kern_jail.c revision 168399 
1/*-
2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
8 */
9
10#include <sys/cdefs.h>
11__FBSDID("$FreeBSD: head/sys/kern/kern_jail.c 168399 2007-04-05 21:34:54Z pjd $");
12
13#include "opt_mac.h"
14
15#include <sys/param.h>
16#include <sys/types.h>
17#include <sys/kernel.h>
18#include <sys/systm.h>
19#include <sys/errno.h>
20#include <sys/sysproto.h>
21#include <sys/malloc.h>
22#include <sys/priv.h>
23#include <sys/proc.h>
24#include <sys/taskqueue.h>
25#include <sys/jail.h>
26#include <sys/lock.h>
27#include <sys/mutex.h>
28#include <sys/namei.h>
29#include <sys/mount.h>
30#include <sys/queue.h>
31#include <sys/socket.h>
32#include <sys/syscallsubr.h>
33#include <sys/sysctl.h>
34#include <sys/vnode.h>
35#include <net/if.h>
36#include <netinet/in.h>
37
38#include <security/mac/mac_framework.h>
39
40MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
41
42SYSCTL_NODE(_security, OID_AUTO, jail, CTLFLAG_RW, 0,
43    "Jail rules");
44
45int	jail_set_hostname_allowed = 1;
46SYSCTL_INT(_security_jail, OID_AUTO, set_hostname_allowed, CTLFLAG_RW,
47    &jail_set_hostname_allowed, 0,
48    "Processes in jail can set their hostnames");
49
50int	jail_socket_unixiproute_only = 1;
51SYSCTL_INT(_security_jail, OID_AUTO, socket_unixiproute_only, CTLFLAG_RW,
52    &jail_socket_unixiproute_only, 0,
53    "Processes in jail are limited to creating UNIX/IPv4/route sockets only");
54
55int	jail_sysvipc_allowed = 0;
56SYSCTL_INT(_security_jail, OID_AUTO, sysvipc_allowed, CTLFLAG_RW,
57    &jail_sysvipc_allowed, 0,
58    "Processes in jail can use System V IPC primitives");
59
60static int jail_enforce_statfs = 2;
61SYSCTL_INT(_security_jail, OID_AUTO, enforce_statfs, CTLFLAG_RW,
62    &jail_enforce_statfs, 0,
63    "Processes in jail cannot see all mounted file systems");
64
65int	jail_allow_raw_sockets = 0;
66SYSCTL_INT(_security_jail, OID_AUTO, allow_raw_sockets, CTLFLAG_RW,
67    &jail_allow_raw_sockets, 0,
68    "Prison root can create raw sockets");
69
70int	jail_chflags_allowed = 0;
71SYSCTL_INT(_security_jail, OID_AUTO, chflags_allowed, CTLFLAG_RW,
72    &jail_chflags_allowed, 0,
73    "Processes in jail can alter system file flags");
74
75int	jail_mount_allowed = 0;
76SYSCTL_INT(_security_jail, OID_AUTO, mount_allowed, CTLFLAG_RW,
77    &jail_mount_allowed, 0,
78    "Processes in jail can mount/unmount jail-friendly file systems");
79
80/* allprison, lastprid, and prisoncount are protected by allprison_mtx. */
81struct	prisonlist allprison;
82struct	mtx allprison_mtx;
83int	lastprid = 0;
84int	prisoncount = 0;
85
86static void		 init_prison(void *);
87static void		 prison_complete(void *context, int pending);
88static int		 sysctl_jail_list(SYSCTL_HANDLER_ARGS);
89
90static void
91init_prison(void *data __unused)
92{
93
94	mtx_init(&allprison_mtx, "allprison", NULL, MTX_DEF);
95	LIST_INIT(&allprison);
96}
97
98SYSINIT(prison, SI_SUB_INTRINSIC, SI_ORDER_ANY, init_prison, NULL);
99
100/*
101 * struct jail_args {
102 *	struct jail *jail;
103 * };
104 */
105int
106jail(struct thread *td, struct jail_args *uap)
107{
108	struct nameidata nd;
109	struct prison *pr, *tpr;
110	struct jail j;
111	struct jail_attach_args jaa;
112	int vfslocked, error, tryprid;
113
114	error = copyin(uap->jail, &j, sizeof(j));
115	if (error)
116		return (error);
117	if (j.version != 0)
118		return (EINVAL);
119
120	MALLOC(pr, struct prison *, sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO);
121	mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF);
122	pr->pr_ref = 1;
123	error = copyinstr(j.path, &pr->pr_path, sizeof(pr->pr_path), 0);
124	if (error)
125		goto e_killmtx;
126	NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE,
127	    pr->pr_path, td);
128	error = namei(&nd);
129	if (error)
130		goto e_killmtx;
131	vfslocked = NDHASGIANT(&nd);
132	pr->pr_root = nd.ni_vp;
133	VOP_UNLOCK(nd.ni_vp, 0, td);
134	NDFREE(&nd, NDF_ONLY_PNBUF);
135	VFS_UNLOCK_GIANT(vfslocked);
136	error = copyinstr(j.hostname, &pr->pr_host, sizeof(pr->pr_host), 0);
137	if (error)
138		goto e_dropvnref;
139	pr->pr_ip = j.ip_number;
140	pr->pr_linux = NULL;
141	pr->pr_securelevel = securelevel;
142
143	/* Determine next pr_id and add prison to allprison list. */
144	mtx_lock(&allprison_mtx);
145	tryprid = lastprid + 1;
146	if (tryprid == JAIL_MAX)
147		tryprid = 1;
148next:
149	LIST_FOREACH(tpr, &allprison, pr_list) {
150		if (tpr->pr_id == tryprid) {
151			tryprid++;
152			if (tryprid == JAIL_MAX) {
153				mtx_unlock(&allprison_mtx);
154				error = EAGAIN;
155				goto e_dropvnref;
156			}
157			goto next;
158		}
159	}
160	pr->pr_id = jaa.jid = lastprid = tryprid;
161	LIST_INSERT_HEAD(&allprison, pr, pr_list);
162	prisoncount++;
163	mtx_unlock(&allprison_mtx);
164
165	error = jail_attach(td, &jaa);
166	if (error)
167		goto e_dropprref;
168	mtx_lock(&pr->pr_mtx);
169	pr->pr_ref--;
170	mtx_unlock(&pr->pr_mtx);
171	td->td_retval[0] = jaa.jid;
172	return (0);
173e_dropprref:
174	mtx_lock(&allprison_mtx);
175	LIST_REMOVE(pr, pr_list);
176	prisoncount--;
177	mtx_unlock(&allprison_mtx);
178e_dropvnref:
179	vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
180	vrele(pr->pr_root);
181	VFS_UNLOCK_GIANT(vfslocked);
182e_killmtx:
183	mtx_destroy(&pr->pr_mtx);
184	FREE(pr, M_PRISON);
185	return (error);
186}
187
188/*
189 * struct jail_attach_args {
190 *	int jid;
191 * };
192 */
193int
194jail_attach(struct thread *td, struct jail_attach_args *uap)
195{
196	struct proc *p;
197	struct ucred *newcred, *oldcred;
198	struct prison *pr;
199	int vfslocked, error;
200
201	/*
202	 * XXX: Note that there is a slight race here if two threads
203	 * in the same privileged process attempt to attach to two
204	 * different jails at the same time.  It is important for
205	 * user processes not to do this, or they might end up with
206	 * a process root from one prison, but attached to the jail
207	 * of another.
208	 */
209	error = priv_check(td, PRIV_JAIL_ATTACH);
210	if (error)
211		return (error);
212
213	p = td->td_proc;
214	mtx_lock(&allprison_mtx);
215	pr = prison_find(uap->jid);
216	if (pr == NULL) {
217		mtx_unlock(&allprison_mtx);
218		return (EINVAL);
219	}
220	pr->pr_ref++;
221	mtx_unlock(&pr->pr_mtx);
222	mtx_unlock(&allprison_mtx);
223
224	vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
225	vn_lock(pr->pr_root, LK_EXCLUSIVE | LK_RETRY, td);
226	if ((error = change_dir(pr->pr_root, td)) != 0)
227		goto e_unlock;
228#ifdef MAC
229	if ((error = mac_check_vnode_chroot(td->td_ucred, pr->pr_root)))
230		goto e_unlock;
231#endif
232	VOP_UNLOCK(pr->pr_root, 0, td);
233	change_root(pr->pr_root, td);
234	VFS_UNLOCK_GIANT(vfslocked);
235
236	newcred = crget();
237	PROC_LOCK(p);
238	oldcred = p->p_ucred;
239	setsugid(p);
240	crcopy(newcred, oldcred);
241	newcred->cr_prison = pr;
242	p->p_ucred = newcred;
243	PROC_UNLOCK(p);
244	crfree(oldcred);
245	return (0);
246e_unlock:
247	VOP_UNLOCK(pr->pr_root, 0, td);
248	VFS_UNLOCK_GIANT(vfslocked);
249	mtx_lock(&pr->pr_mtx);
250	pr->pr_ref--;
251	mtx_unlock(&pr->pr_mtx);
252	return (error);
253}
254
255/*
256 * Returns a locked prison instance, or NULL on failure.
