net/netfilter/xt_osf.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Copyright (c) 2003+ Evgeniy Polyakov <zbr@ioremap.net>
0004  */
0005 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0006 #include <linux/module.h>
0007 #include <linux/kernel.h>
0008
0009 #include <linux/capability.h>
0010 #include <linux/if.h>
0011 #include <linux/inetdevice.h>
0012 #include <linux/ip.h>
0013 #include <linux/list.h>
0014 #include <linux/rculist.h>
0015 #include <linux/skbuff.h>
0016 #include <linux/slab.h>
0017 #include <linux/tcp.h>
0018
0019 #include <net/ip.h>
0020 #include <net/tcp.h>
0021
0022 #include <linux/netfilter/nfnetlink.h>
0023 #include <linux/netfilter/x_tables.h>
0024 #include <net/netfilter/nf_log.h>
0025 #include <linux/netfilter/xt_osf.h>
0026
0027 static bool
0028 xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p)
0029 {
0030     return nf_osf_match(skb, xt_family(p), xt_hooknum(p), xt_in(p),
0031                 xt_out(p), p->matchinfo, xt_net(p), nf_osf_fingers);
0032 }
0033
0034 static struct xt_match xt_osf_match = {
0035     .name       = "osf",
0036     .revision   = 0,
0037     .family     = NFPROTO_IPV4,
0038     .proto      = IPPROTO_TCP,
0039     .hooks          = (1 << NF_INET_LOCAL_IN) |
0040                 (1 << NF_INET_PRE_ROUTING) |
0041                 (1 << NF_INET_FORWARD),
0042     .match      = xt_osf_match_packet,
0043     .matchsize  = sizeof(struct xt_osf_info),
0044     .me     = THIS_MODULE,
0045 };
0046
0047 static int __init xt_osf_init(void)
0048 {
0049     int err;
0050
0051     err = xt_register_match(&xt_osf_match);
0052     if (err) {
0053         pr_err("Failed to register OS fingerprint "
0054                "matching module (%d)\n", err);
0055         return err;
0056     }
0057
0058     return 0;
0059 }
0060
0061 static void __exit xt_osf_fini(void)
0062 {
0063     xt_unregister_match(&xt_osf_match);
0064 }
0065
0066 module_init(xt_osf_init);
0067 module_exit(xt_osf_fini);
0068
0069 MODULE_LICENSE("GPL");
0070 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
0071 MODULE_DESCRIPTION("Passive OS fingerprint matching.");
0072 MODULE_ALIAS("ipt_osf");
0073 MODULE_ALIAS("ip6t_osf");
0074 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_OSF);