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6185f870 PM |
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> | |
4 | * | |
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. | |
8 | */ | |
9 | ||
10 | #include <linux/types.h> | |
11 | #include <linux/init.h> | |
6185f870 PM |
12 | #include <linux/udp.h> |
13 | ||
14 | #include <linux/netfilter.h> | |
3a9a231d | 15 | #include <linux/module.h> |
6185f870 | 16 | #include <net/netfilter/nf_nat.h> |
c7232c99 PM |
17 | #include <net/netfilter/nf_nat_l3proto.h> |
18 | #include <net/netfilter/nf_nat_l4proto.h> | |
6185f870 | 19 | |
c7232c99 | 20 | static u16 udplite_port_rover; |
6185f870 | 21 | |
f43dc98b | 22 | static void |
c7232c99 PM |
23 | udplite_unique_tuple(const struct nf_nat_l3proto *l3proto, |
24 | struct nf_conntrack_tuple *tuple, | |
25 | const struct nf_nat_range *range, | |
6185f870 PM |
26 | enum nf_nat_manip_type maniptype, |
27 | const struct nf_conn *ct) | |
28 | { | |
c7232c99 PM |
29 | nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct, |
30 | &udplite_port_rover); | |
6185f870 PM |
31 | } |
32 | ||
f2ea825f | 33 | static bool |
6185f870 | 34 | udplite_manip_pkt(struct sk_buff *skb, |
c7232c99 PM |
35 | const struct nf_nat_l3proto *l3proto, |
36 | unsigned int iphdroff, unsigned int hdroff, | |
6185f870 PM |
37 | const struct nf_conntrack_tuple *tuple, |
38 | enum nf_nat_manip_type maniptype) | |
39 | { | |
6185f870 | 40 | struct udphdr *hdr; |
6185f870 PM |
41 | __be16 *portptr, newport; |
42 | ||
43 | if (!skb_make_writable(skb, hdroff + sizeof(*hdr))) | |
f2ea825f | 44 | return false; |
6185f870 | 45 | |
6185f870 PM |
46 | hdr = (struct udphdr *)(skb->data + hdroff); |
47 | ||
cbc9f2f4 | 48 | if (maniptype == NF_NAT_MANIP_SRC) { |
c7232c99 | 49 | /* Get rid of source port */ |
6185f870 PM |
50 | newport = tuple->src.u.udp.port; |
51 | portptr = &hdr->source; | |
52 | } else { | |
c7232c99 | 53 | /* Get rid of dst port */ |
6185f870 PM |
54 | newport = tuple->dst.u.udp.port; |
55 | portptr = &hdr->dest; | |
56 | } | |
57 | ||
c7232c99 | 58 | l3proto->csum_update(skb, iphdroff, &hdr->check, tuple, maniptype); |
4b048d6d | 59 | inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, false); |
6185f870 PM |
60 | if (!hdr->check) |
61 | hdr->check = CSUM_MANGLED_0; | |
62 | ||
63 | *portptr = newport; | |
f2ea825f | 64 | return true; |
6185f870 PM |
65 | } |
66 | ||
c7232c99 PM |
67 | static const struct nf_nat_l4proto nf_nat_l4proto_udplite = { |
68 | .l4proto = IPPROTO_UDPLITE, | |
6185f870 | 69 | .manip_pkt = udplite_manip_pkt, |
c7232c99 | 70 | .in_range = nf_nat_l4proto_in_range, |
6185f870 | 71 | .unique_tuple = udplite_unique_tuple, |
24de3d37 | 72 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
c7232c99 | 73 | .nlattr_to_range = nf_nat_l4proto_nlattr_to_range, |
6185f870 PM |
74 | #endif |
75 | }; | |
76 | ||
77 | static int __init nf_nat_proto_udplite_init(void) | |
78 | { | |
c7232c99 PM |
79 | int err; |
80 | ||
81 | err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_udplite); | |
82 | if (err < 0) | |
83 | goto err1; | |
84 | err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_udplite); | |
85 | if (err < 0) | |
86 | goto err2; | |
87 | return 0; | |
88 | ||
89 | err2: | |
90 | nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite); | |
91 | err1: | |
92 | return err; | |
6185f870 PM |
93 | } |
94 | ||
95 | static void __exit nf_nat_proto_udplite_fini(void) | |
96 | { | |
c7232c99 PM |
97 | nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_udplite); |
98 | nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite); | |
6185f870 PM |
99 | } |
100 | ||
101 | module_init(nf_nat_proto_udplite_init); | |
102 | module_exit(nf_nat_proto_udplite_fini); | |
103 | ||
104 | MODULE_LICENSE("GPL"); | |
105 | MODULE_DESCRIPTION("UDP-Lite NAT protocol helper"); | |
106 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |