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