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