freebsd-skq/sys/netinet6/in6_jail.c
smh 688581b7e7 Allow explicitly assigned IPv6 loopback address to be used in jails
If a jail has an explicitly assigned IPv6 loopback address then allow it
to be used instead of remapping requests for the loopback adddress to the
first IPv6 address assigned to the jail.

This fixes issues where applications attempt to detect their bound port
where they requested a loopback address, which was available, but instead
the kernel remapped it to the jails first address.

This is the same fix applied to IPv4 fix by: r316313

Also:
* Correct the description of prison_check_ip6_locked to match the code.

MFC after:	2 weeks
Relnotes:	Yes
Sponsored by:	Multiplay
2017-03-31 09:10:05 +00:00

419 lines
10 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_compat.h"
#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>
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);
}
int
prison_restrict_ip6(struct prison *pr, struct in6_addr *newip6)
{
int ii, ij, used;
struct prison *ppr;
ppr = pr->pr_parent;
if (!(pr->pr_flags & PR_IP6_USER)) {
/* This has no user settings, so just copy the parent's list. */
if (pr->pr_ip6s < ppr->pr_ip6s) {
/*
* There's no room for the parent's list. Use the
* new list buffer, which is assumed to be big enough
* (if it was passed). If there's no buffer, try to
* allocate one.
*/
used = 1;
if (newip6 == NULL) {
newip6 = malloc(ppr->pr_ip6s * sizeof(*newip6),
M_PRISON, M_NOWAIT);
if (newip6 != NULL)
used = 0;
}
if (newip6 != NULL) {
bcopy(ppr->pr_ip6, newip6,
ppr->pr_ip6s * sizeof(*newip6));
free(pr->pr_ip6, M_PRISON);
pr->pr_ip6 = newip6;
pr->pr_ip6s = ppr->pr_ip6s;
}
return (used);
}
pr->pr_ip6s = ppr->pr_ip6s;
if (pr->pr_ip6s > 0)
bcopy(ppr->pr_ip6, pr->pr_ip6,
pr->pr_ip6s * sizeof(*newip6));
else if (pr->pr_ip6 != NULL) {
free(pr->pr_ip6, M_PRISON);
pr->pr_ip6 = NULL;
}
} else if (pr->pr_ip6s > 0) {
/* Remove addresses that aren't in the parent. */
for (ij = 0; ij < ppr->pr_ip6s; ij++)
if (IN6_ARE_ADDR_EQUAL(&pr->pr_ip6[0],
&ppr->pr_ip6[ij]))
break;
if (ij < ppr->pr_ip6s)
ii = 1;
else {
bcopy(pr->pr_ip6 + 1, pr->pr_ip6,
--pr->pr_ip6s * sizeof(*pr->pr_ip6));
ii = 0;
}
for (ij = 1; ii < pr->pr_ip6s; ) {
if (IN6_ARE_ADDR_EQUAL(&pr->pr_ip6[ii],
&ppr->pr_ip6[0])) {
ii++;
continue;
}
switch (ij >= ppr->pr_ip6s ? -1 :
prison_qcmp_v6(&pr->pr_ip6[ii], &ppr->pr_ip6[ij])) {
case -1:
bcopy(pr->pr_ip6 + ii + 1, pr->pr_ip6 + ii,
(--pr->pr_ip6s - ii) * sizeof(*pr->pr_ip6));
break;
case 0:
ii++;
ij++;
break;
case 1:
ij++;
break;
}
}
if (pr->pr_ip6s == 0) {
free(pr->pr_ip6, M_PRISON);
pr->pr_ip6 = NULL;
}
}
return 0;
}
/*
* 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_ip6 == NULL) {
mtx_unlock(&pr->pr_mtx);
return (EAFNOSUPPORT);
}
bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
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_ip6 == 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 && pr->pr_ip6s == 1)
bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
mtx_unlock(&pr->pr_mtx);
return (0);
}
error = prison_check_ip6_locked(pr, ia6);
if (error == EADDRNOTAVAIL && IN6_IS_ADDR_LOOPBACK(ia6)) {
bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
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_ip6 == NULL) {
mtx_unlock(&pr->pr_mtx);
return (EAFNOSUPPORT);
}
if (IN6_IS_ADDR_LOOPBACK(ia6) &&
prison_check_ip6_locked(pr, ia6) == EADDRNOTAVAIL) {
bcopy(&pr->pr_ip6[0], ia6, sizeof(struct in6_addr));
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)
{
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 = prison_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(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_ip6 == NULL) {
mtx_unlock(&pr->pr_mtx);
return (EAFNOSUPPORT);
}
error = prison_check_ip6_locked(pr, ia6);
mtx_unlock(&pr->pr_mtx);
return (error);
}