1 /* $FreeBSD: src/sys/kern/sysv_msg.c,v 1.23.2.5 2002/12/31 08:54:53 maxim Exp $ */
2 /* $DragonFly: src/sys/kern/sysv_msg.c,v 1.18 2008/01/06 16:55:51 swildner Exp $ */
5 * Implementation of SVID messages
7 * Author: Daniel Boulet
9 * Copyright 1993 Daniel Boulet and RTMX Inc.
11 * This system call was implemented by Daniel Boulet under contract from RTMX.
13 * Redistribution and use in source forms, with and without modification,
14 * are permitted provided that this entire comment appears intact.
16 * Redistribution in binary form may occur without any restrictions.
17 * Obviously, it would be nice if you gave credit where credit is due
18 * but requiring it would be too onerous.
20 * This software is provided ``AS IS'' without any warranties of any kind.
23 #include "opt_sysvipc.h"
25 #include <sys/param.h>
26 #include <sys/systm.h>
27 #include <sys/sysproto.h>
28 #include <sys/kernel.h>
31 #include <sys/sysent.h>
32 #include <sys/sysctl.h>
33 #include <sys/malloc.h>
36 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
38 static void msginit (void *);
43 static void msg_freehdr (struct msg *msghdr);
45 /* XXX casting to (sy_call_t *) is bogus, as usual. */
46 static sy_call_t *msgcalls[] = {
47 (sy_call_t *)sys_msgctl, (sy_call_t *)sys_msgget,
48 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
52 struct msg *msg_next; /* next msg in the chain */
53 long msg_type; /* type of this message */
54 /* >0 -> type of this message */
55 /* 0 -> free header */
56 u_short msg_ts; /* size of this message */
57 short msg_spot; /* location of start of msg in buffer */
62 #define MSGSSZ 8 /* Each segment must be 2^N long */
65 #define MSGSEG 2048 /* must be less than 32767 */
67 #define MSGMAX (MSGSSZ*MSGSEG)
69 #define MSGMNB 2048 /* max # of bytes in a queue */
79 * Based on the configuration parameters described in an SVR2 (yes, two)
80 * config(1m) man page.
82 * Each message is broken up and stored in segments that are msgssz bytes
83 * long. For efficiency reasons, this should be a power of two. Also,
84 * it doesn't make sense if it is less than 8 or greater than about 256.
85 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
86 * two between 8 and 1024 inclusive (and panic's if it isn't).
88 struct msginfo msginfo = {
89 MSGMAX, /* max chars in a message */
90 MSGMNI, /* # of message queue identifiers */
91 MSGMNB, /* max chars in a queue */
92 MSGTQL, /* max messages in system */
93 MSGSSZ, /* size of a message segment */
94 /* (must be small power of 2 greater than 4) */
95 MSGSEG /* number of message segments */
99 * macros to convert between msqid_ds's and msqid's.
100 * (specific to this implementation)
102 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
103 #define MSQID_IX(id) ((id) & 0xffff)
104 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
107 * The rest of this file is specific to this particular implementation.
111 short next; /* next segment in buffer */
112 /* -1 -> available */
113 /* 0..(MSGSEG-1) -> index of next segment */
116 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
118 static int nfree_msgmaps; /* # of free map entries */
119 static short free_msgmaps; /* head of linked list of free map entries */
120 static struct msg *free_msghdrs;/* list of free msg headers */
121 static char *msgpool; /* MSGMAX byte long msg buffer pool */
122 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
123 static struct msg *msghdrs; /* MSGTQL msg headers */
124 static struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
131 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
132 msgpool = kmalloc(msginfo.msgmax, M_MSG, M_WAITOK);
133 msgmaps = kmalloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
134 msghdrs = kmalloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
135 msqids = kmalloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK);
138 * msginfo.msgssz should be a power of two for efficiency reasons.
139 * It is also pretty silly if msginfo.msgssz is less than 8
140 * or greater than about 256 so ...
