sysv_msg.c revision 284665
1/*-
2 * Implementation of SVID messages
3 *
4 * Author:  Daniel Boulet
5 *
6 * Copyright 1993 Daniel Boulet and RTMX Inc.
7 *
8 * This system call was implemented by Daniel Boulet under contract from RTMX.
9 *
10 * Redistribution and use in source forms, with and without modification,
11 * are permitted provided that this entire comment appears intact.
12 *
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.
16 *
17 * This software is provided ``AS IS'' without any warranties of any kind.
18 */
19/*-
20 * Copyright (c) 2003-2005 McAfee, Inc.
21 * All rights reserved.
22 *
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
26 * program.
27 *
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
30 * are met:
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.
36 *
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
47 * SUCH DAMAGE.
48 */
49
50#include <sys/cdefs.h>
51__FBSDID("$FreeBSD: stable/10/sys/kern/sysv_msg.c 284665 2015-06-21 06:28:26Z trasz $");
52
53#include "opt_compat.h"
54#include "opt_sysvipc.h"
55
56#include <sys/param.h>
57#include <sys/systm.h>
58#include <sys/sysproto.h>
59#include <sys/kernel.h>
60#include <sys/priv.h>
61#include <sys/proc.h>
62#include <sys/lock.h>
63#include <sys/mutex.h>
64#include <sys/module.h>
65#include <sys/msg.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>
72#include <sys/jail.h>
73
74#include <security/mac/mac_framework.h>
75
76FEATURE(sysv_msg, "System V message queues support");
77
78static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
79
80static int msginit(void);
81static int msgunload(void);
82static int sysvmsg_modload(struct module *, int, void *);
83
84
85#ifdef MSG_DEBUG
86#define DPRINTF(a)	printf a
87#else
88#define DPRINTF(a)	(void)0
89#endif
90
91static void msg_freehdr(struct msg *msghdr);
92
93#ifndef MSGSSZ
94#define MSGSSZ	8		/* Each segment must be 2^N long */
95#endif
96#ifndef MSGSEG
97#define MSGSEG	2048		/* must be less than 32767 */
98#endif
99#define MSGMAX	(MSGSSZ*MSGSEG)
100#ifndef MSGMNB
101#define MSGMNB	2048		/* max # of bytes in a queue */
102#endif
103#ifndef MSGMNI
104#define MSGMNI	40
105#endif
106#ifndef MSGTQL
107#define MSGTQL	40
108#endif
109
110/*
111 * Based on the configuration parameters described in an SVR2 (yes, two)
112 * config(1m) man page.
113 *
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).
119 */
120struct 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 */
128};
129
130/*
131 * macros to convert between msqid_ds's and msqid's.
132 * (specific to this implementation)
133 */
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)
137
138/*
139 * The rest of this file is specific to this particular implementation.
140 */
141
142struct msgmap {
143	short	next;		/* next segment in buffer */
144    				/* -1 -> available */
145    				/* 0..(MSGSEG-1) -> index of next segment */
146};
147
148#define MSG_LOCKED	01000	/* Is this msqid_ds locked? */
149
150static int nfree_msgmaps;	/* # of free map entries */
151static short free_msgmaps;	/* head of linked list of free map entries */
152static struct msg *free_msghdrs;/* list of free msg headers */
153static char *msgpool;		/* MSGMAX byte long msg buffer pool */
154static struct msgmap *msgmaps;	/* MSGSEG msgmap structures */
155static struct msg *msghdrs;	/* MSGTQL msg headers */
156static struct msqid_kernel *msqids;	/* MSGMNI msqid_kernel struct's */
157static struct mtx msq_mtx;	/* global mutex for message queues. */
158
159static 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),
168#endif
169	SYSCALL_INIT_LAST
170};
171
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>
179
180static 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),
189#endif
190	SYSCALL_INIT_LAST
191};
192#endif
193
194static int
195msginit()
196{
197	int i, error;
198
199	TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg);
200	TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz);
201	msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
202	TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni);
203	TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb);
204	TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql);
205
206	msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
207	msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
208	msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
209	msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
210	    M_WAITOK);
211
212	/*
213	 * msginfo.msgssz should be a power of two for efficiency reasons.
214	 * It is also pretty silly if msginfo.msgssz is less than 8
215	 * or greater than about 256 so ...
216	 */
217
218	i = 8;
219	while (i < 1024 && i != msginfo.msgssz)
220		i <<= 1;
221    	if (i != msginfo.msgssz) {
222		DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
223		    msginfo.msgssz));
224		panic("msginfo.msgssz not a small power of 2");
225	}
226
227	if (msginfo.msgseg > 32767) {
228		DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
229		panic("msginfo.msgseg > 32767");
230	}
231
232	for (i = 0; i < msginfo.msgseg; i++) {
233		if (i > 0)
234			msgmaps[i-1].next = i;
235		msgmaps[i].next = -1;	/* implies entry is available */
236	}
237	free_msgmaps = 0;
238	nfree_msgmaps = msginfo.msgseg;
239
240	for (i = 0; i < msginfo.msgtql; i++) {
241		msghdrs[i].msg_type = 0;
242		if (i > 0)
243			msghdrs[i-1].msg_next = &msghdrs[i];
244		msghdrs[i].msg_next = NULL;
245#ifdef MAC
246		mac_sysvmsg_init(&msghdrs[i]);
247#endif
248    	}
249	free_msghdrs = &msghdrs[0];
250
251	for (i = 0; i < msginfo.msgmni; i++) {
252		msqids[i].u.msg_qbytes = 0;	/* implies entry is available */
253		msqids[i].u.msg_perm.seq = 0;	/* reset to a known value */
254		msqids[i].u.msg_perm.mode = 0;
255#ifdef MAC
256		mac_sysvmsq_init(&msqids[i]);
257#endif
258	}
259	mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
260
261	error = syscall_helper_register(msg_syscalls);
262	if (error != 0)
263		return (error);
264#ifdef COMPAT_FREEBSD32
265	error = syscall32_helper_register(msg32_syscalls);
266	if (error != 0)
267		return (error);
268#endif
269	return (0);
270}
271
272static int
273msgunload()
274{
275	struct msqid_kernel *msqkptr;
276	int msqid;
277#ifdef MAC
278	int i;
279#endif
280
281	syscall_helper_unregister(msg_syscalls);
282#ifdef COMPAT_FREEBSD32
283	syscall32_helper_unregister(msg32_syscalls);
284#endif
285
286	for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
287		/*
288		 * Look for an unallocated and unlocked msqid_ds.
