tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
22static void xfrm6_beet_make_header(struct sk_buff *skb)
23{
24 struct ipv6hdr *iph = ipv6_hdr(skb);
25
26 iph->version = 6;
27
28 memcpy(iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
29 sizeof(iph->flow_lbl));
30 iph->nexthdr = XFRM_MODE_SKB_CB(skb)->protocol;
31
32 ipv6_change_dsfield(iph, 0, XFRM_MODE_SKB_CB(skb)->tos);
33 iph->hop_limit = XFRM_MODE_SKB_CB(skb)->ttl;
34}
35
36/* Add encapsulation header.
37 *
38 * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
39 */
40static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
41{
42 struct ipv6hdr *top_iph;
43 struct ip_beet_phdr *ph;
44 int optlen, hdr_len;
45
46 hdr_len = 0;
47 optlen = XFRM_MODE_SKB_CB(skb)->optlen;
48 if (unlikely(optlen))
49 hdr_len += IPV4_BEET_PHMAXLEN - (optlen & 4);
50
51 skb_set_network_header(skb, -x->props.header_len - hdr_len);
52 if (x->sel.family != AF_INET6)
53 skb->network_header += IPV4_BEET_PHMAXLEN;
54 skb->mac_header = skb->network_header +
55 offsetof(struct ipv6hdr, nexthdr);
56 skb->transport_header = skb->network_header + sizeof(*top_iph);
57 ph = (struct ip_beet_phdr *)__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl-hdr_len);
58
59 xfrm6_beet_make_header(skb);
60
61 top_iph = ipv6_hdr(skb);
62 if (unlikely(optlen)) {
63
64 BUG_ON(optlen < 0);
65
66 ph->padlen = 4 - (optlen & 4);
67 ph->hdrlen = optlen / 8;
68 ph->nexthdr = top_iph->nexthdr;
69 if (ph->padlen)
70 memset(ph + 1, IPOPT_NOP, ph->padlen);
71
72 top_iph->nexthdr = IPPROTO_BEETPH;
73 }
74
75 ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
76 ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
77 return 0;
78}
79
80static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
81{
82 struct ipv6hdr *ip6h;
83 const unsigned char *old_mac;
84 int size = sizeof(struct ipv6hdr);
85 int err;
86
87 err = skb_cow_head(skb, size + skb->mac_len);
88 if (err)
89 goto out;
90
91 __skb_push(skb, size);
92 skb_reset_network_header(skb);
93
94 old_mac = skb_mac_header(skb);
95 skb_set_mac_header(skb, -skb->mac_len);
96 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
97
98 xfrm6_beet_make_header(skb);
99
100 ip6h = ipv6_hdr(skb);
101 ip6h->payload_len = htons(skb->len - size);
102 ipv6_addr_copy(&ip6h->daddr, (struct in6_addr *) &x->sel.daddr.a6);
103 ipv6_addr_copy(&ip6h->saddr, (struct in6_addr *) &x->sel.saddr.a6);
104 err = 0;
105out:
106 return err;
107}
108
109static struct xfrm_mode xfrm6_beet_mode = {
110 .input2 = xfrm6_beet_input,
111 .input = xfrm_prepare_input,
112 .output2 = xfrm6_beet_output,
113 .output = xfrm6_prepare_output,
114 .owner = THIS_MODULE,
115 .encap = XFRM_MODE_BEET,
116 .flags = XFRM_MODE_FLAG_TUNNEL,
117};
118
119static int __init xfrm6_beet_init(void)
120{
121 return xfrm_register_mode(&xfrm6_beet_mode, AF_INET6);
122}
123
124static void __exit xfrm6_beet_exit(void)
125{
126 int err;
127
128 err = xfrm_unregister_mode(&xfrm6_beet_mode, AF_INET6);
129 BUG_ON(err);
130}
131
132module_init(xfrm6_beet_init);
133module_exit(xfrm6_beet_exit);
134MODULE_LICENSE("GPL");
135MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_BEET);