blob: 261e6e6f487e818eba1e670bace7f031efd60631 [file] [log] [blame]
Herbert Xub59f45d2006-05-27 23:05:54 -07001/*
2 * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
3 *
4 * Copyright (C) 2002 USAGI/WIDE Project
5 * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09008#include <linux/gfp.h>
Herbert Xub59f45d2006-05-27 23:05:54 -07009#include <linux/init.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/skbuff.h>
13#include <linux/stringify.h>
14#include <net/dsfield.h>
15#include <net/dst.h>
16#include <net/inet_ecn.h>
David S. Millerabbf46a2010-12-12 21:14:46 -080017#include <net/ip6_route.h>
Herbert Xub59f45d2006-05-27 23:05:54 -070018#include <net/ipv6.h>
19#include <net/xfrm.h>
20
21static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
22{
Eric Dumazetb71d1d42011-04-22 04:53:02 +000023 const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
Arnaldo Carvalho de Melo39b89162007-04-10 21:06:25 -070024 struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070025
26 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
27 IP6_ECN_set_ce(inner_iph);
28}
29
30/* Add encapsulation header.
31 *
Herbert Xuceb1eec2007-10-10 15:45:52 -070032 * The top IP header will be constructed per RFC 2401.
Herbert Xub59f45d2006-05-27 23:05:54 -070033 */
Herbert Xu195ad6a2007-12-20 13:53:40 -080034static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
Herbert Xub59f45d2006-05-27 23:05:54 -070035{
Eric Dumazetadf30902009-06-02 05:19:30 +000036 struct dst_entry *dst = skb_dst(skb);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080037 struct ipv6hdr *top_iph;
Herbert Xub59f45d2006-05-27 23:05:54 -070038 int dsfield;
39
Herbert Xu7b277b12007-10-10 15:44:06 -070040 skb_set_network_header(skb, -x->props.header_len);
Herbert Xu37fedd32007-10-10 15:44:44 -070041 skb->mac_header = skb->network_header +
42 offsetof(struct ipv6hdr, nexthdr);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080043 skb->transport_header = skb->network_header + sizeof(*top_iph);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -070044 top_iph = ipv6_hdr(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070045
46 top_iph->version = 6;
Herbert Xu36cf9ac2007-11-13 21:40:52 -080047
48 memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
49 sizeof(top_iph->flow_lbl));
Eric Dumazetadf30902009-06-02 05:19:30 +000050 top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080051
52 dsfield = XFRM_MODE_SKB_CB(skb)->tos;
Herbert Xub59f45d2006-05-27 23:05:54 -070053 dsfield = INET_ECN_encapsulate(dsfield, dsfield);
54 if (x->props.flags & XFRM_STATE_NOECN)
55 dsfield &= ~INET_ECN_MASK;
56 ipv6_change_dsfield(top_iph, 0, dsfield);
David S. Millerabbf46a2010-12-12 21:14:46 -080057 top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +000058 top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
59 top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
Herbert Xub59f45d2006-05-27 23:05:54 -070060 return 0;
61}
62
Herbert Xu195ad6a2007-12-20 13:53:40 -080063static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
Herbert Xub59f45d2006-05-27 23:05:54 -070064{
65 int err = -EINVAL;
Arnaldo Carvalho de Melo39f69c62007-03-10 12:40:27 -030066 const unsigned char *old_mac;
Herbert Xub59f45d2006-05-27 23:05:54 -070067
Herbert Xu227620e2007-11-13 21:41:28 -080068 if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
Herbert Xub59f45d2006-05-27 23:05:54 -070069 goto out;
70 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
71 goto out;
72
73 if (skb_cloned(skb) &&
74 (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
75 goto out;
76
Herbert Xu227620e2007-11-13 21:41:28 -080077 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
78 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
79 ipipv6_hdr(skb));
80 if (!(x->props.flags & XFRM_STATE_NOECN))
81 ipip6_ecn_decapsulate(skb);
82
Arnaldo Carvalho de Melo98e399f2007-03-19 15:33:04 -070083 old_mac = skb_mac_header(skb);
Arnaldo Carvalho de Melo39f69c62007-03-10 12:40:27 -030084 skb_set_mac_header(skb, -skb->mac_len);
Arnaldo Carvalho de Melo98e399f2007-03-19 15:33:04 -070085 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -070086 skb_reset_network_header(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070087 err = 0;
88
89out:
90 return err;
91}
92
93static struct xfrm_mode xfrm6_tunnel_mode = {
Herbert Xu195ad6a2007-12-20 13:53:40 -080094 .input2 = xfrm6_mode_tunnel_input,
Herbert Xu227620e2007-11-13 21:41:28 -080095 .input = xfrm_prepare_input,
Herbert Xu195ad6a2007-12-20 13:53:40 -080096 .output2 = xfrm6_mode_tunnel_output,
Herbert Xu36cf9ac2007-11-13 21:40:52 -080097 .output = xfrm6_prepare_output,
Herbert Xub59f45d2006-05-27 23:05:54 -070098 .owner = THIS_MODULE,
99 .encap = XFRM_MODE_TUNNEL,
Herbert Xu1bfcb102007-10-17 21:31:50 -0700100 .flags = XFRM_MODE_FLAG_TUNNEL,
Herbert Xub59f45d2006-05-27 23:05:54 -0700101};
102
Herbert Xu195ad6a2007-12-20 13:53:40 -0800103static int __init xfrm6_mode_tunnel_init(void)
Herbert Xub59f45d2006-05-27 23:05:54 -0700104{
105 return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
106}
107
Herbert Xu195ad6a2007-12-20 13:53:40 -0800108static void __exit xfrm6_mode_tunnel_exit(void)
Herbert Xub59f45d2006-05-27 23:05:54 -0700109{
110 int err;
111
112 err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
113 BUG_ON(err);
114}
115
Herbert Xu195ad6a2007-12-20 13:53:40 -0800116module_init(xfrm6_mode_tunnel_init);
117module_exit(xfrm6_mode_tunnel_exit);
Herbert Xub59f45d2006-05-27 23:05:54 -0700118MODULE_LICENSE("GPL");
119MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);