Commit e16a8f0b authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

[NETFILTER]: Add ipt_policy/ip6t_policy matches


Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent eb9c7ebe
#ifndef _IPT_POLICY_H
#define _IPT_POLICY_H
#define IPT_POLICY_MAX_ELEM 4
enum ipt_policy_flags
{
IPT_POLICY_MATCH_IN = 0x1,
IPT_POLICY_MATCH_OUT = 0x2,
IPT_POLICY_MATCH_NONE = 0x4,
IPT_POLICY_MATCH_STRICT = 0x8,
};
enum ipt_policy_modes
{
IPT_POLICY_MODE_TRANSPORT,
IPT_POLICY_MODE_TUNNEL
};
struct ipt_policy_spec
{
u_int8_t saddr:1,
daddr:1,
proto:1,
mode:1,
spi:1,
reqid:1;
};
struct ipt_policy_elem
{
u_int32_t saddr;
u_int32_t smask;
u_int32_t daddr;
u_int32_t dmask;
u_int32_t spi;
u_int32_t reqid;
u_int8_t proto;
u_int8_t mode;
struct ipt_policy_spec match;
struct ipt_policy_spec invert;
};
struct ipt_policy_info
{
struct ipt_policy_elem pol[IPT_POLICY_MAX_ELEM];
u_int16_t flags;
u_int16_t len;
};
#endif /* _IPT_POLICY_H */
#ifndef _IP6T_POLICY_H
#define _IP6T_POLICY_H
#define IP6T_POLICY_MAX_ELEM 4
enum ip6t_policy_flags
{
IP6T_POLICY_MATCH_IN = 0x1,
IP6T_POLICY_MATCH_OUT = 0x2,
IP6T_POLICY_MATCH_NONE = 0x4,
IP6T_POLICY_MATCH_STRICT = 0x8,
};
enum ip6t_policy_modes
{
IP6T_POLICY_MODE_TRANSPORT,
IP6T_POLICY_MODE_TUNNEL
};
struct ip6t_policy_spec
{
u_int8_t saddr:1,
daddr:1,
proto:1,
mode:1,
spi:1,
reqid:1;
};
struct ip6t_policy_elem
{
struct in6_addr saddr;
struct in6_addr smask;
struct in6_addr daddr;
struct in6_addr dmask;
u_int32_t spi;
u_int32_t reqid;
u_int8_t proto;
u_int8_t mode;
struct ip6t_policy_spec match;
struct ip6t_policy_spec invert;
};
struct ip6t_policy_info
{
struct ip6t_policy_elem pol[IP6T_POLICY_MAX_ELEM];
u_int16_t flags;
u_int16_t len;
};
#endif /* _IP6T_POLICY_H */
......@@ -487,6 +487,16 @@ config IP_NF_MATCH_STRING
To compile it as a module, choose M here. If unsure, say N.
config IP_NF_MATCH_POLICY
tristate "IPsec policy match support"
depends on IP_NF_IPTABLES && XFRM
help
Policy matching allows you to match packets based on the
IPsec policy that was used during decapsulation/will
be used during encapsulation.
To compile it as a module, choose M here. If unsure, say N.
# `filter', generic and specific targets
config IP_NF_FILTER
tristate "Packet filtering"
......
......@@ -72,6 +72,7 @@ obj-$(CONFIG_IP_NF_MATCH_TCPMSS) += ipt_tcpmss.o
obj-$(CONFIG_IP_NF_MATCH_REALM) += ipt_realm.o
obj-$(CONFIG_IP_NF_MATCH_ADDRTYPE) += ipt_addrtype.o
obj-$(CONFIG_IP_NF_MATCH_PHYSDEV) += ipt_physdev.o
obj-$(CONFIG_IP_NF_MATCH_POLICY) += ipt_policy.o
obj-$(CONFIG_IP_NF_MATCH_COMMENT) += ipt_comment.o
obj-$(CONFIG_IP_NF_MATCH_STRING) += ipt_string.o
......
