xref: /freebsd/sys/kern/sysv_msg.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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 int 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 struct syscall_helper_data msg_syscalls[] = {
156 	SYSCALL_INIT_HELPER(msgctl),
157 	SYSCALL_INIT_HELPER(msgget),
158 	SYSCALL_INIT_HELPER(msgsnd),
159 	SYSCALL_INIT_HELPER(msgrcv),
160 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
161     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
162 	SYSCALL_INIT_HELPER(msgsys),
163 	SYSCALL_INIT_HELPER(freebsd7_msgctl),
164 #endif
165 	SYSCALL_INIT_LAST
166 };
167 
168 #ifdef COMPAT_FREEBSD32
169 #include <compat/freebsd32/freebsd32.h>
170 #include <compat/freebsd32/freebsd32_ipc.h>
171 #include <compat/freebsd32/freebsd32_proto.h>
172 #include <compat/freebsd32/freebsd32_signal.h>
173 #include <compat/freebsd32/freebsd32_syscall.h>
174 #include <compat/freebsd32/freebsd32_util.h>
175 
176 static struct syscall_helper_data msg32_syscalls[] = {
177 	SYSCALL32_INIT_HELPER(freebsd32_msgctl),
178 	SYSCALL32_INIT_HELPER(freebsd32_msgsnd),
179 	SYSCALL32_INIT_HELPER(freebsd32_msgrcv),
180 	SYSCALL32_INIT_HELPER(msgget),
181 	SYSCALL32_INIT_HELPER(freebsd32_msgsys),
182 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
183     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
184 	SYSCALL32_INIT_HELPER(freebsd7_freebsd32_msgctl),
185 #endif
186 	SYSCALL_INIT_LAST
187 };
188 #endif
189 
190 static int
191 msginit()
192 {
193 	int i, error;
194 
195 	TUNABLE_INT_FETCH("kern.ipc.msgseg", &msginfo.msgseg);
196 	TUNABLE_INT_FETCH("kern.ipc.msgssz", &msginfo.msgssz);
197 	msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
198 	TUNABLE_INT_FETCH("kern.ipc.msgmni", &msginfo.msgmni);
199 	TUNABLE_INT_FETCH("kern.ipc.msgmnb", &msginfo.msgmnb);
200 	TUNABLE_INT_FETCH("kern.ipc.msgtql", &msginfo.msgtql);
201 
202 	msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
203 	msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
204 	msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
205 	msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
206 	    M_WAITOK);
207 
208 	/*
209 	 * msginfo.msgssz should be a power of two for efficiency reasons.
210 	 * It is also pretty silly if msginfo.msgssz is less than 8
211 	 * or greater than about 256 so ...
212 	 */
213 
214 	i = 8;
215 	while (i < 1024 && i != msginfo.msgssz)
216 		i <<= 1;
217     	if (i != msginfo.msgssz) {
218 		DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
219 		    msginfo.msgssz));
220 		panic("msginfo.msgssz not a small power of 2");
221 	}
222 
223 	if (msginfo.msgseg > 32767) {
224 		DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
225 		panic("msginfo.msgseg > 32767");
226 	}
227 
228 	for (i = 0; i < msginfo.msgseg; i++) {
229 		if (i > 0)
230 			msgmaps[i-1].next = i;
231 		msgmaps[i].next = -1;	/* implies entry is available */
232 	}
233 	free_msgmaps = 0;
234 	nfree_msgmaps = msginfo.msgseg;
235 
236 	for (i = 0; i < msginfo.msgtql; i++) {
237 		msghdrs[i].msg_type = 0;
238 		if (i > 0)
239 			msghdrs[i-1].msg_next = &msghdrs[i];
240 		msghdrs[i].msg_next = NULL;
241 #ifdef MAC
242 		mac_sysvmsg_init(&msghdrs[i]);
243 #endif
244     	}
245 	free_msghdrs = &msghdrs[0];
246 
247 	for (i = 0; i < msginfo.msgmni; i++) {
248 		msqids[i].u.msg_qbytes = 0;	/* implies entry is available */
249 		msqids[i].u.msg_perm.seq = 0;	/* reset to a known value */
250 		msqids[i].u.msg_perm.mode = 0;
251 #ifdef MAC
252 		mac_sysvmsq_init(&msqids[i]);
253 #endif
254 	}
255 	mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
256 
257 	error = syscall_helper_register(msg_syscalls);
258 	if (error != 0)
259 		return (error);
260 #ifdef COMPAT_FREEBSD32
261 	error = syscall32_helper_register(msg32_syscalls);
262 	if (error != 0)
263 		return (error);
264 #endif
265 	return (0);
266 }
267 
268 static int
269 msgunload()
270 {
271 	struct msqid_kernel *msqkptr;
272 	int msqid;
273 #ifdef MAC
274 	int i;
275 #endif
276 
277 	syscall_helper_unregister(msg_syscalls);
278 #ifdef COMPAT_FREEBSD32
279 	syscall32_helper_unregister(msg32_syscalls);
280 #endif
281 
282 	for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
283 		/*
284 		 * Look for an unallocated and unlocked msqid_ds.
285 		 * msqid_ds's can be locked by msgsnd or msgrcv while
286 		 * they are copying the message in/out.  We can't
287 		 * re-use the entry until they release it.
288 		 */
289 		msqkptr = &msqids[msqid];
290 		if (msqkptr->u.msg_qbytes != 0 ||
291 		    (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
292 			break;
293 	}
294 	if (msqid != msginfo.msgmni)
295 		return (EBUSY);
296 
297 #ifdef MAC
298 	for (i = 0; i < msginfo.msgtql; i++)
299 		mac_sysvmsg_destroy(&msghdrs[i]);
300 	for (msqid = 0; msqid < msginfo.msgmni; msqid++)
301 		mac_sysvmsq_destroy(&msqids[msqid]);
302 #endif
303 	free(msgpool, M_MSG);
304 	free(msgmaps, M_MSG);
305 	free(msghdrs, M_MSG);
306 	free(msqids, M_MSG);
307 	mtx_destroy(&msq_mtx);
308 	return (0);
309 }
310 
311 
312 static int
313 sysvmsg_modload(struct module *module, int cmd, void *arg)
314 {
315 	int error = 0;
316 
317 	switch (cmd) {
318 	case MOD_LOAD:
319 		error = msginit();
320 		if (error != 0)
321 			msgunload();
322 		break;
323 	case MOD_UNLOAD:
324 		error = msgunload();
325 		break;
326 	case MOD_SHUTDOWN:
327 		break;
328 	default:
329 		error = EINVAL;
330 		break;
331 	}
332 	return (error);
333 }
334 
335 static moduledata_t sysvmsg_mod = {
336 	"sysvmsg",
337 	&sysvmsg_modload,
338 	NULL
339 };
340 
341 DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
342 MODULE_VERSION(sysvmsg, 1);
343 
344 static void
345 msg_freehdr(msghdr)
346 	struct msg *msghdr;
347 {
348 	while (msghdr->msg_ts > 0) {
349 		short next;
350 		if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
351 			panic("msghdr->msg_spot out of range");
352 		next = msgmaps[msghdr->msg_spot].next;
353 		msgmaps[msghdr->msg_spot].next = free_msgmaps;
354 		free_msgmaps = msghdr->msg_spot;
355 		nfree_msgmaps++;
356 		msghdr->msg_spot = next;
357 		if (msghdr->msg_ts >= msginfo.msgssz)
358 			msghdr->msg_ts -= msginfo.msgssz;
359 		else
360 			msghdr->msg_ts = 0;
361 	}
362 	if (msghdr->msg_spot != -1)
363 		panic("msghdr->msg_spot != -1");
364 	msghdr->msg_next = free_msghdrs;
365 	free_msghdrs = msghdr;
366 #ifdef MAC
367 	mac_sysvmsg_cleanup(msghdr);
368 #endif
369 }
370 
371 #ifndef _SYS_SYSPROTO_H_
372 struct msgctl_args {
373 	int	msqid;
374 	int	cmd;
375 	struct	msqid_ds *buf;
376 };
377 #endif
378 int
379 msgctl(td, uap)
380 	struct thread *td;
381 	register struct msgctl_args *uap;
382 {
383 	int msqid = uap->msqid;
384 	int cmd = uap->cmd;
385 	struct msqid_ds msqbuf;
386 	int error;
387 
388 	DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
389 	if (cmd == IPC_SET &&
390 	    (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
391 		return (error);
392 	error = kern_msgctl(td, msqid, cmd, &msqbuf);
393 	if (cmd == IPC_STAT && error == 0)
394 		error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
395 	return (error);
396 }
397 
398 int
399 kern_msgctl(td, msqid, cmd, msqbuf)
400 	struct thread *td;
401 	int msqid;
402 	int cmd;
403 	struct msqid_ds *msqbuf;
404 {
405 	int rval, error, msqix;
406 	register struct msqid_kernel *msqkptr;
407 
408 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
409 		return (ENOSYS);
410 
411 	msqix = IPCID_TO_IX(msqid);
412 
413 	if (msqix < 0 || msqix >= msginfo.msgmni) {
414 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
415 		    msginfo.msgmni));
416 		return (EINVAL);
417 	}
418 
419 	msqkptr = &msqids[msqix];
420 
421 	mtx_lock(&msq_mtx);
422 	if (msqkptr->u.msg_qbytes == 0) {
423 		DPRINTF(("no such msqid\n"));
424 		error = EINVAL;
425 		goto done2;
426 	}
427 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
428 		DPRINTF(("wrong sequence number\n"));
429 		error = EINVAL;
430 		goto done2;
431 	}
432 #ifdef MAC
433 	error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
434 	if (error != 0)
435 		goto done2;
436 #endif
437 
438 	error = 0;
439 	rval = 0;
440 
441 	switch (cmd) {
442 
443 	case IPC_RMID:
444 	{
445 		struct msg *msghdr;
446 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
447 			goto done2;
448 
449 #ifdef MAC
450 		/*
451 		 * Check that the thread has MAC access permissions to
452 		 * individual msghdrs.  Note: We need to do this in a
453 		 * separate loop because the actual loop alters the
454 		 * msq/msghdr info as it progresses, and there is no going
455 		 * back if half the way through we discover that the
456 		 * thread cannot free a certain msghdr.  The msq will get
457 		 * into an inconsistent state.
458 		 */
459 		for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
460 		    msghdr = msghdr->msg_next) {
461 			error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
462 			if (error != 0)
463 				goto done2;
464 		}
465 #endif
466 
467 		/* Free the message headers */
468 		msghdr = msqkptr->u.msg_first;
469 		while (msghdr != NULL) {
470 			struct msg *msghdr_tmp;
471 
472 			/* Free the segments of each message */
473 			msqkptr->u.msg_cbytes -= msghdr->msg_ts;
474 			msqkptr->u.msg_qnum--;
475 			msghdr_tmp = msghdr;
476 			msghdr = msghdr->msg_next;
477 			msg_freehdr(msghdr_tmp);
478 		}
479 
480 		if (msqkptr->u.msg_cbytes != 0)
481 			panic("msg_cbytes is screwed up");
482 		if (msqkptr->u.msg_qnum != 0)
483 			panic("msg_qnum is screwed up");
484 
485 		msqkptr->u.msg_qbytes = 0;	/* Mark it as free */
486 
487 #ifdef MAC
488 		mac_sysvmsq_cleanup(msqkptr);
489 #endif
490 
491 		wakeup(msqkptr);
492 	}
493 
494 		break;
495 
496 	case IPC_SET:
497 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
498 			goto done2;
499 		if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
500 			error = priv_check(td, PRIV_IPC_MSGSIZE);
501 			if (error)
502 				goto done2;
503 		}
504 		if (msqbuf->msg_qbytes > msginfo.msgmnb) {
505 			DPRINTF(("can't increase msg_qbytes beyond %d"
506 			    "(truncating)\n", msginfo.msgmnb));
507 			msqbuf->msg_qbytes = msginfo.msgmnb;	/* silently restrict qbytes to system limit */
508 		}
509 		if (msqbuf->msg_qbytes == 0) {
510 			DPRINTF(("can't reduce msg_qbytes to 0\n"));
511 			error = EINVAL;		/* non-standard errno! */
512 			goto done2;
513 		}
514 		msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid;	/* change the owner */
515 		msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid;	/* change the owner */
516 		msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
517 		    (msqbuf->msg_perm.mode & 0777);
518 		msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
519 		msqkptr->u.msg_ctime = time_second;
520 		break;
521 
522 	case IPC_STAT:
523 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
524 			DPRINTF(("requester doesn't have read access\n"));
525 			goto done2;
526 		}
527 		*msqbuf = msqkptr->u;
528 		break;
529 
530 	default:
531 		DPRINTF(("invalid command %d\n", cmd));
532 		error = EINVAL;
533 		goto done2;
534 	}
535 
536 	if (error == 0)
537 		td->td_retval[0] = rval;
538 done2:
539 	mtx_unlock(&msq_mtx);
540 	return (error);
541 }
542 
543 #ifndef _SYS_SYSPROTO_H_
544 struct msgget_args {
545 	key_t	key;
546 	int	msgflg;
547 };
548 #endif
549 int
550 msgget(td, uap)
551 	struct thread *td;
552 	register struct msgget_args *uap;
553 {
554 	int msqid, error = 0;
555 	int key = uap->key;
556 	int msgflg = uap->msgflg;
557 	struct ucred *cred = td->td_ucred;
558 	register struct msqid_kernel *msqkptr = NULL;
559 
560 	DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
561 
562 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
563 		return (ENOSYS);
564 
565 	mtx_lock(&msq_mtx);
566 	if (key != IPC_PRIVATE) {
567 		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
568 			msqkptr = &msqids[msqid];
569 			if (msqkptr->u.msg_qbytes != 0 &&
570 			    msqkptr->u.msg_perm.key == key)
571 				break;
572 		}
573 		if (msqid < msginfo.msgmni) {
574 			DPRINTF(("found public key\n"));
575 			if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
576 				DPRINTF(("not exclusive\n"));
577 				error = EEXIST;
578 				goto done2;
579 			}
580 			if ((error = ipcperm(td, &msqkptr->u.msg_perm,
581 			    msgflg & 0700))) {
582 				DPRINTF(("requester doesn't have 0%o access\n",
583 				    msgflg & 0700));
584 				goto done2;
585 			}
586 #ifdef MAC
587 			error = mac_sysvmsq_check_msqget(cred, msqkptr);
588 			if (error != 0)
589 				goto done2;
590 #endif
591 			goto found;
592 		}
593 	}
594 
595 	DPRINTF(("need to allocate the msqid_ds\n"));
596 	if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
597 		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
598 			/*
599 			 * Look for an unallocated and unlocked msqid_ds.
600 			 * msqid_ds's can be locked by msgsnd or msgrcv while
601 			 * they are copying the message in/out.  We can't
602 			 * re-use the entry until they release it.
603 			 */
604 			msqkptr = &msqids[msqid];
605 			if (msqkptr->u.msg_qbytes == 0 &&
606 			    (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
607 				break;
608 		}
609 		if (msqid == msginfo.msgmni) {
610 			DPRINTF(("no more msqid_ds's available\n"));
611 			error = ENOSPC;
612 			goto done2;
613 		}
614 		DPRINTF(("msqid %d is available\n", msqid));
615 		msqkptr->u.msg_perm.key = key;
616 		msqkptr->u.msg_perm.cuid = cred->cr_uid;
617 		msqkptr->u.msg_perm.uid = cred->cr_uid;
618 		msqkptr->u.msg_perm.cgid = cred->cr_gid;
619 		msqkptr->u.msg_perm.gid = cred->cr_gid;
620 		msqkptr->u.msg_perm.mode = (msgflg & 0777);
621 		/* Make sure that the returned msqid is unique */
622 		msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
623 		msqkptr->u.msg_first = NULL;
624 		msqkptr->u.msg_last = NULL;
625 		msqkptr->u.msg_cbytes = 0;
626 		msqkptr->u.msg_qnum = 0;
627 		msqkptr->u.msg_qbytes = msginfo.msgmnb;
628 		msqkptr->u.msg_lspid = 0;
629 		msqkptr->u.msg_lrpid = 0;
630 		msqkptr->u.msg_stime = 0;
631 		msqkptr->u.msg_rtime = 0;
632 		msqkptr->u.msg_ctime = time_second;
633 #ifdef MAC
634 		mac_sysvmsq_create(cred, msqkptr);
635 #endif
636 	} else {
637 		DPRINTF(("didn't find it and wasn't asked to create it\n"));
638 		error = ENOENT;
639 		goto done2;
640 	}
641 
642 found:
643 	/* Construct the unique msqid */
644 	td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
645 done2:
646 	mtx_unlock(&msq_mtx);
647 	return (error);
648 }
649 
650 #ifndef _SYS_SYSPROTO_H_
651 struct msgsnd_args {
652 	int	msqid;
653 	const void	*msgp;
654 	size_t	msgsz;
655 	int	msgflg;
656 };
657 #endif
658 int
659 kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
660 	struct thread *td;
661 	int msqid;
662 	const void *msgp;	/* XXX msgp is actually mtext. */
663 	size_t msgsz;
664 	int msgflg;
665 	long mtype;
666 {
667 	int msqix, segs_needed, error = 0;
668 	register struct msqid_kernel *msqkptr;
669 	register struct msg *msghdr;
670 	short next;
671 
672 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
673 		return (ENOSYS);
674 
675 	mtx_lock(&msq_mtx);
676 	msqix = IPCID_TO_IX(msqid);
677 
678 	if (msqix < 0 || msqix >= msginfo.msgmni) {
679 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
680 		    msginfo.msgmni));
681 		error = EINVAL;
682 		goto done2;
683 	}
684 
685 	msqkptr = &msqids[msqix];
686 	if (msqkptr->u.msg_qbytes == 0) {
687 		DPRINTF(("no such message queue id\n"));
688 		error = EINVAL;
689 		goto done2;
690 	}
691 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
692 		DPRINTF(("wrong sequence number\n"));
693 		error = EINVAL;
694 		goto done2;
695 	}
696 
697 	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
698 		DPRINTF(("requester doesn't have write access\n"));
699 		goto done2;
700 	}
701 
702 #ifdef MAC
703 	error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
704 	if (error != 0)
705 		goto done2;
706 #endif
707 
708 	segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
709 	DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
710 	    msginfo.msgssz, segs_needed));
711 	for (;;) {
712 		int need_more_resources = 0;
713 
714 		/*
715 		 * check msgsz
716 		 * (inside this loop in case msg_qbytes changes while we sleep)
717 		 */
718 
719 		if (msgsz > msqkptr->u.msg_qbytes) {
720 			DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
721 			error = EINVAL;
722 			goto done2;
723 		}
724 
725 		if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
726 			DPRINTF(("msqid is locked\n"));
727 			need_more_resources = 1;
728 		}
729 		if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
730 			DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
731 			need_more_resources = 1;
732 		}
733 		if (segs_needed > nfree_msgmaps) {
734 			DPRINTF(("segs_needed > nfree_msgmaps\n"));
735 			need_more_resources = 1;
736 		}
737 		if (free_msghdrs == NULL) {
738 			DPRINTF(("no more msghdrs\n"));
739 			need_more_resources = 1;
740 		}
741 
742 		if (need_more_resources) {
743 			int we_own_it;
744 
745 			if ((msgflg & IPC_NOWAIT) != 0) {
746 				DPRINTF(("need more resources but caller "
747 				    "doesn't want to wait\n"));
748 				error = EAGAIN;
749 				goto done2;
750 			}
751 
752 			if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
753 				DPRINTF(("we don't own the msqid_ds\n"));
754 				we_own_it = 0;
755 			} else {
756 				/* Force later arrivals to wait for our
757 				   request */
758 				DPRINTF(("we own the msqid_ds\n"));
759 				msqkptr->u.msg_perm.mode |= MSG_LOCKED;
760 				we_own_it = 1;
761 			}
762 			DPRINTF(("msgsnd:  goodnight\n"));
763 			error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
764 			    "msgsnd", hz);
765 			DPRINTF(("msgsnd:  good morning, error=%d\n", error));
766 			if (we_own_it)
767 				msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
768 			if (error == EWOULDBLOCK) {
769 				DPRINTF(("msgsnd:  timed out\n"));
770 				continue;
771 			}
772 			if (error != 0) {
773 				DPRINTF(("msgsnd:  interrupted system call\n"));
774 				error = EINTR;
775 				goto done2;
776 			}
777 
778 			/*
779 			 * Make sure that the msq queue still exists
780 			 */
781 
782 			if (msqkptr->u.msg_qbytes == 0) {
783 				DPRINTF(("msqid deleted\n"));
784 				error = EIDRM;
785 				goto done2;
786 			}
787 
788 		} else {
789 			DPRINTF(("got all the resources that we need\n"));
790 			break;
791 		}
792 	}
793 
794 	/*
795 	 * We have the resources that we need.
796 	 * Make sure!
797 	 */
798 
799 	if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
800 		panic("msg_perm.mode & MSG_LOCKED");
801 	if (segs_needed > nfree_msgmaps)
802 		panic("segs_needed > nfree_msgmaps");
803 	if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
804 		panic("msgsz + msg_cbytes > msg_qbytes");
805 	if (free_msghdrs == NULL)
806 		panic("no more msghdrs");
807 
808 	/*
809 	 * Re-lock the msqid_ds in case we page-fault when copying in the
810 	 * message
811 	 */
812 
813 	if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
814 		panic("msqid_ds is already locked");
815 	msqkptr->u.msg_perm.mode |= MSG_LOCKED;
816 
817 	/*
818 	 * Allocate a message header
819 	 */
820 
821 	msghdr = free_msghdrs;
822 	free_msghdrs = msghdr->msg_next;
823 	msghdr->msg_spot = -1;
824 	msghdr->msg_ts = msgsz;
825 	msghdr->msg_type = mtype;
826 #ifdef MAC
827 	/*
828 	 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
829 	 * immediately?  Or, should it be checked just before the msg is
830 	 * enqueued in the msgq (as it is done now)?
