linux/net/ipv6/xfrm6_mode_beet.c
Herbert Xu bee0b40c06 [IPSEC] beet: Fix extension header support on output
The beet output function completely kills any extension headers by replacing
them with the IPv6 header.  This is because it essentially ignores the
result of ip6_find_1stfragopt by simply acting as if there aren't any
extension headers.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:55:53 -07:00

108 lines
3 KiB
C

/*
* xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
*
* Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
* Miika Komu <miika@iki.fi>
* Herbert Xu <herbert@gondor.apana.org.au>
* Abhinav Pathak <abhinav.pathak@hiit.fi>
* Jeff Ahrenholz <ahrenholz@gmail.com>
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/stringify.h>
#include <net/dsfield.h>
#include <net/dst.h>
#include <net/inet_ecn.h>
#include <net/ipv6.h>
#include <net/xfrm.h>
/* Add encapsulation header.
*
* The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
* The following fields in it shall be filled in by x->type->output:
* payload_len
*
* On exit, skb->h will be set to the start of the encapsulation header to be
* filled in by x->type->output and the mac header will be set to the
* nextheader field of the extension header directly preceding the
* encapsulation header, or in its absence, that of the top IP header.
* The value of skb->data and the network header will always point to the
* top IP header.
*/
static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *iph, *top_iph;
u8 *prevhdr;
int hdr_len;
skb_push(skb, x->props.header_len);
iph = ipv6_hdr(skb);
hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
memmove(skb->data, iph, hdr_len);
skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
skb_reset_network_header(skb);
skb_set_transport_header(skb, hdr_len);
top_iph = ipv6_hdr(skb);
ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
return 0;
}
static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *ip6h;
const unsigned char *old_mac;
int size = sizeof(struct ipv6hdr);
int err = -EINVAL;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto out;
skb_push(skb, size);
memmove(skb->data, skb_network_header(skb), size);
skb_reset_network_header(skb);
old_mac = skb_mac_header(skb);
skb_set_mac_header(skb, -skb->mac_len);
memmove(skb_mac_header(skb), old_mac, skb->mac_len);
ip6h = ipv6_hdr(skb);
ip6h->payload_len = htons(skb->len - size);
ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
err = 0;
out:
return err;
}
static struct xfrm_mode xfrm6_beet_mode = {
.input = xfrm6_beet_input,
.output = xfrm6_beet_output,
.owner = THIS_MODULE,
.encap = XFRM_MODE_BEET,
};
static int __init xfrm6_beet_init(void)
{
return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
}
static void __exit xfrm6_beet_exit(void)
{
int err;
err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
BUG_ON(err);
}
module_init(xfrm6_beet_init);
module_exit(xfrm6_beet_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);