[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_inner_network_header(skb, skb_network_offset(skb));
	skb_set_inner_transport_header(skb, skb_transport_offset(skb));

	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 sk_buff *xfrm6_mode_tunnel_gso_segment(struct xfrm_state *x,
						     struct sk_buff *skb,
						     netdev_features_t features)
{
	__skb_push(skb, skb->mac_len);
	return skb_mac_gso_segment(skb, features);

}

static void xfrm6_mode_tunnel_xmit(struct xfrm_state *x, struct sk_buff *skb)
{
	struct xfrm_offload *xo = xfrm_offload(skb);

	if (xo->flags & XFRM_GSO_SEGMENT) {
		skb->network_header = skb->network_header - x->props.header_len;
		skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
	}

	skb_reset_mac_len(skb);
	pskb_pull(skb, skb->mac_len + x->props.header_len);
}

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,
	.gso_segment = xfrm6_mode_tunnel_gso_segment,
	.xmit = xfrm6_mode_tunnel_xmit,
	.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
f1bd7d65 IT	39	skb_set_inner_network_header(skb, skb_network_offset(skb));
	40	skb_set_inner_transport_header(skb, skb_transport_offset(skb));
	41
7b277b1a	42	skb_set_network_header(skb, -x->props.header_len);
37fedd3a HX	43	skb->mac_header = skb->network_header +
37fedd3a HX	44	offsetof(struct ipv6hdr, nexthdr);
36cf9acf	45	skb->transport_header = skb->network_header + sizeof(*top_iph);
0660e03f	46	top_iph = ipv6_hdr(skb);
b59f45d0 HX	47
b59f45d0 HX	48	top_iph->version = 6;
36cf9acf HX	49
	50	memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
	51	sizeof(top_iph->flow_lbl));
adf30907	52	top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
36cf9acf	53
a947b0a9 ND	54	if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
	55	dsfield = 0;
	56	else
	57	dsfield = XFRM_MODE_SKB_CB(skb)->tos;
	58	dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
b59f45d0 HX	59	if (x->props.flags & XFRM_STATE_NOECN)
	60	dsfield &= ~INET_ECN_MASK;
	61	ipv6_change_dsfield(top_iph, 0, dsfield);
abbf46ae	62	top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
4e3fd7a0 AD	63	top_iph->saddr = (struct in6_addr )&x->props.saddr;
4e3fd7a0 AD	64	top_iph->daddr = (struct in6_addr )&x->id.daddr;
b59f45d0 HX	65	return 0;
	66	}
	67
212e5601 SK	68	#define for_each_input_rcu(head, handler) \
	69	for (handler = rcu_dereference(head); \
	70	handler != NULL; \
	71	handler = rcu_dereference(handler->next))
	72
	73
195ad6a3	74	static int xfrm6_mode_tunnel_input(struct xfrm_state x, struct sk_buff skb)
b59f45d0 HX	75	{
	76	int err = -EINVAL;
	77
227620e2	78	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
b59f45d0 HX	79	goto out;
	80	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
	81	goto out;
	82
0d4bfa29	83	err = skb_unclone(skb, GFP_ATOMIC);
0d4bfa29	84	if (err)
b59f45d0 HX	85	goto out;
b59f45d0 HX	86
227620e2 HX	87	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
	88	ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
	89	ipipv6_hdr(skb));
	90	if (!(x->props.flags & XFRM_STATE_NOECN))
	91	ipip6_ecn_decapsulate(skb);
	92
c1d2bbe1	93	skb_reset_network_header(skb);
03606895 ED	94	skb_mac_header_rebuild(skb);
03606895 ED	95
b59f45d0 HX	96	err = 0;
	97
	98	out:
	99	return err;
	100	}
	101
c35fe410 SK	102	static struct sk_buff xfrm6_mode_tunnel_gso_segment(struct xfrm_state x,
	103	struct sk_buff *skb,
	104	netdev_features_t features)
	105	{
	106	__skb_push(skb, skb->mac_len);
	107	return skb_mac_gso_segment(skb, features);
	108
	109	}
	110
	111	static void xfrm6_mode_tunnel_xmit(struct xfrm_state x, struct sk_buff skb)
	112	{
	113	struct xfrm_offload *xo = xfrm_offload(skb);
	114
	115	if (xo->flags & XFRM_GSO_SEGMENT) {
	116	skb->network_header = skb->network_header - x->props.header_len;
	117	skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
	118	}
	119
	120	skb_reset_mac_len(skb);
	121	pskb_pull(skb, skb->mac_len + x->props.header_len);
	122	}
	123
b59f45d0	124	static struct xfrm_mode xfrm6_tunnel_mode = {
195ad6a3	125	.input2 = xfrm6_mode_tunnel_input,
227620e2	126	.input = xfrm_prepare_input,
195ad6a3	127	.output2 = xfrm6_mode_tunnel_output,
36cf9acf	128	.output = xfrm6_prepare_output,
c35fe410 SK	129	.gso_segment = xfrm6_mode_tunnel_gso_segment,
c35fe410 SK	130	.xmit = xfrm6_mode_tunnel_xmit,
b59f45d0 HX	131	.owner = THIS_MODULE,
b59f45d0 HX	132	.encap = XFRM_MODE_TUNNEL,
1bfcb10f	133	.flags = XFRM_MODE_FLAG_TUNNEL,
b59f45d0 HX	134	};
b59f45d0 HX	135
195ad6a3	136	static int __init xfrm6_mode_tunnel_init(void)
b59f45d0 HX	137	{
	138	return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
	139	}
	140
195ad6a3	141	static void __exit xfrm6_mode_tunnel_exit(void)
b59f45d0 HX	142	{
	143	int err;
	144
	145	err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
	146	BUG_ON(err);
	147	}
	148
195ad6a3 HX	149	module_init(xfrm6_mode_tunnel_init);
195ad6a3 HX	150	module_exit(xfrm6_mode_tunnel_exit);
b59f45d0 HX	151	MODULE_LICENSE("GPL");
b59f45d0 HX	152	MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);