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 1.17 2006/12/23 23:47:54 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);
134 panic("msgpool is NULL");
135 msgmaps = kmalloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
137 panic("msgmaps is NULL");
138 msghdrs = kmalloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
140 panic("msghdrs is NULL");
141 msqids = kmalloc(sizeof(struct msqid_ds) * msginfo.msgmni, M_MSG, M_WAITOK);
143 panic("msqids is NULL");
146 * msginfo.msgssz should be a power of two for efficiency reasons.
147 * It is also pretty silly if msginfo.msgssz is less than 8
148 * or greater than about 256 so ...
152 while (i < 1024 && i != msginfo.msgssz)
154 if (i != msginfo.msgssz) {
155 kprintf("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
157 panic("msginfo.msgssz not a small power of 2");
160 if (msginfo.msgseg > 32767) {
161 kprintf("msginfo.msgseg=%d\n", msginfo.msgseg);
162 panic("msginfo.msgseg > 32767");
166 panic("msgmaps is NULL");
168 for (i = 0; i < msginfo.msgseg; i++) {
170 msgmaps[i-1].next = i;
171 msgmaps[i].next = -1; /* implies entry is available */
174 nfree_msgmaps = msginfo.msgseg;
177 panic("msghdrs is NULL");
179 for (i = 0; i < msginfo.msgtql; i++) {
180 msghdrs[i].msg_type = 0;
182 msghdrs[i-1].msg_next = &msghdrs[i];
183 msghdrs[i].msg_next = NULL;
185 free_msghdrs = &msghdrs[0];
188 panic("msqids is NULL");
190 for (i = 0; i < msginfo.msgmni; i++) {
191 msqids[i].msg_qbytes = 0; /* implies entry is available */
192 msqids[i].msg_perm.seq = 0; /* reset to a known value */
193 msqids[i].msg_perm.mode = 0;
196 SYSINIT(sysv_msg, SI_SUB_SYSV_MSG, SI_ORDER_FIRST, msginit, NULL)
199 * Entry point for all MSG calls
201 * msgsys_args(int which, int a2, ...) (VARARGS)
204 sys_msgsys(struct msgsys_args *uap)
206 struct proc *p = curproc;
207 unsigned int which = (unsigned int)uap->which;
209 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
212 if (which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
214 bcopy(&uap->a2, &uap->which,
215 sizeof(struct msgsys_args) - offsetof(struct msgsys_args, a2));
216 return ((*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;
243 sys_msgctl(struct msgctl_args *uap)
245 struct thread *td = curthread;
246 struct proc *p = td->td_proc;
247 int msqid = uap->msqid;
249 struct msqid_ds *user_msqptr = uap->buf;
251 struct msqid_ds msqbuf;
252 struct msqid_ds *msqptr;
255 kprintf("call to msgctl(%d, %d, 0x%x)\n", msqid, cmd, user_msqptr);
258 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
261 msqid = IPCID_TO_IX(msqid);
263 if (msqid < 0 || msqid >= msginfo.msgmni) {
265 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
271 msqptr = &msqids[msqid];
273 if (msqptr->msg_qbytes == 0) {
275 kprintf("no such msqid\n");
279 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
281 kprintf("wrong sequence number\n");
294 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)))
296 /* Free the message headers */
297 msghdr = msqptr->msg_first;
298 while (msghdr != NULL) {
299 struct msg *msghdr_tmp;
301 /* Free the segments of each message */
302 msqptr->msg_cbytes -= msghdr->msg_ts;
305 msghdr = msghdr->msg_next;
306 msg_freehdr(msghdr_tmp);
309 if (msqptr->msg_cbytes != 0)
310 panic("msg_cbytes is screwed up");
311 if (msqptr->msg_qnum != 0)
312 panic("msg_qnum is screwed up");
