xref: /freebsd/sys/kern/sysv_msg.c (revision 830940567b49bb0c08dfaed40418999e76616909)
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("$FreeBSD$");
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/syscall.h>
67 #include <sys/syscallsubr.h>
68 #include <sys/sysent.h>
69 #include <sys/sysctl.h>
70 #include <sys/malloc.h>
71 #include <sys/jail.h>
72 
73 #include <security/mac/mac_framework.h>
74 
75 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
76 
77 static void msginit(void);
78 static int msgunload(void);
79 static int sysvmsg_modload(struct module *, int, void *);
80 
81 #ifdef MSG_DEBUG
82 #define DPRINTF(a)	printf a
83 #else
84 #define DPRINTF(a)	(void)0
85 #endif
86 
87 static void msg_freehdr(struct msg *msghdr);
88 
89 #ifndef MSGSSZ
90 #define MSGSSZ	8		/* Each segment must be 2^N long */
91 #endif
92 #ifndef MSGSEG
93 #define MSGSEG	2048		/* must be less than 32767 */
94 #endif
95 #define MSGMAX	(MSGSSZ*MSGSEG)
96 #ifndef MSGMNB
97 #define MSGMNB	2048		/* max # of bytes in a queue */
98 #endif
99 #ifndef MSGMNI
100 #define MSGMNI	40
101 #endif
102 #ifndef MSGTQL
103 #define MSGTQL	40
104 #endif
105 
106 /*
107  * Based on the configuration parameters described in an SVR2 (yes, two)
108  * config(1m) man page.
109  *
110  * Each message is broken up and stored in segments that are msgssz bytes
111  * long.  For efficiency reasons, this should be a power of two.  Also,
112  * it doesn't make sense if it is less than 8 or greater than about 256.
113  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
114  * two between 8 and 1024 inclusive (and panic's if it isn't).
115  */
116 struct msginfo msginfo = {
117                 MSGMAX,         /* max chars in a message */
118                 MSGMNI,         /* # of message queue identifiers */
119                 MSGMNB,         /* max chars in a queue */
120                 MSGTQL,         /* max messages in system */
121                 MSGSSZ,         /* size of a message segment */
122                 		/* (must be small power of 2 greater than 4) */
123                 MSGSEG          /* number of message segments */
124 };
125 
126 /*
127  * macros to convert between msqid_ds's and msqid's.
128  * (specific to this implementation)
129  */
130 #define MSQID(ix,ds)	((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
131 #define MSQID_IX(id)	((id) & 0xffff)
132 #define MSQID_SEQ(id)	(((id) >> 16) & 0xffff)
133 
134 /*
135  * The rest of this file is specific to this particular implementation.
136  */
137 
138 struct msgmap {
139 	short	next;		/* next segment in buffer */
140     				/* -1 -> available */
141     				/* 0..(MSGSEG-1) -> index of next segment */
142 };
143 
144 #define MSG_LOCKED	01000	/* Is this msqid_ds locked? */
145 
146 static int nfree_msgmaps;	/* # of free map entries */
147 static short free_msgmaps;	/* head of linked list of free map entries */
148 static struct msg *free_msghdrs;/* list of free msg headers */
149 static char *msgpool;		/* MSGMAX byte long msg buffer pool */
150 static struct msgmap *msgmaps;	/* MSGSEG msgmap structures */
151 static struct msg *msghdrs;	/* MSGTQL msg headers */
152 static struct msqid_kernel *msqids;	/* MSGMNI msqid_kernel struct's */
153 static struct mtx msq_mtx;	/* global mutex for message queues. */
154 
155 static void
156 msginit()
157 {
158 	register int i;
159 
160 	TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg);
161 	TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz);
162 	msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
163 	TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni);
164 	TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb);
165 	TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql);
166 
167 	msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
168 	if (msgpool == NULL)
169 		panic("msgpool is NULL");
170 	msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
171 	if (msgmaps == NULL)
172 		panic("msgmaps is NULL");
173 	msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
174 	if (msghdrs == NULL)
175 		panic("msghdrs is NULL");
176 	msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
177 	    M_WAITOK);
178 	if (msqids == NULL)
179 		panic("msqids is NULL");
180 
181 	/*
182 	 * msginfo.msgssz should be a power of two for efficiency reasons.
183 	 * It is also pretty silly if msginfo.msgssz is less than 8
184 	 * or greater than about 256 so ...
185 	 */
186 
187 	i = 8;
188 	while (i < 1024 && i != msginfo.msgssz)
189 		i <<= 1;
190     	if (i != msginfo.msgssz) {
191 		DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
192 		    msginfo.msgssz));
193 		panic("msginfo.msgssz not a small power of 2");
194 	}
195 
196 	if (msginfo.msgseg > 32767) {
197 		DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
198 		panic("msginfo.msgseg > 32767");
199 	}
200 
201 	if (msgmaps == NULL)
202 		panic("msgmaps is NULL");
203 
204 	for (i = 0; i < msginfo.msgseg; i++) {
205 		if (i > 0)
206 			msgmaps[i-1].next = i;
207 		msgmaps[i].next = -1;	/* implies entry is available */
208 	}
209 	free_msgmaps = 0;
210 	nfree_msgmaps = msginfo.msgseg;
211 
212 	if (msghdrs == NULL)
213 		panic("msghdrs is NULL");
214 
215 	for (i = 0; i < msginfo.msgtql; i++) {
216 		msghdrs[i].msg_type = 0;
217 		if (i > 0)
218 			msghdrs[i-1].msg_next = &msghdrs[i];
219 		msghdrs[i].msg_next = NULL;
220 #ifdef MAC
221 		mac_sysvmsg_init(&msghdrs[i]);
222 #endif
223     	}
224 	free_msghdrs = &msghdrs[0];
225 
226 	if (msqids == NULL)
227 		panic("msqids is NULL");
228 
229 	for (i = 0; i < msginfo.msgmni; i++) {
230 		msqids[i].u.msg_qbytes = 0;	/* implies entry is available */
231 		msqids[i].u.msg_perm.seq = 0;	/* reset to a known value */
232 		msqids[i].u.msg_perm.mode = 0;
233 #ifdef MAC
234 		mac_sysvmsq_init(&msqids[i]);
235 #endif
236 	}
237 	mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
238 }
239 
240 static int
241 msgunload()
242 {
243 	struct msqid_kernel *msqkptr;
244 	int msqid;
245 #ifdef MAC
246 	int i;
247 #endif
248 
249 	for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
250 		/*
251 		 * Look for an unallocated and unlocked msqid_ds.
252 		 * msqid_ds's can be locked by msgsnd or msgrcv while
253 		 * they are copying the message in/out.  We can't
254 		 * re-use the entry until they release it.
255 		 */
256 		msqkptr = &msqids[msqid];
257 		if (msqkptr->u.msg_qbytes != 0 ||
258 		    (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
259 			break;
260 	}
261 	if (msqid != msginfo.msgmni)
262 		return (EBUSY);
263 
264 #ifdef MAC
265 	for (i = 0; i < msginfo.msgtql; i++)
266 		mac_sysvmsg_destroy(&msghdrs[i]);
267 	for (msqid = 0; msqid < msginfo.msgmni; msqid++)
268 		mac_sysvmsq_destroy(&msqids[msqid]);
269 #endif
270 	free(msgpool, M_MSG);
271 	free(msgmaps, M_MSG);
272 	free(msghdrs, M_MSG);
273 	free(msqids, M_MSG);
274 	mtx_destroy(&msq_mtx);
275 	return (0);
276 }
277 
278 
279 static int
280 sysvmsg_modload(struct module *module, int cmd, void *arg)
281 {
282 	int error = 0;
283 
284 	switch (cmd) {
285 	case MOD_LOAD:
286 		msginit();
287 		break;
288 	case MOD_UNLOAD:
289 		error = msgunload();
290 		break;
291 	case MOD_SHUTDOWN:
292 		break;
293 	default:
294 		error = EINVAL;
295 		break;
296 	}
297 	return (error);
298 }
299 
300 static moduledata_t sysvmsg_mod = {
301 	"sysvmsg",
302 	&sysvmsg_modload,
303 	NULL
304 };
305 
306 SYSCALL_MODULE_HELPER(msgctl);
307 SYSCALL_MODULE_HELPER(msgget);
308 SYSCALL_MODULE_HELPER(msgsnd);
309 SYSCALL_MODULE_HELPER(msgrcv);
310 
311 DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
312 MODULE_VERSION(sysvmsg, 1);
313 
314 static void
315 msg_freehdr(msghdr)
316 	struct msg *msghdr;
317 {
318 	while (msghdr->msg_ts > 0) {
319 		short next;
320 		if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
321 			panic("msghdr->msg_spot out of range");
322 		next = msgmaps[msghdr->msg_spot].next;
323 		msgmaps[msghdr->msg_spot].next = free_msgmaps;
324 		free_msgmaps = msghdr->msg_spot;
325 		nfree_msgmaps++;
326 		msghdr->msg_spot = next;
327 		if (msghdr->msg_ts >= msginfo.msgssz)
328 			msghdr->msg_ts -= msginfo.msgssz;
329 		else
330 			msghdr->msg_ts = 0;
331 	}
332 	if (msghdr->msg_spot != -1)
333 		panic("msghdr->msg_spot != -1");
334 	msghdr->msg_next = free_msghdrs;
335 	free_msghdrs = msghdr;
336 #ifdef MAC
337 	mac_sysvmsg_cleanup(msghdr);
338 #endif
339 }
340 
341 #ifndef _SYS_SYSPROTO_H_
342 struct msgctl_args {
343 	int	msqid;
344 	int	cmd;
345 	struct	msqid_ds *buf;
346 };
347 #endif
348 int
349 msgctl(td, uap)
350 	struct thread *td;
351 	register struct msgctl_args *uap;
352 {
353 	int msqid = uap->msqid;
354 	int cmd = uap->cmd;
355 	struct msqid_ds msqbuf;
356 	int error;
357 
358 	DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
359 	if (cmd == IPC_SET &&
360 	    (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
361 		return (error);
362 	error = kern_msgctl(td, msqid, cmd, &msqbuf);
363 	if (cmd == IPC_STAT && error == 0)
364 		error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
365 	return (error);
366 }
367 
368 int
369 kern_msgctl(td, msqid, cmd, msqbuf)
370 	struct thread *td;
371 	int msqid;
372 	int cmd;
373 	struct msqid_ds *msqbuf;
374 {
375 	int rval, error, msqix;
376 	register struct msqid_kernel *msqkptr;
377 
378 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
379 		return (ENOSYS);
380 
381 	msqix = IPCID_TO_IX(msqid);
382 
383 	if (msqix < 0 || msqix >= msginfo.msgmni) {
384 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
385 		    msginfo.msgmni));
386 		return (EINVAL);
387 	}
388 
389 	msqkptr = &msqids[msqix];
390 
391 	mtx_lock(&msq_mtx);
392 	if (msqkptr->u.msg_qbytes == 0) {
393 		DPRINTF(("no such msqid\n"));
394 		error = EINVAL;
395 		goto done2;
396 	}
397 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
398 		DPRINTF(("wrong sequence number\n"));
399 		error = EINVAL;
400 		goto done2;
401 	}
402 #ifdef MAC
403 	error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
404 	if (error != 0)
405 		goto done2;
406 #endif
407 
408 	error = 0;
409 	rval = 0;
410 
411 	switch (cmd) {
412 
413 	case IPC_RMID:
414 	{
415 		struct msg *msghdr;
416 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
417 			goto done2;
418 
419 #ifdef MAC
420 		/*
421 		 * Check that the thread has MAC access permissions to
422 		 * individual msghdrs.  Note: We need to do this in a
423 		 * separate loop because the actual loop alters the
424 		 * msq/msghdr info as it progresses, and there is no going
425 		 * back if half the way through we discover that the
426 		 * thread cannot free a certain msghdr.  The msq will get
427 		 * into an inconsistent state.
428 		 */
429 		for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
430 		    msghdr = msghdr->msg_next) {
431 			error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
432 			if (error != 0)
433 				goto done2;
434 		}
435 #endif
436 
437 		/* Free the message headers */
438 		msghdr = msqkptr->u.msg_first;
439 		while (msghdr != NULL) {
440 			struct msg *msghdr_tmp;
441 
442 			/* Free the segments of each message */
443 			msqkptr->u.msg_cbytes -= msghdr->msg_ts;
444 			msqkptr->u.msg_qnum--;
445 			msghdr_tmp = msghdr;
446 			msghdr = msghdr->msg_next;
447 			msg_freehdr(msghdr_tmp);
448 		}
449 
450 		if (msqkptr->u.msg_cbytes != 0)
451 			panic("msg_cbytes is screwed up");
452 		if (msqkptr->u.msg_qnum != 0)
453 			panic("msg_qnum is screwed up");
454 
455 		msqkptr->u.msg_qbytes = 0;	/* Mark it as free */
456 
457 #ifdef MAC
458 		mac_sysvmsq_cleanup(msqkptr);
459 #endif
460 
461 		wakeup(msqkptr);
462 	}
463 
464 		break;
465 
466 	case IPC_SET:
467 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
468 			goto done2;
469 		if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
470 			error = priv_check(td, PRIV_IPC_MSGSIZE);
471 			if (error)
472 				goto done2;
473 		}
474 		if (msqbuf->msg_qbytes > msginfo.msgmnb) {
475 			DPRINTF(("can't increase msg_qbytes beyond %d"
476 			    "(truncating)\n", msginfo.msgmnb));
477 			msqbuf->msg_qbytes = msginfo.msgmnb;	/* silently restrict qbytes to system limit */
478 		}
479 		if (msqbuf->msg_qbytes == 0) {
480 			DPRINTF(("can't reduce msg_qbytes to 0\n"));
481 			error = EINVAL;		/* non-standard errno! */
482 			goto done2;
483 		}
484 		msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid;	/* change the owner */
485 		msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid;	/* change the owner */
486 		msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
487 		    (msqbuf->msg_perm.mode & 0777);
488 		msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
489 		msqkptr->u.msg_ctime = time_second;
490 		break;
491 
492 	case IPC_STAT:
493 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
494 			DPRINTF(("requester doesn't have read access\n"));
495 			goto done2;
496 		}
497 		*msqbuf = msqkptr->u;
498 		break;
499 
500 	default:
501 		DPRINTF(("invalid command %d\n", cmd));
502 		error = EINVAL;
503 		goto done2;
504 	}
505 
506 	if (error == 0)
507 		td->td_retval[0] = rval;
508 done2:
509 	mtx_unlock(&msq_mtx);
510 	return (error);
511 }
512 
513 #ifndef _SYS_SYSPROTO_H_
514 struct msgget_args {
515 	key_t	key;
516 	int	msgflg;
517 };
518 #endif
519 int
520 msgget(td, uap)
521 	struct thread *td;
522 	register struct msgget_args *uap;
523 {
524 	int msqid, error = 0;
525 	int key = uap->key;
526 	int msgflg = uap->msgflg;
527 	struct ucred *cred = td->td_ucred;
528 	register struct msqid_kernel *msqkptr = NULL;
529 
530 	DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
531 
532 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
533 		return (ENOSYS);
534 
535 	mtx_lock(&msq_mtx);
536 	if (key != IPC_PRIVATE) {
537 		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
538 			msqkptr = &msqids[msqid];
539 			if (msqkptr->u.msg_qbytes != 0 &&
540 			    msqkptr->u.msg_perm.key == key)
541 				break;
542 		}
543 		if (msqid < msginfo.msgmni) {
544 			DPRINTF(("found public key\n"));
545 			if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
546 				DPRINTF(("not exclusive\n"));
547 				error = EEXIST;
548 				goto done2;
549 			}
550 			if ((error = ipcperm(td, &msqkptr->u.msg_perm,
551 			    msgflg & 0700))) {
552 				DPRINTF(("requester doesn't have 0%o access\n",
553 				    msgflg & 0700));
554 				goto done2;
555 			}
556 #ifdef MAC
557 			error = mac_sysvmsq_check_msqget(cred, msqkptr);
558 			if (error != 0)
559 				goto done2;
560 #endif
561 			goto found;
562 		}
563 	}
564 
565 	DPRINTF(("need to allocate the msqid_ds\n"));
566 	if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
567 		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
568 			/*
569 			 * Look for an unallocated and unlocked msqid_ds.
570 			 * msqid_ds's can be locked by msgsnd or msgrcv while
571 			 * they are copying the message in/out.  We can't
572 			 * re-use the entry until they release it.
573 			 */
574 			msqkptr = &msqids[msqid];
575 			if (msqkptr->u.msg_qbytes == 0 &&
576 			    (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
577 				break;
578 		}
579 		if (msqid == msginfo.msgmni) {
580 			DPRINTF(("no more msqid_ds's available\n"));
581 			error = ENOSPC;
582 			goto done2;
583 		}
584 		DPRINTF(("msqid %d is available\n", msqid));
585 		msqkptr->u.msg_perm.key = key;
586 		msqkptr->u.msg_perm.cuid = cred->cr_uid;
587 		msqkptr->u.msg_perm.uid = cred->cr_uid;
588 		msqkptr->u.msg_perm.cgid = cred->cr_gid;
589 		msqkptr->u.msg_perm.gid = cred->cr_gid;
590 		msqkptr->u.msg_perm.mode = (msgflg & 0777);
591 		/* Make sure that the returned msqid is unique */
592 		msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
593 		msqkptr->u.msg_first = NULL;
594 		msqkptr->u.msg_last = NULL;
595 		msqkptr->u.msg_cbytes = 0;
596 		msqkptr->u.msg_qnum = 0;
597 		msqkptr->u.msg_qbytes = msginfo.msgmnb;
598 		msqkptr->u.msg_lspid = 0;
599 		msqkptr->u.msg_lrpid = 0;
600 		msqkptr->u.msg_stime = 0;
601 		msqkptr->u.msg_rtime = 0;
602 		msqkptr->u.msg_ctime = time_second;
603 #ifdef MAC
604 		mac_sysvmsq_create(cred, msqkptr);
605 #endif
606 	} else {
607 		DPRINTF(("didn't find it and wasn't asked to create it\n"));
608 		error = ENOENT;
609 		goto done2;
610 	}
611 
612 found:
613 	/* Construct the unique msqid */
614 	td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
615 done2:
616 	mtx_unlock(&msq_mtx);
617 	return (error);
618 }
619 
620 #ifndef _SYS_SYSPROTO_H_
621 struct msgsnd_args {
622 	int	msqid;
623 	const void	*msgp;
624 	size_t	msgsz;
625 	int	msgflg;
626 };
627 #endif
628 int
629 kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
630 	struct thread *td;
631 	int msqid;
632 	const void *msgp;	/* XXX msgp is actually mtext. */
633 	size_t msgsz;
634 	int msgflg;
635 	long mtype;
636 {
637 	int msqix, segs_needed, error = 0;
638 	register struct msqid_kernel *msqkptr;
639 	register struct msg *msghdr;
640 	short next;
641 
642 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
643 		return (ENOSYS);
644 
645 	mtx_lock(&msq_mtx);
646 	msqix = IPCID_TO_IX(msqid);
647 
648 	if (msqix < 0 || msqix >= msginfo.msgmni) {
649 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
650 		    msginfo.msgmni));
651 		error = EINVAL;
652 		goto done2;
653 	}
654 
655 	msqkptr = &msqids[msqix];
656 	if (msqkptr->u.msg_qbytes == 0) {
657 		DPRINTF(("no such message queue id\n"));
658 		error = EINVAL;
659 		goto done2;
660 	}
661 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
662 		DPRINTF(("wrong sequence number\n"));
663 		error = EINVAL;
664 		goto done2;
665 	}
666 
667 	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
668 		DPRINTF(("requester doesn't have write access\n"));
669 		goto done2;
670 	}
671 
672 #ifdef MAC
673 	error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
674 	if (error != 0)
675 		goto done2;
676 #endif
677 
678 	segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
679 	DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
680 	    msginfo.msgssz, segs_needed));
681 	for (;;) {
682 		int need_more_resources = 0;
683 
684 		/*
685 		 * check msgsz
686 		 * (inside this loop in case msg_qbytes changes while we sleep)
687 		 */
688 
689 		if (msgsz > msqkptr->u.msg_qbytes) {
690 			DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
691 			error = EINVAL;
692 			goto done2;
693 		}
694 
695 		if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
696 			DPRINTF(("msqid is locked\n"));
697 			need_more_resources = 1;
698 		}
699 		if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
700 			DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
701 			need_more_resources = 1;
702 		}
703 		if (segs_needed > nfree_msgmaps) {
704 			DPRINTF(("segs_needed > nfree_msgmaps\n"));
705 			need_more_resources = 1;
706 		}
707 		if (free_msghdrs == NULL) {
708 			DPRINTF(("no more msghdrs\n"));
709 			need_more_resources = 1;
710 		}
711 
712 		if (need_more_resources) {
713 			int we_own_it;
714 
715 			if ((msgflg & IPC_NOWAIT) != 0) {
716 				DPRINTF(("need more resources but caller "
717 				    "doesn't want to wait\n"));
718 				error = EAGAIN;
719 				goto done2;
720 			}
721 
722 			if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
723 				DPRINTF(("we don't own the msqid_ds\n"));
724 				we_own_it = 0;
725 			} else {
726 				/* Force later arrivals to wait for our
727 				   request */
728 				DPRINTF(("we own the msqid_ds\n"));
729 				msqkptr->u.msg_perm.mode |= MSG_LOCKED;
730 				we_own_it = 1;
731 			}
732 			DPRINTF(("msgsnd:  goodnight\n"));
733 			error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
734 			    "msgsnd", hz);
735 			DPRINTF(("msgsnd:  good morning, error=%d\n", error));
736 			if (we_own_it)
737 				msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
738 			if (error == EWOULDBLOCK) {
739 				DPRINTF(("msgsnd:  timed out\n"));
740 				continue;
741 			}
742 			if (error != 0) {
743 				DPRINTF(("msgsnd:  interrupted system call\n"));
744 				error = EINTR;
745 				goto done2;
746 			}
747 
748 			/*
749 			 * Make sure that the msq queue still exists
750 			 */
751 
752 			if (msqkptr->u.msg_qbytes == 0) {
753 				DPRINTF(("msqid deleted\n"));
754 				error = EIDRM;
755 				goto done2;
756 			}
757 
758 		} else {
759 			DPRINTF(("got all the resources that we need\n"));
760 			break;
761 		}
762 	}
763 
764 	/*
765 	 * We have the resources that we need.
766 	 * Make sure!
767 	 */
768 
769 	if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
770 		panic("msg_perm.mode & MSG_LOCKED");
771 	if (segs_needed > nfree_msgmaps)
772 		panic("segs_needed > nfree_msgmaps");
773 	if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
774 		panic("msgsz + msg_cbytes > msg_qbytes");
775 	if (free_msghdrs == NULL)
776 		panic("no more msghdrs");
777 
778 	/*
779 	 * Re-lock the msqid_ds in case we page-fault when copying in the
780 	 * message
781 	 */
782 
783 	if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
784 		panic("msqid_ds is already locked");
785 	msqkptr->u.msg_perm.mode |= MSG_LOCKED;
786 
787 	/*
788 	 * Allocate a message header
789 	 */
790 
791 	msghdr = free_msghdrs;
792 	free_msghdrs = msghdr->msg_next;
793 	msghdr->msg_spot = -1;
794 	msghdr->msg_ts = msgsz;
795 	msghdr->msg_type = mtype;
796 #ifdef MAC
797 	/*
798 	 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
799 	 * immediately?  Or, should it be checked just before the msg is
800 	 * enqueued in the msgq (as it is done now)?
801 	 */
802 	mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
803 #endif
804 
805 	/*
806 	 * Allocate space for the message
807 	 */
808 
809 	while (segs_needed > 0) {
810 		if (nfree_msgmaps <= 0)
811 			panic("not enough msgmaps");
812 		if (free_msgmaps == -1)
813 			panic("nil free_msgmaps");
814 		next = free_msgmaps;
815 		if (next <= -1)
816 			panic("next too low #1");
817 		if (next >= msginfo.msgseg)
818 			panic("next out of range #1");
819 		DPRINTF(("allocating segment %d to message\n", next));
820 		free_msgmaps = msgmaps[next].next;
821 		nfree_msgmaps--;
822 		msgmaps[next].next = msghdr->msg_spot;
823 		msghdr->msg_spot = next;
824 		segs_needed--;
825 	}
826 
827 	/*
828 	 * Validate the message type
829 	 */
830 
831 	if (msghdr->msg_type < 1) {
832 		msg_freehdr(msghdr);
833 		msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
834 		wakeup(msqkptr);
835 		DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
836 		error = EINVAL;
837 		goto done2;
838 	}
839 
840 	/*
841 	 * Copy in the message body
842 	 */
843 
844 	next = msghdr->msg_spot;
845 	while (msgsz > 0) {
846 		size_t tlen;
847 		if (msgsz > msginfo.msgssz)
848 			tlen = msginfo.msgssz;
849 		else
850 			tlen = msgsz;
851 		if (next <= -1)
852 			panic("next too low #2");
853 		if (next >= msginfo.msgseg)
854 			panic("next out of range #2");
855 		mtx_unlock(&msq_mtx);
856 		if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
857 		    tlen)) != 0) {
858 			mtx_lock(&msq_mtx);
859 			DPRINTF(("error %d copying in message segment\n",
860 			    error));
861 			msg_freehdr(msghdr);
862 			msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
863 			wakeup(msqkptr);
864 			goto done2;
865 		}
866 		mtx_lock(&msq_mtx);
867 		msgsz -= tlen;
868 		msgp = (const char *)msgp + tlen;
869 		next = msgmaps[next].next;
870 	}
871 	if (next != -1)
872 		panic("didn't use all the msg segments");
873 
874 	/*
875 	 * We've got the message.  Unlock the msqid_ds.
876 	 */
877 
878 	msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
879 
880 	/*
881 	 * Make sure that the msqid_ds is still allocated.
882 	 */
883 
884 	if (msqkptr->u.msg_qbytes == 0) {
885 		msg_freehdr(msghdr);
886 		wakeup(msqkptr);
887 		error = EIDRM;
888 		goto done2;
889 	}
890 
891 #ifdef MAC
892 	/*
893 	 * Note: Since the task/thread allocates the msghdr and usually
894 	 * primes it with its own MAC label, for a majority of policies, it
895 	 * won't be necessary to check whether the msghdr has access
896 	 * permissions to the msgq.  The mac_sysvmsq_check_msqsnd check would
897 	 * suffice in that case.  However, this hook may be required where
898 	 * individual policies derive a non-identical label for the msghdr
899 	 * from the current thread label and may want to check the msghdr
900 	 * enqueue permissions, along with read/write permissions to the
901 	 * msgq.
902 	 */
903 	error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
904 	if (error != 0) {
905 		msg_freehdr(msghdr);
906 		wakeup(msqkptr);
907 		goto done2;
908 	}
909 #endif
910 
911 	/*
912 	 * Put the message into the queue
913 	 */
914 	if (msqkptr->u.msg_first == NULL) {
915 		msqkptr->u.msg_first = msghdr;
916 		msqkptr->u.msg_last = msghdr;
917 	} else {
918 		msqkptr->u.msg_last->msg_next = msghdr;
919 		msqkptr->u.msg_last = msghdr;
920 	}
921 	msqkptr->u.msg_last->msg_next = NULL;
922 
923 	msqkptr->u.msg_cbytes += msghdr->msg_ts;
924 	msqkptr->u.msg_qnum++;
925 	msqkptr->u.msg_lspid = td->td_proc->p_pid;
926 	msqkptr->u.msg_stime = time_second;
927 
928 	wakeup(msqkptr);
929 	td->td_retval[0] = 0;
930 done2:
931 	mtx_unlock(&msq_mtx);
932 	return (error);
933 }
934 
935 int
936 msgsnd(td, uap)
937 	struct thread *td;
938 	register struct msgsnd_args *uap;
939 {
940 	int error;
941 	long mtype;
942 
943 	DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
944 	    uap->msgsz, uap->msgflg));
945 
946 	if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
947 		DPRINTF(("error %d copying the message type\n", error));
948 		return (error);
949 	}
950 	return (kern_msgsnd(td, uap->msqid,
951 	    (const char *)uap->msgp + sizeof(mtype),
952 	    uap->msgsz, uap->msgflg, mtype));
953 }
954 
955 #ifndef _SYS_SYSPROTO_H_
956 struct msgrcv_args {
957 	int	msqid;
958 	void	*msgp;
959 	size_t	msgsz;
960 	long	msgtyp;
961 	int	msgflg;
962 };
963 #endif
964 int
965 kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
966 	struct thread *td;
967 	int msqid;
968 	void *msgp;	/* XXX msgp is actually mtext. */
969 	size_t msgsz;
970 	long msgtyp;
971 	int msgflg;
972 	long *mtype;
973 {
974 	size_t len;
975 	register struct msqid_kernel *msqkptr;
976 	register struct msg *msghdr;
977 	int msqix, error = 0;
978 	short next;
979 
980 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
981 		return (ENOSYS);
982 
983 	msqix = IPCID_TO_IX(msqid);
984 
985 	if (msqix < 0 || msqix >= msginfo.msgmni) {
986 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
987 		    msginfo.msgmni));
988 		return (EINVAL);
989 	}
990 
991 	msqkptr = &msqids[msqix];
992 	mtx_lock(&msq_mtx);
993 	if (msqkptr->u.msg_qbytes == 0) {
994 		DPRINTF(("no such message queue id\n"));
995 		error = EINVAL;
996 		goto done2;
997 	}
998 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
999 		DPRINTF(("wrong sequence number\n"));
1000 		error = EINVAL;
1001 		goto done2;
1002 	}
1003 
1004 	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1005 		DPRINTF(("requester doesn't have read access\n"));
1006 		goto done2;
1007 	}
1008 
1009 #ifdef MAC
1010 	error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
1011 	if (error != 0)
1012 		goto done2;
1013 #endif
1014 
1015 	msghdr = NULL;
1016 	while (msghdr == NULL) {
1017 		if (msgtyp == 0) {
1018 			msghdr = msqkptr->u.msg_first;
1019 			if (msghdr != NULL) {
1020 				if (msgsz < msghdr->msg_ts &&
1021 				    (msgflg & MSG_NOERROR) == 0) {
1022 					DPRINTF(("first message on the queue "
1023 					    "is too big (want %zu, got %d)\n",
1024 					    msgsz, msghdr->msg_ts));
1025 					error = E2BIG;
1026 					goto done2;
1027 				}
1028 #ifdef MAC
1029 				error = mac_sysvmsq_check_msgrcv(td->td_ucred,
1030 				    msghdr);
1031 				if (error != 0)
1032 					goto done2;
1033 #endif
1034 				if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1035 					msqkptr->u.msg_first = NULL;
1036 					msqkptr->u.msg_last = NULL;
1037 				} else {
1038 					msqkptr->u.msg_first = msghdr->msg_next;
1039 					if (msqkptr->u.msg_first == NULL)
1040 						panic("msg_first/last screwed up #1");
1041 				}
1042 			}
1043 		} else {
1044 			struct msg *previous;
1045 			struct msg **prev;
1046 
1047 			previous = NULL;
1048 			prev = &(msqkptr->u.msg_first);
1049 			while ((msghdr = *prev) != NULL) {
1050 				/*
1051 				 * Is this message's type an exact match or is
1052 				 * this message's type less than or equal to
1053 				 * the absolute value of a negative msgtyp?
