FreeBSD/Linux Kernel Cross Reference
sys/kern/sysv_msg.c
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: releng/11.0/sys/kern/sysv_msg.c 301737 2016-06-09 15:34:33Z jamie $");
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/mount.h>
66 #include <sys/msg.h>
67 #include <sys/racct.h>
68 #include <sys/sx.h>
69 #include <sys/syscall.h>
70 #include <sys/syscallsubr.h>
71 #include <sys/sysent.h>
72 #include <sys/sysctl.h>
73 #include <sys/malloc.h>
74 #include <sys/jail.h>
75
76 #include <security/mac/mac_framework.h>
77
78 FEATURE(sysv_msg, "System V message queues support");
79
80 static MALLOC_DEFINE(M_MSG, "msg", "SVID compatible message queues");
81
82 static int msginit(void);
83 static int msgunload(void);
84 static int sysvmsg_modload(struct module *, int, void *);
85 static void msq_remove(struct msqid_kernel *);
86 static struct prison *msg_find_prison(struct ucred *);
87 static int msq_prison_cansee(struct prison *, struct msqid_kernel *);
88 static int msg_prison_check(void *, void *);
89 static int msg_prison_set(void *, void *);
90 static int msg_prison_get(void *, void *);
91 static int msg_prison_remove(void *, void *);
92 static void msg_prison_cleanup(struct prison *);
93
94
95 #ifdef MSG_DEBUG
96 #define DPRINTF(a) printf a
97 #else
98 #define DPRINTF(a) (void)0
99 #endif
100
101 static void msg_freehdr(struct msg *msghdr);
102
103 #ifndef MSGSSZ
104 #define MSGSSZ 8 /* Each segment must be 2^N long */
105 #endif
106 #ifndef MSGSEG
107 #define MSGSEG 2048 /* must be less than 32767 */
108 #endif
109 #define MSGMAX (MSGSSZ*MSGSEG)
110 #ifndef MSGMNB
111 #define MSGMNB 2048 /* max # of bytes in a queue */
112 #endif
113 #ifndef MSGMNI
114 #define MSGMNI 40
115 #endif
116 #ifndef MSGTQL
117 #define MSGTQL 40
118 #endif
119
120 /*
121 * Based on the configuration parameters described in an SVR2 (yes, two)
122 * config(1m) man page.
123 *
124 * Each message is broken up and stored in segments that are msgssz bytes
125 * long. For efficiency reasons, this should be a power of two. Also,
126 * it doesn't make sense if it is less than 8 or greater than about 256.
127 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
128 * two between 8 and 1024 inclusive (and panic's if it isn't).
129 */
130 struct msginfo msginfo = {
131 MSGMAX, /* max chars in a message */
132 MSGMNI, /* # of message queue identifiers */
133 MSGMNB, /* max chars in a queue */
134 MSGTQL, /* max messages in system */
135 MSGSSZ, /* size of a message segment */
136 /* (must be small power of 2 greater than 4) */
137 MSGSEG /* number of message segments */
138 };
139
140 /*
141 * macros to convert between msqid_ds's and msqid's.
142 * (specific to this implementation)
143 */
144 #define MSQID(ix,ds) ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
145 #define MSQID_IX(id) ((id) & 0xffff)
146 #define MSQID_SEQ(id) (((id) >> 16) & 0xffff)
147
148 /*
149 * The rest of this file is specific to this particular implementation.
150 */
151
152 struct msgmap {
153 short next; /* next segment in buffer */
154 /* -1 -> available */
155 /* 0..(MSGSEG-1) -> index of next segment */
156 };
157
158 #define MSG_LOCKED 01000 /* Is this msqid_ds locked? */
159
160 static int nfree_msgmaps; /* # of free map entries */
161 static short free_msgmaps; /* head of linked list of free map entries */
162 static struct msg *free_msghdrs;/* list of free msg headers */
163 static char *msgpool; /* MSGMAX byte long msg buffer pool */
164 static struct msgmap *msgmaps; /* MSGSEG msgmap structures */
165 static struct msg *msghdrs; /* MSGTQL msg headers */
166 static struct msqid_kernel *msqids; /* MSGMNI msqid_kernel struct's */
167 static struct mtx msq_mtx; /* global mutex for message queues. */
168 static unsigned msg_prison_slot;/* prison OSD slot */
169
170 static struct syscall_helper_data msg_syscalls[] = {
171 SYSCALL_INIT_HELPER(msgctl),
172 SYSCALL_INIT_HELPER(msgget),
173 SYSCALL_INIT_HELPER(msgsnd),
174 SYSCALL_INIT_HELPER(msgrcv),
175 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
176 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
177 SYSCALL_INIT_HELPER(msgsys),
178 SYSCALL_INIT_HELPER_COMPAT(freebsd7_msgctl),
179 #endif
180 SYSCALL_INIT_LAST
181 };
182
183 #ifdef COMPAT_FREEBSD32
184 #include <compat/freebsd32/freebsd32.h>
185 #include <compat/freebsd32/freebsd32_ipc.h>
186 #include <compat/freebsd32/freebsd32_proto.h>
187 #include <compat/freebsd32/freebsd32_signal.h>
188 #include <compat/freebsd32/freebsd32_syscall.h>
189 #include <compat/freebsd32/freebsd32_util.h>
190
191 static struct syscall_helper_data msg32_syscalls[] = {
192 SYSCALL32_INIT_HELPER(freebsd32_msgctl),
193 SYSCALL32_INIT_HELPER(freebsd32_msgsnd),
194 SYSCALL32_INIT_HELPER(freebsd32_msgrcv),
195 SYSCALL32_INIT_HELPER_COMPAT(msgget),
196 SYSCALL32_INIT_HELPER(freebsd32_msgsys),
197 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
198 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
199 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_msgctl),
200 #endif
201 SYSCALL_INIT_LAST
202 };
203 #endif
204
205 static int
206 msginit()
207 {
208 struct prison *pr;
209 void **rsv;
210 int i, error;
211 osd_method_t methods[PR_MAXMETHOD] = {
212 [PR_METHOD_CHECK] = msg_prison_check,
213 [PR_METHOD_SET] = msg_prison_set,
214 [PR_METHOD_GET] = msg_prison_get,
215 [PR_METHOD_REMOVE] = msg_prison_remove,
216 };
217
218 msginfo.msgmax = msginfo.msgseg * msginfo.msgssz;
219 msgpool = malloc(msginfo.msgmax, M_MSG, M_WAITOK);
220 msgmaps = malloc(sizeof(struct msgmap) * msginfo.msgseg, M_MSG, M_WAITOK);
221 msghdrs = malloc(sizeof(struct msg) * msginfo.msgtql, M_MSG, M_WAITOK);
222 msqids = malloc(sizeof(struct msqid_kernel) * msginfo.msgmni, M_MSG,
223 M_WAITOK);
224
225 /*
226 * msginfo.msgssz should be a power of two for efficiency reasons.
227 * It is also pretty silly if msginfo.msgssz is less than 8
228 * or greater than about 256 so ...
229 */
230
231 i = 8;
232 while (i < 1024 && i != msginfo.msgssz)
233 i <<= 1;
234 if (i != msginfo.msgssz) {
235 DPRINTF(("msginfo.msgssz=%d (0x%x)\n", msginfo.msgssz,
236 msginfo.msgssz));
237 panic("msginfo.msgssz not a small power of 2");
238 }
239
240 if (msginfo.msgseg > 32767) {
241 DPRINTF(("msginfo.msgseg=%d\n", msginfo.msgseg));
242 panic("msginfo.msgseg > 32767");
243 }
244
245 for (i = 0; i < msginfo.msgseg; i++) {
246 if (i > 0)
247 msgmaps[i-1].next = i;
248 msgmaps[i].next = -1; /* implies entry is available */
249 }
250 free_msgmaps = 0;
251 nfree_msgmaps = msginfo.msgseg;
252
253 for (i = 0; i < msginfo.msgtql; i++) {
254 msghdrs[i].msg_type = 0;
255 if (i > 0)
256 msghdrs[i-1].msg_next = &msghdrs[i];
257 msghdrs[i].msg_next = NULL;
258 #ifdef MAC
259 mac_sysvmsg_init(&msghdrs[i]);
260 #endif
261 }
262 free_msghdrs = &msghdrs[0];
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 /* Set current prisons according to their allow.sysvipc. */
275 msg_prison_slot = osd_jail_register(NULL, methods);
276 rsv = osd_reserve(msg_prison_slot);
277 prison_lock(&prison0);
278 (void)osd_jail_set_reserved(&prison0, msg_prison_slot, rsv, &prison0);
279 prison_unlock(&prison0);
280 rsv = NULL;
281 sx_slock(&allprison_lock);
282 TAILQ_FOREACH(pr, &allprison, pr_list) {
283 if (rsv == NULL)
284 rsv = osd_reserve(msg_prison_slot);
285 prison_lock(pr);
286 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
287 (void)osd_jail_set_reserved(pr, msg_prison_slot, rsv,
288 &prison0);
289 rsv = NULL;
290 }
291 prison_unlock(pr);
292 }
293 if (rsv != NULL)
294 osd_free_reserved(rsv);
295 sx_sunlock(&allprison_lock);
296
297 error = syscall_helper_register(msg_syscalls, SY_THR_STATIC_KLD);
298 if (error != 0)
299 return (error);
300 #ifdef COMPAT_FREEBSD32
301 error = syscall32_helper_register(msg32_syscalls, SY_THR_STATIC_KLD);
302 if (error != 0)
303 return (error);
304 #endif
305 return (0);
306 }
307
308 static int
309 msgunload()
310 {
311 struct msqid_kernel *msqkptr;
312 int msqid;
313 #ifdef MAC
314 int i;
315 #endif
316
317 syscall_helper_unregister(msg_syscalls);
318 #ifdef COMPAT_FREEBSD32
319 syscall32_helper_unregister(msg32_syscalls);
320 #endif
321
322 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
323 msqkptr = &msqids[msqid];
324 if (msqkptr->u.msg_qbytes != 0 ||
325 (msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
326 break;
327 }
328 if (msqid != msginfo.msgmni)
329 return (EBUSY);
330
331 if (msg_prison_slot != 0)
332 osd_jail_deregister(msg_prison_slot);
333 #ifdef MAC
334 for (i = 0; i < msginfo.msgtql; i++)
335 mac_sysvmsg_destroy(&msghdrs[i]);
336 for (msqid = 0; msqid < msginfo.msgmni; msqid++)
337 mac_sysvmsq_destroy(&msqids[msqid]);
338 #endif
339 free(msgpool, M_MSG);
340 free(msgmaps, M_MSG);
341 free(msghdrs, M_MSG);
342 free(msqids, M_MSG);
343 mtx_destroy(&msq_mtx);
344 return (0);
345 }
346
347
348 static int
349 sysvmsg_modload(struct module *module, int cmd, void *arg)
350 {
351 int error = 0;
352
353 switch (cmd) {
354 case MOD_LOAD:
355 error = msginit();
356 if (error != 0)
357 msgunload();
358 break;
359 case MOD_UNLOAD:
360 error = msgunload();
361 break;
362 case MOD_SHUTDOWN:
363 break;
364 default:
365 error = EINVAL;
366 break;
367 }
368 return (error);
369 }
370
371 static moduledata_t sysvmsg_mod = {
372 "sysvmsg",
373 &sysvmsg_modload,
374 NULL
375 };
376
377 DECLARE_MODULE(sysvmsg, sysvmsg_mod, SI_SUB_SYSV_MSG, SI_ORDER_FIRST);
378 MODULE_VERSION(sysvmsg, 1);
379
380 static void
381 msg_freehdr(msghdr)
382 struct msg *msghdr;
383 {
384 while (msghdr->msg_ts > 0) {
385 short next;
386 if (msghdr->msg_spot < 0 || msghdr->msg_spot >= msginfo.msgseg)
387 panic("msghdr->msg_spot out of range");
388 next = msgmaps[msghdr->msg_spot].next;
389 msgmaps[msghdr->msg_spot].next = free_msgmaps;
390 free_msgmaps = msghdr->msg_spot;
391 nfree_msgmaps++;
392 msghdr->msg_spot = next;
393 if (msghdr->msg_ts >= msginfo.msgssz)
394 msghdr->msg_ts -= msginfo.msgssz;
395 else
396 msghdr->msg_ts = 0;
397 }
398 if (msghdr->msg_spot != -1)
399 panic("msghdr->msg_spot != -1");
400 msghdr->msg_next = free_msghdrs;
401 free_msghdrs = msghdr;
402 #ifdef MAC
403 mac_sysvmsg_cleanup(msghdr);
404 #endif
405 }
406
407 static void
408 msq_remove(struct msqid_kernel *msqkptr)
409 {
410 struct msg *msghdr;
411
412 racct_sub_cred(msqkptr->cred, RACCT_NMSGQ, 1);
413 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, msqkptr->u.msg_qnum);
414 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msqkptr->u.msg_cbytes);
415 crfree(msqkptr->cred);
416 msqkptr->cred = NULL;
417
418 /* Free the message headers */
419 msghdr = msqkptr->u.msg_first;
420 while (msghdr != NULL) {
421 struct msg *msghdr_tmp;
422
423 /* Free the segments of each message */
424 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
425 msqkptr->u.msg_qnum--;
426 msghdr_tmp = msghdr;
427 msghdr = msghdr->msg_next;
428 msg_freehdr(msghdr_tmp);
429 }
430
431 if (msqkptr->u.msg_cbytes != 0)
432 panic("msg_cbytes is screwed up");
433 if (msqkptr->u.msg_qnum != 0)
434 panic("msg_qnum is screwed up");
435
436 msqkptr->u.msg_qbytes = 0; /* Mark it as free */
437
438 #ifdef MAC
439 mac_sysvmsq_cleanup(msqkptr);
440 #endif
441
442 wakeup(msqkptr);
443 }
444
445 static struct prison *
446 msg_find_prison(struct ucred *cred)
447 {
448 struct prison *pr, *rpr;
449
450 pr = cred->cr_prison;
451 prison_lock(pr);
452 rpr = osd_jail_get(pr, msg_prison_slot);
453 prison_unlock(pr);
454 return rpr;
455 }
456
457 static int
458 msq_prison_cansee(struct prison *rpr, struct msqid_kernel *msqkptr)
459 {
460
461 if (msqkptr->cred == NULL ||
462 !(rpr == msqkptr->cred->cr_prison ||
463 prison_ischild(rpr, msqkptr->cred->cr_prison)))
464 return (EINVAL);
465 return (0);
466 }
467
468 #ifndef _SYS_SYSPROTO_H_
469 struct msgctl_args {
470 int msqid;
471 int cmd;
472 struct msqid_ds *buf;
473 };
474 #endif
475 int
476 sys_msgctl(td, uap)
477 struct thread *td;
478 register struct msgctl_args *uap;
479 {
480 int msqid = uap->msqid;
481 int cmd = uap->cmd;
482 struct msqid_ds msqbuf;
483 int error;
484
485 DPRINTF(("call to msgctl(%d, %d, %p)\n", msqid, cmd, uap->buf));
486 if (cmd == IPC_SET &&
487 (error = copyin(uap->buf, &msqbuf, sizeof(msqbuf))) != 0)
488 return (error);
489 error = kern_msgctl(td, msqid, cmd, &msqbuf);
490 if (cmd == IPC_STAT && error == 0)
491 error = copyout(&msqbuf, uap->buf, sizeof(struct msqid_ds));
492 return (error);
493 }
494
495 int
496 kern_msgctl(td, msqid, cmd, msqbuf)
497 struct thread *td;
498 int msqid;
499 int cmd;
500 struct msqid_ds *msqbuf;
501 {
502 int rval, error, msqix;
503 register struct msqid_kernel *msqkptr;
504 struct prison *rpr;
505
506 rpr = msg_find_prison(td->td_ucred);
507 if (rpr == NULL)
508 return (ENOSYS);
509
510 msqix = IPCID_TO_IX(msqid);
511
512 if (msqix < 0 || msqix >= msginfo.msgmni) {
513 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
514 msginfo.msgmni));
515 return (EINVAL);
516 }
517
518 msqkptr = &msqids[msqix];
519
520 mtx_lock(&msq_mtx);
521 if (msqkptr->u.msg_qbytes == 0) {
522 DPRINTF(("no such msqid\n"));
523 error = EINVAL;
524 goto done2;
525 }
526 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
527 DPRINTF(("wrong sequence number\n"));
528 error = EINVAL;
529 goto done2;
530 }
531
532 error = msq_prison_cansee(rpr, msqkptr);
533 if (error != 0) {
534 DPRINTF(("requester can't see prison\n"));
535 goto done2;
536 }
537
538 #ifdef MAC
539 error = mac_sysvmsq_check_msqctl(td->td_ucred, msqkptr, cmd);
540 if (error != 0)
541 goto done2;
542 #endif
543
544 error = 0;
545 rval = 0;
546
547 switch (cmd) {
548
549 case IPC_RMID:
550 {
551 #ifdef MAC
552 struct msg *msghdr;
553 #endif
554 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
555 goto done2;
556
557 #ifdef MAC
558 /*
559 * Check that the thread has MAC access permissions to
560 * individual msghdrs. Note: We need to do this in a
561 * separate loop because the actual loop alters the
562 * msq/msghdr info as it progresses, and there is no going
563 * back if half the way through we discover that the
564 * thread cannot free a certain msghdr. The msq will get
565 * into an inconsistent state.
566 */
567 for (msghdr = msqkptr->u.msg_first; msghdr != NULL;
568 msghdr = msghdr->msg_next) {
569 error = mac_sysvmsq_check_msgrmid(td->td_ucred, msghdr);
570 if (error != 0)
571 goto done2;
572 }
573 #endif
574
575 msq_remove(msqkptr);
576 }
577
578 break;
579
580 case IPC_SET:
581 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_M)))
582 goto done2;
583 if (msqbuf->msg_qbytes > msqkptr->u.msg_qbytes) {
584 error = priv_check(td, PRIV_IPC_MSGSIZE);
585 if (error)
586 goto done2;
587 }
588 if (msqbuf->msg_qbytes > msginfo.msgmnb) {
589 DPRINTF(("can't increase msg_qbytes beyond %d"
590 "(truncating)\n", msginfo.msgmnb));
591 msqbuf->msg_qbytes = msginfo.msgmnb; /* silently restrict qbytes to system limit */
592 }
593 if (msqbuf->msg_qbytes == 0) {
594 DPRINTF(("can't reduce msg_qbytes to 0\n"));
595 error = EINVAL; /* non-standard errno! */
596 goto done2;
597 }
598 msqkptr->u.msg_perm.uid = msqbuf->msg_perm.uid; /* change the owner */
599 msqkptr->u.msg_perm.gid = msqbuf->msg_perm.gid; /* change the owner */
600 msqkptr->u.msg_perm.mode = (msqkptr->u.msg_perm.mode & ~0777) |
601 (msqbuf->msg_perm.mode & 0777);
602 msqkptr->u.msg_qbytes = msqbuf->msg_qbytes;
603 msqkptr->u.msg_ctime = time_second;
604 break;
605
606 case IPC_STAT:
607 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
608 DPRINTF(("requester doesn't have read access\n"));
609 goto done2;
610 }
611 *msqbuf = msqkptr->u;
612 if (td->td_ucred->cr_prison != msqkptr->cred->cr_prison)
613 msqbuf->msg_perm.key = IPC_PRIVATE;
614 break;
615
616 default:
617 DPRINTF(("invalid command %d\n", cmd));
618 error = EINVAL;
619 goto done2;
620 }
621
622 if (error == 0)
623 td->td_retval[0] = rval;
624 done2:
625 mtx_unlock(&msq_mtx);
626 return (error);
627 }
628
629 #ifndef _SYS_SYSPROTO_H_
630 struct msgget_args {
631 key_t key;
632 int msgflg;
633 };
634 #endif
635
636 int
637 sys_msgget(td, uap)
638 struct thread *td;
639 register struct msgget_args *uap;
640 {
641 int msqid, error = 0;
642 int key = uap->key;
643 int msgflg = uap->msgflg;
644 struct ucred *cred = td->td_ucred;
645 register struct msqid_kernel *msqkptr = NULL;
646
647 DPRINTF(("msgget(0x%x, 0%o)\n", key, msgflg));
648
649 if (msg_find_prison(cred) == NULL)
650 return (ENOSYS);
651
652 mtx_lock(&msq_mtx);
653 if (key != IPC_PRIVATE) {
654 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
655 msqkptr = &msqids[msqid];
656 if (msqkptr->u.msg_qbytes != 0 &&
657 msqkptr->cred != NULL &&
658 msqkptr->cred->cr_prison == cred->cr_prison &&
659 msqkptr->u.msg_perm.key == key)
660 break;
661 }
662 if (msqid < msginfo.msgmni) {
663 DPRINTF(("found public key\n"));
664 if ((msgflg & IPC_CREAT) && (msgflg & IPC_EXCL)) {
665 DPRINTF(("not exclusive\n"));
666 error = EEXIST;
667 goto done2;
668 }
669 if ((error = ipcperm(td, &msqkptr->u.msg_perm,
670 msgflg & 0700))) {
671 DPRINTF(("requester doesn't have 0%o access\n",
672 msgflg & 0700));
673 goto done2;
674 }
675 #ifdef MAC
676 error = mac_sysvmsq_check_msqget(cred, msqkptr);
677 if (error != 0)
678 goto done2;
679 #endif
680 goto found;
681 }
682 }
683
684 DPRINTF(("need to allocate the msqid_ds\n"));
685 if (key == IPC_PRIVATE || (msgflg & IPC_CREAT)) {
686 for (msqid = 0; msqid < msginfo.msgmni; msqid++) {
687 /*
688 * Look for an unallocated and unlocked msqid_ds.
689 * msqid_ds's can be locked by msgsnd or msgrcv while
690 * they are copying the message in/out. We can't
691 * re-use the entry until they release it.
692 */
693 msqkptr = &msqids[msqid];
694 if (msqkptr->u.msg_qbytes == 0 &&
695 (msqkptr->u.msg_perm.mode & MSG_LOCKED) == 0)
696 break;
697 }
698 if (msqid == msginfo.msgmni) {
699 DPRINTF(("no more msqid_ds's available\n"));
700 error = ENOSPC;
701 goto done2;
702 }
703 #ifdef RACCT
704 if (racct_enable) {
705 PROC_LOCK(td->td_proc);
706 error = racct_add(td->td_proc, RACCT_NMSGQ, 1);
707 PROC_UNLOCK(td->td_proc);
708 if (error != 0) {
709 error = ENOSPC;
710 goto done2;
711 }
712 }
713 #endif
714 DPRINTF(("msqid %d is available\n", msqid));
715 msqkptr->u.msg_perm.key = key;
716 msqkptr->u.msg_perm.cuid = cred->cr_uid;
717 msqkptr->u.msg_perm.uid = cred->cr_uid;
718 msqkptr->u.msg_perm.cgid = cred->cr_gid;
719 msqkptr->u.msg_perm.gid = cred->cr_gid;
720 msqkptr->u.msg_perm.mode = (msgflg & 0777);
721 msqkptr->cred = crhold(cred);
722 /* Make sure that the returned msqid is unique */
723 msqkptr->u.msg_perm.seq = (msqkptr->u.msg_perm.seq + 1) & 0x7fff;
724 msqkptr->u.msg_first = NULL;
725 msqkptr->u.msg_last = NULL;
726 msqkptr->u.msg_cbytes = 0;
727 msqkptr->u.msg_qnum = 0;
728 msqkptr->u.msg_qbytes = msginfo.msgmnb;
729 msqkptr->u.msg_lspid = 0;
730 msqkptr->u.msg_lrpid = 0;
731 msqkptr->u.msg_stime = 0;
732 msqkptr->u.msg_rtime = 0;
733 msqkptr->u.msg_ctime = time_second;
734 #ifdef MAC
735 mac_sysvmsq_create(cred, msqkptr);
736 #endif
737 } else {
738 DPRINTF(("didn't find it and wasn't asked to create it\n"));
739 error = ENOENT;
740 goto done2;
741 }
742
743 found:
744 /* Construct the unique msqid */
745 td->td_retval[0] = IXSEQ_TO_IPCID(msqid, msqkptr->u.msg_perm);
746 done2:
747 mtx_unlock(&msq_mtx);
748 return (error);
749 }
750
751 #ifndef _SYS_SYSPROTO_H_
752 struct msgsnd_args {
753 int msqid;
754 const void *msgp;
755 size_t msgsz;
756 int msgflg;
757 };
758 #endif
759 int
760 kern_msgsnd(td, msqid, msgp, msgsz, msgflg, mtype)
761 struct thread *td;
762 int msqid;
763 const void *msgp; /* XXX msgp is actually mtext. */
764 size_t msgsz;
765 int msgflg;
766 long mtype;
767 {
768 int msqix, segs_needed, error = 0;
769 register struct msqid_kernel *msqkptr;
770 register struct msg *msghdr;
771 struct prison *rpr;
772 short next;
773 #ifdef RACCT
774 size_t saved_msgsz;
775 #endif
776
777 rpr = msg_find_prison(td->td_ucred);
778 if (rpr == NULL)
779 return (ENOSYS);
780
781 mtx_lock(&msq_mtx);
782 msqix = IPCID_TO_IX(msqid);
783
784 if (msqix < 0 || msqix >= msginfo.msgmni) {
785 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
786 msginfo.msgmni));
787 error = EINVAL;
788 goto done2;
789 }
790
791 msqkptr = &msqids[msqix];
792 if (msqkptr->u.msg_qbytes == 0) {
793 DPRINTF(("no such message queue id\n"));
794 error = EINVAL;
795 goto done2;
796 }
797 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
798 DPRINTF(("wrong sequence number\n"));
799 error = EINVAL;
800 goto done2;
801 }
802
803 if ((error = msq_prison_cansee(rpr, msqkptr))) {
804 DPRINTF(("requester can't see prison\n"));
805 goto done2;
806 }
807
808 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_W))) {
809 DPRINTF(("requester doesn't have write access\n"));
810 goto done2;
811 }
812
813 #ifdef MAC
814 error = mac_sysvmsq_check_msqsnd(td->td_ucred, msqkptr);
815 if (error != 0)
816 goto done2;
817 #endif
818
819 #ifdef RACCT
820 if (racct_enable) {
821 PROC_LOCK(td->td_proc);
822 if (racct_add(td->td_proc, RACCT_MSGQQUEUED, 1)) {
823 PROC_UNLOCK(td->td_proc);
824 error = EAGAIN;
825 goto done2;
826 }
827 saved_msgsz = msgsz;
828 if (racct_add(td->td_proc, RACCT_MSGQSIZE, msgsz)) {
829 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
830 PROC_UNLOCK(td->td_proc);
831 error = EAGAIN;
832 goto done2;
833 }
834 PROC_UNLOCK(td->td_proc);
835 }
836 #endif
837
838 segs_needed = howmany(msgsz, msginfo.msgssz);
839 DPRINTF(("msgsz=%zu, msgssz=%d, segs_needed=%d\n", msgsz,
840 msginfo.msgssz, segs_needed));
841 for (;;) {
842 int need_more_resources = 0;
843
844 /*
845 * check msgsz
846 * (inside this loop in case msg_qbytes changes while we sleep)
847 */
848
849 if (msgsz > msqkptr->u.msg_qbytes) {
850 DPRINTF(("msgsz > msqkptr->u.msg_qbytes\n"));
851 error = EINVAL;
852 goto done3;
853 }
854
855 if (msqkptr->u.msg_perm.mode & MSG_LOCKED) {
856 DPRINTF(("msqid is locked\n"));
857 need_more_resources = 1;
858 }
859 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes) {
860 DPRINTF(("msgsz + msg_cbytes > msg_qbytes\n"));
861 need_more_resources = 1;
862 }
863 if (segs_needed > nfree_msgmaps) {
864 DPRINTF(("segs_needed > nfree_msgmaps\n"));
865 need_more_resources = 1;
866 }
867 if (free_msghdrs == NULL) {
868 DPRINTF(("no more msghdrs\n"));
869 need_more_resources = 1;
870 }
871
872 if (need_more_resources) {
873 int we_own_it;
874
875 if ((msgflg & IPC_NOWAIT) != 0) {
876 DPRINTF(("need more resources but caller "
877 "doesn't want to wait\n"));
878 error = EAGAIN;
879 goto done3;
880 }
881
882 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0) {
883 DPRINTF(("we don't own the msqid_ds\n"));
884 we_own_it = 0;
885 } else {
886 /* Force later arrivals to wait for our
887 request */
888 DPRINTF(("we own the msqid_ds\n"));
889 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
890 we_own_it = 1;
891 }
892 DPRINTF(("msgsnd: goodnight\n"));
893 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
894 "msgsnd", hz);
895 DPRINTF(("msgsnd: good morning, error=%d\n", error));
896 if (we_own_it)
897 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
898 if (error == EWOULDBLOCK) {
899 DPRINTF(("msgsnd: timed out\n"));
900 continue;
901 }
902 if (error != 0) {
903 DPRINTF(("msgsnd: interrupted system call\n"));
904 error = EINTR;
905 goto done3;
906 }
907
908 /*
909 * Make sure that the msq queue still exists
910 */
911
912 if (msqkptr->u.msg_qbytes == 0) {
913 DPRINTF(("msqid deleted\n"));
914 error = EIDRM;
915 goto done3;
916 }
917
918 } else {
919 DPRINTF(("got all the resources that we need\n"));
920 break;
921 }
922 }
923
924 /*
925 * We have the resources that we need.
926 * Make sure!
927 */
928
929 if (msqkptr->u.msg_perm.mode & MSG_LOCKED)
930 panic("msg_perm.mode & MSG_LOCKED");
931 if (segs_needed > nfree_msgmaps)
932 panic("segs_needed > nfree_msgmaps");
933 if (msgsz + msqkptr->u.msg_cbytes > msqkptr->u.msg_qbytes)
934 panic("msgsz + msg_cbytes > msg_qbytes");
935 if (free_msghdrs == NULL)
936 panic("no more msghdrs");
937
938 /*
939 * Re-lock the msqid_ds in case we page-fault when copying in the
940 * message
941 */
942
943 if ((msqkptr->u.msg_perm.mode & MSG_LOCKED) != 0)
944 panic("msqid_ds is already locked");
945 msqkptr->u.msg_perm.mode |= MSG_LOCKED;
946
947 /*
948 * Allocate a message header
949 */
950
951 msghdr = free_msghdrs;
952 free_msghdrs = msghdr->msg_next;
953 msghdr->msg_spot = -1;
954 msghdr->msg_ts = msgsz;
955 msghdr->msg_type = mtype;
956 #ifdef MAC
957 /*
958 * XXXMAC: Should the mac_sysvmsq_check_msgmsq check follow here
959 * immediately? Or, should it be checked just before the msg is
960 * enqueued in the msgq (as it is done now)?
961 */
962 mac_sysvmsg_create(td->td_ucred, msqkptr, msghdr);
963 #endif
964
965 /*
966 * Allocate space for the message
967 */
968
969 while (segs_needed > 0) {
970 if (nfree_msgmaps <= 0)
971 panic("not enough msgmaps");
972 if (free_msgmaps == -1)
973 panic("nil free_msgmaps");
974 next = free_msgmaps;
975 if (next <= -1)
976 panic("next too low #1");
977 if (next >= msginfo.msgseg)
978 panic("next out of range #1");
979 DPRINTF(("allocating segment %d to message\n", next));
980 free_msgmaps = msgmaps[next].next;
981 nfree_msgmaps--;
982 msgmaps[next].next = msghdr->msg_spot;
983 msghdr->msg_spot = next;
984 segs_needed--;
985 }
986
987 /*
988 * Validate the message type
989 */
990
991 if (msghdr->msg_type < 1) {
992 msg_freehdr(msghdr);
993 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
994 wakeup(msqkptr);
995 DPRINTF(("mtype (%ld) < 1\n", msghdr->msg_type));
996 error = EINVAL;
997 goto done3;
998 }
999
1000 /*
1001 * Copy in the message body
1002 */
1003
1004 next = msghdr->msg_spot;
1005 while (msgsz > 0) {
1006 size_t tlen;
1007 if (msgsz > msginfo.msgssz)
1008 tlen = msginfo.msgssz;
1009 else
1010 tlen = msgsz;
1011 if (next <= -1)
1012 panic("next too low #2");
1013 if (next >= msginfo.msgseg)
1014 panic("next out of range #2");
1015 mtx_unlock(&msq_mtx);
1016 if ((error = copyin(msgp, &msgpool[next * msginfo.msgssz],
1017 tlen)) != 0) {
1018 mtx_lock(&msq_mtx);
1019 DPRINTF(("error %d copying in message segment\n",
1020 error));
1021 msg_freehdr(msghdr);
1022 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
1023 wakeup(msqkptr);
1024 goto done3;
1025 }
1026 mtx_lock(&msq_mtx);
1027 msgsz -= tlen;
1028 msgp = (const char *)msgp + tlen;
1029 next = msgmaps[next].next;
1030 }
1031 if (next != -1)
1032 panic("didn't use all the msg segments");
1033
1034 /*
1035 * We've got the message. Unlock the msqid_ds.
