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>
12 #include <linux/udp.h>
14 #include <linux/netfilter.h>
15 #include <linux/module.h>
16 #include <net/netfilter/nf_nat.h>
17 #include <net/netfilter/nf_nat_l3proto.h>
18 #include <net/netfilter/nf_nat_l4proto.h>
21 udplite_unique_tuple(const struct nf_nat_l3proto *l3proto,
22 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 nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct);
31 udplite_manip_pkt(struct sk_buff *skb,
32 const struct nf_nat_l3proto *l3proto,
33 unsigned int iphdroff, unsigned int hdroff,
34 const struct nf_conntrack_tuple *tuple,
35 enum nf_nat_manip_type maniptype)
38 __be16 *portptr, newport;
40 if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
43 hdr = (struct udphdr *)(skb->data + hdroff);
45 if (maniptype == NF_NAT_MANIP_SRC) {
46 /* Get rid of source port */
47 newport = tuple->src.u.udp.port;
48 portptr = &hdr->source;
50 /* Get rid of dst port */
51 newport = tuple->dst.u.udp.port;
55 l3proto->csum_update(skb, iphdroff, &hdr->check, tuple, maniptype);
56 inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, false);
58 hdr->check = CSUM_MANGLED_0;
64 static const struct nf_nat_l4proto nf_nat_l4proto_udplite = {
65 .l4proto = IPPROTO_UDPLITE,
66 .manip_pkt = udplite_manip_pkt,
67 .in_range = nf_nat_l4proto_in_range,
68 .unique_tuple = udplite_unique_tuple,
69 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
70 .nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
74 static int __init nf_nat_proto_udplite_init(void)
78 err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
81 err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_udplite);
87 nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
92 static void __exit nf_nat_proto_udplite_fini(void)
94 nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_udplite);
95 nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite);
98 module_init(nf_nat_proto_udplite_init);
99 module_exit(nf_nat_proto_udplite_fini);
101 MODULE_LICENSE("GPL");
102 MODULE_DESCRIPTION("UDP-Lite NAT protocol helper");
103 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");