1 /* $NetBSD: sys_mqueue.c,v 1.16 2009/04/11 23:05:26 christos Exp $ */
4 * Copyright (c) 2007, 2008 Mindaugas Rasiukevicius <rmind at NetBSD org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR 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
30 * Implementation of POSIX message queues.
31 * Defined in the Base Definitions volume of IEEE Std 1003.1-2001.
35 * Global list of message queues (mqueue_head) and proc_t::p_mqueue_cnt
36 * counter are protected by mqlist_mtx lock. The very message queue and
37 * its members are protected by mqueue::mq_mtx.
44 #include <sys/param.h>
45 #include <sys/types.h>
46 #include <sys/errno.h>
47 #include <sys/fcntl.h>
49 #include <sys/filedesc.h>
50 #include <sys/ucred.h>
52 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/mqueue.h>
56 #include <sys/queue.h>
57 #include <sys/event.h>
58 #include <sys/serialize.h>
59 #include <sys/signal.h>
60 #include <sys/signalvar.h>
61 #include <sys/spinlock.h>
62 #include <sys/spinlock2.h>
64 #include <sys/stdbool.h>
65 #include <sys/sysctl.h>
66 #include <sys/sysproto.h>
67 #include <sys/systm.h>
69 #include <sys/unistd.h>
70 #include <sys/vnode.h>
72 /* System-wide limits. */
73 static u_int mq_open_max = MQ_OPEN_MAX;
74 static u_int mq_prio_max = MQ_PRIO_MAX;
75 static u_int mq_max_msgsize = 16 * MQ_DEF_MSGSIZE;
76 static u_int mq_def_maxmsg = 32;
77 static u_int mq_max_maxmsg = 16 * 32;
79 struct lock mqlist_mtx;
80 static LIST_HEAD(, mqueue) mqueue_head =
81 LIST_HEAD_INITIALIZER(mqueue_head);
83 typedef struct file file_t; /* XXX: Should we put this in sys/types.h ? */
85 /* Function prototypes */
86 static int mq_stat_fop(file_t *, struct stat *, struct ucred *cred);
87 static int mq_close_fop(file_t *);
88 static int mq_kqfilter_fop(struct file *fp, struct knote *kn);
89 static void mqfilter_read_detach(struct knote *kn);
90 static void mqfilter_write_detach(struct knote *kn);
91 static int mqfilter_read(struct knote *kn, long hint);
92 static int mqfilter_write(struct knote *kn, long hint);
94 /* Some time-related utility functions */
95 static int tstohz(const struct timespec *ts);
97 /* File operations vector */
98 static struct fileops mqops = {
99 .fo_read = badfo_readwrite,
100 .fo_write = badfo_readwrite,
101 .fo_ioctl = badfo_ioctl,
102 .fo_stat = mq_stat_fop,
103 .fo_close = mq_close_fop,
104 .fo_kqfilter = mq_kqfilter_fop,
105 .fo_shutdown = badfo_shutdown
108 /* Define a new malloc type for message queues */
109 MALLOC_DECLARE(M_MQBUF);
110 MALLOC_DEFINE(M_MQBUF, "mqueues", "Buffers to message queues");
113 * Initialize POSIX message queue subsystem.
118 lockinit(&mqlist_mtx, "mqlist_mtx", 0, LK_CANRECURSE);
125 mqueue_freemsg(struct mq_msg *msg, const size_t size)
131 * Destroy the message queue.
134 mqueue_destroy(struct mqueue *mq)
140 /* Note MQ_PQSIZE + 1. */
141 for (i = 0; i < MQ_PQSIZE + 1; i++) {
142 while ((msg = TAILQ_FIRST(&mq->mq_head[i])) != NULL) {
143 TAILQ_REMOVE(&mq->mq_head[i], msg, msg_queue);
144 msz = sizeof(struct mq_msg) + msg->msg_len;
145 mqueue_freemsg(msg, msz);
148 lockuninit(&mq->mq_mtx);
153 * Lookup for file name in general list of message queues.
154 * => locks the message queue
157 mqueue_lookup(char *name)
161 KKASSERT(lockstatus(&mqlist_mtx, curthread));
163 LIST_FOREACH(mq, &mqueue_head, mq_list) {
164 if (strncmp(mq->mq_name, name, MQ_NAMELEN) == 0) {
165 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
174 * mqueue_get: get the mqueue from the descriptor.
175 * => locks the message queue, if found.
176 * => holds a reference on the file descriptor.
179 mqueue_get(struct lwp *l, mqd_t mqd, file_t **fpr)
184 fp = holdfp(curproc->p_fd, (int)mqd, -1); /* XXX: Why -1 ? */
185 if (__predict_false(fp == NULL))
188 if (__predict_false(fp->f_type != DTYPE_MQUEUE)) {
193 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
200 * mqueue_linear_insert: perform linear insert according to the message
201 * priority into the reserved queue (MQ_PQRESQ). Reserved queue is a
202 * sorted list used only when mq_prio_max is increased via sysctl.
205 mqueue_linear_insert(struct mqueue *mq, struct mq_msg *msg)
209 TAILQ_FOREACH(mit, &mq->mq_head[MQ_PQRESQ], msg_queue) {
210 if (msg->msg_prio > mit->msg_prio)
214 TAILQ_INSERT_TAIL(&mq->mq_head[MQ_PQRESQ], msg, msg_queue);
216 TAILQ_INSERT_BEFORE(mit, msg, msg_queue);
221 * Compute number of ticks in the specified amount of time.
224 tstohz(const struct timespec *ts)
229 * usec has great enough resolution for hz, so convert to a
230 * timeval and use tvtohz() above.
232 TIMESPEC_TO_TIMEVAL(&tv, ts);
233 return tvtohz_high(&tv); /* XXX Why _high() and not _low() ? */
237 * Converter from struct timespec to the ticks.
238 * Used by mq_timedreceive(), mq_timedsend().
241 abstimeout2timo(struct timespec *ts, int *timo)
246 error = itimespecfix(ts);
251 timespecsub(ts, &tsd);
252 if (ts->tv_sec < 0 || (ts->tv_sec == 0 && ts->tv_nsec <= 0)) {
256 KKASSERT(*timo != 0);
262 mq_stat_fop(file_t *fp, struct stat *st, struct ucred *cred)
264 struct mqueue *mq = fp->f_data;
266 (void)memset(st, 0, sizeof(*st));
268 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
269 st->st_mode = mq->mq_mode;
270 st->st_uid = mq->mq_euid;
271 st->st_gid = mq->mq_egid;
272 st->st_atimespec = mq->mq_atime;
273 st->st_mtimespec = mq->mq_mtime;
274 /*st->st_ctimespec = st->st_birthtimespec = mq->mq_btime;*/
275 st->st_uid = fp->f_cred->cr_uid;
276 st->st_gid = fp->f_cred->cr_svgid;
277 lockmgr(&mq->mq_mtx, LK_RELEASE);
282 static struct filterops mqfiltops_read =
283 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, mqfilter_read_detach, mqfilter_read };
284 static struct filterops mqfiltops_write =
285 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, mqfilter_write_detach, mqfilter_write };
288 mq_kqfilter_fop(struct file *fp, struct knote *kn)
290 struct mqueue *mq = fp->f_data;
293 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
295 switch (kn->kn_filter) {
297 kn->kn_fop = &mqfiltops_read;
298 kn->kn_hook = (caddr_t)mq;
299 klist = &mq->mq_rkq.ki_note;
302 kn->kn_fop = &mqfiltops_write;
303 kn->kn_hook = (caddr_t)mq;
304 klist = &mq->mq_wkq.ki_note;
307 lockmgr(&mq->mq_mtx, LK_RELEASE);
311 knote_insert(klist, kn);
312 lockmgr(&mq->mq_mtx, LK_RELEASE);
318 mqfilter_read_detach(struct knote *kn)
320 struct mqueue *mq = (struct mqueue *)kn->kn_hook;
322 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
323 struct klist *klist = &mq->mq_rkq.ki_note;
324 knote_remove(klist, kn);
325 lockmgr(&mq->mq_mtx, LK_RELEASE);
329 mqfilter_write_detach(struct knote *kn)
331 struct mqueue *mq = (struct mqueue *)kn->kn_hook;
333 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
334 struct klist *klist = &mq->mq_wkq.ki_note;
335 knote_remove(klist, kn);
336 lockmgr(&mq->mq_mtx, LK_RELEASE);
340 mqfilter_read(struct knote *kn, long hint)
342 struct mqueue *mq = (struct mqueue *)kn->kn_hook;
343 struct mq_attr *mqattr;
346 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
347 mqattr = &mq->mq_attrib;
348 /* Ready for receiving, if there are messages in the queue */
349 if (mqattr->mq_curmsgs)
351 lockmgr(&mq->mq_mtx, LK_RELEASE);
357 mqfilter_write(struct knote *kn, long hint)
359 struct mqueue *mq = (struct mqueue *)kn->kn_hook;
360 struct mq_attr *mqattr;
363 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
364 mqattr = &mq->mq_attrib;
365 /* Ready for sending, if the message queue is not full */
366 if (mqattr->mq_curmsgs < mqattr->mq_maxmsg)
368 lockmgr(&mq->mq_mtx, LK_RELEASE);
374 mq_close_fop(file_t *fp)
376 struct proc *p = curproc;
377 struct mqueue *mq = fp->f_data;
380 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
381 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
383 /* Decrease the counters */
387 /* Remove notification if registered for this process */
388 if (mq->mq_notify_proc == p)
389 mq->mq_notify_proc = NULL;
392 * If this is the last reference and mqueue is marked for unlink,
393 * remove and later destroy the message queue.
395 if (mq->mq_refcnt == 0 && (mq->mq_attrib.mq_flags & MQ_UNLINK)) {
396 LIST_REMOVE(mq, mq_list);
401 lockmgr(&mq->mq_mtx, LK_RELEASE);
402 lockmgr(&mqlist_mtx, LK_RELEASE);
411 * General mqueue system calls.
415 sys_mq_open(struct mq_open_args *uap)
418 syscallarg(const char *) name;
419 syscallarg(int) oflag;
420 syscallarg(mode_t) mode;
421 syscallarg(struct mq_attr) attr;
423 struct thread *td = curthread;
424 struct proc *p = td->td_proc;
425 struct filedesc *fdp = p->p_fd;
426 struct mqueue *mq, *mq_new = NULL;
429 int mqd, error, oflag;
431 /* Check access mode flags */
432 oflag = SCARG(uap, oflag);
433 if ((oflag & O_ACCMODE) == (O_WRONLY | O_RDWR)) {
437 /* Get the name from the user-space */
438 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO | M_NULLOK);
441 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
443 kfree(name, M_MQBUF);
447 if (oflag & O_CREAT) {
451 /* Check the limit */
452 if (p->p_mqueue_cnt == mq_open_max) {
453 kfree(name, M_MQBUF);
457 /* Empty name is invalid */
458 if (name[0] == '\0') {
459 kfree(name, M_MQBUF);
463 /* Check for mqueue attributes */
464 if (SCARG(uap, attr)) {
465 error = copyin(SCARG(uap, attr), &attr,
466 sizeof(struct mq_attr));
468 kfree(name, M_MQBUF);
471 if (attr.mq_maxmsg <= 0 ||
472 attr.mq_maxmsg > mq_max_maxmsg ||
473 attr.mq_msgsize <= 0 ||
474 attr.mq_msgsize > mq_max_msgsize) {
475 kfree(name, M_MQBUF);
480 memset(&attr, 0, sizeof(struct mq_attr));
481 attr.mq_maxmsg = mq_def_maxmsg;
483 MQ_DEF_MSGSIZE - sizeof(struct mq_msg);
487 * Allocate new mqueue, initialize data structures,
488 * copy the name, attributes and set the flag.
