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/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 FEATURE(sysv_msg, "System V message queues support");
77 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
79 static int msginit(void);
80 static int msgunload(void);
81 static int sysvmsg_modload(struct module *, int, void *);
84 #define DPRINTF(a) printf a
86 #define DPRINTF(a) (void)0
89 static void msg_freehdr(struct msg *msghdr);
92 #define MSGSSZ 8 /* Each segment must be 2^N long */
95 #define MSGSEG 2048 /* must be less than 32767 */
97 #define MSGMAX (MSGSSZ*MSGSEG)
99 #define MSGMNB 2048 /* max # of bytes in a queue */
109 * Based on the configuration parameters described in an SVR2 (yes, two)
110 * config(1m) man page.
112 * Each message is broken up and stored in segments that are msgssz bytes
113 * long. For efficiency reasons, this should be a power of two. Also,
114 * it doesn't make sense if it is less than 8 or greater than about 256.
115 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
116 * two between 8 and 1024 inclusive (and panic's if it isn't).
118 struct msginfo msginfo = {
119 MSGMAX, /* max chars in a message */
120 MSGMNI, /* # of message queue identifiers */
121 MSGMNB, /* max chars in a queue */
122 MSGTQL, /* max messages in system */
123 MSGSSZ, /* size of a message segment */
124 /* (must be small power of 2 greater than 4) */
125 MSGSEG /* number of message segments */
129 * macros to convert between msqid_ds's and msqid's.
130 * (specific to this implementation)
132 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
133 #define MSQID_IX(id) ((id) & 0xffff)
134 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
137 * The rest of this file is specific to this particular implementation.
141 short next; /* next segment in buffer */
142 /* -1 -> available */
143 /* 0..(MSGSEG-1) -> index of next segment */
146 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
148 static int nfree_msgmaps; /* # of free map entries */
149 static short free_msgmaps; /* head of linked list of free map entries */
150 static struct msg *free_msghdrs;/* list of free msg headers */
151 static char *msgpool; /* MSGMAX byte long msg buffer pool */
152 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
153 static struct msg *msghdrs; /* MSGTQL msg headers */
154 static struct msqid_kernel *msqids; /* MSGMNI msqid_kernel struct's */
155 static struct mtx msq_mtx; /* global mutex for message queues. */
157 static struct syscall_helper_data msg_syscalls[] = {
158 SYSCALL_INIT_HELPER(msgctl),
159 SYSCALL_INIT_HELPER(msgget),
160 SYSCALL_INIT_HELPER(msgsnd),
161 SYSCALL_INIT_HELPER(msgrcv),
162 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
163 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
164 SYSCALL_INIT_HELPER(msgsys),
165 SYSCALL_INIT_HELPER(freebsd7_msgctl),
170 #ifdef COMPAT_FREEBSD32
171 #include <compat/freebsd32/freebsd32.h>
172 #include <compat/freebsd32/freebsd32_ipc.h>
173 #include <compat/freebsd32/freebsd32_proto.h>
174 #include <compat/freebsd32/freebsd32_signal.h>
175 #include <compat/freebsd32/freebsd32_syscall.h>
176 #include <compat/freebsd32/freebsd32_util.h>
178 static struct syscall_helper_data msg32_syscalls[] = {
179 SYSCALL32_INIT_HELPER(freebsd32_msgctl),
180 SYSCALL32_INIT_HELPER(freebsd32_msgsnd),
181 SYSCALL32_INIT_HELPER(freebsd32_msgrcv),
182 SYSCALL32_INIT_HELPER(msgget),
183 SYSCALL32_INIT_HELPER(freebsd32_msgsys),
184 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
185 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
186 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_msgctl),
197 TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg);
198 TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz);
199 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
200 TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni);
201 TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb);
202 TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql);
204 msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
205 msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
206 msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
207 msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
211 * msginfo.msgssz should be a power of two for efficiency reasons.
212 * It is also pretty silly if msginfo.msgssz is less than 8
213 * or greater than about 256 so ...
217 while (i < 1024 && i != msginfo.msgssz)
219 if (i != msginfo.msgssz) {
220 DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
222 panic("msginfo.msgssz not a small power of 2");
225 if (msginfo.msgseg > 32767) {
226 DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
227 panic("msginfo.msgseg > 32767");
230 for (i = 0; i < msginfo.msgseg; i++) {
232 msgmaps[i-1].next = i;
233 msgmaps[i].next = -1; /* implies entry is available */
236 nfree_msgmaps = msginfo.msgseg;
238 for (i = 0; i < msginfo.msgtql; i++) {
239 msghdrs[i].msg_type = 0;
241 msghdrs[i-1].msg_next = &msghdrs[i];
242 msghdrs[i].msg_next = NULL;
244 mac_sysvmsg_init(&msghdrs[i]);
247 free_msghdrs = &msghdrs[0];
249 for (i = 0; i < msginfo.msgmni; i++) {
250 msqids[i].u.msg_qbytes = 0; /* implies entry is available */
251 msqids[i].u.msg_perm.seq = 0; /* reset to a known value */
252 msqids[i].u.msg_perm.mode = 0;
254 mac_sysvmsq_init(&msqids[i]);
257 mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
259 error = syscall_helper_register(msg_syscalls);
262 #ifdef COMPAT_FREEBSD32
263 error = syscall32_helper_register(msg32_syscalls);
273 struct msqid_kernel *msqkptr;
279 syscall_helper_unregister(msg_syscalls);
280 #ifdef COMPAT_FREEBSD32
281 syscall32_helper_unregister(msg32_syscalls);
284 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
286 * Look for an unallocated and unlocked msqid_ds.
287 * msqid_ds's can be locked by msgsnd or msgrcv while
288 * they are copying the message in/out. We can't
289 * re-use the entry until they release it.
291 msqkptr = &msqids[msqid];
292 if (msqkptr->u.msg_qbytes != 0 ||
293 (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
296 if (msqid != msginfo.msgmni)
300 for (i = 0; i < msginfo.msgtql; i++)
301 mac_sysvmsg_destroy(&msghdrs[i]);
302 for (msqid = 0; msqid < msginfo.msgmni; msqid++)
303 mac_sysvmsq_destroy(&msqids[msqid]);
305 free(msgpool, M_MSG);
306 free(msgmaps, M_MSG);
307 free(msghdrs, M_MSG);
309 mtx_destroy(&msq_mtx);
315 sysvmsg_modload(struct module *module, int cmd, void *arg)
337 static moduledata_t sysvmsg_mod = {
343 DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
344 MODULE_VERSION(sysvmsg, 1);
350 while (msghdr->msg_ts > 0) {
352 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
353 panic("msghdr->msg_spot out of range");
354 next = msgmaps[msghdr->msg_spot].next;
355 msgmaps[msghdr->msg_spot].next = free_msgmaps;
356 free_msgmaps = msghdr->msg_spot;
358 msghdr->msg_spot = next;
359 if (msghdr->msg_ts >= msginfo.msgssz)
360 msghdr->msg_ts -= msginfo.msgssz;
364 if (msghdr->msg_spot != -1)
365 panic("msghdr->msg_spot != -1");
366 msghdr->msg_next = free_msghdrs;
367 free_msghdrs = msghdr;
369 mac_sysvmsg_cleanup(msghdr);
373 #ifndef _SYS_SYSPROTO_H_
377 struct msqid_ds *buf;
383 register struct msgctl_args *uap;
385 int msqid = uap->msqid;
387 struct msqid_ds msqbuf;
390 DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
391 if (cmd == IPC_SET &&
392 (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
394 error = kern_msgctl(td, msqid, cmd, &msqbuf);
395 if (cmd == IPC_STAT && error == 0)
396 error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
401 kern_msgctl(td, msqid, cmd, msqbuf)
405 struct msqid_ds *msqbuf;
407 int rval, error, msqix;
408 register struct msqid_kernel *msqkptr;
410 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
413 msqix = IPCID_TO_IX(msqid);
415 if (msqix < 0 || msqix >= msginfo.msgmni) {
416 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
421 msqkptr = &msqids[msqix];
424 if (msqkptr->u.msg_qbytes == 0) {
425 DPRINTF(("no such msqid\n"));
429 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
430 DPRINTF(("wrong sequence number\n"));
435 error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
448 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
453 * Check that the thread has MAC access permissions to
454 * individual msghdrs. Note: We need to do this in a
455 * separate loop because the actual loop alters the
456 * msq/msghdr info as it progresses, and there is no going
457 * back if half the way through we discover that the
458 * thread cannot free a certain msghdr. The msq will get
459 * into an inconsistent state.
