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, LWS_MAX_SOCKET_IO_BUF, 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 #if defined(CYASSL_SNI_HOST_NAME) || defined(WOLFSSL_SNI_HOST_NAME) || defined(SSL_CTRL_SET_TLSEXT_HOSTNAME)
 153                         const char *hostname = lws_hdr_simple_ptr(wsi,
 154                                                 _WSI_TOKEN_CLIENT_HOST);
 155 #endif
 156
 157                         wsi->ssl = SSL_new(context->ssl_client_ctx);
 158 #ifndef USE_WOLFSSL
 159                         SSL_set_mode(wsi->ssl,
 160                                         SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
 161 #endif
 162                         /*
 163                          * use server name indication (SNI), if supported,
 164                          * when establishing connection
 165                          */
 166 #ifdef USE_WOLFSSL
 167 #ifdef USE_OLD_CYASSL
 168 #ifdef CYASSL_SNI_HOST_NAME
 169                         CyaSSL_UseSNI(wsi->ssl, CYASSL_SNI_HOST_NAME,
 170                                 hostname, strlen(hostname));
 171 #endif
 172 #else
 173 #ifdef WOLFSSL_SNI_HOST_NAME
 174                         wolfSSL_UseSNI(wsi->ssl, WOLFSSL_SNI_HOST_NAME,
 175                                 hostname, strlen(hostname));
 176 #endif
 177 #endif
 178 #else
 179 #ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
 180                         SSL_set_tlsext_host_name(wsi->ssl, hostname);
 181 #endif
 182 #endif
 183
 184 #ifdef USE_WOLFSSL
 185                         /*
 186                          * wolfSSL/CyaSSL does certificate verification differently
 187                          * from OpenSSL.
 188                          * If we should ignore the certificate, we need to set
 189                          * this before SSL_new and SSL_connect is called.
 190                          * Otherwise the connect will simply fail with error
 191                          * code -155
 192                          */
 193 #ifdef USE_OLD_CYASSL
 194                         if (wsi->use_ssl == 2)
 195                                 CyaSSL_set_verify(wsi->ssl,
 196                                                         SSL_VERIFY_NONE, NULL);
 197 #else
 198                         if (wsi->use_ssl == 2)
 199                                 wolfSSL_set_verify(wsi->ssl,
 200                                                         SSL_VERIFY_NONE, NULL);
 201 #endif
 202 #endif /* USE_WOLFSSL */
 203
 204                         wsi->client_bio =
 205                                 BIO_new_socket(wsi->sock, BIO_NOCLOSE);
 206                         SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio);
 207
 208 #ifdef USE_WOLFSSL
 209 #ifdef USE_OLD_CYASSL
 210                         CyaSSL_set_using_nonblock(wsi->ssl, 1);
 211 #else
 212                         wolfSSL_set_using_nonblock(wsi->ssl, 1);
 213 #endif
 214 #else
 215                         BIO_set_nbio(wsi->client_bio, 1); /* nonblocking */
 216 #endif
 217
 218                         SSL_set_ex_data(wsi->ssl,
 219                                         openssl_websocket_private_data_index,
 220                                                                        context);
 221                 }
 222
 223                 if (wsi->use_ssl) {
 224                         lws_latency_pre(context, wsi);
 225                         n = SSL_connect(wsi->ssl);
 226                         lws_latency(context, wsi,
 227                           "SSL_connect LWSCM_WSCL_ISSUE_HANDSHAKE", n, n > 0);
 228
 229                         if (n < 0) {
 230                                 n = SSL_get_error(wsi->ssl, n);
 231
 232                                 if (n == SSL_ERROR_WANT_READ)
 233                                         goto some_wait;
 234
 235                                 if (n == SSL_ERROR_WANT_WRITE) {
 236                                         /*
 237                                          * wants us to retry connect due to
 238                                          * state of the underlying ssl layer...
 239                                          * but since it may be stalled on
 240                                          * blocked write, no incoming data may
 241                                          * arrive to trigger the retry.
 242                                          * Force (possibly many times if the SSL
 243                                          * state persists in returning the
 244                                          * condition code, but other sockets
 245                                          * are getting serviced inbetweentimes)
 246                                          * us to get called back when writable.
 247                                          */
 248                                         lwsl_info("%s: WANT_WRITE... retrying\n", __func__);
 249                                         lws_callback_on_writable(wsi);
 250 some_wait:
 251                                         wsi->mode = LWSCM_WSCL_WAITING_SSL;
 252
 253                                         return 0; /* no error */
 254                                 }
 255                                 n = -1;
 256                         }
 257
 258                         if (n <= 0) {
 259                                 /*
 260                                  * retry if new data comes until we
 261                                  * run into the connection timeout or win
 262                                  */
 263                                 n = ERR_get_error();
 264                                 if (n != SSL_ERROR_NONE) {
 265                                         lwsl_err("SSL connect error %lu: %s\n",
 266                                                 n, ERR_error_string(n, sb));
 267                                         goto bail3;
 268                                 }
 269                         }
 270                 } else
 271                         wsi->ssl = NULL;
 272
 273                 /* fallthru */
 274
 275         case LWSCM_WSCL_WAITING_SSL:
 276
 277                 if (wsi->use_ssl) {
 278                         if (wsi->mode == LWSCM_WSCL_WAITING_SSL) {
 279                                 lws_latency_pre(context, wsi);
 280                                 n = SSL_connect(wsi->ssl);
 281                                 lws_latency(context, wsi,
 282                                             "SSL_connect LWSCM_WSCL_WAITING_SSL",
 283                                             n, n > 0);
 284
 285                                 if (n < 0) {
 286                                         n = SSL_get_error(wsi->ssl, n);
 287
 288                                         if (n == SSL_ERROR_WANT_READ)
 289                                                 goto some_wait;
 290
 291                                         if (n == SSL_ERROR_WANT_WRITE) {
 292                                                 /*
 293                                                  * wants us to retry connect due to
 294                                                  * state of the underlying ssl layer...
 295                                                  * but since it may be stalled on
 296                                                  * blocked write, no incoming data may
 297                                                  * arrive to trigger the retry.
 298                                                  * Force (possibly many times if the SSL
 299                                                  * state persists in returning the
 300                                                  * condition code, but other sockets
 301                                                  * are getting serviced inbetweentimes)
 302                                                  * us to get called back when writable.
 303                                                  */
 304                                                 lwsl_info("SSL_connect WANT_WRITE... retrying\n");
 305                                                 lws_callback_on_writable(wsi);
 306
 307                                                 goto some_wait;
 308                                         }
 309                                         n = -1;
 310                                 }
 311
 312                                 if (n <= 0) {
 313                                         /*
 314                                          * retry if new data comes until we
 315                                          * run into the connection timeout or win
 316                                          */
 317                                         n = ERR_get_error();
 318                                         if (n != SSL_ERROR_NONE) {
 319                                                 lwsl_err("SSL connect error %lu: %s\n",
 320                                                          n, ERR_error_string(n, sb));
 321                                                 goto bail3;
 322                                         }
 323                                 }
 324                         }
 325
 326                         #ifndef USE_WOLFSSL
 327                         /*
 328                          * See comment above about wolfSSL certificate
 329                          * verification
 330                          */
 331                         lws_latency_pre(context, wsi);
 332                         n = SSL_get_verify_result(wsi->ssl);
 333                         lws_latency(context, wsi,
 334                                 "SSL_get_verify_result LWS_CONNMODE..HANDSHAKE",
 335                                                                       n, n > 0);
 336
 337                         if (n != X509_V_OK) {
 338                                 if ((n == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT ||
 339                                      n == X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN) && wsi->use_ssl == 2) {
 340                                         lwsl_notice("accepting self-signed certificate\n");
 341                                 } else {
 342                                         lwsl_err("server's cert didn't look good, X509_V_ERR = %d: %s\n",
 343                                                  n, ERR_error_string(n, sb));
 344                                         lws_close_free_wsi(wsi,
 345                                                 LWS_CLOSE_STATUS_NOSTATUS);
 346                                         return -1;
 347                                 }
 348                         }
 349 #endif /* USE_WOLFSSL */
 350                 } else
 351                         wsi->ssl = NULL;
 352 #endif
 353
 354                 wsi->mode = LWSCM_WSCL_ISSUE_HANDSHAKE2;
 355                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_CLIENT_HS_SEND,
 356                                 context->timeout_secs);
 357
 358                 /* fallthru */
 359
 360         case LWSCM_WSCL_ISSUE_HANDSHAKE2:
 361                 p = lws_generate_client_handshake(wsi, p);
 362                 if (p == NULL) {
 363                         lwsl_err("Failed to generate handshake for client\n");
 364                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 365                         return 0;
 366                 }
 367
 368                 /* send our request to the server */
 369
 370                 lws_latency_pre(context, wsi);
 371
 372                 n = lws_ssl_capable_write(wsi, (unsigned char *)sb, p - sb);
 373                 lws_latency(context, wsi, "send lws_issue_raw", n,
 374                             n == p - sb);
 375                 switch (n) {
 376                 case LWS_SSL_CAPABLE_ERROR:
 377                         lwsl_debug("ERROR writing to client socket\n");
 378                         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 379                         return 0;
 380                 case LWS_SSL_CAPABLE_MORE_SERVICE:
 381                         lws_callback_on_writable(wsi);
 382                         break;
 383                 }
 384
 385                 wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 386                 wsi->u.hdr.lextable_pos = 0;
 387                 wsi->mode = LWSCM_WSCL_WAITING_SERVER_REPLY;
 388                 lws_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_SERVER_RESPONSE,
 389                                 context->timeout_secs);
 390                 break;
 391
 392         case LWSCM_WSCL_WAITING_SERVER_REPLY:
 393
 394                 /* handle server hung up on us */
 395
 396                 if (pollfd->revents & LWS_POLLHUP) {
 397
 398                         lwsl_debug("Server connection %p (fd=%d) dead\n",
 399                                 (void *)wsi, pollfd->fd);
 400
 401                         goto bail3;
 402                 }
 403
 404                 if (!(pollfd->revents & LWS_POLLIN))
 405                         break;
 406
 407                 /* interpret the server response */
 408
 409                 /*
 410                  *  HTTP/1.1 101 Switching Protocols
 411                  *  Upgrade: websocket
 412                  *  Connection: Upgrade
 413                  *  Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
 414                  *  Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
 415                  *  Sec-WebSocket-Protocol: chat
 416                  */
 417
 418                 /*
 419                  * we have to take some care here to only take from the
 420                  * socket bytewise.  The browser may (and has been seen to
 421                  * in the case that onopen() performs websocket traffic)
 422                  * coalesce both handshake response and websocket traffic
 423                  * in one packet, since at that point the connection is
 424                  * definitively ready from browser pov.
 425                  */
 426                 len = 1;
 427                 while (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE &&
 428                        len > 0) {
 429                         n = lws_ssl_capable_read(wsi, &c, 1);
 430                         lws_latency(context, wsi, "send lws_issue_raw", n,
 431                                     n == 1);
 432                         switch (n) {
 433                         case 0:
 434                         case LWS_SSL_CAPABLE_ERROR:
 435                                 goto bail3;
 436                         case LWS_SSL_CAPABLE_MORE_SERVICE:
 437                                 return 0;
 438                         }
 439
 440                         if (lws_parse(wsi, c)) {
 441                                 lwsl_warn("problems parsing header\n");
 442                                 goto bail3;
 443                         }
 444                 }
 445
 446                 /*
 447                  * hs may also be coming in multiple packets, there is a 5-sec
 448                  * libwebsocket timeout still active here too, so if parsing did
 449                  * not complete just wait for next packet coming in this state
 450                  */
 451
 452                 if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
 453                         break;
 454
 455                 /*
 456                  * otherwise deal with the handshake.  If there's any
 457                  * packet traffic already arrived we'll trigger poll() again
 458                  * right away and deal with it that way
 459                  */
 460
 461                 return lws_client_interpret_server_handshake(wsi);
 462
 463 bail3:
 464                 lwsl_info("closing conn at LWS_CONNMODE...SERVER_REPLY\n");
 465                 wsi->context->protocols[0].callback(wsi,
 466                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 467                                 wsi->user_space, NULL, 0);
 468
 469                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 470                 return -1;
 471
 472         case LWSCM_WSCL_WAITING_EXTENSION_CONNECT:
 473                 lwsl_ext("LWSCM_WSCL_WAITING_EXTENSION_CONNECT\n");
 474                 break;
 475
 476         case LWSCM_WSCL_PENDING_CANDIDATE_CHILD:
 477                 lwsl_ext("LWSCM_WSCL_PENDING_CANDIDATE_CHILD\n");
 478                 break;
 479         default:
 480                 break;
 481         }
 482
 483         return 0;
 484 }
 485
 486 /*
 487  * In-place str to lower case
 488  */
 489
 490 static void
 491 strtolower(char *s)
 492 {
 493         while (*s) {
 494                 *s = tolower((int)*s);
 495                 s++;
 496         }
 497 }
 498
 499 int
 500 lws_client_interpret_server_handshake(struct lws *wsi)
 501 {
 502         int n, len, okay = 0, isErrorCodeReceived = 0, port = 0, ssl = 0;
 503         struct lws_context *context = wsi->context;
 504         int close_reason = LWS_CLOSE_STATUS_PROTOCOL_ERR;
 505         const char *pc, *prot, *ads = NULL, *path;
 506         char *p;
 507 #ifndef LWS_NO_EXTENSIONS
 508         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 509         char *sb = (char *)&pt->serv_buf[0];
 510         const struct lws_ext_options *opts;
 511         const struct lws_extension *ext;
 512         char ext_name[128];
 513         const char *c, *a;
 514         char ignore;
 515         int more = 1;
 516         void *v;
 517 #endif
 518
 519         /*
 520          * well, what the server sent looked reasonable for syntax.
 521          * Now let's confirm it sent all the necessary headers
 522          */
 523         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP);
 524         if (!p) {
 525                 lwsl_info("no URI\n");
 526                 goto bail3;
 527         }
 528         n = atoi(p);
 529         if (n == 301 || n == 302 || n == 303 || n == 307 || n == 308) {
 530                 p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_HTTP_LOCATION);
 531                 if (!p)
 532                         goto bail3;
 533
 534                 if (lws_parse_uri(p, &prot, &ads, &port, &path))
 535                         goto bail3;
 536
 537                 if (!strcmp(prot, "wss://") || !strcmp(prot, "https://"))
 538                         ssl = 1;
 539
 540                 if (lws_client_reset(wsi, ssl, ads, port, path, ads)) {
 541                         lwsl_err("Redirect failed\n");
 542                         goto bail3;
 543                 }
 544                 return 0;
 545         }
 546         if (lws_hdr_total_length(wsi, WSI_TOKEN_ACCEPT) == 0) {
 547                 lwsl_info("no ACCEPT\n");
 548                 isErrorCodeReceived = 1;
 549                 goto bail3;
 550         }
 551
 552         if (p && strncmp(p, "101", 3)) {
 553                 lwsl_warn(
 554                        "lws_client_handshake: got bad HTTP response '%s'\n", p);
 555                 goto bail3;
 556         }
 557
 558         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_UPGRADE);
 559         if (!p) {
 560                 lwsl_info("no UPGRADE\n");
 561                 goto bail3;
 562         }
 563         strtolower(p);
 564         if (strcmp(p, "websocket")) {
 565                 lwsl_warn(
 566                       "lws_client_handshake: got bad Upgrade header '%s'\n", p);
 567                 goto bail3;
 568         }
 569
 570         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_CONNECTION);
 571         if (!p) {
 572                 lwsl_info("no Connection hdr\n");
 573                 goto bail3;
 574         }
 575         strtolower(p);
 576         if (strcmp(p, "upgrade")) {
 577                 lwsl_warn("lws_client_int_s_hs: bad header %s\n", p);
 578                 goto bail3;
 579         }
 580
 581         pc = lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS);
 582         if (!pc) {
 583                 lwsl_parser("lws_client_int_s_hs: no protocol list\n");
 584         } else
 585                 lwsl_parser("lws_client_int_s_hs: protocol list '%s'\n", pc);
 586
 587         /*
 588          * confirm the protocol the server wants to talk was in the list
 589          * of protocols we offered
 590          */
 591
 592         len = lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL);
 593         if (!len) {
 594                 lwsl_info("lws_client_int_s_hs: WSI_TOKEN_PROTOCOL is null\n");
 595                 /*
 596                  * no protocol name to work from,
 597                  * default to first protocol
 598                  */
 599                 wsi->protocol = &context->protocols[0];
 600                 goto check_extensions;
 601         }
 602
 603         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL);
 604         len = strlen(p);
 605
 606         while (pc && *pc && !okay) {
 607                 if (!strncmp(pc, p, len) &&
 608                     (pc[len] == ',' || pc[len] == '\0')) {
 609                         okay = 1;
 610                         continue;
 611                 }
 612                 while (*pc && *pc++ != ',')
 613                         ;
 614                 while (*pc && *pc == ' ')
 615                         pc++;
 616         }
 617
 618         if (!okay) {
 619                 lwsl_err("lws_client_int_s_hs: got bad protocol %s\n", p);
 620                 goto bail2;
 621         }
 622
 623         /*
 624          * identify the selected protocol struct and set it
 625          */
 626         n = 0;
 627         wsi->protocol = NULL;
 628         while (context->protocols[n].callback && !wsi->protocol) {
 629                 if (strcmp(p, context->protocols[n].name) == 0) {
 630                         wsi->protocol = &context->protocols[n];
 631                         break;
 632                 }
 633                 n++;
 634         }
 635
 636         if (wsi->protocol == NULL) {
 637                 lwsl_err("lws_client_int_s_hs: fail protocol %s\n", p);
 638                 goto bail2;
 639         }
 640
 641
 642 check_extensions:
 643 #ifndef LWS_NO_EXTENSIONS
 644         /* instantiate the accepted extensions */
 645
 646         if (!lws_hdr_total_length(wsi, WSI_TOKEN_EXTENSIONS)) {
 647                 lwsl_ext("no client extensions allowed by server\n");
 648                 goto check_accept;
 649         }
 650
 651         /*
 652          * break down the list of server accepted extensions
 653          * and go through matching them or identifying bogons
 654          */
 655
 656         if (lws_hdr_copy(wsi, sb, LWS_MAX_SOCKET_IO_BUF, WSI_TOKEN_EXTENSIONS) < 0) {
 657                 lwsl_warn("ext list from server failed to copy\n");
 658                 goto bail2;
 659         }
 660
 661         c = sb;
 662         n = 0;
 663         ignore = 0;
 664         a = NULL;
 665         while (more) {
 666
 667                 if (*c && (*c != ',' && *c != '\t')) {
 668                         if (*c == ';') {
 669                                 ignore = 1;
 670                                 if (!a)
 671                                         a = c + 1;
 672                         }
 673                         if (ignore || *c == ' ') {
 674                                 c++;
 675                                 continue;
 676                         }
 677
 678                         ext_name[n] = *c++;
 679                         if (n < sizeof(ext_name) - 1)
 680                                 n++;
 681                         continue;
 682                 }
 683                 ext_name[n] = '\0';
 684                 ignore = 0;
 685                 if (!*c)
 686                         more = 0;
 687                 else {
 688                         c++;
 689                         if (!n)
 690                                 continue;
 691                 }
 692
 693                 /* check we actually support it */
 694
 695                 lwsl_notice("checking client ext %s\n", ext_name);
 696
 697                 n = 0;
 698                 ext = lws_get_context(wsi)->extensions;
 699                 while (ext && ext->callback) {
 700                         if (strcmp(ext_name, ext->name)) {
 701                                 ext++;
 702                                 continue;
 703                         }
 704
 705                         n = 1;
 706                         lwsl_notice("instantiating client ext %s\n", ext_name);
 707
 708                         /* instantiate the extension on this conn */
 709
 710                         wsi->active_extensions[wsi->count_act_ext] = ext;
 711
 712                         /* allow him to construct his ext instance */
 713
 714                         if (ext->callback(lws_get_context(wsi), ext, wsi,
 715                                       LWS_EXT_CB_CLIENT_CONSTRUCT,
 716                                       (void *)&wsi->act_ext_user[wsi->count_act_ext],
 717                                       (void *)&opts, 0)) {
 718                                 lwsl_notice(" ext %s failed construction\n", ext_name);
 719                                 ext++;
 720                                 continue;
 721                         }
 722
 723                         /*
 724                          * allow the user code to override ext defaults if it
 725                          * wants to
 726                          */
 727                         ext_name[0] = '\0';
 728                         if (user_callback_handle_rxflow(wsi->protocol->callback,
 729                                         wsi, LWS_CALLBACK_WS_EXT_DEFAULTS,
 730                                         (char *)ext->name, ext_name,
 731                                         sizeof(ext_name)))
 732                                 goto bail2;
 733
 734                         if (ext_name[0] &&
 735                             lws_ext_parse_options(ext, wsi, wsi->act_ext_user[
 736                                                   wsi->count_act_ext], opts, ext_name,
 737                                                   strlen(ext_name))) {
 738                                 lwsl_err("%s: unable to parse user defaults '%s'",
 739                                          __func__, ext_name);
 740                                 goto bail2;
 741                         }
 742
 743                         /*
 744                          * give the extension the server options
 745                          */
 746                         if (a && lws_ext_parse_options(ext, wsi,
 747                                         wsi->act_ext_user[wsi->count_act_ext],
 748                                         opts, a, c - a)) {
 749                                 lwsl_err("%s: unable to parse remote def '%s'",
 750                                          __func__, a);
 751                                 goto bail2;
 752                         }
 753
 754                         if (ext->callback(lws_get_context(wsi), ext, wsi,
 755                                         LWS_EXT_CB_OPTION_CONFIRM,
 756                                       wsi->act_ext_user[wsi->count_act_ext],
 757                                       NULL, 0)) {
 758                                 lwsl_err("%s: ext %s rejects server options %s",
 759                                          ext->name, a);
 760                                 goto bail2;
 761                         }
 762
 763                         wsi->count_act_ext++;
 764
 765                         ext++;
 766                 }
 767
 768                 if (n == 0) {
 769                         lwsl_warn("Unknown ext '%s'!\n", ext_name);
 770                         goto bail2;
 771                 }
 772
 773                 a = NULL;
 774                 n = 0;
 775         }
 776
 777 check_accept:
 778 #endif
 779
 780         /*
 781          * Confirm his accept token is the one we precomputed
 782          */
 783
 784         p = lws_hdr_simple_ptr(wsi, WSI_TOKEN_ACCEPT);
 785         if (strcmp(p, wsi->u.hdr.ah->initial_handshake_hash_base64)) {
 786                 lwsl_warn("lws_client_int_s_hs: accept '%s' wrong vs '%s'\n", p,
 787                                   wsi->u.hdr.ah->initial_handshake_hash_base64);
 788                 goto bail2;
 789         }
 790
 791         /* allocate the per-connection user memory (if any) */
 792         if (lws_ensure_user_space(wsi)) {
 793                 lwsl_err("Problem allocating wsi user mem\n");
 794                 goto bail2;
 795         }
 796
 797         /*
 798          * we seem to be good to go, give client last chance to check
 799          * headers and OK it
 800          */
 801         if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH,
 802                                     wsi->user_space, NULL, 0))
 803                 goto bail2;
 804
 805         /* clear his proxy connection timeout */
 806         lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
 807
 808         /* free up his parsing allocations */
 809         lws_header_table_detach(wsi);
 810
 811         lws_union_transition(wsi, LWSCM_WS_CLIENT);
 812         wsi->state = LWSS_ESTABLISHED;
 813
 814         wsi->rxflow_change_to = LWS_RXFLOW_ALLOW;
 815
 816         /*
 817          * create the frame buffer for this connection according to the
 818          * size mentioned in the protocol definition.  If 0 there, then
 819          * use a big default for compatibility
 820          */
 821         n = wsi->protocol->rx_buffer_size;
 822         if (!n)
 823                 n = LWS_MAX_SOCKET_IO_BUF;
 824         n += LWS_PRE;
 825         wsi->u.ws.rx_ubuf = lws_malloc(n + 4 /* 0x0000ffff zlib */);
 826         if (!wsi->u.ws.rx_ubuf) {
 827                 lwsl_err("Out of Mem allocating rx buffer %d\n", n);
 828                 goto bail2;
 829         }
 830        wsi->u.ws.rx_ubuf_alloc = n;
 831         lwsl_info("Allocating client RX buffer %d\n", n);
 832
 833         if (setsockopt(wsi->sock, SOL_SOCKET, SO_SNDBUF, (const char *)&n,
 834                        sizeof n)) {
 835                 lwsl_warn("Failed to set SNDBUF to %d", n);
 836                 goto bail3;
 837         }
 838
 839         lwsl_debug("handshake OK for protocol %s\n", wsi->protocol->name);
 840
 841         /* call him back to inform him he is up */
 842
 843         if (wsi->protocol->callback(wsi, LWS_CALLBACK_CLIENT_ESTABLISHED,
 844                                     wsi->user_space, NULL, 0))
 845                 goto bail3;
 846 #ifndef LWS_NO_EXTENSIONS
 847         /*
 848          * inform all extensions, not just active ones since they
 849          * already know
 850          */
 851         ext = context->extensions;
 852
 853         while (ext && ext->callback) {
 854                 v = NULL;
 855                 for (n = 0; n < wsi->count_act_ext; n++)
 856                         if (wsi->active_extensions[n] == ext)
 857                                 v = wsi->act_ext_user[n];
 858
 859                 ext->callback(context, ext, wsi,
 860                           LWS_EXT_CB_ANY_WSI_ESTABLISHED, v, NULL, 0);
 861                 ext++;
 862         }
 863 #endif
 864
 865         return 0;
 866
 867 bail3:
 868         close_reason = LWS_CLOSE_STATUS_NOSTATUS;
 869
 870 bail2:
 871         if (wsi->protocol && wsi->state == LWSS_ESTABLISHED) {
 872                 if (isErrorCodeReceived && p) {
 873                         wsi->protocol->callback(wsi,
 874                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 875                                                 wsi->user_space, p,
 876                                                 (unsigned int)strlen(p));
 877                 } else {
 878                         wsi->protocol->callback(wsi,
 879                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 880                                                 wsi->user_space, NULL, 0);
 881                 }
 882         }
 883
 884         lwsl_info("closing connection due to bail2 connection error\n");
 885
 886         /* closing will free up his parsing allocations */
 887         lws_close_free_wsi(wsi, close_reason);
 888
 889         return 1;
 890 }
 891
 892
 893 char *
 894 lws_generate_client_handshake(struct lws *wsi, char *pkt)
 895 {
 896         char buf[128], hash[20], key_b64[40], *p = pkt;
 897         struct lws_context *context = wsi->context;
 898         int n;
 899 #ifndef LWS_NO_EXTENSIONS
 900         const struct lws_extension *ext;
 901         int ext_count = 0;
 902 #endif
 903
 904         /*
 905          * create the random key
 906          */
 907         n = lws_get_random(context, hash, 16);
 908         if (n != 16) {
 909                 lwsl_err("Unable to read from random dev %s\n",
 910                          SYSTEM_RANDOM_FILEPATH);
 911                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 912                 return NULL;
 913         }
 914
 915         lws_b64_encode_string(hash, 16, key_b64, sizeof(key_b64));
 916
 917         /*
 918          * 00 example client handshake
 919          *
 920          * GET /socket.io/websocket HTTP/1.1
 921          * Upgrade: WebSocket
 922          * Connection: Upgrade
 923          * Host: 127.0.0.1:9999
 924          * Origin: http://127.0.0.1
 925          * Sec-WebSocket-Key1: 1 0 2#0W 9 89 7  92 ^
 926          * Sec-WebSocket-Key2: 7 7Y 4328 B2v[8(z1
 927          * Cookie: socketio=websocket
 928          *
 929          * (Á®Ä0¶†≥
 930          *
 931          * 04 example client handshake
 932          *
 933          * GET /chat HTTP/1.1
 934          * Host: server.example.com
 935          * Upgrade: websocket
 936          * Connection: Upgrade
 937          * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
 938          * Sec-WebSocket-Origin: http://example.com
 939          * Sec-WebSocket-Protocol: chat, superchat
 940          * Sec-WebSocket-Version: 4
 941          */
 942
 943         p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a",
 944                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_URI));
 945
 946         p += sprintf(p, "Pragma: no-cache\x0d\x0a"
 947                         "Cache-Control: no-cache\x0d\x0a");
 948
 949         p += sprintf(p, "Host: %s\x0d\x0a",
 950                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_HOST));
 951         p += sprintf(p, "Upgrade: websocket\x0d\x0a"
 952                         "Connection: Upgrade\x0d\x0a"
 953                         "Sec-WebSocket-Key: ");
 954         strcpy(p, key_b64);
 955         p += strlen(key_b64);
 956         p += sprintf(p, "\x0d\x0a");
 957         if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN))
 958                 p += sprintf(p, "Origin: http://%s\x0d\x0a",
 959                              lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_ORIGIN));
 960
 961         if (lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS))
 962                 p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a",
 963                      lws_hdr_simple_ptr(wsi, _WSI_TOKEN_CLIENT_SENT_PROTOCOLS));
 964
 965         /* tell the server what extensions we could support */
 966
 967 #ifndef LWS_NO_EXTENSIONS
 968         ext = context->extensions;
 969         while (ext && ext->callback) {
 970                 n = lws_ext_cb_all_exts(context, wsi,
 971                            LWS_EXT_CB_CHECK_OK_TO_PROPOSE_EXTENSION,
 972                            (char *)ext->name, 0);
 973                 if (n) { /* an extension vetos us */
 974                         lwsl_ext("ext %s vetoed\n", (char *)ext->name);
 975                         ext++;
 976                         continue;
 977                 }
 978                 n = context->protocols[0].callback(wsi,
 979                         LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
 980                                 wsi->user_space, (char *)ext->name, 0);
 981
 982                 /*
 983                  * zero return from callback means
 984                  * go ahead and allow the extension,
 985                  * it's what we get if the callback is
 986                  * unhandled
 987                  */
 988
 989                 if (n) {
 990                         ext++;
 991                         continue;
 992                 }
 993
 994                 /* apply it */
 995
 996                 if (ext_count)
 997                         *p++ = ',';
 998                 else
 999                         p += sprintf(p, "Sec-WebSocket-Extensions: ");
1000
1001                 p += sprintf(p, "%s", ext->client_offer);
1002                 ext_count++;
1003
1004                 ext++;
1005         }
1006         if (ext_count)
1007                 p += sprintf(p, "\x0d\x0a");
1008 #endif
1009
1010         if (wsi->ietf_spec_revision)
1011                 p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a",
1012                              wsi->ietf_spec_revision);
1013
1014         /* give userland a chance to append, eg, cookies */
1015
1016         context->protocols[0].callback(wsi, LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
1017                                 wsi->user_space, &p, (pkt + LWS_MAX_SOCKET_IO_BUF) - p - 12);
1018
1019         p += sprintf(p, "\x0d\x0a");
1020
1021         /* prepare the expected server accept response */
1022
1023         key_b64[39] = '\0'; /* enforce composed length below buf sizeof */
1024         n = sprintf(buf, "%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11", key_b64);
1025
1026         lws_SHA1((unsigned char *)buf, n, (unsigned char *)hash);
1027
1028         lws_b64_encode_string(hash, 20,
1029                               wsi->u.hdr.ah->initial_handshake_hash_base64,
1030                               sizeof(wsi->u.hdr.ah->initial_handshake_hash_base64));
1031
1032         return p;
1033 }
1034