xref: /freebsd/sys/kern/kern_jail.c (revision 681ce946f33e75c590e97c53076e86dff1fe8f4a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1999 Poul-Henning Kamp.
5  * Copyright (c) 2008 Bjoern A. Zeeb.
6  * Copyright (c) 2009 James Gritton.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include "opt_ddb.h"
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 
38 #include <sys/param.h>
39 #include <sys/types.h>
40 #include <sys/kernel.h>
41 #include <sys/systm.h>
42 #include <sys/errno.h>
43 #include <sys/sysproto.h>
44 #include <sys/malloc.h>
45 #include <sys/osd.h>
46 #include <sys/priv.h>
47 #include <sys/proc.h>
48 #include <sys/taskqueue.h>
49 #include <sys/fcntl.h>
50 #include <sys/jail.h>
51 #include <sys/linker.h>
52 #include <sys/lock.h>
53 #include <sys/mutex.h>
54 #include <sys/racct.h>
55 #include <sys/rctl.h>
56 #include <sys/refcount.h>
57 #include <sys/sx.h>
58 #include <sys/sysent.h>
59 #include <sys/namei.h>
60 #include <sys/mount.h>
61 #include <sys/queue.h>
62 #include <sys/socket.h>
63 #include <sys/syscallsubr.h>
64 #include <sys/sysctl.h>
65 #include <sys/uuid.h>
66 #include <sys/vnode.h>
67 
68 #include <net/if.h>
69 #include <net/vnet.h>
70 
71 #include <netinet/in.h>
72 
73 #ifdef DDB
74 #include <ddb/ddb.h>
75 #endif /* DDB */
76 
77 #include <security/mac/mac_framework.h>
78 
79 #define	PRISON0_HOSTUUID_MODULE	"hostuuid"
80 
81 MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
82 static MALLOC_DEFINE(M_PRISON_RACCT, "prison_racct", "Prison racct structures");
83 
84 /* Keep struct prison prison0 and some code in kern_jail_set() readable. */
85 #ifdef INET
86 #ifdef INET6
87 #define	_PR_IP_SADDRSEL	PR_IP4_SADDRSEL|PR_IP6_SADDRSEL
88 #else
89 #define	_PR_IP_SADDRSEL	PR_IP4_SADDRSEL
90 #endif
91 #else /* !INET */
92 #ifdef INET6
93 #define	_PR_IP_SADDRSEL	PR_IP6_SADDRSEL
94 #else
95 #define	_PR_IP_SADDRSEL	0
96 #endif
97 #endif
98 
99 /* prison0 describes what is "real" about the system. */
100 struct prison prison0 = {
101 	.pr_id		= 0,
102 	.pr_name	= "0",
103 	.pr_ref		= 1,
104 	.pr_uref	= 1,
105 	.pr_path	= "/",
106 	.pr_securelevel	= -1,
107 	.pr_devfs_rsnum = 0,
108 	.pr_state	= PRISON_STATE_ALIVE,
109 	.pr_childmax	= JAIL_MAX,
110 	.pr_hostuuid	= DEFAULT_HOSTUUID,
111 	.pr_children	= LIST_HEAD_INITIALIZER(prison0.pr_children),
112 #ifdef VIMAGE
113 	.pr_flags	= PR_HOST|PR_VNET|_PR_IP_SADDRSEL,
114 #else
115 	.pr_flags	= PR_HOST|_PR_IP_SADDRSEL,
116 #endif
117 	.pr_allow	= PR_ALLOW_ALL_STATIC,
118 };
119 MTX_SYSINIT(prison0, &prison0.pr_mtx, "jail mutex", MTX_DEF);
120 
121 struct bool_flags {
122 	const char	*name;
123 	const char	*noname;
124 	volatile u_int	 flag;
125 };
126 struct jailsys_flags {
127 	const char	*name;
128 	unsigned	 disable;
129 	unsigned	 new;
130 };
131 
132 /* allprison, allprison_racct and lastprid are protected by allprison_lock. */
133 struct	sx allprison_lock;
134 SX_SYSINIT(allprison_lock, &allprison_lock, "allprison");
135 struct	prisonlist allprison = TAILQ_HEAD_INITIALIZER(allprison);
136 LIST_HEAD(, prison_racct) allprison_racct;
137 int	lastprid = 0;
138 
139 static int get_next_prid(struct prison **insprp);
140 static int do_jail_attach(struct thread *td, struct prison *pr, int drflags);
141 static void prison_complete(void *context, int pending);
142 static void prison_deref(struct prison *pr, int flags);
143 static void prison_deref_kill(struct prison *pr, struct prisonlist *freeprison);
144 static int prison_lock_xlock(struct prison *pr, int flags);
145 static void prison_free_not_last(struct prison *pr);
146 static void prison_proc_free_not_last(struct prison *pr);
147 static void prison_set_allow_locked(struct prison *pr, unsigned flag,
148     int enable);
149 static char *prison_path(struct prison *pr1, struct prison *pr2);
150 #ifdef RACCT
151 static void prison_racct_attach(struct prison *pr);
152 static void prison_racct_modify(struct prison *pr);
153 static void prison_racct_detach(struct prison *pr);
154 #endif
155 
156 /* Flags for prison_deref */
157 #define	PD_DEREF	0x01	/* Decrement pr_ref */
158 #define	PD_DEUREF	0x02	/* Decrement pr_uref */
159 #define	PD_KILL		0x04	/* Remove jail, kill processes, etc */
160 #define	PD_LOCKED	0x10	/* pr_mtx is held */
161 #define	PD_LIST_SLOCKED	0x20	/* allprison_lock is held shared */
162 #define	PD_LIST_XLOCKED	0x40	/* allprison_lock is held exclusive */
163 #define PD_OP_FLAGS	0x07	/* Operation flags */
164 #define PD_LOCK_FLAGS	0x70	/* Lock status flags */
165 
166 /*
167  * Parameter names corresponding to PR_* flag values.  Size values are for kvm
168  * as we cannot figure out the size of a sparse array, or an array without a
169  * terminating entry.
170  */
171 static struct bool_flags pr_flag_bool[] = {
172 	{"persist", "nopersist", PR_PERSIST},
173 #ifdef INET
174 	{"ip4.saddrsel", "ip4.nosaddrsel", PR_IP4_SADDRSEL},
175 #endif
176 #ifdef INET6
177 	{"ip6.saddrsel", "ip6.nosaddrsel", PR_IP6_SADDRSEL},
178 #endif
179 };
180 const size_t pr_flag_bool_size = sizeof(pr_flag_bool);
181 
182 static struct jailsys_flags pr_flag_jailsys[] = {
183 	{"host", 0, PR_HOST},
184 #ifdef VIMAGE
185 	{"vnet", 0, PR_VNET},
186 #endif
187 #ifdef INET
188 	{"ip4", PR_IP4_USER, PR_IP4_USER},
189 #endif
190 #ifdef INET6
191 	{"ip6", PR_IP6_USER, PR_IP6_USER},
192 #endif
193 };
194 const size_t pr_flag_jailsys_size = sizeof(pr_flag_jailsys);
195 
196 /*
197  * Make this array full-size so dynamic parameters can be added.
198  * It is protected by prison0.mtx, but lockless reading is allowed
199  * with an atomic check of the flag values.
200  */
201 static struct bool_flags pr_flag_allow[NBBY * NBPW] = {
202 	{"allow.set_hostname", "allow.noset_hostname", PR_ALLOW_SET_HOSTNAME},
203 	{"allow.sysvipc", "allow.nosysvipc", PR_ALLOW_SYSVIPC},
204 	{"allow.raw_sockets", "allow.noraw_sockets", PR_ALLOW_RAW_SOCKETS},
205 	{"allow.chflags", "allow.nochflags", PR_ALLOW_CHFLAGS},
206 	{"allow.mount", "allow.nomount", PR_ALLOW_MOUNT},
207 	{"allow.quotas", "allow.noquotas", PR_ALLOW_QUOTAS},
208 	{"allow.socket_af", "allow.nosocket_af", PR_ALLOW_SOCKET_AF},
209 	{"allow.mlock", "allow.nomlock", PR_ALLOW_MLOCK},
210 	{"allow.reserved_ports", "allow.noreserved_ports",
211 	 PR_ALLOW_RESERVED_PORTS},
212 	{"allow.read_msgbuf", "allow.noread_msgbuf", PR_ALLOW_READ_MSGBUF},
213 	{"allow.unprivileged_proc_debug", "allow.nounprivileged_proc_debug",
214 	 PR_ALLOW_UNPRIV_DEBUG},
215 	{"allow.suser", "allow.nosuser", PR_ALLOW_SUSER},
216 };
217 static unsigned pr_allow_all = PR_ALLOW_ALL_STATIC;
218 const size_t pr_flag_allow_size = sizeof(pr_flag_allow);
219 
220 #define	JAIL_DEFAULT_ALLOW		(PR_ALLOW_SET_HOSTNAME | \
221 					 PR_ALLOW_RESERVED_PORTS | \
222 					 PR_ALLOW_UNPRIV_DEBUG | \
223 					 PR_ALLOW_SUSER)
224 #define	JAIL_DEFAULT_ENFORCE_STATFS	2
225 #define	JAIL_DEFAULT_DEVFS_RSNUM	0
226 static unsigned jail_default_allow = JAIL_DEFAULT_ALLOW;
227 static int jail_default_enforce_statfs = JAIL_DEFAULT_ENFORCE_STATFS;
228 static int jail_default_devfs_rsnum = JAIL_DEFAULT_DEVFS_RSNUM;
229 #if defined(INET) || defined(INET6)
230 static unsigned jail_max_af_ips = 255;
231 #endif
232 
233 /*
234  * Initialize the parts of prison0 that can't be static-initialized with
235  * constants.  This is called from proc0_init() after creating thread0 cpuset.
236  */
237 void
238 prison0_init(void)
239 {
240 	uint8_t *file, *data;
241 	size_t size;
242 
243 	prison0.pr_cpuset = cpuset_ref(thread0.td_cpuset);
244 	prison0.pr_osreldate = osreldate;
245 	strlcpy(prison0.pr_osrelease, osrelease, sizeof(prison0.pr_osrelease));
246 
247 	/* If we have a preloaded hostuuid, use it. */
248 	file = preload_search_by_type(PRISON0_HOSTUUID_MODULE);
249 	if (file != NULL) {
250 		data = preload_fetch_addr(file);
251 		size = preload_fetch_size(file);
252 		if (data != NULL) {
253 			/*
254 			 * The preloaded data may include trailing whitespace, almost
255 			 * certainly a newline; skip over any whitespace or
256 			 * non-printable characters to be safe.
257 			 */
258 			while (size > 0 && data[size - 1] <= 0x20) {
259 				size--;
260 			}
261 			if (validate_uuid(data, size, NULL, 0) == 0) {
262 				(void)strlcpy(prison0.pr_hostuuid, data,
263 				    size + 1);
264 			} else if (bootverbose) {
265 				printf("hostuuid: preload data malformed: '%.*s'\n",
266 				    (int)size, data);
267 			}
268 		}
269 	}
270 	if (bootverbose)
271 		printf("hostuuid: using %s\n", prison0.pr_hostuuid);
272 }
273 
274 /*
275  * struct jail_args {
276  *	struct jail *jail;
277  * };
278  */
279 int
280 sys_jail(struct thread *td, struct jail_args *uap)
281 {
282 	uint32_t version;
283 	int error;
284 	struct jail j;
285 
286 	error = copyin(uap->jail, &version, sizeof(uint32_t));
287 	if (error)
288 		return (error);
289 
290 	switch (version) {
291 	case 0:
292 	{
293 		struct jail_v0 j0;
294 
295 		/* FreeBSD single IPv4 jails. */
296 		bzero(&j, sizeof(struct jail));
297 		error = copyin(uap->jail, &j0, sizeof(struct jail_v0));
298 		if (error)
299 			return (error);
300 		j.version = j0.version;
301 		j.path = j0.path;
302 		j.hostname = j0.hostname;
303 		j.ip4s = htonl(j0.ip_number);	/* jail_v0 is host order */
304 		break;
305 	}
306 
307 	case 1:
308 		/*
309 		 * Version 1 was used by multi-IPv4 jail implementations
310 		 * that never made it into the official kernel.
311 		 */
312 		return (EINVAL);
313 
314 	case 2:	/* JAIL_API_VERSION */
315 		/* FreeBSD multi-IPv4/IPv6,noIP jails. */
316 		error = copyin(uap->jail, &j, sizeof(struct jail));
317 		if (error)
318 			return (error);
319 		break;
320 
321 	default:
322 		/* Sci-Fi jails are not supported, sorry. */
323 		return (EINVAL);
324 	}
325 	return (kern_jail(td, &j));
326 }
327 
328 int
329 kern_jail(struct thread *td, struct jail *j)
330 {
331 	struct iovec optiov[2 * (4 + nitems(pr_flag_allow)
332 #ifdef INET
333 			    + 1
334 #endif
335 #ifdef INET6
336 			    + 1
337 #endif
338 			    )];
339 	struct uio opt;
340 	char *u_path, *u_hostname, *u_name;
341 	struct bool_flags *bf;
342 #ifdef INET
343 	uint32_t ip4s;
344 	struct in_addr *u_ip4;
345 #endif
346 #ifdef INET6
347 	struct in6_addr *u_ip6;
348 #endif
349 	size_t tmplen;
350 	int error, enforce_statfs;
351 
352 	bzero(&optiov, sizeof(optiov));
353 	opt.uio_iov = optiov;
354 	opt.uio_iovcnt = 0;
355 	opt.uio_offset = -1;
356 	opt.uio_resid = -1;
357 	opt.uio_segflg = UIO_SYSSPACE;
358 	opt.uio_rw = UIO_READ;
359 	opt.uio_td = td;
360 
361 	/* Set permissions for top-level jails from sysctls. */
362 	if (!jailed(td->td_ucred)) {
363 		for (bf = pr_flag_allow;
364 		     bf < pr_flag_allow + nitems(pr_flag_allow) &&
365 			atomic_load_int(&bf->flag) != 0;
366 		     bf++) {
367 			optiov[opt.uio_iovcnt].iov_base = __DECONST(char *,
368 			    (jail_default_allow & bf->flag)
369 			    ? bf->name : bf->noname);
370 			optiov[opt.uio_iovcnt].iov_len =
371 			    strlen(optiov[opt.uio_iovcnt].iov_base) + 1;
372 			opt.uio_iovcnt += 2;
373 		}
374 		optiov[opt.uio_iovcnt].iov_base = "enforce_statfs";
375 		optiov[opt.uio_iovcnt].iov_len = sizeof("enforce_statfs");
376 		opt.uio_iovcnt++;
377 		enforce_statfs = jail_default_enforce_statfs;
378 		optiov[opt.uio_iovcnt].iov_base = &enforce_statfs;
379 		optiov[opt.uio_iovcnt].iov_len = sizeof(enforce_statfs);
380 		opt.uio_iovcnt++;
381 	}
382 
383 	tmplen = MAXPATHLEN + MAXHOSTNAMELEN + MAXHOSTNAMELEN;
384 #ifdef INET
385 	ip4s = (j->version == 0) ? 1 : j->ip4s;
386 	if (ip4s > jail_max_af_ips)
387 		return (EINVAL);
388 	tmplen += ip4s * sizeof(struct in_addr);
389 #else
390 	if (j->ip4s > 0)
391 		return (EINVAL);
392 #endif
393 #ifdef INET6
394 	if (j->ip6s > jail_max_af_ips)
395 		return (EINVAL);
396 	tmplen += j->ip6s * sizeof(struct in6_addr);
397 #else
398 	if (j->ip6s > 0)
399 		return (EINVAL);
400 #endif
401 	u_path = malloc(tmplen, M_TEMP, M_WAITOK);
402 	u_hostname = u_path + MAXPATHLEN;
403 	u_name = u_hostname + MAXHOSTNAMELEN;
404 #ifdef INET
405 	u_ip4 = (struct in_addr *)(u_name + MAXHOSTNAMELEN);
406 #endif
407 #ifdef INET6
408 #ifdef INET
409 	u_ip6 = (struct in6_addr *)(u_ip4 + ip4s);
410 #else
411 	u_ip6 = (struct in6_addr *)(u_name + MAXHOSTNAMELEN);
412 #endif
413 #endif
414 	optiov[opt.uio_iovcnt].iov_base = "path";
415 	optiov[opt.uio_iovcnt].iov_len = sizeof("path");
416 	opt.uio_iovcnt++;
417 	optiov[opt.uio_iovcnt].iov_base = u_path;
418 	error = copyinstr(j->path, u_path, MAXPATHLEN,
419 	    &optiov[opt.uio_iovcnt].iov_len);
420 	if (error) {
421 		free(u_path, M_TEMP);
422 		return (error);
423 	}
424 	opt.uio_iovcnt++;
425 	optiov[opt.uio_iovcnt].iov_base = "host.hostname";
426 	optiov[opt.uio_iovcnt].iov_len = sizeof("host.hostname");
427 	opt.uio_iovcnt++;
428 	optiov[opt.uio_iovcnt].iov_base = u_hostname;
429 	error = copyinstr(j->hostname, u_hostname, MAXHOSTNAMELEN,
430 	    &optiov[opt.uio_iovcnt].iov_len);
431 	if (error) {
432 		free(u_path, M_TEMP);
433 		return (error);
434 	}
435 	opt.uio_iovcnt++;
436 	if (j->jailname != NULL) {
437 		optiov[opt.uio_iovcnt].iov_base = "name";
438 		optiov[opt.uio_iovcnt].iov_len = sizeof("name");
439 		opt.uio_iovcnt++;
440 		optiov[opt.uio_iovcnt].iov_base = u_name;
441 		error = copyinstr(j->jailname, u_name, MAXHOSTNAMELEN,
442 		    &optiov[opt.uio_iovcnt].iov_len);
443 		if (error) {
444 			free(u_path, M_TEMP);
445 			return (error);
446 		}
447 		opt.uio_iovcnt++;
448 	}
449 #ifdef INET
450 	optiov[opt.uio_iovcnt].iov_base = "ip4.addr";
451 	optiov[opt.uio_iovcnt].iov_len = sizeof("ip4.addr");
452 	opt.uio_iovcnt++;
453 	optiov[opt.uio_iovcnt].iov_base = u_ip4;
454 	optiov[opt.uio_iovcnt].iov_len = ip4s * sizeof(struct in_addr);
455 	if (j->version == 0)
456 		u_ip4->s_addr = j->ip4s;
457 	else {
458 		error = copyin(j->ip4, u_ip4, optiov[opt.uio_iovcnt].iov_len);
459 		if (error) {
460 			free(u_path, M_TEMP);
461 			return (error);
462 		}
463 	}
464 	opt.uio_iovcnt++;
465 #endif
466 #ifdef INET6
467 	optiov[opt.uio_iovcnt].iov_base = "ip6.addr";
468 	optiov[opt.uio_iovcnt].iov_len = sizeof("ip6.addr");
469 	opt.uio_iovcnt++;
470 	optiov[opt.uio_iovcnt].iov_base = u_ip6;
471 	optiov[opt.uio_iovcnt].iov_len = j->ip6s * sizeof(struct in6_addr);
472 	error = copyin(j->ip6, u_ip6, optiov[opt.uio_iovcnt].iov_len);
473 	if (error) {
474 		free(u_path, M_TEMP);
475 		return (error);
476 	}
477 	opt.uio_iovcnt++;
478 #endif
479 	KASSERT(opt.uio_iovcnt <= nitems(optiov),
480 		("kern_jail: too many iovecs (%d)", opt.uio_iovcnt));
481 	error = kern_jail_set(td, &opt, JAIL_CREATE | JAIL_ATTACH);
482 	free(u_path, M_TEMP);
483 	return (error);
484 }
485 
486 /*
487  * struct jail_set_args {
488  *	struct iovec *iovp;
489  *	unsigned int iovcnt;
490  *	int flags;
491  * };
492  */
493 int
494 sys_jail_set(struct thread *td, struct jail_set_args *uap)
495 {
496 	struct uio *auio;
497 	int error;
498 
499 	/* Check that we have an even number of iovecs. */
500 	if (uap->iovcnt & 1)
501 		return (EINVAL);
502 
503 	error = copyinuio(uap->iovp, uap->iovcnt, &auio);
504 	if (error)
505 		return (error);
506 	error = kern_jail_set(td, auio, uap->flags);
507 	free(auio, M_IOV);
508 	return (error);
509 }
510 
511 int
512 kern_jail_set(struct thread *td, struct uio *optuio, int flags)
513 {
514 	struct nameidata nd;
515 #ifdef INET
516 	struct in_addr *ip4;
517 #endif
518 #ifdef INET6
519 	struct in6_addr *ip6;
520 #endif
521 	struct vfsopt *opt;
522 	struct vfsoptlist *opts;
523 	struct prison *pr, *deadpr, *inspr, *mypr, *ppr, *tpr;
524 	struct vnode *root;
525 	char *domain, *errmsg, *host, *name, *namelc, *p, *path, *uuid;
526 	char *g_path, *osrelstr;
527 	struct bool_flags *bf;
528 	struct jailsys_flags *jsf;
529 #if defined(INET) || defined(INET6)
530 	struct prison *tppr;
531 	void *op;
532 #endif
533 	unsigned long hid;
534 	size_t namelen, onamelen, pnamelen;
535 	int born, created, cuflags, descend, drflags, enforce;
536 	int error, errmsg_len, errmsg_pos;
537 	int gotchildmax, gotenforce, gothid, gotrsnum, gotslevel;
538 	int jid, jsys, len, level;
539 	int childmax, osreldt, rsnum, slevel;
540 #if defined(INET) || defined(INET6)
541 	int ii, ij;
542 #endif
543 #ifdef INET
544 	int ip4s, redo_ip4;
545 #endif
546 #ifdef INET6
547 	int ip6s, redo_ip6;
548 #endif
549 	uint64_t pr_allow, ch_allow, pr_flags, ch_flags;
550 	uint64_t pr_allow_diff;
551 	unsigned tallow;
552 	char numbuf[12];
553 
554 	error = priv_check(td, PRIV_JAIL_SET);
555 	if (!error && (flags & JAIL_ATTACH))
556 		error = priv_check(td, PRIV_JAIL_ATTACH);
557 	if (error)
558 		return (error);
559 	mypr = td->td_ucred->cr_prison;
560 	if ((flags & JAIL_CREATE) && mypr->pr_childmax == 0)
561 		return (EPERM);
562 	if (flags & ~JAIL_SET_MASK)
563 		return (EINVAL);
564 
565 	/*
566 	 * Check all the parameters before committing to anything.  Not all
567 	 * errors can be caught early, but we may as well try.  Also, this
568 	 * takes care of some expensive stuff (path lookup) before getting
569 	 * the allprison lock.
570 	 *
571 	 * XXX Jails are not filesystems, and jail parameters are not mount
572 	 *     options.  But it makes more sense to re-use the vfsopt code
573 	 *     than duplicate it under a different name.
574 	 */
575 	error = vfs_buildopts(optuio, &opts);
576 	if (error)
577 		return (error);
578 #ifdef INET
579 	ip4 = NULL;
580 #endif
581 #ifdef INET6
582 	ip6 = NULL;
583 #endif
584 	g_path = NULL;
585 
586 	cuflags = flags & (JAIL_CREATE | JAIL_UPDATE);
587 	if (!cuflags) {
588 		error = EINVAL;
589 		vfs_opterror(opts, "no valid operation (create or update)");
590 		goto done_errmsg;
591 	}
592 
593 	error = vfs_copyopt(opts, "jid", &jid, sizeof(jid));
594 	if (error == ENOENT)
595 		jid = 0;
596 	else if (error != 0)
597 		goto done_free;
598 
599 	error = vfs_copyopt(opts, "securelevel", &slevel, sizeof(slevel));
600 	if (error == ENOENT)
601 		gotslevel = 0;
602 	else if (error != 0)
603 		goto done_free;
604 	else
605 		gotslevel = 1;
606 
607 	error =
608 	    vfs_copyopt(opts, "children.max", &childmax, sizeof(childmax));
609 	if (error == ENOENT)
610 		gotchildmax = 0;
611 	else if (error != 0)
612 		goto done_free;
613 	else
614 		gotchildmax = 1;
615 
616 	error = vfs_copyopt(opts, "enforce_statfs", &enforce, sizeof(enforce));
617 	if (error == ENOENT)
618 		gotenforce = 0;
619 	else if (error != 0)
620 		goto done_free;
621 	else if (enforce < 0 || enforce > 2) {
622 		error = EINVAL;
623 		goto done_free;
624 	} else
625 		gotenforce = 1;
626 
627 	error = vfs_copyopt(opts, "devfs_ruleset", &rsnum, sizeof(rsnum));
628 	if (error == ENOENT)
629 		gotrsnum = 0;
630 	else if (error != 0)
631 		goto done_free;
632 	else
633 		gotrsnum = 1;
634 
635 	pr_flags = ch_flags = 0;
636 	for (bf = pr_flag_bool;
637 	     bf < pr_flag_bool + nitems(pr_flag_bool);
638 	     bf++) {
639 		vfs_flagopt(opts, bf->name, &pr_flags, bf->flag);
640 		vfs_flagopt(opts, bf->noname, &ch_flags, bf->flag);
641 	}
642 	ch_flags |= pr_flags;
643 	for (jsf = pr_flag_jailsys;
644 	     jsf < pr_flag_jailsys + nitems(pr_flag_jailsys);
645 	     jsf++) {
646 		error = vfs_copyopt(opts, jsf->name, &jsys, sizeof(jsys));
647 		if (error == ENOENT)
648 			continue;
649 		if (error != 0)
650 			goto done_free;
651 		switch (jsys) {
652 		case JAIL_SYS_DISABLE:
653 			if (!jsf->disable) {
654 				error = EINVAL;
655 				goto done_free;
656 			}
657 			pr_flags |= jsf->disable;
658 			break;
659 		case JAIL_SYS_NEW:
660 			pr_flags |= jsf->new;
661 			break;
662 		case JAIL_SYS_INHERIT:
663 			break;
664 		default:
665 			error = EINVAL;
666 			goto done_free;
667 		}
668 		ch_flags |= jsf->new | jsf->disable;
669 	}
670 	if ((flags & (JAIL_CREATE | JAIL_ATTACH)) == JAIL_CREATE
671 	    && !(pr_flags & PR_PERSIST)) {
672 		error = EINVAL;
673 		vfs_opterror(opts, "new jail must persist or attach");
674 		goto done_errmsg;
675 	}
676 #ifdef VIMAGE
677 	if ((flags & JAIL_UPDATE) && (ch_flags & PR_VNET)) {
678 		error = EINVAL;
679 		vfs_opterror(opts, "vnet cannot be changed after creation");
680 		goto done_errmsg;
681 	}
682 #endif
683 #ifdef INET
684 	if ((flags & JAIL_UPDATE) && (ch_flags & PR_IP4_USER)) {
685 		error = EINVAL;
686 		vfs_opterror(opts, "ip4 cannot be changed after creation");
687 		goto done_errmsg;
688 	}
689 #endif
690 #ifdef INET6
691 	if ((flags & JAIL_UPDATE) && (ch_flags & PR_IP6_USER)) {
692 		error = EINVAL;
693 		vfs_opterror(opts, "ip6 cannot be changed after creation");
694 		goto done_errmsg;
695 	}
696 #endif
697 
698 	pr_allow = ch_allow = 0;
699 	for (bf = pr_flag_allow;
700 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
701 		atomic_load_int(&bf->flag) != 0;
702 	     bf++) {
703 		vfs_flagopt(opts, bf->name, &pr_allow, bf->flag);
704 		vfs_flagopt(opts, bf->noname, &ch_allow, bf->flag);
705 	}
706 	ch_allow |= pr_allow;
707 
708 	error = vfs_getopt(opts, "name", (void **)&name, &len);
709 	if (error == ENOENT)
710 		name = NULL;
711 	else if (error != 0)
712 		goto done_free;
713 	else {
714 		if (len == 0 || name[len - 1] != '\0') {
715 			error = EINVAL;
716 			goto done_free;
717 		}
718 		if (len > MAXHOSTNAMELEN) {
719 			error = ENAMETOOLONG;
720 			goto done_free;
721 		}
722 	}
723 
724 	error = vfs_getopt(opts, "host.hostname", (void **)&host, &len);
725 	if (error == ENOENT)
726 		host = NULL;
727 	else if (error != 0)
728 		goto done_free;
729 	else {
730 		ch_flags |= PR_HOST;
731 		pr_flags |= PR_HOST;
732 		if (len == 0 || host[len - 1] != '\0') {
733 			error = EINVAL;
734 			goto done_free;
735 		}
736 		if (len > MAXHOSTNAMELEN) {
737 			error = ENAMETOOLONG;
738 			goto done_free;
739 		}
740 	}
741 
742 	error = vfs_getopt(opts, "host.domainname", (void **)&domain, &len);
743 	if (error == ENOENT)
744 		domain = NULL;
745 	else if (error != 0)
746 		goto done_free;
747 	else {
748 		ch_flags |= PR_HOST;
749 		pr_flags |= PR_HOST;
750 		if (len == 0 || domain[len - 1] != '\0') {
751 			error = EINVAL;
752 			goto done_free;
753 		}
754 		if (len > MAXHOSTNAMELEN) {
755 			error = ENAMETOOLONG;
756 			goto done_free;
757 		}
758 	}
759 
760 	error = vfs_getopt(opts, "host.hostuuid", (void **)&uuid, &len);
761 	if (error == ENOENT)
762 		uuid = NULL;
763 	else if (error != 0)
764 		goto done_free;
765 	else {
766 		ch_flags |= PR_HOST;
767 		pr_flags |= PR_HOST;
768 		if (len == 0 || uuid[len - 1] != '\0') {
769 			error = EINVAL;
770 			goto done_free;
771 		}
772 		if (len > HOSTUUIDLEN) {
773 			error = ENAMETOOLONG;
774 			goto done_free;
775 		}
776 	}
777 
778 #ifdef COMPAT_FREEBSD32
779 	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
780 		uint32_t hid32;
781 
782 		error = vfs_copyopt(opts, "host.hostid", &hid32, sizeof(hid32));
783 		hid = hid32;
784 	} else
785 #endif
786 		error = vfs_copyopt(opts, "host.hostid", &hid, sizeof(hid));
787 	if (error == ENOENT)
788 		gothid = 0;
789 	else if (error != 0)
790 		goto done_free;
791 	else {
792 		gothid = 1;
793 		ch_flags |= PR_HOST;
794 		pr_flags |= PR_HOST;
795 	}
796 
797 #ifdef INET
798 	error = vfs_getopt(opts, "ip4.addr", &op, &ip4s);
799 	if (error == ENOENT)
800 		ip4s = 0;
801 	else if (error != 0)
802 		goto done_free;
803 	else if (ip4s & (sizeof(*ip4) - 1)) {
804 		error = EINVAL;
805 		goto done_free;
806 	} else {
807 		ch_flags |= PR_IP4_USER;
808 		pr_flags |= PR_IP4_USER;
809 		if (ip4s > 0) {
810 			ip4s /= sizeof(*ip4);
811 			if (ip4s > jail_max_af_ips) {
812 				error = EINVAL;
813 				vfs_opterror(opts, "too many IPv4 addresses");
814 				goto done_errmsg;
815 			}
816 			ip4 = malloc(ip4s * sizeof(*ip4), M_PRISON, M_WAITOK);
817 			bcopy(op, ip4, ip4s * sizeof(*ip4));
818 			/*
819 			 * IP addresses are all sorted but ip[0] to preserve
820 			 * the primary IP address as given from userland.
821 			 * This special IP is used for unbound outgoing
822 			 * connections as well for "loopback" traffic in case
823 			 * source address selection cannot find any more fitting
824 			 * address to connect from.
825 			 */
826 			if (ip4s > 1)
827 				qsort(ip4 + 1, ip4s - 1, sizeof(*ip4),
828 				    prison_qcmp_v4);
829 			/*
830 			 * Check for duplicate addresses and do some simple
831 			 * zero and broadcast checks. If users give other bogus
832 			 * addresses it is their problem.
833 			 *
834 			 * We do not have to care about byte order for these
835 			 * checks so we will do them in NBO.
836 			 */
837 			for (ii = 0; ii < ip4s; ii++) {
838 				if (ip4[ii].s_addr == INADDR_ANY ||
839 				    ip4[ii].s_addr == INADDR_BROADCAST) {
840 					error = EINVAL;
841 					goto done_free;
842 				}
843 				if ((ii+1) < ip4s &&
844 				    (ip4[0].s_addr == ip4[ii+1].s_addr ||
845 				     ip4[ii].s_addr == ip4[ii+1].s_addr)) {
846 					error = EINVAL;
847 					goto done_free;
848 				}
849 			}
850 		}
851 	}
852 #endif
853 
854 #ifdef INET6
855 	error = vfs_getopt(opts, "ip6.addr", &op, &ip6s);
856 	if (error == ENOENT)
857 		ip6s = 0;
858 	else if (error != 0)
859 		goto done_free;
860 	else if (ip6s & (sizeof(*ip6) - 1)) {
861 		error = EINVAL;
862 		goto done_free;
863 	} else {
864 		ch_flags |= PR_IP6_USER;
865 		pr_flags |= PR_IP6_USER;
866 		if (ip6s > 0) {
867 			ip6s /= sizeof(*ip6);
868 			if (ip6s > jail_max_af_ips) {
869 				error = EINVAL;
870 				vfs_opterror(opts, "too many IPv6 addresses");
871 				goto done_errmsg;
872 			}
873 			ip6 = malloc(ip6s * sizeof(*ip6), M_PRISON, M_WAITOK);
874 			bcopy(op, ip6, ip6s * sizeof(*ip6));
875 			if (ip6s > 1)
876 				qsort(ip6 + 1, ip6s - 1, sizeof(*ip6),
877 				    prison_qcmp_v6);
878 			for (ii = 0; ii < ip6s; ii++) {
879 				if (IN6_IS_ADDR_UNSPECIFIED(&ip6[ii])) {
880 					error = EINVAL;
881 					goto done_free;
882 				}
883 				if ((ii+1) < ip6s &&
884 				    (IN6_ARE_ADDR_EQUAL(&ip6[0], &ip6[ii+1]) ||
885 				     IN6_ARE_ADDR_EQUAL(&ip6[ii], &ip6[ii+1])))
886 				{
887 					error = EINVAL;
888 					goto done_free;
889 				}
890 			}
891 		}
892 	}
893 #endif
894 
895 #if defined(VIMAGE) && (defined(INET) || defined(INET6))
896 	if ((ch_flags & PR_VNET) && (ch_flags & (PR_IP4_USER | PR_IP6_USER))) {
897 		error = EINVAL;
898 		vfs_opterror(opts,
899 		    "vnet jails cannot have IP address restrictions");
900 		goto done_errmsg;
901 	}
902 #endif
903 
904 	error = vfs_getopt(opts, "osrelease", (void **)&osrelstr, &len);
905 	if (error == ENOENT)
906 		osrelstr = NULL;
907 	else if (error != 0)
908 		goto done_free;
909 	else {
910 		if (flags & JAIL_UPDATE) {
911 			error = EINVAL;
912 			vfs_opterror(opts,
913 			    "osrelease cannot be changed after creation");
914 			goto done_errmsg;
915 		}
916 		if (len == 0 || osrelstr[len - 1] != '\0') {
917 			error = EINVAL;
918 			goto done_free;
919 		}
920 		if (len >= OSRELEASELEN) {
921 			error = ENAMETOOLONG;
922 			vfs_opterror(opts,
923 			    "osrelease string must be 1-%d bytes long",
924 			    OSRELEASELEN - 1);
925 			goto done_errmsg;
926 		}
927 	}
928 
929 	error = vfs_copyopt(opts, "osreldate", &osreldt, sizeof(osreldt));
930 	if (error == ENOENT)
931 		osreldt = 0;
932 	else if (error != 0)
933 		goto done_free;
934 	else {
935 		if (flags & JAIL_UPDATE) {
936 			error = EINVAL;
937 			vfs_opterror(opts,
938 			    "osreldate cannot be changed after creation");
939 			goto done_errmsg;
940 		}
941 		if (osreldt == 0) {
942 			error = EINVAL;
943 			vfs_opterror(opts, "osreldate cannot be 0");
944 			goto done_errmsg;
945 		}
946 	}
947 
948 	root = NULL;
949 	error = vfs_getopt(opts, "path", (void **)&path, &len);
950 	if (error == ENOENT)
951 		path = NULL;
952 	else if (error != 0)
953 		goto done_free;
954 	else {
955 		if (flags & JAIL_UPDATE) {
956 			error = EINVAL;
957 			vfs_opterror(opts,
958 			    "path cannot be changed after creation");
959 			goto done_errmsg;
960 		}
961 		if (len == 0 || path[len - 1] != '\0') {
962 			error = EINVAL;
963 			goto done_free;
964 		}
965 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path);
966 		error = namei(&nd);
967 		if (error)
968 			goto done_free;
969 		root = nd.ni_vp;
970 		NDFREE(&nd, NDF_ONLY_PNBUF);
971 		g_path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
972 		strlcpy(g_path, path, MAXPATHLEN);
973 		error = vn_path_to_global_path(td, root, g_path, MAXPATHLEN);
974 		if (error == 0) {
975 			path = g_path;
976 		} else {
977 			/* exit on other errors */
978 			goto done_free;
979 		}
980 		if (root->v_type != VDIR) {
981 			error = ENOTDIR;
982 			vput(root);
983 			goto done_free;
984 		}
985 		VOP_UNLOCK(root);
986 	}
987 
988 	/*
989 	 * Find the specified jail, or at least its parent.
990 	 * This abuses the file error codes ENOENT and EEXIST.
991 	 */
992 	pr = NULL;
993 	inspr = NULL;
994 	if (cuflags == JAIL_CREATE && jid == 0 && name != NULL) {
995 		namelc = strrchr(name, '.');
996 		jid = strtoul(namelc != NULL ? namelc + 1 : name, &p, 10);
997 		if (*p != '\0')
998 			jid = 0;
999 	}
1000 	sx_xlock(&allprison_lock);
1001 	drflags = PD_LIST_XLOCKED;
1002 	ppr = mypr;
1003 	if (!prison_isalive(ppr)) {
1004 		/* This jail is dying.  This process will surely follow. */
1005 		error = EAGAIN;
1006 		goto done_deref;
1007 	}
1008 	if (jid != 0) {
1009 		if (jid < 0) {
1010 			error = EINVAL;
1011 			vfs_opterror(opts, "negative jid");
1012 			goto done_deref;
1013 		}
1014 		/*
1015 		 * See if a requested jid already exists.  Keep track of
1016 		 * where it can be inserted later.
1017 		 */
1018 		TAILQ_FOREACH(inspr, &allprison, pr_list) {
1019 			if (inspr->pr_id < jid)
1020 				continue;
1021 			if (inspr->pr_id > jid)
1022 				break;
1023 			pr = inspr;
1024 			mtx_lock(&pr->pr_mtx);
1025 			drflags |= PD_LOCKED;
1026 			inspr = NULL;
1027 			break;
1028 		}
1029 		if (pr != NULL) {
1030 			/* Create: jid must not exist. */
1031 			if (cuflags == JAIL_CREATE) {
1032 				/*
1033 				 * Even creators that cannot see the jail will
1034 				 * get EEXIST.
1035 				 */
1036 				error = EEXIST;
1037 				vfs_opterror(opts, "jail %d already exists",
1038 				    jid);
1039 				goto done_deref;
1040 			}
1041 			if (!prison_ischild(mypr, pr)) {
1042 				/*
1043 				 * Updaters get ENOENT if they cannot see the
1044 				 * jail.  This is true even for CREATE | UPDATE,
1045 				 * which normally cannot give this error.
1046 				 */
1047 				error = ENOENT;
1048 				vfs_opterror(opts, "jail %d not found", jid);
1049 				goto done_deref;
1050 			}
1051 			ppr = pr->pr_parent;
1052 			if (!prison_isalive(ppr)) {
1053 				error = ENOENT;
1054 				vfs_opterror(opts, "jail %d is dying",
1055 				    ppr->pr_id);
1056 				goto done_deref;
1057 			}
1058 			if (!prison_isalive(pr)) {
1059 				if (!(flags & JAIL_DYING)) {
1060 					error = ENOENT;
1061 					vfs_opterror(opts, "jail %d is dying",
1062 					    jid);
1063 					goto done_deref;
1064 				}
1065 				if ((flags & JAIL_ATTACH) ||
1066 				    (pr_flags & PR_PERSIST)) {
1067 					/*
1068 					 * A dying jail might be resurrected
1069 					 * (via attach or persist), but first
1070 					 * it must determine if another jail
1071 					 * has claimed its name.  Accomplish
1072 					 * this by implicitly re-setting the
1073 					 * name.
1074 					 */
1075 					if (name == NULL)
1076 						name = prison_name(mypr, pr);
1077 				}
1078 			}
1079 		} else {
1080 			/* Update: jid must exist. */
1081 			if (cuflags == JAIL_UPDATE) {
1082 				error = ENOENT;
1083 				vfs_opterror(opts, "jail %d not found", jid);
1084 				goto done_deref;
1085 			}
1086 		}
1087 	}
1088 	/*
1089 	 * If the caller provided a name, look for a jail by that name.
1090 	 * This has different semantics for creates and updates keyed by jid
1091 	 * (where the name must not already exist in a different jail),
1092 	 * and updates keyed by the name itself (where the name must exist
1093 	 * because that is the jail being updated).
1094 	 */
1095 	namelc = NULL;
1096 	if (name != NULL) {
1097 		namelc = strrchr(name, '.');
1098 		if (namelc == NULL)
1099 			namelc = name;
1100 		else {
1101 			/*
1102 			 * This is a hierarchical name.  Split it into the
1103 			 * parent and child names, and make sure the parent
1104 			 * exists or matches an already found jail.
1105 			 */
1106 			if (pr != NULL) {
1107 				if (strncmp(name, ppr->pr_name, namelc - name)
1108 				    || ppr->pr_name[namelc - name] != '\0') {
1109 					error = EINVAL;
1110 					vfs_opterror(opts,
1111 					    "cannot change jail's parent");
1112 					goto done_deref;
1113 				}
1114 			} else {
1115 				*namelc = '\0';
1116 				ppr = prison_find_name(mypr, name);
1117 				if (ppr == NULL) {
1118 					error = ENOENT;
1119 					vfs_opterror(opts,
1120 					    "jail \"%s\" not found", name);
1121 					goto done_deref;
1122 				}
1123 				mtx_unlock(&ppr->pr_mtx);
1124 				if (!prison_isalive(ppr)) {
1125 					error = ENOENT;
1126 					vfs_opterror(opts,
1127 					    "jail \"%s\" is dying", name);
1128 					goto done_deref;
1129 				}
1130 				*namelc = '.';
1131 			}
1132 			namelc++;
1133 		}
1134 		if (namelc[0] != '\0') {
1135 			pnamelen =
1136 			    (ppr == &prison0) ? 0 : strlen(ppr->pr_name) + 1;
1137 			deadpr = NULL;
1138 			FOREACH_PRISON_CHILD(ppr, tpr) {
1139 				if (tpr != pr &&
1140 				    !strcmp(tpr->pr_name + pnamelen, namelc)) {
1141 					if (prison_isalive(tpr)) {
1142 						if (pr == NULL &&
1143 						    cuflags != JAIL_CREATE) {
1144 							/*
1145 							 * Use this jail
1146 							 * for updates.
1147 							 */
1148 							pr = tpr;
1149 							mtx_lock(&pr->pr_mtx);
1150 							drflags |= PD_LOCKED;
1151 							break;
1152 						}
1153 						/*
1154 						 * Create, or update(jid):
1155 						 * name must not exist in an
1156 						 * active sibling jail.
1157 						 */
1158 						error = EEXIST;
1159 						vfs_opterror(opts,
1160 						   "jail \"%s\" already exists",
1161 						   name);
1162 						goto done_deref;
1163 					}
1164 					if (pr == NULL &&
1165 					    cuflags != JAIL_CREATE) {
1166 						deadpr = tpr;
1167 					}
1168 				}
1169 			}
1170 			/* If no active jail is found, use a dying one. */
1171 			if (deadpr != NULL && pr == NULL) {
1172 				if (flags & JAIL_DYING) {
1173 					pr = deadpr;
1174 					mtx_lock(&pr->pr_mtx);
1175 					drflags |= PD_LOCKED;
1176 				} else if (cuflags == JAIL_UPDATE) {
1177 					error = ENOENT;
1178 					vfs_opterror(opts,
1179 					    "jail \"%s\" is dying", name);
1180 					goto done_deref;
1181 				}
1182 			}
1183 			/* Update: name must exist if no jid. */
1184 			else if (cuflags == JAIL_UPDATE && pr == NULL) {
1185 				error = ENOENT;
1186 				vfs_opterror(opts, "jail \"%s\" not found",
1187 				    name);
1188 				goto done_deref;
1189 			}
1190 		}
1191 	}
1192 	/* Update: must provide a jid or name. */
1193 	else if (cuflags == JAIL_UPDATE && pr == NULL) {
1194 		error = ENOENT;
1195 		vfs_opterror(opts, "update specified no jail");
1196 		goto done_deref;
1197 	}
1198 
1199 	/* If there's no prison to update, create a new one and link it in. */
1200 	created = pr == NULL;
1201 	if (created) {
1202 		for (tpr = mypr; tpr != NULL; tpr = tpr->pr_parent)
1203 			if (tpr->pr_childcount >= tpr->pr_childmax) {
1204 				error = EPERM;
1205 				vfs_opterror(opts, "prison limit exceeded");
1206 				goto done_deref;
1207 			}
1208 		if (jid == 0 && (jid = get_next_prid(&inspr)) == 0) {
1209 			error = EAGAIN;
1210 			vfs_opterror(opts, "no available jail IDs");
1211 			goto done_deref;
1212 		}
1213 
1214 		pr = malloc(sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO);
1215 		pr->pr_state = PRISON_STATE_INVALID;
1216 		refcount_init(&pr->pr_ref, 1);
1217 		refcount_init(&pr->pr_uref, 0);
1218 		drflags |= PD_DEREF;
1219 		LIST_INIT(&pr->pr_children);
1220 		mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF | MTX_DUPOK);
1221 		TASK_INIT(&pr->pr_task, 0, prison_complete, pr);
1222 
1223 		pr->pr_id = jid;
1224 		if (inspr != NULL)
1225 			TAILQ_INSERT_BEFORE(inspr, pr, pr_list);
1226 		else
1227 			TAILQ_INSERT_TAIL(&allprison, pr, pr_list);
1228 
1229 		pr->pr_parent = ppr;
1230 		prison_hold(ppr);
1231 		prison_proc_hold(ppr);
1232 		LIST_INSERT_HEAD(&ppr->pr_children, pr, pr_sibling);
1233 		for (tpr = ppr; tpr != NULL; tpr = tpr->pr_parent)
1234 			tpr->pr_childcount++;
1235 
1236 		/* Set some default values, and inherit some from the parent. */
1237 		if (namelc == NULL)
1238 			namelc = "";
1239 		if (path == NULL) {
1240 			path = "/";
1241 			root = mypr->pr_root;
1242 			vref(root);
1243 		}
1244 		strlcpy(pr->pr_hostuuid, DEFAULT_HOSTUUID, HOSTUUIDLEN);
1245 		pr->pr_flags |= PR_HOST;
1246 #if defined(INET) || defined(INET6)
1247 #ifdef VIMAGE
1248 		if (!(pr_flags & PR_VNET))
1249 #endif
1250 		{
1251 #ifdef INET
1252 			if (!(ch_flags & PR_IP4_USER))
1253 				pr->pr_flags |= PR_IP4 | PR_IP4_USER;
1254 			else if (!(pr_flags & PR_IP4_USER)) {
1255 				pr->pr_flags |= ppr->pr_flags & PR_IP4;
1256 				if (ppr->pr_ip4 != NULL) {
1257 					pr->pr_ip4s = ppr->pr_ip4s;
1258 					pr->pr_ip4 = malloc(pr->pr_ip4s *
1259 					    sizeof(struct in_addr), M_PRISON,
1260 					    M_WAITOK);
1261 					bcopy(ppr->pr_ip4, pr->pr_ip4,
1262 					    pr->pr_ip4s * sizeof(*pr->pr_ip4));
1263 				}
1264 			}
1265 #endif
1266 #ifdef INET6
1267 			if (!(ch_flags & PR_IP6_USER))
1268 				pr->pr_flags |= PR_IP6 | PR_IP6_USER;
1269 			else if (!(pr_flags & PR_IP6_USER)) {
1270 				pr->pr_flags |= ppr->pr_flags & PR_IP6;
1271 				if (ppr->pr_ip6 != NULL) {
1272 					pr->pr_ip6s = ppr->pr_ip6s;
1273 					pr->pr_ip6 = malloc(pr->pr_ip6s *
1274 					    sizeof(struct in6_addr), M_PRISON,
1275 					    M_WAITOK);
1276 					bcopy(ppr->pr_ip6, pr->pr_ip6,
1277 					    pr->pr_ip6s * sizeof(*pr->pr_ip6));
1278 				}
1279 			}
1280 #endif
1281 		}
1282 #endif
1283 		/* Source address selection is always on by default. */
1284 		pr->pr_flags |= _PR_IP_SADDRSEL;
1285 
1286 		pr->pr_securelevel = ppr->pr_securelevel;
1287 		pr->pr_allow = JAIL_DEFAULT_ALLOW & ppr->pr_allow;
1288 		pr->pr_enforce_statfs = jail_default_enforce_statfs;
1289 		pr->pr_devfs_rsnum = ppr->pr_devfs_rsnum;
1290 
1291 		pr->pr_osreldate = osreldt ? osreldt : ppr->pr_osreldate;
1292 		if (osrelstr == NULL)
1293 			strlcpy(pr->pr_osrelease, ppr->pr_osrelease,
1294 			    sizeof(pr->pr_osrelease));
1295 		else
1296 			strlcpy(pr->pr_osrelease, osrelstr,
1297 			    sizeof(pr->pr_osrelease));
1298 
1299 #ifdef VIMAGE
1300 		/* Allocate a new vnet if specified. */
1301 		pr->pr_vnet = (pr_flags & PR_VNET)
1302 		    ? vnet_alloc() : ppr->pr_vnet;
1303 #endif
1304 		/*
1305 		 * Allocate a dedicated cpuset for each jail.
1306 		 * Unlike other initial settings, this may return an error.
1307 		 */
1308 		error = cpuset_create_root(ppr, &pr->pr_cpuset);
1309 		if (error)
1310 			goto done_deref;
1311 
1312 		mtx_lock(&pr->pr_mtx);
1313 		drflags |= PD_LOCKED;
1314 	} else {
1315 		/*
1316 		 * Grab a reference for existing prisons, to ensure they
1317 		 * continue to exist for the duration of the call.
1318 		 */
1319 		prison_hold(pr);
1320 		drflags |= PD_DEREF;
1321 #if defined(VIMAGE) && (defined(INET) || defined(INET6))
1322 		if ((pr->pr_flags & PR_VNET) &&
1323 		    (ch_flags & (PR_IP4_USER | PR_IP6_USER))) {
1324 			error = EINVAL;
1325 			vfs_opterror(opts,
1326 			    "vnet jails cannot have IP address restrictions");
1327 			goto done_deref;
1328 		}
1329 #endif
1330 #ifdef INET
1331 		if (PR_IP4_USER & ch_flags & (pr_flags ^ pr->pr_flags)) {
1332 			error = EINVAL;
1333 			vfs_opterror(opts,
1334 			    "ip4 cannot be changed after creation");
1335 			goto done_deref;
1336 		}
1337 #endif
1338 #ifdef INET6
1339 		if (PR_IP6_USER & ch_flags & (pr_flags ^ pr->pr_flags)) {
1340 			error = EINVAL;
1341 			vfs_opterror(opts,
1342 			    "ip6 cannot be changed after creation");
1343 			goto done_deref;
1344 		}
1345 #endif
1346 	}
1347 
1348 	/* Do final error checking before setting anything. */
1349 	if (gotslevel) {
1350 		if (slevel < ppr->pr_securelevel) {
1351 			error = EPERM;
1352 			goto done_deref;
1353 		}
1354 	}
1355 	if (gotchildmax) {
1356 		if (childmax >= ppr->pr_childmax) {
1357 			error = EPERM;
1358 			goto done_deref;
1359 		}
1360 	}
1361 	if (gotenforce) {
1362 		if (enforce < ppr->pr_enforce_statfs) {
1363 			error = EPERM;
1364 			goto done_deref;
1365 		}
1366 	}
1367 	if (gotrsnum) {
1368 		/*
1369 		 * devfs_rsnum is a uint16_t
1370 		 */
1371 		if (rsnum < 0 || rsnum > 65535) {
1372 			error = EINVAL;
1373 			goto done_deref;
1374 		}
1375 		/*
1376 		 * Nested jails always inherit parent's devfs ruleset
1377 		 */
1378 		if (jailed(td->td_ucred)) {
1379 			if (rsnum > 0 && rsnum != ppr->pr_devfs_rsnum) {
1380 				error = EPERM;
1381 				goto done_deref;
1382 			} else
1383 				rsnum = ppr->pr_devfs_rsnum;
1384 		}
1385 	}
1386 #ifdef INET
1387 	if (ip4s > 0) {
1388 		if (ppr->pr_flags & PR_IP4) {
1389 			/*
1390 			 * Make sure the new set of IP addresses is a
1391 			 * subset of the parent's list.  Don't worry
1392 			 * about the parent being unlocked, as any
1393 			 * setting is done with allprison_lock held.
1394 			 */
1395 			for (ij = 0; ij < ppr->pr_ip4s; ij++)
1396 				if (ip4[0].s_addr == ppr->pr_ip4[ij].s_addr)
1397 					break;
1398 			if (ij == ppr->pr_ip4s) {
1399 				error = EPERM;
1400 				goto done_deref;
1401 			}
1402 			if (ip4s > 1) {
1403 				for (ii = ij = 1; ii < ip4s; ii++) {
1404 					if (ip4[ii].s_addr ==
1405 					    ppr->pr_ip4[0].s_addr)
1406 						continue;
1407 					for (; ij < ppr->pr_ip4s; ij++)
1408 						if (ip4[ii].s_addr ==
1409 						    ppr->pr_ip4[ij].s_addr)
1410 							break;
1411 					if (ij == ppr->pr_ip4s)
1412 						break;
1413 				}
1414 				if (ij == ppr->pr_ip4s) {
1415 					error = EPERM;
1416 					goto done_deref;
1417 				}
1418 			}
1419 		}
1420 		/*
1421 		 * Check for conflicting IP addresses.  We permit them
1422 		 * if there is no more than one IP on each jail.  If
1423 		 * there is a duplicate on a jail with more than one
1424 		 * IP stop checking and return error.
1425 		 */
1426 #ifdef VIMAGE
1427 		for (tppr = ppr; tppr != &prison0; tppr = tppr->pr_parent)
1428 			if (tppr->pr_flags & PR_VNET)
1429 				break;
1430 #else
1431 		tppr = &prison0;
1432 #endif
1433 		FOREACH_PRISON_DESCENDANT(tppr, tpr, descend) {
1434 			if (tpr == pr ||
1435 #ifdef VIMAGE
1436 			    (tpr != tppr && (tpr->pr_flags & PR_VNET)) ||
1437 #endif
1438 			    !prison_isalive(tpr)) {
1439 				descend = 0;
1440 				continue;
1441 			}
1442 			if (!(tpr->pr_flags & PR_IP4_USER))
1443 				continue;
1444 			descend = 0;
1445 			if (tpr->pr_ip4 == NULL ||
1446 			    (ip4s == 1 && tpr->pr_ip4s == 1))
1447 				continue;
1448 			for (ii = 0; ii < ip4s; ii++) {
1449 				if (prison_check_ip4_locked(tpr, &ip4[ii]) ==
1450 				    0) {
1451 					error = EADDRINUSE;
1452 					vfs_opterror(opts,
1453 					    "IPv4 addresses clash");
1454 					goto done_deref;
1455 				}
1456 			}
1457 		}
1458 	}
1459 #endif
1460 #ifdef INET6
1461 	if (ip6s > 0) {
1462 		if (ppr->pr_flags & PR_IP6) {
1463 			/*
1464 			 * Make sure the new set of IP addresses is a
1465 			 * subset of the parent's list.
1466 			 */
1467 			for (ij = 0; ij < ppr->pr_ip6s; ij++)
1468 				if (IN6_ARE_ADDR_EQUAL(&ip6[0],
1469 				    &ppr->pr_ip6[ij]))
1470 					break;
1471 			if (ij == ppr->pr_ip6s) {
1472 				error = EPERM;
1473 				goto done_deref;
1474 			}
1475 			if (ip6s > 1) {
1476 				for (ii = ij = 1; ii < ip6s; ii++) {
1477 					if (IN6_ARE_ADDR_EQUAL(&ip6[ii],
1478 					     &ppr->pr_ip6[0]))
1479 						continue;
1480 					for (; ij < ppr->pr_ip6s; ij++)
1481 						if (IN6_ARE_ADDR_EQUAL(
1482 						    &ip6[ii], &ppr->pr_ip6[ij]))
1483 							break;
1484 					if (ij == ppr->pr_ip6s)
1485 						break;
1486 				}
1487 				if (ij == ppr->pr_ip6s) {
1488 					error = EPERM;
1489 					goto done_deref;
1490 				}
1491 			}
1492 		}
1493 		/* Check for conflicting IP addresses. */
1494 #ifdef VIMAGE
1495 		for (tppr = ppr; tppr != &prison0; tppr = tppr->pr_parent)
1496 			if (tppr->pr_flags & PR_VNET)
1497 				break;
1498 #else
1499 		tppr = &prison0;
1500 #endif
1501 		FOREACH_PRISON_DESCENDANT(tppr, tpr, descend) {
1502 			if (tpr == pr ||
1503 #ifdef VIMAGE
1504 			    (tpr != tppr && (tpr->pr_flags & PR_VNET)) ||
1505 #endif
1506 			    !prison_isalive(tpr)) {
1507 				descend = 0;
1508 				continue;
1509 			}
1510 			if (!(tpr->pr_flags & PR_IP6_USER))
1511 				continue;
1512 			descend = 0;
1513 			if (tpr->pr_ip6 == NULL ||
1514 			    (ip6s == 1 && tpr->pr_ip6s == 1))
1515 				continue;
1516 			for (ii = 0; ii < ip6s; ii++) {
1517 				if (prison_check_ip6_locked(tpr, &ip6[ii]) ==
1518 				    0) {
1519 					error = EADDRINUSE;
1520 					vfs_opterror(opts,
1521 					    "IPv6 addresses clash");
1522 					goto done_deref;
1523 				}
1524 			}
1525 		}
1526 	}
1527 #endif
1528 	onamelen = namelen = 0;
1529 	if (namelc != NULL) {
1530 		/* Give a default name of the jid.  Also allow the name to be
1531 		 * explicitly the jid - but not any other number, and only in
1532 		 * normal form (no leading zero/etc).
1533 		 */
1534 		if (namelc[0] == '\0')
1535 			snprintf(namelc = numbuf, sizeof(numbuf), "%d", jid);
1536 		else if ((strtoul(namelc, &p, 10) != jid ||
1537 			  namelc[0] < '1' || namelc[0] > '9') && *p == '\0') {
1538 			error = EINVAL;
1539 			vfs_opterror(opts,
1540 			    "name cannot be numeric (unless it is the jid)");
1541 			goto done_deref;
1542 		}
1543 		/*
1544 		 * Make sure the name isn't too long for the prison or its
1545 		 * children.
1546 		 */
1547 		pnamelen = (ppr == &prison0) ? 0 : strlen(ppr->pr_name) + 1;
1548 		onamelen = strlen(pr->pr_name + pnamelen);
1549 		namelen = strlen(namelc);
1550 		if (pnamelen + namelen + 1 > sizeof(pr->pr_name)) {
1551 			error = ENAMETOOLONG;
1552 			goto done_deref;
1553 		}
1554 		FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1555 			if (strlen(tpr->pr_name) + (namelen - onamelen) >=
1556 			    sizeof(pr->pr_name)) {
1557 				error = ENAMETOOLONG;
1558 				goto done_deref;
1559 			}
1560 		}
1561 	}
1562 	pr_allow_diff = pr_allow & ~ppr->pr_allow;
1563 	if (pr_allow_diff & ~PR_ALLOW_DIFFERENCES) {
1564 		error = EPERM;
1565 		goto done_deref;
1566 	}
1567 
1568 	/*
1569 	 * Let modules check their parameters.  This requires unlocking and
1570 	 * then re-locking the prison, but this is still a valid state as long
1571 	 * as allprison_lock remains xlocked.
1572 	 */
1573 	mtx_unlock(&pr->pr_mtx);
1574 	drflags &= ~PD_LOCKED;
1575 	error = osd_jail_call(pr, PR_METHOD_CHECK, opts);
1576 	if (error != 0)
1577 		goto done_deref;
1578 	mtx_lock(&pr->pr_mtx);
1579 	drflags |= PD_LOCKED;
1580 
1581 	/* At this point, all valid parameters should have been noted. */
1582 	TAILQ_FOREACH(opt, opts, link) {
1583 		if (!opt->seen && strcmp(opt->name, "errmsg")) {
1584 			error = EINVAL;
1585 			vfs_opterror(opts, "unknown parameter: %s", opt->name);
1586 			goto done_deref;
1587 		}
1588 	}
1589 
1590 	/* Set the parameters of the prison. */
1591 #ifdef INET
1592 	redo_ip4 = 0;
1593 	if (pr_flags & PR_IP4_USER) {
1594 		pr->pr_flags |= PR_IP4;
1595 		free(pr->pr_ip4, M_PRISON);
1596 		pr->pr_ip4s = ip4s;
1597 		pr->pr_ip4 = ip4;
1598 		ip4 = NULL;
1599 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1600 #ifdef VIMAGE
1601 			if (tpr->pr_flags & PR_VNET) {
1602 				descend = 0;
1603 				continue;
1604 			}
1605 #endif
1606 			if (prison_restrict_ip4(tpr, NULL)) {
1607 				redo_ip4 = 1;
1608 				descend = 0;
1609 			}
1610 		}
1611 	}
1612 #endif
1613 #ifdef INET6
1614 	redo_ip6 = 0;
1615 	if (pr_flags & PR_IP6_USER) {
1616 		pr->pr_flags |= PR_IP6;
1617 		free(pr->pr_ip6, M_PRISON);
1618 		pr->pr_ip6s = ip6s;
1619 		pr->pr_ip6 = ip6;
1620 		ip6 = NULL;
1621 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1622 #ifdef VIMAGE
1623 			if (tpr->pr_flags & PR_VNET) {
1624 				descend = 0;
1625 				continue;
1626 			}
1627 #endif
1628 			if (prison_restrict_ip6(tpr, NULL)) {
1629 				redo_ip6 = 1;
1630 				descend = 0;
1631 			}
1632 		}
1633 	}
1634 #endif
1635 	if (gotslevel) {
1636 		pr->pr_securelevel = slevel;
1637 		/* Set all child jails to be at least this level. */
1638 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1639 			if (tpr->pr_securelevel < slevel)
1640 				tpr->pr_securelevel = slevel;
1641 	}
1642 	if (gotchildmax) {
1643 		pr->pr_childmax = childmax;
1644 		/* Set all child jails to under this limit. */
1645 		FOREACH_PRISON_DESCENDANT_LOCKED_LEVEL(pr, tpr, descend, level)
1646 			if (tpr->pr_childmax > childmax - level)
1647 				tpr->pr_childmax = childmax > level
1648 				    ? childmax - level : 0;
1649 	}
1650 	if (gotenforce) {
1651 		pr->pr_enforce_statfs = enforce;
1652 		/* Pass this restriction on to the children. */
1653 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1654 			if (tpr->pr_enforce_statfs < enforce)
1655 				tpr->pr_enforce_statfs = enforce;
1656 	}
1657 	if (gotrsnum) {
1658 		pr->pr_devfs_rsnum = rsnum;
1659 		/* Pass this restriction on to the children. */
1660 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1661 			tpr->pr_devfs_rsnum = rsnum;
1662 	}
1663 	if (namelc != NULL) {
1664 		if (ppr == &prison0)
1665 			strlcpy(pr->pr_name, namelc, sizeof(pr->pr_name));
1666 		else
1667 			snprintf(pr->pr_name, sizeof(pr->pr_name), "%s.%s",
1668 			    ppr->pr_name, namelc);
1669 		/* Change this component of child names. */
1670 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1671 			bcopy(tpr->pr_name + onamelen, tpr->pr_name + namelen,
1672 			    strlen(tpr->pr_name + onamelen) + 1);
1673 			bcopy(pr->pr_name, tpr->pr_name, namelen);
1674 		}
1675 	}
1676 	if (path != NULL) {
1677 		/* Try to keep a real-rooted full pathname. */
1678 		strlcpy(pr->pr_path, path, sizeof(pr->pr_path));
1679 		pr->pr_root = root;
1680 		root = NULL;
1681 	}
1682 	if (PR_HOST & ch_flags & ~pr_flags) {
1683 		if (pr->pr_flags & PR_HOST) {
1684 			/*
1685 			 * Copy the parent's host info.  As with pr_ip4 above,
1686 			 * the lack of a lock on the parent is not a problem;
1687 			 * it is always set with allprison_lock at least
1688 			 * shared, and is held exclusively here.
1689 			 */
1690 			strlcpy(pr->pr_hostname, pr->pr_parent->pr_hostname,
1691 			    sizeof(pr->pr_hostname));
1692 			strlcpy(pr->pr_domainname, pr->pr_parent->pr_domainname,
1693 			    sizeof(pr->pr_domainname));
1694 			strlcpy(pr->pr_hostuuid, pr->pr_parent->pr_hostuuid,
1695 			    sizeof(pr->pr_hostuuid));
1696 			pr->pr_hostid = pr->pr_parent->pr_hostid;
1697 		}
1698 	} else if (host != NULL || domain != NULL || uuid != NULL || gothid) {
1699 		/* Set this prison, and any descendants without PR_HOST. */
1700 		if (host != NULL)
1701 			strlcpy(pr->pr_hostname, host, sizeof(pr->pr_hostname));
1702 		if (domain != NULL)
1703 			strlcpy(pr->pr_domainname, domain,
1704 			    sizeof(pr->pr_domainname));
1705 		if (uuid != NULL)
1706 			strlcpy(pr->pr_hostuuid, uuid, sizeof(pr->pr_hostuuid));
1707 		if (gothid)
1708 			pr->pr_hostid = hid;
1709 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1710 			if (tpr->pr_flags & PR_HOST)
1711 				descend = 0;
1712 			else {
1713 				if (host != NULL)
1714 					strlcpy(tpr->pr_hostname,
1715 					    pr->pr_hostname,
1716 					    sizeof(tpr->pr_hostname));
1717 				if (domain != NULL)
1718 					strlcpy(tpr->pr_domainname,
1719 					    pr->pr_domainname,
1720 					    sizeof(tpr->pr_domainname));
1721 				if (uuid != NULL)
1722 					strlcpy(tpr->pr_hostuuid,
1723 					    pr->pr_hostuuid,
1724 					    sizeof(tpr->pr_hostuuid));
1725 				if (gothid)
1726 					tpr->pr_hostid = hid;
1727 			}
1728 		}
1729 	}
1730 	pr->pr_allow = (pr->pr_allow & ~ch_allow) | pr_allow;
1731 	if ((tallow = ch_allow & ~pr_allow))
1732 		prison_set_allow_locked(pr, tallow, 0);
1733 	/*
1734 	 * Persistent prisons get an extra reference, and prisons losing their
1735 	 * persist flag lose that reference.
1736 	 */
1737 	born = !prison_isalive(pr);
1738 	if (ch_flags & PR_PERSIST & (pr_flags ^ pr->pr_flags)) {
1739 		if (pr_flags & PR_PERSIST) {
1740 			prison_hold(pr);
1741 			/*
1742 			 * This may make a dead prison alive again, but wait
1743 			 * to label it as such until after OSD calls have had
1744 			 * a chance to run (and perhaps to fail).
1745 			 */
1746 			refcount_acquire(&pr->pr_uref);
1747 		} else {
1748 			drflags |= PD_DEUREF;
1749 			prison_free_not_last(pr);
1750 		}
1751 	}
1752 	pr->pr_flags = (pr->pr_flags & ~ch_flags) | pr_flags;
1753 	mtx_unlock(&pr->pr_mtx);
1754 	drflags &= ~PD_LOCKED;
1755 	/*
1756 	 * Any errors past this point will need to de-persist newly created
1757 	 * prisons, as well as call remove methods.
1758 	 */
1759 	if (born)
1760 		drflags |= PD_KILL;
1761 
1762 #ifdef RACCT
1763 	if (racct_enable && created)
1764 		prison_racct_attach(pr);
1765 #endif
1766 
1767 	/* Locks may have prevented a complete restriction of child IP
1768 	 * addresses.  If so, allocate some more memory and try again.
1769 	 */
1770 #ifdef INET
1771 	while (redo_ip4) {
1772 		ip4s = pr->pr_ip4s;
1773 		ip4 = malloc(ip4s * sizeof(*ip4), M_PRISON, M_WAITOK);
1774 		mtx_lock(&pr->pr_mtx);
1775 		redo_ip4 = 0;
1776 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1777 #ifdef VIMAGE
1778 			if (tpr->pr_flags & PR_VNET) {
1779 				descend = 0;
1780 				continue;
1781 			}
1782 #endif
1783 			if (prison_restrict_ip4(tpr, ip4)) {
1784 				if (ip4 != NULL)
1785 					ip4 = NULL;
1786 				else
1787 					redo_ip4 = 1;
1788 			}
1789 		}
1790 		mtx_unlock(&pr->pr_mtx);
1791 	}
1792 #endif
1793 #ifdef INET6
1794 	while (redo_ip6) {
1795 		ip6s = pr->pr_ip6s;
1796 		ip6 = malloc(ip6s * sizeof(*ip6), M_PRISON, M_WAITOK);
1797 		mtx_lock(&pr->pr_mtx);
1798 		redo_ip6 = 0;
1799 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1800 #ifdef VIMAGE
1801 			if (tpr->pr_flags & PR_VNET) {
1802 				descend = 0;
1803 				continue;
1804 			}
1805 #endif
1806 			if (prison_restrict_ip6(tpr, ip6)) {
1807 				if (ip6 != NULL)
1808 					ip6 = NULL;
1809 				else
1810 					redo_ip6 = 1;
1811 			}
1812 		}
1813 		mtx_unlock(&pr->pr_mtx);
1814 	}
1815 #endif
1816 
1817 	/* Let the modules do their work. */
1818 	if (born) {
1819 		error = osd_jail_call(pr, PR_METHOD_CREATE, opts);
1820 		if (error)
1821 			goto done_deref;
1822 	}
1823 	error = osd_jail_call(pr, PR_METHOD_SET, opts);
1824 	if (error)
1825 		goto done_deref;
1826 
1827 	/*
1828 	 * A new prison is now ready to be seen; either it has gained a user
1829 	 * reference via persistence, or is about to gain one via attachment.
1830 	 */
1831 	if (born) {
1832 		drflags = prison_lock_xlock(pr, drflags);
1833 		pr->pr_state = PRISON_STATE_ALIVE;
1834 	}
1835 
1836 	/* Attach this process to the prison if requested. */
1837 	if (flags & JAIL_ATTACH) {
1838 		error = do_jail_attach(td, pr,
1839 		    prison_lock_xlock(pr, drflags & PD_LOCK_FLAGS));
1840 		drflags &= ~(PD_LOCKED | PD_LIST_XLOCKED);
1841 		if (error) {
1842 			vfs_opterror(opts, "attach failed");
1843 			goto done_deref;
1844 		}
1845 	}
1846 
1847 #ifdef RACCT
1848 	if (racct_enable && !created) {
1849 		if (drflags & PD_LOCKED) {
1850 			mtx_unlock(&pr->pr_mtx);
1851 			drflags &= ~PD_LOCKED;
1852 		}
1853 		if (drflags & PD_LIST_XLOCKED) {
1854 			sx_xunlock(&allprison_lock);
1855 			drflags &= ~PD_LIST_XLOCKED;
1856 		}
1857 		prison_racct_modify(pr);
1858 	}
1859 #endif
1860 
1861 	drflags &= ~PD_KILL;
1862 	td->td_retval[0] = pr->pr_id;
1863 
1864  done_deref:
1865 	/* Release any temporary prison holds and/or locks. */
1866 	if (pr != NULL)
1867 		prison_deref(pr, drflags);
1868 	else if (drflags & PD_LIST_SLOCKED)
1869 		sx_sunlock(&allprison_lock);
1870 	else if (drflags & PD_LIST_XLOCKED)
1871 		sx_xunlock(&allprison_lock);
1872 	if (root != NULL)
1873 		vrele(root);
1874  done_errmsg:
1875 	if (error) {
1876 		/* Write the error message back to userspace. */
1877 		if (vfs_getopt(opts, "errmsg", (void **)&errmsg,
1878 		    &errmsg_len) == 0 && errmsg_len > 0) {
1879 			errmsg_pos = 2 * vfs_getopt_pos(opts, "errmsg") + 1;
1880 			if (optuio->uio_segflg == UIO_SYSSPACE)
1881 				bcopy(errmsg,
1882 				    optuio->uio_iov[errmsg_pos].iov_base,
1883 				    errmsg_len);
1884 			else
1885 				copyout(errmsg,
1886 				    optuio->uio_iov[errmsg_pos].iov_base,
1887 				    errmsg_len);
1888 		}
1889 	}
1890  done_free:
1891 #ifdef INET
1892 	free(ip4, M_PRISON);
1893 #endif
1894 #ifdef INET6
1895 	free(ip6, M_PRISON);
1896 #endif
1897 	if (g_path != NULL)
1898 		free(g_path, M_TEMP);
1899 	vfs_freeopts(opts);
1900 	return (error);
1901 }
1902 
1903 /*
1904  * Find the next available prison ID.  Return the ID on success, or zero
1905  * on failure.  Also set a pointer to the allprison list entry the prison
1906  * should be inserted before.
1907  */
1908 static int
1909 get_next_prid(struct prison **insprp)
1910 {
1911 	struct prison *inspr;
1912 	int jid, maxid;
1913 
1914 	jid = lastprid % JAIL_MAX + 1;
1915 	if (TAILQ_EMPTY(&allprison) ||
1916 	    TAILQ_LAST(&allprison, prisonlist)->pr_id < jid) {
1917 		/*
1918 		 * A common case is for all jails to be implicitly numbered,
1919 		 * which means they'll go on the end of the list, at least
1920 		 * for the first JAIL_MAX times.
1921 		 */
1922 		inspr = NULL;
1923 	} else {
1924 		/*
1925 		 * Take two passes through the allprison list: first starting
1926 		 * with the proposed jid, then ending with it.
1927 		 */
1928 		for (maxid = JAIL_MAX; maxid != 0; ) {
1929 			TAILQ_FOREACH(inspr, &allprison, pr_list) {
1930 				if (inspr->pr_id < jid)
1931 					continue;
1932 				if (inspr->pr_id > jid) {
1933 					/* Found an opening. */
1934 					maxid = 0;
1935 					break;
1936 				}
1937 				if (++jid > maxid) {
1938 					if (lastprid == maxid || lastprid == 0)
1939 					{
1940 						/*
1941 						 * The entire legal range
1942 						 * has been traversed
1943 						 */
1944 						return 0;
1945 					}
1946 					/* Try again from the start. */
1947 					jid = 1;
1948 					maxid = lastprid;
1949 					break;
1950 				}
1951 			}
1952 			if (inspr == NULL) {
1953 				/* Found room at the end of the list. */
1954 				break;
1955 			}
1956 		}
1957 	}
1958 	*insprp = inspr;
1959 	lastprid = jid;
1960 	return (jid);
1961 }
1962 
1963 /*
1964  * struct jail_get_args {
1965  *	struct iovec *iovp;
1966  *	unsigned int iovcnt;
1967  *	int flags;
1968  * };
1969  */
1970 int
1971 sys_jail_get(struct thread *td, struct jail_get_args *uap)
1972 {
1973 	struct uio *auio;
1974 	int error;
1975 
1976 	/* Check that we have an even number of iovecs. */
1977 	if (uap->iovcnt & 1)
1978 		return (EINVAL);
1979 
1980 	error = copyinuio(uap->iovp, uap->iovcnt, &auio);
1981 	if (error)
1982 		return (error);
1983 	error = kern_jail_get(td, auio, uap->flags);
1984 	if (error == 0)
1985 		error = copyout(auio->uio_iov, uap->iovp,
1986 		    uap->iovcnt * sizeof (struct iovec));
1987 	free(auio, M_IOV);
1988 	return (error);
1989 }
1990 
1991 int
1992 kern_jail_get(struct thread *td, struct uio *optuio, int flags)
1993 {
1994 	struct bool_flags *bf;
1995 	struct jailsys_flags *jsf;
1996 	struct prison *pr, *mypr;
1997 	struct vfsopt *opt;
1998 	struct vfsoptlist *opts;
1999 	char *errmsg, *name;
2000 	int drflags, error, errmsg_len, errmsg_pos, i, jid, len, pos;
2001 	unsigned f;
2002 
2003 	if (flags & ~JAIL_GET_MASK)
2004 		return (EINVAL);
2005 
2006 	/* Get the parameter list. */
2007 	error = vfs_buildopts(optuio, &opts);
2008 	if (error)
2009 		return (error);
2010 	errmsg_pos = vfs_getopt_pos(opts, "errmsg");
2011 	mypr = td->td_ucred->cr_prison;
2012 	pr = NULL;
2013 
2014 	/*
2015 	 * Find the prison specified by one of: lastjid, jid, name.
2016 	 */
2017 	sx_slock(&allprison_lock);
2018 	drflags = PD_LIST_SLOCKED;
2019 	error = vfs_copyopt(opts, "lastjid", &jid, sizeof(jid));
2020 	if (error == 0) {
2021 		TAILQ_FOREACH(pr, &allprison, pr_list) {
2022 			if (pr->pr_id > jid &&
2023 			    ((flags & JAIL_DYING) || prison_isalive(pr)) &&
2024 			    prison_ischild(mypr, pr)) {
2025 				mtx_lock(&pr->pr_mtx);
2026 				drflags |= PD_LOCKED;
2027 				goto found_prison;
2028 			}
2029 		}
2030 		error = ENOENT;
2031 		vfs_opterror(opts, "no jail after %d", jid);
2032 		goto done;
2033 	} else if (error != ENOENT)
2034 		goto done;
2035 
2036 	error = vfs_copyopt(opts, "jid", &jid, sizeof(jid));
2037 	if (error == 0) {
2038 		if (jid != 0) {
2039 			pr = prison_find_child(mypr, jid);
2040 			if (pr != NULL) {
2041 				drflags |= PD_LOCKED;
2042 				if (!(prison_isalive(pr) ||
2043 				    (flags & JAIL_DYING))) {
2044 					error = ENOENT;
2045 					vfs_opterror(opts, "jail %d is dying",
2046 					    jid);
2047 					goto done;
2048 				}
2049 				goto found_prison;
2050 			}
2051 			error = ENOENT;
2052 			vfs_opterror(opts, "jail %d not found", jid);
2053 			goto done;
2054 		}
2055 	} else if (error != ENOENT)
2056 		goto done;
2057 
2058 	error = vfs_getopt(opts, "name", (void **)&name, &len);
2059 	if (error == 0) {
2060 		if (len == 0 || name[len - 1] != '\0') {
2061 			error = EINVAL;
2062 			goto done;
2063 		}
2064 		pr = prison_find_name(mypr, name);
2065 		if (pr != NULL) {
2066 			drflags |= PD_LOCKED;
2067 			if (!(prison_isalive(pr) || (flags & JAIL_DYING))) {
2068 				error = ENOENT;
2069 				vfs_opterror(opts, "jail \"%s\" is dying",
2070 				    name);
2071 				goto done;
2072 			}
2073 			goto found_prison;
2074 		}
2075 		error = ENOENT;
2076 		vfs_opterror(opts, "jail \"%s\" not found", name);
2077 		goto done;
2078 	} else if (error != ENOENT)
2079 		goto done;
2080 
2081 	vfs_opterror(opts, "no jail specified");
2082 	error = ENOENT;
2083 	goto done;
2084 
2085  found_prison:
2086 	/* Get the parameters of the prison. */
2087 	prison_hold(pr);
2088 	drflags |= PD_DEREF;
2089 	td->td_retval[0] = pr->pr_id;
2090 	error = vfs_setopt(opts, "jid", &pr->pr_id, sizeof(pr->pr_id));
2091 	if (error != 0 && error != ENOENT)
2092 		goto done;
2093 	i = (pr->pr_parent == mypr) ? 0 : pr->pr_parent->pr_id;
2094 	error = vfs_setopt(opts, "parent", &i, sizeof(i));
2095 	if (error != 0 && error != ENOENT)
2096 		goto done;
2097 	error = vfs_setopts(opts, "name", prison_name(mypr, pr));
2098 	if (error != 0 && error != ENOENT)
2099 		goto done;
2100 	error = vfs_setopt(opts, "cpuset.id", &pr->pr_cpuset->cs_id,
2101 	    sizeof(pr->pr_cpuset->cs_id));
2102 	if (error != 0 && error != ENOENT)
2103 		goto done;
2104 	error = vfs_setopts(opts, "path", prison_path(mypr, pr));
2105 	if (error != 0 && error != ENOENT)
2106 		goto done;
2107 #ifdef INET
2108 	error = vfs_setopt_part(opts, "ip4.addr", pr->pr_ip4,
2109 	    pr->pr_ip4s * sizeof(*pr->pr_ip4));
2110 	if (error != 0 && error != ENOENT)
2111 		goto done;
2112 #endif
2113 #ifdef INET6
2114 	error = vfs_setopt_part(opts, "ip6.addr", pr->pr_ip6,
2115 	    pr->pr_ip6s * sizeof(*pr->pr_ip6));
2116 	if (error != 0 && error != ENOENT)
2117 		goto done;
2118 #endif
2119 	error = vfs_setopt(opts, "securelevel", &pr->pr_securelevel,
2120 	    sizeof(pr->pr_securelevel));
2121 	if (error != 0 && error != ENOENT)
2122 		goto done;
2123 	error = vfs_setopt(opts, "children.cur", &pr->pr_childcount,
2124 	    sizeof(pr->pr_childcount));
2125 	if (error != 0 && error != ENOENT)
2126 		goto done;
2127 	error = vfs_setopt(opts, "children.max", &pr->pr_childmax,
2128 	    sizeof(pr->pr_childmax));
2129 	if (error != 0 && error != ENOENT)
2130 		goto done;
2131 	error = vfs_setopts(opts, "host.hostname", pr->pr_hostname);
2132 	if (error != 0 && error != ENOENT)
2133 		goto done;
2134 	error = vfs_setopts(opts, "host.domainname", pr->pr_domainname);
2135 	if (error != 0 && error != ENOENT)
2136 		goto done;
2137 	error = vfs_setopts(opts, "host.hostuuid", pr->pr_hostuuid);
2138 	if (error != 0 && error != ENOENT)
2139 		goto done;
2140 #ifdef COMPAT_FREEBSD32
2141 	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
2142 		uint32_t hid32 = pr->pr_hostid;
2143 
2144 		error = vfs_setopt(opts, "host.hostid", &hid32, sizeof(hid32));
2145 	} else
2146 #endif
2147 	error = vfs_setopt(opts, "host.hostid", &pr->pr_hostid,
2148 	    sizeof(pr->pr_hostid));
2149 	if (error != 0 && error != ENOENT)
2150 		goto done;
2151 	error = vfs_setopt(opts, "enforce_statfs", &pr->pr_enforce_statfs,
2152 	    sizeof(pr->pr_enforce_statfs));
2153 	if (error != 0 && error != ENOENT)
2154 		goto done;
2155 	error = vfs_setopt(opts, "devfs_ruleset", &pr->pr_devfs_rsnum,
2156 	    sizeof(pr->pr_devfs_rsnum));
2157 	if (error != 0 && error != ENOENT)
2158 		goto done;
2159 	for (bf = pr_flag_bool;
2160 	     bf < pr_flag_bool + nitems(pr_flag_bool);
2161 	     bf++) {
2162 		i = (pr->pr_flags & bf->flag) ? 1 : 0;
2163 		error = vfs_setopt(opts, bf->name, &i, sizeof(i));
2164 		if (error != 0 && error != ENOENT)
2165 			goto done;
2166 		i = !i;
2167 		error = vfs_setopt(opts, bf->noname, &i, sizeof(i));
2168 		if (error != 0 && error != ENOENT)
2169 			goto done;
2170 	}
2171 	for (jsf = pr_flag_jailsys;
2172 	     jsf < pr_flag_jailsys + nitems(pr_flag_jailsys);
2173 	     jsf++) {
2174 		f = pr->pr_flags & (jsf->disable | jsf->new);
2175 		i = (f != 0 && f == jsf->disable) ? JAIL_SYS_DISABLE
2176 		    : (f == jsf->new) ? JAIL_SYS_NEW
2177 		    : JAIL_SYS_INHERIT;
2178 		error = vfs_setopt(opts, jsf->name, &i, sizeof(i));
2179 		if (error != 0 && error != ENOENT)
2180 			goto done;
2181 	}
2182 	for (bf = pr_flag_allow;
2183 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
2184 		atomic_load_int(&bf->flag) != 0;
2185 	     bf++) {
2186 		i = (pr->pr_allow & bf->flag) ? 1 : 0;
2187 		error = vfs_setopt(opts, bf->name, &i, sizeof(i));
2188 		if (error != 0 && error != ENOENT)
2189 			goto done;
2190 		i = !i;
2191 		error = vfs_setopt(opts, bf->noname, &i, sizeof(i));
2192 		if (error != 0 && error != ENOENT)
2193 			goto done;
2194 	}
2195 	i = !prison_isalive(pr);
2196 	error = vfs_setopt(opts, "dying", &i, sizeof(i));
2197 	if (error != 0 && error != ENOENT)
2198 		goto done;
2199 	i = !i;
2200 	error = vfs_setopt(opts, "nodying", &i, sizeof(i));
2201 	if (error != 0 && error != ENOENT)
2202 		goto done;
2203 	error = vfs_setopt(opts, "osreldate", &pr->pr_osreldate,
2204 	    sizeof(pr->pr_osreldate));
2205 	if (error != 0 && error != ENOENT)
2206 		goto done;
2207 	error = vfs_setopts(opts, "osrelease", pr->pr_osrelease);
2208 	if (error != 0 && error != ENOENT)
2209 		goto done;
2210 
2211 	/* Get the module parameters. */
2212 	mtx_unlock(&pr->pr_mtx);
2213 	drflags &= ~PD_LOCKED;
2214 	error = osd_jail_call(pr, PR_METHOD_GET, opts);
2215 	if (error)
2216 		goto done;
2217 	prison_deref(pr, drflags);
2218 	pr = NULL;
2219 	drflags = 0;
2220 
2221 	/* By now, all parameters should have been noted. */
2222 	TAILQ_FOREACH(opt, opts, link) {
2223 		if (!opt->seen && strcmp(opt->name, "errmsg")) {
2224 			error = EINVAL;
2225 			vfs_opterror(opts, "unknown parameter: %s", opt->name);
2226 			goto done;
2227 		}
2228 	}
2229 
2230 	/* Write the fetched parameters back to userspace. */
2231 	error = 0;
2232 	TAILQ_FOREACH(opt, opts, link) {
2233 		if (opt->pos >= 0 && opt->pos != errmsg_pos) {
2234 			pos = 2 * opt->pos + 1;
2235 			optuio->uio_iov[pos].iov_len = opt->len;
2236 			if (opt->value != NULL) {
2237 				if (optuio->uio_segflg == UIO_SYSSPACE) {
2238 					bcopy(opt->value,
2239 					    optuio->uio_iov[pos].iov_base,
2240 					    opt->len);
2241 				} else {
2242 					error = copyout(opt->value,
2243 					    optuio->uio_iov[pos].iov_base,
2244 					    opt->len);
2245 					if (error)
2246 						break;
2247 				}
2248 			}
2249 		}
2250 	}
2251 
2252  done:
2253 	/* Release any temporary prison holds and/or locks. */
2254 	if (pr != NULL)
2255 		prison_deref(pr, drflags);
2256 	else if (drflags & PD_LIST_SLOCKED)
2257 		sx_sunlock(&allprison_lock);
2258 	if (error && errmsg_pos >= 0) {
2259 		/* Write the error message back to userspace. */
2260 		vfs_getopt(opts, "errmsg", (void **)&errmsg, &errmsg_len);
2261 		errmsg_pos = 2 * errmsg_pos + 1;
2262 		if (errmsg_len > 0) {
2263 			if (optuio->uio_segflg == UIO_SYSSPACE)
2264 				bcopy(errmsg,
2265 				    optuio->uio_iov[errmsg_pos].iov_base,
2266 				    errmsg_len);
2267 			else
2268 				copyout(errmsg,
2269 				    optuio->uio_iov[errmsg_pos].iov_base,
2270 				    errmsg_len);
2271 		}
2272 	}
2273 	vfs_freeopts(opts);
2274 	return (error);
2275 }
2276 
2277 /*
2278  * struct jail_remove_args {
2279  *	int jid;
2280  * };
2281  */
2282 int
2283 sys_jail_remove(struct thread *td, struct jail_remove_args *uap)
2284 {
2285 	struct prison *pr;
2286 	int error;
2287 
2288 	error = priv_check(td, PRIV_JAIL_REMOVE);
2289 	if (error)
2290 		return (error);
2291 
2292 	sx_xlock(&allprison_lock);
2293 	pr = prison_find_child(td->td_ucred->cr_prison, uap->jid);
2294 	if (pr == NULL) {
2295 		sx_xunlock(&allprison_lock);
2296 		return (EINVAL);
2297 	}
2298 	if (!prison_isalive(pr)) {
2299 		/* Silently ignore already-dying prisons. */
2300 		mtx_unlock(&pr->pr_mtx);
2301 		sx_xunlock(&allprison_lock);
2302 		return (0);
2303 	}
2304 	prison_deref(pr, PD_KILL | PD_LOCKED | PD_LIST_XLOCKED);
2305 	return (0);
2306 }
2307 
2308 /*
2309  * struct jail_attach_args {
2310  *	int jid;
2311  * };
2312  */
2313 int
2314 sys_jail_attach(struct thread *td, struct jail_attach_args *uap)
2315 {
2316 	struct prison *pr;
2317 	int error;
2318 
2319 	error = priv_check(td, PRIV_JAIL_ATTACH);
2320 	if (error)
2321 		return (error);
2322 
2323 	sx_slock(&allprison_lock);
2324 	pr = prison_find_child(td->td_ucred->cr_prison, uap->jid);
2325 	if (pr == NULL) {
2326 		sx_sunlock(&allprison_lock);
2327 		return (EINVAL);
2328 	}
2329 
2330 	/* Do not allow a process to attach to a prison that is not alive. */
2331 	if (!prison_isalive(pr)) {
2332 		mtx_unlock(&pr->pr_mtx);
2333 		sx_sunlock(&allprison_lock);
2334 		return (EINVAL);
2335 	}
2336 
2337 	return (do_jail_attach(td, pr, PD_LOCKED | PD_LIST_SLOCKED));
2338 }
2339 
2340 static int
2341 do_jail_attach(struct thread *td, struct prison *pr, int drflags)
2342 {
2343 	struct proc *p;
2344 	struct ucred *newcred, *oldcred;
2345 	int error;
2346 
2347 	mtx_assert(&pr->pr_mtx, MA_OWNED);
2348 	sx_assert(&allprison_lock, SX_LOCKED);
2349 	drflags &= PD_LOCK_FLAGS;
2350 	/*
2351 	 * XXX: Note that there is a slight race here if two threads
2352 	 * in the same privileged process attempt to attach to two
2353 	 * different jails at the same time.  It is important for
2354 	 * user processes not to do this, or they might end up with
2355 	 * a process root from one prison, but attached to the jail
2356 	 * of another.
