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1 /*
2  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
3  *
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "event2/event-config.h"
30 #include "evconfig-private.h"
31 
32 #ifdef EVENT__HAVE_SYS_TIME_H
33 #include <sys/time.h>
34 #endif
35 
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #ifdef EVENT__HAVE_STDARG_H
41 #include <stdarg.h>
42 #endif
43 #ifdef EVENT__HAVE_UNISTD_H
44 #include <unistd.h>
45 #endif
46 
47 #ifdef _WIN32
48 #include <winsock2.h>
49 #include <winerror.h>
50 #include <ws2tcpip.h>
51 #endif
52 
53 #include <sys/queue.h>
54 
55 #include "event2/util.h"
56 #include "event2/bufferevent.h"
57 #include "event2/buffer.h"
58 #include "event2/bufferevent_struct.h"
59 #include "event2/event.h"
60 #include "event2/util.h"
61 #include "event-internal.h"
62 #include "log-internal.h"
63 #include "mm-internal.h"
64 #include "bufferevent-internal.h"
65 #include "util-internal.h"
66 #include "iocp-internal.h"
67 
68 #ifndef SO_UPDATE_CONNECT_CONTEXT
69 /* Mingw is sometimes missing this */
70 #define SO_UPDATE_CONNECT_CONTEXT 0x7010
71 #endif
72 
73 /* prototypes */
74 static int be_async_enable(struct bufferevent *, short);
75 static int be_async_disable(struct bufferevent *, short);
76 static void be_async_destruct(struct bufferevent *);
77 static int be_async_flush(struct bufferevent *, short, enum bufferevent_flush_mode);
78 static int be_async_ctrl(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *);
79 
80 struct bufferevent_async {
81 	struct bufferevent_private bev;
82 	struct event_overlapped connect_overlapped;
83 	struct event_overlapped read_overlapped;
84 	struct event_overlapped write_overlapped;
85 	size_t read_in_progress;
86 	size_t write_in_progress;
87 	unsigned ok : 1;
88 	unsigned read_added : 1;
89 	unsigned write_added : 1;
90 };
91 
92 const struct bufferevent_ops bufferevent_ops_async = {
93 	"socket_async",
94 	evutil_offsetof(struct bufferevent_async, bev.bev),
95 	be_async_enable,
96 	be_async_disable,
97 	NULL, /* Unlink */
98 	be_async_destruct,
99 	bufferevent_generic_adj_timeouts_,
100 	be_async_flush,
101 	be_async_ctrl,
102 };
103 
104 static inline void
be_async_run_eventcb(struct bufferevent * bev,short what,int options)105 be_async_run_eventcb(struct bufferevent *bev, short what, int options)
106 { bufferevent_run_eventcb_(bev, what, options|BEV_TRIG_DEFER_CALLBACKS); }
107 
108 static inline void
be_async_trigger_nolock(struct bufferevent * bev,short what,int options)109 be_async_trigger_nolock(struct bufferevent *bev, short what, int options)
110 { bufferevent_trigger_nolock_(bev, what, options|BEV_TRIG_DEFER_CALLBACKS); }
111 
112 static inline int
fatal_error(int err)113 fatal_error(int err)
114 {
115 	switch (err) {
116 		/* We may have already associated this fd with a port.
117 		 * Let's hope it's this port, and that the error code
118 		 * for doing this neer changes. */
119 		case ERROR_INVALID_PARAMETER:
120 			return 0;
121 	}
122 	return 1;
123 }
124 
125 static inline struct bufferevent_async *
upcast(struct bufferevent * bev)126 upcast(struct bufferevent *bev)
127 {
128 	struct bufferevent_async *bev_a;
129 	if (!BEV_IS_ASYNC(bev))
130 		return NULL;
131 	bev_a = EVUTIL_UPCAST(bev, struct bufferevent_async, bev.bev);
132 	return bev_a;
133 }
134 
135 static inline struct bufferevent_async *
upcast_connect(struct event_overlapped * eo)136 upcast_connect(struct event_overlapped *eo)
137 {
138 	struct bufferevent_async *bev_a;
139 	bev_a = EVUTIL_UPCAST(eo, struct bufferevent_async, connect_overlapped);
140 	EVUTIL_ASSERT(BEV_IS_ASYNC(&bev_a->bev.bev));
141 	return bev_a;
142 }
143 
144 static inline struct bufferevent_async *
upcast_read(struct event_overlapped * eo)145 upcast_read(struct event_overlapped *eo)
146 {
147 	struct bufferevent_async *bev_a;
148 	bev_a = EVUTIL_UPCAST(eo, struct bufferevent_async, read_overlapped);
149 	EVUTIL_ASSERT(BEV_IS_ASYNC(&bev_a->bev.bev));
150 	return bev_a;
151 }
152 
153 static inline struct bufferevent_async *
upcast_write(struct event_overlapped * eo)154 upcast_write(struct event_overlapped *eo)
155 {
156 	struct bufferevent_async *bev_a;
157 	bev_a = EVUTIL_UPCAST(eo, struct bufferevent_async, write_overlapped);
158 	EVUTIL_ASSERT(BEV_IS_ASYNC(&bev_a->bev.bev));
159 	return bev_a;
160 }
161 
162 static void
bev_async_del_write(struct bufferevent_async * beva)163 bev_async_del_write(struct bufferevent_async *beva)
164 {
165 	struct bufferevent *bev = &beva->bev.bev;
166 
167 	if (beva->write_added) {
168 		beva->write_added = 0;
169 		event_base_del_virtual_(bev->ev_base);
170 	}
171 }
172 
173 static void
bev_async_del_read(struct bufferevent_async * beva)174 bev_async_del_read(struct bufferevent_async *beva)
175 {
176 	struct bufferevent *bev = &beva->bev.bev;
177 
178 	if (beva->read_added) {
179 		beva->read_added = 0;
180 		event_base_del_virtual_(bev->ev_base);
181 	}
182 }
183 
184 static void
bev_async_add_write(struct bufferevent_async * beva)185 bev_async_add_write(struct bufferevent_async *beva)
186 {
187 	struct bufferevent *bev = &beva->bev.bev;
188 
189 	if (!beva->write_added) {
190 		beva->write_added = 1;
191 		event_base_add_virtual_(bev->ev_base);
192 	}
193 }
194 
195 static void
bev_async_add_read(struct bufferevent_async * beva)196 bev_async_add_read(struct bufferevent_async *beva)
197 {
198 	struct bufferevent *bev = &beva->bev.bev;
199 
200 	if (!beva->read_added) {
201 		beva->read_added = 1;
202 		event_base_add_virtual_(bev->ev_base);
203 	}
204 }
205 
206 static void
bev_async_consider_writing(struct bufferevent_async * beva)207 bev_async_consider_writing(struct bufferevent_async *beva)
208 {
209 	size_t at_most;
210 	int limit;
211 	struct bufferevent *bev = &beva->bev.bev;
212 
213 	/* Don't write if there's a write in progress, or we do not
214 	 * want to write, or when there's nothing left to write. */
215 	if (beva->write_in_progress || beva->bev.connecting)
216 		return;
217 	if (!beva->ok || !(bev->enabled&EV_WRITE) ||
218 	    !evbuffer_get_length(bev->output)) {
219 		bev_async_del_write(beva);
220 		return;
221 	}
222 
223 	at_most = evbuffer_get_length(bev->output);
224 
225 	/* This is safe so long as bufferevent_get_write_max never returns
226 	 * more than INT_MAX.  That's true for now. XXXX */
227 	limit = (int)bufferevent_get_write_max_(&beva->bev);
228 	if (at_most >= (size_t)limit && limit >= 0)
229 		at_most = limit;
230 
231 	if (beva->bev.write_suspended) {
232 		bev_async_del_write(beva);
233 		return;
234 	}
235 
236 	/*  XXXX doesn't respect low-water mark very well. */
237 	bufferevent_incref_(bev);
238 	if (evbuffer_launch_write_(bev->output, at_most,
239 	    &beva->write_overlapped)) {
240 		bufferevent_decref_(bev);
241 		beva->ok = 0;
242 		be_async_run_eventcb(bev, BEV_EVENT_ERROR, 0);
243 	} else {
244 		beva->write_in_progress = at_most;
245 		bufferevent_decrement_write_buckets_(&beva->bev, at_most);
246 		bev_async_add_write(beva);
247 	}
248 }
249 
250 static void
bev_async_consider_reading(struct bufferevent_async * beva)251 bev_async_consider_reading(struct bufferevent_async *beva)
252 {
253 	size_t cur_size;
254 	size_t read_high;
255 	size_t at_most;
256 	int limit;
257 	struct bufferevent *bev = &beva->bev.bev;
258 
259 	/* Don't read if there is a read in progress, or we do not
260 	 * want to read. */
261 	if (beva->read_in_progress || beva->bev.connecting)
262 		return;
263 	if (!beva->ok || !(bev->enabled&EV_READ)) {
264 		bev_async_del_read(beva);
265 		return;
266 	}
267 
268 	/* Don't read if we're full */
269 	cur_size = evbuffer_get_length(bev->input);
270 	read_high = bev->wm_read.high;
271 	if (read_high) {
272 		if (cur_size >= read_high) {
273 			bev_async_del_read(beva);
274 			return;
275 		}
276 		at_most = read_high - cur_size;
277 	} else {
278 		at_most = 16384; /* FIXME totally magic. */
279 	}
280 
281 	/* XXXX This over-commits. */
282 	/* XXXX see also not above on cast on bufferevent_get_write_max_() */
283 	limit = (int)bufferevent_get_read_max_(&beva->bev);
284 	if (at_most >= (size_t)limit && limit >= 0)
285 		at_most = limit;
286 
287 	if (beva->bev.read_suspended) {
288 		bev_async_del_read(beva);
289 		return;
290 	}
291 
292 	bufferevent_incref_(bev);
293 	if (evbuffer_launch_read_(bev->input, at_most, &beva->read_overlapped)) {
294 		beva->ok = 0;
295 		be_async_run_eventcb(bev, BEV_EVENT_ERROR, 0);
296 		bufferevent_decref_(bev);
297 	} else {
298 		beva->read_in_progress = at_most;
299 		bufferevent_decrement_read_buckets_(&beva->bev, at_most);
300 		bev_async_add_read(beva);
301 	}
302 
303 	return;
304 }
305 
306 static void
be_async_outbuf_callback(struct evbuffer * buf,const struct evbuffer_cb_info * cbinfo,void * arg)307 be_async_outbuf_callback(struct evbuffer *buf,
308     const struct evbuffer_cb_info *cbinfo,
309     void *arg)
310 {
311 	struct bufferevent *bev = arg;
312 	struct bufferevent_async *bev_async = upcast(bev);
313 
314 	/* If we added data to the outbuf and were not writing before,
315 	 * we may want to write now. */
316 
317 	bufferevent_incref_and_lock_(bev);
318 
