lib/parsers.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2013 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21
  22 #include "private-libwebsockets.h"
  23
  24 unsigned char lextable[] = {
  25         #include "lextable.h"
  26 };
  27
  28 #define FAIL_CHAR 0x08
  29
  30 int LWS_WARN_UNUSED_RESULT
  31 lextable_decode(int pos, char c)
  32 {
  33         if (c >= 'A' && c <= 'Z')
  34                 c += 'a' - 'A';
  35
  36         while (1) {
  37                 if (lextable[pos] & (1 << 7)) { /* 1-byte, fail on mismatch */
  38                         if ((lextable[pos] & 0x7f) != c)
  39                                 return -1;
  40                         /* fall thru */
  41                         pos++;
  42                         if (lextable[pos] == FAIL_CHAR)
  43                                 return -1;
  44                         return pos;
  45                 }
  46
  47                 if (lextable[pos] == FAIL_CHAR)
  48                         return -1;
  49
  50                 /* b7 = 0, end or 3-byte */
  51                 if (lextable[pos] < FAIL_CHAR) /* terminal marker */
  52                         return pos;
  53
  54                 if (lextable[pos] == c) /* goto */
  55                         return pos + (lextable[pos + 1]) +
  56                                                 (lextable[pos + 2] << 8);
  57                 /* fall thru goto */
  58                 pos += 3;
  59                 /* continue */
  60         }
  61 }
  62
  63 void
  64 lws_header_table_reset(struct lws *wsi)
  65 {
  66         struct allocated_headers *ah = wsi->u.hdr.ah;
  67
  68         /* if we have the idea we're resetting 'our' ah, must be bound to one */
  69         assert(ah);
  70         /* ah also concurs with ownership */
  71         assert(ah->wsi == wsi);
  72
  73         /* init the ah to reflect no headers or data have appeared yet */
  74         memset(ah->frag_index, 0, sizeof(ah->frag_index));
  75         ah->nfrag = 0;
  76         ah->pos = 0;
  77
  78         /* and reset the rx state */
  79         ah->rxpos = 0;
  80         ah->rxlen = 0;
  81
  82         /* since we will restart the ah, our new headers are not completed */
  83         wsi->hdr_parsing_completed = 0;
  84 }
  85
  86 int LWS_WARN_UNUSED_RESULT
  87 lws_header_table_attach(struct lws *wsi)
  88 {
  89         struct lws_context *context = wsi->context;
  90         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
  91         struct lws_pollargs pa;
  92         struct lws **pwsi;
  93         int n;
  94
  95         lwsl_info("%s: wsi %p: ah %p (tsi %d)\n", __func__, (void *)wsi,
  96                  (void *)wsi->u.hdr.ah, wsi->tsi);
  97
  98         /* if we are already bound to one, just clear it down */
  99         if (wsi->u.hdr.ah) {
 100                 lwsl_info("cleardown\n");
 101                 goto reset;
 102         }
 103
 104         lws_pt_lock(pt);
 105         pwsi = &pt->ah_wait_list;
 106         while (*pwsi) {
 107                 if (*pwsi == wsi) {
 108                         /* if already waiting on list, if no new ah just ret */
 109                         if (pt->ah_count_in_use ==
 110                             context->max_http_header_pool) {
 111                                 lwsl_err("ah wl denied\n");
 112                                 goto bail;
 113                         }
 114                         /* new ah.... remove ourselves from waiting list */
 115                         *pwsi = wsi->u.hdr.ah_wait_list; /* set our prev to our next */
 116                         wsi->u.hdr.ah_wait_list = NULL; /* no next any more */
 117                         pt->ah_wait_list_length--;
 118                         break;
 119                 }
 120                 pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 121         }
 122         /*
 123          * pool is all busy... add us to waiting list and return that we
 124          * weren't able to deliver it right now
 125          */
 126         if (pt->ah_count_in_use == context->max_http_header_pool) {
 127                 lwsl_info("%s: adding %p to ah waiting list\n", __func__, wsi);
 128                 wsi->u.hdr.ah_wait_list = pt->ah_wait_list;
 129                 pt->ah_wait_list = wsi;
 130                 pt->ah_wait_list_length++;
 131
 132                 /* we cannot accept input then */
 133
 134                 _lws_change_pollfd(wsi, LWS_POLLIN, 0, &pa);
 135                 goto bail;
 136         }
 137
 138         for (n = 0; n < context->max_http_header_pool; n++)
 139                 if (!pt->ah_pool[n].in_use)
 140                         break;
 141
 142         /* if the count of in use said something free... */
 143         assert(n != context->max_http_header_pool);
 144
 145         wsi->u.hdr.ah = &pt->ah_pool[n];
 146         wsi->u.hdr.ah->in_use = 1;
 147         pt->ah_pool[n].wsi = wsi; /* mark our owner */
 148         pt->ah_count_in_use++;
 149
 150         _lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
 151
 152         lwsl_info("%s: wsi %p: ah %p: count %d (on exit)\n", __func__,
 153                   (void *)wsi, (void *)wsi->u.hdr.ah, pt->ah_count_in_use);
 154
 155         lws_pt_unlock(pt);
 156
 157 reset:
 158         lws_header_table_reset(wsi);
 159         time(&wsi->u.hdr.ah->assigned);
 160
 161         return 0;
 162
 163 bail:
 164         lws_pt_unlock(pt);
 165
 166         return 1;
 167 }
 168
 169 int lws_header_table_detach(struct lws *wsi)
 170 {
 171         struct lws_context *context = wsi->context;
 172         struct allocated_headers *ah = wsi->u.hdr.ah;
 173         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 174         struct lws_pollargs pa;
 175         struct lws **pwsi;
 176         time_t now;
 177
 178         lwsl_info("%s: wsi %p: ah %p (tsi=%d, count = %d)\n", __func__,
 179                   (void *)wsi, (void *)wsi->u.hdr.ah, wsi->tsi,
 180                   pt->ah_count_in_use);
 181
 182         /* may not be detached while he still has unprocessed rx */
 183         if (ah && ah->rxpos != ah->rxlen) {
 184                 lwsl_err("%s: %p: rxpos:%d, rxlen:%d\n", __func__, wsi,
 185                                 ah->rxpos, ah->rxlen);
 186                 assert(ah->rxpos == ah->rxlen);
 187         }
 188
 189         lws_pt_lock(pt);
 190
 191         pwsi = &pt->ah_wait_list;
 192         if (!ah) { /* remove from wait list if none attached */
 193                 while (*pwsi) {
 194                         if (*pwsi == wsi) {
 195                                 lwsl_info("%s: wsi %p, remv wait\n",
 196                                           __func__, wsi);
 197                                 *pwsi = wsi->u.hdr.ah_wait_list;
 198                                 wsi->u.hdr.ah_wait_list = NULL;
 199                                 pt->ah_wait_list_length--;
 200                                 goto bail;
 201                         }
 202                         pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 203                 }
 204                 /* no ah, not on list... no more business here */
 205                 goto bail;
 206         }