289		 * msqid_ds's can be locked by msgsnd or msgrcv while
290		 * they are copying the message in/out.  We can't
291		 * re-use the entry until they release it.
292		 */
293		msqkptr = &msqids[msqid];
294		if (msqkptr->u.msg_qbytes != 0 ||
295		    (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
296			break;
297	}
298	if (msqid != msginfo.msgmni)
299		return (EBUSY);
300
301#ifdef MAC
302	for (i = 0; i < msginfo.msgtql; i++)
303		mac_sysvmsg_destroy(&msghdrs[i]);
304	for (msqid = 0; msqid < msginfo.msgmni; msqid++)
305		mac_sysvmsq_destroy(&msqids[msqid]);
306#endif
307	free(msgpool, M_MSG);
308	free(msgmaps, M_MSG);
309	free(msghdrs, M_MSG);
310	free(msqids, M_MSG);
311	mtx_destroy(&msq_mtx);
312	return (0);
313}
314
315
316static int
317sysvmsg_modload(struct module *module, int cmd, void *arg)
318{
319	int error = 0;
320
321	switch (cmd) {
322	case MOD_LOAD:
323		error = msginit();
324		if (error != 0)
325			msgunload();
326		break;
327	case MOD_UNLOAD:
328		error = msgunload();
329		break;
330	case MOD_SHUTDOWN:
331		break;
332	default:
333		error = EINVAL;
334		break;
335	}
336	return (error);
337}
338
339static moduledata_t sysvmsg_mod = {
340	"sysvmsg",
341	&sysvmsg_modload,
342	NULL
343};
344
345DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
346MODULE_VERSION(sysvmsg, 1);
347
348static void
349msg_freehdr(msghdr)
350	struct msg *msghdr;
351{
352	while (msghdr->msg_ts > 0) {
353		short next;
354		if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
355			panic("msghdr->msg_spot out of range");
356		next = msgmaps[msghdr->msg_spot].next;
357		msgmaps[msghdr->msg_spot].next = free_msgmaps;
358		free_msgmaps = msghdr->msg_spot;
359		nfree_msgmaps++;
360		msghdr->msg_spot = next;
361		if (msghdr->msg_ts >= msginfo.msgssz)
362			msghdr->msg_ts -= msginfo.msgssz;
363		else
364			msghdr->msg_ts = 0;
365	}
366	if (msghdr->msg_spot != -1)
367		panic("msghdr->msg_spot != -1");
368	msghdr->msg_next = free_msghdrs;
369	free_msghdrs = msghdr;
370#ifdef MAC
371	mac_sysvmsg_cleanup(msghdr);
372#endif
373}
374
375#ifndef _SYS_SYSPROTO_H_
376struct msgctl_args {
377	int	msqid;
378	int	cmd;
379	struct	msqid_ds *buf;
380};
381#endif
382int
383sys_msgctl(td, uap)
384	struct thread *td;
385	register struct msgctl_args *uap;
386{
387	int msqid = uap->msqid;
388	int cmd = uap->cmd;
389	struct msqid_ds msqbuf;
390	int error;
391
392	DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
393	if (cmd == IPC_SET &&
394	    (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
395		return (error);
396	error = kern_msgctl(td, msqid, cmd, &msqbuf);
397	if (cmd == IPC_STAT && error == 0)
398		error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
399	return (error);
400}
401
402int
403kern_msgctl(td, msqid, cmd, msqbuf)
404	struct thread *td;
405	int msqid;
406	int cmd;
407	struct msqid_ds *msqbuf;
408{
409	int rval, error, msqix;
410	register struct msqid_kernel *msqkptr;
411
412	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
413		return (ENOSYS);
414
415	msqix = IPCID_TO_IX(msqid);
416
417	if (msqix < 0 || msqix >= msginfo.msgmni) {
418		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
419		    msginfo.msgmni));
420		return (EINVAL);
421	}
422
423	msqkptr = &msqids[msqix];
424
425	mtx_lock(&msq_mtx);
426	if (msqkptr->u.msg_qbytes == 0) {
427		DPRINTF(("no such msqid\n"));
428		error = EINVAL;
429		goto done2;
430	}
431	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
432		DPRINTF(("wrong sequence number\n"));
433		error = EINVAL;
434		goto done2;
435	}
436#ifdef MAC
437	error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
438	if (error != 0)
439		goto done2;
440#endif
441
442	error = 0;
443	rval = 0;
444
445	switch (cmd) {
446
447	case IPC_RMID:
448	{
449		struct msg *msghdr;
450		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
451			goto done2;
452
453#ifdef MAC
454		/*
455		 * Check that the thread has MAC access permissions to
456		 * individual msghdrs.  Note: We need to do this in a
457		 * separate loop because the actual loop alters the
458		 * msq/msghdr info as it progresses, and there is no going
459		 * back if half the way through we discover that the
460		 * thread cannot free a certain msghdr.  The msq will get
461		 * into an inconsistent state.
462		 */
463		for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
464		    msghdr = msghdr->msg_next) {
465			error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
466			if (error != 0)
467				goto done2;
468		}
469#endif
470
471		racct_sub_cred(msqkptr->cred, RACCT_NMSGQ, 1);
472		racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, msqkptr->u.msg_qnum);
473		racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msqkptr->u.msg_cbytes);
474		crfree(msqkptr->cred);
475		msqkptr->cred = NULL;
476
477		/* Free the message headers */
478		msghdr = msqkptr->u.msg_first;
479		while (msghdr != NULL) {
480			struct msg *msghdr_tmp;
481
482			/* Free the segments of each message */
483			msqkptr->u.msg_cbytes -= msghdr->msg_ts;
484			msqkptr->u.msg_qnum--;
485			msghdr_tmp = msghdr;
486			msghdr = msghdr->msg_next;
487			msg_freehdr(msghdr_tmp);
488		}
489
490		if (msqkptr->u.msg_cbytes != 0)
491			panic("msg_cbytes is screwed up");
492		if (msqkptr->u.msg_qnum != 0)
493			panic("msg_qnum is screwed up");
494
495		msqkptr->u.msg_qbytes = 0;	/* Mark it as free */
496
497#ifdef MAC
498		mac_sysvmsq_cleanup(msqkptr);
499#endif
500
501		wakeup(msqkptr);
502	}
503
504		break;
505
506	case IPC_SET:
507		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
508			goto done2;
509		if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
510			error = priv_check(td, PRIV_IPC_MSGSIZE);
511			if (error)
512				goto done2;
513		}
514		if (msqbuf->msg_qbytes > msginfo.msgmnb) {
515			DPRINTF(("can't increase msg_qbytes beyond %d"
516			    "(truncating)\n", msginfo.msgmnb));
517			msqbuf->msg_qbytes = msginfo.msgmnb;	/* silently restrict qbytes to system limit */
518		}
519		if (msqbuf->msg_qbytes == 0) {
520			DPRINTF(("can't reduce msg_qbytes to 0\n"));
521			error = EINVAL;		/* non-standard errno! */
522			goto done2;
523		}
524		msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid;	/* change the owner */
525		msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid;	/* change the owner */
526		msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
527		    (msqbuf->msg_perm.mode & 0777);
528		msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
529		msqkptr->u.msg_ctime = time_second;
530		break;
531
532	case IPC_STAT:
533		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
534			DPRINTF(("requester doesn't have read access\n"));
535			goto done2;
536		}
537		*msqbuf = msqkptr->u;
538		break;
539
540	default:
541		DPRINTF(("invalid command %d\n", cmd));
542		error = EINVAL;
543		goto done2;
544	}
545
546	if (error == 0)
547		td->td_retval[0] = rval;
548done2:
549	mtx_unlock(&msq_mtx);
550	return (error);
551}
552
553#ifndef _SYS_SYSPROTO_H_
554struct msgget_args {
555	key_t	key;
556	int	msgflg;
557};
558#endif
559
560int
561sys_msgget(td, uap)
562	struct thread *td;
563	register struct msgget_args *uap;
564{
565	int msqid, error = 0;
566	int key = uap->key;
567	int msgflg = uap->msgflg;
568	struct ucred *cred = td->td_ucred;
569	register struct msqid_kernel *msqkptr = NULL;
570
571	DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
572
573	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
574		return (ENOSYS);
575
576	mtx_lock(&msq_mtx);
577	if (key != IPC_PRIVATE) {
578		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
579			msqkptr = &msqids[msqid];
580			if (msqkptr->u.msg_qbytes != 0 &&
581			    msqkptr->u.msg_perm.key == key)
582				break;
583		}
584		if (msqid < msginfo.msgmni) {
585			DPRINTF(("found public key\n"));
586			if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
587				DPRINTF(("not exclusive\n"));
588				error = EEXIST;
589				goto done2;
590			}
591			if ((error = ipcperm(td, &msqkptr->u.msg_perm,
592			    msgflg & 0700))) {
593				DPRINTF(("requester doesn't have 0%o access\n",
594				    msgflg & 0700));
595				goto done2;
596			}
597#ifdef MAC
598			error = mac_sysvmsq_check_msqget(cred, msqkptr);
599			if (error != 0)
600				goto done2;
601#endif
602			goto found;
603		}
604	}
605
606	DPRINTF(("need to allocate the msqid_ds\n"));
607	if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
608		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
609			/*
610			 * Look for an unallocated and unlocked msqid_ds.
611			 * msqid_ds's can be locked by msgsnd or msgrcv while
612			 * they are copying the message in/out.  We can't
613			 * re-use the entry until they release it.
614			 */
615			msqkptr = &msqids[msqid];
616			if (msqkptr->u.msg_qbytes == 0 &&
617			    (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
618				break;
619		}
620		if (msqid == msginfo.msgmni) {
621			DPRINTF(("no more msqid_ds's available\n"));
622			error = ENOSPC;
623			goto done2;
624		}
625#ifdef RACCT
626		if (racct_enable) {
627			PROC_LOCK(td->td_proc);
628			error = racct_add(td->td_proc, RACCT_NMSGQ, 1);
629			PROC_UNLOCK(td->td_proc);
630			if (error != 0) {
631				error = ENOSPC;
632				goto done2;
633			}
634		}
635#endif
636		DPRINTF(("msqid %d is available\n", msqid));
637		msqkptr->u.msg_perm.key = key;
638		msqkptr->u.msg_perm.cuid = cred->cr_uid;
639		msqkptr->u.msg_perm.uid = cred->cr_uid;
640		msqkptr->u.msg_perm.cgid = cred->cr_gid;
641		msqkptr->u.msg_perm.gid = cred->cr_gid;
642		msqkptr->u.msg_perm.mode = (msgflg & 0777);
643		msqkptr->cred = crhold(cred);
644		/* Make sure that the returned msqid is unique */
645		msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
646		msqkptr->u.msg_first = NULL;
647		msqkptr->u.msg_last = NULL;
648		msqkptr->u.msg_cbytes = 0;
649		msqkptr->u.msg_qnum = 0;
650		msqkptr->u.msg_qbytes = msginfo.msgmnb;
651		msqkptr->u.msg_lspid = 0;
652		msqkptr->u.msg_lrpid = 0;
653		msqkptr->u.msg_stime = 0;
654		msqkptr->u.msg_rtime = 0;
655		msqkptr->u.msg_ctime = time_second;
656#ifdef MAC
657		mac_sysvmsq_create(cred, msqkptr);
658#endif
659	} else {
660		DPRINTF(("didn't find it and wasn't asked to create it\n"));
661		error = ENOENT;
662		goto done2;
663	}
664
665found:
666	/* Construct the unique msqid */
667	td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
668done2:
669	mtx_unlock(&msq_mtx);
670	return (error);
671}
672
673#ifndef _SYS_SYSPROTO_H_
674struct msgsnd_args {
675	int	msqid;
676	const void	*msgp;
677	size_t	msgsz;
678	int	msgflg;
679};
680#endif
681int
682kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
683	struct thread *td;
684	int msqid;
685	const void *msgp;	/* XXX msgp is actually mtext. */
686	size_t msgsz;
687	int msgflg;
688	long mtype;
689{
690	int msqix, segs_needed, error = 0;
691	register struct msqid_kernel *msqkptr;
692	register struct msg *msghdr;
693	short next;
694#ifdef RACCT
695	size_t saved_msgsz;
696#endif
697
698	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
699		return (ENOSYS);
700
701	mtx_lock(&msq_mtx);
702	msqix = IPCID_TO_IX(msqid);
703
704	if (msqix < 0 || msqix >= msginfo.msgmni) {
705		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
706		    msginfo.msgmni));
707		error = EINVAL;
708		goto done2;
709	}
710
711	msqkptr = &msqids[msqix];
712	if (msqkptr->u.msg_qbytes == 0) {
713		DPRINTF(("no such message queue id\n"));
714		error = EINVAL;
715		goto done2;
716	}
717	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
718		DPRINTF(("wrong sequence number\n"));
719		error = EINVAL;
720		goto done2;
721	}
722
723	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
724		DPRINTF(("requester doesn't have write access\n"));
725		goto done2;
726	}
727
728#ifdef MAC
729	error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
730	if (error != 0)
731		goto done2;
732#endif
733
734#ifdef RACCT
735	if (racct_enable) {
736		PROC_LOCK(td->td_proc);
737		if (racct_add(td->td_proc, RACCT_MSGQQUEUED, 1)) {
738			PROC_UNLOCK(td->td_proc);
739			error = EAGAIN;
740			goto done2;
741		}
742		saved_msgsz = msgsz;
743		if (racct_add(td->td_proc, RACCT_MSGQSIZE, msgsz)) {
744			racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
745			PROC_UNLOCK(td->td_proc);
746			error = EAGAIN;
747			goto done2;
748		}
749		PROC_UNLOCK(td->td_proc);
750	}
751#endif
752
753	segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
754	DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
755	    msginfo.msgssz, segs_needed));
756	for (;;) {
757		int need_more_resources = 0;
758
759		/*
760		 * check msgsz
761		 * (inside this loop in case msg_qbytes changes while we sleep)
762		 */
763
764		if (msgsz > msqkptr->u.msg_qbytes) {
765			DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
766			error = EINVAL;
767			goto done3;
768		}
769
770		if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
771			DPRINTF(("msqid is locked\n"));
772			need_more_resources = 1;
773		}
774		if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
775			DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
776			need_more_resources = 1;
777		}
778		if (segs_needed > nfree_msgmaps) {
779			DPRINTF(("segs_needed > nfree_msgmaps\n"));
780			need_more_resources = 1;
781		}
782		if (free_msghdrs == NULL) {
783			DPRINTF(("no more msghdrs\n"));
784			need_more_resources = 1;
785		}
786
787		if (need_more_resources) {
788			int we_own_it;
789
790			if ((msgflg & IPC_NOWAIT) != 0) {
791				DPRINTF(("need more resources but caller "
792				    "doesn't want to wait\n"));
793				error = EAGAIN;
794				goto done3;
795			}
796
797			if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
798				DPRINTF(("we don't own the msqid_ds\n"));
799				we_own_it = 0;
800			} else {
801				/* Force later arrivals to wait for our
802				   request */
803				DPRINTF(("we own the msqid_ds\n"));
804				msqkptr->u.msg_perm.mode |= MSG_LOCKED;
805				we_own_it = 1;
806			}
807			DPRINTF(("msgsnd:  goodnight\n"));
808			error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
809			    "msgsnd", hz);
810			DPRINTF(("msgsnd:  good morning, error=%d\n", error));
811			if (we_own_it)
812				msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
813			if (error == EWOULDBLOCK) {
814				DPRINTF(("msgsnd:  timed out\n"));
815				continue;
816			}
817			if (error != 0) {
818				DPRINTF(("msgsnd:  interrupted system call\n"));
819				error = EINTR;
820				goto done3;
821			}
822
823			/*
824			 * Make sure that the msq queue still exists
825			 */
826
827			if (msqkptr->u.msg_qbytes == 0) {
828				DPRINTF(("msqid deleted\n"));
829				error = EIDRM;
830				goto done3;
831			}
832
833		} else {
834			DPRINTF(("got all the resources that we need\n"));
835			break;
836		}
837	}
838
839	/*
840	 * We have the resources that we need.
841	 * Make sure!
842	 */
843
844	if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
845		panic("msg_perm.mode & MSG_LOCKED");
846	if (segs_needed > nfree_msgmaps)
847		panic("segs_needed > nfree_msgmaps");
848	if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
849		panic("msgsz + msg_cbytes > msg_qbytes");
850	if (free_msghdrs == NULL)
851		panic("no more msghdrs");
852
853	/*
854	 * Re-lock the msqid_ds in case we page-fault when copying in the
855	 * message
856	 */
857
858	if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
859		panic("msqid_ds is already locked");
860	msqkptr->u.msg_perm.mode |= MSG_LOCKED;
861
862	/*
863	 * Allocate a message header
864	 */
865
866	msghdr = free_msghdrs;
867	free_msghdrs = msghdr->msg_next;
868	msghdr->msg_spot = -1;
869	msghdr->msg_ts = msgsz;
870	msghdr->msg_type = mtype;
871#ifdef MAC
872	/*
873	 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
874	 * immediately?  Or, should it be checked just before the msg is
875	 * enqueued in the msgq (as it is done now)?
