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/mplock2.h>
56 #include <sys/mqueue.h>
57 #include <sys/objcache.h>
60 #include <sys/queue.h>
61 #include <sys/select.h>
62 #include <sys/serialize.h>
63 #include <sys/signal.h>
64 #include <sys/signalvar.h>
65 #include <sys/spinlock.h>
66 #include <sys/spinlock2.h>
68 #include <sys/sysctl.h>
69 #include <sys/sysproto.h>
70 #include <sys/systm.h>
72 #include <sys/unistd.h>
73 #include <sys/vnode.h>
75 /* System-wide limits. */
76 static u_int mq_open_max = MQ_OPEN_MAX;
77 static u_int mq_prio_max = MQ_PRIO_MAX;
78 static u_int mq_max_msgsize = 16 * MQ_DEF_MSGSIZE;
79 static u_int mq_def_maxmsg = 32;
80 static u_int mq_max_maxmsg = 16 * 32;
82 struct lock mqlist_mtx;
83 static struct objcache * mqmsg_cache;
84 static LIST_HEAD(, mqueue) mqueue_head =
85 LIST_HEAD_INITIALIZER(mqueue_head);
87 typedef struct file file_t; /* XXX: Should we put this in sys/types.h ? */
89 /* Function prototypes */
90 static int mq_poll_fop(file_t *, int, struct ucred *cred);
91 static int mq_stat_fop(file_t *, struct stat *, struct ucred *cred);
92 static int mq_close_fop(file_t *);
94 /* Some time-related utility functions */
95 static int itimespecfix(struct timespec *ts);
96 static int tstohz(const struct timespec *ts);
98 /* File operations vector */
99 static struct fileops mqops = {
100 .fo_read = badfo_readwrite,
101 .fo_write = badfo_readwrite,
102 .fo_ioctl = badfo_ioctl,
103 .fo_poll = mq_poll_fop,
104 .fo_stat = mq_stat_fop,
105 .fo_close = mq_close_fop,
106 .fo_kqfilter = badfo_kqfilter,
107 .fo_shutdown = badfo_shutdown
110 /* Define a new malloc type for message queues */
111 MALLOC_DECLARE(M_MQBUF);
112 MALLOC_DEFINE(M_MQBUF, "mqueues", "Buffers to message queues");
114 /* Malloc arguments for object cache */
115 struct objcache_malloc_args mqueue_malloc_args = {
116 sizeof(struct mqueue), M_MQBUF };
119 * Initialize POSIX message queue subsystem.
124 mqmsg_cache = objcache_create("mqmsg_cache",
125 0, /* infinite depot's capacity */
126 0, /* default magazine's capacity */
127 NULL, /* constructor */
128 NULL, /* deconstructor */
130 objcache_malloc_alloc,
131 objcache_malloc_free,
132 &mqueue_malloc_args);
134 lockinit(&mqlist_mtx, "mqlist_mtx", 0, LK_CANRECURSE);
141 mqueue_freemsg(struct mq_msg *msg, const size_t size)
144 if (size > MQ_DEF_MSGSIZE) {
147 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 * => holds 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;
320 struct mq_attr *mqattr;
323 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
324 mqattr = &mq->mq_attrib;
325 if (events & (POLLIN | POLLRDNORM)) {
326 /* Ready for receiving, if there are messages in the queue */
327 if (mqattr->mq_curmsgs)
328 revents |= (POLLIN | POLLRDNORM);
330 selrecord(curthread, &mq->mq_rsel);
332 if (events & (POLLOUT | POLLWRNORM)) {
333 /* Ready for sending, if the message queue is not full */
334 if (mqattr->mq_curmsgs < mqattr->mq_maxmsg)
335 revents |= (POLLOUT | POLLWRNORM);
337 selrecord(curthread, &mq->mq_wsel);
339 lockmgr(&mq->mq_mtx, LK_RELEASE);
345 mq_close_fop(file_t *fp)
347 struct proc *p = curproc;
348 struct mqueue *mq = fp->f_data;
351 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
352 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
354 /* Decrease the counters */
358 /* Remove notification if registered for this process */
359 if (mq->mq_notify_proc == p)
360 mq->mq_notify_proc = NULL;
363 * If this is the last reference and mqueue is marked for unlink,
364 * remove and later destroy the message queue.
366 if (mq->mq_refcnt == 0 && (mq->mq_attrib.mq_flags & MQ_UNLINK)) {
367 LIST_REMOVE(mq, mq_list);
372 lockmgr(&mq->mq_mtx, LK_RELEASE);
373 lockmgr(&mqlist_mtx, LK_RELEASE);
382 * General mqueue system calls.
386 sys_mq_open(struct mq_open_args *uap)
389 syscallarg(const char *) name;
390 syscallarg(int) oflag;
391 syscallarg(mode_t) mode;
392 syscallarg(struct mq_attr) attr;
394 struct thread *td = curthread;
395 struct proc *p = td->td_proc;
396 struct filedesc *fdp = p->p_fd;
397 struct mqueue *mq, *mq_new = NULL;
400 int mqd, error, oflag;
402 /* Check access mode flags */
403 oflag = SCARG(uap, oflag);
404 if ((oflag & O_ACCMODE) == (O_WRONLY | O_RDWR)) {
408 /* Get the name from the user-space */
409 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO);
410 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
412 kfree(name, M_MQBUF);
416 if (oflag & O_CREAT) {
420 /* Check the limit */
421 if (p->p_mqueue_cnt == mq_open_max) {
422 kfree(name, M_MQBUF);
426 /* Empty name is invalid */
427 if (name[0] == '\0') {
428 kfree(name, M_MQBUF);
432 /* Check for mqueue attributes */
433 if (SCARG(uap, attr)) {
434 error = copyin(SCARG(uap, attr), &attr,
435 sizeof(struct mq_attr));
437 kfree(name, M_MQBUF);
440 if (attr.mq_maxmsg <= 0 ||
441 attr.mq_maxmsg > mq_max_maxmsg ||
442 attr.mq_msgsize <= 0 ||
443 attr.mq_msgsize > mq_max_msgsize) {
444 kfree(name, M_MQBUF);
449 memset(&attr, 0, sizeof(struct mq_attr));
450 attr.mq_maxmsg = mq_def_maxmsg;
452 MQ_DEF_MSGSIZE - sizeof(struct mq_msg);
456 * Allocate new mqueue, initialize data structures,
457 * copy the name, attributes and set the flag.
459 mq_new = kmalloc(sizeof(struct mqueue), M_MQBUF, M_WAITOK | M_ZERO);
461 lockinit(&mq_new->mq_mtx, "mq_new->mq_mtx", 0, LK_CANRECURSE);
462 for (i = 0; i < (MQ_PQSIZE + 1); i++) {
463 TAILQ_INIT(&mq_new->mq_head[i]);
466 strlcpy(mq_new->mq_name, name, MQ_NAMELEN);
467 memcpy(&mq_new->mq_attrib, &attr, sizeof(struct mq_attr));
469 /*CTASSERT((O_MASK & (MQ_UNLINK | MQ_RECEIVE)) == 0);*/
470 /* mq_new->mq_attrib.mq_flags = (O_MASK & oflag); */
471 mq_new->mq_attrib.mq_flags = oflag;
473 /* Store mode and effective UID with GID */
474 mq_new->mq_mode = ((SCARG(uap, mode) &
475 ~p->p_fd->fd_cmask) & ALLPERMS) & ~S_ISTXT;
476 mq_new->mq_euid = td->td_ucred->cr_uid;
477 mq_new->mq_egid = td->td_ucred->cr_svgid;
480 /* Allocate file structure and descriptor */
481 error = falloc(td->td_lwp, &fp, &mqd);
484 mqueue_destroy(mq_new);
485 kfree(name, M_MQBUF);
488 fp->f_type = DTYPE_MQUEUE;
489 fp->f_flag = FFLAGS(oflag) & (FREAD | FWRITE);
492 /* Look up for mqueue with such name */
493 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
494 mq = mqueue_lookup(name);
498 KKASSERT(lockstatus(&mq->mq_mtx, curthread));
500 /* Check if mqueue is not marked as unlinking */
501 if (mq->mq_attrib.mq_flags & MQ_UNLINK) {
505 /* Fail if O_EXCL is set, and mqueue already exists */
506 if ((oflag & O_CREAT) && (oflag & O_EXCL)) {
512 * Check the permissions. Note the difference between
513 * VREAD/VWRITE and FREAD/FWRITE.
516 if (fp->f_flag & FREAD) {
519 if (fp->f_flag & FWRITE) {
522 if (vaccess(VNON, mq->mq_mode, mq->mq_euid, mq->mq_egid,
523 acc_mode, td->td_ucred)) {
529 /* Fail if mqueue neither exists, nor we create it */
530 if ((oflag & O_CREAT) == 0) {
531 lockmgr(&mqlist_mtx, LK_RELEASE);
532 KKASSERT(mq_new == NULL);
533 fsetfd(fdp, NULL, mqd);
534 fp->f_ops = &badfileops;
536 kfree(name, M_MQBUF);
540 /* Check the limit */
541 if (p->p_mqueue_cnt == mq_open_max) {
546 /* Insert the queue to the list */
548 lockmgr(&mq->mq_mtx, LK_EXCLUSIVE);
549 LIST_INSERT_HEAD(&mqueue_head, mq, mq_list);
551 getnanotime(&mq->mq_btime);
552 mq->mq_atime = mq->mq_mtime = mq->mq_btime;
555 /* Increase the counters, and make descriptor ready */
560 lockmgr(&mq->mq_mtx, LK_RELEASE);
561 lockmgr(&mqlist_mtx, LK_RELEASE);
564 mqueue_destroy(mq_new);
566 fsetfd(fdp, NULL, mqd);
567 fp->f_ops = &badfileops;
569 fsetfd(fdp, fp, mqd);
570 uap->sysmsg_result = mqd;
573 kfree(name, M_MQBUF);
579 sys_mq_close(struct mq_close_args *uap)
581 return sys_close((void *)uap);
585 * Primary mq_receive1() function.
588 mq_receive1(struct lwp *l, mqd_t mqdes, void *msg_ptr, size_t msg_len,
589 unsigned *msg_prio, struct timespec *ts, ssize_t *mlen)
593 struct mq_msg *msg = NULL;
594 struct mq_attr *mqattr;
598 /* Get the message queue */
599 error = mqueue_get(l, mqdes, &fp);
604 if ((fp->f_flag & FREAD) == 0) {
608 getnanotime(&mq->mq_atime);
609 mqattr = &mq->mq_attrib;
611 /* Check the message size limits */
612 if (msg_len < mqattr->mq_msgsize) {
617 /* Check if queue is empty */
618 while (mqattr->mq_curmsgs == 0) {
621 if (mqattr->mq_flags & O_NONBLOCK) {
626 error = abstimeout2timo(ts, &t);
632 * Block until someone sends the message.
633 * While doing this, notification should not be sent.
635 mqattr->mq_flags |= MQ_RECEIVE;
636 error = lksleep(&mq->mq_send_cv, &mq->mq_mtx, PCATCH, "mqsend", t);
637 mqattr->mq_flags &= ~MQ_RECEIVE;
638 if (error || (mqattr->mq_flags & MQ_UNLINK)) {
639 error = (error == EWOULDBLOCK) ? ETIMEDOUT : EINTR;
646 * Find the highest priority message, and remove it from the queue.
647 * At first, reserved queue is checked, bitmap is next.
649 msg = TAILQ_FIRST(&mq->mq_head[MQ_PQRESQ]);
650 if (__predict_true(msg == NULL)) {
651 idx = ffs(mq->mq_bitmap);
652 msg = TAILQ_FIRST(&mq->mq_head[idx]);
653 KKASSERT(msg != NULL);
657 TAILQ_REMOVE(&mq->mq_head[idx], msg, msg_queue);
659 /* Unmark the bit, if last message. */
660 if (__predict_true(idx) && TAILQ_EMPTY(&mq->mq_head[idx])) {
661 KKASSERT((MQ_PQSIZE - idx) == msg->msg_prio);
662 mq->mq_bitmap &= ~(1 << --idx);
665 /* Decrement the counter and signal waiter, if any */
666 mqattr->mq_curmsgs--;
667 wakeup_one(&mq->mq_recv_cv);
669 /* Ready for sending now */
671 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 */
862 selwakeup(&mq->mq_rsel);
865 lockmgr(&mq->mq_mtx, LK_RELEASE);
869 mqueue_freemsg(msg, size);
871 /* Send the notify, if needed */
872 lwkt_gettoken(&proc_token);
873 /*kpsignal(notify, &ksi, NULL);*/
874 ksignal(notify, mq->mq_sig_notify.sigev_signo);
875 lwkt_reltoken(&proc_token);
882 sys_mq_send(struct mq_send_args *uap)
885 syscallarg(mqd_t) mqdes;
886 syscallarg(const char *) msg_ptr;
887 syscallarg(size_t) msg_len;
888 syscallarg(unsigned) msg_prio;
891 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
892 SCARG(uap, msg_len), SCARG(uap, msg_prio), 0);
896 sys_mq_timedsend(struct mq_timedsend_args *uap)
899 syscallarg(mqd_t) mqdes;
900 syscallarg(const char *) msg_ptr;
901 syscallarg(size_t) msg_len;
902 syscallarg(unsigned) msg_prio;
903 syscallarg(const struct timespec *) abs_timeout;
905 struct timespec ts, *tsp;
908 /* Get and convert time value */
909 if (SCARG(uap, abs_timeout)) {
910 error = copyin(SCARG(uap, abs_timeout), &ts, sizeof(ts));
918 return mq_send1(curthread->td_lwp, SCARG(uap, mqdes), SCARG(uap, msg_ptr),
919 SCARG(uap, msg_len), SCARG(uap, msg_prio), tsp);
923 sys_mq_notify(struct mq_notify_args *uap)
926 syscallarg(mqd_t) mqdes;
927 syscallarg(const struct sigevent *) notification;
934 if (SCARG(uap, notification)) {
935 /* Get the signal from user-space */
936 error = copyin(SCARG(uap, notification), &sig,
937 sizeof(struct sigevent));
940 if (sig.sigev_notify == SIGEV_SIGNAL &&
941 (sig.sigev_signo <= 0 || sig.sigev_signo >= NSIG))
945 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
950 if (SCARG(uap, notification)) {
951 /* Register notification: set the signal and target process */
952 if (mq->mq_notify_proc == NULL) {
953 memcpy(&mq->mq_sig_notify, &sig,
954 sizeof(struct sigevent));
955 mq->mq_notify_proc = curproc;
957 /* Fail if someone else already registered */
961 /* Unregister the notification */
962 mq->mq_notify_proc = NULL;
964 lockmgr(&mq->mq_mtx, LK_RELEASE);
971 sys_mq_getattr(struct mq_getattr_args *uap)
974 syscallarg(mqd_t) mqdes;
975 syscallarg(struct mq_attr *) mqstat;
982 /* Get the message queue */
983 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
987 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
988 lockmgr(&mq->mq_mtx, LK_RELEASE);
991 return copyout(&attr, SCARG(uap, mqstat), sizeof(struct mq_attr));
995 sys_mq_setattr(struct mq_setattr_args *uap)
998 syscallarg(mqd_t) mqdes;
999 syscallarg(const struct mq_attr *) mqstat;
1000 syscallarg(struct mq_attr *) omqstat;
1004 struct mq_attr attr;
1005 int error, nonblock;
1007 error = copyin(SCARG(uap, mqstat), &attr, sizeof(struct mq_attr));
1010 nonblock = (attr.mq_flags & O_NONBLOCK);
1012 /* Get the message queue */
1013 error = mqueue_get(curthread->td_lwp, SCARG(uap, mqdes), &fp);
1018 /* Copy the old attributes, if needed */
1019 if (SCARG(uap, omqstat)) {
1020 memcpy(&attr, &mq->mq_attrib, sizeof(struct mq_attr));
1023 /* Ignore everything, except O_NONBLOCK */
1025 mq->mq_attrib.mq_flags |= O_NONBLOCK;
1027 mq->mq_attrib.mq_flags &= ~O_NONBLOCK;
1029 lockmgr(&mq->mq_mtx, LK_RELEASE);
1033 * Copy the data to the user-space.
1034 * Note: According to POSIX, the new attributes should not be set in
1035 * case of fail - this would be violated.
1037 if (SCARG(uap, omqstat))
1038 error = copyout(&attr, SCARG(uap, omqstat),
1039 sizeof(struct mq_attr));
1045 sys_mq_unlink(struct mq_unlink_args *uap)
1048 syscallarg(const char *) name;
1050 struct thread *td = curthread;
1053 int error, refcnt = 0;
1055 /* Get the name from the user-space */
1056 name = kmalloc(MQ_NAMELEN, M_MQBUF, M_WAITOK | M_ZERO);
1057 error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
1059 kfree(name, M_MQBUF);
1063 /* Lookup for this file */
1064 lockmgr(&mqlist_mtx, LK_EXCLUSIVE);
1065 mq = mqueue_lookup(name);
1071 /* Check the permissions */
1072 if (td->td_ucred->cr_uid != mq->mq_euid &&
1073 priv_check(td, PRIV_ROOT) != 0) {
1074 lockmgr(&mq->mq_mtx, LK_RELEASE);
1079 /* Mark message queue as unlinking, before leaving the window */
1080 mq->mq_attrib.mq_flags |= MQ_UNLINK;
1082 /* Wake up all waiters, if there are such */
1083 wakeup(&mq->mq_send_cv);
1084 wakeup(&mq->mq_recv_cv);
1087 selwakeup(&mq->mq_rsel);
1088 selwakeup(&mq->mq_wsel);
1091 refcnt = mq->mq_refcnt;
1093 LIST_REMOVE(mq, mq_list);
1095 lockmgr(&mq->mq_mtx, LK_RELEASE);
1097 lockmgr(&mqlist_mtx, LK_RELEASE);
1100 * If there are no references - destroy the message
1101 * queue, otherwise, the last mq_close() will do that.
1103 if (error == 0 && refcnt == 0)
1106 kfree(name, M_MQBUF);
1113 SYSCTL_NODE(_kern, OID_AUTO, mqueue,
1114 CTLFLAG_RW, 0, "Message queue options");
1116 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_open_max,
1117 CTLFLAG_RW, &mq_open_max, 0,
1118 "Maximal number of message queue descriptors per process");
1120 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_prio_max,
1121 CTLFLAG_RW, &mq_prio_max, 0,
1122 "Maximal priority of the message");
1124 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_msgsize,
1125 CTLFLAG_RW, &mq_max_msgsize, 0,
1126 "Maximal allowed size of the message");
1128 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_def_maxmsg,
1129 CTLFLAG_RW, &mq_def_maxmsg, 0,
1130 "Default maximal message count");
1132 SYSCTL_INT(_kern_mqueue, OID_AUTO, mq_max_maxmsg,
1133 CTLFLAG_RW, &mq_max_maxmsg, 0,
1134 "Maximal allowed message count");
1136 SYSINIT(sys_mqueue_init, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, mqueue_sysinit, NULL);