2 * Implementation of SVID messages
4 * Author: Daniel Boulet
6 * Copyright 1993 Daniel Boulet and RTMX Inc.
8 * This system call was implemented by Daniel Boulet under contract from RTMX.
10 * Redistribution and use in source forms, with and without modification,
11 * are permitted provided that this entire comment appears intact.
13 * Redistribution in binary form may occur without any restrictions.
14 * Obviously, it would be nice if you gave credit where credit is due
15 * but requiring it would be too onerous.
17 * This software is provided ``AS IS'' without any warranties of any kind.
20 * Copyright (c) 2003-2005 McAfee, Inc.
21 * All rights reserved.
23 * This software was developed for the FreeBSD Project in part by McAfee
24 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
25 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
31 * 1. Redistributions of source code must retain the above copyright
32 * notice, this list of conditions and the following disclaimer.
33 * 2. Redistributions in binary form must reproduce the above copyright
34 * notice, this list of conditions and the following disclaimer in the
35 * documentation and/or other materials provided with the distribution.
37 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
38 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
40 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
41 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
42 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
43 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
45 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
46 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
53 #include "opt_sysvipc.h"
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/sysproto.h>
59 #include <sys/kernel.h>
63 #include <sys/mutex.h>
64 #include <sys/module.h>
66 #include <sys/syscall.h>
67 #include <sys/syscallsubr.h>
68 #include <sys/sysent.h>
69 #include <sys/sysctl.h>
70 #include <sys/malloc.h>
73 #include <security/mac/mac_framework.h>
75 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
77 static void msginit(void);
78 static int msgunload(void);
79 static int sysvmsg_modload(struct module *, int, void *);
82 #define DPRINTF(a) printf a
87 static void msg_freehdr(struct msg *msghdr);
89 /* XXX casting to (sy_call_t *) is bogus, as usual. */
90 static sy_call_t *msgcalls[] = {
91 (sy_call_t *)msgctl, (sy_call_t *)msgget,
92 (sy_call_t *)msgsnd, (sy_call_t *)msgrcv
96 #define MSGSSZ 8 /* Each segment must be 2^N long */
99 #define MSGSEG 2048 /* must be less than 32767 */
101 #define MSGMAX (MSGSSZ*MSGSEG)
103 #define MSGMNB 2048 /* max # of bytes in a queue */
113 * Based on the configuration parameters described in an SVR2 (yes, two)
114 * config(1m) man page.
116 * Each message is broken up and stored in segments that are msgssz bytes
117 * long. For efficiency reasons, this should be a power of two. Also,
118 * it doesn't make sense if it is less than 8 or greater than about 256.
119 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
120 * two between 8 and 1024 inclusive (and panic's if it isn't).
122 struct msginfo msginfo = {
123 MSGMAX, /* max chars in a message */
124 MSGMNI, /* # of message queue identifiers */
125 MSGMNB, /* max chars in a queue */
126 MSGTQL, /* max messages in system */
127 MSGSSZ, /* size of a message segment */
128 /* (must be small power of 2 greater than 4) */
129 MSGSEG /* number of message segments */
133 * macros to convert between msqid_ds's and msqid's.
134 * (specific to this implementation)
136 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
137 #define MSQID_IX(id) ((id) & 0xffff)
138 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
141 * The rest of this file is specific to this particular implementation.
145 short next; /* next segment in buffer */
146 /* -1 -> available */
147 /* 0..(MSGSEG-1) -> index of next segment */
150 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
152 static int nfree_msgmaps; /* # of free map entries */
153 static short free_msgmaps; /* head of linked list of free map entries */
154 static struct msg *free_msghdrs;/* list of free msg headers */
155 static char *msgpool; /* MSGMAX byte long msg buffer pool */
156 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
157 static struct msg *msghdrs; /* MSGTQL msg headers */
158 static struct msqid_kernel *msqids; /* MSGMNI msqid_kernel struct's */
159 static struct mtx msq_mtx; /* global mutex for message queues. */
166 TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg);
167 TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz);
168 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
169 TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni);
170 TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb);
171 TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql);
173 msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
175 panic("msgpool is NULL");
176 msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
178 panic("msgmaps is NULL");
179 msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
181 panic("msghdrs is NULL");
182 msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
185 panic("msqids is NULL");
188 * msginfo.msgssz should be a power of two for efficiency reasons.
