1/*-
2 * Copyright (c) 1999,2000 Jonathan Lemon <jlemon@FreeBSD.org>
3 * All rights reserved.
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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/kern/kern_event.c 70834 2001-01-09 04:33:49Z wollman $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/kernel.h>
32#include <sys/proc.h>
33#include <sys/malloc.h>
34#include <sys/unistd.h>
35#include <sys/file.h>
36#include <sys/fcntl.h>
37#include <sys/selinfo.h>
38#include <sys/queue.h>
39#include <sys/event.h>
40#include <sys/eventvar.h>
41#include <sys/poll.h>
42#include <sys/protosw.h>
43#include <sys/socket.h>
44#include <sys/socketvar.h>
45#include <sys/stat.h>
46#include <sys/sysproto.h>
47#include <sys/uio.h>
48
49#include <vm/vm_zone.h>
50
51static int filt_nullattach(struct knote *kn);
52static int filt_rwtypattach(struct knote *kn);
53static int filt_kqattach(struct knote *kn);
54static void filt_kqdetach(struct knote *kn);
55static int filt_kqueue(struct knote *kn, long hint);
56static int filt_procattach(struct knote *kn);
57static void filt_procdetach(struct knote *kn);
58static int filt_proc(struct knote *kn, long hint);
59
60static int kqueue_scan(struct file *fp, int maxevents,
61 struct kevent *ulistp, const struct timespec *timeout,
62 struct proc *p);
63static int kqueue_read(struct file *fp, struct uio *uio,
64 struct ucred *cred, int flags, struct proc *p);
65static int kqueue_write(struct file *fp, struct uio *uio,
66 struct ucred *cred, int flags, struct proc *p);
67static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
68 struct proc *p);
69static int kqueue_poll(struct file *fp, int events, struct ucred *cred,
70 struct proc *p);
71static int kqueue_stat(struct file *fp, struct stat *st, struct proc *p);
72static int kqueue_close(struct file *fp, struct proc *p);
73static void kqueue_wakeup(struct kqueue *kq);
74
75static void knote_attach(struct knote *kn, struct filedesc *fdp);
76static void knote_drop(struct knote *kn, struct proc *p);
77static void knote_enqueue(struct knote *kn);
78static void knote_dequeue(struct knote *kn);
79static void knote_init(void);
80static struct knote *knote_alloc(void);
81static void knote_free(struct knote *kn);
82
83static vm_zone_t knote_zone;
84
85#define KNOTE_ACTIVATE(kn) do { \
86 kn->kn_status |= KN_ACTIVE; \
87 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
88 knote_enqueue(kn); \
89} while(0)
90
91#define KN_HASHSIZE 64 /* XXX should be tunable */
92#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
93
94static struct fileops kqueueops = {
95 kqueue_read,
96 kqueue_write,
97 kqueue_ioctl,
98 kqueue_poll,
99 kqueue_stat,
100 kqueue_close
101};
102
103extern struct filterops so_rwfiltops[];
104extern struct filterops fifo_rwfiltops[];
105extern struct filterops pipe_rwfiltops[];
106extern struct filterops vn_rwfiltops[];
107
108static struct filterops kq_rwfiltops[] = {
109 { 1, filt_kqattach, filt_kqdetach, filt_kqueue },
110 { 1, filt_nullattach, NULL, NULL },
111};
112
113extern struct filterops aio_filtops;
114extern struct filterops sig_filtops;
115extern struct filterops vn_filtops;
116
117static struct filterops rwtype_filtops =
118 { 1, filt_rwtypattach, NULL, NULL };
119static struct filterops proc_filtops =
120 { 0, filt_procattach, filt_procdetach, filt_proc };
121
122/*
123 * XXX
124 * These must match the order of defines in <sys/file.h>
125 */
126static struct filterops *rwtypfilt_sw[] = {
127 NULL, /* 0 */
128 vn_rwfiltops, /* DTYPE_VNODE */
129 so_rwfiltops, /* DTYPE_SOCKET */
130 pipe_rwfiltops, /* DTYPE_PIPE */
131 fifo_rwfiltops, /* DTYPE_FIFO */
132 kq_rwfiltops, /* DTYPE_KQUEUE */
133};
134
135/*
136 * table for for all system-defined filters.
137 */
138static struct filterops *sysfilt_ops[] = {
139 &rwtype_filtops, /* EVFILT_READ */
140 &rwtype_filtops, /* EVFILT_WRITE */
141 &aio_filtops, /* EVFILT_AIO */
142 &vn_filtops, /* EVFILT_VNODE */
143 &proc_filtops, /* EVFILT_PROC */
144 &sig_filtops, /* EVFILT_SIGNAL */
145};
146
147static int
148filt_nullattach(struct knote *kn)
149{
150 return (ENXIO);
151}
152
153/*
154 * file-type specific attach routine for read/write filters
155 */
156static int
157filt_rwtypattach(struct knote *kn)
158{
159 struct filterops *fops;
160
161 fops = rwtypfilt_sw[kn->kn_fp->f_type];
162 if (fops == NULL)
163 return (EINVAL);
164 kn->kn_fop = &fops[~kn->kn_filter]; /* convert to 0-base index */
165 return (kn->kn_fop->f_attach(kn));
166}
167
168static int
169filt_kqattach(struct knote *kn)
170{
171 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
172
173 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext);
174 return (0);
175}
176
177static void
178filt_kqdetach(struct knote *kn)
179{
180 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
181
182 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext);
183}
184
185/*ARGSUSED*/
186static int
187filt_kqueue(struct knote *kn, long hint)
188{
189 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
190
191 kn->kn_data = kq->kq_count;
192 return (kn->kn_data > 0);
193}
194
195static int
196filt_procattach(struct knote *kn)
197{
198 struct proc *p;
199
200 p = pfind(kn->kn_id);
201 if (p == NULL)
202 return (ESRCH);
203 if (p_can(curproc, p, P_CAN_SEE, NULL))
204 return (EACCES);
205
206 kn->kn_ptr.p_proc = p;
207 kn->kn_flags |= EV_CLEAR; /* automatically set */
208
209 /*
210 * internal flag indicating registration done by kernel
211 */
212 if (kn->kn_flags & EV_FLAG1) {
213 kn->kn_data = kn->kn_sdata; /* ppid */
214 kn->kn_fflags = NOTE_CHILD;
215 kn->kn_flags &= ~EV_FLAG1;
216 }
217
218 /* XXX lock the proc here while adding to the list? */
219 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
220
221 return (0);
222}
223
224/*
225 * The knote may be attached to a different process, which may exit,
226 * leaving nothing for the knote to be attached to. So when the process
227 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
228 * it will be deleted when read out. However, as part of the knote deletion,
229 * this routine is called, so a check is needed to avoid actually performing
230 * a detach, because the original process does not exist any more.
231 */
232static void
233filt_procdetach(struct knote *kn)
234{
235 struct proc *p = kn->kn_ptr.p_proc;
236
237 if (kn->kn_status & KN_DETACHED)
238 return;
239
240 /* XXX locking? this might modify another process. */
241 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
242}
243
244static int
245filt_proc(struct knote *kn, long hint)
246{
247 u_int event;
248
249 /*
250 * mask off extra data
251 */
252 event = (u_int)hint & NOTE_PCTRLMASK;
253
254 /*
255 * if the user is interested in this event, record it.
256 */
257 if (kn->kn_sfflags & event)
258 kn->kn_fflags |= event;
259
260 /*
261 * process is gone, so flag the event as finished.
262 */
263 if (event == NOTE_EXIT) {
264 kn->kn_status |= KN_DETACHED;
265 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
266 return (1);
267 }
268
269 /*
270 * process forked, and user wants to track the new process,
271 * so attach a new knote to it, and immediately report an
272 * event with the parent's pid.
273 */
274 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) {
275 struct kevent kev;
276 int error;
277
278 /*
279 * register knote with new process.
280 */
281 kev.ident = hint & NOTE_PDATAMASK; /* pid */
282 kev.filter = kn->kn_filter;
283 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
284 kev.fflags = kn->kn_sfflags;
285 kev.data = kn->kn_id; /* parent */
286 kev.udata = kn->kn_kevent.udata; /* preserve udata */
287 error = kqueue_register(kn->kn_kq, &kev, NULL);
288 if (error)
289 kn->kn_fflags |= NOTE_TRACKERR;
290 }
291
292 return (kn->kn_fflags != 0);
293}
294
295int
296kqueue(struct proc *p, struct kqueue_args *uap)
297{
298 struct filedesc *fdp = p->p_fd;
299 struct kqueue *kq;
300 struct file *fp;
301 int fd, error;
302
303 error = falloc(p, &fp, &fd);
304 if (error)
305 return (error);
306 fp->f_flag = FREAD | FWRITE;
307 fp->f_type = DTYPE_KQUEUE;
308 fp->f_ops = &kqueueops;
309 kq = malloc(sizeof(struct kqueue), M_TEMP, M_WAITOK | M_ZERO);
310 TAILQ_INIT(&kq->kq_head);
311 fp->f_data = (caddr_t)kq;
312 p->p_retval[0] = fd;
313 if (fdp->fd_knlistsize < 0)
314 fdp->fd_knlistsize = 0; /* this process has a kq */
315 kq->kq_fdp = fdp;
316 return (error);
317}
318
319#ifndef _SYS_SYSPROTO_H_
320struct kevent_args {
321 int fd;
322 const struct kevent *changelist;
323 int nchanges;
324 struct kevent *eventlist;
325 int nevents;
326 const struct timespec *timeout;
327};
328#endif
329int
330kevent(struct proc *p, struct kevent_args *uap)
331{
332 struct filedesc* fdp = p->p_fd;
333 struct kevent *kevp;
334 struct kqueue *kq;
335 struct file *fp = NULL;
336 struct timespec ts;
337 int i, n, nerrors, error;
338
339 if (((u_int)uap->fd) >= fdp->fd_nfiles ||
340 (fp = fdp->fd_ofiles[uap->fd]) == NULL ||
341 (fp->f_type != DTYPE_KQUEUE))
342 return (EBADF);
343
344 fhold(fp);
345
346 if (uap->timeout != NULL) {
347 error = copyin(uap->timeout, &ts, sizeof(ts));
348 if (error)
349 goto done;
350 uap->timeout = &ts;
351 }
352
353 kq = (struct kqueue *)fp->f_data;
354 nerrors = 0;
355
356 while (uap->nchanges > 0) {
357 n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges;
358 error = copyin(uap->changelist, kq->kq_kev,
359 n * sizeof(struct kevent));
360 if (error)
361 goto done;
362 for (i = 0; i < n; i++) {
363 kevp = &kq->kq_kev[i];
364 kevp->flags &= ~EV_SYSFLAGS;
365 error = kqueue_register(kq, kevp, p);
366 if (error) {
367 if (uap->nevents != 0) {
368 kevp->flags = EV_ERROR;
369 kevp->data = error;
370 (void) copyout((caddr_t)kevp,
371 (caddr_t)uap->eventlist,
372 sizeof(*kevp));
373 uap->eventlist++;
374 uap->nevents--;
375 nerrors++;
376 } else {
377 goto done;
378 }
379 }
380 }
381 uap->nchanges -= n;
382 uap->changelist += n;
383 }
384 if (nerrors) {
385 p->p_retval[0] = nerrors;
386 error = 0;
387 goto done;
388 }
389
390 error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, p);
391done:
392 if (fp != NULL)
393 fdrop(fp, p);
394 return (error);
395}
396
397int
398kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
399{
400 struct filedesc *fdp = kq->kq_fdp;
401 struct filterops *fops;
402 struct file *fp = NULL;
403 struct knote *kn = NULL;
404 int s, error = 0;
405
406 if (kev->filter < 0) {
407 if (kev->filter + EVFILT_SYSCOUNT < 0)
408 return (EINVAL);
409 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
410 } else {
411 /*
412 * XXX
413 * filter attach routine is responsible for insuring that
414 * the identifier can be attached to it.
415 */
416 printf("unknown filter: %d\n", kev->filter);
417 return (EINVAL);
418 }
419
420 if (fops->f_isfd) {
421 /* validate descriptor */
422 if ((u_int)kev->ident >= fdp->fd_nfiles ||
423 (fp = fdp->fd_ofiles[kev->ident]) == NULL)
424 return (EBADF);
425 fhold(fp);
426
427 if (kev->ident < fdp->fd_knlistsize) {
428 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link)
429 if (kq == kn->kn_kq &&
430 kev->filter == kn->kn_filter)
431 break;
432 }
433 } else {
434 if (fdp->fd_knhashmask != 0) {
435 struct klist *list;
436
437 list = &fdp->fd_knhash[
438 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)];
439 SLIST_FOREACH(kn, list, kn_link)
440 if (kev->ident == kn->kn_id &&
441 kq == kn->kn_kq &&
442 kev->filter == kn->kn_filter)
443 break;
444 }
445 }
446
447 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
448 error = ENOENT;
449 goto done;
450 }
451
452 /*
453 * kn now contains the matching knote, or NULL if no match
454 */
455 if (kev->flags & EV_ADD) {
456
457 if (kn == NULL) {
458 kn = knote_alloc();
459 if (kn == NULL) {
460 error = ENOMEM;
461 goto done;
462 }
463 kn->kn_fp = fp;
464 kn->kn_kq = kq;
465 kn->kn_fop = fops;
466
467 /*
468 * apply reference count to knode structure, so
469 * do not release it at the end of this routine.
