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 #include <ifaddrs.h>
  24
  25 /*
  26  * In-place str to lower case
  27  */
  28
  29 static void
  30 strtolower(char *s)
  31 {
  32         while (*s) {
  33                 *s = tolower(*s);
  34                 s++;
  35         }
  36 }
  37
  38 /* file descriptor hash management */
  39
  40 struct libwebsocket *
  41 wsi_from_fd(struct libwebsocket_context *this, int fd)
  42 {
  43         int h = LWS_FD_HASH(fd);
  44         int n = 0;
  45
  46         for (n = 0; n < this->fd_hashtable[h].length; n++)
  47                 if (this->fd_hashtable[h].wsi[n]->sock == fd)
  48                         return this->fd_hashtable[h].wsi[n];
  49
  50         return NULL;
  51 }
  52
  53 int
  54 insert_wsi(struct libwebsocket_context *this, struct libwebsocket *wsi)
  55 {
  56         int h = LWS_FD_HASH(wsi->sock);
  57
  58         if (this->fd_hashtable[h].length == MAX_CLIENTS - 1) {
  59                 fprintf(stderr, "hash table overflow\n");
  60                 return 1;
  61         }
  62
  63         this->fd_hashtable[h].wsi[this->fd_hashtable[h].length++] = wsi;
  64
  65         return 0;
  66 }
  67
  68 int
  69 delete_from_fd(struct libwebsocket_context *this, int fd)
  70 {
  71         int h = LWS_FD_HASH(fd);
  72         int n = 0;
  73
  74         for (n = 0; n < this->fd_hashtable[h].length; n++)
  75                 if (this->fd_hashtable[h].wsi[n]->sock == fd) {
  76                         while (n < this->fd_hashtable[h].length) {
  77                                 this->fd_hashtable[h].wsi[n] =
  78                                                this->fd_hashtable[h].wsi[n + 1];
  79                                 n++;
  80                         }
  81                         this->fd_hashtable[h].length--;
  82
  83                         return 0;
  84                 }
  85
  86         fprintf(stderr, "Failed to find fd %d requested for "
  87                                                    "delete in hashtable\n", fd);
  88         return 1;
  89 }
  90
  91 #ifdef LWS_OPENSSL_SUPPORT
  92 static void
  93 libwebsockets_decode_ssl_error(void)
  94 {
  95         char buf[256];
  96         u_long err;
  97
  98         while ((err = ERR_get_error()) != 0) {
  99                 ERR_error_string_n(err, buf, sizeof(buf));
 100                 fprintf(stderr, "*** %s\n", buf);
 101         }
 102 }
 103 #endif
 104
 105
 106 static int
 107 interface_to_sa(const char* ifname, struct sockaddr_in *addr, size_t addrlen)
 108 {
 109         int rc = -1;
 110         struct ifaddrs *ifr;
 111         struct ifaddrs *ifc;
 112         struct sockaddr_in *sin;
 113
 114         getifaddrs(&ifr);
 115         for (ifc = ifr; ifc != NULL; ifc = ifc->ifa_next) {
 116                 if (strcmp(ifc->ifa_name, ifname))
 117                         continue;
 118                 if (ifc->ifa_addr == NULL)
 119                         continue;
 120                 sin = (struct sockaddr_in *)ifc->ifa_addr;
 121                 if (sin->sin_family != AF_INET)
 122                         continue;
 123                 memcpy(addr, sin, addrlen);
 124                 rc = 0;
 125         }
 126
 127         freeifaddrs(ifr);
 128
 129         return rc;
 130 }
 131
 132 void
 133 libwebsocket_close_and_free_session(struct libwebsocket_context *this,
 134                          struct libwebsocket *wsi, enum lws_close_status reason)
 135 {
 136         int n;
 137         int old_state;
 138         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
 139                                                   LWS_SEND_BUFFER_POST_PADDING];
 140
 141         if (!wsi)
 142                 return;
 143
 144         old_state = wsi->state;
 145
 146         if (old_state == WSI_STATE_DEAD_SOCKET)
 147                 return;
 148
 149         /* remove this fd from wsi mapping hashtable */
 150
 151         delete_from_fd(this, wsi->sock);
 152
 153         /* delete it from the internal poll list if still present */
 154
 155         for (n = 0; n < this->fds_count; n++) {
 156                 if (this->fds[n].fd != wsi->sock)
 157                         continue;
 158                 while (n < this->fds_count - 1) {
 159                         this->fds[n] = this->fds[n + 1];
 160                         n++;
 161                 }
 162                 this->fds_count--;
 163                 /* we only have to deal with one */
 164                 n = this->fds_count;
 165         }
 166
 167         /* remove also from external POLL support via protocol 0 */
 168
 169         this->protocols[0].callback(this, wsi,
 170                     LWS_CALLBACK_DEL_POLL_FD, (void *)(long)wsi->sock, NULL, 0);
 171
 172         wsi->close_reason = reason;
 173
 174         /*
 175          * signal we are closing, libsocket_write will
 176          * add any necessary version-specific stuff.  If the write fails,
 177          * no worries we are closing anyway.  If we didn't initiate this
 178          * close, then our state has been changed to
 179          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this
 180          */
 181
 182         if (old_state == WSI_STATE_ESTABLISHED)
 183                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
 184                                                                LWS_WRITE_CLOSE);
 185
 186         wsi->state = WSI_STATE_DEAD_SOCKET;
 187
 188         /* tell the user it's all over for this guy */
 189
 190         if (wsi->protocol->callback && old_state == WSI_STATE_ESTABLISHED)
 191                 wsi->protocol->callback(this, wsi, LWS_CALLBACK_CLOSED,
 192                                                       wsi->user_space, NULL, 0);
 193
 194         /* free up his allocations */
 195
 196         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 197                 if (wsi->utf8_token[n].token)
 198                         free(wsi->utf8_token[n].token);
 199
 200 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 201
 202 #ifdef LWS_OPENSSL_SUPPORT
 203         if (wsi->ssl) {
 204                 n = SSL_get_fd(wsi->ssl);
 205                 SSL_shutdown(wsi->ssl);
 206                 close(n);
 207                 SSL_free(wsi->ssl);
 208         } else {
 209 #endif
 210                 shutdown(wsi->sock, SHUT_RDWR);
 211                 close(wsi->sock);
 212 #ifdef LWS_OPENSSL_SUPPORT
 213         }
 214 #endif
 215         if (wsi->user_space)
 216                 free(wsi->user_space);
 217
 218         free(wsi);
 219 }
 220
 221 /**
 222  * libwebsockets_hangup_on_client() - Server calls to terminate client
 223  *                                      connection
 224  * @this:       libwebsockets context
 225  * @fd:         Connection socket descriptor
 226  */
 227
 228 void
 229 libwebsockets_hangup_on_client(struct libwebsocket_context *this, int fd)
 230 {
 231         struct libwebsocket *wsi = wsi_from_fd(this, fd);
 232         int n;
 233
 234         if (wsi == NULL)
 235                 return;
 236
 237         delete_from_fd(this, fd);
 238
 239         for (n = 0; n < this->fds_count - 1; n++)
 240                 if (this->fds[n].fd == fd) {
 241                         while (n < this->fds_count - 1) {
 242                                 this->fds[n] = this->fds[n + 1];
 243                                 n++;
 244                         }
 245                         n = this->fds_count;
 246                         this->fds_count--;
 247                 }
 248
 249         libwebsocket_close_and_free_session(this, wsi, 0);
 250 }
 251
 252
 253 /**
 254  * libwebsockets_get_peer_addresses() - Get client address information
 255  * @fd:         Connection socket descriptor
 256  * @name:       Buffer to take client address name
 257  * @name_len:   Length of client address name buffer
 258  * @rip:        Buffer to take client address IP qotted quad
 259  * @rip_len:    Length of client address IP buffer
 260  *
 261  *      This function fills in @name and @rip with the name and IP of
 262  *      the client connected with socket descriptor @fd.  Names may be
 263  *      truncated if there is not enough room.  If either cannot be
 264  *      determined, they will be returned as valid zero-length strings.
 265  */
 266
 267 void
 268 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 269                                         char *rip, int rip_len)
 270 {
 271         unsigned int len;
 272         struct sockaddr_in sin;
 273         struct hostent *host;
 274         struct hostent *host1;
 275         char ip[128];
 276         char *p;
 277         int n;
 278
 279         rip[0] = '\0';
 280         name[0] = '\0';
 281
 282         len = sizeof sin;
 283         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 284                 perror("getpeername");
 285                 return;
 286         }
 287
 288         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 289                                                                        AF_INET);
 290         if (host == NULL) {
 291                 perror("gethostbyaddr");
 292                 return;
 293         }
 294
 295         strncpy(name, host->h_name, name_len);
 296         name[name_len - 1] = '\0';
 297
 298         host1 = gethostbyname(host->h_name);
 299         if (host1 == NULL)
 300                 return;
 301         p = (char *)host1;
 302         n = 0;
 303         while (p != NULL) {
 304                 p = host1->h_addr_list[n++];
 305                 if (p == NULL)
 306                         continue;
 307                 if (host1->h_addrtype != AF_INET)
 308                         continue;
 309
 310                 sprintf(ip, "%d.%d.%d.%d",
 311                                 p[0], p[1], p[2], p[3]);
 312                 p = NULL;
 313                 strncpy(rip, ip, rip_len);
 314                 rip[rip_len - 1] = '\0';
 315         }
 316 }
 317
 318 /**
 319  * libwebsocket_service_fd() - Service polled socket with something waiting
 320  * @this:       Websocket context
 321  * @pollfd:     The pollfd entry describing the socket fd and which events
 322  *              happened.
 323  *
 324  *      This function closes any active connections and then frees the
 325  *      context.  After calling this, any further use of the context is
 326  *      undefined.
 327  */
 328
 329 int
 330 libwebsocket_service_fd(struct libwebsocket_context *this,
 331                                                           struct pollfd *pollfd)
 332 {
 333         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
 334                                                   LWS_SEND_BUFFER_POST_PADDING];
 335         struct libwebsocket *wsi;
 336         struct libwebsocket *new_wsi;
 337         int n;
 338         int m;
 339         size_t len;
 340         int accept_fd;
 341         unsigned int clilen;
 342         struct sockaddr_in cli_addr;
 343         struct timeval tv;
 344         static const char magic_websocket_guid[] =
 345                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 346         static const char magic_websocket_04_masking_guid[] =
 347                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 348         char hash[20];
 349         char pkt[1024];
 350         char *p = &pkt[0];
 351         const char *pc;
 352         int okay = 0;
 353 #ifdef LWS_OPENSSL_SUPPORT
 354         char ssl_err_buf[512];
 355 #endif
 356         /*
 357          * you can call us with pollfd = NULL to just allow the once-per-second
 358          * global timeout checks; if less than a second since the last check
 359          * it returns immediately then.
 360          */
 361
 362         gettimeofday(&tv, NULL);
 363
 364         if (this->last_timeout_check_s != tv.tv_sec) {
 365                 this->last_timeout_check_s = tv.tv_sec;
 366
 367                 /* global timeout check once per second */
 368
 369                 for (n = 0; n < this->fds_count; n++) {
 370                         wsi = wsi_from_fd(this, this->fds[n].fd);
 371                         if (!wsi->pending_timeout)
 372                                 continue;
 373
 374                         /*
 375                          * if we went beyond the allowed time, kill the
 376                          * connection
 377                          */
 378
 379                         if (tv.tv_sec > wsi->pending_timeout_limit)
 380                                 libwebsocket_close_and_free_session(this, wsi,
 381                                                      LWS_CLOSE_STATUS_NOSTATUS);
 382                 }
 383         }
 384
 385         /* just here for timeout management? */
 386
 387         if (pollfd == NULL)
 388                 return 0;
 389
 390         /* no, here to service a socket descriptor */
 391
 392         wsi = wsi_from_fd(this, pollfd->fd);
 393
 394         if (wsi == NULL)
 395                 return 1;
 396
 397         switch (wsi->mode) {
 398         case LWS_CONNMODE_SERVER_LISTENER:
 399
 400                 /* pollin means a client has connected to us then */
 401
 402                 if (!pollfd->revents & POLLIN)
 403                         break;
 404
 405                 /* listen socket got an unencrypted connection... */
 406
 407                 clilen = sizeof(cli_addr);
 408                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 409                                                                        &clilen);
 410                 if (accept_fd < 0) {
 411                         fprintf(stderr, "ERROR on accept");
 412                         break;
 413                 }
 414
 415                 if (this->fds_count >= MAX_CLIENTS) {
 416                         fprintf(stderr, "too busy to accept new client\n");
 417                         close(accept_fd);
 418                         break;
 419                 }
 420
 421                 /*
 422                  * look at who we connected to and give user code a chance
 423                  * to reject based on client IP.  There's no protocol selected
 424                  * yet so we issue this to protocols[0]
 425                  */
 426
 427                 if ((this->protocols[0].callback)(this, wsi,
 428                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 429                                              (void*)(long)accept_fd, NULL, 0)) {
 430                         fprintf(stderr, "Callback denied network connection\n");
 431                         close(accept_fd);
 432                         break;
 433                 }
 434
 435                 /* accepting connection to main listener */
 436
 437                 new_wsi = malloc(sizeof(struct libwebsocket));
 438                 if (new_wsi == NULL) {
 439                         fprintf(stderr, "Out of memory for new connection\n");
 440                         break;
 441                 }
 442
 443                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 444                 new_wsi->sock = accept_fd;
 445                 new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
 446
 447 #ifdef LWS_OPENSSL_SUPPORT
 448                 new_wsi->ssl = NULL;
 449
 450                 if (this->use_ssl) {
 451
 452                         new_wsi->ssl = SSL_new(this->ssl_ctx);
 453                         if (new_wsi->ssl == NULL) {
 454                                 fprintf(stderr, "SSL_new failed: %s\n",
 455                                     ERR_error_string(SSL_get_error(
 456                                     new_wsi->ssl, 0), NULL));
 457                                     libwebsockets_decode_ssl_error();
 458                                 free(new_wsi);
 459                                 break;
 460                         }
 461
 462                         SSL_set_fd(new_wsi->ssl, accept_fd);
 463
 464                         n = SSL_accept(new_wsi->ssl);
 465                         if (n != 1) {
 466                                 /*
 467                                  * browsers seem to probe with various
 468                                  * ssl params which fail then retry
 469                                  * and succeed
 470                                  */
 471                                 debug("SSL_accept failed skt %u: %s\n",
 472                                       pollfd->fd,
 473                                       ERR_error_string(SSL_get_error(
 474                                       new_wsi->ssl, n), NULL));
 475                                 SSL_free(
 476                                        new_wsi->ssl);
 477                                 free(new_wsi);
 478                                 break;
 479                         }
 480
 481                         debug("accepted new SSL conn  "
 482                               "port %u on fd=%d SSL ver %s\n",
 483                                 ntohs(cli_addr.sin_port), accept_fd,
 484                                   SSL_get_version(new_wsi->ssl));
 485
 486                 } else
 487 #endif
 488                         debug("accepted new conn  port %u on fd=%d\n",
 489                                           ntohs(cli_addr.sin_port), accept_fd);
 490
 491                 /* intialize the instance struct */
 492
 493                 new_wsi->state = WSI_STATE_HTTP;
 494                 new_wsi->name_buffer_pos = 0;
 495                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 496
 497                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 498                         new_wsi->utf8_token[n].token = NULL;
 499                         new_wsi->utf8_token[n].token_len = 0;
 500                 }
 501
 502                 /*
 503                  * these can only be set once the protocol is known
 504                  * we set an unestablished connection's protocol pointer
 505                  * to the start of the supported list, so it can look
 506                  * for matching ones during the handshake
 507                  */
 508                 new_wsi->protocol = this->protocols;
 509                 new_wsi->user_space = NULL;
 510
 511                 /*
 512                  * Default protocol is 76 / 00
 513                  * After 76, there's a header specified to inform which
 514                  * draft the client wants, when that's seen we modify
 515                  * the individual connection's spec revision accordingly
 516                  */
 517                 new_wsi->ietf_spec_revision = 0;
 518
 519                 insert_wsi(this, new_wsi);
 520
 521                 /*
 522                  * make sure NO events are seen yet on this new socket
 523                  * (otherwise we inherit old fds[client].revents from
 524                  * previous socket there and die mysteriously! )
 525                  */
 526                 this->fds[this->fds_count].revents = 0;
 527
 528                 this->fds[this->fds_count].events = POLLIN;
 529                 this->fds[this->fds_count++].fd = accept_fd;
 530
 531                 /* external POLL support via protocol 0 */
