Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Filtering ARP tables module. | |
3 | * | |
4 | * Copyright (C) 2002 David S. Miller (davem@redhat.com) | |
5 | * | |
6 | */ | |
7 | ||
8 | #include <linux/module.h> | |
e3eaa991 | 9 | #include <linux/netfilter/x_tables.h> |
1da177e4 LT |
10 | #include <linux/netfilter_arp/arp_tables.h> |
11 | ||
12 | MODULE_LICENSE("GPL"); | |
13 | MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); | |
14 | MODULE_DESCRIPTION("arptables filter table"); | |
15 | ||
16 | #define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \ | |
17 | (1 << NF_ARP_FORWARD)) | |
18 | ||
35aad0ff | 19 | static const struct xt_table packet_filter = { |
1da177e4 LT |
20 | .name = "filter", |
21 | .valid_hooks = FILTER_VALID_HOOKS, | |
1da177e4 | 22 | .me = THIS_MODULE, |
ee999d8b | 23 | .af = NFPROTO_ARP, |
2b95efe7 | 24 | .priority = NF_IP_PRI_FILTER, |
1da177e4 LT |
25 | }; |
26 | ||
27 | /* The work comes in here from netfilter.c */ | |
737535c5 JE |
28 | static unsigned int |
29 | arptable_filter_hook(unsigned int hook, struct sk_buff *skb, | |
30 | const struct net_device *in, const struct net_device *out, | |
31 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 32 | { |
2b21e051 | 33 | const struct net *net = dev_net((in != NULL) ? in : out); |
3918fed5 | 34 | |
2b21e051 | 35 | return arpt_do_table(skb, hook, in, out, net->ipv4.arptable_filter); |
3918fed5 AD |
36 | } |
37 | ||
2b95efe7 | 38 | static struct nf_hook_ops *arpfilter_ops __read_mostly; |
1da177e4 | 39 | |
9ea0cb26 AD |
40 | static int __net_init arptable_filter_net_init(struct net *net) |
41 | { | |
e3eaa991 JE |
42 | struct arpt_replace *repl; |
43 | ||
44 | repl = arpt_alloc_initial_table(&packet_filter); | |
45 | if (repl == NULL) | |
46 | return -ENOMEM; | |
9ea0cb26 | 47 | net->ipv4.arptable_filter = |
e3eaa991 JE |
48 | arpt_register_table(net, &packet_filter, repl); |
49 | kfree(repl); | |
9ea0cb26 AD |
50 | if (IS_ERR(net->ipv4.arptable_filter)) |
51 | return PTR_ERR(net->ipv4.arptable_filter); | |
52 | return 0; | |
53 | } | |
54 | ||
55 | static void __net_exit arptable_filter_net_exit(struct net *net) | |
56 | { | |
57 | arpt_unregister_table(net->ipv4.arptable_filter); | |
58 | } | |
59 | ||
60 | static struct pernet_operations arptable_filter_net_ops = { | |
61 | .init = arptable_filter_net_init, | |
62 | .exit = arptable_filter_net_exit, | |
63 | }; | |
64 | ||
65b4b4e8 | 65 | static int __init arptable_filter_init(void) |
1da177e4 | 66 | { |
964ddaa1 | 67 | int ret; |
1da177e4 | 68 | |
9ea0cb26 AD |
69 | ret = register_pernet_subsys(&arptable_filter_net_ops); |
70 | if (ret < 0) | |
71 | return ret; | |
1da177e4 | 72 | |
2b95efe7 JE |
73 | arpfilter_ops = xt_hook_link(&packet_filter, arptable_filter_hook); |
74 | if (IS_ERR(arpfilter_ops)) { | |
75 | ret = PTR_ERR(arpfilter_ops); | |
964ddaa1 | 76 | goto cleanup_table; |
2b95efe7 | 77 | } |
1da177e4 LT |
78 | return ret; |
79 | ||
964ddaa1 | 80 | cleanup_table: |
9ea0cb26 | 81 | unregister_pernet_subsys(&arptable_filter_net_ops); |
1da177e4 LT |
82 | return ret; |
83 | } | |
84 | ||
65b4b4e8 | 85 | static void __exit arptable_filter_fini(void) |
1da177e4 | 86 | { |
2b95efe7 | 87 | xt_hook_unlink(&packet_filter, arpfilter_ops); |
9ea0cb26 | 88 | unregister_pernet_subsys(&arptable_filter_net_ops); |
1da177e4 LT |
89 | } |
90 | ||
65b4b4e8 AM |
91 | module_init(arptable_filter_init); |
92 | module_exit(arptable_filter_fini); |