1 /*
2  * Copyright (c) 2002-2007 Niels Provos <provos@citi.umich.edu>
3  * Copyright (c) 2007-2012 Niels Provos, Nick Mathewson
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include "event2/event-config.h"
29 #include "evconfig-private.h"
30 
31 #include <sys/types.h>
32 
33 #ifdef EVENT__HAVE_SYS_TIME_H
34 #include <sys/time.h>
35 #endif
36 
37 #include <errno.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #ifdef EVENT__HAVE_STDARG_H
42 #include <stdarg.h>
43 #endif
44 
45 #ifdef _WIN32
46 #include <winsock2.h>
47 #endif
48 
49 #include "event2/util.h"
50 #include "event2/buffer.h"
51 #include "event2/buffer_compat.h"
52 #include "event2/bufferevent.h"
53 #include "event2/bufferevent_struct.h"
54 #include "event2/bufferevent_compat.h"
55 #include "event2/event.h"
56 #include "event-internal.h"
57 #include "log-internal.h"
58 #include "mm-internal.h"
59 #include "bufferevent-internal.h"
60 #include "evbuffer-internal.h"
61 #include "util-internal.h"
62 
63 static void bufferevent_cancel_all_(struct bufferevent *bev);
64 static void bufferevent_finalize_cb_(struct event_callback *evcb, void *arg_);
65 
66 void
bufferevent_suspend_read_(struct bufferevent * bufev,bufferevent_suspend_flags what)67 bufferevent_suspend_read_(struct bufferevent *bufev, bufferevent_suspend_flags what)
68 {
69 	struct bufferevent_private *bufev_private =
70 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
71 	BEV_LOCK(bufev);
72 	if (!bufev_private->read_suspended)
73 		bufev->be_ops->disable(bufev, EV_READ);
74 	bufev_private->read_suspended |= what;
75 	BEV_UNLOCK(bufev);
76 }
77 
78 void
bufferevent_unsuspend_read_(struct bufferevent * bufev,bufferevent_suspend_flags what)79 bufferevent_unsuspend_read_(struct bufferevent *bufev, bufferevent_suspend_flags what)
80 {
81 	struct bufferevent_private *bufev_private =
82 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
83 	BEV_LOCK(bufev);
84 	bufev_private->read_suspended &= ~what;
85 	if (!bufev_private->read_suspended && (bufev->enabled & EV_READ))
86 		bufev->be_ops->enable(bufev, EV_READ);
87 	BEV_UNLOCK(bufev);
88 }
89 
90 void
bufferevent_suspend_write_(struct bufferevent * bufev,bufferevent_suspend_flags what)91 bufferevent_suspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
92 {
93 	struct bufferevent_private *bufev_private =
94 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
95 	BEV_LOCK(bufev);
96 	if (!bufev_private->write_suspended)
97 		bufev->be_ops->disable(bufev, EV_WRITE);
98 	bufev_private->write_suspended |= what;
99 	BEV_UNLOCK(bufev);
100 }
101 
102 void
bufferevent_unsuspend_write_(struct bufferevent * bufev,bufferevent_suspend_flags what)103 bufferevent_unsuspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
104 {
105 	struct bufferevent_private *bufev_private =
106 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
107 	BEV_LOCK(bufev);
108 	bufev_private->write_suspended &= ~what;
109 	if (!bufev_private->write_suspended && (bufev->enabled & EV_WRITE))
110 		bufev->be_ops->enable(bufev, EV_WRITE);
111 	BEV_UNLOCK(bufev);
112 }
113 
114 
115 /* Callback to implement watermarks on the input buffer.  Only enabled
116  * if the watermark is set. */
117 static void
bufferevent_inbuf_wm_cb(struct evbuffer * buf,const struct evbuffer_cb_info * cbinfo,void * arg)118 bufferevent_inbuf_wm_cb(struct evbuffer *buf,
119     const struct evbuffer_cb_info *cbinfo,
120     void *arg)
121 {
122 	struct bufferevent *bufev = arg;
123 	size_t size;
124 
125 	size = evbuffer_get_length(buf);
126 
127 	if (size >= bufev->wm_read.high)
128 		bufferevent_wm_suspend_read(bufev);
129 	else
130 		bufferevent_wm_unsuspend_read(bufev);
131 }
132 
133 static void
bufferevent_run_deferred_callbacks_locked(struct event_callback * cb,void * arg)134 bufferevent_run_deferred_callbacks_locked(struct event_callback *cb, void *arg)
135 {
136 	struct bufferevent_private *bufev_private = arg;
137 	struct bufferevent *bufev = &bufev_private->bev;
138 
139 	BEV_LOCK(bufev);
140 	if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
141 	    bufev->errorcb) {
142 		/* The "connected" happened before any reads or writes, so
143 		   send it first. */
144 		bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
145 		bufev->errorcb(bufev, BEV_EVENT_CONNECTED, bufev->cbarg);
146 	}
147 	if (bufev_private->readcb_pending && bufev->readcb) {
148 		bufev_private->readcb_pending = 0;
149 		bufev->readcb(bufev, bufev->cbarg);
150 	}
151 	if (bufev_private->writecb_pending && bufev->writecb) {
152 		bufev_private->writecb_pending = 0;
153 		bufev->writecb(bufev, bufev->cbarg);
154 	}
155 	if (bufev_private->eventcb_pending && bufev->errorcb) {
156 		short what = bufev_private->eventcb_pending;
157 		int err = bufev_private->errno_pending;
158 		bufev_private->eventcb_pending = 0;
159 		bufev_private->errno_pending = 0;
160 		EVUTIL_SET_SOCKET_ERROR(err);
161 		bufev->errorcb(bufev, what, bufev->cbarg);
162 	}
163 	bufferevent_decref_and_unlock_(bufev);
164 }
165 
166 static void
bufferevent_run_deferred_callbacks_unlocked(struct event_callback * cb,void * arg)167 bufferevent_run_deferred_callbacks_unlocked(struct event_callback *cb, void *arg)
168 {
169 	struct bufferevent_private *bufev_private = arg;
170 	struct bufferevent *bufev = &bufev_private->bev;
171 
172 	BEV_LOCK(bufev);
173 #define UNLOCKED(stmt) \
174 	do { BEV_UNLOCK(bufev); stmt; BEV_LOCK(bufev); } while(0)
175 
176 	if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
177 	    bufev->errorcb) {
178 		/* The "connected" happened before any reads or writes, so
179 		   send it first. */
180 		bufferevent_event_cb errorcb = bufev->errorcb;
181 		void *cbarg = bufev->cbarg;
182 		bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
183 		UNLOCKED(errorcb(bufev, BEV_EVENT_CONNECTED, cbarg));
184 	}
185 	if (bufev_private->readcb_pending && bufev->readcb) {
186 		bufferevent_data_cb readcb = bufev->readcb;
187 		void *cbarg = bufev->cbarg;
188 		bufev_private->readcb_pending = 0;
189 		UNLOCKED(readcb(bufev, cbarg));
190 	}
191 	if (bufev_private->writecb_pending && bufev->writecb) {
192 		bufferevent_data_cb writecb = bufev->writecb;
193 		void *cbarg = bufev->cbarg;
194 		bufev_private->writecb_pending = 0;
195 		UNLOCKED(writecb(bufev, cbarg));
196 	}
197 	if (bufev_private->eventcb_pending && bufev->errorcb) {
198 		bufferevent_event_cb errorcb = bufev->errorcb;
199 		void *cbarg = bufev->cbarg;
200 		short what = bufev_private->eventcb_pending;
201 		int err = bufev_private->errno_pending;
202 		bufev_private->eventcb_pending = 0;
203 		bufev_private->errno_pending = 0;
204 		EVUTIL_SET_SOCKET_ERROR(err);
205 		UNLOCKED(errorcb(bufev,what,cbarg));
206 	}
207 	bufferevent_decref_and_unlock_(bufev);
208 #undef UNLOCKED
209 }
210 
211 #define SCHEDULE_DEFERRED(bevp)						\
212 	do {								\
213 		if (event_deferred_cb_schedule_(			\
214 			    (bevp)->bev.ev_base,			\
215 			&(bevp)->deferred))				\
216 			bufferevent_incref_(&(bevp)->bev);		\
217 	} while (0)
218 
219 
220 void
bufferevent_run_readcb_(struct bufferevent * bufev,int options)221 bufferevent_run_readcb_(struct bufferevent *bufev, int options)
222 {
223 	/* Requires that we hold the lock and a reference */
224 	struct bufferevent_private *p =
225 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
226 	if (bufev->readcb == NULL)
227 		return;
228 	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
229 		p->readcb_pending = 1;
230 		SCHEDULE_DEFERRED(p);
231 	} else {
232 		bufev->readcb(bufev, bufev->cbarg);
233 	}
234 }
235 
236 void
bufferevent_run_writecb_(struct bufferevent * bufev,int options)237 bufferevent_run_writecb_(struct bufferevent *bufev, int options)
238 {
239 	/* Requires that we hold the lock and a reference */
240 	struct bufferevent_private *p =
241 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
242 	if (bufev->writecb == NULL)
243 		return;
244 	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
245 		p->writecb_pending = 1;
246 		SCHEDULE_DEFERRED(p);
247 	} else {
248 		bufev->writecb(bufev, bufev->cbarg);
249 	}
250 }
251 
252 #define BEV_TRIG_ALL_OPTS (			\
