lib/service.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2015 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 static int
  25 lws_calllback_as_writeable(struct lws *wsi)
  26 {
  27         int n;
  28
  29         switch (wsi->mode) {
  30         case LWSCM_RAW:
  31                 n = LWS_CALLBACK_RAW_WRITEABLE;
  32                 break;
  33         case LWSCM_RAW_FILEDESC:
  34                 n = LWS_CALLBACK_RAW_WRITEABLE_FILE;
  35                 break;
  36         case LWSCM_WS_CLIENT:
  37                 n = LWS_CALLBACK_CLIENT_WRITEABLE;
  38                 break;
  39         case LWSCM_WSCL_ISSUE_HTTP_BODY:
  40                 n = LWS_CALLBACK_CLIENT_HTTP_WRITEABLE;
  41                 break;
  42         case LWSCM_WS_SERVING:
  43                 n = LWS_CALLBACK_SERVER_WRITEABLE;
  44                 break;
  45         default:
  46                 n = LWS_CALLBACK_HTTP_WRITEABLE;
  47                 break;
  48         }
  49         lwsl_debug("%s: %p (user=%p)\n", __func__, wsi, wsi->user_space);
  50         return user_callback_handle_rxflow(wsi->protocol->callback,
  51                                            wsi, (enum lws_callback_reasons) n,
  52                                            wsi->user_space, NULL, 0);
  53 }
  54
  55 int
  56 lws_handle_POLLOUT_event(struct lws *wsi, struct lws_pollfd *pollfd)
  57 {
  58         int write_type = LWS_WRITE_PONG;
  59         struct lws_tokens eff_buf;
  60 #ifdef LWS_USE_HTTP2
  61         struct lws *wsi2;
  62 #endif
  63         int ret, m, n;
  64
  65         //lwsl_err("%s: %p\n", __func__, wsi);
  66
  67         /*
  68          * user callback is lowest priority to get these notifications
  69          * actually, since other pending things cannot be disordered
  70          */
  71
  72         /* Priority 1: pending truncated sends are incomplete ws fragments
  73          *             If anything else sent first the protocol would be
  74          *             corrupted.
  75          */
  76         if (wsi->trunc_len) {
  77                 if (lws_issue_raw(wsi, wsi->trunc_alloc + wsi->trunc_offset,
  78                                   wsi->trunc_len) < 0) {
  79                         lwsl_info("%s signalling to close\n", __func__);
  80                         return -1;
  81                 }
  82                 /* leave POLLOUT active either way */
  83                 return 0;
  84         } else
  85                 if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE)
  86                         return -1; /* retry closing now */
  87
  88         if (wsi->mode == LWSCM_WSCL_ISSUE_HTTP_BODY)
  89                 goto user_service;
  90
  91
  92 #ifdef LWS_USE_HTTP2
  93         /* Priority 2: protocol packets
  94          */
  95         if (wsi->pps) {
  96                 lwsl_info("servicing pps %d\n", wsi->pps);
  97                 switch (wsi->pps) {
  98                 case LWS_PPS_HTTP2_MY_SETTINGS:
  99                 case LWS_PPS_HTTP2_ACK_SETTINGS:
 100                         lws_http2_do_pps_send(lws_get_context(wsi), wsi);
 101                         break;
 102                 default:
 103                         break;
 104                 }
 105                 wsi->pps = LWS_PPS_NONE;
 106                 lws_rx_flow_control(wsi, 1);
 107
 108                 return 0; /* leave POLLOUT active */
 109         }
 110 #endif
 111
 112 #ifdef LWS_WITH_CGI
 113         if (wsi->cgi)
 114                 goto user_service_go_again;
 115 #endif
 116
 117         /* Priority 3: pending control packets (pong or close)
 118          */
 119         if ((wsi->state == LWSS_ESTABLISHED &&
 120              wsi->u.ws.ping_pending_flag) ||
 121             (wsi->state == LWSS_RETURNED_CLOSE_ALREADY &&
 122              wsi->u.ws.payload_is_close)) {
 123
 124                 if (wsi->u.ws.payload_is_close)
 125                         write_type = LWS_WRITE_CLOSE;
 126
 127                 n = lws_write(wsi, &wsi->u.ws.ping_payload_buf[LWS_PRE],
 128                               wsi->u.ws.ping_payload_len, write_type);
 129                 if (n < 0)
 130                         return -1;
 131
 132                 /* well he is sent, mark him done */
 133                 wsi->u.ws.ping_pending_flag = 0;
 134                 if (wsi->u.ws.payload_is_close)
 135                         /* oh... a close frame was it... then we are done */
 136                         return -1;
 137
 138                 /* otherwise for PING, leave POLLOUT active either way */
 139                 return 0;
 140         }
 141
 142         if (wsi->state == LWSS_ESTABLISHED &&
 143             !wsi->socket_is_permanently_unusable &&
 144             wsi->u.ws.send_check_ping) {
 145
 146                 lwsl_info("issuing ping on wsi %p\n", wsi);
 147                 wsi->u.ws.send_check_ping = 0;
 148                 n = lws_write(wsi, &wsi->u.ws.ping_payload_buf[LWS_PRE],
 149                               0, LWS_WRITE_PING);
 150                 if (n < 0)
 151                         return -1;
 152
 153                 /*
 154                  * we apparently were able to send the PING in a reasonable time
 155                  * now reset the clock on our peer to be able to send the
 156                  * PONG in a reasonable time.
 157                  */
 158
 159                 lws_set_timeout(wsi, PENDING_TIMEOUT_WS_PONG_CHECK_GET_PONG,
 160                                 wsi->context->timeout_secs);
 161
 162                 return 0;
 163         }
 164
 165         /* Priority 4: if we are closing, not allowed to send more data frags
 166          *             which means user callback or tx ext flush banned now
 167          */
 168         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
 169                 goto user_service;
 170
 171         /* Priority 5: Tx path extension with more to send
 172          *
 173          *             These are handled as new fragments each time around
 174          *             So while we must block new writeable callback to enforce
 175          *             payload ordering, but since they are always complete
 176          *             fragments control packets can interleave OK.
