1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2011 NetApp, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /*
30 * Copyright 2018 Joyent, Inc.
31 * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
32 */
33
34 /*
35 * Micro event library for FreeBSD, designed for a single i/o thread
36 * using kqueue, and having events be persistent by default.
37 */
38
39
40 #include <assert.h>
41 #ifndef WITHOUT_CAPSICUM
42 #include <capsicum_helpers.h>
43 #endif
44 #include <err.h>
45 #include <errno.h>
46 #include <stdbool.h>
47 #include <stdlib.h>
48 #include <stdio.h>
49 #include <string.h>
50 #include <sysexits.h>
51 #include <unistd.h>
52
53 #include <sys/types.h>
54 #ifndef WITHOUT_CAPSICUM
55 #include <sys/capsicum.h>
56 #endif
57 #ifdef __FreeBSD__
58 #include <sys/event.h>
59 #else
60 #include <port.h>
61 #include <sys/poll.h>
62 #include <sys/siginfo.h>
63 #include <sys/queue.h>
64 #include <sys/debug.h>
65 #include <sys/stat.h>
66 #endif
67 #include <sys/time.h>
68
69 #include <pthread.h>
70 #include <pthread_np.h>
71
72 #include "mevent.h"
73
74 #define MEVENT_MAX 64
75
76 #ifndef __FreeBSD__
77 #define EV_ENABLE 0x01
78 #define EV_ADD EV_ENABLE
79 #define EV_DISABLE 0x02
80 #define EV_DELETE 0x04
81
82 static int mevent_file_poll_interval_ms = 5000;
83 #endif
84
85 static pthread_t mevent_tid;
86 static pthread_once_t mevent_once = PTHREAD_ONCE_INIT;
87 #ifdef __FreeBSD__
88 static int mevent_timid = 43;
89 #endif
90 static int mevent_pipefd[2];
91 static int mfd;
92 static pthread_mutex_t mevent_lmutex = PTHREAD_MUTEX_INITIALIZER;
93
94 struct mevent {
95 void (*me_func)(int, enum ev_type, void *);
96 #define me_msecs me_fd
97 int me_fd;
98 #ifdef __FreeBSD__
99 int me_timid;
100 #else
101 timer_t me_timid;
102 #endif
103 enum ev_type me_type;
104 void *me_param;
105 int me_cq;
106 int me_state; /* Desired kevent flags. */
107 int me_closefd;
108 int me_fflags;
109 #ifndef __FreeBSD__
110 port_notify_t me_notify;
111 struct sigevent me_sigev;
112 boolean_t me_auto_requeue;
113 struct {
114 int mp_fd;
115 off_t mp_size;
116 void (*mp_func)(int, enum ev_type, void *);
117 void *mp_param;
118 } me_poll;
119 #endif
120 LIST_ENTRY(mevent) me_list;
121 };
122
LIST_HEAD(listhead,mevent)123 static LIST_HEAD(listhead, mevent) global_head, change_head;
124
125 static void
126 mevent_qlock(void)
127 {
128 pthread_mutex_lock(&mevent_lmutex);
129 }
130
131 static void
mevent_qunlock(void)132 mevent_qunlock(void)
133 {
134 pthread_mutex_unlock(&mevent_lmutex);
135 }
136
137 static void
mevent_pipe_read(int fd,enum ev_type type __unused,void * param __unused)138 mevent_pipe_read(int fd, enum ev_type type __unused, void *param __unused)
139 {
140 char buf[MEVENT_MAX];
141 int status;
142
143 /*
144 * Drain the pipe read side. The fd is non-blocking so this is
145 * safe to do.
146 */
147 do {
148 status = read(fd, buf, sizeof(buf));
149 } while (status == MEVENT_MAX);
150 }
151
152 static void
mevent_notify(void)153 mevent_notify(void)
154 {
155 char c = '\0';
156
157 /*
158 * If calling from outside the i/o thread, write a byte on the
159 * pipe to force the i/o thread to exit the blocking kevent call.
160 */
161 if (mevent_pipefd[1] != 0 && pthread_self() != mevent_tid) {
162 write(mevent_pipefd[1], &c, 1);
163 }
164 }
165
166 static void
mevent_init(void)167 mevent_init(void)
168 {
169 #ifndef WITHOUT_CAPSICUM
170 cap_rights_t rights;
171 #endif
172
173 #ifdef __FreeBSD__
174 mfd = kqueue();
175 #else
176 mfd = port_create();
177 #endif
178 assert(mfd > 0);
179
180 #ifndef WITHOUT_CAPSICUM
181 cap_rights_init(&rights, CAP_KQUEUE);
182 if (caph_rights_limit(mfd, &rights) == -1)
183 errx(EX_OSERR, "Unable to apply rights for sandbox");
184 #endif
185
186 LIST_INIT(&change_head);
187 LIST_INIT(&global_head);
188 }
189
190
191 #ifdef __FreeBSD__
192 static int
mevent_kq_filter(struct mevent * mevp)193 mevent_kq_filter(struct mevent *mevp)
194 {
195 int retval;
196
197 retval = 0;
198
199 if (mevp->me_type == EVF_READ)
200 retval = EVFILT_READ;
201
202 if (mevp->me_type == EVF_WRITE)
203 retval = EVFILT_WRITE;
204
205 if (mevp->me_type == EVF_TIMER)
206 retval = EVFILT_TIMER;
207
208 if (mevp->me_type == EVF_SIGNAL)
209 retval = EVFILT_SIGNAL;
210
211 if (mevp->me_type == EVF_VNODE)
212 retval = EVFILT_VNODE;
213
214 return (retval);
215 }
216
217 static int
mevent_kq_flags(struct mevent * mevp)218 mevent_kq_flags(struct mevent *mevp)
219 {
220 int retval;
221
222 retval = mevp->me_state;
223
224 if (mevp->me_type == EVF_VNODE)
225 retval |= EV_CLEAR;
226
227 return (retval);
228 }
229
230 static int
mevent_kq_fflags(struct mevent * mevp)231 mevent_kq_fflags(struct mevent *mevp)
232 {
233 int retval;
234
235 retval = 0;
236
237 switch (mevp->me_type) {
238 case EVF_VNODE:
239 if ((mevp->me_fflags & EVFF_ATTRIB) != 0)
240 retval |= NOTE_ATTRIB;
241 break;
242 case EVF_READ:
243 case EVF_WRITE:
244 case EVF_TIMER:
245 case EVF_SIGNAL:
246 break;
247 }
248
249 return (retval);
250 }
251
252 static void
mevent_populate(struct mevent * mevp,struct kevent * kev)253 mevent_populate(struct mevent *mevp, struct kevent *kev)
254 {
255 if (mevp->me_type == EVF_TIMER) {
256 kev->ident = mevp->me_timid;
257 kev->data = mevp->me_msecs;
258 } else {
259 kev->ident = mevp->me_fd;
260 kev->data = 0;
261 }
262 kev->filter = mevent_kq_filter(mevp);
263 kev->flags = mevent_kq_flags(mevp);
264 kev->fflags = mevent_kq_fflags(mevp);
265 kev->udata = mevp;
266 }
267
268 static int
mevent_build(struct kevent * kev)269 mevent_build(struct kevent *kev)
270 {
271 struct mevent *mevp, *tmpp;
272 int i;
273
274 i = 0;
275
276 mevent_qlock();
277
278 LIST_FOREACH_SAFE(mevp, &change_head, me_list, tmpp) {
279 if (mevp->me_closefd) {
280 /*
281 * A close of the file descriptor will remove the
282 * event
283 */
284 close(mevp->me_fd);
285 } else {
286 assert((mevp->me_state & EV_ADD) == 0);
287 mevent_populate(mevp, &kev[i]);
288 i++;
289 }
290
291 mevp->me_cq = 0;
292 LIST_REMOVE(mevp, me_list);
293