876	 */
877	mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
878#endif
879
880	/*
881	 * Allocate space for the message
882	 */
883
884	while (segs_needed > 0) {
885		if (nfree_msgmaps <= 0)
886			panic("not enough msgmaps");
887		if (free_msgmaps == -1)
888			panic("nil free_msgmaps");
889		next = free_msgmaps;
890		if (next <= -1)
891			panic("next too low #1");
892		if (next >= msginfo.msgseg)
893			panic("next out of range #1");
894		DPRINTF(("allocating segment %d to message\n", next));
895		free_msgmaps = msgmaps[next].next;
896		nfree_msgmaps--;
897		msgmaps[next].next = msghdr->msg_spot;
898		msghdr->msg_spot = next;
899		segs_needed--;
900	}
901
902	/*
903	 * Validate the message type
904	 */
905
906	if (msghdr->msg_type < 1) {
907		msg_freehdr(msghdr);
908		msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
909		wakeup(msqkptr);
910		DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
911		error = EINVAL;
912		goto done3;
913	}
914
915	/*
916	 * Copy in the message body
917	 */
918
919	next = msghdr->msg_spot;
920	while (msgsz > 0) {
921		size_t tlen;
922		if (msgsz > msginfo.msgssz)
923			tlen = msginfo.msgssz;
924		else
925			tlen = msgsz;
926		if (next <= -1)
927			panic("next too low #2");
928		if (next >= msginfo.msgseg)
929			panic("next out of range #2");
930		mtx_unlock(&msq_mtx);
931		if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
932		    tlen)) != 0) {
933			mtx_lock(&msq_mtx);
934			DPRINTF(("error %d copying in message segment\n",
935			    error));
936			msg_freehdr(msghdr);
937			msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
938			wakeup(msqkptr);
939			goto done3;
940		}
941		mtx_lock(&msq_mtx);
942		msgsz -= tlen;
943		msgp = (const char *)msgp + tlen;
944		next = msgmaps[next].next;
945	}
946	if (next != -1)
947		panic("didn't use all the msg segments");
948
949	/*
950	 * We've got the message.  Unlock the msqid_ds.
951	 */
952
953	msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
954
955	/*
956	 * Make sure that the msqid_ds is still allocated.
957	 */
958
959	if (msqkptr->u.msg_qbytes == 0) {
960		msg_freehdr(msghdr);
961		wakeup(msqkptr);
962		error = EIDRM;
963		goto done3;
964	}
965
966#ifdef MAC
967	/*
968	 * Note: Since the task/thread allocates the msghdr and usually
969	 * primes it with its own MAC label, for a majority of policies, it
970	 * won't be necessary to check whether the msghdr has access
971	 * permissions to the msgq.  The mac_sysvmsq_check_msqsnd check would
972	 * suffice in that case.  However, this hook may be required where
973	 * individual policies derive a non-identical label for the msghdr
974	 * from the current thread label and may want to check the msghdr
975	 * enqueue permissions, along with read/write permissions to the
976	 * msgq.
977	 */
978	error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
979	if (error != 0) {
980		msg_freehdr(msghdr);
981		wakeup(msqkptr);
982		goto done3;
983	}
984#endif
985
986	/*
987	 * Put the message into the queue
988	 */
989	if (msqkptr->u.msg_first == NULL) {
990		msqkptr->u.msg_first = msghdr;
991		msqkptr->u.msg_last = msghdr;
992	} else {
993		msqkptr->u.msg_last->msg_next = msghdr;
994		msqkptr->u.msg_last = msghdr;
995	}
996	msqkptr->u.msg_last->msg_next = NULL;
997
998	msqkptr->u.msg_cbytes += msghdr->msg_ts;
999	msqkptr->u.msg_qnum++;
1000	msqkptr->u.msg_lspid = td->td_proc->p_pid;
1001	msqkptr->u.msg_stime = time_second;
1002
1003	wakeup(msqkptr);
1004	td->td_retval[0] = 0;
1005done3:
1006#ifdef RACCT
1007	if (racct_enable && error != 0) {
1008		PROC_LOCK(td->td_proc);
1009		racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
1010		racct_sub(td->td_proc, RACCT_MSGQSIZE, saved_msgsz);
1011		PROC_UNLOCK(td->td_proc);
1012	}
1013#endif
1014done2:
1015	mtx_unlock(&msq_mtx);
1016	return (error);
1017}
1018
1019int
1020sys_msgsnd(td, uap)
1021	struct thread *td;
1022	register struct msgsnd_args *uap;
1023{
1024	int error;
1025	long mtype;
1026
1027	DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
1028	    uap->msgsz, uap->msgflg));
1029
1030	if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
1031		DPRINTF(("error %d copying the message type\n", error));
1032		return (error);
1033	}
1034	return (kern_msgsnd(td, uap->msqid,
1035	    (const char *)uap->msgp + sizeof(mtype),
1036	    uap->msgsz, uap->msgflg, mtype));
1037}
1038
1039#ifndef _SYS_SYSPROTO_H_
1040struct msgrcv_args {
1041	int	msqid;
1042	void	*msgp;
1043	size_t	msgsz;
1044	long	msgtyp;
1045	int	msgflg;
1046};
1047#endif
1048int
1049kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
1050	struct thread *td;
1051	int msqid;
1052	void *msgp;	/* XXX msgp is actually mtext. */
1053	size_t msgsz;
1054	long msgtyp;
1055	int msgflg;
1056	long *mtype;
1057{
1058	size_t len;
1059	register struct msqid_kernel *msqkptr;
1060	register struct msg *msghdr;
1061	int msqix, error = 0;
1062	short next;
1063
1064	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1065		return (ENOSYS);
1066
1067	msqix = IPCID_TO_IX(msqid);
1068
1069	if (msqix < 0 || msqix >= msginfo.msgmni) {
1070		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
1071		    msginfo.msgmni));
1072		return (EINVAL);
1073	}
1074