470 */
471 fp = NULL;
472
473 kn->kn_sfflags = kev->fflags;
474 kn->kn_sdata = kev->data;
475 kev->fflags = 0;
476 kev->data = 0;
477 kn->kn_kevent = *kev;
478
479 knote_attach(kn, fdp);
480 if ((error = fops->f_attach(kn)) != 0) {
481 knote_drop(kn, p);
482 goto done;
483 }
484 } else {
485 /*
486 * The user may change some filter values after the
487 * initial EV_ADD, but doing so will not reset any
488 * filter which have already been triggered.
489 */
490 kn->kn_sfflags = kev->fflags;
491 kn->kn_sdata = kev->data;
492 kn->kn_kevent.udata = kev->udata;
493 }
494
495 s = splhigh();
496 if (kn->kn_fop->f_event(kn, 0))
497 KNOTE_ACTIVATE(kn);
498 splx(s);
499
500 } else if (kev->flags & EV_DELETE) {
501 kn->kn_fop->f_detach(kn);
502 knote_drop(kn, p);
503 goto done;
504 }
505
506 if ((kev->flags & EV_DISABLE) &&
507 ((kn->kn_status & KN_DISABLED) == 0)) {
508 s = splhigh();
509 kn->kn_status |= KN_DISABLED;
510 splx(s);
511 }
512
513 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
514 s = splhigh();
515 kn->kn_status &= ~KN_DISABLED;
516 if ((kn->kn_status & KN_ACTIVE) &&
517 ((kn->kn_status & KN_QUEUED) == 0))
518 knote_enqueue(kn);
519 splx(s);
520 }
521
522done:
523 if (fp != NULL)
524 fdrop(fp, p);
525 return (error);
526}
527
528static int
529kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp,
530 const struct timespec *tsp, struct proc *p)
531{
532 struct kqueue *kq = (struct kqueue *)fp->f_data;
533 struct kevent *kevp;
534 struct timeval atv, rtv, ttv;
535 struct knote *kn, marker;
536 int s, count, timeout, nkev = 0, error = 0;
537
538 count = maxevents;
539 if (count == 0)
540 goto done;
541
542 if (tsp != NULL) {
543 TIMESPEC_TO_TIMEVAL(&atv, tsp);
544 if (itimerfix(&atv)) {
545 error = EINVAL;
546 goto done;
547 }
548 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
549 timeout = -1;
550 else
551 timeout = atv.tv_sec > 24 * 60 * 60 ?
552 24 * 60 * 60 * hz : tvtohz(&atv);
553 getmicrouptime(&rtv);
554 timevaladd(&atv, &rtv);
555 } else {
556 atv.tv_sec = 0;
557 atv.tv_usec = 0;
558 timeout = 0;
559 }
560 goto start;
561
562retry:
563 if (atv.tv_sec || atv.tv_usec) {
564 getmicrouptime(&rtv);
565 if (timevalcmp(&rtv, &atv, >=))
566 goto done;
567 ttv = atv;
568 timevalsub(&ttv, &rtv);
569 timeout = ttv.tv_sec > 24 * 60 * 60 ?
570 24 * 60 * 60 * hz : tvtohz(&ttv);
571 }
572
573start:
574 kevp = kq->kq_kev;
575 s = splhigh();
576 if (kq->kq_count == 0) {
577 if (timeout < 0) {
578 error = EWOULDBLOCK;
579 } else {
580 kq->kq_state |= KQ_SLEEP;
581 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout);
582 }
583 splx(s);
584 if (error == 0)
585 goto retry;
586 /* don't restart after signals... */
587 if (error == ERESTART)
588 error = EINTR;
589 else if (error == EWOULDBLOCK)
590 error = 0;
591 goto done;
592 }
593
594 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe);
595 while (count) {
596 kn = TAILQ_FIRST(&kq->kq_head);
597 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
598 if (kn == &marker) {
599 splx(s);
600 if (count == maxevents)
601 goto retry;
602 goto done;
603 }
604 if (kn->kn_status & KN_DISABLED) {
605 kn->kn_status &= ~KN_QUEUED;
606 kq->kq_count--;
607 continue;
608 }
609 if ((kn->kn_flags & EV_ONESHOT) == 0 &&
610 kn->kn_fop->f_event(kn, 0) == 0) {
611 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
612 kq->kq_count--;
613 continue;
614 }
615 *kevp = kn->kn_kevent;
616 kevp++;
617 nkev++;
618 if (kn->kn_flags & EV_ONESHOT) {
619 kn->kn_status &= ~KN_QUEUED;
620 kq->kq_count--;
621 splx(s);
622 kn->kn_fop->f_detach(kn);
623 knote_drop(kn, p);
624 s = splhigh();
625 } else if (kn->kn_flags & EV_CLEAR) {
626 kn->kn_data = 0;
627 kn->kn_fflags = 0;
628 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
629 kq->kq_count--;
630 } else {
631 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
632 }
633 count--;
634 if (nkev == KQ_NEVENTS) {
635 splx(s);
636 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
637 sizeof(struct kevent) * nkev);
638 ulistp += nkev;
639 nkev = 0;
640 kevp = kq->kq_kev;
641 s = splhigh();
642 if (error)
643 break;
644 }
645 }
646 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe);
647 splx(s);
648done:
649 if (nkev != 0)
650 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
651 sizeof(struct kevent) * nkev);
652 p->p_retval[0] = maxevents - count;
653 return (error);
654}
655
656/*
657 * XXX
658 * This could be expanded to call kqueue_scan, if desired.
659 */
660/*ARGSUSED*/
661static int
662kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred,
663 int flags, struct proc *p)
664{
665 return (ENXIO);
666}
667
668/*ARGSUSED*/
669static int
670kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred,
671 int flags, struct proc *p)
672{
673 return (ENXIO);
674}
675
676/*ARGSUSED*/
677static int
678kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p)
679{
680 return (ENOTTY);
681}
682
683/*ARGSUSED*/
684static int
685kqueue_poll(struct file *fp, int events, struct ucred *cred, struct proc *p)
686{
687 struct kqueue *kq = (struct kqueue *)fp->f_data;
688 int revents = 0;
689 int s = splnet();
690
691 if (events & (POLLIN | POLLRDNORM)) {
692 if (kq->kq_count) {
693 revents |= events & (POLLIN | POLLRDNORM);
694 } else {
695 selrecord(p, &kq->kq_sel);
696 kq->kq_state |= KQ_SEL;
697 }
698 }
699 splx(s);
700 return (revents);
701}
702
703/*ARGSUSED*/
704static int
705kqueue_stat(struct file *fp, struct stat *st, struct proc *p)
706{
707 struct kqueue *kq = (struct kqueue *)fp->f_data;
708
709 bzero((void *)st, sizeof(*st));
710 st->st_size = kq->kq_count;
711 st->st_blksize = sizeof(struct kevent);
712 st->st_mode = S_IFIFO;
713 return (0);
714}
715
716/*ARGSUSED*/
717static int
718kqueue_close(struct file *fp, struct proc *p)
719{
720 struct kqueue *kq = (struct kqueue *)fp->f_data;
721 struct filedesc *fdp = p->p_fd;
722 struct knote **knp, *kn, *kn0;
723 int i;
724
725 for (i = 0; i < fdp->fd_knlistsize; i++) {
726 knp = &SLIST_FIRST(&fdp->fd_knlist[i]);
727 kn = *knp;
728 while (kn != NULL) {
729 kn0 = SLIST_NEXT(kn, kn_link);
730 if (kq == kn->kn_kq) {
731 kn->kn_fop->f_detach(kn);
732 fdrop(kn->kn_fp, p);
733 knote_free(kn);
734 *knp = kn0;
735 } else {
736 knp = &SLIST_NEXT(kn, kn_link);
737 }
738 kn = kn0;
739 }
740 }
741 if (fdp->fd_knhashmask != 0) {
742 for (i = 0; i < fdp->fd_knhashmask + 1; i++) {
743 knp = &SLIST_FIRST(&fdp->fd_knhash[i]);
744 kn = *knp;
745 while (kn != NULL) {
746 kn0 = SLIST_NEXT(kn, kn_link);
747 if (kq == kn->kn_kq) {
748 kn->kn_fop->f_detach(kn);
749 /* XXX non-fd release of kn->kn_ptr */
750 knote_free(kn);
751 *knp = kn0;
752 } else {
753 knp = &SLIST_NEXT(kn, kn_link);
754 }
755 kn = kn0;
756 }
757 }
758 }
759 free(kq, M_TEMP);
760 fp->f_data = NULL;
761
762 return (0);
763}
764
765static void
766kqueue_wakeup(struct kqueue *kq)
767{
768
769 if (kq->kq_state & KQ_SLEEP) {
770 kq->kq_state &= ~KQ_SLEEP;
771 wakeup(kq);
772 }
773 if (kq->kq_state & KQ_SEL) {
774 kq->kq_state &= ~KQ_SEL;
775 selwakeup(&kq->kq_sel);
776 }
777 KNOTE(&kq->kq_sel.si_note, 0);
778}
779
780/*
781 * walk down a list of knotes, activating them if their event has triggered.
782 */
783void
784knote(struct klist *list, long hint)
785{
786 struct knote *kn;
787
788 SLIST_FOREACH(kn, list, kn_selnext)
789 if (kn->kn_fop->f_event(kn, hint))
790 KNOTE_ACTIVATE(kn);
791}
792
793/*
794 * remove all knotes from a specified klist
795 */
796void
797knote_remove(struct proc *p, struct klist *list)
798{
799 struct knote *kn;
800
801 while ((kn = SLIST_FIRST(list)) != NULL) {
802 kn->kn_fop->f_detach(kn);
803 knote_drop(kn, p);
804 }
805}
806
807/*
808 * remove all knotes referencing a specified fd
809 */
810void
811knote_fdclose(struct proc *p, int fd)
812{
813 struct filedesc *fdp = p->p_fd;
814 struct klist *list = &fdp->fd_knlist[fd];
815
816 knote_remove(p, list);
817}
818
819static void
820knote_attach(struct knote *kn, struct filedesc *fdp)
821{
822 struct klist *list;
823 int size;
824
825 if (! kn->kn_fop->f_isfd) {
826 if (fdp->fd_knhashmask == 0)
827 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP,
828 &fdp->fd_knhashmask);
829 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
830 goto done;
831 }
832
833 if (fdp->fd_knlistsize <= kn->kn_id) {
834 size = fdp->fd_knlistsize;
835 while (size <= kn->kn_id)
836 size += KQEXTENT;
837 MALLOC(list, struct klist *,
838 size * sizeof(struct klist *), M_TEMP, M_WAITOK);
839 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list,
840 fdp->fd_knlistsize * sizeof(struct klist *));
841 bzero((caddr_t)list +
842 fdp->fd_knlistsize * sizeof(struct klist *),
843 (size - fdp->fd_knlistsize) * sizeof(struct klist *));
844 if (fdp->fd_knlist != NULL)
845 FREE(fdp->fd_knlist, M_TEMP);
846 fdp->fd_knlistsize = size;
847 fdp->fd_knlist = list;
848 }
849 list = &fdp->fd_knlist[kn->kn_id];
850done:
851 SLIST_INSERT_HEAD(list, kn, kn_link);
852 kn->kn_status = 0;
853}
854
855/*
856 * should be called at spl == 0, since we don't want to hold spl
857 * while calling fdrop and free.
858 */
859static void
860knote_drop(struct knote *kn, struct proc *p)
861{
862 struct filedesc *fdp = p->p_fd;
863 struct klist *list;
864
865 if (kn->kn_fop->f_isfd)
866 list = &fdp->fd_knlist[kn->kn_id];
867 else
868 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
869
870 SLIST_REMOVE(list, kn, knote, kn_link);
871 if (kn->kn_status & KN_QUEUED)
872 knote_dequeue(kn);
873 if (kn->kn_fop->f_isfd)
874 fdrop(kn->kn_fp, p);
875 knote_free(kn);
876}
877
878
879static void
880knote_enqueue(struct knote *kn)
881{
882 struct kqueue *kq = kn->kn_kq;
883 int s = splhigh();
884
885 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
886
887 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
888 kn->kn_status |= KN_QUEUED;
889 kq->kq_count++;
890 splx(s);
891 kqueue_wakeup(kq);
892}
893
894static void
895knote_dequeue(struct knote *kn)
896{
897 struct kqueue *kq = kn->kn_kq;
898 int s = splhigh();
899
900 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
901
902 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
903 kn->kn_status &= ~KN_QUEUED;
904 kq->kq_count--;
905 splx(s);
906}
907
908static void
909knote_init(void)
910{
911 knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1);
912}
913SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL)
914
915static struct knote *
916knote_alloc(void)
917{
918 return ((struct knote *)zalloc(knote_zone));
919}
920
921static void
922knote_free(struct knote *kn)
923{
924 zfree(knote_zone, kn);
925}
2 * Copyright (c) 1999,2000 Jonathan Lemon <jlemon@FreeBSD.org>
3 * All rights reserved.
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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/kern/kern_event.c 70834 2001-01-09 04:33:49Z wollman $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/kernel.h>
32#include <sys/proc.h>
33#include <sys/malloc.h>
34#include <sys/unistd.h>
35#include <sys/file.h>
36#include <sys/fcntl.h>
37#include <sys/selinfo.h>
38#include <sys/queue.h>
39#include <sys/event.h>
40#include <sys/eventvar.h>
41#include <sys/poll.h>
42#include <sys/protosw.h>
43#include <sys/socket.h>
44#include <sys/socketvar.h>
45#include <sys/stat.h>
46#include <sys/sysproto.h>
47#include <sys/uio.h>
48
49#include <vm/vm_zone.h>
50
51static int filt_nullattach(struct knote *kn);
52static int filt_rwtypattach(struct knote *kn);
53static int filt_kqattach(struct knote *kn);
54static void filt_kqdetach(struct knote *kn);
55static int filt_kqueue(struct knote *kn, long hint);
56static int filt_procattach(struct knote *kn);
57static void filt_procdetach(struct knote *kn);
58static int filt_proc(struct knote *kn, long hint);
59
60static int kqueue_scan(struct file *fp, int maxevents,
61 struct kevent *ulistp, const struct timespec *timeout,
62 struct proc *p);
63static int kqueue_read(struct file *fp, struct uio *uio,
64 struct ucred *cred, int flags, struct proc *p);
65static int kqueue_write(struct file *fp, struct uio *uio,
66 struct ucred *cred, int flags, struct proc *p);
67static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data,
68 struct proc *p);
69static int kqueue_poll(struct file *fp, int events, struct ucred *cred,
70 struct proc *p);
71static int kqueue_stat(struct file *fp, struct stat *st, struct proc *p);
72static int kqueue_close(struct file *fp, struct proc *p);
73static void kqueue_wakeup(struct kqueue *kq);
74
75static void knote_attach(struct knote *kn, struct filedesc *fdp);
76static void knote_drop(struct knote *kn, struct proc *p);
77static void knote_enqueue(struct knote *kn);
78static void knote_dequeue(struct knote *kn);
79static void knote_init(void);
80static struct knote *knote_alloc(void);
81static void knote_free(struct knote *kn);
82
83static vm_zone_t knote_zone;
84
85#define KNOTE_ACTIVATE(kn) do { \
86 kn->kn_status |= KN_ACTIVE; \
87 if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \
88 knote_enqueue(kn); \
89} while(0)
90
91#define KN_HASHSIZE 64 /* XXX should be tunable */
92#define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask))
93
94static struct fileops kqueueops = {
95 kqueue_read,
96 kqueue_write,
97 kqueue_ioctl,
98 kqueue_poll,
99 kqueue_stat,
100 kqueue_close
101};
102
103extern struct filterops so_rwfiltops[];
104extern struct filterops fifo_rwfiltops[];
105extern struct filterops pipe_rwfiltops[];
106extern struct filterops vn_rwfiltops[];
107
108static struct filterops kq_rwfiltops[] = {
109 { 1, filt_kqattach, filt_kqdetach, filt_kqueue },
110 { 1, filt_nullattach, NULL, NULL },
111};
112
113extern struct filterops aio_filtops;
114extern struct filterops sig_filtops;
115extern struct filterops vn_filtops;
116
117static struct filterops rwtype_filtops =
118 { 1, filt_rwtypattach, NULL, NULL };
119static struct filterops proc_filtops =
120 { 0, filt_procattach, filt_procdetach, filt_proc };
121
122/*
123 * XXX
124 * These must match the order of defines in <sys/file.h>
125 */
126static struct filterops *rwtypfilt_sw[] = {
127 NULL, /* 0 */
128 vn_rwfiltops, /* DTYPE_VNODE */
129 so_rwfiltops, /* DTYPE_SOCKET */
130 pipe_rwfiltops, /* DTYPE_PIPE */
131 fifo_rwfiltops, /* DTYPE_FIFO */
132 kq_rwfiltops, /* DTYPE_KQUEUE */
133};
134
135/*
136 * table for for all system-defined filters.
137 */
138static struct filterops *sysfilt_ops[] = {
139 &rwtype_filtops, /* EVFILT_READ */
140 &rwtype_filtops, /* EVFILT_WRITE */
141 &aio_filtops, /* EVFILT_AIO */
142 &vn_filtops, /* EVFILT_VNODE */
143 &proc_filtops, /* EVFILT_PROC */
144 &sig_filtops, /* EVFILT_SIGNAL */
145};
146
147static int
148filt_nullattach(struct knote *kn)
149{
150 return (ENXIO);
151}
152
153/*
154 * file-type specific attach routine for read/write filters
155 */
156static int
157filt_rwtypattach(struct knote *kn)
158{
159 struct filterops *fops;
160
161 fops = rwtypfilt_sw[kn->kn_fp->f_type];
162 if (fops == NULL)
163 return (EINVAL);
164 kn->kn_fop = &fops[~kn->kn_filter]; /* convert to 0-base index */
165 return (kn->kn_fop->f_attach(kn));
166}
167
168static int
169filt_kqattach(struct knote *kn)
170{
171 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
172
173 SLIST_INSERT_HEAD(&kq->kq_sel.si_note, kn, kn_selnext);
174 return (0);
175}
176
177static void
178filt_kqdetach(struct knote *kn)
179{
180 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
181
182 SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext);
183}
184
185/*ARGSUSED*/
186static int
187filt_kqueue(struct knote *kn, long hint)
188{
189 struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data;
190
191 kn->kn_data = kq->kq_count;
192 return (kn->kn_data > 0);
193}
194
195static int
196filt_procattach(struct knote *kn)
197{
198 struct proc *p;
199
200 p = pfind(kn->kn_id);
201 if (p == NULL)
202 return (ESRCH);
203 if (p_can(curproc, p, P_CAN_SEE, NULL))
204 return (EACCES);
205
206 kn->kn_ptr.p_proc = p;
207 kn->kn_flags |= EV_CLEAR; /* automatically set */
208
209 /*
210 * internal flag indicating registration done by kernel
211 */
212 if (kn->kn_flags & EV_FLAG1) {
213 kn->kn_data = kn->kn_sdata; /* ppid */
214 kn->kn_fflags = NOTE_CHILD;
215 kn->kn_flags &= ~EV_FLAG1;
216 }
217
218 /* XXX lock the proc here while adding to the list? */
219 SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext);
220
221 return (0);
222}
223
224/*
225 * The knote may be attached to a different process, which may exit,
226 * leaving nothing for the knote to be attached to. So when the process
227 * exits, the knote is marked as DETACHED and also flagged as ONESHOT so
228 * it will be deleted when read out. However, as part of the knote deletion,
229 * this routine is called, so a check is needed to avoid actually performing
230 * a detach, because the original process does not exist any more.
