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         wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
  90         wsi->u.hdr.lextable_pos = 0;
  91
  92         /* since we will restart the ah, our new headers are not completed */
  93         // wsi->hdr_parsing_completed = 0;
  94
  95         /*
  96          * if we inherited pending rx (from socket adoption deferred
  97          * processing), apply and free it.
  98          */
  99         if (wsi->u.hdr.preamble_rx) {
 100                 memcpy(ah->rx, wsi->u.hdr.preamble_rx,
 101                        wsi->u.hdr.preamble_rx_len);
 102                 ah->rxlen = wsi->u.hdr.preamble_rx_len;
 103                 lws_free_set_NULL(wsi->u.hdr.preamble_rx);
 104
 105                 if (autoservice) {
 106                         lwsl_notice("%s: calling service on readbuf ah\n", __func__);
 107
 108                         pt = &wsi->context->pt[(int)wsi->tsi];
 109
 110                         /* unlike a normal connect, we have the headers already
 111                          * (or the first part of them anyway)
 112                          */
 113                         pfd = &pt->fds[wsi->position_in_fds_table];
 114                         pfd->revents |= LWS_POLLIN;
 115                         lwsl_err("%s: calling service\n", __func__);
 116                         lws_service_fd_tsi(wsi->context, pfd, wsi->tsi);
 117                 }
 118         }
 119 }
 120
 121 int LWS_WARN_UNUSED_RESULT
 122 lws_header_table_attach(struct lws *wsi, int autoservice)
 123 {
 124         struct lws_context *context = wsi->context;
 125         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 126         struct lws_pollargs pa;
 127         struct lws **pwsi;
 128         int n;
 129
 130         lwsl_info("%s: wsi %p: ah %p (tsi %d, count = %d) in\n", __func__, (void *)wsi,
 131                  (void *)wsi->u.hdr.ah, wsi->tsi, pt->ah_count_in_use);
 132
 133         /* if we are already bound to one, just clear it down */
 134         if (wsi->u.hdr.ah) {
 135                 lwsl_info("cleardown\n");
 136                 goto reset;
 137         }
 138
 139         lws_pt_lock(pt);
 140         pwsi = &pt->ah_wait_list;
 141         while (*pwsi) {
 142                 if (*pwsi == wsi) {
 143                         /* if already waiting on list, if no new ah just ret */
 144                         if (pt->ah_count_in_use ==
 145                             context->max_http_header_pool) {
 146                                 lwsl_notice("%s: no free ah to attach\n", __func__);
 147                                 goto bail;
 148                         }
 149                         /* new ah.... remove ourselves from waiting list */
 150                         *pwsi = wsi->u.hdr.ah_wait_list; /* set our prev to our next */
 151                         wsi->u.hdr.ah_wait_list = NULL; /* no next any more */
 152                         pt->ah_wait_list_length--;
 153                         break;
 154                 }
 155                 pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 156         }
 157         /*
 158          * pool is all busy... add us to waiting list and return that we
 159          * weren't able to deliver it right now
 160          */
 161         if (pt->ah_count_in_use == context->max_http_header_pool) {
 162                 lwsl_info("%s: adding %p to ah waiting list\n", __func__, wsi);
 163                 wsi->u.hdr.ah_wait_list = pt->ah_wait_list;
 164                 pt->ah_wait_list = wsi;
 165                 pt->ah_wait_list_length++;
 166
 167                 /* we cannot accept input then */
 168
 169                 _lws_change_pollfd(wsi, LWS_POLLIN, 0, &pa);
 170                 goto bail;
 171         }
 172
 173         for (n = 0; n < context->max_http_header_pool; n++)
 174                 if (!pt->ah_pool[n].in_use)
 175                         break;
 176
 177         /* if the count of in use said something free... */
 178         assert(n != context->max_http_header_pool);
 179
 180         wsi->u.hdr.ah = &pt->ah_pool[n];
 181         wsi->u.hdr.ah->in_use = 1;
 182         pt->ah_pool[n].wsi = wsi; /* mark our owner */
 183         pt->ah_count_in_use++;
 184
 185         _lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
 186
 187         lwsl_info("%s: did attach wsi %p: ah %p: count %d (on exit)\n", __func__,
 188                   (void *)wsi, (void *)wsi->u.hdr.ah, pt->ah_count_in_use);
 189
 190         lws_pt_unlock(pt);
 191
 192 reset:
 193
 194         /* and reset the rx state */
 195         wsi->u.hdr.ah->rxpos = 0;
 196         wsi->u.hdr.ah->rxlen = 0;
 197
 198         lws_header_table_reset(wsi, autoservice);
 199         time(&wsi->u.hdr.ah->assigned);
 200
 201 #ifndef LWS_NO_CLIENT
 202         if (wsi->state == LWSS_CLIENT_UNCONNECTED)
 203                 if (!lws_client_connect_via_info2(wsi))
 204                         /* our client connect has failed, the wsi
 205                          * has been closed
 206                          */
 207                         return -1;
 208 #endif
 209
 210         return 0;
 211
 212 bail:
 213         lws_pt_unlock(pt);
 214
 215         return 1;
 216 }
 217
 218 int lws_header_table_detach(struct lws *wsi, int autoservice)
 219 {
 220         struct lws_context *context = wsi->context;
 221         struct allocated_headers *ah = wsi->u.hdr.ah;
 222         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 223         struct lws_pollargs pa;
 224         struct lws **pwsi;
 225         time_t now;
 226
 227         lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
 228                   (void *)wsi, (void *)ah, wsi->tsi,
 229                   pt->ah_count_in_use);
 230
 231         if (wsi->u.hdr.preamble_rx)
 232                 lws_free_set_NULL(wsi->u.hdr.preamble_rx);
 233
 234         /* may not be detached while he still has unprocessed rx */
 235         if (ah && ah->rxpos != ah->rxlen) {
 236                 lwsl_err("%s: %p: CANNOT DETACH rxpos:%d, rxlen:%d\n", __func__, wsi,
 237                                 ah->rxpos, ah->rxlen);
 238                 assert(ah->rxpos == ah->rxlen);
 239
 240                 return 0;
 241         }
 242
 243         lws_pt_lock(pt);
 244
 245         pwsi = &pt->ah_wait_list;
 246         if (!ah) { /* remove from wait list if none attached */
 247                 while (*pwsi) {
 248                         if (*pwsi == wsi) {
 249                                 lwsl_info("%s: wsi %p, remv wait\n",
 250                                           __func__, wsi);
 251                                 *pwsi = wsi->u.hdr.ah_wait_list;
 252                                 wsi->u.hdr.ah_wait_list = NULL;
 253                                 pt->ah_wait_list_length--;
 254                                 goto bail;
 255                         }
 256                         pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 257                 }
 258                 /* no ah, not on list... no more business here */
 259                 goto bail;
 260         }
 261         /* we did have an ah attached */
 262         time(&now);
 263         if (ah->assigned && now - ah->assigned > 3) {
 264                 /*
 265                  * we're detaching the ah, but it was held an
 266                  * unreasonably long time
 267                  */
 268                 lwsl_notice("%s: wsi %p: ah held %ds, "
 269                             "ah.rxpos %d, ah.rxlen %d, mode/state %d %d,"
 270                             "wsi->more_rx_waiting %d\n", __func__, wsi,
 271                             (int)(now - ah->assigned),
 272                             ah->rxpos, ah->rxlen, wsi->mode, wsi->state,
 273                             wsi->more_rx_waiting);
 274         }
 275
 276         ah->assigned = 0;
 277
 278         /* if we think we're detaching one, there should be one in use */
 279         assert(pt->ah_count_in_use > 0);
 280         /* and this specific one should have been in use */
 281         assert(ah->in_use);
 282         wsi->u.hdr.ah = NULL;
 283         ah->wsi = NULL; /* no owner */
 284
 285         /* oh there is nobody on the waiting list... leave it at that then */
 286         if (!*pwsi) {
 287                 ah->in_use = 0;
 288                 pt->ah_count_in_use--;
 289
 290                 goto bail;
 291         }
 292
 293         /* somebody else on same tsi is waiting, give it to oldest guy */
 294
 295         lwsl_info("pt wait list %p\n", *pwsi);
 296         while ((*pwsi)->u.hdr.ah_wait_list)
 297                 pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 298
 299         wsi = *pwsi;
 300         lwsl_info("last wsi in wait list %p\n", wsi);
 301
 302         wsi->u.hdr.ah = ah;
 303         ah->wsi = wsi; /* new owner */
 304         /* and reset the rx state */
 305         ah->rxpos = 0;
 306         ah->rxlen = 0;
 307         lws_header_table_reset(wsi, autoservice);
 308         time(&wsi->u.hdr.ah->assigned);
 309
 310         /* clients acquire the ah and then insert themselves in fds table... */
 311         if (wsi->position_in_fds_table != -1) {
 312                 lwsl_info("%s: Enabling %p POLLIN\n", __func__, wsi);
 313
 314                 /* he has been stuck waiting for an ah, but now his wait is over,
 315                  * let him progress
 316                  */
 317                 _lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
 318         }
 319
 320         /* point prev guy to next guy in list instead */
 321         *pwsi = wsi->u.hdr.ah_wait_list;
 322         /* the guy who got one is out of the list */
 323         wsi->u.hdr.ah_wait_list = NULL;
 324         pt->ah_wait_list_length--;
 325
 326 #ifndef LWS_NO_CLIENT
 327         if (wsi->state == LWSS_CLIENT_UNCONNECTED) {
 328                 lws_pt_unlock(pt);
 329
 330                 if (!lws_client_connect_via_info2(wsi)) {
 331                         /* our client connect has failed, the wsi
 332                          * has been closed
 333                          */
 334
 335                         return -1;
 336                 }
 337                 return 0;
 338         }
 339 #endif
 340
 341         assert(!!pt->ah_wait_list_length == !!(int)(long)pt->ah_wait_list);
 342 bail:
 343         lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
 344           (void *)wsi, (void *)ah, wsi->tsi,
 345           pt->ah_count_in_use);
 346         lws_pt_unlock(pt);
 347
 348         return 0;
 349 }
 350
 351 LWS_VISIBLE int
 352 lws_hdr_fragment_length(struct lws *wsi, enum lws_token_indexes h, int frag_idx)
 353 {
 354         int n;
 355
 356         n = wsi->u.hdr.ah->frag_index[h];
 357         if (!n)
 358                 return 0;
 359         do {
 360                 if (!frag_idx)
 361                         return wsi->u.hdr.ah->frags[n].len;
 362                 n = wsi->u.hdr.ah->frags[n].nfrag;
 363         } while (frag_idx-- && n);
 364
 365         return 0;
 366 }
 367
 368 LWS_VISIBLE int lws_hdr_total_length(struct lws *wsi, enum lws_token_indexes h)
 369 {
 370         int n;
 371         int len = 0;
 372
 373         n = wsi->u.hdr.ah->frag_index[h];
 374         if (!n)
 375                 return 0;
 376         do {
 377                 len += wsi->u.hdr.ah->frags[n].len;
 378                 n = wsi->u.hdr.ah->frags[n].nfrag;
 379         } while (n);
 380
 381         return len;
 382 }
 383
 384 LWS_VISIBLE int lws_hdr_copy_fragment(struct lws *wsi, char *dst, int len,
 385                                       enum lws_token_indexes h, int frag_idx)
 386 {
 387         int n = 0;
 388         int f = wsi->u.hdr.ah->frag_index[h];
 389
 390         if (!f)
 391                 return -1;
 392
 393         while (n < frag_idx) {
 394                 f = wsi->u.hdr.ah->frags[f].nfrag;
 395                 if (!f)
 396                         return -1;
 397                 n++;
 398         }
 399
 400         if (wsi->u.hdr.ah->frags[f].len >= len)
 401                 return -1;
 402
 403         memcpy(dst, wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[f].offset,
 404                wsi->u.hdr.ah->frags[f].len);
 405         dst[wsi->u.hdr.ah->frags[f].len] = '\0';
 406
 407         return wsi->u.hdr.ah->frags[f].len;
 408 }
 409
 410 LWS_VISIBLE int lws_hdr_copy(struct lws *wsi, char *dst, int len,
 411                              enum lws_token_indexes h)
 412 {
 413         int toklen = lws_hdr_total_length(wsi, h);
 414         int n;
 415
 416         if (toklen >= len)
 417                 return -1;
 418
 419         n = wsi->u.hdr.ah->frag_index[h];
 420         if (!n)
 421                 return 0;
 422
 423         do {
 424                 strcpy(dst, &wsi->u.hdr.ah->data[wsi->u.hdr.ah->frags[n].offset]);
 425                 dst += wsi->u.hdr.ah->frags[n].len;
 426                 n = wsi->u.hdr.ah->frags[n].nfrag;
 427         } while (n);
 428
 429         return toklen;
 430 }
 431
 432 char *lws_hdr_simple_ptr(struct lws *wsi, enum lws_token_indexes h)
 433 {
 434         int n;
 435
 436         n = wsi->u.hdr.ah->frag_index[h];
 437         if (!n)
 438                 return NULL;
 439
 440         return wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[n].offset;
 441 }
 442
 443 int LWS_WARN_UNUSED_RESULT
 444 lws_pos_in_bounds(struct lws *wsi)
 445 {
 446         if (wsi->u.hdr.ah->pos < (unsigned int)wsi->context->max_http_header_data)
 447                 return 0;
 448
 449         if (wsi->u.hdr.ah->pos == wsi->context->max_http_header_data) {
 450                 lwsl_err("Ran out of header data space\n");
 451                 return 1;
 452         }
 453
 454         /*
 455          * with these tests everywhere, it should never be able to exceed
 456          * the limit, only meet the limit
 457          */
 458
 459         lwsl_err("%s: pos %d, limit %d\n", __func__, wsi->u.hdr.ah->pos,
 460                  wsi->context->max_http_header_data);
 461         assert(0);
 462
 463         return 1;
 464 }
 465
 466 int LWS_WARN_UNUSED_RESULT
 467 lws_hdr_simple_create(struct lws *wsi, enum lws_token_indexes h, const char *s)
 468 {