2357 	 */
2358 	prison_hold(pr);
2359 	refcount_acquire(&pr->pr_uref);
2360 	drflags |= PD_DEREF | PD_DEUREF;
2361 	mtx_unlock(&pr->pr_mtx);
2362 	drflags &= ~PD_LOCKED;
2363 
2364 	/* Let modules do whatever they need to prepare for attaching. */
2365 	error = osd_jail_call(pr, PR_METHOD_ATTACH, td);
2366 	if (error) {
2367 		prison_deref(pr, drflags);
2368 		return (error);
2369 	}
2370 	sx_unlock(&allprison_lock);
2371 	drflags &= ~(PD_LIST_SLOCKED | PD_LIST_XLOCKED);
2372 
2373 	/*
2374 	 * Reparent the newly attached process to this jail.
2375 	 */
2376 	p = td->td_proc;
2377 	error = cpuset_setproc_update_set(p, pr->pr_cpuset);
2378 	if (error)
2379 		goto e_revert_osd;
2380 
2381 	vn_lock(pr->pr_root, LK_EXCLUSIVE | LK_RETRY);
2382 	if ((error = change_dir(pr->pr_root, td)) != 0)
2383 		goto e_unlock;
2384 #ifdef MAC
2385 	if ((error = mac_vnode_check_chroot(td->td_ucred, pr->pr_root)))
2386 		goto e_unlock;
2387 #endif
2388 	VOP_UNLOCK(pr->pr_root);
2389 	if ((error = pwd_chroot_chdir(td, pr->pr_root)))
2390 		goto e_revert_osd;
2391 
2392 	newcred = crget();
2393 	PROC_LOCK(p);
2394 	oldcred = crcopysafe(p, newcred);
2395 	newcred->cr_prison = pr;
2396 	proc_set_cred(p, newcred);
2397 	setsugid(p);
2398 #ifdef RACCT
2399 	racct_proc_ucred_changed(p, oldcred, newcred);
2400 	crhold(newcred);
2401 #endif
2402 	PROC_UNLOCK(p);
2403 #ifdef RCTL
2404 	rctl_proc_ucred_changed(p, newcred);
2405 	crfree(newcred);
2406 #endif
2407 	prison_deref(oldcred->cr_prison, drflags);
2408 	crfree(oldcred);
2409 
2410 	/*
2411 	 * If the prison was killed while changing credentials, die along
2412 	 * with it.
2413 	 */
2414 	if (!prison_isalive(pr)) {
2415 		PROC_LOCK(p);
2416 		kern_psignal(p, SIGKILL);
2417 		PROC_UNLOCK(p);
2418 	}
2419 
2420 	return (0);
2421 
2422  e_unlock:
2423 	VOP_UNLOCK(pr->pr_root);
2424  e_revert_osd:
2425 	/* Tell modules this thread is still in its old jail after all. */
2426 	sx_slock(&allprison_lock);
2427 	drflags |= PD_LIST_SLOCKED;
2428 	(void)osd_jail_call(td->td_ucred->cr_prison, PR_METHOD_ATTACH, td);
2429 	prison_deref(pr, drflags);
2430 	return (error);
2431 }
2432 
2433 /*
2434  * Returns a locked prison instance, or NULL on failure.
2435  */
2436 struct prison *
2437 prison_find(int prid)
2438 {
2439 	struct prison *pr;
2440 
2441 	sx_assert(&allprison_lock, SX_LOCKED);
2442 	TAILQ_FOREACH(pr, &allprison, pr_list) {
2443 		if (pr->pr_id < prid)
2444 			continue;
2445 		if (pr->pr_id > prid)
2446 			break;
2447 		KASSERT(prison_isvalid(pr), ("Found invalid prison %p", pr));
2448 		mtx_lock(&pr->pr_mtx);
2449 		return (pr);
2450 	}
2451 	return (NULL);
2452 }
2453 
2454 /*
2455  * Find a prison that is a descendant of mypr.  Returns a locked prison or NULL.
2456  */
2457 struct prison *
2458 prison_find_child(struct prison *mypr, int prid)
2459 {
2460 	struct prison *pr;
2461 	int descend;
2462 
2463 	sx_assert(&allprison_lock, SX_LOCKED);
2464 	FOREACH_PRISON_DESCENDANT(mypr, pr, descend) {
2465 		if (pr->pr_id == prid) {
2466 			KASSERT(prison_isvalid(pr),
2467 			    ("Found invalid prison %p", pr));
2468 			mtx_lock(&pr->pr_mtx);
2469 			return (pr);
2470 		}
2471 	}
2472 	return (NULL);
2473 }
2474 
2475 /*
2476  * Look for the name relative to mypr.  Returns a locked prison or NULL.
2477  */
2478 struct prison *
2479 prison_find_name(struct prison *mypr, const char *name)
2480 {
2481 	struct prison *pr, *deadpr;
2482 	size_t mylen;
2483 	int descend;
2484 
2485 	sx_assert(&allprison_lock, SX_LOCKED);
2486 	mylen = (mypr == &prison0) ? 0 : strlen(mypr->pr_name) + 1;
2487 	deadpr = NULL;
2488 	FOREACH_PRISON_DESCENDANT(mypr, pr, descend) {
2489 		if (!strcmp(pr->pr_name + mylen, name)) {
2490 			KASSERT(prison_isvalid(pr),
2491 			    ("Found invalid prison %p", pr));
2492 			if (prison_isalive(pr)) {
2493 				mtx_lock(&pr->pr_mtx);
2494 				return (pr);
2495 			}
2496 			deadpr = pr;
2497 		}
2498 	}
2499 	/* There was no valid prison - perhaps there was a dying one. */
2500 	if (deadpr != NULL)
2501 		mtx_lock(&deadpr->pr_mtx);
2502 	return (deadpr);
2503 }
2504 
2505 /*
2506  * See if a prison has the specific flag set.  The prison should be locked,
2507  * unless checking for flags that are only set at jail creation (such as
2508  * PR_IP4 and PR_IP6), or only the single bit is examined, without regard
2509  * to any other prison data.
2510  */
2511 int
2512 prison_flag(struct ucred *cred, unsigned flag)
2513 {
2514 
2515 	return (cred->cr_prison->pr_flags & flag);
2516 }
2517 
2518 int
2519 prison_allow(struct ucred *cred, unsigned flag)
2520 {
2521 
2522 	return ((cred->cr_prison->pr_allow & flag) != 0);
2523 }
2524 
2525 /*
2526  * Hold a prison reference, by incrementing pr_ref.  It is generally
2527  * an error to hold a prison that does not already have a reference.
2528  * A prison record will remain valid as long as it has at least one
2529  * reference, and will not be removed as long as either the prison
2530  * mutex or the allprison lock is held (allprison_lock may be shared).
2531  */
2532 void
2533 prison_hold_locked(struct prison *pr)
2534 {
2535 
2536 	/* Locking is no longer required. */
2537 	prison_hold(pr);
2538 }
2539 
2540 void
2541 prison_hold(struct prison *pr)
2542 {
2543 #ifdef INVARIANTS
2544 	int was_valid = refcount_acquire_if_not_zero(&pr->pr_ref);
2545 
2546 	KASSERT(was_valid,
2547 	    ("Trying to hold dead prison %p (jid=%d).", pr, pr->pr_id));
2548 #else
2549 	refcount_acquire(&pr->pr_ref);
2550 #endif
2551 }
2552 
2553 /*
2554  * Remove a prison reference.  If that was the last reference, the
2555  * prison will be removed (at a later time).
2556  */
2557 void
2558 prison_free_locked(struct prison *pr)
2559 {
2560 
2561 	mtx_assert(&pr->pr_mtx, MA_OWNED);
2562 	/*
2563 	 * Locking is no longer required, but unlock because the caller
2564 	 * expects it.
2565 	 */
2566 	mtx_unlock(&pr->pr_mtx);
2567 	prison_free(pr);
2568 }
2569 
2570 void
2571 prison_free(struct prison *pr)
2572 {
2573 
2574 	KASSERT(refcount_load(&pr->pr_ref) > 0,
2575 	    ("Trying to free dead prison %p (jid=%d).",
2576 	     pr, pr->pr_id));
2577 	if (!refcount_release_if_not_last(&pr->pr_ref)) {
2578 		/*
2579 		 * Don't remove the last reference in this context,
2580 		 * in case there are locks held.
2581 		 */
2582 		taskqueue_enqueue(taskqueue_thread, &pr->pr_task);
2583 	}
2584 }
2585 
2586 static void
2587 prison_free_not_last(struct prison *pr)
2588 {
2589 #ifdef INVARIANTS
2590 	int lastref;
2591 
2592 	KASSERT(refcount_load(&pr->pr_ref) > 0,
2593 	    ("Trying to free dead prison %p (jid=%d).",
2594 	     pr, pr->pr_id));
2595 	lastref = refcount_release(&pr->pr_ref);
2596 	KASSERT(!lastref,
2597 	    ("prison_free_not_last freed last ref on prison %p (jid=%d).",
2598 	     pr, pr->pr_id));
2599 #else
2600 	refcount_release(&pr->pr_ref);
2601 #endif
2602 }
2603 
2604 /*
2605  * Hold a a prison for user visibility, by incrementing pr_uref.
2606  * It is generally an error to hold a prison that isn't already
2607  * user-visible, except through the the jail system calls.  It is also
2608  * an error to hold an invalid prison.  A prison record will remain
2609  * alive as long as it has at least one user reference, and will not
2610  * be set to the dying state until the prison mutex and allprison_lock
2611  * are both freed.
2612  */
2613 void
2614 prison_proc_hold(struct prison *pr)
2615 {
2616 #ifdef INVARIANTS
2617 	int was_alive = refcount_acquire_if_not_zero(&pr->pr_uref);
2618 
2619 	KASSERT(was_alive,
2620 	    ("Cannot add a process to a non-alive prison (jid=%d)", pr->pr_id));
2621 #else
2622 	refcount_acquire(&pr->pr_uref);
2623 #endif
2624 }
2625 
2626 /*
2627  * Remove a prison user reference.  If it was the last reference, the
2628  * prison will be considered "dying", and may be removed once all of
2629  * its references are dropped.
2630  */
2631 void
2632 prison_proc_free(struct prison *pr)
2633 {
2634 
2635 	/*
2636 	 * Locking is only required when releasing the last reference.
2637 	 * This allows assurance that a locked prison will remain alive
2638 	 * until it is unlocked.
2639 	 */
2640 	KASSERT(refcount_load(&pr->pr_uref) > 0,
2641 	    ("Trying to kill a process in a dead prison (jid=%d)", pr->pr_id));
2642 	if (!refcount_release_if_not_last(&pr->pr_uref)) {
2643 		/*
2644 		 * Don't remove the last user reference in this context,
2645 		 * which is expected to be a process that is not only locked,
2646 		 * but also half dead.  Add a reference so any calls to
2647 		 * prison_free() won't re-submit the task.
2648 		 */
2649 		prison_hold(pr);
2650 		mtx_lock(&pr->pr_mtx);
2651 		KASSERT(!(pr->pr_flags & PR_COMPLETE_PROC),
2652 		    ("Redundant last reference in prison_proc_free (jid=%d)",
2653 		     pr->pr_id));
2654 		pr->pr_flags |= PR_COMPLETE_PROC;
2655 		mtx_unlock(&pr->pr_mtx);
2656 		taskqueue_enqueue(taskqueue_thread, &pr->pr_task);
2657 	}
2658 }
2659 
2660 static void
2661 prison_proc_free_not_last(struct prison *pr)
2662 {
2663 #ifdef INVARIANTS
2664 	int lastref;
2665 
2666 	KASSERT(refcount_load(&pr->pr_uref) > 0,
2667 	    ("Trying to free dead prison %p (jid=%d).",
2668 	     pr, pr->pr_id));
2669 	lastref = refcount_release(&pr->pr_uref);
2670 	KASSERT(!lastref,
2671 	    ("prison_proc_free_not_last freed last uref on prison %p (jid=%d).",
2672 	     pr, pr->pr_id));
2673 #else
2674 	refcount_release(&pr->pr_uref);
2675 #endif
2676 }
2677 
2678 /*
2679  * Complete a call to either prison_free or prison_proc_free.
2680  */
2681 static void
2682 prison_complete(void *context, int pending)
2683 {
2684 	struct prison *pr = context;
2685 	int drflags;
2686 
2687 	/*
2688 	 * This could be called to release the last reference, or the last
2689 	 * user reference (plus the reference held in prison_proc_free).
2690 	 */
2691 	drflags = prison_lock_xlock(pr, PD_DEREF);
2692 	if (pr->pr_flags & PR_COMPLETE_PROC) {
2693 		pr->pr_flags &= ~PR_COMPLETE_PROC;
2694 		drflags |= PD_DEUREF;
2695 	}
2696 	prison_deref(pr, drflags);
2697 }
2698 
2699 /*
2700  * Remove a prison reference and/or user reference (usually).
2701  * This assumes context that allows sleeping (for allprison_lock),
2702  * with no non-sleeping locks held, except perhaps the prison itself.
2703  * If there are no more references, release and delist the prison.
2704  * On completion, the prison lock and the allprison lock are both
2705  * unlocked.
2706  */
2707 static void
2708 prison_deref(struct prison *pr, int flags)
2709 {
2710 	struct prisonlist freeprison;
2711 	struct prison *killpr, *rpr, *ppr, *tpr;
2712 	struct proc *p;
2713 
2714 	killpr = NULL;
2715 	TAILQ_INIT(&freeprison);
2716 	/*
2717 	 * Release this prison as requested, which may cause its parent
2718 	 * to be released, and then maybe its grandparent, etc.
2719 	 */
2720 	for (;;) {
2721 		if (flags & PD_KILL) {
2722 			/* Kill the prison and its descendents. */
2723 			KASSERT(pr != &prison0,
2724 			    ("prison_deref trying to kill prison0"));
2725 			if (!(flags & PD_DEREF)) {
2726 				prison_hold(pr);
2727 				flags |= PD_DEREF;
2728 			}
2729 			flags = prison_lock_xlock(pr, flags);
2730 			prison_deref_kill(pr, &freeprison);
2731 		}
2732 		if (flags & PD_DEUREF) {
2733 			/* Drop a user reference. */
2734 			KASSERT(refcount_load(&pr->pr_uref) > 0,
2735 			    ("prison_deref PD_DEUREF on a dead prison (jid=%d)",
2736 			     pr->pr_id));
2737 			if (!refcount_release_if_not_last(&pr->pr_uref)) {
2738 				if (!(flags & PD_DEREF)) {
2739 					prison_hold(pr);
2740 					flags |= PD_DEREF;
2741 				}
2742 				flags = prison_lock_xlock(pr, flags);
2743 				if (refcount_release(&pr->pr_uref) &&
2744 				    pr->pr_state == PRISON_STATE_ALIVE) {
2745 					/*
2746 					 * When the last user references goes,
2747 					 * this becomes a dying prison.
2748 					 */
2749 					KASSERT(
2750 					    refcount_load(&prison0.pr_uref) > 0,
2751 					    ("prison0 pr_uref=0"));
2752 					pr->pr_state = PRISON_STATE_DYING;
2753 					mtx_unlock(&pr->pr_mtx);
2754 					flags &= ~PD_LOCKED;
2755 					(void)osd_jail_call(pr,
2756 					    PR_METHOD_REMOVE, NULL);
2757 				}
2758 			}
2759 		}
2760 		if (flags & PD_KILL) {
2761 			/*
2762 			 * Any remaining user references are probably processes
2763 			 * that need to be killed, either in this prison or its
2764 			 * descendants.
2765 			 */
2766 			if (refcount_load(&pr->pr_uref) > 0)
2767 				killpr = pr;
2768 			/* Make sure the parent prison doesn't get killed. */
2769 			flags &= ~PD_KILL;
2770 		}
2771 		if (flags & PD_DEREF) {
2772 			/* Drop a reference. */
2773 			KASSERT(refcount_load(&pr->pr_ref) > 0,
2774 			    ("prison_deref PD_DEREF on a dead prison (jid=%d)",
2775 			     pr->pr_id));
2776 			if (!refcount_release_if_not_last(&pr->pr_ref)) {
2777 				flags = prison_lock_xlock(pr, flags);
2778 				if (refcount_release(&pr->pr_ref)) {
2779 					/*
2780 					 * When the last reference goes,
2781 					 * unlink the prison and set it aside.
2782 					 */
2783 					KASSERT(
2784 					    refcount_load(&pr->pr_uref) == 0,
2785 					    ("prison_deref: last ref, "
2786 					     "but still has %d urefs (jid=%d)",
2787 					     pr->pr_uref, pr->pr_id));
2788 					KASSERT(
2789 					    refcount_load(&prison0.pr_ref) != 0,
2790 					    ("prison0 pr_ref=0"));
2791 					pr->pr_state = PRISON_STATE_INVALID;
2792 					TAILQ_REMOVE(&allprison, pr, pr_list);
2793 					LIST_REMOVE(pr, pr_sibling);
2794 					TAILQ_INSERT_TAIL(&freeprison, pr,
2795 					    pr_list);
2796 					for (ppr = pr->pr_parent;
2797 					     ppr != NULL;
2798 					     ppr = ppr->pr_parent)
2799 						ppr->pr_childcount--;
2800 					/*
2801 					 * Removing a prison frees references
2802 					 * from its parent.
2803 					 */
2804 					mtx_unlock(&pr->pr_mtx);
2805 					flags &= ~PD_LOCKED;
2806 					pr = pr->pr_parent;
2807 					flags |= PD_DEREF | PD_DEUREF;
2808 					continue;
2809 				}
2810 			}
2811 		}
2812 		break;
2813 	}
2814 
2815 	/* Release all the prison locks. */
2816 	if (flags & PD_LOCKED)
2817 		mtx_unlock(&pr->pr_mtx);
2818 	if (flags & PD_LIST_SLOCKED)
2819 		sx_sunlock(&allprison_lock);
2820 	else if (flags & PD_LIST_XLOCKED)
2821 		sx_xunlock(&allprison_lock);
2822 
2823 	/* Kill any processes attached to a killed prison. */
2824 	if (killpr != NULL) {
2825 		sx_slock(&allproc_lock);
2826 		FOREACH_PROC_IN_SYSTEM(p) {
2827 			PROC_LOCK(p);
2828 			if (p->p_state != PRS_NEW && p->p_ucred != NULL) {
2829 				for (ppr = p->p_ucred->cr_prison;
2830 				     ppr != &prison0;
2831 				     ppr = ppr->pr_parent)
2832 					if (ppr == killpr) {
2833 						kern_psignal(p, SIGKILL);
2834 						break;
2835 					}
2836 			}
2837 			PROC_UNLOCK(p);
2838 		}
2839 		sx_sunlock(&allproc_lock);
2840 	}
2841 
2842 	/*
2843 	 * Finish removing any unreferenced prisons, which couldn't happen
2844 	 * while allprison_lock was held (to avoid a LOR on vrele).
2845 	 */
2846 	TAILQ_FOREACH_SAFE(rpr, &freeprison, pr_list, tpr) {
2847 #ifdef VIMAGE
2848 		if (rpr->pr_vnet != rpr->pr_parent->pr_vnet)
2849 			vnet_destroy(rpr->pr_vnet);
2850 #endif
2851 		if (rpr->pr_root != NULL)
2852 			vrele(rpr->pr_root);
2853 		mtx_destroy(&rpr->pr_mtx);
2854 #ifdef INET
2855 		free(rpr->pr_ip4, M_PRISON);
2856 #endif
2857 #ifdef INET6
2858 		free(rpr->pr_ip6, M_PRISON);
2859 #endif
2860 		if (rpr->pr_cpuset != NULL)
2861 			cpuset_rel(rpr->pr_cpuset);
2862 		osd_jail_exit(rpr);
2863 #ifdef RACCT
2864 		if (racct_enable)
2865 			prison_racct_detach(rpr);
2866 #endif
2867 		TAILQ_REMOVE(&freeprison, rpr, pr_list);
2868 		free(rpr, M_PRISON);
2869 	}
2870 }
2871 
2872 /*
2873  * Kill the prison and its descendants.  Mark them as dying, clear the
2874  * persist flag, and call module remove methods.
2875  */
2876 static void
2877 prison_deref_kill(struct prison *pr, struct prisonlist *freeprison)
2878 {
2879 	struct prison *cpr, *ppr, *rpr;
2880 	bool descend;
2881 
2882 	/*
2883 	 * Unlike the descendants, the target prison can be killed
2884 	 * even if it is currently dying.  This is useful for failed
2885 	 * creation in jail_set(2).
2886 	 */
2887 	KASSERT(refcount_load(&pr->pr_ref) > 0,
2888 	    ("Trying to kill dead prison %p (jid=%d).",
2889 	     pr, pr->pr_id));
2890 	refcount_acquire(&pr->pr_uref);
2891 	pr->pr_state = PRISON_STATE_DYING;
2892 	mtx_unlock(&pr->pr_mtx);
2893 
2894 	rpr = NULL;
2895 	FOREACH_PRISON_DESCENDANT_PRE_POST(pr, cpr, descend) {
2896 		if (descend) {
2897 			if (!prison_isalive(cpr)) {
2898 				descend = false;
2899 				continue;
2900 			}
2901 			prison_hold(cpr);
2902 			prison_proc_hold(cpr);
2903 			mtx_lock(&cpr->pr_mtx);
2904 			cpr->pr_state = PRISON_STATE_DYING;
2905 			cpr->pr_flags |= PR_REMOVE;
2906 			mtx_unlock(&cpr->pr_mtx);
2907 			continue;
2908 		}
2909 		if (!(cpr->pr_flags & PR_REMOVE))
2910 			continue;
2911 		(void)osd_jail_call(cpr, PR_METHOD_REMOVE, NULL);
2912 		mtx_lock(&cpr->pr_mtx);
2913 		cpr->pr_flags &= ~PR_REMOVE;
2914 		if (cpr->pr_flags & PR_PERSIST) {
2915 			cpr->pr_flags &= ~PR_PERSIST;
2916 			prison_proc_free_not_last(cpr);
2917 			prison_free_not_last(cpr);
2918 		}
2919 		(void)refcount_release(&cpr->pr_uref);
2920 		if (refcount_release(&cpr->pr_ref)) {
2921 			/*
2922 			 * When the last reference goes, unlink the prison
2923 			 * and set it aside for prison_deref() to handle.
