xref: /freebsd/sys/kern/kern_jail.c (revision 30e6e008bc06385a66756bebb41676f4f9017eca)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 1999 Poul-Henning Kamp.
5  * Copyright (c) 2008 Bjoern A. Zeeb.
6  * Copyright (c) 2009 James Gritton.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #include "opt_ddb.h"
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 #include "opt_nfs.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/epoch.h>
48 #include <sys/taskqueue.h>
49 #include <sys/fcntl.h>
50 #include <sys/jail.h>
51 #include <sys/linker.h>
52 #include <sys/lock.h>
53 #include <sys/mman.h>
54 #include <sys/mutex.h>
55 #include <sys/racct.h>
56 #include <sys/rctl.h>
57 #include <sys/refcount.h>
58 #include <sys/sx.h>
59 #include <sys/sysent.h>
60 #include <sys/namei.h>
61 #include <sys/mount.h>
62 #include <sys/queue.h>
63 #include <sys/socket.h>
64 #include <sys/syscallsubr.h>
65 #include <sys/sysctl.h>
66 #include <sys/uuid.h>
67 #include <sys/vnode.h>
68 
69 #include <net/if.h>
70 #include <net/vnet.h>
71 
72 #include <netinet/in.h>
73 
74 #ifdef DDB
75 #include <ddb/ddb.h>
76 #endif /* DDB */
77 
78 #include <security/mac/mac_framework.h>
79 
80 #define	PRISON0_HOSTUUID_MODULE	"hostuuid"
81 
82 MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
83 static MALLOC_DEFINE(M_PRISON_RACCT, "prison_racct", "Prison racct structures");
84 
85 /* Keep struct prison prison0 and some code in kern_jail_set() readable. */
86 #ifdef INET
87 #ifdef INET6
88 #define	_PR_IP_SADDRSEL	PR_IP4_SADDRSEL|PR_IP6_SADDRSEL
89 #else
90 #define	_PR_IP_SADDRSEL	PR_IP4_SADDRSEL
91 #endif
92 #else /* !INET */
93 #ifdef INET6
94 #define	_PR_IP_SADDRSEL	PR_IP6_SADDRSEL
95 #else
96 #define	_PR_IP_SADDRSEL	0
97 #endif
98 #endif
99 
100 /* prison0 describes what is "real" about the system. */
101 struct prison prison0 = {
102 	.pr_id		= 0,
103 	.pr_name	= "0",
104 	.pr_ref		= 1,
105 	.pr_uref	= 1,
106 	.pr_path	= "/",
107 	.pr_securelevel	= -1,
108 	.pr_devfs_rsnum = 0,
109 	.pr_state	= PRISON_STATE_ALIVE,
110 	.pr_childmax	= JAIL_MAX,
111 	.pr_hostuuid	= DEFAULT_HOSTUUID,
112 	.pr_children	= LIST_HEAD_INITIALIZER(prison0.pr_children),
113 #ifdef VIMAGE
114 	.pr_flags	= PR_HOST|PR_VNET|_PR_IP_SADDRSEL,
115 #else
116 	.pr_flags	= PR_HOST|_PR_IP_SADDRSEL,
117 #endif
118 	.pr_allow	= PR_ALLOW_ALL_STATIC,
119 };
120 MTX_SYSINIT(prison0, &prison0.pr_mtx, "jail mutex", MTX_DEF);
121 
122 struct bool_flags {
123 	const char	*name;
124 	const char	*noname;
125 	volatile u_int	 flag;
126 };
127 struct jailsys_flags {
128 	const char	*name;
129 	unsigned	 disable;
130 	unsigned	 new;
131 };
132 
133 /*
134  * Handle jail teardown in a dedicated thread to avoid deadlocks from
135  * vnet_destroy().
136  */
137 TASKQUEUE_DEFINE_THREAD(jail_remove);
138 
139 /* allprison, allprison_racct and lastprid are protected by allprison_lock. */
140 struct	sx allprison_lock;
141 SX_SYSINIT(allprison_lock, &allprison_lock, "allprison");
142 struct	prisonlist allprison = TAILQ_HEAD_INITIALIZER(allprison);
143 LIST_HEAD(, prison_racct) allprison_racct;
144 int	lastprid = 0;
145 int	lastdeadid = 0;
146 
147 static int get_next_prid(struct prison **insprp);
148 static int get_next_deadid(struct prison **insprp);
149 static int do_jail_attach(struct thread *td, struct prison *pr, int drflags);
150 static void prison_complete(void *context, int pending);
151 static void prison_deref(struct prison *pr, int flags);
152 static void prison_deref_kill(struct prison *pr, struct prisonlist *freeprison);
153 static int prison_lock_xlock(struct prison *pr, int flags);
154 static void prison_cleanup(struct prison *pr);
155 static void prison_free_not_last(struct prison *pr);
156 static void prison_proc_free_not_last(struct prison *pr);
157 static void prison_proc_relink(struct prison *opr, struct prison *npr,
158     struct proc *p);
159 static void prison_set_allow_locked(struct prison *pr, unsigned flag,
160     int enable);
161 static char *prison_path(struct prison *pr1, struct prison *pr2);
162 #ifdef RACCT
163 static void prison_racct_attach(struct prison *pr);
164 static void prison_racct_modify(struct prison *pr);
165 static void prison_racct_detach(struct prison *pr);
166 #endif
167 
168 /* Flags for prison_deref */
169 #define	PD_DEREF	0x01	/* Decrement pr_ref */
170 #define	PD_DEUREF	0x02	/* Decrement pr_uref */
171 #define	PD_KILL		0x04	/* Remove jail, kill processes, etc */
172 #define	PD_LOCKED	0x10	/* pr_mtx is held */
173 #define	PD_LIST_SLOCKED	0x20	/* allprison_lock is held shared */
174 #define	PD_LIST_XLOCKED	0x40	/* allprison_lock is held exclusive */
175 #define PD_OP_FLAGS	0x07	/* Operation flags */
176 #define PD_LOCK_FLAGS	0x70	/* Lock status flags */
177 
178 /*
179  * Parameter names corresponding to PR_* flag values.  Size values are for kvm
180  * as we cannot figure out the size of a sparse array, or an array without a
181  * terminating entry.
182  */
183 static struct bool_flags pr_flag_bool[] = {
184 	{"persist", "nopersist", PR_PERSIST},
185 #ifdef INET
186 	{"ip4.saddrsel", "ip4.nosaddrsel", PR_IP4_SADDRSEL},
187 #endif
188 #ifdef INET6
189 	{"ip6.saddrsel", "ip6.nosaddrsel", PR_IP6_SADDRSEL},
190 #endif
191 };
192 const size_t pr_flag_bool_size = sizeof(pr_flag_bool);
193 
194 static struct jailsys_flags pr_flag_jailsys[] = {
195 	{"host", 0, PR_HOST},
196 #ifdef VIMAGE
197 	{"vnet", 0, PR_VNET},
198 #endif
199 #ifdef INET
200 	{"ip4", PR_IP4_USER, PR_IP4_USER},
201 #endif
202 #ifdef INET6
203 	{"ip6", PR_IP6_USER, PR_IP6_USER},
204 #endif
205 };
206 const size_t pr_flag_jailsys_size = sizeof(pr_flag_jailsys);
207 
208 /*
209  * Make this array full-size so dynamic parameters can be added.
210  * It is protected by prison0.mtx, but lockless reading is allowed
211  * with an atomic check of the flag values.
212  */
213 static struct bool_flags pr_flag_allow[NBBY * NBPW] = {
214 	{"allow.set_hostname", "allow.noset_hostname", PR_ALLOW_SET_HOSTNAME},
215 	{"allow.sysvipc", "allow.nosysvipc", PR_ALLOW_SYSVIPC},
216 	{"allow.raw_sockets", "allow.noraw_sockets", PR_ALLOW_RAW_SOCKETS},
217 	{"allow.chflags", "allow.nochflags", PR_ALLOW_CHFLAGS},
218 	{"allow.mount", "allow.nomount", PR_ALLOW_MOUNT},
219 	{"allow.quotas", "allow.noquotas", PR_ALLOW_QUOTAS},
220 	{"allow.socket_af", "allow.nosocket_af", PR_ALLOW_SOCKET_AF},
221 	{"allow.mlock", "allow.nomlock", PR_ALLOW_MLOCK},
222 	{"allow.reserved_ports", "allow.noreserved_ports",
223 	 PR_ALLOW_RESERVED_PORTS},
224 	{"allow.read_msgbuf", "allow.noread_msgbuf", PR_ALLOW_READ_MSGBUF},
225 	{"allow.unprivileged_proc_debug", "allow.nounprivileged_proc_debug",
226 	 PR_ALLOW_UNPRIV_DEBUG},
227 	{"allow.suser", "allow.nosuser", PR_ALLOW_SUSER},
228 #ifdef VIMAGE
229 	{"allow.nfsd", "allow.nonfsd", PR_ALLOW_NFSD},
230 #endif
231 	{"allow.extattr", "allow.noextattr", PR_ALLOW_EXTATTR},
232 	{"allow.adjtime", "allow.noadjtime", PR_ALLOW_ADJTIME},
233 	{"allow.settime", "allow.nosettime", PR_ALLOW_SETTIME},
234 };
235 static unsigned pr_allow_all = PR_ALLOW_ALL_STATIC;
236 const size_t pr_flag_allow_size = sizeof(pr_flag_allow);
237 
238 #define	JAIL_DEFAULT_ALLOW		(PR_ALLOW_SET_HOSTNAME | \
239 					 PR_ALLOW_RESERVED_PORTS | \
240 					 PR_ALLOW_UNPRIV_DEBUG | \
241 					 PR_ALLOW_SUSER)
242 #define	JAIL_DEFAULT_ENFORCE_STATFS	2
243 #define	JAIL_DEFAULT_DEVFS_RSNUM	0
244 static unsigned jail_default_allow = JAIL_DEFAULT_ALLOW;
245 static int jail_default_enforce_statfs = JAIL_DEFAULT_ENFORCE_STATFS;
246 static int jail_default_devfs_rsnum = JAIL_DEFAULT_DEVFS_RSNUM;
247 #if defined(INET) || defined(INET6)
248 static unsigned jail_max_af_ips = 255;
249 #endif
250 
251 /*
252  * Initialize the parts of prison0 that can't be static-initialized with
253  * constants.  This is called from proc0_init() after creating thread0 cpuset.
254  */
255 void
prison0_init(void)256 prison0_init(void)
257 {
258 	uint8_t *file, *data;
259 	size_t size;
260 	char buf[sizeof(prison0.pr_hostuuid)];
261 	bool valid;
262 
263 	prison0.pr_cpuset = cpuset_ref(thread0.td_cpuset);
264 	prison0.pr_osreldate = osreldate;
265 	strlcpy(prison0.pr_osrelease, osrelease, sizeof(prison0.pr_osrelease));
266 
267 	/* If we have a preloaded hostuuid, use it. */
268 	file = preload_search_by_type(PRISON0_HOSTUUID_MODULE);
269 	if (file != NULL) {
270 		data = preload_fetch_addr(file);
271 		size = preload_fetch_size(file);
272 		if (data != NULL) {
273 			/*
274 			 * The preloaded data may include trailing whitespace, almost
275 			 * certainly a newline; skip over any whitespace or
276 			 * non-printable characters to be safe.
277 			 */
278 			while (size > 0 && data[size - 1] <= 0x20) {
279 				size--;
280 			}
281 
282 			valid = false;
283 
284 			/*
285 			 * Not NUL-terminated when passed from loader, but
286 			 * validate_uuid requires that due to using sscanf (as
287 			 * does the subsequent strlcpy, since it still reads
288 			 * past the given size to return the true length);
289 			 * bounce to a temporary buffer to fix.
290 			 */
291 			if (size >= sizeof(buf))
292 				goto done;
293 
294 			memcpy(buf, data, size);
295 			buf[size] = '\0';
296 
297 			if (validate_uuid(buf, size, NULL, 0) != 0)
298 				goto done;
299 
300 			valid = true;
301 			(void)strlcpy(prison0.pr_hostuuid, buf,
302 			    sizeof(prison0.pr_hostuuid));
303 
304 done:
305 			if (bootverbose && !valid) {
306 				printf("hostuuid: preload data malformed: '%.*s'\n",
307 				    (int)size, data);
308 			}
309 		}
310 	}
311 	if (bootverbose)
312 		printf("hostuuid: using %s\n", prison0.pr_hostuuid);
313 }
314 
315 /*
316  * struct jail_args {
317  *	struct jail *jail;
318  * };
319  */
320 int
sys_jail(struct thread * td,struct jail_args * uap)321 sys_jail(struct thread *td, struct jail_args *uap)
322 {
323 	uint32_t version;
324 	int error;
325 	struct jail j;
326 
327 	error = copyin(uap->jail, &version, sizeof(uint32_t));
328 	if (error)
329 		return (error);
330 
331 	switch (version) {
332 	case 0:
333 	{
334 		struct jail_v0 j0;
335 
336 		/* FreeBSD single IPv4 jails. */
337 		bzero(&j, sizeof(struct jail));
338 		error = copyin(uap->jail, &j0, sizeof(struct jail_v0));
339 		if (error)
340 			return (error);
341 		j.version = j0.version;
342 		j.path = j0.path;
343 		j.hostname = j0.hostname;
344 		j.ip4s = htonl(j0.ip_number);	/* jail_v0 is host order */
345 		break;
346 	}
347 
348 	case 1:
349 		/*
350 		 * Version 1 was used by multi-IPv4 jail implementations
351 		 * that never made it into the official kernel.
352 		 */
353 		return (EINVAL);
354 
355 	case 2:	/* JAIL_API_VERSION */
356 		/* FreeBSD multi-IPv4/IPv6,noIP jails. */
357 		error = copyin(uap->jail, &j, sizeof(struct jail));
358 		if (error)
359 			return (error);
360 		break;
361 
362 	default:
363 		/* Sci-Fi jails are not supported, sorry. */
364 		return (EINVAL);
365 	}
366 	return (kern_jail(td, &j));
367 }
368 
369 int
kern_jail(struct thread * td,struct jail * j)370 kern_jail(struct thread *td, struct jail *j)
371 {
372 	struct iovec optiov[2 * (4 + nitems(pr_flag_allow)
373 #ifdef INET
374 			    + 1
375 #endif
376 #ifdef INET6
377 			    + 1
378 #endif
379 			    )];
380 	struct uio opt;
381 	char *u_path, *u_hostname, *u_name;
382 	struct bool_flags *bf;
383 #ifdef INET
384 	uint32_t ip4s;
385 	struct in_addr *u_ip4;
386 #endif
387 #ifdef INET6
388 	struct in6_addr *u_ip6;
389 #endif
390 	size_t tmplen;
391 	int error, enforce_statfs;
392 
393 	bzero(&optiov, sizeof(optiov));
394 	opt.uio_iov = optiov;
395 	opt.uio_iovcnt = 0;
396 	opt.uio_offset = -1;
397 	opt.uio_resid = -1;
398 	opt.uio_segflg = UIO_SYSSPACE;
399 	opt.uio_rw = UIO_READ;
400 	opt.uio_td = td;
401 
402 	/* Set permissions for top-level jails from sysctls. */
403 	if (!jailed(td->td_ucred)) {
404 		for (bf = pr_flag_allow;
405 		     bf < pr_flag_allow + nitems(pr_flag_allow) &&
406 			atomic_load_int(&bf->flag) != 0;
407 		     bf++) {
408 			optiov[opt.uio_iovcnt].iov_base = __DECONST(char *,
409 			    (jail_default_allow & bf->flag)
410 			    ? bf->name : bf->noname);
411 			optiov[opt.uio_iovcnt].iov_len =
412 			    strlen(optiov[opt.uio_iovcnt].iov_base) + 1;
413 			opt.uio_iovcnt += 2;
414 		}
415 		optiov[opt.uio_iovcnt].iov_base = "enforce_statfs";
416 		optiov[opt.uio_iovcnt].iov_len = sizeof("enforce_statfs");
417 		opt.uio_iovcnt++;
418 		enforce_statfs = jail_default_enforce_statfs;
419 		optiov[opt.uio_iovcnt].iov_base = &enforce_statfs;
420 		optiov[opt.uio_iovcnt].iov_len = sizeof(enforce_statfs);
421 		opt.uio_iovcnt++;
422 	}
423 
424 	tmplen = MAXPATHLEN + MAXHOSTNAMELEN + MAXHOSTNAMELEN;
425 #ifdef INET
426 	ip4s = (j->version == 0) ? 1 : j->ip4s;
427 	if (ip4s > jail_max_af_ips)
428 		return (EINVAL);
429 	tmplen += ip4s * sizeof(struct in_addr);
430 #else
431 	if (j->ip4s > 0)
432 		return (EINVAL);
433 #endif
434 #ifdef INET6
435 	if (j->ip6s > jail_max_af_ips)
436 		return (EINVAL);
437 	tmplen += j->ip6s * sizeof(struct in6_addr);
438 #else
439 	if (j->ip6s > 0)
440 		return (EINVAL);
441 #endif
442 	u_path = malloc(tmplen, M_TEMP, M_WAITOK);
443 	u_hostname = u_path + MAXPATHLEN;
444 	u_name = u_hostname + MAXHOSTNAMELEN;
445 #ifdef INET
446 	u_ip4 = (struct in_addr *)(u_name + MAXHOSTNAMELEN);
447 #endif
448 #ifdef INET6
449 #ifdef INET
450 	u_ip6 = (struct in6_addr *)(u_ip4 + ip4s);
451 #else
452 	u_ip6 = (struct in6_addr *)(u_name + MAXHOSTNAMELEN);
453 #endif
454 #endif
455 	optiov[opt.uio_iovcnt].iov_base = "path";
456 	optiov[opt.uio_iovcnt].iov_len = sizeof("path");
457 	opt.uio_iovcnt++;
458 	optiov[opt.uio_iovcnt].iov_base = u_path;
459 	error = copyinstr(j->path, u_path, MAXPATHLEN,
460 	    &optiov[opt.uio_iovcnt].iov_len);
461 	if (error) {
462 		free(u_path, M_TEMP);
463 		return (error);
464 	}
465 	opt.uio_iovcnt++;
466 	optiov[opt.uio_iovcnt].iov_base = "host.hostname";
467 	optiov[opt.uio_iovcnt].iov_len = sizeof("host.hostname");
468 	opt.uio_iovcnt++;
469 	optiov[opt.uio_iovcnt].iov_base = u_hostname;
470 	error = copyinstr(j->hostname, u_hostname, MAXHOSTNAMELEN,
471 	    &optiov[opt.uio_iovcnt].iov_len);
472 	if (error) {
473 		free(u_path, M_TEMP);
474 		return (error);
475 	}
476 	opt.uio_iovcnt++;
477 	if (j->jailname != NULL) {
478 		optiov[opt.uio_iovcnt].iov_base = "name";
479 		optiov[opt.uio_iovcnt].iov_len = sizeof("name");
480 		opt.uio_iovcnt++;
481 		optiov[opt.uio_iovcnt].iov_base = u_name;
482 		error = copyinstr(j->jailname, u_name, MAXHOSTNAMELEN,
483 		    &optiov[opt.uio_iovcnt].iov_len);
484 		if (error) {
485 			free(u_path, M_TEMP);
486 			return (error);
487 		}
488 		opt.uio_iovcnt++;
489 	}
490 #ifdef INET
491 	optiov[opt.uio_iovcnt].iov_base = "ip4.addr";
492 	optiov[opt.uio_iovcnt].iov_len = sizeof("ip4.addr");
493 	opt.uio_iovcnt++;
494 	optiov[opt.uio_iovcnt].iov_base = u_ip4;
495 	optiov[opt.uio_iovcnt].iov_len = ip4s * sizeof(struct in_addr);
496 	if (j->version == 0)
497 		u_ip4->s_addr = j->ip4s;
498 	else {
499 		error = copyin(j->ip4, u_ip4, optiov[opt.uio_iovcnt].iov_len);
500 		if (error) {
501 			free(u_path, M_TEMP);
502 			return (error);
503 		}
504 	}
505 	opt.uio_iovcnt++;
506 #endif
507 #ifdef INET6
508 	optiov[opt.uio_iovcnt].iov_base = "ip6.addr";
509 	optiov[opt.uio_iovcnt].iov_len = sizeof("ip6.addr");
510 	opt.uio_iovcnt++;
511 	optiov[opt.uio_iovcnt].iov_base = u_ip6;
512 	optiov[opt.uio_iovcnt].iov_len = j->ip6s * sizeof(struct in6_addr);
513 	error = copyin(j->ip6, u_ip6, optiov[opt.uio_iovcnt].iov_len);
514 	if (error) {
515 		free(u_path, M_TEMP);
516 		return (error);
517 	}
518 	opt.uio_iovcnt++;
519 #endif
520 	KASSERT(opt.uio_iovcnt <= nitems(optiov),
521 		("kern_jail: too many iovecs (%d)", opt.uio_iovcnt));
522 	error = kern_jail_set(td, &opt, JAIL_CREATE | JAIL_ATTACH);
523 	free(u_path, M_TEMP);
524 	return (error);
525 }
526 
527 /*
528  * struct jail_set_args {
529  *	struct iovec *iovp;
530  *	unsigned int iovcnt;
531  *	int flags;
532  * };
533  */
534 int
sys_jail_set(struct thread * td,struct jail_set_args * uap)535 sys_jail_set(struct thread *td, struct jail_set_args *uap)
536 {
537 	struct uio *auio;
538 	int error;
539 
540 	/* Check that we have an even number of iovecs. */
541 	if (uap->iovcnt & 1)
542 		return (EINVAL);
543 
544 	error = copyinuio(uap->iovp, uap->iovcnt, &auio);
545 	if (error)
546 		return (error);
547 	error = kern_jail_set(td, auio, uap->flags);
548 	freeuio(auio);
549 	return (error);
550 }
551 
552 #if defined(INET) || defined(INET6)
553 typedef int prison_addr_cmp_t(const void *, const void *);
554 typedef bool prison_addr_valid_t(const void *);
555 static const struct pr_family {
556 	size_t			size;
557 	prison_addr_cmp_t	*cmp;
558 	prison_addr_valid_t	*valid;
559 	int			ip_flag;
560 } pr_families[PR_FAMILY_MAX] = {
561 #ifdef INET
562 	[PR_INET] = {
563 		.size = sizeof(struct in_addr),
564 		.cmp = prison_qcmp_v4,
565 		.valid = prison_valid_v4,
566 		.ip_flag = PR_IP4_USER,
567 	 },
568 #endif
569 #ifdef INET6
570 	[PR_INET6] = {
571 		.size = sizeof(struct in6_addr),
572 		.cmp = prison_qcmp_v6,
573 		.valid = prison_valid_v6,
574 		.ip_flag = PR_IP6_USER,
575 	},
576 #endif
577 };
578 
579 /*
580  * Network address lists (pr_addrs) allocation for jails.  The addresses
581  * are accessed locklessly by the network stack, thus need to be protected by
582  * the network epoch.
583  */
584 struct prison_ip {
585 	struct epoch_context ctx;
586 	uint32_t	ips;
587 #ifdef FUTURE_C
588 	/*
589 	 * XXX Variable-length automatic arrays in union may be
590 	 * supported in future C.
591 	 */
592 	union {
593 		char pr_ip[];
594 		struct in_addr pr_ip4[];
595 		struct in6_addr pr_ip6[];
596 	};
597 #else /* No future C :( */
598 	char pr_ip[];
599 #endif
600 };
601 
602 static char *
PR_IP(struct prison_ip * pip,const pr_family_t af,int idx)603 PR_IP(struct prison_ip *pip, const pr_family_t af, int idx)
604 {
605 	MPASS(pip);
606 	MPASS(af < PR_FAMILY_MAX);
607 	MPASS(idx >= 0 && idx < pip->ips);
608 
609 	return (pip->pr_ip + pr_families[af].size * idx);
610 }
611 
612 static struct prison_ip *
prison_ip_alloc(const pr_family_t af,uint32_t cnt,int flags)613 prison_ip_alloc(const pr_family_t af, uint32_t cnt, int flags)
614 {
615 	struct prison_ip *pip;
616 
617 	pip = malloc(sizeof(struct prison_ip) + cnt * pr_families[af].size,
618 	    M_PRISON, flags);
619 	if (pip != NULL)
620 		pip->ips = cnt;
621 	return (pip);
622 }
623 
624 /*
625  * Allocate and copyin user supplied address list, sorting and validating.
626  * kern_jail_set() helper.
627  */
628 static struct prison_ip *
prison_ip_copyin(const pr_family_t af,void * op,uint32_t cnt)629 prison_ip_copyin(const pr_family_t af, void *op, uint32_t cnt)
630 {
631 	prison_addr_cmp_t *const cmp = pr_families[af].cmp;
632 	const size_t size = pr_families[af].size;
633 	struct prison_ip *pip;
634 
635 	pip = prison_ip_alloc(af, cnt, M_WAITOK);
636 	bcopy(op, pip->pr_ip, cnt * size);
637 	/*
638 	 * IP addresses are all sorted but ip[0] to preserve
639 	 * the primary IP address as given from userland.
640 	 * This special IP is used for unbound outgoing
641 	 * connections as well for "loopback" traffic in case
642 	 * source address selection cannot find any more fitting
643 	 * address to connect from.
644 	 */
645 	if (cnt > 1)
646 		qsort(PR_IP(pip, af, 1), cnt - 1, size, cmp);
647 	/*
648 	 * Check for duplicate addresses and do some simple
649 	 * zero and broadcast checks. If users give other bogus
650 	 * addresses it is their problem.
651 	 */
652 	for (int i = 0; i < cnt; i++) {
653 		if (!pr_families[af].valid(PR_IP(pip, af, i))) {
654 			free(pip, M_PRISON);
655 			return (NULL);
656 		}
657 		if (i + 1 < cnt &&
658 		    (cmp(PR_IP(pip, af, 0), PR_IP(pip, af, i + 1)) == 0 ||
659 		     cmp(PR_IP(pip, af, i), PR_IP(pip, af, i + 1)) == 0)) {
660 			free(pip, M_PRISON);
661 			return (NULL);
662 		}
663 	}
664 
665 	return (pip);
666 }
667 
668 /*
669  * Allocate and dup parent prison address list.
670  * kern_jail_set() helper.
671  */
672 static void
prison_ip_dup(struct prison * ppr,struct prison * pr,const pr_family_t af)673 prison_ip_dup(struct prison *ppr, struct prison *pr, const pr_family_t af)
674 {
675 	const struct prison_ip *ppip = ppr->pr_addrs[af];
676 	struct prison_ip *pip;
677 
678 	if (ppip != NULL) {
679 		pip = prison_ip_alloc(af, ppip->ips, M_WAITOK);
680 		bcopy(ppip->pr_ip, pip->pr_ip, pip->ips * pr_families[af].size);
681 		pr->pr_addrs[af] = pip;
682 	}
683 }
684 
685 /*
686  * Make sure the new set of IP addresses is a subset of the parent's list.
687  * Don't worry about the parent being unlocked, as any setting is done with
688  * allprison_lock held.
689  * kern_jail_set() helper.
690  */
691 static bool
prison_ip_parent_match(struct prison_ip * ppip,struct prison_ip * pip,const pr_family_t af)692 prison_ip_parent_match(struct prison_ip *ppip, struct prison_ip *pip,
693     const pr_family_t af)
694 {
695 	prison_addr_cmp_t *const cmp = pr_families[af].cmp;
696 	int i, j;
697 
698 	if (ppip == NULL)
699 		return (false);
700 
701 	for (i = 0; i < ppip->ips; i++)
702 		if (cmp(PR_IP(pip, af, 0), PR_IP(ppip, af, i)) == 0)
703 			break;
704 
705 	if (i == ppip->ips)
706 		/* Main address not present in parent. */
707 		return (false);
708 
709 	if (pip->ips > 1) {
710 		for (i = j = 1; i < pip->ips; i++) {
711 			if (cmp(PR_IP(pip, af, i), PR_IP(ppip, af, 0)) == 0)
712 				/* Equals to parent primary address. */
713 				continue;
714 			for (; j < ppip->ips; j++)
715 				if (cmp(PR_IP(pip, af, i),
716 				    PR_IP(ppip, af, j)) == 0)
717 					break;
718 			if (j == ppip->ips)
719 				break;
720 		}
721 		if (j == ppip->ips)
722 			/* Address not present in parent. */
723 			return (false);
724 	}
725 	return (true);
726 }
727 
728 /*
729  * Check for conflicting IP addresses.  We permit them if there is no more
730  * than one IP on each jail.  If there is a duplicate on a jail with more
731  * than one IP stop checking and return error.
732  * kern_jail_set() helper.
733  */
734 static bool
prison_ip_conflict_check(const struct prison * ppr,const struct prison * pr,struct prison_ip * pip,pr_family_t af)735 prison_ip_conflict_check(const struct prison *ppr, const struct prison *pr,
736     struct prison_ip *pip, pr_family_t af)
737 {
738 	const struct prison *tppr, *tpr;
739 	int descend;
740 
741 #ifdef VIMAGE
742 	for (tppr = ppr; tppr != &prison0; tppr = tppr->pr_parent)
743 		if (tppr->pr_flags & PR_VNET)
744 			break;
745 #else
746 	tppr = &prison0;
747 #endif
748 	FOREACH_PRISON_DESCENDANT(tppr, tpr, descend) {
749 		if (tpr == pr ||
750 #ifdef VIMAGE
751 		    (tpr != tppr && (tpr->pr_flags & PR_VNET)) ||
752 #endif
753 		    !prison_isalive(tpr)) {
754 			descend = 0;
755 			continue;
756 		}
757 		if (!(tpr->pr_flags & pr_families[af].ip_flag))
758 			continue;
759 		descend = 0;
760 		if (tpr->pr_addrs[af] == NULL ||
761 		    (pip->ips == 1 && tpr->pr_addrs[af]->ips == 1))
762 			continue;
763 		for (int i = 0; i < pip->ips; i++)
764 			if (prison_ip_check(tpr, af, PR_IP(pip, af, i)) == 0)
765 				return (false);
766 	}
767 
768 	return (true);
769 }
770 
771 _Static_assert(offsetof(struct prison_ip, ctx) == 0,
772     "prison must start with epoch context");
773 static void
prison_ip_free_deferred(epoch_context_t ctx)774 prison_ip_free_deferred(epoch_context_t ctx)
775 {
776 
777 	free(ctx, M_PRISON);
778 }
779 
780 static void
prison_ip_free(struct prison_ip * pip)781 prison_ip_free(struct prison_ip *pip)
782 {
783 
784 	if (pip != NULL)
785 		NET_EPOCH_CALL(prison_ip_free_deferred, &pip->ctx);
786 }
787 
788 static void
prison_ip_set(struct prison * pr,const pr_family_t af,struct prison_ip * new)789 prison_ip_set(struct prison *pr, const pr_family_t af, struct prison_ip *new)
790 {
791 	struct prison_ip **mem, *old;
792 
793 	mtx_assert(&pr->pr_mtx, MA_OWNED);
794 
795 	mem = &pr->pr_addrs[af];
796 
797 	old = *mem;
798 	atomic_store_ptr(mem, new);
799 	prison_ip_free(old);
800 }
801 
802 /*
803  * Restrict a prison's IP address list with its parent's, possibly replacing
804  * it.  Return true if succeed, otherwise should redo.
805  * kern_jail_set() helper.
806  */
807 static bool
prison_ip_restrict(struct prison * pr,const pr_family_t af,struct prison_ip ** newp)808 prison_ip_restrict(struct prison *pr, const pr_family_t af,
809     struct prison_ip **newp)
810 {
811 	struct prison_ip *ppip = pr->pr_parent->pr_addrs[af];
812 	struct prison_ip *pip = pr->pr_addrs[af];
813 	int (*const cmp)(const void *, const void *) = pr_families[af].cmp;
814 	const size_t size = pr_families[af].size;
815 	struct prison_ip *new = newp != NULL ? *newp : NULL;
816 	uint32_t ips;
817 
818 	mtx_assert(&pr->pr_mtx, MA_OWNED);
819 
820 	/*
821 	 * Due to epoch-synchronized access to the IP address lists we always
822 	 * allocate a new list even if the old one has enough space.  We could
823 	 * atomically update an IPv4 address inside a list, but that would
824 	 * screw up sorting, and in case of IPv6 we can't even atomically write
825 	 * one.
826 	 */
827 	if (ppip == NULL) {
828 		if (pip != NULL)
829 			prison_ip_set(pr, af, NULL);
830 		return (true);
831 	}
832 
833 	if (!(pr->pr_flags & pr_families[af].ip_flag)) {
834 		if (new == NULL) {
835 			new = prison_ip_alloc(af, ppip->ips, M_NOWAIT);
836 			if (new == NULL)
837 				return (false); /* Redo */
838 		}
839 		/* This has no user settings, so just copy the parent's list. */
840 		MPASS(new->ips == ppip->ips);
841 		bcopy(ppip->pr_ip, new->pr_ip, ppip->ips * size);
842 		prison_ip_set(pr, af, new);
843 		if (newp != NULL)
844 			*newp = NULL; /* Used */
845 	} else if (pip != NULL) {
846 		/* Remove addresses that aren't in the parent. */
847 		int i;
848 
849 		i = 0; /* index in pip */
850 		ips = 0; /* index in new */
851 
852 		if (new == NULL) {
853 			new = prison_ip_alloc(af, pip->ips, M_NOWAIT);
854 			if (new == NULL)
855 				return (false); /* Redo */
856 		}
857 
858 		for (int pi = 0; pi < ppip->ips; pi++)
859 			if (cmp(PR_IP(pip, af, 0), PR_IP(ppip, af, pi)) == 0) {
860 				/* Found our primary address in parent. */
861 				bcopy(PR_IP(pip, af, i), PR_IP(new, af, ips),
862 				    size);
863 				i++;
864 				ips++;
865 				break;
866 			}
867 		for (int pi = 1; i < pip->ips; ) {
868 			/* Check against primary, which is unsorted. */
869 			if (cmp(PR_IP(pip, af, i), PR_IP(ppip, af, 0)) == 0) {
870 				/* Matches parent's primary address. */
871 				bcopy(PR_IP(pip, af, i), PR_IP(new, af, ips),
872 				    size);
873 				i++;
874 				ips++;
875 				continue;
876 			}
877 			/* The rest are sorted. */
878 			switch (pi >= ppip->ips ? -1 :
879 				cmp(PR_IP(pip, af, i), PR_IP(ppip, af, pi))) {
880 			case -1:
881 				i++;
882 				break;
883 			case 0:
884 				bcopy(PR_IP(pip, af, i), PR_IP(new, af, ips),
885 				    size);
886 				i++;
887 				pi++;
888 				ips++;
889 				break;
890 			case 1:
891 				pi++;
892 				break;
893 			}
894 		}
895 		if (ips == 0) {
896 			if (newp == NULL || *newp == NULL)
897 				prison_ip_free(new);
898 			new = NULL;
899 		} else {
900 			/* Shrink to real size */
901 			KASSERT((new->ips >= ips),
902 			    ("Out-of-bounds write to prison_ip %p", new));
903 			new->ips = ips;
904 		}
905 		prison_ip_set(pr, af, new);
906 		if (newp != NULL)
907 			*newp = NULL; /* Used */
908 	}
909 	return (true);
910 }
911 
912 /*
913  * Fast-path check if an address belongs to a prison.
914  */
915 int
prison_ip_check(const struct prison * pr,const pr_family_t af,const void * addr)916 prison_ip_check(const struct prison *pr, const pr_family_t af,
917     const void *addr)
918 {
919 	int (*const cmp)(const void *, const void *) = pr_families[af].cmp;
920 	struct prison_ip *pip;
921 	int i, a, z, d;
922 
923 	MPASS(mtx_owned(&pr->pr_mtx) ||
924 	    in_epoch(net_epoch_preempt) ||
925 	    sx_xlocked(&allprison_lock));
926 
927 	pip = atomic_load_ptr(&pr->pr_addrs[af]);
928 	if (__predict_false(pip == NULL))
929 		return (EAFNOSUPPORT);
930 
931 	/* Check the primary IP. */
932 	if (cmp(PR_IP(pip, af, 0), addr) == 0)
933 		return (0);
934 
935 	/*
936 	 * All the other IPs are sorted so we can do a binary search.
937 	 */
938 	a = 0;
939 	z = pip->ips - 2;
940 	while (a <= z) {
941 		i = (a + z) / 2;
942 		d = cmp(PR_IP(pip, af, i + 1), addr);
943 		if (d > 0)
944 			z = i - 1;
945 		else if (d < 0)
946 			a = i + 1;
947 		else
948 			return (0);
949 	}
950 
951 	return (EADDRNOTAVAIL);
952 }
953 
954 /*
955  * Grab primary IP.  Historically required mutex, but nothing prevents
956  * us to support epoch-protected access.  Is it used in fast path?
957  * in{6}_jail.c helper
958  */
959 const void *
prison_ip_get0(const struct prison * pr,const pr_family_t af)960 prison_ip_get0(const struct prison *pr, const pr_family_t af)
961 {
962 	const struct prison_ip *pip = pr->pr_addrs[af];
963 
964 	mtx_assert(&pr->pr_mtx, MA_OWNED);
965 	MPASS(pip);
966 
967 	return (pip->pr_ip);
968 }
969 
970 u_int
prison_ip_cnt(const struct prison * pr,const pr_family_t af)971 prison_ip_cnt(const struct prison *pr, const pr_family_t af)
972 {
973 
974 	return (pr->pr_addrs[af]->ips);
975 }
976 #endif	/* defined(INET) || defined(INET6) */
977 
978 int
kern_jail_set(struct thread * td,struct uio * optuio,int flags)979 kern_jail_set(struct thread *td, struct uio *optuio, int flags)
980 {
981 	struct nameidata nd;
982 #ifdef INET
983 	struct prison_ip *ip4;
984 #endif
985 #ifdef INET6
986 	struct prison_ip *ip6;
987 #endif
988 	struct vfsopt *opt;
989 	struct vfsoptlist *opts;
990 	struct prison *pr, *deadpr, *dinspr, *inspr, *mypr, *ppr, *tpr;
991 	struct vnode *root;
992 	char *domain, *errmsg, *host, *name, *namelc, *p, *path, *uuid;
993 	char *g_path, *osrelstr;
994 	struct bool_flags *bf;
995 	struct jailsys_flags *jsf;
996 #if defined(INET) || defined(INET6)
997 	void *op;
998 #endif
999 	unsigned long hid;
1000 	size_t namelen, onamelen, pnamelen;
1001 	int created, cuflags, descend, drflags, enforce;
1002 	int error, errmsg_len, errmsg_pos;
1003 	int gotchildmax, gotenforce, gothid, gotrsnum, gotslevel;
1004 	int deadid, jid, jsys, len, level;
1005 	int childmax, osreldt, rsnum, slevel;
1006 #ifdef INET
1007 	int ip4s;
1008 	bool redo_ip4;
1009 #endif
1010 #ifdef INET6
1011 	int ip6s;
1012 	bool redo_ip6;
1013 #endif
1014 	uint64_t pr_allow, ch_allow, pr_flags, ch_flags;
1015 	uint64_t pr_allow_diff;
1016 	unsigned tallow;
1017 	char numbuf[12];
1018 
1019 	error = priv_check(td, PRIV_JAIL_SET);
1020 	if (!error && (flags & JAIL_ATTACH))
1021 		error = priv_check(td, PRIV_JAIL_ATTACH);
1022 	if (error)
1023 		return (error);
1024 	mypr = td->td_ucred->cr_prison;
1025 	if ((flags & JAIL_CREATE) && mypr->pr_childmax == 0)
1026 		return (EPERM);
1027 	if (flags & ~JAIL_SET_MASK)
1028 		return (EINVAL);
1029 
1030 	/*
1031 	 * Check all the parameters before committing to anything.  Not all
1032 	 * errors can be caught early, but we may as well try.  Also, this
1033 	 * takes care of some expensive stuff (path lookup) before getting
1034 	 * the allprison lock.
1035 	 *
1036 	 * XXX Jails are not filesystems, and jail parameters are not mount
1037 	 *     options.  But it makes more sense to re-use the vfsopt code
1038 	 *     than duplicate it under a different name.
1039 	 */
1040 	error = vfs_buildopts(optuio, &opts);
1041 	if (error)
1042 		return (error);
1043 #ifdef INET
1044 	ip4 = NULL;
1045 #endif
1046 #ifdef INET6
1047 	ip6 = NULL;
1048 #endif
1049 	g_path = NULL;
1050 
1051 	cuflags = flags & (JAIL_CREATE | JAIL_UPDATE);
1052 	if (!cuflags) {
1053 		error = EINVAL;
1054 		vfs_opterror(opts, "no valid operation (create or update)");
1055 		goto done_errmsg;
1056 	}
1057 
1058 	error = vfs_copyopt(opts, "jid", &jid, sizeof(jid));
1059 	if (error == ENOENT)
1060 		jid = 0;
1061 	else if (error != 0)
1062 		goto done_free;
1063 
1064 	error = vfs_copyopt(opts, "securelevel", &slevel, sizeof(slevel));
1065 	if (error == ENOENT)
1066 		gotslevel = 0;
1067 	else if (error != 0)
1068 		goto done_free;
1069 	else
1070 		gotslevel = 1;
1071 
1072 	error =
1073 	    vfs_copyopt(opts, "children.max", &childmax, sizeof(childmax));
1074 	if (error == ENOENT)
1075 		gotchildmax = 0;
1076 	else if (error != 0)
1077 		goto done_free;
1078 	else
1079 		gotchildmax = 1;
1080 
1081 	error = vfs_copyopt(opts, "enforce_statfs", &enforce, sizeof(enforce));
1082 	if (error == ENOENT)
1083 		gotenforce = 0;
1084 	else if (error != 0)
1085 		goto done_free;
1086 	else if (enforce < 0 || enforce > 2) {
1087 		error = EINVAL;
1088 		goto done_free;
1089 	} else
1090 		gotenforce = 1;
1091 
1092 	error = vfs_copyopt(opts, "devfs_ruleset", &rsnum, sizeof(rsnum));
1093 	if (error == ENOENT)
1094 		gotrsnum = 0;
1095 	else if (error != 0)
1096 		goto done_free;
1097 	else
1098 		gotrsnum = 1;
1099 
1100 	pr_flags = ch_flags = 0;
1101 	for (bf = pr_flag_bool;
1102 	     bf < pr_flag_bool + nitems(pr_flag_bool);
1103 	     bf++) {
1104 		vfs_flagopt(opts, bf->name, &pr_flags, bf->flag);
1105 		vfs_flagopt(opts, bf->noname, &ch_flags, bf->flag);
1106 	}
1107 	ch_flags |= pr_flags;
1108 	for (jsf = pr_flag_jailsys;
1109 	     jsf < pr_flag_jailsys + nitems(pr_flag_jailsys);
1110 	     jsf++) {
1111 		error = vfs_copyopt(opts, jsf->name, &jsys, sizeof(jsys));
1112 		if (error == ENOENT)
1113 			continue;
1114 		if (error != 0)
1115 			goto done_free;
1116 		switch (jsys) {
1117 		case JAIL_SYS_DISABLE:
1118 			if (!jsf->disable) {
1119 				error = EINVAL;
1120 				goto done_free;
1121 			}
1122 			pr_flags |= jsf->disable;
1123 			break;
1124 		case JAIL_SYS_NEW:
1125 			pr_flags |= jsf->new;
1126 			break;
1127 		case JAIL_SYS_INHERIT:
1128 			break;
1129 		default:
1130 			error = EINVAL;
1131 			goto done_free;
1132 		}
1133 		ch_flags |= jsf->new | jsf->disable;
1134 	}
1135 	if ((flags & (JAIL_CREATE | JAIL_ATTACH)) == JAIL_CREATE
1136 	    && !(pr_flags & PR_PERSIST)) {
1137 		error = EINVAL;
1138 		vfs_opterror(opts, "new jail must persist or attach");
1139 		goto done_errmsg;
1140 	}
1141 #ifdef VIMAGE
1142 	if ((flags & JAIL_UPDATE) && (ch_flags & PR_VNET)) {
1143 		error = EINVAL;
1144 		vfs_opterror(opts, "vnet cannot be changed after creation");
1145 		goto done_errmsg;
1146 	}
1147 #endif
1148 #ifdef INET
1149 	if ((flags & JAIL_UPDATE) && (ch_flags & PR_IP4_USER)) {
1150 		error = EINVAL;
1151 		vfs_opterror(opts, "ip4 cannot be changed after creation");
1152 		goto done_errmsg;
1153 	}
1154 #endif
1155 #ifdef INET6
1156 	if ((flags & JAIL_UPDATE) && (ch_flags & PR_IP6_USER)) {
1157 		error = EINVAL;
1158 		vfs_opterror(opts, "ip6 cannot be changed after creation");
1159 		goto done_errmsg;
1160 	}
1161 #endif
1162 
1163 	pr_allow = ch_allow = 0;
1164 	for (bf = pr_flag_allow;
1165 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
1166 		atomic_load_int(&bf->flag) != 0;
1167 	     bf++) {
1168 		vfs_flagopt(opts, bf->name, &pr_allow, bf->flag);
1169 		vfs_flagopt(opts, bf->noname, &ch_allow, bf->flag);
1170 	}
1171 	ch_allow |= pr_allow;
1172 
1173 	error = vfs_getopt(opts, "name", (void **)&name, &len);
1174 	if (error == ENOENT)
1175 		name = NULL;
1176 	else if (error != 0)
1177 		goto done_free;
1178 	else {
1179 		if (len == 0 || name[len - 1] != '\0') {
1180 			error = EINVAL;
1181 			goto done_free;
1182 		}
1183 		if (len > MAXHOSTNAMELEN) {
1184 			error = ENAMETOOLONG;
1185 			goto done_free;
1186 		}
1187 	}
1188 
1189 	error = vfs_getopt(opts, "host.hostname", (void **)&host, &len);
1190 	if (error == ENOENT)
1191 		host = NULL;
1192 	else if (error != 0)
1193 		goto done_free;
1194 	else {
1195 		ch_flags |= PR_HOST;
1196 		pr_flags |= PR_HOST;
1197 		if (len == 0 || host[len - 1] != '\0') {
1198 			error = EINVAL;
1199 			goto done_free;
1200 		}
1201 		if (len > MAXHOSTNAMELEN) {
1202 			error = ENAMETOOLONG;
1203 			goto done_free;
1204 		}
1205 	}
1206 
1207 	error = vfs_getopt(opts, "host.domainname", (void **)&domain, &len);
1208 	if (error == ENOENT)
1209 		domain = NULL;
1210 	else if (error != 0)
1211 		goto done_free;
1212 	else {
1213 		ch_flags |= PR_HOST;
1214 		pr_flags |= PR_HOST;
1215 		if (len == 0 || domain[len - 1] != '\0') {
1216 			error = EINVAL;
1217 			goto done_free;
1218 		}
1219 		if (len > MAXHOSTNAMELEN) {
1220 			error = ENAMETOOLONG;
1221 			goto done_free;
1222 		}
1223 	}
1224 
1225 	error = vfs_getopt(opts, "host.hostuuid", (void **)&uuid, &len);
1226 	if (error == ENOENT)
1227 		uuid = NULL;
1228 	else if (error != 0)
1229 		goto done_free;
1230 	else {
1231 		ch_flags |= PR_HOST;
1232 		pr_flags |= PR_HOST;
1233 		if (len == 0 || uuid[len - 1] != '\0') {
1234 			error = EINVAL;
1235 			goto done_free;
1236 		}
1237 		if (len > HOSTUUIDLEN) {
1238 			error = ENAMETOOLONG;
1239 			goto done_free;
1240 		}
1241 	}
1242 
1243 #ifdef COMPAT_FREEBSD32
1244 	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
1245 		uint32_t hid32;
1246 
1247 		error = vfs_copyopt(opts, "host.hostid", &hid32, sizeof(hid32));
1248 		hid = hid32;
1249 	} else
1250 #endif
1251 		error = vfs_copyopt(opts, "host.hostid", &hid, sizeof(hid));
1252 	if (error == ENOENT)
1253 		gothid = 0;
1254 	else if (error != 0)
1255 		goto done_free;
1256 	else {
1257 		gothid = 1;
1258 		ch_flags |= PR_HOST;
1259 		pr_flags |= PR_HOST;
1260 	}
1261 
1262 #ifdef INET
1263 	error = vfs_getopt(opts, "ip4.addr", &op, &ip4s);
1264 	if (error == ENOENT)
1265 		ip4s = 0;
1266 	else if (error != 0)
1267 		goto done_free;
1268 	else if (ip4s & (sizeof(struct in_addr) - 1)) {
1269 		error = EINVAL;
1270 		goto done_free;
1271 	} else {
1272 		ch_flags |= PR_IP4_USER;
1273 		pr_flags |= PR_IP4_USER;
1274 		if (ip4s > 0) {
1275 			ip4s /= sizeof(struct in_addr);
1276 			if (ip4s > jail_max_af_ips) {
1277 				error = EINVAL;
1278 				vfs_opterror(opts, "too many IPv4 addresses");
1279 				goto done_errmsg;
1280 			}
1281 			ip4 = prison_ip_copyin(PR_INET, op, ip4s);
1282 			if (ip4 == NULL) {
1283 				error = EINVAL;
1284 				goto done_free;
1285 			}
1286 		}
1287 	}
1288 #endif
1289 
1290 #ifdef INET6
1291 	error = vfs_getopt(opts, "ip6.addr", &op, &ip6s);
1292 	if (error == ENOENT)
1293 		ip6s = 0;
1294 	else if (error != 0)
1295 		goto done_free;
1296 	else if (ip6s & (sizeof(struct in6_addr) - 1)) {
1297 		error = EINVAL;
1298 		goto done_free;
1299 	} else {
1300 		ch_flags |= PR_IP6_USER;
1301 		pr_flags |= PR_IP6_USER;
1302 		if (ip6s > 0) {
1303 			ip6s /= sizeof(struct in6_addr);
1304 			if (ip6s > jail_max_af_ips) {
1305 				error = EINVAL;
1306 				vfs_opterror(opts, "too many IPv6 addresses");
1307 				goto done_errmsg;
1308 			}
1309 			ip6 = prison_ip_copyin(PR_INET6, op, ip6s);
1310 			if (ip6 == NULL) {
1311 				error = EINVAL;
1312 				goto done_free;
1313 			}
1314 		}
1315 	}
1316 #endif
1317 
1318 #if defined(VIMAGE) && (defined(INET) || defined(INET6))
1319 	if ((ch_flags & PR_VNET) && (ch_flags & (PR_IP4_USER | PR_IP6_USER))) {
1320 		error = EINVAL;
1321 		vfs_opterror(opts,
1322 		    "vnet jails cannot have IP address restrictions");
1323 		goto done_errmsg;
1324 	}
1325 #endif
1326 
1327 	error = vfs_getopt(opts, "osrelease", (void **)&osrelstr, &len);
1328 	if (error == ENOENT)
1329 		osrelstr = NULL;
1330 	else if (error != 0)
1331 		goto done_free;
1332 	else {
1333 		if (flags & JAIL_UPDATE) {
1334 			error = EINVAL;
1335 			vfs_opterror(opts,
1336 			    "osrelease cannot be changed after creation");
1337 			goto done_errmsg;
1338 		}
1339 		if (len == 0 || osrelstr[len - 1] != '\0') {
1340 			error = EINVAL;
1341 			goto done_free;
1342 		}
1343 		if (len >= OSRELEASELEN) {
1344 			error = ENAMETOOLONG;
1345 			vfs_opterror(opts,
1346 			    "osrelease string must be 1-%d bytes long",
1347 			    OSRELEASELEN - 1);
1348 			goto done_errmsg;
1349 		}
1350 	}
1351 
1352 	error = vfs_copyopt(opts, "osreldate", &osreldt, sizeof(osreldt));
1353 	if (error == ENOENT)
1354 		osreldt = 0;
1355 	else if (error != 0)
1356 		goto done_free;
1357 	else {
1358 		if (flags & JAIL_UPDATE) {
1359 			error = EINVAL;
1360 			vfs_opterror(opts,
1361 			    "osreldate cannot be changed after creation");
1362 			goto done_errmsg;
1363 		}
1364 		if (osreldt == 0) {
1365 			error = EINVAL;
1366 			vfs_opterror(opts, "osreldate cannot be 0");
1367 			goto done_errmsg;
1368 		}
1369 	}
1370 
1371 	root = NULL;
1372 	error = vfs_getopt(opts, "path", (void **)&path, &len);
1373 	if (error == ENOENT)
1374 		path = NULL;
1375 	else if (error != 0)
1376 		goto done_free;
1377 	else {
1378 		if (flags & JAIL_UPDATE) {
1379 			error = EINVAL;
1380 			vfs_opterror(opts,
1381 			    "path cannot be changed after creation");
1382 			goto done_errmsg;
1383 		}
1384 		if (len == 0 || path[len - 1] != '\0') {
1385 			error = EINVAL;
1386 			goto done_free;
1387 		}
1388 		NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path);
1389 		error = namei(&nd);
1390 		if (error)
1391 			goto done_free;
1392 		root = nd.ni_vp;
1393 		NDFREE_PNBUF(&nd);
1394 		g_path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
1395 		strlcpy(g_path, path, MAXPATHLEN);
1396 		error = vn_path_to_global_path(td, root, g_path, MAXPATHLEN);
1397 		if (error == 0) {
1398 			path = g_path;
1399 		} else {
1400 			/* exit on other errors */
1401 			goto done_free;
1402 		}
1403 		if (root->v_type != VDIR) {
1404 			error = ENOTDIR;
1405 			vput(root);
1406 			goto done_free;
1407 		}
1408 		VOP_UNLOCK(root);
1409 	}
1410 
1411 	/*
1412 	 * Find the specified jail, or at least its parent.
1413 	 * This abuses the file error codes ENOENT and EEXIST.
1414 	 */
1415 	pr = NULL;
1416 	inspr = NULL;
1417 	deadpr = NULL;
1418 	if (cuflags == JAIL_CREATE && jid == 0 && name != NULL) {
1419 		namelc = strrchr(name, '.');
1420 		jid = strtoul(namelc != NULL ? namelc + 1 : name, &p, 10);
1421 		if (*p != '\0')
1422 			jid = 0;
1423 	}
1424 	sx_xlock(&allprison_lock);
1425 	drflags = PD_LIST_XLOCKED;
1426 	ppr = mypr;
1427 	if (!prison_isalive(ppr)) {
1428 		/* This jail is dying.  This process will surely follow. */
1429 		error = EAGAIN;
1430 		goto done_deref;
1431 	}
1432 	if (jid != 0) {
1433 		if (jid < 0) {
1434 			error = EINVAL;
1435 			vfs_opterror(opts, "negative jid");
1436 			goto done_deref;
1437 		}
1438 		/*
1439 		 * See if a requested jid already exists.  Keep track of
1440 		 * where it can be inserted later.
1441 		 */
1442 		TAILQ_FOREACH(inspr, &allprison, pr_list) {
1443 			if (inspr->pr_id < jid)
1444 				continue;
1445 			if (inspr->pr_id > jid)
1446 				break;
1447 			if (prison_isalive(inspr)) {
1448 				pr = inspr;
1449 				mtx_lock(&pr->pr_mtx);
1450 				drflags |= PD_LOCKED;
1451 			} else {
1452 				/* Note a dying jail to handle later. */
1453 				deadpr = inspr;
1454 			}
1455 			inspr = NULL;
1456 			break;
1457 		}
1458 		if (cuflags == JAIL_CREATE && pr != NULL) {
1459 			/*
1460 			 * Even creators that cannot see the jail will
1461 			 * get EEXIST.
1462 			 */
1463 			error = EEXIST;
1464 			vfs_opterror(opts, "jail %d already exists", jid);
1465 			goto done_deref;
1466 		}
1467 		if ((pr == NULL)
1468 		    ? cuflags == JAIL_UPDATE
1469 		    : !prison_ischild(mypr, pr)) {
1470 			/*
1471 			 * Updaters get ENOENT for nonexistent jails,
1472 			 * or for jails they cannot see.  The latter
1473 			 * case is true even for CREATE | UPDATE,
1474 			 * which normally cannot give this error.
1475 			 */
1476 			error = ENOENT;
1477 			vfs_opterror(opts, "jail %d not found", jid);
1478 			goto done_deref;
1479 		}
1480 	}
1481 	/*
1482 	 * If the caller provided a name, look for a jail by that name.
1483 	 * This has different semantics for creates and updates keyed by jid
1484 	 * (where the name must not already exist in a different jail),
1485 	 * and updates keyed by the name itself (where the name must exist
1486 	 * because that is the jail being updated).
1487 	 */
1488 	namelc = NULL;
1489 	if (name != NULL) {
1490 		namelc = strrchr(name, '.');
1491 		if (namelc == NULL)
1492 			namelc = name;
1493 		else {
1494 			/*
1495 			 * This is a hierarchical name.  Split it into the
1496 			 * parent and child names, and make sure the parent
1497 			 * exists or matches an already found jail.
1498 			 */
1499 			if (pr != NULL) {
1500 				if (strncmp(name, ppr->pr_name, namelc - name)
1501 				    || ppr->pr_name[namelc - name] != '\0') {
1502 					error = EINVAL;
1503 					vfs_opterror(opts,
1504 					    "cannot change jail's parent");
1505 					goto done_deref;
1506 				}
1507 			} else {
1508 				*namelc = '\0';
1509 				ppr = prison_find_name(mypr, name);
1510 				if (ppr == NULL) {
1511 					error = ENOENT;
1512 					vfs_opterror(opts,
1513 					    "jail \"%s\" not found", name);
1514 					goto done_deref;
1515 				}
1516 				mtx_unlock(&ppr->pr_mtx);
1517 				if (!prison_isalive(ppr)) {
1518 					error = ENOENT;
1519 					vfs_opterror(opts,
1520 					    "jail \"%s\" is dying", name);
1521 					goto done_deref;
1522 				}
1523 				*namelc = '.';
1524 			}
1525 			namelc++;
1526 		}
1527 		if (namelc[0] != '\0') {
1528 			pnamelen =
1529 			    (ppr == &prison0) ? 0 : strlen(ppr->pr_name) + 1;
1530 			FOREACH_PRISON_CHILD(ppr, tpr) {
1531 				if (tpr == pr || !prison_isalive(tpr) ||
1532 				    strcmp(tpr->pr_name + pnamelen, namelc))
1533 					continue;
1534 				if (cuflags == JAIL_CREATE || pr != NULL) {
1535 					/*
1536 					 * Create, or update(jid): name must
1537 					 * not exist in an active sibling jail.
1538 					 */
1539 					error = EEXIST;
1540 					vfs_opterror(opts,
1541 					    "jail \"%s\" already exists", name);
1542 					goto done_deref;
1543 				}
1544 				/* Use this jail for updates. */
1545 				pr = tpr;
1546 				mtx_lock(&pr->pr_mtx);
1547 				drflags |= PD_LOCKED;
1548 				break;
1549 			}
1550 			/*
1551 			 * Update: name must exist if no jid is specified.
1552 			 * As with the jid case, the jail must be currently
1553 			 * visible, or else even CREATE | UPDATE will get
1554 			 * an error.
1555 			 */
1556 			if ((pr == NULL)
1557 			    ? cuflags == JAIL_UPDATE
1558 			    : !prison_isalive(pr)) {
1559 				error = ENOENT;
1560 				vfs_opterror(opts, "jail \"%s\" not found",
1561 				    name);
1562 				goto done_deref;
1563 			}
1564 		}
1565 	}
1566 	/* Update: must provide a jid or name. */
1567 	else if (cuflags == JAIL_UPDATE && pr == NULL) {
1568 		error = ENOENT;
1569 		vfs_opterror(opts, "update specified no jail");
1570 		goto done_deref;
1571 	}
1572 
1573 	/* If there's no prison to update, create a new one and link it in. */
1574 	created = pr == NULL;
1575 	if (created) {
1576 		for (tpr = mypr; tpr != NULL; tpr = tpr->pr_parent)
1577 			if (tpr->pr_childcount >= tpr->pr_childmax) {
1578 				error = EPERM;
1579 				vfs_opterror(opts, "prison limit exceeded");
1580 				goto done_deref;
1581 			}
1582 
1583 		if (deadpr != NULL) {
1584 			/*
1585 			 * The prison being created has the same ID as a dying
1586 			 * one.  Handle this by giving the dying jail a new ID.
1587 			 * This may cause some confusion to user space, but
1588 			 * only to those listing dying jails.
1589 			 */
1590 			deadid = get_next_deadid(&dinspr);
1591 			if (deadid == 0) {
1592 				error = EAGAIN;
1593 				vfs_opterror(opts, "no available jail IDs");
1594 				goto done_deref;
1595 			}
1596 			mtx_lock(&deadpr->pr_mtx);
1597 			deadpr->pr_id = deadid;
1598 			mtx_unlock(&deadpr->pr_mtx);
1599 			if (dinspr == deadpr)
1600 				inspr = deadpr;
1601 			else {
1602 				inspr = TAILQ_NEXT(deadpr, pr_list);
1603 				TAILQ_REMOVE(&allprison, deadpr, pr_list);
1604 				if (dinspr != NULL)
1605 					TAILQ_INSERT_AFTER(&allprison, dinspr,
1606 					    deadpr, pr_list);
1607 				else
1608 					TAILQ_INSERT_HEAD(&allprison, deadpr,
1609 					    pr_list);
1610 			}
1611 		}
1612 		if (jid == 0 && (jid = get_next_prid(&inspr)) == 0) {
1613 			error = EAGAIN;
1614 			vfs_opterror(opts, "no available jail IDs");
1615 			goto done_deref;
1616 		}
1617 
1618 		pr = malloc(sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO);
1619 		pr->pr_state = PRISON_STATE_INVALID;
1620 		refcount_init(&pr->pr_ref, 1);
1621 		refcount_init(&pr->pr_uref, 0);
1622 		drflags |= PD_DEREF;
1623 		LIST_INIT(&pr->pr_children);
1624 		mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF | MTX_DUPOK);
1625 		TASK_INIT(&pr->pr_task, 0, prison_complete, pr);
1626 
1627 		pr->pr_id = jid;
1628 		if (inspr != NULL)
1629 			TAILQ_INSERT_BEFORE(inspr, pr, pr_list);
1630 		else
1631 			TAILQ_INSERT_TAIL(&allprison, pr, pr_list);
1632 
1633 		pr->pr_parent = ppr;
1634 		prison_hold(ppr);
1635 		prison_proc_hold(ppr);
1636 		LIST_INSERT_HEAD(&ppr->pr_children, pr, pr_sibling);
1637 		for (tpr = ppr; tpr != NULL; tpr = tpr->pr_parent)
1638 			tpr->pr_childcount++;
1639 
1640 		/* Set some default values, and inherit some from the parent. */
1641 		if (namelc == NULL)
1642 			namelc = "";
1643 		if (path == NULL) {
1644 			path = "/";
1645 			root = mypr->pr_root;
1646 			vref(root);
1647 		}
1648 		strlcpy(pr->pr_hostuuid, DEFAULT_HOSTUUID, HOSTUUIDLEN);
1649 		pr->pr_flags |= PR_HOST;
1650 #if defined(INET) || defined(INET6)
1651 #ifdef VIMAGE
1652 		if (!(pr_flags & PR_VNET))
1653 #endif
1654 		{
1655 #ifdef INET
1656 			if (!(ch_flags & PR_IP4_USER))
1657 				pr->pr_flags |= PR_IP4 | PR_IP4_USER;
1658 			else if (!(pr_flags & PR_IP4_USER)) {
1659 				pr->pr_flags |= ppr->pr_flags & PR_IP4;
1660 				prison_ip_dup(ppr, pr, PR_INET);
1661 			}
1662 #endif
1663 #ifdef INET6
1664 			if (!(ch_flags & PR_IP6_USER))
1665 				pr->pr_flags |= PR_IP6 | PR_IP6_USER;
1666 			else if (!(pr_flags & PR_IP6_USER)) {
1667 				pr->pr_flags |= ppr->pr_flags & PR_IP6;
1668 				prison_ip_dup(ppr, pr, PR_INET6);
1669 			}
1670 #endif
1671 		}
1672 #endif
1673 		/* Source address selection is always on by default. */
1674 		pr->pr_flags |= _PR_IP_SADDRSEL;
1675 
1676 		pr->pr_securelevel = ppr->pr_securelevel;
1677 		pr->pr_allow = JAIL_DEFAULT_ALLOW & ppr->pr_allow;
1678 		pr->pr_enforce_statfs = jail_default_enforce_statfs;
1679 		pr->pr_devfs_rsnum = ppr->pr_devfs_rsnum;
1680 
1681 		pr->pr_osreldate = osreldt ? osreldt : ppr->pr_osreldate;
1682 		if (osrelstr == NULL)
1683 			strlcpy(pr->pr_osrelease, ppr->pr_osrelease,
1684 			    sizeof(pr->pr_osrelease));
1685 		else
1686 			strlcpy(pr->pr_osrelease, osrelstr,
1687 			    sizeof(pr->pr_osrelease));
1688 
1689 #ifdef VIMAGE
1690 		/*
1691 		 * Allocate a new vnet if specified.
1692 		 *
1693 		 * Set PR_VNET now if so, so that the vnet is disposed of
1694 		 * properly when the jail is destroyed.
1695 		 */
1696 		if (pr_flags & PR_VNET) {
1697 			pr->pr_flags |= PR_VNET;
1698 			pr->pr_vnet = vnet_alloc();
1699 		} else {
1700 			pr->pr_vnet = ppr->pr_vnet;
1701 		}
1702 #endif
1703 		/*
1704 		 * Allocate a dedicated cpuset for each jail.
1705 		 * Unlike other initial settings, this may return an error.
1706 		 */
1707 		error = cpuset_create_root(ppr, &pr->pr_cpuset);
1708 		if (error)
1709 			goto done_deref;
1710 
1711 		mtx_lock(&pr->pr_mtx);
1712 		drflags |= PD_LOCKED;
1713 	} else {
1714 		/*
1715 		 * Grab a reference for existing prisons, to ensure they
1716 		 * continue to exist for the duration of the call.
1717 		 */
1718 		prison_hold(pr);
1719 		drflags |= PD_DEREF;
1720 #if defined(VIMAGE) && (defined(INET) || defined(INET6))
1721 		if ((pr->pr_flags & PR_VNET) &&
1722 		    (ch_flags & (PR_IP4_USER | PR_IP6_USER))) {
1723 			error = EINVAL;
1724 			vfs_opterror(opts,
1725 			    "vnet jails cannot have IP address restrictions");
1726 			goto done_deref;
1727 		}
1728 #endif
1729 #ifdef INET
1730 		if (PR_IP4_USER & ch_flags & (pr_flags ^ pr->pr_flags)) {
1731 			error = EINVAL;
1732 			vfs_opterror(opts,
1733 			    "ip4 cannot be changed after creation");
1734 			goto done_deref;
1735 		}
1736 #endif
1737 #ifdef INET6
1738 		if (PR_IP6_USER & ch_flags & (pr_flags ^ pr->pr_flags)) {
1739 			error = EINVAL;
1740 			vfs_opterror(opts,
1741 			    "ip6 cannot be changed after creation");
1742 			goto done_deref;
1743 		}
1744 #endif
1745 	}
1746 
1747 	/* Do final error checking before setting anything. */
1748 	if (gotslevel) {
1749 		if (slevel < ppr->pr_securelevel) {
1750 			error = EPERM;
1751 			goto done_deref;
1752 		}
1753 	}
1754 	if (gotchildmax) {
1755 		if (childmax >= ppr->pr_childmax) {
1756 			error = EPERM;
1757 			goto done_deref;
1758 		}
1759 	}
1760 	if (gotenforce) {
1761 		if (enforce < ppr->pr_enforce_statfs) {
1762 			error = EPERM;
1763 			goto done_deref;
1764 		}
1765 	}
1766 	if (gotrsnum) {
1767 		/*
1768 		 * devfs_rsnum is a uint16_t
1769 		 */
1770 		if (rsnum < 0 || rsnum > 65535) {
1771 			error = EINVAL;
1772 			goto done_deref;
1773 		}
1774 		/*
1775 		 * Nested jails always inherit parent's devfs ruleset
1776 		 */
1777 		if (jailed(td->td_ucred)) {
1778 			if (rsnum > 0 && rsnum != ppr->pr_devfs_rsnum) {
1779 				error = EPERM;
1780 				goto done_deref;
1781 			} else
1782 				rsnum = ppr->pr_devfs_rsnum;
1783 		}
1784 	}
1785 #ifdef INET
1786 	if (ip4s > 0) {
1787 		if ((ppr->pr_flags & PR_IP4) &&
1788 		    !prison_ip_parent_match(ppr->pr_addrs[PR_INET], ip4,
1789 		    PR_INET)) {
1790 			error = EPERM;
1791 			goto done_deref;
1792 		}
1793 		if (!prison_ip_conflict_check(ppr, pr, ip4, PR_INET)) {
1794 			error = EADDRINUSE;
1795 			vfs_opterror(opts, "IPv4 addresses clash");
1796 			goto done_deref;
1797 		}
1798 	}
1799 #endif
1800 #ifdef INET6
1801 	if (ip6s > 0) {
1802 		if ((ppr->pr_flags & PR_IP6) &&
1803 		    !prison_ip_parent_match(ppr->pr_addrs[PR_INET6], ip6,
1804 		    PR_INET6)) {
1805 			error = EPERM;
1806 			goto done_deref;
1807 		}
1808 		if (!prison_ip_conflict_check(ppr, pr, ip6, PR_INET6)) {
1809 			error = EADDRINUSE;
1810 			vfs_opterror(opts, "IPv6 addresses clash");
1811 			goto done_deref;
1812 		}
1813 	}
1814 #endif
1815 	onamelen = namelen = 0;
1816 	if (namelc != NULL) {
1817 		/* Give a default name of the jid.  Also allow the name to be
1818 		 * explicitly the jid - but not any other number, and only in
1819 		 * normal form (no leading zero/etc).
1820 		 */
1821 		if (namelc[0] == '\0')
1822 			snprintf(namelc = numbuf, sizeof(numbuf), "%d", jid);
1823 		else if ((strtoul(namelc, &p, 10) != jid ||
1824 			  namelc[0] < '1' || namelc[0] > '9') && *p == '\0') {
1825 			error = EINVAL;
1826 			vfs_opterror(opts,
1827 			    "name cannot be numeric (unless it is the jid)");
1828 			goto done_deref;
1829 		}
1830 		/*
1831 		 * Make sure the name isn't too long for the prison or its
1832 		 * children.
1833 		 */
1834 		pnamelen = (ppr == &prison0) ? 0 : strlen(ppr->pr_name) + 1;
1835 		onamelen = strlen(pr->pr_name + pnamelen);
1836 		namelen = strlen(namelc);
1837 		if (pnamelen + namelen + 1 > sizeof(pr->pr_name)) {
1838 			error = ENAMETOOLONG;
1839 			goto done_deref;
1840 		}
1841 		FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1842 			if (strlen(tpr->pr_name) + (namelen - onamelen) >=
1843 			    sizeof(pr->pr_name)) {
1844 				error = ENAMETOOLONG;
1845 				goto done_deref;
1846 			}
1847 		}
1848 	}
1849 	pr_allow_diff = pr_allow & ~ppr->pr_allow;
1850 	if (pr_allow_diff & ~PR_ALLOW_DIFFERENCES) {
1851 		error = EPERM;
1852 		goto done_deref;
1853 	}
1854 
1855 	/*
1856 	 * Let modules check their parameters.  This requires unlocking and
1857 	 * then re-locking the prison, but this is still a valid state as long
1858 	 * as allprison_lock remains xlocked.
1859 	 */
1860 	mtx_unlock(&pr->pr_mtx);
1861 	drflags &= ~PD_LOCKED;
1862 	error = osd_jail_call(pr, PR_METHOD_CHECK, opts);
1863 	if (error != 0)
1864 		goto done_deref;
1865 	mtx_lock(&pr->pr_mtx);
1866 	drflags |= PD_LOCKED;
1867 
1868 	/* At this point, all valid parameters should have been noted. */
1869 	TAILQ_FOREACH(opt, opts, link) {
1870 		if (!opt->seen && strcmp(opt->name, "errmsg")) {
1871 			error = EINVAL;
1872 			vfs_opterror(opts, "unknown parameter: %s", opt->name);
1873 			goto done_deref;
1874 		}
1875 	}
1876 
1877 	/* Set the parameters of the prison. */
1878 #ifdef INET
1879 	redo_ip4 = false;
1880 	if (pr_flags & PR_IP4_USER) {
1881 		pr->pr_flags |= PR_IP4;
1882 		prison_ip_set(pr, PR_INET, ip4);
1883 		ip4 = NULL;
1884 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1885 #ifdef VIMAGE
1886 			if (tpr->pr_flags & PR_VNET) {
1887 				descend = 0;
1888 				continue;
1889 			}
1890 #endif
1891 			if (!prison_ip_restrict(tpr, PR_INET, NULL)) {
1892 				redo_ip4 = true;
1893 				descend = 0;
1894 			}
1895 		}
1896 	}
1897 #endif
1898 #ifdef INET6
1899 	redo_ip6 = false;
1900 	if (pr_flags & PR_IP6_USER) {
1901 		pr->pr_flags |= PR_IP6;
1902 		prison_ip_set(pr, PR_INET6, ip6);
1903 		ip6 = NULL;
1904 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1905 #ifdef VIMAGE
1906 			if (tpr->pr_flags & PR_VNET) {
1907 				descend = 0;
1908 				continue;
1909 			}
1910 #endif
1911 			if (!prison_ip_restrict(tpr, PR_INET6, NULL)) {
1912 				redo_ip6 = true;
1913 				descend = 0;
1914 			}
1915 		}
1916 	}
1917 #endif
1918 	if (gotslevel) {
1919 		pr->pr_securelevel = slevel;
1920 		/* Set all child jails to be at least this level. */
1921 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1922 			if (tpr->pr_securelevel < slevel)
1923 				tpr->pr_securelevel = slevel;
1924 	}
1925 	if (gotchildmax) {
1926 		pr->pr_childmax = childmax;
1927 		/* Set all child jails to under this limit. */
1928 		FOREACH_PRISON_DESCENDANT_LOCKED_LEVEL(pr, tpr, descend, level)
1929 			if (tpr->pr_childmax > childmax - level)
1930 				tpr->pr_childmax = childmax > level
1931 				    ? childmax - level : 0;
1932 	}
1933 	if (gotenforce) {
1934 		pr->pr_enforce_statfs = enforce;
1935 		/* Pass this restriction on to the children. */
1936 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1937 			if (tpr->pr_enforce_statfs < enforce)
1938 				tpr->pr_enforce_statfs = enforce;
1939 	}
1940 	if (gotrsnum) {
1941 		pr->pr_devfs_rsnum = rsnum;
1942 		/* Pass this restriction on to the children. */
1943 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend)
1944 			tpr->pr_devfs_rsnum = rsnum;
1945 	}
1946 	if (namelc != NULL) {
1947 		if (ppr == &prison0)
1948 			strlcpy(pr->pr_name, namelc, sizeof(pr->pr_name));
1949 		else
1950 			snprintf(pr->pr_name, sizeof(pr->pr_name), "%s.%s",
1951 			    ppr->pr_name, namelc);
1952 		/* Change this component of child names. */
1953 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1954 			bcopy(tpr->pr_name + onamelen, tpr->pr_name + namelen,
1955 			    strlen(tpr->pr_name + onamelen) + 1);
1956 			bcopy(pr->pr_name, tpr->pr_name, namelen);
1957 		}
1958 	}
1959 	if (path != NULL) {
1960 		/* Try to keep a real-rooted full pathname. */
1961 		strlcpy(pr->pr_path, path, sizeof(pr->pr_path));
1962 		pr->pr_root = root;
1963 		root = NULL;
1964 	}
1965 	if (PR_HOST & ch_flags & ~pr_flags) {
1966 		if (pr->pr_flags & PR_HOST) {
1967 			/*
1968 			 * Copy the parent's host info.  As with pr_ip4 above,
1969 			 * the lack of a lock on the parent is not a problem;
1970 			 * it is always set with allprison_lock at least
1971 			 * shared, and is held exclusively here.
1972 			 */
1973 			strlcpy(pr->pr_hostname, pr->pr_parent->pr_hostname,
1974 			    sizeof(pr->pr_hostname));
1975 			strlcpy(pr->pr_domainname, pr->pr_parent->pr_domainname,
1976 			    sizeof(pr->pr_domainname));
1977 			strlcpy(pr->pr_hostuuid, pr->pr_parent->pr_hostuuid,
1978 			    sizeof(pr->pr_hostuuid));
1979 			pr->pr_hostid = pr->pr_parent->pr_hostid;
1980 		}
1981 	} else if (host != NULL || domain != NULL || uuid != NULL || gothid) {
1982 		/* Set this prison, and any descendants without PR_HOST. */
1983 		if (host != NULL)
1984 			strlcpy(pr->pr_hostname, host, sizeof(pr->pr_hostname));
1985 		if (domain != NULL)
1986 			strlcpy(pr->pr_domainname, domain,
1987 			    sizeof(pr->pr_domainname));
1988 		if (uuid != NULL)
1989 			strlcpy(pr->pr_hostuuid, uuid, sizeof(pr->pr_hostuuid));
1990 		if (gothid)
1991 			pr->pr_hostid = hid;
1992 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
1993 			if (tpr->pr_flags & PR_HOST)
1994 				descend = 0;
1995 			else {
1996 				if (host != NULL)
1997 					strlcpy(tpr->pr_hostname,
1998 					    pr->pr_hostname,
1999 					    sizeof(tpr->pr_hostname));
2000 				if (domain != NULL)
2001 					strlcpy(tpr->pr_domainname,
2002 					    pr->pr_domainname,
2003 					    sizeof(tpr->pr_domainname));
2004 				if (uuid != NULL)
2005 					strlcpy(tpr->pr_hostuuid,
2006 					    pr->pr_hostuuid,
2007 					    sizeof(tpr->pr_hostuuid));
2008 				if (gothid)
2009 					tpr->pr_hostid = hid;
2010 			}
2011 		}
2012 	}
2013 	pr->pr_allow = (pr->pr_allow & ~ch_allow) | pr_allow;
2014 	if ((tallow = ch_allow & ~pr_allow))
2015 		prison_set_allow_locked(pr, tallow, 0);
2016 	/*
2017 	 * Persistent prisons get an extra reference, and prisons losing their
2018 	 * persist flag lose that reference.
