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 /* file descriptor hash management */
  25
  26 struct libwebsocket *
  27 wsi_from_fd(struct libwebsocket_context *this, int fd)
  28 {
  29         int h = LWS_FD_HASH(fd);
  30         int n = 0;
  31
  32         for (n = 0; n < this->fd_hashtable[h].length; n++)
  33                 if (this->fd_hashtable[h].wsi[n]->sock == fd)
  34                         return this->fd_hashtable[h].wsi[n];
  35
  36         return NULL;
  37 }
  38
  39 int
  40 insert_wsi(struct libwebsocket_context *this, struct libwebsocket *wsi)
  41 {
  42         int h = LWS_FD_HASH(wsi->sock);
  43
  44         if (this->fd_hashtable[h].length == MAX_CLIENTS - 1) {
  45                 fprintf(stderr, "hash table overflow\n");
  46                 return 1;
  47         }
  48
  49         this->fd_hashtable[h].wsi[this->fd_hashtable[h].length++] = wsi;
  50
  51         return 0;
  52 }
  53
  54 int
  55 delete_from_fd(struct libwebsocket_context *this, int fd)
  56 {
  57         int h = LWS_FD_HASH(fd);
  58         int n = 0;
  59
  60         for (n = 0; n < this->fd_hashtable[h].length; n++)
  61                 if (this->fd_hashtable[h].wsi[n]->sock == fd) {
  62                         while (n < this->fd_hashtable[h].length) {
  63                                 this->fd_hashtable[h].wsi[n] =
  64                                                this->fd_hashtable[h].wsi[n + 1];
  65                                 n++;
  66                         }
  67                         this->fd_hashtable[h].length--;
  68
  69                         return 0;
  70                 }
  71
  72         fprintf(stderr, "Failed to find fd %d requested for "
  73                                                    "delete in hashtable\n", fd);
  74         return 1;
  75 }
  76
  77
  78 void
  79 libwebsocket_close_and_free_session(struct libwebsocket *wsi)
  80 {
  81         int n;
  82         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
  83                                                   LWS_SEND_BUFFER_POST_PADDING];
  84
  85         if ((unsigned long)wsi < LWS_MAX_PROTOCOLS)
  86                 return;
  87
  88         n = wsi->state;
  89
  90         if (n == WSI_STATE_DEAD_SOCKET)
  91                 return;
  92
  93         /*
  94          * signal we are closing, libsocket_write will
  95          * add any necessary version-specific stuff.  If the write fails,
  96          * no worries we are closing anyway.  If we didn't initiate this
  97          * close, then our state has been changed to
  98          * WSI_STATE_RETURNED_CLOSE_ALREADY and we can skip this
  99          */
 100
 101         if (n == WSI_STATE_ESTABLISHED)
 102                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
 103                                                                LWS_WRITE_CLOSE);
 104
 105         wsi->state = WSI_STATE_DEAD_SOCKET;
 106
 107         if (wsi->protocol->callback && n == WSI_STATE_ESTABLISHED)
 108                 wsi->protocol->callback(wsi, LWS_CALLBACK_CLOSED,
 109                                                       wsi->user_space, NULL, 0);
 110
 111         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 112                 if (wsi->utf8_token[n].token)
 113                         free(wsi->utf8_token[n].token);
 114
 115 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 116
 117 #ifdef LWS_OPENSSL_SUPPORT
 118         if (wsi->ssl) {
 119                 n = SSL_get_fd(wsi->ssl);
 120                 SSL_shutdown(wsi->ssl);
 121                 close(n);
 122                 SSL_free(wsi->ssl);
 123         } else {
 124 #endif
 125                 shutdown(wsi->sock, SHUT_RDWR);
 126                 close(wsi->sock);
 127 #ifdef LWS_OPENSSL_SUPPORT
 128         }
 129 #endif
 130         if (wsi->user_space)
 131                 free(wsi->user_space);
 132
 133         free(wsi);
 134 }
 135
 136 /**
 137  * libwebsockets_get_peer_addresses() - Get client address information
 138  * @fd:         Connection socket descriptor
 139  * @name:       Buffer to take client address name
 140  * @name_len:   Length of client address name buffer
 141  * @rip:        Buffer to take client address IP qotted quad
 142  * @rip_len:    Length of client address IP buffer
 143  *
 144  *      This function fills in @name and @rip with the name and IP of
 145  *      the client connected with socket descriptor @fd.  Names may be
 146  *      truncated if there is not enough room.  If either cannot be
 147  *      determined, they will be returned as valid zero-length strings.
 148  */
 149
 150 void
 151 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 152                                         char *rip, int rip_len)
 153 {
 154         unsigned int len;
 155         struct sockaddr_in sin;
 156         struct hostent *host;
 157         struct hostent *host1;
 158         char ip[128];
 159         char *p;
 160         int n;
 161
 162         rip[0] = '\0';
 163         name[0] = '\0';
 164
 165         len = sizeof sin;
 166         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 167                 perror("getpeername");
 168                 return;
 169         }
 170
 171         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 172                                                                        AF_INET);
 173         if (host == NULL) {
 174                 perror("gethostbyaddr");
 175                 return;
 176         }
 177
 178         strncpy(name, host->h_name, name_len);
 179         name[name_len - 1] = '\0';
 180
 181         host1 = gethostbyname(host->h_name);
 182         if (host1 == NULL)
 183                 return;
 184         p = (char *)host1;
 185         n = 0;
 186         while (p != NULL) {
 187                 p = host1->h_addr_list[n++];
 188                 if (p == NULL)
 189                         continue;
 190                 if (host1->h_addrtype != AF_INET)
 191                         continue;
 192
 193                 sprintf(ip, "%d.%d.%d.%d",
 194                                 p[0], p[1], p[2], p[3]);
 195                 p = NULL;
 196                 strncpy(rip, ip, rip_len);
 197                 rip[rip_len - 1] = '\0';
 198         }
 199 }
 200
 201 /**
 202  * libwebsocket_service_fd() - Service polled socket with something waiting
 203  * @this:       Websocket context
 204  * @pollfd:     The pollfd entry describing the socket fd and which events
 205  *              happened.
 206  *
 207  *      This function closes any active connections and then frees the
 208  *      context.  After calling this, any further use of the context is
 209  *      undefined.
 210  */
 211
 212 int
 213 libwebsocket_service_fd(struct libwebsocket_context *this,
 214                                                           struct pollfd *pollfd)
 215 {
 216         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
 217                                                   LWS_SEND_BUFFER_POST_PADDING];
 218         struct libwebsocket *wsi = wsi_from_fd(this, pollfd->fd);
 219         struct libwebsocket *new_wsi;
 220         int n;
 221         int m;
 222         size_t len;
 223         int accept_fd;
 224         unsigned int clilen;
 225         struct sockaddr_in cli_addr;
 226
 227         if (wsi == NULL)
 228                 return 1;
 229
 230         switch (wsi->mode) {
 231         case LWS_CONNMODE_SERVER_LISTENER:
 232
 233                 /* pollin means a client has connected to us then */
 234
 235                 if (!pollfd->revents & POLLIN)
 236                         break;
 237
 238                 /* listen socket got an unencrypted connection... */
 239
 240                 clilen = sizeof(cli_addr);
 241                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 242                                                                        &clilen);
 243                 if (accept_fd < 0) {
 244                         fprintf(stderr, "ERROR on accept");
 245                         break;
 246                 }
 247
 248                 if (this->fds_count >= MAX_CLIENTS) {
 249                         fprintf(stderr, "too busy to accept new client\n");
 250                         close(accept_fd);
 251                         break;
 252                 }
 253
 254                 /*
 255                  * look at who we connected to and give user code a chance
 256                  * to reject based on client IP.  There's no protocol selected
 257                  * yet so we issue this to protocols[0]
 258                  */
 259
 260                 if ((this->protocols[0].callback)(wsi,
 261                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 262                                              (void*)(long)accept_fd, NULL, 0)) {
 263                         fprintf(stderr, "Callback denied network connection\n");
 264                         close(accept_fd);
 265                         break;
 266                 }
 267
 268                 /* accepting connection to main listener */
 269
 270                 new_wsi = malloc(sizeof(struct libwebsocket));
 271                 if (new_wsi == NULL) {
 272                         fprintf(stderr, "Out of memory for new connection\n");
 273                         break;
 274                 }
 275
 276                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 277                 new_wsi->sock = accept_fd;
 278
 279 #ifdef LWS_OPENSSL_SUPPORT
 280                 new_wsi->ssl = NULL;
 281                 this->ssl_ctx = NULL;
 282
 283                 if (this->use_ssl) {
 284
 285                         new_wsi->ssl = SSL_new(this->ssl_ctx);
 286                         if (new_wsi->ssl == NULL) {
 287                                 fprintf(stderr, "SSL_new failed: %s\n",
 288                                     ERR_error_string(SSL_get_error(
 289                                     new_wsi->ssl, 0), NULL));
 290                                 free(new_wsi);
 291                                 break;
 292                         }
 293
 294                         SSL_set_fd(new_wsi->ssl, accept_fd);
 295
 296                         n = SSL_accept(new_wsi->ssl);
 297                         if (n != 1) {
 298                                 /*
 299                                  * browsers seem to probe with various
 300                                  * ssl params which fail then retry
 301                                  * and succeed
 302                                  */
 303                                 debug("SSL_accept failed skt %u: %s\n",
 304                                       pollfd->fd,
 305                                       ERR_error_string(SSL_get_error(
 306                                       new_wsi->ssl, n), NULL));
 307                                 SSL_free(
 308                                        new_wsi->ssl);
 309                                 free(new_wsi);
 310                                 break;
 311                         }
 312                         debug("accepted new SSL conn  "
 313                               "port %u on fd=%d SSL ver %s\n",
 314                                 ntohs(cli_addr.sin_port), accept_fd,
 315                                   SSL_get_version(new_wsi->ssl));
 316
 317                 } else
 318 #endif
 319                         debug("accepted new conn  port %u on fd=%d\n",
 320                                           ntohs(cli_addr.sin_port), accept_fd);
 321
 322                 /* intialize the instance struct */
 323
 324                 new_wsi->state = WSI_STATE_HTTP;
 325                 new_wsi->name_buffer_pos = 0;
 326                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 327
 328                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 329                         new_wsi->utf8_token[n].token = NULL;
 330                         new_wsi->utf8_token[n].token_len = 0;
 331                 }
 332
 333                 /*
 334                  * these can only be set once the protocol is known
 335                  * we set an unestablished connection's protocol pointer
 336                  * to the start of the supported list, so it can look
 337                  * for matching ones during the handshake
 338                  */
 339                 new_wsi->protocol = this->protocols;
 340                 new_wsi->user_space = NULL;
 341
 342                 /*
 343                  * Default protocol is 76 / 00
 344                  * After 76, there's a header specified to inform which
 345                  * draft the client wants, when that's seen we modify
 346                  * the individual connection's spec revision accordingly
 347                  */
 348                 new_wsi->ietf_spec_revision = 0;
 349
 350                 insert_wsi(this, new_wsi);
 351
 352                 /*
 353                  * make sure NO events are seen yet on this new socket
 354                  * (otherwise we inherit old fds[client].revents from
 355                  * previous socket there and die mysteriously! )
 356                  */
 357                 this->fds[this->fds_count].revents = 0;
 358
 359                 this->fds[this->fds_count].events = POLLIN;
 360                 this->fds[this->fds_count++].fd = accept_fd;
 361
 362                 /* external POLL support via protocol 0 */
 363                 this->protocols[0].callback(new_wsi,
 364                         LWS_CALLBACK_ADD_POLL_FD,
 365                         (void *)(long)accept_fd, NULL, POLLIN);
 366
 367                 break;
 368
 369         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 370
 371                 /* as we are listening, POLLIN means accept() is needed */
 372
 373                 if (!pollfd->revents & POLLIN)
 374                         break;
 375
 376                 /* listen socket got an unencrypted connection... */
 377
 378                 clilen = sizeof(cli_addr);
 379                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 380                                                                        &clilen);
 381                 if (accept_fd < 0) {
 382                         fprintf(stderr, "ERROR on accept");
 383                         break;
 384                 }
 385
 386                 if (this->fds_count >= MAX_CLIENTS) {
 387                         fprintf(stderr, "too busy to accept new broadcast "
 388                                                               "proxy client\n");
 389                         close(accept_fd);
 390                         break;
 391                 }
 392
 393                 /* create a dummy wsi for the connection and add it */
 394
 395                 new_wsi = malloc(sizeof(struct libwebsocket));
 396                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 397                 new_wsi->sock = accept_fd;
 398                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 399                 new_wsi->state = WSI_STATE_ESTABLISHED;
 400                 /* note which protocol we are proxying */
 401                 new_wsi->protocol_index_for_broadcast_proxy =
 402                                         wsi->protocol_index_for_broadcast_proxy;
 403                 insert_wsi(this, new_wsi);
 404
 405                 /* add connected socket to internal poll array */
 406
 407                 this->fds[this->fds_count].revents = 0;
 408                 this->fds[this->fds_count].events = POLLIN;
 409                 this->fds[this->fds_count++].fd = accept_fd;
 410
 411                 /* external POLL support via protocol 0 */
 412                 this->protocols[0].callback(new_wsi,
 413                         LWS_CALLBACK_ADD_POLL_FD,
 414                         (void *)(long)accept_fd, NULL, POLLIN);
 415
 416                 break;
 417
 418         case LWS_CONNMODE_BROADCAST_PROXY:
 419
 420                 /* handle session socket closed */
 421
 422                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 423
 424                         debug("Session Socket %p (fd=%d) dead\n",
 425                                 (void *)wsi, accept_fd);
 426
 427                         libwebsocket_close_and_free_session(wsi);
 428                         goto nuke_this;
 429                 }
 430
 431                 /* the guy requested a callback when it was OK to write */
 432
 433                 if (pollfd->revents & POLLOUT) {
 434
 435                         /* one shot */
 436
 437                         pollfd->events &= ~POLLOUT;
 438
 439                         /* external POLL support via protocol 0 */
 440                         this->protocols[0].callback(wsi,
 441                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 442                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 443
 444                         wsi->protocol->callback(wsi,
 445                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 446                                 wsi->user_space,
 447                                 NULL, 0);
 448                 }
 449
 450                 /* any incoming data ready? */
 451
 452                 if (!(pollfd->revents & POLLIN))
 453                         break;
 454
 455                 /* get the issued broadcast payload from the socket */
 456
 457                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 458                                                          MAX_BROADCAST_PAYLOAD);
 459                 if (len < 0) {
 460                         fprintf(stderr, "Error reading broadcast payload\n");
 461                         break;;
 462                 }
 463
 464                 /* broadcast it to all guys with this protocol index */
 465
 466                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 467
 468                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
 469
 470                                 new_wsi = this->fd_hashtable[n].wsi[m];
 471
 472                                 /* only to clients we are serving to */
 473
 474                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 475                                         continue;
 476
 477                                 /*
 478                                  * never broadcast to non-established
 479                                  * connection
 480                                  */
 481
 482                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 483                                         continue;
 484
 485                                 /*
 486                                  * only broadcast to connections using
 487                                  * the requested protocol
 488                                  */
 489
 490                                 if (new_wsi->protocol->protocol_index !=
 491                                         wsi->protocol_index_for_broadcast_proxy)
 492                                         continue;
 493
 494                                 /* broadcast it to this connection */
 495
 496                                 new_wsi->protocol->callback(new_wsi,
 497                                         LWS_CALLBACK_BROADCAST,
 498                                         new_wsi->user_space,
 499                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 500                         }
 501                 }
 502                 break;
 503
 504         case LWS_CONNMODE_WS_SERVING:
 505         case LWS_CONNMODE_WS_CLIENT:
 506
 507                 /* handle session socket closed */
 508
 509                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 510
 511                         debug("Session Socket %p (fd=%d) dead\n",
 512                                 (void *)wsi, pollfd->fd);
 513
 514                         libwebsocket_close_and_free_session(wsi);
 515                         goto nuke_this;
 516                 }
 517
 518                 /* the guy requested a callback when it was OK to write */
 519
 520                 if (pollfd->revents & POLLOUT) {
 521
 522                         pollfd->events &= ~POLLOUT;
 523
 524                         /* external POLL support via protocol 0 */
 525                         this->protocols[0].callback(wsi,
 526                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 527                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 528
 529                         wsi->protocol->callback(wsi,
 530                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 531                                 wsi->user_space,
 532                                 NULL, 0);
 533                 }
 534
 535                 /* any incoming data ready? */
 536
 537                 if (!(pollfd->revents & POLLIN))
 538                         break;
 539
 540 #ifdef LWS_OPENSSL_SUPPORT
 541                 if (wsi->ssl)
 542                         n = SSL_read(wsi->ssl, buf, sizeof buf);
 543                 else
 544 #endif
 545                         n = recv(pollfd->fd, buf, sizeof buf, 0);
 546
 547                 if (n < 0) {
 548                         fprintf(stderr, "Socket read returned %d\n", n);
 549                         break;;
 550                 }
 551                 if (!n) {
 552                         libwebsocket_close_and_free_session(wsi);
 553                         goto nuke_this;
 554                 }
 555
 556                 /* service incoming data */
 557
 558                 n = libwebsocket_read(wsi, buf, n);
 559                 if (n >= 0)
 560                         break;;
 561                 /*
 562                  * it closed and nuked wsi[client], so remove the
 563                  * socket handle and wsi from our service list
 564                  */
 565 nuke_this:
 566
 567                 debug("nuking wsi %p, fsd_count = %d\n",
 568                                 (void *)wsi, this->fds_count - 1);
 569
 570                 delete_from_fd(this, pollfd->fd);
 571
 572                 this->fds_count--;
 573                 for (n = 0; n < this->fds_count; n++)
 574                         if (this->fds[n].fd == pollfd->fd) {
 575                                 while (n < this->fds_count) {
 576                                         this->fds[n] = this->fds[n + 1];
 577                                         n++;
 578                                 }
 579                                 n = this->fds_count;
 580                         }
 581
 582                 /* external POLL support via protocol 0 */
 583                 this->protocols[0].callback(wsi,
 584                         LWS_CALLBACK_DEL_POLL_FD,
 585                         (void *)(long)pollfd->fd, NULL, 0);
 586
 587
 588                 break;
 589         }
 590
 591         return 0;
 592 }
 593
 594
 595 /**
 596  * libwebsocket_context_destroy() - Destroy the websocket context
 597  * @this:       Websocket context
 598  *
 599  *      This function closes any active connections and then frees the
 600  *      context.  After calling this, any further use of the context is
 601  *      undefined.
 602  */
 603 void
 604 libwebsocket_context_destroy(struct libwebsocket_context *this)
 605 {
 606         int n;
 607         int m;
 608         struct libwebsocket *wsi;
 609
 610         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 611
 612                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
 613
 614                         wsi = this->fd_hashtable[n].wsi[m];
 615
 616                         switch (wsi->mode) {
 617                         case LWS_CONNMODE_WS_SERVING:
 618                                 libwebsocket_close_and_free_session(wsi);
 619                                 break;
 620                         case LWS_CONNMODE_WS_CLIENT:
 621                                 libwebsocket_client_close(wsi);
 622                                 break;
 623                         default:
 624                                 break;
 625                         }
 626                 }
 627         }
 628
 629         close(this->fd_random);
 630
 631 #ifdef LWS_OPENSSL_SUPPORT
 632         if (this->ssl_ctx)
 633                 SSL_CTX_free(this->ssl_ctx);
 634         if (this->ssl_client_ctx)
 635                 SSL_CTX_free(this->ssl_client_ctx);
 636 #endif
 637
 638         free(this);
 639 }
 640
 641 /**
 642  * libwebsocket_service() - Service any pending websocket activity
 643  * @this:       Websocket context
 644  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
 645  *              service otherwise block and service immediately, returning
 646  *              after the timeout if nothing needed service.
 647  *
 648  *      This function deals with any pending websocket traffic, for three
 649  *      kinds of event.  It handles these events on both server and client
 650  *      types of connection the same.
 651  *
 652  *      1) Accept new connections to our context's server
 653  *
 654  *      2) Perform pending broadcast writes initiated from other forked
 655  *         processes (effectively serializing asynchronous broadcasts)
 656  *
 657  *      3) Call the receive callback for incoming frame data received by
 658  *          server or client connections.
 659  *
 660  *      You need to call this service function periodically to all the above
 661  *      functions to happen; if your application is single-threaded you can
 662  *      just call it in your main event loop.
 663  *
 664  *      Alternatively you can fork a new process that asynchronously handles
 665  *      calling this service in a loop.  In that case you are happy if this
 666  *      call blocks your thread until it needs to take care of something and
 667  *      would call it with a large nonzero timeout.  Your loop then takes no
 668  *      CPU while there is nothing happening.
 669  *
 670  *      If you are calling it in a single-threaded app, you don't want it to
 671  *      wait around blocking other things in your loop from happening, so you
 672  *      would call it with a timeout_ms of 0, so it returns immediately if
 673  *      nothing is pending, or as soon as it services whatever was pending.
 674  */
 675
 676
 677 int
 678 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
 679 {
 680         int n;
 681
 682         /* stay dead once we are dead */
 683
 684         if (this == NULL)
 685                 return 1;
 686
 687         /* wait for something to need service */
 688
 689         n = poll(this->fds, this->fds_count, timeout_ms);
 690         if (n == 0) /* poll timeout */
 691                 return 0;
 692
 693         if (n < 0 || this->fds[0].revents & (POLLERR | POLLHUP)) {
 694                 /*
 695                 fprintf(stderr, "Listen Socket dead\n");
 696                 */
 697                 return 1;
 698         }
 699
 700         /* handle accept on listening socket? */
 701
 702         for (n = 0; n < this->fds_count; n++)
 703                 if (this->fds[n].revents)
 704                         libwebsocket_service_fd(this, &this->fds[n]);
 705
 706         return 0;
 707 }
 708
 709 /**
 710  * libwebsocket_callback_on_writable() - Request a callback when this socket
 711  *                                       becomes able to be written to without
 712  *                                       blocking
 713  * *
 714  * @wsi:        Websocket connection instance to get callback for
 715  */
 716
 717 int
 718 libwebsocket_callback_on_writable(struct libwebsocket *wsi)
 719 {
 720         struct libwebsocket_context *this = wsi->protocol->owning_server;
 721         int n;
 722
 723         for (n = 0; n < this->fds_count; n++)
 724                 if (this->fds[n].fd == wsi->sock) {
 725                         this->fds[n].events |= POLLOUT;
 726                         n = this->fds_count;
 727                 }
 728
 729         /* external POLL support via protocol 0 */
 730         this->protocols[0].callback(wsi,
 731                 LWS_CALLBACK_SET_MODE_POLL_FD,
 732                 (void *)(long)wsi->sock, NULL, POLLOUT);
 733
 734         return 1;
 735 }
 736
 737 /**
 738  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
 739  *                      all connections using the given protocol when it
 740  *                      becomes possible to write to each socket without
 741  *                      blocking in turn.
 742  *
 743  * @protocol:   Protocol whose connections will get callbacks
 744  */
 745
 746 int
 747 libwebsocket_callback_on_writable_all_protocol(
 748                                   const struct libwebsocket_protocols *protocol)
 749 {
 750         struct libwebsocket_context *this = protocol->owning_server;
 751         int n;
 752         int m;
 753         struct libwebsocket *wsi;
 754
 755         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 756
 757                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
 758
 759                         wsi = this->fd_hashtable[n].wsi[m];
 760
 761                         if (wsi->protocol == protocol)
 762                                 libwebsocket_callback_on_writable(wsi);
 763                 }
 764         }
 765
 766         return 0;
 767 }
 768
 769
 770 /**
 771  * libwebsocket_get_socket_fd() - returns the socket file descriptor
 772  *
 773  * You will not need this unless you are doing something special
 774  *
 775  * @wsi:        Websocket connection instance
 776  */
 777
 778 int
 779 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
 780 {
 781         return wsi->sock;
 782 }
 783
 784 /**
 785  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
 786  *                              receieved packets.
 787  *
 788  * If the output side of a server process becomes choked, this allows flow
 789  * control for the input side.
 790  *
 791  * @wsi:        Websocket connection instance to get callback for
 792  * @enable:     0 = disable read servicing for this connection, 1 = enable
 793  */
 794
 795 int
 796 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
 797 {
 798         struct libwebsocket_context *this = wsi->protocol->owning_server;
 799         int n;
 800
 801         for (n = 0; n < this->fds_count; n++)
 802                 if (this->fds[n].fd == wsi->sock) {
 803                         if (enable)
 804                                 this->fds[n].events |= POLLIN;
 805                         else
 806                                 this->fds[n].events &= ~POLLIN;
 807
 808                         return 0;
 809                 }
 810
 811         if (enable)
 812                 /* external POLL support via protocol 0 */
 813                 this->protocols[0].callback(wsi,
 814                         LWS_CALLBACK_SET_MODE_POLL_FD,
 815                         (void *)(long)wsi->sock, NULL, POLLIN);
 816         else
 817                 /* external POLL support via protocol 0 */
 818                 this->protocols[0].callback(wsi,
 819                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 820                         (void *)(long)wsi->sock, NULL, POLLIN);
 821
 822
 823         fprintf(stderr, "libwebsocket_callback_on_writable "
 824                                                      "unable to find socket\n");
 825         return 1;
 826 }
 827
 828 /**
 829  * libwebsocket_canonical_hostname() - returns this host's hostname
 830  *
 831  * This is typically used by client code to fill in the host parameter
 832  * when making a client connection.  You can only call it after the context
 833  * has been created.
 834  *
 835  * @this:       Websocket context
 836  */
 837
 838
 839 extern const char *
 840 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
 841 {
 842         return (const char *)this->canonical_hostname;
 843 }
 844
 845
 846 static void sigpipe_handler(int x)
 847 {
 848 }
 849
 850
 851
 852 /**
 853  * libwebsocket_create_context() - Create the websocket handler
 854  * @port:       Port to listen on... you can use 0 to suppress listening on
 855  *              any port, that's what you want if you are not running a
 856  *              websocket server at all but just using it as a client
 857  * @protocols:  Array of structures listing supported protocols and a protocol-
 858  *              specific callback for each one.  The list is ended with an
 859  *              entry that has a NULL callback pointer.
 860  *              It's not const because we write the owning_server member
 861  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
 862  *                      to listen using SSL, set to the filepath to fetch the
 863  *                      server cert from, otherwise NULL for unencrypted
 864  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
 865  *                      else ignored
 866  * @gid:        group id to change to after setting listen socket, or -1.
 867  * @uid:        user id to change to after setting listen socket, or -1.
 868  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
 869  *
 870  *      This function creates the listening socket and takes care
 871  *      of all initialization in one step.
 872  *
 873  *      After initialization, it returns a struct libwebsocket_context * that
 874  *      represents this server.  After calling, user code needs to take care
 875  *      of calling libwebsocket_service() with the context pointer to get the
 876  *      server's sockets serviced.  This can be done in the same process context
 877  *      or a forked process, or another thread,
 878  *
 879  *      The protocol callback functions are called for a handful of events
 880  *      including http requests coming in, websocket connections becoming
 881  *      established, and data arriving; it's also called periodically to allow
 882  *      async transmission.
 883  *
 884  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
 885  *      at that time websocket protocol has not been negotiated.  Other
 886  *      protocols after the first one never see any HTTP callack activity.
 887  *
 888  *      The server created is a simple http server by default; part of the
 889  *      websocket standard is upgrading this http connection to a websocket one.
 890  *
 891  *      This allows the same server to provide files like scripts and favicon /
 892  *      images or whatever over http and dynamic data over websockets all in
 893  *      one place; they're all handled in the user callback.
 894  */
 895
 896 struct libwebsocket_context *
 897 libwebsocket_create_context(int port,
 898                                struct libwebsocket_protocols *protocols,
 899                                const char *ssl_cert_filepath,
 900                                const char *ssl_private_key_filepath,
 901                                int gid, int uid, unsigned int options)
 902 {
 903         int n;
 904         int sockfd = 0;
 905         int fd;
 906         struct sockaddr_in serv_addr, cli_addr;
 907         int opt = 1;
 908         struct libwebsocket_context *this = NULL;
 909         unsigned int slen;
 910         char *p;
 911         char hostname[1024];
 912         struct hostent *he;
 913         struct libwebsocket *wsi;
 914
 915 #ifdef LWS_OPENSSL_SUPPORT
 916         SSL_METHOD *method;
 917         char ssl_err_buf[512];
 918 #endif
 919
 920         this = malloc(sizeof(struct libwebsocket_context));
 921         if (!this) {
 922                 fprintf(stderr, "No memory for websocket context\n");
 923                 return NULL;
 924         }
 925         this->protocols = protocols;
 926         this->listen_port = port;
 927         this->http_proxy_port = 0;
 928         this->http_proxy_address[0] = '\0';
 929         this->options = options;
 930         this->fds_count = 0;
 931
 932         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
 933         if (this->fd_random < 0) {
 934                 fprintf(stderr, "Unable to open random device %s %d\n",
 935                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
 936                 return NULL;
 937         }
 938
 939         /* find canonical hostname */
 940
 941         hostname[(sizeof hostname) - 1] = '\0';
 942         gethostname(hostname, (sizeof hostname) - 1);
 943         he = gethostbyname(hostname);
 944         strncpy(this->canonical_hostname, he->h_name,
 945                                            sizeof this->canonical_hostname - 1);
 946         this->canonical_hostname[sizeof this->canonical_hostname - 1] = '\0';
 947         fprintf(stderr, "  canonical hostname = '%s'\n",
 948                                         this->canonical_hostname);
 949
 950         /* split the proxy ads:port if given */
 951
 952         p = getenv("http_proxy");
 953         if (p) {
 954                 strncpy(this->http_proxy_address, p,
 955                                            sizeof this->http_proxy_address - 1);
 956                 this->http_proxy_address[
 957                                     sizeof this->http_proxy_address - 1] = '\0';
 958
 959                 p = strchr(this->http_proxy_address, ':');
 960                 if (p == NULL) {
 961                         fprintf(stderr, "http_proxy needs to be ads:port\n");
 962                         return NULL;
 963                 }
 964                 *p = '\0';
 965                 this->http_proxy_port = atoi(p + 1);
 966
 967                 fprintf(stderr, "Using proxy %s:%u\n",
 968                                 this->http_proxy_address,
 969                                                         this->http_proxy_port);
 970         }
 971
 972         if (port) {
 973
 974 #ifdef LWS_OPENSSL_SUPPORT
 975                 this->use_ssl = ssl_cert_filepath != NULL &&
 976                                                ssl_private_key_filepath != NULL;
 977                 if (this->use_ssl)
 978                         fprintf(stderr, " Compiled with SSL support, "
 979                                                                   "using it\n");
 980                 else
 981                         fprintf(stderr, " Compiled with SSL support, "
 982                                                               "not using it\n");
 983
 984 #else
 985                 if (ssl_cert_filepath != NULL &&
 986                                              ssl_private_key_filepath != NULL) {
 987                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
 988                         return NULL;
 989                 }
 990                 fprintf(stderr, " Compiled without SSL support, "
 991                                                        "serving unencrypted\n");
 992 #endif
 993         }
 994
 995         /* ignore SIGPIPE */
 996
 997         signal(SIGPIPE, sigpipe_handler);
 998
 999
1000 #ifdef LWS_OPENSSL_SUPPORT
1001
1002         /* basic openssl init */
1003
1004         SSL_library_init();
1005
1006         OpenSSL_add_all_algorithms();
1007         SSL_load_error_strings();
1008
1009         /*
1010          * Firefox insists on SSLv23 not SSLv3
1011          * Konq disables SSLv2 by default now, SSLv23 works
1012          */
1013
1014         method = (SSL_METHOD *)SSLv23_server_method();
1015         if (!method) {
1016                 fprintf(stderr, "problem creating ssl method: %s\n",
1017                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1018                 return NULL;
1019         }
1020         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
1021         if (!this->ssl_ctx) {
1022                 fprintf(stderr, "problem creating ssl context: %s\n",
1023                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1024                 return NULL;
1025         }
1026
1027         /* client context */
1028
1029         method = (SSL_METHOD *)SSLv23_client_method();
1030         if (!method) {
1031                 fprintf(stderr, "problem creating ssl method: %s\n",
1032                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1033                 return NULL;
1034         }
1035         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
1036         if (!this->ssl_client_ctx) {
1037                 fprintf(stderr, "problem creating ssl context: %s\n",
1038                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1039                 return NULL;
1040         }
1041
1042
1043         /* openssl init for cert verification (used with client sockets) */
1044
1045         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
1046                                                     LWS_OPENSSL_CLIENT_CERTS)) {
1047                 fprintf(stderr, "Unable to load SSL Client certs from %s "
1048                         "(set by --with-client-cert-dir= in configure) -- "
1049                         " client ssl isn't going to work",
1050                                                       LWS_OPENSSL_CLIENT_CERTS);
1051         }
1052
1053         if (this->use_ssl) {
1054
1055                 /* openssl init for server sockets */
1056
1057                 /* set the local certificate from CertFile */
1058                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
1059                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
1060                 if (n != 1) {
1061                         fprintf(stderr, "problem getting cert '%s': %s\n",
1062                                 ssl_cert_filepath,
1063                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1064                         return NULL;
1065                 }
1066                 /* set the private key from KeyFile */
1067                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
1068                                                 ssl_private_key_filepath,
1069                                                        SSL_FILETYPE_PEM) != 1) {
1070                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
1071                                                 ssl_private_key_filepath,
1072                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1073                         return NULL;
1074                 }
1075                 /* verify private key */
1076                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
1077                         fprintf(stderr, "Private SSL key doesn't match cert\n");
1078                         return NULL;
1079                 }
1080
1081                 /* SSL is happy and has a cert it's content with */
1082         }
1083 #endif
1084
1085         /* selftest */
1086
1087         if (lws_b64_selftest())
1088                 return NULL;
1089
1090         /* fd hashtable init */
1091
1092         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1093                 this->fd_hashtable[n].length = 0;
1094
1095         /* set up our external listening socket we serve on */
1096
1097         if (port) {
1098
1099                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1100                 if (sockfd < 0) {
1101                         fprintf(stderr, "ERROR opening socket");
1102                         return NULL;
1103                 }
1104
1105                 /* allow us to restart even if old sockets in TIME_WAIT */
1106                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1107
1108                 bzero((char *) &serv_addr, sizeof(serv_addr));
1109                 serv_addr.sin_family = AF_INET;
1110                 serv_addr.sin_addr.s_addr = INADDR_ANY;
1111                 serv_addr.sin_port = htons(port);
1112
1113                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
1114                                                              sizeof(serv_addr));
1115                 if (n < 0) {
1116                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1117                                                                 port, n, errno);
1118                         return NULL;
1119                 }
1120
1121                 wsi = malloc(sizeof(struct libwebsocket));
1122                 memset(wsi, 0, sizeof (struct libwebsocket));
1123                 wsi->sock = sockfd;
1124                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
1125                 insert_wsi(this, wsi);
1126
1127                 listen(sockfd, 5);
1128                 fprintf(stderr, " Listening on port %d\n", port);
1129
1130                 /* list in the internal poll array */
1131
1132                 this->fds[this->fds_count].fd = sockfd;
1133                 this->fds[this->fds_count++].events = POLLIN;
1134
1135                 /* external POLL support via protocol 0 */
1136                 this->protocols[0].callback(wsi,
1137                         LWS_CALLBACK_ADD_POLL_FD,
1138                         (void *)(long)sockfd, NULL, POLLIN);
1139
1140         }
1141
1142         /* drop any root privs for this process */
1143
1144         if (gid != -1)
1145                 if (setgid(gid))
1146                         fprintf(stderr, "setgid: %s\n", strerror(errno));
1147         if (uid != -1)
1148                 if (setuid(uid))
1149                         fprintf(stderr, "setuid: %s\n", strerror(errno));
1150
1151
1152         /* set up our internal broadcast trigger sockets per-protocol */
1153
1154         for (this->count_protocols = 0;
1155                         protocols[this->count_protocols].callback;
1156                                                       this->count_protocols++) {
1157                 protocols[this->count_protocols].owning_server = this;
1158                 protocols[this->count_protocols].protocol_index =
1159                                                           this->count_protocols;
1160
1161                 fd = socket(AF_INET, SOCK_STREAM, 0);
1162                 if (fd < 0) {
1163                         fprintf(stderr, "ERROR opening socket");
1164                         return NULL;
1165                 }
1166
1167                 /* allow us to restart even if old sockets in TIME_WAIT */
1168                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1169
1170                 bzero((char *) &serv_addr, sizeof(serv_addr));
1171                 serv_addr.sin_family = AF_INET;
1172                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1173                 serv_addr.sin_port = 0; /* pick the port for us */
1174
1175                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
1176                 if (n < 0) {
1177                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1178                                                                 port, n, errno);
1179                         return NULL;
1180                 }
1181
1182                 slen = sizeof cli_addr;
1183                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
1184                 if (n < 0) {
1185                         fprintf(stderr, "getsockname failed\n");
1186                         return NULL;
1187                 }
1188                 protocols[this->count_protocols].broadcast_socket_port =
1189                                                        ntohs(cli_addr.sin_port);
1190                 listen(fd, 5);
1191
1192                 debug("  Protocol %s broadcast socket %d\n",
1193                                 protocols[this->count_protocols].name,
1194                                                       ntohs(cli_addr.sin_port));
1195
1196                 /* dummy wsi per broadcast proxy socket */
1197
1198                 wsi = malloc(sizeof(struct libwebsocket));
1199                 memset(wsi, 0, sizeof (struct libwebsocket));
1200                 wsi->sock = fd;
1201                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
1202                 /* note which protocol we are proxying */
1203                 wsi->protocol_index_for_broadcast_proxy = this->count_protocols;
1204                 insert_wsi(this, wsi);
1205
1206                 /* list in internal poll array */
1207
1208                 this->fds[this->fds_count].fd = fd;
1209                 this->fds[this->fds_count].events = POLLIN;
1210                 this->fds[this->fds_count].revents = 0;
1211                 this->fds_count++;
1212
1213                 /* external POLL support via protocol 0 */
1214                 this->protocols[0].callback(wsi,
1215                         LWS_CALLBACK_ADD_POLL_FD,
1216                         (void *)(long)fd, NULL, POLLIN);
1217         }
1218
1219         return this;
1220 }
1221
1222
1223 #ifndef LWS_NO_FORK
1224
1225 /**
1226  * libwebsockets_fork_service_loop() - Optional helper function forks off
1227  *                                a process for the websocket server loop.
