2 * NetBIOS name service broadcast connection tracking helper
4 * (c) 2005 Patrick McHardy <kaber@trash.net>
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.
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.
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
23 #include <net/netfilter/nf_conntrack.h>
24 #include <net/netfilter/nf_conntrack_helper.h>
25 #include <net/netfilter/nf_conntrack_expect.h>
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");
33 MODULE_ALIAS_NFCT_HELPER("netbios_ns");
35 static unsigned int timeout __read_mostly
= 3;
36 module_param(timeout
, uint
, S_IRUSR
);
37 MODULE_PARM_DESC(timeout
, "timeout for master connection/replies in seconds");
39 static struct nf_conntrack_expect_policy exp_policy
= {
43 static int netbios_ns_help(struct sk_buff
*skb
, unsigned int protoff
,
44 struct nf_conn
*ct
, enum ip_conntrack_info ctinfo
)
46 return nf_conntrack_broadcast_help(skb
, protoff
, ct
, ctinfo
, timeout
);
49 static struct nf_conntrack_helper helper __read_mostly
= {
51 .tuple
.src
.l3num
= NFPROTO_IPV4
,
52 .tuple
.src
.u
.udp
.port
= cpu_to_be16(NMBD_PORT
),
53 .tuple
.dst
.protonum
= IPPROTO_UDP
,
55 .help
= netbios_ns_help
,
56 .expect_policy
= &exp_policy
,
59 static int __init
nf_conntrack_netbios_ns_init(void)
61 exp_policy
.timeout
= timeout
;
62 return nf_conntrack_helper_register(&helper
);
65 static void __exit
nf_conntrack_netbios_ns_fini(void)
67 nf_conntrack_helper_unregister(&helper
);
70 module_init(nf_conntrack_netbios_ns_init
);
71 module_exit(nf_conntrack_netbios_ns_fini
);