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_compat.h"
54 #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/racct.h>
67 #include <sys/syscall.h>
68 #include <sys/syscallsubr.h>
69 #include <sys/sysent.h>
70 #include <sys/sysctl.h>
71 #include <sys/malloc.h>
74 #include <security/mac/mac_framework.h>
76 FEATURE(sysv_msg, "System V message queues support");
78 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
80 static int msginit(void);
81 static int msgunload(void);
82 static int sysvmsg_modload(struct module *, int, void *);
86 #define DPRINTF(a) printf a
88 #define DPRINTF(a) (void)0
91 static void msg_freehdr(struct msg *msghdr);
94 #define MSGSSZ 8 /* Each segment must be 2^N long */
97 #define MSGSEG 2048 /* must be less than 32767 */
99 #define MSGMAX (MSGSSZ*MSGSEG)
101 #define MSGMNB 2048 /* max # of bytes in a queue */
111 * Based on the configuration parameters described in an SVR2 (yes, two)
112 * config(1m) man page.
114 * Each message is broken up and stored in segments that are msgssz bytes
115 * long. For efficiency reasons, this should be a power of two. Also,
116 * it doesn't make sense if it is less than 8 or greater than about 256.
117 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
118 * two between 8 and 1024 inclusive (and panic's if it isn't).
120 struct msginfo msginfo = {
121 MSGMAX, /* max chars in a message */
122 MSGMNI, /* # of message queue identifiers */
123 MSGMNB, /* max chars in a queue */
124 MSGTQL, /* max messages in system */
125 MSGSSZ, /* size of a message segment */
126 /* (must be small power of 2 greater than 4) */
127 MSGSEG /* number of message segments */
131 * macros to convert between msqid_ds's and msqid's.
132 * (specific to this implementation)
134 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
135 #define MSQID_IX(id) ((id) & 0xffff)
136 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
139 * The rest of this file is specific to this particular implementation.
143 short next; /* next segment in buffer */
144 /* -1 -> available */
145 /* 0..(MSGSEG-1) -> index of next segment */
148 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
150 static int nfree_msgmaps; /* # of free map entries */
151 static short free_msgmaps; /* head of linked list of free map entries */
152 static struct msg *free_msghdrs;/* list of free msg headers */
153 static char *msgpool; /* MSGMAX byte long msg buffer pool */
154 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
155 static struct msg *msghdrs; /* MSGTQL msg headers */
156 static struct msqid_kernel *msqids; /* MSGMNI msqid_kernel struct's */
157 static struct mtx msq_mtx; /* global mutex for message queues. */
159 static struct syscall_helper_data msg_syscalls[] = {
160 SYSCALL_INIT_HELPER(msgctl),
161 SYSCALL_INIT_HELPER(msgget),
162 SYSCALL_INIT_HELPER(msgsnd),
163 SYSCALL_INIT_HELPER(msgrcv),
164 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
165 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
166 SYSCALL_INIT_HELPER(msgsys),
167 SYSCALL_INIT_HELPER_COMPAT(freebsd7_msgctl),
172 #ifdef COMPAT_FREEBSD32
173 #include <compat/freebsd32/freebsd32.h>
174 #include <compat/freebsd32/freebsd32_ipc.h>
175 #include <compat/freebsd32/freebsd32_proto.h>
176 #include <compat/freebsd32/freebsd32_signal.h>
177 #include <compat/freebsd32/freebsd32_syscall.h>
178 #include <compat/freebsd32/freebsd32_util.h>
180 static struct syscall_helper_data msg32_syscalls[] = {
181 SYSCALL32_INIT_HELPER(freebsd32_msgctl),
182 SYSCALL32_INIT_HELPER(freebsd32_msgsnd),
183 SYSCALL32_INIT_HELPER(freebsd32_msgrcv),
184 SYSCALL32_INIT_HELPER_COMPAT(msgget),
185 SYSCALL32_INIT_HELPER(freebsd32_msgsys),
186 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
187 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
188 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_msgctl),
199 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
200 msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
201 msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
202 msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
203 msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
207 * msginfo.msgssz should be a power of two for efficiency reasons.
208 * It is also pretty silly if msginfo.msgssz is less than 8
209 * or greater than about 256 so ...
213 while (i < 1024 && i != msginfo.msgssz)
215 if (i != msginfo.msgssz) {
216 DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
218 panic("msginfo.msgssz not a small power of 2");
221 if (msginfo.msgseg > 32767) {
222 DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
223 panic("msginfo.msgseg > 32767");
226 for (i = 0; i < msginfo.msgseg; i++) {
228 msgmaps[i-1].next = i;
229 msgmaps[i].next = -1; /* implies entry is available */
232 nfree_msgmaps = msginfo.msgseg;
234 for (i = 0; i < msginfo.msgtql; i++) {
235 msghdrs[i].msg_type = 0;
237 msghdrs[i-1].msg_next = &msghdrs[i];
238 msghdrs[i].msg_next = NULL;
240 mac_sysvmsg_init(&msghdrs[i]);
243 free_msghdrs = &msghdrs[0];
245 for (i = 0; i < msginfo.msgmni; i++) {
246 msqids[i].u.msg_qbytes = 0; /* implies entry is available */
247 msqids[i].u.msg_perm.seq = 0; /* reset to a known value */
248 msqids[i].u.msg_perm.mode = 0;
250 mac_sysvmsq_init(&msqids[i]);
253 mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
255 error = syscall_helper_register(msg_syscalls, SY_THR_STATIC_KLD);
258 #ifdef COMPAT_FREEBSD32
259 error = syscall32_helper_register(msg32_syscalls, SY_THR_STATIC_KLD);
269 struct msqid_kernel *msqkptr;
275 syscall_helper_unregister(msg_syscalls);
276 #ifdef COMPAT_FREEBSD32
277 syscall32_helper_unregister(msg32_syscalls);
280 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
282 * Look for an unallocated and unlocked msqid_ds.
283 * msqid_ds's can be locked by msgsnd or msgrcv while
284 * they are copying the message in/out. We can't
285 * re-use the entry until they release it.
287 msqkptr = &msqids[msqid];
288 if (msqkptr->u.msg_qbytes != 0 ||
289 (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
292 if (msqid != msginfo.msgmni)
296 for (i = 0; i < msginfo.msgtql; i++)
297 mac_sysvmsg_destroy(&msghdrs[i]);
298 for (msqid = 0; msqid < msginfo.msgmni; msqid++)
299 mac_sysvmsq_destroy(&msqids[msqid]);
301 free(msgpool, M_MSG);
302 free(msgmaps, M_MSG);
303 free(msghdrs, M_MSG);
305 mtx_destroy(&msq_mtx);
311 sysvmsg_modload(struct module *module, int cmd, void *arg)
333 static moduledata_t sysvmsg_mod = {
339 DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
340 MODULE_VERSION(sysvmsg, 1);
346 while (msghdr->msg_ts > 0) {
348 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
349 panic("msghdr->msg_spot out of range");
350 next = msgmaps[msghdr->msg_spot].next;
351 msgmaps[msghdr->msg_spot].next = free_msgmaps;
352 free_msgmaps = msghdr->msg_spot;
354 msghdr->msg_spot = next;
355 if (msghdr->msg_ts >= msginfo.msgssz)
356 msghdr->msg_ts -= msginfo.msgssz;
360 if (msghdr->msg_spot != -1)
361 panic("msghdr->msg_spot != -1");
362 msghdr->msg_next = free_msghdrs;
363 free_msghdrs = msghdr;
365 mac_sysvmsg_cleanup(msghdr);
369 #ifndef _SYS_SYSPROTO_H_
373 struct msqid_ds *buf;
379 register struct msgctl_args *uap;
381 int msqid = uap->msqid;
383 struct msqid_ds msqbuf;
386 DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
387 if (cmd == IPC_SET &&
388 (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
390 error = kern_msgctl(td, msqid, cmd, &msqbuf);
391 if (cmd == IPC_STAT && error == 0)
392 error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
397 kern_msgctl(td, msqid, cmd, msqbuf)
401 struct msqid_ds *msqbuf;
403 int rval, error, msqix;
404 register struct msqid_kernel *msqkptr;
406 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
409 msqix = IPCID_TO_IX(msqid);
411 if (msqix < 0 || msqix >= msginfo.msgmni) {
412 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
417 msqkptr = &msqids[msqix];
420 if (msqkptr->u.msg_qbytes == 0) {
421 DPRINTF(("no such msqid\n"));
425 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
426 DPRINTF(("wrong sequence number\n"));
431 error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
444 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
449 * Check that the thread has MAC access permissions to
450 * individual msghdrs. Note: We need to do this in a
451 * separate loop because the actual loop alters the
452 * msq/msghdr info as it progresses, and there is no going
453 * back if half the way through we discover that the
454 * thread cannot free a certain msghdr. The msq will get
455 * into an inconsistent state.
457 for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
458 msghdr = msghdr->msg_next) {
459 error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
465 racct_sub_cred(msqkptr->cred, RACCT_NMSGQ, 1);
466 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, msqkptr->u.msg_qnum);
467 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msqkptr->u.msg_cbytes);
468 crfree(msqkptr->cred);
469 msqkptr->cred = NULL;
471 /* Free the message headers */
472 msghdr = msqkptr->u.msg_first;
473 while (msghdr != NULL) {
474 struct msg *msghdr_tmp;
476 /* Free the segments of each message */
477 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
478 msqkptr->u.msg_qnum--;
480 msghdr = msghdr->msg_next;
481 msg_freehdr(msghdr_tmp);
484 if (msqkptr->u.msg_cbytes != 0)
485 panic("msg_cbytes is screwed up");
486 if (msqkptr->u.msg_qnum != 0)
487 panic("msg_qnum is screwed up");
489 msqkptr->u.msg_qbytes = 0; /* Mark it as free */
492 mac_sysvmsq_cleanup(msqkptr);
501 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
503 if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
504 error = priv_check(td, PRIV_IPC_MSGSIZE);
508 if (msqbuf->msg_qbytes > msginfo.msgmnb) {
509 DPRINTF(("can't increase msg_qbytes beyond %d"
510 "(truncating)\n", msginfo.msgmnb));
511 msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
513 if (msqbuf->msg_qbytes == 0) {
514 DPRINTF(("can't reduce msg_qbytes to 0\n"));
515 error = EINVAL; /* non-standard errno! */
518 msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */
519 msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */
520 msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
521 (msqbuf->msg_perm.mode & 0777);
522 msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
523 msqkptr->u.msg_ctime = time_second;
527 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
528 DPRINTF(("requester doesn't have read access\n"));
531 *msqbuf = msqkptr->u;
535 DPRINTF(("invalid command %d\n", cmd));
541 td->td_retval[0] = rval;
543 mtx_unlock(&msq_mtx);
547 #ifndef _SYS_SYSPROTO_H_
557 register struct msgget_args *uap;
559 int msqid, error = 0;
561 int msgflg = uap->msgflg;
562 struct ucred *cred = td->td_ucred;
563 register struct msqid_kernel *msqkptr = NULL;
565 DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
567 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
571 if (key != IPC_PRIVATE) {
572 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
573 msqkptr = &msqids[msqid];
574 if (msqkptr->u.msg_qbytes != 0 &&
575 msqkptr->u.msg_perm.key == key)
578 if (msqid < msginfo.msgmni) {
579 DPRINTF(("found public key\n"));
580 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
581 DPRINTF(("not exclusive\n"));
585 if ((error = ipcperm(td, &msqkptr->u.msg_perm,
587 DPRINTF(("requester doesn't have 0%o access\n",
592 error = mac_sysvmsq_check_msqget(cred, msqkptr);
600 DPRINTF(("need to allocate the msqid_ds\n"));
601 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
602 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
604 * Look for an unallocated and unlocked msqid_ds.
605 * msqid_ds's can be locked by msgsnd or msgrcv while
606 * they are copying the message in/out. We can't
607 * re-use the entry until they release it.
609 msqkptr = &msqids[msqid];
610 if (msqkptr->u.msg_qbytes == 0 &&
611 (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
614 if (msqid == msginfo.msgmni) {
615 DPRINTF(("no more msqid_ds's available\n"));
620 PROC_LOCK(td->td_proc);
621 error = racct_add(td->td_proc, RACCT_NMSGQ, 1);
622 PROC_UNLOCK(td->td_proc);
628 DPRINTF(("msqid %d is available\n", msqid));
629 msqkptr->u.msg_perm.key = key;
630 msqkptr->u.msg_perm.cuid = cred->cr_uid;
631 msqkptr->u.msg_perm.uid = cred->cr_uid;
632 msqkptr->u.msg_perm.cgid = cred->cr_gid;
633 msqkptr->u.msg_perm.gid = cred->cr_gid;
634 msqkptr->u.msg_perm.mode = (msgflg & 0777);
635 msqkptr->cred = crhold(cred);
636 /* Make sure that the returned msqid is unique */
637 msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
638 msqkptr->u.msg_first = NULL;
639 msqkptr->u.msg_last = NULL;
640 msqkptr->u.msg_cbytes = 0;
641 msqkptr->u.msg_qnum = 0;
642 msqkptr->u.msg_qbytes = msginfo.msgmnb;
643 msqkptr->u.msg_lspid = 0;
644 msqkptr->u.msg_lrpid = 0;
645 msqkptr->u.msg_stime = 0;
646 msqkptr->u.msg_rtime = 0;
647 msqkptr->u.msg_ctime = time_second;
649 mac_sysvmsq_create(cred, msqkptr);
652 DPRINTF(("didn't find it and wasn't asked to create it\n"));
658 /* Construct the unique msqid */
659 td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
661 mtx_unlock(&msq_mtx);
665 #ifndef _SYS_SYSPROTO_H_
674 kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
677 const void *msgp; /* XXX msgp is actually mtext. */
682 int msqix, segs_needed, error = 0;
683 register struct msqid_kernel *msqkptr;
684 register struct msg *msghdr;
690 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
694 msqix = IPCID_TO_IX(msqid);
696 if (msqix < 0 || msqix >= msginfo.msgmni) {
697 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
703 msqkptr = &msqids[msqix];
704 if (msqkptr->u.msg_qbytes == 0) {
705 DPRINTF(("no such message queue id\n"));
709 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
710 DPRINTF(("wrong sequence number\n"));
715 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
716 DPRINTF(("requester doesn't have write access\n"));
721 error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
727 PROC_LOCK(td->td_proc);
728 if (racct_add(td->td_proc, RACCT_MSGQQUEUED, 1)) {
729 PROC_UNLOCK(td->td_proc);
734 if (racct_add(td->td_proc, RACCT_MSGQSIZE, msgsz)) {
735 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
736 PROC_UNLOCK(td->td_proc);
740 PROC_UNLOCK(td->td_proc);
743 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
744 DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
745 msginfo.msgssz, segs_needed));
747 int need_more_resources = 0;
751 * (inside this loop in case msg_qbytes changes while we sleep)
754 if (msgsz > msqkptr->u.msg_qbytes) {
755 DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
760 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
761 DPRINTF(("msqid is locked\n"));
762 need_more_resources = 1;
764 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
765 DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
766 need_more_resources = 1;
768 if (segs_needed > nfree_msgmaps) {
769 DPRINTF(("segs_needed > nfree_msgmaps\n"));
770 need_more_resources = 1;
772 if (free_msghdrs == NULL) {
773 DPRINTF(("no more msghdrs\n"));
774 need_more_resources = 1;
777 if (need_more_resources) {
780 if ((msgflg & IPC_NOWAIT) != 0) {
781 DPRINTF(("need more resources but caller "
782 "doesn't want to wait\n"));
787 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
788 DPRINTF(("we don't own the msqid_ds\n"));
791 /* Force later arrivals to wait for our
793 DPRINTF(("we own the msqid_ds\n"));
794 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
797 DPRINTF(("msgsnd: goodnight\n"));
798 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
800 DPRINTF(("msgsnd: good morning, error=%d\n", error));
802 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
803 if (error == EWOULDBLOCK) {
804 DPRINTF(("msgsnd: timed out\n"));
808 DPRINTF(("msgsnd: interrupted system call\n"));
814 * Make sure that the msq queue still exists
817 if (msqkptr->u.msg_qbytes == 0) {
818 DPRINTF(("msqid deleted\n"));
824 DPRINTF(("got all the resources that we need\n"));
830 * We have the resources that we need.
