mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 16:24:13 +08:00
b59f45d0b2
This patch adds the structure xfrm_mode. It is meant to represent the operations carried out by transport/tunnel modes. By doing this we allow additional encapsulation modes to be added without clogging up the xfrm_input/xfrm_output paths. Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and BEET modes. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
136 lines
2.7 KiB
C
136 lines
2.7 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/compiler.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/netfilter_ipv4.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;
|
|
struct dst_entry *dst;
|
|
struct iphdr *iph = skb->nh.iph;
|
|
|
|
if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
|
|
goto out;
|
|
|
|
IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
|
|
|
|
if (!(iph->frag_off & htons(IP_DF)) || skb->local_df)
|
|
goto out;
|
|
|
|
dst = skb->dst;
|
|
mtu = dst_mtu(dst);
|
|
if (skb->len > mtu) {
|
|
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
|
|
ret = -EMSGSIZE;
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int xfrm4_output_one(struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb->dst;
|
|
struct xfrm_state *x = dst->xfrm;
|
|
int err;
|
|
|
|
if (skb->ip_summed == CHECKSUM_HW) {
|
|
err = skb_checksum_help(skb, 0);
|
|
if (err)
|
|
goto error_nolock;
|
|
}
|
|
|
|
if (x->props.mode) {
|
|
err = xfrm4_tunnel_check_size(skb);
|
|
if (err)
|
|
goto error_nolock;
|
|
}
|
|
|
|
do {
|
|
spin_lock_bh(&x->lock);
|
|
err = xfrm_state_check(x, skb);
|
|
if (err)
|
|
goto error;
|
|
|
|
err = x->mode->output(skb);
|
|
if (err)
|
|
goto error;
|
|
|
|
err = x->type->output(x, skb);
|
|
if (err)
|
|
goto error;
|
|
|
|
x->curlft.bytes += skb->len;
|
|
x->curlft.packets++;
|
|
|
|
spin_unlock_bh(&x->lock);
|
|
|
|
if (!(skb->dst = dst_pop(dst))) {
|
|
err = -EHOSTUNREACH;
|
|
goto error_nolock;
|
|
}
|
|
dst = skb->dst;
|
|
x = dst->xfrm;
|
|
} while (x && !x->props.mode);
|
|
|
|
IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
|
|
err = 0;
|
|
|
|
out_exit:
|
|
return err;
|
|
error:
|
|
spin_unlock_bh(&x->lock);
|
|
error_nolock:
|
|
kfree_skb(skb);
|
|
goto out_exit;
|
|
}
|
|
|
|
static int xfrm4_output_finish(struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
if (!skb->dst->xfrm) {
|
|
IPCB(skb)->flags |= IPSKB_REROUTED;
|
|
return dst_output(skb);
|
|
}
|
|
#endif
|
|
while (likely((err = xfrm4_output_one(skb)) == 0)) {
|
|
nf_reset(skb);
|
|
|
|
err = nf_hook(PF_INET, NF_IP_LOCAL_OUT, &skb, NULL,
|
|
skb->dst->dev, dst_output);
|
|
if (unlikely(err != 1))
|
|
break;
|
|
|
|
if (!skb->dst->xfrm)
|
|
return dst_output(skb);
|
|
|
|
err = nf_hook(PF_INET, NF_IP_POST_ROUTING, &skb, NULL,
|
|
skb->dst->dev, xfrm4_output_finish);
|
|
if (unlikely(err != 1))
|
|
break;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
int xfrm4_output(struct sk_buff *skb)
|
|
{
|
|
return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
|
|
xfrm4_output_finish,
|
|
!(IPCB(skb)->flags & IPSKB_REROUTED));
|
|
}
|