xref: /freebsd/contrib/ntp/sntp/libevent/bufferevent_sock.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*
2  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
3  * Copyright (c) 2002-2006 Niels Provos <provos@citi.umich.edu>
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 #include <sys/types.h>
33 
34 #ifdef EVENT__HAVE_SYS_TIME_H
35 #include <sys/time.h>
36 #endif
37 
38 #include <errno.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #ifdef EVENT__HAVE_STDARG_H
43 #include <stdarg.h>
44 #endif
45 #ifdef EVENT__HAVE_UNISTD_H
46 #include <unistd.h>
47 #endif
48 
49 #ifdef _WIN32
50 #include <winsock2.h>
51 #include <ws2tcpip.h>
52 #endif
53 
54 #ifdef EVENT__HAVE_SYS_SOCKET_H
55 #include <sys/socket.h>
56 #endif
57 #ifdef EVENT__HAVE_NETINET_IN_H
58 #include <netinet/in.h>
59 #endif
60 #ifdef EVENT__HAVE_NETINET_IN6_H
61 #include <netinet/in6.h>
62 #endif
63 
64 #include "event2/util.h"
65 #include "event2/bufferevent.h"
66 #include "event2/buffer.h"
67 #include "event2/bufferevent_struct.h"
68 #include "event2/bufferevent_compat.h"
69 #include "event2/event.h"
70 #include "log-internal.h"
71 #include "mm-internal.h"
72 #include "bufferevent-internal.h"
73 #include "util-internal.h"
74 #ifdef _WIN32
75 #include "iocp-internal.h"
76 #endif
77 
78 /* prototypes */
79 static int be_socket_enable(struct bufferevent *, short);
80 static int be_socket_disable(struct bufferevent *, short);
81 static void be_socket_destruct(struct bufferevent *);
82 static int be_socket_flush(struct bufferevent *, short, enum bufferevent_flush_mode);
83 static int be_socket_ctrl(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *);
84 
85 static void be_socket_setfd(struct bufferevent *, evutil_socket_t);
86 
87 const struct bufferevent_ops bufferevent_ops_socket = {
88 	"socket",
89 	evutil_offsetof(struct bufferevent_private, bev),
90 	be_socket_enable,
91 	be_socket_disable,
92 	NULL, /* unlink */
93 	be_socket_destruct,
94 	bufferevent_generic_adj_existing_timeouts_,
95 	be_socket_flush,
96 	be_socket_ctrl,
97 };
98 
99 const struct sockaddr*
100 bufferevent_socket_get_conn_address_(struct bufferevent *bev)
101 {
102 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
103 	return (struct sockaddr *)&bev_p->conn_address;
104 }
105 
106 void
107 bufferevent_socket_set_conn_address_fd_(struct bufferevent *bev,
108 	evutil_socket_t fd)
109 {
110 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
111 
112 	socklen_t len = sizeof(bev_p->conn_address);
113 
114 	struct sockaddr *addr = (struct sockaddr *)&bev_p->conn_address;
115 	if (addr->sa_family != AF_UNSPEC)
116 		getpeername(fd, addr, &len);
117 }
118 
119 void
120 bufferevent_socket_set_conn_address_(struct bufferevent *bev,
121 	struct sockaddr *addr, size_t addrlen)
122 {
123 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
124 	EVUTIL_ASSERT(addrlen <= sizeof(bev_p->conn_address));
125 	memcpy(&bev_p->conn_address, addr, addrlen);
126 }
127 
128 static void
129 bufferevent_socket_outbuf_cb(struct evbuffer *buf,
130     const struct evbuffer_cb_info *cbinfo,
131     void *arg)
132 {
133 	struct bufferevent *bufev = arg;
134 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
135 
136 	if (cbinfo->n_added &&
137 	    (bufev->enabled & EV_WRITE) &&
138 	    !event_pending(&bufev->ev_write, EV_WRITE, NULL) &&
139 	    !bufev_p->write_suspended) {
140 		/* Somebody added data to the buffer, and we would like to
141 		 * write, and we were not writing.  So, start writing. */
142 		if (bufferevent_add_event_(&bufev->ev_write, &bufev->timeout_write) == -1) {
143 		    /* Should we log this? */
144 		}
145 	}
146 }
147 
148 static void
149 bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
150 {
151 	struct bufferevent *bufev = arg;
152 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
153 	struct evbuffer *input;
154 	int res = 0;
155 	short what = BEV_EVENT_READING;
156 	ev_ssize_t howmuch = -1, readmax=-1;
157 
158 	bufferevent_incref_and_lock_(bufev);
159 
160 	if (event == EV_TIMEOUT) {
161 		/* Note that we only check for event==EV_TIMEOUT. If
162 		 * event==EV_TIMEOUT|EV_READ, we can safely ignore the
163 		 * timeout, since a read has occurred */
164 		what |= BEV_EVENT_TIMEOUT;
165 		goto error;
166 	}
167 
168 	input = bufev->input;
169 
170 	/*
171 	 * If we have a high watermark configured then we don't want to
172 	 * read more data than would make us reach the watermark.
173 	 */
174 	if (bufev->wm_read.high != 0) {
175 		howmuch = bufev->wm_read.high - evbuffer_get_length(input);
176 		/* we somehow lowered the watermark, stop reading */
177 		if (howmuch <= 0) {
178 			bufferevent_wm_suspend_read(bufev);
179 			goto done;
180 		}
181 	}
182 	readmax = bufferevent_get_read_max_(bufev_p);
183 	if (howmuch < 0 || howmuch > readmax) /* The use of -1 for "unlimited"
184 					       * uglifies this code. XXXX */
185 		howmuch = readmax;
186 	if (bufev_p->read_suspended)
187 		goto done;
188 
189 	evbuffer_unfreeze(input, 0);
190 	res = evbuffer_read(input, fd, (int)howmuch); /* XXXX evbuffer_read would do better to take and return ev_ssize_t */
191 	evbuffer_freeze(input, 0);
192 
193 	if (res == -1) {
194 		int err = evutil_socket_geterror(fd);
195 		if (EVUTIL_ERR_RW_RETRIABLE(err))
196 			goto reschedule;
197 		if (EVUTIL_ERR_CONNECT_REFUSED(err)) {
198 			bufev_p->connection_refused = 1;
199 			goto done;
200 		}
201 		/* error case */
202 		what |= BEV_EVENT_ERROR;
203 	} else if (res == 0) {
204 		/* eof case */
205 		what |= BEV_EVENT_EOF;
206 	}
207 
208 	if (res <= 0)
209 		goto error;
210 
211 	bufferevent_decrement_read_buckets_(bufev_p, res);
212 
213 	/* Invoke the user callback - must always be called last */
214 	bufferevent_trigger_nolock_(bufev, EV_READ, 0);
215 
216 	goto done;
217 
218  reschedule:
219 	goto done;
220 
221  error:
222 	bufferevent_disable(bufev, EV_READ);
223 	bufferevent_run_eventcb_(bufev, what, 0);
224 
225  done:
226 	bufferevent_decref_and_unlock_(bufev);
227 }
228 
229 static void
230 bufferevent_writecb(evutil_socket_t fd, short event, void *arg)
231 {
232 	struct bufferevent *bufev = arg;
233 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
234 	int res = 0;
235 	short what = BEV_EVENT_WRITING;
236 	int connected = 0;
237 	ev_ssize_t atmost = -1;
238 
239 	bufferevent_incref_and_lock_(bufev);
240 
241 	if (event == EV_TIMEOUT) {
242 		/* Note that we only check for event==EV_TIMEOUT. If
243 		 * event==EV_TIMEOUT|EV_WRITE, we can safely ignore the
244 		 * timeout, since a read has occurred */
245 		what |= BEV_EVENT_TIMEOUT;
246 		goto error;
247 	}
248 	if (bufev_p->connecting) {
249 		int c = evutil_socket_finished_connecting_(fd);
250 		/* we need to fake the error if the connection was refused
251 		 * immediately - usually connection to localhost on BSD */
252 		if (bufev_p->connection_refused) {
253 			bufev_p->connection_refused = 0;
254 			c = -1;
255 		}
256 
257 		if (c == 0)
258 			goto done;
259 
260 		bufev_p->connecting = 0;
261 		if (c < 0) {
262 			event_del(&bufev->ev_write);
263 			event_del(&bufev->ev_read);
264 			bufferevent_run_eventcb_(bufev, BEV_EVENT_ERROR, 0);
265 			goto done;
266 		} else {
267 			connected = 1;
268 			bufferevent_socket_set_conn_address_fd_(bufev, fd);
269 #ifdef _WIN32
270 			if (BEV_IS_ASYNC(bufev)) {
271 				event_del(&bufev->ev_write);
272 				bufferevent_async_set_connected_(bufev);
273 				bufferevent_run_eventcb_(bufev,
