Don't care for the human-readable part of "HTTP/1.1 101" reply
[profile/ivi/libwebsockets.git] / lib / libwebsockets.c
1 /*
2  * libwebsockets - small server side websockets and web server implementation
3  *
4  * Copyright (C) 2010 Andy Green <andy@warmcat.com>
5  *
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.
10  *
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.
15  *
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,
19  *  MA  02110-1301  USA
20  */
21
22 #include "private-libwebsockets.h"
23
24 #ifdef WIN32
25
26 #else
27 #include <ifaddrs.h>
28 #include <sys/un.h>
29 #endif
30
31 #ifdef LWS_OPENSSL_SUPPORT
32 int openssl_websocket_private_data_index;
33 #endif
34
35 /*
36  * In-place str to lower case
37  */
38
39 static void
40 strtolower(char *s)
41 {
42         while (*s) {
43                 *s = tolower(*s);
44                 s++;
45         }
46 }
47
48 /* file descriptor hash management */
49
50 struct libwebsocket *
51 wsi_from_fd(struct libwebsocket_context *context, int fd)
52 {
53         int h = LWS_FD_HASH(fd);
54         int n = 0;
55
56         for (n = 0; n < context->fd_hashtable[h].length; n++)
57                 if (context->fd_hashtable[h].wsi[n]->sock == fd)
58                         return context->fd_hashtable[h].wsi[n];
59
60         return NULL;
61 }
62
63 int
64 insert_wsi(struct libwebsocket_context *context, struct libwebsocket *wsi)
65 {
66         int h = LWS_FD_HASH(wsi->sock);
67
68         if (context->fd_hashtable[h].length == MAX_CLIENTS - 1) {
69                 fprintf(stderr, "hash table overflow\n");
70                 return 1;
71         }
72
73         context->fd_hashtable[h].wsi[context->fd_hashtable[h].length++] = wsi;
74
75         return 0;
76 }
77
78 int
79 delete_from_fd(struct libwebsocket_context *context, int fd)
80 {
81         int h = LWS_FD_HASH(fd);
82         int n = 0;
83
84         for (n = 0; n < context->fd_hashtable[h].length; n++)
85                 if (context->fd_hashtable[h].wsi[n]->sock == fd) {
86                         while (n < context->fd_hashtable[h].length) {
87                                 context->fd_hashtable[h].wsi[n] =
88                                             context->fd_hashtable[h].wsi[n + 1];
89                                 n++;
90                         }
91                         context->fd_hashtable[h].length--;
92
93                         return 0;
94                 }
95
96         fprintf(stderr, "Failed to find fd %d requested for "
97                                                    "delete in hashtable\n", fd);
98         return 1;
99 }
100
101 #ifdef LWS_OPENSSL_SUPPORT
102 static void
103 libwebsockets_decode_ssl_error(void)
104 {
105         char buf[256];
106         u_long err;
107
108         while ((err = ERR_get_error()) != 0) {
109                 ERR_error_string_n(err, buf, sizeof(buf));
110                 fprintf(stderr, "*** %s\n", buf);
111         }
112 }
113 #endif
114
115
116 static int
117 interface_to_sa(const char* ifname, struct sockaddr_in *addr, size_t addrlen)
118 {
119         int rc = -1;
120 #ifdef WIN32
121         // TODO
122 #else
123         struct ifaddrs *ifr;
124         struct ifaddrs *ifc;
125         struct sockaddr_in *sin;
126
127         getifaddrs(&ifr);
128         for (ifc = ifr; ifc != NULL; ifc = ifc->ifa_next) {
129                 if (strcmp(ifc->ifa_name, ifname))
130                         continue;
131                 if (ifc->ifa_addr == NULL)
132                         continue;
133                 sin = (struct sockaddr_in *)ifc->ifa_addr;
134                 if (sin->sin_family != AF_INET)
135                         continue;
136                 memcpy(addr, sin, addrlen);
137                 rc = 0; 
138         }
139
140         freeifaddrs(ifr);
141 #endif
142         return rc;
143 }
144
145 void
146 libwebsocket_close_and_free_session(struct libwebsocket_context *context,
147                          struct libwebsocket *wsi, enum lws_close_status reason)
148 {
149         int n;
150         int old_state;
151         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
152                                                   LWS_SEND_BUFFER_POST_PADDING];
153         int ret;
154         int m;
155         struct lws_tokens eff_buf;
156         struct libwebsocket_extension *ext;
157
158         if (!wsi)
159                 return;
160
161         old_state = wsi->state;
162
163         if (old_state == WSI_STATE_DEAD_SOCKET)
164                 return;
165
166         wsi->close_reason = reason;
167
168         /*
169          * are his extensions okay with him closing?  Eg he might be a mux
170          * parent and just his ch1 aspect is closing?
171          */
172
173
174         for (n = 0; n < wsi->count_active_extensions; n++) {
175                 if (!wsi->active_extensions[n]->callback)
176                         continue;
177
178                 m = wsi->active_extensions[n]->callback(context,
179                         wsi->active_extensions[n], wsi,
180                         LWS_EXT_CALLBACK_CHECK_OK_TO_REALLY_CLOSE,
181                                        wsi->active_extensions_user[n], NULL, 0);
182
183                 /*
184                  * if somebody vetoed actually closing him at this time....
185                  * up to the extension to track the attempted close, let's
186                  * just bail
187                  */
188
189                 if (m) {
190                         debug("extension vetoed close\n");
191                         return;
192                 }
193         }
194
195
196
197         /*
198          * flush any tx pending from extensions, since we may send close packet
199          * if there are problems with send, just nuke the connection
200          */
201
202         ret = 1;
203         while (ret == 1) {
204
205                 /* default to nobody has more to spill */
206
207                 ret = 0;
208                 eff_buf.token = NULL;
209                 eff_buf.token_len = 0;
210
211                 /* show every extension the new incoming data */
212
213                 for (n = 0; n < wsi->count_active_extensions; n++) {
214                         m = wsi->active_extensions[n]->callback(
215                                         wsi->protocol->owning_server,
216                                         wsi->active_extensions[n], wsi,
217                                         LWS_EXT_CALLBACK_FLUSH_PENDING_TX,
218                                    wsi->active_extensions_user[n], &eff_buf, 0);
219                         if (m < 0) {
220                                 fprintf(stderr, "Extension reports "
221                                                                "fatal error\n");
222                                 goto just_kill_connection;
223                         }
224                         if (m)
225                                 /*
226                                  * at least one extension told us he has more
227                                  * to spill, so we will go around again after
228                                  */
229                                 ret = 1;
230                 }
231
232                 /* assuming they left us something to send, send it */
233
234                 if (eff_buf.token_len)
235                         if (lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
236                                                              eff_buf.token_len))
237                                 goto just_kill_connection;
238         }
239
240         /*
241          * signal we are closing, libsocket_write will
242          * add any necessary version-specific stuff.  If the write fails,
243          * no worries we are closing anyway.  If we didn't initiate this
244          * close, then our state has been changed to
245          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this.
246          *
247          * Likewise if it's a second call to close this connection after we
248          * sent the close indication to the peer already, we are in state
249          * WSI_STATE_AWAITING_CLOSE_ACK and will skip doing this a second time.
250          */
251
252         if (old_state == WSI_STATE_ESTABLISHED &&
253                                           reason != LWS_CLOSE_STATUS_NOSTATUS) {
254
255                 debug("sending close indication...\n");
256
257                 n = libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING],
258                                                             0, LWS_WRITE_CLOSE);
259                 if (!n) {
260                         /*
261                          * we have sent a nice protocol level indication we
262                          * now wish to close, we should not send anything more
263                          */
264
265                         wsi->state = WSI_STATE_AWAITING_CLOSE_ACK;
266
267                         /* and we should wait for a reply for a bit */
268
269                         libwebsocket_set_timeout(wsi,
270                                                   PENDING_TIMEOUT_CLOSE_ACK, 5);
271
272                         debug("sent close indication, awaiting ack\n");
273
274                         return;
275                 }
276
277                 /* else, the send failed and we should just hang up */
278         }
279
280 just_kill_connection:
281
282         debug("libwebsocket_close_and_free_session: just_kill_connection\n");
283
284         /*
285          * we won't be servicing or receiving anything further from this guy
286          * remove this fd from wsi mapping hashtable
287          */
288
289         if (wsi->sock)
290                 delete_from_fd(context, wsi->sock);
291
292         /* delete it from the internal poll list if still present */
293
294         for (n = 0; n < context->fds_count; n++) {
295                 if (context->fds[n].fd != wsi->sock)
296                         continue;
297                 while (n < context->fds_count - 1) {
298                         context->fds[n] = context->fds[n + 1];
299                         n++;
300                 }
301                 context->fds_count--;
302                 /* we only have to deal with one */
303                 n = context->fds_count;
304         }
305
306         /* remove also from external POLL support via protocol 0 */
307         if (wsi->sock)
308                 context->protocols[0].callback(context, wsi,
309                     LWS_CALLBACK_DEL_POLL_FD, (void *)(long)wsi->sock, NULL, 0);
310
311         wsi->state = WSI_STATE_DEAD_SOCKET;
312
313         /* tell the user it's all over for this guy */
314
315         if (wsi->protocol && wsi->protocol->callback &&
316                                 ((old_state == WSI_STATE_ESTABLISHED) ||
317                                  (old_state == WSI_STATE_RETURNED_CLOSE_ALREADY) ||
318                                  (old_state == WSI_STATE_AWAITING_CLOSE_ACK))) {
319                 debug("calling back CLOSED\n");
320                 wsi->protocol->callback(context, wsi, LWS_CALLBACK_CLOSED,
321                                                       wsi->user_space, NULL, 0);
322         } else
323                 debug("not calling back closed due to old_state=%d\n",
324                                                                      old_state);
325
326
327         /* deallocate any active extension contexts */
328
329         for (n = 0; n < wsi->count_active_extensions; n++) {
330                 if (!wsi->active_extensions[n]->callback)
331                         continue;
332
333                 wsi->active_extensions[n]->callback(context,
334                         wsi->active_extensions[n], wsi,
335                                 LWS_EXT_CALLBACK_DESTROY,
336                                        wsi->active_extensions_user[n], NULL, 0);
337
338                 free(wsi->active_extensions_user[n]);
339         }
340
341         /*
342          * inform all extensions in case they tracked this guy out of band
343          * even though not active on him specifically
344          */
345
346         ext = context->extensions;
347         while (ext && ext->callback) {
348                 ext->callback(context, ext, wsi,
349                                 LWS_EXT_CALLBACK_DESTROY_ANY_WSI_CLOSING,
350                                        NULL, NULL, 0);
351                 ext++;
352         }
353
354         /* free up his parsing allocations */
355
356         for (n = 0; n < WSI_TOKEN_COUNT; n++)
357                 if (wsi->utf8_token[n].token)
358                         free(wsi->utf8_token[n].token);
359
360         if (wsi->c_address)
361                 free(wsi->c_address);
362
363 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
364
365 #ifdef LWS_OPENSSL_SUPPORT
366         if (wsi->ssl) {
367                 n = SSL_get_fd(wsi->ssl);
368                 SSL_shutdown(wsi->ssl);
369 #ifdef WIN32
370                 closesocket(n);
371 #else
372                 close(n);
373 #endif
374                 SSL_free(wsi->ssl);
375         } else {
376 #endif
377                 shutdown(wsi->sock, SHUT_RDWR);
378 #ifdef WIN32
379                 if (wsi->sock)
380                         closesocket(wsi->sock);
381 #else
382                 if (wsi->sock)
383                         close(wsi->sock);
384 #endif
385 #ifdef LWS_OPENSSL_SUPPORT
386         }
387 #endif
388         if (wsi->user_space)
389                 free(wsi->user_space);
390
391         free(wsi);
392 }
393
394 /**
395  * libwebsockets_hangup_on_client() - Server calls to terminate client
396  *                                      connection
397  * @context:    libwebsockets context
398  * @fd:         Connection socket descriptor
399  */
400
401 void
402 libwebsockets_hangup_on_client(struct libwebsocket_context *context, int fd)
403 {
404         struct libwebsocket *wsi = wsi_from_fd(context, fd);
405
406         if (wsi == NULL)
407                 return;
408
409         libwebsocket_close_and_free_session(context, wsi,
410                                                      LWS_CLOSE_STATUS_NOSTATUS);
411 }
412
413
414 /**
415  * libwebsockets_get_peer_addresses() - Get client address information
416  * @fd:         Connection socket descriptor
417  * @name:       Buffer to take client address name
418  * @name_len:   Length of client address name buffer
419  * @rip:        Buffer to take client address IP qotted quad
420  * @rip_len:    Length of client address IP buffer
421  *
422  *      This function fills in @name and @rip with the name and IP of
423  *      the client connected with socket descriptor @fd.  Names may be
424  *      truncated if there is not enough room.  If either cannot be
425  *      determined, they will be returned as valid zero-length strings.