 469         wsi->u.hdr.ah->nfrag++;
 470         if (wsi->u.hdr.ah->nfrag == ARRAY_SIZE(wsi->u.hdr.ah->frags)) {
 471                 lwsl_warn("More hdr frags than we can deal with, dropping\n");
 472                 return -1;
 473         }
 474
 475         wsi->u.hdr.ah->frag_index[h] = wsi->u.hdr.ah->nfrag;
 476
 477         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].offset = wsi->u.hdr.ah->pos;
 478         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len = 0;
 479         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].nfrag = 0;
 480
 481         do {
 482                 if (lws_pos_in_bounds(wsi))
 483                         return -1;
 484
 485                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = *s;
 486                 if (*s)
 487                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 488         } while (*s++);
 489
 490         return 0;
 491 }
 492
 493 signed char char_to_hex(const char c)
 494 {
 495         if (c >= '0' && c <= '9')
 496                 return c - '0';
 497
 498         if (c >= 'a' && c <= 'f')
 499                 return c - 'a' + 10;
 500
 501         if (c >= 'A' && c <= 'F')
 502                 return c - 'A' + 10;
 503
 504         return -1;
 505 }
 506
 507 static int LWS_WARN_UNUSED_RESULT
 508 issue_char(struct lws *wsi, unsigned char c)
 509 {
 510         unsigned short frag_len;
 511
 512         if (lws_pos_in_bounds(wsi))
 513                 return -1;
 514
 515         frag_len = wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len;
 516         /*
 517          * If we haven't hit the token limit, just copy the character into
 518          * the header
 519          */
 520         if (frag_len < wsi->u.hdr.current_token_limit) {
 521                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = c;
 522                 if (c)
 523                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 524                 return 0;
 525         }
 526
 527         /* Insert a null character when we *hit* the limit: */
 528         if (frag_len == wsi->u.hdr.current_token_limit) {
 529                 if (lws_pos_in_bounds(wsi))
 530                         return -1;
 531                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = '\0';
 532                 lwsl_warn("header %i exceeds limit %d\n",
 533                           wsi->u.hdr.parser_state,
 534                           wsi->u.hdr.current_token_limit);
 535         }
 536
 537         return 1;
 538 }
 539
 540 int LWS_WARN_UNUSED_RESULT
 541 lws_parse(struct lws *wsi, unsigned char c)
 542 {
 543         static const unsigned char methods[] = {
 544                 WSI_TOKEN_GET_URI,
 545                 WSI_TOKEN_POST_URI,
 546                 WSI_TOKEN_OPTIONS_URI,
 547                 WSI_TOKEN_PUT_URI,
 548                 WSI_TOKEN_PATCH_URI,
 549                 WSI_TOKEN_DELETE_URI,
 550                 WSI_TOKEN_CONNECT,
 551         };
 552         struct allocated_headers *ah = wsi->u.hdr.ah;
 553         struct lws_context *context = wsi->context;
 554         unsigned int n, m, enc = 0;
 555
 556         assert(wsi->u.hdr.ah);
 557
 558         switch (wsi->u.hdr.parser_state) {
 559         default:
 560
 561                 lwsl_parser("WSI_TOK_(%d) '%c'\n", wsi->u.hdr.parser_state, c);
 562
 563                 /* collect into malloc'd buffers */
 564                 /* optional initial space swallow */
 565                 if (!ah->frags[ah->frag_index[wsi->u.hdr.parser_state]].len &&
 566                     c == ' ')
 567                         break;
 568
 569                 for (m = 0; m < ARRAY_SIZE(methods); m++)
 570                         if (wsi->u.hdr.parser_state == methods[m])
 571                                 break;
 572                 if (m == ARRAY_SIZE(methods))
 573                         /* it was not any of the methods */
 574                         goto check_eol;
 575
 576                 /* special URI processing... end at space */
 577
 578                 if (c == ' ') {
 579                         /* enforce starting with / */
 580                         if (!ah->frags[ah->nfrag].len)
 581                                 if (issue_char(wsi, '/') < 0)
 582                                         return -1;
 583
 584                         if (wsi->u.hdr.ups == URIPS_SEEN_SLASH_DOT_DOT) {
 585                                 /*
 586                                  * back up one dir level if possible
 587                                  * safe against header fragmentation because
 588                                  * the method URI can only be in 1 fragment
 589                                  */
 590                                 if (ah->frags[ah->nfrag].len > 2) {
 591                                         ah->pos--;
 592                                         ah->frags[ah->nfrag].len--;
 593                                         do {
 594                                                 ah->pos--;
 595                                                 ah->frags[ah->nfrag].len--;
 596                                         } while (ah->frags[ah->nfrag].len > 1 &&
 597                                                  ah->data[ah->pos] != '/');
 598                                 }
 599                         }
 600
 601                         /* begin parsing HTTP version: */
 602                         if (issue_char(wsi, '\0') < 0)
 603                                 return -1;
 604                         wsi->u.hdr.parser_state = WSI_TOKEN_HTTP;
 605                         goto start_fragment;
 606                 }
 607
 608                 /*
 609                  * PRIORITY 1
 610                  * special URI processing... convert %xx
 611                  */
 612
 613                 switch (wsi->u.hdr.ues) {
 614                 case URIES_IDLE:
 615                         if (c == '%') {
 616                                 wsi->u.hdr.ues = URIES_SEEN_PERCENT;
 617                                 goto swallow;
 618                         }
 619                         break;
 620                 case URIES_SEEN_PERCENT:
 621                         if (char_to_hex(c) < 0)
 622                                 /* illegal post-% char */
 623                                 goto forbid;
 624
 625                         wsi->u.hdr.esc_stash = c;
 626                         wsi->u.hdr.ues = URIES_SEEN_PERCENT_H1;
 627                         goto swallow;
 628
 629                 case URIES_SEEN_PERCENT_H1:
 630                         if (char_to_hex(c) < 0)
 631                                 /* illegal post-% char */
 632                                 goto forbid;
 633
 634                         c = (char_to_hex(wsi->u.hdr.esc_stash) << 4) |
 635                                         char_to_hex(c);
 636                         enc = 1;
 637                         wsi->u.hdr.ues = URIES_IDLE;
 638                         break;
 639                 }
 640
 641                 /*
 642                  * PRIORITY 2
 643                  * special URI processing...
 644                  *  convert /.. or /... or /../ etc to /
 645                  *  convert /./ to /
 646                  *  convert // or /// etc to /
 647                  *  leave /.dir or whatever alone
 648                  */
 649
 650                 switch (wsi->u.hdr.ups) {
 651                 case URIPS_IDLE:
 652                         if (!c)
 653                                 return -1;
 654                         /* genuine delimiter */
 655                         if ((c == '&' || c == ';') && !enc) {
 656                                 if (issue_char(wsi, c) < 0)
 657                                         return -1;
 658                                 /* swallow the terminator */
 659                                 ah->frags[ah->nfrag].len--;
 660                                 /* link to next fragment */
 661                                 ah->frags[ah->nfrag].nfrag = ah->nfrag + 1;
 662                                 ah->nfrag++;
 663                                 if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 664                                         goto excessive;
 665                                 /* start next fragment after the & */
 666                                 wsi->u.hdr.post_literal_equal = 0;
 667                                 ah->frags[ah->nfrag].offset = ah->pos;
 668                                 ah->frags[ah->nfrag].len = 0;
 669                                 ah->frags[ah->nfrag].nfrag = 0;
 670                                 goto swallow;
 671                         }
 672                         /* uriencoded = in the name part, disallow */
 673                         if (c == '=' && enc &&
 674                             ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] &&
 675                             !wsi->u.hdr.post_literal_equal)
 676                                 c = '_';
 677
 678                         /* after the real =, we don't care how many = */
 679                         if (c == '=' && !enc)
 680                                 wsi->u.hdr.post_literal_equal = 1;
 681
 682                         /* + to space */
 683                         if (c == '+' && !enc)
 684                                 c = ' ';
 685                         /* issue the first / always */
 686                         if (c == '/' && !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS])
 687                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 688                         break;
 689                 case URIPS_SEEN_SLASH:
 690                         /* swallow subsequent slashes */
 691                         if (c == '/')
 692                                 goto swallow;
 693                         /* track and swallow the first . after / */
 694                         if (c == '.') {
 695                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT;
 696                                 goto swallow;
 697                         }
 698                         wsi->u.hdr.ups = URIPS_IDLE;
 699                         break;
 700                 case URIPS_SEEN_SLASH_DOT:
 701                         /* swallow second . */
 702                         if (c == '.') {
 703                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT_DOT;
 704                                 goto swallow;
 705                         }
 706                         /* change /./ to / */
 707                         if (c == '/') {
 708                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 709                                 goto swallow;
 710                         }
 711                         /* it was like /.dir ... regurgitate the . */
 712                         wsi->u.hdr.ups = URIPS_IDLE;
 713                         if (issue_char(wsi, '.') < 0)
 714                                 return -1;
 715                         break;
 716
 717                 case URIPS_SEEN_SLASH_DOT_DOT:
 718
 719                         /* /../ or /..[End of URI] --> backup to last / */
 720                         if (c == '/' || c == '?') {
 721                                 /*
 722                                  * back up one dir level if possible
 723                                  * safe against header fragmentation because
 724                                  * the method URI can only be in 1 fragment
 725                                  */
 726                                 if (ah->frags[ah->nfrag].len > 2) {
 727                                         ah->pos--;
 728                                         ah->frags[ah->nfrag].len--;
 729                                         do {
 730                                                 ah->pos--;
 731                                                 ah->frags[ah->nfrag].len--;
 732                                         } while (ah->frags[ah->nfrag].len > 1 &&
 733                                                  ah->data[ah->pos] != '/');
 734                                 }
 735                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 736                                 if (ah->frags[ah->nfrag].len > 1)
 737                                         break;
 738                                 goto swallow;
 739                         }
 740
 741                         /*  /..[^/] ... regurgitate and allow */
 742
 743                         if (issue_char(wsi, '.') < 0)
 744                                 return -1;
 745                         if (issue_char(wsi, '.') < 0)
 746                                 return -1;
 747                         wsi->u.hdr.ups = URIPS_IDLE;
 748                         break;
 749                 }
 750
 751                 if (c == '?' && !enc &&
 752                     !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS]) { /* start of URI arguments */
 753                         if (wsi->u.hdr.ues != URIES_IDLE)
 754                                 goto forbid;
 755
 756                         /* seal off uri header */
 757                         if (issue_char(wsi, '\0') < 0)
 758                                 return -1;
 759
 760                         /* move to using WSI_TOKEN_HTTP_URI_ARGS */
 761                         ah->nfrag++;
 762                         if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 763                                 goto excessive;
 764                         ah->frags[ah->nfrag].offset = ah->pos;
 765                         ah->frags[ah->nfrag].len = 0;
 766                         ah->frags[ah->nfrag].nfrag = 0;
 767
 768                         wsi->u.hdr.post_literal_equal = 0;
 769                         ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] = ah->nfrag;
 770                         wsi->u.hdr.ups = URIPS_IDLE;
 771                         goto swallow;
 772                 }
 773
 774 check_eol:
 775                 /* bail at EOL */
 776                 if (wsi->u.hdr.parser_state != WSI_TOKEN_CHALLENGE &&
 777                     c == '\x0d') {
 778                         if (wsi->u.hdr.ues != URIES_IDLE)
 779                                 goto forbid;
 780
 781                         c = '\0';
 782                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 783                         lwsl_parser("*\n");
 784                 }
 785
 786                 n = issue_char(wsi, c);
 787                 if ((int)n < 0)
 788                         return -1;
 789                 if (n > 0)
 790                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 791
 792 swallow:
 793                 /* per-protocol end of headers management */
 794
 795                 if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 796                         goto set_parsing_complete;
 797                 break;
 798
 799                 /* collecting and checking a name part */
 800         case WSI_TOKEN_NAME_PART:
 801                 lwsl_parser("WSI_TOKEN_NAME_PART '%c' (mode=%d)\n", c, wsi->mode);
 802
 803                 wsi->u.hdr.lextable_pos =
 804                                 lextable_decode(wsi->u.hdr.lextable_pos, c);
 805                 /*
 806                  * Server needs to look out for unknown methods...
 807                  */
 808                 if (wsi->u.hdr.lextable_pos < 0 &&
 809                     wsi->mode == LWSCM_HTTP_SERVING) {
 810                         /* this is not a header we know about */
 811                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 812                                 if (ah->frag_index[methods[m]]) {
 813                                         /*
 814                                          * already had the method, no idea what
 815                                          * this crap from the client is, ignore
 816                                          */
 817                                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 818                                         break;
 819                                 }
 820                         /*
 821                          * hm it's an unknown http method from a client in fact,
 822                          * it cannot be valid http
 823                          */
 824                         if (m == ARRAY_SIZE(methods)) {
 825                                 /*
 826                                  * are we set up to accept raw in these cases?
 827                                  */
 828                                 if (lws_check_opt(wsi->vhost->options,
 829                                            LWS_SERVER_OPTION_FALLBACK_TO_RAW))
 830                                         return 2; /* transition to raw */
 831
 832                                 lwsl_info("Unknown method - dropping\n");
 833                                 goto forbid;
 834                         }
 835                         break;
 836                 }
 837                 /*
 838                  * ...otherwise for a client, let him ignore unknown headers
 839                  * coming from the server
 840                  */
 841                 if (wsi->u.hdr.lextable_pos < 0) {
 842                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 843                         break;
 844                 }
 845
 846                 if (lextable[wsi->u.hdr.lextable_pos] < FAIL_CHAR) {
 847                         /* terminal state */
 848
 849                         n = ((unsigned int)lextable[wsi->u.hdr.lextable_pos] << 8) |
 850                                         lextable[wsi->u.hdr.lextable_pos + 1];
 851
 852                         lwsl_parser("known hdr %d\n", n);
 853                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 854                                 if (n == methods[m] &&
 855                                     ah->frag_index[methods[m]]) {
 856                                         lwsl_warn("Duplicated method\n");
 857                                         return -1;
 858                                 }
 859
 860                         /*
 861                          * WSORIGIN is protocol equiv to ORIGIN,
 862                          * JWebSocket likes to send it, map to ORIGIN
 863                          */
 864                         if (n == WSI_TOKEN_SWORIGIN)
 865                                 n = WSI_TOKEN_ORIGIN;
 866
 867                         wsi->u.hdr.parser_state = (enum lws_token_indexes)
 868                                                         (WSI_TOKEN_GET_URI + n);
 869
 870                         if (context->token_limits)
 871                                 wsi->u.hdr.current_token_limit =
 872                                         context->token_limits->token_limit[
 873                                                        wsi->u.hdr.parser_state];
 874                         else
 875                                 wsi->u.hdr.current_token_limit =
 876                                         wsi->context->max_http_header_data;
 877
 878                         if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 879                                 goto set_parsing_complete;
 880
 881                         goto start_fragment;
 882                 }
 883                 break;
 884
 885 start_fragment:
 886                 ah->nfrag++;
 887 excessive:
 888                 if (ah->nfrag == ARRAY_SIZE(ah->frags)) {
 889                         lwsl_warn("More hdr frags than we can deal with\n");
 890                         return -1;
 891                 }
 892
 893                 ah->frags[ah->nfrag].offset = ah->pos;
 894                 ah->frags[ah->nfrag].len = 0;
 895                 ah->frags[ah->nfrag].nfrag = 0;
 896
 897                 n = ah->frag_index[wsi->u.hdr.parser_state];
 898                 if (!n) { /* first fragment */
 899                         ah->frag_index[wsi->u.hdr.parser_state] = ah->nfrag;
 900                         break;
 901                 }
 902                 /* continuation */
 903                 while (ah->frags[n].nfrag)
 904                         n = ah->frags[n].nfrag;
 905                 ah->frags[n].nfrag = ah->nfrag;
 906
 907                 if (issue_char(wsi, ' ') < 0)
 908                         return -1;
 909                 break;
 910
 911                 /* skipping arg part of a name we didn't recognize */
 912         case WSI_TOKEN_SKIPPING:
 913                 lwsl_parser("WSI_TOKEN_SKIPPING '%c'\n", c);
 914
 915                 if (c == '\x0d')
 916                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 917                 break;
 918
 919         case WSI_TOKEN_SKIPPING_SAW_CR:
 920                 lwsl_parser("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
 921                 if (wsi->u.hdr.ues != URIES_IDLE)
 922                         goto forbid;
 923                 if (c == '\x0a') {
 924                         wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 925                         wsi->u.hdr.lextable_pos = 0;
 926                 } else
 927                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 928                 break;
 929                 /* we're done, ignore anything else */
 930
 931         case WSI_PARSING_COMPLETE:
 932                 lwsl_parser("WSI_PARSING_COMPLETE '%c'\n", c);
 933                 break;
 934         }
 935
 936         return 0;
 937
 938 set_parsing_complete:
 939         if (wsi->u.hdr.ues != URIES_IDLE)
 940                 goto forbid;
 941         if (lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE)) {
 942                 if (lws_hdr_total_length(wsi, WSI_TOKEN_VERSION))
 943                         wsi->ietf_spec_revision =
 944                                atoi(lws_hdr_simple_ptr(wsi, WSI_TOKEN_VERSION));
 945
 946                 lwsl_parser("v%02d hdrs completed\n", wsi->ietf_spec_revision);
 947         }
 948         wsi->u.hdr.parser_state = WSI_PARSING_COMPLETE;
 949         wsi->hdr_parsing_completed = 1;
 950
 951         return 0;
 952
 953 forbid:
 954         lwsl_notice(" forbidding on uri sanitation\n");
 955         lws_return_http_status(wsi, HTTP_STATUS_FORBIDDEN, NULL);
 956         return -1;
 957 }
 958
 959 LWS_VISIBLE int lws_frame_is_binary(struct lws *wsi)
 960 {
 961         return wsi->u.ws.frame_is_binary;
 962 }
 963
 964 void
 965 lws_add_wsi_to_draining_ext_list(struct lws *wsi)
 966 {
 967         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 968
 969         if (wsi->u.ws.rx_draining_ext)
 970                 return;
 971
 972         lwsl_ext("%s: RX EXT DRAINING: Adding to list\n", __func__);
 973
 974         wsi->u.ws.rx_draining_ext = 1;
 975         wsi->u.ws.rx_draining_ext_list = pt->rx_draining_ext_list;
 976         pt->rx_draining_ext_list = wsi;
 977 }
 978
 979 void
 980 lws_remove_wsi_from_draining_ext_list(struct lws *wsi)
 981 {
 982         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 983         struct lws **w = &pt->rx_draining_ext_list;
 984
 985         if (!wsi->u.ws.rx_draining_ext)
 986                 return;
 987
 988         lwsl_ext("%s: RX EXT DRAINING: Removing from list\n", __func__);
 989
 990         wsi->u.ws.rx_draining_ext = 0;
 991
 992         /* remove us from context draining ext list */
 993         while (*w) {
 994                 if (*w == wsi) {
 995                         /* if us, point it instead to who we were pointing to */
 996                         *w = wsi->u.ws.rx_draining_ext_list;
 997                         break;
 998                 }
 999                 w = &((*w)->u.ws.rx_draining_ext_list);
1000         }
1001         wsi->u.ws.rx_draining_ext_list = NULL;
1002 }
1003
1004 /*
1005  * client-parser.c: lws_client_rx_sm() needs to be roughly kept in
1006  *   sync with changes here, esp related to ext draining
1007  */
1008
1009 int
1010 lws_rx_sm(struct lws *wsi, unsigned char c)
1011 {
1012         int callback_action = LWS_CALLBACK_RECEIVE;
1013         int ret = 0, n, rx_draining_ext = 0;
1014         struct lws_tokens eff_buf;
1015
1016         eff_buf.token = NULL;
1017         eff_buf.token_len = 0;
1018         if (wsi->socket_is_permanently_unusable)
1019                 return -1;
1020
1021         switch (wsi->lws_rx_parse_state) {
1022         case LWS_RXPS_NEW:
1023                 if (wsi->u.ws.rx_draining_ext) {
1024                         eff_buf.token = NULL;
1025                         eff_buf.token_len = 0;
1026                         lws_remove_wsi_from_draining_ext_list(wsi);
1027                         rx_draining_ext = 1;
1028                         lwsl_debug("%s: doing draining flow\n", __func__);
1029
1030                         goto drain_extension;
1031                 }
1032                 switch (wsi->ietf_spec_revision) {
1033                 case 13:
1034                         /*
1035                          * no prepended frame key any more
1036                          */
1037                         wsi->u.ws.all_zero_nonce = 1;
1038                         goto handle_first;
1039
1040                 default:
1041                         lwsl_warn("lws_rx_sm: unknown spec version %d\n",
1042                                                        wsi->ietf_spec_revision);
1043                         break;
1044                 }
1045                 break;
1046         case LWS_RXPS_04_mask_1:
1047                 wsi->u.ws.mask[1] = c;
1048                 if (c)
1049                         wsi->u.ws.all_zero_nonce = 0;
1050                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_2;
1051                 break;
1052         case LWS_RXPS_04_mask_2:
1053                 wsi->u.ws.mask[2] = c;
1054                 if (c)
1055                         wsi->u.ws.all_zero_nonce = 0;
1056                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_3;
1057                 break;
1058         case LWS_RXPS_04_mask_3:
1059                 wsi->u.ws.mask[3] = c;
1060                 if (c)
1061                         wsi->u.ws.all_zero_nonce = 0;
1062
1063                 /*
1064                  * start from the zero'th byte in the XOR key buffer since
1065                  * this is the start of a frame with a new key
1066                  */
1067
1068                 wsi->u.ws.mask_idx = 0;
1069
1070                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_1;
1071                 break;
1072
1073         /*
1074          *  04 logical framing from the spec (all this is masked when incoming
1075          *  and has to be unmasked)
1076          *
1077          * We ignore the possibility of extension data because we don't
1078          * negotiate any extensions at the moment.
1079          *
1080          *    0                   1                   2                   3
1081          *    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
1082          *   +-+-+-+-+-------+-+-------------+-------------------------------+
1083          *   |F|R|R|R| opcode|R| Payload len |    Extended payload length    |
1084          *   |I|S|S|S|  (4)  |S|     (7)     |             (16/63)           |
1085          *   |N|V|V|V|       |V|             |   (if payload len==126/127)   |
1086          *   | |1|2|3|       |4|             |                               |
1087          *   +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
1088          *   |     Extended payload length continued, if payload len == 127  |
1089          *   + - - - - - - - - - - - - - - - +-------------------------------+
1090          *   |                               |         Extension data        |
1091          *   +-------------------------------+ - - - - - - - - - - - - - - - +
1092          *   :                                                               :
1093          *   +---------------------------------------------------------------+
1094          *   :                       Application data                        :
1095          *   +---------------------------------------------------------------+
1096          *
1097          *  We pass payload through to userland as soon as we get it, ignoring
1098          *  FIN.  It's up to userland to buffer it up if it wants to see a
1099          *  whole unfragmented block of the original size (which may be up to
1100          *  2^63 long!)
1101          */
1102
1103         case LWS_RXPS_04_FRAME_HDR_1:
1104 handle_first:
1105
1106                 wsi->u.ws.opcode = c & 0xf;
1107                 wsi->u.ws.rsv = c & 0x70;
1108                 wsi->u.ws.final = !!((c >> 7) & 1);
1109
1110                 switch (wsi->u.ws.opcode) {
1111                 case LWSWSOPC_TEXT_FRAME:
1112                 case LWSWSOPC_BINARY_FRAME:
1113                         wsi->u.ws.rsv_first_msg = (c & 0x70);
1114                         wsi->u.ws.frame_is_binary =
1115                              wsi->u.ws.opcode == LWSWSOPC_BINARY_FRAME;
1116                         break;
1117                 case 3:
1118                 case 4:
1119                 case 5:
1120                 case 6:
1121                 case 7:
1122                 case 0xb:
1123                 case 0xc:
1124                 case 0xd:
1125                 case 0xe:
1126                 case 0xf:
1127                         lwsl_info("illegal opcode\n");
1128                         return -1;
1129                 }
1130                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
1131                 break;
1132
1133         case LWS_RXPS_04_FRAME_HDR_LEN:
1134
1135                 wsi->u.ws.this_frame_masked = !!(c & 0x80);
1136
1137                 switch (c & 0x7f) {
1138                 case 126:
1139                         /* control frames are not allowed to have big lengths */
1140                         if (wsi->u.ws.opcode & 8)
1141                                 goto illegal_ctl_length;
1142
1143                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
1144                         break;
1145                 case 127:
1146                         /* control frames are not allowed to have big lengths */
1147                         if (wsi->u.ws.opcode & 8)
1148                                 goto illegal_ctl_length;
1149
1150                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
1151                         break;
1152                 default:
1153                         wsi->u.ws.rx_packet_length = c & 0x7f;
1154                         if (wsi->u.ws.this_frame_masked)
1155                                 wsi->lws_rx_parse_state =
1156                                                 LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1157                         else
1158                                 if (wsi->u.ws.rx_packet_length)
1159                                         wsi->lws_rx_parse_state =
1160                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1161                                 else {
1162                                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1163                                         goto spill;
1164                                 }
1165                         break;
1166                 }
1167                 break;
1168
1169         case LWS_RXPS_04_FRAME_HDR_LEN16_2:
1170                 wsi->u.ws.rx_packet_length = c << 8;
1171                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
1172                 break;
1173
1174         case LWS_RXPS_04_FRAME_HDR_LEN16_1:
1175                 wsi->u.ws.rx_packet_length |= c;
1176                 if (wsi->u.ws.this_frame_masked)
1177                         wsi->lws_rx_parse_state =
1178                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1179                 else
1180                         wsi->lws_rx_parse_state =
1181                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1182                 break;
1183
1184         case LWS_RXPS_04_FRAME_HDR_LEN64_8:
1185                 if (c & 0x80) {
1186                         lwsl_warn("b63 of length must be zero\n");
1187                         /* kill the connection */
1188                         return -1;
1189                 }
1190 #if defined __LP64__
1191                 wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
1192 #else
1193                 wsi->u.ws.rx_packet_length = 0;
1194 #endif
1195                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
1196                 break;
1197
1198         case LWS_RXPS_04_FRAME_HDR_LEN64_7:
1199 #if defined __LP64__
1200                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
1201 #endif
1202                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
1203                 break;
1204
1205         case LWS_RXPS_04_FRAME_HDR_LEN64_6:
1206 #if defined __LP64__
1207                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
1208 #endif
1209                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
1210                 break;
1211
1212         case LWS_RXPS_04_FRAME_HDR_LEN64_5:
1213 #if defined __LP64__
1214                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
1215 #endif
1216                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
1217                 break;
1218
1219         case LWS_RXPS_04_FRAME_HDR_LEN64_4:
1220                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
1221                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
1222                 break;
1223
1224         case LWS_RXPS_04_FRAME_HDR_LEN64_3:
1225                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
1226                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
1227                 break;
1228
1229         case LWS_RXPS_04_FRAME_HDR_LEN64_2:
1230                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
1231                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
1232                 break;
1233
1234         case LWS_RXPS_04_FRAME_HDR_LEN64_1:
1235                 wsi->u.ws.rx_packet_length |= ((size_t)c);
1236                 if (wsi->u.ws.this_frame_masked)
1237                         wsi->lws_rx_parse_state =
1238                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1239                 else
1240                         wsi->lws_rx_parse_state =
1241                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1242                 break;
1243
1244         case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
1245                 wsi->u.ws.mask[0] = c;
1246                 if (c)
1247                         wsi->u.ws.all_zero_nonce = 0;
1248                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
1249                 break;
1250
1251         case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
1252                 wsi->u.ws.mask[1] = c;
1253                 if (c)
1254                         wsi->u.ws.all_zero_nonce = 0;
1255                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
1256                 break;
1257
1258         case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
1259                 wsi->u.ws.mask[2] = c;
1260                 if (c)
1261                         wsi->u.ws.all_zero_nonce = 0;
1262                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
1263                 break;
1264
1265         case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
1266                 wsi->u.ws.mask[3] = c;
1267                 if (c)
1268                         wsi->u.ws.all_zero_nonce = 0;
1269                 wsi->lws_rx_parse_state =
1270                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1271                 wsi->u.ws.mask_idx = 0;
1272                 if (wsi->u.ws.rx_packet_length == 0) {
1273                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1274                         goto spill;
1275                 }
1276                 break;
1277
1278
1279         case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
1280                 assert(wsi->u.ws.rx_ubuf);
1281
1282                 if (wsi->u.ws.rx_draining_ext)
1283                         goto drain_extension;
1284
1285                 if (wsi->u.ws.rx_ubuf_head + LWS_PRE >=
1286                     wsi->u.ws.rx_ubuf_alloc) {
1287                         lwsl_err("Attempted overflow \n");
1288                         return -1;
1289                 }
1290                 if (wsi->u.ws.all_zero_nonce)
1291                         wsi->u.ws.rx_ubuf[LWS_PRE +
1292                                          (wsi->u.ws.rx_ubuf_head++)] = c;
1293                 else
1294                         wsi->u.ws.rx_ubuf[LWS_PRE +
1295                                (wsi->u.ws.rx_ubuf_head++)] =
1296                                    c ^ wsi->u.ws.mask[
1297                                             (wsi->u.ws.mask_idx++) & 3];
1298
1299                 if (--wsi->u.ws.rx_packet_length == 0) {
1300                         /* spill because we have the whole frame */
1301                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1302                         goto spill;
1303                 }
1304
1305                 /*
1306                  * if there's no protocol max frame size given, we are
1307                  * supposed to default to context->pt_serv_buf_size
1308                  */
1309
1310                 if (!wsi->protocol->rx_buffer_size &&
1311                     wsi->u.ws.rx_ubuf_head != wsi->context->pt_serv_buf_size)
1312                         break;
1313                 else
1314                         if (wsi->protocol->rx_buffer_size &&
1315                                         wsi->u.ws.rx_ubuf_head !=
1316                                                   wsi->protocol->rx_buffer_size)
1317                         break;
1318
1319                 /* spill because we filled our rx buffer */
1320 spill:
1321                 /*
1322                  * is this frame a control packet we should take care of at this
1323                  * layer?  If so service it and hide it from the user callback
1324                  */
1325
1326                 lwsl_parser("spill on %s\n", wsi->protocol->name);
1327
1328                 switch (wsi->u.ws.opcode) {
1329                 case LWSWSOPC_CLOSE:
1330
1331                         /* is this an acknowledgement of our close? */
1332                         if (wsi->state == LWSS_AWAITING_CLOSE_ACK) {
1333                                 /*
1334                                  * fine he has told us he is closing too, let's
1335                                  * finish our close
1336                                  */
1337                                 lwsl_parser("seen client close ack\n");
1338                                 return -1;
1339                         }
1340                         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
1341                                 /* if he sends us 2 CLOSE, kill him */
1342                                 return -1;
1343
1344                         if (lws_partial_buffered(wsi)) {
1345                                 /*
1346                                  * if we're in the middle of something,
1347                                  * we can't do a normal close response and
1348                                  * have to just close our end.
1349                                  */
1350                                 wsi->socket_is_permanently_unusable = 1;
1351                                 lwsl_parser("Closing on peer close due to Pending tx\n");
1352                                 return -1;
1353                         }
1354
1355                         if (user_callback_handle_rxflow(
1356                                         wsi->protocol->callback, wsi,
1357                                         LWS_CALLBACK_WS_PEER_INITIATED_CLOSE,
1358                                         wsi->user_space,
1359                                         &wsi->u.ws.rx_ubuf[LWS_PRE],
1360                                         wsi->u.ws.rx_ubuf_head))
1361                                 return -1;
1362
1363                         lwsl_parser("server sees client close packet\n");
1364                         wsi->state = LWSS_RETURNED_CLOSE_ALREADY;
1365                         /* deal with the close packet contents as a PONG */
1366                         wsi->u.ws.payload_is_close = 1;
1367                         goto process_as_ping;
1368
1369                 case LWSWSOPC_PING:
1370                         lwsl_info("received %d byte ping, sending pong\n",
1371                                                  wsi->u.ws.rx_ubuf_head);
1372
1373                         if (wsi->u.ws.ping_pending_flag) {
1374                                 /*
1375                                  * there is already a pending ping payload
1376                                  * we should just log and drop
1377                                  */
1378                                 lwsl_parser("DROP PING since one pending\n");
1379                                 goto ping_drop;
1380                         }
1381 process_as_ping:
1382                         /* control packets can only be < 128 bytes long */
1383                         if (wsi->u.ws.rx_ubuf_head > 128 - 3) {
1384                                 lwsl_parser("DROP PING payload too large\n");
1385                                 goto ping_drop;
1386                         }
1387
1388                         /* stash the pong payload */
1389                         memcpy(wsi->u.ws.ping_payload_buf + LWS_PRE,
1390                                &wsi->u.ws.rx_ubuf[LWS_PRE],
1391                                 wsi->u.ws.rx_ubuf_head);
1392
1393                         wsi->u.ws.ping_payload_len = wsi->u.ws.rx_ubuf_head;
1394                         wsi->u.ws.ping_pending_flag = 1;
1395
1396                         /* get it sent as soon as possible */
1397                         lws_callback_on_writable(wsi);
1398 ping_drop:
1399                         wsi->u.ws.rx_ubuf_head = 0;
1400                         return 0;
1401
1402                 case LWSWSOPC_PONG:
1403                         lwsl_info("received pong\n");
1404                         lwsl_hexdump(&wsi->u.ws.rx_ubuf[LWS_PRE],
1405                                      wsi->u.ws.rx_ubuf_head);
1406
1407                         if (wsi->pending_timeout == PENDING_TIMEOUT_WS_PONG_CHECK_GET_PONG) {
1408                                 lwsl_info("received expected PONG on wsi %p\n", wsi);
1409                                 lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
1410                         }
1411
1412                         /* issue it */
1413                         callback_action = LWS_CALLBACK_RECEIVE_PONG;
1414                         break;
1415
1416                 case LWSWSOPC_TEXT_FRAME:
1417                 case LWSWSOPC_BINARY_FRAME:
1418                 case LWSWSOPC_CONTINUATION:
1419                         break;
1420
1421                 default:
1422                         lwsl_parser("passing opc %x up to exts\n",
1423                                     wsi->u.ws.opcode);
1424                         /*
1425                          * It's something special we can't understand here.
1426                          * Pass the payload up to the extension's parsing
1427                          * state machine.
1428                          */
1429
1430                         eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1431                         eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1432
1433                         if (lws_ext_cb_active(wsi, LWS_EXT_CB_EXTENDED_PAYLOAD_RX,
1434                                               &eff_buf, 0) <= 0)
1435                                 /* not handle or fail */
1436                                 lwsl_ext("ext opc opcode 0x%x unknown\n",
1437                                          wsi->u.ws.opcode);
1438
1439                         wsi->u.ws.rx_ubuf_head = 0;
1440                         return 0;
1441                 }
1442
1443                 /*
1444                  * No it's real payload, pass it up to the user callback.
1445                  * It's nicely buffered with the pre-padding taken care of
1446                  * so it can be sent straight out again using lws_write
1447                  */
1448
1449                 eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1450                 eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1451
1452 drain_extension:
1453                 lwsl_ext("%s: passing %d to ext\n", __func__, eff_buf.token_len);
1454
1455                 if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
1456                     wsi->state == LWSS_AWAITING_CLOSE_ACK)
1457                         goto already_done;
1458
1459                 n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_RX, &eff_buf, 0);
1460                 /* eff_buf may be pointing somewhere completely different now,
1461                  * it's the output
1462                  */
1463                 if (n < 0) {
1464                         /*
1465                          * we may rely on this to get RX, just drop connection
1466                          */
1467                         wsi->socket_is_permanently_unusable = 1;
1468                         return -1;
1469                 }
1470
1471                 if (rx_draining_ext && eff_buf.token_len == 0)
1472                         goto already_done;
1473
1474                 if (n && eff_buf.token_len) {
1475                         /* extension had more... main loop will come back */
1476                         lws_add_wsi_to_draining_ext_list(wsi);
1477                 } else
1478                         lws_remove_wsi_from_draining_ext_list(wsi);
1479
1480                 if (eff_buf.token_len > 0 ||
1481                     callback_action == LWS_CALLBACK_RECEIVE_PONG) {
1482                         eff_buf.token[eff_buf.token_len] = '\0';
1483
1484                         if (wsi->protocol->callback) {
1485
1486                                 if (callback_action == LWS_CALLBACK_RECEIVE_PONG)
1487                                         lwsl_info("Doing pong callback\n");
1488
1489                                 ret = user_callback_handle_rxflow(
1490                                                 wsi->protocol->callback,
1491                                                 wsi,
1492                                                 (enum lws_callback_reasons)callback_action,
1493                                                 wsi->user_space,
1494                                                 eff_buf.token,
1495                                                 eff_buf.token_len);
1496                         }
1497                         else
1498                                 lwsl_err("No callback on payload spill!\n");
1499                 }
1500
1501 already_done:
1502                 wsi->u.ws.rx_ubuf_head = 0;
1503                 break;
1504         }
1505
1506         return ret;
1507
1508 illegal_ctl_length:
1509
1510         lwsl_warn("Control frame with xtended length is illegal\n");
1511         /* kill the connection */
1512         return -1;
1513 }
1514
1515 LWS_VISIBLE size_t
1516 lws_remaining_packet_payload(struct lws *wsi)
1517 {
1518         return wsi->u.ws.rx_packet_length;
1519 }
1520
1521 /* Once we reach LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED, we know how much
1522  * to expect in that state and can deal with it in bulk more efficiently.
1523  */
1524
1525 int
1526 lws_payload_until_length_exhausted(struct lws *wsi, unsigned char **buf,
1527                                    size_t *len)
1528 {
1529         unsigned char *buffer = *buf, mask[4];
1530         int buffer_size, n;
1531         unsigned int avail;
1532         char *rx_ubuf;
1533
1534         if (wsi->protocol->rx_buffer_size)
1535                 buffer_size = wsi->protocol->rx_buffer_size;
1536         else
1537                 buffer_size = wsi->context->pt_serv_buf_size;
1538         avail = buffer_size - wsi->u.ws.rx_ubuf_head;
1539
1540         /* do not consume more than we should */
1541         if (avail > wsi->u.ws.rx_packet_length)
1542                 avail = wsi->u.ws.rx_packet_length;
1543
1544         /* do not consume more than what is in the buffer */
1545         if (avail > *len)
1546                 avail = *len;
1547
1548         /* we want to leave 1 byte for the parser to handle properly */
1549         if (avail <= 1)
1550                 return 0;
1551
1552         avail--;
1553         rx_ubuf = wsi->u.ws.rx_ubuf + LWS_PRE + wsi->u.ws.rx_ubuf_head;
1554         if (wsi->u.ws.all_zero_nonce)
1555                 memcpy(rx_ubuf, buffer, avail);
1556         else {
1557
1558                 for (n = 0; n < 4; n++)
1559                         mask[n] = wsi->u.ws.mask[(wsi->u.ws.mask_idx + n) & 3];
1560
1561                 /* deal with 4-byte chunks using unwrapped loop */
1562                 n = avail >> 2;
1563                 while (n--) {
1564                         *(rx_ubuf++) = *(buffer++) ^ mask[0];
1565                         *(rx_ubuf++) = *(buffer++) ^ mask[1];
1566                         *(rx_ubuf++) = *(buffer++) ^ mask[2];
1567                         *(rx_ubuf++) = *(buffer++) ^ mask[3];
1568                 }
1569                 /* and the remaining bytes bytewise */
1570                 for (n = 0; n < (int)(avail & 3); n++)
1571                         *(rx_ubuf++) = *(buffer++) ^ mask[n];
1572
1573                 wsi->u.ws.mask_idx = (wsi->u.ws.mask_idx + avail) & 3;
1574         }
1575
1576         (*buf) += avail;
1577         wsi->u.ws.rx_ubuf_head += avail;
1578         wsi->u.ws.rx_packet_length -= avail;
1579         *len -= avail;
1580
1581         return avail;
1582 }