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 = BEV_UPCAST(bufev);
70 	BEV_LOCK(bufev);
71 	if (!bufev_private->read_suspended)
72 		bufev->be_ops->disable(bufev, EV_READ);
73 	bufev_private->read_suspended |= what;
74 	BEV_UNLOCK(bufev);
75 }
76 
77 void
bufferevent_unsuspend_read_(struct bufferevent * bufev,bufferevent_suspend_flags what)78 bufferevent_unsuspend_read_(struct bufferevent *bufev, bufferevent_suspend_flags what)
79 {
80 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
81 	BEV_LOCK(bufev);
82 	bufev_private->read_suspended &= ~what;
83 	if (!bufev_private->read_suspended && (bufev->enabled & EV_READ))
84 		bufev->be_ops->enable(bufev, EV_READ);
85 	BEV_UNLOCK(bufev);
86 }
87 
88 void
bufferevent_suspend_write_(struct bufferevent * bufev,bufferevent_suspend_flags what)89 bufferevent_suspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
90 {
91 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
92 	BEV_LOCK(bufev);
93 	if (!bufev_private->write_suspended)
94 		bufev->be_ops->disable(bufev, EV_WRITE);
95 	bufev_private->write_suspended |= what;
96 	BEV_UNLOCK(bufev);
97 }
98 
99 void
bufferevent_unsuspend_write_(struct bufferevent * bufev,bufferevent_suspend_flags what)100 bufferevent_unsuspend_write_(struct bufferevent *bufev, bufferevent_suspend_flags what)
101 {
102 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
103 	BEV_LOCK(bufev);
104 	bufev_private->write_suspended &= ~what;
105 	if (!bufev_private->write_suspended && (bufev->enabled & EV_WRITE))
106 		bufev->be_ops->enable(bufev, EV_WRITE);
107 	BEV_UNLOCK(bufev);
108 }
109 
110 /**
111  * Sometimes bufferevent's implementation can overrun high watermarks
112  * (one of examples is openssl) and in this case if the read callback
113  * will not handle enough data do over condition above the read
114  * callback will never be called again (due to suspend above).
115  *
116  * To avoid this we are scheduling read callback again here, but only
117  * from the user callback to avoid multiple scheduling:
118  * - when the data had been added to it
119  * - when the data had been drained from it (user specified read callback)
120  */
bufferevent_inbuf_wm_check(struct bufferevent * bev)121 static void bufferevent_inbuf_wm_check(struct bufferevent *bev)
122 {
123 	if (!bev->wm_read.high)
124 		return;
125 	if (!(bev->enabled & EV_READ))
126 		return;
127 	if (evbuffer_get_length(bev->input) < bev->wm_read.high)
128 		return;
129 
130 	bufferevent_trigger(bev, EV_READ, BEV_OPT_DEFER_CALLBACKS);
131 }
132 
133 /* Callback to implement watermarks on the input buffer.  Only enabled
134  * if the watermark is set. */
135 static void
bufferevent_inbuf_wm_cb(struct evbuffer * buf,const struct evbuffer_cb_info * cbinfo,void * arg)136 bufferevent_inbuf_wm_cb(struct evbuffer *buf,
137     const struct evbuffer_cb_info *cbinfo,
138     void *arg)
139 {
140 	struct bufferevent *bufev = arg;
141 	size_t size;
142 
143 	size = evbuffer_get_length(buf);
144 
145 	if (size >= bufev->wm_read.high)
146 		bufferevent_wm_suspend_read(bufev);
147 	else
148 		bufferevent_wm_unsuspend_read(bufev);
149 }
150 
151 static void
bufferevent_run_deferred_callbacks_locked(struct event_callback * cb,void * arg)152 bufferevent_run_deferred_callbacks_locked(struct event_callback *cb, void *arg)
153 {
154 	struct bufferevent_private *bufev_private = arg;
155 	struct bufferevent *bufev = &bufev_private->bev;
156 
157 	BEV_LOCK(bufev);
158 	if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
159 	    bufev->errorcb) {
160 		/* The "connected" happened before any reads or writes, so
161 		   send it first. */
162 		bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
163 		bufev->errorcb(bufev, BEV_EVENT_CONNECTED, bufev->cbarg);
164 	}
165 	if (bufev_private->readcb_pending && bufev->readcb) {
166 		bufev_private->readcb_pending = 0;
167 		bufev->readcb(bufev, bufev->cbarg);
168 		bufferevent_inbuf_wm_check(bufev);
169 	}
170 	if (bufev_private->writecb_pending && bufev->writecb) {
171 		bufev_private->writecb_pending = 0;
172 		bufev->writecb(bufev, bufev->cbarg);
173 	}
174 	if (bufev_private->eventcb_pending && bufev->errorcb) {
175 		short what = bufev_private->eventcb_pending;
176 		int err = bufev_private->errno_pending;
177 		bufev_private->eventcb_pending = 0;
178 		bufev_private->errno_pending = 0;
179 		EVUTIL_SET_SOCKET_ERROR(err);
180 		bufev->errorcb(bufev, what, bufev->cbarg);
181 	}
182 	bufferevent_decref_and_unlock_(bufev);
183 }
184 
185 static void
bufferevent_run_deferred_callbacks_unlocked(struct event_callback * cb,void * arg)186 bufferevent_run_deferred_callbacks_unlocked(struct event_callback *cb, void *arg)
187 {
188 	struct bufferevent_private *bufev_private = arg;
189 	struct bufferevent *bufev = &bufev_private->bev;
190 
191 	BEV_LOCK(bufev);
192 #define UNLOCKED(stmt) \
193 	do { BEV_UNLOCK(bufev); stmt; BEV_LOCK(bufev); } while(0)
194 
195 	if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
196 	    bufev->errorcb) {
197 		/* The "connected" happened before any reads or writes, so
198 		   send it first. */
199 		bufferevent_event_cb errorcb = bufev->errorcb;
200 		void *cbarg = bufev->cbarg;
201 		bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
202 		UNLOCKED(errorcb(bufev, BEV_EVENT_CONNECTED, cbarg));
203 	}
204 	if (bufev_private->readcb_pending && bufev->readcb) {
205 		bufferevent_data_cb readcb = bufev->readcb;
206 		void *cbarg = bufev->cbarg;
207 		bufev_private->readcb_pending = 0;
208 		UNLOCKED(readcb(bufev, cbarg));
209 		bufferevent_inbuf_wm_check(bufev);
210 	}
211 	if (bufev_private->writecb_pending && bufev->writecb) {
212 		bufferevent_data_cb writecb = bufev->writecb;
213 		void *cbarg = bufev->cbarg;
214 		bufev_private->writecb_pending = 0;
215 		UNLOCKED(writecb(bufev, cbarg));
216 	}
217 	if (bufev_private->eventcb_pending && bufev->errorcb) {
218 		bufferevent_event_cb errorcb = bufev->errorcb;
219 		void *cbarg = bufev->cbarg;
220 		short what = bufev_private->eventcb_pending;
221 		int err = bufev_private->errno_pending;
222 		bufev_private->eventcb_pending = 0;
223 		bufev_private->errno_pending = 0;
224 		EVUTIL_SET_SOCKET_ERROR(err);
225 		UNLOCKED(errorcb(bufev,what,cbarg));
226 	}
227 	bufferevent_decref_and_unlock_(bufev);
228 #undef UNLOCKED
229 }
230 
231 #define SCHEDULE_DEFERRED(bevp)						\
232 	do {								\
233 		if (event_deferred_cb_schedule_(			\
234 			    (bevp)->bev.ev_base,			\
235 			&(bevp)->deferred))				\
236 			bufferevent_incref_(&(bevp)->bev);		\
237 	} while (0)
238 
239 
240 void
bufferevent_run_readcb_(struct bufferevent * bufev,int options)241 bufferevent_run_readcb_(struct bufferevent *bufev, int options)
242 {
243 	/* Requires that we hold the lock and a reference */
244 	struct bufferevent_private *p = BEV_UPCAST(bufev);
245 	if (bufev->readcb == NULL)
246 		return;
247 	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
248 		p->readcb_pending = 1;
249 		SCHEDULE_DEFERRED(p);
250 	} else {
251 		bufev->readcb(bufev, bufev->cbarg);
252 		bufferevent_inbuf_wm_check(bufev);
253 	}
254 }
255 
256 void
bufferevent_run_writecb_(struct bufferevent * bufev,int options)257 bufferevent_run_writecb_(struct bufferevent *bufev, int options)
258 {
259 	/* Requires that we hold the lock and a reference */
260 	struct bufferevent_private *p = BEV_UPCAST(bufev);
261 	if (bufev->writecb == NULL)
262 		return;
263 	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
264 		p->writecb_pending = 1;
265 		SCHEDULE_DEFERRED(p);
266 	} else {
267 		bufev->writecb(bufev, bufev->cbarg);
268 	}
269 }
270 
271 #define BEV_TRIG_ALL_OPTS (			\
272 		BEV_TRIG_IGNORE_WATERMARKS|	\
273 		BEV_TRIG_DEFER_CALLBACKS	\
274 	)
275 
276 void
bufferevent_trigger(struct bufferevent * bufev,short iotype,int options)277 bufferevent_trigger(struct bufferevent *bufev, short iotype, int options)
278 {
279 	bufferevent_incref_and_lock_(bufev);
280 	bufferevent_trigger_nolock_(bufev, iotype, options&BEV_TRIG_ALL_OPTS);
281 	bufferevent_decref_and_unlock_(bufev);
282 }
283 
284 void
bufferevent_run_eventcb_(struct bufferevent * bufev,short what,int options)285 bufferevent_run_eventcb_(struct bufferevent *bufev, short what, int options)
286 {
287 	/* Requires that we hold the lock and a reference */
288 	struct bufferevent_private *p = BEV_UPCAST(bufev);
289 	if (bufev->errorcb == NULL)
290 		return;
291 	if ((p->options|options) & BEV_OPT_DEFER_CALLBACKS) {
292 		p->eventcb_pending |= what;
293 		p->errno_pending = EVUTIL_SOCKET_ERROR();
294 		SCHEDULE_DEFERRED(p);
295 	} else {
296 		bufev->errorcb(bufev, what, bufev->cbarg);
297 	}
298 }
299 
300 void
bufferevent_trigger_event(struct bufferevent * bufev,short what,int options)301 bufferevent_trigger_event(struct bufferevent *bufev, short what, int options)
302 {
303 	bufferevent_incref_and_lock_(bufev);
304 	bufferevent_run_eventcb_(bufev, what, options&BEV_TRIG_ALL_OPTS);
305 	bufferevent_decref_and_unlock_(bufev);
306 }
307 
308 int
bufferevent_init_common_(struct bufferevent_private * bufev_private,struct event_base * base,const struct bufferevent_ops * ops,enum bufferevent_options options)309 bufferevent_init_common_(struct bufferevent_private *bufev_private,
310     struct event_base *base,
311     const struct bufferevent_ops *ops,
312     enum bufferevent_options options)
313 {
314 	struct bufferevent *bufev = &bufev_private->bev;
315 
316 	if (!bufev->input) {
317 		if ((bufev->input = evbuffer_new()) == NULL)
318 			goto err;
319 	}
320 
321 	if (!bufev->output) {
322 		if ((bufev->output = evbuffer_new()) == NULL)
323 			goto err;
324 	}
325 
326 	bufev_private->refcnt = 1;
327 	bufev->ev_base = base;
328 
329 	/* Disable timeouts. */
330 	evutil_timerclear(&bufev->timeout_read);
331 	evutil_timerclear(&bufev->timeout_write);
332 
333 	bufev->be_ops = ops;
334 
335 	if (bufferevent_ratelim_init_(bufev_private))
336 		goto err;
337 
338 	/*
339 	 * Set to EV_WRITE so that using bufferevent_write is going to
340 	 * trigger a callback.  Reading needs to be explicitly enabled
341 	 * because otherwise no data will be available.
342 	 */
343 	bufev->enabled = EV_WRITE;
344 
345 #ifndef EVENT__DISABLE_THREAD_SUPPORT
346 	if (options & BEV_OPT_THREADSAFE) {
347 		if (bufferevent_enable_locking_(bufev, NULL) < 0)
348 			goto err;
349 	}
350 #endif
351 	if ((options & (BEV_OPT_DEFER_CALLBACKS|BEV_OPT_UNLOCK_CALLBACKS))
352 	    == BEV_OPT_UNLOCK_CALLBACKS) {
353 		event_warnx("UNLOCK_CALLBACKS requires DEFER_CALLBACKS");
354 		goto err;
355 	}
356 	if (options & BEV_OPT_UNLOCK_CALLBACKS)
357 		event_deferred_cb_init_(
358 		    &bufev_private->deferred,
359 		    event_base_get_npriorities(base) / 2,
360 		    bufferevent_run_deferred_callbacks_unlocked,
361 		    bufev_private);
362 	else
363 		event_deferred_cb_init_(
364 		    &bufev_private->deferred,
365 		    event_base_get_npriorities(base) / 2,
366 		    bufferevent_run_deferred_callbacks_locked,
367 		    bufev_private);
368 
369 	bufev_private->options = options;
370 
371 	evbuffer_set_parent_(bufev->input, bufev);
372 	evbuffer_set_parent_(bufev->output, bufev);
373 
374 	return 0;
375 
376 err:
377 	if (bufev->input) {
378 		evbuffer_free(bufev->input);
379 		bufev->input = NULL;
380 	}
381 	if (bufev->output) {
382 		evbuffer_free(bufev->output);
383 		bufev->output = NULL;
384 	}
385 	return -1;
386 }
387 
388 void
bufferevent_setcb(struct bufferevent * bufev,bufferevent_data_cb readcb,bufferevent_data_cb writecb,bufferevent_event_cb eventcb,void * cbarg)389 bufferevent_setcb(struct bufferevent *bufev,
390     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
391     bufferevent_event_cb eventcb, void *cbarg)
392 {
393 	BEV_LOCK(bufev);
394 
395 	bufev->readcb = readcb;
396 	bufev->writecb = writecb;
397 	bufev->errorcb = eventcb;
398 
399 	bufev->cbarg = cbarg;
400 	BEV_UNLOCK(bufev);
401 }
402 
403 void
