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         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
  28         int n;
  29
  30         lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_WRITEABLE_CB, 1);
  31 #if defined(LWS_WITH_STATS)
  32         {
  33                 uint64_t ul = time_in_microseconds() - wsi->active_writable_req_us;
  34
  35                 lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_MS_WRITABLE_DELAY, ul);
  36                 lws_stats_atomic_max(wsi->context, pt, LWSSTATS_MS_WORST_WRITABLE_DELAY, ul);
  37                 wsi->active_writable_req_us = 0;
  38         }
  39 #endif
  40
  41         switch (wsi->mode) {
  42         case LWSCM_RAW:
  43                 n = LWS_CALLBACK_RAW_WRITEABLE;
  44                 break;
  45         case LWSCM_RAW_FILEDESC:
  46                 n = LWS_CALLBACK_RAW_WRITEABLE_FILE;
  47                 break;
  48         case LWSCM_WS_CLIENT:
  49                 n = LWS_CALLBACK_CLIENT_WRITEABLE;
  50                 break;
  51         case LWSCM_WSCL_ISSUE_HTTP_BODY:
  52                 n = LWS_CALLBACK_CLIENT_HTTP_WRITEABLE;
  53                 break;
  54         case LWSCM_WS_SERVING:
  55                 n = LWS_CALLBACK_SERVER_WRITEABLE;
  56                 break;
  57         default:
  58                 n = LWS_CALLBACK_HTTP_WRITEABLE;
  59                 break;
  60         }
  61
  62         return user_callback_handle_rxflow(wsi->protocol->callback,
  63                                            wsi, (enum lws_callback_reasons) n,
  64                                            wsi->user_space, NULL, 0);
  65 }
  66
  67 LWS_VISIBLE int
  68 lws_handle_POLLOUT_event(struct lws *wsi, struct lws_pollfd *pollfd)
  69 {
  70         int write_type = LWS_WRITE_PONG;
  71         struct lws_tokens eff_buf;
  72 #ifdef LWS_USE_HTTP2
  73         struct lws *wsi2;
  74 #endif
  75         int ret, m, n;
  76
  77 //      lwsl_err("%s: %p\n", __func__, wsi);
  78
  79         wsi->leave_pollout_active = 0;
  80         wsi->handling_pollout = 1;
  81         /*
  82          * if another thread wants POLLOUT on us, from here on while
  83          * handling_pollout is set, he will only set leave_pollout_active.
  84          * If we are going to disable POLLOUT, we will check that first.
  85          */
  86
  87         /*
  88          * user callback is lowest priority to get these notifications
  89          * actually, since other pending things cannot be disordered
  90          */
  91
  92         /* Priority 1: pending truncated sends are incomplete ws fragments
  93          *             If anything else sent first the protocol would be
  94          *             corrupted.
  95          */
  96         if (wsi->trunc_len) {
  97                 if (lws_issue_raw(wsi, wsi->trunc_alloc + wsi->trunc_offset,
  98                                   wsi->trunc_len) < 0) {
  99                         lwsl_info("%s signalling to close\n", __func__);
 100                         goto bail_die;
 101                 }
 102                 /* leave POLLOUT active either way */
 103                 goto bail_ok;
 104         } else
 105                 if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE) {
 106                         wsi->socket_is_permanently_unusable = 1;
 107                         goto bail_die; /* retry closing now */
 108                 }
 109
 110         if (wsi->mode == LWSCM_WSCL_ISSUE_HTTP_BODY)
 111                 goto user_service;
 112
 113
 114 #ifdef LWS_USE_HTTP2
 115         /* Priority 2: protocol packets
 116          */
 117         if (wsi->pps) {
 118                 lwsl_info("servicing pps %d\n", wsi->pps);
 119                 switch (wsi->pps) {
 120                 case LWS_PPS_HTTP2_MY_SETTINGS:
 121                 case LWS_PPS_HTTP2_ACK_SETTINGS:
 122                         lws_http2_do_pps_send(lws_get_context(wsi), wsi);
 123                         break;
 124                 default:
 125                         break;
 126                 }
 127                 wsi->pps = LWS_PPS_NONE;
 128                 lws_rx_flow_control(wsi, 1);
 129
 130                 goto bail_ok; /* leave POLLOUT active */
 131         }
 132 #endif
 133
 134 #ifdef LWS_WITH_CGI
 135         if (wsi->cgi) {
 136                 /* also one shot */
 137                 if (pollfd)
 138                         if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
 139                                 lwsl_info("failed at set pollfd\n");
 140                                 return 1;
 141                         }
 142                 goto user_service_go_again;
 143         }
 144 #endif
 145
 146         /* Priority 3: pending control packets (pong or close)
 147          *
 148          * 3a: close notification packet requested from close api
 149          */
 150
 151         if (wsi->state == LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION) {
 152                 lwsl_debug("sending close packet\n");
 153                 wsi->waiting_to_send_close_frame = 0;
 154                 n = lws_write(wsi, &wsi->u.ws.ping_payload_buf[LWS_PRE],
 155                               wsi->u.ws.close_in_ping_buffer_len,
 156                               LWS_WRITE_CLOSE);
 157                 if (n >= 0) {
 158                         wsi->state = LWSS_AWAITING_CLOSE_ACK;
 159                         lws_set_timeout(wsi, PENDING_TIMEOUT_CLOSE_ACK, 1);
 160                         lwsl_debug("sent close indication, awaiting ack\n");
 161
 162                         goto bail_ok;
 163                 }
 164
 165                 goto bail_die;
 166         }
 167
 168         /* else, the send failed and we should just hang up */
 169
 170         if ((wsi->state == LWSS_ESTABLISHED &&
 171              wsi->u.ws.ping_pending_flag) ||
 172             (wsi->state == LWSS_RETURNED_CLOSE_ALREADY &&
 173              wsi->u.ws.payload_is_close)) {
 174
 175                 if (wsi->u.ws.payload_is_close)
 176                         write_type = LWS_WRITE_CLOSE;
 177
 178                 n = lws_write(wsi, &wsi->u.ws.ping_payload_buf[LWS_PRE],
 179                               wsi->u.ws.ping_payload_len, write_type);
 180                 if (n < 0)
 181                         goto bail_die;
 182
 183                 /* well he is sent, mark him done */
 184                 wsi->u.ws.ping_pending_flag = 0;
 185                 if (wsi->u.ws.payload_is_close)
 186                         /* oh... a close frame was it... then we are done */
 187                         goto bail_die;
 188
 189                 /* otherwise for PING, leave POLLOUT active either way */
 190                 goto bail_ok;
 191         }
 192
 193         if (wsi->state == LWSS_ESTABLISHED &&
 194             !wsi->socket_is_permanently_unusable &&
 195             wsi->u.ws.send_check_ping) {
 196
 197                 lwsl_info("issuing ping on wsi %p\n", wsi);
 198                 wsi->u.ws.send_check_ping = 0;
 199                 n = lws_write(wsi, &wsi->u.ws.ping_payload_buf[LWS_PRE],
 200                               0, LWS_WRITE_PING);
 201                 if (n < 0)
 202                         goto bail_die;
 203
 204                 /*
 205                  * we apparently were able to send the PING in a reasonable time
 206                  * now reset the clock on our peer to be able to send the
 207                  * PONG in a reasonable time.
 208                  */
 209
 210                 lws_set_timeout(wsi, PENDING_TIMEOUT_WS_PONG_CHECK_GET_PONG,
 211                                 wsi->context->timeout_secs);
 212
 213                 goto bail_ok;
 214         }
 215
 216         /* Priority 4: if we are closing, not allowed to send more data frags
 217          *             which means user callback or tx ext flush banned now
 218          */
 219         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
 220                 goto user_service;
 221
 222         /* Priority 5: Tx path extension with more to send
 223          *
 224          *             These are handled as new fragments each time around
 225          *             So while we must block new writeable callback to enforce
 226          *             payload ordering, but since they are always complete
 227          *             fragments control packets can interleave OK.
 228          */
 229         if (wsi->state == LWSS_ESTABLISHED && wsi->u.ws.tx_draining_ext) {
 230                 lwsl_ext("SERVICING TX EXT DRAINING\n");
 231                 if (lws_write(wsi, NULL, 0, LWS_WRITE_CONTINUATION) < 0)
 232                         goto bail_die;
 233                 /* leave POLLOUT active */
 234                 goto bail_ok;
 235         }
 236
 237         /* Priority 6: user can get the callback
 238          */
 239         m = lws_ext_cb_active(wsi, LWS_EXT_CB_IS_WRITEABLE, NULL, 0);
 240         if (m)
 241                 goto bail_die;
 242 #ifndef LWS_NO_EXTENSIONS
 243         if (!wsi->extension_data_pending)
 244                 goto user_service;
 245 #endif
 246         /*
 247          * check in on the active extensions, see if they
 248          * had pending stuff to spill... they need to get the
 249          * first look-in otherwise sequence will be disordered
 250          *
 251          * NULL, zero-length eff_buf means just spill pending
 252          */
 253
 254         ret = 1;
 255         if (wsi->mode == LWSCM_RAW || wsi->mode == LWSCM_RAW_FILEDESC)
 256                 ret = 0;
 257         while (ret == 1) {
 258
 259                 /* default to nobody has more to spill */
 260
 261                 ret = 0;
 262                 eff_buf.token = NULL;
 263                 eff_buf.token_len = 0;
 264
 265                 /* give every extension a chance to spill */
 266
 267                 m = lws_ext_cb_active(wsi,
 268                                         LWS_EXT_CB_PACKET_TX_PRESEND,
 269                                                &eff_buf, 0);
 270                 if (m < 0) {
 271                         lwsl_err("ext reports fatal error\n");
 272                         goto bail_die;
 273                 }
 274                 if (m)
 275                         /*
 276                          * at least one extension told us he has more
 277                          * to spill, so we will go around again after
 278                          */
 279                         ret = 1;
 280
 281                 /* assuming they gave us something to send, send it */
 282
 283                 if (eff_buf.token_len) {
 284                         n = lws_issue_raw(wsi, (unsigned char *)eff_buf.token,
 285                                           eff_buf.token_len);
 286                         if (n < 0) {
 287                                 lwsl_info("closing from POLLOUT spill\n");
 288                                 goto bail_die;
 289                         }
 290                         /*
 291                          * Keep amount spilled small to minimize chance of this
 292                          */
 293                         if (n != eff_buf.token_len) {
 294                                 lwsl_err("Unable to spill ext %d vs %d\n",
 295                                                           eff_buf.token_len, n);
 296                                 goto bail_die;
 297                         }
 298                 } else
 299                         continue;
 300
 301                 /* no extension has more to spill */
 302
 303                 if (!ret)
 304                         continue;
 305
 306                 /*
 307                  * There's more to spill from an extension, but we just sent
 308                  * something... did that leave the pipe choked?
 309                  */
 310
 311                 if (!lws_send_pipe_choked(wsi))
 312                         /* no we could add more */
 313                         continue;
 314
 315                 lwsl_info("choked in POLLOUT service\n");
 316
 317                 /*
 318                  * Yes, he's choked.  Leave the POLLOUT masked on so we will
 319                  * come back here when he is unchoked.  Don't call the user
 320                  * callback to enforce ordering of spilling, he'll get called
 321                  * when we come back here and there's nothing more to spill.
 322                  */
 323
 324                 goto bail_ok;
 325         }
 326 #ifndef LWS_NO_EXTENSIONS
 327         wsi->extension_data_pending = 0;
 328 #endif
 329 user_service:
 330         /* one shot */
 331
 332         if (pollfd) {
 333                 int eff = wsi->leave_pollout_active;
 334
 335                 if (!eff)
 336                         if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
 337                                 lwsl_info("failed at set pollfd\n");
 338                                 goto bail_die;
 339                         }
 340
 341                 wsi->handling_pollout = 0;
 342
 343                 /* cannot get leave_pollout_active set after the above */
 344                 if (!eff && wsi->leave_pollout_active)
 345                         /* got set inbetween sampling eff and clearing
 346                          * handling_pollout, force POLLOUT on */
 347                         lws_calllback_as_writeable(wsi);
 348
 349                 wsi->leave_pollout_active = 0;
 350         }
 351
 352         if (wsi->mode != LWSCM_WSCL_ISSUE_HTTP_BODY &&
 353             !wsi->hdr_parsing_completed)
 354                 goto bail_ok;
 355
 356
 357 #ifdef LWS_WITH_CGI
 358 user_service_go_again:
 359 #endif
 360
 361 #ifdef LWS_USE_HTTP2
 362         /*
 363          * we are the 'network wsi' for potentially many muxed child wsi with
 364          * no network connection of their own, who have to use us for all their
 365          * network actions.  So we use a round-robin scheme to share out the
 366          * POLLOUT notifications to our children.
 367          *
 368          * But because any child could exhaust the socket's ability to take
 369          * writes, we can only let one child get notified each time.
 370          *
 371          * In addition children may be closed / deleted / added between POLLOUT
 372          * notifications, so we can't hold pointers
 373          */
 374
 375         if (wsi->mode != LWSCM_HTTP2_SERVING) {
 376                 lwsl_info("%s: non http2\n", __func__);
 377                 goto notify;
 378         }
 379
 380         wsi->u.http2.requested_POLLOUT = 0;
 381         if (!wsi->u.http2.initialized) {
 382                 lwsl_info("pollout on uninitialized http2 conn\n");
 383                 goto bail_ok;
 384         }
 385
 386         lwsl_info("%s: doing children\n", __func__);
 387
 388         wsi2 = wsi;
 389         do {
 390                 wsi2 = wsi2->u.http2.next_child_wsi;
 391                 lwsl_info("%s: child %p\n", __func__, wsi2);
 392                 if (!wsi2)
 393                         continue;
 394                 if (!wsi2->u.http2.requested_POLLOUT)
 395                         continue;
 396                 wsi2->u.http2.requested_POLLOUT = 0;
 397                 if (lws_calllback_as_writeable(wsi2)) {
 398                         lwsl_debug("Closing POLLOUT child\n");
 399                         lws_close_free_wsi(wsi2, LWS_CLOSE_STATUS_NOSTATUS);
 400                 }
 401                 wsi2 = wsi;
 402         } while (wsi2 != NULL && !lws_send_pipe_choked(wsi));
 403
 404         lwsl_info("%s: completed\n", __func__);
 405
 406         goto bail_ok;
 407 notify:
 408 #endif
 409         wsi->handling_pollout = 0;
 410         wsi->leave_pollout_active = 0;
 411
 412         return lws_calllback_as_writeable(wsi);
 413
 414         /*
 415          * since these don't disable the POLLOUT, they are always doing the
 416          * right thing for leave_pollout_active whether it was set or not.
 417          */
 418
 419 bail_ok:
 420         wsi->handling_pollout = 0;
 421         wsi->leave_pollout_active = 0;
 422
 423         return 0;
 424
 425 bail_die:
 426         wsi->handling_pollout = 0;
 427         wsi->leave_pollout_active = 0;
 428
 429         return -1;
 430 }
 431
 432 int
 433 lws_service_timeout_check(struct lws *wsi, unsigned int sec)
 434 {
 435 //#if LWS_POSIX
 436         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 437         int n = 0;
 438 //#endif
 439
 440         (void)n;
 441
 442         /*
 443          * if extensions want in on it (eg, we are a mux parent)
 444          * give them a chance to service child timeouts
 445          */
 446         if (lws_ext_cb_active(wsi, LWS_EXT_CB_1HZ, NULL, sec) < 0)
 447                 return 0;
 448
 449         if (!wsi->pending_timeout)
 450                 return 0;
 451
 452         /*
 453          * if we went beyond the allowed time, kill the
 454          * connection
 455          */
 456         if ((time_t)sec > wsi->pending_timeout_limit) {
 457 //#if LWS_POSIX
 458                 if (wsi->desc.sockfd != LWS_SOCK_INVALID && wsi->position_in_fds_table >= 0)
 459                         n = pt->fds[wsi->position_in_fds_table].events;
 460
 461                 lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_TIMEOUTS, 1);
 462
 463                 /* no need to log normal idle keepalive timeout */
 464                 if (wsi->pending_timeout != PENDING_TIMEOUT_HTTP_KEEPALIVE_IDLE)
 465                         lwsl_notice("wsi %p: TIMEDOUT WAITING on %d (did hdr %d, ah %p, wl %d, pfd events %d) %llu vs %llu\n",
 466                             (void *)wsi, wsi->pending_timeout,
 467                             wsi->hdr_parsing_completed, wsi->u.hdr.ah,
 468                             pt->ah_wait_list_length, n, (unsigned long long)sec, (unsigned long long)wsi->pending_timeout_limit);
 469 //#endif
 470                 /*
 471                  * Since he failed a timeout, he already had a chance to do
 472                  * something and was unable to... that includes situations like
 473                  * half closed connections.  So process this "failed timeout"
 474                  * close as a violent death and don't try to do protocol
 475                  * cleanup like flush partials.
 476                  */
 477                 wsi->socket_is_permanently_unusable = 1;
 478                 if (wsi->mode == LWSCM_WSCL_WAITING_SSL)
 479                         wsi->vhost->protocols[0].callback(wsi,
 480                                 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
 481                                 wsi->user_space, (void *)"Timed out waiting SSL", 21);
 482
 483                 lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
 484
 485                 return 1;
 486         }
 487
 488         return 0;
 489 }
 490
 491 int lws_rxflow_cache(struct lws *wsi, unsigned char *buf, int n, int len)
 492 {
 493         /* his RX is flowcontrolled, don't send remaining now */
 494         if (wsi->rxflow_buffer) {
 495                 /* rxflow while we were spilling prev rxflow */
 496                 lwsl_info("stalling in existing rxflow buf\n");
 497                 return 1;
 498         }
 499
 500         /* a new rxflow, buffer it and warn caller */
 501         lwsl_info("new rxflow input buffer len %d\n", len - n);
 502         wsi->rxflow_buffer = lws_malloc(len - n);
 503         if (!wsi->rxflow_buffer)
 504                 return -1;
 505         wsi->rxflow_len = len - n;
 506         wsi->rxflow_pos = 0;
 507         memcpy(wsi->rxflow_buffer, buf + n, len - n);
 508
 509         return 0;
 510 }
 511
 512 /* this is used by the platform service code to stop us waiting for network
 513  * activity in poll() when we have something that already needs service
 514  */
 515
 516 LWS_VISIBLE LWS_EXTERN int
 517 lws_service_adjust_timeout(struct lws_context *context, int timeout_ms, int tsi)
 518 {
 519         struct lws_context_per_thread *pt = &context->pt[tsi];
 520         int n;
 521
 522         /* Figure out if we really want to wait in poll()
 523          * We only need to wait if really nothing already to do and we have
 524          * to wait for something from network
 525          */
 526
 527         /* 1) if we know we are draining rx ext, do not wait in poll */
 528         if (pt->rx_draining_ext_list)
 529                 return 0;
 530
 531 #ifdef LWS_OPENSSL_SUPPORT
 532         /* 2) if we know we have non-network pending data, do not wait in poll */
 533         if (lws_ssl_anybody_has_buffered_read_tsi(context, tsi)) {
 534                 lwsl_info("ssl buffered read\n");
 535                 return 0;
 536         }
 537 #endif
 538
 539         /* 3) if any ah has pending rx, do not wait in poll */
 540         for (n = 0; n < context->max_http_header_pool; n++)
 541                 if (pt->ah_pool[n].rxpos != pt->ah_pool[n].rxlen) {
 542                         /* any ah with pending rx must be attached to someone */
 543                         if (!pt->ah_pool[n].wsi) {
 544                                 lwsl_err("%s: assert: no wsi attached to ah\n", __func__);
 545                                 assert(0);
 546                         }
 547                         return 0;
 548                 }
 549
 550         return timeout_ms;
 551 }
 552
 553 /*
 554  * guys that need POLLIN service again without waiting for network action
 555  * can force POLLIN here if not flowcontrolled, so they will get service.
