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 void
  25 libwebsocket_close_and_free_session(struct libwebsocket *wsi)
  26 {
  27         int n;
  28
  29         if ((unsigned long)wsi < LWS_MAX_PROTOCOLS)
  30                 return;
  31
  32         n = wsi->state;
  33
  34         wsi->state = WSI_STATE_DEAD_SOCKET;
  35
  36         if (wsi->protocol->callback && n == WSI_STATE_ESTABLISHED)
  37                 wsi->protocol->callback(wsi, LWS_CALLBACK_CLOSED,
  38                                                       wsi->user_space, NULL, 0);
  39
  40         for (n = 0; n < WSI_TOKEN_COUNT; n++)
  41                 if (wsi->utf8_token[n].token)
  42                         free(wsi->utf8_token[n].token);
  43
  44 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
  45
  46 #ifdef LWS_OPENSSL_SUPPORT
  47         if (wsi->ssl) {
  48                 n = SSL_get_fd(wsi->ssl);
  49                 SSL_shutdown(wsi->ssl);
  50                 close(n);
  51                 SSL_free(wsi->ssl);
  52         } else {
  53 #endif
  54                 shutdown(wsi->sock, SHUT_RDWR);
  55                 close(wsi->sock);
  56 #ifdef LWS_OPENSSL_SUPPORT
  57         }
  58 #endif
  59         if (wsi->user_space)
  60                 free(wsi->user_space);
  61
  62         free(wsi);
  63 }
  64
  65 static int
  66 libwebsocket_poll_connections(struct libwebsocket_context *this)
  67 {
  68         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
  69                                                   LWS_SEND_BUFFER_POST_PADDING];
  70         int client = this->count_protocols + 1;
  71         struct libwebsocket *wsi;
  72         int n;
  73         size_t len;
  74
  75         /* check for activity on client sockets */
  76
  77         for (; client < this->fds_count; client++) {
  78
  79                 /* handle session socket closed */
  80
  81                 if (this->fds[client].revents & (POLLERR | POLLHUP)) {
  82
  83                         debug("Session Socket %d %p (fd=%d) dead\n",
  84                                 client, (void *)this->wsi[client],
  85                                                           this->fds[client].fd);
  86
  87                         libwebsocket_close_and_free_session(this->wsi[client]);
  88                         goto nuke_this;
  89                 }
  90
  91                 /* the guy requested a callback when it was OK to write */
  92
  93                 if ((unsigned long)this->wsi[client] > LWS_MAX_PROTOCOLS &&
  94                                           this->fds[client].revents & POLLOUT) {
  95
  96                         this->fds[client].events &= ~POLLOUT;
  97
  98                         this->wsi[client]->protocol->callback(this->wsi[client],
  99                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 100                                 this->wsi[client]->user_space,
 101                                 NULL, 0);
 102                 }
 103
 104                 /* any incoming data ready? */
 105
 106                 if (!(this->fds[client].revents & POLLIN))
 107                         continue;
 108
 109                 /* broadcast? */
 110
 111                 if ((unsigned long)this->wsi[client] < LWS_MAX_PROTOCOLS) {
 112
 113                         /* get the issued broadcast payload from the socket */
 114
 115                         len = read(this->fds[client].fd,
 116                                    buf + LWS_SEND_BUFFER_PRE_PADDING,
 117                                    MAX_BROADCAST_PAYLOAD);
 118
 119                         if (len < 0) {
 120                                 fprintf(stderr,
 121                                            "Error reading broadcast payload\n");
 122                                 continue;
 123                         }
 124
 125                         /* broadcast it to all guys with this protocol index */
 126
 127                         for (n = this->count_protocols + 1;
 128                                                      n < this->fds_count; n++) {
 129
 130                                 wsi = this->wsi[n];
 131
 132                                 if ((unsigned long)wsi < LWS_MAX_PROTOCOLS)
 133                                         continue;
 134
 135                                 /*
 136                                  * never broadcast to non-established
 137                                  * connection
 138                                  */
 139
 140                                 if (wsi->state != WSI_STATE_ESTABLISHED)
 141                                         continue;
 142
 143                                 /* only to clients connected to us */
 144
 145                                 if (wsi->client_mode)
 146                                         continue;
 147
 148                                 /*
 149                                  * only broadcast to connections using
 150                                  * the requested protocol
 151                                  */
 152
 153                                 if (wsi->protocol->protocol_index !=
 154                                           (int)(unsigned long)this->wsi[client])
 155                                         continue;
 156
 157                                 /* broadcast it to this connection */
 158
 159                                 wsi->protocol->callback(wsi,
 160                                         LWS_CALLBACK_BROADCAST,
 161                                         wsi->user_space,
 162                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 163                         }
 164
 165                         continue;
 166                 }
 167
 168 #ifdef LWS_OPENSSL_SUPPORT
 169                 if (this->wsi[client]->ssl)
 170                         n = SSL_read(this->wsi[client]->ssl, buf, sizeof buf);
 171                 else
 172 #endif
 173                         n = recv(this->fds[client].fd, buf, sizeof buf, 0);
 174
 175                 if (n < 0) {
 176                         fprintf(stderr, "Socket read returned %d\n", n);
 177                         continue;
 178                 }
 179                 if (!n) {
 180                         libwebsocket_close_and_free_session(this->wsi[client]);
 181                         goto nuke_this;
 182                 }
 183
 184                 /* service incoming data */
 185
 186                 n = libwebsocket_read(this->wsi[client], buf, n);
 187                 if (n >= 0)
 188                         continue;
 189                 /*
 190                  * it closed and nuked wsi[client], so remove the
 191                  * socket handle and wsi from our service list
 192                  */
 193 nuke_this:
 194
 195                 debug("nuking wsi %p, fsd_count = %d\n",
 196                                 (void *)this->wsi[client], this->fds_count - 1);
 197
 198                 this->fds_count--;
 199                 for (n = client; n < this->fds_count; n++) {
 200                         this->fds[n] = this->fds[n + 1];
 201                         this->wsi[n] = this->wsi[n + 1];
 202                 }
 203
 204                 return 0;
 205
 206         }
 207
 208         return 0;
 209 }
 210
 211 /**
 212  * libwebsocket_context_destroy() - Destroy the websocket context
 213  * @this:       Websocket context
 214  *
 215  *      This function closes any active connections and then frees the
 216  *      context.  After calling this, any further use of the context is
 217  *      undefined.
 218  */
 219 void
 220 libwebsocket_context_destroy(struct libwebsocket_context *this)
 221 {
 222         int client;
 223
 224         /* close listening skt and per-protocol broadcast sockets */
 225         for (client = this->count_protocols + 1; client < this->fds_count; client++)
 226                 if (this->wsi[client]->client_mode)
 227                         libwebsocket_client_close(this->wsi[client]);
 228                 else
 229                         libwebsocket_close_and_free_session(this->wsi[client]);
 230
 231 #ifdef LWS_OPENSSL_SUPPORT
 232         if (this->ssl_ctx)
 233                 SSL_CTX_free(this->ssl_ctx);
 234 #endif
 235
 236         if (this)
 237                 free(this);
 238 }
 239
 240 /**
 241  * libwebsocket_service() - Service any pending websocket activity
 242  * @this:       Websocket context
 243  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
 244  *              service otherwise block and service immediately, returning
 245  *              after the timeout if nothing needed service.
 246  *
 247  *      This function deals with any pending websocket traffic, for three
 248  *      kinds of event.  It handles these events on both server and client
 249  *      types of connection the same.
 250  *
 251  *      1) Accept new connections to our context's server
 252  *
 253  *      2) Perform pending broadcast writes initiated from other forked
 254  *         processes (effectively serializing asynchronous broadcasts)
 255  *
 256  *      3) Call the receive callback for incoming frame data received by
 257  *          server or client connections.
 258  *
 259  *      You need to call this service function periodically to all the above
 260  *      functions to happen; if your application is single-threaded you can
 261  *      just call it in your main event loop.
 262  *
 263  *      Alternatively you can fork a new process that asynchronously handles
 264  *      calling this service in a loop.  In that case you are happy if this
 265  *      call blocks your thread until it needs to take care of something and
 266  *      would call it with a large nonzero timeout.  Your loop then takes no
 267  *      CPU while there is nothing happening.
 268  *
 269  *      If you are calling it in a single-threaded app, you don't want it to
 270  *      wait around blocking other things in your loop from happening, so you
 271  *      would call it with a timeout_ms of 0, so it returns immediately if
 272  *      nothing is pending, or as soon as it services whatever was pending.
 273  */
 274
 275
 276 int
 277 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
 278 {
 279         int n;
 280         int client;
 281         unsigned int clilen;
 282         struct sockaddr_in cli_addr;
 283         int fd;
 284
 285         /* stay dead once we are dead */
 286
 287         if (this == NULL)
 288                 return 1;
 289
 290         /* don't check listen socket if we are not listening */
 291
 292         if (this->listen_port)
 293                 n = poll(this->fds, this->fds_count, timeout_ms);
 294         else
 295                 n = poll(&this->fds[1], this->fds_count - 1, timeout_ms);
 296
 297
 298         if (n < 0 || this->fds[0].revents & (POLLERR | POLLHUP)) {
 299                 fprintf(stderr, "Listen Socket dead\n");
 300                 goto fatal;
 301         }
 302         if (n == 0) /* poll timeout */
 303                 return 0;
 304
 305         /* handle accept on listening socket? */
 306
 307         for (client = 0; client < this->count_protocols + 1; client++) {
 308
 309                 if (!this->fds[client].revents & POLLIN)
 310                         continue;
 311
 312                 /* listen socket got an unencrypted connection... */
 313
 314                 clilen = sizeof(cli_addr);
 315                 fd  = accept(this->fds[client].fd,
 316                              (struct sockaddr *)&cli_addr, &clilen);
 317                 if (fd < 0) {
 318                         fprintf(stderr, "ERROR on accept");
 319                         continue;
 320                 }
 321
 322                 if (this->fds_count >= MAX_CLIENTS) {
 323                         fprintf(stderr, "too busy");
 324                         close(fd);
 325                         continue;
 326                 }
 327
 328                 if (client) {
 329                         /*
 330                          * accepting a connection to broadcast socket
 331                          * set wsi to be protocol index not pointer
 332                          */
 333
 334                         this->wsi[this->fds_count] =
 335                               (struct libwebsocket *)(long)(client - 1);
 336
 337                         goto fill_in_fds;
 338                 }
 339
 340                 /* accepting connection to main listener */
 341
 342                 this->wsi[this->fds_count] =
 343                                     malloc(sizeof(struct libwebsocket));
 344                 if (!this->wsi[this->fds_count]) {
 345                         fprintf(stderr, "Out of memory for new connection\n");
 346                         continue;
 347                 }
 348
 349 #ifdef LWS_OPENSSL_SUPPORT
 350                 this->wsi[this->fds_count]->ssl = NULL;
 351
 352                 if (this->use_ssl) {
 353
 354                         this->wsi[this->fds_count]->ssl =
 355                                                          SSL_new(this->ssl_ctx);
 356                         if (this->wsi[this->fds_count]->ssl == NULL) {
 357                                 fprintf(stderr, "SSL_new failed: %s\n",
 358                                     ERR_error_string(SSL_get_error(
 359                                     this->wsi[this->fds_count]->ssl, 0),
 360                                                                  NULL));
 361                                 free(this->wsi[this->fds_count]);
 362                                 continue;
 363                         }
 364
 365                         SSL_set_fd(this->wsi[this->fds_count]->ssl, fd);
 366
 367                         n = SSL_accept(this->wsi[this->fds_count]->ssl);
 368                         if (n != 1) {
 369                                 /*
 370                                  * browsers seem to probe with various
 371                                  * ssl params which fail then retry
 372                                  * and succeed
 373                                  */
 374                                 debug("SSL_accept failed skt %u: %s\n",
 375                                       fd,
 376                                       ERR_error_string(SSL_get_error(
 377                                       this->wsi[this->fds_count]->ssl,
 378                                                              n), NULL));
 379                                 SSL_free(
 380                                        this->wsi[this->fds_count]->ssl);
 381                                 free(this->wsi[this->fds_count]);
 382                                 continue;
 383                         }
 384                         debug("accepted new SSL conn  "
 385                               "port %u on fd=%d SSL ver %s\n",
 386                                 ntohs(cli_addr.sin_port), fd,
 387                                   SSL_get_version(this->wsi[
 388                                                 this->fds_count]->ssl));
 389
 390                 } else
 391 #endif
 392                         debug("accepted new conn  port %u on fd=%d\n",
 393                                           ntohs(cli_addr.sin_port), fd);
 394
 395                 /* intialize the instance struct */
 396
 397                 this->wsi[this->fds_count]->sock = fd;
 398                 this->wsi[this->fds_count]->state = WSI_STATE_HTTP;
 399                 this->wsi[this->fds_count]->name_buffer_pos = 0;
 400                 this->wsi[this->fds_count]->client_mode = 0;
 401
 402                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 403                         this->wsi[this->fds_count]->
 404                                              utf8_token[n].token = NULL;
 405                         this->wsi[this->fds_count]->
 406                                             utf8_token[n].token_len = 0;
 407                 }
 408
 409                 /*
 410                  * these can only be set once the protocol is known
 411                  * we set an unestablished connection's protocol pointer
 412                  * to the start of the supported list, so it can look
 413                  * for matching ones during the handshake
 414                  */
 415                 this->wsi[this->fds_count]->protocol = this->protocols;
 416                 this->wsi[this->fds_count]->user_space = NULL;
 417
 418                 /*
 419                  * Default protocol is 76 / 00
 420                  * After 76, there's a header specified to inform which
 421                  * draft the client wants, when that's seen we modify
 422                  * the individual connection's spec revision accordingly
 423                  */
 424                 this->wsi[this->fds_count]->ietf_spec_revision = 0;
 425
 426 fill_in_fds:
 427
 428                 /*
 429                  * make sure NO events are seen yet on this new socket
 430                  * (otherwise we inherit old fds[client].revents from
 431                  * previous socket there and die mysteriously! )
 432                  */
 433                 this->fds[this->fds_count].revents = 0;
 434
 435                 this->fds[this->fds_count].events = POLLIN;
 436                 this->fds[this->fds_count++].fd = fd;
 437
 438         }
 439
 440         /* service anything incoming on websocket connection */
 441
 442         libwebsocket_poll_connections(this);
 443
 444         /* this round is done */
 445
 446         return 0;
 447
 448 fatal:
 449
 450         fprintf(stderr, "service hits fatal\n");
 451
 452         /* close listening skt and per-protocol broadcast sockets */
 453         for (client = 0; client < this->fds_count; client++)
 454                 close(this->fds[0].fd);
 455
 456 #ifdef LWS_OPENSSL_SUPPORT
 457         if (this->ssl_ctx)
 458                 SSL_CTX_free(this->ssl_ctx);
 459 #endif
 460
 461         if (this)
 462                 free(this);
 463
 464         this = NULL;
 465
 466         /* inform caller we are dead */
 467
 468         return 1;
 469 }
 470
 471 /**
 472  * libwebsocket_callback_on_writable() - Request a callback when this socket
 473  *                                       becomes able to be written to without
 474  *                                       blocking
 475  *
 476  * @wsi:        Websocket connection instance to get callback for
 477  */
 478
 479 int
 480 libwebsocket_callback_on_writable(struct libwebsocket *wsi)
 481 {
 482         struct libwebsocket_context *this = wsi->protocol->owning_server;
 483         int n;
 484
 485         for (n = this->count_protocols + 1; n < this->fds_count; n++)
 486                 if (this->wsi[n] == wsi) {
 487                         this->fds[n].events |= POLLOUT;
 488                         return 0;
 489                 }
 490
 491         fprintf(stderr, "libwebsocket_callback_on_writable "
 492                                                         "didn't find socket\n");
 493         return 1;
 494 }
 495
 496 /**
 497  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
 498  *                      all connections using the given protocol when it
 499  *                      becomes possible to write to each socket without
 500  *                      blocking in turn.
 501  *
 502  * @protocol:   Protocol whose connections will get callbacks
 503  */
 504
 505 int
 506 libwebsocket_callback_on_writable_all_protocol(
 507                                   const struct libwebsocket_protocols *protocol)
 508 {
 509         struct libwebsocket_context *this = protocol->owning_server;
 510         int n;
 511
 512         for (n = this->count_protocols + 1; n < this->fds_count; n++)
 513                 if ((unsigned long)this->wsi[n] > LWS_MAX_PROTOCOLS)
 514                         if (this->wsi[n]->protocol == protocol)
 515                                 this->fds[n].events |= POLLOUT;
 516
 517         return 0;
 518 }
 519
 520
 521 /**
 522  * libwebsocket_get_socket_fd() - returns the socket file descriptor
 523  *
 524  * You will not need this unless you are doing something special
 525  *
 526  * @wsi:        Websocket connection instance
 527  */
 528
 529 int
 530 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
 531 {
 532         return wsi->sock;
 533 }
 534
 535 /**
 536  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
 537  *                              receieved packets.
 538  *
 539  * If the output side of a server process becomes choked, this allows flow
 540  * control for the input side.
 541  *
 542  * @wsi:        Websocket connection instance to get callback for
 543  * @enable:     0 = disable read servicing for this connection, 1 = enable
 544  */
 545
 546 int
 547 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
 548 {
 549         struct libwebsocket_context *this = wsi->protocol->owning_server;
 550         int n;
 551
 552         for (n = this->count_protocols + 1; n < this->fds_count; n++)
 553                 if (this->wsi[n] == wsi) {
 554                         if (enable)
 555                                 this->fds[n].events |= POLLIN;
 556                         else
 557                                 this->fds[n].events &= ~POLLIN;
 558
 559                         return 0;
 560                 }
 561
 562         fprintf(stderr, "libwebsocket_callback_on_writable "
 563                                                      "unable to find socket\n");
 564         return 1;
 565 }
 566
 567 /**
 568  * libwebsocket_canonical_hostname() - returns this host's hostname
 569  *
 570  * This is typically used by client code to fill in the host parameter
 571  * when making a client connection.  You can only call it after the context
 572  * has been created.
 573  *
 574  * @this:       Websocket context
 575  */
 576
 577
 578 extern const char *
 579 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
 580 {
 581         return (const char *)this->canonical_hostname;
 582 }
 583
 584
 585 static void sigpipe_handler(int x)
 586 {
 587 }
 588
 589
 590 /**
 591  * libwebsocket_create_context() - Create the websocket handler
 592  * @port:       Port to listen on... you can use 0 to suppress listening on
 593  *              any port, that's what you want if you are not running a
 594  *              websocket server at all but just using it as a client
 595  * @protocols:  Array of structures listing supported protocols and a protocol-
 596  *              specific callback for each one.  The list is ended with an
 597  *              entry that has a NULL callback pointer.
 598  *              It's not const because we write the owning_server member
 599  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
 600  *                      to listen using SSL, set to the filepath to fetch the
 601  *                      server cert from, otherwise NULL for unencrypted
 602  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
 603  *                      else ignored
 604  * @gid:        group id to change to after setting listen socket, or -1.
 605  * @uid:        user id to change to after setting listen socket, or -1.
 606  *
 607  *      This function creates the listening socket and takes care
 608  *      of all initialization in one step.
 609  *
 610  *      After initialization, it returns a struct libwebsocket_context * that
 611  *      represents this server.  After calling, user code needs to take care
 612  *      of calling libwebsocket_service() with the context pointer to get the
 613  *      server's sockets serviced.  This can be done in the same process context
 614  *      or a forked process, or another thread,
 615  *
 616  *      The protocol callback functions are called for a handful of events
 617  *      including http requests coming in, websocket connections becoming
 618  *      established, and data arriving; it's also called periodically to allow
 619  *      async transmission.
 620  *
 621  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
 622  *      at that time websocket protocol has not been negotiated.  Other
 623  *      protocols after the first one never see any HTTP callack activity.
 624  *
 625  *      The server created is a simple http server by default; part of the
 626  *      websocket standard is upgrading this http connection to a websocket one.
 627  *
 628  *      This allows the same server to provide files like scripts and favicon /
 629  *      images or whatever over http and dynamic data over websockets all in
 630  *      one place; they're all handled in the user callback.
 631  */
 632
 633 struct libwebsocket_context *
 634 libwebsocket_create_context(int port,
 635                                struct libwebsocket_protocols *protocols,
 636                                const char *ssl_cert_filepath,
 637                                const char *ssl_private_key_filepath,
 638                                int gid, int uid, unsigned int options)
 639 {
 640         int n;
 641         int sockfd = 0;
 642         int fd;
 643         struct sockaddr_in serv_addr, cli_addr;
 644         int opt = 1;
 645         struct libwebsocket_context *this = NULL;
 646         unsigned int slen;
 647         char *p;
 648         char hostname[1024];
 649         struct hostent *he;
 650
 651 #ifdef LWS_OPENSSL_SUPPORT
 652         SSL_METHOD *method;
 653         char ssl_err_buf[512];
 654 #endif
 655
 656         this = malloc(sizeof(struct libwebsocket_context));
 657         if (!this) {
 658                 fprintf(stderr, "No memory for websocket context\n");
 659                 return NULL;
 660         }
 661         this->protocols = protocols;
 662         this->listen_port = port;
 663         this->http_proxy_port = 0;
 664         this->http_proxy_address[0] = '\0';
 665         this->options = options;
 666
 667         /* find canonical hostname */
 668
 669         hostname[(sizeof hostname) - 1] = '\0';
 670         gethostname(hostname, (sizeof hostname) - 1);
 671         he = gethostbyname(hostname);
 672         strncpy(this->canonical_hostname, he->h_name,
 673                                            sizeof this->canonical_hostname - 1);
 674         this->canonical_hostname[sizeof this->canonical_hostname - 1] = '\0';
 675
 676         /* split the proxy ads:port if given */
 677
 678         p = getenv("http_proxy");
 679         if (p) {
 680                 strncpy(this->http_proxy_address, p,
 681                                            sizeof this->http_proxy_address - 1);
 682                 this->http_proxy_address[
 683                                     sizeof this->http_proxy_address - 1] = '\0';
 684
 685                 p = strchr(this->http_proxy_address, ':');
 686                 if (p == NULL) {
 687                         fprintf(stderr, "http_proxy needs to be ads:port\n");
 688                         return NULL;
 689                 }
 690                 *p = '\0';
 691                 this->http_proxy_port = atoi(p + 1);
 692
 693                 fprintf(stderr, "Using proxy %s:%u\n",
 694                                 this->http_proxy_address,
 695                                                         this->http_proxy_port);
 696         }
 697
 698         if (port) {
 699
 700 #ifdef LWS_OPENSSL_SUPPORT
 701                 this->use_ssl = ssl_cert_filepath != NULL &&
 702                                                ssl_private_key_filepath != NULL;
 703                 if (this->use_ssl)
 704                         fprintf(stderr, " Compiled with SSL support, "
 705                                                                   "using it\n");
 706                 else
 707                         fprintf(stderr, " Compiled with SSL support, "
 708                                                               "not using it\n");
 709
 710 #else
 711                 if (ssl_cert_filepath != NULL &&
 712                                              ssl_private_key_filepath != NULL) {
 713                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
 714                         return NULL;
 715                 }
 716                 fprintf(stderr, " Compiled without SSL support, "
 717                                                        "serving unencrypted\n");
 718 #endif
 719         }
 720
 721         /* ignore SIGPIPE */
 722
 723         signal(SIGPIPE, sigpipe_handler);
 724
 725
 726 #ifdef LWS_OPENSSL_SUPPORT
 727
 728         /* basic openssl init */
 729
 730         SSL_library_init();
 731
 732         OpenSSL_add_all_algorithms();
 733         SSL_load_error_strings();
 734
 735         /*
 736          * Firefox insists on SSLv23 not SSLv3
 737          * Konq disables SSLv2 by default now, SSLv23 works
 738          */
 739
 740         method = (SSL_METHOD *)SSLv23_server_method();
 741         if (!method) {
 742                 fprintf(stderr, "problem creating ssl method: %s\n",
 743                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 744                 return NULL;
 745         }
 746         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
 747         if (!this->ssl_ctx) {
 748                 fprintf(stderr, "problem creating ssl context: %s\n",
 749                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 750                 return NULL;
 751         }
 752
 753         /* client context */
 754
 755         method = (SSL_METHOD *)SSLv23_client_method();
 756         if (!method) {
 757                 fprintf(stderr, "problem creating ssl method: %s\n",
 758                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 759                 return NULL;
 760         }
 761         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
 762         if (!this->ssl_client_ctx) {
 763                 fprintf(stderr, "problem creating ssl context: %s\n",
 764                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 765                 return NULL;
 766         }
 767
 768
 769         /* openssl init for cert verification (used with client sockets) */
 770
 771         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
 772                                                     LWS_OPENSSL_CLIENT_CERTS)) {
 773                 fprintf(stderr, "Unable to load SSL Client certs from %s "
 774                         "(set by --with-client-cert-dir= in configure) -- "
 775                         " client ssl isn't going to work",
 776                                                       LWS_OPENSSL_CLIENT_CERTS);
 777         }
 778
 779         if (this->use_ssl) {
 780
 781                 /* openssl init for server sockets */
 782
 783                 /* set the local certificate from CertFile */
 784                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
 785                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
 786                 if (n != 1) {
 787                         fprintf(stderr, "problem getting cert '%s': %s\n",
 788                                 ssl_cert_filepath,
 789                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
 790                         return NULL;
 791                 }
 792                 /* set the private key from KeyFile */
 793                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
 794                                                 ssl_private_key_filepath,
 795                                                        SSL_FILETYPE_PEM) != 1) {
 796                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
 797                                                 ssl_private_key_filepath,
 798                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
 799                         return NULL;
 800                 }
 801                 /* verify private key */
 802                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
 803                         fprintf(stderr, "Private SSL key doesn't match cert\n");
 804                         return NULL;
 805                 }
 806
 807                 /* SSL is happy and has a cert it's content with */
 808         }
 809 #endif
 810
 811         /* selftest */
 812
 813         if (lws_b64_selftest())
 814                 return NULL;
 815
 816         /* set up our external listening socket we serve on */
 817
 818         if (port) {
 819
 820                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
 821                 if (sockfd < 0) {
 822                         fprintf(stderr, "ERROR opening socket");
 823                         return NULL;
 824                 }
 825
 826                 /* allow us to restart even if old sockets in TIME_WAIT */
 827                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 828
 829                 bzero((char *) &serv_addr, sizeof(serv_addr));
 830                 serv_addr.sin_family = AF_INET;
 831                 serv_addr.sin_addr.s_addr = INADDR_ANY;
 832                 serv_addr.sin_port = htons(port);
 833
 834                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
 835                                                              sizeof(serv_addr));
 836                 if (n < 0) {
 837                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
 838                                                                 port, n, errno);
 839                         return NULL;
 840                 }
 841         }
 842
 843         /* drop any root privs for this process */
 844
 845         if (gid != -1)
 846                 if (setgid(gid))
 847                         fprintf(stderr, "setgid: %s\n", strerror(errno));
 848         if (uid != -1)
 849                 if (setuid(uid))
 850                         fprintf(stderr, "setuid: %s\n", strerror(errno));
 851
 852         /*
 853          * prepare the poll() fd array... it's like this
 854          *
 855          * [0] = external listening socket
 856          * [1 .. this->count_protocols] = per-protocol broadcast sockets
 857          * [this->count_protocols + 1 ... this->fds_count-1] = connection skts
 858          */
 859
 860         this->fds_count = 1;
 861         this->fds[0].fd = sockfd;
 862         this->fds[0].events = POLLIN;
 863         this->count_protocols = 0;
 864
 865         if (port) {
 866                 listen(sockfd, 5);
 867                 fprintf(stderr, " Listening on port %d\n", port);
 868         }
 869
 870         /* set up our internal broadcast trigger sockets per-protocol */
 871
 872         for (; protocols[this->count_protocols].callback;
 873                                                       this->count_protocols++) {
 874                 protocols[this->count_protocols].owning_server = this;
 875                 protocols[this->count_protocols].protocol_index =
 876                                                           this->count_protocols;
 877
 878                 fd = socket(AF_INET, SOCK_STREAM, 0);
 879                 if (fd < 0) {
 880                         fprintf(stderr, "ERROR opening socket");
 881                         return NULL;
 882                 }
 883
 884                 /* allow us to restart even if old sockets in TIME_WAIT */
 885                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 886
 887                 bzero((char *) &serv_addr, sizeof(serv_addr));
 888                 serv_addr.sin_family = AF_INET;
 889                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 890                 serv_addr.sin_port = 0; /* pick the port for us */
 891
 892                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
 893                 if (n < 0) {
 894                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
 895                                                                 port, n, errno);
 896                         return NULL;
 897                 }
 898
 899                 slen = sizeof cli_addr;
 900                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
 901                 if (n < 0) {
 902                         fprintf(stderr, "getsockname failed\n");
 903                         return NULL;
 904                 }
 905                 protocols[this->count_protocols].broadcast_socket_port =
 906                                                        ntohs(cli_addr.sin_port);
 907                 listen(fd, 5);
 908
 909                 debug("  Protocol %s broadcast socket %d\n",
 910                                 protocols[this->count_protocols].name,
 911                                                       ntohs(cli_addr.sin_port));
 912
 913                 this->fds[this->fds_count].fd = fd;
 914                 this->fds[this->fds_count].events = POLLIN;
 915                 /* wsi only exists for connections, not broadcast listener */
 916                 this->wsi[this->fds_count] = NULL;
 917                 this->fds_count++;
 918         }
 919
 920         return this;
 921 }
 922
 923
 924 #ifndef LWS_NO_FORK
 925
 926 /**
 927  * libwebsockets_fork_service_loop() - Optional helper function forks off
 928  *                                a process for the websocket server loop.
 929  *                              You don't have to use this but if not, you
 930  *                              have to make sure you are calling
 931  *                              libwebsocket_service periodically to service
 932  *                              the websocket traffic
 933  * @this:       server context returned by creation function
 934  */
 935
 936 int
 937 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
 938 {
 939         int client;
 940         int fd;
 941         struct sockaddr_in cli_addr;
 942         int n;
 943
 944         n = fork();
 945         if (n < 0)
 946                 return n;
 947
 948         if (!n) {
 949
 950                 /* main process context */
 951
 952                 for (client = 1; client < this->count_protocols + 1; client++) {
 953                         fd = socket(AF_INET, SOCK_STREAM, 0);
 954                         if (fd < 0) {
 955                                 fprintf(stderr, "Unable to create socket\n");
 956                                 return -1;
 957                         }
 958                         cli_addr.sin_family = AF_INET;
 959                         cli_addr.sin_port = htons(
 960                              this->protocols[client - 1].broadcast_socket_port);
 961                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 962                         n = connect(fd, (struct sockaddr *)&cli_addr,
 963                                                                sizeof cli_addr);
 964                         if (n < 0) {
 965                                 fprintf(stderr, "Unable to connect to "
 966                                                 "broadcast socket %d, %s\n",
 967                                                 client, strerror(errno));
 968                                 return -1;
 969                         }
 970
 971                         this->protocols[client - 1].broadcast_socket_user_fd =
 972                                                                              fd;
 973                 }
 974
 975
 976                 return 0;
 977         }
 978
 979         /* we want a SIGHUP when our parent goes down */
 980         prctl(PR_SET_PDEATHSIG, SIGHUP);
 981
 982         /* in this forked process, sit and service websocket connections */
 983
 984         while (1)
 985                 if (libwebsocket_service(this, 1000))
 986                         return -1;
 987
 988         return 0;
 989 }
 990
 991 #endif
 992
 993 /**
 994  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
 995  *                                connection.
 996  * @wsi:        pointer to struct websocket you want to know the protocol of
 997  *
 998  *
 999  *      This is useful to get the protocol to broadcast back to from inside
1000  * the callback.
1001  */
1002
1003 const struct libwebsocket_protocols *
1004 libwebsockets_get_protocol(struct libwebsocket *wsi)
1005 {
1006         return wsi->protocol;
1007 }
1008
1009 /**
1010  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1011  *                                connections of the given protocol.
1012  * @protocol:   pointer to the protocol you will broadcast to all members of
1013  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1014  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1015  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1016  *              case you are calling this function from callback context.
1017  * @len:        length of payload data in buf, starting from buf.
1018  *
1019  *      This function allows bulk sending of a packet to every connection using
1020  * the given protocol.  It does not send the data directly; instead it calls
1021  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1022  * wants to actually send the data for that connection, the callback itself
1023  * should call libwebsocket_write().
1024  *
1025  * libwebsockets_broadcast() can be called from another fork context without
1026  * having to take any care about data visibility between the processes, it'll
1027  * "just work".
1028  */
1029
1030
1031 int
1032 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1033                                                  unsigned char *buf, size_t len)
1034 {
1035         struct libwebsocket_context *this = protocol->owning_server;
1036         int n;
1037
1038         if (!protocol->broadcast_socket_user_fd) {
1039                 /*
1040                  * We are either running unforked / flat, or we are being
1041                  * called from poll thread context
1042                  * eg, from a callback.  In that case don't use sockets for
1043                  * broadcast IPC (since we can't open a socket connection to
1044                  * a socket listening on our own thread) but directly do the
1045                  * send action.
1046                  *
1047                  * Locking is not needed because we are by definition being
1048                  * called in the poll thread context and are serialized.
1049                  */
1050
1051                 for (n = this->count_protocols + 1; n < this->fds_count; n++) {
1052
1053                         if ((unsigned long)this->wsi[n] < LWS_MAX_PROTOCOLS)
1054                                 continue;
1055
1056                         /* never broadcast to non-established connection */
1057                         if (this->wsi[n]->state != WSI_STATE_ESTABLISHED)
1058                                 continue;
1059
1060                         /* only broadcast to guys using requested protocol */
1061                         if (this->wsi[n]->protocol != protocol)
1062                                 continue;
1063
1064                         this->wsi[n]->protocol->callback(this->wsi[n],
1065                                          LWS_CALLBACK_BROADCAST,
1066                                          this->wsi[n]->user_space,
1067                                          buf, len);
1068                 }
1069
1070                 return 0;
1071         }
1072
1073         /*
1074          * We're being called from a different process context than the server
1075          * loop.  Instead of broadcasting directly, we send our
1076          * payload on a socket to do the IPC; the server process will serialize
1077          * the broadcast action in its main poll() loop.
1078          *
1079          * There's one broadcast socket listening for each protocol supported
1080          * set up when the websocket server initializes
1081          */
1082
1083         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
1084
1085         return n;
1086 }