1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
/*
* ebtable_filter
*
* Authors:
* Bart De Schuymer <bart.de.schuymer@pandora.be>
*
* April, 2002
*
*/
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge.h>
#include <linux/module.h>
#define FILTER_VALID_HOOKS ((1 << NF_BR_LOCAL_IN) | (1 << NF_BR_FORWARD) | \
(1 << NF_BR_LOCAL_OUT))
static struct ebt_entries initial_chains[] =
{
{0, EBT_ACCEPT, 0},
{0, EBT_ACCEPT, 0},
{0, EBT_ACCEPT, 0}
};
static struct ebt_replace initial_table =
{
"filter", FILTER_VALID_HOOKS, 0, 3 * sizeof(struct ebt_entries),
{ [NF_BR_LOCAL_IN]&initial_chains[0], [NF_BR_FORWARD]&initial_chains[1],
[NF_BR_LOCAL_OUT]&initial_chains[2] },{},
0, NULL, (char *)initial_chains
};
static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
{
if (valid_hooks & ~FILTER_VALID_HOOKS)
return -EINVAL;
return 0;
}
static struct ebt_table frame_filter =
{
{NULL, NULL}, "filter", &initial_table, FILTER_VALID_HOOKS,
RW_LOCK_UNLOCKED, check, NULL
};
static unsigned int ebt_hook (unsigned int hook, struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
return ebt_do_table(hook, pskb, in, out, &frame_filter);
}
static struct nf_hook_ops ebt_ops_filter[] = {
{ { NULL, NULL }, ebt_hook, PF_BRIDGE, NF_BR_LOCAL_IN,
NF_BR_PRI_FILTER_BRIDGED},
{ { NULL, NULL }, ebt_hook, PF_BRIDGE, NF_BR_FORWARD,
NF_BR_PRI_FILTER_BRIDGED},
{ { NULL, NULL }, ebt_hook, PF_BRIDGE, NF_BR_LOCAL_OUT,
NF_BR_PRI_FILTER_OTHER}
};
static int __init init(void)
{
int i, j, ret;
ret = ebt_register_table(&frame_filter);
if (ret < 0)
return ret;
for (i = 0; i < sizeof(ebt_ops_filter) / sizeof(ebt_ops_filter[0]); i++)
if ((ret = nf_register_hook(&ebt_ops_filter[i])) < 0)
goto cleanup;
return ret;
cleanup:
for (j = 0; j < i; j++)
nf_unregister_hook(&ebt_ops_filter[j]);
ebt_unregister_table(&frame_filter);
return ret;
}
static void __exit fini(void)
{
int i;
for (i = 0; i < sizeof(ebt_ops_filter) / sizeof(ebt_ops_filter[0]); i++)
nf_unregister_hook(&ebt_ops_filter[i]);
ebt_unregister_table(&frame_filter);
}
module_init(init);
module_exit(fini);
EXPORT_NO_SYMBOLS;
MODULE_LICENSE("GPL");
|
