blob: edcfffa9e87b1395723cbf5e07df05ed3bca43ee [file] [log] [blame]
Diego Beltrami0a694522006-10-03 23:47:05 -07001/*
2 * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6.
3 *
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>
9 */
10
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>
17#include <net/dst.h>
18#include <net/inet_ecn.h>
19#include <net/ipv6.h>
20#include <net/xfrm.h>
21
22/* Add encapsulation header.
23 *
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:
26 * payload_len
27 *
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 skb->nh will be set to the nextheader field
30 * of the extension header directly preceding the encapsulation header, or in
31 * its absence, that of the top IP header. The value of skb->data will always
32 * point to the top IP header.
33 */
34static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
35{
36 struct ipv6hdr *iph, *top_iph;
37 u8 *prevhdr;
38 int hdr_len;
39
40 skb_push(skb, x->props.header_len);
41 iph = skb->nh.ipv6h;
42
43 hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
44 skb->nh.raw = prevhdr - x->props.header_len;
45 skb->h.raw = skb->data + hdr_len;
46 memmove(skb->data, iph, hdr_len);
47
48 skb->nh.raw = skb->data;
49 top_iph = skb->nh.ipv6h;
50 skb->nh.raw = &top_iph->nexthdr;
51 skb->h.ipv6h = top_iph + 1;
52
53 ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
54 ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
55
56 return 0;
57}
58
59static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
60{
61 struct ipv6hdr *ip6h;
62 int size = sizeof(struct ipv6hdr);
63 int err = -EINVAL;
64
65 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
66 goto out;
67
68 skb_push(skb, size);
69 memmove(skb->data, skb->nh.raw, size);
70 skb->nh.raw = skb->data;
71
72 skb->mac.raw = memmove(skb->data - skb->mac_len,
73 skb->mac.raw, skb->mac_len);
74
75 ip6h = skb->nh.ipv6h;
76 ip6h->payload_len = htons(skb->len - size);
77 ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
78 ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
79 err = 0;
80out:
81 return err;
82}
83
84static struct xfrm_mode xfrm6_beet_mode = {
85 .input = xfrm6_beet_input,
86 .output = xfrm6_beet_output,
87 .owner = THIS_MODULE,
88 .encap = XFRM_MODE_BEET,
89};
90
91static int __init xfrm6_beet_init(void)
92{
93 return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
94}
95
96static void __exit xfrm6_beet_exit(void)
97{
98 int err;
99
100 err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
101 BUG_ON(err);
102}
103
104module_init(xfrm6_beet_init);
105module_exit(xfrm6_beet_exit);
106MODULE_LICENSE("GPL");
107MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);