Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 1 | /* |
| 2 | * NetBIOS name service broadcast connection tracking helper |
| 3 | * |
| 4 | * (c) 2005 Patrick McHardy <kaber@trash.net> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| 11 | /* |
| 12 | * This helper tracks locally originating NetBIOS name service |
| 13 | * requests by issuing permanent expectations (valid until |
| 14 | * timing out) matching all reply connections from the |
| 15 | * destination network. The only NetBIOS specific thing is |
| 16 | * actually the port number. |
| 17 | */ |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/init.h> |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 21 | #include <linux/in.h> |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 22 | |
| 23 | #include <net/netfilter/nf_conntrack.h> |
| 24 | #include <net/netfilter/nf_conntrack_helper.h> |
| 25 | #include <net/netfilter/nf_conntrack_expect.h> |
| 26 | |
| 27 | #define NMBD_PORT 137 |
| 28 | |
| 29 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 30 | MODULE_DESCRIPTION("NetBIOS name service broadcast connection tracking helper"); |
| 31 | MODULE_LICENSE("GPL"); |
| 32 | MODULE_ALIAS("ip_conntrack_netbios_ns"); |
Pablo Neira Ayuso | 4dc06f9 | 2008-11-17 16:01:42 +0100 | [diff] [blame] | 33 | MODULE_ALIAS_NFCT_HELPER("netbios_ns"); |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 34 | |
| 35 | static unsigned int timeout __read_mostly = 3; |
Jiri Olsa | 93557f5 | 2011-01-18 18:12:24 +0100 | [diff] [blame] | 36 | module_param(timeout, uint, S_IRUSR); |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 37 | MODULE_PARM_DESC(timeout, "timeout for master connection/replies in seconds"); |
| 38 | |
Patrick McHardy | 6002f26 | 2008-03-25 20:09:15 -0700 | [diff] [blame] | 39 | static struct nf_conntrack_expect_policy exp_policy = { |
| 40 | .max_expected = 1, |
| 41 | }; |
| 42 | |
Jiri Olsa | 93557f5 | 2011-01-18 18:12:24 +0100 | [diff] [blame] | 43 | static int netbios_ns_help(struct sk_buff *skb, unsigned int protoff, |
| 44 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
| 45 | { |
| 46 | return nf_conntrack_broadcast_help(skb, protoff, ct, ctinfo, timeout); |
| 47 | } |
| 48 | |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 49 | static struct nf_conntrack_helper helper __read_mostly = { |
| 50 | .name = "netbios-ns", |
Jiri Olsa | 93557f5 | 2011-01-18 18:12:24 +0100 | [diff] [blame] | 51 | .tuple.src.l3num = NFPROTO_IPV4, |
Harvey Harrison | 09640e6 | 2009-02-01 00:45:17 -0800 | [diff] [blame] | 52 | .tuple.src.u.udp.port = cpu_to_be16(NMBD_PORT), |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 53 | .tuple.dst.protonum = IPPROTO_UDP, |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 54 | .me = THIS_MODULE, |
Jiri Olsa | 93557f5 | 2011-01-18 18:12:24 +0100 | [diff] [blame] | 55 | .help = netbios_ns_help, |
Patrick McHardy | 6002f26 | 2008-03-25 20:09:15 -0700 | [diff] [blame] | 56 | .expect_policy = &exp_policy, |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 57 | }; |
| 58 | |
| 59 | static int __init nf_conntrack_netbios_ns_init(void) |
| 60 | { |
Patrick McHardy | 6002f26 | 2008-03-25 20:09:15 -0700 | [diff] [blame] | 61 | exp_policy.timeout = timeout; |
Patrick McHardy | 92703ee | 2006-12-02 22:09:24 -0800 | [diff] [blame] | 62 | return nf_conntrack_helper_register(&helper); |
| 63 | } |
| 64 | |
| 65 | static void __exit nf_conntrack_netbios_ns_fini(void) |
| 66 | { |
| 67 | nf_conntrack_helper_unregister(&helper); |
| 68 | } |
| 69 | |
| 70 | module_init(nf_conntrack_netbios_ns_init); |
| 71 | module_exit(nf_conntrack_netbios_ns_fini); |