2 * Filtering ARP tables module.
4 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
8 #include <linux/module.h>
9 #include <linux/netfilter_arp/arp_tables.h>
11 MODULE_LICENSE("GPL");
12 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
13 MODULE_DESCRIPTION("arptables filter table");
15 #define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
16 (1 << NF_ARP_FORWARD))
20 struct arpt_replace repl;
21 struct arpt_standard entries[3];
22 struct arpt_error term;
23 } initial_table __net_initdata = {
26 .valid_hooks = FILTER_VALID_HOOKS,
28 .size = sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error),
31 [NF_ARP_OUT] = sizeof(struct arpt_standard),
32 [NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard),
36 [NF_ARP_OUT] = sizeof(struct arpt_standard),
37 [NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard),
41 ARPT_STANDARD_INIT(NF_ACCEPT), /* ARP_IN */
42 ARPT_STANDARD_INIT(NF_ACCEPT), /* ARP_OUT */
43 ARPT_STANDARD_INIT(NF_ACCEPT), /* ARP_FORWARD */
45 .term = ARPT_ERROR_INIT,
48 static const struct xt_table packet_filter = {
50 .valid_hooks = FILTER_VALID_HOOKS,
55 /* The work comes in here from netfilter.c */
57 arptable_filter_hook(unsigned int hook, struct sk_buff *skb,
58 const struct net_device *in, const struct net_device *out,
59 int (*okfn)(struct sk_buff *))
61 if (hook == NF_ARP_OUT)
62 return arpt_do_table(skb, hook, in, out,
63 dev_net(out)->ipv4.arptable_filter);
66 return arpt_do_table(skb, hook, in, out,
67 dev_net(in)->ipv4.arptable_filter);
70 static struct nf_hook_ops arpt_ops[] __read_mostly = {
72 .hook = arptable_filter_hook,
76 .priority = NF_IP_PRI_FILTER,
79 .hook = arptable_filter_hook,
82 .hooknum = NF_ARP_OUT,
83 .priority = NF_IP_PRI_FILTER,
86 .hook = arptable_filter_hook,
89 .hooknum = NF_ARP_FORWARD,
90 .priority = NF_IP_PRI_FILTER,
94 static int __net_init arptable_filter_net_init(struct net *net)
97 net->ipv4.arptable_filter =
98 arpt_register_table(net, &packet_filter, &initial_table.repl);
99 if (IS_ERR(net->ipv4.arptable_filter))
100 return PTR_ERR(net->ipv4.arptable_filter);
104 static void __net_exit arptable_filter_net_exit(struct net *net)
106 arpt_unregister_table(net->ipv4.arptable_filter);
109 static struct pernet_operations arptable_filter_net_ops = {
110 .init = arptable_filter_net_init,
111 .exit = arptable_filter_net_exit,
114 static int __init arptable_filter_init(void)
118 ret = register_pernet_subsys(&arptable_filter_net_ops);
122 ret = nf_register_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
128 unregister_pernet_subsys(&arptable_filter_net_ops);
132 static void __exit arptable_filter_fini(void)
134 nf_unregister_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
135 unregister_pernet_subsys(&arptable_filter_net_ops);
138 module_init(arptable_filter_init);
139 module_exit(arptable_filter_fini);