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) { | |
628e341f HFS |
37 | if (sk->sk_family != AF_INET6) |
38 | return 0; | |
dd767856 | 39 | |
628e341f | 40 | proto = sk->sk_protocol; |
dd767856 SK |
41 | if (proto == IPPROTO_UDP || proto == IPPROTO_RAW) |
42 | return inet6_sk(sk)->dontfrag; | |
43 | } | |
44 | ||
45 | return 0; | |
46 | } | |
47 | ||
48 | static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu) | |
49 | { | |
50 | struct flowi6 fl6; | |
51 | struct sock *sk = skb->sk; | |
52 | ||
53 | fl6.flowi6_oif = sk->sk_bound_dev_if; | |
4e3fd7a0 | 54 | fl6.daddr = ipv6_hdr(skb)->daddr; |
dd767856 SK |
55 | |
56 | ipv6_local_rxpmtu(sk, &fl6, mtu); | |
57 | } | |
58 | ||
628e341f | 59 | void xfrm6_local_error(struct sk_buff *skb, u32 mtu) |
dd767856 SK |
60 | { |
61 | struct flowi6 fl6; | |
5d0ff542 | 62 | const struct ipv6hdr *hdr; |
dd767856 SK |
63 | struct sock *sk = skb->sk; |
64 | ||
5d0ff542 | 65 | hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb); |
dd767856 | 66 | fl6.fl6_dport = inet_sk(sk)->inet_dport; |
5d0ff542 | 67 | fl6.daddr = hdr->daddr; |
dd767856 SK |
68 | |
69 | ipv6_local_error(sk, EMSGSIZE, &fl6, mtu); | |
70 | } | |
71 | ||
1da177e4 LT |
72 | static int xfrm6_tunnel_check_size(struct sk_buff *skb) |
73 | { | |
74 | int mtu, ret = 0; | |
adf30907 | 75 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
76 | |
77 | mtu = dst_mtu(dst); | |
78 | if (mtu < IPV6_MIN_MTU) | |
79 | mtu = IPV6_MIN_MTU; | |
80 | ||
60ff7467 | 81 | if (!skb->ignore_df && skb->len > mtu) { |
180e4250 | 82 | skb->dev = dst->dev; |
dd767856 SK |
83 | |
84 | if (xfrm6_local_dontfrag(skb)) | |
85 | xfrm6_local_rxpmtu(skb, mtu); | |
86 | else if (skb->sk) | |
628e341f | 87 | xfrm_local_error(skb, mtu); |
dd767856 SK |
88 | else |
89 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); | |
1da177e4 LT |
90 | ret = -EMSGSIZE; |
91 | } | |
92 | ||
93 | return ret; | |
94 | } | |
95 | ||
36cf9acf HX |
96 | int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb) |
97 | { | |
98 | int err; | |
99 | ||
100 | err = xfrm6_tunnel_check_size(skb); | |
101 | if (err) | |
102 | return err; | |
103 | ||
60d5fcfb HX |
104 | XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr; |
105 | ||
36cf9acf HX |
106 | return xfrm6_extract_header(skb); |
107 | } | |
108 | ||
109 | int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb) | |
110 | { | |
111 | int err; | |
112 | ||
df9dcb45 | 113 | err = xfrm_inner_extract_output(x, skb); |
36cf9acf HX |
114 | if (err) |
115 | return err; | |
116 | ||
60ff7467 | 117 | skb->ignore_df = 1; |
36cf9acf HX |
118 | |
119 | return x->outer_mode->output2(x, skb); | |
120 | } | |
121 | EXPORT_SYMBOL(xfrm6_prepare_output); | |
122 | ||
43a4dea4 | 123 | int xfrm6_output_finish(struct sk_buff *skb) |
09b8f7a9 | 124 | { |
5596732f SK |
125 | memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); |
126 | skb->protocol = htons(ETH_P_IPV6); | |
127 | ||
862b82c6 HX |
128 | #ifdef CONFIG_NETFILTER |
129 | IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED; | |
130 | #endif | |
09b8f7a9 | 131 | |
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; | |
5a25cf1e | 139 | int mtu; |
0ea9d5e3 | 140 | |
5596732f SK |
141 | #ifdef CONFIG_NETFILTER |
142 | if (!x) { | |
143 | IP6CB(skb)->flags |= IP6SKB_REROUTED; | |
144 | return dst_output(skb); | |
145 | } | |
146 | #endif | |
147 | ||
5a25cf1e HFS |
148 | if (skb->protocol == htons(ETH_P_IPV6)) |
149 | mtu = ip6_skb_dst_mtu(skb); | |
150 | else | |
151 | mtu = dst_mtu(skb_dst(skb)); | |
dd767856 SK |
152 | |
153 | if (skb->len > mtu && xfrm6_local_dontfrag(skb)) { | |
154 | xfrm6_local_rxpmtu(skb, mtu); | |
155 | return -EMSGSIZE; | |
60ff7467 | 156 | } else if (!skb->ignore_df && skb->len > mtu && skb->sk) { |
628e341f | 157 | xfrm_local_error(skb, mtu); |
dd767856 SK |
158 | return -EMSGSIZE; |
159 | } | |
ad0081e4 | 160 | |
5b11b2e4 | 161 | if (x->props.mode == XFRM_MODE_TUNNEL && |
dd767856 | 162 | ((skb->len > mtu && !skb_is_gso(skb)) || |
ad0081e4 | 163 | dst_allfrag(skb_dst(skb)))) { |
43a4dea4 | 164 | return ip6_fragment(skb, x->outer_mode->afinfo->output_finish); |
ad0081e4 | 165 | } |
43a4dea4 | 166 | return x->outer_mode->afinfo->output_finish(skb); |
ad0081e4 DS |
167 | } |
168 | ||
aad88724 | 169 | int xfrm6_output(struct sock *sk, struct sk_buff *skb) |
16a6677f | 170 | { |
5596732f SK |
171 | return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, |
172 | NULL, skb_dst(skb)->dev, __xfrm6_output, | |
173 | !(IP6CB(skb)->flags & IP6SKB_REROUTED)); | |
16a6677f | 174 | } |