xref: /freebsd/contrib/libevent/listener.c (revision d37eb51047221dc3322b34db1038ff3aa533883f)
1 /*
2  * Copyright (c) 2009-2012 Niels Provos, Nick Mathewson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "event2/event-config.h"
28 #include "evconfig-private.h"
29 
30 #include <sys/types.h>
31 
32 #ifdef _WIN32
33 #ifndef _WIN32_WINNT
34 /* Minimum required for InitializeCriticalSectionAndSpinCount */
35 #define _WIN32_WINNT 0x0403
36 #endif
37 #include <winsock2.h>
38 #include <winerror.h>
39 #include <ws2tcpip.h>
40 #include <mswsock.h>
41 #endif
42 #include <errno.h>
43 #ifdef EVENT__HAVE_SYS_SOCKET_H
44 #include <sys/socket.h>
45 #endif
46 #ifdef EVENT__HAVE_FCNTL_H
47 #include <fcntl.h>
48 #endif
49 #ifdef EVENT__HAVE_UNISTD_H
50 #include <unistd.h>
51 #endif
52 
53 #include "event2/listener.h"
54 #include "event2/util.h"
55 #include "event2/event.h"
56 #include "event2/event_struct.h"
57 #include "mm-internal.h"
58 #include "util-internal.h"
59 #include "log-internal.h"
60 #include "evthread-internal.h"
61 #ifdef _WIN32
62 #include "iocp-internal.h"
63 #include "defer-internal.h"
64 #include "event-internal.h"
65 #endif
66 
67 struct evconnlistener_ops {
68 	int (*enable)(struct evconnlistener *);
69 	int (*disable)(struct evconnlistener *);
70 	void (*destroy)(struct evconnlistener *);
71 	void (*shutdown)(struct evconnlistener *);
72 	evutil_socket_t (*getfd)(struct evconnlistener *);
73 	struct event_base *(*getbase)(struct evconnlistener *);
74 };
75 
76 struct evconnlistener {
77 	const struct evconnlistener_ops *ops;
78 	void *lock;
79 	evconnlistener_cb cb;
80 	evconnlistener_errorcb errorcb;
81 	void *user_data;
82 	unsigned flags;
83 	short refcnt;
84 	int accept4_flags;
85 	unsigned enabled : 1;
86 };
87 
88 struct evconnlistener_event {
89 	struct evconnlistener base;
90 	struct event listener;
91 };
92 
93 #ifdef _WIN32
94 struct evconnlistener_iocp {
95 	struct evconnlistener base;
96 	evutil_socket_t fd;
97 	struct event_base *event_base;
98 	struct event_iocp_port *port;
99 	short n_accepting;
100 	unsigned shutting_down : 1;
101 	unsigned event_added : 1;
102 	struct accepting_socket **accepting;
103 };
104 #endif
105 
106 #define LOCK(listener) EVLOCK_LOCK((listener)->lock, 0)
107 #define UNLOCK(listener) EVLOCK_UNLOCK((listener)->lock, 0)
108 
109 struct evconnlistener *
110 evconnlistener_new_async(struct event_base *base,
111     evconnlistener_cb cb, void *ptr, unsigned flags, int backlog,
112     evutil_socket_t fd); /* XXXX export this? */
113 
114 static int event_listener_enable(struct evconnlistener *);
115 static int event_listener_disable(struct evconnlistener *);
116 static void event_listener_destroy(struct evconnlistener *);
117 static evutil_socket_t event_listener_getfd(struct evconnlistener *);
118 static struct event_base *event_listener_getbase(struct evconnlistener *);
119 
120 #if 0
121 static void
122 listener_incref_and_lock(struct evconnlistener *listener)
123 {
124 	LOCK(listener);
125 	++listener->refcnt;
126 }
127 #endif
128 
129 static int
130 listener_decref_and_unlock(struct evconnlistener *listener)
131 {
132 	int refcnt = --listener->refcnt;
133 	if (refcnt == 0) {
134 		listener->ops->destroy(listener);
135 		UNLOCK(listener);
136 		EVTHREAD_FREE_LOCK(listener->lock, EVTHREAD_LOCKTYPE_RECURSIVE);
137 		mm_free(listener);
138 		return 1;
139 	} else {
140 		UNLOCK(listener);
141 		return 0;
142 	}
143 }
144 
145 static const struct evconnlistener_ops evconnlistener_event_ops = {
146 	event_listener_enable,
147 	event_listener_disable,
148 	event_listener_destroy,
149 	NULL, /* shutdown */
150 	event_listener_getfd,
151 	event_listener_getbase
152 };
153 
154 static void listener_read_cb(evutil_socket_t, short, void *);
155 
156 struct evconnlistener *
157 evconnlistener_new(struct event_base *base,
158     evconnlistener_cb cb, void *ptr, unsigned flags, int backlog,
159     evutil_socket_t fd)
160 {
161 	struct evconnlistener_event *lev;
162 
163 #ifdef _WIN32
164 	if (base && event_base_get_iocp_(base)) {
165 		const struct win32_extension_fns *ext =
166 			event_get_win32_extension_fns_();
167 		if (ext->AcceptEx && ext->GetAcceptExSockaddrs)
168 			return evconnlistener_new_async(base, cb, ptr, flags,
169 				backlog, fd);
170 	}
171 #endif
172 
173 	if (backlog > 0) {
174 		if (listen(fd, backlog) < 0)
175 			return NULL;
176 	} else if (backlog < 0) {
177 		if (listen(fd, 128) < 0)
178 			return NULL;
179 	}
180 
181 	lev = mm_calloc(1, sizeof(struct evconnlistener_event));
182 	if (!lev)
183 		return NULL;
184 
185 	lev->base.ops = &evconnlistener_event_ops;
186 	lev->base.cb = cb;
187 	lev->base.user_data = ptr;
188 	lev->base.flags = flags;
189 	lev->base.refcnt = 1;
190 
191 	lev->base.accept4_flags = 0;
192 	if (!(flags & LEV_OPT_LEAVE_SOCKETS_BLOCKING))
193 		lev->base.accept4_flags |= EVUTIL_SOCK_NONBLOCK;
194 	if (flags & LEV_OPT_CLOSE_ON_EXEC)
195 		lev->base.accept4_flags |= EVUTIL_SOCK_CLOEXEC;
196 
197 	if (flags & LEV_OPT_THREADSAFE) {
198 		EVTHREAD_ALLOC_LOCK(lev->base.lock, EVTHREAD_LOCKTYPE_RECURSIVE);
199 	}
200 
201 	event_assign(&lev->listener, base, fd, EV_READ|EV_PERSIST,
202 	    listener_read_cb, lev);
203 
204 	if (!(flags & LEV_OPT_DISABLED))
205 	    evconnlistener_enable(&lev->base);
206 
207 	return &lev->base;
208 }
209 
210 struct evconnlistener *
211 evconnlistener_new_bind(struct event_base *base, evconnlistener_cb cb,
212     void *ptr, unsigned flags, int backlog, const struct sockaddr *sa,
213     int socklen)
214 {
215 	struct evconnlistener *listener;
216 	evutil_socket_t fd;
217 	int on = 1;
218 	int family = sa ? sa->sa_family : AF_UNSPEC;
219 	int socktype = SOCK_STREAM | EVUTIL_SOCK_NONBLOCK;
220 
221 	if (backlog == 0)
222 		return NULL;
223 
224 	if (flags & LEV_OPT_CLOSE_ON_EXEC)
225 		socktype |= EVUTIL_SOCK_CLOEXEC;
226 
227 	fd = evutil_socket_(family, socktype, 0);
228 	if (fd == -1)
229 		return NULL;
230 
