| 1 | /* |
| 2 | * xt_iprange - Netfilter module to match IP address ranges |
| 3 | * |
| 4 | * (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> |
| 5 | * (C) CC Computer Consultants GmbH, 2008 |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/skbuff.h> |
| 14 | #include <linux/ip.h> |
| 15 | #include <linux/ipv6.h> |
| 16 | #include <linux/netfilter/x_tables.h> |
| 17 | #include <linux/netfilter/xt_iprange.h> |
| 18 | |
| 19 | static bool |
| 20 | iprange_mt4(const struct sk_buff *skb, struct xt_action_param *par) |
| 21 | { |
| 22 | const struct xt_iprange_mtinfo *info = par->matchinfo; |
| 23 | const struct iphdr *iph = ip_hdr(skb); |
| 24 | bool m; |
| 25 | |
| 26 | if (info->flags & IPRANGE_SRC) { |
| 27 | m = ntohl(iph->saddr) < ntohl(info->src_min.ip); |
| 28 | m |= ntohl(iph->saddr) > ntohl(info->src_max.ip); |
| 29 | m ^= !!(info->flags & IPRANGE_SRC_INV); |
| 30 | if (m) { |
| 31 | pr_debug("src IP %pI4 NOT in range %s%pI4-%pI4\n", |
| 32 | &iph->saddr, |
| 33 | (info->flags & IPRANGE_SRC_INV) ? "(INV) " : "", |
| 34 | &info->src_min.ip, |
| 35 | &info->src_max.ip); |
| 36 | return false; |
| 37 | } |
| 38 | } |
| 39 | if (info->flags & IPRANGE_DST) { |
| 40 | m = ntohl(iph->daddr) < ntohl(info->dst_min.ip); |
| 41 | m |= ntohl(iph->daddr) > ntohl(info->dst_max.ip); |
| 42 | m ^= !!(info->flags & IPRANGE_DST_INV); |
| 43 | if (m) { |
| 44 | pr_debug("dst IP %pI4 NOT in range %s%pI4-%pI4\n", |
| 45 | &iph->daddr, |
| 46 | (info->flags & IPRANGE_DST_INV) ? "(INV) " : "", |
| 47 | &info->dst_min.ip, |
| 48 | &info->dst_max.ip); |
| 49 | return false; |
| 50 | } |
| 51 | } |
| 52 | return true; |
| 53 | } |
| 54 | |
| 55 | static inline int |
| 56 | iprange_ipv6_lt(const struct in6_addr *a, const struct in6_addr *b) |
| 57 | { |
| 58 | unsigned int i; |
| 59 | |
| 60 | for (i = 0; i < 4; ++i) { |
| 61 | if (a->s6_addr32[i] != b->s6_addr32[i]) |
| 62 | return ntohl(a->s6_addr32[i]) < ntohl(b->s6_addr32[i]); |
| 63 | } |
| 64 | |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | static bool |
| 69 | iprange_mt6(const struct sk_buff *skb, struct xt_action_param *par) |
| 70 | { |
| 71 | const struct xt_iprange_mtinfo *info = par->matchinfo; |
| 72 | const struct ipv6hdr *iph = ipv6_hdr(skb); |
| 73 | bool m; |
| 74 | |
| 75 | if (info->flags & IPRANGE_SRC) { |
| 76 | m = iprange_ipv6_lt(&iph->saddr, &info->src_min.in6); |
| 77 | m |= iprange_ipv6_lt(&info->src_max.in6, &iph->saddr); |
| 78 | m ^= !!(info->flags & IPRANGE_SRC_INV); |
| 79 | if (m) { |
| 80 | pr_debug("src IP %pI6 NOT in range %s%pI6-%pI6\n", |
| 81 | &iph->saddr, |
| 82 | (info->flags & IPRANGE_SRC_INV) ? "(INV) " : "", |
| 83 | &info->src_min.in6, |
| 84 | &info->src_max.in6); |
| 85 | return false; |
| 86 | } |
| 87 | } |
| 88 | if (info->flags & IPRANGE_DST) { |
| 89 | m = iprange_ipv6_lt(&iph->daddr, &info->dst_min.in6); |
| 90 | m |= iprange_ipv6_lt(&info->dst_max.in6, &iph->daddr); |
| 91 | m ^= !!(info->flags & IPRANGE_DST_INV); |
| 92 | if (m) { |
| 93 | pr_debug("dst IP %pI6 NOT in range %s%pI6-%pI6\n", |
| 94 | &iph->daddr, |
| 95 | (info->flags & IPRANGE_DST_INV) ? "(INV) " : "", |
| 96 | &info->dst_min.in6, |
| 97 | &info->dst_max.in6); |
| 98 | return false; |
| 99 | } |
| 100 | } |
| 101 | return true; |
| 102 | } |
| 103 | |
| 104 | static struct xt_match iprange_mt_reg[] __read_mostly = { |
| 105 | { |
| 106 | .name = "iprange", |
| 107 | .revision = 1, |
| 108 | .family = NFPROTO_IPV4, |
| 109 | .match = iprange_mt4, |
| 110 | .matchsize = sizeof(struct xt_iprange_mtinfo), |
| 111 | .me = THIS_MODULE, |
| 112 | }, |
| 113 | { |
| 114 | .name = "iprange", |
| 115 | .revision = 1, |
| 116 | .family = NFPROTO_IPV6, |
| 117 | .match = iprange_mt6, |
| 118 | .matchsize = sizeof(struct xt_iprange_mtinfo), |
| 119 | .me = THIS_MODULE, |
| 120 | }, |
| 121 | }; |
| 122 | |
| 123 | static int __init iprange_mt_init(void) |
| 124 | { |
| 125 | return xt_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg)); |
| 126 | } |
| 127 | |
| 128 | static void __exit iprange_mt_exit(void) |
| 129 | { |
| 130 | xt_unregister_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg)); |
| 131 | } |
| 132 | |
| 133 | module_init(iprange_mt_init); |
| 134 | module_exit(iprange_mt_exit); |
| 135 | MODULE_LICENSE("GPL"); |
| 136 | MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>"); |
| 137 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
| 138 | MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching"); |
| 139 | MODULE_ALIAS("ipt_iprange"); |
| 140 | MODULE_ALIAS("ip6t_iprange"); |