314 msqptr->msg_qbytes = 0; /* Mark it as free */
316 wakeup((caddr_t)msqptr);
322 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_M)))
324 if ((eval = copyin(user_msqptr, &msqbuf, sizeof(msqbuf))) != 0)
326 if (msqbuf.msg_qbytes > msqptr->msg_qbytes) {
331 if (msqbuf.msg_qbytes > msginfo.msgmnb) {
333 kprintf("can't increase msg_qbytes beyond %d (truncating)\n",
336 msqbuf.msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
338 if (msqbuf.msg_qbytes == 0) {
340 kprintf("can't reduce msg_qbytes to 0\n");
342 return(EINVAL); /* non-standard errno! */
344 msqptr->msg_perm.uid = msqbuf.msg_perm.uid; /* change the owner */
345 msqptr->msg_perm.gid = msqbuf.msg_perm.gid; /* change the owner */
346 msqptr->msg_perm.mode = (msqptr->msg_perm.mode & ~0777) |
347 (msqbuf.msg_perm.mode & 0777);
348 msqptr->msg_qbytes = msqbuf.msg_qbytes;
349 msqptr->msg_ctime = time_second;
353 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
355 kprintf("requester doesn't have read access\n");
359 eval = copyout((caddr_t)msqptr, user_msqptr,
360 sizeof(struct msqid_ds));
365 kprintf("invalid command %d\n", cmd);
371 uap->sysmsg_result = rval;
376 sys_msgget(struct msgget_args *uap)
378 struct proc *p = curproc;
381 int msgflg = uap->msgflg;
382 struct ucred *cred = p->p_ucred;
383 struct msqid_ds *msqptr = NULL;
386 kprintf("msgget(0x%x, 0%o)\n", key, msgflg);
389 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
392 if (key != IPC_PRIVATE) {
393 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
394 msqptr = &msqids[msqid];
395 if (msqptr->msg_qbytes != 0 &&
396 msqptr->msg_perm.key == key)
399 if (msqid < msginfo.msgmni) {
401 kprintf("found public key\n");
403 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
405 kprintf("not exclusive\n");
409 if ((eval = ipcperm(p, &msqptr->msg_perm, msgflg & 0700 ))) {
411 kprintf("requester doesn't have 0%o access\n",
421 kprintf("need to allocate the msqid_ds\n");
423 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
424 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
426 * Look for an unallocated and unlocked msqid_ds.
427 * msqid_ds's can be locked by msgsnd or msgrcv while
428 * they are copying the message in/out. We can't
429 * re-use the entry until they release it.
431 msqptr = &msqids[msqid];
432 if (msqptr->msg_qbytes == 0 &&
433 (msqptr->msg_perm.mode & MSG_LOCKED) == 0)
436 if (msqid == msginfo.msgmni) {
438 kprintf("no more msqid_ds's available\n");
443 kprintf("msqid %d is available\n", msqid);
445 msqptr->msg_perm.key = key;
446 msqptr->msg_perm.cuid = cred->cr_uid;
447 msqptr->msg_perm.uid = cred->cr_uid;
448 msqptr->msg_perm.cgid = cred->cr_gid;
449 msqptr->msg_perm.gid = cred->cr_gid;
450 msqptr->msg_perm.mode = (msgflg & 0777);
451 /* Make sure that the returned msqid is unique */
452 msqptr->msg_perm.seq = (msqptr->msg_perm.seq + 1) & 0x7fff;
453 msqptr->msg_first = NULL;
454 msqptr->msg_last = NULL;
455 msqptr->msg_cbytes = 0;
456 msqptr->msg_qnum = 0;
457 msqptr->msg_qbytes = msginfo.msgmnb;
458 msqptr->msg_lspid = 0;
459 msqptr->msg_lrpid = 0;
460 msqptr->msg_stime = 0;
461 msqptr->msg_rtime = 0;
462 msqptr->msg_ctime = time_second;
465 kprintf("didn't find it and wasn't asked to create it\n");
471 /* Construct the unique msqid */
472 uap->sysmsg_result = IXSEQ_TO_IPCID(msqid, msqptr->msg_perm);
