lib/libwebsockets.c

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