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