834 if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
835 panic("msg_perm.mode & MSG_LOCKED");
836 if (segs_needed > nfree_msgmaps)
837 panic("segs_needed > nfree_msgmaps");
838 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
839 panic("msgsz + msg_cbytes > msg_qbytes");
840 if (free_msghdrs == NULL)
841 panic("no more msghdrs");
844 * Re-lock the msqid_ds in case we page-fault when copying in the
848 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
849 panic("msqid_ds is already locked");
850 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
853 * Allocate a message header
856 msghdr = free_msghdrs;
857 free_msghdrs = msghdr->msg_next;
858 msghdr->msg_spot = -1;
859 msghdr->msg_ts = msgsz;
860 msghdr->msg_type = mtype;
863 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
864 * immediately? Or, should it be checked just before the msg is
865 * enqueued in the msgq (as it is done now)?
867 mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
871 * Allocate space for the message
874 while (segs_needed > 0) {
875 if (nfree_msgmaps <= 0)
876 panic("not enough msgmaps");
877 if (free_msgmaps == -1)
878 panic("nil free_msgmaps");
881 panic("next too low #1");
882 if (next >= msginfo.msgseg)
883 panic("next out of range #1");
884 DPRINTF(("allocating segment %d to message\n", next));
885 free_msgmaps = msgmaps[next].next;
887 msgmaps[next].next = msghdr->msg_spot;
888 msghdr->msg_spot = next;
893 * Validate the message type
896 if (msghdr->msg_type < 1) {
898 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
900 DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
906 * Copy in the message body
909 next = msghdr->msg_spot;
912 if (msgsz > msginfo.msgssz)
913 tlen = msginfo.msgssz;
917 panic("next too low #2");
918 if (next >= msginfo.msgseg)
919 panic("next out of range #2");
920 mtx_unlock(&msq_mtx);
921 if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
924 DPRINTF(("error %d copying in message segment\n",
927 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
933 msgp = (const char *)msgp + tlen;
934 next = msgmaps[next].next;
937 panic("didn't use all the msg segments");
940 * We've got the message. Unlock the msqid_ds.
943 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
946 * Make sure that the msqid_ds is still allocated.
949 if (msqkptr->u.msg_qbytes == 0) {
958 * Note: Since the task/thread allocates the msghdr and usually
959 * primes it with its own MAC label, for a majority of policies, it
960 * won't be necessary to check whether the msghdr has access
961 * permissions to the msgq. The mac_sysvmsq_check_msqsnd check would
962 * suffice in that case. However, this hook may be required where
963 * individual policies derive a non-identical label for the msghdr
964 * from the current thread label and may want to check the msghdr
965 * enqueue permissions, along with read/write permissions to the
968 error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
977 * Put the message into the queue
979 if (msqkptr->u.msg_first == NULL) {
980 msqkptr->u.msg_first = msghdr;
981 msqkptr->u.msg_last = msghdr;
983 msqkptr->u.msg_last->msg_next = msghdr;
984 msqkptr->u.msg_last = msghdr;
986 msqkptr->u.msg_last->msg_next = NULL;
988 msqkptr->u.msg_cbytes += msghdr->msg_ts;
989 msqkptr->u.msg_qnum++;
990 msqkptr->u.msg_lspid = td->td_proc->p_pid;
991 msqkptr->u.msg_stime = time_second;
994 td->td_retval[0] = 0;
998 PROC_LOCK(td->td_proc);
999 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
1000 racct_sub(td->td_proc, RACCT_MSGQSIZE, saved_msgsz);
1001 PROC_UNLOCK(td->td_proc);
1005 mtx_unlock(&msq_mtx);
1012 register struct msgsnd_args *uap;
1017 DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
1018 uap->msgsz, uap->msgflg));
1020 if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
1021 DPRINTF(("error %d copying the message type\n", error));
1024 return (kern_msgsnd(td, uap->msqid,
1025 (const char *)uap->msgp + sizeof(mtype),
1026 uap->msgsz, uap->msgflg, mtype));
1029 #ifndef _SYS_SYSPROTO_H_
1030 struct msgrcv_args {
1039 kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
1042 void *msgp; /* XXX msgp is actually mtext. */
1049 register struct msqid_kernel *msqkptr;
1050 register struct msg *msghdr;
1051 int msqix, error = 0;
1054 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1057 msqix = IPCID_TO_IX(msqid);
1059 if (msqix < 0 || msqix >= msginfo.msgmni) {
1060 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
1065 msqkptr = &msqids[msqix];
1067 if (msqkptr->u.msg_qbytes == 0) {
1068 DPRINTF(("no such message queue id\n"));
1072 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1073 DPRINTF(("wrong sequence number\n"));
1078 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1079 DPRINTF(("requester doesn't have read access\n"));
1084 error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
1090 while (msghdr == NULL) {
1092 msghdr = msqkptr->u.msg_first;
1093 if (msghdr != NULL) {
1094 if (msgsz < msghdr->msg_ts &&
1095 (msgflg & MSG_NOERROR) == 0) {
1096 DPRINTF(("first message on the queue "
1097 "is too big (want %zu, got %d)\n",
1098 msgsz, msghdr->msg_ts));
1103 error = mac_sysvmsq_check_msgrcv(td->td_ucred,
1108 if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1109 msqkptr->u.msg_first = NULL;
1110 msqkptr->u.msg_last = NULL;
1112 msqkptr->u.msg_first = msghdr->msg_next;
1113 if (msqkptr->u.msg_first == NULL)
1114 panic("msg_first/last screwed up #1");
1118 struct msg *previous;
1122 prev = &(msqkptr->u.msg_first);
1123 while ((msghdr = *prev) != NULL) {
1125 * Is this message's type an exact match or is
1126 * this message's type less than or equal to
1127 * the absolute value of a negative msgtyp?