294 if (mevp->me_state & EV_DELETE) {
295 free(mevp);
296 } else {
297 LIST_INSERT_HEAD(&global_head, mevp, me_list);
298 }
299
300 assert(i < MEVENT_MAX);
301 }
302
303 mevent_qunlock();
304
305 return (i);
306 }
307
308 static void
mevent_handle(struct kevent * kev,int numev)309 mevent_handle(struct kevent *kev, int numev)
310 {
311 struct mevent *mevp;
312 int i;
313
314 for (i = 0; i < numev; i++) {
315 mevp = kev[i].udata;
316
317 /* XXX check for EV_ERROR ? */
318
319 (*mevp->me_func)(mevp->me_fd, mevp->me_type, mevp->me_param);
320 }
321 }
322
323 #else /* __FreeBSD__ */
324
325 static boolean_t
mevent_clarify_state(struct mevent * mevp)326 mevent_clarify_state(struct mevent *mevp)
327 {
328 const int state = mevp->me_state;
329
330 if ((state & EV_DELETE) != 0) {
331 /* All other intents are overriden by delete. */
332 mevp->me_state = EV_DELETE;
333 return (B_TRUE);
334 }
335
336 /*
337 * Without a distinction between EV_ADD and EV_ENABLE in our emulation,
338 * handling the add-disabled case means eliding the portfs operation
339 * when both flags are present.
340 *
341 * This is not a concern for subsequent enable/disable operations, as
342 * mevent_update() toggles the flags properly so they are not left in
343 * conflict.
344 */
345 if (state == (EV_ENABLE|EV_DISABLE)) {
346 mevp->me_state = EV_DISABLE;
347 return (B_FALSE);
348 }
349
350 return (B_TRUE);
351 }
352
353 static void
mevent_poll_file_attrib(int fd,enum ev_type type,void * param)354 mevent_poll_file_attrib(int fd, enum ev_type type, void *param)
355 {
356 struct mevent *mevp = param;
357 struct stat st;
358
359 if (fstat(mevp->me_poll.mp_fd, &st) != 0) {
360 (void) fprintf(stderr, "%s: fstat(%d) failed: %s\n",
361 __func__, fd, strerror(errno));
362 return;
363 }
364
365 /*
366 * The only current consumer of file attribute monitoring is
367 * blockif, which wants to know about size changes.
368 */
369 if (mevp->me_poll.mp_size != st.st_size) {
370 mevp->me_poll.mp_size = st.st_size;
371
372 (*mevp->me_poll.mp_func)(mevp->me_poll.mp_fd, EVF_VNODE,
373 mevp->me_poll.mp_param);
374 }
375 }
376
377 static void
mevent_update_one_readwrite(struct mevent * mevp)378 mevent_update_one_readwrite(struct mevent *mevp)
379 {
380 int portfd = mevp->me_notify.portnfy_port;
381
382 mevp->me_auto_requeue = B_FALSE;
383
384 switch (mevp->me_state) {
385 case EV_ENABLE:
386 {
387 const int events = (mevp->me_type == EVF_READ) ?
388 POLLIN : POLLOUT;
389
390 if (port_associate(portfd, PORT_SOURCE_FD, mevp->me_fd,
391 events, mevp) != 0) {
392 (void) fprintf(stderr,
393 "port_associate fd %d %p failed: %s\n",
394 mevp->me_fd, mevp, strerror(errno));
395 }
396 return;
397 }
398 case EV_DISABLE:
399 case EV_DELETE:
400 /*
401 * A disable that comes in while an event is being
402 * handled will result in an ENOENT.
403 */
404 if (port_dissociate(portfd, PORT_SOURCE_FD,
405 mevp->me_fd) != 0 && errno != ENOENT) {
406 (void) fprintf(stderr, "port_dissociate "
407 "portfd %d fd %d mevp %p failed: %s\n",
408 portfd, mevp->me_fd, mevp, strerror(errno));
409 }
410 return;
411 default:
412 (void) fprintf(stderr, "%s: unhandled state %d\n", __func__,
413 mevp->me_state);
414 abort();
415 }
416 }
417
418 static void
mevent_update_one_timer(struct mevent * mevp)419 mevent_update_one_timer(struct mevent *mevp)
420 {
421 mevp->me_auto_requeue = B_TRUE;
422
423 switch (mevp->me_state) {
424 case EV_ENABLE:
425 {
426 struct itimerspec it = { 0 };
427
428 mevp->me_sigev.sigev_notify = SIGEV_PORT;
429 mevp->me_sigev.sigev_value.sival_ptr = &mevp->me_notify;
430
431 if (timer_create(CLOCK_REALTIME, &mevp->me_sigev,
432 &mevp->me_timid) != 0) {
433 (void) fprintf(stderr, "timer_create failed: %s",
434 strerror(errno));
435 return;
436 }
437
438 /* The first timeout */
439 it.it_value.tv_sec = mevp->me_msecs / MILLISEC;
440 it.it_value.tv_nsec =
441 MSEC2NSEC(mevp->me_msecs % MILLISEC);
442 /* Repeat at the same interval */
443 it.it_interval = it.it_value;
444
445 if (timer_settime(mevp->me_timid, 0, &it, NULL) != 0) {
446 (void) fprintf(stderr, "timer_settime failed: %s",
447 strerror(errno));
448 }
449 return;
450 }
451 case EV_DISABLE:
452 case EV_DELETE:
453 if (timer_delete(mevp->me_timid) != 0) {
454 (void) fprintf(stderr, "timer_delete failed: %s",
455 strerror(errno));
456 }
457 mevp->me_timid = -1;
458 return;
459 default:
460 (void) fprintf(stderr, "%s: unhandled state %d\n", __func__,
461 mevp->me_state);
462 abort();
463 }
464 }
465
466 static void
mevent_update_one_vnode(struct mevent * mevp)467 mevent_update_one_vnode(struct mevent *mevp)
468 {
469 switch (mevp->me_state) {
470 case EV_ENABLE:
471 {
472 struct stat st;
473 int events = 0;
474
475 if ((mevp->me_fflags & EVFF_ATTRIB) != 0)
476 events |= FILE_ATTRIB;
477
478 assert(events != 0);
479
480 /*
481 * It is tempting to use the PORT_SOURCE_FILE type for this in
482 * conjunction with the FILE_ATTRIB event type. Unfortunately
483 * this event type triggers on any change to the file's
484 * ctime, and therefore for every write as well as attribute
485 * changes. It also does not work for ZVOLs.
486 *
487 * Convert this to a timer event and poll for the file
488 * attribute changes that we care about.
489 */
490
491 if (fstat(mevp->me_fd, &st) != 0) {
492 (void) fprintf(stderr, "fstat(%d) failed: %s\n",
493 mevp->me_fd, strerror(errno));
494 return;
495 }
496
497 mevp->me_poll.mp_fd = mevp->me_fd;
498 mevp->me_poll.mp_size = st.st_size;
499
500 mevp->me_poll.mp_func = mevp->me_func;
501 mevp->me_poll.mp_param = mevp->me_param;
502 mevp->me_func = mevent_poll_file_attrib;
503 mevp->me_param = mevp;
504
505 mevp->me_type = EVF_TIMER;
506 mevp->me_timid = -1;
507 mevp->me_msecs = mevent_file_poll_interval_ms;
508 mevent_update_one_timer(mevp);
509
510 return;
511 }
512 case EV_DISABLE:
513 case EV_DELETE:
514 /*
515 * These events do not really exist as they are converted to
516 * timers; fall through to abort.