257 */
258struct prison *
259prison_find(int prid)
260{
261	struct prison *pr;
262
263	mtx_assert(&allprison_mtx, MA_OWNED);
264	LIST_FOREACH(pr, &allprison, pr_list) {
265		if (pr->pr_id == prid) {
266			mtx_lock(&pr->pr_mtx);
267			return (pr);
268		}
269	}
270	return (NULL);
271}
272
273void
274prison_free(struct prison *pr)
275{
276
277	mtx_lock(&allprison_mtx);
278	mtx_lock(&pr->pr_mtx);
279	pr->pr_ref--;
280	if (pr->pr_ref == 0) {
281		LIST_REMOVE(pr, pr_list);
282		mtx_unlock(&pr->pr_mtx);
283		prisoncount--;
284		mtx_unlock(&allprison_mtx);
285
286		TASK_INIT(&pr->pr_task, 0, prison_complete, pr);
287		taskqueue_enqueue(taskqueue_thread, &pr->pr_task);
288		return;
289	}
290	mtx_unlock(&pr->pr_mtx);
291	mtx_unlock(&allprison_mtx);
292}
293
294static void
295prison_complete(void *context, int pending)
296{
297	struct prison *pr;
298	int vfslocked;
299
300	pr = (struct prison *)context;
301
302	vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
303	vrele(pr->pr_root);
304	VFS_UNLOCK_GIANT(vfslocked);
305
306	mtx_destroy(&pr->pr_mtx);
307	if (pr->pr_linux != NULL)
308		FREE(pr->pr_linux, M_PRISON);
309	FREE(pr, M_PRISON);
310}
311
312void
313prison_hold(struct prison *pr)
314{
315
316	mtx_lock(&pr->pr_mtx);
317	pr->pr_ref++;
318	mtx_unlock(&pr->pr_mtx);
319}
320
321u_int32_t
322prison_getip(struct ucred *cred)
323{
324
325	return (cred->cr_prison->pr_ip);
326}
327
328int
329prison_ip(struct ucred *cred, int flag, u_int32_t *ip)
330{
331	u_int32_t tmp;
332
333	if (!jailed(cred))
334		return (0);
335	if (flag)
336		tmp = *ip;
337	else
338		tmp = ntohl(*ip);
339	if (tmp == INADDR_ANY) {
340		if (flag)
341			*ip = cred->cr_prison->pr_ip;
342		else
343			*ip = htonl(cred->cr_prison->pr_ip);
344		return (0);
345	}
346	if (tmp == INADDR_LOOPBACK) {
347		if (flag)
348			*ip = cred->cr_prison->pr_ip;
349		else
350			*ip = htonl(cred->cr_prison->pr_ip);
351		return (0);
352	}
353	if (cred->cr_prison->pr_ip != tmp)
354		return (1);
355	return (0);
356}
357
358void
359prison_remote_ip(struct ucred *cred, int flag, u_int32_t *ip)
360{
361	u_int32_t tmp;
362
363	if (!jailed(cred))
364		return;
365	if (flag)
366		tmp = *ip;
367	else
368		tmp = ntohl(*ip);
369	if (tmp == INADDR_LOOPBACK) {
370		if (flag)
371			*ip = cred->cr_prison->pr_ip;
372		else
373			*ip = htonl(cred->cr_prison->pr_ip);
374		return;
375	}
376	return;
377}
378
379int
380prison_if(struct ucred *cred, struct sockaddr *sa)
381{
382	struct sockaddr_in *sai;
383	int ok;
384
385	sai = (struct sockaddr_in *)sa;
386	if ((sai->sin_family != AF_INET) && jail_socket_unixiproute_only)
387		ok = 1;
388	else if (sai->sin_family != AF_INET)
389		ok = 0;
390	else if (cred->cr_prison->pr_ip != ntohl(sai->sin_addr.s_addr))
391		ok = 1;
392	else
393		ok = 0;
394	return (ok);
395}
396
397/*
398 * Return 0 if jails permit p1 to frob p2, otherwise ESRCH.