231 	if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void*)&on, sizeof(on))<0)
232 		goto err;
233 
234 	if (flags & LEV_OPT_REUSEABLE) {
235 		if (evutil_make_listen_socket_reuseable(fd) < 0)
236 			goto err;
237 	}
238 
239 	if (flags & LEV_OPT_REUSEABLE_PORT) {
240 		if (evutil_make_listen_socket_reuseable_port(fd) < 0)
241 			goto err;
242 	}
243 
244 	if (flags & LEV_OPT_DEFERRED_ACCEPT) {
245 		if (evutil_make_tcp_listen_socket_deferred(fd) < 0)
246 			goto err;
247 	}
248 
249 	if (flags & LEV_OPT_BIND_IPV6ONLY) {
250 		if (evutil_make_listen_socket_ipv6only(fd) < 0)
251 			goto err;
252 	}
253 
254 	if (sa) {
255 		if (bind(fd, sa, socklen)<0)
256 			goto err;
257 	}
258 
259 	listener = evconnlistener_new(base, cb, ptr, flags, backlog, fd);
260 	if (!listener)
261 		goto err;
262 
263 	return listener;
264 err:
265 	evutil_closesocket(fd);
266 	return NULL;
267 }
268 
269 void
270 evconnlistener_free(struct evconnlistener *lev)
271 {
272 	LOCK(lev);
273 	lev->cb = NULL;
274 	lev->errorcb = NULL;
275 	if (lev->ops->shutdown)
276 		lev->ops->shutdown(lev);
277 	listener_decref_and_unlock(lev);
278 }
279 
280 static void
281 event_listener_destroy(struct evconnlistener *lev)
282 {
283 	struct evconnlistener_event *lev_e =
284 	    EVUTIL_UPCAST(lev, struct evconnlistener_event, base);
285 
286 	event_del(&lev_e->listener);
287 	if (lev->flags & LEV_OPT_CLOSE_ON_FREE)
288 		evutil_closesocket(event_get_fd(&lev_e->listener));
289 	event_debug_unassign(&lev_e->listener);
290 }
291 
292 int
293 evconnlistener_enable(struct evconnlistener *lev)
294 {
295 	int r;
296 	LOCK(lev);
297 	lev->enabled = 1;
298 	if (lev->cb)
299 		r = lev->ops->enable(lev);
300 	else
301 		r = 0;
302 	UNLOCK(lev);
303 	return r;
304 }
305 
306 int
307 evconnlistener_disable(struct evconnlistener *lev)
308 {
309 	int r;
310 	LOCK(lev);
311 	lev->enabled = 0;
312 	r = lev->ops->disable(lev);
313 	UNLOCK(lev);
314 	return r;
315 }
316 
317 static int
318 event_listener_enable(struct evconnlistener *lev)
319 {
320 	struct evconnlistener_event *lev_e =
321 	    EVUTIL_UPCAST(lev, struct evconnlistener_event, base);
322 	return event_add(&lev_e->listener, NULL);
323 }
324 
325 static int
326 event_listener_disable(struct evconnlistener *lev)
327 {
328 	struct evconnlistener_event *lev_e =
329 	    EVUTIL_UPCAST(lev, struct evconnlistener_event, base);
330 	return event_del(&lev_e->listener);
331 }
332 
333 evutil_socket_t
334 evconnlistener_get_fd(struct evconnlistener *lev)
335 {
336 	evutil_socket_t fd;
337 	LOCK(lev);
338 	fd = lev->ops->getfd(lev);
339 	UNLOCK(lev);
340 	return fd;
341 }
342 
343 static evutil_socket_t
344 event_listener_getfd(struct evconnlistener *lev)
345 {
346 	struct evconnlistener_event *lev_e =
347 	    EVUTIL_UPCAST(lev, struct evconnlistener_event, base);
348 	return event_get_fd(&lev_e->listener);
349 }
350 
351 struct event_base *
352 evconnlistener_get_base(struct evconnlistener *lev)
353 {
354 	struct event_base *base;
