Root/
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 | |
7 | #include <linux/gfp.h> |
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 | |
18 | static inline void ipip_ecn_decapsulate(struct sk_buff *skb) |
19 | { |
20 | struct iphdr *inner_iph = ipip_hdr(skb); |
21 | |
22 | if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos)) |
23 | IP_ECN_set_ce(inner_iph); |
24 | } |
25 | |
26 | /* Add encapsulation header. |
27 | * |
28 | * The top IP header will be constructed per RFC 2401. |
29 | */ |
30 | static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) |
31 | { |
32 | struct dst_entry *dst = skb_dst(skb); |
33 | struct iphdr *top_iph; |
34 | int flags; |
35 | |
36 | skb_set_network_header(skb, -x->props.header_len); |
37 | skb->mac_header = skb->network_header + |
38 | offsetof(struct iphdr, protocol); |
39 | skb->transport_header = skb->network_header + sizeof(*top_iph); |
40 | top_iph = ip_hdr(skb); |
41 | |
42 | top_iph->ihl = 5; |
43 | top_iph->version = 4; |
44 | |
45 | top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family); |
46 | |
47 | /* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */ |
48 | if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP) |
49 | top_iph->tos = 0; |
50 | else |
51 | top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos; |
52 | top_iph->tos = INET_ECN_encapsulate(top_iph->tos, |
53 | XFRM_MODE_SKB_CB(skb)->tos); |
54 | |
55 | flags = x->props.flags; |
56 | if (flags & XFRM_STATE_NOECN) |
57 | IP_ECN_clear(top_iph); |
58 | |
59 | top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ? |
60 | 0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF)); |
61 | ip_select_ident(skb, dst->child, NULL); |
62 | |
63 | top_iph->ttl = ip4_dst_hoplimit(dst->child); |
64 | |
65 | top_iph->saddr = x->props.saddr.a4; |
66 | top_iph->daddr = x->id.daddr.a4; |
67 | |
68 | return 0; |
69 | } |
70 | |
71 | static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) |
72 | { |
73 | int err = -EINVAL; |
74 | |
75 | if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP) |
76 | goto out; |
77 | |
78 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) |
79 | goto out; |
80 | |
81 | err = skb_unclone(skb, GFP_ATOMIC); |
82 | if (err) |
83 | goto out; |
84 | |
85 | if (x->props.flags & XFRM_STATE_DECAP_DSCP) |
86 | ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb)); |
87 | if (!(x->props.flags & XFRM_STATE_NOECN)) |
88 | ipip_ecn_decapsulate(skb); |
89 | |
90 | skb_reset_network_header(skb); |
91 | skb_mac_header_rebuild(skb); |
92 | |
93 | err = 0; |
94 | |
95 | out: |
96 | return err; |
97 | } |
98 | |
99 | static struct xfrm_mode xfrm4_tunnel_mode = { |
100 | .input2 = xfrm4_mode_tunnel_input, |
101 | .input = xfrm_prepare_input, |
102 | .output2 = xfrm4_mode_tunnel_output, |
103 | .output = xfrm4_prepare_output, |
104 | .owner = THIS_MODULE, |
105 | .encap = XFRM_MODE_TUNNEL, |
106 | .flags = XFRM_MODE_FLAG_TUNNEL, |
107 | }; |
108 | |
109 | static int __init xfrm4_mode_tunnel_init(void) |
110 | { |
111 | return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET); |
112 | } |
113 | |
114 | static void __exit xfrm4_mode_tunnel_exit(void) |
115 | { |
116 | int err; |
117 | |
118 | err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET); |
119 | BUG_ON(err); |
120 | } |
121 | |
122 | module_init(xfrm4_mode_tunnel_init); |
123 | module_exit(xfrm4_mode_tunnel_exit); |
124 | MODULE_LICENSE("GPL"); |
125 | MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL); |
126 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9