189 * It is also pretty silly if msginfo.msgssz is less than 8
190 * or greater than about 256 so ...
194 while (i < 1024 && i != msginfo.msgssz)
196 if (i != msginfo.msgssz) {
197 DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
199 panic("msginfo.msgssz not a small power of 2");
202 if (msginfo.msgseg > 32767) {
203 DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
204 panic("msginfo.msgseg > 32767");
208 panic("msgmaps is NULL");
210 for (i = 0; i < msginfo.msgseg; i++) {
212 msgmaps[i-1].next = i;
213 msgmaps[i].next = -1; /* implies entry is available */
216 nfree_msgmaps = msginfo.msgseg;
219 panic("msghdrs is NULL");
221 for (i = 0; i < msginfo.msgtql; i++) {
222 msghdrs[i].msg_type = 0;
224 msghdrs[i-1].msg_next = &msghdrs[i];
225 msghdrs[i].msg_next = NULL;
227 mac_init_sysv_msgmsg(&msghdrs[i]);
230 free_msghdrs = &msghdrs[0];
233 panic("msqids is NULL");
235 for (i = 0; i < msginfo.msgmni; i++) {
236 msqids[i].u.msg_qbytes = 0; /* implies entry is available */
237 msqids[i].u.msg_perm.seq = 0; /* reset to a known value */
238 msqids[i].u.msg_perm.mode = 0;
240 mac_init_sysv_msgqueue(&msqids[i]);
243 mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
249 struct msqid_kernel *msqkptr;
255 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
257 * Look for an unallocated and unlocked msqid_ds.
258 * msqid_ds's can be locked by msgsnd or msgrcv while
259 * they are copying the message in/out. We can't
260 * re-use the entry until they release it.
262 msqkptr = &msqids[msqid];
263 if (msqkptr->u.msg_qbytes != 0 ||
264 (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
267 if (msqid != msginfo.msgmni)
271 for (i = 0; i < msginfo.msgtql; i++)
272 mac_destroy_sysv_msgmsg(&msghdrs[i]);
273 for (msqid = 0; msqid < msginfo.msgmni; msqid++)
274 mac_destroy_sysv_msgqueue(&msqids[msqid]);
276 free(msgpool, M_MSG);
277 free(msgmaps, M_MSG);
278 free(msghdrs, M_MSG);
280 mtx_destroy(&msq_mtx);
286 sysvmsg_modload(struct module *module, int cmd, void *arg)
306 static moduledata_t sysvmsg_mod = {
312 SYSCALL_MODULE_HELPER(msgsys);
313 SYSCALL_MODULE_HELPER(msgctl);
314 SYSCALL_MODULE_HELPER(msgget);
315 SYSCALL_MODULE_HELPER(msgsnd);
316 SYSCALL_MODULE_HELPER(msgrcv);
318 DECLARE_MODULE(sysvmsg, sysvmsg_mod,
319 SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
320 MODULE_VERSION(sysvmsg, 1);
323 * Entry point for all MSG calls.
