Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * ebtable_filter | |
3 | * | |
4 | * Authors: | |
5 | * Bart De Schuymer <bdschuym@pandora.be> | |
6 | * | |
7 | * April, 2002 | |
8 | * | |
9 | */ | |
10 | ||
11 | #include <linux/netfilter_bridge/ebtables.h> | |
12 | #include <linux/module.h> | |
13 | ||
14 | #define FILTER_VALID_HOOKS ((1 << NF_BR_LOCAL_IN) | (1 << NF_BR_FORWARD) | \ | |
15 | (1 << NF_BR_LOCAL_OUT)) | |
16 | ||
97ad8b53 | 17 | static struct ebt_entries initial_chains[] = { |
1da177e4 LT |
18 | { |
19 | .name = "INPUT", | |
20 | .policy = EBT_ACCEPT, | |
21 | }, | |
22 | { | |
23 | .name = "FORWARD", | |
24 | .policy = EBT_ACCEPT, | |
25 | }, | |
26 | { | |
27 | .name = "OUTPUT", | |
28 | .policy = EBT_ACCEPT, | |
29 | }, | |
30 | }; | |
31 | ||
97ad8b53 | 32 | static struct ebt_replace_kernel initial_table = { |
1da177e4 LT |
33 | .name = "filter", |
34 | .valid_hooks = FILTER_VALID_HOOKS, | |
35 | .entries_size = 3 * sizeof(struct ebt_entries), | |
36 | .hook_entry = { | |
37 | [NF_BR_LOCAL_IN] = &initial_chains[0], | |
38 | [NF_BR_FORWARD] = &initial_chains[1], | |
39 | [NF_BR_LOCAL_OUT] = &initial_chains[2], | |
40 | }, | |
41 | .entries = (char *)initial_chains, | |
42 | }; | |
43 | ||
44 | static int check(const struct ebt_table_info *info, unsigned int valid_hooks) | |
45 | { | |
46 | if (valid_hooks & ~FILTER_VALID_HOOKS) | |
47 | return -EINVAL; | |
48 | return 0; | |
49 | } | |
50 | ||
97ad8b53 | 51 | static const struct ebt_table frame_filter = { |
1da177e4 LT |
52 | .name = "filter", |
53 | .table = &initial_table, | |
9d6f229f | 54 | .valid_hooks = FILTER_VALID_HOOKS, |
1da177e4 LT |
55 | .check = check, |
56 | .me = THIS_MODULE, | |
57 | }; | |
58 | ||
59 | static unsigned int | |
795aa6ef PM |
60 | ebt_in_hook(const struct nf_hook_ops *ops, struct sk_buff *skb, |
61 | const struct net_device *in, const struct net_device *out, | |
62 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 63 | { |
795aa6ef PM |
64 | return ebt_do_table(ops->hooknum, skb, in, out, |
65 | dev_net(in)->xt.frame_filter); | |
4aad1093 AD |
66 | } |
67 | ||
68 | static unsigned int | |
795aa6ef PM |
69 | ebt_out_hook(const struct nf_hook_ops *ops, struct sk_buff *skb, |
70 | const struct net_device *in, const struct net_device *out, | |
71 | int (*okfn)(struct sk_buff *)) | |
4aad1093 | 72 | { |
795aa6ef PM |
73 | return ebt_do_table(ops->hooknum, skb, in, out, |
74 | dev_net(out)->xt.frame_filter); | |
1da177e4 LT |
75 | } |
76 | ||
1999414a | 77 | static struct nf_hook_ops ebt_ops_filter[] __read_mostly = { |
1da177e4 | 78 | { |
4aad1093 | 79 | .hook = ebt_in_hook, |
1da177e4 | 80 | .owner = THIS_MODULE, |
24c232d8 | 81 | .pf = NFPROTO_BRIDGE, |
1da177e4 LT |
82 | .hooknum = NF_BR_LOCAL_IN, |
83 | .priority = NF_BR_PRI_FILTER_BRIDGED, | |
84 | }, | |
85 | { | |
4aad1093 | 86 | .hook = ebt_in_hook, |
1da177e4 | 87 | .owner = THIS_MODULE, |
24c232d8 | 88 | .pf = NFPROTO_BRIDGE, |
1da177e4 LT |
89 | .hooknum = NF_BR_FORWARD, |
90 | .priority = NF_BR_PRI_FILTER_BRIDGED, | |
91 | }, | |
92 | { | |
4aad1093 | 93 | .hook = ebt_out_hook, |
1da177e4 | 94 | .owner = THIS_MODULE, |
24c232d8 | 95 | .pf = NFPROTO_BRIDGE, |
1da177e4 LT |
96 | .hooknum = NF_BR_LOCAL_OUT, |
97 | .priority = NF_BR_PRI_FILTER_OTHER, | |
98 | }, | |
99 | }; | |
100 | ||
4aad1093 AD |
101 | static int __net_init frame_filter_net_init(struct net *net) |
102 | { | |
103 | net->xt.frame_filter = ebt_register_table(net, &frame_filter); | |
8c6ffba0 | 104 | return PTR_ERR_OR_ZERO(net->xt.frame_filter); |
4aad1093 AD |
105 | } |
106 | ||
107 | static void __net_exit frame_filter_net_exit(struct net *net) | |
108 | { | |
f54e9367 | 109 | ebt_unregister_table(net, net->xt.frame_filter); |
4aad1093 AD |
110 | } |
111 | ||
112 | static struct pernet_operations frame_filter_net_ops = { | |
113 | .init = frame_filter_net_init, | |
114 | .exit = frame_filter_net_exit, | |
115 | }; | |
116 | ||
65b4b4e8 | 117 | static int __init ebtable_filter_init(void) |
1da177e4 | 118 | { |
e40f51a3 | 119 | int ret; |
1da177e4 | 120 | |
4aad1093 AD |
121 | ret = register_pernet_subsys(&frame_filter_net_ops); |
122 | if (ret < 0) | |
123 | return ret; | |
e40f51a3 AD |
124 | ret = nf_register_hooks(ebt_ops_filter, ARRAY_SIZE(ebt_ops_filter)); |
125 | if (ret < 0) | |
4aad1093 | 126 | unregister_pernet_subsys(&frame_filter_net_ops); |
1da177e4 LT |
127 | return ret; |
128 | } | |
129 | ||
65b4b4e8 | 130 | static void __exit ebtable_filter_fini(void) |
1da177e4 | 131 | { |
e40f51a3 | 132 | nf_unregister_hooks(ebt_ops_filter, ARRAY_SIZE(ebt_ops_filter)); |
4aad1093 | 133 | unregister_pernet_subsys(&frame_filter_net_ops); |
1da177e4 LT |
134 | } |
135 | ||
65b4b4e8 AM |
136 | module_init(ebtable_filter_init); |
137 | module_exit(ebtable_filter_fini); | |
1da177e4 | 138 | MODULE_LICENSE("GPL"); |