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>
32 #include <sys/sysent.h>
33 #include <sys/sysctl.h>
34 #include <sys/malloc.h>
37 #include <sys/mplock2.h>
39 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
41 static void msginit (void *);
46 static void msg_freehdr (struct msg *msghdr);
48 /* XXX casting to (sy_call_t *) is bogus, as usual. */
49 static sy_call_t *msgcalls[] = {
50 (sy_call_t *)sys_msgctl, (sy_call_t *)sys_msgget,
51 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
55 struct msg *msg_next; /* next msg in the chain */
56 long msg_type; /* type of this message */
57 /* >0 -> type of this message */
58 /* 0 -> free header */
59 u_short msg_ts; /* size of this message */
60 short msg_spot; /* location of start of msg in buffer */
65 #define MSGSSZ 8 /* Each segment must be 2^N long */
68 #define MSGSEG 2048 /* must be less than 32767 */
70 #define MSGMAX (MSGSSZ*MSGSEG)
72 #define MSGMNB 2048 /* max # of bytes in a queue */
82 * Based on the configuration parameters described in an SVR2 (yes, two)
83 * config(1m) man page.
85 * Each message is broken up and stored in segments that are msgssz bytes
86 * long. For efficiency reasons, this should be a power of two. Also,
87 * it doesn't make sense if it is less than 8 or greater than about 256.
88 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
89 * two between 8 and 1024 inclusive (and panic's if it isn't).
91 struct msginfo msginfo = {
92 MSGMAX, /* max chars in a message */
93 MSGMNI, /* # of message queue identifiers */
94 MSGMNB, /* max chars in a queue */
95 MSGTQL, /* max messages in system */
96 MSGSSZ, /* size of a message segment */
97 /* (must be small power of 2 greater than 4) */
98 MSGSEG /* number of message segments */
102 * macros to convert between msqid_ds's and msqid's.
103 * (specific to this implementation)
105 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
106 #define MSQID_IX(id) ((id) & 0xffff)
107 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
110 * The rest of this file is specific to this particular implementation.
114 short next; /* next segment in buffer */
115 /* -1 -> available */
116 /* 0..(MSGSEG-1) -> index of next segment */
119 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
121 static int nfree_msgmaps; /* # of free map entries */
122 static short free_msgmaps; /* head of linked list of free map entries */
123 static struct msg *free_msghdrs;/* list of free msg headers */
124 static char *msgpool; /* MSGMAX byte long msg buffer pool */
125 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
126 static struct msg *msghdrs; /* MSGTQL msg headers */
127 static struct msqid_ds *msqids; /* MSGMNI msqid_ds struct's */
134 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
135 msgpool = kmalloc(msginfo.msgmax, M_MSG, M_WAITOK);
136 msgmaps = kmalloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
137 msghdrs = kmalloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
138 msqids = kmalloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK);
141 * msginfo.msgssz should be a power of two for efficiency reasons.
142 * It is also pretty silly if msginfo.msgssz is less than 8
143 * or greater than about 256 so ...
147 while (i < 1024 && i != msginfo.msgssz)
149 if (i != msginfo.msgssz) {
150 kprintf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
152 panic("msginfo.msgssz not a small power of 2");
155 if (msginfo.msgseg > 32767) {
156 kprintf("msginfo.msgseg=%d\n", msginfo.msgseg);
157 panic("msginfo.msgseg > 32767");
161 panic("msgmaps is NULL");
163 for (i = 0; i < msginfo.msgseg; i++) {
165 msgmaps[i-1].next = i;
166 msgmaps[i].next = -1; /* implies entry is available */
169 nfree_msgmaps = msginfo.msgseg;
172 panic("msghdrs is NULL");
174 for (i = 0; i < msginfo.msgtql; i++) {
175 msghdrs[i].msg_type = 0;
177 msghdrs[i-1].msg_next = &msghdrs[i];
178 msghdrs[i].msg_next = NULL;
180 free_msghdrs = &msghdrs[0];
183 panic("msqids is NULL");
185 for (i = 0; i < msginfo.msgmni; i++) {
186 msqids[i].msg_qbytes = 0; /* implies entry is available */
187 msqids[i].msg_perm.seq = 0; /* reset to a known value */
188 msqids[i].msg_perm.mode = 0;
191 SYSINIT(sysv_msg, SI_SUB_SYSV_MSG, SI_ORDER_FIRST, msginit, NULL)
194 * Entry point for all MSG calls
196 * msgsys_args(int which, int a2, ...) (VARARGS)
201 sys_msgsys(struct msgsys_args *uap)
203 struct thread *td = curthread;
204 unsigned int which = (unsigned int)uap->which;
207 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
210 if (which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
212 bcopy(&uap->a2, &uap->which,
213 sizeof(struct msgsys_args) - offsetof(struct msgsys_args, a2));
215 error = (*msgcalls[which])(uap);
221 msg_freehdr(struct msg *msghdr)
223 while (msghdr->msg_ts > 0) {
225 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
226 panic("msghdr->msg_spot out of range");
227 next = msgmaps[msghdr->msg_spot].next;
228 msgmaps[msghdr->msg_spot].next = free_msgmaps;
229 free_msgmaps = msghdr->msg_spot;
231 msghdr->msg_spot = next;
232 if (msghdr->msg_ts >= msginfo.msgssz)
233 msghdr->msg_ts -= msginfo.msgssz;
237 if (msghdr->msg_spot != -1)
238 panic("msghdr->msg_spot != -1");
239 msghdr->msg_next = free_msghdrs;
240 free_msghdrs = msghdr;
247 sys_msgctl(struct msgctl_args *uap)
249 struct thread *td = curthread;
250 struct proc *p = td->td_proc;
251 int msqid = uap->msqid;
253 struct msqid_ds *user_msqptr = uap->buf;
255 struct msqid_ds msqbuf;
256 struct msqid_ds *msqptr;
259 kprintf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr);
262 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
266 msqid = IPCID_TO_IX(msqid);
268 if (msqid < 0 || msqid >= msginfo.msgmni) {
270 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
277 msqptr = &msqids[msqid];
279 if (msqptr->msg_qbytes == 0) {
281 kprintf("no such msqid\n");
286 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
288 kprintf("wrong sequence number\n");
300 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)) != 0)
302 /* Free the message headers */
303 msghdr = msqptr->msg_first;
304 while (msghdr != NULL) {
305 struct msg *msghdr_tmp;
307 /* Free the segments of each message */
308 msqptr->msg_cbytes -= msghdr->msg_ts;
311 msghdr = msghdr->msg_next;
312 msg_freehdr(msghdr_tmp);
315 if (msqptr->msg_cbytes != 0)
316 panic("msg_cbytes is screwed up");
317 if (msqptr->msg_qnum != 0)
318 panic("msg_qnum is screwed up");
320 msqptr->msg_qbytes = 0; /* Mark it as free */
322 wakeup((caddr_t)msqptr);
328 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)) != 0)
330 if ((eval = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0)
332 if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
333 eval = priv_check(td, PRIV_ROOT);
337 if (msqbuf.msg_qbytes > msginfo.msgmnb) {
339 kprintf("can't increase msg_qbytes beyond %d (truncating)\n",
342 msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
344 if (msqbuf.msg_qbytes == 0) {
346 kprintf("can't reduce msg_qbytes to 0\n");
348 eval = EINVAL; /* non-standard errno! */
351 msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */
352 msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */
353 msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
354 (msqbuf.msg_perm.mode & 0777);
355 msqptr->msg_qbytes = msqbuf.msg_qbytes;
356 msqptr->msg_ctime = time_second;
360 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
362 kprintf("requester doesn't have read access\n");
367 eval = copyout(msqptr, user_msqptr, sizeof(struct msqid_ds));
372 kprintf("invalid command %d\n", cmd);
380 uap->sysmsg_result = rval;
388 sys_msgget(struct msgget_args *uap)
390 struct thread *td = curthread;
393 int msgflg = uap->msgflg;
394 struct ucred *cred = td->td_ucred;
395 struct msqid_ds *msqptr = NULL;
398 kprintf("msgget(0x%x, 0%o)\n", key, msgflg);
400 if (!jail_sysvipc_allowed && cred->cr_prison != NULL)
406 if (key != IPC_PRIVATE) {
407 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
408 msqptr = &msqids[msqid];
409 if (msqptr->msg_qbytes != 0 &&
410 msqptr->msg_perm.key == key)
413 if (msqid < msginfo.msgmni) {
415 kprintf("found public key\n");
417 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
419 kprintf("not exclusive\n");
424 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, msgflg & 0700 ))) {
426 kprintf("requester doesn't have 0%o access\n",
436 kprintf("need to allocate the msqid_ds\n");
438 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
439 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
441 * Look for an unallocated and unlocked msqid_ds.
442 * msqid_ds's can be locked by msgsnd or msgrcv while
443 * they are copying the message in/out. We can't
444 * re-use the entry until they release it.
446 msqptr = &msqids[msqid];
447 if (msqptr->msg_qbytes == 0 &&
448 (msqptr->msg_perm.mode & MSG_LOCKED) == 0)
451 if (msqid == msginfo.msgmni) {
453 kprintf("no more msqid_ds's available\n");
459 kprintf("msqid %d is available\n", msqid);
461 msqptr->msg_perm.key = key;
462 msqptr->msg_perm.cuid = cred->cr_uid;
463 msqptr->msg_perm.uid = cred->cr_uid;
464 msqptr->msg_perm.cgid = cred->cr_gid;
465 msqptr->msg_perm.gid = cred->cr_gid;
466 msqptr->msg_perm.mode = (msgflg & 0777);
467 /* Make sure that the returned msqid is unique */
468 msqptr->msg_perm.seq = (msqptr->msg_perm.seq + 1) & 0x7fff;
469 msqptr->msg_first = NULL;
470 msqptr->msg_last = NULL;
471 msqptr->msg_cbytes = 0;
472 msqptr->msg_qnum = 0;
473 msqptr->msg_qbytes = msginfo.msgmnb;
474 msqptr->msg_lspid = 0;
475 msqptr->msg_lrpid = 0;
476 msqptr->msg_stime = 0;
477 msqptr->msg_rtime = 0;
478 msqptr->msg_ctime = time_second;
481 kprintf("didn't find it and wasn't asked to create it\n");
488 /* Construct the unique msqid */
490 uap->sysmsg_result = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
498 sys_msgsnd(struct msgsnd_args *uap)
500 struct thread *td = curthread;
501 int msqid = uap->msqid;
502 void *user_msgp = uap->msgp;
503 size_t msgsz = uap->msgsz;
504 int msgflg = uap->msgflg;
505 int segs_needed, eval;
506 struct msqid_ds *msqptr;
511 kprintf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz,
515 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
519 msqid = IPCID_TO_IX(msqid);
521 if (msqid < 0 || msqid >= msginfo.msgmni) {
523 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
530 msqptr = &msqids[msqid];
531 if (msqptr->msg_qbytes == 0) {
533 kprintf("no such message queue id\n");
538 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
540 kprintf("wrong sequence number\n");
546 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, IPC_W))) {
548 kprintf("requester doesn't have write access\n");
554 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
556 kprintf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
560 int need_more_resources = 0;
564 * (inside this loop in case msg_qbytes changes while we sleep)
567 if (msgsz > msqptr->msg_qbytes) {
569 kprintf("msgsz > msqptr->msg_qbytes\n");
575 if (msqptr->msg_perm.mode & MSG_LOCKED) {
577 kprintf("msqid is locked\n");
579 need_more_resources = 1;
581 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
583 kprintf("msgsz + msg_cbytes > msg_qbytes\n");
585 need_more_resources = 1;
587 if (segs_needed > nfree_msgmaps) {
589 kprintf("segs_needed > nfree_msgmaps\n");
591 need_more_resources = 1;
593 if (free_msghdrs == NULL) {
595 kprintf("no more msghdrs\n");
597 need_more_resources = 1;
600 if (need_more_resources) {
603 if ((msgflg & IPC_NOWAIT) != 0) {
605 kprintf("need more resources but caller doesn't want to wait\n");
611 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
613 kprintf("we don't own the msqid_ds\n");
617 /* Force later arrivals to wait for our
620 kprintf("we own the msqid_ds\n");
622 msqptr->msg_perm.mode |= MSG_LOCKED;
626 kprintf("goodnight\n");
628 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
630 kprintf("good morning, eval=%d\n", eval);
633 msqptr->msg_perm.mode &= ~MSG_LOCKED;
636 kprintf("msgsnd: interrupted system call\n");
643 * Make sure that the msq queue still exists
646 if (msqptr->msg_qbytes == 0) {
648 kprintf("msqid deleted\n");
656 kprintf("got all the resources that we need\n");
663 * We have the resources that we need.
667 if (msqptr->msg_perm.mode & MSG_LOCKED)
668 panic("msg_perm.mode & MSG_LOCKED");
669 if (segs_needed > nfree_msgmaps)
670 panic("segs_needed > nfree_msgmaps");
671 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
672 panic("msgsz + msg_cbytes > msg_qbytes");
673 if (free_msghdrs == NULL)
674 panic("no more msghdrs");
677 * Re-lock the msqid_ds in case we page-fault when copying in the
681 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
682 panic("msqid_ds is already locked");
683 msqptr->msg_perm.mode |= MSG_LOCKED;
686 * Allocate a message header
689 msghdr = free_msghdrs;
690 free_msghdrs = msghdr->msg_next;
691 msghdr->msg_spot = -1;
692 msghdr->msg_ts = msgsz;
695 * Allocate space for the message
698 while (segs_needed > 0) {
699 if (nfree_msgmaps <= 0)
700 panic("not enough msgmaps");
701 if (free_msgmaps == -1)
702 panic("nil free_msgmaps");
705 panic("next too low #1");
706 if (next >= msginfo.msgseg)
707 panic("next out of range #1");
709 kprintf("allocating segment %d to message\n", next);
711 free_msgmaps = msgmaps[next].next;
713 msgmaps[next].next = msghdr->msg_spot;
714 msghdr->msg_spot = next;
719 * Copy in the message type
722 if ((eval = copyin(user_msgp, &msghdr->msg_type,
723 sizeof(msghdr->msg_type))) != 0) {
725 kprintf("error %d copying the message type\n", eval);
728 msqptr->msg_perm.mode &= ~MSG_LOCKED;
729 wakeup((caddr_t)msqptr);
732 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
735 * Validate the message type
738 if (msghdr->msg_type < 1) {
740 msqptr->msg_perm.mode &= ~MSG_LOCKED;
741 wakeup((caddr_t)msqptr);
743 kprintf("mtype (%d) < 1\n", msghdr->msg_type);
750 * Copy in the message body
753 next = msghdr->msg_spot;
756 if (msgsz > msginfo.msgssz)
757 tlen = msginfo.msgssz;
761 panic("next too low #2");
762 if (next >= msginfo.msgseg)
763 panic("next out of range #2");
764 if ((eval = copyin(user_msgp, &msgpool[next * msginfo.msgssz],
767 kprintf("error %d copying in message segment\n", eval);
770 msqptr->msg_perm.mode &= ~MSG_LOCKED;
771 wakeup((caddr_t)msqptr);
775 user_msgp = (char *)user_msgp + tlen;
776 next = msgmaps[next].next;
779 panic("didn't use all the msg segments");
782 * We've got the message. Unlock the msqid_ds.
785 msqptr->msg_perm.mode &= ~MSG_LOCKED;
788 * Make sure that the msqid_ds is still allocated.
791 if (msqptr->msg_qbytes == 0) {
793 wakeup((caddr_t)msqptr);
799 * Put the message into the queue
802 if (msqptr->msg_first == NULL) {
803 msqptr->msg_first = msghdr;
804 msqptr->msg_last = msghdr;
806 msqptr->msg_last->msg_next = msghdr;
807 msqptr->msg_last = msghdr;
809 msqptr->msg_last->msg_next = NULL;
811 msqptr->msg_cbytes += msghdr->msg_ts;
813 msqptr->msg_lspid = td->td_proc->p_pid;
814 msqptr->msg_stime = time_second;
816 wakeup((caddr_t)msqptr);
821 uap->sysmsg_result = 0;
829 sys_msgrcv(struct msgrcv_args *uap)
831 struct thread *td = curthread;
832 int msqid = uap->msqid;
833 void *user_msgp = uap->msgp;
834 size_t msgsz = uap->msgsz;
835 long msgtyp = uap->msgtyp;
836 int msgflg = uap->msgflg;
838 struct msqid_ds *msqptr;
844 kprintf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp,
845 msgsz, msgtyp, msgflg);
848 if (!jail_sysvipc_allowed && td->td_ucred->cr_prison != NULL)
852 msqid = IPCID_TO_IX(msqid);
854 if (msqid < 0 || msqid >= msginfo.msgmni) {
856 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
863 msqptr = &msqids[msqid];
864 if (msqptr->msg_qbytes == 0) {
866 kprintf("no such message queue id\n");
871 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
873 kprintf("wrong sequence number\n");
879 if ((eval = ipcperm(td->td_proc, &msqptr->msg_perm, IPC_R))) {
881 kprintf("requester doesn't have read access\n");
887 while (msghdr == NULL) {
889 msghdr = msqptr->msg_first;
890 if (msghdr != NULL) {
891 if (msgsz < msghdr->msg_ts &&
892 (msgflg & MSG_NOERROR) == 0) {
894 kprintf("first message on the queue is too big (want %d, got %d)\n",
895 msgsz, msghdr->msg_ts);
900 if (msqptr->msg_first == msqptr->msg_last) {
901 msqptr->msg_first = NULL;
902 msqptr->msg_last = NULL;
904 msqptr->msg_first = msghdr->msg_next;
905 if (msqptr->msg_first == NULL)
906 panic("msg_first/last screwed up #1");
910 struct msg *previous;
914 prev = &(msqptr->msg_first);
915 while ((msghdr = *prev) != NULL) {
917 * Is this message's type an exact match or is
918 * this message's type less than or equal to
919 * the absolute value of a negative msgtyp?
