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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * iptables module to match inet_addr_type() of an ip. | |
4 | * | |
5 | * Copyright (c) 2004 Patrick McHardy <kaber@trash.net> | |
e2cf5ecb | 6 | * (C) 2007 Laszlo Attila Toth <panther@balabit.hu> |
1da177e4 | 7 | */ |
ff67e4e4 | 8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 LT |
9 | #include <linux/kernel.h> |
10 | #include <linux/module.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/netdevice.h> | |
13 | #include <linux/ip.h> | |
14 | #include <net/route.h> | |
15 | ||
c0cd1156 | 16 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
2f5dc631 FW |
17 | #include <net/ipv6.h> |
18 | #include <net/ip6_route.h> | |
19 | #include <net/ip6_fib.h> | |
20 | #endif | |
21 | ||
2a7851bf | 22 | #include <linux/netfilter_ipv6.h> |
de81bbea | 23 | #include <linux/netfilter/xt_addrtype.h> |
6709dbbb | 24 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
25 | |
26 | MODULE_LICENSE("GPL"); | |
27 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
de81bbea FW |
28 | MODULE_DESCRIPTION("Xtables: address type match"); |
29 | MODULE_ALIAS("ipt_addrtype"); | |
2f5dc631 FW |
30 | MODULE_ALIAS("ip6t_addrtype"); |
31 | ||
c0cd1156 | 32 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
b7225041 | 33 | static u32 match_lookup_rt6(struct net *net, const struct net_device *dev, |
2a7851bf | 34 | const struct in6_addr *addr, u16 mask) |
2f5dc631 | 35 | { |
b7225041 FW |
36 | struct flowi6 flow; |
37 | struct rt6_info *rt; | |
2a7851bf | 38 | u32 ret = 0; |
b7225041 | 39 | int route_err; |
2f5dc631 | 40 | |
b7225041 | 41 | memset(&flow, 0, sizeof(flow)); |
4e3fd7a0 | 42 | flow.daddr = *addr; |
b7225041 FW |
43 | if (dev) |
44 | flow.flowi6_oif = dev->ifindex; | |
45 | ||
ac02bcf9 FW |
46 | if (dev && (mask & XT_ADDRTYPE_LOCAL)) { |
47 | if (nf_ipv6_chk_addr(net, addr, dev, true)) | |
48 | ret = XT_ADDRTYPE_LOCAL; | |
2a7851bf | 49 | } |
b7225041 | 50 | |
ac02bcf9 FW |
51 | route_err = nf_ip6_route(net, (struct dst_entry **)&rt, |
52 | flowi6_to_flowi(&flow), false); | |
b7225041 | 53 | if (route_err) |
2f5dc631 FW |
54 | return XT_ADDRTYPE_UNREACHABLE; |
55 | ||
56 | if (rt->rt6i_flags & RTF_REJECT) | |
57 | ret = XT_ADDRTYPE_UNREACHABLE; | |
2f5dc631 | 58 | |
2a7851bf | 59 | if (dev == NULL && rt->rt6i_flags & RTF_LOCAL) |
2f5dc631 | 60 | ret |= XT_ADDRTYPE_LOCAL; |
2647a9b0 | 61 | if (ipv6_anycast_destination((struct dst_entry *)rt, addr)) |
2f5dc631 | 62 | ret |= XT_ADDRTYPE_ANYCAST; |
b7225041 | 63 | |
b7225041 | 64 | dst_release(&rt->dst); |
2f5dc631 FW |
65 | return ret; |
66 | } | |
67 | ||
68 | static bool match_type6(struct net *net, const struct net_device *dev, | |
69 | const struct in6_addr *addr, u16 mask) | |
70 | { | |
71 | int addr_type = ipv6_addr_type(addr); | |
72 | ||
73 | if ((mask & XT_ADDRTYPE_MULTICAST) && | |
74 | !(addr_type & IPV6_ADDR_MULTICAST)) | |
75 | return false; | |
76 | if ((mask & XT_ADDRTYPE_UNICAST) && !(addr_type & IPV6_ADDR_UNICAST)) | |
77 | return false; | |
78 | if ((mask & XT_ADDRTYPE_UNSPEC) && addr_type != IPV6_ADDR_ANY) | |
