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 #include <sys/cdefs.h>
40
41 #include <assert.h>
42 #ifndef WITHOUT_CAPSICUM
43 #include <capsicum_helpers.h>
44 #endif
45 #include <err.h>
46 #include <errno.h>
47 #include <stdbool.h>
48 #include <stdlib.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <sysexits.h>
52 #include <unistd.h>
53
54 #include <sys/types.h>
55 #ifndef WITHOUT_CAPSICUM
56 #include <sys/capsicum.h>
57 #endif
58 #ifdef __FreeBSD__
59 #include <sys/event.h>
60 #else
61 #include <port.h>
62 #include <sys/poll.h>
63 #include <sys/siginfo.h>
64 #include <sys/queue.h>
65 #include <sys/debug.h>
66 #include <sys/stat.h>
67 #endif
68 #include <sys/time.h>
69
70 #include <pthread.h>
71 #include <pthread_np.h>
72
73 #include "mevent.h"
74
75 #define MEVENT_MAX 64
76
77 #ifndef __FreeBSD__
78 #define EV_ENABLE 0x01
79 #define EV_ADD EV_ENABLE
80 #define EV_DISABLE 0x02
81 #define EV_DELETE 0x04
82
83 static int mevent_file_poll_interval_ms = 5000;
84 #endif
85
86 static pthread_t mevent_tid;
87 static pthread_once_t mevent_once = PTHREAD_ONCE_INIT;
88 #ifdef __FreeBSD__
89 static int mevent_timid = 43;
90 #endif
91 static int mevent_pipefd[2];
92 static int mfd;
93 static pthread_mutex_t mevent_lmutex = PTHREAD_MUTEX_INITIALIZER;
94
95 struct mevent {
96 void (*me_func)(int, enum ev_type, void *);
97 #define me_msecs me_fd
98 int me_fd;
99 #ifdef __FreeBSD__
100 int me_timid;
101 #else
102 timer_t me_timid;
103 #endif
104 enum ev_type me_type;
105 void *me_param;
106 int me_cq;
107 int me_state; /* Desired kevent flags. */
108 int me_closefd;
109 int me_fflags;
110 #ifndef __FreeBSD__
111 port_notify_t me_notify;
112 struct sigevent me_sigev;
113 boolean_t me_auto_requeue;
114 struct {
115 int mp_fd;
116 off_t mp_size;
117 void (*mp_func)(int, enum ev_type, void *);
118 void *mp_param;
119 } me_poll;
120 #endif
121 LIST_ENTRY(mevent) me_list;
122 };
123
LIST_HEAD(listhead,mevent)124 static LIST_HEAD(listhead, mevent) global_head, change_head;
125
126 static void
127 mevent_qlock(void)
128 {
129 pthread_mutex_lock(&mevent_lmutex);
130 }
131
132 static void
mevent_qunlock(void)133 mevent_qunlock(void)
134 {
135 pthread_mutex_unlock(&mevent_lmutex);
136 }
137
138 static void
mevent_pipe_read(int fd,enum ev_type type __unused,void * param __unused)139 mevent_pipe_read(int fd, enum ev_type type __unused, void *param __unused)
140 {
141 char buf[MEVENT_MAX];
142 int status;
143
144 /*
145 * Drain the pipe read side. The fd is non-blocking so this is
146 * safe to do.
147 */
148 do {
149 status = read(fd, buf, sizeof(buf));
150 } while (status == MEVENT_MAX);
151 }
152
153 static void
mevent_notify(void)154 mevent_notify(void)
155 {
156 char c = '\0';
157
158 /*
159 * If calling from outside the i/o thread, write a byte on the
160 * pipe to force the i/o thread to exit the blocking kevent call.
161 */
162 if (mevent_pipefd[1] != 0 && pthread_self() != mevent_tid) {
163 write(mevent_pipefd[1], &c, 1);
164 }
165 }
166
167 static void
mevent_init(void)168 mevent_init(void)
169 {
170 #ifndef WITHOUT_CAPSICUM
171 cap_rights_t rights;
172 #endif
173
174 #ifdef __FreeBSD__
175 mfd = kqueue();
176 #else
177 mfd = port_create();
178 #endif
179 assert(mfd > 0);
180
181 #ifndef WITHOUT_CAPSICUM
182 cap_rights_init(&rights, CAP_KQUEUE);
183 if (caph_rights_limit(mfd, &rights) == -1)
184 errx(EX_OSERR, "Unable to apply rights for sandbox");
185 #endif
186
187 LIST_INIT(&change_head);
188 LIST_INIT(&global_head);
189 }
190
191
192 #ifdef __FreeBSD__
193 static int
mevent_kq_filter(struct mevent * mevp)194 mevent_kq_filter(struct mevent *mevp)
195 {
196 int retval;
197
198 retval = 0;
199
200 if (mevp->me_type == EVF_READ)
201 retval = EVFILT_READ;
202
203 if (mevp->me_type == EVF_WRITE)
204 retval = EVFILT_WRITE;
205
206 if (mevp->me_type == EVF_TIMER)
207 retval = EVFILT_TIMER;
208
209 if (mevp->me_type == EVF_SIGNAL)
210 retval = EVFILT_SIGNAL;
211
212 if (mevp->me_type == EVF_VNODE)
213 retval = EVFILT_VNODE;
214
215 return (retval);
216 }
217
218 static int
mevent_kq_flags(struct mevent * mevp)219 mevent_kq_flags(struct mevent *mevp)
220 {
221 int retval;
222
223 retval = mevp->me_state;
224
225 if (mevp->me_type == EVF_VNODE)
226 retval |= EV_CLEAR;
227
228 return (retval);
229 }
230
231 static int
mevent_kq_fflags(struct mevent * mevp)232 mevent_kq_fflags(struct mevent *mevp)
233 {
234 int retval;
235
236 retval = 0;
237
238 switch (mevp->me_type) {
239 case EVF_VNODE:
240 if ((mevp->me_fflags & EVFF_ATTRIB) != 0)
241 retval |= NOTE_ATTRIB;
242 break;
243 case EVF_READ:
244 case EVF_WRITE:
245 case EVF_TIMER:
246 case EVF_SIGNAL:
247 break;
248 }
249
250 return (retval);
251 }
252
253 static void
mevent_populate(struct mevent * mevp,struct kevent * kev)254 mevent_populate(struct mevent *mevp, struct kevent *kev)
255 {
256 if (mevp->me_type == EVF_TIMER) {
257 kev->ident = mevp->me_timid;
258 kev->data = mevp->me_msecs;
259 } else {
260 kev->ident = mevp->me_fd;
261 kev->data = 0;
262 }
263 kev->filter = mevent_kq_filter(mevp);
264 kev->flags = mevent_kq_flags(mevp);
265 kev->fflags = mevent_kq_fflags(mevp);
266 kev->udata = mevp;
267 }
268
269 static int
mevent_build(struct kevent * kev)270 mevent_build(struct kevent *kev)
271 {
272 struct mevent *mevp, *tmpp;
273 int i;
274
275 i = 0;
276
277 mevent_qlock();
278
279 LIST_FOREACH_SAFE(mevp, &change_head, me_list, tmpp) {
280 if (mevp->me_closefd) {
281 /*
282 * A close of the file descriptor will remove the
283 * event
284 */
285 close(mevp->me_fd);
286 } else {
287 assert((mevp->me_state & EV_ADD) == 0);
288 mevent_populate(mevp, &kev[i]);
289 i++;
290 }
291
292 mevp->me_cq = 0;
293 LIST_REMOVE(mevp, me_list);
294