831 	 */
832 	mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
833 #endif
834 
835 	/*
836 	 * Allocate space for the message
837 	 */
838 
839 	while (segs_needed > 0) {
840 		if (nfree_msgmaps <= 0)
841 			panic("not enough msgmaps");
842 		if (free_msgmaps == -1)
843 			panic("nil free_msgmaps");
844 		next = free_msgmaps;
845 		if (next <= -1)
846 			panic("next too low #1");
847 		if (next >= msginfo.msgseg)
848 			panic("next out of range #1");
849 		DPRINTF(("allocating segment %d to message\n", next));
850 		free_msgmaps = msgmaps[next].next;
851 		nfree_msgmaps--;
852 		msgmaps[next].next = msghdr->msg_spot;
853 		msghdr->msg_spot = next;
854 		segs_needed--;
855 	}
856 
857 	/*
858 	 * Validate the message type
859 	 */
860 
861 	if (msghdr->msg_type < 1) {
862 		msg_freehdr(msghdr);
863 		msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
864 		wakeup(msqkptr);
865 		DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
866 		error = EINVAL;
867 		goto done2;
868 	}
869 
870 	/*
871 	 * Copy in the message body
872 	 */
873 
874 	next = msghdr->msg_spot;
875 	while (msgsz > 0) {
876 		size_t tlen;
877 		if (msgsz > msginfo.msgssz)
878 			tlen = msginfo.msgssz;
879 		else
880 			tlen = msgsz;
881 		if (next <= -1)
882 			panic("next too low #2");
883 		if (next >= msginfo.msgseg)
884 			panic("next out of range #2");
885 		mtx_unlock(&msq_mtx);
886 		if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
887 		    tlen)) != 0) {
888 			mtx_lock(&msq_mtx);
889 			DPRINTF(("error %d copying in message segment\n",
890 			    error));
891 			msg_freehdr(msghdr);
892 			msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
893 			wakeup(msqkptr);
894 			goto done2;
895 		}
896 		mtx_lock(&msq_mtx);
897 		msgsz -= tlen;
898 		msgp = (const char *)msgp + tlen;
899 		next = msgmaps[next].next;
900 	}
901 	if (next != -1)
902 		panic("didn't use all the msg segments");
903 
904 	/*
905 	 * We've got the message.  Unlock the msqid_ds.
906 	 */
907 
908 	msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
909 
910 	/*
911 	 * Make sure that the msqid_ds is still allocated.
912 	 */
913 
914 	if (msqkptr->u.msg_qbytes == 0) {
915 		msg_freehdr(msghdr);
916 		wakeup(msqkptr);
917 		error = EIDRM;
918 		goto done2;
919 	}
920 
921 #ifdef MAC
922 	/*
923 	 * Note: Since the task/thread allocates the msghdr and usually
924 	 * primes it with its own MAC label, for a majority of policies, it
925 	 * won't be necessary to check whether the msghdr has access
926 	 * permissions to the msgq.  The mac_sysvmsq_check_msqsnd check would
927 	 * suffice in that case.  However, this hook may be required where
928 	 * individual policies derive a non-identical label for the msghdr
929 	 * from the current thread label and may want to check the msghdr
930 	 * enqueue permissions, along with read/write permissions to the
931 	 * msgq.
932 	 */
933 	error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
934 	if (error != 0) {
935 		msg_freehdr(msghdr);
936 		wakeup(msqkptr);
937 		goto done2;
938 	}
939 #endif
940 
941 	/*
942 	 * Put the message into the queue
943 	 */
944 	if (msqkptr->u.msg_first == NULL) {
945 		msqkptr->u.msg_first = msghdr;
946 		msqkptr->u.msg_last = msghdr;
947 	} else {
948 		msqkptr->u.msg_last->msg_next = msghdr;
949 		msqkptr->u.msg_last = msghdr;
950 	}
951 	msqkptr->u.msg_last->msg_next = NULL;
952 
953 	msqkptr->u.msg_cbytes += msghdr->msg_ts;
954 	msqkptr->u.msg_qnum++;
955 	msqkptr->u.msg_lspid = td->td_proc->p_pid;
956 	msqkptr->u.msg_stime = time_second;
957 
958 	wakeup(msqkptr);
959 	td->td_retval[0] = 0;
960 done2:
961 	mtx_unlock(&msq_mtx);
962 	return (error);
963 }
964 
965 int
966 msgsnd(td, uap)
967 	struct thread *td;
968 	register struct msgsnd_args *uap;
969 {
970 	int error;
971 	long mtype;
972 
973 	DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
974 	    uap->msgsz, uap->msgflg));
975 
976 	if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
977 		DPRINTF(("error %d copying the message type\n", error));
978 		return (error);
979 	}
980 	return (kern_msgsnd(td, uap->msqid,
981 	    (const char *)uap->msgp + sizeof(mtype),
982 	    uap->msgsz, uap->msgflg, mtype));
983 }
984 
985 #ifndef _SYS_SYSPROTO_H_
986 struct msgrcv_args {
987 	int	msqid;
988 	void	*msgp;
989 	size_t	msgsz;
990 	long	msgtyp;
991 	int	msgflg;
992 };
993 #endif
994 int
995 kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
996 	struct thread *td;
997 	int msqid;
998 	void *msgp;	/* XXX msgp is actually mtext. */
999 	size_t msgsz;
1000 	long msgtyp;
1001 	int msgflg;
1002 	long *mtype;
1003 {
1004 	size_t len;
1005 	register struct msqid_kernel *msqkptr;
1006 	register struct msg *msghdr;
1007 	int msqix, error = 0;
1008 	short next;
1009 
1010 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1011 		return (ENOSYS);
1012 
1013 	msqix = IPCID_TO_IX(msqid);
1014 
1015 	if (msqix < 0 || msqix >= msginfo.msgmni) {
1016 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
1017 		    msginfo.msgmni));
1018 		return (EINVAL);
1019 	}
1020 
1021 	msqkptr = &msqids[msqix];
1022 	mtx_lock(&msq_mtx);
1023 	if (msqkptr->u.msg_qbytes == 0) {
1024 		DPRINTF(("no such message queue id\n"));
1025 		error = EINVAL;
1026 		goto done2;
1027 	}
1028 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1029 		DPRINTF(("wrong sequence number\n"));
1030 		error = EINVAL;
1031 		goto done2;
1032 	}
1033 
1034 	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1035 		DPRINTF(("requester doesn't have read access\n"));
1036 		goto done2;
1037 	}
1038 
1039 #ifdef MAC
1040 	error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
1041 	if (error != 0)
1042 		goto done2;
1043 #endif
1044 
1045 	msghdr = NULL;
1046 	while (msghdr == NULL) {
1047 		if (msgtyp == 0) {
1048 			msghdr = msqkptr->u.msg_first;
1049 			if (msghdr != NULL) {
1050 				if (msgsz < msghdr->msg_ts &&
1051 				    (msgflg & MSG_NOERROR) == 0) {
1052 					DPRINTF(("first message on the queue "
1053 					    "is too big (want %zu, got %d)\n",
1054 					    msgsz, msghdr->msg_ts));
1055 					error = E2BIG;
1056 					goto done2;
1057 				}
1058 #ifdef MAC
1059 				error = mac_sysvmsq_check_msgrcv(td->td_ucred,
1060 				    msghdr);
1061 				if (error != 0)
1062 					goto done2;
1063 #endif
1064 				if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1065 					msqkptr->u.msg_first = NULL;
1066 					msqkptr->u.msg_last = NULL;
1067 				} else {
1068 					msqkptr->u.msg_first = msghdr->msg_next;
1069 					if (msqkptr->u.msg_first == NULL)
1070 						panic("msg_first/last screwed up #1");
1071 				}
1072 			}
1073 		} else {
1074 			struct msg *previous;
1075 			struct msg **prev;
1076 
1077 			previous = NULL;
1078 			prev = &(msqkptr->u.msg_first);
1079 			while ((msghdr = *prev) != NULL) {
1080 				/*
1081 				 * Is this message's type an exact match or is
1082 				 * this message's type less than or equal to
1083 				 * the absolute value of a negative msgtyp?
1084 				 * Note that the second half of this test can
1085 				 * NEVER be true if msgtyp is positive since
1086 				 * msg_type is always positive!
1087 				 */
1088 
1089 				if (msgtyp == msghdr->msg_type ||
1090 				    msghdr->msg_type <= -msgtyp) {
1091 					DPRINTF(("found message type %ld, "
1092 					    "requested %ld\n",
1093 					    msghdr->msg_type, msgtyp));
1094 					if (msgsz < msghdr->msg_ts &&
1095 					    (msgflg & MSG_NOERROR) == 0) {
1096 						DPRINTF(("requested message "
1097 						    "on the queue is too big "
1098 						    "(want %zu, got %hu)\n",
1099 						    msgsz, msghdr->msg_ts));
1100 						error = E2BIG;
1101 						goto done2;
1102 					}
1103 #ifdef MAC
1104 					error = mac_sysvmsq_check_msgrcv(
1105 					    td->td_ucred, msghdr);
1106 					if (error != 0)
1107 						goto done2;
1108 #endif
1109 					*prev = msghdr->msg_next;
1110 					if (msghdr == msqkptr->u.msg_last) {
1111 						if (previous == NULL) {
1112 							if (prev !=
1113 							    &msqkptr->u.msg_first)
1114 								panic("msg_first/last screwed up #2");
1115 							msqkptr->u.msg_first =
1116 							    NULL;
1117 							msqkptr->u.msg_last =
1118 							    NULL;
1119 						} else {
1120 							if (prev ==
1121 							    &msqkptr->u.msg_first)
1122 								panic("msg_first/last screwed up #3");
1123 							msqkptr->u.msg_last =
1124 							    previous;
1125 						}
1126 					}
1127 					break;
1128 				}
1129 				previous = msghdr;
1130 				prev = &(msghdr->msg_next);
1131 			}
1132 		}
1133 
1134 		/*
1135 		 * We've either extracted the msghdr for the appropriate
1136 		 * message or there isn't one.
1137 		 * If there is one then bail out of this loop.
1138 		 */
1139 
1140 		if (msghdr != NULL)
1141 			break;
1142 
1143 		/*
1144 		 * Hmph!  No message found.  Does the user want to wait?
1145 		 */
1146 
1147 		if ((msgflg & IPC_NOWAIT) != 0) {
1148 			DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1149 			    msgtyp));
1150 			/* The SVID says to return ENOMSG. */
1151 			error = ENOMSG;
1152 			goto done2;
1153 		}
1154 
1155 		/*
1156 		 * Wait for something to happen
1157 		 */
1158 
1159 		DPRINTF(("msgrcv:  goodnight\n"));
1160 		error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1161 		    "msgrcv", 0);
1162 		DPRINTF(("msgrcv:  good morning (error=%d)\n", error));
1163 
1164 		if (error != 0) {
1165 			DPRINTF(("msgrcv:  interrupted system call\n"));
1166 			error = EINTR;
1167 			goto done2;
1168 		}
1169 
1170 		/*
1171 		 * Make sure that the msq queue still exists
1172 		 */
1173 
1174 		if (msqkptr->u.msg_qbytes == 0 ||
1175 		    msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1176 			DPRINTF(("msqid deleted\n"));
1177 			error = EIDRM;
1178 			goto done2;
1179 		}
1180 	}
1181 
1182 	/*
1183 	 * Return the message to the user.
1184 	 *
1185 	 * First, do the bookkeeping (before we risk being interrupted).
1186 	 */
1187 
1188 	msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1189 	msqkptr->u.msg_qnum--;
1190 	msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1191 	msqkptr->u.msg_rtime = time_second;
1192 
1193 	/*
1194 	 * Make msgsz the actual amount that we'll be returning.
1195 	 * Note that this effectively truncates the message if it is too long
1196 	 * (since msgsz is never increased).
1197 	 */
1198 
1199 	DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1200 	    msghdr->msg_ts));
1201 	if (msgsz > msghdr->msg_ts)
1202 		msgsz = msghdr->msg_ts;
1203 	*mtype = msghdr->msg_type;
1204 
1205 	/*
1206 	 * Return the segments to the user
1207 	 */
1208 
1209 	next = msghdr->msg_spot;
1210 	for (len = 0; len < msgsz; len += msginfo.msgssz) {
1211 		size_t tlen;
1212 
1213 		if (msgsz - len > msginfo.msgssz)
1214 			tlen = msginfo.msgssz;
1215 		else
1216 			tlen = msgsz - len;
1217 		if (next <= -1)
1218 			panic("next too low #3");
1219 		if (next >= msginfo.msgseg)
1220 			panic("next out of range #3");
1221 		mtx_unlock(&msq_mtx);
1222 		error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1223 		mtx_lock(&msq_mtx);
1224 		if (error != 0) {
1225 			DPRINTF(("error (%d) copying out message segment\n",
1226 			    error));
1227 			msg_freehdr(msghdr);
1228 			wakeup(msqkptr);
1229 			goto done2;
1230 		}
1231 		msgp = (char *)msgp + tlen;
1232 		next = msgmaps[next].next;
1233 	}
1234 
1235 	/*
1236 	 * Done, return the actual number of bytes copied out.
1237 	 */
1238 
1239 	msg_freehdr(msghdr);
1240 	wakeup(msqkptr);
1241 	td->td_retval[0] = msgsz;
1242 done2:
1243 	mtx_unlock(&msq_mtx);
1244 	return (error);
1245 }
1246 
1247 int
1248 msgrcv(td, uap)
1249 	struct thread *td;
1250 	register struct msgrcv_args *uap;
1251 {
1252 	int error;
1253 	long mtype;
1254 
1255 	DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1256 	    uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1257 
1258 	if ((error = kern_msgrcv(td, uap->msqid,
1259 	    (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1260 	    uap->msgtyp, uap->msgflg, &mtype)) != 0)
1261 		return (error);
1262 	if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1263 		DPRINTF(("error %d copying the message type\n", error));
1264 	return (error);
1265 }
1266 
1267 static int
1268 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1269 {
1270 
1271 	return (SYSCTL_OUT(req, msqids,
1272 	    sizeof(struct msqid_kernel) * msginfo.msgmni));
1273 }
1274 
1275 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1276     "Maximum message size");
1277 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1278     "Number of message queue identifiers");
1279 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1280     "Maximum number of bytes in a queue");
1281 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1282     "Maximum number of messages in the system");
1283 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1284     "Size of a message segment");
1285 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1286     "Number of message segments");
1287 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1288     NULL, 0, sysctl_msqids, "", "Message queue IDs");
1289 
1290 #ifdef COMPAT_FREEBSD32
1291 int
1292 freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap)
1293 {
1294 
1295 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1296     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1297 	switch (uap->which) {
1298 	case 0:
1299 		return (freebsd7_freebsd32_msgctl(td,
1300 		    (struct freebsd7_freebsd32_msgctl_args *)&uap->a2));
1301 	case 2:
1302 		return (freebsd32_msgsnd(td,
1303 		    (struct freebsd32_msgsnd_args *)&uap->a2));
1304 	case 3:
1305 		return (freebsd32_msgrcv(td,
1306 		    (struct freebsd32_msgrcv_args *)&uap->a2));
1307 	default:
1308 		return (msgsys(td, (struct msgsys_args *)uap));
1309 	}
1310 #else
1311 	return (nosys(td, NULL));
1312 #endif
1313 }
1314 
1315 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1316     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1317 int
1318 freebsd7_freebsd32_msgctl(struct thread *td,
1319     struct freebsd7_freebsd32_msgctl_args *uap)
1320 {
1321 	struct msqid_ds msqbuf;
1322 	struct msqid_ds32_old msqbuf32;
1323 	int error;
1324 
1325 	if (uap->cmd == IPC_SET) {
1326 		error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1327 		if (error)
1328 			return (error);
1329 		freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1330 		PTRIN_CP(msqbuf32, msqbuf, msg_first);
1331 		PTRIN_CP(msqbuf32, msqbuf, msg_last);
1332 		CP(msqbuf32, msqbuf, msg_cbytes);
1333 		CP(msqbuf32, msqbuf, msg_qnum);
1334 		CP(msqbuf32, msqbuf, msg_qbytes);
1335 		CP(msqbuf32, msqbuf, msg_lspid);
1336 		CP(msqbuf32, msqbuf, msg_lrpid);
1337 		CP(msqbuf32, msqbuf, msg_stime);
1338 		CP(msqbuf32, msqbuf, msg_rtime);
1339 		CP(msqbuf32, msqbuf, msg_ctime);
1340 	}
1341 	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1342 	if (error)
1343 		return (error);
1344 	if (uap->cmd == IPC_STAT) {
1345 		bzero(&msqbuf32, sizeof(msqbuf32));
1346 		freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1347 		PTROUT_CP(msqbuf, msqbuf32, msg_first);
1348 		PTROUT_CP(msqbuf, msqbuf32, msg_last);
1349 		CP(msqbuf, msqbuf32, msg_cbytes);
1350 		CP(msqbuf, msqbuf32, msg_qnum);
1351 		CP(msqbuf, msqbuf32, msg_qbytes);
1352 		CP(msqbuf, msqbuf32, msg_lspid);
1353 		CP(msqbuf, msqbuf32, msg_lrpid);
1354 		CP(msqbuf, msqbuf32, msg_stime);
1355 		CP(msqbuf, msqbuf32, msg_rtime);
1356 		CP(msqbuf, msqbuf32, msg_ctime);
1357 		error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1358 	}
1359 	return (error);
1360 }
1361 #endif
1362 
1363 int
1364 freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap)
1365 {
1366 	struct msqid_ds msqbuf;
1367 	struct msqid_ds32 msqbuf32;
1368 	int error;
1369 
1370 	if (uap->cmd == IPC_SET) {
1371 		error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1372 		if (error)
1373 			return (error);
1374 		freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1375 		PTRIN_CP(msqbuf32, msqbuf, msg_first);
1376 		PTRIN_CP(msqbuf32, msqbuf, msg_last);
1377 		CP(msqbuf32, msqbuf, msg_cbytes);
1378 		CP(msqbuf32, msqbuf, msg_qnum);
1379 		CP(msqbuf32, msqbuf, msg_qbytes);