1036 */
1037
1038 msqkptr->u.msg_perm.mode &= ~MSG_LOCKED;
1039
1040 /*
1041 * Make sure that the msqid_ds is still allocated.
1042 */
1043
1044 if (msqkptr->u.msg_qbytes == 0) {
1045 msg_freehdr(msghdr);
1046 wakeup(msqkptr);
1047 error = EIDRM;
1048 goto done3;
1049 }
1050
1051 #ifdef MAC
1052 /*
1053 * Note: Since the task/thread allocates the msghdr and usually
1054 * primes it with its own MAC label, for a majority of policies, it
1055 * won't be necessary to check whether the msghdr has access
1056 * permissions to the msgq. The mac_sysvmsq_check_msqsnd check would
1057 * suffice in that case. However, this hook may be required where
1058 * individual policies derive a non-identical label for the msghdr
1059 * from the current thread label and may want to check the msghdr
1060 * enqueue permissions, along with read/write permissions to the
1061 * msgq.
1062 */
1063 error = mac_sysvmsq_check_msgmsq(td->td_ucred, msghdr, msqkptr);
1064 if (error != 0) {
1065 msg_freehdr(msghdr);
1066 wakeup(msqkptr);
1067 goto done3;
1068 }
1069 #endif
1070
1071 /*
1072 * Put the message into the queue
1073 */
1074 if (msqkptr->u.msg_first == NULL) {
1075 msqkptr->u.msg_first = msghdr;
1076 msqkptr->u.msg_last = msghdr;
1077 } else {
1078 msqkptr->u.msg_last->msg_next = msghdr;
1079 msqkptr->u.msg_last = msghdr;
1080 }
1081 msqkptr->u.msg_last->msg_next = NULL;
1082
1083 msqkptr->u.msg_cbytes += msghdr->msg_ts;
1084 msqkptr->u.msg_qnum++;
1085 msqkptr->u.msg_lspid = td->td_proc->p_pid;
1086 msqkptr->u.msg_stime = time_second;
1087
1088 wakeup(msqkptr);
1089 td->td_retval[0] = 0;
1090 done3:
1091 #ifdef RACCT
1092 if (racct_enable && error != 0) {
1093 PROC_LOCK(td->td_proc);
1094 racct_sub(td->td_proc, RACCT_MSGQQUEUED, 1);
1095 racct_sub(td->td_proc, RACCT_MSGQSIZE, saved_msgsz);
1096 PROC_UNLOCK(td->td_proc);
1097 }
1098 #endif
1099 done2:
1100 mtx_unlock(&msq_mtx);
1101 return (error);
1102 }
1103
1104 int
1105 sys_msgsnd(td, uap)
1106 struct thread *td;
1107 register struct msgsnd_args *uap;
1108 {
1109 int error;
1110 long mtype;
1111
1112 DPRINTF(("call to msgsnd(%d, %p, %zu, %d)\n", uap->msqid, uap->msgp,
1113 uap->msgsz, uap->msgflg));
1114
1115 if ((error = copyin(uap->msgp, &mtype, sizeof(mtype))) != 0) {
1116 DPRINTF(("error %d copying the message type\n", error));
1117 return (error);
1118 }
1119 return (kern_msgsnd(td, uap->msqid,
1120 (const char *)uap->msgp + sizeof(mtype),
1121 uap->msgsz, uap->msgflg, mtype));
1122 }
1123
1124 #ifndef _SYS_SYSPROTO_H_
1125 struct msgrcv_args {
1126 int msqid;
1127 void *msgp;
1128 size_t msgsz;
1129 long msgtyp;
1130 int msgflg;
1131 };
1132 #endif
1133 int
1134 kern_msgrcv(td, msqid, msgp, msgsz, msgtyp, msgflg, mtype)
1135 struct thread *td;
1136 int msqid;
1137 void *msgp; /* XXX msgp is actually mtext. */
1138 size_t msgsz;
1139 long msgtyp;
1140 int msgflg;
1141 long *mtype;
1142 {
1143 size_t len;
1144 register struct msqid_kernel *msqkptr;
1145 register struct msg *msghdr;
1146 struct prison *rpr;
1147 int msqix, error = 0;
1148 short next;
1149
1150 rpr = msg_find_prison(td->td_ucred);
1151 if (rpr == NULL)
1152 return (ENOSYS);
1153
1154 msqix = IPCID_TO_IX(msqid);
1155
1156 if (msqix < 0 || msqix >= msginfo.msgmni) {
1157 DPRINTF(("msqid (%d) out of range (0<=msqid<%d)\n", msqix,
1158 msginfo.msgmni));
1159 return (EINVAL);
1160 }
1161
1162 msqkptr = &msqids[msqix];
1163 mtx_lock(&msq_mtx);
1164 if (msqkptr->u.msg_qbytes == 0) {
1165 DPRINTF(("no such message queue id\n"));
1166 error = EINVAL;
1167 goto done2;
1168 }
1169 if (msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1170 DPRINTF(("wrong sequence number\n"));
1171 error = EINVAL;
1172 goto done2;
1173 }
1174
1175 if ((error = msq_prison_cansee(rpr, msqkptr))) {
1176 DPRINTF(("requester can't see prison\n"));
1177 goto done2;
1178 }
1179
1180 if ((error = ipcperm(td, &msqkptr->u.msg_perm, IPC_R))) {
1181 DPRINTF(("requester doesn't have read access\n"));
1182 goto done2;
1183 }
1184
1185 #ifdef MAC
1186 error = mac_sysvmsq_check_msqrcv(td->td_ucred, msqkptr);
1187 if (error != 0)
1188 goto done2;
1189 #endif
1190
1191 msghdr = NULL;
1192 while (msghdr == NULL) {
1193 if (msgtyp == 0) {
1194 msghdr = msqkptr->u.msg_first;
1195 if (msghdr != NULL) {
1196 if (msgsz < msghdr->msg_ts &&
1197 (msgflg & MSG_NOERROR) == 0) {
1198 DPRINTF(("first message on the queue "
1199 "is too big (want %zu, got %d)\n",
1200 msgsz, msghdr->msg_ts));
1201 error = E2BIG;
1202 goto done2;
1203 }
1204 #ifdef MAC
1205 error = mac_sysvmsq_check_msgrcv(td->td_ucred,
1206 msghdr);
1207 if (error != 0)
1208 goto done2;
1209 #endif
1210 if (msqkptr->u.msg_first == msqkptr->u.msg_last) {
1211 msqkptr->u.msg_first = NULL;
1212 msqkptr->u.msg_last = NULL;
1213 } else {
1214 msqkptr->u.msg_first = msghdr->msg_next;
1215 if (msqkptr->u.msg_first == NULL)
1216 panic("msg_first/last screwed up #1");
1217 }
1218 }
1219 } else {
1220 struct msg *previous;
1221 struct msg **prev;
1222
1223 previous = NULL;
1224 prev = &(msqkptr->u.msg_first);
1225 while ((msghdr = *prev) != NULL) {
1226 /*
1227 * Is this message's type an exact match or is
1228 * this message's type less than or equal to
1229 * the absolute value of a negative msgtyp?
1230 * Note that the second half of this test can
1231 * NEVER be true if msgtyp is positive since
1232 * msg_type is always positive!
