lib/libwebsockets.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23 #include <ifaddrs.h>
  24
  25 /*
  26  * In-place str to lower case
  27  */
  28
  29 static void
  30 strtolower(char *s)
  31 {
  32         while (*s) {
  33                 *s = tolower(*s);
  34                 s++;
  35         }
  36 }
  37
  38 /* file descriptor hash management */
  39
  40 struct libwebsocket *
  41 wsi_from_fd(struct libwebsocket_context *this, int fd)
  42 {
  43         int h = LWS_FD_HASH(fd);
  44         int n = 0;
  45
  46         for (n = 0; n < this->fd_hashtable[h].length; n++)
  47                 if (this->fd_hashtable[h].wsi[n]->sock == fd)
  48                         return this->fd_hashtable[h].wsi[n];
  49
  50         return NULL;
  51 }
  52
  53 int
  54 insert_wsi(struct libwebsocket_context *this, struct libwebsocket *wsi)
  55 {
  56         int h = LWS_FD_HASH(wsi->sock);
  57
  58         if (this->fd_hashtable[h].length == MAX_CLIENTS - 1) {
  59                 fprintf(stderr, "hash table overflow\n");
  60                 return 1;
  61         }
  62
  63         this->fd_hashtable[h].wsi[this->fd_hashtable[h].length++] = wsi;
  64
  65         return 0;
  66 }
  67
  68 int
  69 delete_from_fd(struct libwebsocket_context *this, int fd)
  70 {
  71         int h = LWS_FD_HASH(fd);
  72         int n = 0;
  73
  74         for (n = 0; n < this->fd_hashtable[h].length; n++)
  75                 if (this->fd_hashtable[h].wsi[n]->sock == fd) {
  76                         while (n < this->fd_hashtable[h].length) {
  77                                 this->fd_hashtable[h].wsi[n] =
  78                                                this->fd_hashtable[h].wsi[n + 1];
  79                                 n++;
  80                         }
  81                         this->fd_hashtable[h].length--;
  82
  83                         return 0;
  84                 }
  85
  86         fprintf(stderr, "Failed to find fd %d requested for "
  87                                                    "delete in hashtable\n", fd);
  88         return 1;
  89 }
  90
  91 #ifdef LWS_OPENSSL_SUPPORT
  92 static void
  93 libwebsockets_decode_ssl_error(void)
  94 {
  95         char buf[256];
  96         u_long err;
  97
  98         while ((err = ERR_get_error()) != 0) {
  99                 ERR_error_string_n(err, buf, sizeof(buf));
 100                 fprintf(stderr, "*** %s\n", buf);
 101         }
 102 }
 103 #endif
 104
 105
 106 static int
 107 interface_to_sa(const char* ifname, struct sockaddr_in *addr, size_t addrlen)
 108 {
 109         int rc = -1;
 110         struct ifaddrs *ifr;
 111         struct ifaddrs *ifc;
 112         struct sockaddr_in *sin;
 113
 114         getifaddrs(&ifr);
 115         for (ifc = ifr; ifc != NULL; ifc = ifc->ifa_next) {
 116                 if (strcmp(ifc->ifa_name, ifname))
 117                         continue;
 118                 if (ifc->ifa_addr == NULL)
 119                         continue;
 120                 sin = (struct sockaddr_in *)ifc->ifa_addr;
 121                 if (sin->sin_family != AF_INET)
 122                         continue;
 123                 memcpy(addr, sin, addrlen);
 124                 rc = 0;
 125         }
 126
 127         freeifaddrs(ifr);
 128
 129         return rc;
 130 }
 131
 132 void
 133 libwebsocket_close_and_free_session(struct libwebsocket_context *this,
 134                          struct libwebsocket *wsi, enum lws_close_status reason)
 135 {
 136         int n;
 137         int old_state;
 138         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
 139                                                   LWS_SEND_BUFFER_POST_PADDING];
 140
 141         if (!wsi)
 142                 return;
 143
 144         old_state = wsi->state;
 145
 146         if (old_state == WSI_STATE_DEAD_SOCKET)
 147                 return;
 148
 149         /* remove this fd from wsi mapping hashtable */
 150
 151         delete_from_fd(this, wsi->sock);
 152
 153         /* delete it from the internal poll list if still present */
 154
 155         for (n = 0; n < this->fds_count; n++) {
 156                 if (this->fds[n].fd != wsi->sock)
 157                         continue;
 158                 while (n < this->fds_count - 1) {
 159                         this->fds[n] = this->fds[n + 1];
 160                         n++;
 161                 }
 162                 this->fds_count--;
 163                 /* we only have to deal with one */
 164                 n = this->fds_count;
 165         }
 166
 167         /* remove also from external POLL support via protocol 0 */
 168
 169         this->protocols[0].callback(this, wsi,
 170                     LWS_CALLBACK_DEL_POLL_FD, (void *)(long)wsi->sock, NULL, 0);
 171
 172         wsi->close_reason = reason;
 173
 174         /*
 175          * signal we are closing, libsocket_write will
 176          * add any necessary version-specific stuff.  If the write fails,
 177          * no worries we are closing anyway.  If we didn't initiate this
 178          * close, then our state has been changed to
 179          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this
 180          */
 181
 182         if (old_state == WSI_STATE_ESTABLISHED)
 183                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
 184                                                                LWS_WRITE_CLOSE);
 185
 186         wsi->state = WSI_STATE_DEAD_SOCKET;
 187
 188         /* tell the user it's all over for this guy */
 189
 190         if (wsi->protocol && wsi->protocol->callback &&
 191                                              old_state == WSI_STATE_ESTABLISHED)
 192                 wsi->protocol->callback(this, wsi, LWS_CALLBACK_CLOSED,
 193                                                       wsi->user_space, NULL, 0);
 194
 195         /* free up his allocations */
 196
 197         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 198                 if (wsi->utf8_token[n].token)
 199                         free(wsi->utf8_token[n].token);
 200
 201 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 202
 203 #ifdef LWS_OPENSSL_SUPPORT
 204         if (wsi->ssl) {
 205                 n = SSL_get_fd(wsi->ssl);
 206                 SSL_shutdown(wsi->ssl);
 207                 close(n);
 208                 SSL_free(wsi->ssl);
 209         } else {
 210 #endif
 211                 shutdown(wsi->sock, SHUT_RDWR);
 212                 close(wsi->sock);
 213 #ifdef LWS_OPENSSL_SUPPORT
 214         }
 215 #endif
 216         if (wsi->user_space)
 217                 free(wsi->user_space);
 218
 219         free(wsi);
 220 }
 221
 222 /**
 223  * libwebsockets_hangup_on_client() - Server calls to terminate client
 224  *                                      connection
 225  * @this:       libwebsockets context
 226  * @fd:         Connection socket descriptor
 227  */
 228
 229 void
 230 libwebsockets_hangup_on_client(struct libwebsocket_context *this, int fd)
 231 {
 232         struct libwebsocket *wsi = wsi_from_fd(this, fd);
 233
 234         if (wsi == NULL)
 235                 return;
 236
 237         libwebsocket_close_and_free_session(this, wsi,
 238                                                      LWS_CLOSE_STATUS_NOSTATUS);
 239 }
 240
 241
 242 /**
 243  * libwebsockets_get_peer_addresses() - Get client address information
 244  * @fd:         Connection socket descriptor
 245  * @name:       Buffer to take client address name
 246  * @name_len:   Length of client address name buffer
 247  * @rip:        Buffer to take client address IP qotted quad
 248  * @rip_len:    Length of client address IP buffer
 249  *
 250  *      This function fills in @name and @rip with the name and IP of
 251  *      the client connected with socket descriptor @fd.  Names may be
 252  *      truncated if there is not enough room.  If either cannot be
 253  *      determined, they will be returned as valid zero-length strings.
