[mirror_ubuntu-artful-kernel.git] / net / ipv4 / xfrm4_input.c

/*
 * xfrm4_input.c
 *
 * Changes:
 *	YOSHIFUJI Hideaki @USAGI
 *		Split up af-specific portion
 *	Derek Atkins <derek@ihtfp.com>
 *		Add Encapsulation support
 * 	
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <net/ip.h>
#include <net/xfrm.h>

int xfrm4_rcv(struct sk_buff *skb)
{
	return xfrm4_rcv_encap(skb, 0);
}

EXPORT_SYMBOL(xfrm4_rcv);

static int xfrm4_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
{
	switch (nexthdr) {
	case IPPROTO_IPIP:
		*spi = skb->nh.iph->saddr;
		*seq = 0;
		return 0;
	}

	return xfrm_parse_spi(skb, nexthdr, spi, seq);
}

#ifdef CONFIG_NETFILTER
static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb)
{
	struct iphdr *iph = skb->nh.iph;

	if (skb->dst == NULL) {
		if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
		                   skb->dev))
			goto drop;
	}
	return dst_input(skb);
drop:
	kfree_skb(skb);
	return NET_RX_DROP;
}
#endif

int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
{
	int err;
	__be32 spi, seq;
	struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
	struct xfrm_state *x;
	int xfrm_nr = 0;
	int decaps = 0;

	if ((err = xfrm4_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0)
		goto drop;

	do {
		struct iphdr *iph = skb->nh.iph;

		if (xfrm_nr == XFRM_MAX_DEPTH)
			goto drop;

		x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, iph->protocol, AF_INET);
		if (x == NULL)
			goto drop;

		spin_lock(&x->lock);
		if (unlikely(x->km.state != XFRM_STATE_VALID))
			goto drop_unlock;

		if ((x->encap ? x->encap->encap_type : 0) != encap_type)
			goto drop_unlock;

		if (x->props.replay_window && xfrm_replay_check(x, seq))
			goto drop_unlock;

		if (xfrm_state_check_expire(x))
			goto drop_unlock;

		if (x->type->input(x, skb))
			goto drop_unlock;

		/* only the first xfrm gets the encap type */
		encap_type = 0;

		if (x->props.replay_window)
			xfrm_replay_advance(x, seq);

		x->curlft.bytes += skb->len;
		x->curlft.packets++;

		spin_unlock(&x->lock);

		xfrm_vec[xfrm_nr++] = x;

		if (x->mode->input(x, skb))
			goto drop;

		if (x->props.mode == XFRM_MODE_TUNNEL) {
			decaps = 1;
			break;
		}

		if ((err = xfrm_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) < 0)
			goto drop;
	} while (!err);

	/* Allocate new secpath or COW existing one. */

	if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
		struct sec_path *sp;
		sp = secpath_dup(skb->sp);
		if (!sp)
			goto drop;
		if (skb->sp)
			secpath_put(skb->sp);
		skb->sp = sp;
	}
	if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
		goto drop;

	memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec,
	       xfrm_nr * sizeof(xfrm_vec[0]));
	skb->sp->len += xfrm_nr;

	nf_reset(skb);

	if (decaps) {
		if (!(skb->dev->flags&IFF_LOOPBACK)) {
			dst_release(skb->dst);
			skb->dst = NULL;
		}
		netif_rx(skb);
		return 0;
	} else {
#ifdef CONFIG_NETFILTER
		__skb_push(skb, skb->data - skb->nh.raw);
		skb->nh.iph->tot_len = htons(skb->len);
		ip_send_check(skb->nh.iph);

		NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
		        xfrm4_rcv_encap_finish);
		return 0;
#else
		return -skb->nh.iph->protocol;
#endif
	}

drop_unlock:
	spin_unlock(&x->lock);
	xfrm_state_put(x);
drop:
	while (--xfrm_nr >= 0)
		xfrm_state_put(xfrm_vec[xfrm_nr]);

