1 // SPDX-License-Identifier: GPL-2.0-only
3 * iptables module to match inet_addr_type() of an ip.
5 * Copyright (c) 2004 Patrick McHardy <kaber@trash.net>
6 * (C) 2007 Laszlo Attila Toth <panther@balabit.hu>
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
12 #include <linux/netdevice.h>
14 #include <net/route.h>
16 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
18 #include <net/ip6_route.h>
19 #include <net/ip6_fib.h>
22 #include <linux/netfilter_ipv6.h>
23 #include <linux/netfilter/xt_addrtype.h>
24 #include <linux/netfilter/x_tables.h>
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
28 MODULE_DESCRIPTION("Xtables: address type match");
29 MODULE_ALIAS("ipt_addrtype");
30 MODULE_ALIAS("ip6t_addrtype");
32 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
33 static u32
match_lookup_rt6(struct net
*net
, const struct net_device
*dev
,
34 const struct in6_addr
*addr
, u16 mask
)
41 memset(&flow
, 0, sizeof(flow
));
44 flow
.flowi6_oif
= dev
->ifindex
;
46 if (dev
&& (mask
& XT_ADDRTYPE_LOCAL
)) {
47 if (nf_ipv6_chk_addr(net
, addr
, dev
, true))
48 ret
= XT_ADDRTYPE_LOCAL
;
51 route_err
= nf_ip6_route(net
, (struct dst_entry
**)&rt
,
52 flowi6_to_flowi(&flow
), false);
54 return XT_ADDRTYPE_UNREACHABLE
;
56 if (rt
->rt6i_flags
& RTF_REJECT
)
57 ret
= XT_ADDRTYPE_UNREACHABLE
;
59 if (dev
== NULL
&& rt
->rt6i_flags
& RTF_LOCAL
)
60 ret
|= XT_ADDRTYPE_LOCAL
;
61 if (ipv6_anycast_destination((struct dst_entry
*)rt
, addr
))
62 ret
|= XT_ADDRTYPE_ANYCAST
;
64 dst_release(&rt
->dst
);
68 static bool match_type6(struct net
*net
, const struct net_device
*dev
,
69 const struct in6_addr
*addr
, u16 mask
)
71 int addr_type
= ipv6_addr_type(addr
);
73 if ((mask
& XT_ADDRTYPE_MULTICAST
) &&
74 !(addr_type
& IPV6_ADDR_MULTICAST
))
76 if ((mask
& XT_ADDRTYPE_UNICAST
) && !(addr_type
& IPV6_ADDR_UNICAST
))
78 if ((mask
& XT_ADDRTYPE_UNSPEC
) && addr_type
!= IPV6_ADDR_ANY
)
81 if ((XT_ADDRTYPE_LOCAL
| XT_ADDRTYPE_ANYCAST
|
82 XT_ADDRTYPE_UNREACHABLE
) & mask
)
83 return !!(mask
& match_lookup_rt6(net
, dev
, addr
, mask
));
88 addrtype_mt6(struct net
*net
, const struct net_device
*dev
,
89 const struct sk_buff
*skb
, const struct xt_addrtype_info_v1
*info
)
91 const struct ipv6hdr
*iph
= ipv6_hdr(skb
);
95 ret
&= match_type6(net
, dev
, &iph
->saddr
, info
->source
) ^
96 (info
->flags
& XT_ADDRTYPE_INVERT_SOURCE
);
97 if (ret
&& info
->dest
)
98 ret
&= match_type6(net
, dev
, &iph
->daddr
, info
->dest
) ^
99 !!(info
->flags
& XT_ADDRTYPE_INVERT_DEST
);
104 static inline bool match_type(struct net
*net
, const struct net_device
*dev
,
105 __be32 addr
, u_int16_t mask
)
107 return !!(mask
& (1 << inet_dev_addr_type(net
, dev
, addr
)));
111 addrtype_mt_v0(const struct sk_buff
*skb
, struct xt_action_param
*par
)
113 struct net
*net
= xt_net(par
);
114 const struct xt_addrtype_info
*info
= par
->matchinfo
;
115 const struct iphdr
*iph
= ip_hdr(skb
);
119 ret
&= match_type(net
, NULL
, iph
->saddr
, info
->source
) ^
122 ret
&= match_type(net
, NULL
, iph
->daddr
, info
->dest
) ^
129 addrtype_mt_v1(const struct sk_buff
*skb
, struct xt_action_param
*par
)
131 struct net
*net
= xt_net(par
);
132 const struct xt_addrtype_info_v1
*info
= par
->matchinfo
;
133 const struct iphdr
*iph
;
134 const struct net_device
*dev
= NULL
;
137 if (info
->flags
& XT_ADDRTYPE_LIMIT_IFACE_IN
)
139 else if (info
->flags
& XT_ADDRTYPE_LIMIT_IFACE_OUT
)
142 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
143 if (xt_family(par
) == NFPROTO_IPV6
)
144 return addrtype_mt6(net
, dev
, skb
, info
);
148 ret
&= match_type(net
, dev
, iph
->saddr
, info
->source
) ^
149 (info
->flags
& XT_ADDRTYPE_INVERT_SOURCE
);
150 if (ret
&& info
->dest
)
151 ret
&= match_type(net
, dev
, iph
->daddr
, info
->dest
) ^
152 !!(info
->flags
& XT_ADDRTYPE_INVERT_DEST
);
156 static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param
*par
)
158 const char *errmsg
= "both incoming and outgoing interface limitation cannot be selected";
159 struct xt_addrtype_info_v1
*info
= par
->matchinfo
;
161 if (info
->flags
& XT_ADDRTYPE_LIMIT_IFACE_IN
&&
162 info
->flags
& XT_ADDRTYPE_LIMIT_IFACE_OUT
)
165 if (par
->hook_mask
& ((1 << NF_INET_PRE_ROUTING
) |
166 (1 << NF_INET_LOCAL_IN
)) &&
167 info
->flags
& XT_ADDRTYPE_LIMIT_IFACE_OUT
) {
168 errmsg
= "output interface limitation not valid in PREROUTING and INPUT";
172 if (par
->hook_mask
& ((1 << NF_INET_POST_ROUTING
) |
173 (1 << NF_INET_LOCAL_OUT
)) &&
174 info
->flags
& XT_ADDRTYPE_LIMIT_IFACE_IN
) {
175 errmsg
= "input interface limitation not valid in POSTROUTING and OUTPUT";
179 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
180 if (par
->family
== NFPROTO_IPV6
) {
181 if ((info
->source
| info
->dest
) & XT_ADDRTYPE_BLACKHOLE
) {
182 errmsg
= "ipv6 BLACKHOLE matching not supported";
185 if ((info
->source
| info
->dest
) >= XT_ADDRTYPE_PROHIBIT
) {
186 errmsg
= "ipv6 PROHIBIT (THROW, NAT ..) matching not supported";
189 if ((info
->source
| info
->dest
) & XT_ADDRTYPE_BROADCAST
) {
190 errmsg
= "ipv6 does not support BROADCAST matching";
197 pr_info_ratelimited("%s\n", errmsg
);
201 static struct xt_match addrtype_mt_reg
[] __read_mostly
= {
204 .family
= NFPROTO_IPV4
,
205 .match
= addrtype_mt_v0
,
206 .matchsize
= sizeof(struct xt_addrtype_info
),
211 .family
= NFPROTO_UNSPEC
,
213 .match
= addrtype_mt_v1
,
214 .checkentry
= addrtype_mt_checkentry_v1
,
215 .matchsize
= sizeof(struct xt_addrtype_info_v1
),
220 static int __init
addrtype_mt_init(void)
222 return xt_register_matches(addrtype_mt_reg
,
223 ARRAY_SIZE(addrtype_mt_reg
));
226 static void __exit
addrtype_mt_exit(void)
228 xt_unregister_matches(addrtype_mt_reg
, ARRAY_SIZE(addrtype_mt_reg
));
231 module_init(addrtype_mt_init
);
232 module_exit(addrtype_mt_exit
);