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 lws_handshake_client(struct lws *wsi, unsigned char **buf, size_t len)
  25 {
  26         unsigned int n;
  27
  28         switch (wsi->mode) {
  29         case LWSCM_WSCL_WAITING_PROXY_REPLY:
  30         case LWSCM_WSCL_ISSUE_HANDSHAKE:
  31         case LWSCM_WSCL_WAITING_SERVER_REPLY:
  32         case LWSCM_WSCL_WAITING_EXTENSION_CONNECT:
  33         case LWSCM_WS_CLIENT:
  34                 for (n = 0; n < len; n++)
  35                         if (lws_client_rx_sm(wsi, *(*buf)++)) {
  36                                 lwsl_debug("client_rx_sm failed\n");
  37                                 return 1;
  38                         }
  39                 return 0;
  40         default:
  41                 break;
  42         }
  43         return 0;
  44 }
  45
  46 int lws_client_socket_service(struct lws_context *context,
  47                               struct lws *wsi, struct lws_pollfd *pollfd)
  48 {
  49         char *p = (char *)&context->serv_buf[0];
  50         unsigned char c;
  51         int n, len;
  52
  53         switch (wsi->mode) {
  54
  55         case LWSCM_WSCL_WAITING_CONNECT:
  56
  57                 /*
  58                  * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
  59                  * timeout protection set in client-handshake.c
  60                  */
  61
  62                if (lws_client_connect_2(wsi) == NULL) {
  63                         /* closed */
  64                         lwsl_client("closed\n");
  65                         return -1;
  66                 }
  67
  68                 /* either still pending connection, or changed mode */
  69                 return 0;
  70
  71         case LWSCM_WSCL_WAITING_PROXY_REPLY:
  72
  73                 /* handle proxy hung up on us */
  74
  75                 if (pollfd->revents & LWS_POLLHUP) {
  76
  77                         lwsl_warn("Proxy connection %p (fd=%d) dead\n",
  78                                   (void *)wsi, pollfd->fd);
  79
  80                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
  81                         return 0;
  82                 }
  83
  84                 n = recv(wsi->sock, (char *)context->serv_buf,
  85                                         sizeof(context->serv_buf), 0);
  86                 if (n < 0) {
  87
  88                         if (LWS_ERRNO == LWS_EAGAIN) {
  89                                 lwsl_debug("Proxy read returned EAGAIN... retrying\n");
  90                                 return 0;
  91                         }
  92
  93                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
  94                         lwsl_err("ERROR reading from proxy socket\n");
  95                         return 0;
  96                 }
  97
  98                 context->serv_buf[13] = '\0';
  99                 if (strcmp((char *)context->serv_buf, "HTTP/1.0 200 ") &&
 100                     strcmp((char *)context->serv_buf, "HTTP/1.1 200 ")
 101                 ) {
 102                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 103                         lwsl_err("ERROR proxy: %s\n", context->serv_buf);
 104                         return 0;
 105                 }
 106
 107                 /* clear his proxy connection timeout */
 108
 109                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 110
 111                 /* fallthru */
 112
 113         case LWSCM_WSCL_ISSUE_HANDSHAKE:
 114
 115                 /*
 116                  * we are under PENDING_TIMEOUT_SENT_CLIENT_HANDSHAKE
 117                  * timeout protection set in client-handshake.c
 118                  */
 119
 120                 /*
 121                  * take care of our lws_callback_on_writable
 122                  * happening at a time when there's no real connection yet
 123                  */
 124                 if (lws_change_pollfd(wsi, LWS_POLLOUT, 0))
 125                         return -1;
 126                 lws_libev_io(wsi, LWS_EV_STOP | LWS_EV_WRITE);
 127
 128 #ifdef LWS_OPENSSL_SUPPORT
 129                 /* we can retry this... just cook the SSL BIO the first time */
 130
 131                 if (wsi->use_ssl && !wsi->ssl) {
 132 #if defined(CYASSL_SNI_HOST_NAME) || defined(WOLFSSL_SNI_HOST_NAME) || defined(SSL_CTRL_SET_TLSEXT_HOSTNAME)
 133                         const char *hostname = lws_hdr_simple_ptr(wsi,
 134                                                 _WSI_TOKEN_CLIENT_HOST);
