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 |
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 |
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 |
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(a: &iph->saddr, b: &info->src_min.in6); |
74 | m |= iprange_ipv6_lt(a: &info->src_max.in6, b: &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(a: &iph->daddr, b: &info->dst_min.in6); |
87 | m |= iprange_ipv6_lt(a: &info->dst_max.in6, b: &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 | |
120 | static int __init iprange_mt_init(void) |
121 | { |
122 | return xt_register_matches(match: iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg)); |
123 | } |
124 | |
125 | static void __exit iprange_mt_exit(void) |
126 | { |
127 | xt_unregister_matches(match: 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 | |