[linux-2.6-block.git] / net / ipv6 / xfrm6_mode_tunnel.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/gfp.h>
#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/ip6_route.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
	struct ipv6hdr *inner_iph = ipipv6_hdr(skb);

	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
		IP6_ECN_set_ce(skb, inner_iph);
}

/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.
 */
static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct ipv6hdr *top_iph;
	int dsfield;

	skb_set_network_header(skb, -x->props.header_len);
	skb->mac_header = skb->network_header +
			  offsetof(struct ipv6hdr, nexthdr);
	skb->transport_header = skb->network_header + sizeof(*top_iph);
	top_iph = ipv6_hdr(skb);

	top_iph->version = 6;

	memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	       sizeof(top_iph->flow_lbl));
	top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);

	if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
		dsfield = 0;
	else
		dsfield = XFRM_MODE_SKB_CB(skb)->tos;
	dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
	if (x->props.flags & XFRM_STATE_NOECN)
		dsfield &= ~INET_ECN_MASK;
	ipv6_change_dsfield(top_iph, 0, dsfield);
	top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
	top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
	top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
	return 0;
}

#define for_each_input_rcu(head, handler)	\
	for (handler = rcu_dereference(head);	\
	     handler != NULL;			\
	     handler = rcu_dereference(handler->next))


static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
	int err = -EINVAL;

	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
		goto out;
	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
		goto out;

	err = skb_unclone(skb, GFP_ATOMIC);
	if (err)
		goto out;

	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
		ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
			       ipipv6_hdr(skb));
	if (!(x->props.flags & XFRM_STATE_NOECN))
		ipip6_ecn_decapsulate(skb);

	skb_reset_network_header(skb);
	skb_mac_header_rebuild(skb);

	err = 0;

out:
	return err;
}

static struct xfrm_mode xfrm6_tunnel_mode = {
	.input2 = xfrm6_mode_tunnel_input,
	.input = xfrm_prepare_input,
	.output2 = xfrm6_mode_tunnel_output,
	.output = xfrm6_prepare_output,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_TUNNEL,
	.flags = XFRM_MODE_FLAG_TUNNEL,
};

static int __init xfrm6_mode_tunnel_init(void)
{
	return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
}

static void __exit xfrm6_mode_tunnel_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
	BUG_ON(err);
}

module_init(xfrm6_mode_tunnel_init);
module_exit(xfrm6_mode_tunnel_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
Commit	Line	Data
b59f45d0 HX	1	/*
	2	* xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
	3	*
	4	* Copyright (C) 2002 USAGI/WIDE Project
	5	* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
	6	*/
	7
5a0e3ad6	8	#include <linux/gfp.h>
b59f45d0 HX	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/skbuff.h>
	13	#include <linux/stringify.h>
	14	#include <net/dsfield.h>
	15	#include <net/dst.h>
	16	#include <net/inet_ecn.h>
abbf46ae	17	#include <net/ip6_route.h>
b59f45d0 HX	18	#include <net/ipv6.h>
	19	#include <net/xfrm.h>
	20
	21	static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
	22	{
39b89160	23	struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
b59f45d0	24
eae8dee9	25	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
34ae6a1a	26	IP6_ECN_set_ce(skb, inner_iph);
b59f45d0 HX	27	}
	28
	29	/* Add encapsulation header.
	30	*
ceb1eec8	31	* The top IP header will be constructed per RFC 2401.
b59f45d0	32	*/
195ad6a3	33	static int xfrm6_mode_tunnel_output(struct xfrm_state x, struct sk_buff skb)
b59f45d0	34	{
adf30907	35	struct dst_entry *dst = skb_dst(skb);
36cf9acf	36	struct ipv6hdr *top_iph;
b59f45d0 HX	37	int dsfield;
b59f45d0 HX	38
7b277b1a	39	skb_set_network_header(skb, -x->props.header_len);
37fedd3a HX	40	skb->mac_header = skb->network_header +
37fedd3a HX	41	offsetof(struct ipv6hdr, nexthdr);
36cf9acf	42	skb->transport_header = skb->network_header + sizeof(*top_iph);
0660e03f	43	top_iph = ipv6_hdr(skb);
b59f45d0 HX	44
b59f45d0 HX	45	top_iph->version = 6;
36cf9acf HX	46
	47	memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	48	sizeof(top_iph->flow_lbl));
adf30907	49	top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
36cf9acf	50
a947b0a9 ND	51	if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
	52	dsfield = 0;
	53	else
	54	dsfield = XFRM_MODE_SKB_CB(skb)->tos;
	55	dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
b59f45d0 HX	56	if (x->props.flags & XFRM_STATE_NOECN)
	57	dsfield &= ~INET_ECN_MASK;
	58	ipv6_change_dsfield(top_iph, 0, dsfield);
abbf46ae	59	top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
4e3fd7a0 AD	60	top_iph->saddr = (struct in6_addr )&x->props.saddr;
4e3fd7a0 AD	61	top_iph->daddr = (struct in6_addr )&x->id.daddr;
b59f45d0 HX	62	return 0;
	63	}
	64
212e5601 SK	65	#define for_each_input_rcu(head, handler) \
	66	for (handler = rcu_dereference(head); \
	67	handler != NULL; \
	68	handler = rcu_dereference(handler->next))
	69
	70
195ad6a3	71	static int xfrm6_mode_tunnel_input(struct xfrm_state x, struct sk_buff skb)
b59f45d0 HX	72	{
	73	int err = -EINVAL;
	74
227620e2	75	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
b59f45d0 HX	76	goto out;
	77	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	78	goto out;
	79
0d4bfa29	80	err = skb_unclone(skb, GFP_ATOMIC);
0d4bfa29	81	if (err)
b59f45d0 HX	82	goto out;
b59f45d0 HX	83
227620e2 HX	84	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
	85	ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
	86	ipipv6_hdr(skb));
	87	if (!(x->props.flags & XFRM_STATE_NOECN))
	88	ipip6_ecn_decapsulate(skb);
	89
c1d2bbe1	90	skb_reset_network_header(skb);
03606895 ED	91	skb_mac_header_rebuild(skb);
03606895 ED	92
b59f45d0 HX	93	err = 0;
	94
	95	out:
	96	return err;
	97	}
	98
	99	static struct xfrm_mode xfrm6_tunnel_mode = {
195ad6a3	100	.input2 = xfrm6_mode_tunnel_input,
227620e2	101	.input = xfrm_prepare_input,
195ad6a3	102	.output2 = xfrm6_mode_tunnel_output,
36cf9acf	103	.output = xfrm6_prepare_output,
b59f45d0 HX	104	.owner = THIS_MODULE,
b59f45d0 HX	105	.encap = XFRM_MODE_TUNNEL,
1bfcb10f	106	.flags = XFRM_MODE_FLAG_TUNNEL,
b59f45d0 HX	107	};
b59f45d0 HX	108
195ad6a3	109	static int __init xfrm6_mode_tunnel_init(void)
b59f45d0 HX	110	{
	111	return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
	112	}
	113
195ad6a3	114	static void __exit xfrm6_mode_tunnel_exit(void)
b59f45d0 HX	115	{
	116	int err;
	117
	118	err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
	119	BUG_ON(err);
	120	}
	121
195ad6a3 HX	122	module_init(xfrm6_mode_tunnel_init);
195ad6a3 HX	123	module_exit(xfrm6_mode_tunnel_exit);
b59f45d0 HX	124	MODULE_LICENSE("GPL");
b59f45d0 HX	125	MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);