 254  */
 255
 256 void
 257 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 258                                         char *rip, int rip_len)
 259 {
 260         unsigned int len;
 261         struct sockaddr_in sin;
 262         struct hostent *host;
 263         struct hostent *host1;
 264         char ip[128];
 265         char *p;
 266         int n;
 267
 268         rip[0] = '\0';
 269         name[0] = '\0';
 270
 271         len = sizeof sin;
 272         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 273                 perror("getpeername");
 274                 return;
 275         }
 276
 277         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 278                                                                        AF_INET);
 279         if (host == NULL) {
 280                 perror("gethostbyaddr");
 281                 return;
 282         }
 283
 284         strncpy(name, host->h_name, name_len);
 285         name[name_len - 1] = '\0';
 286
 287         host1 = gethostbyname(host->h_name);
 288         if (host1 == NULL)
 289                 return;
 290         p = (char *)host1;
 291         n = 0;
 292         while (p != NULL) {
 293                 p = host1->h_addr_list[n++];
 294                 if (p == NULL)
 295                         continue;
 296                 if (host1->h_addrtype != AF_INET)
 297                         continue;
 298
 299                 sprintf(ip, "%d.%d.%d.%d",
 300                                 p[0], p[1], p[2], p[3]);
 301                 p = NULL;
 302                 strncpy(rip, ip, rip_len);
 303                 rip[rip_len - 1] = '\0';
 304         }
 305 }
 306
 307 /**
 308  * libwebsocket_service_fd() - Service polled socket with something waiting
 309  * @this:       Websocket context
 310  * @pollfd:     The pollfd entry describing the socket fd and which events
 311  *              happened.
 312  *
 313  *      This function closes any active connections and then frees the
 314  *      context.  After calling this, any further use of the context is
 315  *      undefined.
 316  */
 317
 318 int
 319 libwebsocket_service_fd(struct libwebsocket_context *this,
 320                                                           struct pollfd *pollfd)
 321 {
 322         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
 323                                                   LWS_SEND_BUFFER_POST_PADDING];
 324         struct libwebsocket *wsi;
 325         struct libwebsocket *new_wsi;
 326         int n;
 327         int m;
 328         size_t len;
 329         int accept_fd;
 330         unsigned int clilen;
 331         struct sockaddr_in cli_addr;
 332         struct timeval tv;
 333         static const char magic_websocket_guid[] =
 334                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 335         static const char magic_websocket_04_masking_guid[] =
 336                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 337         char hash[20];
 338         char pkt[1024];
 339         char *p = &pkt[0];
 340         const char *pc;
 341         int okay = 0;
 342 #ifdef LWS_OPENSSL_SUPPORT
 343         char ssl_err_buf[512];
 344 #endif
 345         /*
 346          * you can call us with pollfd = NULL to just allow the once-per-second
 347          * global timeout checks; if less than a second since the last check
 348          * it returns immediately then.
 349          */
 350
 351         gettimeofday(&tv, NULL);
 352
 353         if (this->last_timeout_check_s != tv.tv_sec) {
 354                 this->last_timeout_check_s = tv.tv_sec;
 355
 356                 /* global timeout check once per second */
 357
 358                 for (n = 0; n < this->fds_count; n++) {
 359                         wsi = wsi_from_fd(this, this->fds[n].fd);
 360                         if (!wsi->pending_timeout)
 361                                 continue;
 362
 363                         /*
 364                          * if we went beyond the allowed time, kill the
 365                          * connection
 366                          */
 367
 368                         if (tv.tv_sec > wsi->pending_timeout_limit)
 369                                 libwebsocket_close_and_free_session(this, wsi,
 370                                                      LWS_CLOSE_STATUS_NOSTATUS);
 371                 }
 372         }
 373
 374         /* just here for timeout management? */
 375
 376         if (pollfd == NULL)
 377                 return 0;
 378
 379         /* no, here to service a socket descriptor */
 380
 381         wsi = wsi_from_fd(this, pollfd->fd);
 382
 383         if (wsi == NULL)
 384                 return 1;
 385
 386         switch (wsi->mode) {
 387         case LWS_CONNMODE_SERVER_LISTENER:
 388
 389                 /* pollin means a client has connected to us then */
 390
 391                 if (!pollfd->revents & POLLIN)
 392                         break;
 393
 394                 /* listen socket got an unencrypted connection... */
 395
 396                 clilen = sizeof(cli_addr);
 397                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 398                                                                        &clilen);
 399                 if (accept_fd < 0) {
 400                         fprintf(stderr, "ERROR on accept");
 401                         break;
 402                 }
 403
 404                 if (this->fds_count >= MAX_CLIENTS) {
 405                         fprintf(stderr, "too busy to accept new client\n");
 406                         close(accept_fd);
 407                         break;
 408                 }
 409
 410                 /*
 411                  * look at who we connected to and give user code a chance
 412                  * to reject based on client IP.  There's no protocol selected
 413                  * yet so we issue this to protocols[0]
 414                  */
 415
 416                 if ((this->protocols[0].callback)(this, wsi,
 417                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 418                                              (void*)(long)accept_fd, NULL, 0)) {
 419                         fprintf(stderr, "Callback denied network connection\n");
 420                         close(accept_fd);
 421                         break;
 422                 }
 423
 424                 /* accepting connection to main listener */
 425
 426                 new_wsi = malloc(sizeof(struct libwebsocket));
 427                 if (new_wsi == NULL) {
 428                         fprintf(stderr, "Out of memory for new connection\n");
 429                         break;
 430                 }
 431
 432                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 433                 new_wsi->sock = accept_fd;
 434                 new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
 435
 436 #ifdef LWS_OPENSSL_SUPPORT
 437                 new_wsi->ssl = NULL;
 438
 439                 if (this->use_ssl) {
 440
 441                         new_wsi->ssl = SSL_new(this->ssl_ctx);
 442                         if (new_wsi->ssl == NULL) {
 443                                 fprintf(stderr, "SSL_new failed: %s\n",
 444                                     ERR_error_string(SSL_get_error(
 445                                     new_wsi->ssl, 0), NULL));
 446                                     libwebsockets_decode_ssl_error();
 447                                 free(new_wsi);
 448                                 break;
 449                         }
 450
 451                         SSL_set_fd(new_wsi->ssl, accept_fd);
 452
 453                         n = SSL_accept(new_wsi->ssl);
 454                         if (n != 1) {
 455                                 /*
 456                                  * browsers seem to probe with various
 457                                  * ssl params which fail then retry
 458                                  * and succeed
 459                                  */
 460                                 debug("SSL_accept failed skt %u: %s\n",
 461                                       pollfd->fd,
 462                                       ERR_error_string(SSL_get_error(
 463                                       new_wsi->ssl, n), NULL));
 464                                 SSL_free(
 465                                        new_wsi->ssl);
 466                                 free(new_wsi);
 467                                 break;
 468                         }
 469
 470                         debug("accepted new SSL conn  "
 471                               "port %u on fd=%d SSL ver %s\n",
 472                                 ntohs(cli_addr.sin_port), accept_fd,
 473                                   SSL_get_version(new_wsi->ssl));
 474
 475                 } else
 476 #endif
 477                         debug("accepted new conn  port %u on fd=%d\n",
 478                                           ntohs(cli_addr.sin_port), accept_fd);
 479
 480                 /* intialize the instance struct */
 481
 482                 new_wsi->state = WSI_STATE_HTTP;
 483                 new_wsi->name_buffer_pos = 0;
 484                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 485
 486                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 487                         new_wsi->utf8_token[n].token = NULL;
 488                         new_wsi->utf8_token[n].token_len = 0;
 489                 }
 490
 491                 /*
 492                  * these can only be set once the protocol is known
 493                  * we set an unestablished connection's protocol pointer
 494                  * to the start of the supported list, so it can look
 495                  * for matching ones during the handshake
 496                  */
 497                 new_wsi->protocol = this->protocols;
 498                 new_wsi->user_space = NULL;
 499
 500                 /*
 501                  * Default protocol is 76 / 00
 502                  * After 76, there's a header specified to inform which
 503                  * draft the client wants, when that's seen we modify
 504                  * the individual connection's spec revision accordingly
 505                  */
 506                 new_wsi->ietf_spec_revision = 0;
 507
 508                 insert_wsi(this, new_wsi);
 509
 510                 /*
 511                  * make sure NO events are seen yet on this new socket
 512                  * (otherwise we inherit old fds[client].revents from
 513                  * previous socket there and die mysteriously! )
 514                  */
 515                 this->fds[this->fds_count].revents = 0;
 516
 517                 this->fds[this->fds_count].events = POLLIN;
 518                 this->fds[this->fds_count++].fd = accept_fd;
 519
 520                 /* external POLL support via protocol 0 */
 521                 this->protocols[0].callback(this, new_wsi,
 522                         LWS_CALLBACK_ADD_POLL_FD,
 523                         (void *)(long)accept_fd, NULL, POLLIN);
 524
 525                 break;
 526
 527         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 528
 529                 /* as we are listening, POLLIN means accept() is needed */
 530
 531                 if (!pollfd->revents & POLLIN)
 532                         break;
 533
 534                 /* listen socket got an unencrypted connection... */
 535
 536                 clilen = sizeof(cli_addr);
 537                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 538                                                                        &clilen);
 539                 if (accept_fd < 0) {
 540                         fprintf(stderr, "ERROR on accept");
 541                         break;
 542                 }
 543
 544                 if (this->fds_count >= MAX_CLIENTS) {
 545                         fprintf(stderr, "too busy to accept new broadcast "
 546                                                               "proxy client\n");
 547                         close(accept_fd);
 548                         break;
 549                 }
 550
 551                 /* create a dummy wsi for the connection and add it */
 552
 553                 new_wsi = malloc(sizeof(struct libwebsocket));
 554                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 555                 new_wsi->sock = accept_fd;
 556                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 557                 new_wsi->state = WSI_STATE_ESTABLISHED;
 558                 /* note which protocol we are proxying */
 559                 new_wsi->protocol_index_for_broadcast_proxy =
 560                                         wsi->protocol_index_for_broadcast_proxy;
 561                 insert_wsi(this, new_wsi);
 562
 563                 /* add connected socket to internal poll array */
 564
 565                 this->fds[this->fds_count].revents = 0;
 566                 this->fds[this->fds_count].events = POLLIN;
 567                 this->fds[this->fds_count++].fd = accept_fd;
 568
 569                 /* external POLL support via protocol 0 */
 570                 this->protocols[0].callback(this, new_wsi,
 571                         LWS_CALLBACK_ADD_POLL_FD,
 572                         (void *)(long)accept_fd, NULL, POLLIN);
 573
 574                 break;
 575
 576         case LWS_CONNMODE_BROADCAST_PROXY:
 577
 578                 /* handle session socket closed */
 579
 580                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 581
 582                         debug("Session Socket %p (fd=%d) dead\n",
 583                                 (void *)wsi, pollfd->fd);
 584
 585                         libwebsocket_close_and_free_session(this, wsi,
 586                                                        LWS_CLOSE_STATUS_NORMAL);
 587                         return 1;
 588                 }
 589
 590                 /* the guy requested a callback when it was OK to write */
 591
 592                 if (pollfd->revents & POLLOUT) {
 593
 594                         /* one shot */
 595
 596                         pollfd->events &= ~POLLOUT;
 597
 598                         /* external POLL support via protocol 0 */
 599                         this->protocols[0].callback(this, wsi,
 600                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 601                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 602
 603                         wsi->protocol->callback(this, wsi,
 604                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 605                                 wsi->user_space,
 606                                 NULL, 0);
 607                 }
 608
 609                 /* any incoming data ready? */
 610
 611                 if (!(pollfd->revents & POLLIN))
 612                         break;
 613
 614                 /* get the issued broadcast payload from the socket */
 615
 616                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 617                                                          MAX_BROADCAST_PAYLOAD);
 618                 if (len < 0) {
 619                         fprintf(stderr, "Error reading broadcast payload\n");
 620                         break;
 621                 }
 622
 623                 /* broadcast it to all guys with this protocol index */
 624
 625                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 626
 627                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
 628
 629                                 new_wsi = this->fd_hashtable[n].wsi[m];
 630
 631                                 /* only to clients we are serving to */
 632
 633                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 634                                         continue;
 635
 636                                 /*
 637                                  * never broadcast to non-established
 638                                  * connection
 639                                  */
 640
 641                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 642                                         continue;
 643
 644                                 /*
 645                                  * only broadcast to connections using
 646                                  * the requested protocol
 647                                  */
 648
 649                                 if (new_wsi->protocol->protocol_index !=
 650                                         wsi->protocol_index_for_broadcast_proxy)
 651                                         continue;
 652
 653                                 /* broadcast it to this connection */
 654
 655                                 new_wsi->protocol->callback(this, new_wsi,
 656                                         LWS_CALLBACK_BROADCAST,
 657                                         new_wsi->user_space,
 658                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 659                         }
 660                 }
 661                 break;
 662
 663         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
 664
 665                 /* handle proxy hung up on us */
 666
 667                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 668
 669                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
 670                                 (void *)wsi, pollfd->fd);
 671
 672                         libwebsocket_close_and_free_session(this, wsi,
 673                                                      LWS_CLOSE_STATUS_NOSTATUS);
 674                         return 1;
 675                 }
 676
 677                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
 678                 if (n < 0) {
 679                         libwebsocket_close_and_free_session(this, wsi,
 680                                                      LWS_CLOSE_STATUS_NOSTATUS);
 681                         fprintf(stderr, "ERROR reading from proxy socket\n");
 682                         return 1;
 683                 }
 684
 685                 pkt[13] = '\0';
 686                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
 687                         libwebsocket_close_and_free_session(this, wsi,
 688                                                      LWS_CLOSE_STATUS_NOSTATUS);
 689                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
 690                         return 1;
 691                 }
 692
 693                 /* clear his proxy connection timeout */
 694
 695                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 696
 697                 /* fallthru */
 698
 699         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
 700
 701         #ifdef LWS_OPENSSL_SUPPORT
 702                 if (wsi->use_ssl) {
 703
 704                         wsi->ssl = SSL_new(this->ssl_client_ctx);
 705                         wsi->client_bio = BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 706                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 707
 708                         SSL_set_ex_data(wsi->ssl,
 709                               this->openssl_websocket_private_data_index, this);
 710
 711                         if (SSL_connect(wsi->ssl) <= 0) {
 712                                 fprintf(stderr, "SSL connect error %s\n",
 713                                         ERR_error_string(ERR_get_error(),
 714                                                                   ssl_err_buf));
 715                                 libwebsocket_close_and_free_session(this, wsi,
 716                                                      LWS_CLOSE_STATUS_NOSTATUS);
 717                                 return 1;
 718                         }
 719
 720                         n = SSL_get_verify_result(wsi->ssl);
 721                         if (n != X509_V_OK) && (
 722                                 n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 723                                                            wsi->use_ssl != 2)) {
 724
 725                                 fprintf(stderr, "server's cert didn't "
 726                                                            "look good %d\n", n);
 727                                 libwebsocket_close_and_free_session(this, wsi,
 728                                                      LWS_CLOSE_STATUS_NOSTATUS);
 729                                 return 1;
 730                         }
 731                 } else {
