aboutsummaryrefslogtreecommitdiff
path: root/net/netfilter/xt_iprange.c
blob: 4f984dc60319645648a66403bcb2dd2f014efd23 (plain)
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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
 *	xt_iprange - Netfilter module to match IP address ranges
 *
 *	(C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
 *	(C) CC Computer Consultants GmbH, 2008
 *
 *	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/ipv6.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_iprange.h>
#include <linux/netfilter_ipv4/ipt_iprange.h>

static bool
iprange_mt_v0(const struct sk_buff *skb, const struct net_device *in,
              const struct net_device *out, const struct xt_match *match,
              const void *matchinfo, int offset, unsigned int protoff,
              bool *hotdrop)
{
	const struct ipt_iprange_info *info = matchinfo;
	const struct iphdr *iph = ip_hdr(skb);

	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)) {
			pr_debug("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 false;
		}
	}
	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)) {
			pr_debug("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 false;
		}
	}
	return true;
}

static bool
iprange_mt4(const struct sk_buff *skb, const struct net_device *in,
            const struct net_device *out, const struct xt_match *match,
            const void *matchinfo, int offset, unsigned int protoff,
            bool *hotdrop)
{
	const struct xt_iprange_mtinfo *info = matchinfo;
	const struct iphdr *iph = ip_hdr(skb);
	bool m;

	if (info->flags & IPRANGE_SRC) {
		m  = ntohl(iph->saddr) < ntohl(info->src_min.ip);
		m |= ntohl(iph->saddr) > ntohl(info->src_max.ip);
		m ^= info->flags & IPRANGE_SRC_INV;
		if (m) {
			pr_debug("src IP " NIPQUAD_FMT " NOT in range %s"
			         NIPQUAD_FMT "-" NIPQUAD_FMT "\n",
			         NIPQUAD(iph->saddr),
			         (info->flags & IPRANGE_SRC_INV) ? "(INV) " : "",
			         NIPQUAD(info->src_max.ip),
			         NIPQUAD(info->src_max.ip));
			return false;
		}
	}
	if (info->flags & IPRANGE_DST) {
		m  = ntohl(iph->daddr) < ntohl(info->dst_min.ip);
		m |= ntohl(iph->daddr) > ntohl(info->dst_max.ip);
		m ^= info->flags & IPRANGE_DST_INV;
		if (m) {
			pr_debug("dst IP " NIPQUAD_FMT " NOT in range %s"
			         NIPQUAD_FMT "-" NIPQUAD_FMT "\n",
			         NIPQUAD(iph->daddr),
			         (info->flags & IPRANGE_DST_INV) ? "(INV) " : "",
			         NIPQUAD(info->dst_min.ip),
			         NIPQUAD(info->dst_max.ip));
			return false;
		}
	}
	return true;
}

static inline int
iprange_ipv6_sub(const struct in6_addr *a, const struct in6_addr *b)
{
	unsigned int i;
	int r;

	for (i = 0; i < 4; ++i) {
		r = (__force u32)a->s6_addr32[i] - (__force u32)b->s6_addr32[i];
		if (r != 0)
			return r;
	}

	return 0;
}

static bool
iprange_mt6(const struct sk_buff *skb, const struct net_device *in,
            const struct net_device *out, const struct xt_match *match,
            const void *matchinfo, int offset, unsigned int protoff,
            bool *hotdrop)
{
	const struct xt_iprange_mtinfo *info = matchinfo;
	const struct ipv6hdr *iph = ipv6_hdr(skb);
	bool m;

	if (info->flags & IPRANGE_SRC) {
		m  = iprange_ipv6_sub(&iph->saddr, &info->src_min.in6) < 0;
		m |= iprange_ipv6_sub(&iph->saddr, &info->src_max.in6) > 0;
		m ^= info->flags & IPRANGE_SRC_INV;
		if (m)
			return false;
	}
	if (info->flags & IPRANGE_DST) {
		m  = iprange_ipv6_sub(&iph->daddr, &info->dst_min.in6) < 0;
		m |= iprange_ipv6_sub(&iph->daddr, &info->dst_max.in6) > 0;
		m ^= info->flags & IPRANGE_DST_INV;
		if (m)
			return false;
	}
	return true;
}

static struct xt_match iprange_mt_reg[] __read_mostly = {
	{
		.name      = "iprange",
		.revision  = 0,
		.family    = AF_INET,
		.match     = iprange_mt_v0,
		.matchsize = sizeof(struct ipt_iprange_info),
		.me        = THIS_MODULE,
	},
	{
		.name      = "iprange",
		.revision  = 1,
		.family    = AF_INET,
		.match     = iprange_mt4,
		.matchsize = sizeof(struct xt_iprange_mtinfo),
		.me        = THIS_MODULE,
	},
	{
		.name      = "iprange",
		.revision  = 1,
		.family    = AF_INET6,
		.match     = iprange_mt6,
		.matchsize = sizeof(struct xt_iprange_mtinfo),
		.me        = THIS_MODULE,
	},
};

static int __init iprange_mt_init(void)
{
	return xt_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
}

static void __exit iprange_mt_exit(void)
{
	xt_unregister_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
}

module_init(iprange_mt_init);
module_exit(iprange_mt_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>, Jan Engelhardt <jengelh@computergmbh.de>");
MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching");