xref: /openbmc/linux/net/xfrm/xfrm_input.c (revision c21b37f6)
1 /*
2  * xfrm_input.c
3  *
4  * Changes:
5  * 	YOSHIFUJI Hideaki @USAGI
6  * 		Split up af-specific portion
7  *
8  */
9 
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <net/ip.h>
13 #include <net/xfrm.h>
14 
15 static struct kmem_cache *secpath_cachep __read_mostly;
16 
17 void __secpath_destroy(struct sec_path *sp)
18 {
19 	int i;
20 	for (i = 0; i < sp->len; i++)
21 		xfrm_state_put(sp->xvec[i]);
22 	kmem_cache_free(secpath_cachep, sp);
23 }
24 EXPORT_SYMBOL(__secpath_destroy);
25 
26 struct sec_path *secpath_dup(struct sec_path *src)
27 {
28 	struct sec_path *sp;
29 
30 	sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
31 	if (!sp)
32 		return NULL;
33 
34 	sp->len = 0;
35 	if (src) {
36 		int i;
37 
38 		memcpy(sp, src, sizeof(*sp));
39 		for (i = 0; i < sp->len; i++)
40 			xfrm_state_hold(sp->xvec[i]);
41 	}
42 	atomic_set(&sp->refcnt, 1);
43 	return sp;
44 }
45 EXPORT_SYMBOL(secpath_dup);
46 
47 /* Fetch spi and seq from ipsec header */
48 
49 int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
50 {
51 	int offset, offset_seq;
52 
53 	switch (nexthdr) {
54 	case IPPROTO_AH:
55 		offset = offsetof(struct ip_auth_hdr, spi);
56 		offset_seq = offsetof(struct ip_auth_hdr, seq_no);
57 		break;
58 	case IPPROTO_ESP:
59 		offset = offsetof(struct ip_esp_hdr, spi);
60 		offset_seq = offsetof(struct ip_esp_hdr, seq_no);
61 		break;
62 	case IPPROTO_COMP:
63 		if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
64 			return -EINVAL;
65 		*spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2)));
66 		*seq = 0;
67 		return 0;
68 	default:
69 		return 1;
70 	}
71 
72 	if (!pskb_may_pull(skb, 16))
73 		return -EINVAL;
74 
75 	*spi = *(__be32*)(skb_transport_header(skb) + offset);
76 	*seq = *(__be32*)(skb_transport_header(skb) + offset_seq);
77 	return 0;
78 }
79 EXPORT_SYMBOL(xfrm_parse_spi);
80 
81 void __init xfrm_input_init(void)
82 {
83 	secpath_cachep = kmem_cache_create("secpath_cache",
84 					   sizeof(struct sec_path),
85 					   0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
86 					   NULL);
87 }
88