lib/client.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2014 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 int
  25 lws_handshake_client(struct lws *wsi, unsigned char **buf, size_t len)
  26 {
  27         int m;
  28
  29         switch (wsi->mode) {
  30         case LWSCM_WSCL_WAITING_PROXY_REPLY:
  31         case LWSCM_WSCL_ISSUE_HANDSHAKE:
  32         case LWSCM_WSCL_WAITING_SERVER_REPLY:
  33         case LWSCM_WSCL_WAITING_EXTENSION_CONNECT:
  34         case LWSCM_WS_CLIENT:
  35                 while (len) {
  36                         /*
  37                          * we were accepting input but now we stopped doing so
  38                          */
  39                         if (!(wsi->rxflow_change_to & LWS_RXFLOW_ALLOW)) {
  40                                 lwsl_debug("%s: caching %d\n", __func__, len);
  41                                 lws_rxflow_cache(wsi, *buf, 0, len);
  42                                 return 0;
  43                         }
  44                         if (wsi->u.ws.rx_draining_ext) {
  45                                 m = lws_rx_sm(wsi, 0);
  46                                 if (m < 0)
  47                                         return -1;
  48                                 continue;
  49                         }
  50                         /* account for what we're using in rxflow buffer */
  51                         if (wsi->rxflow_buffer)
  52                                 wsi->rxflow_pos++;
  53
  54                         if (lws_client_rx_sm(wsi, *(*buf)++)) {
  55                                 lwsl_debug("client_rx_sm exited\n");
  56                                 return -1;
  57                         }
  58                         len--;
  59                 }
  60                 lwsl_debug("%s: finished with %d\n", __func__, len);
  61                 return 0;
  62         default:
  63                 break;
  64         }
  65
  66         return 0;
  67 }
  68
  69 int
  70 lws_client_socket_service(struct lws_context *context, struct lws *wsi,
  71                           struct lws_pollfd *pollfd)
  72 {
  73         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
  74         char *p = (char *)&pt->serv_buf[0];
  75         char *sb = p;
  76         unsigned char c;
  77         int n, len;
  78
  79         switch (wsi->mode) {
  80
  81         case LWSCM_WSCL_WAITING_CONNECT:
  82
  83                 /*
  84                  * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
  85                  * timeout protection set in client-handshake.c
  86                  */
  87
  88                 if (!lws_client_connect_2(wsi)) {
  89                         /* closed */
  90                         lwsl_client("closed\n");
  91                         return -1;
  92                 }
  93
  94                 /* either still pending connection, or changed mode */
  95                 return 0;
  96
  97         case LWSCM_WSCL_WAITING_PROXY_REPLY:
  98
  99                 /* handle proxy hung up on us */
 100
 101                 if (pollfd->revents & LWS_POLLHUP) {
 102
 103                         lwsl_warn("Proxy connection %p (fd=%d) dead\n",
 104                                   (void *)wsi, pollfd->fd);
 105
 106                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 107                         return 0;
 108                 }
 109
 110                 n = recv(wsi->sock, sb, context->pt_serv_buf_size, 0);
 111                 if (n < 0) {
 112                         if (LWS_ERRNO == LWS_EAGAIN) {
 113                                 lwsl_debug("Proxy read returned EAGAIN... retrying\n");
 114                                 return 0;
 115                         }
 116
 117                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 118                         lwsl_err("ERROR reading from proxy socket\n");
 119                         return 0;
 120                 }
 121
 122                 pt->serv_buf[13] = '\0';
 123                 if (strcmp(sb, "HTTP/1.0 200 ") &&
 124                     strcmp(sb, "HTTP/1.1 200 ")) {
 125                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 126                         lwsl_err("ERROR proxy: %s\n", sb);
 127                         return 0;
 128                 }
 129
 130                 /* clear his proxy connection timeout */
 131
 132                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 133
 134                 /* fallthru */
 135
 136         case LWSCM_WSCL_ISSUE_HANDSHAKE:
 137
 138                 /*
 139                  * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
 140                  * timeout protection set in client-handshake.c
 141                  *
 142                  * take care of our lws_callback_on_writable
 143                  * happening at a time when there's no real connection yet
 144                  */
 145                 if (lws_change_pollfd(wsi, LWS_POLLOUT, 0))
 146                         return -1;
 147
 148 #ifdef LWS_OPENSSL_SUPPORT
 149                 /* we can retry this... just cook the SSL BIO the first time */
 150
 151                 if (wsi->use_ssl && !wsi->ssl)
 152                         lws_ssl_client_bio_create(wsi);
 153
 154                 if (wsi->use_ssl) {
 155                         n = lws_ssl_client_connect1(wsi);
 156                         if (!n)
 157                                 return 0;
 158                         if (n < 0)
 159                                 goto bail3;
 160                 } else
 161                         wsi->ssl = NULL;
 162
 163                 /* fallthru */
 164
 165         case LWSCM_WSCL_WAITING_SSL:
 166
 167                 if (wsi->use_ssl) {
 168                         n = lws_ssl_client_connect2(wsi);
 169                         if (!n)
 170                                 return 0;
 171                         if (n < 0)
 172                                 goto bail3;
 173                 } else
 174                         wsi->ssl = NULL;
 175 #endif
 176
 177                 wsi->mode = LWSCM_WSCL_ISSUE_HANDSHAKE2;
 178                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_CLIENT_HS_SEND,
 179                                 context->timeout_secs);
 180
 181                 /* fallthru */
 182
 183         case LWSCM_WSCL_ISSUE_HANDSHAKE2:
 184                 p = lws_generate_client_handshake(wsi, p);
 185                 if (p == NULL) {
 186                         lwsl_err("Failed to generate handshake for client\n");
 187                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 188                         return 0;
 189                 }
 190
 191                 /* send our request to the server */
 192
 193                 lws_latency_pre(context, wsi);
 194
 195                 n = lws_ssl_capable_write(wsi, (unsigned char *)sb, p - sb);
 196                 lws_latency(context, wsi, "send lws_issue_raw", n,
 197                             n == p - sb);
 198                 switch (n) {
 199                 case LWS_SSL_CAPABLE_ERROR:
 200                         lwsl_debug("ERROR writing to client socket\n");
 201                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 202                         return 0;
 203                 case LWS_SSL_CAPABLE_MORE_SERVICE:
 204                         lws_callback_on_writable(wsi);
 205                         break;
 206                 }
 207
 208                 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 209                 wsi->u.hdr.lextable_pos = 0;
 210                 wsi->mode = LWSCM_WSCL_WAITING_SERVER_REPLY;
 211                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE,
 212                                 context->timeout_secs);
 213                 break;
 214
 215         case LWSCM_WSCL_WAITING_SERVER_REPLY:
 216
 217                 /* handle server hung up on us */
 218
 219                 if (pollfd->revents & LWS_POLLHUP) {
 220
 221                         lwsl_debug("Server connection %p (fd=%d) dead\n",
 222                                 (void *)wsi, pollfd->fd);
 223
 224                         goto bail3;
 225                 }
 226
 227                 if (!(pollfd->revents & LWS_POLLIN))
 228                         break;
 229
 230                 /* interpret the server response */
 231
 232                 /*
 233                  *  HTTP/1.1 101 Switching Protocols
 234                  *  Upgrade: websocket
 235                  *  Connection: Upgrade
 236                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 237                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 238                  *  Sec-WebSocket-Protocol: chat
 239                  */
 240
 241                 /*
 242                  * we have to take some care here to only take from the
 243                  * socket bytewise.  The browser may (and has been seen to
 244                  * in the case that onopen() performs websocket traffic)
 245                  * coalesce both handshake response and websocket traffic
 246                  * in one packet, since at that point the connection is
 247                  * definitively ready from browser pov.
 248                  */
 249                 len = 1;
 250                 while (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE &&
 251                        len > 0) {
 252                         n = lws_ssl_capable_read(wsi, &c, 1);
 253                         lws_latency(context, wsi, "send lws_issue_raw", n,
 254                                     n == 1);
 255                         switch (n) {
 256                         case 0:
 257                         case LWS_SSL_CAPABLE_ERROR:
 258                                 goto bail3;
 259                         case LWS_SSL_CAPABLE_MORE_SERVICE:
 260                                 return 0;
 261                         }
 262
 263                         if (lws_parse(wsi, c)) {
 264                                 lwsl_warn("problems parsing header\n");
 265                                 goto bail3;
 266                         }
 267                 }
 268
 269                 /*
 270                  * hs may also be coming in multiple packets, there is a 5-sec
 271                  * libwebsocket timeout still active here too, so if parsing did
 272                  * not complete just wait for next packet coming in this state
 273                  */
 274
 275                 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
 276                         break;
 277
 278                 /*
 279                  * otherwise deal with the handshake.  If there's any
 280                  * packet traffic already arrived we'll trigger poll() again
 281                  * right away and deal with it that way
 282                  */
 283
 284                 return lws_client_interpret_server_handshake(wsi);
 285
 286 bail3:
 287                 lwsl_info("closing conn at LWS_CONNMODE...SERVER_REPLY\n");
 288                 wsi->vhost->protocols[0].callback(wsi,
 289                         LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 290                                         wsi->user_space, NULL, 0);
 291                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 292                 return -1;
 293
 294         case LWSCM_WSCL_WAITING_EXTENSION_CONNECT:
 295                 lwsl_ext("LWSCM_WSCL_WAITING_EXTENSION_CONNECT\n");
 296                 break;
 297
 298         case LWSCM_WSCL_PENDING_CANDIDATE_CHILD:
 299                 lwsl_ext("LWSCM_WSCL_PENDING_CANDIDATE_CHILD\n");
 300                 break;
 301         default:
 302                 break;
 303         }
 304
 305         return 0;
 306 }
 307
 308 /*
 309  * In-place str to lower case
 310  */
 311
 312 static void
 313 strtolower(char *s)
 314 {
 315         while (*s) {
 316                 *s = tolower((int)*s);
 317                 s++;
 318         }
 319 }
 320
 321 int LWS_WARN_UNUSED_RESULT
 322 lws_http_transaction_completed_client(struct lws *wsi)
 323 {
 324         lwsl_debug("%s: wsi %p\n", __func__, wsi);
 325         /* if we can't go back to accept new headers, drop the connection */
 326         if (wsi->u.http.connection_type != HTTP_CONNECTION_KEEP_ALIVE) {
 327                 lwsl_info("%s: %p: close connection\n", __func__, wsi);
 328                 return 1;
 329         }
 330
 331         /* otherwise set ourselves up ready to go again */
 332         wsi->state = LWSS_CLIENT_HTTP_ESTABLISHED;
 333         wsi->mode = LWSCM_HTTP_CLIENT_ACCEPTED;
 334         wsi->u.http.content_length = 0;
 335         wsi->hdr_parsing_completed = 0;
 336
 337         /* He asked for it to stay alive indefinitely */
 338         lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 339
 340         /*
 341          * As client, nothing new is going to come until we ask for it
 342          * we can drop the ah, if any
 343          */
 344         if (wsi->u.hdr.ah) {
 345                 wsi->u.hdr.ah->rxpos = wsi->u.hdr.ah->rxlen;
 346                 lws_header_table_detach(wsi, 0);
 347         }
 348
 349         /* If we're (re)starting on headers, need other implied init */
 350         wsi->u.hdr.ues = URIES_IDLE;
 351
 352         lwsl_info("%s: %p: keep-alive await new transaction\n", __func__, wsi);
 353
 354         return 0;
 355 }
 356
 357 int
 358 lws_client_interpret_server_handshake(struct lws *wsi)
 359 {
 360         int n, len, okay = 0, isErrorCodeReceived = 0, port = 0, ssl = 0;
 361         int close_reason = LWS_CLOSE_STATUS_PROTOCOL_ERR;
 362         struct lws_context *context = wsi->context;
 363         const char *pc, *prot, *ads = NULL, *path;
 364         struct allocated_headers *ah;
 365         char *p;
 366 #ifndef LWS_NO_EXTENSIONS
 367         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 368         char *sb = (char *)&pt->serv_buf[0];
 369         const struct lws_ext_options *opts;
 370         const struct lws_extension *ext;
 371         char ext_name[128];
 372         const char *c, *a;
 373         char ignore;
 374         int more = 1;
 375         void *v;
 376 #endif
 377
 378         if (!wsi->do_ws) {
 379                 /* we are being an http client...
 380                  */
 381                 ah = wsi->u.hdr.ah;
 382                 lws_union_transition(wsi, LWSCM_HTTP_CLIENT_ACCEPTED);
 383                 wsi->state = LWSS_CLIENT_HTTP_ESTABLISHED;
 384                 wsi->u.http.ah = ah;
 385         }
 386
 387         /*
 388          * well, what the server sent looked reasonable for syntax.
 389          * Now let's confirm it sent all the necessary headers
 390          *
 391          * http (non-ws) client will expect something like this
 392          *
 393          * HTTP/1.0.200
 394          * server:.libwebsockets
 395          * content-type:.text/html
 396          * content-length:.17703
 397          * set-cookie:.test=LWS_1456736240_336776_COOKIE;Max-Age=360000
 398          *
 399          *
 400          *
 401          */
 402
 403         wsi->u.http.connection_type = HTTP_CONNECTION_KEEP_ALIVE;
 404         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP);
 405         if (wsi->do_ws && !p) {
 406                 lwsl_info("no URI\n");
 407                 goto bail3;
 408         }
 409         if (!p) {
 410                 p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP1_0);
 411                 wsi->u.http.connection_type = HTTP_CONNECTION_CLOSE;
 412         }
 413         if (!p) {
 414                 lwsl_info("no URI\n");
 415                 goto bail3;
 416         }
 417         n = atoi(p);
 418         if (n == 301 || n == 302 || n == 303 || n == 307 || n == 308) {
 419                 p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_LOCATION);
 420                 if (!p)
 421                         goto bail3;
 422
 423                 if (lws_parse_uri(p, &prot, &ads, &port, &path))
 424                         goto bail3;
 425
 426                 if (!strcmp(prot, "wss://") || !strcmp(prot, "https://"))
 427                         ssl = 1;
 428
 429                 if (lws_client_reset(wsi, ssl, ads, port, path, ads)) {
 430                         lwsl_err("Redirect failed\n");
 431                         goto bail3;
 432                 }
 433                 return 0;
 434         }
 435
 436         if (!wsi->do_ws) {
 437                 if (n != 200) {
 438                         lwsl_notice("Connection failed with code %d", n);
 439                         goto bail2;
 440                 }
 441
 442 #ifdef LWS_WITH_HTTP_PROXY
 443                 wsi->perform_rewrite = 0;
 444                 if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE)) {
 445                         if (!strncmp(lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE),
 446                                      "text/html", 9))
 447                                 wsi->perform_rewrite = 1;
 448                 }
 449 #endif
 450
 451                 /* allocate the per-connection user memory (if any) */
 452                 if (lws_ensure_user_space(wsi)) {
 453                         lwsl_err("Problem allocating wsi user mem\n");
 454                         goto bail2;
 455                 }
 456
 457                 /* he may choose to send us stuff in chunked transfer-coding */
 458                 wsi->chunked = 0;
 459                 wsi->chunk_remaining = 0; /* ie, next thing is chunk size */
 460                 if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_TRANSFER_ENCODING)) {
 461                         wsi->chunked = !strcmp(lws_hdr_simple_ptr(wsi,
 462                                                WSI_TOKEN_HTTP_TRANSFER_ENCODING),
 463                                         "chunked");
 464                         /* first thing is hex, after payload there is crlf */
 465                         wsi->chunk_parser = ELCP_HEX;
 466                 }
 467
 468                 if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_CONTENT_LENGTH)) {
 469                         wsi->u.http.content_length =
 470                                         atoi(lws_hdr_simple_ptr(wsi,
 471                                                 WSI_TOKEN_HTTP_CONTENT_LENGTH));
 472                         lwsl_notice("%s: incoming content length %d\n", __func__,
 473                                         wsi->u.http.content_length);
 474                         wsi->u.http.content_remain = wsi->u.http.content_length;
 475                 } else /* can't do 1.1 without a content length or chunked */
 476                         if (!wsi->chunked)
 477                                 wsi->u.http.connection_type = HTTP_CONNECTION_CLOSE;
 478
 479                 /*
 480                  * we seem to be good to go, give client last chance to check
 481                  * headers and OK it
 482                  */
 483                 if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH,
 484                                             wsi->user_space, NULL, 0))
 485                         goto bail2;
 486
 487                 /* clear his proxy connection timeout */
 488                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 489
 490                 wsi->rxflow_change_to = LWS_RXFLOW_ALLOW;
 491
 492                 /* call him back to inform him he is up */
 493                 if (wsi->protocol->callback(wsi,
 494                                             LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP,
 495                                             wsi->user_space, NULL, 0))
 496                         goto bail3;
 497
 498                 /* free up his parsing allocations */
 499                 lws_header_table_detach(wsi, 0);
 500
 501                 lwsl_notice("%s: client connection up\n", __func__);
 502
 503                 return 0;
 504         }
 505
 506         if (lws_hdr_total_length(wsi, WSI_TOKEN_ACCEPT) == 0) {
 507                 lwsl_info("no ACCEPT\n");
 508                 isErrorCodeReceived = 1;
 509                 goto bail3;
 510         }
 511
 512         if (p && strncmp(p, "101", 3)) {
 513                 lwsl_warn(
 514                        "lws_client_handshake: got bad HTTP response '%s'\n", p);
 515                 goto bail3;
 516         }
 517
 518         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_UPGRADE);
 519         if (!p) {
 520                 lwsl_info("no UPGRADE\n");
 521                 goto bail3;
 522         }
 523         strtolower(p);
 524         if (strcmp(p, "websocket")) {
 525                 lwsl_warn(
 526                       "lws_client_handshake: got bad Upgrade header '%s'\n", p);
 527                 goto bail3;
 528         }
 529
 530         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_CONNECTION);
 531         if (!p) {
 532                 lwsl_info("no Connection hdr\n");
 533                 goto bail3;
 534         }
 535         strtolower(p);
 536         if (strcmp(p, "upgrade")) {
 537                 lwsl_warn("lws_client_int_s_hs: bad header %s\n", p);
 538                 goto bail3;
 539         }
 540
 541         pc = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS);
 542         if (!pc) {
 543                 lwsl_parser("lws_client_int_s_hs: no protocol list\n");
 544         } else
 545                 lwsl_parser("lws_client_int_s_hs: protocol list '%s'\n", pc);
 546
 547         /*
 548          * confirm the protocol the server wants to talk was in the list
 549          * of protocols we offered
 550          */
 551
 552         len = lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL);
 553         if (!len) {
 554                 lwsl_info("lws_client_int_s_hs: WSI_TOKEN_PROTOCOL is null\n");
 555                 /*
 556                  * no protocol name to work from,
 557                  * default to first protocol
 558                  */
 559                 wsi->protocol = &wsi->vhost->protocols[0];
 560                 goto check_extensions;
 561         }
 562
 563         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL);
 564         len = strlen(p);
 565
 566         while (pc && *pc && !okay) {
 567                 if (!strncmp(pc, p, len) &&
 568                     (pc[len] == ',' || pc[len] == '\0')) {
 569                         okay = 1;
 570                         continue;
 571                 }
 572                 while (*pc && *pc++ != ',')
 573                         ;
 574                 while (*pc && *pc == ' ')
 575                         pc++;
 576         }
 577
 578         if (!okay) {
 579                 lwsl_err("lws_client_int_s_hs: got bad protocol %s\n", p);
 580                 goto bail2;
 581         }
 582
 583         /*
 584          * identify the selected protocol struct and set it
 585          */
 586         n = 0;
 587         wsi->protocol = NULL;
 588         while (wsi->vhost->protocols[n].callback && !wsi->protocol) {
 589                 if (strcmp(p, wsi->vhost->protocols[n].name) == 0) {
 590                         wsi->protocol = &wsi->vhost->protocols[n];
 591                         break;
 592                 }
 593                 n++;
 594         }
 595
 596         if (wsi->protocol == NULL) {
 597                 lwsl_err("lws_client_int_s_hs: fail protocol %s\n", p);
 598                 goto bail2;
 599         }
 600
 601
 602 check_extensions:
 603 #ifndef LWS_NO_EXTENSIONS
 604         /* instantiate the accepted extensions */
 605
 606         if (!lws_hdr_total_length(wsi, WSI_TOKEN_EXTENSIONS)) {
 607                 lwsl_ext("no client extensions allowed by server\n");
 608                 goto check_accept;
 609         }
 610
 611         /*
 612          * break down the list of server accepted extensions
 613          * and go through matching them or identifying bogons
 614          */
 615
 616         if (lws_hdr_copy(wsi, sb, context->pt_serv_buf_size, WSI_TOKEN_EXTENSIONS) < 0) {
 617                 lwsl_warn("ext list from server failed to copy\n");
 618                 goto bail2;
 619         }
 620
 621         c = sb;
 622         n = 0;
 623         ignore = 0;
 624         a = NULL;
 625         while (more) {
 626
 627                 if (*c && (*c != ',' && *c != '\t')) {
 628                         if (*c == ';') {
 629                                 ignore = 1;
 630                                 if (!a)
 631                                         a = c + 1;
 632                         }
 633                         if (ignore || *c == ' ') {
 634                                 c++;
 635                                 continue;
 636                         }
 637
 638                         ext_name[n] = *c++;
 639                         if (n < sizeof(ext_name) - 1)
 640                                 n++;
 641                         continue;
 642                 }
 643                 ext_name[n] = '\0';
 644                 ignore = 0;
 645                 if (!*c)
 646                         more = 0;
 647                 else {
 648                         c++;
 649                         if (!n)
 650                                 continue;
 651                 }
 652
 653                 /* check we actually support it */
 654
 655                 lwsl_notice("checking client ext %s\n", ext_name);
 656
 657                 n = 0;
 658                 ext = wsi->vhost->extensions;
 659                 while (ext && ext->callback) {
 660                         if (strcmp(ext_name, ext->name)) {
 661                                 ext++;
 662                                 continue;
 663                         }
 664
 665                         n = 1;
 666                         lwsl_notice("instantiating client ext %s\n", ext_name);
 667
 668                         /* instantiate the extension on this conn */
 669
 670                         wsi->active_extensions[wsi->count_act_ext] = ext;
 671
 672                         /* allow him to construct his ext instance */
 673
 674                         if (ext->callback(lws_get_context(wsi), ext, wsi,
 675                                       LWS_EXT_CB_CLIENT_CONSTRUCT,
 676                                       (void *)&wsi->act_ext_user[wsi->count_act_ext],
 677                                       (void *)&opts, 0)) {
 678                                 lwsl_notice(" ext %s failed construction\n", ext_name);
 679                                 ext++;
 680                                 continue;
 681                         }
 682
 683                         /*
 684                          * allow the user code to override ext defaults if it
 685                          * wants to
 686                          */
 687                         ext_name[0] = '\0';
 688                         if (user_callback_handle_rxflow(wsi->protocol->callback,
 689                                         wsi, LWS_CALLBACK_WS_EXT_DEFAULTS,
 690                                         (char *)ext->name, ext_name,
 691                                         sizeof(ext_name)))
 692                                 goto bail2;
 693
 694                         if (ext_name[0] &&
 695                             lws_ext_parse_options(ext, wsi, wsi->act_ext_user[
 696                                                   wsi->count_act_ext], opts, ext_name,
 697                                                   strlen(ext_name))) {
 698                                 lwsl_err("%s: unable to parse user defaults '%s'",
 699                                          __func__, ext_name);
 700                                 goto bail2;
 701                         }
 702
 703                         /*
 704                          * give the extension the server options
 705                          */
 706                         if (a && lws_ext_parse_options(ext, wsi,
 707                                         wsi->act_ext_user[wsi->count_act_ext],
 708                                         opts, a, c - a)) {
 709                                 lwsl_err("%s: unable to parse remote def '%s'",
 710                                          __func__, a);
 711                                 goto bail2;
 712                         }
 713
 714                         if (ext->callback(lws_get_context(wsi), ext, wsi,
 715                                         LWS_EXT_CB_OPTION_CONFIRM,
 716                                       wsi->act_ext_user[wsi->count_act_ext],
 717                                       NULL, 0)) {
 718                                 lwsl_err("%s: ext %s rejects server options %s",
 719                                          ext->name, a);
 720                                 goto bail2;
 721                         }
 722
 723                         wsi->count_act_ext++;
 724
 725                         ext++;
 726                 }
 727
 728                 if (n == 0) {
 729                         lwsl_warn("Unknown ext '%s'!\n", ext_name);
 730                         goto bail2;
 731                 }
 732
 733                 a = NULL;
 734                 n = 0;
 735         }
 736
 737 check_accept:
 738 #endif
 739
 740         /*
 741          * Confirm his accept token is the one we precomputed
 742          */
 743
 744         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_ACCEPT);
 745         if (strcmp(p, wsi->u.hdr.ah->initial_handshake_hash_base64)) {
 746                 lwsl_warn("lws_client_int_s_hs: accept '%s' wrong vs '%s'\n", p,
 747                                   wsi->u.hdr.ah->initial_handshake_hash_base64);
 748                 goto bail2;
 749         }
 750
 751         /* allocate the per-connection user memory (if any) */
 752         if (lws_ensure_user_space(wsi)) {
 753                 lwsl_err("Problem allocating wsi user mem\n");
 754                 goto bail2;
 755         }
 756
 757         /*
 758          * we seem to be good to go, give client last chance to check
 759          * headers and OK it
 760          */
 761         if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH,
 762                                     wsi->user_space, NULL, 0))
 763                 goto bail2;
 764
 765         /* clear his proxy connection timeout */
 766         lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 767
 768         /* free up his parsing allocations */
 769         lws_header_table_detach(wsi, 0);
 770
 771         lws_union_transition(wsi, LWSCM_WS_CLIENT);
 772         wsi->state = LWSS_ESTABLISHED;
 773
 774         wsi->rxflow_change_to = LWS_RXFLOW_ALLOW;
 775
 776         /*
 777          * create the frame buffer for this connection according to the
 778          * size mentioned in the protocol definition.  If 0 there, then
 779          * use a big default for compatibility
 780          */
 781         n = wsi->protocol->rx_buffer_size;
 782         if (!n)
 783                 n = context->pt_serv_buf_size;
 784         n += LWS_PRE;
 785         wsi->u.ws.rx_ubuf = lws_malloc(n + 4 /* 0x0000ffff zlib */);
 786         if (!wsi->u.ws.rx_ubuf) {
 787                 lwsl_err("Out of Mem allocating rx buffer %d\n", n);
 788                 goto bail2;
 789         }
 790        wsi->u.ws.rx_ubuf_alloc = n;
 791         lwsl_info("Allocating client RX buffer %d\n", n);
 792
 793         if (setsockopt(wsi->sock, SOL_SOCKET, SO_SNDBUF, (const char *)&n,
 794                        sizeof n)) {
 795                 lwsl_warn("Failed to set SNDBUF to %d", n);
 796                 goto bail3;
 797         }
 798
 799         lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
 800
 801         /* call him back to inform him he is up */
 802
 803         if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_ESTABLISHED,
 804                                     wsi->user_space, NULL, 0))
 805                 goto bail3;
 806 #ifndef LWS_NO_EXTENSIONS
 807         /*
 808          * inform all extensions, not just active ones since they
 809          * already know
 810          */
 811         ext = wsi->vhost->extensions;
 812
 813         while (ext && ext->callback) {
 814                 v = NULL;
 815                 for (n = 0; n < wsi->count_act_ext; n++)
 816                         if (wsi->active_extensions[n] == ext)
 817                                 v = wsi->act_ext_user[n];
 818
 819                 ext->callback(context, ext, wsi,
 820                           LWS_EXT_CB_ANY_WSI_ESTABLISHED, v, NULL, 0);
 821                 ext++;
 822         }
 823 #endif
 824
 825         return 0;
 826
 827 bail3:
 828         close_reason = LWS_CLOSE_STATUS_NOSTATUS;
 829
 830 bail2:
 831         if (wsi->protocol && wsi->state == LWSS_ESTABLISHED) {
 832                 if (isErrorCodeReceived && p) {
 833                         wsi->protocol->callback(wsi,
 834                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 835                                                 wsi->user_space, p,
 836                                                 (unsigned int)strlen(p));
 837                 } else {
 838                         wsi->protocol->callback(wsi,
 839                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 840                                                 wsi->user_space, NULL, 0);
 841                 }
 842         }
 843
 844         lwsl_info("closing connection due to bail2 connection error\n");
 845
 846         /* closing will free up his parsing allocations */
 847         lws_close_free_wsi(wsi, close_reason);
 848
 849         return 1;
 850 }
 851
 852
 853 char *
 854 lws_generate_client_handshake(struct lws *wsi, char *pkt)
 855 {
 856         char buf[128], hash[20], key_b64[40], *p = pkt;
 857         struct lws_context *context = wsi->context;
 858         const char *meth;
 859         int n;
 860 #ifndef LWS_NO_EXTENSIONS
 861         const struct lws_extension *ext;
 862         int ext_count = 0;
 863 #endif
 864
 865         meth = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_METHOD);
 866         if (!meth) {
 867                 meth = "GET";
 868                 wsi->do_ws = 1;
 869         } else
 870                 wsi->do_ws = 0;
 871
 872         if (wsi->do_ws) {
 873                 /*
 874                  * create the random key
 875                  */
 876                 n = lws_get_random(context, hash, 16);
 877                 if (n != 16) {
 878                         lwsl_err("Unable to read from random dev %s\n",
 879                                  SYSTEM_RANDOM_FILEPATH);
 880                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 881                         return NULL;
 882                 }
 883
 884                 lws_b64_encode_string(hash, 16, key_b64, sizeof(key_b64));
 885         }
 886
 887         /*
 888          * 04 example client handshake
 889          *
 890          * GET /chat HTTP/1.1
 891          * Host: server.example.com
 892          * Upgrade: websocket
 893          * Connection: Upgrade
 894          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 895          * Sec-WebSocket-Origin: http://example.com
 896          * Sec-WebSocket-Protocol: chat, superchat
 897          * Sec-WebSocket-Version: 4
 898          */
 899
 900         p += sprintf(p, "%s %s HTTP/1.1\x0d\x0a", meth,
 901                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_URI));
 902
 903         p += sprintf(p, "Pragma: no-cache\x0d\x0a"
 904                         "Cache-Control: no-cache\x0d\x0a");
 905
 906         p += sprintf(p, "Host: %s\x0d\x0a",
 907                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_HOST));
 908
 909         if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN))
 910                 p += sprintf(p, "Origin: http://%s\x0d\x0a",
 911                              lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN));
 912
 913         if (wsi->do_ws) {
 914                 p += sprintf(p, "Upgrade: websocket\x0d\x0a"
 915                                 "Connection: Upgrade\x0d\x0a"
 916                                 "Sec-WebSocket-Key: ");
 917                 strcpy(p, key_b64);
 918                 p += strlen(key_b64);
 919                 p += sprintf(p, "\x0d\x0a");
 920                 if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS))
 921                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 922                              lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS));
 923
 924                 /* tell the server what extensions we could support */
 925
 926 #ifndef LWS_NO_EXTENSIONS
 927                 ext = wsi->vhost->extensions;
 928                 while (ext && ext->callback) {
 929                         n = lws_ext_cb_all_exts(context, wsi,
 930                                    LWS_EXT_CB_CHECK_OK_TO_PROPOSE_EXTENSION,
 931                                    (char *)ext->name, 0);
 932                         if (n) { /* an extension vetos us */
 933                                 lwsl_ext("ext %s vetoed\n", (char *)ext->name);
 934                                 ext++;
 935                                 continue;
 936                         }
 937                         n = wsi->vhost->protocols[0].callback(wsi,
 938                                 LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
 939                                         wsi->user_space, (char *)ext->name, 0);
 940
 941                         /*
 942                          * zero return from callback means
 943                          * go ahead and allow the extension,
 944                          * it's what we get if the callback is
 945                          * unhandled
 946                          */
 947
 948                         if (n) {
 949                                 ext++;
 950                                 continue;
 951                         }
 952
 953                         /* apply it */
 954
 955                         if (ext_count)
 956                                 *p++ = ',';
 957                         else
 958                                 p += sprintf(p, "Sec-WebSocket-Extensions: ");
 959                         p += sprintf(p, "%s", ext->client_offer);
 960                         ext_count++;
 961
 962                         ext++;
 963                 }
 964                 if (ext_count)
 965                         p += sprintf(p, "\x0d\x0a");
 966 #endif
 967
 968                 if (wsi->ietf_spec_revision)
 969                         p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
 970                                      wsi->ietf_spec_revision);
 971
 972                 /* prepare the expected server accept response */
 973
 974                 key_b64[39] = '\0'; /* enforce composed length below buf sizeof */
 975                 n = sprintf(buf, "%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11", key_b64);
 976
 977                 lws_SHA1((unsigned char *)buf, n, (unsigned char *)hash);
 978
 979                 lws_b64_encode_string(hash, 20,
 980                                       wsi->u.hdr.ah->initial_handshake_hash_base64,
 981                                       sizeof(wsi->u.hdr.ah->initial_handshake_hash_base64));
 982         }
 983
 984         /* give userland a chance to append, eg, cookies */
 985
 986         wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 987                                 wsi->user_space, &p, (pkt + context->pt_serv_buf_size) - p - 12);
 988
 989         p += sprintf(p, "\x0d\x0a");
 990
 991         return p;
 992 }
 993