1/*
2 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
3 *
4 * Authors:
5 *	Mitsuru KANDA @USAGI
6 *	Kazunori MIYAZAWA @USAGI
7 *	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8 *	YOSHIFUJI Hideaki @USAGI
9 *		IPv6 support
10 */
11
12#include <linux/module.h>
13#include <linux/string.h>
14#include <linux/netfilter.h>
15#include <linux/netfilter_ipv6.h>
16#include <net/ipv6.h>
17#include <net/xfrm.h>
18
19int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
20{
21	return xfrm6_extract_header(skb);
22}
23
24int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
25{
26	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
27	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
28	return xfrm_input(skb, nexthdr, spi, 0);
29}
30EXPORT_SYMBOL(xfrm6_rcv_spi);
31
32int xfrm6_transport_finish(struct sk_buff *skb, int async)
33{
34	skb_network_header(skb)[IP6CB(skb)->nhoff] =
35		XFRM_MODE_SKB_CB(skb)->protocol;
36
37#ifndef CONFIG_NETFILTER
38	if (!async)
39		return 1;
40#endif
41
42	ipv6_hdr(skb)->payload_len = htons(skb->len);
43	__skb_push(skb, skb->data - skb_network_header(skb));
44
45	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, NULL, skb,
46		skb->dev, NULL,
47		ip6_rcv_finish);
48	return -1;
49}
50
51int xfrm6_rcv(struct sk_buff *skb)
52{
53	return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
54			     0);
55}
56EXPORT_SYMBOL(xfrm6_rcv);
57
58int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
59		     xfrm_address_t *saddr, u8 proto)
60{
61	struct net *net = dev_net(skb->dev);
62	struct xfrm_state *x = NULL;
63	int i = 0;
64
65	/* Allocate new secpath or COW existing one. */
66	if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
67		struct sec_path *sp;
68
69		sp = secpath_dup(skb->sp);
70		if (!sp) {
71			XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
72			goto drop;
73		}
74		if (skb->sp)
75			secpath_put(skb->sp);
76		skb->sp = sp;
77	}
78
79	if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
80		XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
81		goto drop;
82	}
83
84	for (i = 0; i < 3; i++) {
85		xfrm_address_t *dst, *src;
86
87		switch (i) {
88		case 0:
89			dst = daddr;
90			src = saddr;
91			break;
92		case 1:
93			/* lookup state with wild-card source address */
94			dst = daddr;
95			src = (xfrm_address_t *)&in6addr_any;
96			break;
97		default:
98			/* lookup state with wild-card addresses */
99			dst = (xfrm_address_t *)&in6addr_any;
100			src = (xfrm_address_t *)&in6addr_any;
101			break;
102		}
103
104		x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
105		if (!x)
106			continue;
107
108		spin_lock(&x->lock);
109
110		if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
111		    likely(x->km.state == XFRM_STATE_VALID) &&
112		    !xfrm_state_check_expire(x)) {
113			spin_unlock(&x->lock);
114			if (x->type->input(x, skb) > 0) {
115				/* found a valid state */
116				break;
117			}
118		} else
119			spin_unlock(&x->lock);
120
121		xfrm_state_put(x);
122		x = NULL;
123	}
124
125	if (!x) {
126		XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
127		xfrm_audit_state_notfound_simple(skb, AF_INET6);
128		goto drop;
129	}
130
131	skb->sp->xvec[skb->sp->len++] = x;
132
133	spin_lock(&x->lock);
134
135	x->curlft.bytes += skb->len;
136	x->curlft.packets++;
137
138	spin_unlock(&x->lock);
139
140	return 1;
141
142drop:
143	return -1;
144}
145EXPORT_SYMBOL(xfrm6_input_addr);
146