net: remove ipv6_addr_copy()
[linux-3.10.git] / net / ipv6 / xfrm6_mode_tunnel.c
1 /*
2  * xfrm6_mode_tunnel.c - Tunnel mode encapsulation for IPv6.
3  *
4  * Copyright (C) 2002 USAGI/WIDE Project
5  * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
6  */
7
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
21 static 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 /* Add encapsulation header.
31  *
32  * The top IP header will be constructed per RFC 2401.
33  */
34 static 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         dsfield = XFRM_MODE_SKB_CB(skb)->tos;
53         dsfield = INET_ECN_encapsulate(dsfield, dsfield);
54         if (x->props.flags & XFRM_STATE_NOECN)
55                 dsfield &= ~INET_ECN_MASK;
56         ipv6_change_dsfield(top_iph, 0, dsfield);
57         top_iph->hop_limit = ip6_dst_hoplimit(dst->child);
58         top_iph->saddr = *(struct in6_addr *)&x->props.saddr;
59         top_iph->daddr = *(struct in6_addr *)&x->id.daddr;
60         return 0;
61 }
62
63 static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
64 {
65         int err = -EINVAL;
66         const unsigned char *old_mac;
67
68         if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
69                 goto out;
70         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
71                 goto out;
72
73         if (skb_cloned(skb) &&
74             (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
75                 goto out;
76
77         if (x->props.flags & XFRM_STATE_DECAP_DSCP)
78                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)),
79                                ipipv6_hdr(skb));
80         if (!(x->props.flags & XFRM_STATE_NOECN))
81                 ipip6_ecn_decapsulate(skb);
82
83         old_mac = skb_mac_header(skb);
84         skb_set_mac_header(skb, -skb->mac_len);
85         memmove(skb_mac_header(skb), old_mac, skb->mac_len);
86         skb_reset_network_header(skb);
87         err = 0;
88
89 out:
90         return err;
91 }
92
93 static struct xfrm_mode xfrm6_tunnel_mode = {
94         .input2 = xfrm6_mode_tunnel_input,
95         .input = xfrm_prepare_input,
96         .output2 = xfrm6_mode_tunnel_output,
97         .output = xfrm6_prepare_output,
98         .owner = THIS_MODULE,
99         .encap = XFRM_MODE_TUNNEL,
100         .flags = XFRM_MODE_FLAG_TUNNEL,
101 };
102
103 static int __init xfrm6_mode_tunnel_init(void)
104 {
105         return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6);
106 }
107
108 static void __exit xfrm6_mode_tunnel_exit(void)
109 {
110         int err;
111
112         err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6);
113         BUG_ON(err);
114 }
115
116 module_init(xfrm6_mode_tunnel_init);
117 module_exit(xfrm6_mode_tunnel_exit);
118 MODULE_LICENSE("GPL");
119 MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL);