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"
28 #ifdef LWS_BUILTIN_GETIFADDRS
29 #include <getifaddrs.h>
34 #include <sys/socket.h>
38 #ifdef LWS_OPENSSL_SUPPORT
39 extern int openssl_websocket_private_data_index;
42 int lws_client_socket_service(struct libwebsocket_context *context, struct libwebsocket *wsi, struct pollfd *pollfd)
49 #ifdef LWS_OPENSSL_SUPPORT
50 char ssl_err_buf[512];
55 case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
57 /* handle proxy hung up on us */
59 if (pollfd->revents & (POLLERR | POLLHUP)) {
61 lwsl_warn("Proxy connection %p (fd=%d) dead\n",
62 (void *)wsi, pollfd->fd);
64 libwebsocket_close_and_free_session(context, wsi,
65 LWS_CLOSE_STATUS_NOSTATUS);
69 n = recv(wsi->sock, pkt, sizeof pkt, 0);
71 libwebsocket_close_and_free_session(context, wsi,
72 LWS_CLOSE_STATUS_NOSTATUS);
73 lwsl_err("ERROR reading from proxy socket\n");
78 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
79 libwebsocket_close_and_free_session(context, wsi,
80 LWS_CLOSE_STATUS_NOSTATUS);
81 lwsl_err("ERROR from proxy: %s\n", pkt);
85 /* clear his proxy connection timeout */
87 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
91 case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
94 * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
95 * timeout protection set in client-handshake.c
98 #ifdef LWS_OPENSSL_SUPPORT
101 * take care of our libwebsocket_callback_on_writable
102 * happening at a time when there's no real connection yet
105 pollfd->events &= ~POLLOUT;
107 /* external POLL support via protocol 0 */
108 context->protocols[0].callback(context, wsi,
109 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
110 (void *)(long)wsi->sock, NULL, POLLOUT);
112 /* we can retry this... so just cook the SSL BIO the first time */
114 if (wsi->use_ssl && !wsi->ssl) {
116 wsi->ssl = SSL_new(context->ssl_client_ctx);
117 wsi->client_bio = BIO_new_socket(wsi->sock,
120 SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
122 BIO_set_nbio(wsi->client_bio, 1); /* nonblocking */
124 SSL_set_ex_data(wsi->ssl,
125 openssl_websocket_private_data_index,
130 n = SSL_connect(wsi->ssl);
133 n = SSL_get_error(wsi->ssl, n);
135 if (n == SSL_ERROR_WANT_READ ||
136 n == SSL_ERROR_WANT_WRITE) {
138 * wants us to retry connect due to state of the
139 * underlying ssl layer... but since it may be
140 * stalled on blocked write, no incoming data may
141 * arrive to trigger the retry. Force (possibly
142 * many if the SSL state persists in returning the
143 * condition code, but other sockets are getting
144 * serviced inbetweentimes) us to get called back
148 lwsl_info("SSL_connect -> SSL_ERROR_WANT_... retrying\n");
149 libwebsocket_callback_on_writable(context, wsi);
151 return 0; /* no error */
158 * retry if new data comes until we
159 * run into the connection timeout or win
162 lwsl_err("SSL connect error %s\n",
163 ERR_error_string(ERR_get_error(),
168 n = SSL_get_verify_result(wsi->ssl);
169 if ((n != X509_V_OK) && (
170 n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
171 wsi->use_ssl != 2)) {
173 lwsl_err("server's cert didn't "
174 "look good %d\n", n);
175 libwebsocket_close_and_free_session(context,
176 wsi, LWS_CLOSE_STATUS_NOSTATUS);
183 p = libwebsockets_generate_client_handshake(context, wsi, p);
185 lwsl_err("Failed to generate handshake for client, closing it\n");
186 libwebsocket_close_and_free_session(context, wsi,
187 LWS_CLOSE_STATUS_NOSTATUS);
191 /* send our request to the server */
193 #ifdef LWS_OPENSSL_SUPPORT
195 n = SSL_write(wsi->ssl, pkt, p - pkt);
198 n = send(wsi->sock, pkt, p - pkt, 0);
201 lwsl_debug("ERROR writing to client socket\n");
202 libwebsocket_close_and_free_session(context, wsi,
203 LWS_CLOSE_STATUS_NOSTATUS);
207 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
208 wsi->u.hdr.lextable_pos = 0;
209 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
210 libwebsocket_set_timeout(wsi,
211 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, AWAITING_TIMEOUT);
215 case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
217 /* handle server hung up on us */
219 if (pollfd->revents & (POLLERR | POLLHUP)) {
221 lwsl_debug("Server connection %p (fd=%d) dead\n",
222 (void *)wsi, pollfd->fd);
228 /* interpret the server response */
231 * HTTP/1.1 101 Switching Protocols
233 * Connection: Upgrade
234 * Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
235 * Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
236 * Sec-WebSocket-Protocol: chat
240 * we have to take some care here to only take from the
241 * socket bytewise. The browser may (and has been seen to
242 * in the case that onopen() performs websocket traffic)
243 * coalesce both handshake response and websocket traffic
244 * in one packet, since at that point the connection is
245 * definitively ready from browser pov.