bufferevent_getcb(struct bufferevent * bufev,bufferevent_data_cb * readcb_ptr,bufferevent_data_cb * writecb_ptr,bufferevent_event_cb * eventcb_ptr,void ** cbarg_ptr)404 bufferevent_getcb(struct bufferevent *bufev,
405     bufferevent_data_cb *readcb_ptr,
406     bufferevent_data_cb *writecb_ptr,
407     bufferevent_event_cb *eventcb_ptr,
408     void **cbarg_ptr)
409 {
410 	BEV_LOCK(bufev);
411 	if (readcb_ptr)
412 		*readcb_ptr = bufev->readcb;
413 	if (writecb_ptr)
414 		*writecb_ptr = bufev->writecb;
415 	if (eventcb_ptr)
416 		*eventcb_ptr = bufev->errorcb;
417 	if (cbarg_ptr)
418 		*cbarg_ptr = bufev->cbarg;
419 
420 	BEV_UNLOCK(bufev);
421 }
422 
423 struct evbuffer *
bufferevent_get_input(struct bufferevent * bufev)424 bufferevent_get_input(struct bufferevent *bufev)
425 {
426 	return bufev->input;
427 }
428 
429 struct evbuffer *
bufferevent_get_output(struct bufferevent * bufev)430 bufferevent_get_output(struct bufferevent *bufev)
431 {
432 	return bufev->output;
433 }
434 
435 struct event_base *
bufferevent_get_base(struct bufferevent * bufev)436 bufferevent_get_base(struct bufferevent *bufev)
437 {
438 	return bufev->ev_base;
439 }
440 
441 int
bufferevent_get_priority(const struct bufferevent * bufev)442 bufferevent_get_priority(const struct bufferevent *bufev)
443 {
444 	if (event_initialized(&bufev->ev_read)) {
445 		return event_get_priority(&bufev->ev_read);
446 	} else {
447 		return event_base_get_npriorities(bufev->ev_base) / 2;
448 	}
449 }
450 
451 int
bufferevent_write(struct bufferevent * bufev,const void * data,size_t size)452 bufferevent_write(struct bufferevent *bufev, const void *data, size_t size)
453 {
454 	if (evbuffer_add(bufev->output, data, size) == -1)
455 		return (-1);
456 
457 	return 0;
458 }
459 
460 int
bufferevent_write_buffer(struct bufferevent * bufev,struct evbuffer * buf)461 bufferevent_write_buffer(struct bufferevent *bufev, struct evbuffer *buf)
462 {
463 	if (evbuffer_add_buffer(bufev->output, buf) == -1)
464 		return (-1);
465 
466 	return 0;
467 }
468 
469 size_t
bufferevent_read(struct bufferevent * bufev,void * data,size_t size)470 bufferevent_read(struct bufferevent *bufev, void *data, size_t size)
471 {
472 	return (evbuffer_remove(bufev->input, data, size));
473 }
474 
475 int
bufferevent_read_buffer(struct bufferevent * bufev,struct evbuffer * buf)476 bufferevent_read_buffer(struct bufferevent *bufev, struct evbuffer *buf)
477 {
478 	return (evbuffer_add_buffer(buf, bufev->input));
479 }
480 
481 int
bufferevent_enable(struct bufferevent * bufev,short event)482 bufferevent_enable(struct bufferevent *bufev, short event)
483 {
484 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
485 	short impl_events = event;
486 	int r = 0;
487 
488 	bufferevent_incref_and_lock_(bufev);
489 	if (bufev_private->read_suspended)
490 		impl_events &= ~EV_READ;
491 	if (bufev_private->write_suspended)
492 		impl_events &= ~EV_WRITE;
493 
494 	bufev->enabled |= event;
495 
496 	if (impl_events && bufev->be_ops->enable(bufev, impl_events) < 0)
497 		r = -1;
498 	if (r)
499 		event_debug(("%s: cannot enable 0x%hx on %p", __func__, event, bufev));
500 
501 	bufferevent_decref_and_unlock_(bufev);
502 	return r;
503 }
504 
505 int
bufferevent_set_timeouts(struct bufferevent * bufev,const struct timeval * tv_read,const struct timeval * tv_write)506 bufferevent_set_timeouts(struct bufferevent *bufev,
507 			 const struct timeval *tv_read,
508 			 const struct timeval *tv_write)
509 {
510 	int r = 0;
511 	BEV_LOCK(bufev);
512 	if (tv_read) {
513 		bufev->timeout_read = *tv_read;
514 	} else {
515 		evutil_timerclear(&bufev->timeout_read);
516 	}
517 	if (tv_write) {
518 		bufev->timeout_write = *tv_write;
519 	} else {
520 		evutil_timerclear(&bufev->timeout_write);
521 	}
522 
523 	if (bufev->be_ops->adj_timeouts)
524 		r = bufev->be_ops->adj_timeouts(bufev);
525 	BEV_UNLOCK(bufev);
526 
527 	return r;
528 }
529 
530 
531 /* Obsolete; use bufferevent_set_timeouts */
532 void