2924 			 * Delay unlinking the sibling list to keep the loop
2925 			 * safe.
2926 			 */
2927 			if (rpr != NULL)
2928 				LIST_REMOVE(rpr, pr_sibling);
2929 			rpr = cpr;
2930 			rpr->pr_state = PRISON_STATE_INVALID;
2931 			TAILQ_REMOVE(&allprison, rpr, pr_list);
2932 			TAILQ_INSERT_TAIL(freeprison, rpr, pr_list);
2933 			/*
2934 			 * Removing a prison frees references from its parent.
2935 			 */
2936 			ppr = rpr->pr_parent;
2937 			prison_proc_free_not_last(ppr);
2938 			prison_free_not_last(ppr);
2939 			for (; ppr != NULL; ppr = ppr->pr_parent)
2940 				ppr->pr_childcount--;
2941 		}
2942 		mtx_unlock(&cpr->pr_mtx);
2943 	}
2944 	if (rpr != NULL)
2945 		LIST_REMOVE(rpr, pr_sibling);
2946 
2947 	(void)osd_jail_call(pr, PR_METHOD_REMOVE, NULL);
2948 	mtx_lock(&pr->pr_mtx);
2949 	if (pr->pr_flags & PR_PERSIST) {
2950 		pr->pr_flags &= ~PR_PERSIST;
2951 		prison_proc_free_not_last(pr);
2952 		prison_free_not_last(pr);
2953 	}
2954 	(void)refcount_release(&pr->pr_uref);
2955 }
2956 
2957 /*
2958  * Given the current locking state in the flags, make sure allprison_lock
2959  * is held exclusive, and the prison is locked.  Return flags indicating
2960  * the new state.
2961  */
2962 static int
2963 prison_lock_xlock(struct prison *pr, int flags)
2964 {
2965 
2966 	if (!(flags & PD_LIST_XLOCKED)) {
2967 		/*
2968 		 * Get allprison_lock, which may be an upgrade,
2969 		 * and may require unlocking the prison.
2970 		 */
2971 		if (flags & PD_LOCKED) {
2972 			mtx_unlock(&pr->pr_mtx);
2973 			flags &= ~PD_LOCKED;
2974 		}
2975 		if (flags & PD_LIST_SLOCKED) {
2976 			if (!sx_try_upgrade(&allprison_lock)) {
2977 				sx_sunlock(&allprison_lock);
2978 				sx_xlock(&allprison_lock);
2979 			}
2980 			flags &= ~PD_LIST_SLOCKED;
2981 		} else
2982 			sx_xlock(&allprison_lock);
2983 		flags |= PD_LIST_XLOCKED;
2984 	}
2985 	if (!(flags & PD_LOCKED)) {
2986 		/* Lock the prison mutex. */
2987 		mtx_lock(&pr->pr_mtx);
2988 		flags |= PD_LOCKED;
2989 	}
2990 	return flags;
2991 }
2992 
2993 /*
2994  * Set or clear a permission bit in the pr_allow field, passing restrictions
2995  * (cleared permission) down to child jails.
2996  */
2997 void
2998 prison_set_allow(struct ucred *cred, unsigned flag, int enable)
2999 {
3000 	struct prison *pr;
3001 
3002 	pr = cred->cr_prison;
3003 	sx_slock(&allprison_lock);
3004 	mtx_lock(&pr->pr_mtx);
3005 	prison_set_allow_locked(pr, flag, enable);
3006 	mtx_unlock(&pr->pr_mtx);
3007 	sx_sunlock(&allprison_lock);
3008 }
3009 
3010 static void
3011 prison_set_allow_locked(struct prison *pr, unsigned flag, int enable)
3012 {
3013 	struct prison *cpr;
3014 	int descend;
3015 
3016 	if (enable != 0)
3017 		pr->pr_allow |= flag;
3018 	else {
3019 		pr->pr_allow &= ~flag;
3020 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
3021 			cpr->pr_allow &= ~flag;
3022 	}
3023 }
3024 
3025 /*
3026  * Check if a jail supports the given address family.
3027  *
3028  * Returns 0 if not jailed or the address family is supported, EAFNOSUPPORT
3029  * if not.
3030  */
3031 int
3032 prison_check_af(struct ucred *cred, int af)
3033 {
3034 	struct prison *pr;
3035 	int error;
3036 
3037 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3038 
3039 	pr = cred->cr_prison;
3040 #ifdef VIMAGE
3041 	/* Prisons with their own network stack are not limited. */
3042 	if (prison_owns_vnet(cred))
3043 		return (0);
3044 #endif
3045 
3046 	error = 0;
3047 	switch (af)
3048 	{
3049 #ifdef INET
3050 	case AF_INET:
3051 		if (pr->pr_flags & PR_IP4)
3052 		{
3053 			mtx_lock(&pr->pr_mtx);
3054 			if ((pr->pr_flags & PR_IP4) && pr->pr_ip4 == NULL)
3055 				error = EAFNOSUPPORT;
3056 			mtx_unlock(&pr->pr_mtx);
3057 		}
3058 		break;
3059 #endif
3060 #ifdef INET6
3061 	case AF_INET6:
3062 		if (pr->pr_flags & PR_IP6)
3063 		{
3064 			mtx_lock(&pr->pr_mtx);
3065 			if ((pr->pr_flags & PR_IP6) && pr->pr_ip6 == NULL)
3066 				error = EAFNOSUPPORT;
3067 			mtx_unlock(&pr->pr_mtx);
3068 		}
3069 		break;
3070 #endif
3071 	case AF_LOCAL:
3072 	case AF_ROUTE:
3073 		break;
3074 	default:
3075 		if (!(pr->pr_allow & PR_ALLOW_SOCKET_AF))
3076 			error = EAFNOSUPPORT;
3077 	}
3078 	return (error);
3079 }
3080 
3081 /*
3082  * Check if given address belongs to the jail referenced by cred (wrapper to
3083  * prison_check_ip[46]).
3084  *
3085  * Returns 0 if jail doesn't restrict the address family or if address belongs
3086  * to jail, EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if
3087  * the jail doesn't allow the address family.  IPv4 Address passed in in NBO.
3088  */
3089 int
3090 prison_if(struct ucred *cred, const struct sockaddr *sa)
3091 {
3092 #ifdef INET
3093 	const struct sockaddr_in *sai;
3094 #endif
3095 #ifdef INET6
3096 	const struct sockaddr_in6 *sai6;
3097 #endif
3098 	int error;
3099 
3100 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3101 	KASSERT(sa != NULL, ("%s: sa is NULL", __func__));
3102 
3103 #ifdef VIMAGE
3104 	if (prison_owns_vnet(cred))
3105 		return (0);
3106 #endif
3107 
3108 	error = 0;
3109 	switch (sa->sa_family)
3110 	{
3111 #ifdef INET
3112 	case AF_INET:
3113 		sai = (const struct sockaddr_in *)sa;
3114 		error = prison_check_ip4(cred, &sai->sin_addr);
3115 		break;
3116 #endif
3117 #ifdef INET6
3118 	case AF_INET6:
3119 		sai6 = (const struct sockaddr_in6 *)sa;
3120 		error = prison_check_ip6(cred, &sai6->sin6_addr);
3121 		break;
3122 #endif
3123 	default:
3124 		if (!(cred->cr_prison->pr_allow & PR_ALLOW_SOCKET_AF))
3125 			error = EAFNOSUPPORT;
3126 	}
3127 	return (error);
3128 }
3129 
3130 /*
3131  * Return 0 if jails permit p1 to frob p2, otherwise ESRCH.
3132  */
3133 int
3134 prison_check(struct ucred *cred1, struct ucred *cred2)
3135 {
3136 
3137 	return ((cred1->cr_prison == cred2->cr_prison ||
3138 	    prison_ischild(cred1->cr_prison, cred2->cr_prison)) ? 0 : ESRCH);
3139 }
3140 
3141 /*
3142  * Return 1 if p2 is a child of p1, otherwise 0.
3143  */
3144 int
3145 prison_ischild(struct prison *pr1, struct prison *pr2)
3146 {
3147 
3148 	for (pr2 = pr2->pr_parent; pr2 != NULL; pr2 = pr2->pr_parent)
3149 		if (pr1 == pr2)
3150 			return (1);
3151 	return (0);
3152 }
3153 
3154 /*
3155  * Return true if the prison is currently alive.  A prison is alive if it
3156  * holds user references and it isn't being removed.
3157  */
3158 bool
3159 prison_isalive(struct prison *pr)
3160 {
3161 
3162 	if (__predict_false(pr->pr_state != PRISON_STATE_ALIVE))
3163 		return (false);
3164 	return (true);
3165 }
3166 
3167 /*
3168  * Return true if the prison is currently valid.  A prison is valid if it has
3169  * been fully created, and is not being destroyed.  Note that dying prisons
3170  * are still considered valid.  Invalid prisons won't be found under normal
3171  * circumstances, as they're only put in that state by functions that have
3172  * an exclusive hold on allprison_lock.
3173  */
3174 bool
3175 prison_isvalid(struct prison *pr)
3176 {
3177 
3178 	if (__predict_false(pr->pr_state == PRISON_STATE_INVALID))
3179 		return (false);
3180 	if (__predict_false(refcount_load(&pr->pr_ref) == 0))
3181 		return (false);
3182 	return (true);
3183 }
3184 
3185 /*
3186  * Return 1 if the passed credential is in a jail and that jail does not
3187  * have its own virtual network stack, otherwise 0.
3188  */
3189 int
3190 jailed_without_vnet(struct ucred *cred)
3191 {
3192 
3193 	if (!jailed(cred))
3194 		return (0);
3195 #ifdef VIMAGE
3196 	if (prison_owns_vnet(cred))
3197 		return (0);
3198 #endif
3199 
3200 	return (1);
3201 }
3202 
3203 /*
3204  * Return the correct hostname (domainname, et al) for the passed credential.
3205  */
3206 void
3207 getcredhostname(struct ucred *cred, char *buf, size_t size)
3208 {
3209 	struct prison *pr;
3210 
3211 	/*
3212 	 * A NULL credential can be used to shortcut to the physical
3213 	 * system's hostname.
3214 	 */
3215 	pr = (cred != NULL) ? cred->cr_prison : &prison0;
3216 	mtx_lock(&pr->pr_mtx);
3217 	strlcpy(buf, pr->pr_hostname, size);
3218 	mtx_unlock(&pr->pr_mtx);
3219 }
3220 
3221 void
3222 getcreddomainname(struct ucred *cred, char *buf, size_t size)
3223 {
3224 
3225 	mtx_lock(&cred->cr_prison->pr_mtx);
3226 	strlcpy(buf, cred->cr_prison->pr_domainname, size);
3227 	mtx_unlock(&cred->cr_prison->pr_mtx);
3228 }
3229 
3230 void
3231 getcredhostuuid(struct ucred *cred, char *buf, size_t size)
3232 {
3233 
3234 	mtx_lock(&cred->cr_prison->pr_mtx);
3235 	strlcpy(buf, cred->cr_prison->pr_hostuuid, size);
3236 	mtx_unlock(&cred->cr_prison->pr_mtx);
3237 }
3238 
3239 void
3240 getcredhostid(struct ucred *cred, unsigned long *hostid)
3241 {
3242 
3243 	mtx_lock(&cred->cr_prison->pr_mtx);
3244 	*hostid = cred->cr_prison->pr_hostid;
3245 	mtx_unlock(&cred->cr_prison->pr_mtx);
3246 }
3247 
3248 void
3249 getjailname(struct ucred *cred, char *name, size_t len)
3250 {
3251 
3252 	mtx_lock(&cred->cr_prison->pr_mtx);
3253 	strlcpy(name, cred->cr_prison->pr_name, len);
3254 	mtx_unlock(&cred->cr_prison->pr_mtx);
3255 }
3256 
3257 #ifdef VIMAGE
3258 /*
3259  * Determine whether the prison represented by cred owns
3260  * its vnet rather than having it inherited.
3261  *
3262  * Returns 1 in case the prison owns the vnet, 0 otherwise.
3263  */
3264 int
3265 prison_owns_vnet(struct ucred *cred)
3266 {
3267 
3268 	/*
3269 	 * vnets cannot be added/removed after jail creation,
3270 	 * so no need to lock here.
3271 	 */
3272 	return (cred->cr_prison->pr_flags & PR_VNET ? 1 : 0);
3273 }
3274 #endif
3275 
3276 /*
3277  * Determine whether the subject represented by cred can "see"
3278  * status of a mount point.
3279  * Returns: 0 for permitted, ENOENT otherwise.
3280  * XXX: This function should be called cr_canseemount() and should be
3281  *      placed in kern_prot.c.
3282  */
3283 int
3284 prison_canseemount(struct ucred *cred, struct mount *mp)
3285 {
3286 	struct prison *pr;
3287 	struct statfs *sp;
3288 	size_t len;
3289 
3290 	pr = cred->cr_prison;
3291 	if (pr->pr_enforce_statfs == 0)
3292 		return (0);
3293 	if (pr->pr_root->v_mount == mp)
3294 		return (0);
3295 	if (pr->pr_enforce_statfs == 2)
3296 		return (ENOENT);
3297 	/*
3298 	 * If jail's chroot directory is set to "/" we should be able to see
3299 	 * all mount-points from inside a jail.
3300 	 * This is ugly check, but this is the only situation when jail's
3301 	 * directory ends with '/'.
3302 	 */
3303 	if (strcmp(pr->pr_path, "/") == 0)
3304 		return (0);
3305 	len = strlen(pr->pr_path);
3306 	sp = &mp->mnt_stat;
3307 	if (strncmp(pr->pr_path, sp->f_mntonname, len) != 0)
3308 		return (ENOENT);
3309 	/*
3310 	 * Be sure that we don't have situation where jail's root directory
3311 	 * is "/some/path" and mount point is "/some/pathpath".
3312 	 */
3313 	if (sp->f_mntonname[len] != '\0' && sp->f_mntonname[len] != '/')
3314 		return (ENOENT);
3315 	return (0);
3316 }
3317 
3318 void
3319 prison_enforce_statfs(struct ucred *cred, struct mount *mp, struct statfs *sp)
3320 {
3321 	char jpath[MAXPATHLEN];
3322 	struct prison *pr;
3323 	size_t len;
3324 
3325 	pr = cred->cr_prison;
3326 	if (pr->pr_enforce_statfs == 0)
3327 		return;
3328 	if (prison_canseemount(cred, mp) != 0) {
3329 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3330 		strlcpy(sp->f_mntonname, "[restricted]",
3331 		    sizeof(sp->f_mntonname));
3332 		return;
3333 	}
3334 	if (pr->pr_root->v_mount == mp) {
3335 		/*
3336 		 * Clear current buffer data, so we are sure nothing from
3337 		 * the valid path left there.
3338 		 */
3339 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3340 		*sp->f_mntonname = '/';
3341 		return;
3342 	}
3343 	/*
3344 	 * If jail's chroot directory is set to "/" we should be able to see
3345 	 * all mount-points from inside a jail.
3346 	 */
3347 	if (strcmp(pr->pr_path, "/") == 0)
3348 		return;
3349 	len = strlen(pr->pr_path);
3350 	strlcpy(jpath, sp->f_mntonname + len, sizeof(jpath));
3351 	/*
3352 	 * Clear current buffer data, so we are sure nothing from
3353 	 * the valid path left there.
3354 	 */
3355 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3356 	if (*jpath == '\0') {
3357 		/* Should never happen. */
3358 		*sp->f_mntonname = '/';
3359 	} else {
3360 		strlcpy(sp->f_mntonname, jpath, sizeof(sp->f_mntonname));
3361 	}
3362 }
3363 
3364 /*
3365  * Check with permission for a specific privilege is granted within jail.  We
3366  * have a specific list of accepted privileges; the rest are denied.
3367  */
3368 int
3369 prison_priv_check(struct ucred *cred, int priv)
3370 {
3371 	struct prison *pr;
3372 	int error;
3373 
3374 	/*
3375 	 * Some policies have custom handlers. This routine should not be
3376 	 * called for them. See priv_check_cred().
3377 	 */
3378 	switch (priv) {
3379 	case PRIV_VFS_LOOKUP:
3380 	case PRIV_VFS_GENERATION:
3381 		KASSERT(0, ("prison_priv_check instead of a custom handler "
3382 		    "called for %d\n", priv));
3383 	}
3384 
3385 	if (!jailed(cred))
3386 		return (0);
3387 
3388 #ifdef VIMAGE
3389 	/*
3390 	 * Privileges specific to prisons with a virtual network stack.
3391 	 * There might be a duplicate entry here in case the privilege
3392 	 * is only granted conditionally in the legacy jail case.
3393 	 */
3394 	switch (priv) {
3395 #ifdef notyet
3396 		/*
3397 		 * NFS-specific privileges.
3398 		 */
3399 	case PRIV_NFS_DAEMON:
3400 	case PRIV_NFS_LOCKD:
3401 #endif
3402 		/*
3403 		 * Network stack privileges.
3404 		 */
3405 	case PRIV_NET_BRIDGE:
3406 	case PRIV_NET_GRE:
3407 	case PRIV_NET_BPF:
3408 	case PRIV_NET_RAW:		/* Dup, cond. in legacy jail case. */
3409 	case PRIV_NET_ROUTE:
3410 	case PRIV_NET_TAP:
3411 	case PRIV_NET_SETIFMTU:
3412 	case PRIV_NET_SETIFFLAGS:
3413 	case PRIV_NET_SETIFCAP:
3414 	case PRIV_NET_SETIFDESCR:
3415 	case PRIV_NET_SETIFNAME	:
3416 	case PRIV_NET_SETIFMETRIC:
3417 	case PRIV_NET_SETIFPHYS:
3418 	case PRIV_NET_SETIFMAC:
3419 	case PRIV_NET_SETLANPCP:
3420 	case PRIV_NET_ADDMULTI:
3421 	case PRIV_NET_DELMULTI:
3422 	case PRIV_NET_HWIOCTL:
3423 	case PRIV_NET_SETLLADDR:
3424 	case PRIV_NET_ADDIFGROUP:
3425 	case PRIV_NET_DELIFGROUP:
3426 	case PRIV_NET_IFCREATE:
3427 	case PRIV_NET_IFDESTROY:
3428 	case PRIV_NET_ADDIFADDR:
3429 	case PRIV_NET_DELIFADDR:
3430 	case PRIV_NET_LAGG:
3431 	case PRIV_NET_GIF:
3432 	case PRIV_NET_SETIFVNET:
3433 	case PRIV_NET_SETIFFIB:
3434 
3435 		/*
3436 		 * 802.11-related privileges.
3437 		 */
3438 	case PRIV_NET80211_VAP_GETKEY:
3439 	case PRIV_NET80211_VAP_MANAGE:
3440 
3441 #ifdef notyet
3442 		/*
3443 		 * ATM privileges.
3444 		 */
3445 	case PRIV_NETATM_CFG:
3446 	case PRIV_NETATM_ADD:
3447 	case PRIV_NETATM_DEL:
3448 	case PRIV_NETATM_SET:
3449 
3450 		/*
3451 		 * Bluetooth privileges.
3452 		 */
3453 	case PRIV_NETBLUETOOTH_RAW:
3454 #endif
3455 
3456 		/*
3457 		 * Netgraph and netgraph module privileges.
3458 		 */
3459 	case PRIV_NETGRAPH_CONTROL:
3460 #ifdef notyet
3461 	case PRIV_NETGRAPH_TTY:
3462 #endif
3463 
3464 		/*
3465 		 * IPv4 and IPv6 privileges.
3466 		 */
3467 	case PRIV_NETINET_IPFW:
3468 	case PRIV_NETINET_DIVERT:
3469 	case PRIV_NETINET_PF:
3470 	case PRIV_NETINET_DUMMYNET:
3471 	case PRIV_NETINET_CARP:
3472 	case PRIV_NETINET_MROUTE:
3473 	case PRIV_NETINET_RAW:
3474 	case PRIV_NETINET_ADDRCTRL6:
3475 	case PRIV_NETINET_ND6:
3476 	case PRIV_NETINET_SCOPE6:
3477 	case PRIV_NETINET_ALIFETIME6:
3478 	case PRIV_NETINET_IPSEC:
3479 	case PRIV_NETINET_BINDANY:
3480 
3481 #ifdef notyet
3482 		/*
3483 		 * NCP privileges.
3484 		 */
3485 	case PRIV_NETNCP:
3486 
3487 		/*
3488 		 * SMB privileges.
3489 		 */
3490 	case PRIV_NETSMB:
3491 #endif
3492 
3493 	/*
3494 	 * No default: or deny here.
3495 	 * In case of no permit fall through to next switch().
3496 	 */
3497 		if (cred->cr_prison->pr_flags & PR_VNET)
3498 			return (0);
3499 	}
3500 #endif /* VIMAGE */
3501 
3502 	switch (priv) {
3503 		/*
3504 		 * Allow ktrace privileges for root in jail.
3505 		 */
3506 	case PRIV_KTRACE:
3507 
3508 #if 0
3509 		/*
3510 		 * Allow jailed processes to configure audit identity and
3511 		 * submit audit records (login, etc).  In the future we may
3512 		 * want to further refine the relationship between audit and
3513 		 * jail.
3514 		 */
3515 	case PRIV_AUDIT_GETAUDIT:
3516 	case PRIV_AUDIT_SETAUDIT:
3517 	case PRIV_AUDIT_SUBMIT:
3518 #endif
3519 
3520 		/*
3521 		 * Allow jailed processes to manipulate process UNIX
3522 		 * credentials in any way they see fit.
3523 		 */
3524 	case PRIV_CRED_SETUID:
3525 	case PRIV_CRED_SETEUID:
3526 	case PRIV_CRED_SETGID:
3527 	case PRIV_CRED_SETEGID:
3528 	case PRIV_CRED_SETGROUPS:
3529 	case PRIV_CRED_SETREUID:
3530 	case PRIV_CRED_SETREGID:
3531 	case PRIV_CRED_SETRESUID:
3532 	case PRIV_CRED_SETRESGID:
3533 
3534 		/*
3535 		 * Jail implements visibility constraints already, so allow
3536 		 * jailed root to override uid/gid-based constraints.
3537 		 */
3538 	case PRIV_SEEOTHERGIDS:
3539 	case PRIV_SEEOTHERUIDS:
3540 
3541 		/*
3542 		 * Jail implements inter-process debugging limits already, so
3543 		 * allow jailed root various debugging privileges.
3544 		 */
3545 	case PRIV_DEBUG_DIFFCRED:
3546 	case PRIV_DEBUG_SUGID:
3547 	case PRIV_DEBUG_UNPRIV:
3548 
3549 		/*
3550 		 * Allow jail to set various resource limits and login
3551 		 * properties, and for now, exceed process resource limits.
3552 		 */
3553 	case PRIV_PROC_LIMIT:
3554 	case PRIV_PROC_SETLOGIN:
3555 	case PRIV_PROC_SETRLIMIT:
3556 
3557 		/*
3558 		 * System V and POSIX IPC privileges are granted in jail.
3559 		 */
3560 	case PRIV_IPC_READ:
3561 	case PRIV_IPC_WRITE:
3562 	case PRIV_IPC_ADMIN:
3563 	case PRIV_IPC_MSGSIZE:
3564 	case PRIV_MQ_ADMIN:
3565 
3566 		/*
3567 		 * Jail operations within a jail work on child jails.
3568 		 */
3569 	case PRIV_JAIL_ATTACH:
3570 	case PRIV_JAIL_SET:
3571 	case PRIV_JAIL_REMOVE:
3572 
3573 		/*
3574 		 * Jail implements its own inter-process limits, so allow
3575 		 * root processes in jail to change scheduling on other
3576 		 * processes in the same jail.  Likewise for signalling.
3577 		 */
3578 	case PRIV_SCHED_DIFFCRED:
3579 	case PRIV_SCHED_CPUSET:
3580 	case PRIV_SIGNAL_DIFFCRED:
3581 	case PRIV_SIGNAL_SUGID:
3582 
3583 		/*
3584 		 * Allow jailed processes to write to sysctls marked as jail
3585 		 * writable.
3586 		 */
3587 	case PRIV_SYSCTL_WRITEJAIL:
3588 
3589 		/*
3590 		 * Allow root in jail to manage a variety of quota
3591 		 * properties.  These should likely be conditional on a
3592 		 * configuration option.
3593 		 */
3594 	case PRIV_VFS_GETQUOTA:
3595 	case PRIV_VFS_SETQUOTA:
3596 
3597 		/*
3598 		 * Since Jail relies on chroot() to implement file system
3599 		 * protections, grant many VFS privileges to root in jail.
3600 		 * Be careful to exclude mount-related and NFS-related
3601 		 * privileges.
3602 		 */
3603 	case PRIV_VFS_READ:
3604 	case PRIV_VFS_WRITE:
3605 	case PRIV_VFS_ADMIN:
3606 	case PRIV_VFS_EXEC:
3607 	case PRIV_VFS_BLOCKRESERVE:	/* XXXRW: Slightly surprising. */
3608 	case PRIV_VFS_CHFLAGS_DEV:
3609 	case PRIV_VFS_CHOWN:
3610 	case PRIV_VFS_CHROOT:
3611 	case PRIV_VFS_RETAINSUGID:
3612 	case PRIV_VFS_FCHROOT:
3613 	case PRIV_VFS_LINK:
3614 	case PRIV_VFS_SETGID:
3615 	case PRIV_VFS_STAT:
3616 	case PRIV_VFS_STICKYFILE:
3617 
3618 		/*
3619 		 * As in the non-jail case, non-root users are expected to be
3620 		 * able to read kernel/physical memory (provided /dev/[k]mem
3621 		 * exists in the jail and they have permission to access it).
3622 		 */
3623 	case PRIV_KMEM_READ:
3624 		return (0);
3625 
3626 		/*
3627 		 * Depending on the global setting, allow privilege of
3628 		 * setting system flags.
3629 		 */
3630 	case PRIV_VFS_SYSFLAGS:
3631 		if (cred->cr_prison->pr_allow & PR_ALLOW_CHFLAGS)
3632 			return (0);
3633 		else
3634 			return (EPERM);
3635 
3636 		/*
3637 		 * Depending on the global setting, allow privilege of
3638 		 * mounting/unmounting file systems.
3639 		 */
3640 	case PRIV_VFS_MOUNT:
3641 	case PRIV_VFS_UNMOUNT:
3642 	case PRIV_VFS_MOUNT_NONUSER:
3643 	case PRIV_VFS_MOUNT_OWNER:
3644 		pr = cred->cr_prison;
3645 		prison_lock(pr);
3646 		if (pr->pr_allow & PR_ALLOW_MOUNT && pr->pr_enforce_statfs < 2)
3647 			error = 0;
3648 		else
3649 			error = EPERM;
3650 		prison_unlock(pr);
3651 		return (error);
3652 
3653 		/*
3654 		 * Jails should hold no disposition on the PRIV_VFS_READ_DIR
3655 		 * policy.  priv_check_cred will not specifically allow it, and
3656 		 * we may want a MAC policy to allow it.
3657 		 */
3658 	case PRIV_VFS_READ_DIR:
3659 		return (0);
3660 
3661 		/*
3662 		 * Conditionnaly allow locking (unlocking) physical pages
3663 		 * in memory.
3664 		 */
3665 	case PRIV_VM_MLOCK:
3666 	case PRIV_VM_MUNLOCK:
3667 		if (cred->cr_prison->pr_allow & PR_ALLOW_MLOCK)
3668 			return (0);
3669 		else
3670 			return (EPERM);
3671 
3672 		/*
3673 		 * Conditionally allow jailed root to bind reserved ports.
3674 		 */
3675 	case PRIV_NETINET_RESERVEDPORT:
3676 		if (cred->cr_prison->pr_allow & PR_ALLOW_RESERVED_PORTS)
3677 			return (0);
3678 		else
3679 			return (EPERM);
3680 
3681 		/*
3682 		 * Allow jailed root to reuse in-use ports.
3683 		 */
3684 	case PRIV_NETINET_REUSEPORT:
3685 		return (0);
3686 
3687 		/*
3688 		 * Allow jailed root to set certain IPv4/6 (option) headers.
3689 		 */
3690 	case PRIV_NETINET_SETHDROPTS:
3691 		return (0);
3692 
3693 		/*
3694 		 * Conditionally allow creating raw sockets in jail.
3695 		 */
3696 	case PRIV_NETINET_RAW:
3697 		if (cred->cr_prison->pr_allow & PR_ALLOW_RAW_SOCKETS)
3698 			return (0);
3699 		else
3700 			return (EPERM);
3701 
3702 		/*
3703 		 * Since jail implements its own visibility limits on netstat
3704 		 * sysctls, allow getcred.  This allows identd to work in
3705 		 * jail.
3706 		 */
3707 	case PRIV_NETINET_GETCRED:
3708 		return (0);
3709 
3710 		/*
3711 		 * Allow jailed root to set loginclass.
3712 		 */
3713 	case PRIV_PROC_SETLOGINCLASS:
3714 		return (0);
3715 
3716 		/*
3717 		 * Do not allow a process inside a jail to read the kernel
3718 		 * message buffer unless explicitly permitted.
3719 		 */
3720 	case PRIV_MSGBUF:
3721 		if (cred->cr_prison->pr_allow & PR_ALLOW_READ_MSGBUF)
3722 			return (0);
3723 		return (EPERM);
3724 
3725 	default:
3726 		/*
3727 		 * In all remaining cases, deny the privilege request.  This
3728 		 * includes almost all network privileges, many system
3729 		 * configuration privileges.
3730 		 */
3731 		return (EPERM);
3732 	}
3733 }
3734 
3735 /*
3736  * Return the part of pr2's name that is relative to pr1, or the whole name
3737  * if it does not directly follow.
3738  */
3739 
3740 char *
3741 prison_name(struct prison *pr1, struct prison *pr2)
3742 {
3743 	char *name;
3744 
3745 	/* Jails see themselves as "0" (if they see themselves at all). */
3746 	if (pr1 == pr2)
3747 		return "0";
3748 	name = pr2->pr_name;
3749 	if (prison_ischild(pr1, pr2)) {
3750 		/*
3751 		 * pr1 isn't locked (and allprison_lock may not be either)
3752 		 * so its length can't be counted on.  But the number of dots
3753 		 * can be counted on - and counted.
3754 		 */
3755 		for (; pr1 != &prison0; pr1 = pr1->pr_parent)
3756 			name = strchr(name, '.') + 1;
3757 	}
3758 	return (name);
3759 }
3760 
3761 /*
3762  * Return the part of pr2's path that is relative to pr1, or the whole path
3763  * if it does not directly follow.
3764  */
3765 static char *
3766 prison_path(struct prison *pr1, struct prison *pr2)
3767 {
3768 	char *path1, *path2;
3769 	int len1;
3770 
3771 	path1 = pr1->pr_path;
3772 	path2 = pr2->pr_path;
3773 	if (!strcmp(path1, "/"))
3774 		return (path2);
3775 	len1 = strlen(path1);
3776 	if (strncmp(path1, path2, len1))
3777 		return (path2);
3778 	if (path2[len1] == '\0')
3779 		return "/";
3780 	if (path2[len1] == '/')
3781 		return (path2 + len1);
3782 	return (path2);
3783 }
3784 
3785 /*
3786  * Jail-related sysctls.
3787  */
3788 static SYSCTL_NODE(_security, OID_AUTO, jail, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
3789     "Jails");
3790 
3791 static int
3792 sysctl_jail_list(SYSCTL_HANDLER_ARGS)
3793 {
3794 	struct xprison *xp;
3795 	struct prison *pr, *cpr;
3796 #ifdef INET
3797 	struct in_addr *ip4 = NULL;
3798 	int ip4s = 0;
3799 #endif
3800 #ifdef INET6
3801 	struct in6_addr *ip6 = NULL;
3802 	int ip6s = 0;
3803 #endif
3804 	int descend, error;
3805 
3806 	xp = malloc(sizeof(*xp), M_TEMP, M_WAITOK);
3807 	pr = req->td->td_ucred->cr_prison;
3808 	error = 0;
3809 	sx_slock(&allprison_lock);
3810 	FOREACH_PRISON_DESCENDANT(pr, cpr, descend) {
3811 #if defined(INET) || defined(INET6)
3812  again:
3813 #endif
3814 		mtx_lock(&cpr->pr_mtx);
3815 #ifdef INET
3816 		if (cpr->pr_ip4s > 0) {
3817 			if (ip4s < cpr->pr_ip4s) {
3818 				ip4s = cpr->pr_ip4s;
3819 				mtx_unlock(&cpr->pr_mtx);
3820 				ip4 = realloc(ip4, ip4s *
3821 				    sizeof(struct in_addr), M_TEMP, M_WAITOK);
3822 				goto again;
3823 			}
3824 			bcopy(cpr->pr_ip4, ip4,
3825 			    cpr->pr_ip4s * sizeof(struct in_addr));
3826 		}
3827 #endif
3828 #ifdef INET6
3829 		if (cpr->pr_ip6s > 0) {
3830 			if (ip6s < cpr->pr_ip6s) {
3831 				ip6s = cpr->pr_ip6s;
3832 				mtx_unlock(&cpr->pr_mtx);
3833 				ip6 = realloc(ip6, ip6s *
3834 				    sizeof(struct in6_addr), M_TEMP, M_WAITOK);
3835 				goto again;
3836 			}
3837 			bcopy(cpr->pr_ip6, ip6,
3838 			    cpr->pr_ip6s * sizeof(struct in6_addr));
3839 		}
3840 #endif
3841 		bzero(xp, sizeof(*xp));
3842 		xp->pr_version = XPRISON_VERSION;
3843 		xp->pr_id = cpr->pr_id;
3844 		xp->pr_state = cpr->pr_state;
3845 		strlcpy(xp->pr_path, prison_path(pr, cpr), sizeof(xp->pr_path));
3846 		strlcpy(xp->pr_host, cpr->pr_hostname, sizeof(xp->pr_host));
3847 		strlcpy(xp->pr_name, prison_name(pr, cpr), sizeof(xp->pr_name));
3848 #ifdef INET
3849 		xp->pr_ip4s = cpr->pr_ip4s;
3850 #endif
3851 #ifdef INET6
3852 		xp->pr_ip6s = cpr->pr_ip6s;
3853 #endif
3854 		mtx_unlock(&cpr->pr_mtx);
3855 		error = SYSCTL_OUT(req, xp, sizeof(*xp));
3856 		if (error)
3857 			break;
3858 #ifdef INET
3859 		if (xp->pr_ip4s > 0) {
3860 			error = SYSCTL_OUT(req, ip4,
3861 			    xp->pr_ip4s * sizeof(struct in_addr));
3862 			if (error)
3863 				break;
3864 		}
3865 #endif
3866 #ifdef INET6
3867 		if (xp->pr_ip6s > 0) {
3868 			error = SYSCTL_OUT(req, ip6,
3869 			    xp->pr_ip6s * sizeof(struct in6_addr));
3870 			if (error)
3871 				break;
3872 		}
3873 #endif
3874 	}
3875 	sx_sunlock(&allprison_lock);
3876 	free(xp, M_TEMP);
3877 #ifdef INET
3878 	free(ip4, M_TEMP);
3879 #endif
3880 #ifdef INET6
3881 	free(ip6, M_TEMP);
3882 #endif
3883 	return (error);
3884 }
3885 
3886 SYSCTL_OID(_security_jail, OID_AUTO, list,
3887     CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
3888     sysctl_jail_list, "S", "List of active jails");
3889 
3890 static int
3891 sysctl_jail_jailed(SYSCTL_HANDLER_ARGS)
3892 {
3893 	int error, injail;
3894 
3895 	injail = jailed(req->td->td_ucred);
3896 	error = SYSCTL_OUT(req, &injail, sizeof(injail));
3897 
3898 	return (error);
3899 }
3900 
3901 SYSCTL_PROC(_security_jail, OID_AUTO, jailed,
3902     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
3903     sysctl_jail_jailed, "I", "Process in jail?");
3904 
3905 static int
3906 sysctl_jail_vnet(SYSCTL_HANDLER_ARGS)
3907 {
3908 	int error, havevnet;
3909 #ifdef VIMAGE
3910 	struct ucred *cred = req->td->td_ucred;
3911 
3912 	havevnet = jailed(cred) && prison_owns_vnet(cred);
3913 #else
3914 	havevnet = 0;
3915 #endif
3916 	error = SYSCTL_OUT(req, &havevnet, sizeof(havevnet));
3917 
3918 	return (error);
3919 }
3920 
3921 SYSCTL_PROC(_security_jail, OID_AUTO, vnet,
3922     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
3923     sysctl_jail_vnet, "I", "Jail owns vnet?");
3924 
3925 #if defined(INET) || defined(INET6)
3926 SYSCTL_UINT(_security_jail, OID_AUTO, jail_max_af_ips, CTLFLAG_RW,
3927     &jail_max_af_ips, 0,
3928     "Number of IP addresses a jail may have at most per address family (deprecated)");
3929 #endif
3930 
3931 /*
3932  * Default parameters for jail(2) compatibility.  For historical reasons,
3933  * the sysctl names have varying similarity to the parameter names.  Prisons
3934  * just see their own parameters, and can't change them.
3935  */
3936 static int
3937 sysctl_jail_default_allow(SYSCTL_HANDLER_ARGS)
3938 {
3939 	int error, i;
3940 
3941 	/* Get the current flag value, and convert it to a boolean. */
3942 	if (req->td->td_ucred->cr_prison == &prison0) {
3943 		mtx_lock(&prison0.pr_mtx);
3944 		i = (jail_default_allow & arg2) != 0;
3945 		mtx_unlock(&prison0.pr_mtx);
3946 	} else
3947 		i = prison_allow(req->td->td_ucred, arg2);
3948 
3949 	if (arg1 != NULL)
3950 		i = !i;
3951 	error = sysctl_handle_int(oidp, &i, 0, req);
3952 	if (error || !req->newptr)
3953 		return (error);
3954 	i = i ? arg2 : 0;
3955 	if (arg1 != NULL)
3956 		i ^= arg2;
3957 	/*
3958 	 * The sysctls don't have CTLFLAGS_PRISON, so assume prison0
3959 	 * for writing.
3960 	 */
3961 	mtx_lock(&prison0.pr_mtx);
3962 	jail_default_allow = (jail_default_allow & ~arg2) | i;
3963 	mtx_unlock(&prison0.pr_mtx);
3964 	return (0);
3965 }
3966 
3967 SYSCTL_PROC(_security_jail, OID_AUTO, set_hostname_allowed,
3968     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3969     NULL, PR_ALLOW_SET_HOSTNAME, sysctl_jail_default_allow, "I",
3970     "Processes in jail can set their hostnames (deprecated)");
3971 SYSCTL_PROC(_security_jail, OID_AUTO, socket_unixiproute_only,
3972     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3973     (void *)1, PR_ALLOW_SOCKET_AF, sysctl_jail_default_allow, "I",
3974     "Processes in jail are limited to creating UNIX/IP/route sockets only (deprecated)");
3975 SYSCTL_PROC(_security_jail, OID_AUTO, sysvipc_allowed,
3976     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3977     NULL, PR_ALLOW_SYSVIPC, sysctl_jail_default_allow, "I",
3978     "Processes in jail can use System V IPC primitives (deprecated)");
3979 SYSCTL_PROC(_security_jail, OID_AUTO, allow_raw_sockets,
3980     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3981     NULL, PR_ALLOW_RAW_SOCKETS, sysctl_jail_default_allow, "I",
3982     "Prison root can create raw sockets (deprecated)");
3983 SYSCTL_PROC(_security_jail, OID_AUTO, chflags_allowed,
3984     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3985     NULL, PR_ALLOW_CHFLAGS, sysctl_jail_default_allow, "I",
3986     "Processes in jail can alter system file flags (deprecated)");
3987 SYSCTL_PROC(_security_jail, OID_AUTO, mount_allowed,
3988     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3989     NULL, PR_ALLOW_MOUNT, sysctl_jail_default_allow, "I",
3990     "Processes in jail can mount/unmount jail-friendly file systems (deprecated)");
3991 
3992 static int
3993 sysctl_jail_default_level(SYSCTL_HANDLER_ARGS)
3994 {
3995 	struct prison *pr;
3996 	int level, error;
3997 
3998 	pr = req->td->td_ucred->cr_prison;
3999 	level = (pr == &prison0) ? *(int *)arg1 : *(int *)((char *)pr + arg2);
4000 	error = sysctl_handle_int(oidp, &level, 0, req);
4001 	if (error || !req->newptr)
4002 		return (error);
4003 	*(int *)arg1 = level;
4004 	return (0);
4005 }
4006 
4007 SYSCTL_PROC(_security_jail, OID_AUTO, enforce_statfs,
4008     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4009     &jail_default_enforce_statfs, offsetof(struct prison, pr_enforce_statfs),
4010     sysctl_jail_default_level, "I",
4011     "Processes in jail cannot see all mounted file systems (deprecated)");
4012 
4013 SYSCTL_PROC(_security_jail, OID_AUTO, devfs_ruleset,
4014     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
4015     &jail_default_devfs_rsnum, offsetof(struct prison, pr_devfs_rsnum),
4016     sysctl_jail_default_level, "I",
4017     "Ruleset for the devfs filesystem in jail (deprecated)");
4018 
4019 /*
4020  * Nodes to describe jail parameters.  Maximum length of string parameters
4021  * is returned in the string itself, and the other parameters exist merely
4022  * to make themselves and their types known.
4023  */
4024 SYSCTL_NODE(_security_jail, OID_AUTO, param, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
4025     "Jail parameters");
4026 
4027 int
4028 sysctl_jail_param(SYSCTL_HANDLER_ARGS)
4029 {
4030 	int i;
4031 	long l;
4032 	size_t s;
4033 	char numbuf[12];
4034 
4035 	switch (oidp->oid_kind & CTLTYPE)
4036 	{
4037 	case CTLTYPE_LONG:
4038 	case CTLTYPE_ULONG:
4039 		l = 0;
4040 #ifdef SCTL_MASK32
4041 		if (!(req->flags & SCTL_MASK32))
4042 #endif
4043 			return (SYSCTL_OUT(req, &l, sizeof(l)));
4044 	case CTLTYPE_INT:
4045 	case CTLTYPE_UINT:
4046 		i = 0;
4047 		return (SYSCTL_OUT(req, &i, sizeof(i)));
4048 	case CTLTYPE_STRING:
4049 		snprintf(numbuf, sizeof(numbuf), "%jd", (intmax_t)arg2);
4050 		return
4051 		    (sysctl_handle_string(oidp, numbuf, sizeof(numbuf), req));
4052 	case CTLTYPE_STRUCT:
4053 		s = (size_t)arg2;
4054 		return (SYSCTL_OUT(req, &s, sizeof(s)));
4055 	}
4056 	return (0);
4057 }
4058 
4059 /*
4060  * CTLFLAG_RDTUN in the following indicates jail parameters that can be set at
4061  * jail creation time but cannot be changed in an existing jail.
4062  */
4063 SYSCTL_JAIL_PARAM(, jid, CTLTYPE_INT | CTLFLAG_RDTUN, "I", "Jail ID");
4064 SYSCTL_JAIL_PARAM(, parent, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail parent ID");
4065 SYSCTL_JAIL_PARAM_STRING(, name, CTLFLAG_RW, MAXHOSTNAMELEN, "Jail name");
4066 SYSCTL_JAIL_PARAM_STRING(, path, CTLFLAG_RDTUN, MAXPATHLEN, "Jail root path");
4067 SYSCTL_JAIL_PARAM(, securelevel, CTLTYPE_INT | CTLFLAG_RW,
4068     "I", "Jail secure level");
4069 SYSCTL_JAIL_PARAM(, osreldate, CTLTYPE_INT | CTLFLAG_RDTUN, "I",
4070     "Jail value for kern.osreldate and uname -K");
4071 SYSCTL_JAIL_PARAM_STRING(, osrelease, CTLFLAG_RDTUN, OSRELEASELEN,
4072     "Jail value for kern.osrelease and uname -r");
4073 SYSCTL_JAIL_PARAM(, enforce_statfs, CTLTYPE_INT | CTLFLAG_RW,
4074     "I", "Jail cannot see all mounted file systems");
4075 SYSCTL_JAIL_PARAM(, devfs_ruleset, CTLTYPE_INT | CTLFLAG_RW,
4076     "I", "Ruleset for in-jail devfs mounts");
4077 SYSCTL_JAIL_PARAM(, persist, CTLTYPE_INT | CTLFLAG_RW,
4078     "B", "Jail persistence");
4079 #ifdef VIMAGE
4080 SYSCTL_JAIL_PARAM(, vnet, CTLTYPE_INT | CTLFLAG_RDTUN,
4081     "E,jailsys", "Virtual network stack");
4082 #endif
4083 SYSCTL_JAIL_PARAM(, dying, CTLTYPE_INT | CTLFLAG_RD,
4084     "B", "Jail is in the process of shutting down");
4085 
4086 SYSCTL_JAIL_PARAM_NODE(children, "Number of child jails");
4087 SYSCTL_JAIL_PARAM(_children, cur, CTLTYPE_INT | CTLFLAG_RD,
4088     "I", "Current number of child jails");
4089 SYSCTL_JAIL_PARAM(_children, max, CTLTYPE_INT | CTLFLAG_RW,
4090     "I", "Maximum number of child jails");
4091 
4092 SYSCTL_JAIL_PARAM_SYS_NODE(host, CTLFLAG_RW, "Jail host info");
4093 SYSCTL_JAIL_PARAM_STRING(_host, hostname, CTLFLAG_RW, MAXHOSTNAMELEN,
4094     "Jail hostname");
4095 SYSCTL_JAIL_PARAM_STRING(_host, domainname, CTLFLAG_RW, MAXHOSTNAMELEN,
4096     "Jail NIS domainname");
4097 SYSCTL_JAIL_PARAM_STRING(_host, hostuuid, CTLFLAG_RW, HOSTUUIDLEN,
4098     "Jail host UUID");
4099 SYSCTL_JAIL_PARAM(_host, hostid, CTLTYPE_ULONG | CTLFLAG_RW,
4100     "LU", "Jail host ID");
4101 
4102 SYSCTL_JAIL_PARAM_NODE(cpuset, "Jail cpuset");
4103 SYSCTL_JAIL_PARAM(_cpuset, id, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail cpuset ID");
4104 
4105 #ifdef INET
4106 SYSCTL_JAIL_PARAM_SYS_NODE(ip4, CTLFLAG_RDTUN,
4107     "Jail IPv4 address virtualization");
4108 SYSCTL_JAIL_PARAM_STRUCT(_ip4, addr, CTLFLAG_RW, sizeof(struct in_addr),
4109     "S,in_addr,a", "Jail IPv4 addresses");
4110 SYSCTL_JAIL_PARAM(_ip4, saddrsel, CTLTYPE_INT | CTLFLAG_RW,
4111     "B", "Do (not) use IPv4 source address selection rather than the "
4112     "primary jail IPv4 address.");
4113 #endif
4114 #ifdef INET6
4115 SYSCTL_JAIL_PARAM_SYS_NODE(ip6, CTLFLAG_RDTUN,
4116     "Jail IPv6 address virtualization");
4117 SYSCTL_JAIL_PARAM_STRUCT(_ip6, addr, CTLFLAG_RW, sizeof(struct in6_addr),
4118     "S,in6_addr,a", "Jail IPv6 addresses");
4119 SYSCTL_JAIL_PARAM(_ip6, saddrsel, CTLTYPE_INT | CTLFLAG_RW,
4120     "B", "Do (not) use IPv6 source address selection rather than the "
4121     "primary jail IPv6 address.");
4122 #endif
4123 
4124 SYSCTL_JAIL_PARAM_NODE(allow, "Jail permission flags");
4125 SYSCTL_JAIL_PARAM(_allow, set_hostname, CTLTYPE_INT | CTLFLAG_RW,
4126     "B", "Jail may set hostname");
4127 SYSCTL_JAIL_PARAM(_allow, sysvipc, CTLTYPE_INT | CTLFLAG_RW,
4128     "B", "Jail may use SYSV IPC");
4129 SYSCTL_JAIL_PARAM(_allow, raw_sockets, CTLTYPE_INT | CTLFLAG_RW,
4130     "B", "Jail may create raw sockets");
4131 SYSCTL_JAIL_PARAM(_allow, chflags, CTLTYPE_INT | CTLFLAG_RW,
4132     "B", "Jail may alter system file flags");
4133 SYSCTL_JAIL_PARAM(_allow, quotas, CTLTYPE_INT | CTLFLAG_RW,
4134     "B", "Jail may set file quotas");
4135 SYSCTL_JAIL_PARAM(_allow, socket_af, CTLTYPE_INT | CTLFLAG_RW,
4136     "B", "Jail may create sockets other than just UNIX/IPv4/IPv6/route");
4137 SYSCTL_JAIL_PARAM(_allow, mlock, CTLTYPE_INT | CTLFLAG_RW,
4138     "B", "Jail may lock (unlock) physical pages in memory");
4139 SYSCTL_JAIL_PARAM(_allow, reserved_ports, CTLTYPE_INT | CTLFLAG_RW,
4140     "B", "Jail may bind sockets to reserved ports");
4141 SYSCTL_JAIL_PARAM(_allow, read_msgbuf, CTLTYPE_INT | CTLFLAG_RW,
4142     "B", "Jail may read the kernel message buffer");
4143 SYSCTL_JAIL_PARAM(_allow, unprivileged_proc_debug, CTLTYPE_INT | CTLFLAG_RW,
4144     "B", "Unprivileged processes may use process debugging facilities");
4145 SYSCTL_JAIL_PARAM(_allow, suser, CTLTYPE_INT | CTLFLAG_RW,
4146     "B", "Processes in jail with uid 0 have privilege");
4147 
4148 SYSCTL_JAIL_PARAM_SUBNODE(allow, mount, "Jail mount/unmount permission flags");
4149 SYSCTL_JAIL_PARAM(_allow_mount, , CTLTYPE_INT | CTLFLAG_RW,
4150     "B", "Jail may mount/unmount jail-friendly file systems in general");
4151 
4152 /*
4153  * Add a dynamic parameter allow.<name>, or allow.<prefix>.<name>.  Return
4154  * its associated bit in the pr_allow bitmask, or zero if the parameter was
4155  * not created.
4156  */
4157 unsigned
4158 prison_add_allow(const char *prefix, const char *name, const char *prefix_descr,
4159     const char *descr)
4160 {
4161 	struct bool_flags *bf;
4162 	struct sysctl_oid *parent;
4163 	char *allow_name, *allow_noname, *allowed;
4164 #ifndef NO_SYSCTL_DESCR
4165 	char *descr_deprecated;
4166 #endif
4167 	u_int allow_flag;
4168 
4169 	if (prefix
4170 	    ? asprintf(&allow_name, M_PRISON, "allow.%s.%s", prefix, name)
4171 		< 0 ||
4172 	      asprintf(&allow_noname, M_PRISON, "allow.%s.no%s", prefix, name)
4173 		< 0
4174 	    : asprintf(&allow_name, M_PRISON, "allow.%s", name) < 0 ||
4175 	      asprintf(&allow_noname, M_PRISON, "allow.no%s", name) < 0) {
4176 		free(allow_name, M_PRISON);
4177 		return 0;
4178 	}
4179 
4180 	/*
4181 	 * See if this parameter has already beed added, i.e. a module was
4182 	 * previously loaded/unloaded.
4183 	 */
4184 	mtx_lock(&prison0.pr_mtx);
4185 	for (bf = pr_flag_allow;
4186 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
4187 		atomic_load_int(&bf->flag) != 0;
4188 	     bf++) {
4189 		if (strcmp(bf->name, allow_name) == 0) {
4190 			allow_flag = bf->flag;
4191 			goto no_add;
4192 		}
4193 	}
4194 
4195 	/*
4196 	 * Find a free bit in pr_allow_all, failing if there are none
4197 	 * (which shouldn't happen as long as we keep track of how many
4198 	 * potential dynamic flags exist).
4199 	 */
4200 	for (allow_flag = 1;; allow_flag <<= 1) {
4201 		if (allow_flag == 0)
4202 			goto no_add;
4203 		if ((pr_allow_all & allow_flag) == 0)
4204 			break;
4205 	}
4206 
4207 	/* Note the parameter in the next open slot in pr_flag_allow. */
4208 	for (bf = pr_flag_allow; ; bf++) {
4209 		if (bf == pr_flag_allow + nitems(pr_flag_allow)) {
4210 			/* This should never happen, but is not fatal. */
4211 			allow_flag = 0;
4212 			goto no_add;
4213 		}
4214 		if (atomic_load_int(&bf->flag) == 0)
4215 			break;
4216 	}
4217 	bf->name = allow_name;
4218 	bf->noname = allow_noname;
4219 	pr_allow_all |= allow_flag;
4220 	/*
4221 	 * prison0 always has permission for the new parameter.
4222 	 * Other jails must have it granted to them.
4223 	 */
4224 	prison0.pr_allow |= allow_flag;
4225 	/* The flag indicates a valid entry, so make sure it is set last. */
4226 	atomic_store_rel_int(&bf->flag, allow_flag);
4227 	mtx_unlock(&prison0.pr_mtx);
4228 
4229 	/*
4230 	 * Create sysctls for the paramter, and the back-compat global
4231 	 * permission.
4232 	 */
4233 	parent = prefix
4234 	    ? SYSCTL_ADD_NODE(NULL,
4235 		  SYSCTL_CHILDREN(&sysctl___security_jail_param_allow),
4236 		  OID_AUTO, prefix, CTLFLAG_MPSAFE, 0, prefix_descr)
4237 	    : &sysctl___security_jail_param_allow;
4238 	(void)SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(parent), OID_AUTO,
4239 	    name, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4240 	    NULL, 0, sysctl_jail_param, "B", descr);
4241 	if ((prefix
4242 	     ? asprintf(&allowed, M_TEMP, "%s_%s_allowed", prefix, name)
4243 	     : asprintf(&allowed, M_TEMP, "%s_allowed", name)) >= 0) {
4244 #ifndef NO_SYSCTL_DESCR
4245 		(void)asprintf(&descr_deprecated, M_TEMP, "%s (deprecated)",
4246 		    descr);
4247 #endif
4248 		(void)SYSCTL_ADD_PROC(NULL,
4249 		    SYSCTL_CHILDREN(&sysctl___security_jail), OID_AUTO, allowed,
4250 		    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, allow_flag,
4251 		    sysctl_jail_default_allow, "I", descr_deprecated);
4252 #ifndef NO_SYSCTL_DESCR
4253 		free(descr_deprecated, M_TEMP);
4254 #endif
4255 		free(allowed, M_TEMP);
4256 	}
4257 	return allow_flag;
4258 
4259  no_add:
4260 	mtx_unlock(&prison0.pr_mtx);
4261 	free(allow_name, M_PRISON);
4262 	free(allow_noname, M_PRISON);
4263 	return allow_flag;
4264 }
4265 
4266 /*
4267  * The VFS system will register jail-aware filesystems here.  They each get
4268  * a parameter allow.mount.xxxfs and a flag to check when a jailed user
4269  * attempts to mount.
4270  */
4271 void
4272 prison_add_vfs(struct vfsconf *vfsp)
4273 {
4274 #ifdef NO_SYSCTL_DESCR
4275 
4276 	vfsp->vfc_prison_flag = prison_add_allow("mount", vfsp->vfc_name,
4277 	    NULL, NULL);
4278 #else
4279 	char *descr;
4280 
4281 	(void)asprintf(&descr, M_TEMP, "Jail may mount the %s file system",
4282 	    vfsp->vfc_name);
4283 	vfsp->vfc_prison_flag = prison_add_allow("mount", vfsp->vfc_name,
4284 	    NULL, descr);
4285 	free(descr, M_TEMP);
4286 #endif
4287 }
4288 
4289 #ifdef RACCT
4290 void
4291 prison_racct_foreach(void (*callback)(struct racct *racct,
4292     void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
4293     void *arg2, void *arg3)
4294 {
4295 	struct prison_racct *prr;
4296 
4297 	ASSERT_RACCT_ENABLED();
4298 
4299 	sx_slock(&allprison_lock);
4300 	if (pre != NULL)
4301 		(pre)();
4302 	LIST_FOREACH(prr, &allprison_racct, prr_next)
4303 		(callback)(prr->prr_racct, arg2, arg3);
4304 	if (post != NULL)
4305 		(post)();
4306 	sx_sunlock(&allprison_lock);
4307 }
4308 
4309 static struct prison_racct *
4310 prison_racct_find_locked(const char *name)
4311 {
4312 	struct prison_racct *prr;
4313 
4314 	ASSERT_RACCT_ENABLED();
4315 	sx_assert(&allprison_lock, SA_XLOCKED);
4316 
4317 	if (name[0] == '\0' || strlen(name) >= MAXHOSTNAMELEN)
4318 		return (NULL);
4319 
4320 	LIST_FOREACH(prr, &allprison_racct, prr_next) {
4321 		if (strcmp(name, prr->prr_name) != 0)
4322 			continue;
4323 
4324 		/* Found prison_racct with a matching name? */
4325 		prison_racct_hold(prr);
4326 		return (prr);
4327 	}
4328 
4329 	/* Add new prison_racct. */
4330 	prr = malloc(sizeof(*prr), M_PRISON_RACCT, M_ZERO | M_WAITOK);
4331 	racct_create(&prr->prr_racct);
4332 
4333 	strcpy(prr->prr_name, name);
4334 	refcount_init(&prr->prr_refcount, 1);
4335 	LIST_INSERT_HEAD(&allprison_racct, prr, prr_next);
4336 
4337 	return (prr);
4338 }
4339 
4340 struct prison_racct *
4341 prison_racct_find(const char *name)
4342 {
4343 	struct prison_racct *prr;
4344 
4345 	ASSERT_RACCT_ENABLED();
4346 
4347 	sx_xlock(&allprison_lock);
4348 	prr = prison_racct_find_locked(name);
4349 	sx_xunlock(&allprison_lock);
4350 	return (prr);
4351 }
4352 
4353 void
4354 prison_racct_hold(struct prison_racct *prr)
4355 {
4356 
4357 	ASSERT_RACCT_ENABLED();
4358 
4359 	refcount_acquire(&prr->prr_refcount);
4360 }
4361 
4362 static void
4363 prison_racct_free_locked(struct prison_racct *prr)
4364 {
4365 
4366 	ASSERT_RACCT_ENABLED();
4367 	sx_assert(&allprison_lock, SA_XLOCKED);
4368 
4369 	if (refcount_release(&prr->prr_refcount)) {
4370 		racct_destroy(&prr->prr_racct);
4371 		LIST_REMOVE(prr, prr_next);
4372 		free(prr, M_PRISON_RACCT);
4373 	}
4374 }
4375 
4376 void
4377 prison_racct_free(struct prison_racct *prr)
4378 {
4379 
4380 	ASSERT_RACCT_ENABLED();
4381 	sx_assert(&allprison_lock, SA_UNLOCKED);
4382 
4383 	if (refcount_release_if_not_last(&prr->prr_refcount))
4384 		return;
4385 
4386 	sx_xlock(&allprison_lock);
4387 	prison_racct_free_locked(prr);
4388 	sx_xunlock(&allprison_lock);
4389 }
4390 
4391 static void
4392 prison_racct_attach(struct prison *pr)
4393 {
4394 	struct prison_racct *prr;
4395 
4396 	ASSERT_RACCT_ENABLED();
4397 	sx_assert(&allprison_lock, SA_XLOCKED);
4398 
4399 	prr = prison_racct_find_locked(pr->pr_name);
4400 	KASSERT(prr != NULL, ("cannot find prison_racct"));
4401 
4402 	pr->pr_prison_racct = prr;
4403 }
4404 
4405 /*
4406  * Handle jail renaming.  From the racct point of view, renaming means
4407  * moving from one prison_racct to another.
4408  */
4409 static void
4410 prison_racct_modify(struct prison *pr)
4411 {
4412 #ifdef RCTL
4413 	struct proc *p;
4414 	struct ucred *cred;
4415 #endif
4416 	struct prison_racct *oldprr;
4417 
4418 	ASSERT_RACCT_ENABLED();
4419 
4420 	sx_slock(&allproc_lock);
4421 	sx_xlock(&allprison_lock);
4422 
4423 	if (strcmp(pr->pr_name, pr->pr_prison_racct->prr_name) == 0) {
4424 		sx_xunlock(&allprison_lock);
4425 		sx_sunlock(&allproc_lock);
4426 		return;
4427 	}
4428 
4429 	oldprr = pr->pr_prison_racct;
4430 	pr->pr_prison_racct = NULL;
4431 
4432 	prison_racct_attach(pr);
4433 
4434 	/*
4435 	 * Move resource utilisation records.
4436 	 */
4437 	racct_move(pr->pr_prison_racct->prr_racct, oldprr->prr_racct);
4438 
4439 #ifdef RCTL
4440 	/*
4441 	 * Force rctl to reattach rules to processes.
4442 	 */
4443 	FOREACH_PROC_IN_SYSTEM(p) {
4444 		PROC_LOCK(p);
4445 		cred = crhold(p->p_ucred);
4446 		PROC_UNLOCK(p);
4447 		rctl_proc_ucred_changed(p, cred);
4448 		crfree(cred);
4449 	}
4450 #endif
4451 
4452 	sx_sunlock(&allproc_lock);
4453 	prison_racct_free_locked(oldprr);
4454 	sx_xunlock(&allprison_lock);
4455 }
4456 
4457 static void
4458 prison_racct_detach(struct prison *pr)
4459 {
4460 
4461 	ASSERT_RACCT_ENABLED();
4462 	sx_assert(&allprison_lock, SA_UNLOCKED);
4463 
4464 	if (pr->pr_prison_racct == NULL)
4465 		return;
4466 	prison_racct_free(pr->pr_prison_racct);
4467 	pr->pr_prison_racct = NULL;
4468 }
4469 #endif /* RACCT */
4470 
4471 #ifdef DDB
4472 
4473 static void
4474 db_show_prison(struct prison *pr)
4475 {
4476 	struct bool_flags *bf;
4477 	struct jailsys_flags *jsf;
4478 #if defined(INET) || defined(INET6)
4479 	int ii;
4480 #endif
4481 	unsigned f;
4482 #ifdef INET
4483 	char ip4buf[INET_ADDRSTRLEN];
4484 #endif
4485 #ifdef INET6
4486 	char ip6buf[INET6_ADDRSTRLEN];
4487 #endif
4488 
4489 	db_printf("prison %p:\n", pr);
4490 	db_printf(" jid             = %d\n", pr->pr_id);
4491 	db_printf(" name            = %s\n", pr->pr_name);
4492 	db_printf(" parent          = %p\n", pr->pr_parent);
4493 	db_printf(" ref             = %d\n", pr->pr_ref);
4494 	db_printf(" uref            = %d\n", pr->pr_uref);
4495 	db_printf(" state           = %s\n",
4496 	    pr->pr_state == PRISON_STATE_ALIVE ? "alive" :
4497 	    pr->pr_state == PRISON_STATE_DYING ? "dying" :
4498 	    "invalid");
4499 	db_printf(" path            = %s\n", pr->pr_path);
4500 	db_printf(" cpuset          = %d\n", pr->pr_cpuset
4501 	    ? pr->pr_cpuset->cs_id : -1);
4502 #ifdef VIMAGE
4503 	db_printf(" vnet            = %p\n", pr->pr_vnet);
4504 #endif
4505 	db_printf(" root            = %p\n", pr->pr_root);
4506 	db_printf(" securelevel     = %d\n", pr->pr_securelevel);
4507 	db_printf(" devfs_rsnum     = %d\n", pr->pr_devfs_rsnum);
4508 	db_printf(" children.max    = %d\n", pr->pr_childmax);
4509 	db_printf(" children.cur    = %d\n", pr->pr_childcount);
4510 	db_printf(" child           = %p\n", LIST_FIRST(&pr->pr_children));
4511 	db_printf(" sibling         = %p\n", LIST_NEXT(pr, pr_sibling));
4512 	db_printf(" flags           = 0x%x", pr->pr_flags);
4513 	for (bf = pr_flag_bool; bf < pr_flag_bool + nitems(pr_flag_bool); bf++)
4514 		if (pr->pr_flags & bf->flag)
4515 			db_printf(" %s", bf->name);
4516 	for (jsf = pr_flag_jailsys;
4517 	     jsf < pr_flag_jailsys + nitems(pr_flag_jailsys);
4518 	     jsf++) {
4519 		f = pr->pr_flags & (jsf->disable | jsf->new);
4520 		db_printf(" %-16s= %s\n", jsf->name,
4521 		    (f != 0 && f == jsf->disable) ? "disable"
4522 		    : (f == jsf->new) ? "new"
4523 		    : "inherit");
4524 	}
4525 	db_printf(" allow           = 0x%x", pr->pr_allow);
4526 	for (bf = pr_flag_allow;
4527 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
4528 		atomic_load_int(&bf->flag) != 0;
4529 	     bf++)
4530 		if (pr->pr_allow & bf->flag)
4531 			db_printf(" %s", bf->name);
4532 	db_printf("\n");
4533 	db_printf(" enforce_statfs  = %d\n", pr->pr_enforce_statfs);
4534 	db_printf(" host.hostname   = %s\n", pr->pr_hostname);
4535 	db_printf(" host.domainname = %s\n", pr->pr_domainname);
4536 	db_printf(" host.hostuuid   = %s\n", pr->pr_hostuuid);
4537 	db_printf(" host.hostid     = %lu\n", pr->pr_hostid);
4538 #ifdef INET
4539 	db_printf(" ip4s            = %d\n", pr->pr_ip4s);
4540 	for (ii = 0; ii < pr->pr_ip4s; ii++)
4541 		db_printf(" %s %s\n",
4542 		    ii == 0 ? "ip4.addr        =" : "                 ",
4543 		    inet_ntoa_r(pr->pr_ip4[ii], ip4buf));
4544 #endif
4545 #ifdef INET6
4546 	db_printf(" ip6s            = %d\n", pr->pr_ip6s);
4547 	for (ii = 0; ii < pr->pr_ip6s; ii++)
4548 		db_printf(" %s %s\n",
4549 		    ii == 0 ? "ip6.addr        =" : "                 ",
4550 		    ip6_sprintf(ip6buf, &pr->pr_ip6[ii]));
4551 #endif
4552 }
4553 
4554 DB_SHOW_COMMAND(prison, db_show_prison_command)
4555 {
4556 	struct prison *pr;
4557 
4558 	if (!have_addr) {
4559 		/*
4560 		 * Show all prisons in the list, and prison0 which is not
4561 		 * listed.
4562 		 */
4563 		db_show_prison(&prison0);
4564 		if (!db_pager_quit) {
4565 			TAILQ_FOREACH(pr, &allprison, pr_list) {
4566 				db_show_prison(pr);
4567 				if (db_pager_quit)
4568 					break;
4569 			}
4570 		}
4571 		return;
4572 	}
4573 
4574 	if (addr == 0)
4575 		pr = &prison0;
4576 	else {
4577 		/* Look for a prison with the ID and with references. */
4578 		TAILQ_FOREACH(pr, &allprison, pr_list)
4579 			if (pr->pr_id == addr && pr->pr_ref > 0)
4580 				break;
4581 		if (pr == NULL)
4582 			/* Look again, without requiring a reference. */
4583 			TAILQ_FOREACH(pr, &allprison, pr_list)
4584 				if (pr->pr_id == addr)
4585 					break;
4586 		if (pr == NULL)
4587 			/* Assume address points to a valid prison. */
4588 			pr = (struct prison *)addr;
4589 	}
4590 	db_show_prison(pr);
4591 }
4592 
4593 #endif /* DDB */
4594