249 while (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE && len > 0) {
250 #ifdef LWS_OPENSSL_SUPPORT
252 len = SSL_read(wsi->ssl, &c, 1);
255 len = recv(wsi->sock, &c, 1, 0);
257 libwebsocket_parse(wsi, c);
261 * hs may also be coming in multiple packets, there is a 5-sec
262 * libwebsocket timeout still active here too, so if parsing did
263 * not complete just wait for next packet coming in this state
266 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
270 * otherwise deal with the handshake. If there's any
271 * packet traffic already arrived we'll trigger poll() again
272 * right away and deal with it that way
275 return lws_client_interpret_server_handshake(context, wsi);
279 free(wsi->c_protocol);
280 libwebsocket_close_and_free_session(context, wsi,
281 LWS_CLOSE_STATUS_NOSTATUS);
284 case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
285 lwsl_ext("LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT\n");
288 case LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD:
289 lwsl_ext("LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD\n");
300 * In-place str to lower case
313 lws_client_interpret_server_handshake(struct libwebsocket_context *context,
314 struct libwebsocket *wsi)
318 #ifndef LWS_NO_EXTENSIONS
320 struct libwebsocket_extension *ext;
328 * well, what the server sent looked reasonable for syntax.
329 * Now let's confirm it sent all the necessary headers
332 lwsl_parser("WSI_TOKEN_HTTP: %d\n",
333 wsi->utf8_token[WSI_TOKEN_HTTP].token_len);
334 lwsl_parser("WSI_TOKEN_UPGRADE: %d\n",
335 wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len);
336 lwsl_parser("WSI_TOKEN_CONNECTION: %d\n",
337 wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len);
338 lwsl_parser("WSI_TOKEN_ACCEPT: %d\n",
339 wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len);
340 lwsl_parser("WSI_TOKEN_NONCE: %d\n",
341 wsi->utf8_token[WSI_TOKEN_NONCE].token_len);
342 lwsl_parser("WSI_TOKEN_PROTOCOL: %d\n",
343 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len);
346 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
347 if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
348 lwsl_warn("libwebsocket_client_handshake "
349 "server sent bad HTTP response '%s'\n",
350 wsi->utf8_token[WSI_TOKEN_HTTP].token);
354 strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
355 if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
357 lwsl_warn("libwebsocket_client_handshake server "
358 "sent bad Upgrade header '%s'\n",
359 wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
363 strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
364 if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
366 lwsl_warn("libwebsocket_client_handshake server "
367 "sent bad Connection hdr '%s'\n",
368 wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
372 pc = wsi->c_protocol;
374 lwsl_parser("lws_client_interpret_server_handshake: "
375 "NULL c_protocol\n");
377 lwsl_parser("lws_client_interpret_server_handshake: "
378 "cPprotocol='%s'\n", pc);
381 * confirm the protocol the server wants to talk was in the list
382 * of protocols we offered
385 if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
387 lwsl_info("lws_client_interpret_server_handshake "
388 "WSI_TOKEN_PROTOCOL is null\n");
390 * no protocol name to work from,
391 * default to first protocol
393 wsi->protocol = &context->protocols[0];
394 wsi->c_callback = wsi->protocol->callback;
395 free(wsi->c_protocol);
397 goto check_extensions;
400 while (*pc && !okay) {
401 if ((!strncmp(pc, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
402 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
403 (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
404 pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
408 while (*pc && *pc != ',')
410 while (*pc && *pc != ' ')