 532                 this->protocols[0].callback(this, new_wsi,
 533                         LWS_CALLBACK_ADD_POLL_FD,
 534                         (void *)(long)accept_fd, NULL, POLLIN);
 535
 536                 break;
 537
 538         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 539
 540                 /* as we are listening, POLLIN means accept() is needed */
 541
 542                 if (!pollfd->revents & POLLIN)
 543                         break;
 544
 545                 /* listen socket got an unencrypted connection... */
 546
 547                 clilen = sizeof(cli_addr);
 548                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 549                                                                        &clilen);
 550                 if (accept_fd < 0) {
 551                         fprintf(stderr, "ERROR on accept");
 552                         break;
 553                 }
 554
 555                 if (this->fds_count >= MAX_CLIENTS) {
 556                         fprintf(stderr, "too busy to accept new broadcast "
 557                                                               "proxy client\n");
 558                         close(accept_fd);
 559                         break;
 560                 }
 561
 562                 /* create a dummy wsi for the connection and add it */
 563
 564                 new_wsi = malloc(sizeof(struct libwebsocket));
 565                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 566                 new_wsi->sock = accept_fd;
 567                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 568                 new_wsi->state = WSI_STATE_ESTABLISHED;
 569                 /* note which protocol we are proxying */
 570                 new_wsi->protocol_index_for_broadcast_proxy =
 571                                         wsi->protocol_index_for_broadcast_proxy;
 572                 insert_wsi(this, new_wsi);
 573
 574                 /* add connected socket to internal poll array */
 575
 576                 this->fds[this->fds_count].revents = 0;
 577                 this->fds[this->fds_count].events = POLLIN;
 578                 this->fds[this->fds_count++].fd = accept_fd;
 579
 580                 /* external POLL support via protocol 0 */
 581                 this->protocols[0].callback(this, new_wsi,
 582                         LWS_CALLBACK_ADD_POLL_FD,
 583                         (void *)(long)accept_fd, NULL, POLLIN);
 584
 585                 break;
 586
 587         case LWS_CONNMODE_BROADCAST_PROXY:
 588
 589                 /* handle session socket closed */
 590
 591                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 592
 593                         debug("Session Socket %p (fd=%d) dead\n",
 594                                 (void *)wsi, pollfd->fd);
 595
 596                         libwebsocket_close_and_free_session(this, wsi,
 597                                                        LWS_CLOSE_STATUS_NORMAL);
 598                         return 1;
 599                 }
 600
 601                 /* the guy requested a callback when it was OK to write */
 602
 603                 if (pollfd->revents & POLLOUT) {
 604
 605                         /* one shot */
 606
 607                         pollfd->events &= ~POLLOUT;
 608
 609                         /* external POLL support via protocol 0 */
 610                         this->protocols[0].callback(this, wsi,
 611                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 612                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 613
 614                         wsi->protocol->callback(this, wsi,
 615                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 616                                 wsi->user_space,
 617                                 NULL, 0);
 618                 }
 619
 620                 /* any incoming data ready? */
 621
 622                 if (!(pollfd->revents & POLLIN))
 623                         break;
 624
 625                 /* get the issued broadcast payload from the socket */
 626
 627                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 628                                                          MAX_BROADCAST_PAYLOAD);
 629                 if (len < 0) {
 630                         fprintf(stderr, "Error reading broadcast payload\n");
 631                         break;
 632                 }
 633
 634                 /* broadcast it to all guys with this protocol index */
 635
 636                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 637
 638                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
 639
 640                                 new_wsi = this->fd_hashtable[n].wsi[m];
 641
 642                                 /* only to clients we are serving to */
 643
 644                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 645                                         continue;
 646
 647                                 /*
 648                                  * never broadcast to non-established
 649                                  * connection
 650                                  */
 651
 652                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 653                                         continue;
 654
 655                                 /*
 656                                  * only broadcast to connections using
 657                                  * the requested protocol
 658                                  */
 659
 660                                 if (new_wsi->protocol->protocol_index !=
 661                                         wsi->protocol_index_for_broadcast_proxy)
 662                                         continue;
 663
 664                                 /* broadcast it to this connection */
 665
 666                                 new_wsi->protocol->callback(this, new_wsi,
 667                                         LWS_CALLBACK_BROADCAST,
 668                                         new_wsi->user_space,
 669                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 670                         }
 671                 }
 672                 break;
 673
 674         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
 675
 676                 /* handle proxy hung up on us */
 677
 678                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 679
 680                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
 681                                 (void *)wsi, pollfd->fd);
 682
 683                         libwebsocket_close_and_free_session(this, wsi,
 684                                                      LWS_CLOSE_STATUS_NOSTATUS);
 685                         return 1;
 686                 }
 687
 688                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
 689                 if (n < 0) {
 690                         libwebsocket_close_and_free_session(this, wsi,
 691                                                      LWS_CLOSE_STATUS_NOSTATUS);
 692                         fprintf(stderr, "ERROR reading from proxy socket\n");
 693                         return 1;
 694                 }
 695
 696                 pkt[13] = '\0';
 697                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
 698                         libwebsocket_close_and_free_session(this, wsi,
 699                                                      LWS_CLOSE_STATUS_NOSTATUS);
 700                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
 701                         return 1;
 702                 }
 703
 704                 /* clear his proxy connection timeout */
 705
 706                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 707
 708                 /* fallthru */
 709
 710         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
 711
 712         #ifdef LWS_OPENSSL_SUPPORT
 713                 if (wsi->use_ssl) {
 714
 715                         wsi->ssl = SSL_new(this->ssl_client_ctx);
 716                         wsi->client_bio = BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 717                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 718
 719                         SSL_set_ex_data(wsi->ssl,
 720                               this->openssl_websocket_private_data_index, this);
 721
 722                         if (SSL_connect(wsi->ssl) <= 0) {
 723                                 fprintf(stderr, "SSL connect error %s\n",
 724                                         ERR_error_string(ERR_get_error(),
 725                                                                   ssl_err_buf));
 726                                 libwebsocket_close_and_free_session(this, wsi,
 727                                                      LWS_CLOSE_STATUS_NOSTATUS);
 728                                 return 1;
 729                         }
 730
 731                         n = SSL_get_verify_result(wsi->ssl);
 732                         if (n != X509_V_OK) && (
 733                                 n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 734                                                            wsi->use_ssl != 2)) {
 735
 736                                 fprintf(stderr, "server's cert didn't "
 737                                                            "look good %d\n", n);
 738                                 libwebsocket_close_and_free_session(this, wsi,
 739                                                      LWS_CLOSE_STATUS_NOSTATUS);
 740                                 return 1;
 741                         }
 742                 } else {
 743                         wsi->ssl = NULL;
 744         #endif
 745
 746
 747         #ifdef LWS_OPENSSL_SUPPORT
 748                 }
 749         #endif
 750
 751                 /*
 752                  * create the random key
 753                  */
 754
 755                 n = read(this->fd_random, hash, 16);
 756                 if (n != 16) {
 757                         fprintf(stderr, "Unable to read from random dev %s\n",
 758                                                         SYSTEM_RANDOM_FILEPATH);
 759                         free(wsi->c_path);
 760                         free(wsi->c_host);
 761                         if (wsi->c_origin)
 762                                 free(wsi->c_origin);
 763                         if (wsi->c_protocol)
 764                                 free(wsi->c_protocol);
 765                         libwebsocket_close_and_free_session(this, wsi,
 766                                                      LWS_CLOSE_STATUS_NOSTATUS);
 767                         return 1;
 768                 }
 769
 770                 lws_b64_encode_string(hash, 16, wsi->key_b64,
 771                                                            sizeof wsi->key_b64);
 772
 773                 /*
 774                  * 04 example client handshake
 775                  *
 776                  * GET /chat HTTP/1.1
 777                  * Host: server.example.com
 778                  * Upgrade: websocket
 779                  * Connection: Upgrade
 780                  * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 781                  * Sec-WebSocket-Origin: http://example.com
 782                  * Sec-WebSocket-Protocol: chat, superchat
 783                  * Sec-WebSocket-Version: 4
 784                  */
 785
 786                 p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 787                 p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 788                 p += sprintf(p, "Upgrade: websocket\x0d\x0a");
 789                 p += sprintf(p, "Connection: Upgrade\x0d\x0a"
 790                                         "Sec-WebSocket-Key: ");
 791                 strcpy(p, wsi->key_b64);
 792                 p += strlen(wsi->key_b64);
 793                 p += sprintf(p, "\x0d\x0a");
 794                 if (wsi->c_origin)
 795                         p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
 796                                                                  wsi->c_origin);
 797                 if (wsi->c_protocol)
 798                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 799                                                                wsi->c_protocol);
 800                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a",
 801                                                        wsi->ietf_spec_revision);
 802
 803                 /* done with these now */
 804
 805                 free(wsi->c_path);
 806                 free(wsi->c_host);
 807                 if (wsi->c_origin)
 808                         free(wsi->c_origin);
 809
 810                 /* prepare the expected server accept response */
 811
 812                 strcpy((char *)buf, wsi->key_b64);
 813                 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 814
 815                 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 816
 817                 lws_b64_encode_string(hash, 20,
 818                                 wsi->initial_handshake_hash_base64,
 819                                      sizeof wsi->initial_handshake_hash_base64);
 820
 821                 /* send our request to the server */
 822
 823         #ifdef LWS_OPENSSL_SUPPORT
 824                 if (wsi->use_ssl)
 825                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 826                 else
 827         #endif
 828                         n = send(wsi->sock, pkt, p - pkt, 0);
 829
 830                 if (n < 0) {
 831                         fprintf(stderr, "ERROR writing to client socket\n");
 832                         libwebsocket_close_and_free_session(this, wsi,
 833                                                      LWS_CLOSE_STATUS_NOSTATUS);
 834                         return 1;
 835                 }
 836
 837                 wsi->parser_state = WSI_TOKEN_NAME_PART;
 838                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 839                 libwebsocket_set_timeout(wsi,
 840                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, 5);
 841
 842                 break;
 843
 844         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 845
 846                 /* handle server hung up on us */
 847
 848                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 849
 850                         fprintf(stderr, "Server connection %p (fd=%d) dead\n",
 851                                 (void *)wsi, pollfd->fd);
 852
 853                         goto bail3;
 854                 }
 855
 856
 857                 /* interpret the server response */
 858
 859                 /*
 860                  *  HTTP/1.1 101 Switching Protocols
 861                  *  Upgrade: websocket
 862                  *  Connection: Upgrade
 863                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 864                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 865                  *  Sec-WebSocket-Protocol: chat
 866                  */
 867
 868         #ifdef LWS_OPENSSL_SUPPORT
 869                 if (wsi->use_ssl)
 870                         len = SSL_read(wsi->ssl, pkt, sizeof pkt);
 871                 else
 872         #endif
 873                         len = recv(wsi->sock, pkt, sizeof pkt, 0);
 874
 875                 if (len < 0) {
 876                         fprintf(stderr,
 877                                   "libwebsocket_client_handshake read error\n");
 878                         goto bail3;
 879                 }
 880
 881                 p = pkt;
 882                 for (n = 0; n < len; n++)
 883                         libwebsocket_parse(wsi, *p++);
 884
 885                 if (wsi->parser_state != WSI_PARSING_COMPLETE) {
 886                         fprintf(stderr, "libwebsocket_client_handshake "
 887                                         "server response ailed parsing\n");
 888                         goto bail3;
 889                 }
 890
 891                 /*
 892                  * well, what the server sent looked reasonable for syntax.
 893                  * Now let's confirm it sent all the necessary headers
 894                  */
 895
 896                  if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 897                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 898                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 899                         !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 900                         !wsi->utf8_token[WSI_TOKEN_NONCE].token_len ||
 901                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
 902                                                      wsi->c_protocol != NULL)) {
 903                         fprintf(stderr, "libwebsocket_client_handshake "
 904                                                 "missing required header(s)\n");
 905                         pkt[len] = '\0';
 906                         fprintf(stderr, "%s", pkt);
 907                         goto bail3;
 908                 }
 909
 910                 /*
 911                  * Everything seems to be there, now take a closer look at what
 912                  * is in each header
 913                  */
 914
 915                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 916                 if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
 917                                                    "101 switching protocols")) {
 918                         fprintf(stderr, "libwebsocket_client_handshake "
 919                                         "server sent bad HTTP response '%s'\n",
 920                                          wsi->utf8_token[WSI_TOKEN_HTTP].token);
 921                         goto bail3;
 922                 }
 923
 924                 strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 925                 if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 926                                                                  "websocket")) {
 927                         fprintf(stderr, "libwebsocket_client_handshake server "
 928                                         "sent bad Upgrade header '%s'\n",
 929                                       wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 930                         goto bail3;
 931                 }
 932
 933                 strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 934                 if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 935                                                                    "upgrade")) {
 936                         fprintf(stderr, "libwebsocket_client_handshake server "
 937                                         "sent bad Connection hdr '%s'\n",
 938                                    wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 939                         goto bail3;
 940                 }
 941
 942
 943                 pc = wsi->c_protocol;
 944
 945                 /*
 946                  * confirm the protocol the server wants to talk was in the list
 947                  * of protocols we offered
 948                  */
 949
 950                 if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 951
 952                         /*
 953                          * no protocol name to work from,
 954                          * default to first protocol
 955                          */
 956                         wsi->protocol = &this->protocols[0];
 957
 958                         free(wsi->c_protocol);
 959
 960                         goto check_accept;
 961                 }
 962
 963                 while (*pc && !okay) {
 964                         if ((!strncmp(pc,
 965                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 966                            wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 967                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 968                    pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 969                                 okay = 1;
 970                                 continue;
 971                         }
 972                         while (*pc && *pc != ',')
 973                                 pc++;
 974                         while (*pc && *pc != ' ')
 975                                 pc++;
 976                 }
 977
 978                 /* done with him now */
 979
 980                 if (wsi->c_protocol)
 981                         free(wsi->c_protocol);
 982
 983
 984                 if (!okay) {
 985                         fprintf(stderr, "libwebsocket_client_handshake server "
 986                                                 "sent bad protocol '%s'\n",
 987                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 988                         goto bail2;
 989                 }
 990
 991                 /*
 992                  * identify the selected protocol struct and set it
 993                  */
 994                 n = 0;
 995                 wsi->protocol = NULL;
 996                 while (this->protocols[n].callback) {
 997                         if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 998                                                this->protocols[n].name) == 0)
 999                                 wsi->protocol = &this->protocols[n];
1000                         n++;
1001                 }
1002
1003                 if (wsi->protocol == NULL) {
1004                         fprintf(stderr, "libwebsocket_client_handshake server "
1005                                         "requested protocol '%s', which we "
1006                                         "said we supported but we don't!\n",
1007                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
1008                         goto bail2;
1009                 }
1010
1011         check_accept:
1012                 /*
1013                  * Confirm his accept token is the one we precomputed
1014                  */
1015
1016                 if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1017                                           wsi->initial_handshake_hash_base64)) {
1018                         fprintf(stderr, "libwebsocket_client_handshake server "
1019                                 "sent bad ACCEPT '%s' vs computed '%s'\n",
1020                                 wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1021                                             wsi->initial_handshake_hash_base64);
1022                         goto bail2;
1023                 }
1024
1025                 /*
1026                  * Calculate the masking key to use when sending data to server
1027                  */
1028
1029                 strcpy((char *)buf, wsi->key_b64);
1030                 p = (char *)buf + strlen(wsi->key_b64);
1031                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1032                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1033                 strcpy(p, magic_websocket_04_masking_guid);
1034                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1035
1036                 /* allocate the per-connection user memory (if any) */
1037
1038                 if (wsi->protocol->per_session_data_size) {
1039                         wsi->user_space = malloc(
1040                                           wsi->protocol->per_session_data_size);
1041                         if (wsi->user_space  == NULL) {
1042                                 fprintf(stderr, "Out of memory for "
1043                                                            "conn user space\n");
1044                                 goto bail2;
1045                         }
1046                 } else
1047                         wsi->user_space = NULL;
1048
1049                 /* clear his proxy connection timeout */
1050
1051                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1052
1053                 /* mark him as being alive */
1054
1055                 wsi->state = WSI_STATE_ESTABLISHED;
1056                 wsi->mode = LWS_CONNMODE_WS_CLIENT;
1057
1058                 fprintf(stderr, "handshake OK for protocol %s\n",
1059                                                            wsi->protocol->name);
1060
1061                 /* call him back to inform him he is up */
1062
1063                 wsi->protocol->callback(this, wsi,
1064                                  LWS_CALLBACK_CLIENT_ESTABLISHED,
1065                                  wsi->user_space,
1066                                  NULL, 0);
1067
1068                 break;
1069
1070 bail3:
1071                 if (wsi->c_protocol)
1072                         free(wsi->c_protocol);
1073
1074 bail2:
1075                 libwebsocket_close_and_free_session(this, wsi,
1076                                                      LWS_CLOSE_STATUS_NOSTATUS);
1077                 return 1;
1078
1079
1080         case LWS_CONNMODE_WS_SERVING:
1081         case LWS_CONNMODE_WS_CLIENT:
1082
1083                 /* handle session socket closed */
1084
1085                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1086
1087                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1088                                 (void *)wsi, pollfd->fd);
1089
1090                         libwebsocket_close_and_free_session(this, wsi,
1091                                                      LWS_CLOSE_STATUS_NOSTATUS);
1092                         return 1;
1093                 }
1094
1095                 /* the guy requested a callback when it was OK to write */
1096
1097                 if (pollfd->revents & POLLOUT) {
1098
1099                         pollfd->events &= ~POLLOUT;
1100
1101                         /* external POLL support via protocol 0 */
1102                         this->protocols[0].callback(this, wsi,
1103                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1104                                 (void *)(long)wsi->sock, NULL, POLLOUT);
1105
1106                         wsi->protocol->callback(this, wsi,
1107                                 LWS_CALLBACK_CLIENT_WRITEABLE,
1108                                 wsi->user_space,
1109                                 NULL, 0);
1110                 }
1111
1112                 /* any incoming data ready? */
1113
1114                 if (!(pollfd->revents & POLLIN))
1115                         break;
1116
1117 #ifdef LWS_OPENSSL_SUPPORT
1118                 if (wsi->ssl)
1119                         n = SSL_read(wsi->ssl, buf, sizeof buf);
1120                 else
1121 #endif
1122                         n = recv(pollfd->fd, buf, sizeof buf, 0);
1123
1124                 if (n < 0) {
1125                         fprintf(stderr, "Socket read returned %d\n", n);
1126                         break;
1127                 }
1128                 if (!n) {
1129                         libwebsocket_close_and_free_session(this, wsi,
1130                                                      LWS_CLOSE_STATUS_NOSTATUS);
1131                         return 1;
1132                 }
1133
1134                 /* service incoming data */
1135
1136                 n = libwebsocket_read(this, wsi, buf, n);
1137                 if (n >= 0)
1138                         break;
1139
1140                 /* we closed wsi */
1141
1142                 return 1;
1143         }
1144
1145         return 0;
1146 }
1147
1148
1149 /**
1150  * libwebsocket_context_destroy() - Destroy the websocket context
1151  * @this:       Websocket context
1152  *
1153  *      This function closes any active connections and then frees the
1154  *      context.  After calling this, any further use of the context is
1155  *      undefined.
1156  */
1157 void
1158 libwebsocket_context_destroy(struct libwebsocket_context *this)
1159 {
1160         int n;
1161         int m;
1162         struct libwebsocket *wsi;
1163
1164         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1165                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1166                         wsi = this->fd_hashtable[n].wsi[m];
1167                         libwebsocket_close_and_free_session(this, wsi,
1168                                                     LWS_CLOSE_STATUS_GOINGAWAY);
1169                 }
1170
1171         close(this->fd_random);
1172
1173 #ifdef LWS_OPENSSL_SUPPORT
1174         if (this->ssl_ctx)
1175                 SSL_CTX_free(this->ssl_ctx);
1176         if (this->ssl_client_ctx)
1177                 SSL_CTX_free(this->ssl_client_ctx);
1178 #endif
1179
1180         free(this);
1181 }
1182
1183 /**
1184  * libwebsocket_service() - Service any pending websocket activity
1185  * @this:       Websocket context
1186  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
1187  *              service otherwise block and service immediately, returning
1188  *              after the timeout if nothing needed service.
1189  *
1190  *      This function deals with any pending websocket traffic, for three
1191  *      kinds of event.  It handles these events on both server and client
1192  *      types of connection the same.
1193  *
1194  *      1) Accept new connections to our context's server
1195  *
1196  *      2) Perform pending broadcast writes initiated from other forked
1197  *         processes (effectively serializing asynchronous broadcasts)
1198  *
1199  *      3) Call the receive callback for incoming frame data received by
1200  *          server or client connections.
1201  *
1202  *      You need to call this service function periodically to all the above
1203  *      functions to happen; if your application is single-threaded you can
1204  *      just call it in your main event loop.
1205  *
1206  *      Alternatively you can fork a new process that asynchronously handles
1207  *      calling this service in a loop.  In that case you are happy if this
1208  *      call blocks your thread until it needs to take care of something and
1209  *      would call it with a large nonzero timeout.  Your loop then takes no
1210  *      CPU while there is nothing happening.
1211  *
1212  *      If you are calling it in a single-threaded app, you don't want it to
1213  *      wait around blocking other things in your loop from happening, so you
1214  *      would call it with a timeout_ms of 0, so it returns immediately if
1215  *      nothing is pending, or as soon as it services whatever was pending.
1216  */
1217
1218
1219 int
1220 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
1221 {
1222         int n;
1223
1224         /* stay dead once we are dead */
1225
1226         if (this == NULL)
1227                 return 1;
1228
1229         /* wait for something to need service */
1230
1231         n = poll(this->fds, this->fds_count, timeout_ms);
1232         if (n == 0) /* poll timeout */
1233                 return 0;
1234
1235         if (n < 0) {
1236                 /*
1237                 fprintf(stderr, "Listen Socket dead\n");
1238                 */
1239                 return 1;
1240         }
1241
1242         /* handle accept on listening socket? */
1243
1244         for (n = 0; n < this->fds_count; n++)
1245                 if (this->fds[n].revents)
1246                         libwebsocket_service_fd(this, &this->fds[n]);
1247
1248         return 0;
1249 }
1250
1251 /**
1252  * libwebsocket_callback_on_writable() - Request a callback when this socket
1253  *                                       becomes able to be written to without
1254  *                                       blocking
1255  *
1256  * @this:       libwebsockets context
1257  * @wsi:        Websocket connection instance to get callback for
1258  */
1259
1260 int
1261 libwebsocket_callback_on_writable(struct libwebsocket_context *this,
1262                                                        struct libwebsocket *wsi)
1263 {
1264         int n;
1265
1266         for (n = 0; n < this->fds_count; n++)
1267                 if (this->fds[n].fd == wsi->sock) {
1268                         this->fds[n].events |= POLLOUT;
1269                         n = this->fds_count;
1270                 }
1271
1272         /* external POLL support via protocol 0 */
1273         this->protocols[0].callback(this, wsi,
1274                 LWS_CALLBACK_SET_MODE_POLL_FD,
1275                 (void *)(long)wsi->sock, NULL, POLLOUT);
1276
1277         return 1;
1278 }
1279
1280 /**
1281  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
1282  *                      all connections using the given protocol when it
1283  *                      becomes possible to write to each socket without
1284  *                      blocking in turn.
1285  *
1286  * @protocol:   Protocol whose connections will get callbacks
1287  */
1288
1289 int
1290 libwebsocket_callback_on_writable_all_protocol(
1291                                   const struct libwebsocket_protocols *protocol)
1292 {
1293         struct libwebsocket_context *this = protocol->owning_server;
1294         int n;
1295         int m;
1296         struct libwebsocket *wsi;
1297
1298         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1299
1300                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1301
1302                         wsi = this->fd_hashtable[n].wsi[m];
1303
1304                         if (wsi->protocol == protocol)
1305                                 libwebsocket_callback_on_writable(this, wsi);
1306                 }
1307         }
1308
1309         return 0;
1310 }
1311
1312 /**
1313  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
1314  *
1315  * You will not need this unless you are doing something special
1316  *
1317  * @wsi:        Websocket connection instance
1318  * @reason:     timeout reason
1319  * @secs:       how many seconds
1320  */
1321
1322 void
1323 libwebsocket_set_timeout(struct libwebsocket *wsi,
1324                                           enum pending_timeout reason, int secs)
1325 {
1326         struct timeval tv;
1327
1328         gettimeofday(&tv, NULL);
1329
1330         wsi->pending_timeout_limit = tv.tv_sec + secs;
1331         wsi->pending_timeout = reason;
1332 }
1333
1334
1335 /**
1336  * libwebsocket_get_socket_fd() - returns the socket file descriptor
1337  *
1338  * You will not need this unless you are doing something special
1339  *
1340  * @wsi:        Websocket connection instance
1341  */
1342
1343 int
1344 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
1345 {
1346         return wsi->sock;
1347 }
1348
1349 /**
1350  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
1351  *                              receieved packets.
1352  *
1353  * If the output side of a server process becomes choked, this allows flow
1354  * control for the input side.
1355  *
1356  * @wsi:        Websocket connection instance to get callback for
1357  * @enable:     0 = disable read servicing for this connection, 1 = enable
1358  */
1359
1360 int
1361 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
1362 {
1363         struct libwebsocket_context *this = wsi->protocol->owning_server;
1364         int n;
1365
1366         for (n = 0; n < this->fds_count; n++)
1367                 if (this->fds[n].fd == wsi->sock) {
1368                         if (enable)
1369                                 this->fds[n].events |= POLLIN;
1370                         else
1371                                 this->fds[n].events &= ~POLLIN;
1372
1373                         return 0;
1374                 }
1375
1376         if (enable)
1377                 /* external POLL support via protocol 0 */
1378                 this->protocols[0].callback(this, wsi,
1379                         LWS_CALLBACK_SET_MODE_POLL_FD,
1380                         (void *)(long)wsi->sock, NULL, POLLIN);
1381         else
1382                 /* external POLL support via protocol 0 */
1383                 this->protocols[0].callback(this, wsi,
1384                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1385                         (void *)(long)wsi->sock, NULL, POLLIN);
1386
1387
1388         fprintf(stderr, "libwebsocket_callback_on_writable "
1389                                                      "unable to find socket\n");
1390         return 1;
1391 }
1392
1393 /**
1394  * libwebsocket_canonical_hostname() - returns this host's hostname
1395  *
1396  * This is typically used by client code to fill in the host parameter
1397  * when making a client connection.  You can only call it after the context
1398  * has been created.
1399  *
1400  * @this:       Websocket context
1401  */
1402
1403
1404 extern const char *
1405 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
1406 {
1407         return (const char *)this->canonical_hostname;
1408 }
1409
1410
1411 static void sigpipe_handler(int x)
1412 {
1413 }
1414
1415 #ifdef LWS_OPENSSL_SUPPORT
1416 static int
1417 OpenSSL_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
1418 {
1419
1420         SSL *ssl;
1421         int n;
1422 //      struct libwebsocket_context *this;
1423
1424         ssl = X509_STORE_CTX_get_ex_data(x509_ctx,
1425                 SSL_get_ex_data_X509_STORE_CTX_idx());
1426
1427         /*
1428          * !!! can't get this->openssl_websocket_private_data_index
1429          * can't store as a static either
1430          */
1431 //      this = SSL_get_ex_data(ssl, this->openssl_websocket_private_data_index);
1432
1433         n = this->protocols[0].callback(NULL, NULL,
1434                 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
1435                                                    x509_ctx, ssl, preverify_ok);
1436
1437         /* convert return code from 0 = OK to 1 = OK */
1438
1439         if (!n)
1440                 n = 1;
1441         else
1442                 n = 0;
1443
1444         return n;
1445 }
1446 #endif
1447
1448
1449 /**
1450  * libwebsocket_create_context() - Create the websocket handler
1451  * @port:       Port to listen on... you can use 0 to suppress listening on
1452  *              any port, that's what you want if you are not running a
1453  *              websocket server at all but just using it as a client
1454  * @interface:  NULL to bind the listen socket to all interfaces, or the
1455  *              interface name, eg, "eth2"
1456  * @protocols:  Array of structures listing supported protocols and a protocol-
1457  *              specific callback for each one.  The list is ended with an
1458  *              entry that has a NULL callback pointer.
1459  *              It's not const because we write the owning_server member
1460  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
1461  *                      to listen using SSL, set to the filepath to fetch the
1462  *                      server cert from, otherwise NULL for unencrypted
1463  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
1464  *                      else ignored
1465  * @gid:        group id to change to after setting listen socket, or -1.
1466  * @uid:        user id to change to after setting listen socket, or -1.
1467  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
1468  *
1469  *      This function creates the listening socket and takes care
1470  *      of all initialization in one step.
1471  *
1472  *      After initialization, it returns a struct libwebsocket_context * that
1473  *      represents this server.  After calling, user code needs to take care
1474  *      of calling libwebsocket_service() with the context pointer to get the
1475  *      server's sockets serviced.  This can be done in the same process context
1476  *      or a forked process, or another thread,
1477  *
1478  *      The protocol callback functions are called for a handful of events
1479  *      including http requests coming in, websocket connections becoming
1480  *      established, and data arriving; it's also called periodically to allow
1481  *      async transmission.
1482  *
1483  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
1484  *      at that time websocket protocol has not been negotiated.  Other
1485  *      protocols after the first one never see any HTTP callack activity.
1486  *
1487  *      The server created is a simple http server by default; part of the
1488  *      websocket standard is upgrading this http connection to a websocket one.
1489  *
1490  *      This allows the same server to provide files like scripts and favicon /
1491  *      images or whatever over http and dynamic data over websockets all in
1492  *      one place; they're all handled in the user callback.
1493  */
1494
1495 struct libwebsocket_context *
1496 libwebsocket_create_context(int port, const char *interface,
1497                                struct libwebsocket_protocols *protocols,
1498                                const char *ssl_cert_filepath,
1499                                const char *ssl_private_key_filepath,
1500                                int gid, int uid, unsigned int options)
1501 {
1502         int n;
1503         int sockfd = 0;
1504         int fd;
1505         struct sockaddr_in serv_addr, cli_addr;
1506         int opt = 1;
1507         struct libwebsocket_context *this = NULL;
1508         unsigned int slen;
1509         char *p;
1510         char hostname[1024];
1511         struct hostent *he;
1512         struct libwebsocket *wsi;
1513
1514 #ifdef LWS_OPENSSL_SUPPORT
1515         SSL_METHOD *method;
1516         char ssl_err_buf[512];
1517 #endif
1518
1519         this = malloc(sizeof(struct libwebsocket_context));
1520         if (!this) {
1521                 fprintf(stderr, "No memory for websocket context\n");
1522                 return NULL;
1523         }
1524         this->protocols = protocols;
1525         this->listen_port = port;
1526         this->http_proxy_port = 0;
1527         this->http_proxy_address[0] = '\0';
1528         this->options = options;
1529         this->fds_count = 0;
1530
1531         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
1532         if (this->fd_random < 0) {
1533                 fprintf(stderr, "Unable to open random device %s %d\n",
1534                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
1535                 return NULL;
1536         }
1537
1538         /* find canonical hostname */
1539
1540         hostname[(sizeof hostname) - 1] = '\0';
1541         gethostname(hostname, (sizeof hostname) - 1);
1542         he = gethostbyname(hostname);
1543         if (he) {
1544                 strncpy(this->canonical_hostname, he->h_name,
1545                                            sizeof this->canonical_hostname - 1);
1546                 this->canonical_hostname[sizeof this->canonical_hostname - 1] =
1547                                                                            '\0';
1548         } else
1549                 strncpy(this->canonical_hostname, hostname,
1550                                            sizeof this->canonical_hostname - 1);
1551
1552         /* split the proxy ads:port if given */
1553
1554         p = getenv("http_proxy");
1555         if (p) {
1556                 strncpy(this->http_proxy_address, p,
1557                                            sizeof this->http_proxy_address - 1);
1558                 this->http_proxy_address[
1559                                     sizeof this->http_proxy_address - 1] = '\0';
1560
1561                 p = strchr(this->http_proxy_address, ':');
1562                 if (p == NULL) {
1563                         fprintf(stderr, "http_proxy needs to be ads:port\n");
1564                         return NULL;
1565                 }
1566                 *p = '\0';
1567                 this->http_proxy_port = atoi(p + 1);
1568
1569                 fprintf(stderr, "Using proxy %s:%u\n",
1570                                 this->http_proxy_address,
1571                                                         this->http_proxy_port);
1572         }
1573
1574         if (port) {
1575
1576 #ifdef LWS_OPENSSL_SUPPORT
1577                 this->use_ssl = ssl_cert_filepath != NULL &&
1578                                                ssl_private_key_filepath != NULL;
1579                 if (this->use_ssl)
1580                         fprintf(stderr, " Compiled with SSL support, "
1581                                                                   "using it\n");
1582                 else
1583                         fprintf(stderr, " Compiled with SSL support, "
1584                                                               "not using it\n");
1585
1586 #else
1587                 if (ssl_cert_filepath != NULL &&
1588                                              ssl_private_key_filepath != NULL) {
1589                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
1590                         return NULL;
1591                 }
1592                 fprintf(stderr, " Compiled without SSL support, "
1593                                                        "serving unencrypted\n");
1594 #endif
1595         }
1596
1597         /* ignore SIGPIPE */
1598
1599         signal(SIGPIPE, sigpipe_handler);
1600
1601
1602 #ifdef LWS_OPENSSL_SUPPORT
1603
1604         /* basic openssl init */
1605
1606         SSL_library_init();
1607
1608         OpenSSL_add_all_algorithms();
1609         SSL_load_error_strings();
1610
1611         this->openssl_websocket_private_data_index =
1612                 SSL_get_ex_new_index(0, "libwebsockets", NULL, NULL, NULL);
1613
1614         /*
1615          * Firefox insists on SSLv23 not SSLv3
1616          * Konq disables SSLv2 by default now, SSLv23 works
1617          */
1618
1619         method = (SSL_METHOD *)SSLv23_server_method();
1620         if (!method) {
1621                 fprintf(stderr, "problem creating ssl method: %s\n",
1622                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1623                 return NULL;
1624         }
1625         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
1626         if (!this->ssl_ctx) {
1627                 fprintf(stderr, "problem creating ssl context: %s\n",
1628                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1629                 return NULL;
1630         }
1631
1632         /* client context */
1633
1634         method = (SSL_METHOD *)SSLv23_client_method();
1635         if (!method) {
1636                 fprintf(stderr, "problem creating ssl method: %s\n",
1637                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1638                 return NULL;
1639         }
1640         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
1641         if (!this->ssl_client_ctx) {
1642                 fprintf(stderr, "problem creating ssl context: %s\n",
1643                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1644                 return NULL;
1645         }
1646
1647
1648         /* openssl init for cert verification (used with client sockets) */
1649
1650         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
1651                                                     LWS_OPENSSL_CLIENT_CERTS)) {
1652                 fprintf(stderr, "Unable to load SSL Client certs from %s "
1653                         "(set by --with-client-cert-dir= in configure) -- "
1654                         " client ssl isn't going to work",
1655                                                       LWS_OPENSSL_CLIENT_CERTS);
1656         }
1657
1658         /*
1659          * callback allowing user code to load extra verification certs
1660          * helping the client to verify server identity
1661          */
1662
1663         this->protocols[0].callback(this, NULL,
1664                 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
1665                 this->ssl_client_ctx, NULL, 0);
1666
1667         /* as a server, are we requiring clients to identify themselves? */
1668
1669         if (options & LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT) {
1670
1671                 /* absolutely require the client cert */
1672
1673                 SSL_CTX_set_verify(this->ssl_ctx,
1674                        SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
1675                                                        OpenSSL_verify_callback);
1676
1677                 /*
1678                  * give user code a chance to load certs into the server
1679                  * allowing it to verify incoming client certs
1680                  */
1681
1682                 this->protocols[0].callback(this, NULL,
1683                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
1684                                                         this->ssl_ctx, NULL, 0);
1685         }
1686
1687         if (this->use_ssl) {
1688
1689                 /* openssl init for server sockets */
1690
1691                 /* set the local certificate from CertFile */
1692                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
1693                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
1694                 if (n != 1) {
1695                         fprintf(stderr, "problem getting cert '%s': %s\n",
1696                                 ssl_cert_filepath,
1697                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1698                         return NULL;
1699                 }
1700                 /* set the private key from KeyFile */
1701                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
1702                                                 ssl_private_key_filepath,
1703                                                        SSL_FILETYPE_PEM) != 1) {
1704                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
1705                                                 ssl_private_key_filepath,
1706                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1707                         return NULL;
1708                 }
1709                 /* verify private key */
1710                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
1711                         fprintf(stderr, "Private SSL key doesn't match cert\n");
1712                         return NULL;
1713                 }
1714
1715                 /* SSL is happy and has a cert it's content with */
1716         }
1717 #endif
1718
1719         /* selftest */
1720
1721         if (lws_b64_selftest())
1722                 return NULL;
1723
1724         /* fd hashtable init */
1725
1726         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1727                 this->fd_hashtable[n].length = 0;
1728
1729         /* set up our external listening socket we serve on */
1730
1731         if (port) {
1732
1733                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1734                 if (sockfd < 0) {
1735                         fprintf(stderr, "ERROR opening socket");
1736                         return NULL;
1737                 }
1738
1739                 /* allow us to restart even if old sockets in TIME_WAIT */
1740                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1741
1742                 bzero((char *) &serv_addr, sizeof(serv_addr));
1743                 serv_addr.sin_family = AF_INET;
1744                 if (interface == NULL)
1745                         serv_addr.sin_addr.s_addr = INADDR_ANY;
1746                 else
1747                         interface_to_sa(interface, &serv_addr,
1748                                                 sizeof(serv_addr));
1749                 serv_addr.sin_port = htons(port);
1750
1751                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
1752                                                              sizeof(serv_addr));
1753                 if (n < 0) {
1754                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1755                                                                 port, n, errno);
1756                         return NULL;
1757                 }
1758
1759                 wsi = malloc(sizeof(struct libwebsocket));
1760                 memset(wsi, 0, sizeof (struct libwebsocket));
1761                 wsi->sock = sockfd;
1762                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
1763                 insert_wsi(this, wsi);
1764
1765                 listen(sockfd, 5);
1766                 fprintf(stderr, " Listening on port %d\n", port);
1767
1768                 /* list in the internal poll array */
1769
1770                 this->fds[this->fds_count].fd = sockfd;
1771                 this->fds[this->fds_count++].events = POLLIN;
1772
1773                 /* external POLL support via protocol 0 */
1774                 this->protocols[0].callback(this, wsi,
1775                         LWS_CALLBACK_ADD_POLL_FD,
1776                         (void *)(long)sockfd, NULL, POLLIN);
1777
1778         }
1779
1780         /* drop any root privs for this process */
1781
1782         if (gid != -1)
1783                 if (setgid(gid))
1784                         fprintf(stderr, "setgid: %s\n", strerror(errno));
1785         if (uid != -1)
1786                 if (setuid(uid))
1787                         fprintf(stderr, "setuid: %s\n", strerror(errno));
1788
1789
1790         /* set up our internal broadcast trigger sockets per-protocol */
1791
1792         for (this->count_protocols = 0;
1793                         protocols[this->count_protocols].callback;
1794                                                       this->count_protocols++) {
1795                 protocols[this->count_protocols].owning_server = this;
1796                 protocols[this->count_protocols].protocol_index =
1797                                                           this->count_protocols;
1798
1799                 fd = socket(AF_INET, SOCK_STREAM, 0);
1800                 if (fd < 0) {
1801                         fprintf(stderr, "ERROR opening socket");
1802                         return NULL;
1803                 }
1804
1805                 /* allow us to restart even if old sockets in TIME_WAIT */
1806                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1807
1808                 bzero((char *) &serv_addr, sizeof(serv_addr));
1809                 serv_addr.sin_family = AF_INET;
1810                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1811                 serv_addr.sin_port = 0; /* pick the port for us */
1812
1813                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
1814                 if (n < 0) {
1815                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1816                                                                 port, n, errno);
1817                         return NULL;
1818                 }
1819
1820                 slen = sizeof cli_addr;
1821                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
1822                 if (n < 0) {
1823                         fprintf(stderr, "getsockname failed\n");
1824                         return NULL;
1825                 }
1826                 protocols[this->count_protocols].broadcast_socket_port =
1827                                                        ntohs(cli_addr.sin_port);
1828                 listen(fd, 5);
1829
1830                 debug("  Protocol %s broadcast socket %d\n",
1831                                 protocols[this->count_protocols].name,
1832                                                       ntohs(cli_addr.sin_port));
1833
1834                 /* dummy wsi per broadcast proxy socket */
1835
1836                 wsi = malloc(sizeof(struct libwebsocket));
1837                 memset(wsi, 0, sizeof (struct libwebsocket));
1838                 wsi->sock = fd;
1839                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
1840                 /* note which protocol we are proxying */
1841                 wsi->protocol_index_for_broadcast_proxy = this->count_protocols;
1842                 insert_wsi(this, wsi);
1843
1844                 /* list in internal poll array */
1845
1846                 this->fds[this->fds_count].fd = fd;
1847                 this->fds[this->fds_count].events = POLLIN;
1848                 this->fds[this->fds_count].revents = 0;
1849                 this->fds_count++;
1850
1851                 /* external POLL support via protocol 0 */
1852                 this->protocols[0].callback(this, wsi,
1853                         LWS_CALLBACK_ADD_POLL_FD,
1854                         (void *)(long)fd, NULL, POLLIN);
1855         }
1856
1857         return this;
1858 }
1859
1860
1861 #ifndef LWS_NO_FORK
1862
1863 /**
1864  * libwebsockets_fork_service_loop() - Optional helper function forks off
1865  *                                a process for the websocket server loop.
1866  *                              You don't have to use this but if not, you
1867  *                              have to make sure you are calling
1868  *                              libwebsocket_service periodically to service
1869  *                              the websocket traffic
1870  * @this:       server context returned by creation function
1871  */
1872
1873 int
1874 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
1875 {
1876         int fd;
1877         struct sockaddr_in cli_addr;
1878         int n;
1879         int p;
1880
1881         n = fork();
1882         if (n < 0)
1883                 return n;
1884
1885         if (!n) {
1886
1887                 /* main process context */
1888
1889                 /*
1890                  * set up the proxy sockets to allow broadcast from
1891                  * service process context
1892                  */
1893
1894                 for (p = 0; p < this->count_protocols; p++) {
1895                         fd = socket(AF_INET, SOCK_STREAM, 0);
1896                         if (fd < 0) {
1897                                 fprintf(stderr, "Unable to create socket\n");
1898                                 return -1;
1899                         }
1900                         cli_addr.sin_family = AF_INET;
1901                         cli_addr.sin_port = htons(
1902                              this->protocols[p].broadcast_socket_port);
1903                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1904                         n = connect(fd, (struct sockaddr *)&cli_addr,
1905                                                                sizeof cli_addr);
1906                         if (n < 0) {
1907                                 fprintf(stderr, "Unable to connect to "
1908                                                 "broadcast socket %d, %s\n",
1909                                                 n, strerror(errno));
1910                                 return -1;
1911                         }
1912
1913                         this->protocols[p].broadcast_socket_user_fd = fd;
1914                 }
1915
1916                 return 0;
1917         }
1918
1919         /* we want a SIGHUP when our parent goes down */
1920         prctl(PR_SET_PDEATHSIG, SIGHUP);
1921
1922         /* in this forked process, sit and service websocket connections */
1923
1924         while (1)
1925                 if (libwebsocket_service(this, 1000))
1926                         return -1;
1927
1928         return 0;
1929 }
1930
1931 #endif
1932
1933 /**
1934  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1935  *                                connection.
1936  * @wsi:        pointer to struct websocket you want to know the protocol of
1937  *
1938  *
1939  *      This is useful to get the protocol to broadcast back to from inside
1940  * the callback.
1941  */
1942
1943 const struct libwebsocket_protocols *
1944 libwebsockets_get_protocol(struct libwebsocket *wsi)
1945 {
1946         return wsi->protocol;
1947 }
1948
1949 /**
1950  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1951  *                                connections of the given protocol.
1952  * @protocol:   pointer to the protocol you will broadcast to all members of
1953  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1954  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1955  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1956  *              case you are calling this function from callback context.
1957  * @len:        length of payload data in buf, starting from buf.
1958  *
1959  *      This function allows bulk sending of a packet to every connection using
1960  * the given protocol.  It does not send the data directly; instead it calls
1961  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1962  * wants to actually send the data for that connection, the callback itself
1963  * should call libwebsocket_write().
1964  *
1965  * libwebsockets_broadcast() can be called from another fork context without
1966  * having to take any care about data visibility between the processes, it'll
1967  * "just work".
1968  */
1969
1970
1971 int
1972 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1973                                                  unsigned char *buf, size_t len)
1974 {
1975         struct libwebsocket_context *this = protocol->owning_server;
1976         int n;
1977         int m;
1978         struct libwebsocket * wsi;
1979
1980         if (!protocol->broadcast_socket_user_fd) {
1981                 /*
1982                  * We are either running unforked / flat, or we are being
1983                  * called from poll thread context
1984                  * eg, from a callback.  In that case don't use sockets for
1985                  * broadcast IPC (since we can't open a socket connection to
1986                  * a socket listening on our own thread) but directly do the
1987                  * send action.
1988                  *
1989                  * Locking is not needed because we are by definition being
1990                  * called in the poll thread context and are serialized.
1991                  */
1992
1993                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1994
1995                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
1996
1997                                 wsi = this->fd_hashtable[n].wsi[m];
1998
1999                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
2000                                         continue;
2001
2002                                 /*
2003                                  * never broadcast to
2004                                  * non-established connections
2005                                  */
2006                                 if (wsi->state != WSI_STATE_ESTABLISHED)
2007                                         continue;
2008
2009                                 /* only broadcast to guys using
2010                                  * requested protocol
2011                                  */
2012                                 if (wsi->protocol != protocol)
2013                                         continue;
2014
2015                                 wsi->protocol->callback(this, wsi,
2016                                          LWS_CALLBACK_BROADCAST,
2017                                          wsi->user_space,
2018                                          buf, len);
2019                         }
2020                 }
2021
2022                 return 0;
2023         }
2024
2025         /*
2026          * We're being called from a different process context than the server
2027          * loop.  Instead of broadcasting directly, we send our
2028          * payload on a socket to do the IPC; the server process will serialize
2029          * the broadcast action in its main poll() loop.
2030          *
2031          * There's one broadcast socket listening for each protocol supported
2032          * set up when the websocket server initializes
2033          */
2034
2035         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
2036
2037         return n;
2038 }