1128 * Note that the second half of this test can
1129 * NEVER be true if msgtyp is positive since
1130 * msg_type is always positive!
1133 if (msgtyp == msghdr->msg_type ||
1134 msghdr->msg_type <= -msgtyp) {
1135 DPRINTF(("found message type %ld, "
1137 msghdr->msg_type, msgtyp));
1138 if (msgsz < msghdr->msg_ts &&
1139 (msgflg & MSG_NOERROR) == 0) {
1140 DPRINTF(("requested message "
1141 "on the queue is too big "
1142 "(want %zu, got %hu)\n",
1143 msgsz, msghdr->msg_ts));
1148 error = mac_sysvmsq_check_msgrcv(
1149 td->td_ucred, msghdr);
1153 *prev = msghdr->msg_next;
1154 if (msghdr == msqkptr->u.msg_last) {
1155 if (previous == NULL) {
1157 &msqkptr->u.msg_first)
1158 panic("msg_first/last screwed up #2");
1159 msqkptr->u.msg_first =
1161 msqkptr->u.msg_last =
1165 &msqkptr->u.msg_first)
1166 panic("msg_first/last screwed up #3");
1167 msqkptr->u.msg_last =
1174 prev = &(msghdr->msg_next);
1179 * We've either extracted the msghdr for the appropriate
1180 * message or there isn't one.
1181 * If there is one then bail out of this loop.
1188 * Hmph! No message found. Does the user want to wait?
1191 if ((msgflg & IPC_NOWAIT) != 0) {
1192 DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1194 /* The SVID says to return ENOMSG. */
1200 * Wait for something to happen
1203 DPRINTF(("msgrcv: goodnight\n"));
1204 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1206 DPRINTF(("msgrcv: good morning (error=%d)\n", error));
1209 DPRINTF(("msgrcv: interrupted system call\n"));
1215 * Make sure that the msq queue still exists
1218 if (msqkptr->u.msg_qbytes == 0 ||
1219 msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1220 DPRINTF(("msqid deleted\n"));
1227 * Return the message to the user.
1229 * First, do the bookkeeping (before we risk being interrupted).
1232 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1233 msqkptr->u.msg_qnum--;
1234 msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1235 msqkptr->u.msg_rtime = time_second;
1237 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, 1);
1238 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msghdr->msg_ts);
1241 * Make msgsz the actual amount that we'll be returning.
1242 * Note that this effectively truncates the message if it is too long
1243 * (since msgsz is never increased).
1246 DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1248 if (msgsz > msghdr->msg_ts)
1249 msgsz = msghdr->msg_ts;
1250 *mtype = msghdr->msg_type;
1253 * Return the segments to the user
1256 next = msghdr->msg_spot;
1257 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1260 if (msgsz - len > msginfo.msgssz)
1261 tlen = msginfo.msgssz;
1265 panic("next too low #3");
1266 if (next >= msginfo.msgseg)
1267 panic("next out of range #3");
1268 mtx_unlock(&msq_mtx);
1269 error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1272 DPRINTF(("error (%d) copying out message segment\n",
1274 msg_freehdr(msghdr);
1278 msgp = (char *)msgp + tlen;
1279 next = msgmaps[next].next;
1283 * Done, return the actual number of bytes copied out.