1075	msqkptr = &msqids[msqix];
1076	mtx_lock(&msq_mtx);
1077	if (msqkptr->u.msg_qbytes == 0) {
1078		DPRINTF(("no such message queue id\n"));
1079		error = EINVAL;
1080		goto done2;
1081	}
1082	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1083		DPRINTF(("wrong sequence number\n"));
1084		error = EINVAL;
1085		goto done2;
1086	}
1087
1088	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1089		DPRINTF(("requester doesn't have read access\n"));
1090		goto done2;
1091	}
1092
1093#ifdef MAC
1094	error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
1095	if (error != 0)
1096		goto done2;
1097#endif
1098
1099	msghdr = NULL;
1100	while (msghdr == NULL) {
1101		if (msgtyp == 0) {
1102			msghdr = msqkptr->u.msg_first;
1103			if (msghdr != NULL) {
1104				if (msgsz < msghdr->msg_ts &&
1105				    (msgflg & MSG_NOERROR) == 0) {
1106					DPRINTF(("first message on the queue "
1107					    "is too big (want %zu, got %d)\n",
1108					    msgsz, msghdr->msg_ts));
1109					error = E2BIG;
1110					goto done2;
1111				}
1112#ifdef MAC
1113				error = mac_sysvmsq_check_msgrcv(td->td_ucred,
1114				    msghdr);
1115				if (error != 0)
1116					goto done2;
1117#endif
1118				if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1119					msqkptr->u.msg_first = NULL;
1120					msqkptr->u.msg_last = NULL;
1121				} else {
1122					msqkptr->u.msg_first = msghdr->msg_next;
1123					if (msqkptr->u.msg_first == NULL)
1124						panic("msg_first/last screwed up #1");
1125				}
1126			}
1127		} else {
1128			struct msg *previous;
1129			struct msg **prev;
1130
1131			previous = NULL;
1132			prev = &(msqkptr->u.msg_first);
1133			while ((msghdr = *prev) != NULL) {
1134				/*
1135				 * Is this message's type an exact match or is
1136				 * this message's type less than or equal to
1137				 * the absolute value of a negative msgtyp?
1138				 * Note that the second half of this test can
1139				 * NEVER be true if msgtyp is positive since
1140				 * msg_type is always positive!
1141				 */
1142
1143				if (msgtyp == msghdr->msg_type ||
1144				    msghdr->msg_type <= -msgtyp) {
1145					DPRINTF(("found message type %ld, "
1146					    "requested %ld\n",
1147					    msghdr->msg_type, msgtyp));
1148					if (msgsz < msghdr->msg_ts &&
1149					    (msgflg & MSG_NOERROR) == 0) {
1150						DPRINTF(("requested message "
1151						    "on the queue is too big "
1152						    "(want %zu, got %hu)\n",
1153						    msgsz, msghdr->msg_ts));
1154						error = E2BIG;
1155						goto done2;
1156					}
1157#ifdef MAC
1158					error = mac_sysvmsq_check_msgrcv(
1159					    td->td_ucred, msghdr);
1160					if (error != 0)
1161						goto done2;
1162#endif
1163					*prev = msghdr->msg_next;
1164					if (msghdr == msqkptr->u.msg_last) {
1165						if (previous == NULL) {
1166							if (prev !=
1167							    &msqkptr->u.msg_first)
1168								panic("msg_first/last screwed up #2");
1169							msqkptr->u.msg_first =
1170							    NULL;
1171							msqkptr->u.msg_last =
1172							    NULL;
1173						} else {
1174							if (prev ==
1175							    &msqkptr->u.msg_first)
1176								panic("msg_first/last screwed up #3");
1177							msqkptr->u.msg_last =
1178							    previous;
1179						}
1180					}
1181					break;
1182				}
1183				previous = msghdr;
1184				prev = &(msghdr->msg_next);
1185			}
1186		}
1187
1188		/*
1189		 * We've either extracted the msghdr for the appropriate
1190		 * message or there isn't one.
1191		 * If there is one then bail out of this loop.
1192		 */
1193
1194		if (msghdr != NULL)
1195			break;
1196
1197		/*
1198		 * Hmph!  No message found.  Does the user want to wait?
1199		 */
1200
1201		if ((msgflg & IPC_NOWAIT) != 0) {
1202			DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1203			    msgtyp));
1204			/* The SVID says to return ENOMSG. */
1205			error = ENOMSG;
1206			goto done2;
1207		}
1208
1209		/*
1210		 * Wait for something to happen
1211		 */
1212
1213		DPRINTF(("msgrcv:  goodnight\n"));
1214		error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1215		    "msgrcv", 0);
1216		DPRINTF(("msgrcv:  good morning (error=%d)\n", error));
1217
1218		if (error != 0) {
1219			DPRINTF(("msgrcv:  interrupted system call\n"));
1220			error = EINTR;
1221			goto done2;
1222		}
1223
1224		/*
1225		 * Make sure that the msq queue still exists
1226		 */
1227
1228		if (msqkptr->u.msg_qbytes == 0 ||
1229		    msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1230			DPRINTF(("msqid deleted\n"));
1231			error = EIDRM;
1232			goto done2;
1233		}
1234	}
1235
1236	/*
1237	 * Return the message to the user.
1238	 *
1239	 * First, do the bookkeeping (before we risk being interrupted).
1240	 */
1241
1242	msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1243	msqkptr->u.msg_qnum--;
1244	msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1245	msqkptr->u.msg_rtime = time_second;
1246
1247	racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, 1);
1248	racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msghdr->msg_ts);
1249
1250	/*
1251	 * Make msgsz the actual amount that we'll be returning.
1252	 * Note that this effectively truncates the message if it is too long
1253	 * (since msgsz is never increased).