399 */
400int
401prison_check(struct ucred *cred1, struct ucred *cred2)
402{
403
404	if (jailed(cred1)) {
405		if (!jailed(cred2))
406			return (ESRCH);
407		if (cred2->cr_prison != cred1->cr_prison)
408			return (ESRCH);
409	}
410
411	return (0);
412}
413
414/*
415 * Return 1 if the passed credential is in a jail, otherwise 0.
416 */
417int
418jailed(struct ucred *cred)
419{
420
421	return (cred->cr_prison != NULL);
422}
423
424/*
425 * Return the correct hostname for the passed credential.
426 */
427void
428getcredhostname(struct ucred *cred, char *buf, size_t size)
429{
430
431	if (jailed(cred)) {
432		mtx_lock(&cred->cr_prison->pr_mtx);
433		strlcpy(buf, cred->cr_prison->pr_host, size);
434		mtx_unlock(&cred->cr_prison->pr_mtx);
435	} else
436		strlcpy(buf, hostname, size);
437}
438
439/*
440 * Determine whether the subject represented by cred can "see"
441 * status of a mount point.
442 * Returns: 0 for permitted, ENOENT otherwise.
443 * XXX: This function should be called cr_canseemount() and should be
444 *      placed in kern_prot.c.
445 */
446int
447prison_canseemount(struct ucred *cred, struct mount *mp)
448{
449	struct prison *pr;
450	struct statfs *sp;
451	size_t len;
452
453	if (!jailed(cred) || jail_enforce_statfs == 0)
454		return (0);
455	pr = cred->cr_prison;
456	if (pr->pr_root->v_mount == mp)
457		return (0);
458	if (jail_enforce_statfs == 2)
459		return (ENOENT);
460	/*
461	 * If jail's chroot directory is set to "/" we should be able to see
462	 * all mount-points from inside a jail.
463	 * This is ugly check, but this is the only situation when jail's
464	 * directory ends with '/'.
465	 */
466	if (strcmp(pr->pr_path, "/") == 0)
467		return (0);
468	len = strlen(pr->pr_path);
469	sp = &mp->mnt_stat;
470	if (strncmp(pr->pr_path, sp->f_mntonname, len) != 0)
471		return (ENOENT);
472	/*
473	 * Be sure that we don't have situation where jail's root directory
474	 * is "/some/path" and mount point is "/some/pathpath".
475	 */
476	if (sp->f_mntonname[len] != '\0' && sp->f_mntonname[len] != '/')
477		return (ENOENT);
478	return (0);
479}
480
481void
482prison_enforce_statfs(struct ucred *cred, struct mount *mp, struct statfs *sp)
483{
484	char jpath[MAXPATHLEN];
485	struct prison *pr;
486	size_t len;
487
488	if (!jailed(cred) || jail_enforce_statfs == 0)
489		return;
490	pr = cred->cr_prison;
491	if (prison_canseemount(cred, mp) != 0) {
492		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
493		strlcpy(sp->f_mntonname, "[restricted]",
494		    sizeof(sp->f_mntonname));
495		return;
496	}
497	if (pr->pr_root->v_mount == mp) {
498		/*
499		 * Clear current buffer data, so we are sure nothing from
500		 * the valid path left there.
501		 */
502		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
503		*sp->f_mntonname = '/';
504		return;
505	}
506	/*
507	 * If jail's chroot directory is set to "/" we should be able to see
508	 * all mount-points from inside a jail.