414 /* done with him now */
417 free(wsi->c_protocol);
420 lwsl_err("libwebsocket_client_handshake server "
421 "sent bad protocol '%s'\n",
422 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
427 * identify the selected protocol struct and set it
430 wsi->protocol = NULL;
431 while (context->protocols[n].callback && !wsi->protocol) { /* Stop after finding first one?? */
432 if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
433 context->protocols[n].name) == 0) {
434 wsi->protocol = &context->protocols[n];
435 wsi->c_callback = wsi->protocol->callback;
440 if (wsi->protocol == NULL) {
441 lwsl_err("libwebsocket_client_handshake server "
442 "requested protocol '%s', which we "
443 "said we supported but we don't!\n",
444 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
450 #ifndef LWS_NO_EXTENSIONS
451 /* instantiate the accepted extensions */
453 if (!wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token_len) {
454 lwsl_ext("no client extenstions allowed by server\n");
459 * break down the list of server accepted extensions
460 * and go through matching them or identifying bogons
463 c = wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token;
467 if (*c && (*c != ',' && *c != ' ' && *c != '\t')) {
469 if (n < sizeof(ext_name) - 1)
482 /* check we actually support it */
484 lwsl_ext("checking client ext %s\n", ext_name);
487 ext = wsi->protocol->owning_server->extensions;
488 while (ext && ext->callback) {
490 if (strcmp(ext_name, ext->name)) {
497 lwsl_ext("instantiating client ext %s\n", ext_name);
499 /* instantiate the extension on this conn */
501 wsi->active_extensions_user[
502 wsi->count_active_extensions] =
503 malloc(ext->per_session_data_size);
504 if (wsi->active_extensions_user[
505 wsi->count_active_extensions] == NULL) {
506 lwsl_err("Out of mem\n");
509 memset(wsi->active_extensions_user[
510 wsi->count_active_extensions], 0,
511 ext->per_session_data_size);
512 wsi->active_extensions[
513 wsi->count_active_extensions] = ext;
515 /* allow him to construct his context */
517 ext->callback(wsi->protocol->owning_server,
519 LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
520 wsi->active_extensions_user[
521 wsi->count_active_extensions],
524 wsi->count_active_extensions++;
530 lwsl_warn("Server said we should use"
531 "an unknown extension '%s'!\n", ext_name);
542 * Confirm his accept token is the one we precomputed
545 if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
546 wsi->u.hdr.initial_handshake_hash_base64)) {
547 lwsl_warn("libwebsocket_client_handshake server "
548 "sent bad ACCEPT '%s' vs computed '%s'\n",
549 wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
550 wsi->u.hdr.initial_handshake_hash_base64);
554 /* allocate the per-connection user memory (if any) */
555 if (wsi->protocol->per_session_data_size &&
556 !libwebsocket_ensure_user_space(wsi))
559 /* clear his proxy connection timeout */
561 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
563 /* mark him as being alive */
565 wsi->state = WSI_STATE_ESTABLISHED;
566 wsi->mode = LWS_CONNMODE_WS_CLIENT;
568 /* union transition */
569 memset(&wsi->u, 0, sizeof wsi->u);
571 lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
573 /* call him back to inform him he is up */
575 wsi->protocol->callback(context, wsi,
576 LWS_CALLBACK_CLIENT_ESTABLISHED,
577 wsi->user_space, NULL, 0);
578 #ifndef LWS_NO_EXTENSIONS
580 * inform all extensions, not just active ones since they
584 ext = context->extensions;
586 while (ext && ext->callback) {
588 for (n = 0; n < wsi->count_active_extensions; n++)
589 if (wsi->active_extensions[n] == ext)
590 v = wsi->active_extensions_user[n];
592 ext->callback(context, ext, wsi,
593 LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED, v, NULL, 0);
602 free(wsi->c_protocol);
