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
16 static bool
iprange_mt4(const struct sk_buff * skb,struct xt_action_param * par)17 iprange_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
52 static inline int
iprange_ipv6_lt(const struct in6_addr * a,const struct in6_addr * b)53 iprange_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
65 static bool
iprange_mt6(const struct sk_buff * skb,struct xt_action_param * par)66 iprange_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
101 static 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
iprange_mt_init(void)120 static int __init iprange_mt_init(void)
121 {
122 return xt_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
123 }
124
iprange_mt_exit(void)125 static void __exit iprange_mt_exit(void)
126 {
127 xt_unregister_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
128 }
129
130 module_init(iprange_mt_init);
131 module_exit(iprange_mt_exit);
132 MODULE_LICENSE("GPL");
133 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
134 MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
135 MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching");
136 MODULE_ALIAS("ipt_iprange");
137 MODULE_ALIAS("ip6t_iprange");
138