bufferevent_settimeout(struct bufferevent * bufev,int timeout_read,int timeout_write)533 bufferevent_settimeout(struct bufferevent *bufev,
534 		       int timeout_read, int timeout_write)
535 {
536 	struct timeval tv_read, tv_write;
537 	struct timeval *ptv_read = NULL, *ptv_write = NULL;
538 
539 	memset(&tv_read, 0, sizeof(tv_read));
540 	memset(&tv_write, 0, sizeof(tv_write));
541 
542 	if (timeout_read) {
543 		tv_read.tv_sec = timeout_read;
544 		ptv_read = &tv_read;
545 	}
546 	if (timeout_write) {
547 		tv_write.tv_sec = timeout_write;
548 		ptv_write = &tv_write;
549 	}
550 
551 	bufferevent_set_timeouts(bufev, ptv_read, ptv_write);
552 }
553 
554 
555 int
bufferevent_disable_hard_(struct bufferevent * bufev,short event)556 bufferevent_disable_hard_(struct bufferevent *bufev, short event)
557 {
558 	int r = 0;
559 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
560 
561 	BEV_LOCK(bufev);
562 	bufev->enabled &= ~event;
563 
564 	bufev_private->connecting = 0;
565 	if (bufev->be_ops->disable(bufev, event) < 0)
566 		r = -1;
567 
568 	BEV_UNLOCK(bufev);
569 	return r;
570 }
571 
572 int
bufferevent_disable(struct bufferevent * bufev,short event)573 bufferevent_disable(struct bufferevent *bufev, short event)
574 {
575 	int r = 0;
576 
577 	BEV_LOCK(bufev);
578 	bufev->enabled &= ~event;
579 
580 	if (bufev->be_ops->disable(bufev, event) < 0)
581 		r = -1;
582 	if (r)
583 		event_debug(("%s: cannot disable 0x%hx on %p", __func__, event, bufev));
584 
585 	BEV_UNLOCK(bufev);
586 	return r;
587 }
588 
589 /*
590  * Sets the water marks
591  */
592 
593 void
bufferevent_setwatermark(struct bufferevent * bufev,short events,size_t lowmark,size_t highmark)594 bufferevent_setwatermark(struct bufferevent *bufev, short events,
595     size_t lowmark, size_t highmark)
596 {
597 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
598 
599 	BEV_LOCK(bufev);
600 	if (events & EV_WRITE) {
601 		bufev->wm_write.low = lowmark;
602 		bufev->wm_write.high = highmark;
603 	}
604 
605 	if (events & EV_READ) {
606 		bufev->wm_read.low = lowmark;
607 		bufev->wm_read.high = highmark;
608 
609 		if (highmark) {
610 			/* There is now a new high-water mark for read.
611 			   enable the callback if needed, and see if we should
612 			   suspend/bufferevent_wm_unsuspend. */
613 
614 			if (bufev_private->read_watermarks_cb == NULL) {
615 				bufev_private->read_watermarks_cb =
616 				    evbuffer_add_cb(bufev->input,
617 						    bufferevent_inbuf_wm_cb,
618 						    bufev);
619 			}
620 			evbuffer_cb_set_flags(bufev->input,
621 				      bufev_private->read_watermarks_cb,
622 				      EVBUFFER_CB_ENABLED|EVBUFFER_CB_NODEFER);
623 
624 			if (evbuffer_get_length(bufev->input) >= highmark)
625 				bufferevent_wm_suspend_read(bufev);
626 			else if (evbuffer_get_length(bufev->input) < highmark)
627 				bufferevent_wm_unsuspend_read(bufev);
628 		} else {
629 			/* There is now no high-water mark for read. */
630 			if (bufev_private->read_watermarks_cb)
631 				evbuffer_cb_clear_flags(bufev->input,
632 				    bufev_private->read_watermarks_cb,
633 				    EVBUFFER_CB_ENABLED);
634 			bufferevent_wm_unsuspend_read(bufev);
635 		}
636 	}
637 	BEV_UNLOCK(bufev);
638 }
639 
640 int
bufferevent_getwatermark(struct bufferevent * bufev,short events,size_t * lowmark,size_t * highmark)641 bufferevent_getwatermark(struct bufferevent *bufev, short events,
642     size_t *lowmark, size_t *highmark)
643 {
644 	if (events == EV_WRITE) {
645 		BEV_LOCK(bufev);
646 		if (lowmark)
647 			*lowmark = bufev->wm_write.low;
648 		if (highmark)
649 			*highmark = bufev->wm_write.high;
650 		BEV_UNLOCK(bufev);
651 		return 0;
652 	}
653 
654 	if (events == EV_READ) {
655 		BEV_LOCK(bufev);
656 		if (lowmark)
657 			*lowmark = bufev->wm_read.low;
658 		if (highmark)
659 			*highmark = bufev->wm_read.high;
660 		BEV_UNLOCK(bufev);
661 		return 0;
662 	}
663 	return -1;
664 }
665 
666 int
bufferevent_flush(struct bufferevent * bufev,short iotype,enum bufferevent_flush_mode mode)667 bufferevent_flush(struct bufferevent *bufev,
