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.
26 static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
28 struct ipv6hdr *top_iph;
30 skb_set_network_header(skb, -x->props.header_len);
31 skb->mac_header = skb->network_header +
32 offsetof(struct ipv6hdr, nexthdr);
33 skb->transport_header = skb->network_header + sizeof(*top_iph);
34 top_iph = ipv6_hdr(skb);
38 memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
39 sizeof(top_iph->flow_lbl));
40 top_iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;
42 ipv6_change_dsfield(top_iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
43 top_iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
44 ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
45 ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
49 static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
52 const unsigned char *old_mac;
53 int size = sizeof(struct ipv6hdr);
56 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
60 memmove(skb->data, skb_network_header(skb), size);
61 skb_reset_network_header(skb);
63 old_mac = skb_mac_header(skb);
64 skb_set_mac_header(skb, -skb->mac_len);
65 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
68 ip6h->payload_len = htons(skb->len - size);
69 ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
70 ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
76 static struct xfrm_mode xfrm6_beet_mode = {
77 .input = xfrm6_beet_input,
78 .output2 = xfrm6_beet_output,
79 .output = xfrm6_prepare_output,
81 .encap = XFRM_MODE_BEET,
82 .flags = XFRM_MODE_FLAG_TUNNEL,
85 static int __init xfrm6_beet_init(void)
87 return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
90 static void __exit xfrm6_beet_exit(void)
94 err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
98 module_init(xfrm6_beet_init);
99 module_exit(xfrm6_beet_exit);
100 MODULE_LICENSE("GPL");
101 MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);