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.
45 #include <sys/param.h>
46 #include <sys/types.h>
47 #include <sys/errno.h>
48 #include <sys/fcntl.h>
50 #include <sys/filedesc.h>
51 #include <sys/ucred.h>
53 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/mqueue.h>
56 #include <sys/objcache.h>
59 #include <sys/queue.h>
60 #include <sys/select.h>
61 #include <sys/serialize.h>
62 #include <sys/signal.h>
63 #include <sys/signalvar.h>
64 #include <sys/spinlock.h>
65 #include <sys/spinlock2.h>
67 #include <sys/sysctl.h>
68 #include <sys/sysproto.h>
69 #include <sys/systm.h>
71 #include <sys/unistd.h>
72 #include <sys/vnode.h>
74 /* System-wide limits. */
75 static u_int mq_open_max = MQ_OPEN_MAX;
76 static u_int mq_prio_max = MQ_PRIO_MAX;
77 static u_int mq_max_msgsize = 16 * MQ_DEF_MSGSIZE;
78 static u_int mq_def_maxmsg = 32;
79 static u_int mq_max_maxmsg = 16 * 32;
81 struct lock mqlist_mtx;
82 static struct objcache * mqmsg_cache;
83 static LIST_HEAD(, mqueue) mqueue_head =
84 LIST_HEAD_INITIALIZER(mqueue_head);
86 typedef struct file file_t; /* XXX: Should we put this in sys/types.h ? */
88 /* Function prototypes */
89 static int mq_poll_fop(file_t *, int, struct ucred *cred);
90 static int mq_stat_fop(file_t *, struct stat *, struct ucred *cred);
91 static int mq_close_fop(file_t *);
93 /* Some time-related utility functions */
94 static int itimespecfix(struct timespec *ts);
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_poll = mq_poll_fop,
103 .fo_stat = mq_stat_fop,
104 .fo_close = mq_close_fop,
105 .fo_kqfilter = badfo_kqfilter,
106 .fo_shutdown = badfo_shutdown
109 /* Define a new malloc type for message queues */
110 MALLOC_DECLARE(M_MQBUF);
111 MALLOC_DEFINE(M_MQBUF, "mqueues", "Buffers to message queues");
113 /* Malloc arguments for object cache */
114 struct objcache_malloc_args mqueue_malloc_args = {
115 sizeof(struct mqueue), M_MQBUF };
117 /* Spinlock around the process list */
118 extern struct spinlock allproc_spin;
121 * Initialize POSIX message queue subsystem.
126 mqmsg_cache = objcache_create("mqmsg_cache",
127 0, /* infinite depot's capacity */
128 0, /* default magazine's capacity */
129 NULL, /* constructor */
130 NULL, /* deconstructor */
132 objcache_malloc_alloc,
133 objcache_malloc_free,
134 &mqueue_malloc_args);
136 lockinit(&mqlist_mtx, "mqlist_mtx", 0, LK_CANRECURSE);
143 mqueue_freemsg(struct mq_msg *msg, const size_t size)
146 if (size > MQ_DEF_MSGSIZE) {
149 objcache_put(mqmsg_cache, msg);
154 * Destroy the message queue.
157 mqueue_destroy(struct mqueue *mq)
163 /* Note MQ_PQSIZE + 1. */
164 for (i = 0; i < MQ_PQSIZE + 1; i++) {
165 while ((msg = TAILQ_FIRST(&mq->mq_head[i])) != NULL) {
166 TAILQ_REMOVE(&mq->mq_head[i], msg, msg_queue);
167 msz = sizeof(struct mq_msg) + msg->msg_len;
168 mqueue_freemsg(msg, msz);
171 lockuninit(&mq->mq_mtx);
176 * Lookup for file name in general list of message queues.
177 * => locks the message queue
180 mqueue_lookup(char *name)
184 KKASSERT(lockstatus(&mqlist_mtx, curthread));
186 LIST_FOREACH(mq, &mqueue_head, mq_list) {
187 if (strncmp(mq->mq_name, name, MQ_NAMELEN) == 0) {
188 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
197 * mqueue_get: get the mqueue from the descriptor.
198 * => locks the message queue, if found.
199 * => holds a reference on the file descriptor.
202 mqueue_get(struct lwp *l, mqd_t mqd, file_t **fpr)
207 fp = holdfp(curproc->p_fd, (int)mqd, -1); /* XXX: Why -1 ? */
208 if (__predict_false(fp == NULL))
211 if (__predict_false(fp->f_type != DTYPE_MQUEUE)) {
216 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
223 * mqueue_linear_insert: perform linear insert according to the message
224 * priority into the reserved queue (MQ_PQRESQ). Reserved queue is a
225 * sorted list used only when mq_prio_max is increased via sysctl.
228 mqueue_linear_insert(struct mqueue *mq, struct mq_msg *msg)
232 TAILQ_FOREACH(mit, &mq->mq_head[MQ_PQRESQ], msg_queue) {
233 if (msg->msg_prio > mit->msg_prio)
237 TAILQ_INSERT_TAIL(&mq->mq_head[MQ_PQRESQ], msg, msg_queue);
239 TAILQ_INSERT_BEFORE(mit, msg, msg_queue);
247 itimespecfix(struct timespec *ts)
249 if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
251 if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < nstick)
252 ts->tv_nsec = nstick;
257 * Compute number of ticks in the specified amount of time.
260 tstohz(const struct timespec *ts)
265 * usec has great enough resolution for hz, so convert to a
266 * timeval and use tvtohz() above.
268 TIMESPEC_TO_TIMEVAL(&tv, ts);
269 return tvtohz_high(&tv); /* XXX Why _high() and not _low() ? */
273 * Converter from struct timespec to the ticks.
274 * Used by mq_timedreceive(), mq_timedsend().
277 abstimeout2timo(struct timespec *ts, int *timo)
282 error = itimespecfix(ts);
287 timespecsub(ts, &tsd);
288 if (ts->tv_sec < 0 || (ts->tv_sec == 0 && ts->tv_nsec <= 0)) {
292 KKASSERT(*timo != 0);
298 mq_stat_fop(file_t *fp, struct stat *st, struct ucred *cred)
300 struct mqueue *mq = fp->f_data;
302 (void)memset(st, 0, sizeof(*st));
304 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
305 st->st_mode = mq->mq_mode;
306 st->st_uid = mq->mq_euid;
307 st->st_gid = mq->mq_egid;
308 st->st_atimespec = mq->mq_atime;
309 st->st_mtimespec = mq->mq_mtime;
310 /*st->st_ctimespec = st->st_birthtimespec = mq->mq_btime;*/
311 st->st_uid = fp->f_cred->cr_uid;
312 st->st_gid = fp->f_cred->cr_svgid;
313 lockmgr(&mq->mq_mtx, LK_RELEASE);
319 mq_poll_fop(file_t *fp, int events, struct ucred *cred)
321 struct mqueue *mq = fp->f_data;
322 struct mq_attr *mqattr;
325 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
326 mqattr = &mq->mq_attrib;
327 if (events & (POLLIN | POLLRDNORM)) {
328 /* Ready for receiving, if there are messages in the queue */
329 if (mqattr->mq_curmsgs)
330 revents |= (POLLIN | POLLRDNORM);
332 selrecord(curthread, &mq->mq_rsel);
334 if (events & (POLLOUT | POLLWRNORM)) {
335 /* Ready for sending, if the message queue is not full */
336 if (mqattr->mq_curmsgs < mqattr->mq_maxmsg)
337 revents |= (POLLOUT | POLLWRNORM);
339 selrecord(curthread, &mq->mq_wsel);
341 lockmgr(&mq->mq_mtx, LK_RELEASE);
347 mq_close_fop(file_t *fp)
349 struct proc *p = curproc;
350 struct mqueue *mq = fp->f_data;
353 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
354 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
356 /* Decrease the counters */
360 /* Remove notification if registered for this process */
361 if (mq->mq_notify_proc == p)
362 mq->mq_notify_proc = NULL;
365 * If this is the last reference and mqueue is marked for unlink,
366 * remove and later destroy the message queue.
