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)
61 struct allocated_headers *ah;
66 case WSI_STATE_HTTP_ISSUING_FILE:
68 wsi->state = WSI_STATE_HTTP_HEADERS;
69 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
70 wsi->u.hdr.lextable_pos = 0;
72 case WSI_STATE_HTTP_HEADERS:
74 lwsl_parser("issuing %d bytes to parser\n", (int)len);
78 case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
79 case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
80 case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
81 case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
82 case LWS_CONNMODE_WS_CLIENT:
83 for (n = 0; n < len; n++)
84 if (libwebsocket_client_rx_sm(wsi, *buf++)) {
85 lwsl_info("client_rx_sm failed\n");
94 /* LWS_CONNMODE_WS_SERVING */
96 for (n = 0; n < len; n++)
97 if (libwebsocket_parse(wsi, *buf++)) {
98 lwsl_info("libwebsocket_parse failed\n");
102 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
105 lwsl_parser("libwebsocket_parse sees parsing complete\n");
107 wsi->mode = LWS_CONNMODE_PRE_WS_SERVING_ACCEPT;
109 /* is this websocket protocol or normal http 1.0? */
111 if (!lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE) ||
112 !lws_hdr_total_length(wsi, WSI_TOKEN_CONNECTION)) {
114 /* it's not websocket.... shall we accept it as http? */
116 if (!lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI)) {
117 lwsl_warn("Missing URI in HTTP request\n");
121 lwsl_info("HTTP request for '%s'\n",
122 lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI));
124 if (libwebsocket_ensure_user_space(wsi))
128 * Hm we still need the headers so the
129 * callback can look at leaders like the URI, but we
130 * need to transition to http union state.... hold a
131 * copy of u.hdr.ah and deallocate afterwards
135 uri_ptr = lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI);
136 uri_len = lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI);
138 /* union transition */
139 memset(&wsi->u, 0, sizeof(wsi->u));
140 wsi->mode = LWS_CONNMODE_HTTP_SERVING_ACCEPTED;
141 wsi->state = WSI_STATE_HTTP;
143 /* expose it at the same offset as u.hdr */
147 if (wsi->protocol->callback)
148 n = wsi->protocol->callback(context, wsi,
150 wsi->user_space, uri_ptr, uri_len);
152 /* now drop the header info we kept a pointer to */
155 /* not possible to continue to use past here */
156 wsi->u.http.ah = NULL;
159 lwsl_info("LWS_CALLBACK_HTTP closing\n");
160 goto bail; /* struct ah ptr already nuked */
167 lwsl_err("NULL protocol at libwebsocket_read\n");
172 * Make sure user side is happy about protocol
175 while (wsi->protocol->callback) {
177 if (!lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL)) {
178 if (wsi->protocol->name == NULL)
181 if (wsi->protocol->name && strcmp(
182 lws_hdr_simple_ptr(wsi,
184 wsi->protocol->name) == 0)
190 /* we didn't find a protocol he wanted? */
192 if (wsi->protocol->callback == NULL) {
193 if (lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL) ==
195 lwsl_info("no protocol -> prot 0 handler\n");
196 wsi->protocol = &context->protocols[0];
198 lwsl_err("Req protocol %s not supported\n",
199 lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL));
204 /* allocate wsi->user storage */
205 if (libwebsocket_ensure_user_space(wsi))
209 * Give the user code a chance to study the request and
210 * have the opportunity to deny it
213 if ((wsi->protocol->callback)(wsi->protocol->owning_server, wsi,
214 LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
216 lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL), 0)) {
217 lwsl_warn("User code denied connection\n");
223 * Perform the handshake according to the protocol version the
227 switch (wsi->ietf_spec_revision) {
229 lwsl_parser("lws_parse calling handshake_04\n");
230 if (handshake_0405(context, wsi)) {
231 lwsl_info("hs0405 has failed the connection\n");
237 lwsl_warn("Unknown client spec version %d\n",
238 wsi->ietf_spec_revision);
242 /* drop the header info -- no bail_nuke_ah after this */
247 wsi->mode = LWS_CONNMODE_WS_SERVING;
249 /* union transition */
250 memset(&wsi->u, 0, sizeof(wsi->u));
251 wsi->u.ws.rxflow_change_to = LWS_RXFLOW_ALLOW;
254 * create the frame buffer for this connection according to the
255 * size mentioned in the protocol definition. If 0 there, use
256 * a big default for compatibility
259 n = wsi->protocol->rx_buffer_size;
261 n = LWS_MAX_SOCKET_IO_BUF;
262 n += LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING;
263 wsi->u.ws.rx_user_buffer = malloc(n);
264 if (!wsi->u.ws.rx_user_buffer) {
265 lwsl_err("Out of Mem allocating rx buffer %d\n", n);
268 lwsl_info("Allocating RX buffer %d\n", n);
270 if (setsockopt(wsi->sock, SOL_SOCKET, SO_SNDBUF, &n, sizeof n)) {
271 lwsl_warn("Failed to set SNDBUF to %d", n);
275 lwsl_parser("accepted v%02d connection\n",
276 wsi->ietf_spec_revision);
280 case WSI_STATE_AWAITING_CLOSE_ACK:
281 case WSI_STATE_ESTABLISHED:
282 #ifndef LWS_NO_CLIENT
284 case LWS_CONNMODE_WS_CLIENT:
285 for (n = 0; n < len; n++)
286 if (libwebsocket_client_rx_sm(
288 lwsl_info("client rx has bailed\n");
297 #ifndef LWS_NO_SERVER
298 /* LWS_CONNMODE_WS_SERVING */
300 if (libwebsocket_interpret_incoming_packet(wsi, buf, len) < 0) {
301 lwsl_info("interpret_incoming_packet has bailed\n");
307 lwsl_err("libwebsocket_read: Unhandled state\n");
314 /* drop the header info */
319 lwsl_info("closing connection at libwebsocket_read bail:\n");
321 libwebsocket_close_and_free_session(context, wsi,
322 LWS_CLOSE_STATUS_NOSTATUS);