147 lines
4.1 KiB
C
147 lines
4.1 KiB
C
/*
|
|
* xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
|
|
*
|
|
* Copyright (C) 2002 USAGI/WIDE Project
|
|
* 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/dsfield.h>
|
|
#include <net/dst.h>
|
|
#include <net/inet_ecn.h>
|
|
#include <net/ipv6.h>
|
|
#include <net/xfrm.h>
|
|
|
|
static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
|
|
{
|
|
struct ipv6hdr *outer_iph = ipv6_hdr(skb);
|
|
struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
|
|
|
|
if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
|
|
IP6_ECN_set_ce(inner_iph);
|
|
}
|
|
|
|
static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb)
|
|
{
|
|
if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6_hdr(skb))))
|
|
IP_ECN_set_ce(ipip_hdr(skb));
|
|
}
|
|
|
|
/* Add encapsulation header.
|
|
*
|
|
* The top IP header will be constructed per RFC 2401. The following fields
|
|
* in it shall be filled in by x->type->output:
|
|
* payload_len
|
|
*
|
|
* On exit, skb->h will be set to the start of the encapsulation header to be
|
|
* filled in by x->type->output and skb->nh will be set to the nextheader field
|
|
* of the extension header directly preceding the encapsulation header, or in
|
|
* its absence, that of the top IP header. The value of skb->data will always
|
|
* point to the top IP header.
|
|
*/
|
|
static int xfrm6_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 ipv6hdr *iph, *top_iph;
|
|
int dsfield;
|
|
|
|
skb_push(skb, x->props.header_len);
|
|
iph = ipv6_hdr(skb);
|
|
|
|
skb_reset_network_header(skb);
|
|
top_iph = ipv6_hdr(skb);
|
|
skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
|
|
skb->network_header += offsetof(struct ipv6hdr, nexthdr);
|
|
|
|
top_iph->version = 6;
|
|
if (xdst->route->ops->family == AF_INET6) {
|
|
top_iph->priority = iph->priority;
|
|
top_iph->flow_lbl[0] = iph->flow_lbl[0];
|
|
top_iph->flow_lbl[1] = iph->flow_lbl[1];
|
|
top_iph->flow_lbl[2] = iph->flow_lbl[2];
|
|
top_iph->nexthdr = IPPROTO_IPV6;
|
|
} else {
|
|
top_iph->priority = 0;
|
|
top_iph->flow_lbl[0] = 0;
|
|
top_iph->flow_lbl[1] = 0;
|
|
top_iph->flow_lbl[2] = 0;
|
|
top_iph->nexthdr = IPPROTO_IPIP;
|
|
}
|
|
dsfield = ipv6_get_dsfield(top_iph);
|
|
dsfield = INET_ECN_encapsulate(dsfield, dsfield);
|
|
if (x->props.flags & XFRM_STATE_NOECN)
|
|
dsfield &= ~INET_ECN_MASK;
|
|
ipv6_change_dsfield(top_iph, 0, dsfield);
|
|
top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
|
|
ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
|
|
ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
|
|
return 0;
|
|
}
|
|
|
|
static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
int err = -EINVAL;
|
|
const unsigned char *old_mac;
|
|
const unsigned char *nh = skb_network_header(skb);
|
|
|
|
if (nh[IP6CB(skb)->nhoff] != IPPROTO_IPV6 &&
|
|
nh[IP6CB(skb)->nhoff] != IPPROTO_IPIP)
|
|
goto out;
|
|
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
|
|
goto out;
|
|
|
|
if (skb_cloned(skb) &&
|
|
(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
|
|
goto out;
|
|
|
|
nh = skb_network_header(skb);
|
|
if (nh[IP6CB(skb)->nhoff] == IPPROTO_IPV6) {
|
|
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
|
|
ipv6_copy_dscp(ipv6_hdr(skb), ipipv6_hdr(skb));
|
|
if (!(x->props.flags & XFRM_STATE_NOECN))
|
|
ipip6_ecn_decapsulate(skb);
|
|
} else {
|
|
if (!(x->props.flags & XFRM_STATE_NOECN))
|
|
ip6ip_ecn_decapsulate(skb);
|
|
skb->protocol = htons(ETH_P_IP);
|
|
}
|
|
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 xfrm6_tunnel_mode = {
|
|
.input = xfrm6_tunnel_input,
|
|
.output = xfrm6_tunnel_output,
|
|
.owner = THIS_MODULE,
|
|
.encap = XFRM_MODE_TUNNEL,
|
|
};
|
|
|
|
static int __init xfrm6_tunnel_init(void)
|
|
{
|
|
return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
|
|
}
|
|
|
|
static void __exit xfrm6_tunnel_exit(void)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
|
|
BUG_ON(err);
|
|
}
|
|
|
|
module_init(xfrm6_tunnel_init);
|
|
module_exit(xfrm6_tunnel_exit);
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
|