328 /* XXX actually varargs. */
329 struct msgsys_args /* {
340 if (!jail_sysvipc_allowed && jailed(td->td_ucred))
342 if (uap->which < 0 ||
343 uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
345 error = (*msgcalls[uap->which])(td, &uap->a2);
353 while (msghdr->msg_ts > 0) {
355 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
356 panic("msghdr->msg_spot out of range");
357 next = msgmaps[msghdr->msg_spot].next;
358 msgmaps[msghdr->msg_spot].next = free_msgmaps;
359 free_msgmaps = msghdr->msg_spot;
361 msghdr->msg_spot = next;
362 if (msghdr->msg_ts >= msginfo.msgssz)
363 msghdr->msg_ts -= msginfo.msgssz;
367 if (msghdr->msg_spot != -1)
368 panic("msghdr->msg_spot != -1");
369 msghdr->msg_next = free_msghdrs;
370 free_msghdrs = msghdr;
372 mac_cleanup_sysv_msgmsg(msghdr);
376 #ifndef _SYS_SYSPROTO_H_
380 struct msqid_ds *buf;
386 register struct msgctl_args *uap;
388 int msqid = uap->msqid;
390 struct msqid_ds msqbuf;
393 DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
394 if (cmd == IPC_SET &&
395 (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
397 error = kern_msgctl(td, msqid, cmd, &msqbuf);
398 if (cmd == IPC_STAT && error == 0)
399 error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
404 kern_msgctl(td, msqid, cmd, msqbuf)
408 struct msqid_ds *msqbuf;
410 int rval, error, msqix;
411 register struct msqid_kernel *msqkptr;
413 if (!jail_sysvipc_allowed && jailed(td->td_ucred))
416 msqix = IPCID_TO_IX(msqid);
418 if (msqix < 0 || msqix >= msginfo.msgmni) {
419 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
424 msqkptr = &msqids[msqix];
427 if (msqkptr->u.msg_qbytes == 0) {
428 DPRINTF(("no such msqid\n"));
432 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
433 DPRINTF(("wrong sequence number\n"));
438 error = mac_check_sysv_msqctl(td->td_ucred, msqkptr, cmd);
451 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
456 * Check that the thread has MAC access permissions to
457 * individual msghdrs. Note: We need to do this in a
458 * separate loop because the actual loop alters the
459 * msq/msghdr info as it progresses, and there is no going
460 * back if half the way through we discover that the
461 * thread cannot free a certain msghdr. The msq will get
462 * into an inconsistent state.
464 for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
465 msghdr = msghdr->msg_next) {
466 error = mac_check_sysv_msgrmid(td->td_ucred, msghdr);
472 /* Free the message headers */
473 msghdr = msqkptr->u.msg_first;
474 while (msghdr != NULL) {
475 struct msg *msghdr_tmp;
477 /* Free the segments of each message */
478 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
479 msqkptr->u.msg_qnum--;
481 msghdr = msghdr->msg_next;
482 msg_freehdr(msghdr_tmp);
485 if (msqkptr->u.msg_cbytes != 0)
486 panic("msg_cbytes is screwed up");
487 if (msqkptr->u.msg_qnum != 0)
488 panic("msg_qnum is screwed up");
490 msqkptr->u.msg_qbytes = 0; /* Mark it as free */
493 mac_cleanup_sysv_msgqueue(msqkptr);
502 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
504 if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
505 error = priv_check_cred(td->td_ucred,
506 PRIV_IPC_MSGSIZE, SUSER_ALLOWJAIL);
510 if (msqbuf->msg_qbytes > msginfo.msgmnb) {
511 DPRINTF(("can't increase msg_qbytes beyond %d"
512 "(truncating)\n", msginfo.msgmnb));
513 msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
515 if (msqbuf->msg_qbytes == 0) {
516 DPRINTF(("can't reduce msg_qbytes to 0\n"));
517 error = EINVAL; /* non-standard errno! */
520 msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */
521 msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */
522 msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
523 (msqbuf->msg_perm.mode & 0777);
524 msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