 732                         wsi->ssl = NULL;
 733         #endif
 734
 735
 736         #ifdef LWS_OPENSSL_SUPPORT
 737                 }
 738         #endif
 739
 740                 /*
 741                  * create the random key
 742                  */
 743
 744                 n = read(this->fd_random, hash, 16);
 745                 if (n != 16) {
 746                         fprintf(stderr, "Unable to read from random dev %s\n",
 747                                                         SYSTEM_RANDOM_FILEPATH);
 748                         free(wsi->c_path);
 749                         free(wsi->c_host);
 750                         if (wsi->c_origin)
 751                                 free(wsi->c_origin);
 752                         if (wsi->c_protocol)
 753                                 free(wsi->c_protocol);
 754                         libwebsocket_close_and_free_session(this, wsi,
 755                                                      LWS_CLOSE_STATUS_NOSTATUS);
 756                         return 1;
 757                 }
 758
 759                 lws_b64_encode_string(hash, 16, wsi->key_b64,
 760                                                            sizeof wsi->key_b64);
 761
 762                 /*
 763                  * 04 example client handshake
 764                  *
 765                  * GET /chat HTTP/1.1
 766                  * Host: server.example.com
 767                  * Upgrade: websocket
 768                  * Connection: Upgrade
 769                  * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 770                  * Sec-WebSocket-Origin: http://example.com
 771                  * Sec-WebSocket-Protocol: chat, superchat
 772                  * Sec-WebSocket-Version: 4
 773                  */
 774
 775                 p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 776                 p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 777                 p += sprintf(p, "Upgrade: websocket\x0d\x0a");
 778                 p += sprintf(p, "Connection: Upgrade\x0d\x0a"
 779                                         "Sec-WebSocket-Key: ");
 780                 strcpy(p, wsi->key_b64);
 781                 p += strlen(wsi->key_b64);
 782                 p += sprintf(p, "\x0d\x0a");
 783                 if (wsi->c_origin)
 784                         p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
 785                                                                  wsi->c_origin);
 786                 if (wsi->c_protocol)
 787                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 788                                                                wsi->c_protocol);
 789                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a",
 790                                                        wsi->ietf_spec_revision);
 791
 792                 /* done with these now */
 793
 794                 free(wsi->c_path);
 795                 free(wsi->c_host);
 796                 if (wsi->c_origin)
 797                         free(wsi->c_origin);
 798
 799                 /* prepare the expected server accept response */
 800
 801                 strcpy((char *)buf, wsi->key_b64);
 802                 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 803
 804                 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 805
 806                 lws_b64_encode_string(hash, 20,
 807                                 wsi->initial_handshake_hash_base64,
 808                                      sizeof wsi->initial_handshake_hash_base64);
 809
 810                 /* send our request to the server */
 811
 812         #ifdef LWS_OPENSSL_SUPPORT
 813                 if (wsi->use_ssl)
 814                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 815                 else
 816         #endif
 817                         n = send(wsi->sock, pkt, p - pkt, 0);
 818
 819                 if (n < 0) {
 820                         fprintf(stderr, "ERROR writing to client socket\n");
 821                         libwebsocket_close_and_free_session(this, wsi,
 822                                                      LWS_CLOSE_STATUS_NOSTATUS);
 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->ietf_spec_revision == 4) ||
 891                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
 892                                                      wsi->c_protocol != NULL)) {
 893                         fprintf(stderr, "libwebsocket_client_handshake "
 894                                                 "missing required header(s)\n");
 895                         pkt[len] = '\0';
 896                         fprintf(stderr, "%s", pkt);
 897                         goto bail3;
 898                 }
 899
 900                 /*
 901                  * Everything seems to be there, now take a closer look at what
 902                  * is in each header
 903                  */
 904
 905                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 906                 if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
 907                                                    "101 switching protocols")) {
 908                         fprintf(stderr, "libwebsocket_client_handshake "
 909                                         "server sent bad HTTP response '%s'\n",
 910                                          wsi->utf8_token[WSI_TOKEN_HTTP].token);
 911                         goto bail3;
 912                 }
 913
 914                 strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 915                 if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 916                                                                  "websocket")) {
 917                         fprintf(stderr, "libwebsocket_client_handshake server "
 918                                         "sent bad Upgrade header '%s'\n",
 919                                       wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 920                         goto bail3;
 921                 }
 922
 923                 strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 924                 if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 925                                                                    "upgrade")) {
 926                         fprintf(stderr, "libwebsocket_client_handshake server "
 927                                         "sent bad Connection hdr '%s'\n",
 928                                    wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 929                         goto bail3;
 930                 }
 931
 932
 933                 pc = wsi->c_protocol;
 934
 935                 /*
 936                  * confirm the protocol the server wants to talk was in the list
 937                  * of protocols we offered
 938                  */
 939
 940                 if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 941
 942                         /*
 943                          * no protocol name to work from,
 944                          * default to first protocol
 945                          */
 946                         wsi->protocol = &this->protocols[0];
 947
 948                         free(wsi->c_protocol);
 949
 950                         goto check_accept;
 951                 }
 952
 953                 while (*pc && !okay) {
 954                         if ((!strncmp(pc,
 955                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 956                            wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 957                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 958                    pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 959                                 okay = 1;
 960                                 continue;
 961                         }
 962                         while (*pc && *pc != ',')
 963                                 pc++;
 964                         while (*pc && *pc != ' ')
 965                                 pc++;
 966                 }
 967
 968                 /* done with him now */
 969
 970                 if (wsi->c_protocol)
 971                         free(wsi->c_protocol);
 972
 973
 974                 if (!okay) {
 975                         fprintf(stderr, "libwebsocket_client_handshake server "
 976                                                 "sent bad protocol '%s'\n",
 977                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 978                         goto bail2;
 979                 }
 980
 981                 /*
 982                  * identify the selected protocol struct and set it
 983                  */
 984                 n = 0;
 985                 wsi->protocol = NULL;
 986                 while (this->protocols[n].callback) {
 987                         if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 988                                                this->protocols[n].name) == 0)
 989                                 wsi->protocol = &this->protocols[n];
 990                         n++;
 991                 }
 992
 993                 if (wsi->protocol == NULL) {
 994                         fprintf(stderr, "libwebsocket_client_handshake server "
 995                                         "requested protocol '%s', which we "
 996                                         "said we supported but we don't!\n",
 997                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 998                         goto bail2;
 999                 }
1000
1001         check_accept:
1002                 /*
1003                  * Confirm his accept token is the one we precomputed
1004                  */
1005
1006                 if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1007                                           wsi->initial_handshake_hash_base64)) {
1008                         fprintf(stderr, "libwebsocket_client_handshake server "
1009                                 "sent bad ACCEPT '%s' vs computed '%s'\n",
1010                                 wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1011                                             wsi->initial_handshake_hash_base64);
1012                         goto bail2;
1013                 }
1014
1015                 if (wsi->ietf_spec_revision == 4) {
1016                         /*
1017                          * Calculate the 04 masking key to use when
1018                          * sending data to server
1019                          */
1020
1021                         strcpy((char *)buf, wsi->key_b64);
1022                         p = (char *)buf + strlen(wsi->key_b64);
1023                         strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1024                         p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1025                         strcpy(p, magic_websocket_04_masking_guid);
1026                         SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1027                 }
1028
1029                 /* allocate the per-connection user memory (if any) */
1030
1031                 if (wsi->protocol->per_session_data_size) {
1032                         wsi->user_space = malloc(
1033                                           wsi->protocol->per_session_data_size);
1034                         if (wsi->user_space  == NULL) {
1035                                 fprintf(stderr, "Out of memory for "
1036                                                            "conn user space\n");
1037                                 goto bail2;
1038                         }
1039                 } else
1040                         wsi->user_space = NULL;
1041
1042                 /* clear his proxy connection timeout */
1043
1044                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1045
1046                 /* mark him as being alive */
1047
1048                 wsi->state = WSI_STATE_ESTABLISHED;
1049                 wsi->mode = LWS_CONNMODE_WS_CLIENT;
1050
1051                 fprintf(stderr, "handshake OK for protocol %s\n",
1052                                                            wsi->protocol->name);
1053
1054                 /* call him back to inform him he is up */
1055
1056                 wsi->protocol->callback(this, wsi,
1057                                  LWS_CALLBACK_CLIENT_ESTABLISHED,
1058                                  wsi->user_space,
1059                                  NULL, 0);
1060
1061                 break;
1062
1063 bail3:
1064                 if (wsi->c_protocol)
1065                         free(wsi->c_protocol);
1066
1067 bail2:
1068                 libwebsocket_close_and_free_session(this, wsi,
1069                                                      LWS_CLOSE_STATUS_NOSTATUS);
1070                 return 1;
1071
1072
1073         case LWS_CONNMODE_WS_SERVING:
1074         case LWS_CONNMODE_WS_CLIENT:
1075
1076                 /* handle session socket closed */
1077
1078                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1079
1080                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1081                                 (void *)wsi, pollfd->fd);
1082
1083                         libwebsocket_close_and_free_session(this, wsi,
1084                                                      LWS_CLOSE_STATUS_NOSTATUS);
1085                         return 1;
1086                 }
1087
1088                 /* the guy requested a callback when it was OK to write */
1089
1090                 if (pollfd->revents & POLLOUT) {
1091
1092                         pollfd->events &= ~POLLOUT;
1093
1094                         /* external POLL support via protocol 0 */
1095                         this->protocols[0].callback(this, wsi,
1096                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1097                                 (void *)(long)wsi->sock, NULL, POLLOUT);
1098
1099                         wsi->protocol->callback(this, wsi,
1100                                 LWS_CALLBACK_CLIENT_WRITEABLE,
1101                                 wsi->user_space,
1102                                 NULL, 0);
1103                 }
1104
1105                 /* any incoming data ready? */
1106
1107                 if (!(pollfd->revents & POLLIN))
1108                         break;
1109
1110 #ifdef LWS_OPENSSL_SUPPORT
1111                 if (wsi->ssl)
1112                         n = SSL_read(wsi->ssl, buf, sizeof buf);
1113                 else
1114 #endif
1115                         n = recv(pollfd->fd, buf, sizeof buf, 0);
1116
1117                 if (n < 0) {
1118                         fprintf(stderr, "Socket read returned %d\n", n);
1119                         break;
1120                 }
1121                 if (!n) {
1122                         libwebsocket_close_and_free_session(this, wsi,
1123                                                      LWS_CLOSE_STATUS_NOSTATUS);
1124                         return 1;
1125                 }
1126
1127                 /* service incoming data */
1128
1129                 n = libwebsocket_read(this, wsi, buf, n);
1130                 if (n >= 0)
1131                         break;
1132
1133                 /* we closed wsi */
1134
1135                 return 1;
1136         }
1137
1138         return 0;
1139 }
1140
1141
1142 /**
1143  * libwebsocket_context_destroy() - Destroy the websocket context
1144  * @this:       Websocket context
1145  *
1146  *      This function closes any active connections and then frees the
1147  *      context.  After calling this, any further use of the context is
1148  *      undefined.
1149  */
1150 void
1151 libwebsocket_context_destroy(struct libwebsocket_context *this)
1152 {
1153         int n;
1154         int m;
1155         struct libwebsocket *wsi;
1156
1157         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1158                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1159                         wsi = this->fd_hashtable[n].wsi[m];
1160                         libwebsocket_close_and_free_session(this, wsi,
1161                                                     LWS_CLOSE_STATUS_GOINGAWAY);
1162                 }
1163
1164         close(this->fd_random);
1165
1166 #ifdef LWS_OPENSSL_SUPPORT
1167         if (this->ssl_ctx)
1168                 SSL_CTX_free(this->ssl_ctx);
1169         if (this->ssl_client_ctx)
1170                 SSL_CTX_free(this->ssl_client_ctx);
1171 #endif
1172
1173         free(this);
1174 }
1175
1176 /**
1177  * libwebsocket_service() - Service any pending websocket activity
1178  * @this:       Websocket context
1179  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
1180  *              service otherwise block and service immediately, returning
1181  *              after the timeout if nothing needed service.
1182  *
1183  *      This function deals with any pending websocket traffic, for three
1184  *      kinds of event.  It handles these events on both server and client
1185  *      types of connection the same.
1186  *
1187  *      1) Accept new connections to our context's server
1188  *
1189  *      2) Perform pending broadcast writes initiated from other forked
1190  *         processes (effectively serializing asynchronous broadcasts)
1191  *
1192  *      3) Call the receive callback for incoming frame data received by
1193  *          server or client connections.
1194  *
1195  *      You need to call this service function periodically to all the above
1196  *      functions to happen; if your application is single-threaded you can
1197  *      just call it in your main event loop.
1198  *
1199  *      Alternatively you can fork a new process that asynchronously handles
1200  *      calling this service in a loop.  In that case you are happy if this
1201  *      call blocks your thread until it needs to take care of something and
1202  *      would call it with a large nonzero timeout.  Your loop then takes no
1203  *      CPU while there is nothing happening.
1204  *
1205  *      If you are calling it in a single-threaded app, you don't want it to
1206  *      wait around blocking other things in your loop from happening, so you
1207  *      would call it with a timeout_ms of 0, so it returns immediately if
1208  *      nothing is pending, or as soon as it services whatever was pending.
1209  */
1210
1211
1212 int
1213 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
1214 {
1215         int n;
1216
1217         /* stay dead once we are dead */
1218
1219         if (this == NULL)
1220                 return 1;
1221
1222         /* wait for something to need service */
1223
1224         n = poll(this->fds, this->fds_count, timeout_ms);
1225         if (n == 0) /* poll timeout */
1226                 return 0;
1227
1228         if (n < 0) {
1229                 /*
1230                 fprintf(stderr, "Listen Socket dead\n");
1231                 */
1232                 return 1;
1233         }
1234
1235         /* handle accept on listening socket? */
1236
1237         for (n = 0; n < this->fds_count; n++)
1238                 if (this->fds[n].revents)
1239                         libwebsocket_service_fd(this, &this->fds[n]);
1240
1241         return 0;
1242 }
1243
1244 /**
1245  * libwebsocket_callback_on_writable() - Request a callback when this socket
1246  *                                       becomes able to be written to without
1247  *                                       blocking
1248  *
1249  * @this:       libwebsockets context
1250  * @wsi:        Websocket connection instance to get callback for
1251  */
1252
1253 int
1254 libwebsocket_callback_on_writable(struct libwebsocket_context *this,
1255                                                        struct libwebsocket *wsi)
1256 {
1257         int n;
1258
1259         for (n = 0; n < this->fds_count; n++)
1260                 if (this->fds[n].fd == wsi->sock) {
1261                         this->fds[n].events |= POLLOUT;
1262                         n = this->fds_count;
1263                 }
1264
1265         /* external POLL support via protocol 0 */
1266         this->protocols[0].callback(this, wsi,
1267                 LWS_CALLBACK_SET_MODE_POLL_FD,
1268                 (void *)(long)wsi->sock, NULL, POLLOUT);
1269
1270         return 1;
1271 }
1272
1273 /**
1274  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
1275  *                      all connections using the given protocol when it
1276  *                      becomes possible to write to each socket without
1277  *                      blocking in turn.
