ipvs: convert lblc scheduler to rcu
[linux-3.10.git] / net / netfilter / xt_addrtype.c
1 /*
2  *  iptables module to match inet_addr_type() of an ip.
3  *
4  *  Copyright (c) 2004 Patrick McHardy <kaber@trash.net>
5  *  (C) 2007 Laszlo Attila Toth <panther@balabit.hu>
6  *
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.
10  */
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>
16 #include <linux/ip.h>
17 #include <net/route.h>
18
19 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
20 #include <net/ipv6.h>
21 #include <net/ip6_route.h>
22 #include <net/ip6_fib.h>
23 #endif
24
25 #include <linux/netfilter/xt_addrtype.h>
26 #include <linux/netfilter/x_tables.h>
27
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");
33
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)
37 {
38         const struct nf_afinfo *afinfo;
39         struct flowi6 flow;
40         struct rt6_info *rt;
41         u32 ret;
42         int route_err;
43
44         memset(&flow, 0, sizeof(flow));
45         flow.daddr = *addr;
46         if (dev)
47                 flow.flowi6_oif = dev->ifindex;
48
49         rcu_read_lock();
50
51         afinfo = nf_get_afinfo(NFPROTO_IPV6);
52         if (afinfo != NULL)
53                 route_err = afinfo->route(net, (struct dst_entry **)&rt,
54                                         flowi6_to_flowi(&flow), !!dev);
55         else
56                 route_err = 1;
57
58         rcu_read_unlock();
59
60         if (route_err)
61                 return XT_ADDRTYPE_UNREACHABLE;
62
63         if (rt->rt6i_flags & RTF_REJECT)
64                 ret = XT_ADDRTYPE_UNREACHABLE;
65         else
66                 ret = 0;
67
68         if (rt->rt6i_flags & RTF_LOCAL)
69                 ret |= XT_ADDRTYPE_LOCAL;
70         if (rt->rt6i_flags & RTF_ANYCAST)
71                 ret |= XT_ADDRTYPE_ANYCAST;
72
73
74         dst_release(&rt->dst);
75         return ret;
76 }
77
78 static bool match_type6(struct net *net, const struct net_device *dev,
79                                 const struct in6_addr *addr, u16 mask)
80 {
81         int addr_type = ipv6_addr_type(addr);
82
83         if ((mask & XT_ADDRTYPE_MULTICAST) &&
84             !(addr_type & IPV6_ADDR_MULTICAST))
85                 return false;
86         if ((mask & XT_ADDRTYPE_UNICAST) && !(addr_type & IPV6_ADDR_UNICAST))
87                 return false;
88         if ((mask & XT_ADDRTYPE_UNSPEC) && addr_type != IPV6_ADDR_ANY)
89                 return false;
90
91         if ((XT_ADDRTYPE_LOCAL | XT_ADDRTYPE_ANYCAST |
92              XT_ADDRTYPE_UNREACHABLE) & mask)
93                 return !!(mask & match_lookup_rt6(net, dev, addr));
94         return true;
95 }
96
97 static bool
98 addrtype_mt6(struct net *net, const struct net_device *dev,
99         const struct sk_buff *skb, const struct xt_addrtype_info_v1 *info)
100 {
101         const struct ipv6hdr *iph = ipv6_hdr(skb);
102         bool ret = true;
103
104         if (info->source)
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);
110         return ret;
111 }
112 #endif
113
114 static inline bool match_type(struct net *net, const struct net_device *dev,
115                               __be32 addr, u_int16_t mask)
116 {
117         return !!(mask & (1 << inet_dev_addr_type(net, dev, addr)));
118 }
119
120 static bool
121 addrtype_mt_v0(const struct sk_buff *skb, struct xt_action_param *par)
122 {
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);
126         bool ret = true;
127
128         if (info->source)
129                 ret &= match_type(net, NULL, iph->saddr, info->source) ^
130                        info->invert_source;
131         if (info->dest)
132                 ret &= match_type(net, NULL, iph->daddr, info->dest) ^
133                        info->invert_dest;
134
135         return ret;
136 }
137
138 static bool
139 addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
140 {
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;
145         bool ret = true;
146
147         if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN)
148                 dev = par->in;
149         else if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT)
150                 dev = par->out;
151
152 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
153         if (par->family == NFPROTO_IPV6)
154                 return addrtype_mt6(net, dev, skb, info);
155 #endif
156         iph = ip_hdr(skb);
157         if (info->source)
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);
163         return ret;
164 }
165
166 static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par)
167 {
168         struct xt_addrtype_info_v1 *info = par->matchinfo;
169
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");
174                 return -EINVAL;
175         }
176
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");
182                 return -EINVAL;
183         }
184
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");
190                 return -EINVAL;
191         }
192
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");
197                         return -EINVAL;
198                 }
199                 if ((info->source | info->dest) >= XT_ADDRTYPE_PROHIBIT) {
200                         pr_err("ipv6 PROHIBT (THROW, NAT ..) matching not supported\n");
201                         return -EINVAL;
202                 }
203                 if ((info->source | info->dest) & XT_ADDRTYPE_BROADCAST) {
204                         pr_err("ipv6 does not support BROADCAST matching\n");
205                         return -EINVAL;
206                 }
207         }
208 #endif
209         return 0;
210 }
211
212 static struct xt_match addrtype_mt_reg[] __read_mostly = {
213         {
214                 .name           = "addrtype",
215                 .family         = NFPROTO_IPV4,
216                 .match          = addrtype_mt_v0,
217                 .matchsize      = sizeof(struct xt_addrtype_info),
218                 .me             = THIS_MODULE
219         },
220         {
221                 .name           = "addrtype",
222                 .family         = NFPROTO_UNSPEC,
223                 .revision       = 1,
224                 .match          = addrtype_mt_v1,
225                 .checkentry     = addrtype_mt_checkentry_v1,
226                 .matchsize      = sizeof(struct xt_addrtype_info_v1),
227                 .me             = THIS_MODULE
228         }
229 };
230
231 static int __init addrtype_mt_init(void)
232 {
233         return xt_register_matches(addrtype_mt_reg,
234                                    ARRAY_SIZE(addrtype_mt_reg));
235 }
236
237 static void __exit addrtype_mt_exit(void)
238 {
239         xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg));
240 }
241
242 module_init(addrtype_mt_init);
243 module_exit(addrtype_mt_exit);