You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
113 lines
2.7 KiB
113 lines
2.7 KiB
/*
|
|
* 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->ignore_df)
|
|
goto out;
|
|
|
|
mtu = dst_mtu(skb_dst(skb));
|
|
if ((!skb_is_gso(skb) && skb->len > mtu) ||
|
|
(skb_is_gso(skb) && skb_gso_network_seglen(skb) > ip_skb_dst_mtu(skb->sk, skb))) {
|
|
skb->protocol = htons(ETH_P_IP);
|
|
|
|
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;
|
|
skb->protocol = htons(ETH_P_IP);
|
|
|
|
return x->outer_mode->output2(x, skb);
|
|
}
|
|
EXPORT_SYMBOL(xfrm4_prepare_output);
|
|
|
|
int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
|
|
|
|
IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
|
|
|
|
return xfrm_output(sk, skb);
|
|
}
|
|
|
|
static int __xfrm4_output(struct net *net, struct sock *sk, 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(net, sk, skb);
|
|
}
|
|
#endif
|
|
|
|
return x->outer_mode->afinfo->output_finish(sk, skb);
|
|
}
|
|
|
|
int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
|
|
net, sk, 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);
|
|
}
|
|
|