xref: /freebsd/sys/kern/kern_jail.c (revision aa79fe245de7616cda41b69a296a5ce209c95c45)
1 /*-
2  * Copyright (c) 1999 Poul-Henning Kamp.
3  * Copyright (c) 2008 Bjoern A. Zeeb.
4  * Copyright (c) 2009 James Gritton.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_compat.h"
33 #include "opt_ddb.h"
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 
37 #include <sys/param.h>
38 #include <sys/types.h>
39 #include <sys/kernel.h>
40 #include <sys/systm.h>
41 #include <sys/errno.h>
42 #include <sys/sysproto.h>
43 #include <sys/malloc.h>
44 #include <sys/osd.h>
45 #include <sys/priv.h>
46 #include <sys/proc.h>
47 #include <sys/taskqueue.h>
48 #include <sys/fcntl.h>
49 #include <sys/jail.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/sx.h>
53 #include <sys/sysent.h>
54 #include <sys/namei.h>
55 #include <sys/mount.h>
56 #include <sys/queue.h>
57 #include <sys/socket.h>
58 #include <sys/syscallsubr.h>
59 #include <sys/sysctl.h>
60 #include <sys/vnode.h>
61 #include <sys/vimage.h>
62 #include <net/if.h>
63 #include <netinet/in.h>
64 #ifdef DDB
65 #include <ddb/ddb.h>
66 #ifdef INET6
67 #include <netinet6/in6_var.h>
68 #endif /* INET6 */
69 #endif /* DDB */
70 
71 #include <security/mac/mac_framework.h>
72 
73 MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
74 
75 /* prison0 describes what is "real" about the system. */
76 struct prison prison0 = {
77 	.pr_id		= 0,
78 	.pr_name	= "0",
79 	.pr_ref		= 1,
80 	.pr_uref	= 1,
81 	.pr_path	= "/",
82 	.pr_securelevel	= -1,
83 	.pr_hostuuid	= "00000000-0000-0000-0000-000000000000",
84 	.pr_children	= LIST_HEAD_INITIALIZER(&prison0.pr_children),
85 	.pr_flags	= PR_HOST,
86 	.pr_allow	= PR_ALLOW_ALL,
87 };
88 MTX_SYSINIT(prison0, &prison0.pr_mtx, "jail mutex", MTX_DEF);
89 
90 /* allprison and lastprid are protected by allprison_lock. */
91 struct	sx allprison_lock;
92 SX_SYSINIT(allprison_lock, &allprison_lock, "allprison");
93 struct	prisonlist allprison = TAILQ_HEAD_INITIALIZER(allprison);
94 int	lastprid = 0;
95 
96 static int do_jail_attach(struct thread *td, struct prison *pr);
97 static void prison_complete(void *context, int pending);
98 static void prison_deref(struct prison *pr, int flags);
99 static char *prison_path(struct prison *pr1, struct prison *pr2);
100 static void prison_remove_one(struct prison *pr);
101 #ifdef INET
102 static int _prison_check_ip4(struct prison *pr, struct in_addr *ia);
103 static int prison_restrict_ip4(struct prison *pr, struct in_addr *newip4);
104 #endif
105 #ifdef INET6
106 static int _prison_check_ip6(struct prison *pr, struct in6_addr *ia6);
107 static int prison_restrict_ip6(struct prison *pr, struct in6_addr *newip6);
108 #endif
109 
110 /* Flags for prison_deref */
111 #define	PD_DEREF	0x01
112 #define	PD_DEUREF	0x02
113 #define	PD_LOCKED	0x04
114 #define	PD_LIST_SLOCKED	0x08
115 #define	PD_LIST_XLOCKED	0x10
116 
117 /*
118  * Parameter names corresponding to PR_* flag values
119  */
120 static char *pr_flag_names[] = {
121 	[0] = "persist",
122 	"host",
123 #ifdef INET
124 	"ip4",
125 #endif
126 #ifdef INET6
127 	[3] = "ip6",
128 #endif
129 #ifdef VIMAGE
130 	[4] = "vnet",
131 #endif
132 };
133 
134 static char *pr_flag_nonames[] = {
135 	[0] = "nopersist",
136 	"nohost",
137 #ifdef INET
138 	"noip4",
139 #endif
140 #ifdef INET6
141 	[3] = "noip6",
142 #endif
143 #ifdef VIMAGE
144 	[4] = "novnet",
145 #endif
146 };
147 
148 static char *pr_allow_names[] = {
149 	"allow.set_hostname",
150 	"allow.sysvipc",
151 	"allow.raw_sockets",
152 	"allow.chflags",
153 	"allow.mount",
154 	"allow.quotas",
155 	"allow.jails",
156 	"allow.socket_af",
157 };
158 
159 static char *pr_allow_nonames[] = {
160 	"allow.noset_hostname",
161 	"allow.nosysvipc",
162 	"allow.noraw_sockets",
163 	"allow.nochflags",
164 	"allow.nomount",
165 	"allow.noquotas",
166 	"allow.nojails",
167 	"allow.nosocket_af",
168 };
169 
170 #define	JAIL_DEFAULT_ALLOW	PR_ALLOW_SET_HOSTNAME
171 static unsigned jail_default_allow = JAIL_DEFAULT_ALLOW;
172 static int jail_default_enforce_statfs = 2;
173 #if defined(INET) || defined(INET6)
174 static unsigned jail_max_af_ips = 255;
175 #endif
176 
177 #ifdef INET
178 static int
179 qcmp_v4(const void *ip1, const void *ip2)
180 {
181 	in_addr_t iaa, iab;
182 
183 	/*
184 	 * We need to compare in HBO here to get the list sorted as expected
185 	 * by the result of the code.  Sorting NBO addresses gives you
186 	 * interesting results.  If you do not understand, do not try.
187 	 */
188 	iaa = ntohl(((const struct in_addr *)ip1)->s_addr);
189 	iab = ntohl(((const struct in_addr *)ip2)->s_addr);
190 
191 	/*
192 	 * Do not simply return the difference of the two numbers, the int is
193 	 * not wide enough.
194 	 */
195 	if (iaa > iab)
196 		return (1);
197 	else if (iaa < iab)
198 		return (-1);
199 	else
200 		return (0);
201 }
202 #endif
203 
204 #ifdef INET6
205 static int
206 qcmp_v6(const void *ip1, const void *ip2)
207 {
208 	const struct in6_addr *ia6a, *ia6b;
209 	int i, rc;
210 
211 	ia6a = (const struct in6_addr *)ip1;
212 	ia6b = (const struct in6_addr *)ip2;
213 
214 	rc = 0;
215 	for (i = 0; rc == 0 && i < sizeof(struct in6_addr); i++) {
216 		if (ia6a->s6_addr[i] > ia6b->s6_addr[i])
217 			rc = 1;
218 		else if (ia6a->s6_addr[i] < ia6b->s6_addr[i])
219 			rc = -1;
220 	}
221 	return (rc);
222 }
223 #endif
224 
225 /*
226  * struct jail_args {
227  *	struct jail *jail;
228  * };
229  */
230 int
231 jail(struct thread *td, struct jail_args *uap)
232 {
233 	uint32_t version;
234 	int error;
235 	struct jail j;
236 
237 	error = copyin(uap->jail, &version, sizeof(uint32_t));
238 	if (error)
239 		return (error);
240 
241 	switch (version) {
242 	case 0:
243 	{
244 		struct jail_v0 j0;
245 
246 		/* FreeBSD single IPv4 jails. */
247 		bzero(&j, sizeof(struct jail));
248 		error = copyin(uap->jail, &j0, sizeof(struct jail_v0));
249 		if (error)
250 			return (error);
251 		j.version = j0.version;
252 		j.path = j0.path;
253 		j.hostname = j0.hostname;
254 		j.ip4s = j0.ip_number;
255 		break;
256 	}
257 
258 	case 1:
259 		/*
260 		 * Version 1 was used by multi-IPv4 jail implementations
261 		 * that never made it into the official kernel.
262 		 */
263 		return (EINVAL);
264 
265 	case 2:	/* JAIL_API_VERSION */
266 		/* FreeBSD multi-IPv4/IPv6,noIP jails. */
267 		error = copyin(uap->jail, &j, sizeof(struct jail));
268 		if (error)
269 			return (error);
270 		break;
271 
272 	default:
273 		/* Sci-Fi jails are not supported, sorry. */
274 		return (EINVAL);
275 	}
276 	return (kern_jail(td, &j));
277 }
278 
279 int
280 kern_jail(struct thread *td, struct jail *j)
281 {
282 	struct iovec optiov[2 * (4
283 			    + sizeof(pr_allow_names) / sizeof(pr_allow_names[0])
284 #ifdef INET
285 			    + 1
286 #endif
287 #ifdef INET6
288 			    + 1
289 #endif
290 			    )];
291 	struct uio opt;
292 	char *u_path, *u_hostname, *u_name;
293 #ifdef INET
294 	uint32_t ip4s;
295 	struct in_addr *u_ip4;
296 #endif
297 #ifdef INET6
298 	struct in6_addr *u_ip6;
299 #endif
300 	size_t tmplen;
301 	int error, enforce_statfs, fi;
302 
303 	bzero(&optiov, sizeof(optiov));
304 	opt.uio_iov = optiov;
305 	opt.uio_iovcnt = 0;
306 	opt.uio_offset = -1;
307 	opt.uio_resid = -1;
308 	opt.uio_segflg = UIO_SYSSPACE;
309 	opt.uio_rw = UIO_READ;
310 	opt.uio_td = td;
311 
312 	/* Set permissions for top-level jails from sysctls. */
313 	if (!jailed(td->td_ucred)) {
314 		for (fi = 0; fi < sizeof(pr_allow_names) /
315 		     sizeof(pr_allow_names[0]); fi++) {
316 			optiov[opt.uio_iovcnt].iov_base =
317 			    (jail_default_allow & (1 << fi))
318 			    ? pr_allow_names[fi] : pr_allow_nonames[fi];
319 			optiov[opt.uio_iovcnt].iov_len =
320 			    strlen(optiov[opt.uio_iovcnt].iov_base) + 1;
321 			opt.uio_iovcnt += 2;
322 		}
323 		optiov[opt.uio_iovcnt].iov_base = "enforce_statfs";
324 		optiov[opt.uio_iovcnt].iov_len = sizeof("enforce_statfs");
325 		opt.uio_iovcnt++;
326 		enforce_statfs = jail_default_enforce_statfs;
327 		optiov[opt.uio_iovcnt].iov_base = &enforce_statfs;
328 		optiov[opt.uio_iovcnt].iov_len = sizeof(enforce_statfs);
329 		opt.uio_iovcnt++;
330 	}
331 
332 	tmplen = MAXPATHLEN + MAXHOSTNAMELEN + MAXHOSTNAMELEN;
333 #ifdef INET
334 	ip4s = (j->version == 0) ? 1 : j->ip4s;
335 	if (ip4s > jail_max_af_ips)
336 		return (EINVAL);
337 	tmplen += ip4s * sizeof(struct in_addr);
338 #else
339 	if (j->ip4s > 0)
340 		return (EINVAL);
341 #endif
342 #ifdef INET6
343 	if (j->ip6s > jail_max_af_ips)
344 		return (EINVAL);
345 	tmplen += j->ip6s * sizeof(struct in6_addr);
346 #else
347 	if (j->ip6s > 0)
348 		return (EINVAL);
349 #endif
350 	u_path = malloc(tmplen, M_TEMP, M_WAITOK);
351 	u_hostname = u_path + MAXPATHLEN;
352 	u_name = u_hostname + MAXHOSTNAMELEN;
353 #ifdef INET
354 	u_ip4 = (struct in_addr *)(u_name + MAXHOSTNAMELEN);
355 #endif
356 #ifdef INET6
357 #ifdef INET
358 	u_ip6 = (struct in6_addr *)(u_ip4 + ip4s);
359 #else
360 	u_ip6 = (struct in6_addr *)(u_name + MAXHOSTNAMELEN);
361 #endif
362 #endif
363 	optiov[opt.uio_iovcnt].iov_base = "path";
364 	optiov[opt.uio_iovcnt].iov_len = sizeof("path");
365 	opt.uio_iovcnt++;
366 	optiov[opt.uio_iovcnt].iov_base = u_path;
367 	error = copyinstr(j->path, u_path, MAXPATHLEN,
368 	    &optiov[opt.uio_iovcnt].iov_len);
369 	if (error) {
370 		free(u_path, M_TEMP);
371 		return (error);
372 	}
373 	opt.uio_iovcnt++;
374 	optiov[opt.uio_iovcnt].iov_base = "host.hostname";
375 	optiov[opt.uio_iovcnt].iov_len = sizeof("host.hostname");
376 	opt.uio_iovcnt++;
377 	optiov[opt.uio_iovcnt].iov_base = u_hostname;
378 	error = copyinstr(j->hostname, u_hostname, MAXHOSTNAMELEN,
379 	    &optiov[opt.uio_iovcnt].iov_len);
380 	if (error) {
381 		free(u_path, M_TEMP);
382 		return (error);
383 	}
384 	opt.uio_iovcnt++;
385 	if (j->jailname != NULL) {
386 		optiov[opt.uio_iovcnt].iov_base = "name";
387 		optiov[opt.uio_iovcnt].iov_len = sizeof("name");
388 		opt.uio_iovcnt++;
389 		optiov[opt.uio_iovcnt].iov_base = u_name;
390 		error = copyinstr(j->jailname, u_name, MAXHOSTNAMELEN,
391 		    &optiov[opt.uio_iovcnt].iov_len);
392 		if (error) {
393 			free(u_path, M_TEMP);
394 			return (error);
395 		}
396 		opt.uio_iovcnt++;
397 	}
398 #ifdef INET
399 	optiov[opt.uio_iovcnt].iov_base = "ip4.addr";
400 	optiov[opt.uio_iovcnt].iov_len = sizeof("ip4.addr");
401 	opt.uio_iovcnt++;
402 	optiov[opt.uio_iovcnt].iov_base = u_ip4;
403 	optiov[opt.uio_iovcnt].iov_len = ip4s * sizeof(struct in_addr);
404 	if (j->version == 0)
405 		u_ip4->s_addr = j->ip4s;
406 	else {
407 		error = copyin(j->ip4, u_ip4, optiov[opt.uio_iovcnt].iov_len);
408 		if (error) {
409 			free(u_path, M_TEMP);
410 			return (error);
411 		}
412 	}
413 	opt.uio_iovcnt++;
414 #endif
415 #ifdef INET6
416 	optiov[opt.uio_iovcnt].iov_base = "ip6.addr";
417 	optiov[opt.uio_iovcnt].iov_len = sizeof("ip6.addr");
418 	opt.uio_iovcnt++;
419 	optiov[opt.uio_iovcnt].iov_base = u_ip6;
420 	optiov[opt.uio_iovcnt].iov_len = j->ip6s * sizeof(struct in6_addr);
421 	error = copyin(j->ip6, u_ip6, optiov[opt.uio_iovcnt].iov_len);
422 	if (error) {
423 		free(u_path, M_TEMP);
424 		return (error);
425 	}
426 	opt.uio_iovcnt++;
427 #endif
428 	KASSERT(opt.uio_iovcnt <= sizeof(optiov) / sizeof(optiov[0]),
429 	    ("kern_jail: too many iovecs (%d)", opt.uio_iovcnt));
430 	error = kern_jail_set(td, &opt, JAIL_CREATE | JAIL_ATTACH);
431 	free(u_path, M_TEMP);
432 	return (error);
433 }
434 
435 
436 /*
437  * struct jail_set_args {
438  *	struct iovec *iovp;
439  *	unsigned int iovcnt;
440  *	int flags;
441  * };
442  */
443 int
444 jail_set(struct thread *td, struct jail_set_args *uap)
445 {
446 	struct uio *auio;
447 	int error;
448 
449 	/* Check that we have an even number of iovecs. */
450 	if (uap->iovcnt & 1)
451 		return (EINVAL);
452 
453 	error = copyinuio(uap->iovp, uap->iovcnt, &auio);
454 	if (error)
455 		return (error);
456 	error = kern_jail_set(td, auio, uap->flags);
457 	free(auio, M_IOV);
458 	return (error);
459 }
460 
461 int
462 kern_jail_set(struct thread *td, struct uio *optuio, int flags)
463 {
464 	struct nameidata nd;
465 #ifdef INET
466 	struct in_addr *ip4;
467 #endif
468 #ifdef INET6
469 	struct in6_addr *ip6;
470 #endif
471 	struct vfsopt *opt;
472 	struct vfsoptlist *opts;
473 	struct prison *pr, *deadpr, *mypr, *ppr, *tpr;
474 	struct vnode *root;
475 	char *domain, *errmsg, *host, *name, *p, *path, *uuid;
476 #if defined(INET) || defined(INET6)
477 	void *op;
478 #endif
479 	unsigned long hid;
480 	size_t namelen, onamelen;
481 	int created, cuflags, descend, enforce, error, errmsg_len, errmsg_pos;
482 	int gotenforce, gothid, gotslevel, fi, jid, len;
483 	int slevel, vfslocked;
484 #if defined(INET) || defined(INET6)
485 	int ii, ij;
486 #endif
487 #ifdef INET
488 	int ip4s, ip4a, redo_ip4;
489 #endif
490 #ifdef INET6
491 	int ip6s, ip6a, redo_ip6;
492 #endif
493 	unsigned pr_flags, ch_flags;
494 	unsigned pr_allow, ch_allow, tallow;
495 	char numbuf[12];
496 
497 	error = priv_check(td, PRIV_JAIL_SET);
498 	if (!error && (flags & JAIL_ATTACH))
499 		error = priv_check(td, PRIV_JAIL_ATTACH);
500 	if (error)
501 		return (error);
502 	mypr = ppr = td->td_ucred->cr_prison;
503 	if ((flags & JAIL_CREATE) && !(mypr->pr_allow & PR_ALLOW_JAILS))
504 		return (EPERM);
505 	if (flags & ~JAIL_SET_MASK)
506 		return (EINVAL);
507 
508 	/*
509 	 * Check all the parameters before committing to anything.  Not all
510 	 * errors can be caught early, but we may as well try.  Also, this
511 	 * takes care of some expensive stuff (path lookup) before getting
512 	 * the allprison lock.
513 	 *
514 	 * XXX Jails are not filesystems, and jail parameters are not mount
515 	 *     options.  But it makes more sense to re-use the vfsopt code
516 	 *     than duplicate it under a different name.