509	 */
510	if (strcmp(pr->pr_path, "/") == 0)
511		return;
512	len = strlen(pr->pr_path);
513	strlcpy(jpath, sp->f_mntonname + len, sizeof(jpath));
514	/*
515	 * Clear current buffer data, so we are sure nothing from
516	 * the valid path left there.
517	 */
518	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
519	if (*jpath == '\0') {
520		/* Should never happen. */
521		*sp->f_mntonname = '/';
522	} else {
523		strlcpy(sp->f_mntonname, jpath, sizeof(sp->f_mntonname));
524	}
525}
526
527/*
528 * Check with permission for a specific privilege is granted within jail.  We
529 * have a specific list of accepted privileges; the rest are denied.
530 */
531int
532prison_priv_check(struct ucred *cred, int priv)
533{
534
535	if (!jailed(cred))
536		return (0);
537
538	switch (priv) {
539
540		/*
541		 * Allow ktrace privileges for root in jail.
542		 */
543	case PRIV_KTRACE:
544
545#if 0
546		/*
547		 * Allow jailed processes to configure audit identity and
548		 * submit audit records (login, etc).  In the future we may
549		 * want to further refine the relationship between audit and
550		 * jail.
551		 */
552	case PRIV_AUDIT_GETAUDIT:
553	case PRIV_AUDIT_SETAUDIT:
554	case PRIV_AUDIT_SUBMIT:
555#endif
556
557		/*
558		 * Allow jailed processes to manipulate process UNIX
559		 * credentials in any way they see fit.
560		 */
561	case PRIV_CRED_SETUID:
562	case PRIV_CRED_SETEUID:
563	case PRIV_CRED_SETGID:
564	case PRIV_CRED_SETEGID:
565	case PRIV_CRED_SETGROUPS:
566	case PRIV_CRED_SETREUID:
567	case PRIV_CRED_SETREGID:
568	case PRIV_CRED_SETRESUID:
569	case PRIV_CRED_SETRESGID:
570
571		/*
572		 * Jail implements visibility constraints already, so allow
573		 * jailed root to override uid/gid-based constraints.
574		 */
575	case PRIV_SEEOTHERGIDS:
576	case PRIV_SEEOTHERUIDS:
577
578		/*
579		 * Jail implements inter-process debugging limits already, so
580		 * allow jailed root various debugging privileges.
581		 */
582	case PRIV_DEBUG_DIFFCRED:
583	case PRIV_DEBUG_SUGID:
584	case PRIV_DEBUG_UNPRIV:
585
586		/*
587		 * Allow jail to set various resource limits and login
588		 * properties, and for now, exceed process resource limits.
589		 */
590	case PRIV_PROC_LIMIT:
591	case PRIV_PROC_SETLOGIN:
592	case PRIV_PROC_SETRLIMIT:
593
594		/*
595		 * System V and POSIX IPC privileges are granted in jail.
596		 */
597	case PRIV_IPC_READ:
598	case PRIV_IPC_WRITE:
599	case PRIV_IPC_ADMIN:
600	case PRIV_IPC_MSGSIZE:
601	case PRIV_MQ_ADMIN:
602
603		/*
604		 * Jail implements its own inter-process limits, so allow
605		 * root processes in jail to change scheduling on other
606		 * processes in the same jail.  Likewise for signalling.
607		 */
608	case PRIV_SCHED_DIFFCRED:
609	case PRIV_SIGNAL_DIFFCRED:
610	case PRIV_SIGNAL_SUGID:
611
612		/*
613		 * Allow jailed processes to write to sysctls marked as jail
614		 * writable.
615		 */
616	case PRIV_SYSCTL_WRITEJAIL:
617
618		/*
619		 * Allow root in jail to manage a variety of quota
620		 * properties.  These should likely be conditional on a
621		 * configuration option.
622		 */
623	case PRIV_VFS_GETQUOTA:
624	case PRIV_VFS_SETQUOTA:
625
626		/*
627		 * Since Jail relies on chroot() to implement file system
628		 * protections, grant many VFS privileges to root in jail.
629		 * Be careful to exclude mount-related and NFS-related
630		 * privileges.
