kernel-ark/net/ipv4/xfrm4_mode_tunnel.c
Herbert Xu 1bfcb10f67 [IPSEC]: Add missing BEET checks
Currently BEET mode does not reinject the packet back into the stack
like tunnel mode does.  Since BEET should behave just like tunnel mode
this is incorrect.

This patch fixes this by introducing a flags field to xfrm_mode that
tells the IPsec code whether it should terminate and reinject the packet
back into the stack.

It then sets the flag for BEET and tunnel mode.

I've also added a number of missing BEET checks elsewhere where we check
whether a given mode is a tunnel or not.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-17 21:31:50 -07:00

162 lines
3.8 KiB
C

/*
* xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4.
*
* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/stringify.h>
#include <net/dst.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/xfrm.h>
static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
{
struct iphdr *outer_iph = ip_hdr(skb);
struct iphdr *inner_iph = ipip_hdr(skb);
if (INET_ECN_is_ce(outer_iph->tos))
IP_ECN_set_ce(inner_iph);
}
static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
{
if (INET_ECN_is_ce(iph->tos))
IP6_ECN_set_ce(ipv6_hdr(skb));
}
/* Add encapsulation header.
*
* The top IP header will be constructed per RFC 2401.
*/
static int xfrm4_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
struct iphdr *iph, *top_iph;
int flags;
iph = ip_hdr(skb);
skb_set_network_header(skb, -x->props.header_len);
skb->mac_header = skb->network_header +
offsetof(struct iphdr, protocol);
skb->transport_header = skb->network_header + sizeof(*iph);
top_iph = ip_hdr(skb);
top_iph->ihl = 5;
top_iph->version = 4;
flags = x->props.flags;
/* DS disclosed */
if (xdst->route->ops->family == AF_INET) {
top_iph->protocol = IPPROTO_IPIP;
top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos);
top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
0 : (iph->frag_off & htons(IP_DF));
}
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
else {
struct ipv6hdr *ipv6h = (struct ipv6hdr*)iph;
top_iph->protocol = IPPROTO_IPV6;
top_iph->tos = INET_ECN_encapsulate(iph->tos, ipv6_get_dsfield(ipv6h));
top_iph->frag_off = 0;
}
#endif
if (flags & XFRM_STATE_NOECN)
IP_ECN_clear(top_iph);
if (!top_iph->frag_off)
__ip_select_ident(top_iph, dst->child, 0);
top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);
top_iph->saddr = x->props.saddr.a4;
top_iph->daddr = x->id.daddr.a4;
skb->protocol = htons(ETH_P_IP);
memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
return 0;
}
static int xfrm4_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct iphdr *iph = ip_hdr(skb);
const unsigned char *old_mac;
int err = -EINVAL;
switch (iph->protocol){
case IPPROTO_IPIP:
break;
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
case IPPROTO_IPV6:
break;
#endif
default:
goto out;
}
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto out;
if (skb_cloned(skb) &&
(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
goto out;
iph = ip_hdr(skb);
if (iph->protocol == IPPROTO_IPIP) {
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
ipv4_copy_dscp(iph, ipip_hdr(skb));
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip_ecn_decapsulate(skb);
}
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
else {
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip6_ecn_decapsulate(iph, skb);
skb->protocol = htons(ETH_P_IPV6);
}
#endif
old_mac = skb_mac_header(skb);
skb_set_mac_header(skb, -skb->mac_len);
memmove(skb_mac_header(skb), old_mac, skb->mac_len);
skb_reset_network_header(skb);
err = 0;
out:
return err;
}
static struct xfrm_mode xfrm4_tunnel_mode = {
.input = xfrm4_tunnel_input,
.output = xfrm4_tunnel_output,
.owner = THIS_MODULE,
.encap = XFRM_MODE_TUNNEL,
.flags = XFRM_MODE_FLAG_TUNNEL,
};
static int __init xfrm4_tunnel_init(void)
{
return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET);
}
static void __exit xfrm4_tunnel_exit(void)
{
int err;
err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET);
BUG_ON(err);
}
module_init(xfrm4_tunnel_init);
module_exit(xfrm4_tunnel_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL);