lib/libwebsockets.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23
  24 #ifdef WIN32
  25
  26 #else
  27 #include <ifaddrs.h>
  28 #include <sys/un.h>
  29 #endif
  30
  31 #ifdef LWS_OPENSSL_SUPPORT
  32 int openssl_websocket_private_data_index;
  33 #endif
  34
  35 /*
  36  * In-place str to lower case
  37  */
  38
  39 static void
  40 strtolower(char *s)
  41 {
  42         while (*s) {
  43                 *s = tolower(*s);
  44                 s++;
  45         }
  46 }
  47
  48 /* file descriptor hash management */
  49
  50 struct libwebsocket *
  51 wsi_from_fd(struct libwebsocket_context *context, int fd)
  52 {
  53         int h = LWS_FD_HASH(fd);
  54         int n = 0;
  55
  56         for (n = 0; n < context->fd_hashtable[h].length; n++)
  57                 if (context->fd_hashtable[h].wsi[n]->sock == fd)
  58                         return context->fd_hashtable[h].wsi[n];
  59
  60         return NULL;
  61 }
  62
  63 int
  64 insert_wsi(struct libwebsocket_context *context, struct libwebsocket *wsi)
  65 {
  66         int h = LWS_FD_HASH(wsi->sock);
  67
  68         if (context->fd_hashtable[h].length == MAX_CLIENTS - 1) {
  69                 fprintf(stderr, "hash table overflow\n");
  70                 return 1;
  71         }
  72
  73         context->fd_hashtable[h].wsi[context->fd_hashtable[h].length++] = wsi;
  74
  75         return 0;
  76 }
  77
  78 int
  79 delete_from_fd(struct libwebsocket_context *context, int fd)
  80 {
  81         int h = LWS_FD_HASH(fd);
  82         int n = 0;
  83
  84         for (n = 0; n < context->fd_hashtable[h].length; n++)
  85                 if (context->fd_hashtable[h].wsi[n]->sock == fd) {
  86                         while (n < context->fd_hashtable[h].length) {
  87                                 context->fd_hashtable[h].wsi[n] =
  88                                             context->fd_hashtable[h].wsi[n + 1];
  89                                 n++;
  90                         }
  91                         context->fd_hashtable[h].length--;
  92
  93                         return 0;
  94                 }
  95
  96         fprintf(stderr, "Failed to find fd %d requested for "
  97                                                    "delete in hashtable\n", fd);
  98         return 1;
  99 }
 100
 101 #ifdef LWS_OPENSSL_SUPPORT
 102 static void
 103 libwebsockets_decode_ssl_error(void)
 104 {
 105         char buf[256];
 106         u_long err;
 107
 108         while ((err = ERR_get_error()) != 0) {
 109                 ERR_error_string_n(err, buf, sizeof(buf));
 110                 fprintf(stderr, "*** %s\n", buf);
 111         }
 112 }
 113 #endif
 114
 115
 116 static int
 117 interface_to_sa(const char* ifname, struct sockaddr_in *addr, size_t addrlen)
 118 {
 119         int rc = -1;
 120 #ifdef WIN32
 121         // TODO
 122 #else
 123         struct ifaddrs *ifr;
 124         struct ifaddrs *ifc;
 125         struct sockaddr_in *sin;
 126
 127         getifaddrs(&ifr);
 128         for (ifc = ifr; ifc != NULL; ifc = ifc->ifa_next) {
 129                 if (strcmp(ifc->ifa_name, ifname))
 130                         continue;
 131                 if (ifc->ifa_addr == NULL)
 132                         continue;
 133                 sin = (struct sockaddr_in *)ifc->ifa_addr;
 134                 if (sin->sin_family != AF_INET)
 135                         continue;
 136                 memcpy(addr, sin, addrlen);
 137                 rc = 0;
 138         }
 139
 140         freeifaddrs(ifr);
 141 #endif
 142         return rc;
 143 }
 144
 145 void
 146 libwebsocket_close_and_free_session(struct libwebsocket_context *context,
 147                          struct libwebsocket *wsi, enum lws_close_status reason)
 148 {
 149         int n;
 150         int old_state;
 151         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
 152                                                   LWS_SEND_BUFFER_POST_PADDING];
 153         int ret;
 154         int m;
 155         struct lws_tokens eff_buf;
 156
 157         if (!wsi)
 158                 return;
 159
 160         old_state = wsi->state;
 161
 162         if (old_state == WSI_STATE_DEAD_SOCKET)
 163                 return;
 164
 165         wsi->close_reason = reason;
 166
 167         /*
 168          * flush any tx pending from extensions, since we may send close packet
 169          * if there are problems with send, just nuke the connection
 170          */
 171
 172         ret = 1;
 173         while (ret == 1) {
 174
 175                 /* default to nobody has more to spill */
 176
 177                 ret = 0;
 178                 eff_buf.token = NULL;
 179                 eff_buf.token_len = 0;
 180
 181                 /* show every extension the new incoming data */
 182
 183                 for (n = 0; n < wsi->count_active_extensions; n++) {
 184                         m = wsi->active_extensions[n]->callback(
 185                                         wsi->protocol->owning_server,
 186                                         wsi->active_extensions[n], wsi,
 187                                         LWS_EXT_CALLBACK_FLUSH_PENDING_TX,
 188                                    wsi->active_extensions_user[n], &eff_buf, 0);
 189                         if (m < 0) {
 190                                 fprintf(stderr, "Extension reports "
 191                                                                "fatal error\n");
 192                                 goto just_kill_connection;
 193                         }
 194                         if (m)
 195                                 /*
 196                                  * at least one extension told us he has more
 197                                  * to spill, so we will go around again after
 198                                  */
 199                                 ret = 1;
 200                 }
 201
 202                 /* assuming they left us something to send, send it */
 203
 204                 if (eff_buf.token_len)
 205                         if (lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
 206                                                              eff_buf.token_len))
 207                                 goto just_kill_connection;
 208         }
 209
 210         /*
 211          * signal we are closing, libsocket_write will
 212          * add any necessary version-specific stuff.  If the write fails,
 213          * no worries we are closing anyway.  If we didn't initiate this
 214          * close, then our state has been changed to
 215          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this.
 216          *
 217          * Likewise if it's a second call to close this connection after we
 218          * sent the close indication to the peer already, we are in state
 219          * WSI_STATE_AWAITING_CLOSE_ACK and will skip doing this a second time.
 220          */
 221
 222         if (old_state == WSI_STATE_ESTABLISHED &&
 223                                           reason != LWS_CLOSE_STATUS_NOSTATUS) {
 224                 n = libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING],
 225                                                             0, LWS_WRITE_CLOSE);
 226                 if (!n) {
 227                         /*
 228                          * we have sent a nice protocol level indication we
 229                          * now wish to close, we should not send anything more
 230                          */
 231
 232                         wsi->state = WSI_STATE_AWAITING_CLOSE_ACK;
 233
 234                         /* and we should wait for a reply for a bit */
 235
 236                         libwebsocket_set_timeout(wsi,
 237                                                   PENDING_TIMEOUT_CLOSE_ACK, 5);
 238
 239                         fprintf(stderr, "sent close indication, awaiting ack\n");
 240
 241                         return;
 242                 }
 243
 244                 /* else, the send failed and we should just hang up */
 245         }
 246
 247 just_kill_connection:
 248         /*
 249          * we won't be servicing or receiving anything further from this guy
 250          * remove this fd from wsi mapping hashtable
 251          */
 252
 253         delete_from_fd(context, wsi->sock);
 254
 255         /* delete it from the internal poll list if still present */
 256
 257         for (n = 0; n < context->fds_count; n++) {
 258                 if (context->fds[n].fd != wsi->sock)
 259                         continue;
 260                 while (n < context->fds_count - 1) {
 261                         context->fds[n] = context->fds[n + 1];
 262                         n++;
 263                 }
 264                 context->fds_count--;
 265                 /* we only have to deal with one */
 266                 n = context->fds_count;
 267         }
 268
 269         /* remove also from external POLL support via protocol 0 */
 270
 271         context->protocols[0].callback(context, wsi,
 272                     LWS_CALLBACK_DEL_POLL_FD, (void *)(long)wsi->sock, NULL, 0);
 273
 274         wsi->state = WSI_STATE_DEAD_SOCKET;
 275
 276         /* tell the user it's all over for this guy */
 277
 278         if (wsi->protocol && wsi->protocol->callback &&
 279                                              old_state == WSI_STATE_ESTABLISHED)
 280                 wsi->protocol->callback(context, wsi, LWS_CALLBACK_CLOSED,
 281                                                       wsi->user_space, NULL, 0);
 282
 283         /* deallocate any active extension contexts */
 284
 285         for (n = 0; n < wsi->count_active_extensions; n++) {
 286                 if (!wsi->active_extensions[n]->callback)
 287                         continue;
 288
 289                 wsi->active_extensions[n]->callback(context,
 290                         wsi->active_extensions[n], wsi,
 291                                 LWS_EXT_CALLBACK_DESTROY,
 292                                        wsi->active_extensions_user[n], NULL, 0);
 293
 294                 free(wsi->active_extensions_user[n]);
 295         }
 296
 297         /* free up his parsing allocations */
 298
 299         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 300                 if (wsi->utf8_token[n].token)
 301                         free(wsi->utf8_token[n].token);
 302
 303 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 304
 305 #ifdef LWS_OPENSSL_SUPPORT
 306         if (wsi->ssl) {
 307                 n = SSL_get_fd(wsi->ssl);
 308                 SSL_shutdown(wsi->ssl);
 309 #ifdef WIN32
 310                 closesocket(n);
 311 #else
 312                 close(n);
 313 #endif
 314                 SSL_free(wsi->ssl);
 315         } else {
 316 #endif
 317                 shutdown(wsi->sock, SHUT_RDWR);
 318 #ifdef WIN32
 319                 closesocket(wsi->sock);
 320 #else
 321                 close(wsi->sock);
 322 #endif
 323 #ifdef LWS_OPENSSL_SUPPORT
 324         }
 325 #endif
 326         if (wsi->user_space)
 327                 free(wsi->user_space);
 328
 329         free(wsi);
 330 }
 331
 332 /**
 333  * libwebsockets_hangup_on_client() - Server calls to terminate client
 334  *                                      connection
 335  * @context:    libwebsockets context
 336  * @fd:         Connection socket descriptor
 337  */
 338
 339 void
 340 libwebsockets_hangup_on_client(struct libwebsocket_context *context, int fd)
 341 {
 342         struct libwebsocket *wsi = wsi_from_fd(context, fd);
 343
 344         if (wsi == NULL)
 345                 return;
 346
 347         libwebsocket_close_and_free_session(context, wsi,
 348                                                      LWS_CLOSE_STATUS_NOSTATUS);
 349 }
 350
 351
 352 /**
 353  * libwebsockets_get_peer_addresses() - Get client address information
 354  * @fd:         Connection socket descriptor
 355  * @name:       Buffer to take client address name
 356  * @name_len:   Length of client address name buffer
 357  * @rip:        Buffer to take client address IP qotted quad
 358  * @rip_len:    Length of client address IP buffer
 359  *
 360  *      This function fills in @name and @rip with the name and IP of
 361  *      the client connected with socket descriptor @fd.  Names may be
 362  *      truncated if there is not enough room.  If either cannot be
 363  *      determined, they will be returned as valid zero-length strings.