490 mq_new = kmalloc(sizeof(struct mqueue), M_MQBUF,
491 M_WAITOK | M_ZERO | M_NULLOK);
492 if (mq_new == NULL) {
493 kfree(name, M_MQBUF);
497 lockinit(&mq_new->mq_mtx, "mq_new->mq_mtx", 0, LK_CANRECURSE);
498 for (i = 0; i < (MQ_PQSIZE + 1); i++) {
499 TAILQ_INIT(&mq_new->mq_head[i]);
502 strlcpy(mq_new->mq_name, name, MQ_NAMELEN);
503 memcpy(&mq_new->mq_attrib, &attr, sizeof(struct mq_attr));
505 /*CTASSERT((O_MASK & (MQ_UNLINK | MQ_RECEIVE)) == 0);*/
506 /* mq_new->mq_attrib.mq_flags = (O_MASK & oflag); */
507 mq_new->mq_attrib.mq_flags = oflag;
509 /* Store mode and effective UID with GID */
510 mq_new->mq_mode = ((SCARG(uap, mode) &
511 ~p->p_fd->fd_cmask) & ALLPERMS) & ~S_ISTXT;
512 mq_new->mq_euid = td->td_ucred->cr_uid;
513 mq_new->mq_egid = td->td_ucred->cr_svgid;
516 /* Allocate file structure and descriptor */
517 error = falloc(td->td_lwp, &fp, &mqd);
520 mqueue_destroy(mq_new);
521 kfree(name, M_MQBUF);
524 fp->f_type = DTYPE_MQUEUE;
525 fp->f_flag = FFLAGS(oflag) & (FREAD | FWRITE);
528 /* Look up for mqueue with such name */
529 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
530 mq = mqueue_lookup(name);
534 KKASSERT(lockstatus(&mq->mq_mtx, curthread));
536 /* Check if mqueue is not marked as unlinking */
537 if (mq->mq_attrib.mq_flags & MQ_UNLINK) {
541 /* Fail if O_EXCL is set, and mqueue already exists */
542 if ((oflag & O_CREAT) && (oflag & O_EXCL)) {
548 * Check the permissions. Note the difference between
549 * VREAD/VWRITE and FREAD/FWRITE.
552 if (fp->f_flag & FREAD) {
555 if (fp->f_flag & FWRITE) {
558 if (vaccess(VNON, mq->mq_mode, mq->mq_euid, mq->mq_egid,
559 acc_mode, td->td_ucred)) {
565 /* Fail if mqueue neither exists, nor we create it */
566 if ((oflag & O_CREAT) == 0) {
567 lockmgr(&mqlist_mtx, LK_RELEASE);
568 KKASSERT(mq_new == NULL);
569 fsetfd(fdp, NULL, mqd);
570 fp->f_ops = &badfileops;
572 kfree(name, M_MQBUF);
576 /* Check the limit */
577 if (p->p_mqueue_cnt == mq_open_max) {
582 /* Insert the queue to the list */
584 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
585 LIST_INSERT_HEAD(&mqueue_head, mq, mq_list);
587 getnanotime(&mq->mq_btime);
588 mq->mq_atime = mq->mq_mtime = mq->mq_btime;
591 /* Increase the counters, and make descriptor ready */
596 lockmgr(&mq->mq_mtx, LK_RELEASE);
597 lockmgr(&mqlist_mtx, LK_RELEASE);
600 mqueue_destroy(mq_new);
602 fsetfd(fdp, NULL, mqd);
603 fp->f_ops = &badfileops;
605 fsetfd(fdp, fp, mqd);
606 uap->sysmsg_result = mqd;
609 kfree(name, M_MQBUF);
615 sys_mq_close(struct mq_close_args *uap)
617 return sys_close((void *)uap);
621 * Primary mq_receive1() function.
624 mq_receive1(struct lwp *l, mqd_t mqdes, void *msg_ptr, size_t msg_len,
625 unsigned *msg_prio, struct timespec *ts, ssize_t *mlen)
629 struct mq_msg *msg = NULL;
630 struct mq_attr *mqattr;
634 /* Get the message queue */
635 error = mqueue_get(l, mqdes, &fp);
640 if ((fp->f_flag & FREAD) == 0) {
644 getnanotime(&mq->mq_atime);
645 mqattr = &mq->mq_attrib;
647 /* Check the message size limits */
648 if (msg_len < mqattr->mq_msgsize) {
653 /* Check if queue is empty */
654 while (mqattr->mq_curmsgs == 0) {
657 if (mqattr->mq_flags & O_NONBLOCK) {
662 error = abstimeout2timo(ts, &t);
668 * Block until someone sends the message.
669 * While doing this, notification should not be sent.
