xref: /openbmc/linux/net/ipv4/xfrm4_state.c (revision 82e6fdd6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * xfrm4_state.c
4  *
5  * Changes:
6  * 	YOSHIFUJI Hideaki @USAGI
7  * 		Split up af-specific portion
8  *
9  */
10 
11 #include <net/ip.h>
12 #include <net/xfrm.h>
13 #include <linux/pfkeyv2.h>
14 #include <linux/ipsec.h>
15 #include <linux/netfilter_ipv4.h>
16 #include <linux/export.h>
17 
18 static int xfrm4_init_flags(struct xfrm_state *x)
19 {
20 	if (xs_net(x)->ipv4.sysctl_ip_no_pmtu_disc)
21 		x->props.flags |= XFRM_STATE_NOPMTUDISC;
22 	return 0;
23 }
24 
25 static void
26 __xfrm4_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
27 {
28 	const struct flowi4 *fl4 = &fl->u.ip4;
29 
30 	sel->daddr.a4 = fl4->daddr;
31 	sel->saddr.a4 = fl4->saddr;
32 	sel->dport = xfrm_flowi_dport(fl, &fl4->uli);
33 	sel->dport_mask = htons(0xffff);
34 	sel->sport = xfrm_flowi_sport(fl, &fl4->uli);
35 	sel->sport_mask = htons(0xffff);
36 	sel->family = AF_INET;
37 	sel->prefixlen_d = 32;
38 	sel->prefixlen_s = 32;
39 	sel->proto = fl4->flowi4_proto;
40 	sel->ifindex = fl4->flowi4_oif;
41 }
42 
43 static void
44 xfrm4_init_temprop(struct xfrm_state *x, const struct xfrm_tmpl *tmpl,
45 		   const xfrm_address_t *daddr, const xfrm_address_t *saddr)
46 {
47 	x->id = tmpl->id;
48 	if (x->id.daddr.a4 == 0)
49 		x->id.daddr.a4 = daddr->a4;
50 	x->props.saddr = tmpl->saddr;
51 	if (x->props.saddr.a4 == 0)
52 		x->props.saddr.a4 = saddr->a4;
53 	x->props.mode = tmpl->mode;
54 	x->props.reqid = tmpl->reqid;
55 	x->props.family = AF_INET;
56 }
57 
58 int xfrm4_extract_header(struct sk_buff *skb)
59 {
60 	const struct iphdr *iph = ip_hdr(skb);
61 
62 	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
63 	XFRM_MODE_SKB_CB(skb)->id = iph->id;
64 	XFRM_MODE_SKB_CB(skb)->frag_off = iph->frag_off;
65 	XFRM_MODE_SKB_CB(skb)->tos = iph->tos;
66 	XFRM_MODE_SKB_CB(skb)->ttl = iph->ttl;
67 	XFRM_MODE_SKB_CB(skb)->optlen = iph->ihl * 4 - sizeof(*iph);
68 	memset(XFRM_MODE_SKB_CB(skb)->flow_lbl, 0,
69 	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
70 
71 	return 0;
72 }
73 
74 static struct xfrm_state_afinfo xfrm4_state_afinfo = {
75 	.family			= AF_INET,
76 	.proto			= IPPROTO_IPIP,
77 	.eth_proto		= htons(ETH_P_IP),
78 	.owner			= THIS_MODULE,
79 	.init_flags		= xfrm4_init_flags,
80 	.init_tempsel		= __xfrm4_init_tempsel,
81 	.init_temprop		= xfrm4_init_temprop,
82 	.output			= xfrm4_output,
83 	.output_finish		= xfrm4_output_finish,
84 	.extract_input		= xfrm4_extract_input,
85 	.extract_output		= xfrm4_extract_output,
86 	.transport_finish	= xfrm4_transport_finish,
87 	.local_error		= xfrm4_local_error,
88 };
89 
90 void __init xfrm4_state_init(void)
91 {
92 	xfrm_state_register_afinfo(&xfrm4_state_afinfo);
93 }
94