 364  */
 365
 366 void
 367 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 368                                         char *rip, int rip_len)
 369 {
 370         unsigned int len;
 371         struct sockaddr_in sin;
 372         struct hostent *host;
 373         struct hostent *host1;
 374         char ip[128];
 375         unsigned char *p;
 376         int n;
 377         struct sockaddr_un *un;
 378
 379         rip[0] = '\0';
 380         name[0] = '\0';
 381
 382         len = sizeof sin;
 383         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 384                 perror("getpeername");
 385                 return;
 386         }
 387
 388         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 389                                                                        AF_INET);
 390         if (host == NULL) {
 391                 perror("gethostbyaddr");
 392                 return;
 393         }
 394
 395         strncpy(name, host->h_name, name_len);
 396         name[name_len - 1] = '\0';
 397
 398         host1 = gethostbyname(host->h_name);
 399         if (host1 == NULL)
 400                 return;
 401         p = (unsigned char *)host1;
 402         n = 0;
 403         while (p != NULL) {
 404                 p = (unsigned char *)host1->h_addr_list[n++];
 405                 if (p == NULL)
 406                         continue;
 407                 if ((host1->h_addrtype != AF_INET)
 408 #ifdef AF_LOCAL
 409                         && (host1->h_addrtype != AF_LOCAL)
 410 #endif
 411                         )
 412                         continue;
 413
 414                 if (host1->h_addrtype == AF_INET)
 415                         sprintf(ip, "%u.%u.%u.%u", p[0], p[1], p[2], p[3]);
 416 #ifdef AF_LOCAL
 417                 else {
 418                         un = (struct sockaddr_un *)p;
 419                         strncpy(ip, un->sun_path, sizeof(ip) -1);
 420                         ip[sizeof(ip) - 1] = '\0';
 421                 }
 422 #endif
 423                 p = NULL;
 424                 strncpy(rip, ip, rip_len);
 425                 rip[rip_len - 1] = '\0';
 426         }
 427 }
 428
 429 int libwebsockets_get_random(struct libwebsocket_context *context,
 430                                                              void *buf, int len)
 431 {
 432         int n;
 433         char *p = buf;
 434
 435 #ifdef WIN32
 436         for (n = 0; n < len; n++)
 437                 p[n] = (unsigned char)rand();
 438 #else
 439         n = read(context->fd_random, p, len);
 440 #endif
 441
 442         return n;
 443 }
 444
 445 unsigned char *
 446 libwebsockets_SHA1(const unsigned char *d, size_t n, unsigned char *md)
 447 {
 448         return SHA1(d, n, md);
 449 }
 450
 451 void libwebsockets_00_spaceout(char *key, int spaces, int seed)
 452 {
 453         char *p;
 454
 455         key++;
 456         while (spaces--) {
 457                 if (*key && (seed & 1))
 458                         key++;
 459                 seed >>= 1;
 460
 461                 p = key + strlen(key);
 462                 while (p >= key) {
 463                         p[1] = p[0];
 464                         p--;
 465                 }
 466                 *key++ = ' ';
 467         }
 468 }
 469
 470 void libwebsockets_00_spam(char *key, int count, int seed)
 471 {
 472         char *p;
 473
 474         key++;
 475         while (count--) {
 476
 477                 if (*key && (seed & 1))
 478                         key++;
 479                 seed >>= 1;
 480
 481                 p = key + strlen(key);
 482                 while (p >= key) {
 483                         p[1] = p[0];
 484                         p--;
 485                 }
 486                 *key++ = 0x21 + ((seed & 0xffff) % 15);
 487                 /* 4 would use it up too fast.. not like it matters */
 488                 seed >>= 1;
 489         }
 490 }
 491
 492 int lws_send_pipe_choked(struct libwebsocket *wsi)
 493 {
 494         struct pollfd fds;
 495
 496         fds.fd = wsi->sock;
 497         fds.events = POLLOUT;
 498         fds.revents = 0;
 499
 500         if (poll(&fds, 1, 0) != 1)
 501                 return 1;
 502
 503         if ((fds.revents & POLLOUT) == 0)
 504                 return 1;
 505
 506         /* okay to send another packet without blocking */
 507
 508         return 0;
 509 }
 510
 511 static int
 512 lws_handle_POLLOUT_event(struct libwebsocket_context *context,
 513                                 struct libwebsocket *wsi, struct pollfd *pollfd)
 514 {
 515         struct lws_tokens eff_buf;
 516         int n;
 517         int ret;
 518         int m;
 519
 520         if (!wsi->extension_data_pending)
 521                 goto user_service;
 522
 523         /*
 524          * check in on the active extensions, see if they
 525          * had pending stuff to spill... they need to get the
 526          * first look-in otherwise sequence will be disordered
 527          *
 528          * NULL, zero-length eff_buf means just spill pending
 529          */
 530
 531         ret = 1;
 532         while (ret == 1) {
 533
 534                 /* default to nobody has more to spill */
 535
 536                 ret = 0;
 537                 eff_buf.token = NULL;
 538                 eff_buf.token_len = 0;
 539
 540                 /* give every extension a chance to spill */
 541
 542                 for (n = 0; n < wsi->count_active_extensions; n++) {
 543                         m = wsi->active_extensions[n]->callback(
 544                                 wsi->protocol->owning_server,
 545                                 wsi->active_extensions[n], wsi,
 546                                         LWS_EXT_CALLBACK_PACKET_TX_PRESEND,
 547                                    wsi->active_extensions_user[n], &eff_buf, 0);
 548                         if (m < 0) {
 549                                 fprintf(stderr, "extension reports fatal error\n");
 550                                 return -1;
 551                         }
 552                         if (m)
 553                                 /*
 554                                  * at least one extension told us he has more
 555                                  * to spill, so we will go around again after
 556                                  */
 557                                 ret = 1;
 558                 }
 559
 560                 /* assuming they gave us something to send, send it */
 561
 562                 if (eff_buf.token_len) {
 563                         if (lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
 564                                                              eff_buf.token_len))
 565                                 return -1;
 566                 } else
 567                         continue;
 568
 569                 /* no extension has more to spill */
 570
 571                 if (!ret)
 572                         continue;
 573
 574                 /*
 575                  * There's more to spill from an extension, but we just sent
 576                  * something... did that leave the pipe choked?
 577                  */
 578
 579                 if (!lws_send_pipe_choked(wsi))
 580                         /* no we could add more */
 581                         continue;
 582
 583                 fprintf(stderr, "choked in POLLOUT service\n");
 584
 585                 /*
 586                  * Yes, he's choked.  Leave the POLLOUT masked on so we will
 587                  * come back here when he is unchoked.  Don't call the user
 588                  * callback to enforce ordering of spilling, he'll get called
 589                  * when we come back here and there's nothing more to spill.
 590                  */
 591
 592                 return 0;
 593         }
 594
 595         wsi->extension_data_pending = 0;
 596
 597 user_service:
 598         /* one shot */
 599
 600         pollfd->events &= ~POLLOUT;
 601
 602         /* external POLL support via protocol 0 */
 603         context->protocols[0].callback(context, wsi,
 604                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 605                 (void *)(long)wsi->sock, NULL, POLLOUT);
 606
 607         if (wsi->mode == LWS_CONNMODE_WS_CLIENT)
 608                 n = LWS_CALLBACK_CLIENT_WRITEABLE;
 609         else
 610                 n = LWS_CALLBACK_SERVER_WRITEABLE;
 611
 612         wsi->protocol->callback(context, wsi, n, wsi->user_space, NULL, 0);
 613
 614         return 0;
 615 }
 616
 617
 618
 619 /**
 620  * libwebsocket_service_fd() - Service polled socket with something waiting
 621  * @context:    Websocket context
 622  * @pollfd:     The pollfd entry describing the socket fd and which events
 623  *              happened.
 624  *
 625  *      This function closes any active connections and then frees the
 626  *      context.  After calling this, any further use of the context is
 627  *      undefined.
 628  */
 629
 630 int
 631 libwebsocket_service_fd(struct libwebsocket_context *context,
 632                                                           struct pollfd *pollfd)
 633 {
 634         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 1 + MAX_BROADCAST_PAYLOAD +
 635                                                   LWS_SEND_BUFFER_POST_PADDING];
 636         struct libwebsocket *wsi;
 637         struct libwebsocket *new_wsi;
 638         int n;
 639         int m;
 640         size_t len;
 641         int accept_fd;
 642         unsigned int clilen;
 643         struct sockaddr_in cli_addr;
 644         struct timeval tv;
 645         static const char magic_websocket_guid[] =
 646                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 647         static const char magic_websocket_04_masking_guid[] =
 648                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 649         char hash[20];
 650         char pkt[1024];
 651         char *p = &pkt[0];
 652         const char *pc;
 653         const char *c;
 654         int more = 1;
 655         int okay = 0;
 656         char ext_name[128];
 657         struct lws_tokens eff_buf;
 658         int ext_count = 0;
 659         struct libwebsocket_extension *ext;
 660         int opt = 1;
 661
 662 #ifdef LWS_OPENSSL_SUPPORT
 663         char ssl_err_buf[512];
 664 #endif
 665         /*
 666          * you can call us with pollfd = NULL to just allow the once-per-second
 667          * global timeout checks; if less than a second since the last check
 668          * it returns immediately then.
 669          */
 670
 671         gettimeofday(&tv, NULL);
 672
 673         if (context->last_timeout_check_s != tv.tv_sec) {
 674                 context->last_timeout_check_s = tv.tv_sec;
 675
 676                 /* global timeout check once per second */
 677
 678                 for (n = 0; n < context->fds_count; n++) {
 679                         wsi = wsi_from_fd(context, context->fds[n].fd);
 680                         if (!wsi->pending_timeout)
 681                                 continue;
 682
 683                         /*
 684                          * if we went beyond the allowed time, kill the
 685                          * connection
 686                          */
 687
 688                         if (tv.tv_sec > wsi->pending_timeout_limit) {
 689                                 fprintf(stderr, "TIMEDOUT WAITING\n");
 690                                 libwebsocket_close_and_free_session(context,
 691                                                 wsi, LWS_CLOSE_STATUS_NOSTATUS);
 692                         }
 693                 }
 694         }
 695
 696         /* just here for timeout management? */
 697
 698         if (pollfd == NULL)
 699                 return 0;
 700
 701         /* no, here to service a socket descriptor */
 702
 703         wsi = wsi_from_fd(context, pollfd->fd);
 704
 705         if (wsi == NULL)
 706                 return 1;
 707
 708         switch (wsi->mode) {
 709         case LWS_CONNMODE_SERVER_LISTENER:
 710
 711                 /* pollin means a client has connected to us then */
 712
 713                 if (!pollfd->revents & POLLIN)
 714                         break;
 715
 716                 /* listen socket got an unencrypted connection... */
 717
 718                 clilen = sizeof(cli_addr);
 719                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 720                                                                        &clilen);
 721                 if (accept_fd < 0) {
 722                         fprintf(stderr, "ERROR on accept");
 723                         break;
 724                 }
 725
 726                 /* Disable Nagle */
 727                 opt = 1;
 728                 setsockopt(accept_fd, IPPROTO_TCP, TCP_NODELAY, &opt,
 729                                 sizeof(opt));
 730
 731                 if (context->fds_count >= MAX_CLIENTS) {
 732                         fprintf(stderr, "too busy to accept new client\n");
 733 #ifdef WIN32
 734                         closesocket(accept_fd);
 735 #else
 736                         close(accept_fd);
 737 #endif
 738                         break;
 739                 }
 740
 741                 /*
 742                  * look at who we connected to and give user code a chance
 743                  * to reject based on client IP.  There's no protocol selected
 744                  * yet so we issue this to protocols[0]
 745                  */
 746
 747                 if ((context->protocols[0].callback)(context, wsi,
 748                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 749                                              (void*)(long)accept_fd, NULL, 0)) {
 750                         fprintf(stderr, "Callback denied network connection\n");
 751 #ifdef WIN32
 752                         closesocket(accept_fd);
 753 #else
 754                         close(accept_fd);
 755 #endif
 756                         break;
 757                 }
 758
 759                 /* accepting connection to main listener */
 760
 761                 new_wsi = malloc(sizeof(struct libwebsocket));
 762                 if (new_wsi == NULL) {
 763                         fprintf(stderr, "Out of memory for new connection\n");
 764                         break;
 765                 }
 766
 767                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 768                 new_wsi->sock = accept_fd;
 769                 new_wsi->count_active_extensions = 0;
 770                 new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
 771
 772 #ifdef LWS_OPENSSL_SUPPORT
 773                 new_wsi->ssl = NULL;
 774
 775                 if (context->use_ssl) {
 776
 777                         new_wsi->ssl = SSL_new(context->ssl_ctx);
 778                         if (new_wsi->ssl == NULL) {
 779                                 fprintf(stderr, "SSL_new failed: %s\n",
 780                                     ERR_error_string(SSL_get_error(
 781                                     new_wsi->ssl, 0), NULL));
 782                                     libwebsockets_decode_ssl_error();
 783                                 free(new_wsi);
 784                                 break;
 785                         }
 786
 787                         SSL_set_fd(new_wsi->ssl, accept_fd);
 788
 789                         n = SSL_accept(new_wsi->ssl);
 790                         if (n != 1) {
 791                                 /*
 792                                  * browsers seem to probe with various
 793                                  * ssl params which fail then retry
 794                                  * and succeed
 795                                  */
 796                                 debug("SSL_accept failed skt %u: %s\n",
 797                                       pollfd->fd,
 798                                       ERR_error_string(SSL_get_error(
 799                                       new_wsi->ssl, n), NULL));
 800                                 SSL_free(
 801                                        new_wsi->ssl);
 802                                 free(new_wsi);
 803                                 break;
 804                         }
 805
 806                         debug("accepted new SSL conn  "
 807                               "port %u on fd=%d SSL ver %s\n",
 808                                 ntohs(cli_addr.sin_port), accept_fd,
 809                                   SSL_get_version(new_wsi->ssl));
 810
 811                 } else
 812 #endif
 813                         debug("accepted new conn  port %u on fd=%d\n",
 814                                           ntohs(cli_addr.sin_port), accept_fd);
 815
 816                 /* intialize the instance struct */
 817
 818                 new_wsi->state = WSI_STATE_HTTP;
 819                 new_wsi->name_buffer_pos = 0;
 820                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 821
 822                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 823                         new_wsi->utf8_token[n].token = NULL;
 824                         new_wsi->utf8_token[n].token_len = 0;
 825                 }
 826
 827                 /*
 828                  * these can only be set once the protocol is known
 829                  * we set an unestablished connection's protocol pointer
 830                  * to the start of the supported list, so it can look
 831                  * for matching ones during the handshake
 832                  */
 833                 new_wsi->protocol = context->protocols;
 834                 new_wsi->user_space = NULL;
 835
 836                 /*
 837                  * Default protocol is 76 / 00
 838                  * After 76, there's a header specified to inform which
 839                  * draft the client wants, when that's seen we modify
 840                  * the individual connection's spec revision accordingly
 841                  */
 842                 new_wsi->ietf_spec_revision = 0;
 843
 844                 insert_wsi(context, new_wsi);
 845
 846                 /*
 847                  * make sure NO events are seen yet on this new socket
 848                  * (otherwise we inherit old fds[client].revents from
 849                  * previous socket there and die mysteriously! )
 850                  */
 851                 context->fds[context->fds_count].revents = 0;
 852
 853                 context->fds[context->fds_count].events = POLLIN;
 854                 context->fds[context->fds_count++].fd = accept_fd;
 855
 856                 /* external POLL support via protocol 0 */
 857                 context->protocols[0].callback(context, new_wsi,
 858                         LWS_CALLBACK_ADD_POLL_FD,
 859                         (void *)(long)accept_fd, NULL, POLLIN);
 860
 861                 break;
 862
 863         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 864
 865                 /* as we are listening, POLLIN means accept() is needed */
 866
 867                 if (!pollfd->revents & POLLIN)
 868                         break;
 869
 870                 /* listen socket got an unencrypted connection... */
 871
 872                 clilen = sizeof(cli_addr);
 873                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 874                                                                        &clilen);
 875                 if (accept_fd < 0) {
 876                         fprintf(stderr, "ERROR on accept");
 877                         break;
 878                 }
 879
 880                 if (context->fds_count >= MAX_CLIENTS) {
 881                         fprintf(stderr, "too busy to accept new broadcast "
 882                                                               "proxy client\n");
 883 #ifdef WIN32
 884                         closesocket(accept_fd);
 885 #else
 886                         close(accept_fd);
 887 #endif
 888                         break;
 889                 }
 890
 891                 /* create a dummy wsi for the connection and add it */
 892
 893                 new_wsi = malloc(sizeof(struct libwebsocket));
 894                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 895                 new_wsi->sock = accept_fd;
 896                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 897                 new_wsi->state = WSI_STATE_ESTABLISHED;
 898                 new_wsi->count_active_extensions = 0;
 899                 /* note which protocol we are proxying */
 900                 new_wsi->protocol_index_for_broadcast_proxy =
 901                                         wsi->protocol_index_for_broadcast_proxy;
 902                 insert_wsi(context, new_wsi);
 903
 904                 /* add connected socket to internal poll array */
 905
 906                 context->fds[context->fds_count].revents = 0;
 907                 context->fds[context->fds_count].events = POLLIN;
 908                 context->fds[context->fds_count++].fd = accept_fd;
 909
 910                 /* external POLL support via protocol 0 */
 911                 context->protocols[0].callback(context, new_wsi,
 912                         LWS_CALLBACK_ADD_POLL_FD,
 913                         (void *)(long)accept_fd, NULL, POLLIN);
 914
 915                 break;
 916
 917         case LWS_CONNMODE_BROADCAST_PROXY:
 918
 919                 /* handle session socket closed */
 920
 921                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 922
 923                         debug("Session Socket %p (fd=%d) dead\n",
 924                                 (void *)wsi, pollfd->fd);
 925
 926                         libwebsocket_close_and_free_session(context, wsi,
 927                                                        LWS_CLOSE_STATUS_NORMAL);
 928                         return 1;
 929                 }
 930
 931                 /*
 932                  * either extension code with stuff to spill, or the user code,
 933                  * requested a callback when it was OK to write
 934                  */
 935
 936                 if (pollfd->revents & POLLOUT)
 937                         if (lws_handle_POLLOUT_event(context, wsi, pollfd) < 0) {
 938                                 libwebsocket_close_and_free_session(context, wsi,
 939                                                        LWS_CLOSE_STATUS_NORMAL);
 940                                 return 1;
 941                         }
 942
 943                 /* any incoming data ready? */
 944
 945                 if (!(pollfd->revents & POLLIN))
 946                         break;
 947
 948                 /* get the issued broadcast payload from the socket */
 949
 950                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 951                                                          MAX_BROADCAST_PAYLOAD);
 952                 if (len < 0) {
 953                         fprintf(stderr, "Error reading broadcast payload\n");
 954                         break;
 955                 }
 956
 957                 /* broadcast it to all guys with this protocol index */
 958
 959                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 960
 961                         for (m = 0; m < context->fd_hashtable[n].length; m++) {
 962
 963                                 new_wsi = context->fd_hashtable[n].wsi[m];
 964
 965                                 /* only to clients we are serving to */
 966
 967                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 968                                         continue;
 969
 970                                 /*
 971                                  * never broadcast to non-established
 972                                  * connection
 973                                  */
 974
 975                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 976                                         continue;
 977
 978                                 /*
 979                                  * only broadcast to connections using
 980                                  * the requested protocol
 981                                  */
 982
 983                                 if (new_wsi->protocol->protocol_index !=
 984                                         wsi->protocol_index_for_broadcast_proxy)
 985                                         continue;
 986
 987                                 /* broadcast it to this connection */
 988
 989                                 new_wsi->protocol->callback(context, new_wsi,
 990                                         LWS_CALLBACK_BROADCAST,
 991                                         new_wsi->user_space,
 992                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 993                         }
 994                 }
 995                 break;
 996
 997         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
 998
 999                 /* handle proxy hung up on us */
1000
1001                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1002
1003                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
1004                                 (void *)wsi, pollfd->fd);
1005
1006                         libwebsocket_close_and_free_session(context, wsi,
1007                                                      LWS_CLOSE_STATUS_NOSTATUS);
1008                         return 1;
1009                 }
1010
1011                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
1012                 if (n < 0) {
1013                         libwebsocket_close_and_free_session(context, wsi,
1014                                                      LWS_CLOSE_STATUS_NOSTATUS);
1015                         fprintf(stderr, "ERROR reading from proxy socket\n");
1016                         return 1;
1017                 }
1018
1019                 pkt[13] = '\0';
1020                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
1021                         libwebsocket_close_and_free_session(context, wsi,
1022                                                      LWS_CLOSE_STATUS_NOSTATUS);
1023                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
1024                         return 1;
1025                 }
1026
1027                 /* clear his proxy connection timeout */
1028
1029                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1030
1031                 /* fallthru */
1032
1033         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
1034
1035         #ifdef LWS_OPENSSL_SUPPORT
1036                 if (wsi->use_ssl) {
1037
1038                         wsi->ssl = SSL_new(context->ssl_client_ctx);
1039                         wsi->client_bio = BIO_new_socket(wsi->sock,
1040                                                                    BIO_NOCLOSE);
1041                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
1042
1043                         SSL_set_ex_data(wsi->ssl,
1044                                         openssl_websocket_private_data_index,
1045                                                                        context);
1046
1047                         if (SSL_connect(wsi->ssl) <= 0) {
1048                                 fprintf(stderr, "SSL connect error %s\n",
1049                                         ERR_error_string(ERR_get_error(),
1050                                                                   ssl_err_buf));
1051                                 libwebsocket_close_and_free_session(context, wsi,
1052                                                      LWS_CLOSE_STATUS_NOSTATUS);
1053                                 return 1;
1054                         }
1055
1056                         n = SSL_get_verify_result(wsi->ssl);
1057                         if ((n != X509_V_OK) && (
1058                                 n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
1059                                                            wsi->use_ssl != 2)) {
1060
1061                                 fprintf(stderr, "server's cert didn't "
1062                                                            "look good %d\n", n);
1063                                 libwebsocket_close_and_free_session(context,
1064                                                 wsi, LWS_CLOSE_STATUS_NOSTATUS);
1065                                 return 1;
1066                         }
1067                 } else {
1068                         wsi->ssl = NULL;
1069         #endif
1070
1071
1072         #ifdef LWS_OPENSSL_SUPPORT
1073                 }
1074         #endif
1075
1076                 /*
1077                  * create the random key
1078                  */
1079
1080                 n = libwebsockets_get_random(context, hash, 16);
1081                 if (n != 16) {
1082                         fprintf(stderr, "Unable to read from random dev %s\n",
1083                                                         SYSTEM_RANDOM_FILEPATH);
1084                         free(wsi->c_path);
1085                         free(wsi->c_host);
1086                         if (wsi->c_origin)
1087                                 free(wsi->c_origin);
1088                         if (wsi->c_protocol)
1089                                 free(wsi->c_protocol);
1090                         libwebsocket_close_and_free_session(context, wsi,
1091                                                      LWS_CLOSE_STATUS_NOSTATUS);
1092                         return 1;
1093                 }
1094
1095                 lws_b64_encode_string(hash, 16, wsi->key_b64,
1096                                                            sizeof wsi->key_b64);
1097
1098                 /*
1099                  * 00 example client handshake
1100                  *
1101                  * GET /socket.io/websocket HTTP/1.1
1102                  * Upgrade: WebSocket
1103                  * Connection: Upgrade
1104                  * Host: 127.0.0.1:9999
1105                  * Origin: http://127.0.0.1
1106                  * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7  92 ^
1107                  * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
1108                  * Cookie: socketio=websocket
1109                  *
1110                  * (Á®Ä0¶†≥
1111                  *
1112                  * 04 example client handshake
1113                  *
1114                  * GET /chat HTTP/1.1
1115                  * Host: server.example.com
1116                  * Upgrade: websocket
1117                  * Connection: Upgrade
1118                  * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
1119                  * Sec-WebSocket-Origin: http://example.com
1120                  * Sec-WebSocket-Protocol: chat, superchat
1121                  * Sec-WebSocket-Version: 4
1122                  */
1123
1124                 p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
1125
1126                 if (wsi->ietf_spec_revision == 0) {
1127                         unsigned char spaces_1, spaces_2;
1128                         unsigned int max_1, max_2;
1129                         unsigned int num_1, num_2;
1130                         unsigned long product_1, product_2;
1131                         char key_1[40];
1132                         char key_2[40];
1133                         unsigned int seed;
1134                         unsigned int count;
1135                         char challenge[16];
1136
1137                         libwebsockets_get_random(context, &spaces_1,
1138                                                                   sizeof(char));
1139                         libwebsockets_get_random(context, &spaces_2,
1140                                                                   sizeof(char));
1141
1142                         spaces_1 = (spaces_1 % 12) + 1;
1143                         spaces_2 = (spaces_2 % 12) + 1;
1144
1145                         max_1 = 4294967295 / spaces_1;
1146                         max_2 = 4294967295 / spaces_2;
1147
1148                         libwebsockets_get_random(context, &num_1, sizeof(int));
1149                         libwebsockets_get_random(context, &num_2, sizeof(int));
1150
1151                         num_1 = (num_1 % max_1);
1152                         num_2 = (num_2 % max_2);
1153
1154                         challenge[0] = num_1 >> 24;
1155                         challenge[1] = num_1 >> 16;
1156                         challenge[2] = num_1 >> 8;
1157                         challenge[3] = num_1;
1158                         challenge[4] = num_2 >> 24;
1159                         challenge[5] = num_2 >> 16;
1160                         challenge[6] = num_2 >> 8;
1161                         challenge[7] = num_2;
1162
1163                         product_1 = num_1 * spaces_1;
1164                         product_2 = num_2 * spaces_2;
1165
1166                         sprintf(key_1, "%lu", product_1);
1167                         sprintf(key_2, "%lu", product_2);
1168
1169                         libwebsockets_get_random(context, &seed, sizeof(int));
1170                         libwebsockets_get_random(context, &count, sizeof(int));
1171
1172                         libwebsockets_00_spam(key_1, (count % 12) + 1, seed);
1173
1174                         libwebsockets_get_random(context, &seed, sizeof(int));
1175                         libwebsockets_get_random(context, &count, sizeof(int));
1176
1177                         libwebsockets_00_spam(key_2, (count % 12) + 1, seed);
1178
1179                         libwebsockets_get_random(context, &seed, sizeof(int));
1180
1181                         libwebsockets_00_spaceout(key_1, spaces_1, seed);
1182                         libwebsockets_00_spaceout(key_2, spaces_2, seed >> 16);
1183
1184                         p += sprintf(p, "Upgrade: WebSocket\x0d\x0a"
1185                                 "Connection: Upgrade\x0d\x0aHost: %s\x0d\x0a",
1186                                 wsi->c_host);
1187                         if (wsi->c_origin)
1188                                 p += sprintf(p, "Origin: %s\x0d\x0a",
1189                                 wsi->c_origin);
1190
1191                         if (wsi->c_protocol)
1192                                 p += sprintf(p, "Sec-WebSocket-Protocol: %s"
1193                                                  "\x0d\x0a", wsi->c_protocol);
1194
1195                         p += sprintf(p, "Sec-WebSocket-Key1: %s\x0d\x0a",
1196                                 key_1);
1197                         p += sprintf(p, "Sec-WebSocket-Key2: %s\x0d\x0a",
1198                                 key_2);
1199
1200                         /* give userland a chance to append, eg, cookies */
1201
1202                         context->protocols[0].callback(context, wsi,
1203                                 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
1204                                         NULL, &p, (pkt + sizeof(pkt)) - p - 12);
1205
1206                         p += sprintf(p, "\x0d\x0a");
1207
1208                         if (libwebsockets_get_random(context, p, 8) != 8)
1209                                 return -1;
1210                         memcpy(&challenge[8], p, 8);
1211                         p += 8;
1212
1213                         /* precompute what we want to see from the server */
1214
1215                         MD5((unsigned char *)challenge, 16,
1216                            (unsigned char *)wsi->initial_handshake_hash_base64);
1217
1218                         goto issue_hdr;
1219                 }
1220
1221                 p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
1222                 p += sprintf(p, "Upgrade: websocket\x0d\x0a");
1223                 p += sprintf(p, "Connection: Upgrade\x0d\x0a"
1224                                         "Sec-WebSocket-Key: ");
1225                 strcpy(p, wsi->key_b64);
1226                 p += strlen(wsi->key_b64);
1227                 p += sprintf(p, "\x0d\x0a");
1228                 if (wsi->c_origin)
1229                         p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
1230                                                                  wsi->c_origin);
1231                 if (wsi->c_protocol)
1232                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
1233                                                                wsi->c_protocol);
1234
1235                 /* tell the server what extensions we could support */
1236
1237                 p += sprintf(p, "Sec-WebSocket-Extensions: ");
1238
1239                 ext =context->extensions;
1240                 while (ext && ext->callback) {
1241
1242                         n = 0;
1243                         n = context->protocols[0].callback(context, wsi,
1244                                 LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
1245                                         wsi->user_space, (char *)ext->name, 0);
1246
1247                         /*
1248                          * zero return from callback means
1249                          * go ahead and allow the extension,
1250                          * it's what we get if the callback is
1251                          * unhandled
1252                          */
1253
1254                         if (n) {
1255                                 ext++;
1256                                 continue;
1257                         }
1258
1259                         /* apply it */
1260
1261                         if (ext_count)
1262                                 *p++ = ',';
1263                         p += sprintf(p, "%s", ext->name);
1264                         ext_count++;
1265
1266                         ext++;
1267                 }
1268
1269                 p += sprintf(p, "\x0d\x0a");
1270
1271                 if (wsi->ietf_spec_revision)
1272                         p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
1273                                                        wsi->ietf_spec_revision);
1274
1275                 /* give userland a chance to append, eg, cookies */
1276
1277                 context->protocols[0].callback(context, wsi,
1278                         LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
1279                         NULL, &p, (pkt + sizeof(pkt)) - p - 12);
1280
1281                 p += sprintf(p, "\x0d\x0a");
1282
1283                 /* prepare the expected server accept response */
1284
1285                 strcpy((char *)buf, wsi->key_b64);
1286                 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
1287
1288                 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
1289
1290                 lws_b64_encode_string(hash, 20,
1291                                 wsi->initial_handshake_hash_base64,
1292                                      sizeof wsi->initial_handshake_hash_base64);
1293
1294 issue_hdr:
1295
1296                 /* done with these now */
1297
1298                 free(wsi->c_path);
1299                 free(wsi->c_host);
1300                 if (wsi->c_origin)
1301                         free(wsi->c_origin);
1302
1303                 /* send our request to the server */
1304
1305         #ifdef LWS_OPENSSL_SUPPORT
1306                 if (wsi->use_ssl)
1307                         n = SSL_write(wsi->ssl, pkt, p - pkt);
1308                 else
1309         #endif
1310                         n = send(wsi->sock, pkt, p - pkt, 0);
1311
1312                 if (n < 0) {
1313                         fprintf(stderr, "ERROR writing to client socket\n");
1314                         libwebsocket_close_and_free_session(context, wsi,
1315                                                      LWS_CLOSE_STATUS_NOSTATUS);
1316                         return 1;
1317                 }
1318
1319                 wsi->parser_state = WSI_TOKEN_NAME_PART;
1320                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
1321                 libwebsocket_set_timeout(wsi,
1322                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, 5);
1323
1324                 break;
1325
1326         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
1327
1328                 /* handle server hung up on us */
1329
1330                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1331
1332                         fprintf(stderr, "Server connection %p (fd=%d) dead\n",
1333                                 (void *)wsi, pollfd->fd);
1334
1335                         goto bail3;
1336                 }
1337
1338
1339                 /* interpret the server response */
1340
1341                 /*
1342                  *  HTTP/1.1 101 Switching Protocols
1343                  *  Upgrade: websocket
1344                  *  Connection: Upgrade
1345                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
1346                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
1347                  *  Sec-WebSocket-Protocol: chat
1348                  */
1349
1350         #ifdef LWS_OPENSSL_SUPPORT
1351                 if (wsi->use_ssl)
1352                         len = SSL_read(wsi->ssl, pkt, sizeof pkt);
1353                 else
1354         #endif
1355                         len = recv(wsi->sock, pkt, sizeof pkt, 0);
1356
1357                 if (len < 0) {
1358                         fprintf(stderr,
1359                                   "libwebsocket_client_handshake read error\n");
1360                         goto bail3;
1361                 }
1362
1363                 p = pkt;
1364                 for (n = 0; n < len; n++)
1365                         libwebsocket_parse(wsi, *p++);
1366
1367                 if (wsi->parser_state != WSI_PARSING_COMPLETE) {
1368                         fprintf(stderr, "libwebsocket_client_handshake "
1369                                         "server response failed parsing\n");
1370                         goto bail3;
1371                 }
1372
1373                 /*
1374                  * 00 / 76 -->
1375                  *
1376                  * HTTP/1.1 101 WebSocket Protocol Handshake
1377                  * Upgrade: WebSocket
1378                  * Connection: Upgrade
1379                  * Sec-WebSocket-Origin: http://127.0.0.1
1380                  * Sec-WebSocket-Location: ws://127.0.0.1:9999/socket.io/websocket
1381                  *
1382                  * xxxxxxxxxxxxxxxx
1383                  */
1384
1385                 if (wsi->ietf_spec_revision == 0) {
1386                         if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
1387                             !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
1388                             !wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len ||
1389                             !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
1390                             (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
1391                             wsi->c_protocol != NULL)) {
1392                                 fprintf(stderr, "libwebsocket_client_handshake "
1393                                                 "missing required header(s)\n");
1394                                 pkt[len] = '\0';
1395                                 fprintf(stderr, "%s", pkt);
1396                                 goto bail3;
1397                         }
1398
1399                         strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
1400                         if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
1401                                 "101 websocket protocol handshake")) {
1402                                 fprintf(stderr, "libwebsocket_client_handshake "
1403                                         "server sent bad HTTP response '%s'\n",
1404                                         wsi->utf8_token[WSI_TOKEN_HTTP].token);
1405                                 goto bail3;
1406                         }
1407
1408                         if (wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len <
1409                                                                            16) {
1410                                 fprintf(stderr, "libwebsocket_client_handshake "
1411                                         "challenge reply too short %d\n",
1412                                         wsi->utf8_token[
1413                                                 WSI_TOKEN_CHALLENGE].token_len);
1414                                 pkt[len] = '\0';
1415                                 fprintf(stderr, "%s", pkt);
1416                                 goto bail3;
1417
1418                         }
1419
1420                         goto select_protocol;
1421                 }
1422
1423                 /*
1424                  * well, what the server sent looked reasonable for syntax.
1425                  * Now let's confirm it sent all the necessary headers
1426                  */
1427
1428                  if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
1429                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
1430                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
1431                         !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
1432                         (!wsi->utf8_token[WSI_TOKEN_NONCE].token_len &&
1433                                            wsi->ietf_spec_revision == 4) ||
1434                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
1435                                                      wsi->c_protocol != NULL)) {
1436                         fprintf(stderr, "libwebsocket_client_handshake "
1437                                                 "missing required header(s)\n");
1438                         pkt[len] = '\0';
1439                         fprintf(stderr, "%s", pkt);
1440                         goto bail3;
1441                 }
1442
1443                 /*
1444                  * Everything seems to be there, now take a closer look at what
1445                  * is in each header
1446                  */
1447
1448                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
1449                 if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
1450                                                    "101 switching protocols")) {
1451                         fprintf(stderr, "libwebsocket_client_handshake "
1452                                         "server sent bad HTTP response '%s'\n",
1453                                          wsi->utf8_token[WSI_TOKEN_HTTP].token);
1454                         goto bail3;
1455                 }
1456
1457                 strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
1458                 if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
1459                                                                  "websocket")) {
1460                         fprintf(stderr, "libwebsocket_client_handshake server "
1461                                         "sent bad Upgrade header '%s'\n",
1462                                       wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
1463                         goto bail3;
1464                 }
1465
1466                 strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
1467                 if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
1468                                                                    "upgrade")) {
1469                         fprintf(stderr, "libwebsocket_client_handshake server "
1470                                         "sent bad Connection hdr '%s'\n",
1471                                    wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
1472                         goto bail3;
1473                 }
1474
1475 select_protocol:
1476                 pc = wsi->c_protocol;
1477
1478                 /*
1479                  * confirm the protocol the server wants to talk was in the list
1480                  * of protocols we offered
1481                  */
1482
1483                 if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
1484
1485                         /*
1486                          * no protocol name to work from,
1487                          * default to first protocol
1488                          */
1489                         wsi->protocol = &context->protocols[0];
1490
1491                         free(wsi->c_protocol);
1492
1493                         goto check_accept;
1494                 }
1495
1496                 while (*pc && !okay) {
1497                         if ((!strncmp(pc,
1498                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
1499                            wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
1500                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
1501                    pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
1502                                 okay = 1;
1503                                 continue;
1504                         }
1505                         while (*pc && *pc != ',')
1506                                 pc++;
1507                         while (*pc && *pc != ' ')
1508                                 pc++;
1509                 }
1510
1511                 /* done with him now */
1512
1513                 if (wsi->c_protocol)
1514                         free(wsi->c_protocol);
1515
1516
1517                 if (!okay) {
1518                         fprintf(stderr, "libwebsocket_client_handshake server "
1519                                                 "sent bad protocol '%s'\n",
1520                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
1521                         goto bail2;
1522                 }
1523
1524                 /*
1525                  * identify the selected protocol struct and set it
1526                  */
1527                 n = 0;
1528                 wsi->protocol = NULL;
1529                 while (context->protocols[n].callback) {
1530                         if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
1531                                                context->protocols[n].name) == 0)
1532                                 wsi->protocol = &context->protocols[n];
1533                         n++;
1534                 }
1535
1536                 if (wsi->protocol == NULL) {
1537                         fprintf(stderr, "libwebsocket_client_handshake server "
1538                                         "requested protocol '%s', which we "
1539                                         "said we supported but we don't!\n",
1540                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
1541                         goto bail2;
1542                 }
1543
1544
1545                 /* instantiate the accepted extensions */
1546
1547                 if (!wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token_len)
1548                         goto check_accept;
1549
1550                 /*
1551                  * break down the list of server accepted extensions
1552                  * and go through matching them or identifying bogons
1553                  */
1554
1555                 c = wsi->utf8_token[WSI_TOKEN_EXTENSIONS].token;
1556                 n = 0;
1557                 while (more) {
1558
1559                         if (*c && *c != ',') {
1560                                 ext_name[n] = *c++;
1561                                 if (n < sizeof(ext_name) - 1)
1562                                         n++;
1563                                 continue;
1564                         }
1565                         ext_name[n] = '\0';
1566                         if (!*c)
1567                                 more = 0;
1568
1569                         /* check we actually support it */
1570
1571                         n = 0;
1572                         ext = wsi->protocol->owning_server->extensions;
1573                         while (ext && ext->callback) {
1574
1575                                 if (strcmp(ext_name, ext->name)) {
1576                                         ext++;
1577                                         continue;
1578                                 }
1579
1580                                 n = 1;
1581
1582                                 /* instantiate the extension on this conn */
1583
1584                                 wsi->active_extensions_user[
1585                                         wsi->count_active_extensions] =
1586                                              malloc(ext->per_session_data_size);
1587                                 wsi->active_extensions[
1588                                           wsi->count_active_extensions] = ext;
1589
1590                                 /* allow him to construct his context */
1591
1592                                 ext->callback(wsi->protocol->owning_server,
1593                                         ext, wsi,
1594                                            LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
1595                                                 wsi->active_extensions_user[
1596                                                  wsi->count_active_extensions],
1597                                                                        NULL, 0);
1598
1599                                 wsi->count_active_extensions++;
1600
1601                                 ext++;
1602                         }
1603
1604                         if (n == 0) {
1605                                 fprintf(stderr, "Server said we should use"
1606                                       "an unknown extension '%s'!\n", ext_name);
1607                                 goto bail2;
1608                         }
1609
1610                         n = 0;
1611                 }
1612
1613
1614         check_accept:
1615
1616                 if (wsi->ietf_spec_revision == 0) {
1617
1618                         if (memcmp(wsi->initial_handshake_hash_base64,
1619                               wsi->utf8_token[WSI_TOKEN_CHALLENGE].token, 16)) {
1620                                 fprintf(stderr, "libwebsocket_client_handshake "
1621                                                "failed 00 challenge compare\n");
1622                                         pkt[len] = '\0';
1623                                         fprintf(stderr, "%s", pkt);
1624                                         goto bail2;
1625                         }
1626
1627                         goto accept_ok;
1628                 }
1629
1630                 /*
1631                  * Confirm his accept token is the one we precomputed
1632                  */
1633
1634                 if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1635                                           wsi->initial_handshake_hash_base64)) {
1636                         fprintf(stderr, "libwebsocket_client_handshake server "
1637                                 "sent bad ACCEPT '%s' vs computed '%s'\n",
1638                                 wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1639                                             wsi->initial_handshake_hash_base64);
1640                         goto bail2;
1641                 }
1642
1643                 if (wsi->ietf_spec_revision == 4) {
1644                         /*
1645                          * Calculate the 04 masking key to use when
1646                          * sending data to server
1647                          */
1648
1649                         strcpy((char *)buf, wsi->key_b64);
1650                         p = (char *)buf + strlen(wsi->key_b64);
1651                         strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1652                         p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1653                         strcpy(p, magic_websocket_04_masking_guid);
1654                         SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1655                 }
1656 accept_ok:
1657
1658                 /* allocate the per-connection user memory (if any) */
1659
1660                 if (wsi->protocol->per_session_data_size) {
1661                         wsi->user_space = malloc(
1662                                           wsi->protocol->per_session_data_size);
1663                         if (wsi->user_space  == NULL) {
1664                                 fprintf(stderr, "Out of memory for "
1665                                                            "conn user space\n");
1666                                 goto bail2;
1667                         }
1668                 } else
1669                         wsi->user_space = NULL;
1670
1671                 /* clear his proxy connection timeout */
1672
1673                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1674
1675                 /* mark him as being alive */
1676
1677                 wsi->state = WSI_STATE_ESTABLISHED;
1678                 wsi->mode = LWS_CONNMODE_WS_CLIENT;
1679
1680                 fprintf(stderr, "handshake OK for protocol %s\n",
1681                                                            wsi->protocol->name);
1682
1683                 /* call him back to inform him he is up */
1684
1685                 wsi->protocol->callback(context, wsi,
1686                                  LWS_CALLBACK_CLIENT_ESTABLISHED,
1687                                  wsi->user_space,
1688                                  NULL, 0);
1689
1690                 break;
1691
1692 bail3:
1693                 if (wsi->c_protocol)
1694                         free(wsi->c_protocol);
1695
1696 bail2:
1697                 libwebsocket_close_and_free_session(context, wsi,
1698                                                      LWS_CLOSE_STATUS_NOSTATUS);
1699                 return 1;
1700
1701
1702         case LWS_CONNMODE_WS_SERVING:
1703         case LWS_CONNMODE_WS_CLIENT:
1704
1705                 /* handle session socket closed */
1706
1707                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1708
1709                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1710                                 (void *)wsi, pollfd->fd);
1711
1712                         libwebsocket_close_and_free_session(context, wsi,
1713                                                      LWS_CLOSE_STATUS_NOSTATUS);
1714                         return 1;
1715                 }
1716
1717                 /* the guy requested a callback when it was OK to write */
1718
1719                 if ((pollfd->revents & POLLOUT) &&
1720                                             wsi->state == WSI_STATE_ESTABLISHED)
1721                         if (lws_handle_POLLOUT_event(context, wsi,
1722                                                                   pollfd) < 0) {
1723                                 libwebsocket_close_and_free_session(
1724                                          context, wsi, LWS_CLOSE_STATUS_NORMAL);
1725                                 return 1;
1726                         }
1727
1728
1729                 /* any incoming data ready? */
1730
1731                 if (!(pollfd->revents & POLLIN))
1732                         break;
1733
1734 #ifdef LWS_OPENSSL_SUPPORT
1735                 if (wsi->ssl)
1736                         eff_buf.token_len = SSL_read(wsi->ssl, buf, sizeof buf);
1737                 else
1738 #endif
1739                         eff_buf.token_len =
1740                                            recv(pollfd->fd, buf, sizeof buf, 0);
1741
1742                 if (eff_buf.token_len < 0) {
1743                         fprintf(stderr, "Socket read returned %d\n",
1744                                                             eff_buf.token_len);
1745                         break;
1746                 }
1747                 if (!eff_buf.token_len) {
1748                         libwebsocket_close_and_free_session(context, wsi,
1749                                                      LWS_CLOSE_STATUS_NOSTATUS);
1750                         return 1;
1751                 }
1752
1753                 /*
1754                  * give any active extensions a chance to munge the buffer
1755                  * before parse.  We pass in a pointer to an lws_tokens struct
1756                  * prepared with the default buffer and content length that's in
1757                  * there.  Rather than rewrite the default buffer, extensions
1758                  * that expect to grow the buffer can adapt .token to
1759                  * point to their own per-connection buffer in the extension
1760                  * user allocation.  By default with no extensions or no
1761                  * extension callback handling, just the normal input buffer is
1762                  * used then so it is efficient.
