summaryrefslogtreecommitdiffstats
path: root/net/ipv6/xfrm6_input.c
blob: 1079e47f393383f09624988e705e55d5c9080fa7 (plain)
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
/*
 * 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 <net/dsfield.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/xfrm.h>

static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
	struct ipv6hdr *outer_iph = skb->nh.ipv6h;
	struct ipv6hdr *inner_iph = skb->h.ipv6h;

	if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
		IP6_ECN_set_ce(inner_iph);
}

int xfrm6_rcv_spi(struct sk_buff **pskb, u32 spi)
{
	struct sk_buff *skb = *pskb;
	int err;
	u32 seq;
	struct sec_decap_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, &(xfrm_vec[xfrm_nr].decap), 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++].xvec = x;

		if (x->props.mode) { /* XXX */
			if (nexthdr != IPPROTO_IPV6)
				goto drop;
			if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
				goto drop;
			if (skb_cloned(skb) &&
			    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
				goto drop;
			if (x->props.flags & XFRM_STATE_DECAP_DSCP)
				ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
			if (!(x->props.flags & XFRM_STATE_NOECN))
				ipip6_ecn_decapsulate(skb);
			skb->mac.raw = memmove(skb->data - skb->mac_len,
					       skb->mac.raw, skb->mac_len);
			skb->nh.raw = skb->data;
			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->x+skb->sp->len, xfrm_vec, xfrm_nr*sizeof(struct sec_decap_state));
	skb->sp->len += xfrm_nr;
	skb->ip_summed = CHECKSUM_NONE;

	if (decaps) {
		if (!(skb->dev->flags&IFF_LOOPBACK)) {
			dst_release(skb->dst);
			skb->dst = NULL;
		}
		netif_rx(skb);
		return -1;
	} else {
		return 1;
	}

drop_unlock:
	spin_unlock(&x->lock);
	xfrm_state_put(x);
drop:
	while (--xfrm_nr >= 0)
		xfrm_state_put(xfrm_vec[xfrm_nr].xvec);
	kfree_skb(skb);
	return -1;
}

EXPORT_SYMBOL(xfrm6_rcv_spi);

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