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