2019 	 */
2020 	if (ch_flags & PR_PERSIST & (pr_flags ^ pr->pr_flags)) {
2021 		if (pr_flags & PR_PERSIST) {
2022 			prison_hold(pr);
2023 			/*
2024 			 * This may be a new prison's first user reference,
2025 			 * but wait to call it alive until after OSD calls
2026 			 * have had a chance to run (and perhaps to fail).
2027 			 */
2028 			refcount_acquire(&pr->pr_uref);
2029 		} else {
2030 			drflags |= PD_DEUREF;
2031 			prison_free_not_last(pr);
2032 		}
2033 	}
2034 	pr->pr_flags = (pr->pr_flags & ~ch_flags) | pr_flags;
2035 	mtx_unlock(&pr->pr_mtx);
2036 	drflags &= ~PD_LOCKED;
2037 	/*
2038 	 * Any errors past this point will need to de-persist newly created
2039 	 * prisons, as well as call remove methods.
2040 	 */
2041 	if (created)
2042 		drflags |= PD_KILL;
2043 
2044 #ifdef RACCT
2045 	if (racct_enable && created)
2046 		prison_racct_attach(pr);
2047 #endif
2048 
2049 	/* Locks may have prevented a complete restriction of child IP
2050 	 * addresses.  If so, allocate some more memory and try again.
2051 	 */
2052 #ifdef INET
2053 	while (redo_ip4) {
2054 		ip4s = pr->pr_addrs[PR_INET]->ips;
2055 		MPASS(ip4 == NULL);
2056 		ip4 = prison_ip_alloc(PR_INET, ip4s, M_WAITOK);
2057 		mtx_lock(&pr->pr_mtx);
2058 		redo_ip4 = false;
2059 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
2060 #ifdef VIMAGE
2061 			if (tpr->pr_flags & PR_VNET) {
2062 				descend = 0;
2063 				continue;
2064 			}
2065 #endif
2066 			if (!prison_ip_restrict(tpr, PR_INET, &ip4))
2067 				redo_ip4 = true;
2068 		}
2069 		mtx_unlock(&pr->pr_mtx);
2070 	}
2071 #endif
2072 #ifdef INET6
2073 	while (redo_ip6) {
2074 		ip6s = pr->pr_addrs[PR_INET6]->ips;
2075 		MPASS(ip6 == NULL);
2076 		ip6 = prison_ip_alloc(PR_INET6, ip6s, M_WAITOK);
2077 		mtx_lock(&pr->pr_mtx);
2078 		redo_ip6 = false;
2079 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, tpr, descend) {
2080 #ifdef VIMAGE
2081 			if (tpr->pr_flags & PR_VNET) {
2082 				descend = 0;
2083 				continue;
2084 			}
2085 #endif
2086 			if (!prison_ip_restrict(tpr, PR_INET6, &ip6))
2087 				redo_ip6 = true;
2088 		}
2089 		mtx_unlock(&pr->pr_mtx);
2090 	}
2091 #endif
2092 
2093 	/* Let the modules do their work. */
2094 	if (created) {
2095 		error = osd_jail_call(pr, PR_METHOD_CREATE, opts);
2096 		if (error)
2097 			goto done_deref;
2098 	}
2099 	error = osd_jail_call(pr, PR_METHOD_SET, opts);
2100 	if (error)
2101 		goto done_deref;
2102 
2103 	/*
2104 	 * A new prison is now ready to be seen; either it has gained a user
2105 	 * reference via persistence, or is about to gain one via attachment.
2106 	 */
2107 	if (created) {
2108 		drflags = prison_lock_xlock(pr, drflags);
2109 		pr->pr_state = PRISON_STATE_ALIVE;
2110 	}
2111 
2112 	/* Attach this process to the prison if requested. */
2113 	if (flags & JAIL_ATTACH) {
2114 		error = do_jail_attach(td, pr,
2115 		    prison_lock_xlock(pr, drflags & PD_LOCK_FLAGS));
2116 		drflags &= ~(PD_LOCKED | PD_LIST_XLOCKED);
2117 		if (error) {
2118 			vfs_opterror(opts, "attach failed");
2119 			goto done_deref;
2120 		}
2121 	}
2122 
2123 #ifdef RACCT
2124 	if (racct_enable && !created) {
2125 		if (drflags & PD_LOCKED) {
2126 			mtx_unlock(&pr->pr_mtx);
2127 			drflags &= ~PD_LOCKED;
2128 		}
2129 		if (drflags & PD_LIST_XLOCKED) {
2130 			sx_xunlock(&allprison_lock);
2131 			drflags &= ~PD_LIST_XLOCKED;
2132 		}
2133 		prison_racct_modify(pr);
2134 	}
2135 #endif
2136 
2137 	if (created && pr != &prison0 && (pr->pr_allow & PR_ALLOW_NFSD) != 0 &&
2138 	    (pr->pr_root->v_vflag & VV_ROOT) == 0)
2139 		printf("Warning jail jid=%d: mountd/nfsd requires a separate"
2140 		   " file system\n", pr->pr_id);
2141 
2142 	drflags &= ~PD_KILL;
2143 	td->td_retval[0] = pr->pr_id;
2144 
2145  done_deref:
2146 	/* Release any temporary prison holds and/or locks. */
2147 	if (pr != NULL)
2148 		prison_deref(pr, drflags);
2149 	else if (drflags & PD_LIST_SLOCKED)
2150 		sx_sunlock(&allprison_lock);
2151 	else if (drflags & PD_LIST_XLOCKED)
2152 		sx_xunlock(&allprison_lock);
2153 	if (root != NULL)
2154 		vrele(root);
2155  done_errmsg:
2156 	if (error) {
2157 		/* Write the error message back to userspace. */
2158 		if (vfs_getopt(opts, "errmsg", (void **)&errmsg,
2159 		    &errmsg_len) == 0 && errmsg_len > 0) {
2160 			errmsg_pos = 2 * vfs_getopt_pos(opts, "errmsg") + 1;
2161 			if (optuio->uio_segflg == UIO_SYSSPACE)
2162 				bcopy(errmsg,
2163 				    optuio->uio_iov[errmsg_pos].iov_base,
2164 				    errmsg_len);
2165 			else
2166 				(void)copyout(errmsg,
2167 				    optuio->uio_iov[errmsg_pos].iov_base,
2168 				    errmsg_len);
2169 		}
2170 	}
2171  done_free:
2172 #ifdef INET
2173 	prison_ip_free(ip4);
2174 #endif
2175 #ifdef INET6
2176 	prison_ip_free(ip6);
2177 #endif
2178 	if (g_path != NULL)
2179 		free(g_path, M_TEMP);
2180 	vfs_freeopts(opts);
2181 	return (error);
2182 }
2183 
2184 /*
2185  * Find the next available prison ID.  Return the ID on success, or zero
2186  * on failure.  Also set a pointer to the allprison list entry the prison
2187  * should be inserted before.
2188  */
2189 static int
get_next_prid(struct prison ** insprp)2190 get_next_prid(struct prison **insprp)
2191 {
2192 	struct prison *inspr;
2193 	int jid, maxid;
2194 
2195 	jid = lastprid % JAIL_MAX + 1;
2196 	if (TAILQ_EMPTY(&allprison) ||
2197 	    TAILQ_LAST(&allprison, prisonlist)->pr_id < jid) {
2198 		/*
2199 		 * A common case is for all jails to be implicitly numbered,
2200 		 * which means they'll go on the end of the list, at least
2201 		 * for the first JAIL_MAX times.
2202 		 */
2203 		inspr = NULL;
2204 	} else {
2205 		/*
2206 		 * Take two passes through the allprison list: first starting
2207 		 * with the proposed jid, then ending with it.
2208 		 */
2209 		for (maxid = JAIL_MAX; maxid != 0; ) {
2210 			TAILQ_FOREACH(inspr, &allprison, pr_list) {
2211 				if (inspr->pr_id < jid)
2212 					continue;
2213 				if (inspr->pr_id > jid) {
2214 					/* Found an opening. */
2215 					maxid = 0;
2216 					break;
2217 				}
2218 				if (++jid > maxid) {
2219 					if (lastprid == maxid || lastprid == 0)
2220 					{
2221 						/*
2222 						 * The entire legal range
2223 						 * has been traversed
2224 						 */
2225 						return 0;
2226 					}
2227 					/* Try again from the start. */
2228 					jid = 1;
2229 					maxid = lastprid;
2230 					break;
2231 				}
2232 			}
2233 			if (inspr == NULL) {
2234 				/* Found room at the end of the list. */
2235 				break;
2236 			}
2237 		}
2238 	}
2239 	*insprp = inspr;
2240 	lastprid = jid;
2241 	return (jid);
2242 }
2243 
2244 /*
2245  * Find the next available ID for a renumbered dead prison.  This is the same
2246  * as get_next_prid, but counting backward from the end of the range.
2247  */
2248 static int
get_next_deadid(struct prison ** dinsprp)2249 get_next_deadid(struct prison **dinsprp)
2250 {
2251 	struct prison *dinspr;
2252 	int deadid, minid;
2253 
2254 	deadid = lastdeadid ? lastdeadid - 1 : JAIL_MAX;
2255 	/*
2256 	 * Take two reverse passes through the allprison list: first
2257 	 * starting with the proposed deadid, then ending with it.
2258 	 */
2259 	for (minid = 1; minid != 0; ) {
2260 		TAILQ_FOREACH_REVERSE(dinspr, &allprison, prisonlist, pr_list) {
2261 			if (dinspr->pr_id > deadid)
2262 				continue;
2263 			if (dinspr->pr_id < deadid) {
2264 				/* Found an opening. */
2265 				minid = 0;
2266 				break;
2267 			}
2268 			if (--deadid < minid) {
2269 				if (lastdeadid == minid || lastdeadid == 0)
2270 				{
2271 					/*
2272 					 * The entire legal range
2273 					 * has been traversed
2274 					 */
2275 					return 0;
2276 				}
2277 				/* Try again from the end. */
2278 				deadid = JAIL_MAX;
2279 				minid = lastdeadid;
2280 				break;
2281 			}
2282 		}
2283 		if (dinspr == NULL) {
2284 			/* Found room at the beginning of the list. */
2285 			break;
2286 		}
2287 	}
2288 	*dinsprp = dinspr;
2289 	lastdeadid = deadid;
2290 	return (deadid);
2291 }
2292 
2293 /*
2294  * struct jail_get_args {
2295  *	struct iovec *iovp;
2296  *	unsigned int iovcnt;
2297  *	int flags;
2298  * };
2299  */
2300 int
sys_jail_get(struct thread * td,struct jail_get_args * uap)2301 sys_jail_get(struct thread *td, struct jail_get_args *uap)
2302 {
2303 	struct uio *auio;
2304 	int error;
2305 
2306 	/* Check that we have an even number of iovecs. */
2307 	if (uap->iovcnt & 1)
2308 		return (EINVAL);
2309 
2310 	error = copyinuio(uap->iovp, uap->iovcnt, &auio);
2311 	if (error)
2312 		return (error);
2313 	error = kern_jail_get(td, auio, uap->flags);
2314 	if (error == 0)
2315 		error = copyout(auio->uio_iov, uap->iovp,
2316 		    uap->iovcnt * sizeof(struct iovec));
2317 	freeuio(auio);
2318 	return (error);
2319 }
2320 
2321 int
kern_jail_get(struct thread * td,struct uio * optuio,int flags)2322 kern_jail_get(struct thread *td, struct uio *optuio, int flags)
2323 {
2324 	struct bool_flags *bf;
2325 	struct jailsys_flags *jsf;
2326 	struct prison *pr, *mypr;
2327 	struct vfsopt *opt;
2328 	struct vfsoptlist *opts;
2329 	char *errmsg, *name;
2330 	int drflags, error, errmsg_len, errmsg_pos, i, jid, len, pos;
2331 	unsigned f;
2332 
2333 	if (flags & ~JAIL_GET_MASK)
2334 		return (EINVAL);
2335 
2336 	/* Get the parameter list. */
2337 	error = vfs_buildopts(optuio, &opts);
2338 	if (error)
2339 		return (error);
2340 	errmsg_pos = vfs_getopt_pos(opts, "errmsg");
2341 	mypr = td->td_ucred->cr_prison;
2342 	pr = NULL;
2343 
2344 	/*
2345 	 * Find the prison specified by one of: lastjid, jid, name.
2346 	 */
2347 	sx_slock(&allprison_lock);
2348 	drflags = PD_LIST_SLOCKED;
2349 	error = vfs_copyopt(opts, "lastjid", &jid, sizeof(jid));
2350 	if (error == 0) {
2351 		TAILQ_FOREACH(pr, &allprison, pr_list) {
2352 			if (pr->pr_id > jid &&
2353 			    ((flags & JAIL_DYING) || prison_isalive(pr)) &&
2354 			    prison_ischild(mypr, pr)) {
2355 				mtx_lock(&pr->pr_mtx);
2356 				drflags |= PD_LOCKED;
2357 				goto found_prison;
2358 			}
2359 		}
2360 		error = ENOENT;
2361 		vfs_opterror(opts, "no jail after %d", jid);
2362 		goto done;
2363 	} else if (error != ENOENT)
2364 		goto done;
2365 
2366 	error = vfs_copyopt(opts, "jid", &jid, sizeof(jid));
2367 	if (error == 0) {
2368 		if (jid != 0) {
2369 			pr = prison_find_child(mypr, jid);
2370 			if (pr != NULL) {
2371 				drflags |= PD_LOCKED;
2372 				if (!(prison_isalive(pr) ||
2373 				    (flags & JAIL_DYING))) {
2374 					error = ENOENT;
2375 					vfs_opterror(opts, "jail %d is dying",
2376 					    jid);
2377 					goto done;
2378 				}
2379 				goto found_prison;
2380 			}
2381 			error = ENOENT;
2382 			vfs_opterror(opts, "jail %d not found", jid);
2383 			goto done;
2384 		}
2385 	} else if (error != ENOENT)
2386 		goto done;
2387 
2388 	error = vfs_getopt(opts, "name", (void **)&name, &len);
2389 	if (error == 0) {
2390 		if (len == 0 || name[len - 1] != '\0') {
2391 			error = EINVAL;
2392 			goto done;
2393 		}
2394 		pr = prison_find_name(mypr, name);
2395 		if (pr != NULL) {
2396 			drflags |= PD_LOCKED;
2397 			if (!(prison_isalive(pr) || (flags & JAIL_DYING))) {
2398 				error = ENOENT;
2399 				vfs_opterror(opts, "jail \"%s\" is dying",
2400 				    name);
2401 				goto done;
2402 			}
2403 			goto found_prison;
2404 		}
2405 		error = ENOENT;
2406 		vfs_opterror(opts, "jail \"%s\" not found", name);
2407 		goto done;
2408 	} else if (error != ENOENT)
2409 		goto done;
2410 
2411 	vfs_opterror(opts, "no jail specified");
2412 	error = ENOENT;
2413 	goto done;
2414 
2415  found_prison:
2416 	/* Get the parameters of the prison. */
2417 	prison_hold(pr);
2418 	drflags |= PD_DEREF;
2419 	td->td_retval[0] = pr->pr_id;
2420 	error = vfs_setopt(opts, "jid", &pr->pr_id, sizeof(pr->pr_id));
2421 	if (error != 0 && error != ENOENT)
2422 		goto done;
2423 	i = (pr->pr_parent == mypr) ? 0 : pr->pr_parent->pr_id;
2424 	error = vfs_setopt(opts, "parent", &i, sizeof(i));
2425 	if (error != 0 && error != ENOENT)
2426 		goto done;
2427 	error = vfs_setopts(opts, "name", prison_name(mypr, pr));
2428 	if (error != 0 && error != ENOENT)
2429 		goto done;
2430 	error = vfs_setopt(opts, "cpuset.id", &pr->pr_cpuset->cs_id,
2431 	    sizeof(pr->pr_cpuset->cs_id));
2432 	if (error != 0 && error != ENOENT)
2433 		goto done;
2434 	error = vfs_setopts(opts, "path", prison_path(mypr, pr));
2435 	if (error != 0 && error != ENOENT)
2436 		goto done;
2437 #ifdef INET
2438 	error = vfs_setopt_part(opts, "ip4.addr", pr->pr_addrs[PR_INET]->pr_ip,
2439 	    pr->pr_addrs[PR_INET] ? pr->pr_addrs[PR_INET]->ips *
2440 	    pr_families[PR_INET].size : 0 );
2441 	if (error != 0 && error != ENOENT)
2442 		goto done;
2443 #endif
2444 #ifdef INET6
2445 	error = vfs_setopt_part(opts, "ip6.addr", pr->pr_addrs[PR_INET6]->pr_ip,
2446 	    pr->pr_addrs[PR_INET6] ? pr->pr_addrs[PR_INET6]->ips *
2447 	    pr_families[PR_INET6].size : 0 );
2448 	if (error != 0 && error != ENOENT)
2449 		goto done;
2450 #endif
2451 	error = vfs_setopt(opts, "securelevel", &pr->pr_securelevel,
2452 	    sizeof(pr->pr_securelevel));
2453 	if (error != 0 && error != ENOENT)
2454 		goto done;
2455 	error = vfs_setopt(opts, "children.cur", &pr->pr_childcount,
2456 	    sizeof(pr->pr_childcount));
2457 	if (error != 0 && error != ENOENT)
2458 		goto done;
2459 	error = vfs_setopt(opts, "children.max", &pr->pr_childmax,
2460 	    sizeof(pr->pr_childmax));
2461 	if (error != 0 && error != ENOENT)
2462 		goto done;
2463 	error = vfs_setopts(opts, "host.hostname", pr->pr_hostname);
2464 	if (error != 0 && error != ENOENT)
2465 		goto done;
2466 	error = vfs_setopts(opts, "host.domainname", pr->pr_domainname);
2467 	if (error != 0 && error != ENOENT)
2468 		goto done;
2469 	error = vfs_setopts(opts, "host.hostuuid", pr->pr_hostuuid);
2470 	if (error != 0 && error != ENOENT)
2471 		goto done;
2472 #ifdef COMPAT_FREEBSD32
2473 	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
2474 		uint32_t hid32 = pr->pr_hostid;
2475 
2476 		error = vfs_setopt(opts, "host.hostid", &hid32, sizeof(hid32));
2477 	} else
2478 #endif
2479 	error = vfs_setopt(opts, "host.hostid", &pr->pr_hostid,
2480 	    sizeof(pr->pr_hostid));
2481 	if (error != 0 && error != ENOENT)
2482 		goto done;
2483 	error = vfs_setopt(opts, "enforce_statfs", &pr->pr_enforce_statfs,
2484 	    sizeof(pr->pr_enforce_statfs));
2485 	if (error != 0 && error != ENOENT)
2486 		goto done;
2487 	error = vfs_setopt(opts, "devfs_ruleset", &pr->pr_devfs_rsnum,
2488 	    sizeof(pr->pr_devfs_rsnum));
2489 	if (error != 0 && error != ENOENT)
2490 		goto done;
2491 	for (bf = pr_flag_bool;
2492 	     bf < pr_flag_bool + nitems(pr_flag_bool);
2493 	     bf++) {
2494 		i = (pr->pr_flags & bf->flag) ? 1 : 0;
2495 		error = vfs_setopt(opts, bf->name, &i, sizeof(i));
2496 		if (error != 0 && error != ENOENT)
2497 			goto done;
2498 		i = !i;
2499 		error = vfs_setopt(opts, bf->noname, &i, sizeof(i));
2500 		if (error != 0 && error != ENOENT)
2501 			goto done;
2502 	}
2503 	for (jsf = pr_flag_jailsys;
2504 	     jsf < pr_flag_jailsys + nitems(pr_flag_jailsys);
2505 	     jsf++) {
2506 		f = pr->pr_flags & (jsf->disable | jsf->new);
2507 		i = (f != 0 && f == jsf->disable) ? JAIL_SYS_DISABLE
2508 		    : (f == jsf->new) ? JAIL_SYS_NEW
2509 		    : JAIL_SYS_INHERIT;
2510 		error = vfs_setopt(opts, jsf->name, &i, sizeof(i));
2511 		if (error != 0 && error != ENOENT)
2512 			goto done;
2513 	}
2514 	for (bf = pr_flag_allow;
2515 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
2516 		atomic_load_int(&bf->flag) != 0;
2517 	     bf++) {
2518 		i = (pr->pr_allow & bf->flag) ? 1 : 0;
2519 		error = vfs_setopt(opts, bf->name, &i, sizeof(i));
2520 		if (error != 0 && error != ENOENT)
2521 			goto done;
2522 		i = !i;
2523 		error = vfs_setopt(opts, bf->noname, &i, sizeof(i));
2524 		if (error != 0 && error != ENOENT)
2525 			goto done;
2526 	}
2527 	i = !prison_isalive(pr);
2528 	error = vfs_setopt(opts, "dying", &i, sizeof(i));
2529 	if (error != 0 && error != ENOENT)
2530 		goto done;
2531 	i = !i;
2532 	error = vfs_setopt(opts, "nodying", &i, sizeof(i));
2533 	if (error != 0 && error != ENOENT)
2534 		goto done;
2535 	error = vfs_setopt(opts, "osreldate", &pr->pr_osreldate,
2536 	    sizeof(pr->pr_osreldate));
2537 	if (error != 0 && error != ENOENT)
2538 		goto done;
2539 	error = vfs_setopts(opts, "osrelease", pr->pr_osrelease);
2540 	if (error != 0 && error != ENOENT)
2541 		goto done;
2542 
2543 	/* Get the module parameters. */
2544 	mtx_unlock(&pr->pr_mtx);
2545 	drflags &= ~PD_LOCKED;
2546 	error = osd_jail_call(pr, PR_METHOD_GET, opts);
2547 	if (error)
2548 		goto done;
2549 	prison_deref(pr, drflags);
2550 	pr = NULL;
2551 	drflags = 0;
2552 
2553 	/* By now, all parameters should have been noted. */
2554 	TAILQ_FOREACH(opt, opts, link) {
2555 		if (!opt->seen &&
2556 		    (strstr(opt->name, JAIL_META_PRIVATE ".") == opt->name ||
2557 		    strstr(opt->name, JAIL_META_SHARED ".") == opt->name)) {
2558 			/* Communicate back a missing key. */
2559 			free(opt->value, M_MOUNT);
2560 			opt->value = NULL;
2561 			opt->len = 0;
2562 			continue;
2563 		}
2564 		if (!opt->seen && strcmp(opt->name, "errmsg")) {
2565 			error = EINVAL;
2566 			vfs_opterror(opts, "unknown parameter: %s", opt->name);
2567 			goto done;
2568 		}
2569 	}
2570 
2571 	/* Write the fetched parameters back to userspace. */
2572 	error = 0;
2573 	TAILQ_FOREACH(opt, opts, link) {
2574 		if (opt->pos >= 0 && opt->pos != errmsg_pos) {
2575 			pos = 2 * opt->pos + 1;
2576 			optuio->uio_iov[pos].iov_len = opt->len;
2577 			if (opt->value != NULL) {
2578 				if (optuio->uio_segflg == UIO_SYSSPACE) {
2579 					bcopy(opt->value,
2580 					    optuio->uio_iov[pos].iov_base,
2581 					    opt->len);
2582 				} else {
2583 					error = copyout(opt->value,
2584 					    optuio->uio_iov[pos].iov_base,
2585 					    opt->len);
2586 					if (error)
2587 						break;
2588 				}
2589 			}
2590 		}
2591 	}
2592 
2593  done:
2594 	/* Release any temporary prison holds and/or locks. */
2595 	if (pr != NULL)
2596 		prison_deref(pr, drflags);
2597 	else if (drflags & PD_LIST_SLOCKED)
2598 		sx_sunlock(&allprison_lock);
2599 	if (error && errmsg_pos >= 0) {
2600 		/* Write the error message back to userspace. */
2601 		vfs_getopt(opts, "errmsg", (void **)&errmsg, &errmsg_len);
2602 		errmsg_pos = 2 * errmsg_pos + 1;
2603 		if (errmsg_len > 0) {
2604 			if (optuio->uio_segflg == UIO_SYSSPACE)
2605 				bcopy(errmsg,
2606 				    optuio->uio_iov[errmsg_pos].iov_base,
2607 				    errmsg_len);
2608 			else
2609 				(void)copyout(errmsg,
2610 				    optuio->uio_iov[errmsg_pos].iov_base,
2611 				    errmsg_len);
2612 		}
2613 	}
2614 	vfs_freeopts(opts);
2615 	return (error);
2616 }
2617 
2618 /*
2619  * struct jail_remove_args {
2620  *	int jid;
2621  * };
2622  */
2623 int
sys_jail_remove(struct thread * td,struct jail_remove_args * uap)2624 sys_jail_remove(struct thread *td, struct jail_remove_args *uap)
2625 {
2626 	struct prison *pr;
2627 	int error;
2628 
2629 	error = priv_check(td, PRIV_JAIL_REMOVE);
2630 	if (error)
2631 		return (error);
2632 
2633 	sx_xlock(&allprison_lock);
2634 	pr = prison_find_child(td->td_ucred->cr_prison, uap->jid);
2635 	if (pr == NULL) {
2636 		sx_xunlock(&allprison_lock);
2637 		return (EINVAL);
2638 	}
2639 	if (!prison_isalive(pr)) {
2640 		/* Silently ignore already-dying prisons. */
2641 		mtx_unlock(&pr->pr_mtx);
2642 		sx_xunlock(&allprison_lock);
2643 		return (0);
2644 	}
2645 	prison_deref(pr, PD_KILL | PD_LOCKED | PD_LIST_XLOCKED);
2646 	return (0);
2647 }
2648 
2649 /*
2650  * struct jail_attach_args {
2651  *	int jid;
2652  * };
2653  */
2654 int
sys_jail_attach(struct thread * td,struct jail_attach_args * uap)2655 sys_jail_attach(struct thread *td, struct jail_attach_args *uap)
2656 {
2657 	struct prison *pr;
2658 	int error;
2659 
2660 	error = priv_check(td, PRIV_JAIL_ATTACH);
2661 	if (error)
2662 		return (error);
2663 
2664 	sx_slock(&allprison_lock);
2665 	pr = prison_find_child(td->td_ucred->cr_prison, uap->jid);
2666 	if (pr == NULL) {
2667 		sx_sunlock(&allprison_lock);
2668 		return (EINVAL);
2669 	}
2670 
2671 	/* Do not allow a process to attach to a prison that is not alive. */
2672 	if (!prison_isalive(pr)) {
2673 		mtx_unlock(&pr->pr_mtx);
2674 		sx_sunlock(&allprison_lock);
2675 		return (EINVAL);
2676 	}
2677 
2678 	return (do_jail_attach(td, pr, PD_LOCKED | PD_LIST_SLOCKED));
2679 }
2680 
2681 static int
do_jail_attach(struct thread * td,struct prison * pr,int drflags)2682 do_jail_attach(struct thread *td, struct prison *pr, int drflags)
2683 {
2684 	struct proc *p;
2685 	struct ucred *newcred, *oldcred;
2686 	int error;
2687 
2688 	mtx_assert(&pr->pr_mtx, MA_OWNED);
2689 	sx_assert(&allprison_lock, SX_LOCKED);
2690 	drflags &= PD_LOCK_FLAGS;
2691 	/*
2692 	 * XXX: Note that there is a slight race here if two threads
2693 	 * in the same privileged process attempt to attach to two
2694 	 * different jails at the same time.  It is important for
2695 	 * user processes not to do this, or they might end up with
2696 	 * a process root from one prison, but attached to the jail
2697 	 * of another.
2698 	 */
2699 	prison_hold(pr);
2700 	refcount_acquire(&pr->pr_uref);
2701 	drflags |= PD_DEREF | PD_DEUREF;
2702 	mtx_unlock(&pr->pr_mtx);
2703 	drflags &= ~PD_LOCKED;
2704 
2705 	/* Let modules do whatever they need to prepare for attaching. */
2706 	error = osd_jail_call(pr, PR_METHOD_ATTACH, td);
2707 	if (error) {
2708 		prison_deref(pr, drflags);
2709 		return (error);
2710 	}
2711 	sx_unlock(&allprison_lock);
2712 	drflags &= ~(PD_LIST_SLOCKED | PD_LIST_XLOCKED);
2713 
2714 	/*
2715 	 * Reparent the newly attached process to this jail.
2716 	 */
2717 	p = td->td_proc;
2718 	error = cpuset_setproc_update_set(p, pr->pr_cpuset);
2719 	if (error)
2720 		goto e_revert_osd;
2721 
2722 	vn_lock(pr->pr_root, LK_EXCLUSIVE | LK_RETRY);
2723 	if ((error = change_dir(pr->pr_root, td)) != 0)
2724 		goto e_unlock;
2725 #ifdef MAC
2726 	if ((error = mac_vnode_check_chroot(td->td_ucred, pr->pr_root)))
2727 		goto e_unlock;
2728 #endif
2729 	VOP_UNLOCK(pr->pr_root);
2730 	if ((error = pwd_chroot_chdir(td, pr->pr_root)))
2731 		goto e_revert_osd;
2732 
2733 	newcred = crget();
2734 	PROC_LOCK(p);
2735 	oldcred = crcopysafe(p, newcred);
2736 	newcred->cr_prison = pr;
2737 	proc_set_cred(p, newcred);
2738 	setsugid(p);
2739 #ifdef RACCT
2740 	racct_proc_ucred_changed(p, oldcred, newcred);
2741 	crhold(newcred);
2742 #endif
2743 	PROC_UNLOCK(p);
2744 #ifdef RCTL
2745 	rctl_proc_ucred_changed(p, newcred);
2746 	crfree(newcred);
2747 #endif
2748 	prison_proc_relink(oldcred->cr_prison, pr, p);
2749 	prison_deref(oldcred->cr_prison, drflags);
2750 	crfree(oldcred);
2751 
2752 	/*
2753 	 * If the prison was killed while changing credentials, die along
2754 	 * with it.
2755 	 */
2756 	if (!prison_isalive(pr)) {
2757 		PROC_LOCK(p);
2758 		kern_psignal(p, SIGKILL);
2759 		PROC_UNLOCK(p);
2760 	}
2761 
2762 	return (0);
2763 
2764  e_unlock:
2765 	VOP_UNLOCK(pr->pr_root);
2766  e_revert_osd:
2767 	/* Tell modules this thread is still in its old jail after all. */
2768 	sx_slock(&allprison_lock);
2769 	drflags |= PD_LIST_SLOCKED;
2770 	(void)osd_jail_call(td->td_ucred->cr_prison, PR_METHOD_ATTACH, td);
2771 	prison_deref(pr, drflags);
2772 	return (error);
2773 }
2774 
2775 /*
2776  * Returns a locked prison instance, or NULL on failure.
2777  */
2778 struct prison *
prison_find(int prid)2779 prison_find(int prid)
2780 {
2781 	struct prison *pr;
2782 
2783 	sx_assert(&allprison_lock, SX_LOCKED);
2784 	TAILQ_FOREACH(pr, &allprison, pr_list) {
2785 		if (pr->pr_id < prid)
2786 			continue;
2787 		if (pr->pr_id > prid)
2788 			break;
2789 		KASSERT(prison_isvalid(pr), ("Found invalid prison %p", pr));
2790 		mtx_lock(&pr->pr_mtx);
2791 		return (pr);
2792 	}
2793 	return (NULL);
2794 }
2795 
2796 /*
2797  * Find a prison that is a descendant of mypr.  Returns a locked prison or NULL.
2798  */
2799 struct prison *
prison_find_child(struct prison * mypr,int prid)2800 prison_find_child(struct prison *mypr, int prid)
2801 {
2802 	struct prison *pr;
2803 	int descend;
2804 
2805 	sx_assert(&allprison_lock, SX_LOCKED);
2806 	FOREACH_PRISON_DESCENDANT(mypr, pr, descend) {
2807 		if (pr->pr_id == prid) {
2808 			KASSERT(prison_isvalid(pr),
2809 			    ("Found invalid prison %p", pr));
2810 			mtx_lock(&pr->pr_mtx);
2811 			return (pr);
2812 		}
2813 	}
2814 	return (NULL);
2815 }
2816 
2817 /*
2818  * Look for the name relative to mypr.  Returns a locked prison or NULL.
2819  */
2820 struct prison *
prison_find_name(struct prison * mypr,const char * name)2821 prison_find_name(struct prison *mypr, const char *name)
2822 {
2823 	struct prison *pr, *deadpr;
2824 	size_t mylen;
2825 	int descend;
2826 
2827 	sx_assert(&allprison_lock, SX_LOCKED);
2828 	mylen = (mypr == &prison0) ? 0 : strlen(mypr->pr_name) + 1;
2829 	deadpr = NULL;
2830 	FOREACH_PRISON_DESCENDANT(mypr, pr, descend) {
2831 		if (!strcmp(pr->pr_name + mylen, name)) {
2832 			KASSERT(prison_isvalid(pr),
2833 			    ("Found invalid prison %p", pr));
2834 			if (prison_isalive(pr)) {
2835 				mtx_lock(&pr->pr_mtx);
2836 				return (pr);
2837 			}
2838 			deadpr = pr;
2839 		}
2840 	}
2841 	/* There was no valid prison - perhaps there was a dying one. */
2842 	if (deadpr != NULL)
2843 		mtx_lock(&deadpr->pr_mtx);
2844 	return (deadpr);
2845 }
2846 
2847 /*
2848  * See if a prison has the specific flag set.  The prison should be locked,
2849  * unless checking for flags that are only set at jail creation (such as
2850  * PR_IP4 and PR_IP6), or only the single bit is examined, without regard
2851  * to any other prison data.
2852  */
2853 bool
prison_flag(struct ucred * cred,unsigned flag)2854 prison_flag(struct ucred *cred, unsigned flag)
2855 {
2856 
2857 	return ((cred->cr_prison->pr_flags & flag) != 0);
2858 }
2859 
2860 /*
2861  * See if a prison has the specific allow flag set.
2862  * The prison *should* be locked, or only a single bit is examined, without
2863  * regard to any other prison data.
2864  */
2865 bool
prison_allow(struct ucred * cred,unsigned flag)2866 prison_allow(struct ucred *cred, unsigned flag)
2867 {
2868 
2869 	return ((cred->cr_prison->pr_allow & flag) != 0);
2870 }
2871 
2872 /*
2873  * Hold a prison reference, by incrementing pr_ref.  It is generally
2874  * an error to hold a prison that does not already have a reference.
2875  * A prison record will remain valid as long as it has at least one
2876  * reference, and will not be removed as long as either the prison
2877  * mutex or the allprison lock is held (allprison_lock may be shared).
2878  */
2879 void
prison_hold_locked(struct prison * pr)2880 prison_hold_locked(struct prison *pr)
2881 {
2882 
2883 	/* Locking is no longer required. */
2884 	prison_hold(pr);
2885 }
2886 
2887 void
prison_hold(struct prison * pr)2888 prison_hold(struct prison *pr)
2889 {
2890 #ifdef INVARIANTS
2891 	int was_valid = refcount_acquire_if_not_zero(&pr->pr_ref);
2892 
2893 	KASSERT(was_valid,
2894 	    ("Trying to hold dead prison %p (jid=%d).", pr, pr->pr_id));
2895 #else
2896 	refcount_acquire(&pr->pr_ref);
2897 #endif
2898 }
2899 
2900 /*
2901  * Remove a prison reference.  If that was the last reference, the
2902  * prison will be removed (at a later time).
2903  */
2904 void
prison_free_locked(struct prison * pr)2905 prison_free_locked(struct prison *pr)
2906 {
2907 
2908 	mtx_assert(&pr->pr_mtx, MA_OWNED);
2909 	/*
2910 	 * Locking is no longer required, but unlock because the caller
2911 	 * expects it.
2912 	 */
2913 	mtx_unlock(&pr->pr_mtx);
2914 	prison_free(pr);
2915 }
2916 
2917 void
prison_free(struct prison * pr)2918 prison_free(struct prison *pr)
2919 {
2920 
2921 	KASSERT(refcount_load(&pr->pr_ref) > 0,
2922 	    ("Trying to free dead prison %p (jid=%d).",
2923 	     pr, pr->pr_id));
2924 	if (!refcount_release_if_not_last(&pr->pr_ref)) {
2925 		/*
2926 		 * Don't remove the last reference in this context,
2927 		 * in case there are locks held.
2928 		 */
2929 		taskqueue_enqueue(taskqueue_jail_remove, &pr->pr_task);
2930 	}
2931 }
2932 
2933 static void
prison_free_not_last(struct prison * pr)2934 prison_free_not_last(struct prison *pr)
2935 {
2936 #ifdef INVARIANTS
2937 	int lastref;
2938 
2939 	KASSERT(refcount_load(&pr->pr_ref) > 0,
2940 	    ("Trying to free dead prison %p (jid=%d).",
2941 	     pr, pr->pr_id));
2942 	lastref = refcount_release(&pr->pr_ref);
2943 	KASSERT(!lastref,
2944 	    ("prison_free_not_last freed last ref on prison %p (jid=%d).",
2945 	     pr, pr->pr_id));
2946 #else
2947 	refcount_release(&pr->pr_ref);
2948 #endif
2949 }
2950 
2951 /*
2952  * Hold a prison for user visibility, by incrementing pr_uref.
2953  * It is generally an error to hold a prison that isn't already
2954  * user-visible, except through the jail system calls.  It is also
2955  * an error to hold an invalid prison.  A prison record will remain
2956  * alive as long as it has at least one user reference, and will not
2957  * be set to the dying state until the prison mutex and allprison_lock
2958  * are both freed.
2959  */
2960 void
prison_proc_hold(struct prison * pr)2961 prison_proc_hold(struct prison *pr)
2962 {
2963 #ifdef INVARIANTS
2964 	int was_alive = refcount_acquire_if_not_zero(&pr->pr_uref);
2965 
2966 	KASSERT(was_alive,
2967 	    ("Cannot add a process to a non-alive prison (jid=%d)", pr->pr_id));
2968 #else
2969 	refcount_acquire(&pr->pr_uref);
2970 #endif
2971 }
2972 
2973 /*
2974  * Remove a prison user reference.  If it was the last reference, the
2975  * prison will be considered "dying", and may be removed once all of
2976  * its references are dropped.
2977  */
2978 void
prison_proc_free(struct prison * pr)2979 prison_proc_free(struct prison *pr)
2980 {
2981 
2982 	/*
2983 	 * Locking is only required when releasing the last reference.
2984 	 * This allows assurance that a locked prison will remain alive
2985 	 * until it is unlocked.
2986 	 */
2987 	KASSERT(refcount_load(&pr->pr_uref) > 0,
2988 	    ("Trying to kill a process in a dead prison (jid=%d)", pr->pr_id));
2989 	if (!refcount_release_if_not_last(&pr->pr_uref)) {
2990 		/*
2991 		 * Don't remove the last user reference in this context,
2992 		 * which is expected to be a process that is not only locked,
2993 		 * but also half dead.  Add a reference so any calls to
2994 		 * prison_free() won't re-submit the task.
2995 		 */
2996 		prison_hold(pr);
2997 		mtx_lock(&pr->pr_mtx);
2998 		KASSERT(!(pr->pr_flags & PR_COMPLETE_PROC),
2999 		    ("Redundant last reference in prison_proc_free (jid=%d)",
3000 		     pr->pr_id));
3001 		pr->pr_flags |= PR_COMPLETE_PROC;
3002 		mtx_unlock(&pr->pr_mtx);
3003 		taskqueue_enqueue(taskqueue_jail_remove, &pr->pr_task);
3004 	}
3005 }
3006 
3007 static void
prison_proc_free_not_last(struct prison * pr)3008 prison_proc_free_not_last(struct prison *pr)
3009 {
3010 #ifdef INVARIANTS
3011 	int lastref;
3012 
3013 	KASSERT(refcount_load(&pr->pr_uref) > 0,
3014 	    ("Trying to free dead prison %p (jid=%d).",
3015 	     pr, pr->pr_id));
3016 	lastref = refcount_release(&pr->pr_uref);
3017 	KASSERT(!lastref,
3018 	    ("prison_proc_free_not_last freed last uref on prison %p (jid=%d).",
3019 	     pr, pr->pr_id));
3020 #else
3021 	refcount_release(&pr->pr_uref);
3022 #endif
3023 }
3024 
3025 void
prison_proc_link(struct prison * pr,struct proc * p)3026 prison_proc_link(struct prison *pr, struct proc *p)
3027 {
3028 
3029 	sx_assert(&allproc_lock, SA_XLOCKED);
3030 	LIST_INSERT_HEAD(&pr->pr_proclist, p, p_jaillist);
3031 }
3032 
3033 void
prison_proc_unlink(struct prison * pr,struct proc * p)3034 prison_proc_unlink(struct prison *pr, struct proc *p)
3035 {
3036 
3037 	sx_assert(&allproc_lock, SA_XLOCKED);
3038 	LIST_REMOVE(p, p_jaillist);
3039 }
3040 
3041 static void
prison_proc_relink(struct prison * opr,struct prison * npr,struct proc * p)3042 prison_proc_relink(struct prison *opr, struct prison *npr, struct proc *p)
3043 {
3044 
3045 	sx_xlock(&allproc_lock);
3046 	prison_proc_unlink(opr, p);
3047 	prison_proc_link(npr, p);
3048 	sx_xunlock(&allproc_lock);
3049 }
3050 
3051 /*
3052  * Complete a call to either prison_free or prison_proc_free.
3053  */
3054 static void
prison_complete(void * context,int pending)3055 prison_complete(void *context, int pending)
3056 {
3057 	struct prison *pr = context;
3058 	int drflags;
3059 
3060 	/*
3061 	 * This could be called to release the last reference, or the last
3062 	 * user reference (plus the reference held in prison_proc_free).
3063 	 */
3064 	drflags = prison_lock_xlock(pr, PD_DEREF);
3065 	if (pr->pr_flags & PR_COMPLETE_PROC) {
3066 		pr->pr_flags &= ~PR_COMPLETE_PROC;
3067 		drflags |= PD_DEUREF;
3068 	}
3069 	prison_deref(pr, drflags);
3070 }
3071 
3072 static void
prison_kill_processes_cb(struct proc * p,void * arg __unused)3073 prison_kill_processes_cb(struct proc *p, void *arg __unused)
3074 {
3075 
3076 	kern_psignal(p, SIGKILL);
3077 }
3078 
3079 /*
3080  * Note the iteration does not guarantee acting on all processes.
3081  * Most notably there may be fork or jail_attach in progress.
3082  */
3083 void
prison_proc_iterate(struct prison * pr,void (* cb)(struct proc *,void *),void * cbarg)3084 prison_proc_iterate(struct prison *pr, void (*cb)(struct proc *, void *),
3085     void *cbarg)
3086 {
3087 	struct prison *ppr;
3088 	struct proc *p;
3089 
3090 	if (atomic_load_int(&pr->pr_childcount) == 0) {
3091 		sx_slock(&allproc_lock);
3092 		LIST_FOREACH(p, &pr->pr_proclist, p_jaillist) {
3093 			if (p->p_state == PRS_NEW)
3094 				continue;
3095 			PROC_LOCK(p);
3096 			cb(p, cbarg);
3097 			PROC_UNLOCK(p);
3098 		}
3099 		sx_sunlock(&allproc_lock);
3100 		if (atomic_load_int(&pr->pr_childcount) == 0)
3101 			return;
3102 		/*
3103 		 * Some jails popped up during the iteration, fall through to a
3104 		 * system-wide search.
3105 		 */
3106 	}
3107 
3108 	sx_slock(&allproc_lock);
3109 	FOREACH_PROC_IN_SYSTEM(p) {
3110 		PROC_LOCK(p);
3111 		if (p->p_state != PRS_NEW && p->p_ucred != NULL) {
3112 			for (ppr = p->p_ucred->cr_prison; ppr != NULL;
3113 			    ppr = ppr->pr_parent) {
3114 				if (ppr == pr) {
3115 					cb(p, cbarg);
3116 					break;
3117 				}
3118 			}
3119 		}
3120 		PROC_UNLOCK(p);
3121 	}
3122 	sx_sunlock(&allproc_lock);
3123 }
3124 
3125 /*
3126  * Remove a prison reference and/or user reference (usually).
3127  * This assumes context that allows sleeping (for allprison_lock),
3128  * with no non-sleeping locks held, except perhaps the prison itself.
3129  * If there are no more references, release and delist the prison.
3130  * On completion, the prison lock and the allprison lock are both
3131  * unlocked.
3132  */
3133 static void
prison_deref(struct prison * pr,int flags)3134 prison_deref(struct prison *pr, int flags)
3135 {
3136 	struct prisonlist freeprison;
3137 	struct prison *killpr, *rpr, *ppr, *tpr;
3138 
3139 	killpr = NULL;
3140 	TAILQ_INIT(&freeprison);
3141 	/*
3142 	 * Release this prison as requested, which may cause its parent
3143 	 * to be released, and then maybe its grandparent, etc.
3144 	 */
3145 	for (;;) {
3146 		if (flags & PD_KILL) {
3147 			/* Kill the prison and its descendents. */
3148 			KASSERT(pr != &prison0,
3149 			    ("prison_deref trying to kill prison0"));
3150 			if (!(flags & PD_DEREF)) {
3151 				prison_hold(pr);
3152 				flags |= PD_DEREF;
3153 			}
3154 			flags = prison_lock_xlock(pr, flags);
3155 			prison_deref_kill(pr, &freeprison);
3156 		}
3157 		if (flags & PD_DEUREF) {
3158 			/* Drop a user reference. */
3159 			KASSERT(refcount_load(&pr->pr_uref) > 0,
3160 			    ("prison_deref PD_DEUREF on a dead prison (jid=%d)",
3161 			     pr->pr_id));
3162 			if (!refcount_release_if_not_last(&pr->pr_uref)) {
3163 				if (!(flags & PD_DEREF)) {
3164 					prison_hold(pr);
3165 					flags |= PD_DEREF;
3166 				}
3167 				flags = prison_lock_xlock(pr, flags);
3168 				if (refcount_release(&pr->pr_uref) &&
3169 				    pr->pr_state == PRISON_STATE_ALIVE) {
3170 					/*
3171 					 * When the last user references goes,
3172 					 * this becomes a dying prison.
3173 					 */
3174 					KASSERT(
3175 					    refcount_load(&prison0.pr_uref) > 0,
3176 					    ("prison0 pr_uref=0"));
3177 					pr->pr_state = PRISON_STATE_DYING;
3178 					mtx_unlock(&pr->pr_mtx);
3179 					flags &= ~PD_LOCKED;
3180 					prison_cleanup(pr);
3181 				}
3182 			}
3183 		}
3184 		if (flags & PD_KILL) {
3185 			/*
3186 			 * Any remaining user references are probably processes
3187 			 * that need to be killed, either in this prison or its
3188 			 * descendants.
3189 			 */
3190 			if (refcount_load(&pr->pr_uref) > 0)
3191 				killpr = pr;
3192 			/* Make sure the parent prison doesn't get killed. */
3193 			flags &= ~PD_KILL;
3194 		}
3195 		if (flags & PD_DEREF) {
3196 			/* Drop a reference. */
3197 			KASSERT(refcount_load(&pr->pr_ref) > 0,
3198 			    ("prison_deref PD_DEREF on a dead prison (jid=%d)",
3199 			     pr->pr_id));
3200 			if (!refcount_release_if_not_last(&pr->pr_ref)) {
3201 				flags = prison_lock_xlock(pr, flags);
3202 				if (refcount_release(&pr->pr_ref)) {
3203 					/*
3204 					 * When the last reference goes,
3205 					 * unlink the prison and set it aside.
3206 					 */
3207 					KASSERT(
3208 					    refcount_load(&pr->pr_uref) == 0,
3209 					    ("prison_deref: last ref, "
3210 					     "but still has %d urefs (jid=%d)",
3211 					     pr->pr_uref, pr->pr_id));
3212 					KASSERT(
3213 					    refcount_load(&prison0.pr_ref) != 0,
3214 					    ("prison0 pr_ref=0"));
3215 					pr->pr_state = PRISON_STATE_INVALID;
3216 					TAILQ_REMOVE(&allprison, pr, pr_list);
3217 					LIST_REMOVE(pr, pr_sibling);
3218 					TAILQ_INSERT_TAIL(&freeprison, pr,
3219 					    pr_list);
3220 					for (ppr = pr->pr_parent;
3221 					     ppr != NULL;
3222 					     ppr = ppr->pr_parent)
3223 						ppr->pr_childcount--;
3224 					/*
3225 					 * Removing a prison frees references
3226 					 * from its parent.
3227 					 */
3228 					ppr = pr->pr_parent;
3229 					pr->pr_parent = NULL;
3230 					mtx_unlock(&pr->pr_mtx);
3231 
3232 					pr = ppr;
3233 					flags &= ~PD_LOCKED;
3234 					flags |= PD_DEREF | PD_DEUREF;
3235 					continue;
3236 				}
3237 			}
3238 		}
3239 		break;
3240 	}
3241 
3242 	/* Release all the prison locks. */
3243 	if (flags & PD_LOCKED)
3244 		mtx_unlock(&pr->pr_mtx);
3245 	if (flags & PD_LIST_SLOCKED)
3246 		sx_sunlock(&allprison_lock);
3247 	else if (flags & PD_LIST_XLOCKED)
3248 		sx_xunlock(&allprison_lock);
3249 
3250 	/* Kill any processes attached to a killed prison. */
3251 	if (killpr != NULL)
3252 		prison_proc_iterate(killpr, prison_kill_processes_cb, NULL);
3253 
3254 	/*
3255 	 * Finish removing any unreferenced prisons, which couldn't happen
3256 	 * while allprison_lock was held (to avoid a LOR on vrele).
3257 	 */
3258 	TAILQ_FOREACH_SAFE(rpr, &freeprison, pr_list, tpr) {
3259 #ifdef VIMAGE
3260 		if (rpr->pr_flags & PR_VNET)
3261 			vnet_destroy(rpr->pr_vnet);
3262 #endif
3263 		if (rpr->pr_root != NULL)
3264 			vrele(rpr->pr_root);
3265 		mtx_destroy(&rpr->pr_mtx);
3266 #ifdef INET
3267 		prison_ip_free(rpr->pr_addrs[PR_INET]);
3268 #endif
3269 #ifdef INET6
3270 		prison_ip_free(rpr->pr_addrs[PR_INET6]);
3271 #endif
3272 		if (rpr->pr_cpuset != NULL)
3273 			cpuset_rel(rpr->pr_cpuset);
3274 		osd_jail_exit(rpr);
3275 #ifdef RACCT
3276 		if (racct_enable)
3277 			prison_racct_detach(rpr);
3278 #endif
3279 		TAILQ_REMOVE(&freeprison, rpr, pr_list);
3280 		free(rpr, M_PRISON);
3281 	}
3282 }
3283 
3284 /*
3285  * Kill the prison and its descendants.  Mark them as dying, clear the
3286  * persist flag, and call module remove methods.
3287  */
3288 static void
prison_deref_kill(struct prison * pr,struct prisonlist * freeprison)3289 prison_deref_kill(struct prison *pr, struct prisonlist *freeprison)
3290 {
3291 	struct prison *cpr, *ppr, *rpr;
3292 	bool descend;
3293 
3294 	/*
3295 	 * Unlike the descendants, the target prison can be killed
3296 	 * even if it is currently dying.  This is useful for failed
3297 	 * creation in jail_set(2).
