]>
Commit | Line | Data |
---|---|---|
b59f45d0 HX |
1 | /* |
2 | * xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4. | |
3 | * | |
4 | * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au> | |
5 | */ | |
6 | ||
5a0e3ad6 | 7 | #include <linux/gfp.h> |
b59f45d0 HX |
8 | #include <linux/init.h> |
9 | #include <linux/kernel.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/stringify.h> | |
13 | #include <net/dst.h> | |
14 | #include <net/inet_ecn.h> | |
15 | #include <net/ip.h> | |
16 | #include <net/xfrm.h> | |
17 | ||
b59f45d0 HX |
18 | /* Add encapsulation header. |
19 | * | |
ceb1eec8 | 20 | * The top IP header will be constructed per RFC 2401. |
b59f45d0 | 21 | */ |
195ad6a3 | 22 | static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 | 23 | { |
adf30907 | 24 | struct dst_entry *dst = skb_dst(skb); |
36cf9acf | 25 | struct iphdr *top_iph; |
b59f45d0 HX |
26 | int flags; |
27 | ||
f1bd7d65 IT |
28 | skb_set_inner_network_header(skb, skb_network_offset(skb)); |
29 | skb_set_inner_transport_header(skb, skb_transport_offset(skb)); | |
30 | ||
7b277b1a | 31 | skb_set_network_header(skb, -x->props.header_len); |
37fedd3a HX |
32 | skb->mac_header = skb->network_header + |
33 | offsetof(struct iphdr, protocol); | |
36cf9acf | 34 | skb->transport_header = skb->network_header + sizeof(*top_iph); |
eddc9ec5 | 35 | top_iph = ip_hdr(skb); |
b59f45d0 HX |
36 | |
37 | top_iph->ihl = 5; | |
38 | top_iph->version = 4; | |
39 | ||
adf30907 | 40 | top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family); |
c82f963e | 41 | |
a947b0a9 ND |
42 | /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */ |
43 | if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP) | |
44 | top_iph->tos = 0; | |
45 | else | |
46 | top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos; | |
47 | top_iph->tos = INET_ECN_encapsulate(top_iph->tos, | |
36cf9acf | 48 | XFRM_MODE_SKB_CB(skb)->tos); |
b59f45d0 | 49 | |
36cf9acf | 50 | flags = x->props.flags; |
b59f45d0 HX |
51 | if (flags & XFRM_STATE_NOECN) |
52 | IP_ECN_clear(top_iph); | |
53 | ||
36cf9acf | 54 | top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ? |
fe833fca | 55 | 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF)); |
b59f45d0 | 56 | |
b92cf4aa | 57 | top_iph->ttl = ip4_dst_hoplimit(xfrm_dst_child(dst)); |
b59f45d0 HX |
58 | |
59 | top_iph->saddr = x->props.saddr.a4; | |
60 | top_iph->daddr = x->id.daddr.a4; | |
b6a7719a | 61 | ip_select_ident(dev_net(dst->dev), skb, NULL); |
b59f45d0 | 62 | |
b59f45d0 HX |
63 | return 0; |
64 | } | |
65 | ||
b59f45d0 | 66 | static struct xfrm_mode xfrm4_tunnel_mode = { |
195ad6a3 | 67 | .output2 = xfrm4_mode_tunnel_output, |
b59f45d0 HX |
68 | .owner = THIS_MODULE, |
69 | .encap = XFRM_MODE_TUNNEL, | |
1bfcb10f | 70 | .flags = XFRM_MODE_FLAG_TUNNEL, |
b262a695 | 71 | .family = AF_INET, |
b59f45d0 HX |
72 | }; |
73 | ||
195ad6a3 | 74 | static int __init xfrm4_mode_tunnel_init(void) |
b59f45d0 | 75 | { |
b262a695 | 76 | return xfrm_register_mode(&xfrm4_tunnel_mode); |
b59f45d0 HX |
77 | } |
78 | ||
195ad6a3 | 79 | static void __exit xfrm4_mode_tunnel_exit(void) |
b59f45d0 | 80 | { |
b262a695 | 81 | xfrm_unregister_mode(&xfrm4_tunnel_mode); |
b59f45d0 HX |
82 | } |
83 | ||
195ad6a3 HX |
84 | module_init(xfrm4_mode_tunnel_init); |
85 | module_exit(xfrm4_mode_tunnel_exit); | |
b59f45d0 HX |
86 | MODULE_LICENSE("GPL"); |
87 | MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL); |