xref: /linux/net/ipv4/xfrm4_state.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * xfrm4_state.c
3  *
4  * Changes:
5  * 	YOSHIFUJI Hideaki @USAGI
6  * 		Split up af-specific portion
7  *
8  */
9 
10 #include <net/ip.h>
11 #include <net/xfrm.h>
12 #include <linux/pfkeyv2.h>
13 #include <linux/ipsec.h>
14 #include <linux/netfilter_ipv4.h>
15 #include <linux/export.h>
16 
17 static int xfrm4_init_flags(struct xfrm_state *x)
18 {
19 	if (xs_net(x)->ipv4.sysctl_ip_no_pmtu_disc)
20 		x->props.flags |= XFRM_STATE_NOPMTUDISC;
21 	return 0;
22 }
23 
24 static void
25 __xfrm4_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
26 {
27 	const struct flowi4 *fl4 = &fl->u.ip4;
28 
29 	sel->daddr.a4 = fl4->daddr;
30 	sel->saddr.a4 = fl4->saddr;
31 	sel->dport = xfrm_flowi_dport(fl, &fl4->uli);
32 	sel->dport_mask = htons(0xffff);
33 	sel->sport = xfrm_flowi_sport(fl, &fl4->uli);
34 	sel->sport_mask = htons(0xffff);
35 	sel->family = AF_INET;
36 	sel->prefixlen_d = 32;
37 	sel->prefixlen_s = 32;
38 	sel->proto = fl4->flowi4_proto;
39 	sel->ifindex = fl4->flowi4_oif;
40 }
41 
42 static void
43 xfrm4_init_temprop(struct xfrm_state *x, const struct xfrm_tmpl *tmpl,
44 		   const xfrm_address_t *daddr, const xfrm_address_t *saddr)
45 {
46 	x->id = tmpl->id;
47 	if (x->id.daddr.a4 == 0)
48 		x->id.daddr.a4 = daddr->a4;
49 	x->props.saddr = tmpl->saddr;
50 	if (x->props.saddr.a4 == 0)
51 		x->props.saddr.a4 = saddr->a4;
52 	x->props.mode = tmpl->mode;
53 	x->props.reqid = tmpl->reqid;
54 	x->props.family = AF_INET;
55 }
56 
57 int xfrm4_extract_header(struct sk_buff *skb)
58 {
59 	const struct iphdr *iph = ip_hdr(skb);
60 
61 	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
62 	XFRM_MODE_SKB_CB(skb)->id = iph->id;
63 	XFRM_MODE_SKB_CB(skb)->frag_off = iph->frag_off;
64 	XFRM_MODE_SKB_CB(skb)->tos = iph->tos;
65 	XFRM_MODE_SKB_CB(skb)->ttl = iph->ttl;
66 	XFRM_MODE_SKB_CB(skb)->optlen = iph->ihl * 4 - sizeof(*iph);
67 	memset(XFRM_MODE_SKB_CB(skb)->flow_lbl, 0,
68 	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
69 
70 	return 0;
71 }
72 
73 static struct xfrm_state_afinfo xfrm4_state_afinfo = {
74 	.family			= AF_INET,
75 	.proto			= IPPROTO_IPIP,
76 	.eth_proto		= htons(ETH_P_IP),
77 	.owner			= THIS_MODULE,
78 	.init_flags		= xfrm4_init_flags,
79 	.init_tempsel		= __xfrm4_init_tempsel,
80 	.init_temprop		= xfrm4_init_temprop,
81 	.output			= xfrm4_output,
82 	.output_finish		= xfrm4_output_finish,
83 	.extract_input		= xfrm4_extract_input,
84 	.extract_output		= xfrm4_extract_output,
85 	.transport_finish	= xfrm4_transport_finish,
86 	.local_error		= xfrm4_local_error,
87 };
88 
89 void __init xfrm4_state_init(void)
90 {
91 	xfrm_state_register_afinfo(&xfrm4_state_afinfo);
92 }
93