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         const char *cce = NULL;
  76         unsigned char c;
  77         char *sb = p;
  78         int n, len;
  79
  80         switch (wsi->mode) {
  81
  82         case LWSCM_WSCL_WAITING_CONNECT:
  83
  84                 /*
  85                  * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
  86                  * timeout protection set in client-handshake.c
  87                  */
  88
  89                 if (!lws_client_connect_2(wsi)) {
  90                         /* closed */
  91                         lwsl_client("closed\n");
  92                         return -1;
  93                 }
  94
  95                 /* either still pending connection, or changed mode */
  96                 return 0;
  97
  98         case LWSCM_WSCL_WAITING_PROXY_REPLY:
  99
 100                 /* handle proxy hung up on us */
 101
 102                 if (pollfd->revents & LWS_POLLHUP) {
 103
 104                         lwsl_warn("Proxy connection %p (fd=%d) dead\n",
 105                                   (void *)wsi, pollfd->fd);
 106
 107                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 108                         return 0;
 109                 }
 110
 111                 n = recv(wsi->sock, sb, context->pt_serv_buf_size, 0);
 112                 if (n < 0) {
 113                         if (LWS_ERRNO == LWS_EAGAIN) {
 114                                 lwsl_debug("Proxy read returned EAGAIN... retrying\n");
 115                                 return 0;
 116                         }
 117
 118                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 119                         lwsl_err("ERROR reading from proxy socket\n");
 120                         return 0;
 121                 }
 122
 123                 pt->serv_buf[13] = '\0';
 124                 if (strcmp(sb, "HTTP/1.0 200 ") &&
 125                     strcmp(sb, "HTTP/1.1 200 ")) {
 126                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 127                         lwsl_err("ERROR proxy: %s\n", sb);
 128                         return 0;
 129                 }
 130
 131                 /* clear his proxy connection timeout */
 132
 133                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 134
 135                 /* fallthru */
 136
 137         case LWSCM_WSCL_ISSUE_HANDSHAKE:
 138
 139                 /*
 140                  * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
 141                  * timeout protection set in client-handshake.c
 142                  *
 143                  * take care of our lws_callback_on_writable
 144                  * happening at a time when there's no real connection yet
 145                  */
 146                 if (lws_change_pollfd(wsi, LWS_POLLOUT, 0))
 147                         return -1;
 148
 149 #ifdef LWS_OPENSSL_SUPPORT
 150                 /* we can retry this... just cook the SSL BIO the first time */
 151
 152                 if (wsi->use_ssl && !wsi->ssl)
 153                         lws_ssl_client_bio_create(wsi);
 154
 155                 if (wsi->use_ssl) {
 156                         n = lws_ssl_client_connect1(wsi);
 157                         if (!n)
 158                                 return 0;
 159                         if (n < 0) {
 160                                 cce = "lws_ssl_client_connect1 failed";
 161                                 goto bail3;
 162                         }
 163                 } else
 164                         wsi->ssl = NULL;
 165
 166                 /* fallthru */
 167
 168         case LWSCM_WSCL_WAITING_SSL:
 169
 170                 if (wsi->use_ssl) {
 171                         n = lws_ssl_client_connect2(wsi);
 172                         if (!n)
 173                                 return 0;
 174                         if (n < 0) {
 175                                 cce = "lws_ssl_client_connect2 failed";
 176                                 goto bail3;
 177                         }
 178                 } else
 179                         wsi->ssl = NULL;
 180 #endif
 181
 182                 wsi->mode = LWSCM_WSCL_ISSUE_HANDSHAKE2;
 183                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_CLIENT_HS_SEND,
 184                                 context->timeout_secs);
 185
 186                 /* fallthru */
 187
 188         case LWSCM_WSCL_ISSUE_HANDSHAKE2:
 189                 p = lws_generate_client_handshake(wsi, p);
 190                 if (p == NULL) {
 191                         lwsl_err("Failed to generate handshake for client\n");
 192                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 193                         return 0;
 194                 }
 195
 196                 /* send our request to the server */
 197
 198                 lws_latency_pre(context, wsi);
 199
 200                 n = lws_ssl_capable_write(wsi, (unsigned char *)sb, p - sb);
 201                 lws_latency(context, wsi, "send lws_issue_raw", n,
 202                             n == p - sb);
 203                 switch (n) {
 204                 case LWS_SSL_CAPABLE_ERROR:
 205                         lwsl_debug("ERROR writing to client socket\n");
 206                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 207                         return 0;
 208                 case LWS_SSL_CAPABLE_MORE_SERVICE:
 209                         lws_callback_on_writable(wsi);
 210                         break;
 211                 }
 212
 213                 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 214                 wsi->u.hdr.lextable_pos = 0;
 215                 wsi->mode = LWSCM_WSCL_WAITING_SERVER_REPLY;
 216                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE,
 217                                 context->timeout_secs);
 218                 break;
 219
 220         case LWSCM_WSCL_WAITING_SERVER_REPLY:
 221
 222                 /* handle server hung up on us */
 223
 224                 if (pollfd->revents & LWS_POLLHUP) {
 225
 226                         lwsl_debug("Server connection %p (fd=%d) dead\n",
 227                                 (void *)wsi, pollfd->fd);
 228                         cce = "Peer hung up";
 229                         goto bail3;
 230                 }
 231
 232                 if (!(pollfd->revents & LWS_POLLIN))
 233                         break;
 234
 235                 /* interpret the server response */
 236
 237                 /*
 238                  *  HTTP/1.1 101 Switching Protocols
 239                  *  Upgrade: websocket
 240                  *  Connection: Upgrade
 241                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 242                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 243                  *  Sec-WebSocket-Protocol: chat
 244                  */
 245
 246                 /*
 247                  * we have to take some care here to only take from the
 248                  * socket bytewise.  The browser may (and has been seen to
 249                  * in the case that onopen() performs websocket traffic)
 250                  * coalesce both handshake response and websocket traffic
 251                  * in one packet, since at that point the connection is
 252                  * definitively ready from browser pov.
 253                  */
 254                 len = 1;
 255                 while (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE &&
 256                        len > 0) {
 257                         n = lws_ssl_capable_read(wsi, &c, 1);
 258                         lws_latency(context, wsi, "send lws_issue_raw", n,
 259                                     n == 1);
 260                         switch (n) {
 261                         case 0:
 262                         case LWS_SSL_CAPABLE_ERROR:
 263                                 cce = "read failed";
 264                                 goto bail3;
 265                         case LWS_SSL_CAPABLE_MORE_SERVICE:
 266                                 return 0;
 267                         }
 268
 269                         if (lws_parse(wsi, c)) {
 270                                 lwsl_warn("problems parsing header\n");
 271                                 goto bail3;
 272                         }
 273                 }
 274
 275                 /*
 276                  * hs may also be coming in multiple packets, there is a 5-sec
 277                  * libwebsocket timeout still active here too, so if parsing did
 278                  * not complete just wait for next packet coming in this state
 279                  */
 280
 281                 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
 282                         break;
 283
 284                 /*
 285                  * otherwise deal with the handshake.  If there's any
 286                  * packet traffic already arrived we'll trigger poll() again
 287                  * right away and deal with it that way
 288                  */
 289
 290                 return lws_client_interpret_server_handshake(wsi);
 291
 292 bail3:
 293                 lwsl_info("closing conn at LWS_CONNMODE...SERVER_REPLY\n");
 294                 wsi->vhost->protocols[0].callback(wsi,
 295                         LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 296                         wsi->user_space, (void *)cce, cce ? strlen(cce) : 0);
 297                 wsi->already_did_cce = 1;
 298                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 299                 return -1;
 300
 301         case LWSCM_WSCL_WAITING_EXTENSION_CONNECT:
 302                 lwsl_ext("LWSCM_WSCL_WAITING_EXTENSION_CONNECT\n");
 303                 break;
 304
 305         case LWSCM_WSCL_PENDING_CANDIDATE_CHILD:
 306                 lwsl_ext("LWSCM_WSCL_PENDING_CANDIDATE_CHILD\n");
 307                 break;
 308         default:
 309                 break;
 310         }
 311
 312         return 0;
 313 }
 314
 315 /*
 316  * In-place str to lower case
 317  */
 318
 319 static void
 320 strtolower(char *s)
 321 {
 322         while (*s) {
 323                 *s = tolower((int)*s);
 324                 s++;
 325         }
 326 }
 327
 328 int LWS_WARN_UNUSED_RESULT
 329 lws_http_transaction_completed_client(struct lws *wsi)
 330 {
 331         lwsl_debug("%s: wsi %p\n", __func__, wsi);
 332         /* if we can't go back to accept new headers, drop the connection */
 333         if (wsi->u.http.connection_type != HTTP_CONNECTION_KEEP_ALIVE) {
 334                 lwsl_info("%s: %p: close connection\n", __func__, wsi);
 335                 return 1;
 336         }
 337
 338         /* otherwise set ourselves up ready to go again */
 339         wsi->state = LWSS_CLIENT_HTTP_ESTABLISHED;
 340         wsi->mode = LWSCM_HTTP_CLIENT_ACCEPTED;
 341         wsi->u.http.content_length = 0;
 342         wsi->hdr_parsing_completed = 0;
 343
 344         /* He asked for it to stay alive indefinitely */
 345         lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 346
 347         /*
 348          * As client, nothing new is going to come until we ask for it
 349          * we can drop the ah, if any
 350          */
 351         if (wsi->u.hdr.ah) {
 352                 wsi->u.hdr.ah->rxpos = wsi->u.hdr.ah->rxlen;
 353                 lws_header_table_detach(wsi, 0);
 354         }
 355
 356         /* If we're (re)starting on headers, need other implied init */
 357         wsi->u.hdr.ues = URIES_IDLE;
 358
 359         lwsl_info("%s: %p: keep-alive await new transaction\n", __func__, wsi);
 360
 361         return 0;
 362 }
 363
 364 int
 365 lws_client_interpret_server_handshake(struct lws *wsi)
 366 {
 367         int n, len, okay = 0, port = 0, ssl = 0;
 368         int close_reason = LWS_CLOSE_STATUS_PROTOCOL_ERR;
 369         struct lws_context *context = wsi->context;
 370         const char *pc, *prot, *ads = NULL, *path, *cce = NULL;
 371         struct allocated_headers *ah;
 372         char *p;
 373 #ifndef LWS_NO_EXTENSIONS
 374         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 375         char *sb = (char *)&pt->serv_buf[0];
 376         const struct lws_ext_options *opts;
 377         const struct lws_extension *ext;
 378         char ext_name[128];
 379         const char *c, *a;
 380         char ignore;
 381         int more = 1;
 382         void *v;
 383 #endif
 384
 385         if (!wsi->do_ws) {
 386                 /* we are being an http client...
 387                  */
 388                 ah = wsi->u.hdr.ah;
 389                 lws_union_transition(wsi, LWSCM_HTTP_CLIENT_ACCEPTED);
 390                 wsi->state = LWSS_CLIENT_HTTP_ESTABLISHED;
 391                 wsi->u.http.ah = ah;
 392         }
 393
 394         /*
 395          * well, what the server sent looked reasonable for syntax.
 396          * Now let's confirm it sent all the necessary headers
 397          *
 398          * http (non-ws) client will expect something like this
 399          *
 400          * HTTP/1.0.200
 401          * server:.libwebsockets
 402          * content-type:.text/html
 403          * content-length:.17703
 404          * set-cookie:.test=LWS_1456736240_336776_COOKIE;Max-Age=360000
 405          *
 406          *
 407          *
 408          */
 409
 410         wsi->u.http.connection_type = HTTP_CONNECTION_KEEP_ALIVE;
 411         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP);
 412         if (wsi->do_ws && !p) {
 413                 lwsl_info("no URI\n");
 414                 cce = "HS: URI missing";
 415                 goto bail3;
 416         }
 417         if (!p) {
 418                 p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP1_0);
 419                 wsi->u.http.connection_type = HTTP_CONNECTION_CLOSE;
 420         }
 421         if (!p) {
 422                 cce = "HS: URI missing";
 423                 lwsl_info("no URI\n");
 424                 goto bail3;
 425         }
 426         n = atoi(p);
 427         if (n == 301 || n == 302 || n == 303 || n == 307 || n == 308) {
 428                 p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_LOCATION);
 429                 if (!p) {
 430                         cce = "HS: Redirect code but no Location";
 431                         goto bail3;
 432                 }
 433
 434                 if (lws_parse_uri(p, &prot, &ads, &port, &path)) {
 435                         cce = "HS: URI did not parse";
 436                         goto bail3;
 437                 }
 438
 439                 if (!strcmp(prot, "wss://") || !strcmp(prot, "https://"))
 440                         ssl = 1;
 441
 442                 if (lws_client_reset(wsi, ssl, ads, port, path, ads)) {
 443                         lwsl_err("Redirect failed\n");
 444                         cce = "HS: Redirect failed";
 445                         goto bail3;
 446                 }
 447                 return 0;
 448         }
 449
 450         if (!wsi->do_ws) {
 451                 if (n != 200) {
 452                         lwsl_notice("Connection failed with code %d", n);
 453                         cce = "HS: Server did not return 200";
 454                         goto bail2;
 455                 }
 456
 457 #ifdef LWS_WITH_HTTP_PROXY
 458                 wsi->perform_rewrite = 0;
 459                 if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE)) {
 460                         if (!strncmp(lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE),
 461                                      "text/html", 9))
 462                                 wsi->perform_rewrite = 1;
 463                 }
 464 #endif
 465
 466                 /* allocate the per-connection user memory (if any) */
 467                 if (lws_ensure_user_space(wsi)) {
 468                         lwsl_err("Problem allocating wsi user mem\n");
 469                         cce = "HS: OOM";
 470                         goto bail2;
 471                 }
 472
 473                 /* he may choose to send us stuff in chunked transfer-coding */
 474                 wsi->chunked = 0;
 475                 wsi->chunk_remaining = 0; /* ie, next thing is chunk size */
 476                 if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_TRANSFER_ENCODING)) {
 477                         wsi->chunked = !strcmp(lws_hdr_simple_ptr(wsi,
 478                                                WSI_TOKEN_HTTP_TRANSFER_ENCODING),
 479                                         "chunked");
 480                         /* first thing is hex, after payload there is crlf */
 481                         wsi->chunk_parser = ELCP_HEX;
 482                 }
 483
 484                 if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_CONTENT_LENGTH)) {
 485                         wsi->u.http.content_length =
 486                                         atoi(lws_hdr_simple_ptr(wsi,
 487                                                 WSI_TOKEN_HTTP_CONTENT_LENGTH));
 488                         lwsl_notice("%s: incoming content length %d\n", __func__,
 489                                         wsi->u.http.content_length);
 490                         wsi->u.http.content_remain = wsi->u.http.content_length;
 491                 } else /* can't do 1.1 without a content length or chunked */
 492                         if (!wsi->chunked)
 493                                 wsi->u.http.connection_type = HTTP_CONNECTION_CLOSE;
 494
 495                 /*
 496                  * we seem to be good to go, give client last chance to check
 497                  * headers and OK it
 498                  */
 499                 if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH,
 500                                             wsi->user_space, NULL, 0)) {
 501
 502                         cce = "HS: disallowed by client filter";
 503                         goto bail2;
 504                 }
 505
 506                 /* clear his proxy connection timeout */
 507                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 508
 509                 wsi->rxflow_change_to = LWS_RXFLOW_ALLOW;
 510
 511                 /* call him back to inform him he is up */
 512                 if (wsi->protocol->callback(wsi,
 513                                             LWS_CALLBACK_ESTABLISHED_CLIENT_HTTP,
 514                                             wsi->user_space, NULL, 0)) {
 515                         cce = "HS: disallowed at ESTABLISHED";
 516                         goto bail3;
 517                 }
 518
 519                 /* free up his parsing allocations */
 520                 lws_header_table_detach(wsi, 0);
 521
 522                 lwsl_notice("%s: client connection up\n", __func__);
 523
 524                 return 0;
 525         }
 526
 527         if (lws_hdr_total_length(wsi, WSI_TOKEN_ACCEPT) == 0) {
 528                 lwsl_info("no ACCEPT\n");
 529                 cce = "HS: ACCEPT missing";
 530                 goto bail3;
 531         }
 532
 533         if (p && strncmp(p, "101", 3)) {
 534                 lwsl_warn(
 535                        "lws_client_handshake: got bad HTTP response '%s'\n", p);
 536                 cce = "HS: ws upgrade response not 101";
 537                 goto bail3;
 538         }
 539
 540         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_UPGRADE);
 541         if (!p) {
 542                 lwsl_info("no UPGRADE\n");
 543                 cce = "HS: UPGRADE missing";
 544                 goto bail3;
 545         }
 546         strtolower(p);
 547         if (strcmp(p, "websocket")) {
 548                 lwsl_warn(
 549                       "lws_client_handshake: got bad Upgrade header '%s'\n", p);
 550                 cce = "HS: Upgrade to something other than websocket";
 551                 goto bail3;
 552         }
 553
 554         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_CONNECTION);
 555         if (!p) {
 556                 lwsl_info("no Connection hdr\n");
 557                 cce = "HS: CONNECTION missing";
 558                 goto bail3;
 559         }
 560         strtolower(p);
 561         if (strcmp(p, "upgrade")) {
 562                 lwsl_warn("lws_client_int_s_hs: bad header %s\n", p);
 563                 cce = "HS: UPGRADE malformed";
 564                 goto bail3;
 565         }
 566
 567         pc = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS);
 568         if (!pc) {
 569                 lwsl_parser("lws_client_int_s_hs: no protocol list\n");
 570         } else
 571                 lwsl_parser("lws_client_int_s_hs: protocol list '%s'\n", pc);
 572
 573         /*
 574          * confirm the protocol the server wants to talk was in the list
 575          * of protocols we offered
 576          */
 577
 578         len = lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL);
 579         if (!len) {
 580                 lwsl_info("lws_client_int_s_hs: WSI_TOKEN_PROTOCOL is null\n");
 581                 /*
 582                  * no protocol name to work from,
 583                  * default to first protocol
 584                  */
 585                 wsi->protocol = &wsi->vhost->protocols[0];
 586                 goto check_extensions;
 587         }
 588
 589         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL);
 590         len = strlen(p);
 591
 592         while (pc && *pc && !okay) {
 593                 if (!strncmp(pc, p, len) &&
 594                     (pc[len] == ',' || pc[len] == '\0')) {
 595                         okay = 1;
 596                         continue;
 597                 }
 598                 while (*pc && *pc++ != ',')
 599                         ;
 600                 while (*pc && *pc == ' ')
 601                         pc++;
 602         }
 603
 604         if (!okay) {
 605                 lwsl_err("lws_client_int_s_hs: got bad protocol %s\n", p);
 606                 cce = "HS: PROTOCOL malformed";
 607                 goto bail2;
 608         }
 609
 610         /*
 611          * identify the selected protocol struct and set it
 612          */
 613         n = 0;
 614         wsi->protocol = NULL;
 615         while (wsi->vhost->protocols[n].callback && !wsi->protocol) {
 616                 if (strcmp(p, wsi->vhost->protocols[n].name) == 0) {
 617                         wsi->protocol = &wsi->vhost->protocols[n];
 618                         break;
 619                 }
 620                 n++;
 621         }
 622
 623         if (wsi->protocol == NULL) {
 624                 lwsl_err("lws_client_int_s_hs: fail protocol %s\n", p);
 625                 cce = "HS: Cannot match protocol";
 626                 goto bail2;
 627         }
 628
 629
 630         /*
 631          * stitch protocol choice into the vh protocol linked list
 632          * We always insert ourselves at the start of the list
 633          *
 634          * X <-> B
 635          * X <-> pAn <-> pB
 636          */
 637         //lwsl_err("%s: pre insert vhost start wsi %p, that wsi prev == %p\n",
 638         //              __func__,
 639         //              wsi->vhost->same_vh_protocol_list[n],
 640         //              wsi->same_vh_protocol_prev);
 641         wsi->same_vh_protocol_prev = /* guy who points to us */
 642                 &wsi->vhost->same_vh_protocol_list[n];
 643         wsi->same_vh_protocol_next = /* old first guy is our next */
 644                         wsi->vhost->same_vh_protocol_list[n];
 645         /* we become the new first guy */
 646         wsi->vhost->same_vh_protocol_list[n] = wsi;
 647
 648         if (wsi->same_vh_protocol_next)
 649                 /* old first guy points back to us now */
 650                 wsi->same_vh_protocol_next->same_vh_protocol_prev =
 651                                 &wsi->same_vh_protocol_next;
 652
 653 check_extensions:
 654 #ifndef LWS_NO_EXTENSIONS
 655         /* instantiate the accepted extensions */
 656
 657         if (!lws_hdr_total_length(wsi, WSI_TOKEN_EXTENSIONS)) {
 658                 lwsl_ext("no client extensions allowed by server\n");
 659                 goto check_accept;
 660         }
 661
 662         /*
 663          * break down the list of server accepted extensions
 664          * and go through matching them or identifying bogons
 665          */
 666
 667         if (lws_hdr_copy(wsi, sb, context->pt_serv_buf_size, WSI_TOKEN_EXTENSIONS) < 0) {
 668                 lwsl_warn("ext list from server failed to copy\n");
 669                 cce = "HS: EXT: list too big";
 670                 goto bail2;
 671         }
 672
 673         c = sb;
 674         n = 0;
 675         ignore = 0;
 676         a = NULL;
 677         while (more) {
 678
 679                 if (*c && (*c != ',' && *c != '\t')) {
 680                         if (*c == ';') {
 681                                 ignore = 1;
 682                                 if (!a)
 683                                         a = c + 1;
 684                         }
 685                         if (ignore || *c == ' ') {
 686                                 c++;
 687                                 continue;
 688                         }
 689
 690                         ext_name[n] = *c++;
 691                         if (n < sizeof(ext_name) - 1)
 692                                 n++;
 693                         continue;
 694                 }
 695                 ext_name[n] = '\0';
 696                 ignore = 0;
 697                 if (!*c)
 698                         more = 0;
 699                 else {
 700                         c++;
 701                         if (!n)
 702                                 continue;
 703                 }
 704
 705                 /* check we actually support it */
 706
 707                 lwsl_notice("checking client ext %s\n", ext_name);
 708
 709                 n = 0;
 710                 ext = wsi->vhost->extensions;
 711                 while (ext && ext->callback) {
 712                         if (strcmp(ext_name, ext->name)) {
 713                                 ext++;
 714                                 continue;
 715                         }
 716
 717                         n = 1;
 718                         lwsl_notice("instantiating client ext %s\n", ext_name);
 719
 720                         /* instantiate the extension on this conn */
 721
 722                         wsi->active_extensions[wsi->count_act_ext] = ext;
 723
 724                         /* allow him to construct his ext instance */
 725
 726                         if (ext->callback(lws_get_context(wsi), ext, wsi,
 727                                       LWS_EXT_CB_CLIENT_CONSTRUCT,
 728                                       (void *)&wsi->act_ext_user[wsi->count_act_ext],
 729                                       (void *)&opts, 0)) {
 730                                 lwsl_notice(" ext %s failed construction\n", ext_name);
 731                                 ext++;
 732                                 continue;
 733                         }
 734
 735                         /*
 736                          * allow the user code to override ext defaults if it
 737                          * wants to
 738                          */
 739                         ext_name[0] = '\0';
 740                         if (user_callback_handle_rxflow(wsi->protocol->callback,
 741                                         wsi, LWS_CALLBACK_WS_EXT_DEFAULTS,
 742                                         (char *)ext->name, ext_name,
 743                                         sizeof(ext_name))) {
 744                                 cce = "HS: EXT: failed setting defaults";
 745                                 goto bail2;
 746                         }
 747
 748                         if (ext_name[0] &&
 749                             lws_ext_parse_options(ext, wsi, wsi->act_ext_user[
 750                                                   wsi->count_act_ext], opts, ext_name,
 751                                                   strlen(ext_name))) {
 752                                 lwsl_err("%s: unable to parse user defaults '%s'",
 753                                          __func__, ext_name);
 754                                 cce = "HS: EXT: failed parsing defaults";
 755                                 goto bail2;
 756                         }
 757
 758                         /*
 759                          * give the extension the server options
 760                          */
 761                         if (a && lws_ext_parse_options(ext, wsi,
 762                                         wsi->act_ext_user[wsi->count_act_ext],
 763                                         opts, a, c - a)) {
 764                                 lwsl_err("%s: unable to parse remote def '%s'",
 765                                          __func__, a);
 766                                 cce = "HS: EXT: failed parsing options";
 767                                 goto bail2;
 768                         }
 769
 770                         if (ext->callback(lws_get_context(wsi), ext, wsi,
 771                                         LWS_EXT_CB_OPTION_CONFIRM,
 772                                       wsi->act_ext_user[wsi->count_act_ext],
 773                                       NULL, 0)) {
 774                                 lwsl_err("%s: ext %s rejects server options %s",
 775                                          ext->name, a);
 776                                 cce = "HS: EXT: Rejects server options";
 777                                 goto bail2;
 778                         }
 779
 780                         wsi->count_act_ext++;
 781
 782                         ext++;
 783                 }
 784
 785                 if (n == 0) {
 786                         lwsl_warn("Unknown ext '%s'!\n", ext_name);
 787                         cce = "HS: EXT: unknown ext";
 788                         goto bail2;
 789                 }
 790
 791                 a = NULL;
 792                 n = 0;
 793         }
 794
 795 check_accept:
 796 #endif
 797
 798         /*
 799          * Confirm his accept token is the one we precomputed
 800          */
 801
 802         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_ACCEPT);
 803         if (strcmp(p, wsi->u.hdr.ah->initial_handshake_hash_base64)) {
 804                 lwsl_warn("lws_client_int_s_hs: accept '%s' wrong vs '%s'\n", p,
 805                                   wsi->u.hdr.ah->initial_handshake_hash_base64);
 806                 cce = "HS: Accept hash wrong";
 807                 goto bail2;
 808         }
 809
 810         /* allocate the per-connection user memory (if any) */
 811         if (lws_ensure_user_space(wsi)) {
 812                 lwsl_err("Problem allocating wsi user mem\n");
 813                 cce = "HS: OOM";
 814                 goto bail2;
 815         }
 816
 817         /*
 818          * we seem to be good to go, give client last chance to check
 819          * headers and OK it
 820          */
 821         if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH,
 822                                     wsi->user_space, NULL, 0)) {
 823                 cce = "HS: Rejected by filter cb";
 824                 goto bail2;
 825         }
 826
 827         /* clear his proxy connection timeout */
 828         lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 829
 830         /* free up his parsing allocations */
 831         lws_header_table_detach(wsi, 0);
 832
 833         lws_union_transition(wsi, LWSCM_WS_CLIENT);
 834         wsi->state = LWSS_ESTABLISHED;
 835         lws_restart_ws_ping_pong_timer(wsi);
 836
 837         wsi->rxflow_change_to = LWS_RXFLOW_ALLOW;
 838
 839         /*
 840          * create the frame buffer for this connection according to the
 841          * size mentioned in the protocol definition.  If 0 there, then
 842          * use a big default for compatibility
 843          */
 844         n = wsi->protocol->rx_buffer_size;
 845         if (!n)
 846                 n = context->pt_serv_buf_size;
 847         n += LWS_PRE;
 848         wsi->u.ws.rx_ubuf = lws_malloc(n + 4 /* 0x0000ffff zlib */);
 849         if (!wsi->u.ws.rx_ubuf) {
 850                 lwsl_err("Out of Mem allocating rx buffer %d\n", n);
 851                 cce = "HS: OOM";
 852                 goto bail2;
 853         }
 854        wsi->u.ws.rx_ubuf_alloc = n;
 855         lwsl_info("Allocating client RX buffer %d\n", n);
 856
 857         if (setsockopt(wsi->sock, SOL_SOCKET, SO_SNDBUF, (const char *)&n,
 858                        sizeof n)) {
 859                 lwsl_warn("Failed to set SNDBUF to %d", n);
 860                 cce = "HS: SO_SNDBUF failed";
 861                 goto bail3;
 862         }
 863
 864         lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
 865
 866         /* call him back to inform him he is up */
 867
 868         if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_ESTABLISHED,
 869                                     wsi->user_space, NULL, 0)) {
 870                 cce = "HS: Rejected at CLIENT_ESTABLISHED";
 871                 goto bail3;
 872         }
 873 #ifndef LWS_NO_EXTENSIONS
 874         /*
 875          * inform all extensions, not just active ones since they
 876          * already know
 877          */
 878         ext = wsi->vhost->extensions;
 879
 880         while (ext && ext->callback) {
 881                 v = NULL;
 882                 for (n = 0; n < wsi->count_act_ext; n++)
 883                         if (wsi->active_extensions[n] == ext)
 884                                 v = wsi->act_ext_user[n];
 885
 886                 ext->callback(context, ext, wsi,
 887                           LWS_EXT_CB_ANY_WSI_ESTABLISHED, v, NULL, 0);
 888                 ext++;
 889         }
 890 #endif
 891
 892         return 0;
 893
 894 bail3:
 895         close_reason = LWS_CLOSE_STATUS_NOSTATUS;
 896
 897 bail2:
 898         wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 899                                 wsi->user_space, (void *)cce,
 900                                 (unsigned int) (cce ? strlen(cce): 0));
 901         wsi->already_did_cce = 1;
 902
 903         lwsl_info("closing connection due to bail2 connection error\n");
 904
 905         /* closing will free up his parsing allocations */
 906         lws_close_free_wsi(wsi, close_reason);
 907
 908         return 1;
 909 }
 910
 911
 912 char *
 913 lws_generate_client_handshake(struct lws *wsi, char *pkt)
 914 {
 915         char buf[128], hash[20], key_b64[40], *p = pkt;
 916         struct lws_context *context = wsi->context;
 917         const char *meth;
 918         int n;
 919 #ifndef LWS_NO_EXTENSIONS
 920         const struct lws_extension *ext;
 921         int ext_count = 0;
 922 #endif
 923
 924         meth = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_METHOD);
 925         if (!meth) {
 926                 meth = "GET";
 927                 wsi->do_ws = 1;
 928         } else
 929                 wsi->do_ws = 0;
 930
 931         if (wsi->do_ws) {
 932                 /*
 933                  * create the random key
 934                  */
 935                 n = lws_get_random(context, hash, 16);
 936                 if (n != 16) {
 937                         lwsl_err("Unable to read from random dev %s\n",
 938                                  SYSTEM_RANDOM_FILEPATH);
 939                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 940                         return NULL;
 941                 }
 942
 943                 lws_b64_encode_string(hash, 16, key_b64, sizeof(key_b64));
 944         }
 945
 946         /*
 947          * 04 example client handshake
 948          *
 949          * GET /chat HTTP/1.1
 950          * Host: server.example.com
 951          * Upgrade: websocket
 952          * Connection: Upgrade
 953          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 954          * Sec-WebSocket-Origin: http://example.com
 955          * Sec-WebSocket-Protocol: chat, superchat
 956          * Sec-WebSocket-Version: 4
 957          */
 958
 959         p += sprintf(p, "%s %s HTTP/1.1\x0d\x0a", meth,
 960                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_URI));
 961
 962         p += sprintf(p, "Pragma: no-cache\x0d\x0a"
 963                         "Cache-Control: no-cache\x0d\x0a");
 964
 965         p += sprintf(p, "Host: %s\x0d\x0a",
 966                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_HOST));
 967
 968         if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN))
 969                 p += sprintf(p, "Origin: http://%s\x0d\x0a",
 970                              lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN));
 971
 972         if (wsi->do_ws) {
 973                 p += sprintf(p, "Upgrade: websocket\x0d\x0a"
 974                                 "Connection: Upgrade\x0d\x0a"
 975                                 "Sec-WebSocket-Key: ");
 976                 strcpy(p, key_b64);
 977                 p += strlen(key_b64);
 978                 p += sprintf(p, "\x0d\x0a");
 979                 if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS))
 980                         p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 981                              lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS));
 982
 983                 /* tell the server what extensions we could support */
 984
 985 #ifndef LWS_NO_EXTENSIONS
 986                 ext = wsi->vhost->extensions;
 987                 while (ext && ext->callback) {
 988                         n = lws_ext_cb_all_exts(context, wsi,
 989                                    LWS_EXT_CB_CHECK_OK_TO_PROPOSE_EXTENSION,
 990                                    (char *)ext->name, 0);
 991                         if (n) { /* an extension vetos us */
 992                                 lwsl_ext("ext %s vetoed\n", (char *)ext->name);
 993                                 ext++;
 994                                 continue;
 995                         }
 996                         n = wsi->vhost->protocols[0].callback(wsi,
 997                                 LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
 998                                         wsi->user_space, (char *)ext->name, 0);
 999
1000                         /*
1001                          * zero return from callback means
1002                          * go ahead and allow the extension,
1003                          * it's what we get if the callback is
1004                          * unhandled
1005                          */
1006
1007                         if (n) {
1008                                 ext++;
1009                                 continue;
1010                         }
1011
1012                         /* apply it */
1013
1014                         if (ext_count)
1015                                 *p++ = ',';
1016                         else
1017                                 p += sprintf(p, "Sec-WebSocket-Extensions: ");
1018                         p += sprintf(p, "%s", ext->client_offer);
1019                         ext_count++;
1020
1021                         ext++;
1022                 }
1023                 if (ext_count)
1024                         p += sprintf(p, "\x0d\x0a");
1025 #endif
1026
1027                 if (wsi->ietf_spec_revision)
1028                         p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
1029                                      wsi->ietf_spec_revision);
1030
1031                 /* prepare the expected server accept response */
1032
1033                 key_b64[39] = '\0'; /* enforce composed length below buf sizeof */
1034                 n = sprintf(buf, "%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11", key_b64);
1035
1036                 lws_SHA1((unsigned char *)buf, n, (unsigned char *)hash);
1037
1038                 lws_b64_encode_string(hash, 20,
1039                                       wsi->u.hdr.ah->initial_handshake_hash_base64,
1040                                       sizeof(wsi->u.hdr.ah->initial_handshake_hash_base64));
1041         }
1042
1043         /* give userland a chance to append, eg, cookies */
1044
1045         wsi->vhost->protocols[0].callback(wsi, LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
1046                                 wsi->user_space, &p, (pkt + context->pt_serv_buf_size) - p - 12);
1047
1048         p += sprintf(p, "\x0d\x0a");
1049
1050         return p;
1051 }
1052