lib/parsers.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2013 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 const unsigned char lextable[] = {
  25         #include "lextable.h"
  26 };
  27
  28 #define FAIL_CHAR 0x08
  29
  30 int LWS_WARN_UNUSED_RESULT
  31 lextable_decode(int pos, char c)
  32 {
  33         if (c >= 'A' && c <= 'Z')
  34                 c += 'a' - 'A';
  35
  36         while (1) {
  37                 if (lextable[pos] & (1 << 7)) { /* 1-byte, fail on mismatch */
  38                         if ((lextable[pos] & 0x7f) != c)
  39                                 return -1;
  40                         /* fall thru */
  41                         pos++;
  42                         if (lextable[pos] == FAIL_CHAR)
  43                                 return -1;
  44                         return pos;
  45                 }
  46
  47                 if (lextable[pos] == FAIL_CHAR)
  48                         return -1;
  49
  50                 /* b7 = 0, end or 3-byte */
  51                 if (lextable[pos] < FAIL_CHAR) /* terminal marker */
  52                         return pos;
  53
  54                 if (lextable[pos] == c) /* goto */
  55                         return pos + (lextable[pos + 1]) +
  56                                                 (lextable[pos + 2] << 8);
  57                 /* fall thru goto */
  58                 pos += 3;
  59                 /* continue */
  60         }
  61 }
  62
  63 void
  64 _lws_header_table_reset(struct allocated_headers *ah)
  65 {
  66         /* init the ah to reflect no headers or data have appeared yet */
  67         memset(ah->frag_index, 0, sizeof(ah->frag_index));
  68         ah->nfrag = 0;
  69         ah->pos = 0;
  70         ah->http_response = 0;
  71 }
  72
  73 // doesn't scrub the ah rxbuffer by default, parent must do if needed
  74
  75 void
  76 lws_header_table_reset(struct lws *wsi, int autoservice)
  77 {
  78         struct allocated_headers *ah = wsi->u.hdr.ah;
  79         struct lws_context_per_thread *pt;
  80         struct lws_pollfd *pfd;
  81
  82         /* if we have the idea we're resetting 'our' ah, must be bound to one */
  83         assert(ah);
  84         /* ah also concurs with ownership */
  85         assert(ah->wsi == wsi);
  86
  87         _lws_header_table_reset(ah);
  88
  89         /* since we will restart the ah, our new headers are not completed */
  90         // wsi->hdr_parsing_completed = 0;
  91
  92         /*
  93          * if we inherited pending rx (from socket adoption deferred
  94          * processing), apply and free it.
  95          */
  96         if (wsi->u.hdr.preamble_rx) {
  97                 memcpy(ah->rx, wsi->u.hdr.preamble_rx,
  98                        wsi->u.hdr.preamble_rx_len);
  99                 ah->rxlen = wsi->u.hdr.preamble_rx_len;
 100                 lws_free_set_NULL(wsi->u.hdr.preamble_rx);
 101
 102                 if (autoservice) {
 103                         lwsl_notice("%s: calling service on readbuf ah\n", __func__);
 104
 105                         pt = &wsi->context->pt[(int)wsi->tsi];
 106
 107                         /* unlike a normal connect, we have the headers already
 108                          * (or the first part of them anyway)
 109                          */
 110                         pfd = &pt->fds[wsi->position_in_fds_table];
 111                         pfd->revents |= LWS_POLLIN;
 112                         lwsl_err("%s: calling service\n", __func__);
 113                         lws_service_fd_tsi(wsi->context, pfd, wsi->tsi);
 114                 }
 115         }
 116 }
 117
 118 int LWS_WARN_UNUSED_RESULT
 119 lws_header_table_attach(struct lws *wsi, int autoservice)
 120 {
 121         struct lws_context *context = wsi->context;
 122         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 123         struct lws_pollargs pa;
 124         struct lws **pwsi;
 125         int n;
 126
 127         lwsl_info("%s: wsi %p: ah %p (tsi %d, count = %d) in\n", __func__, (void *)wsi,
 128                  (void *)wsi->u.hdr.ah, wsi->tsi, pt->ah_count_in_use);
 129
 130         /* if we are already bound to one, just clear it down */
 131         if (wsi->u.hdr.ah) {
 132                 lwsl_info("cleardown\n");
 133                 goto reset;
 134         }
 135
 136         lws_pt_lock(pt);
 137         pwsi = &pt->ah_wait_list;
 138         while (*pwsi) {
 139                 if (*pwsi == wsi) {
 140                         /* if already waiting on list, if no new ah just ret */
 141                         if (pt->ah_count_in_use ==
 142                             context->max_http_header_pool) {
 143                                 lwsl_notice("%s: no free ah to attach\n", __func__);
 144                                 goto bail;
 145                         }
 146                         /* new ah.... remove ourselves from waiting list */
 147                         *pwsi = wsi->u.hdr.ah_wait_list; /* set our prev to our next */
 148                         wsi->u.hdr.ah_wait_list = NULL; /* no next any more */
 149                         pt->ah_wait_list_length--;
 150                         break;
 151                 }
 152                 pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 153         }
 154         /*
 155          * pool is all busy... add us to waiting list and return that we
 156          * weren't able to deliver it right now
 157          */
 158         if (pt->ah_count_in_use == context->max_http_header_pool) {
 159                 lwsl_info("%s: adding %p to ah waiting list\n", __func__, wsi);
 160                 wsi->u.hdr.ah_wait_list = pt->ah_wait_list;
 161                 pt->ah_wait_list = wsi;
 162                 pt->ah_wait_list_length++;
 163
 164                 /* we cannot accept input then */
 165
 166                 _lws_change_pollfd(wsi, LWS_POLLIN, 0, &pa);
 167                 goto bail;
 168         }
 169
 170         for (n = 0; n < context->max_http_header_pool; n++)
 171                 if (!pt->ah_pool[n].in_use)
 172                         break;
 173
 174         /* if the count of in use said something free... */
 175         assert(n != context->max_http_header_pool);
 176
 177         wsi->u.hdr.ah = &pt->ah_pool[n];
 178         wsi->u.hdr.ah->in_use = 1;
 179         pt->ah_pool[n].wsi = wsi; /* mark our owner */
 180         pt->ah_count_in_use++;
 181
 182         _lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
 183
 184         lwsl_info("%s: did attach wsi %p: ah %p: count %d (on exit)\n", __func__,
 185                   (void *)wsi, (void *)wsi->u.hdr.ah, pt->ah_count_in_use);
 186
 187         lws_pt_unlock(pt);
 188
 189 reset:
 190
 191         /* and reset the rx state */
 192         wsi->u.hdr.ah->rxpos = 0;
 193         wsi->u.hdr.ah->rxlen = 0;
 194
 195         lws_header_table_reset(wsi, autoservice);
 196         time(&wsi->u.hdr.ah->assigned);
 197
 198 #ifndef LWS_NO_CLIENT
 199         if (wsi->state == LWSS_CLIENT_UNCONNECTED)
 200                 if (!lws_client_connect_via_info2(wsi))
 201                         /* our client connect has failed, the wsi
 202                          * has been closed
 203                          */
 204                         return -1;
 205 #endif
 206
 207         return 0;
 208
 209 bail:
 210         lws_pt_unlock(pt);
 211
 212         return 1;
 213 }
 214
 215 int lws_header_table_detach(struct lws *wsi, int autoservice)
 216 {
 217         struct lws_context *context = wsi->context;
 218         struct allocated_headers *ah = wsi->u.hdr.ah;
 219         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 220         struct lws_pollargs pa;
 221         struct lws **pwsi;
 222         time_t now;
 223
 224         lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
 225                   (void *)wsi, (void *)ah, wsi->tsi,
 226                   pt->ah_count_in_use);
 227
 228         if (wsi->u.hdr.preamble_rx)
 229                 lws_free_set_NULL(wsi->u.hdr.preamble_rx);
 230
 231         /* may not be detached while he still has unprocessed rx */
 232         if (ah && ah->rxpos != ah->rxlen) {
 233                 lwsl_err("%s: %p: CANNOT DETACH rxpos:%d, rxlen:%d\n", __func__, wsi,
 234                                 ah->rxpos, ah->rxlen);
 235                 assert(ah->rxpos == ah->rxlen);
 236
 237                 return 0;
 238         }
 239
 240         lws_pt_lock(pt);
 241
 242         pwsi = &pt->ah_wait_list;
 243         if (!ah) { /* remove from wait list if none attached */
 244                 while (*pwsi) {
 245                         if (*pwsi == wsi) {
 246                                 lwsl_info("%s: wsi %p, remv wait\n",
 247                                           __func__, wsi);
 248                                 *pwsi = wsi->u.hdr.ah_wait_list;
 249                                 wsi->u.hdr.ah_wait_list = NULL;
 250                                 pt->ah_wait_list_length--;
 251                                 goto bail;
 252                         }
 253                         pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 254                 }
 255                 /* no ah, not on list... no more business here */
 256                 goto bail;
 257         }
 258         /* we did have an ah attached */
 259         time(&now);
 260         if (ah->assigned && now - ah->assigned > 3) {
 261                 /*
 262                  * we're detaching the ah, but it was held an
 263                  * unreasonably long time
 264                  */
 265                 lwsl_notice("%s: wsi %p: ah held %ds, "
 266                             "ah.rxpos %d, ah.rxlen %d, mode/state %d %d,"
 267                             "wsi->more_rx_waiting %d\n", __func__, wsi,
 268                             (int)(now - ah->assigned),
 269                             ah->rxpos, ah->rxlen, wsi->mode, wsi->state,
 270                             wsi->more_rx_waiting);
 271         }
 272
 273         ah->assigned = 0;
 274
 275         /* if we think we're detaching one, there should be one in use */
 276         assert(pt->ah_count_in_use > 0);
 277         /* and this specific one should have been in use */
 278         assert(ah->in_use);
 279         wsi->u.hdr.ah = NULL;
 280         ah->wsi = NULL; /* no owner */
 281
 282         /* oh there is nobody on the waiting list... leave it at that then */
 283         if (!*pwsi) {
 284                 ah->in_use = 0;
 285                 pt->ah_count_in_use--;
 286
 287                 goto bail;
 288         }
 289
 290         /* somebody else on same tsi is waiting, give it to oldest guy */
 291
 292         lwsl_info("pt wait list %p\n", *pwsi);
 293         while ((*pwsi)->u.hdr.ah_wait_list)
 294                 pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 295
 296         wsi = *pwsi;
 297         lwsl_info("last wsi in wait list %p\n", wsi);
 298
 299         wsi->u.hdr.ah = ah;
 300         ah->wsi = wsi; /* new owner */
 301         /* and reset the rx state */
 302         ah->rxpos = 0;
 303         ah->rxlen = 0;
 304         lws_header_table_reset(wsi, autoservice);
 305         time(&wsi->u.hdr.ah->assigned);
 306
 307         /* clients acquire the ah and then insert themselves in fds table... */
 308         if (wsi->position_in_fds_table != -1) {
 309                 lwsl_info("%s: Enabling %p POLLIN\n", __func__, wsi);
 310
 311                 /* he has been stuck waiting for an ah, but now his wait is over,
 312                  * let him progress
 313                  */
 314                 _lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
 315         }
 316
 317         /* point prev guy to next guy in list instead */
 318         *pwsi = wsi->u.hdr.ah_wait_list;
 319         /* the guy who got one is out of the list */
 320         wsi->u.hdr.ah_wait_list = NULL;
 321         pt->ah_wait_list_length--;
 322
 323 #ifndef LWS_NO_CLIENT
 324         if (wsi->state == LWSS_CLIENT_UNCONNECTED)
 325                 if (!lws_client_connect_via_info2(wsi)) {
 326                         /* our client connect has failed, the wsi
 327                          * has been closed
 328                          */
 329                         lws_pt_unlock(pt);
 330
 331                         return -1;
 332                 }
 333 #endif
 334
 335         assert(!!pt->ah_wait_list_length == !!(int)(long)pt->ah_wait_list);
 336 bail:
 337         lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
 338           (void *)wsi, (void *)ah, wsi->tsi,
 339           pt->ah_count_in_use);
 340         lws_pt_unlock(pt);
 341
 342         return 0;
 343 }
 344
 345 LWS_VISIBLE int
 346 lws_hdr_fragment_length(struct lws *wsi, enum lws_token_indexes h, int frag_idx)
 347 {
 348         int n;
 349
 350         n = wsi->u.hdr.ah->frag_index[h];
 351         if (!n)
 352                 return 0;
 353         do {
 354                 if (!frag_idx)
 355                         return wsi->u.hdr.ah->frags[n].len;
 356                 n = wsi->u.hdr.ah->frags[n].nfrag;
 357         } while (frag_idx-- && n);
 358
 359         return 0;
 360 }
 361
 362 LWS_VISIBLE int lws_hdr_total_length(struct lws *wsi, enum lws_token_indexes h)
 363 {
 364         int n;
 365         int len = 0;
 366
 367         n = wsi->u.hdr.ah->frag_index[h];
 368         if (!n)
 369                 return 0;
 370         do {
 371                 len += wsi->u.hdr.ah->frags[n].len;
 372                 n = wsi->u.hdr.ah->frags[n].nfrag;
 373         } while (n);
 374
 375         return len;
 376 }
 377
 378 LWS_VISIBLE int lws_hdr_copy_fragment(struct lws *wsi, char *dst, int len,
 379                                       enum lws_token_indexes h, int frag_idx)
 380 {
 381         int n = 0;
 382         int f = wsi->u.hdr.ah->frag_index[h];
 383
 384         if (!f)
 385                 return -1;
 386
 387         while (n < frag_idx) {
 388                 f = wsi->u.hdr.ah->frags[f].nfrag;
 389                 if (!f)
 390                         return -1;
 391                 n++;
 392         }
 393
 394         if (wsi->u.hdr.ah->frags[f].len >= len)
 395                 return -1;
 396
 397         memcpy(dst, wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[f].offset,
 398                wsi->u.hdr.ah->frags[f].len);
 399         dst[wsi->u.hdr.ah->frags[f].len] = '\0';
 400
 401         return wsi->u.hdr.ah->frags[f].len;
 402 }
 403
 404 LWS_VISIBLE int lws_hdr_copy(struct lws *wsi, char *dst, int len,
 405                              enum lws_token_indexes h)
 406 {
 407         int toklen = lws_hdr_total_length(wsi, h);
 408         int n;
 409
 410         if (toklen >= len)
 411                 return -1;
 412
 413         n = wsi->u.hdr.ah->frag_index[h];
 414         if (!n)
 415                 return 0;
 416
 417         do {
 418                 strcpy(dst, &wsi->u.hdr.ah->data[wsi->u.hdr.ah->frags[n].offset]);
 419                 dst += wsi->u.hdr.ah->frags[n].len;
 420                 n = wsi->u.hdr.ah->frags[n].nfrag;
 421         } while (n);
 422
 423         return toklen;
 424 }
 425
 426 char *lws_hdr_simple_ptr(struct lws *wsi, enum lws_token_indexes h)
 427 {
 428         int n;
 429
 430         n = wsi->u.hdr.ah->frag_index[h];
 431         if (!n)
 432                 return NULL;
 433
 434         return wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[n].offset;
 435 }
 436
 437 int LWS_WARN_UNUSED_RESULT
 438 lws_pos_in_bounds(struct lws *wsi)
 439 {
 440         if (wsi->u.hdr.ah->pos < (unsigned int)wsi->context->max_http_header_data)
 441                 return 0;
 442
 443         if (wsi->u.hdr.ah->pos == wsi->context->max_http_header_data) {
 444                 lwsl_err("Ran out of header data space\n");
 445                 return 1;
 446         }
 447
 448         /*
 449          * with these tests everywhere, it should never be able to exceed
 450          * the limit, only meet the limit
 451          */
 452
 453         lwsl_err("%s: pos %d, limit %d\n", __func__, wsi->u.hdr.ah->pos,
 454                  wsi->context->max_http_header_data);
 455         assert(0);
 456
 457         return 1;
 458 }
 459
 460 int LWS_WARN_UNUSED_RESULT
 461 lws_hdr_simple_create(struct lws *wsi, enum lws_token_indexes h, const char *s)
 462 {
 463         wsi->u.hdr.ah->nfrag++;
 464         if (wsi->u.hdr.ah->nfrag == ARRAY_SIZE(wsi->u.hdr.ah->frags)) {
 465                 lwsl_warn("More hdr frags than we can deal with, dropping\n");
 466                 return -1;
 467         }
 468
 469         wsi->u.hdr.ah->frag_index[h] = wsi->u.hdr.ah->nfrag;
 470
 471         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].offset = wsi->u.hdr.ah->pos;
 472         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len = 0;
 473         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].nfrag = 0;
 474
 475         do {
 476                 if (lws_pos_in_bounds(wsi))
 477                         return -1;
 478
 479                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = *s;
 480                 if (*s)
 481                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 482         } while (*s++);
 483
 484         return 0;
 485 }
 486
 487 signed char char_to_hex(const char c)
 488 {
 489         if (c >= '0' && c <= '9')
 490                 return c - '0';
 491
 492         if (c >= 'a' && c <= 'f')
 493                 return c - 'a' + 10;
 494
 495         if (c >= 'A' && c <= 'F')
 496                 return c - 'A' + 10;
 497
 498         return -1;
 499 }
 500
 501 static int LWS_WARN_UNUSED_RESULT
 502 issue_char(struct lws *wsi, unsigned char c)
 503 {
 504         unsigned short frag_len;
 505
 506         if (lws_pos_in_bounds(wsi))
 507                 return -1;
 508
 509         frag_len = wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len;
 510         /*
 511          * If we haven't hit the token limit, just copy the character into
 512          * the header
 513          */
 514         if (frag_len < wsi->u.hdr.current_token_limit) {
 515                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = c;
 516                 if (c)
 517                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 518                 return 0;
 519         }
 520
 521         /* Insert a null character when we *hit* the limit: */
 522         if (frag_len == wsi->u.hdr.current_token_limit) {
 523                 if (lws_pos_in_bounds(wsi))
 524                         return -1;
 525                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = '\0';
 526                 lwsl_warn("header %i exceeds limit %d\n",
 527                           wsi->u.hdr.parser_state,
 528                           wsi->u.hdr.current_token_limit);
 529         }
 530
 531         return 1;
 532 }
 533
 534 int LWS_WARN_UNUSED_RESULT
 535 lws_parse(struct lws *wsi, unsigned char c)
 536 {
 537         static const unsigned char methods[] = {
 538                 WSI_TOKEN_GET_URI,
 539                 WSI_TOKEN_POST_URI,
 540                 WSI_TOKEN_OPTIONS_URI,
 541                 WSI_TOKEN_PUT_URI,
 542                 WSI_TOKEN_PATCH_URI,
 543                 WSI_TOKEN_DELETE_URI,
 544                 WSI_TOKEN_CONNECT,
 545         };
 546         struct allocated_headers *ah = wsi->u.hdr.ah;
 547         struct lws_context *context = wsi->context;
 548         unsigned int n, m, enc = 0;
 549
 550         assert(wsi->u.hdr.ah);
 551
 552         switch (wsi->u.hdr.parser_state) {
 553         default:
 554
 555                 lwsl_parser("WSI_TOK_(%d) '%c'\n", wsi->u.hdr.parser_state, c);
 556
 557                 /* collect into malloc'd buffers */
 558                 /* optional initial space swallow */
 559                 if (!ah->frags[ah->frag_index[wsi->u.hdr.parser_state]].len &&
 560                     c == ' ')
 561                         break;
 562
 563                 for (m = 0; m < ARRAY_SIZE(methods); m++)
 564                         if (wsi->u.hdr.parser_state == methods[m])
 565                                 break;
 566                 if (m == ARRAY_SIZE(methods))
 567                         /* it was not any of the methods */
 568                         goto check_eol;
 569
 570                 /* special URI processing... end at space */
 571
 572                 if (c == ' ') {
 573                         /* enforce starting with / */
 574                         if (!ah->frags[ah->nfrag].len)
 575                                 if (issue_char(wsi, '/') < 0)
 576                                         return -1;
 577
 578                         if (wsi->u.hdr.ups == URIPS_SEEN_SLASH_DOT_DOT) {
 579                                 /*
 580                                  * back up one dir level if possible
 581                                  * safe against header fragmentation because
 582                                  * the method URI can only be in 1 fragment
 583                                  */
 584                                 if (ah->frags[ah->nfrag].len > 2) {
 585                                         ah->pos--;
 586                                         ah->frags[ah->nfrag].len--;
 587                                         do {
 588                                                 ah->pos--;
 589                                                 ah->frags[ah->nfrag].len--;
 590                                         } while (ah->frags[ah->nfrag].len > 1 &&
 591                                                  ah->data[ah->pos] != '/');
 592                                 }
 593                         }
 594
 595                         /* begin parsing HTTP version: */
 596                         if (issue_char(wsi, '\0') < 0)
 597                                 return -1;
 598                         wsi->u.hdr.parser_state = WSI_TOKEN_HTTP;
 599                         goto start_fragment;
 600                 }
 601
 602                 /*
 603                  * PRIORITY 1
 604                  * special URI processing... convert %xx
 605                  */
 606
 607                 switch (wsi->u.hdr.ues) {
 608                 case URIES_IDLE:
 609                         if (c == '%') {
 610                                 wsi->u.hdr.ues = URIES_SEEN_PERCENT;
 611                                 goto swallow;
 612                         }
 613                         break;
 614                 case URIES_SEEN_PERCENT:
 615                         if (char_to_hex(c) < 0)
 616                                 /* illegal post-% char */
 617                                 goto forbid;
 618
 619                         wsi->u.hdr.esc_stash = c;
 620                         wsi->u.hdr.ues = URIES_SEEN_PERCENT_H1;
 621                         goto swallow;
 622
 623                 case URIES_SEEN_PERCENT_H1:
 624                         if (char_to_hex(c) < 0)
 625                                 /* illegal post-% char */
 626                                 goto forbid;
 627
 628                         c = (char_to_hex(wsi->u.hdr.esc_stash) << 4) |
 629                                         char_to_hex(c);
 630                         enc = 1;
 631                         wsi->u.hdr.ues = URIES_IDLE;
 632                         break;
 633                 }
 634
 635                 /*
 636                  * PRIORITY 2
 637                  * special URI processing...
 638                  *  convert /.. or /... or /../ etc to /
 639                  *  convert /./ to /
 640                  *  convert // or /// etc to /
 641                  *  leave /.dir or whatever alone
 642                  */
 643
 644                 switch (wsi->u.hdr.ups) {
 645                 case URIPS_IDLE:
 646                         if (!c)
 647                                 return -1;
 648                         /* genuine delimiter */
 649                         if ((c == '&' || c == ';') && !enc) {
 650                                 if (issue_char(wsi, c) < 0)
 651                                         return -1;
 652                                 /* swallow the terminator */
 653                                 ah->frags[ah->nfrag].len--;
 654                                 /* link to next fragment */
 655                                 ah->frags[ah->nfrag].nfrag = ah->nfrag + 1;
 656                                 ah->nfrag++;
 657                                 if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 658                                         goto excessive;
 659                                 /* start next fragment after the & */
 660                                 wsi->u.hdr.post_literal_equal = 0;
 661                                 ah->frags[ah->nfrag].offset = ah->pos;
 662                                 ah->frags[ah->nfrag].len = 0;
 663                                 ah->frags[ah->nfrag].nfrag = 0;
 664                                 goto swallow;
 665                         }
 666                         /* uriencoded = in the name part, disallow */
 667                         if (c == '=' && enc &&
 668                             ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] &&
 669                             !wsi->u.hdr.post_literal_equal)
 670                                 c = '_';
 671
 672                         /* after the real =, we don't care how many = */
 673                         if (c == '=' && !enc)
 674                                 wsi->u.hdr.post_literal_equal = 1;
 675
 676                         /* + to space */
 677                         if (c == '+' && !enc)
 678                                 c = ' ';
 679                         /* issue the first / always */
 680                         if (c == '/' && !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS])
 681                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 682                         break;
 683                 case URIPS_SEEN_SLASH:
 684                         /* swallow subsequent slashes */
 685                         if (c == '/')
 686                                 goto swallow;
 687                         /* track and swallow the first . after / */
 688                         if (c == '.') {
 689                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT;
 690                                 goto swallow;
 691                         }
 692                         wsi->u.hdr.ups = URIPS_IDLE;
 693                         break;
 694                 case URIPS_SEEN_SLASH_DOT:
 695                         /* swallow second . */
 696                         if (c == '.') {
 697                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT_DOT;
 698                                 goto swallow;
 699                         }
 700                         /* change /./ to / */
 701                         if (c == '/') {
 702                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 703                                 goto swallow;
 704                         }
 705                         /* it was like /.dir ... regurgitate the . */
 706                         wsi->u.hdr.ups = URIPS_IDLE;
 707                         if (issue_char(wsi, '.') < 0)
 708                                 return -1;
 709                         break;
 710
 711                 case URIPS_SEEN_SLASH_DOT_DOT:
 712
 713                         /* /../ or /..[End of URI] --> backup to last / */
 714                         if (c == '/' || c == '?') {
 715                                 /*
 716                                  * back up one dir level if possible
 717                                  * safe against header fragmentation because
 718                                  * the method URI can only be in 1 fragment
 719                                  */
 720                                 if (ah->frags[ah->nfrag].len > 2) {
 721                                         ah->pos--;
 722                                         ah->frags[ah->nfrag].len--;
 723                                         do {
 724                                                 ah->pos--;
 725                                                 ah->frags[ah->nfrag].len--;
 726                                         } while (ah->frags[ah->nfrag].len > 1 &&
 727                                                  ah->data[ah->pos] != '/');
 728                                 }
 729                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 730                                 if (ah->frags[ah->nfrag].len > 1)
 731                                         break;
 732                                 goto swallow;
 733                         }
 734
 735                         /*  /..[^/] ... regurgitate and allow */
 736
 737                         if (issue_char(wsi, '.') < 0)
 738                                 return -1;
 739                         if (issue_char(wsi, '.') < 0)
 740                                 return -1;
 741                         wsi->u.hdr.ups = URIPS_IDLE;
 742                         break;
 743                 }
 744
 745                 if (c == '?' && !enc &&
 746                     !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS]) { /* start of URI arguments */
 747                         if (wsi->u.hdr.ues != URIES_IDLE)
 748                                 goto forbid;
 749
 750                         /* seal off uri header */
 751                         if (issue_char(wsi, '\0') < 0)
 752                                 return -1;
 753
 754                         /* move to using WSI_TOKEN_HTTP_URI_ARGS */
 755                         ah->nfrag++;
 756                         if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 757                                 goto excessive;
 758                         ah->frags[ah->nfrag].offset = ah->pos;
 759                         ah->frags[ah->nfrag].len = 0;
 760                         ah->frags[ah->nfrag].nfrag = 0;
 761
 762                         wsi->u.hdr.post_literal_equal = 0;
 763                         ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] = ah->nfrag;
 764                         wsi->u.hdr.ups = URIPS_IDLE;
 765                         goto swallow;
 766                 }
 767
 768 check_eol:
 769                 /* bail at EOL */
 770                 if (wsi->u.hdr.parser_state != WSI_TOKEN_CHALLENGE &&
 771                     c == '\x0d') {
 772                         if (wsi->u.hdr.ues != URIES_IDLE)
 773                                 goto forbid;
 774
 775                         c = '\0';
 776                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 777                         lwsl_parser("*\n");
 778                 }
 779
 780                 n = issue_char(wsi, c);
 781                 if ((int)n < 0)
 782                         return -1;
 783                 if (n > 0)
 784                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 785
 786 swallow:
 787                 /* per-protocol end of headers management */
 788
 789                 if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 790                         goto set_parsing_complete;
 791                 break;
 792
 793                 /* collecting and checking a name part */
 794         case WSI_TOKEN_NAME_PART:
 795                 lwsl_parser("WSI_TOKEN_NAME_PART '%c' (mode=%d)\n", c, wsi->mode);
 796
 797                 wsi->u.hdr.lextable_pos =
 798                                 lextable_decode(wsi->u.hdr.lextable_pos, c);
 799                 /*
 800                  * Server needs to look out for unknown methods...
 801                  */
 802                 if (wsi->u.hdr.lextable_pos < 0 &&
 803                     wsi->mode == LWSCM_HTTP_SERVING) {
 804                         /* this is not a header we know about */
 805                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 806                                 if (ah->frag_index[methods[m]]) {
 807                                         /*
 808                                          * already had the method, no idea what
 809                                          * this crap from the client is, ignore
 810                                          */
 811                                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 812                                         break;
 813                                 }
 814                         /*
 815                          * hm it's an unknown http method from a client in fact,
 816                          * it cannot be valid http
 817                          */
 818                         if (m == ARRAY_SIZE(methods)) {
 819                                 /*
 820                                  * are we set up to accept raw in these cases?
 821                                  */
 822                                 if (lws_check_opt(wsi->vhost->options,
 823                                            LWS_SERVER_OPTION_FALLBACK_TO_RAW))
 824                                         return 2; /* transition to raw */
 825
 826                                 lwsl_info("Unknown method - dropping\n");
 827                                 goto forbid;
 828                         }
 829                         break;
 830                 }
 831                 /*
 832                  * ...otherwise for a client, let him ignore unknown headers
 833                  * coming from the server
 834                  */
 835                 if (wsi->u.hdr.lextable_pos < 0) {
 836                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 837                         break;
 838                 }
 839
 840                 if (lextable[wsi->u.hdr.lextable_pos] < FAIL_CHAR) {
 841                         /* terminal state */
 842
 843                         n = ((unsigned int)lextable[wsi->u.hdr.lextable_pos] << 8) |
 844                                         lextable[wsi->u.hdr.lextable_pos + 1];
 845
 846                         lwsl_parser("known hdr %d\n", n);
 847                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 848                                 if (n == methods[m] &&
 849                                     ah->frag_index[methods[m]]) {
 850                                         lwsl_warn("Duplicated method\n");
 851                                         return -1;
 852                                 }
 853
 854                         /*
 855                          * WSORIGIN is protocol equiv to ORIGIN,
 856                          * JWebSocket likes to send it, map to ORIGIN
 857                          */
 858                         if (n == WSI_TOKEN_SWORIGIN)
 859                                 n = WSI_TOKEN_ORIGIN;
 860
 861                         wsi->u.hdr.parser_state = (enum lws_token_indexes)
 862                                                         (WSI_TOKEN_GET_URI + n);
 863
 864                         if (context->token_limits)
 865                                 wsi->u.hdr.current_token_limit =
 866                                         context->token_limits->token_limit[
 867                                                        wsi->u.hdr.parser_state];
 868                         else
 869                                 wsi->u.hdr.current_token_limit =
 870                                         wsi->context->max_http_header_data;
 871
 872                         if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 873                                 goto set_parsing_complete;
 874
 875                         goto start_fragment;
 876                 }
 877                 break;
 878
 879 start_fragment:
 880                 ah->nfrag++;
 881 excessive:
 882                 if (ah->nfrag == ARRAY_SIZE(ah->frags)) {
 883                         lwsl_warn("More hdr frags than we can deal with\n");
 884                         return -1;
 885                 }
 886
 887                 ah->frags[ah->nfrag].offset = ah->pos;
 888                 ah->frags[ah->nfrag].len = 0;
 889                 ah->frags[ah->nfrag].nfrag = 0;
 890
 891                 n = ah->frag_index[wsi->u.hdr.parser_state];
 892                 if (!n) { /* first fragment */
 893                         ah->frag_index[wsi->u.hdr.parser_state] = ah->nfrag;
 894                         break;
 895                 }
 896                 /* continuation */
 897                 while (ah->frags[n].nfrag)
 898                         n = ah->frags[n].nfrag;
 899                 ah->frags[n].nfrag = ah->nfrag;
 900
 901                 if (issue_char(wsi, ' ') < 0)
 902                         return -1;
 903                 break;
 904
 905                 /* skipping arg part of a name we didn't recognize */
 906         case WSI_TOKEN_SKIPPING:
 907                 lwsl_parser("WSI_TOKEN_SKIPPING '%c'\n", c);
 908
 909                 if (c == '\x0d')
 910                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 911                 break;
 912
 913         case WSI_TOKEN_SKIPPING_SAW_CR:
 914                 lwsl_parser("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
 915                 if (wsi->u.hdr.ues != URIES_IDLE)
 916                         goto forbid;
 917                 if (c == '\x0a') {
 918                         wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 919                         wsi->u.hdr.lextable_pos = 0;
 920                 } else
 921                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 922                 break;
 923                 /* we're done, ignore anything else */
 924
 925         case WSI_PARSING_COMPLETE:
 926                 lwsl_parser("WSI_PARSING_COMPLETE '%c'\n", c);
 927                 break;
 928         }
 929
 930         return 0;
 931
 932 set_parsing_complete:
 933         if (wsi->u.hdr.ues != URIES_IDLE)
 934                 goto forbid;
 935         if (lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE)) {
 936                 if (lws_hdr_total_length(wsi, WSI_TOKEN_VERSION))
 937                         wsi->ietf_spec_revision =
 938                                atoi(lws_hdr_simple_ptr(wsi, WSI_TOKEN_VERSION));
 939
 940                 lwsl_parser("v%02d hdrs completed\n", wsi->ietf_spec_revision);
 941         }
 942         wsi->u.hdr.parser_state = WSI_PARSING_COMPLETE;
 943         wsi->hdr_parsing_completed = 1;
 944
 945         return 0;
 946
 947 forbid:
 948         lwsl_notice(" forbidding on uri sanitation\n");
 949         lws_return_http_status(wsi, HTTP_STATUS_FORBIDDEN, NULL);
 950         return -1;
 951 }
 952
 953 LWS_VISIBLE int lws_frame_is_binary(struct lws *wsi)
 954 {
 955         return wsi->u.ws.frame_is_binary;
 956 }
 957
 958 void
 959 lws_add_wsi_to_draining_ext_list(struct lws *wsi)
 960 {
 961         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 962
 963         if (wsi->u.ws.rx_draining_ext)
 964                 return;
 965
 966         lwsl_ext("%s: RX EXT DRAINING: Adding to list\n", __func__);
 967
 968         wsi->u.ws.rx_draining_ext = 1;
 969         wsi->u.ws.rx_draining_ext_list = pt->rx_draining_ext_list;
 970         pt->rx_draining_ext_list = wsi;
 971 }
 972
 973 void
 974 lws_remove_wsi_from_draining_ext_list(struct lws *wsi)
 975 {
 976         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 977         struct lws **w = &pt->rx_draining_ext_list;
 978
 979         if (!wsi->u.ws.rx_draining_ext)
 980                 return;
 981
 982         lwsl_ext("%s: RX EXT DRAINING: Removing from list\n", __func__);
 983
 984         wsi->u.ws.rx_draining_ext = 0;
 985
 986         /* remove us from context draining ext list */
 987         while (*w) {
 988                 if (*w == wsi) {
 989                         /* if us, point it instead to who we were pointing to */
 990                         *w = wsi->u.ws.rx_draining_ext_list;
 991                         break;
 992                 }
 993                 w = &((*w)->u.ws.rx_draining_ext_list);
 994         }
 995         wsi->u.ws.rx_draining_ext_list = NULL;
 996 }
 997
 998 /*
 999  * client-parser.c: lws_client_rx_sm() needs to be roughly kept in
1000  *   sync with changes here, esp related to ext draining
1001  */
1002
1003 int
1004 lws_rx_sm(struct lws *wsi, unsigned char c)
1005 {
1006         int callback_action = LWS_CALLBACK_RECEIVE;
1007         int ret = 0, n, rx_draining_ext = 0;
1008         struct lws_tokens eff_buf;
1009
1010         eff_buf.token = NULL;
1011         eff_buf.token_len = 0;
1012         if (wsi->socket_is_permanently_unusable)
1013                 return -1;
1014
1015         switch (wsi->lws_rx_parse_state) {
1016         case LWS_RXPS_NEW:
1017                 if (wsi->u.ws.rx_draining_ext) {
1018                         eff_buf.token = NULL;
1019                         eff_buf.token_len = 0;
1020                         lws_remove_wsi_from_draining_ext_list(wsi);
1021                         rx_draining_ext = 1;
1022                         lwsl_debug("%s: doing draining flow\n", __func__);
1023
1024                         goto drain_extension;
1025                 }
1026                 switch (wsi->ietf_spec_revision) {
1027                 case 13:
1028                         /*
1029                          * no prepended frame key any more
1030                          */
1031                         wsi->u.ws.all_zero_nonce = 1;
1032                         goto handle_first;
1033
1034                 default:
1035                         lwsl_warn("lws_rx_sm: unknown spec version %d\n",
1036                                                        wsi->ietf_spec_revision);
1037                         break;
1038                 }
1039                 break;
1040         case LWS_RXPS_04_mask_1:
1041                 wsi->u.ws.mask[1] = c;
1042                 if (c)
1043                         wsi->u.ws.all_zero_nonce = 0;
1044                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_2;
1045                 break;
1046         case LWS_RXPS_04_mask_2:
1047                 wsi->u.ws.mask[2] = c;
1048                 if (c)
1049                         wsi->u.ws.all_zero_nonce = 0;
1050                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_3;
1051                 break;
1052         case LWS_RXPS_04_mask_3:
1053                 wsi->u.ws.mask[3] = c;
1054                 if (c)
1055                         wsi->u.ws.all_zero_nonce = 0;
1056
1057                 /*
1058                  * start from the zero'th byte in the XOR key buffer since
1059                  * this is the start of a frame with a new key
1060                  */
1061
1062                 wsi->u.ws.mask_idx = 0;
1063
1064                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_1;
1065                 break;
1066
1067         /*
1068          *  04 logical framing from the spec (all this is masked when incoming
1069          *  and has to be unmasked)
1070          *
1071          * We ignore the possibility of extension data because we don't
1072          * negotiate any extensions at the moment.
1073          *
1074          *    0                   1                   2                   3
1075          *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1076          *   +-+-+-+-+-------+-+-------------+-------------------------------+
1077          *   |F|R|R|R| opcode|R| Payload len |    Extended payload length    |
1078          *   |I|S|S|S|  (4)  |S|     (7)     |             (16/63)           |
1079          *   |N|V|V|V|       |V|             |   (if payload len==126/127)   |
1080          *   | |1|2|3|       |4|             |                               |
1081          *   +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
1082          *   |     Extended payload length continued, if payload len == 127  |
1083          *   + - - - - - - - - - - - - - - - +-------------------------------+
1084          *   |                               |         Extension data        |
1085          *   +-------------------------------+ - - - - - - - - - - - - - - - +
1086          *   :                                                               :
1087          *   +---------------------------------------------------------------+
1088          *   :                       Application data                        :
1089          *   +---------------------------------------------------------------+
1090          *
1091          *  We pass payload through to userland as soon as we get it, ignoring
1092          *  FIN.  It's up to userland to buffer it up if it wants to see a
1093          *  whole unfragmented block of the original size (which may be up to
1094          *  2^63 long!)
1095          */
1096
1097         case LWS_RXPS_04_FRAME_HDR_1:
1098 handle_first:
1099
1100                 wsi->u.ws.opcode = c & 0xf;
1101                 wsi->u.ws.rsv = c & 0x70;
1102                 wsi->u.ws.final = !!((c >> 7) & 1);
1103
1104                 switch (wsi->u.ws.opcode) {
1105                 case LWSWSOPC_TEXT_FRAME:
1106                 case LWSWSOPC_BINARY_FRAME:
1107                         wsi->u.ws.rsv_first_msg = (c & 0x70);
1108                         wsi->u.ws.frame_is_binary =
1109                              wsi->u.ws.opcode == LWSWSOPC_BINARY_FRAME;
1110                         break;
1111                 case 3:
1112                 case 4:
1113                 case 5:
1114                 case 6:
1115                 case 7:
1116                 case 0xb:
1117                 case 0xc:
1118                 case 0xd:
1119                 case 0xe:
1120                 case 0xf:
1121                         lwsl_info("illegal opcode\n");
1122                         return -1;
1123                 }
1124                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
1125                 break;
1126
1127         case LWS_RXPS_04_FRAME_HDR_LEN:
1128
1129                 wsi->u.ws.this_frame_masked = !!(c & 0x80);
1130
1131                 switch (c & 0x7f) {
1132                 case 126:
1133                         /* control frames are not allowed to have big lengths */
1134                         if (wsi->u.ws.opcode & 8)
1135                                 goto illegal_ctl_length;
1136
1137                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
1138                         break;
1139                 case 127:
1140                         /* control frames are not allowed to have big lengths */
1141                         if (wsi->u.ws.opcode & 8)
1142                                 goto illegal_ctl_length;
1143
1144                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
1145                         break;
1146                 default:
1147                         wsi->u.ws.rx_packet_length = c & 0x7f;
1148                         if (wsi->u.ws.this_frame_masked)
1149                                 wsi->lws_rx_parse_state =
1150                                                 LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1151                         else
1152                                 if (wsi->u.ws.rx_packet_length)
1153                                         wsi->lws_rx_parse_state =
1154                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1155                                 else {
1156                                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1157                                         goto spill;
1158                                 }
1159                         break;
1160                 }
1161                 break;
1162
1163         case LWS_RXPS_04_FRAME_HDR_LEN16_2:
1164                 wsi->u.ws.rx_packet_length = c << 8;
1165                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
1166                 break;
1167
1168         case LWS_RXPS_04_FRAME_HDR_LEN16_1:
1169                 wsi->u.ws.rx_packet_length |= c;
1170                 if (wsi->u.ws.this_frame_masked)
1171                         wsi->lws_rx_parse_state =
1172                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1173                 else
1174                         wsi->lws_rx_parse_state =
1175                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1176                 break;
1177
1178         case LWS_RXPS_04_FRAME_HDR_LEN64_8:
1179                 if (c & 0x80) {
1180                         lwsl_warn("b63 of length must be zero\n");
1181                         /* kill the connection */
1182                         return -1;
1183                 }
1184 #if defined __LP64__
1185                 wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
1186 #else
1187                 wsi->u.ws.rx_packet_length = 0;
1188 #endif
1189                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
1190                 break;
1191
1192         case LWS_RXPS_04_FRAME_HDR_LEN64_7:
1193 #if defined __LP64__
1194                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
1195 #endif
1196                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
1197                 break;
1198
1199         case LWS_RXPS_04_FRAME_HDR_LEN64_6:
1200 #if defined __LP64__
1201                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
1202 #endif
1203                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
1204                 break;
1205
1206         case LWS_RXPS_04_FRAME_HDR_LEN64_5:
1207 #if defined __LP64__
1208                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
1209 #endif
1210                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
1211                 break;
1212
1213         case LWS_RXPS_04_FRAME_HDR_LEN64_4:
1214                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
1215                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
1216                 break;
1217
1218         case LWS_RXPS_04_FRAME_HDR_LEN64_3:
1219                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
1220                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
1221                 break;
1222
1223         case LWS_RXPS_04_FRAME_HDR_LEN64_2:
1224                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
1225                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
1226                 break;
1227
1228         case LWS_RXPS_04_FRAME_HDR_LEN64_1:
1229                 wsi->u.ws.rx_packet_length |= ((size_t)c);
1230                 if (wsi->u.ws.this_frame_masked)
1231                         wsi->lws_rx_parse_state =
1232                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1233                 else
1234                         wsi->lws_rx_parse_state =
1235                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1236                 break;
1237
1238         case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
1239                 wsi->u.ws.mask[0] = c;
1240                 if (c)
1241                         wsi->u.ws.all_zero_nonce = 0;
1242                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
1243                 break;
1244
1245         case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
1246                 wsi->u.ws.mask[1] = c;
1247                 if (c)
1248                         wsi->u.ws.all_zero_nonce = 0;
1249                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
1250                 break;
1251
1252         case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
1253                 wsi->u.ws.mask[2] = c;
1254                 if (c)
1255                         wsi->u.ws.all_zero_nonce = 0;
1256                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
1257                 break;
1258
1259         case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
1260                 wsi->u.ws.mask[3] = c;
1261                 if (c)
1262                         wsi->u.ws.all_zero_nonce = 0;
1263                 wsi->lws_rx_parse_state =
1264                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1265                 wsi->u.ws.mask_idx = 0;
1266                 if (wsi->u.ws.rx_packet_length == 0) {
1267                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1268                         goto spill;
1269                 }
1270                 break;
1271
1272
1273         case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
1274                 assert(wsi->u.ws.rx_ubuf);
1275
1276                 if (wsi->u.ws.rx_draining_ext)
1277                         goto drain_extension;
1278
1279                 if (wsi->u.ws.rx_ubuf_head + LWS_PRE >=
1280                     wsi->u.ws.rx_ubuf_alloc) {
1281                         lwsl_err("Attempted overflow \n");
1282                         return -1;
1283                 }
1284                 if (wsi->u.ws.all_zero_nonce)
1285                         wsi->u.ws.rx_ubuf[LWS_PRE +
1286                                          (wsi->u.ws.rx_ubuf_head++)] = c;
1287                 else
1288                         wsi->u.ws.rx_ubuf[LWS_PRE +
1289                                (wsi->u.ws.rx_ubuf_head++)] =
1290                                    c ^ wsi->u.ws.mask[
1291                                             (wsi->u.ws.mask_idx++) & 3];
1292
1293                 if (--wsi->u.ws.rx_packet_length == 0) {
1294                         /* spill because we have the whole frame */
1295                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1296                         goto spill;
1297                 }
1298
1299                 /*
1300                  * if there's no protocol max frame size given, we are
1301                  * supposed to default to context->pt_serv_buf_size
1302                  */
1303
1304                 if (!wsi->protocol->rx_buffer_size &&
1305                     wsi->u.ws.rx_ubuf_head != wsi->context->pt_serv_buf_size)
1306                         break;
1307                 else
1308                         if (wsi->protocol->rx_buffer_size &&
1309                                         wsi->u.ws.rx_ubuf_head !=
1310                                                   wsi->protocol->rx_buffer_size)
1311                         break;
1312
1313                 /* spill because we filled our rx buffer */
1314 spill:
1315                 /*
1316                  * is this frame a control packet we should take care of at this
1317                  * layer?  If so service it and hide it from the user callback
1318                  */
1319
1320                 lwsl_parser("spill on %s\n", wsi->protocol->name);
1321
1322                 switch (wsi->u.ws.opcode) {
1323                 case LWSWSOPC_CLOSE:
1324
1325                         /* is this an acknowledgement of our close? */
1326                         if (wsi->state == LWSS_AWAITING_CLOSE_ACK) {
1327                                 /*
1328                                  * fine he has told us he is closing too, let's
1329                                  * finish our close
1330                                  */
1331                                 lwsl_parser("seen client close ack\n");
1332                                 return -1;
1333                         }
1334                         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
1335                                 /* if he sends us 2 CLOSE, kill him */
1336                                 return -1;
1337
1338                         if (lws_partial_buffered(wsi)) {
1339                                 /*
1340                                  * if we're in the middle of something,
1341                                  * we can't do a normal close response and
1342                                  * have to just close our end.
1343                                  */
1344                                 wsi->socket_is_permanently_unusable = 1;
1345                                 lwsl_parser("Closing on peer close due to Pending tx\n");
1346                                 return -1;
1347                         }
1348
1349                         if (user_callback_handle_rxflow(
1350                                         wsi->protocol->callback, wsi,
1351                                         LWS_CALLBACK_WS_PEER_INITIATED_CLOSE,
1352                                         wsi->user_space,
1353                                         &wsi->u.ws.rx_ubuf[LWS_PRE],
1354                                         wsi->u.ws.rx_ubuf_head))
1355                                 return -1;
1356
1357                         lwsl_parser("server sees client close packet\n");
1358                         wsi->state = LWSS_RETURNED_CLOSE_ALREADY;
1359                         /* deal with the close packet contents as a PONG */
1360                         wsi->u.ws.payload_is_close = 1;
1361                         goto process_as_ping;
1362
1363                 case LWSWSOPC_PING:
1364                         lwsl_info("received %d byte ping, sending pong\n",
1365                                                  wsi->u.ws.rx_ubuf_head);
1366
1367                         if (wsi->u.ws.ping_pending_flag) {
1368                                 /*
1369                                  * there is already a pending ping payload
1370                                  * we should just log and drop
1371                                  */
1372                                 lwsl_parser("DROP PING since one pending\n");
1373                                 goto ping_drop;
1374                         }
1375 process_as_ping:
1376                         /* control packets can only be < 128 bytes long */
1377                         if (wsi->u.ws.rx_ubuf_head > 128 - 3) {
1378                                 lwsl_parser("DROP PING payload too large\n");
1379                                 goto ping_drop;
1380                         }
1381
1382                         /* stash the pong payload */
1383                         memcpy(wsi->u.ws.ping_payload_buf + LWS_PRE,
1384                                &wsi->u.ws.rx_ubuf[LWS_PRE],
1385                                 wsi->u.ws.rx_ubuf_head);
1386
1387                         wsi->u.ws.ping_payload_len = wsi->u.ws.rx_ubuf_head;
1388                         wsi->u.ws.ping_pending_flag = 1;
1389
1390                         /* get it sent as soon as possible */
1391                         lws_callback_on_writable(wsi);
1392 ping_drop:
1393                         wsi->u.ws.rx_ubuf_head = 0;
1394                         return 0;
1395
1396                 case LWSWSOPC_PONG:
1397                         lwsl_info("received pong\n");
1398                         lwsl_hexdump(&wsi->u.ws.rx_ubuf[LWS_PRE],
1399                                      wsi->u.ws.rx_ubuf_head);
1400
1401                         if (wsi->pending_timeout == PENDING_TIMEOUT_WS_PONG_CHECK_GET_PONG) {
1402                                 lwsl_info("received expected PONG on wsi %p\n", wsi);
1403                                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1404                         }
1405
1406                         /* issue it */
1407                         callback_action = LWS_CALLBACK_RECEIVE_PONG;
1408                         break;
1409
1410                 case LWSWSOPC_TEXT_FRAME:
1411                 case LWSWSOPC_BINARY_FRAME:
1412                 case LWSWSOPC_CONTINUATION:
1413                         break;
1414
1415                 default:
1416                         lwsl_parser("passing opc %x up to exts\n",
1417                                     wsi->u.ws.opcode);
1418                         /*
1419                          * It's something special we can't understand here.
1420                          * Pass the payload up to the extension's parsing
1421                          * state machine.
1422                          */
1423
1424                         eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1425                         eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1426
1427                         if (lws_ext_cb_active(wsi, LWS_EXT_CB_EXTENDED_PAYLOAD_RX,
1428                                               &eff_buf, 0) <= 0)
1429                                 /* not handle or fail */
1430                                 lwsl_ext("ext opc opcode 0x%x unknown\n",
1431                                          wsi->u.ws.opcode);
1432
1433                         wsi->u.ws.rx_ubuf_head = 0;
1434                         return 0;
1435                 }
1436
1437                 /*
1438                  * No it's real payload, pass it up to the user callback.
1439                  * It's nicely buffered with the pre-padding taken care of
1440                  * so it can be sent straight out again using lws_write
1441                  */
1442
1443                 eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1444                 eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1445
1446 drain_extension:
1447                 lwsl_ext("%s: passing %d to ext\n", __func__, eff_buf.token_len);
1448
1449                 if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
1450                     wsi->state == LWSS_AWAITING_CLOSE_ACK)
1451                         goto already_done;
1452
1453                 n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_RX, &eff_buf, 0);
1454                 /* eff_buf may be pointing somewhere completely different now,
1455                  * it's the output
1456                  */
1457                 if (n < 0) {
1458                         /*
1459                          * we may rely on this to get RX, just drop connection
1460                          */
1461                         wsi->socket_is_permanently_unusable = 1;
1462                         return -1;
1463                 }
1464
1465                 if (rx_draining_ext && eff_buf.token_len == 0)
1466                         goto already_done;
1467
1468                 if (n && eff_buf.token_len) {
1469                         /* extension had more... main loop will come back */
1470                         lws_add_wsi_to_draining_ext_list(wsi);
1471                 } else
1472                         lws_remove_wsi_from_draining_ext_list(wsi);
1473
1474                 if (eff_buf.token_len > 0 ||
1475                     callback_action == LWS_CALLBACK_RECEIVE_PONG) {
1476                         eff_buf.token[eff_buf.token_len] = '\0';
1477
1478                         if (wsi->protocol->callback) {
1479
1480                                 if (callback_action == LWS_CALLBACK_RECEIVE_PONG)
1481                                         lwsl_info("Doing pong callback\n");
1482
1483                                 ret = user_callback_handle_rxflow(
1484                                                 wsi->protocol->callback,
1485                                                 wsi,
1486                                                 (enum lws_callback_reasons)callback_action,
1487                                                 wsi->user_space,
1488                                                 eff_buf.token,
1489                                                 eff_buf.token_len);
1490                         }
1491                         else
1492                                 lwsl_err("No callback on payload spill!\n");
1493                 }
1494
1495 already_done:
1496                 wsi->u.ws.rx_ubuf_head = 0;
1497                 break;
1498         }
1499
1500         return ret;
1501
1502 illegal_ctl_length:
1503
1504         lwsl_warn("Control frame with xtended length is illegal\n");
1505         /* kill the connection */
1506         return -1;
1507 }
1508
1509 LWS_VISIBLE size_t
1510 lws_remaining_packet_payload(struct lws *wsi)
1511 {
1512         return wsi->u.ws.rx_packet_length;
1513 }
1514
1515 /* Once we reach LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED, we know how much
1516  * to expect in that state and can deal with it in bulk more efficiently.
1517  */
1518
1519 int
1520 lws_payload_until_length_exhausted(struct lws *wsi, unsigned char **buf,
1521                                    size_t *len)
1522 {
1523         unsigned char *buffer = *buf, mask[4];
1524         int buffer_size, n;
1525         unsigned int avail;
1526         char *rx_ubuf;
1527
1528         if (wsi->protocol->rx_buffer_size)
1529                 buffer_size = wsi->protocol->rx_buffer_size;
1530         else
1531                 buffer_size = wsi->context->pt_serv_buf_size;
1532         avail = buffer_size - wsi->u.ws.rx_ubuf_head;
1533
1534         /* do not consume more than we should */
1535         if (avail > wsi->u.ws.rx_packet_length)
1536                 avail = wsi->u.ws.rx_packet_length;
1537
1538         /* do not consume more than what is in the buffer */
1539         if (avail > *len)
1540                 avail = *len;
1541
1542         /* we want to leave 1 byte for the parser to handle properly */
1543         if (avail <= 1)
1544                 return 0;
1545
1546         avail--;
1547         rx_ubuf = wsi->u.ws.rx_ubuf + LWS_PRE + wsi->u.ws.rx_ubuf_head;
1548         if (wsi->u.ws.all_zero_nonce)
1549                 memcpy(rx_ubuf, buffer, avail);
1550         else {
1551
1552                 for (n = 0; n < 4; n++)
1553                         mask[n] = wsi->u.ws.mask[(wsi->u.ws.mask_idx + n) & 3];
1554
1555                 /* deal with 4-byte chunks using unwrapped loop */
1556                 n = avail >> 2;
1557                 while (n--) {
1558                         *(rx_ubuf++) = *(buffer++) ^ mask[0];
1559                         *(rx_ubuf++) = *(buffer++) ^ mask[1];
1560                         *(rx_ubuf++) = *(buffer++) ^ mask[2];
1561                         *(rx_ubuf++) = *(buffer++) ^ mask[3];
1562                 }
1563                 /* and the remaining bytes bytewise */
1564                 for (n = 0; n < (int)(avail & 3); n++)
1565                         *(rx_ubuf++) = *(buffer++) ^ mask[n];
1566
1567                 wsi->u.ws.mask_idx = (wsi->u.ws.mask_idx + avail) & 3;
1568         }
1569
1570         (*buf) += avail;
1571         wsi->u.ws.rx_ubuf_head += avail;
1572         wsi->u.ws.rx_packet_length -= avail;
1573         *len -= avail;
1574
1575         return avail;
1576 }