631		 */
632	case PRIV_VFS_READ:
633	case PRIV_VFS_WRITE:
634	case PRIV_VFS_ADMIN:
635	case PRIV_VFS_EXEC:
636	case PRIV_VFS_LOOKUP:
637	case PRIV_VFS_BLOCKRESERVE:	/* XXXRW: Slightly surprising. */
638	case PRIV_VFS_CHFLAGS_DEV:
639	case PRIV_VFS_CHOWN:
640	case PRIV_VFS_CHROOT:
641	case PRIV_VFS_RETAINSUGID:
642	case PRIV_VFS_FCHROOT:
643	case PRIV_VFS_LINK:
644	case PRIV_VFS_SETGID:
645	case PRIV_VFS_STICKYFILE:
646		return (0);
647
648		/*
649		 * Depending on the global setting, allow privilege of
650		 * setting system flags.
651		 */
652	case PRIV_VFS_SYSFLAGS:
653		if (jail_chflags_allowed)
654			return (0);
655		else
656			return (EPERM);
657
658		/*
659		 * Depending on the global setting, allow privilege of
660		 * mounting/unmounting file systems.
661		 */
662	case PRIV_VFS_MOUNT:
663	case PRIV_VFS_UNMOUNT:
664	case PRIV_VFS_MOUNT_NONUSER:
665		if (jail_mount_allowed)
666			return (0);
667		else
668			return (EPERM);
669
670		/*
671		 * Allow jailed root to bind reserved ports.
672		 */
673	case PRIV_NETINET_RESERVEDPORT:
674		return (0);
675
676		/*
677		 * Conditionally allow creating raw sockets in jail.
678		 */
679	case PRIV_NETINET_RAW:
680		if (jail_allow_raw_sockets)
681			return (0);
682		else
683			return (EPERM);
684
685		/*
686		 * Since jail implements its own visibility limits on netstat
687		 * sysctls, allow getcred.  This allows identd to work in
688		 * jail.
689		 */
690	case PRIV_NETINET_GETCRED:
691		return (0);
692
693	default:
694		/*
695		 * In all remaining cases, deny the privilege request.  This
696		 * includes almost all network privileges, many system
697		 * configuration privileges.
698		 */
699		return (EPERM);
700	}
701}
702
703static int
704sysctl_jail_list(SYSCTL_HANDLER_ARGS)
705{
706	struct xprison *xp, *sxp;
707	struct prison *pr;
708	int count, error;
709
710	if (jailed(req->td->td_ucred))
711		return (0);
712retry:
713	mtx_lock(&allprison_mtx);
714	count = prisoncount;
715	mtx_unlock(&allprison_mtx);
716
717	if (count == 0)
718		return (0);
719
720	sxp = xp = malloc(sizeof(*xp) * count, M_TEMP, M_WAITOK | M_ZERO);
721	mtx_lock(&allprison_mtx);
722	if (count != prisoncount) {
723		mtx_unlock(&allprison_mtx);
724		free(sxp, M_TEMP);
725		goto retry;
726	}
727
728	LIST_FOREACH(pr, &allprison, pr_list) {
729		mtx_lock(&pr->pr_mtx);
730		xp->pr_version = XPRISON_VERSION;
731		xp->pr_id = pr->pr_id;
732		strlcpy(xp->pr_path, pr->pr_path, sizeof(xp->pr_path));
733		strlcpy(xp->pr_host, pr->pr_host, sizeof(xp->pr_host));
734		xp->pr_ip = pr->pr_ip;
735		mtx_unlock(&pr->pr_mtx);
736		xp++;
737	}
738	mtx_unlock(&allprison_mtx);
739
740	error = SYSCTL_OUT(req, sxp, sizeof(*sxp) * count);
741	free(sxp, M_TEMP);
742	return (error);
743}
744
745SYSCTL_OID(_security_jail, OID_AUTO, list, CTLTYPE_STRUCT | CTLFLAG_RD,
746    NULL, 0, sysctl_jail_list, "S", "List of active jails");
747
748static int
749sysctl_jail_jailed(SYSCTL_HANDLER_ARGS)
750{
751	int error, injail;
752
753	injail = jailed(req->td->td_ucred);
754	error = SYSCTL_OUT(req, &injail, sizeof(injail));
755
756	return (error);
757}
758SYSCTL_PROC(_security_jail, OID_AUTO, jailed, CTLTYPE_INT | CTLFLAG_RD,
759    NULL, 0, sysctl_jail_jailed, "I", "Process in jail?");
760