426  */
427
428 void
429 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
430                                         char *rip, int rip_len)
431 {
432         unsigned int len;
433         struct sockaddr_in sin;
434         struct hostent *host;
435         struct hostent *host1;
436         char ip[128];
437         unsigned char *p;
438         int n;
439         struct sockaddr_un *un;
440
441         rip[0] = '\0';
442         name[0] = '\0';
443
444         len = sizeof sin;
445         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
446                 perror("getpeername");
447                 return;
448         }
449                 
450         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
451                                                                        AF_INET);
452         if (host == NULL) {
453                 perror("gethostbyaddr");
454                 return;
455         }
456
457         strncpy(name, host->h_name, name_len);
458         name[name_len - 1] = '\0';
459
460         host1 = gethostbyname(host->h_name);
461         if (host1 == NULL)
462                 return;
463         p = (unsigned char *)host1;
464         n = 0;
465         while (p != NULL) {
466                 p = (unsigned char *)host1->h_addr_list[n++];
467                 if (p == NULL)
468                         continue;
469                 if ((host1->h_addrtype != AF_INET)
470 #ifdef AF_LOCAL
471                         && (host1->h_addrtype != AF_LOCAL)
472 #endif
473                         )
474                         continue;
475
476                 if (host1->h_addrtype == AF_INET)
477                         sprintf(ip, "%u.%u.%u.%u", p[0], p[1], p[2], p[3]);
478 #ifdef AF_LOCAL
479                 else {
480                         un = (struct sockaddr_un *)p;
481                         strncpy(ip, un->sun_path, sizeof(ip) -1);
482                         ip[sizeof(ip) - 1] = '\0';
483                 }
484 #endif
485                 p = NULL;
486                 strncpy(rip, ip, rip_len);
487                 rip[rip_len - 1] = '\0';
488         }
489 }
490
491 int libwebsockets_get_random(struct libwebsocket_context *context,
492                                                              void *buf, int len)
493 {
494         int n;
495         char *p = buf;
496
497 #ifdef WIN32
498         for (n = 0; n < len; n++)
499                 p[n] = (unsigned char)rand();
500 #else
501         n = read(context->fd_random, p, len);
502 #endif
503
504         return n;
505 }
506
507 unsigned char *
508 libwebsockets_SHA1(const unsigned char *d, size_t n, unsigned char *md)
509 {
510         return SHA1(d, n, md);
511 }
512
513 void libwebsockets_00_spaceout(char *key, int spaces, int seed)
514 {
515         char *p;
516         
517         key++;
518         while (spaces--) {
519                 if (*key && (seed & 1))
520                         key++;
521                 seed >>= 1;
522                 
523                 p = key + strlen(key);
524                 while (p >= key) {
525                         p[1] = p[0];
526                         p--;
527                 }
528                 *key++ = ' ';
529         }
530 }
531
532 void libwebsockets_00_spam(char *key, int count, int seed)
533 {
534         char *p;
535
536         key++;
537         while (count--) {
538                 
539                 if (*key && (seed & 1))
540                         key++;
541                 seed >>= 1;
542
543                 p = key + strlen(key);
544                 while (p >= key) {
545                         p[1] = p[0];
546                         p--;
547                 }
548                 *key++ = 0x21 + ((seed & 0xffff) % 15);
549                 /* 4 would use it up too fast.. not like it matters */
550                 seed >>= 1;
551         }
552 }
553
554 int lws_send_pipe_choked(struct libwebsocket *wsi)
555 {
556         struct pollfd fds;
557
558         fds.fd = wsi->sock;
559         fds.events = POLLOUT;
560         fds.revents = 0;
561
562         if (poll(&fds, 1, 0) != 1)
563                 return 1;
564
565         if ((fds.revents & POLLOUT) == 0)
566                 return 1;
567
568         /* okay to send another packet without blocking */
569
570         return 0;
571 }
572
573 int
574 lws_handle_POLLOUT_event(struct libwebsocket_context *context,
575                                 struct libwebsocket *wsi, struct pollfd *pollfd)
576 {
577         struct lws_tokens eff_buf;
578         int n;
579         int ret;
580         int m;
581         int handled = 0;
582
583         for (n = 0; n < wsi->count_active_extensions; n++) {
584                 if (!wsi->active_extensions[n]->callback)
585                         continue;
586
587                 m = wsi->active_extensions[n]->callback(context,
588                         wsi->active_extensions[n], wsi,
589                         LWS_EXT_CALLBACK_IS_WRITEABLE,
590                                        wsi->active_extensions_user[n], NULL, 0);
591                 if (m > handled)
592                         handled = m;
593         }
594
595         if (handled == 1)
596                 goto notify_action;
597
598         if (!wsi->extension_data_pending || handled == 2)
599                 goto user_service;
600
601         /*
602          * check in on the active extensions, see if they
603          * had pending stuff to spill... they need to get the
604          * first look-in otherwise sequence will be disordered
605          *
606          * NULL, zero-length eff_buf means just spill pending
607          */
608
609         ret = 1;
610         while (ret == 1) {
611
612                 /* default to nobody has more to spill */
613
614                 ret = 0;
615                 eff_buf.token = NULL;
616                 eff_buf.token_len = 0;
617
618                 /* give every extension a chance to spill */
619
620                 for (n = 0; n < wsi->count_active_extensions; n++) {
621                         m = wsi->active_extensions[n]->callback(
622                                 wsi->protocol->owning_server,
623                                 wsi->active_extensions[n], wsi,
624                                         LWS_EXT_CALLBACK_PACKET_TX_PRESEND,
625                                    wsi->active_extensions_user[n], &eff_buf, 0);
626                         if (m < 0) {
627                                 fprintf(stderr, "extension reports fatal error\n");
628                                 return -1;
629                         }
630                         if (m)
631                                 /*
632                                  * at least one extension told us he has more
633                                  * to spill, so we will go around again after
634                                  */
635                                 ret = 1;
636                 }
637
638                 /* assuming they gave us something to send, send it */
639
640                 if (eff_buf.token_len) {
641                         if (lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
642                                                              eff_buf.token_len))
643                                 return -1;
644                 } else
645                         continue;
646
647                 /* no extension has more to spill */
648
649                 if (!ret)
650                         continue;
651
652                 /*
653                  * There's more to spill from an extension, but we just sent
654                  * something... did that leave the pipe choked?
655                  */
656
657                 if (!lws_send_pipe_choked(wsi))
658                         /* no we could add more */
659                         continue;
660
661                 debug("choked in POLLOUT service\n");
662
663                 /*
664                  * Yes, he's choked.  Leave the POLLOUT masked on so we will
665                  * come back here when he is unchoked.  Don't call the user
666                  * callback to enforce ordering of spilling, he'll get called
667                  * when we come back here and there's nothing more to spill.
668                  */
669
670                 return 0;
671         }
672
673         wsi->extension_data_pending = 0;
674
675 user_service:
676         /* one shot */
677
678         if (pollfd) {
679                 pollfd->events &= ~POLLOUT;
680
681                 /* external POLL support via protocol 0 */
682                 context->protocols[0].callback(context, wsi,
683                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
684                         (void *)(long)wsi->sock, NULL, POLLOUT);
685         }
686
687 notify_action:
688
689         if (wsi->mode == LWS_CONNMODE_WS_CLIENT)
690                 n = LWS_CALLBACK_CLIENT_WRITEABLE;
691         else
692                 n = LWS_CALLBACK_SERVER_WRITEABLE;
693
694         wsi->protocol->callback(context, wsi, n, wsi->user_space, NULL, 0);
695
696         return 0;
697 }
698
699
700
701 void
702 libwebsocket_service_timeout_check(struct libwebsocket_context *context,
703                                      struct libwebsocket *wsi, unsigned int sec)
704 {
705         int n;
706
707         /*
708          * if extensions want in on it (eg, we are a mux parent)
709          * give them a chance to service child timeouts
710          */
711
712         for (n = 0; n < wsi->count_active_extensions; n++)
713                 wsi->active_extensions[n]->callback(
714                                     context, wsi->active_extensions[n],
715                                     wsi, LWS_EXT_CALLBACK_1HZ,
716                                     wsi->active_extensions_user[n], NULL, sec);
717
718         if (!wsi->pending_timeout)
719                 return;
720                           
721         /*
722          * if we went beyond the allowed time, kill the
723          * connection
724          */
725
726         if (sec > wsi->pending_timeout_limit) {
727                 debug("TIMEDOUT WAITING\n");
728                 libwebsocket_close_and_free_session(context,
729                                 wsi, LWS_CLOSE_STATUS_NOSTATUS);
730         }
731 }
732
733 struct libwebsocket *
734 libwebsocket_create_new_server_wsi(struct libwebsocket_context *context)
735 {
736         struct libwebsocket *new_wsi;
737         int n;
738
739         new_wsi = malloc(sizeof(struct libwebsocket));
740         if (new_wsi == NULL) {
741                 fprintf(stderr, "Out of memory for new connection\n");
742                 return NULL;
743         }
744
745         memset(new_wsi, 0, sizeof (struct libwebsocket));
746         new_wsi->count_active_extensions = 0;
747         new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
748
749         /* intialize the instance struct */
750
751         new_wsi->state = WSI_STATE_HTTP;
752         new_wsi->name_buffer_pos = 0;
753         new_wsi->mode = LWS_CONNMODE_WS_SERVING;
754
755         for (n = 0; n < WSI_TOKEN_COUNT; n++) {
756                 new_wsi->utf8_token[n].token = NULL;
757                 new_wsi->utf8_token[n].token_len = 0;
758         }
759
760         /*
761          * these can only be set once the protocol is known
762          * we set an unestablished connection's protocol pointer
763          * to the start of the supported list, so it can look
764          * for matching ones during the handshake
765          */
766         new_wsi->protocol = context->protocols;
767         new_wsi->user_space = NULL;
768
769         /*
770          * Default protocol is 76 / 00
771          * After 76, there's a header specified to inform which
772          * draft the client wants, when that's seen we modify
773          * the individual connection's spec revision accordingly
774          */
775         new_wsi->ietf_spec_revision = 0;
776
777         return new_wsi;
778 }
779
780 char *
781 libwebsockets_generate_client_handshake(struct libwebsocket_context *context,
782                 struct libwebsocket *wsi, char *pkt)
783 {
784         char hash[20];
785         char *p = pkt;
786         int n;
787         struct libwebsocket_extension *ext;
788         struct libwebsocket_extension *ext1;
789         int ext_count = 0;
790         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 + MAX_BROADCAST_PAYLOAD +
791                                                   LWS_SEND_BUFFER_POST_PADDING];
792         static const char magic_websocket_guid[] =
793                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
794
795         /*
796          * create the random key
797          */
798
799         n = libwebsockets_get_random(context, hash, 16);
800         if (n != 16) {