319 	if (cbinfo->n_added)
320 		bev_async_consider_writing(bev_async);
321 
322 	bufferevent_decref_and_unlock_(bev);
323 }
324 
325 static void
be_async_inbuf_callback(struct evbuffer * buf,const struct evbuffer_cb_info * cbinfo,void * arg)326 be_async_inbuf_callback(struct evbuffer *buf,
327     const struct evbuffer_cb_info *cbinfo,
328     void *arg)
329 {
330 	struct bufferevent *bev = arg;
331 	struct bufferevent_async *bev_async = upcast(bev);
332 
333 	/* If we drained data from the inbuf and were not reading before,
334 	 * we may want to read now */
335 
336 	bufferevent_incref_and_lock_(bev);
337 
338 	if (cbinfo->n_deleted)
339 		bev_async_consider_reading(bev_async);
340 
341 	bufferevent_decref_and_unlock_(bev);
342 }
343 
344 static int
be_async_enable(struct bufferevent * buf,short what)345 be_async_enable(struct bufferevent *buf, short what)
346 {
347 	struct bufferevent_async *bev_async = upcast(buf);
348 
349 	if (!bev_async->ok)
350 		return -1;
351 
352 	if (bev_async->bev.connecting) {
353 		/* Don't launch anything during connection attempts. */
354 		return 0;
355 	}
356 
357 	if (what & EV_READ)
358 		BEV_RESET_GENERIC_READ_TIMEOUT(buf);
359 	if (what & EV_WRITE)
360 		BEV_RESET_GENERIC_WRITE_TIMEOUT(buf);
361 
362 	/* If we newly enable reading or writing, and we aren't reading or
363 	   writing already, consider launching a new read or write. */
364 
365 	if (what & EV_READ)
366 		bev_async_consider_reading(bev_async);
367 	if (what & EV_WRITE)
368 		bev_async_consider_writing(bev_async);
369 	return 0;
370 }
371 
372 static int
be_async_disable(struct bufferevent * bev,short what)373 be_async_disable(struct bufferevent *bev, short what)
374 {
375 	struct bufferevent_async *bev_async = upcast(bev);
376 	/* XXXX If we disable reading or writing, we may want to consider
377 	 * canceling any in-progress read or write operation, though it might
378 	 * not work. */
379 
380 	if (what & EV_READ) {
381 		BEV_DEL_GENERIC_READ_TIMEOUT(bev);
382 		bev_async_del_read(bev_async);
383 	}
384 	if (what & EV_WRITE) {
385 		BEV_DEL_GENERIC_WRITE_TIMEOUT(bev);
386 		bev_async_del_write(bev_async);
387 	}
388 
389 	return 0;
390 }
391 
392 static void
be_async_destruct(struct bufferevent * bev)393 be_async_destruct(struct bufferevent *bev)
394 {
395 	struct bufferevent_async *bev_async = upcast(bev);
396 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
397 	evutil_socket_t fd;
398 
399 	EVUTIL_ASSERT(!upcast(bev)->write_in_progress &&
400 			!upcast(bev)->read_in_progress);
401 
402 	bev_async_del_read(bev_async);
403 	bev_async_del_write(bev_async);
404 
405 	fd = evbuffer_overlapped_get_fd_(bev->input);
406 	if (fd != (evutil_socket_t)EVUTIL_INVALID_SOCKET &&
407 		(bev_p->options & BEV_OPT_CLOSE_ON_FREE)) {
408 		evutil_closesocket(fd);
409 		evbuffer_overlapped_set_fd_(bev->input, EVUTIL_INVALID_SOCKET);
410 	}
411 }
412 
413 /* GetQueuedCompletionStatus doesn't reliably yield WSA error codes, so
414  * we use WSAGetOverlappedResult to translate. */
415 static void
bev_async_set_wsa_error(struct bufferevent * bev,struct event_overlapped * eo)416 bev_async_set_wsa_error(struct bufferevent *bev, struct event_overlapped *eo)
417 {
418 	DWORD bytes, flags;
419 	evutil_socket_t fd;
420 
421 	fd = evbuffer_overlapped_get_fd_(bev->input);
422 	WSAGetOverlappedResult(fd, &eo->overlapped, &bytes, FALSE, &flags);
423 }
424 
425 static int
be_async_flush(struct bufferevent * bev,short what,enum bufferevent_flush_mode mode)426 be_async_flush(struct bufferevent *bev, short what,
427     enum bufferevent_flush_mode mode)
428 {
429 	return 0;
430 }
431 
432 static void
connect_complete(struct event_overlapped * eo,ev_uintptr_t key,ev_ssize_t nbytes,int ok)433 connect_complete(struct event_overlapped *eo, ev_uintptr_t key,
434     ev_ssize_t nbytes, int ok)
435 {
436 	struct bufferevent_async *bev_a = upcast_connect(eo);
437 	struct bufferevent *bev = &bev_a->bev.bev;
438 	evutil_socket_t sock;
439 
440 	BEV_LOCK(bev);
441 
442 	EVUTIL_ASSERT(bev_a->bev.connecting);
443 	bev_a->bev.connecting = 0;
444 	sock = evbuffer_overlapped_get_fd_(bev_a->bev.bev.input);
445 	/* XXXX Handle error? */
446 	setsockopt(sock, SOL_SOCKET, SO_UPDATE_CONNECT_CONTEXT, NULL, 0);
447 
448 	if (ok)
449 		bufferevent_async_set_connected_(bev);
450 	else
451 		bev_async_set_wsa_error(bev, eo);
452 
453 	be_async_run_eventcb(bev, ok ? BEV_EVENT_CONNECTED : BEV_EVENT_ERROR, 0);
454 
455 	event_base_del_virtual_(bev->ev_base);
456 
457 	bufferevent_decref_and_unlock_(bev);
458 }
459 
460 static void
read_complete(struct event_overlapped * eo,ev_uintptr_t key,ev_ssize_t nbytes,int ok)461 read_complete(struct event_overlapped *eo, ev_uintptr_t key,
462     ev_ssize_t nbytes, int ok)
463 {
464 	struct bufferevent_async *bev_a = upcast_read(eo);
465 	struct bufferevent *bev = &bev_a->bev.bev;
466 	short what = BEV_EVENT_READING;
467 	ev_ssize_t amount_unread;
468 	BEV_LOCK(bev);
469 	EVUTIL_ASSERT(bev_a->read_in_progress);
470 
471 	amount_unread = bev_a->read_in_progress - nbytes;
472 	evbuffer_commit_read_(bev->input, nbytes);
473 	bev_a->read_in_progress = 0;
474 	if (amount_unread)
475 		bufferevent_decrement_read_buckets_(&bev_a->bev, -amount_unread);
476 
477 	if (!ok)
478 		bev_async_set_wsa_error(bev, eo);
479 
480 	if (bev_a->ok) {
481 		if (ok && nbytes) {
482 			BEV_RESET_GENERIC_READ_TIMEOUT(bev);
483 			be_async_trigger_nolock(bev, EV_READ, 0);
484 			bev_async_consider_reading(bev_a);
485 		} else if (!ok) {
486 			what |= BEV_EVENT_ERROR;
487 			bev_a->ok = 0;
488 			be_async_run_eventcb(bev, what, 0);
489 		} else if (!nbytes) {
490 			what |= BEV_EVENT_EOF;
491 			bev_a->ok = 0;
492 			be_async_run_eventcb(bev, what, 0);
493 		}
494 	}
495 
496 	bufferevent_decref_and_unlock_(bev);
497 }
498 
499 static void
write_complete(struct event_overlapped * eo,ev_uintptr_t key,ev_ssize_t nbytes,int ok)500 write_complete(struct event_overlapped *eo, ev_uintptr_t key,
501     ev_ssize_t nbytes, int ok)
502 {
503 	struct bufferevent_async *bev_a = upcast_write(eo);
504 	struct bufferevent *bev = &bev_a->bev.bev;
505 	short what = BEV_EVENT_WRITING;
506 	ev_ssize_t amount_unwritten;
507 
508 	BEV_LOCK(bev);
509 	EVUTIL_ASSERT(bev_a->write_in_progress);
510 
511 	amount_unwritten = bev_a->write_in_progress - nbytes;