525 msqkptr->u.msg_ctime = time_second;
529 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
530 DPRINTF(("requester doesn't have read access\n"));
533 *msqbuf = msqkptr->u;
537 DPRINTF(("invalid command %d\n", cmd));
543 td->td_retval[0] = rval;
545 mtx_unlock(&msq_mtx);
549 #ifndef _SYS_SYSPROTO_H_
558 register struct msgget_args *uap;
560 int msqid, error = 0;
562 int msgflg = uap->msgflg;
563 struct ucred *cred = td->td_ucred;
564 register struct msqid_kernel *msqkptr = NULL;
566 DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
568 if (!jail_sysvipc_allowed && jailed(td->td_ucred))
572 if (key != IPC_PRIVATE) {
573 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
574 msqkptr = &msqids[msqid];
575 if (msqkptr->u.msg_qbytes != 0 &&
576 msqkptr->u.msg_perm.key == key)
579 if (msqid < msginfo.msgmni) {
580 DPRINTF(("found public key\n"));
581 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
582 DPRINTF(("not exclusive\n"));
586 if ((error = ipcperm(td, &msqkptr->u.msg_perm,
588 DPRINTF(("requester doesn't have 0%o access\n",
593 error = mac_check_sysv_msqget(cred, msqkptr);
601 DPRINTF(("need to allocate the msqid_ds\n"));
602 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
603 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
605 * Look for an unallocated and unlocked msqid_ds.
606 * msqid_ds's can be locked by msgsnd or msgrcv while
607 * they are copying the message in/out. We can't
608 * re-use the entry until they release it.
610 msqkptr = &msqids[msqid];
611 if (msqkptr->u.msg_qbytes == 0 &&
612 (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
615 if (msqid == msginfo.msgmni) {
616 DPRINTF(("no more msqid_ds's available\n"));
620 DPRINTF(("msqid %d is available\n", msqid));
621 msqkptr->u.msg_perm.key = key;
622 msqkptr->u.msg_perm.cuid = cred->cr_uid;
623 msqkptr->u.msg_perm.uid = cred->cr_uid;
624 msqkptr->u.msg_perm.cgid = cred->cr_gid;
625 msqkptr->u.msg_perm.gid = cred->cr_gid;
626 msqkptr->u.msg_perm.mode = (msgflg & 0777);
627 /* Make sure that the returned msqid is unique */
628 msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
629 msqkptr->u.msg_first = NULL;
630 msqkptr->u.msg_last = NULL;
631 msqkptr->u.msg_cbytes = 0;
632 msqkptr->u.msg_qnum = 0;
633 msqkptr->u.msg_qbytes = msginfo.msgmnb;
634 msqkptr->u.msg_lspid = 0;
635 msqkptr->u.msg_lrpid = 0;
636 msqkptr->u.msg_stime = 0;
637 msqkptr->u.msg_rtime = 0;
638 msqkptr->u.msg_ctime = time_second;
640 mac_create_sysv_msgqueue(cred, msqkptr);
643 DPRINTF(("didn't find it and wasn't asked to create it\n"));
649 /* Construct the unique msqid */
650 td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
652 mtx_unlock(&msq_mtx);
656 #ifndef _SYS_SYSPROTO_H_
665 kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
668 const void *msgp; /* XXX msgp is actually mtext. */
673 int msqix, segs_needed, error = 0;
674 register struct msqid_kernel *msqkptr;
675 register struct msg *msghdr;
678 if (!jail_sysvipc_allowed && jailed(td->td_ucred))
682 msqix = IPCID_TO_IX(msqid);
684 if (msqix < 0 || msqix >= msginfo.msgmni) {
685 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
691 msqkptr = &msqids[msqix];
692 if (msqkptr->u.msg_qbytes == 0) {
693 DPRINTF(("no such message queue id\n"));
697 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
698 DPRINTF(("wrong sequence number\n"));
703 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
704 DPRINTF(("requester doesn't have write access\n"));
709 error = mac_check_sysv_msqsnd(td->td_ucred, msqkptr);
714 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
715 DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
716 msginfo.msgssz, segs_needed));
718 int need_more_resources = 0;
722 * (inside this loop in case msg_qbytes changes while we sleep)
725 if (msgsz > msqkptr->u.msg_qbytes) {