 177          */
 178         if (wsi->state == LWSS_ESTABLISHED && wsi->u.ws.tx_draining_ext) {
 179                 lwsl_ext("SERVICING TX EXT DRAINING\n");
 180                 if (lws_write(wsi, NULL, 0, LWS_WRITE_CONTINUATION) < 0)
 181                         return -1;
 182                 /* leave POLLOUT active */
 183                 return 0;
 184         }
 185
 186         /* Priority 6: user can get the callback
 187          */
 188         m = lws_ext_cb_active(wsi, LWS_EXT_CB_IS_WRITEABLE, NULL, 0);
 189         if (m)
 190                 return -1;
 191 #ifndef LWS_NO_EXTENSIONS
 192         if (!wsi->extension_data_pending)
 193                 goto user_service;
 194 #endif
 195         /*
 196          * check in on the active extensions, see if they
 197          * had pending stuff to spill... they need to get the
 198          * first look-in otherwise sequence will be disordered
 199          *
 200          * NULL, zero-length eff_buf means just spill pending
 201          */
 202
 203         ret = 1;
 204         if (wsi->mode == LWSCM_RAW || wsi->mode == LWSCM_RAW_FILEDESC)
 205                 ret = 0;
 206         while (ret == 1) {
 207
 208                 /* default to nobody has more to spill */
 209
 210                 ret = 0;
 211                 eff_buf.token = NULL;
 212                 eff_buf.token_len = 0;
 213
 214                 /* give every extension a chance to spill */
 215
 216                 m = lws_ext_cb_active(wsi,
 217                                         LWS_EXT_CB_PACKET_TX_PRESEND,
 218                                                &eff_buf, 0);
 219                 if (m < 0) {
 220                         lwsl_err("ext reports fatal error\n");
 221                         return -1;
 222                 }
 223                 if (m)
 224                         /*
 225                          * at least one extension told us he has more
 226                          * to spill, so we will go around again after
 227                          */
 228                         ret = 1;
 229
 230                 /* assuming they gave us something to send, send it */
 231
 232                 if (eff_buf.token_len) {
 233                         n = lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
 234                                           eff_buf.token_len);
 235                         if (n < 0) {
 236                                 lwsl_info("closing from POLLOUT spill\n");
 237                                 return -1;
 238                         }
 239                         /*
 240                          * Keep amount spilled small to minimize chance of this
 241                          */
 242                         if (n != eff_buf.token_len) {
 243                                 lwsl_err("Unable to spill ext %d vs %d\n",
 244                                                           eff_buf.token_len, n);
 245                                 return -1;
 246                         }
 247                 } else
 248                         continue;
 249
 250                 /* no extension has more to spill */
 251
 252                 if (!ret)
 253                         continue;
 254
 255                 /*
 256                  * There's more to spill from an extension, but we just sent
 257                  * something... did that leave the pipe choked?
 258                  */
 259
 260                 if (!lws_send_pipe_choked(wsi))
 261                         /* no we could add more */
 262                         continue;
 263
 264                 lwsl_info("choked in POLLOUT service\n");
 265
 266                 /*
 267                  * Yes, he's choked.  Leave the POLLOUT masked on so we will
 268                  * come back here when he is unchoked.  Don't call the user
 269                  * callback to enforce ordering of spilling, he'll get called
 270                  * when we come back here and there's nothing more to spill.
 271                  */
 272
 273                 return 0;
 274         }
 275 #ifndef LWS_NO_EXTENSIONS
 276         wsi->extension_data_pending = 0;
 277 #endif
 278 user_service:
 279         /* one shot */
 280
 281         if (pollfd)
 282                 if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
 283                         lwsl_info("failed at set pollfd\n");
 284                         return 1;
 285                 }
 286
 287         if (wsi->mode != LWSCM_WSCL_ISSUE_HTTP_BODY &&
 288             !wsi->hdr_parsing_completed)
 289                 return 0;
 290
 291 #ifdef LWS_WITH_CGI
 292 user_service_go_again:
 293 #endif
 294
 295 #ifdef LWS_USE_HTTP2
 296         /*
 297          * we are the 'network wsi' for potentially many muxed child wsi with
 298          * no network connection of their own, who have to use us for all their
 299          * network actions.  So we use a round-robin scheme to share out the
 300          * POLLOUT notifications to our children.
 301          *
 302          * But because any child could exhaust the socket's ability to take
 303          * writes, we can only let one child get notified each time.
