xref: /freebsd/sys/kern/sysv_msg.c (revision 7aa383846770374466b1dcb2cefd71bde9acf463)
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 	if (msgpool == NULL)
204 		panic("msgpool is NULL");
205 	msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
206 	if (msgmaps == NULL)
207 		panic("msgmaps is NULL");
208 	msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
209 	if (msghdrs == NULL)
210 		panic("msghdrs is NULL");
211 	msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
212 	    M_WAITOK);
213 	if (msqids == NULL)
214 		panic("msqids is NULL");
215 
216 	/*
217 	 * msginfo.msgssz should be a power of two for efficiency reasons.
218 	 * It is also pretty silly if msginfo.msgssz is less than 8
219 	 * or greater than about 256 so ...
220 	 */
221 
222 	i = 8;
223 	while (i < 1024 && i != msginfo.msgssz)
224 		i <<= 1;
225     	if (i != msginfo.msgssz) {
226 		DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
227 		    msginfo.msgssz));
228 		panic("msginfo.msgssz not a small power of 2");
229 	}
230 
231 	if (msginfo.msgseg > 32767) {
232 		DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
233 		panic("msginfo.msgseg > 32767");
234 	}
235 
236 	if (msgmaps == NULL)
237 		panic("msgmaps is NULL");
238 
239 	for (i = 0; i < msginfo.msgseg; i++) {
240 		if (i > 0)
241 			msgmaps[i-1].next = i;
242 		msgmaps[i].next = -1;	/* implies entry is available */
243 	}
244 	free_msgmaps = 0;
245 	nfree_msgmaps = msginfo.msgseg;
246 
247 	if (msghdrs == NULL)
248 		panic("msghdrs is NULL");
249 
250 	for (i = 0; i < msginfo.msgtql; i++) {
251 		msghdrs[i].msg_type = 0;
252 		if (i > 0)
253 			msghdrs[i-1].msg_next = &msghdrs[i];
254 		msghdrs[i].msg_next = NULL;
255 #ifdef MAC
256 		mac_sysvmsg_init(&msghdrs[i]);
257 #endif
258     	}
259 	free_msghdrs = &msghdrs[0];
260 
261 	if (msqids == NULL)
262 		panic("msqids is NULL");
263 
264 	for (i = 0; i < msginfo.msgmni; i++) {
265 		msqids[i].u.msg_qbytes = 0;	/* implies entry is available */
266 		msqids[i].u.msg_perm.seq = 0;	/* reset to a known value */
267 		msqids[i].u.msg_perm.mode = 0;
268 #ifdef MAC
269 		mac_sysvmsq_init(&msqids[i]);
270 #endif
271 	}
272 	mtx_init(&msq_mtx, "msq", NULL, MTX_DEF);
273 
274 	error = syscall_helper_register(msg_syscalls);
275 	if (error != 0)
276 		return (error);
277 #ifdef COMPAT_FREEBSD32
278 	error = syscall32_helper_register(msg32_syscalls);
279 	if (error != 0)
280 		return (error);
281 #endif
282 	return (0);
283 }
284 
285 static int
286 msgunload()
287 {
288 	struct msqid_kernel *msqkptr;
289 	int msqid;
290 #ifdef MAC
291 	int i;
292 #endif
293 
294 	syscall_helper_unregister(msg_syscalls);
295 #ifdef COMPAT_FREEBSD32
296 	syscall32_helper_unregister(msg32_syscalls);
297 #endif
298 
299 	for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
300 		/*
301 		 * Look for an unallocated and unlocked msqid_ds.
302 		 * msqid_ds's can be locked by msgsnd or msgrcv while
303 		 * they are copying the message in/out.  We can't
304 		 * re-use the entry until they release it.
305 		 */
306 		msqkptr = &msqids[msqid];
307 		if (msqkptr->u.msg_qbytes != 0 ||
308 		    (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
309 			break;
310 	}
311 	if (msqid != msginfo.msgmni)
312 		return (EBUSY);
313 
314 #ifdef MAC
315 	for (i = 0; i < msginfo.msgtql; i++)
316 		mac_sysvmsg_destroy(&msghdrs[i]);
317 	for (msqid = 0; msqid < msginfo.msgmni; msqid++)
318 		mac_sysvmsq_destroy(&msqids[msqid]);
319 #endif
320 	free(msgpool, M_MSG);
321 	free(msgmaps, M_MSG);
322 	free(msghdrs, M_MSG);
323 	free(msqids, M_MSG);
324 	mtx_destroy(&msq_mtx);
325 	return (0);
326 }
327 
328 
329 static int
330 sysvmsg_modload(struct module *module, int cmd, void *arg)
331 {
332 	int error = 0;
333 
334 	switch (cmd) {
335 	case MOD_LOAD:
336 		error = msginit();
337 		if (error != 0)
338 			msgunload();
339 		break;
340 	case MOD_UNLOAD:
341 		error = msgunload();
342 		break;
343 	case MOD_SHUTDOWN:
344 		break;
345 	default:
346 		error = EINVAL;
347 		break;
348 	}
349 	return (error);
350 }
351 
352 static moduledata_t sysvmsg_mod = {
353 	"sysvmsg",
354 	&sysvmsg_modload,
355 	NULL
356 };
357 
358 DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
359 MODULE_VERSION(sysvmsg, 1);
360 
361 static void
362 msg_freehdr(msghdr)
363 	struct msg *msghdr;
364 {
365 	while (msghdr->msg_ts > 0) {
366 		short next;
367 		if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
368 			panic("msghdr->msg_spot out of range");
369 		next = msgmaps[msghdr->msg_spot].next;
370 		msgmaps[msghdr->msg_spot].next = free_msgmaps;
371 		free_msgmaps = msghdr->msg_spot;
372 		nfree_msgmaps++;
373 		msghdr->msg_spot = next;
374 		if (msghdr->msg_ts >= msginfo.msgssz)
375 			msghdr->msg_ts -= msginfo.msgssz;
376 		else
377 			msghdr->msg_ts = 0;
378 	}
379 	if (msghdr->msg_spot != -1)
380 		panic("msghdr->msg_spot != -1");
381 	msghdr->msg_next = free_msghdrs;
382 	free_msghdrs = msghdr;
383 #ifdef MAC
384 	mac_sysvmsg_cleanup(msghdr);
385 #endif
386 }
387 