605 if (wsi->c_callback) wsi->c_callback(context, wsi,
606 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
609 libwebsocket_close_and_free_session(context, wsi,
610 LWS_CLOSE_STATUS_NOSTATUS); // But this should be LWS_CLOSE_STATUS_PROTOCOL_ERR
617 libwebsockets_generate_client_handshake(struct libwebsocket_context *context,
618 struct libwebsocket *wsi, char *pkt)
624 #ifndef LWS_NO_EXTENSIONS
625 struct libwebsocket_extension *ext;
626 struct libwebsocket_extension *ext1;
629 unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 +
630 MAX_USER_RX_BUFFER + LWS_SEND_BUFFER_POST_PADDING];
631 static const char magic_websocket_guid[] =
632 "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
635 * create the random key
638 n = libwebsockets_get_random(context, hash, 16);
640 lwsl_err("Unable to read from random dev %s\n",
641 SYSTEM_RANDOM_FILEPATH);
647 free(wsi->c_protocol);
648 libwebsocket_close_and_free_session(context, wsi,
649 LWS_CLOSE_STATUS_NOSTATUS);
653 lws_b64_encode_string(hash, 16, key_b64, sizeof key_b64);
656 * 00 example client handshake
658 * GET /socket.io/websocket HTTP/1.1
660 * Connection: Upgrade
661 * Host: 127.0.0.1:9999
662 * Origin: http://127.0.0.1
663 * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7 92 ^
664 * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
665 * Cookie: socketio=websocket
669 * 04 example client handshake
672 * Host: server.example.com
674 * Connection: Upgrade
675 * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
676 * Sec-WebSocket-Origin: http://example.com
677 * Sec-WebSocket-Protocol: chat, superchat
678 * Sec-WebSocket-Version: 4
681 p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
683 p += sprintf(p, "Pragma: no-cache\x0d\x0a"
684 "Cache-Control: no-cache\x0d\x0a");
686 p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
687 p += sprintf(p, "Upgrade: websocket\x0d\x0a"
688 "Connection: Upgrade\x0d\x0a"
689 "Sec-WebSocket-Key: ");
691 p += strlen(key_b64);
692 p += sprintf(p, "\x0d\x0a");
694 if (wsi->ietf_spec_revision == 13)
695 p += sprintf(p, "Origin: %s\x0d\x0a", wsi->c_origin);
697 p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
701 p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
704 /* tell the server what extensions we could support */
706 p += sprintf(p, "Sec-WebSocket-Extensions: ");
707 #ifndef LWS_NO_EXTENSIONS
708 ext = context->extensions;
709 while (ext && ext->callback) {
712 ext1 = context->extensions;
714 while (ext1 && ext1->callback) {
715 n |= ext1->callback(context, ext1, wsi,
716 LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
717 NULL, (char *)ext->name, 0);
722 if (n) { /* an extension vetos us */
723 lwsl_ext("ext %s vetoed\n", (char *)ext->name);
728 n = context->protocols[0].callback(context, wsi,
729 LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
730 wsi->user_space, (char *)ext->name, 0);
733 * zero return from callback means
734 * go ahead and allow the extension,
735 * it's what we get if the callback is
748 p += sprintf(p, "%s", ext->name);
754 p += sprintf(p, "\x0d\x0a");
756 if (wsi->ietf_spec_revision)
757 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
758 wsi->ietf_spec_revision);
760 /* give userland a chance to append, eg, cookies */
762 context->protocols[0].callback(context, wsi,
763 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
764 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
766 p += sprintf(p, "\x0d\x0a");
768 /* prepare the expected server accept response */
770 strcpy((char *)buf, key_b64);
771 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
773 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
775 lws_b64_encode_string(hash, 20,
776 wsi->u.hdr.initial_handshake_hash_base64,
777 sizeof wsi->u.hdr.initial_handshake_hash_base64);
779 /* done with these now */