Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * xfrm4_output.c - Common IPsec encapsulation code for IPv4. | |
3 | * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au> | |
e905a9ed | 4 | * |
1da177e4 LT |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation; either version | |
8 | * 2 of the License, or (at your option) any later version. | |
9 | */ | |
10 | ||
09b8f7a9 HX |
11 | #include <linux/if_ether.h> |
12 | #include <linux/kernel.h> | |
36cf9acf | 13 | #include <linux/module.h> |
1da177e4 | 14 | #include <linux/skbuff.h> |
16a6677f | 15 | #include <linux/netfilter_ipv4.h> |
36cf9acf | 16 | #include <net/dst.h> |
1da177e4 LT |
17 | #include <net/ip.h> |
18 | #include <net/xfrm.h> | |
19 | #include <net/icmp.h> | |
20 | ||
1da177e4 LT |
21 | static int xfrm4_tunnel_check_size(struct sk_buff *skb) |
22 | { | |
23 | int mtu, ret = 0; | |
24 | struct dst_entry *dst; | |
1da177e4 LT |
25 | |
26 | if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE) | |
27 | goto out; | |
28 | ||
eddc9ec5 | 29 | if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df) |
1da177e4 LT |
30 | goto out; |
31 | ||
adf30907 | 32 | dst = skb_dst(skb); |
1da177e4 LT |
33 | mtu = dst_mtu(dst); |
34 | if (skb->len > mtu) { | |
b00897b8 SK |
35 | if (skb->sk) |
36 | ip_local_error(skb->sk, EMSGSIZE, ip_hdr(skb)->daddr, | |
37 | inet_sk(skb->sk)->inet_dport, mtu); | |
38 | else | |
39 | icmp_send(skb, ICMP_DEST_UNREACH, | |
40 | ICMP_FRAG_NEEDED, htonl(mtu)); | |
1da177e4 LT |
41 | ret = -EMSGSIZE; |
42 | } | |
43 | out: | |
44 | return ret; | |
45 | } | |
46 | ||
36cf9acf HX |
47 | int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb) |
48 | { | |
49 | int err; | |
50 | ||
51 | err = xfrm4_tunnel_check_size(skb); | |
52 | if (err) | |
53 | return err; | |
54 | ||
60d5fcfb HX |
55 | XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol; |
56 | ||
36cf9acf HX |
57 | return xfrm4_extract_header(skb); |
58 | } | |
59 | ||
60 | int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb) | |
61 | { | |
62 | int err; | |
63 | ||
df9dcb45 | 64 | err = xfrm_inner_extract_output(x, skb); |
36cf9acf HX |
65 | if (err) |
66 | return err; | |
67 | ||
68 | memset(IPCB(skb), 0, sizeof(*IPCB(skb))); | |
862b82c6 | 69 | IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED; |
36cf9acf HX |
70 | |
71 | skb->protocol = htons(ETH_P_IP); | |
72 | ||
73 | return x->outer_mode->output2(x, skb); | |
74 | } | |
75 | EXPORT_SYMBOL(xfrm4_prepare_output); | |
76 | ||
43a4dea4 | 77 | int xfrm4_output_finish(struct sk_buff *skb) |
09b8f7a9 | 78 | { |
09b8f7a9 | 79 | #ifdef CONFIG_NETFILTER |
adf30907 | 80 | if (!skb_dst(skb)->xfrm) { |
09b8f7a9 HX |
81 | IPCB(skb)->flags |= IPSKB_REROUTED; |
82 | return dst_output(skb); | |
83 | } | |
09b8f7a9 | 84 | |
862b82c6 HX |
85 | IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED; |
86 | #endif | |
09b8f7a9 HX |
87 | |
88 | skb->protocol = htons(ETH_P_IP); | |
862b82c6 | 89 | return xfrm_output(skb); |
09b8f7a9 HX |
90 | } |
91 | ||
16a6677f PM |
92 | int xfrm4_output(struct sk_buff *skb) |
93 | { | |
43a4dea4 SK |
94 | struct dst_entry *dst = skb_dst(skb); |
95 | struct xfrm_state *x = dst->xfrm; | |
96 | ||
9bbc768a | 97 | return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, |
43a4dea4 SK |
98 | NULL, dst->dev, |
99 | x->outer_mode->afinfo->output_finish, | |
48d5cad8 | 100 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
16a6677f | 101 | } |