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0a69452c DB |
1 | /* |
2 | * xfrm6_mode_beet.c - BEET mode encapsulation for IPv6. | |
3 | * | |
4 | * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com> | |
5 | * Miika Komu <miika@iki.fi> | |
6 | * Herbert Xu <herbert@gondor.apana.org.au> | |
7 | * Abhinav Pathak <abhinav.pathak@hiit.fi> | |
8 | * Jeff Ahrenholz <ahrenholz@gmail.com> | |
9 | */ | |
10 | ||
11 | #include <linux/init.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/skbuff.h> | |
15 | #include <linux/stringify.h> | |
16 | #include <net/dsfield.h> | |
17 | #include <net/dst.h> | |
18 | #include <net/inet_ecn.h> | |
19 | #include <net/ipv6.h> | |
20 | #include <net/xfrm.h> | |
21 | ||
22 | /* Add encapsulation header. | |
23 | * | |
24 | * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt. | |
25 | * The following fields in it shall be filled in by x->type->output: | |
26 | * payload_len | |
27 | * | |
28 | * On exit, skb->h will be set to the start of the encapsulation header to be | |
007f0211 HX |
29 | * filled in by x->type->output and the mac header will be set to the |
30 | * nextheader field of the extension header directly preceding the | |
31 | * encapsulation header, or in its absence, that of the top IP header. | |
32 | * The value of skb->data and the network header will always point to the | |
33 | * top IP header. | |
0a69452c DB |
34 | */ |
35 | static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb) | |
36 | { | |
37 | struct ipv6hdr *iph, *top_iph; | |
38 | u8 *prevhdr; | |
39 | int hdr_len; | |
40 | ||
41 | skb_push(skb, x->props.header_len); | |
0660e03f | 42 | iph = ipv6_hdr(skb); |
0a69452c DB |
43 | |
44 | hdr_len = ip6_find_1stfragopt(skb, &prevhdr); | |
0a69452c DB |
45 | memmove(skb->data, iph, hdr_len); |
46 | ||
bee0b40c | 47 | skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data); |
c1d2bbe1 | 48 | skb_reset_network_header(skb); |
bee0b40c | 49 | skb_set_transport_header(skb, hdr_len); |
0660e03f | 50 | top_iph = ipv6_hdr(skb); |
0a69452c DB |
51 | |
52 | ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr); | |
53 | ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr); | |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb) | |
59 | { | |
60 | struct ipv6hdr *ip6h; | |
39f69c6f | 61 | const unsigned char *old_mac; |
0a69452c DB |
62 | int size = sizeof(struct ipv6hdr); |
63 | int err = -EINVAL; | |
64 | ||
65 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
66 | goto out; | |
67 | ||
68 | skb_push(skb, size); | |
d56f90a7 | 69 | memmove(skb->data, skb_network_header(skb), size); |
c1d2bbe1 | 70 | skb_reset_network_header(skb); |
0a69452c | 71 | |
98e399f8 | 72 | old_mac = skb_mac_header(skb); |
39f69c6f | 73 | skb_set_mac_header(skb, -skb->mac_len); |
98e399f8 | 74 | memmove(skb_mac_header(skb), old_mac, skb->mac_len); |
0a69452c | 75 | |
0660e03f | 76 | ip6h = ipv6_hdr(skb); |
0a69452c DB |
77 | ip6h->payload_len = htons(skb->len - size); |
78 | ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6); | |
79 | ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6); | |
80 | err = 0; | |
81 | out: | |
82 | return err; | |
83 | } | |
84 | ||
85 | static struct xfrm_mode xfrm6_beet_mode = { | |
86 | .input = xfrm6_beet_input, | |
87 | .output = xfrm6_beet_output, | |
88 | .owner = THIS_MODULE, | |
89 | .encap = XFRM_MODE_BEET, | |
90 | }; | |
91 | ||
92 | static int __init xfrm6_beet_init(void) | |
93 | { | |
94 | return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6); | |
95 | } | |
96 | ||
97 | static void __exit xfrm6_beet_exit(void) | |
98 | { | |
99 | int err; | |
100 | ||
101 | err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6); | |
102 | BUG_ON(err); | |
103 | } | |
104 | ||
105 | module_init(xfrm6_beet_init); | |
106 | module_exit(xfrm6_beet_exit); | |
107 | MODULE_LICENSE("GPL"); | |
108 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET); |