920 * Note that the second half of this test can
921 * NEVER be true if msgtyp is positive since
922 * msg_type is always positive!
925 if (msgtyp == msghdr->msg_type ||
926 msghdr->msg_type <= -msgtyp) {
928 kprintf("found message type %d, requested %d\n",
929 msghdr->msg_type, msgtyp);
931 if (msgsz < msghdr->msg_ts &&
932 (msgflg & MSG_NOERROR) == 0) {
934 kprintf("requested message on the queue is too big (want %d, got %d)\n",
935 msgsz, msghdr->msg_ts);
940 *prev = msghdr->msg_next;
941 if (msghdr == msqptr->msg_last) {
942 if (previous == NULL) {
945 panic("msg_first/last screwed up #2");
953 panic("msg_first/last screwed up #3");
961 prev = &(msghdr->msg_next);
966 * We've either extracted the msghdr for the appropriate
967 * message or there isn't one.
968 * If there is one then bail out of this loop.
975 * Hmph! No message found. Does the user want to wait?
978 if ((msgflg & IPC_NOWAIT) != 0) {
980 kprintf("no appropriate message found (msgtyp=%d)\n",
983 /* The SVID says to return ENOMSG. */
987 /* Unfortunately, BSD doesn't define that code yet! */
994 * Wait for something to happen
998 kprintf("msgrcv: goodnight\n");
1000 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
1002 kprintf("msgrcv: good morning (eval=%d)\n", eval);
1007 kprintf("msgsnd: interrupted system call\n");
1014 * Make sure that the msq queue still exists
1017 if (msqptr->msg_qbytes == 0 ||
1018 msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
1020 kprintf("msqid deleted\n");
1028 * Return the message to the user.
1030 * First, do the bookkeeping (before we risk being interrupted).
1033 msqptr->msg_cbytes -= msghdr->msg_ts;
1035 msqptr->msg_lrpid = td->td_proc->p_pid;
1036 msqptr->msg_rtime = time_second;
1039 * Make msgsz the actual amount that we'll be returning.
1040 * Note that this effectively truncates the message if it is too long
1041 * (since msgsz is never increased).
1045 kprintf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
1048 if (msgsz > msghdr->msg_ts)
1049 msgsz = msghdr->msg_ts;
1052 * Return the type to the user.
1055 eval = copyout((caddr_t)&(msghdr->msg_type), user_msgp,
1056 sizeof(msghdr->msg_type));
1059 kprintf("error (%d) copying out message type\n", eval);
1061 msg_freehdr(msghdr);
1062 wakeup((caddr_t)msqptr);
1065 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
1068 * Return the segments to the user
1071 next = msghdr->msg_spot;
1072 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1075 if (msgsz - len > msginfo.msgssz)
1076 tlen = msginfo.msgssz;
1080 panic("next too low #3");
1081 if (next >= msginfo.msgseg)
1082 panic("next out of range #3");
1083 eval = copyout((caddr_t)&msgpool[next * msginfo.msgssz],
1087 kprintf("error (%d) copying out message segment\n",
1090 msg_freehdr(msghdr);
1091 wakeup((caddr_t)msqptr);
1094 user_msgp = (char *)user_msgp + tlen;
1095 next = msgmaps[next].next;
1099 * Done, return the actual number of bytes copied out.
1102 msg_freehdr(msghdr);
1103 wakeup((caddr_t)msqptr);
1108 uap->sysmsg_result = msgsz;
1113 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1116 return (SYSCTL_OUT(req, msqids,
1117 sizeof(struct msqid_ds) * msginfo.msgmni));
1120 TUNABLE_INT("kern.ipc.msgseg", &msginfo.msgseg);
1121 TUNABLE_INT("kern.ipc.msgssz", &msginfo.msgssz);
1122 TUNABLE_INT("kern.ipc.msgmni", &msginfo.msgmni);
1124 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, "");
1125 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0, "");
1126 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0, "");
1127 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0, "");
1128 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0, "");
1129 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0, "");
1130 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1131 NULL, 0, sysctl_msqids, "", "Message queue IDs");