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