274 						BEV_EVENT_CONNECTED, 0);
275 				goto done;
276 			}
277 #endif
278 			bufferevent_run_eventcb_(bufev,
279 					BEV_EVENT_CONNECTED, 0);
280 			if (!(bufev->enabled & EV_WRITE) ||
281 			    bufev_p->write_suspended) {
282 				event_del(&bufev->ev_write);
283 				goto done;
284 			}
285 		}
286 	}
287 
288 	atmost = bufferevent_get_write_max_(bufev_p);
289 
290 	if (bufev_p->write_suspended)
291 		goto done;
292 
293 	if (evbuffer_get_length(bufev->output)) {
294 		evbuffer_unfreeze(bufev->output, 1);
295 		res = evbuffer_write_atmost(bufev->output, fd, atmost);
296 		evbuffer_freeze(bufev->output, 1);
297 		if (res == -1) {
298 			int err = evutil_socket_geterror(fd);
299 			if (EVUTIL_ERR_RW_RETRIABLE(err))
300 				goto reschedule;
301 			what |= BEV_EVENT_ERROR;
302 		} else if (res == 0) {
303 			/* eof case
304 			   XXXX Actually, a 0 on write doesn't indicate
305 			   an EOF. An ECONNRESET might be more typical.
306 			 */
307 			what |= BEV_EVENT_EOF;
308 		}
309 		if (res <= 0)
310 			goto error;
311 
312 		bufferevent_decrement_write_buckets_(bufev_p, res);
313 	}
314 
315 	if (evbuffer_get_length(bufev->output) == 0) {
316 		event_del(&bufev->ev_write);
317 	}
318 
319 	/*
320 	 * Invoke the user callback if our buffer is drained or below the
321 	 * low watermark.
322 	 */
323 	if (res || !connected) {
324 		bufferevent_trigger_nolock_(bufev, EV_WRITE, 0);
325 	}
326 
327 	goto done;
328 
329  reschedule:
330 	if (evbuffer_get_length(bufev->output) == 0) {
331 		event_del(&bufev->ev_write);
332 	}
333 	goto done;
334 
335  error:
336 	bufferevent_disable(bufev, EV_WRITE);
337 	bufferevent_run_eventcb_(bufev, what, 0);
338 
339  done:
340 	bufferevent_decref_and_unlock_(bufev);
341 }
342 
343 struct bufferevent *
344 bufferevent_socket_new(struct event_base *base, evutil_socket_t fd,
345     int options)
346 {
347 	struct bufferevent_private *bufev_p;
348 	struct bufferevent *bufev;
349 
350 #ifdef _WIN32
351 	if (base && event_base_get_iocp_(base))
352 		return bufferevent_async_new_(base, fd, options);
353 #endif
354 
355 	if ((bufev_p = mm_calloc(1, sizeof(struct bufferevent_private)))== NULL)
356 		return NULL;
357 
358 	if (bufferevent_init_common_(bufev_p, base, &bufferevent_ops_socket,
359 				    options) < 0) {
360 		mm_free(bufev_p);
361 		return NULL;
362 	}
363 	bufev = &bufev_p->bev;
364 	evbuffer_set_flags(bufev->output, EVBUFFER_FLAG_DRAINS_TO_FD);
365 
366 	event_assign(&bufev->ev_read, bufev->ev_base, fd,
367 	    EV_READ|EV_PERSIST|EV_FINALIZE, bufferevent_readcb, bufev);
368 	event_assign(&bufev->ev_write, bufev->ev_base, fd,
369 	    EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bufev);
370 
371 	evbuffer_add_cb(bufev->output, bufferevent_socket_outbuf_cb, bufev);
372 
373 	evbuffer_freeze(bufev->input, 0);
374 	evbuffer_freeze(bufev->output, 1);
375 
376 	return bufev;
377 }
378 
379 int
380 bufferevent_socket_connect(struct bufferevent *bev,
381     const struct sockaddr *sa, int socklen)
382 {
