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