blob: 0c742faaa30bb84cb309962208f9591b64fc5767 [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
8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/skbuff.h>
12#include <linux/stringify.h>
13#include <net/dsfield.h>
14#include <net/dst.h>
15#include <net/inet_ecn.h>
16#include <net/ipv6.h>
17#include <net/xfrm.h>
18
19static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
20{
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -070021 struct ipv6hdr *outer_iph = ipv6_hdr(skb);
Arnaldo Carvalho de Melo39b89162007-04-10 21:06:25 -070022 struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070023
24 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
25 IP6_ECN_set_ce(inner_iph);
26}
27
28/* Add encapsulation header.
29 *
Herbert Xuceb1eec82007-10-10 15:45:52 -070030 * The top IP header will be constructed per RFC 2401.
Herbert Xub59f45d2006-05-27 23:05:54 -070031 */
Herbert Xu195ad6a2007-12-20 13:53:40 -080032static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
Herbert Xub59f45d2006-05-27 23:05:54 -070033{
34 struct dst_entry *dst = skb->dst;
Herbert Xu36cf9ac2007-11-13 21:40:52 -080035 struct ipv6hdr *top_iph;
Herbert Xub59f45d2006-05-27 23:05:54 -070036 int dsfield;
37
Herbert Xu7b277b12007-10-10 15:44:06 -070038 skb_set_network_header(skb, -x->props.header_len);
Herbert Xu37fedd32007-10-10 15:44:44 -070039 skb->mac_header = skb->network_header +
40 offsetof(struct ipv6hdr, nexthdr);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080041 skb->transport_header = skb->network_header + sizeof(*top_iph);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -070042 top_iph = ipv6_hdr(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070043
44 top_iph->version = 6;
Herbert Xu36cf9ac2007-11-13 21:40:52 -080045
46 memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
47 sizeof(top_iph->flow_lbl));
48 top_iph->nexthdr = x->inner_mode->afinfo->proto;
49
50 dsfield = XFRM_MODE_SKB_CB(skb)->tos;
Herbert Xub59f45d2006-05-27 23:05:54 -070051 dsfield = INET_ECN_encapsulate(dsfield, dsfield);
52 if (x->props.flags & XFRM_STATE_NOECN)
53 dsfield &= ~INET_ECN_MASK;
54 ipv6_change_dsfield(top_iph, 0, dsfield);
Herbert Xub59f45d2006-05-27 23:05:54 -070055 top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
56 ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
57 ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
58 return 0;
59}
60
Herbert Xu195ad6a2007-12-20 13:53:40 -080061static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
Herbert Xub59f45d2006-05-27 23:05:54 -070062{
63 int err = -EINVAL;
Arnaldo Carvalho de Melo39f69c62007-03-10 12:40:27 -030064 const unsigned char *old_mac;
Herbert Xub59f45d2006-05-27 23:05:54 -070065
Herbert Xu227620e2007-11-13 21:41:28 -080066 if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
Herbert Xub59f45d2006-05-27 23:05:54 -070067 goto out;
68 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
69 goto out;
70
71 if (skb_cloned(skb) &&
72 (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
73 goto out;
74
Herbert Xu227620e2007-11-13 21:41:28 -080075 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
76 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
77 ipipv6_hdr(skb));
78 if (!(x->props.flags & XFRM_STATE_NOECN))
79 ipip6_ecn_decapsulate(skb);
80
Arnaldo Carvalho de Melo98e399f2007-03-19 15:33:04 -070081 old_mac = skb_mac_header(skb);
Arnaldo Carvalho de Melo39f69c62007-03-10 12:40:27 -030082 skb_set_mac_header(skb, -skb->mac_len);
Arnaldo Carvalho de Melo98e399f2007-03-19 15:33:04 -070083 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -070084 skb_reset_network_header(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070085 err = 0;
86
87out:
88 return err;
89}
90
91static struct xfrm_mode xfrm6_tunnel_mode = {
Herbert Xu195ad6a2007-12-20 13:53:40 -080092 .input2 = xfrm6_mode_tunnel_input,
Herbert Xu227620e2007-11-13 21:41:28 -080093 .input = xfrm_prepare_input,
Herbert Xu195ad6a2007-12-20 13:53:40 -080094 .output2 = xfrm6_mode_tunnel_output,
Herbert Xu36cf9ac2007-11-13 21:40:52 -080095 .output = xfrm6_prepare_output,
Herbert Xub59f45d2006-05-27 23:05:54 -070096 .owner = THIS_MODULE,
97 .encap = XFRM_MODE_TUNNEL,
Herbert Xu1bfcb102007-10-17 21:31:50 -070098 .flags = XFRM_MODE_FLAG_TUNNEL,
Herbert Xub59f45d2006-05-27 23:05:54 -070099};
100
Herbert Xu195ad6a2007-12-20 13:53:40 -0800101static int __init xfrm6_mode_tunnel_init(void)
Herbert Xub59f45d2006-05-27 23:05:54 -0700102{
103 return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
104}
105
Herbert Xu195ad6a2007-12-20 13:53:40 -0800106static void __exit xfrm6_mode_tunnel_exit(void)
Herbert Xub59f45d2006-05-27 23:05:54 -0700107{
108 int err;
109
110 err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
111 BUG_ON(err);
112}
113
Herbert Xu195ad6a2007-12-20 13:53:40 -0800114module_init(xfrm6_mode_tunnel_init);
115module_exit(xfrm6_mode_tunnel_exit);
Herbert Xub59f45d2006-05-27 23:05:54 -0700116MODULE_LICENSE("GPL");
117MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);