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
94
95
96
97
98
99
|
/*
* iptables module to match IP address ranges
*
* (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_iprange.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
MODULE_DESCRIPTION("iptables arbitrary IP range match module");
#if 0
#define DEBUGP printk
#else
#define DEBUGP(format, args...)
#endif
static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo,
int offset, int *hotdrop)
{
const struct ipt_iprange_info *info = matchinfo;
const struct iphdr *iph = skb->nh.iph;
if (info->flags & IPRANGE_SRC) {
if (((ntohl(iph->saddr) < ntohl(info->src.min_ip))
|| (ntohl(iph->saddr) > ntohl(info->src.max_ip)))
^ !!(info->flags & IPRANGE_SRC_INV)) {
DEBUGP("src IP %u.%u.%u.%u NOT in range %s"
"%u.%u.%u.%u-%u.%u.%u.%u\n",
NIPQUAD(iph->saddr),
info->flags & IPRANGE_SRC_INV ? "(INV) " : "",
NIPQUAD(info->src.min_ip),
NIPQUAD(info->src.max_ip));
return 0;
}
}
if (info->flags & IPRANGE_DST) {
if (((ntohl(iph->daddr) < ntohl(info->dst.min_ip))
|| (ntohl(iph->daddr) > ntohl(info->dst.max_ip)))
^ !!(info->flags & IPRANGE_DST_INV)) {
DEBUGP("dst IP %u.%u.%u.%u NOT in range %s"
"%u.%u.%u.%u-%u.%u.%u.%u\n",
NIPQUAD(iph->daddr),
info->flags & IPRANGE_DST_INV ? "(INV) " : "",
NIPQUAD(info->dst.min_ip),
NIPQUAD(info->dst.max_ip));
return 0;
}
}
return 1;
}
static int check(const char *tablename,
const struct ipt_ip *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
/* verify size */
if (matchsize != IPT_ALIGN(sizeof(struct ipt_iprange_info)))
return 0;
return 1;
}
static struct ipt_match iprange_match =
{
.list = { NULL, NULL },
.name = "iprange",
.match = &match,
.checkentry = &check,
.destroy = NULL,
.me = THIS_MODULE
};
static int __init init(void)
{
return ipt_register_match(&iprange_match);
}
static void __exit fini(void)
{
ipt_unregister_match(&iprange_match);
}
module_init(init);
module_exit(fini);
|