726 DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
731 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
732 DPRINTF(("msqid is locked\n"));
733 need_more_resources = 1;
735 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
736 DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
737 need_more_resources = 1;
739 if (segs_needed > nfree_msgmaps) {
740 DPRINTF(("segs_needed > nfree_msgmaps\n"));
741 need_more_resources = 1;
743 if (free_msghdrs == NULL) {
744 DPRINTF(("no more msghdrs\n"));
745 need_more_resources = 1;
748 if (need_more_resources) {
751 if ((msgflg & IPC_NOWAIT) != 0) {
752 DPRINTF(("need more resources but caller "
753 "doesn't want to wait\n"));
758 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
759 DPRINTF(("we don't own the msqid_ds\n"));
762 /* Force later arrivals to wait for our
764 DPRINTF(("we own the msqid_ds\n"));
765 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
768 DPRINTF(("msgsnd: goodnight\n"));
769 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
771 DPRINTF(("msgsnd: good morning, error=%d\n", error));
773 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
774 if (error == EWOULDBLOCK) {
775 DPRINTF(("msgsnd: timed out\n"));
779 DPRINTF(("msgsnd: interrupted system call\n"));
785 * Make sure that the msq queue still exists
788 if (msqkptr->u.msg_qbytes == 0) {
789 DPRINTF(("msqid deleted\n"));
795 DPRINTF(("got all the resources that we need\n"));
801 * We have the resources that we need.
805 if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
806 panic("msg_perm.mode & MSG_LOCKED");
807 if (segs_needed > nfree_msgmaps)
808 panic("segs_needed > nfree_msgmaps");
809 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
810 panic("msgsz + msg_cbytes > msg_qbytes");
811 if (free_msghdrs == NULL)
812 panic("no more msghdrs");
815 * Re-lock the msqid_ds in case we page-fault when copying in the
819 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
820 panic("msqid_ds is already locked");
821 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
824 * Allocate a message header
827 msghdr = free_msghdrs;
828 free_msghdrs = msghdr->msg_next;
829 msghdr->msg_spot = -1;
830 msghdr->msg_ts = msgsz;
831 msghdr->msg_type = mtype;
834 * XXXMAC: Should the mac_check_sysv_msgmsq check follow here
835 * immediately? Or, should it be checked just before the msg is
836 * enqueued in the msgq (as it is done now)?
838 mac_create_sysv_msgmsg(td->td_ucred, msqkptr, msghdr);
842 * Allocate space for the message
845 while (segs_needed > 0) {
846 if (nfree_msgmaps <= 0)
847 panic("not enough msgmaps");
848 if (free_msgmaps == -1)
849 panic("nil free_msgmaps");
852 panic("next too low #1");
853 if (next >= msginfo.msgseg)
854 panic("next out of range #1");
855 DPRINTF(("allocating segment %d to message\n", next));
856 free_msgmaps = msgmaps[next].next;
858 msgmaps[next].next = msghdr->msg_spot;
859 msghdr->msg_spot = next;
864 * Validate the message type
867 if (msghdr->msg_type < 1) {
869 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
871 DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
877 * Copy in the message body
880 next = msghdr->msg_spot;
883 if (msgsz > msginfo.msgssz)
884 tlen = msginfo.msgssz;
888 panic("next too low #2");
889 if (next >= msginfo.msgseg)
890 panic("next out of range #2");
891 mtx_unlock(&msq_mtx);
892 if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
895 DPRINTF(("error %d copying in message segment\n",
898 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
904 msgp = (const char *)msgp + tlen;
905 next = msgmaps[next].next;
908 panic("didn't use all the msg segments");
911 * We've got the message. Unlock the msqid_ds.
914 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
917 * Make sure that the msqid_ds is still allocated.