295 if (mevp->me_state & EV_DELETE) {
296 free(mevp);
297 } else {
298 LIST_INSERT_HEAD(&global_head, mevp, me_list);
299 }
300
301 assert(i < MEVENT_MAX);
302 }
303
304 mevent_qunlock();
305
306 return (i);
307 }
308
309 static void
mevent_handle(struct kevent * kev,int numev)310 mevent_handle(struct kevent *kev, int numev)
311 {
312 struct mevent *mevp;
313 int i;
314
315 for (i = 0; i < numev; i++) {
316 mevp = kev[i].udata;
317
318 /* XXX check for EV_ERROR ? */
319
320 (*mevp->me_func)(mevp->me_fd, mevp->me_type, mevp->me_param);
321 }
322 }
323
324 #else /* __FreeBSD__ */
325
326 static boolean_t
mevent_clarify_state(struct mevent * mevp)327 mevent_clarify_state(struct mevent *mevp)
328 {
329 const int state = mevp->me_state;
330
331 if ((state & EV_DELETE) != 0) {
332 /* All other intents are overriden by delete. */
333 mevp->me_state = EV_DELETE;
334 return (B_TRUE);
335 }
336
337 /*
338 * Without a distinction between EV_ADD and EV_ENABLE in our emulation,
339 * handling the add-disabled case means eliding the portfs operation
340 * when both flags are present.
341 *
342 * This is not a concern for subsequent enable/disable operations, as
343 * mevent_update() toggles the flags properly so they are not left in
344 * conflict.
345 */
346 if (state == (EV_ENABLE|EV_DISABLE)) {
347 mevp->me_state = EV_DISABLE;
348 return (B_FALSE);
349 }
350
351 return (B_TRUE);
352 }
353
354 static void
mevent_poll_file_attrib(int fd,enum ev_type type,void * param)355 mevent_poll_file_attrib(int fd, enum ev_type type, void *param)
356 {
357 struct mevent *mevp = param;
358 struct stat st;
359
360 if (fstat(mevp->me_poll.mp_fd, &st) != 0) {
361 (void) fprintf(stderr, "%s: fstat(%d) failed: %s\n",
362 __func__, fd, strerror(errno));
363 return;
364 }
365
366 /*
367 * The only current consumer of file attribute monitoring is
368 * blockif, which wants to know about size changes.
369 */
370 if (mevp->me_poll.mp_size != st.st_size) {
371 mevp->me_poll.mp_size = st.st_size;
372
373 (*mevp->me_poll.mp_func)(mevp->me_poll.mp_fd, EVF_VNODE,
374 mevp->me_poll.mp_param);
375 }
376 }
377
378 static void
mevent_update_one_readwrite(struct mevent * mevp)379 mevent_update_one_readwrite(struct mevent *mevp)
380 {
381 int portfd = mevp->me_notify.portnfy_port;
382
383 mevp->me_auto_requeue = B_FALSE;
384
385 switch (mevp->me_state) {
386 case EV_ENABLE:
387 {
388 const int events = (mevp->me_type == EVF_READ) ?
389 POLLIN : POLLOUT;
390
391 if (port_associate(portfd, PORT_SOURCE_FD, mevp->me_fd,
392 events, mevp) != 0) {
393 (void) fprintf(stderr,
394 "port_associate fd %d %p failed: %s\n",
395 mevp->me_fd, mevp, strerror(errno));
396 }
397 return;
398 }
399 case EV_DISABLE:
400 case EV_DELETE:
401 /*
402 * A disable that comes in while an event is being
403 * handled will result in an ENOENT.
404 */
405 if (port_dissociate(portfd, PORT_SOURCE_FD,
406 mevp->me_fd) != 0 && errno != ENOENT) {
407 (void) fprintf(stderr, "port_dissociate "
408 "portfd %d fd %d mevp %p failed: %s\n",
409 portfd, mevp->me_fd, mevp, strerror(errno));
410 }
411 return;
412 default:
413 (void) fprintf(stderr, "%s: unhandled state %d\n", __func__,
414 mevp->me_state);
415 abort();
416 }
417 }
418
419 static void
mevent_update_one_timer(struct mevent * mevp)420 mevent_update_one_timer(struct mevent *mevp)
421 {
422 mevp->me_auto_requeue = B_TRUE;
423
424 switch (mevp->me_state) {
425 case EV_ENABLE:
426 {
427 struct itimerspec it = { 0 };
428
429 mevp->me_sigev.sigev_notify = SIGEV_PORT;
430 mevp->me_sigev.sigev_value.sival_ptr = &mevp->me_notify;
431
432 if (timer_create(CLOCK_REALTIME, &mevp->me_sigev,
433 &mevp->me_timid) != 0) {
434 (void) fprintf(stderr, "timer_create failed: %s",
435 strerror(errno));
436 return;
437 }
438
439 /* The first timeout */
440 it.it_value.tv_sec = mevp->me_msecs / MILLISEC;
441 it.it_value.tv_nsec =
442 MSEC2NSEC(mevp->me_msecs % MILLISEC);
443 /* Repeat at the same interval */
444 it.it_interval = it.it_value;
445
446 if (timer_settime(mevp->me_timid, 0, &it, NULL) != 0) {
447 (void) fprintf(stderr, "timer_settime failed: %s",
448 strerror(errno));
449 }
450 return;
451 }
452 case EV_DISABLE:
453 case EV_DELETE:
454 if (timer_delete(mevp->me_timid) != 0) {
455 (void) fprintf(stderr, "timer_delete failed: %s",
456 strerror(errno));
457 }
458 mevp->me_timid = -1;
459 return;
460 default:
461 (void) fprintf(stderr, "%s: unhandled state %d\n", __func__,
462 mevp->me_state);
463 abort();
464 }
465 }
466
467 static void
mevent_update_one_vnode(struct mevent * mevp)468 mevent_update_one_vnode(struct mevent *mevp)
469 {
470 switch (mevp->me_state) {
471 case EV_ENABLE:
472 {
473 struct stat st;
474 int events = 0;
475
476 if ((mevp->me_fflags & EVFF_ATTRIB) != 0)
477 events |= FILE_ATTRIB;
478
479 assert(events != 0);
480
481 /*
482 * It is tempting to use the PORT_SOURCE_FILE type for this in
483 * conjunction with the FILE_ATTRIB event type. Unfortunately
484 * this event type triggers on any change to the file's
485 * ctime, and therefore for every write as well as attribute
486 * changes. It also does not work for ZVOLs.
487 *
488 * Convert this to a timer event and poll for the file
489 * attribute changes that we care about.
490 */
491
492 if (fstat(mevp->me_fd, &st) != 0) {
493 (void) fprintf(stderr, "fstat(%d) failed: %s\n",
494 mevp->me_fd, strerror(errno));
495 return;
496 }
497
498 mevp->me_poll.mp_fd = mevp->me_fd;
499 mevp->me_poll.mp_size = st.st_size;
500
501 mevp->me_poll.mp_func = mevp->me_func;
502 mevp->me_poll.mp_param = mevp->me_param;
503 mevp->me_func = mevent_poll_file_attrib;
504 mevp->me_param = mevp;
505
506 mevp->me_type = EVF_TIMER;
507 mevp->me_timid = -1;
508 mevp->me_msecs = mevent_file_poll_interval_ms;
509 mevent_update_one_timer(mevp);
510
511 return;
512 }
513 case EV_DISABLE:
514 case EV_DELETE:
515 /*
516 * These events do not really exist as they are converted to
517 * timers; fall through to abort.