1254	 */
1255
1256	DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1257	    msghdr->msg_ts));
1258	if (msgsz > msghdr->msg_ts)
1259		msgsz = msghdr->msg_ts;
1260	*mtype = msghdr->msg_type;
1261
1262	/*
1263	 * Return the segments to the user
1264	 */
1265
1266	next = msghdr->msg_spot;
1267	for (len = 0; len < msgsz; len += msginfo.msgssz) {
1268		size_t tlen;
1269
1270		if (msgsz - len > msginfo.msgssz)
1271			tlen = msginfo.msgssz;
1272		else
1273			tlen = msgsz - len;
1274		if (next <= -1)
1275			panic("next too low #3");
1276		if (next >= msginfo.msgseg)
1277			panic("next out of range #3");
1278		mtx_unlock(&msq_mtx);
1279		error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1280		mtx_lock(&msq_mtx);
1281		if (error != 0) {
1282			DPRINTF(("error (%d) copying out message segment\n",
1283			    error));
1284			msg_freehdr(msghdr);
1285			wakeup(msqkptr);
1286			goto done2;
1287		}
1288		msgp = (char *)msgp + tlen;
1289		next = msgmaps[next].next;
1290	}
1291
1292	/*
1293	 * Done, return the actual number of bytes copied out.
1294	 */
1295
1296	msg_freehdr(msghdr);
1297	wakeup(msqkptr);
1298	td->td_retval[0] = msgsz;
1299done2:
1300	mtx_unlock(&msq_mtx);
1301	return (error);
1302}
1303
1304int
1305sys_msgrcv(td, uap)
1306	struct thread *td;
1307	register struct msgrcv_args *uap;
1308{
1309	int error;
1310	long mtype;
1311
1312	DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1313	    uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1314
1315	if ((error = kern_msgrcv(td, uap->msqid,
1316	    (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1317	    uap->msgtyp, uap->msgflg, &mtype)) != 0)
1318		return (error);
1319	if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1320		DPRINTF(("error %d copying the message type\n", error));
1321	return (error);
1322}
1323
1324static int
1325sysctl_msqids(SYSCTL_HANDLER_ARGS)
1326{
1327
1328	return (SYSCTL_OUT(req, msqids,
1329	    sizeof(struct msqid_kernel) * msginfo.msgmni));
1330}
1331
1332SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1333    "Maximum message size");
1334SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1335    "Number of message queue identifiers");
1336SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1337    "Maximum number of bytes in a queue");
1338SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1339    "Maximum number of messages in the system");
1340SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1341    "Size of a message segment");
1342SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1343    "Number of message segments");
1344SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLTYPE_OPAQUE | CTLFLAG_RD,
1345    NULL, 0, sysctl_msqids, "", "Message queue IDs");
1346
1347#ifdef COMPAT_FREEBSD32
1348int
1349freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap)
1350{
1351
1352#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1353    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1354	switch (uap->which) {
1355	case 0:
1356		return (freebsd7_freebsd32_msgctl(td,
1357		    (struct freebsd7_freebsd32_msgctl_args *)&uap->a2));
1358	case 2:
1359		return (freebsd32_msgsnd(td,
1360		    (struct freebsd32_msgsnd_args *)&uap->a2));
1361	case 3:
1362		return (freebsd32_msgrcv(td,
1363		    (struct freebsd32_msgrcv_args *)&uap->a2));
1364	default:
1365		return (sys_msgsys(td, (struct msgsys_args *)uap));
1366	}
1367#else
1368	return (nosys(td, NULL));
1369#endif
1370}
1371
1372#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1373    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1374int
1375freebsd7_freebsd32_msgctl(struct thread *td,
1376    struct freebsd7_freebsd32_msgctl_args *uap)
1377{
1378	struct msqid_ds msqbuf;
1379	struct msqid_ds32_old msqbuf32;
1380	int error;
1381
1382	if (uap->cmd == IPC_SET) {
1383		error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1384		if (error)
1385			return (error);
1386		freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1387		PTRIN_CP(msqbuf32, msqbuf, msg_first);
1388		PTRIN_CP(msqbuf32, msqbuf, msg_last);
1389		CP(msqbuf32, msqbuf, msg_cbytes);
1390		CP(msqbuf32, msqbuf, msg_qnum);
1391		CP(msqbuf32, msqbuf, msg_qbytes);
1392		CP(msqbuf32, msqbuf, msg_lspid);
1393		CP(msqbuf32, msqbuf, msg_lrpid);
1394		CP(msqbuf32, msqbuf, msg_stime);
1395		CP(msqbuf32, msqbuf, msg_rtime);
1396		CP(msqbuf32, msqbuf, msg_ctime);
1397	}
1398	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1399	if (error)
1400		return (error);
1401	if (uap->cmd == IPC_STAT) {
1402		bzero(&msqbuf32, sizeof(msqbuf32));
1403		freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1404		PTROUT_CP(msqbuf, msqbuf32, msg_first);
1405		PTROUT_CP(msqbuf, msqbuf32, msg_last);
1406		CP(msqbuf, msqbuf32, msg_cbytes);
1407		CP(msqbuf, msqbuf32, msg_qnum);
1408		CP(msqbuf, msqbuf32, msg_qbytes);
1409		CP(msqbuf, msqbuf32, msg_lspid);
1410		CP(msqbuf, msqbuf32, msg_lrpid);
1411		CP(msqbuf, msqbuf32, msg_stime);
1412		CP(msqbuf, msqbuf32, msg_rtime);
1413		CP(msqbuf, msqbuf32, msg_ctime);
1414		error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1415	}
1416	return (error);
1417}
1418#endif
1419
1420int