801                 fprintf(stderr, "Unable to read from random dev %s\n",
802                                                 SYSTEM_RANDOM_FILEPATH);
803                 free(wsi->c_path);
804                 free(wsi->c_host);
805                 if (wsi->c_origin)
806                         free(wsi->c_origin);
807                 if (wsi->c_protocol)
808                         free(wsi->c_protocol);
809                 libwebsocket_close_and_free_session(context, wsi,
810                                              LWS_CLOSE_STATUS_NOSTATUS);
811                 return NULL;
812         }
813
814         lws_b64_encode_string(hash, 16, wsi->key_b64,
815                                                    sizeof wsi->key_b64);
816
817         /*
818          * 00 example client handshake
819          *
820          * GET /socket.io/websocket HTTP/1.1
821          * Upgrade: WebSocket
822          * Connection: Upgrade
823          * Host: 127.0.0.1:9999
824          * Origin: http://127.0.0.1
825          * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7  92 ^
826          * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
827          * Cookie: socketio=websocket
828          *
829          * (Á®Ä0¶†≥
830          *
831          * 04 example client handshake
832          *
833          * GET /chat HTTP/1.1
834          * Host: server.example.com
835          * Upgrade: websocket
836          * Connection: Upgrade
837          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
838          * Sec-WebSocket-Origin: http://example.com
839          * Sec-WebSocket-Protocol: chat, superchat
840          * Sec-WebSocket-Version: 4
841          */
842
843         p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
844
845         if (wsi->ietf_spec_revision == 0) {
846                 unsigned char spaces_1, spaces_2;
847                 unsigned int max_1, max_2;
848                 unsigned int num_1, num_2;
849                 unsigned long product_1, product_2;
850                 char key_1[40];
851                 char key_2[40];
852                 unsigned int seed;
853                 unsigned int count;
854                 char challenge[16];
855
856                 libwebsockets_get_random(context, &spaces_1,
857                                                           sizeof(char));
858                 libwebsockets_get_random(context, &spaces_2,
859                                                           sizeof(char));
860
861                 spaces_1 = (spaces_1 % 12) + 1;
862                 spaces_2 = (spaces_2 % 12) + 1;
863
864                 max_1 = 4294967295 / spaces_1;
865                 max_2 = 4294967295 / spaces_2;
866
867                 libwebsockets_get_random(context, &num_1, sizeof(int));
868                 libwebsockets_get_random(context, &num_2, sizeof(int));
869
870                 num_1 = (num_1 % max_1);
871                 num_2 = (num_2 % max_2);
872
873                 challenge[0] = num_1 >> 24;
874                 challenge[1] = num_1 >> 16;
875                 challenge[2] = num_1 >> 8;
876                 challenge[3] = num_1;
877                 challenge[4] = num_2 >> 24;
878                 challenge[5] = num_2 >> 16;
879                 challenge[6] = num_2 >> 8;
880                 challenge[7] = num_2;
881
882                 product_1 = num_1 * spaces_1;
883                 product_2 = num_2 * spaces_2;
884
885                 sprintf(key_1, "%lu", product_1);
886                 sprintf(key_2, "%lu", product_2);
887
888                 libwebsockets_get_random(context, &seed, sizeof(int));
889                 libwebsockets_get_random(context, &count, sizeof(int));
890
891                 libwebsockets_00_spam(key_1, (count % 12) + 1, seed);
892
893                 libwebsockets_get_random(context, &seed, sizeof(int));
894                 libwebsockets_get_random(context, &count, sizeof(int));
895
896                 libwebsockets_00_spam(key_2, (count % 12) + 1, seed);
897
898                 libwebsockets_get_random(context, &seed, sizeof(int));
899
900                 libwebsockets_00_spaceout(key_1, spaces_1, seed);
901                 libwebsockets_00_spaceout(key_2, spaces_2, seed >> 16);
902
903                 p += sprintf(p, "Upgrade: WebSocket\x0d\x0a"
904                         "Connection: Upgrade\x0d\x0aHost: %s\x0d\x0a",
905                         wsi->c_host);
906                 if (wsi->c_origin)
907                         p += sprintf(p, "Origin: %s\x0d\x0a",
908                         wsi->c_origin);
909
910                 if (wsi->c_protocol)
911                         p += sprintf(p, "Sec-WebSocket-Protocol: %s"
912                                          "\x0d\x0a", wsi->c_protocol);
913
914                 p += sprintf(p, "Sec-WebSocket-Key1: %s\x0d\x0a",
915                         key_1);
916                 p += sprintf(p, "Sec-WebSocket-Key2: %s\x0d\x0a",
917                         key_2);
918
919                 /* give userland a chance to append, eg, cookies */
920
921                 context->protocols[0].callback(context, wsi,
922                         LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
923                                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
924
925                 p += sprintf(p, "\x0d\x0a");
926
927                 if (libwebsockets_get_random(context, p, 8) != 8)
928                         return NULL;
929                 memcpy(&challenge[8], p, 8);
930                 p += 8;
931
932                 /* precompute what we want to see from the server */
933
934                 MD5((unsigned char *)challenge, 16,
935                    (unsigned char *)wsi->initial_handshake_hash_base64);
936
937                 goto issue_hdr;
938         }
939
940         p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
941         p += sprintf(p, "Upgrade: websocket\x0d\x0a");
942         p += sprintf(p, "Connection: Upgrade\x0d\x0a"
943                                 "Sec-WebSocket-Key: ");
944         strcpy(p, wsi->key_b64);
945         p += strlen(wsi->key_b64);
946         p += sprintf(p, "\x0d\x0a");
947         if (wsi->c_origin)
948                 p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
949                                                          wsi->c_origin);
950         if (wsi->c_protocol)
951                 p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
952                                                        wsi->c_protocol);
953
954         /* tell the server what extensions we could support */
955
956         p += sprintf(p, "Sec-WebSocket-Extensions: ");
957
958         ext =context->extensions;
959         while (ext && ext->callback) {
960
961                 n = 0;
962                 ext1 = context->extensions;
963                 while (ext1 && ext1->callback) {
964
965                         n |= ext1->callback(context, ext1, wsi,
966                                 LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
967                                         NULL, (char *)ext->name, 0);
968
969                         ext1++;
970                 }
971
972                 if (n) {
973
974                         /* an extension vetos us */
975                         debug("ext %s vetoed\n", (char *)ext->name);
976                         ext++;
977                         continue;
978                 }
979
980                 n = context->protocols[0].callback(context, wsi,
981                         LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
982                                 wsi->user_space, (char *)ext->name, 0);
983
984                 /*
985                  * zero return from callback means
986                  * go ahead and allow the extension,
987                  * it's what we get if the callback is
988                  * unhandled
989                  */
990
991                 if (n) {
992                         ext++;
993                         continue;
994                 }
995
996                 /* apply it */
997
998                 if (ext_count)
999                         *p++ = ',';
1000                 p += sprintf(p, "%s", ext->name);
1001                 ext_count++;
1002
1003                 ext++;
1004         }
1005
1006         p += sprintf(p, "\x0d\x0a");
1007
1008         if (wsi->ietf_spec_revision)
1009                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
1010                                                wsi->ietf_spec_revision);
1011
1012         /* give userland a chance to append, eg, cookies */
1013
1014         context->protocols[0].callback(context, wsi,
1015                 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
1016                 NULL, &p, (pkt + sizeof(pkt)) - p - 12);
1017
1018         p += sprintf(p, "\x0d\x0a");
1019
1020         /* prepare the expected server accept response */
1021
1022         strcpy((char *)buf, wsi->key_b64);
1023         strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
1024
1025         SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
1026
1027         lws_b64_encode_string(hash, 20,
1028                         wsi->initial_handshake_hash_base64,
1029                              sizeof wsi->initial_handshake_hash_base64);
1030
1031 issue_hdr:
1032
1033 //      puts(pkt);
1034
1035         /* done with these now */
1036
1037         free(wsi->c_path);
1038         free(wsi->c_host);
1039         if (wsi->c_origin)
1040                 free(wsi->c_origin);
1041
1042         return p;
1043 }
1044
1045 int
1046 lws_client_interpret_server_handshake(struct libwebsocket_context *context,
1047                 struct libwebsocket *wsi)
1048 {
1049         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 + MAX_BROADCAST_PAYLOAD +
1050                                                   LWS_SEND_BUFFER_POST_PADDING];
1051         char pkt[1024];
1052         char *p = &pkt[0];
1053         const char *pc;
1054         const char *c;
1055         int more = 1;
1056         int okay = 0;
1057         char ext_name[128];
1058         struct libwebsocket_extension *ext;
1059         void *v;
1060         int len = 0;
1061         int n;
1062         static const char magic_websocket_04_masking_guid[] =
1063                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
1064
1065         /*
1066          * 00 / 76 -->
1067          *
1068          * HTTP/1.1 101 WebSocket Protocol Handshake
1069          * Upgrade: WebSocket
1070          * Connection: Upgrade
1071          * Sec-WebSocket-Origin: http://127.0.0.1
1072          * Sec-WebSocket-Location: ws://127.0.0.1:9999/socket.io/websocket
1073          *
1074          * xxxxxxxxxxxxxxxx
1075          */
1076
1077         if (wsi->ietf_spec_revision == 0) {
1078                 if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
1079                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
1080                         !wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len ||
1081                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
1082                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
1083                         wsi->c_protocol != NULL)) {
1084                         debug("libwebsocket_client_handshake "
1085                                         "missing required header(s)\n");
1086                         pkt[len] = '\0';
1087                         debug("%s", pkt);
1088                         goto bail3;
1089                 }
1090
1091                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
1092                 if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
1093                                                             "101", 3)) {
1094                         fprintf(stderr, "libwebsocket_client_handshake "
1095                                 "server sent bad HTTP response '%s'\n",
1096                                 wsi->utf8_token[WSI_TOKEN_HTTP].token);
1097                         goto bail3;
1098                 }
1099
1100                 if (wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len <
1101                                                                    16) {
1102                         fprintf(stderr, "libwebsocket_client_handshake "
1103                                 "challenge reply too short %d\n",
1104                                 wsi->utf8_token[
1105                                         WSI_TOKEN_CHALLENGE].token_len);
1106                         pkt[len] = '\0';
1107                         debug("%s", pkt);
1108                         goto bail3;
1109
1110                 }
1111
1112                 goto select_protocol;
1113         }
1114
1115         /*
1116          * well, what the server sent looked reasonable for syntax.
