libwebsockets/lib/plat/windows/windows-service.c

/*
 * libwebsockets - small server side websockets and web server implementation
 *
 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef _WINSOCK_DEPRECATED_NO_WARNINGS
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#endif
#include "private-lib-core.h"


int
_lws_plat_service_forced_tsi(struct lws_context *context, int tsi)
{
	struct lws_context_per_thread *pt = &context->pt[tsi];
	int m, n, r;

	r = lws_service_flag_pending(context, tsi);

	/* any socket with events to service? */
	for (n = 0; n < (int)pt->fds_count; n++) {
		if (!pt->fds[n].revents)
			continue;

		m = lws_service_fd_tsi(context, &pt->fds[n], tsi);
		if (m < 0)
			return -1;
		/* if something closed, retry this slot */
		if (m)
			n--;
	}

	lws_service_do_ripe_rxflow(pt);

	return r;
}

extern void lws_client_conn_wait_timeout(lws_sorted_usec_list_t *sul);

int
_lws_plat_service_tsi(struct lws_context *context, int timeout_ms, int tsi)
{
	struct lws_context_per_thread *pt;
	WSANETWORKEVENTS networkevents;
	struct lws_pollfd *pfd;
	lws_usec_t timeout_us;
	struct lws *wsi;
	unsigned int i;
	DWORD ev;
	int n;
	unsigned int eIdx;
	int interrupt_requested;

	/* stay dead once we are dead */
	if (context == NULL || !context->vhost_list)
		return 1;

	pt = &context->pt[tsi];

	if (!pt->service_tid_detected) {
		struct lws _lws;

		memset(&_lws, 0, sizeof(_lws));
		_lws.context = context;

		pt->service_tid = context->vhost_list->
			protocols[0].callback(&_lws, LWS_CALLBACK_GET_THREAD_ID,
						  NULL, NULL, 0);
		pt->service_tid_detected = 1;
	}

	if (timeout_ms < 0)
		timeout_ms = 0;
	else
		/* force a default timeout of 23 days */
		timeout_ms = 2000000000;
	timeout_us = ((lws_usec_t)timeout_ms) * LWS_US_PER_MS;

	if (context->event_loop_ops->run_pt)
		context->event_loop_ops->run_pt(context, tsi);

	for (i = 0; i < pt->fds_count; ++i) {
		pfd = &pt->fds[i];

		if (!(pfd->events & LWS_POLLOUT))
			continue;

		wsi = wsi_from_fd(context, pfd->fd);
		if (!wsi || wsi->listener)
			continue;
		if (wsi->sock_send_blocking)
			continue;
		pfd->revents = LWS_POLLOUT;
		n = lws_service_fd(context, pfd);
		if (n < 0)
			return -1;

		/*
		 * Force WSAWaitForMultipleEvents() to check events
		 * and then return immediately.
		 */
		timeout_us = 0;

		/* if something closed, retry this slot */
		if (n)
			i--;
	}

	/*
	 * service pending callbacks and get maximum wait time
	 */
	{
		lws_usec_t us;

		lws_pt_lock(pt, __func__);
		/* don't stay in poll wait longer than next hr timeout */
		us = __lws_sul_service_ripe(pt->pt_sul_owner,
					    LWS_COUNT_PT_SUL_OWNERS,
					    lws_now_usecs());
		if (us && us < timeout_us)
			timeout_us = us;

		lws_pt_unlock(pt);
	}

	if (_lws_plat_service_forced_tsi(context, tsi))
		timeout_us = 0;

	/*
	 * is there anybody with pending stuff that needs service forcing?
	 */
	if (!lws_service_adjust_timeout(context, 1, tsi))
		timeout_us = 0;

	for (n = 0; n < (int)pt->fds_count; n++)
		WSAEventSelect(pt->fds[n].fd, pt->events,
		       FD_READ | (!!(pt->fds[n].events & LWS_POLLOUT) * FD_WRITE) |
		       FD_OOB | FD_ACCEPT |
		       FD_CONNECT | FD_CLOSE | FD_QOS |
		       FD_ROUTING_INTERFACE_CHANGE |
		       FD_ADDRESS_LIST_CHANGE);

	ev = WSAWaitForMultipleEvents(1, &pt->events, FALSE,
				      (DWORD)(timeout_us / LWS_US_PER_MS), FALSE);
	if (ev != WSA_WAIT_EVENT_0)
		return 0;