388 #ifndef _SYS_SYSPROTO_H_
389 struct msgctl_args {
390 	int	msqid;
391 	int	cmd;
392 	struct	msqid_ds *buf;
393 };
394 #endif
395 int
396 msgctl(td, uap)
397 	struct thread *td;
398 	register struct msgctl_args *uap;
399 {
400 	int msqid = uap->msqid;
401 	int cmd = uap->cmd;
402 	struct msqid_ds msqbuf;
403 	int error;
404 
405 	DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
406 	if (cmd == IPC_SET &&
407 	    (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
408 		return (error);
409 	error = kern_msgctl(td, msqid, cmd, &msqbuf);
410 	if (cmd == IPC_STAT && error == 0)
411 		error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
412 	return (error);
413 }
414 
415 int
416 kern_msgctl(td, msqid, cmd, msqbuf)
417 	struct thread *td;
418 	int msqid;
419 	int cmd;
420 	struct msqid_ds *msqbuf;
421 {
422 	int rval, error, msqix;
423 	register struct msqid_kernel *msqkptr;
424 
425 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
426 		return (ENOSYS);
427 
428 	msqix = IPCID_TO_IX(msqid);
429 
430 	if (msqix < 0 || msqix >= msginfo.msgmni) {
431 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
432 		    msginfo.msgmni));
433 		return (EINVAL);
434 	}
435 
436 	msqkptr = &msqids[msqix];
437 
438 	mtx_lock(&msq_mtx);
439 	if (msqkptr->u.msg_qbytes == 0) {
440 		DPRINTF(("no such msqid\n"));
441 		error = EINVAL;
442 		goto done2;
443 	}
444 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
445 		DPRINTF(("wrong sequence number\n"));
446 		error = EINVAL;
447 		goto done2;
448 	}
449 #ifdef MAC
450 	error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
451 	if (error != 0)
452 		goto done2;
453 #endif
454 
455 	error = 0;
456 	rval = 0;
457 
458 	switch (cmd) {
459 
460 	case IPC_RMID:
461 	{
462 		struct msg *msghdr;
463 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
464 			goto done2;
465 
466 #ifdef MAC
467 		/*
468 		 * Check that the thread has MAC access permissions to
469 		 * individual msghdrs.  Note: We need to do this in a
470 		 * separate loop because the actual loop alters the
471 		 * msq/msghdr info as it progresses, and there is no going
472 		 * back if half the way through we discover that the
473 		 * thread cannot free a certain msghdr.  The msq will get
474 		 * into an inconsistent state.
475 		 */
476 		for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
477 		    msghdr = msghdr->msg_next) {
478 			error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
479 			if (error != 0)
480 				goto done2;
481 		}
482 #endif
483 
484 		/* Free the message headers */
485 		msghdr = msqkptr->u.msg_first;
486 		while (msghdr != NULL) {
487 			struct msg *msghdr_tmp;
488 
489 			/* Free the segments of each message */
490 			msqkptr->u.msg_cbytes -= msghdr->msg_ts;
491 			msqkptr->u.msg_qnum--;
492 			msghdr_tmp = msghdr;
493 			msghdr = msghdr->msg_next;
494 			msg_freehdr(msghdr_tmp);
495 		}
496 
497 		if (msqkptr->u.msg_cbytes != 0)
498 			panic("msg_cbytes is screwed up");
499 		if (msqkptr->u.msg_qnum != 0)
500 			panic("msg_qnum is screwed up");
501 
502 		msqkptr->u.msg_qbytes = 0;	/* Mark it as free */
503 
504 #ifdef MAC
505 		mac_sysvmsq_cleanup(msqkptr);
506 #endif
507 
508 		wakeup(msqkptr);
509 	}
510 
511 		break;
512 
513 	case IPC_SET:
514 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
515 			goto done2;
516 		if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
517 			error = priv_check(td, PRIV_IPC_MSGSIZE);
518 			if (error)
519 				goto done2;
520 		}
521 		if (msqbuf->msg_qbytes > msginfo.msgmnb) {
522 			DPRINTF(("can't increase msg_qbytes beyond %d"
523 			    "(truncating)\n", msginfo.msgmnb));
524 			msqbuf->msg_qbytes = msginfo.msgmnb;	/* silently restrict qbytes to system limit */
525 		}
526 		if (msqbuf->msg_qbytes == 0) {
527 			DPRINTF(("can't reduce msg_qbytes to 0\n"));
528 			error = EINVAL;		/* non-standard errno! */
529 			goto done2;
530 		}
531 		msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid;	/* change the owner */
532 		msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid;	/* change the owner */
533 		msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
534 		    (msqbuf->msg_perm.mode & 0777);
535 		msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
536 		msqkptr->u.msg_ctime = time_second;
537 		break;
538 
539 	case IPC_STAT:
540 		if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
541 			DPRINTF(("requester doesn't have read access\n"));
542 			goto done2;
543 		}
544 		*msqbuf = msqkptr->u;
545 		break;
546 
547 	default:
548 		DPRINTF(("invalid command %d\n", cmd));
549 		error = EINVAL;
550 		goto done2;
551 	}
552 
553 	if (error == 0)
554 		td->td_retval[0] = rval;
555 done2:
556 	mtx_unlock(&msq_mtx);
557 	return (error);
558 }
559 
560 #ifndef _SYS_SYSPROTO_H_
561 struct msgget_args {
562 	key_t	key;
563 	int	msgflg;
564 };
565 #endif
566 int
567 msgget(td, uap)
568 	struct thread *td;
569 	register struct msgget_args *uap;
570 {
571 	int msqid, error = 0;
572 	int key = uap->key;
573 	int msgflg = uap->msgflg;
574 	struct ucred *cred = td->td_ucred;
575 	register struct msqid_kernel *msqkptr = NULL;
576 
577 	DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
578 
579 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
580 		return (ENOSYS);
581 
582 	mtx_lock(&msq_mtx);
583 	if (key != IPC_PRIVATE) {
584 		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
585 			msqkptr = &msqids[msqid];
586 			if (msqkptr->u.msg_qbytes != 0 &&
587 			    msqkptr->u.msg_perm.key == key)
588 				break;
589 		}
590 		if (msqid < msginfo.msgmni) {
591 			DPRINTF(("found public key\n"));
592 			if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
593 				DPRINTF(("not exclusive\n"));
594 				error = EEXIST;
595 				goto done2;
596 			}
597 			if ((error = ipcperm(td, &msqkptr->u.msg_perm,
598 			    msgflg & 0700))) {
599 				DPRINTF(("requester doesn't have 0%o access\n",
600 				    msgflg & 0700));
601 				goto done2;
602 			}
603 #ifdef MAC
604 			error = mac_sysvmsq_check_msqget(cred, msqkptr);
605 			if (error != 0)
606 				goto done2;
607 #endif
608 			goto found;
609 		}
610 	}
611 
612 	DPRINTF(("need to allocate the msqid_ds\n"));
613 	if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
614 		for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
615 			/*
616 			 * Look for an unallocated and unlocked msqid_ds.
617 			 * msqid_ds's can be locked by msgsnd or msgrcv while
618 			 * they are copying the message in/out.  We can't
619 			 * re-use the entry until they release it.
620 			 */
621 			msqkptr = &msqids[msqid];
622 			if (msqkptr->u.msg_qbytes == 0 &&
623 			    (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
624 				break;
625 		}
626 		if (msqid == msginfo.msgmni) {
627 			DPRINTF(("no more msqid_ds's available\n"));
628 			error = ENOSPC;
629 			goto done2;
630 		}
631 		DPRINTF(("msqid %d is available\n", msqid));
632 		msqkptr->u.msg_perm.key = key;
633 		msqkptr->u.msg_perm.cuid = cred->cr_uid;
634 		msqkptr->u.msg_perm.uid = cred->cr_uid;
635 		msqkptr->u.msg_perm.cgid = cred->cr_gid;
636 		msqkptr->u.msg_perm.gid = cred->cr_gid;
637 		msqkptr->u.msg_perm.mode = (msgflg & 0777);
638 		/* Make sure that the returned msqid is unique */
639 		msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
640 		msqkptr->u.msg_first = NULL;
641 		msqkptr->u.msg_last = NULL;
642 		msqkptr->u.msg_cbytes = 0;
643 		msqkptr->u.msg_qnum = 0;
644 		msqkptr->u.msg_qbytes = msginfo.msgmnb;
645 		msqkptr->u.msg_lspid = 0;
646 		msqkptr->u.msg_lrpid = 0;
647 		msqkptr->u.msg_stime = 0;
648 		msqkptr->u.msg_rtime = 0;
649 		msqkptr->u.msg_ctime = time_second;
650 #ifdef MAC
651 		mac_sysvmsq_create(cred, msqkptr);
652 #endif
653 	} else {
654 		DPRINTF(("didn't find it and wasn't asked to create it\n"));
655 		error = ENOENT;
656 		goto done2;
657 	}
658 
659 found:
660 	/* Construct the unique msqid */
661 	td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
662 done2:
663 	mtx_unlock(&msq_mtx);
664 	return (error);
665 }
666 
667 #ifndef _SYS_SYSPROTO_H_
668 struct msgsnd_args {
669 	int	msqid;
670 	const void	*msgp;
671 	size_t	msgsz;
672 	int	msgflg;
673 };
674 #endif
675 int
676 kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
677 	struct thread *td;
678 	int msqid;
679 	const void *msgp;	/* XXX msgp is actually mtext. */
680 	size_t msgsz;
681 	int msgflg;
682 	long mtype;
683 {
684 	int msqix, segs_needed, error = 0;
685 	register struct msqid_kernel *msqkptr;
686 	register struct msg *msghdr;
687 	short next;
688 
689 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
690 		return (ENOSYS);
691 
692 	mtx_lock(&msq_mtx);
693 	msqix = IPCID_TO_IX(msqid);
694 
695 	if (msqix < 0 || msqix >= msginfo.msgmni) {
696 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
697 		    msginfo.msgmni));
698 		error = EINVAL;
699 		goto done2;
700 	}
701 
702 	msqkptr = &msqids[msqix];
703 	if (msqkptr->u.msg_qbytes == 0) {
704 		DPRINTF(("no such message queue id\n"));
705 		error = EINVAL;
706 		goto done2;
707 	}
708 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
709 		DPRINTF(("wrong sequence number\n"));
710 		error = EINVAL;
711 		goto done2;
712 	}
713 
714 	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
715 		DPRINTF(("requester doesn't have write access\n"));
716 		goto done2;
717 	}
718 
719 #ifdef MAC
720 	error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
721 	if (error != 0)
722 		goto done2;
723 #endif
724 
725 	segs_needed = (msgsz + msginfo.msgssz - 1) / msginfo.msgssz;
726 	DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
727 	    msginfo.msgssz, segs_needed));
728 	for (;;) {
729 		int need_more_resources = 0;
730 
731 		/*
732 		 * check msgsz
733 		 * (inside this loop in case msg_qbytes changes while we sleep)
734 		 */
735 
736 		if (msgsz > msqkptr->u.msg_qbytes) {
737 			DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
738 			error = EINVAL;
739 			goto done2;
740 		}
741 
742 		if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