383 	struct bufferevent_private *bufev_p = BEV_UPCAST(bev);
384 
385 	evutil_socket_t fd;
386 	int r = 0;
387 	int result=-1;
388 	int ownfd = 0;
389 
390 	bufferevent_incref_and_lock_(bev);
391 
392 	fd = bufferevent_getfd(bev);
393 	if (fd < 0) {
394 		if (!sa)
395 			goto done;
396 		fd = evutil_socket_(sa->sa_family,
397 		    SOCK_STREAM|EVUTIL_SOCK_NONBLOCK, 0);
398 		if (fd < 0)
399 			goto freesock;
400 		ownfd = 1;
401 	}
402 	if (sa) {
403 #ifdef _WIN32
404 		if (bufferevent_async_can_connect_(bev)) {
405 			bufferevent_setfd(bev, fd);
406 			r = bufferevent_async_connect_(bev, fd, sa, socklen);
407 			if (r < 0)
408 				goto freesock;
409 			bufev_p->connecting = 1;
410 			result = 0;
411 			goto done;
412 		} else
413 #endif
414 		r = evutil_socket_connect_(&fd, sa, socklen);
415 		if (r < 0)
416 			goto freesock;
417 	}
418 #ifdef _WIN32
419 	/* ConnectEx() isn't always around, even when IOCP is enabled.
420 	 * Here, we borrow the socket object's write handler to fall back
421 	 * on a non-blocking connect() when ConnectEx() is unavailable. */
422 	if (BEV_IS_ASYNC(bev)) {
423 		event_assign(&bev->ev_write, bev->ev_base, fd,
424 		    EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bev);
425 	}
426 #endif
427 	bufferevent_setfd(bev, fd);
428 	if (r == 0) {
429 		if (! be_socket_enable(bev, EV_WRITE)) {
430 			bufev_p->connecting = 1;
431 			result = 0;
432 			goto done;
433 		}
434 	} else if (r == 1) {
435 		/* The connect succeeded already. How very BSD of it. */
436 		result = 0;
437 		bufev_p->connecting = 1;
438 		bufferevent_trigger_nolock_(bev, EV_WRITE, BEV_OPT_DEFER_CALLBACKS);
439 	} else {
440 		/* The connect failed already.  How very BSD of it. */
441 		result = 0;
442 		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, BEV_OPT_DEFER_CALLBACKS);
443 		bufferevent_disable(bev, EV_WRITE|EV_READ);
444 	}
445 
446 	goto done;
447 
448 freesock:
449 	if (ownfd)
450 		evutil_closesocket(fd);
451 done:
452 	bufferevent_decref_and_unlock_(bev);
453 	return result;
454 }
455 
456 static void
457 bufferevent_connect_getaddrinfo_cb(int result, struct evutil_addrinfo *ai,
458     void *arg)
459 {
460 	struct bufferevent *bev = arg;
461 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
462 	int r;
463 	BEV_LOCK(bev);
464 
465 	bufferevent_unsuspend_write_(bev, BEV_SUSPEND_LOOKUP);
466 	bufferevent_unsuspend_read_(bev, BEV_SUSPEND_LOOKUP);
467 
468 	bev_p->dns_request = NULL;
469 
470 	if (result == EVUTIL_EAI_CANCEL) {
471 		bev_p->dns_error = result;
472 		bufferevent_decref_and_unlock_(bev);
473 		return;
474 	}
475 	if (result != 0) {
476 		bev_p->dns_error = result;
477 		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
478 		bufferevent_decref_and_unlock_(bev);
479 		if (ai)
480 			evutil_freeaddrinfo(ai);
481 		return;
482 	}
483 
484 	/* XXX use the other addrinfos? */
485 	bufferevent_socket_set_conn_address_(bev, ai->ai_addr, (int)ai->ai_addrlen);
486 	r = bufferevent_socket_connect(bev, ai->ai_addr, (int)ai->ai_addrlen);
487 	if (r < 0)
488 		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
489 	bufferevent_decref_and_unlock_(bev);
490 	evutil_freeaddrinfo(ai);
491 }
492 
493 int
494 bufferevent_socket_connect_hostname(struct bufferevent *bev,
495     struct evdns_base *evdns_base, int family, const char *hostname, int port)
496 {
497 	char portbuf[10];
498 	struct evutil_addrinfo hint;
499 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
500 
501 	if (family != AF_INET && family != AF_INET6 && family != AF_UNSPEC)
502 		return -1;
503 	if (port < 1 || port > 65535)
504 		return -1;
505 
506 	memset(&hint, 0, sizeof(hint));
507 	hint.ai_family = family;
508 	hint.ai_protocol = IPPROTO_TCP;
509 	hint.ai_socktype = SOCK_STREAM;
510 
511 	evutil_snprintf(portbuf, sizeof(portbuf), "%d", port);
512 
513 	BEV_LOCK(bev);
514 	bev_p->dns_error = 0;
515 
516 	bufferevent_suspend_write_(bev, BEV_SUSPEND_LOOKUP);
517 	bufferevent_suspend_read_(bev, BEV_SUSPEND_LOOKUP);
518 
519 	bufferevent_incref_(bev);
520 	bev_p->dns_request = evutil_getaddrinfo_async_(evdns_base, hostname,
521 	    portbuf, &hint, bufferevent_connect_getaddrinfo_cb, bev);
522 	BEV_UNLOCK(bev);
523 
524 	return 0;
525 }
526 
527 int
528 bufferevent_socket_get_dns_error(struct bufferevent *bev)
529 {
530 	int rv;
531 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
532 
533 	BEV_LOCK(bev);
534 	rv = bev_p->dns_error;
535 	BEV_UNLOCK(bev);
536 
537 	return rv;
538 }
539 
540 /*
541  * Create a new buffered event object.
542  *
543  * The read callback is invoked whenever we read new data.
544  * The write callback is invoked whenever the output buffer is drained.
545  * The error callback is invoked on a write/read error or on EOF.
546  *
547  * Both read and write callbacks maybe NULL.  The error callback is not
548  * allowed to be NULL and have to be provided always.
549  */
550 
551 struct bufferevent *
552 bufferevent_new(evutil_socket_t fd,
553     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
554     bufferevent_event_cb eventcb, void *cbarg)
555 {
556 	struct bufferevent *bufev;
557 
558 	if (!(bufev = bufferevent_socket_new(NULL, fd, 0)))
559 		return NULL;
560 
561 	bufferevent_setcb(bufev, readcb, writecb, eventcb, cbarg);
562 
563 	return bufev;
564 }
565 
566 
567 static int
568 be_socket_enable(struct bufferevent *bufev, short event)
569 {
570 	if (event & EV_READ &&
571 	    bufferevent_add_event_(&bufev->ev_read, &bufev->timeout_read) == -1)
572 			return -1;
573 	if (event & EV_WRITE &&
574 	    bufferevent_add_event_(&bufev->ev_write, &bufev->timeout_write) == -1)
575 			return -1;
576 	return 0;
577 }
578 
579 static int
580 be_socket_disable(struct bufferevent *bufev, short event)
581 {
582 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
583 	if (event & EV_READ) {
584 		if (event_del(&bufev->ev_read) == -1)
585 			return -1;
586 	}
587 	/* Don't actually disable the write if we are trying to connect. */
588 	if ((event & EV_WRITE) && ! bufev_p->connecting) {
589 		if (event_del(&bufev->ev_write) == -1)
590 			return -1;
591 	}
592 	return 0;
593 }
594 
595 static void
596 be_socket_destruct(struct bufferevent *bufev)
597 {
598 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
599 	evutil_socket_t fd;
600 	EVUTIL_ASSERT(BEV_IS_SOCKET(bufev));
601 
602 	fd = event_get_fd(&bufev->ev_read);
603 
604 	if ((bufev_p->options & BEV_OPT_CLOSE_ON_FREE) && fd >= 0)
605 		EVUTIL_CLOSESOCKET(fd);
606 
607 	evutil_getaddrinfo_cancel_async_(bufev_p->dns_request);
608 }
609 
610 static int
611 be_socket_flush(struct bufferevent *bev, short iotype,
612     enum bufferevent_flush_mode mode)
613 {
614 	return 0;
615 }
616 
617 
618 static void
619 be_socket_setfd(struct bufferevent *bufev, evutil_socket_t fd)
620 {
621 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
622 
623 	BEV_LOCK(bufev);
624 	EVUTIL_ASSERT(BEV_IS_SOCKET(bufev));
625 
626 	event_del(&bufev->ev_read);
627 	event_del(&bufev->ev_write);
628 
629 	evbuffer_unfreeze(bufev->input, 0);
630 	evbuffer_unfreeze(bufev->output, 1);
631 
632 	event_assign(&bufev->ev_read, bufev->ev_base, fd,
633 	    EV_READ|EV_PERSIST|EV_FINALIZE, bufferevent_readcb, bufev);
634 	event_assign(&bufev->ev_write, bufev->ev_base, fd,
635 	    EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bufev);
636 
637 	if (fd >= 0)
638 		bufferevent_enable(bufev, bufev->enabled);
639 
640 	evutil_getaddrinfo_cancel_async_(bufev_p->dns_request);
641 
642 	BEV_UNLOCK(bufev);
643 }
644 
645 /* XXXX Should non-socket bufferevents support this? */
646 int
647 bufferevent_priority_set(struct bufferevent *bufev, int priority)
648 {
649 	int r = -1;
650 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
651 
652 	BEV_LOCK(bufev);
653 	if (BEV_IS_ASYNC(bufev) || BEV_IS_FILTER(bufev) || BEV_IS_PAIR(bufev))
654 		goto done;
655 
656 	if (event_priority_set(&bufev->ev_read, priority) == -1)
657 		goto done;
658 	if (event_priority_set(&bufev->ev_write, priority) == -1)
659 		goto done;
660 
661 	event_deferred_cb_set_priority_(&bufev_p->deferred, priority);
662 
663 	r = 0;
664 done:
665 	BEV_UNLOCK(bufev);
666 	return r;
667 }
668 
669 /* XXXX Should non-socket bufferevents support this? */
670 int
671 bufferevent_base_set(struct event_base *base, struct bufferevent *bufev)
672 {
673 	int res = -1;
674 
675 	BEV_LOCK(bufev);
676 	if (!BEV_IS_SOCKET(bufev))
677 		goto done;
678 
679 	bufev->ev_base = base;
680 
681 	res = event_base_set(base, &bufev->ev_read);
682 	if (res == -1)
683 		goto done;
684 
685 	res = event_base_set(base, &bufev->ev_write);
686 done:
687 	BEV_UNLOCK(bufev);
688 	return res;
689 }
690 
691 static int
692 be_socket_ctrl(struct bufferevent *bev, enum bufferevent_ctrl_op op,
693     union bufferevent_ctrl_data *data)
694 {
695 	switch (op) {
696 	case BEV_CTRL_SET_FD:
697 		be_socket_setfd(bev, data->fd);
698 		return 0;
699 	case BEV_CTRL_GET_FD:
700 		data->fd = event_get_fd(&bev->ev_read);
701 		return 0;
702 	case BEV_CTRL_GET_UNDERLYING:
703 	case BEV_CTRL_CANCEL_ALL:
704 	default:
705 		return -1;
706 	}
707 }
708