477 sys_msgsnd(struct msgsnd_args *uap)
479 struct proc *p = curproc;
480 int msqid = uap->msqid;
481 void *user_msgp = uap->msgp;
482 size_t msgsz = uap->msgsz;
483 int msgflg = uap->msgflg;
484 int segs_needed, eval;
485 struct msqid_ds *msqptr;
490 kprintf("call to msgsnd(%d, 0x%x, %d, %d)\n", msqid, user_msgp, msgsz,
494 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
497 msqid = IPCID_TO_IX(msqid);
499 if (msqid < 0 || msqid >= msginfo.msgmni) {
501 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
507 msqptr = &msqids[msqid];
508 if (msqptr->msg_qbytes == 0) {
510 kprintf("no such message queue id\n");
514 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
516 kprintf("wrong sequence number\n");
521 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_W))) {
523 kprintf("requester doesn't have write access\n");
528 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
530 kprintf("msgsz=%d, msgssz=%d, segs_needed=%d\n", msgsz, msginfo.msgssz,
534 int need_more_resources = 0;
538 * (inside this loop in case msg_qbytes changes while we sleep)
541 if (msgsz > msqptr->msg_qbytes) {
543 kprintf("msgsz > msqptr->msg_qbytes\n");
548 if (msqptr->msg_perm.mode & MSG_LOCKED) {
550 kprintf("msqid is locked\n");
552 need_more_resources = 1;
554 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes) {
556 kprintf("msgsz + msg_cbytes > msg_qbytes\n");
558 need_more_resources = 1;
560 if (segs_needed > nfree_msgmaps) {
562 kprintf("segs_needed > nfree_msgmaps\n");
564 need_more_resources = 1;
566 if (free_msghdrs == NULL) {
568 kprintf("no more msghdrs\n");
570 need_more_resources = 1;
573 if (need_more_resources) {
576 if ((msgflg & IPC_NOWAIT) != 0) {
578 kprintf("need more resources but caller doesn't want to wait\n");
583 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0) {
585 kprintf("we don't own the msqid_ds\n");
589 /* Force later arrivals to wait for our
592 kprintf("we own the msqid_ds\n");
594 msqptr->msg_perm.mode |= MSG_LOCKED;
598 kprintf("goodnight\n");
600 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
602 kprintf("good morning, eval=%d\n", eval);
605 msqptr->msg_perm.mode &= ~MSG_LOCKED;
608 kprintf("msgsnd: interrupted system call\n");
614 * Make sure that the msq queue still exists
617 if (msqptr->msg_qbytes == 0) {
619 kprintf("msqid deleted\n");
626 kprintf("got all the resources that we need\n");
633 * We have the resources that we need.
637 if (msqptr->msg_perm.mode & MSG_LOCKED)
638 panic("msg_perm.mode & MSG_LOCKED");
639 if (segs_needed > nfree_msgmaps)
640 panic("segs_needed > nfree_msgmaps");
641 if (msgsz + msqptr->msg_cbytes > msqptr->msg_qbytes)
642 panic("msgsz + msg_cbytes > msg_qbytes");
643 if (free_msghdrs == NULL)
644 panic("no more msghdrs");
647 * Re-lock the msqid_ds in case we page-fault when copying in the
651 if ((msqptr->msg_perm.mode & MSG_LOCKED) != 0)
652 panic("msqid_ds is already locked");
653 msqptr->msg_perm.mode |= MSG_LOCKED;
656 * Allocate a message header
659 msghdr = free_msghdrs;
660 free_msghdrs = msghdr->msg_next;
661 msghdr->msg_spot = -1;
662 msghdr->msg_ts = msgsz;
665 * Allocate space for the message
668 while (segs_needed > 0) {
669 if (nfree_msgmaps <= 0)
670 panic("not enough msgmaps");
671 if (free_msgmaps == -1)
672 panic("nil free_msgmaps");
675 panic("next too low #1");
676 if (next >= msginfo.msgseg)
