[net-next-2.6.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/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 sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct xfrm_state *x = dst->xfrm;
	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);
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
	8	#include <linux/init.h>
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/skbuff.h>
	12	#include <linux/stringify.h>
	13	#include <net/dsfield.h>
	14	#include <net/dst.h>
	15	#include <net/inet_ecn.h>
	16	#include <net/ipv6.h>
	17	#include <net/xfrm.h>
	18
	19	static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
	20	{
	21	struct ipv6hdr *outer_iph = skb->nh.ipv6h;
	22	struct ipv6hdr *inner_iph = skb->h.ipv6h;
	23
	24	if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
	25	IP6_ECN_set_ce(inner_iph);
	26	}
	27
	28	/* Add encapsulation header.
	29	*
	30	* The top IP header will be constructed per RFC 2401. The following fields
	31	* in it shall be filled in by x->type->output:
	32	* payload_len
	33	*
	34	* On exit, skb->h will be set to the start of the encapsulation header to be
	35	* filled in by x->type->output and skb->nh will be set to the nextheader field
	36	* of the extension header directly preceding the encapsulation header, or in
	37	* its absence, that of the top IP header. The value of skb->data will always
	38	* point to the top IP header.
	39	*/
	40	static int xfrm6_tunnel_output(struct sk_buff *skb)
	41	{
	42	struct dst_entry *dst = skb->dst;
	43	struct xfrm_state *x = dst->xfrm;
	44	struct ipv6hdr iph, top_iph;
	45	int dsfield;
	46
	47	skb_push(skb, x->props.header_len);
	48	iph = skb->nh.ipv6h;
	49
	50	skb->nh.raw = skb->data;
	51	top_iph = skb->nh.ipv6h;
	52	skb->nh.raw = &top_iph->nexthdr;
	53	skb->h.ipv6h = top_iph + 1;
	54
	55	top_iph->version = 6;
	56	top_iph->priority = iph->priority;
	57	top_iph->flow_lbl[0] = iph->flow_lbl[0];
	58	top_iph->flow_lbl[1] = iph->flow_lbl[1];
	59	top_iph->flow_lbl[2] = iph->flow_lbl[2];
	60	dsfield = ipv6_get_dsfield(top_iph);
	61	dsfield = INET_ECN_encapsulate(dsfield, dsfield);
	62	if (x->props.flags & XFRM_STATE_NOECN)
	63	dsfield &= ~INET_ECN_MASK;
	64	ipv6_change_dsfield(top_iph, 0, dsfield);
65	top_iph->nexthdr = IPPROTO_IPV6;
66	top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
67	ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
68	ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
69	return 0;
70	}
71
72	static int xfrm6_tunnel_input(struct xfrm_state x, struct sk_buff skb)
73	{
74	int err = -EINVAL;
75
76	if (skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPV6)
77	goto out;
78	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
79	goto out;
80
81	if (skb_cloned(skb) &&
82	(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
83	goto out;
84
85	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
86	ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
87	if (!(x->props.flags & XFRM_STATE_NOECN))
88	ipip6_ecn_decapsulate(skb);
89	skb->mac.raw = memmove(skb->data - skb->mac_len,
90	skb->mac.raw, skb->mac_len);
91	skb->nh.raw = skb->data;
92	err = 0;
93
94	out:
95	return err;
96	}
97
98	static struct xfrm_mode xfrm6_tunnel_mode = {
99	.input = xfrm6_tunnel_input,
100	.output = xfrm6_tunnel_output,
101	.owner = THIS_MODULE,
102	.encap = XFRM_MODE_TUNNEL,
103	};
104
105	static int __init xfrm6_tunnel_init(void)
106	{
107	return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
108	}
109
110	static void __exit xfrm6_tunnel_exit(void)
111	{
112	int err;
113
114	err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
115	BUG_ON(err);
116	}
117
118	module_init(xfrm6_tunnel_init);
119	module_exit(xfrm6_tunnel_exit);
120	MODULE_LICENSE("GPL");
121	MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);