Merge tag 'for-linus-20150422' of git://git.infradead.org/linux-mtd
[linux-2.6-block.git] / net / ipv6 / xfrm6_output.c
CommitLineData
1da177e4
LT
1/*
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>
1ab1457c 5 *
1da177e4
LT
6 * 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
406ef77c 12#include <linux/if_ether.h>
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HX
13#include <linux/kernel.h>
14#include <linux/module.h>
1da177e4 15#include <linux/skbuff.h>
1da177e4 16#include <linux/icmpv6.h>
16a6677f 17#include <linux/netfilter_ipv6.h>
36cf9acf 18#include <net/dst.h>
1da177e4 19#include <net/ipv6.h>
ad0081e4 20#include <net/ip6_route.h>
1da177e4
LT
21#include <net/xfrm.h>
22
aee5adb4
MN
23int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
24 u8 **prevhdr)
25{
26 return ip6_find_1stfragopt(skb, prevhdr);
27}
7159039a
YH
28EXPORT_SYMBOL(xfrm6_find_1stfragopt);
29
dd767856
SK
30static int xfrm6_local_dontfrag(struct sk_buff *skb)
31{
32 int proto;
33 struct sock *sk = skb->sk;
34
35 if (sk) {
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HFS
36 if (sk->sk_family != AF_INET6)
37 return 0;
dd767856 38
628e341f 39 proto = sk->sk_protocol;
dd767856
SK
40 if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
41 return inet6_sk(sk)->dontfrag;
42 }
43
44 return 0;
45}
46
47static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
48{
49 struct flowi6 fl6;
50 struct sock *sk = skb->sk;
51
52 fl6.flowi6_oif = sk->sk_bound_dev_if;
4e3fd7a0 53 fl6.daddr = ipv6_hdr(skb)->daddr;
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54
55 ipv6_local_rxpmtu(sk, &fl6, mtu);
56}
57
628e341f 58void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
dd767856
SK
59{
60 struct flowi6 fl6;
5d0ff542 61 const struct ipv6hdr *hdr;
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SK
62 struct sock *sk = skb->sk;
63
5d0ff542 64 hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
dd767856 65 fl6.fl6_dport = inet_sk(sk)->inet_dport;
5d0ff542 66 fl6.daddr = hdr->daddr;
dd767856
SK
67
68 ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
69}
70
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LT
71static int xfrm6_tunnel_check_size(struct sk_buff *skb)
72{
73 int mtu, ret = 0;
adf30907 74 struct dst_entry *dst = skb_dst(skb);
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LT
75
76 mtu = dst_mtu(dst);
77 if (mtu < IPV6_MIN_MTU)
78 mtu = IPV6_MIN_MTU;
79
60ff7467 80 if (!skb->ignore_df && skb->len > mtu) {
180e4250 81 skb->dev = dst->dev;
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SK
82
83 if (xfrm6_local_dontfrag(skb))
84 xfrm6_local_rxpmtu(skb, mtu);
85 else if (skb->sk)
628e341f 86 xfrm_local_error(skb, mtu);
dd767856
SK
87 else
88 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
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89 ret = -EMSGSIZE;
90 }
91
92 return ret;
93}
94
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HX
95int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
96{
97 int err;
98
99 err = xfrm6_tunnel_check_size(skb);
100 if (err)
101 return err;
102
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103 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
104
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105 return xfrm6_extract_header(skb);
106}
107
108int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
109{
110 int err;
111
df9dcb45 112 err = xfrm_inner_extract_output(x, skb);
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HX
113 if (err)
114 return err;
115
60ff7467 116 skb->ignore_df = 1;
044a832a 117 skb->protocol = htons(ETH_P_IPV6);
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HX
118
119 return x->outer_mode->output2(x, skb);
120}
121EXPORT_SYMBOL(xfrm6_prepare_output);
122
7026b1dd 123int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
09b8f7a9 124{
5596732f 125 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
5596732f 126
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HX
127#ifdef CONFIG_NETFILTER
128 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
129#endif
09b8f7a9 130
7026b1dd 131 return xfrm_output(sk, skb);
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HX
132}
133
7026b1dd 134static int __xfrm6_output(struct sock *sk, struct sk_buff *skb)
ad0081e4
DS
135{
136 struct dst_entry *dst = skb_dst(skb);
137 struct xfrm_state *x = dst->xfrm;
5a25cf1e 138 int mtu;
0ea9d5e3 139
5596732f
SK
140#ifdef CONFIG_NETFILTER
141 if (!x) {
142 IP6CB(skb)->flags |= IP6SKB_REROUTED;
7026b1dd 143 return dst_output_sk(sk, skb);
5596732f
SK
144 }
145#endif
146
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HFS
147 if (skb->protocol == htons(ETH_P_IPV6))
148 mtu = ip6_skb_dst_mtu(skb);
149 else
150 mtu = dst_mtu(skb_dst(skb));
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SK
151
152 if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
153 xfrm6_local_rxpmtu(skb, mtu);
154 return -EMSGSIZE;
60ff7467 155 } else if (!skb->ignore_df && skb->len > mtu && skb->sk) {
628e341f 156 xfrm_local_error(skb, mtu);
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SK
157 return -EMSGSIZE;
158 }
ad0081e4 159
5b11b2e4 160 if (x->props.mode == XFRM_MODE_TUNNEL &&
dd767856 161 ((skb->len > mtu && !skb_is_gso(skb)) ||
ad0081e4 162 dst_allfrag(skb_dst(skb)))) {
7026b1dd
DM
163 return ip6_fragment(sk, skb,
164 x->outer_mode->afinfo->output_finish);
ad0081e4 165 }
7026b1dd 166 return x->outer_mode->afinfo->output_finish(sk, skb);
ad0081e4
DS
167}
168
aad88724 169int xfrm6_output(struct sock *sk, struct sk_buff *skb)
16a6677f 170{
7026b1dd 171 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, sk, skb,
5596732f
SK
172 NULL, skb_dst(skb)->dev, __xfrm6_output,
173 !(IP6CB(skb)->flags & IP6SKB_REROUTED));
16a6677f 174}