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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
3 * Copyright (C) 2002 USAGI/WIDE Project
4 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09005 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
Herbert Xu406ef772007-10-08 17:16:30 -070012#include <linux/if_ether.h>
Herbert Xu36cf9ac2007-11-13 21:40:52 -080013#include <linux/kernel.h>
14#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/skbuff.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/icmpv6.h>
Patrick McHardy16a66772006-01-06 23:01:48 -080017#include <linux/netfilter_ipv6.h>
Herbert Xu36cf9ac2007-11-13 21:40:52 -080018#include <net/dst.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <net/ipv6.h>
20#include <net/xfrm.h>
21
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -070022int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
23 u8 **prevhdr)
24{
25 return ip6_find_1stfragopt(skb, prevhdr);
26}
27
YOSHIFUJI Hideaki71590392007-02-22 22:05:40 +090028EXPORT_SYMBOL(xfrm6_find_1stfragopt);
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030static int xfrm6_tunnel_check_size(struct sk_buff *skb)
31{
32 int mtu, ret = 0;
Eric Dumazetadf30902009-06-02 05:19:30 +000033 struct dst_entry *dst = skb_dst(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35 mtu = dst_mtu(dst);
36 if (mtu < IPV6_MIN_MTU)
37 mtu = IPV6_MIN_MTU;
38
Herbert Xu28a89452008-02-12 18:07:27 -080039 if (!skb->local_df && skb->len > mtu) {
Herbert Xu180e4252005-05-23 13:11:07 -070040 skb->dev = dst->dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
42 ret = -EMSGSIZE;
43 }
44
45 return ret;
46}
47
Herbert Xu36cf9ac2007-11-13 21:40:52 -080048int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049{
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 int err;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090051
Herbert Xu36cf9ac2007-11-13 21:40:52 -080052 err = xfrm6_tunnel_check_size(skb);
53 if (err)
54 return err;
55
Herbert Xu60d5fcf2007-11-19 18:47:58 -080056 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
57
Herbert Xu36cf9ac2007-11-13 21:40:52 -080058 return xfrm6_extract_header(skb);
59}
60
61int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
62{
63 int err;
64
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -070065 err = xfrm_inner_extract_output(x, skb);
Herbert Xu36cf9ac2007-11-13 21:40:52 -080066 if (err)
67 return err;
68
69 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
Herbert Xu862b82c2007-11-13 21:43:11 -080070#ifdef CONFIG_NETFILTER
71 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
72#endif
Herbert Xu36cf9ac2007-11-13 21:40:52 -080073
74 skb->protocol = htons(ETH_P_IPV6);
Steffen Klassertd1d88e5d2009-04-06 03:58:50 +000075 skb->local_df = 1;
Herbert Xu36cf9ac2007-11-13 21:40:52 -080076
77 return x->outer_mode->output2(x, skb);
78}
79EXPORT_SYMBOL(xfrm6_prepare_output);
80
Herbert Xu09b8f7a2006-06-22 03:08:03 -070081static int xfrm6_output_finish(struct sk_buff *skb)
82{
Herbert Xu862b82c2007-11-13 21:43:11 -080083#ifdef CONFIG_NETFILTER
84 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
85#endif
Herbert Xu09b8f7a2006-06-22 03:08:03 -070086
Patrick McHardy679e8982006-07-30 20:19:11 -070087 skb->protocol = htons(ETH_P_IPV6);
Herbert Xu862b82c2007-11-13 21:43:11 -080088 return xfrm_output(skb);
Herbert Xu09b8f7a2006-06-22 03:08:03 -070089}
90
Patrick McHardy16a66772006-01-06 23:01:48 -080091int xfrm6_output(struct sk_buff *skb)
92{
Eric Dumazetadf30902009-06-02 05:19:30 +000093 return NF_HOOK(PF_INET6, NF_INET_POST_ROUTING, skb, NULL, skb_dst(skb)->dev,
Patrick McHardy16a66772006-01-06 23:01:48 -080094 xfrm6_output_finish);
95}