461 for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
462 msghdr = msghdr->msg_next) {
463 error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
469 /* Free the message headers */
470 msghdr = msqkptr->u.msg_first;
471 while (msghdr != NULL) {
472 struct msg *msghdr_tmp;
474 /* Free the segments of each message */
475 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
476 msqkptr->u.msg_qnum--;
478 msghdr = msghdr->msg_next;
479 msg_freehdr(msghdr_tmp);
482 if (msqkptr->u.msg_cbytes != 0)
483 panic("msg_cbytes is screwed up");
484 if (msqkptr->u.msg_qnum != 0)
485 panic("msg_qnum is screwed up");
487 msqkptr->u.msg_qbytes = 0; /* Mark it as free */
490 mac_sysvmsq_cleanup(msqkptr);
499 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
501 if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
502 error = priv_check(td, PRIV_IPC_MSGSIZE);
506 if (msqbuf->msg_qbytes > msginfo.msgmnb) {
507 DPRINTF(("can't increase msg_qbytes beyond %d"
508 "(truncating)\n", msginfo.msgmnb));
509 msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
511 if (msqbuf->msg_qbytes == 0) {
512 DPRINTF(("can't reduce msg_qbytes to 0\n"));
513 error = EINVAL; /* non-standard errno! */
516 msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */
517 msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */
518 msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
519 (msqbuf->msg_perm.mode & 0777);
520 msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
521 msqkptr->u.msg_ctime = time_second;
525 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
526 DPRINTF(("requester doesn't have read access\n"));
529 *msqbuf = msqkptr->u;
533 DPRINTF(("invalid command %d\n", cmd));
539 td->td_retval[0] = rval;
541 mtx_unlock(&msq_mtx);
545 #ifndef _SYS_SYSPROTO_H_
554 register struct msgget_args *uap;
556 int msqid, error = 0;
558 int msgflg = uap->msgflg;
559 struct ucred *cred = td->td_ucred;
560 register struct msqid_kernel *msqkptr = NULL;
562 DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
564 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
568 if (key != IPC_PRIVATE) {
569 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
570 msqkptr = &msqids[msqid];
571 if (msqkptr->u.msg_qbytes != 0 &&
572 msqkptr->u.msg_perm.key == key)
575 if (msqid < msginfo.msgmni) {
576 DPRINTF(("found public key\n"));
577 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
578 DPRINTF(("not exclusive\n"));
582 if ((error = ipcperm(td, &msqkptr->u.msg_perm,
584 DPRINTF(("requester doesn't have 0%o access\n",
589 error = mac_sysvmsq_check_msqget(cred, msqkptr);
597 DPRINTF(("need to allocate the msqid_ds\n"));
598 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
599 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
601 * Look for an unallocated and unlocked msqid_ds.
602 * msqid_ds's can be locked by msgsnd or msgrcv while
603 * they are copying the message in/out. We can't
604 * re-use the entry until they release it.
606 msqkptr = &msqids[msqid];
607 if (msqkptr->u.msg_qbytes == 0 &&
608 (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
611 if (msqid == msginfo.msgmni) {
612 DPRINTF(("no more msqid_ds's available\n"));
616 DPRINTF(("msqid %d is available\n", msqid));
617 msqkptr->u.msg_perm.key = key;
618 msqkptr->u.msg_perm.cuid = cred->cr_uid;
619 msqkptr->u.msg_perm.uid = cred->cr_uid;
620 msqkptr->u.msg_perm.cgid = cred->cr_gid;
621 msqkptr->u.msg_perm.gid = cred->cr_gid;
622 msqkptr->u.msg_perm.mode = (msgflg & 0777);
623 /* Make sure that the returned msqid is unique */
624 msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
625 msqkptr->u.msg_first = NULL;
626 msqkptr->u.msg_last = NULL;
627 msqkptr->u.msg_cbytes = 0;
628 msqkptr->u.msg_qnum = 0;
629 msqkptr->u.msg_qbytes = msginfo.msgmnb;
630 msqkptr->u.msg_lspid = 0;
631 msqkptr->u.msg_lrpid = 0;
632 msqkptr->u.msg_stime = 0;
633 msqkptr->u.msg_rtime = 0;
634 msqkptr->u.msg_ctime = time_second;
636 mac_sysvmsq_create(cred, msqkptr);
639 DPRINTF(("didn't find it and wasn't asked to create it\n"));
645 /* Construct the unique msqid */
646 td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
648 mtx_unlock(&msq_mtx);
652 #ifndef _SYS_SYSPROTO_H_
661 kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
664 const void *msgp; /* XXX msgp is actually mtext. */
669 int msqix, segs_needed, error = 0;
670 register struct msqid_kernel *msqkptr;
671 register struct msg *msghdr;
674 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
678 msqix = IPCID_TO_IX(msqid);
680 if (msqix < 0 || msqix >= msginfo.msgmni) {
681 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
687 msqkptr = &msqids[msqix];
688 if (msqkptr->u.msg_qbytes == 0) {
689 DPRINTF(("no such message queue id\n"));
693 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
694 DPRINTF(("wrong sequence number\n"));
699 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
700 DPRINTF(("requester doesn't have write access\n"));
705 error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
710 segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
711 DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
712 msginfo.msgssz, segs_needed));
714 int need_more_resources = 0;
718 * (inside this loop in case msg_qbytes changes while we sleep)
721 if (msgsz > msqkptr->u.msg_qbytes) {
722 DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
727 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
728 DPRINTF(("msqid is locked\n"));
729 need_more_resources = 1;
731 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
732 DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
733 need_more_resources = 1;
735 if (segs_needed > nfree_msgmaps) {
736 DPRINTF(("segs_needed > nfree_msgmaps\n"));
737 need_more_resources = 1;
739 if (free_msghdrs == NULL) {
740 DPRINTF(("no more msghdrs\n"));
741 need_more_resources = 1;
744 if (need_more_resources) {
747 if ((msgflg & IPC_NOWAIT) != 0) {
748 DPRINTF(("need more resources but caller "
749 "doesn't want to wait\n"));
754 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
755 DPRINTF(("we don't own the msqid_ds\n"));
758 /* Force later arrivals to wait for our
760 DPRINTF(("we own the msqid_ds\n"));
761 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
764 DPRINTF(("msgsnd: goodnight\n"));
765 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
767 DPRINTF(("msgsnd: good morning, error=%d\n", error));
769 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
770 if (error == EWOULDBLOCK) {
771 DPRINTF(("msgsnd: timed out\n"));
775 DPRINTF(("msgsnd: interrupted system call\n"));
781 * Make sure that the msq queue still exists
784 if (msqkptr->u.msg_qbytes == 0) {
785 DPRINTF(("msqid deleted\n"));
791 DPRINTF(("got all the resources that we need\n"));
797 * We have the resources that we need.
801 if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
802 panic("msg_perm.mode & MSG_LOCKED");
803 if (segs_needed > nfree_msgmaps)
804 panic("segs_needed > nfree_msgmaps");
805 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
806 panic("msgsz + msg_cbytes > msg_qbytes");
807 if (free_msghdrs == NULL)
808 panic("no more msghdrs");
811 * Re-lock the msqid_ds in case we page-fault when copying in the
815 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
816 panic("msqid_ds is already locked");
817 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
820 * Allocate a message header
823 msghdr = free_msghdrs;
824 free_msghdrs = msghdr->msg_next;
825 msghdr->msg_spot = -1;
826 msghdr->msg_ts = msgsz;
827 msghdr->msg_type = mtype;
830 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
831 * immediately? Or, should it be checked just before the msg is
832 * enqueued in the msgq (as it is done now)?
834 mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
838 * Allocate space for the message
841 while (segs_needed > 0) {
842 if (nfree_msgmaps <= 0)
843 panic("not enough msgmaps");
844 if (free_msgmaps == -1)
845 panic("nil free_msgmaps");
848 panic("next too low #1");
849 if (next >= msginfo.msgseg)
850 panic("next out of range #1");
851 DPRINTF(("allocating segment %d to message\n", next));
852 free_msgmaps = msgmaps[next].next;
854 msgmaps[next].next = msghdr->msg_spot;
855 msghdr->msg_spot = next;
860 * Validate the message type
863 if (msghdr->msg_type < 1) {
865 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
867 DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
873 * Copy in the message body
876 next = msghdr->msg_spot;
879 if (msgsz > msginfo.msgssz)
880 tlen = msginfo.msgssz;
884 panic("next too low #2");
885 if (next >= msginfo.msgseg)
886 panic("next out of range #2");
887 mtx_unlock(&msq_mtx);
888 if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
891 DPRINTF(("error %d copying in message segment\n",
894 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
900 msgp = (const char *)msgp + tlen;
901 next = msgmaps[next].next;
904 panic("didn't use all the msg segments");
907 * We've got the message. Unlock the msqid_ds.
910 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
913 * Make sure that the msqid_ds is still allocated.
916 if (msqkptr->u.msg_qbytes == 0) {
925 * Note: Since the task/thread allocates the msghdr and usually
926 * primes it with its own MAC label, for a majority of policies, it
927 * won't be necessary to check whether the msghdr has access
928 * permissions to the msgq. The mac_sysvmsq_check_msqsnd check would
929 * suffice in that case. However, this hook may be required where
930 * individual policies derive a non-identical label for the msghdr
931 * from the current thread label and may want to check the msghdr
932 * enqueue permissions, along with read/write permissions to the
935 error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
944 * Put the message into the queue
946 if (msqkptr->u.msg_first == NULL) {
947 msqkptr->u.msg_first = msghdr;
948 msqkptr->u.msg_last = msghdr;
950 msqkptr->u.msg_last->msg_next = msghdr;
951 msqkptr->u.msg_last = msghdr;
953 msqkptr->u.msg_last->msg_next = NULL;
955 msqkptr->u.msg_cbytes += msghdr->msg_ts;
956 msqkptr->u.msg_qnum++;
957 msqkptr->u.msg_lspid = td->td_proc->p_pid;
958 msqkptr->u.msg_stime = time_second;
961 td->td_retval[0] = 0;
963 mtx_unlock(&msq_mtx);
970 register struct msgsnd_args *uap;
975 DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
976 uap->msgsz, uap->msgflg));
978 if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
979 DPRINTF(("error %d copying the message type\n", error));
982 return (kern_msgsnd(td, uap->msqid,
983 (const char *)uap->msgp + sizeof(mtype),
984 uap->msgsz, uap->msgflg, mtype));
987 #ifndef _SYS_SYSPROTO_H_
997 kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
1000 void *msgp; /* XXX msgp is actually mtext. */
1007 register struct msqid_kernel *msqkptr;
1008 register struct msg *msghdr;
1009 int msqix, error = 0;
1012 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1015 msqix = IPCID_TO_IX(msqid);
1017 if (msqix < 0 || msqix >= msginfo.msgmni) {
1018 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
1023 msqkptr = &msqids[msqix];
1025 if (msqkptr->u.msg_qbytes == 0) {
1026 DPRINTF(("no such message queue id\n"));
1030 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1031 DPRINTF(("wrong sequence number\n"));
1036 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1037 DPRINTF(("requester doesn't have read access\n"));
1042 error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
1048 while (msghdr == NULL) {
1050 msghdr = msqkptr->u.msg_first;
1051 if (msghdr != NULL) {
1052 if (msgsz < msghdr->msg_ts &&
1053 (msgflg & MSG_NOERROR) == 0) {
1054 DPRINTF(("first message on the queue "
1055 "is too big (want %zu, got %d)\n",
1056 msgsz, msghdr->msg_ts));
1061 error = mac_sysvmsq_check_msgrcv(td->td_ucred,
1066 if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1067 msqkptr->u.msg_first = NULL;
1068 msqkptr->u.msg_last = NULL;
1070 msqkptr->u.msg_first = msghdr->msg_next;
1071 if (msqkptr->u.msg_first == NULL)
1072 panic("msg_first/last screwed up #1");
1076 struct msg *previous;
1080 prev = &(msqkptr->u.msg_first);
1081 while ((msghdr = *prev) != NULL) {
1083 * Is this message's type an exact match or is
1084 * this message's type less than or equal to
1085 * the absolute value of a negative msgtyp?
1086 * Note that the second half of this test can
1087 * NEVER be true if msgtyp is positive since
1088 * msg_type is always positive!
1091 if (msgtyp == msghdr->msg_type ||
1092 msghdr->msg_type <= -msgtyp) {
1093 DPRINTF(("found message type %ld, "
1095 msghdr->msg_type, msgtyp));
1096 if (msgsz < msghdr->msg_ts &&
1097 (msgflg & MSG_NOERROR) == 0) {
1098 DPRINTF(("requested message "
1099 "on the queue is too big "
1100 "(want %zu, got %hu)\n",
1101 msgsz, msghdr->msg_ts));
1106 error = mac_sysvmsq_check_msgrcv(
1107 td->td_ucred, msghdr);
1111 *prev = msghdr->msg_next;
1112 if (msghdr == msqkptr->u.msg_last) {
1113 if (previous == NULL) {
1115 &msqkptr->u.msg_first)
1116 panic("msg_first/last screwed up #2");
1117 msqkptr->u.msg_first =
1119 msqkptr->u.msg_last =
1123 &msqkptr->u.msg_first)
1124 panic("msg_first/last screwed up #3");
1125 msqkptr->u.msg_last =
1132 prev = &(msghdr->msg_next);
1137 * We've either extracted the msghdr for the appropriate
1138 * message or there isn't one.
1139 * If there is one then bail out of this loop.
1146 * Hmph! No message found. Does the user want to wait?
1149 if ((msgflg & IPC_NOWAIT) != 0) {
1150 DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1152 /* The SVID says to return ENOMSG. */
1158 * Wait for something to happen
1161 DPRINTF(("msgrcv: goodnight\n"));
1162 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1164 DPRINTF(("msgrcv: good morning (error=%d)\n", error));
1167 DPRINTF(("msgrcv: interrupted system call\n"));
1173 * Make sure that the msq queue still exists
1176 if (msqkptr->u.msg_qbytes == 0 ||
1177 msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1178 DPRINTF(("msqid deleted\n"));
1185 * Return the message to the user.
1187 * First, do the bookkeeping (before we risk being interrupted).
1190 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1191 msqkptr->u.msg_qnum--;
1192 msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1193 msqkptr->u.msg_rtime = time_second;
1196 * Make msgsz the actual amount that we'll be returning.
1197 * Note that this effectively truncates the message if it is too long
1198 * (since msgsz is never increased).
1201 DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1203 if (msgsz > msghdr->msg_ts)
1204 msgsz = msghdr->msg_ts;
1205 *mtype = msghdr->msg_type;
1208 * Return the segments to the user
1211 next = msghdr->msg_spot;
1212 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1215 if (msgsz - len > msginfo.msgssz)
1216 tlen = msginfo.msgssz;
1220 panic("next too low #3");
1221 if (next >= msginfo.msgseg)
1222 panic("next out of range #3");
1223 mtx_unlock(&msq_mtx);
1224 error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1227 DPRINTF(("error (%d) copying out message segment\n",
1229 msg_freehdr(msghdr);
1233 msgp = (char *)msgp + tlen;
1234 next = msgmaps[next].next;
1238 * Done, return the actual number of bytes copied out.