1278  *
1279  * @protocol:   Protocol whose connections will get callbacks
1280  */
1281
1282 int
1283 libwebsocket_callback_on_writable_all_protocol(
1284                                   const struct libwebsocket_protocols *protocol)
1285 {
1286         struct libwebsocket_context *this = protocol->owning_server;
1287         int n;
1288         int m;
1289         struct libwebsocket *wsi;
1290
1291         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1292
1293                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1294
1295                         wsi = this->fd_hashtable[n].wsi[m];
1296
1297                         if (wsi->protocol == protocol)
1298                                 libwebsocket_callback_on_writable(this, wsi);
1299                 }
1300         }
1301
1302         return 0;
1303 }
1304
1305 /**
1306  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
1307  *
1308  * You will not need this unless you are doing something special
1309  *
1310  * @wsi:        Websocket connection instance
1311  * @reason:     timeout reason
1312  * @secs:       how many seconds
1313  */
1314
1315 void
1316 libwebsocket_set_timeout(struct libwebsocket *wsi,
1317                                           enum pending_timeout reason, int secs)
1318 {
1319         struct timeval tv;
1320
1321         gettimeofday(&tv, NULL);
1322
1323         wsi->pending_timeout_limit = tv.tv_sec + secs;
1324         wsi->pending_timeout = reason;
1325 }
1326
1327
1328 /**
1329  * libwebsocket_get_socket_fd() - returns the socket file descriptor
1330  *
1331  * You will not need this unless you are doing something special
1332  *
1333  * @wsi:        Websocket connection instance
1334  */
1335
1336 int
1337 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
1338 {
1339         return wsi->sock;
1340 }
1341
1342 /**
1343  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
1344  *                              receieved packets.
1345  *
1346  * If the output side of a server process becomes choked, this allows flow
1347  * control for the input side.
1348  *
1349  * @wsi:        Websocket connection instance to get callback for
1350  * @enable:     0 = disable read servicing for this connection, 1 = enable
1351  */
1352
1353 int
1354 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
1355 {
1356         struct libwebsocket_context *this = wsi->protocol->owning_server;
1357         int n;
1358
1359         for (n = 0; n < this->fds_count; n++)
1360                 if (this->fds[n].fd == wsi->sock) {
1361                         if (enable)
1362                                 this->fds[n].events |= POLLIN;
1363                         else
1364                                 this->fds[n].events &= ~POLLIN;
1365
1366                         return 0;
1367                 }
1368
1369         if (enable)
1370                 /* external POLL support via protocol 0 */
1371                 this->protocols[0].callback(this, wsi,
1372                         LWS_CALLBACK_SET_MODE_POLL_FD,
1373                         (void *)(long)wsi->sock, NULL, POLLIN);
1374         else
1375                 /* external POLL support via protocol 0 */
1376                 this->protocols[0].callback(this, wsi,
1377                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1378                         (void *)(long)wsi->sock, NULL, POLLIN);
1379
1380
1381         fprintf(stderr, "libwebsocket_callback_on_writable "
1382                                                      "unable to find socket\n");
1383         return 1;
1384 }
1385
1386 /**
1387  * libwebsocket_canonical_hostname() - returns this host's hostname
1388  *
1389  * This is typically used by client code to fill in the host parameter
1390  * when making a client connection.  You can only call it after the context
1391  * has been created.
1392  *
1393  * @this:       Websocket context
1394  */
1395
1396
1397 extern const char *
1398 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
1399 {
1400         return (const char *)this->canonical_hostname;
1401 }
1402
1403
1404 static void sigpipe_handler(int x)
1405 {
1406 }
1407
1408 #ifdef LWS_OPENSSL_SUPPORT
1409 static int
1410 OpenSSL_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
1411 {
1412
1413         SSL *ssl;
1414         int n;
1415 //      struct libwebsocket_context *this;
1416
1417         ssl = X509_STORE_CTX_get_ex_data(x509_ctx,
1418                 SSL_get_ex_data_X509_STORE_CTX_idx());
1419
1420         /*
1421          * !!! can't get this->openssl_websocket_private_data_index
1422          * can't store as a static either
1423          */
1424 //      this = SSL_get_ex_data(ssl, this->openssl_websocket_private_data_index);
1425
1426         n = this->protocols[0].callback(NULL, NULL,
1427                 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
1428                                                    x509_ctx, ssl, preverify_ok);
1429
1430         /* convert return code from 0 = OK to 1 = OK */
1431
1432         if (!n)
1433                 n = 1;
1434         else
1435                 n = 0;
1436
1437         return n;
1438 }
1439 #endif
1440
1441
1442 /**
1443  * libwebsocket_create_context() - Create the websocket handler
1444  * @port:       Port to listen on... you can use 0 to suppress listening on
1445  *              any port, that's what you want if you are not running a
1446  *              websocket server at all but just using it as a client
1447  * @interface:  NULL to bind the listen socket to all interfaces, or the
1448  *              interface name, eg, "eth2"
1449  * @protocols:  Array of structures listing supported protocols and a protocol-
1450  *              specific callback for each one.  The list is ended with an
1451  *              entry that has a NULL callback pointer.
1452  *              It's not const because we write the owning_server member
1453  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
1454  *                      to listen using SSL, set to the filepath to fetch the
1455  *                      server cert from, otherwise NULL for unencrypted
1456  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
1457  *                      else ignored
1458  * @gid:        group id to change to after setting listen socket, or -1.
1459  * @uid:        user id to change to after setting listen socket, or -1.
1460  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
1461  *
1462  *      This function creates the listening socket and takes care
1463  *      of all initialization in one step.
1464  *
1465  *      After initialization, it returns a struct libwebsocket_context * that
1466  *      represents this server.  After calling, user code needs to take care
1467  *      of calling libwebsocket_service() with the context pointer to get the
1468  *      server's sockets serviced.  This can be done in the same process context
1469  *      or a forked process, or another thread,
1470  *
1471  *      The protocol callback functions are called for a handful of events
1472  *      including http requests coming in, websocket connections becoming
1473  *      established, and data arriving; it's also called periodically to allow
1474  *      async transmission.
1475  *
1476  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
1477  *      at that time websocket protocol has not been negotiated.  Other
1478  *      protocols after the first one never see any HTTP callack activity.
1479  *
1480  *      The server created is a simple http server by default; part of the
1481  *      websocket standard is upgrading this http connection to a websocket one.
1482  *
1483  *      This allows the same server to provide files like scripts and favicon /
1484  *      images or whatever over http and dynamic data over websockets all in
1485  *      one place; they're all handled in the user callback.
