1 /* $FreeBSD: src/sys/kern/sysv_msg.c,v 1.23.2.5 2002/12/31 08:54:53 maxim Exp $ */
4 * Implementation of SVID messages
6 * Author: Daniel Boulet
8 * Copyright 1993 Daniel Boulet and RTMX Inc.
10 * This system call was implemented by Daniel Boulet under contract from RTMX.
12 * Redistribution and use in source forms, with and without modification,
13 * are permitted provided that this entire comment appears intact.
15 * Redistribution in binary form may occur without any restrictions.
16 * Obviously, it would be nice if you gave credit where credit is due
17 * but requiring it would be too onerous.
19 * This software is provided ``AS IS'' without any warranties of any kind.
22 #include "opt_sysvipc.h"
24 #include <sys/param.h>
25 #include <sys/systm.h>
26 #include <sys/sysproto.h>
27 #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);
46 struct msg *msg_next; /* next msg in the chain */
47 long msg_type; /* type of this message */
48 /* >0 -> type of this message */
49 /* 0 -> free header */
50 u_short msg_ts; /* size of this message */
51 short msg_spot; /* location of start of msg in buffer */
56 #define MSGSSZ 8 /* Each segment must be 2^N long */
59 #define MSGSEG 2048 /* must be less than 32767 */
61 #define MSGMAX (MSGSSZ*MSGSEG)
63 #define MSGMNB 2048 /* max # of bytes in a queue */
73 * Based on the configuration parameters described in an SVR2 (yes, two)
74 * config(1m) man page.
76 * Each message is broken up and stored in segments that are msgssz bytes
77 * long. For efficiency reasons, this should be a power of two. Also,
78 * it doesn't make sense if it is less than 8 or greater than about 256.
79 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
80 * two between 8 and 1024 inclusive (and panic's if it isn't).
82 struct msginfo msginfo = {
83 MSGMAX, /* max chars in a message */
84 MSGMNI, /* # of message queue identifiers */
85 MSGMNB, /* max chars in a queue */
86 MSGTQL, /* max messages in system */
87 MSGSSZ, /* size of a message segment */
88 /* (must be small power of 2 greater than 4) */
89 MSGSEG /* number of message segments */
93 * macros to convert between msqid_ds's and msqid's.
94 * (specific to this implementation)
96 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
97 #define MSQID_IX(id) ((id) & 0xffff)
98 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
101 * The rest of this file is specific to this particular implementation.
105 short next; /* next segment in buffer */
106 /* -1 -> available */
107 /* 0..(MSGSEG-1) -> index of next segment */
110 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
112 static int nfree_msgmaps; /* # of free map entries */
113 static short free_msgmaps; /* head of linked list of free map entries */
114 static struct msg *free_msghdrs;/* list of free msg headers */
115 static char *msgpool; /* MSGMAX byte long msg buffer pool */
116 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
117 static struct msg *msghdrs; /* MSGTQL msg headers */
118 static struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
119 static struct lwkt_token msg_token = LWKT_TOKEN_INITIALIZER(msg_token);
126 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
127 msgpool = kmalloc(msginfo.msgmax, M_MSG, M_WAITOK);
128 msgmaps = kmalloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
129 msghdrs = kmalloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
130 msqids = kmalloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK);
133 * msginfo.msgssz should be a power of two for efficiency reasons.
134 * It is also pretty silly if msginfo.msgssz is less than 8
135 * or greater than about 256 so ...
139 while (i < 1024 && i != msginfo.msgssz)
141 if (i != msginfo.msgssz) {
142 kprintf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
144 panic("msginfo.msgssz not a small power of 2");
147 if (msginfo.msgseg > 32767) {
148 kprintf("msginfo.msgseg=%d\n", msginfo.msgseg);
149 panic("msginfo.msgseg > 32767");
152 for (i = 0; i < msginfo.msgseg; i++) {
154 msgmaps[i-1].next = i;
155 msgmaps[i].next = -1; /* implies entry is available */
158 nfree_msgmaps = msginfo.msgseg;
160 for (i = 0; i < msginfo.msgtql; i++) {
161 msghdrs[i].msg_type = 0;
163 msghdrs[i-1].msg_next = &msghdrs[i];
164 msghdrs[i].msg_next = NULL;
166 free_msghdrs = &msghdrs[0];
168 for (i = 0; i < msginfo.msgmni; i++) {
169 msqids[i].msg_qbytes = 0; /* implies entry is available */
170 msqids[i].msg_perm.seq = 0; /* reset to a known value */
171 msqids[i].msg_perm.mode = 0;
174 SYSINIT(sysv_msg, SI_SUB_SYSV_MSG, SI_ORDER_FIRST, msginit, NULL);
177 msg_freehdr(struct msg *msghdr)
179 while (msghdr->msg_ts > 0) {
181 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
182 panic("msghdr->msg_spot out of range");
183 next = msgmaps[msghdr->msg_spot].next;
184 msgmaps[msghdr->msg_spot].next = free_msgmaps;
185 free_msgmaps = msghdr->msg_spot;
187 msghdr->msg_spot = next;
188 if (msghdr->msg_ts >= msginfo.msgssz)
189 msghdr->msg_ts -= msginfo.msgssz;
193 if (msghdr->msg_spot != -1)
194 panic("msghdr->msg_spot != -1");
195 msghdr->msg_next = free_msghdrs;
196 free_msghdrs = msghdr;
203 sys_msgctl(struct msgctl_args *uap)
205 struct thread *td = curthread;
206 struct proc *p = td->td_proc;
207 int msqid = uap->msqid;
209 struct msqid_ds *user_msqptr = uap->buf;
211 struct msqid_ds msqbuf;
212 struct msqid_ds *msqptr;
215 kprintf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr);
218 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
221 lwkt_gettoken(&msg_token);
222 msqid = IPCID_TO_IX(msqid);
224 if (msqid < 0 || msqid >= msginfo.msgmni) {
226 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
233 msqptr = &msqids[msqid];
235 if (msqptr->msg_qbytes == 0) {
237 kprintf("no such msqid\n");
242 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
244 kprintf("wrong sequence number\n");
256 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)) != 0)
258 /* Free the message headers */
259 msghdr = msqptr->msg_first;
260 while (msghdr != NULL) {
261 struct msg *msghdr_tmp;
263 /* Free the segments of each message */
264 msqptr->msg_cbytes -= msghdr->msg_ts;
267 msghdr = msghdr->msg_next;
268 msg_freehdr(msghdr_tmp);
271 if (msqptr->msg_cbytes != 0)
272 panic("msg_cbytes is screwed up");
273 if (msqptr->msg_qnum != 0)
274 panic("msg_qnum is screwed up");
276 msqptr->msg_qbytes = 0; /* Mark it as free */
278 wakeup((caddr_t)msqptr);
284 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)) != 0)
286 if ((eval = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0)
288 if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
289 eval = priv_check(td, PRIV_ROOT);
293 if (msqbuf.msg_qbytes > msginfo.msgmnb) {
295 kprintf("can't increase msg_qbytes beyond %d (truncating)\n",
298 msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
300 if (msqbuf.msg_qbytes == 0) {
302 kprintf("can't reduce msg_qbytes to 0\n");
304 eval = EINVAL; /* non-standard errno! */
307 msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */
308 msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */
309 msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
310 (msqbuf.msg_perm.mode & 0777);
311 msqptr->msg_qbytes = msqbuf.msg_qbytes;
312 msqptr->msg_ctime = time_second;
316 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
318 kprintf("requester doesn't have read access\n");
323 eval = copyout(msqptr, user_msqptr, sizeof(struct msqid_ds));
328 kprintf("invalid command %d\n", cmd);
334 lwkt_reltoken(&msg_token);
336 uap->sysmsg_result = rval;
344 sys_msgget(struct msgget_args *uap)
346 struct thread *td = curthread;
349 int msgflg = uap->msgflg;
350 struct ucred *cred = td->td_ucred;
351 struct msqid_ds *msqptr = NULL;
354 kprintf("msgget(0x%x, 0%o)\n", key, msgflg);
356 if (!jail_sysvipc_allowed && cred->cr_prison != NULL)
360 lwkt_gettoken(&msg_token);
362 if (key != IPC_PRIVATE) {
363 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
364 msqptr = &msqids[msqid];
365 if (msqptr->msg_qbytes != 0 &&
366 msqptr->msg_perm.key == key)
369 if (msqid < msginfo.msgmni) {
371 kprintf("found public key\n");
373 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
375 kprintf("not exclusive\n");
380 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, msgflg & 0700 ))) {
382 kprintf("requester doesn't have 0%o access\n",
392 kprintf("need to allocate the msqid_ds\n");
394 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
395 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
397 * Look for an unallocated and unlocked msqid_ds.
398 * msqid_ds's can be locked by msgsnd or msgrcv while
399 * they are copying the message in/out. We can't
400 * re-use the entry until they release it.