668     short iotype,
669     enum bufferevent_flush_mode mode)
670 {
671 	int r = -1;
672 	BEV_LOCK(bufev);
673 	if (bufev->be_ops->flush)
674 		r = bufev->be_ops->flush(bufev, iotype, mode);
675 	BEV_UNLOCK(bufev);
676 	return r;
677 }
678 
679 void
bufferevent_incref_and_lock_(struct bufferevent * bufev)680 bufferevent_incref_and_lock_(struct bufferevent *bufev)
681 {
682 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
683 	BEV_LOCK(bufev);
684 	++bufev_private->refcnt;
685 }
686 
687 #if 0
688 static void
689 bufferevent_transfer_lock_ownership_(struct bufferevent *donor,
690     struct bufferevent *recipient)
691 {
692 	struct bufferevent_private *d = BEV_UPCAST(donor);
693 	struct bufferevent_private *r = BEV_UPCAST(recipient);
694 	if (d->lock != r->lock)
695 		return;
696 	if (r->own_lock)
697 		return;
698 	if (d->own_lock) {
699 		d->own_lock = 0;
700 		r->own_lock = 1;
701 	}
702 }
703 #endif
704 
705 int
bufferevent_decref_and_unlock_(struct bufferevent * bufev)706 bufferevent_decref_and_unlock_(struct bufferevent *bufev)
707 {
708 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
709 	int n_cbs = 0;
710 #define MAX_CBS 16
711 	struct event_callback *cbs[MAX_CBS];
712 
713 	EVUTIL_ASSERT(bufev_private->refcnt > 0);
714 
715 	if (--bufev_private->refcnt) {
716 		BEV_UNLOCK(bufev);
717 		return 0;
718 	}
719 
720 	if (bufev->be_ops->unlink)
721 		bufev->be_ops->unlink(bufev);
722 
723 	/* Okay, we're out of references. Let's finalize this once all the
724 	 * callbacks are done running. */
725 	cbs[0] = &bufev->ev_read.ev_evcallback;
726 	cbs[1] = &bufev->ev_write.ev_evcallback;
727 	cbs[2] = &bufev_private->deferred;
728 	n_cbs = 3;
729 	if (bufev_private->rate_limiting) {
730 		struct event *e = &bufev_private->rate_limiting->refill_bucket_event;
731 		if (event_initialized(e))
732 			cbs[n_cbs++] = &e->ev_evcallback;
733 	}
734 	n_cbs += evbuffer_get_callbacks_(bufev->input, cbs+n_cbs, MAX_CBS-n_cbs);
735 	n_cbs += evbuffer_get_callbacks_(bufev->output, cbs+n_cbs, MAX_CBS-n_cbs);
736 
737 	event_callback_finalize_many_(bufev->ev_base, n_cbs, cbs,
738 	    bufferevent_finalize_cb_);
739 
740 #undef MAX_CBS
741 	BEV_UNLOCK(bufev);
742 
743 	return 1;
744 }
745 
746 static void
bufferevent_finalize_cb_(struct event_callback * evcb,void * arg_)747 bufferevent_finalize_cb_(struct event_callback *evcb, void *arg_)
748 {
749 	struct bufferevent *bufev = arg_;
750 	struct bufferevent *underlying;
751 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
752 
753 	BEV_LOCK(bufev);
754 	underlying = bufferevent_get_underlying(bufev);
755 
756 	/* Clean up the shared info */
757 	if (bufev->be_ops->destruct)
758 		bufev->be_ops->destruct(bufev);
759 
760 	/* XXX what happens if refcnt for these buffers is > 1?
761 	 * The buffers can share a lock with this bufferevent object,
762 	 * but the lock might be destroyed below. */
763 	/* evbuffer will free the callbacks */
764 	evbuffer_free(bufev->input);
765 	evbuffer_free(bufev->output);
766 
767 	if (bufev_private->rate_limiting) {
768 		if (bufev_private->rate_limiting->group)
769 			bufferevent_remove_from_rate_limit_group_internal_(bufev,0);
770 		mm_free(bufev_private->rate_limiting);
771 		bufev_private->rate_limiting = NULL;
772 	}
773 
774 
775 	BEV_UNLOCK(bufev);
776 
777 	if (bufev_private->own_lock)
778 		EVTHREAD_FREE_LOCK(bufev_private->lock,
779 		    EVTHREAD_LOCKTYPE_RECURSIVE);
780 
781 	/* Free the actual allocated memory. */
782 	mm_free(((char*)bufev) - bufev->be_ops->mem_offset);
783 
784 	/* Release the reference to underlying now that we no longer need the
785 	 * reference to it.  We wait this long mainly in case our lock is
786 	 * shared with underlying.
787 	 *
788 	 * The 'destruct' function will also drop a reference to underlying
789 	 * if BEV_OPT_CLOSE_ON_FREE is set.
790 	 *
791 	 * XXX Should we/can we just refcount evbuffer/bufferevent locks?
792 	 * It would probably save us some headaches.
