lib/libwebsockets.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23 #include <ifaddrs.h>
  24
  25 /*
  26  * In-place str to lower case
  27  */
  28
  29 static void
  30 strtolower(char *s)
  31 {
  32         while (*s) {
  33                 *s = tolower(*s);
  34                 s++;
  35         }
  36 }
  37
  38 /* file descriptor hash management */
  39
  40 struct libwebsocket *
  41 wsi_from_fd(struct libwebsocket_context *this, int fd)
  42 {
  43         int h = LWS_FD_HASH(fd);
  44         int n = 0;
  45
  46         for (n = 0; n < this->fd_hashtable[h].length; n++)
  47                 if (this->fd_hashtable[h].wsi[n]->sock == fd)
  48                         return this->fd_hashtable[h].wsi[n];
  49
  50         return NULL;
  51 }
  52
  53 int
  54 insert_wsi(struct libwebsocket_context *this, struct libwebsocket *wsi)
  55 {
  56         int h = LWS_FD_HASH(wsi->sock);
  57
  58         if (this->fd_hashtable[h].length == MAX_CLIENTS - 1) {
  59                 fprintf(stderr, "hash table overflow\n");
  60                 return 1;
  61         }
  62
  63         this->fd_hashtable[h].wsi[this->fd_hashtable[h].length++] = wsi;
  64
  65         return 0;
  66 }
  67
  68 int
  69 delete_from_fd(struct libwebsocket_context *this, int fd)
  70 {
  71         int h = LWS_FD_HASH(fd);
  72         int n = 0;
  73
  74         for (n = 0; n < this->fd_hashtable[h].length; n++)
  75                 if (this->fd_hashtable[h].wsi[n]->sock == fd) {
  76                         while (n < this->fd_hashtable[h].length) {
  77                                 this->fd_hashtable[h].wsi[n] =
  78                                                this->fd_hashtable[h].wsi[n + 1];
  79                                 n++;
  80                         }
  81                         this->fd_hashtable[h].length--;
  82
  83                         return 0;
  84                 }
  85
  86         fprintf(stderr, "Failed to find fd %d requested for "
  87                                                    "delete in hashtable\n", fd);
  88         return 1;
  89 }
  90
  91 #ifdef LWS_OPENSSL_SUPPORT
  92 static void
  93 libwebsockets_decode_ssl_error(void)
  94 {
  95         char buf[256];
  96         u_long err;
  97
  98         while ((err = ERR_get_error()) != 0) {
  99                 ERR_error_string_n(err, buf, sizeof(buf));
 100                 fprintf(stderr, "*** %s\n", buf);
 101         }
 102 }
 103 #endif
 104
 105
 106 static int
 107 interface_to_sa(const char* ifname, struct sockaddr_in *addr, size_t addrlen)
 108 {
 109         int rc = -1;
 110         struct ifaddrs *ifr;
 111         struct ifaddrs *ifc;
 112         struct sockaddr_in *sin;
 113
 114         getifaddrs(&ifr);
 115         for (ifc = ifr; ifc != NULL; ifc = ifc->ifa_next) {
 116                 if (strcmp(ifc->ifa_name, ifname))
 117                         continue;
 118                 if (ifc->ifa_addr == NULL)
 119                         continue;
 120                 sin = (struct sockaddr_in *)ifc->ifa_addr;
 121                 if (sin->sin_family != AF_INET)
 122                         continue;
 123                 memcpy(addr, sin, addrlen);
 124                 rc = 0;
 125         }
 126
 127         freeifaddrs(ifr);
 128
 129         return rc;
 130 }
 131
 132 void
 133 libwebsocket_close_and_free_session(struct libwebsocket_context *this,
 134                                                        struct libwebsocket *wsi)
 135 {
 136         int n;
 137         int old_state;
 138         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
 139                                                   LWS_SEND_BUFFER_POST_PADDING];
 140
 141         if (!wsi)
 142                 return;
 143
 144         old_state = wsi->state;
 145
 146         if (old_state == WSI_STATE_DEAD_SOCKET)
 147                 return;
 148
 149         /* remove this fd from wsi mapping hashtable */
 150
 151         delete_from_fd(this, wsi->sock);
 152
 153         /* delete it from the internal poll list if still present */
 154
 155         for (n = 0; n < this->fds_count; n++) {
 156                 if (this->fds[n].fd != wsi->sock)
 157                         continue;
 158                 while (n < this->fds_count - 1) {
 159                         this->fds[n] = this->fds[n + 1];
 160                         n++;
 161                 }
 162                 this->fds_count--;
 163                 /* we only have to deal with one */
 164                 n = this->fds_count;
 165         }
 166
 167         /* remove also from external POLL support via protocol 0 */
 168
 169         this->protocols[0].callback(this, wsi,
 170                     LWS_CALLBACK_DEL_POLL_FD, (void *)(long)wsi->sock, NULL, 0);
 171
 172         /*
 173          * signal we are closing, libsocket_write will
 174          * add any necessary version-specific stuff.  If the write fails,
 175          * no worries we are closing anyway.  If we didn't initiate this
 176          * close, then our state has been changed to
 177          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this
 178          */
 179
 180         if (old_state == WSI_STATE_ESTABLISHED)
 181                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
 182                                                                LWS_WRITE_CLOSE);
 183
 184         wsi->state = WSI_STATE_DEAD_SOCKET;
 185
 186         /* tell the user it's all over for this guy */
 187
 188         if (wsi->protocol->callback && old_state == WSI_STATE_ESTABLISHED)
 189                 wsi->protocol->callback(this, wsi, LWS_CALLBACK_CLOSED,
 190                                                       wsi->user_space, NULL, 0);
 191
 192         /* free up his allocations */
 193
 194         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 195                 if (wsi->utf8_token[n].token)
 196                         free(wsi->utf8_token[n].token);
 197
 198 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 199
 200 #ifdef LWS_OPENSSL_SUPPORT
 201         if (wsi->ssl) {
 202                 n = SSL_get_fd(wsi->ssl);
 203                 SSL_shutdown(wsi->ssl);
 204                 close(n);
 205                 SSL_free(wsi->ssl);
 206         } else {
 207 #endif
 208                 shutdown(wsi->sock, SHUT_RDWR);
 209                 close(wsi->sock);
 210 #ifdef LWS_OPENSSL_SUPPORT
 211         }
 212 #endif
 213         if (wsi->user_space)
 214                 free(wsi->user_space);
 215
 216         free(wsi);
 217 }
 218
 219 /**
 220  * libwebsockets_hangup_on_client() - Server calls to terminate client
 221  *                                      connection
 222  * @this:       libwebsockets context
 223  * @fd:         Connection socket descriptor
 224  */
 225
 226 void
 227 libwebsockets_hangup_on_client(struct libwebsocket_context *this, int fd)
 228 {
 229         struct libwebsocket *wsi = wsi_from_fd(this, fd);
 230         int n;
 231
 232         if (wsi == NULL)
 233                 return;
 234
 235         delete_from_fd(this, fd);
 236
 237         for (n = 0; n < this->fds_count - 1; n++)
 238                 if (this->fds[n].fd == fd) {
 239                         while (n < this->fds_count - 1) {
 240                                 this->fds[n] = this->fds[n + 1];
 241                                 n++;
 242                         }
 243                         n = this->fds_count;
 244                         this->fds_count--;
 245                 }
 246
 247         libwebsocket_close_and_free_session(this, wsi);
 248 }
 249
 250
 251 /**
 252  * libwebsockets_get_peer_addresses() - Get client address information
 253  * @fd:         Connection socket descriptor
 254  * @name:       Buffer to take client address name
 255  * @name_len:   Length of client address name buffer
 256  * @rip:        Buffer to take client address IP qotted quad
 257  * @rip_len:    Length of client address IP buffer
 258  *
 259  *      This function fills in @name and @rip with the name and IP of
 260  *      the client connected with socket descriptor @fd.  Names may be
 261  *      truncated if there is not enough room.  If either cannot be
 262  *      determined, they will be returned as valid zero-length strings.
 263  */
 264
 265 void
 266 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 267                                         char *rip, int rip_len)
 268 {
 269         unsigned int len;
 270         struct sockaddr_in sin;
 271         struct hostent *host;
 272         struct hostent *host1;
 273         char ip[128];
 274         char *p;
 275         int n;
 276
 277         rip[0] = '\0';
 278         name[0] = '\0';
 279
 280         len = sizeof sin;
 281         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 282                 perror("getpeername");
 283                 return;
 284         }
 285
 286         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 287                                                                        AF_INET);
 288         if (host == NULL) {
 289                 perror("gethostbyaddr");
 290                 return;
 291         }
 292
 293         strncpy(name, host->h_name, name_len);
 294         name[name_len - 1] = '\0';
 295
 296         host1 = gethostbyname(host->h_name);
 297         if (host1 == NULL)
 298                 return;
 299         p = (char *)host1;
 300         n = 0;
 301         while (p != NULL) {
 302                 p = host1->h_addr_list[n++];
 303                 if (p == NULL)
 304                         continue;
 305                 if (host1->h_addrtype != AF_INET)
 306                         continue;
 307
 308                 sprintf(ip, "%d.%d.%d.%d",
 309                                 p[0], p[1], p[2], p[3]);
 310                 p = NULL;
 311                 strncpy(rip, ip, rip_len);
 312                 rip[rip_len - 1] = '\0';
 313         }
 314 }
 315
 316 /**
 317  * libwebsocket_service_fd() - Service polled socket with something waiting
 318  * @this:       Websocket context
 319  * @pollfd:     The pollfd entry describing the socket fd and which events
 320  *              happened.
 321  *
 322  *      This function closes any active connections and then frees the
 323  *      context.  After calling this, any further use of the context is
 324  *      undefined.
 325  */
 326
 327 int
 328 libwebsocket_service_fd(struct libwebsocket_context *this,
 329                                                           struct pollfd *pollfd)
 330 {
 331         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
 332                                                   LWS_SEND_BUFFER_POST_PADDING];
 333         struct libwebsocket *wsi;
 334         struct libwebsocket *new_wsi;
 335         int n;
 336         int m;
 337         size_t len;
 338         int accept_fd;
 339         unsigned int clilen;
 340         struct sockaddr_in cli_addr;
 341         struct timeval tv;
 342         static const char magic_websocket_guid[] =
 343                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 344         static const char magic_websocket_04_masking_guid[] =
 345                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 346         char hash[20];
 347         char pkt[1024];
 348         char *p = &pkt[0];
 349         const char *pc;
 350         int okay = 0;
 351 #ifdef LWS_OPENSSL_SUPPORT
 352         char ssl_err_buf[512];
 353 #endif
 354         /*
 355          * you can call us with pollfd = NULL to just allow the once-per-second
 356          * global timeout checks; if less than a second since the last check
 357          * it returns immediately then.
 358          */
 359
 360         gettimeofday(&tv, NULL);
 361
 362         if (this->last_timeout_check_s != tv.tv_sec) {
 363                 this->last_timeout_check_s = tv.tv_sec;
 364
 365                 /* global timeout check once per second */
 366
 367                 for (n = 0; n < this->fds_count; n++) {
 368                         wsi = wsi_from_fd(this, this->fds[n].fd);
 369                         if (!wsi->pending_timeout)
 370                                 continue;
 371
 372                         /*
 373                          * if we went beyond the allowed time, kill the
 374                          * connection
 375                          */
 376
 377                         if (tv.tv_sec > wsi->pending_timeout_limit)
 378                                 libwebsocket_close_and_free_session(this, wsi);
 379                 }
 380         }
 381
 382         /* just here for timeout management? */
 383
 384         if (pollfd == NULL)
 385                 return 0;
 386
 387         /* no, here to service a socket descriptor */
 388
 389         wsi = wsi_from_fd(this, pollfd->fd);
 390
 391         if (wsi == NULL)
 392                 return 1;
 393
 394         switch (wsi->mode) {
 395         case LWS_CONNMODE_SERVER_LISTENER:
 396
 397                 /* pollin means a client has connected to us then */
 398
 399                 if (!pollfd->revents & POLLIN)
 400                         break;
 401
 402                 /* listen socket got an unencrypted connection... */
 403
 404                 clilen = sizeof(cli_addr);
 405                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 406                                                                        &clilen);
 407                 if (accept_fd < 0) {
 408                         fprintf(stderr, "ERROR on accept");
 409                         break;
 410                 }
 411
 412                 if (this->fds_count >= MAX_CLIENTS) {
 413                         fprintf(stderr, "too busy to accept new client\n");
 414                         close(accept_fd);
 415                         break;
 416                 }
 417
 418                 /*
 419                  * look at who we connected to and give user code a chance
 420                  * to reject based on client IP.  There's no protocol selected
 421                  * yet so we issue this to protocols[0]
 422                  */
 423
 424                 if ((this->protocols[0].callback)(this, wsi,
 425                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 426                                              (void*)(long)accept_fd, NULL, 0)) {
 427                         fprintf(stderr, "Callback denied network connection\n");
 428                         close(accept_fd);
 429                         break;
 430                 }
 431
 432                 /* accepting connection to main listener */
 433
 434                 new_wsi = malloc(sizeof(struct libwebsocket));
 435                 if (new_wsi == NULL) {
 436                         fprintf(stderr, "Out of memory for new connection\n");
 437                         break;
 438                 }
 439
 440                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 441                 new_wsi->sock = accept_fd;
 442                 new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
 443
 444 #ifdef LWS_OPENSSL_SUPPORT
 445                 new_wsi->ssl = NULL;
 446
 447                 if (this->use_ssl) {
 448
 449                         new_wsi->ssl = SSL_new(this->ssl_ctx);
 450                         if (new_wsi->ssl == NULL) {
 451                                 fprintf(stderr, "SSL_new failed: %s\n",
 452                                     ERR_error_string(SSL_get_error(
 453                                     new_wsi->ssl, 0), NULL));
 454                                     libwebsockets_decode_ssl_error();
 455                                 free(new_wsi);
 456                                 break;
 457                         }
 458
 459                         SSL_set_fd(new_wsi->ssl, accept_fd);
 460
 461                         n = SSL_accept(new_wsi->ssl);
 462                         if (n != 1) {
 463                                 /*
 464                                  * browsers seem to probe with various
 465                                  * ssl params which fail then retry
 466                                  * and succeed
 467                                  */
 468                                 debug("SSL_accept failed skt %u: %s\n",
 469                                       pollfd->fd,
 470                                       ERR_error_string(SSL_get_error(
 471                                       new_wsi->ssl, n), NULL));
 472                                 SSL_free(
 473                                        new_wsi->ssl);
 474                                 free(new_wsi);
 475                                 break;
 476                         }
 477                         debug("accepted new SSL conn  "
 478                               "port %u on fd=%d SSL ver %s\n",
 479                                 ntohs(cli_addr.sin_port), accept_fd,
 480                                   SSL_get_version(new_wsi->ssl));
 481
 482                 } else
 483 #endif
 484                         debug("accepted new conn  port %u on fd=%d\n",
 485                                           ntohs(cli_addr.sin_port), accept_fd);
 486
 487                 /* intialize the instance struct */
 488
 489                 new_wsi->state = WSI_STATE_HTTP;
 490                 new_wsi->name_buffer_pos = 0;
 491                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 492
 493                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 494                         new_wsi->utf8_token[n].token = NULL;
 495                         new_wsi->utf8_token[n].token_len = 0;
 496                 }
 497
 498                 /*
 499                  * these can only be set once the protocol is known
 500                  * we set an unestablished connection's protocol pointer
 501                  * to the start of the supported list, so it can look
 502                  * for matching ones during the handshake
 503                  */
 504                 new_wsi->protocol = this->protocols;
 505                 new_wsi->user_space = NULL;
 506
 507                 /*
 508                  * Default protocol is 76 / 00
 509                  * After 76, there's a header specified to inform which