 135 #endif
 136
 137                         wsi->ssl = SSL_new(context->ssl_client_ctx);
 138 #ifndef USE_WOLFSSL
 139                         SSL_set_mode(wsi->ssl,
 140                                         SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 141 #endif
 142                         /*
 143                          * use server name indication (SNI), if supported,
 144                          * when establishing connection
 145                          */
 146 #ifdef USE_WOLFSSL
 147 #ifdef USE_OLD_CYASSL
 148 #ifdef CYASSL_SNI_HOST_NAME
 149                         CyaSSL_UseSNI(wsi->ssl, CYASSL_SNI_HOST_NAME,
 150                                 hostname, strlen(hostname));
 151 #endif
 152 #else
 153 #ifdef WOLFSSL_SNI_HOST_NAME
 154                         wolfSSL_UseSNI(wsi->ssl, WOLFSSL_SNI_HOST_NAME,
 155                                 hostname, strlen(hostname));
 156 #endif
 157 #endif
 158 #else
 159 #ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
 160                         SSL_set_tlsext_host_name(wsi->ssl, hostname);
 161 #endif
 162 #endif
 163
 164 #ifdef USE_WOLFSSL
 165                         /*
 166                          * wolfSSL/CyaSSL does certificate verification differently
 167                          * from OpenSSL.
 168                          * If we should ignore the certificate, we need to set
 169                          * this before SSL_new and SSL_connect is called.
 170                          * Otherwise the connect will simply fail with error
 171                          * code -155
 172                          */
 173 #ifdef USE_OLD_CYASSL
 174                         if (wsi->use_ssl == 2)
 175                                 CyaSSL_set_verify(wsi->ssl,
 176                                                         SSL_VERIFY_NONE, NULL);
 177 #else
 178                         if (wsi->use_ssl == 2)
 179                                 wolfSSL_set_verify(wsi->ssl,
 180                                                         SSL_VERIFY_NONE, NULL);
 181 #endif
 182 #endif /* USE_WOLFSSL */
 183
 184                         wsi->client_bio =
 185                                 BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 186                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 187
 188 #ifdef USE_WOLFSSL
 189 #ifdef USE_OLD_CYASSL
 190                         CyaSSL_set_using_nonblock(wsi->ssl, 1);
 191 #else
 192                         wolfSSL_set_using_nonblock(wsi->ssl, 1);
 193 #endif
 194 #else
 195                         BIO_set_nbio(wsi->client_bio, 1); /* nonblocking */
 196 #endif
 197
 198                         SSL_set_ex_data(wsi->ssl,
 199                                         openssl_websocket_private_data_index,
 200                                                                        context);
 201                 }
 202
 203                 if (wsi->use_ssl) {
 204                         lws_latency_pre(context, wsi);
 205                         n = SSL_connect(wsi->ssl);
 206                         lws_latency(context, wsi,
 207                           "SSL_connect LWSCM_WSCL_ISSUE_HANDSHAKE",
 208                                                                       n, n > 0);
 209
 210                         if (n < 0) {
 211                                 n = SSL_get_error(wsi->ssl, n);
 212
 213                                 if (n == SSL_ERROR_WANT_READ)
 214                                         goto some_wait;
 215
 216                                 if (n == SSL_ERROR_WANT_WRITE) {
 217                                         /*
 218                                          * wants us to retry connect due to
 219                                          * state of the underlying ssl layer...
 220                                          * but since it may be stalled on
 221                                          * blocked write, no incoming data may
 222                                          * arrive to trigger the retry.
 223                                          * Force (possibly many times if the SSL
 224                                          * state persists in returning the
 225                                          * condition code, but other sockets
 226                                          * are getting serviced inbetweentimes)
 227                                          * us to get called back when writable.
 228                                          */
 229
 230                                         lwsl_info(
 231                                              "SSL_connect WANT_WRITE... retrying\n");
 232                                         lws_callback_on_writable(wsi);
 233 some_wait:
 234                                         wsi->mode = LWSCM_WSCL_WAITING_SSL;
 235
 236                                         return 0; /* no error */
 237                                 }
 238                                 n = -1;
 239                         }
 240
 241                         if (n <= 0) {
 242                                 /*
 243                                  * retry if new data comes until we
 244                                  * run into the connection timeout or win
 245                                  */
 246
 247                                 n = ERR_get_error();
 248                                 if (n != SSL_ERROR_NONE) {
 249                                         lwsl_err("SSL connect error %lu: %s\n",
 250                                                 n,
 251                                                 ERR_error_string(n,
 252                                                           (char *)context->serv_buf));
 253                                         return 0;
 254                                 }
 255                         }
 256                 } else
 257                         wsi->ssl = NULL;
 258
 259                 /* fallthru */
 260
 261         case LWSCM_WSCL_WAITING_SSL:
 262
 263                 if (wsi->use_ssl) {
 264
 265                         if (wsi->mode == LWSCM_WSCL_WAITING_SSL) {
 266                                 lws_latency_pre(context, wsi);
 267                                 n = SSL_connect(wsi->ssl);
 268                                 lws_latency(context, wsi,
 269                                             "SSL_connect LWSCM_WSCL_WAITING_SSL",
 270                                             n, n > 0);
 271
 272                                 if (n < 0) {
 273                                         n = SSL_get_error(wsi->ssl, n);
 274
 275                                         if (n == SSL_ERROR_WANT_READ)
 276                                                 goto some_wait;
 277
 278                                         if (n == SSL_ERROR_WANT_WRITE) {
 279                                                 /*
 280                                                  * wants us to retry connect due to
 281                                                  * state of the underlying ssl layer...
 282                                                  * but since it may be stalled on
 283                                                  * blocked write, no incoming data may
 284                                                  * arrive to trigger the retry.
 285                                                  * Force (possibly many times if the SSL
 286                                                  * state persists in returning the
 287                                                  * condition code, but other sockets
 288                                                  * are getting serviced inbetweentimes)
 289                                                  * us to get called back when writable.
 290                                                  */
 291
 292                                                 lwsl_info("SSL_connect WANT_WRITE... retrying\n");
 293                                                 lws_callback_on_writable(wsi);
 294
 295                                                 goto some_wait;
 296                                         }
 297                                         n = -1;
 298                                 }
 299
 300                                 if (n <= 0) {
 301                                         /*
 302                                          * retry if new data comes until we
 303                                          * run into the connection timeout or win
 304                                          */
 305                                         n = ERR_get_error();
 306                                         if (n != SSL_ERROR_NONE) {
 307                                                 lwsl_err("SSL connect error %lu: %s\n",
 308                                                          n, ERR_error_string(n,
 309                                                          (char *)context->serv_buf));
 310                                                 return 0;
 311                                         }
 312                                 }
 313                         }
 314
 315                         #ifndef USE_WOLFSSL
 316                         /*
 317                          * See comment above about wolfSSL certificate
 318                          * verification
 319                          */
 320                         lws_latency_pre(context, wsi);
 321                         n = SSL_get_verify_result(wsi->ssl);
 322                         lws_latency(context, wsi,
 323                                 "SSL_get_verify_result LWS_CONNMODE..HANDSHAKE",
 324                                                                       n, n > 0);
 325
 326                         if (n != X509_V_OK) {
 327                                 if ((n == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 328                                      n == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) && wsi->use_ssl == 2) {
 329                                         lwsl_notice("accepting self-signed certificate\n");
 330                                 } else {
 331                                         lwsl_err("server's cert didn't look good, X509_V_ERR = %d: %s\n",
 332                                                  n, ERR_error_string(n, (char *)context->serv_buf));
 333                                         lws_close_free_wsi(wsi,
 334                                                 LWS_CLOSE_STATUS_NOSTATUS);
 335                                         return 0;
 336                                 }
 337                         }
 338 #endif /* USE_WOLFSSL */
 339                 } else
 340                         wsi->ssl = NULL;
 341 #endif
 342
 343                 wsi->mode = LWSCM_WSCL_ISSUE_HANDSHAKE2;
 344                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_CLIENT_HS_SEND,
 345                                 AWAITING_TIMEOUT);
 346
 347                 /* fallthru */
 348
 349         case LWSCM_WSCL_ISSUE_HANDSHAKE2:
 350                 p = lws_generate_client_handshake(wsi, p);
 351                 if (p == NULL) {
 352                         lwsl_err("Failed to generate handshake for client\n");
 353                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 354                         return 0;
 355                 }
 356
 357                 /* send our request to the server */
 358
 359                 lws_latency_pre(context, wsi);
 360
 361                 n = lws_ssl_capable_write(wsi, context->serv_buf,
 362                                           p - (char *)context->serv_buf);
 363                 lws_latency(context, wsi, "send lws_issue_raw", n,
 364                             n == p - (char *)context->serv_buf);
 365                 switch (n) {
 366                 case LWS_SSL_CAPABLE_ERROR:
 367                         lwsl_debug("ERROR writing to client socket\n");
 368                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 369                         return 0;
 370                 case LWS_SSL_CAPABLE_MORE_SERVICE:
 371                         lws_callback_on_writable(wsi);
 372                         break;
 373                 }
 374
 375                 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 376                 wsi->u.hdr.lextable_pos = 0;
 377                 wsi->mode = LWSCM_WSCL_WAITING_SERVER_REPLY;
 378                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE,
 379                                 AWAITING_TIMEOUT);
 380                 break;
 381
 382         case LWSCM_WSCL_WAITING_SERVER_REPLY:
 383
 384                 /* handle server hung up on us */
 385
 386                 if (pollfd->revents & LWS_POLLHUP) {
 387
 388                         lwsl_debug("Server connection %p (fd=%d) dead\n",
 389                                 (void *)wsi, pollfd->fd);
 390
 391                         goto bail3;
 392                 }
 393
 394                 if (!(pollfd->revents & LWS_POLLIN))
 395                         break;
 396
 397                 /* interpret the server response */
 398
 399                 /*
 400                  *  HTTP/1.1 101 Switching Protocols
 401                  *  Upgrade: websocket
 402                  *  Connection: Upgrade
 403                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 404                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 405                  *  Sec-WebSocket-Protocol: chat
 406                  */
 407
 408                 /*
 409                  * we have to take some care here to only take from the
 410                  * socket bytewise.  The browser may (and has been seen to
 411                  * in the case that onopen() performs websocket traffic)
 412                  * coalesce both handshake response and websocket traffic
 413                  * in one packet, since at that point the connection is
 414                  * definitively ready from browser pov.
 415                  */
 416                 len = 1;
 417                 while (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE &&
 418                        len > 0) {
 419                         n = lws_ssl_capable_read(wsi, &c, 1);
 420                         lws_latency(context, wsi, "send lws_issue_raw", n,
 421                                     n == 1);
 422                         switch (n) {
 423                         case LWS_SSL_CAPABLE_ERROR:
 424                                 goto bail3;
 425                         case LWS_SSL_CAPABLE_MORE_SERVICE:
 426                                 return 0;
 427                         }
 428
 429                         if (lws_parse(wsi, c)) {
 430                                 lwsl_warn("problems parsing header\n");
 431                                 goto bail3;
 432                         }
 433                 }
 434
 435                 /*
 436                  * hs may also be coming in multiple packets, there is a 5-sec
 437                  * libwebsocket timeout still active here too, so if parsing did
 438                  * not complete just wait for next packet coming in this state
 439                  */
 440
 441                 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
 442                         break;
 443
 444                 /*
 445                  * otherwise deal with the handshake.  If there's any
 446                  * packet traffic already arrived we'll trigger poll() again
 447                  * right away and deal with it that way
 448                  */
 449
 450                 return lws_client_interpret_server_handshake(wsi);
 451
 452 bail3:
 453                 lwsl_info("closing conn at LWS_CONNMODE...SERVER_REPLY\n");
 454                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 455                 return -1;
 456
 457         case LWSCM_WSCL_WAITING_EXTENSION_CONNECT:
 458                 lwsl_ext("LWSCM_WSCL_WAITING_EXTENSION_CONNECT\n");
 459                 break;
 460
 461         case LWSCM_WSCL_PENDING_CANDIDATE_CHILD:
 462                 lwsl_ext("LWSCM_WSCL_PENDING_CANDIDATE_CHILD\n");
 463                 break;
 464         default:
 465                 break;
 466         }
 467
 468         return 0;
 469 }
 470
 471
 472 /*
 473  * In-place str to lower case
 474  */
 475
 476 static void
 477 strtolower(char *s)
 478 {
 479         while (*s) {
 480                 *s = tolower((int)*s);
 481                 s++;
 482         }
 483 }
 484
 485 int
 486 lws_client_interpret_server_handshake(struct lws *wsi)
 487 {
 488         struct lws_context *context = wsi->context;
 489         int close_reason = LWS_CLOSE_STATUS_PROTOCOL_ERR;
 490         int n, len, okay = 0, isErrorCodeReceived = 0;
 491         const char *pc;
 492         char *p;
 493 #ifndef LWS_NO_EXTENSIONS
 494         const struct lws_extension *ext;
 495         char ext_name[128];
 496         const char *c;
 497         int more = 1;
 498         void *v;
 499 #endif
 500
 501         /*
 502          * well, what the server sent looked reasonable for syntax.
 503          * Now let's confirm it sent all the necessary headers
 504          */
 505
 506         if (lws_hdr_total_length(wsi, WSI_TOKEN_ACCEPT) == 0) {
 507                 lwsl_info("no ACCEPT\n");
 508                 p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP);
 509                 isErrorCodeReceived = 1;
 510                 goto bail3;
 511         }
 512
 513         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP);
 514         if (!p) {
 515                 lwsl_info("no URI\n");
 516                 goto bail3;
 517         }
 518         if (p && strncmp(p, "101", 3)) {
 519                 lwsl_warn(
 520                        "lws_client_handshake: got bad HTTP response '%s'\n", p);
 521                 goto bail3;
 522         }
 523
 524         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_UPGRADE);
 525         if (!p) {
 526                 lwsl_info("no UPGRADE\n");
 527                 goto bail3;
 528         }
 529         strtolower(p);
 530         if (strcmp(p, "websocket")) {
 531                 lwsl_warn(
 532                       "lws_client_handshake: got bad Upgrade header '%s'\n", p);
 533                 goto bail3;
 534         }
 535
 536         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_CONNECTION);
 537         if (!p) {
 538                 lwsl_info("no Connection hdr\n");
 539                 goto bail3;
 540         }
 541         strtolower(p);
 542         if (strcmp(p, "upgrade")) {
 543                 lwsl_warn("lws_client_int_s_hs: bad header %s\n", p);
 544                 goto bail3;
 545         }
 546
 547         pc = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS);
 548         if (!pc) {
 549                 lwsl_parser("lws_client_int_s_hs: no protocol list\n");
 550         } else
 551                 lwsl_parser("lws_client_int_s_hs: protocol list '%s'\n", pc);
 552
 553         /*
 554          * confirm the protocol the server wants to talk was in the list
 555          * of protocols we offered
 556          */
 557
 558         len = lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL);
 559         if (!len) {
 560
 561                 lwsl_info("lws_client_int_s_hs: WSI_TOKEN_PROTOCOL is null\n");
 562                 /*
 563                  * no protocol name to work from,
 564                  * default to first protocol
 565                  */
 566                 wsi->protocol = &context->protocols[0];
 567                 goto check_extensions;
 568         }
 569
 570         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL);
 571         len = strlen(p);
 572
 573         while (pc && *pc && !okay) {
 574                 if (!strncmp(pc, p, len) &&
 575                     (pc[len] == ',' || pc[len] == '\0')) {
 576                         okay = 1;
 577                         continue;
 578                 }
 579                 while (*pc && *pc++ != ',')
 580                         ;
 581                 while (*pc && *pc == ' ')
 582                         pc++;
 583         }
 584
 585         if (!okay) {
 586                 lwsl_err("lws_client_int_s_hs: got bad protocol %s\n", p);
 587                 goto bail2;
 588         }
 589
 590         /*
 591          * identify the selected protocol struct and set it
 592          */
 593         n = 0;
 594         wsi->protocol = NULL;
 595         while (context->protocols[n].callback && !wsi->protocol) {
 596                 if (strcmp(p, context->protocols[n].name) == 0) {
 597                         wsi->protocol = &context->protocols[n];
 598                         break;
 599                 }
 600                 n++;
 601         }
 602
 603         if (wsi->protocol == NULL) {
 604                 lwsl_err("lws_client_int_s_hs: fail protocol %s\n", p);
 605                 goto bail2;
 606         }
 607
 608
 609 check_extensions:
 610 #ifndef LWS_NO_EXTENSIONS
 611         /* instantiate the accepted extensions */
 612
 613         if (!lws_hdr_total_length(wsi, WSI_TOKEN_EXTENSIONS)) {
 614                 lwsl_ext("no client extenstions allowed by server\n");
 615                 goto check_accept;
 616         }
 617
 618         /*
 619          * break down the list of server accepted extensions
 620          * and go through matching them or identifying bogons
 621          */
 622
 623         if (lws_hdr_copy(wsi, (char *)context->serv_buf,
 624                    sizeof(context->serv_buf), WSI_TOKEN_EXTENSIONS) < 0) {
 625                 lwsl_warn("ext list from server failed to copy\n");
 626                 goto bail2;
 627         }
 628
 629         c = (char *)context->serv_buf;
 630         n = 0;
 631         while (more) {
 632
 633                 if (*c && (*c != ',' && *c != ' ' && *c != '\t')) {
 634                         ext_name[n] = *c++;
 635                         if (n < sizeof(ext_name) - 1)
 636                                 n++;
 637                         continue;
 638                 }
 639                 ext_name[n] = '\0';
 640                 if (!*c)
 641                         more = 0;
 642                 else {
 643                         c++;
 644                         if (!n)
 645                                 continue;
 646                 }
 647
 648                 /* check we actually support it */
 649
 650                 lwsl_ext("checking client ext %s\n", ext_name);
 651
 652                 n = 0;
 653                 ext = lws_get_context(wsi)->extensions;
 654                 while (ext && ext->callback) {
 655                         if (strcmp(ext_name, ext->name)) {
 656                                 ext++;
 657                                 continue;
 658                         }
 659
 660                         n = 1;
 661                         lwsl_ext("instantiating client ext %s\n", ext_name);
 662
 663                         /* instantiate the extension on this conn */
 664
 665                         wsi->active_extensions_user[
 666                                 wsi->count_active_extensions] =
 667                                          lws_zalloc(ext->per_session_data_size);
 668                         if (wsi->active_extensions_user[
 669                                 wsi->count_active_extensions] == NULL) {
 670                                 lwsl_err("Out of mem\n");
 671                                 goto bail2;
 672                         }
 673                         wsi->active_extensions[
 674                                   wsi->count_active_extensions] = ext;
 675
 676                         /* allow him to construct his context */
 677
 678                         ext->callback(lws_get_context(wsi), ext, wsi,
 679                                       LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
 680                                       wsi->active_extensions_user[
 681                                          wsi->count_active_extensions],
 682                                       NULL, 0);
 683
 684                         wsi->count_active_extensions++;
 685
 686                         ext++;
 687                 }
 688
 689                 if (n == 0) {
 690                         lwsl_warn("Unknown ext '%s'!\n", ext_name);
 691                         goto bail2;
 692                 }
 693
 694                 n = 0;
 695         }
 696
 697 check_accept:
 698 #endif
 699
 700         /*
 701          * Confirm his accept token is the one we precomputed
 702          */
 703
 704         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_ACCEPT);
 705         if (strcmp(p, wsi->u.hdr.ah->initial_handshake_hash_base64)) {
 706                 lwsl_warn("lws_client_int_s_hs: accept %s wrong vs %s\n", p,
 707                                   wsi->u.hdr.ah->initial_handshake_hash_base64);
 708                 goto bail2;
 709         }
 710
 711         /* allocate the per-connection user memory (if any) */
 712         if (lws_ensure_user_space(wsi)) {
 713                 lwsl_err("Problem allocating wsi user mem\n");
 714                 goto bail2;
 715         }
 716
 717         /*
 718          * we seem to be good to go, give client last chance to check
 719          * headers and OK it
 720          */
 721         if (wsi->protocol->callback(wsi,
 722                                     LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH,
 723                                     wsi->user_space, NULL, 0))
 724                 goto bail2;
 725
 726         /* clear his proxy connection timeout */
 727
 728         lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 729
 730         /* free up his parsing allocations */
 731
 732         lws_free(wsi->u.hdr.ah);
 733
 734         lws_union_transition(wsi, LWSCM_WS_CLIENT);
 735         wsi->state = LWSS_ESTABLISHED;
 736
 737         wsi->rxflow_change_to = LWS_RXFLOW_ALLOW;
 738
 739         /*
 740          * create the frame buffer for this connection according to the
 741          * size mentioned in the protocol definition.  If 0 there, then
 742          * use a big default for compatibility
 743          */
 744
 745         n = wsi->protocol->rx_buffer_size;
 746         if (!n)
 747                 n = LWS_MAX_SOCKET_IO_BUF;
 748         n += LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING;
 749         wsi->u.ws.rx_user_buffer = lws_malloc(n);
 750         if (!wsi->u.ws.rx_user_buffer) {
 751                 lwsl_err("Out of Mem allocating rx buffer %d\n", n);
 752                 goto bail2;
 753         }
 754         lwsl_info("Allocating client RX buffer %d\n", n);
 755
 756         if (setsockopt(wsi->sock, SOL_SOCKET, SO_SNDBUF, (const char *)&n,
 757                        sizeof n)) {
 758                 lwsl_warn("Failed to set SNDBUF to %d", n);
 759                 goto bail3;
 760         }
 761
 762         lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
 763
 764         /* call him back to inform him he is up */
 765
 766         if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_ESTABLISHED,
 767                                     wsi->user_space, NULL, 0))
 768                 goto bail3;
 769 #ifndef LWS_NO_EXTENSIONS
 770         /*
 771          * inform all extensions, not just active ones since they
 772          * already know
 773          */
 774
 775         ext = context->extensions;
 776
 777         while (ext && ext->callback) {
 778                 v = NULL;
 779                 for (n = 0; n < wsi->count_active_extensions; n++)
 780                         if (wsi->active_extensions[n] == ext)
 781                                 v = wsi->active_extensions_user[n];
 782
 783                 ext->callback(context, ext, wsi,
 784                           LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED, v, NULL, 0);
 785                 ext++;
 786         }
 787 #endif
 788
 789         return 0;
 790
 791 bail3:
 792         lws_free_set_NULL(wsi->u.ws.rx_user_buffer);
 793         close_reason = LWS_CLOSE_STATUS_NOSTATUS;
 794
 795 bail2:
 796         if (wsi->protocol) {
 797                 if (isErrorCodeReceived && p) {
 798                         wsi->protocol->callback(wsi,
 799                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 800                                                 wsi->user_space, p,
 801                                                 (unsigned int)strlen(p));
 802                 } else {
 803                         wsi->protocol->callback(wsi,
 804                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 805                                                 wsi->user_space, NULL, 0);
 806                 }
 807         }
 808
 809         lwsl_info("closing connection due to bail2 connection error\n");
 810
 811         /* free up his parsing allocations */
 812         lws_free_set_NULL(wsi->u.hdr.ah);
 813         lws_close_free_wsi(wsi, close_reason);
 814
 815         return 1;
 816 }
 817
 818
 819 char *
 820 lws_generate_client_handshake(struct lws *wsi, char *pkt)
 821 {
 822         char buf[128], hash[20], key_b64[40], *p = pkt;
 823         struct lws_context *context = wsi->context;
 824         int n;
 825 #ifndef LWS_NO_EXTENSIONS
 826         const struct lws_extension *ext;
 827         int ext_count = 0;
 828 #endif
 829
 830         /*
 831          * create the random key
 832          */
 833         n = lws_get_random(context, hash, 16);
 834         if (n != 16) {
 835                 lwsl_err("Unable to read from random dev %s\n",
 836                          SYSTEM_RANDOM_FILEPATH);
 837                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 838                 return NULL;
 839         }
 840
 841         lws_b64_encode_string(hash, 16, key_b64, sizeof(key_b64));
 842
 843         /*
 844          * 00 example client handshake
 845          *
 846          * GET /socket.io/websocket HTTP/1.1
 847          * Upgrade: WebSocket
 848          * Connection: Upgrade
 849          * Host: 127.0.0.1:9999
 850          * Origin: http://127.0.0.1
 851          * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7  92 ^
 852          * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
 853          * Cookie: socketio=websocket
 854          *
 855          * (Á®Ä0¶†≥
 856          *
 857          * 04 example client handshake
 858          *
 859          * GET /chat HTTP/1.1
 860          * Host: server.example.com
 861          * Upgrade: websocket
 862          * Connection: Upgrade
 863          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 864          * Sec-WebSocket-Origin: http://example.com
 865          * Sec-WebSocket-Protocol: chat, superchat
 866          * Sec-WebSocket-Version: 4
 867          */
 868
 869         p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a",
 870                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_URI));
 871
 872         p += sprintf(p, "Pragma: no-cache\x0d\x0a"
 873                         "Cache-Control: no-cache\x0d\x0a");
 874
 875         p += sprintf(p, "Host: %s\x0d\x0a",
 876                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_HOST));
 877         p += sprintf(p, "Upgrade: websocket\x0d\x0a"
 878                         "Connection: Upgrade\x0d\x0a"
 879                         "Sec-WebSocket-Key: ");
 880         strcpy(p, key_b64);
 881         p += strlen(key_b64);
 882         p += sprintf(p, "\x0d\x0a");
 883         if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN))
 884                 p += sprintf(p, "Origin: http://%s\x0d\x0a",
 885                              lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN));
 886
 887         if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS))
 888                 p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 889                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS));
 890
 891         /* tell the server what extensions we could support */
 892
 893         p += sprintf(p, "Sec-WebSocket-Extensions: ");
 894 #ifndef LWS_NO_EXTENSIONS
 895         ext = context->extensions;
 896         while (ext && ext->callback) {
 897
 898                 n = lws_ext_cb_all_exts(context, wsi,
 899                            LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
 900                            (char *)ext->name, 0);
 901                 if (n) { /* an extension vetos us */
 902                         lwsl_ext("ext %s vetoed\n", (char *)ext->name);
 903                         ext++;
 904                         continue;
 905                 }
 906
 907                 n = context->protocols[0].callback(wsi,
 908                         LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
 909                                 wsi->user_space, (char *)ext->name, 0);
 910
 911                 /*
 912                  * zero return from callback means
 913                  * go ahead and allow the extension,
 914                  * it's what we get if the callback is
 915                  * unhandled
 916                  */
 917
 918                 if (n) {
 919                         ext++;
 920                         continue;
 921                 }
 922
 923                 /* apply it */
 924
 925                 if (ext_count)
 926                         *p++ = ',';
 927                 p += sprintf(p, "%s", ext->name);
 928                 ext_count++;
 929
 930                 ext++;
 931         }
 932 #endif
 933         p += sprintf(p, "\x0d\x0a");
 934
 935         if (wsi->ietf_spec_revision)
 936                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
 937                              wsi->ietf_spec_revision);
 938
 939         /* give userland a chance to append, eg, cookies */
 940
 941         context->protocols[0].callback(wsi,
 942                                        LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
 943                                        NULL, &p,
 944                                        (pkt + sizeof(context->serv_buf)) - p - 12);
 945
 946         p += sprintf(p, "\x0d\x0a");
 947
 948         /* prepare the expected server accept response */
 949
 950         key_b64[39] = '\0'; /* enforce composed length below buf sizeof */
 951         n = sprintf(buf, "%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11", key_b64);
 952
 953         lws_SHA1((unsigned char *)buf, n, (unsigned char *)hash);
 954
 955         lws_b64_encode_string(hash, 20,
 956                               wsi->u.hdr.ah->initial_handshake_hash_base64,
 957                               sizeof(wsi->u.hdr.ah->initial_handshake_hash_base64));
 958
 959         return p;
 960 }
 961