freebsd-src/sys/netinet6/in6_jail.c
Gleb Smirnoff eb8dcdeac2 jail: network epoch protection for IP address lists
Now struct prison has two pointers (IPv4 and IPv6) of struct
prison_ip type.  Each points into epoch context, address count
and variable size array of addresses.  These structures are
freed with network epoch deferred free and are not edited in
place, instead a new structure is allocated and set.

While here, the change also generalizes a lot (but not enough)
of IPv4 and IPv6 processing. E.g. address family agnostic helpers
for kern_jail_set() are provided, that reduce v4-v6 copy-paste.

The fast-path prison_check_ip[46]_locked() is also generalized
into prison_ip_check() that can be executed with network epoch
protection only.

Reviewed by:		jamie
Differential revision:	https://reviews.freebsd.org/D33339
2021-12-26 10:45:50 -08:00

331 lines
8 KiB
C

/*-
* Copyright (c) 1999 Poul-Henning Kamp.
* Copyright (c) 2008 Bjoern A. Zeeb.
* Copyright (c) 2009 James Gritton.
* 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 <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/osd.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/racct.h>
#include <sys/refcount.h>
#include <sys/sx.h>
#include <sys/sysent.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 <net/if.h>
#include <net/vnet.h>
#include <netinet/in.h>
static void
prison_bcopy_primary_ip6(const struct prison *pr, struct in6_addr *ia6)
{
bcopy(prison_ip_get0(pr, PR_INET6), ia6, sizeof(struct in6_addr));
}
int
prison_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);
}
bool
prison_valid_v6(const void *ip)
{
const struct in6_addr *ia = ip;
return (!IN6_IS_ADDR_UNSPECIFIED(ia));
}
/*
* Pass back primary IPv6 address for this jail.
*
* If not restricted return success but do not alter the address. Caller has
* to make sure to initialize 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)
{
struct prison *pr;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
pr = cred->cr_prison;
if (!(pr->pr_flags & PR_IP6))
return (0);
mtx_lock(&pr->pr_mtx);
if (!(pr->pr_flags & PR_IP6)) {
mtx_unlock(&pr->pr_mtx);
return (0);
}
if (pr->pr_addrs[PR_INET6] == NULL) {
mtx_unlock(&pr->pr_mtx);
return (EAFNOSUPPORT);
}
prison_bcopy_primary_ip6(pr, ia6);
mtx_unlock(&pr->pr_mtx);
return (0);
}
/*
* Return 1 if we should do proper source address selection or are not jailed.
* We will return 0 if we should bypass source address selection in favour
* of the primary jail IPv6 address. Only in this case *ia will be updated and
* returned in NBO.
* Return EAFNOSUPPORT, in case this jail does not allow IPv6.
*/
int
prison_saddrsel_ip6(struct ucred *cred, struct in6_addr *ia6)
{
struct prison *pr;
struct in6_addr lia6;
int error;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
if (!jailed(cred))
return (1);
pr = cred->cr_prison;
if (pr->pr_flags & PR_IP6_SADDRSEL)
return (1);
lia6 = in6addr_any;
error = prison_get_ip6(cred, &lia6);
if (error)
return (error);
if (IN6_IS_ADDR_UNSPECIFIED(&lia6))
return (1);
bcopy(&lia6, ia6, sizeof(struct in6_addr));
return (0);
}
/*
* Return true if pr1 and pr2 have the same IPv6 address restrictions.
*/
int
prison_equal_ip6(struct prison *pr1, struct prison *pr2)
{
if (pr1 == pr2)
return (1);
while (pr1 != &prison0 &&
#ifdef VIMAGE
!(pr1->pr_flags & PR_VNET) &&
#endif
!(pr1->pr_flags & PR_IP6_USER))
pr1 = pr1->pr_parent;
while (pr2 != &prison0 &&
#ifdef VIMAGE
!(pr2->pr_flags & PR_VNET) &&
#endif
!(pr2->pr_flags & PR_IP6_USER))
pr2 = pr2->pr_parent;
return (pr1 == pr2);
}
/*
* 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 jail doesn't restrict IPv6 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)
{
struct prison *pr;
int error;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
pr = cred->cr_prison;
if (!(pr->pr_flags & PR_IP6))
return (0);
mtx_lock(&pr->pr_mtx);
if (!(pr->pr_flags & PR_IP6)) {
mtx_unlock(&pr->pr_mtx);
return (0);
}
if (pr->pr_addrs[PR_INET6] == NULL) {
mtx_unlock(&pr->pr_mtx);
return (EAFNOSUPPORT);
}
if (IN6_IS_ADDR_UNSPECIFIED(ia6)) {
/*
* In case there is only 1 IPv6 address, and v6only is true,
* then bind directly.
*/
if (v6only != 0 && prison_ip_cnt(pr, PR_INET6) == 1)
prison_bcopy_primary_ip6(pr, ia6);
mtx_unlock(&pr->pr_mtx);
return (0);
}
error = prison_check_ip6_locked(pr, ia6);
if (error == EADDRNOTAVAIL && IN6_IS_ADDR_LOOPBACK(ia6)) {
prison_bcopy_primary_ip6(pr, ia6);
error = 0;
}
mtx_unlock(&pr->pr_mtx);
return (error);
}
/*
* 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)
{
struct prison *pr;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
pr = cred->cr_prison;
if (!(pr->pr_flags & PR_IP6))
return (0);
mtx_lock(&pr->pr_mtx);
if (!(pr->pr_flags & PR_IP6)) {
mtx_unlock(&pr->pr_mtx);
return (0);
}
if (pr->pr_addrs[PR_INET6] == NULL) {
mtx_unlock(&pr->pr_mtx);
return (EAFNOSUPPORT);
}
if (IN6_IS_ADDR_LOOPBACK(ia6) &&
prison_check_ip6_locked(pr, ia6) == EADDRNOTAVAIL) {
prison_bcopy_primary_ip6(pr, ia6);
mtx_unlock(&pr->pr_mtx);
return (0);
}
/*
* Return success because nothing had to be changed.
*/
mtx_unlock(&pr->pr_mtx);
return (0);
}
/*
* Check if given address belongs to the jail referenced by cred/prison.
*
* Returns 0 if address belongs to jail,
* EADDRNOTAVAIL if the address doesn't belong to the jail.
*/
int
prison_check_ip6_locked(const struct prison *pr, const struct in6_addr *ia6)
{
if (!(pr->pr_flags & PR_IP6))
return (0);
return (prison_ip_check(pr, PR_INET6, ia6));
}
int
prison_check_ip6(const struct ucred *cred, const struct in6_addr *ia6)
{
struct prison *pr;
int error;
KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__));
pr = cred->cr_prison;
if (!(pr->pr_flags & PR_IP6))
return (0);
mtx_lock(&pr->pr_mtx);
if (!(pr->pr_flags & PR_IP6)) {
mtx_unlock(&pr->pr_mtx);
return (0);
}
if (pr->pr_addrs[PR_INET6] == NULL) {
mtx_unlock(&pr->pr_mtx);
return (EAFNOSUPPORT);
}
error = prison_check_ip6_locked(pr, ia6);
mtx_unlock(&pr->pr_mtx);
return (error);
}