1233 */
1234
1235 if (msgtyp == msghdr->msg_type ||
1236 msghdr->msg_type <= -msgtyp) {
1237 DPRINTF(("found message type %ld, "
1238 "requested %ld\n",
1239 msghdr->msg_type, msgtyp));
1240 if (msgsz < msghdr->msg_ts &&
1241 (msgflg & MSG_NOERROR) == 0) {
1242 DPRINTF(("requested message "
1243 "on the queue is too big "
1244 "(want %zu, got %hu)\n",
1245 msgsz, msghdr->msg_ts));
1246 error = E2BIG;
1247 goto done2;
1248 }
1249 #ifdef MAC
1250 error = mac_sysvmsq_check_msgrcv(
1251 td->td_ucred, msghdr);
1252 if (error != 0)
1253 goto done2;
1254 #endif
1255 *prev = msghdr->msg_next;
1256 if (msghdr == msqkptr->u.msg_last) {
1257 if (previous == NULL) {
1258 if (prev !=
1259 &msqkptr->u.msg_first)
1260 panic("msg_first/last screwed up #2");
1261 msqkptr->u.msg_first =
1262 NULL;
1263 msqkptr->u.msg_last =
1264 NULL;
1265 } else {
1266 if (prev ==
1267 &msqkptr->u.msg_first)
1268 panic("msg_first/last screwed up #3");
1269 msqkptr->u.msg_last =
1270 previous;
1271 }
1272 }
1273 break;
1274 }
1275 previous = msghdr;
1276 prev = &(msghdr->msg_next);
1277 }
1278 }
1279
1280 /*
1281 * We've either extracted the msghdr for the appropriate
1282 * message or there isn't one.
1283 * If there is one then bail out of this loop.
1284 */
1285
1286 if (msghdr != NULL)
1287 break;
1288
1289 /*
1290 * Hmph! No message found. Does the user want to wait?
1291 */
1292
1293 if ((msgflg & IPC_NOWAIT) != 0) {
1294 DPRINTF(("no appropriate message found (msgtyp=%ld)\n",
1295 msgtyp));
1296 /* The SVID says to return ENOMSG. */
1297 error = ENOMSG;
1298 goto done2;
1299 }
1300
1301 /*
1302 * Wait for something to happen
1303 */
1304
1305 DPRINTF(("msgrcv: goodnight\n"));
1306 error = msleep(msqkptr, &msq_mtx, (PZERO - 4) | PCATCH,
1307 "msgrcv", 0);
1308 DPRINTF(("msgrcv: good morning (error=%d)\n", error));
1309
1310 if (error != 0) {
1311 DPRINTF(("msgrcv: interrupted system call\n"));
1312 error = EINTR;
1313 goto done2;
1314 }
1315
1316 /*
1317 * Make sure that the msq queue still exists
1318 */
1319
1320 if (msqkptr->u.msg_qbytes == 0 ||
1321 msqkptr->u.msg_perm.seq != IPCID_TO_SEQ(msqid)) {
1322 DPRINTF(("msqid deleted\n"));
1323 error = EIDRM;
1324 goto done2;
1325 }
1326 }
1327
1328 /*
1329 * Return the message to the user.
1330 *
1331 * First, do the bookkeeping (before we risk being interrupted).
1332 */
1333
1334 msqkptr->u.msg_cbytes -= msghdr->msg_ts;
1335 msqkptr->u.msg_qnum--;
1336 msqkptr->u.msg_lrpid = td->td_proc->p_pid;
1337 msqkptr->u.msg_rtime = time_second;
1338
1339 racct_sub_cred(msqkptr->cred, RACCT_MSGQQUEUED, 1);
1340 racct_sub_cred(msqkptr->cred, RACCT_MSGQSIZE, msghdr->msg_ts);
1341
1342 /*
1343 * Make msgsz the actual amount that we'll be returning.
1344 * Note that this effectively truncates the message if it is too long
1345 * (since msgsz is never increased).
1346 */
1347
1348 DPRINTF(("found a message, msgsz=%zu, msg_ts=%hu\n", msgsz,
1349 msghdr->msg_ts));
1350 if (msgsz > msghdr->msg_ts)
1351 msgsz = msghdr->msg_ts;
1352 *mtype = msghdr->msg_type;
1353
1354 /*
1355 * Return the segments to the user
1356 */
1357
1358 next = msghdr->msg_spot;
1359 for (len = 0; len < msgsz; len += msginfo.msgssz) {
1360 size_t tlen;
1361
1362 if (msgsz - len > msginfo.msgssz)
1363 tlen = msginfo.msgssz;
1364 else
1365 tlen = msgsz - len;
1366 if (next <= -1)
1367 panic("next too low #3");
1368 if (next >= msginfo.msgseg)
1369 panic("next out of range #3");
1370 mtx_unlock(&msq_mtx);
1371 error = copyout(&msgpool[next * msginfo.msgssz], msgp, tlen);
1372 mtx_lock(&msq_mtx);
1373 if (error != 0) {
1374 DPRINTF(("error (%d) copying out message segment\n",
1375 error));
1376 msg_freehdr(msghdr);
1377 wakeup(msqkptr);
1378 goto done2;
1379 }
1380 msgp = (char *)msgp + tlen;
1381 next = msgmaps[next].next;
1382 }
1383
1384 /*
1385 * Done, return the actual number of bytes copied out.
1386 */
1387
1388 msg_freehdr(msghdr);
1389 wakeup(msqkptr);
1390 td->td_retval[0] = msgsz;
1391 done2:
1392 mtx_unlock(&msq_mtx);
1393 return (error);
1394 }
1395
1396 int
1397 sys_msgrcv(td, uap)
1398 struct thread *td;
1399 register struct msgrcv_args *uap;
1400 {
1401 int error;
1402 long mtype;
1403
1404 DPRINTF(("call to msgrcv(%d, %p, %zu, %ld, %d)\n", uap->msqid,
1405 uap->msgp, uap->msgsz, uap->msgtyp, uap->msgflg));
1406
1407 if ((error = kern_msgrcv(td, uap->msqid,
1408 (char *)uap->msgp + sizeof(mtype), uap->msgsz,
1409 uap->msgtyp, uap->msgflg, &mtype)) != 0)
1410 return (error);
1411 if ((error = copyout(&mtype, uap->msgp, sizeof(mtype))) != 0)
1412 DPRINTF(("error %d copying the message type\n", error));
1413 return (error);
1414 }
1415
1416 static int
1417 sysctl_msqids(SYSCTL_HANDLER_ARGS)
1418 {
1419 struct msqid_kernel tmsqk;
1420 struct prison *pr, *rpr;
1421 int error, i;
1422
1423 pr = req->td->td_ucred->cr_prison;
1424 rpr = msg_find_prison(req->td->td_ucred);
1425 error = 0;
1426 for (i = 0; i < msginfo.msgmni; i++) {
1427 mtx_lock(&msq_mtx);
1428 if (msqids[i].u.msg_qbytes == 0 || rpr == NULL ||
1429 msq_prison_cansee(rpr, &msqids[i]) != 0)
1430 bzero(&tmsqk, sizeof(tmsqk));
1431 else {
1432 tmsqk = msqids[i];
1433 if (tmsqk.cred->cr_prison != pr)
1434 tmsqk.u.msg_perm.key = IPC_PRIVATE;
1435 }
1436 mtx_unlock(&msq_mtx);
1437 error = SYSCTL_OUT(req, &tmsqk, sizeof(tmsqk));
1438 if (error != 0)
1439 break;
1440 }
1441 return (error);
1442 }
1443
1444 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmax, CTLFLAG_RD, &msginfo.msgmax, 0,
1445 "Maximum message size");
1446 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmni, CTLFLAG_RDTUN, &msginfo.msgmni, 0,
1447 "Number of message queue identifiers");
1448 SYSCTL_INT(_kern_ipc, OID_AUTO, msgmnb, CTLFLAG_RDTUN, &msginfo.msgmnb, 0,
1449 "Maximum number of bytes in a queue");
1450 SYSCTL_INT(_kern_ipc, OID_AUTO, msgtql, CTLFLAG_RDTUN, &msginfo.msgtql, 0,
1451 "Maximum number of messages in the system");
1452 SYSCTL_INT(_kern_ipc, OID_AUTO, msgssz, CTLFLAG_RDTUN, &msginfo.msgssz, 0,
1453 "Size of a message segment");
1454 SYSCTL_INT(_kern_ipc, OID_AUTO, msgseg, CTLFLAG_RDTUN, &msginfo.msgseg, 0,
1455 "Number of message segments");
1456 SYSCTL_PROC(_kern_ipc, OID_AUTO, msqids,
1457 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
1458 NULL, 0, sysctl_msqids, "", "Message queue IDs");
1459
1460 static int
1461 msg_prison_check(void *obj, void *data)
1462 {
1463 struct prison *pr = obj;
1464 struct prison *prpr;
1465 struct vfsoptlist *opts = data;
1466 int error, jsys;
1467
1468 /*
1469 * sysvmsg is a jailsys integer.
1470 * It must be "disable" if the parent jail is disabled.
1471 */
1472 error = vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys));
1473 if (error != ENOENT) {
1474 if (error != 0)
1475 return (error);
1476 switch (jsys) {
1477 case JAIL_SYS_DISABLE:
1478 break;
1479 case JAIL_SYS_NEW:
1480 case JAIL_SYS_INHERIT:
1481 prison_lock(pr->pr_parent);
1482 prpr = osd_jail_get(pr->pr_parent, msg_prison_slot);
1483 prison_unlock(pr->pr_parent);
1484 if (prpr == NULL)
1485 return (EPERM);
1486 break;
1487 default:
1488 return (EINVAL);
1489 }
1490 }
1491
1492 return (0);
1493 }
1494
1495 static int
1496 msg_prison_set(void *obj, void *data)
1497 {
1498 struct prison *pr = obj;
1499 struct prison *tpr, *orpr, *nrpr, *trpr;
1500 struct vfsoptlist *opts = data;
1501 void *rsv;
1502 int jsys, descend;
1503
1504 /*
1505 * sysvmsg controls which jail is the root of the associated msgs (this
1506 * jail or same as the parent), or if the feature is available at all.
1507 */
1508 if (vfs_copyopt(opts, "sysvmsg", &jsys, sizeof(jsys)) == ENOENT)
1509 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1510 ? JAIL_SYS_INHERIT
1511 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1512 ? JAIL_SYS_DISABLE
1513 : -1;
1514 if (jsys == JAIL_SYS_DISABLE) {
1515 prison_lock(pr);
1516 orpr = osd_jail_get(pr, msg_prison_slot);
1517 if (orpr != NULL)
1518 osd_jail_del(pr, msg_prison_slot);
1519 prison_unlock(pr);
1520 if (orpr != NULL) {
1521 if (orpr == pr)
1522 msg_prison_cleanup(pr);
1523 /* Disable all child jails as well. */
1524 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1525 prison_lock(tpr);
1526 trpr = osd_jail_get(tpr, msg_prison_slot);
1527 if (trpr != NULL) {
1528 osd_jail_del(tpr, msg_prison_slot);
1529 prison_unlock(tpr);
1530 if (trpr == tpr)
1531 msg_prison_cleanup(tpr);
1532 } else {
1533 prison_unlock(tpr);
1534 descend = 0;
1535 }
1536 }
1537 }
1538 } else if (jsys != -1) {
1539 if (jsys == JAIL_SYS_NEW)
1540 nrpr = pr;
1541 else {
1542 prison_lock(pr->pr_parent);
1543 nrpr = osd_jail_get(pr->pr_parent, msg_prison_slot);
1544 prison_unlock(pr->pr_parent);
1545 }
1546 rsv = osd_reserve(msg_prison_slot);
1547 prison_lock(pr);
1548 orpr = osd_jail_get(pr, msg_prison_slot);
1549 if (orpr != nrpr)
1550 (void)osd_jail_set_reserved(pr, msg_prison_slot, rsv,
1551 nrpr);
1552 else
1553 osd_free_reserved(rsv);
1554 prison_unlock(pr);
1555 if (orpr != nrpr) {
1556 if (orpr == pr)
1557 msg_prison_cleanup(pr);
1558 if (orpr != NULL) {
1559 /* Change child jails matching the old root, */
1560 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1561 prison_lock(tpr);
1562 trpr = osd_jail_get(tpr,
1563 msg_prison_slot);
1564 if (trpr == orpr) {
1565 (void)osd_jail_set(tpr,
1566 msg_prison_slot, nrpr);
1567 prison_unlock(tpr);
1568 if (trpr == tpr)
1569 msg_prison_cleanup(tpr);
1570 } else {
1571 prison_unlock(tpr);
1572 descend = 0;
1573 }
1574 }
1575 }
1576 }
1577 }
1578
1579 return (0);
1580 }
1581
1582 static int
1583 msg_prison_get(void *obj, void *data)
1584 {
1585 struct prison *pr = obj;
1586 struct prison *rpr;
1587 struct vfsoptlist *opts = data;
1588 int error, jsys;
1589
1590 /* Set sysvmsg based on the jail's root prison. */
1591 prison_lock(pr);
1592 rpr = osd_jail_get(pr, msg_prison_slot);
1593 prison_unlock(pr);
1594 jsys = rpr == NULL ? JAIL_SYS_DISABLE
1595 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1596 error = vfs_setopt(opts, "sysvmsg", &jsys, sizeof(jsys));
1597 if (error == ENOENT)
1598 error = 0;
1599 return (error);
1600 }
1601
1602 static int
1603 msg_prison_remove(void *obj, void *data __unused)
1604 {
1605 struct prison *pr = obj;
1606 struct prison *rpr;
1607
1608 prison_lock(pr);
1609 rpr = osd_jail_get(pr, msg_prison_slot);
1610 prison_unlock(pr);
1611 if (rpr == pr)
1612 msg_prison_cleanup(pr);
1613 return (0);
1614 }
1615
1616 static void
1617 msg_prison_cleanup(struct prison *pr)
1618 {
1619 struct msqid_kernel *msqkptr;
1620 int i;
1621
1622 /* Remove any msqs that belong to this jail. */
1623 mtx_lock(&msq_mtx);
1624 for (i = 0; i < msginfo.msgmni; i++) {
1625 msqkptr = &msqids[i];
1626 if (msqkptr->u.msg_qbytes != 0 &&
1627 msqkptr->cred != NULL && msqkptr->cred->cr_prison == pr)
1628 msq_remove(msqkptr);
1629 }
1630 mtx_unlock(&msq_mtx);
1631 }
1632
1633 SYSCTL_JAIL_PARAM_SYS_NODE(sysvmsg, CTLFLAG_RW, "SYSV message queues");
1634
1635 #ifdef COMPAT_FREEBSD32
1636 int
1637 freebsd32_msgsys(struct thread *td, struct freebsd32_msgsys_args *uap)
1638 {
1639
1640 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1641 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1642 switch (uap->which) {
1643 case 0:
1644 return (freebsd7_freebsd32_msgctl(td,
1645 (struct freebsd7_freebsd32_msgctl_args *)&uap->a2));
1646 case 2:
1647 return (freebsd32_msgsnd(td,
1648 (struct freebsd32_msgsnd_args *)&uap->a2));
1649 case 3:
1650 return (freebsd32_msgrcv(td,
1651 (struct freebsd32_msgrcv_args *)&uap->a2));
1652 default:
1653 return (sys_msgsys(td, (struct msgsys_args *)uap));
1654 }
1655 #else
1656 return (nosys(td, NULL));
1657 #endif
1658 }
1659
1660 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1661 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1662 int
1663 freebsd7_freebsd32_msgctl(struct thread *td,
1664 struct freebsd7_freebsd32_msgctl_args *uap)
1665 {
1666 struct msqid_ds msqbuf;
1667 struct msqid_ds32_old msqbuf32;
1668 int error;
1669
1670 if (uap->cmd == IPC_SET) {
1671 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1672 if (error)
1673 return (error);
1674 freebsd32_ipcperm_old_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1675 PTRIN_CP(msqbuf32, msqbuf, msg_first);
1676 PTRIN_CP(msqbuf32, msqbuf, msg_last);
1677 CP(msqbuf32, msqbuf, msg_cbytes);
1678 CP(msqbuf32, msqbuf, msg_qnum);
1679 CP(msqbuf32, msqbuf, msg_qbytes);
1680 CP(msqbuf32, msqbuf, msg_lspid);
1681 CP(msqbuf32, msqbuf, msg_lrpid);
1682 CP(msqbuf32, msqbuf, msg_stime);
1683 CP(msqbuf32, msqbuf, msg_rtime);
