xref: /openbmc/linux/net/ipv6/xfrm6_input.c (revision bbecb07f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * xfrm6_input.c: based on net/ipv4/xfrm4_input.c
4  *
5  * Authors:
6  *	Mitsuru KANDA @USAGI
7  *	Kazunori MIYAZAWA @USAGI
8  *	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
9  *	YOSHIFUJI Hideaki @USAGI
10  *		IPv6 support
11  */
12 
13 #include <linux/module.h>
14 #include <linux/string.h>
15 #include <linux/netfilter.h>
16 #include <linux/netfilter_ipv6.h>
17 #include <net/ipv6.h>
18 #include <net/xfrm.h>
19 
20 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
21 {
22 	return xfrm6_extract_header(skb);
23 }
24 
25 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
26 		  struct ip6_tnl *t)
27 {
28 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
29 	XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
30 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
31 	return xfrm_input(skb, nexthdr, spi, 0);
32 }
33 EXPORT_SYMBOL(xfrm6_rcv_spi);
34 
35 int xfrm6_transport_finish(struct sk_buff *skb, int async)
36 {
37 	struct xfrm_offload *xo = xfrm_offload(skb);
38 	int nhlen = skb->data - skb_network_header(skb);
39 
40 	skb_network_header(skb)[IP6CB(skb)->nhoff] =
41 		XFRM_MODE_SKB_CB(skb)->protocol;
42 
43 #ifndef CONFIG_NETFILTER
44 	if (!async)
45 		return 1;
46 #endif
47 
48 	__skb_push(skb, nhlen);
49 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
50 	skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
51 
52 	if (xo && (xo->flags & XFRM_GRO)) {
53 		skb_mac_header_rebuild(skb);
54 		return -1;
55 	}
56 
57 	NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
58 		dev_net(skb->dev), NULL, skb, skb->dev, NULL,
59 		ip6_rcv_finish);
60 	return -1;
61 }
62 
63 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
64 {
65 	return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
66 			     0, t);
67 }
68 EXPORT_SYMBOL(xfrm6_rcv_tnl);
69 
70 int xfrm6_rcv(struct sk_buff *skb)
71 {
72 	return xfrm6_rcv_tnl(skb, NULL);
73 }
74 EXPORT_SYMBOL(xfrm6_rcv);
75 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
76 		     xfrm_address_t *saddr, u8 proto)
77 {
78 	struct net *net = dev_net(skb->dev);
79 	struct xfrm_state *x = NULL;
80 	int i = 0;
81 
82 	if (secpath_set(skb)) {
83 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
84 		goto drop;
85 	}
86 
87 	if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
88 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
89 		goto drop;
90 	}
91 
92 	for (i = 0; i < 3; i++) {
93 		xfrm_address_t *dst, *src;
94 
95 		switch (i) {
96 		case 0:
97 			dst = daddr;
98 			src = saddr;
99 			break;
100 		case 1:
101 			/* lookup state with wild-card source address */
102 			dst = daddr;
103 			src = (xfrm_address_t *)&in6addr_any;
104 			break;
105 		default:
106 			/* lookup state with wild-card addresses */
107 			dst = (xfrm_address_t *)&in6addr_any;
108 			src = (xfrm_address_t *)&in6addr_any;
109 			break;
110 		}
111 
112 		x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
113 		if (!x)
114 			continue;
115 
116 		spin_lock(&x->lock);
117 
118 		if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
119 		    likely(x->km.state == XFRM_STATE_VALID) &&
120 		    !xfrm_state_check_expire(x)) {
121 			spin_unlock(&x->lock);
122 			if (x->type->input(x, skb) > 0) {
123 				/* found a valid state */
124 				break;
125 			}
126 		} else
127 			spin_unlock(&x->lock);
128 
129 		xfrm_state_put(x);
130 		x = NULL;
131 	}
132 
133 	if (!x) {
134 		XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
135 		xfrm_audit_state_notfound_simple(skb, AF_INET6);
136 		goto drop;
137 	}
138 
139 	skb->sp->xvec[skb->sp->len++] = x;
140 
141 	spin_lock(&x->lock);
142 
143 	x->curlft.bytes += skb->len;
144 	x->curlft.packets++;
145 
146 	spin_unlock(&x->lock);
147 
148 	return 1;
149 
150 drop:
151 	return -1;
152 }
153 EXPORT_SYMBOL(xfrm6_input_addr);
154