743 			DPRINTF(("msqid is locked\n"));
744 			need_more_resources = 1;
745 		}
746 		if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
747 			DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
748 			need_more_resources = 1;
749 		}
750 		if (segs_needed > nfree_msgmaps) {
751 			DPRINTF(("segs_needed > nfree_msgmaps\n"));
752 			need_more_resources = 1;
753 		}
754 		if (free_msghdrs == NULL) {
755 			DPRINTF(("no more msghdrs\n"));
756 			need_more_resources = 1;
757 		}
758 
759 		if (need_more_resources) {
760 			int we_own_it;
761 
762 			if ((msgflg & IPC_NOWAIT) != 0) {
763 				DPRINTF(("need more resources but caller "
764 				    "doesn't want to wait\n"));
765 				error = EAGAIN;
766 				goto done2;
767 			}
768 
769 			if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
770 				DPRINTF(("we don't own the msqid_ds\n"));
771 				we_own_it = 0;
772 			} else {
773 				/* Force later arrivals to wait for our
774 				   request */
775 				DPRINTF(("we own the msqid_ds\n"));
776 				msqkptr->u.msg_perm.mode |= MSG_LOCKED;
777 				we_own_it = 1;
778 			}
779 			DPRINTF(("msgsnd:  goodnight\n"));
780 			error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
781 			    "msgsnd", hz);
782 			DPRINTF(("msgsnd:  good morning, error=%d\n", error));
783 			if (we_own_it)
784 				msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
785 			if (error == EWOULDBLOCK) {
786 				DPRINTF(("msgsnd:  timed out\n"));
787 				continue;
788 			}
789 			if (error != 0) {
790 				DPRINTF(("msgsnd:  interrupted system call\n"));
791 				error = EINTR;
792 				goto done2;
793 			}
794 
795 			/*
796 			 * Make sure that the msq queue still exists
797 			 */
798 
799 			if (msqkptr->u.msg_qbytes == 0) {
800 				DPRINTF(("msqid deleted\n"));
801 				error = EIDRM;
802 				goto done2;
803 			}
804 
805 		} else {
806 			DPRINTF(("got all the resources that we need\n"));
807 			break;
808 		}
809 	}
810 
811 	/*
812 	 * We have the resources that we need.
813 	 * Make sure!
814 	 */
815 
816 	if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
817 		panic("msg_perm.mode & MSG_LOCKED");
818 	if (segs_needed > nfree_msgmaps)
819 		panic("segs_needed > nfree_msgmaps");
820 	if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
821 		panic("msgsz + msg_cbytes > msg_qbytes");
822 	if (free_msghdrs == NULL)
823 		panic("no more msghdrs");
824 
825 	/*
826 	 * Re-lock the msqid_ds in case we page-fault when copying in the
827 	 * message
828 	 */
829 
830 	if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
831 		panic("msqid_ds is already locked");
832 	msqkptr->u.msg_perm.mode |= MSG_LOCKED;
833 
834 	/*
835 	 * Allocate a message header
836 	 */
837 
838 	msghdr = free_msghdrs;
839 	free_msghdrs = msghdr->msg_next;
840 	msghdr->msg_spot = -1;
841 	msghdr->msg_ts = msgsz;
842 	msghdr->msg_type = mtype;
843 #ifdef MAC
844 	/*
845 	 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
846 	 * immediately?  Or, should it be checked just before the msg is
847 	 * enqueued in the msgq (as it is done now)?
848 	 */
849 	mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
850 #endif
851 
852 	/*
853 	 * Allocate space for the message
854 	 */
855 
856 	while (segs_needed > 0) {
857 		if (nfree_msgmaps <= 0)
858 			panic("not enough msgmaps");
859 		if (free_msgmaps == -1)
860 			panic("nil free_msgmaps");
861 		next = free_msgmaps;
862 		if (next <= -1)
863 			panic("next too low #1");
864 		if (next >= msginfo.msgseg)
865 			panic("next out of range #1");
866 		DPRINTF(("allocating segment %d to message\n", next));
867 		free_msgmaps = msgmaps[next].next;
868 		nfree_msgmaps--;
869 		msgmaps[next].next = msghdr->msg_spot;
870 		msghdr->msg_spot = next;
871 		segs_needed--;
872 	}
873 
874 	/*
875 	 * Validate the message type
876 	 */
877 
878 	if (msghdr->msg_type < 1) {
879 		msg_freehdr(msghdr);
880 		msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
881 		wakeup(msqkptr);
882 		DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
883 		error = EINVAL;
884 		goto done2;
885 	}
886 
887 	/*
888 	 * Copy in the message body
889 	 */
890 
891 	next = msghdr->msg_spot;
892 	while (msgsz > 0) {
893 		size_t tlen;
894 		if (msgsz > msginfo.msgssz)
895 			tlen = msginfo.msgssz;
896 		else
897 			tlen = msgsz;
898 		if (next <= -1)
899 			panic("next too low #2");
900 		if (next >= msginfo.msgseg)
901 			panic("next out of range #2");
902 		mtx_unlock(&msq_mtx);
903 		if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
904 		    tlen)) != 0) {
905 			mtx_lock(&msq_mtx);
906 			DPRINTF(("error %d copying in message segment\n",
907 			    error));
908 			msg_freehdr(msghdr);
909 			msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
910 			wakeup(msqkptr);
911 			goto done2;
912 		}
913 		mtx_lock(&msq_mtx);
914 		msgsz -= tlen;
915 		msgp = (const char *)msgp + tlen;
916 		next = msgmaps[next].next;
917 	}
918 	if (next != -1)
919 		panic("didn't use all the msg segments");
920 
921 	/*
922 	 * We've got the message.  Unlock the msqid_ds.
923 	 */
924 
925 	msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
926 
927 	/*
928 	 * Make sure that the msqid_ds is still allocated.
929 	 */
930 
931 	if (msqkptr->u.msg_qbytes == 0) {
932 		msg_freehdr(msghdr);
933 		wakeup(msqkptr);
934 		error = EIDRM;
935 		goto done2;
936 	}
937 
938 #ifdef MAC
939 	/*
940 	 * Note: Since the task/thread allocates the msghdr and usually
941 	 * primes it with its own MAC label, for a majority of policies, it
942 	 * won't be necessary to check whether the msghdr has access
943 	 * permissions to the msgq.  The mac_sysvmsq_check_msqsnd check would
944 	 * suffice in that case.  However, this hook may be required where
945 	 * individual policies derive a non-identical label for the msghdr
946 	 * from the current thread label and may want to check the msghdr
947 	 * enqueue permissions, along with read/write permissions to the
948 	 * msgq.
949 	 */
950 	error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
951 	if (error != 0) {
952 		msg_freehdr(msghdr);
953 		wakeup(msqkptr);
954 		goto done2;
955 	}
956 #endif
957 
958 	/*
959 	 * Put the message into the queue
960 	 */
961 	if (msqkptr->u.msg_first == NULL) {
962 		msqkptr->u.msg_first = msghdr;
963 		msqkptr->u.msg_last = msghdr;
964 	} else {
965 		msqkptr->u.msg_last->msg_next = msghdr;
966 		msqkptr->u.msg_last = msghdr;
967 	}
968 	msqkptr->u.msg_last->msg_next = NULL;
969 
970 	msqkptr->u.msg_cbytes += msghdr->msg_ts;
971 	msqkptr->u.msg_qnum++;
972 	msqkptr->u.msg_lspid = td->td_proc->p_pid;
973 	msqkptr->u.msg_stime = time_second;
974 
975 	wakeup(msqkptr);
976 	td->td_retval[0] = 0;
977 done2:
978 	mtx_unlock(&msq_mtx);
979 	return (error);
980 }
981 
982 int
983 msgsnd(td, uap)
984 	struct thread *td;
985 	register struct msgsnd_args *uap;
986 {
987 	int error;
988 	long mtype;
989 
990 	DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
991 	    uap->msgsz, uap->msgflg));
992 
993 	if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
994 		DPRINTF(("error %d copying the message type\n", error));
995 		return (error);
996 	}
997 	return (kern_msgsnd(td, uap->msqid,
998 	    (const char *)uap->msgp + sizeof(mtype),
999 	    uap->msgsz, uap->msgflg, mtype));
1000 }
1001 
1002 #ifndef _SYS_SYSPROTO_H_
1003 struct msgrcv_args {
1004 	int	msqid;
1005 	void	*msgp;
1006 	size_t	msgsz;
1007 	long	msgtyp;
1008 	int	msgflg;
1009 };
1010 #endif
1011 int
1012 kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
1013 	struct thread *td;
1014 	int msqid;
1015 	void *msgp;	/* XXX msgp is actually mtext. */
1016 	size_t msgsz;
1017 	long msgtyp;
1018 	int msgflg;
1019 	long *mtype;
1020 {
1021 	size_t len;
1022 	register struct msqid_kernel *msqkptr;
1023 	register struct msg *msghdr;
1024 	int msqix, error = 0;
1025 	short next;
1026 
1027 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1028 		return (ENOSYS);
1029 
1030 	msqix = IPCID_TO_IX(msqid);
1031 
1032 	if (msqix < 0 || msqix >= msginfo.msgmni) {
1033 		DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
1034 		    msginfo.msgmni));
1035 		return (EINVAL);
1036 	}
1037 
1038 	msqkptr = &msqids[msqix];
1039 	mtx_lock(&msq_mtx);
1040 	if (msqkptr->u.msg_qbytes == 0) {
1041 		DPRINTF(("no such message queue id\n"));
1042 		error = EINVAL;
1043 		goto done2;
1044 	}
1045 	if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1046 		DPRINTF(("wrong sequence number\n"));
1047 		error = EINVAL;
1048 		goto done2;
1049 	}
1050 
1051 	if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1052 		DPRINTF(("requester doesn't have read access\n"));
1053 		goto done2;
1054 	}
1055 
1056 #ifdef MAC
1057 	error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
1058 	if (error != 0)
1059 		goto done2;
1060 #endif
1061 
1062 	msghdr = NULL;
1063 	while (msghdr == NULL) {
1064 		if (msgtyp == 0) {
1065 			msghdr = msqkptr->u.msg_first;
1066 			if (msghdr != NULL) {
1067 				if (msgsz < msghdr->msg_ts &&
1068 				    (msgflg & MSG_NOERROR) == 0) {
1069 					DPRINTF(("first message on the queue "
1070 					    "is too big (want %zu, got %d)\n",
1071 					    msgsz, msghdr->msg_ts));
1072 					error = E2BIG;
1073 					goto done2;
1074 				}
1075 #ifdef MAC
1076 				error = mac_sysvmsq_check_msgrcv(td->td_ucred,
1077 				    msghdr);
1078 				if (error != 0)
1079 					goto done2;
1080 #endif
1081 				if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1082 					msqkptr->u.msg_first = NULL;
1083 					msqkptr->u.msg_last = NULL;
1084 				} else {
1085 					msqkptr->u.msg_first = msghdr->msg_next;
1086 					if (msqkptr->u.msg_first == NULL)
1087 						panic("msg_first/last screwed up #1");
1088 				}
1089 			}
1090 		} else {
1091 			struct msg *previous;
1092 			struct msg **prev;
1093 
1094 			previous = NULL;
1095 			prev = &(msqkptr->u.msg_first);
1096 			while ((msghdr = *prev) != NULL) {
1097 				/*
1098 				 * Is this message's type an exact match or is
1099 				 * this message's type less than or equal to
1100 				 * the absolute value of a negative msgtyp?
1101 				 * Note that the second half of this test can
1102 				 * NEVER be true if msgtyp is positive since
1103 				 * msg_type is always positive!
1104 				 */
1105 
1106 				if (msgtyp == msghdr->msg_type ||
1107 				    msghdr->msg_type <= -msgtyp) {
1108 					DPRINTF(("found message type %ld, "
1109 					    "requested %ld\n",
1110 					    msghdr->msg_type, msgtyp));
1111 					if (msgsz < msghdr->msg_ts &&
1112 					    (msgflg & MSG_NOERROR) == 0) {
1113 						DPRINTF(("requested message "
1114 						    "on the queue is too big "
1115 						    "(want %zu, got %hu)\n",
1116 						    msgsz, msghdr->msg_ts));
1117 						error = E2BIG;
1118 						goto done2;
1119 					}
1120 #ifdef MAC
1121 					error = mac_sysvmsq_check_msgrcv(
1122 					    td->td_ucred, msghdr);
1123 					if (error != 0)
1124 						goto done2;
1125 #endif
1126 					*prev = msghdr->msg_next;
1127 					if (msghdr == msqkptr->u.msg_last) {
1128 						if (previous == NULL) {
1129 							if (prev !=
1130 							    &msqkptr->u.msg_first)
1131 								panic("msg_first/last screwed up #2");
1132 							msqkptr->u.msg_first =
1133 							    NULL;
1134 							msqkptr->u.msg_last =
1135 							    NULL;
1136 						} else {
1137 							if (prev ==
1138 							    &msqkptr->u.msg_first)
1139 								panic("msg_first/last screwed up #3");
1140 							msqkptr->u.msg_last =
1141 							    previous;
1142 						}
1143 					}
1144 					break;
1145 				}
1146 				previous = msghdr;
1147 				prev = &(msghdr->msg_next);
1148 			}
1149 		}
1150 
1151 		/*
1152 		 * We've either extracted the msghdr for the appropriate
1153 		 * message or there isn't one.
1154 		 * If there is one then bail out of this loop.
1155 		 */
1156 
1157 		if (msghdr != NULL)
1158 			break;
1159 
1160 		/*
1161 		 * Hmph!  No message found.  Does the user want to wait?
1162 		 */
1163 
1164 		if ((msgflg & IPC_NOWAIT) != 0) {
1165 			DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1166 			    msgtyp));
1167 			/* The SVID says to return ENOMSG. */
1168 			error = ENOMSG;
1169 			goto done2;
1170 		}
1171 
1172 		/*
1173 		 * Wait for something to happen
1174 		 */
1175 
1176 		DPRINTF(("msgrcv:  goodnight\n"));
1177 		error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1178 		    "msgrcv", 0);
1179 		DPRINTF(("msgrcv:  good morning (error=%d)\n", error));
1180 
1181 		if (error != 0) {
1182 			DPRINTF(("msgrcv:  interrupted system call\n"));
1183 			error = EINTR;
1184 			goto done2;
1185 		}
1186 
1187 		/*
1188 		 * Make sure that the msq queue still exists
1189 		 */
1190 
1191 		if (msqkptr->u.msg_qbytes == 0 ||
1192 		    msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1193 			DPRINTF(("msqid deleted\n"));
1194 			error = EIDRM;
1195 			goto done2;
1196 		}
1197 	}
1198 
1199 	/*
1200 	 * Return the message to the user.
1201 	 *
1202 	 * First, do the bookkeeping (before we risk being interrupted).
1203 	 */
1204 
1205 	msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1206 	msqkptr->u.msg_qnum--;
1207 	msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1208 	msqkptr->u.msg_rtime = time_second;
1209 
1210 	/*
1211 	 * Make msgsz the actual amount that we'll be returning.
1212 	 * Note that this effectively truncates the message if it is too long
1213 	 * (since msgsz is never increased).
1214 	 */
1215 
1216 	DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1217 	    msghdr->msg_ts));
1218 	if (msgsz > msghdr->msg_ts)
1219 		msgsz = msghdr->msg_ts;
1220 	*mtype = msghdr->msg_type;
1221 
1222 	/*
1223 	 * Return the segments to the user
1224 	 */
1225 
1226 	next = msghdr->msg_spot;
1227 	for (len = 0; len < msgsz; len += msginfo.msgssz) {
1228 		size_t tlen;
1229 
1230 		if (msgsz - len > msginfo.msgssz)
1231 			tlen = msginfo.msgssz;
1232 		else
1233 			tlen = msgsz - len;
1234 		if (next <= -1)
1235 			panic("next too low #3");
1236 		if (next >= msginfo.msgseg)
1237 			panic("next out of range #3");
1238 		mtx_unlock(&msq_mtx);
1239 		error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1240 		mtx_lock(&msq_mtx);
1241 		if (error != 0) {
1242 			DPRINTF(("error (%d) copying out message segment\n",
1243 			    error));
1244 			msg_freehdr(msghdr);
1245 			wakeup(msqkptr);
1246 			goto done2;
1247 		}
1248 		msgp = (char *)msgp + tlen;
1249 		next = msgmaps[next].next;
1250 	}
1251 
1252 	/*
1253 	 * Done, return the actual number of bytes copied out.
1254 	 */
1255 
1256 	msg_freehdr(msghdr);
1257 	wakeup(msqkptr);
1258 	td->td_retval[0] = msgsz;
1259 done2:
1260 	mtx_unlock(&msq_mtx);
1261 	return (error);
1262 }
1263 
1264 int
1265 msgrcv(td, uap)
1266 	struct thread *td;
1267 	register struct msgrcv_args *uap;
1268 {
1269 	int error;
1270 	long mtype;
1271 
1272 	DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1273 	    uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1274 
1275 	if ((error = kern_msgrcv(td, uap->msqid,
1276 	    (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1277 	    uap->msgtyp, uap->msgflg, &mtype)) != 0)
1278 		return (error);
1279 	if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1280 		DPRINTF(("error %d copying the message type\n", error));
1281 	return (error);
1282 }
1283 
1284 static int
1285 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1286 {
1287 
1288 	return (SYSCTL_OUT(req, msqids,
1289 	    sizeof(struct msqid_kernel) * msginfo.msgmni));
1290 }
1291 
1292 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1293     "Maximum message size");
1294 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1295     "Number of message queue identifiers");
1296 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1297     "Maximum number of bytes in a queue");
1298 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1299     "Maximum number of messages in the system");
1300 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1301     "Size of a message segment");
1302 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1303     "Number of message segments");
1304 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids, CTLFLAG_RD,
1305     NULL, 0, sysctl_msqids, "", "Message queue IDs");
1306 
1307 #ifdef COMPAT_FREEBSD32
1308 int
1309 freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap)
1310 {
1311 
1312 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1313     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1314 	switch (uap->which) {
1315 	case 0:
1316 		return (freebsd7_freebsd32_msgctl(td,
1317 		    (struct freebsd7_freebsd32_msgctl_args *)&uap->a2));
1318 	case 2:
1319 		return (freebsd32_msgsnd(td,
1320 		    (struct freebsd32_msgsnd_args *)&uap->a2));
1321 	case 3:
1322 		return (freebsd32_msgrcv(td,
1323 		    (struct freebsd32_msgrcv_args *)&uap->a2));
1324 	default:
1325 		return (msgsys(td, (struct msgsys_args *)uap));
1326 	}
1327 #else
1328 	return (nosys(td, NULL));
1329 #endif
1330 }
1331 
1332 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1333     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1334 int
1335 freebsd7_freebsd32_msgctl(struct thread *td,
1336     struct freebsd7_freebsd32_msgctl_args *uap)
1337 {
1338 	struct msqid_ds msqbuf;
1339 	struct msqid_ds32_old msqbuf32;
1340 	int error;
1341 
1342 	if (uap->cmd == IPC_SET) {
1343 		error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1344 		if (error)
1345 			return (error);
1346 		freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1347 		PTRIN_CP(msqbuf32, msqbuf, msg_first);
1348 		PTRIN_CP(msqbuf32, msqbuf, msg_last);
1349 		CP(msqbuf32, msqbuf, msg_cbytes);
1350 		CP(msqbuf32, msqbuf, msg_qnum);
1351 		CP(msqbuf32, msqbuf, msg_qbytes);
1352 		CP(msqbuf32, msqbuf, msg_lspid);
1353 		CP(msqbuf32, msqbuf, msg_lrpid);
1354 		CP(msqbuf32, msqbuf, msg_stime);
1355 		CP(msqbuf32, msqbuf, msg_rtime);
1356 		CP(msqbuf32, msqbuf, msg_ctime);
1357 	}
1358 	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1359 	if (error)
1360 		return (error);
1361 	if (uap->cmd == IPC_STAT) {
1362 		bzero(&msqbuf32, sizeof(msqbuf32));
1363 		freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1364 		PTROUT_CP(msqbuf, msqbuf32, msg_first);
1365 		PTROUT_CP(msqbuf, msqbuf32, msg_last);
1366 		CP(msqbuf, msqbuf32, msg_cbytes);
1367 		CP(msqbuf, msqbuf32, msg_qnum);
1368 		CP(msqbuf, msqbuf32, msg_qbytes);
1369 		CP(msqbuf, msqbuf32, msg_lspid);
1370 		CP(msqbuf, msqbuf32, msg_lrpid);
1371 		CP(msqbuf, msqbuf32, msg_stime);
1372 		CP(msqbuf, msqbuf32, msg_rtime);
1373 		CP(msqbuf, msqbuf32, msg_ctime);
1374 		error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1375 	}
1376 	return (error);
1377 }
1378 #endif
1379 
1380 int
1381 freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap)
1382 {
1383 	struct msqid_ds msqbuf;
1384 	struct msqid_ds32 msqbuf32;
1385 	int error;
1386 
1387 	if (uap->cmd == IPC_SET) {
1388 		error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1389 		if (error)
1390 			return (error);
1391 		freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1392 		PTRIN_CP(msqbuf32, msqbuf, msg_first);
1393 		PTRIN_CP(msqbuf32, msqbuf, msg_last);
1394 		CP(msqbuf32, msqbuf, msg_cbytes);
1395 		CP(msqbuf32, msqbuf, msg_qnum);
1396 		CP(msqbuf32, msqbuf, msg_qbytes);
1397 		CP(msqbuf32, msqbuf, msg_lspid);
1398 		CP(msqbuf32, msqbuf, msg_lrpid);
1399 		CP(msqbuf32, msqbuf, msg_stime);
1400 		CP(msqbuf32, msqbuf, msg_rtime);
1401 		CP(msqbuf32, msqbuf, msg_ctime);
1402 	}
1403 	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1404 	if (error)
1405 		return (error);
1406 	if (uap->cmd == IPC_STAT) {
1407 		freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1408 		PTROUT_CP(msqbuf, msqbuf32, msg_first);
1409 		PTROUT_CP(msqbuf, msqbuf32, msg_last);
1410 		CP(msqbuf, msqbuf32, msg_cbytes);
1411 		CP(msqbuf, msqbuf32, msg_qnum);
1412 		CP(msqbuf, msqbuf32, msg_qbytes);
1413 		CP(msqbuf, msqbuf32, msg_lspid);
1414 		CP(msqbuf, msqbuf32, msg_lrpid);
1415 		CP(msqbuf, msqbuf32, msg_stime);
1416 		CP(msqbuf, msqbuf32, msg_rtime);
1417 		CP(msqbuf, msqbuf32, msg_ctime);
1418 		error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1419 	}
1420 	return (error);
1421 }
1422 
1423 int
1424 freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap)
1425 {
1426 	const void *msgp;
1427 	long mtype;
1428 	int32_t mtype32;
1429 	int error;
1430 
1431 	msgp = PTRIN(uap->msgp);
1432 	if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0)
1433 		return (error);
1434 	mtype = mtype32;
1435 	return (kern_msgsnd(td, uap->msqid,
1436 	    (const char *)msgp + sizeof(mtype32),
1437 	    uap->msgsz, uap->msgflg, mtype));
1438 }
1439 
1440 int
1441 freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap)
1442 {
1443 	void *msgp;
1444 	long mtype;
1445 	int32_t mtype32;
1446 	int error;
1447 
1448 	msgp = PTRIN(uap->msgp);
1449 	if ((error = kern_msgrcv(td, uap->msqid,
1450 	    (char *)msgp + sizeof(mtype32), uap->msgsz,
1451 	    uap->msgtyp, uap->msgflg, &mtype)) != 0)
1452 		return (error);
1453 	mtype32 = (int32_t)mtype;
1454 	return (copyout(&mtype32, msgp, sizeof(mtype32)));
1455 }
1456 #endif
1457 
1458 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1459     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1460 
1461 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1462 static sy_call_t *msgcalls[] = {
1463 	(sy_call_t *)freebsd7_msgctl, (sy_call_t *)msgget,
1464 	(sy_call_t *)msgsnd, (sy_call_t *)msgrcv
1465 };
1466 
1467 /*
1468  * Entry point for all MSG calls.
1469  */
1470 int
1471 msgsys(td, uap)
1472 	struct thread *td;
1473 	/* XXX actually varargs. */
1474 	struct msgsys_args /* {
1475 		int	which;
1476 		int	a2;
1477 		int	a3;
1478 		int	a4;
1479 		int	a5;
1480 		int	a6;
1481 	} */ *uap;
1482 {
1483 	int error;
1484 
1485 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1486 		return (ENOSYS);
1487 	if (uap->which < 0 ||
1488 	    uap->which >= sizeof(msgcalls)/sizeof(msgcalls[0]))
1489 		return (EINVAL);
1490 	error = (*msgcalls[uap->which])(td, &uap->a2);
1491 	return (error);
1492 }
1493 
1494 #ifndef CP
1495 #define CP(src, dst, fld)	do { (dst).fld = (src).fld; } while (0)
1496 #endif
1497 
1498 #ifndef _SYS_SYSPROTO_H_
1499 struct freebsd7_msgctl_args {
1500 	int	msqid;
1501 	int	cmd;
1502 	struct	msqid_ds_old *buf;
1503 };
1504 #endif
1505 int
1506 freebsd7_msgctl(td, uap)
1507 	struct thread *td;
1508 	struct freebsd7_msgctl_args *uap;
1509 {
1510 	struct msqid_ds_old msqold;
1511 	struct msqid_ds msqbuf;
1512 	int error;
1513 
1514 	DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
1515 	    uap->buf));
1516 	if (uap->cmd == IPC_SET) {
1517 		error = copyin(uap->buf, &msqold, sizeof(msqold));
1518 		if (error)
1519 			return (error);
1520 		ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
1521 		CP(msqold, msqbuf, msg_first);
1522 		CP(msqold, msqbuf, msg_last);
1523 		CP(msqold, msqbuf, msg_cbytes);
1524 		CP(msqold, msqbuf, msg_qnum);
1525 		CP(msqold, msqbuf, msg_qbytes);
1526 		CP(msqold, msqbuf, msg_lspid);
1527 		CP(msqold, msqbuf, msg_lrpid);
1528 		CP(msqold, msqbuf, msg_stime);
1529 		CP(msqold, msqbuf, msg_rtime);
1530 		CP(msqold, msqbuf, msg_ctime);
1531 	}
1532 	error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1533 	if (error)
1534 		return (error);
1535 	if (uap->cmd == IPC_STAT) {
1536 		bzero(&msqold, sizeof(msqold));
1537 		ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
1538 		CP(msqbuf, msqold, msg_first);
1539 		CP(msqbuf, msqold, msg_last);
1540 		CP(msqbuf, msqold, msg_cbytes);
1541 		CP(msqbuf, msqold, msg_qnum);
1542 		CP(msqbuf, msqold, msg_qbytes);
1543 		CP(msqbuf, msqold, msg_lspid);
1544 		CP(msqbuf, msqold, msg_lrpid);
1545 		CP(msqbuf, msqold, msg_stime);
1546 		CP(msqbuf, msqold, msg_rtime);
1547 		CP(msqbuf, msqold, msg_ctime);
1548 		error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
1549 	}
1550 	return (error);
1551 }
1552 
1553 #undef CP
1554 
1555 #endif	/* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1556 	   COMPAT_FREEBSD7 */
1557