	kfree_skb(skb);
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* xfrm4_input.c
	3	*
	4	* Changes:
	5	* YOSHIFUJI Hideaki @USAGI
	6	* Split up af-specific portion
	7	* Derek Atkins <derek@ihtfp.com>
	8	* Add Encapsulation support
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/string.h>
b05e1066 PM	14	#include <linux/netfilter.h>
b05e1066 PM	15	#include <linux/netfilter_ipv4.h>
1da177e4 LT	16	#include <net/ip.h>
	17	#include <net/xfrm.h>
	18
	19	int xfrm4_rcv(struct sk_buff *skb)
	20	{
	21	return xfrm4_rcv_encap(skb, 0);
	22	}
	23
	24	EXPORT_SYMBOL(xfrm4_rcv);
	25
6067b2ba	26	static int xfrm4_parse_spi(struct sk_buff skb, u8 nexthdr, __be32 spi, __be32 *seq)
1da177e4 LT	27	{
	28	switch (nexthdr) {
	29	case IPPROTO_IPIP:
1da177e4 LT	30	*spi = skb->nh.iph->saddr;
	31	*seq = 0;
	32	return 0;
	33	}
	34
	35	return xfrm_parse_spi(skb, nexthdr, spi, seq);
	36	}
	37
b05e1066 PM	38	#ifdef CONFIG_NETFILTER
	39	static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb)
	40	{
	41	struct iphdr *iph = skb->nh.iph;
	42
	43	if (skb->dst == NULL) {
	44	if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
	45	skb->dev))
	46	goto drop;
	47	}
	48	return dst_input(skb);
	49	drop:
	50	kfree_skb(skb);
	51	return NET_RX_DROP;
	52	}
	53	#endif
	54
1da177e4 LT	55	int xfrm4_rcv_encap(struct sk_buff *skb, __u16 encap_type)
	56	{
	57	int err;
6067b2ba	58	__be32 spi, seq;
dbe5b4aa	59	struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
1da177e4 LT	60	struct xfrm_state *x;
	61	int xfrm_nr = 0;
	62	int decaps = 0;
	63
	64	if ((err = xfrm4_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) != 0)
	65	goto drop;
	66
	67	do {
	68	struct iphdr *iph = skb->nh.iph;
	69
	70	if (xfrm_nr == XFRM_MAX_DEPTH)
	71	goto drop;
	72
	73	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, iph->protocol, AF_INET);
	74	if (x == NULL)
	75	goto drop;
	76
	77	spin_lock(&x->lock);
	78	if (unlikely(x->km.state != XFRM_STATE_VALID))
	79	goto drop_unlock;
	80
8bf4b8a1	81	if ((x->encap ? x->encap->encap_type : 0) != encap_type)
e695633e HX	82	goto drop_unlock;
e695633e HX	83
1da177e4 LT	84	if (x->props.replay_window && xfrm_replay_check(x, seq))
	85	goto drop_unlock;
	86
	87	if (xfrm_state_check_expire(x))
	88	goto drop_unlock;
	89
e695633e	90	if (x->type->input(x, skb))
1da177e4 LT	91	goto drop_unlock;
	92
	93	/* only the first xfrm gets the encap type */
	94	encap_type = 0;
	95
	96	if (x->props.replay_window)
	97	xfrm_replay_advance(x, seq);
	98
	99	x->curlft.bytes += skb->len;
	100	x->curlft.packets++;
	101
	102	spin_unlock(&x->lock);
	103
dbe5b4aa	104	xfrm_vec[xfrm_nr++] = x;
1da177e4	105
b59f45d0 HX	106	if (x->mode->input(x, skb))
b59f45d0 HX	107	goto drop;
1da177e4	108
7e49e6de	109	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	110	decaps = 1;
	111	break;
	112	}
	113
	114	if ((err = xfrm_parse_spi(skb, skb->nh.iph->protocol, &spi, &seq)) < 0)
	115	goto drop;
	116	} while (!err);
	117
	118	/* Allocate new secpath or COW existing one. */
	119
	120	if (!skb->sp \|\| atomic_read(&skb->sp->refcnt) != 1) {
	121	struct sec_path *sp;
	122	sp = secpath_dup(skb->sp);
	123	if (!sp)
	124	goto drop;
	125	if (skb->sp)
	126	secpath_put(skb->sp);
	127	skb->sp = sp;
	128	}
	129	if (xfrm_nr + skb->sp->len > XFRM_MAX_DEPTH)
	130	goto drop;
	131
dbe5b4aa HX	132	memcpy(skb->sp->xvec + skb->sp->len, xfrm_vec,
dbe5b4aa HX	133	xfrm_nr * sizeof(xfrm_vec[0]));
1da177e4 LT	134	skb->sp->len += xfrm_nr;
1da177e4 LT	135
b05e1066 PM	136	nf_reset(skb);
b05e1066 PM	137
1da177e4 LT	138	if (decaps) {
	139	if (!(skb->dev->flags&IFF_LOOPBACK)) {
	140	dst_release(skb->dst);
	141	skb->dst = NULL;
	142	}
	143	netif_rx(skb);
	144	return 0;
	145	} else {
b05e1066 PM	146	#ifdef CONFIG_NETFILTER
	147	__skb_push(skb, skb->data - skb->nh.raw);
	148	skb->nh.iph->tot_len = htons(skb->len);
	149	ip_send_check(skb->nh.iph);
	150
	151	NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
	152	xfrm4_rcv_encap_finish);
	153	return 0;
	154	#else
1da177e4	155	return -skb->nh.iph->protocol;
b05e1066	156	#endif
1da177e4 LT	157	}
	158
	159	drop_unlock:
	160	spin_unlock(&x->lock);
	161	xfrm_state_put(x);
	162	drop:
	163	while (--xfrm_nr >= 0)
dbe5b4aa	164	xfrm_state_put(xfrm_vec[xfrm_nr]);
1da177e4 LT	165
	166	kfree_skb(skb);
	167	return 0;
	168	}