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/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 IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
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
));
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 IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
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 IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
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
);