368 if (mq->mq_refcnt == 0 && (mq->mq_attrib.mq_flags & MQ_UNLINK)) {
369 LIST_REMOVE(mq, mq_list);
374 lockmgr(&mq->mq_mtx, LK_RELEASE);
375 lockmgr(&mqlist_mtx, LK_RELEASE);
384 * General mqueue system calls.
388 sys_mq_open(struct mq_open_args *uap)
391 syscallarg(const char *) name;
392 syscallarg(int) oflag;
393 syscallarg(mode_t) mode;
394 syscallarg(struct mq_attr) attr;
396 struct thread *td = curthread;
397 struct proc *p = td->td_proc;
398 struct filedesc *fdp = p->p_fd;
399 struct mqueue *mq, *mq_new = NULL;
402 int mqd, error, oflag;
404 /* Check access mode flags */
405 oflag = SCARG(uap, oflag);
406 if ((oflag & O_ACCMODE) == (O_WRONLY | O_RDWR)) {
410 /* Get the name from the user-space */
411 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO);
412 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
414 kfree(name, M_MQBUF);
418 if (oflag & O_CREAT) {
422 /* Check the limit */
423 if (p->p_mqueue_cnt == mq_open_max) {
424 kfree(name, M_MQBUF);
428 /* Empty name is invalid */
429 if (name[0] == '\0') {
430 kfree(name, M_MQBUF);
434 /* Check for mqueue attributes */
435 if (SCARG(uap, attr)) {
436 error = copyin(SCARG(uap, attr), &attr,
437 sizeof(struct mq_attr));
439 kfree(name, M_MQBUF);
442 if (attr.mq_maxmsg <= 0 ||
443 attr.mq_maxmsg > mq_max_maxmsg ||
444 attr.mq_msgsize <= 0 ||
445 attr.mq_msgsize > mq_max_msgsize) {
446 kfree(name, M_MQBUF);
451 memset(&attr, 0, sizeof(struct mq_attr));
452 attr.mq_maxmsg = mq_def_maxmsg;
454 MQ_DEF_MSGSIZE - sizeof(struct mq_msg);
458 * Allocate new mqueue, initialize data structures,
459 * copy the name, attributes and set the flag.
461 mq_new = kmalloc(sizeof(struct mqueue), M_MQBUF, M_WAITOK | M_ZERO);
463 lockinit(&mq_new->mq_mtx, "mq_new->mq_mtx", 0, LK_CANRECURSE);
464 for (i = 0; i < (MQ_PQSIZE + 1); i++) {
465 TAILQ_INIT(&mq_new->mq_head[i]);
468 strlcpy(mq_new->mq_name, name, MQ_NAMELEN);
469 memcpy(&mq_new->mq_attrib, &attr, sizeof(struct mq_attr));
471 /*CTASSERT((O_MASK & (MQ_UNLINK | MQ_RECEIVE)) == 0);*/
472 /* mq_new->mq_attrib.mq_flags = (O_MASK & oflag); */
473 mq_new->mq_attrib.mq_flags = oflag;
475 /* Store mode and effective UID with GID */
476 mq_new->mq_mode = ((SCARG(uap, mode) &
477 ~p->p_fd->fd_cmask) & ALLPERMS) & ~S_ISTXT;
478 mq_new->mq_euid = td->td_ucred->cr_uid;
479 mq_new->mq_egid = td->td_ucred->cr_svgid;
482 /* Allocate file structure and descriptor */
483 error = falloc(td->td_lwp, &fp, &mqd);
486 mqueue_destroy(mq_new);
487 kfree(name, M_MQBUF);
490 fp->f_type = DTYPE_MQUEUE;
491 fp->f_flag = FFLAGS(oflag) & (FREAD | FWRITE);
494 /* Look up for mqueue with such name */
495 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
496 mq = mqueue_lookup(name);
500 KKASSERT(lockstatus(&mq->mq_mtx, curthread));
502 /* Check if mqueue is not marked as unlinking */
503 if (mq->mq_attrib.mq_flags & MQ_UNLINK) {
507 /* Fail if O_EXCL is set, and mqueue already exists */
508 if ((oflag & O_CREAT) && (oflag & O_EXCL)) {
514 * Check the permissions. Note the difference between
515 * VREAD/VWRITE and FREAD/FWRITE.