231 */
232static void
233filt_procdetach(struct knote *kn)
234{
235 struct proc *p = kn->kn_ptr.p_proc;
236
237 if (kn->kn_status & KN_DETACHED)
238 return;
239
240 /* XXX locking? this might modify another process. */
241 SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext);
242}
243
244static int
245filt_proc(struct knote *kn, long hint)
246{
247 u_int event;
248
249 /*
250 * mask off extra data
251 */
252 event = (u_int)hint & NOTE_PCTRLMASK;
253
254 /*
255 * if the user is interested in this event, record it.
256 */
257 if (kn->kn_sfflags & event)
258 kn->kn_fflags |= event;
259
260 /*
261 * process is gone, so flag the event as finished.
262 */
263 if (event == NOTE_EXIT) {
264 kn->kn_status |= KN_DETACHED;
265 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
266 return (1);
267 }
268
269 /*
270 * process forked, and user wants to track the new process,
271 * so attach a new knote to it, and immediately report an
272 * event with the parent's pid.
273 */
274 if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) {
275 struct kevent kev;
276 int error;
277
278 /*
279 * register knote with new process.
280 */
281 kev.ident = hint & NOTE_PDATAMASK; /* pid */
282 kev.filter = kn->kn_filter;
283 kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1;
284 kev.fflags = kn->kn_sfflags;
285 kev.data = kn->kn_id; /* parent */
286 kev.udata = kn->kn_kevent.udata; /* preserve udata */
287 error = kqueue_register(kn->kn_kq, &kev, NULL);
288 if (error)
289 kn->kn_fflags |= NOTE_TRACKERR;
290 }
291
292 return (kn->kn_fflags != 0);
293}
294
295int
296kqueue(struct proc *p, struct kqueue_args *uap)
297{
298 struct filedesc *fdp = p->p_fd;
299 struct kqueue *kq;
300 struct file *fp;
301 int fd, error;
302
303 error = falloc(p, &fp, &fd);
304 if (error)
305 return (error);
306 fp->f_flag = FREAD | FWRITE;
307 fp->f_type = DTYPE_KQUEUE;
308 fp->f_ops = &kqueueops;
309 kq = malloc(sizeof(struct kqueue), M_TEMP, M_WAITOK | M_ZERO);
310 TAILQ_INIT(&kq->kq_head);
311 fp->f_data = (caddr_t)kq;
312 p->p_retval[0] = fd;
313 if (fdp->fd_knlistsize < 0)
314 fdp->fd_knlistsize = 0; /* this process has a kq */
315 kq->kq_fdp = fdp;
316 return (error);
317}
318
319#ifndef _SYS_SYSPROTO_H_
320struct kevent_args {
321 int fd;
322 const struct kevent *changelist;
323 int nchanges;
324 struct kevent *eventlist;
325 int nevents;
326 const struct timespec *timeout;
327};
328#endif
329int
330kevent(struct proc *p, struct kevent_args *uap)
331{
332 struct filedesc* fdp = p->p_fd;
333 struct kevent *kevp;
334 struct kqueue *kq;
335 struct file *fp = NULL;
336 struct timespec ts;
337 int i, n, nerrors, error;
338
339 if (((u_int)uap->fd) >= fdp->fd_nfiles ||
340 (fp = fdp->fd_ofiles[uap->fd]) == NULL ||
341 (fp->f_type != DTYPE_KQUEUE))
342 return (EBADF);
343
344 fhold(fp);
345
346 if (uap->timeout != NULL) {
347 error = copyin(uap->timeout, &ts, sizeof(ts));
348 if (error)
349 goto done;
350 uap->timeout = &ts;
351 }
352
353 kq = (struct kqueue *)fp->f_data;
354 nerrors = 0;
355
356 while (uap->nchanges > 0) {
357 n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges;
358 error = copyin(uap->changelist, kq->kq_kev,
359 n * sizeof(struct kevent));
360 if (error)
361 goto done;
362 for (i = 0; i < n; i++) {
363 kevp = &kq->kq_kev[i];
364 kevp->flags &= ~EV_SYSFLAGS;
365 error = kqueue_register(kq, kevp, p);
366 if (error) {
367 if (uap->nevents != 0) {
368 kevp->flags = EV_ERROR;
369 kevp->data = error;
370 (void) copyout((caddr_t)kevp,
371 (caddr_t)uap->eventlist,
372 sizeof(*kevp));
373 uap->eventlist++;
374 uap->nevents--;
375 nerrors++;
376 } else {
377 goto done;
378 }
379 }
380 }
381 uap->nchanges -= n;
382 uap->changelist += n;
383 }
384 if (nerrors) {
385 p->p_retval[0] = nerrors;
386 error = 0;
387 goto done;
388 }
389
390 error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, p);
391done:
392 if (fp != NULL)
393 fdrop(fp, p);
394 return (error);
395}
396
397int
398kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p)
399{
400 struct filedesc *fdp = kq->kq_fdp;
401 struct filterops *fops;
402 struct file *fp = NULL;
403 struct knote *kn = NULL;
404 int s, error = 0;
405
406 if (kev->filter < 0) {
407 if (kev->filter + EVFILT_SYSCOUNT < 0)
408 return (EINVAL);
409 fops = sysfilt_ops[~kev->filter]; /* to 0-base index */
410 } else {
411 /*
412 * XXX
413 * filter attach routine is responsible for insuring that
414 * the identifier can be attached to it.
415 */
416 printf("unknown filter: %d\n", kev->filter);
417 return (EINVAL);
418 }
419
420 if (fops->f_isfd) {
421 /* validate descriptor */
422 if ((u_int)kev->ident >= fdp->fd_nfiles ||
423 (fp = fdp->fd_ofiles[kev->ident]) == NULL)
424 return (EBADF);
425 fhold(fp);
426
427 if (kev->ident < fdp->fd_knlistsize) {
428 SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link)
429 if (kq == kn->kn_kq &&
430 kev->filter == kn->kn_filter)
431 break;
432 }
433 } else {
434 if (fdp->fd_knhashmask != 0) {
435 struct klist *list;
436
437 list = &fdp->fd_knhash[
438 KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)];
439 SLIST_FOREACH(kn, list, kn_link)
440 if (kev->ident == kn->kn_id &&
441 kq == kn->kn_kq &&
442 kev->filter == kn->kn_filter)
443 break;
444 }
445 }
446
447 if (kn == NULL && ((kev->flags & EV_ADD) == 0)) {
448 error = ENOENT;
449 goto done;
450 }
451
452 /*
453 * kn now contains the matching knote, or NULL if no match
454 */
455 if (kev->flags & EV_ADD) {
456
457 if (kn == NULL) {
458 kn = knote_alloc();
459 if (kn == NULL) {
460 error = ENOMEM;
461 goto done;
462 }
463 kn->kn_fp = fp;
464 kn->kn_kq = kq;
465 kn->kn_fop = fops;
466
467 /*
468 * apply reference count to knode structure, so
469 * do not release it at the end of this routine.