 510                  * draft the client wants, when that's seen we modify
 511                  * the individual connection's spec revision accordingly
 512                  */
 513                 new_wsi->ietf_spec_revision = 0;
 514
 515                 insert_wsi(this, new_wsi);
 516
 517                 /*
 518                  * make sure NO events are seen yet on this new socket
 519                  * (otherwise we inherit old fds[client].revents from
 520                  * previous socket there and die mysteriously! )
 521                  */
 522                 this->fds[this->fds_count].revents = 0;
 523
 524                 this->fds[this->fds_count].events = POLLIN;
 525                 this->fds[this->fds_count++].fd = accept_fd;
 526
 527                 /* external POLL support via protocol 0 */
 528                 this->protocols[0].callback(this, new_wsi,
 529                         LWS_CALLBACK_ADD_POLL_FD,
 530                         (void *)(long)accept_fd, NULL, POLLIN);
 531
 532                 break;
 533
 534         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 535
 536                 /* as we are listening, POLLIN means accept() is needed */
 537
 538                 if (!pollfd->revents & POLLIN)
 539                         break;
 540
 541                 /* listen socket got an unencrypted connection... */
 542
 543                 clilen = sizeof(cli_addr);
 544                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 545                                                                        &clilen);
 546                 if (accept_fd < 0) {
 547                         fprintf(stderr, "ERROR on accept");
 548                         break;
 549                 }
 550
 551                 if (this->fds_count >= MAX_CLIENTS) {
 552                         fprintf(stderr, "too busy to accept new broadcast "
 553                                                               "proxy client\n");
 554                         close(accept_fd);
 555                         break;
 556                 }
 557
 558                 /* create a dummy wsi for the connection and add it */
 559
 560                 new_wsi = malloc(sizeof(struct libwebsocket));
 561                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 562                 new_wsi->sock = accept_fd;
 563                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 564                 new_wsi->state = WSI_STATE_ESTABLISHED;
 565                 /* note which protocol we are proxying */
 566                 new_wsi->protocol_index_for_broadcast_proxy =
 567                                         wsi->protocol_index_for_broadcast_proxy;
 568                 insert_wsi(this, new_wsi);
 569
 570                 /* add connected socket to internal poll array */
 571
 572                 this->fds[this->fds_count].revents = 0;
 573                 this->fds[this->fds_count].events = POLLIN;
 574                 this->fds[this->fds_count++].fd = accept_fd;
 575
 576                 /* external POLL support via protocol 0 */
 577                 this->protocols[0].callback(this, new_wsi,
 578                         LWS_CALLBACK_ADD_POLL_FD,
 579                         (void *)(long)accept_fd, NULL, POLLIN);
 580
 581                 break;
 582
 583         case LWS_CONNMODE_BROADCAST_PROXY:
 584
 585                 /* handle session socket closed */
 586
 587                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 588
 589                         debug("Session Socket %p (fd=%d) dead\n",
 590                                 (void *)wsi, pollfd->fd);
 591
 592                         libwebsocket_close_and_free_session(this, wsi);
 593                         return 1;
 594                 }
 595
 596                 /* the guy requested a callback when it was OK to write */
 597
 598                 if (pollfd->revents & POLLOUT) {
 599
 600                         /* one shot */
 601
 602                         pollfd->events &= ~POLLOUT;
 603
 604                         /* external POLL support via protocol 0 */
 605                         this->protocols[0].callback(this, wsi,
 606                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 607                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 608
 609                         wsi->protocol->callback(this, wsi,
 610                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 611                                 wsi->user_space,
 612                                 NULL, 0);
 613                 }
 614
 615                 /* any incoming data ready? */
 616
 617                 if (!(pollfd->revents & POLLIN))
 618                         break;
 619
 620                 /* get the issued broadcast payload from the socket */
 621
 622                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 623                                                          MAX_BROADCAST_PAYLOAD);
 624                 if (len < 0) {
 625                         fprintf(stderr, "Error reading broadcast payload\n");
 626                         break;
 627                 }
 628
 629                 /* broadcast it to all guys with this protocol index */
 630
 631                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 632
 633                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
 634
 635                                 new_wsi = this->fd_hashtable[n].wsi[m];
 636
 637                                 /* only to clients we are serving to */
 638
 639                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 640                                         continue;
 641
 642                                 /*
 643                                  * never broadcast to non-established
 644                                  * connection
 645                                  */
 646
 647                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 648                                         continue;
 649
 650                                 /*
 651                                  * only broadcast to connections using
 652                                  * the requested protocol
 653                                  */
 654
 655                                 if (new_wsi->protocol->protocol_index !=
 656                                         wsi->protocol_index_for_broadcast_proxy)
 657                                         continue;
 658
 659                                 /* broadcast it to this connection */
 660
 661                                 new_wsi->protocol->callback(this, new_wsi,
 662                                         LWS_CALLBACK_BROADCAST,
 663                                         new_wsi->user_space,
 664                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 665                         }
 666                 }
 667                 break;
 668
 669         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
 670
 671                 /* handle proxy hung up on us */
 672
 673                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 674
 675                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
 676                                 (void *)wsi, pollfd->fd);
 677
 678                         libwebsocket_close_and_free_session(this, wsi);
 679                         return 1;
 680                 }
 681
 682                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
 683                 if (n < 0) {
 684                         libwebsocket_close_and_free_session(this, wsi);
 685                         fprintf(stderr, "ERROR reading from proxy socket\n");
 686                         return 1;
 687                 }
 688
 689                 pkt[13] = '\0';
 690                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
 691                         libwebsocket_close_and_free_session(this, wsi);
 692                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
 693                         return 1;
 694                 }
 695
 696                 /* clear his proxy connection timeout */
 697
 698                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 699
 700                 /* fallthru */
 701
 702         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
 703
 704         #ifdef LWS_OPENSSL_SUPPORT
 705                 if (wsi->use_ssl) {
 706
 707                         wsi->ssl = SSL_new(this->ssl_client_ctx);
 708                         wsi->client_bio = BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 709                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 710
 711                         if (SSL_connect(wsi->ssl) <= 0) {
 712                                 fprintf(stderr, "SSL connect error %s\n",
 713                                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 714                                 libwebsocket_close_and_free_session(this, wsi);
 715                                 return 1;
 716                         }
 717
 718                         n = SSL_get_verify_result(wsi->ssl);
 719                         if (n != X509_V_OK) {
 720                                 if (n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 721                                                             wsi->use_ssl != 2) {
 722
 723                                         fprintf(stderr, "server's cert didn't "
 724                                                                    "look good %d\n", n);
 725                                         libwebsocket_close_and_free_session(this, wsi);
 726                                         return 1;
 727                                 }
 728                         }
 729                 } else {
 730                         wsi->ssl = NULL;
 731         #endif
 732
 733
 734         #ifdef LWS_OPENSSL_SUPPORT
 735                 }
 736         #endif
 737
 738                 /*
 739                  * create the random key
 740                  */
 741
 742                 n = read(this->fd_random, hash, 16);
 743                 if (n != 16) {
 744                         fprintf(stderr, "Unable to read from random dev %s\n",
 745                                                         SYSTEM_RANDOM_FILEPATH);
 746                         free(wsi->c_path);
 747                         free(wsi->c_host);
 748                         free(wsi->c_origin);
 749                         if (wsi->c_protocol)
 750                                 free(wsi->c_protocol);
 751                         libwebsocket_close_and_free_session(this, wsi);
 752                         return 1;
 753                 }
 754
 755                 lws_b64_encode_string(hash, 16, wsi->key_b64,
 756                                                            sizeof wsi->key_b64);
 757
 758                 /*
 759                  * 04 example client handshake
 760                  *
 761                  * GET /chat HTTP/1.1
 762                  * Host: server.example.com
 763                  * Upgrade: websocket
 764                  * Connection: Upgrade
 765                  * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 766                  * Sec-WebSocket-Origin: http://example.com
 767                  * Sec-WebSocket-Protocol: chat, superchat
 768                  * Sec-WebSocket-Version: 4
 769                  */
 770
 771                  p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 772                  p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 773                  p += sprintf(p, "Upgrade: websocket\x0d\x0a");
 774                  p += sprintf(p, "Connection: Upgrade\x0d\x0a"
 775                                         "Sec-WebSocket-Key: ");
 776                  strcpy(p, wsi->key_b64);
 777                  p += strlen(wsi->key_b64);
 778                  p += sprintf(p, "\x0d\x0aSec-WebSocket-Origin: %s\x0d\x0a",
 779                                                                  wsi->c_origin);
 780                  if (wsi->c_protocol != NULL)
 781                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 782                                                                wsi->c_protocol);
 783                  p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a",
 784                                                        wsi->ietf_spec_revision);
 785
 786                 /* done with these now */
 787
 788                 free(wsi->c_path);
 789                 free(wsi->c_host);
 790                 free(wsi->c_origin);
 791
 792                 /* prepare the expected server accept response */
 793
 794                 strcpy((char *)buf, wsi->key_b64);
 795                 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 796
 797                 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 798
 799                 lws_b64_encode_string(hash, 20,
 800                                 wsi->initial_handshake_hash_base64,
 801                                      sizeof wsi->initial_handshake_hash_base64);
 802
 803                 /* send our request to the server */
 804
 805         #ifdef LWS_OPENSSL_SUPPORT
 806                 if (wsi->use_ssl)
 807                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 808                 else
 809         #endif
 810                         n = send(wsi->sock, pkt, p - pkt, 0);
 811
 812                 if (n < 0) {
 813                         fprintf(stderr, "ERROR writing to client socket\n");
 814                         libwebsocket_close_and_free_session(this, wsi);
 815                         return 1;
 816                 }
 817
 818                 wsi->parser_state = WSI_TOKEN_NAME_PART;
 819                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 820                 libwebsocket_set_timeout(wsi,
 821                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, 5);
 822
 823                 break;
 824
 825         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 826
 827                 /* handle server hung up on us */
 828
 829                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 830
 831                         fprintf(stderr, "Server connection %p (fd=%d) dead\n",
 832                                 (void *)wsi, pollfd->fd);
 833
 834                         goto bail3;
 835                 }
 836
 837
 838                 /* interpret the server response */
 839
 840                 /*
 841                  *  HTTP/1.1 101 Switching Protocols
 842                  *  Upgrade: websocket
 843                  *  Connection: Upgrade
 844                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 845                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 846                  *  Sec-WebSocket-Protocol: chat
 847                  */
 848
 849         #ifdef LWS_OPENSSL_SUPPORT
 850                 if (wsi->use_ssl)
 851                         len = SSL_read(wsi->ssl, pkt, sizeof pkt);
 852                 else
 853         #endif
 854                         len = recv(wsi->sock, pkt, sizeof pkt, 0);
 855
 856                 if (len < 0) {
 857                         fprintf(stderr,
 858                                   "libwebsocket_client_handshake read error\n");
 859                         goto bail3;
 860                 }
 861
 862                 p = pkt;
 863                 for (n = 0; n < len; n++)
 864                         libwebsocket_parse(wsi, *p++);
 865
 866                 if (wsi->parser_state != WSI_PARSING_COMPLETE) {
 867                         fprintf(stderr, "libwebsocket_client_handshake "
 868                                         "server response ailed parsing\n");
 869                         goto bail3;
 870                 }
 871
 872                 /*
 873                  * well, what the server sent looked reasonable for syntax.
 874                  * Now let's confirm it sent all the necessary headers
 875                  */
 876
 877                  if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 878                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 879                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 880                         !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 881                         !wsi->utf8_token[WSI_TOKEN_NONCE].token_len ||
 882                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
 883                                                      wsi->c_protocol != NULL)) {
 884                         fprintf(stderr, "libwebsocket_client_handshake "
 885                                                         "missing required header(s)\n");
 886                         pkt[len] = '\0';
 887                         fprintf(stderr, "%s", pkt);
 888                         goto bail3;
 889                 }
 890
 891                 /*
 892                  * Everything seems to be there, now take a closer look at what
 893                  * is in each header
 894                  */
 895
 896                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 897                 if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
 898                                                    "101 switching protocols")) {
 899                         fprintf(stderr, "libwebsocket_client_handshake "
 900                                         "server sent bad HTTP response '%s'\n",
 901                                          wsi->utf8_token[WSI_TOKEN_HTTP].token);
 902                         goto bail3;
 903                 }
 904
 905                 strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 906                 if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 907                                                                  "websocket")) {
 908                         fprintf(stderr, "libwebsocket_client_handshake server "
 909                                         "sent bad Upgrade header '%s'\n",
 910                                       wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 911                         goto bail3;
 912                 }
 913
 914                 strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 915                 if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 916                                                                    "upgrade")) {
 917                         fprintf(stderr, "libwebsocket_client_handshake server "
 918                                         "sent bad Connection hdr '%s'\n",
 919                                    wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 920                         goto bail3;
 921                 }
 922
 923
 924                 pc = wsi->c_protocol;
 925
 926                 /*
 927                  * confirm the protocol the server wants to talk was in the list
 928                  * of protocols we offered
 929                  */
 930
 931                 if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 932
 933                         /*
 934                          * no protocol name to work from,
 935                          * default to first protocol
 936                          */
 937                         wsi->protocol = &this->protocols[0];
 938
 939                         free(wsi->c_protocol);
 940
 941                         goto check_accept;
 942                 }
 943
 944                 while (*pc && !okay) {
 945                         if ((!strncmp(pc,
 946                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 947                            wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 948                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 949                    pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 950                                 okay = 1;
 951                                 continue;
 952                         }
 953                         while (*pc && *pc != ',')
 954                                 pc++;
 955                         while (*pc && *pc != ' ')
 956                                 pc++;
 957                 }
 958
 959                 /* done with him now */
 960
 961                 if (wsi->c_protocol)
 962                         free(wsi->c_protocol);
 963
 964
 965                 if (!okay) {
 966                         fprintf(stderr, "libwebsocket_client_handshake server "
 967                                                 "sent bad protocol '%s'\n",
 968                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 969                         goto bail2;
 970                 }
 971
 972                 /*
 973                  * identify the selected protocol struct and set it
 974                  */
 975                 n = 0;
 976                 wsi->protocol = NULL;
 977                 while (this->protocols[n].callback) {
 978                         if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 979                                                this->protocols[n].name) == 0)
 980                                 wsi->protocol = &this->protocols[n];
 981                         n++;
 982                 }
 983
 984                 if (wsi->protocol == NULL) {
 985                         fprintf(stderr, "libwebsocket_client_handshake server "
 986                                         "requested protocol '%s', which we "
 987                                         "said we supported but we don't!\n",
 988                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 989                         goto bail2;
 990                 }
 991
 992         check_accept:
 993                 /*
 994                  * Confirm his accept token is the one we precomputed
 995                  */
 996
 997                 if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 998                                           wsi->initial_handshake_hash_base64)) {
 999                         fprintf(stderr, "libwebsocket_client_handshake server "
1000                                 "sent bad ACCEPT '%s' vs computed '%s'\n",
1001                                 wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1002                                             wsi->initial_handshake_hash_base64);
1003                         goto bail2;
1004                 }
1005
1006                 /*
1007                  * Calculate the masking key to use when sending data to server
1008                  */
1009
1010                 strcpy((char *)buf, wsi->key_b64);
1011                 p = (char *)buf + strlen(wsi->key_b64);
1012                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1013                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1014                 strcpy(p, magic_websocket_04_masking_guid);
1015                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1016
1017                 /* allocate the per-connection user memory (if any) */
1018
1019                 if (wsi->protocol->per_session_data_size) {
1020                         wsi->user_space = malloc(
1021                                           wsi->protocol->per_session_data_size);
1022                         if (wsi->user_space  == NULL) {
1023                                 fprintf(stderr, "Out of memory for "
1024                                                            "conn user space\n");
1025                                 goto bail2;
1026                         }
1027                 } else
1028                         wsi->user_space = NULL;
1029
1030                 /* clear his proxy connection timeout */
1031
1032                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1033
1034                 /* mark him as being alive */
1035
1036                 wsi->state = WSI_STATE_ESTABLISHED;
1037                 wsi->mode = LWS_CONNMODE_WS_CLIENT;
1038
1039                 fprintf(stderr, "handshake OK for protocol %s\n",
1040                                                            wsi->protocol->name);
1041
1042                 /* call him back to inform him he is up */
1043
1044                 wsi->protocol->callback(this, wsi,
1045                                  LWS_CALLBACK_CLIENT_ESTABLISHED,
1046                                  wsi->user_space,
1047                                  NULL, 0);
1048
1049                 break;
1050
1051 bail3:
1052                 if (wsi->c_protocol)
1053                         free(wsi->c_protocol);
1054
1055 bail2:
1056                 libwebsocket_close_and_free_session(this, wsi);
1057                 return 1;
1058
1059
1060         case LWS_CONNMODE_WS_SERVING:
1061         case LWS_CONNMODE_WS_CLIENT:
1062
1063                 /* handle session socket closed */
1064
1065                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1066
1067                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1068                                 (void *)wsi, pollfd->fd);
1069
1070                         libwebsocket_close_and_free_session(this, wsi);
1071                         return 1;
1072                 }
1073
1074                 /* the guy requested a callback when it was OK to write */
1075
1076                 if (pollfd->revents & POLLOUT) {
1077
1078                         pollfd->events &= ~POLLOUT;
1079
1080                         /* external POLL support via protocol 0 */
1081                         this->protocols[0].callback(this, wsi,
1082                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1083                                 (void *)(long)wsi->sock, NULL, POLLOUT);
1084
1085                         wsi->protocol->callback(this, wsi,
1086                                 LWS_CALLBACK_CLIENT_WRITEABLE,
1087                                 wsi->user_space,
1088                                 NULL, 0);
1089                 }
1090
1091                 /* any incoming data ready? */
1092
1093                 if (!(pollfd->revents & POLLIN))
1094                         break;
1095
1096 #ifdef LWS_OPENSSL_SUPPORT
1097                 if (wsi->ssl)
1098                         n = SSL_read(wsi->ssl, buf, sizeof buf);
1099                 else
1100 #endif
1101                         n = recv(pollfd->fd, buf, sizeof buf, 0);
1102
1103                 if (n < 0) {
1104                         fprintf(stderr, "Socket read returned %d\n", n);
1105                         break;
1106                 }
1107                 if (!n) {
1108                         libwebsocket_close_and_free_session(this, wsi);
1109                         return 1;
1110                 }
1111
1112                 /* service incoming data */
1113
1114                 n = libwebsocket_read(this, wsi, buf, n);
1115                 if (n >= 0)
1116                         break;
1117
1118                 /* we closed wsi */
1119
1120                 return 1;
1121         }
1122
1123         return 0;
1124 }
1125
1126
1127 /**
1128  * libwebsocket_context_destroy() - Destroy the websocket context
1129  * @this:       Websocket context
1130  *
1131  *      This function closes any active connections and then frees the
1132  *      context.  After calling this, any further use of the context is
1133  *      undefined.
1134  */
1135 void
1136 libwebsocket_context_destroy(struct libwebsocket_context *this)
1137 {
1138         int n;
1139         int m;
1140         struct libwebsocket *wsi;
1141
1142         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1143                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1144                         wsi = this->fd_hashtable[n].wsi[m];
1145                         libwebsocket_close_and_free_session(this, wsi);
1146                 }
1147
1148         close(this->fd_random);
1149
1150 #ifdef LWS_OPENSSL_SUPPORT
1151         if (this->ssl_ctx)
1152                 SSL_CTX_free(this->ssl_ctx);
1153         if (this->ssl_client_ctx)
1154                 SSL_CTX_free(this->ssl_client_ctx);
1155 #endif
1156
1157         free(this);
1158 }
1159
1160 /**
1161  * libwebsocket_service() - Service any pending websocket activity
1162  * @this:       Websocket context
1163  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
1164  *              service otherwise block and service immediately, returning
1165  *              after the timeout if nothing needed service.
1166  *
1167  *      This function deals with any pending websocket traffic, for three
1168  *      kinds of event.  It handles these events on both server and client
1169  *      types of connection the same.
1170  *
1171  *      1) Accept new connections to our context's server
1172  *
1173  *      2) Perform pending broadcast writes initiated from other forked
1174  *         processes (effectively serializing asynchronous broadcasts)
1175  *
1176  *      3) Call the receive callback for incoming frame data received by
1177  *          server or client connections.
1178  *
1179  *      You need to call this service function periodically to all the above
1180  *      functions to happen; if your application is single-threaded you can
1181  *      just call it in your main event loop.
1182  *
1183  *      Alternatively you can fork a new process that asynchronously handles
1184  *      calling this service in a loop.  In that case you are happy if this
1185  *      call blocks your thread until it needs to take care of something and
1186  *      would call it with a large nonzero timeout.  Your loop then takes no
1187  *      CPU while there is nothing happening.
1188  *
1189  *      If you are calling it in a single-threaded app, you don't want it to
1190  *      wait around blocking other things in your loop from happening, so you
1191  *      would call it with a timeout_ms of 0, so it returns immediately if
1192  *      nothing is pending, or as soon as it services whatever was pending.
