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