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 #include <sys/mplock2.h>
38 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
40 static void msginit (void *);
45 static void msg_freehdr (struct msg *msghdr);
47 /* XXX casting to (sy_call_t *) is bogus, as usual. */
48 static sy_call_t *msgcalls[] = {
49 (sy_call_t *)sys_msgctl, (sy_call_t *)sys_msgget,
50 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
54 struct msg *msg_next; /* next msg in the chain */
55 long msg_type; /* type of this message */
56 /* >0 -> type of this message */
57 /* 0 -> free header */
58 u_short msg_ts; /* size of this message */
59 short msg_spot; /* location of start of msg in buffer */
64 #define MSGSSZ 8 /* Each segment must be 2^N long */
67 #define MSGSEG 2048 /* must be less than 32767 */
69 #define MSGMAX (MSGSSZ*MSGSEG)
71 #define MSGMNB 2048 /* max # of bytes in a queue */
81 * Based on the configuration parameters described in an SVR2 (yes, two)
82 * config(1m) man page.
84 * Each message is broken up and stored in segments that are msgssz bytes
85 * long. For efficiency reasons, this should be a power of two. Also,
86 * it doesn't make sense if it is less than 8 or greater than about 256.
87 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
88 * two between 8 and 1024 inclusive (and panic's if it isn't).
90 struct msginfo msginfo = {
91 MSGMAX, /* max chars in a message */
92 MSGMNI, /* # of message queue identifiers */
93 MSGMNB, /* max chars in a queue */
94 MSGTQL, /* max messages in system */
95 MSGSSZ, /* size of a message segment */
96 /* (must be small power of 2 greater than 4) */
97 MSGSEG /* number of message segments */
101 * macros to convert between msqid_ds's and msqid's.
102 * (specific to this implementation)
104 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
105 #define MSQID_IX(id) ((id) & 0xffff)
106 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
109 * The rest of this file is specific to this particular implementation.
113 short next; /* next segment in buffer */
114 /* -1 -> available */
115 /* 0..(MSGSEG-1) -> index of next segment */
118 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
120 static int nfree_msgmaps; /* # of free map entries */
121 static short free_msgmaps; /* head of linked list of free map entries */
122 static struct msg *free_msghdrs;/* list of free msg headers */
123 static char *msgpool; /* MSGMAX byte long msg buffer pool */
124 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
125 static struct msg *msghdrs; /* MSGTQL msg headers */
126 static struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
133 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
134 msgpool = kmalloc(msginfo.msgmax, M_MSG, M_WAITOK);
135 msgmaps = kmalloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
136 msghdrs = kmalloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
137 msqids = kmalloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK);
140 * msginfo.msgssz should be a power of two for efficiency reasons.
141 * It is also pretty silly if msginfo.msgssz is less than 8
142 * or greater than about 256 so ...
146 while (i < 1024 && i != msginfo.msgssz)
148 if (i != msginfo.msgssz) {
149 kprintf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
151 panic("msginfo.msgssz not a small power of 2");
154 if (msginfo.msgseg > 32767) {
155 kprintf("msginfo.msgseg=%d\n", msginfo.msgseg);
156 panic("msginfo.msgseg > 32767");
160 panic("msgmaps is NULL");
162 for (i = 0; i < msginfo.msgseg; i++) {
164 msgmaps[i-1].next = i;
165 msgmaps[i].next = -1; /* implies entry is available */
168 nfree_msgmaps = msginfo.msgseg;
171 panic("msghdrs is NULL");
173 for (i = 0; i < msginfo.msgtql; i++) {
174 msghdrs[i].msg_type = 0;
176 msghdrs[i-1].msg_next = &msghdrs[i];
177 msghdrs[i].msg_next = NULL;
179 free_msghdrs = &msghdrs[0];
182 panic("msqids is NULL");
184 for (i = 0; i < msginfo.msgmni; i++) {
185 msqids[i].msg_qbytes = 0; /* implies entry is available */
186 msqids[i].msg_perm.seq = 0; /* reset to a known value */
187 msqids[i].msg_perm.mode = 0;
190 SYSINIT(sysv_msg, SI_SUB_SYSV_MSG, SI_ORDER_FIRST, msginit, NULL)
193 * Entry point for all MSG calls
195 * msgsys_args(int which, int a2, ...) (VARARGS)
200 sys_msgsys(struct msgsys_args *uap)
202 struct thread *td = curthread;
203 unsigned int which = (unsigned int)uap->which;
206 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
209 if (which >= NELEM(msgcalls))
211 bcopy(&uap->a2, &uap->which,
212 sizeof(struct msgsys_args) - offsetof(struct msgsys_args, a2));
214 error = (*msgcalls[which])(uap);
220 msg_freehdr(struct msg *msghdr)
222 while (msghdr->msg_ts > 0) {
224 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
225 panic("msghdr->msg_spot out of range");
226 next = msgmaps[msghdr->msg_spot].next;
227 msgmaps[msghdr->msg_spot].next = free_msgmaps;
228 free_msgmaps = msghdr->msg_spot;
230 msghdr->msg_spot = next;
231 if (msghdr->msg_ts >= msginfo.msgssz)
232 msghdr->msg_ts -= msginfo.msgssz;
236 if (msghdr->msg_spot != -1)
237 panic("msghdr->msg_spot != -1");
238 msghdr->msg_next = free_msghdrs;
239 free_msghdrs = msghdr;
246 sys_msgctl(struct msgctl_args *uap)
248 struct thread *td = curthread;
249 struct proc *p = td->td_proc;
250 int msqid = uap->msqid;
252 struct msqid_ds *user_msqptr = uap->buf;
254 struct msqid_ds msqbuf;
255 struct msqid_ds *msqptr;
258 kprintf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr);
261 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
265 msqid = IPCID_TO_IX(msqid);
267 if (msqid < 0 || msqid >= msginfo.msgmni) {
269 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
276 msqptr = &msqids[msqid];
278 if (msqptr->msg_qbytes == 0) {
280 kprintf("no such msqid\n");
285 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
287 kprintf("wrong sequence number\n");
299 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)) != 0)
301 /* Free the message headers */
302 msghdr = msqptr->msg_first;
303 while (msghdr != NULL) {
304 struct msg *msghdr_tmp;
306 /* Free the segments of each message */
307 msqptr->msg_cbytes -= msghdr->msg_ts;
310 msghdr = msghdr->msg_next;
311 msg_freehdr(msghdr_tmp);
314 if (msqptr->msg_cbytes != 0)
315 panic("msg_cbytes is screwed up");
316 if (msqptr->msg_qnum != 0)
317 panic("msg_qnum is screwed up");
319 msqptr->msg_qbytes = 0; /* Mark it as free */
321 wakeup((caddr_t)msqptr);
327 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)) != 0)
329 if ((eval = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0)
331 if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
332 eval = priv_check(td, PRIV_ROOT);
336 if (msqbuf.msg_qbytes > msginfo.msgmnb) {
338 kprintf("can't increase msg_qbytes beyond %d (truncating)\n",
341 msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
343 if (msqbuf.msg_qbytes == 0) {
345 kprintf("can't reduce msg_qbytes to 0\n");
347 eval = EINVAL; /* non-standard errno! */
350 msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */
351 msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */
352 msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
353 (msqbuf.msg_perm.mode & 0777);
354 msqptr->msg_qbytes = msqbuf.msg_qbytes;
355 msqptr->msg_ctime = time_second;
359 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
361 kprintf("requester doesn't have read access\n");
366 eval = copyout(msqptr, user_msqptr, sizeof(struct msqid_ds));
371 kprintf("invalid command %d\n", cmd);
379 uap->sysmsg_result = rval;
387 sys_msgget(struct msgget_args *uap)
389 struct thread *td = curthread;
392 int msgflg = uap->msgflg;
393 struct ucred *cred = td->td_ucred;
394 struct msqid_ds *msqptr = NULL;
397 kprintf("msgget(0x%x, 0%o)\n", key, msgflg);
399 if (!jail_sysvipc_allowed && cred->cr_prison != NULL)
405 if (key != IPC_PRIVATE) {
406 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
407 msqptr = &msqids[msqid];
408 if (msqptr->msg_qbytes != 0 &&
409 msqptr->msg_perm.key == key)
412 if (msqid < msginfo.msgmni) {
414 kprintf("found public key\n");
416 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
418 kprintf("not exclusive\n");
423 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, msgflg & 0700 ))) {
425 kprintf("requester doesn't have 0%o access\n",
435 kprintf("need to allocate the msqid_ds\n");
437 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
438 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
440 * Look for an unallocated and unlocked msqid_ds.
441 * msqid_ds's can be locked by msgsnd or msgrcv while
442 * they are copying the message in/out. We can't
443 * re-use the entry until they release it.
