net/netfilter/xt_osf.c

   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
  27 static bool
  28 xt_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
  34 static 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
  47 static 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
  61 static void __exit xt_osf_fini(void)
  62 {
  63         xt_unregister_match(&xt_osf_match);
  64 }
  65
  66 module_init(xt_osf_init);
  67 module_exit(xt_osf_fini);
  68
  69 MODULE_LICENSE("GPL");
  70 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
  71 MODULE_DESCRIPTION("Passive OS fingerprint matching.");
  72 MODULE_ALIAS("ipt_osf");
  73 MODULE_ALIAS("ip6t_osf");
  74 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_OSF);