1380 		CP(msqbuf32, msqbuf, msg_lspid);
1381 		CP(msqbuf32, msqbuf, msg_lrpid);
1382 		CP(msqbuf32, msqbuf, msg_stime);
1383 		CP(msqbuf32, msqbuf, msg_rtime);
1384 		CP(msqbuf32, msqbuf, msg_ctime);
1385 	}
1386 	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1387 	if (error)
1388 		return (error);
1389 	if (uap->cmd == IPC_STAT) {
1390 		freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1391 		PTROUT_CP(msqbuf, msqbuf32, msg_first);
1392 		PTROUT_CP(msqbuf, msqbuf32, msg_last);
1393 		CP(msqbuf, msqbuf32, msg_cbytes);
1394 		CP(msqbuf, msqbuf32, msg_qnum);
1395 		CP(msqbuf, msqbuf32, msg_qbytes);
1396 		CP(msqbuf, msqbuf32, msg_lspid);
1397 		CP(msqbuf, msqbuf32, msg_lrpid);
1398 		CP(msqbuf, msqbuf32, msg_stime);
1399 		CP(msqbuf, msqbuf32, msg_rtime);
1400 		CP(msqbuf, msqbuf32, msg_ctime);
1401 		error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1402 	}
1403 	return (error);
1404 }
1405 
1406 int
1407 freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap)
1408 {
1409 	const void *msgp;
1410 	long mtype;
1411 	int32_t mtype32;
1412 	int error;
1413 
1414 	msgp = PTRIN(uap->msgp);
1415 	if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0)
1416 		return (error);
1417 	mtype = mtype32;
1418 	return (kern_msgsnd(td, uap->msqid,
1419 	    (const char *)msgp + sizeof(mtype32),
1420 	    uap->msgsz, uap->msgflg, mtype));
1421 }
1422 
1423 int
1424 freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap)
1425 {
1426 	void *msgp;
1427 	long mtype;
1428 	int32_t mtype32;
1429 	int error;
1430 
1431 	msgp = PTRIN(uap->msgp);
1432 	if ((error = kern_msgrcv(td, uap->msqid,
1433 	    (char *)msgp + sizeof(mtype32), uap->msgsz,
1434 	    uap->msgtyp, uap->msgflg, &mtype)) != 0)
1435 		return (error);
1436 	mtype32 = (int32_t)mtype;
1437 	return (copyout(&mtype32, msgp, sizeof(mtype32)));
1438 }
1439 #endif
1440 
1441 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1442     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1443 
1444 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1445 static sy_call_t *msgcalls[] = {
1446 	(sy_call_t *)freebsd7_msgctl, (sy_call_t *)msgget,
1447 	(sy_call_t *)msgsnd, (sy_call_t *)msgrcv
1448 };
1449 
1450 /*
1451  * Entry point for all MSG calls.
1452  */
1453 int
1454 msgsys(td, uap)
1455 	struct thread *td;
1456 	/* XXX actually varargs. */
1457 	struct msgsys_args /* {
1458 		int	which;
1459 		int	a2;
1460 		int	a3;
1461 		int	a4;
1462 		int	a5;
1463 		int	a6;
1464 	} */ *uap;
1465 {
1466 	int error;
1467 
1468 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1469 		return (ENOSYS);
1470 	if (uap->which < 0 ||
1471 	    uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
1472 		return (EINVAL);
1473 	error = (*msgcalls[uap->which])(td, &uap->a2);
1474 	return (error);
1475 }
1476 
1477 #ifndef CP
1478 #define CP(src, dst, fld)	do { (dst).fld = (src).fld; } while (0)
1479 #endif
1480 
1481 #ifndef _SYS_SYSPROTO_H_
1482 struct freebsd7_msgctl_args {
1483 	int	msqid;
1484 	int	cmd;
1485 	struct	msqid_ds_old *buf;
1486 };
1487 #endif
1488 int
1489 freebsd7_msgctl(td, uap)
1490 	struct thread *td;
1491 	struct freebsd7_msgctl_args *uap;
1492 {
1493 	struct msqid_ds_old msqold;
1494 	struct msqid_ds msqbuf;
1495 	int error;
1496 
1497 	DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
1498 	    uap->buf));
1499 	if (uap->cmd == IPC_SET) {
1500 		error = copyin(uap->buf, &msqold, sizeof(msqold));
1501 		if (error)
1502 			return (error);
1503 		ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
1504 		CP(msqold, msqbuf, msg_first);
1505 		CP(msqold, msqbuf, msg_last);
1506 		CP(msqold, msqbuf, msg_cbytes);
1507 		CP(msqold, msqbuf, msg_qnum);
1508 		CP(msqold, msqbuf, msg_qbytes);
1509 		CP(msqold, msqbuf, msg_lspid);
1510 		CP(msqold, msqbuf, msg_lrpid);
1511 		CP(msqold, msqbuf, msg_stime);
1512 		CP(msqold, msqbuf, msg_rtime);
1513 		CP(msqold, msqbuf, msg_ctime);
1514 	}
1515 	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1516 	if (error)
1517 		return (error);
1518 	if (uap->cmd == IPC_STAT) {
1519 		bzero(&msqold, sizeof(msqold));
1520 		ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
1521 		CP(msqbuf, msqold, msg_first);
1522 		CP(msqbuf, msqold, msg_last);
1523 		CP(msqbuf, msqold, msg_cbytes);
1524 		CP(msqbuf, msqold, msg_qnum);
1525 		CP(msqbuf, msqold, msg_qbytes);
1526 		CP(msqbuf, msqold, msg_lspid);
1527 		CP(msqbuf, msqold, msg_lrpid);
1528 		CP(msqbuf, msqold, msg_stime);
1529 		CP(msqbuf, msqold, msg_rtime);
1530 		CP(msqbuf, msqold, msg_ctime);
1531 		error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
1532 	}
1533 	return (error);
1534 }
1535 
1536 #undef CP
1537 
1538 #endif	/* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1539 	   COMPAT_FREEBSD7 */
1540