671 mqattr->mq_flags |= MQ_RECEIVE;
672 error = lksleep(&mq->mq_send_cv, &mq->mq_mtx, PCATCH, "mqsend", t);
673 mqattr->mq_flags &= ~MQ_RECEIVE;
674 if (error || (mqattr->mq_flags & MQ_UNLINK)) {
675 error = (error == EWOULDBLOCK) ? ETIMEDOUT : EINTR;
682 * Find the highest priority message, and remove it from the queue.
683 * At first, reserved queue is checked, bitmap is next.
685 msg = TAILQ_FIRST(&mq->mq_head[MQ_PQRESQ]);
686 if (__predict_true(msg == NULL)) {
687 idx = ffs(mq->mq_bitmap);
688 msg = TAILQ_FIRST(&mq->mq_head[idx]);
689 KKASSERT(msg != NULL);
693 TAILQ_REMOVE(&mq->mq_head[idx], msg, msg_queue);
695 /* Unmark the bit, if last message. */
696 if (__predict_true(idx) && TAILQ_EMPTY(&mq->mq_head[idx])) {
697 KKASSERT((MQ_PQSIZE - idx) == msg->msg_prio);
698 mq->mq_bitmap &= ~(1 << --idx);
701 /* Decrement the counter and signal waiter, if any */
702 mqattr->mq_curmsgs--;
703 wakeup_one(&mq->mq_recv_cv);
705 /* Ready for sending now */
706 KNOTE(&mq->mq_wkq.ki_note, 0);
708 lockmgr(&mq->mq_mtx, LK_RELEASE);
714 * Copy the data to the user-space.
715 * Note: According to POSIX, no message should be removed from the
716 * queue in case of fail - this would be violated.
718 *mlen = msg->msg_len;
719 error = copyout(msg->msg_ptr, msg_ptr, msg->msg_len);
720 if (error == 0 && msg_prio)
721 error = copyout(&msg->msg_prio, msg_prio, sizeof(unsigned));
722 mqueue_freemsg(msg, sizeof(struct mq_msg) + msg->msg_len);
728 sys_mq_receive(struct mq_receive_args *uap)
731 syscallarg(mqd_t) mqdes;
732 syscallarg(char *) msg_ptr;
733 syscallarg(size_t) msg_len;
734 syscallarg(unsigned *) msg_prio;
739 error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
740 SCARG(uap, msg_len), SCARG(uap, msg_prio), 0, &mlen);
742 uap->sysmsg_result = mlen;
748 sys_mq_timedreceive(struct mq_timedreceive_args *uap)
751 syscallarg(mqd_t) mqdes;
752 syscallarg(char *) msg_ptr;
753 syscallarg(size_t) msg_len;
754 syscallarg(unsigned *) msg_prio;
755 syscallarg(const struct timespec *) abs_timeout;
759 struct timespec ts, *tsp;
761 /* Get and convert time value */
762 if (SCARG(uap, abs_timeout)) {
763 error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts));
771 error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
772 SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp, &mlen);
774 uap->sysmsg_result = mlen;
780 * Primary mq_send1() function.
783 mq_send1(struct lwp *l, mqd_t mqdes, const char *msg_ptr, size_t msg_len,
784 unsigned msg_prio, struct timespec *ts)
789 struct mq_attr *mqattr;
790 struct proc *notify = NULL;
795 /* Check the priority range */
796 if (msg_prio >= mq_prio_max)
799 /* Allocate a new message */
800 size = sizeof(struct mq_msg) + msg_len;
801 if (size > mq_max_msgsize)
804 msg = kmalloc(size, M_MQBUF, M_WAITOK | M_NULLOK);
809 /* Get the data from user-space */
810 error = copyin(msg_ptr, msg->msg_ptr, msg_len);
812 mqueue_freemsg(msg, size);
815 msg->msg_len = msg_len;
816 msg->msg_prio = msg_prio;
819 error = mqueue_get(l, mqdes, &fp);
821 mqueue_freemsg(msg, size);
825 if ((fp->f_flag & FWRITE) == 0) {
829 getnanotime(&mq->mq_mtime);
830 mqattr = &mq->mq_attrib;
832 /* Check the message size limit */
833 if (msg_len <= 0 || msg_len > mqattr->mq_msgsize) {
838 /* Check if queue is full */
839 while (mqattr->mq_curmsgs >= mqattr->mq_maxmsg) {
842 if (mqattr->mq_flags & O_NONBLOCK) {
847 error = abstimeout2timo(ts, &t);
852 /* Block until queue becomes available */
853 error = lksleep(&mq->mq_recv_cv, &mq->mq_mtx, PCATCH, "mqrecv", t);
854 if (error || (mqattr->mq_flags & MQ_UNLINK)) {
855 error = (error == EWOULDBLOCK) ? ETIMEDOUT : error;
859 KKASSERT(mq->mq_attrib.mq_curmsgs < mq->mq_attrib.mq_maxmsg);
862 * Insert message into the queue, according to the priority.
