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)
 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         /*
 173          * signal we are closing, libsocket_write will
 174          * add any necessary version-specific stuff.  If the write fails,
 175          * no worries we are closing anyway.  If we didn't initiate this
 176          * close, then our state has been changed to
 177          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this
 178          */
 179
 180         if (old_state == WSI_STATE_ESTABLISHED)
 181                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
 182                                                                LWS_WRITE_CLOSE);
 183
 184         wsi->state = WSI_STATE_DEAD_SOCKET;
 185
 186         /* tell the user it's all over for this guy */
 187
 188         if (wsi->protocol->callback && old_state == WSI_STATE_ESTABLISHED)
 189                 wsi->protocol->callback(this, wsi, LWS_CALLBACK_CLOSED,
 190                                                       wsi->user_space, NULL, 0);
 191
 192         /* free up his allocations */
 193
 194         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 195                 if (wsi->utf8_token[n].token)
 196                         free(wsi->utf8_token[n].token);
 197
 198 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 199
 200 #ifdef LWS_OPENSSL_SUPPORT
 201         if (wsi->ssl) {
 202                 n = SSL_get_fd(wsi->ssl);
 203                 SSL_shutdown(wsi->ssl);
 204                 close(n);
 205                 SSL_free(wsi->ssl);
 206         } else {
 207 #endif
 208                 shutdown(wsi->sock, SHUT_RDWR);
 209                 close(wsi->sock);
 210 #ifdef LWS_OPENSSL_SUPPORT
 211         }
 212 #endif
 213         if (wsi->user_space)
 214                 free(wsi->user_space);
 215
 216         free(wsi);
 217 }
 218
 219 /**
 220  * libwebsockets_hangup_on_client() - Server calls to terminate client
 221  *                                      connection
 222  * @this:       libwebsockets context
 223  * @fd:         Connection socket descriptor
 224  */
 225
 226 void
 227 libwebsockets_hangup_on_client(struct libwebsocket_context *this, int fd)
 228 {
 229         struct libwebsocket *wsi = wsi_from_fd(this, fd);
 230         int n;
 231
 232         if (wsi == NULL)
 233                 return;
 234
 235         delete_from_fd(this, fd);
 236
 237         for (n = 0; n < this->fds_count - 1; n++)
 238                 if (this->fds[n].fd == fd) {
 239                         while (n < this->fds_count - 1) {
 240                                 this->fds[n] = this->fds[n + 1];
 241                                 n++;
 242                         }
 243                         n = this->fds_count;
 244                         this->fds_count--;
 245                 }
 246
 247         libwebsocket_close_and_free_session(this, wsi);
 248 }
 249
 250
 251 /**
 252  * libwebsockets_get_peer_addresses() - Get client address information
 253  * @fd:         Connection socket descriptor
 254  * @name:       Buffer to take client address name
 255  * @name_len:   Length of client address name buffer
 256  * @rip:        Buffer to take client address IP qotted quad
 257  * @rip_len:    Length of client address IP buffer
 258  *
 259  *      This function fills in @name and @rip with the name and IP of
 260  *      the client connected with socket descriptor @fd.  Names may be
 261  *      truncated if there is not enough room.  If either cannot be
 262  *      determined, they will be returned as valid zero-length strings.
 263  */
 264
 265 void
 266 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 267                                         char *rip, int rip_len)
 268 {
 269         unsigned int len;
 270         struct sockaddr_in sin;
 271         struct hostent *host;
 272         struct hostent *host1;
 273         char ip[128];
 274         char *p;
 275         int n;
 276
 277         rip[0] = '\0';
 278         name[0] = '\0';
 279
 280         len = sizeof sin;
 281         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 282                 perror("getpeername");
 283                 return;
 284         }
 285
 286         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 287                                                                        AF_INET);
 288         if (host == NULL) {
 289                 perror("gethostbyaddr");
 290                 return;
 291         }
 292
 293         strncpy(name, host->h_name, name_len);
 294         name[name_len - 1] = '\0';
 295
 296         host1 = gethostbyname(host->h_name);
 297         if (host1 == NULL)
 298                 return;
 299         p = (char *)host1;
 300         n = 0;
 301         while (p != NULL) {
 302                 p = host1->h_addr_list[n++];
 303                 if (p == NULL)
 304                         continue;
 305                 if (host1->h_addrtype != AF_INET)
 306                         continue;
 307
 308                 sprintf(ip, "%d.%d.%d.%d",
 309                                 p[0], p[1], p[2], p[3]);
 310                 p = NULL;
 311                 strncpy(rip, ip, rip_len);
 312                 rip[rip_len - 1] = '\0';
 313         }
 314 }
 315
 316 /**
 317  * libwebsocket_service_fd() - Service polled socket with something waiting
 318  * @this:       Websocket context
 319  * @pollfd:     The pollfd entry describing the socket fd and which events
 320  *              happened.
 321  *
 322  *      This function closes any active connections and then frees the
 323  *      context.  After calling this, any further use of the context is
 324  *      undefined.
 325  */
 326
 327 int
 328 libwebsocket_service_fd(struct libwebsocket_context *this,
 329                                                           struct pollfd *pollfd)
 330 {
 331         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
 332                                                   LWS_SEND_BUFFER_POST_PADDING];
 333         struct libwebsocket *wsi;
 334         struct libwebsocket *new_wsi;
 335         int n;
 336         int m;
 337         size_t len;
 338         int accept_fd;
 339         unsigned int clilen;
 340         struct sockaddr_in cli_addr;
 341         struct timeval tv;
 342         static const char magic_websocket_guid[] =
 343                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 344         static const char magic_websocket_04_masking_guid[] =
 345                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 346         char hash[20];
 347         char pkt[1024];
 348         char *p = &pkt[0];
 349         const char *pc;
 350         int okay = 0;
 351 #ifdef LWS_OPENSSL_SUPPORT
 352         char ssl_err_buf[512];
 353 #endif
 354         /*
 355          * you can call us with pollfd = NULL to just allow the once-per-second
 356          * global timeout checks; if less than a second since the last check
 357          * it returns immediately then.
 358          */
 359
 360         gettimeofday(&tv, NULL);
 361
 362         if (this->last_timeout_check_s != tv.tv_sec) {
 363                 this->last_timeout_check_s = tv.tv_sec;
 364
 365                 /* global timeout check once per second */
 366
 367                 for (n = 0; n < this->fds_count; n++) {
 368                         wsi = wsi_from_fd(this, this->fds[n].fd);
 369                         if (!wsi->pending_timeout)
 370                                 continue;
 371
 372                         /*
 373                          * if we went beyond the allowed time, kill the
 374                          * connection
 375                          */
 376
 377                         if (tv.tv_sec > wsi->pending_timeout_limit)
 378                                 libwebsocket_close_and_free_session(this, wsi);
 379                 }
 380         }
 381
 382         /* just here for timeout management? */
 383
 384         if (pollfd == NULL)
 385                 return 0;
 386
 387         /* no, here to service a socket descriptor */
 388
 389         wsi = wsi_from_fd(this, pollfd->fd);
 390
 391         if (wsi == NULL)
 392                 return 1;
 393
 394         switch (wsi->mode) {
 395         case LWS_CONNMODE_SERVER_LISTENER:
 396
 397                 /* pollin means a client has connected to us then */
 398
 399                 if (!pollfd->revents & POLLIN)
 400                         break;
 401
 402                 /* listen socket got an unencrypted connection... */
 403
 404                 clilen = sizeof(cli_addr);
 405                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 406                                                                        &clilen);
 407                 if (accept_fd < 0) {
 408                         fprintf(stderr, "ERROR on accept");
 409                         break;
 410                 }
 411
 412                 if (this->fds_count >= MAX_CLIENTS) {
 413                         fprintf(stderr, "too busy to accept new client\n");
 414                         close(accept_fd);
 415                         break;
 416                 }
 417
 418                 /*
 419                  * look at who we connected to and give user code a chance
 420                  * to reject based on client IP.  There's no protocol selected
 421                  * yet so we issue this to protocols[0]
 422                  */
 423
 424                 if ((this->protocols[0].callback)(this, wsi,
 425                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 426                                              (void*)(long)accept_fd, NULL, 0)) {
 427                         fprintf(stderr, "Callback denied network connection\n");
 428                         close(accept_fd);
 429                         break;
 430                 }
 431
 432                 /* accepting connection to main listener */
 433
 434                 new_wsi = malloc(sizeof(struct libwebsocket));
 435                 if (new_wsi == NULL) {
 436                         fprintf(stderr, "Out of memory for new connection\n");
 437                         break;
 438                 }
 439
 440                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 441                 new_wsi->sock = accept_fd;
 442                 new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
 443
 444 #ifdef LWS_OPENSSL_SUPPORT
 445                 new_wsi->ssl = NULL;
 446
 447                 if (this->use_ssl) {
 448
 449                         new_wsi->ssl = SSL_new(this->ssl_ctx);
 450                         if (new_wsi->ssl == NULL) {
 451                                 fprintf(stderr, "SSL_new failed: %s\n",
 452                                     ERR_error_string(SSL_get_error(
 453                                     new_wsi->ssl, 0), NULL));
 454                                     libwebsockets_decode_ssl_error();
 455                                 free(new_wsi);
 456                                 break;
 457                         }
 458
 459                         SSL_set_fd(new_wsi->ssl, accept_fd);
 460
 461                         n = SSL_accept(new_wsi->ssl);
 462                         if (n != 1) {
 463                                 /*
 464                                  * browsers seem to probe with various
 465                                  * ssl params which fail then retry
 466                                  * and succeed
 467                                  */
 468                                 debug("SSL_accept failed skt %u: %s\n",
 469                                       pollfd->fd,
 470                                       ERR_error_string(SSL_get_error(
 471                                       new_wsi->ssl, n), NULL));
 472                                 SSL_free(
 473                                        new_wsi->ssl);
 474                                 free(new_wsi);
 475                                 break;
 476                         }
 477
 478                         debug("accepted new SSL conn  "
 479                               "port %u on fd=%d SSL ver %s\n",
 480                                 ntohs(cli_addr.sin_port), accept_fd,
 481                                   SSL_get_version(new_wsi->ssl));
 482
 483                 } else
 484 #endif
 485                         debug("accepted new conn  port %u on fd=%d\n",
 486                                           ntohs(cli_addr.sin_port), accept_fd);
 487
 488                 /* intialize the instance struct */
 489
 490                 new_wsi->state = WSI_STATE_HTTP;
 491                 new_wsi->name_buffer_pos = 0;
 492                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 493
 494                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 495                         new_wsi->utf8_token[n].token = NULL;
 496                         new_wsi->utf8_token[n].token_len = 0;
 497                 }
 498
 499                 /*
 500                  * these can only be set once the protocol is known
 501                  * we set an unestablished connection's protocol pointer
 502                  * to the start of the supported list, so it can look
 503                  * for matching ones during the handshake
 504                  */
 505                 new_wsi->protocol = this->protocols;
 506                 new_wsi->user_space = NULL;
 507
 508                 /*
 509                  * Default protocol is 76 / 00
 510                  * After 76, there's a header specified to inform which
 511                  * draft the client wants, when that's seen we modify
 512                  * the individual connection's spec revision accordingly
 513                  */
 514                 new_wsi->ietf_spec_revision = 0;
 515
 516                 insert_wsi(this, new_wsi);
 517
 518                 /*
 519                  * make sure NO events are seen yet on this new socket
 520                  * (otherwise we inherit old fds[client].revents from
 521                  * previous socket there and die mysteriously! )
 522                  */
 523                 this->fds[this->fds_count].revents = 0;
 524
 525                 this->fds[this->fds_count].events = POLLIN;
 526                 this->fds[this->fds_count++].fd = accept_fd;
 527
 528                 /* external POLL support via protocol 0 */
 529                 this->protocols[0].callback(this, new_wsi,
 530                         LWS_CALLBACK_ADD_POLL_FD,
 531                         (void *)(long)accept_fd, NULL, POLLIN);
 532
 533                 break;
 534
 535         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 536
 537                 /* as we are listening, POLLIN means accept() is needed */
 538
 539                 if (!pollfd->revents & POLLIN)
 540                         break;
 541
 542                 /* listen socket got an unencrypted connection... */
 543
 544                 clilen = sizeof(cli_addr);
 545                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 546                                                                        &clilen);
 547                 if (accept_fd < 0) {
 548                         fprintf(stderr, "ERROR on accept");
 549                         break;
 550                 }
 551
 552                 if (this->fds_count >= MAX_CLIENTS) {
 553                         fprintf(stderr, "too busy to accept new broadcast "
 554                                                               "proxy client\n");
 555                         close(accept_fd);
 556                         break;
 557                 }
 558
 559                 /* create a dummy wsi for the connection and add it */
 560
 561                 new_wsi = malloc(sizeof(struct libwebsocket));
 562                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 563                 new_wsi->sock = accept_fd;
 564                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 565                 new_wsi->state = WSI_STATE_ESTABLISHED;
 566                 /* note which protocol we are proxying */
 567                 new_wsi->protocol_index_for_broadcast_proxy =
 568                                         wsi->protocol_index_for_broadcast_proxy;
 569                 insert_wsi(this, new_wsi);
 570
 571                 /* add connected socket to internal poll array */
 572
 573                 this->fds[this->fds_count].revents = 0;
 574                 this->fds[this->fds_count].events = POLLIN;
 575                 this->fds[this->fds_count++].fd = accept_fd;
 576
 577                 /* external POLL support via protocol 0 */
 578                 this->protocols[0].callback(this, new_wsi,
 579                         LWS_CALLBACK_ADD_POLL_FD,
 580                         (void *)(long)accept_fd, NULL, POLLIN);
 581
 582                 break;
 583
 584         case LWS_CONNMODE_BROADCAST_PROXY:
 585
 586                 /* handle session socket closed */
 587
 588                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 589
 590                         debug("Session Socket %p (fd=%d) dead\n",
 591                                 (void *)wsi, pollfd->fd);
 592
 593                         libwebsocket_close_and_free_session(this, wsi);
 594                         return 1;
 595                 }
 596
 597                 /* the guy requested a callback when it was OK to write */
 598
 599                 if (pollfd->revents & POLLOUT) {
 600
 601                         /* one shot */
 602
 603                         pollfd->events &= ~POLLOUT;
 604
 605                         /* external POLL support via protocol 0 */
 606                         this->protocols[0].callback(this, wsi,
 607                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 608                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 609
 610                         wsi->protocol->callback(this, wsi,
 611                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 612                                 wsi->user_space,
 613                                 NULL, 0);
 614                 }
 615
 616                 /* any incoming data ready? */
 617
 618                 if (!(pollfd->revents & POLLIN))
 619                         break;
 620
 621                 /* get the issued broadcast payload from the socket */
 622
 623                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 624                                                          MAX_BROADCAST_PAYLOAD);
 625                 if (len < 0) {
 626                         fprintf(stderr, "Error reading broadcast payload\n");
 627                         break;
 628                 }
 629
 630                 /* broadcast it to all guys with this protocol index */
 631
 632                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 633
 634                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
 635
 636                                 new_wsi = this->fd_hashtable[n].wsi[m];
 637
 638                                 /* only to clients we are serving to */
 639
 640                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 641                                         continue;
 642
 643                                 /*
 644                                  * never broadcast to non-established
 645                                  * connection
 646                                  */
 647
 648                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 649                                         continue;
 650
 651                                 /*
 652                                  * only broadcast to connections using
 653                                  * the requested protocol
 654                                  */
 655
 656                                 if (new_wsi->protocol->protocol_index !=
 657                                         wsi->protocol_index_for_broadcast_proxy)
 658                                         continue;
 659
 660                                 /* broadcast it to this connection */
 661
 662                                 new_wsi->protocol->callback(this, new_wsi,
 663                                         LWS_CALLBACK_BROADCAST,
 664                                         new_wsi->user_space,
 665                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 666                         }
 667                 }
 668                 break;
 669
 670         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
 671
 672                 /* handle proxy hung up on us */
 673
 674                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 675
 676                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
 677                                 (void *)wsi, pollfd->fd);
 678
 679                         libwebsocket_close_and_free_session(this, wsi);
 680                         return 1;
 681                 }
 682
 683                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
 684                 if (n < 0) {
 685                         libwebsocket_close_and_free_session(this, wsi);
 686                         fprintf(stderr, "ERROR reading from proxy socket\n");
 687                         return 1;
 688                 }
 689
 690                 pkt[13] = '\0';
 691                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
 692                         libwebsocket_close_and_free_session(this, wsi);
 693                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
 694                         return 1;
 695                 }
 696
 697                 /* clear his proxy connection timeout */
 698
 699                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 700
 701                 /* fallthru */
 702
 703         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
 704
 705         #ifdef LWS_OPENSSL_SUPPORT
 706                 if (wsi->use_ssl) {
 707
 708                         wsi->ssl = SSL_new(this->ssl_client_ctx);
 709                         wsi->client_bio = BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 710                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 711
 712                         SSL_set_ex_data(wsi->ssl,
 713                               this->openssl_websocket_private_data_index, this);
 714
 715                         if (SSL_connect(wsi->ssl) <= 0) {
 716                                 fprintf(stderr, "SSL connect error %s\n",
 717                                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 718                                 libwebsocket_close_and_free_session(this, wsi);
 719                                 return 1;
 720                         }
 721
 722                         n = SSL_get_verify_result(wsi->ssl);
 723                         if (n != X509_V_OK) {
 724                                 if (n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 725                                                             wsi->use_ssl != 2) {
 726
 727                                         fprintf(stderr, "server's cert didn't "
 728                                                                    "look good %d\n", n);
 729                                         libwebsocket_close_and_free_session(this, wsi);
 730                                         return 1;
 731                                 }
 732                         }
 733                 } else {
 734                         wsi->ssl = NULL;
 735         #endif
 736
 737
 738         #ifdef LWS_OPENSSL_SUPPORT
 739                 }
 740         #endif
 741
 742                 /*
 743                  * create the random key
 744                  */
 745
 746                 n = read(this->fd_random, hash, 16);
 747                 if (n != 16) {
 748                         fprintf(stderr, "Unable to read from random dev %s\n",
 749                                                         SYSTEM_RANDOM_FILEPATH);
 750                         free(wsi->c_path);
 751                         free(wsi->c_host);
 752                         if (wsi->c_origin)
 753                                 free(wsi->c_origin);
 754                         if (wsi->c_protocol)
 755                                 free(wsi->c_protocol);
 756                         libwebsocket_close_and_free_session(this, wsi);
 757                         return 1;
 758                 }
 759
 760                 lws_b64_encode_string(hash, 16, wsi->key_b64,
 761                                                            sizeof wsi->key_b64);
 762
 763                 /*
 764                  * 04 example client handshake
 765                  *
 766                  * GET /chat HTTP/1.1
 767                  * Host: server.example.com
 768                  * Upgrade: websocket
 769                  * Connection: Upgrade
 770                  * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 771                  * Sec-WebSocket-Origin: http://example.com
 772                  * Sec-WebSocket-Protocol: chat, superchat
 773                  * Sec-WebSocket-Version: 4
 774                  */
 775
 776                 p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 777                 p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 778                 p += sprintf(p, "Upgrade: websocket\x0d\x0a");
 779                 p += sprintf(p, "Connection: Upgrade\x0d\x0a"
 780                                         "Sec-WebSocket-Key: ");
 781                 strcpy(p, wsi->key_b64);
 782                 p += strlen(wsi->key_b64);
 783                 p += sprintf(p, "\x0d\x0a");
 784                 if (wsi->c_origin)
 785                         p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
 786                                                                  wsi->c_origin);
 787                 if (wsi->c_protocol)
 788                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 789                                                                wsi->c_protocol);
 790                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a",
 791                                                        wsi->ietf_spec_revision);
 792
 793                 /* done with these now */
 794
 795                 free(wsi->c_path);
 796                 free(wsi->c_host);
 797                 if (wsi->c_origin)
 798                         free(wsi->c_origin);
 799
 800                 /* prepare the expected server accept response */
 801
 802                 strcpy((char *)buf, wsi->key_b64);
 803                 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 804
 805                 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 806
 807                 lws_b64_encode_string(hash, 20,
 808                                 wsi->initial_handshake_hash_base64,
 809                                      sizeof wsi->initial_handshake_hash_base64);
 810
 811                 /* send our request to the server */
 812
 813         #ifdef LWS_OPENSSL_SUPPORT
 814                 if (wsi->use_ssl)
 815                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 816                 else
 817         #endif
 818                         n = send(wsi->sock, pkt, p - pkt, 0);
 819
 820                 if (n < 0) {
 821                         fprintf(stderr, "ERROR writing to client socket\n");
 822                         libwebsocket_close_and_free_session(this, wsi);
 823                         return 1;
 824                 }
 825
 826                 wsi->parser_state = WSI_TOKEN_NAME_PART;
 827                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 828                 libwebsocket_set_timeout(wsi,
 829                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, 5);
 830
 831                 break;
 832
 833         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 834
 835                 /* handle server hung up on us */
 836
 837                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 838
 839                         fprintf(stderr, "Server connection %p (fd=%d) dead\n",
 840                                 (void *)wsi, pollfd->fd);
 841
 842                         goto bail3;
 843                 }
 844
 845
 846                 /* interpret the server response */
 847
 848                 /*
 849                  *  HTTP/1.1 101 Switching Protocols
 850                  *  Upgrade: websocket
 851                  *  Connection: Upgrade
 852                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 853                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 854                  *  Sec-WebSocket-Protocol: chat
 855                  */
 856
 857         #ifdef LWS_OPENSSL_SUPPORT
 858                 if (wsi->use_ssl)
 859                         len = SSL_read(wsi->ssl, pkt, sizeof pkt);
 860                 else
 861         #endif
 862                         len = recv(wsi->sock, pkt, sizeof pkt, 0);
 863
 864                 if (len < 0) {
 865                         fprintf(stderr,
 866                                   "libwebsocket_client_handshake read error\n");
 867                         goto bail3;
 868                 }
 869
 870                 p = pkt;
 871                 for (n = 0; n < len; n++)
 872                         libwebsocket_parse(wsi, *p++);
 873
 874                 if (wsi->parser_state != WSI_PARSING_COMPLETE) {
 875                         fprintf(stderr, "libwebsocket_client_handshake "
 876                                         "server response ailed parsing\n");
 877                         goto bail3;
 878                 }
 879
 880                 /*
 881                  * well, what the server sent looked reasonable for syntax.
