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freebsd-skq/sys/kern/kern_jail.c
Jamie Gritton ca04ba6430 Don't allow creating a socket with a protocol family that the current 
jail doesn't support.  This involves a new function prison_check_af,
like prison_check_ip[46] but that checks only the family.

With this change, most of the errors generated by jailed sockets
shouldn't ever occur, at least until jails are changeable.

Approved by:	bz (mentor)
2009-02-05 14:15:18 +00:00

1652 lines
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/*-
* Copyright (c) 1999 Poul-Henning Kamp.
* Copyright (c) 2008 Bjoern A. Zeeb.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/sysproto.h>
#include <sys/malloc.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/taskqueue.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/namei.h>
#include <sys/mount.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <sys/vimage.h>
#include <sys/osd.h>
#include <net/if.h>
#include <netinet/in.h>
#ifdef DDB
#include <ddb/ddb.h>
#ifdef INET6
#include <netinet6/in6_var.h>
#endif /* INET6 */
#endif /* DDB */
#include <security/mac/mac_framework.h>
MALLOC_DEFINE(M_PRISON, "prison", "Prison structures");
SYSCTL_NODE(_security, OID_AUTO, jail, CTLFLAG_RW, 0,
"Jail rules");
int jail_set_hostname_allowed = 1;
SYSCTL_INT(_security_jail, OID_AUTO, set_hostname_allowed, CTLFLAG_RW,
&jail_set_hostname_allowed, 0,
"Processes in jail can set their hostnames");
int jail_socket_unixiproute_only = 1;
SYSCTL_INT(_security_jail, OID_AUTO, socket_unixiproute_only, CTLFLAG_RW,
&jail_socket_unixiproute_only, 0,
"Processes in jail are limited to creating UNIX/IP/route sockets only");
int jail_sysvipc_allowed = 0;
SYSCTL_INT(_security_jail, OID_AUTO, sysvipc_allowed, CTLFLAG_RW,
&jail_sysvipc_allowed, 0,
"Processes in jail can use System V IPC primitives");
static int jail_enforce_statfs = 2;
SYSCTL_INT(_security_jail, OID_AUTO, enforce_statfs, CTLFLAG_RW,
&jail_enforce_statfs, 0,
"Processes in jail cannot see all mounted file systems");
int jail_allow_raw_sockets = 0;
SYSCTL_INT(_security_jail, OID_AUTO, allow_raw_sockets, CTLFLAG_RW,
&jail_allow_raw_sockets, 0,
"Prison root can create raw sockets");
int jail_chflags_allowed = 0;
SYSCTL_INT(_security_jail, OID_AUTO, chflags_allowed, CTLFLAG_RW,
&jail_chflags_allowed, 0,
"Processes in jail can alter system file flags");
int jail_mount_allowed = 0;
SYSCTL_INT(_security_jail, OID_AUTO, mount_allowed, CTLFLAG_RW,
&jail_mount_allowed, 0,
"Processes in jail can mount/unmount jail-friendly file systems");
int jail_max_af_ips = 255;
SYSCTL_INT(_security_jail, OID_AUTO, jail_max_af_ips, CTLFLAG_RW,
&jail_max_af_ips, 0,
"Number of IP addresses a jail may have at most per address family");
/* allprison, lastprid, and prisoncount are protected by allprison_lock. */
struct prisonlist allprison;
struct sx allprison_lock;
int lastprid = 0;
int prisoncount = 0;
static void init_prison(void *);
static void prison_complete(void *context, int pending);
static int sysctl_jail_list(SYSCTL_HANDLER_ARGS);
#ifdef INET
static int _prison_check_ip4(struct prison *, struct in_addr *);
#endif
#ifdef INET6
static int _prison_check_ip6(struct prison *, struct in6_addr *);
#endif
static void
init_prison(void *data __unused)
{
sx_init(&allprison_lock, "allprison");
LIST_INIT(&allprison);
}
SYSINIT(prison, SI_SUB_INTRINSIC, SI_ORDER_ANY, init_prison, NULL);
#ifdef INET
static int
qcmp_v4(const void *ip1, const void *ip2)
{
in_addr_t iaa, iab;
/*
* We need to compare in HBO here to get the list sorted as expected
* by the result of the code. Sorting NBO addresses gives you
* interesting results. If you do not understand, do not try.
*/
iaa = ntohl(((const struct in_addr *)ip1)->s_addr);
iab = ntohl(((const struct in_addr *)ip2)->s_addr);
/*
* Do not simply return the difference of the two numbers, the int is
* not wide enough.
*/
if (iaa > iab)
return (1);
else if (iaa < iab)
return (-1);
else
return (0);
}
#endif
#ifdef INET6
static int
qcmp_v6(const void *ip1, const void *ip2)
{
const struct in6_addr *ia6a, *ia6b;
int i, rc;
ia6a = (const struct in6_addr *)ip1;
ia6b = (const struct in6_addr *)ip2;
rc = 0;
for (i=0; rc == 0 && i < sizeof(struct in6_addr); i++) {
if (ia6a->s6_addr[i] > ia6b->s6_addr[i])
rc = 1;
else if (ia6a->s6_addr[i] < ia6b->s6_addr[i])
rc = -1;
}
return (rc);
}
#endif
#if defined(INET) || defined(INET6)
static int
prison_check_conflicting_ips(struct prison *p)
{
struct prison *pr;
int i;
sx_assert(&allprison_lock, SX_LOCKED);
if (p->pr_ip4s == 0 && p->pr_ip6s == 0)
return (0);
LIST_FOREACH(pr, &allprison, pr_list) {
/*
* Skip 'dying' prisons to avoid problems when
* restarting multi-IP jails.