518 if (fp->f_flag & FREAD) {
521 if (fp->f_flag & FWRITE) {
524 if (vaccess(VNON, mq->mq_mode, mq->mq_euid, mq->mq_egid,
525 acc_mode, td->td_ucred)) {
531 /* Fail if mqueue neither exists, nor we create it */
532 if ((oflag & O_CREAT) == 0) {
533 lockmgr(&mqlist_mtx, LK_RELEASE);
534 KKASSERT(mq_new == NULL);
535 fsetfd(fdp, NULL, mqd);
536 fp->f_ops = &badfileops;
538 kfree(name, M_MQBUF);
542 /* Check the limit */
543 if (p->p_mqueue_cnt == mq_open_max) {
548 /* Insert the queue to the list */
550 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
551 LIST_INSERT_HEAD(&mqueue_head, mq, mq_list);
553 getnanotime(&mq->mq_btime);
554 mq->mq_atime = mq->mq_mtime = mq->mq_btime;
557 /* Increase the counters, and make descriptor ready */
562 lockmgr(&mq->mq_mtx, LK_RELEASE);
563 lockmgr(&mqlist_mtx, LK_RELEASE);
566 mqueue_destroy(mq_new);
568 fsetfd(fdp, NULL, mqd);
569 fp->f_ops = &badfileops;
571 fsetfd(fdp, fp, mqd);
572 uap->sysmsg_result = mqd;
575 kfree(name, M_MQBUF);
581 sys_mq_close(struct mq_close_args *uap)
583 return sys_close((void *)uap);
587 * Primary mq_receive1() function.
590 mq_receive1(struct lwp *l, mqd_t mqdes, void *msg_ptr, size_t msg_len,
591 unsigned *msg_prio, struct timespec *ts, ssize_t *mlen)
595 struct mq_msg *msg = NULL;
596 struct mq_attr *mqattr;
600 /* Get the message queue */
601 error = mqueue_get(l, mqdes, &fp);
606 if ((fp->f_flag & FREAD) == 0) {
610 getnanotime(&mq->mq_atime);
611 mqattr = &mq->mq_attrib;
613 /* Check the message size limits */
614 if (msg_len < mqattr->mq_msgsize) {
619 /* Check if queue is empty */
620 while (mqattr->mq_curmsgs == 0) {
623 if (mqattr->mq_flags & O_NONBLOCK) {
628 error = abstimeout2timo(ts, &t);
634 * Block until someone sends the message.
635 * While doing this, notification should not be sent.
637 mqattr->mq_flags |= MQ_RECEIVE;
638 error = lksleep(&mq->mq_send_cv, &mq->mq_mtx, PCATCH, "mqsend", t);
639 mqattr->mq_flags &= ~MQ_RECEIVE;
640 if (error || (mqattr->mq_flags & MQ_UNLINK)) {
641 error = (error == EWOULDBLOCK) ? ETIMEDOUT : EINTR;
648 * Find the highest priority message, and remove it from the queue.
649 * At first, reserved queue is checked, bitmap is next.
651 msg = TAILQ_FIRST(&mq->mq_head[MQ_PQRESQ]);
652 if (__predict_true(msg == NULL)) {
653 idx = ffs(mq->mq_bitmap);
654 msg = TAILQ_FIRST(&mq->mq_head[idx]);
655 KKASSERT(msg != NULL);
659 TAILQ_REMOVE(&mq->mq_head[idx], msg, msg_queue);
661 /* Unmark the bit, if last message. */
662 if (__predict_true(idx) && TAILQ_EMPTY(&mq->mq_head[idx])) {
663 KKASSERT((MQ_PQSIZE - idx) == msg->msg_prio);
664 mq->mq_bitmap &= ~(1 << --idx);
667 /* Decrement the counter and signal waiter, if any */
668 mqattr->mq_curmsgs--;
669 wakeup_one(&mq->mq_recv_cv);
671 /* Ready for sending now */
672 selwakeup(&mq->mq_wsel);
674 lockmgr(&mq->mq_mtx, LK_RELEASE);
680 * Copy the data to the user-space.
681 * Note: According to POSIX, no message should be removed from the
682 * queue in case of fail - this would be violated.
684 *mlen = msg->msg_len;
685 error = copyout(msg->msg_ptr, msg_ptr, msg->msg_len);
686 if (error == 0 && msg_prio)
687 error = copyout(&msg->msg_prio, msg_prio, sizeof(unsigned));
688 mqueue_freemsg(msg, sizeof(struct mq_msg) + msg->msg_len);
694 sys_mq_receive(struct mq_receive_args *uap)
697 syscallarg(mqd_t) mqdes;
698 syscallarg(char *) msg_ptr;
699 syscallarg(size_t) msg_len;
700 syscallarg(unsigned *) msg_prio;
705 error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
706 SCARG(uap, msg_len), SCARG(uap, msg_prio), 0, &mlen);
708 uap->sysmsg_result = mlen;
714 sys_mq_timedreceive(struct mq_timedreceive_args *uap)
717 syscallarg(mqd_t) mqdes;
718 syscallarg(char *) msg_ptr;
719 syscallarg(size_t) msg_len;
720 syscallarg(unsigned *) msg_prio;
721 syscallarg(const struct timespec *) abs_timeout;
725 struct timespec ts, *tsp;
727 /* Get and convert time value */
728 if (SCARG(uap, abs_timeout)) {
729 error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts));
737 error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
738 SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp, &mlen);
740 uap->sysmsg_result = mlen;
746 * Primary mq_send1() function.
749 mq_send1(struct lwp *l, mqd_t mqdes, const char *msg_ptr, size_t msg_len,
750 unsigned msg_prio, struct timespec *ts)
755 struct mq_attr *mqattr;
756 struct proc *notify = NULL;
761 /* Check the priority range */
762 if (msg_prio >= mq_prio_max)
765 /* Allocate a new message */
766 size = sizeof(struct mq_msg) + msg_len;
767 if (size > mq_max_msgsize)
770 if (size > MQ_DEF_MSGSIZE) {
771 msg = kmalloc(size, M_MQBUF, M_WAITOK);
773 msg = objcache_get(mqmsg_cache, M_WAITOK);
776 /* Get the data from user-space */
777 error = copyin(msg_ptr, msg->msg_ptr, msg_len);
779 mqueue_freemsg(msg, size);
782 msg->msg_len = msg_len;
783 msg->msg_prio = msg_prio;
786 error = mqueue_get(l, mqdes, &fp);
788 mqueue_freemsg(msg, size);
792 if ((fp->f_flag & FWRITE) == 0) {
796 getnanotime(&mq->mq_mtime);
797 mqattr = &mq->mq_attrib;
799 /* Check the message size limit */
800 if (msg_len <= 0 || msg_len > mqattr->mq_msgsize) {
805 /* Check if queue is full */
806 while (mqattr->mq_curmsgs >= mqattr->mq_maxmsg) {
809 if (mqattr->mq_flags & O_NONBLOCK) {
814 error = abstimeout2timo(ts, &t);
819 /* Block until queue becomes available */
820 error = lksleep(&mq->mq_recv_cv, &mq->mq_mtx, PCATCH, "mqrecv", t);
821 if (error || (mqattr->mq_flags & MQ_UNLINK)) {
822 error = (error == EWOULDBLOCK) ? ETIMEDOUT : error;
826 KKASSERT(mq->mq_attrib.mq_curmsgs < mq->mq_attrib.mq_maxmsg);
829 * Insert message into the queue, according to the priority.
