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                 lws_pt_unlock(pt);
 326
 327                 if (!lws_client_connect_via_info2(wsi)) {
 328                         /* our client connect has failed, the wsi
 329                          * has been closed
 330                          */
 331
 332                         return -1;
 333                 }
 334                 return 0;
 335         }
 336 #endif
 337
 338         assert(!!pt->ah_wait_list_length == !!(int)(long)pt->ah_wait_list);
 339 bail:
 340         lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
 341           (void *)wsi, (void *)ah, wsi->tsi,
 342           pt->ah_count_in_use);
 343         lws_pt_unlock(pt);
 344
 345         return 0;
 346 }
 347
 348 LWS_VISIBLE int
 349 lws_hdr_fragment_length(struct lws *wsi, enum lws_token_indexes h, int frag_idx)
 350 {
 351         int n;
 352
 353         n = wsi->u.hdr.ah->frag_index[h];
 354         if (!n)
 355                 return 0;
 356         do {
 357                 if (!frag_idx)
 358                         return wsi->u.hdr.ah->frags[n].len;
 359                 n = wsi->u.hdr.ah->frags[n].nfrag;
 360         } while (frag_idx-- && n);
 361
 362         return 0;
 363 }
 364
 365 LWS_VISIBLE int lws_hdr_total_length(struct lws *wsi, enum lws_token_indexes h)
 366 {
 367         int n;
 368         int len = 0;
 369
 370         n = wsi->u.hdr.ah->frag_index[h];
 371         if (!n)
 372                 return 0;
 373         do {
 374                 len += wsi->u.hdr.ah->frags[n].len;
 375                 n = wsi->u.hdr.ah->frags[n].nfrag;
 376         } while (n);
 377
 378         return len;
 379 }
 380
 381 LWS_VISIBLE int lws_hdr_copy_fragment(struct lws *wsi, char *dst, int len,
 382                                       enum lws_token_indexes h, int frag_idx)
 383 {
 384         int n = 0;
 385         int f = wsi->u.hdr.ah->frag_index[h];
 386
 387         if (!f)
 388                 return -1;
 389
 390         while (n < frag_idx) {
 391                 f = wsi->u.hdr.ah->frags[f].nfrag;
 392                 if (!f)
 393                         return -1;
 394                 n++;
 395         }
 396
 397         if (wsi->u.hdr.ah->frags[f].len >= len)
 398                 return -1;
 399
 400         memcpy(dst, wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[f].offset,
 401                wsi->u.hdr.ah->frags[f].len);
 402         dst[wsi->u.hdr.ah->frags[f].len] = '\0';
 403
 404         return wsi->u.hdr.ah->frags[f].len;
 405 }
 406
 407 LWS_VISIBLE int lws_hdr_copy(struct lws *wsi, char *dst, int len,
 408                              enum lws_token_indexes h)
 409 {
 410         int toklen = lws_hdr_total_length(wsi, h);
 411         int n;
 412
 413         if (toklen >= len)
 414                 return -1;
 415
 416         n = wsi->u.hdr.ah->frag_index[h];
 417         if (!n)
 418                 return 0;
 419
 420         do {
 421                 strcpy(dst, &wsi->u.hdr.ah->data[wsi->u.hdr.ah->frags[n].offset]);
 422                 dst += wsi->u.hdr.ah->frags[n].len;
 423                 n = wsi->u.hdr.ah->frags[n].nfrag;
 424         } while (n);
 425
 426         return toklen;
 427 }
 428
 429 char *lws_hdr_simple_ptr(struct lws *wsi, enum lws_token_indexes h)
 430 {
 431         int n;
 432
 433         n = wsi->u.hdr.ah->frag_index[h];
 434         if (!n)
 435                 return NULL;
 436
 437         return wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[n].offset;
 438 }
 439
 440 int LWS_WARN_UNUSED_RESULT
 441 lws_pos_in_bounds(struct lws *wsi)
 442 {
 443         if (wsi->u.hdr.ah->pos < (unsigned int)wsi->context->max_http_header_data)
 444                 return 0;
 445
 446         if (wsi->u.hdr.ah->pos == wsi->context->max_http_header_data) {
 447                 lwsl_err("Ran out of header data space\n");
 448                 return 1;
 449         }
 450
 451         /*
 452          * with these tests everywhere, it should never be able to exceed
 453          * the limit, only meet the limit
 454          */
 455
 456         lwsl_err("%s: pos %d, limit %d\n", __func__, wsi->u.hdr.ah->pos,
 457                  wsi->context->max_http_header_data);
 458         assert(0);
 459
 460         return 1;
 461 }
 462
 463 int LWS_WARN_UNUSED_RESULT
 464 lws_hdr_simple_create(struct lws *wsi, enum lws_token_indexes h, const char *s)
 465 {
 466         wsi->u.hdr.ah->nfrag++;
 467         if (wsi->u.hdr.ah->nfrag == ARRAY_SIZE(wsi->u.hdr.ah->frags)) {
 468                 lwsl_warn("More hdr frags than we can deal with, dropping\n");
 469                 return -1;
 470         }
 471
 472         wsi->u.hdr.ah->frag_index[h] = wsi->u.hdr.ah->nfrag;
 473
 474         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].offset = wsi->u.hdr.ah->pos;
 475         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len = 0;
 476         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].nfrag = 0;
 477
 478         do {
 479                 if (lws_pos_in_bounds(wsi))
 480                         return -1;
 481
 482                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = *s;
 483                 if (*s)
 484                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 485         } while (*s++);
 486
 487         return 0;
 488 }
 489
 490 signed char char_to_hex(const char c)
 491 {
 492         if (c >= '0' && c <= '9')
 493                 return c - '0';
 494
 495         if (c >= 'a' && c <= 'f')
 496                 return c - 'a' + 10;
 497
 498         if (c >= 'A' && c <= 'F')
 499                 return c - 'A' + 10;
 500
 501         return -1;
 502 }
 503
 504 static int LWS_WARN_UNUSED_RESULT
 505 issue_char(struct lws *wsi, unsigned char c)
 506 {
 507         unsigned short frag_len;
 508
 509         if (lws_pos_in_bounds(wsi))
 510                 return -1;
 511
 512         frag_len = wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len;
 513         /*
 514          * If we haven't hit the token limit, just copy the character into
 515          * the header
 516          */
 517         if (frag_len < wsi->u.hdr.current_token_limit) {
 518                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = c;
 519                 if (c)
 520                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 521                 return 0;
 522         }
 523
 524         /* Insert a null character when we *hit* the limit: */
 525         if (frag_len == wsi->u.hdr.current_token_limit) {
 526                 if (lws_pos_in_bounds(wsi))
 527                         return -1;
 528                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = '\0';
 529                 lwsl_warn("header %i exceeds limit %d\n",
 530                           wsi->u.hdr.parser_state,
 531                           wsi->u.hdr.current_token_limit);
 532         }
 533
 534         return 1;
 535 }
 536
 537 int LWS_WARN_UNUSED_RESULT
 538 lws_parse(struct lws *wsi, unsigned char c)
 539 {
 540         static const unsigned char methods[] = {
 541                 WSI_TOKEN_GET_URI,
 542                 WSI_TOKEN_POST_URI,
 543                 WSI_TOKEN_OPTIONS_URI,
 544                 WSI_TOKEN_PUT_URI,
 545                 WSI_TOKEN_PATCH_URI,
 546                 WSI_TOKEN_DELETE_URI,
 547                 WSI_TOKEN_CONNECT,
 548         };
 549         struct allocated_headers *ah = wsi->u.hdr.ah;
 550         struct lws_context *context = wsi->context;
 551         unsigned int n, m, enc = 0;
 552
 553         assert(wsi->u.hdr.ah);
 554
 555         switch (wsi->u.hdr.parser_state) {
 556         default:
 557
 558                 lwsl_parser("WSI_TOK_(%d) '%c'\n", wsi->u.hdr.parser_state, c);
 559
 560                 /* collect into malloc'd buffers */
 561                 /* optional initial space swallow */
 562                 if (!ah->frags[ah->frag_index[wsi->u.hdr.parser_state]].len &&
 563                     c == ' ')
 564                         break;
 565
 566                 for (m = 0; m < ARRAY_SIZE(methods); m++)
 567                         if (wsi->u.hdr.parser_state == methods[m])
 568                                 break;
 569                 if (m == ARRAY_SIZE(methods))
 570                         /* it was not any of the methods */
 571                         goto check_eol;
 572
 573                 /* special URI processing... end at space */
 574
 575                 if (c == ' ') {
 576                         /* enforce starting with / */
 577                         if (!ah->frags[ah->nfrag].len)
 578                                 if (issue_char(wsi, '/') < 0)
 579                                         return -1;
 580
 581                         if (wsi->u.hdr.ups == URIPS_SEEN_SLASH_DOT_DOT) {
 582                                 /*
 583                                  * back up one dir level if possible
 584                                  * safe against header fragmentation because
 585                                  * the method URI can only be in 1 fragment
 586                                  */
 587                                 if (ah->frags[ah->nfrag].len > 2) {
 588                                         ah->pos--;
 589                                         ah->frags[ah->nfrag].len--;
 590                                         do {
 591                                                 ah->pos--;
 592                                                 ah->frags[ah->nfrag].len--;
 593                                         } while (ah->frags[ah->nfrag].len > 1 &&
 594                                                  ah->data[ah->pos] != '/');
 595                                 }
 596                         }
 597
 598                         /* begin parsing HTTP version: */
 599                         if (issue_char(wsi, '\0') < 0)
 600                                 return -1;
 601                         wsi->u.hdr.parser_state = WSI_TOKEN_HTTP;
 602                         goto start_fragment;
 603                 }
 604
 605                 /*
 606                  * PRIORITY 1
 607                  * special URI processing... convert %xx
 608                  */
 609
 610                 switch (wsi->u.hdr.ues) {
 611                 case URIES_IDLE:
 612                         if (c == '%') {
 613                                 wsi->u.hdr.ues = URIES_SEEN_PERCENT;
 614                                 goto swallow;
 615                         }
 616                         break;
 617                 case URIES_SEEN_PERCENT:
 618                         if (char_to_hex(c) < 0)
 619                                 /* illegal post-% char */
 620                                 goto forbid;
 621
 622                         wsi->u.hdr.esc_stash = c;
 623                         wsi->u.hdr.ues = URIES_SEEN_PERCENT_H1;
 624                         goto swallow;
 625
 626                 case URIES_SEEN_PERCENT_H1:
 627                         if (char_to_hex(c) < 0)
 628                                 /* illegal post-% char */
 629                                 goto forbid;
 630
 631                         c = (char_to_hex(wsi->u.hdr.esc_stash) << 4) |
 632                                         char_to_hex(c);
 633                         enc = 1;
 634                         wsi->u.hdr.ues = URIES_IDLE;
 635                         break;
 636                 }
 637
 638                 /*
 639                  * PRIORITY 2
 640                  * special URI processing...
 641                  *  convert /.. or /... or /../ etc to /
 642                  *  convert /./ to /
 643                  *  convert // or /// etc to /
 644                  *  leave /.dir or whatever alone
 645                  */
 646
 647                 switch (wsi->u.hdr.ups) {
 648                 case URIPS_IDLE:
 649                         if (!c)
 650                                 return -1;
 651                         /* genuine delimiter */
 652                         if ((c == '&' || c == ';') && !enc) {
 653                                 if (issue_char(wsi, c) < 0)
 654                                         return -1;
 655                                 /* swallow the terminator */
 656                                 ah->frags[ah->nfrag].len--;
 657                                 /* link to next fragment */
 658                                 ah->frags[ah->nfrag].nfrag = ah->nfrag + 1;
 659                                 ah->nfrag++;
 660                                 if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 661                                         goto excessive;
 662                                 /* start next fragment after the & */
 663                                 wsi->u.hdr.post_literal_equal = 0;
 664                                 ah->frags[ah->nfrag].offset = ah->pos;
 665                                 ah->frags[ah->nfrag].len = 0;
 666                                 ah->frags[ah->nfrag].nfrag = 0;
 667                                 goto swallow;
 668                         }
 669                         /* uriencoded = in the name part, disallow */
 670                         if (c == '=' && enc &&
 671                             ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] &&
 672                             !wsi->u.hdr.post_literal_equal)
 673                                 c = '_';
 674
 675                         /* after the real =, we don't care how many = */
 676                         if (c == '=' && !enc)
 677                                 wsi->u.hdr.post_literal_equal = 1;
 678
 679                         /* + to space */
 680                         if (c == '+' && !enc)
 681                                 c = ' ';
 682                         /* issue the first / always */
 683                         if (c == '/' && !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS])
 684                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 685                         break;
 686                 case URIPS_SEEN_SLASH:
 687                         /* swallow subsequent slashes */
 688                         if (c == '/')
 689                                 goto swallow;
 690                         /* track and swallow the first . after / */
 691                         if (c == '.') {
 692                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT;
 693                                 goto swallow;
 694                         }
 695                         wsi->u.hdr.ups = URIPS_IDLE;
 696                         break;
 697                 case URIPS_SEEN_SLASH_DOT:
 698                         /* swallow second . */
 699                         if (c == '.') {
 700                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT_DOT;
 701                                 goto swallow;
 702                         }
 703                         /* change /./ to / */
 704                         if (c == '/') {
 705                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 706                                 goto swallow;
 707                         }
 708                         /* it was like /.dir ... regurgitate the . */
 709                         wsi->u.hdr.ups = URIPS_IDLE;
 710                         if (issue_char(wsi, '.') < 0)
 711                                 return -1;
 712                         break;
 713
 714                 case URIPS_SEEN_SLASH_DOT_DOT:
 715
 716                         /* /../ or /..[End of URI] --> backup to last / */
 717                         if (c == '/' || c == '?') {
 718                                 /*
 719                                  * back up one dir level if possible
 720                                  * safe against header fragmentation because
 721                                  * the method URI can only be in 1 fragment
 722                                  */
 723                                 if (ah->frags[ah->nfrag].len > 2) {
 724                                         ah->pos--;
 725                                         ah->frags[ah->nfrag].len--;
 726                                         do {
 727                                                 ah->pos--;
 728                                                 ah->frags[ah->nfrag].len--;
 729                                         } while (ah->frags[ah->nfrag].len > 1 &&
 730                                                  ah->data[ah->pos] != '/');
 731                                 }
 732                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 733                                 if (ah->frags[ah->nfrag].len > 1)
 734                                         break;
 735                                 goto swallow;
 736                         }
 737
 738                         /*  /..[^/] ... regurgitate and allow */
 739
 740                         if (issue_char(wsi, '.') < 0)
 741                                 return -1;
 742                         if (issue_char(wsi, '.') < 0)
 743                                 return -1;
 744                         wsi->u.hdr.ups = URIPS_IDLE;
 745                         break;
 746                 }
 747
 748                 if (c == '?' && !enc &&
 749                     !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS]) { /* start of URI arguments */
 750                         if (wsi->u.hdr.ues != URIES_IDLE)
 751                                 goto forbid;
 752
 753                         /* seal off uri header */
 754                         if (issue_char(wsi, '\0') < 0)
 755                                 return -1;
 756
 757                         /* move to using WSI_TOKEN_HTTP_URI_ARGS */
 758                         ah->nfrag++;
 759                         if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 760                                 goto excessive;
 761                         ah->frags[ah->nfrag].offset = ah->pos;
 762                         ah->frags[ah->nfrag].len = 0;
 763                         ah->frags[ah->nfrag].nfrag = 0;
 764
 765                         wsi->u.hdr.post_literal_equal = 0;
 766                         ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] = ah->nfrag;
 767                         wsi->u.hdr.ups = URIPS_IDLE;
 768                         goto swallow;
 769                 }
 770
 771 check_eol:
 772                 /* bail at EOL */
 773                 if (wsi->u.hdr.parser_state != WSI_TOKEN_CHALLENGE &&
 774                     c == '\x0d') {
 775                         if (wsi->u.hdr.ues != URIES_IDLE)
 776                                 goto forbid;
 777
 778                         c = '\0';
 779                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 780                         lwsl_parser("*\n");
 781                 }
 782
 783                 n = issue_char(wsi, c);
 784                 if ((int)n < 0)
 785                         return -1;
 786                 if (n > 0)
 787                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 788
 789 swallow:
 790                 /* per-protocol end of headers management */
 791
 792                 if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 793                         goto set_parsing_complete;
 794                 break;
 795
 796                 /* collecting and checking a name part */
 797         case WSI_TOKEN_NAME_PART:
 798                 lwsl_parser("WSI_TOKEN_NAME_PART '%c' (mode=%d)\n", c, wsi->mode);
 799
 800                 wsi->u.hdr.lextable_pos =
 801                                 lextable_decode(wsi->u.hdr.lextable_pos, c);
 802                 /*
 803                  * Server needs to look out for unknown methods...
