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> | |
17 | #include <net/ipv6.h> | |
18 | #include <net/xfrm.h> | |
19 | ||
20 | static inline void ipip6_ecn_decapsulate(struct sk_buff *skb) | |
21 | { | |
0660e03f | 22 | struct ipv6hdr *outer_iph = ipv6_hdr(skb); |
39b89160 | 23 | struct ipv6hdr *inner_iph = ipipv6_hdr(skb); |
b59f45d0 HX |
24 | |
25 | if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) | |
26 | IP6_ECN_set_ce(inner_iph); | |
27 | } | |
28 | ||
29 | /* Add encapsulation header. | |
30 | * | |
ceb1eec8 | 31 | * The top IP header will be constructed per RFC 2401. |
b59f45d0 | 32 | */ |
195ad6a3 | 33 | static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 | 34 | { |
adf30907 | 35 | struct dst_entry *dst = skb_dst(skb); |
36cf9acf | 36 | struct ipv6hdr *top_iph; |
b59f45d0 HX |
37 | int dsfield; |
38 | ||
7b277b1a | 39 | skb_set_network_header(skb, -x->props.header_len); |
37fedd3a HX |
40 | skb->mac_header = skb->network_header + |
41 | offsetof(struct ipv6hdr, nexthdr); | |
36cf9acf | 42 | skb->transport_header = skb->network_header + sizeof(*top_iph); |
0660e03f | 43 | top_iph = ipv6_hdr(skb); |
b59f45d0 HX |
44 | |
45 | top_iph->version = 6; | |
36cf9acf HX |
46 | |
47 | memcpy(top_iph->flow_lbl, XFRM_MODE_SKB_CB(skb)->flow_lbl, | |
48 | sizeof(top_iph->flow_lbl)); | |
adf30907 | 49 | top_iph->nexthdr = xfrm_af2proto(skb_dst(skb)->ops->family); |
36cf9acf HX |
50 | |
51 | dsfield = XFRM_MODE_SKB_CB(skb)->tos; | |
b59f45d0 HX |
52 | dsfield = INET_ECN_encapsulate(dsfield, dsfield); |
53 | if (x->props.flags & XFRM_STATE_NOECN) | |
54 | dsfield &= ~INET_ECN_MASK; | |
55 | ipv6_change_dsfield(top_iph, 0, dsfield); | |
b59f45d0 HX |
56 | top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT); |
57 | ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr); | |
58 | ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr); | |
59 | return 0; | |
60 | } | |
61 | ||
195ad6a3 | 62 | static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 HX |
63 | { |
64 | int err = -EINVAL; | |
39f69c6f | 65 | const unsigned char *old_mac; |
b59f45d0 | 66 | |
227620e2 | 67 | if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6) |
b59f45d0 HX |
68 | goto out; |
69 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
70 | goto out; | |
71 | ||
72 | if (skb_cloned(skb) && | |
73 | (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) | |
74 | goto out; | |
75 | ||
227620e2 HX |
76 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
77 | ipv6_copy_dscp(ipv6_get_dsfield(ipv6_hdr(skb)), | |
78 | ipipv6_hdr(skb)); | |
79 | if (!(x->props.flags & XFRM_STATE_NOECN)) | |
80 | ipip6_ecn_decapsulate(skb); | |
81 | ||
98e399f8 | 82 | old_mac = skb_mac_header(skb); |
39f69c6f | 83 | skb_set_mac_header(skb, -skb->mac_len); |
98e399f8 | 84 | memmove(skb_mac_header(skb), old_mac, skb->mac_len); |
c1d2bbe1 | 85 | skb_reset_network_header(skb); |
b59f45d0 HX |
86 | err = 0; |
87 | ||
88 | out: | |
89 | return err; | |
90 | } | |
91 | ||
92 | static struct xfrm_mode xfrm6_tunnel_mode = { | |
195ad6a3 | 93 | .input2 = xfrm6_mode_tunnel_input, |
227620e2 | 94 | .input = xfrm_prepare_input, |
195ad6a3 | 95 | .output2 = xfrm6_mode_tunnel_output, |
36cf9acf | 96 | .output = xfrm6_prepare_output, |
b59f45d0 HX |
97 | .owner = THIS_MODULE, |
98 | .encap = XFRM_MODE_TUNNEL, | |
1bfcb10f | 99 | .flags = XFRM_MODE_FLAG_TUNNEL, |
b59f45d0 HX |
100 | }; |
101 | ||
195ad6a3 | 102 | static int __init xfrm6_mode_tunnel_init(void) |
b59f45d0 HX |
103 | { |
104 | return xfrm_register_mode(&xfrm6_tunnel_mode, AF_INET6); | |
105 | } | |
106 | ||
195ad6a3 | 107 | static void __exit xfrm6_mode_tunnel_exit(void) |
b59f45d0 HX |
108 | { |
109 | int err; | |
110 | ||
111 | err = xfrm_unregister_mode(&xfrm6_tunnel_mode, AF_INET6); | |
112 | BUG_ON(err); | |
113 | } | |
114 | ||
195ad6a3 HX |
115 | module_init(xfrm6_mode_tunnel_init); |
116 | module_exit(xfrm6_mode_tunnel_exit); | |
b59f45d0 HX |
117 | MODULE_LICENSE("GPL"); |
118 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TUNNEL); |