1117          * Now let's confirm it sent all the necessary headers
1118          */
1119 #if 0
1120         fprintf(stderr, "WSI_TOKEN_HTTP: %d\n", wsi->utf8_token[WSI_TOKEN_HTTP].token_len);
1121         fprintf(stderr, "WSI_TOKEN_UPGRADE: %d\n", wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len);
1122         fprintf(stderr, "WSI_TOKEN_CONNECTION: %d\n", wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len);
1123         fprintf(stderr, "WSI_TOKEN_ACCEPT: %d\n", wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len);
1124         fprintf(stderr, "WSI_TOKEN_NONCE: %d\n", wsi->utf8_token[WSI_TOKEN_NONCE].token_len);
1125         fprintf(stderr, "WSI_TOKEN_PROTOCOL: %d\n", wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len);
1126 #endif
1127          if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
1128                 !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
1129                 !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
1130                 !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
1131                 (!wsi->utf8_token[WSI_TOKEN_NONCE].token_len &&
1132                                    wsi->ietf_spec_revision == 4) ||
1133                 (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
1134                                                  wsi->c_protocol != NULL)) {
1135                  debug("libwebsocket_client_handshake "
1136                                         "missing required header(s)\n");
1137                 pkt[len] = '\0';
1138                 debug("%s", pkt);
1139                 goto bail3;
1140         }
1141
1142         /*
1143          * Everything seems to be there, now take a closer look at what
1144          * is in each header
1145          */
1146
1147         strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
1148         if (strncmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, "101", 3)) {
1149                 fprintf(stderr, "libwebsocket_client_handshake "
1150                                 "server sent bad HTTP response '%s'\n",
1151                                  wsi->utf8_token[WSI_TOKEN_HTTP].token);
1152                 goto bail3;
1153         }
1154
1155         strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
1156         if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
1157                                                          "websocket")) {
1158                 fprintf(stderr, "libwebsocket_client_handshake server "
1159                                 "sent bad Upgrade header '%s'\n",
1160                                   wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
1161                 goto bail3;
1162         }
1163
1164         strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
1165         if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
1166                                                            "upgrade")) {
1167                 fprintf(stderr, "libwebsocket_client_handshake server "
1168                                 "sent bad Connection hdr '%s'\n",
1169                            wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
1170                 goto bail3;
1171         }
1172
1173 select_protocol:
1174         pc = wsi->c_protocol;
1175         if (pc == NULL)
1176                 fprintf(stderr, "lws_client_interpret_server_handshake: NULL c_protocol\n");
1177         else
1178                 debug("lws_client_interpret_server_handshake: cPprotocol='%s'\n", pc);
1179
1180         /*
1181          * confirm the protocol the server wants to talk was in the list
1182          * of protocols we offered
1183          */
1184
1185         if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
1186
1187                 fprintf(stderr, "lws_client_interpret_server_handshake WSI_TOKEN_PROTOCOL is null\n");
1188                 /*
1189                  * no protocol name to work from,
1190                  * default to first protocol
1191                  */
1192                 wsi->protocol = &context->protocols[0];
1193
1194                 free(wsi->c_protocol);
1195
1196                 goto check_accept;
1197         }
1198
1199         while (*pc && !okay) {
1200                 if ((!strncmp(pc,
1201                         wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
1202                    wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
1203          (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
1204            pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
1205                         okay = 1;
1206                         continue;
1207                 }
1208                 while (*pc && *pc != ',')
1209                         pc++;
1210                 while (*pc && *pc != ' ')
1211                         pc++;
1212         }
1213
1214         /* done with him now */
1215
1216         if (wsi->c_protocol)
1217                 free(wsi->c_protocol);
1218
1219
1220         if (!okay) {
1221                 fprintf(stderr, "libwebsocket_client_handshake server "
1222                                         "sent bad protocol '%s'\n",
1223                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
1224                 goto bail2;
1225         }
1226
1227         /*
1228          * identify the selected protocol struct and set it
1229          */
1230         n = 0;
1231         wsi->protocol = NULL;
1232         while (context->protocols[n].callback) {
1233                 if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
1234                                            context->protocols[n].name) == 0)
1235                         wsi->protocol = &context->protocols[n];
1236                 n++;
1237         }
1238
1239         if (wsi->protocol == NULL) {
1240                 fprintf(stderr, "libwebsocket_client_handshake server "
1241                                 "requested protocol '%s', which we "
1242                                 "said we supported but we don't!\n",
1243                                  wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
1244                 goto bail2;
1245         }
1246
1247
1248         /* instantiate the accepted extensions */
1249
1250         if (!wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token_len) {
1251                 debug("no client extenstions allowed by server \n");
1252                 goto check_accept;
1253         }
1254
1255         /*
1256          * break down the list of server accepted extensions
1257          * and go through matching them or identifying bogons
1258          */
1259
1260         c = wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token;
1261         n = 0;
1262         while (more) {
1263
1264                 if (*c && (*c != ',' && *c != ' ' && *c != '\t')) {
1265                         ext_name[n] = *c++;
1266                         if (n < sizeof(ext_name) - 1)
1267                                 n++;
1268                         continue;
1269                 }
1270                 ext_name[n] = '\0';
1271                 if (!*c)
1272                         more = 0;
1273                 else {
1274                         c++;
1275                         if (!n)
1276                                 continue;
1277                 }
1278
1279                 /* check we actually support it */
1280
1281                 debug("checking client ext %s\n", ext_name);
1282
1283                 n = 0;
1284                 ext = wsi->protocol->owning_server->extensions;
1285                 while (ext && ext->callback) {
1286
1287                         if (strcmp(ext_name, ext->name)) {
1288                                 ext++;
1289                                 continue;
1290                         }
1291
1292                         n = 1;
1293
1294                         debug("instantiating client ext %s\n", ext_name);
1295
1296                         /* instantiate the extension on this conn */
1297
1298                         wsi->active_extensions_user[
1299                                 wsi->count_active_extensions] =
1300                                          malloc(ext->per_session_data_size);
1301                         memset(wsi->active_extensions_user[
1302                                 wsi->count_active_extensions], 0,
1303                                                     ext->per_session_data_size);
1304                         wsi->active_extensions[
1305                                   wsi->count_active_extensions] = ext;
1306
1307                         /* allow him to construct his context */
1308
1309                         ext->callback(wsi->protocol->owning_server,
1310                                 ext, wsi,
1311                                    LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
1312                                         wsi->active_extensions_user[
1313                                          wsi->count_active_extensions],
1314                                                                    NULL, 0);
1315
1316                         wsi->count_active_extensions++;
1317
1318                         ext++;
1319                 }
1320
1321                 if (n == 0) {
1322                         fprintf(stderr, "Server said we should use"
1323                                   "an unknown extension '%s'!\n", ext_name);
1324                         goto bail2;
1325                 }
1326
1327                 n = 0;
1328         }
1329
1330
1331 check_accept:
1332
1333         if (wsi->ietf_spec_revision == 0) {
1334
1335                 if (memcmp(wsi->initial_handshake_hash_base64,
1336                           wsi->utf8_token[WSI_TOKEN_CHALLENGE].token, 16)) {
1337                         fprintf(stderr, "libwebsocket_client_handshake "
1338                                            "failed 00 challenge compare\n");
1339                                 pkt[len] = '\0';
1340                                 fprintf(stderr, "%s", pkt);
1341                                 goto bail2;
1342                 }
1343
1344                 goto accept_ok;
1345         }
1346
1347         /*
1348          * Confirm his accept token is the one we precomputed
1349          */
1350
1351         if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1352                                   wsi->initial_handshake_hash_base64)) {
1353                 fprintf(stderr, "libwebsocket_client_handshake server "
1354                         "sent bad ACCEPT '%s' vs computed '%s'\n",
1355                         wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1356                                         wsi->initial_handshake_hash_base64);
1357                 goto bail2;
1358         }
1359
1360         if (wsi->ietf_spec_revision == 4) {
1361                 /*
1362                  * Calculate the 04 masking key to use when
1363                  * sending data to server
1364                  */
1365
1366                 strcpy((char *)buf, wsi->key_b64);
1367                 p = (char *)buf + strlen(wsi->key_b64);
1368                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1369                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1370                 strcpy(p, magic_websocket_04_masking_guid);
1371                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1372         }
1373         accept_ok:
1374
1375         /* allocate the per-connection user memory (if any) */
1376         if (wsi->protocol->per_session_data_size && !libwebsocket_ensure_user_space(wsi))
1377           goto bail2;
1378
1379         /* clear his proxy connection timeout */
1380
1381         libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1382
1383         /* mark him as being alive */
1384
1385         wsi->state = WSI_STATE_ESTABLISHED;
1386         wsi->mode = LWS_CONNMODE_WS_CLIENT;
1387
1388         fprintf(stderr, "handshake OK for protocol %s\n",
1389                                                    wsi->protocol->name);
1390
1391         /* call him back to inform him he is up */
1392
1393         wsi->protocol->callback(context, wsi,
1394                          LWS_CALLBACK_CLIENT_ESTABLISHED,
1395                          wsi->user_space,
1396                          NULL, 0);
1397
1398         /*
1399          * inform all extensions, not just active ones since they
1400          * already know
1401          */
1402
1403         ext = context->extensions;
1404
1405         while (ext && ext->callback) {
1406                 v = NULL;
1407                 for (n = 0; n < wsi->count_active_extensions; n++)
1408                         if (wsi->active_extensions[n] == ext)
1409                                 v = wsi->active_extensions_user[n];
1410
1411                 ext->callback(context, ext, wsi,
1412                           LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED, v, NULL, 0);
1413                 ext++;
1414         }
1415
1416         return 0;
1417
1418 bail3:
1419         if (wsi->c_protocol)
1420                 free(wsi->c_protocol);
1421
1422 bail2:
1423         libwebsocket_close_and_free_session(context, wsi,
1424                                                  LWS_CLOSE_STATUS_NOSTATUS);
1425         return 1;
1426 }
1427
1428
1429
1430 /**
1431  * libwebsocket_service_fd() - Service polled socket with something waiting
1432  * @context:    Websocket context
1433  * @pollfd:     The pollfd entry describing the socket fd and which events
1434  *              happened.
1435  *
1436  *      This function closes any active connections and then frees the
1437  *      context.  After calling this, any further use of the context is
1438  *      undefined.
1439  */
1440
1441 int
1442 libwebsocket_service_fd(struct libwebsocket_context *context,
1443                                                           struct pollfd *pollfd)
1444 {
1445         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 + MAX_BROADCAST_PAYLOAD +
1446                                                   LWS_SEND_BUFFER_POST_PADDING];
1447         struct libwebsocket *wsi;
1448         struct libwebsocket *new_wsi;
1449         int n;
1450         int m;
1451         size_t len;
1452         int accept_fd;
1453         unsigned int clilen;
1454         struct sockaddr_in cli_addr;
1455         struct timeval tv;
1456         char pkt[1024];
1457         char *p = &pkt[0];
1458         int more = 1;
1459         struct lws_tokens eff_buf;
1460         int opt = 1;
1461
1462 #ifdef LWS_OPENSSL_SUPPORT
1463         char ssl_err_buf[512];
1464 #endif
1465         /*
1466          * you can call us with pollfd = NULL to just allow the once-per-second
1467          * global timeout checks; if less than a second since the last check
1468          * it returns immediately then.
1469          */
1470
1471         gettimeofday(&tv, NULL);
1472
1473         if (context->last_timeout_check_s != tv.tv_sec) {
1474                 context->last_timeout_check_s = tv.tv_sec;
1475
1476                 /* global timeout check once per second */
1477
1478                 for (n = 0; n < context->fds_count; n++) {
1479                         wsi = wsi_from_fd(context, context->fds[n].fd);
1480
1481                         libwebsocket_service_timeout_check(context, wsi,
1482                                                                      tv.tv_sec);
1483                 }
1484         }
1485
1486         /* just here for timeout management? */
1487
1488         if (pollfd == NULL)
1489                 return 0;
1490
1491         /* no, here to service a socket descriptor */
1492
1493         wsi = wsi_from_fd(context, pollfd->fd);
1494
1495         if (wsi == NULL)
1496                 return 1;
1497
1498         switch (wsi->mode) {
1499         case LWS_CONNMODE_SERVER_LISTENER:
1500
1501                 /* pollin means a client has connected to us then */
1502
1503                 if (!pollfd->revents & POLLIN)
1504                         break;
1505
1506                 if (context->fds_count >= MAX_CLIENTS) {
1507                         fprintf(stderr, "too busy to accept new client\n");
1508                         break;
1509                 }
1510
1511                 /* listen socket got an unencrypted connection... */
1512
1513                 clilen = sizeof(cli_addr);
1514                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
1515                                                                        &clilen);
1516                 if (accept_fd < 0) {
1517                         fprintf(stderr, "ERROR on accept");
1518                         break;
1519                 }
1520
1521                 /* Disable Nagle */
1522                 opt = 1;
1523         setsockopt(accept_fd, IPPROTO_TCP, TCP_NODELAY, (const void *)&opt,
1524                                 sizeof(opt));
1525
1526                 /*
1527                  * look at who we connected to and give user code a chance
1528                  * to reject based on client IP.  There's no protocol selected
1529                  * yet so we issue this to protocols[0]
1530                  */
1531
1532                 if ((context->protocols[0].callback)(context, wsi,
1533                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
1534                                              (void*)(long)accept_fd, NULL, 0)) {
1535                         debug("Callback denied network connection\n");
1536 #ifdef WIN32
1537                         closesocket(accept_fd);
1538 #else
1539                         close(accept_fd);
1540 #endif
1541                         break;
1542                 }
1543
1544                 /* accepting connection to main listener */
1545
1546                 new_wsi = libwebsocket_create_new_server_wsi(context);
1547                 if (new_wsi == NULL)
1548                         break;
1549
1550                 new_wsi->sock = accept_fd;
1551
1552
1553 #ifdef LWS_OPENSSL_SUPPORT
1554                 new_wsi->ssl = NULL;
1555
1556                 if (context->use_ssl) {
1557
1558                         new_wsi->ssl = SSL_new(context->ssl_ctx);
1559                         if (new_wsi->ssl == NULL) {
1560                                 fprintf(stderr, "SSL_new failed: %s\n",
1561                                     ERR_error_string(SSL_get_error(
1562                                     new_wsi->ssl, 0), NULL));
1563                                     libwebsockets_decode_ssl_error();
1564                                 free(new_wsi);
1565                                 break;
1566                         }
1567
1568                         SSL_set_fd(new_wsi->ssl, accept_fd);
1569
1570                         n = SSL_accept(new_wsi->ssl);
1571                         if (n != 1) {
1572                                 /*
1573                                  * browsers seem to probe with various
1574                                  * ssl params which fail then retry
1575                                  * and succeed
1576                                  */
1577                                 debug("SSL_accept failed skt %u: %s\n",
1578                                       pollfd->fd,
1579                                       ERR_error_string(SSL_get_error(
1580                                       new_wsi->ssl, n), NULL));
1581                                 SSL_free(
1582                                        new_wsi->ssl);
1583                                 free(new_wsi);
1584                                 break;
1585                         }
1586                         
1587                         debug("accepted new SSL conn  "
1588                               "port %u on fd=%d SSL ver %s\n",
1589                                 ntohs(cli_addr.sin_port), accept_fd,
1590                                   SSL_get_version(new_wsi->ssl));
1591
1592                 } else
1593 #endif
1594                         debug("accepted new conn  port %u on fd=%d\n",
1595                                           ntohs(cli_addr.sin_port), accept_fd);
1596
1597                 insert_wsi(context, new_wsi);
1598
1599                 /*
1600                  * make sure NO events are seen yet on this new socket
1601                  * (otherwise we inherit old fds[client].revents from
1602                  * previous socket there and die mysteriously! )
1603                  */
1604                 context->fds[context->fds_count].revents = 0;
1605
1606                 context->fds[context->fds_count].events = POLLIN;
1607                 context->fds[context->fds_count++].fd = accept_fd;
1608
1609                 /* external POLL support via protocol 0 */
1610                 context->protocols[0].callback(context, new_wsi,
1611                         LWS_CALLBACK_ADD_POLL_FD,
1612                         (void *)(long)accept_fd, NULL, POLLIN);
1613
1614                 break;
1615
1616         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
1617
1618                 /* as we are listening, POLLIN means accept() is needed */
1619         
1620                 if (!pollfd->revents & POLLIN)
1621                         break;
1622
1623                 /* listen socket got an unencrypted connection... */
1624
1625                 clilen = sizeof(cli_addr);
1626                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
1627                                                                        &clilen);
1628                 if (accept_fd < 0) {
1629                         fprintf(stderr, "ERROR on accept");
1630                         break;
1631                 }
1632
1633                 if (context->fds_count >= MAX_CLIENTS) {
1634                         fprintf(stderr, "too busy to accept new broadcast "
1635                                                               "proxy client\n");
1636 #ifdef WIN32
1637                         closesocket(accept_fd);
1638 #else
1639                         close(accept_fd);
1640 #endif
1641                         break;
1642                 }
1643
1644                 /* create a dummy wsi for the connection and add it */
1645
1646                 new_wsi = malloc(sizeof(struct libwebsocket));
1647                 memset(new_wsi, 0, sizeof (struct libwebsocket));
1648                 new_wsi->sock = accept_fd;
1649                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
1650                 new_wsi->state = WSI_STATE_ESTABLISHED;
1651                 new_wsi->count_active_extensions = 0;
1652                 /* note which protocol we are proxying */
1653                 new_wsi->protocol_index_for_broadcast_proxy =
1654                                         wsi->protocol_index_for_broadcast_proxy;
1655                 insert_wsi(context, new_wsi);
1656
1657                 /* add connected socket to internal poll array */
1658
1659                 context->fds[context->fds_count].revents = 0;
1660                 context->fds[context->fds_count].events = POLLIN;
1661                 context->fds[context->fds_count++].fd = accept_fd;
1662
1663                 /* external POLL support via protocol 0 */
1664                 context->protocols[0].callback(context, new_wsi,
1665                         LWS_CALLBACK_ADD_POLL_FD,
1666                         (void *)(long)accept_fd, NULL, POLLIN);
1667
1668                 break;
1669
1670         case LWS_CONNMODE_BROADCAST_PROXY:
1671
1672                 /* handle session socket closed */
1673
1674                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1675
1676                         debug("Session Socket %p (fd=%d) dead\n",
1677                                 (void *)wsi, pollfd->fd);
1678
1679                         libwebsocket_close_and_free_session(context, wsi,
1680                                                        LWS_CLOSE_STATUS_NORMAL);
1681                         return 1;
1682                 }
1683
1684                 /*
1685                  * either extension code with stuff to spill, or the user code,
1686                  * requested a callback when it was OK to write
1687                  */
1688
1689                 if (pollfd->revents & POLLOUT)
1690                         if (lws_handle_POLLOUT_event(context, wsi, pollfd) < 0) {
1691                                 libwebsocket_close_and_free_session(context, wsi,
1692                                                        LWS_CLOSE_STATUS_NORMAL);
1693                                 return 1;
1694                         }
1695
1696                 /* any incoming data ready? */
1697
1698                 if (!(pollfd->revents & POLLIN))
1699                         break;
1700
1701                 /* get the issued broadcast payload from the socket */
1702
1703                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
1704                                                          MAX_BROADCAST_PAYLOAD);
1705                 if (len < 0) {
1706                         fprintf(stderr, "Error reading broadcast payload\n");
1707                         break;
1708                 }
1709
1710                 /* broadcast it to all guys with this protocol index */
1711
1712                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1713
1714                         for (m = 0; m < context->fd_hashtable[n].length; m++) {
1715
1716                                 new_wsi = context->fd_hashtable[n].wsi[m];
1717
1718                                 /* only to clients we are serving to */
1719
1720                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
1721                                         continue;
1722
1723                                 /*
1724                                  * never broadcast to non-established
1725                                  * connection
1726                                  */
1727
1728                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
1729                                         continue;
1730
1731                                 /*
1732                                  * only broadcast to connections using
1733                                  * the requested protocol
1734                                  */
1735
1736                                 if (new_wsi->protocol->protocol_index !=
1737                                         wsi->protocol_index_for_broadcast_proxy)
1738                                         continue;
1739
1740                                 /* broadcast it to this connection */
1741
1742                                 new_wsi->protocol->callback(context, new_wsi,
1743                                         LWS_CALLBACK_BROADCAST,
1744                                         new_wsi->user_space,
1745                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
1746                         }
1747                 }
1748                 break;
1749
1750         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
1751
1752                 /* handle proxy hung up on us */
1753
1754                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1755
1756                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
1757                                 (void *)wsi, pollfd->fd);
1758
1759                         libwebsocket_close_and_free_session(context, wsi,
1760                                                      LWS_CLOSE_STATUS_NOSTATUS);
1761                         return 1;
1762                 }
1763
1764                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
1765                 if (n < 0) {
1766                         libwebsocket_close_and_free_session(context, wsi,
1767                                                      LWS_CLOSE_STATUS_NOSTATUS);
1768                         fprintf(stderr, "ERROR reading from proxy socket\n");
1769                         return 1;
1770                 }
1771
1772                 pkt[13] = '\0';
1773                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
1774                         libwebsocket_close_and_free_session(context, wsi,
1775                                                      LWS_CLOSE_STATUS_NOSTATUS);
1776                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
1777                         return 1;
1778                 }
1779
1780                 /* clear his proxy connection timeout */
1781
1782                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1783
1784                 /* fallthru */
1785
1786         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
1787
1788         #ifdef LWS_OPENSSL_SUPPORT
1789                 if (wsi->use_ssl) {
1790
1791                         wsi->ssl = SSL_new(context->ssl_client_ctx);
1792                         wsi->client_bio = BIO_new_socket(wsi->sock,
1793                                                                    BIO_NOCLOSE);
1794                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
1795
1796                         SSL_set_ex_data(wsi->ssl,
1797                                         openssl_websocket_private_data_index,
1798                                                                        context);
1799
1800                         if (SSL_connect(wsi->ssl) <= 0) {
1801                                 fprintf(stderr, "SSL connect error %s\n",
1802                                         ERR_error_string(ERR_get_error(),
1803                                                                   ssl_err_buf));
1804                                 libwebsocket_close_and_free_session(context, wsi,
1805                                                      LWS_CLOSE_STATUS_NOSTATUS);
1806                                 return 1;
1807                         }
1808
1809                         n = SSL_get_verify_result(wsi->ssl);
1810                         if ((n != X509_V_OK) && (
1811                                 n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
1812                                                            wsi->use_ssl != 2)) {
1813
1814                                 fprintf(stderr, "server's cert didn't "
1815                                                            "look good %d\n", n);
1816                                 libwebsocket_close_and_free_session(context,
1817                                                 wsi, LWS_CLOSE_STATUS_NOSTATUS);
1818                                 return 1;
1819                         }
1820                 } else {
1821                         wsi->ssl = NULL;
1822         #endif
1823
1824
1825         #ifdef LWS_OPENSSL_SUPPORT
1826                 }
1827         #endif
1828
1829                 p = libwebsockets_generate_client_handshake(context, wsi, p);
1830                 if (p ==NULL)
1831                         return 1;
1832
1833                 /* send our request to the server */
1834
1835         #ifdef LWS_OPENSSL_SUPPORT
1836                 if (wsi->use_ssl)
1837                         n = SSL_write(wsi->ssl, pkt, p - pkt);
1838                 else
1839         #endif
1840                         n = send(wsi->sock, pkt, p - pkt, 0);
1841
1842                 if (n < 0) {
1843                         fprintf(stderr, "ERROR writing to client socket\n");
1844                         libwebsocket_close_and_free_session(context, wsi,
1845                                                      LWS_CLOSE_STATUS_NOSTATUS);
1846                         return 1;
1847                 }
1848
1849                 wsi->parser_state = WSI_TOKEN_NAME_PART;
1850                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
1851                 libwebsocket_set_timeout(wsi,
1852                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, 5);
1853
1854                 break;
1855
1856         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
1857
1858                 /* handle server hung up on us */
1859
1860                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1861
1862                         fprintf(stderr, "Server connection %p (fd=%d) dead\n",
1863                                 (void *)wsi, pollfd->fd);
1864
1865                         goto bail3;
1866                 }
1867
1868
1869                 /* interpret the server response */
1870
1871                 /*
1872                  *  HTTP/1.1 101 Switching Protocols
1873                  *  Upgrade: websocket
1874                  *  Connection: Upgrade
1875                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
1876                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
1877                  *  Sec-WebSocket-Protocol: chat
1878                  */
1879
1880         #ifdef LWS_OPENSSL_SUPPORT
1881                 if (wsi->use_ssl)
1882                         len = SSL_read(wsi->ssl, pkt, sizeof pkt);
1883                 else
1884         #endif
1885                         len = recv(wsi->sock, pkt, sizeof pkt, 0);
1886
1887                 if (len < 0) {
1888                         fprintf(stderr,
1889                                   "libwebsocket_client_handshake read error\n");
1890                         goto bail3;
1891                 }
1892
1893                 p = pkt;
1894                 for (n = 0; n < len; n++)
1895                         libwebsocket_parse(wsi, *p++);
1896
1897                 /*
1898                  * may be coming in multiple packets, there is a 5-second
1899                  * libwebsocket timeout still active here too, so if parsing did
1900                  * not complete just wait for next packet coming in this state
1901                  */
1902
1903                 if (wsi->parser_state != WSI_PARSING_COMPLETE)
1904                         break;
1905
1906                 return lws_client_interpret_server_handshake(context, wsi);
1907
1908 bail3:
1909                 if (wsi->c_protocol)
1910                         free(wsi->c_protocol);
1911                 libwebsocket_close_and_free_session(context, wsi,
1912                                                                  LWS_CLOSE_STATUS_NOSTATUS);
1913                 return 1;
1914
1915         case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
1916                 fprintf(stderr, "LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT\n");
1917                 break;
1918
1919         case LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD:
1920                 fprintf(stderr, "LWS_CONNMODE_WS_CLIENT_PENDING_CANDIDATE_CHILD\n");
1921                 break;
1922
1923
1924         case LWS_CONNMODE_WS_SERVING:
1925         case LWS_CONNMODE_WS_CLIENT:
1926
1927                 /* handle session socket closed */
1928
1929                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1930
1931                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1932                                 (void *)wsi, pollfd->fd);
1933
1934                         libwebsocket_close_and_free_session(context, wsi,
1935                                                      LWS_CLOSE_STATUS_NOSTATUS);
1936                         return 1;
1937                 }
1938
1939                 /* the guy requested a callback when it was OK to write */
1940
1941                 if ((pollfd->revents & POLLOUT) &&
1942                                             wsi->state == WSI_STATE_ESTABLISHED)
1943                         if (lws_handle_POLLOUT_event(context, wsi,
1944                                                                   pollfd) < 0) {
1945                                 libwebsocket_close_and_free_session(
1946                                          context, wsi, LWS_CLOSE_STATUS_NORMAL);
1947                                 return 1;
1948                         }
1949
1950
1951                 /* any incoming data ready? */
1952
1953                 if (!(pollfd->revents & POLLIN))
1954                         break;
1955
1956 #ifdef LWS_OPENSSL_SUPPORT
1957                 if (wsi->ssl)
1958                         eff_buf.token_len = SSL_read(wsi->ssl, buf, sizeof buf);
1959                 else
1960 #endif
1961                         eff_buf.token_len =
1962                                            recv(pollfd->fd, buf, sizeof buf, 0);
1963
1964                 if (eff_buf.token_len < 0) {
1965                         fprintf(stderr, "Socket read returned %d\n",
1966                                                             eff_buf.token_len);
1967                         break;
1968                 }
1969                 if (!eff_buf.token_len) {
1970                         libwebsocket_close_and_free_session(context, wsi,
1971                                                      LWS_CLOSE_STATUS_NOSTATUS);
1972                         return 1;
1973                 }
1974
1975                 /*
1976                  * give any active extensions a chance to munge the buffer
1977                  * before parse.  We pass in a pointer to an lws_tokens struct
1978                  * prepared with the default buffer and content length that's in
1979                  * there.  Rather than rewrite the default buffer, extensions
1980                  * that expect to grow the buffer can adapt .token to
1981                  * point to their own per-connection buffer in the extension
1982                  * user allocation.  By default with no extensions or no
1983                  * extension callback handling, just the normal input buffer is
1984                  * used then so it is efficient.