*/
if (pr->pr_state == PRISON_STATE_DYING)
continue;
/*
* We permit conflicting IPs if there is no
* more than 1 IP on eeach jail.
* In case there is one duplicate on a jail with
* more than one IP stop checking and return error.
*/
#ifdef INET
if ((p->pr_ip4s >= 1 && pr->pr_ip4s > 1) ||
(p->pr_ip4s > 1 && pr->pr_ip4s >= 1)) {
for (i = 0; i < p->pr_ip4s; i++) {
if (_prison_check_ip4(pr, &p->pr_ip4[i]) == 0)
return (EINVAL);
}
}
#endif
#ifdef INET6
if ((p->pr_ip6s >= 1 && pr->pr_ip6s > 1) ||
(p->pr_ip6s > 1 && pr->pr_ip6s >= 1)) {
for (i = 0; i < p->pr_ip6s; i++) {
if (_prison_check_ip6(pr, &p->pr_ip6[i]) == 0)
return (EINVAL);
}
}
#endif
}
return (0);
}
static int
jail_copyin_ips(struct jail *j)
{
#ifdef INET
struct in_addr *ip4;
#endif
#ifdef INET6
struct in6_addr *ip6;
#endif
int error, i;
/*
* Copy in addresses, check for duplicate addresses and do some
* simple 0 and broadcast checks. If users give other bogus addresses
* it is their problem.
*
* IP addresses are all sorted but ip[0] to preserve the primary IP
* address as given from userland. This special IP is used for
* unbound outgoing connections as well for "loopback" traffic.
*/
#ifdef INET
ip4 = NULL;
#endif
#ifdef INET6
ip6 = NULL;
#endif
#ifdef INET
if (j->ip4s > 0) {
ip4 = (struct in_addr *)malloc(j->ip4s * sizeof(struct in_addr),
M_PRISON, M_WAITOK | M_ZERO);
error = copyin(j->ip4, ip4, j->ip4s * sizeof(struct in_addr));
if (error)
goto e_free_ip;
/* Sort all but the first IPv4 address. */
if (j->ip4s > 1)
qsort((ip4 + 1), j->ip4s - 1,
sizeof(struct in_addr), qcmp_v4);
/*
* We do not have to care about byte order for these checks
* so we will do them in NBO.
*/
for (i=0; i<j->ip4s; i++) {
if (ip4[i].s_addr == htonl(INADDR_ANY) ||
ip4[i].s_addr == htonl(INADDR_BROADCAST)) {
error = EINVAL;
goto e_free_ip;
}
if ((i+1) < j->ip4s &&
(ip4[0].s_addr == ip4[i+1].s_addr ||
ip4[i].s_addr == ip4[i+1].s_addr)) {
error = EINVAL;
goto e_free_ip;
}
}
j->ip4 = ip4;
} else
j->ip4 = NULL;
#endif
#ifdef INET6
if (j->ip6s > 0) {
ip6 = (struct in6_addr *)malloc(j->ip6s * sizeof(struct in6_addr),
M_PRISON, M_WAITOK | M_ZERO);
error = copyin(j->ip6, ip6, j->ip6s * sizeof(struct in6_addr));
if (error)
goto e_free_ip;
/* Sort all but the first IPv6 address. */
if (j->ip6s > 1)
qsort((ip6 + 1), j->ip6s - 1,
sizeof(struct in6_addr), qcmp_v6);
for (i=0; i<j->ip6s; i++) {
if (IN6_IS_ADDR_UNSPECIFIED(&ip6[i])) {
error = EINVAL;
goto e_free_ip;
}
if ((i+1) < j->ip6s &&
(IN6_ARE_ADDR_EQUAL(&ip6[0], &ip6[i+1]) ||
IN6_ARE_ADDR_EQUAL(&ip6[i], &ip6[i+1]))) {
error = EINVAL;
goto e_free_ip;
}
}
j->ip6 = ip6;
} else
j->ip6 = NULL;
#endif
return (0);
e_free_ip:
#ifdef INET6
free(ip6, M_PRISON);
#endif
#ifdef INET
free(ip4, M_PRISON);
#endif
return (error);
}
#endif /* INET || INET6 */
static int
jail_handle_ips(struct jail *j)
{
#if defined(INET) || defined(INET6)
int error;
#endif
/*
* Finish conversion for older versions, copyin and setup IPs.
*/
switch (j->version) {
case 0:
{
#ifdef INET
/* FreeBSD single IPv4 jails. */
struct in_addr *ip4;
if (j->ip4s == INADDR_ANY || j->ip4s == INADDR_BROADCAST)
return (EINVAL);
ip4 = (struct in_addr *)malloc(sizeof(struct in_addr),
M_PRISON, M_WAITOK | M_ZERO);
/*
* Jail version 0 still used HBO for the IPv4 address.
*/
ip4->s_addr = htonl(j->ip4s);
j->ip4s = 1;
j->ip4 = ip4;
break;
#else
return (EINVAL);
#endif
}
case 1:
/*
* Version 1 was used by multi-IPv4 jail implementations
* that never made it into the official kernel.
* We should never hit this here; jail() should catch it.
