linux/net/ipv6/xfrm6_mode_tunnel.c
Jamal Hadi Salim eb878e8457 [IPSEC]: output mode to take an xfrm state as input param
Expose IPSEC modes output path to take an xfrm state as input param.
This makes it consistent with the input mode processing (which already
takes the xfrm state as a param).

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22 15:18:48 -07:00

121 lines
3.2 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 = skb->nh.ipv6h;
struct ipv6hdr *inner_iph = skb->h.ipv6h;
if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
IP6_ECN_set_ce(inner_iph);
}
/* 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 ipv6hdr *iph, *top_iph;
int dsfield;
skb_push(skb, x->props.header_len);
iph = skb->nh.ipv6h;
skb->nh.raw = skb->data;
top_iph = skb->nh.ipv6h;
skb->nh.raw = &top_iph->nexthdr;
skb->h.ipv6h = top_iph + 1;
top_iph->version = 6;
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];
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->nexthdr = IPPROTO_IPV6;
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;
if (skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPV6)
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;
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip6_ecn_decapsulate(skb);
skb->mac.raw = memmove(skb->data - skb->mac_len,
skb->mac.raw, skb->mac_len);
skb->nh.raw = skb->data;
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);