512 	evbuffer_commit_write_(bev->output, nbytes);
513 	bev_a->write_in_progress = 0;
514 
515 	if (amount_unwritten)
516 		bufferevent_decrement_write_buckets_(&bev_a->bev,
517 		                                     -amount_unwritten);
518 
519 
520 	if (!ok)
521 		bev_async_set_wsa_error(bev, eo);
522 
523 	if (bev_a->ok) {
524 		if (ok && nbytes) {
525 			BEV_RESET_GENERIC_WRITE_TIMEOUT(bev);
526 			be_async_trigger_nolock(bev, EV_WRITE, 0);
527 			bev_async_consider_writing(bev_a);
528 		} else if (!ok) {
529 			what |= BEV_EVENT_ERROR;
530 			bev_a->ok = 0;
531 			be_async_run_eventcb(bev, what, 0);
532 		} else if (!nbytes) {
533 			what |= BEV_EVENT_EOF;
534 			bev_a->ok = 0;
535 			be_async_run_eventcb(bev, what, 0);
536 		}
537 	}
538 
539 	bufferevent_decref_and_unlock_(bev);
540 }
541 
542 struct bufferevent *
bufferevent_async_new_(struct event_base * base,evutil_socket_t fd,int options)543 bufferevent_async_new_(struct event_base *base,
544     evutil_socket_t fd, int options)
545 {
546 	struct bufferevent_async *bev_a;
547 	struct bufferevent *bev;
548 	struct event_iocp_port *iocp;
549 
550 	options |= BEV_OPT_THREADSAFE;
551 
552 	if (!(iocp = event_base_get_iocp_(base)))
553 		return NULL;
554 
555 	if (fd >= 0 && event_iocp_port_associate_(iocp, fd, 1)<0) {
556 		if (fatal_error(GetLastError()))
557 			return NULL;
558 	}
559 
560 	if (!(bev_a = mm_calloc(1, sizeof(struct bufferevent_async))))
561 		return NULL;
562 
563 	bev = &bev_a->bev.bev;
564 	if (!(bev->input = evbuffer_overlapped_new_(fd))) {
565 		mm_free(bev_a);
566 		return NULL;
567 	}
568 	if (!(bev->output = evbuffer_overlapped_new_(fd))) {
569 		evbuffer_free(bev->input);
570 		mm_free(bev_a);
571 		return NULL;
572 	}
573 
574 	if (bufferevent_init_common_(&bev_a->bev, base, &bufferevent_ops_async,
575 		options)<0)
576 		goto err;
577 
578 	evbuffer_add_cb(bev->input, be_async_inbuf_callback, bev);
579 	evbuffer_add_cb(bev->output, be_async_outbuf_callback, bev);
580 
581 	event_overlapped_init_(&bev_a->connect_overlapped, connect_complete);
582 	event_overlapped_init_(&bev_a->read_overlapped, read_complete);
583 	event_overlapped_init_(&bev_a->write_overlapped, write_complete);
584 
585 	bufferevent_init_generic_timeout_cbs_(bev);
586 
587 	bev_a->ok = fd >= 0;
588 
589 	return bev;
590 err:
591 	bufferevent_free(&bev_a->bev.bev);
592 	return NULL;
593 }
594 
595 void
bufferevent_async_set_connected_(struct bufferevent * bev)596 bufferevent_async_set_connected_(struct bufferevent *bev)
597 {
598 	struct bufferevent_async *bev_async = upcast(bev);
599 	bev_async->ok = 1;
600 	/* Now's a good time to consider reading/writing */
601 	be_async_enable(bev, bev->enabled);
602 }
603 
604 int
bufferevent_async_can_connect_(struct bufferevent * bev)605 bufferevent_async_can_connect_(struct bufferevent *bev)
606 {
607 	const struct win32_extension_fns *ext =
608 	    event_get_win32_extension_fns_();
609 
610 	if (BEV_IS_ASYNC(bev) &&
611 	    event_base_get_iocp_(bev->ev_base) &&
612 	    ext && ext->ConnectEx)
613 		return 1;
614 
615 	return 0;
616 }
617 
618 int
bufferevent_async_connect_(struct bufferevent * bev,evutil_socket_t fd,const struct sockaddr * sa,int socklen)619 bufferevent_async_connect_(struct bufferevent *bev, evutil_socket_t fd,
620 	const struct sockaddr *sa, int socklen)
621 {
622 	BOOL rc;
623 	struct bufferevent_async *bev_async = upcast(bev);
624 	struct sockaddr_storage ss;
625 	const struct win32_extension_fns *ext =
626 	    event_get_win32_extension_fns_();
627 
628 	EVUTIL_ASSERT(ext && ext->ConnectEx && fd >= 0 && sa != NULL);
629 
630 	/* ConnectEx() requires that the socket be bound to an address
631 	 * with bind() before using, otherwise it will fail. We attempt
632 	 * to issue a bind() here, taking into account that the error
633 	 * code is set to WSAEINVAL when the socket is already bound. */
634 	memset(&ss, 0, sizeof(ss));
635 	if (sa->sa_family == AF_INET) {
636 		struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
637 		sin->sin_family = AF_INET;
638 		sin->sin_addr.s_addr = INADDR_ANY;
639 	} else if (sa->sa_family == AF_INET6) {
640 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
641 		sin6->sin6_family = AF_INET6;
642 		sin6->sin6_addr = in6addr_any;
643 	} else {
644 		/* Well, the user will have to bind() */
645 		return -1;
646 	}
647 	if (bind(fd, (struct sockaddr *)&ss, sizeof(ss)) < 0 &&
648 	    WSAGetLastError() != WSAEINVAL)
649 		return -1;
650 
651 	event_base_add_virtual_(bev->ev_base);
652 	bufferevent_incref_(bev);
653 	rc = ext->ConnectEx(fd, sa, socklen, NULL, 0, NULL,
654 			    &bev_async->connect_overlapped.overlapped);
655 	if (rc || WSAGetLastError() == ERROR_IO_PENDING)
656 		return 0;
657 
658 	event_base_del_virtual_(bev->ev_base);
659 	bufferevent_decref_(bev);
660 
661 	return -1;
662 }
663 
664 static int
be_async_ctrl(struct bufferevent * bev,enum bufferevent_ctrl_op op,union bufferevent_ctrl_data * data)665 be_async_ctrl(struct bufferevent *bev, enum bufferevent_ctrl_op op,
666     union bufferevent_ctrl_data *data)
667 {
668 	switch (op) {
669 	case BEV_CTRL_GET_FD:
670 		data->fd = evbuffer_overlapped_get_fd_(bev->input);
671 		return 0;
672 	case BEV_CTRL_SET_FD: {
673 		struct bufferevent_async *bev_a = upcast(bev);
674 		struct event_iocp_port *iocp;
675 
676 		if (data->fd == evbuffer_overlapped_get_fd_(bev->input))
677 			return 0;
678 		if (!(iocp = event_base_get_iocp_(bev->ev_base)))
679 			return -1;
680 		if (event_iocp_port_associate_(iocp, data->fd, 1) < 0) {
681 			if (fatal_error(GetLastError()))
682 				return -1;
683 		}
684 		evbuffer_overlapped_set_fd_(bev->input, data->fd);
685 		evbuffer_overlapped_set_fd_(bev->output, data->fd);
686 		bev_a->ok = data->fd >= 0;
687 		return 0;
688 	}
689 	case BEV_CTRL_CANCEL_ALL: {
690 		struct bufferevent_async *bev_a = upcast(bev);
691 		evutil_socket_t fd = evbuffer_overlapped_get_fd_(bev->input);
692 		if (fd != (evutil_socket_t)EVUTIL_INVALID_SOCKET &&
693 		    (bev_a->bev.options & BEV_OPT_CLOSE_ON_FREE)) {
694 			closesocket(fd);
695 			evbuffer_overlapped_set_fd_(bev->input, EVUTIL_INVALID_SOCKET);
696 		}
697 		bev_a->ok = 0;
698 		return 0;
699 	}
700 	case BEV_CTRL_GET_UNDERLYING:
701 	default:
702 		return -1;
703 	}
704 }
705 
706 
707