xref: /netbsd-src/external/bsd/ntp/dist/sntp/libevent/bufferevent_sock.c (revision eabc0478de71e4e011a5b4e0392741e01d491794)
1 /*	$NetBSD: bufferevent_sock.c,v 1.6 2024/08/18 20:47:21 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
5  * Copyright (c) 2002-2006 Niels Provos <provos@citi.umich.edu>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "event2/event-config.h"
32 #include "evconfig-private.h"
33 
34 #include <sys/types.h>
35 
36 #ifdef EVENT__HAVE_SYS_TIME_H
37 #include <sys/time.h>
38 #endif
39 
40 #include <errno.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #ifdef EVENT__HAVE_STDARG_H
45 #include <stdarg.h>
46 #endif
47 #ifdef EVENT__HAVE_UNISTD_H
48 #include <unistd.h>
49 #endif
50 
51 #ifdef _WIN32
52 #include <winsock2.h>
53 #include <ws2tcpip.h>
54 #endif
55 
56 #ifdef EVENT__HAVE_SYS_SOCKET_H
57 #include <sys/socket.h>
58 #endif
59 #ifdef EVENT__HAVE_NETINET_IN_H
60 #include <netinet/in.h>
61 #endif
62 #ifdef EVENT__HAVE_NETINET_IN6_H
63 #include <netinet/in6.h>
64 #endif
65 
66 #include "event2/util.h"
67 #include "event2/bufferevent.h"
68 #include "event2/buffer.h"
69 #include "event2/bufferevent_struct.h"
70 #include "event2/bufferevent_compat.h"
71 #include "event2/event.h"
72 #include "log-internal.h"
73 #include "mm-internal.h"
74 #include "bufferevent-internal.h"
75 #include "util-internal.h"
76 #ifdef _WIN32
77 #include "iocp-internal.h"
78 #endif
79 
80 /* prototypes */
81 static int be_socket_enable(struct bufferevent *, short);
82 static int be_socket_disable(struct bufferevent *, short);
83 static void be_socket_destruct(struct bufferevent *);
84 static int be_socket_flush(struct bufferevent *, short, enum bufferevent_flush_mode);
85 static int be_socket_ctrl(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *);
86 
87 static void be_socket_setfd(struct bufferevent *, evutil_socket_t);
88 
89 const struct bufferevent_ops bufferevent_ops_socket = {
90 	"socket",
91 	evutil_offsetof(struct bufferevent_private, bev),
92 	be_socket_enable,
93 	be_socket_disable,
94 	NULL, /* unlink */
95 	be_socket_destruct,
96 	bufferevent_generic_adj_existing_timeouts_,
97 	be_socket_flush,
98 	be_socket_ctrl,
99 };
100 
101 const struct sockaddr*
102 bufferevent_socket_get_conn_address_(struct bufferevent *bev)
103 {
104 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
105 	return (struct sockaddr *)&bev_p->conn_address;
106 }
107 
108 void
109 bufferevent_socket_set_conn_address_fd_(struct bufferevent *bev,
110 	evutil_socket_t fd)
111 {
112 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
113 
114 	socklen_t len = sizeof(bev_p->conn_address);
115 
116 	struct sockaddr *addr = (struct sockaddr *)&bev_p->conn_address;
117 	if (addr->sa_family != AF_UNSPEC)
118 		getpeername(fd, addr, &len);
119 }
120 
121 void
122 bufferevent_socket_set_conn_address_(struct bufferevent *bev,
123 	struct sockaddr *addr, size_t addrlen)
124 {
125 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
126 	EVUTIL_ASSERT(addrlen <= sizeof(bev_p->conn_address));
127 	memcpy(&bev_p->conn_address, addr, addrlen);
128 }
129 
130 static void
131 bufferevent_socket_outbuf_cb(struct evbuffer *buf,
132     const struct evbuffer_cb_info *cbinfo,
133     void *arg)
134 {
135 	struct bufferevent *bufev = arg;
136 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
137 
138 	if (cbinfo->n_added &&
139 	    (bufev->enabled & EV_WRITE) &&
140 	    !event_pending(&bufev->ev_write, EV_WRITE, NULL) &&
141 	    !bufev_p->write_suspended) {
142 		/* Somebody added data to the buffer, and we would like to
143 		 * write, and we were not writing.  So, start writing. */
144 		if (bufferevent_add_event_(&bufev->ev_write, &bufev->timeout_write) == -1) {
145 		    /* Should we log this? */
146 		}
147 	}
148 }
149 
150 static void
151 bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
152 {
153 	struct bufferevent *bufev = arg;
154 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
155 	struct evbuffer *input;
156 	int res = 0;
157 	short what = BEV_EVENT_READING;
158 	ev_ssize_t howmuch = -1, readmax=-1;
159 
160 	bufferevent_incref_and_lock_(bufev);
161 
162 	if (event == EV_TIMEOUT) {
163 		/* Note that we only check for event==EV_TIMEOUT. If
164 		 * event==EV_TIMEOUT|EV_READ, we can safely ignore the
165 		 * timeout, since a read has occurred */
166 		what |= BEV_EVENT_TIMEOUT;
167 		goto error;
168 	}
169 
170 	input = bufev->input;
171 
172 	/*
173 	 * If we have a high watermark configured then we don't want to
174 	 * read more data than would make us reach the watermark.
175 	 */
176 	if (bufev->wm_read.high != 0) {
177 		howmuch = bufev->wm_read.high - evbuffer_get_length(input);
178 		/* we somehow lowered the watermark, stop reading */
179 		if (howmuch <= 0) {
180 			bufferevent_wm_suspend_read(bufev);
181 			goto done;
182 		}
183 	}
184 	readmax = bufferevent_get_read_max_(bufev_p);
185 	if (howmuch < 0 || howmuch > readmax) /* The use of -1 for "unlimited"
186 					       * uglifies this code. XXXX */
187 		howmuch = readmax;
188 	if (bufev_p->read_suspended)
189 		goto done;
190 
191 	evbuffer_unfreeze(input, 0);
192 	res = evbuffer_read(input, fd, (int)howmuch); /* XXXX evbuffer_read would do better to take and return ev_ssize_t */
193 	evbuffer_freeze(input, 0);
194 
195 	if (res == -1) {
196 		int err = evutil_socket_geterror(fd);
197 		if (EVUTIL_ERR_RW_RETRIABLE(err))
198 			goto reschedule;
199 		if (EVUTIL_ERR_CONNECT_REFUSED(err)) {
200 			bufev_p->connection_refused = 1;
201 			goto done;
202 		}
203 		/* error case */
204 		what |= BEV_EVENT_ERROR;
205 	} else if (res == 0) {
206 		/* eof case */
207 		what |= BEV_EVENT_EOF;
208 	}
209 
210 	if (res <= 0)
211 		goto error;
212 
213 	bufferevent_decrement_read_buckets_(bufev_p, res);
214 
215 	/* Invoke the user callback - must always be called last */
216 	bufferevent_trigger_nolock_(bufev, EV_READ, 0);
217 
218 	goto done;
219 
220  reschedule:
221 	goto done;
222 
223  error:
224 	bufferevent_disable(bufev, EV_READ);
225 	bufferevent_run_eventcb_(bufev, what, 0);
226 
227  done:
228 	bufferevent_decref_and_unlock_(bufev);
229 }
230 
231 static void
232 bufferevent_writecb(evutil_socket_t fd, short event, void *arg)
233 {
234 	struct bufferevent *bufev = arg;
235 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
236 	int res = 0;
237 	short what = BEV_EVENT_WRITING;
238 	int connected = 0;
239 	ev_ssize_t atmost = -1;
240 
241 	bufferevent_incref_and_lock_(bufev);
242 
243 	if (event == EV_TIMEOUT) {
244 		/* Note that we only check for event==EV_TIMEOUT. If
245 		 * event==EV_TIMEOUT|EV_WRITE, we can safely ignore the
246 		 * timeout, since a read has occurred */
247 		what |= BEV_EVENT_TIMEOUT;
248 		goto error;
249 	}
250 	if (bufev_p->connecting) {
251 		int c = evutil_socket_finished_connecting_(fd);
252 		/* we need to fake the error if the connection was refused
253 		 * immediately - usually connection to localhost on BSD */
254 		if (bufev_p->connection_refused) {
255 			bufev_p->connection_refused = 0;
256 			c = -1;
257 		}
258 
259 		if (c == 0)
260 			goto done;
261 
262 		bufev_p->connecting = 0;
263 		if (c < 0) {
264 			event_del(&bufev->ev_write);
265 			event_del(&bufev->ev_read);
266 			bufferevent_run_eventcb_(bufev, BEV_EVENT_ERROR, 0);
267 			goto done;
268 		} else {
269 			connected = 1;
270 			bufferevent_socket_set_conn_address_fd_(bufev, fd);
271 #ifdef _WIN32
272 			if (BEV_IS_ASYNC(bufev)) {
273 				event_del(&bufev->ev_write);
274 				bufferevent_async_set_connected_(bufev);
275 				bufferevent_run_eventcb_(bufev,
276 						BEV_EVENT_CONNECTED, 0);
277 				goto done;
278 			}
279 #endif
280 			bufferevent_run_eventcb_(bufev,
281 					BEV_EVENT_CONNECTED, 0);
282 			if (!(bufev->enabled & EV_WRITE) ||
283 			    bufev_p->write_suspended) {
284 				event_del(&bufev->ev_write);
285 				goto done;
286 			}
287 		}
288 	}
289 
290 	atmost = bufferevent_get_write_max_(bufev_p);
291 
292 	if (bufev_p->write_suspended)
293 		goto done;
294 
295 	if (evbuffer_get_length(bufev->output)) {
296 		evbuffer_unfreeze(bufev->output, 1);
297 		res = evbuffer_write_atmost(bufev->output, fd, atmost);
298 		evbuffer_freeze(bufev->output, 1);
299 		if (res == -1) {
300 			int err = evutil_socket_geterror(fd);
301 			if (EVUTIL_ERR_RW_RETRIABLE(err))
302 				goto reschedule;
303 			what |= BEV_EVENT_ERROR;
304 		} else if (res == 0) {
305 			/* eof case
306 			   XXXX Actually, a 0 on write doesn't indicate
307 			   an EOF. An ECONNRESET might be more typical.
308 			 */
309 			what |= BEV_EVENT_EOF;
310 		}
311 		if (res <= 0)
312 			goto error;
313 
314 		bufferevent_decrement_write_buckets_(bufev_p, res);
315 	}
316 
317 	if (evbuffer_get_length(bufev->output) == 0) {
318 		event_del(&bufev->ev_write);
319 	}
320 
321 	/*
322 	 * Invoke the user callback if our buffer is drained or below the
323 	 * low watermark.
324 	 */
325 	if (res || !connected) {
326 		bufferevent_trigger_nolock_(bufev, EV_WRITE, 0);
327 	}
328 
329 	goto done;
330 
331  reschedule:
332 	if (evbuffer_get_length(bufev->output) == 0) {
333 		event_del(&bufev->ev_write);
334 	}
335 	goto done;
336 
337  error:
338 	bufferevent_disable(bufev, EV_WRITE);
339 	bufferevent_run_eventcb_(bufev, what, 0);
340 
341  done:
342 	bufferevent_decref_and_unlock_(bufev);
343 }
344 
345 struct bufferevent *
346 bufferevent_socket_new(struct event_base *base, evutil_socket_t fd,
347     int options)
348 {
349 	struct bufferevent_private *bufev_p;
350 	struct bufferevent *bufev;
351 
352 #ifdef _WIN32
353 	if (base && event_base_get_iocp_(base))
354 		return bufferevent_async_new_(base, fd, options);
355 #endif
356 
357 	if ((bufev_p = mm_calloc(1, sizeof(struct bufferevent_private)))== NULL)
358 		return NULL;
359 
360 	if (bufferevent_init_common_(bufev_p, base, &bufferevent_ops_socket,
361 				    options) < 0) {
362 		mm_free(bufev_p);
363 		return NULL;
364 	}
365 	bufev = &bufev_p->bev;
366 	evbuffer_set_flags(bufev->output, EVBUFFER_FLAG_DRAINS_TO_FD);
367 
368 	event_assign(&bufev->ev_read, bufev->ev_base, fd,
369 	    EV_READ|EV_PERSIST|EV_FINALIZE, bufferevent_readcb, bufev);
370 	event_assign(&bufev->ev_write, bufev->ev_base, fd,
371 	    EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bufev);
372 
373 	evbuffer_add_cb(bufev->output, bufferevent_socket_outbuf_cb, bufev);
374 
375 	evbuffer_freeze(bufev->input, 0);
376 	evbuffer_freeze(bufev->output, 1);
377 
378 	return bufev;
379 }
380 
381 int
382 bufferevent_socket_connect(struct bufferevent *bev,
383     const struct sockaddr *sa, int socklen)
384 {
385 	struct bufferevent_private *bufev_p = BEV_UPCAST(bev);
