| /* |
| * iptables module to match inet_addr_type() of an ip. |
| * |
| * Copyright (c) 2004 Patrick McHardy <kaber@trash.net> |
| * (C) 2007 Laszlo Attila Toth <panther@balabit.hu> |
| * |
| * 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/x_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| MODULE_DESCRIPTION("Xtables: address type match for IPv4"); |
| |
| static inline bool match_type(struct net *net, const struct net_device *dev, |
| __be32 addr, u_int16_t mask) |
| { |
| return !!(mask & (1 << inet_dev_addr_type(net, dev, addr))); |
| } |
| |
| static bool |
| addrtype_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par) |
| { |
| struct net *net = dev_net(par->in ? par->in : par->out); |
| const struct ipt_addrtype_info *info = par->matchinfo; |
| const struct iphdr *iph = ip_hdr(skb); |
| bool ret = true; |
| |
| if (info->source) |
| ret &= match_type(net, NULL, iph->saddr, info->source) ^ |
| info->invert_source; |
| if (info->dest) |
| ret &= match_type(net, NULL, iph->daddr, info->dest) ^ |
| info->invert_dest; |
| |
| return ret; |
| } |
| |
| static bool |
| addrtype_mt_v1(const struct sk_buff *skb, const struct xt_match_param *par) |
| { |
| struct net *net = dev_net(par->in ? par->in : par->out); |
| const struct ipt_addrtype_info_v1 *info = par->matchinfo; |
| const struct iphdr *iph = ip_hdr(skb); |
| const struct net_device *dev = NULL; |
| bool ret = true; |
| |
| if (info->flags & IPT_ADDRTYPE_LIMIT_IFACE_IN) |
| dev = par->in; |
| else if (info->flags & IPT_ADDRTYPE_LIMIT_IFACE_OUT) |
| dev = par->out; |
| |
| if (info->source) |
| ret &= match_type(net, dev, iph->saddr, info->source) ^ |
| (info->flags & IPT_ADDRTYPE_INVERT_SOURCE); |
| if (ret && info->dest) |
| ret &= match_type(net, dev, iph->daddr, info->dest) ^ |
| !!(info->flags & IPT_ADDRTYPE_INVERT_DEST); |
| return ret; |
| } |
| |
| static bool addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par) |
| { |
| struct ipt_addrtype_info_v1 *info = par->matchinfo; |
| |
| if (info->flags & IPT_ADDRTYPE_LIMIT_IFACE_IN && |
| info->flags & IPT_ADDRTYPE_LIMIT_IFACE_OUT) { |
| printk(KERN_ERR "ipt_addrtype: both incoming and outgoing " |
| "interface limitation cannot be selected\n"); |
| return false; |
| } |
| |
| if (par->hook_mask & ((1 << NF_INET_PRE_ROUTING) | |
| (1 << NF_INET_LOCAL_IN)) && |
| info->flags & IPT_ADDRTYPE_LIMIT_IFACE_OUT) { |
| printk(KERN_ERR "ipt_addrtype: output interface limitation " |
| "not valid in PRE_ROUTING and INPUT\n"); |
| return false; |
| } |
| |
| if (par->hook_mask & ((1 << NF_INET_POST_ROUTING) | |
| (1 << NF_INET_LOCAL_OUT)) && |
| info->flags & IPT_ADDRTYPE_LIMIT_IFACE_IN) { |
| printk(KERN_ERR "ipt_addrtype: input interface limitation " |
| "not valid in POST_ROUTING and OUTPUT\n"); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static struct xt_match addrtype_mt_reg[] __read_mostly = { |
| { |
| .name = "addrtype", |
| .family = NFPROTO_IPV4, |
| .match = addrtype_mt_v0, |
| .matchsize = sizeof(struct ipt_addrtype_info), |
| .me = THIS_MODULE |
| }, |
| { |
| .name = "addrtype", |
| .family = NFPROTO_IPV4, |
| .revision = 1, |
| .match = addrtype_mt_v1, |
| .checkentry = addrtype_mt_checkentry_v1, |
| .matchsize = sizeof(struct ipt_addrtype_info_v1), |
| .me = THIS_MODULE |
| } |
| }; |
| |
| static int __init addrtype_mt_init(void) |
| { |
| return xt_register_matches(addrtype_mt_reg, |
| ARRAY_SIZE(addrtype_mt_reg)); |
| } |
| |
| static void __exit addrtype_mt_exit(void) |
| { |
| xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg)); |
| } |
| |
| module_init(addrtype_mt_init); |
| module_exit(addrtype_mt_exit); |