aboutsummaryrefslogtreecommitdiffstats
path: root/net/ipv6/xfrm6_input.c
blob: f835ab458f5b73220431af58f92b5d7575eb9b50 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*
 * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
 *
 * Authors:
 *	Mitsuru KANDA @USAGI
 * 	Kazunori MIYAZAWA @USAGI
 * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 *	YOSHIFUJI Hideaki @USAGI
 *		IPv6 support
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
{
	return xfrm6_extract_header(skb);
}

int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
{
	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
	return xfrm_input(skb, nexthdr, spi, 0);
}
EXPORT_SYMBOL(xfrm6_rcv_spi);

int xfrm6_transport_finish(struct sk_buff *skb, int async)
{
	skb_network_header(skb)[IP6CB(skb)->nhoff] =
		XFRM_MODE_SKB_CB(skb)->protocol;

#ifdef CONFIG_NETFILTER
	ipv6_hdr(skb)->payload_len = htons(skb->len);
	__skb_push(skb, skb->data - skb_network_header(skb));

	NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
		ip6_rcv_finish);
	return -1;
#else
	if (async)
		return ip6_rcv_finish(skb);

	return 1;
#endif
}

int xfrm6_rcv(struct sk_buff *skb)
{
	return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
			     0);
}

EXPORT_SYMBOL(xfrm6_rcv);

int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
		     xfrm_address_t *saddr, u8 proto)
{
	struct xfrm_state *x = NULL;
	int wildcard = 0;
	xfrm_address_t *xany;
	int nh = 0;
	int i = 0;

	/* 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 (1 + skb->sp->len == XFRM_MAX_DEPTH) {
		goto drop;
	}

	xany = (xfrm_address_t *)&in6addr_any;

	for (i = 0; i < 3; i++) {
		xfrm_address_t *dst, *src;
		switch (i) {
		case 0:
			dst = daddr;
			src = saddr;
			break;
		case 1:
			/* lookup state with wild-card source address */
			wildcard = 1;
			dst = daddr;
			src = xany;
			break;
		case 2:
		default:
			/* lookup state with wild-card addresses */
			wildcard = 1; /* XXX */
			dst = xany;
			src = xany;
			break;
		}

		x = xfrm_state_lookup_byaddr(dst, src, proto, AF_INET6);
		if (!x)
			continue;

		spin_lock(&x->lock);

		if (wildcard) {
			if ((x->props.flags & XFRM_STATE_WILDRECV) == 0) {
				spin_unlock(&x->lock);
				xfrm_state_put(x);
				x = NULL;
				continue;
			}
		}

		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
			spin_unlock(&x->lock);
			xfrm_state_put(x);
			x = NULL;
			continue;
		}
		if (xfrm_state_check_expire(x)) {
			spin_unlock(&x->lock);
			xfrm_state_put(x);
			x = NULL;
			continue;
		}

		spin_unlock(&x->lock);

		nh = x->type->input(x, skb);
		if (nh <= 0) {
			xfrm_state_put(x);
			x = NULL;
			continue;
		}

		/* Found a state */
		break;
	}

	if (!x) {
		goto drop;
	}

	skb->sp->xvec[skb->sp->len++] = x;

	spin_lock(&x->lock);

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

	spin_unlock(&x->lock);

	return 1;

drop:
	return -1;
}

EXPORT_SYMBOL(xfrm6_input_addr);