1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
3 * (C) 2008 Patrick McHardy <kaber@trash.net>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/types.h>
11 #include <linux/init.h>
13 #include <linux/udp.h>
15 #include <linux/netfilter.h>
16 #include <net/netfilter/nf_nat.h>
17 #include <net/netfilter/nf_nat_protocol.h>
19 static u_int16_t udplite_port_rover
;
22 udplite_unique_tuple(struct nf_conntrack_tuple
*tuple
,
23 const struct nf_nat_range
*range
,
24 enum nf_nat_manip_type maniptype
,
25 const struct nf_conn
*ct
)
27 return nf_nat_proto_unique_tuple(tuple
, range
, maniptype
, ct
,
32 udplite_manip_pkt(struct sk_buff
*skb
,
33 unsigned int iphdroff
,
34 const struct nf_conntrack_tuple
*tuple
,
35 enum nf_nat_manip_type maniptype
)
37 const struct iphdr
*iph
= (struct iphdr
*)(skb
->data
+ iphdroff
);
39 unsigned int hdroff
= iphdroff
+ iph
->ihl
*4;
41 __be16
*portptr
, newport
;
43 if (!skb_make_writable(skb
, hdroff
+ sizeof(*hdr
)))
46 iph
= (struct iphdr
*)(skb
->data
+ iphdroff
);
47 hdr
= (struct udphdr
*)(skb
->data
+ hdroff
);
49 if (maniptype
== IP_NAT_MANIP_SRC
) {
50 /* Get rid of src ip and src pt */
52 newip
= tuple
->src
.u3
.ip
;
53 newport
= tuple
->src
.u
.udp
.port
;
54 portptr
= &hdr
->source
;
56 /* Get rid of dst ip and dst pt */
58 newip
= tuple
->dst
.u3
.ip
;
59 newport
= tuple
->dst
.u
.udp
.port
;
63 inet_proto_csum_replace4(&hdr
->check
, skb
, oldip
, newip
, 1);
64 inet_proto_csum_replace2(&hdr
->check
, skb
, *portptr
, newport
, 0);
66 hdr
->check
= CSUM_MANGLED_0
;
72 static const struct nf_nat_protocol nf_nat_protocol_udplite
= {
73 .protonum
= IPPROTO_UDPLITE
,
75 .manip_pkt
= udplite_manip_pkt
,
76 .in_range
= nf_nat_proto_in_range
,
77 .unique_tuple
= udplite_unique_tuple
,
78 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
79 .range_to_nlattr
= nf_nat_proto_range_to_nlattr
,
80 .nlattr_to_range
= nf_nat_proto_nlattr_to_range
,
84 static int __init
nf_nat_proto_udplite_init(void)
86 return nf_nat_protocol_register(&nf_nat_protocol_udplite
);
89 static void __exit
nf_nat_proto_udplite_fini(void)
91 nf_nat_protocol_unregister(&nf_nat_protocol_udplite
);
94 module_init(nf_nat_proto_udplite_init
);
95 module_exit(nf_nat_proto_udplite_fini
);
97 MODULE_LICENSE("GPL");
98 MODULE_DESCRIPTION("UDP-Lite NAT protocol helper");
99 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");