 804                  */
 805                 if (wsi->u.hdr.lextable_pos < 0 &&
 806                     wsi->mode == LWSCM_HTTP_SERVING) {
 807                         /* this is not a header we know about */
 808                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 809                                 if (ah->frag_index[methods[m]]) {
 810                                         /*
 811                                          * already had the method, no idea what
 812                                          * this crap from the client is, ignore
 813                                          */
 814                                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 815                                         break;
 816                                 }
 817                         /*
 818                          * hm it's an unknown http method from a client in fact,
 819                          * it cannot be valid http
 820                          */
 821                         if (m == ARRAY_SIZE(methods)) {
 822                                 /*
 823                                  * are we set up to accept raw in these cases?
 824                                  */
 825                                 if (lws_check_opt(wsi->vhost->options,
 826                                            LWS_SERVER_OPTION_FALLBACK_TO_RAW))
 827                                         return 2; /* transition to raw */
 828
 829                                 lwsl_info("Unknown method - dropping\n");
 830                                 goto forbid;
 831                         }
 832                         break;
 833                 }
 834                 /*
 835                  * ...otherwise for a client, let him ignore unknown headers
 836                  * coming from the server
 837                  */
 838                 if (wsi->u.hdr.lextable_pos < 0) {
 839                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 840                         break;
 841                 }
 842
 843                 if (lextable[wsi->u.hdr.lextable_pos] < FAIL_CHAR) {
 844                         /* terminal state */
 845
 846                         n = ((unsigned int)lextable[wsi->u.hdr.lextable_pos] << 8) |
 847                                         lextable[wsi->u.hdr.lextable_pos + 1];
 848
 849                         lwsl_parser("known hdr %d\n", n);
 850                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 851                                 if (n == methods[m] &&
 852                                     ah->frag_index[methods[m]]) {
 853                                         lwsl_warn("Duplicated method\n");
 854                                         return -1;
 855                                 }
 856
 857                         /*
 858                          * WSORIGIN is protocol equiv to ORIGIN,
 859                          * JWebSocket likes to send it, map to ORIGIN
 860                          */
 861                         if (n == WSI_TOKEN_SWORIGIN)
 862                                 n = WSI_TOKEN_ORIGIN;
 863
 864                         wsi->u.hdr.parser_state = (enum lws_token_indexes)
 865                                                         (WSI_TOKEN_GET_URI + n);
 866
 867                         if (context->token_limits)
 868                                 wsi->u.hdr.current_token_limit =
 869                                         context->token_limits->token_limit[
 870                                                        wsi->u.hdr.parser_state];
 871                         else
 872                                 wsi->u.hdr.current_token_limit =
 873                                         wsi->context->max_http_header_data;
 874
 875                         if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 876                                 goto set_parsing_complete;
 877
 878                         goto start_fragment;
 879                 }
 880                 break;
 881
 882 start_fragment:
 883                 ah->nfrag++;
 884 excessive:
 885                 if (ah->nfrag == ARRAY_SIZE(ah->frags)) {
 886                         lwsl_warn("More hdr frags than we can deal with\n");
 887                         return -1;
 888                 }
 889
 890                 ah->frags[ah->nfrag].offset = ah->pos;
 891                 ah->frags[ah->nfrag].len = 0;
 892                 ah->frags[ah->nfrag].nfrag = 0;
 893
 894                 n = ah->frag_index[wsi->u.hdr.parser_state];
 895                 if (!n) { /* first fragment */
 896                         ah->frag_index[wsi->u.hdr.parser_state] = ah->nfrag;
 897                         break;
 898                 }
 899                 /* continuation */
 900                 while (ah->frags[n].nfrag)
 901                         n = ah->frags[n].nfrag;
 902                 ah->frags[n].nfrag = ah->nfrag;
 903
 904                 if (issue_char(wsi, ' ') < 0)
 905                         return -1;
 906                 break;
 907
 908                 /* skipping arg part of a name we didn't recognize */
 909         case WSI_TOKEN_SKIPPING:
 910                 lwsl_parser("WSI_TOKEN_SKIPPING '%c'\n", c);
 911
 912                 if (c == '\x0d')
 913                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 914                 break;
 915
 916         case WSI_TOKEN_SKIPPING_SAW_CR:
 917                 lwsl_parser("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
 918                 if (wsi->u.hdr.ues != URIES_IDLE)
 919                         goto forbid;
 920                 if (c == '\x0a') {
 921                         wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 922                         wsi->u.hdr.lextable_pos = 0;
 923                 } else
 924                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 925                 break;
 926                 /* we're done, ignore anything else */
 927
 928         case WSI_PARSING_COMPLETE:
 929                 lwsl_parser("WSI_PARSING_COMPLETE '%c'\n", c);
 930                 break;
 931         }
 932
 933         return 0;
 934
 935 set_parsing_complete:
 936         if (wsi->u.hdr.ues != URIES_IDLE)
 937                 goto forbid;
 938         if (lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE)) {
 939                 if (lws_hdr_total_length(wsi, WSI_TOKEN_VERSION))
 940                         wsi->ietf_spec_revision =
 941                                atoi(lws_hdr_simple_ptr(wsi, WSI_TOKEN_VERSION));
 942
 943                 lwsl_parser("v%02d hdrs completed\n", wsi->ietf_spec_revision);
 944         }
 945         wsi->u.hdr.parser_state = WSI_PARSING_COMPLETE;
 946         wsi->hdr_parsing_completed = 1;
 947
 948         return 0;
 949
 950 forbid:
 951         lwsl_notice(" forbidding on uri sanitation\n");
 952         lws_return_http_status(wsi, HTTP_STATUS_FORBIDDEN, NULL);
 953         return -1;
 954 }
 955
 956 LWS_VISIBLE int lws_frame_is_binary(struct lws *wsi)
 957 {
 958         return wsi->u.ws.frame_is_binary;
 959 }
 960
 961 void
 962 lws_add_wsi_to_draining_ext_list(struct lws *wsi)
 963 {
 964         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 965
 966         if (wsi->u.ws.rx_draining_ext)
 967                 return;
 968
 969         lwsl_ext("%s: RX EXT DRAINING: Adding to list\n", __func__);
 970
 971         wsi->u.ws.rx_draining_ext = 1;
 972         wsi->u.ws.rx_draining_ext_list = pt->rx_draining_ext_list;
 973         pt->rx_draining_ext_list = wsi;
 974 }
 975
 976 void
 977 lws_remove_wsi_from_draining_ext_list(struct lws *wsi)
 978 {
 979         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 980         struct lws **w = &pt->rx_draining_ext_list;
 981
 982         if (!wsi->u.ws.rx_draining_ext)
 983                 return;
 984
 985         lwsl_ext("%s: RX EXT DRAINING: Removing from list\n", __func__);
 986
 987         wsi->u.ws.rx_draining_ext = 0;
 988
 989         /* remove us from context draining ext list */
 990         while (*w) {
 991                 if (*w == wsi) {
 992                         /* if us, point it instead to who we were pointing to */
 993                         *w = wsi->u.ws.rx_draining_ext_list;
 994                         break;
 995                 }
 996                 w = &((*w)->u.ws.rx_draining_ext_list);
 997         }
 998         wsi->u.ws.rx_draining_ext_list = NULL;
 999 }
1000
1001 /*
1002  * client-parser.c: lws_client_rx_sm() needs to be roughly kept in
1003  *   sync with changes here, esp related to ext draining
1004  */
1005
1006 int
1007 lws_rx_sm(struct lws *wsi, unsigned char c)
1008 {
1009         int callback_action = LWS_CALLBACK_RECEIVE;
1010         int ret = 0, n, rx_draining_ext = 0;
1011         struct lws_tokens eff_buf;
1012
1013         eff_buf.token = NULL;
1014         eff_buf.token_len = 0;
1015         if (wsi->socket_is_permanently_unusable)
1016                 return -1;
1017
1018         switch (wsi->lws_rx_parse_state) {
1019         case LWS_RXPS_NEW:
1020                 if (wsi->u.ws.rx_draining_ext) {
1021                         eff_buf.token = NULL;
1022                         eff_buf.token_len = 0;
1023                         lws_remove_wsi_from_draining_ext_list(wsi);
1024                         rx_draining_ext = 1;
1025                         lwsl_debug("%s: doing draining flow\n", __func__);
1026
1027                         goto drain_extension;
1028                 }
1029                 switch (wsi->ietf_spec_revision) {
1030                 case 13:
1031                         /*
1032                          * no prepended frame key any more
1033                          */
1034                         wsi->u.ws.all_zero_nonce = 1;
1035                         goto handle_first;
1036
1037                 default:
1038                         lwsl_warn("lws_rx_sm: unknown spec version %d\n",
1039                                                        wsi->ietf_spec_revision);
1040                         break;
1041                 }
1042                 break;
1043         case LWS_RXPS_04_mask_1:
1044                 wsi->u.ws.mask[1] = c;
1045                 if (c)
1046                         wsi->u.ws.all_zero_nonce = 0;
1047                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_2;
1048                 break;
1049         case LWS_RXPS_04_mask_2:
1050                 wsi->u.ws.mask[2] = c;
1051                 if (c)
1052                         wsi->u.ws.all_zero_nonce = 0;
1053                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_3;
1054                 break;
1055         case LWS_RXPS_04_mask_3:
1056                 wsi->u.ws.mask[3] = c;
1057                 if (c)
1058                         wsi->u.ws.all_zero_nonce = 0;
1059
1060                 /*
1061                  * start from the zero'th byte in the XOR key buffer since
1062                  * this is the start of a frame with a new key
1063                  */
1064
1065                 wsi->u.ws.mask_idx = 0;
1066
1067                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_1;
1068                 break;
1069
1070         /*
1071          *  04 logical framing from the spec (all this is masked when incoming
1072          *  and has to be unmasked)
1073          *
1074          * We ignore the possibility of extension data because we don't
1075          * negotiate any extensions at the moment.
1076          *
1077          *    0                   1                   2                   3
1078          *    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
1079          *   +-+-+-+-+-------+-+-------------+-------------------------------+
1080          *   |F|R|R|R| opcode|R| Payload len |    Extended payload length    |
1081          *   |I|S|S|S|  (4)  |S|     (7)     |             (16/63)           |
1082          *   |N|V|V|V|       |V|             |   (if payload len==126/127)   |
1083          *   | |1|2|3|       |4|             |                               |
1084          *   +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
1085          *   |     Extended payload length continued, if payload len == 127  |
1086          *   + - - - - - - - - - - - - - - - +-------------------------------+
1087          *   |                               |         Extension data        |
1088          *   +-------------------------------+ - - - - - - - - - - - - - - - +
1089          *   :                                                               :
1090          *   +---------------------------------------------------------------+
1091          *   :                       Application data                        :
1092          *   +---------------------------------------------------------------+
1093          *
1094          *  We pass payload through to userland as soon as we get it, ignoring
1095          *  FIN.  It's up to userland to buffer it up if it wants to see a
1096          *  whole unfragmented block of the original size (which may be up to
1097          *  2^63 long!)
1098          */
1099
1100         case LWS_RXPS_04_FRAME_HDR_1:
1101 handle_first:
1102
1103                 wsi->u.ws.opcode = c & 0xf;
1104                 wsi->u.ws.rsv = c & 0x70;
1105                 wsi->u.ws.final = !!((c >> 7) & 1);
1106
1107                 switch (wsi->u.ws.opcode) {
1108                 case LWSWSOPC_TEXT_FRAME:
1109                 case LWSWSOPC_BINARY_FRAME:
1110                         wsi->u.ws.rsv_first_msg = (c & 0x70);
1111                         wsi->u.ws.frame_is_binary =
1112                              wsi->u.ws.opcode == LWSWSOPC_BINARY_FRAME;
1113                         break;
1114                 case 3:
1115                 case 4:
1116                 case 5:
1117                 case 6:
1118                 case 7:
1119                 case 0xb:
1120                 case 0xc:
1121                 case 0xd:
1122                 case 0xe:
1123                 case 0xf:
1124                         lwsl_info("illegal opcode\n");
1125                         return -1;
1126                 }
1127                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
1128                 break;
1129
1130         case LWS_RXPS_04_FRAME_HDR_LEN:
1131
1132                 wsi->u.ws.this_frame_masked = !!(c & 0x80);
1133
1134                 switch (c & 0x7f) {
1135                 case 126:
1136                         /* control frames are not allowed to have big lengths */
1137                         if (wsi->u.ws.opcode & 8)
1138                                 goto illegal_ctl_length;
1139
1140                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
1141                         break;
1142                 case 127:
1143                         /* control frames are not allowed to have big lengths */
1144                         if (wsi->u.ws.opcode & 8)
1145                                 goto illegal_ctl_length;
1146
1147                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
1148                         break;
1149                 default:
1150                         wsi->u.ws.rx_packet_length = c & 0x7f;
1151                         if (wsi->u.ws.this_frame_masked)
1152                                 wsi->lws_rx_parse_state =
1153                                                 LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1154                         else
1155                                 if (wsi->u.ws.rx_packet_length)
1156                                         wsi->lws_rx_parse_state =
1157                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1158                                 else {
1159                                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1160                                         goto spill;
1161                                 }
1162                         break;
1163                 }
1164                 break;
1165
1166         case LWS_RXPS_04_FRAME_HDR_LEN16_2:
1167                 wsi->u.ws.rx_packet_length = c << 8;
1168                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
1169                 break;
1170
1171         case LWS_RXPS_04_FRAME_HDR_LEN16_1:
1172                 wsi->u.ws.rx_packet_length |= c;
1173                 if (wsi->u.ws.this_frame_masked)
1174                         wsi->lws_rx_parse_state =
1175                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1176                 else
1177                         wsi->lws_rx_parse_state =
1178                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1179                 break;
1180
1181         case LWS_RXPS_04_FRAME_HDR_LEN64_8:
1182                 if (c & 0x80) {
1183                         lwsl_warn("b63 of length must be zero\n");
1184                         /* kill the connection */
1185                         return -1;
1186                 }
1187 #if defined __LP64__
1188                 wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
1189 #else
1190                 wsi->u.ws.rx_packet_length = 0;
1191 #endif
1192                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
1193                 break;
1194
1195         case LWS_RXPS_04_FRAME_HDR_LEN64_7:
1196 #if defined __LP64__
1197                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
1198 #endif
1199                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
1200                 break;
1201
1202         case LWS_RXPS_04_FRAME_HDR_LEN64_6:
1203 #if defined __LP64__
1204                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
1205 #endif
1206                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
1207                 break;
1208
1209         case LWS_RXPS_04_FRAME_HDR_LEN64_5:
1210 #if defined __LP64__
1211                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
1212 #endif
1213                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
1214                 break;
1215
1216         case LWS_RXPS_04_FRAME_HDR_LEN64_4:
1217                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
1218                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
1219                 break;
1220
1221         case LWS_RXPS_04_FRAME_HDR_LEN64_3:
1222                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
1223                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
1224                 break;
1225
1226         case LWS_RXPS_04_FRAME_HDR_LEN64_2:
1227                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
1228                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
1229                 break;
1230
1231         case LWS_RXPS_04_FRAME_HDR_LEN64_1:
1232                 wsi->u.ws.rx_packet_length |= ((size_t)c);
1233                 if (wsi->u.ws.this_frame_masked)
1234                         wsi->lws_rx_parse_state =
1235                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1236                 else
1237                         wsi->lws_rx_parse_state =
1238                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1239                 break;
1240
1241         case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
1242                 wsi->u.ws.mask[0] = c;
1243                 if (c)
1244                         wsi->u.ws.all_zero_nonce = 0;
1245                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
1246                 break;
1247
1248         case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
1249                 wsi->u.ws.mask[1] = c;
1250                 if (c)
1251                         wsi->u.ws.all_zero_nonce = 0;
1252                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
1253                 break;
1254
1255         case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
1256                 wsi->u.ws.mask[2] = c;
1257                 if (c)
1258                         wsi->u.ws.all_zero_nonce = 0;
1259                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
1260                 break;
1261
1262         case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
1263                 wsi->u.ws.mask[3] = c;
1264                 if (c)
1265                         wsi->u.ws.all_zero_nonce = 0;
1266                 wsi->lws_rx_parse_state =
1267                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1268                 wsi->u.ws.mask_idx = 0;
1269                 if (wsi->u.ws.rx_packet_length == 0) {
1270                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1271                         goto spill;
1272                 }
1273                 break;
1274
1275
1276         case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
1277                 assert(wsi->u.ws.rx_ubuf);
1278
1279                 if (wsi->u.ws.rx_draining_ext)
1280                         goto drain_extension;
1281
1282                 if (wsi->u.ws.rx_ubuf_head + LWS_PRE >=
1283                     wsi->u.ws.rx_ubuf_alloc) {
1284                         lwsl_err("Attempted overflow \n");
1285                         return -1;
1286                 }
1287                 if (wsi->u.ws.all_zero_nonce)
1288                         wsi->u.ws.rx_ubuf[LWS_PRE +
1289                                          (wsi->u.ws.rx_ubuf_head++)] = c;
1290                 else
1291                         wsi->u.ws.rx_ubuf[LWS_PRE +
1292                                (wsi->u.ws.rx_ubuf_head++)] =
1293                                    c ^ wsi->u.ws.mask[
1294                                             (wsi->u.ws.mask_idx++) & 3];
1295
1296                 if (--wsi->u.ws.rx_packet_length == 0) {
1297                         /* spill because we have the whole frame */
1298                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1299                         goto spill;
1300                 }
1301
1302                 /*
1303                  * if there's no protocol max frame size given, we are
1304                  * supposed to default to context->pt_serv_buf_size
1305                  */
1306
1307                 if (!wsi->protocol->rx_buffer_size &&
1308                     wsi->u.ws.rx_ubuf_head != wsi->context->pt_serv_buf_size)
1309                         break;
1310                 else
1311                         if (wsi->protocol->rx_buffer_size &&
1312                                         wsi->u.ws.rx_ubuf_head !=
1313                                                   wsi->protocol->rx_buffer_size)
1314                         break;
1315
1316                 /* spill because we filled our rx buffer */
1317 spill:
1318                 /*
1319                  * is this frame a control packet we should take care of at this
1320                  * layer?  If so service it and hide it from the user callback
1321                  */
1322
1323                 lwsl_parser("spill on %s\n", wsi->protocol->name);
1324
1325                 switch (wsi->u.ws.opcode) {
1326                 case LWSWSOPC_CLOSE:
1327
1328                         /* is this an acknowledgement of our close? */
1329                         if (wsi->state == LWSS_AWAITING_CLOSE_ACK) {
1330                                 /*
1331                                  * fine he has told us he is closing too, let's
1332                                  * finish our close
1333                                  */
1334                                 lwsl_parser("seen client close ack\n");
1335                                 return -1;
1336                         }
1337                         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
1338                                 /* if he sends us 2 CLOSE, kill him */
1339                                 return -1;
1340
1341                         if (lws_partial_buffered(wsi)) {
1342                                 /*
1343                                  * if we're in the middle of something,
1344                                  * we can't do a normal close response and
1345                                  * have to just close our end.
1346                                  */
1347                                 wsi->socket_is_permanently_unusable = 1;
1348                                 lwsl_parser("Closing on peer close due to Pending tx\n");
1349                                 return -1;
1350                         }
1351
1352                         if (user_callback_handle_rxflow(
1353                                         wsi->protocol->callback, wsi,
1354                                         LWS_CALLBACK_WS_PEER_INITIATED_CLOSE,
1355                                         wsi->user_space,
1356                                         &wsi->u.ws.rx_ubuf[LWS_PRE],
1357                                         wsi->u.ws.rx_ubuf_head))
1358                                 return -1;
1359
1360                         lwsl_parser("server sees client close packet\n");
1361                         wsi->state = LWSS_RETURNED_CLOSE_ALREADY;
1362                         /* deal with the close packet contents as a PONG */
1363                         wsi->u.ws.payload_is_close = 1;
1364                         goto process_as_ping;
1365
1366                 case LWSWSOPC_PING:
1367                         lwsl_info("received %d byte ping, sending pong\n",
1368                                                  wsi->u.ws.rx_ubuf_head);
1369
1370                         if (wsi->u.ws.ping_pending_flag) {
1371                                 /*
1372                                  * there is already a pending ping payload
1373                                  * we should just log and drop
1374                                  */
1375                                 lwsl_parser("DROP PING since one pending\n");
1376                                 goto ping_drop;
1377                         }
1378 process_as_ping:
1379                         /* control packets can only be < 128 bytes long */
1380                         if (wsi->u.ws.rx_ubuf_head > 128 - 3) {
1381                                 lwsl_parser("DROP PING payload too large\n");
1382                                 goto ping_drop;
1383                         }
1384
1385                         /* stash the pong payload */
1386                         memcpy(wsi->u.ws.ping_payload_buf + LWS_PRE,
1387                                &wsi->u.ws.rx_ubuf[LWS_PRE],
1388                                 wsi->u.ws.rx_ubuf_head);
1389
1390                         wsi->u.ws.ping_payload_len = wsi->u.ws.rx_ubuf_head;
1391                         wsi->u.ws.ping_pending_flag = 1;
1392
1393                         /* get it sent as soon as possible */
1394                         lws_callback_on_writable(wsi);
1395 ping_drop:
1396                         wsi->u.ws.rx_ubuf_head = 0;
1397                         return 0;
1398
1399                 case LWSWSOPC_PONG:
1400                         lwsl_info("received pong\n");
1401                         lwsl_hexdump(&wsi->u.ws.rx_ubuf[LWS_PRE],
1402                                      wsi->u.ws.rx_ubuf_head);
1403
1404                         if (wsi->pending_timeout == PENDING_TIMEOUT_WS_PONG_CHECK_GET_PONG) {
1405                                 lwsl_info("received expected PONG on wsi %p\n", wsi);
1406                                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1407                         }
1408
1409                         /* issue it */
1410                         callback_action = LWS_CALLBACK_RECEIVE_PONG;
1411                         break;
1412
1413                 case LWSWSOPC_TEXT_FRAME:
1414                 case LWSWSOPC_BINARY_FRAME:
1415                 case LWSWSOPC_CONTINUATION:
1416                         break;
1417
1418                 default:
1419                         lwsl_parser("passing opc %x up to exts\n",
1420                                     wsi->u.ws.opcode);
1421                         /*
1422                          * It's something special we can't understand here.
1423                          * Pass the payload up to the extension's parsing
1424                          * state machine.
1425                          */
1426
1427                         eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1428                         eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1429
1430                         if (lws_ext_cb_active(wsi, LWS_EXT_CB_EXTENDED_PAYLOAD_RX,
1431                                               &eff_buf, 0) <= 0)
1432                                 /* not handle or fail */
1433                                 lwsl_ext("ext opc opcode 0x%x unknown\n",
1434                                          wsi->u.ws.opcode);
1435
1436                         wsi->u.ws.rx_ubuf_head = 0;
1437                         return 0;
1438                 }
1439
1440                 /*
1441                  * No it's real payload, pass it up to the user callback.
1442                  * It's nicely buffered with the pre-padding taken care of
1443                  * so it can be sent straight out again using lws_write
1444                  */
1445
1446                 eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1447                 eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1448
1449 drain_extension:
1450                 lwsl_ext("%s: passing %d to ext\n", __func__, eff_buf.token_len);
1451
1452                 if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
1453                     wsi->state == LWSS_AWAITING_CLOSE_ACK)
1454                         goto already_done;
1455
1456                 n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_RX, &eff_buf, 0);
1457                 /* eff_buf may be pointing somewhere completely different now,
1458                  * it's the output
1459                  */
1460                 if (n < 0) {
1461                         /*
1462                          * we may rely on this to get RX, just drop connection
1463                          */
1464                         wsi->socket_is_permanently_unusable = 1;
1465                         return -1;
1466                 }
1467
1468                 if (rx_draining_ext && eff_buf.token_len == 0)
1469                         goto already_done;
1470
1471                 if (n && eff_buf.token_len) {
1472                         /* extension had more... main loop will come back */
1473                         lws_add_wsi_to_draining_ext_list(wsi);
1474                 } else
1475                         lws_remove_wsi_from_draining_ext_list(wsi);
1476
1477                 if (eff_buf.token_len > 0 ||
1478                     callback_action == LWS_CALLBACK_RECEIVE_PONG) {
1479                         eff_buf.token[eff_buf.token_len] = '\0';
1480
1481                         if (wsi->protocol->callback) {
1482
1483                                 if (callback_action == LWS_CALLBACK_RECEIVE_PONG)
1484                                         lwsl_info("Doing pong callback\n");
1485
1486                                 ret = user_callback_handle_rxflow(
1487                                                 wsi->protocol->callback,
1488                                                 wsi,
1489                                                 (enum lws_callback_reasons)callback_action,
1490                                                 wsi->user_space,
1491                                                 eff_buf.token,
1492                                                 eff_buf.token_len);
1493                         }
1494                         else
1495                                 lwsl_err("No callback on payload spill!\n");
1496                 }
1497
1498 already_done:
1499                 wsi->u.ws.rx_ubuf_head = 0;
1500                 break;
1501         }
1502
1503         return ret;
1504
1505 illegal_ctl_length:
1506
1507         lwsl_warn("Control frame with xtended length is illegal\n");
1508         /* kill the connection */
1509         return -1;
1510 }
1511
1512 LWS_VISIBLE size_t
1513 lws_remaining_packet_payload(struct lws *wsi)
1514 {
1515         return wsi->u.ws.rx_packet_length;
1516 }
1517
1518 /* Once we reach LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED, we know how much
1519  * to expect in that state and can deal with it in bulk more efficiently.
1520  */
1521
1522 int
1523 lws_payload_until_length_exhausted(struct lws *wsi, unsigned char **buf,
1524                                    size_t *len)
1525 {
1526         unsigned char *buffer = *buf, mask[4];
1527         int buffer_size, n;
1528         unsigned int avail;
1529         char *rx_ubuf;
1530
1531         if (wsi->protocol->rx_buffer_size)
1532                 buffer_size = wsi->protocol->rx_buffer_size;
1533         else
1534                 buffer_size = wsi->context->pt_serv_buf_size;
1535         avail = buffer_size - wsi->u.ws.rx_ubuf_head;
1536
1537         /* do not consume more than we should */
1538         if (avail > wsi->u.ws.rx_packet_length)
1539                 avail = wsi->u.ws.rx_packet_length;
1540
1541         /* do not consume more than what is in the buffer */
1542         if (avail > *len)
1543                 avail = *len;
1544
1545         /* we want to leave 1 byte for the parser to handle properly */
1546         if (avail <= 1)
1547                 return 0;
1548
1549         avail--;
1550         rx_ubuf = wsi->u.ws.rx_ubuf + LWS_PRE + wsi->u.ws.rx_ubuf_head;
1551         if (wsi->u.ws.all_zero_nonce)
1552                 memcpy(rx_ubuf, buffer, avail);
1553         else {
1554
1555                 for (n = 0; n < 4; n++)
1556                         mask[n] = wsi->u.ws.mask[(wsi->u.ws.mask_idx + n) & 3];
1557
1558                 /* deal with 4-byte chunks using unwrapped loop */
1559                 n = avail >> 2;
1560                 while (n--) {
1561                         *(rx_ubuf++) = *(buffer++) ^ mask[0];
1562                         *(rx_ubuf++) = *(buffer++) ^ mask[1];
1563                         *(rx_ubuf++) = *(buffer++) ^ mask[2];
1564                         *(rx_ubuf++) = *(buffer++) ^ mask[3];
1565                 }
1566                 /* and the remaining bytes bytewise */
1567                 for (n = 0; n < (int)(avail & 3); n++)
1568                         *(rx_ubuf++) = *(buffer++) ^ mask[n];
1569
1570                 wsi->u.ws.mask_idx = (wsi->u.ws.mask_idx + avail) & 3;
1571         }
1572
1573         (*buf) += avail;
1574         wsi->u.ws.rx_ubuf_head += avail;
1575         wsi->u.ws.rx_packet_length -= avail;
1576         *len -= avail;
1577
1578         return avail;
1579 }