 882                  * Now let's confirm it sent all the necessary headers
 883                  */
 884
 885                  if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 886                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 887                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 888                         !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 889                         !wsi->utf8_token[WSI_TOKEN_NONCE].token_len ||
 890                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
 891                                                      wsi->c_protocol != NULL)) {
 892                         fprintf(stderr, "libwebsocket_client_handshake "
 893                                                         "missing required header(s)\n");
 894                         pkt[len] = '\0';
 895                         fprintf(stderr, "%s", pkt);
 896                         goto bail3;
 897                 }
 898
 899                 /*
 900                  * Everything seems to be there, now take a closer look at what
 901                  * is in each header
 902                  */
 903
 904                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 905                 if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
 906                                                    "101 switching protocols")) {
 907                         fprintf(stderr, "libwebsocket_client_handshake "
 908                                         "server sent bad HTTP response '%s'\n",
 909                                          wsi->utf8_token[WSI_TOKEN_HTTP].token);
 910                         goto bail3;
 911                 }
 912
 913                 strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 914                 if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 915                                                                  "websocket")) {
 916                         fprintf(stderr, "libwebsocket_client_handshake server "
 917                                         "sent bad Upgrade header '%s'\n",
 918                                       wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 919                         goto bail3;
 920                 }
 921
 922                 strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 923                 if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 924                                                                    "upgrade")) {
 925                         fprintf(stderr, "libwebsocket_client_handshake server "
 926                                         "sent bad Connection hdr '%s'\n",
 927                                    wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 928                         goto bail3;
 929                 }
 930
 931
 932                 pc = wsi->c_protocol;
 933
 934                 /*
 935                  * confirm the protocol the server wants to talk was in the list
 936                  * of protocols we offered
 937                  */
 938
 939                 if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 940
 941                         /*
 942                          * no protocol name to work from,
 943                          * default to first protocol
 944                          */
 945                         wsi->protocol = &this->protocols[0];
 946
 947                         free(wsi->c_protocol);
 948
 949                         goto check_accept;
 950                 }
 951
 952                 while (*pc && !okay) {
 953                         if ((!strncmp(pc,
 954                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 955                            wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 956                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 957                    pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 958                                 okay = 1;
 959                                 continue;
 960                         }
 961                         while (*pc && *pc != ',')
 962                                 pc++;
 963                         while (*pc && *pc != ' ')
 964                                 pc++;
 965                 }
 966
 967                 /* done with him now */
 968
 969                 if (wsi->c_protocol)
 970                         free(wsi->c_protocol);
 971
 972
 973                 if (!okay) {
 974                         fprintf(stderr, "libwebsocket_client_handshake server "
 975                                                 "sent bad protocol '%s'\n",
 976                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 977                         goto bail2;
 978                 }
 979
 980                 /*
 981                  * identify the selected protocol struct and set it
 982                  */
 983                 n = 0;
 984                 wsi->protocol = NULL;
 985                 while (this->protocols[n].callback) {
 986                         if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 987                                                this->protocols[n].name) == 0)
 988                                 wsi->protocol = &this->protocols[n];
 989                         n++;
 990                 }
 991
 992                 if (wsi->protocol == NULL) {
 993                         fprintf(stderr, "libwebsocket_client_handshake server "
 994                                         "requested protocol '%s', which we "
 995                                         "said we supported but we don't!\n",
 996                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 997                         goto bail2;
 998                 }
 999
1000         check_accept:
1001                 /*
1002                  * Confirm his accept token is the one we precomputed
1003                  */
1004
1005                 if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1006                                           wsi->initial_handshake_hash_base64)) {
1007                         fprintf(stderr, "libwebsocket_client_handshake server "
1008                                 "sent bad ACCEPT '%s' vs computed '%s'\n",
1009                                 wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1010                                             wsi->initial_handshake_hash_base64);
1011                         goto bail2;
1012                 }
1013
1014                 /*
1015                  * Calculate the masking key to use when sending data to server
1016                  */
1017
1018                 strcpy((char *)buf, wsi->key_b64);
1019                 p = (char *)buf + strlen(wsi->key_b64);
1020                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1021                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1022                 strcpy(p, magic_websocket_04_masking_guid);
1023                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1024
1025                 /* allocate the per-connection user memory (if any) */
1026
1027                 if (wsi->protocol->per_session_data_size) {
1028                         wsi->user_space = malloc(
1029                                           wsi->protocol->per_session_data_size);
1030                         if (wsi->user_space  == NULL) {
1031                                 fprintf(stderr, "Out of memory for "
1032                                                            "conn user space\n");
1033                                 goto bail2;
1034                         }
1035                 } else
1036                         wsi->user_space = NULL;
1037
1038                 /* clear his proxy connection timeout */
1039
1040                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1041
1042                 /* mark him as being alive */
1043
1044                 wsi->state = WSI_STATE_ESTABLISHED;
1045                 wsi->mode = LWS_CONNMODE_WS_CLIENT;
1046
1047                 fprintf(stderr, "handshake OK for protocol %s\n",
1048                                                            wsi->protocol->name);
1049
1050                 /* call him back to inform him he is up */
1051
1052                 wsi->protocol->callback(this, wsi,
1053                                  LWS_CALLBACK_CLIENT_ESTABLISHED,
1054                                  wsi->user_space,
1055                                  NULL, 0);
1056
1057                 break;
1058
1059 bail3:
1060                 if (wsi->c_protocol)
1061                         free(wsi->c_protocol);
1062
1063 bail2:
1064                 libwebsocket_close_and_free_session(this, wsi);
1065                 return 1;
1066
1067
1068         case LWS_CONNMODE_WS_SERVING:
1069         case LWS_CONNMODE_WS_CLIENT:
1070
1071                 /* handle session socket closed */
1072
1073                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1074
1075                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1076                                 (void *)wsi, pollfd->fd);
1077
1078                         libwebsocket_close_and_free_session(this, wsi);
1079                         return 1;
1080                 }
1081
1082                 /* the guy requested a callback when it was OK to write */
1083
1084                 if (pollfd->revents & POLLOUT) {
1085
1086                         pollfd->events &= ~POLLOUT;
1087
1088                         /* external POLL support via protocol 0 */
1089                         this->protocols[0].callback(this, wsi,
1090                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1091                                 (void *)(long)wsi->sock, NULL, POLLOUT);
1092
1093                         wsi->protocol->callback(this, wsi,
1094                                 LWS_CALLBACK_CLIENT_WRITEABLE,
1095                                 wsi->user_space,
1096                                 NULL, 0);
1097                 }
1098
1099                 /* any incoming data ready? */
1100
1101                 if (!(pollfd->revents & POLLIN))
1102                         break;
1103
1104 #ifdef LWS_OPENSSL_SUPPORT
1105                 if (wsi->ssl)
1106                         n = SSL_read(wsi->ssl, buf, sizeof buf);
1107                 else
1108 #endif
1109                         n = recv(pollfd->fd, buf, sizeof buf, 0);
1110
1111                 if (n < 0) {
1112                         fprintf(stderr, "Socket read returned %d\n", n);
1113                         break;
1114                 }
1115                 if (!n) {
1116                         libwebsocket_close_and_free_session(this, wsi);
1117                         return 1;
1118                 }
1119
1120                 /* service incoming data */
1121
1122                 n = libwebsocket_read(this, wsi, buf, n);
1123                 if (n >= 0)
1124                         break;
1125
1126                 /* we closed wsi */
1127
1128                 return 1;
1129         }
1130
1131         return 0;
1132 }
1133
1134
1135 /**
1136  * libwebsocket_context_destroy() - Destroy the websocket context
1137  * @this:       Websocket context
1138  *
1139  *      This function closes any active connections and then frees the
1140  *      context.  After calling this, any further use of the context is
1141  *      undefined.
1142  */
1143 void
1144 libwebsocket_context_destroy(struct libwebsocket_context *this)
1145 {
1146         int n;
1147         int m;
1148         struct libwebsocket *wsi;
1149
1150         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1151                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1152                         wsi = this->fd_hashtable[n].wsi[m];
1153                         libwebsocket_close_and_free_session(this, wsi);
1154                 }
1155
1156         close(this->fd_random);
1157
1158 #ifdef LWS_OPENSSL_SUPPORT
1159         if (this->ssl_ctx)
1160                 SSL_CTX_free(this->ssl_ctx);
1161         if (this->ssl_client_ctx)
1162                 SSL_CTX_free(this->ssl_client_ctx);
1163 #endif
1164
1165         free(this);
1166 }
1167
1168 /**
1169  * libwebsocket_service() - Service any pending websocket activity
1170  * @this:       Websocket context
1171  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
1172  *              service otherwise block and service immediately, returning
1173  *              after the timeout if nothing needed service.
1174  *
1175  *      This function deals with any pending websocket traffic, for three
1176  *      kinds of event.  It handles these events on both server and client
1177  *      types of connection the same.
1178  *
1179  *      1) Accept new connections to our context's server
1180  *
1181  *      2) Perform pending broadcast writes initiated from other forked
1182  *         processes (effectively serializing asynchronous broadcasts)
1183  *
1184  *      3) Call the receive callback for incoming frame data received by
1185  *          server or client connections.
1186  *
1187  *      You need to call this service function periodically to all the above
1188  *      functions to happen; if your application is single-threaded you can
1189  *      just call it in your main event loop.
1190  *
1191  *      Alternatively you can fork a new process that asynchronously handles
1192  *      calling this service in a loop.  In that case you are happy if this
1193  *      call blocks your thread until it needs to take care of something and
1194  *      would call it with a large nonzero timeout.  Your loop then takes no
1195  *      CPU while there is nothing happening.
1196  *
1197  *      If you are calling it in a single-threaded app, you don't want it to
1198  *      wait around blocking other things in your loop from happening, so you
1199  *      would call it with a timeout_ms of 0, so it returns immediately if
1200  *      nothing is pending, or as soon as it services whatever was pending.
1201  */
1202
1203
1204 int
1205 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
1206 {
1207         int n;
1208
1209         /* stay dead once we are dead */
1210
1211         if (this == NULL)
1212                 return 1;
1213
1214         /* wait for something to need service */
1215
1216         n = poll(this->fds, this->fds_count, timeout_ms);
1217         if (n == 0) /* poll timeout */
1218                 return 0;
1219
1220         if (n < 0) {
1221                 /*
1222                 fprintf(stderr, "Listen Socket dead\n");
1223                 */
1224                 return 1;
1225         }
1226
1227         /* handle accept on listening socket? */
1228
1229         for (n = 0; n < this->fds_count; n++)
1230                 if (this->fds[n].revents)
1231                         libwebsocket_service_fd(this, &this->fds[n]);
1232
1233         return 0;
1234 }
1235
1236 /**
1237  * libwebsocket_callback_on_writable() - Request a callback when this socket
1238  *                                       becomes able to be written to without
1239  *                                       blocking
1240  *
1241  * @this:       libwebsockets context
1242  * @wsi:        Websocket connection instance to get callback for
1243  */
1244
1245 int
1246 libwebsocket_callback_on_writable(struct libwebsocket_context *this,
1247                                                        struct libwebsocket *wsi)
1248 {
1249         int n;
1250
1251         for (n = 0; n < this->fds_count; n++)
1252                 if (this->fds[n].fd == wsi->sock) {
1253                         this->fds[n].events |= POLLOUT;
1254                         n = this->fds_count;
1255                 }
1256
1257         /* external POLL support via protocol 0 */
1258         this->protocols[0].callback(this, wsi,
1259                 LWS_CALLBACK_SET_MODE_POLL_FD,
1260                 (void *)(long)wsi->sock, NULL, POLLOUT);
1261
1262         return 1;
1263 }
1264
1265 /**
1266  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
1267  *                      all connections using the given protocol when it
1268  *                      becomes possible to write to each socket without
1269  *                      blocking in turn.
1270  *
1271  * @protocol:   Protocol whose connections will get callbacks
1272  */
1273
1274 int
1275 libwebsocket_callback_on_writable_all_protocol(
1276                                   const struct libwebsocket_protocols *protocol)
1277 {
1278         struct libwebsocket_context *this = protocol->owning_server;
1279         int n;
1280         int m;
1281         struct libwebsocket *wsi;
1282
1283         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1284
1285                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1286
1287                         wsi = this->fd_hashtable[n].wsi[m];
1288
1289                         if (wsi->protocol == protocol)
1290                                 libwebsocket_callback_on_writable(this, wsi);
1291                 }
1292         }
1293
1294         return 0;
1295 }
1296
1297 /**
1298  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
1299  *
1300  * You will not need this unless you are doing something special
1301  *
1302  * @wsi:        Websocket connection instance
1303  * @reason:     timeout reason
1304  * @secs:       how many seconds
1305  */
1306
1307 void
1308 libwebsocket_set_timeout(struct libwebsocket *wsi,
1309                                           enum pending_timeout reason, int secs)
1310 {
1311         struct timeval tv;
1312
1313         gettimeofday(&tv, NULL);
1314
1315         wsi->pending_timeout_limit = tv.tv_sec + secs;
1316         wsi->pending_timeout = reason;
1317 }
1318
1319
1320 /**
1321  * libwebsocket_get_socket_fd() - returns the socket file descriptor
1322  *
1323  * You will not need this unless you are doing something special
1324  *
1325  * @wsi:        Websocket connection instance
1326  */
1327
1328 int
1329 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
1330 {
1331         return wsi->sock;
1332 }
1333
1334 /**
1335  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
1336  *                              receieved packets.
1337  *
1338  * If the output side of a server process becomes choked, this allows flow
1339  * control for the input side.
1340  *
1341  * @wsi:        Websocket connection instance to get callback for
1342  * @enable:     0 = disable read servicing for this connection, 1 = enable
1343  */
1344
1345 int
1346 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
1347 {
1348         struct libwebsocket_context *this = wsi->protocol->owning_server;
1349         int n;
1350
1351         for (n = 0; n < this->fds_count; n++)
1352                 if (this->fds[n].fd == wsi->sock) {
1353                         if (enable)
1354                                 this->fds[n].events |= POLLIN;
1355                         else
1356                                 this->fds[n].events &= ~POLLIN;
1357
1358                         return 0;
1359                 }
1360
1361         if (enable)
1362                 /* external POLL support via protocol 0 */
1363                 this->protocols[0].callback(this, wsi,
1364                         LWS_CALLBACK_SET_MODE_POLL_FD,
1365                         (void *)(long)wsi->sock, NULL, POLLIN);
1366         else
1367                 /* external POLL support via protocol 0 */
1368                 this->protocols[0].callback(this, wsi,
1369                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1370                         (void *)(long)wsi->sock, NULL, POLLIN);
1371
1372
1373         fprintf(stderr, "libwebsocket_callback_on_writable "
1374                                                      "unable to find socket\n");
1375         return 1;
1376 }
1377
1378 /**
1379  * libwebsocket_canonical_hostname() - returns this host's hostname
1380  *
1381  * This is typically used by client code to fill in the host parameter
1382  * when making a client connection.  You can only call it after the context
1383  * has been created.
1384  *
1385  * @this:       Websocket context
1386  */
1387
1388
1389 extern const char *
1390 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
1391 {
1392         return (const char *)this->canonical_hostname;
1393 }
1394
1395
1396 static void sigpipe_handler(int x)
1397 {
1398 }
1399
1400 #ifdef LWS_OPENSSL_SUPPORT
1401 static int
1402 OpenSSL_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
1403 {
1404
1405         SSL *ssl;
1406         int n;
1407 //      struct libwebsocket_context *this;
1408
1409         ssl = X509_STORE_CTX_get_ex_data(x509_ctx,
1410                 SSL_get_ex_data_X509_STORE_CTX_idx());
1411
1412         /*
1413          * !!! can't get this->openssl_websocket_private_data_index
1414          * can't store as a static either
1415          */
1416 //      this = SSL_get_ex_data(ssl, this->openssl_websocket_private_data_index);
1417
1418         n = this->protocols[0].callback(NULL, NULL,
1419                 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
1420                                                    x509_ctx, ssl, preverify_ok);
1421
1422         /* convert return code from 0 = OK to 1 = OK */
1423
1424         if (!n)
1425                 n = 1;
1426         else
1427                 n = 0;
1428
1429         return n;
1430 }
1431 #endif
1432
1433
1434 /**
1435  * libwebsocket_create_context() - Create the websocket handler
1436  * @port:       Port to listen on... you can use 0 to suppress listening on
1437  *              any port, that's what you want if you are not running a
1438  *              websocket server at all but just using it as a client
1439  * @interface:  NULL to bind the listen socket to all interfaces, or the
1440  *              interface name, eg, "eth2"
1441  * @protocols:  Array of structures listing supported protocols and a protocol-
1442  *              specific callback for each one.  The list is ended with an
1443  *              entry that has a NULL callback pointer.
1444  *              It's not const because we write the owning_server member
1445  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
1446  *                      to listen using SSL, set to the filepath to fetch the
1447  *                      server cert from, otherwise NULL for unencrypted
1448  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
1449  *                      else ignored
1450  * @gid:        group id to change to after setting listen socket, or -1.
1451  * @uid:        user id to change to after setting listen socket, or -1.
1452  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
1453  *
1454  *      This function creates the listening socket and takes care
1455  *      of all initialization in one step.
1456  *
1457  *      After initialization, it returns a struct libwebsocket_context * that
1458  *      represents this server.  After calling, user code needs to take care
1459  *      of calling libwebsocket_service() with the context pointer to get the
1460  *      server's sockets serviced.  This can be done in the same process context
1461  *      or a forked process, or another thread,
1462  *
1463  *      The protocol callback functions are called for a handful of events
1464  *      including http requests coming in, websocket connections becoming
1465  *      established, and data arriving; it's also called periodically to allow
1466  *      async transmission.
1467  *
1468  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
1469  *      at that time websocket protocol has not been negotiated.  Other
1470  *      protocols after the first one never see any HTTP callack activity.
1471  *
1472  *      The server created is a simple http server by default; part of the
1473  *      websocket standard is upgrading this http connection to a websocket one.
1474  *
1475  *      This allows the same server to provide files like scripts and favicon /
1476  *      images or whatever over http and dynamic data over websockets all in
1477  *      one place; they're all handled in the user callback.
1478  */
1479
1480 struct libwebsocket_context *
1481 libwebsocket_create_context(int port, const char *interface,
1482                                struct libwebsocket_protocols *protocols,
1483                                const char *ssl_cert_filepath,
1484                                const char *ssl_private_key_filepath,
1485                                int gid, int uid, unsigned int options)
1486 {
1487         int n;
1488         int sockfd = 0;
1489         int fd;
1490         struct sockaddr_in serv_addr, cli_addr;
1491         int opt = 1;
1492         struct libwebsocket_context *this = NULL;
1493         unsigned int slen;
1494         char *p;
1495         char hostname[1024];
1496         struct hostent *he;
1497         struct libwebsocket *wsi;
1498
1499 #ifdef LWS_OPENSSL_SUPPORT
1500         SSL_METHOD *method;
1501         char ssl_err_buf[512];
1502 #endif
1503
1504         this = malloc(sizeof(struct libwebsocket_context));
1505         if (!this) {
1506                 fprintf(stderr, "No memory for websocket context\n");
1507                 return NULL;
1508         }
1509         this->protocols = protocols;
1510         this->listen_port = port;
1511         this->http_proxy_port = 0;
1512         this->http_proxy_address[0] = '\0';
1513         this->options = options;
1514         this->fds_count = 0;
1515
1516         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
1517         if (this->fd_random < 0) {
1518                 fprintf(stderr, "Unable to open random device %s %d\n",
1519                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
1520                 return NULL;
1521         }
1522
1523         /* find canonical hostname */
1524
1525         hostname[(sizeof hostname) - 1] = '\0';
1526         gethostname(hostname, (sizeof hostname) - 1);
1527         he = gethostbyname(hostname);
1528         if (he) {
1529                 strncpy(this->canonical_hostname, he->h_name,
1530                                            sizeof this->canonical_hostname - 1);
1531                 this->canonical_hostname[sizeof this->canonical_hostname - 1] =
1532                                                                            '\0';
1533         } else
1534                 strncpy(this->canonical_hostname, hostname,
1535                                            sizeof this->canonical_hostname - 1);
1536
1537         /* split the proxy ads:port if given */
1538
1539         p = getenv("http_proxy");
1540         if (p) {
1541                 strncpy(this->http_proxy_address, p,
1542                                            sizeof this->http_proxy_address - 1);
1543                 this->http_proxy_address[
1544                                     sizeof this->http_proxy_address - 1] = '\0';
1545
1546                 p = strchr(this->http_proxy_address, ':');
1547                 if (p == NULL) {
1548                         fprintf(stderr, "http_proxy needs to be ads:port\n");
1549                         return NULL;
1550                 }
1551                 *p = '\0';
1552                 this->http_proxy_port = atoi(p + 1);
1553
1554                 fprintf(stderr, "Using proxy %s:%u\n",
1555                                 this->http_proxy_address,
1556                                                         this->http_proxy_port);
1557         }
1558
1559         if (port) {
1560
1561 #ifdef LWS_OPENSSL_SUPPORT
1562                 this->use_ssl = ssl_cert_filepath != NULL &&
1563                                                ssl_private_key_filepath != NULL;
1564                 if (this->use_ssl)
1565                         fprintf(stderr, " Compiled with SSL support, "
1566                                                                   "using it\n");
1567                 else
1568                         fprintf(stderr, " Compiled with SSL support, "
1569                                                               "not using it\n");
1570
1571 #else
1572                 if (ssl_cert_filepath != NULL &&
1573                                              ssl_private_key_filepath != NULL) {
1574                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
1575                         return NULL;
1576                 }
1577                 fprintf(stderr, " Compiled without SSL support, "
1578                                                        "serving unencrypted\n");
1579 #endif
1580         }
1581
1582         /* ignore SIGPIPE */
1583
1584         signal(SIGPIPE, sigpipe_handler);
1585
1586
1587 #ifdef LWS_OPENSSL_SUPPORT
1588
1589         /* basic openssl init */
1590
1591         SSL_library_init();
1592
1593         OpenSSL_add_all_algorithms();
1594         SSL_load_error_strings();
1595
1596         this->openssl_websocket_private_data_index =
1597                 SSL_get_ex_new_index(0, "libwebsockets", NULL, NULL, NULL);
1598
1599         /*
1600          * Firefox insists on SSLv23 not SSLv3
1601          * Konq disables SSLv2 by default now, SSLv23 works
1602          */
1603
1604         method = (SSL_METHOD *)SSLv23_server_method();
1605         if (!method) {
1606                 fprintf(stderr, "problem creating ssl method: %s\n",
1607                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1608                 return NULL;
1609         }
1610         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
1611         if (!this->ssl_ctx) {
1612                 fprintf(stderr, "problem creating ssl context: %s\n",
1613                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1614                 return NULL;
1615         }
1616
1617         /* client context */
1618
1619         method = (SSL_METHOD *)SSLv23_client_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_client_ctx = SSL_CTX_new(method);     /* create context */
1626         if (!this->ssl_client_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
1633         /* openssl init for cert verification (used with client sockets) */
1634
1635         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
1636                                                     LWS_OPENSSL_CLIENT_CERTS)) {
1637                 fprintf(stderr, "Unable to load SSL Client certs from %s "
1638                         "(set by --with-client-cert-dir= in configure) -- "
1639                         " client ssl isn't going to work",
1640                                                       LWS_OPENSSL_CLIENT_CERTS);
1641         }
1642
1643         /*
1644          * callback allowing user code to load extra verification certs
1645          * helping the client to verify server identity
1646          */
1647
1648         this->protocols[0].callback(this, NULL,
1649                 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
1650                 this->ssl_client_ctx, NULL, 0);
1651
1652         /* as a server, are we requiring clients to identify themselves? */
1653
1654         if (options & LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT) {
1655
1656                 /* absolutely require the client cert */
1657
1658                 SSL_CTX_set_verify(this->ssl_ctx,
1659                        SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
1660                                                        OpenSSL_verify_callback);
1661
1662                 /*
1663                  * give user code a chance to load certs into the server
1664                  * allowing it to verify incoming client certs
1665                  */
1666
1667                 this->protocols[0].callback(this, NULL,
1668                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
1669                                                         this->ssl_ctx, NULL, 0);
1670         }
1671
1672         if (this->use_ssl) {
1673
1674                 /* openssl init for server sockets */
1675
1676                 /* set the local certificate from CertFile */
1677                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
1678                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
1679                 if (n != 1) {
1680                         fprintf(stderr, "problem getting cert '%s': %s\n",
1681                                 ssl_cert_filepath,
1682                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1683                         return NULL;
1684                 }
1685                 /* set the private key from KeyFile */
1686                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
1687                                                 ssl_private_key_filepath,
1688                                                        SSL_FILETYPE_PEM) != 1) {
1689                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
1690                                                 ssl_private_key_filepath,
1691                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1692                         return NULL;
1693                 }
1694                 /* verify private key */
1695                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
1696                         fprintf(stderr, "Private SSL key doesn't match cert\n");
1697                         return NULL;
1698                 }
1699
1700                 /* SSL is happy and has a cert it's content with */
1701         }
1702 #endif
1703
1704         /* selftest */
1705
1706         if (lws_b64_selftest())
1707                 return NULL;
1708
1709         /* fd hashtable init */
1710
1711         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1712                 this->fd_hashtable[n].length = 0;
1713
1714         /* set up our external listening socket we serve on */
1715
1716         if (port) {
1717
1718                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1719                 if (sockfd < 0) {
1720                         fprintf(stderr, "ERROR opening socket");
1721                         return NULL;
1722                 }
1723
1724                 /* allow us to restart even if old sockets in TIME_WAIT */
1725                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1726
1727                 bzero((char *) &serv_addr, sizeof(serv_addr));
1728                 serv_addr.sin_family = AF_INET;
1729                 if (interface == NULL)
1730                         serv_addr.sin_addr.s_addr = INADDR_ANY;
1731                 else
1732                         interface_to_sa(interface, &serv_addr,
1733                                                 sizeof(serv_addr));
1734                 serv_addr.sin_port = htons(port);
1735
1736                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
1737                                                              sizeof(serv_addr));
1738                 if (n < 0) {
1739                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1740                                                                 port, n, errno);
1741                         return NULL;
1742                 }
1743
1744                 wsi = malloc(sizeof(struct libwebsocket));
1745                 memset(wsi, 0, sizeof (struct libwebsocket));
1746                 wsi->sock = sockfd;
1747                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
1748                 insert_wsi(this, wsi);
1749
1750                 listen(sockfd, 5);
1751                 fprintf(stderr, " Listening on port %d\n", port);
1752
1753                 /* list in the internal poll array */
1754
1755                 this->fds[this->fds_count].fd = sockfd;
1756                 this->fds[this->fds_count++].events = POLLIN;
1757
1758                 /* external POLL support via protocol 0 */
1759                 this->protocols[0].callback(this, wsi,
1760                         LWS_CALLBACK_ADD_POLL_FD,
1761                         (void *)(long)sockfd, NULL, POLLIN);
1762
1763         }
1764
1765         /* drop any root privs for this process */
1766
1767         if (gid != -1)
1768                 if (setgid(gid))
1769                         fprintf(stderr, "setgid: %s\n", strerror(errno));
1770         if (uid != -1)
1771                 if (setuid(uid))
1772                         fprintf(stderr, "setuid: %s\n", strerror(errno));
1773
1774
1775         /* set up our internal broadcast trigger sockets per-protocol */
1776
1777         for (this->count_protocols = 0;
1778                         protocols[this->count_protocols].callback;
1779                                                       this->count_protocols++) {
1780                 protocols[this->count_protocols].owning_server = this;
1781                 protocols[this->count_protocols].protocol_index =
1782                                                           this->count_protocols;
1783
1784                 fd = socket(AF_INET, SOCK_STREAM, 0);
1785                 if (fd < 0) {
1786                         fprintf(stderr, "ERROR opening socket");
1787                         return NULL;
1788                 }
1789
1790                 /* allow us to restart even if old sockets in TIME_WAIT */
1791                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1792
1793                 bzero((char *) &serv_addr, sizeof(serv_addr));
1794                 serv_addr.sin_family = AF_INET;
1795                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1796                 serv_addr.sin_port = 0; /* pick the port for us */
1797
1798                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
1799                 if (n < 0) {
1800                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1801                                                                 port, n, errno);
1802                         return NULL;
1803                 }
1804
1805                 slen = sizeof cli_addr;
1806                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
1807                 if (n < 0) {
1808                         fprintf(stderr, "getsockname failed\n");
1809                         return NULL;
1810                 }
1811                 protocols[this->count_protocols].broadcast_socket_port =
1812                                                        ntohs(cli_addr.sin_port);
1813                 listen(fd, 5);
1814
1815                 debug("  Protocol %s broadcast socket %d\n",
1816                                 protocols[this->count_protocols].name,
1817                                                       ntohs(cli_addr.sin_port));
1818
1819                 /* dummy wsi per broadcast proxy socket */
1820
1821                 wsi = malloc(sizeof(struct libwebsocket));
1822                 memset(wsi, 0, sizeof (struct libwebsocket));
1823                 wsi->sock = fd;
1824                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
1825                 /* note which protocol we are proxying */
1826                 wsi->protocol_index_for_broadcast_proxy = this->count_protocols;
1827                 insert_wsi(this, wsi);
1828
1829                 /* list in internal poll array */
1830
1831                 this->fds[this->fds_count].fd = fd;
1832                 this->fds[this->fds_count].events = POLLIN;
1833                 this->fds[this->fds_count].revents = 0;
1834                 this->fds_count++;
1835
1836                 /* external POLL support via protocol 0 */
1837                 this->protocols[0].callback(this, wsi,
1838                         LWS_CALLBACK_ADD_POLL_FD,
1839                         (void *)(long)fd, NULL, POLLIN);
1840         }
1841
1842         return this;
1843 }
1844
1845
1846 #ifndef LWS_NO_FORK
1847
1848 /**
1849  * libwebsockets_fork_service_loop() - Optional helper function forks off
1850  *                                a process for the websocket server loop.
1851  *                              You don't have to use this but if not, you
1852  *                              have to make sure you are calling
1853  *                              libwebsocket_service periodically to service
1854  *                              the websocket traffic
1855  * @this:       server context returned by creation function
1856  */
1857
1858 int
1859 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
1860 {
1861         int fd;
1862         struct sockaddr_in cli_addr;
1863         int n;
1864         int p;
1865
1866         n = fork();
1867         if (n < 0)
1868                 return n;
1869
1870         if (!n) {
1871
1872                 /* main process context */
1873
1874                 /*
1875                  * set up the proxy sockets to allow broadcast from
1876                  * service process context
1877                  */
1878
1879                 for (p = 0; p < this->count_protocols; p++) {
1880                         fd = socket(AF_INET, SOCK_STREAM, 0);
1881                         if (fd < 0) {
1882                                 fprintf(stderr, "Unable to create socket\n");
1883                                 return -1;
1884                         }
1885                         cli_addr.sin_family = AF_INET;
1886                         cli_addr.sin_port = htons(
1887                              this->protocols[p].broadcast_socket_port);
1888                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1889                         n = connect(fd, (struct sockaddr *)&cli_addr,
1890                                                                sizeof cli_addr);
1891                         if (n < 0) {
1892                                 fprintf(stderr, "Unable to connect to "
1893                                                 "broadcast socket %d, %s\n",
1894                                                 n, strerror(errno));
1895                                 return -1;
1896                         }
1897
1898                         this->protocols[p].broadcast_socket_user_fd = fd;
1899                 }
1900
1901                 return 0;
1902         }
1903
1904         /* we want a SIGHUP when our parent goes down */
1905         prctl(PR_SET_PDEATHSIG, SIGHUP);
1906
1907         /* in this forked process, sit and service websocket connections */
1908
1909         while (1)
1910                 if (libwebsocket_service(this, 1000))
1911                         return -1;
1912
1913         return 0;
1914 }
1915
1916 #endif
1917
1918 /**
1919  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1920  *                                connection.
1921  * @wsi:        pointer to struct websocket you want to know the protocol of
1922  *
1923  *
1924  *      This is useful to get the protocol to broadcast back to from inside
1925  * the callback.
1926  */
1927
1928 const struct libwebsocket_protocols *
1929 libwebsockets_get_protocol(struct libwebsocket *wsi)
1930 {
1931         return wsi->protocol;
1932 }
1933
1934 /**
1935  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1936  *                                connections of the given protocol.
1937  * @protocol:   pointer to the protocol you will broadcast to all members of
1938  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1939  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1940  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1941  *              case you are calling this function from callback context.
1942  * @len:        length of payload data in buf, starting from buf.
1943  *
1944  *      This function allows bulk sending of a packet to every connection using
1945  * the given protocol.  It does not send the data directly; instead it calls
1946  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1947  * wants to actually send the data for that connection, the callback itself
1948  * should call libwebsocket_write().
1949  *
1950  * libwebsockets_broadcast() can be called from another fork context without
1951  * having to take any care about data visibility between the processes, it'll
1952  * "just work".
1953  */
1954
1955
1956 int
1957 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1958                                                  unsigned char *buf, size_t len)
1959 {
1960         struct libwebsocket_context *this = protocol->owning_server;
1961         int n;
1962         int m;
1963         struct libwebsocket * wsi;
1964
1965         if (!protocol->broadcast_socket_user_fd) {
1966                 /*
1967                  * We are either running unforked / flat, or we are being
1968                  * called from poll thread context
1969                  * eg, from a callback.  In that case don't use sockets for
1970                  * broadcast IPC (since we can't open a socket connection to
1971                  * a socket listening on our own thread) but directly do the
1972                  * send action.
1973                  *
1974                  * Locking is not needed because we are by definition being
1975                  * called in the poll thread context and are serialized.
1976                  */
1977
1978                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1979
1980                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
1981
1982                                 wsi = this->fd_hashtable[n].wsi[m];
1983
1984                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
1985                                         continue;
1986
1987                                 /*
1988                                  * never broadcast to
1989                                  * non-established connections
1990                                  */
1991                                 if (wsi->state != WSI_STATE_ESTABLISHED)
1992                                         continue;
1993
1994                                 /* only broadcast to guys using
1995                                  * requested protocol
1996                                  */
1997                                 if (wsi->protocol != protocol)
1998                                         continue;
1999
2000                                 wsi->protocol->callback(this, wsi,
2001                                          LWS_CALLBACK_BROADCAST,
2002                                          wsi->user_space,
2003                                          buf, len);
2004                         }
2005                 }
2006
2007                 return 0;
2008         }
2009
2010         /*
2011          * We're being called from a different process context than the server
2012          * loop.  Instead of broadcasting directly, we send our
2013          * payload on a socket to do the IPC; the server process will serialize
2014          * the broadcast action in its main poll() loop.
2015          *
2016          * There's one broadcast socket listening for each protocol supported
2017          * set up when the websocket server initializes
2018          */
2019
2020         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
2021
2022         return n;
2023 }