355 	LOCK(lev);
356 	base = lev->ops->getbase(lev);
357 	UNLOCK(lev);
358 	return base;
359 }
360 
361 static struct event_base *
362 event_listener_getbase(struct evconnlistener *lev)
363 {
364 	struct evconnlistener_event *lev_e =
365 	    EVUTIL_UPCAST(lev, struct evconnlistener_event, base);
366 	return event_get_base(&lev_e->listener);
367 }
368 
369 void
370 evconnlistener_set_cb(struct evconnlistener *lev,
371     evconnlistener_cb cb, void *arg)
372 {
373 	int enable = 0;
374 	LOCK(lev);
375 	if (lev->enabled && !lev->cb)
376 		enable = 1;
377 	lev->cb = cb;
378 	lev->user_data = arg;
379 	if (enable)
380 		evconnlistener_enable(lev);
381 	UNLOCK(lev);
382 }
383 
384 void
385 evconnlistener_set_error_cb(struct evconnlistener *lev,
386     evconnlistener_errorcb errorcb)
387 {
388 	LOCK(lev);
389 	lev->errorcb = errorcb;
390 	UNLOCK(lev);
391 }
392 
393 static void
394 listener_read_cb(evutil_socket_t fd, short what, void *p)
395 {
396 	struct evconnlistener *lev = p;
397 	int err;
398 	evconnlistener_cb cb;
399 	evconnlistener_errorcb errorcb;
400 	void *user_data;
401 	LOCK(lev);
402 	while (1) {
403 		struct sockaddr_storage ss;
404 		ev_socklen_t socklen = sizeof(ss);
405 		evutil_socket_t new_fd = evutil_accept4_(fd, (struct sockaddr*)&ss, &socklen, lev->accept4_flags);
406 		if (new_fd < 0)
407 			break;
408 		if (socklen == 0) {
409 			/* This can happen with some older linux kernels in
410 			 * response to nmap. */
411 			evutil_closesocket(new_fd);
412 			continue;
413 		}
414 
415 		if (lev->cb == NULL) {
416 			evutil_closesocket(new_fd);
417 			UNLOCK(lev);
418 			return;
419 		}
420 		++lev->refcnt;
421 		cb = lev->cb;
422 		user_data = lev->user_data;
423 		UNLOCK(lev);
424 		cb(lev, new_fd, (struct sockaddr*)&ss, (int)socklen,
425 		    user_data);
426 		LOCK(lev);
427 		if (lev->refcnt == 1) {
428 			int freed = listener_decref_and_unlock(lev);
429 			EVUTIL_ASSERT(freed);
430 			return;
431 		}
432 		--lev->refcnt;
433 		if (!lev->enabled) {
434 			/* the callback could have disabled the listener */
435 			UNLOCK(lev);
436 			return;
437 		}
438 	}
439 	err = evutil_socket_geterror(fd);
440 	if (EVUTIL_ERR_ACCEPT_RETRIABLE(err)) {
441 		UNLOCK(lev);
442 		return;
443 	}
444 	if (lev->errorcb != NULL) {
445 		++lev->refcnt;
446 		errorcb = lev->errorcb;
447 		user_data = lev->user_data;
448 		UNLOCK(lev);
449 		errorcb(lev, user_data);
450 		LOCK(lev);
451 		listener_decref_and_unlock(lev);
452 	} else {
453 		event_sock_warn(fd, "Error from accept() call");
454 		UNLOCK(lev);
455 	}
456 }
457 
458 #ifdef _WIN32
459 struct accepting_socket {
460 	CRITICAL_SECTION lock;
461 	struct event_overlapped overlapped;
462 	SOCKET s;
463 	int error;
464 	struct event_callback deferred;
465 	struct evconnlistener_iocp *lev;
466 	ev_uint8_t buflen;
467 	ev_uint8_t family;
468 	unsigned free_on_cb:1;
469 	char addrbuf[1];
470 };
471 
472 static void accepted_socket_cb(struct event_overlapped *o, ev_uintptr_t key,
473     ev_ssize_t n, int ok);
474 static void accepted_socket_invoke_user_cb(struct event_callback *cb, void *arg);
475 
476 static void
477 iocp_listener_event_add(struct evconnlistener_iocp *lev)
478 {
479 	if (lev->event_added)
480 		return;
481 
482 	lev->event_added = 1;
483 	event_base_add_virtual_(lev->event_base);
484 }
485 
486 static void
487 iocp_listener_event_del(struct evconnlistener_iocp *lev)
488 {
489 	if (!lev->event_added)
490 		return;
491 
492 	lev->event_added = 0;
493 	event_base_del_virtual_(lev->event_base);
494 }
495 
496 static struct accepting_socket *
497 new_accepting_socket(struct evconnlistener_iocp *lev, int family)
498 {
499 	struct accepting_socket *res;
500 	int addrlen;
501 	int buflen;
502 
503 	if (family == AF_INET)
504 		addrlen = sizeof(struct sockaddr_in);
505 	else if (family == AF_INET6)
506 		addrlen = sizeof(struct sockaddr_in6);
507 	else
508 		return NULL;
509 	buflen = (addrlen+16)*2;
510 
511 	res = mm_calloc(1,sizeof(struct accepting_socket)-1+buflen);
512 	if (!res)
513 		return NULL;
514 
515 	event_overlapped_init_(&res->overlapped, accepted_socket_cb);
516 	res->s = EVUTIL_INVALID_SOCKET;
517 	res->lev = lev;
518 	res->buflen = buflen;
519 	res->family = family;
520 
521 	event_deferred_cb_init_(&res->deferred,
522 	    event_base_get_npriorities(lev->event_base) / 2,
523 	    accepted_socket_invoke_user_cb, res);
524 
525 	InitializeCriticalSectionAndSpinCount(&res->lock, 1000);
526 
527 	return res;
528 }
529 
530 static void
531 free_and_unlock_accepting_socket(struct accepting_socket *as)
532 {
533 	/* requires lock. */
534 	if (as->s != EVUTIL_INVALID_SOCKET)
535 		closesocket(as->s);
536 
537 	LeaveCriticalSection(&as->lock);
538 	DeleteCriticalSection(&as->lock);
539 	mm_free(as);
540 }
541 
542 static int
543 start_accepting(struct accepting_socket *as)
544 {
545 	/* requires lock */
546 	const struct win32_extension_fns *ext = event_get_win32_extension_fns_();
547 	DWORD pending = 0;
548 	SOCKET s = socket(as->family, SOCK_STREAM, 0);
549 	int error = 0;
550 
551 	if (!as->lev->base.enabled)
552 		return 0;
553 
554 	if (s == EVUTIL_INVALID_SOCKET) {
555 		error = WSAGetLastError();
556 		goto report_err;
557 	}
558 
559 	/* XXXX It turns out we need to do this again later.  Does this call
560 	 * have any effect? */
561 	setsockopt(s, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT,
562 	    (char *)&as->lev->fd, sizeof(&as->lev->fd));
563 
564 	if (!(as->lev->base.flags & LEV_OPT_LEAVE_SOCKETS_BLOCKING))
565 		evutil_make_socket_nonblocking(s);
566 
567 	if (event_iocp_port_associate_(as->lev->port, s, 1) < 0) {
568 		closesocket(s);
569 		return -1;
570 	}
571 
572 	as->s = s;
573 
574 	if (ext->AcceptEx(as->lev->fd, s, as->addrbuf, 0,
575 		as->buflen/2, as->buflen/2, &pending, &as->overlapped.overlapped))
576 	{
577 		/* Immediate success! */
578 		accepted_socket_cb(&as->overlapped, 1, 0, 1);
579 	} else {
580 		error = WSAGetLastError();
581 		if (error != ERROR_IO_PENDING) {
582 			goto report_err;
583 		}
584 	}
585 
586 	return 0;
587 
588 report_err:
589 	as->error = error;
590 	event_deferred_cb_schedule_(
591 		as->lev->event_base,
592 		&as->deferred);
593 	return 0;
594 }
595 
596 static void
597 stop_accepting(struct accepting_socket *as)
598 {
599 	/* requires lock. */
600 	SOCKET s = as->s;
601 	as->s = EVUTIL_INVALID_SOCKET;
602 	closesocket(s);
603 }
604 
605 static void
606 accepted_socket_invoke_user_cb(struct event_callback *dcb, void *arg)
607 {
608 	struct accepting_socket *as = arg;
609 
610 	struct sockaddr *sa_local=NULL, *sa_remote=NULL;
611 	int socklen_local=0, socklen_remote=0;
612 	const struct win32_extension_fns *ext = event_get_win32_extension_fns_();
613 	struct evconnlistener *lev = &as->lev->base;
614 	evutil_socket_t sock=-1;
615 	void *data;
616 	evconnlistener_cb cb=NULL;
617 	evconnlistener_errorcb errorcb=NULL;
618 	int error;
619 
620 	EVUTIL_ASSERT(ext->GetAcceptExSockaddrs);
621 
622 	LOCK(lev);
623 	EnterCriticalSection(&as->lock);
624 	if (as->free_on_cb) {
625 		free_and_unlock_accepting_socket(as);
626 		listener_decref_and_unlock(lev);
627 		return;
628 	}
629 
630 	++lev->refcnt;
631 
632 	error = as->error;
633 	if (error) {
634 		as->error = 0;
635 		errorcb = lev->errorcb;
636 	} else {
637 		ext->GetAcceptExSockaddrs(
638 			as->addrbuf, 0, as->buflen/2, as->buflen/2,
639 			&sa_local, &socklen_local, &sa_remote,
640 			&socklen_remote);
641 		sock = as->s;
642 		cb = lev->cb;
643 		as->s = EVUTIL_INVALID_SOCKET;
644 
645 		/* We need to call this so getsockname, getpeername, and
646 		 * shutdown work correctly on the accepted socket. */
647 		/* XXXX handle error? */
648 		setsockopt(sock, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT,
649 		    (char *)&as->lev->fd, sizeof(&as->lev->fd));
650 	}
651 	data = lev->user_data;
652 
653 	LeaveCriticalSection(&as->lock);
654 	UNLOCK(lev);
655 
656 	if (errorcb) {
657 		WSASetLastError(error);
658 		errorcb(lev, data);
659 	} else if (cb) {
660 		cb(lev, sock, sa_remote, socklen_remote, data);
661 	}
662 
663 	LOCK(lev);
664 	if (listener_decref_and_unlock(lev))
665 		return;
666 
667 	EnterCriticalSection(&as->lock);
668 	start_accepting(as);
669 	LeaveCriticalSection(&as->lock);
670 }
671 
672 static void
673 accepted_socket_cb(struct event_overlapped *o, ev_uintptr_t key, ev_ssize_t n, int ok)
674 {
675 	struct accepting_socket *as =
676 	    EVUTIL_UPCAST(o, struct accepting_socket, overlapped);
677 
678 	LOCK(&as->lev->base);
679 	EnterCriticalSection(&as->lock);
680 	if (ok) {
681 		/* XXXX Don't do this if some EV_MT flag is set. */
682 		event_deferred_cb_schedule_(
683 			as->lev->event_base,
684 			&as->deferred);
685 		LeaveCriticalSection(&as->lock);
686 	} else if (as->free_on_cb) {
687 		struct evconnlistener *lev = &as->lev->base;
688 		free_and_unlock_accepting_socket(as);
689 		listener_decref_and_unlock(lev);
690 		return;
