2006-01-07 07:06:48 +00:00
|
|
|
/* 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;
|
|
|
|
}
|
|
|
|
|
2006-01-17 10:26:34 +00:00
|
|
|
static int checkentry(const char *tablename, const void *ip_void,
|
2006-01-07 07:06:48 +00:00
|
|
|
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);
|