1763                  */
1764
1765                 eff_buf.token = (char *)buf;
1766
1767                 more = 1;
1768                 while (more) {
1769
1770                         more = 0;
1771
1772                         for (n = 0; n < wsi->count_active_extensions; n++) {
1773                                 m = wsi->active_extensions[n]->callback(context,
1774                                         wsi->active_extensions[n], wsi,
1775                                         LWS_EXT_CALLBACK_PACKET_RX_PREPARSE,
1776                                         wsi->active_extensions_user[n],
1777                                                                    &eff_buf, 0);
1778                                 if (m < 0) {
1779                                         fprintf(stderr, "Extension reports fatal error\n");
1780                                         libwebsocket_close_and_free_session(context, wsi,
1781                                                              LWS_CLOSE_STATUS_NOSTATUS);
1782                                         return 1;
1783                                 }
1784                                 if (m)
1785                                         more = 1;
1786                         }
1787
1788                         /* service incoming data */
1789
1790                         if (eff_buf.token_len) {
1791                                 n = libwebsocket_read(context, wsi,
1792                                      (unsigned char *)eff_buf.token, eff_buf.token_len);
1793                                 if (n < 0)
1794                                         /* we closed wsi */
1795                                         return 1;
1796                         }
1797
1798                         eff_buf.token = NULL;
1799                         eff_buf.token_len = 0;
1800                 }
1801                 break;
1802         }
1803
1804         return 0;
1805 }
1806
1807
1808 /**
1809  * libwebsocket_context_destroy() - Destroy the websocket context
1810  * @context:    Websocket context
1811  *
1812  *      This function closes any active connections and then frees the
1813  *      context.  After calling this, any further use of the context is
1814  *      undefined.
1815  */
1816 void
1817 libwebsocket_context_destroy(struct libwebsocket_context *context)
1818 {
1819         int n;
1820         int m;
1821         struct libwebsocket *wsi;
1822
1823         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1824                 for (m = 0; m < context->fd_hashtable[n].length; m++) {
1825                         wsi = context->fd_hashtable[n].wsi[m];
1826                         libwebsocket_close_and_free_session(context, wsi,
1827                                                     LWS_CLOSE_STATUS_GOINGAWAY);
1828                 }
1829
1830 #ifdef WIN32
1831 #else
1832         close(context->fd_random);
1833 #endif
1834
1835 #ifdef LWS_OPENSSL_SUPPORT
1836         if (context->ssl_ctx)
1837                 SSL_CTX_free(context->ssl_ctx);
1838         if (context->ssl_client_ctx)
1839                 SSL_CTX_free(context->ssl_client_ctx);
1840 #endif
1841
1842         free(context);
1843
1844 #ifdef WIN32
1845         WSACleanup();
1846 #endif
1847 }
1848
1849 /**
1850  * libwebsocket_service() - Service any pending websocket activity
1851  * @context:    Websocket context
1852  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
1853  *              service otherwise block and service immediately, returning
1854  *              after the timeout if nothing needed service.
1855  *
1856  *      This function deals with any pending websocket traffic, for three
1857  *      kinds of event.  It handles these events on both server and client
1858  *      types of connection the same.
1859  *
1860  *      1) Accept new connections to our context's server
1861  *
1862  *      2) Perform pending broadcast writes initiated from other forked
1863  *         processes (effectively serializing asynchronous broadcasts)
1864  *
1865  *      3) Call the receive callback for incoming frame data received by
1866  *          server or client connections.
1867  *
1868  *      You need to call this service function periodically to all the above
1869  *      functions to happen; if your application is single-threaded you can
1870  *      just call it in your main event loop.
1871  *
1872  *      Alternatively you can fork a new process that asynchronously handles
1873  *      calling this service in a loop.  In that case you are happy if this
1874  *      call blocks your thread until it needs to take care of something and
1875  *      would call it with a large nonzero timeout.  Your loop then takes no
1876  *      CPU while there is nothing happening.
1877  *
1878  *      If you are calling it in a single-threaded app, you don't want it to
1879  *      wait around blocking other things in your loop from happening, so you
1880  *      would call it with a timeout_ms of 0, so it returns immediately if
1881  *      nothing is pending, or as soon as it services whatever was pending.
1882  */
1883
1884
1885 int
1886 libwebsocket_service(struct libwebsocket_context *context, int timeout_ms)
1887 {
1888         int n;
1889
1890         /* stay dead once we are dead */
1891
1892         if (context == NULL)
1893                 return 1;
1894
1895         /* wait for something to need service */
1896
1897         n = poll(context->fds, context->fds_count, timeout_ms);
1898         if (n == 0) /* poll timeout */
1899                 return 0;
1900
1901         if (n < 0) {
1902                 /*
1903                 fprintf(stderr, "Listen Socket dead\n");
1904                 */
1905                 return 1;
1906         }
1907
1908         /* handle accept on listening socket? */
1909
1910         for (n = 0; n < context->fds_count; n++)
1911                 if (context->fds[n].revents)
1912                         libwebsocket_service_fd(context, &context->fds[n]);
1913
1914         return 0;
1915 }
1916
1917 /**
1918  * libwebsocket_callback_on_writable() - Request a callback when this socket
1919  *                                       becomes able to be written to without
1920  *                                       blocking
1921  *
1922  * @context:    libwebsockets context
1923  * @wsi:        Websocket connection instance to get callback for
1924  */
1925
1926 int
1927 libwebsocket_callback_on_writable(struct libwebsocket_context *context,
1928                                                        struct libwebsocket *wsi)
1929 {
1930         int n;
1931
1932         for (n = 0; n < context->fds_count; n++)
1933                 if (context->fds[n].fd == wsi->sock) {
1934                         context->fds[n].events |= POLLOUT;
1935                         n = context->fds_count;
1936                 }
1937
1938         /* external POLL support via protocol 0 */
1939         context->protocols[0].callback(context, wsi,
1940                 LWS_CALLBACK_SET_MODE_POLL_FD,
1941                 (void *)(long)wsi->sock, NULL, POLLOUT);
1942
1943         return 1;
1944 }
1945
1946 /**
1947  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
1948  *                      all connections using the given protocol when it
1949  *                      becomes possible to write to each socket without
1950  *                      blocking in turn.
1951  *
1952  * @protocol:   Protocol whose connections will get callbacks
1953  */
1954
1955 int
1956 libwebsocket_callback_on_writable_all_protocol(
1957                                   const struct libwebsocket_protocols *protocol)
1958 {
1959         struct libwebsocket_context *context = protocol->owning_server;
1960         int n;
1961         int m;
1962         struct libwebsocket *wsi;
1963
1964         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1965
1966                 for (m = 0; m < context->fd_hashtable[n].length; m++) {
1967
1968                         wsi = context->fd_hashtable[n].wsi[m];
1969
1970                         if (wsi->protocol == protocol)
1971                                 libwebsocket_callback_on_writable(context, wsi);
1972                 }
1973         }
1974
1975         return 0;
1976 }
1977
1978 /**
1979  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
1980  *
1981  * You will not need this unless you are doing something special
1982  *
1983  * @wsi:        Websocket connection instance
1984  * @reason:     timeout reason
1985  * @secs:       how many seconds
1986  */
1987
1988 void
1989 libwebsocket_set_timeout(struct libwebsocket *wsi,
1990                                           enum pending_timeout reason, int secs)
1991 {
1992         struct timeval tv;
1993
1994         gettimeofday(&tv, NULL);
1995
1996         wsi->pending_timeout_limit = tv.tv_sec + secs;
1997         wsi->pending_timeout = reason;
1998 }
1999
2000
2001 /**
2002  * libwebsocket_get_socket_fd() - returns the socket file descriptor
2003  *
2004  * You will not need this unless you are doing something special
2005  *
2006  * @wsi:        Websocket connection instance
2007  */
2008
2009 int
2010 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
2011 {
2012         return wsi->sock;
2013 }
2014
2015 /**
2016  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
2017  *                              receieved packets.
2018  *
2019  * If the output side of a server process becomes choked, this allows flow
2020  * control for the input side.
2021  *
2022  * @wsi:        Websocket connection instance to get callback for
2023  * @enable:     0 = disable read servicing for this connection, 1 = enable
2024  */
2025
2026 int
2027 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
2028 {
2029         struct libwebsocket_context *context = wsi->protocol->owning_server;
2030         int n;
2031
2032         for (n = 0; n < context->fds_count; n++)
2033                 if (context->fds[n].fd == wsi->sock) {
2034                         if (enable)
2035                                 context->fds[n].events |= POLLIN;
2036                         else
2037                                 context->fds[n].events &= ~POLLIN;
2038
2039                         return 0;
2040                 }
2041
2042         if (enable)
2043                 /* external POLL support via protocol 0 */
2044                 context->protocols[0].callback(context, wsi,
2045                         LWS_CALLBACK_SET_MODE_POLL_FD,
2046                         (void *)(long)wsi->sock, NULL, POLLIN);
2047         else
2048                 /* external POLL support via protocol 0 */
2049                 context->protocols[0].callback(context, wsi,
2050                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
2051                         (void *)(long)wsi->sock, NULL, POLLIN);
2052
2053
2054         fprintf(stderr, "libwebsocket_callback_on_writable "
2055                                                      "unable to find socket\n");
2056         return 1;
2057 }
2058
2059 /**
2060  * libwebsocket_canonical_hostname() - returns this host's hostname
2061  *
2062  * This is typically used by client code to fill in the host parameter
2063  * when making a client connection.  You can only call it after the context
2064  * has been created.
2065  *
2066  * @context:    Websocket context
2067  */
2068
2069
2070 extern const char *
2071 libwebsocket_canonical_hostname(struct libwebsocket_context *context)
2072 {
2073         return (const char *)context->canonical_hostname;
2074 }
2075
2076
2077 static void sigpipe_handler(int x)
2078 {
2079 }
2080
2081 #ifdef LWS_OPENSSL_SUPPORT
2082 static int
2083 OpenSSL_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
2084 {
2085
2086         SSL *ssl;
2087         int n;
2088         struct libwebsocket_context *context;
2089
2090         ssl = X509_STORE_CTX_get_ex_data(x509_ctx,
2091                 SSL_get_ex_data_X509_STORE_CTX_idx());
2092
2093         /*
2094          * !!! nasty openssl requires the index to come as a library-scope
2095          * static
2096          */
2097         context = SSL_get_ex_data(ssl, openssl_websocket_private_data_index);
2098
2099         n = context->protocols[0].callback(NULL, NULL,
2100                 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
2101                                                    x509_ctx, ssl, preverify_ok);
2102
2103         /* convert return code from 0 = OK to 1 = OK */
2104
2105         if (!n)
2106                 n = 1;
2107         else
2108                 n = 0;
2109
2110         return n;
2111 }
2112 #endif
2113
2114
2115 /**
2116  * libwebsocket_create_context() - Create the websocket handler
2117  * @port:       Port to listen on... you can use 0 to suppress listening on
2118  *              any port, that's what you want if you are not running a
2119  *              websocket server at all but just using it as a client
2120  * @interf:  NULL to bind the listen socket to all interfaces, or the
2121  *              interface name, eg, "eth2"
2122  * @protocols:  Array of structures listing supported protocols and a protocol-
2123  *              specific callback for each one.  The list is ended with an
2124  *              entry that has a NULL callback pointer.
2125  *              It's not const because we write the owning_server member
2126  * @extensions: NULL or array of libwebsocket_extension structs listing the
2127  *              extensions this context supports
2128  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
2129  *                      to listen using SSL, set to the filepath to fetch the
2130  *                      server cert from, otherwise NULL for unencrypted
2131  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
2132  *                      else ignored
2133  * @gid:        group id to change to after setting listen socket, or -1.
2134  * @uid:        user id to change to after setting listen socket, or -1.
2135  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
2136  *
2137  *      This function creates the listening socket and takes care
2138  *      of all initialization in one step.
2139  *
2140  *      After initialization, it returns a struct libwebsocket_context * that
2141  *      represents this server.  After calling, user code needs to take care
2142  *      of calling libwebsocket_service() with the context pointer to get the
2143  *      server's sockets serviced.  This can be done in the same process context
2144  *      or a forked process, or another thread,
2145  *
2146  *      The protocol callback functions are called for a handful of events
2147  *      including http requests coming in, websocket connections becoming
2148  *      established, and data arriving; it's also called periodically to allow
2149  *      async transmission.
2150  *
2151  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
2152  *      at that time websocket protocol has not been negotiated.  Other
2153  *      protocols after the first one never see any HTTP callack activity.
2154  *
2155  *      The server created is a simple http server by default; part of the
2156  *      websocket standard is upgrading this http connection to a websocket one.
2157  *
2158  *      This allows the same server to provide files like scripts and favicon /
2159  *      images or whatever over http and dynamic data over websockets all in
2160  *      one place; they're all handled in the user callback.
2161  */
2162
2163 struct libwebsocket_context *
2164 libwebsocket_create_context(int port, const char *interf,
2165                                struct libwebsocket_protocols *protocols,
2166                                struct libwebsocket_extension *extensions,
2167                                const char *ssl_cert_filepath,
2168                                const char *ssl_private_key_filepath,
2169                                int gid, int uid, unsigned int options)
2170 {
2171         int n;
2172         int sockfd = 0;
2173         int fd;
2174         struct sockaddr_in serv_addr, cli_addr;
2175         int opt = 1;
2176         struct libwebsocket_context *context = NULL;
2177         unsigned int slen;
2178         char *p;
2179         char hostname[1024];
2180         struct hostent *he;
2181         struct libwebsocket *wsi;
2182
2183 #ifdef LWS_OPENSSL_SUPPORT
2184         SSL_METHOD *method;
2185         char ssl_err_buf[512];
2186 #endif
2187
2188 #ifdef _WIN32
2189         {
2190                 WORD wVersionRequested;
2191                 WSADATA wsaData;
2192                 int err;
2193
2194                 /* Use the MAKEWORD(lowbyte, highbyte) macro from Windef.h */
2195                 wVersionRequested = MAKEWORD(2, 2);
2196
2197                 err = WSAStartup(wVersionRequested, &wsaData);
2198                 if (err != 0) {
2199                         /* Tell the user that we could not find a usable */
2200                         /* Winsock DLL.                                  */
2201                         fprintf(stderr, "WSAStartup failed with error: %d\n",
2202                                                                            err);
2203                         return NULL;
2204                 }
2205         }
2206 #endif
2207
2208
2209         context = malloc(sizeof(struct libwebsocket_context));
2210         if (!context) {
2211                 fprintf(stderr, "No memory for websocket context\n");
2212                 return NULL;
2213         }
2214         context->protocols = protocols;
2215         context->listen_port = port;
2216         context->http_proxy_port = 0;
2217         context->http_proxy_address[0] = '\0';
2218         context->options = options;
2219         context->fds_count = 0;
2220         context->extensions = extensions;
2221
2222 #ifdef WIN32
2223         context->fd_random = 0;
2224 #else
2225         context->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
2226         if (context->fd_random < 0) {
2227                 fprintf(stderr, "Unable to open random device %s %d\n",
2228                                     SYSTEM_RANDOM_FILEPATH, context->fd_random);
2229                 return NULL;
2230         }
2231 #endif
2232
2233 #ifdef LWS_OPENSSL_SUPPORT
2234         context->use_ssl = 0;
2235         context->ssl_ctx = NULL;
2236         context->ssl_client_ctx = NULL;
2237         openssl_websocket_private_data_index = 0;
2238 #endif
2239         /* find canonical hostname */
2240
2241         hostname[(sizeof hostname) - 1] = '\0';
2242         gethostname(hostname, (sizeof hostname) - 1);
2243         he = gethostbyname(hostname);
2244         if (he) {
2245                 strncpy(context->canonical_hostname, he->h_name,
2246                                         sizeof context->canonical_hostname - 1);
2247                 context->canonical_hostname[
2248                                 sizeof context->canonical_hostname - 1] = '\0';
2249         } else
2250                 strncpy(context->canonical_hostname, hostname,
2251                                         sizeof context->canonical_hostname - 1);
2252
2253         /* split the proxy ads:port if given */
2254
2255         p = getenv("http_proxy");
2256         if (p) {
2257                 strncpy(context->http_proxy_address, p,
2258                                         sizeof context->http_proxy_address - 1);
2259                 context->http_proxy_address[
2260                                  sizeof context->http_proxy_address - 1] = '\0';
2261
2262                 p = strchr(context->http_proxy_address, ':');
2263                 if (p == NULL) {
2264                         fprintf(stderr, "http_proxy needs to be ads:port\n");
2265                         return NULL;
2266                 }
2267                 *p = '\0';
2268                 context->http_proxy_port = atoi(p + 1);
2269
2270                 fprintf(stderr, "Using proxy %s:%u\n",
2271                                 context->http_proxy_address,
2272                                                       context->http_proxy_port);
2273         }
2274
2275         if (port) {
2276
2277 #ifdef LWS_OPENSSL_SUPPORT
2278                 context->use_ssl = ssl_cert_filepath != NULL &&
2279                                                ssl_private_key_filepath != NULL;
2280                 if (context->use_ssl)
2281                         fprintf(stderr, " Compiled with SSL support, "
2282                                                                   "using it\n");
2283                 else
2284                         fprintf(stderr, " Compiled with SSL support, "
2285                                                               "not using it\n");
2286
2287 #else
2288                 if (ssl_cert_filepath != NULL &&
2289                                              ssl_private_key_filepath != NULL) {
2290                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
2291                         return NULL;
2292                 }
2293                 fprintf(stderr, " Compiled without SSL support, "
2294                                                        "serving unencrypted\n");
2295 #endif
2296         }
2297
2298         /* ignore SIGPIPE */
2299 #ifdef WIN32
2300 #else
2301         signal(SIGPIPE, sigpipe_handler);
2302 #endif
2303
2304
2305 #ifdef LWS_OPENSSL_SUPPORT
2306
2307         /* basic openssl init */
2308
2309         SSL_library_init();
2310
2311         OpenSSL_add_all_algorithms();
2312         SSL_load_error_strings();
2313
2314         openssl_websocket_private_data_index =
2315                 SSL_get_ex_new_index(0, "libwebsockets", NULL, NULL, NULL);
2316
2317         /*
2318          * Firefox insists on SSLv23 not SSLv3
2319          * Konq disables SSLv2 by default now, SSLv23 works
2320          */
2321
2322         method = (SSL_METHOD *)SSLv23_server_method();
2323         if (!method) {
2324                 fprintf(stderr, "problem creating ssl method: %s\n",
2325                         ERR_error_string(ERR_get_error(), ssl_err_buf));
2326                 return NULL;
2327         }
2328         context->ssl_ctx = SSL_CTX_new(method); /* create context */
2329         if (!context->ssl_ctx) {
2330                 fprintf(stderr, "problem creating ssl context: %s\n",
2331                         ERR_error_string(ERR_get_error(), ssl_err_buf));
2332                 return NULL;
2333         }
2334
2335         /* client context */
2336         if (port == CONTEXT_PORT_NO_LISTEN)
2337         {
2338                 method = (SSL_METHOD *)SSLv23_client_method();
2339                 if (!method) {
2340                         fprintf(stderr, "problem creating ssl method: %s\n",
2341                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2342                         return NULL;
2343                 }
2344                 /* create context */
2345                 context->ssl_client_ctx = SSL_CTX_new(method);
2346                 if (!context->ssl_client_ctx) {
2347                         fprintf(stderr, "problem creating ssl context: %s\n",
2348                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2349                         return NULL;
2350                 }
2351
2352                 /* openssl init for cert verification (for client sockets) */
2353
2354                 if (!SSL_CTX_load_verify_locations(
2355                                         context->ssl_client_ctx, NULL,
2356                                                       LWS_OPENSSL_CLIENT_CERTS))
2357                         fprintf(stderr,
2358                             "Unable to load SSL Client certs from %s "
2359                             "(set by --with-client-cert-dir= in configure) -- "
2360                                 " client ssl isn't going to work",
2361                                                       LWS_OPENSSL_CLIENT_CERTS);
2362
2363                 /*
2364                  * callback allowing user code to load extra verification certs
2365                  * helping the client to verify server identity
2366                  */
2367
2368                 context->protocols[0].callback(context, NULL,
2369                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
2370                         context->ssl_client_ctx, NULL, 0);
2371         }
2372         /* as a server, are we requiring clients to identify themselves? */
2373
2374         if (options & LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT) {
2375
2376                 /* absolutely require the client cert */
2377
2378                 SSL_CTX_set_verify(context->ssl_ctx,
2379                        SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
2380                                                        OpenSSL_verify_callback);
2381
2382                 /*
2383                  * give user code a chance to load certs into the server
2384                  * allowing it to verify incoming client certs
2385                  */
2386
2387                 context->protocols[0].callback(context, NULL,
2388                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
2389                                                      context->ssl_ctx, NULL, 0);
2390         }
2391
2392         if (context->use_ssl) {
2393
2394                 /* openssl init for server sockets */
2395
2396                 /* set the local certificate from CertFile */
2397                 n = SSL_CTX_use_certificate_file(context->ssl_ctx,
2398                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
2399                 if (n != 1) {
2400                         fprintf(stderr, "problem getting cert '%s': %s\n",
2401                                 ssl_cert_filepath,
2402                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2403                         return NULL;
2404                 }
2405                 /* set the private key from KeyFile */
2406                 if (SSL_CTX_use_PrivateKey_file(context->ssl_ctx,
2407                              ssl_private_key_filepath, SSL_FILETYPE_PEM) != 1) {
2408                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
2409                                                 ssl_private_key_filepath,
2410                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
2411                         return NULL;
2412                 }
2413                 /* verify private key */
2414                 if (!SSL_CTX_check_private_key(context->ssl_ctx)) {
2415                         fprintf(stderr, "Private SSL key doesn't match cert\n");
2416                         return NULL;
2417                 }
2418
2419                 /* SSL is happy and has a cert it's content with */
2420         }
2421 #endif
2422
2423         /* selftest */
2424
2425         if (lws_b64_selftest())
2426                 return NULL;
2427
2428         /* fd hashtable init */
2429
2430         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
2431                 context->fd_hashtable[n].length = 0;
2432
2433         /* set up our external listening socket we serve on */
2434
2435         if (port) {
2436
2437                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
2438                 if (sockfd < 0) {
2439                         fprintf(stderr, "ERROR opening socket");
2440                         return NULL;
2441                 }
2442
2443                 /* allow us to restart even if old sockets in TIME_WAIT */
2444                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
2445
2446
2447                 /* Disable Nagle */
2448                 opt = 1;
2449                 setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt));
2450
2451                 bzero((char *) &serv_addr, sizeof(serv_addr));
2452                 serv_addr.sin_family = AF_INET;
2453                 if (interf == NULL)
2454                         serv_addr.sin_addr.s_addr = INADDR_ANY;
2455                 else
2456                         interface_to_sa(interf, &serv_addr,
2457                                                 sizeof(serv_addr));
2458                 serv_addr.sin_port = htons(port);
2459
2460                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
2461                                                              sizeof(serv_addr));
2462                 if (n < 0) {
2463                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
2464                                                                 port, n, errno);
2465                         return NULL;
2466                 }
2467
2468                 wsi = malloc(sizeof(struct libwebsocket));
2469                 memset(wsi, 0, sizeof (struct libwebsocket));
2470                 wsi->sock = sockfd;
2471                 wsi->count_active_extensions = 0;
2472                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
2473                 insert_wsi(context, wsi);
2474
2475                 listen(sockfd, 5);
2476                 fprintf(stderr, " Listening on port %d\n", port);
2477
2478                 /* list in the internal poll array */
2479
2480                 context->fds[context->fds_count].fd = sockfd;
2481                 context->fds[context->fds_count++].events = POLLIN;
2482
2483                 /* external POLL support via protocol 0 */
2484                 context->protocols[0].callback(context, wsi,
2485                         LWS_CALLBACK_ADD_POLL_FD,
2486                         (void *)(long)sockfd, NULL, POLLIN);
2487
2488         }
2489
2490         /* drop any root privs for this process */
2491 #ifdef WIN32
2492 #else
2493         if (gid != -1)
2494                 if (setgid(gid))
2495                         fprintf(stderr, "setgid: %s\n", strerror(errno));
2496         if (uid != -1)
2497                 if (setuid(uid))
2498                         fprintf(stderr, "setuid: %s\n", strerror(errno));
2499 #endif
2500
2501         /* set up our internal broadcast trigger sockets per-protocol */
2502
2503         for (context->count_protocols = 0;
2504                         protocols[context->count_protocols].callback;
2505                                                    context->count_protocols++) {
2506                 protocols[context->count_protocols].owning_server = context;
2507                 protocols[context->count_protocols].protocol_index =
2508                                                        context->count_protocols;
2509
2510                 fd = socket(AF_INET, SOCK_STREAM, 0);
2511                 if (fd < 0) {
2512                         fprintf(stderr, "ERROR opening socket");
2513                         return NULL;
2514                 }
2515
2516                 /* allow us to restart even if old sockets in TIME_WAIT */
2517                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
2518
2519                 bzero((char *) &serv_addr, sizeof(serv_addr));
2520                 serv_addr.sin_family = AF_INET;
2521                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
2522                 serv_addr.sin_port = 0; /* pick the port for us */
2523
2524                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
2525                 if (n < 0) {
2526                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
2527                                                                 port, n, errno);
2528                         return NULL;
2529                 }
2530
2531                 slen = sizeof cli_addr;
2532                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
2533                 if (n < 0) {
2534                         fprintf(stderr, "getsockname failed\n");
2535                         return NULL;
2536                 }
2537                 protocols[context->count_protocols].broadcast_socket_port =
2538                                                        ntohs(cli_addr.sin_port);
2539                 listen(fd, 5);
2540
2541                 debug("  Protocol %s broadcast socket %d\n",
2542                                 protocols[context->count_protocols].name,
2543                                                       ntohs(cli_addr.sin_port));
2544
2545                 /* dummy wsi per broadcast proxy socket */
2546
2547                 wsi = malloc(sizeof(struct libwebsocket));
2548                 memset(wsi, 0, sizeof (struct libwebsocket));
2549                 wsi->sock = fd;
2550                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
2551                 wsi->count_active_extensions = 0;
2552                 /* note which protocol we are proxying */
2553                 wsi->protocol_index_for_broadcast_proxy =
2554                                                        context->count_protocols;
2555                 insert_wsi(context, wsi);
2556
2557                 /* list in internal poll array */
2558
2559                 context->fds[context->fds_count].fd = fd;
2560                 context->fds[context->fds_count].events = POLLIN;
2561                 context->fds[context->fds_count].revents = 0;
2562                 context->fds_count++;
2563
2564                 /* external POLL support via protocol 0 */
2565                 context->protocols[0].callback(context, wsi,
2566                         LWS_CALLBACK_ADD_POLL_FD,
2567                         (void *)(long)fd, NULL, POLLIN);
2568         }
2569
2570         return context;
2571 }
2572
2573
2574 #ifndef LWS_NO_FORK
2575
2576 /**
2577  * libwebsockets_fork_service_loop() - Optional helper function forks off
2578  *                                a process for the websocket server loop.
2579  *                              You don't have to use this but if not, you
2580  *                              have to make sure you are calling
2581  *                              libwebsocket_service periodically to service
2582  *                              the websocket traffic
2583  * @context:    server context returned by creation function
2584  */
2585
2586 int
2587 libwebsockets_fork_service_loop(struct libwebsocket_context *context)
2588 {
2589         int fd;
2590         struct sockaddr_in cli_addr;
2591         int n;
2592         int p;
2593
2594         n = fork();
2595         if (n < 0)
2596                 return n;
2597
2598         if (!n) {
2599
2600                 /* main process context */
2601
2602                 /*
2603                  * set up the proxy sockets to allow broadcast from
2604                  * service process context
2605                  */
2606
2607                 for (p = 0; p < context->count_protocols; p++) {
2608                         fd = socket(AF_INET, SOCK_STREAM, 0);
2609                         if (fd < 0) {
2610                                 fprintf(stderr, "Unable to create socket\n");
2611                                 return -1;
2612                         }
2613                         cli_addr.sin_family = AF_INET;
2614                         cli_addr.sin_port = htons(
2615                              context->protocols[p].broadcast_socket_port);
2616                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
2617                         n = connect(fd, (struct sockaddr *)&cli_addr,
2618                                                                sizeof cli_addr);
2619                         if (n < 0) {
2620                                 fprintf(stderr, "Unable to connect to "
2621                                                 "broadcast socket %d, %s\n",
2622                                                 n, strerror(errno));
2623                                 return -1;
2624                         }
2625
2626                         context->protocols[p].broadcast_socket_user_fd = fd;
2627                 }
2628
2629                 return 0;
2630         }
2631
2632         /* we want a SIGHUP when our parent goes down */
2633         prctl(PR_SET_PDEATHSIG, SIGHUP);
2634
2635         /* in this forked process, sit and service websocket connections */
2636
2637         while (1)
2638                 if (libwebsocket_service(context, 1000))
2639                         return -1;
2640
2641         return 0;
2642 }
2643
2644 #endif
2645
2646 /**
2647  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
2648  *                                connection.
2649  * @wsi:        pointer to struct websocket you want to know the protocol of
2650  *
2651  *
2652  *      This is useful to get the protocol to broadcast back to from inside
2653  * the callback.
2654  */
2655
2656 const struct libwebsocket_protocols *
2657 libwebsockets_get_protocol(struct libwebsocket *wsi)
2658 {
2659         return wsi->protocol;
2660 }
2661
2662 /**
2663  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
2664  *                                connections of the given protocol.
2665  * @protocol:   pointer to the protocol you will broadcast to all members of
2666  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
2667  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
2668  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
2669  *              case you are calling this function from callback context.
2670  * @len:        length of payload data in buf, starting from buf.
2671  *
2672  *      This function allows bulk sending of a packet to every connection using
2673  * the given protocol.  It does not send the data directly; instead it calls
2674  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
2675  * wants to actually send the data for that connection, the callback itself
2676  * should call libwebsocket_write().
2677  *
2678  * libwebsockets_broadcast() can be called from another fork context without
2679  * having to take any care about data visibility between the processes, it'll
2680  * "just work".
2681  */
2682
2683
2684 int
2685 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
2686                                                  unsigned char *buf, size_t len)
2687 {
2688         struct libwebsocket_context *context = protocol->owning_server;
2689         int n;
2690         int m;
2691         struct libwebsocket * wsi;
2692
2693         if (!protocol->broadcast_socket_user_fd) {
2694                 /*
2695                  * We are either running unforked / flat, or we are being
2696                  * called from poll thread context
2697                  * eg, from a callback.  In that case don't use sockets for
2698                  * broadcast IPC (since we can't open a socket connection to
2699                  * a socket listening on our own thread) but directly do the
2700                  * send action.
2701                  *
2702                  * Locking is not needed because we are by definition being
2703                  * called in the poll thread context and are serialized.
2704                  */
2705
2706                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
2707
2708                         for (m = 0; m < context->fd_hashtable[n].length; m++) {
2709
2710                                 wsi = context->fd_hashtable[n].wsi[m];
2711
2712                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
2713                                         continue;
2714
2715                                 /*
2716                                  * never broadcast to
2717                                  * non-established connections
2718                                  */
2719                                 if (wsi->state != WSI_STATE_ESTABLISHED)
2720                                         continue;
2721
2722                                 /* only broadcast to guys using
2723                                  * requested protocol
2724                                  */
2725                                 if (wsi->protocol != protocol)
2726                                         continue;
2727
2728                                 wsi->protocol->callback(context, wsi,
2729                                          LWS_CALLBACK_BROADCAST,
2730                                          wsi->user_space,
2731                                          buf, len);
2732                         }
2733                 }
2734
2735                 return 0;
2736         }
2737
2738         /*
2739          * We're being called from a different process context than the server
2740          * loop.  Instead of broadcasting directly, we send our
2741          * payload on a socket to do the IPC; the server process will serialize
2742          * the broadcast action in its main poll() loop.
2743          *
2744          * There's one broadcast socket listening for each protocol supported
2745          * set up when the websocket server initializes
2746          */
2747
2748         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
2749
2750         return n;
2751 }
2752
2753 int
2754 libwebsocket_is_final_fragment(struct libwebsocket *wsi)
2755 {
2756         return wsi->final;
2757 }