*/
return (EINVAL);
case 2: /* JAIL_API_VERSION */
/* FreeBSD multi-IPv4/IPv6,noIP jails. */
#if defined(INET) || defined(INET6)
#ifdef INET
if (j->ip4s > jail_max_af_ips)
return (EINVAL);
#else
if (j->ip4s != 0)
return (EINVAL);
#endif
#ifdef INET6
if (j->ip6s > jail_max_af_ips)
return (EINVAL);
#else
if (j->ip6s != 0)
return (EINVAL);
#endif
error = jail_copyin_ips(j);
if (error)
return (error);
#endif
break;
default:
/* Sci-Fi jails are not supported, sorry. */
return (EINVAL);
}
return (0);
}
/*
* struct jail_args {
* struct jail *jail;
* };
*/
int
jail(struct thread *td, struct jail_args *uap)
{
uint32_t version;
int error;
struct jail j;
error = copyin(uap->jail, &version, sizeof(uint32_t));
if (error)
return (error);
switch (version) {
case 0:
/* FreeBSD single IPv4 jails. */
{
struct jail_v0 j0;
bzero(&j, sizeof(struct jail));
error = copyin(uap->jail, &j0, sizeof(struct jail_v0));
if (error)
return (error);
j.version = j0.version;
j.path = j0.path;
j.hostname = j0.hostname;
j.ip4s = j0.ip_number;
break;
}
case 1:
/*
* Version 1 was used by multi-IPv4 jail implementations
* that never made it into the official kernel.
*/
return (EINVAL);
case 2: /* JAIL_API_VERSION */
/* FreeBSD multi-IPv4/IPv6,noIP jails. */
error = copyin(uap->jail, &j, sizeof(struct jail));
if (error)
return (error);
break;
default:
/* Sci-Fi jails are not supported, sorry. */
return (EINVAL);
}
return (kern_jail(td, &j));
}
int
kern_jail(struct thread *td, struct jail *j)
{
struct nameidata nd;
struct prison *pr, *tpr;
struct jail_attach_args jaa;
int vfslocked, error, tryprid;
KASSERT(j != NULL, ("%s: j is NULL", __func__));
/* Handle addresses - convert old structs, copyin, check IPs. */
error = jail_handle_ips(j);
if (error)
return (error);
/* Allocate struct prison and fill it with life. */
pr = malloc(sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO);
mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF);
pr->pr_ref = 1;
error = copyinstr(j->path, &pr->pr_path, sizeof(pr->pr_path), NULL);
if (error)
goto e_killmtx;
NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE,
pr->pr_path, td);
error = namei(&nd);
if (error)
goto e_killmtx;
vfslocked = NDHASGIANT(&nd);
pr->pr_root = nd.ni_vp;
VOP_UNLOCK(nd.ni_vp, 0);
NDFREE(&nd, NDF_ONLY_PNBUF);
VFS_UNLOCK_GIANT(vfslocked);
error = copyinstr(j->hostname, &pr->pr_host, sizeof(pr->pr_host), NULL);
if (error)
goto e_dropvnref;
if (j->jailname != NULL) {
error = copyinstr(j->jailname, &pr->pr_name,
sizeof(pr->pr_name), NULL);
if (error)
goto e_dropvnref;
}
if (j->ip4s > 0) {
pr->pr_ip4 = j->ip4;
pr->pr_ip4s = j->ip4s;
}
#ifdef INET6
if (j->ip6s > 0) {
pr->pr_ip6 = j->ip6;
pr->pr_ip6s = j->ip6s;
}
#endif
pr->pr_linux = NULL;
pr->pr_securelevel = securelevel;
bzero(&pr->pr_osd, sizeof(pr->pr_osd));
/*
* Pre-set prison state to ALIVE upon cration. This is needed so we
* can later attach the process to it, etc (avoiding another extra
* state for ther process of creation, complicating things).
*/
pr->pr_state = PRISON_STATE_ALIVE;
/* Allocate a dedicated cpuset for each jail. */
error = cpuset_create_root(td, &pr->pr_cpuset);
if (error)
goto e_dropvnref;
sx_xlock(&allprison_lock);
/* Make sure we cannot run into problems with ambiguous bind()ings. */
#if defined(INET) || defined(INET6)
error = prison_check_conflicting_ips(pr);
if (error) {
sx_xunlock(&allprison_lock);
goto e_dropcpuset;
}
#endif
/* Determine next pr_id and add prison to allprison list. */
tryprid = lastprid + 1;
if (tryprid == JAIL_MAX)
tryprid = 1;
next:
LIST_FOREACH(tpr, &allprison, pr_list) {
if (tpr->pr_id == tryprid) {
tryprid++;
if (tryprid == JAIL_MAX) {
sx_xunlock(&allprison_lock);
error = EAGAIN;
goto e_dropcpuset;
}
goto next;
}
}
pr->pr_id = jaa.jid = lastprid = tryprid;
LIST_INSERT_HEAD(&allprison, pr, pr_list);
prisoncount++;
sx_xunlock(&allprison_lock);
error = jail_attach(td, &jaa);
if (error)
goto e_dropprref;
mtx_lock(&pr->pr_mtx);
pr->pr_ref--;
mtx_unlock(&pr->pr_mtx);
td->td_retval[0] = jaa.jid;
return (0);
e_dropprref:
sx_xlock(&allprison_lock);
LIST_REMOVE(pr, pr_list);
prisoncount--;
sx_xunlock(&allprison_lock);
e_dropcpuset:
cpuset_rel(pr->pr_cpuset);
e_dropvnref:
vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
vrele(pr->pr_root);
VFS_UNLOCK_GIANT(vfslocked);
e_killmtx:
mtx_destroy(&pr->pr_mtx);
free(pr, M_PRISON);
#ifdef INET6
free(j->ip6, M_PRISON);
#endif
#ifdef INET
free(j->ip4, M_PRISON);
#endif
return (error);
}
/*
* struct jail_attach_args {
* int jid;
* };
*/
int
jail_attach(struct thread *td, struct jail_attach_args *uap)
{
struct proc *p;
struct ucred *newcred, *oldcred;
struct prison *pr;
int vfslocked, error;
/*
* XXX: Note that there is a slight race here if two threads
* in the same privileged process attempt to attach to two
* different jails at the same time. It is important for
* user processes not to do this, or they might end up with
* a process root from one prison, but attached to the jail
* of another.