1228  *                              You don't have to use this but if not, you
1229  *                              have to make sure you are calling
1230  *                              libwebsocket_service periodically to service
1231  *                              the websocket traffic
1232  * @this:       server context returned by creation function
1233  */
1234
1235 int
1236 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
1237 {
1238         int fd;
1239         struct sockaddr_in cli_addr;
1240         int n;
1241         int p;
1242
1243         n = fork();
1244         if (n < 0)
1245                 return n;
1246
1247         if (!n) {
1248
1249                 /* main process context */
1250
1251                 /*
1252                  * set up the proxy sockets to allow broadcast from
1253                  * service process context
1254                  */
1255
1256                 for (p = 0; p < this->count_protocols; p++) {
1257                         fd = socket(AF_INET, SOCK_STREAM, 0);
1258                         if (fd < 0) {
1259                                 fprintf(stderr, "Unable to create socket\n");
1260                                 return -1;
1261                         }
1262                         cli_addr.sin_family = AF_INET;
1263                         cli_addr.sin_port = htons(
1264                              this->protocols[p].broadcast_socket_port);
1265                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1266                         n = connect(fd, (struct sockaddr *)&cli_addr,
1267                                                                sizeof cli_addr);
1268                         if (n < 0) {
1269                                 fprintf(stderr, "Unable to connect to "
1270                                                 "broadcast socket %d, %s\n",
1271                                                 n, strerror(errno));
1272                                 return -1;
1273                         }
1274
1275                         this->protocols[p].broadcast_socket_user_fd = fd;
1276                 }
1277
1278                 return 0;
1279         }
1280
1281         /* we want a SIGHUP when our parent goes down */
1282         prctl(PR_SET_PDEATHSIG, SIGHUP);
1283
1284         /* in this forked process, sit and service websocket connections */
1285
1286         while (1)
1287                 if (libwebsocket_service(this, 1000))
1288                         return -1;
1289
1290         return 0;
1291 }
1292
1293 #endif
1294
1295 /**
1296  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1297  *                                connection.
1298  * @wsi:        pointer to struct websocket you want to know the protocol of
1299  *
1300  *
1301  *      This is useful to get the protocol to broadcast back to from inside
1302  * the callback.
1303  */
1304
1305 const struct libwebsocket_protocols *
1306 libwebsockets_get_protocol(struct libwebsocket *wsi)
1307 {
1308         return wsi->protocol;
1309 }
1310
1311 /**
1312  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1313  *                                connections of the given protocol.
1314  * @protocol:   pointer to the protocol you will broadcast to all members of
1315  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1316  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1317  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1318  *              case you are calling this function from callback context.
1319  * @len:        length of payload data in buf, starting from buf.
1320  *
1321  *      This function allows bulk sending of a packet to every connection using
1322  * the given protocol.  It does not send the data directly; instead it calls
1323  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1324  * wants to actually send the data for that connection, the callback itself
1325  * should call libwebsocket_write().
1326  *
1327  * libwebsockets_broadcast() can be called from another fork context without
1328  * having to take any care about data visibility between the processes, it'll
1329  * "just work".
1330  */
1331
1332
1333 int
1334 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1335                                                  unsigned char *buf, size_t len)
1336 {
1337         struct libwebsocket_context *this = protocol->owning_server;
1338         int n;
1339         int m;
1340         struct libwebsocket * wsi;
1341
1342         if (!protocol->broadcast_socket_user_fd) {
1343                 /*
1344                  * We are either running unforked / flat, or we are being
1345                  * called from poll thread context
1346                  * eg, from a callback.  In that case don't use sockets for
1347                  * broadcast IPC (since we can't open a socket connection to
1348                  * a socket listening on our own thread) but directly do the
1349                  * send action.
1350                  *
1351                  * Locking is not needed because we are by definition being
1352                  * called in the poll thread context and are serialized.
1353                  */
1354
1355                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1356
1357                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
1358
1359                                 wsi = this->fd_hashtable[n].wsi[m];
1360
1361                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
1362                                         continue;
1363
1364                                 /*
1365                                  * never broadcast to
1366                                  * non-established connections
1367                                  */
1368                                 if (wsi->state != WSI_STATE_ESTABLISHED)
1369                                         continue;
1370
1371                                 /* only broadcast to guys using
1372                                  * requested protocol
1373                                  */
1374                                 if (wsi->protocol != protocol)
1375                                         continue;
1376
1377                                 wsi->protocol->callback(wsi,
1378                                          LWS_CALLBACK_BROADCAST,
1379                                          wsi->user_space,
1380                                          buf, len);
1381                         }
1382                 }
1383
1384                 return 0;
1385         }
1386
1387         /*
1388          * We're being called from a different process context than the server
1389          * loop.  Instead of broadcasting directly, we send our
1390          * payload on a socket to do the IPC; the server process will serialize
1391          * the broadcast action in its main poll() loop.
1392          *
1393          * There's one broadcast socket listening for each protocol supported
1394          * set up when the websocket server initializes
1395          */
1396
1397         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
1398
1399         return n;
1400 }