linux/net/ipv6/xfrm6_mode_beet.c
Joakim Koskela abf5cdb89d ipsec: Interfamily IPSec BEET, ipv4-inner ipv6-outer
Here's a revised version, based on Herbert's comments, of a fix for
the ipv4-inner, ipv6-outer interfamily ipsec beet mode. It fixes the
network header adjustment during interfamily, as well as makes sure
that we reserve enough room for the new ipv6 header if we might have
something else as the inner family. Also, the ipv4 pseudo header
construction was added.

Signed-off-by: Joakim Koskela <jookos@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-06 02:40:25 -07:00

138 lines
3.5 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>
static void xfrm6_beet_make_header(struct sk_buff *skb)
{
struct ipv6hdr *iph = ipv6_hdr(skb);
iph->version = 6;
memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
sizeof(iph->flow_lbl));
iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;
ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
}
/* Add encapsulation header.
*
* The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
*/
static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *top_iph;
struct ip_beet_phdr *ph;
struct iphdr *iphv4;
int optlen, hdr_len;
iphv4 = ip_hdr(skb);
hdr_len = 0;
optlen = XFRM_MODE_SKB_CB(skb)->optlen;
if (unlikely(optlen))
hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
skb_set_network_header(skb, -x->props.header_len - hdr_len);
if (x->sel.family != AF_INET6)
skb->network_header += IPV4_BEET_PHMAXLEN;
skb->mac_header = skb->network_header +
offsetof(struct ipv6hdr, nexthdr);
skb->transport_header = skb->network_header + sizeof(*top_iph);
ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len);
xfrm6_beet_make_header(skb);
top_iph = ipv6_hdr(skb);
if (unlikely(optlen)) {
BUG_ON(optlen < 0);
ph->padlen = 4 - (optlen & 4);
ph->hdrlen = optlen / 8;
ph->nexthdr = top_iph->nexthdr;
if (ph->padlen)
memset(ph + 1, IPOPT_NOP, ph->padlen);
top_iph->nexthdr = IPPROTO_BEETPH;
}
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;
err = skb_cow_head(skb, size + skb->mac_len);
if (err)
goto out;
__skb_push(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);
xfrm6_beet_make_header(skb);
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 = {
.input2 = xfrm6_beet_input,
.input = xfrm_prepare_input,
.output2 = xfrm6_beet_output,
.output = xfrm6_prepare_output,
.owner = THIS_MODULE,
.encap = XFRM_MODE_BEET,
.flags = XFRM_MODE_FLAG_TUNNEL,
};
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);