1286 msg_freehdr(msghdr);
1288 td->td_retval[0] = msgsz;
1290 mtx_unlock(&msq_mtx);
1297 register struct msgrcv_args *uap;
1302 DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1303 uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1305 if ((error = kern_msgrcv(td, uap->msqid,
1306 (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1307 uap->msgtyp, uap->msgflg, &mtype)) != 0)
1309 if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1310 DPRINTF(("error %d copying the message type\n", error));
1315 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1318 return (SYSCTL_OUT(req, msqids,
1319 sizeof(struct msqid_kernel) * msginfo.msgmni));
1322 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1323 "Maximum message size");
1324 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1325 "Number of message queue identifiers");
1326 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1327 "Maximum number of bytes in a queue");
1328 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1329 "Maximum number of messages in the system");
1330 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1331 "Size of a message segment");
1332 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1333 "Number of message segments");
1334 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLTYPE_OPAQUE | CTLFLAG_RD,
1335 NULL, 0, sysctl_msqids, "", "Message queue IDs");
1337 #ifdef COMPAT_FREEBSD32
1339 freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap)
1342 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1343 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1344 switch (uap->which) {
1346 return (freebsd7_freebsd32_msgctl(td,
1347 (struct freebsd7_freebsd32_msgctl_args *)&uap->a2));
1349 return (freebsd32_msgsnd(td,
1350 (struct freebsd32_msgsnd_args *)&uap->a2));
1352 return (freebsd32_msgrcv(td,
1353 (struct freebsd32_msgrcv_args *)&uap->a2));
1355 return (sys_msgsys(td, (struct msgsys_args *)uap));
1358 return (nosys(td, NULL));
1362 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1363 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1365 freebsd7_freebsd32_msgctl(struct thread *td,
1366 struct freebsd7_freebsd32_msgctl_args *uap)
1368 struct msqid_ds msqbuf;
1369 struct msqid_ds32_old msqbuf32;
1372 if (uap->cmd == IPC_SET) {
1373 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1376 freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1377 PTRIN_CP(msqbuf32, msqbuf, msg_first);
1378 PTRIN_CP(msqbuf32, msqbuf, msg_last);
1379 CP(msqbuf32, msqbuf, msg_cbytes);
1380 CP(msqbuf32, msqbuf, msg_qnum);
1381 CP(msqbuf32, msqbuf, msg_qbytes);
1382 CP(msqbuf32, msqbuf, msg_lspid);
1383 CP(msqbuf32, msqbuf, msg_lrpid);
1384 CP(msqbuf32, msqbuf, msg_stime);
1385 CP(msqbuf32, msqbuf, msg_rtime);
1386 CP(msqbuf32, msqbuf, msg_ctime);
1388 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1391 if (uap->cmd == IPC_STAT) {
1392 bzero(&msqbuf32, sizeof(msqbuf32));
1393 freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1394 PTROUT_CP(msqbuf, msqbuf32, msg_first);
1395 PTROUT_CP(msqbuf, msqbuf32, msg_last);
1396 CP(msqbuf, msqbuf32, msg_cbytes);
1397 CP(msqbuf, msqbuf32, msg_qnum);
1398 CP(msqbuf, msqbuf32, msg_qbytes);
1399 CP(msqbuf, msqbuf32, msg_lspid);
1400 CP(msqbuf, msqbuf32, msg_lrpid);
1401 CP(msqbuf, msqbuf32, msg_stime);
1402 CP(msqbuf, msqbuf32, msg_rtime);
1403 CP(msqbuf, msqbuf32, msg_ctime);
1404 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1411 freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap)
1413 struct msqid_ds msqbuf;
1414 struct msqid_ds32 msqbuf32;
1417 if (uap->cmd == IPC_SET) {
1418 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1421 freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1422 PTRIN_CP(msqbuf32, msqbuf, msg_first);