253 		BEV_TRIG_IGNORE_WATERMARKS|	\
254 		BEV_TRIG_DEFER_CALLBACKS	\
255 	)
256 
257 void
bufferevent_trigger(struct bufferevent * bufev,short iotype,int options)258 bufferevent_trigger(struct bufferevent *bufev, short iotype, int options)
259 {
260 	bufferevent_incref_and_lock_(bufev);
261 	bufferevent_trigger_nolock_(bufev, iotype, options&BEV_TRIG_ALL_OPTS);
262 	bufferevent_decref_and_unlock_(bufev);
263 }
264 
265 void
bufferevent_run_eventcb_(struct bufferevent * bufev,short what,int options)266 bufferevent_run_eventcb_(struct bufferevent *bufev, short what, int options)
267 {
268 	/* Requires that we hold the lock and a reference */
269 	struct bufferevent_private *p =
270 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
271 	if (bufev->errorcb == NULL)
272 		return;
273 	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
274 		p->eventcb_pending |= what;
275 		p->errno_pending = EVUTIL_SOCKET_ERROR();
276 		SCHEDULE_DEFERRED(p);
277 	} else {
278 		bufev->errorcb(bufev, what, bufev->cbarg);
279 	}
280 }
281 
282 void
bufferevent_trigger_event(struct bufferevent * bufev,short what,int options)283 bufferevent_trigger_event(struct bufferevent *bufev, short what, int options)
284 {
285 	bufferevent_incref_and_lock_(bufev);
286 	bufferevent_run_eventcb_(bufev, what, options&BEV_TRIG_ALL_OPTS);
287 	bufferevent_decref_and_unlock_(bufev);
288 }
289 
290 int
bufferevent_init_common_(struct bufferevent_private * bufev_private,struct event_base * base,const struct bufferevent_ops * ops,enum bufferevent_options options)291 bufferevent_init_common_(struct bufferevent_private *bufev_private,
292     struct event_base *base,
293     const struct bufferevent_ops *ops,
294     enum bufferevent_options options)
295 {
296 	struct bufferevent *bufev = &bufev_private->bev;
297 
298 	if (!bufev->input) {
299 		if ((bufev->input = evbuffer_new()) == NULL)
300 			return -1;
301 	}
302 
303 	if (!bufev->output) {
304 		if ((bufev->output = evbuffer_new()) == NULL) {
305 			evbuffer_free(bufev->input);
306 			return -1;
307 		}
308 	}
309 
310 	bufev_private->refcnt = 1;
311 	bufev->ev_base = base;
312 
313 	/* Disable timeouts. */
314 	evutil_timerclear(&bufev->timeout_read);
315 	evutil_timerclear(&bufev->timeout_write);
316 
317 	bufev->be_ops = ops;
318 
319 	bufferevent_ratelim_init_(bufev_private);
320 
321 	/*
322 	 * Set to EV_WRITE so that using bufferevent_write is going to
323 	 * trigger a callback.  Reading needs to be explicitly enabled
324 	 * because otherwise no data will be available.
325 	 */
326 	bufev->enabled = EV_WRITE;
327 
328 #ifndef EVENT__DISABLE_THREAD_SUPPORT
329 	if (options & BEV_OPT_THREADSAFE) {
330 		if (bufferevent_enable_locking_(bufev, NULL) < 0) {
331 			/* cleanup */
332 			evbuffer_free(bufev->input);
333 			evbuffer_free(bufev->output);
334 			bufev->input = NULL;
335 			bufev->output = NULL;
336 			return -1;
337 		}
338 	}
339 #endif
340 	if ((options & (BEV_OPT_DEFER_CALLBACKS|BEV_OPT_UNLOCK_CALLBACKS))
341 	    == BEV_OPT_UNLOCK_CALLBACKS) {
342 		event_warnx("UNLOCK_CALLBACKS requires DEFER_CALLBACKS");
343 		return -1;
344 	}
345 	if (options & BEV_OPT_UNLOCK_CALLBACKS)
346 		event_deferred_cb_init_(
347 		    &bufev_private->deferred,
348 		    event_base_get_npriorities(base) / 2,
349 		    bufferevent_run_deferred_callbacks_unlocked,
350 		    bufev_private);
351 	else
352 		event_deferred_cb_init_(
353 		    &bufev_private->deferred,
354 		    event_base_get_npriorities(base) / 2,
355 		    bufferevent_run_deferred_callbacks_locked,
356 		    bufev_private);
357 
358 	bufev_private->options = options;
359 
360 	evbuffer_set_parent_(bufev->input, bufev);
361 	evbuffer_set_parent_(bufev->output, bufev);
362 
363 	return 0;
364 }
365 
366 void
bufferevent_setcb(struct bufferevent * bufev,bufferevent_data_cb readcb,bufferevent_data_cb writecb,bufferevent_event_cb eventcb,void * cbarg)367 bufferevent_setcb(struct bufferevent *bufev,
368     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
369     bufferevent_event_cb eventcb, void *cbarg)
370 {
371 	BEV_LOCK(bufev);