3298 	 */
3299 	KASSERT(refcount_load(&pr->pr_ref) > 0,
3300 	    ("Trying to kill dead prison %p (jid=%d).",
3301 	     pr, pr->pr_id));
3302 	refcount_acquire(&pr->pr_uref);
3303 	pr->pr_state = PRISON_STATE_DYING;
3304 	mtx_unlock(&pr->pr_mtx);
3305 
3306 	rpr = NULL;
3307 	FOREACH_PRISON_DESCENDANT_PRE_POST(pr, cpr, descend) {
3308 		if (descend) {
3309 			if (!prison_isalive(cpr)) {
3310 				descend = false;
3311 				continue;
3312 			}
3313 			prison_hold(cpr);
3314 			prison_proc_hold(cpr);
3315 			mtx_lock(&cpr->pr_mtx);
3316 			cpr->pr_state = PRISON_STATE_DYING;
3317 			cpr->pr_flags |= PR_REMOVE;
3318 			mtx_unlock(&cpr->pr_mtx);
3319 			continue;
3320 		}
3321 		if (!(cpr->pr_flags & PR_REMOVE))
3322 			continue;
3323 		prison_cleanup(cpr);
3324 		mtx_lock(&cpr->pr_mtx);
3325 		cpr->pr_flags &= ~PR_REMOVE;
3326 		if (cpr->pr_flags & PR_PERSIST) {
3327 			cpr->pr_flags &= ~PR_PERSIST;
3328 			prison_proc_free_not_last(cpr);
3329 			prison_free_not_last(cpr);
3330 		}
3331 		(void)refcount_release(&cpr->pr_uref);
3332 		if (refcount_release(&cpr->pr_ref)) {
3333 			/*
3334 			 * When the last reference goes, unlink the prison
3335 			 * and set it aside for prison_deref() to handle.
3336 			 * Delay unlinking the sibling list to keep the loop
3337 			 * safe.
3338 			 */
3339 			if (rpr != NULL)
3340 				LIST_REMOVE(rpr, pr_sibling);
3341 			rpr = cpr;
3342 			rpr->pr_state = PRISON_STATE_INVALID;
3343 			TAILQ_REMOVE(&allprison, rpr, pr_list);
3344 			TAILQ_INSERT_TAIL(freeprison, rpr, pr_list);
3345 			/*
3346 			 * Removing a prison frees references from its parent.
3347 			 */
3348 			ppr = rpr->pr_parent;
3349 			prison_proc_free_not_last(ppr);
3350 			prison_free_not_last(ppr);
3351 			for (; ppr != NULL; ppr = ppr->pr_parent)
3352 				ppr->pr_childcount--;
3353 		}
3354 		mtx_unlock(&cpr->pr_mtx);
3355 	}
3356 	if (rpr != NULL)
3357 		LIST_REMOVE(rpr, pr_sibling);
3358 
3359 	prison_cleanup(pr);
3360 	mtx_lock(&pr->pr_mtx);
3361 	if (pr->pr_flags & PR_PERSIST) {
3362 		pr->pr_flags &= ~PR_PERSIST;
3363 		prison_proc_free_not_last(pr);
3364 		prison_free_not_last(pr);
3365 	}
3366 	(void)refcount_release(&pr->pr_uref);
3367 }
3368 
3369 /*
3370  * Given the current locking state in the flags, make sure allprison_lock
3371  * is held exclusive, and the prison is locked.  Return flags indicating
3372  * the new state.
3373  */
3374 static int
prison_lock_xlock(struct prison * pr,int flags)3375 prison_lock_xlock(struct prison *pr, int flags)
3376 {
3377 
3378 	if (!(flags & PD_LIST_XLOCKED)) {
3379 		/*
3380 		 * Get allprison_lock, which may be an upgrade,
3381 		 * and may require unlocking the prison.
3382 		 */
3383 		if (flags & PD_LOCKED) {
3384 			mtx_unlock(&pr->pr_mtx);
3385 			flags &= ~PD_LOCKED;
3386 		}
3387 		if (flags & PD_LIST_SLOCKED) {
3388 			if (!sx_try_upgrade(&allprison_lock)) {
3389 				sx_sunlock(&allprison_lock);
3390 				sx_xlock(&allprison_lock);
3391 			}
3392 			flags &= ~PD_LIST_SLOCKED;
3393 		} else
3394 			sx_xlock(&allprison_lock);
3395 		flags |= PD_LIST_XLOCKED;
3396 	}
3397 	if (!(flags & PD_LOCKED)) {
3398 		/* Lock the prison mutex. */
3399 		mtx_lock(&pr->pr_mtx);
3400 		flags |= PD_LOCKED;
3401 	}
3402 	return flags;
3403 }
3404 
3405 /*
3406  * Release a prison's resources when it starts dying (when the last user
3407  * reference is dropped, or when it is killed).
3408  */
3409 static void
prison_cleanup(struct prison * pr)3410 prison_cleanup(struct prison *pr)
3411 {
3412 	sx_assert(&allprison_lock, SA_XLOCKED);
3413 	mtx_assert(&pr->pr_mtx, MA_NOTOWNED);
3414 	vfs_exjail_delete(pr);
3415 	shm_remove_prison(pr);
3416 	(void)osd_jail_call(pr, PR_METHOD_REMOVE, NULL);
3417 }
3418 
3419 /*
3420  * Set or clear a permission bit in the pr_allow field, passing restrictions
3421  * (cleared permission) down to child jails.
3422  */
3423 void
prison_set_allow(struct ucred * cred,unsigned flag,int enable)3424 prison_set_allow(struct ucred *cred, unsigned flag, int enable)
3425 {
3426 	struct prison *pr;
3427 
3428 	pr = cred->cr_prison;
3429 	sx_slock(&allprison_lock);
3430 	mtx_lock(&pr->pr_mtx);
3431 	prison_set_allow_locked(pr, flag, enable);
3432 	mtx_unlock(&pr->pr_mtx);
3433 	sx_sunlock(&allprison_lock);
3434 }
3435 
3436 static void
prison_set_allow_locked(struct prison * pr,unsigned flag,int enable)3437 prison_set_allow_locked(struct prison *pr, unsigned flag, int enable)
3438 {
3439 	struct prison *cpr;
3440 	int descend;
3441 
3442 	if (enable != 0)
3443 		pr->pr_allow |= flag;
3444 	else {
3445 		pr->pr_allow &= ~flag;
3446 		FOREACH_PRISON_DESCENDANT_LOCKED(pr, cpr, descend)
3447 			cpr->pr_allow &= ~flag;
3448 	}
3449 }
3450 
3451 /*
3452  * Check if a jail supports the given address family.
3453  *
3454  * Returns 0 if not jailed or the address family is supported, EAFNOSUPPORT
3455  * if not.
3456  */
3457 int
prison_check_af(struct ucred * cred,int af)3458 prison_check_af(struct ucred *cred, int af)
3459 {
3460 	struct prison *pr;
3461 	int error;
3462 
3463 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3464 
3465 	pr = cred->cr_prison;
3466 #ifdef VIMAGE
3467 	/* Prisons with their own network stack are not limited. */
3468 	if (prison_owns_vnet(cred))
3469 		return (0);
3470 #endif
3471 
3472 	error = 0;
3473 	switch (af)
3474 	{
3475 #ifdef INET
3476 	case AF_INET:
3477 		if (pr->pr_flags & PR_IP4)
3478 		{
3479 			mtx_lock(&pr->pr_mtx);
3480 			if ((pr->pr_flags & PR_IP4) &&
3481 			    pr->pr_addrs[PR_INET] == NULL)
3482 				error = EAFNOSUPPORT;
3483 			mtx_unlock(&pr->pr_mtx);
3484 		}
3485 		break;
3486 #endif
3487 #ifdef INET6
3488 	case AF_INET6:
3489 		if (pr->pr_flags & PR_IP6)
3490 		{
3491 			mtx_lock(&pr->pr_mtx);
3492 			if ((pr->pr_flags & PR_IP6) &&
3493 			    pr->pr_addrs[PR_INET6] == NULL)
3494 				error = EAFNOSUPPORT;
3495 			mtx_unlock(&pr->pr_mtx);
3496 		}
3497 		break;
3498 #endif
3499 	case AF_LOCAL:
3500 	case AF_ROUTE:
3501 	case AF_NETLINK:
3502 		break;
3503 	default:
3504 		if (!(pr->pr_allow & PR_ALLOW_SOCKET_AF))
3505 			error = EAFNOSUPPORT;
3506 	}
3507 	return (error);
3508 }
3509 
3510 /*
3511  * Check if given address belongs to the jail referenced by cred (wrapper to
3512  * prison_check_ip[46]).
3513  *
3514  * Returns 0 if jail doesn't restrict the address family or if address belongs
3515  * to jail, EADDRNOTAVAIL if the address doesn't belong, or EAFNOSUPPORT if
3516  * the jail doesn't allow the address family.  IPv4 Address passed in in NBO.
3517  */
3518 int
prison_if(struct ucred * cred,const struct sockaddr * sa)3519 prison_if(struct ucred *cred, const struct sockaddr *sa)
3520 {
3521 #ifdef INET
3522 	const struct sockaddr_in *sai;
3523 #endif
3524 #ifdef INET6
3525 	const struct sockaddr_in6 *sai6;
3526 #endif
3527 	int error;
3528 
3529 	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
3530 	KASSERT(sa != NULL, ("%s: sa is NULL", __func__));
3531 
3532 #ifdef VIMAGE
3533 	if (prison_owns_vnet(cred))
3534 		return (0);
3535 #endif
3536 
3537 	error = 0;
3538 	switch (sa->sa_family)
3539 	{
3540 #ifdef INET
3541 	case AF_INET:
3542 		sai = (const struct sockaddr_in *)sa;
3543 		error = prison_check_ip4(cred, &sai->sin_addr);
3544 		break;
3545 #endif
3546 #ifdef INET6
3547 	case AF_INET6:
3548 		sai6 = (const struct sockaddr_in6 *)sa;
3549 		error = prison_check_ip6(cred, &sai6->sin6_addr);
3550 		break;
3551 #endif
3552 	default:
3553 		if (!(cred->cr_prison->pr_allow & PR_ALLOW_SOCKET_AF))
3554 			error = EAFNOSUPPORT;
3555 	}
3556 	return (error);
3557 }
3558 
3559 /*
3560  * Return 0 if jails permit p1 to frob p2, otherwise ESRCH.
3561  */
3562 int
prison_check(struct ucred * cred1,struct ucred * cred2)3563 prison_check(struct ucred *cred1, struct ucred *cred2)
3564 {
3565 
3566 	return ((cred1->cr_prison == cred2->cr_prison ||
3567 	    prison_ischild(cred1->cr_prison, cred2->cr_prison)) ? 0 : ESRCH);
3568 }
3569 
3570 /*
3571  * For mountd/nfsd to run within a prison, it must be:
3572  * - A vnet prison.
3573  * - PR_ALLOW_NFSD must be set on it.
3574  * - The root directory (pr_root) of the prison must be
3575  *   a file system mount point, so the mountd can hang
3576  *   export information on it.
3577  * - The prison's enforce_statfs cannot be 0, so that
3578  *   mountd(8) can do exports.
3579  */
3580 bool
prison_check_nfsd(struct ucred * cred)3581 prison_check_nfsd(struct ucred *cred)
3582 {
3583 
3584 	if (jailed_without_vnet(cred))
3585 		return (false);
3586 	if (!prison_allow(cred, PR_ALLOW_NFSD))
3587 		return (false);
3588 	if ((cred->cr_prison->pr_root->v_vflag & VV_ROOT) == 0)
3589 		return (false);
3590 	if (cred->cr_prison->pr_enforce_statfs == 0)
3591 		return (false);
3592 	return (true);
3593 }
3594 
3595 /*
3596  * Return true if p2 is a child of p1, otherwise false.
3597  */
3598 bool
prison_ischild(struct prison * pr1,struct prison * pr2)3599 prison_ischild(struct prison *pr1, struct prison *pr2)
3600 {
3601 
3602 	for (pr2 = pr2->pr_parent; pr2 != NULL; pr2 = pr2->pr_parent)
3603 		if (pr1 == pr2)
3604 			return (true);
3605 	return (false);
3606 }
3607 
3608 /*
3609  * Return true if the prison is currently alive.  A prison is alive if it
3610  * holds user references and it isn't being removed.
3611  */
3612 bool
prison_isalive(const struct prison * pr)3613 prison_isalive(const struct prison *pr)
3614 {
3615 
3616 	if (__predict_false(pr->pr_state != PRISON_STATE_ALIVE))
3617 		return (false);
3618 	return (true);
3619 }
3620 
3621 /*
3622  * Return true if the prison is currently valid.  A prison is valid if it has
3623  * been fully created, and is not being destroyed.  Note that dying prisons
3624  * are still considered valid.  Invalid prisons won't be found under normal
3625  * circumstances, as they're only put in that state by functions that have
3626  * an exclusive hold on allprison_lock.
3627  */
3628 bool
prison_isvalid(struct prison * pr)3629 prison_isvalid(struct prison *pr)
3630 {
3631 
3632 	if (__predict_false(pr->pr_state == PRISON_STATE_INVALID))
3633 		return (false);
3634 	if (__predict_false(refcount_load(&pr->pr_ref) == 0))
3635 		return (false);
3636 	return (true);
3637 }
3638 
3639 /*
3640  * Return true if the passed credential is in a jail and that jail does not
3641  * have its own virtual network stack, otherwise false.
3642  */
3643 bool
jailed_without_vnet(struct ucred * cred)3644 jailed_without_vnet(struct ucred *cred)
3645 {
3646 
3647 	if (!jailed(cred))
3648 		return (false);
3649 #ifdef VIMAGE
3650 	if (prison_owns_vnet(cred))
3651 		return (false);
3652 #endif
3653 
3654 	return (true);
3655 }
3656 
3657 /*
3658  * Return the correct hostname (domainname, et al) for the passed credential.
3659  */
3660 void
getcredhostname(struct ucred * cred,char * buf,size_t size)3661 getcredhostname(struct ucred *cred, char *buf, size_t size)
3662 {
3663 	struct prison *pr;
3664 
3665 	/*
3666 	 * A NULL credential can be used to shortcut to the physical
3667 	 * system's hostname.
3668 	 */
3669 	pr = (cred != NULL) ? cred->cr_prison : &prison0;
3670 	mtx_lock(&pr->pr_mtx);
3671 	strlcpy(buf, pr->pr_hostname, size);
3672 	mtx_unlock(&pr->pr_mtx);
3673 }
3674 
3675 void
getcreddomainname(struct ucred * cred,char * buf,size_t size)3676 getcreddomainname(struct ucred *cred, char *buf, size_t size)
3677 {
3678 
3679 	mtx_lock(&cred->cr_prison->pr_mtx);
3680 	strlcpy(buf, cred->cr_prison->pr_domainname, size);
3681 	mtx_unlock(&cred->cr_prison->pr_mtx);
3682 }
3683 
3684 void
getcredhostuuid(struct ucred * cred,char * buf,size_t size)3685 getcredhostuuid(struct ucred *cred, char *buf, size_t size)
3686 {
3687 
3688 	mtx_lock(&cred->cr_prison->pr_mtx);
3689 	strlcpy(buf, cred->cr_prison->pr_hostuuid, size);
3690 	mtx_unlock(&cred->cr_prison->pr_mtx);
3691 }
3692 
3693 void
getcredhostid(struct ucred * cred,unsigned long * hostid)3694 getcredhostid(struct ucred *cred, unsigned long *hostid)
3695 {
3696 
3697 	mtx_lock(&cred->cr_prison->pr_mtx);
3698 	*hostid = cred->cr_prison->pr_hostid;
3699 	mtx_unlock(&cred->cr_prison->pr_mtx);
3700 }
3701 
3702 void
getjailname(struct ucred * cred,char * name,size_t len)3703 getjailname(struct ucred *cred, char *name, size_t len)
3704 {
3705 
3706 	mtx_lock(&cred->cr_prison->pr_mtx);
3707 	strlcpy(name, cred->cr_prison->pr_name, len);
3708 	mtx_unlock(&cred->cr_prison->pr_mtx);
3709 }
3710 
3711 #ifdef VIMAGE
3712 /*
3713  * Determine whether the prison represented by cred owns
3714  * its vnet rather than having it inherited.
3715  *
3716  * Returns true in case the prison owns the vnet, false otherwise.
3717  */
3718 bool
prison_owns_vnet(struct ucred * cred)3719 prison_owns_vnet(struct ucred *cred)
3720 {
3721 
3722 	/*
3723 	 * vnets cannot be added/removed after jail creation,
3724 	 * so no need to lock here.
3725 	 */
3726 	return ((cred->cr_prison->pr_flags & PR_VNET) != 0);
3727 }
3728 #endif
3729 
3730 /*
3731  * Determine whether the subject represented by cred can "see"
3732  * status of a mount point.
3733  * Returns: 0 for permitted, ENOENT otherwise.
3734  * XXX: This function should be called cr_canseemount() and should be
3735  *      placed in kern_prot.c.
3736  */
3737 int
prison_canseemount(struct ucred * cred,struct mount * mp)3738 prison_canseemount(struct ucred *cred, struct mount *mp)
3739 {
3740 	struct prison *pr;
3741 	struct statfs *sp;
3742 	size_t len;
3743 
3744 	pr = cred->cr_prison;
3745 	if (pr->pr_enforce_statfs == 0)
3746 		return (0);
3747 	if (pr->pr_root->v_mount == mp)
3748 		return (0);
3749 	if (pr->pr_enforce_statfs == 2)
3750 		return (ENOENT);
3751 	/*
3752 	 * If jail's chroot directory is set to "/" we should be able to see
3753 	 * all mount-points from inside a jail.
3754 	 * This is ugly check, but this is the only situation when jail's
3755 	 * directory ends with '/'.
3756 	 */
3757 	if (strcmp(pr->pr_path, "/") == 0)
3758 		return (0);
3759 	len = strlen(pr->pr_path);
3760 	sp = &mp->mnt_stat;
3761 	if (strncmp(pr->pr_path, sp->f_mntonname, len) != 0)
3762 		return (ENOENT);
3763 	/*
3764 	 * Be sure that we don't have situation where jail's root directory
3765 	 * is "/some/path" and mount point is "/some/pathpath".
3766 	 */
3767 	if (sp->f_mntonname[len] != '\0' && sp->f_mntonname[len] != '/')
3768 		return (ENOENT);
3769 	return (0);
3770 }
3771 
3772 void
prison_enforce_statfs(struct ucred * cred,struct mount * mp,struct statfs * sp)3773 prison_enforce_statfs(struct ucred *cred, struct mount *mp, struct statfs *sp)
3774 {
3775 	char jpath[MAXPATHLEN];
3776 	struct prison *pr;
3777 	size_t len;
3778 
3779 	pr = cred->cr_prison;
3780 	if (pr->pr_enforce_statfs == 0)
3781 		return;
3782 	if (prison_canseemount(cred, mp) != 0) {
3783 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3784 		strlcpy(sp->f_mntonname, "[restricted]",
3785 		    sizeof(sp->f_mntonname));
3786 		return;
3787 	}
3788 	if (pr->pr_root->v_mount == mp) {
3789 		/*
3790 		 * Clear current buffer data, so we are sure nothing from
3791 		 * the valid path left there.
3792 		 */
3793 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3794 		*sp->f_mntonname = '/';
3795 		return;
3796 	}
3797 	/*
3798 	 * If jail's chroot directory is set to "/" we should be able to see
3799 	 * all mount-points from inside a jail.
3800 	 */
3801 	if (strcmp(pr->pr_path, "/") == 0)
3802 		return;
3803 	len = strlen(pr->pr_path);
3804 	strlcpy(jpath, sp->f_mntonname + len, sizeof(jpath));
3805 	/*
3806 	 * Clear current buffer data, so we are sure nothing from
3807 	 * the valid path left there.
3808 	 */
3809 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3810 	if (*jpath == '\0') {
3811 		/* Should never happen. */
3812 		*sp->f_mntonname = '/';
3813 	} else {
3814 		strlcpy(sp->f_mntonname, jpath, sizeof(sp->f_mntonname));
3815 	}
3816 }
3817 
3818 /*
3819  * Check with permission for a specific privilege is granted within jail.  We
3820  * have a specific list of accepted privileges; the rest are denied.
3821  */
3822 int
prison_priv_check(struct ucred * cred,int priv)3823 prison_priv_check(struct ucred *cred, int priv)
3824 {
3825 	struct prison *pr;
3826 	int error;
3827 
3828 	/*
3829 	 * Some policies have custom handlers. This routine should not be
3830 	 * called for them. See priv_check_cred().
3831 	 */
3832 	switch (priv) {
3833 	case PRIV_VFS_LOOKUP:
3834 	case PRIV_VFS_GENERATION:
3835 		KASSERT(0, ("prison_priv_check instead of a custom handler "
3836 		    "called for %d\n", priv));
3837 	}
3838 
3839 	if (!jailed(cred))
3840 		return (0);
3841 
3842 #ifdef VIMAGE
3843 	/*
3844 	 * Privileges specific to prisons with a virtual network stack.
3845 	 * There might be a duplicate entry here in case the privilege
3846 	 * is only granted conditionally in the legacy jail case.
3847 	 */
3848 	switch (priv) {
3849 		/*
3850 		 * NFS-specific privileges.
3851 		 */
3852 	case PRIV_NFS_DAEMON:
3853 	case PRIV_VFS_GETFH:
3854 	case PRIV_VFS_MOUNT_EXPORTED:
3855 		if (!prison_check_nfsd(cred))
3856 			return (EPERM);
3857 #ifdef notyet
3858 	case PRIV_NFS_LOCKD:
3859 #endif
3860 		/*
3861 		 * Network stack privileges.
3862 		 */
3863 	case PRIV_NET_BRIDGE:
3864 	case PRIV_NET_GRE:
3865 	case PRIV_NET_BPF:
3866 	case PRIV_NET_RAW:		/* Dup, cond. in legacy jail case. */
3867 	case PRIV_NET_ROUTE:
3868 	case PRIV_NET_TAP:
3869 	case PRIV_NET_SETIFMTU:
3870 	case PRIV_NET_SETIFFLAGS:
3871 	case PRIV_NET_SETIFCAP:
3872 	case PRIV_NET_SETIFDESCR:
3873 	case PRIV_NET_SETIFNAME	:
3874 	case PRIV_NET_SETIFMETRIC:
3875 	case PRIV_NET_SETIFPHYS:
3876 	case PRIV_NET_SETIFMAC:
3877 	case PRIV_NET_SETLANPCP:
3878 	case PRIV_NET_ADDMULTI:
3879 	case PRIV_NET_DELMULTI:
3880 	case PRIV_NET_HWIOCTL:
3881 	case PRIV_NET_SETLLADDR:
3882 	case PRIV_NET_ADDIFGROUP:
3883 	case PRIV_NET_DELIFGROUP:
3884 	case PRIV_NET_IFCREATE:
3885 	case PRIV_NET_IFDESTROY:
3886 	case PRIV_NET_ADDIFADDR:
3887 	case PRIV_NET_DELIFADDR:
3888 	case PRIV_NET_LAGG:
3889 	case PRIV_NET_GIF:
3890 	case PRIV_NET_SETIFVNET:
3891 	case PRIV_NET_SETIFFIB:
3892 	case PRIV_NET_OVPN:
3893 	case PRIV_NET_ME:
3894 	case PRIV_NET_WG:
3895 
3896 		/*
3897 		 * 802.11-related privileges.
3898 		 */
3899 	case PRIV_NET80211_VAP_GETKEY:
3900 	case PRIV_NET80211_VAP_MANAGE:
3901 
3902 #ifdef notyet
3903 		/*
3904 		 * ATM privileges.
3905 		 */
3906 	case PRIV_NETATM_CFG:
3907 	case PRIV_NETATM_ADD:
3908 	case PRIV_NETATM_DEL:
3909 	case PRIV_NETATM_SET:
3910 
3911 		/*
3912 		 * Bluetooth privileges.
3913 		 */
3914 	case PRIV_NETBLUETOOTH_RAW:
3915 #endif
3916 
3917 		/*
3918 		 * Netgraph and netgraph module privileges.
3919 		 */
3920 	case PRIV_NETGRAPH_CONTROL:
3921 #ifdef notyet
3922 	case PRIV_NETGRAPH_TTY:
3923 #endif
3924 
3925 		/*
3926 		 * IPv4 and IPv6 privileges.
3927 		 */
3928 	case PRIV_NETINET_IPFW:
3929 	case PRIV_NETINET_DIVERT:
3930 	case PRIV_NETINET_PF:
3931 	case PRIV_NETINET_DUMMYNET:
3932 	case PRIV_NETINET_CARP:
3933 	case PRIV_NETINET_MROUTE:
3934 	case PRIV_NETINET_RAW:
3935 	case PRIV_NETINET_ADDRCTRL6:
3936 	case PRIV_NETINET_ND6:
3937 	case PRIV_NETINET_SCOPE6:
3938 	case PRIV_NETINET_ALIFETIME6:
3939 	case PRIV_NETINET_IPSEC:
3940 	case PRIV_NETINET_BINDANY:
3941 
3942 #ifdef notyet
3943 		/*
3944 		 * NCP privileges.
3945 		 */
3946 	case PRIV_NETNCP:
3947 
3948 		/*
3949 		 * SMB privileges.
3950 		 */
3951 	case PRIV_NETSMB:
3952 #endif
3953 
3954 	/*
3955 	 * No default: or deny here.
3956 	 * In case of no permit fall through to next switch().
3957 	 */
3958 		if (cred->cr_prison->pr_flags & PR_VNET)
3959 			return (0);
3960 	}
3961 #endif /* VIMAGE */
3962 
3963 	switch (priv) {
3964 		/*
3965 		 * Allow ktrace privileges for root in jail.
3966 		 */
3967 	case PRIV_KTRACE:
3968 
3969 #if 0
3970 		/*
3971 		 * Allow jailed processes to configure audit identity and
3972 		 * submit audit records (login, etc).  In the future we may
3973 		 * want to further refine the relationship between audit and
3974 		 * jail.
