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
|
/* Kernel module to match MAC address parameters. */
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/if_ether.h>
#include <linux/netfilter_ipv4/ipt_mac.h>
#include <linux/netfilter_ipv4/ip_tables.h>
static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo,
int offset,
const void *hdr,
u_int16_t datalen,
int *hotdrop)
{
const struct ipt_mac_info *info = matchinfo;
/* Is mac pointer valid? */
return (skb->mac.raw >= skb->head
&& (skb->mac.raw + ETH_HLEN) <= skb->data
/* If so, compare... */
&& ((memcmp(skb->mac.ethernet->h_source, info->srcaddr, ETH_ALEN)
== 0) ^ info->invert));
}
static int
ipt_mac_checkentry(const char *tablename,
const struct ipt_ip *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
/* FORWARD isn't always valid, but it's nice to be able to do --RR */
if (hook_mask
& ~((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_IN)
| (1 << NF_IP_FORWARD))) {
printk("ipt_mac: only valid for PRE_ROUTING, LOCAL_IN or FORWARD.\n");
return 0;
}
if (matchsize != IPT_ALIGN(sizeof(struct ipt_mac_info)))
return 0;
return 1;
}
static struct ipt_match mac_match
= { { NULL, NULL }, "mac", &match, &ipt_mac_checkentry, NULL, THIS_MODULE };
static int __init init(void)
{
return ipt_register_match(&mac_match);
}
static void __exit fini(void)
{
ipt_unregister_match(&mac_match);
}
module_init(init);
module_exit(fini);
MODULE_LICENSE("GPL");
|
