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8#include <linux/gfp.h>
9#include <linux/init.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/skbuff.h>
13#include <linux/stringify.h>
14#include <net/dsfield.h>
15#include <net/dst.h>
16#include <net/inet_ecn.h>
17#include <net/ip6_route.h>
18#include <net/ipv6.h>
19#include <net/xfrm.h>
20
21static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
22{
23 const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
24 struct ipv6hdr *inner_iph = ipipv6_hdr(skb);
25
26 if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph)))
27 IP6_ECN_set_ce(inner_iph);
28}
29
30
31
32
33
34static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
35{
36 struct dst_entry *dst = skb_dst(skb);
37 struct ipv6hdr *top_iph;
38 int dsfield;
39
40 skb_set_network_header(skb, -x->props.header_len);
41 skb->mac_header = skb->network_header +
42 offsetof(struct ipv6hdr, nexthdr);
43 skb->transport_header = skb->network_header + sizeof(*top_iph);
44 top_iph = ipv6_hdr(skb);
45
46 top_iph->version = 6;
47
48 memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl,
49 sizeof(top_iph->flow_lbl));
50 top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family);
51
52 if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
53 dsfield = 0;
54 else
55 dsfield = XFRM_MODE_SKB_CB(skb)->tos;
56 dsfield = INET_ECN_encapsulate(dsfield, XFRM_MODE_SKB_CB(skb)->tos);
57 if (x->props.flags & XFRM_STATE_NOECN)
58 dsfield &= ~INET_ECN_MASK;
59 ipv6_change_dsfield(top_iph, 0, dsfield);
60 top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
61 top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
62 top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
63 return 0;
64}
65
66#define for_each_input_rcu(head, handler) \
67 for (handler = rcu_dereference(head); \
68 handler != NULL; \
69 handler = rcu_dereference(handler->next))
70
71
72static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
73{
74 int err = -EINVAL;
75
76 if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
77 goto out;
78 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
79 goto out;
80
81 err = skb_unclone(skb, GFP_ATOMIC);
82 if (err)
83 goto out;
84
85 if (x->props.flags & XFRM_STATE_DECAP_DSCP)
86 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
87 ipipv6_hdr(skb));
88 if (!(x->props.flags & XFRM_STATE_NOECN))
89 ipip6_ecn_decapsulate(skb);
90
91 skb_reset_network_header(skb);
92 skb_mac_header_rebuild(skb);
93
94 err = 0;
95
96out:
97 return err;
98}
99
100static struct xfrm_mode xfrm6_tunnel_mode = {
101 .input2 = xfrm6_mode_tunnel_input,
102 .input = xfrm_prepare_input,
103 .output2 = xfrm6_mode_tunnel_output,
104 .output = xfrm6_prepare_output,
105 .owner = THIS_MODULE,
106 .encap = XFRM_MODE_TUNNEL,
107 .flags = XFRM_MODE_FLAG_TUNNEL,
108};
109
110static int __init xfrm6_mode_tunnel_init(void)
111{
112 return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
113}
114
115static void __exit xfrm6_mode_tunnel_exit(void)
116{
117 int err;
118
119 err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
120 BUG_ON(err);
121}
122
123module_init(xfrm6_mode_tunnel_init);
124module_exit(xfrm6_mode_tunnel_exit);
125MODULE_LICENSE("GPL");
126MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);
127