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