blob: 8755a3079d0f3279255e54520fbfcdeb19a2006b [file] [log] [blame]
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>
David Stevensad0081e2010-12-17 11:42:42 +000020#include <net/ip6_route.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <net/xfrm.h>
22
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -070023int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
24 u8 **prevhdr)
25{
26 return ip6_find_1stfragopt(skb, prevhdr);
27}
28
YOSHIFUJI Hideaki71590392007-02-22 22:05:40 +090029EXPORT_SYMBOL(xfrm6_find_1stfragopt);
30
Steffen Klassertdd767852011-10-11 01:44:30 +000031static int xfrm6_local_dontfrag(struct sk_buff *skb)
32{
33 int proto;
34 struct sock *sk = skb->sk;
35
36 if (sk) {
37 proto = sk->sk_protocol;
38
39 if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
40 return inet6_sk(sk)->dontfrag;
41 }
42
43 return 0;
44}
45
46static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
47{
48 struct flowi6 fl6;
49 struct sock *sk = skb->sk;
50
51 fl6.flowi6_oif = sk->sk_bound_dev_if;
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +000052 fl6.daddr = ipv6_hdr(skb)->daddr;
Steffen Klassertdd767852011-10-11 01:44:30 +000053
54 ipv6_local_rxpmtu(sk, &fl6, mtu);
55}
56
57static void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
58{
59 struct flowi6 fl6;
60 struct sock *sk = skb->sk;
61
62 fl6.fl6_dport = inet_sk(sk)->inet_dport;
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +000063 fl6.daddr = ipv6_hdr(skb)->daddr;
Steffen Klassertdd767852011-10-11 01:44:30 +000064
65 ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
66}
67
Linus Torvalds1da177e2005-04-16 15:20:36 -070068static int xfrm6_tunnel_check_size(struct sk_buff *skb)
69{
70 int mtu, ret = 0;
Eric Dumazetadf30902009-06-02 05:19:30 +000071 struct dst_entry *dst = skb_dst(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 mtu = dst_mtu(dst);
74 if (mtu < IPV6_MIN_MTU)
75 mtu = IPV6_MIN_MTU;
76
Herbert Xu28a894532008-02-12 18:07:27 -080077 if (!skb->local_df && skb->len > mtu) {
Herbert Xu180e4252005-05-23 13:11:07 -070078 skb->dev = dst->dev;
Steffen Klassertdd767852011-10-11 01:44:30 +000079
80 if (xfrm6_local_dontfrag(skb))
81 xfrm6_local_rxpmtu(skb, mtu);
82 else if (skb->sk)
83 xfrm6_local_error(skb, mtu);
84 else
85 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 ret = -EMSGSIZE;
87 }
88
89 return ret;
90}
91
Herbert Xu36cf9ac2007-11-13 21:40:52 -080092int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 int err;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090095
Herbert Xu36cf9ac2007-11-13 21:40:52 -080096 err = xfrm6_tunnel_check_size(skb);
97 if (err)
98 return err;
99
Herbert Xu60d5fcf2007-11-19 18:47:58 -0800100 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
101
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800102 return xfrm6_extract_header(skb);
103}
104
105int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
106{
107 int err;
108
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700109 err = xfrm_inner_extract_output(x, skb);
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800110 if (err)
111 return err;
112
113 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
Herbert Xu862b82c2007-11-13 21:43:11 -0800114#ifdef CONFIG_NETFILTER
115 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
116#endif
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800117
118 skb->protocol = htons(ETH_P_IPV6);
Steffen Klassertd1d88e5d2009-04-06 03:58:50 +0000119 skb->local_df = 1;
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800120
121 return x->outer_mode->output2(x, skb);
122}
123EXPORT_SYMBOL(xfrm6_prepare_output);
124
Steffen Klassert43a4dea2011-05-09 19:36:38 +0000125int xfrm6_output_finish(struct sk_buff *skb)
Herbert Xu09b8f7a2006-06-22 03:08:03 -0700126{
Herbert Xu862b82c2007-11-13 21:43:11 -0800127#ifdef CONFIG_NETFILTER
128 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
129#endif
Herbert Xu09b8f7a2006-06-22 03:08:03 -0700130
Patrick McHardy679e8982006-07-30 20:19:11 -0700131 skb->protocol = htons(ETH_P_IPV6);
Herbert Xu862b82c2007-11-13 21:43:11 -0800132 return xfrm_output(skb);
Herbert Xu09b8f7a2006-06-22 03:08:03 -0700133}
134
David Stevensad0081e2010-12-17 11:42:42 +0000135static int __xfrm6_output(struct sk_buff *skb)
136{
137 struct dst_entry *dst = skb_dst(skb);
138 struct xfrm_state *x = dst->xfrm;
Steffen Klassertdd767852011-10-11 01:44:30 +0000139 int mtu = ip6_skb_dst_mtu(skb);
140
141 if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
142 xfrm6_local_rxpmtu(skb, mtu);
143 return -EMSGSIZE;
144 } else if (!skb->local_df && skb->len > mtu && skb->sk) {
145 xfrm6_local_error(skb, mtu);
146 return -EMSGSIZE;
147 }
David Stevensad0081e2010-12-17 11:42:42 +0000148
Dan Carpenter5b11b2e2012-01-31 21:45:26 +0000149 if (x->props.mode == XFRM_MODE_TUNNEL &&
Steffen Klassertdd767852011-10-11 01:44:30 +0000150 ((skb->len > mtu && !skb_is_gso(skb)) ||
David Stevensad0081e2010-12-17 11:42:42 +0000151 dst_allfrag(skb_dst(skb)))) {
Steffen Klassert43a4dea2011-05-09 19:36:38 +0000152 return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
David Stevensad0081e2010-12-17 11:42:42 +0000153 }
Steffen Klassert43a4dea2011-05-09 19:36:38 +0000154 return x->outer_mode->afinfo->output_finish(skb);
David Stevensad0081e2010-12-17 11:42:42 +0000155}
156
Patrick McHardy16a66772006-01-06 23:01:48 -0800157int xfrm6_output(struct sk_buff *skb)
158{
Jan Engelhardtb2e0b382010-03-23 04:09:07 +0100159 return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
David Stevensad0081e2010-12-17 11:42:42 +0000160 skb_dst(skb)->dev, __xfrm6_output);
Patrick McHardy16a66772006-01-06 23:01:48 -0800161}