	EnterCriticalSection(&pt->interrupt_lock);
	interrupt_requested = pt->interrupt_requested;
	pt->interrupt_requested = 0;
	LeaveCriticalSection(&pt->interrupt_lock);
	if (interrupt_requested) {
		lws_broadcast(pt, LWS_CALLBACK_EVENT_WAIT_CANCELLED,
			      NULL, 0);
		return 0;
	}

#if defined(LWS_WITH_TLS)
	if (pt->context->tls_ops &&
	    pt->context->tls_ops->fake_POLLIN_for_buffered)
		pt->context->tls_ops->fake_POLLIN_for_buffered(pt);
#endif

	for (eIdx = 0; eIdx < pt->fds_count; ++eIdx) {
		unsigned int err;

		if (WSAEnumNetworkEvents(pt->fds[eIdx].fd, pt->events,
				&networkevents) == SOCKET_ERROR) {
			lwsl_err("WSAEnumNetworkEvents() failed "
				 "with error %d\n", LWS_ERRNO);
			return -1;
		}

		if (!networkevents.lNetworkEvents)
			networkevents.lNetworkEvents = LWS_POLLOUT;

		pfd = &pt->fds[eIdx];
		pfd->revents = (short)networkevents.lNetworkEvents;

		err = networkevents.iErrorCode[FD_CONNECT_BIT];
               if ((networkevents.lNetworkEvents & FD_CONNECT) && wsi_from_fd(context, pfd->fd) && !wsi_from_fd(context, pfd->fd)->udp) {
                       lwsl_debug("%s: FD_CONNECT: %p\n", __func__, wsi_from_fd(context, pfd->fd));
			pfd->revents &= ~LWS_POLLOUT;
			if (err && err != LWS_EALREADY &&
			    err != LWS_EINPROGRESS && err != LWS_EWOULDBLOCK &&
			    err != WSAEINVAL) {
				lwsl_debug("Unable to connect errno=%d\n", err);

				/*
				 * the connection has definitively failed... but
				 * do we have more DNS entries to try?
				 */
				if (wsi_from_fd(context, pfd->fd)->dns_results_next) {
					lws_sul_schedule(context, 0, &wsi_from_fd(context, pfd->fd)->
									sul_connect_timeout,
							 lws_client_conn_wait_timeout, 1);
					continue;
                               } else
					pfd->revents |= LWS_POLLHUP;
			} else
                               if (wsi_from_fd(context, pfd->fd)) {
                                       if (wsi_from_fd(context, pfd->fd)->udp)
                                               pfd->revents |= LWS_POLLHUP;
                                       else
                                               lws_client_connect_3_connect(wsi_from_fd(context, pfd->fd),
								NULL, NULL, LWS_CONNECT_COMPLETION_GOOD,
								NULL);
                               }
		}

		if (pfd->revents & LWS_POLLOUT) {
			wsi = wsi_from_fd(context, pfd->fd);
			if (wsi)
				wsi->sock_send_blocking = 0;
		}
		 /* if something closed, retry this slot */
		if (pfd->revents & LWS_POLLHUP)
			--eIdx;

		if (pfd->revents) {
			/*
			 * On windows is somehow necessary to "acknowledge" the
			 * POLLIN event, otherwise we never receive another one
			 * on the TCP connection.  But it breaks UDP, so only
			 * do it on non-UDP.
			 */
			if (!wsi_from_fd(context, pfd->fd)->udp)
				recv(pfd->fd, NULL, 0, 0);

			lws_service_fd_tsi(context, pfd, tsi);
		}
	}

	return 0;
}

int
lws_plat_service(struct lws_context *context, int timeout_ms)
{
	return _lws_plat_service_tsi(context, timeout_ms, 0);
}