517 	 */
518 	error = vfs_buildopts(optuio, &opts);
519 	if (error)
520 		return (error);
521 #ifdef INET
522 	ip4a = 0;
523 	ip4 = NULL;
524 #endif
525 #ifdef INET6
526 	ip6a = 0;
527 	ip6 = NULL;
528 #endif
529 
530 #if defined(INET) || defined(INET6)
531  again:
532 #endif
533 	error = vfs_copyopt(opts, "jid", &jid, sizeof(jid));
534 	if (error == ENOENT)
535 		jid = 0;
536 	else if (error != 0)
537 		goto done_free;
538 
539 	error = vfs_copyopt(opts, "securelevel", &slevel, sizeof(slevel));
540 	if (error == ENOENT)
541 		gotslevel = 0;
542 	else if (error != 0)
543 		goto done_free;
544 	else
545 		gotslevel = 1;
546 
547 	error = vfs_copyopt(opts, "enforce_statfs", &enforce, sizeof(enforce));
548 	gotenforce = (error == 0);
549 	if (gotenforce) {
550 		if (enforce < 0 || enforce > 2)
551 			return (EINVAL);
552 	} else if (error != ENOENT)
553 		goto done_free;
554 
555 	pr_flags = ch_flags = 0;
556 	for (fi = 0; fi < sizeof(pr_flag_names) / sizeof(pr_flag_names[0]);
557 	    fi++) {
558 		if (pr_flag_names[fi] == NULL)
559 			continue;
560 		vfs_flagopt(opts, pr_flag_names[fi], &pr_flags, 1 << fi);
561 		vfs_flagopt(opts, pr_flag_nonames[fi], &ch_flags, 1 << fi);
562 	}
563 	ch_flags |= pr_flags;
564 	if ((flags & (JAIL_CREATE | JAIL_UPDATE | JAIL_ATTACH)) == JAIL_CREATE
565 	    && !(pr_flags & PR_PERSIST)) {
566 		error = EINVAL;
567 		vfs_opterror(opts, "new jail must persist or attach");
568 		goto done_errmsg;
569 	}
570 #ifdef VIMAGE
571 	if ((flags & JAIL_UPDATE) && (ch_flags & PR_VNET)) {
572 		error = EINVAL;
573 		vfs_opterror(opts, "vnet cannot be changed after creation");
574 		goto done_errmsg;
575 	}
576 #endif
577 
578 	pr_allow = ch_allow = 0;
579 	for (fi = 0; fi < sizeof(pr_allow_names) / sizeof(pr_allow_names[0]);
580 	    fi++) {
581 		vfs_flagopt(opts, pr_allow_names[fi], &pr_allow, 1 << fi);
582 		vfs_flagopt(opts, pr_allow_nonames[fi], &ch_allow, 1 << fi);
583 	}
584 	ch_allow |= pr_allow;
585 
586 	error = vfs_getopt(opts, "name", (void **)&name, &len);
587 	if (error == ENOENT)
588 		name = NULL;
589 	else if (error != 0)
590 		goto done_free;
591 	else {
592 		if (len == 0 || name[len - 1] != '\0') {
593 			error = EINVAL;
594 			goto done_free;
595 		}
596 		if (len > MAXHOSTNAMELEN) {
597 			error = ENAMETOOLONG;
598 			goto done_free;
599 		}
600 	}
601 
602 	error = vfs_getopt(opts, "host.hostname", (void **)&host, &len);
603 	if (error == ENOENT)
604 		host = NULL;
605 	else if (error != 0)
606 		goto done_free;
607 	else {
608 		ch_flags |= PR_HOST;
609 		pr_flags |= PR_HOST;
610 		if (len == 0 || host[len - 1] != '\0') {
611 			error = EINVAL;
612 			goto done_free;
613 		}
614 		if (len > MAXHOSTNAMELEN) {
615 			error = ENAMETOOLONG;
616 			goto done_free;
617 		}
618 	}
619 
620 	error = vfs_getopt(opts, "host.domainname", (void **)&domain, &len);
621 	if (error == ENOENT)
622 		domain = NULL;
623 	else if (error != 0)
624 		goto done_free;
625 	else {
626 		ch_flags |= PR_HOST;
627 		pr_flags |= PR_HOST;
628 		if (len == 0 || domain[len - 1] != '\0') {
629 			error = EINVAL;
630 			goto done_free;
631 		}
632 		if (len > MAXHOSTNAMELEN) {
633 			error = ENAMETOOLONG;
634 			goto done_free;
635 		}
636 	}
637 
638 	error = vfs_getopt(opts, "host.hostuuid", (void **)&uuid, &len);
639 	if (error == ENOENT)
640 		uuid = NULL;
641 	else if (error != 0)
642 		goto done_free;
643 	else {
644 		ch_flags |= PR_HOST;
645 		pr_flags |= PR_HOST;
646 		if (len == 0 || uuid[len - 1] != '\0') {
647 			error = EINVAL;
648 			goto done_free;
649 		}
650 		if (len > HOSTUUIDLEN) {
651 			error = ENAMETOOLONG;
652 			goto done_free;
653 		}
654 	}
655 
656 #ifdef COMPAT_IA32
657 	if (td->td_proc->p_sysent->sv_flags & SV_IA32) {
658 		uint32_t hid32;
659 
660 		error = vfs_copyopt(opts, "host.hostid", &hid32, sizeof(hid32));
661 		hid = hid32;
662 	} else
663 #endif
664 		error = vfs_copyopt(opts, "host.hostid", &hid, sizeof(hid));
665 	if (error == ENOENT)
666 		gothid = 0;
667 	else if (error != 0)
668 		goto done_free;
669 	else {
670 		gothid = 1;
671 		ch_flags |= PR_HOST;
672 		pr_flags |= PR_HOST;
673 	}
674 
675 	/* This might be the second time around for this option. */
676 #ifdef INET
677 	error = vfs_getopt(opts, "ip4.addr", &op, &ip4s);
678 	if (error == ENOENT)
679 		ip4s = -1;
680 	else if (error != 0)
681 		goto done_free;
682 	else if (ip4s & (sizeof(*ip4) - 1)) {
683 		error = EINVAL;
684 		goto done_free;
685 	} else {
686 		ch_flags |= PR_IP4_USER;
687 		pr_flags |= PR_IP4_USER;
688 		if (ip4s > 0) {
689 			ip4s /= sizeof(*ip4);
690 			if (ip4s > jail_max_af_ips) {
691 				error = EINVAL;
692 				vfs_opterror(opts, "too many IPv4 addresses");
693 				goto done_errmsg;
694 			}
695 			if (ip4a < ip4s) {
696 				ip4a = ip4s;
697 				free(ip4, M_PRISON);
698 				ip4 = NULL;
699 			}
700 			if (ip4 == NULL)
701 				ip4 = malloc(ip4a * sizeof(*ip4), M_PRISON,
702 				    M_WAITOK);
703 			bcopy(op, ip4, ip4s * sizeof(*ip4));
704 			/*
705 			 * IP addresses are all sorted but ip[0] to preserve
706 			 * the primary IP address as given from userland.
707 			 * This special IP is used for unbound outgoing
708 			 * connections as well for "loopback" traffic.
709 			 */
710 			if (ip4s > 1)
711 				qsort(ip4 + 1, ip4s - 1, sizeof(*ip4), qcmp_v4);
712 			/*
713 			 * Check for duplicate addresses and do some simple
714 			 * zero and broadcast checks. If users give other bogus
715 			 * addresses it is their problem.
716 			 *
717 			 * We do not have to care about byte order for these
718 			 * checks so we will do them in NBO.
719 			 */
720 			for (ii = 0; ii < ip4s; ii++) {
721 				if (ip4[ii].s_addr == INADDR_ANY ||
722 				    ip4[ii].s_addr == INADDR_BROADCAST) {
723 					error = EINVAL;
724 					goto done_free;
725 				}
726 				if ((ii+1) < ip4s &&
727 				    (ip4[0].s_addr == ip4[ii+1].s_addr ||
728 				     ip4[ii].s_addr == ip4[ii+1].s_addr)) {
729 					error = EINVAL;
730 					goto done_free;
731 				}
732 			}
733 		}
734 	}
735 #endif
736 
737 #ifdef INET6
738 	error = vfs_getopt(opts, "ip6.addr", &op, &ip6s);
739 	if (error == ENOENT)
740 		ip6s = -1;
741 	else if (error != 0)
742 		goto done_free;
743 	else if (ip6s & (sizeof(*ip6) - 1)) {
744 		error = EINVAL;
745 		goto done_free;
746 	} else {
747 		ch_flags |= PR_IP6_USER;
748 		pr_flags |= PR_IP6_USER;
749 		if (ip6s > 0) {
750 			ip6s /= sizeof(*ip6);
751 			if (ip6s > jail_max_af_ips) {
752 				error = EINVAL;
753 				vfs_opterror(opts, "too many IPv6 addresses");
754 				goto done_errmsg;
755 			}
756 			if (ip6a < ip6s) {
757 				ip6a = ip6s;
758 				free(ip6, M_PRISON);
759 				ip6 = NULL;
760 			}
761 			if (ip6 == NULL)
762 				ip6 = malloc(ip6a * sizeof(*ip6), M_PRISON,
763 				    M_WAITOK);
764 			bcopy(op, ip6, ip6s * sizeof(*ip6));
765 			if (ip6s > 1)
766 				qsort(ip6 + 1, ip6s - 1, sizeof(*ip6), qcmp_v6);
767 			for (ii = 0; ii < ip6s; ii++) {
768 				if (IN6_IS_ADDR_UNSPECIFIED(&ip6[ii])) {
769 					error = EINVAL;
770 					goto done_free;
771 				}
772 				if ((ii+1) < ip6s &&
773 				    (IN6_ARE_ADDR_EQUAL(&ip6[0], &ip6[ii+1]) ||
774 				     IN6_ARE_ADDR_EQUAL(&ip6[ii], &ip6[ii+1])))
775 				{
776 					error = EINVAL;
777 					goto done_free;
778 				}
779 			}
780 		}
781 	}
782 #endif
783 
784 	root = NULL;
785 	error = vfs_getopt(opts, "path", (void **)&path, &len);
786 	if (error == ENOENT)
787 		path = NULL;
788 	else if (error != 0)
789 		goto done_free;
790 	else {
791 		if (flags & JAIL_UPDATE) {
792 			error = EINVAL;
793 			vfs_opterror(opts,
794 			    "path cannot be changed after creation");
795 			goto done_errmsg;
796 		}
797 		if (len == 0 || path[len - 1] != '\0') {
798 			error = EINVAL;
799 			goto done_free;
800 		}
801 		if (len < 2 || (len == 2 && path[0] == '/'))
802 			path = NULL;
803 		else {
804 			/* Leave room for a real-root full pathname. */
805 			if (len + (path[0] == '/' && strcmp(mypr->pr_path, "/")
806 			    ? strlen(mypr->pr_path) : 0) > MAXPATHLEN) {
807 				error = ENAMETOOLONG;
808 				goto done_free;
809 			}
810 			NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW, UIO_SYSSPACE,
811 			    path, td);
812 			error = namei(&nd);
813 			if (error)
814 				goto done_free;
815 			vfslocked = NDHASGIANT(&nd);
816 			root = nd.ni_vp;
817 			NDFREE(&nd, NDF_ONLY_PNBUF);
818 			if (root->v_type != VDIR) {
819 				error = ENOTDIR;
820 				vrele(root);
821 				VFS_UNLOCK_GIANT(vfslocked);
822 				goto done_free;
823 			}
824 			VFS_UNLOCK_GIANT(vfslocked);
825 		}
826 	}
827 
828 	/*
829 	 * Grab the allprison lock before letting modules check their
830 	 * parameters.  Once we have it, do not let go so we'll have a
831 	 * consistent view of the OSD list.
832 	 */
833 	sx_xlock(&allprison_lock);
834 	error = osd_jail_call(NULL, PR_METHOD_CHECK, opts);
835 	if (error)
836 		goto done_unlock_list;
837 
838 	/* By now, all parameters should have been noted. */
839 	TAILQ_FOREACH(opt, opts, link) {
840 		if (!opt->seen && strcmp(opt->name, "errmsg")) {
841 			error = EINVAL;
842 			vfs_opterror(opts, "unknown parameter: %s", opt->name);
843 			goto done_unlock_list;
844 		}
845 	}
846 
847 	/*
848 	 * See if we are creating a new record or updating an existing one.
849 	 * This abuses the file error codes ENOENT and EEXIST.
850 	 */
851 	cuflags = flags & (JAIL_CREATE | JAIL_UPDATE);
852 	if (!cuflags) {
853 		error = EINVAL;
854 		vfs_opterror(opts, "no valid operation (create or update)");
855 		goto done_unlock_list;
856 	}
857 	pr = NULL;
858 	if (jid != 0) {
859 		/*
860 		 * See if a requested jid already exists.  There is an
861 		 * information leak here if the jid exists but is not within
862 		 * the caller's jail hierarchy.  Jail creators will get EEXIST
863 		 * even though they cannot see the jail, and CREATE | UPDATE
864 		 * will return ENOENT which is not normally a valid error.
865 		 */
866 		if (jid < 0) {
867 			error = EINVAL;
868 			vfs_opterror(opts, "negative jid");
869 			goto done_unlock_list;
870 		}
871 		pr = prison_find(jid);
872 		if (pr != NULL) {
873 			ppr = pr->pr_parent;
874 			/* Create: jid must not exist. */
875 			if (cuflags == JAIL_CREATE) {
876 				mtx_unlock(&pr->pr_mtx);
877 				error = EEXIST;
878 				vfs_opterror(opts, "jail %d already exists",
879 				    jid);
880 				goto done_unlock_list;
881 			}
882 			if (!prison_ischild(mypr, pr)) {
883 				mtx_unlock(&pr->pr_mtx);
884 				pr = NULL;
885 			} else if (pr->pr_uref == 0) {
886 				if (!(flags & JAIL_DYING)) {
887 					mtx_unlock(&pr->pr_mtx);
888 					error = ENOENT;
889 					vfs_opterror(opts, "jail %d is dying",
890 					    jid);
891 					goto done_unlock_list;
892 				} else if ((flags & JAIL_ATTACH) ||
893 				    (pr_flags & PR_PERSIST)) {
894 					/*
895 					 * A dying jail might be resurrected
896 					 * (via attach or persist), but first
897 					 * it must determine if another jail
898 					 * has claimed its name.  Accomplish
899 					 * this by implicitly re-setting the
900 					 * name.
901 					 */
902 					if (name == NULL)
903 						name = prison_name(mypr, pr);
904 				}
905 			}
906 		}
907 		if (pr == NULL) {
908 			/* Update: jid must exist. */
909 			if (cuflags == JAIL_UPDATE) {
910 				error = ENOENT;
911 				vfs_opterror(opts, "jail %d not found", jid);
912 				goto done_unlock_list;
913 			}
914 		}
915 	}
916 	/*
917 	 * If the caller provided a name, look for a jail by that name.
918 	 * This has different semantics for creates and updates keyed by jid
919 	 * (where the name must not already exist in a different jail),
920 	 * and updates keyed by the name itself (where the name must exist
921 	 * because that is the jail being updated).
922 	 */
923 	if (name != NULL) {
924 		p = strrchr(name, '.');
925 		if (p != NULL) {
926 			/*
927 			 * This is a hierarchical name.  Split it into the
928 			 * parent and child names, and make sure the parent
929 			 * exists or matches an already found jail.
930 			 */
931 			*p = '\0';
932 			if (pr != NULL) {
933 				if (strncmp(name, ppr->pr_name, p - name) ||
934 				    ppr->pr_name[p - name] != '\0') {
935 					mtx_unlock(&pr->pr_mtx);
936 					error = EINVAL;
937 					vfs_opterror(opts,
938 					    "cannot change jail's parent");
939 					goto done_unlock_list;
940 				}
941 			} else {
942 				ppr = prison_find_name(mypr, name);
943 				if (ppr == NULL) {
944 					error = ENOENT;
945 					vfs_opterror(opts,
946 					    "jail \"%s\" not found", name);
947 					goto done_unlock_list;
948 				}
949 				mtx_unlock(&ppr->pr_mtx);
950 			}
951 			name = p + 1;
952 		}
953 		if (name[0] != '\0') {
954 			namelen =
955 			    (ppr == &prison0) ? 0 : strlen(ppr->pr_name) + 1;
956  name_again:
957 			deadpr = NULL;
958 			FOREACH_PRISON_CHILD(ppr, tpr) {
959 				if (tpr != pr && tpr->pr_ref > 0 &&
960 				    !strcmp(tpr->pr_name + namelen, name)) {
961 					if (pr == NULL &&
962 					    cuflags != JAIL_CREATE) {
963 						mtx_lock(&tpr->pr_mtx);
964 						if (tpr->pr_ref > 0) {
965 							/*
966 							 * Use this jail
967 							 * for updates.
968 							 */
969 							if (tpr->pr_uref > 0) {
970 								pr = tpr;
971 								break;
972 							}
973 							deadpr = tpr;
974 						}
975 						mtx_unlock(&tpr->pr_mtx);
976 					} else if (tpr->pr_uref > 0) {
977 						/*
978 						 * Create, or update(jid):
979 						 * name must not exist in an
980 						 * active sibling jail.
981 						 */
982 						error = EEXIST;
983 						if (pr != NULL)
984 							mtx_unlock(&pr->pr_mtx);
985 						vfs_opterror(opts,
986 						   "jail \"%s\" already exists",
987 						   name);
988 						goto done_unlock_list;
989 					}
990 				}
991 			}
992 			/* If no active jail is found, use a dying one. */
993 			if (deadpr != NULL && pr == NULL) {
994 				if (flags & JAIL_DYING) {
995 					mtx_lock(&deadpr->pr_mtx);
996 					if (deadpr->pr_ref == 0) {
997 						mtx_unlock(&deadpr->pr_mtx);
998 						goto name_again;
999 					}
1000 					pr = deadpr;
1001 				} else if (cuflags == JAIL_UPDATE) {
1002 					error = ENOENT;
1003 					vfs_opterror(opts,
1004 					    "jail \"%s\" is dying", name);
1005 					goto done_unlock_list;
1006 				}
1007 			}
1008 			/* Update: name must exist if no jid. */
1009 			else if (cuflags == JAIL_UPDATE && pr == NULL) {
1010 				error = ENOENT;
1011 				vfs_opterror(opts, "jail \"%s\" not found",
1012 				    name);
1013 				goto done_unlock_list;
1014 			}
1015 		}
1016 	}
1017 	/* Update: must provide a jid or name. */
1018 	else if (cuflags == JAIL_UPDATE && pr == NULL) {
1019 		error = ENOENT;
1020 		vfs_opterror(opts, "update specified no jail");
1021 		goto done_unlock_list;
1022 	}
1023 
1024 	/* If there's no prison to update, create a new one and link it in. */
1025 	if (pr == NULL) {
1026 		created = 1;
1027 		mtx_lock(&ppr->pr_mtx);
1028 		if (ppr->pr_ref == 0 || (ppr->pr_flags & PR_REMOVE)) {
1029 			mtx_unlock(&ppr->pr_mtx);
1030 			error = ENOENT;
1031 			vfs_opterror(opts, "parent jail went away!");
1032 			goto done_unlock_list;
1033 		}
1034 		ppr->pr_ref++;
1035 		ppr->pr_uref++;
1036 		mtx_unlock(&ppr->pr_mtx);
1037 		pr = malloc(sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO);
1038 		if (jid == 0) {
1039 			/* Find the next free jid. */
1040 			jid = lastprid + 1;
1041  findnext:
1042 			if (jid == JAIL_MAX)
1043 				jid = 1;
1044 			TAILQ_FOREACH(tpr, &allprison, pr_list) {
1045 				if (tpr->pr_id < jid)
1046 					continue;
1047 				if (tpr->pr_id > jid || tpr->pr_ref == 0) {
1048 					TAILQ_INSERT_BEFORE(tpr, pr, pr_list);
1049 					break;
1050 				}
1051 				if (jid == lastprid) {
1052 					error = EAGAIN;
1053 					vfs_opterror(opts,
1054 					    "no available jail IDs");
1055 					free(pr, M_PRISON);
1056 					prison_deref(ppr, PD_DEREF |
1057 					    PD_DEUREF | PD_LIST_XLOCKED);
1058 					goto done_releroot;
1059 				}
1060 				jid++;
1061 				goto findnext;
1062 			}
1063 			lastprid = jid;
1064 		} else {
1065 			/*
1066 			 * The jail already has a jid (that did not yet exist),
1067 			 * so just find where to insert it.
1068 			 */
1069 			TAILQ_FOREACH(tpr, &allprison, pr_list)
1070 				if (tpr->pr_id >= jid) {
1071 					TAILQ_INSERT_BEFORE(tpr, pr, pr_list);
1072 					break;
1073 				}
1074 		}
1075 		if (tpr == NULL)
1076 			TAILQ_INSERT_TAIL(&allprison, pr, pr_list);
1077 		LIST_INSERT_HEAD(&ppr->pr_children, pr, pr_sibling);
1078 		for (tpr = ppr; tpr != NULL; tpr = tpr->pr_parent)
1079 			tpr->pr_prisoncount++;
1080 
1081 		pr->pr_parent = ppr;
1082 		pr->pr_id = jid;
1083 
1084 		/* Set some default values, and inherit some from the parent. */
1085 		if (name == NULL)
1086 			name = "";
1087 		if (host != NULL || domain != NULL || uuid != NULL || gothid) {
1088 			if (host == NULL)
1089 				host = ppr->pr_hostname;
1090 			if (domain == NULL)
1091 				domain = ppr->pr_domainname;
1092 			if (uuid == NULL)
1093 				uuid = ppr->pr_hostuuid;
1094 			if (!gothid)
1095 				hid = ppr->pr_hostid;
1096 		}
1097 		if (path == NULL) {
1098 			path = "/";
1099 			root = mypr->pr_root;
1100 			vref(root);
1101 		}
1102 #ifdef INET
1103 		pr->pr_flags |= ppr->pr_flags & PR_IP4;
1104 		pr->pr_ip4s = ppr->pr_ip4s;
1105 		if (ppr->pr_ip4 != NULL) {
1106 			pr->pr_ip4 = malloc(pr->pr_ip4s *
1107 			    sizeof(struct in_addr), M_PRISON, M_WAITOK);
1108 			bcopy(ppr->pr_ip4, pr->pr_ip4,
1109 			    pr->pr_ip4s * sizeof(*pr->pr_ip4));
1110 		}
1111 #endif
1112 #ifdef INET6
1113 		pr->pr_flags |= ppr->pr_flags & PR_IP6;
1114 		pr->pr_ip6s = ppr->pr_ip6s;
1115 		if (ppr->pr_ip6 != NULL) {
1116 			pr->pr_ip6 = malloc(pr->pr_ip6s *
1117 			    sizeof(struct in6_addr), M_PRISON, M_WAITOK);
1118 			bcopy(ppr->pr_ip6, pr->pr_ip6,
1119 			    pr->pr_ip6s * sizeof(*pr->pr_ip6));
1120 		}
1121 #endif
1122 		pr->pr_securelevel = ppr->pr_securelevel;
1123 		pr->pr_allow = JAIL_DEFAULT_ALLOW & ppr->pr_allow;
1124 		pr->pr_enforce_statfs = ppr->pr_enforce_statfs;
1125 
1126 		LIST_INIT(&pr->pr_children);
1127 		mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF | MTX_DUPOK);
1128 
1129 #ifdef VIMAGE
1130 		/* Allocate a new vnet if specified. */
1131 		pr->pr_vnet = (pr_flags & PR_VNET)
1132 		    ? vnet_alloc() : ppr->pr_vnet;
1133 #endif
1134 		/*
1135 		 * Allocate a dedicated cpuset for each jail.
1136 		 * Unlike other initial settings, this may return an erorr.
1137 		 */
1138 		error = cpuset_create_root(ppr, &pr->pr_cpuset);
1139 		if (error) {
1140 			prison_deref(pr, PD_LIST_XLOCKED);
1141 			goto done_releroot;
1142 		}
1143 
1144 		mtx_lock(&pr->pr_mtx);
1145 		/*
1146 		 * New prisons do not yet have a reference, because we do not
1147 		 * want other to see the incomplete prison once the
1148 		 * allprison_lock is downgraded.
1149 		 */
1150 	} else {
1151 		created = 0;
1152 		/*
1153 		 * Grab a reference for existing prisons, to ensure they
1154 		 * continue to exist for the duration of the call.
1155 		 */
1156 		pr->pr_ref++;
1157 	}
1158 
1159 	/* Do final error checking before setting anything. */
1160 	if (gotslevel) {
1161 		if (slevel < ppr->pr_securelevel) {
1162 			error = EPERM;
1163 			goto done_deref_locked;
1164 		}
1165 	}
1166 	if (gotenforce) {
1167 		if (enforce < ppr->pr_enforce_statfs) {
1168 			error = EPERM;
1169 			goto done_deref_locked;
1170 		}
1171 	}
1172 #ifdef INET
1173 	if (ch_flags & PR_IP4_USER) {
1174 		if (ppr->pr_flags & PR_IP4) {
1175 			if (!(pr_flags & PR_IP4_USER)) {
1176 				/*
1177 				 * Silently ignore attempts to make the IP
1178 				 * addresses unrestricted when the parent is
1179 				 * restricted; in other words, interpret
1180 				 * "unrestricted" as "as unrestricted as
1181 				 * possible".
1182 				 */
1183 				ip4s = ppr->pr_ip4s;
1184 				if (ip4s == 0) {
1185 					free(ip4, M_PRISON);
1186 					ip4 = NULL;
1187 				} else if (ip4s <= ip4a) {
1188 					/* Inherit the parent's address(es). */
1189 					bcopy(ppr->pr_ip4, ip4,
1190 					    ip4s * sizeof(*ip4));
1191 				} else {
1192 					/*
1193 					 * There's no room for the parent's
1194 					 * address list.  Allocate some more.
1195 					 */
1196 					ip4a = ip4s;
1197 					free(ip4, M_PRISON);
1198 					ip4 = malloc(ip4a * sizeof(*ip4),
1199 					    M_PRISON, M_NOWAIT);
1200 					if (ip4 != NULL)
1201 						bcopy(ppr->pr_ip4, ip4,
1202 						    ip4s * sizeof(*ip4));
1203 					else {
1204 						/* Allocation failed without
1205 						 * sleeping.  Unlocking the
1206 						 * prison now will invalidate
1207 						 * some checks and prematurely
1208 						 * show an unfinished new jail.
1209 						 * So let go of everything and
1210 						 * start over.
1211 						 */
1212 						prison_deref(pr, created
1213 						    ? PD_LOCKED |
1214 						      PD_LIST_XLOCKED
1215 						    : PD_DEREF | PD_LOCKED |
1216 						      PD_LIST_XLOCKED);
1217 						if (root != NULL) {
1218 							vfslocked =
1219 							    VFS_LOCK_GIANT(
1220 							    root->v_mount);
1221 							vrele(root);
1222 							VFS_UNLOCK_GIANT(
1223 							    vfslocked);
1224 						}
1225 						ip4 = malloc(ip4a *
1226 						    sizeof(*ip4), M_PRISON,
1227 						    M_WAITOK);
1228 						goto again;
1229 					}
1230 				}
1231 			} else if (ip4s > 0) {
1232 				/*
1233 				 * Make sure the new set of IP addresses is a
1234 				 * subset of the parent's list.  Don't worry
1235 				 * about the parent being unlocked, as any
1236 				 * setting is done with allprison_lock held.
1237 				 */
1238 				for (ij = 0; ij < ppr->pr_ip4s; ij++)
1239 					if (ip4[0].s_addr ==
1240 					    ppr->pr_ip4[ij].s_addr)
1241 						break;
1242 				if (ij == ppr->pr_ip4s) {
1243 					error = EPERM;
1244 					goto done_deref_locked;
1245 				}
1246 				if (ip4s > 1) {
1247 					for (ii = ij = 1; ii < ip4s; ii++) {
1248 						if (ip4[ii].s_addr ==
1249 						    ppr->pr_ip4[0].s_addr)
1250 							continue;
1251 						for (; ij < ppr->pr_ip4s; ij++)
1252 						    if (ip4[ii].s_addr ==
1253 							ppr->pr_ip4[ij].s_addr)
1254 							    break;
1255 						if (ij == ppr->pr_ip4s)
1256 							break;
1257 					}
1258 					if (ij == ppr->pr_ip4s) {
1259 						error = EPERM;
1260 						goto done_deref_locked;
1261 					}
1262 				}
1263 			}
1264 		}
1265 		if (ip4s > 0) {
1266 			/*
1267 			 * Check for conflicting IP addresses.  We permit them
1268 			 * if there is no more than one IP on each jail.  If
1269 			 * there is a duplicate on a jail with more than one
1270 			 * IP stop checking and return error.
1271 			 */
1272 			FOREACH_PRISON_DESCENDANT(&prison0, tpr, descend) {
1273 				if (tpr == pr || tpr->pr_uref == 0) {
1274 					descend = 0;
1275 					continue;
1276 				}
1277 				if (!(tpr->pr_flags & PR_IP4_USER))
1278 					continue;
1279 				descend = 0;
1280 				if (tpr->pr_ip4 == NULL ||
1281 				    (ip4s == 1 && tpr->pr_ip4s == 1))
1282 					continue;
1283 				for (ii = 0; ii < ip4s; ii++) {
1284 					if (_prison_check_ip4(tpr,
1285 					    &ip4[ii]) == 0) {
1286 						error = EADDRINUSE;
1287 						vfs_opterror(opts,
1288 						    "IPv4 addresses clash");
1289 						goto done_deref_locked;
1290 					}
1291 				}
1292 			}
1293 		}
1294 	}
1295 #endif
1296 #ifdef INET6
1297 	if (ch_flags & PR_IP6_USER) {
1298 		if (ppr->pr_flags & PR_IP6) {
1299 			if (!(pr_flags & PR_IP6_USER)) {
1300 				/*
1301 				 * Silently ignore attempts to make the IP
1302 				 * addresses unrestricted when the parent is
1303 				 * restricted.
1304 				 */
1305 				ip6s = ppr->pr_ip6s;
1306 				if (ip6s == 0) {
1307 					free(ip6, M_PRISON);
1308 					ip6 = NULL;
1309 				} else if (ip6s <= ip6a) {
1310 					/* Inherit the parent's address(es). */
1311 					bcopy(ppr->pr_ip6, ip6,
1312 					    ip6s * sizeof(*ip6));
1313 				} else {
1314 					/*
1315 					 * There's no room for the parent's
1316 					 * address list.
1317 					 */
1318 					ip6a = ip6s;
1319 					free(ip6, M_PRISON);
1320 					ip6 = malloc(ip6a * sizeof(*ip6),
1321 					    M_PRISON, M_NOWAIT);
1322 					if (ip6 != NULL)
1323 						bcopy(ppr->pr_ip6, ip6,
1324 						    ip6s * sizeof(*ip6));
1325 					else {
1326 						prison_deref(pr, created
1327 						    ? PD_LOCKED |
1328 						      PD_LIST_XLOCKED
1329 						    : PD_DEREF | PD_LOCKED |
1330 						      PD_LIST_XLOCKED);
1331 						if (root != NULL) {
1332 							vfslocked =
1333 							    VFS_LOCK_GIANT(
1334 							    root->v_mount);
1335 							vrele(root);
1336 							VFS_UNLOCK_GIANT(
1337 							    vfslocked);
1338 						}
1339 						ip6 = malloc(ip6a *
1340 						    sizeof(*ip6), M_PRISON,
1341 						    M_WAITOK);
1342 						goto again;
1343 					}
1344 				}
1345 			} else if (ip6s > 0) {
1346 				/*
1347 				 * Make sure the new set of IP addresses is a
1348 				 * subset of the parent's list.
1349 				 */
1350 				for (ij = 0; ij < ppr->pr_ip6s; ij++)
1351 					if (IN6_ARE_ADDR_EQUAL(&ip6[0],
1352 					    &ppr->pr_ip6[ij]))
1353 						break;
1354 				if (ij == ppr->pr_ip6s) {
1355 					error = EPERM;
1356 					goto done_deref_locked;
1357 				}
1358 				if (ip6s > 1) {
1359 					for (ii = ij = 1; ii < ip6s; ii++) {
1360 						if (IN6_ARE_ADDR_EQUAL(&ip6[ii],
1361 						    &ppr->pr_ip6[0]))
1362 							continue;
1363 						for (; ij < ppr->pr_ip6s; ij++)
1364 							if (IN6_ARE_ADDR_EQUAL(
1365 							    &ip6[ii],
1366 							    &ppr->pr_ip6[ij]))
1367 								break;
1368 						if (ij == ppr->pr_ip6s)
1369 							break;
1370 					}
1371 					if (ij == ppr->pr_ip6s) {
1372 						error = EPERM;
1373 						goto done_deref_locked;
1374 					}
1375 				}
1376 			}
1377 		}
1378 		if (ip6s > 0) {
1379 			/* Check for conflicting IP addresses. */
1380 			FOREACH_PRISON_DESCENDANT(&prison0, tpr, descend) {
1381 				if (tpr == pr || tpr->pr_uref == 0) {
1382 					descend = 0;
1383 					continue;
1384 				}
1385 				if (!(tpr->pr_flags & PR_IP6_USER))
1386 					continue;
1387 				descend = 0;
1388 				if (tpr->pr_ip6 == NULL ||
1389 				    (ip6s == 1 && tpr->pr_ip6s == 1))
1390 					continue;
1391 				for (ii = 0; ii < ip6s; ii++) {
1392 					if (_prison_check_ip6(tpr,
1393 					    &ip6[ii]) == 0) {
1394 						error = EADDRINUSE;
1395 						vfs_opterror(opts,
1396 						    "IPv6 addresses clash");
1397 						goto done_deref_locked;
1398 					}
1399 				}
1400 			}
1401 		}
1402 	}
1403 #endif
1404 	onamelen = namelen = 0;
1405 	if (name != NULL) {
1406 		/* Give a default name of the jid. */
1407 		if (name[0] == '\0')
1408 			snprintf(name = numbuf, sizeof(numbuf), "%d", jid);
1409 		else if (strtoul(name, &p, 10) != jid && *p == '\0') {
1410 			error = EINVAL;
1411 			vfs_opterror(opts, "name cannot be numeric");
1412 			goto done_deref_locked;
1413 		}
1414 		/*
1415 		 * Make sure the name isn't too long for the prison or its
1416 		 * children.
1417 		 */
1418 		onamelen = strlen(pr->pr_name);
1419 		namelen = strlen(name);
1420 		if (strlen(ppr->pr_name) + namelen + 2 > sizeof(pr->pr_name)) {
1421 			error = ENAMETOOLONG;
1422 			goto done_deref_locked;
1423 		}
1424 		FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1425 			if (strlen(tpr->pr_name) + (namelen - onamelen) >=
1426 			    sizeof(pr->pr_name)) {
1427 				error = ENAMETOOLONG;
1428 				goto done_deref_locked;
1429 			}
1430 		}
1431 	}
1432 	if (pr_allow & ~ppr->pr_allow) {
1433 		error = EPERM;
1434 		goto done_deref_locked;
1435 	}
1436 
1437 	/* Set the parameters of the prison. */
1438 #ifdef INET
1439 	redo_ip4 = 0;
1440 	if (ch_flags & PR_IP4_USER) {
1441 		if (pr_flags & PR_IP4_USER) {
1442 			/* Some restriction set. */
1443 			pr->pr_flags |= PR_IP4;
1444 			if (ip4s >= 0) {
1445 				free(pr->pr_ip4, M_PRISON);
1446 				pr->pr_ip4s = ip4s;
1447 				pr->pr_ip4 = ip4;
1448 				ip4 = NULL;
1449 			}
1450 		} else if (ppr->pr_flags & PR_IP4) {
1451 			/* This restriction cleared, but keep inherited. */
1452 			free(pr->pr_ip4, M_PRISON);
1453 			pr->pr_ip4s = ip4s;
1454 			pr->pr_ip4 = ip4;
1455 			ip4 = NULL;
1456 		} else {
1457 			/* Restriction cleared, now unrestricted. */
1458 			pr->pr_flags &= ~PR_IP4;
1459 			free(pr->pr_ip4, M_PRISON);
1460 			pr->pr_ip4s = 0;
1461 		}
1462 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1463 			if (prison_restrict_ip4(tpr, NULL)) {
1464 				redo_ip4 = 1;
1465 				descend = 0;
1466 			}
1467 		}
1468 	}
1469 #endif
1470 #ifdef INET6
1471 	redo_ip6 = 0;
1472 	if (ch_flags & PR_IP6_USER) {
1473 		if (pr_flags & PR_IP6_USER) {
1474 			/* Some restriction set. */
1475 			pr->pr_flags |= PR_IP6;
1476 			if (ip6s >= 0) {
1477 				free(pr->pr_ip6, M_PRISON);
1478 				pr->pr_ip6s = ip6s;
1479 				pr->pr_ip6 = ip6;
1480 				ip6 = NULL;
1481 			}
1482 		} else if (ppr->pr_flags & PR_IP6) {
1483 			/* This restriction cleared, but keep inherited. */
1484 			free(pr->pr_ip6, M_PRISON);
1485 			pr->pr_ip6s = ip6s;
1486 			pr->pr_ip6 = ip6;
1487 			ip6 = NULL;
1488 		} else {
1489 			/* Restriction cleared, now unrestricted. */
1490 			pr->pr_flags &= ~PR_IP6;
1491 			free(pr->pr_ip6, M_PRISON);
1492 			pr->pr_ip6s = 0;
1493 		}
1494 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1495 			if (prison_restrict_ip6(tpr, NULL)) {
1496 				redo_ip6 = 1;
1497 				descend = 0;
1498 			}
1499 		}
1500 	}
1501 #endif
1502 	if (gotslevel) {
1503 		pr->pr_securelevel = slevel;
1504 		/* Set all child jails to be at least this level. */
1505 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1506 			if (tpr->pr_securelevel < slevel)
1507 				tpr->pr_securelevel = slevel;
1508 	}
1509 	if (gotenforce) {
1510 		pr->pr_enforce_statfs = enforce;
1511 		/* Pass this restriction on to the children. */
1512 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1513 			if (tpr->pr_enforce_statfs < enforce)
1514 				tpr->pr_enforce_statfs = enforce;
1515 	}
1516 	if (name != NULL) {
1517 		if (ppr == &prison0)
1518 			strlcpy(pr->pr_name, name, sizeof(pr->pr_name));
1519 		else
1520 			snprintf(pr->pr_name, sizeof(pr->pr_name), "%s.%s",
1521 			    ppr->pr_name, name);
1522 		/* Change this component of child names. */
1523 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1524 			bcopy(tpr->pr_name + onamelen, tpr->pr_name + namelen,
1525 			    strlen(tpr->pr_name + onamelen) + 1);
1526 			bcopy(pr->pr_name, tpr->pr_name, namelen);
1527 		}
1528 	}
1529 	if (path != NULL) {
1530 		/* Try to keep a real-rooted full pathname. */
1531 		if (path[0] == '/' && strcmp(mypr->pr_path, "/"))
1532 			snprintf(pr->pr_path, sizeof(pr->pr_path), "%s%s",
1533 			    mypr->pr_path, path);
1534 		else
1535 			strlcpy(pr->pr_path, path, sizeof(pr->pr_path));
1536 		pr->pr_root = root;
1537 	}
1538 	if (PR_HOST & ch_flags & ~pr_flags) {
1539 		if (pr->pr_flags & PR_HOST) {
1540 			/*
1541 			 * Copy the parent's host info.  As with pr_ip4 above,
1542 			 * the lack of a lock on the parent is not a problem;
1543 			 * it is always set with allprison_lock at least
1544 			 * shared, and is held exclusively here.
1545 			 */
1546 			strlcpy(pr->pr_hostname, pr->pr_parent->pr_hostname,
1547 			    sizeof(pr->pr_hostname));
1548 			strlcpy(pr->pr_domainname, pr->pr_parent->pr_domainname,
1549 			    sizeof(pr->pr_domainname));
1550 			strlcpy(pr->pr_hostuuid, pr->pr_parent->pr_hostuuid,
1551 			    sizeof(pr->pr_hostuuid));
1552 			pr->pr_hostid = pr->pr_parent->pr_hostid;
1553 		}
1554 	} else if (host != NULL || domain != NULL || uuid != NULL || gothid) {
1555 		/* Set this prison, and any descendants without PR_HOST. */
1556 		if (host != NULL)
1557 			strlcpy(pr->pr_hostname, host, sizeof(pr->pr_hostname));
1558 		if (domain != NULL)
1559 			strlcpy(pr->pr_domainname, domain,
1560 			    sizeof(pr->pr_domainname));
1561 		if (uuid != NULL)
1562 			strlcpy(pr->pr_hostuuid, uuid, sizeof(pr->pr_hostuuid));
1563 		if (gothid)
1564 			pr->pr_hostid = hid;
1565 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1566 			if (tpr->pr_flags & PR_HOST)
1567 				descend = 0;
1568 			else {
1569 				if (host != NULL)
1570 					strlcpy(tpr->pr_hostname,
1571 					    pr->pr_hostname,
1572 					    sizeof(tpr->pr_hostname));
1573 				if (domain != NULL)
1574 					strlcpy(tpr->pr_domainname,
1575 					    pr->pr_domainname,
1576 					    sizeof(tpr->pr_domainname));
1577 				if (uuid != NULL)
1578 					strlcpy(tpr->pr_hostuuid,
1579 					    pr->pr_hostuuid,
1580 					    sizeof(tpr->pr_hostuuid));
1581 				if (gothid)
1582 					tpr->pr_hostid = hid;
1583 			}
1584 		}
1585 	}
1586 	if ((tallow = ch_allow & ~pr_allow)) {
1587 		/* Clear allow bits in all children. */
1588 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1589 			tpr->pr_allow &= ~tallow;
1590 	}
1591 	pr->pr_allow = (pr->pr_allow & ~ch_allow) | pr_allow;
1592 	/*
1593 	 * Persistent prisons get an extra reference, and prisons losing their
1594 	 * persist flag lose that reference.  Only do this for existing prisons
1595 	 * for now, so new ones will remain unseen until after the module
1596 	 * handlers have completed.
1597 	 */
1598 	if (!created && (ch_flags & PR_PERSIST & (pr_flags ^ pr->pr_flags))) {
1599 		if (pr_flags & PR_PERSIST) {
1600 			pr->pr_ref++;
1601 			pr->pr_uref++;
1602 		} else {
1603 			pr->pr_ref--;
1604 			pr->pr_uref--;
1605 		}
1606 	}
1607 	pr->pr_flags = (pr->pr_flags & ~ch_flags) | pr_flags;
1608 	mtx_unlock(&pr->pr_mtx);
1609 
1610 	/* Locks may have prevented a complete restriction of child IP
1611 	 * addresses.  If so, allocate some more memory and try again.
1612 	 */
1613 #ifdef INET
1614 	while (redo_ip4) {
1615 		ip4s = pr->pr_ip4s;
1616 		ip4 = malloc(ip4s * sizeof(*ip4), M_PRISON, M_WAITOK);
1617 		mtx_lock(&pr->pr_mtx);
1618 		redo_ip4 = 0;
1619 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1620 			if (prison_restrict_ip4(tpr, ip4)) {
1621 				if (ip4 != NULL)
1622 					ip4 = NULL;
1623 				else
1624 					redo_ip4 = 1;
1625 			}
1626 		}
1627 		mtx_unlock(&pr->pr_mtx);
1628 	}
1629 #endif
1630 #ifdef INET6
1631 	while (redo_ip6) {
1632 		ip6s = pr->pr_ip6s;
1633 		ip6 = malloc(ip6s * sizeof(*ip6), M_PRISON, M_WAITOK);
1634 		mtx_lock(&pr->pr_mtx);
1635 		redo_ip6 = 0;
1636 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1637 			if (prison_restrict_ip6(tpr, ip6)) {
1638 				if (ip6 != NULL)
1639 					ip6 = NULL;
1640 				else
1641 					redo_ip6 = 1;
1642 			}
1643 		}
1644 		mtx_unlock(&pr->pr_mtx);
1645 	}
1646 #endif
1647 
1648 	/* Let the modules do their work. */
1649 	sx_downgrade(&allprison_lock);
1650 	if (created) {
1651 		error = osd_jail_call(pr, PR_METHOD_CREATE, opts);
1652 		if (error) {
1653 			prison_deref(pr, PD_LIST_SLOCKED);
1654 			goto done_errmsg;
1655 		}
1656 	}
1657 	error = osd_jail_call(pr, PR_METHOD_SET, opts);
1658 	if (error) {
1659 		prison_deref(pr, created
1660 		    ? PD_LIST_SLOCKED
1661 		    : PD_DEREF | PD_LIST_SLOCKED);
1662 		goto done_errmsg;
1663 	}
1664 
1665 	/* Attach this process to the prison if requested. */
1666 	if (flags & JAIL_ATTACH) {
1667 		mtx_lock(&pr->pr_mtx);
1668 		error = do_jail_attach(td, pr);
1669 		if (error) {
1670 			vfs_opterror(opts, "attach failed");
1671 			if (!created)
1672 				prison_deref(pr, PD_DEREF);
1673 			goto done_errmsg;
1674 		}
1675 	}
1676 
1677 	/*
1678 	 * Now that it is all there, drop the temporary reference from existing
1679 	 * prisons.  Or add a reference to newly created persistent prisons
1680 	 * (which was not done earlier so that the prison would not be publicly
1681 	 * visible).
1682 	 */
1683 	if (!created) {
1684 		prison_deref(pr, (flags & JAIL_ATTACH)
1685 		    ? PD_DEREF
1686 		    : PD_DEREF | PD_LIST_SLOCKED);
1687 	} else {
1688 		if (pr_flags & PR_PERSIST) {
1689 			mtx_lock(&pr->pr_mtx);
1690 			pr->pr_ref++;
1691 			pr->pr_uref++;
1692 			mtx_unlock(&pr->pr_mtx);
1693 		}
1694 		if (!(flags & JAIL_ATTACH))
1695 			sx_sunlock(&allprison_lock);
1696 	}
1697 	td->td_retval[0] = pr->pr_id;
1698 	goto done_errmsg;
1699 
1700  done_deref_locked:
1701 	prison_deref(pr, created
1702 	    ? PD_LOCKED | PD_LIST_XLOCKED
1703 	    : PD_DEREF | PD_LOCKED | PD_LIST_XLOCKED);
1704 	goto done_releroot;
1705  done_unlock_list:
1706 	sx_xunlock(&allprison_lock);
1707  done_releroot:
1708 	if (root != NULL) {
1709 		vfslocked = VFS_LOCK_GIANT(root->v_mount);
1710 		vrele(root);
1711 		VFS_UNLOCK_GIANT(vfslocked);
1712 	}
1713  done_errmsg:
1714 	if (error) {
1715 		vfs_getopt(opts, "errmsg", (void **)&errmsg, &errmsg_len);
1716 		if (errmsg_len > 0) {
1717 			errmsg_pos = 2 * vfs_getopt_pos(opts, "errmsg") + 1;
1718 			if (errmsg_pos > 0) {
1719 				if (optuio->uio_segflg == UIO_SYSSPACE)
1720 					bcopy(errmsg,
1721 					   optuio->uio_iov[errmsg_pos].iov_base,
1722 					   errmsg_len);
1723 				else
1724 					copyout(errmsg,
1725 					   optuio->uio_iov[errmsg_pos].iov_base,
1726 					   errmsg_len);
1727 			}
1728 		}
1729 	}
1730  done_free:
1731 #ifdef INET
1732 	free(ip4, M_PRISON);
1733 #endif
1734 #ifdef INET6
1735 	free(ip6, M_PRISON);
1736 #endif
1737 	vfs_freeopts(opts);
1738 	return (error);
1739 }
1740 
1741 
1742 /*
1743  * struct jail_get_args {
1744  *	struct iovec *iovp;
1745  *	unsigned int iovcnt;
1746  *	int flags;
1747  * };
1748  */
1749 int
1750 jail_get(struct thread *td, struct jail_get_args *uap)
1751 {
1752 	struct uio *auio;
1753 	int error;
1754 
1755 	/* Check that we have an even number of iovecs. */
1756 	if (uap->iovcnt & 1)
1757 		return (EINVAL);
1758 
1759 	error = copyinuio(uap->iovp, uap->iovcnt, &auio);
1760 	if (error)
1761 		return (error);
1762 	error = kern_jail_get(td, auio, uap->flags);
1763 	if (error == 0)
1764 		error = copyout(auio->uio_iov, uap->iovp,
1765 		    uap->iovcnt * sizeof (struct iovec));
1766 	free(auio, M_IOV);
1767 	return (error);
1768 }
1769 
1770 int
1771 kern_jail_get(struct thread *td, struct uio *optuio, int flags)
1772 {
1773 	struct prison *pr, *mypr;
1774 	struct vfsopt *opt;
1775 	struct vfsoptlist *opts;
1776 	char *errmsg, *name;
1777 	int error, errmsg_len, errmsg_pos, fi, i, jid, len, locked, pos;
1778 
1779 	if (flags & ~JAIL_GET_MASK)
1780 		return (EINVAL);
1781 
1782 	/* Get the parameter list. */
1783 	error = vfs_buildopts(optuio, &opts);
1784 	if (error)
1785 		return (error);
1786 	errmsg_pos = vfs_getopt_pos(opts, "errmsg");
1787 	mypr = td->td_ucred->cr_prison;
1788 
1789 	/*
1790 	 * Find the prison specified by one of: lastjid, jid, name.
1791 	 */
1792 	sx_slock(&allprison_lock);
1793 	error = vfs_copyopt(opts, "lastjid", &jid, sizeof(jid));
1794 	if (error == 0) {
1795 		TAILQ_FOREACH(pr, &allprison, pr_list) {
1796 			if (pr->pr_id > jid && prison_ischild(mypr, pr)) {
1797 				mtx_lock(&pr->pr_mtx);
1798 				if (pr->pr_ref > 0 &&
1799 				    (pr->pr_uref > 0 || (flags & JAIL_DYING)))
1800 					break;
1801 				mtx_unlock(&pr->pr_mtx);
1802 			}
1803 		}
1804 		if (pr != NULL)
1805 			goto found_prison;
1806 		error = ENOENT;
1807 		vfs_opterror(opts, "no jail after %d", jid);
1808 		goto done_unlock_list;
1809 	} else if (error != ENOENT)
1810 		goto done_unlock_list;
1811 
1812 	error = vfs_copyopt(opts, "jid", &jid, sizeof(jid));
1813 	if (error == 0) {
1814 		if (jid != 0) {
1815 			pr = prison_find_child(mypr, jid);
1816 			if (pr != NULL) {
1817 				if (pr->pr_uref == 0 && !(flags & JAIL_DYING)) {
1818 					mtx_unlock(&pr->pr_mtx);
1819 					error = ENOENT;
1820 					vfs_opterror(opts, "jail %d is dying",
1821 					    jid);
1822 					goto done_unlock_list;
1823 				}
1824 				goto found_prison;
1825 			}
1826 			error = ENOENT;
1827 			vfs_opterror(opts, "jail %d not found", jid);
1828 			goto done_unlock_list;
1829 		}
1830 	} else if (error != ENOENT)
1831 		goto done_unlock_list;
1832 
1833 	error = vfs_getopt(opts, "name", (void **)&name, &len);
1834 	if (error == 0) {
1835 		if (len == 0 || name[len - 1] != '\0') {
1836 			error = EINVAL;
1837 			goto done_unlock_list;
1838 		}
1839 		pr = prison_find_name(mypr, name);
1840 		if (pr != NULL) {
1841 			if (pr->pr_uref == 0 && !(flags & JAIL_DYING)) {
1842 				mtx_unlock(&pr->pr_mtx);
1843 				error = ENOENT;
1844 				vfs_opterror(opts, "jail \"%s\" is dying",
1845 				    name);
1846 				goto done_unlock_list;
1847 			}
1848 			goto found_prison;
1849 		}
1850 		error = ENOENT;
1851 		vfs_opterror(opts, "jail \"%s\" not found", name);
1852 		goto done_unlock_list;
1853 	} else if (error != ENOENT)
1854 		goto done_unlock_list;
1855 
1856 	vfs_opterror(opts, "no jail specified");
1857 	error = ENOENT;
1858 	goto done_unlock_list;
1859 
1860  found_prison:
1861 	/* Get the parameters of the prison. */
1862 	pr->pr_ref++;
1863 	locked = PD_LOCKED;
1864 	td->td_retval[0] = pr->pr_id;
1865 	error = vfs_setopt(opts, "jid", &pr->pr_id, sizeof(pr->pr_id));
1866 	if (error != 0 && error != ENOENT)
1867 		goto done_deref;
1868 	i = (pr->pr_parent == mypr) ? 0 : pr->pr_parent->pr_id;
1869 	error = vfs_setopt(opts, "parent", &i, sizeof(i));
1870 	if (error != 0 && error != ENOENT)
1871 		goto done_deref;
1872 	error = vfs_setopts(opts, "name", prison_name(mypr, pr));
1873 	if (error != 0 && error != ENOENT)
1874 		goto done_deref;
1875 	error = vfs_setopt(opts, "cpuset.id", &pr->pr_cpuset->cs_id,
1876 	    sizeof(pr->pr_cpuset->cs_id));
1877 	if (error != 0 && error != ENOENT)
1878 		goto done_deref;
1879 	error = vfs_setopts(opts, "path", prison_path(mypr, pr));
1880 	if (error != 0 && error != ENOENT)
1881 		goto done_deref;
1882 #ifdef INET
1883 	error = vfs_setopt_part(opts, "ip4.addr", pr->pr_ip4,
1884 	    pr->pr_ip4s * sizeof(*pr->pr_ip4));
1885 	if (error != 0 && error != ENOENT)
1886 		goto done_deref;
1887 #endif
1888 #ifdef INET6
1889 	error = vfs_setopt_part(opts, "ip6.addr", pr->pr_ip6,
1890 	    pr->pr_ip6s * sizeof(*pr->pr_ip6));
1891 	if (error != 0 && error != ENOENT)
1892 		goto done_deref;
1893 #endif
1894 	error = vfs_setopt(opts, "securelevel", &pr->pr_securelevel,
1895 	    sizeof(pr->pr_securelevel));
1896 	if (error != 0 && error != ENOENT)
1897 		goto done_deref;
1898 	error = vfs_setopts(opts, "host.hostname", pr->pr_hostname);
1899 	if (error != 0 && error != ENOENT)
1900 		goto done_deref;
1901 	error = vfs_setopts(opts, "host.domainname", pr->pr_domainname);
1902 	if (error != 0 && error != ENOENT)
1903 		goto done_deref;
1904 	error = vfs_setopts(opts, "host.hostuuid", pr->pr_hostuuid);
1905 	if (error != 0 && error != ENOENT)
1906 		goto done_deref;
1907 #ifdef COMPAT_IA32
1908 	if (td->td_proc->p_sysent->sv_flags & SV_IA32) {
1909 		uint32_t hid32 = pr->pr_hostid;
1910 
1911 		error = vfs_setopt(opts, "host.hostid", &hid32, sizeof(hid32));
1912 	} else
1913 #endif
1914 	error = vfs_setopt(opts, "host.hostid", &pr->pr_hostid,
1915 	    sizeof(pr->pr_hostid));
1916 	if (error != 0 && error != ENOENT)
1917 		goto done_deref;
1918 	error = vfs_setopt(opts, "enforce_statfs", &pr->pr_enforce_statfs,
1919 	    sizeof(pr->pr_enforce_statfs));
1920 	if (error != 0 && error != ENOENT)
1921 		goto done_deref;
1922 	for (fi = 0; fi < sizeof(pr_flag_names) / sizeof(pr_flag_names[0]);
1923 	    fi++) {
1924 		if (pr_flag_names[fi] == NULL)
1925 			continue;
1926 		i = (pr->pr_flags & (1 << fi)) ? 1 : 0;
1927 		error = vfs_setopt(opts, pr_flag_names[fi], &i, sizeof(i));
1928 		if (error != 0 && error != ENOENT)
1929 			goto done_deref;
1930 		i = !i;
1931 		error = vfs_setopt(opts, pr_flag_nonames[fi], &i, sizeof(i));
1932 		if (error != 0 && error != ENOENT)
1933 			goto done_deref;
1934 	}
1935 	for (fi = 0; fi < sizeof(pr_allow_names) / sizeof(pr_allow_names[0]);
1936 	    fi++) {
1937 		if (pr_allow_names[fi] == NULL)
1938 			continue;
1939 		i = (pr->pr_allow & (1 << fi)) ? 1 : 0;
1940 		error = vfs_setopt(opts, pr_allow_names[fi], &i, sizeof(i));
1941 		if (error != 0 && error != ENOENT)
1942 			goto done_deref;
1943 		i = !i;
1944 		error = vfs_setopt(opts, pr_allow_nonames[fi], &i, sizeof(i));
1945 		if (error != 0 && error != ENOENT)
1946 			goto done_deref;
1947 	}
1948 	i = (pr->pr_uref == 0);
1949 	error = vfs_setopt(opts, "dying", &i, sizeof(i));
1950 	if (error != 0 && error != ENOENT)
1951 		goto done_deref;
1952 	i = !i;
1953 	error = vfs_setopt(opts, "nodying", &i, sizeof(i));
1954 	if (error != 0 && error != ENOENT)
1955 		goto done_deref;
1956 
1957 	/* Get the module parameters. */
1958 	mtx_unlock(&pr->pr_mtx);
1959 	locked = 0;
1960 	error = osd_jail_call(pr, PR_METHOD_GET, opts);
1961 	if (error)
1962 		goto done_deref;
1963 	prison_deref(pr, PD_DEREF | PD_LIST_SLOCKED);
1964 
1965 	/* By now, all parameters should have been noted. */
1966 	TAILQ_FOREACH(opt, opts, link) {
1967 		if (!opt->seen && strcmp(opt->name, "errmsg")) {
1968 			error = EINVAL;
1969 			vfs_opterror(opts, "unknown parameter: %s", opt->name);
1970 			goto done_errmsg;
1971 		}
1972 	}
1973 
1974 	/* Write the fetched parameters back to userspace. */
1975 	error = 0;
1976 	TAILQ_FOREACH(opt, opts, link) {
1977 		if (opt->pos >= 0 && opt->pos != errmsg_pos) {
1978 			pos = 2 * opt->pos + 1;
1979 			optuio->uio_iov[pos].iov_len = opt->len;
1980 			if (opt->value != NULL) {
1981 				if (optuio->uio_segflg == UIO_SYSSPACE) {
1982 					bcopy(opt->value,
1983 					    optuio->uio_iov[pos].iov_base,
1984 					    opt->len);
1985 				} else {
1986 					error = copyout(opt->value,
1987 					    optuio->uio_iov[pos].iov_base,
1988 					    opt->len);
1989 					if (error)
1990 						break;
1991 				}
1992 			}
1993 		}
1994 	}
1995 	goto done_errmsg;
1996 
1997  done_deref:
1998 	prison_deref(pr, locked | PD_DEREF | PD_LIST_SLOCKED);
1999 	goto done_errmsg;
2000 
2001  done_unlock_list:
2002 	sx_sunlock(&allprison_lock);
2003  done_errmsg:
2004 	if (error && errmsg_pos >= 0) {
2005 		vfs_getopt(opts, "errmsg", (void **)&errmsg, &errmsg_len);
2006 		errmsg_pos = 2 * errmsg_pos + 1;
2007 		if (errmsg_len > 0) {
2008 			if (optuio->uio_segflg == UIO_SYSSPACE)
2009 				bcopy(errmsg,
2010 				    optuio->uio_iov[errmsg_pos].iov_base,
2011 				    errmsg_len);
2012 			else
2013 				copyout(errmsg,
2014 				    optuio->uio_iov[errmsg_pos].iov_base,
2015 				    errmsg_len);
2016 		}
2017 	}
2018 	vfs_freeopts(opts);
2019 	return (error);
2020 }
2021 
2022 
2023 /*
2024  * struct jail_remove_args {
2025  *	int jid;
2026  * };
2027  */
2028 int
2029 jail_remove(struct thread *td, struct jail_remove_args *uap)
2030 {
2031 	struct prison *pr, *cpr, *lpr, *tpr;
2032 	int descend, error;
2033 
2034 	error = priv_check(td, PRIV_JAIL_REMOVE);
2035 	if (error)
2036 		return (error);
2037 
2038 	sx_xlock(&allprison_lock);
2039 	pr = prison_find_child(td->td_ucred->cr_prison, uap->jid);
2040 	if (pr == NULL) {
2041 		sx_xunlock(&allprison_lock);
2042 		return (EINVAL);
2043 	}
2044 
2045 	/* Remove all descendants of this prison, then remove this prison. */
2046 	pr->pr_ref++;
2047 	pr->pr_flags |= PR_REMOVE;
2048 	if (!LIST_EMPTY(&pr->pr_children)) {
2049 		mtx_unlock(&pr->pr_mtx);
2050 		lpr = NULL;
2051 		FOREACH_PRISON_DESCENDANT(pr, cpr, descend) {
2052 			mtx_lock(&cpr->pr_mtx);
2053 			if (cpr->pr_ref > 0) {
2054 				tpr = cpr;
2055 				cpr->pr_ref++;
2056 				cpr->pr_flags |= PR_REMOVE;
2057 			} else {
2058 				/* Already removed - do not do it again. */
2059 				tpr = NULL;
2060 			}
2061 			mtx_unlock(&cpr->pr_mtx);
2062 			if (lpr != NULL) {
2063 				mtx_lock(&lpr->pr_mtx);
2064 				prison_remove_one(lpr);
2065 				sx_xlock(&allprison_lock);
2066 			}
2067 			lpr = tpr;
2068 		}
2069 		if (lpr != NULL) {
2070 			mtx_lock(&lpr->pr_mtx);
2071 			prison_remove_one(lpr);
2072 			sx_xlock(&allprison_lock);
2073 		}
2074 		mtx_lock(&pr->pr_mtx);
2075 	}
2076 	prison_remove_one(pr);
2077 	return (0);
2078 }
2079 
2080 static void
2081 prison_remove_one(struct prison *pr)
2082 {
2083 	struct proc *p;
2084 	int deuref;
2085 
2086 	/* If the prison was persistent, it is not anymore. */
2087 	deuref = 0;
2088 	if (pr->pr_flags & PR_PERSIST) {
2089 		pr->pr_ref--;
2090 		deuref = PD_DEUREF;
2091 		pr->pr_flags &= ~PR_PERSIST;
2092 	}
2093 
2094 	/*
2095 	 * jail_remove added a reference.  If that's the only one, remove
2096 	 * the prison now.
2097 	 */
2098 	KASSERT(pr->pr_ref > 0,
2099 	    ("prison_remove_one removing a dead prison (jid=%d)", pr->pr_id));
2100 	if (pr->pr_ref == 1) {
2101 		prison_deref(pr,
2102 		    deuref | PD_DEREF | PD_LOCKED | PD_LIST_XLOCKED);
2103 		return;
2104 	}
2105 
2106 	mtx_unlock(&pr->pr_mtx);
2107 	sx_xunlock(&allprison_lock);
2108 	/*
2109 	 * Kill all processes unfortunate enough to be attached to this prison.
2110 	 */
2111 	sx_slock(&allproc_lock);
2112 	LIST_FOREACH(p, &allproc, p_list) {
2113 		PROC_LOCK(p);
2114 		if (p->p_state != PRS_NEW && p->p_ucred &&
2115 		    p->p_ucred->cr_prison == pr)
2116 			psignal(p, SIGKILL);
2117 		PROC_UNLOCK(p);
2118 	}
2119 	sx_sunlock(&allproc_lock);
2120 	/* Remove the temporary reference added by jail_remove. */
2121 	prison_deref(pr, deuref | PD_DEREF);
2122 }
2123 
2124 
2125 /*
2126  * struct jail_attach_args {
2127  *	int jid;
2128  * };
2129  */
2130 int
2131 jail_attach(struct thread *td, struct jail_attach_args *uap)
2132 {
2133 	struct prison *pr;
2134 	int error;
2135 
2136 	error = priv_check(td, PRIV_JAIL_ATTACH);
2137 	if (error)
2138 		return (error);
2139 
2140 	sx_slock(&allprison_lock);
2141 	pr = prison_find_child(td->td_ucred->cr_prison, uap->jid);
2142 	if (pr == NULL) {
2143 		sx_sunlock(&allprison_lock);
2144 		return (EINVAL);
2145 	}
2146 
2147 	/*
2148 	 * Do not allow a process to attach to a prison that is not
2149 	 * considered to be "alive".
2150 	 */
2151 	if (pr->pr_uref == 0) {
2152 		mtx_unlock(&pr->pr_mtx);
2153 		sx_sunlock(&allprison_lock);
2154 		return (EINVAL);
2155 	}
2156 
2157 	return (do_jail_attach(td, pr));
2158 }
2159 
2160 static int
2161 do_jail_attach(struct thread *td, struct prison *pr)
2162 {
2163 	struct prison *ppr;
2164 	struct proc *p;
2165 	struct ucred *newcred, *oldcred;
2166 	int vfslocked, error;
2167 
2168 	/*
2169 	 * XXX: Note that there is a slight race here if two threads
2170 	 * in the same privileged process attempt to attach to two
2171 	 * different jails at the same time.  It is important for
2172 	 * user processes not to do this, or they might end up with
2173 	 * a process root from one prison, but attached to the jail
2174 	 * of another.
2175 	 */
2176 	pr->pr_ref++;
2177 	pr->pr_uref++;
2178 	mtx_unlock(&pr->pr_mtx);
2179 
2180 	/* Let modules do whatever they need to prepare for attaching. */
2181 	error = osd_jail_call(pr, PR_METHOD_ATTACH, td);
2182 	if (error) {
2183 		prison_deref(pr, PD_DEREF | PD_DEUREF | PD_LIST_SLOCKED);
2184 		return (error);
2185 	}
2186 	sx_sunlock(&allprison_lock);
2187 
2188 	/*
2189 	 * Reparent the newly attached process to this jail.
2190 	 */
2191 	ppr = td->td_ucred->cr_prison;
2192 	p = td->td_proc;
2193 	error = cpuset_setproc_update_set(p, pr->pr_cpuset);
2194 	if (error)
2195 		goto e_revert_osd;
2196 
2197 	vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
2198 	vn_lock(pr->pr_root, LK_EXCLUSIVE | LK_RETRY);
2199 	if ((error = change_dir(pr->pr_root, td)) != 0)
2200 		goto e_unlock;
2201 #ifdef MAC
2202 	if ((error = mac_vnode_check_chroot(td->td_ucred, pr->pr_root)))
2203 		goto e_unlock;
2204 #endif
2205 	VOP_UNLOCK(pr->pr_root, 0);
2206 	if ((error = change_root(pr->pr_root, td)))
2207 		goto e_unlock_giant;
2208 	VFS_UNLOCK_GIANT(vfslocked);
2209 
2210 	newcred = crget();
2211 	PROC_LOCK(p);
2212 	oldcred = p->p_ucred;
2213 	setsugid(p);
2214 	crcopy(newcred, oldcred);
2215 	newcred->cr_prison = pr;
2216 	p->p_ucred = newcred;
2217 	PROC_UNLOCK(p);
2218 	crfree(oldcred);
2219 	prison_deref(ppr, PD_DEREF | PD_DEUREF);
2220 	return (0);
2221  e_unlock:
2222 	VOP_UNLOCK(pr->pr_root, 0);
2223  e_unlock_giant:
2224 	VFS_UNLOCK_GIANT(vfslocked);
2225  e_revert_osd:
2226 	/* Tell modules this thread is still in its old jail after all. */
2227 	(void)osd_jail_call(ppr, PR_METHOD_ATTACH, td);
2228 	prison_deref(pr, PD_DEREF | PD_DEUREF);
2229 	return (error);
2230 }
2231 
2232 
2233 /*
2234  * Returns a locked prison instance, or NULL on failure.
2235  */
2236 struct prison *
2237 prison_find(int prid)
2238 {
2239 	struct prison *pr;
2240 
2241 	sx_assert(&allprison_lock, SX_LOCKED);
2242 	TAILQ_FOREACH(pr, &allprison, pr_list) {
2243 		if (pr->pr_id == prid) {
2244 			mtx_lock(&pr->pr_mtx);
2245 			if (pr->pr_ref > 0)
2246 				return (pr);
2247 			mtx_unlock(&pr->pr_mtx);
2248 		}
2249 	}
2250 	return (NULL);
2251 }
2252 
2253 /*
2254  * Find a prison that is a descendant of mypr.  Returns a locked prison or NULL.
2255  */
2256 struct prison *
2257 prison_find_child(struct prison *mypr, int prid)
2258 {
2259 	struct prison *pr;
2260 	int descend;
2261 
2262 	sx_assert(&allprison_lock, SX_LOCKED);
2263 	FOREACH_PRISON_DESCENDANT(mypr, pr, descend) {
2264 		if (pr->pr_id == prid) {
2265 			mtx_lock(&pr->pr_mtx);
2266 			if (pr->pr_ref > 0)
2267 				return (pr);
2268 			mtx_unlock(&pr->pr_mtx);
2269 		}
2270 	}
2271 	return (NULL);
2272 }
2273 
2274 /*
2275  * Look for the name relative to mypr.  Returns a locked prison or NULL.
2276  */
2277 struct prison *
2278 prison_find_name(struct prison *mypr, const char *name)
2279 {
2280 	struct prison *pr, *deadpr;
2281 	size_t mylen;
2282 	int descend;
2283 
2284 	sx_assert(&allprison_lock, SX_LOCKED);
2285 	mylen = (mypr == &prison0) ? 0 : strlen(mypr->pr_name) + 1;
2286  again:
2287 	deadpr = NULL;
2288 	FOREACH_PRISON_DESCENDANT(mypr, pr, descend) {
2289 		if (!strcmp(pr->pr_name + mylen, name)) {
2290 			mtx_lock(&pr->pr_mtx);
2291 			if (pr->pr_ref > 0) {
2292 				if (pr->pr_uref > 0)
2293 					return (pr);
2294 				deadpr = pr;
2295 			}
2296 			mtx_unlock(&pr->pr_mtx);
2297 		}
2298 	}
2299 	/* There was no valid prison - perhaps there was a dying one. */
2300 	if (deadpr != NULL) {
2301 		mtx_lock(&deadpr->pr_mtx);
2302 		if (deadpr->pr_ref == 0) {
2303 			mtx_unlock(&deadpr->pr_mtx);
2304 			goto again;
2305 		}
2306 	}
2307 	return (deadpr);
2308 }
2309 
2310 /*
2311  * See if a prison has the specific flag set.
2312  */
2313 int
2314 prison_flag(struct ucred *cred, unsigned flag)
2315 {
2316 
2317 	/* This is an atomic read, so no locking is necessary. */
2318 	return (cred->cr_prison->pr_flags & flag);
2319 }
2320 
2321 int
2322 prison_allow(struct ucred *cred, unsigned flag)
2323 {
2324 
2325 	/* This is an atomic read, so no locking is necessary. */
2326 	return (cred->cr_prison->pr_allow & flag);
2327 }
2328 
2329 /*
2330  * Remove a prison reference.  If that was the last reference, remove the
2331  * prison itself - but not in this context in case there are locks held.
2332  */
2333 void
2334 prison_free_locked(struct prison *pr)
2335 {
2336 
2337 	mtx_assert(&pr->pr_mtx, MA_OWNED);
2338 	pr->pr_ref--;
2339 	if (pr->pr_ref == 0) {
2340 		mtx_unlock(&pr->pr_mtx);
2341 		TASK_INIT(&pr->pr_task, 0, prison_complete, pr);
2342 		taskqueue_enqueue(taskqueue_thread, &pr->pr_task);
2343 		return;
2344 	}
2345 	mtx_unlock(&pr->pr_mtx);
2346 }
2347 
2348 void
2349 prison_free(struct prison *pr)
2350 {
2351 
2352 	mtx_lock(&pr->pr_mtx);
2353 	prison_free_locked(pr);
2354 }
2355 
2356 static void
2357 prison_complete(void *context, int pending)
2358 {
2359 
2360 	prison_deref((struct prison *)context, 0);
2361 }
2362 
2363 /*
2364  * Remove a prison reference (usually).  This internal version assumes no
2365  * mutexes are held, except perhaps the prison itself.  If there are no more
2366  * references, release and delist the prison.  On completion, the prison lock
2367  * and the allprison lock are both unlocked.
2368  */
2369 static void
2370 prison_deref(struct prison *pr, int flags)
2371 {
2372 	struct prison *ppr, *tpr;
2373 	int vfslocked;
2374 
2375 	if (!(flags & PD_LOCKED))
2376 		mtx_lock(&pr->pr_mtx);
2377 	/* Decrement the user references in a separate loop. */
2378 	if (flags & PD_DEUREF) {
2379 		for (tpr = pr;; tpr = tpr->pr_parent) {
2380 			if (tpr != pr)
2381 				mtx_lock(&tpr->pr_mtx);
2382 			if (--tpr->pr_uref > 0)
2383 				break;
2384 			KASSERT(tpr != &prison0, ("prison0 pr_uref=0"));
2385 			mtx_unlock(&tpr->pr_mtx);
2386 		}
2387 		/* Done if there were only user references to remove. */
2388 		if (!(flags & PD_DEREF)) {
2389 			mtx_unlock(&tpr->pr_mtx);
2390 			if (flags & PD_LIST_SLOCKED)
2391 				sx_sunlock(&allprison_lock);
2392 			else if (flags & PD_LIST_XLOCKED)
2393 				sx_xunlock(&allprison_lock);
2394 			return;
2395 		}
2396 		if (tpr != pr) {
2397 			mtx_unlock(&tpr->pr_mtx);
2398 			mtx_lock(&pr->pr_mtx);
2399 		}
2400 	}
2401 
2402 	for (;;) {
2403 		if (flags & PD_DEREF)
2404 			pr->pr_ref--;
2405 		/* If the prison still has references, nothing else to do. */
2406 		if (pr->pr_ref > 0) {
2407 			mtx_unlock(&pr->pr_mtx);
2408 			if (flags & PD_LIST_SLOCKED)
2409 				sx_sunlock(&allprison_lock);
2410 			else if (flags & PD_LIST_XLOCKED)
2411 				sx_xunlock(&allprison_lock);
2412 			return;
2413 		}
2414 
2415 		mtx_unlock(&pr->pr_mtx);
2416 		if (flags & PD_LIST_SLOCKED) {
2417 			if (!sx_try_upgrade(&allprison_lock)) {
2418 				sx_sunlock(&allprison_lock);
2419 				sx_xlock(&allprison_lock);
2420 			}
2421 		} else if (!(flags & PD_LIST_XLOCKED))
2422 			sx_xlock(&allprison_lock);
2423 
2424 		TAILQ_REMOVE(&allprison, pr, pr_list);
2425 		LIST_REMOVE(pr, pr_sibling);
2426 		ppr = pr->pr_parent;
2427 		for (tpr = ppr; tpr != NULL; tpr = tpr->pr_parent)
2428 			tpr->pr_prisoncount--;
2429 		sx_downgrade(&allprison_lock);
2430 
2431 #ifdef VIMAGE
2432 		if (pr->pr_flags & PR_VNET)
2433 			vnet_destroy(pr->pr_vnet);
2434 #endif
2435 		if (pr->pr_root != NULL) {
2436 			vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
2437 			vrele(pr->pr_root);
2438 			VFS_UNLOCK_GIANT(vfslocked);
2439 		}
2440 		mtx_destroy(&pr->pr_mtx);
2441 #ifdef INET
2442 		free(pr->pr_ip4, M_PRISON);
2443 #endif
2444 #ifdef INET6
2445 		free(pr->pr_ip6, M_PRISON);
2446 #endif
2447 		if (pr->pr_cpuset != NULL)
2448 			cpuset_rel(pr->pr_cpuset);
2449 		osd_jail_exit(pr);
2450 		free(pr, M_PRISON);
2451 
2452 		/* Removing a prison frees a reference on its parent. */
2453 		pr = ppr;
2454 		mtx_lock(&pr->pr_mtx);
2455 		flags = PD_DEREF | PD_LIST_SLOCKED;
2456 	}
2457 }
2458 
2459 void
2460 prison_hold_locked(struct prison *pr)
2461 {
2462 
2463 	mtx_assert(&pr->pr_mtx, MA_OWNED);
2464 	KASSERT(pr->pr_ref > 0,
2465 	    ("Trying to hold dead prison (jid=%d).", pr->pr_id));
2466 	pr->pr_ref++;
2467 }
2468 
2469 void
2470 prison_hold(struct prison *pr)
2471 {
2472 
2473 	mtx_lock(&pr->pr_mtx);
2474 	prison_hold_locked(pr);
2475 	mtx_unlock(&pr->pr_mtx);
2476 }
2477 
2478 void
2479 prison_proc_hold(struct prison *pr)
2480 {
2481 
2482 	mtx_lock(&pr->pr_mtx);
2483 	KASSERT(pr->pr_uref > 0,
2484 	    ("Cannot add a process to a non-alive prison (jid=%d)", pr->pr_id));
2485 	pr->pr_uref++;
2486 	mtx_unlock(&pr->pr_mtx);
2487 }
2488 
2489 void
2490 prison_proc_free(struct prison *pr)
2491 {
2492 
2493 	mtx_lock(&pr->pr_mtx);
2494 	KASSERT(pr->pr_uref > 0,
2495 	    ("Trying to kill a process in a dead prison (jid=%d)", pr->pr_id));
2496 	prison_deref(pr, PD_DEUREF | PD_LOCKED);
2497 }
2498 
2499 
2500 #ifdef INET
2501 /*
2502  * Restrict a prison's IP address list with its parent's, possibly replacing
2503  * it.  Return true if the replacement buffer was used (or would have been).
2504  */
2505 static int
2506 prison_restrict_ip4(struct prison *pr, struct in_addr *newip4)
2507 {
2508 	int ii, ij, used;
2509 	struct prison *ppr;
2510 
2511 	ppr = pr->pr_parent;
2512 	if (!(pr->pr_flags & PR_IP4_USER)) {
2513 		/* This has no user settings, so just copy the parent's list. */
2514 		if (pr->pr_ip4s < ppr->pr_ip4s) {
2515 			/*
2516 			 * There's no room for the parent's list.  Use the
2517 			 * new list buffer, which is assumed to be big enough
2518 			 * (if it was passed).  If there's no buffer, try to
2519 			 * allocate one.
2520 			 */
2521 			used = 1;
2522 			if (newip4 == NULL) {
2523 				newip4 = malloc(ppr->pr_ip4s * sizeof(*newip4),
2524 				    M_PRISON, M_NOWAIT);
2525 				if (newip4 != NULL)
2526 					used = 0;
2527 			}
2528 			if (newip4 != NULL) {
2529 				bcopy(ppr->pr_ip4, newip4,
2530 				    ppr->pr_ip4s * sizeof(*newip4));
2531 				free(pr->pr_ip4, M_PRISON);
2532 				pr->pr_ip4 = newip4;
2533 				pr->pr_ip4s = ppr->pr_ip4s;
2534 				pr->pr_flags |= PR_IP4;
2535 			}
2536 			return (used);
2537 		}
2538 		pr->pr_ip4s = ppr->pr_ip4s;
2539 		if (pr->pr_ip4s > 0)
2540 			bcopy(ppr->pr_ip4, pr->pr_ip4,
2541 			    pr->pr_ip4s * sizeof(*newip4));
2542 		else if (pr->pr_ip4 != NULL) {
2543 			free(pr->pr_ip4, M_PRISON);
2544 			pr->pr_ip4 = NULL;
2545 		}
2546 		pr->pr_flags =
2547 			(pr->pr_flags & ~PR_IP4) | (ppr->pr_flags & PR_IP4);
2548 	} else if (pr->pr_ip4s > 0 && (ppr->pr_flags & PR_IP4)) {
2549 		/* Remove addresses that aren't in the parent. */
2550 		for (ij = 0; ij < ppr->pr_ip4s; ij++)
2551 			if (pr->pr_ip4[0].s_addr == ppr->pr_ip4[ij].s_addr)
2552 				break;
2553 		if (ij < ppr->pr_ip4s)
2554 			ii = 1;
2555 		else {
2556 			bcopy(pr->pr_ip4 + 1, pr->pr_ip4,
2557 			    --pr->pr_ip4s * sizeof(*pr->pr_ip4));
2558 			ii = 0;
2559 		}
2560 		for (ij = 1; ii < pr->pr_ip4s; ) {
2561 			if (pr->pr_ip4[ii].s_addr == ppr->pr_ip4[0].s_addr) {
2562 				ii++;
2563 				continue;
2564 			}
2565 			switch (ij >= ppr->pr_ip4s ? -1 :
2566 				qcmp_v4(&pr->pr_ip4[ii], &ppr->pr_ip4[ij])) {
2567 			case -1:
2568 				bcopy(pr->pr_ip4 + ii + 1, pr->pr_ip4 + ii,
2569 				    (--pr->pr_ip4s - ii) * sizeof(*pr->pr_ip4));
2570 				break;
2571 			case 0:
2572 				ii++;
2573 				ij++;
2574 				break;
2575 			case 1:
2576 				ij++;
2577 				break;
2578 			}
2579 		}
2580 		if (pr->pr_ip4s == 0) {
2581 			free(pr->pr_ip4, M_PRISON);
2582 			pr->pr_ip4 = NULL;
2583 		}
2584 	}
2585 	return (0);
2586 }
2587 
2588 /*
2589  * Pass back primary IPv4 address of this jail.
2590  *
2591  * If not restricted return success but do not alter the address.  Caller has
2592  * to make sure to initialize it correctly (e.g. INADDR_ANY).
2593  *
2594  * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
2595  * Address returned in NBO.
2596  */
2597 int
2598 prison_get_ip4(struct ucred *cred, struct in_addr *ia)
2599 {
2600 	struct prison *pr;
2601 
2602 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
2603 	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
2604 
2605 	pr = cred->cr_prison;
2606 	if (!(pr->pr_flags & PR_IP4))
2607 		return (0);
2608 	mtx_lock(&pr->pr_mtx);
2609 	if (!(pr->pr_flags & PR_IP4)) {
2610 		mtx_unlock(&pr->pr_mtx);
2611 		return (0);
2612 	}
2613 	if (pr->pr_ip4 == NULL) {
2614 		mtx_unlock(&pr->pr_mtx);
2615 		return (EAFNOSUPPORT);
2616 	}
2617 
2618 	ia->s_addr = pr->pr_ip4[0].s_addr;
2619 	mtx_unlock(&pr->pr_mtx);
2620 	return (0);
2621 }
2622 
2623 /*
2624  * Return true if pr1 and pr2 have the same IPv4 address restrictions.
2625  */
2626 int
2627 prison_equal_ip4(struct prison *pr1, struct prison *pr2)
2628 {
2629 
2630 	if (pr1 == pr2)
2631 		return (1);
2632 
2633 	/*
2634 	 * jail_set maintains an exclusive hold on allprison_lock while it
2635 	 * changes the IP addresses, so only a shared hold is needed.  This is
2636 	 * easier than locking the two prisons which would require finding the
2637 	 * proper locking order and end up needing allprison_lock anyway.
2638 	 */
2639 	sx_slock(&allprison_lock);
2640 	while (pr1 != &prison0 && !(pr1->pr_flags & PR_IP4_USER))
2641 		pr1 = pr1->pr_parent;
2642 	while (pr2 != &prison0 && !(pr2->pr_flags & PR_IP4_USER))
2643 		pr2 = pr2->pr_parent;
2644 	sx_sunlock(&allprison_lock);
2645 	return (pr1 == pr2);
2646 }
2647 
2648 /*
2649  * Make sure our (source) address is set to something meaningful to this
2650  * jail.
2651  *
2652  * Returns 0 if jail doesn't restrict IPv4 or if address belongs to jail,
2653  * EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if the jail
2654  * doesn't allow IPv4.  Address passed in in NBO and returned in NBO.
2655  */
2656 int
2657 prison_local_ip4(struct ucred *cred, struct in_addr *ia)
2658 {
2659 	struct prison *pr;
2660 	struct in_addr ia0;
2661 	int error;
2662 
2663 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
2664 	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
2665 
2666 	pr = cred->cr_prison;
2667 	if (!(pr->pr_flags & PR_IP4))
2668 		return (0);
2669 	mtx_lock(&pr->pr_mtx);
2670 	if (!(pr->pr_flags & PR_IP4)) {
2671 		mtx_unlock(&pr->pr_mtx);
2672 		return (0);
2673 	}
2674 	if (pr->pr_ip4 == NULL) {
2675 		mtx_unlock(&pr->pr_mtx);
2676 		return (EAFNOSUPPORT);
2677 	}
2678 
2679 	ia0.s_addr = ntohl(ia->s_addr);
2680 	if (ia0.s_addr == INADDR_LOOPBACK) {
2681 		ia->s_addr = pr->pr_ip4[0].s_addr;
2682 		mtx_unlock(&pr->pr_mtx);
2683 		return (0);
2684 	}
2685 
2686 	if (ia0.s_addr == INADDR_ANY) {
2687 		/*
2688 		 * In case there is only 1 IPv4 address, bind directly.
2689 		 */
2690 		if (pr->pr_ip4s == 1)
2691 			ia->s_addr = pr->pr_ip4[0].s_addr;
2692 		mtx_unlock(&pr->pr_mtx);
2693 		return (0);
2694 	}
2695 
2696 	error = _prison_check_ip4(pr, ia);
2697 	mtx_unlock(&pr->pr_mtx);
2698 	return (error);
2699 }
2700 
2701 /*
2702  * Rewrite destination address in case we will connect to loopback address.
2703  *
2704  * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
2705  * Address passed in in NBO and returned in NBO.
2706  */
2707 int
2708 prison_remote_ip4(struct ucred *cred, struct in_addr *ia)
2709 {
2710 	struct prison *pr;
2711 
2712 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
2713 	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
2714 
2715 	pr = cred->cr_prison;
2716 	if (!(pr->pr_flags & PR_IP4))
2717 		return (0);
2718 	mtx_lock(&pr->pr_mtx);
2719 	if (!(pr->pr_flags & PR_IP4)) {
2720 		mtx_unlock(&pr->pr_mtx);
2721 		return (0);
2722 	}
2723 	if (pr->pr_ip4 == NULL) {
2724 		mtx_unlock(&pr->pr_mtx);
2725 		return (EAFNOSUPPORT);
2726 	}
2727 
2728 	if (ntohl(ia->s_addr) == INADDR_LOOPBACK) {
2729 		ia->s_addr = pr->pr_ip4[0].s_addr;
2730 		mtx_unlock(&pr->pr_mtx);
2731 		return (0);
2732 	}
2733 
2734 	/*
2735 	 * Return success because nothing had to be changed.
2736 	 */
2737 	mtx_unlock(&pr->pr_mtx);
2738 	return (0);
2739 }
2740 
2741 /*
2742  * Check if given address belongs to the jail referenced by cred/prison.
2743  *
2744  * Returns 0 if jail doesn't restrict IPv4 or if address belongs to jail,
2745  * EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if the jail
2746  * doesn't allow IPv4.  Address passed in in NBO.
2747  */
2748 static int
2749 _prison_check_ip4(struct prison *pr, struct in_addr *ia)
2750 {
2751 	int i, a, z, d;
2752 
2753 	/*
2754 	 * Check the primary IP.
2755 	 */
2756 	if (pr->pr_ip4[0].s_addr == ia->s_addr)
2757 		return (0);
2758 
2759 	/*
2760 	 * All the other IPs are sorted so we can do a binary search.
2761 	 */
2762 	a = 0;
2763 	z = pr->pr_ip4s - 2;
2764 	while (a <= z) {
2765 		i = (a + z) / 2;
2766 		d = qcmp_v4(&pr->pr_ip4[i+1], ia);
2767 		if (d > 0)
2768 			z = i - 1;
2769 		else if (d < 0)
2770 			a = i + 1;
2771 		else
2772 			return (0);
2773 	}
2774 
2775 	return (EADDRNOTAVAIL);
2776 }
2777 
2778 int
2779 prison_check_ip4(struct ucred *cred, struct in_addr *ia)
2780 {
2781 	struct prison *pr;
2782 	int error;
2783 
2784 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
2785 	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
2786 
2787 	pr = cred->cr_prison;
2788 	if (!(pr->pr_flags & PR_IP4))
2789 		return (0);
2790 	mtx_lock(&pr->pr_mtx);
2791 	if (!(pr->pr_flags & PR_IP4)) {
2792 		mtx_unlock(&pr->pr_mtx);
2793 		return (0);
2794 	}
2795 	if (pr->pr_ip4 == NULL) {
2796 		mtx_unlock(&pr->pr_mtx);
2797 		return (EAFNOSUPPORT);
2798 	}
2799 
2800 	error = _prison_check_ip4(pr, ia);
2801 	mtx_unlock(&pr->pr_mtx);
2802 	return (error);
2803 }
2804 #endif
2805 
2806 #ifdef INET6
2807 static int
2808 prison_restrict_ip6(struct prison *pr, struct in6_addr *newip6)
2809 {
2810 	int ii, ij, used;
2811 	struct prison *ppr;
2812 
2813 	ppr = pr->pr_parent;
2814 	if (!(pr->pr_flags & PR_IP6_USER)) {
2815 		/* This has no user settings, so just copy the parent's list. */
2816 		if (pr->pr_ip6s < ppr->pr_ip6s) {
2817 			/*
2818 			 * There's no room for the parent's list.  Use the
2819 			 * new list buffer, which is assumed to be big enough
2820 			 * (if it was passed).  If there's no buffer, try to
2821 			 * allocate one.
2822 			 */
2823 			used = 1;
2824 			if (newip6 == NULL) {
2825 				newip6 = malloc(ppr->pr_ip6s * sizeof(*newip6),
2826 				    M_PRISON, M_NOWAIT);
2827 				if (newip6 != NULL)
2828 					used = 0;
2829 			}
2830 			if (newip6 != NULL) {
2831 				bcopy(ppr->pr_ip6, newip6,
2832 				    ppr->pr_ip6s * sizeof(*newip6));
2833 				free(pr->pr_ip6, M_PRISON);
2834 				pr->pr_ip6 = newip6;
2835 				pr->pr_ip6s = ppr->pr_ip6s;
2836 				pr->pr_flags |= PR_IP6;
2837 			}
2838 			return (used);
2839 		}
2840 		pr->pr_ip6s = ppr->pr_ip6s;
2841 		if (pr->pr_ip6s > 0)
2842 			bcopy(ppr->pr_ip6, pr->pr_ip6,
2843 			    pr->pr_ip6s * sizeof(*newip6));
2844 		else if (pr->pr_ip6 != NULL) {
2845 			free(pr->pr_ip6, M_PRISON);
2846 			pr->pr_ip6 = NULL;
2847 		}
2848 		pr->pr_flags =
2849 			(pr->pr_flags & ~PR_IP6) | (ppr->pr_flags & PR_IP6);
2850 	} else if (pr->pr_ip6s > 0 && (ppr->pr_flags & PR_IP6)) {
2851 		/* Remove addresses that aren't in the parent. */
2852 		for (ij = 0; ij < ppr->pr_ip6s; ij++)
2853 			if (IN6_ARE_ADDR_EQUAL(&pr->pr_ip6[0],
2854 			    &ppr->pr_ip6[ij]))
2855 				break;
2856 		if (ij < ppr->pr_ip6s)
2857 			ii = 1;
2858 		else {
2859 			bcopy(pr->pr_ip6 + 1, pr->pr_ip6,
2860 			    --pr->pr_ip6s * sizeof(*pr->pr_ip6));
2861 			ii = 0;
2862 		}
2863 		for (ij = 1; ii < pr->pr_ip6s; ) {
2864 			if (IN6_ARE_ADDR_EQUAL(&pr->pr_ip6[ii],
2865 			    &ppr->pr_ip6[0])) {
2866 				ii++;
2867 				continue;
2868 			}
2869 			switch (ij >= ppr->pr_ip4s ? -1 :
2870 				qcmp_v6(&pr->pr_ip6[ii], &ppr->pr_ip6[ij])) {
2871 			case -1:
2872 				bcopy(pr->pr_ip6 + ii + 1, pr->pr_ip6 + ii,
2873 				    (--pr->pr_ip6s - ii) * sizeof(*pr->pr_ip6));
2874 				break;
2875 			case 0:
2876 				ii++;
2877 				ij++;
2878 				break;
2879 			case 1:
2880 				ij++;
2881 				break;
2882 			}
2883 		}
2884 		if (pr->pr_ip6s == 0) {
2885 			free(pr->pr_ip6, M_PRISON);
2886 			pr->pr_ip6 = NULL;
2887 		}
2888 	}
2889 	return 0;
2890 }
2891 
2892 /*
2893  * Pass back primary IPv6 address for this jail.
2894  *
2895  * If not restricted return success but do not alter the address.  Caller has
2896  * to make sure to initialize it correctly (e.g. IN6ADDR_ANY_INIT).
2897  *
2898  * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv6.
2899  */
2900 int
2901 prison_get_ip6(struct ucred *cred, struct in6_addr *ia6)
2902 {
2903 	struct prison *pr;
2904 
2905 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
2906 	KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
2907 
2908 	pr = cred->cr_prison;
2909 	if (!(pr->pr_flags & PR_IP6))
2910 		return (0);
2911 	mtx_lock(&pr->pr_mtx);
2912 	if (!(pr->pr_flags & PR_IP6)) {
2913 		mtx_unlock(&pr->pr_mtx);
2914 		return (0);
2915 	}
2916 	if (pr->pr_ip6 == NULL) {
2917 		mtx_unlock(&pr->pr_mtx);
2918 		return (EAFNOSUPPORT);
2919 	}
2920 
2921 	bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
2922 	mtx_unlock(&pr->pr_mtx);
2923 	return (0);
2924 }
2925 
2926 /*
2927  * Return true if pr1 and pr2 have the same IPv6 address restrictions.
2928  */
2929 int
2930 prison_equal_ip6(struct prison *pr1, struct prison *pr2)
2931 {
2932 
2933 	if (pr1 == pr2)
2934 		return (1);
2935 
2936 	sx_slock(&allprison_lock);
2937 	while (pr1 != &prison0 && !(pr1->pr_flags & PR_IP6_USER))
2938 		pr1 = pr1->pr_parent;
2939 	while (pr2 != &prison0 && !(pr2->pr_flags & PR_IP6_USER))
2940 		pr2 = pr2->pr_parent;
2941 	sx_sunlock(&allprison_lock);
2942 	return (pr1 == pr2);
2943 }
2944 
2945 /*
2946  * Make sure our (source) address is set to something meaningful to this jail.
2947  *
2948  * v6only should be set based on (inp->inp_flags & IN6P_IPV6_V6ONLY != 0)
2949  * when needed while binding.
2950  *
2951  * Returns 0 if jail doesn't restrict IPv6 or if address belongs to jail,
2952  * EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if the jail
2953  * doesn't allow IPv6.
2954  */
2955 int
2956 prison_local_ip6(struct ucred *cred, struct in6_addr *ia6, int v6only)
2957 {
2958 	struct prison *pr;
2959 	int error;
2960 
2961 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
2962 	KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
2963 
2964 	pr = cred->cr_prison;
2965 	if (!(pr->pr_flags & PR_IP6))
2966 		return (0);
2967 	mtx_lock(&pr->pr_mtx);
2968 	if (!(pr->pr_flags & PR_IP6)) {
2969 		mtx_unlock(&pr->pr_mtx);
2970 		return (0);
2971 	}
2972 	if (pr->pr_ip6 == NULL) {
2973 		mtx_unlock(&pr->pr_mtx);
2974 		return (EAFNOSUPPORT);
2975 	}
2976 
2977 	if (IN6_IS_ADDR_LOOPBACK(ia6)) {
2978 		bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
2979 		mtx_unlock(&pr->pr_mtx);
2980 		return (0);
2981 	}
2982 
2983 	if (IN6_IS_ADDR_UNSPECIFIED(ia6)) {
2984 		/*
2985 		 * In case there is only 1 IPv6 address, and v6only is true,
2986 		 * then bind directly.
2987 		 */
2988 		if (v6only != 0 && pr->pr_ip6s == 1)
2989 			bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
2990 		mtx_unlock(&pr->pr_mtx);
2991 		return (0);
2992 	}
2993 
2994 	error = _prison_check_ip6(pr, ia6);
2995 	mtx_unlock(&pr->pr_mtx);
2996 	return (error);
2997 }
2998 
2999 /*
3000  * Rewrite destination address in case we will connect to loopback address.
3001  *
3002  * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv6.
3003  */
3004 int
3005 prison_remote_ip6(struct ucred *cred, struct in6_addr *ia6)
3006 {
3007 	struct prison *pr;
3008 
3009 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3010 	KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
3011 
3012 	pr = cred->cr_prison;
3013 	if (!(pr->pr_flags & PR_IP6))
3014 		return (0);
3015 	mtx_lock(&pr->pr_mtx);
3016 	if (!(pr->pr_flags & PR_IP6)) {
3017 		mtx_unlock(&pr->pr_mtx);
3018 		return (0);
3019 	}
3020 	if (pr->pr_ip6 == NULL) {
3021 		mtx_unlock(&pr->pr_mtx);
3022 		return (EAFNOSUPPORT);
3023 	}
3024 
3025 	if (IN6_IS_ADDR_LOOPBACK(ia6)) {
3026 		bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
3027 		mtx_unlock(&pr->pr_mtx);
3028 		return (0);
3029 	}
3030 
3031 	/*
3032 	 * Return success because nothing had to be changed.
3033 	 */
3034 	mtx_unlock(&pr->pr_mtx);
3035 	return (0);
3036 }
3037 
3038 /*
3039  * Check if given address belongs to the jail referenced by cred/prison.
3040  *
3041  * Returns 0 if jail doesn't restrict IPv6 or if address belongs to jail,
3042  * EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if the jail
3043  * doesn't allow IPv6.
3044  */
3045 static int
3046 _prison_check_ip6(struct prison *pr, struct in6_addr *ia6)
3047 {
3048 	int i, a, z, d;
3049 
3050 	/*
3051 	 * Check the primary IP.
3052 	 */
3053 	if (IN6_ARE_ADDR_EQUAL(&pr->pr_ip6[0], ia6))
3054 		return (0);
3055 
3056 	/*
3057 	 * All the other IPs are sorted so we can do a binary search.
3058 	 */
3059 	a = 0;
3060 	z = pr->pr_ip6s - 2;
3061 	while (a <= z) {
3062 		i = (a + z) / 2;
3063 		d = qcmp_v6(&pr->pr_ip6[i+1], ia6);
3064 		if (d > 0)
3065 			z = i - 1;
3066 		else if (d < 0)
3067 			a = i + 1;
3068 		else
3069 			return (0);
3070 	}
3071 
3072 	return (EADDRNOTAVAIL);
3073 }
3074 
3075 int
3076 prison_check_ip6(struct ucred *cred, struct in6_addr *ia6)
3077 {
3078 	struct prison *pr;
3079 	int error;
3080 
3081 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3082 	KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
3083 
3084 	pr = cred->cr_prison;
3085 	if (!(pr->pr_flags & PR_IP6))
3086 		return (0);
3087 	mtx_lock(&pr->pr_mtx);
3088 	if (!(pr->pr_flags & PR_IP6)) {
3089 		mtx_unlock(&pr->pr_mtx);
3090 		return (0);
3091 	}
3092 	if (pr->pr_ip6 == NULL) {
3093 		mtx_unlock(&pr->pr_mtx);
3094 		return (EAFNOSUPPORT);
3095 	}
3096 
3097 	error = _prison_check_ip6(pr, ia6);
3098 	mtx_unlock(&pr->pr_mtx);
3099 	return (error);
3100 }
3101 #endif
3102 
3103 /*
3104  * Check if a jail supports the given address family.
