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 #define min(a, b) ((a) < (b) ? (a) : (b))
53 * We have to take care about parsing because the headers may be split
54 * into multiple fragments. They may contain unknown headers with arbitrary
55 * argument lengths. So, we parse using a single-character at a time state
56 * machine that is completely independent of packet size.
60 libwebsocket_read(struct libwebsocket_context *context,
61 struct libwebsocket *wsi, unsigned char *buf, size_t len)
65 unsigned char *last_char;
68 case WSI_STATE_HTTP2_AWAIT_CLIENT_PREFACE:
69 case WSI_STATE_HTTP2_ESTABLISHED_PRE_SETTINGS:
70 case WSI_STATE_HTTP2_ESTABLISHED:
74 * we were accepting input but now we stopped doing so
76 if (!(wsi->rxflow_change_to & LWS_RXFLOW_ALLOW)) {
77 lws_rxflow_cache(wsi, buf, n, len);
82 /* account for what we're using in rxflow buffer */
83 if (wsi->rxflow_buffer)
85 if (lws_http2_parser(context, wsi, buf[n++]))
91 wsi->hdr_parsing_completed = 0;
93 case WSI_STATE_HTTP_ISSUING_FILE:
94 wsi->state = WSI_STATE_HTTP_HEADERS;
95 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
96 wsi->u.hdr.lextable_pos = 0;
98 case WSI_STATE_HTTP_HEADERS:
99 lwsl_parser("issuing %d bytes to parser\n", (int)len);
101 if (lws_handshake_client(wsi, &buf, len))
105 if (lws_handshake_server(context, wsi, &buf, len))
106 /* Handshake indicates this session is done. */
109 /* It's possible that we've exhausted our data already, but
110 * lws_handshake_server doesn't update len for us. Figure out how
111 * much was read, so that we can proceed appropriately: */
112 len -= (buf - last_char);
114 if (!wsi->hdr_parsing_completed)
115 /* More header content on the way */
118 switch (wsi->state) {
120 case WSI_STATE_HTTP_HEADERS:
122 case WSI_STATE_HTTP_ISSUING_FILE:
124 case WSI_STATE_HTTP_BODY:
125 wsi->u.http.content_remain = wsi->u.http.content_length;
132 case WSI_STATE_HTTP_BODY:
134 while (len && wsi->u.http.content_remain) {
135 /* Copy as much as possible, up to the limit of:
136 * what we have in the read buffer (len)
137 * remaining portion of the POST body (content_remain)
139 body_chunk_len = min(wsi->u.http.content_remain,len);
140 wsi->u.http.content_remain -= body_chunk_len;
141 len -= body_chunk_len;
143 if (wsi->protocol->callback) {
144 n = wsi->protocol->callback(
145 wsi->protocol->owning_server, wsi,
146 LWS_CALLBACK_HTTP_BODY, wsi->user_space,
147 buf, body_chunk_len);
151 buf += body_chunk_len;
153 if (!wsi->u.http.content_remain) {
154 /* he sent the content in time */
155 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
156 if (wsi->protocol->callback) {
157 n = wsi->protocol->callback(
158 wsi->protocol->owning_server, wsi,
159 LWS_CALLBACK_HTTP_BODY_COMPLETION,
160 wsi->user_space, NULL, 0);
169 case WSI_STATE_ESTABLISHED:
170 case WSI_STATE_AWAITING_CLOSE_ACK:
171 if (lws_handshake_client(wsi, &buf, len))
174 case LWS_CONNMODE_WS_SERVING:
176 if (libwebsocket_interpret_incoming_packet(wsi, buf, len) < 0) {
177 lwsl_info("interpret_incoming_packet has bailed\n");
184 lwsl_err("libwebsocket_read: Unhandled state\n");
189 /* Nothing more to do for now. */
190 lwsl_debug("libwebsocket_read: read_ok\n");
195 lwsl_debug("libwebsocket_read: http_complete\n");
197 /* Did the client want to keep the HTTP connection going? */
199 if (wsi->u.http.connection_type == HTTP_CONNECTION_KEEP_ALIVE) {
200 lwsl_debug("libwebsocket_read: keep-alive\n");
201 wsi->state = WSI_STATE_HTTP;
202 wsi->mode = LWS_CONNMODE_HTTP_SERVING;
204 /* He asked for it to stay alive indefinitely */
205 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
207 if (lws_allocate_header_table(wsi))
210 /* If we're (re)starting on headers, need other implied init */
211 wsi->u.hdr.ues = URIES_IDLE;
213 /* If we have more data, loop back around: */
221 lwsl_debug("closing connection at libwebsocket_read bail:\n");
223 libwebsocket_close_and_free_session(context, wsi,
224 LWS_CLOSE_STATUS_NOSTATUS);