517 */
518 default:
519 (void) fprintf(stderr, "%s: unhandled state %d\n", __func__,
520 mevp->me_state);
521 abort();
522 }
523 }
524
525 static void
mevent_update_one(struct mevent * mevp)526 mevent_update_one(struct mevent *mevp)
527 {
528 switch (mevp->me_type) {
529 case EVF_READ:
530 case EVF_WRITE:
531 mevent_update_one_readwrite(mevp);
532 break;
533 case EVF_TIMER:
534 mevent_update_one_timer(mevp);
535 break;
536 case EVF_VNODE:
537 mevent_update_one_vnode(mevp);
538 break;
539 case EVF_SIGNAL: /* EVF_SIGNAL not yet implemented. */
540 default:
541 (void) fprintf(stderr, "%s: unhandled event type %d\n",
542 __func__, mevp->me_type);
543 abort();
544 }
545 }
546
547 static void
mevent_populate(struct mevent * mevp)548 mevent_populate(struct mevent *mevp)
549 {
550 mevp->me_notify.portnfy_port = mfd;
551 mevp->me_notify.portnfy_user = mevp;
552 }
553
554 static void
mevent_update_pending()555 mevent_update_pending()
556 {
557 struct mevent *mevp, *tmpp;
558
559 mevent_qlock();
560
561 LIST_FOREACH_SAFE(mevp, &change_head, me_list, tmpp) {
562 mevent_populate(mevp);
563 if (mevp->me_closefd) {
564 /*
565 * A close of the file descriptor will remove the
566 * event
567 */
568 (void) close(mevp->me_fd);
569 mevp->me_fd = -1;
570 } else {
571 if (mevent_clarify_state(mevp)) {
572 mevent_update_one(mevp);
573 }
574 }
575
576 mevp->me_cq = 0;
577 LIST_REMOVE(mevp, me_list);
578
579 if (mevp->me_state & EV_DELETE) {
580 free(mevp);
581 } else {
582 LIST_INSERT_HEAD(&global_head, mevp, me_list);
583 }
584 }
585
586 mevent_qunlock();
587 }
588
589 static void
mevent_handle_pe(port_event_t * pe)590 mevent_handle_pe(port_event_t *pe)
591 {
592 struct mevent *mevp = pe->portev_user;
593
594 (*mevp->me_func)(mevp->me_fd, mevp->me_type, mevp->me_param);
595
596 mevent_qlock();
597 if (!mevp->me_cq && !mevp->me_auto_requeue) {
598 mevent_update_one(mevp);
599 }
600 mevent_qunlock();
601 }
602 #endif
603
604 static struct mevent *
mevent_add_state(int tfd,enum ev_type type,void (* func)(int,enum ev_type,void *),void * param,int state,int fflags)605 mevent_add_state(int tfd, enum ev_type type,
606 void (*func)(int, enum ev_type, void *), void *param,
607 int state, int fflags)
608 {
609 #ifdef __FreeBSD__
610 struct kevent kev;
611 #endif
612 struct mevent *lp, *mevp;
613 #ifdef __FreeBSD__
614 int ret;
615 #endif
616
617 if (tfd < 0 || func == NULL) {
618 return (NULL);
619 }
620
621 mevp = NULL;
622
623 pthread_once(&mevent_once, mevent_init);
624
625 mevent_qlock();
626
627 /*
628 * Verify that the fd/type tuple is not present in any list
629 */
630 LIST_FOREACH(lp, &global_head, me_list) {
631 if (type != EVF_TIMER && lp->me_fd == tfd &&
632 lp->me_type == type) {
633 goto exit;
634 }
635 }
636
637 LIST_FOREACH(lp, &change_head, me_list) {
638 if (type != EVF_TIMER && lp->me_fd == tfd &&
639 lp->me_type == type) {
640 goto exit;
641 }
642 }
643
644 /*
645 * Allocate an entry and populate it.