386 
387 	evutil_socket_t fd;
388 	int r = 0;
389 	int result=-1;
390 	int ownfd = 0;
391 
392 	bufferevent_incref_and_lock_(bev);
393 
394 	fd = bufferevent_getfd(bev);
395 	if (fd < 0) {
396 		if (!sa)
397 			goto done;
398 		fd = evutil_socket_(sa->sa_family,
399 		    SOCK_STREAM|EVUTIL_SOCK_NONBLOCK, 0);
400 		if (fd < 0)
401 			goto freesock;
402 		ownfd = 1;
403 	}
404 	if (sa) {
405 #ifdef _WIN32
406 		if (bufferevent_async_can_connect_(bev)) {
407 			bufferevent_setfd(bev, fd);
408 			r = bufferevent_async_connect_(bev, fd, sa, socklen);
409 			if (r < 0)
410 				goto freesock;
411 			bufev_p->connecting = 1;
412 			result = 0;
413 			goto done;
414 		} else
415 #endif
416 		r = evutil_socket_connect_(&fd, sa, socklen);
417 		if (r < 0)
418 			goto freesock;
419 	}
420 #ifdef _WIN32
421 	/* ConnectEx() isn't always around, even when IOCP is enabled.
422 	 * Here, we borrow the socket object's write handler to fall back
423 	 * on a non-blocking connect() when ConnectEx() is unavailable. */
424 	if (BEV_IS_ASYNC(bev)) {
425 		event_assign(&bev->ev_write, bev->ev_base, fd,
426 		    EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bev);
427 	}
428 #endif
429 	bufferevent_setfd(bev, fd);
430 	if (r == 0) {
431 		if (! be_socket_enable(bev, EV_WRITE)) {
432 			bufev_p->connecting = 1;
433 			result = 0;
434 			goto done;
435 		}
436 	} else if (r == 1) {
437 		/* The connect succeeded already. How very BSD of it. */
438 		result = 0;
439 		bufev_p->connecting = 1;
440 		bufferevent_trigger_nolock_(bev, EV_WRITE, BEV_OPT_DEFER_CALLBACKS);
441 	} else {
442 		/* The connect failed already.  How very BSD of it. */
443 		result = 0;
444 		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, BEV_OPT_DEFER_CALLBACKS);
445 		bufferevent_disable(bev, EV_WRITE|EV_READ);
446 	}
447 
448 	goto done;
449 
450 freesock:
451 	if (ownfd)
452 		evutil_closesocket(fd);
453 done:
454 	bufferevent_decref_and_unlock_(bev);
455 	return result;
456 }
457 
458 static void
459 bufferevent_connect_getaddrinfo_cb(int result, struct evutil_addrinfo *ai,
460     void *arg)
461 {
462 	struct bufferevent *bev = arg;
463 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
464 	int r;
465 	BEV_LOCK(bev);
466 
467 	bufferevent_unsuspend_write_(bev, BEV_SUSPEND_LOOKUP);
468 	bufferevent_unsuspend_read_(bev, BEV_SUSPEND_LOOKUP);
469 
470 	bev_p->dns_request = NULL;
471 
472 	if (result == EVUTIL_EAI_CANCEL) {
473 		bev_p->dns_error = result;
474 		bufferevent_decref_and_unlock_(bev);
475 		return;
476 	}
477 	if (result != 0) {
478 		bev_p->dns_error = result;
479 		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
480 		bufferevent_decref_and_unlock_(bev);
481 		if (ai)
482 			evutil_freeaddrinfo(ai);
483 		return;
484 	}
485 
486 	/* XXX use the other addrinfos? */
487 	bufferevent_socket_set_conn_address_(bev, ai->ai_addr, (int)ai->ai_addrlen);
488 	r = bufferevent_socket_connect(bev, ai->ai_addr, (int)ai->ai_addrlen);
489 	if (r < 0)
