lib/libwebsockets.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23 #include <ifaddrs.h>
  24
  25 /*
  26  * In-place str to lower case
  27  */
  28
  29 static void
  30 strtolower(char *s)
  31 {
  32         while (*s) {
  33                 *s = tolower(*s);
  34                 s++;
  35         }
  36 }
  37
  38 /* file descriptor hash management */
  39
  40 struct libwebsocket *
  41 wsi_from_fd(struct libwebsocket_context *this, int fd)
  42 {
  43         int h = LWS_FD_HASH(fd);
  44         int n = 0;
  45
  46         for (n = 0; n < this->fd_hashtable[h].length; n++)
  47                 if (this->fd_hashtable[h].wsi[n]->sock == fd)
  48                         return this->fd_hashtable[h].wsi[n];
  49
  50         return NULL;
  51 }
  52
  53 int
  54 insert_wsi(struct libwebsocket_context *this, struct libwebsocket *wsi)
  55 {
  56         int h = LWS_FD_HASH(wsi->sock);
  57
  58         if (this->fd_hashtable[h].length == MAX_CLIENTS - 1) {
  59                 fprintf(stderr, "hash table overflow\n");
  60                 return 1;
  61         }
  62
  63         this->fd_hashtable[h].wsi[this->fd_hashtable[h].length++] = wsi;
  64
  65         return 0;
  66 }
  67
  68 int
  69 delete_from_fd(struct libwebsocket_context *this, int fd)
  70 {
  71         int h = LWS_FD_HASH(fd);
  72         int n = 0;
  73
  74         for (n = 0; n < this->fd_hashtable[h].length; n++)
  75                 if (this->fd_hashtable[h].wsi[n]->sock == fd) {
  76                         while (n < this->fd_hashtable[h].length) {
  77                                 this->fd_hashtable[h].wsi[n] =
  78                                                this->fd_hashtable[h].wsi[n + 1];
  79                                 n++;
  80                         }
  81                         this->fd_hashtable[h].length--;
  82
  83                         return 0;
  84                 }
  85
  86         fprintf(stderr, "Failed to find fd %d requested for "
  87                                                    "delete in hashtable\n", fd);
  88         return 1;
  89 }
  90
  91 #ifdef LWS_OPENSSL_SUPPORT
  92 static void
  93 libwebsockets_decode_ssl_error(void)
  94 {
  95         char buf[256];
  96         u_long err;
  97
  98         while ((err = ERR_get_error()) != 0) {
  99                 ERR_error_string_n(err, buf, sizeof(buf));
 100                 fprintf(stderr, "*** %s\n", buf);
 101         }
 102 }
 103 #endif
 104
 105
 106 static int
 107 interface_to_sa(const char* ifname, struct sockaddr_in *addr, size_t addrlen)
 108 {
 109         int rc = -1;
 110         struct ifaddrs *ifr;
 111         struct ifaddrs *ifc;
 112         struct sockaddr_in *sin;
 113
 114         getifaddrs(&ifr);
 115         for (ifc = ifr; ifc != NULL; ifc = ifc->ifa_next) {
 116                 if (strcmp(ifc->ifa_name, ifname))
 117                         continue;
 118                 if (ifc->ifa_addr == NULL)
 119                         continue;
 120                 sin = (struct sockaddr_in *)ifc->ifa_addr;
 121                 if (sin->sin_family != AF_INET)
 122                         continue;
 123                 memcpy(addr, sin, addrlen);
 124                 rc = 0;
 125         }
 126
 127         freeifaddrs(ifr);
 128
 129         return rc;
 130 }
 131
 132 void
 133 libwebsocket_close_and_free_session(struct libwebsocket_context *this,
 134                          struct libwebsocket *wsi, enum lws_close_status reason)
 135 {
 136         int n;
 137         int old_state;
 138         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
 139                                                   LWS_SEND_BUFFER_POST_PADDING];
 140
 141         if (!wsi)
 142                 return;
 143
 144         old_state = wsi->state;
 145
 146         if (old_state == WSI_STATE_DEAD_SOCKET)
 147                 return;
 148
 149         /* remove this fd from wsi mapping hashtable */
 150
 151         delete_from_fd(this, wsi->sock);
 152
 153         /* delete it from the internal poll list if still present */
 154
 155         for (n = 0; n < this->fds_count; n++) {
 156                 if (this->fds[n].fd != wsi->sock)
 157                         continue;
 158                 while (n < this->fds_count - 1) {
 159                         this->fds[n] = this->fds[n + 1];
 160                         n++;
 161                 }
 162                 this->fds_count--;
 163                 /* we only have to deal with one */
 164                 n = this->fds_count;
 165         }
 166
 167         /* remove also from external POLL support via protocol 0 */
 168
 169         this->protocols[0].callback(this, wsi,
 170                     LWS_CALLBACK_DEL_POLL_FD, (void *)(long)wsi->sock, NULL, 0);
 171
 172         wsi->close_reason = reason;
 173
 174         /*
 175          * signal we are closing, libsocket_write will
 176          * add any necessary version-specific stuff.  If the write fails,
 177          * no worries we are closing anyway.  If we didn't initiate this
 178          * close, then our state has been changed to
 179          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this
 180          */
 181
 182         if (old_state == WSI_STATE_ESTABLISHED)
 183                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
 184                                                                LWS_WRITE_CLOSE);
 185
 186         wsi->state = WSI_STATE_DEAD_SOCKET;
 187
 188         /* tell the user it's all over for this guy */
 189
 190         if (wsi->protocol->callback && old_state == WSI_STATE_ESTABLISHED)
 191                 wsi->protocol->callback(this, wsi, LWS_CALLBACK_CLOSED,
 192                                                       wsi->user_space, NULL, 0);
 193
 194         /* free up his allocations */
 195
 196         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 197                 if (wsi->utf8_token[n].token)
 198                         free(wsi->utf8_token[n].token);
 199
 200 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 201
 202 #ifdef LWS_OPENSSL_SUPPORT
 203         if (wsi->ssl) {
 204                 n = SSL_get_fd(wsi->ssl);
 205                 SSL_shutdown(wsi->ssl);
 206                 close(n);
 207                 SSL_free(wsi->ssl);
 208         } else {
 209 #endif
 210                 shutdown(wsi->sock, SHUT_RDWR);
 211                 close(wsi->sock);
 212 #ifdef LWS_OPENSSL_SUPPORT
 213         }
 214 #endif
 215         if (wsi->user_space)
 216                 free(wsi->user_space);
 217
 218         free(wsi);
 219 }
 220
 221 /**
 222  * libwebsockets_hangup_on_client() - Server calls to terminate client
 223  *                                      connection
 224  * @this:       libwebsockets context
 225  * @fd:         Connection socket descriptor
 226  */
 227
 228 void
 229 libwebsockets_hangup_on_client(struct libwebsocket_context *this, int fd)
 230 {
 231         struct libwebsocket *wsi = wsi_from_fd(this, fd);
 232
 233         if (wsi == NULL)
 234                 return;
 235
 236         libwebsocket_close_and_free_session(this, wsi,
 237                                                      LWS_CLOSE_STATUS_NOSTATUS);
 238 }
 239
 240
 241 /**
 242  * libwebsockets_get_peer_addresses() - Get client address information
 243  * @fd:         Connection socket descriptor
 244  * @name:       Buffer to take client address name
 245  * @name_len:   Length of client address name buffer
 246  * @rip:        Buffer to take client address IP qotted quad
 247  * @rip_len:    Length of client address IP buffer
 248  *
 249  *      This function fills in @name and @rip with the name and IP of
 250  *      the client connected with socket descriptor @fd.  Names may be
 251  *      truncated if there is not enough room.  If either cannot be
 252  *      determined, they will be returned as valid zero-length strings.
 253  */
 254
 255 void
 256 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 257                                         char *rip, int rip_len)
 258 {
 259         unsigned int len;
 260         struct sockaddr_in sin;
 261         struct hostent *host;
 262         struct hostent *host1;
 263         char ip[128];
 264         char *p;
 265         int n;
 266
 267         rip[0] = '\0';
 268         name[0] = '\0';
 269
 270         len = sizeof sin;
 271         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 272                 perror("getpeername");
 273                 return;
 274         }
 275
 276         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 277                                                                        AF_INET);
 278         if (host == NULL) {
 279                 perror("gethostbyaddr");
 280                 return;
 281         }
 282
 283         strncpy(name, host->h_name, name_len);
 284         name[name_len - 1] = '\0';
 285
 286         host1 = gethostbyname(host->h_name);
 287         if (host1 == NULL)
 288                 return;
 289         p = (char *)host1;
 290         n = 0;
 291         while (p != NULL) {
 292                 p = host1->h_addr_list[n++];
 293                 if (p == NULL)
 294                         continue;
 295                 if (host1->h_addrtype != AF_INET)
 296                         continue;
 297
 298                 sprintf(ip, "%d.%d.%d.%d",
 299                                 p[0], p[1], p[2], p[3]);
 300                 p = NULL;
 301                 strncpy(rip, ip, rip_len);
 302                 rip[rip_len - 1] = '\0';
 303         }
 304 }
 305
 306 /**
 307  * libwebsocket_service_fd() - Service polled socket with something waiting
 308  * @this:       Websocket context
 309  * @pollfd:     The pollfd entry describing the socket fd and which events
 310  *              happened.
 311  *
 312  *      This function closes any active connections and then frees the
 313  *      context.  After calling this, any further use of the context is
 314  *      undefined.
 315  */
 316
 317 int
 318 libwebsocket_service_fd(struct libwebsocket_context *this,
 319                                                           struct pollfd *pollfd)
 320 {
 321         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
 322                                                   LWS_SEND_BUFFER_POST_PADDING];
 323         struct libwebsocket *wsi;
 324         struct libwebsocket *new_wsi;
 325         int n;
 326         int m;
 327         size_t len;
 328         int accept_fd;
 329         unsigned int clilen;
 330         struct sockaddr_in cli_addr;
 331         struct timeval tv;
 332         static const char magic_websocket_guid[] =
 333                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 334         static const char magic_websocket_04_masking_guid[] =
 335                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 336         char hash[20];
 337         char pkt[1024];
 338         char *p = &pkt[0];
 339         const char *pc;
 340         int okay = 0;
 341 #ifdef LWS_OPENSSL_SUPPORT
 342         char ssl_err_buf[512];
 343 #endif
 344         /*
 345          * you can call us with pollfd = NULL to just allow the once-per-second
 346          * global timeout checks; if less than a second since the last check
 347          * it returns immediately then.
 348          */
 349
 350         gettimeofday(&tv, NULL);
 351
 352         if (this->last_timeout_check_s != tv.tv_sec) {
 353                 this->last_timeout_check_s = tv.tv_sec;
 354
 355                 /* global timeout check once per second */
 356
 357                 for (n = 0; n < this->fds_count; n++) {
 358                         wsi = wsi_from_fd(this, this->fds[n].fd);
 359                         if (!wsi->pending_timeout)
 360                                 continue;
 361
 362                         /*
 363                          * if we went beyond the allowed time, kill the
 364                          * connection
 365                          */
 366
 367                         if (tv.tv_sec > wsi->pending_timeout_limit)
 368                                 libwebsocket_close_and_free_session(this, wsi,
 369                                                      LWS_CLOSE_STATUS_NOSTATUS);
 370                 }
 371         }
 372
 373         /* just here for timeout management? */
 374
 375         if (pollfd == NULL)
 376                 return 0;
 377
 378         /* no, here to service a socket descriptor */
 379
 380         wsi = wsi_from_fd(this, pollfd->fd);
 381
 382         if (wsi == NULL)
 383                 return 1;
 384
 385         switch (wsi->mode) {
 386         case LWS_CONNMODE_SERVER_LISTENER:
 387
 388                 /* pollin means a client has connected to us then */
 389
 390                 if (!pollfd->revents & POLLIN)
 391                         break;
 392
 393                 /* listen socket got an unencrypted connection... */
 394
 395                 clilen = sizeof(cli_addr);
 396                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 397                                                                        &clilen);
 398                 if (accept_fd < 0) {
 399                         fprintf(stderr, "ERROR on accept");
 400                         break;
 401                 }
 402
 403                 if (this->fds_count >= MAX_CLIENTS) {
 404                         fprintf(stderr, "too busy to accept new client\n");
 405                         close(accept_fd);
 406                         break;
 407                 }
 408
 409                 /*
 410                  * look at who we connected to and give user code a chance
 411                  * to reject based on client IP.  There's no protocol selected
 412                  * yet so we issue this to protocols[0]
 413                  */
 414
 415                 if ((this->protocols[0].callback)(this, wsi,
 416                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 417                                              (void*)(long)accept_fd, NULL, 0)) {
 418                         fprintf(stderr, "Callback denied network connection\n");
 419                         close(accept_fd);
 420                         break;
 421                 }
 422
 423                 /* accepting connection to main listener */
 424
 425                 new_wsi = malloc(sizeof(struct libwebsocket));
 426                 if (new_wsi == NULL) {
 427                         fprintf(stderr, "Out of memory for new connection\n");
 428                         break;
 429                 }
 430
 431                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 432                 new_wsi->sock = accept_fd;
 433                 new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
 434
 435 #ifdef LWS_OPENSSL_SUPPORT
 436                 new_wsi->ssl = NULL;
 437
 438                 if (this->use_ssl) {
 439
 440                         new_wsi->ssl = SSL_new(this->ssl_ctx);
 441                         if (new_wsi->ssl == NULL) {
 442                                 fprintf(stderr, "SSL_new failed: %s\n",
 443                                     ERR_error_string(SSL_get_error(
 444                                     new_wsi->ssl, 0), NULL));
 445                                     libwebsockets_decode_ssl_error();
 446                                 free(new_wsi);
 447                                 break;
 448                         }
 449
 450                         SSL_set_fd(new_wsi->ssl, accept_fd);
 451
 452                         n = SSL_accept(new_wsi->ssl);
 453                         if (n != 1) {
 454                                 /*
 455                                  * browsers seem to probe with various
 456                                  * ssl params which fail then retry
 457                                  * and succeed
 458                                  */
 459                                 debug("SSL_accept failed skt %u: %s\n",
 460                                       pollfd->fd,
 461                                       ERR_error_string(SSL_get_error(
 462                                       new_wsi->ssl, n), NULL));
 463                                 SSL_free(
 464                                        new_wsi->ssl);
 465                                 free(new_wsi);
 466                                 break;
 467                         }
 468
 469                         debug("accepted new SSL conn  "
 470                               "port %u on fd=%d SSL ver %s\n",
 471                                 ntohs(cli_addr.sin_port), accept_fd,
 472                                   SSL_get_version(new_wsi->ssl));
 473
 474                 } else
 475 #endif
 476                         debug("accepted new conn  port %u on fd=%d\n",
 477                                           ntohs(cli_addr.sin_port), accept_fd);
 478
 479                 /* intialize the instance struct */
 480
 481                 new_wsi->state = WSI_STATE_HTTP;
 482                 new_wsi->name_buffer_pos = 0;
 483                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 484
 485                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 486                         new_wsi->utf8_token[n].token = NULL;
 487                         new_wsi->utf8_token[n].token_len = 0;
 488                 }
 489
 490                 /*
 491                  * these can only be set once the protocol is known
 492                  * we set an unestablished connection's protocol pointer
 493                  * to the start of the supported list, so it can look
 494                  * for matching ones during the handshake
 495                  */
 496                 new_wsi->protocol = this->protocols;
 497                 new_wsi->user_space = NULL;
 498
 499                 /*
 500                  * Default protocol is 76 / 00
 501                  * After 76, there's a header specified to inform which
 502                  * draft the client wants, when that's seen we modify
 503                  * the individual connection's spec revision accordingly
 504                  */
 505                 new_wsi->ietf_spec_revision = 0;
 506
 507                 insert_wsi(this, new_wsi);
 508
 509                 /*
 510                  * make sure NO events are seen yet on this new socket
 511                  * (otherwise we inherit old fds[client].revents from
 512                  * previous socket there and die mysteriously! )
 513                  */
 514                 this->fds[this->fds_count].revents = 0;
 515
 516                 this->fds[this->fds_count].events = POLLIN;
 517                 this->fds[this->fds_count++].fd = accept_fd;
 518
 519                 /* external POLL support via protocol 0 */
 520                 this->protocols[0].callback(this, new_wsi,
 521                         LWS_CALLBACK_ADD_POLL_FD,
 522                         (void *)(long)accept_fd, NULL, POLLIN);
 523
 524                 break;
 525
 526         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 527
 528                 /* as we are listening, POLLIN means accept() is needed */
 529
 530                 if (!pollfd->revents & POLLIN)
 531                         break;
 532
 533                 /* listen socket got an unencrypted connection... */
 534
 535                 clilen = sizeof(cli_addr);
 536                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 537                                                                        &clilen);
 538                 if (accept_fd < 0) {
 539                         fprintf(stderr, "ERROR on accept");
 540                         break;
 541                 }
 542
 543                 if (this->fds_count >= MAX_CLIENTS) {
 544                         fprintf(stderr, "too busy to accept new broadcast "
 545                                                               "proxy client\n");
 546                         close(accept_fd);
 547                         break;
 548                 }
 549
 550                 /* create a dummy wsi for the connection and add it */
 551
 552                 new_wsi = malloc(sizeof(struct libwebsocket));
 553                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 554                 new_wsi->sock = accept_fd;
 555                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 556                 new_wsi->state = WSI_STATE_ESTABLISHED;
 557                 /* note which protocol we are proxying */
 558                 new_wsi->protocol_index_for_broadcast_proxy =
 559                                         wsi->protocol_index_for_broadcast_proxy;
 560                 insert_wsi(this, new_wsi);
 561
 562                 /* add connected socket to internal poll array */
 563
 564                 this->fds[this->fds_count].revents = 0;
 565                 this->fds[this->fds_count].events = POLLIN;
 566                 this->fds[this->fds_count++].fd = accept_fd;
 567
 568                 /* external POLL support via protocol 0 */
 569                 this->protocols[0].callback(this, new_wsi,
 570                         LWS_CALLBACK_ADD_POLL_FD,
 571                         (void *)(long)accept_fd, NULL, POLLIN);
 572
 573                 break;
 574
 575         case LWS_CONNMODE_BROADCAST_PROXY:
 576
 577                 /* handle session socket closed */
 578
 579                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 580
 581                         debug("Session Socket %p (fd=%d) dead\n",
 582                                 (void *)wsi, pollfd->fd);
 583
 584                         libwebsocket_close_and_free_session(this, wsi,
 585                                                        LWS_CLOSE_STATUS_NORMAL);
 586                         return 1;
 587                 }
 588
 589                 /* the guy requested a callback when it was OK to write */
 590
 591                 if (pollfd->revents & POLLOUT) {
 592
 593                         /* one shot */
 594
 595                         pollfd->events &= ~POLLOUT;
 596
 597                         /* external POLL support via protocol 0 */
 598                         this->protocols[0].callback(this, wsi,
 599                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 600                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 601
 602                         wsi->protocol->callback(this, wsi,
 603                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 604                                 wsi->user_space,
 605                                 NULL, 0);
 606                 }
 607
 608                 /* any incoming data ready? */
 609
 610                 if (!(pollfd->revents & POLLIN))
 611                         break;
 612
 613                 /* get the issued broadcast payload from the socket */
 614
 615                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 616                                                          MAX_BROADCAST_PAYLOAD);
 617                 if (len < 0) {
 618                         fprintf(stderr, "Error reading broadcast payload\n");
 619                         break;
 620                 }
 621
 622                 /* broadcast it to all guys with this protocol index */
 623
 624                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 625
 626                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
 627
 628                                 new_wsi = this->fd_hashtable[n].wsi[m];
 629
 630                                 /* only to clients we are serving to */
 631
 632                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 633                                         continue;
 634
 635                                 /*
 636                                  * never broadcast to non-established
 637                                  * connection
 638                                  */
 639
 640                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 641                                         continue;
 642
 643                                 /*
 644                                  * only broadcast to connections using
 645                                  * the requested protocol
 646                                  */
 647
 648                                 if (new_wsi->protocol->protocol_index !=
 649                                         wsi->protocol_index_for_broadcast_proxy)
 650                                         continue;
 651
 652                                 /* broadcast it to this connection */
 653
 654                                 new_wsi->protocol->callback(this, new_wsi,
 655                                         LWS_CALLBACK_BROADCAST,
 656                                         new_wsi->user_space,
 657                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 658                         }
 659                 }
 660                 break;
 661
 662         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
 663
 664                 /* handle proxy hung up on us */
 665
 666                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 667
 668                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
 669                                 (void *)wsi, pollfd->fd);
 670
 671                         libwebsocket_close_and_free_session(this, wsi,
 672                                                      LWS_CLOSE_STATUS_NOSTATUS);
 673                         return 1;
 674                 }
 675
 676                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
 677                 if (n < 0) {
 678                         libwebsocket_close_and_free_session(this, wsi,
 679                                                      LWS_CLOSE_STATUS_NOSTATUS);
 680                         fprintf(stderr, "ERROR reading from proxy socket\n");
 681                         return 1;
 682                 }
 683
 684                 pkt[13] = '\0';
 685                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
 686                         libwebsocket_close_and_free_session(this, wsi,
 687                                                      LWS_CLOSE_STATUS_NOSTATUS);
 688                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
 689                         return 1;
 690                 }
 691
 692                 /* clear his proxy connection timeout */
 693
 694                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 695
 696                 /* fallthru */
 697
 698         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
 699
 700         #ifdef LWS_OPENSSL_SUPPORT
 701                 if (wsi->use_ssl) {
 702
 703                         wsi->ssl = SSL_new(this->ssl_client_ctx);
 704                         wsi->client_bio = BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 705                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 706
 707                         SSL_set_ex_data(wsi->ssl,
 708                               this->openssl_websocket_private_data_index, this);
 709
 710                         if (SSL_connect(wsi->ssl) <= 0) {
 711                                 fprintf(stderr, "SSL connect error %s\n",
 712                                         ERR_error_string(ERR_get_error(),
 713                                                                   ssl_err_buf));
 714                                 libwebsocket_close_and_free_session(this, wsi,
 715                                                      LWS_CLOSE_STATUS_NOSTATUS);
 716                                 return 1;
 717                         }
 718
 719                         n = SSL_get_verify_result(wsi->ssl);
 720                         if (n != X509_V_OK) && (
 721                                 n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 722                                                            wsi->use_ssl != 2)) {
 723
 724                                 fprintf(stderr, "server's cert didn't "
 725                                                            "look good %d\n", n);
 726                                 libwebsocket_close_and_free_session(this, wsi,
 727                                                      LWS_CLOSE_STATUS_NOSTATUS);
 728                                 return 1;
 729                         }
 730                 } else {
 731                         wsi->ssl = NULL;
 732         #endif
 733
 734
 735         #ifdef LWS_OPENSSL_SUPPORT
 736                 }
 737         #endif
 738
 739                 /*
 740                  * create the random key
 741                  */
 742
 743                 n = read(this->fd_random, hash, 16);
 744                 if (n != 16) {
 745                         fprintf(stderr, "Unable to read from random dev %s\n",
 746                                                         SYSTEM_RANDOM_FILEPATH);
 747                         free(wsi->c_path);
 748                         free(wsi->c_host);
 749                         if (wsi->c_origin)
 750                                 free(wsi->c_origin);
 751                         if (wsi->c_protocol)
 752                                 free(wsi->c_protocol);
 753                         libwebsocket_close_and_free_session(this, wsi,
 754                                                      LWS_CLOSE_STATUS_NOSTATUS);
 755                         return 1;
 756                 }
 757
 758                 lws_b64_encode_string(hash, 16, wsi->key_b64,
 759                                                            sizeof wsi->key_b64);
 760
 761                 /*
 762                  * 04 example client handshake
 763                  *
 764                  * GET /chat HTTP/1.1
 765                  * Host: server.example.com
 766                  * Upgrade: websocket
 767                  * Connection: Upgrade
 768                  * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 769                  * Sec-WebSocket-Origin: http://example.com
 770                  * Sec-WebSocket-Protocol: chat, superchat
 771                  * Sec-WebSocket-Version: 4
 772                  */
 773
 774                 p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 775                 p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 776                 p += sprintf(p, "Upgrade: websocket\x0d\x0a");
 777                 p += sprintf(p, "Connection: Upgrade\x0d\x0a"
 778                                         "Sec-WebSocket-Key: ");
 779                 strcpy(p, wsi->key_b64);
 780                 p += strlen(wsi->key_b64);
 781                 p += sprintf(p, "\x0d\x0a");
 782                 if (wsi->c_origin)
 783                         p += sprintf(p, "Sec-WebSocket-Origin: %s\x0d\x0a",
 784                                                                  wsi->c_origin);
 785                 if (wsi->c_protocol)
 786                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 787                                                                wsi->c_protocol);
 788                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a",
 789                                                        wsi->ietf_spec_revision);
 790
 791                 /* done with these now */
 792
 793                 free(wsi->c_path);
 794                 free(wsi->c_host);
 795                 if (wsi->c_origin)
 796                         free(wsi->c_origin);
 797
 798                 /* prepare the expected server accept response */
 799
 800                 strcpy((char *)buf, wsi->key_b64);
 801                 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 802
 803                 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 804
 805                 lws_b64_encode_string(hash, 20,
 806                                 wsi->initial_handshake_hash_base64,
 807                                      sizeof wsi->initial_handshake_hash_base64);
 808
 809                 /* send our request to the server */
 810
 811         #ifdef LWS_OPENSSL_SUPPORT
 812                 if (wsi->use_ssl)
 813                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 814                 else
 815         #endif
 816                         n = send(wsi->sock, pkt, p - pkt, 0);
 817
 818                 if (n < 0) {
 819                         fprintf(stderr, "ERROR writing to client socket\n");
 820                         libwebsocket_close_and_free_session(this, wsi,
 821                                                      LWS_CLOSE_STATUS_NOSTATUS);
 822                         return 1;
 823                 }
 824
 825                 wsi->parser_state = WSI_TOKEN_NAME_PART;
 826                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 827                 libwebsocket_set_timeout(wsi,
 828                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, 5);
 829
 830                 break;
 831
 832         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 833
 834                 /* handle server hung up on us */
 835
 836                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 837
 838                         fprintf(stderr, "Server connection %p (fd=%d) dead\n",
 839                                 (void *)wsi, pollfd->fd);
 840
 841                         goto bail3;
 842                 }
 843
 844
 845                 /* interpret the server response */
 846
 847                 /*
 848                  *  HTTP/1.1 101 Switching Protocols
 849                  *  Upgrade: websocket
 850                  *  Connection: Upgrade
 851                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 852                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 853                  *  Sec-WebSocket-Protocol: chat
 854                  */
 855
 856         #ifdef LWS_OPENSSL_SUPPORT
 857                 if (wsi->use_ssl)
 858                         len = SSL_read(wsi->ssl, pkt, sizeof pkt);
 859                 else
 860         #endif
 861                         len = recv(wsi->sock, pkt, sizeof pkt, 0);
 862
 863                 if (len < 0) {
 864                         fprintf(stderr,
 865                                   "libwebsocket_client_handshake read error\n");
 866                         goto bail3;
 867                 }
 868
 869                 p = pkt;
 870                 for (n = 0; n < len; n++)
 871                         libwebsocket_parse(wsi, *p++);
 872
 873                 if (wsi->parser_state != WSI_PARSING_COMPLETE) {
 874                         fprintf(stderr, "libwebsocket_client_handshake "
 875                                         "server response ailed parsing\n");
 876                         goto bail3;
 877                 }
 878
 879                 /*
 880                  * well, what the server sent looked reasonable for syntax.
 881                  * Now let's confirm it sent all the necessary headers
 882                  */
 883
 884                  if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 885                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 886                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 887                         !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 888                         (!wsi->utf8_token[WSI_TOKEN_NONCE].token_len &&
 889                                            wsi->ietf_spec_revision == 4) ||
 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                 if (wsi->ietf_spec_revision == 4) {
1015                         /*
1016                          * Calculate the 04 masking key to use when
1017                          * sending data to server
1018                          */
1019
1020                         strcpy((char *)buf, wsi->key_b64);
1021                         p = (char *)buf + strlen(wsi->key_b64);
1022                         strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1023                         p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1024                         strcpy(p, magic_websocket_04_masking_guid);
1025                         SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1026                 }
1027
1028                 /* allocate the per-connection user memory (if any) */
1029
1030                 if (wsi->protocol->per_session_data_size) {
1031                         wsi->user_space = malloc(
1032                                           wsi->protocol->per_session_data_size);
1033                         if (wsi->user_space  == NULL) {
1034                                 fprintf(stderr, "Out of memory for "
1035                                                            "conn user space\n");
1036                                 goto bail2;
1037                         }
1038                 } else
1039                         wsi->user_space = NULL;
1040
1041                 /* clear his proxy connection timeout */
1042
1043                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1044
1045                 /* mark him as being alive */
1046
1047                 wsi->state = WSI_STATE_ESTABLISHED;
1048                 wsi->mode = LWS_CONNMODE_WS_CLIENT;
1049
1050                 fprintf(stderr, "handshake OK for protocol %s\n",
1051                                                            wsi->protocol->name);
1052
1053                 /* call him back to inform him he is up */
1054
1055                 wsi->protocol->callback(this, wsi,
1056                                  LWS_CALLBACK_CLIENT_ESTABLISHED,
1057                                  wsi->user_space,
1058                                  NULL, 0);
1059
1060                 break;
1061
1062 bail3:
1063                 if (wsi->c_protocol)
1064                         free(wsi->c_protocol);
1065
1066 bail2:
1067                 libwebsocket_close_and_free_session(this, wsi,
1068                                                      LWS_CLOSE_STATUS_NOSTATUS);
1069                 return 1;
1070
1071
1072         case LWS_CONNMODE_WS_SERVING:
1073         case LWS_CONNMODE_WS_CLIENT:
1074
1075                 /* handle session socket closed */
1076
1077                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1078
1079                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1080                                 (void *)wsi, pollfd->fd);
1081
1082                         libwebsocket_close_and_free_session(this, wsi,
1083                                                      LWS_CLOSE_STATUS_NOSTATUS);
1084                         return 1;
1085                 }
1086
1087                 /* the guy requested a callback when it was OK to write */
1088
1089                 if (pollfd->revents & POLLOUT) {
1090
1091                         pollfd->events &= ~POLLOUT;
1092
1093                         /* external POLL support via protocol 0 */
1094                         this->protocols[0].callback(this, wsi,
1095                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1096                                 (void *)(long)wsi->sock, NULL, POLLOUT);
1097
1098                         wsi->protocol->callback(this, wsi,
1099                                 LWS_CALLBACK_CLIENT_WRITEABLE,
1100                                 wsi->user_space,
1101                                 NULL, 0);
1102                 }
1103
1104                 /* any incoming data ready? */
1105
1106                 if (!(pollfd->revents & POLLIN))
1107                         break;
1108
1109 #ifdef LWS_OPENSSL_SUPPORT
1110                 if (wsi->ssl)
1111                         n = SSL_read(wsi->ssl, buf, sizeof buf);
1112                 else
1113 #endif
1114                         n = recv(pollfd->fd, buf, sizeof buf, 0);
1115
1116                 if (n < 0) {
1117                         fprintf(stderr, "Socket read returned %d\n", n);
1118                         break;
1119                 }
1120                 if (!n) {
1121                         libwebsocket_close_and_free_session(this, wsi,
1122                                                      LWS_CLOSE_STATUS_NOSTATUS);
1123                         return 1;
1124                 }
1125
1126                 /* service incoming data */
1127
1128                 n = libwebsocket_read(this, wsi, buf, n);
1129                 if (n >= 0)
1130                         break;
1131
1132                 /* we closed wsi */
1133
1134                 return 1;
1135         }
1136
1137         return 0;
1138 }
1139
1140
1141 /**
1142  * libwebsocket_context_destroy() - Destroy the websocket context
1143  * @this:       Websocket context
1144  *
1145  *      This function closes any active connections and then frees the
1146  *      context.  After calling this, any further use of the context is
1147  *      undefined.
1148  */
1149 void
1150 libwebsocket_context_destroy(struct libwebsocket_context *this)
1151 {
1152         int n;
1153         int m;
1154         struct libwebsocket *wsi;
1155
1156         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1157                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1158                         wsi = this->fd_hashtable[n].wsi[m];
1159                         libwebsocket_close_and_free_session(this, wsi,
1160                                                     LWS_CLOSE_STATUS_GOINGAWAY);
1161                 }
1162
1163         close(this->fd_random);
1164
1165 #ifdef LWS_OPENSSL_SUPPORT
1166         if (this->ssl_ctx)
1167                 SSL_CTX_free(this->ssl_ctx);
1168         if (this->ssl_client_ctx)
1169                 SSL_CTX_free(this->ssl_client_ctx);
1170 #endif
1171
1172         free(this);
1173 }
1174
1175 /**
1176  * libwebsocket_service() - Service any pending websocket activity
1177  * @this:       Websocket context
1178  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
1179  *              service otherwise block and service immediately, returning
1180  *              after the timeout if nothing needed service.
1181  *
1182  *      This function deals with any pending websocket traffic, for three
1183  *      kinds of event.  It handles these events on both server and client
1184  *      types of connection the same.
1185  *
1186  *      1) Accept new connections to our context's server
1187  *
1188  *      2) Perform pending broadcast writes initiated from other forked
1189  *         processes (effectively serializing asynchronous broadcasts)
1190  *
1191  *      3) Call the receive callback for incoming frame data received by
1192  *          server or client connections.
1193  *
1194  *      You need to call this service function periodically to all the above
1195  *      functions to happen; if your application is single-threaded you can
1196  *      just call it in your main event loop.
1197  *
1198  *      Alternatively you can fork a new process that asynchronously handles
1199  *      calling this service in a loop.  In that case you are happy if this
1200  *      call blocks your thread until it needs to take care of something and
1201  *      would call it with a large nonzero timeout.  Your loop then takes no
1202  *      CPU while there is nothing happening.
1203  *
1204  *      If you are calling it in a single-threaded app, you don't want it to
1205  *      wait around blocking other things in your loop from happening, so you
1206  *      would call it with a timeout_ms of 0, so it returns immediately if
1207  *      nothing is pending, or as soon as it services whatever was pending.
1208  */
1209
1210
1211 int
1212 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
1213 {
1214         int n;
1215
1216         /* stay dead once we are dead */
1217
1218         if (this == NULL)
1219                 return 1;
1220
1221         /* wait for something to need service */
1222
1223         n = poll(this->fds, this->fds_count, timeout_ms);
1224         if (n == 0) /* poll timeout */
1225                 return 0;
1226
1227         if (n < 0) {
1228                 /*
1229                 fprintf(stderr, "Listen Socket dead\n");
1230                 */
1231                 return 1;
1232         }
1233
1234         /* handle accept on listening socket? */
1235
1236         for (n = 0; n < this->fds_count; n++)
1237                 if (this->fds[n].revents)
1238                         libwebsocket_service_fd(this, &this->fds[n]);
1239
1240         return 0;
1241 }
1242
1243 /**
1244  * libwebsocket_callback_on_writable() - Request a callback when this socket
1245  *                                       becomes able to be written to without
1246  *                                       blocking
1247  *
1248  * @this:       libwebsockets context
1249  * @wsi:        Websocket connection instance to get callback for
1250  */
1251
1252 int
1253 libwebsocket_callback_on_writable(struct libwebsocket_context *this,
1254                                                        struct libwebsocket *wsi)
1255 {
1256         int n;
1257
1258         for (n = 0; n < this->fds_count; n++)
1259                 if (this->fds[n].fd == wsi->sock) {
1260                         this->fds[n].events |= POLLOUT;
1261                         n = this->fds_count;
1262                 }
1263
1264         /* external POLL support via protocol 0 */
1265         this->protocols[0].callback(this, wsi,
1266                 LWS_CALLBACK_SET_MODE_POLL_FD,
1267                 (void *)(long)wsi->sock, NULL, POLLOUT);
1268
1269         return 1;
1270 }
1271
1272 /**
1273  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
1274  *                      all connections using the given protocol when it
1275  *                      becomes possible to write to each socket without
1276  *                      blocking in turn.
1277  *
1278  * @protocol:   Protocol whose connections will get callbacks
1279  */
1280
1281 int
1282 libwebsocket_callback_on_writable_all_protocol(
1283                                   const struct libwebsocket_protocols *protocol)
1284 {
1285         struct libwebsocket_context *this = protocol->owning_server;
1286         int n;
1287         int m;
1288         struct libwebsocket *wsi;
1289
1290         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1291
1292                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1293
1294                         wsi = this->fd_hashtable[n].wsi[m];
1295
1296                         if (wsi->protocol == protocol)
1297                                 libwebsocket_callback_on_writable(this, wsi);
1298                 }
1299         }
1300
1301         return 0;
1302 }
1303
1304 /**
1305  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
1306  *
1307  * You will not need this unless you are doing something special
1308  *
1309  * @wsi:        Websocket connection instance
1310  * @reason:     timeout reason
1311  * @secs:       how many seconds
1312  */
1313
1314 void
1315 libwebsocket_set_timeout(struct libwebsocket *wsi,
1316                                           enum pending_timeout reason, int secs)
1317 {
1318         struct timeval tv;
1319
1320         gettimeofday(&tv, NULL);
1321
1322         wsi->pending_timeout_limit = tv.tv_sec + secs;
1323         wsi->pending_timeout = reason;
1324 }
1325
1326
1327 /**
1328  * libwebsocket_get_socket_fd() - returns the socket file descriptor
1329  *
1330  * You will not need this unless you are doing something special
1331  *
1332  * @wsi:        Websocket connection instance
1333  */
1334
1335 int
1336 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
1337 {
1338         return wsi->sock;
1339 }
1340
1341 /**
1342  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
1343  *                              receieved packets.
1344  *
1345  * If the output side of a server process becomes choked, this allows flow
1346  * control for the input side.
1347  *
1348  * @wsi:        Websocket connection instance to get callback for
1349  * @enable:     0 = disable read servicing for this connection, 1 = enable
1350  */
1351
1352 int
1353 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
1354 {
1355         struct libwebsocket_context *this = wsi->protocol->owning_server;
1356         int n;
1357
1358         for (n = 0; n < this->fds_count; n++)
1359                 if (this->fds[n].fd == wsi->sock) {
1360                         if (enable)
1361                                 this->fds[n].events |= POLLIN;
1362                         else
1363                                 this->fds[n].events &= ~POLLIN;
1364
1365                         return 0;
1366                 }
1367
1368         if (enable)
1369                 /* external POLL support via protocol 0 */
1370                 this->protocols[0].callback(this, wsi,
1371                         LWS_CALLBACK_SET_MODE_POLL_FD,
1372                         (void *)(long)wsi->sock, NULL, POLLIN);
1373         else
1374                 /* external POLL support via protocol 0 */
1375                 this->protocols[0].callback(this, wsi,
1376                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1377                         (void *)(long)wsi->sock, NULL, POLLIN);
1378
1379
1380         fprintf(stderr, "libwebsocket_callback_on_writable "
1381                                                      "unable to find socket\n");
1382         return 1;
1383 }
1384
1385 /**
1386  * libwebsocket_canonical_hostname() - returns this host's hostname
1387  *
1388  * This is typically used by client code to fill in the host parameter
1389  * when making a client connection.  You can only call it after the context
1390  * has been created.
1391  *
1392  * @this:       Websocket context
1393  */
1394
1395
1396 extern const char *
1397 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
1398 {
1399         return (const char *)this->canonical_hostname;
1400 }
1401
1402
1403 static void sigpipe_handler(int x)
1404 {
1405 }
1406
1407 #ifdef LWS_OPENSSL_SUPPORT
1408 static int
1409 OpenSSL_verify_callback(int preverify_ok, X509_STORE_CTX *x509_ctx)
1410 {
1411
1412         SSL *ssl;
1413         int n;
1414 //      struct libwebsocket_context *this;
1415
1416         ssl = X509_STORE_CTX_get_ex_data(x509_ctx,
1417                 SSL_get_ex_data_X509_STORE_CTX_idx());
1418
1419         /*
1420          * !!! can't get this->openssl_websocket_private_data_index
1421          * can't store as a static either
1422          */
1423 //      this = SSL_get_ex_data(ssl, this->openssl_websocket_private_data_index);
1424
1425         n = this->protocols[0].callback(NULL, NULL,
1426                 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
1427                                                    x509_ctx, ssl, preverify_ok);
1428
1429         /* convert return code from 0 = OK to 1 = OK */
1430
1431         if (!n)
1432                 n = 1;
1433         else
1434                 n = 0;
1435
1436         return n;
1437 }
1438 #endif
1439
1440
1441 /**
1442  * libwebsocket_create_context() - Create the websocket handler
1443  * @port:       Port to listen on... you can use 0 to suppress listening on
1444  *              any port, that's what you want if you are not running a
1445  *              websocket server at all but just using it as a client
1446  * @interface:  NULL to bind the listen socket to all interfaces, or the
1447  *              interface name, eg, "eth2"
1448  * @protocols:  Array of structures listing supported protocols and a protocol-
1449  *              specific callback for each one.  The list is ended with an
1450  *              entry that has a NULL callback pointer.
1451  *              It's not const because we write the owning_server member
1452  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
1453  *                      to listen using SSL, set to the filepath to fetch the
1454  *                      server cert from, otherwise NULL for unencrypted
1455  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
1456  *                      else ignored
1457  * @gid:        group id to change to after setting listen socket, or -1.
1458  * @uid:        user id to change to after setting listen socket, or -1.
1459  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
1460  *
1461  *      This function creates the listening socket and takes care
1462  *      of all initialization in one step.
1463  *
1464  *      After initialization, it returns a struct libwebsocket_context * that
1465  *      represents this server.  After calling, user code needs to take care
1466  *      of calling libwebsocket_service() with the context pointer to get the
1467  *      server's sockets serviced.  This can be done in the same process context
1468  *      or a forked process, or another thread,
1469  *
1470  *      The protocol callback functions are called for a handful of events
1471  *      including http requests coming in, websocket connections becoming
1472  *      established, and data arriving; it's also called periodically to allow
1473  *      async transmission.
1474  *
1475  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
1476  *      at that time websocket protocol has not been negotiated.  Other
1477  *      protocols after the first one never see any HTTP callack activity.
1478  *
1479  *      The server created is a simple http server by default; part of the
1480  *      websocket standard is upgrading this http connection to a websocket one.
1481  *
1482  *      This allows the same server to provide files like scripts and favicon /
1483  *      images or whatever over http and dynamic data over websockets all in
1484  *      one place; they're all handled in the user callback.
1485  */
1486
1487 struct libwebsocket_context *
1488 libwebsocket_create_context(int port, const char *interface,
1489                                struct libwebsocket_protocols *protocols,
1490                                const char *ssl_cert_filepath,
1491                                const char *ssl_private_key_filepath,
1492                                int gid, int uid, unsigned int options)
1493 {
1494         int n;
1495         int sockfd = 0;
1496         int fd;
1497         struct sockaddr_in serv_addr, cli_addr;
1498         int opt = 1;
1499         struct libwebsocket_context *this = NULL;
1500         unsigned int slen;
1501         char *p;
1502         char hostname[1024];
1503         struct hostent *he;
1504         struct libwebsocket *wsi;
1505
1506 #ifdef LWS_OPENSSL_SUPPORT
1507         SSL_METHOD *method;
1508         char ssl_err_buf[512];
1509 #endif
1510
1511         this = malloc(sizeof(struct libwebsocket_context));
1512         if (!this) {
1513                 fprintf(stderr, "No memory for websocket context\n");
1514                 return NULL;
1515         }
1516         this->protocols = protocols;
1517         this->listen_port = port;
1518         this->http_proxy_port = 0;
1519         this->http_proxy_address[0] = '\0';
1520         this->options = options;
1521         this->fds_count = 0;
1522
1523         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
1524         if (this->fd_random < 0) {
1525                 fprintf(stderr, "Unable to open random device %s %d\n",
1526                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
1527                 return NULL;
1528         }
1529
1530         /* find canonical hostname */
1531
1532         hostname[(sizeof hostname) - 1] = '\0';
1533         gethostname(hostname, (sizeof hostname) - 1);
1534         he = gethostbyname(hostname);
1535         if (he) {
1536                 strncpy(this->canonical_hostname, he->h_name,
1537                                            sizeof this->canonical_hostname - 1);
1538                 this->canonical_hostname[sizeof this->canonical_hostname - 1] =
1539                                                                            '\0';
1540         } else
1541                 strncpy(this->canonical_hostname, hostname,
1542                                            sizeof this->canonical_hostname - 1);
1543
1544         /* split the proxy ads:port if given */
1545
1546         p = getenv("http_proxy");
1547         if (p) {
1548                 strncpy(this->http_proxy_address, p,
1549                                            sizeof this->http_proxy_address - 1);
1550                 this->http_proxy_address[
1551                                     sizeof this->http_proxy_address - 1] = '\0';
1552
1553                 p = strchr(this->http_proxy_address, ':');
1554                 if (p == NULL) {
1555                         fprintf(stderr, "http_proxy needs to be ads:port\n");
1556                         return NULL;
1557                 }
1558                 *p = '\0';
1559                 this->http_proxy_port = atoi(p + 1);
1560
1561                 fprintf(stderr, "Using proxy %s:%u\n",
1562                                 this->http_proxy_address,
1563                                                         this->http_proxy_port);
1564         }
1565
1566         if (port) {
1567
1568 #ifdef LWS_OPENSSL_SUPPORT
1569                 this->use_ssl = ssl_cert_filepath != NULL &&
1570                                                ssl_private_key_filepath != NULL;
1571                 if (this->use_ssl)
1572                         fprintf(stderr, " Compiled with SSL support, "
1573                                                                   "using it\n");
1574                 else
1575                         fprintf(stderr, " Compiled with SSL support, "
1576                                                               "not using it\n");
1577
1578 #else
1579                 if (ssl_cert_filepath != NULL &&
1580                                              ssl_private_key_filepath != NULL) {
1581                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
1582                         return NULL;
1583                 }
1584                 fprintf(stderr, " Compiled without SSL support, "
1585                                                        "serving unencrypted\n");
1586 #endif
1587         }
1588
1589         /* ignore SIGPIPE */
1590
1591         signal(SIGPIPE, sigpipe_handler);
1592
1593
1594 #ifdef LWS_OPENSSL_SUPPORT
1595
1596         /* basic openssl init */
1597
1598         SSL_library_init();
1599
1600         OpenSSL_add_all_algorithms();
1601         SSL_load_error_strings();
1602
1603         this->openssl_websocket_private_data_index =
1604                 SSL_get_ex_new_index(0, "libwebsockets", NULL, NULL, NULL);
1605
1606         /*
1607          * Firefox insists on SSLv23 not SSLv3
1608          * Konq disables SSLv2 by default now, SSLv23 works
1609          */
1610
1611         method = (SSL_METHOD *)SSLv23_server_method();
1612         if (!method) {
1613                 fprintf(stderr, "problem creating ssl method: %s\n",
1614                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1615                 return NULL;
1616         }
1617         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
1618         if (!this->ssl_ctx) {
1619                 fprintf(stderr, "problem creating ssl context: %s\n",
1620                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1621                 return NULL;
1622         }
1623
1624         /* client context */
1625
1626         method = (SSL_METHOD *)SSLv23_client_method();
1627         if (!method) {
1628                 fprintf(stderr, "problem creating ssl method: %s\n",
1629                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1630                 return NULL;
1631         }
1632         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
1633         if (!this->ssl_client_ctx) {
1634                 fprintf(stderr, "problem creating ssl context: %s\n",
1635                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1636                 return NULL;
1637         }
1638
1639
1640         /* openssl init for cert verification (used with client sockets) */
1641
1642         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
1643                                                     LWS_OPENSSL_CLIENT_CERTS)) {
1644                 fprintf(stderr, "Unable to load SSL Client certs from %s "
1645                         "(set by --with-client-cert-dir= in configure) -- "
1646                         " client ssl isn't going to work",
1647                                                       LWS_OPENSSL_CLIENT_CERTS);
1648         }
1649
1650         /*
1651          * callback allowing user code to load extra verification certs
1652          * helping the client to verify server identity
1653          */
1654
1655         this->protocols[0].callback(this, NULL,
1656                 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
1657                 this->ssl_client_ctx, NULL, 0);
1658
1659         /* as a server, are we requiring clients to identify themselves? */
1660
1661         if (options & LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT) {
1662
1663                 /* absolutely require the client cert */
1664
1665                 SSL_CTX_set_verify(this->ssl_ctx,
1666                        SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
1667                                                        OpenSSL_verify_callback);
1668
1669                 /*
1670                  * give user code a chance to load certs into the server
1671                  * allowing it to verify incoming client certs
1672                  */
1673
1674                 this->protocols[0].callback(this, NULL,
1675                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
1676                                                         this->ssl_ctx, NULL, 0);
1677         }
1678
1679         if (this->use_ssl) {
1680
1681                 /* openssl init for server sockets */
1682
1683                 /* set the local certificate from CertFile */
1684                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
1685                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
1686                 if (n != 1) {
1687                         fprintf(stderr, "problem getting cert '%s': %s\n",
1688                                 ssl_cert_filepath,
1689                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1690                         return NULL;
1691                 }
1692                 /* set the private key from KeyFile */
1693                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
1694                                                 ssl_private_key_filepath,
1695                                                        SSL_FILETYPE_PEM) != 1) {
1696                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
1697                                                 ssl_private_key_filepath,
1698                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1699                         return NULL;
1700                 }
1701                 /* verify private key */
1702                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
1703                         fprintf(stderr, "Private SSL key doesn't match cert\n");
1704                         return NULL;
1705                 }
1706
1707                 /* SSL is happy and has a cert it's content with */
1708         }
1709 #endif
1710
1711         /* selftest */
1712
1713         if (lws_b64_selftest())
1714                 return NULL;
1715
1716         /* fd hashtable init */
1717
1718         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1719                 this->fd_hashtable[n].length = 0;
1720
1721         /* set up our external listening socket we serve on */
1722
1723         if (port) {
1724
1725                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1726                 if (sockfd < 0) {
1727                         fprintf(stderr, "ERROR opening socket");
1728                         return NULL;
1729                 }
1730
1731                 /* allow us to restart even if old sockets in TIME_WAIT */
1732                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1733
1734                 bzero((char *) &serv_addr, sizeof(serv_addr));
1735                 serv_addr.sin_family = AF_INET;
1736                 if (interface == NULL)
1737                         serv_addr.sin_addr.s_addr = INADDR_ANY;
1738                 else
1739                         interface_to_sa(interface, &serv_addr,
1740                                                 sizeof(serv_addr));
1741                 serv_addr.sin_port = htons(port);
1742
1743                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
1744                                                              sizeof(serv_addr));
1745                 if (n < 0) {
1746                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1747                                                                 port, n, errno);
1748                         return NULL;
1749                 }
1750
1751                 wsi = malloc(sizeof(struct libwebsocket));
1752                 memset(wsi, 0, sizeof (struct libwebsocket));
1753                 wsi->sock = sockfd;
1754                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
1755                 insert_wsi(this, wsi);
1756
1757                 listen(sockfd, 5);
1758                 fprintf(stderr, " Listening on port %d\n", port);
1759
1760                 /* list in the internal poll array */
1761
1762                 this->fds[this->fds_count].fd = sockfd;
1763                 this->fds[this->fds_count++].events = POLLIN;
1764
1765                 /* external POLL support via protocol 0 */
1766                 this->protocols[0].callback(this, wsi,
1767                         LWS_CALLBACK_ADD_POLL_FD,
1768                         (void *)(long)sockfd, NULL, POLLIN);
1769
1770         }
1771
1772         /* drop any root privs for this process */
1773
1774         if (gid != -1)
1775                 if (setgid(gid))
1776                         fprintf(stderr, "setgid: %s\n", strerror(errno));
1777         if (uid != -1)
1778                 if (setuid(uid))
1779                         fprintf(stderr, "setuid: %s\n", strerror(errno));
1780
1781
1782         /* set up our internal broadcast trigger sockets per-protocol */
1783
1784         for (this->count_protocols = 0;
1785                         protocols[this->count_protocols].callback;
1786                                                       this->count_protocols++) {
1787                 protocols[this->count_protocols].owning_server = this;
1788                 protocols[this->count_protocols].protocol_index =
1789                                                           this->count_protocols;
1790
1791                 fd = socket(AF_INET, SOCK_STREAM, 0);
1792                 if (fd < 0) {
1793                         fprintf(stderr, "ERROR opening socket");
1794                         return NULL;
1795                 }
1796
1797                 /* allow us to restart even if old sockets in TIME_WAIT */
1798                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1799
1800                 bzero((char *) &serv_addr, sizeof(serv_addr));
1801                 serv_addr.sin_family = AF_INET;
1802                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1803                 serv_addr.sin_port = 0; /* pick the port for us */
1804
1805                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
1806                 if (n < 0) {
1807                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1808                                                                 port, n, errno);
1809                         return NULL;
1810                 }
1811
1812                 slen = sizeof cli_addr;
1813                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
1814                 if (n < 0) {
1815                         fprintf(stderr, "getsockname failed\n");
1816                         return NULL;
1817                 }
1818                 protocols[this->count_protocols].broadcast_socket_port =
1819                                                        ntohs(cli_addr.sin_port);
1820                 listen(fd, 5);
1821
1822                 debug("  Protocol %s broadcast socket %d\n",
1823                                 protocols[this->count_protocols].name,
1824                                                       ntohs(cli_addr.sin_port));
1825
1826                 /* dummy wsi per broadcast proxy socket */
1827
1828                 wsi = malloc(sizeof(struct libwebsocket));
1829                 memset(wsi, 0, sizeof (struct libwebsocket));
1830                 wsi->sock = fd;
1831                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
1832                 /* note which protocol we are proxying */
1833                 wsi->protocol_index_for_broadcast_proxy = this->count_protocols;
1834                 insert_wsi(this, wsi);
1835
1836                 /* list in internal poll array */
1837
1838                 this->fds[this->fds_count].fd = fd;
1839                 this->fds[this->fds_count].events = POLLIN;
1840                 this->fds[this->fds_count].revents = 0;
1841                 this->fds_count++;
1842
1843                 /* external POLL support via protocol 0 */
1844                 this->protocols[0].callback(this, wsi,
1845                         LWS_CALLBACK_ADD_POLL_FD,
1846                         (void *)(long)fd, NULL, POLLIN);
1847         }
1848
1849         return this;
1850 }
1851
1852
1853 #ifndef LWS_NO_FORK
1854
1855 /**
1856  * libwebsockets_fork_service_loop() - Optional helper function forks off
1857  *                                a process for the websocket server loop.
1858  *                              You don't have to use this but if not, you
1859  *                              have to make sure you are calling
1860  *                              libwebsocket_service periodically to service
1861  *                              the websocket traffic
1862  * @this:       server context returned by creation function
1863  */
1864
1865 int
1866 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
1867 {
1868         int fd;
1869         struct sockaddr_in cli_addr;
1870         int n;
1871         int p;
1872
1873         n = fork();
1874         if (n < 0)
1875                 return n;
1876
1877         if (!n) {
1878
1879                 /* main process context */
1880
1881                 /*
1882                  * set up the proxy sockets to allow broadcast from
1883                  * service process context
1884                  */
1885
1886                 for (p = 0; p < this->count_protocols; p++) {
1887                         fd = socket(AF_INET, SOCK_STREAM, 0);
1888                         if (fd < 0) {
1889                                 fprintf(stderr, "Unable to create socket\n");
1890                                 return -1;
1891                         }
1892                         cli_addr.sin_family = AF_INET;
1893                         cli_addr.sin_port = htons(
1894                              this->protocols[p].broadcast_socket_port);
1895                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1896                         n = connect(fd, (struct sockaddr *)&cli_addr,
1897                                                                sizeof cli_addr);
1898                         if (n < 0) {
1899                                 fprintf(stderr, "Unable to connect to "
1900                                                 "broadcast socket %d, %s\n",
1901                                                 n, strerror(errno));
1902                                 return -1;
1903                         }
1904
1905                         this->protocols[p].broadcast_socket_user_fd = fd;
1906                 }
1907
1908                 return 0;
1909         }
1910
1911         /* we want a SIGHUP when our parent goes down */
1912         prctl(PR_SET_PDEATHSIG, SIGHUP);
1913
1914         /* in this forked process, sit and service websocket connections */
1915
1916         while (1)
1917                 if (libwebsocket_service(this, 1000))
1918                         return -1;
1919
1920         return 0;
1921 }
1922
1923 #endif
1924
1925 /**
1926  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1927  *                                connection.
1928  * @wsi:        pointer to struct websocket you want to know the protocol of
1929  *
1930  *
1931  *      This is useful to get the protocol to broadcast back to from inside
1932  * the callback.
1933  */
1934
1935 const struct libwebsocket_protocols *
1936 libwebsockets_get_protocol(struct libwebsocket *wsi)
1937 {
1938         return wsi->protocol;
1939 }
1940
1941 /**
1942  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1943  *                                connections of the given protocol.
1944  * @protocol:   pointer to the protocol you will broadcast to all members of
1945  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1946  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1947  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1948  *              case you are calling this function from callback context.
1949  * @len:        length of payload data in buf, starting from buf.
1950  *
1951  *      This function allows bulk sending of a packet to every connection using
1952  * the given protocol.  It does not send the data directly; instead it calls
1953  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1954  * wants to actually send the data for that connection, the callback itself
1955  * should call libwebsocket_write().
1956  *
1957  * libwebsockets_broadcast() can be called from another fork context without
1958  * having to take any care about data visibility between the processes, it'll
1959  * "just work".
1960  */
1961
1962
1963 int
1964 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1965                                                  unsigned char *buf, size_t len)
1966 {
1967         struct libwebsocket_context *this = protocol->owning_server;
1968         int n;
1969         int m;
1970         struct libwebsocket * wsi;
1971
1972         if (!protocol->broadcast_socket_user_fd) {
1973                 /*
1974                  * We are either running unforked / flat, or we are being
1975                  * called from poll thread context
1976                  * eg, from a callback.  In that case don't use sockets for
1977                  * broadcast IPC (since we can't open a socket connection to
1978                  * a socket listening on our own thread) but directly do the
1979                  * send action.
1980                  *
1981                  * Locking is not needed because we are by definition being
1982                  * called in the poll thread context and are serialized.
1983                  */
1984
1985                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1986
1987                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
1988
1989                                 wsi = this->fd_hashtable[n].wsi[m];
1990
1991                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
1992                                         continue;
1993
1994                                 /*
1995                                  * never broadcast to
1996                                  * non-established connections
1997                                  */
1998                                 if (wsi->state != WSI_STATE_ESTABLISHED)
1999                                         continue;
2000
2001                                 /* only broadcast to guys using
2002                                  * requested protocol
2003                                  */
2004                                 if (wsi->protocol != protocol)
2005                                         continue;
2006
2007                                 wsi->protocol->callback(this, wsi,
2008                                          LWS_CALLBACK_BROADCAST,
2009                                          wsi->user_space,
2010                                          buf, len);
2011                         }
2012                 }
2013
2014                 return 0;
2015         }
2016
2017         /*
2018          * We're being called from a different process context than the server
2019          * loop.  Instead of broadcasting directly, we send our
2020          * payload on a socket to do the IPC; the server process will serialize
2021          * the broadcast action in its main poll() loop.
2022          *
2023          * There's one broadcast socket listening for each protocol supported
2024          * set up when the websocket server initializes
2025          */
2026
2027         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
2028
2029         return n;
2030 }