3975 		 */
3976 	case PRIV_AUDIT_GETAUDIT:
3977 	case PRIV_AUDIT_SETAUDIT:
3978 	case PRIV_AUDIT_SUBMIT:
3979 #endif
3980 
3981 		/*
3982 		 * Allow jailed processes to manipulate process UNIX
3983 		 * credentials in any way they see fit.
3984 		 */
3985 	case PRIV_CRED_SETCRED:
3986 	case PRIV_CRED_SETUID:
3987 	case PRIV_CRED_SETEUID:
3988 	case PRIV_CRED_SETGID:
3989 	case PRIV_CRED_SETEGID:
3990 	case PRIV_CRED_SETGROUPS:
3991 	case PRIV_CRED_SETREUID:
3992 	case PRIV_CRED_SETREGID:
3993 	case PRIV_CRED_SETRESUID:
3994 	case PRIV_CRED_SETRESGID:
3995 
3996 		/*
3997 		 * Jail implements visibility constraints already, so allow
3998 		 * jailed root to override uid/gid-based constraints.
3999 		 */
4000 	case PRIV_SEEOTHERGIDS:
4001 	case PRIV_SEEOTHERUIDS:
4002 	case PRIV_SEEJAILPROC:
4003 
4004 		/*
4005 		 * Jail implements inter-process debugging limits already, so
4006 		 * allow jailed root various debugging privileges.
4007 		 */
4008 	case PRIV_DEBUG_DIFFCRED:
4009 	case PRIV_DEBUG_SUGID:
4010 	case PRIV_DEBUG_UNPRIV:
4011 
4012 		/*
4013 		 * Allow jail to set various resource limits and login
4014 		 * properties, and for now, exceed process resource limits.
4015 		 */
4016 	case PRIV_PROC_LIMIT:
4017 	case PRIV_PROC_SETLOGIN:
4018 	case PRIV_PROC_SETRLIMIT:
4019 
4020 		/*
4021 		 * System V and POSIX IPC privileges are granted in jail.
4022 		 */
4023 	case PRIV_IPC_READ:
4024 	case PRIV_IPC_WRITE:
4025 	case PRIV_IPC_ADMIN:
4026 	case PRIV_IPC_MSGSIZE:
4027 	case PRIV_MQ_ADMIN:
4028 
4029 		/*
4030 		 * Jail operations within a jail work on child jails.
4031 		 */
4032 	case PRIV_JAIL_ATTACH:
4033 	case PRIV_JAIL_SET:
4034 	case PRIV_JAIL_REMOVE:
4035 
4036 		/*
4037 		 * Jail implements its own inter-process limits, so allow
4038 		 * root processes in jail to change scheduling on other
4039 		 * processes in the same jail.  Likewise for signalling.
4040 		 */
4041 	case PRIV_SCHED_DIFFCRED:
4042 	case PRIV_SCHED_CPUSET:
4043 	case PRIV_SIGNAL_DIFFCRED:
4044 	case PRIV_SIGNAL_SUGID:
4045 
4046 		/*
4047 		 * Allow jailed processes to write to sysctls marked as jail
4048 		 * writable.
4049 		 */
4050 	case PRIV_SYSCTL_WRITEJAIL:
4051 
4052 		/*
4053 		 * Allow root in jail to manage a variety of quota
4054 		 * properties.  These should likely be conditional on a
4055 		 * configuration option.
4056 		 */
4057 	case PRIV_VFS_GETQUOTA:
4058 	case PRIV_VFS_SETQUOTA:
4059 
4060 		/*
4061 		 * Since Jail relies on chroot() to implement file system
4062 		 * protections, grant many VFS privileges to root in jail.
4063 		 * Be careful to exclude mount-related and NFS-related
4064 		 * privileges.
4065 		 */
4066 	case PRIV_VFS_READ:
4067 	case PRIV_VFS_WRITE:
4068 	case PRIV_VFS_ADMIN:
4069 	case PRIV_VFS_EXEC:
4070 	case PRIV_VFS_BLOCKRESERVE:	/* XXXRW: Slightly surprising. */
4071 	case PRIV_VFS_CHFLAGS_DEV:
4072 	case PRIV_VFS_CHOWN:
4073 	case PRIV_VFS_CHROOT:
4074 	case PRIV_VFS_RETAINSUGID:
4075 	case PRIV_VFS_FCHROOT:
4076 	case PRIV_VFS_LINK:
4077 	case PRIV_VFS_SETGID:
4078 	case PRIV_VFS_STAT:
4079 	case PRIV_VFS_STICKYFILE:
4080 
4081 		/*
4082 		 * As in the non-jail case, non-root users are expected to be
4083 		 * able to read kernel/physical memory (provided /dev/[k]mem
4084 		 * exists in the jail and they have permission to access it).
4085 		 */
4086 	case PRIV_KMEM_READ:
4087 		return (0);
4088 
4089 		/*
4090 		 * Depending on the global setting, allow privilege of
4091 		 * setting system flags.
4092 		 */
4093 	case PRIV_VFS_SYSFLAGS:
4094 		if (cred->cr_prison->pr_allow & PR_ALLOW_CHFLAGS)
4095 			return (0);
4096 		else
4097 			return (EPERM);
4098 
4099 		/*
4100 		 * Depending on the global setting, allow privilege of
4101 		 * mounting/unmounting file systems.
4102 		 */
4103 	case PRIV_VFS_MOUNT:
4104 	case PRIV_VFS_UNMOUNT:
4105 	case PRIV_VFS_MOUNT_NONUSER:
4106 	case PRIV_VFS_MOUNT_OWNER:
4107 		pr = cred->cr_prison;
4108 		prison_lock(pr);
4109 		if (pr->pr_allow & PR_ALLOW_MOUNT && pr->pr_enforce_statfs < 2)
4110 			error = 0;
4111 		else
4112 			error = EPERM;
4113 		prison_unlock(pr);
4114 		return (error);
4115 
4116 		/*
4117 		 * Jails should hold no disposition on the PRIV_VFS_READ_DIR
4118 		 * policy.  priv_check_cred will not specifically allow it, and
4119 		 * we may want a MAC policy to allow it.
4120 		 */
4121 	case PRIV_VFS_READ_DIR:
4122 		return (0);
4123 
4124 		/*
4125 		 * Conditionally allow privileged process in the jail to
4126 		 * manipulate filesystem extended attributes in the system
4127 		 * namespace.
4128 		 */
4129 	case PRIV_VFS_EXTATTR_SYSTEM:
4130 		if ((cred->cr_prison->pr_allow & PR_ALLOW_EXTATTR) != 0)
4131 			return (0);
4132 		else
4133 			return (EPERM);
4134 
4135 		/*
4136 		 * Conditionnaly allow locking (unlocking) physical pages
4137 		 * in memory.
4138 		 */
4139 	case PRIV_VM_MLOCK:
4140 	case PRIV_VM_MUNLOCK:
4141 		if (cred->cr_prison->pr_allow & PR_ALLOW_MLOCK)
4142 			return (0);
4143 		else
4144 			return (EPERM);
4145 
4146 		/*
4147 		 * Conditionally allow jailed root to bind reserved ports.
4148 		 */
4149 	case PRIV_NETINET_RESERVEDPORT:
4150 		if (cred->cr_prison->pr_allow & PR_ALLOW_RESERVED_PORTS)
4151 			return (0);
4152 		else
4153 			return (EPERM);
4154 
4155 		/*
4156 		 * Allow jailed root to reuse in-use ports.
4157 		 */
4158 	case PRIV_NETINET_REUSEPORT:
4159 		return (0);
4160 
4161 		/*
4162 		 * Allow jailed root to set certain IPv4/6 (option) headers.
4163 		 */
4164 	case PRIV_NETINET_SETHDROPTS:
4165 		return (0);
4166 
4167 		/*
4168 		 * Conditionally allow creating raw sockets in jail.
4169 		 */
4170 	case PRIV_NETINET_RAW:
4171 		if (cred->cr_prison->pr_allow & PR_ALLOW_RAW_SOCKETS)
4172 			return (0);
4173 		else
4174 			return (EPERM);
4175 
4176 		/*
4177 		 * Since jail implements its own visibility limits on netstat
4178 		 * sysctls, allow getcred.  This allows identd to work in
4179 		 * jail.
4180 		 */
4181 	case PRIV_NETINET_GETCRED:
4182 		return (0);
4183 
4184 		/*
4185 		 * Allow jailed root to set loginclass.
4186 		 */
4187 	case PRIV_PROC_SETLOGINCLASS:
4188 		return (0);
4189 
4190 		/*
4191 		 * Do not allow a process inside a jail to read the kernel
4192 		 * message buffer unless explicitly permitted.
4193 		 */
4194 	case PRIV_MSGBUF:
4195 		if (cred->cr_prison->pr_allow & PR_ALLOW_READ_MSGBUF)
4196 			return (0);
4197 		return (EPERM);
4198 
4199 		/*
4200 		 * Conditionally allow privileged process in the jail adjust
4201 		 * machine time.
4202 		 */
4203 	case PRIV_ADJTIME:
4204 	case PRIV_NTP_ADJTIME:
4205 		if (cred->cr_prison->pr_allow &
4206 		    (PR_ALLOW_ADJTIME | PR_ALLOW_SETTIME)) {
4207 			return (0);
4208 		}
4209 		return (EPERM);
4210 
4211 		/*
4212 		 * Conditionally allow privileged process in the jail set
4213 		 * machine time.
4214 		 */
4215 	case PRIV_CLOCK_SETTIME:
4216 		if (cred->cr_prison->pr_allow & PR_ALLOW_SETTIME)
4217 			return (0);
4218 		else
4219 			return (EPERM);
4220 
4221 	default:
4222 		/*
4223 		 * In all remaining cases, deny the privilege request.  This
4224 		 * includes almost all network privileges, many system
4225 		 * configuration privileges.
4226 		 */
4227 		return (EPERM);
4228 	}
4229 }
4230 
4231 /*
4232  * Return the part of pr2's name that is relative to pr1, or the whole name
4233  * if it does not directly follow.
4234  */
4235 
4236 char *
prison_name(struct prison * pr1,struct prison * pr2)4237 prison_name(struct prison *pr1, struct prison *pr2)
4238 {
4239 	char *name;
4240 
4241 	/* Jails see themselves as "0" (if they see themselves at all). */
4242 	if (pr1 == pr2)
4243 		return "0";
4244 	name = pr2->pr_name;
4245 	if (prison_ischild(pr1, pr2)) {
4246 		/*
4247 		 * pr1 isn't locked (and allprison_lock may not be either)
4248 		 * so its length can't be counted on.  But the number of dots
4249 		 * can be counted on - and counted.
4250 		 */
4251 		for (; pr1 != &prison0; pr1 = pr1->pr_parent)
4252 			name = strchr(name, '.') + 1;
4253 	}
4254 	return (name);
4255 }
4256 
4257 /*
4258  * Return the part of pr2's path that is relative to pr1, or the whole path
4259  * if it does not directly follow.
4260  */
4261 static char *
prison_path(struct prison * pr1,struct prison * pr2)4262 prison_path(struct prison *pr1, struct prison *pr2)
4263 {
4264 	char *path1, *path2;
4265 	int len1;
4266 
4267 	path1 = pr1->pr_path;
4268 	path2 = pr2->pr_path;
4269 	if (!strcmp(path1, "/"))
4270 		return (path2);
4271 	len1 = strlen(path1);
4272 	if (strncmp(path1, path2, len1))
4273 		return (path2);
4274 	if (path2[len1] == '\0')
4275 		return "/";
4276 	if (path2[len1] == '/')
4277 		return (path2 + len1);
4278 	return (path2);
4279 }
4280 
4281 /*
4282  * Jail-related sysctls.
4283  */
4284 SYSCTL_NODE(_security, OID_AUTO, jail, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
4285     "Jails");
4286 
4287 #if defined(INET) || defined(INET6)
4288 /*
4289  * Copy address array to memory that would be then SYSCTL_OUT-ed.
4290  * sysctl_jail_list() helper.
4291  */
4292 static void
prison_ip_copyout(struct prison * pr,const pr_family_t af,void ** out,int * len)4293 prison_ip_copyout(struct prison *pr, const pr_family_t af, void **out, int *len)
4294 {
4295 	const struct prison_ip *pip;
4296 	const size_t size = pr_families[af].size;
4297 
4298  again:
4299 	mtx_assert(&pr->pr_mtx, MA_OWNED);
4300 	if ((pip = pr->pr_addrs[af]) != NULL) {
4301 		if (*len < pip->ips) {
4302 			*len = pip->ips;
4303 			mtx_unlock(&pr->pr_mtx);
4304 			*out = realloc(*out, *len * size, M_TEMP, M_WAITOK);
4305 			mtx_lock(&pr->pr_mtx);
4306 			goto again;
4307 		}
4308 		bcopy(pip->pr_ip, *out, pip->ips * size);
4309 	}
4310 }
4311 #endif
4312 
4313 static int
sysctl_jail_list(SYSCTL_HANDLER_ARGS)4314 sysctl_jail_list(SYSCTL_HANDLER_ARGS)
4315 {
4316 	struct xprison *xp;
4317 	struct prison *pr, *cpr;
4318 #ifdef INET
4319 	struct in_addr *ip4 = NULL;
4320 	int ip4s = 0;
4321 #endif
4322 #ifdef INET6
4323 	struct in6_addr *ip6 = NULL;
4324 	int ip6s = 0;
4325 #endif
4326 	int descend, error;
4327 
4328 	xp = malloc(sizeof(*xp), M_TEMP, M_WAITOK);
4329 	pr = req->td->td_ucred->cr_prison;
4330 	error = 0;
4331 	sx_slock(&allprison_lock);
4332 	FOREACH_PRISON_DESCENDANT(pr, cpr, descend) {
4333 		mtx_lock(&cpr->pr_mtx);
4334 #ifdef INET
4335 		prison_ip_copyout(cpr, PR_INET, (void **)&ip4, &ip4s);
4336 #endif
4337 #ifdef INET6
4338 		prison_ip_copyout(cpr, PR_INET6, (void **)&ip6, &ip6s);
4339 #endif
4340 		bzero(xp, sizeof(*xp));
4341 		xp->pr_version = XPRISON_VERSION;
4342 		xp->pr_id = cpr->pr_id;
4343 		xp->pr_state = cpr->pr_state;
4344 		strlcpy(xp->pr_path, prison_path(pr, cpr), sizeof(xp->pr_path));
4345 		strlcpy(xp->pr_host, cpr->pr_hostname, sizeof(xp->pr_host));
4346 		strlcpy(xp->pr_name, prison_name(pr, cpr), sizeof(xp->pr_name));
4347 #ifdef INET
4348 		xp->pr_ip4s = ip4s;
4349 #endif
4350 #ifdef INET6
4351 		xp->pr_ip6s = ip6s;
4352 #endif
4353 		mtx_unlock(&cpr->pr_mtx);
4354 		error = SYSCTL_OUT(req, xp, sizeof(*xp));
4355 		if (error)
4356 			break;
4357 #ifdef INET
4358 		if (xp->pr_ip4s > 0) {
4359 			error = SYSCTL_OUT(req, ip4,
4360 			    xp->pr_ip4s * sizeof(struct in_addr));
4361 			if (error)
4362 				break;
4363 		}
4364 #endif
4365 #ifdef INET6
4366 		if (xp->pr_ip6s > 0) {
4367 			error = SYSCTL_OUT(req, ip6,
4368 			    xp->pr_ip6s * sizeof(struct in6_addr));
4369 			if (error)
4370 				break;
4371 		}
4372 #endif
4373 	}
4374 	sx_sunlock(&allprison_lock);
4375 	free(xp, M_TEMP);
4376 #ifdef INET
4377 	free(ip4, M_TEMP);
4378 #endif
4379 #ifdef INET6
4380 	free(ip6, M_TEMP);
4381 #endif
4382 	return (error);
4383 }
4384 
4385 SYSCTL_OID(_security_jail, OID_AUTO, list,
4386     CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
4387     sysctl_jail_list, "S", "List of active jails");
4388 
4389 static int
sysctl_jail_jailed(SYSCTL_HANDLER_ARGS)4390 sysctl_jail_jailed(SYSCTL_HANDLER_ARGS)
4391 {
4392 	int error, injail;
4393 
4394 	injail = jailed(req->td->td_ucred);
4395 	error = SYSCTL_OUT(req, &injail, sizeof(injail));
4396 
4397 	return (error);
4398 }
4399 
4400 SYSCTL_PROC(_security_jail, OID_AUTO, jailed,
4401     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
4402     sysctl_jail_jailed, "I", "Process in jail?");
4403 
4404 static int
sysctl_jail_vnet(SYSCTL_HANDLER_ARGS)4405 sysctl_jail_vnet(SYSCTL_HANDLER_ARGS)
4406 {
4407 	int error, havevnet;
4408 #ifdef VIMAGE
4409 	struct ucred *cred = req->td->td_ucred;
4410 
4411 	havevnet = jailed(cred) && prison_owns_vnet(cred);
4412 #else
4413 	havevnet = 0;
4414 #endif
4415 	error = SYSCTL_OUT(req, &havevnet, sizeof(havevnet));
4416 
4417 	return (error);
4418 }
4419 
4420 SYSCTL_PROC(_security_jail, OID_AUTO, vnet,
4421     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
4422     sysctl_jail_vnet, "I", "Jail owns vnet?");
4423 
4424 #if defined(INET) || defined(INET6)
4425 SYSCTL_UINT(_security_jail, OID_AUTO, jail_max_af_ips, CTLFLAG_RW,
4426     &jail_max_af_ips, 0,
4427     "Number of IP addresses a jail may have at most per address family (deprecated)");
4428 #endif
4429 
4430 /*
4431  * Default parameters for jail(2) compatibility.  For historical reasons,
4432  * the sysctl names have varying similarity to the parameter names.  Prisons
4433  * just see their own parameters, and can't change them.
4434  */
4435 static int
sysctl_jail_default_allow(SYSCTL_HANDLER_ARGS)4436 sysctl_jail_default_allow(SYSCTL_HANDLER_ARGS)
4437 {
4438 	int error, i;
4439 
4440 	/* Get the current flag value, and convert it to a boolean. */
4441 	if (req->td->td_ucred->cr_prison == &prison0) {
4442 		mtx_lock(&prison0.pr_mtx);
4443 		i = (jail_default_allow & arg2) != 0;
4444 		mtx_unlock(&prison0.pr_mtx);
4445 	} else
4446 		i = prison_allow(req->td->td_ucred, arg2);
4447 
4448 	if (arg1 != NULL)
4449 		i = !i;
4450 	error = sysctl_handle_int(oidp, &i, 0, req);
4451 	if (error || !req->newptr)
4452 		return (error);
4453 	i = i ? arg2 : 0;
4454 	if (arg1 != NULL)
4455 		i ^= arg2;
4456 	/*
4457 	 * The sysctls don't have CTLFLAGS_PRISON, so assume prison0
4458 	 * for writing.
4459 	 */
4460 	mtx_lock(&prison0.pr_mtx);
4461 	jail_default_allow = (jail_default_allow & ~arg2) | i;
4462 	mtx_unlock(&prison0.pr_mtx);
4463 	return (0);
4464 }
4465 
4466 SYSCTL_PROC(_security_jail, OID_AUTO, set_hostname_allowed,
4467     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4468     NULL, PR_ALLOW_SET_HOSTNAME, sysctl_jail_default_allow, "I",
4469     "Processes in jail can set their hostnames (deprecated)");
4470 SYSCTL_PROC(_security_jail, OID_AUTO, socket_unixiproute_only,
4471     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4472     (void *)1, PR_ALLOW_SOCKET_AF, sysctl_jail_default_allow, "I",
4473     "Processes in jail are limited to creating UNIX/IP/route sockets only (deprecated)");
4474 SYSCTL_PROC(_security_jail, OID_AUTO, sysvipc_allowed,
4475     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4476     NULL, PR_ALLOW_SYSVIPC, sysctl_jail_default_allow, "I",
4477     "Processes in jail can use System V IPC primitives (deprecated)");
4478 SYSCTL_PROC(_security_jail, OID_AUTO, allow_raw_sockets,
4479     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4480     NULL, PR_ALLOW_RAW_SOCKETS, sysctl_jail_default_allow, "I",
4481     "Prison root can create raw sockets (deprecated)");
4482 SYSCTL_PROC(_security_jail, OID_AUTO, chflags_allowed,
4483     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4484     NULL, PR_ALLOW_CHFLAGS, sysctl_jail_default_allow, "I",
4485     "Processes in jail can alter system file flags (deprecated)");
4486 SYSCTL_PROC(_security_jail, OID_AUTO, mount_allowed,
4487     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4488     NULL, PR_ALLOW_MOUNT, sysctl_jail_default_allow, "I",
4489     "Processes in jail can mount/unmount jail-friendly file systems (deprecated)");
4490 SYSCTL_PROC(_security_jail, OID_AUTO, mlock_allowed,
4491     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4492     NULL, PR_ALLOW_MLOCK, sysctl_jail_default_allow, "I",
4493     "Processes in jail can lock/unlock physical pages in memory");
4494 
4495 static int
sysctl_jail_default_level(SYSCTL_HANDLER_ARGS)4496 sysctl_jail_default_level(SYSCTL_HANDLER_ARGS)
4497 {
4498 	struct prison *pr;
4499 	int level, error;
4500 
4501 	pr = req->td->td_ucred->cr_prison;
4502 	level = (pr == &prison0) ? *(int *)arg1 : *(int *)((char *)pr + arg2);
4503 	error = sysctl_handle_int(oidp, &level, 0, req);
4504 	if (error || !req->newptr)
4505 		return (error);
4506 	*(int *)arg1 = level;
4507 	return (0);
4508 }
4509 
4510 SYSCTL_PROC(_security_jail, OID_AUTO, enforce_statfs,
4511     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4512     &jail_default_enforce_statfs, offsetof(struct prison, pr_enforce_statfs),
4513     sysctl_jail_default_level, "I",
4514     "Processes in jail cannot see all mounted file systems (deprecated)");
4515 
4516 SYSCTL_PROC(_security_jail, OID_AUTO, devfs_ruleset,
4517     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
4518     &jail_default_devfs_rsnum, offsetof(struct prison, pr_devfs_rsnum),
4519     sysctl_jail_default_level, "I",
4520     "Ruleset for the devfs filesystem in jail (deprecated)");
4521 
4522 SYSCTL_NODE(_security_jail, OID_AUTO, children, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
4523     "Limits and stats of child jails");
4524 
4525 static int
sysctl_jail_children(SYSCTL_HANDLER_ARGS)4526 sysctl_jail_children(SYSCTL_HANDLER_ARGS)
4527 {
4528 	struct prison *pr;
4529 	int i;
4530 
4531 	pr = req->td->td_ucred->cr_prison;
4532 
4533 	switch (oidp->oid_kind & CTLTYPE) {
4534 	case CTLTYPE_INT:
4535 		i = *(int *)((char *)pr + arg2);
4536 		return (SYSCTL_OUT(req, &i, sizeof(i)));
4537 	}
4538 
4539 	return (0);
4540 }
4541 
4542 SYSCTL_PROC(_security_jail_children, OID_AUTO, max,
4543     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
4544     NULL, offsetof(struct prison, pr_childmax), sysctl_jail_children,
4545     "I", "Maximum number of child jails");
4546 SYSCTL_PROC(_security_jail_children, OID_AUTO, cur,
4547     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
4548     NULL, offsetof(struct prison, pr_childcount), sysctl_jail_children,
4549     "I", "Current number of child jails");
4550 
4551 /*
4552  * Nodes to describe jail parameters.  Maximum length of string parameters
4553  * is returned in the string itself, and the other parameters exist merely
4554  * to make themselves and their types known.
4555  */
4556 SYSCTL_NODE(_security_jail, OID_AUTO, param, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
4557     "Jail parameters");
4558 
4559 int
sysctl_jail_param(SYSCTL_HANDLER_ARGS)4560 sysctl_jail_param(SYSCTL_HANDLER_ARGS)
4561 {
4562 	int i;
4563 	long l;
4564 	size_t s;
4565 	char numbuf[12];
4566 
4567 	switch (oidp->oid_kind & CTLTYPE)
4568 	{
4569 	case CTLTYPE_LONG:
4570 	case CTLTYPE_ULONG:
4571 		l = 0;
4572 #ifdef SCTL_MASK32
4573 		if (!(req->flags & SCTL_MASK32))
4574 #endif
4575 			return (SYSCTL_OUT(req, &l, sizeof(l)));
4576 	case CTLTYPE_INT:
4577 	case CTLTYPE_UINT:
4578 		i = 0;
4579 		return (SYSCTL_OUT(req, &i, sizeof(i)));
4580 	case CTLTYPE_STRING:
4581 		snprintf(numbuf, sizeof(numbuf), "%jd", (intmax_t)arg2);
4582 		return
4583 		    (sysctl_handle_string(oidp, numbuf, sizeof(numbuf), req));
4584 	case CTLTYPE_STRUCT:
4585 		s = (size_t)arg2;
4586 		return (SYSCTL_OUT(req, &s, sizeof(s)));
4587 	}
4588 	return (0);
4589 }
4590 
4591 /*
4592  * CTLFLAG_RDTUN in the following indicates jail parameters that can be set at
4593  * jail creation time but cannot be changed in an existing jail.
4594  */
4595 SYSCTL_JAIL_PARAM(, jid, CTLTYPE_INT | CTLFLAG_RDTUN, "I", "Jail ID");
4596 SYSCTL_JAIL_PARAM(, parent, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail parent ID");
4597 SYSCTL_JAIL_PARAM_STRING(, name, CTLFLAG_RW, MAXHOSTNAMELEN, "Jail name");
4598 SYSCTL_JAIL_PARAM_STRING(, path, CTLFLAG_RDTUN, MAXPATHLEN, "Jail root path");
4599 SYSCTL_JAIL_PARAM(, securelevel, CTLTYPE_INT | CTLFLAG_RW,
4600     "I", "Jail secure level");
4601 SYSCTL_JAIL_PARAM(, osreldate, CTLTYPE_INT | CTLFLAG_RDTUN, "I",
4602     "Jail value for kern.osreldate and uname -K");
4603 SYSCTL_JAIL_PARAM_STRING(, osrelease, CTLFLAG_RDTUN, OSRELEASELEN,
4604     "Jail value for kern.osrelease and uname -r");
4605 SYSCTL_JAIL_PARAM(, enforce_statfs, CTLTYPE_INT | CTLFLAG_RW,
4606     "I", "Jail cannot see all mounted file systems");
4607 SYSCTL_JAIL_PARAM(, devfs_ruleset, CTLTYPE_INT | CTLFLAG_RW,
4608     "I", "Ruleset for in-jail devfs mounts");
4609 SYSCTL_JAIL_PARAM(, persist, CTLTYPE_INT | CTLFLAG_RW,
4610     "B", "Jail persistence");
4611 #ifdef VIMAGE
4612 SYSCTL_JAIL_PARAM(, vnet, CTLTYPE_INT | CTLFLAG_RDTUN,
4613     "E,jailsys", "Virtual network stack");
4614 #endif
4615 SYSCTL_JAIL_PARAM(, dying, CTLTYPE_INT | CTLFLAG_RD,
4616     "B", "Jail is in the process of shutting down");
4617 
4618 SYSCTL_JAIL_PARAM_NODE(children, "Number of child jails");
4619 SYSCTL_JAIL_PARAM(_children, cur, CTLTYPE_INT | CTLFLAG_RD,
4620     "I", "Current number of child jails");
4621 SYSCTL_JAIL_PARAM(_children, max, CTLTYPE_INT | CTLFLAG_RW,
4622     "I", "Maximum number of child jails");
4623 
4624 SYSCTL_JAIL_PARAM_SYS_NODE(host, CTLFLAG_RW, "Jail host info");
4625 SYSCTL_JAIL_PARAM_STRING(_host, hostname, CTLFLAG_RW, MAXHOSTNAMELEN,
4626     "Jail hostname");
4627 SYSCTL_JAIL_PARAM_STRING(_host, domainname, CTLFLAG_RW, MAXHOSTNAMELEN,
4628     "Jail NIS domainname");
4629 SYSCTL_JAIL_PARAM_STRING(_host, hostuuid, CTLFLAG_RW, HOSTUUIDLEN,
4630     "Jail host UUID");
4631 SYSCTL_JAIL_PARAM(_host, hostid, CTLTYPE_ULONG | CTLFLAG_RW,
4632     "LU", "Jail host ID");
4633 
4634 SYSCTL_JAIL_PARAM_NODE(cpuset, "Jail cpuset");
4635 SYSCTL_JAIL_PARAM(_cpuset, id, CTLTYPE_INT | CTLFLAG_RD, "I", "Jail cpuset ID");
4636 
4637 #ifdef INET
4638 SYSCTL_JAIL_PARAM_SYS_NODE(ip4, CTLFLAG_RDTUN,
4639     "Jail IPv4 address virtualization");
4640 SYSCTL_JAIL_PARAM_STRUCT(_ip4, addr, CTLFLAG_RW, sizeof(struct in_addr),
4641     "S,in_addr,a", "Jail IPv4 addresses");
4642 SYSCTL_JAIL_PARAM(_ip4, saddrsel, CTLTYPE_INT | CTLFLAG_RW,
4643     "B", "Do (not) use IPv4 source address selection rather than the "
4644     "primary jail IPv4 address.");
4645 #endif
4646 #ifdef INET6
4647 SYSCTL_JAIL_PARAM_SYS_NODE(ip6, CTLFLAG_RDTUN,
4648     "Jail IPv6 address virtualization");
4649 SYSCTL_JAIL_PARAM_STRUCT(_ip6, addr, CTLFLAG_RW, sizeof(struct in6_addr),
4650     "S,in6_addr,a", "Jail IPv6 addresses");
4651 SYSCTL_JAIL_PARAM(_ip6, saddrsel, CTLTYPE_INT | CTLFLAG_RW,
4652     "B", "Do (not) use IPv6 source address selection rather than the "
4653     "primary jail IPv6 address.");
4654 #endif
4655 
4656 SYSCTL_JAIL_PARAM_NODE(allow, "Jail permission flags");
4657 SYSCTL_JAIL_PARAM(_allow, set_hostname, CTLTYPE_INT | CTLFLAG_RW,
4658     "B", "Jail may set hostname");
4659 SYSCTL_JAIL_PARAM(_allow, sysvipc, CTLTYPE_INT | CTLFLAG_RW,
4660     "B", "Jail may use SYSV IPC");
4661 SYSCTL_JAIL_PARAM(_allow, raw_sockets, CTLTYPE_INT | CTLFLAG_RW,
4662     "B", "Jail may create raw sockets");
4663 SYSCTL_JAIL_PARAM(_allow, chflags, CTLTYPE_INT | CTLFLAG_RW,
4664     "B", "Jail may alter system file flags");
4665 SYSCTL_JAIL_PARAM(_allow, quotas, CTLTYPE_INT | CTLFLAG_RW,
4666     "B", "Jail may set file quotas");
4667 SYSCTL_JAIL_PARAM(_allow, socket_af, CTLTYPE_INT | CTLFLAG_RW,
4668     "B", "Jail may create sockets other than just UNIX/IPv4/IPv6/route");
4669 SYSCTL_JAIL_PARAM(_allow, mlock, CTLTYPE_INT | CTLFLAG_RW,
4670     "B", "Jail may lock (unlock) physical pages in memory");
4671 SYSCTL_JAIL_PARAM(_allow, reserved_ports, CTLTYPE_INT | CTLFLAG_RW,
4672     "B", "Jail may bind sockets to reserved ports");
4673 SYSCTL_JAIL_PARAM(_allow, read_msgbuf, CTLTYPE_INT | CTLFLAG_RW,
4674     "B", "Jail may read the kernel message buffer");
4675 SYSCTL_JAIL_PARAM(_allow, unprivileged_proc_debug, CTLTYPE_INT | CTLFLAG_RW,
4676     "B", "Unprivileged processes may use process debugging facilities");
4677 SYSCTL_JAIL_PARAM(_allow, suser, CTLTYPE_INT | CTLFLAG_RW,
4678     "B", "Processes in jail with uid 0 have privilege");
4679 #ifdef VIMAGE
4680 SYSCTL_JAIL_PARAM(_allow, nfsd, CTLTYPE_INT | CTLFLAG_RW,
4681     "B", "Mountd/nfsd may run in the jail");
4682 #endif
4683 SYSCTL_JAIL_PARAM(_allow, extattr, CTLTYPE_INT | CTLFLAG_RW,
4684     "B", "Jail may set system-level filesystem extended attributes");
4685 SYSCTL_JAIL_PARAM(_allow, adjtime, CTLTYPE_INT | CTLFLAG_RW,
4686     "B", "Jail may adjust system time");
4687 SYSCTL_JAIL_PARAM(_allow, settime, CTLTYPE_INT | CTLFLAG_RW,
4688     "B", "Jail may set system time");
4689 
4690 SYSCTL_JAIL_PARAM_SUBNODE(allow, mount, "Jail mount/unmount permission flags");
4691 SYSCTL_JAIL_PARAM(_allow_mount, , CTLTYPE_INT | CTLFLAG_RW,
4692     "B", "Jail may mount/unmount jail-friendly file systems in general");
4693 
4694 /*
4695  * Add a dynamic parameter allow.<name>, or allow.<prefix>.<name>.  Return
4696  * its associated bit in the pr_allow bitmask, or zero if the parameter was
4697  * not created.
4698  */
4699 unsigned
prison_add_allow(const char * prefix,const char * name,const char * prefix_descr,const char * descr)4700 prison_add_allow(const char *prefix, const char *name, const char *prefix_descr,
4701     const char *descr)
4702 {
4703 	struct bool_flags *bf;
4704 	struct sysctl_oid *parent;
4705 	char *allow_name, *allow_noname, *allowed;
4706 #ifndef NO_SYSCTL_DESCR
4707 	char *descr_deprecated;
4708 #endif
4709 	u_int allow_flag;
4710 
4711 	if (prefix
4712 	    ? asprintf(&allow_name, M_PRISON, "allow.%s.%s", prefix, name)
4713 		< 0 ||
4714 	      asprintf(&allow_noname, M_PRISON, "allow.%s.no%s", prefix, name)
4715 		< 0
4716 	    : asprintf(&allow_name, M_PRISON, "allow.%s", name) < 0 ||
4717 	      asprintf(&allow_noname, M_PRISON, "allow.no%s", name) < 0) {
4718 		free(allow_name, M_PRISON);
4719 		return 0;
4720 	}
4721 
4722 	/*
4723 	 * See if this parameter has already beed added, i.e. a module was
4724 	 * previously loaded/unloaded.
4725 	 */
4726 	mtx_lock(&prison0.pr_mtx);
4727 	for (bf = pr_flag_allow;
4728 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
4729 		atomic_load_int(&bf->flag) != 0;
4730 	     bf++) {
4731 		if (strcmp(bf->name, allow_name) == 0) {
4732 			allow_flag = bf->flag;
4733 			goto no_add;
4734 		}
4735 	}
4736 
4737 	/*
4738 	 * Find a free bit in pr_allow_all, failing if there are none
4739 	 * (which shouldn't happen as long as we keep track of how many
4740 	 * potential dynamic flags exist).
4741 	 */
4742 	for (allow_flag = 1;; allow_flag <<= 1) {
4743 		if (allow_flag == 0)
4744 			goto no_add;
4745 		if ((pr_allow_all & allow_flag) == 0)
4746 			break;
4747 	}
4748 
4749 	/* Note the parameter in the next open slot in pr_flag_allow. */
4750 	for (bf = pr_flag_allow; ; bf++) {
4751 		if (bf == pr_flag_allow + nitems(pr_flag_allow)) {
4752 			/* This should never happen, but is not fatal. */
4753 			allow_flag = 0;
4754 			goto no_add;
4755 		}
4756 		if (atomic_load_int(&bf->flag) == 0)
4757 			break;
4758 	}
4759 	bf->name = allow_name;
4760 	bf->noname = allow_noname;
4761 	pr_allow_all |= allow_flag;
4762 	/*
4763 	 * prison0 always has permission for the new parameter.
4764 	 * Other jails must have it granted to them.
4765 	 */
4766 	prison0.pr_allow |= allow_flag;
4767 	/* The flag indicates a valid entry, so make sure it is set last. */
4768 	atomic_store_rel_int(&bf->flag, allow_flag);
4769 	mtx_unlock(&prison0.pr_mtx);
4770 
4771 	/*
4772 	 * Create sysctls for the parameter, and the back-compat global
4773 	 * permission.
4774 	 */
4775 	parent = prefix
4776 	    ? SYSCTL_ADD_NODE(NULL,
4777 		  SYSCTL_CHILDREN(&sysctl___security_jail_param_allow),
4778 		  OID_AUTO, prefix, CTLFLAG_MPSAFE, 0, prefix_descr)
4779 	    : &sysctl___security_jail_param_allow;
4780 	(void)SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(parent), OID_AUTO,
4781 	    name, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
4782 	    NULL, 0, sysctl_jail_param, "B", descr);
4783 	if ((prefix
4784 	     ? asprintf(&allowed, M_TEMP, "%s_%s_allowed", prefix, name)
4785 	     : asprintf(&allowed, M_TEMP, "%s_allowed", name)) >= 0) {
4786 #ifndef NO_SYSCTL_DESCR
4787 		(void)asprintf(&descr_deprecated, M_TEMP, "%s (deprecated)",
4788 		    descr);
4789 #endif
4790 		(void)SYSCTL_ADD_PROC(NULL,
4791 		    SYSCTL_CHILDREN(&sysctl___security_jail), OID_AUTO, allowed,
4792 		    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, allow_flag,
4793 		    sysctl_jail_default_allow, "I", descr_deprecated);
4794 #ifndef NO_SYSCTL_DESCR
4795 		free(descr_deprecated, M_TEMP);
4796 #endif
4797 		free(allowed, M_TEMP);
4798 	}
4799 	return allow_flag;
4800 
4801  no_add:
4802 	mtx_unlock(&prison0.pr_mtx);
4803 	free(allow_name, M_PRISON);
4804 	free(allow_noname, M_PRISON);
4805 	return allow_flag;
4806 }
4807 
4808 /*
4809  * The VFS system will register jail-aware filesystems here.  They each get
4810  * a parameter allow.mount.xxxfs and a flag to check when a jailed user
4811  * attempts to mount.
4812  */
4813 void
prison_add_vfs(struct vfsconf * vfsp)4814 prison_add_vfs(struct vfsconf *vfsp)
4815 {
4816 #ifdef NO_SYSCTL_DESCR
4817 
4818 	vfsp->vfc_prison_flag = prison_add_allow("mount", vfsp->vfc_name,
4819 	    NULL, NULL);
4820 #else
4821 	char *descr;
4822 
4823 	(void)asprintf(&descr, M_TEMP, "Jail may mount the %s file system",
4824 	    vfsp->vfc_name);
4825 	vfsp->vfc_prison_flag = prison_add_allow("mount", vfsp->vfc_name,
4826 	    NULL, descr);
4827 	free(descr, M_TEMP);
4828 #endif
4829 }
4830 
4831 #ifdef RACCT
4832 void
prison_racct_foreach(void (* callback)(struct racct * racct,void * arg2,void * arg3),void (* pre)(void),void (* post)(void),void * arg2,void * arg3)4833 prison_racct_foreach(void (*callback)(struct racct *racct,
4834     void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
4835     void *arg2, void *arg3)
4836 {
4837 	struct prison_racct *prr;
4838 
4839 	ASSERT_RACCT_ENABLED();
4840 
4841 	sx_slock(&allprison_lock);
4842 	if (pre != NULL)
4843 		(pre)();
4844 	LIST_FOREACH(prr, &allprison_racct, prr_next)
4845 		(callback)(prr->prr_racct, arg2, arg3);
4846 	if (post != NULL)
4847 		(post)();
4848 	sx_sunlock(&allprison_lock);
4849 }
4850 
4851 static struct prison_racct *
prison_racct_find_locked(const char * name)4852 prison_racct_find_locked(const char *name)
4853 {
4854 	struct prison_racct *prr;
4855 
4856 	ASSERT_RACCT_ENABLED();
4857 	sx_assert(&allprison_lock, SA_XLOCKED);
4858 
4859 	if (name[0] == '\0' || strlen(name) >= MAXHOSTNAMELEN)
4860 		return (NULL);
4861 
4862 	LIST_FOREACH(prr, &allprison_racct, prr_next) {
4863 		if (strcmp(name, prr->prr_name) != 0)
4864 			continue;
4865 
4866 		/* Found prison_racct with a matching name? */
4867 		prison_racct_hold(prr);
4868 		return (prr);
4869 	}
4870 
4871 	/* Add new prison_racct. */
4872 	prr = malloc(sizeof(*prr), M_PRISON_RACCT, M_ZERO | M_WAITOK);
4873 	racct_create(&prr->prr_racct);
4874 
4875 	strcpy(prr->prr_name, name);
4876 	refcount_init(&prr->prr_refcount, 1);
4877 	LIST_INSERT_HEAD(&allprison_racct, prr, prr_next);
4878 
4879 	return (prr);
4880 }
4881 
4882 struct prison_racct *
prison_racct_find(const char * name)4883 prison_racct_find(const char *name)
4884 {
4885 	struct prison_racct *prr;
4886 
4887 	ASSERT_RACCT_ENABLED();
4888 
4889 	sx_xlock(&allprison_lock);
4890 	prr = prison_racct_find_locked(name);
4891 	sx_xunlock(&allprison_lock);
4892 	return (prr);
4893 }
4894 
4895 void
prison_racct_hold(struct prison_racct * prr)4896 prison_racct_hold(struct prison_racct *prr)
4897 {
4898 
4899 	ASSERT_RACCT_ENABLED();
4900 
4901 	refcount_acquire(&prr->prr_refcount);
4902 }
4903 
4904 static void
prison_racct_free_locked(struct prison_racct * prr)4905 prison_racct_free_locked(struct prison_racct *prr)
4906 {
4907 
4908 	ASSERT_RACCT_ENABLED();
4909 	sx_assert(&allprison_lock, SA_XLOCKED);
4910 
4911 	if (refcount_release(&prr->prr_refcount)) {
4912 		racct_destroy(&prr->prr_racct);
4913 		LIST_REMOVE(prr, prr_next);
4914 		free(prr, M_PRISON_RACCT);
4915 	}
4916 }
4917 
4918 void
prison_racct_free(struct prison_racct * prr)4919 prison_racct_free(struct prison_racct *prr)
4920 {
4921 
4922 	ASSERT_RACCT_ENABLED();
4923 	sx_assert(&allprison_lock, SA_UNLOCKED);
4924 
4925 	if (refcount_release_if_not_last(&prr->prr_refcount))
4926 		return;
4927 
4928 	sx_xlock(&allprison_lock);
4929 	prison_racct_free_locked(prr);
4930 	sx_xunlock(&allprison_lock);
4931 }
4932 
4933 static void
prison_racct_attach(struct prison * pr)4934 prison_racct_attach(struct prison *pr)
4935 {
4936 	struct prison_racct *prr;
4937 
4938 	ASSERT_RACCT_ENABLED();
4939 	sx_assert(&allprison_lock, SA_XLOCKED);
4940 
4941 	prr = prison_racct_find_locked(pr->pr_name);
4942 	KASSERT(prr != NULL, ("cannot find prison_racct"));
4943 
4944 	pr->pr_prison_racct = prr;
4945 }
4946 
4947 /*
4948  * Handle jail renaming.  From the racct point of view, renaming means
4949  * moving from one prison_racct to another.
4950  */
4951 static void
prison_racct_modify(struct prison * pr)4952 prison_racct_modify(struct prison *pr)
4953 {
4954 #ifdef RCTL
4955 	struct proc *p;
4956 	struct ucred *cred;
4957 #endif
4958 	struct prison_racct *oldprr;
4959 
4960 	ASSERT_RACCT_ENABLED();
4961 
4962 	sx_slock(&allproc_lock);
4963 	sx_xlock(&allprison_lock);
4964 
4965 	if (strcmp(pr->pr_name, pr->pr_prison_racct->prr_name) == 0) {
4966 		sx_xunlock(&allprison_lock);
4967 		sx_sunlock(&allproc_lock);
4968 		return;
4969 	}
4970 
4971 	oldprr = pr->pr_prison_racct;
4972 	pr->pr_prison_racct = NULL;
4973 
4974 	prison_racct_attach(pr);
4975 
4976 	/*
4977 	 * Move resource utilisation records.
4978 	 */
4979 	racct_move(pr->pr_prison_racct->prr_racct, oldprr->prr_racct);
4980 
4981 #ifdef RCTL
4982 	/*
4983 	 * Force rctl to reattach rules to processes.
4984 	 */
4985 	FOREACH_PROC_IN_SYSTEM(p) {
4986 		PROC_LOCK(p);
4987 		cred = crhold(p->p_ucred);
4988 		PROC_UNLOCK(p);
4989 		rctl_proc_ucred_changed(p, cred);
4990 		crfree(cred);
4991 	}
4992 #endif
4993 
4994 	sx_sunlock(&allproc_lock);
4995 	prison_racct_free_locked(oldprr);
4996 	sx_xunlock(&allprison_lock);
4997 }
4998 
4999 static void
prison_racct_detach(struct prison * pr)5000 prison_racct_detach(struct prison *pr)
5001 {
5002 
5003 	ASSERT_RACCT_ENABLED();
5004 	sx_assert(&allprison_lock, SA_UNLOCKED);
5005 
5006 	if (pr->pr_prison_racct == NULL)
5007 		return;
5008 	prison_racct_free(pr->pr_prison_racct);
5009 	pr->pr_prison_racct = NULL;
5010 }
5011 #endif /* RACCT */
5012 
5013 #ifdef DDB
5014 
5015 static void
db_show_prison(struct prison * pr)5016 db_show_prison(struct prison *pr)
5017 {
5018 	struct bool_flags *bf;
5019 	struct jailsys_flags *jsf;
5020 #if defined(INET) || defined(INET6)
5021 	int ii;
5022 	struct prison_ip *pip;
5023 #endif
5024 	unsigned f;
5025 #ifdef INET
5026 	char ip4buf[INET_ADDRSTRLEN];
5027 #endif
5028 #ifdef INET6
5029 	char ip6buf[INET6_ADDRSTRLEN];
5030 #endif
5031 
5032 	db_printf("prison %p:\n", pr);
5033 	db_printf(" jid             = %d\n", pr->pr_id);
5034 	db_printf(" name            = %s\n", pr->pr_name);
5035 	db_printf(" parent          = %p\n", pr->pr_parent);
5036 	db_printf(" ref             = %d\n", pr->pr_ref);
5037 	db_printf(" uref            = %d\n", pr->pr_uref);
5038 	db_printf(" state           = %s\n",
5039 	    pr->pr_state == PRISON_STATE_ALIVE ? "alive" :
5040 	    pr->pr_state == PRISON_STATE_DYING ? "dying" :
5041 	    "invalid");
5042 	db_printf(" path            = %s\n", pr->pr_path);
5043 	db_printf(" cpuset          = %d\n", pr->pr_cpuset
5044 	    ? pr->pr_cpuset->cs_id : -1);
5045 #ifdef VIMAGE
5046 	db_printf(" vnet            = %p\n", pr->pr_vnet);
5047 #endif
5048 	db_printf(" root            = %p\n", pr->pr_root);
5049 	db_printf(" securelevel     = %d\n", pr->pr_securelevel);
5050 	db_printf(" devfs_rsnum     = %d\n", pr->pr_devfs_rsnum);
5051 	db_printf(" children.max    = %d\n", pr->pr_childmax);
5052 	db_printf(" children.cur    = %d\n", pr->pr_childcount);
5053 	db_printf(" child           = %p\n", LIST_FIRST(&pr->pr_children));
5054 	db_printf(" sibling         = %p\n", LIST_NEXT(pr, pr_sibling));
5055 	db_printf(" flags           = 0x%x", pr->pr_flags);
5056 	for (bf = pr_flag_bool; bf < pr_flag_bool + nitems(pr_flag_bool); bf++)
5057 		if (pr->pr_flags & bf->flag)
5058 			db_printf(" %s", bf->name);
5059 	for (jsf = pr_flag_jailsys;
5060 	     jsf < pr_flag_jailsys + nitems(pr_flag_jailsys);
5061 	     jsf++) {
5062 		f = pr->pr_flags & (jsf->disable | jsf->new);
5063 		db_printf(" %-16s= %s\n", jsf->name,
5064 		    (f != 0 && f == jsf->disable) ? "disable"
5065 		    : (f == jsf->new) ? "new"
5066 		    : "inherit");
5067 	}
5068 	db_printf(" allow           = 0x%x", pr->pr_allow);
5069 	for (bf = pr_flag_allow;
5070 	     bf < pr_flag_allow + nitems(pr_flag_allow) &&
5071 		atomic_load_int(&bf->flag) != 0;
5072 	     bf++)
5073 		if (pr->pr_allow & bf->flag)
5074 			db_printf(" %s", bf->name);
5075 	db_printf("\n");
5076 	db_printf(" enforce_statfs  = %d\n", pr->pr_enforce_statfs);
5077 	db_printf(" host.hostname   = %s\n", pr->pr_hostname);
5078 	db_printf(" host.domainname = %s\n", pr->pr_domainname);
5079 	db_printf(" host.hostuuid   = %s\n", pr->pr_hostuuid);
5080 	db_printf(" host.hostid     = %lu\n", pr->pr_hostid);
5081 #ifdef INET
5082 	if ((pip = pr->pr_addrs[PR_INET]) != NULL) {
5083 		db_printf(" ip4s            = %d\n", pip->ips);
5084 		for (ii = 0; ii < pip->ips; ii++)
5085 			db_printf(" %s %s\n",
5086 			    ii == 0 ? "ip4.addr        =" : "                 ",
5087 			    inet_ntoa_r(
5088 			    *(const struct in_addr *)PR_IP(pip, PR_INET, ii),
5089 			    ip4buf));
5090 	}
5091 #endif
5092 #ifdef INET6
5093 	if ((pip = pr->pr_addrs[PR_INET6]) != NULL) {
5094 		db_printf(" ip6s            = %d\n", pip->ips);
5095 		for (ii = 0; ii < pip->ips; ii++)
5096 			db_printf(" %s %s\n",
5097 			    ii == 0 ? "ip6.addr        =" : "                 ",
5098 			    ip6_sprintf(ip6buf,
5099 			    (const struct in6_addr *)PR_IP(pip, PR_INET6, ii)));
5100 	}
5101 #endif
5102 }
5103 
DB_SHOW_COMMAND(prison,db_show_prison_command)5104 DB_SHOW_COMMAND(prison, db_show_prison_command)
5105 {
5106 	struct prison *pr;
5107 
5108 	if (!have_addr) {
5109 		/*
5110 		 * Show all prisons in the list, and prison0 which is not
5111 		 * listed.
5112 		 */
5113 		db_show_prison(&prison0);
5114 		if (!db_pager_quit) {
5115 			TAILQ_FOREACH(pr, &allprison, pr_list) {
5116 				db_show_prison(pr);
5117 				if (db_pager_quit)
5118 					break;
5119 			}
5120 		}
5121 		return;
5122 	}
5123 
5124 	if (addr == 0)
5125 		pr = &prison0;
5126 	else {
5127 		/* Look for a prison with the ID and with references. */
5128 		TAILQ_FOREACH(pr, &allprison, pr_list)
5129 			if (pr->pr_id == addr && pr->pr_ref > 0)
5130 				break;
5131 		if (pr == NULL)
5132 			/* Look again, without requiring a reference. */
5133 			TAILQ_FOREACH(pr, &allprison, pr_list)
5134 				if (pr->pr_id == addr)
5135 					break;
5136 		if (pr == NULL)
5137 			/* Assume address points to a valid prison. */
5138 			pr = (struct prison *)addr;
5139 	}
5140 	db_show_prison(pr);
5141 }
5142 
5143 #endif /* DDB */
5144