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;
80 struct lock mqlist_mtx;
81 static struct objcache * mqmsg_cache;
82 static LIST_HEAD(, mqueue) mqueue_head =
83 LIST_HEAD_INITIALIZER(mqueue_head);
85 typedef struct file file_t; /* XXX: Should we put this in sys/types.h ? */
87 /* Function prototypes */
88 static int mq_poll_fop(file_t *, int, struct ucred *cred);
89 static int mq_stat_fop(file_t *, struct stat *, struct ucred *cred);
90 static int mq_close_fop(file_t *);
92 /* Some time-related utility functions */
93 static int itimespecfix(struct timespec *ts);
94 static int tstohz(const struct timespec *ts);
96 /* File operations vector */
97 static struct fileops mqops = {
98 .fo_read = badfo_readwrite,
99 .fo_write = badfo_readwrite,
100 .fo_ioctl = badfo_ioctl,
101 .fo_poll = mq_poll_fop,
102 .fo_stat = mq_stat_fop,
103 .fo_close = mq_close_fop,
104 .fo_kqfilter = badfo_kqfilter,
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");
112 /* Malloc arguments for object cache */
113 struct objcache_malloc_args mqueue_malloc_args = {
114 sizeof(struct mqueue), M_MQBUF };
116 /* Spinlock around the process list */
117 extern struct spinlock allproc_spin;
120 * Initialize POSIX message queue subsystem.
125 mqmsg_cache = objcache_create("mqmsg_cache",
126 0, /* infinite depot's capacity */
127 0, /* default magazine's capacity */
128 NULL, /* constructor */
129 NULL, /* deconstructor */
131 objcache_malloc_alloc,
132 objcache_malloc_free,
133 &mqueue_malloc_args);
135 lockinit(&mqlist_mtx, "mqlist_mtx", 0, LK_CANRECURSE);
142 mqueue_freemsg(struct mq_msg *msg, const size_t size)
145 if (size > MQ_DEF_MSGSIZE)
148 objcache_put(mqmsg_cache, msg);
152 * Destroy the message queue.
155 mqueue_destroy(struct mqueue *mq)
161 /* Note MQ_PQSIZE + 1. */
162 for (i = 0; i < MQ_PQSIZE + 1; i++) {
163 while ((msg = TAILQ_FIRST(&mq->mq_head[i])) != NULL) {
164 TAILQ_REMOVE(&mq->mq_head[i], msg, msg_queue);
165 msz = sizeof(struct mq_msg) + msg->msg_len;
166 mqueue_freemsg(msg, msz);
169 lockuninit(&mq->mq_mtx);
174 * Lookup for file name in general list of message queues.
175 * => locks the message queue
178 mqueue_lookup(char *name)
182 KKASSERT(lockstatus(&mqlist_mtx, curthread));
184 LIST_FOREACH(mq, &mqueue_head, mq_list) {
185 if (strncmp(mq->mq_name, name, MQ_NAMELEN) == 0) {
186 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
195 * mqueue_get: get the mqueue from the descriptor.
196 * => locks the message queue, if found.
197 * => hold a reference on the file descriptor.
200 mqueue_get(struct lwp *l, mqd_t mqd, file_t **fpr)
205 fp = holdfp(curproc->p_fd, (int)mqd, -1); /* XXX: Why -1 ? */
206 if (__predict_false(fp == NULL))
209 if (__predict_false(fp->f_type != DTYPE_MQUEUE)) {
214 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
221 * mqueue_linear_insert: perform linear insert according to the message
222 * priority into the reserved queue (MQ_PQRESQ). Reserved queue is a
223 * sorted list used only when mq_prio_max is increased via sysctl.
226 mqueue_linear_insert(struct mqueue *mq, struct mq_msg *msg)
230 TAILQ_FOREACH(mit, &mq->mq_head[MQ_PQRESQ], msg_queue) {
231 if (msg->msg_prio > mit->msg_prio)
235 TAILQ_INSERT_TAIL(&mq->mq_head[MQ_PQRESQ], msg, msg_queue);
237 TAILQ_INSERT_BEFORE(mit, msg, msg_queue);
245 itimespecfix(struct timespec *ts)
247 if (ts->tv_sec < 0 || ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000)
249 if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < nstick)
250 ts->tv_nsec = nstick;
255 * Compute number of ticks in the specified amount of time.
258 tstohz(const struct timespec *ts)
263 * usec has great enough resolution for hz, so convert to a
264 * timeval and use tvtohz() above.
266 TIMESPEC_TO_TIMEVAL(&tv, ts);
267 return tvtohz_high(&tv); /* XXX Why _high() and not _low() ? */
271 * Converter from struct timespec to the ticks.
272 * Used by mq_timedreceive(), mq_timedsend().
275 abstimeout2timo(struct timespec *ts, int *timo)
280 error = itimespecfix(ts);
285 timespecsub(ts, &tsd);
286 if (ts->tv_sec < 0 || (ts->tv_sec == 0 && ts->tv_nsec <= 0)) {
290 KKASSERT(*timo != 0);
296 mq_stat_fop(file_t *fp, struct stat *st, struct ucred *cred)
298 struct mqueue *mq = fp->f_data;
300 (void)memset(st, 0, sizeof(*st));
302 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
303 st->st_mode = mq->mq_mode;
304 st->st_uid = mq->mq_euid;
305 st->st_gid = mq->mq_egid;
306 st->st_atimespec = mq->mq_atime;
307 st->st_mtimespec = mq->mq_mtime;
308 /*st->st_ctimespec = st->st_birthtimespec = mq->mq_btime;*/
309 st->st_uid = fp->f_cred->cr_uid;
310 st->st_gid = fp->f_cred->cr_svgid;
311 lockmgr(&mq->mq_mtx, LK_RELEASE);
317 mq_poll_fop(file_t *fp, int events, struct ucred *cred)
319 struct mqueue *mq = fp->f_data;
322 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
323 if (events & (POLLIN | POLLRDNORM)) {
324 /* Ready for receiving, if there are messages in the queue */
325 if (mq->mq_attrib.mq_curmsgs)
326 revents |= (POLLIN | POLLRDNORM);
328 selrecord(curthread, &mq->mq_rsel);
330 if (events & (POLLOUT | POLLWRNORM)) {
331 /* Ready for sending, if the message queue is not full */
332 if (mq->mq_attrib.mq_curmsgs < mq->mq_attrib.mq_maxmsg)
333 revents |= (POLLOUT | POLLWRNORM);
335 selrecord(curthread, &mq->mq_wsel);
337 lockmgr(&mq->mq_mtx, LK_RELEASE);
343 mq_close_fop(file_t *fp)
345 struct proc *p = curproc;
346 struct mqueue *mq = fp->f_data;
349 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
350 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
352 /* Decrease the counters */
356 /* Remove notification if registered for this process */
357 if (mq->mq_notify_proc == p)
358 mq->mq_notify_proc = NULL;
361 * If this is the last reference and mqueue is marked for unlink,
362 * remove and later destroy the message queue.
364 if (mq->mq_refcnt == 0 && (mq->mq_attrib.mq_flags & MQ_UNLINK)) {
365 LIST_REMOVE(mq, mq_list);
370 lockmgr(&mq->mq_mtx, LK_RELEASE);
371 lockmgr(&mqlist_mtx, LK_RELEASE);
380 * General mqueue system calls.
384 sys_mq_open(struct mq_open_args *uap)
387 syscallarg(const char *) name;
388 syscallarg(int) oflag;
389 syscallarg(mode_t) mode;
390 syscallarg(struct mq_attr) attr;
392 struct thread *td = curthread;
393 struct proc *p = td->td_proc;
394 struct filedesc *fdp = p->p_fd;
395 struct mqueue *mq, *mq_new = NULL;
398 int mqd, error, oflag;
400 /* Check access mode flags */
401 oflag = SCARG(uap, oflag);
402 if ((oflag & O_ACCMODE) == (O_WRONLY | O_RDWR)) {
406 /* Get the name from the user-space */
407 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO);
408 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
410 kfree(name, M_MQBUF);
414 if (oflag & O_CREAT) {
418 /* Check the limit */
419 if (p->p_mqueue_cnt == mq_open_max) {
420 kfree(name, M_MQBUF);
424 /* Empty name is invalid */
425 if (name[0] == '\0') {
426 kfree(name, M_MQBUF);
430 /* Check for mqueue attributes */
431 if (SCARG(uap, attr)) {
432 error = copyin(SCARG(uap, attr), &attr,
433 sizeof(struct mq_attr));
435 kfree(name, M_MQBUF);
438 if (attr.mq_maxmsg <= 0 || attr.mq_msgsize <= 0 ||
439 attr.mq_msgsize > mq_max_msgsize) {
440 kfree(name, M_MQBUF);
445 memset(&attr, 0, sizeof(struct mq_attr));
446 attr.mq_maxmsg = mq_def_maxmsg;
448 MQ_DEF_MSGSIZE - sizeof(struct mq_msg);
452 * Allocate new mqueue, initialize data structures,
453 * copy the name, attributes and set the flag.
455 mq_new = kmalloc(sizeof(struct mqueue), M_MQBUF, M_WAITOK | M_ZERO);
457 lockinit(&mq_new->mq_mtx, "mq_new->mq_mtx", 0, LK_CANRECURSE);
458 for (i = 0; i < (MQ_PQSIZE + 1); i++) {
459 TAILQ_INIT(&mq_new->mq_head[i]);
462 strlcpy(mq_new->mq_name, name, MQ_NAMELEN);
463 memcpy(&mq_new->mq_attrib, &attr, sizeof(struct mq_attr));
465 /*CTASSERT((O_MASK & (MQ_UNLINK | MQ_RECEIVE)) == 0);*/
466 /* mq_new->mq_attrib.mq_flags = (O_MASK & oflag); */
467 mq_new->mq_attrib.mq_flags = oflag;
469 /* Store mode and effective UID with GID */
470 mq_new->mq_mode = ((SCARG(uap, mode) &
471 ~p->p_fd->fd_cmask) & ALLPERMS) & ~S_ISTXT;
472 mq_new->mq_euid = td->td_ucred->cr_uid;
473 mq_new->mq_egid = td->td_ucred->cr_svgid;
476 /* Allocate file structure and descriptor */
477 error = falloc(td->td_lwp, &fp, &mqd);
480 mqueue_destroy(mq_new);
481 kfree(name, M_MQBUF);
484 fp->f_type = DTYPE_MQUEUE;
485 fp->f_flag = FFLAGS(oflag) & (FREAD | FWRITE);
488 /* Look up for mqueue with such name */
489 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
490 mq = mqueue_lookup(name);
494 KKASSERT(lockstatus(&mq->mq_mtx, curthread));
496 /* Check if mqueue is not marked as unlinking */
497 if (mq->mq_attrib.mq_flags & MQ_UNLINK) {
501 /* Fail if O_EXCL is set, and mqueue already exists */
502 if ((oflag & O_CREAT) && (oflag & O_EXCL)) {
508 * Check the permissions. Note the difference between
509 * VREAD/VWRITE and FREAD/FWRITE.
512 if (fp->f_flag & FREAD) {
515 if (fp->f_flag & FWRITE) {
518 if (vaccess(VNON, mq->mq_mode, mq->mq_euid, mq->mq_egid,
519 acc_mode, td->td_ucred)) {
525 /* Fail if mqueue neither exists, nor we create it */
526 if ((oflag & O_CREAT) == 0) {
527 lockmgr(&mqlist_mtx, LK_RELEASE);
528 KKASSERT(mq_new == NULL);
529 fsetfd(fdp, NULL, mqd);
530 fp->f_ops = &badfileops;
532 kfree(name, M_MQBUF);
536 /* Check the limit */
537 if (p->p_mqueue_cnt == mq_open_max) {
542 /* Insert the queue to the list */
544 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
545 LIST_INSERT_HEAD(&mqueue_head, mq, mq_list);
547 getnanotime(&mq->mq_btime);
548 mq->mq_atime = mq->mq_mtime = mq->mq_btime;
551 /* Increase the counters, and make descriptor ready */
556 lockmgr(&mq->mq_mtx, LK_RELEASE);
557 lockmgr(&mqlist_mtx, LK_RELEASE);
560 mqueue_destroy(mq_new);
562 fsetfd(fdp, NULL, mqd);
563 fp->f_ops = &badfileops;
565 fsetfd(fdp, fp, mqd);
566 uap->sysmsg_result = mqd;
569 kfree(name, M_MQBUF);
575 sys_mq_close(struct mq_close_args *uap)
577 return sys_close((void *)uap);
581 * Primary mq_receive1() function.
584 mq_receive1(struct lwp *l, mqd_t mqdes, void *msg_ptr, size_t msg_len,
585 unsigned *msg_prio, struct timespec *ts, ssize_t *mlen)
589 struct mq_msg *msg = NULL;
590 struct mq_attr *mqattr;
594 /* Get the message queue */
595 error = mqueue_get(l, mqdes, &fp);
600 if ((fp->f_flag & FREAD) == 0) {
604 getnanotime(&mq->mq_atime);
605 mqattr = &mq->mq_attrib;
607 /* Check the message size limits */
608 if (msg_len < mqattr->mq_msgsize) {
613 /* Check if queue is empty */
614 while (mqattr->mq_curmsgs == 0) {
617 if (mqattr->mq_flags & O_NONBLOCK) {
622 error = abstimeout2timo(ts, &t);
628 * Block until someone sends the message.
629 * While doing this, notification should not be sent.
631 mqattr->mq_flags |= MQ_RECEIVE;
632 error = tsleep(&mq->mq_send_cv, PCATCH, "mqsend", t);
633 mqattr->mq_flags &= ~MQ_RECEIVE;
634 if (error || (mqattr->mq_flags & MQ_UNLINK)) {
635 error = (error == EWOULDBLOCK) ? ETIMEDOUT : EINTR;
642 * Find the highest priority message, and remove it from the queue.
643 * At first, reserved queue is checked, bitmap is next.
645 msg = TAILQ_FIRST(&mq->mq_head[MQ_PQRESQ]);
646 if (__predict_true(msg == NULL)) {
647 idx = ffs(mq->mq_bitmap);
648 msg = TAILQ_FIRST(&mq->mq_head[idx]);
649 KKASSERT(msg != NULL);
653 TAILQ_REMOVE(&mq->mq_head[idx], msg, msg_queue);
655 /* Unmark the bit, if last message. */
656 if (__predict_true(idx) && TAILQ_EMPTY(&mq->mq_head[idx])) {
657 KKASSERT((MQ_PQSIZE - idx) == msg->msg_prio);
658 mq->mq_bitmap &= ~(1 << --idx);
661 /* Decrement the counter and signal waiter, if any */
662 mqattr->mq_curmsgs--;
663 wakeup_one(&mq->mq_recv_cv);
665 /* Ready for sending now */
666 selwakeup(&mq->mq_wsel);
668 lockmgr(&mq->mq_mtx, LK_RELEASE);
674 * Copy the data to the user-space.
675 * Note: According to POSIX, no message should be removed from the
676 * queue in case of fail - this would be violated.
678 *mlen = msg->msg_len;
679 error = copyout(msg->msg_ptr, msg_ptr, msg->msg_len);
680 if (error == 0 && msg_prio)
681 error = copyout(&msg->msg_prio, msg_prio, sizeof(unsigned));
682 mqueue_freemsg(msg, sizeof(struct mq_msg) + msg->msg_len);
688 sys_mq_receive(struct mq_receive_args *uap)
691 syscallarg(mqd_t) mqdes;
692 syscallarg(char *) msg_ptr;
693 syscallarg(size_t) msg_len;
694 syscallarg(unsigned *) msg_prio;
699 error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
700 SCARG(uap, msg_len), SCARG(uap, msg_prio), 0, &mlen);
702 uap->sysmsg_result = mlen;
708 sys_mq_timedreceive(struct mq_timedreceive_args *uap)
711 syscallarg(mqd_t) mqdes;
712 syscallarg(char *) msg_ptr;
713 syscallarg(size_t) msg_len;
714 syscallarg(unsigned *) msg_prio;
715 syscallarg(const struct timespec *) abs_timeout;
719 struct timespec ts, *tsp;
721 /* Get and convert time value */
722 if (SCARG(uap, abs_timeout)) {
723 error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts));
731 error = mq_receive1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
732 SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp, &mlen);
734 uap->sysmsg_result = mlen;
740 * Primary mq_send1() function.