 207         /* we did have an ah attached */
 208         time(&now);
 209         if (now - wsi->u.hdr.ah->assigned > 3) {
 210                 /*
 211                  * we're detaching the ah, but it was held an
 212                  * unreasonably long time
 213                  */
 214                 lwsl_notice("%s: wsi %p: ah held %ds, "
 215                             "ah.rxpos %d, ah.rxlen %d, mode/state %d %d,"
 216                             "wsi->more_rx_waiting %d\n", __func__, wsi,
 217                             (int)(now - wsi->u.hdr.ah->assigned),
 218                             ah->rxpos, ah->rxlen, wsi->mode, wsi->state,
 219                             wsi->more_rx_waiting);
 220         }
 221
 222         /* if we think we're detaching one, there should be one in use */
 223         assert(pt->ah_count_in_use > 0);
 224         /* and this specific one should have been in use */
 225         assert(wsi->u.hdr.ah->in_use);
 226         wsi->u.hdr.ah = NULL;
 227         ah->wsi = NULL; /* no owner */
 228
 229         /* oh there is nobody on the waiting list... leave it at that then */
 230         if (!*pwsi) {
 231                 ah->in_use = 0;
 232                 pt->ah_count_in_use--;
 233
 234                 goto bail;
 235         }
 236
 237         /* somebody else on same tsi is waiting, give it to oldest guy */
 238
 239         lwsl_info("pt wait list %p\n", *pwsi);
 240         while ((*pwsi)->u.hdr.ah_wait_list)
 241                 pwsi = &(*pwsi)->u.hdr.ah_wait_list;
 242
 243         wsi = *pwsi;
 244         lwsl_info("last wsi in wait list %p\n", wsi);
 245
 246         wsi->u.hdr.ah = ah;
 247         ah->wsi = wsi; /* new owner */
 248         lws_header_table_reset(wsi);
 249         time(&wsi->u.hdr.ah->assigned);
 250
 251         assert(wsi->position_in_fds_table != -1);
 252
 253         lwsl_info("%s: Enabling %p POLLIN\n", __func__, wsi);
 254
 255         /* he has been stuck waiting for an ah, but now his wait is over,
 256          * let him progress
 257          */
 258         _lws_change_pollfd(wsi, 0, LWS_POLLIN, &pa);
 259
 260         /* point prev guy to next guy in list instead */
 261         *pwsi = wsi->u.hdr.ah_wait_list;
 262         /* the guy who got one is out of the list */
 263         wsi->u.hdr.ah_wait_list = NULL;
 264         pt->ah_wait_list_length--;
 265
 266         assert(!!pt->ah_wait_list_length == !!(int)(long)pt->ah_wait_list);
 267 bail:
 268         lws_pt_unlock(pt);
 269
 270         return 0;
 271 }
 272
 273 /**
 274  * lws_hdr_fragment_length: report length of a single fragment of a header
 275  *              The returned length does not include the space for a
 276  *              terminating '\0'
 277  *
 278  * @wsi: websocket connection
 279  * @h: which header index we are interested in
 280  * @frag_idx: which fragment of @h we want to get the length of
 281  */
 282
 283 LWS_VISIBLE int
 284 lws_hdr_fragment_length(struct lws *wsi, enum lws_token_indexes h, int frag_idx)
 285 {
 286         int n;
 287
 288         n = wsi->u.hdr.ah->frag_index[h];
 289         if (!n)
 290                 return 0;
 291         do {
 292                 if (!frag_idx)
 293                         return wsi->u.hdr.ah->frags[n].len;
 294                 n = wsi->u.hdr.ah->frags[n].nfrag;
 295         } while (frag_idx-- && n);
 296
 297         return 0;
 298 }
 299
 300 /**
 301  * lws_hdr_total_length: report length of all fragments of a header totalled up
 302  *              The returned length does not include the space for a
 303  *              terminating '\0'
 304  *
 305  * @wsi: websocket connection
 306  * @h: which header index we are interested in
 307  */
 308
 309 LWS_VISIBLE int lws_hdr_total_length(struct lws *wsi, enum lws_token_indexes h)
 310 {
 311         int n;
 312         int len = 0;
 313
 314         n = wsi->u.hdr.ah->frag_index[h];
 315         if (!n)
 316                 return 0;
 317         do {
 318                 len += wsi->u.hdr.ah->frags[n].len;
 319                 n = wsi->u.hdr.ah->frags[n].nfrag;
 320         } while (n);
 321
 322         return len;
 323 }
 324
 325 /**
 326  * lws_hdr_copy_fragment: copy a single fragment of the given header to a buffer
 327  *              The buffer length @len must include space for an additional
 328  *              terminating '\0', or it will fail returning -1.
 329  *              If the requested fragment index is not present, it fails
 330  *              returning -1.
 331  *
 332  * @wsi: websocket connection
 333  * @dst: destination buffer
 334  * @len: length of destination buffer
 335  * @h: which header index we are interested in
 336  * @frag_index: which fragment of @h we want to copy
 337  */
 338
 339 LWS_VISIBLE int lws_hdr_copy_fragment(struct lws *wsi, char *dst, int len,
 340                                       enum lws_token_indexes h, int frag_idx)
 341 {
 342         int n = 0;
 343         int f = wsi->u.hdr.ah->frag_index[h];
 344
 345         if (!f)
 346                 return -1;
 347
 348         while (n < frag_idx) {
 349                 f = wsi->u.hdr.ah->frags[f].nfrag;
 350                 if (!f)
 351                         return -1;
 352                 n++;
 353         }
 354
 355         if (wsi->u.hdr.ah->frags[f].len >= len)
 356                 return -1;
 357
 358         memcpy(dst, wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[f].offset,
 359                wsi->u.hdr.ah->frags[f].len);
 360         dst[wsi->u.hdr.ah->frags[f].len] = '\0';
 361
 362         return wsi->u.hdr.ah->frags[f].len;
 363 }
 364
 365 /**
 366  * lws_hdr_copy: 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  *
 370  * @wsi: websocket connection
 371  * @dst: destination buffer
 372  * @len: length of destination buffer
 373  * @h: which header index we are interested in
 374  */
 375
 376 LWS_VISIBLE int lws_hdr_copy(struct lws *wsi, char *dst, int len,
 377                              enum lws_token_indexes h)
 378 {
 379         int toklen = lws_hdr_total_length(wsi, h);
 380         int n;
 381
 382         if (toklen >= len)
 383                 return -1;
 384
 385         n = wsi->u.hdr.ah->frag_index[h];
 386         if (!n)
 387                 return 0;
 388
 389         do {
 390                 strcpy(dst, &wsi->u.hdr.ah->data[wsi->u.hdr.ah->frags[n].offset]);
 391                 dst += wsi->u.hdr.ah->frags[n].len;
 392                 n = wsi->u.hdr.ah->frags[n].nfrag;
 393         } while (n);
 394
 395         return toklen;
 396 }
 397
 398 char *lws_hdr_simple_ptr(struct lws *wsi, enum lws_token_indexes h)
 399 {
 400         int n;
 401
 402         n = wsi->u.hdr.ah->frag_index[h];
 403         if (!n)
 404                 return NULL;
 405
 406         return wsi->u.hdr.ah->data + wsi->u.hdr.ah->frags[n].offset;
 407 }
 408
 409 int LWS_WARN_UNUSED_RESULT
 410 lws_pos_in_bounds(struct lws *wsi)
 411 {
 412         if (wsi->u.hdr.ah->pos < wsi->context->max_http_header_data)
 413                 return 0;
 414
 415         if (wsi->u.hdr.ah->pos == wsi->context->max_http_header_data) {
 416                 lwsl_err("Ran out of header data space\n");
 417                 return 1;
 418         }
 419
 420         /*
 421          * with these tests everywhere, it should never be able to exceed
 422          * the limit, only meet the limit
 423          */
 424
 425         lwsl_err("%s: pos %d, limit %d\n", __func__, wsi->u.hdr.ah->pos,
 426                  wsi->context->max_http_header_data);
 427         assert(0);
 428
 429         return 1;
 430 }
 431
 432 int LWS_WARN_UNUSED_RESULT
 433 lws_hdr_simple_create(struct lws *wsi, enum lws_token_indexes h, const char *s)
 434 {
 435         wsi->u.hdr.ah->nfrag++;
 436         if (wsi->u.hdr.ah->nfrag == ARRAY_SIZE(wsi->u.hdr.ah->frags)) {
 437                 lwsl_warn("More hdr frags than we can deal with, dropping\n");
 438                 return -1;
 439         }
 440
 441         wsi->u.hdr.ah->frag_index[h] = wsi->u.hdr.ah->nfrag;
 442
 443         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].offset = wsi->u.hdr.ah->pos;
 444         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len = 0;
 445         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].nfrag = 0;
 446
 447         do {
 448                 if (lws_pos_in_bounds(wsi))
 449                         return -1;
 450
 451                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = *s;
 452                 if (*s)
 453                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 454         } while (*s++);
 455
 456         return 0;
 457 }
 458
 459 static signed char char_to_hex(const char c)
 460 {
 461         if (c >= '0' && c <= '9')
 462                 return c - '0';
 463
 464         if (c >= 'a' && c <= 'f')
 465                 return c - 'a' + 10;
 466
 467         if (c >= 'A' && c <= 'F')
 468                 return c - 'A' + 10;
 469
 470         return -1;
 471 }
 472
 473 static int LWS_WARN_UNUSED_RESULT
 474 issue_char(struct lws *wsi, unsigned char c)
 475 {
 476         unsigned short frag_len;
 477
 478         if (lws_pos_in_bounds(wsi))
 479                 return -1;
 480
 481         frag_len = wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len;
 482         /*
 483          * If we haven't hit the token limit, just copy the character into
 484          * the header
 485          */
 486         if (frag_len < wsi->u.hdr.current_token_limit) {
 487                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = c;
 488                 if (c)
 489                         wsi->u.hdr.ah->frags[wsi->u.hdr.ah->nfrag].len++;
 490                 return 0;
 491         }
 492
 493         /* Insert a null character when we *hit* the limit: */
 494         if (frag_len == wsi->u.hdr.current_token_limit) {
 495                 if (lws_pos_in_bounds(wsi))
 496                         return -1;
 497                 wsi->u.hdr.ah->data[wsi->u.hdr.ah->pos++] = '\0';
 498                 lwsl_warn("header %i exceeds limit %d\n",
 499                           wsi->u.hdr.parser_state,
 500                           wsi->u.hdr.current_token_limit);
 501         }
 502
 503         return 1;
 504 }
 505
 506 int LWS_WARN_UNUSED_RESULT
 507 lws_parse(struct lws *wsi, unsigned char c)
 508 {
 509         static const unsigned char methods[] = {
 510                 WSI_TOKEN_GET_URI,
 511                 WSI_TOKEN_POST_URI,
 512                 WSI_TOKEN_OPTIONS_URI,
 513                 WSI_TOKEN_PUT_URI,
 514                 WSI_TOKEN_PATCH_URI,
 515                 WSI_TOKEN_DELETE_URI,
 516         };
 517         struct allocated_headers *ah = wsi->u.hdr.ah;
 518         struct lws_context *context = wsi->context;
 519         unsigned int n, m, enc = 0;
 520
 521         assert(wsi->u.hdr.ah);
 522
 523         switch (wsi->u.hdr.parser_state) {
 524         default:
 525
 526                 lwsl_parser("WSI_TOK_(%d) '%c'\n", wsi->u.hdr.parser_state, c);
 527
 528                 /* collect into malloc'd buffers */
 529                 /* optional initial space swallow */
 530                 if (!ah->frags[ah->frag_index[wsi->u.hdr.parser_state]].len &&
 531                     c == ' ')
 532                         break;
 533
 534                 for (m = 0; m < ARRAY_SIZE(methods); m++)
 535                         if (wsi->u.hdr.parser_state == methods[m])
 536                                 break;
 537                 if (m == ARRAY_SIZE(methods))
 538                         /* it was not any of the methods */
 539                         goto check_eol;
 540
 541                 /* special URI processing... end at space */
 542
 543                 if (c == ' ') {
 544                         /* enforce starting with / */
 545                         if (!ah->frags[ah->nfrag].len)
 546                                 if (issue_char(wsi, '/') < 0)
 547                                         return -1;
 548
 549                         /* begin parsing HTTP version: */
 550                         if (issue_char(wsi, '\0') < 0)
 551                                 return -1;
 552                         wsi->u.hdr.parser_state = WSI_TOKEN_HTTP;
 553                         goto start_fragment;
 554                 }
 555
 556                 /* special URI processing... convert %xx */
 557
 558                 switch (wsi->u.hdr.ues) {
 559                 case URIES_IDLE:
 560                         if (c == '%') {
 561                                 wsi->u.hdr.ues = URIES_SEEN_PERCENT;
 562                                 goto swallow;
 563                         }
 564                         break;
 565                 case URIES_SEEN_PERCENT:
 566                         if (char_to_hex(c) < 0) {
 567                                 /* regurgitate */
 568                                 if (issue_char(wsi, '%') < 0)
 569                                         return -1;
 570                                 wsi->u.hdr.ues = URIES_IDLE;
 571                                 /* continue on to assess c */
 572                                 break;
 573                         }
 574                         wsi->u.hdr.esc_stash = c;
 575                         wsi->u.hdr.ues = URIES_SEEN_PERCENT_H1;
 576                         goto swallow;
 577
 578                 case URIES_SEEN_PERCENT_H1:
 579                         if (char_to_hex(c) < 0) {
 580                                 /* regurgitate */
 581                                 if (issue_char(wsi, '%') < 0)
 582                                         return -1;
 583                                 wsi->u.hdr.ues = URIES_IDLE;
 584                                 /* regurgitate + assess */
 585                                 if (lws_parse(wsi, wsi->u.hdr.esc_stash) < 0)
 586                                         return -1;
 587                                 /* continue on to assess c */
 588                                 break;
 589                         }
 590                         c = (char_to_hex(wsi->u.hdr.esc_stash) << 4) |
 591                                         char_to_hex(c);
 592                         enc = 1;
 593                         wsi->u.hdr.ues = URIES_IDLE;
 594                         break;
 595                 }
 596
 597                 /*
 598                  * special URI processing...
 599                  *  convert /.. or /... or /../ etc to /
 600                  *  convert /./ to /
 601                  *  convert // or /// etc to /
 602                  *  leave /.dir or whatever alone
 603                  */
 604
 605                 switch (wsi->u.hdr.ups) {
 606                 case URIPS_IDLE:
 607                         if (!c)
 608                                 return -1;
 609                         /* genuine delimiter */
 610                         if ((c == '&' || c == ';') && !enc) {
 611                                 if (issue_char(wsi, c) < 0)
 612                                         return -1;
 613                                 /* swallow the terminator */
 614                                 ah->frags[ah->nfrag].len--;
 615                                 /* link to next fragment */
 616                                 ah->frags[ah->nfrag].nfrag = ah->nfrag + 1;
 617                                 ah->nfrag++;
 618                                 if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 619                                         goto excessive;
 620                                 /* start next fragment after the & */
 621                                 wsi->u.hdr.post_literal_equal = 0;
 622                                 ah->frags[ah->nfrag].offset = ah->pos;
 623                                 ah->frags[ah->nfrag].len = 0;
 624                                 ah->frags[ah->nfrag].nfrag = 0;
 625                                 goto swallow;
 626                         }
 627                         /* uriencoded = in the name part, disallow */
 628                         if (c == '=' && enc && !wsi->u.hdr.post_literal_equal)
 629                                 c = '_';
 630
 631                         /* after the real =, we don't care how many = */
 632                         if (c == '=' && !enc)
 633                                 wsi->u.hdr.post_literal_equal = 1;
 634
 635                         /* + to space */
 636                         if (c == '+' && !enc)
 637                                 c = ' ';
 638                         /* issue the first / always */
 639                         if (c == '/' && !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS])
 640                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 641                         break;
 642                 case URIPS_SEEN_SLASH:
 643                         /* swallow subsequent slashes */
 644                         if (c == '/')
 645                                 goto swallow;
 646                         /* track and swallow the first . after / */
 647                         if (c == '.') {
 648                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT;
 649                                 goto swallow;
 650                         }
 651                         wsi->u.hdr.ups = URIPS_IDLE;
 652                         break;
 653                 case URIPS_SEEN_SLASH_DOT:
 654                         /* swallow second . */
 655                         if (c == '.') {
 656                                 /*
 657                                  * back up one dir level if possible
 658                                  * safe against header fragmentation because
 659                                  * the method URI can only be in 1 fragment
 660                                  */
 661                                 if (ah->frags[ah->nfrag].len > 2) {
 662                                         ah->pos--;
 663                                         ah->frags[ah->nfrag].len--;
 664                                         do {
 665                                                 ah->pos--;
 666                                                 ah->frags[ah->nfrag].len--;
 667                                         } while (ah->frags[ah->nfrag].len > 1 &&
 668                                                  ah->data[ah->pos] != '/');
 669                                 }
 670                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH_DOT_DOT;
 671                                 goto swallow;
 672                         }
 673                         /* change /./ to / */
 674                         if (c == '/') {
 675                                 wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 676                                 goto swallow;
 677                         }
 678                         /* it was like /.dir ... regurgitate the . */
 679                         wsi->u.hdr.ups = URIPS_IDLE;
 680                         if (issue_char(wsi, '.') < 0)
 681                                 return -1;
 682                         break;
 683
 684                 case URIPS_SEEN_SLASH_DOT_DOT:
 685                         /* swallow prior .. chars and any subsequent . */
 686                         if (c == '.')
 687                                 goto swallow;
 688                         /* last issued was /, so another / == // */
 689                         if (c == '/')
 690                                 goto swallow;
 691                         /* last we issued was / so SEEN_SLASH */
 692                         wsi->u.hdr.ups = URIPS_SEEN_SLASH;
 693                         break;
 694                 }
 695
 696                 if (c == '?' && !enc &&
 697                     !ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS]) { /* start of URI arguments */
 698                         /* seal off uri header */
 699                         if (issue_char(wsi, '\0') < 0)
 700                                 return -1;
 701
 702                         /* move to using WSI_TOKEN_HTTP_URI_ARGS */
 703                         ah->nfrag++;
 704                         if (ah->nfrag >= ARRAY_SIZE(ah->frags))
 705                                 goto excessive;
 706                         ah->frags[ah->nfrag].offset = ah->pos;
 707                         ah->frags[ah->nfrag].len = 0;
 708                         ah->frags[ah->nfrag].nfrag = 0;
 709
 710                         wsi->u.hdr.post_literal_equal = 0;
 711                         ah->frag_index[WSI_TOKEN_HTTP_URI_ARGS] = ah->nfrag;
 712                         wsi->u.hdr.ups = URIPS_IDLE;
 713                         goto swallow;
 714                 }
 715
 716 check_eol:
 717
 718                 /* bail at EOL */
 719                 if (wsi->u.hdr.parser_state != WSI_TOKEN_CHALLENGE &&
 720                     c == '\x0d') {
 721                         c = '\0';
 722                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 723                         lwsl_parser("*\n");
 724                 }
 725
 726                 n = issue_char(wsi, c);
 727                 if ((int)n < 0)
 728                         return -1;
 729                 if (n > 0)
 730                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 731
 732 swallow:
 733                 /* per-protocol end of headers management */
 734
 735                 if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 736                         goto set_parsing_complete;
 737                 break;
 738
 739                 /* collecting and checking a name part */
 740         case WSI_TOKEN_NAME_PART:
 741                 lwsl_parser("WSI_TOKEN_NAME_PART '%c' (mode=%d)\n", c, wsi->mode);
 742
 743                 wsi->u.hdr.lextable_pos =
 744                                 lextable_decode(wsi->u.hdr.lextable_pos, c);
 745                 /*
 746                  * Server needs to look out for unknown methods...
