blob: b809812c8d30a85b13732fd2071d524da6a81807 [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>
17#include <net/ipv6.h>
18#include <net/xfrm.h>
19
20static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
21{
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -070022 struct ipv6hdr *outer_iph = ipv6_hdr(skb);
Arnaldo Carvalho de Melo39b89162007-04-10 21:06:25 -070023 struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070024
25 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
26 IP6_ECN_set_ce(inner_iph);
27}
28
29/* Add encapsulation header.
30 *
Herbert Xuceb1eec82007-10-10 15:45:52 -070031 * The top IP header will be constructed per RFC 2401.
Herbert Xub59f45d2006-05-27 23:05:54 -070032 */
Herbert Xu195ad6a2007-12-20 13:53:40 -080033static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
Herbert Xub59f45d2006-05-27 23:05:54 -070034{
Eric Dumazetadf30902009-06-02 05:19:30 +000035 struct dst_entry *dst = skb_dst(skb);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080036 struct ipv6hdr *top_iph;
Herbert Xub59f45d2006-05-27 23:05:54 -070037 int dsfield;
38
Herbert Xu7b277b12007-10-10 15:44:06 -070039 skb_set_network_header(skb, -x->props.header_len);
Herbert Xu37fedd32007-10-10 15:44:44 -070040 skb->mac_header = skb->network_header +
41 offsetof(struct ipv6hdr, nexthdr);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080042 skb->transport_header = skb->network_header + sizeof(*top_iph);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -070043 top_iph = ipv6_hdr(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070044
45 top_iph->version = 6;
Herbert Xu36cf9ac2007-11-13 21:40:52 -080046
47 memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
48 sizeof(top_iph->flow_lbl));
Eric Dumazetadf30902009-06-02 05:19:30 +000049 top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080050
51 dsfield = XFRM_MODE_SKB_CB(skb)->tos;
Herbert Xub59f45d2006-05-27 23:05:54 -070052 dsfield = INET_ECN_encapsulate(dsfield, dsfield);
53 if (x->props.flags & XFRM_STATE_NOECN)
54 dsfield &= ~INET_ECN_MASK;
55 ipv6_change_dsfield(top_iph, 0, dsfield);
Herbert Xub59f45d2006-05-27 23:05:54 -070056 top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
57 ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
58 ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
59 return 0;
60}
61
Herbert Xu195ad6a2007-12-20 13:53:40 -080062static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
Herbert Xub59f45d2006-05-27 23:05:54 -070063{
64 int err = -EINVAL;
Arnaldo Carvalho de Melo39f69c62007-03-10 12:40:27 -030065 const unsigned char *old_mac;
Herbert Xub59f45d2006-05-27 23:05:54 -070066
Herbert Xu227620e2007-11-13 21:41:28 -080067 if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
Herbert Xub59f45d2006-05-27 23:05:54 -070068 goto out;
69 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
70 goto out;
71
72 if (skb_cloned(skb) &&
73 (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
74 goto out;
75
Herbert Xu227620e2007-11-13 21:41:28 -080076 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
77 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
78 ipipv6_hdr(skb));
79 if (!(x->props.flags & XFRM_STATE_NOECN))
80 ipip6_ecn_decapsulate(skb);
81
Arnaldo Carvalho de Melo98e399f2007-03-19 15:33:04 -070082 old_mac = skb_mac_header(skb);
Arnaldo Carvalho de Melo39f69c62007-03-10 12:40:27 -030083 skb_set_mac_header(skb, -skb->mac_len);
Arnaldo Carvalho de Melo98e399f2007-03-19 15:33:04 -070084 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -070085 skb_reset_network_header(skb);
Herbert Xub59f45d2006-05-27 23:05:54 -070086 err = 0;
87
88out:
89 return err;
90}
91
92static struct xfrm_mode xfrm6_tunnel_mode = {
Herbert Xu195ad6a2007-12-20 13:53:40 -080093 .input2 = xfrm6_mode_tunnel_input,
Herbert Xu227620e2007-11-13 21:41:28 -080094 .input = xfrm_prepare_input,
Herbert Xu195ad6a2007-12-20 13:53:40 -080095 .output2 = xfrm6_mode_tunnel_output,
Herbert Xu36cf9ac2007-11-13 21:40:52 -080096 .output = xfrm6_prepare_output,
Herbert Xub59f45d2006-05-27 23:05:54 -070097 .owner = THIS_MODULE,
98 .encap = XFRM_MODE_TUNNEL,
Herbert Xu1bfcb102007-10-17 21:31:50 -070099 .flags = XFRM_MODE_FLAG_TUNNEL,
Herbert Xub59f45d2006-05-27 23:05:54 -0700100};
101
Herbert Xu195ad6a2007-12-20 13:53:40 -0800102static int __init xfrm6_mode_tunnel_init(void)
Herbert Xub59f45d2006-05-27 23:05:54 -0700103{
104 return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
105}
106
Herbert Xu195ad6a2007-12-20 13:53:40 -0800107static void __exit xfrm6_mode_tunnel_exit(void)
Herbert Xub59f45d2006-05-27 23:05:54 -0700108{
109 int err;
110
111 err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
112 BUG_ON(err);
113}
114
Herbert Xu195ad6a2007-12-20 13:53:40 -0800115module_init(xfrm6_mode_tunnel_init);
116module_exit(xfrm6_mode_tunnel_exit);
Herbert Xub59f45d2006-05-27 23:05:54 -0700117MODULE_LICENSE("GPL");
118MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);