470 */
471 fp = NULL;
472
473 kn->kn_sfflags = kev->fflags;
474 kn->kn_sdata = kev->data;
475 kev->fflags = 0;
476 kev->data = 0;
477 kn->kn_kevent = *kev;
478
479 knote_attach(kn, fdp);
480 if ((error = fops->f_attach(kn)) != 0) {
481 knote_drop(kn, p);
482 goto done;
483 }
484 } else {
485 /*
486 * The user may change some filter values after the
487 * initial EV_ADD, but doing so will not reset any
488 * filter which have already been triggered.
489 */
490 kn->kn_sfflags = kev->fflags;
491 kn->kn_sdata = kev->data;
492 kn->kn_kevent.udata = kev->udata;
493 }
494
495 s = splhigh();
496 if (kn->kn_fop->f_event(kn, 0))
497 KNOTE_ACTIVATE(kn);
498 splx(s);
499
500 } else if (kev->flags & EV_DELETE) {
501 kn->kn_fop->f_detach(kn);
502 knote_drop(kn, p);
503 goto done;
504 }
505
506 if ((kev->flags & EV_DISABLE) &&
507 ((kn->kn_status & KN_DISABLED) == 0)) {
508 s = splhigh();
509 kn->kn_status |= KN_DISABLED;
510 splx(s);
511 }
512
513 if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) {
514 s = splhigh();
515 kn->kn_status &= ~KN_DISABLED;
516 if ((kn->kn_status & KN_ACTIVE) &&
517 ((kn->kn_status & KN_QUEUED) == 0))
518 knote_enqueue(kn);
519 splx(s);
520 }
521
522done:
523 if (fp != NULL)
524 fdrop(fp, p);
525 return (error);
526}
527
528static int
529kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp,
530 const struct timespec *tsp, struct proc *p)
531{
532 struct kqueue *kq = (struct kqueue *)fp->f_data;
533 struct kevent *kevp;
534 struct timeval atv, rtv, ttv;
535 struct knote *kn, marker;
536 int s, count, timeout, nkev = 0, error = 0;
537
538 count = maxevents;
539 if (count == 0)
540 goto done;
541
542 if (tsp != NULL) {
543 TIMESPEC_TO_TIMEVAL(&atv, tsp);
544 if (itimerfix(&atv)) {
545 error = EINVAL;
546 goto done;
547 }
548 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
549 timeout = -1;
550 else
551 timeout = atv.tv_sec > 24 * 60 * 60 ?
552 24 * 60 * 60 * hz : tvtohz(&atv);
553 getmicrouptime(&rtv);
554 timevaladd(&atv, &rtv);
555 } else {
556 atv.tv_sec = 0;
557 atv.tv_usec = 0;
558 timeout = 0;
559 }
560 goto start;
561
562retry:
563 if (atv.tv_sec || atv.tv_usec) {
564 getmicrouptime(&rtv);
565 if (timevalcmp(&rtv, &atv, >=))
566 goto done;
567 ttv = atv;
568 timevalsub(&ttv, &rtv);
569 timeout = ttv.tv_sec > 24 * 60 * 60 ?
570 24 * 60 * 60 * hz : tvtohz(&ttv);
571 }
572
573start:
574 kevp = kq->kq_kev;
575 s = splhigh();
576 if (kq->kq_count == 0) {
577 if (timeout < 0) {
578 error = EWOULDBLOCK;
579 } else {
580 kq->kq_state |= KQ_SLEEP;
581 error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout);
582 }
583 splx(s);
584 if (error == 0)
585 goto retry;
586 /* don't restart after signals... */
587 if (error == ERESTART)
588 error = EINTR;
589 else if (error == EWOULDBLOCK)
590 error = 0;
591 goto done;
592 }
593
594 TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe);
595 while (count) {
596 kn = TAILQ_FIRST(&kq->kq_head);
597 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
598 if (kn == &marker) {
599 splx(s);
600 if (count == maxevents)
601 goto retry;
602 goto done;
603 }
604 if (kn->kn_status & KN_DISABLED) {
605 kn->kn_status &= ~KN_QUEUED;
606 kq->kq_count--;
607 continue;
608 }
609 if ((kn->kn_flags & EV_ONESHOT) == 0 &&
610 kn->kn_fop->f_event(kn, 0) == 0) {
611 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
612 kq->kq_count--;
613 continue;
614 }
615 *kevp = kn->kn_kevent;
616 kevp++;
617 nkev++;
618 if (kn->kn_flags & EV_ONESHOT) {
619 kn->kn_status &= ~KN_QUEUED;
620 kq->kq_count--;
621 splx(s);
622 kn->kn_fop->f_detach(kn);
623 knote_drop(kn, p);
624 s = splhigh();
625 } else if (kn->kn_flags & EV_CLEAR) {
626 kn->kn_data = 0;
627 kn->kn_fflags = 0;
628 kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE);
629 kq->kq_count--;
630 } else {
631 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
632 }
633 count--;
634 if (nkev == KQ_NEVENTS) {
635 splx(s);
636 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
637 sizeof(struct kevent) * nkev);
638 ulistp += nkev;
639 nkev = 0;
640 kevp = kq->kq_kev;
641 s = splhigh();
642 if (error)
643 break;
644 }
645 }
646 TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe);
647 splx(s);
648done:
649 if (nkev != 0)
650 error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp,
651 sizeof(struct kevent) * nkev);
652 p->p_retval[0] = maxevents - count;
653 return (error);
654}
655
656/*
657 * XXX
658 * This could be expanded to call kqueue_scan, if desired.
659 */
660/*ARGSUSED*/
661static int
662kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred,
663 int flags, struct proc *p)
664{
665 return (ENXIO);
666}
667
668/*ARGSUSED*/
669static int
670kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred,
671 int flags, struct proc *p)
672{
673 return (ENXIO);
674}
675
676/*ARGSUSED*/
677static int
678kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p)
679{
680 return (ENOTTY);
681}
682
683/*ARGSUSED*/
684static int
685kqueue_poll(struct file *fp, int events, struct ucred *cred, struct proc *p)
686{
687 struct kqueue *kq = (struct kqueue *)fp->f_data;
688 int revents = 0;
689 int s = splnet();
690
691 if (events & (POLLIN | POLLRDNORM)) {
692 if (kq->kq_count) {
693 revents |= events & (POLLIN | POLLRDNORM);
694 } else {
695 selrecord(p, &kq->kq_sel);
696 kq->kq_state |= KQ_SEL;
697 }
698 }
699 splx(s);
700 return (revents);
701}
702
703/*ARGSUSED*/
704static int
705kqueue_stat(struct file *fp, struct stat *st, struct proc *p)
706{
707 struct kqueue *kq = (struct kqueue *)fp->f_data;
708
709 bzero((void *)st, sizeof(*st));
710 st->st_size = kq->kq_count;
711 st->st_blksize = sizeof(struct kevent);
712 st->st_mode = S_IFIFO;
713 return (0);
714}
715
716/*ARGSUSED*/
717static int
718kqueue_close(struct file *fp, struct proc *p)
719{
720 struct kqueue *kq = (struct kqueue *)fp->f_data;
721 struct filedesc *fdp = p->p_fd;
722 struct knote **knp, *kn, *kn0;
723 int i;
724
725 for (i = 0; i < fdp->fd_knlistsize; i++) {
726 knp = &SLIST_FIRST(&fdp->fd_knlist[i]);
727 kn = *knp;
728 while (kn != NULL) {
729 kn0 = SLIST_NEXT(kn, kn_link);
730 if (kq == kn->kn_kq) {
731 kn->kn_fop->f_detach(kn);
732 fdrop(kn->kn_fp, p);
733 knote_free(kn);
734 *knp = kn0;
735 } else {
736 knp = &SLIST_NEXT(kn, kn_link);
737 }
738 kn = kn0;
739 }
740 }
741 if (fdp->fd_knhashmask != 0) {
742 for (i = 0; i < fdp->fd_knhashmask + 1; i++) {
743 knp = &SLIST_FIRST(&fdp->fd_knhash[i]);
744 kn = *knp;
745 while (kn != NULL) {
746 kn0 = SLIST_NEXT(kn, kn_link);
747 if (kq == kn->kn_kq) {
748 kn->kn_fop->f_detach(kn);
749 /* XXX non-fd release of kn->kn_ptr */
750 knote_free(kn);
751 *knp = kn0;
752 } else {
753 knp = &SLIST_NEXT(kn, kn_link);
754 }
755 kn = kn0;
756 }
757 }
758 }
759 free(kq, M_TEMP);
760 fp->f_data = NULL;
761
762 return (0);
763}
764
765static void
766kqueue_wakeup(struct kqueue *kq)
767{
768
769 if (kq->kq_state & KQ_SLEEP) {
770 kq->kq_state &= ~KQ_SLEEP;
771 wakeup(kq);
772 }
773 if (kq->kq_state & KQ_SEL) {
774 kq->kq_state &= ~KQ_SEL;
775 selwakeup(&kq->kq_sel);
776 }
777 KNOTE(&kq->kq_sel.si_note, 0);
778}
779
780/*
781 * walk down a list of knotes, activating them if their event has triggered.
782 */
783void
784knote(struct klist *list, long hint)
785{
786 struct knote *kn;
787
788 SLIST_FOREACH(kn, list, kn_selnext)
789 if (kn->kn_fop->f_event(kn, hint))
790 KNOTE_ACTIVATE(kn);
791}
792
793/*
794 * remove all knotes from a specified klist
795 */
796void
797knote_remove(struct proc *p, struct klist *list)
798{
799 struct knote *kn;
800
801 while ((kn = SLIST_FIRST(list)) != NULL) {
802 kn->kn_fop->f_detach(kn);
803 knote_drop(kn, p);
804 }
805}
806
807/*
808 * remove all knotes referencing a specified fd
809 */
810void
811knote_fdclose(struct proc *p, int fd)
812{
813 struct filedesc *fdp = p->p_fd;
814 struct klist *list = &fdp->fd_knlist[fd];
815
816 knote_remove(p, list);
817}
818
819static void
820knote_attach(struct knote *kn, struct filedesc *fdp)
821{
822 struct klist *list;
823 int size;
824
825 if (! kn->kn_fop->f_isfd) {
826 if (fdp->fd_knhashmask == 0)
827 fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP,
828 &fdp->fd_knhashmask);
829 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
830 goto done;
831 }
832
833 if (fdp->fd_knlistsize <= kn->kn_id) {
834 size = fdp->fd_knlistsize;
835 while (size <= kn->kn_id)
836 size += KQEXTENT;
837 MALLOC(list, struct klist *,
838 size * sizeof(struct klist *), M_TEMP, M_WAITOK);
839 bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list,
840 fdp->fd_knlistsize * sizeof(struct klist *));
841 bzero((caddr_t)list +
842 fdp->fd_knlistsize * sizeof(struct klist *),
843 (size - fdp->fd_knlistsize) * sizeof(struct klist *));
844 if (fdp->fd_knlist != NULL)
845 FREE(fdp->fd_knlist, M_TEMP);
846 fdp->fd_knlistsize = size;
847 fdp->fd_knlist = list;
848 }
849 list = &fdp->fd_knlist[kn->kn_id];
850done:
851 SLIST_INSERT_HEAD(list, kn, kn_link);
852 kn->kn_status = 0;
853}
854
855/*
856 * should be called at spl == 0, since we don't want to hold spl
857 * while calling fdrop and free.
858 */
859static void
860knote_drop(struct knote *kn, struct proc *p)
861{
862 struct filedesc *fdp = p->p_fd;
863 struct klist *list;
864
865 if (kn->kn_fop->f_isfd)
866 list = &fdp->fd_knlist[kn->kn_id];
867 else
868 list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)];
869
870 SLIST_REMOVE(list, kn, knote, kn_link);
871 if (kn->kn_status & KN_QUEUED)
872 knote_dequeue(kn);
873 if (kn->kn_fop->f_isfd)
874 fdrop(kn->kn_fp, p);
875 knote_free(kn);
876}
877
878
879static void
880knote_enqueue(struct knote *kn)
881{
882 struct kqueue *kq = kn->kn_kq;
883 int s = splhigh();
884
885 KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued"));
886
887 TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe);
888 kn->kn_status |= KN_QUEUED;
889 kq->kq_count++;
890 splx(s);
891 kqueue_wakeup(kq);
892}
893
894static void
895knote_dequeue(struct knote *kn)
896{
897 struct kqueue *kq = kn->kn_kq;
898 int s = splhigh();
899
900 KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued"));
901
902 TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe);
903 kn->kn_status &= ~KN_QUEUED;
904 kq->kq_count--;
905 splx(s);
906}
907
908static void
909knote_init(void)
910{
911 knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1);
912}
913SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL)
914
915static struct knote *
916knote_alloc(void)
917{
918 return ((struct knote *)zalloc(knote_zone));
919}
920
921static void
922knote_free(struct knote *kn)
923{
924 zfree(knote_zone, kn);
925}