3105  *
3106  * Returns 0 if not jailed or the address family is supported, EAFNOSUPPORT
3107  * if not.
3108  */
3109 int
3110 prison_check_af(struct ucred *cred, int af)
3111 {
3112 	struct prison *pr;
3113 	int error;
3114 
3115 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3116 
3117 	pr = cred->cr_prison;
3118 	error = 0;
3119 	switch (af)
3120 	{
3121 #ifdef INET
3122 	case AF_INET:
3123 		if (pr->pr_flags & PR_IP4)
3124 		{
3125 			mtx_lock(&pr->pr_mtx);
3126 			if ((pr->pr_flags & PR_IP4) && pr->pr_ip4 == NULL)
3127 				error = EAFNOSUPPORT;
3128 			mtx_unlock(&pr->pr_mtx);
3129 		}
3130 		break;
3131 #endif
3132 #ifdef INET6
3133 	case AF_INET6:
3134 		if (pr->pr_flags & PR_IP6)
3135 		{
3136 			mtx_lock(&pr->pr_mtx);
3137 			if ((pr->pr_flags & PR_IP6) && pr->pr_ip6 == NULL)
3138 				error = EAFNOSUPPORT;
3139 			mtx_unlock(&pr->pr_mtx);
3140 		}
3141 		break;
3142 #endif
3143 	case AF_LOCAL:
3144 	case AF_ROUTE:
3145 		break;
3146 	default:
3147 		if (!(pr->pr_allow & PR_ALLOW_SOCKET_AF))
3148 			error = EAFNOSUPPORT;
3149 	}
3150 	return (error);
3151 }
3152 
3153 /*
3154  * Check if given address belongs to the jail referenced by cred (wrapper to
3155  * prison_check_ip[46]).
3156  *
3157  * Returns 0 if jail doesn't restrict the address family or if address belongs
3158  * to jail, EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if
3159  * the jail doesn't allow the address family.  IPv4 Address passed in in NBO.
3160  */
3161 int
3162 prison_if(struct ucred *cred, struct sockaddr *sa)
3163 {
3164 #ifdef INET
3165 	struct sockaddr_in *sai;
3166 #endif
3167 #ifdef INET6
3168 	struct sockaddr_in6 *sai6;
3169 #endif
3170 	int error;
3171 
3172 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3173 	KASSERT(sa != NULL, ("%s: sa is NULL", __func__));
3174 
3175 	error = 0;
3176 	switch (sa->sa_family)
3177 	{
3178 #ifdef INET
3179 	case AF_INET:
3180 		sai = (struct sockaddr_in *)sa;
3181 		error = prison_check_ip4(cred, &sai->sin_addr);
3182 		break;
3183 #endif
3184 #ifdef INET6
3185 	case AF_INET6:
3186 		sai6 = (struct sockaddr_in6 *)sa;
3187 		error = prison_check_ip6(cred, &sai6->sin6_addr);
3188 		break;
3189 #endif
3190 	default:
3191 		if (!(cred->cr_prison->pr_allow & PR_ALLOW_SOCKET_AF))
3192 			error = EAFNOSUPPORT;
3193 	}
3194 	return (error);
3195 }
3196 
3197 /*
3198  * Return 0 if jails permit p1 to frob p2, otherwise ESRCH.
3199  */
3200 int
3201 prison_check(struct ucred *cred1, struct ucred *cred2)
3202 {
3203 
3204 #ifdef VIMAGE
3205 	if (cred2->cr_vimage->v_procg != cred1->cr_vimage->v_procg)
3206 		return (ESRCH);
3207 #endif
3208 	return ((cred1->cr_prison == cred2->cr_prison ||
3209 	    prison_ischild(cred1->cr_prison, cred2->cr_prison)) ? 0 : ESRCH);
3210 }
3211 
3212 /*
3213  * Return 1 if p2 is a child of p1, otherwise 0.
3214  */
3215 int
3216 prison_ischild(struct prison *pr1, struct prison *pr2)
3217 {
3218 
3219 	for (pr2 = pr2->pr_parent; pr2 != NULL; pr2 = pr2->pr_parent)
3220 		if (pr1 == pr2)
3221 			return (1);
3222 	return (0);
3223 }
3224 
3225 /*
3226  * Return 1 if the passed credential is in a jail, otherwise 0.
3227  */
3228 int
3229 jailed(struct ucred *cred)
3230 {
3231 
3232 	return (cred->cr_prison != &prison0);
3233 }
3234 
3235 /*
3236  * Return the correct hostname (domainname, et al) for the passed credential.
3237  */
3238 void
3239 getcredhostname(struct ucred *cred, char *buf, size_t size)
3240 {
3241 	struct prison *pr;
3242 
3243 	/*
3244 	 * A NULL credential can be used to shortcut to the physical
3245 	 * system's hostname.
3246 	 */
3247 	pr = (cred != NULL) ? cred->cr_prison : &prison0;
3248 	mtx_lock(&pr->pr_mtx);
3249 	strlcpy(buf, pr->pr_hostname, size);
3250 	mtx_unlock(&pr->pr_mtx);
3251 }
3252 
3253 void
3254 getcreddomainname(struct ucred *cred, char *buf, size_t size)
3255 {
3256 
3257 	mtx_lock(&cred->cr_prison->pr_mtx);
3258 	strlcpy(buf, cred->cr_prison->pr_domainname, size);
3259 	mtx_unlock(&cred->cr_prison->pr_mtx);
3260 }
3261 
3262 void
3263 getcredhostuuid(struct ucred *cred, char *buf, size_t size)
3264 {
3265 
3266 	mtx_lock(&cred->cr_prison->pr_mtx);
3267 	strlcpy(buf, cred->cr_prison->pr_hostuuid, size);
3268 	mtx_unlock(&cred->cr_prison->pr_mtx);
3269 }
3270 
3271 void
3272 getcredhostid(struct ucred *cred, unsigned long *hostid)
3273 {
3274 
3275 	mtx_lock(&cred->cr_prison->pr_mtx);
3276 	*hostid = cred->cr_prison->pr_hostid;
3277 	mtx_unlock(&cred->cr_prison->pr_mtx);
3278 }
3279 
3280 /*
3281  * Determine whether the subject represented by cred can "see"
3282  * status of a mount point.
3283  * Returns: 0 for permitted, ENOENT otherwise.
3284  * XXX: This function should be called cr_canseemount() and should be
3285  *      placed in kern_prot.c.
3286  */
3287 int
3288 prison_canseemount(struct ucred *cred, struct mount *mp)
3289 {
3290 	struct prison *pr;
3291 	struct statfs *sp;
3292 	size_t len;
3293 
3294 	pr = cred->cr_prison;
3295 	if (pr->pr_enforce_statfs == 0)
3296 		return (0);
3297 	if (pr->pr_root->v_mount == mp)
3298 		return (0);
3299 	if (pr->pr_enforce_statfs == 2)
3300 		return (ENOENT);
3301 	/*
3302 	 * If jail's chroot directory is set to "/" we should be able to see
3303 	 * all mount-points from inside a jail.
3304 	 * This is ugly check, but this is the only situation when jail's
3305 	 * directory ends with '/'.
3306 	 */
3307 	if (strcmp(pr->pr_path, "/") == 0)
3308 		return (0);
3309 	len = strlen(pr->pr_path);
3310 	sp = &mp->mnt_stat;
3311 	if (strncmp(pr->pr_path, sp->f_mntonname, len) != 0)
3312 		return (ENOENT);
3313 	/*
3314 	 * Be sure that we don't have situation where jail's root directory
3315 	 * is "/some/path" and mount point is "/some/pathpath".
3316 	 */
3317 	if (sp->f_mntonname[len] != '\0' && sp->f_mntonname[len] != '/')
3318 		return (ENOENT);
3319 	return (0);
3320 }
3321 
3322 void
3323 prison_enforce_statfs(struct ucred *cred, struct mount *mp, struct statfs *sp)
3324 {
3325 	char jpath[MAXPATHLEN];
3326 	struct prison *pr;
3327 	size_t len;
3328 
3329 	pr = cred->cr_prison;
3330 	if (pr->pr_enforce_statfs == 0)
3331 		return;
3332 	if (prison_canseemount(cred, mp) != 0) {
3333 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3334 		strlcpy(sp->f_mntonname, "[restricted]",
3335 		    sizeof(sp->f_mntonname));
3336 		return;
3337 	}
3338 	if (pr->pr_root->v_mount == mp) {
3339 		/*
3340 		 * Clear current buffer data, so we are sure nothing from
3341 		 * the valid path left there.
3342 		 */
3343 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3344 		*sp->f_mntonname = '/';
3345 		return;
3346 	}
3347 	/*
3348 	 * If jail's chroot directory is set to "/" we should be able to see
3349 	 * all mount-points from inside a jail.
3350 	 */
3351 	if (strcmp(pr->pr_path, "/") == 0)
3352 		return;
3353 	len = strlen(pr->pr_path);
3354 	strlcpy(jpath, sp->f_mntonname + len, sizeof(jpath));
3355 	/*
3356 	 * Clear current buffer data, so we are sure nothing from
3357 	 * the valid path left there.
3358 	 */
3359 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3360 	if (*jpath == '\0') {
3361 		/* Should never happen. */
3362 		*sp->f_mntonname = '/';
3363 	} else {
3364 		strlcpy(sp->f_mntonname, jpath, sizeof(sp->f_mntonname));
3365 	}
3366 }
3367 
3368 /*
3369  * Check with permission for a specific privilege is granted within jail.  We
3370  * have a specific list of accepted privileges; the rest are denied.
3371  */
3372 int
3373 prison_priv_check(struct ucred *cred, int priv)
3374 {
3375 
3376 	if (!jailed(cred))
3377 		return (0);
3378 
3379 	switch (priv) {
3380 
3381 		/*
3382 		 * Allow ktrace privileges for root in jail.
3383 		 */
3384 	case PRIV_KTRACE:
3385 
3386 #if 0
3387 		/*
3388 		 * Allow jailed processes to configure audit identity and
3389 		 * submit audit records (login, etc).  In the future we may
3390 		 * want to further refine the relationship between audit and
3391 		 * jail.
3392 		 */
3393 	case PRIV_AUDIT_GETAUDIT:
3394 	case PRIV_AUDIT_SETAUDIT:
3395 	case PRIV_AUDIT_SUBMIT:
3396 #endif
3397 
3398 		/*
3399 		 * Allow jailed processes to manipulate process UNIX
3400 		 * credentials in any way they see fit.
3401 		 */
3402 	case PRIV_CRED_SETUID:
3403 	case PRIV_CRED_SETEUID:
3404 	case PRIV_CRED_SETGID:
3405 	case PRIV_CRED_SETEGID:
3406 	case PRIV_CRED_SETGROUPS:
3407 	case PRIV_CRED_SETREUID:
3408 	case PRIV_CRED_SETREGID:
3409 	case PRIV_CRED_SETRESUID:
3410 	case PRIV_CRED_SETRESGID:
3411 
3412 		/*
3413 		 * Jail implements visibility constraints already, so allow
3414 		 * jailed root to override uid/gid-based constraints.
3415 		 */
3416 	case PRIV_SEEOTHERGIDS:
3417 	case PRIV_SEEOTHERUIDS:
3418 
3419 		/*
3420 		 * Jail implements inter-process debugging limits already, so
3421 		 * allow jailed root various debugging privileges.
3422 		 */
3423 	case PRIV_DEBUG_DIFFCRED:
3424 	case PRIV_DEBUG_SUGID:
3425 	case PRIV_DEBUG_UNPRIV:
3426 
3427 		/*
3428 		 * Allow jail to set various resource limits and login
3429 		 * properties, and for now, exceed process resource limits.
3430 		 */
3431 	case PRIV_PROC_LIMIT:
3432 	case PRIV_PROC_SETLOGIN:
3433 	case PRIV_PROC_SETRLIMIT:
3434 
3435 		/*
3436 		 * System V and POSIX IPC privileges are granted in jail.
3437 		 */
3438 	case PRIV_IPC_READ:
3439 	case PRIV_IPC_WRITE:
3440 	case PRIV_IPC_ADMIN:
3441 	case PRIV_IPC_MSGSIZE:
3442 	case PRIV_MQ_ADMIN:
3443 
3444 		/*
3445 		 * Jail operations within a jail work on child jails.
3446 		 */
3447 	case PRIV_JAIL_ATTACH:
3448 	case PRIV_JAIL_SET:
3449 	case PRIV_JAIL_REMOVE:
3450 
3451 		/*
3452 		 * Jail implements its own inter-process limits, so allow
3453 		 * root processes in jail to change scheduling on other
3454 		 * processes in the same jail.  Likewise for signalling.
3455 		 */
3456 	case PRIV_SCHED_DIFFCRED:
3457 	case PRIV_SCHED_CPUSET:
3458 	case PRIV_SIGNAL_DIFFCRED:
3459 	case PRIV_SIGNAL_SUGID:
3460 
3461 		/*
3462 		 * Allow jailed processes to write to sysctls marked as jail
3463 		 * writable.
3464 		 */
3465 	case PRIV_SYSCTL_WRITEJAIL:
3466 
3467 		/*
3468 		 * Allow root in jail to manage a variety of quota
3469 		 * properties.  These should likely be conditional on a
3470 		 * configuration option.
3471 		 */
3472 	case PRIV_VFS_GETQUOTA:
3473 	case PRIV_VFS_SETQUOTA:
3474 
3475 		/*
3476 		 * Since Jail relies on chroot() to implement file system
3477 		 * protections, grant many VFS privileges to root in jail.
3478 		 * Be careful to exclude mount-related and NFS-related
3479 		 * privileges.
3480 		 */
3481 	case PRIV_VFS_READ:
3482 	case PRIV_VFS_WRITE:
3483 	case PRIV_VFS_ADMIN:
3484 	case PRIV_VFS_EXEC:
3485 	case PRIV_VFS_LOOKUP:
3486 	case PRIV_VFS_BLOCKRESERVE:	/* XXXRW: Slightly surprising. */
3487 	case PRIV_VFS_CHFLAGS_DEV:
3488 	case PRIV_VFS_CHOWN:
3489 	case PRIV_VFS_CHROOT:
3490 	case PRIV_VFS_RETAINSUGID:
3491 	case PRIV_VFS_FCHROOT:
3492 	case PRIV_VFS_LINK:
3493 	case PRIV_VFS_SETGID:
3494 	case PRIV_VFS_STAT:
3495 	case PRIV_VFS_STICKYFILE:
3496 		return (0);
3497 
3498 		/*
3499 		 * Depending on the global setting, allow privilege of
3500 		 * setting system flags.
3501 		 */
3502 	case PRIV_VFS_SYSFLAGS:
3503 		if (cred->cr_prison->pr_allow & PR_ALLOW_CHFLAGS)
3504 			return (0);
3505 		else
3506 			return (EPERM);
3507 
3508 		/*
3509 		 * Depending on the global setting, allow privilege of
3510 		 * mounting/unmounting file systems.
3511 		 */
3512 	case PRIV_VFS_MOUNT:
3513 	case PRIV_VFS_UNMOUNT:
3514 	case PRIV_VFS_MOUNT_NONUSER:
3515 	case PRIV_VFS_MOUNT_OWNER:
3516 		if (cred->cr_prison->pr_allow & PR_ALLOW_MOUNT)
3517 			return (0);
3518 		else
3519 			return (EPERM);
3520 
3521 		/*
3522 		 * Allow jailed root to bind reserved ports and reuse in-use
3523 		 * ports.
3524 		 */
3525 	case PRIV_NETINET_RESERVEDPORT:
3526 	case PRIV_NETINET_REUSEPORT:
3527 		return (0);
3528 
3529 		/*
3530 		 * Allow jailed root to set certian IPv4/6 (option) headers.
3531 		 */
3532 	case PRIV_NETINET_SETHDROPTS:
3533 		return (0);
3534 
3535 		/*
3536 		 * Conditionally allow creating raw sockets in jail.
3537 		 */
3538 	case PRIV_NETINET_RAW:
3539 		if (cred->cr_prison->pr_allow & PR_ALLOW_RAW_SOCKETS)
3540 			return (0);
3541 		else
3542 			return (EPERM);
3543 
3544 		/*
3545 		 * Since jail implements its own visibility limits on netstat
3546 		 * sysctls, allow getcred.  This allows identd to work in
3547 		 * jail.
3548 		 */
3549 	case PRIV_NETINET_GETCRED:
3550 		return (0);
3551 
3552 	default:
3553 		/*
3554 		 * In all remaining cases, deny the privilege request.  This
3555 		 * includes almost all network privileges, many system
3556 		 * configuration privileges.
3557 		 */
3558 		return (EPERM);
3559 	}
3560 }
3561 
3562 /*
3563  * Return the part of pr2's name that is relative to pr1, or the whole name
3564  * if it does not directly follow.
3565  */
3566 
3567 char *
3568 prison_name(struct prison *pr1, struct prison *pr2)
3569 {
3570 	char *name;
3571 
3572 	/* Jails see themselves as "0" (if they see themselves at all). */
3573 	if (pr1 == pr2)
3574 		return "0";
3575 	name = pr2->pr_name;
3576 	if (prison_ischild(pr1, pr2)) {
3577 		/*
3578 		 * pr1 isn't locked (and allprison_lock may not be either)
3579 		 * so its length can't be counted on.  But the number of dots
3580 		 * can be counted on - and counted.
3581 		 */
3582 		for (; pr1 != &prison0; pr1 = pr1->pr_parent)
3583 			name = strchr(name, '.') + 1;
3584 	}
3585 	return (name);
3586 }
3587 
3588 /*
3589  * Return the part of pr2's path that is relative to pr1, or the whole path
3590  * if it does not directly follow.
3591  */
3592 static char *
3593 prison_path(struct prison *pr1, struct prison *pr2)
3594 {
3595 	char *path1, *path2;
3596 	int len1;
3597 
3598 	path1 = pr1->pr_path;
3599 	path2 = pr2->pr_path;
3600 	if (!strcmp(path1, "/"))
3601 		return (path2);
3602 	len1 = strlen(path1);
3603 	if (strncmp(path1, path2, len1))
3604 		return (path2);
3605 	if (path2[len1] == '\0')
3606 		return "/";
3607 	if (path2[len1] == '/')
3608 		return (path2 + len1);
3609 	return (path2);
3610 }
3611 
3612 
3613 /*
3614  * Jail-related sysctls.
