1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *	xt_iprange - Netfilter module to match IP address ranges
4 *
5 *	(C) 2003 Jozsef Kadlecsik <kadlec@netfilter.org>
6 *	(C) CC Computer Consultants GmbH, 2008
7 */
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9#include <linux/module.h>
10#include <linux/skbuff.h>
11#include <linux/ip.h>
12#include <linux/ipv6.h>
13#include <linux/netfilter/x_tables.h>
14#include <linux/netfilter/xt_iprange.h>
15
16static bool
17iprange_mt4(const struct sk_buff *skb, struct xt_action_param *par)
18{
19	const struct xt_iprange_mtinfo *info = par->matchinfo;
20	const struct iphdr *iph = ip_hdr(skb);
21	bool m;
22
23	if (info->flags & IPRANGE_SRC) {
24		m  = ntohl(iph->saddr) < ntohl(info->src_min.ip);
25		m |= ntohl(iph->saddr) > ntohl(info->src_max.ip);
26		m ^= !!(info->flags & IPRANGE_SRC_INV);
27		if (m) {
28			pr_debug("src IP %pI4 NOT in range %s%pI4-%pI4\n",
29			         &iph->saddr,
30			         (info->flags & IPRANGE_SRC_INV) ? "(INV) " : "",
31			         &info->src_min.ip,
32			         &info->src_max.ip);
33			return false;
34		}
35	}
36	if (info->flags & IPRANGE_DST) {
37		m  = ntohl(iph->daddr) < ntohl(info->dst_min.ip);
38		m |= ntohl(iph->daddr) > ntohl(info->dst_max.ip);
39		m ^= !!(info->flags & IPRANGE_DST_INV);
40		if (m) {
41			pr_debug("dst IP %pI4 NOT in range %s%pI4-%pI4\n",
42			         &iph->daddr,
43			         (info->flags & IPRANGE_DST_INV) ? "(INV) " : "",
44			         &info->dst_min.ip,
45			         &info->dst_max.ip);
46			return false;
47		}
48	}
49	return true;
50}
51
52static inline int
53iprange_ipv6_lt(const struct in6_addr *a, const struct in6_addr *b)
54{
55	unsigned int i;
56
57	for (i = 0; i < 4; ++i) {
58		if (a->s6_addr32[i] != b->s6_addr32[i])
59			return ntohl(a->s6_addr32[i]) < ntohl(b->s6_addr32[i]);
60	}
61
62	return 0;
63}
64
65static bool
66iprange_mt6(const struct sk_buff *skb, struct xt_action_param *par)
67{
68	const struct xt_iprange_mtinfo *info = par->matchinfo;
69	const struct ipv6hdr *iph = ipv6_hdr(skb);
70	bool m;
71
72	if (info->flags & IPRANGE_SRC) {
73		m  = iprange_ipv6_lt(&iph->saddr, &info->src_min.in6);
74		m |= iprange_ipv6_lt(&info->src_max.in6, &iph->saddr);
75		m ^= !!(info->flags & IPRANGE_SRC_INV);
76		if (m) {
77			pr_debug("src IP %pI6 NOT in range %s%pI6-%pI6\n",
78				 &iph->saddr,
79				 (info->flags & IPRANGE_SRC_INV) ? "(INV) " : "",
80				 &info->src_min.in6,
81				 &info->src_max.in6);
82			return false;
83		}
84	}
85	if (info->flags & IPRANGE_DST) {
86		m  = iprange_ipv6_lt(&iph->daddr, &info->dst_min.in6);
87		m |= iprange_ipv6_lt(&info->dst_max.in6, &iph->daddr);
88		m ^= !!(info->flags & IPRANGE_DST_INV);
89		if (m) {
90			pr_debug("dst IP %pI6 NOT in range %s%pI6-%pI6\n",
91				 &iph->daddr,
92				 (info->flags & IPRANGE_DST_INV) ? "(INV) " : "",
93				 &info->dst_min.in6,
94				 &info->dst_max.in6);
95			return false;
96		}
97	}
98	return true;
99}
100
101static struct xt_match iprange_mt_reg[] __read_mostly = {
102	{
103		.name      = "iprange",
104		.revision  = 1,
105		.family    = NFPROTO_IPV4,
106		.match     = iprange_mt4,
107		.matchsize = sizeof(struct xt_iprange_mtinfo),
108		.me        = THIS_MODULE,
109	},
110	{
111		.name      = "iprange",
112		.revision  = 1,
113		.family    = NFPROTO_IPV6,
114		.match     = iprange_mt6,
115		.matchsize = sizeof(struct xt_iprange_mtinfo),
116		.me        = THIS_MODULE,
117	},
118};
119
120static int __init iprange_mt_init(void)
121{
122	return xt_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
123}
124
125static void __exit iprange_mt_exit(void)
126{
127	xt_unregister_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
128}
129
130module_init(iprange_mt_init);
131module_exit(iprange_mt_exit);
132MODULE_LICENSE("GPL");
133MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
134MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
135MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching");
136MODULE_ALIAS("ipt_iprange");
137MODULE_ALIAS("ip6t_iprange");
138