| /* |
| * iptables module to match inet_addr_type() of an ip. |
| * |
| * Copyright (c) 2004 Patrick McHardy <kaber@trash.net> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/netdevice.h> |
| #include <linux/ip.h> |
| #include <net/route.h> |
| |
| #include <linux/netfilter_ipv4/ipt_addrtype.h> |
| #include <linux/netfilter_ipv4/ip_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| MODULE_DESCRIPTION("iptables addrtype match"); |
| |
| static inline int match_type(__be32 addr, u_int16_t mask) |
| { |
| return !!(mask & (1 << inet_addr_type(addr))); |
| } |
| |
| static int match(const struct sk_buff *skb, |
| const struct net_device *in, const struct net_device *out, |
| const struct xt_match *match, const void *matchinfo, |
| int offset, unsigned int protoff, int *hotdrop) |
| { |
| const struct ipt_addrtype_info *info = matchinfo; |
| const struct iphdr *iph = skb->nh.iph; |
| int ret = 1; |
| |
| if (info->source) |
| ret &= match_type(iph->saddr, info->source)^info->invert_source; |
| if (info->dest) |
| ret &= match_type(iph->daddr, info->dest)^info->invert_dest; |
| |
| return ret; |
| } |
| |
| static struct ipt_match addrtype_match = { |
| .name = "addrtype", |
| .match = match, |
| .matchsize = sizeof(struct ipt_addrtype_info), |
| .me = THIS_MODULE |
| }; |
| |
| static int __init ipt_addrtype_init(void) |
| { |
| return ipt_register_match(&addrtype_match); |
| } |
| |
| static void __exit ipt_addrtype_fini(void) |
| { |
| ipt_unregister_match(&addrtype_match); |
| } |
| |
| module_init(ipt_addrtype_init); |
| module_exit(ipt_addrtype_fini); |