 556  *
 557  * Return nonzero if anybody got their POLLIN faked
 558  */
 559 int
 560 lws_service_flag_pending(struct lws_context *context, int tsi)
 561 {
 562         struct lws_context_per_thread *pt = &context->pt[tsi];
 563 #ifdef LWS_OPENSSL_SUPPORT
 564         struct lws *wsi_next;
 565 #endif
 566         struct lws *wsi;
 567         int forced = 0;
 568         int n;
 569
 570         /* POLLIN faking */
 571
 572         /*
 573          * 1) For all guys with already-available ext data to drain, if they are
 574          * not flowcontrolled, fake their POLLIN status
 575          */
 576         wsi = pt->rx_draining_ext_list;
 577         while (wsi) {
 578                 pt->fds[wsi->position_in_fds_table].revents |=
 579                         pt->fds[wsi->position_in_fds_table].events & LWS_POLLIN;
 580                 if (pt->fds[wsi->position_in_fds_table].revents & LWS_POLLIN) {
 581                         forced = 1;
 582                         break;
 583                 }
 584                 wsi = wsi->u.ws.rx_draining_ext_list;
 585         }
 586
 587 #ifdef LWS_OPENSSL_SUPPORT
 588         /*
 589          * 2) For all guys with buffered SSL read data already saved up, if they
 590          * are not flowcontrolled, fake their POLLIN status so they'll get
 591          * service to use up the buffered incoming data, even though their
 592          * network socket may have nothing
 593          */
 594         wsi = pt->pending_read_list;
 595         while (wsi) {
 596                 wsi_next = wsi->pending_read_list_next;
 597                 pt->fds[wsi->position_in_fds_table].revents |=
 598                         pt->fds[wsi->position_in_fds_table].events & LWS_POLLIN;
 599                 if (pt->fds[wsi->position_in_fds_table].revents & LWS_POLLIN) {
 600                         forced = 1;
 601                         /*
 602                          * he's going to get serviced now, take him off the
 603                          * list of guys with buffered SSL.  If he still has some
 604                          * at the end of the service, he'll get put back on the
 605                          * list then.
 606                          */
 607                         lws_ssl_remove_wsi_from_buffered_list(wsi);
 608                 }
 609
 610                 wsi = wsi_next;
 611         }
 612 #endif
 613         /*
 614          * 3) For any wsi who have an ah with pending RX who did not
 615          * complete their current headers, and are not flowcontrolled,
 616          * fake their POLLIN status so they will be able to drain the
 617          * rx buffered in the ah
 618          */
 619         for (n = 0; n < context->max_http_header_pool; n++)
 620                 if (pt->ah_pool[n].rxpos != pt->ah_pool[n].rxlen &&
 621                     !pt->ah_pool[n].wsi->hdr_parsing_completed) {
 622                         pt->fds[pt->ah_pool[n].wsi->position_in_fds_table].revents |=
 623                                 pt->fds[pt->ah_pool[n].wsi->position_in_fds_table].events &
 624                                         LWS_POLLIN;
 625                         if (pt->fds[pt->ah_pool[n].wsi->position_in_fds_table].revents &
 626                             LWS_POLLIN)
 627                                 forced = 1;
 628                 }
 629
 630         return forced;
 631 }
 632
 633 #ifndef LWS_NO_CLIENT
 634
 635 LWS_VISIBLE int
 636 lws_http_client_read(struct lws *wsi, char **buf, int *len)
 637 {
 638         int rlen, n;
 639
 640         rlen = lws_ssl_capable_read(wsi, (unsigned char *)*buf, *len);
 641         *len = 0;
 642
 643         /* allow the source to signal he has data again next time */
 644         lws_change_pollfd(wsi, 0, LWS_POLLIN);
 645
 646         if (rlen == LWS_SSL_CAPABLE_ERROR) {
 647                 lwsl_notice("%s: SSL capable error\n", __func__);
 648                 return -1;
 649         }
 650
 651         if (rlen == 0)
 652                 return -1;
 653
 654         if (rlen < 0)
 655                 return 0;
 656
 657         *len = rlen;
 658         wsi->client_rx_avail = 0;
 659
 660         /*
 661          * server may insist on transfer-encoding: chunked,
 662          * so http client must deal with it
 663          */
 664 spin_chunks:
 665         while (wsi->chunked && (wsi->chunk_parser != ELCP_CONTENT) && *len) {
 666                 switch (wsi->chunk_parser) {
 667                 case ELCP_HEX:
 668                         if ((*buf)[0] == '\x0d') {
 669                                 wsi->chunk_parser = ELCP_CR;
 670                                 break;
 671                         }
 672                         n = char_to_hex((*buf)[0]);
 673                         if (n < 0) {
 674                                 lwsl_debug("chunking failure\n");
 675                                 return -1;
 676                         }
 677                         wsi->chunk_remaining <<= 4;
 678                         wsi->chunk_remaining |= n;
 679                         break;
 680                 case ELCP_CR:
 681                         if ((*buf)[0] != '\x0a') {
 682                                 lwsl_debug("chunking failure\n");
 683                                 return -1;
 684                         }
 685                         wsi->chunk_parser = ELCP_CONTENT;
 686                         lwsl_info("chunk %d\n", wsi->chunk_remaining);
 687                         if (wsi->chunk_remaining)
 688                                 break;
 689                         lwsl_info("final chunk\n");
 690                         goto completed;
 691
 692                 case ELCP_CONTENT:
 693                         break;
 694
 695                 case ELCP_POST_CR:
 696                         if ((*buf)[0] != '\x0d') {
 697                                 lwsl_debug("chunking failure\n");
 698
 699                                 return -1;
 700                         }
 701
 702                         wsi->chunk_parser = ELCP_POST_LF;
 703                         break;
 704
 705                 case ELCP_POST_LF:
 706                         if ((*buf)[0] != '\x0a')
 707                                 return -1;
 708
 709                         wsi->chunk_parser = ELCP_HEX;
 710                         wsi->chunk_remaining = 0;
 711                         break;
 712                 }
 713                 (*buf)++;
 714                 (*len)--;
 715         }
 716
 717         if (wsi->chunked && !wsi->chunk_remaining)
 718                 return 0;
 719
 720         if (wsi->u.http.content_remain &&
 721             wsi->u.http.content_remain < *len)
 722                 n = (int)wsi->u.http.content_remain;
 723         else
 724                 n = *len;
 725
 726         if (wsi->chunked && wsi->chunk_remaining &&
 727             wsi->chunk_remaining < n)
 728                 n = wsi->chunk_remaining;
 729
 730 #ifdef LWS_WITH_HTTP_PROXY
 731         /* hubbub */
 732         if (wsi->perform_rewrite)
 733                 lws_rewrite_parse(wsi->rw, (unsigned char *)*buf, n);
 734         else
 735 #endif
 736                 if (user_callback_handle_rxflow(wsi->protocol->callback,
 737                                 wsi, LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ,
 738                                 wsi->user_space, *buf, n)) {
 739                         lwsl_debug("%s: LWS_CALLBACK_RECEIVE_CLIENT_HTTP_READ returned -1\n", __func__);