646 */
647 mevp = calloc(1, sizeof(struct mevent));
648 if (mevp == NULL) {
649 goto exit;
650 }
651
652 if (type == EVF_TIMER) {
653 mevp->me_msecs = tfd;
654 #ifdef __FreeBSD__
655 mevp->me_timid = mevent_timid++;
656 #else
657 mevp->me_timid = -1;
658 #endif
659 } else
660 mevp->me_fd = tfd;
661 mevp->me_type = type;
662 mevp->me_func = func;
663 mevp->me_param = param;
664 mevp->me_state = state;
665 mevp->me_fflags = fflags;
666
667 /*
668 * Try to add the event. If this fails, report the failure to
669 * the caller.
670 */
671 #ifdef __FreeBSD__
672 mevent_populate(mevp, &kev);
673 ret = kevent(mfd, &kev, 1, NULL, 0, NULL);
674 if (ret == -1) {
675 free(mevp);
676 mevp = NULL;
677 goto exit;
678 }
679 mevp->me_state &= ~EV_ADD;
680 #else
681 mevent_populate(mevp);
682 if (mevent_clarify_state(mevp))
683 mevent_update_one(mevp);
684 #endif
685
686 LIST_INSERT_HEAD(&global_head, mevp, me_list);
687
688 exit:
689 mevent_qunlock();
690
691 return (mevp);
692 }
693
694 struct mevent *
mevent_add(int tfd,enum ev_type type,void (* func)(int,enum ev_type,void *),void * param)695 mevent_add(int tfd, enum ev_type type,
696 void (*func)(int, enum ev_type, void *), void *param)
697 {
698
699 return (mevent_add_state(tfd, type, func, param, EV_ADD, 0));
700 }
701
702 struct mevent *
mevent_add_flags(int tfd,enum ev_type type,int fflags,void (* func)(int,enum ev_type,void *),void * param)703 mevent_add_flags(int tfd, enum ev_type type, int fflags,
704 void (*func)(int, enum ev_type, void *), void *param)
705 {
706
707 return (mevent_add_state(tfd, type, func, param, EV_ADD, fflags));
708 }
709
710 struct mevent *
mevent_add_disabled(int tfd,enum ev_type type,void (* func)(int,enum ev_type,void *),void * param)711 mevent_add_disabled(int tfd, enum ev_type type,
712 void (*func)(int, enum ev_type, void *), void *param)
713 {
714
715 return (mevent_add_state(tfd, type, func, param, EV_ADD | EV_DISABLE, 0));
716 }
717
718 static int
mevent_update(struct mevent * evp,bool enable)719 mevent_update(struct mevent *evp, bool enable)
720 {
721 int newstate;
722
723 mevent_qlock();
724
725 /*
726 * It's not possible to enable/disable a deleted event
727 */
728 assert((evp->me_state & EV_DELETE) == 0);
729
730 newstate = evp->me_state;
731 if (enable) {
732 newstate |= EV_ENABLE;
733 newstate &= ~EV_DISABLE;
734 } else {
735 newstate |= EV_DISABLE;
736 newstate &= ~EV_ENABLE;
737 }
738
739 /*
740 * No update needed if state isn't changing
741 */
742 if (evp->me_state != newstate) {
743 evp->me_state = newstate;
744
745 /*
746 * Place the entry onto the changed list if not
747 * already there.
748 */
749 if (evp->me_cq == 0) {
750 evp->me_cq = 1;
751 LIST_REMOVE(evp, me_list);
752 LIST_INSERT_HEAD(&change_head, evp, me_list);
753 mevent_notify();
754 }
755 }
756
757 mevent_qunlock();
758
759 return (0);
760 }
761
762 int
mevent_enable(struct mevent * evp)763 mevent_enable(struct mevent *evp)
764 {
765
766 return (mevent_update(evp, true));
767 }
768
769 int
mevent_disable(struct mevent * evp)770 mevent_disable(struct mevent *evp)
771 {
772
773 return (mevent_update(evp, false));
774 }
775
776 static int
mevent_delete_event(struct mevent * evp,int closefd)777 mevent_delete_event(struct mevent *evp, int closefd)
778 {
779 mevent_qlock();
780
781 /*
782 * Place the entry onto the changed list if not already there, and
783 * mark as to be deleted.