1241 msg_freehdr(msghdr);
1243 td->td_retval[0] = msgsz;
1245 mtx_unlock(&msq_mtx);
1252 register struct msgrcv_args *uap;
1257 DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1258 uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1260 if ((error = kern_msgrcv(td, uap->msqid,
1261 (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1262 uap->msgtyp, uap->msgflg, &mtype)) != 0)
1264 if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1265 DPRINTF(("error %d copying the message type\n", error));
1270 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1273 return (SYSCTL_OUT(req, msqids,
1274 sizeof(struct msqid_kernel) * msginfo.msgmni));
1277 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1278 "Maximum message size");
1279 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1280 "Number of message queue identifiers");
1281 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1282 "Maximum number of bytes in a queue");
1283 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1284 "Maximum number of messages in the system");
1285 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1286 "Size of a message segment");
1287 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1288 "Number of message segments");
1289 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLTYPE_OPAQUE | CTLFLAG_RD,
1290 NULL, 0, sysctl_msqids, "", "Message queue IDs");
1292 #ifdef COMPAT_FREEBSD32
1294 freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap)
1297 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1298 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1299 switch (uap->which) {
1301 return (freebsd7_freebsd32_msgctl(td,
1302 (struct freebsd7_freebsd32_msgctl_args *)&uap->a2));
1304 return (freebsd32_msgsnd(td,
1305 (struct freebsd32_msgsnd_args *)&uap->a2));
1307 return (freebsd32_msgrcv(td,
1308 (struct freebsd32_msgrcv_args *)&uap->a2));
1310 return (msgsys(td, (struct msgsys_args *)uap));
1313 return (nosys(td, NULL));
1317 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1318 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1320 freebsd7_freebsd32_msgctl(struct thread *td,
1321 struct freebsd7_freebsd32_msgctl_args *uap)
1323 struct msqid_ds msqbuf;
1324 struct msqid_ds32_old msqbuf32;
1327 if (uap->cmd == IPC_SET) {
1328 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1331 freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1332 PTRIN_CP(msqbuf32, msqbuf, msg_first);
1333 PTRIN_CP(msqbuf32, msqbuf, msg_last);
1334 CP(msqbuf32, msqbuf, msg_cbytes);
1335 CP(msqbuf32, msqbuf, msg_qnum);
1336 CP(msqbuf32, msqbuf, msg_qbytes);
1337 CP(msqbuf32, msqbuf, msg_lspid);
1338 CP(msqbuf32, msqbuf, msg_lrpid);
1339 CP(msqbuf32, msqbuf, msg_stime);
1340 CP(msqbuf32, msqbuf, msg_rtime);
1341 CP(msqbuf32, msqbuf, msg_ctime);
1343 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1346 if (uap->cmd == IPC_STAT) {
1347 bzero(&msqbuf32, sizeof(msqbuf32));
1348 freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1349 PTROUT_CP(msqbuf, msqbuf32, msg_first);
1350 PTROUT_CP(msqbuf, msqbuf32, msg_last);
1351 CP(msqbuf, msqbuf32, msg_cbytes);
1352 CP(msqbuf, msqbuf32, msg_qnum);
1353 CP(msqbuf, msqbuf32, msg_qbytes);
1354 CP(msqbuf, msqbuf32, msg_lspid);
1355 CP(msqbuf, msqbuf32, msg_lrpid);
1356 CP(msqbuf, msqbuf32, msg_stime);
1357 CP(msqbuf, msqbuf32, msg_rtime);
1358 CP(msqbuf, msqbuf32, msg_ctime);
1359 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1366 freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap)
1368 struct msqid_ds msqbuf;
1369 struct msqid_ds32 msqbuf32;
1372 if (uap->cmd == IPC_SET) {
1373 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1376 freebsd32_ipcperm_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 freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1393 PTROUT_CP(msqbuf, msqbuf32, msg_first);
1394 PTROUT_CP(msqbuf, msqbuf32, msg_last);
1395 CP(msqbuf, msqbuf32, msg_cbytes);
1396 CP(msqbuf, msqbuf32, msg_qnum);
1397 CP(msqbuf, msqbuf32, msg_qbytes);
1398 CP(msqbuf, msqbuf32, msg_lspid);
1399 CP(msqbuf, msqbuf32, msg_lrpid);
1400 CP(msqbuf, msqbuf32, msg_stime);
1401 CP(msqbuf, msqbuf32, msg_rtime);
1402 CP(msqbuf, msqbuf32, msg_ctime);
1403 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1409 freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap)
1416 msgp = PTRIN(uap->msgp);
1417 if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0)
1420 return (kern_msgsnd(td, uap->msqid,
1421 (const char *)msgp + sizeof(mtype32),
1422 uap->msgsz, uap->msgflg, mtype));
1426 freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap)
1433 msgp = PTRIN(uap->msgp);
1434 if ((error = kern_msgrcv(td, uap->msqid,
1435 (char *)msgp + sizeof(mtype32), uap->msgsz,
1436 uap->msgtyp, uap->msgflg, &mtype)) != 0)
1438 mtype32 = (int32_t)mtype;
1439 return (copyout(&mtype32, msgp, sizeof(mtype32)));
1443 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1444 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1446 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1447 static sy_call_t *msgcalls[] = {
1448 (sy_call_t *)freebsd7_msgctl, (sy_call_t *)msgget,
1449 (sy_call_t *)msgsnd, (sy_call_t *)msgrcv
1453 * Entry point for all MSG calls.
1458 /* XXX actually varargs. */
1459 struct msgsys_args /* {
1470 if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1472 if (uap->which < 0 ||
1473 uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
1475 error = (*msgcalls[uap->which])(td, &uap->a2);
1480 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0)
1483 #ifndef _SYS_SYSPROTO_H_
1484 struct freebsd7_msgctl_args {
1487 struct msqid_ds_old *buf;
1491 freebsd7_msgctl(td, uap)
1493 struct freebsd7_msgctl_args *uap;
1495 struct msqid_ds_old msqold;
1496 struct msqid_ds msqbuf;
1499 DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
1501 if (uap->cmd == IPC_SET) {
1502 error = copyin(uap->buf, &msqold, sizeof(msqold));
1505 ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
1506 CP(msqold, msqbuf, msg_first);
1507 CP(msqold, msqbuf, msg_last);
1508 CP(msqold, msqbuf, msg_cbytes);
1509 CP(msqold, msqbuf, msg_qnum);
1510 CP(msqold, msqbuf, msg_qbytes);
1511 CP(msqold, msqbuf, msg_lspid);
1512 CP(msqold, msqbuf, msg_lrpid);
1513 CP(msqold, msqbuf, msg_stime);
1514 CP(msqold, msqbuf, msg_rtime);
1515 CP(msqold, msqbuf, msg_ctime);
1517 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1520 if (uap->cmd == IPC_STAT) {
1521 bzero(&msqold, sizeof(msqold));
1522 ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
1523 CP(msqbuf, msqold, msg_first);
1524 CP(msqbuf, msqold, msg_last);
1525 CP(msqbuf, msqold, msg_cbytes);
1526 CP(msqbuf, msqold, msg_qnum);
1527 CP(msqbuf, msqold, msg_qbytes);
1528 CP(msqbuf, msqold, msg_lspid);
1529 CP(msqbuf, msqold, msg_lrpid);
1530 CP(msqbuf, msqold, msg_stime);
1531 CP(msqbuf, msqold, msg_rtime);
1532 CP(msqbuf, msqold, msg_ctime);
1533 error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
1540 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||