 740
 741                         return -1;
 742                 }
 743
 744         if (wsi->chunked && wsi->chunk_remaining) {
 745                 (*buf) += n;
 746                 wsi->chunk_remaining -= n;
 747                 *len -= n;
 748         }
 749
 750         if (wsi->chunked && !wsi->chunk_remaining)
 751                 wsi->chunk_parser = ELCP_POST_CR;
 752
 753         if (wsi->chunked && *len)
 754                 goto spin_chunks;
 755
 756         if (wsi->chunked)
 757                 return 0;
 758
 759         /* if we know the content length, decrement the content remaining */
 760         if (wsi->u.http.content_length > 0)
 761                 wsi->u.http.content_remain -= n;
 762
 763         if (wsi->u.http.content_remain || !wsi->u.http.content_length)
 764                 return 0;
 765
 766 completed:
 767         if (user_callback_handle_rxflow(wsi->protocol->callback,
 768                         wsi, LWS_CALLBACK_COMPLETED_CLIENT_HTTP,
 769                         wsi->user_space, NULL, 0)) {
 770                 lwsl_debug("Completed call returned -1\n");
 771                 return -1;
 772         }
 773
 774         if (lws_http_transaction_completed_client(wsi)) {
 775                 lwsl_notice("%s: transaction completed says -1\n", __func__);
 776                 return -1;
 777         }
 778
 779         return 0;
 780 }
 781 #endif
 782
 783 static int
 784 lws_is_ws_with_ext(struct lws *wsi)
 785 {
 786 #if defined(LWS_NO_EXTENSIONS)
 787         return 0;
 788 #else
 789         return wsi->state == LWSS_ESTABLISHED &&
 790                !!wsi->count_act_ext;
 791 #endif
 792 }
 793
 794 LWS_VISIBLE int
 795 lws_service_fd_tsi(struct lws_context *context, struct lws_pollfd *pollfd, int tsi)
 796 {
 797         struct lws_context_per_thread *pt = &context->pt[tsi];
 798         lws_sockfd_type our_fd = 0, tmp_fd;
 799         struct lws_tokens eff_buf;
 800         unsigned int pending = 0;
 801         struct lws *wsi, *wsi1;
 802         char draining_flow = 0;
 803         int timed_out = 0;
 804         time_t now;
 805         int n = 0, m;
 806         int more;
 807
 808         if (!context->protocol_init_done)
 809                 lws_protocol_init(context);
 810
 811         time(&now);
 812
 813         /*
 814          * handle case that system time was uninitialized when lws started
 815          * at boot, and got initialized a little later
 816          */
 817         if (context->time_up < 1464083026 && now > 1464083026)
 818                 context->time_up = now;
 819
 820         /* TODO: if using libev, we should probably use timeout watchers... */
 821         if (context->last_timeout_check_s != now) {
 822                 context->last_timeout_check_s = now;
 823
 824 #if defined(LWS_WITH_STATS)
 825                 if (!tsi && now - context->last_dump > 10) {
 826                         lws_stats_log_dump(context);
 827                         context->last_dump = now;
 828                 }
 829 #endif
 830
 831                 lws_plat_service_periodic(context);
 832
 833                 lws_check_deferred_free(context, 0);
 834
 835                 /* retire unused deprecated context */
 836 #if !defined(LWS_PLAT_OPTEE) && !defined(LWS_WITH_ESP32)
 837 #if LWS_POSIX && !defined(_WIN32)
 838                 if (context->deprecated && !context->count_wsi_allocated) {
 839                         lwsl_notice("%s: ending deprecated context\n", __func__);
 840                         kill(getpid(), SIGINT);
 841                         return 0;
 842                 }
 843 #endif
 844 #endif
 845                 /* global timeout check once per second */
 846
 847                 if (pollfd)
 848                         our_fd = pollfd->fd;
 849
 850                 wsi = context->pt[tsi].timeout_list;
 851                 while (wsi) {
 852                         /* we have to take copies, because he may be deleted */
 853                         wsi1 = wsi->timeout_list;
 854                         tmp_fd = wsi->desc.sockfd;
 855                         if (lws_service_timeout_check(wsi, (unsigned int)now)) {
 856                                 /* he did time out... */
 857                                 if (tmp_fd == our_fd)
 858                                         /* it was the guy we came to service! */
 859                                         timed_out = 1;
 860                                         /* he's gone, no need to mark as handled */
 861                         }
 862                         wsi = wsi1;
 863                 }
 864 #ifdef LWS_WITH_CGI
 865                 lws_cgi_kill_terminated(pt);
 866 #endif
 867 #if 0
 868                 {
 869                         char s[300], *p = s;
 870
 871                         for (n = 0; n < context->count_threads; n++)
 872                                 p += sprintf(p, " %7lu (%5d), ",
 873                                              context->pt[n].count_conns,
 874                                              context->pt[n].fds_count);
 875
 876                         lwsl_notice("load: %s\n", s);
 877                 }
 878 #endif
 879         }
 880
 881         /*
 882          * at intervals, check for ws connections needing ping-pong checks
 883          */
 884
 885         if (context->ws_ping_pong_interval &&
 886             context->last_ws_ping_pong_check_s < now + 10) {
 887                 struct lws_vhost *vh = context->vhost_list;
 888                 context->last_ws_ping_pong_check_s = now;
 889
 890                 while (vh) {
 891                         for (n = 0; n < vh->count_protocols; n++) {
 892                                 wsi = vh->same_vh_protocol_list[n];
 893
 894                                 while (wsi) {
 895                                         if (wsi->state == LWSS_ESTABLISHED &&
 896                                             !wsi->socket_is_permanently_unusable &&
 897                                             !wsi->u.ws.send_check_ping &&
 898                                             wsi->u.ws.time_next_ping_check &&
 899                                             wsi->u.ws.time_next_ping_check < now) {
 900
 901                                                 lwsl_info("requesting ping-pong on wsi %p\n", wsi);
 902                                                 wsi->u.ws.send_check_ping = 1;
 903                                                 lws_set_timeout(wsi, PENDING_TIMEOUT_WS_PONG_CHECK_SEND_PING,
 904                                                                 context->timeout_secs);
 905                                                 lws_callback_on_writable(wsi);
 906                                                 wsi->u.ws.time_next_ping_check = now +
 907                                                                 wsi->context->ws_ping_pong_interval;
 908                                         }
 909                                         wsi = wsi->same_vh_protocol_next;
 910                                 }
 911                         }
 912                         vh = vh->vhost_next;
 913                 }
 914         }
 915
 916         /* the socket we came to service timed out, nothing to do */
 917         if (timed_out)
 918                 return 0;
 919
 920         /* just here for timeout management? */
 921         if (!pollfd)