 304          *
 305          * In addition children may be closed / deleted / added between POLLOUT
 306          * notifications, so we can't hold pointers
 307          */
 308
 309         if (wsi->mode != LWSCM_HTTP2_SERVING) {
 310                 lwsl_info("%s: non http2\n", __func__);
 311                 goto notify;
 312         }
 313
 314         wsi->u.http2.requested_POLLOUT = 0;
 315         if (!wsi->u.http2.initialized) {
 316                 lwsl_info("pollout on uninitialized http2 conn\n");
 317                 return 0;
 318         }
 319
 320         lwsl_info("%s: doing children\n", __func__);
 321
 322         wsi2 = wsi;
 323         do {
 324                 wsi2 = wsi2->u.http2.next_child_wsi;
 325                 lwsl_info("%s: child %p\n", __func__, wsi2);
 326                 if (!wsi2)
 327                         continue;
 328                 if (!wsi2->u.http2.requested_POLLOUT)
 329                         continue;
 330                 wsi2->u.http2.requested_POLLOUT = 0;
 331                 if (lws_calllback_as_writeable(wsi2)) {
 332                         lwsl_debug("Closing POLLOUT child\n");
 333                         lws_close_free_wsi(wsi2, LWS_CLOSE_STATUS_NOSTATUS);
 334                 }
 335                 wsi2 = wsi;
 336         } while (wsi2 != NULL && !lws_send_pipe_choked(wsi));
 337
 338         lwsl_info("%s: completed\n", __func__);
 339
 340         return 0;
 341 notify:
 342 #endif
 343         return lws_calllback_as_writeable(wsi);
 344 }
 345
 346 int
 347 lws_service_timeout_check(struct lws *wsi, unsigned int sec)
 348 {
 349 //#if LWS_POSIX
 350         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 351         int n = 0;
 352 //#endif
 353
 354         (void)n;
 355
 356         /*
 357          * if extensions want in on it (eg, we are a mux parent)
 358          * give them a chance to service child timeouts
 359          */
 360         if (lws_ext_cb_active(wsi, LWS_EXT_CB_1HZ, NULL, sec) < 0)
 361                 return 0;
 362
 363         if (!wsi->pending_timeout)
 364                 return 0;
 365
 366         /*
 367          * if we went beyond the allowed time, kill the
 368          * connection
 369          */
 370         if ((time_t)sec > wsi->pending_timeout_limit) {
 371 //#if LWS_POSIX
 372                 if (wsi->desc.sockfd != LWS_SOCK_INVALID && wsi->position_in_fds_table >= 0)
 373                         n = pt->fds[wsi->position_in_fds_table].events;
 374
 375                 /* no need to log normal idle keepalive timeout */
 376                 if (wsi->pending_timeout != PENDING_TIMEOUT_HTTP_KEEPALIVE_IDLE)
 377                         lwsl_notice("wsi %p: TIMEDOUT WAITING on %d (did hdr %d, ah %p, wl %d, pfd events %d) %llu vs %llu\n",
 378                             (void *)wsi, wsi->pending_timeout,
 379                             wsi->hdr_parsing_completed, wsi->u.hdr.ah,
 380                             pt->ah_wait_list_length, n, (unsigned long long)sec, (unsigned long long)wsi->pending_timeout_limit);
 381 //#endif
 382                 /*
 383                  * Since he failed a timeout, he already had a chance to do
 384                  * something and was unable to... that includes situations like
 385                  * half closed connections.  So process this "failed timeout"
 386                  * close as a violent death and don't try to do protocol
 387                  * cleanup like flush partials.
 388                  */
 389                 wsi->socket_is_permanently_unusable = 1;
 390                 if (wsi->mode == LWSCM_WSCL_WAITING_SSL)
 391                         wsi->vhost->protocols[0].callback(wsi,
 392                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 393                                 wsi->user_space, (void *)"Timed out waiting SSL", 21);
 394
 395                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 396
 397                 return 1;
 398         }
 399
 400         return 0;
 401 }
 402
 403 int lws_rxflow_cache(struct lws *wsi, unsigned char *buf, int n, int len)
 404 {
 405         /* his RX is flowcontrolled, don't send remaining now */
 406         if (wsi->rxflow_buffer) {
 407                 /* rxflow while we were spilling prev rxflow */
 408                 lwsl_info("stalling in existing rxflow buf\n");
 409                 return 1;
 410         }
 411
 412         /* a new rxflow, buffer it and warn caller */
 413         lwsl_info("new rxflow input buffer len %d\n", len - n);
 414         wsi->rxflow_buffer = lws_malloc(len - n);
 415         if (!wsi->rxflow_buffer)
 416                 return -1;
 417         wsi->rxflow_len = len - n;
 418         wsi->rxflow_pos = 0;
 419         memcpy(wsi->rxflow_buffer, buf + n, len - n);
 420
 421         return 0;
 422 }
 423
 424 /* this is used by the platform service code to stop us waiting for network
 425  * activity in poll() when we have something that already needs service
 426  */
 427
 428 LWS_VISIBLE LWS_EXTERN int
 429 lws_service_adjust_timeout(struct lws_context *context, int timeout_ms, int tsi)
 430 {
 431         struct lws_context_per_thread *pt = &context->pt[tsi];
 432         int n;
 433
 434         /* Figure out if we really want to wait in poll()
 435          * We only need to wait if really nothing already to do and we have
 436          * to wait for something from network
 437          */
 438
 439         /* 1) if we know we are draining rx ext, do not wait in poll */
 440         if (pt->rx_draining_ext_list)
 441                 return 0;
 442
 443 #ifdef LWS_OPENSSL_SUPPORT
 444         /* 2) if we know we have non-network pending data, do not wait in poll */
 445         if (lws_ssl_anybody_has_buffered_read_tsi(context, tsi)) {
 446                 lwsl_info("ssl buffered read\n");
 447                 return 0;
 448         }
 449 #endif
 450
 451         /* 3) if any ah has pending rx, do not wait in poll */
 452         for (n = 0; n < context->max_http_header_pool; n++)
 453                 if (pt->ah_pool[n].rxpos != pt->ah_pool[n].rxlen) {
 454                         /* any ah with pending rx must be attached to someone */
 455                         if (!pt->ah_pool[n].wsi) {
 456                                 lwsl_err("%s: assert: no wsi attached to ah\n", __func__);
 457                                 assert(0);
 458                         }
 459                         return 0;
 460                 }
 461
 462         return timeout_ms;
 463 }
 464
 465 /*
 466  * guys that need POLLIN service again without waiting for network action
 467  * can force POLLIN here if not flowcontrolled, so they will get service.
 468  *
 469  * Return nonzero if anybody got their POLLIN faked
 470  */
 471 int
 472 lws_service_flag_pending(struct lws_context *context, int tsi)
 473 {
 474         struct lws_context_per_thread *pt = &context->pt[tsi];
 475 #ifdef LWS_OPENSSL_SUPPORT
 476         struct lws *wsi_next;
 477 #endif
 478         struct lws *wsi;
 479         int forced = 0;
 480         int n;
 481
 482         /* POLLIN faking */
 483
 484         /*
 485          * 1) For all guys with already-available ext data to drain, if they are
 486          * not flowcontrolled, fake their POLLIN status
 487          */
 488         wsi = pt->rx_draining_ext_list;
 489         while (wsi) {
 490                 pt->fds[wsi->position_in_fds_table].revents |=
 491                         pt->fds[wsi->position_in_fds_table].events & LWS_POLLIN;
 492                 if (pt->fds[wsi->position_in_fds_table].revents &
 493                     LWS_POLLIN)
 494                         forced = 1;
 495                 wsi = wsi->u.ws.rx_draining_ext_list;
 496         }
 497
 498 #ifdef LWS_OPENSSL_SUPPORT
 499         /*
 500          * 2) For all guys with buffered SSL read data already saved up, if they
 501          * are not flowcontrolled, fake their POLLIN status so they'll get
 502          * service to use up the buffered incoming data, even though their
 503          * network socket may have nothing
 504          */
 505         wsi = pt->pending_read_list;
 506         while (wsi) {
 507                 wsi_next = wsi->pending_read_list_next;
 508                 pt->fds[wsi->position_in_fds_table].revents |=
 509                         pt->fds[wsi->position_in_fds_table].events & LWS_POLLIN;
 510                 if (pt->fds[wsi->position_in_fds_table].revents & LWS_POLLIN) {
 511                         forced = 1;
 512                         /*
 513                          * he's going to get serviced now, take him off the
 514                          * list of guys with buffered SSL.  If he still has some
 515                          * at the end of the service, he'll get put back on the
 516                          * list then.
 517                          */
 518                         lws_ssl_remove_wsi_from_buffered_list(wsi);
 519                 }
 520
 521                 wsi = wsi_next;
 522         }
 523 #endif
 524         /*
 525          * 3) For any wsi who have an ah with pending RX who did not
 526          * complete their current headers, and are not flowcontrolled,
 527          * fake their POLLIN status so they will be able to drain the
 528          * rx buffered in the ah
 529          */
 530         for (n = 0; n < context->max_http_header_pool; n++)
 531                 if (pt->ah_pool[n].rxpos != pt->ah_pool[n].rxlen &&
 532                     !pt->ah_pool[n].wsi->hdr_parsing_completed) {
 533                         pt->fds[pt->ah_pool[n].wsi->position_in_fds_table].revents |=
 534                                 pt->fds[pt->ah_pool[n].wsi->position_in_fds_table].events &
 535                                         LWS_POLLIN;
 536                         if (pt->fds[pt->ah_pool[n].wsi->position_in_fds_table].revents &
 537                             LWS_POLLIN)
 538                                 forced = 1;
 539                 }
 540
 541         return forced;
 542 }
 543
 544 #ifndef LWS_NO_CLIENT
 545
 546 LWS_VISIBLE int
 547 lws_http_client_read(struct lws *wsi, char **buf, int *len)
 548 {
 549         int rlen, n;
 550
 551         rlen = lws_ssl_capable_read(wsi, (unsigned char *)*buf, *len);
 552         *len = 0;
 553
 554         /* allow the source to signal he has data again next time */
 555         lws_change_pollfd(wsi, 0, LWS_POLLIN);
 556
 557         if (rlen == LWS_SSL_CAPABLE_ERROR) {
 558                 lwsl_notice("%s: SSL capable error\n", __func__);
 559                 return -1;
 560         }
 561
 562         if (rlen <= 0)
 563                 return 0;
 564
 565         *len = rlen;
 566         wsi->client_rx_avail = 0;
 567
 568         /*
 569          * server may insist on transfer-encoding: chunked,
 570          * so http client must deal with it
 571          */
 572 spin_chunks:
 573         while (wsi->chunked && (wsi->chunk_parser != ELCP_CONTENT) && *len) {
 574                 switch (wsi->chunk_parser) {
 575                 case ELCP_HEX:
 576                         if ((*buf)[0] == '\x0d') {
 577                                 wsi->chunk_parser = ELCP_CR;
 578                                 break;
 579                         }
 580                         n = char_to_hex((*buf)[0]);
 581                         if (n < 0) {
 582                                 lwsl_debug("chunking failure\n");
 583                                 return -1;
 584                         }
 585                         wsi->chunk_remaining <<= 4;
 586                         wsi->chunk_remaining |= n;
 587                         break;
 588                 case ELCP_CR:
 589                         if ((*buf)[0] != '\x0a') {
 590                                 lwsl_debug("chunking failure\n");
 591                                 return -1;
 592                         }
 593                         wsi->chunk_parser = ELCP_CONTENT;
 594                         lwsl_info("chunk %d\n", wsi->chunk_remaining);
 595                         if (wsi->chunk_remaining)
 596                                 break;
 597                         lwsl_info("final chunk\n");
 598                         goto completed;
 599
 600                 case ELCP_CONTENT:
 601                         break;
 602
 603                 case ELCP_POST_CR:
 604                         if ((*buf)[0] != '\x0d') {
 605                                 lwsl_debug("chunking failure\n");
 606
 607                                 return -1;
 608                         }
 609
 610                         wsi->chunk_parser = ELCP_POST_LF;
 611                         break;
 612
 613                 case ELCP_POST_LF:
 614                         if ((*buf)[0] != '\x0a')
 615                                 return -1;
 616
 617                         wsi->chunk_parser = ELCP_HEX;
 618                         wsi->chunk_remaining = 0;
 619                         break;
 620                 }
 621                 (*buf)++;
 622                 (*len)--;
 623         }
 624
 625         if (wsi->chunked && !wsi->chunk_remaining)
 626                 return 0;
 627
 628         if (wsi->u.http.content_remain &&
 629             (int)wsi->u.http.content_remain < *len)
 630                 n = wsi->u.http.content_remain;
 631         else
 632                 n = *len;
 633
 634         if (wsi->chunked && wsi->chunk_remaining &&
 635             wsi->chunk_remaining < n)
 636                 n = wsi->chunk_remaining;
 637
 638 #ifdef LWS_WITH_HTTP_PROXY
 639         /* hubbub */
 640         if (wsi->perform_rewrite)
 641                 lws_rewrite_parse(wsi->rw, (unsigned char *)*buf, n);
 642         else
 643 #endif
 644                 if (user_callback_handle_rxflow(wsi->protocol->callback,
 645                                 wsi, LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ,
 646                                 wsi->user_space, *buf, n)) {
 647                         lwsl_debug("%s: LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ returned -1\n", __func__);
 648
 649                         return -1;
 650                 }
 651
 652         if (wsi->chunked && wsi->chunk_remaining) {
 653                 (*buf) += n;
 654                 wsi->chunk_remaining -= n;
 655                 *len -= n;
 656         }
 657
 658         if (wsi->chunked && !wsi->chunk_remaining)
 659                 wsi->chunk_parser = ELCP_POST_CR;
 660
 661         if (wsi->chunked && *len)
 662                 goto spin_chunks;
 663
 664         if (wsi->chunked)
 665                 return 0;
 666
 667         /* if we know the content length, decrement the content remaining */
 668         if (wsi->u.http.content_length > 0)
 669                 wsi->u.http.content_remain -= n;
 670
 671         if (wsi->u.http.content_remain || !wsi->u.http.content_length)
 672                 return 0;
 673
 674 completed:
 675         if (user_callback_handle_rxflow(wsi->protocol->callback,
 676                         wsi, LWS_CALLBACK_COMPLETED_CLIENT_HTTP,
 677                         wsi->user_space, NULL, 0)) {
 678                 lwsl_debug("Completed call returned -1\n");
 679                 return -1;
 680         }
 681
 682         if (lws_http_transaction_completed_client(wsi)) {
 683                 lwsl_notice("%s: transaction completed says -1\n", __func__);
 684                 return -1;
 685         }
 686
 687         return 0;
 688 }
 689 #endif
 690
 691 LWS_VISIBLE int
 692 lws_service_fd_tsi(struct lws_context *context, struct lws_pollfd *pollfd, int tsi)
 693 {
 694         struct lws_context_per_thread *pt = &context->pt[tsi];
 695         lws_sockfd_type our_fd = 0, tmp_fd;
 696         struct lws_tokens eff_buf;
 697         unsigned int pending = 0;
 698         struct lws *wsi, *wsi1;
 699         char draining_flow = 0;
 700         int timed_out = 0;
 701         time_t now;
 702         int n = 0, m;
 703         int more;
 704
 705         if (!context->protocol_init_done)
 706                 lws_protocol_init(context);
 707
 708         time(&now);
 709
 710         /*
 711          * handle case that system time was uninitialized when lws started
 712          * at boot, and got initialized a little later
 713          */
 714         if (context->time_up < 1464083026 && now > 1464083026)
 715                 context->time_up = now;
 716
 717         /* TODO: if using libev, we should probably use timeout watchers... */
 718         if (context->last_timeout_check_s != now) {
 719                 context->last_timeout_check_s = now;
 720
 721                 lws_plat_service_periodic(context);
 722
 723                 /* retire unused deprecated context */
 724 #if !defined(LWS_PLAT_OPTEE) && !defined(LWS_WITH_ESP32)
 725 #if LWS_POSIX && !defined(_WIN32)
 726                 if (context->deprecated && !context->count_wsi_allocated) {
 727                         lwsl_notice("%s: ending deprecated context\n", __func__);
 728                         kill(getpid(), SIGINT);
 729                         return 0;
 730                 }
 731 #endif
 732 #endif
 733                 /* global timeout check once per second */
 734
 735                 if (pollfd)
 736                         our_fd = pollfd->fd;
 737
 738                 wsi = context->pt[tsi].timeout_list;
 739                 while (wsi) {
 740                         /* we have to take copies, because he may be deleted */
 741                         wsi1 = wsi->timeout_list;
 742                         tmp_fd = wsi->desc.sockfd;
 743                         if (lws_service_timeout_check(wsi, (unsigned int)now)) {
 744                                 /* he did time out... */
 745                                 if (tmp_fd == our_fd)
 746                                         /* it was the guy we came to service! */
 747                                         timed_out = 1;
 748                                         /* he's gone, no need to mark as handled */
 749                         }
 750                         wsi = wsi1;
 751                 }
 752 #ifdef LWS_WITH_CGI
 753                 lws_cgi_kill_terminated(pt);
 754 #endif
 755 #if 0
 756                 {
 757                         char s[300], *p = s;
 758
 759                         for (n = 0; n < context->count_threads; n++)
 760                                 p += sprintf(p, " %7lu (%5d), ",
 761                                              context->pt[n].count_conns,
 762                                              context->pt[n].fds_count);
 763
 764                         lwsl_notice("load: %s\n", s);
 765                 }
 766 #endif
 767         }
 768
 769         /*
 770          * at intervals, check for ws connections needing ping-pong checks
 771          */
 772
 773         if (context->ws_ping_pong_interval &&
 774             context->last_ws_ping_pong_check_s < now + 10) {
 775                 struct lws_vhost *vh = context->vhost_list;
 776                 context->last_ws_ping_pong_check_s = now;
 777
 778                 while (vh) {
 779                         for (n = 0; n < vh->count_protocols; n++) {
 780                                 wsi = vh->same_vh_protocol_list[n];
 781
 782                                 while (wsi) {
 783                                         if (wsi->state == LWSS_ESTABLISHED &&
 784                                             !wsi->socket_is_permanently_unusable &&
 785                                             !wsi->u.ws.send_check_ping &&
 786                                             wsi->u.ws.time_next_ping_check &&
 787                                             wsi->u.ws.time_next_ping_check < now) {
 788
 789                                                 lwsl_info("requesting ping-pong on wsi %p\n", wsi);
 790                                                 wsi->u.ws.send_check_ping = 1;
 791                                                 lws_set_timeout(wsi, PENDING_TIMEOUT_WS_PONG_CHECK_SEND_PING,
 792                                                                 context->timeout_secs);
 793                                                 lws_callback_on_writable(wsi);
 794                                                 wsi->u.ws.time_next_ping_check = now +
 795                                                                 wsi->context->ws_ping_pong_interval;
 796                                         }
 797                                         wsi = wsi->same_vh_protocol_next;
 798                                 }
 799                         }
 800                         vh = vh->vhost_next;
 801                 }
 802         }
 803
 804         /* the socket we came to service timed out, nothing to do */
 805         if (timed_out)
 806                 return 0;
 807
 808         /* just here for timeout management? */
 809         if (!pollfd)
 810                 return 0;
 811
 812         /* no, here to service a socket descriptor */
 813         wsi = wsi_from_fd(context, pollfd->fd);
 814         if (!wsi)
 815                 /* not lws connection ... leave revents alone and return */
 816                 return 0;
 817
 818         /*
 819          * so that caller can tell we handled, past here we need to
 820          * zero down pollfd->revents after handling
 821          */
 822
 823 #if LWS_POSIX
 824         /* handle session socket closed */
 825
 826         if ((!(pollfd->revents & pollfd->events & LWS_POLLIN)) &&
 827             (pollfd->revents & LWS_POLLHUP)) {
 828                 wsi->socket_is_permanently_unusable = 1;
 829                 lwsl_debug("Session Socket %p (fd=%d) dead\n",
 830                                                        (void *)wsi, pollfd->fd);
 831
 832                 goto close_and_handled;
 833         }
 834
 835 #ifdef _WIN32
 836         if (pollfd->revents & LWS_POLLOUT)
 837                 wsi->sock_send_blocking = FALSE;
 838 #endif
 839
 840 #endif
 841
 842         lwsl_debug("fd=%d, revents=%d\n", pollfd->fd, pollfd->revents);
 843         if (pollfd->revents & LWS_POLLHUP)
 844                 goto close_and_handled;
 845
 846         /* okay, what we came here to do... */
 847
 848         switch (wsi->mode) {
 849         case LWSCM_HTTP_SERVING:
 850         case LWSCM_HTTP_CLIENT:
 851         case LWSCM_HTTP_SERVING_ACCEPTED:
 852         case LWSCM_SERVER_LISTENER:
 853         case LWSCM_SSL_ACK_PENDING:
 854         case LWSCM_SSL_ACK_PENDING_RAW:
 855                 if (wsi->state == LWSS_CLIENT_HTTP_ESTABLISHED)
 856                         goto handled;
 857
 858 #ifdef LWS_WITH_CGI
 859                 if (wsi->cgi && (pollfd->revents & LWS_POLLOUT)) {
 860                         n = lws_handle_POLLOUT_event(wsi, pollfd);
 861                         if (n)
 862                                 goto close_and_handled;
 863                         goto handled;
 864                 }
 865 #endif
 866                 n = lws_server_socket_service(context, wsi, pollfd);
 867                 if (n) /* closed by above */
 868                         return 1;
 869                 goto handled;
 870
 871         case LWSCM_RAW_FILEDESC:
 872         case LWSCM_RAW:
 873                 if (pollfd->revents & LWS_POLLOUT) {
 874                         n = lws_calllback_as_writeable(wsi);
 875                         if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
 876                                 lwsl_info("failed at set pollfd\n");
 877                                 return 1;
 878                         }
 879                         if (n)
 880                                 goto close_and_handled;
 881                 }
 882                 n = LWS_CALLBACK_RAW_RX;
 883                 if (wsi->mode == LWSCM_RAW_FILEDESC)
 884                         n = LWS_CALLBACK_RAW_RX_FILE;
 885
 886                 if (pollfd->revents & LWS_POLLIN) {
 887                         if (user_callback_handle_rxflow(
 888                                         wsi->protocol->callback,
 889                                         wsi, n,
 890                                         wsi->user_space, NULL, 0)) {
 891                                 lwsl_debug("raw rx callback closed it\n");
 892                                 goto close_and_handled;
 893                         }
 894                 }
 895                 n = 0;
 896                 goto handled;
 897
 898         case LWSCM_WS_SERVING:
 899         case LWSCM_WS_CLIENT:
 900         case LWSCM_HTTP2_SERVING:
 901         case LWSCM_HTTP_CLIENT_ACCEPTED:
 902
 903                 /* 1: something requested a callback when it was OK to write */
 904
 905                 if ((pollfd->revents & LWS_POLLOUT) &&
 906                     ((wsi->state == LWSS_ESTABLISHED ||
 907                      wsi->state == LWSS_HTTP2_ESTABLISHED ||
 908                      wsi->state == LWSS_HTTP2_ESTABLISHED_PRE_SETTINGS ||
 909                      wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
 910                      wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE)) &&
 911                     lws_handle_POLLOUT_event(wsi, pollfd)) {
 912                         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
 913                                 wsi->state = LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE;
 914                         lwsl_info("lws_service_fd: closing\n");
 915                         goto close_and_handled;
 916                 }
 917
 918                 if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
 919                     wsi->state == LWSS_AWAITING_CLOSE_ACK) {
 920                         /*
 921                          * we stopped caring about anything except control
 922                          * packets.  Force flow control off, defeat tx
 923                          * draining.