3615  */
3616 SYSCTL_NODE(_security, OID_AUTO, jail, CTLFLAG_RW, 0,
3617     "Jails");
3618 
3619 static int
3620 sysctl_jail_list(SYSCTL_HANDLER_ARGS)
3621 {
3622 	struct xprison *xp;
3623 	struct prison *pr, *cpr;
3624 #ifdef INET
3625 	struct in_addr *ip4 = NULL;
3626 	int ip4s = 0;
3627 #endif
3628 #ifdef INET6
3629 	struct in_addr *ip6 = NULL;
3630 	int ip6s = 0;
3631 #endif
3632 	int descend, error;
3633 
3634 	xp = malloc(sizeof(*xp), M_TEMP, M_WAITOK);
3635 	pr = req->td->td_ucred->cr_prison;
3636 	error = 0;
3637 	sx_slock(&allprison_lock);
3638 	FOREACH_PRISON_DESCENDANT(pr, cpr, descend) {
3639 #if defined(INET) || defined(INET6)
3640  again:
3641 #endif
3642 		mtx_lock(&cpr->pr_mtx);
3643 #ifdef INET
3644 		if (cpr->pr_ip4s > 0) {
3645 			if (ip4s < cpr->pr_ip4s) {
3646 				ip4s = cpr->pr_ip4s;
3647 				mtx_unlock(&cpr->pr_mtx);
3648 				ip4 = realloc(ip4, ip4s *
3649 				    sizeof(struct in_addr), M_TEMP, M_WAITOK);
3650 				goto again;
3651 			}
3652 			bcopy(cpr->pr_ip4, ip4,
3653 			    cpr->pr_ip4s * sizeof(struct in_addr));
3654 		}
3655 #endif
3656 #ifdef INET6
3657 		if (cpr->pr_ip6s > 0) {
3658 			if (ip6s < cpr->pr_ip6s) {
3659 				ip6s = cpr->pr_ip6s;
3660 				mtx_unlock(&cpr->pr_mtx);
3661 				ip6 = realloc(ip6, ip6s *
3662 				    sizeof(struct in6_addr), M_TEMP, M_WAITOK);
3663 				goto again;
3664 			}
3665 			bcopy(cpr->pr_ip6, ip6,
3666 			    cpr->pr_ip6s * sizeof(struct in6_addr));
3667 		}
3668 #endif
3669 		if (cpr->pr_ref == 0) {
3670 			mtx_unlock(&cpr->pr_mtx);
3671 			continue;
3672 		}
3673 		bzero(xp, sizeof(*xp));
3674 		xp->pr_version = XPRISON_VERSION;
3675 		xp->pr_id = cpr->pr_id;
3676 		xp->pr_state = cpr->pr_uref > 0
3677 		    ? PRISON_STATE_ALIVE : PRISON_STATE_DYING;
3678 		strlcpy(xp->pr_path, prison_path(pr, cpr), sizeof(xp->pr_path));
3679 		strlcpy(xp->pr_host, cpr->pr_hostname, sizeof(xp->pr_host));
3680 		strlcpy(xp->pr_name, prison_name(pr, cpr), sizeof(xp->pr_name));
3681 #ifdef INET
3682 		xp->pr_ip4s = cpr->pr_ip4s;
3683 #endif
3684 #ifdef INET6
3685 		xp->pr_ip6s = cpr->pr_ip6s;
3686 #endif
3687 		mtx_unlock(&cpr->pr_mtx);
3688 		error = SYSCTL_OUT(req, xp, sizeof(*xp));
3689 		if (error)
3690 			break;
3691 #ifdef INET
3692 		if (xp->pr_ip4s > 0) {
3693 			error = SYSCTL_OUT(req, ip4,
3694 			    xp->pr_ip4s * sizeof(struct in_addr));
3695 			if (error)
3696 				break;
3697 		}
3698 #endif
3699 #ifdef INET6
3700 		if (xp->pr_ip6s > 0) {
3701 			error = SYSCTL_OUT(req, ip6,
3702 			    xp->pr_ip6s * sizeof(struct in6_addr));
3703 			if (error)
3704 				break;
3705 		}
3706 #endif
3707 	}
3708 	sx_sunlock(&allprison_lock);
3709 	free(xp, M_TEMP);
3710 #ifdef INET
3711 	free(ip4, M_TEMP);
3712 #endif
3713 #ifdef INET6
3714 	free(ip6, M_TEMP);
3715 #endif
3716 	return (error);
3717 }
3718 
3719 SYSCTL_OID(_security_jail, OID_AUTO, list,
3720     CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
3721     sysctl_jail_list, "S", "List of active jails");
3722 
3723 static int
3724 sysctl_jail_jailed(SYSCTL_HANDLER_ARGS)
3725 {
3726 	int error, injail;
3727 
3728 	injail = jailed(req->td->td_ucred);
3729 	error = SYSCTL_OUT(req, &injail, sizeof(injail));
3730 
3731 	return (error);
3732 }
3733 
3734 SYSCTL_PROC(_security_jail, OID_AUTO, jailed,
3735     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
3736     sysctl_jail_jailed, "I", "Process in jail?");
3737 
3738 #if defined(INET) || defined(INET6)
3739 SYSCTL_UINT(_security_jail, OID_AUTO, jail_max_af_ips, CTLFLAG_RW,
3740     &jail_max_af_ips, 0,
3741     "Number of IP addresses a jail may have at most per address family");
3742 #endif
3743 
3744 /*
3745  * Default parameters for jail(2) compatability.  For historical reasons,
3746  * the sysctl names have varying similarity to the parameter names.  Prisons
3747  * just see their own parameters, and can't change them.
3748  */
3749 static int
3750 sysctl_jail_default_allow(SYSCTL_HANDLER_ARGS)
3751 {
3752 	struct prison *pr;
3753 	int allow, error, i;
3754 
3755 	pr = req->td->td_ucred->cr_prison;
3756 	allow = (pr == &prison0) ? jail_default_allow : pr->pr_allow;
3757 
3758 	/* Get the current flag value, and convert it to a boolean. */
3759 	i = (allow & arg2) ? 1 : 0;
3760 	if (arg1 != NULL)
3761 		i = !i;
3762 	error = sysctl_handle_int(oidp, &i, 0, req);
3763 	if (error || !req->newptr)
3764 		return (error);
3765 	i = i ? arg2 : 0;
3766 	if (arg1 != NULL)
3767 		i ^= arg2;
3768 	/*
3769 	 * The sysctls don't have CTLFLAGS_PRISON, so assume prison0
3770 	 * for writing.
3771 	 */
3772 	mtx_lock(&prison0.pr_mtx);
3773 	jail_default_allow = (jail_default_allow & ~arg2) | i;
3774 	mtx_unlock(&prison0.pr_mtx);
3775 	return (0);
3776 }
3777 
3778 SYSCTL_PROC(_security_jail, OID_AUTO, set_hostname_allowed,
3779     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3780     NULL, PR_ALLOW_SET_HOSTNAME, sysctl_jail_default_allow, "I",
3781     "Processes in jail can set their hostnames");
3782 SYSCTL_PROC(_security_jail, OID_AUTO, socket_unixiproute_only,
3783     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3784     (void *)1, PR_ALLOW_SOCKET_AF, sysctl_jail_default_allow, "I",
3785     "Processes in jail are limited to creating UNIX/IP/route sockets only");
3786 SYSCTL_PROC(_security_jail, OID_AUTO, sysvipc_allowed,
3787     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3788     NULL, PR_ALLOW_SYSVIPC, sysctl_jail_default_allow, "I",
3789     "Processes in jail can use System V IPC primitives");
3790 SYSCTL_PROC(_security_jail, OID_AUTO, allow_raw_sockets,
3791     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3792     NULL, PR_ALLOW_RAW_SOCKETS, sysctl_jail_default_allow, "I",
3793     "Prison root can create raw sockets");
3794 SYSCTL_PROC(_security_jail, OID_AUTO, chflags_allowed,
3795     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3796     NULL, PR_ALLOW_CHFLAGS, sysctl_jail_default_allow, "I",
3797     "Processes in jail can alter system file flags");
3798 SYSCTL_PROC(_security_jail, OID_AUTO, mount_allowed,
3799     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3800     NULL, PR_ALLOW_MOUNT, sysctl_jail_default_allow, "I",
3801     "Processes in jail can mount/unmount jail-friendly file systems");
3802 
3803 static int
3804 sysctl_jail_default_level(SYSCTL_HANDLER_ARGS)
3805 {
3806 	struct prison *pr;
3807 	int level, error;
3808 
3809 	pr = req->td->td_ucred->cr_prison;
3810 	level = (pr == &prison0) ? *(int *)arg1 : *(int *)((char *)pr + arg2);
3811 	error = sysctl_handle_int(oidp, &level, 0, req);
3812 	if (error || !req->newptr)
3813 		return (error);
3814 	*(int *)arg1 = level;
3815 	return (0);
3816 }
3817 
3818 SYSCTL_PROC(_security_jail, OID_AUTO, enforce_statfs,
3819     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
3820     &jail_default_enforce_statfs, offsetof(struct prison, pr_enforce_statfs),
3821     sysctl_jail_default_level, "I",
3822     "Processes in jail cannot see all mounted file systems");
3823 
3824 /*
3825  * Nodes to describe jail parameters.  Maximum length of string parameters
3826  * is returned in the string itself, and the other parameters exist merely
3827  * to make themselves and their types known.
3828  */
3829 SYSCTL_NODE(_security_jail, OID_AUTO, param, CTLFLAG_RW, 0,
3830     "Jail parameters");
3831 
3832 int
3833 sysctl_jail_param(SYSCTL_HANDLER_ARGS)
3834 {
3835 	int i;
3836 	long l;
3837 	size_t s;
3838 	char numbuf[12];
3839 
3840 	switch (oidp->oid_kind & CTLTYPE)
3841 	{
3842 	case CTLTYPE_LONG:
3843 	case CTLTYPE_ULONG:
3844 		l = 0;
3845 #ifdef SCTL_MASK32
3846 		if (!(req->flags & SCTL_MASK32))
3847 #endif
3848 			return (SYSCTL_OUT(req, &l, sizeof(l)));
3849 	case CTLTYPE_INT:
3850 	case CTLTYPE_UINT:
3851 		i = 0;
3852 		return (SYSCTL_OUT(req, &i, sizeof(i)));
3853 	case CTLTYPE_STRING:
3854 		snprintf(numbuf, sizeof(numbuf), "%d", arg2);
3855 		return
3856 		    (sysctl_handle_string(oidp, numbuf, sizeof(numbuf), req));
3857 	case CTLTYPE_STRUCT:
3858 		s = (size_t)arg2;
3859 		return (SYSCTL_OUT(req, &s, sizeof(s)));
3860 	}
3861 	return (0);
3862 }
3863 
3864 SYSCTL_JAIL_PARAM(, jid, CTLTYPE_INT | CTLFLAG_RDTUN, "I", "Jail ID");
3865 SYSCTL_JAIL_PARAM(, parent, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail parent ID");
3866 SYSCTL_JAIL_PARAM_STRING(, name, CTLFLAG_RW, MAXHOSTNAMELEN, "Jail name");
3867 SYSCTL_JAIL_PARAM_STRING(, path, CTLFLAG_RDTUN, MAXPATHLEN, "Jail root path");
3868 SYSCTL_JAIL_PARAM(, securelevel, CTLTYPE_INT | CTLFLAG_RW,
3869     "I", "Jail secure level");
3870 SYSCTL_JAIL_PARAM(, enforce_statfs, CTLTYPE_INT | CTLFLAG_RW,
3871     "I", "Jail cannot see all mounted file systems");
3872 SYSCTL_JAIL_PARAM(, persist, CTLTYPE_INT | CTLFLAG_RW,
3873     "B", "Jail persistence");
3874 #ifdef VIMAGE
3875 SYSCTL_JAIL_PARAM(, vnet, CTLTYPE_INT | CTLFLAG_RDTUN,
3876     "B", "Virtual network stack");
3877 #endif
3878 SYSCTL_JAIL_PARAM(, dying, CTLTYPE_INT | CTLFLAG_RD,
3879     "B", "Jail is in the process of shutting down");
3880 
3881 SYSCTL_JAIL_PARAM_NODE(host, "Jail host info");
3882 SYSCTL_JAIL_PARAM(, nohost, CTLTYPE_INT | CTLFLAG_RW,
3883     "BN", "Jail w/ no host info");
3884 SYSCTL_JAIL_PARAM_STRING(_host, hostname, CTLFLAG_RW, MAXHOSTNAMELEN,
3885     "Jail hostname");
3886 SYSCTL_JAIL_PARAM_STRING(_host, domainname, CTLFLAG_RW, MAXHOSTNAMELEN,
3887     "Jail NIS domainname");
3888 SYSCTL_JAIL_PARAM_STRING(_host, hostuuid, CTLFLAG_RW, HOSTUUIDLEN,
3889     "Jail host UUID");
3890 SYSCTL_JAIL_PARAM(_host, hostid, CTLTYPE_ULONG | CTLFLAG_RW,
3891     "LU", "Jail host ID");
3892 
3893 SYSCTL_JAIL_PARAM_NODE(cpuset, "Jail cpuset");
3894 SYSCTL_JAIL_PARAM(_cpuset, id, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail cpuset ID");
3895 
3896 #ifdef INET
3897 SYSCTL_JAIL_PARAM_NODE(ip4, "Jail IPv4 address virtualization");
3898 SYSCTL_JAIL_PARAM(, noip4, CTLTYPE_INT | CTLFLAG_RW,
3899     "BN", "Jail w/ no IP address virtualization");
3900 SYSCTL_JAIL_PARAM_STRUCT(_ip4, addr, CTLFLAG_RW, sizeof(struct in_addr),
3901     "S,in_addr,a", "Jail IPv4 addresses");
3902 #endif
3903 #ifdef INET6
3904 SYSCTL_JAIL_PARAM_NODE(ip6, "Jail IPv6 address virtualization");
3905 SYSCTL_JAIL_PARAM(, noip6, CTLTYPE_INT | CTLFLAG_RW,
3906     "BN", "Jail w/ no IP address virtualization");
3907 SYSCTL_JAIL_PARAM_STRUCT(_ip6, addr, CTLFLAG_RW, sizeof(struct in6_addr),
3908     "S,in6_addr,a", "Jail IPv6 addresses");
3909 #endif
3910 
3911 SYSCTL_JAIL_PARAM_NODE(allow, "Jail permission flags");
3912 SYSCTL_JAIL_PARAM(_allow, set_hostname, CTLTYPE_INT | CTLFLAG_RW,
3913     "B", "Jail may set hostname");
3914 SYSCTL_JAIL_PARAM(_allow, sysvipc, CTLTYPE_INT | CTLFLAG_RW,
3915     "B", "Jail may use SYSV IPC");
3916 SYSCTL_JAIL_PARAM(_allow, raw_sockets, CTLTYPE_INT | CTLFLAG_RW,
3917     "B", "Jail may create raw sockets");
3918 SYSCTL_JAIL_PARAM(_allow, chflags, CTLTYPE_INT | CTLFLAG_RW,
3919     "B", "Jail may alter system file flags");
3920 SYSCTL_JAIL_PARAM(_allow, mount, CTLTYPE_INT | CTLFLAG_RW,
3921     "B", "Jail may mount/unmount jail-friendly file systems");
3922 SYSCTL_JAIL_PARAM(_allow, quotas, CTLTYPE_INT | CTLFLAG_RW,
3923     "B", "Jail may set file quotas");
3924 SYSCTL_JAIL_PARAM(_allow, jails, CTLTYPE_INT | CTLFLAG_RW,
3925     "B", "Jail may create child jails");
3926 SYSCTL_JAIL_PARAM(_allow, socket_af, CTLTYPE_INT | CTLFLAG_RW,
3927     "B", "Jail may create sockets other than just UNIX/IPv4/IPv6/route");
3928 
3929 
3930 #ifdef DDB
3931 
3932 static void
3933 db_show_prison(struct prison *pr)
3934 {
3935 	int fi;
3936 #if defined(INET) || defined(INET6)
3937 	int ii;
3938 #endif
3939 #ifdef INET6
3940 	char ip6buf[INET6_ADDRSTRLEN];
3941 #endif
3942 
3943 	db_printf("prison %p:\n", pr);
3944 	db_printf(" jid             = %d\n", pr->pr_id);
3945 	db_printf(" name            = %s\n", pr->pr_name);
3946 	db_printf(" parent          = %p\n", pr->pr_parent);
3947 	db_printf(" ref             = %d\n", pr->pr_ref);
3948 	db_printf(" uref            = %d\n", pr->pr_uref);
3949 	db_printf(" path            = %s\n", pr->pr_path);
3950 	db_printf(" cpuset          = %d\n", pr->pr_cpuset
3951 	    ? pr->pr_cpuset->cs_id : -1);
3952 #ifdef VIMAGE
3953 	db_printf(" vnet            = %p\n", pr->pr_vnet);
3954 #endif
3955 	db_printf(" root            = %p\n", pr->pr_root);
3956 	db_printf(" securelevel     = %d\n", pr->pr_securelevel);
3957 	db_printf(" child           = %p\n", LIST_FIRST(&pr->pr_children));
3958 	db_printf(" sibling         = %p\n", LIST_NEXT(pr, pr_sibling));
3959 	db_printf(" flags           = %x", pr->pr_flags);
3960 	for (fi = 0; fi < sizeof(pr_flag_names) / sizeof(pr_flag_names[0]);
3961 	    fi++)
3962 		if (pr_flag_names[fi] != NULL && (pr->pr_flags & (1 << fi)))
3963 			db_printf(" %s", pr_flag_names[fi]);
3964 	db_printf(" allow           = %x", pr->pr_allow);
3965 	for (fi = 0; fi < sizeof(pr_allow_names) / sizeof(pr_allow_names[0]);
3966 	    fi++)
3967 		if (pr_allow_names[fi] != NULL && (pr->pr_allow & (1 << fi)))
3968 			db_printf(" %s", pr_allow_names[fi]);
3969 	db_printf("\n");
3970 	db_printf(" enforce_statfs  = %d\n", pr->pr_enforce_statfs);
3971 	db_printf(" host.hostname   = %s\n", pr->pr_hostname);
3972 	db_printf(" host.domainname = %s\n", pr->pr_domainname);
3973 	db_printf(" host.hostuuid   = %s\n", pr->pr_hostuuid);
3974 	db_printf(" host.hostid     = %lu\n", pr->pr_hostid);
3975 #ifdef INET
3976 	db_printf(" ip4s            = %d\n", pr->pr_ip4s);
3977 	for (ii = 0; ii < pr->pr_ip4s; ii++)
3978 		db_printf(" %s %s\n",
3979 		    ii == 0 ? "ip4             =" : "                 ",
3980 		    inet_ntoa(pr->pr_ip4[ii]));
3981 #endif
3982 #ifdef INET6
3983 	db_printf(" ip6s            = %d\n", pr->pr_ip6s);
3984 	for (ii = 0; ii < pr->pr_ip6s; ii++)
3985 		db_printf(" %s %s\n",
3986 		    ii == 0 ? "ip6             =" : "                 ",
3987 		    ip6_sprintf(ip6buf, &pr->pr_ip6[ii]));
3988 #endif
3989 }
3990 
3991 DB_SHOW_COMMAND(prison, db_show_prison_command)
3992 {
3993 	struct prison *pr;
3994 
3995 	if (!have_addr) {
3996 		/*
3997 		 * Show all prisons in the list, and prison0 which is not
3998 		 * listed.
3999 		 */
4000 		db_show_prison(&prison0);
4001 		if (!db_pager_quit) {
4002 			TAILQ_FOREACH(pr, &allprison, pr_list) {
4003 				db_show_prison(pr);
4004 				if (db_pager_quit)
4005 					break;
4006 			}
4007 		}
4008 		return;
4009 	}
4010 
4011 	if (addr == 0)
4012 		pr = &prison0;
4013 	else {
4014 		/* Look for a prison with the ID and with references. */
4015 		TAILQ_FOREACH(pr, &allprison, pr_list)
4016 			if (pr->pr_id == addr && pr->pr_ref > 0)
4017 				break;
4018 		if (pr == NULL)
4019 			/* Look again, without requiring a reference. */
4020 			TAILQ_FOREACH(pr, &allprison, pr_list)
4021 				if (pr->pr_id == addr)
4022 					break;
4023 		if (pr == NULL)
4024 			/* Assume address points to a valid prison. */
4025 			pr = (struct prison *)addr;
4026 	}
4027 	db_show_prison(pr);
4028 }
4029 
4030 #endif /* DDB */
4031