Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * Filtering ARP tables module. | |
4 | * | |
5 | * Copyright (C) 2002 David S. Miller (davem@redhat.com) | |
6 | * | |
7 | */ | |
8 | ||
9 | #include <linux/module.h> | |
e3eaa991 | 10 | #include <linux/netfilter/x_tables.h> |
1da177e4 | 11 | #include <linux/netfilter_arp/arp_tables.h> |
5a0e3ad6 | 12 | #include <linux/slab.h> |
1da177e4 LT |
13 | |
14 | MODULE_LICENSE("GPL"); | |
15 | MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); | |
16 | MODULE_DESCRIPTION("arptables filter table"); | |
17 | ||
18 | #define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \ | |
19 | (1 << NF_ARP_FORWARD)) | |
20 | ||
b9e69e12 FW |
21 | static int __net_init arptable_filter_table_init(struct net *net); |
22 | ||
35aad0ff | 23 | static const struct xt_table packet_filter = { |
1da177e4 LT |
24 | .name = "filter", |
25 | .valid_hooks = FILTER_VALID_HOOKS, | |
1da177e4 | 26 | .me = THIS_MODULE, |
ee999d8b | 27 | .af = NFPROTO_ARP, |
2b95efe7 | 28 | .priority = NF_IP_PRI_FILTER, |
b9e69e12 | 29 | .table_init = arptable_filter_table_init, |
1da177e4 LT |
30 | }; |
31 | ||
32 | /* The work comes in here from netfilter.c */ | |
737535c5 | 33 | static unsigned int |
06198b34 | 34 | arptable_filter_hook(void *priv, struct sk_buff *skb, |
238e54c9 | 35 | const struct nf_hook_state *state) |
1da177e4 | 36 | { |
6cb8ff3f | 37 | return arpt_do_table(skb, state, state->net->ipv4.arptable_filter); |
3918fed5 AD |
38 | } |
39 | ||
2b95efe7 | 40 | static struct nf_hook_ops *arpfilter_ops __read_mostly; |
1da177e4 | 41 | |
b9e69e12 | 42 | static int __net_init arptable_filter_table_init(struct net *net) |
9ea0cb26 | 43 | { |
e3eaa991 | 44 | struct arpt_replace *repl; |
a67dd266 FW |
45 | int err; |
46 | ||
b9e69e12 FW |
47 | if (net->ipv4.arptable_filter) |
48 | return 0; | |
49 | ||
e3eaa991 JE |
50 | repl = arpt_alloc_initial_table(&packet_filter); |
51 | if (repl == NULL) | |
52 | return -ENOMEM; | |
a67dd266 FW |
53 | err = arpt_register_table(net, &packet_filter, repl, arpfilter_ops, |
54 | &net->ipv4.arptable_filter); | |
e3eaa991 | 55 | kfree(repl); |
a67dd266 | 56 | return err; |
9ea0cb26 AD |
57 | } |
58 | ||
59 | static void __net_exit arptable_filter_net_exit(struct net *net) | |
60 | { | |
b9e69e12 FW |
61 | if (!net->ipv4.arptable_filter) |
62 | return; | |
a67dd266 | 63 | arpt_unregister_table(net, net->ipv4.arptable_filter, arpfilter_ops); |
b9e69e12 | 64 | net->ipv4.arptable_filter = NULL; |
9ea0cb26 AD |
65 | } |
66 | ||
67 | static struct pernet_operations arptable_filter_net_ops = { | |
9ea0cb26 AD |
68 | .exit = arptable_filter_net_exit, |
69 | }; | |
70 | ||
65b4b4e8 | 71 | static int __init arptable_filter_init(void) |
1da177e4 | 72 | { |
964ddaa1 | 73 | int ret; |
1da177e4 | 74 | |
b9e69e12 FW |
75 | arpfilter_ops = xt_hook_ops_alloc(&packet_filter, arptable_filter_hook); |
76 | if (IS_ERR(arpfilter_ops)) | |
77 | return PTR_ERR(arpfilter_ops); | |
78 | ||
9ea0cb26 | 79 | ret = register_pernet_subsys(&arptable_filter_net_ops); |
b9e69e12 FW |
80 | if (ret < 0) { |
81 | kfree(arpfilter_ops); | |
9ea0cb26 | 82 | return ret; |
2b95efe7 | 83 | } |
1da177e4 | 84 | |
ff76def3 FW |
85 | ret = arptable_filter_table_init(&init_net); |
86 | if (ret) { | |
87 | unregister_pernet_subsys(&arptable_filter_net_ops); | |
88 | kfree(arpfilter_ops); | |
89 | } | |
90 | ||
1da177e4 LT |
91 | return ret; |
92 | } | |
93 | ||
65b4b4e8 | 94 | static void __exit arptable_filter_fini(void) |
1da177e4 | 95 | { |
9ea0cb26 | 96 | unregister_pernet_subsys(&arptable_filter_net_ops); |
b9e69e12 | 97 | kfree(arpfilter_ops); |
1da177e4 LT |
98 | } |
99 | ||
65b4b4e8 AM |
100 | module_init(arptable_filter_init); |
101 | module_exit(arptable_filter_fini); |