445 msqptr = &msqids[msqid];
446 if (msqptr->msg_qbytes == 0 &&
447 (msqptr->msg_perm.mode & MSG_LOCKED) == 0)
450 if (msqid == msginfo.msgmni) {
452 kprintf("no more msqid_ds's available\n");
458 kprintf("msqid %d is available\n", msqid);
460 msqptr->msg_perm.key = key;
461 msqptr->msg_perm.cuid = cred->cr_uid;
462 msqptr->msg_perm.uid = cred->cr_uid;
463 msqptr->msg_perm.cgid = cred->cr_gid;
464 msqptr->msg_perm.gid = cred->cr_gid;
465 msqptr->msg_perm.mode = (msgflg & 0777);
466 /* Make sure that the returned msqid is unique */
467 msqptr->msg_perm.seq = (msqptr->msg_perm.seq + 1) & 0x7fff;
468 msqptr->msg_first = NULL;
469 msqptr->msg_last = NULL;
470 msqptr->msg_cbytes = 0;
471 msqptr->msg_qnum = 0;
472 msqptr->msg_qbytes = msginfo.msgmnb;
473 msqptr->msg_lspid = 0;
474 msqptr->msg_lrpid = 0;
475 msqptr->msg_stime = 0;
476 msqptr->msg_rtime = 0;
477 msqptr->msg_ctime = time_second;
480 kprintf("didn't find it and wasn't asked to create it\n");
487 /* Construct the unique msqid */
489 uap->sysmsg_result = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
497 sys_msgsnd(struct msgsnd_args *uap)
499 struct thread *td = curthread;
500 int msqid = uap->msqid;
501 void *user_msgp = uap->msgp;
502 size_t msgsz = uap->msgsz;
503 int msgflg = uap->msgflg;
504 int segs_needed, eval;
505 struct msqid_ds *msqptr;
510 kprintf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz,
514 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
518 msqid = IPCID_TO_IX(msqid);
520 if (msqid < 0 || msqid >= msginfo.msgmni) {
522 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
529 msqptr = &msqids[msqid];
530 if (msqptr->msg_qbytes == 0) {
532 kprintf("no such message queue id\n");
537 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
539 kprintf("wrong sequence number\n");
545 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, IPC_W))) {
547 kprintf("requester doesn't have write access\n");
553 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
555 kprintf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
559 int need_more_resources = 0;
563 * (inside this loop in case msg_qbytes changes while we sleep)
566 if (msgsz > msqptr->msg_qbytes) {
568 kprintf("msgsz > msqptr->msg_qbytes\n");
574 if (msqptr->msg_perm.mode & MSG_LOCKED) {
576 kprintf("msqid is locked\n");
578 need_more_resources = 1;
580 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
582 kprintf("msgsz + msg_cbytes > msg_qbytes\n");
584 need_more_resources = 1;
586 if (segs_needed > nfree_msgmaps) {
588 kprintf("segs_needed > nfree_msgmaps\n");
590 need_more_resources = 1;
592 if (free_msghdrs == NULL) {
594 kprintf("no more msghdrs\n");
596 need_more_resources = 1;
599 if (need_more_resources) {
602 if ((msgflg & IPC_NOWAIT) != 0) {
604 kprintf("need more resources but caller doesn't want to wait\n");
610 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
612 kprintf("we don't own the msqid_ds\n");
616 /* Force later arrivals to wait for our
619 kprintf("we own the msqid_ds\n");
621 msqptr->msg_perm.mode |= MSG_LOCKED;
625 kprintf("goodnight\n");
627 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
629 kprintf("good morning, eval=%d\n", eval);
632 msqptr->msg_perm.mode &= ~MSG_LOCKED;
635 kprintf("msgsnd: interrupted system call\n");
642 * Make sure that the msq queue still exists
645 if (msqptr->msg_qbytes == 0) {
647 kprintf("msqid deleted\n");
655 kprintf("got all the resources that we need\n");
662 * We have the resources that we need.
666 if (msqptr->msg_perm.mode & MSG_LOCKED)
667 panic("msg_perm.mode & MSG_LOCKED");
668 if (segs_needed > nfree_msgmaps)
669 panic("segs_needed > nfree_msgmaps");
670 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
671 panic("msgsz + msg_cbytes > msg_qbytes");
672 if (free_msghdrs == NULL)
673 panic("no more msghdrs");
676 * Re-lock the msqid_ds in case we page-fault when copying in the
680 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
681 panic("msqid_ds is already locked");
682 msqptr->msg_perm.mode |= MSG_LOCKED;
685 * Allocate a message header
688 msghdr = free_msghdrs;
689 free_msghdrs = msghdr->msg_next;
690 msghdr->msg_spot = -1;
691 msghdr->msg_ts = msgsz;
694 * Allocate space for the message
697 while (segs_needed > 0) {
698 if (nfree_msgmaps <= 0)
699 panic("not enough msgmaps");
700 if (free_msgmaps == -1)
701 panic("nil free_msgmaps");
704 panic("next too low #1");
705 if (next >= msginfo.msgseg)
706 panic("next out of range #1");
708 kprintf("allocating segment %d to message\n", next);
710 free_msgmaps = msgmaps[next].next;
712 msgmaps[next].next = msghdr->msg_spot;
713 msghdr->msg_spot = next;
718 * Copy in the message type
721 if ((eval = copyin(user_msgp, &msghdr->msg_type,
722 sizeof(msghdr->msg_type))) != 0) {
724 kprintf("error %d copying the message type\n", eval);
727 msqptr->msg_perm.mode &= ~MSG_LOCKED;
728 wakeup((caddr_t)msqptr);
731 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
734 * Validate the message type
737 if (msghdr->msg_type < 1) {
739 msqptr->msg_perm.mode &= ~MSG_LOCKED;
740 wakeup((caddr_t)msqptr);
742 kprintf("mtype (%d) < 1\n", msghdr->msg_type);
749 * Copy in the message body
752 next = msghdr->msg_spot;
755 if (msgsz > msginfo.msgssz)
756 tlen = msginfo.msgssz;
760 panic("next too low #2");
761 if (next >= msginfo.msgseg)
762 panic("next out of range #2");
763 if ((eval = copyin(user_msgp, &msgpool[next * msginfo.msgssz],
766 kprintf("error %d copying in message segment\n", eval);
769 msqptr->msg_perm.mode &= ~MSG_LOCKED;
770 wakeup((caddr_t)msqptr);
774 user_msgp = (char *)user_msgp + tlen;
775 next = msgmaps[next].next;
778 panic("didn't use all the msg segments");
781 * We've got the message. Unlock the msqid_ds.
784 msqptr->msg_perm.mode &= ~MSG_LOCKED;
787 * Make sure that the msqid_ds is still allocated.
790 if (msqptr->msg_qbytes == 0) {
792 wakeup((caddr_t)msqptr);
798 * Put the message into the queue
801 if (msqptr->msg_first == NULL) {
802 msqptr->msg_first = msghdr;
803 msqptr->msg_last = msghdr;
805 msqptr->msg_last->msg_next = msghdr;
806 msqptr->msg_last = msghdr;
808 msqptr->msg_last->msg_next = NULL;
810 msqptr->msg_cbytes += msghdr->msg_ts;
812 msqptr->msg_lspid = td->td_proc->p_pid;
813 msqptr->msg_stime = time_second;
815 wakeup((caddr_t)msqptr);
820 uap->sysmsg_result = 0;
828 sys_msgrcv(struct msgrcv_args *uap)
830 struct thread *td = curthread;
831 int msqid = uap->msqid;
832 void *user_msgp = uap->msgp;
833 size_t msgsz = uap->msgsz;
834 long msgtyp = uap->msgtyp;
835 int msgflg = uap->msgflg;
837 struct msqid_ds *msqptr;
843 kprintf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp,
844 msgsz, msgtyp, msgflg);
847 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
851 msqid = IPCID_TO_IX(msqid);
853 if (msqid < 0 || msqid >= msginfo.msgmni) {
855 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
862 msqptr = &msqids[msqid];
863 if (msqptr->msg_qbytes == 0) {
865 kprintf("no such message queue id\n");
870 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
872 kprintf("wrong sequence number\n");
878 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, IPC_R))) {
880 kprintf("requester doesn't have read access\n");
886 while (msghdr == NULL) {
888 msghdr = msqptr->msg_first;
889 if (msghdr != NULL) {
890 if (msgsz < msghdr->msg_ts &&
891 (msgflg & MSG_NOERROR) == 0) {
893 kprintf("first message on the queue is too big (want %d, got %d)\n",
894 msgsz, msghdr->msg_ts);
899 if (msqptr->msg_first == msqptr->msg_last) {
900 msqptr->msg_first = NULL;
901 msqptr->msg_last = NULL;
903 msqptr->msg_first = msghdr->msg_next;
904 if (msqptr->msg_first == NULL)
905 panic("msg_first/last screwed up #1");
909 struct msg *previous;
913 prev = &(msqptr->msg_first);
914 while ((msghdr = *prev) != NULL) {
916 * Is this message's type an exact match or is
917 * this message's type less than or equal to
918 * the absolute value of a negative msgtyp?
