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)
 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
 666         /* find canonical hostname */
 667
 668         hostname[(sizeof hostname) - 1] = '\0';
 669         gethostname(hostname, (sizeof hostname) - 1);
 670         he = gethostbyname(hostname);
 671         strncpy(this->canonical_hostname, he->h_name,
 672                                            sizeof this->canonical_hostname - 1);
 673         this->canonical_hostname[sizeof this->canonical_hostname - 1] = '\0';
 674
 675         /* split the proxy ads:port if given */
 676
 677         p = getenv("http_proxy");
 678         if (p) {
 679                 strncpy(this->http_proxy_address, p,
 680                                            sizeof this->http_proxy_address - 1);
 681                 this->http_proxy_address[
 682                                     sizeof this->http_proxy_address - 1] = '\0';
 683
 684                 p = strchr(this->http_proxy_address, ':');
 685                 if (p == NULL) {
 686                         fprintf(stderr, "http_proxy needs to be ads:port\n");
 687                         return NULL;
 688                 }
 689                 *p = '\0';
 690                 this->http_proxy_port = atoi(p + 1);
 691
 692                 fprintf(stderr, "Using proxy %s:%u\n",
 693                                 this->http_proxy_address,
 694                                                         this->http_proxy_port);
 695         }
 696
 697         if (port) {
 698
 699 #ifdef LWS_OPENSSL_SUPPORT
 700                 this->use_ssl = ssl_cert_filepath != NULL &&
 701                                                ssl_private_key_filepath != NULL;
 702                 if (this->use_ssl)
 703                         fprintf(stderr, " Compiled with SSL support, "
 704                                                                   "using it\n");
 705                 else
 706                         fprintf(stderr, " Compiled with SSL support, "
 707                                                               "not using it\n");
 708
 709 #else
 710                 if (ssl_cert_filepath != NULL &&
 711                                              ssl_private_key_filepath != NULL) {
 712                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
 713                         return NULL;
 714                 }
 715                 fprintf(stderr, " Compiled without SSL support, "
 716                                                        "serving unencrypted\n");
 717 #endif
 718         }
 719
 720         /* ignore SIGPIPE */
 721
 722         signal(SIGPIPE, sigpipe_handler);
 723
 724
 725 #ifdef LWS_OPENSSL_SUPPORT
 726
 727         /* basic openssl init */
 728
 729         SSL_library_init();
 730
 731         OpenSSL_add_all_algorithms();
 732         SSL_load_error_strings();
 733
 734         /*
 735          * Firefox insists on SSLv23 not SSLv3
 736          * Konq disables SSLv2 by default now, SSLv23 works
 737          */
 738
 739         method = (SSL_METHOD *)SSLv23_server_method();
 740         if (!method) {
 741                 fprintf(stderr, "problem creating ssl method: %s\n",
 742                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 743                 return NULL;
 744         }
 745         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
 746         if (!this->ssl_ctx) {
 747                 fprintf(stderr, "problem creating ssl context: %s\n",
 748                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 749                 return NULL;
 750         }
 751
 752         /* client context */
 753
 754         method = (SSL_METHOD *)SSLv23_client_method();
 755         if (!method) {
 756                 fprintf(stderr, "problem creating ssl method: %s\n",
 757                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 758                 return NULL;
 759         }
 760         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
 761         if (!this->ssl_client_ctx) {
 762                 fprintf(stderr, "problem creating ssl context: %s\n",
 763                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 764                 return NULL;
 765         }
 766
 767
 768         /* openssl init for cert verification (used with client sockets) */
 769
 770         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
 771                                                     LWS_OPENSSL_CLIENT_CERTS)) {
 772                 fprintf(stderr, "Unable to load SSL Client certs from %s "
 773                         "(set by --with-client-cert-dir= in configure) -- "
 774                         " client ssl isn't going to work",
 775                                                       LWS_OPENSSL_CLIENT_CERTS);
 776         }
 777
 778         if (this->use_ssl) {
 779
 780                 /* openssl init for server sockets */
 781
 782                 /* set the local certificate from CertFile */
 783                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
 784                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
 785                 if (n != 1) {
 786                         fprintf(stderr, "problem getting cert '%s': %s\n",
 787                                 ssl_cert_filepath,
 788                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
 789                         return NULL;
 790                 }
 791                 /* set the private key from KeyFile */
 792                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
 793                                                 ssl_private_key_filepath,
 794                                                        SSL_FILETYPE_PEM) != 1) {
 795                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
 796                                                 ssl_private_key_filepath,
 797                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
 798                         return NULL;
 799                 }
 800                 /* verify private key */
 801                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
 802                         fprintf(stderr, "Private SSL key doesn't match cert\n");
 803                         return NULL;
 804                 }
 805
 806                 /* SSL is happy and has a cert it's content with */
 807         }
 808 #endif
 809
 810         /* selftest */
 811
 812         if (lws_b64_selftest())
 813                 return NULL;
 814
 815         /* set up our external listening socket we serve on */
 816
 817         if (port) {
 818
 819                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
 820                 if (sockfd < 0) {
 821                         fprintf(stderr, "ERROR opening socket");
 822                         return NULL;
 823                 }
 824
 825                 /* allow us to restart even if old sockets in TIME_WAIT */
 826                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 827
 828                 bzero((char *) &serv_addr, sizeof(serv_addr));
 829                 serv_addr.sin_family = AF_INET;
 830                 serv_addr.sin_addr.s_addr = INADDR_ANY;
 831                 serv_addr.sin_port = htons(port);
 832
 833                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
 834                                                              sizeof(serv_addr));
 835                 if (n < 0) {
 836                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
 837                                                                 port, n, errno);
 838                         return NULL;
 839                 }
 840         }
 841
 842         /* drop any root privs for this process */
 843
 844         if (gid != -1)
 845                 if (setgid(gid))
 846                         fprintf(stderr, "setgid: %s\n", strerror(errno));
 847         if (uid != -1)
 848                 if (setuid(uid))
 849                         fprintf(stderr, "setuid: %s\n", strerror(errno));
 850
 851         /*
 852          * prepare the poll() fd array... it's like this
 853          *
 854          * [0] = external listening socket
 855          * [1 .. this->count_protocols] = per-protocol broadcast sockets
 856          * [this->count_protocols + 1 ... this->fds_count-1] = connection skts
 857          */
 858
 859         this->fds_count = 1;
 860         this->fds[0].fd = sockfd;
 861         this->fds[0].events = POLLIN;
 862         this->count_protocols = 0;
 863
 864         if (port) {
 865                 listen(sockfd, 5);
 866                 fprintf(stderr, " Listening on port %d\n", port);
 867         }
 868
 869         /* set up our internal broadcast trigger sockets per-protocol */
 870
 871         for (; protocols[this->count_protocols].callback;
 872                                                       this->count_protocols++) {
 873                 protocols[this->count_protocols].owning_server = this;
 874                 protocols[this->count_protocols].protocol_index =
 875                                                           this->count_protocols;
 876
 877                 fd = socket(AF_INET, SOCK_STREAM, 0);
 878                 if (fd < 0) {
 879                         fprintf(stderr, "ERROR opening socket");
 880                         return NULL;
 881                 }
 882
 883                 /* allow us to restart even if old sockets in TIME_WAIT */
 884                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 885
 886                 bzero((char *) &serv_addr, sizeof(serv_addr));
 887                 serv_addr.sin_family = AF_INET;
 888                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 889                 serv_addr.sin_port = 0; /* pick the port for us */
 890
 891                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
 892                 if (n < 0) {
 893                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
 894                                                                 port, n, errno);
 895                         return NULL;
 896                 }
 897
 898                 slen = sizeof cli_addr;
 899                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
 900                 if (n < 0) {
 901                         fprintf(stderr, "getsockname failed\n");
 902                         return NULL;
 903                 }
 904                 protocols[this->count_protocols].broadcast_socket_port =
 905                                                        ntohs(cli_addr.sin_port);
 906                 listen(fd, 5);
 907
 908                 debug("  Protocol %s broadcast socket %d\n",
 909                                 protocols[this->count_protocols].name,
 910                                                       ntohs(cli_addr.sin_port));
 911
 912                 this->fds[this->fds_count].fd = fd;
 913                 this->fds[this->fds_count].events = POLLIN;
 914                 /* wsi only exists for connections, not broadcast listener */
 915                 this->wsi[this->fds_count] = NULL;
 916                 this->fds_count++;
 917         }
 918
 919         return this;
 920 }
 921
 922
 923 #ifndef LWS_NO_FORK
 924
 925 /**
 926  * libwebsockets_fork_service_loop() - Optional helper function forks off
 927  *                                a process for the websocket server loop.
 928  *                              You don't have to use this but if not, you
 929  *                              have to make sure you are calling
 930  *                              libwebsocket_service periodically to service
 931  *                              the websocket traffic
 932  * @this:       server context returned by creation function
 933  */
 934
 935 int
 936 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
 937 {
 938         int client;
 939         int fd;
 940         struct sockaddr_in cli_addr;
 941         int n;
 942
 943         n = fork();
 944         if (n < 0)
 945                 return n;
 946
 947         if (!n) {
 948
 949                 /* main process context */
 950
 951                 for (client = 1; client < this->count_protocols + 1; client++) {
 952                         fd = socket(AF_INET, SOCK_STREAM, 0);
 953                         if (fd < 0) {
 954                                 fprintf(stderr, "Unable to create socket\n");
 955                                 return -1;
 956                         }
 957                         cli_addr.sin_family = AF_INET;
 958                         cli_addr.sin_port = htons(
 959                              this->protocols[client - 1].broadcast_socket_port);
 960                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 961                         n = connect(fd, (struct sockaddr *)&cli_addr,
 962                                                                sizeof cli_addr);
 963                         if (n < 0) {
 964                                 fprintf(stderr, "Unable to connect to "
 965                                                 "broadcast socket %d, %s\n",
 966                                                 client, strerror(errno));
 967                                 return -1;
 968                         }
 969
 970                         this->protocols[client - 1].broadcast_socket_user_fd =
 971                                                                              fd;
 972                 }
 973
 974
 975                 return 0;
 976         }
 977
 978         /* we want a SIGHUP when our parent goes down */
 979         prctl(PR_SET_PDEATHSIG, SIGHUP);
 980
 981         /* in this forked process, sit and service websocket connections */
 982
 983         while (1)
 984                 if (libwebsocket_service(this, 1000))
 985                         return -1;
 986
 987         return 0;
 988 }
 989
 990 #endif
 991
 992 /**
 993  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
 994  *                                connection.
 995  * @wsi:        pointer to struct websocket you want to know the protocol of
 996  *
 997  *
 998  *      This is useful to get the protocol to broadcast back to from inside
 999  * the callback.
1000  */
1001
1002 const struct libwebsocket_protocols *
1003 libwebsockets_get_protocol(struct libwebsocket *wsi)
1004 {
1005         return wsi->protocol;
1006 }
1007
1008 /**
1009  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1010  *                                connections of the given protocol.
1011  * @protocol:   pointer to the protocol you will broadcast to all members of
1012  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1013  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1014  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1015  *              case you are calling this function from callback context.
1016  * @len:        length of payload data in buf, starting from buf.
1017  *
1018  *      This function allows bulk sending of a packet to every connection using
1019  * the given protocol.  It does not send the data directly; instead it calls
1020  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1021  * wants to actually send the data for that connection, the callback itself
1022  * should call libwebsocket_write().
1023  *
1024  * libwebsockets_broadcast() can be called from another fork context without
1025  * having to take any care about data visibility between the processes, it'll
1026  * "just work".
1027  */
1028
1029
1030 int
1031 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1032                                                  unsigned char *buf, size_t len)
1033 {
1034         struct libwebsocket_context *this = protocol->owning_server;
1035         int n;
1036
1037         if (!protocol->broadcast_socket_user_fd) {
1038                 /*
1039                  * We are either running unforked / flat, or we are being
1040                  * called from poll thread context
1041                  * eg, from a callback.  In that case don't use sockets for
1042                  * broadcast IPC (since we can't open a socket connection to
1043                  * a socket listening on our own thread) but directly do the
1044                  * send action.
1045                  *
1046                  * Locking is not needed because we are by definition being
1047                  * called in the poll thread context and are serialized.
1048                  */
1049
1050                 for (n = this->count_protocols + 1; n < this->fds_count; n++) {
1051
1052                         if ((unsigned long)this->wsi[n] < LWS_MAX_PROTOCOLS)
1053                                 continue;
1054
1055                         /* never broadcast to non-established connection */
1056                         if (this->wsi[n]->state != WSI_STATE_ESTABLISHED)
1057                                 continue;
1058
1059                         /* only broadcast to guys using requested protocol */
1060                         if (this->wsi[n]->protocol != protocol)
1061                                 continue;
1062
1063                         this->wsi[n]->protocol->callback(this->wsi[n],
1064                                          LWS_CALLBACK_BROADCAST,
1065                                          this->wsi[n]->user_space,
1066                                          buf, len);
1067                 }
1068
1069                 return 0;
1070         }
1071
1072         /*
1073          * We're being called from a different process context than the server
1074          * loop.  Instead of broadcasting directly, we send our
1075          * payload on a socket to do the IPC; the server process will serialize
1076          * the broadcast action in its main poll() loop.
1077          *
1078          * There's one broadcast socket listening for each protocol supported
1079          * set up when the websocket server initializes
1080          */
1081
1082         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
1083
1084         return n;
1085 }