*/
error = priv_check(td, PRIV_JAIL_ATTACH);
if (error)
return (error);
p = td->td_proc;
sx_slock(&allprison_lock);
pr = prison_find(uap->jid);
if (pr == NULL) {
sx_sunlock(&allprison_lock);
return (EINVAL);
}
/*
* Do not allow a process to attach to a prison that is not
* considered to be "ALIVE".
*/
if (pr->pr_state != PRISON_STATE_ALIVE) {
mtx_unlock(&pr->pr_mtx);
sx_sunlock(&allprison_lock);
return (EINVAL);
}
pr->pr_ref++;
mtx_unlock(&pr->pr_mtx);
sx_sunlock(&allprison_lock);
/*
* Reparent the newly attached process to this jail.
*/
error = cpuset_setproc_update_set(p, pr->pr_cpuset);
if (error)
goto e_unref;
vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
vn_lock(pr->pr_root, LK_EXCLUSIVE | LK_RETRY);
if ((error = change_dir(pr->pr_root, td)) != 0)
goto e_unlock;
#ifdef MAC
if ((error = mac_vnode_check_chroot(td->td_ucred, pr->pr_root)))
goto e_unlock;
#endif
VOP_UNLOCK(pr->pr_root, 0);
change_root(pr->pr_root, td);
VFS_UNLOCK_GIANT(vfslocked);
newcred = crget();
PROC_LOCK(p);
oldcred = p->p_ucred;
setsugid(p);
crcopy(newcred, oldcred);
newcred->cr_prison = pr;
p->p_ucred = newcred;
prison_proc_hold(pr);
PROC_UNLOCK(p);
crfree(oldcred);
return (0);
e_unlock:
VOP_UNLOCK(pr->pr_root, 0);
VFS_UNLOCK_GIANT(vfslocked);
e_unref:
mtx_lock(&pr->pr_mtx);
pr->pr_ref--;
mtx_unlock(&pr->pr_mtx);
return (error);
}
/*
* Returns a locked prison instance, or NULL on failure.
*/
struct prison *
prison_find(int prid)
{
struct prison *pr;
sx_assert(&allprison_lock, SX_LOCKED);
LIST_FOREACH(pr, &allprison, pr_list) {
if (pr->pr_id == prid) {
mtx_lock(&pr->pr_mtx);
if (pr->pr_ref == 0) {
mtx_unlock(&pr->pr_mtx);
break;
}
return (pr);
}
}
return (NULL);
}
void
prison_free_locked(struct prison *pr)
{
mtx_assert(&pr->pr_mtx, MA_OWNED);
pr->pr_ref--;
if (pr->pr_ref == 0) {
mtx_unlock(&pr->pr_mtx);
TASK_INIT(&pr->pr_task, 0, prison_complete, pr);
taskqueue_enqueue(taskqueue_thread, &pr->pr_task);
return;
}
mtx_unlock(&pr->pr_mtx);
}
void
prison_free(struct prison *pr)
{
mtx_lock(&pr->pr_mtx);
prison_free_locked(pr);
}
static void
prison_complete(void *context, int pending)
{
struct prison *pr;
int vfslocked;
pr = (struct prison *)context;
sx_xlock(&allprison_lock);
LIST_REMOVE(pr, pr_list);
prisoncount--;
sx_xunlock(&allprison_lock);
cpuset_rel(pr->pr_cpuset);
/* Free all OSD associated to this jail. */
osd_jail_exit(pr);
vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount);
vrele(pr->pr_root);
VFS_UNLOCK_GIANT(vfslocked);
mtx_destroy(&pr->pr_mtx);
free(pr->pr_linux, M_PRISON);
#ifdef INET6
free(pr->pr_ip6, M_PRISON);
#endif
#ifdef INET
free(pr->pr_ip4, M_PRISON);
#endif
free(pr, M_PRISON);
}
void
prison_hold_locked(struct prison *pr)
{
mtx_assert(&pr->pr_mtx, MA_OWNED);
KASSERT(pr->pr_ref > 0,
("Trying to hold dead prison (id=%d).", pr->pr_id));
pr->pr_ref++;
}
void
prison_hold(struct prison *pr)
{
mtx_lock(&pr->pr_mtx);
prison_hold_locked(pr);
mtx_unlock(&pr->pr_mtx);
}
void
prison_proc_hold(struct prison *pr)
{
mtx_lock(&pr->pr_mtx);
KASSERT(pr->pr_state == PRISON_STATE_ALIVE,
("Cannot add a process to a non-alive prison (id=%d).", pr->pr_id));
pr->pr_nprocs++;
mtx_unlock(&pr->pr_mtx);
}
void
prison_proc_free(struct prison *pr)
{
mtx_lock(&pr->pr_mtx);
KASSERT(pr->pr_state == PRISON_STATE_ALIVE && pr->pr_nprocs > 0,
("Trying to kill a process in a dead prison (id=%d).", pr->pr_id));
pr->pr_nprocs--;
if (pr->pr_nprocs == 0)
pr->pr_state = PRISON_STATE_DYING;
mtx_unlock(&pr->pr_mtx);
}
#ifdef INET
/*
* Pass back primary IPv4 address of this jail.
*
* If not jailed return success but do not alter the address. Caller has to
* make sure to intialize it correctly (e.g. INADDR_ANY).
*
* Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
* Address returned in NBO.
*/
int
prison_get_ip4(struct ucred *cred, struct in_addr *ia)
{
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
if (!jailed(cred))
/* Do not change address passed in. */
return (0);
if (cred->cr_prison->pr_ip4 == NULL)
return (EAFNOSUPPORT);
ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr;
return (0);
}
/*
* Make sure our (source) address is set to something meaningful to this
* jail.
*
* Returns 0 if not jailed or if address belongs to jail, EADDRNOTAVAIL if
* the address doesn't belong, or EAFNOSUPPORT if the jail doesn't allow IPv4.
* Address passed in in NBO and returned in NBO.
*/
int
prison_local_ip4(struct ucred *cred, struct in_addr *ia)
{
struct in_addr ia0;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
if (!jailed(cred))
return (0);
if (cred->cr_prison->pr_ip4 == NULL)
return (EAFNOSUPPORT);
ia0.s_addr = ntohl(ia->s_addr);
if (ia0.s_addr == INADDR_LOOPBACK) {
ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr;
return (0);
}
if (ia0.s_addr == INADDR_ANY) {
/*
* In case there is only 1 IPv4 address, bind directly.
*/
if (cred->cr_prison->pr_ip4s == 1)
ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr;
return (0);
}
return (_prison_check_ip4(cred->cr_prison, ia));
}
/*
* Rewrite destination address in case we will connect to loopback address.
*
* Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4.
* Address passed in in NBO and returned in NBO.
*/
int
prison_remote_ip4(struct ucred *cred, struct in_addr *ia)
{
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
if (!jailed(cred))
return (0);
if (cred->cr_prison->pr_ip4 == NULL)
return (EAFNOSUPPORT);
if (ntohl(ia->s_addr) == INADDR_LOOPBACK) {
ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr;
return (0);
}
/*
* Return success because nothing had to be changed.
*/
return (0);
}
/*
* Check if given address belongs to the jail referenced by cred/prison.
*
* Returns 0 if not jailed or if address belongs to jail, EADDRNOTAVAIL if
* the address doesn't belong, or EAFNOSUPPORT if the jail doesn't allow IPv4.
* Address passed in in NBO.
*/
static int
_prison_check_ip4(struct prison *pr, struct in_addr *ia)
{
int i, a, z, d;
/*
* Check the primary IP.
*/
if (pr->pr_ip4[0].s_addr == ia->s_addr)
return (0);
/*
* All the other IPs are sorted so we can do a binary search.
*/
a = 0;
z = pr->pr_ip4s - 2;
while (a <= z) {
i = (a + z) / 2;
d = qcmp_v4(&pr->pr_ip4[i+1], ia);
if (d > 0)
z = i - 1;
else if (d < 0)
a = i + 1;
else
return (0);
}
return (EADDRNOTAVAIL);
}
int
prison_check_ip4(struct ucred *cred, struct in_addr *ia)
{
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia != NULL, ("%s: ia is NULL", __func__));
if (!jailed(cred))
return (0);
if (cred->cr_prison->pr_ip4 == NULL)
return (EAFNOSUPPORT);
return (_prison_check_ip4(cred->cr_prison, ia));
}
#endif
#ifdef INET6
/*
* Pass back primary IPv6 address for this jail.
*
* If not jailed return success but do not alter the address. Caller has to
* make sure to intialize it correctly (e.g. IN6ADDR_ANY_INIT).
*
* Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv6.
*/
int
prison_get_ip6(struct ucred *cred, struct in6_addr *ia6)
{
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
if (!jailed(cred))
return (0);
if (cred->cr_prison->pr_ip6 == NULL)
return (EAFNOSUPPORT);
bcopy(&cred->cr_prison->pr_ip6[0], ia6, sizeof(struct in6_addr));
return (0);
}
/*
* Make sure our (source) address is set to something meaningful to this jail.
*
* v6only should be set based on (inp->inp_flags & IN6P_IPV6_V6ONLY != 0)
* when needed while binding.
*
* Returns 0 if not jailed or if address belongs to jail, EADDRNOTAVAIL if
* the address doesn't belong, or EAFNOSUPPORT if the jail doesn't allow IPv6.
*/
int
prison_local_ip6(struct ucred *cred, struct in6_addr *ia6, int v6only)
{
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
if (!jailed(cred))
return (0);
if (cred->cr_prison->pr_ip6 == NULL)
return (EAFNOSUPPORT);
if (IN6_IS_ADDR_LOOPBACK(ia6)) {
bcopy(&cred->cr_prison->pr_ip6[0], ia6,
sizeof(struct in6_addr));
return (0);
}
if (IN6_IS_ADDR_UNSPECIFIED(ia6)) {
/*
* In case there is only 1 IPv6 address, and v6only is true,
* then bind directly.
*/
if (v6only != 0 && cred->cr_prison->pr_ip6s == 1)
bcopy(&cred->cr_prison->pr_ip6[0], ia6,
sizeof(struct in6_addr));
return (0);
}
return (_prison_check_ip6(cred->cr_prison, ia6));
}
/*
* Rewrite destination address in case we will connect to loopback address.
*
* Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv6.
*/
int
prison_remote_ip6(struct ucred *cred, struct in6_addr *ia6)
{
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
if (!jailed(cred))
return (0);
if (cred->cr_prison->pr_ip6 == NULL)
return (EAFNOSUPPORT);
if (IN6_IS_ADDR_LOOPBACK(ia6)) {
bcopy(&cred->cr_prison->pr_ip6[0], ia6,
sizeof(struct in6_addr));
return (0);
}
/*
* Return success because nothing had to be changed.
*/
return (0);
}
/*
* Check if given address belongs to the jail referenced by cred/prison.
*
* Returns 0 if not jailed or if address belongs to jail, EADDRNOTAVAIL if
* the address doesn't belong, or EAFNOSUPPORT if the jail doesn't allow IPv6.
*/
static int
_prison_check_ip6(struct prison *pr, struct in6_addr *ia6)
{
int i, a, z, d;
/*
* Check the primary IP.
*/
if (IN6_ARE_ADDR_EQUAL(&pr->pr_ip6[0], ia6))
return (0);
/*
* All the other IPs are sorted so we can do a binary search.
*/
a = 0;
z = pr->pr_ip6s - 2;
while (a <= z) {
i = (a + z) / 2;
d = qcmp_v6(&pr->pr_ip6[i+1], ia6);
if (d > 0)
z = i - 1;
else if (d < 0)
a = i + 1;
else
return (0);
}
return (EADDRNOTAVAIL);
}
int
prison_check_ip6(struct ucred *cred, struct in6_addr *ia6)
{
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
if (!jailed(cred))
return (0);
if (cred->cr_prison->pr_ip6 == NULL)
return (EAFNOSUPPORT);
return (_prison_check_ip6(cred->cr_prison, ia6));
}
#endif
/*
* Check if a jail supports the given address family.
*
* Returns 0 if not jailed or the address family is supported, EAFNOSUPPORT
* if not.
*/
int
prison_check_af(struct ucred *cred, int af)
{
int error;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
if (!jailed(cred))
return (0);
error = 0;
switch (af)
{
#ifdef INET
case AF_INET:
if (cred->cr_prison->pr_ip4 == NULL)
error = EAFNOSUPPORT;
break;
#endif
#ifdef INET6
case AF_INET6:
if (cred->cr_prison->pr_ip6 == NULL)
error = EAFNOSUPPORT;
break;
#endif
case AF_LOCAL:
case AF_ROUTE:
break;
default:
if (jail_socket_unixiproute_only)
error = EAFNOSUPPORT;
}
return (error);
}
/*
* Check if given address belongs to the jail referenced by cred (wrapper to
* prison_check_ip[46]).
*
* Returns 0 if not jailed or if address belongs to jail, EADDRNOTAVAIL if
* the address doesn't belong, or EAFNOSUPPORT if the jail doesn't allow
* the address family. IPv4 Address passed in in NBO.
*/
int
prison_if(struct ucred *cred, struct sockaddr *sa)
{
#ifdef INET
struct sockaddr_in *sai;
#endif
#ifdef INET6
struct sockaddr_in6 *sai6;
#endif
int error;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(sa != NULL, ("%s: sa is NULL", __func__));
error = 0;
switch (sa->sa_family)
{
#ifdef INET
case AF_INET:
sai = (struct sockaddr_in *)sa;
error = prison_check_ip4(cred, &sai->sin_addr);
break;
#endif
#ifdef INET6
case AF_INET6:
sai6 = (struct sockaddr_in6 *)sa;
error = prison_check_ip6(cred, &sai6->sin6_addr);
break;
#endif
default:
if (jailed(cred) && jail_socket_unixiproute_only)
error = EAFNOSUPPORT;
}
return (error);
}
/*
* Return 0 if jails permit p1 to frob p2, otherwise ESRCH.
*/
int
prison_check(struct ucred *cred1, struct ucred *cred2)
{
if (jailed(cred1)) {
if (!jailed(cred2))
return (ESRCH);
if (cred2->cr_prison != cred1->cr_prison)
return (ESRCH);
}
return (0);
}
/*
* Return 1 if the passed credential is in a jail, otherwise 0.
*/
int
jailed(struct ucred *cred)
{
return (cred->cr_prison != NULL);
}
/*
* Return the correct hostname for the passed credential.
*/
void
getcredhostname(struct ucred *cred, char *buf, size_t size)
{
INIT_VPROCG(cred->cr_vimage->v_procg);
if (jailed(cred)) {
mtx_lock(&cred->cr_prison->pr_mtx);
strlcpy(buf, cred->cr_prison->pr_host, size);
mtx_unlock(&cred->cr_prison->pr_mtx);
} else {
mtx_lock(&hostname_mtx);
strlcpy(buf, V_hostname, size);
mtx_unlock(&hostname_mtx);
}
}
/*
* Determine whether the subject represented by cred can "see"
* status of a mount point.
* Returns: 0 for permitted, ENOENT otherwise.
* XXX: This function should be called cr_canseemount() and should be
* placed in kern_prot.c.
*/
int
prison_canseemount(struct ucred *cred, struct mount *mp)
{
struct prison *pr;
struct statfs *sp;
size_t len;
if (!jailed(cred) || jail_enforce_statfs == 0)
return (0);
pr = cred->cr_prison;
if (pr->pr_root->v_mount == mp)
return (0);
if (jail_enforce_statfs == 2)
return (ENOENT);
/*
* If jail's chroot directory is set to "/" we should be able to see
* all mount-points from inside a jail.
* This is ugly check, but this is the only situation when jail's
* directory ends with '/'.
*/
if (strcmp(pr->pr_path, "/") == 0)
return (0);
len = strlen(pr->pr_path);
sp = &mp->mnt_stat;
if (strncmp(pr->pr_path, sp->f_mntonname, len) != 0)
return (ENOENT);
/*
* Be sure that we don't have situation where jail's root directory
* is "/some/path" and mount point is "/some/pathpath".
