2024-09-09 08:52:07 +00:00
|
|
|
/*
|
|
|
|
|
* xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4.
|
|
|
|
|
*
|
|
|
|
|
* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#include <linux/gfp.h>
|
|
|
|
|
#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 *inner_iph = ipip_hdr(skb);
|
|
|
|
|
|
|
|
|
|
if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
|
|
|
|
|
IP_ECN_set_ce(inner_iph);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Add encapsulation header.
|
|
|
|
|
*
|
|
|
|
|
* The top IP header will be constructed per RFC 2401.
|
|
|
|
|
*/
|
|
|
|
|
static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
|
|
|
{
|
|
|
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
|
|
|
struct iphdr *top_iph;
|
|
|
|
|
int flags;
|
|
|
|
|
|
|
|
|
|
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(*top_iph);
|
|
|
|
|
top_iph = ip_hdr(skb);
|
|
|
|
|
|
|
|
|
|
top_iph->ihl = 5;
|
|
|
|
|
top_iph->version = 4;
|
|
|
|
|
|
|
|
|
|
top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);
|
|
|
|
|
|
2024-09-09 08:57:42 +00:00
|
|
|
/* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
|
|
|
|
|
if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
|
|
|
|
|
top_iph->tos = 0;
|
|
|
|
|
else
|
|
|
|
|
top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
|
|
|
|
|
top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
|
2024-09-09 08:52:07 +00:00
|
|
|
XFRM_MODE_SKB_CB(skb)->tos);
|
|
|
|
|
|
|
|
|
|
flags = x->props.flags;
|
|
|
|
|
if (flags & XFRM_STATE_NOECN)
|
|
|
|
|
IP_ECN_clear(top_iph);
|
|
|
|
|
|
|
|
|
|
top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
|
|
|
|
|
0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
|
|
|
|
|
|
|
|
|
|
top_iph->ttl = ip4_dst_hoplimit(dst->child);
|
|
|
|
|
|
|
|
|
|
top_iph->saddr = x->props.saddr.a4;
|
|
|
|
|
top_iph->daddr = x->id.daddr.a4;
|
2024-09-09 08:57:42 +00:00
|
|
|
ip_select_ident(skb, NULL);
|
2024-09-09 08:52:07 +00:00
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
|
|
|
|
|
{
|
|
|
|
|
int err = -EINVAL;
|
|
|
|
|
|
|
|
|
|
if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
|
|
|
|
|
goto out;
|
|
|
|
|
|
2024-09-09 08:57:42 +00:00
|
|
|
err = skb_unclone(skb, GFP_ATOMIC);
|
|
|
|
|
if (err)
|
2024-09-09 08:52:07 +00:00
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
|
|
|
|
|
ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
|
|
|
|
|
if (!(x->props.flags & XFRM_STATE_NOECN))
|
|
|
|
|
ipip_ecn_decapsulate(skb);
|
|
|
|
|
|
|
|
|
|
skb_reset_network_header(skb);
|
|
|
|
|
skb_mac_header_rebuild(skb);
|
|
|
|
|
|
|
|
|
|
err = 0;
|
|
|
|
|
|
|
|
|
|
out:
|
|
|
|
|
return err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct xfrm_mode xfrm4_tunnel_mode = {
|
|
|
|
|
.input2 = xfrm4_mode_tunnel_input,
|
|
|
|
|
.input = xfrm_prepare_input,
|
|
|
|
|
.output2 = xfrm4_mode_tunnel_output,
|
|
|
|
|
.output = xfrm4_prepare_output,
|
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
|
.encap = XFRM_MODE_TUNNEL,
|
|
|
|
|
.flags = XFRM_MODE_FLAG_TUNNEL,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int __init xfrm4_mode_tunnel_init(void)
|
|
|
|
|
{
|
|
|
|
|
return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void __exit xfrm4_mode_tunnel_exit(void)
|
|
|
|
|
{
|
|
|
|
|
int err;
|
|
|
|
|
|
|
|
|
|
err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET);
|
|
|
|
|
BUG_ON(err);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
module_init(xfrm4_mode_tunnel_init);
|
|
|
|
|
module_exit(xfrm4_mode_tunnel_exit);
|
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
|
MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL);
|