920 if (msqkptr->u.msg_qbytes == 0) {
929 * Note: Since the task/thread allocates the msghdr and usually
930 * primes it with its own MAC label, for a majority of policies, it
931 * won't be necessary to check whether the msghdr has access
932 * permissions to the msgq. The mac_check_sysv_msqsnd check would
933 * suffice in that case. However, this hook may be required where
934 * individual policies derive a non-identical label for the msghdr
935 * from the current thread label and may want to check the msghdr
936 * enqueue permissions, along with read/write permissions to the
939 error = mac_check_sysv_msgmsq(td->td_ucred, msghdr, msqkptr);
948 * Put the message into the queue
950 if (msqkptr->u.msg_first == NULL) {
951 msqkptr->u.msg_first = msghdr;
952 msqkptr->u.msg_last = msghdr;
954 msqkptr->u.msg_last->msg_next = msghdr;
955 msqkptr->u.msg_last = msghdr;
957 msqkptr->u.msg_last->msg_next = NULL;
959 msqkptr->u.msg_cbytes += msghdr->msg_ts;
960 msqkptr->u.msg_qnum++;
961 msqkptr->u.msg_lspid = td->td_proc->p_pid;
962 msqkptr->u.msg_stime = time_second;
965 td->td_retval[0] = 0;
967 mtx_unlock(&msq_mtx);
974 register struct msgsnd_args *uap;
979 DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
980 uap->msgsz, uap->msgflg));
982 if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
983 DPRINTF(("error %d copying the message type\n", error));
986 return (kern_msgsnd(td, uap->msqid,
987 (const char *)uap->msgp + sizeof(mtype),
988 uap->msgsz, uap->msgflg, mtype));
991 #ifndef _SYS_SYSPROTO_H_
1001 kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
1004 void *msgp; /* XXX msgp is actually mtext. */
1011 register struct msqid_kernel *msqkptr;
1012 register struct msg *msghdr;
1013 int msqix, error = 0;
1016 if (!jail_sysvipc_allowed && jailed(td->td_ucred))
1019 msqix = IPCID_TO_IX(msqid);
1021 if (msqix < 0 || msqix >= msginfo.msgmni) {
1022 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
1027 msqkptr = &msqids[msqix];
1029 if (msqkptr->u.msg_qbytes == 0) {
1030 DPRINTF(("no such message queue id\n"));
1034 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1035 DPRINTF(("wrong sequence number\n"));
1040 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1041 DPRINTF(("requester doesn't have read access\n"));
1046 error = mac_check_sysv_msqrcv(td->td_ucred, msqkptr);
1052 while (msghdr == NULL) {
1054 msghdr = msqkptr->u.msg_first;
1055 if (msghdr != NULL) {
1056 if (msgsz < msghdr->msg_ts &&
1057 (msgflg & MSG_NOERROR) == 0) {
1058 DPRINTF(("first message on the queue "
1059 "is too big (want %zu, got %d)\n",
1060 msgsz, msghdr->msg_ts));
1065 error = mac_check_sysv_msgrcv(td->td_ucred,
1070 if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1071 msqkptr->u.msg_first = NULL;
1072 msqkptr->u.msg_last = NULL;
1074 msqkptr->u.msg_first = msghdr->msg_next;
1075 if (msqkptr->u.msg_first == NULL)
1076 panic("msg_first/last screwed up #1");
1080 struct msg *previous;
1084 prev = &(msqkptr->u.msg_first);
1085 while ((msghdr = *prev) != NULL) {
1087 * Is this message's type an exact match or is
1088 * this message's type less than or equal to
1089 * the absolute value of a negative msgtyp?
1090 * Note that the second half of this test can
1091 * NEVER be true if msgtyp is positive since
1092 * msg_type is always positive!