919 * Note that the second half of this test can
920 * NEVER be true if msgtyp is positive since
921 * msg_type is always positive!
924 if (msgtyp == msghdr->msg_type ||
925 msghdr->msg_type <= -msgtyp) {
927 kprintf("found message type %d, requested %d\n",
928 msghdr->msg_type, msgtyp);
930 if (msgsz < msghdr->msg_ts &&
931 (msgflg & MSG_NOERROR) == 0) {
933 kprintf("requested message on the queue is too big (want %d, got %d)\n",
934 msgsz, msghdr->msg_ts);
939 *prev = msghdr->msg_next;
940 if (msghdr == msqptr->msg_last) {
941 if (previous == NULL) {
944 panic("msg_first/last screwed up #2");
952 panic("msg_first/last screwed up #3");
960 prev = &(msghdr->msg_next);
965 * We've either extracted the msghdr for the appropriate
966 * message or there isn't one.
967 * If there is one then bail out of this loop.
974 * Hmph! No message found. Does the user want to wait?
977 if ((msgflg & IPC_NOWAIT) != 0) {
979 kprintf("no appropriate message found (msgtyp=%d)\n",
982 /* The SVID says to return ENOMSG. */
986 /* Unfortunately, BSD doesn't define that code yet! */
993 * Wait for something to happen
997 kprintf("msgrcv: goodnight\n");
999 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
1001 kprintf("msgrcv: good morning (eval=%d)\n", eval);
1006 kprintf("msgsnd: interrupted system call\n");
1013 * Make sure that the msq queue still exists
1016 if (msqptr->msg_qbytes == 0 ||
1017 msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
1019 kprintf("msqid deleted\n");
1027 * Return the message to the user.
1029 * First, do the bookkeeping (before we risk being interrupted).
1032 msqptr->msg_cbytes -= msghdr->msg_ts;
1034 msqptr->msg_lrpid = td->td_proc->p_pid;
1035 msqptr->msg_rtime = time_second;
1038 * Make msgsz the actual amount that we'll be returning.
1039 * Note that this effectively truncates the message if it is too long
1040 * (since msgsz is never increased).
1044 kprintf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
1047 if (msgsz > msghdr->msg_ts)
1048 msgsz = msghdr->msg_ts;
1051 * Return the type to the user.
1054 eval = copyout((caddr_t)&(msghdr->msg_type), user_msgp,
1055 sizeof(msghdr->msg_type));
1058 kprintf("error (%d) copying out message type\n", eval);
1060 msg_freehdr(msghdr);
1061 wakeup((caddr_t)msqptr);
1064 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
1067 * Return the segments to the user
1070 next = msghdr->msg_spot;
1071 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1074 if (msgsz - len > msginfo.msgssz)
1075 tlen = msginfo.msgssz;
1079 panic("next too low #3");
1080 if (next >= msginfo.msgseg)
1081 panic("next out of range #3");
1082 eval = copyout((caddr_t)&msgpool[next * msginfo.msgssz],
1086 kprintf("error (%d) copying out message segment\n",
1089 msg_freehdr(msghdr);
1090 wakeup((caddr_t)msqptr);
1093 user_msgp = (char *)user_msgp + tlen;
1094 next = msgmaps[next].next;
1098 * Done, return the actual number of bytes copied out.
1101 msg_freehdr(msghdr);
1102 wakeup((caddr_t)msqptr);
1107 uap->sysmsg_result = msgsz;
1112 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1115 return (SYSCTL_OUT(req, msqids,
1116 sizeof(struct msqid_ds) * msginfo.msgmni));
1119 TUNABLE_INT("kern.ipc.msgseg", &msginfo.msgseg);
1120 TUNABLE_INT("kern.ipc.msgssz", &msginfo.msgssz);
1121 TUNABLE_INT("kern.ipc.msgmni", &msginfo.msgmni);
1123 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1124 "Max characters in message");
1125 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0,
1126 "Max message queue identifiers");
1127 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0,
1128 "Max characters in message queue");
1129 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0,
1130 "Max SVID messages in system");
1131 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0,
1132 "Power-of-two size of a message segment");
1133 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0,
1134 "Number of message segments");
1135 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1136 NULL, 0, sysctl_msqids, "", "Message queue IDs");