1985                  */
1986
1987                 eff_buf.token = (char *)buf;
1988
1989                 more = 1;
1990                 while (more) {
1991
1992                         more = 0;
1993
1994                         for (n = 0; n < wsi->count_active_extensions; n++) {
1995                                 m = wsi->active_extensions[n]->callback(context,
1996                                         wsi->active_extensions[n], wsi,
1997                                         LWS_EXT_CALLBACK_PACKET_RX_PREPARSE,
1998                                         wsi->active_extensions_user[n],
1999                                                                    &eff_buf, 0);
2000                                 if (m < 0) {
2001                                         fprintf(stderr, "Extension reports fatal error\n");
2002                                         libwebsocket_close_and_free_session(context, wsi,
2003                                                              LWS_CLOSE_STATUS_NOSTATUS);
2004                                         return 1;
2005                                 }
2006                                 if (m)
2007                                         more = 1;
2008                         }
2009
2010                         /* service incoming data */
2011
2012                         if (eff_buf.token_len) {
2013                                 n = libwebsocket_read(context, wsi,
2014                                      (unsigned char *)eff_buf.token, eff_buf.token_len);
2015                                 if (n < 0)
2016                                         /* we closed wsi */
2017                                         return 1;
2018                         }
2019
2020                         eff_buf.token = NULL;
2021                         eff_buf.token_len = 0;
2022                 }
2023                 break;
2024         }
2025
2026         return 0;
2027 }
2028
2029
2030 /**
2031  * libwebsocket_context_destroy() - Destroy the websocket context
2032  * @context:    Websocket context
2033  *
2034  *      This function closes any active connections and then frees the
2035  *      context.  After calling this, any further use of the context is
2036  *      undefined.
2037  */
2038 void
2039 libwebsocket_context_destroy(struct libwebsocket_context *context)
2040 {
2041         int n;
2042         int m;
2043         struct libwebsocket *wsi;
2044         struct libwebsocket_extension *ext;
2045
2046         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
2047                 for (m = 0; m < context->fd_hashtable[n].length; m++) {
2048                         wsi = context->fd_hashtable[n].wsi[m];
2049                         libwebsocket_close_and_free_session(context, wsi,
2050                                                     LWS_CLOSE_STATUS_GOINGAWAY);
2051                 }
2052
2053         /*
2054          * give all extensions a chance to clean up any per-context
2055          * allocations they might have made
2056          */
2057
2058         ext = context->extensions;
2059         m = LWS_EXT_CALLBACK_CLIENT_CONTEXT_DESTRUCT;
2060         if (context->listen_port)
2061                 m = LWS_EXT_CALLBACK_SERVER_CONTEXT_DESTRUCT;
2062         while (ext->callback) {
2063                 ext->callback(context, ext, NULL, m, NULL, NULL, 0);
2064                 ext++;
2065         }
2066
2067 #ifdef WIN32
2068 #else
2069         close(context->fd_random);
2070 #endif
2071
2072 #ifdef LWS_OPENSSL_SUPPORT
2073         if (context->ssl_ctx)
2074                 SSL_CTX_free(context->ssl_ctx);
2075         if (context->ssl_client_ctx)
2076                 SSL_CTX_free(context->ssl_client_ctx);
2077 #endif
2078
2079         free(context);
2080
2081 #ifdef WIN32
2082         WSACleanup();
2083 #endif
2084 }
2085
2086 /**
2087  * libwebsocket_service() - Service any pending websocket activity
2088  * @context:    Websocket context
2089  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
2090  *              service otherwise block and service immediately, returning
2091  *              after the timeout if nothing needed service.
2092  *
2093  *      This function deals with any pending websocket traffic, for three
2094  *      kinds of event.  It handles these events on both server and client
2095  *      types of connection the same.
2096  *
2097  *      1) Accept new connections to our context's server
2098  *
2099  *      2) Perform pending broadcast writes initiated from other forked
2100  *         processes (effectively serializing asynchronous broadcasts)
2101  *
2102  *      3) Call the receive callback for incoming frame data received by
2103  *          server or client connections.
2104  *
2105  *      You need to call this service function periodically to all the above
2106  *      functions to happen; if your application is single-threaded you can
2107  *      just call it in your main event loop.
2108  *
2109  *      Alternatively you can fork a new process that asynchronously handles
2110  *      calling this service in a loop.  In that case you are happy if this
2111  *      call blocks your thread until it needs to take care of something and
2112  *      would call it with a large nonzero timeout.  Your loop then takes no
2113  *      CPU while there is nothing happening.
2114  *
2115  *      If you are calling it in a single-threaded app, you don't want it to
2116  *      wait around blocking other things in your loop from happening, so you
2117  *      would call it with a timeout_ms of 0, so it returns immediately if
2118  *      nothing is pending, or as soon as it services whatever was pending.
2119  */
2120
2121
2122 int
2123 libwebsocket_service(struct libwebsocket_context *context, int timeout_ms)
2124 {
2125         int n;
2126
2127         /* stay dead once we are dead */
2128
2129         if (context == NULL)
2130                 return 1;
2131
2132         /* wait for something to need service */
2133
2134         n = poll(context->fds, context->fds_count, timeout_ms);
2135         if (n == 0) /* poll timeout */
2136                 return 0;
2137
2138         if (n < 0) {
2139                 /*
2140                 fprintf(stderr, "Listen Socket dead\n");
2141                 */
2142                 return 1;
2143         }
2144
2145         /* handle accept on listening socket? */
2146
2147         for (n = 0; n < context->fds_count; n++)
2148                 if (context->fds[n].revents)
2149                         libwebsocket_service_fd(context, &context->fds[n]);
2150
2151         return 0;
2152 }
2153
2154 int
2155 lws_any_extension_handled(struct libwebsocket_context *context,
2156                                                        struct libwebsocket *wsi,
2157                                                        enum libwebsocket_extension_callback_reasons r,
2158                                                        void *v, size_t len)
2159 {
2160         int n;
2161         int handled = 0;
2162
2163         /* maybe an extension will take care of it for us */
2164
2165         for (n = 0; n < wsi->count_active_extensions && !handled; n++) {
2166                 if (!wsi->active_extensions[n]->callback)
2167                         continue;
2168
2169                 handled |= wsi->active_extensions[n]->callback(context,
2170                         wsi->active_extensions[n], wsi,
2171                         r, wsi->active_extensions_user[n], v, len);
2172         }
2173
2174         return handled;
2175 }
2176
2177
2178 void *
2179 lws_get_extension_user_matching_ext(struct libwebsocket *wsi,
2180                                                         struct libwebsocket_extension * ext)
2181 {
2182         int n = 0;
2183
2184         if (wsi == NULL)
2185                 return NULL;
2186
2187         while (n < wsi->count_active_extensions) {
2188                 if (wsi->active_extensions[n] != ext) {
2189                         n++;
2190                         continue;
2191                 }
2192                 return wsi->active_extensions_user[n];
2193         }
2194
2195         return NULL;
2196 }
2197
2198 /**
2199  * libwebsocket_callback_on_writable() - Request a callback when this socket
2200  *                                       becomes able to be written to without
2201  *                                       blocking
2202  *
2203  * @context:    libwebsockets context
2204  * @wsi:        Websocket connection instance to get callback for
2205  */
2206
2207 int
2208 libwebsocket_callback_on_writable(struct libwebsocket_context *context,
2209                                                        struct libwebsocket *wsi)
2210 {
2211         int n;
2212         int handled = 0;
2213
2214         /* maybe an extension will take care of it for us */
2215
2216         for (n = 0; n < wsi->count_active_extensions; n++) {
2217                 if (!wsi->active_extensions[n]->callback)
2218                         continue;
2219
2220                 handled |= wsi->active_extensions[n]->callback(context,
2221                         wsi->active_extensions[n], wsi,
2222                         LWS_EXT_CALLBACK_REQUEST_ON_WRITEABLE,
2223                                        wsi->active_extensions_user[n], NULL, 0);
2224         }
2225
2226         if (handled)
2227                 return 1;
2228
2229         for (n = 0; n < context->fds_count; n++)
2230                 if (context->fds[n].fd == wsi->sock) {
2231                         context->fds[n].events |= POLLOUT;
2232                         n = context->fds_count + 1;
2233                 }
2234
2235         if (n == context->fds_count)
2236                 fprintf(stderr, "libwebsocket_callback_on_writable: failed to find socket %d\n", wsi->sock);
2237
2238         /* external POLL support via protocol 0 */
2239         context->protocols[0].callback(context, wsi,
2240                 LWS_CALLBACK_SET_MODE_POLL_FD,
2241                 (void *)(long)wsi->sock, NULL, POLLOUT);
2242
2243         return 1;
2244 }
2245
2246 /**
2247  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
2248  *                      all connections using the given protocol when it
2249  *                      becomes possible to write to each socket without
2250  *                      blocking in turn.
2251  *
2252  * @protocol:   Protocol whose connections will get callbacks
2253  */
2254
2255 int
2256 libwebsocket_callback_on_writable_all_protocol(
2257                                   const struct libwebsocket_protocols *protocol)
2258 {
2259         struct libwebsocket_context *context = protocol->owning_server;
2260         int n;
2261         int m;
2262         struct libwebsocket *wsi;
2263
2264         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
2265
2266                 for (m = 0; m < context->fd_hashtable[n].length; m++) {
2267
2268                         wsi = context->fd_hashtable[n].wsi[m];
2269
2270                         if (wsi->protocol == protocol)
2271                                 libwebsocket_callback_on_writable(context, wsi);
2272                 }
2273         }
2274
2275         return 0;
2276 }
2277
2278 /**
2279  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
2280  *
2281  * You will not need this unless you are doing something special
2282  *
2283  * @wsi:        Websocket connection instance
2284  * @reason:     timeout reason
2285  * @secs:       how many seconds
2286  */
2287
2288 void
2289 libwebsocket_set_timeout(struct libwebsocket *wsi,
2290                                           enum pending_timeout reason, int secs)
2291 {
2292         struct timeval tv;
2293
2294         gettimeofday(&tv, NULL);
2295
2296         wsi->pending_timeout_limit = tv.tv_sec + secs;
2297         wsi->pending_timeout = reason;
2298 }
2299
2300
2301 /**
2302  * libwebsocket_get_socket_fd() - returns the socket file descriptor
2303  *
2304  * You will not need this unless you are doing something special
2305  *
2306  * @wsi:        Websocket connection instance
2307  */
2308
2309 int
2310 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
2311 {
2312         return wsi->sock;
2313 }
2314
2315 /**
2316  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
2317  *                              receieved packets.
2318  *
2319  * If the output side of a server process becomes choked, this allows flow
2320  * control for the input side.
2321  *
2322  * @wsi:        Websocket connection instance to get callback for
2323  * @enable:     0 = disable read servicing for this connection, 1 = enable
2324  */
2325
2326 int
2327 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
2328 {
2329         struct libwebsocket_context *context = wsi->protocol->owning_server;
2330         int n;
2331
2332         for (n = 0; n < context->fds_count; n++)
2333                 if (context->fds[n].fd == wsi->sock) {
2334                         if (enable)
2335                                 context->fds[n].events |= POLLIN;
2336                         else
2337                                 context->fds[n].events &= ~POLLIN;
2338
2339                         return 0;
2340                 }
2341
2342         if (enable)
2343                 /* external POLL support via protocol 0 */
2344                 context->protocols[0].callback(context, wsi,
2345                         LWS_CALLBACK_SET_MODE_POLL_FD,
2346                         (void *)(long)wsi->sock, NULL, POLLIN);
2347         else
2348                 /* external POLL support via protocol 0 */
2349                 context->protocols[0].callback(context, wsi,
2350                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
2351                         (void *)(long)wsi->sock, NULL, POLLIN);
2352
2353 #if 0
2354         fprintf(stderr, "libwebsocket_rx_flow_control "
2355                                                      "unable to find socket\n");
2356 #endif
2357         return 1;
2358 }
2359
2360 /**
2361  * libwebsocket_canonical_hostname() - returns this host's hostname
2362  *
2363  * This is typically used by client code to fill in the host parameter
2364  * when making a client connection.  You can only call it after the context
2365  * has been created.