743 mq_send1(struct lwp *l, mqd_t mqdes, const char *msg_ptr, size_t msg_len,
744 unsigned msg_prio, struct timespec *ts)
749 struct mq_attr *mqattr;
750 struct proc *notify = NULL;
755 /* Check the priority range */
756 if (msg_prio >= mq_prio_max)
759 /* Allocate a new message */
760 size = sizeof(struct mq_msg) + msg_len;
761 if (size > mq_max_msgsize)
764 if (size > MQ_DEF_MSGSIZE) {
765 msg = kmalloc(size, M_MQBUF, M_WAITOK);
767 msg = objcache_get(mqmsg_cache, M_WAITOK);
770 /* Get the data from user-space */
771 error = copyin(msg_ptr, msg->msg_ptr, msg_len);
773 mqueue_freemsg(msg, size);
776 msg->msg_len = msg_len;
777 msg->msg_prio = msg_prio;
780 error = mqueue_get(l, mqdes, &fp);
782 mqueue_freemsg(msg, size);
786 if ((fp->f_flag & FWRITE) == 0) {
790 getnanotime(&mq->mq_mtime);
791 mqattr = &mq->mq_attrib;
793 /* Check the message size limit */
794 if (msg_len <= 0 || msg_len > mqattr->mq_msgsize) {
799 /* Check if queue is full */
800 while (mqattr->mq_curmsgs >= mqattr->mq_maxmsg) {
803 if (mqattr->mq_flags & O_NONBLOCK) {
808 error = abstimeout2timo(ts, &t);
813 /* Block until queue becomes available */
814 error = tsleep(&mq->mq_recv_cv, PCATCH, "mqrecv", t);
815 if (error || (mqattr->mq_flags & MQ_UNLINK)) {
816 error = (error == EWOULDBLOCK) ? ETIMEDOUT : error;
820 KKASSERT(mq->mq_attrib.mq_curmsgs < mq->mq_attrib.mq_maxmsg);
823 * Insert message into the queue, according to the priority.
824 * Note the difference between index and priority.
826 if (__predict_true(msg_prio < MQ_PQSIZE)) {
827 u_int idx = MQ_PQSIZE - msg_prio;
829 KKASSERT(idx != MQ_PQRESQ);
830 TAILQ_INSERT_TAIL(&mq->mq_head[idx], msg, msg_queue);
831 mq->mq_bitmap |= (1 << --idx);
833 mqueue_linear_insert(mq, msg);
836 /* Check for the notify */
837 if (mqattr->mq_curmsgs == 0 && mq->mq_notify_proc &&
838 (mqattr->mq_flags & MQ_RECEIVE) == 0 &&
839 mq->mq_sig_notify.sigev_notify == SIGEV_SIGNAL) {
840 /* Initialize the signal */
842 /*ksi.ksi_signo = mq->mq_sig_notify.sigev_signo;*/
843 /*ksi.ksi_code = SI_MESGQ;*/
844 /*ksi.ksi_value = mq->mq_sig_notify.sigev_value;*/
845 /* Unregister the process */
846 notify = mq->mq_notify_proc;
847 mq->mq_notify_proc = NULL;
850 /* Increment the counter and signal waiter, if any */
851 mqattr->mq_curmsgs++;
852 wakeup_one(&mq->mq_send_cv);
854 /* Ready for receiving now */
855 selwakeup(&mq->mq_rsel);
857 lockmgr(&mq->mq_mtx, LK_RELEASE);
861 mqueue_freemsg(msg, size);
863 /* Send the notify, if needed */
864 spin_lock_wr(&allproc_spin);
865 /*kpsignal(notify, &ksi, NULL);*/
866 ksignal(notify, mq->mq_sig_notify.sigev_signo);
867 spin_unlock_wr(&allproc_spin);
874 sys_mq_send(struct mq_send_args *uap)
877 syscallarg(mqd_t) mqdes;
878 syscallarg(const char *) msg_ptr;
879 syscallarg(size_t) msg_len;
880 syscallarg(unsigned) msg_prio;
883 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
884 SCARG(uap, msg_len), SCARG(uap, msg_prio), 0);
888 sys_mq_timedsend(struct mq_timedsend_args *uap)
891 syscallarg(mqd_t) mqdes;
892 syscallarg(const char *) msg_ptr;
893 syscallarg(size_t) msg_len;
894 syscallarg(unsigned) msg_prio;
895 syscallarg(const struct timespec *) abs_timeout;
897 struct timespec ts, *tsp;
900 /* Get and convert time value */
901 if (SCARG(uap, abs_timeout)) {
902 error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts));
910 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
911 SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp);
915 sys_mq_notify(struct mq_notify_args *uap)
918 syscallarg(mqd_t) mqdes;
919 syscallarg(const struct sigevent *) notification;
926 if (SCARG(uap, notification)) {
927 /* Get the signal from user-space */
928 error = copyin(SCARG(uap, notification), &sig,
929 sizeof(struct sigevent));
932 if (sig.sigev_notify == SIGEV_SIGNAL &&
933 (sig.sigev_signo <= 0 || sig.sigev_signo >= NSIG))
937 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
942 if (SCARG(uap, notification)) {
943 /* Register notification: set the signal and target process */
944 if (mq->mq_notify_proc == NULL) {
945 memcpy(&mq->mq_sig_notify, &sig,
946 sizeof(struct sigevent));
947 mq->mq_notify_proc = curproc;
949 /* Fail if someone else already registered */
953 /* Unregister the notification */
954 mq->mq_notify_proc = NULL;
956 lockmgr(&mq->mq_mtx, LK_RELEASE);
963 sys_mq_getattr(struct mq_getattr_args *uap)
966 syscallarg(mqd_t) mqdes;
967 syscallarg(struct mq_attr *) mqstat;
974 /* Get the message queue */
975 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
979 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
980 lockmgr(&mq->mq_mtx, LK_RELEASE);
983 return copyout(&attr, SCARG(uap, mqstat), sizeof(struct mq_attr));
987 sys_mq_setattr(struct mq_setattr_args *uap)
990 syscallarg(mqd_t) mqdes;
991 syscallarg(const struct mq_attr *) mqstat;
992 syscallarg(struct mq_attr *) omqstat;
999 error = copyin(SCARG(uap, mqstat), &attr, sizeof(struct mq_attr));
1002 nonblock = (attr.mq_flags & O_NONBLOCK);
1004 /* Get the message queue */
1005 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
1010 /* Copy the old attributes, if needed */
1011 if (SCARG(uap, omqstat))
1012 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
1014 /* Ignore everything, except O_NONBLOCK */
1016 mq->mq_attrib.mq_flags |= O_NONBLOCK;
1018 mq->mq_attrib.mq_flags &= ~O_NONBLOCK;
1020 lockmgr(&mq->mq_mtx, LK_RELEASE);
1024 * Copy the data to the user-space.
1025 * Note: According to POSIX, the new attributes should not be set in
1026 * case of fail - this would be violated.
1028 if (SCARG(uap, omqstat))
1029 error = copyout(&attr, SCARG(uap, omqstat),
1030 sizeof(struct mq_attr));
1036 sys_mq_unlink(struct mq_unlink_args *uap)
1039 syscallarg(const char *) name;
1041 struct thread *td = curthread;
1044 int error, refcnt = 0;
1046 /* Get the name from the user-space */
1047 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO);
1048 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
1050 kfree(name, M_MQBUF);
1054 /* Lookup for this file */
1055 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
1056 mq = mqueue_lookup(name);
1062 /* Check the permissions */
1063 if (td->td_ucred->cr_uid != mq->mq_euid &&
1064 priv_check(td, PRIV_ROOT) != 0) {
1065 lockmgr(&mq->mq_mtx, LK_RELEASE);
1070 /* Mark message queue as unlinking, before leaving the window */
1071 mq->mq_attrib.mq_flags |= MQ_UNLINK;
1073 /* Wake up all waiters, if there are such */
1074 wakeup(&mq->mq_send_cv);
1075 wakeup(&mq->mq_recv_cv);
1077 selwakeup(&mq->mq_rsel);
1078 selwakeup(&mq->mq_wsel);
1080 refcnt = mq->mq_refcnt;
1082 LIST_REMOVE(mq, mq_list);
1084 lockmgr(&mq->mq_mtx, LK_RELEASE);
1086 lockmgr(&mqlist_mtx, LK_RELEASE);
1089 * If there are no references - destroy the message
1090 * queue, otherwise, the last mq_close() will do that.
1092 if (error == 0 && refcnt == 0)
1095 kfree(name, M_MQBUF);
1102 SYSCTL_NODE(_kern, OID_AUTO, mqueue,
1103 CTLFLAG_RW, 0, "Message queue options");
1105 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_open_max,
1106 CTLFLAG_RW, &mq_open_max, 0,
1107 "Maximal number of message queue descriptors per process");
1109 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_prio_max,
1110 CTLFLAG_RW, &mq_prio_max, 0,
1111 "Maximal priority of the message");
1113 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_msgsize,
1114 CTLFLAG_RW, &mq_max_msgsize, 0,
1115 "Maximal allowed size of the message");
1117 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_def_maxmsg,
1118 CTLFLAG_RW, &mq_def_maxmsg, 0,
1119 "Default maximal message count");
1121 SYSINIT(sys_mqueue_init, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, mqueue_sysinit, NULL);