1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2003+ Evgeniy Polyakov <zbr@ioremap.net>
4 */
5#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6#include <linux/module.h>
7#include <linux/kernel.h>
8
9#include <linux/capability.h>
10#include <linux/if.h>
11#include <linux/inetdevice.h>
12#include <linux/ip.h>
13#include <linux/list.h>
14#include <linux/rculist.h>
15#include <linux/skbuff.h>
16#include <linux/slab.h>
17#include <linux/tcp.h>
18
19#include <net/ip.h>
20#include <net/tcp.h>
21
22#include <linux/netfilter/nfnetlink.h>
23#include <linux/netfilter/x_tables.h>
24#include <net/netfilter/nf_log.h>
25#include <linux/netfilter/xt_osf.h>
26
27static bool
28xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p)
29{
30	return nf_osf_match(skb, xt_family(p), xt_hooknum(p), xt_in(p),
31			    xt_out(p), p->matchinfo, xt_net(p), nf_osf_fingers);
32}
33
34static struct xt_match xt_osf_match = {
35	.name 		= "osf",
36	.revision	= 0,
37	.family		= NFPROTO_IPV4,
38	.proto		= IPPROTO_TCP,
39	.hooks      	= (1 << NF_INET_LOCAL_IN) |
40				(1 << NF_INET_PRE_ROUTING) |
41				(1 << NF_INET_FORWARD),
42	.match 		= xt_osf_match_packet,
43	.matchsize	= sizeof(struct xt_osf_info),
44	.me		= THIS_MODULE,
45};
46
47static int __init xt_osf_init(void)
48{
49	int err;
50
51	err = xt_register_match(&xt_osf_match);
52	if (err) {
53		pr_err("Failed to register OS fingerprint "
54		       "matching module (%d)\n", err);
55		return err;
56	}
57
58	return 0;
59}
60
61static void __exit xt_osf_fini(void)
62{
63	xt_unregister_match(&xt_osf_match);
64}
65
66module_init(xt_osf_init);
67module_exit(xt_osf_fini);
68
69MODULE_LICENSE("GPL");
70MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
71MODULE_DESCRIPTION("Passive OS fingerprint matching.");
72MODULE_ALIAS("ipt_osf");
73MODULE_ALIAS("ip6t_osf");
74