1486  */
1487
1488 struct libwebsocket_context *
1489 libwebsocket_create_context(int port, const char *interface,
1490                                struct libwebsocket_protocols *protocols,
1491                                const char *ssl_cert_filepath,
1492                                const char *ssl_private_key_filepath,
1493                                int gid, int uid, unsigned int options)
1494 {
1495         int n;
1496         int sockfd = 0;
1497         int fd;
1498         struct sockaddr_in serv_addr, cli_addr;
1499         int opt = 1;
1500         struct libwebsocket_context *this = NULL;
1501         unsigned int slen;
1502         char *p;
1503         char hostname[1024];
1504         struct hostent *he;
1505         struct libwebsocket *wsi;
1506
1507 #ifdef LWS_OPENSSL_SUPPORT
1508         SSL_METHOD *method;
1509         char ssl_err_buf[512];
1510 #endif
1511
1512         this = malloc(sizeof(struct libwebsocket_context));
1513         if (!this) {
1514                 fprintf(stderr, "No memory for websocket context\n");
1515                 return NULL;
1516         }
1517         this->protocols = protocols;
1518         this->listen_port = port;
1519         this->http_proxy_port = 0;
1520         this->http_proxy_address[0] = '\0';
1521         this->options = options;
1522         this->fds_count = 0;
1523
1524         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
1525         if (this->fd_random < 0) {
1526                 fprintf(stderr, "Unable to open random device %s %d\n",
1527                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
1528                 return NULL;
1529         }
1530
1531         /* find canonical hostname */
1532
1533         hostname[(sizeof hostname) - 1] = '\0';
1534         gethostname(hostname, (sizeof hostname) - 1);
1535         he = gethostbyname(hostname);
1536         if (he) {
1537                 strncpy(this->canonical_hostname, he->h_name,
1538                                            sizeof this->canonical_hostname - 1);
1539                 this->canonical_hostname[sizeof this->canonical_hostname - 1] =
1540                                                                            '\0';
1541         } else
1542                 strncpy(this->canonical_hostname, hostname,
1543                                            sizeof this->canonical_hostname - 1);
1544
1545         /* split the proxy ads:port if given */
1546
1547         p = getenv("http_proxy");
1548         if (p) {
1549                 strncpy(this->http_proxy_address, p,
1550                                            sizeof this->http_proxy_address - 1);
1551                 this->http_proxy_address[
1552                                     sizeof this->http_proxy_address - 1] = '\0';
1553
1554                 p = strchr(this->http_proxy_address, ':');
1555                 if (p == NULL) {
1556                         fprintf(stderr, "http_proxy needs to be ads:port\n");
1557                         return NULL;
1558                 }
1559                 *p = '\0';
1560                 this->http_proxy_port = atoi(p + 1);
1561
1562                 fprintf(stderr, "Using proxy %s:%u\n",
1563                                 this->http_proxy_address,
1564                                                         this->http_proxy_port);
1565         }
1566
1567         if (port) {
1568
1569 #ifdef LWS_OPENSSL_SUPPORT
1570                 this->use_ssl = ssl_cert_filepath != NULL &&
1571                                                ssl_private_key_filepath != NULL;
1572                 if (this->use_ssl)
1573                         fprintf(stderr, " Compiled with SSL support, "
1574                                                                   "using it\n");
1575                 else
1576                         fprintf(stderr, " Compiled with SSL support, "
1577                                                               "not using it\n");
1578
1579 #else
1580                 if (ssl_cert_filepath != NULL &&
1581                                              ssl_private_key_filepath != NULL) {
1582                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
1583                         return NULL;
1584                 }
1585                 fprintf(stderr, " Compiled without SSL support, "
1586                                                        "serving unencrypted\n");
1587 #endif
1588         }
1589
1590         /* ignore SIGPIPE */
1591
1592         signal(SIGPIPE, sigpipe_handler);
1593
1594
1595 #ifdef LWS_OPENSSL_SUPPORT
1596
1597         /* basic openssl init */
1598
1599         SSL_library_init();
1600
1601         OpenSSL_add_all_algorithms();
1602         SSL_load_error_strings();
1603
1604         this->openssl_websocket_private_data_index =
1605                 SSL_get_ex_new_index(0, "libwebsockets", NULL, NULL, NULL);
1606
1607         /*
1608          * Firefox insists on SSLv23 not SSLv3
1609          * Konq disables SSLv2 by default now, SSLv23 works
1610          */
1611
1612         method = (SSL_METHOD *)SSLv23_server_method();
1613         if (!method) {
1614                 fprintf(stderr, "problem creating ssl method: %s\n",
1615                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1616                 return NULL;
1617         }
1618         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
1619         if (!this->ssl_ctx) {
1620                 fprintf(stderr, "problem creating ssl context: %s\n",
1621                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1622                 return NULL;
1623         }
1624
1625         /* client context */
1626
1627         method = (SSL_METHOD *)SSLv23_client_method();
1628         if (!method) {
1629                 fprintf(stderr, "problem creating ssl method: %s\n",
1630                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1631                 return NULL;
1632         }
1633         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
1634         if (!this->ssl_client_ctx) {
1635                 fprintf(stderr, "problem creating ssl context: %s\n",
1636                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1637                 return NULL;
1638         }
1639
1640
1641         /* openssl init for cert verification (used with client sockets) */
1642
1643         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
1644                                                     LWS_OPENSSL_CLIENT_CERTS)) {
1645                 fprintf(stderr, "Unable to load SSL Client certs from %s "
1646                         "(set by --with-client-cert-dir= in configure) -- "
1647                         " client ssl isn't going to work",
1648                                                       LWS_OPENSSL_CLIENT_CERTS);
1649         }
1650
1651         /*
1652          * callback allowing user code to load extra verification certs
1653          * helping the client to verify server identity
1654          */
1655
1656         this->protocols[0].callback(this, NULL,
1657                 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
1658                 this->ssl_client_ctx, NULL, 0);
1659
1660         /* as a server, are we requiring clients to identify themselves? */
1661
1662         if (options & LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT) {
1663
1664                 /* absolutely require the client cert */
1665
1666                 SSL_CTX_set_verify(this->ssl_ctx,
1667                        SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
1668                                                        OpenSSL_verify_callback);
1669
1670                 /*
1671                  * give user code a chance to load certs into the server
1672                  * allowing it to verify incoming client certs
1673                  */
1674
1675                 this->protocols[0].callback(this, NULL,
1676                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
1677                                                         this->ssl_ctx, NULL, 0);
1678         }
1679
1680         if (this->use_ssl) {
1681
1682                 /* openssl init for server sockets */
1683
1684                 /* set the local certificate from CertFile */
1685                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
1686                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
1687                 if (n != 1) {
1688                         fprintf(stderr, "problem getting cert '%s': %s\n",
1689                                 ssl_cert_filepath,
1690                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1691                         return NULL;
1692                 }
1693                 /* set the private key from KeyFile */
1694                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
1695                                                 ssl_private_key_filepath,
1696                                                        SSL_FILETYPE_PEM) != 1) {
1697                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
1698                                                 ssl_private_key_filepath,
1699                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1700                         return NULL;
1701                 }
1702                 /* verify private key */
1703                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
1704                         fprintf(stderr, "Private SSL key doesn't match cert\n");
1705                         return NULL;
1706                 }
1707
1708                 /* SSL is happy and has a cert it's content with */
1709         }
1710 #endif
1711
1712         /* selftest */
1713
1714         if (lws_b64_selftest())
1715                 return NULL;
1716
1717         /* fd hashtable init */
1718
1719         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1720                 this->fd_hashtable[n].length = 0;
1721
1722         /* set up our external listening socket we serve on */
1723
1724         if (port) {
1725
1726                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1727                 if (sockfd < 0) {
1728                         fprintf(stderr, "ERROR opening socket");
1729                         return NULL;
1730                 }
1731
1732                 /* allow us to restart even if old sockets in TIME_WAIT */
1733                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1734
1735                 bzero((char *) &serv_addr, sizeof(serv_addr));
1736                 serv_addr.sin_family = AF_INET;
1737                 if (interface == NULL)
1738                         serv_addr.sin_addr.s_addr = INADDR_ANY;
1739                 else
1740                         interface_to_sa(interface, &serv_addr,
1741                                                 sizeof(serv_addr));
1742                 serv_addr.sin_port = htons(port);
1743
1744                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
1745                                                              sizeof(serv_addr));
1746                 if (n < 0) {
1747                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1748                                                                 port, n, errno);
1749                         return NULL;
1750                 }
1751
1752                 wsi = malloc(sizeof(struct libwebsocket));
1753                 memset(wsi, 0, sizeof (struct libwebsocket));
1754                 wsi->sock = sockfd;
1755                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
1756                 insert_wsi(this, wsi);
1757
1758                 listen(sockfd, 5);
1759                 fprintf(stderr, " Listening on port %d\n", port);
1760
1761                 /* list in the internal poll array */
1762
1763                 this->fds[this->fds_count].fd = sockfd;
1764                 this->fds[this->fds_count++].events = POLLIN;
1765
1766                 /* external POLL support via protocol 0 */
1767                 this->protocols[0].callback(this, wsi,
1768                         LWS_CALLBACK_ADD_POLL_FD,
1769                         (void *)(long)sockfd, NULL, POLLIN);
1770
1771         }
1772
1773         /* drop any root privs for this process */
1774
1775         if (gid != -1)
1776                 if (setgid(gid))
1777                         fprintf(stderr, "setgid: %s\n", strerror(errno));
1778         if (uid != -1)
1779                 if (setuid(uid))
1780                         fprintf(stderr, "setuid: %s\n", strerror(errno));
1781
1782
1783         /* set up our internal broadcast trigger sockets per-protocol */
1784
1785         for (this->count_protocols = 0;
1786                         protocols[this->count_protocols].callback;
1787                                                       this->count_protocols++) {
1788                 protocols[this->count_protocols].owning_server = this;
1789                 protocols[this->count_protocols].protocol_index =
1790                                                           this->count_protocols;
1791
1792                 fd = socket(AF_INET, SOCK_STREAM, 0);
1793                 if (fd < 0) {
1794                         fprintf(stderr, "ERROR opening socket");
1795                         return NULL;
1796                 }
1797
1798                 /* allow us to restart even if old sockets in TIME_WAIT */
1799                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1800
1801                 bzero((char *) &serv_addr, sizeof(serv_addr));
1802                 serv_addr.sin_family = AF_INET;
1803                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1804                 serv_addr.sin_port = 0; /* pick the port for us */
1805
1806                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
1807                 if (n < 0) {
1808                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1809                                                                 port, n, errno);
1810                         return NULL;
1811                 }
1812
1813                 slen = sizeof cli_addr;
1814                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
1815                 if (n < 0) {
1816                         fprintf(stderr, "getsockname failed\n");
1817                         return NULL;
1818                 }
1819                 protocols[this->count_protocols].broadcast_socket_port =
1820                                                        ntohs(cli_addr.sin_port);
1821                 listen(fd, 5);
1822
1823                 debug("  Protocol %s broadcast socket %d\n",
1824                                 protocols[this->count_protocols].name,
1825                                                       ntohs(cli_addr.sin_port));
1826
1827                 /* dummy wsi per broadcast proxy socket */
1828
1829                 wsi = malloc(sizeof(struct libwebsocket));
1830                 memset(wsi, 0, sizeof (struct libwebsocket));
1831                 wsi->sock = fd;
1832                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
1833                 /* note which protocol we are proxying */
1834                 wsi->protocol_index_for_broadcast_proxy = this->count_protocols;
1835                 insert_wsi(this, wsi);
1836
1837                 /* list in internal poll array */
1838
1839                 this->fds[this->fds_count].fd = fd;
1840                 this->fds[this->fds_count].events = POLLIN;
1841                 this->fds[this->fds_count].revents = 0;
1842                 this->fds_count++;
1843
1844                 /* external POLL support via protocol 0 */
1845                 this->protocols[0].callback(this, wsi,
1846                         LWS_CALLBACK_ADD_POLL_FD,
1847                         (void *)(long)fd, NULL, POLLIN);
1848         }
1849
1850         return this;
1851 }
1852
1853
1854 #ifndef LWS_NO_FORK
1855
1856 /**
1857  * libwebsockets_fork_service_loop() - Optional helper function forks off
1858  *                                a process for the websocket server loop.
1859  *                              You don't have to use this but if not, you
1860  *                              have to make sure you are calling
1861  *                              libwebsocket_service periodically to service
1862  *                              the websocket traffic
1863  * @this:       server context returned by creation function
1864  */
1865
1866 int
1867 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
1868 {
1869         int fd;
1870         struct sockaddr_in cli_addr;
1871         int n;
1872         int p;
1873
1874         n = fork();
1875         if (n < 0)
1876                 return n;
1877
1878         if (!n) {
1879
1880                 /* main process context */
1881
1882                 /*
1883                  * set up the proxy sockets to allow broadcast from
1884                  * service process context
1885                  */
1886
1887                 for (p = 0; p < this->count_protocols; p++) {
1888                         fd = socket(AF_INET, SOCK_STREAM, 0);
1889                         if (fd < 0) {
1890                                 fprintf(stderr, "Unable to create socket\n");
1891                                 return -1;
1892                         }
1893                         cli_addr.sin_family = AF_INET;
1894                         cli_addr.sin_port = htons(
1895                              this->protocols[p].broadcast_socket_port);
1896                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1897                         n = connect(fd, (struct sockaddr *)&cli_addr,
1898                                                                sizeof cli_addr);
1899                         if (n < 0) {
1900                                 fprintf(stderr, "Unable to connect to "
1901                                                 "broadcast socket %d, %s\n",
1902                                                 n, strerror(errno));
1903                                 return -1;
1904                         }
1905
1906                         this->protocols[p].broadcast_socket_user_fd = fd;
1907                 }
1908
1909                 return 0;
1910         }
1911
1912         /* we want a SIGHUP when our parent goes down */
1913         prctl(PR_SET_PDEATHSIG, SIGHUP);
1914
1915         /* in this forked process, sit and service websocket connections */
1916
1917         while (1)
1918                 if (libwebsocket_service(this, 1000))
1919                         return -1;
1920
1921         return 0;
1922 }
1923
1924 #endif
1925
1926 /**
1927  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1928  *                                connection.
1929  * @wsi:        pointer to struct websocket you want to know the protocol of
1930  *
1931  *
1932  *      This is useful to get the protocol to broadcast back to from inside
1933  * the callback.
1934  */
1935
1936 const struct libwebsocket_protocols *
1937 libwebsockets_get_protocol(struct libwebsocket *wsi)
1938 {
1939         return wsi->protocol;
1940 }
1941
1942 /**
1943  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1944  *                                connections of the given protocol.
1945  * @protocol:   pointer to the protocol you will broadcast to all members of
1946  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1947  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1948  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1949  *              case you are calling this function from callback context.
1950  * @len:        length of payload data in buf, starting from buf.
1951  *
1952  *      This function allows bulk sending of a packet to every connection using
1953  * the given protocol.  It does not send the data directly; instead it calls
1954  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1955  * wants to actually send the data for that connection, the callback itself
1956  * should call libwebsocket_write().
1957  *
1958  * libwebsockets_broadcast() can be called from another fork context without
1959  * having to take any care about data visibility between the processes, it'll
1960  * "just work".
1961  */
1962
1963
1964 int
1965 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1966                                                  unsigned char *buf, size_t len)
1967 {
1968         struct libwebsocket_context *this = protocol->owning_server;
1969         int n;
1970         int m;
1971         struct libwebsocket * wsi;
1972
1973         if (!protocol->broadcast_socket_user_fd) {
1974                 /*
1975                  * We are either running unforked / flat, or we are being
1976                  * called from poll thread context
1977                  * eg, from a callback.  In that case don't use sockets for
1978                  * broadcast IPC (since we can't open a socket connection to
1979                  * a socket listening on our own thread) but directly do the
1980                  * send action.
1981                  *
1982                  * Locking is not needed because we are by definition being
1983                  * called in the poll thread context and are serialized.
1984                  */
1985
1986                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1987
1988                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
1989
1990                                 wsi = this->fd_hashtable[n].wsi[m];
1991
1992                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
1993                                         continue;
1994
1995                                 /*
1996                                  * never broadcast to
1997                                  * non-established connections
1998                                  */
1999                                 if (wsi->state != WSI_STATE_ESTABLISHED)
2000                                         continue;
2001
2002                                 /* only broadcast to guys using
2003                                  * requested protocol
2004                                  */
2005                                 if (wsi->protocol != protocol)
2006                                         continue;
2007
2008                                 wsi->protocol->callback(this, wsi,
2009                                          LWS_CALLBACK_BROADCAST,
2010                                          wsi->user_space,
2011                                          buf, len);
2012                         }
2013                 }
2014
2015                 return 0;
2016         }
2017
2018         /*
2019          * We're being called from a different process context than the server
2020          * loop.  Instead of broadcasting directly, we send our
2021          * payload on a socket to do the IPC; the server process will serialize
2022          * the broadcast action in its main poll() loop.
2023          *
2024          * There's one broadcast socket listening for each protocol supported
2025          * set up when the websocket server initializes
2026          */
2027
2028         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
2029
2030         return n;
2031 }