*/
if (sp->f_mntonname[len] != '\0' && sp->f_mntonname[len] != '/')
return (ENOENT);
return (0);
}
void
prison_enforce_statfs(struct ucred *cred, struct mount *mp, struct statfs *sp)
{
char jpath[MAXPATHLEN];
struct prison *pr;
size_t len;
if (!jailed(cred) || jail_enforce_statfs == 0)
return;
pr = cred->cr_prison;
if (prison_canseemount(cred, mp) != 0) {
bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
strlcpy(sp->f_mntonname, "[restricted]",
sizeof(sp->f_mntonname));
return;
}
if (pr->pr_root->v_mount == mp) {
/*
* Clear current buffer data, so we are sure nothing from
* the valid path left there.
*/
bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
*sp->f_mntonname = '/';
return;
}
/*
* If jail's chroot directory is set to "/" we should be able to see
* all mount-points from inside a jail.
*/
if (strcmp(pr->pr_path, "/") == 0)
return;
len = strlen(pr->pr_path);
strlcpy(jpath, sp->f_mntonname + len, sizeof(jpath));
/*
* Clear current buffer data, so we are sure nothing from
* the valid path left there.
*/
bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
if (*jpath == '\0') {
/* Should never happen. */
*sp->f_mntonname = '/';
} else {
strlcpy(sp->f_mntonname, jpath, sizeof(sp->f_mntonname));
}
}
/*
* Check with permission for a specific privilege is granted within jail. We
* have a specific list of accepted privileges; the rest are denied.
*/
int
prison_priv_check(struct ucred *cred, int priv)
{
if (!jailed(cred))
return (0);
switch (priv) {
/*
* Allow ktrace privileges for root in jail.
*/
case PRIV_KTRACE:
#if 0
/*
* Allow jailed processes to configure audit identity and
* submit audit records (login, etc). In the future we may
* want to further refine the relationship between audit and
* jail.
*/
case PRIV_AUDIT_GETAUDIT:
case PRIV_AUDIT_SETAUDIT:
case PRIV_AUDIT_SUBMIT:
#endif
/*
* Allow jailed processes to manipulate process UNIX
* credentials in any way they see fit.
*/
case PRIV_CRED_SETUID:
case PRIV_CRED_SETEUID:
case PRIV_CRED_SETGID:
case PRIV_CRED_SETEGID:
case PRIV_CRED_SETGROUPS:
case PRIV_CRED_SETREUID:
case PRIV_CRED_SETREGID:
case PRIV_CRED_SETRESUID:
case PRIV_CRED_SETRESGID:
/*
* Jail implements visibility constraints already, so allow
* jailed root to override uid/gid-based constraints.
*/
case PRIV_SEEOTHERGIDS:
case PRIV_SEEOTHERUIDS:
/*
* Jail implements inter-process debugging limits already, so
* allow jailed root various debugging privileges.
*/
case PRIV_DEBUG_DIFFCRED:
case PRIV_DEBUG_SUGID:
case PRIV_DEBUG_UNPRIV:
/*
* Allow jail to set various resource limits and login
* properties, and for now, exceed process resource limits.
*/
case PRIV_PROC_LIMIT:
case PRIV_PROC_SETLOGIN:
case PRIV_PROC_SETRLIMIT:
/*
* System V and POSIX IPC privileges are granted in jail.
*/
case PRIV_IPC_READ:
case PRIV_IPC_WRITE:
case PRIV_IPC_ADMIN:
case PRIV_IPC_MSGSIZE:
case PRIV_MQ_ADMIN:
/*
* Jail implements its own inter-process limits, so allow
* root processes in jail to change scheduling on other
* processes in the same jail. Likewise for signalling.
*/
case PRIV_SCHED_DIFFCRED:
case PRIV_SCHED_CPUSET:
case PRIV_SIGNAL_DIFFCRED:
case PRIV_SIGNAL_SUGID:
/*
* Allow jailed processes to write to sysctls marked as jail
* writable.
*/
case PRIV_SYSCTL_WRITEJAIL:
/*
* Allow root in jail to manage a variety of quota
* properties. These should likely be conditional on a
* configuration option.
*/
case PRIV_VFS_GETQUOTA:
case PRIV_VFS_SETQUOTA:
/*
* Since Jail relies on chroot() to implement file system
* protections, grant many VFS privileges to root in jail.
* Be careful to exclude mount-related and NFS-related
* privileges.
*/
case PRIV_VFS_READ:
case PRIV_VFS_WRITE:
case PRIV_VFS_ADMIN:
case PRIV_VFS_EXEC:
case PRIV_VFS_LOOKUP:
case PRIV_VFS_BLOCKRESERVE: /* XXXRW: Slightly surprising. */
case PRIV_VFS_CHFLAGS_DEV:
case PRIV_VFS_CHOWN:
case PRIV_VFS_CHROOT:
case PRIV_VFS_RETAINSUGID:
case PRIV_VFS_FCHROOT:
case PRIV_VFS_LINK:
case PRIV_VFS_SETGID:
case PRIV_VFS_STAT:
case PRIV_VFS_STICKYFILE:
return (0);
/*
* Depending on the global setting, allow privilege of
* setting system flags.
*/
case PRIV_VFS_SYSFLAGS:
if (jail_chflags_allowed)
return (0);
else
return (EPERM);
/*
* Depending on the global setting, allow privilege of
* mounting/unmounting file systems.
*/
case PRIV_VFS_MOUNT:
case PRIV_VFS_UNMOUNT:
case PRIV_VFS_MOUNT_NONUSER:
case PRIV_VFS_MOUNT_OWNER:
if (jail_mount_allowed)
return (0);
else
return (EPERM);
/*
* Allow jailed root to bind reserved ports and reuse in-use
* ports.