2366  *
2367  * @context:    Websocket context
2368  */
2369
2370
2371 extern const char *
2372 libwebsocket_canonical_hostname(struct libwebsocket_context *context)
2373 {
2374         return (const char *)context->canonical_hostname;
2375 }
2376
2377
2378 static void sigpipe_handler(int x)
2379 {
2380 }
2381
2382 #ifdef LWS_OPENSSL_SUPPORT
2383 static int
2384 OpenSSL_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
2385 {
2386
2387         SSL *ssl;
2388         int n;
2389         struct libwebsocket_context *context;
2390
2391         ssl = X509_STORE_CTX_get_ex_data(x509_ctx,
2392                 SSL_get_ex_data_X509_STORE_CTX_idx());
2393
2394         /*
2395          * !!! nasty openssl requires the index to come as a library-scope
2396          * static
2397          */
2398         context = SSL_get_ex_data(ssl, openssl_websocket_private_data_index);
2399         
2400         n = context->protocols[0].callback(NULL, NULL,
2401                 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
2402                                                    x509_ctx, ssl, preverify_ok);
2403
2404         /* convert return code from 0 = OK to 1 = OK */
2405
2406         if (!n)
2407                 n = 1;
2408         else
2409                 n = 0;
2410
2411         return n;
2412 }
2413 #endif
2414
2415
2416 /**
2417  * libwebsocket_create_context() - Create the websocket handler
2418  * @port:       Port to listen on... you can use 0 to suppress listening on
2419  *              any port, that's what you want if you are not running a
2420  *              websocket server at all but just using it as a client
2421  * @interf:  NULL to bind the listen socket to all interfaces, or the
2422  *              interface name, eg, "eth2"
2423  * @protocols:  Array of structures listing supported protocols and a protocol-
2424  *              specific callback for each one.  The list is ended with an
2425  *              entry that has a NULL callback pointer.
2426  *              It's not const because we write the owning_server member
2427  * @extensions: NULL or array of libwebsocket_extension structs listing the
2428  *              extensions this context supports
2429  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
2430  *                      to listen using SSL, set to the filepath to fetch the
2431  *                      server cert from, otherwise NULL for unencrypted
2432  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
2433  *                      else ignored
2434  * @gid:        group id to change to after setting listen socket, or -1.
2435  * @uid:        user id to change to after setting listen socket, or -1.
2436  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
2437  *
2438  *      This function creates the listening socket and takes care
2439  *      of all initialization in one step.
2440  *
2441  *      After initialization, it returns a struct libwebsocket_context * that
2442  *      represents this server.  After calling, user code needs to take care
2443  *      of calling libwebsocket_service() with the context pointer to get the
2444  *      server's sockets serviced.  This can be done in the same process context
2445  *      or a forked process, or another thread,
2446  *
2447  *      The protocol callback functions are called for a handful of events
2448  *      including http requests coming in, websocket connections becoming
2449  *      established, and data arriving; it's also called periodically to allow
2450  *      async transmission.
2451  *
2452  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
2453  *      at that time websocket protocol has not been negotiated.  Other
2454  *      protocols after the first one never see any HTTP callack activity.
2455  *
2456  *      The server created is a simple http server by default; part of the
2457  *      websocket standard is upgrading this http connection to a websocket one.
2458  *
2459  *      This allows the same server to provide files like scripts and favicon /
2460  *      images or whatever over http and dynamic data over websockets all in
2461  *      one place; they're all handled in the user callback.
2462  */
2463
2464 struct libwebsocket_context *
2465 libwebsocket_create_context(int port, const char *interf,
2466                                struct libwebsocket_protocols *protocols,
2467                                struct libwebsocket_extension *extensions,
2468                                const char *ssl_cert_filepath,
2469                                const char *ssl_private_key_filepath,
2470                                int gid, int uid, unsigned int options)
2471 {
2472         int n;
2473         int m;
2474         int sockfd = 0;
2475         int fd;
2476         struct sockaddr_in serv_addr, cli_addr;
2477         int opt = 1;
2478         struct libwebsocket_context *context = NULL;
2479         unsigned int slen;
2480         char *p;
2481         char hostname[1024];
2482         struct hostent *he;
2483         struct libwebsocket *wsi;
2484
2485 #ifdef LWS_OPENSSL_SUPPORT
2486         SSL_METHOD *method;
2487         char ssl_err_buf[512];
2488 #endif
2489
2490 #ifdef _WIN32
2491         {
2492                 WORD wVersionRequested;
2493                 WSADATA wsaData;
2494                 int err;
2495         HMODULE wsdll;
2496
2497                 /* Use the MAKEWORD(lowbyte, highbyte) macro from Windef.h */
2498                 wVersionRequested = MAKEWORD(2, 2);
2499
2500                 err = WSAStartup(wVersionRequested, &wsaData);
2501                 if (err != 0) {
2502                         /* Tell the user that we could not find a usable */
2503                         /* Winsock DLL.                                  */
2504                         fprintf(stderr, "WSAStartup failed with error: %d\n",
2505                                                                            err);
2506                         return NULL;
2507                 }
2508
2509         wsdll = GetModuleHandle("Ws2_32.dll");
2510         if (wsdll)
2511         {
2512             poll = (PFNWSAPOLL)GetProcAddress(wsdll, "WSAPoll");
2513         }
2514
2515         if (!poll)
2516         {
2517             poll = emulated_poll;
2518         }
2519         }
2520 #endif
2521
2522
2523         context = malloc(sizeof(struct libwebsocket_context));
2524         if (!context) {
2525                 fprintf(stderr, "No memory for websocket context\n");
2526                 return NULL;
2527         }
2528         context->protocols = protocols;
2529         context->listen_port = port;
2530         context->http_proxy_port = 0;
2531         context->http_proxy_address[0] = '\0';
2532         context->options = options;
2533         context->fds_count = 0;
2534         context->extensions = extensions;
2535
2536 #ifdef WIN32
2537         context->fd_random = 0;
2538 #else
2539         context->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
2540         if (context->fd_random < 0) {
2541                 fprintf(stderr, "Unable to open random device %s %d\n",
2542                                     SYSTEM_RANDOM_FILEPATH, context->fd_random);
2543                 return NULL;
2544         }
2545 #endif
2546
2547 #ifdef LWS_OPENSSL_SUPPORT
2548         context->use_ssl = 0;
2549         context->ssl_ctx = NULL;
2550         context->ssl_client_ctx = NULL;
2551         openssl_websocket_private_data_index = 0;
2552 #endif
2553         /* find canonical hostname */
2554
2555         hostname[(sizeof hostname) - 1] = '\0';
2556         gethostname(hostname, (sizeof hostname) - 1);
2557         he = gethostbyname(hostname);
2558         if (he) {
2559                 strncpy(context->canonical_hostname, he->h_name,
2560                                         sizeof context->canonical_hostname - 1);
2561                 context->canonical_hostname[
2562                                 sizeof context->canonical_hostname - 1] = '\0';
2563         } else
2564                 strncpy(context->canonical_hostname, hostname,
2565                                         sizeof context->canonical_hostname - 1);
2566
2567         /* split the proxy ads:port if given */
2568
2569         p = getenv("http_proxy");
2570         if (p) {
2571                 strncpy(context->http_proxy_address, p,
2572                                         sizeof context->http_proxy_address - 1);
2573                 context->http_proxy_address[
2574                                  sizeof context->http_proxy_address - 1] = '\0';
2575
2576                 p = strchr(context->http_proxy_address, ':');
2577                 if (p == NULL) {
2578                         fprintf(stderr, "http_proxy needs to be ads:port\n");
2579                         return NULL;
2580                 }
2581                 *p = '\0';
2582                 context->http_proxy_port = atoi(p + 1);
2583
2584                 fprintf(stderr, "Using proxy %s:%u\n",
2585                                 context->http_proxy_address,
2586                                                       context->http_proxy_port);
2587         }
2588
2589         if (port) {
2590
2591 #ifdef LWS_OPENSSL_SUPPORT
2592                 context->use_ssl = ssl_cert_filepath != NULL &&
2593                                                ssl_private_key_filepath != NULL;
2594                 if (context->use_ssl)
2595                         fprintf(stderr, " Compiled with SSL support, "
2596                                                                   "using it\n");
2597                 else
2598                         fprintf(stderr, " Compiled with SSL support, "
2599                                                               "not using it\n");
2600
2601 #else
2602                 if (ssl_cert_filepath != NULL &&
2603                                              ssl_private_key_filepath != NULL) {
2604                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
2605                         return NULL;
2606                 }
2607                 fprintf(stderr, " Compiled without SSL support, "
2608                                                        "serving unencrypted\n");
2609 #endif
2610         }
2611
2612         /* ignore SIGPIPE */
2613 #ifdef WIN32
2614 #else
2615         signal(SIGPIPE, sigpipe_handler);
2616 #endif
2617
2618
2619 #ifdef LWS_OPENSSL_SUPPORT
2620
2621         /* basic openssl init */
2622
2623         SSL_library_init();
2624
2625         OpenSSL_add_all_algorithms();
2626         SSL_load_error_strings();
2627
2628         openssl_websocket_private_data_index =
2629                 SSL_get_ex_new_index(0, "libwebsockets", NULL, NULL, NULL);
2630
2631         /*
2632          * Firefox insists on SSLv23 not SSLv3
2633          * Konq disables SSLv2 by default now, SSLv23 works
2634          */
2635
2636         method = (SSL_METHOD *)SSLv23_server_method();
2637         if (!method) {
2638                 fprintf(stderr, "problem creating ssl method: %s\n",
2639                         ERR_error_string(ERR_get_error(), ssl_err_buf));
2640                 return NULL;
2641         }
2642         context->ssl_ctx = SSL_CTX_new(method); /* create context */
2643         if (!context->ssl_ctx) {
2644                 fprintf(stderr, "problem creating ssl context: %s\n",
2645                         ERR_error_string(ERR_get_error(), ssl_err_buf));
2646                 return NULL;
2647         }
2648
2649         /* client context */
2650         if (port == CONTEXT_PORT_NO_LISTEN)
2651         {
2652                 method = (SSL_METHOD *)SSLv23_client_method();
2653                 if (!method) {
2654                         fprintf(stderr, "problem creating ssl method: %s\n",
2655                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2656                         return NULL;
2657                 }
2658                 /* create context */
2659                 context->ssl_client_ctx = SSL_CTX_new(method);
2660                 if (!context->ssl_client_ctx) {
2661                         fprintf(stderr, "problem creating ssl context: %s\n",
2662                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2663                         return NULL;
2664                 }
2665
2666                 /* openssl init for cert verification (for client sockets) */
2667
2668                 if (!SSL_CTX_load_verify_locations(
2669                                         context->ssl_client_ctx, NULL,
2670                                                       LWS_OPENSSL_CLIENT_CERTS))
2671                         fprintf(stderr,
2672                             "Unable to load SSL Client certs from %s "
2673                             "(set by --with-client-cert-dir= in configure) -- "
2674                                 " client ssl isn't going to work",
2675                                                       LWS_OPENSSL_CLIENT_CERTS);
2676
2677                 /*
2678                  * callback allowing user code to load extra verification certs
2679                  * helping the client to verify server identity
2680                  */
2681
2682                 context->protocols[0].callback(context, NULL,
2683                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
2684                         context->ssl_client_ctx, NULL, 0);
2685         }
2686         /* as a server, are we requiring clients to identify themselves? */
2687
2688         if (options & LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT) {
2689
2690                 /* absolutely require the client cert */
2691                 
2692                 SSL_CTX_set_verify(context->ssl_ctx,
2693                        SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
2694                                                        OpenSSL_verify_callback);
2695
2696                 /*
2697                  * give user code a chance to load certs into the server
2698                  * allowing it to verify incoming client certs
2699                  */
2700
2701                 context->protocols[0].callback(context, NULL,
2702                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
2703                                                      context->ssl_ctx, NULL, 0);
2704         }
2705
2706         if (context->use_ssl) {
2707
2708                 /* openssl init for server sockets */
2709
2710                 /* set the local certificate from CertFile */
2711                 n = SSL_CTX_use_certificate_file(context->ssl_ctx,
2712                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
2713                 if (n != 1) {
2714                         fprintf(stderr, "problem getting cert '%s': %s\n",
2715                                 ssl_cert_filepath,
2716                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2717                         return NULL;
2718                 }
2719                 /* set the private key from KeyFile */
2720                 if (SSL_CTX_use_PrivateKey_file(context->ssl_ctx,
2721                              ssl_private_key_filepath, SSL_FILETYPE_PEM) != 1) {
2722                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
2723                                                 ssl_private_key_filepath,
2724                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2725                         return NULL;
2726                 }
2727                 /* verify private key */
2728                 if (!SSL_CTX_check_private_key(context->ssl_ctx)) {
2729                         fprintf(stderr, "Private SSL key doesn't match cert\n");
2730                         return NULL;
2731                 }
2732
2733                 /* SSL is happy and has a cert it's content with */
2734         }
2735 #endif