 747                  */
 748                 if (wsi->u.hdr.lextable_pos < 0 &&
 749                     wsi->mode == LWSCM_HTTP_SERVING) {
 750                         /* this is not a header we know about */
 751                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 752                                 if (ah->frag_index[methods[m]]) {
 753                                         /*
 754                                          * already had the method, no idea what
 755                                          * this crap from the client is, ignore
 756                                          */
 757                                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 758                                         break;
 759                                 }
 760                         /*
 761                          * hm it's an unknown http method from a client in fact,
 762                          * treat as dangerous
 763                          */
 764                         if (m == ARRAY_SIZE(methods)) {
 765                                 lwsl_info("Unknown method - dropping\n");
 766                                 return -1;
 767                         }
 768                         break;
 769                 }
 770                 /*
 771                  * ...otherwise for a client, let him ignore unknown headers
 772                  * coming from the server
 773                  */
 774                 if (wsi->u.hdr.lextable_pos < 0) {
 775                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 776                         break;
 777                 }
 778
 779                 if (lextable[wsi->u.hdr.lextable_pos] < FAIL_CHAR) {
 780                         /* terminal state */
 781
 782                         n = ((unsigned int)lextable[wsi->u.hdr.lextable_pos] << 8) |
 783                                         lextable[wsi->u.hdr.lextable_pos + 1];
 784
 785                         lwsl_parser("known hdr %d\n", n);
 786                         for (m = 0; m < ARRAY_SIZE(methods); m++)
 787                                 if (n == methods[m] &&
 788                                     ah->frag_index[methods[m]]) {
 789                                         lwsl_warn("Duplicated method\n");
 790                                         return -1;
 791                                 }
 792
 793                         /*
 794                          * WSORIGIN is protocol equiv to ORIGIN,
 795                          * JWebSocket likes to send it, map to ORIGIN
 796                          */
 797                         if (n == WSI_TOKEN_SWORIGIN)
 798                                 n = WSI_TOKEN_ORIGIN;
 799
 800                         wsi->u.hdr.parser_state = (enum lws_token_indexes)
 801                                                         (WSI_TOKEN_GET_URI + n);
 802
 803                         if (context->token_limits)
 804                                 wsi->u.hdr.current_token_limit =
 805                                         context->token_limits->token_limit[
 806                                                        wsi->u.hdr.parser_state];
 807                         else
 808                                 wsi->u.hdr.current_token_limit =
 809                                         wsi->context->max_http_header_data;
 810
 811                         if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
 812                                 goto set_parsing_complete;
 813
 814                         goto start_fragment;
 815                 }
 816                 break;
 817
 818 start_fragment:
 819                 ah->nfrag++;
 820 excessive:
 821                 if (ah->nfrag == ARRAY_SIZE(ah->frags)) {
 822                         lwsl_warn("More hdr frags than we can deal with\n");
 823                         return -1;
 824                 }
 825
 826                 ah->frags[ah->nfrag].offset = ah->pos;
 827                 ah->frags[ah->nfrag].len = 0;
 828                 ah->frags[ah->nfrag].nfrag = 0;
 829
 830                 n = ah->frag_index[wsi->u.hdr.parser_state];
 831                 if (!n) { /* first fragment */
 832                         ah->frag_index[wsi->u.hdr.parser_state] = ah->nfrag;
 833                         break;
 834                 }
 835                 /* continuation */
 836                 while (ah->frags[n].nfrag)
 837                         n = ah->frags[n].nfrag;
 838                 ah->frags[n].nfrag = ah->nfrag;
 839
 840                 if (issue_char(wsi, ' ') < 0)
 841                         return -1;
 842                 break;
 843
 844                 /* skipping arg part of a name we didn't recognize */
 845         case WSI_TOKEN_SKIPPING:
 846                 lwsl_parser("WSI_TOKEN_SKIPPING '%c'\n", c);
 847
 848                 if (c == '\x0d')
 849                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING_SAW_CR;
 850                 break;
 851
 852         case WSI_TOKEN_SKIPPING_SAW_CR:
 853                 lwsl_parser("WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c);
 854                 if (c == '\x0a') {
 855                         wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
 856                         wsi->u.hdr.lextable_pos = 0;
 857                 } else
 858                         wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
 859                 break;
 860                 /* we're done, ignore anything else */
 861
 862         case WSI_PARSING_COMPLETE:
 863                 lwsl_parser("WSI_PARSING_COMPLETE '%c'\n", c);
 864                 break;
 865         }
 866
 867         return 0;
 868
 869 set_parsing_complete:
 870
 871         if (lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE)) {
 872                 if (lws_hdr_total_length(wsi, WSI_TOKEN_VERSION))
 873                         wsi->ietf_spec_revision =
 874                                atoi(lws_hdr_simple_ptr(wsi, WSI_TOKEN_VERSION));
 875
 876                 lwsl_parser("v%02d hdrs completed\n", wsi->ietf_spec_revision);
 877         }
 878         wsi->u.hdr.parser_state = WSI_PARSING_COMPLETE;
 879         wsi->hdr_parsing_completed = 1;
 880
 881         return 0;
 882 }
 883
 884
 885 /**
 886  * lws_frame_is_binary: true if the current frame was sent in binary mode
 887  *
 888  * @wsi: the connection we are inquiring about
 889  *
 890  * This is intended to be called from the LWS_CALLBACK_RECEIVE callback if
 891  * it's interested to see if the frame it's dealing with was sent in binary
 892  * mode.
 893  */
 894
 895 LWS_VISIBLE int lws_frame_is_binary(struct lws *wsi)
 896 {
 897         return wsi->u.ws.frame_is_binary;
 898 }
 899
 900 int
 901 lws_rx_sm(struct lws *wsi, unsigned char c)
 902 {
 903         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 904         int callback_action = LWS_CALLBACK_RECEIVE;
 905         int ret = 0, n, rx_draining_ext = 0;
 906         struct lws_tokens eff_buf;
 907
 908         if (wsi->socket_is_permanently_unusable)
 909                 return -1;
 910
 911         switch (wsi->lws_rx_parse_state) {
 912         case LWS_RXPS_NEW:
 913                 if (wsi->u.ws.rx_draining_ext) {
 914                         struct lws **w = &pt->rx_draining_ext_list;
 915
 916                         eff_buf.token = NULL;
 917                         eff_buf.token_len = 0;
 918                         wsi->u.ws.rx_draining_ext = 0;
 919                         /* remove us from context draining ext list */
 920                         while (*w) {
 921                                 if (*w == wsi) {
 922                                         *w = wsi->u.ws.rx_draining_ext_list;
 923                                         break;
 924                                 }
 925                                 w = &((*w)->u.ws.rx_draining_ext_list);
 926                         }
 927                         wsi->u.ws.rx_draining_ext_list = NULL;
 928                         rx_draining_ext = 1;
 929                         lwsl_err("%s: doing draining flow\n", __func__);
 930
 931                         goto drain_extension;
 932                 }
 933                 switch (wsi->ietf_spec_revision) {
 934                 case 13:
 935                         /*
 936                          * no prepended frame key any more
 937                          */
 938                         wsi->u.ws.all_zero_nonce = 1;
 939                         goto handle_first;
 940
 941                 default:
 942                         lwsl_warn("lws_rx_sm: unknown spec version %d\n",
 943                                                        wsi->ietf_spec_revision);
 944                         break;
 945                 }
 946                 break;
 947         case LWS_RXPS_04_mask_1:
 948                 wsi->u.ws.mask[1] = c;
 949                 if (c)
 950                         wsi->u.ws.all_zero_nonce = 0;
 951                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_2;
 952                 break;
 953         case LWS_RXPS_04_mask_2:
 954                 wsi->u.ws.mask[2] = c;
 955                 if (c)
 956                         wsi->u.ws.all_zero_nonce = 0;
 957                 wsi->lws_rx_parse_state = LWS_RXPS_04_mask_3;
 958                 break;
 959         case LWS_RXPS_04_mask_3:
 960                 wsi->u.ws.mask[3] = c;
 961                 if (c)
 962                         wsi->u.ws.all_zero_nonce = 0;
 963
 964                 /*
 965                  * start from the zero'th byte in the XOR key buffer since
 966                  * this is the start of a frame with a new key
 967                  */
 968
 969                 wsi->u.ws.mask_idx = 0;
 970
 971                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_1;
 972                 break;
 973
 974         /*
 975          *  04 logical framing from the spec (all this is masked when incoming
 976          *  and has to be unmasked)
 977          *
 978          * We ignore the possibility of extension data because we don't
 979          * negotiate any extensions at the moment.
