2 * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
4 * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
5 * Miika Komu <miika@iki.fi>
6 * Herbert Xu <herbert@gondor.apana.org.au>
7 * Abhinav Pathak <abhinav.pathak@hiit.fi>
8 * Jeff Ahrenholz <ahrenholz@gmail.com>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/stringify.h>
16 #include <net/dsfield.h>
18 #include <net/inet_ecn.h>
22 /* Add encapsulation header.
24 * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
25 * The following fields in it shall be filled in by x->type->output:
28 * On exit, skb->h will be set to the start of the encapsulation header to be
29 * filled in by x->type->output and the mac header will be set to the
30 * nextheader field of the extension header directly preceding the
31 * encapsulation header, or in its absence, that of the top IP header.
32 * The value of skb->data and the network header will always point to the
35 static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
37 struct ipv6hdr *iph, *top_iph;
41 skb_push(skb, x->props.header_len);
44 hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
45 memmove(skb->data, iph, hdr_len);
47 skb_set_mac_header(skb, offsetof(struct ipv6hdr, nexthdr));
48 skb_reset_network_header(skb);
49 skb_set_transport_header(skb, sizeof(struct ipv6hdr));
50 top_iph = ipv6_hdr(skb);
52 ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
53 ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
58 static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
61 const unsigned char *old_mac;
62 int size = sizeof(struct ipv6hdr);
65 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
69 memmove(skb->data, skb_network_header(skb), size);
70 skb_reset_network_header(skb);
72 old_mac = skb_mac_header(skb);
73 skb_set_mac_header(skb, -skb->mac_len);
74 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
77 ip6h->payload_len = htons(skb->len - size);
78 ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
79 ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
85 static struct xfrm_mode xfrm6_beet_mode = {
86 .input = xfrm6_beet_input,
87 .output = xfrm6_beet_output,
89 .encap = XFRM_MODE_BEET,
92 static int __init xfrm6_beet_init(void)
94 return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
97 static void __exit xfrm6_beet_exit(void)
101 err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
105 module_init(xfrm6_beet_init);
106 module_exit(xfrm6_beet_exit);
107 MODULE_LICENSE("GPL");
108 MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);