blob: 2e61d6ddece303665ce8209f845c9f25195ce322 [file] [log] [blame]
* xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
* Copyright (c) 2006 Diego Beltrami <>
* Miika Komu <>
* Herbert Xu <>
* Abhinav Pathak <>
* Jeff Ahrenholz <>
#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 skb->nh 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 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);
(prevhdr - x->props.header_len) - skb->data);
skb_set_transport_header(skb, hdr_len);
memmove(skb->data, iph, hdr_len);
top_iph = ipv6_hdr(skb);
skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
skb->network_header += offsetof(struct ipv6hdr, nexthdr);
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);
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;
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);