1421freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap)
1422{
1423	struct msqid_ds msqbuf;
1424	struct msqid_ds32 msqbuf32;
1425	int error;
1426
1427	if (uap->cmd == IPC_SET) {
1428		error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1429		if (error)
1430			return (error);
1431		freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1432		PTRIN_CP(msqbuf32, msqbuf, msg_first);
1433		PTRIN_CP(msqbuf32, msqbuf, msg_last);
1434		CP(msqbuf32, msqbuf, msg_cbytes);
1435		CP(msqbuf32, msqbuf, msg_qnum);
1436		CP(msqbuf32, msqbuf, msg_qbytes);
1437		CP(msqbuf32, msqbuf, msg_lspid);
1438		CP(msqbuf32, msqbuf, msg_lrpid);
1439		CP(msqbuf32, msqbuf, msg_stime);
1440		CP(msqbuf32, msqbuf, msg_rtime);
1441		CP(msqbuf32, msqbuf, msg_ctime);
1442	}
1443	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1444	if (error)
1445		return (error);
1446	if (uap->cmd == IPC_STAT) {
1447		freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1448		PTROUT_CP(msqbuf, msqbuf32, msg_first);
1449		PTROUT_CP(msqbuf, msqbuf32, msg_last);
1450		CP(msqbuf, msqbuf32, msg_cbytes);
1451		CP(msqbuf, msqbuf32, msg_qnum);
1452		CP(msqbuf, msqbuf32, msg_qbytes);
1453		CP(msqbuf, msqbuf32, msg_lspid);
1454		CP(msqbuf, msqbuf32, msg_lrpid);
1455		CP(msqbuf, msqbuf32, msg_stime);
1456		CP(msqbuf, msqbuf32, msg_rtime);
1457		CP(msqbuf, msqbuf32, msg_ctime);
1458		error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1459	}
1460	return (error);
1461}
1462
1463int
1464freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap)
1465{
1466	const void *msgp;
1467	long mtype;
1468	int32_t mtype32;
1469	int error;
1470
1471	msgp = PTRIN(uap->msgp);
1472	if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0)
1473		return (error);
1474	mtype = mtype32;
1475	return (kern_msgsnd(td, uap->msqid,
1476	    (const char *)msgp + sizeof(mtype32),
1477	    uap->msgsz, uap->msgflg, mtype));
1478}
1479
1480int
1481freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap)
1482{
1483	void *msgp;
1484	long mtype;
1485	int32_t mtype32;
1486	int error;
1487
1488	msgp = PTRIN(uap->msgp);
1489	if ((error = kern_msgrcv(td, uap->msqid,
1490	    (char *)msgp + sizeof(mtype32), uap->msgsz,
1491	    uap->msgtyp, uap->msgflg, &mtype)) != 0)
1492		return (error);
1493	mtype32 = (int32_t)mtype;
1494	return (copyout(&mtype32, msgp, sizeof(mtype32)));
1495}
1496#endif
1497
1498#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1499    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1500
1501/* XXX casting to (sy_call_t *) is bogus, as usual. */
1502static sy_call_t *msgcalls[] = {
1503	(sy_call_t *)freebsd7_msgctl, (sy_call_t *)sys_msgget,
1504	(sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
1505};
1506
1507/*
1508 * Entry point for all MSG calls.
1509 */
1510int
1511sys_msgsys(td, uap)
1512	struct thread *td;
1513	/* XXX actually varargs. */
1514	struct msgsys_args /* {
1515		int	which;
1516		int	a2;
1517		int	a3;
1518		int	a4;
1519		int	a5;
1520		int	a6;
1521	} */ *uap;
1522{
1523	int error;
1524
1525	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1526		return (ENOSYS);
1527	if (uap->which < 0 ||
1528	    uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
1529		return (EINVAL);
1530	error = (*msgcalls[uap->which])(td, &uap->a2);
1531	return (error);
1532}
1533
1534#ifndef CP
1535#define CP(src, dst, fld)	do { (dst).fld = (src).fld; } while (0)
1536#endif
1537
1538#ifndef _SYS_SYSPROTO_H_
1539struct freebsd7_msgctl_args {
1540	int	msqid;
1541	int	cmd;
1542	struct	msqid_ds_old *buf;
1543};
1544#endif
1545int
1546freebsd7_msgctl(td, uap)
1547	struct thread *td;
1548	struct freebsd7_msgctl_args *uap;
1549{
1550	struct msqid_ds_old msqold;
1551	struct msqid_ds msqbuf;
1552	int error;
1553
1554	DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
1555	    uap->buf));
1556	if (uap->cmd == IPC_SET) {
1557		error = copyin(uap->buf, &msqold, sizeof(msqold));
1558		if (error)
1559			return (error);
1560		ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
1561		CP(msqold, msqbuf, msg_first);
1562		CP(msqold, msqbuf, msg_last);
1563		CP(msqold, msqbuf, msg_cbytes);
1564		CP(msqold, msqbuf, msg_qnum);
1565		CP(msqold, msqbuf, msg_qbytes);
1566		CP(msqold, msqbuf, msg_lspid);
1567		CP(msqold, msqbuf, msg_lrpid);
1568		CP(msqold, msqbuf, msg_stime);
1569		CP(msqold, msqbuf, msg_rtime);
1570		CP(msqold, msqbuf, msg_ctime);
1571	}
1572	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1573	if (error)
1574		return (error);
1575	if (uap->cmd == IPC_STAT) {
1576		bzero(&msqold, sizeof(msqold));
1577		ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
1578		CP(msqbuf, msqold, msg_first);
1579		CP(msqbuf, msqold, msg_last);
1580		CP(msqbuf, msqold, msg_cbytes);
1581		CP(msqbuf, msqold, msg_qnum);
1582		CP(msqbuf, msqold, msg_qbytes);
1583		CP(msqbuf, msqold, msg_lspid);
1584		CP(msqbuf, msqold, msg_lrpid);
1585		CP(msqbuf, msqold, msg_stime);
1586		CP(msqbuf, msqold, msg_rtime);
1587		CP(msqbuf, msqold, msg_ctime);
1588		error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
1589	}
1590	return (error);
1591}
1592
1593#undef CP
1594
1595#endif	/* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1596	   COMPAT_FREEBSD7 */
1597