1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
/*
* xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
*
* Copyright (C) 2002 USAGI/WIDE Project
* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/stringify.h>
#include <net/dsfield.h>
#include <net/dst.h>
#include <net/inet_ecn.h>
#include <net/ipv6.h>
#include <net/xfrm.h>
static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
struct ipv6hdr *outer_iph = ipv6_hdr(skb);
struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
IP6_ECN_set_ce(inner_iph);
}
static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb)
{
if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6_hdr(skb))))
IP_ECN_set_ce(ipip_hdr(skb));
}
/* Add encapsulation header.
*
* The top IP header will be constructed per RFC 2401.
*/
static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
struct ipv6hdr *iph, *top_iph;
int dsfield;
iph = ipv6_hdr(skb);
skb_set_network_header(skb, -x->props.header_len);
skb->mac_header = skb->network_header +
offsetof(struct ipv6hdr, nexthdr);
skb->transport_header = skb->network_header + sizeof(*iph);
top_iph = ipv6_hdr(skb);
top_iph->version = 6;
if (xdst->route->ops->family == AF_INET6) {
top_iph->priority = iph->priority;
top_iph->flow_lbl[0] = iph->flow_lbl[0];
top_iph->flow_lbl[1] = iph->flow_lbl[1];
top_iph->flow_lbl[2] = iph->flow_lbl[2];
top_iph->nexthdr = IPPROTO_IPV6;
} else {
top_iph->priority = 0;
top_iph->flow_lbl[0] = 0;
top_iph->flow_lbl[1] = 0;
top_iph->flow_lbl[2] = 0;
top_iph->nexthdr = IPPROTO_IPIP;
}
dsfield = ipv6_get_dsfield(top_iph);
dsfield = INET_ECN_encapsulate(dsfield, dsfield);
if (x->props.flags & XFRM_STATE_NOECN)
dsfield &= ~INET_ECN_MASK;
ipv6_change_dsfield(top_iph, 0, dsfield);
top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
skb->protocol = htons(ETH_P_IPV6);
return 0;
}
static int xfrm6_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
int err = -EINVAL;
const unsigned char *old_mac;
const unsigned char *nh = skb_network_header(skb);
if (nh[IP6CB(skb)->nhoff] != IPPROTO_IPV6 &&
nh[IP6CB(skb)->nhoff] != IPPROTO_IPIP)
goto out;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto out;
if (skb_cloned(skb) &&
(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
goto out;
nh = skb_network_header(skb);
if (nh[IP6CB(skb)->nhoff] == IPPROTO_IPV6) {
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
ipv6_copy_dscp(ipv6_hdr(skb), ipipv6_hdr(skb));
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip6_ecn_decapsulate(skb);
} else {
if (!(x->props.flags & XFRM_STATE_NOECN))
ip6ip_ecn_decapsulate(skb);
skb->protocol = htons(ETH_P_IP);
}
old_mac = skb_mac_header(skb);
skb_set_mac_header(skb, -skb->mac_len);
memmove(skb_mac_header(skb), old_mac, skb->mac_len);
skb_reset_network_header(skb);
err = 0;
out:
return err;
}
static struct xfrm_mode xfrm6_tunnel_mode = {
.input = xfrm6_tunnel_input,
.output = xfrm6_tunnel_output,
.owner = THIS_MODULE,
.encap = XFRM_MODE_TUNNEL,
.flags = XFRM_MODE_FLAG_TUNNEL,
};
static int __init xfrm6_tunnel_init(void)
{
return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
}
static void __exit xfrm6_tunnel_exit(void)
{
int err;
err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
BUG_ON(err);
}
module_init(xfrm6_tunnel_init);
module_exit(xfrm6_tunnel_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
|