79 | return false; | |
80 | ||
81 | if ((XT_ADDRTYPE_LOCAL | XT_ADDRTYPE_ANYCAST | | |
b7225041 | 82 | XT_ADDRTYPE_UNREACHABLE) & mask) |
2a7851bf | 83 | return !!(mask & match_lookup_rt6(net, dev, addr, mask)); |
2f5dc631 FW |
84 | return true; |
85 | } | |
86 | ||
87 | static bool | |
88 | addrtype_mt6(struct net *net, const struct net_device *dev, | |
89 | const struct sk_buff *skb, const struct xt_addrtype_info_v1 *info) | |
90 | { | |
91 | const struct ipv6hdr *iph = ipv6_hdr(skb); | |
92 | bool ret = true; | |
93 | ||
94 | if (info->source) | |
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); | |
100 | return ret; | |
101 | } | |
102 | #endif | |
1da177e4 | 103 | |
d4ec52ba AD |
104 | static inline bool match_type(struct net *net, const struct net_device *dev, |
105 | __be32 addr, u_int16_t mask) | |
1da177e4 | 106 | { |
d4ec52ba | 107 | return !!(mask & (1 << inet_dev_addr_type(net, dev, addr))); |
1da177e4 LT |
108 | } |
109 | ||
d3c5ee6d | 110 | static bool |
62fc8051 | 111 | addrtype_mt_v0(const struct sk_buff *skb, struct xt_action_param *par) |
1da177e4 | 112 | { |
613dbd95 | 113 | struct net *net = xt_net(par); |
de81bbea | 114 | const struct xt_addrtype_info *info = par->matchinfo; |
eddc9ec5 | 115 | const struct iphdr *iph = ip_hdr(skb); |
1d93a9cb | 116 | bool ret = true; |
1da177e4 LT |
117 | |
118 | if (info->source) | |
d4ec52ba | 119 | ret &= match_type(net, NULL, iph->saddr, info->source) ^ |
e2cf5ecb | 120 | info->invert_source; |
1da177e4 | 121 | if (info->dest) |
d4ec52ba | 122 | ret &= match_type(net, NULL, iph->daddr, info->dest) ^ |
e2cf5ecb | 123 | info->invert_dest; |
e905a9ed | 124 | |
1da177e4 LT |
125 | return ret; |
126 | } | |
127 | ||
e2cf5ecb | 128 | static bool |
62fc8051 | 129 | addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) |
e2cf5ecb | 130 | { |
613dbd95 | 131 | struct net *net = xt_net(par); |
de81bbea | 132 | const struct xt_addrtype_info_v1 *info = par->matchinfo; |
2f5dc631 | 133 | const struct iphdr *iph; |
e2cf5ecb LAT |
134 | const struct net_device *dev = NULL; |
135 | bool ret = true; | |
136 | ||
de81bbea | 137 | if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN) |
613dbd95 | 138 | dev = xt_in(par); |
de81bbea | 139 | else if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) |
613dbd95 | 140 | dev = xt_out(par); |
e2cf5ecb | 141 | |
c0cd1156 | 142 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
613dbd95 | 143 | if (xt_family(par) == NFPROTO_IPV6) |
2f5dc631 FW |
144 | return addrtype_mt6(net, dev, skb, info); |
145 | #endif | |
146 | iph = ip_hdr(skb); | |
e2cf5ecb | 147 | if (info->source) |
d4ec52ba | 148 | ret &= match_type(net, dev, iph->saddr, info->source) ^ |
de81bbea | 149 | (info->flags & XT_ADDRTYPE_INVERT_SOURCE); |
e2cf5ecb | 150 | if (ret && info->dest) |
d4ec52ba | 151 | ret &= match_type(net, dev, iph->daddr, info->dest) ^ |
de81bbea | 152 | !!(info->flags & XT_ADDRTYPE_INVERT_DEST); |
e2cf5ecb LAT |
153 | return ret; |
154 | } | |
155 | ||
b0f38452 | 156 | static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par) |
e2cf5ecb | 157 | { |
c08e5e1e | 158 | const char *errmsg = "both incoming and outgoing interface limitation cannot be selected"; |
de81bbea | 159 | struct xt_addrtype_info_v1 *info = par->matchinfo; |
e2cf5ecb | 160 | |
de81bbea | 161 | if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN && |
c08e5e1e FW |
162 | info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) |
163 | goto err; | |
e2cf5ecb | 164 | |
9b4fce7a JE |
165 | if (par->hook_mask & ((1 << NF_INET_PRE_ROUTING) | |
166 | (1 << NF_INET_LOCAL_IN)) && | |
de81bbea | 167 | info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) { |
c08e5e1e FW |
168 | errmsg = "output interface limitation not valid in PREROUTING and INPUT"; |
169 | goto err; | |
e2cf5ecb LAT |
170 | } |
171 | ||
9b4fce7a JE |
172 | if (par->hook_mask & ((1 << NF_INET_POST_ROUTING) | |
173 | (1 << NF_INET_LOCAL_OUT)) && | |
de81bbea | 174 | info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN) { |
c08e5e1e FW |
175 | errmsg = "input interface limitation not valid in POSTROUTING and OUTPUT"; |
176 | goto err; | |
e2cf5ecb LAT |
177 | } |
178 | ||
c0cd1156 | 179 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
2f5dc631 FW |
180 | if (par->family == NFPROTO_IPV6) { |
181 | if ((info->source | info->dest) & XT_ADDRTYPE_BLACKHOLE) { | |
c08e5e1e FW |
182 | errmsg = "ipv6 BLACKHOLE matching not supported"; |
183 | goto err; | |
2f5dc631 FW |
184 | } |
185 | if ((info->source | info->dest) >= XT_ADDRTYPE_PROHIBIT) { | |
c08e5e1e FW |
186 | errmsg = "ipv6 PROHIBIT (THROW, NAT ..) matching not supported"; |
187 | goto err; | |
2f5dc631 FW |
188 | } |
189 | if ((info->source | info->dest) & XT_ADDRTYPE_BROADCAST) { | |
c08e5e1e FW |
190 | errmsg = "ipv6 does not support BROADCAST matching"; |
191 | goto err; | |
2f5dc631 FW |
192 | } |
193 | } | |
194 | #endif | |
bd414ee6 | 195 | return 0; |
c08e5e1e FW |
196 | err: |
197 | pr_info_ratelimited("%s\n", errmsg); | |
198 | return -EINVAL; | |
e2cf5ecb LAT |
199 | } |
200 | ||
201 | static struct xt_match addrtype_mt_reg[] __read_mostly = { | |
202 | { | |
203 | .name = "addrtype", | |
ee999d8b | 204 | .family = NFPROTO_IPV4, |
e2cf5ecb | 205 | .match = addrtype_mt_v0, |
de81bbea | 206 | .matchsize = sizeof(struct xt_addrtype_info), |
e2cf5ecb LAT |
207 | .me = THIS_MODULE |
208 | }, | |
209 | { | |
210 | .name = "addrtype", | |
2f5dc631 | 211 | .family = NFPROTO_UNSPEC, |
e2cf5ecb LAT |
212 | .revision = 1, |
213 | .match = addrtype_mt_v1, | |
214 | .checkentry = addrtype_mt_checkentry_v1, | |
de81bbea | 215 | .matchsize = sizeof(struct xt_addrtype_info_v1), |
e2cf5ecb LAT |
216 | .me = THIS_MODULE |
217 | } | |
1da177e4 LT |
218 | }; |
219 | ||
d3c5ee6d | 220 | static int __init addrtype_mt_init(void) |
1da177e4 | 221 | { |
e2cf5ecb LAT |
222 | return xt_register_matches(addrtype_mt_reg, |
223 | ARRAY_SIZE(addrtype_mt_reg)); | |
1da177e4 LT |
224 | } |
225 | ||
d3c5ee6d | 226 | static void __exit addrtype_mt_exit(void) |
1da177e4 | 227 | { |
e2cf5ecb | 228 | xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg)); |
1da177e4 LT |
229 | } |
230 | ||
d3c5ee6d JE |
231 | module_init(addrtype_mt_init); |
232 | module_exit(addrtype_mt_exit); |