Commit | Line | Data |
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b59f45d0 HX |
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 | ||
5a0e3ad6 | 8 | #include <linux/gfp.h> |
b59f45d0 HX |
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> | |
abbf46ae | 17 | #include <net/ip6_route.h> |
b59f45d0 HX |
18 | #include <net/ipv6.h> |
19 | #include <net/xfrm.h> | |
20 | ||
21 | static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) | |
22 | { | |
b71d1d42 | 23 | const struct ipv6hdr *outer_iph = ipv6_hdr(skb); |
39b89160 | 24 | struct ipv6hdr *inner_iph = ipipv6_hdr(skb); |
b59f45d0 HX |
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 | * | |
ceb1eec8 | 32 | * The top IP header will be constructed per RFC 2401. |
b59f45d0 | 33 | */ |
195ad6a3 | 34 | static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 | 35 | { |
adf30907 | 36 | struct dst_entry *dst = skb_dst(skb); |
36cf9acf | 37 | struct ipv6hdr *top_iph; |
b59f45d0 HX |
38 | int dsfield; |
39 | ||
7b277b1a | 40 | skb_set_network_header(skb, -x->props.header_len); |
37fedd3a HX |
41 | skb->mac_header = skb->network_header + |
42 | offsetof(struct ipv6hdr, nexthdr); | |
36cf9acf | 43 | skb->transport_header = skb->network_header + sizeof(*top_iph); |
0660e03f | 44 | top_iph = ipv6_hdr(skb); |
b59f45d0 HX |
45 | |
46 | top_iph->version = 6; | |
36cf9acf HX |
47 | |
48 | memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl, | |
49 | sizeof(top_iph->flow_lbl)); | |
adf30907 | 50 | top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family); |
36cf9acf | 51 | |
a947b0a9 ND |
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); | |
b59f45d0 HX |
57 | if (x->props.flags & XFRM_STATE_NOECN) |
58 | dsfield &= ~INET_ECN_MASK; | |
59 | ipv6_change_dsfield(top_iph, 0, dsfield); | |
abbf46ae | 60 | top_iph->hop_limit = ip6_dst_hoplimit(dst->child); |
4e3fd7a0 AD |
61 | top_iph->saddr = *(struct in6_addr *)&x->props.saddr; |
62 | top_iph->daddr = *(struct in6_addr *)&x->id.daddr; | |
b59f45d0 HX |
63 | return 0; |
64 | } | |
65 | ||
212e5601 SK |
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 | ||
195ad6a3 | 72 | static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 HX |
73 | { |
74 | int err = -EINVAL; | |
75 | ||
227620e2 | 76 | if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6) |
b59f45d0 HX |
77 | goto out; |
78 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
79 | goto out; | |
80 | ||
0d4bfa29 | 81 | err = skb_unclone(skb, GFP_ATOMIC); |
82 | if (err) | |
b59f45d0 HX |
83 | goto out; |
84 | ||
227620e2 HX |
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 | ||
c1d2bbe1 | 91 | skb_reset_network_header(skb); |
03606895 ED |
92 | skb_mac_header_rebuild(skb); |
93 | ||
b59f45d0 HX |
94 | err = 0; |
95 | ||
96 | out: | |
97 | return err; | |
98 | } | |
99 | ||
100 | static struct xfrm_mode xfrm6_tunnel_mode = { | |
195ad6a3 | 101 | .input2 = xfrm6_mode_tunnel_input, |
227620e2 | 102 | .input = xfrm_prepare_input, |
195ad6a3 | 103 | .output2 = xfrm6_mode_tunnel_output, |
36cf9acf | 104 | .output = xfrm6_prepare_output, |
b59f45d0 HX |
105 | .owner = THIS_MODULE, |
106 | .encap = XFRM_MODE_TUNNEL, | |
1bfcb10f | 107 | .flags = XFRM_MODE_FLAG_TUNNEL, |
b59f45d0 HX |
108 | }; |
109 | ||
195ad6a3 | 110 | static int __init xfrm6_mode_tunnel_init(void) |
b59f45d0 HX |
111 | { |
112 | return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); | |
113 | } | |
114 | ||
195ad6a3 | 115 | static void __exit xfrm6_mode_tunnel_exit(void) |
b59f45d0 HX |
116 | { |
117 | int err; | |
118 | ||
119 | err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); | |
120 | BUG_ON(err); | |
121 | } | |
122 | ||
195ad6a3 HX |
123 | module_init(xfrm6_mode_tunnel_init); |
124 | module_exit(xfrm6_mode_tunnel_exit); | |
b59f45d0 HX |
125 | MODULE_LICENSE("GPL"); |
126 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |