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 static int xfrm6_transport_finish2(struct net *net, struct sock *sk,
36 struct sk_buff *skb)
37 {
38 if (xfrm_trans_queue(skb, ip6_rcv_finish))
39 __kfree_skb(skb);
40 return -1;
41 }
42
43 int xfrm6_transport_finish(struct sk_buff *skb, int async)
44 {
45 struct xfrm_offload *xo = xfrm_offload(skb);
46 int nhlen = skb->data - skb_network_header(skb);
47
48 skb_network_header(skb)[IP6CB(skb)->nhoff] =
49 XFRM_MODE_SKB_CB(skb)->protocol;
50
51 #ifndef CONFIG_NETFILTER
52 if (!async)
53 return 1;
54 #endif
55
56 __skb_push(skb, nhlen);
57 ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
58 skb_postpush_rcsum(skb, skb_network_header(skb), nhlen);
59
60 if (xo && (xo->flags & XFRM_GRO)) {
61 skb_mac_header_rebuild(skb);
62 return -1;
63 }
64
65 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
66 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
67 xfrm6_transport_finish2);
68 return -1;
69 }
70
71 int xfrm6_rcv_tnl(struct sk_buff *skb, struct ip6_tnl *t)
72 {
73 return xfrm6_rcv_spi(skb, skb_network_header(skb)[IP6CB(skb)->nhoff],
74 0, t);
75 }
76 EXPORT_SYMBOL(xfrm6_rcv_tnl);
77
78 int xfrm6_rcv(struct sk_buff *skb)
79 {
80 return xfrm6_rcv_tnl(skb, NULL);
81 }
82 EXPORT_SYMBOL(xfrm6_rcv);
83 int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr,
84 xfrm_address_t *saddr, u8 proto)
85 {
86 struct net *net = dev_net(skb->dev);
87 struct xfrm_state *x = NULL;
88 int i = 0;
89
90 if (secpath_set(skb)) {
91 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
92 goto drop;
93 }
94
95 if (1 + skb->sp->len == XFRM_MAX_DEPTH) {
96 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
97 goto drop;
98 }
99
100 for (i = 0; i < 3; i++) {
101 xfrm_address_t *dst, *src;
102
103 switch (i) {
104 case 0:
105 dst = daddr;
106 src = saddr;
107 break;
108 case 1:
109 /* lookup state with wild-card source address */
110 dst = daddr;
111 src = (xfrm_address_t *)&in6addr_any;
112 break;
113 default:
114 /* lookup state with wild-card addresses */
115 dst = (xfrm_address_t *)&in6addr_any;
116 src = (xfrm_address_t *)&in6addr_any;
117 break;
118 }
119
120 x = xfrm_state_lookup_byaddr(net, skb->mark, dst, src, proto, AF_INET6);
121 if (!x)
122 continue;
123
124 spin_lock(&x->lock);
125
126 if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) &&
127 likely(x->km.state == XFRM_STATE_VALID) &&
128 !xfrm_state_check_expire(x)) {
129 spin_unlock(&x->lock);
130 if (x->type->input(x, skb) > 0) {
131 /* found a valid state */
132 break;
133 }
134 } else
135 spin_unlock(&x->lock);
136
137 xfrm_state_put(x);
138 x = NULL;
139 }
140
141 if (!x) {
142 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
143 xfrm_audit_state_notfound_simple(skb, AF_INET6);
144 goto drop;
145 }
146
147 skb->sp->xvec[skb->sp->len++] = x;
148
149 spin_lock(&x->lock);
150
151 x->curlft.bytes += skb->len;
152 x->curlft.packets++;
153
154 spin_unlock(&x->lock);
155
156 return 1;
157
158 drop:
159 return -1;
160 }
161 EXPORT_SYMBOL(xfrm6_input_addr);
162
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