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 HX |
51 | |
52 | dsfield = XFRM_MODE_SKB_CB(skb)->tos; | |
b59f45d0 HX |
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); | |
abbf46ae | 57 | top_iph->hop_limit = ip6_dst_hoplimit(dst->child); |
b71d1d42 ED |
58 | ipv6_addr_copy(&top_iph->saddr, (const struct in6_addr *)&x->props.saddr); |
59 | ipv6_addr_copy(&top_iph->daddr, (const struct in6_addr *)&x->id.daddr); | |
b59f45d0 HX |
60 | return 0; |
61 | } | |
62 | ||
195ad6a3 | 63 | static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 HX |
64 | { |
65 | int err = -EINVAL; | |
39f69c6f | 66 | const unsigned char *old_mac; |
b59f45d0 | 67 | |
227620e2 | 68 | if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6) |
b59f45d0 HX |
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 | ||
227620e2 HX |
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 | ||
98e399f8 | 83 | old_mac = skb_mac_header(skb); |
39f69c6f | 84 | skb_set_mac_header(skb, -skb->mac_len); |
98e399f8 | 85 | memmove(skb_mac_header(skb), old_mac, skb->mac_len); |
c1d2bbe1 | 86 | skb_reset_network_header(skb); |
b59f45d0 HX |
87 | err = 0; |
88 | ||
89 | out: | |
90 | return err; | |
91 | } | |
92 | ||
93 | static struct xfrm_mode xfrm6_tunnel_mode = { | |
195ad6a3 | 94 | .input2 = xfrm6_mode_tunnel_input, |
227620e2 | 95 | .input = xfrm_prepare_input, |
195ad6a3 | 96 | .output2 = xfrm6_mode_tunnel_output, |
36cf9acf | 97 | .output = xfrm6_prepare_output, |
b59f45d0 HX |
98 | .owner = THIS_MODULE, |
99 | .encap = XFRM_MODE_TUNNEL, | |
1bfcb10f | 100 | .flags = XFRM_MODE_FLAG_TUNNEL, |
b59f45d0 HX |
101 | }; |
102 | ||
195ad6a3 | 103 | static int __init xfrm6_mode_tunnel_init(void) |
b59f45d0 HX |
104 | { |
105 | return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); | |
106 | } | |
107 | ||
195ad6a3 | 108 | static void __exit xfrm6_mode_tunnel_exit(void) |
b59f45d0 HX |
109 | { |
110 | int err; | |
111 | ||
112 | err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); | |
113 | BUG_ON(err); | |
114 | } | |
115 | ||
195ad6a3 HX |
116 | module_init(xfrm6_mode_tunnel_init); |
117 | module_exit(xfrm6_mode_tunnel_exit); | |
b59f45d0 HX |
118 | MODULE_LICENSE("GPL"); |
119 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |