linux/net/ipv4/xfrm4_output.c
David S. Miller f895f0cfbb Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Conflicts:
	net/ipv4/ip_vti.c

Steffen Klassert says:

====================
pull request (net): ipsec 2014-05-15

This pull request has a merge conflict in net/ipv4/ip_vti.c
between commit 8d89dcdf80 ("vti: don't allow to add the same
tunnel twice") and commit a32452366b  ("vti4:Don't count header
length twice"). It can be solved like it is done in linux-next.

1) Fix a ipv6 xfrm output crash when a packet is rerouted
   by netfilter to not use IPsec.

2) vti4 counts some header lengths twice leading to an incorrect
   device mtu. Fix this by counting these headers only once.

3) We don't catch the case if an unsupported protocol is submitted
   to the xfrm protocol handlers, this can lead to NULL pointer
   dereferences. Fix this by adding the appropriate checks.

4) vti6 may unregister pernet ops twice on init errors.
   Fix this by removing one of the calls to do it only once.
   From Mathias Krause.

5) Set the vti tunnel mark before doing a lookup in the error
   handlers. Otherwise we don't find the correct xfrm state.
====================

The conflict in ip_vti.c was simple, 'net' had a commit
removing a line from vti_tunnel_init() and this tree
being merged had a commit adding a line to the same
location.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-15 23:23:48 -04:00

112 lines
2.4 KiB
C

/*
* xfrm4_output.c - Common IPsec encapsulation code for IPv4.
* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/if_ether.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter_ipv4.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/icmp.h>
static int xfrm4_tunnel_check_size(struct sk_buff *skb)
{
int mtu, ret = 0;
if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
goto out;
if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
goto out;
mtu = dst_mtu(skb_dst(skb));
if (skb->len > mtu) {
if (skb->sk)
xfrm_local_error(skb, mtu);
else
icmp_send(skb, ICMP_DEST_UNREACH,
ICMP_FRAG_NEEDED, htonl(mtu));
ret = -EMSGSIZE;
}
out:
return ret;
}
int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
err = xfrm4_tunnel_check_size(skb);
if (err)
return err;
XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
return xfrm4_extract_header(skb);
}
int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
err = xfrm_inner_extract_output(x, skb);
if (err)
return err;
IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
return x->outer_mode->output2(x, skb);
}
EXPORT_SYMBOL(xfrm4_prepare_output);
int xfrm4_output_finish(struct sk_buff *skb)
{
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
skb->protocol = htons(ETH_P_IP);
#ifdef CONFIG_NETFILTER
IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
#endif
return xfrm_output(skb);
}
static int __xfrm4_output(struct sk_buff *skb)
{
struct xfrm_state *x = skb_dst(skb)->xfrm;
#ifdef CONFIG_NETFILTER
if (!x) {
IPCB(skb)->flags |= IPSKB_REROUTED;
return dst_output(skb);
}
#endif
return x->outer_mode->afinfo->output_finish(skb);
}
int xfrm4_output(struct sock *sk, struct sk_buff *skb)
{
return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb,
NULL, skb_dst(skb)->dev, __xfrm4_output,
!(IPCB(skb)->flags & IPSKB_REROUTED));
}
void xfrm4_local_error(struct sk_buff *skb, u32 mtu)
{
struct iphdr *hdr;
hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
ip_local_error(skb->sk, EMSGSIZE, hdr->daddr,
inet_sk(skb->sk)->inet_dport, mtu);
}