1095 if (msgtyp == msghdr->msg_type ||
1096 msghdr->msg_type <= -msgtyp) {
1097 DPRINTF(("found message type %ld, "
1099 msghdr->msg_type, msgtyp));
1100 if (msgsz < msghdr->msg_ts &&
1101 (msgflg & MSG_NOERROR) == 0) {
1102 DPRINTF(("requested message "
1103 "on the queue is too big "
1104 "(want %zu, got %hu)\n",
1105 msgsz, msghdr->msg_ts));
1110 error = mac_check_sysv_msgrcv(
1111 td->td_ucred, msghdr);
1115 *prev = msghdr->msg_next;
1116 if (msghdr == msqkptr->u.msg_last) {
1117 if (previous == NULL) {
1119 &msqkptr->u.msg_first)
1120 panic("msg_first/last screwed up #2");
1121 msqkptr->u.msg_first =
1123 msqkptr->u.msg_last =
1127 &msqkptr->u.msg_first)
1128 panic("msg_first/last screwed up #3");
1129 msqkptr->u.msg_last =
1136 prev = &(msghdr->msg_next);
1141 * We've either extracted the msghdr for the appropriate
1142 * message or there isn't one.
1143 * If there is one then bail out of this loop.
1150 * Hmph! No message found. Does the user want to wait?
1153 if ((msgflg & IPC_NOWAIT) != 0) {
1154 DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1156 /* The SVID says to return ENOMSG. */
1162 * Wait for something to happen
1165 DPRINTF(("msgrcv: goodnight\n"));
1166 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1168 DPRINTF(("msgrcv: good morning (error=%d)\n", error));
1171 DPRINTF(("msgrcv: interrupted system call\n"));
1177 * Make sure that the msq queue still exists
1180 if (msqkptr->u.msg_qbytes == 0 ||
1181 msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1182 DPRINTF(("msqid deleted\n"));
1189 * Return the message to the user.
1191 * First, do the bookkeeping (before we risk being interrupted).
1194 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1195 msqkptr->u.msg_qnum--;
1196 msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1197 msqkptr->u.msg_rtime = time_second;
1200 * Make msgsz the actual amount that we'll be returning.
1201 * Note that this effectively truncates the message if it is too long
1202 * (since msgsz is never increased).
1205 DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1207 if (msgsz > msghdr->msg_ts)
1208 msgsz = msghdr->msg_ts;
1209 *mtype = msghdr->msg_type;
1212 * Return the segments to the user
1215 next = msghdr->msg_spot;
1216 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1219 if (msgsz - len > msginfo.msgssz)
1220 tlen = msginfo.msgssz;
1224 panic("next too low #3");
1225 if (next >= msginfo.msgseg)
1226 panic("next out of range #3");
1227 mtx_unlock(&msq_mtx);
1228 error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1231 DPRINTF(("error (%d) copying out message segment\n",
1233 msg_freehdr(msghdr);
1237 msgp = (char *)msgp + tlen;
1238 next = msgmaps[next].next;
1242 * Done, return the actual number of bytes copied out.
1245 msg_freehdr(msghdr);
1247 td->td_retval[0] = msgsz;
1249 mtx_unlock(&msq_mtx);
1256 register struct msgrcv_args *uap;
1261 DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1262 uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1264 if ((error = kern_msgrcv(td, uap->msqid,
1265 (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1266 uap->msgtyp, uap->msgflg, &mtype)) != 0)
1268 if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1269 DPRINTF(("error %d copying the message type\n", error));
1274 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1277 return (SYSCTL_OUT(req, msqids,
1278 sizeof(struct msqid_kernel) * msginfo.msgmni));
1281 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1282 "Maximum message size");
1283 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1284 "Number of message queue identifiers");
1285 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1286 "Maximum number of bytes in a queue");
1287 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1288 "Maximum number of messages in the system");
1289 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1290 "Size of a message segment");
1291 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1292 "Number of message segments");
1293 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1294 NULL, 0, sysctl_msqids, "", "Message queue IDs");