 924                          */
 925                         lws_rx_flow_control(wsi, 1);
 926                         wsi->u.ws.tx_draining_ext = 0;
 927                 }
 928
 929                 if (wsi->u.ws.tx_draining_ext)
 930                         /* we cannot deal with new RX until the TX ext
 931                          * path has been drained.  It's because new
 932                          * rx will, eg, crap on the wsi rx buf that
 933                          * may be needed to retain state.
 934                          *
 935                          * TX ext drain path MUST go through event loop
 936                          * to avoid blocking.
 937                          */
 938                         break;
 939
 940                 if (!(wsi->rxflow_change_to & LWS_RXFLOW_ALLOW))
 941                         /* We cannot deal with any kind of new RX
 942                          * because we are RX-flowcontrolled.
 943                          */
 944                         break;
 945
 946                 /* 2: RX Extension needs to be drained
 947                  */
 948
 949                 if (wsi->state == LWSS_ESTABLISHED &&
 950                     wsi->u.ws.rx_draining_ext) {
 951
 952                         lwsl_ext("%s: RX EXT DRAINING: Service\n", __func__);
 953 #ifndef LWS_NO_CLIENT
 954                         if (wsi->mode == LWSCM_WS_CLIENT) {
 955                                 n = lws_client_rx_sm(wsi, 0);
 956                                 if (n < 0)
 957                                         /* we closed wsi */
 958                                         n = 0;
 959                         } else
 960 #endif
 961                                 n = lws_rx_sm(wsi, 0);
 962
 963                         goto handled;
 964                 }
 965
 966                 if (wsi->u.ws.rx_draining_ext)
 967                         /*
 968                          * We have RX EXT content to drain, but can't do it
 969                          * right now.  That means we cannot do anything lower
 970                          * priority either.
 971                          */
 972                         break;
 973
 974                 /* 3: RX Flowcontrol buffer needs to be drained
 975                  */
 976
 977                 if (wsi->rxflow_buffer) {
 978                         lwsl_info("draining rxflow (len %d)\n",
 979                                 wsi->rxflow_len - wsi->rxflow_pos
 980                         );
 981                         /* well, drain it */
 982                         eff_buf.token = (char *)wsi->rxflow_buffer +
 983                                                 wsi->rxflow_pos;
 984                         eff_buf.token_len = wsi->rxflow_len - wsi->rxflow_pos;
 985                         draining_flow = 1;
 986                         goto drain;
 987                 }
 988
 989                 /* 4: any incoming (or ah-stashed incoming rx) data ready?
 990                  * notice if rx flow going off raced poll(), rx flow wins
 991                  */
 992
 993                 if (!(pollfd->revents & pollfd->events & LWS_POLLIN))
 994                         break;
 995
 996 read:
 997                 /* all the union members start with hdr, so even in ws mode
 998                  * we can deal with the ah via u.hdr
 999                  */
1000                 if (wsi->u.hdr.ah) {
1001                         lwsl_info("%s: %p: inherited ah rx\n", __func__, wsi);
1002                         eff_buf.token_len = wsi->u.hdr.ah->rxlen -
1003                                             wsi->u.hdr.ah->rxpos;
1004                         eff_buf.token = (char *)wsi->u.hdr.ah->rx +
1005                                         wsi->u.hdr.ah->rxpos;
1006                 } else {
1007                         if (wsi->mode != LWSCM_HTTP_CLIENT_ACCEPTED) {
1008                                 eff_buf.token_len = lws_ssl_capable_read(wsi,
1009                                         pt->serv_buf, pending ? pending :
1010                                         context->pt_serv_buf_size);
1011                                 switch (eff_buf.token_len) {
1012                                 case 0:
1013                                         lwsl_info("%s: zero length read\n", __func__);
1014                                         goto close_and_handled;
1015                                 case LWS_SSL_CAPABLE_MORE_SERVICE:
1016                                         lwsl_info("SSL Capable more service\n");
1017                                         n = 0;
1018                                         goto handled;
1019                                 case LWS_SSL_CAPABLE_ERROR:
1020                                         lwsl_info("Closing when error\n");
1021                                         goto close_and_handled;
1022                                 }
1023
1024                                 eff_buf.token = (char *)pt->serv_buf;
1025                         }
1026                 }
1027
1028 drain:
1029 #ifndef LWS_NO_CLIENT
1030                 if (wsi->mode == LWSCM_HTTP_CLIENT_ACCEPTED &&
1031                     !wsi->told_user_closed) {
1032
1033                         /*
1034                          * In SSL mode we get POLLIN notification about
1035                          * encrypted data in.
1036                          *
1037                          * But that is not necessarily related to decrypted
1038                          * data out becoming available; in may need to perform
1039                          * other in or out before that happens.
1040                          *
1041                          * simply mark ourselves as having readable data
1042                          * and turn off our POLLIN
1043                          */
1044                         wsi->client_rx_avail = 1;
1045                         lws_change_pollfd(wsi, LWS_POLLIN, 0);
1046
1047                         /* let user code know, he'll usually ask for writeable
1048                          * callback and drain / re-enable it there
1049                          */
1050                         if (user_callback_handle_rxflow(
1051                                         wsi->protocol->callback,
1052                                         wsi, LWS_CALLBACK_RECEIVE_CLIENT_HTTP,
1053                                         wsi->user_space, NULL, 0)) {
1054                                 lwsl_debug("LWS_CALLBACK_RECEIVE_CLIENT_HTTP closed it\n");
1055                                 goto close_and_handled;
1056                         }
1057                 }
1058 #endif
1059                 /*
1060                  * give any active extensions a chance to munge the buffer
1061                  * before parse.  We pass in a pointer to an lws_tokens struct
1062                  * prepared with the default buffer and content length that's in
1063                  * there.  Rather than rewrite the default buffer, extensions
1064                  * that expect to grow the buffer can adapt .token to
1065                  * point to their own per-connection buffer in the extension
1066                  * user allocation.  By default with no extensions or no
1067                  * extension callback handling, just the normal input buffer is
1068                  * used then so it is efficient.
