aboutsummaryrefslogtreecommitdiffstats
path: root/net/ipv6/xfrm6_input.c
blob: 0405d74ff910098f54d23a042bf3995a4a99e593 (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
/*
 * 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_rcv_spi(struct sk_buff *skb, u32 spi)
{
	int err;
	u32 seq;
	struct xfrm_state *xfrm_vec[XFRM_MAX_DEPTH];
	struct xfrm_state *x;
	int xfrm_nr = 0;
	int decaps = 0;
	int nexthdr;
	unsigned int nhoff;

	nhoff = IP6CB(skb)->nhoff;
	nexthdr = skb->nh.raw[nhoff];

	seq = 0;
	if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
		goto drop;
	
	do {
		struct ipv6hdr *iph = skb->nh.ipv6h;

		if (xfrm_nr == XFRM_MAX_DEPTH)
			goto drop;

		x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, nexthdr, AF_INET6);
		if (x == NULL)
			goto drop;
		spin_lock(&x->lock);
		if (unlikely(x->km.state != XFRM_STATE_VALID))
			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;

		nexthdr = x->type->input(x, skb);
		if (nexthdr <= 0)
			goto drop_unlock;

		skb->nh.raw[nhoff] = nexthdr;

		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) { /* XXX */
			decaps = 1;
			break;
		}

		if ((err = xfrm_parse_spi(skb, nexthdr, &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;
	skb->ip_summed = CHECKSUM_NONE;

	nf_reset(skb);

	if (decaps) {
		if (!(skb->dev->flags&IFF_LOOPBACK)) {
			dst_release(skb->dst);
			skb->dst = NULL;
		}
		netif_rx(skb);
		return -1;
	} else {
#ifdef CONFIG_NETFILTER
		skb->nh.ipv6h->payload_len = htons(skb->len);
		__skb_push(skb, skb->data - skb->nh.raw);

		NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL,
		        ip6_rcv_finish);
		return -1;
#else
		return 1;
#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 -1;
}

EXPORT_SYMBOL(xfrm6_rcv_spi);

int xfrm6_rcv(struct sk_buff **pskb)
{
	return xfrm6_rcv_spi(*pskb, 0);
}