1/* 2 * iptables module to match inet_addr_type() of an ip. 3 * 4 * Copyright (c) 2004 Patrick McHardy <kaber@trash.net> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11#include <linux/kernel.h> 12#include <linux/module.h> 13#include <linux/skbuff.h> 14#include <linux/netdevice.h> 15#include <linux/ip.h> 16#include <net/route.h> 17 18#include <linux/netfilter_ipv4/ipt_addrtype.h> 19#include <linux/netfilter/x_tables.h> 20 21MODULE_LICENSE("GPL"); 22MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 23MODULE_DESCRIPTION("iptables addrtype match"); 24 25static inline int match_type(__be32 addr, u_int16_t mask) 26{ 27 return !!(mask & (1 << inet_addr_type(addr))); 28} 29 30static int match(const struct sk_buff *skb, 31 const struct net_device *in, const struct net_device *out, 32 const struct xt_match *match, const void *matchinfo, 33 int offset, unsigned int protoff, int *hotdrop) 34{ 35 const struct ipt_addrtype_info *info = matchinfo; 36 const struct iphdr *iph = ip_hdr(skb); 37 int ret = 1; 38 39 if (info->source) 40 ret &= match_type(iph->saddr, info->source)^info->invert_source; 41 if (info->dest) 42 ret &= match_type(iph->daddr, info->dest)^info->invert_dest; 43 44 return ret; 45} 46 47static struct xt_match addrtype_match = { 48 .name = "addrtype", 49 .family = AF_INET, 50 .match = match, 51 .matchsize = sizeof(struct ipt_addrtype_info), 52 .me = THIS_MODULE 53}; 54 55static int __init ipt_addrtype_init(void) 56{ 57 return xt_register_match(&addrtype_match); 58} 59 60static void __exit ipt_addrtype_fini(void) 61{ 62 xt_unregister_match(&addrtype_match); 63} 64 65module_init(ipt_addrtype_init); 66module_exit(ipt_addrtype_fini); 67