 980          *
 981          *    0                   1                   2                   3
 982          *    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
 983          *   +-+-+-+-+-------+-+-------------+-------------------------------+
 984          *   |F|R|R|R| opcode|R| Payload len |    Extended payload length    |
 985          *   |I|S|S|S|  (4)  |S|     (7)     |             (16/63)           |
 986          *   |N|V|V|V|       |V|             |   (if payload len==126/127)   |
 987          *   | |1|2|3|       |4|             |                               |
 988          *   +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
 989          *   |     Extended payload length continued, if payload len == 127  |
 990          *   + - - - - - - - - - - - - - - - +-------------------------------+
 991          *   |                               |         Extension data        |
 992          *   +-------------------------------+ - - - - - - - - - - - - - - - +
 993          *   :                                                               :
 994          *   +---------------------------------------------------------------+
 995          *   :                       Application data                        :
 996          *   +---------------------------------------------------------------+
 997          *
 998          *  We pass payload through to userland as soon as we get it, ignoring
 999          *  FIN.  It's up to userland to buffer it up if it wants to see a
1000          *  whole unfragmented block of the original size (which may be up to
1001          *  2^63 long!)
1002          */
1003
1004         case LWS_RXPS_04_FRAME_HDR_1:
1005 handle_first:
1006
1007                 wsi->u.ws.opcode = c & 0xf;
1008                 wsi->u.ws.rsv = c & 0x70;
1009                 wsi->u.ws.final = !!((c >> 7) & 1);
1010
1011                 switch (wsi->u.ws.opcode) {
1012                 case LWSWSOPC_TEXT_FRAME:
1013                 case LWSWSOPC_BINARY_FRAME:
1014                         wsi->u.ws.rsv_first_msg = (c & 0x70);
1015                         wsi->u.ws.frame_is_binary =
1016                              wsi->u.ws.opcode == LWSWSOPC_BINARY_FRAME;
1017                         break;
1018                 case 3:
1019                 case 4:
1020                 case 5:
1021                 case 6:
1022                 case 7:
1023                 case 0xb:
1024                 case 0xc:
1025                 case 0xd:
1026                 case 0xe:
1027                 case 0xf:
1028                         lwsl_info("illegal opcode\n");
1029                         return -1;
1030                 }
1031                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN;
1032                 break;
1033
1034         case LWS_RXPS_04_FRAME_HDR_LEN:
1035
1036                 wsi->u.ws.this_frame_masked = !!(c & 0x80);
1037
1038                 switch (c & 0x7f) {
1039                 case 126:
1040                         /* control frames are not allowed to have big lengths */
1041                         if (wsi->u.ws.opcode & 8)
1042                                 goto illegal_ctl_length;
1043
1044                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_2;
1045                         break;
1046                 case 127:
1047                         /* control frames are not allowed to have big lengths */
1048                         if (wsi->u.ws.opcode & 8)
1049                                 goto illegal_ctl_length;
1050
1051                         wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_8;
1052                         break;
1053                 default:
1054                         wsi->u.ws.rx_packet_length = c & 0x7f;
1055                         if (wsi->u.ws.this_frame_masked)
1056                                 wsi->lws_rx_parse_state =
1057                                                 LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1058                         else
1059                                 if (wsi->u.ws.rx_packet_length)
1060                                         wsi->lws_rx_parse_state =
1061                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1062                                 else {
1063                                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1064                                         goto spill;
1065                                 }
1066                         break;
1067                 }
1068                 break;
1069
1070         case LWS_RXPS_04_FRAME_HDR_LEN16_2:
1071                 wsi->u.ws.rx_packet_length = c << 8;
1072                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN16_1;
1073                 break;
1074
1075         case LWS_RXPS_04_FRAME_HDR_LEN16_1:
1076                 wsi->u.ws.rx_packet_length |= c;
1077                 if (wsi->u.ws.this_frame_masked)
1078                         wsi->lws_rx_parse_state =
1079                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1080                 else
1081                         wsi->lws_rx_parse_state =
1082                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1083                 break;
1084
1085         case LWS_RXPS_04_FRAME_HDR_LEN64_8:
1086                 if (c & 0x80) {
1087                         lwsl_warn("b63 of length must be zero\n");
1088                         /* kill the connection */
1089                         return -1;
1090                 }
1091 #if defined __LP64__
1092                 wsi->u.ws.rx_packet_length = ((size_t)c) << 56;
1093 #else
1094                 wsi->u.ws.rx_packet_length = 0;
1095 #endif
1096                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_7;
1097                 break;
1098
1099         case LWS_RXPS_04_FRAME_HDR_LEN64_7:
1100 #if defined __LP64__
1101                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 48;
1102 #endif
1103                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_6;
1104                 break;
1105
1106         case LWS_RXPS_04_FRAME_HDR_LEN64_6:
1107 #if defined __LP64__
1108                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 40;
1109 #endif
1110                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_5;
1111                 break;
1112
1113         case LWS_RXPS_04_FRAME_HDR_LEN64_5:
1114 #if defined __LP64__
1115                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 32;
1116 #endif
1117                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_4;
1118                 break;
1119
1120         case LWS_RXPS_04_FRAME_HDR_LEN64_4:
1121                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 24;
1122                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_3;
1123                 break;
1124
1125         case LWS_RXPS_04_FRAME_HDR_LEN64_3:
1126                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 16;
1127                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_2;
1128                 break;
1129
1130         case LWS_RXPS_04_FRAME_HDR_LEN64_2:
1131                 wsi->u.ws.rx_packet_length |= ((size_t)c) << 8;
1132                 wsi->lws_rx_parse_state = LWS_RXPS_04_FRAME_HDR_LEN64_1;
1133                 break;
1134
1135         case LWS_RXPS_04_FRAME_HDR_LEN64_1:
1136                 wsi->u.ws.rx_packet_length |= ((size_t)c);
1137                 if (wsi->u.ws.this_frame_masked)
1138                         wsi->lws_rx_parse_state =
1139                                         LWS_RXPS_07_COLLECT_FRAME_KEY_1;
1140                 else
1141                         wsi->lws_rx_parse_state =
1142                                 LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1143                 break;
1144
1145         case LWS_RXPS_07_COLLECT_FRAME_KEY_1:
1146                 wsi->u.ws.mask[0] = c;
1147                 if (c)
1148                         wsi->u.ws.all_zero_nonce = 0;
1149                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_2;
1150                 break;
1151
1152         case LWS_RXPS_07_COLLECT_FRAME_KEY_2:
1153                 wsi->u.ws.mask[1] = c;
1154                 if (c)
1155                         wsi->u.ws.all_zero_nonce = 0;
1156                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_3;
1157                 break;
1158
1159         case LWS_RXPS_07_COLLECT_FRAME_KEY_3:
1160                 wsi->u.ws.mask[2] = c;
1161                 if (c)
1162                         wsi->u.ws.all_zero_nonce = 0;
1163                 wsi->lws_rx_parse_state = LWS_RXPS_07_COLLECT_FRAME_KEY_4;
1164                 break;
1165
1166         case LWS_RXPS_07_COLLECT_FRAME_KEY_4:
1167                 wsi->u.ws.mask[3] = c;
1168                 if (c)
1169                         wsi->u.ws.all_zero_nonce = 0;
1170                 wsi->lws_rx_parse_state =
1171                                         LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED;
1172                 wsi->u.ws.mask_idx = 0;
1173                 if (wsi->u.ws.rx_packet_length == 0) {
1174                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1175                         goto spill;
1176                 }
1177                 break;
1178
1179
1180         case LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED:
1181                 assert(wsi->u.ws.rx_ubuf);
1182
1183                 if (wsi->u.ws.rx_ubuf_head + LWS_PRE >=
1184                     wsi->u.ws.rx_ubuf_alloc) {
1185                         lwsl_err("Attempted overflow \n");
1186                         return -1;
1187                 }
1188                 if (wsi->u.ws.all_zero_nonce)
1189                         wsi->u.ws.rx_ubuf[LWS_PRE +
1190                                          (wsi->u.ws.rx_ubuf_head++)] = c;
1191                 else
1192                         wsi->u.ws.rx_ubuf[LWS_PRE +
1193                                (wsi->u.ws.rx_ubuf_head++)] =
1194                                    c ^ wsi->u.ws.mask[
1195                                             (wsi->u.ws.mask_idx++) & 3];
1196
1197                 if (--wsi->u.ws.rx_packet_length == 0) {
1198                         /* spill because we have the whole frame */
1199                         wsi->lws_rx_parse_state = LWS_RXPS_NEW;
1200                         goto spill;
1201                 }
1202
1203                 /*
1204                  * if there's no protocol max frame size given, we are
1205                  * supposed to default to LWS_MAX_SOCKET_IO_BUF
1206                  */
1207
1208                 if (!wsi->protocol->rx_buffer_size &&
1209                                         wsi->u.ws.rx_ubuf_head !=
1210                                                           LWS_MAX_SOCKET_IO_BUF)
1211                         break;
1212                 else
1213                         if (wsi->protocol->rx_buffer_size &&
1214                                         wsi->u.ws.rx_ubuf_head !=
1215                                                   wsi->protocol->rx_buffer_size)
1216                         break;
1217
1218                 /* spill because we filled our rx buffer */
1219 spill:
1220                 /*
1221                  * is this frame a control packet we should take care of at this
1222                  * layer?  If so service it and hide it from the user callback
1223                  */
1224
1225                 lwsl_parser("spill on %s\n", wsi->protocol->name);
1226
1227                 switch (wsi->u.ws.opcode) {
1228                 case LWSWSOPC_CLOSE:
1229
1230                         /* is this an acknowledgement of our close? */
1231                         if (wsi->state == LWSS_AWAITING_CLOSE_ACK) {
1232                                 /*
1233                                  * fine he has told us he is closing too, let's
1234                                  * finish our close
1235                                  */
1236                                 lwsl_parser("seen client close ack\n");
1237                                 return -1;
1238                         }
1239                         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
1240                                 /* if he sends us 2 CLOSE, kill him */
1241                                 return -1;
1242
1243                         if (user_callback_handle_rxflow(
1244                                         wsi->protocol->callback, wsi,
1245                                         LWS_CALLBACK_WS_PEER_INITIATED_CLOSE,
1246                                         wsi->user_space,
1247                                         &wsi->u.ws.rx_ubuf[LWS_PRE],
1248                                         wsi->u.ws.rx_ubuf_head))
1249                                 return -1;
1250
1251                         lwsl_parser("server sees client close packet\n");
1252                         wsi->state = LWSS_RETURNED_CLOSE_ALREADY;
1253                         /* deal with the close packet contents as a PONG */
1254                         wsi->u.ws.payload_is_close = 1;
1255                         goto process_as_ping;
1256
1257                 case LWSWSOPC_PING:
1258                         lwsl_info("received %d byte ping, sending pong\n",
1259                                                  wsi->u.ws.rx_ubuf_head);
1260
1261                         if (wsi->u.ws.ping_pending_flag) {
1262                                 /*
1263                                  * there is already a pending ping payload
1264                                  * we should just log and drop
1265                                  */
1266                                 lwsl_parser("DROP PING since one pending\n");
1267                                 goto ping_drop;
1268                         }
1269 process_as_ping:
1270                         /* control packets can only be < 128 bytes long */
1271                         if (wsi->u.ws.rx_ubuf_head > 128 - 3) {
1272                                 lwsl_parser("DROP PING payload too large\n");
1273                                 goto ping_drop;
1274                         }
1275
1276                         /* stash the pong payload */
1277                         memcpy(wsi->u.ws.ping_payload_buf + LWS_PRE,
1278                                &wsi->u.ws.rx_ubuf[LWS_PRE],
1279                                 wsi->u.ws.rx_ubuf_head);
1280
1281                         wsi->u.ws.ping_payload_len = wsi->u.ws.rx_ubuf_head;
1282                         wsi->u.ws.ping_pending_flag = 1;
1283
1284                         /* get it sent as soon as possible */
1285                         lws_callback_on_writable(wsi);
1286 ping_drop:
1287                         wsi->u.ws.rx_ubuf_head = 0;
1288                         return 0;
1289
1290                 case LWSWSOPC_PONG:
1291                         lwsl_info("received pong\n");
1292                         lwsl_hexdump(&wsi->u.ws.rx_ubuf[LWS_PRE],
1293                                      wsi->u.ws.rx_ubuf_head);
1294
1295                         /* issue it */
1296                         callback_action = LWS_CALLBACK_RECEIVE_PONG;
1297                         break;
1298
1299                 case LWSWSOPC_TEXT_FRAME:
1300                 case LWSWSOPC_BINARY_FRAME:
1301                 case LWSWSOPC_CONTINUATION:
1302                         break;
1303
1304                 default:
1305                         lwsl_parser("passing opc %x up to exts\n",
1306                                     wsi->u.ws.opcode);
1307                         /*
1308                          * It's something special we can't understand here.