372 
373 	bufev->readcb = readcb;
374 	bufev->writecb = writecb;
375 	bufev->errorcb = eventcb;
376 
377 	bufev->cbarg = cbarg;
378 	BEV_UNLOCK(bufev);
379 }
380 
381 void
bufferevent_getcb(struct bufferevent * bufev,bufferevent_data_cb * readcb_ptr,bufferevent_data_cb * writecb_ptr,bufferevent_event_cb * eventcb_ptr,void ** cbarg_ptr)382 bufferevent_getcb(struct bufferevent *bufev,
383     bufferevent_data_cb *readcb_ptr,
384     bufferevent_data_cb *writecb_ptr,
385     bufferevent_event_cb *eventcb_ptr,
386     void **cbarg_ptr)
387 {
388 	BEV_LOCK(bufev);
389 	if (readcb_ptr)
390 		*readcb_ptr = bufev->readcb;
391 	if (writecb_ptr)
392 		*writecb_ptr = bufev->writecb;
393 	if (eventcb_ptr)
394 		*eventcb_ptr = bufev->errorcb;
395 	if (cbarg_ptr)
396 		*cbarg_ptr = bufev->cbarg;
397 
398 	BEV_UNLOCK(bufev);
399 }
400 
401 struct evbuffer *
bufferevent_get_input(struct bufferevent * bufev)402 bufferevent_get_input(struct bufferevent *bufev)
403 {
404 	return bufev->input;
405 }
406 
407 struct evbuffer *
bufferevent_get_output(struct bufferevent * bufev)408 bufferevent_get_output(struct bufferevent *bufev)
409 {
410 	return bufev->output;
411 }
412 
413 struct event_base *
bufferevent_get_base(struct bufferevent * bufev)414 bufferevent_get_base(struct bufferevent *bufev)
415 {
416 	return bufev->ev_base;
417 }
418 
419 int
bufferevent_get_priority(const struct bufferevent * bufev)420 bufferevent_get_priority(const struct bufferevent *bufev)
421 {
422 	if (event_initialized(&bufev->ev_read)) {
423 		return event_get_priority(&bufev->ev_read);
424 	} else {
425 		return event_base_get_npriorities(bufev->ev_base) / 2;
426 	}
427 }
428 
429 int
bufferevent_write(struct bufferevent * bufev,const void * data,size_t size)430 bufferevent_write(struct bufferevent *bufev, const void *data, size_t size)
431 {
432 	if (evbuffer_add(bufev->output, data, size) == -1)
433 		return (-1);
434 
435 	return 0;
436 }
437 
438 int
bufferevent_write_buffer(struct bufferevent * bufev,struct evbuffer * buf)439 bufferevent_write_buffer(struct bufferevent *bufev, struct evbuffer *buf)
440 {
441 	if (evbuffer_add_buffer(bufev->output, buf) == -1)
442 		return (-1);
443 
444 	return 0;
445 }
446 
447 size_t
bufferevent_read(struct bufferevent * bufev,void * data,size_t size)448 bufferevent_read(struct bufferevent *bufev, void *data, size_t size)
449 {
450 	return (evbuffer_remove(bufev->input, data, size));
451 }
452 
453 int
bufferevent_read_buffer(struct bufferevent * bufev,struct evbuffer * buf)454 bufferevent_read_buffer(struct bufferevent *bufev, struct evbuffer *buf)
455 {
456 	return (evbuffer_add_buffer(buf, bufev->input));
457 }
458 
459 int
bufferevent_enable(struct bufferevent * bufev,short event)460 bufferevent_enable(struct bufferevent *bufev, short event)
461 {
462 	struct bufferevent_private *bufev_private =
463 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
464 	short impl_events = event;
465 	int r = 0;
466 
467 	bufferevent_incref_and_lock_(bufev);
468 	if (bufev_private->read_suspended)
469 		impl_events &= ~EV_READ;
470 	if (bufev_private->write_suspended)
471 		impl_events &= ~EV_WRITE;
472 
473 	bufev->enabled |= event;
474 
475 	if (impl_events && bufev->be_ops->enable(bufev, impl_events) < 0)
476 		r = -1;
477 
478 	bufferevent_decref_and_unlock_(bufev);
479 	return r;
480 }
481 
482 int
bufferevent_set_timeouts(struct bufferevent * bufev,const struct timeval * tv_read,const struct timeval * tv_write)483 bufferevent_set_timeouts(struct bufferevent *bufev,
484 			 const struct timeval *tv_read,
485 			 const struct timeval *tv_write)
486 {
487 	int r = 0;
488 	BEV_LOCK(bufev);
489 	if (tv_read) {
490 		bufev->timeout_read = *tv_read;
491 	} else {
492 		evutil_timerclear(&bufev->timeout_read);
493 	}
494 	if (tv_write) {
495 		bufev->timeout_write = *tv_write;
496 	} else {
497 		evutil_timerclear(&bufev->timeout_write);
498 	}
499 
500 	if (bufev->be_ops->adj_timeouts)
501 		r = bufev->be_ops->adj_timeouts(bufev);
502 	BEV_UNLOCK(bufev);
503 
504 	return r;
505 }
506 
507 
508 /* Obsolete; use bufferevent_set_timeouts */
509 void
bufferevent_settimeout(struct bufferevent * bufev,int timeout_read,int timeout_write)510 bufferevent_settimeout(struct bufferevent *bufev,
511 		       int timeout_read, int timeout_write)
512 {
513 	struct timeval tv_read, tv_write;
514 	struct timeval *ptv_read = NULL, *ptv_write = NULL;
515 
516 	memset(&tv_read, 0, sizeof(tv_read));
517 	memset(&tv_write, 0, sizeof(tv_write));
518 
519 	if (timeout_read) {
520 		tv_read.tv_sec = timeout_read;
521 		ptv_read = &tv_read;
522 	}
523 	if (timeout_write) {
524 		tv_write.tv_sec = timeout_write;
525 		ptv_write = &tv_write;
526 	}
527 
528 	bufferevent_set_timeouts(bufev, ptv_read, ptv_write);
529 }
530 
531 
532 int
bufferevent_disable_hard_(struct bufferevent * bufev,short event)533 bufferevent_disable_hard_(struct bufferevent *bufev, short event)
534 {
535 	int r = 0;
536 	struct bufferevent_private *bufev_private =
537 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
538 
539 	BEV_LOCK(bufev);
540 	bufev->enabled &= ~event;
541 
542 	bufev_private->connecting = 0;
543 	if (bufev->be_ops->disable(bufev, event) < 0)
544 		r = -1;
545 
546 	BEV_UNLOCK(bufev);
547 	return r;
548 }
549 
550 int
bufferevent_disable(struct bufferevent * bufev,short event)551 bufferevent_disable(struct bufferevent *bufev, short event)
552 {
553 	int r = 0;
554 
555 	BEV_LOCK(bufev);
556 	bufev->enabled &= ~event;
557 
558 	if (bufev->be_ops->disable(bufev, event) < 0)
559 		r = -1;
560 
561 	BEV_UNLOCK(bufev);
562 	return r;
563 }
564 
565 /*
566  * Sets the water marks
567  */
568 
569 void
bufferevent_setwatermark(struct bufferevent * bufev,short events,size_t lowmark,size_t highmark)570 bufferevent_setwatermark(struct bufferevent *bufev, short events,
571     size_t lowmark, size_t highmark)
572 {
573 	struct bufferevent_private *bufev_private =
574 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
575 
576 	BEV_LOCK(bufev);
577 	if (events & EV_WRITE) {
578 		bufev->wm_write.low = lowmark;
579 		bufev->wm_write.high = highmark;
580 	}
581 
582 	if (events & EV_READ) {
583 		bufev->wm_read.low = lowmark;
584 		bufev->wm_read.high = highmark;
585 
586 		if (highmark) {
587 			/* There is now a new high-water mark for read.
588 			   enable the callback if needed, and see if we should
589 			   suspend/bufferevent_wm_unsuspend. */
590 
591 			if (bufev_private->read_watermarks_cb == NULL) {
592 				bufev_private->read_watermarks_cb =
593 				    evbuffer_add_cb(bufev->input,
594 						    bufferevent_inbuf_wm_cb,
595 						    bufev);
596 			}
597 			evbuffer_cb_set_flags(bufev->input,
598 				      bufev_private->read_watermarks_cb,
599 				      EVBUFFER_CB_ENABLED|EVBUFFER_CB_NODEFER);
600 
601 			if (evbuffer_get_length(bufev->input) >= highmark)
602 				bufferevent_wm_suspend_read(bufev);
603 			else if (evbuffer_get_length(bufev->input) < highmark)
604 				bufferevent_wm_unsuspend_read(bufev);
605 		} else {
606 			/* There is now no high-water mark for read. */
607 			if (bufev_private->read_watermarks_cb)
608 				evbuffer_cb_clear_flags(bufev->input,
609 				    bufev_private->read_watermarks_cb,
610 				    EVBUFFER_CB_ENABLED);
611 			bufferevent_wm_unsuspend_read(bufev);
612 		}
613 	}
614 	BEV_UNLOCK(bufev);
615 }
616 
617 int
bufferevent_getwatermark(struct bufferevent * bufev,short events,size_t * lowmark,size_t * highmark)618 bufferevent_getwatermark(struct bufferevent *bufev, short events,
619     size_t *lowmark, size_t *highmark)
620 {
621 	if (events == EV_WRITE) {
622 		BEV_LOCK(bufev);
623 		if (lowmark)
624 			*lowmark = bufev->wm_write.low;
625 		if (highmark)
626 			*highmark = bufev->wm_write.high;
627 		BEV_UNLOCK(bufev);
628 		return 0;
629 	}
630 
631 	if (events == EV_READ) {
632 		BEV_LOCK(bufev);
633 		if (lowmark)
634 			*lowmark = bufev->wm_read.low;
635 		if (highmark)
636 			*highmark = bufev->wm_read.high;
637 		BEV_UNLOCK(bufev);
638 		return 0;
639 	}
640 	return -1;
641 }
642 
643 int
bufferevent_flush(struct bufferevent * bufev,short iotype,enum bufferevent_flush_mode mode)644 bufferevent_flush(struct bufferevent *bufev,