1069                  */
1070                 do {
1071                         more = 0;
1072
1073                         m = lws_ext_cb_active(wsi, LWS_EXT_CB_PACKET_RX_PREPARSE,
1074                                               &eff_buf, 0);
1075                         if (m < 0)
1076                                 goto close_and_handled;
1077                         if (m)
1078                                 more = 1;
1079
1080                         /* service incoming data */
1081
1082                         if (eff_buf.token_len) {
1083                                 /*
1084                                  * if draining from rxflow buffer, not
1085                                  * critical to track what was used since at the
1086                                  * use it bumps wsi->rxflow_pos.  If we come
1087                                  * around again it will pick up from where it
1088                                  * left off.
1089                                  */
1090                                 n = lws_read(wsi, (unsigned char *)eff_buf.token,
1091                                              eff_buf.token_len);
1092                                 if (n < 0) {
1093                                         /* we closed wsi */
1094                                         n = 0;
1095                                         goto handled;
1096                                 }
1097                         }
1098
1099                         eff_buf.token = NULL;
1100                         eff_buf.token_len = 0;
1101                 } while (more);
1102
1103                 if (wsi->u.hdr.ah) {
1104                         lwsl_notice("%s: %p: detaching\n",
1105                                  __func__, wsi);
1106                         /* show we used all the pending rx up */
1107                         wsi->u.hdr.ah->rxpos = wsi->u.hdr.ah->rxlen;
1108                         /* we can run the normal ah detach flow despite
1109                          * being in ws union mode, since all union members
1110                          * start with hdr */
1111                         lws_header_table_detach(wsi, 0);
1112                 }
1113
1114                 pending = lws_ssl_pending(wsi);
1115                 if (pending) {
1116                         pending = pending > context->pt_serv_buf_size ?
1117                                         context->pt_serv_buf_size : pending;
1118                         goto read;
1119                 }
1120
1121                 if (draining_flow && wsi->rxflow_buffer &&
1122                     wsi->rxflow_pos == wsi->rxflow_len) {
1123                         lwsl_info("flow buffer: drained\n");
1124                         lws_free_set_NULL(wsi->rxflow_buffer);
1125                         /* having drained the rxflow buffer, can rearm POLLIN */
1126 #ifdef LWS_NO_SERVER
1127                         n =
1128 #endif
1129                         _lws_rx_flow_control(wsi);
1130                         /* n ignored, needed for NO_SERVER case */
1131                 }
1132
1133                 break;
1134 #ifdef LWS_WITH_CGI
1135         case LWSCM_CGI: /* we exist to handle a cgi's stdin/out/err data...
1136                          * do the callback on our master wsi
1137                          */
1138                 {
1139                         struct lws_cgi_args args;
1140
1141                         if (wsi->cgi_channel >= LWS_STDOUT &&
1142                             !(pollfd->revents & pollfd->events & LWS_POLLIN))
1143                                 break;
1144                         if (wsi->cgi_channel == LWS_STDIN &&
1145                             !(pollfd->revents & pollfd->events & LWS_POLLOUT))
1146                                 break;
1147
1148                         if (wsi->cgi_channel == LWS_STDIN)
1149                                 if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
1150                                         lwsl_info("failed at set pollfd\n");
1151                                         return 1;
1152                                 }
1153
1154                         args.ch = wsi->cgi_channel;
1155                         args.stdwsi = &wsi->parent->cgi->stdwsi[0];
1156                         args.hdr_state = wsi->hdr_state;
1157
1158                         //lwsl_err("CGI LWS_STDOUT waiting wsi %p mode %d state %d\n",
1159                         //       wsi->parent, wsi->parent->mode, wsi->parent->state);
1160
1161                         if (user_callback_handle_rxflow(
1162                                         wsi->parent->protocol->callback,
1163                                         wsi->parent, LWS_CALLBACK_CGI,
1164                                         wsi->parent->user_space,
1165                                         (void *)&args, 0))
1166                                 return 1;
1167
1168                         break;
1169                 }
1170 #endif
1171         default:
1172 #ifdef LWS_NO_CLIENT
1173                 break;
1174 #else
1175                 if ((pollfd->revents & LWS_POLLOUT) &&
1176                     lws_handle_POLLOUT_event(wsi, pollfd)) {
1177                         lwsl_debug("POLLOUT event closed it\n");
1178                         goto close_and_handled;
1179                 }
1180
1181                 n = lws_client_socket_service(context, wsi, pollfd);
1182                 if (n)
1183                         return 1;
1184                 goto handled;
1185 #endif
1186         }
1187
1188         n = 0;
1189         goto handled;
1190
1191 close_and_handled:
1192         lwsl_debug("Close and handled\n");
1193         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
1194         /*
1195          * pollfd may point to something else after the close
1196          * due to pollfd swapping scheme on delete on some platforms
1197          * we can't clear revents now because it'd be the wrong guy's revents
1198          */
1199         return 1;
1200
1201 handled:
1202         pollfd->revents = 0;
1203         return n;
1204 }
1205
1206 LWS_VISIBLE int
1207 lws_service_fd(struct lws_context *context, struct lws_pollfd *pollfd)
1208 {
1209         return lws_service_fd_tsi(context, pollfd, 0);
1210 }
1211
1212 LWS_VISIBLE int
1213 lws_service(struct lws_context *context, int timeout_ms)
1214 {
1215         return lws_plat_service(context, timeout_ms);
1216 }
1217
1218 LWS_VISIBLE int
1219 lws_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
1220 {
1221         return _lws_plat_service_tsi(context, timeout_ms, tsi);
1222 }
1223