1193  */
1194
1195
1196 int
1197 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
1198 {
1199         int n;
1200
1201         /* stay dead once we are dead */
1202
1203         if (this == NULL)
1204                 return 1;
1205
1206         /* wait for something to need service */
1207
1208         n = poll(this->fds, this->fds_count, timeout_ms);
1209         if (n == 0) /* poll timeout */
1210                 return 0;
1211
1212         if (n < 0) {
1213                 /*
1214                 fprintf(stderr, "Listen Socket dead\n");
1215                 */
1216                 return 1;
1217         }
1218
1219         /* handle accept on listening socket? */
1220
1221         for (n = 0; n < this->fds_count; n++)
1222                 if (this->fds[n].revents)
1223                         libwebsocket_service_fd(this, &this->fds[n]);
1224
1225         return 0;
1226 }
1227
1228 /**
1229  * libwebsocket_callback_on_writable() - Request a callback when this socket
1230  *                                       becomes able to be written to without
1231  *                                       blocking
1232  *
1233  * @this:       libwebsockets context
1234  * @wsi:        Websocket connection instance to get callback for
1235  */
1236
1237 int
1238 libwebsocket_callback_on_writable(struct libwebsocket_context *this,
1239                                                        struct libwebsocket *wsi)
1240 {
1241         int n;
1242
1243         for (n = 0; n < this->fds_count; n++)
1244                 if (this->fds[n].fd == wsi->sock) {
1245                         this->fds[n].events |= POLLOUT;
1246                         n = this->fds_count;
1247                 }
1248
1249         /* external POLL support via protocol 0 */
1250         this->protocols[0].callback(this, wsi,
1251                 LWS_CALLBACK_SET_MODE_POLL_FD,
1252                 (void *)(long)wsi->sock, NULL, POLLOUT);
1253
1254         return 1;
1255 }
1256
1257 /**
1258  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
1259  *                      all connections using the given protocol when it
1260  *                      becomes possible to write to each socket without
1261  *                      blocking in turn.
1262  *
1263  * @protocol:   Protocol whose connections will get callbacks
1264  */
1265
1266 int
1267 libwebsocket_callback_on_writable_all_protocol(
1268                                   const struct libwebsocket_protocols *protocol)
1269 {
1270         struct libwebsocket_context *this = protocol->owning_server;
1271         int n;
1272         int m;
1273         struct libwebsocket *wsi;
1274
1275         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1276
1277                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1278
1279                         wsi = this->fd_hashtable[n].wsi[m];
1280
1281                         if (wsi->protocol == protocol)
1282                                 libwebsocket_callback_on_writable(this, wsi);
1283                 }
1284         }
1285
1286         return 0;
1287 }
1288
1289 /**
1290  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
1291  *
1292  * You will not need this unless you are doing something special
1293  *
1294  * @wsi:        Websocket connection instance
1295  * @reason:     timeout reason
1296  * @secs:       how many seconds
1297  */
1298
1299 void
1300 libwebsocket_set_timeout(struct libwebsocket *wsi,
1301                                           enum pending_timeout reason, int secs)
1302 {
1303         struct timeval tv;
1304
1305         gettimeofday(&tv, NULL);
1306
1307         wsi->pending_timeout_limit = tv.tv_sec + secs;
1308         wsi->pending_timeout = reason;
1309 }
1310
1311
1312 /**
1313  * libwebsocket_get_socket_fd() - returns the socket file descriptor
1314  *
1315  * You will not need this unless you are doing something special
1316  *
1317  * @wsi:        Websocket connection instance
1318  */
1319
1320 int
1321 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
1322 {
1323         return wsi->sock;
1324 }
1325
1326 /**
1327  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
1328  *                              receieved packets.
1329  *
1330  * If the output side of a server process becomes choked, this allows flow
1331  * control for the input side.
1332  *
1333  * @wsi:        Websocket connection instance to get callback for
1334  * @enable:     0 = disable read servicing for this connection, 1 = enable
1335  */
1336
1337 int
1338 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
1339 {
1340         struct libwebsocket_context *this = wsi->protocol->owning_server;
1341         int n;
1342
1343         for (n = 0; n < this->fds_count; n++)
1344                 if (this->fds[n].fd == wsi->sock) {
1345                         if (enable)
1346                                 this->fds[n].events |= POLLIN;
1347                         else
1348                                 this->fds[n].events &= ~POLLIN;
1349
1350                         return 0;
1351                 }
1352
1353         if (enable)
1354                 /* external POLL support via protocol 0 */
1355                 this->protocols[0].callback(this, wsi,
1356                         LWS_CALLBACK_SET_MODE_POLL_FD,
1357                         (void *)(long)wsi->sock, NULL, POLLIN);
1358         else
1359                 /* external POLL support via protocol 0 */
1360                 this->protocols[0].callback(this, wsi,
1361                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1362                         (void *)(long)wsi->sock, NULL, POLLIN);
1363
1364
1365         fprintf(stderr, "libwebsocket_callback_on_writable "
1366                                                      "unable to find socket\n");
1367         return 1;
1368 }
1369
1370 /**
1371  * libwebsocket_canonical_hostname() - returns this host's hostname
1372  *
1373  * This is typically used by client code to fill in the host parameter
1374  * when making a client connection.  You can only call it after the context
1375  * has been created.
1376  *
1377  * @this:       Websocket context
1378  */
1379
1380
1381 extern const char *
1382 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
1383 {
1384         return (const char *)this->canonical_hostname;
1385 }
1386
1387
1388 static void sigpipe_handler(int x)
1389 {
1390 }
1391
1392
1393 /**
1394  * libwebsocket_create_context() - Create the websocket handler
1395  * @port:       Port to listen on... you can use 0 to suppress listening on
1396  *              any port, that's what you want if you are not running a
1397  *              websocket server at all but just using it as a client
1398  * @interface:  NULL to bind the listen socket to all interfaces, or the
1399  *              interface name, eg, "eth2"
1400  * @protocols:  Array of structures listing supported protocols and a protocol-
1401  *              specific callback for each one.  The list is ended with an
1402  *              entry that has a NULL callback pointer.
1403  *              It's not const because we write the owning_server member
1404  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
1405  *                      to listen using SSL, set to the filepath to fetch the
1406  *                      server cert from, otherwise NULL for unencrypted
1407  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
1408  *                      else ignored
1409  * @gid:        group id to change to after setting listen socket, or -1.
1410  * @uid:        user id to change to after setting listen socket, or -1.
1411  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
1412  *
1413  *      This function creates the listening socket and takes care
1414  *      of all initialization in one step.
1415  *
1416  *      After initialization, it returns a struct libwebsocket_context * that
1417  *      represents this server.  After calling, user code needs to take care
1418  *      of calling libwebsocket_service() with the context pointer to get the
1419  *      server's sockets serviced.  This can be done in the same process context
1420  *      or a forked process, or another thread,
1421  *
1422  *      The protocol callback functions are called for a handful of events
1423  *      including http requests coming in, websocket connections becoming
1424  *      established, and data arriving; it's also called periodically to allow
1425  *      async transmission.
1426  *
1427  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
1428  *      at that time websocket protocol has not been negotiated.  Other
1429  *      protocols after the first one never see any HTTP callack activity.
1430  *
1431  *      The server created is a simple http server by default; part of the
1432  *      websocket standard is upgrading this http connection to a websocket one.
1433  *
1434  *      This allows the same server to provide files like scripts and favicon /
1435  *      images or whatever over http and dynamic data over websockets all in
1436  *      one place; they're all handled in the user callback.
