Commit | Line | Data |
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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> |
36cf9acf 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 |
23 | int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb, |
24 | u8 **prevhdr) | |
25 | { | |
26 | return ip6_find_1stfragopt(skb, prevhdr); | |
27 | } | |
28 | ||
7159039a YH |
29 | EXPORT_SYMBOL(xfrm6_find_1stfragopt); |
30 | ||
dd767856 SK |
31 | static 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 | ||
46 | static 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; | |
4e3fd7a0 | 52 | fl6.daddr = ipv6_hdr(skb)->daddr; |
dd767856 SK |
53 | |
54 | ipv6_local_rxpmtu(sk, &fl6, mtu); | |
55 | } | |
56 | ||
57 | static 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; | |
4e3fd7a0 | 63 | fl6.daddr = ipv6_hdr(skb)->daddr; |
dd767856 SK |
64 | |
65 | ipv6_local_error(sk, EMSGSIZE, &fl6, mtu); | |
66 | } | |
67 | ||
1da177e4 LT |
68 | static int xfrm6_tunnel_check_size(struct sk_buff *skb) |
69 | { | |
70 | int mtu, ret = 0; | |
adf30907 | 71 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
72 | |
73 | mtu = dst_mtu(dst); | |
74 | if (mtu < IPV6_MIN_MTU) | |
75 | mtu = IPV6_MIN_MTU; | |
76 | ||
28a89453 | 77 | if (!skb->local_df && skb->len > mtu) { |
180e4250 | 78 | skb->dev = dst->dev; |
dd767856 SK |
79 | |
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); | |
1da177e4 LT |
86 | ret = -EMSGSIZE; |
87 | } | |
88 | ||
89 | return ret; | |
90 | } | |
91 | ||
36cf9acf HX |
92 | int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb) |
93 | { | |
94 | int err; | |
95 | ||
96 | err = xfrm6_tunnel_check_size(skb); | |
97 | if (err) | |
98 | return err; | |
99 | ||
60d5fcfb HX |
100 | XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr; |
101 | ||
36cf9acf HX |
102 | return xfrm6_extract_header(skb); |
103 | } | |
104 | ||
105 | int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb) | |
106 | { | |
107 | int err; | |
108 | ||
df9dcb45 | 109 | err = xfrm_inner_extract_output(x, skb); |
36cf9acf HX |
110 | if (err) |
111 | return err; | |
112 | ||
113 | memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); | |
862b82c6 HX |
114 | #ifdef CONFIG_NETFILTER |
115 | IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED; | |
116 | #endif | |
36cf9acf HX |
117 | |
118 | skb->protocol = htons(ETH_P_IPV6); | |
d1d88e5d | 119 | skb->local_df = 1; |
36cf9acf HX |
120 | |
121 | return x->outer_mode->output2(x, skb); | |
122 | } | |
123 | EXPORT_SYMBOL(xfrm6_prepare_output); | |
124 | ||
43a4dea4 | 125 | int xfrm6_output_finish(struct sk_buff *skb) |
09b8f7a9 | 126 | { |
862b82c6 HX |
127 | #ifdef CONFIG_NETFILTER |
128 | IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED; | |
129 | #endif | |
09b8f7a9 | 130 | |
679e898a | 131 | skb->protocol = htons(ETH_P_IPV6); |
862b82c6 | 132 | return xfrm_output(skb); |
09b8f7a9 HX |
133 | } |
134 | ||
ad0081e4 DS |
135 | static int __xfrm6_output(struct sk_buff *skb) |
136 | { | |
137 | struct dst_entry *dst = skb_dst(skb); | |
138 | struct xfrm_state *x = dst->xfrm; | |
dd767856 SK |
139 | 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 | } | |
ad0081e4 | 148 | |
5b11b2e4 | 149 | if (x->props.mode == XFRM_MODE_TUNNEL && |
dd767856 | 150 | ((skb->len > mtu && !skb_is_gso(skb)) || |
ad0081e4 | 151 | dst_allfrag(skb_dst(skb)))) { |
43a4dea4 | 152 | return ip6_fragment(skb, x->outer_mode->afinfo->output_finish); |
ad0081e4 | 153 | } |
43a4dea4 | 154 | return x->outer_mode->afinfo->output_finish(skb); |
ad0081e4 DS |
155 | } |
156 | ||
16a6677f PM |
157 | int xfrm6_output(struct sk_buff *skb) |
158 | { | |
b2e0b385 | 159 | return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, |
ad0081e4 | 160 | skb_dst(skb)->dev, __xfrm6_output); |
16a6677f | 161 | } |