/* IP tables module for matching IPsec policy
*
* Copyright (c) 2004,2005 Patrick McHardy, <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <net/xfrm.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_policy.h>
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("IPtables IPsec policy matching module");
MODULE_LICENSE("GPL");
static inline int
match_xfrm_state(struct xfrm_state *x, const struct ipt_policy_elem *e)
{
#define MATCH(x,y) (!e->match.x || ((e->x == (y)) ^ e->invert.x))
return MATCH(saddr, x->props.saddr.a4 & e->smask) &&
MATCH(daddr, x->id.daddr.a4 & e->dmask) &&
MATCH(proto, x->id.proto) &&
MATCH(mode, x->props.mode) &&
MATCH(spi, x->id.spi) &&
MATCH(reqid, x->props.reqid);
}
static int
match_policy_in(const struct sk_buff *skb, const struct ipt_policy_info *info)
{
const struct ipt_policy_elem *e;
struct sec_path *sp = skb->sp;
int strict = info->flags & IPT_POLICY_MATCH_STRICT;
int i, pos;
if (sp == NULL)
return -1;
if (strict && info->len != sp->len)
return 0;
for (i = sp->len - 1; i >= 0; i--) {
pos = strict ? i - sp->len + 1 : 0;
if (pos >= info->len)
return 0;
e = &info->pol[pos];
if (match_xfrm_state(sp->x[i].xvec, e)) {
if (!strict)
return 1;
} else if (strict)
return 0;
}
return strict ? 1 : 0;
}
static int
match_policy_out(const struct sk_buff *skb, const struct ipt_policy_info *info)
{
const struct ipt_policy_elem *e;
struct dst_entry *dst = skb->dst;
int strict = info->flags & IPT_POLICY_MATCH_STRICT;
int i, pos;
if (dst->xfrm == NULL)
return -1;
for (i = 0; dst && dst->xfrm; dst = dst->child, i++) {
pos = strict ? i : 0;
if (pos >= info->len)
return 0;
e = &info->pol[pos];
if (match_xfrm_state(dst->xfrm, e)) {
if (!strict)
return 1;
} else if (strict)
return 0;
}
return strict ? 1 : 0;
}
static int match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo, int offset, int *hotdrop)
{
const struct ipt_policy_info *info = matchinfo;
int ret;
if (info->flags & IPT_POLICY_MATCH_IN)
ret = match_policy_in(skb, info);
else
ret = match_policy_out(skb, info);
if (ret < 0)
ret = info->flags & IPT_POLICY_MATCH_NONE ? 1 : 0;
else if (info->flags & IPT_POLICY_MATCH_NONE)
ret = 0;
return ret;
}
static int checkentry(const char *tablename, const struct ipt_ip *ip,
void *matchinfo, unsigned int matchsize,
unsigned int hook_mask)
{
struct ipt_policy_info *info = matchinfo;
if (matchsize != IPT_ALIGN(sizeof(*info))) {
printk(KERN_ERR "ipt_policy: matchsize %u != %zu\n",
matchsize, IPT_ALIGN(sizeof(*info)));
return 0;
}
if (!(info->flags & (IPT_POLICY_MATCH_IN|IPT_POLICY_MATCH_OUT))) {
printk(KERN_ERR "ipt_policy: neither incoming nor "
"outgoing policy selected\n");
return 0;
}
if (hook_mask & (1 << NF_IP_PRE_ROUTING | 1 << NF_IP_LOCAL_IN)
&& info->flags & IPT_POLICY_MATCH_OUT) {
printk(KERN_ERR "ipt_policy: output policy not valid in "
"PRE_ROUTING and INPUT\n");
return 0;
}
if (hook_mask & (1 << NF_IP_POST_ROUTING | 1 << NF_IP_LOCAL_OUT)
&& info->flags & IPT_POLICY_MATCH_IN) {
printk(KERN_ERR "ipt_policy: input policy not valid in "
"POST_ROUTING and OUTPUT\n");
return 0;
}
if (info->len > IPT_POLICY_MAX_ELEM) {
printk(KERN_ERR "ipt_policy: too many policy elements\n");
return 0;
}
return 1;
}
static struct ipt_match policy_match = {
.name = "policy",
.match = match,
.checkentry = checkentry,
.me = THIS_MODULE,
};
static int __init init(void)
{
return ipt_register_match(&policy_match);
}
static void __exit fini(void)
{
ipt_unregister_match(&policy_match);
}
module_init(init);
module_exit(fini);
......@@ -179,6 +179,16 @@ config IP6_NF_MATCH_PHYSDEV
To compile it as a module, choose M here. If unsure, say N.
config IP6_NF_MATCH_POLICY
tristate "IPsec policy match support"
depends on IP6_NF_IPTABLES && XFRM
help
Policy matching allows you to match packets based on the
IPsec policy that was used during decapsulation/will
be used during encapsulation.
To compile it as a module, choose M here. If unsure, say N.
# The targets
config IP6_NF_FILTER
tristate "Packet filtering"
......
......@@ -13,6 +13,7 @@ obj-$(CONFIG_IP6_NF_MATCH_OPTS) += ip6t_hbh.o ip6t_dst.o
obj-$(CONFIG_IP6_NF_MATCH_IPV6HEADER) += ip6t_ipv6header.o
obj-$(CONFIG_IP6_NF_MATCH_FRAG) += ip6t_frag.o
obj-$(CONFIG_IP6_NF_MATCH_AHESP) += ip6t_esp.o ip6t_ah.o
obj-$(CONFIG_IP6_NF_MATCH_POLICY) += ip6t_policy.o
obj-$(CONFIG_IP6_NF_MATCH_EUI64) += ip6t_eui64.o
obj-$(CONFIG_IP6_NF_MATCH_MULTIPORT) += ip6t_multiport.o
obj-$(CONFIG_IP6_NF_MATCH_OWNER) += ip6t_owner.o
......