1054 				 * Note that the second half of this test can
1055 				 * NEVER be true if msgtyp is positive since
1056 				 * msg_type is always positive!
1057 				 */
1058 
1059 				if (msgtyp == msghdr->msg_type ||
1060 				    msghdr->msg_type <= -msgtyp) {
1061 					DPRINTF(("found message type %ld, "
1062 					    "requested %ld\n",
1063 					    msghdr->msg_type, msgtyp));
1064 					if (msgsz < msghdr->msg_ts &&
1065 					    (msgflg & MSG_NOERROR) == 0) {
1066 						DPRINTF(("requested message "
1067 						    "on the queue is too big "
1068 						    "(want %zu, got %hu)\n",
1069 						    msgsz, msghdr->msg_ts));
1070 						error = E2BIG;
1071 						goto done2;
1072 					}
1073 #ifdef MAC
1074 					error = mac_sysvmsq_check_msgrcv(
1075 					    td->td_ucred, msghdr);
1076 					if (error != 0)
1077 						goto done2;
1078 #endif
1079 					*prev = msghdr->msg_next;
1080 					if (msghdr == msqkptr->u.msg_last) {
1081 						if (previous == NULL) {
1082 							if (prev !=
1083 							    &msqkptr->u.msg_first)
1084 								panic("msg_first/last screwed up #2");
1085 							msqkptr->u.msg_first =
1086 							    NULL;
1087 							msqkptr->u.msg_last =
1088 							    NULL;
1089 						} else {
1090 							if (prev ==
1091 							    &msqkptr->u.msg_first)
1092 								panic("msg_first/last screwed up #3");
1093 							msqkptr->u.msg_last =
1094 							    previous;
1095 						}
1096 					}
1097 					break;
1098 				}
1099 				previous = msghdr;
1100 				prev = &(msghdr->msg_next);
1101 			}
1102 		}
1103 
1104 		/*
1105 		 * We've either extracted the msghdr for the appropriate
1106 		 * message or there isn't one.
1107 		 * If there is one then bail out of this loop.
1108 		 */
1109 
1110 		if (msghdr != NULL)
1111 			break;
1112 
1113 		/*
1114 		 * Hmph!  No message found.  Does the user want to wait?
1115 		 */
1116 
1117 		if ((msgflg & IPC_NOWAIT) != 0) {
1118 			DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1119 			    msgtyp));
1120 			/* The SVID says to return ENOMSG. */
1121 			error = ENOMSG;
1122 			goto done2;
1123 		}
1124 
1125 		/*
1126 		 * Wait for something to happen
1127 		 */
1128 
1129 		DPRINTF(("msgrcv:  goodnight\n"));
1130 		error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1131 		    "msgrcv", 0);
1132 		DPRINTF(("msgrcv:  good morning (error=%d)\n", error));
1133 
1134 		if (error != 0) {
1135 			DPRINTF(("msgrcv:  interrupted system call\n"));
1136 			error = EINTR;
1137 			goto done2;
1138 		}
1139 
1140 		/*
1141 		 * Make sure that the msq queue still exists
1142 		 */
1143 
1144 		if (msqkptr->u.msg_qbytes == 0 ||
1145 		    msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1146 			DPRINTF(("msqid deleted\n"));
1147 			error = EIDRM;
1148 			goto done2;
1149 		}
1150 	}
1151 
1152 	/*
1153 	 * Return the message to the user.
1154 	 *
1155 	 * First, do the bookkeeping (before we risk being interrupted).
1156 	 */
1157 
1158 	msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1159 	msqkptr->u.msg_qnum--;
1160 	msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1161 	msqkptr->u.msg_rtime = time_second;
1162 
1163 	/*
1164 	 * Make msgsz the actual amount that we'll be returning.
1165 	 * Note that this effectively truncates the message if it is too long
1166 	 * (since msgsz is never increased).
1167 	 */
1168 
1169 	DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1170 	    msghdr->msg_ts));
1171 	if (msgsz > msghdr->msg_ts)
1172 		msgsz = msghdr->msg_ts;
1173 	*mtype = msghdr->msg_type;
1174 
1175 	/*
1176 	 * Return the segments to the user
1177 	 */
1178 
1179 	next = msghdr->msg_spot;
1180 	for (len = 0; len < msgsz; len += msginfo.msgssz) {
1181 		size_t tlen;
1182 
1183 		if (msgsz - len > msginfo.msgssz)
1184 			tlen = msginfo.msgssz;
1185 		else
1186 			tlen = msgsz - len;
1187 		if (next <= -1)
1188 			panic("next too low #3");
1189 		if (next >= msginfo.msgseg)
1190 			panic("next out of range #3");
1191 		mtx_unlock(&msq_mtx);
1192 		error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1193 		mtx_lock(&msq_mtx);
1194 		if (error != 0) {
1195 			DPRINTF(("error (%d) copying out message segment\n",
1196 			    error));
1197 			msg_freehdr(msghdr);
1198 			wakeup(msqkptr);
1199 			goto done2;
1200 		}
1201 		msgp = (char *)msgp + tlen;
1202 		next = msgmaps[next].next;
1203 	}
1204 
1205 	/*
1206 	 * Done, return the actual number of bytes copied out.
1207 	 */
1208 
1209 	msg_freehdr(msghdr);
1210 	wakeup(msqkptr);
1211 	td->td_retval[0] = msgsz;
1212 done2:
1213 	mtx_unlock(&msq_mtx);
1214 	return (error);
1215 }
1216 
1217 int
1218 msgrcv(td, uap)
1219 	struct thread *td;
1220 	register struct msgrcv_args *uap;
1221 {
1222 	int error;
1223 	long mtype;
1224 
1225 	DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1226 	    uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1227 
1228 	if ((error = kern_msgrcv(td, uap->msqid,
1229 	    (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1230 	    uap->msgtyp, uap->msgflg, &mtype)) != 0)
1231 		return (error);
1232 	if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1233 		DPRINTF(("error %d copying the message type\n", error));
1234 	return (error);
1235 }
1236 
1237 static int
1238 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1239 {
1240 
1241 	return (SYSCTL_OUT(req, msqids,
1242 	    sizeof(struct msqid_kernel) * msginfo.msgmni));
1243 }
1244 
1245 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1246     "Maximum message size");
1247 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1248     "Number of message queue identifiers");
1249 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1250     "Maximum number of bytes in a queue");
1251 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1252     "Maximum number of messages in the system");
1253 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1254     "Size of a message segment");
1255 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1256     "Number of message segments");
1257 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1258     NULL, 0, sysctl_msqids, "", "Message queue IDs");
1259 
1260 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1261     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1262 SYSCALL_MODULE_HELPER(msgsys);
1263 SYSCALL_MODULE_HELPER(freebsd7_msgctl);
1264 
1265 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1266 static sy_call_t *msgcalls[] = {
1267 	(sy_call_t *)freebsd7_msgctl, (sy_call_t *)msgget,
1268 	(sy_call_t *)msgsnd, (sy_call_t *)msgrcv
1269 };
1270 
1271 /*
1272  * Entry point for all MSG calls.
1273  */
1274 int
1275 msgsys(td, uap)
1276 	struct thread *td;
1277 	/* XXX actually varargs. */
1278 	struct msgsys_args /* {
1279 		int	which;
1280 		int	a2;
1281 		int	a3;
1282 		int	a4;
1283 		int	a5;
1284 		int	a6;
1285 	} */ *uap;
1286 {
1287 	int error;
1288 
1289 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1290 		return (ENOSYS);
1291 	if (uap->which < 0 ||
1292 	    uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
1293 		return (EINVAL);
1294 	error = (*msgcalls[uap->which])(td, &uap->a2);
1295 	return (error);
1296 }
1297 
1298 #define CP(src, dst, fld)	do { (dst).fld = (src).fld; } while (0)
1299 
1300 #ifndef _SYS_SYSPROTO_H_
1301 struct freebsd7_msgctl_args {
1302 	int	msqid;
1303 	int	cmd;
1304 	struct	msqid_ds_old *buf;
1305 };
1306 #endif
1307 int
1308 freebsd7_msgctl(td, uap)
1309 	struct thread *td;
1310 	struct freebsd7_msgctl_args *uap;
1311 {
1312 	struct msqid_ds_old msqold;
1313 	struct msqid_ds msqbuf;
1314 	int error;
1315 
1316 	DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
1317 	    uap->buf));
1318 	if (uap->cmd == IPC_SET) {
1319 		error = copyin(uap->buf, &msqold, sizeof(msqold));
1320 		if (error)
1321 			return (error);
1322 		ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
1323 		CP(msqold, msqbuf, msg_first);
1324 		CP(msqold, msqbuf, msg_last);
1325 		CP(msqold, msqbuf, msg_cbytes);
1326 		CP(msqold, msqbuf, msg_qnum);
1327 		CP(msqold, msqbuf, msg_qbytes);
1328 		CP(msqold, msqbuf, msg_lspid);
1329 		CP(msqold, msqbuf, msg_lrpid);
1330 		CP(msqold, msqbuf, msg_stime);
1331 		CP(msqold, msqbuf, msg_rtime);
1332 		CP(msqold, msqbuf, msg_ctime);
1333 	}
1334 	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1335 	if (error)
1336 		return (error);
1337 	if (uap->cmd == IPC_STAT) {
1338 		bzero(&msqold, sizeof(msqold));
1339 		ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
1340 		CP(msqbuf, msqold, msg_first);
1341 		CP(msqbuf, msqold, msg_last);
1342 		CP(msqbuf, msqold, msg_cbytes);
1343 		CP(msqbuf, msqold, msg_qnum);
1344 		CP(msqbuf, msqold, msg_qbytes);
1345 		CP(msqbuf, msqold, msg_lspid);
1346 		CP(msqbuf, msqold, msg_lrpid);
1347 		CP(msqbuf, msqold, msg_stime);
1348 		CP(msqbuf, msqold, msg_rtime);
1349 		CP(msqbuf, msqold, msg_ctime);
1350 		error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
1351 	}
1352 	return (error);
1353 }
1354 
1355 #undef CP
1356 
1357 #endif	/* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1358 	   COMPAT_FREEBSD7 */
1359