 922                 return 0;
 923
 924         /* no, here to service a socket descriptor */
 925         wsi = wsi_from_fd(context, pollfd->fd);
 926         if (!wsi)
 927                 /* not lws connection ... leave revents alone and return */
 928                 return 0;
 929
 930         /*
 931          * so that caller can tell we handled, past here we need to
 932          * zero down pollfd->revents after handling
 933          */
 934
 935 #if LWS_POSIX
 936         /* handle session socket closed */
 937
 938         if ((!(pollfd->revents & pollfd->events & LWS_POLLIN)) &&
 939             (pollfd->revents & LWS_POLLHUP)) {
 940                 wsi->socket_is_permanently_unusable = 1;
 941                 lwsl_debug("Session Socket %p (fd=%d) dead\n",
 942                                                        (void *)wsi, pollfd->fd);
 943
 944                 goto close_and_handled;
 945         }
 946
 947 #ifdef _WIN32
 948         if (pollfd->revents & LWS_POLLOUT)
 949                 wsi->sock_send_blocking = FALSE;
 950 #endif
 951
 952 #endif
 953
 954 //       lwsl_debug("fd=%d, revents=%d, mode=%d, state=%d\n", pollfd->fd, pollfd->revents, (int)wsi->mode, (int)wsi->state);
 955         if (pollfd->revents & LWS_POLLHUP) {
 956                 lwsl_debug("pollhup\n");
 957                 wsi->socket_is_permanently_unusable = 1;
 958                 goto close_and_handled;
 959         }
 960
 961
 962 #ifdef LWS_OPENSSL_SUPPORT
 963         if ((wsi->state == LWSS_SHUTDOWN) && lws_is_ssl(wsi) && wsi->ssl)
 964         {
 965                 n = SSL_shutdown(wsi->ssl);
 966                 lwsl_debug("SSL_shutdown=%d for fd %d\n", n, wsi->desc.sockfd);
 967                 if (n == 1)
 968                 {
 969                         n = shutdown(wsi->desc.sockfd, SHUT_WR);
 970                         goto close_and_handled;
 971                 }
 972                 else if (n == 0)
 973                 {
 974                         lws_change_pollfd(wsi, LWS_POLLOUT, LWS_POLLIN);
 975                         n = 0;
 976                         goto handled;
 977                 }
 978                 else /* n < 0 */
 979                 {
 980                         int shutdown_error = SSL_get_error(wsi->ssl, n);
 981                         lwsl_debug("SSL_shutdown returned %d, SSL_get_error: %d\n", n, shutdown_error);
 982                         if (shutdown_error == SSL_ERROR_WANT_READ) {
 983                                 lws_change_pollfd(wsi, LWS_POLLOUT, LWS_POLLIN);
 984                                 n = 0;
 985                                 goto handled;
 986                         } else if (shutdown_error == SSL_ERROR_WANT_WRITE) {
 987                                 lws_change_pollfd(wsi, LWS_POLLOUT, LWS_POLLOUT);
 988                                 n = 0;
 989                                 goto handled;
 990                         }
 991
 992                         // actual error occurred, just close the connection
 993                         n = shutdown(wsi->desc.sockfd, SHUT_WR);
 994                         goto close_and_handled;
 995                 }
 996         }
 997 #endif
 998
 999         /* okay, what we came here to do... */
1000
1001         switch (wsi->mode) {
1002         case LWSCM_HTTP_SERVING:
1003         case LWSCM_HTTP_CLIENT:
1004         case LWSCM_HTTP_SERVING_ACCEPTED:
1005         case LWSCM_SERVER_LISTENER:
1006         case LWSCM_SSL_ACK_PENDING:
1007         case LWSCM_SSL_ACK_PENDING_RAW:
1008                 if (wsi->state == LWSS_CLIENT_HTTP_ESTABLISHED)
1009                         goto handled;
1010
1011 #ifdef LWS_WITH_CGI
1012                 if (wsi->cgi && (pollfd->revents & LWS_POLLOUT)) {
1013                         n = lws_handle_POLLOUT_event(wsi, pollfd);
1014                         if (n)
1015                                 goto close_and_handled;
1016                         goto handled;
1017                 }
1018 #endif
1019                 /* fallthru */
1020         case LWSCM_RAW:
1021                 n = lws_server_socket_service(context, wsi, pollfd);
1022                 if (n) /* closed by above */
1023                         return 1;
1024                 goto handled;
1025
1026         case LWSCM_RAW_FILEDESC:
1027
1028                 if (pollfd->revents & LWS_POLLOUT) {
1029                         n = lws_calllback_as_writeable(wsi);
1030                         if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
1031                                 lwsl_info("failed at set pollfd\n");
1032                                 return 1;
1033                         }
1034                         if (n)
1035                                 goto close_and_handled;
1036                 }
1037                 n = LWS_CALLBACK_RAW_RX;
1038                 if (wsi->mode == LWSCM_RAW_FILEDESC)
1039                         n = LWS_CALLBACK_RAW_RX_FILE;
1040
1041                 if (pollfd->revents & LWS_POLLIN) {
1042                         if (user_callback_handle_rxflow(
1043                                         wsi->protocol->callback,
1044                                         wsi, n,
1045                                         wsi->user_space, NULL, 0)) {
1046                                 lwsl_debug("raw rx callback closed it\n");
1047                                 goto close_and_handled;
1048                         }
1049                 }
1050
1051                 if (pollfd->revents & LWS_POLLHUP)
1052                         goto close_and_handled;
1053                 n = 0;
1054                 goto handled;
1055
1056         case LWSCM_WS_SERVING:
1057         case LWSCM_WS_CLIENT:
1058         case LWSCM_HTTP2_SERVING:
1059         case LWSCM_HTTP_CLIENT_ACCEPTED:
1060
1061                 /* 1: something requested a callback when it was OK to write */
1062
1063                 if (wsi->state == LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION)
1064                         lwsl_notice("xxx\n");
1065
1066                 if ((pollfd->revents & LWS_POLLOUT) &&
1067                     ((wsi->state == LWSS_ESTABLISHED ||
1068                      wsi->state == LWSS_HTTP2_ESTABLISHED ||
1069                      wsi->state == LWSS_HTTP2_ESTABLISHED_PRE_SETTINGS ||
1070                      wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
1071                      wsi->state == LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION ||
1072                      wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE)) &&
1073                     lws_handle_POLLOUT_event(wsi, pollfd)) {
1074                         if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY)
1075                                 wsi->state = LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE;
1076                         lwsl_info("lws_service_fd: closing\n");
1077                         goto close_and_handled;
1078                 }
1079
1080                 if (wsi->state == LWSS_RETURNED_CLOSE_ALREADY ||
1081                     wsi->state == LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION ||
1082                     wsi->state == LWSS_AWAITING_CLOSE_ACK) {
1083                         /*
1084                          * we stopped caring about anything except control
1085                          * packets.  Force flow control off, defeat tx
1086                          * draining.
1087                          */
1088                         lws_rx_flow_control(wsi, 1);
1089                         wsi->u.ws.tx_draining_ext = 0;
1090                 }
1091
1092                 if (wsi->u.ws.tx_draining_ext)
1093                         /* we cannot deal with new RX until the TX ext
1094                          * path has been drained.  It's because new
1095                          * rx will, eg, crap on the wsi rx buf that
1096                          * may be needed to retain state.
1097                          *
1098                          * TX ext drain path MUST go through event loop
1099                          * to avoid blocking.
1100                          */
1101                         break;
1102
1103                 if (!(wsi->rxflow_change_to & LWS_RXFLOW_ALLOW))
1104                         /* We cannot deal with any kind of new RX
1105                          * because we are RX-flowcontrolled.
1106                          */
1107                         break;
1108
1109                 /* 2: RX Extension needs to be drained
1110                  */
1111
1112                 if (wsi->state == LWSS_ESTABLISHED &&
1113                     wsi->u.ws.rx_draining_ext) {
1114
1115                         lwsl_ext("%s: RX EXT DRAINING: Service\n", __func__);
1116 #ifndef LWS_NO_CLIENT
1117                         if (wsi->mode == LWSCM_WS_CLIENT) {
1118                                 n = lws_client_rx_sm(wsi, 0);
1119                                 if (n < 0)
1120                                         /* we closed wsi */
1121                                         n = 0;
1122                         } else
1123 #endif
1124                                 n = lws_rx_sm(wsi, 0);
1125
1126                         goto handled;
1127                 }
1128
1129                 if (wsi->u.ws.rx_draining_ext)
1130                         /*
1131                          * We have RX EXT content to drain, but can't do it
1132                          * right now.  That means we cannot do anything lower
1133                          * priority either.
1134                          */
1135                         break;
1136
1137                 /* 3: RX Flowcontrol buffer needs to be drained
1138                  */
1139
1140                 if (wsi->rxflow_buffer) {
1141                         lwsl_info("draining rxflow (len %d)\n",
1142                                 wsi->rxflow_len - wsi->rxflow_pos
1143                         );
1144                         /* well, drain it */
1145                         eff_buf.token = (char *)wsi->rxflow_buffer +
1146                                                 wsi->rxflow_pos;
1147                         eff_buf.token_len = wsi->rxflow_len - wsi->rxflow_pos;
1148                         draining_flow = 1;
1149                         goto drain;
1150                 }
1151
1152                 /* 4: any incoming (or ah-stashed incoming rx) data ready?
1153                  * notice if rx flow going off raced poll(), rx flow wins
1154                  */
1155
1156                 if (!(pollfd->revents & pollfd->events & LWS_POLLIN))
1157                         break;
1158
1159 read:
1160                 /* all the union members start with hdr, so even in ws mode
1161                  * we can deal with the ah via u.hdr
1162                  */
1163                 if (wsi->u.hdr.ah) {
1164                         lwsl_info("%s: %p: inherited ah rx\n", __func__, wsi);
1165                         eff_buf.token_len = wsi->u.hdr.ah->rxlen -
1166                                             wsi->u.hdr.ah->rxpos;
1167                         eff_buf.token = (char *)wsi->u.hdr.ah->rx +
1168                                         wsi->u.hdr.ah->rxpos;
1169                 } else {
1170                         if (wsi->mode != LWSCM_HTTP_CLIENT_ACCEPTED) {
1171                                 /*
1172                                  * extension may not consume everything (eg, pmd may be constrained
1173                                  * as to what it can output...) has to go in per-wsi rx buf area.
1174                                  * Otherwise in large temp serv_buf area.
1175                                  */
1176                                 eff_buf.token = (char *)pt->serv_buf;
1177                                 if (lws_is_ws_with_ext(wsi)) {
1178                                         eff_buf.token_len = wsi->u.ws.rx_ubuf_alloc;
1179                                 } else {
1180                                         eff_buf.token_len = context->pt_serv_buf_size;
1181                                 }
1182
1183                                 if ((unsigned int)eff_buf.token_len > context->pt_serv_buf_size)
1184                                         eff_buf.token_len = context->pt_serv_buf_size;
1185
1186                                 eff_buf.token_len = lws_ssl_capable_read(wsi,
1187                                         (unsigned char *)eff_buf.token, pending ? pending :
1188                                         eff_buf.token_len);
1189                                 switch (eff_buf.token_len) {
1190                                 case 0:
1191                                         lwsl_info("%s: zero length read\n", __func__);
1192                                         goto close_and_handled;
1193                                 case LWS_SSL_CAPABLE_MORE_SERVICE:
1194                                         lwsl_info("SSL Capable more service\n");
1195                                         n = 0;
1196                                         goto handled;
1197                                 case LWS_SSL_CAPABLE_ERROR:
1198                                         lwsl_info("Closing when error\n");
1199                                         goto close_and_handled;
1200                                 }
1201                                 // lwsl_notice("Actual RX %d\n", eff_buf.token_len);
1202                         }
1203                 }
1204
1205 drain:
1206 #ifndef LWS_NO_CLIENT
1207                 if (wsi->mode == LWSCM_HTTP_CLIENT_ACCEPTED &&
1208                     !wsi->told_user_closed) {
1209
1210                         /*
1211                          * In SSL mode we get POLLIN notification about
1212                          * encrypted data in.
1213                          *
1214                          * But that is not necessarily related to decrypted
1215                          * data out becoming available; in may need to perform
1216                          * other in or out before that happens.
