsl_info("libwebsocket_parse failed\n");
99 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
102 lwsl_parser("libwebsocket_parse sees parsing complete\n");
104 /* is this websocket protocol or normal http 1.0? */
106 if (!lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE) ||
107 !lws_hdr_total_length(wsi, WSI_TOKEN_CONNECTION)) {
108 wsi->state = WSI_STATE_HTTP;
110 if (wsi->protocol->callback)
111 n = wsi->protocol->callback(context, wsi,
114 lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI),
115 lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI));
117 /* drop the header info */
122 lwsl_info("LWS_CALLBACK_HTTP closing\n");
130 lwsl_err("NULL protocol at libwebsocket_read\n");
135 * Make sure user side is happy about protocol
138 while (wsi->protocol->callback) {
140 if (!lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL)) {
141 if (wsi->protocol->name == NULL)
144 if (wsi->protocol->name && strcmp(
145 lws_hdr_simple_ptr(wsi,
147 wsi->protocol->name) == 0)
153 /* we didn't find a protocol he wanted? */
155 if (wsi->protocol->callback == NULL) {
156 if (lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL) ==
158 lwsl_info("no protocol -> prot 0 handler\n");
159 wsi->protocol = &context->protocols[0];
161 lwsl_err("Req protocol %s not supported\n",
162 lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL));
168 * Give the user code a chance to study the request and
169 * have the opportunity to deny it
172 if ((wsi->protocol->callback)(wsi->protocol->owning_server, wsi,
173 LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
174 lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL),
176 lwsl_warn("User code denied connection\n");
182 * Perform the handshake according to the protocol version the
186 switch (wsi->ietf_spec_revision) {
188 lwsl_parser("lws_parse calling handshake_04\n");
189 if (handshake_0405(context, wsi)) {
190 lwsl_info("hs0405 has failed the connection\n");
196 lwsl_warn("Unknown client spec version %d\n",
197 wsi->ietf_spec_revision);
201 /* drop the header info */
206 wsi->mode = LWS_CONNMODE_WS_SERVING;
208 /* union transition */
209 memset(&wsi->u, 0, sizeof(wsi->u));
212 * create the frame buffer for this connection according to the
213 * size mentioned in the protocol definition. If 0 there, use
214 * a big default for compatibility
217 n = wsi->protocol->rx_buffer_size;
219 n = LWS_MAX_SOCKET_IO_BUF;
220 n += LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING;
221 wsi->u.ws.rx_user_buffer = malloc(n);
222 if (!wsi->u.ws.rx_user_buffer) {
223 lwsl_err("Out of Mem allocating rx buffer %d\n", n);
226 lwsl_info("Allocating RX buffer %d\n", n);
228 lwsl_parser("accepted v%02d connection\n",
229 wsi->ietf_spec_revision);
233 case WSI_STATE_AWAITING_CLOSE_ACK:
234 case WSI_STATE_ESTABLISHED:
235 #ifndef LWS_NO_CLIENT
237 case LWS_CONNMODE_WS_CLIENT:
238 for (n = 0; n < len; n++)
239 if (libwebsocket_client_rx_sm(
241 lwsl_info("client rx has bailed\n");
250 #ifndef LWS_NO_SERVER
251 /* LWS_CONNMODE_WS_SERVING */
253 if (libwebsocket_interpret_incoming_packet(wsi, buf, len) < 0) {
254 lwsl_info("interpret_incoming_packet has bailed\n");
260 lwsl_err("libwebsocket_read: Unhandled state\n");
267 lwsl_info("closing connection at libwebsocket_read bail:\n");
269 libwebsocket_close_and_free_session(context, wsi,
270 LWS_CLOSE_STATUS_NOSTATUS);