490 		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
491 	bufferevent_decref_and_unlock_(bev);
492 	evutil_freeaddrinfo(ai);
493 }
494 
495 int
496 bufferevent_socket_connect_hostname(struct bufferevent *bev,
497     struct evdns_base *evdns_base, int family, const char *hostname, int port)
498 {
499 	char portbuf[10];
500 	struct evutil_addrinfo hint;
501 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
502 
503 	if (family != AF_INET && family != AF_INET6 && family != AF_UNSPEC)
504 		return -1;
505 	if (port < 1 || port > 65535)
506 		return -1;
507 
508 	memset(&hint, 0, sizeof(hint));
509 	hint.ai_family = family;
510 	hint.ai_protocol = IPPROTO_TCP;
511 	hint.ai_socktype = SOCK_STREAM;
512 
513 	evutil_snprintf(portbuf, sizeof(portbuf), "%d", port);
514 
515 	BEV_LOCK(bev);
516 	bev_p->dns_error = 0;
517 
518 	bufferevent_suspend_write_(bev, BEV_SUSPEND_LOOKUP);
519 	bufferevent_suspend_read_(bev, BEV_SUSPEND_LOOKUP);
520 
521 	bufferevent_incref_(bev);
522 	bev_p->dns_request = evutil_getaddrinfo_async_(evdns_base, hostname,
523 	    portbuf, &hint, bufferevent_connect_getaddrinfo_cb, bev);
524 	BEV_UNLOCK(bev);
525 
526 	return 0;
527 }
528 
529 int
530 bufferevent_socket_get_dns_error(struct bufferevent *bev)
531 {
532 	int rv;
533 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
534 
535 	BEV_LOCK(bev);
536 	rv = bev_p->dns_error;
537 	BEV_UNLOCK(bev);
538 
539 	return rv;
540 }
541 
542 /*
543  * Create a new buffered event object.
544  *
545  * The read callback is invoked whenever we read new data.
546  * The write callback is invoked whenever the output buffer is drained.
547  * The error callback is invoked on a write/read error or on EOF.
548  *
549  * Both read and write callbacks maybe NULL.  The error callback is not
550  * allowed to be NULL and have to be provided always.
551  */
552 
553 struct bufferevent *
554 bufferevent_new(evutil_socket_t fd,
555     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
556     bufferevent_event_cb eventcb, void *cbarg)
557 {
558 	struct bufferevent *bufev;
559 
560 	if (!(bufev = bufferevent_socket_new(NULL, fd, 0)))
561 		return NULL;
562 
563 	bufferevent_setcb(bufev, readcb, writecb, eventcb, cbarg);
564 
565 	return bufev;
566 }
567 
568 
569 static int
570 be_socket_enable(struct bufferevent *bufev, short event)
571 {
572 	if (event & EV_READ &&
573 	    bufferevent_add_event_(&bufev->ev_read, &bufev->timeout_read) == -1)
574 			return -1;
575 	if (event & EV_WRITE &&
576 	    bufferevent_add_event_(&bufev->ev_write, &bufev->timeout_write) == -1)
577 			return -1;
578 	return 0;
579 }
580 
581 static int
582 be_socket_disable(struct bufferevent *bufev, short event)
583 {
584 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
585 	if (event & EV_READ) {
586 		if (event_del(&bufev->ev_read) == -1)
587 			return -1;
588 	}
589 	/* Don't actually disable the write if we are trying to connect. */
590 	if ((event & EV_WRITE) && ! bufev_p->connecting) {
591 		if (event_del(&bufev->ev_write) == -1)
592 			return -1;
593 	}
594 	return 0;
595 }
596 
597 static void
598 be_socket_destruct(struct bufferevent *bufev)
599 {
600 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
601 	evutil_socket_t fd;
602 	EVUTIL_ASSERT(BEV_IS_SOCKET(bufev));
603 
604 	fd = event_get_fd(&bufev->ev_read);
605 
606 	if ((bufev_p->options & BEV_OPT_CLOSE_ON_FREE) && fd >= 0)
607 		EVUTIL_CLOSESOCKET(fd);
608 
609 	evutil_getaddrinfo_cancel_async_(bufev_p->dns_request);
610 }
611 
612 static int
613 be_socket_flush(struct bufferevent *bev, short iotype,
614     enum bufferevent_flush_mode mode)
615 {
616 	return 0;
617 }
618 
619 
620 static void
621 be_socket_setfd(struct bufferevent *bufev, evutil_socket_t fd)
622 {
623 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
624 
625 	BEV_LOCK(bufev);
626 	EVUTIL_ASSERT(BEV_IS_SOCKET(bufev));
627 
628 	event_del(&bufev->ev_read);
629 	event_del(&bufev->ev_write);
630 
631 	evbuffer_unfreeze(bufev->input, 0);
632 	evbuffer_unfreeze(bufev->output, 1);
633 
634 	event_assign(&bufev->ev_read, bufev->ev_base, fd,
635 	    EV_READ|EV_PERSIST|EV_FINALIZE, bufferevent_readcb, bufev);
636 	event_assign(&bufev->ev_write, bufev->ev_base, fd,
637 	    EV_WRITE|EV_PERSIST|EV_FINALIZE, bufferevent_writecb, bufev);
638 
639 	if (fd >= 0)
640 		bufferevent_enable(bufev, bufev->enabled);
641 
642 	evutil_getaddrinfo_cancel_async_(bufev_p->dns_request);
643 
644 	BEV_UNLOCK(bufev);
645 }
646 
647 /* XXXX Should non-socket bufferevents support this? */
648 int
649 bufferevent_priority_set(struct bufferevent *bufev, int priority)
650 {
651 	int r = -1;
652 	struct bufferevent_private *bufev_p = BEV_UPCAST(bufev);
653 
654 	BEV_LOCK(bufev);
655 	if (BEV_IS_ASYNC(bufev) || BEV_IS_FILTER(bufev) || BEV_IS_PAIR(bufev))
656 		goto done;
657 
658 	if (event_priority_set(&bufev->ev_read, priority) == -1)
659 		goto done;
660 	if (event_priority_set(&bufev->ev_write, priority) == -1)
661 		goto done;
662 
663 	event_deferred_cb_set_priority_(&bufev_p->deferred, priority);
664 
665 	r = 0;
666 done:
667 	BEV_UNLOCK(bufev);
668 	return r;
669 }
670 
671 /* XXXX Should non-socket bufferevents support this? */
672 int
673 bufferevent_base_set(struct event_base *base, struct bufferevent *bufev)
674 {
675 	int res = -1;
676 
677 	BEV_LOCK(bufev);
678 	if (!BEV_IS_SOCKET(bufev))
679 		goto done;
680 
681 	bufev->ev_base = base;
682 
683 	res = event_base_set(base, &bufev->ev_read);
684 	if (res == -1)
685 		goto done;
686 
687 	res = event_base_set(base, &bufev->ev_write);
688 done:
689 	BEV_UNLOCK(bufev);
690 	return res;
691 }
692 
693 static int
694 be_socket_ctrl(struct bufferevent *bev, enum bufferevent_ctrl_op op,
695     union bufferevent_ctrl_data *data)
696 {
697 	switch (op) {
698 	case BEV_CTRL_SET_FD:
699 		be_socket_setfd(bev, data->fd);
700 		return 0;
701 	case BEV_CTRL_GET_FD:
702 		data->fd = event_get_fd(&bev->ev_read);
703 		return 0;
704 	case BEV_CTRL_GET_UNDERLYING:
705 	case BEV_CTRL_CANCEL_ALL:
706 	default:
707 		return -1;
708 	}
709 }
710