2 * iptables module to match inet_addr_type() of an ip.
4 * Copyright (c) 2004 Patrick McHardy <kaber@trash.net>
5 * (C) 2007 Laszlo Attila Toth <panther@balabit.hu>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/netdevice.h>
17 #include <net/route.h>
19 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
21 #include <net/ip6_route.h>
22 #include <net/ip6_fib.h>
25 #include <linux/netfilter/xt_addrtype.h>
26 #include <linux/netfilter/x_tables.h>
28 MODULE_LICENSE("GPL");
29 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
30 MODULE_DESCRIPTION("Xtables: address type match");
31 MODULE_ALIAS("ipt_addrtype");
32 MODULE_ALIAS("ip6t_addrtype");
34 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
35 static u32 match_lookup_rt6(struct net *net, const struct net_device *dev,
36 const struct in6_addr *addr)
38 const struct nf_afinfo *afinfo;
44 memset(&flow, 0, sizeof(flow));
45 ipv6_addr_copy(&flow.daddr, addr);
47 flow.flowi6_oif = dev->ifindex;
51 afinfo = nf_get_afinfo(NFPROTO_IPV6);
53 route_err = afinfo->route(net, (struct dst_entry **)&rt,
54 flowi6_to_flowi(&flow), !!dev);
61 return XT_ADDRTYPE_UNREACHABLE;
63 if (rt->rt6i_flags & RTF_REJECT)
64 ret = XT_ADDRTYPE_UNREACHABLE;
68 if (rt->rt6i_flags & RTF_LOCAL)
69 ret |= XT_ADDRTYPE_LOCAL;
70 if (rt->rt6i_flags & RTF_ANYCAST)
71 ret |= XT_ADDRTYPE_ANYCAST;
74 dst_release(&rt->dst);
78 static bool match_type6(struct net *net, const struct net_device *dev,
79 const struct in6_addr *addr, u16 mask)
81 int addr_type = ipv6_addr_type(addr);
83 if ((mask & XT_ADDRTYPE_MULTICAST) &&
84 !(addr_type & IPV6_ADDR_MULTICAST))
86 if ((mask & XT_ADDRTYPE_UNICAST) && !(addr_type & IPV6_ADDR_UNICAST))
88 if ((mask & XT_ADDRTYPE_UNSPEC) && addr_type != IPV6_ADDR_ANY)
91 if ((XT_ADDRTYPE_LOCAL | XT_ADDRTYPE_ANYCAST |
92 XT_ADDRTYPE_UNREACHABLE) & mask)
93 return !!(mask & match_lookup_rt6(net, dev, addr));
98 addrtype_mt6(struct net *net, const struct net_device *dev,
99 const struct sk_buff *skb, const struct xt_addrtype_info_v1 *info)
101 const struct ipv6hdr *iph = ipv6_hdr(skb);
105 ret &= match_type6(net, dev, &iph->saddr, info->source) ^
106 (info->flags & XT_ADDRTYPE_INVERT_SOURCE);
107 if (ret && info->dest)
108 ret &= match_type6(net, dev, &iph->daddr, info->dest) ^
109 !!(info->flags & XT_ADDRTYPE_INVERT_DEST);
114 static inline bool match_type(struct net *net, const struct net_device *dev,
115 __be32 addr, u_int16_t mask)
117 return !!(mask & (1 << inet_dev_addr_type(net, dev, addr)));
121 addrtype_mt_v0(const struct sk_buff *skb, struct xt_action_param *par)
123 struct net *net = dev_net(par->in ? par->in : par->out);
124 const struct xt_addrtype_info *info = par->matchinfo;
125 const struct iphdr *iph = ip_hdr(skb);
129 ret &= match_type(net, NULL, iph->saddr, info->source) ^
132 ret &= match_type(net, NULL, iph->daddr, info->dest) ^
139 addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
141 struct net *net = dev_net(par->in ? par->in : par->out);
142 const struct xt_addrtype_info_v1 *info = par->matchinfo;
143 const struct iphdr *iph;
144 const struct net_device *dev = NULL;
147 if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN)
149 else if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT)
152 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
153 if (par->family == NFPROTO_IPV6)
154 return addrtype_mt6(net, dev, skb, info);
158 ret &= match_type(net, dev, iph->saddr, info->source) ^
159 (info->flags & XT_ADDRTYPE_INVERT_SOURCE);
160 if (ret && info->dest)
161 ret &= match_type(net, dev, iph->daddr, info->dest) ^
162 !!(info->flags & XT_ADDRTYPE_INVERT_DEST);
166 static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par)
168 struct xt_addrtype_info_v1 *info = par->matchinfo;
170 if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN &&
171 info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) {
172 pr_info("both incoming and outgoing "
173 "interface limitation cannot be selected\n");
177 if (par->hook_mask & ((1 << NF_INET_PRE_ROUTING) |
178 (1 << NF_INET_LOCAL_IN)) &&
179 info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) {
180 pr_info("output interface limitation "
181 "not valid in PREROUTING and INPUT\n");
185 if (par->hook_mask & ((1 << NF_INET_POST_ROUTING) |
186 (1 << NF_INET_LOCAL_OUT)) &&
187 info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN) {
188 pr_info("input interface limitation "
189 "not valid in POSTROUTING and OUTPUT\n");
193 #if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
194 if (par->family == NFPROTO_IPV6) {
195 if ((info->source | info->dest) & XT_ADDRTYPE_BLACKHOLE) {
196 pr_err("ipv6 BLACKHOLE matching not supported\n");
199 if ((info->source | info->dest) >= XT_ADDRTYPE_PROHIBIT) {
200 pr_err("ipv6 PROHIBT (THROW, NAT ..) matching not supported\n");
203 if ((info->source | info->dest) & XT_ADDRTYPE_BROADCAST) {
204 pr_err("ipv6 does not support BROADCAST matching\n");
212 static struct xt_match addrtype_mt_reg[] __read_mostly = {
215 .family = NFPROTO_IPV4,
216 .match = addrtype_mt_v0,
217 .matchsize = sizeof(struct xt_addrtype_info),
222 .family = NFPROTO_UNSPEC,
224 .match = addrtype_mt_v1,
225 .checkentry = addrtype_mt_checkentry_v1,
226 .matchsize = sizeof(struct xt_addrtype_info_v1),
231 static int __init addrtype_mt_init(void)
233 return xt_register_matches(addrtype_mt_reg,
234 ARRAY_SIZE(addrtype_mt_reg));
237 static void __exit addrtype_mt_exit(void)
239 xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg));
242 module_init(addrtype_mt_init);
243 module_exit(addrtype_mt_exit);