1437  */
1438
1439 struct libwebsocket_context *
1440 libwebsocket_create_context(int port, const char *interface,
1441                                struct libwebsocket_protocols *protocols,
1442                                const char *ssl_cert_filepath,
1443                                const char *ssl_private_key_filepath,
1444                                int gid, int uid, unsigned int options)
1445 {
1446         int n;
1447         int sockfd = 0;
1448         int fd;
1449         struct sockaddr_in serv_addr, cli_addr;
1450         int opt = 1;
1451         struct libwebsocket_context *this = NULL;
1452         unsigned int slen;
1453         char *p;
1454         char hostname[1024];
1455         struct hostent *he;
1456         struct libwebsocket *wsi;
1457
1458 #ifdef LWS_OPENSSL_SUPPORT
1459         SSL_METHOD *method;
1460         char ssl_err_buf[512];
1461 #endif
1462
1463         this = malloc(sizeof(struct libwebsocket_context));
1464         if (!this) {
1465                 fprintf(stderr, "No memory for websocket context\n");
1466                 return NULL;
1467         }
1468         this->protocols = protocols;
1469         this->listen_port = port;
1470         this->http_proxy_port = 0;
1471         this->http_proxy_address[0] = '\0';
1472         this->options = options;
1473         this->fds_count = 0;
1474
1475         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
1476         if (this->fd_random < 0) {
1477                 fprintf(stderr, "Unable to open random device %s %d\n",
1478                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
1479                 return NULL;
1480         }
1481
1482         /* find canonical hostname */
1483
1484         hostname[(sizeof hostname) - 1] = '\0';
1485         gethostname(hostname, (sizeof hostname) - 1);
1486         he = gethostbyname(hostname);
1487         if (he) {
1488                 strncpy(this->canonical_hostname, he->h_name,
1489                                            sizeof this->canonical_hostname - 1);
1490                 this->canonical_hostname[sizeof this->canonical_hostname - 1] =
1491                                                                            '\0';
1492         } else
1493                 strncpy(this->canonical_hostname, hostname,
1494                                            sizeof this->canonical_hostname - 1);
1495
1496         /* split the proxy ads:port if given */
1497
1498         p = getenv("http_proxy");
1499         if (p) {
1500                 strncpy(this->http_proxy_address, p,
1501                                            sizeof this->http_proxy_address - 1);
1502                 this->http_proxy_address[
1503                                     sizeof this->http_proxy_address - 1] = '\0';
1504
1505                 p = strchr(this->http_proxy_address, ':');
1506                 if (p == NULL) {
1507                         fprintf(stderr, "http_proxy needs to be ads:port\n");
1508                         return NULL;
1509                 }
1510                 *p = '\0';
1511                 this->http_proxy_port = atoi(p + 1);
1512
1513                 fprintf(stderr, "Using proxy %s:%u\n",
1514                                 this->http_proxy_address,
1515                                                         this->http_proxy_port);
1516         }
1517
1518         if (port) {
1519
1520 #ifdef LWS_OPENSSL_SUPPORT
1521                 this->use_ssl = ssl_cert_filepath != NULL &&
1522                                                ssl_private_key_filepath != NULL;
1523                 if (this->use_ssl)
1524                         fprintf(stderr, " Compiled with SSL support, "
1525                                                                   "using it\n");
1526                 else
1527                         fprintf(stderr, " Compiled with SSL support, "
1528                                                               "not using it\n");
1529
1530 #else
1531                 if (ssl_cert_filepath != NULL &&
1532                                              ssl_private_key_filepath != NULL) {
1533                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
1534                         return NULL;
1535                 }
1536                 fprintf(stderr, " Compiled without SSL support, "
1537                                                        "serving unencrypted\n");
1538 #endif
1539         }
1540
1541         /* ignore SIGPIPE */
1542
1543         signal(SIGPIPE, sigpipe_handler);
1544
1545
1546 #ifdef LWS_OPENSSL_SUPPORT
1547
1548         /* basic openssl init */
1549
1550         SSL_library_init();
1551
1552         OpenSSL_add_all_algorithms();
1553         SSL_load_error_strings();
1554
1555         /*
1556          * Firefox insists on SSLv23 not SSLv3
1557          * Konq disables SSLv2 by default now, SSLv23 works
1558          */
1559
1560         method = (SSL_METHOD *)SSLv23_server_method();
1561         if (!method) {
1562                 fprintf(stderr, "problem creating ssl method: %s\n",
1563                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1564                 return NULL;
1565         }
1566         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
1567         if (!this->ssl_ctx) {
1568                 fprintf(stderr, "problem creating ssl context: %s\n",
1569                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1570                 return NULL;
1571         }
1572
1573         /* client context */
1574
1575         method = (SSL_METHOD *)SSLv23_client_method();
1576         if (!method) {
1577                 fprintf(stderr, "problem creating ssl method: %s\n",
1578                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1579                 return NULL;
1580         }
1581         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
1582         if (!this->ssl_client_ctx) {
1583                 fprintf(stderr, "problem creating ssl context: %s\n",
1584                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1585                 return NULL;
1586         }
1587
1588
1589         /* openssl init for cert verification (used with client sockets) */
1590
1591         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
1592                                                     LWS_OPENSSL_CLIENT_CERTS)) {
1593                 fprintf(stderr, "Unable to load SSL Client certs from %s "
1594                         "(set by --with-client-cert-dir= in configure) -- "
1595                         " client ssl isn't going to work",
1596                                                       LWS_OPENSSL_CLIENT_CERTS);
1597         }
1598
1599         if (this->use_ssl) {
1600
1601                 /* openssl init for server sockets */
1602
1603                 /* set the local certificate from CertFile */
1604                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
1605                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
1606                 if (n != 1) {
1607                         fprintf(stderr, "problem getting cert '%s': %s\n",
1608                                 ssl_cert_filepath,
1609                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1610                         return NULL;
1611                 }
1612                 /* set the private key from KeyFile */
1613                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
1614                                                 ssl_private_key_filepath,
1615                                                        SSL_FILETYPE_PEM) != 1) {
1616                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
1617                                                 ssl_private_key_filepath,
1618                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1619                         return NULL;
1620                 }
1621                 /* verify private key */
1622                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
1623                         fprintf(stderr, "Private SSL key doesn't match cert\n");
1624                         return NULL;
1625                 }
1626
1627                 /* SSL is happy and has a cert it's content with */
1628         }
1629 #endif
1630
1631         /* selftest */
1632
1633         if (lws_b64_selftest())
1634                 return NULL;
1635
1636         /* fd hashtable init */
1637
1638         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1639                 this->fd_hashtable[n].length = 0;
1640
1641         /* set up our external listening socket we serve on */
1642
1643         if (port) {
1644
1645                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1646                 if (sockfd < 0) {
1647                         fprintf(stderr, "ERROR opening socket");
1648                         return NULL;
1649                 }
1650
1651                 /* allow us to restart even if old sockets in TIME_WAIT */
1652                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1653
1654                 bzero((char *) &serv_addr, sizeof(serv_addr));
1655                 serv_addr.sin_family = AF_INET;
1656                 if (interface == NULL)
1657                         serv_addr.sin_addr.s_addr = INADDR_ANY;
1658                 else
1659                         interface_to_sa(interface, &serv_addr,
1660                                                 sizeof(serv_addr));
1661                 serv_addr.sin_port = htons(port);
1662
1663                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
1664                                                              sizeof(serv_addr));
1665                 if (n < 0) {
1666                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1667                                                                 port, n, errno);
1668                         return NULL;
1669                 }
1670
1671                 wsi = malloc(sizeof(struct libwebsocket));
1672                 memset(wsi, 0, sizeof (struct libwebsocket));
1673                 wsi->sock = sockfd;
1674                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
1675                 insert_wsi(this, wsi);
1676
1677                 listen(sockfd, 5);
1678                 fprintf(stderr, " Listening on port %d\n", port);
1679
1680                 /* list in the internal poll array */
1681
1682                 this->fds[this->fds_count].fd = sockfd;
1683                 this->fds[this->fds_count++].events = POLLIN;
1684
1685                 /* external POLL support via protocol 0 */
1686                 this->protocols[0].callback(this, wsi,
1687                         LWS_CALLBACK_ADD_POLL_FD,
1688                         (void *)(long)sockfd, NULL, POLLIN);
1689
1690         }
1691
1692         /* drop any root privs for this process */
1693
1694         if (gid != -1)
1695                 if (setgid(gid))
1696                         fprintf(stderr, "setgid: %s\n", strerror(errno));
1697         if (uid != -1)
1698                 if (setuid(uid))
1699                         fprintf(stderr, "setuid: %s\n", strerror(errno));
1700
1701
1702         /* set up our internal broadcast trigger sockets per-protocol */
1703
1704         for (this->count_protocols = 0;
1705                         protocols[this->count_protocols].callback;
1706                                                       this->count_protocols++) {
1707                 protocols[this->count_protocols].owning_server = this;
1708                 protocols[this->count_protocols].protocol_index =
1709                                                           this->count_protocols;
1710
1711                 fd = socket(AF_INET, SOCK_STREAM, 0);
1712                 if (fd < 0) {
1713                         fprintf(stderr, "ERROR opening socket");
1714                         return NULL;
1715                 }
1716
1717                 /* allow us to restart even if old sockets in TIME_WAIT */
1718                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1719
1720                 bzero((char *) &serv_addr, sizeof(serv_addr));
1721                 serv_addr.sin_family = AF_INET;
1722                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1723                 serv_addr.sin_port = 0; /* pick the port for us */
1724
1725                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
1726                 if (n < 0) {
1727                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1728                                                                 port, n, errno);
1729                         return NULL;
1730                 }
1731
1732                 slen = sizeof cli_addr;
1733                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
1734                 if (n < 0) {
1735                         fprintf(stderr, "getsockname failed\n");
1736                         return NULL;
1737                 }
1738                 protocols[this->count_protocols].broadcast_socket_port =
1739                                                        ntohs(cli_addr.sin_port);
1740                 listen(fd, 5);
1741
1742                 debug("  Protocol %s broadcast socket %d\n",
1743                                 protocols[this->count_protocols].name,
1744                                                       ntohs(cli_addr.sin_port));
1745
1746                 /* dummy wsi per broadcast proxy socket */
1747
1748                 wsi = malloc(sizeof(struct libwebsocket));
1749                 memset(wsi, 0, sizeof (struct libwebsocket));
1750                 wsi->sock = fd;
1751                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
1752                 /* note which protocol we are proxying */
1753                 wsi->protocol_index_for_broadcast_proxy = this->count_protocols;
1754                 insert_wsi(this, wsi);
1755
1756                 /* list in internal poll array */
1757
1758                 this->fds[this->fds_count].fd = fd;
1759                 this->fds[this->fds_count].events = POLLIN;
1760                 this->fds[this->fds_count].revents = 0;
1761                 this->fds_count++;
1762
1763                 /* external POLL support via protocol 0 */
1764                 this->protocols[0].callback(this, wsi,
1765                         LWS_CALLBACK_ADD_POLL_FD,
1766                         (void *)(long)fd, NULL, POLLIN);
1767         }
1768
1769         return this;
1770 }
1771
1772
1773 #ifndef LWS_NO_FORK
1774
1775 /**
1776  * libwebsockets_fork_service_loop() - Optional helper function forks off
1777  *                                a process for the websocket server loop.
1778  *                              You don't have to use this but if not, you
1779  *                              have to make sure you are calling
1780  *                              libwebsocket_service periodically to service
1781  *                              the websocket traffic
1782  * @this:       server context returned by creation function
1783  */
1784
1785 int
1786 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
1787 {
1788         int fd;
1789         struct sockaddr_in cli_addr;
1790         int n;
1791         int p;
1792
1793         n = fork();
1794         if (n < 0)
1795                 return n;
1796
1797         if (!n) {
1798
1799                 /* main process context */
1800
1801                 /*
1802                  * set up the proxy sockets to allow broadcast from
1803                  * service process context
1804                  */
1805
1806                 for (p = 0; p < this->count_protocols; p++) {
1807                         fd = socket(AF_INET, SOCK_STREAM, 0);
1808                         if (fd < 0) {
1809                                 fprintf(stderr, "Unable to create socket\n");
1810                                 return -1;
1811                         }
1812                         cli_addr.sin_family = AF_INET;
1813                         cli_addr.sin_port = htons(
1814                              this->protocols[p].broadcast_socket_port);
1815                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1816                         n = connect(fd, (struct sockaddr *)&cli_addr,
1817                                                                sizeof cli_addr);
1818                         if (n < 0) {
1819                                 fprintf(stderr, "Unable to connect to "
1820                                                 "broadcast socket %d, %s\n",
1821                                                 n, strerror(errno));
1822                                 return -1;
1823                         }
1824
1825                         this->protocols[p].broadcast_socket_user_fd = fd;
1826                 }
1827
1828                 return 0;
1829         }
1830
1831         /* we want a SIGHUP when our parent goes down */
1832         prctl(PR_SET_PDEATHSIG, SIGHUP);
1833
1834         /* in this forked process, sit and service websocket connections */
1835
1836         while (1)
1837                 if (libwebsocket_service(this, 1000))
1838                         return -1;
1839
1840         return 0;
1841 }
1842
1843 #endif
1844
1845 /**
1846  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1847  *                                connection.
1848  * @wsi:        pointer to struct websocket you want to know the protocol of
1849  *
1850  *
1851  *      This is useful to get the protocol to broadcast back to from inside
1852  * the callback.
1853  */
1854
1855 const struct libwebsocket_protocols *
1856 libwebsockets_get_protocol(struct libwebsocket *wsi)
1857 {
1858         return wsi->protocol;
1859 }
1860
1861 /**
1862  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1863  *                                connections of the given protocol.
1864  * @protocol:   pointer to the protocol you will broadcast to all members of
1865  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1866  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1867  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1868  *              case you are calling this function from callback context.
1869  * @len:        length of payload data in buf, starting from buf.
1870  *
1871  *      This function allows bulk sending of a packet to every connection using
1872  * the given protocol.  It does not send the data directly; instead it calls
1873  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1874  * wants to actually send the data for that connection, the callback itself
1875  * should call libwebsocket_write().
1876  *
1877  * libwebsockets_broadcast() can be called from another fork context without
1878  * having to take any care about data visibility between the processes, it'll
1879  * "just work".
1880  */
1881
1882
1883 int
1884 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1885                                                  unsigned char *buf, size_t len)
1886 {
1887         struct libwebsocket_context *this = protocol->owning_server;
1888         int n;
1889         int m;
1890         struct libwebsocket * wsi;
1891
1892         if (!protocol->broadcast_socket_user_fd) {
1893                 /*
1894                  * We are either running unforked / flat, or we are being
1895                  * called from poll thread context
1896                  * eg, from a callback.  In that case don't use sockets for
1897                  * broadcast IPC (since we can't open a socket connection to
1898                  * a socket listening on our own thread) but directly do the
1899                  * send action.
1900                  *
1901                  * Locking is not needed because we are by definition being
1902                  * called in the poll thread context and are serialized.
1903                  */
1904
1905                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1906
1907                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
1908
1909                                 wsi = this->fd_hashtable[n].wsi[m];
1910
1911                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
1912                                         continue;
1913
1914                                 /*
1915                                  * never broadcast to
1916                                  * non-established connections
1917                                  */
1918                                 if (wsi->state != WSI_STATE_ESTABLISHED)
1919                                         continue;
1920
1921                                 /* only broadcast to guys using
1922                                  * requested protocol
1923                                  */
1924                                 if (wsi->protocol != protocol)
1925                                         continue;
1926
1927                                 wsi->protocol->callback(this, wsi,
1928                                          LWS_CALLBACK_BROADCAST,
1929                                          wsi->user_space,
1930                                          buf, len);
1931                         }
1932                 }
1933
1934                 return 0;
1935         }
1936
1937         /*
1938          * We're being called from a different process context than the server
1939          * loop.  Instead of broadcasting directly, we send our
1940          * payload on a socket to do the IPC; the server process will serialize
1941          * the broadcast action in its main poll() loop.
1942          *
1943          * There's one broadcast socket listening for each protocol supported
1944          * set up when the websocket server initializes
1945          */
1946
1947         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
1948
1949         return n;
1950 }