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 IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
21 #include <net/ip6_route.h>
22 #include <net/ip6_fib.h>
25 #include <linux/netfilter_ipv6.h>
26 #include <linux/netfilter/xt_addrtype.h>
27 #include <linux/netfilter/x_tables.h>
29 MODULE_LICENSE("GPL");
30 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
31 MODULE_DESCRIPTION("Xtables: address type match");
32 MODULE_ALIAS("ipt_addrtype");
33 MODULE_ALIAS("ip6t_addrtype");
35 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
36 static u32 match_lookup_rt6(struct net *net, const struct net_device *dev,
37 const struct in6_addr *addr, u16 mask)
39 const struct nf_afinfo *afinfo;
45 memset(&flow, 0, sizeof(flow));
48 flow.flowi6_oif = dev->ifindex;
50 afinfo = nf_get_afinfo(NFPROTO_IPV6);
52 const struct nf_ipv6_ops *v6ops;
54 if (dev && (mask & XT_ADDRTYPE_LOCAL)) {
55 v6ops = nf_get_ipv6_ops();
56 if (v6ops && v6ops->chk_addr(net, addr, dev, true))
57 ret = XT_ADDRTYPE_LOCAL;
59 route_err = afinfo->route(net, (struct dst_entry **)&rt,
60 flowi6_to_flowi(&flow), false);
66 return XT_ADDRTYPE_UNREACHABLE;
68 if (rt->rt6i_flags & RTF_REJECT)
69 ret = XT_ADDRTYPE_UNREACHABLE;
71 if (dev == NULL && rt->rt6i_flags & RTF_LOCAL)
72 ret |= XT_ADDRTYPE_LOCAL;
73 if (ipv6_anycast_destination((struct dst_entry *)rt, addr))
74 ret |= XT_ADDRTYPE_ANYCAST;
76 dst_release(&rt->dst);
80 static bool match_type6(struct net *net, const struct net_device *dev,
81 const struct in6_addr *addr, u16 mask)
83 int addr_type = ipv6_addr_type(addr);
85 if ((mask & XT_ADDRTYPE_MULTICAST) &&
86 !(addr_type & IPV6_ADDR_MULTICAST))
88 if ((mask & XT_ADDRTYPE_UNICAST) && !(addr_type & IPV6_ADDR_UNICAST))
90 if ((mask & XT_ADDRTYPE_UNSPEC) && addr_type != IPV6_ADDR_ANY)
93 if ((XT_ADDRTYPE_LOCAL | XT_ADDRTYPE_ANYCAST |
94 XT_ADDRTYPE_UNREACHABLE) & mask)
95 return !!(mask & match_lookup_rt6(net, dev, addr, mask));
100 addrtype_mt6(struct net *net, const struct net_device *dev,
101 const struct sk_buff *skb, const struct xt_addrtype_info_v1 *info)
103 const struct ipv6hdr *iph = ipv6_hdr(skb);
107 ret &= match_type6(net, dev, &iph->saddr, info->source) ^
108 (info->flags & XT_ADDRTYPE_INVERT_SOURCE);
109 if (ret && info->dest)
110 ret &= match_type6(net, dev, &iph->daddr, info->dest) ^
111 !!(info->flags & XT_ADDRTYPE_INVERT_DEST);
116 static inline bool match_type(struct net *net, const struct net_device *dev,
117 __be32 addr, u_int16_t mask)
119 return !!(mask & (1 << inet_dev_addr_type(net, dev, addr)));
123 addrtype_mt_v0(const struct sk_buff *skb, struct xt_action_param *par)
125 struct net *net = xt_net(par);
126 const struct xt_addrtype_info *info = par->matchinfo;
127 const struct iphdr *iph = ip_hdr(skb);
131 ret &= match_type(net, NULL, iph->saddr, info->source) ^
134 ret &= match_type(net, NULL, iph->daddr, info->dest) ^
141 addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
143 struct net *net = xt_net(par);
144 const struct xt_addrtype_info_v1 *info = par->matchinfo;
145 const struct iphdr *iph;
146 const struct net_device *dev = NULL;
149 if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN)
151 else if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT)
154 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
155 if (xt_family(par) == NFPROTO_IPV6)
156 return addrtype_mt6(net, dev, skb, info);
160 ret &= match_type(net, dev, iph->saddr, info->source) ^
161 (info->flags & XT_ADDRTYPE_INVERT_SOURCE);
162 if (ret && info->dest)
163 ret &= match_type(net, dev, iph->daddr, info->dest) ^
164 !!(info->flags & XT_ADDRTYPE_INVERT_DEST);
168 static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par)
170 struct xt_addrtype_info_v1 *info = par->matchinfo;
172 if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN &&
173 info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) {
174 pr_info("both incoming and outgoing "
175 "interface limitation cannot be selected\n");
179 if (par->hook_mask & ((1 << NF_INET_PRE_ROUTING) |
180 (1 << NF_INET_LOCAL_IN)) &&
181 info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) {
182 pr_info("output interface limitation "
183 "not valid in PREROUTING and INPUT\n");
187 if (par->hook_mask & ((1 << NF_INET_POST_ROUTING) |
188 (1 << NF_INET_LOCAL_OUT)) &&
189 info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN) {
190 pr_info("input interface limitation "
191 "not valid in POSTROUTING and OUTPUT\n");
195 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
196 if (par->family == NFPROTO_IPV6) {
197 if ((info->source | info->dest) & XT_ADDRTYPE_BLACKHOLE) {
198 pr_err("ipv6 BLACKHOLE matching not supported\n");
201 if ((info->source | info->dest) >= XT_ADDRTYPE_PROHIBIT) {
202 pr_err("ipv6 PROHIBIT (THROW, NAT ..) matching not supported\n");
205 if ((info->source | info->dest) & XT_ADDRTYPE_BROADCAST) {
206 pr_err("ipv6 does not support BROADCAST matching\n");
214 static struct xt_match addrtype_mt_reg[] __read_mostly = {
217 .family = NFPROTO_IPV4,
218 .match = addrtype_mt_v0,
219 .matchsize = sizeof(struct xt_addrtype_info),
224 .family = NFPROTO_UNSPEC,
226 .match = addrtype_mt_v1,
227 .checkentry = addrtype_mt_checkentry_v1,
228 .matchsize = sizeof(struct xt_addrtype_info_v1),
233 static int __init addrtype_mt_init(void)
235 return xt_register_matches(addrtype_mt_reg,
236 ARRAY_SIZE(addrtype_mt_reg));
239 static void __exit addrtype_mt_exit(void)
241 xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg));
244 module_init(addrtype_mt_init);
245 module_exit(addrtype_mt_exit);