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