1423 PTRIN_CP(msqbuf32, msqbuf, msg_last);
1424 CP(msqbuf32, msqbuf, msg_cbytes);
1425 CP(msqbuf32, msqbuf, msg_qnum);
1426 CP(msqbuf32, msqbuf, msg_qbytes);
1427 CP(msqbuf32, msqbuf, msg_lspid);
1428 CP(msqbuf32, msqbuf, msg_lrpid);
1429 CP(msqbuf32, msqbuf, msg_stime);
1430 CP(msqbuf32, msqbuf, msg_rtime);
1431 CP(msqbuf32, msqbuf, msg_ctime);
1433 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1436 if (uap->cmd == IPC_STAT) {
1437 freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1438 PTROUT_CP(msqbuf, msqbuf32, msg_first);
1439 PTROUT_CP(msqbuf, msqbuf32, msg_last);
1440 CP(msqbuf, msqbuf32, msg_cbytes);
1441 CP(msqbuf, msqbuf32, msg_qnum);
1442 CP(msqbuf, msqbuf32, msg_qbytes);
1443 CP(msqbuf, msqbuf32, msg_lspid);
1444 CP(msqbuf, msqbuf32, msg_lrpid);
1445 CP(msqbuf, msqbuf32, msg_stime);
1446 CP(msqbuf, msqbuf32, msg_rtime);
1447 CP(msqbuf, msqbuf32, msg_ctime);
1448 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1454 freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap)
1461 msgp = PTRIN(uap->msgp);
1462 if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0)
1465 return (kern_msgsnd(td, uap->msqid,
1466 (const char *)msgp + sizeof(mtype32),
1467 uap->msgsz, uap->msgflg, mtype));
1471 freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap)
1478 msgp = PTRIN(uap->msgp);
1479 if ((error = kern_msgrcv(td, uap->msqid,
1480 (char *)msgp + sizeof(mtype32), uap->msgsz,
1481 uap->msgtyp, uap->msgflg, &mtype)) != 0)
1483 mtype32 = (int32_t)mtype;
1484 return (copyout(&mtype32, msgp, sizeof(mtype32)));
1488 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1489 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1491 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1492 static sy_call_t *msgcalls[] = {
1493 (sy_call_t *)freebsd7_msgctl, (sy_call_t *)sys_msgget,
1494 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
1498 * Entry point for all MSG calls.
1503 /* XXX actually varargs. */
1504 struct msgsys_args /* {
1515 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1517 if (uap->which < 0 ||
1518 uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
1520 error = (*msgcalls[uap->which])(td, &uap->a2);
1525 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0)
1528 #ifndef _SYS_SYSPROTO_H_
1529 struct freebsd7_msgctl_args {
1532 struct msqid_ds_old *buf;
1536 freebsd7_msgctl(td, uap)
1538 struct freebsd7_msgctl_args *uap;
1540 struct msqid_ds_old msqold;
1541 struct msqid_ds msqbuf;
1544 DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
1546 if (uap->cmd == IPC_SET) {
1547 error = copyin(uap->buf, &msqold, sizeof(msqold));
1550 ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
1551 CP(msqold, msqbuf, msg_first);
1552 CP(msqold, msqbuf, msg_last);
1553 CP(msqold, msqbuf, msg_cbytes);
1554 CP(msqold, msqbuf, msg_qnum);
1555 CP(msqold, msqbuf, msg_qbytes);
1556 CP(msqold, msqbuf, msg_lspid);
1557 CP(msqold, msqbuf, msg_lrpid);
1558 CP(msqold, msqbuf, msg_stime);
1559 CP(msqold, msqbuf, msg_rtime);
1560 CP(msqold, msqbuf, msg_ctime);
1562 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1565 if (uap->cmd == IPC_STAT) {
1566 bzero(&msqold, sizeof(msqold));
1567 ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
1568 CP(msqbuf, msqold, msg_first);
1569 CP(msqbuf, msqold, msg_last);
1570 CP(msqbuf, msqold, msg_cbytes);
1571 CP(msqbuf, msqold, msg_qnum);
1572 CP(msqbuf, msqold, msg_qbytes);
1573 CP(msqbuf, msqold, msg_lspid);
1574 CP(msqbuf, msqold, msg_lrpid);
1575 CP(msqbuf, msqold, msg_stime);
1576 CP(msqbuf, msqold, msg_rtime);
1577 CP(msqbuf, msqold, msg_ctime);
1578 error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
1585 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||