793 	 */
794 	if (underlying)
795 		bufferevent_decref_(underlying);
796 }
797 
798 int
bufferevent_decref(struct bufferevent * bufev)799 bufferevent_decref(struct bufferevent *bufev)
800 {
801 	BEV_LOCK(bufev);
802 	return bufferevent_decref_and_unlock_(bufev);
803 }
804 
805 void
bufferevent_free(struct bufferevent * bufev)806 bufferevent_free(struct bufferevent *bufev)
807 {
808 	BEV_LOCK(bufev);
809 	bufferevent_setcb(bufev, NULL, NULL, NULL, NULL);
810 	bufferevent_cancel_all_(bufev);
811 	bufferevent_decref_and_unlock_(bufev);
812 }
813 
814 void
bufferevent_incref(struct bufferevent * bufev)815 bufferevent_incref(struct bufferevent *bufev)
816 {
817 	struct bufferevent_private *bufev_private = BEV_UPCAST(bufev);
818 
819 	/* XXX: now that this function is public, we might want to
820 	 * - return the count from this function
821 	 * - create a new function to atomically grab the current refcount
822 	 */
823 	BEV_LOCK(bufev);
824 	++bufev_private->refcnt;
825 	BEV_UNLOCK(bufev);
826 }
827 
828 int
bufferevent_enable_locking_(struct bufferevent * bufev,void * lock)829 bufferevent_enable_locking_(struct bufferevent *bufev, void *lock)
830 {
831 #ifdef EVENT__DISABLE_THREAD_SUPPORT
832 	return -1;
833 #else
834 	struct bufferevent *underlying;
835 
836 	if (BEV_UPCAST(bufev)->lock)
837 		return -1;
838 	underlying = bufferevent_get_underlying(bufev);
839 
840 	if (!lock && underlying && BEV_UPCAST(underlying)->lock) {
841 		lock = BEV_UPCAST(underlying)->lock;
842 		BEV_UPCAST(bufev)->lock = lock;
843 		BEV_UPCAST(bufev)->own_lock = 0;
844 	} else if (!lock) {
845 		EVTHREAD_ALLOC_LOCK(lock, EVTHREAD_LOCKTYPE_RECURSIVE);
846 		if (!lock)
847 			return -1;
848 		BEV_UPCAST(bufev)->lock = lock;
849 		BEV_UPCAST(bufev)->own_lock = 1;
850 	} else {
851 		BEV_UPCAST(bufev)->lock = lock;
852 		BEV_UPCAST(bufev)->own_lock = 0;
853 	}
854 	evbuffer_enable_locking(bufev->input, lock);
855 	evbuffer_enable_locking(bufev->output, lock);
856 
857 	if (underlying && !BEV_UPCAST(underlying)->lock)
858 		bufferevent_enable_locking_(underlying, lock);
859 
860 	return 0;
861 #endif
862 }
863 
864 int
bufferevent_setfd(struct bufferevent * bev,evutil_socket_t fd)865 bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
866 {
867 	union bufferevent_ctrl_data d;
868 	int res = -1;
869 	d.fd = fd;
870 	BEV_LOCK(bev);
871 	if (bev->be_ops->ctrl)
872 		res = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
873 	if (res)
874 		event_debug(("%s: cannot set fd for %p to "EV_SOCK_FMT, __func__, bev, fd));
875 	BEV_UNLOCK(bev);
876 	return res;
877 }
878 
879 evutil_socket_t
bufferevent_getfd(struct bufferevent * bev)880 bufferevent_getfd(struct bufferevent *bev)
881 {
882 	union bufferevent_ctrl_data d;
883 	int res = -1;
884 	d.fd = -1;
885 	BEV_LOCK(bev);
886 	if (bev->be_ops->ctrl)
887 		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
888 	if (res)
889 		event_debug(("%s: cannot get fd for %p", __func__, bev));
890 	BEV_UNLOCK(bev);
891 	return (res<0) ? -1 : d.fd;
892 }
893 
894 enum bufferevent_options
bufferevent_get_options_(struct bufferevent * bev)895 bufferevent_get_options_(struct bufferevent *bev)
896 {
897 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
898 	enum bufferevent_options options;
899 
900 	BEV_LOCK(bev);
901 	options = bev_p->options;
902 	BEV_UNLOCK(bev);
903 	return options;
904 }
905 
906 
907 static void
bufferevent_cancel_all_(struct bufferevent * bev)908 bufferevent_cancel_all_(struct bufferevent *bev)
909 {
910 	union bufferevent_ctrl_data d;
911 	memset(&d, 0, sizeof(d));
912 	BEV_LOCK(bev);
913 	if (bev->be_ops->ctrl)
914 		bev->be_ops->ctrl(bev, BEV_CTRL_CANCEL_ALL, &d);
915 	BEV_UNLOCK(bev);
916 }
917 
918 short
bufferevent_get_enabled(struct bufferevent * bufev)919 bufferevent_get_enabled(struct bufferevent *bufev)
920 {
921 	short r;
922 	BEV_LOCK(bufev);
923 	r = bufev->enabled;
924 	BEV_UNLOCK(bufev);
925 	return r;
926 }
927 
928 struct bufferevent *
bufferevent_get_underlying(struct bufferevent * bev)929 bufferevent_get_underlying(struct bufferevent *bev)
930 {
931 	union bufferevent_ctrl_data d;
932 	int res = -1;
933 	d.ptr = NULL;
934 	BEV_LOCK(bev);
935 	if (bev->be_ops->ctrl)
936 		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_UNDERLYING, &d);
937 	BEV_UNLOCK(bev);
938 	return (res<0) ? NULL : d.ptr;
939 }
940 
941 static void
bufferevent_generic_read_timeout_cb(evutil_socket_t fd,short event,void * ctx)942 bufferevent_generic_read_timeout_cb(evutil_socket_t fd, short event, void *ctx)
943 {
944 	struct bufferevent *bev = ctx;
945 	bufferevent_incref_and_lock_(bev);
946 	bufferevent_disable(bev, EV_READ);
947 	bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_READING, 0);
948 	bufferevent_decref_and_unlock_(bev);
949 }
950 static void
bufferevent_generic_write_timeout_cb(evutil_socket_t fd,short event,void * ctx)951 bufferevent_generic_write_timeout_cb(evutil_socket_t fd, short event, void *ctx)
952 {
953 	struct bufferevent *bev = ctx;
954 	bufferevent_incref_and_lock_(bev);
955 	bufferevent_disable(bev, EV_WRITE);
956 	bufferevent_run_eventcb_(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_WRITING, 0);
957 	bufferevent_decref_and_unlock_(bev);
958 }
959 
960 void
bufferevent_init_generic_timeout_cbs_(struct bufferevent * bev)961 bufferevent_init_generic_timeout_cbs_(struct bufferevent *bev)
962 {
963 	event_assign(&bev->ev_read, bev->ev_base, -1, EV_FINALIZE,
964 	    bufferevent_generic_read_timeout_cb, bev);
965 	event_assign(&bev->ev_write, bev->ev_base, -1, EV_FINALIZE,
966 	    bufferevent_generic_write_timeout_cb, bev);
967 }
968 
969 int
bufferevent_generic_adj_timeouts_(struct bufferevent * bev)970 bufferevent_generic_adj_timeouts_(struct bufferevent *bev)
971 {
972 	const short enabled = bev->enabled;
973 	struct bufferevent_private *bev_p = BEV_UPCAST(bev);
974 	int r1=0, r2=0;
975 	if ((enabled & EV_READ) && !bev_p->read_suspended &&
976 	    evutil_timerisset(&bev->timeout_read))
977 		r1 = event_add(&bev->ev_read, &bev->timeout_read);
978 	else
979 		r1 = event_del(&bev->ev_read);
980 
981 	if ((enabled & EV_WRITE) && !bev_p->write_suspended &&
982 	    evutil_timerisset(&bev->timeout_write) &&
983 	    evbuffer_get_length(bev->output))
984 		r2 = event_add(&bev->ev_write, &bev->timeout_write);
985 	else
986 		r2 = event_del(&bev->ev_write);
987 	if (r1 < 0 || r2 < 0)
988 		return -1;
989 	return 0;
990 }
991 
992 int
bufferevent_generic_adj_existing_timeouts_(struct bufferevent * bev)993 bufferevent_generic_adj_existing_timeouts_(struct bufferevent *bev)
994 {
995 	int r = 0;
996 	if (event_pending(&bev->ev_read, EV_READ, NULL)) {
997 		if (evutil_timerisset(&bev->timeout_read)) {
998 			    if (bufferevent_add_event_(&bev->ev_read, &bev->timeout_read) < 0)
999 				    r = -1;
1000 		} else {
1001 			event_remove_timer(&bev->ev_read);
1002 		}
1003 	}
1004 	if (event_pending(&bev->ev_write, EV_WRITE, NULL)) {
1005 		if (evutil_timerisset(&bev->timeout_write)) {
1006 			if (bufferevent_add_event_(&bev->ev_write, &bev->timeout_write) < 0)
1007 				r = -1;
1008 		} else {
1009 			event_remove_timer(&bev->ev_write);
1010 		}
1011 	}
1012 	return r;
1013 }
1014 
1015 int
bufferevent_add_event_(struct event * ev,const struct timeval * tv)1016 bufferevent_add_event_(struct event *ev, const struct timeval *tv)
1017 {
1018 	if (!evutil_timerisset(tv))
1019 		return event_add(ev, NULL);
1020 	else
1021 		return event_add(ev, tv);
1022 }
1023 
1024 /* For use by user programs only; internally, we should be calling
1025    either bufferevent_incref_and_lock_(), or BEV_LOCK. */
1026 void
bufferevent_lock(struct bufferevent * bev)1027 bufferevent_lock(struct bufferevent *bev)
1028 {
1029 	bufferevent_incref_and_lock_(bev);
1030 }
1031 
1032 void
bufferevent_unlock(struct bufferevent * bev)1033 bufferevent_unlock(struct bufferevent *bev)
1034 {
1035 	bufferevent_decref_and_unlock_(bev);
1036 }
1037