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         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
  29                                                   LWS_SEND_BUFFER_POST_PADDING];
  30
  31         if ((unsigned long)wsi < LWS_MAX_PROTOCOLS)
  32                 return;
  33
  34         n = wsi->state;
  35
  36         if (n == WSI_STATE_DEAD_SOCKET)
  37                 return;
  38
  39         /*
  40          * signal we are closing, libsocket_write will
  41          * add any necessary version-specific stuff.  If the write fails,
  42          * no worries we are closing anyway.  If we didn't initiate this
  43          * close, then our state has been changed to
  44          * WSI_STATE_RETURNED_CLOSE_ALREADY and we can skip this
  45          */
  46
  47         if (n == WSI_STATE_ESTABLISHED)
  48                 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
  49                                                                LWS_WRITE_CLOSE);
  50
  51         wsi->state = WSI_STATE_DEAD_SOCKET;
  52
  53         if (wsi->protocol->callback && n == WSI_STATE_ESTABLISHED)
  54                 wsi->protocol->callback(wsi, LWS_CALLBACK_CLOSED,
  55                                                       wsi->user_space, NULL, 0);
  56
  57         for (n = 0; n < WSI_TOKEN_COUNT; n++)
  58                 if (wsi->utf8_token[n].token)
  59                         free(wsi->utf8_token[n].token);
  60
  61 /*      fprintf(stderr, "closing fd=%d\n", wsi->sock); */
  62
  63 #ifdef LWS_OPENSSL_SUPPORT
  64         if (wsi->ssl) {
  65                 n = SSL_get_fd(wsi->ssl);
  66                 SSL_shutdown(wsi->ssl);
  67                 close(n);
  68                 SSL_free(wsi->ssl);
  69         } else {
  70 #endif
  71                 shutdown(wsi->sock, SHUT_RDWR);
  72                 close(wsi->sock);
  73 #ifdef LWS_OPENSSL_SUPPORT
  74         }
  75 #endif
  76         if (wsi->user_space)
  77                 free(wsi->user_space);
  78
  79         free(wsi);
  80 }
  81
  82 static int
  83 libwebsocket_poll_connections(struct libwebsocket_context *this)
  84 {
  85         unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
  86                                                   LWS_SEND_BUFFER_POST_PADDING];
  87         int client = this->count_protocols + 1;
  88         struct libwebsocket *wsi;
  89         int n;
  90         size_t len;
  91
  92         /* check for activity on client sockets */
  93
  94         for (; client < this->fds_count; client++) {
  95
  96                 /* handle session socket closed */
  97
  98                 if (this->fds[client].revents & (POLLERR | POLLHUP)) {
  99
 100                         debug("Session Socket %d %p (fd=%d) dead\n",
 101                                 client, (void *)this->wsi[client],
 102                                                           this->fds[client].fd);
 103
 104                         libwebsocket_close_and_free_session(this->wsi[client]);
 105                         goto nuke_this;
 106                 }
 107
 108                 /* the guy requested a callback when it was OK to write */
 109
 110                 if ((unsigned long)this->wsi[client] > LWS_MAX_PROTOCOLS &&
 111                                           this->fds[client].revents & POLLOUT) {
 112
 113                         this->fds[client].events &= ~POLLOUT;
 114
 115                         this->wsi[client]->protocol->callback(this->wsi[client],
 116                                 LWS_CALLBACK_CLIENT_WRITEABLE,
 117                                 this->wsi[client]->user_space,
 118                                 NULL, 0);
 119                 }
 120
 121                 /* any incoming data ready? */
 122
 123                 if (!(this->fds[client].revents & POLLIN))
 124                         continue;
 125
 126                 /* broadcast? */
 127
 128                 if ((unsigned long)this->wsi[client] < LWS_MAX_PROTOCOLS) {
 129
 130                         /* get the issued broadcast payload from the socket */
 131
 132                         len = read(this->fds[client].fd,
 133                                    buf + LWS_SEND_BUFFER_PRE_PADDING,
 134                                    MAX_BROADCAST_PAYLOAD);
 135
 136                         if (len < 0) {
 137                                 fprintf(stderr,
 138                                            "Error reading broadcast payload\n");
 139                                 continue;
 140                         }
 141
 142                         /* broadcast it to all guys with this protocol index */
 143
 144                         for (n = this->count_protocols + 1;
 145                                                      n < this->fds_count; n++) {
 146
 147                                 wsi = this->wsi[n];
 148
 149                                 if ((unsigned long)wsi < LWS_MAX_PROTOCOLS)
 150                                         continue;
 151
 152                                 /*
 153                                  * never broadcast to non-established
 154                                  * connection
 155                                  */
 156
 157                                 if (wsi->state != WSI_STATE_ESTABLISHED)
 158                                         continue;
 159
 160                                 /* only to clients connected to us */
