2 * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
4 * Copyright (C) 2002 USAGI/WIDE Project
5 * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
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>
16 #include <net/inet_ecn.h>
17 #include <net/ip6_route.h>
21 static inline void ipip6_ecn_decapsulate(struct sk_buff
*skb
)
23 struct ipv6hdr
*inner_iph
= ipipv6_hdr(skb
);
25 if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb
)->tos
))
26 IP6_ECN_set_ce(skb
, inner_iph
);
29 /* Add encapsulation header.
31 * The top IP header will be constructed per RFC 2401.
33 static int xfrm6_mode_tunnel_output(struct xfrm_state
*x
, struct sk_buff
*skb
)
35 struct dst_entry
*dst
= skb_dst(skb
);
36 struct ipv6hdr
*top_iph
;
39 skb_set_network_header(skb
, -x
->props
.header_len
);
40 skb
->mac_header
= skb
->network_header
+
41 offsetof(struct ipv6hdr
, nexthdr
);
42 skb
->transport_header
= skb
->network_header
+ sizeof(*top_iph
);
43 top_iph
= ipv6_hdr(skb
);
47 memcpy(top_iph
->flow_lbl
, XFRM_MODE_SKB_CB(skb
)->flow_lbl
,
48 sizeof(top_iph
->flow_lbl
));
49 top_iph
->nexthdr
= xfrm_af2proto(skb_dst(skb
)->ops
->family
);
51 if (x
->props
.extra_flags
& XFRM_SA_XFLAG_DONT_ENCAP_DSCP
)
54 dsfield
= XFRM_MODE_SKB_CB(skb
)->tos
;
55 dsfield
= INET_ECN_encapsulate(dsfield
, XFRM_MODE_SKB_CB(skb
)->tos
);
56 if (x
->props
.flags
& XFRM_STATE_NOECN
)
57 dsfield
&= ~INET_ECN_MASK
;
58 ipv6_change_dsfield(top_iph
, 0, dsfield
);
59 top_iph
->hop_limit
= ip6_dst_hoplimit(dst
->child
);
60 top_iph
->saddr
= *(struct in6_addr
*)&x
->props
.saddr
;
61 top_iph
->daddr
= *(struct in6_addr
*)&x
->id
.daddr
;
65 #define for_each_input_rcu(head, handler) \
66 for (handler = rcu_dereference(head); \
68 handler = rcu_dereference(handler->next))
71 static int xfrm6_mode_tunnel_input(struct xfrm_state
*x
, struct sk_buff
*skb
)
75 if (XFRM_MODE_SKB_CB(skb
)->protocol
!= IPPROTO_IPV6
)
77 if (!pskb_may_pull(skb
, sizeof(struct ipv6hdr
)))
80 err
= skb_unclone(skb
, GFP_ATOMIC
);
84 if (x
->props
.flags
& XFRM_STATE_DECAP_DSCP
)
85 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb
)),
87 if (!(x
->props
.flags
& XFRM_STATE_NOECN
))
88 ipip6_ecn_decapsulate(skb
);
90 skb_reset_network_header(skb
);
91 skb_mac_header_rebuild(skb
);
99 static struct sk_buff
*xfrm6_mode_tunnel_gso_segment(struct xfrm_state
*x
,
101 netdev_features_t features
)
103 __skb_push(skb
, skb
->mac_len
);
104 return skb_mac_gso_segment(skb
, features
);
108 static void xfrm6_mode_tunnel_xmit(struct xfrm_state
*x
, struct sk_buff
*skb
)
110 struct xfrm_offload
*xo
= xfrm_offload(skb
);
112 if (xo
->flags
& XFRM_GSO_SEGMENT
) {
113 skb
->network_header
= skb
->network_header
- x
->props
.header_len
;
114 skb
->transport_header
= skb
->network_header
+ sizeof(struct ipv6hdr
);
117 skb_reset_mac_len(skb
);
118 pskb_pull(skb
, skb
->mac_len
+ x
->props
.header_len
);
121 static struct xfrm_mode xfrm6_tunnel_mode
= {
122 .input2
= xfrm6_mode_tunnel_input
,
123 .input
= xfrm_prepare_input
,
124 .output2
= xfrm6_mode_tunnel_output
,
125 .output
= xfrm6_prepare_output
,
126 .gso_segment
= xfrm6_mode_tunnel_gso_segment
,
127 .xmit
= xfrm6_mode_tunnel_xmit
,
128 .owner
= THIS_MODULE
,
129 .encap
= XFRM_MODE_TUNNEL
,
130 .flags
= XFRM_MODE_FLAG_TUNNEL
,
133 static int __init
xfrm6_mode_tunnel_init(void)
135 return xfrm_register_mode(&xfrm6_tunnel_mode
, AF_INET6
);
138 static void __exit
xfrm6_mode_tunnel_exit(void)
142 err
= xfrm_unregister_mode(&xfrm6_tunnel_mode
, AF_INET6
);
146 module_init(xfrm6_mode_tunnel_init
);
147 module_exit(xfrm6_mode_tunnel_exit
);
148 MODULE_LICENSE("GPL");
149 MODULE_ALIAS_XFRM_MODE(AF_INET6
, XFRM_MODE_TUNNEL
);