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, family: xt_family(par: p), hooknum: xt_hooknum(par: p), in: xt_in(par: p),
31 out: xt_out(par: p), info: p->matchinfo, net: xt_net(par: 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(target: &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(target: &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

source code of linux/net/netfilter/xt_osf.c