863 * Note the difference between index and priority.
865 if (__predict_true(msg_prio < MQ_PQSIZE)) {
866 u_int idx = MQ_PQSIZE - msg_prio;
868 KKASSERT(idx != MQ_PQRESQ);
869 TAILQ_INSERT_TAIL(&mq->mq_head[idx], msg, msg_queue);
870 mq->mq_bitmap |= (1 << --idx);
872 mqueue_linear_insert(mq, msg);
875 /* Check for the notify */
876 if (mqattr->mq_curmsgs == 0 && mq->mq_notify_proc &&
877 (mqattr->mq_flags & MQ_RECEIVE) == 0 &&
878 mq->mq_sig_notify.sigev_notify == SIGEV_SIGNAL) {
879 /* Initialize the signal */
881 /*ksi.ksi_signo = mq->mq_sig_notify.sigev_signo;*/
882 /*ksi.ksi_code = SI_MESGQ;*/
883 /*ksi.ksi_value = mq->mq_sig_notify.sigev_value;*/
884 /* Unregister the process */
885 notify = mq->mq_notify_proc;
886 mq->mq_notify_proc = NULL;
889 /* Increment the counter and signal waiter, if any */
890 mqattr->mq_curmsgs++;
891 wakeup_one(&mq->mq_send_cv);
893 /* Ready for receiving now */
894 KNOTE(&mq->mq_rkq.ki_note, 0);
897 lockmgr(&mq->mq_mtx, LK_RELEASE);
899 mqueue_freemsg(msg, size);
902 lockmgr(&mq->mq_mtx, LK_RELEASE);
904 /* Send the notify, if needed */
905 /*kpsignal(notify, &ksi, NULL);*/
906 ksignal(notify, mq->mq_sig_notify.sigev_signo);
909 lockmgr(&mq->mq_mtx, LK_RELEASE);
916 sys_mq_send(struct mq_send_args *uap)
919 syscallarg(mqd_t) mqdes;
920 syscallarg(const char *) msg_ptr;
921 syscallarg(size_t) msg_len;
922 syscallarg(unsigned) msg_prio;
925 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
926 SCARG(uap, msg_len), SCARG(uap, msg_prio), 0);
930 sys_mq_timedsend(struct mq_timedsend_args *uap)
933 syscallarg(mqd_t) mqdes;
934 syscallarg(const char *) msg_ptr;
935 syscallarg(size_t) msg_len;
936 syscallarg(unsigned) msg_prio;
937 syscallarg(const struct timespec *) abs_timeout;
939 struct timespec ts, *tsp;
942 /* Get and convert time value */
943 if (SCARG(uap, abs_timeout)) {
944 error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts));
952 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
953 SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp);
957 sys_mq_notify(struct mq_notify_args *uap)
960 syscallarg(mqd_t) mqdes;
961 syscallarg(const struct sigevent *) notification;
968 if (SCARG(uap, notification)) {
969 /* Get the signal from user-space */
970 error = copyin(SCARG(uap, notification), &sig,
971 sizeof(struct sigevent));
974 if (sig.sigev_notify == SIGEV_SIGNAL &&
975 (sig.sigev_signo <= 0 || sig.sigev_signo >= NSIG))
979 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
984 if (SCARG(uap, notification)) {
985 /* Register notification: set the signal and target process */
986 if (mq->mq_notify_proc == NULL) {
987 memcpy(&mq->mq_sig_notify, &sig,
988 sizeof(struct sigevent));
989 mq->mq_notify_proc = curproc;
991 /* Fail if someone else already registered */
995 /* Unregister the notification */
996 mq->mq_notify_proc = NULL;
998 lockmgr(&mq->mq_mtx, LK_RELEASE);
1005 sys_mq_getattr(struct mq_getattr_args *uap)
1008 syscallarg(mqd_t) mqdes;
1009 syscallarg(struct mq_attr *) mqstat;
1013 struct mq_attr attr;
1016 /* Get the message queue */
1017 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
1021 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
1022 lockmgr(&mq->mq_mtx, LK_RELEASE);