518 */
519 default:
520 (void) fprintf(stderr, "%s: unhandled state %d\n", __func__,
521 mevp->me_state);
522 abort();
523 }
524 }
525
526 static void
mevent_update_one(struct mevent * mevp)527 mevent_update_one(struct mevent *mevp)
528 {
529 switch (mevp->me_type) {
530 case EVF_READ:
531 case EVF_WRITE:
532 mevent_update_one_readwrite(mevp);
533 break;
534 case EVF_TIMER:
535 mevent_update_one_timer(mevp);
536 break;
537 case EVF_VNODE:
538 mevent_update_one_vnode(mevp);
539 break;
540 case EVF_SIGNAL: /* EVF_SIGNAL not yet implemented. */
541 default:
542 (void) fprintf(stderr, "%s: unhandled event type %d\n",
543 __func__, mevp->me_type);
544 abort();
545 }
546 }
547
548 static void
mevent_populate(struct mevent * mevp)549 mevent_populate(struct mevent *mevp)
550 {
551 mevp->me_notify.portnfy_port = mfd;
552 mevp->me_notify.portnfy_user = mevp;
553 }
554
555 static void
mevent_update_pending()556 mevent_update_pending()
557 {
558 struct mevent *mevp, *tmpp;
559
560 mevent_qlock();
561
562 LIST_FOREACH_SAFE(mevp, &change_head, me_list, tmpp) {
563 mevent_populate(mevp);
564 if (mevp->me_closefd) {
565 /*
566 * A close of the file descriptor will remove the
567 * event
568 */
569 (void) close(mevp->me_fd);
570 mevp->me_fd = -1;
571 } else {
572 if (mevent_clarify_state(mevp)) {
573 mevent_update_one(mevp);
574 }
575 }
576
577 mevp->me_cq = 0;
578 LIST_REMOVE(mevp, me_list);
579
580 if (mevp->me_state & EV_DELETE) {
581 free(mevp);
582 } else {
583 LIST_INSERT_HEAD(&global_head, mevp, me_list);
584 }
585 }
586
587 mevent_qunlock();
588 }
589
590 static void
mevent_handle_pe(port_event_t * pe)591 mevent_handle_pe(port_event_t *pe)
592 {
593 struct mevent *mevp = pe->portev_user;
594
595 (*mevp->me_func)(mevp->me_fd, mevp->me_type, mevp->me_param);
596
597 mevent_qlock();
598 if (!mevp->me_cq && !mevp->me_auto_requeue) {
599 mevent_update_one(mevp);
600 }
601 mevent_qunlock();
602 }
603 #endif
604
605 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)606 mevent_add_state(int tfd, enum ev_type type,
607 void (*func)(int, enum ev_type, void *), void *param,
608 int state, int fflags)
609 {
610 #ifdef __FreeBSD__
611 struct kevent kev;
612 #endif
613 struct mevent *lp, *mevp;
614 #ifdef __FreeBSD__
615 int ret;
616 #endif
617
618 if (tfd < 0 || func == NULL) {
619 return (NULL);
620 }
621
622 mevp = NULL;
623
624 pthread_once(&mevent_once, mevent_init);
625
626 mevent_qlock();
627
628 /*
629 * Verify that the fd/type tuple is not present in any list
630 */
631 LIST_FOREACH(lp, &global_head, me_list) {
632 if (type != EVF_TIMER && lp->me_fd == tfd &&
633 lp->me_type == type) {
634 goto exit;
635 }
636 }
637
638 LIST_FOREACH(lp, &change_head, me_list) {
639 if (type != EVF_TIMER && lp->me_fd == tfd &&
640 lp->me_type == type) {
641 goto exit;
642 }
643 }
644
645 /*
646 * Allocate an entry and populate it.
647 */
648 mevp = calloc(1, sizeof(struct mevent));
649 if (mevp == NULL) {
650 goto exit;
651 }
652
653 if (type == EVF_TIMER) {
654 mevp->me_msecs = tfd;
655 #ifdef __FreeBSD__
656 mevp->me_timid = mevent_timid++;
657 #else
658 mevp->me_timid = -1;
659 #endif
660 } else
661 mevp->me_fd = tfd;
662 mevp->me_type = type;
663 mevp->me_func = func;
664 mevp->me_param = param;
665 mevp->me_state = state;
666 mevp->me_fflags = fflags;
667
668 /*
669 * Try to add the event. If this fails, report the failure to
670 * the caller.
671 */
672 #ifdef __FreeBSD__
673 mevent_populate(mevp, &kev);
674 ret = kevent(mfd, &kev, 1, NULL, 0, NULL);
675 if (ret == -1) {
676 free(mevp);
677 mevp = NULL;
678 goto exit;
679 }
680 mevp->me_state &= ~EV_ADD;
681 #else
682 mevent_populate(mevp);
683 if (mevent_clarify_state(mevp))
684 mevent_update_one(mevp);
685 #endif
686
687 LIST_INSERT_HEAD(&global_head, mevp, me_list);
688
689 exit:
690 mevent_qunlock();
691
692 return (mevp);
693 }
694
695 struct mevent *
mevent_add(int tfd,enum ev_type type,void (* func)(int,enum ev_type,void *),void * param)696 mevent_add(int tfd, enum ev_type type,
697 void (*func)(int, enum ev_type, void *), void *param)
698 {
699
700 return (mevent_add_state(tfd, type, func, param, EV_ADD, 0));
701 }
702
703 struct mevent *
mevent_add_flags(int tfd,enum ev_type type,int fflags,void (* func)(int,enum ev_type,void *),void * param)704 mevent_add_flags(int tfd, enum ev_type type, int fflags,
705 void (*func)(int, enum ev_type, void *), void *param)
706 {
707
708 return (mevent_add_state(tfd, type, func, param, EV_ADD, fflags));
709 }
710
711 struct mevent *
mevent_add_disabled(int tfd,enum ev_type type,void (* func)(int,enum ev_type,void *),void * param)712 mevent_add_disabled(int tfd, enum ev_type type,
713 void (*func)(int, enum ev_type, void *), void *param)
714 {
715
716 return (mevent_add_state(tfd, type, func, param, EV_ADD | EV_DISABLE, 0));
717 }
718
719 static int
mevent_update(struct mevent * evp,bool enable)720 mevent_update(struct mevent *evp, bool enable)
721 {
722 int newstate;
723
724 mevent_qlock();
725
726 /*
727 * It's not possible to enable/disable a deleted event
728 */
729 assert((evp->me_state & EV_DELETE) == 0);
730
731 newstate = evp->me_state;
732 if (enable) {
733 newstate |= EV_ENABLE;
734 newstate &= ~EV_DISABLE;
735 } else {
736 newstate |= EV_DISABLE;
737 newstate &= ~EV_ENABLE;
738 }
739
740 /*
741 * No update needed if state isn't changing
742 */
743 if (evp->me_state != newstate) {
744 evp->me_state = newstate;
745
746 /*
747 * Place the entry onto the changed list if not
748 * already there.
749 */
750 if (evp->me_cq == 0) {
751 evp->me_cq = 1;
752 LIST_REMOVE(evp, me_list);
753 LIST_INSERT_HEAD(&change_head, evp, me_list);
754 mevent_notify();
755 }
756 }
757
758 mevent_qunlock();
759
760 return (0);
761 }
762
763 int
mevent_enable(struct mevent * evp)764 mevent_enable(struct mevent *evp)
765 {
766
767 return (mevent_update(evp, true));
768 }
769
770 int
mevent_disable(struct mevent * evp)771 mevent_disable(struct mevent *evp)
772 {
773
774 return (mevent_update(evp, false));
775 }
776
777 static int
mevent_delete_event(struct mevent * evp,int closefd)778 mevent_delete_event(struct mevent *evp, int closefd)
779 {
780 mevent_qlock();
781
782 /*
783 * Place the entry onto the changed list if not already there, and
784 * mark as to be deleted.
785 */
786 if (evp->me_cq == 0) {
787 evp->me_cq = 1;
788 LIST_REMOVE(evp, me_list);
789 LIST_INSERT_HEAD(&change_head, evp, me_list);
790 mevent_notify();
791 }
792 evp->me_state = EV_DELETE;
793
794 if (closefd)
795 evp->me_closefd = 1;
796
797 mevent_qunlock();
798
799 return (0);
800 }
801
802 int
mevent_delete(struct mevent * evp)803 mevent_delete(struct mevent *evp)
804 {
805
806 return (mevent_delete_event(evp, 0));
807 }
808
809 int
mevent_delete_close(struct mevent * evp)810 mevent_delete_close(struct mevent *evp)
811 {
812
813 return (mevent_delete_event(evp, 1));
814 }
815
816 static void
mevent_set_name(void)817 mevent_set_name(void)
818 {
819
820 pthread_set_name_np(mevent_tid, "mevent");
821 }
822
823 void
mevent_dispatch(void)824 mevent_dispatch(void)
825 {
826 #ifdef __FreeBSD__
827 struct kevent changelist[MEVENT_MAX];
828 struct kevent eventlist[MEVENT_MAX];
829 struct mevent *pipev;
830 int numev;
831 #else
832 struct mevent *pipev;
833 #endif
834 int ret;
835 #ifndef WITHOUT_CAPSICUM
836 cap_rights_t rights;
837 #endif
838
839 mevent_tid = pthread_self();
840 mevent_set_name();
841
842 pthread_once(&mevent_once, mevent_init);
843
844 /*
845 * Open the pipe that will be used for other threads to force
846 * the blocking kqueue call to exit by writing to it. Set the
847 * descriptor to non-blocking.
848 */
849 ret = pipe(mevent_pipefd);
850 if (ret < 0) {
851 perror("pipe");
852 exit(0);
853 }
854
855 #ifndef WITHOUT_CAPSICUM
856 cap_rights_init(&rights, CAP_EVENT, CAP_READ, CAP_WRITE);
857 if (caph_rights_limit(mevent_pipefd[0], &rights) == -1)
858 errx(EX_OSERR, "Unable to apply rights for sandbox");
859 if (caph_rights_limit(mevent_pipefd[1], &rights) == -1)
860 errx(EX_OSERR, "Unable to apply rights for sandbox");
861 #endif
862
863 /*
864 * Add internal event handler for the pipe write fd
865 */
866 pipev = mevent_add(mevent_pipefd[0], EVF_READ, mevent_pipe_read, NULL);
867 assert(pipev != NULL);
868
869 for (;;) {
870 #ifdef __FreeBSD__
871 /*
872 * Build changelist if required.
873 * XXX the changelist can be put into the blocking call
874 * to eliminate the extra syscall. Currently better for
875 * debug.
876 */
877 numev = mevent_build(changelist);
878 if (numev) {
879 ret = kevent(mfd, changelist, numev, NULL, 0, NULL);
880 if (ret == -1) {
881 perror("Error return from kevent change");
882 }
883 }
884
885 /*
886 * Block awaiting events
887 */
888 ret = kevent(mfd, NULL, 0, eventlist, MEVENT_MAX, NULL);
889 if (ret == -1 && errno != EINTR) {
890 perror("Error return from kevent monitor");
891 }
892
893 /*
894 * Handle reported events
895 */
896 mevent_handle(eventlist, ret);
897
898 #else /* __FreeBSD__ */
899 port_event_t pev;
900
901 /* Handle any pending updates */
902 mevent_update_pending();
903
904 /* Block awaiting events */
905 ret = port_get(mfd, &pev, NULL);
906 if (ret != 0) {
907 if (errno != EINTR)
908 perror("Error return from port_get");
909 continue;
910 }
911
912 /* Handle reported event */
913 mevent_handle_pe(&pev);
914 #endif /* __FreeBSD__ */
915 }
916 }
917