1217                          *
1218                          * simply mark ourselves as having readable data
1219                          * and turn off our POLLIN
1220                          */
1221                         wsi->client_rx_avail = 1;
1222                         lws_change_pollfd(wsi, LWS_POLLIN, 0);
1223
1224                         /* let user code know, he'll usually ask for writeable
1225                          * callback and drain / re-enable it there
1226                          */
1227                         if (user_callback_handle_rxflow(
1228                                         wsi->protocol->callback,
1229                                         wsi, LWS_CALLBACK_RECEIVE_CLIENT_HTTP,
1230                                         wsi->user_space, NULL, 0)) {
1231                                 lwsl_notice("LWS_CALLBACK_RECEIVE_CLIENT_HTTP closed it\n");
1232                                 goto close_and_handled;
1233                         }
1234
1235                         n = 0;
1236                         goto handled;
1237                 }
1238 #endif
1239                 /*
1240                  * give any active extensions a chance to munge the buffer
1241                  * before parse.  We pass in a pointer to an lws_tokens struct
1242                  * prepared with the default buffer and content length that's in
1243                  * there.  Rather than rewrite the default buffer, extensions
1244                  * that expect to grow the buffer can adapt .token to
1245                  * point to their own per-connection buffer in the extension
1246                  * user allocation.  By default with no extensions or no
1247                  * extension callback handling, just the normal input buffer is
1248                  * used then so it is efficient.
1249                  */
1250                 do {
1251                         more = 0;
1252
1253                         m = lws_ext_cb_active(wsi, LWS_EXT_CB_PACKET_RX_PREPARSE,
1254                                               &eff_buf, 0);
1255                         if (m < 0)
1256                                 goto close_and_handled;
1257                         if (m)
1258                                 more = 1;
1259
1260                         /* service incoming data */
1261
1262                         if (eff_buf.token_len) {
1263                                 /*
1264                                  * if draining from rxflow buffer, not
1265                                  * critical to track what was used since at the
1266                                  * use it bumps wsi->rxflow_pos.  If we come
1267                                  * around again it will pick up from where it
1268                                  * left off.
1269                                  */
1270                                 // lwsl_notice("doing lws_read from pt->serv_buf %p %p for len %d\n", pt->serv_buf, eff_buf.token, (int)eff_buf.token_len);
1271
1272                                 n = lws_read(wsi, (unsigned char *)eff_buf.token,
1273                                              eff_buf.token_len);
1274                                 if (n < 0) {
1275                                         /* we closed wsi */
1276                                         n = 0;
1277                                         goto handled;
1278                                 }
1279                         }
1280
1281                         eff_buf.token = NULL;
1282                         eff_buf.token_len = 0;
1283                 } while (more);
1284
1285                 if (wsi->u.hdr.ah) {
1286                         lwsl_notice("%s: %p: detaching\n",
1287                                  __func__, wsi);
1288                         lws_header_table_force_to_detachable_state(wsi);
1289                         /* we can run the normal ah detach flow despite
1290                          * being in ws union mode, since all union members
1291                          * start with hdr */
1292                         lws_header_table_detach(wsi, 0);
1293                 }
1294
1295                 pending = lws_ssl_pending(wsi);
1296                 if (pending) {
1297                         if (lws_is_ws_with_ext(wsi))
1298                                 pending = pending > wsi->u.ws.rx_ubuf_alloc ?
1299                                         wsi->u.ws.rx_ubuf_alloc : pending;
1300                         else
1301                                 pending = pending > context->pt_serv_buf_size ?
1302                                         context->pt_serv_buf_size : pending;
1303                         goto read;
1304                 }
1305
1306                 if (draining_flow && wsi->rxflow_buffer &&
1307                     wsi->rxflow_pos == wsi->rxflow_len) {
1308                         lwsl_info("flow buffer: drained\n");
1309                         lws_free_set_NULL(wsi->rxflow_buffer);
1310                         /* having drained the rxflow buffer, can rearm POLLIN */
1311 #ifdef LWS_NO_SERVER
1312                         n =
1313 #endif
1314                         _lws_rx_flow_control(wsi);
1315                         /* n ignored, needed for NO_SERVER case */
1316                 }
1317
1318                 break;
1319 #ifdef LWS_WITH_CGI
1320         case LWSCM_CGI: /* we exist to handle a cgi's stdin/out/err data...
1321                          * do the callback on our master wsi
1322                          */
1323                 {
1324                         struct lws_cgi_args args;
1325
1326                         if (wsi->cgi_channel >= LWS_STDOUT &&
1327                             !(pollfd->revents & pollfd->events & LWS_POLLIN))
1328                                 break;
1329                         if (wsi->cgi_channel == LWS_STDIN &&
1330                             !(pollfd->revents & pollfd->events & LWS_POLLOUT))
1331                                 break;
1332
1333                         if (wsi->cgi_channel == LWS_STDIN)
1334                                 if (lws_change_pollfd(wsi, LWS_POLLOUT, 0)) {
1335                                         lwsl_info("failed at set pollfd\n");
1336                                         return 1;
1337                                 }
1338
1339                         args.ch = wsi->cgi_channel;
1340                         args.stdwsi = &wsi->parent->cgi->stdwsi[0];
1341                         args.hdr_state = wsi->hdr_state;
1342
1343                         //lwsl_err("CGI LWS_STDOUT waiting wsi %p mode %d state %d\n",
1344                         //       wsi->parent, wsi->parent->mode, wsi->parent->state);
1345
1346                         if (user_callback_handle_rxflow(
1347                                         wsi->parent->protocol->callback,
1348                                         wsi->parent, LWS_CALLBACK_CGI,
1349                                         wsi->parent->user_space,
1350                                         (void *)&args, 0))
1351                                 return 1;
1352
1353                         break;
1354                 }
1355 #endif
1356         default:
1357 #ifdef LWS_NO_CLIENT
1358                 break;
1359 #else
1360                 if ((pollfd->revents & LWS_POLLOUT) &&
1361                     lws_handle_POLLOUT_event(wsi, pollfd)) {
1362                         lwsl_debug("POLLOUT event closed it\n");
1363                         goto close_and_handled;
1364                 }
1365
1366                 n = lws_client_socket_service(context, wsi, pollfd);
1367                 if (n)
1368                         return 1;
1369                 goto handled;
1370 #endif
1371         }
1372
1373         n = 0;
1374         goto handled;
1375
1376 close_and_handled:
1377         lwsl_debug("%p: Close and handled\n", wsi);
1378         lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
1379         /*
1380          * pollfd may point to something else after the close
1381          * due to pollfd swapping scheme on delete on some platforms
1382          * we can't clear revents now because it'd be the wrong guy's revents
1383          */
1384         return 1;
1385
1386 handled:
1387         pollfd->revents = 0;
1388         return n;
1389 }
1390
1391 LWS_VISIBLE int
1392 lws_service_fd(struct lws_context *context, struct lws_pollfd *pollfd)
1393 {
1394         return lws_service_fd_tsi(context, pollfd, 0);
1395 }
1396
1397 LWS_VISIBLE int
1398 lws_service(struct lws_context *context, int timeout_ms)
1399 {
1400         return lws_plat_service(context, timeout_ms);
1401 }
1402
1403 LWS_VISIBLE int
1404 lws_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
1405 {
1406         return _lws_plat_service_tsi(context, timeout_ms, tsi);
1407 }
1408