1025 return copyout(&attr, SCARG(uap, mqstat), sizeof(struct mq_attr));
1029 sys_mq_setattr(struct mq_setattr_args *uap)
1032 syscallarg(mqd_t) mqdes;
1033 syscallarg(const struct mq_attr *) mqstat;
1034 syscallarg(struct mq_attr *) omqstat;
1038 struct mq_attr attr;
1039 int error, nonblock;
1041 error = copyin(SCARG(uap, mqstat), &attr, sizeof(struct mq_attr));
1044 nonblock = (attr.mq_flags & O_NONBLOCK);
1046 /* Get the message queue */
1047 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
1052 /* Copy the old attributes, if needed */
1053 if (SCARG(uap, omqstat)) {
1054 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
1057 /* Ignore everything, except O_NONBLOCK */
1059 mq->mq_attrib.mq_flags |= O_NONBLOCK;
1061 mq->mq_attrib.mq_flags &= ~O_NONBLOCK;
1063 lockmgr(&mq->mq_mtx, LK_RELEASE);
1067 * Copy the data to the user-space.
1068 * Note: According to POSIX, the new attributes should not be set in
1069 * case of fail - this would be violated.
1071 if (SCARG(uap, omqstat))
1072 error = copyout(&attr, SCARG(uap, omqstat),
1073 sizeof(struct mq_attr));
1079 sys_mq_unlink(struct mq_unlink_args *uap)
1082 syscallarg(const char *) name;
1084 struct thread *td = curthread;
1087 int error, refcnt = 0;
1089 /* Get the name from the user-space */
1090 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO | M_NULLOK);
1093 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
1095 kfree(name, M_MQBUF);
1099 /* Lookup for this file */
1100 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
1101 mq = mqueue_lookup(name);
1107 /* Check the permissions */
1108 if (td->td_ucred->cr_uid != mq->mq_euid &&
1109 priv_check(td, PRIV_ROOT) != 0) {
1110 lockmgr(&mq->mq_mtx, LK_RELEASE);
1115 /* Mark message queue as unlinking, before leaving the window */
1116 mq->mq_attrib.mq_flags |= MQ_UNLINK;
1118 /* Wake up all waiters, if there are such */
1119 wakeup(&mq->mq_send_cv);
1120 wakeup(&mq->mq_recv_cv);
1122 KNOTE(&mq->mq_rkq.ki_note, 0);
1123 KNOTE(&mq->mq_wkq.ki_note, 0);
1125 refcnt = mq->mq_refcnt;
1127 LIST_REMOVE(mq, mq_list);
1129 lockmgr(&mq->mq_mtx, LK_RELEASE);
1131 lockmgr(&mqlist_mtx, LK_RELEASE);
1134 * If there are no references - destroy the message
1135 * queue, otherwise, the last mq_close() will do that.
1137 if (error == 0 && refcnt == 0)
1140 kfree(name, M_MQBUF);
1147 SYSCTL_NODE(_kern, OID_AUTO, mqueue,
1148 CTLFLAG_RW, 0, "Message queue options");
1150 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_open_max,
1151 CTLFLAG_RW, &mq_open_max, 0,
1152 "Maximal number of message queue descriptors per process");
1154 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_prio_max,
1155 CTLFLAG_RW, &mq_prio_max, 0,
1156 "Maximal priority of the message");
1158 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_msgsize,
1159 CTLFLAG_RW, &mq_max_msgsize, 0,
1160 "Maximal allowed size of the message");
1162 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_def_maxmsg,
1163 CTLFLAG_RW, &mq_def_maxmsg, 0,
1164 "Default maximal message count");
1166 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_maxmsg,
1167 CTLFLAG_RW, &mq_max_maxmsg, 0,
1168 "Maximal allowed message count");
1170 SYSINIT(sys_mqueue_init, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, mqueue_sysinit, NULL);