1684 CP(msqbuf32, msqbuf, msg_ctime);
1685 }
1686 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1687 if (error)
1688 return (error);
1689 if (uap->cmd == IPC_STAT) {
1690 bzero(&msqbuf32, sizeof(msqbuf32));
1691 freebsd32_ipcperm_old_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1692 PTROUT_CP(msqbuf, msqbuf32, msg_first);
1693 PTROUT_CP(msqbuf, msqbuf32, msg_last);
1694 CP(msqbuf, msqbuf32, msg_cbytes);
1695 CP(msqbuf, msqbuf32, msg_qnum);
1696 CP(msqbuf, msqbuf32, msg_qbytes);
1697 CP(msqbuf, msqbuf32, msg_lspid);
1698 CP(msqbuf, msqbuf32, msg_lrpid);
1699 CP(msqbuf, msqbuf32, msg_stime);
1700 CP(msqbuf, msqbuf32, msg_rtime);
1701 CP(msqbuf, msqbuf32, msg_ctime);
1702 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1703 }
1704 return (error);
1705 }
1706 #endif
1707
1708 int
1709 freebsd32_msgctl(struct thread *td, struct freebsd32_msgctl_args *uap)
1710 {
1711 struct msqid_ds msqbuf;
1712 struct msqid_ds32 msqbuf32;
1713 int error;
1714
1715 if (uap->cmd == IPC_SET) {
1716 error = copyin(uap->buf, &msqbuf32, sizeof(msqbuf32));
1717 if (error)
1718 return (error);
1719 freebsd32_ipcperm_in(&msqbuf32.msg_perm, &msqbuf.msg_perm);
1720 PTRIN_CP(msqbuf32, msqbuf, msg_first);
1721 PTRIN_CP(msqbuf32, msqbuf, msg_last);
1722 CP(msqbuf32, msqbuf, msg_cbytes);
1723 CP(msqbuf32, msqbuf, msg_qnum);
1724 CP(msqbuf32, msqbuf, msg_qbytes);
1725 CP(msqbuf32, msqbuf, msg_lspid);
1726 CP(msqbuf32, msqbuf, msg_lrpid);
1727 CP(msqbuf32, msqbuf, msg_stime);
1728 CP(msqbuf32, msqbuf, msg_rtime);
1729 CP(msqbuf32, msqbuf, msg_ctime);
1730 }
1731 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1732 if (error)
1733 return (error);
1734 if (uap->cmd == IPC_STAT) {
1735 freebsd32_ipcperm_out(&msqbuf.msg_perm, &msqbuf32.msg_perm);
1736 PTROUT_CP(msqbuf, msqbuf32, msg_first);
1737 PTROUT_CP(msqbuf, msqbuf32, msg_last);
1738 CP(msqbuf, msqbuf32, msg_cbytes);
1739 CP(msqbuf, msqbuf32, msg_qnum);
1740 CP(msqbuf, msqbuf32, msg_qbytes);
1741 CP(msqbuf, msqbuf32, msg_lspid);
1742 CP(msqbuf, msqbuf32, msg_lrpid);
1743 CP(msqbuf, msqbuf32, msg_stime);
1744 CP(msqbuf, msqbuf32, msg_rtime);
1745 CP(msqbuf, msqbuf32, msg_ctime);
1746 error = copyout(&msqbuf32, uap->buf, sizeof(struct msqid_ds32));
1747 }
1748 return (error);
1749 }
1750
1751 int
1752 freebsd32_msgsnd(struct thread *td, struct freebsd32_msgsnd_args *uap)
1753 {
1754 const void *msgp;
1755 long mtype;
1756 int32_t mtype32;
1757 int error;
1758
1759 msgp = PTRIN(uap->msgp);
1760 if ((error = copyin(msgp, &mtype32, sizeof(mtype32))) != 0)
1761 return (error);
1762 mtype = mtype32;
1763 return (kern_msgsnd(td, uap->msqid,
1764 (const char *)msgp + sizeof(mtype32),
1765 uap->msgsz, uap->msgflg, mtype));
1766 }
1767
1768 int
1769 freebsd32_msgrcv(struct thread *td, struct freebsd32_msgrcv_args *uap)
1770 {
1771 void *msgp;
1772 long mtype;
1773 int32_t mtype32;
1774 int error;
1775
1776 msgp = PTRIN(uap->msgp);
1777 if ((error = kern_msgrcv(td, uap->msqid,
1778 (char *)msgp + sizeof(mtype32), uap->msgsz,
1779 uap->msgtyp, uap->msgflg, &mtype)) != 0)
1780 return (error);
1781 mtype32 = (int32_t)mtype;
1782 return (copyout(&mtype32, msgp, sizeof(mtype32)));
1783 }
1784 #endif
1785
1786 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1787 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1788
1789 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1790 static sy_call_t *msgcalls[] = {
1791 (sy_call_t *)freebsd7_msgctl, (sy_call_t *)sys_msgget,
1792 (sy_call_t *)sys_msgsnd, (sy_call_t *)sys_msgrcv
1793 };
1794
1795 /*
1796 * Entry point for all MSG calls.
1797 */
1798 int
1799 sys_msgsys(td, uap)
1800 struct thread *td;
1801 /* XXX actually varargs. */
1802 struct msgsys_args /* {
1803 int which;
1804 int a2;
1805 int a3;
1806 int a4;
1807 int a5;
1808 int a6;
1809 } */ *uap;
1810 {
1811 int error;
1812
1813 if (uap->which < 0 || uap->which >= nitems(msgcalls))
1814 return (EINVAL);
1815 error = (*msgcalls[uap->which])(td, &uap->a2);
1816 return (error);
1817 }
1818
1819 #ifndef CP
1820 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0)
1821 #endif
1822
1823 #ifndef _SYS_SYSPROTO_H_
1824 struct freebsd7_msgctl_args {
1825 int msqid;
1826 int cmd;
1827 struct msqid_ds_old *buf;
1828 };
1829 #endif
1830 int
1831 freebsd7_msgctl(td, uap)
1832 struct thread *td;
1833 struct freebsd7_msgctl_args *uap;
1834 {
1835 struct msqid_ds_old msqold;
1836 struct msqid_ds msqbuf;
1837 int error;
1838
1839 DPRINTF(("call to freebsd7_msgctl(%d, %d, %p)\n", uap->msqid, uap->cmd,
1840 uap->buf));
1841 if (uap->cmd == IPC_SET) {
1842 error = copyin(uap->buf, &msqold, sizeof(msqold));
1843 if (error)
1844 return (error);
1845 ipcperm_old2new(&msqold.msg_perm, &msqbuf.msg_perm);
1846 CP(msqold, msqbuf, msg_first);
1847 CP(msqold, msqbuf, msg_last);
1848 CP(msqold, msqbuf, msg_cbytes);
1849 CP(msqold, msqbuf, msg_qnum);
1850 CP(msqold, msqbuf, msg_qbytes);
1851 CP(msqold, msqbuf, msg_lspid);
1852 CP(msqold, msqbuf, msg_lrpid);
1853 CP(msqold, msqbuf, msg_stime);
1854 CP(msqold, msqbuf, msg_rtime);
1855 CP(msqold, msqbuf, msg_ctime);
1856 }
1857 error = kern_msgctl(td, uap->msqid, uap->cmd, &msqbuf);
1858 if (error)
1859 return (error);
1860 if (uap->cmd == IPC_STAT) {
1861 bzero(&msqold, sizeof(msqold));
1862 ipcperm_new2old(&msqbuf.msg_perm, &msqold.msg_perm);
1863 CP(msqbuf, msqold, msg_first);
1864 CP(msqbuf, msqold, msg_last);
1865 CP(msqbuf, msqold, msg_cbytes);
1866 CP(msqbuf, msqold, msg_qnum);
1867 CP(msqbuf, msqold, msg_qbytes);
1868 CP(msqbuf, msqold, msg_lspid);
1869 CP(msqbuf, msqold, msg_lrpid);
1870 CP(msqbuf, msqold, msg_stime);
1871 CP(msqbuf, msqold, msg_rtime);
1872 CP(msqbuf, msqold, msg_ctime);
1873 error = copyout(&msqold, uap->buf, sizeof(struct msqid_ds_old));
1874 }
1875 return (error);
1876 }
1877
1878 #undef CP
1879
1880 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1881 COMPAT_FREEBSD7 */
Cache object: 8dfe26136bf92194bff7ea188b6b5d89
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