830 * Note the difference between index and priority.
832 if (__predict_true(msg_prio < MQ_PQSIZE)) {
833 u_int idx = MQ_PQSIZE - msg_prio;
835 KKASSERT(idx != MQ_PQRESQ);
836 TAILQ_INSERT_TAIL(&mq->mq_head[idx], msg, msg_queue);
837 mq->mq_bitmap |= (1 << --idx);
839 mqueue_linear_insert(mq, msg);
842 /* Check for the notify */
843 if (mqattr->mq_curmsgs == 0 && mq->mq_notify_proc &&
844 (mqattr->mq_flags & MQ_RECEIVE) == 0 &&
845 mq->mq_sig_notify.sigev_notify == SIGEV_SIGNAL) {
846 /* Initialize the signal */
848 /*ksi.ksi_signo = mq->mq_sig_notify.sigev_signo;*/
849 /*ksi.ksi_code = SI_MESGQ;*/
850 /*ksi.ksi_value = mq->mq_sig_notify.sigev_value;*/
851 /* Unregister the process */
852 notify = mq->mq_notify_proc;
853 mq->mq_notify_proc = NULL;
856 /* Increment the counter and signal waiter, if any */
857 mqattr->mq_curmsgs++;
858 wakeup_one(&mq->mq_send_cv);
860 /* Ready for receiving now */
861 selwakeup(&mq->mq_rsel);
863 lockmgr(&mq->mq_mtx, LK_RELEASE);
867 mqueue_freemsg(msg, size);
869 /* Send the notify, if needed */
870 spin_lock_wr(&allproc_spin);
871 /*kpsignal(notify, &ksi, NULL);*/
872 ksignal(notify, mq->mq_sig_notify.sigev_signo);
873 spin_unlock_wr(&allproc_spin);
880 sys_mq_send(struct mq_send_args *uap)
883 syscallarg(mqd_t) mqdes;
884 syscallarg(const char *) msg_ptr;
885 syscallarg(size_t) msg_len;
886 syscallarg(unsigned) msg_prio;
889 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
890 SCARG(uap, msg_len), SCARG(uap, msg_prio), 0);
894 sys_mq_timedsend(struct mq_timedsend_args *uap)
897 syscallarg(mqd_t) mqdes;
898 syscallarg(const char *) msg_ptr;
899 syscallarg(size_t) msg_len;
900 syscallarg(unsigned) msg_prio;
901 syscallarg(const struct timespec *) abs_timeout;
903 struct timespec ts, *tsp;
906 /* Get and convert time value */
907 if (SCARG(uap, abs_timeout)) {
908 error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts));
916 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
917 SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp);
921 sys_mq_notify(struct mq_notify_args *uap)
924 syscallarg(mqd_t) mqdes;
925 syscallarg(const struct sigevent *) notification;
932 if (SCARG(uap, notification)) {
933 /* Get the signal from user-space */
934 error = copyin(SCARG(uap, notification), &sig,
935 sizeof(struct sigevent));
938 if (sig.sigev_notify == SIGEV_SIGNAL &&
939 (sig.sigev_signo <= 0 || sig.sigev_signo >= NSIG))
943 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
948 if (SCARG(uap, notification)) {
949 /* Register notification: set the signal and target process */
950 if (mq->mq_notify_proc == NULL) {
951 memcpy(&mq->mq_sig_notify, &sig,
952 sizeof(struct sigevent));
953 mq->mq_notify_proc = curproc;
955 /* Fail if someone else already registered */
959 /* Unregister the notification */
960 mq->mq_notify_proc = NULL;
962 lockmgr(&mq->mq_mtx, LK_RELEASE);
969 sys_mq_getattr(struct mq_getattr_args *uap)
972 syscallarg(mqd_t) mqdes;
973 syscallarg(struct mq_attr *) mqstat;
980 /* Get the message queue */
981 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
985 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
986 lockmgr(&mq->mq_mtx, LK_RELEASE);
989 return copyout(&attr, SCARG(uap, mqstat), sizeof(struct mq_attr));
993 sys_mq_setattr(struct mq_setattr_args *uap)
996 syscallarg(mqd_t) mqdes;
997 syscallarg(const struct mq_attr *) mqstat;
998 syscallarg(struct mq_attr *) omqstat;
1002 struct mq_attr attr;
1003 int error, nonblock;
1005 error = copyin(SCARG(uap, mqstat), &attr, sizeof(struct mq_attr));
1008 nonblock = (attr.mq_flags & O_NONBLOCK);
1010 /* Get the message queue */
1011 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
1016 /* Copy the old attributes, if needed */
1017 if (SCARG(uap, omqstat)) {
1018 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
1021 /* Ignore everything, except O_NONBLOCK */
1023 mq->mq_attrib.mq_flags |= O_NONBLOCK;
1025 mq->mq_attrib.mq_flags &= ~O_NONBLOCK;
1027 lockmgr(&mq->mq_mtx, LK_RELEASE);
1031 * Copy the data to the user-space.
1032 * Note: According to POSIX, the new attributes should not be set in
1033 * case of fail - this would be violated.
1035 if (SCARG(uap, omqstat))
1036 error = copyout(&attr, SCARG(uap, omqstat),
1037 sizeof(struct mq_attr));
1043 sys_mq_unlink(struct mq_unlink_args *uap)
1046 syscallarg(const char *) name;
1048 struct thread *td = curthread;
1051 int error, refcnt = 0;
1053 /* Get the name from the user-space */
1054 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO);
1055 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
1057 kfree(name, M_MQBUF);
1061 /* Lookup for this file */
1062 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
1063 mq = mqueue_lookup(name);
1069 /* Check the permissions */
1070 if (td->td_ucred->cr_uid != mq->mq_euid &&
1071 priv_check(td, PRIV_ROOT) != 0) {
1072 lockmgr(&mq->mq_mtx, LK_RELEASE);
1077 /* Mark message queue as unlinking, before leaving the window */
1078 mq->mq_attrib.mq_flags |= MQ_UNLINK;
1080 /* Wake up all waiters, if there are such */
1081 wakeup(&mq->mq_send_cv);
1082 wakeup(&mq->mq_recv_cv);
1084 selwakeup(&mq->mq_rsel);
1085 selwakeup(&mq->mq_wsel);
1087 refcnt = mq->mq_refcnt;
1089 LIST_REMOVE(mq, mq_list);
1091 lockmgr(&mq->mq_mtx, LK_RELEASE);
1093 lockmgr(&mqlist_mtx, LK_RELEASE);
1096 * If there are no references - destroy the message
1097 * queue, otherwise, the last mq_close() will do that.
1099 if (error == 0 && refcnt == 0)
1102 kfree(name, M_MQBUF);
1109 SYSCTL_NODE(_kern, OID_AUTO, mqueue,
1110 CTLFLAG_RW, 0, "Message queue options");
1112 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_open_max,
1113 CTLFLAG_RW, &mq_open_max, 0,
1114 "Maximal number of message queue descriptors per process");
1116 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_prio_max,
1117 CTLFLAG_RW, &mq_prio_max, 0,
1118 "Maximal priority of the message");
1120 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_msgsize,
1121 CTLFLAG_RW, &mq_max_msgsize, 0,
1122 "Maximal allowed size of the message");
1124 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_def_maxmsg,
1125 CTLFLAG_RW, &mq_def_maxmsg, 0,
1126 "Default maximal message count");
1128 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_maxmsg,
1129 CTLFLAG_RW, &mq_max_maxmsg, 0,
1130 "Maximal allowed message count");
1132 SYSINIT(sys_mqueue_init, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, mqueue_sysinit, NULL);