144 while (i < 1024 && i != msginfo.msgssz)
146 if (i != msginfo.msgssz) {
147 kprintf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
149 panic("msginfo.msgssz not a small power of 2");
152 if (msginfo.msgseg > 32767) {
153 kprintf("msginfo.msgseg=%d\n", msginfo.msgseg);
154 panic("msginfo.msgseg > 32767");
158 panic("msgmaps is NULL");
160 for (i = 0; i < msginfo.msgseg; i++) {
162 msgmaps[i-1].next = i;
163 msgmaps[i].next = -1; /* implies entry is available */
166 nfree_msgmaps = msginfo.msgseg;
169 panic("msghdrs is NULL");
171 for (i = 0; i < msginfo.msgtql; i++) {
172 msghdrs[i].msg_type = 0;
174 msghdrs[i-1].msg_next = &msghdrs[i];
175 msghdrs[i].msg_next = NULL;
177 free_msghdrs = &msghdrs[0];
180 panic("msqids is NULL");
182 for (i = 0; i < msginfo.msgmni; i++) {
183 msqids[i].msg_qbytes = 0; /* implies entry is available */
184 msqids[i].msg_perm.seq = 0; /* reset to a known value */
185 msqids[i].msg_perm.mode = 0;
188 SYSINIT(sysv_msg, SI_SUB_SYSV_MSG, SI_ORDER_FIRST, msginit, NULL)
191 * Entry point for all MSG calls
193 * msgsys_args(int which, int a2, ...) (VARARGS)
196 sys_msgsys(struct msgsys_args *uap)
198 struct proc *p = curproc;
199 unsigned int which = (unsigned int)uap->which;
201 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
204 if (which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
206 bcopy(&uap->a2, &uap->which,
207 sizeof(struct msgsys_args) - offsetof(struct msgsys_args, a2));
208 return ((*msgcalls[which])(uap));
212 msg_freehdr(struct msg *msghdr)
214 while (msghdr->msg_ts > 0) {
216 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
217 panic("msghdr->msg_spot out of range");
218 next = msgmaps[msghdr->msg_spot].next;
219 msgmaps[msghdr->msg_spot].next = free_msgmaps;
220 free_msgmaps = msghdr->msg_spot;
222 msghdr->msg_spot = next;
223 if (msghdr->msg_ts >= msginfo.msgssz)
224 msghdr->msg_ts -= msginfo.msgssz;
228 if (msghdr->msg_spot != -1)
229 panic("msghdr->msg_spot != -1");
230 msghdr->msg_next = free_msghdrs;
231 free_msghdrs = msghdr;
235 sys_msgctl(struct msgctl_args *uap)
237 struct thread *td = curthread;
238 struct proc *p = td->td_proc;
239 int msqid = uap->msqid;
241 struct msqid_ds *user_msqptr = uap->buf;
243 struct msqid_ds msqbuf;
244 struct msqid_ds *msqptr;
247 kprintf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr);
250 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
253 msqid = IPCID_TO_IX(msqid);
255 if (msqid < 0 || msqid >= msginfo.msgmni) {
257 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
263 msqptr = &msqids[msqid];
265 if (msqptr->msg_qbytes == 0) {
267 kprintf("no such msqid\n");
271 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
273 kprintf("wrong sequence number\n");
286 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)))
288 /* Free the message headers */
289 msghdr = msqptr->msg_first;
290 while (msghdr != NULL) {
291 struct msg *msghdr_tmp;
293 /* Free the segments of each message */
294 msqptr->msg_cbytes -= msghdr->msg_ts;
297 msghdr = msghdr->msg_next;
298 msg_freehdr(msghdr_tmp);
301 if (msqptr->msg_cbytes != 0)
302 panic("msg_cbytes is screwed up");
303 if (msqptr->msg_qnum != 0)
304 panic("msg_qnum is screwed up");
306 msqptr->msg_qbytes = 0; /* Mark it as free */
308 wakeup((caddr_t)msqptr);
314 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)))
316 if ((eval = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0)
318 if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
323 if (msqbuf.msg_qbytes > msginfo.msgmnb) {
325 kprintf("can't increase msg_qbytes beyond %d (truncating)\n",
328 msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
330 if (msqbuf.msg_qbytes == 0) {
332 kprintf("can't reduce msg_qbytes to 0\n");
334 return(EINVAL); /* non-standard errno! */
336 msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */
337 msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */
338 msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
339 (msqbuf.msg_perm.mode & 0777);
340 msqptr->msg_qbytes = msqbuf.msg_qbytes;
341 msqptr->msg_ctime = time_second;
345 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
347 kprintf("requester doesn't have read access\n");
351 eval = copyout((caddr_t)msqptr, user_msqptr,
352 sizeof(struct msqid_ds));
357 kprintf("invalid command %d\n", cmd);
363 uap->sysmsg_result = rval;
368 sys_msgget(struct msgget_args *uap)
370 struct proc *p = curproc;
373 int msgflg = uap->msgflg;
374 struct ucred *cred = p->p_ucred;
375 struct msqid_ds *msqptr = NULL;
378 kprintf("msgget(0x%x, 0%o)\n", key, msgflg);
381 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
384 if (key != IPC_PRIVATE) {
385 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
386 msqptr = &msqids[msqid];
387 if (msqptr->msg_qbytes != 0 &&
388 msqptr->msg_perm.key == key)
391 if (msqid < msginfo.msgmni) {
393 kprintf("found public key\n");
395 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
397 kprintf("not exclusive\n");
401 if ((eval = ipcperm(p, &msqptr->msg_perm, msgflg & 0700 ))) {
403 kprintf("requester doesn't have 0%o access\n",
413 kprintf("need to allocate the msqid_ds\n");
415 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
416 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
418 * Look for an unallocated and unlocked msqid_ds.
419 * msqid_ds's can be locked by msgsnd or msgrcv while
420 * they are copying the message in/out. We can't
421 * re-use the entry until they release it.
423 msqptr = &msqids[msqid];
424 if (msqptr->msg_qbytes == 0 &&
425 (msqptr->msg_perm.mode & MSG_LOCKED) == 0)
428 if (msqid == msginfo.msgmni) {
430 kprintf("no more msqid_ds's available\n");
435 kprintf("msqid %d is available\n", msqid);
437 msqptr->msg_perm.key = key;
438 msqptr->msg_perm.cuid = cred->cr_uid;
439 msqptr->msg_perm.uid = cred->cr_uid;
440 msqptr->msg_perm.cgid = cred->cr_gid;
441 msqptr->msg_perm.gid = cred->cr_gid;
442 msqptr->msg_perm.mode = (msgflg & 0777);
443 /* Make sure that the returned msqid is unique */
444 msqptr->msg_perm.seq = (msqptr->msg_perm.seq + 1) & 0x7fff;
445 msqptr->msg_first = NULL;
446 msqptr->msg_last = NULL;
447 msqptr->msg_cbytes = 0;
448 msqptr->msg_qnum = 0;
449 msqptr->msg_qbytes = msginfo.msgmnb;
450 msqptr->msg_lspid = 0;
451 msqptr->msg_lrpid = 0;
452 msqptr->msg_stime = 0;
453 msqptr->msg_rtime = 0;
454 msqptr->msg_ctime = time_second;
457 kprintf("didn't find it and wasn't asked to create it\n");
463 /* Construct the unique msqid */
464 uap->sysmsg_result = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
469 sys_msgsnd(struct msgsnd_args *uap)
471 struct proc *p = curproc;
472 int msqid = uap->msqid;
473 void *user_msgp = uap->msgp;
474 size_t msgsz = uap->msgsz;
475 int msgflg = uap->msgflg;
476 int segs_needed, eval;
477 struct msqid_ds *msqptr;
482 kprintf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz,
486 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
489 msqid = IPCID_TO_IX(msqid);
491 if (msqid < 0 || msqid >= msginfo.msgmni) {
493 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
499 msqptr = &msqids[msqid];
500 if (msqptr->msg_qbytes == 0) {
502 kprintf("no such message queue id\n");
506 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
508 kprintf("wrong sequence number\n");
513 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_W))) {
515 kprintf("requester doesn't have write access\n");
520 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
522 kprintf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
526 int need_more_resources = 0;
530 * (inside this loop in case msg_qbytes changes while we sleep)
533 if (msgsz > msqptr->msg_qbytes) {
535 kprintf("msgsz > msqptr->msg_qbytes\n");
540 if (msqptr->msg_perm.mode & MSG_LOCKED) {
542 kprintf("msqid is locked\n");
544 need_more_resources = 1;
546 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
548 kprintf("msgsz + msg_cbytes > msg_qbytes\n");
550 need_more_resources = 1;
552 if (segs_needed > nfree_msgmaps) {
554 kprintf("segs_needed > nfree_msgmaps\n");
556 need_more_resources = 1;
558 if (free_msghdrs == NULL) {
560 kprintf("no more msghdrs\n");
562 need_more_resources = 1;
565 if (need_more_resources) {
568 if ((msgflg & IPC_NOWAIT) != 0) {
570 kprintf("need more resources but caller doesn't want to wait\n");
575 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
577 kprintf("we don't own the msqid_ds\n");
581 /* Force later arrivals to wait for our
584 kprintf("we own the msqid_ds\n");
586 msqptr->msg_perm.mode |= MSG_LOCKED;
590 kprintf("goodnight\n");
592 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
594 kprintf("good morning, eval=%d\n", eval);
597 msqptr->msg_perm.mode &= ~MSG_LOCKED;
600 kprintf("msgsnd: interrupted system call\n");
606 * Make sure that the msq queue still exists
609 if (msqptr->msg_qbytes == 0) {
611 kprintf("msqid deleted\n");
618 kprintf("got all the resources that we need\n");
625 * We have the resources that we need.
629 if (msqptr->msg_perm.mode & MSG_LOCKED)
630 panic("msg_perm.mode & MSG_LOCKED");
631 if (segs_needed > nfree_msgmaps)
632 panic("segs_needed > nfree_msgmaps");
633 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
634 panic("msgsz + msg_cbytes > msg_qbytes");
635 if (free_msghdrs == NULL)
636 panic("no more msghdrs");
639 * Re-lock the msqid_ds in case we page-fault when copying in the
643 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
644 panic("msqid_ds is already locked");
645 msqptr->msg_perm.mode |= MSG_LOCKED;
648 * Allocate a message header
651 msghdr = free_msghdrs;
652 free_msghdrs = msghdr->msg_next;
653 msghdr->msg_spot = -1;
654 msghdr->msg_ts = msgsz;
657 * Allocate space for the message
660 while (segs_needed > 0) {
661 if (nfree_msgmaps <= 0)
662 panic("not enough msgmaps");
663 if (free_msgmaps == -1)
664 panic("nil free_msgmaps");
667 panic("next too low #1");
668 if (next >= msginfo.msgseg)
669 panic("next out of range #1");
671 kprintf("allocating segment %d to message\n", next);
673 free_msgmaps = msgmaps[next].next;
675 msgmaps[next].next = msghdr->msg_spot;
676 msghdr->msg_spot = next;
681 * Copy in the message type
684 if ((eval = copyin(user_msgp, &msghdr->msg_type,
685 sizeof(msghdr->msg_type))) != 0) {
687 kprintf("error %d copying the message type\n", eval);
690 msqptr->msg_perm.mode &= ~MSG_LOCKED;
691 wakeup((caddr_t)msqptr);
694 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
697 * Validate the message type
700 if (msghdr->msg_type < 1) {
702 msqptr->msg_perm.mode &= ~MSG_LOCKED;
703 wakeup((caddr_t)msqptr);
705 kprintf("mtype (%d) < 1\n", msghdr->msg_type);
711 * Copy in the message body
714 next = msghdr->msg_spot;
717 if (msgsz > msginfo.msgssz)
718 tlen = msginfo.msgssz;
722 panic("next too low #2");
723 if (next >= msginfo.msgseg)
724 panic("next out of range #2");
725 if ((eval = copyin(user_msgp, &msgpool[next * msginfo.msgssz],
728 kprintf("error %d copying in message segment\n", eval);
731 msqptr->msg_perm.mode &= ~MSG_LOCKED;
732 wakeup((caddr_t)msqptr);
736 user_msgp = (char *)user_msgp + tlen;
737 next = msgmaps[next].next;
740 panic("didn't use all the msg segments");
743 * We've got the message. Unlock the msqid_ds.
746 msqptr->msg_perm.mode &= ~MSG_LOCKED;
749 * Make sure that the msqid_ds is still allocated.
752 if (msqptr->msg_qbytes == 0) {
754 wakeup((caddr_t)msqptr);
759 * Put the message into the queue
762 if (msqptr->msg_first == NULL) {
763 msqptr->msg_first = msghdr;
764 msqptr->msg_last = msghdr;
766 msqptr->msg_last->msg_next = msghdr;
767 msqptr->msg_last = msghdr;
769 msqptr->msg_last->msg_next = NULL;
771 msqptr->msg_cbytes += msghdr->msg_ts;
773 msqptr->msg_lspid = p->p_pid;
774 msqptr->msg_stime = time_second;
776 wakeup((caddr_t)msqptr);
777 uap->sysmsg_result = 0;
782 sys_msgrcv(struct msgrcv_args *uap)
784 struct proc *p = curproc;
785 int msqid = uap->msqid;
786 void *user_msgp = uap->msgp;
787 size_t msgsz = uap->msgsz;
788 long msgtyp = uap->msgtyp;
789 int msgflg = uap->msgflg;
791 struct msqid_ds *msqptr;
797 kprintf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp,
798 msgsz, msgtyp, msgflg);
801 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
804 msqid = IPCID_TO_IX(msqid);
806 if (msqid < 0 || msqid >= msginfo.msgmni) {
808 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
814 msqptr = &msqids[msqid];
815 if (msqptr->msg_qbytes == 0) {
817 kprintf("no such message queue id\n");
821 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
823 kprintf("wrong sequence number\n");
828 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
830 kprintf("requester doesn't have read access\n");
836 while (msghdr == NULL) {
838 msghdr = msqptr->msg_first;
839 if (msghdr != NULL) {
840 if (msgsz < msghdr->msg_ts &&
841 (msgflg & MSG_NOERROR) == 0) {
843 kprintf("first message on the queue is too big (want %d, got %d)\n",
844 msgsz, msghdr->msg_ts);
848 if (msqptr->msg_first == msqptr->msg_last) {
849 msqptr->msg_first = NULL;
850 msqptr->msg_last = NULL;
852 msqptr->msg_first = msghdr->msg_next;
853 if (msqptr->msg_first == NULL)
854 panic("msg_first/last screwed up #1");
858 struct msg *previous;
862 prev = &(msqptr->msg_first);
863 while ((msghdr = *prev) != NULL) {
865 * Is this message's type an exact match or is
866 * this message's type less than or equal to
867 * the absolute value of a negative msgtyp?
