xref: /linux/net/ipv6/xfrm6_input.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
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 
19 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
20 {
21 	return xfrm6_extract_header(skb);
22 }
23 
24 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
25 		  struct ip6_tnl *t)
26 {
27 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
28 	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
29 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
30 	return xfrm_input(skb, nexthdr, spi, 0);
31 }
32 EXPORT_SYMBOL(xfrm6_rcv_spi);
33 
34 int xfrm6_transport_finish(struct sk_buff *skb, int async)
35 {
36 	struct xfrm_offload *xo = xfrm_offload(skb);
37 
38 	skb_network_header(skb)[IP6CB(skb)->nhoff] =
39 		XFRM_MODE_SKB_CB(skb)->protocol;
40 
41 #ifndef CONFIG_NETFILTER
42 	if (!async)
43 		return 1;
44 #endif
45 
46 	__skb_push(skb, skb->data - skb_network_header(skb));
47 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
48 
49 	if (xo && (xo->flags & XFRM_GRO)) {
50 		skb_mac_header_rebuild(skb);
51 		return -1;
52 	}
53 
54 	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
55 		dev_net(skb->dev), NULL, skb, skb->dev, NULL,
56 		ip6_rcv_finish);
57 	return -1;
58 }
59 
60 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
61 {
62 	return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
63 			     0, t);
64 }
65 EXPORT_SYMBOL(xfrm6_rcv_tnl);
66 
67 int xfrm6_rcv(struct sk_buff *skb)
68 {
69 	return xfrm6_rcv_tnl(skb, NULL);
70 }
71 EXPORT_SYMBOL(xfrm6_rcv);
72 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
73 		     xfrm_address_t *saddr, u8 proto)
74 {
75 	struct net *net = dev_net(skb->dev);
76 	struct xfrm_state *x = NULL;
77 	int i = 0;
78 
79 	if (secpath_set(skb)) {
80 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
81 		goto drop;
82 	}
83 
84 	if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
85 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
86 		goto drop;
87 	}
88 
89 	for (i = 0; i < 3; i++) {
90 		xfrm_address_t *dst, *src;
91 
92 		switch (i) {
93 		case 0:
94 			dst = daddr;
95 			src = saddr;
96 			break;
97 		case 1:
98 			/* lookup state with wild-card source address */
99 			dst = daddr;
100 			src = (xfrm_address_t *)&in6addr_any;
101 			break;
102 		default:
103 			/* lookup state with wild-card addresses */
104 			dst = (xfrm_address_t *)&in6addr_any;
105 			src = (xfrm_address_t *)&in6addr_any;
106 			break;
107 		}
108 
109 		x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
110 		if (!x)
111 			continue;
112 
113 		spin_lock(&x->lock);
114 
115 		if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
116 		    likely(x->km.state == XFRM_STATE_VALID) &&
117 		    !xfrm_state_check_expire(x)) {
118 			spin_unlock(&x->lock);
119 			if (x->type->input(x, skb) > 0) {
120 				/* found a valid state */
121 				break;
122 			}
123 		} else
124 			spin_unlock(&x->lock);
125 
126 		xfrm_state_put(x);
127 		x = NULL;
128 	}
129 
130 	if (!x) {
131 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
132 		xfrm_audit_state_notfound_simple(skb, AF_INET6);
133 		goto drop;
134 	}
135 
136 	skb->sp->xvec[skb->sp->len++] = x;
137 
138 	spin_lock(&x->lock);
139 
140 	x->curlft.bytes += skb->len;
141 	x->curlft.packets++;
142 
143 	spin_unlock(&x->lock);
144 
145 	return 1;
146 
147 drop:
148 	return -1;
149 }
150 EXPORT_SYMBOL(xfrm6_input_addr);
151