 161
 162                                 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
 163                                         continue;
 164
 165                                 /*
 166                                  * only broadcast to connections using
 167                                  * the requested protocol
 168                                  */
 169
 170                                 if (wsi->protocol->protocol_index !=
 171                                           (int)(unsigned long)this->wsi[client])
 172                                         continue;
 173
 174                                 /* broadcast it to this connection */
 175
 176                                 wsi->protocol->callback(wsi,
 177                                         LWS_CALLBACK_BROADCAST,
 178                                         wsi->user_space,
 179                                         buf + LWS_SEND_BUFFER_PRE_PADDING, len);
 180                         }
 181
 182                         continue;
 183                 }
 184
 185 #ifdef LWS_OPENSSL_SUPPORT
 186                 if (this->wsi[client]->ssl)
 187                         n = SSL_read(this->wsi[client]->ssl, buf, sizeof buf);
 188                 else
 189 #endif
 190                         n = recv(this->fds[client].fd, buf, sizeof buf, 0);
 191
 192                 if (n < 0) {
 193                         fprintf(stderr, "Socket read returned %d\n", n);
 194                         continue;
 195                 }
 196                 if (!n) {
 197                         libwebsocket_close_and_free_session(this->wsi[client]);
 198                         goto nuke_this;
 199                 }
 200
 201                 /* service incoming data */
 202
 203                 n = libwebsocket_read(this->wsi[client], buf, n);
 204                 if (n >= 0)
 205                         continue;
 206                 /*
 207                  * it closed and nuked wsi[client], so remove the
 208                  * socket handle and wsi from our service list
 209                  */
 210 nuke_this:
 211
 212                 debug("nuking wsi %p, fsd_count = %d\n",
 213                                 (void *)this->wsi[client], this->fds_count - 1);
 214
 215                 this->fds_count--;
 216                 for (n = client; n < this->fds_count; n++) {
 217                         this->fds[n] = this->fds[n + 1];
 218                         this->wsi[n] = this->wsi[n + 1];
 219                 }
 220
 221                 return 0;
 222
 223         }
 224
 225         return 0;
 226 }
 227
 228 /**
 229  * libwebsocket_context_destroy() - Destroy the websocket context
 230  * @this:       Websocket context
 231  *
 232  *      This function closes any active connections and then frees the
 233  *      context.  After calling this, any further use of the context is
 234  *      undefined.
 235  */
 236 void
 237 libwebsocket_context_destroy(struct libwebsocket_context *this)
 238 {
 239         int client;
 240
 241         /* close listening skt and per-protocol broadcast sockets */
 242         for (client = this->count_protocols + 1; client < this->fds_count; client++)
 243                 switch (this->wsi[client]->mode) {
 244                 case LWS_CONNMODE_WS_SERVING:
 245                         libwebsocket_close_and_free_session(this->wsi[client]);
 246                         break;
 247                 case LWS_CONNMODE_WS_CLIENT:
 248                         libwebsocket_client_close(this->wsi[client]);
 249                         break;
 250                 }
 251
 252         close(this->fd_random);
 253
 254 #ifdef LWS_OPENSSL_SUPPORT
 255         if (this->ssl_ctx)
 256                 SSL_CTX_free(this->ssl_ctx);
 257         if (this->ssl_client_ctx)
 258                 SSL_CTX_free(this->ssl_client_ctx);
 259 #endif
 260
 261         free(this);
 262 }
 263
 264 /**
 265  * libwebsocket_service() - Service any pending websocket activity
 266  * @this:       Websocket context
 267  * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
 268  *              service otherwise block and service immediately, returning
 269  *              after the timeout if nothing needed service.
 270  *
 271  *      This function deals with any pending websocket traffic, for three
 272  *      kinds of event.  It handles these events on both server and client
 273  *      types of connection the same.
 274  *
 275  *      1) Accept new connections to our context's server
 276  *
 277  *      2) Perform pending broadcast writes initiated from other forked
 278  *         processes (effectively serializing asynchronous broadcasts)
 279  *
 280  *      3) Call the receive callback for incoming frame data received by
 281  *          server or client connections.
 282  *
 283  *      You need to call this service function periodically to all the above
 284  *      functions to happen; if your application is single-threaded you can
 285  *      just call it in your main event loop.
 286  *
 287  *      Alternatively you can fork a new process that asynchronously handles
 288  *      calling this service in a loop.  In that case you are happy if this
 289  *      call blocks your thread until it needs to take care of something and
 290  *      would call it with a large nonzero timeout.  Your loop then takes no
 291  *      CPU while there is nothing happening.
 292  *
 293  *      If you are calling it in a single-threaded app, you don't want it to
 294  *      wait around blocking other things in your loop from happening, so you
 295  *      would call it with a timeout_ms of 0, so it returns immediately if
 296  *      nothing is pending, or as soon as it services whatever was pending.
 297  */
 298
 299
 300 int
 301 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
 302 {
 303         int n;
 304         int client;
 305         unsigned int clilen;
 306         struct sockaddr_in cli_addr;
 307         int fd;
 308
 309         /* stay dead once we are dead */
 310
 311         if (this == NULL)
 312                 return 1;
 313
 314         /* don't check listen socket if we are not listening */
 315
 316         if (this->listen_port)
 317                 n = poll(this->fds, this->fds_count, timeout_ms);
 318         else
 319                 n = poll(&this->fds[1], this->fds_count - 1, timeout_ms);
 320
 321
 322         if (n < 0 || this->fds[0].revents & (POLLERR | POLLHUP)) {
 323                 /*
 324                 fprintf(stderr, "Listen Socket dead\n");
 325                 */
 326                 goto fatal;
 327         }
 328         if (n == 0) /* poll timeout */
 329                 return 0;
 330
 331         /* handle accept on listening socket? */
 332
 333         for (client = 0; client < this->count_protocols + 1; client++) {
 334
 335                 if (!this->fds[client].revents & POLLIN)
 336                         continue;
 337
 338                 /* listen socket got an unencrypted connection... */
 339
 340                 clilen = sizeof(cli_addr);
 341                 fd  = accept(this->fds[client].fd,
 342                              (struct sockaddr *)&cli_addr, &clilen);
 343                 if (fd < 0) {
 344                         fprintf(stderr, "ERROR on accept");
 345                         continue;
 346                 }
 347
 348                 if (this->fds_count >= MAX_CLIENTS) {
 349                         fprintf(stderr, "too busy");
 350                         close(fd);
 351                         continue;
 352                 }
 353
 354                 if (client) {
 355                         /*
 356                          * accepting a connection to broadcast socket
 357                          * set wsi to be protocol index not pointer
 358                          */
 359
 360                         this->wsi[this->fds_count] =
 361                               (struct libwebsocket *)(long)(client - 1);
 362
 363                         goto fill_in_fds;
 364                 }
 365
 366                 /* accepting connection to main listener */
 367
 368                 this->wsi[this->fds_count] =
 369                                     malloc(sizeof(struct libwebsocket));
 370                 if (!this->wsi[this->fds_count]) {
 371                         fprintf(stderr, "Out of memory for new connection\n");
 372                         continue;
 373                 }
 374
 375 #ifdef LWS_OPENSSL_SUPPORT
 376                 this->wsi[this->fds_count]->ssl = NULL;
 377                 this->ssl_ctx = NULL;
 378
 379                 if (this->use_ssl) {
 380
 381                         this->wsi[this->fds_count]->ssl =
 382                                                          SSL_new(this->ssl_ctx);
 383                         if (this->wsi[this->fds_count]->ssl == NULL) {
 384                                 fprintf(stderr, "SSL_new failed: %s\n",
 385                                     ERR_error_string(SSL_get_error(
 386                                     this->wsi[this->fds_count]->ssl, 0),
 387                                                                  NULL));
 388                                 free(this->wsi[this->fds_count]);
 389                                 continue;
 390                         }
 391
 392                         SSL_set_fd(this->wsi[this->fds_count]->ssl, fd);
 393
 394                         n = SSL_accept(this->wsi[this->fds_count]->ssl);
 395                         if (n != 1) {
 396                                 /*
 397                                  * browsers seem to probe with various
 398                                  * ssl params which fail then retry
 399                                  * and succeed
 400                                  */
 401                                 debug("SSL_accept failed skt %u: %s\n",
 402                                       fd,
 403                                       ERR_error_string(SSL_get_error(
 404                                       this->wsi[this->fds_count]->ssl,
 405                                                              n), NULL));
 406                                 SSL_free(
 407                                        this->wsi[this->fds_count]->ssl);
 408                                 free(this->wsi[this->fds_count]);
 409                                 continue;
 410                         }
 411                         debug("accepted new SSL conn  "
 412                               "port %u on fd=%d SSL ver %s\n",
 413                                 ntohs(cli_addr.sin_port), fd,
 414                                   SSL_get_version(this->wsi[
 415                                                 this->fds_count]->ssl));
 416
 417                 } else
 418 #endif
 419                         debug("accepted new conn  port %u on fd=%d\n",
 420                                           ntohs(cli_addr.sin_port), fd);
 421
 422                 /* intialize the instance struct */
 423
 424                 this->wsi[this->fds_count]->sock = fd;
 425                 this->wsi[this->fds_count]->state = WSI_STATE_HTTP;
 426                 this->wsi[this->fds_count]->name_buffer_pos = 0;
 427                 this->wsi[this->fds_count]->mode = LWS_CONNMODE_WS_SERVING;
 428
 429                 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
 430                         this->wsi[this->fds_count]->
 431                                              utf8_token[n].token = NULL;
 432                         this->wsi[this->fds_count]->
 433                                             utf8_token[n].token_len = 0;
 434                 }
 435
 436                 /*
 437                  * these can only be set once the protocol is known
 438                  * we set an unestablished connection's protocol pointer
 439                  * to the start of the supported list, so it can look
 440                  * for matching ones during the handshake
 441                  */
 442                 this->wsi[this->fds_count]->protocol = this->protocols;
 443                 this->wsi[this->fds_count]->user_space = NULL;
 444
 445                 /*
 446                  * Default protocol is 76 / 00
 447                  * After 76, there's a header specified to inform which
 448                  * draft the client wants, when that's seen we modify
 449                  * the individual connection's spec revision accordingly
 450                  */
 451                 this->wsi[this->fds_count]->ietf_spec_revision = 0;
 452
 453 fill_in_fds:
 454
 455                 /*
 456                  * make sure NO events are seen yet on this new socket
 457                  * (otherwise we inherit old fds[client].revents from
 458                  * previous socket there and die mysteriously! )
 459                  */
 460                 this->fds[this->fds_count].revents = 0;
 461
 462                 this->fds[this->fds_count].events = POLLIN;
 463                 this->fds[this->fds_count++].fd = fd;
 464
 465         }
 466
 467         /* service anything incoming on websocket connection */
 468
 469         libwebsocket_poll_connections(this);
 470
 471         /* this round is done */
 472
 473         return 0;
 474
 475 fatal:
 476
 477         /* inform caller we are dead */
 478
 479         return 1;
 480 }
 481
 482 /**
 483  * libwebsocket_callback_on_writable() - Request a callback when this socket
 484  *                                       becomes able to be written to without
 485  *                                       blocking
 486  *
 487  * @wsi:        Websocket connection instance to get callback for
 488  */
 489
 490 int
 491 libwebsocket_callback_on_writable(struct libwebsocket *wsi)
 492 {
 493         struct libwebsocket_context *this = wsi->protocol->owning_server;
 494         int n;
 495
 496         for (n = this->count_protocols + 1; n < this->fds_count; n++)
 497                 if (this->wsi[n] == wsi) {
 498                         this->fds[n].events |= POLLOUT;
 499                         return 0;
 500                 }
 501
 502         fprintf(stderr, "libwebsocket_callback_on_writable "
 503                                                         "didn't find socket\n");
 504         return 1;
 505 }
 506
 507 /**
 508  * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
 509  *                      all connections using the given protocol when it
 510  *                      becomes possible to write to each socket without
 511  *                      blocking in turn.
 512  *
 513  * @protocol:   Protocol whose connections will get callbacks
 514  */
 515
 516 int
 517 libwebsocket_callback_on_writable_all_protocol(
 518                                   const struct libwebsocket_protocols *protocol)
 519 {
 520         struct libwebsocket_context *this = protocol->owning_server;
 521         int n;
 522
 523         for (n = this->count_protocols + 1; n < this->fds_count; n++)
 524                 if ((unsigned long)this->wsi[n] > LWS_MAX_PROTOCOLS)
 525                         if (this->wsi[n]->protocol == protocol)
 526                                 this->fds[n].events |= POLLOUT;
 527
 528         return 0;
 529 }
 530
 531
 532 /**
 533  * libwebsocket_get_socket_fd() - returns the socket file descriptor
 534  *
 535  * You will not need this unless you are doing something special
 536  *
 537  * @wsi:        Websocket connection instance
 538  */
 539
 540 int
 541 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
 542 {
 543         return wsi->sock;
 544 }
 545
 546 /**
 547  * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
 548  *                              receieved packets.
 549  *
 550  * If the output side of a server process becomes choked, this allows flow
 551  * control for the input side.
 552  *
 553  * @wsi:        Websocket connection instance to get callback for
 554  * @enable:     0 = disable read servicing for this connection, 1 = enable
 555  */
 556
 557 int
 558 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
 559 {
 560         struct libwebsocket_context *this = wsi->protocol->owning_server;
 561         int n;
 562
 563         for (n = this->count_protocols + 1; n < this->fds_count; n++)
 564                 if (this->wsi[n] == wsi) {
 565                         if (enable)
 566                                 this->fds[n].events |= POLLIN;
 567                         else
 568                                 this->fds[n].events &= ~POLLIN;
 569
 570                         return 0;
 571                 }
 572
 573         fprintf(stderr, "libwebsocket_callback_on_writable "
 574                                                      "unable to find socket\n");
 575         return 1;
 576 }
 577
 578 /**
 579  * libwebsocket_canonical_hostname() - returns this host's hostname
 580  *
 581  * This is typically used by client code to fill in the host parameter
 582  * when making a client connection.  You can only call it after the context
 583  * has been created.
 584  *
 585  * @this:       Websocket context
 586  */
 587
 588
 589 extern const char *
 590 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
 591 {
 592         return (const char *)this->canonical_hostname;
 593 }
 594
 595
 596 static void sigpipe_handler(int x)
 597 {
 598 }
 599
 600
 601 /**
 602  * libwebsocket_create_context() - Create the websocket handler
 603  * @port:       Port to listen on... you can use 0 to suppress listening on
 604  *              any port, that's what you want if you are not running a
 605  *              websocket server at all but just using it as a client
 606  * @protocols:  Array of structures listing supported protocols and a protocol-
 607  *              specific callback for each one.  The list is ended with an
 608  *              entry that has a NULL callback pointer.
 609  *              It's not const because we write the owning_server member
 610  * @ssl_cert_filepath:  If libwebsockets was compiled to use ssl, and you want
 611  *                      to listen using SSL, set to the filepath to fetch the
 612  *                      server cert from, otherwise NULL for unencrypted
 613  * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
 614  *                      else ignored
 615  * @gid:        group id to change to after setting listen socket, or -1.
 616  * @uid:        user id to change to after setting listen socket, or -1.
 617  * @options:    0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
 618  *
 619  *      This function creates the listening socket and takes care
 620  *      of all initialization in one step.
 621  *
 622  *      After initialization, it returns a struct libwebsocket_context * that
 623  *      represents this server.  After calling, user code needs to take care
 624  *      of calling libwebsocket_service() with the context pointer to get the
 625  *      server's sockets serviced.  This can be done in the same process context
 626  *      or a forked process, or another thread,
 627  *
 628  *      The protocol callback functions are called for a handful of events
 629  *      including http requests coming in, websocket connections becoming
 630  *      established, and data arriving; it's also called periodically to allow
 631  *      async transmission.
 632  *
 633  *      HTTP requests are sent always to the FIRST protocol in @protocol, since
 634  *      at that time websocket protocol has not been negotiated.  Other
 635  *      protocols after the first one never see any HTTP callack activity.
 636  *
 637  *      The server created is a simple http server by default; part of the
 638  *      websocket standard is upgrading this http connection to a websocket one.
 639  *
 640  *      This allows the same server to provide files like scripts and favicon /
 641  *      images or whatever over http and dynamic data over websockets all in
 642  *      one place; they're all handled in the user callback.
 643  */
 644
 645 struct libwebsocket_context *
 646 libwebsocket_create_context(int port,
 647                                struct libwebsocket_protocols *protocols,
 648                                const char *ssl_cert_filepath,
 649                                const char *ssl_private_key_filepath,
 650                                int gid, int uid, unsigned int options)
 651 {
 652         int n;
 653         int sockfd = 0;
 654         int fd;
 655         struct sockaddr_in serv_addr, cli_addr;
 656         int opt = 1;
 657         struct libwebsocket_context *this = NULL;
 658         unsigned int slen;
 659         char *p;
 660         char hostname[1024];
 661         struct hostent *he;
 662
 663 #ifdef LWS_OPENSSL_SUPPORT
 664         SSL_METHOD *method;
 665         char ssl_err_buf[512];
 666 #endif
 667
 668         this = malloc(sizeof(struct libwebsocket_context));
 669         if (!this) {
 670                 fprintf(stderr, "No memory for websocket context\n");
 671                 return NULL;
 672         }
 673         this->protocols = protocols;
 674         this->listen_port = port;
 675         this->http_proxy_port = 0;
 676         this->http_proxy_address[0] = '\0';
 677         this->options = options;
 678
 679         this->fd_random = open(SYSTEM_RANDOM_FILEPATH, O_RDONLY);
 680         if (this->fd_random < 0) {
 681                 fprintf(stderr, "Unable to open random device %s %d\n",
 682                                        SYSTEM_RANDOM_FILEPATH, this->fd_random);
 683                 return NULL;
 684         }
 685
 686         /* find canonical hostname */
 687
 688         hostname[(sizeof hostname) - 1] = '\0';
 689         gethostname(hostname, (sizeof hostname) - 1);
 690         he = gethostbyname(hostname);
 691         strncpy(this->canonical_hostname, he->h_name,
 692                                            sizeof this->canonical_hostname - 1);
 693         this->canonical_hostname[sizeof this->canonical_hostname - 1] = '\0';
 694         fprintf(stderr, "  canonical hostname = '%s'\n",
 695                                         this->canonical_hostname);
 696
 697         /* split the proxy ads:port if given */
 698
 699         p = getenv("http_proxy");
 700         if (p) {
 701                 strncpy(this->http_proxy_address, p,
 702                                            sizeof this->http_proxy_address - 1);
 703                 this->http_proxy_address[
 704                                     sizeof this->http_proxy_address - 1] = '\0';
 705
 706                 p = strchr(this->http_proxy_address, ':');
 707                 if (p == NULL) {
 708                         fprintf(stderr, "http_proxy needs to be ads:port\n");
 709                         return NULL;
 710                 }
 711                 *p = '\0';
 712                 this->http_proxy_port = atoi(p + 1);
 713
 714                 fprintf(stderr, "Using proxy %s:%u\n",
 715                                 this->http_proxy_address,
 716                                                         this->http_proxy_port);
 717         }
 718
 719         if (port) {
 720
 721 #ifdef LWS_OPENSSL_SUPPORT
 722                 this->use_ssl = ssl_cert_filepath != NULL &&
 723                                                ssl_private_key_filepath != NULL;
 724                 if (this->use_ssl)
 725                         fprintf(stderr, " Compiled with SSL support, "
 726                                                                   "using it\n");
 727                 else
 728                         fprintf(stderr, " Compiled with SSL support, "
 729                                                               "not using it\n");
 730
 731 #else
 732                 if (ssl_cert_filepath != NULL &&
 733                                              ssl_private_key_filepath != NULL) {
 734                         fprintf(stderr, " Not compiled for OpenSSl support!\n");
 735                         return NULL;
 736                 }
 737                 fprintf(stderr, " Compiled without SSL support, "
 738                                                        "serving unencrypted\n");
 739 #endif
 740         }
 741
 742         /* ignore SIGPIPE */
 743
 744         signal(SIGPIPE, sigpipe_handler);
 745
 746
 747 #ifdef LWS_OPENSSL_SUPPORT
 748
 749         /* basic openssl init */
 750
 751         SSL_library_init();
 752
 753         OpenSSL_add_all_algorithms();
 754         SSL_load_error_strings();
 755
 756         /*
 757          * Firefox insists on SSLv23 not SSLv3
 758          * Konq disables SSLv2 by default now, SSLv23 works
 759          */
 760
 761         method = (SSL_METHOD *)SSLv23_server_method();
 762         if (!method) {
 763                 fprintf(stderr, "problem creating ssl method: %s\n",
 764                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 765                 return NULL;
 766         }
 767         this->ssl_ctx = SSL_CTX_new(method);    /* create context */
 768         if (!this->ssl_ctx) {
 769                 fprintf(stderr, "problem creating ssl context: %s\n",
 770                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 771                 return NULL;
 772         }
 773
 774         /* client context */
 775
 776         method = (SSL_METHOD *)SSLv23_client_method();
 777         if (!method) {
 778                 fprintf(stderr, "problem creating ssl method: %s\n",
 779                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 780                 return NULL;
 781         }
 782         this->ssl_client_ctx = SSL_CTX_new(method);     /* create context */
 783         if (!this->ssl_client_ctx) {
 784                 fprintf(stderr, "problem creating ssl context: %s\n",
 785                         ERR_error_string(ERR_get_error(), ssl_err_buf));
 786                 return NULL;
 787         }
 788
 789
 790         /* openssl init for cert verification (used with client sockets) */
 791
 792         if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
 793                                                     LWS_OPENSSL_CLIENT_CERTS)) {
 794                 fprintf(stderr, "Unable to load SSL Client certs from %s "
 795                         "(set by --with-client-cert-dir= in configure) -- "
 796                         " client ssl isn't going to work",
 797                                                       LWS_OPENSSL_CLIENT_CERTS);
 798         }
 799
 800         if (this->use_ssl) {
 801
 802                 /* openssl init for server sockets */
 803
 804                 /* set the local certificate from CertFile */
 805                 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
 806                                         ssl_cert_filepath, SSL_FILETYPE_PEM);
 807                 if (n != 1) {
 808                         fprintf(stderr, "problem getting cert '%s': %s\n",
 809                                 ssl_cert_filepath,
 810                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
 811                         return NULL;
 812                 }
 813                 /* set the private key from KeyFile */
 814                 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
 815                                                 ssl_private_key_filepath,
 816                                                        SSL_FILETYPE_PEM) != 1) {
 817                         fprintf(stderr, "ssl problem getting key '%s': %s\n",
 818                                                 ssl_private_key_filepath,
 819                                 ERR_error_string(ERR_get_error(), ssl_err_buf));
 820                         return NULL;
 821                 }
 822                 /* verify private key */
 823                 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
 824                         fprintf(stderr, "Private SSL key doesn't match cert\n");
 825                         return NULL;
 826                 }
 827
 828                 /* SSL is happy and has a cert it's content with */
 829         }
 830 #endif
 831
 832         /* selftest */
 833
 834         if (lws_b64_selftest())
 835                 return NULL;
 836
 837         /* set up our external listening socket we serve on */
 838
 839         if (port) {
 840
 841                 sockfd = socket(AF_INET, SOCK_STREAM, 0);
 842                 if (sockfd < 0) {
 843                         fprintf(stderr, "ERROR opening socket");
 844                         return NULL;
 845                 }
 846
 847                 /* allow us to restart even if old sockets in TIME_WAIT */
 848                 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 849
 850                 bzero((char *) &serv_addr, sizeof(serv_addr));
 851                 serv_addr.sin_family = AF_INET;
 852                 serv_addr.sin_addr.s_addr = INADDR_ANY;
 853                 serv_addr.sin_port = htons(port);
 854
 855                 n = bind(sockfd, (struct sockaddr *) &serv_addr,
 856                                                              sizeof(serv_addr));
 857                 if (n < 0) {
 858                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
 859                                                                 port, n, errno);
 860                         return NULL;
 861                 }
 862         }
 863
 864         /* drop any root privs for this process */
 865
 866         if (gid != -1)
 867                 if (setgid(gid))
 868                         fprintf(stderr, "setgid: %s\n", strerror(errno));
 869         if (uid != -1)
 870                 if (setuid(uid))
 871                         fprintf(stderr, "setuid: %s\n", strerror(errno));
 872
 873         /*
 874          * prepare the poll() fd array... it's like this
 875          *
 876          * [0] = external listening socket
 877          * [1 .. this->count_protocols] = per-protocol broadcast sockets
 878          * [this->count_protocols + 1 ... this->fds_count-1] = connection skts
 879          */
 880
 881         this->fds_count = 1;
 882         this->fds[0].fd = sockfd;
 883         this->fds[0].events = POLLIN;
 884         this->count_protocols = 0;
 885
 886         if (port) {
 887                 listen(sockfd, 5);
 888                 fprintf(stderr, " Listening on port %d\n", port);
 889         }
 890
 891         /* set up our internal broadcast trigger sockets per-protocol */
 892
 893         for (; protocols[this->count_protocols].callback;
 894                                                       this->count_protocols++) {
 895                 protocols[this->count_protocols].owning_server = this;
 896                 protocols[this->count_protocols].protocol_index =
 897                                                           this->count_protocols;
 898
 899                 fd = socket(AF_INET, SOCK_STREAM, 0);
 900                 if (fd < 0) {
 901                         fprintf(stderr, "ERROR opening socket");
 902                         return NULL;
 903                 }
 904
 905                 /* allow us to restart even if old sockets in TIME_WAIT */
 906                 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 907
 908                 bzero((char *) &serv_addr, sizeof(serv_addr));
 909                 serv_addr.sin_family = AF_INET;
 910                 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 911                 serv_addr.sin_port = 0; /* pick the port for us */
 912
 913                 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
 914                 if (n < 0) {
 915                         fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
 916                                                                 port, n, errno);
 917                         return NULL;
 918                 }
 919
 920                 slen = sizeof cli_addr;
 921                 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
 922                 if (n < 0) {
 923                         fprintf(stderr, "getsockname failed\n");
 924                         return NULL;
 925                 }
 926                 protocols[this->count_protocols].broadcast_socket_port =
 927                                                        ntohs(cli_addr.sin_port);
 928                 listen(fd, 5);
 929
 930                 debug("  Protocol %s broadcast socket %d\n",
 931                                 protocols[this->count_protocols].name,
 932                                                       ntohs(cli_addr.sin_port));
 933
 934                 this->fds[this->fds_count].fd = fd;
 935                 this->fds[this->fds_count].events = POLLIN;
 936                 /* wsi only exists for connections, not broadcast listener */
 937                 this->wsi[this->fds_count] = NULL;
 938                 this->fds_count++;
 939         }
 940
 941         return this;
 942 }
 943
 944
 945 #ifndef LWS_NO_FORK
 946
 947 /**
 948  * libwebsockets_fork_service_loop() - Optional helper function forks off
 949  *                                a process for the websocket server loop.
 950  *                              You don't have to use this but if not, you
 951  *                              have to make sure you are calling
 952  *                              libwebsocket_service periodically to service
 953  *                              the websocket traffic
 954  * @this:       server context returned by creation function
 955  */
 956
 957 int
 958 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
 959 {
 960         int client;
 961         int fd;
 962         struct sockaddr_in cli_addr;
 963         int n;
 964
 965         n = fork();
 966         if (n < 0)
 967                 return n;
 968
 969         if (!n) {
 970
 971                 /* main process context */
 972
 973                 for (client = 1; client < this->count_protocols + 1; client++) {
 974                         fd = socket(AF_INET, SOCK_STREAM, 0);
 975                         if (fd < 0) {
 976                                 fprintf(stderr, "Unable to create socket\n");
 977                                 return -1;
 978                         }
 979                         cli_addr.sin_family = AF_INET;
 980                         cli_addr.sin_port = htons(
 981                              this->protocols[client - 1].broadcast_socket_port);
 982                         cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 983                         n = connect(fd, (struct sockaddr *)&cli_addr,
 984                                                                sizeof cli_addr);
 985                         if (n < 0) {
 986                                 fprintf(stderr, "Unable to connect to "
 987                                                 "broadcast socket %d, %s\n",
 988                                                 client, strerror(errno));
 989                                 return -1;
 990                         }
 991
 992                         this->protocols[client - 1].broadcast_socket_user_fd =
 993                                                                              fd;
 994                 }
 995
 996
 997                 return 0;
 998         }
 999
1000         /* we want a SIGHUP when our parent goes down */
1001         prctl(PR_SET_PDEATHSIG, SIGHUP);
1002
1003         /* in this forked process, sit and service websocket connections */
1004
1005         while (1)
1006                 if (libwebsocket_service(this, 1000))
1007                         return -1;
1008
1009         return 0;
1010 }
1011
1012 #endif
1013
1014 /**
1015  * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1016  *                                connection.
1017  * @wsi:        pointer to struct websocket you want to know the protocol of
1018  *
1019  *
1020  *      This is useful to get the protocol to broadcast back to from inside
1021  * the callback.
1022  */
1023
1024 const struct libwebsocket_protocols *
1025 libwebsockets_get_protocol(struct libwebsocket *wsi)
1026 {
1027         return wsi->protocol;
1028 }
1029
1030 /**
1031  * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1032  *                                connections of the given protocol.
1033  * @protocol:   pointer to the protocol you will broadcast to all members of
1034  * @buf:  buffer containing the data to be broadcase.  NOTE: this has to be
1035  *              allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1036  *              the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1037  *              case you are calling this function from callback context.
1038  * @len:        length of payload data in buf, starting from buf.
1039  *
1040  *      This function allows bulk sending of a packet to every connection using
1041  * the given protocol.  It does not send the data directly; instead it calls
1042  * the callback with a reason type of LWS_CALLBACK_BROADCAST.  If the callback
1043  * wants to actually send the data for that connection, the callback itself
1044  * should call libwebsocket_write().
1045  *
1046  * libwebsockets_broadcast() can be called from another fork context without
1047  * having to take any care about data visibility between the processes, it'll
1048  * "just work".
1049  */
1050
1051
1052 int
1053 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1054                                                  unsigned char *buf, size_t len)
1055 {
1056         struct libwebsocket_context *this = protocol->owning_server;
1057         int n;
1058
1059         if (!protocol->broadcast_socket_user_fd) {
1060                 /*
1061                  * We are either running unforked / flat, or we are being
1062                  * called from poll thread context
1063                  * eg, from a callback.  In that case don't use sockets for
1064                  * broadcast IPC (since we can't open a socket connection to
1065                  * a socket listening on our own thread) but directly do the
1066                  * send action.
1067                  *
1068                  * Locking is not needed because we are by definition being
1069                  * called in the poll thread context and are serialized.
1070                  */
1071
1072                 for (n = this->count_protocols + 1; n < this->fds_count; n++) {
1073
1074                         if ((unsigned long)this->wsi[n] < LWS_MAX_PROTOCOLS)
1075                                 continue;
1076
1077                         /* never broadcast to non-established connection */
1078                         if (this->wsi[n]->state != WSI_STATE_ESTABLISHED)
1079                                 continue;
1080
1081                         /* only broadcast to guys using requested protocol */
1082                         if (this->wsi[n]->protocol != protocol)
1083                                 continue;
1084
1085                         this->wsi[n]->protocol->callback(this->wsi[n],
1086                                          LWS_CALLBACK_BROADCAST,
1087                                          this->wsi[n]->user_space,
1088                                          buf, len);
1089                 }
1090
1091                 return 0;
1092         }
1093
1094         /*
1095          * We're being called from a different process context than the server
1096          * loop.  Instead of broadcasting directly, we send our
1097          * payload on a socket to do the IPC; the server process will serialize
1098          * the broadcast action in its main poll() loop.
1099          *
1100          * There's one broadcast socket listening for each protocol supported
1101          * set up when the websocket server initializes
1102          */
1103
1104         n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);
1105
1106         return n;
1107 }