402 msqptr = &msqids[msqid];
403 if (msqptr->msg_qbytes == 0 &&
404 (msqptr->msg_perm.mode & MSG_LOCKED) == 0)
407 if (msqid == msginfo.msgmni) {
409 kprintf("no more msqid_ds's available\n");
415 kprintf("msqid %d is available\n", msqid);
417 msqptr->msg_perm.key = key;
418 msqptr->msg_perm.cuid = cred->cr_uid;
419 msqptr->msg_perm.uid = cred->cr_uid;
420 msqptr->msg_perm.cgid = cred->cr_gid;
421 msqptr->msg_perm.gid = cred->cr_gid;
422 msqptr->msg_perm.mode = (msgflg & 0777);
423 /* Make sure that the returned msqid is unique */
424 msqptr->msg_perm.seq = (msqptr->msg_perm.seq + 1) & 0x7fff;
425 msqptr->msg_first = NULL;
426 msqptr->msg_last = NULL;
427 msqptr->msg_cbytes = 0;
428 msqptr->msg_qnum = 0;
429 msqptr->msg_qbytes = msginfo.msgmnb;
430 msqptr->msg_lspid = 0;
431 msqptr->msg_lrpid = 0;
432 msqptr->msg_stime = 0;
433 msqptr->msg_rtime = 0;
434 msqptr->msg_ctime = time_second;
437 kprintf("didn't find it and wasn't asked to create it\n");
443 lwkt_reltoken(&msg_token);
444 /* Construct the unique msqid */
446 uap->sysmsg_result = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
454 sys_msgsnd(struct msgsnd_args *uap)
456 struct thread *td = curthread;
457 int msqid = uap->msqid;
458 const void *user_msgp = uap->msgp;
459 size_t msgsz = uap->msgsz;
460 int msgflg = uap->msgflg;
461 int segs_needed, eval;
462 struct msqid_ds *msqptr;
467 kprintf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz,
471 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
474 lwkt_gettoken(&msg_token);
475 msqid = IPCID_TO_IX(msqid);
477 if (msqid < 0 || msqid >= msginfo.msgmni) {
479 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
486 msqptr = &msqids[msqid];
487 if (msqptr->msg_qbytes == 0) {
489 kprintf("no such message queue id\n");
494 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
496 kprintf("wrong sequence number\n");
502 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, IPC_W))) {
504 kprintf("requester doesn't have write access\n");
510 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
512 kprintf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
516 int need_more_resources = 0;
520 * (inside this loop in case msg_qbytes changes while we sleep)
523 if (msgsz > msqptr->msg_qbytes) {
525 kprintf("msgsz > msqptr->msg_qbytes\n");
531 if (msqptr->msg_perm.mode & MSG_LOCKED) {
533 kprintf("msqid is locked\n");
535 need_more_resources = 1;
537 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
539 kprintf("msgsz + msg_cbytes > msg_qbytes\n");
541 need_more_resources = 1;
543 if (segs_needed > nfree_msgmaps) {
545 kprintf("segs_needed > nfree_msgmaps\n");
547 need_more_resources = 1;
549 if (free_msghdrs == NULL) {
551 kprintf("no more msghdrs\n");
553 need_more_resources = 1;
556 if (need_more_resources) {
559 if ((msgflg & IPC_NOWAIT) != 0) {
561 kprintf("need more resources but caller doesn't want to wait\n");
567 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
569 kprintf("we don't own the msqid_ds\n");
573 /* Force later arrivals to wait for our
576 kprintf("we own the msqid_ds\n");
578 msqptr->msg_perm.mode |= MSG_LOCKED;
582 kprintf("goodnight\n");
584 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
586 kprintf("good morning, eval=%d\n", eval);
589 msqptr->msg_perm.mode &= ~MSG_LOCKED;
592 kprintf("msgsnd: interrupted system call\n");
599 * Make sure that the msq queue still exists
602 if (msqptr->msg_qbytes == 0) {
604 kprintf("msqid deleted\n");
612 kprintf("got all the resources that we need\n");
619 * We have the resources that we need.
623 if (msqptr->msg_perm.mode & MSG_LOCKED)
624 panic("msg_perm.mode & MSG_LOCKED");
625 if (segs_needed > nfree_msgmaps)
626 panic("segs_needed > nfree_msgmaps");
627 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
628 panic("msgsz + msg_cbytes > msg_qbytes");
629 if (free_msghdrs == NULL)
630 panic("no more msghdrs");
633 * Re-lock the msqid_ds in case we page-fault when copying in the
637 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
638 panic("msqid_ds is already locked");
639 msqptr->msg_perm.mode |= MSG_LOCKED;
642 * Allocate a message header
645 msghdr = free_msghdrs;
646 free_msghdrs = msghdr->msg_next;
647 msghdr->msg_spot = -1;
648 msghdr->msg_ts = msgsz;
651 * Allocate space for the message
654 while (segs_needed > 0) {
655 if (nfree_msgmaps <= 0)
656 panic("not enough msgmaps");
657 if (free_msgmaps == -1)
658 panic("nil free_msgmaps");
661 panic("next too low #1");
662 if (next >= msginfo.msgseg)
663 panic("next out of range #1");
665 kprintf("allocating segment %d to message\n", next);
667 free_msgmaps = msgmaps[next].next;
669 msgmaps[next].next = msghdr->msg_spot;
670 msghdr->msg_spot = next;
675 * Copy in the message type
678 if ((eval = copyin(user_msgp, &msghdr->msg_type,
679 sizeof(msghdr->msg_type))) != 0) {
681 kprintf("error %d copying the message type\n", eval);
684 msqptr->msg_perm.mode &= ~MSG_LOCKED;
685 wakeup((caddr_t)msqptr);
688 user_msgp = (const char *)user_msgp + sizeof(msghdr->msg_type);
691 * Validate the message type
694 if (msghdr->msg_type < 1) {
696 msqptr->msg_perm.mode &= ~MSG_LOCKED;
697 wakeup((caddr_t)msqptr);
699 kprintf("mtype (%d) < 1\n", msghdr->msg_type);
706 * Copy in the message body
709 next = msghdr->msg_spot;
712 if (msgsz > msginfo.msgssz)
713 tlen = msginfo.msgssz;
717 panic("next too low #2");
718 if (next >= msginfo.msgseg)
719 panic("next out of range #2");
720 if ((eval = copyin(user_msgp, &msgpool[next * msginfo.msgssz],
723 kprintf("error %d copying in message segment\n", eval);
726 msqptr->msg_perm.mode &= ~MSG_LOCKED;
727 wakeup((caddr_t)msqptr);
731 user_msgp = (const char *)user_msgp + tlen;
732 next = msgmaps[next].next;
735 panic("didn't use all the msg segments");
738 * We've got the message. Unlock the msqid_ds.
741 msqptr->msg_perm.mode &= ~MSG_LOCKED;
744 * Make sure that the msqid_ds is still allocated.
747 if (msqptr->msg_qbytes == 0) {
749 wakeup((caddr_t)msqptr);
755 * Put the message into the queue
758 if (msqptr->msg_first == NULL) {
759 msqptr->msg_first = msghdr;
760 msqptr->msg_last = msghdr;
762 msqptr->msg_last->msg_next = msghdr;
763 msqptr->msg_last = msghdr;
765 msqptr->msg_last->msg_next = NULL;
767 msqptr->msg_cbytes += msghdr->msg_ts;
769 msqptr->msg_lspid = td->td_proc->p_pid;
770 msqptr->msg_stime = time_second;
772 wakeup((caddr_t)msqptr);
775 lwkt_reltoken(&msg_token);
777 uap->sysmsg_result = 0;
785 sys_msgrcv(struct msgrcv_args *uap)
787 struct thread *td = curthread;
788 int msqid = uap->msqid;
789 void *user_msgp = uap->msgp;
790 size_t msgsz = uap->msgsz;
791 long msgtyp = uap->msgtyp;
792 int msgflg = uap->msgflg;
794 struct msqid_ds *msqptr;
800 kprintf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp,
801 msgsz, msgtyp, msgflg);
804 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
807 lwkt_gettoken(&msg_token);
808 msqid = IPCID_TO_IX(msqid);
810 if (msqid < 0 || msqid >= msginfo.msgmni) {
812 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
819 msqptr = &msqids[msqid];
820 if (msqptr->msg_qbytes == 0) {
822 kprintf("no such message queue id\n");
827 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
829 kprintf("wrong sequence number\n");
835 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, IPC_R))) {
837 kprintf("requester doesn't have read access\n");
843 while (msghdr == NULL) {
845 msghdr = msqptr->msg_first;
846 if (msghdr != NULL) {
847 if (msgsz < msghdr->msg_ts &&
848 (msgflg & MSG_NOERROR) == 0) {
850 kprintf("first message on the queue is too big (want %d, got %d)\n",
851 msgsz, msghdr->msg_ts);
856 if (msqptr->msg_first == msqptr->msg_last) {
857 msqptr->msg_first = NULL;
858 msqptr->msg_last = NULL;
860 msqptr->msg_first = msghdr->msg_next;
861 if (msqptr->msg_first == NULL)
862 panic("msg_first/last screwed up #1");
866 struct msg *previous;
870 prev = &(msqptr->msg_first);
871 while ((msghdr = *prev) != NULL) {
873 * Is this message's type an exact match or is
874 * this message's type less than or equal to
875 * the absolute value of a negative msgtyp?
876 * Note that the second half of this test can
877 * NEVER be true if msgtyp is positive since
878 * msg_type is always positive!
881 if (msgtyp == msghdr->msg_type ||
882 msghdr->msg_type <= -msgtyp) {
884 kprintf("found message type %d, requested %d\n",
885 msghdr->msg_type, msgtyp);
887 if (msgsz < msghdr->msg_ts &&
888 (msgflg & MSG_NOERROR) == 0) {
890 kprintf("requested message on the queue is too big (want %d, got %d)\n",
891 msgsz, msghdr->msg_ts);
896 *prev = msghdr->msg_next;
897 if (msghdr == msqptr->msg_last) {
898 if (previous == NULL) {
901 panic("msg_first/last screwed up #2");
909 panic("msg_first/last screwed up #3");
917 prev = &(msghdr->msg_next);
922 * We've either extracted the msghdr for the appropriate
923 * message or there isn't one.
924 * If there is one then bail out of this loop.
931 * Hmph! No message found. Does the user want to wait?
934 if ((msgflg & IPC_NOWAIT) != 0) {
936 kprintf("no appropriate message found (msgtyp=%d)\n",
939 /* The SVID says to return ENOMSG. */
943 /* Unfortunately, BSD doesn't define that code yet! */
950 * Wait for something to happen
954 kprintf("msgrcv: goodnight\n");
956 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
958 kprintf("msgrcv: good morning (eval=%d)\n", eval);
963 kprintf("msgsnd: interrupted system call\n");
970 * Make sure that the msq queue still exists
973 if (msqptr->msg_qbytes == 0 ||
974 msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
976 kprintf("msqid deleted\n");
984 * Return the message to the user.
986 * First, do the bookkeeping (before we risk being interrupted).
989 msqptr->msg_cbytes -= msghdr->msg_ts;
991 msqptr->msg_lrpid = td->td_proc->p_pid;
992 msqptr->msg_rtime = time_second;
995 * Make msgsz the actual amount that we'll be returning.
996 * Note that this effectively truncates the message if it is too long
997 * (since msgsz is never increased).
1001 kprintf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
1004 if (msgsz > msghdr->msg_ts)
1005 msgsz = msghdr->msg_ts;
1008 * Return the type to the user.
1011 eval = copyout((caddr_t)&(msghdr->msg_type), user_msgp,
1012 sizeof(msghdr->msg_type));
1015 kprintf("error (%d) copying out message type\n", eval);
1017 msg_freehdr(msghdr);
1018 wakeup((caddr_t)msqptr);
1021 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
1024 * Return the segments to the user
1027 next = msghdr->msg_spot;
1028 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1031 if (msgsz - len > msginfo.msgssz)
1032 tlen = msginfo.msgssz;
1036 panic("next too low #3");
1037 if (next >= msginfo.msgseg)
1038 panic("next out of range #3");
1039 eval = copyout((caddr_t)&msgpool[next * msginfo.msgssz],
1043 kprintf("error (%d) copying out message segment\n",
1046 msg_freehdr(msghdr);
1047 wakeup((caddr_t)msqptr);
1050 user_msgp = (char *)user_msgp + tlen;
1051 next = msgmaps[next].next;
1055 * Done, return the actual number of bytes copied out.
1058 msg_freehdr(msghdr);
1059 wakeup((caddr_t)msqptr);
1062 lwkt_reltoken(&msg_token);
1064 uap->sysmsg_result = msgsz;
1069 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1071 return (SYSCTL_OUT(req, msqids,
1072 sizeof(struct msqid_ds) * msginfo.msgmni));
1075 TUNABLE_INT("kern.ipc.msgseg", &msginfo.msgseg);
1076 TUNABLE_INT("kern.ipc.msgssz", &msginfo.msgssz);
1077 TUNABLE_INT("kern.ipc.msgmni", &msginfo.msgmni);
1079 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1080 "Max characters in message");
1081 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0,
1082 "Max message queue identifiers");
1083 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0,
1084 "Max characters in message queue");
1085 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0,
1086 "Max SVID messages in system");
1087 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0,
1088 "Power-of-two size of a message segment");
1089 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0,
1090 "Number of message segments");
1091 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1092 NULL, 0, sysctl_msqids, "", "Message queue IDs");