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gerrit-public.fairphone.software / kernel / msm-4.9 / 5596732fa8c14139018ecda8356eabbfb599d830 / . / net / ipv4 / xfrm4_output.c
blob: f3800bf79d86cb4ac856d435b334f126dc2fe6f6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]1/*
2 * xfrm4_output.c - Common IPsec encapsulation code for IPv4.
3 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900[diff] [blame]4 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
Herbert Xu09b8f7a2006-06-22 03:08:03 -0700[diff] [blame]11#include <linux/if_ether.h>
12#include <linux/kernel.h>
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800[diff] [blame]13#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]14#include <linux/skbuff.h>
Patrick McHardy16a66772006-01-06 23:01:48 -0800[diff] [blame]15#include <linux/netfilter_ipv4.h>
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800[diff] [blame]16#include <net/dst.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]17#include <net/ip.h>
18#include <net/xfrm.h>
19#include <net/icmp.h>
20
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]21static int xfrm4_tunnel_check_size(struct sk_buff *skb)
22{
23 int mtu, ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]24
25 if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
26 goto out;
27
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700[diff] [blame]28 if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]29 goto out;
30
Hannes Frederic Sowa5a25cf12013-08-26 12:31:19 +0200[diff] [blame]31 mtu = dst_mtu(skb_dst(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]32 if (skb->len > mtu) {
Steffen Klassertb00897b2011-06-29 23:20:41 +0000[diff] [blame]33 if (skb->sk)
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200[diff] [blame]34 xfrm_local_error(skb, mtu);
Steffen Klassertb00897b2011-06-29 23:20:41 +0000[diff] [blame]35 else
36 icmp_send(skb, ICMP_DEST_UNREACH,
37 ICMP_FRAG_NEEDED, htonl(mtu));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]38 ret = -EMSGSIZE;
39 }
40out:
41 return ret;
42}
43
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800[diff] [blame]44int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]45{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]46 int err;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900[diff] [blame]47
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800[diff] [blame]48 err = xfrm4_tunnel_check_size(skb);
49 if (err)
50 return err;
51
Herbert Xu60d5fcf2007-11-19 18:47:58 -0800[diff] [blame]52 XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
53
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800[diff] [blame]54 return xfrm4_extract_header(skb);
55}
56
57int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
58{
59 int err;
60
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700[diff] [blame]61 err = xfrm_inner_extract_output(x, skb);
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800[diff] [blame]62 if (err)
63 return err;
64
Steffen Klassert55967322014-04-07 08:08:52 +0200[diff] [blame^]65 IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
Herbert Xu36cf9ac2007-11-13 21:40:52 -0800[diff] [blame]66
67 return x->outer_mode->output2(x, skb);
68}
69EXPORT_SYMBOL(xfrm4_prepare_output);
70
Steffen Klassert43a4dea2011-05-09 19:36:38 +0000[diff] [blame]71int xfrm4_output_finish(struct sk_buff *skb)
Herbert Xu09b8f7a2006-06-22 03:08:03 -0700[diff] [blame]72{
Steffen Klassert55967322014-04-07 08:08:52 +0200[diff] [blame^]73 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
74 skb->protocol = htons(ETH_P_IP);
Herbert Xu862b82c2007-11-13 21:43:11 -0800[diff] [blame]75
Steffen Klassert55967322014-04-07 08:08:52 +0200[diff] [blame^]76#ifdef CONFIG_NETFILTER
Herbert Xu862b82c2007-11-13 21:43:11 -0800[diff] [blame]77 IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
Herbert Xu09b8f7a2006-06-22 03:08:03 -0700[diff] [blame]78#endif
79
Herbert Xu862b82c2007-11-13 21:43:11 -0800[diff] [blame]80 return xfrm_output(skb);
Herbert Xu09b8f7a2006-06-22 03:08:03 -0700[diff] [blame]81}
82
Steffen Klassert55967322014-04-07 08:08:52 +0200[diff] [blame^]83static int __xfrm4_output(struct sk_buff *skb)
84{
85 struct xfrm_state *x = skb_dst(skb)->xfrm;
86
87#ifdef CONFIG_NETFILTER
88 if (!x) {
89 IPCB(skb)->flags |= IPSKB_REROUTED;
90 return dst_output(skb);
91 }
92#endif
93
94 return x->outer_mode->afinfo->output_finish(skb);
95}
96
Patrick McHardy16a66772006-01-06 23:01:48 -0800[diff] [blame]97int xfrm4_output(struct sk_buff *skb)
98{
Jan Engelhardt9bbc7682010-03-23 04:07:29 +0100[diff] [blame]99 return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb,
Steffen Klassert55967322014-04-07 08:08:52 +0200[diff] [blame^]100 NULL, skb_dst(skb)->dev, __xfrm4_output,
Patrick McHardy48d5cad2006-02-15 15:10:22 -0800[diff] [blame]101 !(IPCB(skb)->flags & IPSKB_REROUTED));
Patrick McHardy16a66772006-01-06 23:01:48 -0800[diff] [blame]102}
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200[diff] [blame]103
104void xfrm4_local_error(struct sk_buff *skb, u32 mtu)
105{
106 struct iphdr *hdr;
107
108 hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
109 ip_local_error(skb->sk, EMSGSIZE, hdr->daddr,
110 inet_sk(skb->sk)->inet_dport, mtu);
111}