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
);