/* IP tables module for matching IPsec policy
*
* Copyright (c) 2004,2005 Patrick McHardy, <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <net/xfrm.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter_ipv6/ip6t_policy.h>
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("IPtables IPsec policy matching module");
MODULE_LICENSE("GPL");
static inline int
match_xfrm_state(struct xfrm_state *x, const struct ip6t_policy_elem *e)
{
#define MATCH_ADDR(x,y,z) (!e->match.x || \
((ip6_masked_addrcmp((z), &e->x, &e->y)) == 0) ^ e->invert.x)
#define MATCH(x,y) (!e->match.x || ((e->x == (y)) ^ e->invert.x))
return MATCH_ADDR(saddr, smask, (struct in6_addr *)&x->props.saddr.a6) &&
MATCH_ADDR(daddr, dmask, (struct in6_addr *)&x->id.daddr.a6) &&
MATCH(proto, x->id.proto) &&
MATCH(mode, x->props.mode) &&
MATCH(spi, x->id.spi) &&
MATCH(reqid, x->props.reqid);
}
static int
match_policy_in(const struct sk_buff *skb, const struct ip6t_policy_info *info)
{
const struct ip6t_policy_elem *e;
struct sec_path *sp = skb->sp;
int strict = info->flags & IP6T_POLICY_MATCH_STRICT;
int i, pos;
if (sp == NULL)
return -1;
if (strict && info->len != sp->len)
return 0;
for (i = sp->len - 1; i >= 0; i--) {
pos = strict ? i - sp->len + 1 : 0;
if (pos >= info->len)
return 0;
e = &info->pol[pos];
if (match_xfrm_state(sp->x[i].xvec, e)) {
if (!strict)
return 1;
} else if (strict)
return 0;
}
return strict ? 1 : 0;
}
static int
match_policy_out(const struct sk_buff *skb, const struct ip6t_policy_info *info)
{
const struct ip6t_policy_elem *e;
struct dst_entry *dst = skb->dst;
int strict = info->flags & IP6T_POLICY_MATCH_STRICT;
int i, pos;
if (dst->xfrm == NULL)
return -1;
for (i = 0; dst && dst->xfrm; dst = dst->child, i++) {
pos = strict ? i : 0;
if (pos >= info->len)
return 0;
e = &info->pol[pos];
if (match_xfrm_state(dst->xfrm, e)) {
if (!strict)
return 1;
} else if (strict)
return 0;
}
return strict ? 1 : 0;
}
static int match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
const struct ip6t_policy_info *info = matchinfo;
int ret;
if (info->flags & IP6T_POLICY_MATCH_IN)
ret = match_policy_in(skb, info);
else
ret = match_policy_out(skb, info);
if (ret < 0)
ret = info->flags & IP6T_POLICY_MATCH_NONE ? 1 : 0;
else if (info->flags & IP6T_POLICY_MATCH_NONE)
ret = 0;
return ret;
}
static int checkentry(const char *tablename, const struct ip6t_ip6 *ip,
void *matchinfo, unsigned int matchsize,
unsigned int hook_mask)
{
struct ip6t_policy_info *info = matchinfo;
if (matchsize != IP6T_ALIGN(sizeof(*info))) {
printk(KERN_ERR "ip6t_policy: matchsize %u != %zu\n",
matchsize, IP6T_ALIGN(sizeof(*info)));
return 0;
}
if (!(info->flags & (IP6T_POLICY_MATCH_IN|IP6T_POLICY_MATCH_OUT))) {
printk(KERN_ERR "ip6t_policy: neither incoming nor "
"outgoing policy selected\n");
return 0;
}
if (hook_mask & (1 << NF_IP6_PRE_ROUTING | 1 << NF_IP6_LOCAL_IN)
&& info->flags & IP6T_POLICY_MATCH_OUT) {
printk(KERN_ERR "ip6t_policy: output policy not valid in "
"PRE_ROUTING and INPUT\n");
return 0;
}
if (hook_mask & (1 << NF_IP6_POST_ROUTING | 1 << NF_IP6_LOCAL_OUT)
&& info->flags & IP6T_POLICY_MATCH_IN) {
printk(KERN_ERR "ip6t_policy: input policy not valid in "
"POST_ROUTING and OUTPUT\n");
return 0;
}
if (info->len > IP6T_POLICY_MAX_ELEM) {
printk(KERN_ERR "ip6t_policy: too many policy elements\n");
return 0;
}
return 1;
}
static struct ip6t_match policy_match = {
.name = "policy",
.match = match,
.checkentry = checkentry,
.me = THIS_MODULE,
};
static int __init init(void)
{
return ip6t_register_match(&policy_match);
}
static void __exit fini(void)
{
ip6t_unregister_match(&policy_match);
}
module_init(init);
module_exit(fini);
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