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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;
33 struct dst_entry *dst = skb->dst;
34
35 mtu = dst_mtu(dst);
36 if (mtu < IPV6_MIN_MTU)
37 mtu = IPV6_MIN_MTU;
38
39 if (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
65 err = x->inner_mode->afinfo->extract_output(x, skb);
66 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);
75
76 return x->outer_mode->output2(x, skb);
77}
78EXPORT_SYMBOL(xfrm6_prepare_output);
79
Herbert Xu09b8f7a2006-06-22 03:08:03 -070080static int xfrm6_output_finish(struct sk_buff *skb)
81{
Herbert Xu862b82c2007-11-13 21:43:11 -080082#ifdef CONFIG_NETFILTER
83 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
84#endif
Herbert Xu09b8f7a2006-06-22 03:08:03 -070085
Patrick McHardy679e8982006-07-30 20:19:11 -070086 skb->protocol = htons(ETH_P_IPV6);
Herbert Xu862b82c2007-11-13 21:43:11 -080087 return xfrm_output(skb);
Herbert Xu09b8f7a2006-06-22 03:08:03 -070088}
89
Patrick McHardy16a66772006-01-06 23:01:48 -080090int xfrm6_output(struct sk_buff *skb)
91{
Patrick McHardy6e23ae22007-11-19 18:53:30 -080092 return NF_HOOK(PF_INET6, NF_INET_POST_ROUTING, skb, NULL, skb->dst->dev,
Patrick McHardy16a66772006-01-06 23:01:48 -080093 xfrm6_output_finish);
94}