645     short iotype,
646     enum bufferevent_flush_mode mode)
647 {
648 	int r = -1;
649 	BEV_LOCK(bufev);
650 	if (bufev->be_ops->flush)
651 		r = bufev->be_ops->flush(bufev, iotype, mode);
652 	BEV_UNLOCK(bufev);
653 	return r;
654 }
655 
656 void
bufferevent_incref_and_lock_(struct bufferevent * bufev)657 bufferevent_incref_and_lock_(struct bufferevent *bufev)
658 {
659 	struct bufferevent_private *bufev_private =
660 	    BEV_UPCAST(bufev);
661 	BEV_LOCK(bufev);
662 	++bufev_private->refcnt;
663 }
664 
665 #if 0
666 static void
667 bufferevent_transfer_lock_ownership_(struct bufferevent *donor,
668     struct bufferevent *recipient)
669 {
670 	struct bufferevent_private *d = BEV_UPCAST(donor);
671 	struct bufferevent_private *r = BEV_UPCAST(recipient);
672 	if (d->lock != r->lock)
673 		return;
674 	if (r->own_lock)
675 		return;
676 	if (d->own_lock) {
677 		d->own_lock = 0;
678 		r->own_lock = 1;
679 	}
680 }
681 #endif
682 
683 int
bufferevent_decref_and_unlock_(struct bufferevent * bufev)684 bufferevent_decref_and_unlock_(struct bufferevent *bufev)
685 {
686 	struct bufferevent_private *bufev_private =
687 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
688 	int n_cbs = 0;
689 #define MAX_CBS 16
690 	struct event_callback *cbs[MAX_CBS];
691 
692 	EVUTIL_ASSERT(bufev_private->refcnt > 0);
693 
694 	if (--bufev_private->refcnt) {
695 		BEV_UNLOCK(bufev);
696 		return 0;
697 	}
698 
699 	if (bufev->be_ops->unlink)
700 		bufev->be_ops->unlink(bufev);
701 
702 	/* Okay, we're out of references. Let's finalize this once all the
703 	 * callbacks are done running. */
704 	cbs[0] = &bufev->ev_read.ev_evcallback;
705 	cbs[1] = &bufev->ev_write.ev_evcallback;
706 	cbs[2] = &bufev_private->deferred;
707 	n_cbs = 3;
708 	if (bufev_private->rate_limiting) {
709 		struct event *e = &bufev_private->rate_limiting->refill_bucket_event;
710 		if (event_initialized(e))
711 			cbs[n_cbs++] = &e->ev_evcallback;
712 	}
713 	n_cbs += evbuffer_get_callbacks_(bufev->input, cbs+n_cbs, MAX_CBS-n_cbs);
714 	n_cbs += evbuffer_get_callbacks_(bufev->output, cbs+n_cbs, MAX_CBS-n_cbs);
715 
716 	event_callback_finalize_many_(bufev->ev_base, n_cbs, cbs,
717 	    bufferevent_finalize_cb_);
718 
719 #undef MAX_CBS
720 	BEV_UNLOCK(bufev);
721 
722 	return 1;
723 }
724 
725 static void
bufferevent_finalize_cb_(struct event_callback * evcb,void * arg_)726 bufferevent_finalize_cb_(struct event_callback *evcb, void *arg_)
727 {
728 	struct bufferevent *bufev = arg_;
729 	struct bufferevent *underlying;
730 	struct bufferevent_private *bufev_private =
731 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
732 
733 	BEV_LOCK(bufev);
734 	underlying = bufferevent_get_underlying(bufev);
735 
736 	/* Clean up the shared info */
737 	if (bufev->be_ops->destruct)
738 		bufev->be_ops->destruct(bufev);
739 
740 	/* XXX what happens if refcnt for these buffers is > 1?
741 	 * The buffers can share a lock with this bufferevent object,
742 	 * but the lock might be destroyed below. */
743 	/* evbuffer will free the callbacks */
744 	evbuffer_free(bufev->input);
745 	evbuffer_free(bufev->output);
746 
747 	if (bufev_private->rate_limiting) {
748 		if (bufev_private->rate_limiting->group)
749 			bufferevent_remove_from_rate_limit_group_internal_(bufev,0);
750 		mm_free(bufev_private->rate_limiting);
751 		bufev_private->rate_limiting = NULL;
752 	}
753 
754 
755 	BEV_UNLOCK(bufev);
756 
757 	if (bufev_private->own_lock)
758 		EVTHREAD_FREE_LOCK(bufev_private->lock,
759 		    EVTHREAD_LOCKTYPE_RECURSIVE);
760 
761 	/* Free the actual allocated memory. */
762 	mm_free(((char*)bufev) - bufev->be_ops->mem_offset);
763 
764 	/* Release the reference to underlying now that we no longer need the
765 	 * reference to it.  We wait this long mainly in case our lock is
766 	 * shared with underlying.
767 	 *
768 	 * The 'destruct' function will also drop a reference to underlying
769 	 * if BEV_OPT_CLOSE_ON_FREE is set.
770 	 *
771 	 * XXX Should we/can we just refcount evbuffer/bufferevent locks?
772 	 * It would probably save us some headaches.
773 	 */
774 	if (underlying)
775 		bufferevent_decref_(underlying);
776 }
777 
778 int
bufferevent_decref(struct bufferevent * bufev)779 bufferevent_decref(struct bufferevent *bufev)
780 {
781 	BEV_LOCK(bufev);
782 	return bufferevent_decref_and_unlock_(bufev);
783 }
784 
785 void
bufferevent_free(struct bufferevent * bufev)786 bufferevent_free(struct bufferevent *bufev)
787 {
788 	BEV_LOCK(bufev);
789 	bufferevent_setcb(bufev, NULL, NULL, NULL, NULL);
790 	bufferevent_cancel_all_(bufev);
791 	bufferevent_decref_and_unlock_(bufev);
792 }
793 
794 void
bufferevent_incref(struct bufferevent * bufev)795 bufferevent_incref(struct bufferevent *bufev)
796 {
797 	struct bufferevent_private *bufev_private =
798 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
799 
800 	/* XXX: now that this function is public, we might want to
801 	 * - return the count from this function
802 	 * - create a new function to atomically grab the current refcount
803 	 */
804 	BEV_LOCK(bufev);
805 	++bufev_private->refcnt;
806 	BEV_UNLOCK(bufev);
807 }
808 
809 int
bufferevent_enable_locking_(struct bufferevent * bufev,void * lock)810 bufferevent_enable_locking_(struct bufferevent *bufev, void *lock)
811 {
812 #ifdef EVENT__DISABLE_THREAD_SUPPORT
813 	return -1;
814 #else
815 	struct bufferevent *underlying;
816 
817 	if (BEV_UPCAST(bufev)->lock)
818 		return -1;
819 	underlying = bufferevent_get_underlying(bufev);
820 
821 	if (!lock && underlying && BEV_UPCAST(underlying)->lock) {
822 		lock = BEV_UPCAST(underlying)->lock;
823 		BEV_UPCAST(bufev)->lock = lock;
824 		BEV_UPCAST(bufev)->own_lock = 0;
825 	} else if (!lock) {
826 		EVTHREAD_ALLOC_LOCK(lock, EVTHREAD_LOCKTYPE_RECURSIVE);
827 		if (!lock)
828 			return -1;
829 		BEV_UPCAST(bufev)->lock = lock;
830 		BEV_UPCAST(bufev)->own_lock = 1;
831 	} else {
832 		BEV_UPCAST(bufev)->lock = lock;
833 		BEV_UPCAST(bufev)->own_lock = 0;
834 	}
835 	evbuffer_enable_locking(bufev->input, lock);
836 	evbuffer_enable_locking(bufev->output, lock);
837 
838 	if (underlying && !BEV_UPCAST(underlying)->lock)
839 		bufferevent_enable_locking_(underlying, lock);
840 
841 	return 0;
842 #endif
843 }
844 
845 int
bufferevent_setfd(struct bufferevent * bev,evutil_socket_t fd)846 bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
847 {
848 	union bufferevent_ctrl_data d;
849 	int res = -1;
850 	d.fd = fd;
851 	BEV_LOCK(bev);
852 	if (bev->be_ops->ctrl)
853 		res = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
854 	BEV_UNLOCK(bev);
855 	return res;
856 }
857 
858 evutil_socket_t
bufferevent_getfd(struct bufferevent * bev)859 bufferevent_getfd(struct bufferevent *bev)
860 {
861 	union bufferevent_ctrl_data d;
862 	int res = -1;
863 	d.fd = -1;
864 	BEV_LOCK(bev);
865 	if (bev->be_ops->ctrl)
866 		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
867 	BEV_UNLOCK(bev);
868 	return (res<0) ? -1 : d.fd;
869 }
870 
871 enum bufferevent_options
bufferevent_get_options_(struct bufferevent * bev)872 bufferevent_get_options_(struct bufferevent *bev)
873 {
874 	struct bufferevent_private *bev_p =
875 	    EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
876 	enum bufferevent_options options;
877 
878 	BEV_LOCK(bev);
879 	options = bev_p->options;
880 	BEV_UNLOCK(bev);
881 	return options;
882 }
883 
884 
885 static void
bufferevent_cancel_all_(struct bufferevent * bev)886 bufferevent_cancel_all_(struct bufferevent *bev)
887 {
888 	union bufferevent_ctrl_data d;
889 	memset(&d, 0, sizeof(d));
890 	BEV_LOCK(bev);
891 	if (bev->be_ops->ctrl)
892 		bev->be_ops->ctrl(bev, BEV_CTRL_CANCEL_ALL, &d);
893 	BEV_UNLOCK(bev);
894 }
895 
896 short
bufferevent_get_enabled(struct bufferevent * bufev)897 bufferevent_get_enabled(struct bufferevent *bufev)
898 {
899 	short r;
900 	BEV_LOCK(bufev);
901 	r = bufev->enabled;
902 	BEV_UNLOCK(bufev);
903 	return r;
904 }
905 
906 struct bufferevent *
bufferevent_get_underlying(struct bufferevent * bev)907 bufferevent_get_underlying(struct bufferevent *bev)
908 {
909 	union bufferevent_ctrl_data d;
910 	int res = -1;
911 	d.ptr = NULL;
912 	BEV_LOCK(bev);
913 	if (bev->be_ops->ctrl)
914 		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_UNDERLYING, &d);
915 	BEV_UNLOCK(bev);
916 	return (res<0) ? NULL : d.ptr;
917 }
918 
919 static void
bufferevent_generic_read_timeout_cb(evutil_socket_t fd,short event,void * ctx)920 bufferevent_generic_read_timeout_cb(evutil_socket_t fd, short event, void *ctx)
921 {
922 	struct bufferevent *bev = ctx;
923 	bufferevent_incref_and_lock_(bev);
924 	bufferevent_disable(bev, EV_READ);
925 	bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_READING, 0);
926 	bufferevent_decref_and_unlock_(bev);
927 }
928 static void
bufferevent_generic_write_timeout_cb(evutil_socket_t fd,short event,void * ctx)929 bufferevent_generic_write_timeout_cb(evutil_socket_t fd, short event, void *ctx)
930 {
931 	struct bufferevent *bev = ctx;
932 	bufferevent_incref_and_lock_(bev);
933 	bufferevent_disable(bev, EV_WRITE);
934 	bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_WRITING, 0);
935 	bufferevent_decref_and_unlock_(bev);
936 }
937 
938 void
bufferevent_init_generic_timeout_cbs_(struct bufferevent * bev)939 bufferevent_init_generic_timeout_cbs_(struct bufferevent *bev)
940 {
941 	event_assign(&bev->ev_read, bev->ev_base, -1, EV_FINALIZE,
942 	    bufferevent_generic_read_timeout_cb, bev);
943 	event_assign(&bev->ev_write, bev->ev_base, -1, EV_FINALIZE,
944 	    bufferevent_generic_write_timeout_cb, bev);
945 }
946 
947 int
bufferevent_generic_adj_timeouts_(struct bufferevent * bev)948 bufferevent_generic_adj_timeouts_(struct bufferevent *bev)
949 {
950 	const short enabled = bev->enabled;
951 	struct bufferevent_private *bev_p =
952 	    EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
953 	int r1=0, r2=0;
954 	if ((enabled & EV_READ) && !bev_p->read_suspended &&
955 	    evutil_timerisset(&bev->timeout_read))
956 		r1 = event_add(&bev->ev_read, &bev->timeout_read);
957 	else
958 		r1 = event_del(&bev->ev_read);
959 
960 	if ((enabled & EV_WRITE) && !bev_p->write_suspended &&
961 	    evutil_timerisset(&bev->timeout_write) &&
962 	    evbuffer_get_length(bev->output))
963 		r2 = event_add(&bev->ev_write, &bev->timeout_write);
964 	else
965 		r2 = event_del(&bev->ev_write);
966 	if (r1 < 0 || r2 < 0)
967 		return -1;
968 	return 0;
969 }
970 
971 int
bufferevent_generic_adj_existing_timeouts_(struct bufferevent * bev)972 bufferevent_generic_adj_existing_timeouts_(struct bufferevent *bev)
973 {
974 	int r = 0;
975 	if (event_pending(&bev->ev_read, EV_READ, NULL)) {
976 		if (evutil_timerisset(&bev->timeout_read)) {
977 			    if (bufferevent_add_event_(&bev->ev_read, &bev->timeout_read) < 0)
978 				    r = -1;
979 		} else {
980 			event_remove_timer(&bev->ev_read);
981 		}
982 	}
983 	if (event_pending(&bev->ev_write, EV_WRITE, NULL)) {
984 		if (evutil_timerisset(&bev->timeout_write)) {
985 			if (bufferevent_add_event_(&bev->ev_write, &bev->timeout_write) < 0)
986 				r = -1;
987 		} else {
988 			event_remove_timer(&bev->ev_write);
989 		}
990 	}
991 	return r;
992 }
993 
994 int
bufferevent_add_event_(struct event * ev,const struct timeval * tv)995 bufferevent_add_event_(struct event *ev, const struct timeval *tv)
996 {
997 	if (!evutil_timerisset(tv))
998 		return event_add(ev, NULL);
999 	else
1000 		return event_add(ev, tv);
1001 }
1002 
1003 /* For use by user programs only; internally, we should be calling
1004    either bufferevent_incref_and_lock_(), or BEV_LOCK. */
1005 void
bufferevent_lock(struct bufferevent * bev)1006 bufferevent_lock(struct bufferevent *bev)
1007 {
1008 	bufferevent_incref_and_lock_(bev);
1009 }
1010 
1011 void
bufferevent_unlock(struct bufferevent * bev)1012 bufferevent_unlock(struct bufferevent *bev)
1013 {
1014 	bufferevent_decref_and_unlock_(bev);
1015 }
1016