784 */
785 if (evp->me_cq == 0) {
786 evp->me_cq = 1;
787 LIST_REMOVE(evp, me_list);
788 LIST_INSERT_HEAD(&change_head, evp, me_list);
789 mevent_notify();
790 }
791 evp->me_state = EV_DELETE;
792
793 if (closefd)
794 evp->me_closefd = 1;
795
796 mevent_qunlock();
797
798 return (0);
799 }
800
801 int
mevent_delete(struct mevent * evp)802 mevent_delete(struct mevent *evp)
803 {
804
805 return (mevent_delete_event(evp, 0));
806 }
807
808 int
mevent_delete_close(struct mevent * evp)809 mevent_delete_close(struct mevent *evp)
810 {
811
812 return (mevent_delete_event(evp, 1));
813 }
814
815 static void
mevent_set_name(void)816 mevent_set_name(void)
817 {
818
819 pthread_set_name_np(mevent_tid, "mevent");
820 }
821
822 void
mevent_dispatch(void)823 mevent_dispatch(void)
824 {
825 #ifdef __FreeBSD__
826 struct kevent changelist[MEVENT_MAX];
827 struct kevent eventlist[MEVENT_MAX];
828 struct mevent *pipev;
829 int numev;
830 #else
831 struct mevent *pipev;
832 #endif
833 int ret;
834 #ifndef WITHOUT_CAPSICUM
835 cap_rights_t rights;
836 #endif
837
838 mevent_tid = pthread_self();
839 mevent_set_name();
840
841 pthread_once(&mevent_once, mevent_init);
842
843 /*
844 * Open the pipe that will be used for other threads to force
845 * the blocking kqueue call to exit by writing to it. Set the
846 * descriptor to non-blocking.
847 */
848 ret = pipe(mevent_pipefd);
849 if (ret < 0) {
850 perror("pipe");
851 exit(0);
852 }
853
854 #ifndef WITHOUT_CAPSICUM
855 cap_rights_init(&rights, CAP_EVENT, CAP_READ, CAP_WRITE);
856 if (caph_rights_limit(mevent_pipefd[0], &rights) == -1)
857 errx(EX_OSERR, "Unable to apply rights for sandbox");
858 if (caph_rights_limit(mevent_pipefd[1], &rights) == -1)
859 errx(EX_OSERR, "Unable to apply rights for sandbox");
860 #endif
861
862 /*
863 * Add internal event handler for the pipe write fd
864 */
865 pipev = mevent_add(mevent_pipefd[0], EVF_READ, mevent_pipe_read, NULL);
866 assert(pipev != NULL);
867
868 for (;;) {
869 #ifdef __FreeBSD__
870 /*
871 * Build changelist if required.
872 * XXX the changelist can be put into the blocking call
873 * to eliminate the extra syscall. Currently better for
874 * debug.
875 */
876 numev = mevent_build(changelist);
877 if (numev) {
878 ret = kevent(mfd, changelist, numev, NULL, 0, NULL);
879 if (ret == -1) {
880 perror("Error return from kevent change");
881 }
882 }
883
884 /*
885 * Block awaiting events
886 */
887 ret = kevent(mfd, NULL, 0, eventlist, MEVENT_MAX, NULL);
888 if (ret == -1 && errno != EINTR) {
889 perror("Error return from kevent monitor");
890 }
891
892 /*
893 * Handle reported events
894 */
895 mevent_handle(eventlist, ret);
896
897 #else /* __FreeBSD__ */
898 port_event_t pev;
899
900 /* Handle any pending updates */
901 mevent_update_pending();
902
903 /* Block awaiting events */
904 ret = port_get(mfd, &pev, NULL);
905 if (ret != 0) {
906 if (errno != EINTR)
907 perror("Error return from port_get");
908 continue;
909 }
910
911 /* Handle reported event */
912 mevent_handle_pe(&pev);
913 #endif /* __FreeBSD__ */
914 }
915 }
916