*/
case PRIV_NETINET_RESERVEDPORT:
case PRIV_NETINET_REUSEPORT:
return (0);
/*
* Allow jailed root to set certian IPv4/6 (option) headers.
*/
case PRIV_NETINET_SETHDROPTS:
return (0);
/*
* Conditionally allow creating raw sockets in jail.
*/
case PRIV_NETINET_RAW:
if (jail_allow_raw_sockets)
return (0);
else
return (EPERM);
/*
* Since jail implements its own visibility limits on netstat
* sysctls, allow getcred. This allows identd to work in
* jail.
*/
case PRIV_NETINET_GETCRED:
return (0);
default:
/*
* In all remaining cases, deny the privilege request. This
* includes almost all network privileges, many system
* configuration privileges.
*/
return (EPERM);
}
}
static int
sysctl_jail_list(SYSCTL_HANDLER_ARGS)
{
struct xprison *xp, *sxp;
struct prison *pr;
char *p;
size_t len;
int count, error;
if (jailed(req->td->td_ucred))
return (0);
sx_slock(&allprison_lock);
if ((count = prisoncount) == 0) {
sx_sunlock(&allprison_lock);
return (0);
}
len = sizeof(*xp) * count;
LIST_FOREACH(pr, &allprison, pr_list) {
#ifdef INET
len += pr->pr_ip4s * sizeof(struct in_addr);
#endif
#ifdef INET6
len += pr->pr_ip6s * sizeof(struct in6_addr);
#endif
}
sxp = xp = malloc(len, M_TEMP, M_WAITOK | M_ZERO);
LIST_FOREACH(pr, &allprison, pr_list) {
xp->pr_version = XPRISON_VERSION;
xp->pr_id = pr->pr_id;
xp->pr_state = pr->pr_state;
xp->pr_cpusetid = pr->pr_cpuset->cs_id;
strlcpy(xp->pr_path, pr->pr_path, sizeof(xp->pr_path));
mtx_lock(&pr->pr_mtx);
strlcpy(xp->pr_host, pr->pr_host, sizeof(xp->pr_host));
strlcpy(xp->pr_name, pr->pr_name, sizeof(xp->pr_name));
mtx_unlock(&pr->pr_mtx);
#ifdef INET
xp->pr_ip4s = pr->pr_ip4s;
#endif
#ifdef INET6
xp->pr_ip6s = pr->pr_ip6s;
#endif
p = (char *)(xp + 1);
#ifdef INET
if (pr->pr_ip4s > 0) {
bcopy(pr->pr_ip4, (struct in_addr *)p,
pr->pr_ip4s * sizeof(struct in_addr));
p += (pr->pr_ip4s * sizeof(struct in_addr));
}
#endif
#ifdef INET6
if (pr->pr_ip6s > 0) {
bcopy(pr->pr_ip6, (struct in6_addr *)p,
pr->pr_ip6s * sizeof(struct in6_addr));
p += (pr->pr_ip6s * sizeof(struct in6_addr));
}
#endif
xp = (struct xprison *)p;
}
sx_sunlock(&allprison_lock);
error = SYSCTL_OUT(req, sxp, len);
free(sxp, M_TEMP);
return (error);
}
SYSCTL_OID(_security_jail, OID_AUTO, list,
CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
sysctl_jail_list, "S", "List of active jails");
static int
sysctl_jail_jailed(SYSCTL_HANDLER_ARGS)
{
int error, injail;
injail = jailed(req->td->td_ucred);
error = SYSCTL_OUT(req, &injail, sizeof(injail));
return (error);
}
SYSCTL_PROC(_security_jail, OID_AUTO, jailed,
CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
sysctl_jail_jailed, "I", "Process in jail?");
#ifdef DDB
DB_SHOW_COMMAND(jails, db_show_jails)
{
struct prison *pr;
#ifdef INET
struct in_addr ia;
#endif
#ifdef INET6
char ip6buf[INET6_ADDRSTRLEN];
#endif
const char *state;
#if defined(INET) || defined(INET6)
int i;
#endif
db_printf(
" JID pr_ref pr_nprocs pr_ip4s pr_ip6s\n");
db_printf(
" Hostname Path\n");
db_printf(
" Name State\n");
db_printf(
" Cpusetid\n");
db_printf(
" IP Address(es)\n");
LIST_FOREACH(pr, &allprison, pr_list) {
db_printf("%6d %6d %9d %7d %7d\n",
pr->pr_id, pr->pr_ref, pr->pr_nprocs,
pr->pr_ip4s, pr->pr_ip6s);
db_printf("%6s %-29.29s %.74s\n",
"", pr->pr_host, pr->pr_path);
if (pr->pr_state < 0 || pr->pr_state >= (int)((sizeof(
prison_states) / sizeof(struct prison_state))))
state = "(bogus)";
else
state = prison_states[pr->pr_state].state_name;
db_printf("%6s %-29.29s %.74s\n",
"", (pr->pr_name[0] != '\0') ? pr->pr_name : "", state);
db_printf("%6s %-6d\n",
"", pr->pr_cpuset->cs_id);
#ifdef INET
for (i=0; i < pr->pr_ip4s; i++) {
ia.s_addr = pr->pr_ip4[i].s_addr;
db_printf("%6s %s\n", "", inet_ntoa(ia));
}
#endif
#ifdef INET6
for (i=0; i < pr->pr_ip6s; i++)
db_printf("%6s %s\n",
"", ip6_sprintf(ip6buf, &pr->pr_ip6[i]));
#endif /* INET6 */
if (db_pager_quit)
break;
}
}
#endif /* DDB */
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