1309                          * Pass the payload up to the extension's parsing
1310                          * state machine.
1311                          */
1312
1313                         eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1314                         eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1315
1316                         if (lws_ext_cb_active(wsi, LWS_EXT_CB_EXTENDED_PAYLOAD_RX,
1317                                         &eff_buf, 0) <= 0) /* not handle or fail */
1318                                 lwsl_ext("ext opc opcode 0x%x unknown\n",
1319                                                               wsi->u.ws.opcode);
1320
1321                         wsi->u.ws.rx_ubuf_head = 0;
1322                         return 0;
1323                 }
1324
1325                 /*
1326                  * No it's real payload, pass it up to the user callback.
1327                  * It's nicely buffered with the pre-padding taken care of
1328                  * so it can be sent straight out again using lws_write
1329                  */
1330
1331                 eff_buf.token = &wsi->u.ws.rx_ubuf[LWS_PRE];
1332                 eff_buf.token_len = wsi->u.ws.rx_ubuf_head;
1333
1334 drain_extension:
1335                 lwsl_ext("%s: passing %d to ext\n", __func__, eff_buf.token_len);
1336
1337                 if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
1338                     wsi->state == LWSS_AWAITING_CLOSE_ACK)
1339                         goto already_done;
1340
1341                 n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_RX, &eff_buf, 0);
1342                 if (n < 0) {
1343                         /*
1344                          * we may rely on this to get RX, just drop connection
1345                          */
1346                         wsi->socket_is_permanently_unusable = 1;
1347                         return -1;
1348                 }
1349
1350                 if (rx_draining_ext && eff_buf.token_len == 0)
1351                         goto already_done;
1352
1353                 if (n && eff_buf.token_len) {
1354                         /* extension had more... main loop will come back */
1355                         wsi->u.ws.rx_draining_ext = 1;
1356                         wsi->u.ws.rx_draining_ext_list = pt->rx_draining_ext_list;
1357                         pt->rx_draining_ext_list = wsi;
1358                 }
1359
1360                 if (eff_buf.token_len > 0 ||
1361                     callback_action == LWS_CALLBACK_RECEIVE_PONG) {
1362                         eff_buf.token[eff_buf.token_len] = '\0';
1363
1364                         if (wsi->protocol->callback) {
1365
1366                                 if (callback_action == LWS_CALLBACK_RECEIVE_PONG)
1367                                         lwsl_info("Doing pong callback\n");
1368
1369                                 ret = user_callback_handle_rxflow(
1370                                                 wsi->protocol->callback,
1371                                                 wsi,
1372                                                 (enum lws_callback_reasons)callback_action,
1373                                                 wsi->user_space,
1374                                                 eff_buf.token,
1375                                                 eff_buf.token_len);
1376                         }
1377                         else
1378                                 lwsl_err("No callback on payload spill!\n");
1379                 }
1380
1381 already_done:
1382                 wsi->u.ws.rx_ubuf_head = 0;
1383                 break;
1384         }
1385
1386         return ret;
1387
1388 illegal_ctl_length:
1389
1390         lwsl_warn("Control frame with xtended length is illegal\n");
1391         /* kill the connection */
1392         return -1;
1393 }
1394
1395
1396 /**
1397  * lws_remaining_packet_payload() - Bytes to come before "overall"
1398  *                                            rx packet is complete
1399  * @wsi:                Websocket instance (available from user callback)
1400  *
1401  *      This function is intended to be called from the callback if the
1402  *  user code is interested in "complete packets" from the client.
1403  *  libwebsockets just passes through payload as it comes and issues a buffer
1404  *  additionally when it hits a built-in limit.  The LWS_CALLBACK_RECEIVE
1405  *  callback handler can use this API to find out if the buffer it has just
1406  *  been given is the last piece of a "complete packet" from the client --
1407  *  when that is the case lws_remaining_packet_payload() will return
1408  *  0.
1409  *
1410  *  Many protocols won't care becuse their packets are always small.
1411  */
1412
1413 LWS_VISIBLE size_t
1414 lws_remaining_packet_payload(struct lws *wsi)
1415 {
1416         return wsi->u.ws.rx_packet_length;
1417 }
1418
1419 /* Once we reach LWS_RXPS_PAYLOAD_UNTIL_LENGTH_EXHAUSTED, we know how much
1420  * to expect in that state and can deal with it in bulk more efficiently.
1421  */
1422
1423 void
1424 lws_payload_until_length_exhausted(struct lws *wsi, unsigned char **buf,
1425                                    size_t *len)
1426 {
1427         unsigned char *buffer = *buf, mask[4];
1428         int buffer_size, avail, n;
1429         char *rx_ubuf;
1430
1431         if (wsi->protocol->rx_buffer_size)
1432                 buffer_size = wsi->protocol->rx_buffer_size;
1433         else
1434                 buffer_size = LWS_MAX_SOCKET_IO_BUF;
1435         avail = buffer_size - wsi->u.ws.rx_ubuf_head;
1436
1437         /* do not consume more than we should */
1438         if (avail > wsi->u.ws.rx_packet_length)
1439                 avail = wsi->u.ws.rx_packet_length;
1440
1441         /* do not consume more than what is in the buffer */
1442         if (avail > *len)
1443                 avail = *len;
1444
1445         /* we want to leave 1 byte for the parser to handle properly */
1446         if (avail <= 1)
1447                 return;
1448
1449         avail--;
1450         rx_ubuf = wsi->u.ws.rx_ubuf + LWS_PRE + wsi->u.ws.rx_ubuf_head;
1451         if (wsi->u.ws.all_zero_nonce)
1452                 memcpy(rx_ubuf, buffer, avail);
1453         else {
1454
1455                 for (n = 0; n < 4; n++)
1456                         mask[n] = wsi->u.ws.mask[(wsi->u.ws.mask_idx + n) & 3];
1457
1458                 /* deal with 4-byte chunks using unwrapped loop */
1459                 n = avail >> 2;
1460                 while (n--) {
1461                         *(rx_ubuf++) = *(buffer++) ^ mask[0];
1462                         *(rx_ubuf++) = *(buffer++) ^ mask[1];
1463                         *(rx_ubuf++) = *(buffer++) ^ mask[2];
1464                         *(rx_ubuf++) = *(buffer++) ^ mask[3];
1465                 }
1466                 /* and the remaining bytes bytewise */
1467                 for (n = 0; n < (avail & 3); n++)
1468                         *(rx_ubuf++) = *(buffer++) ^ mask[n];
1469
1470                 wsi->u.ws.mask_idx = (wsi->u.ws.mask_idx + avail) & 3;
1471         }
1472
1473         (*buf) += avail;
1474         wsi->u.ws.rx_ubuf_head += avail;
1475         wsi->u.ws.rx_packet_length -= avail;
1476         *len -= avail;
1477 }