xref: /openbmc/linux/net/ipv6/xfrm6_input.c (revision a1e58bbd)
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 {
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 }
30 EXPORT_SYMBOL(xfrm6_rcv_spi);
31 
32 int 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(PF_INET6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
46 		ip6_rcv_finish);
47 	return -1;
48 }
49 
50 int xfrm6_rcv(struct sk_buff *skb)
51 {
52 	return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
53 			     0);
54 }
55 
56 EXPORT_SYMBOL(xfrm6_rcv);
57 
58 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
59 		     xfrm_address_t *saddr, u8 proto)
60 {
61 	struct xfrm_state *x = NULL;
62 	int wildcard = 0;
63 	xfrm_address_t *xany;
64 	int nh = 0;
65 	int i = 0;
66 
67 	/* Allocate new secpath or COW existing one. */
68 	if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
69 		struct sec_path *sp;
70 
71 		sp = secpath_dup(skb->sp);
72 		if (!sp) {
73 			XFRM_INC_STATS(LINUX_MIB_XFRMINERROR);
74 			goto drop;
75 		}
76 		if (skb->sp)
77 			secpath_put(skb->sp);
78 		skb->sp = sp;
79 	}
80 
81 	if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
82 		XFRM_INC_STATS(LINUX_MIB_XFRMINBUFFERERROR);
83 		goto drop;
84 	}
85 
86 	xany = (xfrm_address_t *)&in6addr_any;
87 
88 	for (i = 0; i < 3; i++) {
89 		xfrm_address_t *dst, *src;
90 		switch (i) {
91 		case 0:
92 			dst = daddr;
93 			src = saddr;
94 			break;
95 		case 1:
96 			/* lookup state with wild-card source address */
97 			wildcard = 1;
98 			dst = daddr;
99 			src = xany;
100 			break;
101 		case 2:
102 		default:
103 			/* lookup state with wild-card addresses */
104 			wildcard = 1; /* XXX */
105 			dst = xany;
106 			src = xany;
107 			break;
108 		}
109 
110 		x = xfrm_state_lookup_byaddr(dst, src, proto, AF_INET6);
111 		if (!x)
112 			continue;
113 
114 		spin_lock(&x->lock);
115 
116 		if (wildcard) {
117 			if ((x->props.flags & XFRM_STATE_WILDRECV) == 0) {
118 				spin_unlock(&x->lock);
119 				xfrm_state_put(x);
120 				x = NULL;
121 				continue;
122 			}
123 		}
124 
125 		if (unlikely(x->km.state != XFRM_STATE_VALID)) {
126 			spin_unlock(&x->lock);
127 			xfrm_state_put(x);
128 			x = NULL;
129 			continue;
130 		}
131 		if (xfrm_state_check_expire(x)) {
132 			spin_unlock(&x->lock);
133 			xfrm_state_put(x);
134 			x = NULL;
135 			continue;
136 		}
137 
138 		spin_unlock(&x->lock);
139 
140 		nh = x->type->input(x, skb);
141 		if (nh <= 0) {
142 			xfrm_state_put(x);
143 			x = NULL;
144 			continue;
145 		}
146 
147 		/* Found a state */
148 		break;
149 	}
150 
151 	if (!x) {
152 		XFRM_INC_STATS(LINUX_MIB_XFRMINNOSTATES);
153 		xfrm_audit_state_notfound_simple(skb, AF_INET6);
154 		goto drop;
155 	}
156 
157 	skb->sp->xvec[skb->sp->len++] = x;
158 
159 	spin_lock(&x->lock);
160 
161 	x->curlft.bytes += skb->len;
162 	x->curlft.packets++;
163 
164 	spin_unlock(&x->lock);
165 
166 	return 1;
167 
168 drop:
169 	return -1;
170 }
171 
172 EXPORT_SYMBOL(xfrm6_input_addr);
173