677 panic("next out of range #1");
679 kprintf("allocating segment %d to message\n", next);
681 free_msgmaps = msgmaps[next].next;
683 msgmaps[next].next = msghdr->msg_spot;
684 msghdr->msg_spot = next;
689 * Copy in the message type
692 if ((eval = copyin(user_msgp, &msghdr->msg_type,
693 sizeof(msghdr->msg_type))) != 0) {
695 kprintf("error %d copying the message type\n", eval);
698 msqptr->msg_perm.mode &= ~MSG_LOCKED;
699 wakeup((caddr_t)msqptr);
702 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
705 * Validate the message type
708 if (msghdr->msg_type < 1) {
710 msqptr->msg_perm.mode &= ~MSG_LOCKED;
711 wakeup((caddr_t)msqptr);
713 kprintf("mtype (%d) < 1\n", msghdr->msg_type);
719 * Copy in the message body
722 next = msghdr->msg_spot;
725 if (msgsz > msginfo.msgssz)
726 tlen = msginfo.msgssz;
730 panic("next too low #2");
731 if (next >= msginfo.msgseg)
732 panic("next out of range #2");
733 if ((eval = copyin(user_msgp, &msgpool[next * msginfo.msgssz],
736 kprintf("error %d copying in message segment\n", eval);
739 msqptr->msg_perm.mode &= ~MSG_LOCKED;
740 wakeup((caddr_t)msqptr);
744 user_msgp = (char *)user_msgp + tlen;
745 next = msgmaps[next].next;
748 panic("didn't use all the msg segments");
751 * We've got the message. Unlock the msqid_ds.
754 msqptr->msg_perm.mode &= ~MSG_LOCKED;
757 * Make sure that the msqid_ds is still allocated.
760 if (msqptr->msg_qbytes == 0) {
762 wakeup((caddr_t)msqptr);
767 * Put the message into the queue
770 if (msqptr->msg_first == NULL) {
771 msqptr->msg_first = msghdr;
772 msqptr->msg_last = msghdr;
774 msqptr->msg_last->msg_next = msghdr;
775 msqptr->msg_last = msghdr;
777 msqptr->msg_last->msg_next = NULL;
779 msqptr->msg_cbytes += msghdr->msg_ts;
781 msqptr->msg_lspid = p->p_pid;
782 msqptr->msg_stime = time_second;
784 wakeup((caddr_t)msqptr);
785 uap->sysmsg_result = 0;
790 sys_msgrcv(struct msgrcv_args *uap)
792 struct proc *p = curproc;
793 int msqid = uap->msqid;
794 void *user_msgp = uap->msgp;
795 size_t msgsz = uap->msgsz;
796 long msgtyp = uap->msgtyp;
797 int msgflg = uap->msgflg;
799 struct msqid_ds *msqptr;
805 kprintf("call to msgrcv(%d, 0x%x, %d, %ld, %d)\n", msqid, user_msgp,
806 msgsz, msgtyp, msgflg);
809 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
812 msqid = IPCID_TO_IX(msqid);
814 if (msqid < 0 || msqid >= msginfo.msgmni) {
816 kprintf("msqid (%d) out of range (0<=msqid<%d)\n", msqid,
822 msqptr = &msqids[msqid];
823 if (msqptr->msg_qbytes == 0) {
825 kprintf("no such message queue id\n");
829 if (msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
831 kprintf("wrong sequence number\n");
836 if ((eval = ipcperm(p, &msqptr->msg_perm, IPC_R))) {
838 kprintf("requester doesn't have read access\n");
844 while (msghdr == NULL) {
846 msghdr = msqptr->msg_first;
847 if (msghdr != NULL) {
848 if (msgsz < msghdr->msg_ts &&
849 (msgflg & MSG_NOERROR) == 0) {
851 kprintf("first message on the queue is too big (want %d, got %d)\n",
852 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);
895 *prev = msghdr->msg_next;
896 if (msghdr == msqptr->msg_last) {
897 if (previous == NULL) {
900 panic("msg_first/last screwed up #2");
908 panic("msg_first/last screwed up #3");
916 prev = &(msghdr->msg_next);
921 * We've either extracted the msghdr for the appropriate
922 * message or there isn't one.
923 * If there is one then bail out of this loop.
930 * Hmph! No message found. Does the user want to wait?
933 if ((msgflg & IPC_NOWAIT) != 0) {
935 kprintf("no appropriate message found (msgtyp=%d)\n",
938 /* The SVID says to return ENOMSG. */
942 /* Unfortunately, BSD doesn't define that code yet! */
948 * Wait for something to happen
952 kprintf("msgrcv: goodnight\n");
954 eval = tsleep((caddr_t)msqptr, PCATCH, "msgwait", 0);
956 kprintf("msgrcv: good morning (eval=%d)\n", eval);
961 kprintf("msgsnd: interrupted system call\n");
967 * Make sure that the msq queue still exists
970 if (msqptr->msg_qbytes == 0 ||
971 msqptr->msg_perm.seq != IPCID_TO_SEQ(uap->msqid)) {
973 kprintf("msqid deleted\n");
980 * Return the message to the user.
982 * First, do the bookkeeping (before we risk being interrupted).
985 msqptr->msg_cbytes -= msghdr->msg_ts;
987 msqptr->msg_lrpid = p->p_pid;
988 msqptr->msg_rtime = time_second;
991 * Make msgsz the actual amount that we'll be returning.
992 * Note that this effectively truncates the message if it is too long
993 * (since msgsz is never increased).
997 kprintf("found a message, msgsz=%d, msg_ts=%d\n", msgsz,
1000 if (msgsz > msghdr->msg_ts)
1001 msgsz = msghdr->msg_ts;
1004 * Return the type to the user.
1007 eval = copyout((caddr_t)&(msghdr->msg_type), user_msgp,
1008 sizeof(msghdr->msg_type));
1011 kprintf("error (%d) copying out message type\n", eval);
1013 msg_freehdr(msghdr);
1014 wakeup((caddr_t)msqptr);
1017 user_msgp = (char *)user_msgp + sizeof(msghdr->msg_type);
1020 * Return the segments to the user
1023 next = msghdr->msg_spot;
1024 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1027 if (msgsz - len > msginfo.msgssz)
1028 tlen = msginfo.msgssz;
1032 panic("next too low #3");
1033 if (next >= msginfo.msgseg)
1034 panic("next out of range #3");
1035 eval = copyout((caddr_t)&msgpool[next * msginfo.msgssz],
1039 kprintf("error (%d) copying out message segment\n",
1042 msg_freehdr(msghdr);
1043 wakeup((caddr_t)msqptr);
1046 user_msgp = (char *)user_msgp + tlen;
1047 next = msgmaps[next].next;
1051 * Done, return the actual number of bytes copied out.
1054 msg_freehdr(msghdr);
1055 wakeup((caddr_t)msqptr);
1056 uap->sysmsg_result = msgsz;
1061 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1064 return (SYSCTL_OUT(req, msqids,
1065 sizeof(struct msqid_ds) * msginfo.msgmni));
1068 TUNABLE_INT("kern.ipc.msgseg", &msginfo.msgseg);
1069 TUNABLE_INT("kern.ipc.msgssz", &msginfo.msgssz);
1070 TUNABLE_INT("kern.ipc.msgmni", &msginfo.msgmni);
1072 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0, "");
1073 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RD, &msginfo.msgmni, 0, "");
1074 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RD, &msginfo.msgmnb, 0, "");
1075 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RD, &msginfo.msgtql, 0, "");
1076 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RD, &msginfo.msgssz, 0, "");
1077 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RD, &msginfo.msgseg, 0, "");
1078 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1079 NULL, 0, sysctl_msqids, "", "Message queue IDs");