2736
2737         /* selftest */
2738
2739         if (lws_b64_selftest())
2740                 return NULL;
2741
2742         /* fd hashtable init */
2743
2744         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
2745                 context->fd_hashtable[n].length = 0;
2746
2747         /* set up our external listening socket we serve on */
2748
2749         if (port) {
2750
2751                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
2752                 if (sockfd < 0) {
2753                         fprintf(stderr, "ERROR opening socket");
2754                         return NULL;
2755                 }
2756
2757                 /* allow us to restart even if old sockets in TIME_WAIT */
2758                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (const void *)&opt, sizeof(opt));
2759
2760
2761                 /* Disable Nagle */
2762                 opt = 1;
2763                 setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, (const void *)&opt, sizeof(opt));
2764
2765                 bzero((char *) &serv_addr, sizeof(serv_addr));
2766                 serv_addr.sin_family = AF_INET;
2767                 if (interf == NULL)
2768                         serv_addr.sin_addr.s_addr = INADDR_ANY;
2769                 else
2770                         interface_to_sa(interf, &serv_addr,
2771                                                 sizeof(serv_addr));
2772                 serv_addr.sin_port = htons(port);
2773
2774                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
2775                                                              sizeof(serv_addr));
2776                 if (n < 0) {
2777                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
2778                                                                 port, n, errno);
2779                         return NULL;
2780                 }
2781
2782                 wsi = malloc(sizeof(struct libwebsocket));
2783                 memset(wsi, 0, sizeof (struct libwebsocket));
2784                 wsi->sock = sockfd;
2785                 wsi->count_active_extensions = 0;
2786                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
2787                 insert_wsi(context, wsi);
2788
2789                 listen(sockfd, 5);
2790                 fprintf(stderr, " Listening on port %d\n", port);
2791
2792                 /* list in the internal poll array */
2793                 
2794                 context->fds[context->fds_count].fd = sockfd;
2795                 context->fds[context->fds_count++].events = POLLIN;
2796
2797                 /* external POLL support via protocol 0 */
2798                 context->protocols[0].callback(context, wsi,
2799                         LWS_CALLBACK_ADD_POLL_FD,
2800                         (void *)(long)sockfd, NULL, POLLIN);
2801
2802         }
2803
2804         /* drop any root privs for this process */
2805 #ifdef WIN32
2806 #else
2807         if (gid != -1)
2808                 if (setgid(gid))
2809                         fprintf(stderr, "setgid: %s\n", strerror(errno));
2810         if (uid != -1)
2811                 if (setuid(uid))
2812                         fprintf(stderr, "setuid: %s\n", strerror(errno));
2813 #endif
2814
2815         /* set up our internal broadcast trigger sockets per-protocol */
2816
2817         for (context->count_protocols = 0;
2818                         protocols[context->count_protocols].callback;
2819                                                    context->count_protocols++) {
2820
2821                 fprintf(stderr, "  Protocol: %s\n", protocols[context->count_protocols].name);
2822
2823                 protocols[context->count_protocols].owning_server = context;
2824                 protocols[context->count_protocols].protocol_index =
2825                                                        context->count_protocols;
2826
2827                 fd = socket(AF_INET, SOCK_STREAM, 0);
2828                 if (fd < 0) {
2829                         fprintf(stderr, "ERROR opening socket");
2830                         return NULL;
2831                 }
2832
2833                 /* allow us to restart even if old sockets in TIME_WAIT */
2834                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (const void *)&opt, sizeof(opt));
2835
2836                 bzero((char *) &serv_addr, sizeof(serv_addr));
2837                 serv_addr.sin_family = AF_INET;
2838                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
2839                 serv_addr.sin_port = 0; /* pick the port for us */
2840
2841                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
2842                 if (n < 0) {
2843                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
2844                                                                 port, n, errno);
2845                         return NULL;
2846                 }
2847
2848                 slen = sizeof cli_addr;
2849                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
2850                 if (n < 0) {
2851                         fprintf(stderr, "getsockname failed\n");
2852                         return NULL;
2853                 }
2854                 protocols[context->count_protocols].broadcast_socket_port =
2855                                                        ntohs(cli_addr.sin_port);
2856                 listen(fd, 5);
2857
2858                 debug("  Protocol %s broadcast socket %d\n",
2859                                 protocols[context->count_protocols].name,
2860                                                       ntohs(cli_addr.sin_port));
2861
2862                 /* dummy wsi per broadcast proxy socket */
2863
2864                 wsi = malloc(sizeof(struct libwebsocket));
2865                 memset(wsi, 0, sizeof (struct libwebsocket));
2866                 wsi->sock = fd;
2867                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
2868                 wsi->count_active_extensions = 0;
2869                 /* note which protocol we are proxying */
2870                 wsi->protocol_index_for_broadcast_proxy =
2871                                                        context->count_protocols;
2872                 insert_wsi(context, wsi);
2873
2874                 /* list in internal poll array */
2875
2876                 context->fds[context->fds_count].fd = fd;
2877                 context->fds[context->fds_count].events = POLLIN;
2878                 context->fds[context->fds_count].revents = 0;
2879                 context->fds_count++;
2880
2881                 /* external POLL support via protocol 0 */
2882                 context->protocols[0].callback(context, wsi,
2883                         LWS_CALLBACK_ADD_POLL_FD,
2884                         (void *)(long)fd, NULL, POLLIN);
2885         }
2886
2887         /*
2888          * give all extensions a chance to create any per-context
2889          * allocations they need
2890          */
2891
2892         m = LWS_EXT_CALLBACK_CLIENT_CONTEXT_CONSTRUCT;
2893         if (port)
2894                 m = LWS_EXT_CALLBACK_SERVER_CONTEXT_CONSTRUCT;
2895         while (extensions->callback) {
2896                 fprintf(stderr, "  Extension: %s\n", extensions->name);
2897                 extensions->callback(context, extensions,
2898                                                         NULL, m, NULL, NULL, 0);
2899                 extensions++;
2900         }
2901
2902         return context;
2903 }
2904
2905
2906 #ifndef LWS_NO_FORK
2907
2908 /**
2909  * libwebsockets_fork_service_loop() - Optional helper function forks off
2910  *                                a process for the websocket server loop.
2911  *                              You don't have to use this but if not, you
2912  *                              have to make sure you are calling
2913  *                              libwebsocket_service periodically to service
2914  *                              the websocket traffic
2915  * @context:    server context returned by creation function
2916  */
2917
2918 int
2919 libwebsockets_fork_service_loop(struct libwebsocket_context *context)
2920 {
2921         int fd;
2922         struct sockaddr_in cli_addr;
2923         int n;
2924         int p;
2925
2926         n = fork();
2927         if (n < 0)
2928                 return n;
2929
2930         if (!n) {
2931
2932                 /* main process context */
2933
2934                 /*
2935                  * set up the proxy sockets to allow broadcast from
2936                  * service process context
2937                  */
2938
2939                 for (p = 0; p < context->count_protocols; p++) {
2940                         fd = socket(AF_INET, SOCK_STREAM, 0);
2941                         if (fd < 0) {
2942                                 fprintf(stderr, "Unable to create socket\n");
2943                                 return -1;
2944                         }
2945                         cli_addr.sin_family = AF_INET;
2946                         cli_addr.sin_port = htons(
2947                              context->protocols[p].broadcast_socket_port);
2948                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
2949                         n = connect(fd, (struct sockaddr *)&cli_addr,
2950                                                                sizeof cli_addr);
2951                         if (n < 0) {
2952                                 fprintf(stderr, "Unable to connect to "
2953                                                 "broadcast socket %d, %s\n",
2954                                                 n, strerror(errno));
2955                                 return -1;
2956                         }
2957
2958                         context->protocols[p].broadcast_socket_user_fd = fd;
2959                 }
2960
2961                 return 0;
2962         }
2963
2964         /* we want a SIGHUP when our parent goes down */
2965         prctl(PR_SET_PDEATHSIG, SIGHUP);
2966
2967         /* in this forked process, sit and service websocket connections */
2968
2969         while (1)
2970                 if (libwebsocket_service(context, 1000))
2971                         return -1;
2972
2973         return 0;
2974 }
2975
2976 #endif
2977
2978 /**
2979  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
2980  *                                connection.
2981  * @wsi:        pointer to struct websocket you want to know the protocol of
2982  *
2983  *
2984  *      This is useful to get the protocol to broadcast back to from inside
2985  * the callback.
2986  */
2987
2988 const struct libwebsocket_protocols *
2989 libwebsockets_get_protocol(struct libwebsocket *wsi)
2990 {
2991         return wsi->protocol;
2992 }
2993
2994 /**
2995  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
2996  *                                connections of the given protocol.
2997  * @protocol:   pointer to the protocol you will broadcast to all members of
2998  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
2999  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
3000  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
3001  *              case you are calling this function from callback context.
3002  * @len:        length of payload data in buf, starting from buf.
3003  *
3004  *      This function allows bulk sending of a packet to every connection using
3005  * the given protocol.  It does not send the data directly; instead it calls
3006  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
3007  * wants to actually send the data for that connection, the callback itself
3008  * should call libwebsocket_write().
3009  *
3010  * libwebsockets_broadcast() can be called from another fork context without
3011  * having to take any care about data visibility between the processes, it'll
3012  * "just work".
3013  */
3014
3015
3016 int
3017 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
3018                                                  unsigned char *buf, size_t len)
3019 {
3020         struct libwebsocket_context *context = protocol->owning_server;
3021         int n;
3022         int m;
3023         struct libwebsocket * wsi;
3024
3025         if (!protocol->broadcast_socket_user_fd) {
3026                 /*
3027                  * We are either running unforked / flat, or we are being
3028                  * called from poll thread context
3029                  * eg, from a callback.  In that case don't use sockets for
3030                  * broadcast IPC (since we can't open a socket connection to
3031                  * a socket listening on our own thread) but directly do the
3032                  * send action.
3033                  *
3034                  * Locking is not needed because we are by definition being
3035                  * called in the poll thread context and are serialized.
3036                  */
3037
3038                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
3039
3040                         for (m = 0; m < context->fd_hashtable[n].length; m++) {
3041
3042                                 wsi = context->fd_hashtable[n].wsi[m];
3043
3044                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
3045                                         continue;
3046
3047                                 /*
3048                                  * never broadcast to
3049                                  * non-established connections
3050                                  */
3051                                 if (wsi->state != WSI_STATE_ESTABLISHED)
3052                                         continue;
3053
3054                                 /* only broadcast to guys using
3055                                  * requested protocol
3056                                  */
3057                                 if (wsi->protocol != protocol)
3058                                         continue;
3059
3060                                 wsi->protocol->callback(context, wsi,
3061                                          LWS_CALLBACK_BROADCAST,
3062                                          wsi->user_space,
3063                                          buf, len);
3064                         }
3065                 }
3066
3067                 return 0;
3068         }
3069
3070         /*
3071          * We're being called from a different process context than the server
3072          * loop.  Instead of broadcasting directly, we send our
3073          * payload on a socket to do the IPC; the server process will serialize
3074          * the broadcast action in its main poll() loop.
3075          *
3076          * There's one broadcast socket listening for each protocol supported
3077          * set up when the websocket server initializes
3078          */
3079
3080         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
3081
3082         return n;
3083 }
3084
3085 int
3086 libwebsocket_is_final_fragment(struct libwebsocket *wsi)
3087 {
3088         return wsi->final;
3089 }
3090
3091 void *
3092 libwebsocket_ensure_user_space(struct libwebsocket *wsi)
3093 {
3094         /* allocate the per-connection user memory (if any) */
3095
3096         if (wsi->protocol->per_session_data_size && !wsi->user_space) {
3097                 wsi->user_space = malloc(
3098                                   wsi->protocol->per_session_data_size);
3099                 if (wsi->user_space  == NULL) {
3100                         fprintf(stderr, "Out of memory for "
3101                                                    "conn user space\n");
3102                         return NULL;
3103                 }
3104                 memset(wsi->user_space, 0, wsi->protocol->per_session_data_size);
3105         }
3106         return wsi->user_space;
3107 }