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