Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 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> |
| 12 | #include <linux/udp.h> |
| 13 | |
| 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> |
| 19 | |
| 20 | static u16 udplite_port_rover; |
| 21 | |
| 22 | static void |
| 23 | udplite_unique_tuple(const struct nf_nat_l3proto *l3proto, |
| 24 | struct nf_conntrack_tuple *tuple, |
| 25 | const struct nf_nat_range *range, |
| 26 | enum nf_nat_manip_type maniptype, |
| 27 | const struct nf_conn *ct) |
| 28 | { |
| 29 | nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct, |
| 30 | &udplite_port_rover); |
| 31 | } |
| 32 | |
| 33 | static bool |
| 34 | udplite_manip_pkt(struct sk_buff *skb, |
| 35 | const struct nf_nat_l3proto *l3proto, |
| 36 | unsigned int iphdroff, unsigned int hdroff, |
| 37 | const struct nf_conntrack_tuple *tuple, |
| 38 | enum nf_nat_manip_type maniptype) |
| 39 | { |
| 40 | struct udphdr *hdr; |
| 41 | __be16 *portptr, newport; |
| 42 | |
| 43 | if (!skb_make_writable(skb, hdroff + sizeof(*hdr))) |
| 44 | return false; |
| 45 | |
| 46 | hdr = (struct udphdr *)(skb->data + hdroff); |
| 47 | |
| 48 | if (maniptype == NF_NAT_MANIP_SRC) { |
| 49 | /* Get rid of source port */ |
| 50 | newport = tuple->src.u.udp.port; |
| 51 | portptr = &hdr->source; |
| 52 | } else { |
| 53 | /* Get rid of dst port */ |
| 54 | newport = tuple->dst.u.udp.port; |
| 55 | portptr = &hdr->dest; |
| 56 | } |
| 57 | |
| 58 | l3proto->csum_update(skb, iphdroff, &hdr->check, tuple, maniptype); |
Tom Herbert | 4b048d6 | 2015-08-17 13:42:25 -0700 | [diff] [blame] | 59 | inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, false); |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 60 | if (!hdr->check) |
| 61 | hdr->check = CSUM_MANGLED_0; |
| 62 | |
| 63 | *portptr = newport; |
| 64 | return true; |
| 65 | } |
| 66 | |
| 67 | static const struct nf_nat_l4proto nf_nat_l4proto_udplite = { |
| 68 | .l4proto = IPPROTO_UDPLITE, |
| 69 | .manip_pkt = udplite_manip_pkt, |
| 70 | .in_range = nf_nat_l4proto_in_range, |
| 71 | .unique_tuple = udplite_unique_tuple, |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 72 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
Patrick McHardy | c7232c9 | 2012-08-26 19:14:06 +0200 | [diff] [blame] | 73 | .nlattr_to_range = nf_nat_l4proto_nlattr_to_range, |
| 74 | #endif |
| 75 | }; |
| 76 | |
| 77 | static int __init nf_nat_proto_udplite_init(void) |
| 78 | { |
| 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; |
| 93 | } |
| 94 | |
| 95 | static void __exit nf_nat_proto_udplite_fini(void) |
| 96 | { |
| 97 | nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_udplite); |
| 98 | nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite); |
| 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>"); |