[mirror_ubuntu-jammy-kernel.git] / net / netfilter / nf_conntrack_netbios_ns.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *      NetBIOS name service broadcast connection tracking helper
 *
 *      (c) 2005 Patrick McHardy <kaber@trash.net>
 */
/*
 *      This helper tracks locally originating NetBIOS name service
 *      requests by issuing permanent expectations (valid until
 *      timing out) matching all reply connections from the
 *      destination network. The only NetBIOS specific thing is
 *      actually the port number.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/in.h>

#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_expect.h>

#define NMBD_PORT	137

MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("NetBIOS name service broadcast connection tracking helper");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ip_conntrack_netbios_ns");
MODULE_ALIAS_NFCT_HELPER("netbios_ns");

static unsigned int timeout __read_mostly = 3;
module_param(timeout, uint, 0400);
MODULE_PARM_DESC(timeout, "timeout for master connection/replies in seconds");

static struct nf_conntrack_expect_policy exp_policy = {
	.max_expected	= 1,
};

static int netbios_ns_help(struct sk_buff *skb, unsigned int protoff,
			   struct nf_conn *ct,
			   enum ip_conntrack_info ctinfo)
{
	return nf_conntrack_broadcast_help(skb, ct, ctinfo, timeout);
}

static struct nf_conntrack_helper helper __read_mostly = {
	.name			= "netbios-ns",
	.tuple.src.l3num	= NFPROTO_IPV4,
	.tuple.src.u.udp.port	= cpu_to_be16(NMBD_PORT),
	.tuple.dst.protonum	= IPPROTO_UDP,
	.me			= THIS_MODULE,
	.help			= netbios_ns_help,
	.expect_policy		= &exp_policy,
};

static int __init nf_conntrack_netbios_ns_init(void)
{
	NF_CT_HELPER_BUILD_BUG_ON(0);

	exp_policy.timeout = timeout;
	return nf_conntrack_helper_register(&helper);
}

static void __exit nf_conntrack_netbios_ns_fini(void)
{
	nf_conntrack_helper_unregister(&helper);
}

module_init(nf_conntrack_netbios_ns_init);
module_exit(nf_conntrack_netbios_ns_fini);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
92703eee PM	2	/*
	3	* NetBIOS name service broadcast connection tracking helper
	4	*
	5	* (c) 2005 Patrick McHardy <kaber@trash.net>
92703eee PM	6	*/
	7	/*
	8	* This helper tracks locally originating NetBIOS name service
	9	* requests by issuing permanent expectations (valid until
	10	* timing out) matching all reply connections from the
	11	* destination network. The only NetBIOS specific thing is
	12	* actually the port number.
	13	*/
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
	16	#include <linux/init.h>
92703eee	17	#include <linux/in.h>
92703eee PM	18
	19	#include <net/netfilter/nf_conntrack.h>
	20	#include <net/netfilter/nf_conntrack_helper.h>
	21	#include <net/netfilter/nf_conntrack_expect.h>
	22
	23	#define NMBD_PORT 137
	24
	25	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	26	MODULE_DESCRIPTION("NetBIOS name service broadcast connection tracking helper");
	27	MODULE_LICENSE("GPL");
	28	MODULE_ALIAS("ip_conntrack_netbios_ns");
4dc06f96	29	MODULE_ALIAS_NFCT_HELPER("netbios_ns");
92703eee PM	30
92703eee PM	31	static unsigned int timeout __read_mostly = 3;
d6444062	32	module_param(timeout, uint, 0400);
92703eee PM	33	MODULE_PARM_DESC(timeout, "timeout for master connection/replies in seconds");
92703eee PM	34
6002f266 PM	35	static struct nf_conntrack_expect_policy exp_policy = {
	36	.max_expected = 1,
	37	};
	38
93557f53	39	static int netbios_ns_help(struct sk_buff *skb, unsigned int protoff,
433029ec TY	40	struct nf_conn *ct,
433029ec TY	41	enum ip_conntrack_info ctinfo)
93557f53	42	{
433029ec	43	return nf_conntrack_broadcast_help(skb, ct, ctinfo, timeout);
93557f53 JO	44	}
93557f53 JO	45
92703eee PM	46	static struct nf_conntrack_helper helper __read_mostly = {
92703eee PM	47	.name = "netbios-ns",
93557f53	48	.tuple.src.l3num = NFPROTO_IPV4,
09640e63	49	.tuple.src.u.udp.port = cpu_to_be16(NMBD_PORT),
92703eee	50	.tuple.dst.protonum = IPPROTO_UDP,
92703eee	51	.me = THIS_MODULE,
93557f53	52	.help = netbios_ns_help,
6002f266	53	.expect_policy = &exp_policy,
92703eee PM	54	};
	55
	56	static int __init nf_conntrack_netbios_ns_init(void)
	57	{
dcf67740 FW	58	NF_CT_HELPER_BUILD_BUG_ON(0);
dcf67740 FW	59
6002f266	60	exp_policy.timeout = timeout;
92703eee PM	61	return nf_conntrack_helper_register(&helper);
	62	}
	63
	64	static void __exit nf_conntrack_netbios_ns_fini(void)
	65	{
	66	nf_conntrack_helper_unregister(&helper);
	67	}
	68
	69	module_init(nf_conntrack_netbios_ns_init);
	70	module_exit(nf_conntrack_netbios_ns_fini);