868 * Note that the second half of this test can
869 * NEVER be true if msgtyp is positive since
870 * msg_type is always positive!
873 if (msgtyp == msghdr->msg_type ||
874 msghdr->msg_type <= -msgtyp) {
876 kprintf("found message type %d, requested %d\n",
877 msghdr->msg_type, msgtyp);
879 if (msgsz < msghdr->msg_ts &&
880 (msgflg & MSG_NOERROR) == 0) {
882 kprintf("requested message on the queue is too big (want %d, got %d)\n",
883 msgsz, msghdr->msg_ts);
887 *prev = msghdr->msg_next;
888 if (msghdr == msqptr->msg_last) {
889 if (previous == NULL) {
892 panic("msg_first/last screwed up #2");
900 panic("msg_first/last screwed up #3");
908 prev = &(msghdr->msg_next);
913 * We've either extracted the msghdr for the appropriate
914 * message or there isn't one.
915 * If there is one then bail out of this loop.
922 * Hmph! No message found. Does the user want to wait?
925 if ((msgflg & IPC_NOWAIT) != 0) {
927 kprintf("no appropriate message found (msgtyp=%d)\n",
930 /* The SVID says to return ENOMSG. */
934 /* Unfortunately, BSD doesn't define that code yet! */
940 * Wait for something to happen
944 kprintf("msgrcv: goodnight\n");
946 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
948 kprintf("msgrcv: good morning (eval=%d)\n", eval);
953 kprintf("msgsnd: interrupted system call\n");
959 * Make sure that the msq queue still exists
962 if (msqptr->msg_qbytes == 0 ||
963 msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
965 kprintf("msqid deleted\n");
972 * Return the message to the user.
974 * First, do the bookkeeping (before we risk being interrupted).
977 msqptr->msg_cbytes -= msghdr->msg_ts;
979 msqptr->msg_lrpid = p->p_pid;
980 msqptr->msg_rtime = time_second;
983 * Make msgsz the actual amount that we'll be returning.
984 * Note that this effectively truncates the message if it is too long
985 * (since msgsz is never increased).
989 kprintf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
992 if (msgsz > msghdr->msg_ts)
993 msgsz = msghdr->msg_ts;
996 * Return the type to the user.
999 eval = copyout((caddr_t)&(msghdr->msg_type), user_msgp,
1000 sizeof(msghdr->msg_type));
1003 kprintf("error (%d) copying out message type\n", eval);
1005 msg_freehdr(msghdr);
1006 wakeup((caddr_t)msqptr);
1009 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
1012 * Return the segments to the user
1015 next = msghdr->msg_spot;
1016 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1019 if (msgsz - len > msginfo.msgssz)
1020 tlen = msginfo.msgssz;
1024 panic("next too low #3");
1025 if (next >= msginfo.msgseg)
1026 panic("next out of range #3");
1027 eval = copyout((caddr_t)&msgpool[next * msginfo.msgssz],
1031 kprintf("error (%d) copying out message segment\n",
1034 msg_freehdr(msghdr);
1035 wakeup((caddr_t)msqptr);
1038 user_msgp = (char *)user_msgp + tlen;
1039 next = msgmaps[next].next;
1043 * Done, return the actual number of bytes copied out.
1046 msg_freehdr(msghdr);
1047 wakeup((caddr_t)msqptr);
1048 uap->sysmsg_result = msgsz;
1053 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1056 return (SYSCTL_OUT(req, msqids,
1057 sizeof(struct msqid_ds) * msginfo.msgmni));
1060 TUNABLE_INT("kern.ipc.msgseg", &msginfo.msgseg);
1061 TUNABLE_INT("kern.ipc.msgssz", &msginfo.msgssz);
1062 TUNABLE_INT("kern.ipc.msgmni", &msginfo.msgmni);
1064 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, "");
1065 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0, "");
1066 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0, "");
1067 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0, "");
1068 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0, "");
1069 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0, "");
1070 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1071 NULL, 0, sysctl_msqids, "", "Message queue IDs");