lib/libwebsockets.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23 #include <ifaddrs.h>
  24
  25 /*
  26  * In-place str to lower case
  27  */
  28
  29 static void
  30 strtolower(char *s)
  31 {
  32         while (*s) {
  33                 *s = tolower(*s);
  34                 s++;
  35         }
  36 }
  37
  38 /* file descriptor hash management */
  39
  40 struct libwebsocket *
  41 wsi_from_fd(struct libwebsocket_context *this, int fd)
  42 {
  43         int h = LWS_FD_HASH(fd);
  44         int n = 0;
  45
  46         for (n = 0; n < this->fd_hashtable[h].length; n++)
  47                 if (this->fd_hashtable[h].wsi[n]->sock == fd)
  48                         return this->fd_hashtable[h].wsi[n];
  49
  50         return NULL;
  51 }
  52
  53 int
  54 insert_wsi(struct libwebsocket_context *this, struct libwebsocket *wsi)
  55 {
  56         int h = LWS_FD_HASH(wsi->sock);
  57
  58         if (this->fd_hashtable[h].length == MAX_CLIENTS - 1) {
  59                 fprintf(stderr, "hash table overflow\n");
  60                 return 1;
  61         }
  62
  63         this->fd_hashtable[h].wsi[this->fd_hashtable[h].length++] = wsi;
  64
  65         return 0;
  66 }
  67
  68 int
  69 delete_from_fd(struct libwebsocket_context *this, int fd)
  70 {
  71         int h = LWS_FD_HASH(fd);
  72         int n = 0;
  73
  74         for (n = 0; n < this->fd_hashtable[h].length; n++)
  75                 if (this->fd_hashtable[h].wsi[n]->sock == fd) {
  76                         while (n < this->fd_hashtable[h].length) {
  77                                 this->fd_hashtable[h].wsi[n] =
  78                                                this->fd_hashtable[h].wsi[n + 1];
  79                                 n++;
  80                         }
  81                         this->fd_hashtable[h].length--;
  82
  83                         return 0;
  84                 }
  85
  86         fprintf(stderr, "Failed to find fd %d requested for "
  87                                                    "delete in hashtable\n", fd);
  88         return 1;
  89 }
  90
  91 #ifdef LWS_OPENSSL_SUPPORT
  92 static void
  93 libwebsockets_decode_ssl_error(void)
  94 {
  95         char buf[256];
  96         u_long err;
  97
  98         while ((err = ERR_get_error()) != 0) {
  99                 ERR_error_string_n(err, buf, sizeof(buf));
 100                 fprintf(stderr, "*** %s\n", buf);
 101         }
 102 }
 103 #endif
 104
 105
 106 static int
 107 interface_to_sa(const char* ifname, struct sockaddr_in *addr, size_t addrlen)
 108 {
 109         int rc = -1;
 110         struct ifaddrs *ifr;
 111         struct ifaddrs *ifc;
 112         struct sockaddr_in *sin;
 113
 114         getifaddrs(&ifr);
 115         for (ifc = ifr; ifc != NULL; ifc = ifc->ifa_next) {
 116                 if (strcmp(ifc->ifa_name, ifname))
 117                         continue;
 118                 if (ifc->ifa_addr == NULL)
 119                         continue;
 120                 sin = (struct sockaddr_in *)ifc->ifa_addr;
 121                 if (sin->sin_family != AF_INET)
 122                         continue;
 123                 memcpy(addr, sin, addrlen);
 124                 rc = 0;
 125         }
 126
 127         freeifaddrs(ifr);
 128
 129         return rc;
 130 }
 131
 132 void
 133 libwebsocket_close_and_free_session(struct libwebsocket_context *this,
 134                                                        struct libwebsocket *wsi)
 135 {
 136         int n;
 137         int old_state;
 138         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
 139                                                   LWS_SEND_BUFFER_POST_PADDING];
 140
 141         if (!wsi)
 142                 return;
 143
 144         old_state = wsi->state;
 145
 146         if (old_state == WSI_STATE_DEAD_SOCKET)
 147                 return;
 148
 149         /* remove this fd from wsi mapping hashtable */
 150
 151         delete_from_fd(this, wsi->sock);
 152
 153         /* delete it from the internal poll list if still present */
 154
 155         for (n = 0; n < this->fds_count; n++) {
 156                 if (this->fds[n].fd != wsi->sock)
 157                         continue;
 158                 while (n < this->fds_count - 1) {
 159                         this->fds[n] = this->fds[n + 1];
 160                         n++;
 161                 }
 162                 this->fds_count--;
 163                 /* we only have to deal with one */
 164                 n = this->fds_count;
 165         }
 166
 167         /* remove also from external POLL support via protocol 0 */
 168
 169         this->protocols[0].callback(this, wsi,
 170                     LWS_CALLBACK_DEL_POLL_FD, (void *)(long)wsi->sock, NULL, 0);
 171
 172         /*
 173          * signal we are closing, libsocket_write will
 174          * add any necessary version-specific stuff.  If the write fails,
 175          * no worries we are closing anyway.  If we didn't initiate this
 176          * close, then our state has been changed to
 177          * WSI_STATE_RETURNED_CLOSE_ALREADY and we will skip this
 178          */
 179
 180         if (old_state == WSI_STATE_ESTABLISHED)
 181                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
 182                                                                LWS_WRITE_CLOSE);
 183
 184         wsi->state = WSI_STATE_DEAD_SOCKET;
 185
 186         /* tell the user it's all over for this guy */
 187
 188         if (wsi->protocol->callback && old_state == WSI_STATE_ESTABLISHED)
 189                 wsi->protocol->callback(this, wsi, LWS_CALLBACK_CLOSED,
 190                                                       wsi->user_space, NULL, 0);
 191
 192         /* free up his allocations */
 193
 194         for (n = 0; n < WSI_TOKEN_COUNT; n++)
 195                 if (wsi->utf8_token[n].token)
 196                         free(wsi->utf8_token[n].token);
 197
 198 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
 199
 200 #ifdef LWS_OPENSSL_SUPPORT
 201         if (wsi->ssl) {
 202                 n = SSL_get_fd(wsi->ssl);
 203                 SSL_shutdown(wsi->ssl);
 204                 close(n);
 205                 SSL_free(wsi->ssl);
 206         } else {
 207 #endif
 208                 shutdown(wsi->sock, SHUT_RDWR);
 209                 close(wsi->sock);
 210 #ifdef LWS_OPENSSL_SUPPORT
 211         }
 212 #endif
 213         if (wsi->user_space)
 214                 free(wsi->user_space);
 215
 216         free(wsi);
 217 }
 218
 219 /**
 220  * libwebsockets_hangup_on_client() - Server calls to terminate client
 221  *                                      connection
 222  * @this:       libwebsockets context
 223  * @fd:         Connection socket descriptor
 224  */
 225
 226 void
 227 libwebsockets_hangup_on_client(struct libwebsocket_context *this, int fd)
 228 {
 229         struct libwebsocket *wsi = wsi_from_fd(this, fd);
 230         int n;
 231
 232         if (wsi == NULL)
 233                 return;
 234
 235         delete_from_fd(this, fd);
 236
 237         for (n = 0; n < this->fds_count - 1; n++)
 238                 if (this->fds[n].fd == fd) {
 239                         while (n < this->fds_count - 1) {
 240                                 this->fds[n] = this->fds[n + 1];
 241                                 n++;
 242                         }
 243                         n = this->fds_count;
 244                         this->fds_count--;
 245                 }
 246
 247         libwebsocket_close_and_free_session(this, wsi);
 248 }
 249
 250
 251 /**
 252  * libwebsockets_get_peer_addresses() - Get client address information
 253  * @fd:         Connection socket descriptor
 254  * @name:       Buffer to take client address name
 255  * @name_len:   Length of client address name buffer
 256  * @rip:        Buffer to take client address IP qotted quad
 257  * @rip_len:    Length of client address IP buffer
 258  *
 259  *      This function fills in @name and @rip with the name and IP of
 260  *      the client connected with socket descriptor @fd.  Names may be
 261  *      truncated if there is not enough room.  If either cannot be
 262  *      determined, they will be returned as valid zero-length strings.
 263  */
 264
 265 void
 266 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
 267                                         char *rip, int rip_len)
 268 {
 269         unsigned int len;
 270         struct sockaddr_in sin;
 271         struct hostent *host;
 272         struct hostent *host1;
 273         char ip[128];
 274         char *p;
 275         int n;
 276
 277         rip[0] = '\0';
 278         name[0] = '\0';
 279
 280         len = sizeof sin;
 281         if (getpeername(fd, (struct sockaddr *) &sin, &len) < 0) {
 282                 perror("getpeername");
 283                 return;
 284         }
 285
 286         host = gethostbyaddr((char *) &sin.sin_addr, sizeof sin.sin_addr,
 287                                                                        AF_INET);
 288         if (host == NULL) {
 289                 perror("gethostbyaddr");
 290                 return;
 291         }
 292
 293         strncpy(name, host->h_name, name_len);
 294         name[name_len - 1] = '\0';
 295
 296         host1 = gethostbyname(host->h_name);
 297         if (host1 == NULL)
 298                 return;
 299         p = (char *)host1;
 300         n = 0;
 301         while (p != NULL) {
 302                 p = host1->h_addr_list[n++];
 303                 if (p == NULL)
 304                         continue;
 305                 if (host1->h_addrtype != AF_INET)
 306                         continue;
 307
 308                 sprintf(ip, "%d.%d.%d.%d",
 309                                 p[0], p[1], p[2], p[3]);
 310                 p = NULL;
 311                 strncpy(rip, ip, rip_len);
 312                 rip[rip_len - 1] = '\0';
 313         }
 314 }
 315
 316 /**
 317  * libwebsocket_service_fd() - Service polled socket with something waiting
 318  * @this:       Websocket context
 319  * @pollfd:     The pollfd entry describing the socket fd and which events
 320  *              happened.
 321  *
 322  *      This function closes any active connections and then frees the
 323  *      context.  After calling this, any further use of the context is
 324  *      undefined.
 325  */
 326
 327 int
 328 libwebsocket_service_fd(struct libwebsocket_context *this,
 329                                                           struct pollfd *pollfd)
 330 {
 331         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
 332                                                   LWS_SEND_BUFFER_POST_PADDING];
 333         struct libwebsocket *wsi;
 334         struct libwebsocket *new_wsi;
 335         int n;
 336         int m;
 337         size_t len;
 338         int accept_fd;
 339         unsigned int clilen;
 340         struct sockaddr_in cli_addr;
 341         struct timeval tv;
 342         static const char magic_websocket_guid[] =
 343                                          "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 344         static const char magic_websocket_04_masking_guid[] =
 345                                          "61AC5F19-FBBA-4540-B96F-6561F1AB40A8";
 346         char hash[20];
 347         char pkt[1024];
 348         char *p = &pkt[0];
 349         const char *pc;
 350         int okay = 0;
 351 #ifdef LWS_OPENSSL_SUPPORT
 352         char ssl_err_buf[512];
 353 #endif
 354         /*
 355          * you can call us with pollfd = NULL to just allow the once-per-second
 356          * global timeout checks; if less than a second since the last check
 357          * it returns immediately then.
 358          */
 359
 360         gettimeofday(&tv, NULL);
 361
 362         if (this->last_timeout_check_s != tv.tv_sec) {
 363                 this->last_timeout_check_s = tv.tv_sec;
 364
 365                 /* global timeout check once per second */
 366
 367                 for (n = 0; n < this->fds_count; n++) {
 368                         wsi = wsi_from_fd(this, this->fds[n].fd);
 369                         if (!wsi->pending_timeout)
 370                                 continue;
 371
 372                         /*
 373                          * if we went beyond the allowed time, kill the
 374                          * connection
 375                          */
 376
 377                         if (tv.tv_sec > wsi->pending_timeout_limit)
 378                                 libwebsocket_close_and_free_session(this, wsi);
 379                 }
 380         }
 381
 382         /* just here for timeout management? */
 383
 384         if (pollfd == NULL)
 385                 return 0;
 386
 387         /* no, here to service a socket descriptor */
 388
 389         wsi = wsi_from_fd(this, pollfd->fd);
 390
 391         if (wsi == NULL)
 392                 return 1;
 393
 394         switch (wsi->mode) {
 395         case LWS_CONNMODE_SERVER_LISTENER:
 396
 397                 /* pollin means a client has connected to us then */
 398
 399                 if (!pollfd->revents & POLLIN)
 400                         break;
 401
 402                 /* listen socket got an unencrypted connection... */
 403
 404                 clilen = sizeof(cli_addr);
 405                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 406                                                                        &clilen);
 407                 if (accept_fd < 0) {
 408                         fprintf(stderr, "ERROR on accept");
 409                         break;
 410                 }
 411
 412                 if (this->fds_count >= MAX_CLIENTS) {
 413                         fprintf(stderr, "too busy to accept new client\n");
 414                         close(accept_fd);
 415                         break;
 416                 }
 417
 418                 /*
 419                  * look at who we connected to and give user code a chance
 420                  * to reject based on client IP.  There's no protocol selected
 421                  * yet so we issue this to protocols[0]
 422                  */
 423
 424                 if ((this->protocols[0].callback)(this, wsi,
 425                                 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
 426                                              (void*)(long)accept_fd, NULL, 0)) {
 427                         fprintf(stderr, "Callback denied network connection\n");
 428                         close(accept_fd);
 429                         break;
 430                 }
 431
 432                 /* accepting connection to main listener */
 433
 434                 new_wsi = malloc(sizeof(struct libwebsocket));
 435                 if (new_wsi == NULL) {
 436                         fprintf(stderr, "Out of memory for new connection\n");
 437                         break;
 438                 }
 439
 440                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 441                 new_wsi->sock = accept_fd;
 442                 new_wsi->pending_timeout = NO_PENDING_TIMEOUT;
 443
 444 #ifdef LWS_OPENSSL_SUPPORT
 445                 new_wsi->ssl = NULL;
 446
 447                 if (this->use_ssl) {
 448
 449                         new_wsi->ssl = SSL_new(this->ssl_ctx);
 450                         if (new_wsi->ssl == NULL) {
 451                                 fprintf(stderr, "SSL_new failed: %s\n",
 452                                     ERR_error_string(SSL_get_error(
 453                                     new_wsi->ssl, 0), NULL));
 454                                     libwebsockets_decode_ssl_error();
 455                                 free(new_wsi);
 456                                 break;
 457                         }
 458
 459                         SSL_set_fd(new_wsi->ssl, accept_fd);
 460
 461                         n = SSL_accept(new_wsi->ssl);
 462                         if (n != 1) {
 463                                 /*
 464                                  * browsers seem to probe with various
 465                                  * ssl params which fail then retry
 466                                  * and succeed
 467                                  */
 468                                 debug("SSL_accept failed skt %u: %s\n",
 469                                       pollfd->fd,
 470                                       ERR_error_string(SSL_get_error(
 471                                       new_wsi->ssl, n), NULL));
 472                                 SSL_free(
 473                                        new_wsi->ssl);
 474                                 free(new_wsi);
 475                                 break;
 476                         }
 477
 478                         debug("accepted new SSL conn  "
 479                               "port %u on fd=%d SSL ver %s\n",
 480                                 ntohs(cli_addr.sin_port), accept_fd,
 481                                   SSL_get_version(new_wsi->ssl));
 482
 483                 } else
 484 #endif
 485                         debug("accepted new conn  port %u on fd=%d\n",
 486                                           ntohs(cli_addr.sin_port), accept_fd);
 487
 488                 /* intialize the instance struct */
 489
 490                 new_wsi->state = WSI_STATE_HTTP;
 491                 new_wsi->name_buffer_pos = 0;
 492                 new_wsi->mode = LWS_CONNMODE_WS_SERVING;
 493
 494                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 495                         new_wsi->utf8_token[n].token = NULL;
 496                         new_wsi->utf8_token[n].token_len = 0;
 497                 }
 498
 499                 /*
 500                  * these can only be set once the protocol is known
 501                  * we set an unestablished connection's protocol pointer
 502                  * to the start of the supported list, so it can look
 503                  * for matching ones during the handshake
 504                  */
 505                 new_wsi->protocol = this->protocols;
 506                 new_wsi->user_space = NULL;
 507
 508                 /*
 509                  * Default protocol is 76 / 00
 510                  * After 76, there's a header specified to inform which
 511                  * draft the client wants, when that's seen we modify
 512                  * the individual connection's spec revision accordingly
 513                  */
 514                 new_wsi->ietf_spec_revision = 0;
 515
 516                 insert_wsi(this, new_wsi);
 517
 518                 /*
 519                  * make sure NO events are seen yet on this new socket
 520                  * (otherwise we inherit old fds[client].revents from
 521                  * previous socket there and die mysteriously! )
 522                  */
 523                 this->fds[this->fds_count].revents = 0;
 524
 525                 this->fds[this->fds_count].events = POLLIN;
 526                 this->fds[this->fds_count++].fd = accept_fd;
 527
 528                 /* external POLL support via protocol 0 */
 529                 this->protocols[0].callback(this, new_wsi,
 530                         LWS_CALLBACK_ADD_POLL_FD,
 531                         (void *)(long)accept_fd, NULL, POLLIN);
 532
 533                 break;
 534
 535         case LWS_CONNMODE_BROADCAST_PROXY_LISTENER:
 536
 537                 /* as we are listening, POLLIN means accept() is needed */
 538
 539                 if (!pollfd->revents & POLLIN)
 540                         break;
 541
 542                 /* listen socket got an unencrypted connection... */
 543
 544                 clilen = sizeof(cli_addr);
 545                 accept_fd  = accept(pollfd->fd, (struct sockaddr *)&cli_addr,
 546                                                                        &clilen);
 547                 if (accept_fd < 0) {
 548                         fprintf(stderr, "ERROR on accept");
 549                         break;
 550                 }
 551
 552                 if (this->fds_count >= MAX_CLIENTS) {
 553                         fprintf(stderr, "too busy to accept new broadcast "
 554                                                               "proxy client\n");
 555                         close(accept_fd);
 556                         break;
 557                 }
 558
 559                 /* create a dummy wsi for the connection and add it */
 560
 561                 new_wsi = malloc(sizeof(struct libwebsocket));
 562                 memset(new_wsi, 0, sizeof (struct libwebsocket));
 563                 new_wsi->sock = accept_fd;
 564                 new_wsi->mode = LWS_CONNMODE_BROADCAST_PROXY;
 565                 new_wsi->state = WSI_STATE_ESTABLISHED;
 566                 /* note which protocol we are proxying */
 567                 new_wsi->protocol_index_for_broadcast_proxy =
 568                                         wsi->protocol_index_for_broadcast_proxy;
 569                 insert_wsi(this, new_wsi);
 570
 571                 /* add connected socket to internal poll array */
 572
 573                 this->fds[this->fds_count].revents = 0;
 574                 this->fds[this->fds_count].events = POLLIN;
 575                 this->fds[this->fds_count++].fd = accept_fd;
 576
 577                 /* external POLL support via protocol 0 */
 578                 this->protocols[0].callback(this, new_wsi,
 579                         LWS_CALLBACK_ADD_POLL_FD,
 580                         (void *)(long)accept_fd, NULL, POLLIN);
 581
 582                 break;
 583
 584         case LWS_CONNMODE_BROADCAST_PROXY:
 585
 586                 /* handle session socket closed */
 587
 588                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 589
 590                         debug("Session Socket %p (fd=%d) dead\n",
 591                                 (void *)wsi, pollfd->fd);
 592
 593                         libwebsocket_close_and_free_session(this, wsi);
 594                         return 1;
 595                 }
 596
 597                 /* the guy requested a callback when it was OK to write */
 598
 599                 if (pollfd->revents & POLLOUT) {
 600
 601                         /* one shot */
 602
 603                         pollfd->events &= ~POLLOUT;
 604
 605                         /* external POLL support via protocol 0 */
 606                         this->protocols[0].callback(this, wsi,
 607                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 608                                 (void *)(long)wsi->sock, NULL, POLLOUT);
 609
 610                         wsi->protocol->callback(this, wsi,
 611                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 612                                 wsi->user_space,
 613                                 NULL, 0);
 614                 }
 615
 616                 /* any incoming data ready? */
 617
 618                 if (!(pollfd->revents & POLLIN))
 619                         break;
 620
 621                 /* get the issued broadcast payload from the socket */
 622
 623                 len = read(pollfd->fd, buf + LWS_SEND_BUFFER_PRE_PADDING,
 624                                                          MAX_BROADCAST_PAYLOAD);
 625                 if (len < 0) {
 626                         fprintf(stderr, "Error reading broadcast payload\n");
 627                         break;
 628                 }
 629
 630                 /* broadcast it to all guys with this protocol index */
 631
 632                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
 633
 634                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
 635
 636                                 new_wsi = this->fd_hashtable[n].wsi[m];
 637
 638                                 /* only to clients we are serving to */
 639
 640                                 if (new_wsi->mode != LWS_CONNMODE_WS_SERVING)
 641                                         continue;
 642
 643                                 /*
 644                                  * never broadcast to non-established
 645                                  * connection
 646                                  */
 647
 648                                 if (new_wsi->state != WSI_STATE_ESTABLISHED)
 649                                         continue;
 650
 651                                 /*
 652                                  * only broadcast to connections using
 653                                  * the requested protocol
 654                                  */
 655
 656                                 if (new_wsi->protocol->protocol_index !=
 657                                         wsi->protocol_index_for_broadcast_proxy)
 658                                         continue;
 659
 660                                 /* broadcast it to this connection */
 661
 662                                 new_wsi->protocol->callback(this, new_wsi,
 663                                         LWS_CALLBACK_BROADCAST,
 664                                         new_wsi->user_space,
 665                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 666                         }
 667                 }
 668                 break;
 669
 670         case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
 671
 672                 /* handle proxy hung up on us */
 673
 674                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 675
 676                         fprintf(stderr, "Proxy connection %p (fd=%d) dead\n",
 677                                 (void *)wsi, pollfd->fd);
 678
 679                         libwebsocket_close_and_free_session(this, wsi);
 680                         return 1;
 681                 }
 682
 683                 n = recv(wsi->sock, pkt, sizeof pkt, 0);
 684                 if (n < 0) {
 685                         libwebsocket_close_and_free_session(this, wsi);
 686                         fprintf(stderr, "ERROR reading from proxy socket\n");
 687                         return 1;
 688                 }
 689
 690                 pkt[13] = '\0';
 691                 if (strcmp(pkt, "HTTP/1.0 200 ") != 0) {
 692                         libwebsocket_close_and_free_session(this, wsi);
 693                         fprintf(stderr, "ERROR from proxy: %s\n", pkt);
 694                         return 1;
 695                 }
 696
 697                 /* clear his proxy connection timeout */
 698
 699                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 700
 701                 /* fallthru */
 702
 703         case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
 704
 705         #ifdef LWS_OPENSSL_SUPPORT
 706                 if (wsi->use_ssl) {
 707
 708                         wsi->ssl = SSL_new(this->ssl_client_ctx);
 709                         wsi->client_bio = BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 710                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 711
 712                         if (SSL_connect(wsi->ssl) <= 0) {
 713                                 fprintf(stderr, "SSL connect error %s\n",
 714                                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 715                                 libwebsocket_close_and_free_session(this, wsi);
 716                                 return 1;
 717                         }
 718
 719                         n = SSL_get_verify_result(wsi->ssl);
 720                         if (n != X509_V_OK) {
 721                                 if (n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 722                                                             wsi->use_ssl != 2) {
 723
 724                                         fprintf(stderr, "server's cert didn't "
 725                                                                    "look good %d\n", n);
 726                                         libwebsocket_close_and_free_session(this, wsi);
 727                                         return 1;
 728                                 }
 729                         }
 730                 } else {
 731                         wsi->ssl = NULL;
 732         #endif
 733
 734
 735         #ifdef LWS_OPENSSL_SUPPORT
 736                 }
 737         #endif
 738
 739                 /*
 740                  * create the random key
 741                  */
 742
 743                 n = read(this->fd_random, hash, 16);
 744                 if (n != 16) {
 745                         fprintf(stderr, "Unable to read from random dev %s\n",
 746                                                         SYSTEM_RANDOM_FILEPATH);
 747                         free(wsi->c_path);
 748                         free(wsi->c_host);
 749                         free(wsi->c_origin);
 750                         if (wsi->c_protocol)
 751                                 free(wsi->c_protocol);
 752                         libwebsocket_close_and_free_session(this, wsi);
 753                         return 1;
 754                 }
 755
 756                 lws_b64_encode_string(hash, 16, wsi->key_b64,
 757                                                            sizeof wsi->key_b64);
 758
 759                 /*
 760                  * 04 example client handshake
 761                  *
 762                  * GET /chat HTTP/1.1
 763                  * Host: server.example.com
 764                  * Upgrade: websocket
 765                  * Connection: Upgrade
 766                  * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 767                  * Sec-WebSocket-Origin: http://example.com
 768                  * Sec-WebSocket-Protocol: chat, superchat
 769                  * Sec-WebSocket-Version: 4
 770                  */
 771
 772                  p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", wsi->c_path);
 773                  p += sprintf(p, "Host: %s\x0d\x0a", wsi->c_host);
 774                  p += sprintf(p, "Upgrade: websocket\x0d\x0a");
 775                  p += sprintf(p, "Connection: Upgrade\x0d\x0a"
 776                                         "Sec-WebSocket-Key: ");
 777                  strcpy(p, wsi->key_b64);
 778                  p += strlen(wsi->key_b64);
 779                  p += sprintf(p, "\x0d\x0aSec-WebSocket-Origin: %s\x0d\x0a",
 780                                                                  wsi->c_origin);
 781                  if (wsi->c_protocol != NULL)
 782                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 783                                                                wsi->c_protocol);
 784                  p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a",
 785                                                        wsi->ietf_spec_revision);
 786
 787                 /* done with these now */
 788
 789                 free(wsi->c_path);
 790                 free(wsi->c_host);
 791                 free(wsi->c_origin);
 792
 793                 /* prepare the expected server accept response */
 794
 795                 strcpy((char *)buf, wsi->key_b64);
 796                 strcpy((char *)&buf[strlen((char *)buf)], magic_websocket_guid);
 797
 798                 SHA1(buf, strlen((char *)buf), (unsigned char *)hash);
 799
 800                 lws_b64_encode_string(hash, 20,
 801                                 wsi->initial_handshake_hash_base64,
 802                                      sizeof wsi->initial_handshake_hash_base64);
 803
 804                 /* send our request to the server */
 805
 806         #ifdef LWS_OPENSSL_SUPPORT
 807                 if (wsi->use_ssl)
 808                         n = SSL_write(wsi->ssl, pkt, p - pkt);
 809                 else
 810         #endif
 811                         n = send(wsi->sock, pkt, p - pkt, 0);
 812
 813                 if (n < 0) {
 814                         fprintf(stderr, "ERROR writing to client socket\n");
 815                         libwebsocket_close_and_free_session(this, wsi);
 816                         return 1;
 817                 }
 818
 819                 wsi->parser_state = WSI_TOKEN_NAME_PART;
 820                 wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY;
 821                 libwebsocket_set_timeout(wsi,
 822                                 PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE, 5);
 823
 824                 break;
 825
 826         case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
 827
 828                 /* handle server hung up on us */
 829
 830                 if (pollfd->revents & (POLLERR | POLLHUP)) {
 831
 832                         fprintf(stderr, "Server connection %p (fd=%d) dead\n",
 833                                 (void *)wsi, pollfd->fd);
 834
 835                         goto bail3;
 836                 }
 837
 838
 839                 /* interpret the server response */
 840
 841                 /*
 842                  *  HTTP/1.1 101 Switching Protocols
 843                  *  Upgrade: websocket
 844                  *  Connection: Upgrade
 845                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 846                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 847                  *  Sec-WebSocket-Protocol: chat
 848                  */
 849
 850         #ifdef LWS_OPENSSL_SUPPORT
 851                 if (wsi->use_ssl)
 852                         len = SSL_read(wsi->ssl, pkt, sizeof pkt);
 853                 else
 854         #endif
 855                         len = recv(wsi->sock, pkt, sizeof pkt, 0);
 856
 857                 if (len < 0) {
 858                         fprintf(stderr,
 859                                   "libwebsocket_client_handshake read error\n");
 860                         goto bail3;
 861                 }
 862
 863                 p = pkt;
 864                 for (n = 0; n < len; n++)
 865                         libwebsocket_parse(wsi, *p++);
 866
 867                 if (wsi->parser_state != WSI_PARSING_COMPLETE) {
 868                         fprintf(stderr, "libwebsocket_client_handshake "
 869                                         "server response ailed parsing\n");
 870                         goto bail3;
 871                 }
 872
 873                 /*
 874                  * well, what the server sent looked reasonable for syntax.
 875                  * Now let's confirm it sent all the necessary headers
 876                  */
 877
 878                  if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len ||
 879                         !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
 880                         !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len ||
 881                         !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len ||
 882                         !wsi->utf8_token[WSI_TOKEN_NONCE].token_len ||
 883                         (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len &&
 884                                                      wsi->c_protocol != NULL)) {
 885                         fprintf(stderr, "libwebsocket_client_handshake "
 886                                                         "missing required header(s)\n");
 887                         pkt[len] = '\0';
 888                         fprintf(stderr, "%s", pkt);
 889                         goto bail3;
 890                 }
 891
 892                 /*
 893                  * Everything seems to be there, now take a closer look at what
 894                  * is in each header
 895                  */
 896
 897                 strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token);
 898                 if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token,
 899                                                    "101 switching protocols")) {
 900                         fprintf(stderr, "libwebsocket_client_handshake "
 901                                         "server sent bad HTTP response '%s'\n",
 902                                          wsi->utf8_token[WSI_TOKEN_HTTP].token);
 903                         goto bail3;
 904                 }
 905
 906                 strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 907                 if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token,
 908                                                                  "websocket")) {
 909                         fprintf(stderr, "libwebsocket_client_handshake server "
 910                                         "sent bad Upgrade header '%s'\n",
 911                                       wsi->utf8_token[WSI_TOKEN_UPGRADE].token);
 912                         goto bail3;
 913                 }
 914
 915                 strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 916                 if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token,
 917                                                                    "upgrade")) {
 918                         fprintf(stderr, "libwebsocket_client_handshake server "
 919                                         "sent bad Connection hdr '%s'\n",
 920                                    wsi->utf8_token[WSI_TOKEN_CONNECTION].token);
 921                         goto bail3;
 922                 }
 923
 924
 925                 pc = wsi->c_protocol;
 926
 927                 /*
 928                  * confirm the protocol the server wants to talk was in the list
 929                  * of protocols we offered
 930                  */
 931
 932                 if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) {
 933
 934                         /*
 935                          * no protocol name to work from,
 936                          * default to first protocol
 937                          */
 938                         wsi->protocol = &this->protocols[0];
 939
 940                         free(wsi->c_protocol);
 941
 942                         goto check_accept;
 943                 }
 944
 945                 while (*pc && !okay) {
 946                         if ((!strncmp(pc,
 947                                 wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 948                            wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) &&
 949                  (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' ||
 950                    pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) {
 951                                 okay = 1;
 952                                 continue;
 953                         }
 954                         while (*pc && *pc != ',')
 955                                 pc++;
 956                         while (*pc && *pc != ' ')
 957                                 pc++;
 958                 }
 959
 960                 /* done with him now */
 961
 962                 if (wsi->c_protocol)
 963                         free(wsi->c_protocol);
 964
 965
 966                 if (!okay) {
 967                         fprintf(stderr, "libwebsocket_client_handshake server "
 968                                                 "sent bad protocol '%s'\n",
 969                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 970                         goto bail2;
 971                 }
 972
 973                 /*
 974                  * identify the selected protocol struct and set it
 975                  */
 976                 n = 0;
 977                 wsi->protocol = NULL;
 978                 while (this->protocols[n].callback) {
 979                         if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
 980                                                this->protocols[n].name) == 0)
 981                                 wsi->protocol = &this->protocols[n];
 982                         n++;
 983                 }
 984
 985                 if (wsi->protocol == NULL) {
 986                         fprintf(stderr, "libwebsocket_client_handshake server "
 987                                         "requested protocol '%s', which we "
 988                                         "said we supported but we don't!\n",
 989                                      wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
 990                         goto bail2;
 991                 }
 992
 993         check_accept:
 994                 /*
 995                  * Confirm his accept token is the one we precomputed
 996                  */
 997
 998                 if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
 999                                           wsi->initial_handshake_hash_base64)) {
1000                         fprintf(stderr, "libwebsocket_client_handshake server "
1001                                 "sent bad ACCEPT '%s' vs computed '%s'\n",
1002                                 wsi->utf8_token[WSI_TOKEN_ACCEPT].token,
1003                                             wsi->initial_handshake_hash_base64);
1004                         goto bail2;
1005                 }
1006
1007                 /*
1008                  * Calculate the masking key to use when sending data to server
1009                  */
1010
1011                 strcpy((char *)buf, wsi->key_b64);
1012                 p = (char *)buf + strlen(wsi->key_b64);
1013                 strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token);
1014                 p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len;
1015                 strcpy(p, magic_websocket_04_masking_guid);
1016                 SHA1(buf, strlen((char *)buf), wsi->masking_key_04);
1017
1018                 /* allocate the per-connection user memory (if any) */
1019
1020                 if (wsi->protocol->per_session_data_size) {
1021                         wsi->user_space = malloc(
1022                                           wsi->protocol->per_session_data_size);
1023                         if (wsi->user_space  == NULL) {
1024                                 fprintf(stderr, "Out of memory for "
1025                                                            "conn user space\n");
1026                                 goto bail2;
1027                         }
1028                 } else
1029                         wsi->user_space = NULL;
1030
1031                 /* clear his proxy connection timeout */
1032
1033                 libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1034
1035                 /* mark him as being alive */
1036
1037                 wsi->state = WSI_STATE_ESTABLISHED;
1038                 wsi->mode = LWS_CONNMODE_WS_CLIENT;
1039
1040                 fprintf(stderr, "handshake OK for protocol %s\n",
1041                                                            wsi->protocol->name);
1042
1043                 /* call him back to inform him he is up */
1044
1045                 wsi->protocol->callback(this, wsi,
1046                                  LWS_CALLBACK_CLIENT_ESTABLISHED,
1047                                  wsi->user_space,
1048                                  NULL, 0);
1049
1050                 break;
1051
1052 bail3:
1053                 if (wsi->c_protocol)
1054                         free(wsi->c_protocol);
1055
1056 bail2:
1057                 libwebsocket_close_and_free_session(this, wsi);
1058                 return 1;
1059
1060
1061         case LWS_CONNMODE_WS_SERVING:
1062         case LWS_CONNMODE_WS_CLIENT:
1063
1064                 /* handle session socket closed */
1065
1066                 if (pollfd->revents & (POLLERR | POLLHUP)) {
1067
1068                         fprintf(stderr, "Session Socket %p (fd=%d) dead\n",
1069                                 (void *)wsi, pollfd->fd);
1070
1071                         libwebsocket_close_and_free_session(this, wsi);
1072                         return 1;
1073                 }
1074
1075                 /* the guy requested a callback when it was OK to write */
1076
1077                 if (pollfd->revents & POLLOUT) {
1078
1079                         pollfd->events &= ~POLLOUT;
1080
1081                         /* external POLL support via protocol 0 */
1082                         this->protocols[0].callback(this, wsi,
1083                                 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1084                                 (void *)(long)wsi->sock, NULL, POLLOUT);
1085
1086                         wsi->protocol->callback(this, wsi,
1087                                 LWS_CALLBACK_CLIENT_WRITEABLE,
1088                                 wsi->user_space,
1089                                 NULL, 0);
1090                 }
1091
1092                 /* any incoming data ready? */
1093
1094                 if (!(pollfd->revents & POLLIN))
1095                         break;
1096
1097 #ifdef LWS_OPENSSL_SUPPORT
1098                 if (wsi->ssl)
1099                         n = SSL_read(wsi->ssl, buf, sizeof buf);
1100                 else
1101 #endif
1102                         n = recv(pollfd->fd, buf, sizeof buf, 0);
1103
1104                 if (n < 0) {
1105                         fprintf(stderr, "Socket read returned %d\n", n);
1106                         break;
1107                 }
1108                 if (!n) {
1109                         libwebsocket_close_and_free_session(this, wsi);
1110                         return 1;
1111                 }
1112
1113                 /* service incoming data */
1114
1115                 n = libwebsocket_read(this, wsi, buf, n);
1116                 if (n >= 0)
1117                         break;
1118
1119                 /* we closed wsi */
1120
1121                 return 1;
1122         }
1123
1124         return 0;
1125 }
1126
1127
1128 /**
1129  * libwebsocket_context_destroy() - Destroy the websocket context
1130  * @this:       Websocket context
1131  *
1132  *      This function closes any active connections and then frees the
1133  *      context.  After calling this, any further use of the context is
1134  *      undefined.
1135  */
1136 void
1137 libwebsocket_context_destroy(struct libwebsocket_context *this)
1138 {
1139         int n;
1140         int m;
1141         struct libwebsocket *wsi;
1142
1143         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1144                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1145                         wsi = this->fd_hashtable[n].wsi[m];
1146                         libwebsocket_close_and_free_session(this, wsi);
1147                 }
1148
1149         close(this->fd_random);
1150
1151 #ifdef LWS_OPENSSL_SUPPORT
1152         if (this->ssl_ctx)
1153                 SSL_CTX_free(this->ssl_ctx);
1154         if (this->ssl_client_ctx)
1155                 SSL_CTX_free(this->ssl_client_ctx);
1156 #endif
1157
1158         free(this);
1159 }
1160
1161 /**
1162  * libwebsocket_service() - Service any pending websocket activity
1163  * @this:       Websocket context
1164  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
1165  *              service otherwise block and service immediately, returning
1166  *              after the timeout if nothing needed service.
1167  *
1168  *      This function deals with any pending websocket traffic, for three
1169  *      kinds of event.  It handles these events on both server and client
1170  *      types of connection the same.
1171  *
1172  *      1) Accept new connections to our context's server
1173  *
1174  *      2) Perform pending broadcast writes initiated from other forked
1175  *         processes (effectively serializing asynchronous broadcasts)
1176  *
1177  *      3) Call the receive callback for incoming frame data received by
1178  *          server or client connections.
1179  *
1180  *      You need to call this service function periodically to all the above
1181  *      functions to happen; if your application is single-threaded you can
1182  *      just call it in your main event loop.
1183  *
1184  *      Alternatively you can fork a new process that asynchronously handles
1185  *      calling this service in a loop.  In that case you are happy if this
1186  *      call blocks your thread until it needs to take care of something and
1187  *      would call it with a large nonzero timeout.  Your loop then takes no
1188  *      CPU while there is nothing happening.
1189  *
1190  *      If you are calling it in a single-threaded app, you don't want it to
1191  *      wait around blocking other things in your loop from happening, so you
1192  *      would call it with a timeout_ms of 0, so it returns immediately if
1193  *      nothing is pending, or as soon as it services whatever was pending.
1194  */
1195
1196
1197 int
1198 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
1199 {
1200         int n;
1201
1202         /* stay dead once we are dead */
1203
1204         if (this == NULL)
1205                 return 1;
1206
1207         /* wait for something to need service */
1208
1209         n = poll(this->fds, this->fds_count, timeout_ms);
1210         if (n == 0) /* poll timeout */
1211                 return 0;
1212
1213         if (n < 0) {
1214                 /*
1215                 fprintf(stderr, "Listen Socket dead\n");
1216                 */
1217                 return 1;
1218         }
1219
1220         /* handle accept on listening socket? */
1221
1222         for (n = 0; n < this->fds_count; n++)
1223                 if (this->fds[n].revents)
1224                         libwebsocket_service_fd(this, &this->fds[n]);
1225
1226         return 0;
1227 }
1228
1229 /**
1230  * libwebsocket_callback_on_writable() - Request a callback when this socket
1231  *                                       becomes able to be written to without
1232  *                                       blocking
1233  *
1234  * @this:       libwebsockets context
1235  * @wsi:        Websocket connection instance to get callback for
1236  */
1237
1238 int
1239 libwebsocket_callback_on_writable(struct libwebsocket_context *this,
1240                                                        struct libwebsocket *wsi)
1241 {
1242         int n;
1243
1244         for (n = 0; n < this->fds_count; n++)
1245                 if (this->fds[n].fd == wsi->sock) {
1246                         this->fds[n].events |= POLLOUT;
1247                         n = this->fds_count;
1248                 }
1249
1250         /* external POLL support via protocol 0 */
1251         this->protocols[0].callback(this, wsi,
1252                 LWS_CALLBACK_SET_MODE_POLL_FD,
1253                 (void *)(long)wsi->sock, NULL, POLLOUT);
1254
1255         return 1;
1256 }
1257
1258 /**
1259  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
1260  *                      all connections using the given protocol when it
1261  *                      becomes possible to write to each socket without
1262  *                      blocking in turn.
1263  *
1264  * @protocol:   Protocol whose connections will get callbacks
1265  */
1266
1267 int
1268 libwebsocket_callback_on_writable_all_protocol(
1269                                   const struct libwebsocket_protocols *protocol)
1270 {
1271         struct libwebsocket_context *this = protocol->owning_server;
1272         int n;
1273         int m;
1274         struct libwebsocket *wsi;
1275
1276         for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1277
1278                 for (m = 0; m < this->fd_hashtable[n].length; m++) {
1279
1280                         wsi = this->fd_hashtable[n].wsi[m];
1281
1282                         if (wsi->protocol == protocol)
1283                                 libwebsocket_callback_on_writable(this, wsi);
1284                 }
1285         }
1286
1287         return 0;
1288 }
1289
1290 /**
1291  * libwebsocket_set_timeout() - marks the wsi as subject to a timeout
1292  *
1293  * You will not need this unless you are doing something special
1294  *
1295  * @wsi:        Websocket connection instance
1296  * @reason:     timeout reason
1297  * @secs:       how many seconds
1298  */
1299
1300 void
1301 libwebsocket_set_timeout(struct libwebsocket *wsi,
1302                                           enum pending_timeout reason, int secs)
1303 {
1304         struct timeval tv;
1305
1306         gettimeofday(&tv, NULL);
1307
1308         wsi->pending_timeout_limit = tv.tv_sec + secs;
1309         wsi->pending_timeout = reason;
1310 }
1311
1312
1313 /**
1314  * libwebsocket_get_socket_fd() - returns the socket file descriptor
1315  *
1316  * You will not need this unless you are doing something special
1317  *
1318  * @wsi:        Websocket connection instance
1319  */
1320
1321 int
1322 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
1323 {
1324         return wsi->sock;
1325 }
1326
1327 /**
1328  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
1329  *                              receieved packets.
1330  *
1331  * If the output side of a server process becomes choked, this allows flow
1332  * control for the input side.
1333  *
1334  * @wsi:        Websocket connection instance to get callback for
1335  * @enable:     0 = disable read servicing for this connection, 1 = enable
1336  */
1337
1338 int
1339 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
1340 {
1341         struct libwebsocket_context *this = wsi->protocol->owning_server;
1342         int n;
1343
1344         for (n = 0; n < this->fds_count; n++)
1345                 if (this->fds[n].fd == wsi->sock) {
1346                         if (enable)
1347                                 this->fds[n].events |= POLLIN;
1348                         else
1349                                 this->fds[n].events &= ~POLLIN;
1350
1351                         return 0;
1352                 }
1353
1354         if (enable)
1355                 /* external POLL support via protocol 0 */
1356                 this->protocols[0].callback(this, wsi,
1357                         LWS_CALLBACK_SET_MODE_POLL_FD,
1358                         (void *)(long)wsi->sock, NULL, POLLIN);
1359         else
1360                 /* external POLL support via protocol 0 */
1361                 this->protocols[0].callback(this, wsi,
1362                         LWS_CALLBACK_CLEAR_MODE_POLL_FD,
1363                         (void *)(long)wsi->sock, NULL, POLLIN);
1364
1365
1366         fprintf(stderr, "libwebsocket_callback_on_writable "
1367                                                      "unable to find socket\n");
1368         return 1;
1369 }
1370
1371 /**
1372  * libwebsocket_canonical_hostname() - returns this host's hostname
1373  *
1374  * This is typically used by client code to fill in the host parameter
1375  * when making a client connection.  You can only call it after the context
1376  * has been created.
1377  *
1378  * @this:       Websocket context
1379  */
1380
1381
1382 extern const char *
1383 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
1384 {
1385         return (const char *)this->canonical_hostname;
1386 }
1387
1388
1389 static void sigpipe_handler(int x)
1390 {
1391 }
1392
1393
1394 /**
1395  * libwebsocket_create_context() - Create the websocket handler
1396  * @port:       Port to listen on... you can use 0 to suppress listening on
1397  *              any port, that's what you want if you are not running a
1398  *              websocket server at all but just using it as a client
1399  * @interface:  NULL to bind the listen socket to all interfaces, or the
1400  *              interface name, eg, "eth2"
1401  * @protocols:  Array of structures listing supported protocols and a protocol-
1402  *              specific callback for each one.  The list is ended with an
1403  *              entry that has a NULL callback pointer.
1404  *              It's not const because we write the owning_server member
1405  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
1406  *                      to listen using SSL, set to the filepath to fetch the
1407  *                      server cert from, otherwise NULL for unencrypted
1408  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
1409  *                      else ignored
1410  * @gid:        group id to change to after setting listen socket, or -1.
1411  * @uid:        user id to change to after setting listen socket, or -1.
1412  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
1413  *
1414  *      This function creates the listening socket and takes care
1415  *      of all initialization in one step.
1416  *
1417  *      After initialization, it returns a struct libwebsocket_context * that
1418  *      represents this server.  After calling, user code needs to take care
1419  *      of calling libwebsocket_service() with the context pointer to get the
1420  *      server's sockets serviced.  This can be done in the same process context
1421  *      or a forked process, or another thread,
1422  *
1423  *      The protocol callback functions are called for a handful of events
1424  *      including http requests coming in, websocket connections becoming
1425  *      established, and data arriving; it's also called periodically to allow
1426  *      async transmission.
1427  *
1428  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
1429  *      at that time websocket protocol has not been negotiated.  Other
1430  *      protocols after the first one never see any HTTP callack activity.
1431  *
1432  *      The server created is a simple http server by default; part of the
1433  *      websocket standard is upgrading this http connection to a websocket one.
1434  *
1435  *      This allows the same server to provide files like scripts and favicon /
1436  *      images or whatever over http and dynamic data over websockets all in
1437  *      one place; they're all handled in the user callback.
1438  */
1439
1440 struct libwebsocket_context *
1441 libwebsocket_create_context(int port, const char *interface,
1442                                struct libwebsocket_protocols *protocols,
1443                                const char *ssl_cert_filepath,
1444                                const char *ssl_private_key_filepath,
1445                                int gid, int uid, unsigned int options)
1446 {
1447         int n;
1448         int sockfd = 0;
1449         int fd;
1450         struct sockaddr_in serv_addr, cli_addr;
1451         int opt = 1;
1452         struct libwebsocket_context *this = NULL;
1453         unsigned int slen;
1454         char *p;
1455         char hostname[1024];
1456         struct hostent *he;
1457         struct libwebsocket *wsi;
1458
1459 #ifdef LWS_OPENSSL_SUPPORT
1460         SSL_METHOD *method;
1461         char ssl_err_buf[512];
1462 #endif
1463
1464         this = malloc(sizeof(struct libwebsocket_context));
1465         if (!this) {
1466                 fprintf(stderr, "No memory for websocket context\n");
1467                 return NULL;
1468         }
1469         this->protocols = protocols;
1470         this->listen_port = port;
1471         this->http_proxy_port = 0;
1472         this->http_proxy_address[0] = '\0';
1473         this->options = options;
1474         this->fds_count = 0;
1475
1476         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
1477         if (this->fd_random < 0) {
1478                 fprintf(stderr, "Unable to open random device %s %d\n",
1479                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
1480                 return NULL;
1481         }
1482
1483         /* find canonical hostname */
1484
1485         hostname[(sizeof hostname) - 1] = '\0';
1486         gethostname(hostname, (sizeof hostname) - 1);
1487         he = gethostbyname(hostname);
1488         if (he) {
1489                 strncpy(this->canonical_hostname, he->h_name,
1490                                            sizeof this->canonical_hostname - 1);
1491                 this->canonical_hostname[sizeof this->canonical_hostname - 1] =
1492                                                                            '\0';
1493         } else
1494                 strncpy(this->canonical_hostname, hostname,
1495                                            sizeof this->canonical_hostname - 1);
1496
1497         /* split the proxy ads:port if given */
1498
1499         p = getenv("http_proxy");
1500         if (p) {
1501                 strncpy(this->http_proxy_address, p,
1502                                            sizeof this->http_proxy_address - 1);
1503                 this->http_proxy_address[
1504                                     sizeof this->http_proxy_address - 1] = '\0';
1505
1506                 p = strchr(this->http_proxy_address, ':');
1507                 if (p == NULL) {
1508                         fprintf(stderr, "http_proxy needs to be ads:port\n");
1509                         return NULL;
1510                 }
1511                 *p = '\0';
1512                 this->http_proxy_port = atoi(p + 1);
1513
1514                 fprintf(stderr, "Using proxy %s:%u\n",
1515                                 this->http_proxy_address,
1516                                                         this->http_proxy_port);
1517         }
1518
1519         if (port) {
1520
1521 #ifdef LWS_OPENSSL_SUPPORT
1522                 this->use_ssl = ssl_cert_filepath != NULL &&
1523                                                ssl_private_key_filepath != NULL;
1524                 if (this->use_ssl)
1525                         fprintf(stderr, " Compiled with SSL support, "
1526                                                                   "using it\n");
1527                 else
1528                         fprintf(stderr, " Compiled with SSL support, "
1529                                                               "not using it\n");
1530
1531 #else
1532                 if (ssl_cert_filepath != NULL &&
1533                                              ssl_private_key_filepath != NULL) {
1534                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
1535                         return NULL;
1536                 }
1537                 fprintf(stderr, " Compiled without SSL support, "
1538                                                        "serving unencrypted\n");
1539 #endif
1540         }
1541
1542         /* ignore SIGPIPE */
1543
1544         signal(SIGPIPE, sigpipe_handler);
1545
1546
1547 #ifdef LWS_OPENSSL_SUPPORT
1548
1549         /* basic openssl init */
1550
1551         SSL_library_init();
1552
1553         OpenSSL_add_all_algorithms();
1554         SSL_load_error_strings();
1555
1556         /*
1557          * Firefox insists on SSLv23 not SSLv3
1558          * Konq disables SSLv2 by default now, SSLv23 works
1559          */
1560
1561         method = (SSL_METHOD *)SSLv23_server_method();
1562         if (!method) {
1563                 fprintf(stderr, "problem creating ssl method: %s\n",
1564                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1565                 return NULL;
1566         }
1567         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
1568         if (!this->ssl_ctx) {
1569                 fprintf(stderr, "problem creating ssl context: %s\n",
1570                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1571                 return NULL;
1572         }
1573
1574         /* client context */
1575
1576         method = (SSL_METHOD *)SSLv23_client_method();
1577         if (!method) {
1578                 fprintf(stderr, "problem creating ssl method: %s\n",
1579                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1580                 return NULL;
1581         }
1582         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
1583         if (!this->ssl_client_ctx) {
1584                 fprintf(stderr, "problem creating ssl context: %s\n",
1585                         ERR_error_string(ERR_get_error(), ssl_err_buf));
1586                 return NULL;
1587         }
1588
1589
1590         /* openssl init for cert verification (used with client sockets) */
1591
1592         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
1593                                                     LWS_OPENSSL_CLIENT_CERTS)) {
1594                 fprintf(stderr, "Unable to load SSL Client certs from %s "
1595                         "(set by --with-client-cert-dir= in configure) -- "
1596                         " client ssl isn't going to work",
1597                                                       LWS_OPENSSL_CLIENT_CERTS);
1598         }
1599
1600         /*
1601          * callback allowing user code to load extra verification certs
1602          * helping the client to verify server identity
1603          */
1604
1605         this->protocols[0].callback(this, NULL,
1606                 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
1607                 this->ssl_client_ctx, NULL, 0);
1608
1609         /* as a server, are we requiring clients to identify themselves? */
1610
1611         if (options & LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT) {
1612
1613                 /* absolutely require the client cert */
1614
1615                 SSL_CTX_set_verify(this->ssl_ctx,
1616                        SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);
1617
1618                 /*
1619                  * give user code a chance to load certs into the server
1620                  * allowing it to verify incoming client certs
1621                  */
1622
1623                 this->protocols[0].callback(this, NULL,
1624                         LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
1625                                                         this->ssl_ctx, NULL, 0);
1626         }
1627
1628
1629         if (this->use_ssl) {
1630
1631                 /* openssl init for server sockets */
1632
1633                 /* set the local certificate from CertFile */
1634                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
1635                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
1636                 if (n != 1) {
1637                         fprintf(stderr, "problem getting cert '%s': %s\n",
1638                                 ssl_cert_filepath,
1639                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1640                         return NULL;
1641                 }
1642                 /* set the private key from KeyFile */
1643                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
1644                                                 ssl_private_key_filepath,
1645                                                        SSL_FILETYPE_PEM) != 1) {
1646                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
1647                                                 ssl_private_key_filepath,
1648                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
1649                         return NULL;
1650                 }
1651                 /* verify private key */
1652                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
1653                         fprintf(stderr, "Private SSL key doesn't match cert\n");
1654                         return NULL;
1655                 }
1656
1657                 /* SSL is happy and has a cert it's content with */
1658         }
1659 #endif
1660
1661         /* selftest */
1662
1663         if (lws_b64_selftest())
1664                 return NULL;
1665
1666         /* fd hashtable init */
1667
1668         for (n = 0; n < FD_HASHTABLE_MODULUS; n++)
1669                 this->fd_hashtable[n].length = 0;
1670
1671         /* set up our external listening socket we serve on */
1672
1673         if (port) {
1674
1675                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
1676                 if (sockfd < 0) {
1677                         fprintf(stderr, "ERROR opening socket");
1678                         return NULL;
1679                 }
1680
1681                 /* allow us to restart even if old sockets in TIME_WAIT */
1682                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1683
1684                 bzero((char *) &serv_addr, sizeof(serv_addr));
1685                 serv_addr.sin_family = AF_INET;
1686                 if (interface == NULL)
1687                         serv_addr.sin_addr.s_addr = INADDR_ANY;
1688                 else
1689                         interface_to_sa(interface, &serv_addr,
1690                                                 sizeof(serv_addr));
1691                 serv_addr.sin_port = htons(port);
1692
1693                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
1694                                                              sizeof(serv_addr));
1695                 if (n < 0) {
1696                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1697                                                                 port, n, errno);
1698                         return NULL;
1699                 }
1700
1701                 wsi = malloc(sizeof(struct libwebsocket));
1702                 memset(wsi, 0, sizeof (struct libwebsocket));
1703                 wsi->sock = sockfd;
1704                 wsi->mode = LWS_CONNMODE_SERVER_LISTENER;
1705                 insert_wsi(this, wsi);
1706
1707                 listen(sockfd, 5);
1708                 fprintf(stderr, " Listening on port %d\n", port);
1709
1710                 /* list in the internal poll array */
1711
1712                 this->fds[this->fds_count].fd = sockfd;
1713                 this->fds[this->fds_count++].events = POLLIN;
1714
1715                 /* external POLL support via protocol 0 */
1716                 this->protocols[0].callback(this, wsi,
1717                         LWS_CALLBACK_ADD_POLL_FD,
1718                         (void *)(long)sockfd, NULL, POLLIN);
1719
1720         }
1721
1722         /* drop any root privs for this process */
1723
1724         if (gid != -1)
1725                 if (setgid(gid))
1726                         fprintf(stderr, "setgid: %s\n", strerror(errno));
1727         if (uid != -1)
1728                 if (setuid(uid))
1729                         fprintf(stderr, "setuid: %s\n", strerror(errno));
1730
1731
1732         /* set up our internal broadcast trigger sockets per-protocol */
1733
1734         for (this->count_protocols = 0;
1735                         protocols[this->count_protocols].callback;
1736                                                       this->count_protocols++) {
1737                 protocols[this->count_protocols].owning_server = this;
1738                 protocols[this->count_protocols].protocol_index =
1739                                                           this->count_protocols;
1740
1741                 fd = socket(AF_INET, SOCK_STREAM, 0);
1742                 if (fd < 0) {
1743                         fprintf(stderr, "ERROR opening socket");
1744                         return NULL;
1745                 }
1746
1747                 /* allow us to restart even if old sockets in TIME_WAIT */
1748                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
1749
1750                 bzero((char *) &serv_addr, sizeof(serv_addr));
1751                 serv_addr.sin_family = AF_INET;
1752                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1753                 serv_addr.sin_port = 0; /* pick the port for us */
1754
1755                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
1756                 if (n < 0) {
1757                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
1758                                                                 port, n, errno);
1759                         return NULL;
1760                 }
1761
1762                 slen = sizeof cli_addr;
1763                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
1764                 if (n < 0) {
1765                         fprintf(stderr, "getsockname failed\n");
1766                         return NULL;
1767                 }
1768                 protocols[this->count_protocols].broadcast_socket_port =
1769                                                        ntohs(cli_addr.sin_port);
1770                 listen(fd, 5);
1771
1772                 debug("  Protocol %s broadcast socket %d\n",
1773                                 protocols[this->count_protocols].name,
1774                                                       ntohs(cli_addr.sin_port));
1775
1776                 /* dummy wsi per broadcast proxy socket */
1777
1778                 wsi = malloc(sizeof(struct libwebsocket));
1779                 memset(wsi, 0, sizeof (struct libwebsocket));
1780                 wsi->sock = fd;
1781                 wsi->mode = LWS_CONNMODE_BROADCAST_PROXY_LISTENER;
1782                 /* note which protocol we are proxying */
1783                 wsi->protocol_index_for_broadcast_proxy = this->count_protocols;
1784                 insert_wsi(this, wsi);
1785
1786                 /* list in internal poll array */
1787
1788                 this->fds[this->fds_count].fd = fd;
1789                 this->fds[this->fds_count].events = POLLIN;
1790                 this->fds[this->fds_count].revents = 0;
1791                 this->fds_count++;
1792
1793                 /* external POLL support via protocol 0 */
1794                 this->protocols[0].callback(this, wsi,
1795                         LWS_CALLBACK_ADD_POLL_FD,
1796                         (void *)(long)fd, NULL, POLLIN);
1797         }
1798
1799         return this;
1800 }
1801
1802
1803 #ifndef LWS_NO_FORK
1804
1805 /**
1806  * libwebsockets_fork_service_loop() - Optional helper function forks off
1807  *                                a process for the websocket server loop.
1808  *                              You don't have to use this but if not, you
1809  *                              have to make sure you are calling
1810  *                              libwebsocket_service periodically to service
1811  *                              the websocket traffic
1812  * @this:       server context returned by creation function
1813  */
1814
1815 int
1816 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
1817 {
1818         int fd;
1819         struct sockaddr_in cli_addr;
1820         int n;
1821         int p;
1822
1823         n = fork();
1824         if (n < 0)
1825                 return n;
1826
1827         if (!n) {
1828
1829                 /* main process context */
1830
1831                 /*
1832                  * set up the proxy sockets to allow broadcast from
1833                  * service process context
1834                  */
1835
1836                 for (p = 0; p < this->count_protocols; p++) {
1837                         fd = socket(AF_INET, SOCK_STREAM, 0);
1838                         if (fd < 0) {
1839                                 fprintf(stderr, "Unable to create socket\n");
1840                                 return -1;
1841                         }
1842                         cli_addr.sin_family = AF_INET;
1843                         cli_addr.sin_port = htons(
1844                              this->protocols[p].broadcast_socket_port);
1845                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
1846                         n = connect(fd, (struct sockaddr *)&cli_addr,
1847                                                                sizeof cli_addr);
1848                         if (n < 0) {
1849                                 fprintf(stderr, "Unable to connect to "
1850                                                 "broadcast socket %d, %s\n",
1851                                                 n, strerror(errno));
1852                                 return -1;
1853                         }
1854
1855                         this->protocols[p].broadcast_socket_user_fd = fd;
1856                 }
1857
1858                 return 0;
1859         }
1860
1861         /* we want a SIGHUP when our parent goes down */
1862         prctl(PR_SET_PDEATHSIG, SIGHUP);
1863
1864         /* in this forked process, sit and service websocket connections */
1865
1866         while (1)
1867                 if (libwebsocket_service(this, 1000))
1868                         return -1;
1869
1870         return 0;
1871 }
1872
1873 #endif
1874
1875 /**
1876  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1877  *                                connection.
1878  * @wsi:        pointer to struct websocket you want to know the protocol of
1879  *
1880  *
1881  *      This is useful to get the protocol to broadcast back to from inside
1882  * the callback.
1883  */
1884
1885 const struct libwebsocket_protocols *
1886 libwebsockets_get_protocol(struct libwebsocket *wsi)
1887 {
1888         return wsi->protocol;
1889 }
1890
1891 /**
1892  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1893  *                                connections of the given protocol.
1894  * @protocol:   pointer to the protocol you will broadcast to all members of
1895  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1896  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1897  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1898  *              case you are calling this function from callback context.
1899  * @len:        length of payload data in buf, starting from buf.
1900  *
1901  *      This function allows bulk sending of a packet to every connection using
1902  * the given protocol.  It does not send the data directly; instead it calls
1903  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1904  * wants to actually send the data for that connection, the callback itself
1905  * should call libwebsocket_write().
1906  *
1907  * libwebsockets_broadcast() can be called from another fork context without
1908  * having to take any care about data visibility between the processes, it'll
1909  * "just work".
1910  */
1911
1912
1913 int
1914 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1915                                                  unsigned char *buf, size_t len)
1916 {
1917         struct libwebsocket_context *this = protocol->owning_server;
1918         int n;
1919         int m;
1920         struct libwebsocket * wsi;
1921
1922         if (!protocol->broadcast_socket_user_fd) {
1923                 /*
1924                  * We are either running unforked / flat, or we are being
1925                  * called from poll thread context
1926                  * eg, from a callback.  In that case don't use sockets for
1927                  * broadcast IPC (since we can't open a socket connection to
1928                  * a socket listening on our own thread) but directly do the
1929                  * send action.
1930                  *
1931                  * Locking is not needed because we are by definition being
1932                  * called in the poll thread context and are serialized.
1933                  */
1934
1935                 for (n = 0; n < FD_HASHTABLE_MODULUS; n++) {
1936
1937                         for (m = 0; m < this->fd_hashtable[n].length; m++) {
1938
1939                                 wsi = this->fd_hashtable[n].wsi[m];
1940
1941                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
1942                                         continue;
1943
1944                                 /*
1945                                  * never broadcast to
1946                                  * non-established connections
1947                                  */
1948                                 if (wsi->state != WSI_STATE_ESTABLISHED)
1949                                         continue;
1950
1951                                 /* only broadcast to guys using
1952                                  * requested protocol
1953                                  */
1954                                 if (wsi->protocol != protocol)
1955                                         continue;
1956
1957                                 wsi->protocol->callback(this, wsi,
1958                                          LWS_CALLBACK_BROADCAST,
1959                                          wsi->user_space,
1960                                          buf, len);
1961                         }
1962                 }
1963
1964                 return 0;
1965         }
1966
1967         /*
1968          * We're being called from a different process context than the server
1969          * loop.  Instead of broadcasting directly, we send our
1970          * payload on a socket to do the IPC; the server process will serialize
1971          * the broadcast action in its main poll() loop.
1972          *
1973          * There's one broadcast socket listening for each protocol supported
1974          * set up when the websocket server initializes
1975          */
1976
1977         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
1978
1979         return n;
1980 }