691 	} else if (as->s == EVUTIL_INVALID_SOCKET) {
692 		/* This is okay; we were disabled by iocp_listener_disable. */
693 		LeaveCriticalSection(&as->lock);
694 	} else {
695 		/* Some error on accept that we couldn't actually handle. */
696 		BOOL ok;
697 		DWORD transfer = 0, flags=0;
698 		event_sock_warn(as->s, "Unexpected error on AcceptEx");
699 		ok = WSAGetOverlappedResult(as->s, &o->overlapped,
700 		    &transfer, FALSE, &flags);
701 		if (ok) {
702 			/* well, that was confusing! */
703 			as->error = 1;
704 		} else {
705 			as->error = WSAGetLastError();
706 		}
707 		event_deferred_cb_schedule_(
708 			as->lev->event_base,
709 			&as->deferred);
710 		LeaveCriticalSection(&as->lock);
711 	}
712 	UNLOCK(&as->lev->base);
713 }
714 
715 static int
716 iocp_listener_enable(struct evconnlistener *lev)
717 {
718 	int i;
719 	struct evconnlistener_iocp *lev_iocp =
720 	    EVUTIL_UPCAST(lev, struct evconnlistener_iocp, base);
721 
722 	LOCK(lev);
723 	iocp_listener_event_add(lev_iocp);
724 	for (i = 0; i < lev_iocp->n_accepting; ++i) {
725 		struct accepting_socket *as = lev_iocp->accepting[i];
726 		if (!as)
727 			continue;
728 		EnterCriticalSection(&as->lock);
729 		if (!as->free_on_cb && as->s == EVUTIL_INVALID_SOCKET)
730 			start_accepting(as);
731 		LeaveCriticalSection(&as->lock);
732 	}
733 	UNLOCK(lev);
734 	return 0;
735 }
736 
737 static int
738 iocp_listener_disable_impl(struct evconnlistener *lev, int shutdown)
739 {
740 	int i;
741 	struct evconnlistener_iocp *lev_iocp =
742 	    EVUTIL_UPCAST(lev, struct evconnlistener_iocp, base);
743 
744 	LOCK(lev);
745 	iocp_listener_event_del(lev_iocp);
746 	for (i = 0; i < lev_iocp->n_accepting; ++i) {
747 		struct accepting_socket *as = lev_iocp->accepting[i];
748 		if (!as)
749 			continue;
750 		EnterCriticalSection(&as->lock);
751 		if (!as->free_on_cb && as->s != EVUTIL_INVALID_SOCKET) {
752 			if (shutdown)
753 				as->free_on_cb = 1;
754 			stop_accepting(as);
755 		}
756 		LeaveCriticalSection(&as->lock);
757 	}
758 
759 	if (shutdown && lev->flags & LEV_OPT_CLOSE_ON_FREE)
760 		evutil_closesocket(lev_iocp->fd);
761 
762 	UNLOCK(lev);
763 	return 0;
764 }
765 
766 static int
767 iocp_listener_disable(struct evconnlistener *lev)
768 {
769 	return iocp_listener_disable_impl(lev,0);
770 }
771 
772 static void
773 iocp_listener_destroy(struct evconnlistener *lev)
774 {
775 	struct evconnlistener_iocp *lev_iocp =
776 	    EVUTIL_UPCAST(lev, struct evconnlistener_iocp, base);
777 
778 	if (! lev_iocp->shutting_down) {
779 		lev_iocp->shutting_down = 1;
780 		iocp_listener_disable_impl(lev,1);
781 	}
782 
783 }
784 
785 static evutil_socket_t
786 iocp_listener_getfd(struct evconnlistener *lev)
787 {
788 	struct evconnlistener_iocp *lev_iocp =
789 	    EVUTIL_UPCAST(lev, struct evconnlistener_iocp, base);
790 	return lev_iocp->fd;
791 }
792 static struct event_base *
793 iocp_listener_getbase(struct evconnlistener *lev)
794 {
795 	struct evconnlistener_iocp *lev_iocp =
796 	    EVUTIL_UPCAST(lev, struct evconnlistener_iocp, base);
797 	return lev_iocp->event_base;
798 }
799 
800 static const struct evconnlistener_ops evconnlistener_iocp_ops = {
801 	iocp_listener_enable,
802 	iocp_listener_disable,
803 	iocp_listener_destroy,
804 	iocp_listener_destroy, /* shutdown */
805 	iocp_listener_getfd,
806 	iocp_listener_getbase
807 };
808 
809 /* XXX define some way to override this. */
810 #define N_SOCKETS_PER_LISTENER 4
811 
812 struct evconnlistener *
813 evconnlistener_new_async(struct event_base *base,
814     evconnlistener_cb cb, void *ptr, unsigned flags, int backlog,
815     evutil_socket_t fd)
816 {
817 	struct sockaddr_storage ss;
818 	int socklen = sizeof(ss);
819 	struct evconnlistener_iocp *lev;
820 	int i;
821 
822 	flags |= LEV_OPT_THREADSAFE;
823 
824 	if (!base || !event_base_get_iocp_(base))
825 		goto err;
826 
827 	/* XXXX duplicate code */
828 	if (backlog > 0) {
829 		if (listen(fd, backlog) < 0)
830 			goto err;
831 	} else if (backlog < 0) {
832 		if (listen(fd, 128) < 0)
833 			goto err;
834 	}
835 	if (getsockname(fd, (struct sockaddr*)&ss, &socklen)) {
836 		event_sock_warn(fd, "getsockname");
837 		goto err;
838 	}
839 	lev = mm_calloc(1, sizeof(struct evconnlistener_iocp));
840 	if (!lev) {
841 		event_warn("calloc");
842 		goto err;
843 	}
844 	lev->base.ops = &evconnlistener_iocp_ops;
845 	lev->base.cb = cb;
846 	lev->base.user_data = ptr;
847 	lev->base.flags = flags;
848 	lev->base.refcnt = 1;
849 	lev->base.enabled = 1;
850 
851 	lev->port = event_base_get_iocp_(base);
852 	lev->fd = fd;
853 	lev->event_base = base;
854 
855 
856 	if (event_iocp_port_associate_(lev->port, fd, 1) < 0)
857 		goto err_free_lev;
858 
859 	EVTHREAD_ALLOC_LOCK(lev->base.lock, EVTHREAD_LOCKTYPE_RECURSIVE);
860 
861 	lev->n_accepting = N_SOCKETS_PER_LISTENER;
862 	lev->accepting = mm_calloc(lev->n_accepting,
863 	    sizeof(struct accepting_socket *));
864 	if (!lev->accepting) {
865 		event_warn("calloc");
866 		goto err_delete_lock;
867 	}
868 	for (i = 0; i < lev->n_accepting; ++i) {
869 		lev->accepting[i] = new_accepting_socket(lev, ss.ss_family);
870 		if (!lev->accepting[i]) {
871 			event_warnx("Couldn't create accepting socket");
872 			goto err_free_accepting;
873 		}
874 		if (cb && start_accepting(lev->accepting[i]) < 0) {
875 			event_warnx("Couldn't start accepting on socket");
876 			EnterCriticalSection(&lev->accepting[i]->lock);
877 			free_and_unlock_accepting_socket(lev->accepting[i]);
878 			goto err_free_accepting;
879 		}
880 		++lev->base.refcnt;
881 	}
882 
883 	iocp_listener_event_add(lev);
884 
885 	return &lev->base;
886 
887 err_free_accepting:
888 	mm_free(lev->accepting);
889 	/* XXXX free the other elements. */
890 err_delete_lock:
891 	EVTHREAD_FREE_LOCK(lev->base.lock, EVTHREAD_LOCKTYPE_RECURSIVE);
892 err_free_lev:
893 	mm_free(lev);
894 err:
895 	/* Don't close the fd, it is caller's responsibility. */
896 	return NULL;
897 }
898 
899 #endif
900