| 1 | |
| 2 | |
| 3 | * xt_iprange - Netfilter module to match IP address ranges
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| 4 | *
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| 5 | * (C) 2003 Jozsef Kadlecsik <[email protected]>
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| 6 | * (C) CC Computer Consultants GmbH, 2008
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| 7 |
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| 8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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| 9 | #include <linux/module.h>
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| 10 | #include <linux/skbuff.h>
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| 11 | #include <linux/ip.h>
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| 12 | #include <linux/ipv6.h>
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| 13 | #include <linux/netfilter/x_tables.h>
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| 14 | #include <linux/netfilter/xt_iprange.h>
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| 15 |
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| 16 | static bool
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| 17 | iprange_mt4(const struct sk_buff *skb, struct xt_action_param *par)
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| 18 | {
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| 19 | const struct xt_iprange_mtinfo *info = par->matchinfo;
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| 20 | const struct iphdr *iph = ip_hdr(skb);
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| 21 | bool m;
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| 22 |
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| 23 | if (info->flags & IPRANGE_SRC) {
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| 24 | m = ntohl(iph->saddr) < ntohl(info->src_min.ip);
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| 25 | m |= ntohl(iph->saddr) > ntohl(info->src_max.ip);
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| 26 | m ^= !!(info->flags & IPRANGE_SRC_INV);
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| 27 | if (m)
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| 28 | return false;
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| 29 | }
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| 30 | if (info->flags & IPRANGE_DST) {
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| 31 | m = ntohl(iph->daddr) < ntohl(info->dst_min.ip);
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| 32 | m |= ntohl(iph->daddr) > ntohl(info->dst_max.ip);
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| 33 | m ^= !!(info->flags & IPRANGE_DST_INV);
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| 34 | if (m)
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| 35 | return false;
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| 36 | }
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| 37 | return true;
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| 38 | }
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| 39 |
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| 40 | static inline int
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| 41 | iprange_ipv6_lt(const struct in6_addr *a, const struct in6_addr *b)
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| 42 | {
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| 43 | unsigned int i;
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| 44 |
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| 45 | for (i = 0; i < 4; ++i) {
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| 46 | if (a->s6_addr32[i] != b->s6_addr32[i])
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| 47 | return ntohl(a->s6_addr32[i]) < ntohl(b->s6_addr32[i]);
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| 48 | }
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| 49 |
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| 50 | return 0;
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| 51 | }
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| 52 |
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| 53 | static bool
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| 54 | iprange_mt6(const struct sk_buff *skb, struct xt_action_param *par)
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| 55 | {
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| 56 | const struct xt_iprange_mtinfo *info = par->matchinfo;
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| 57 | const struct ipv6hdr *iph = ipv6_hdr(skb);
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| 58 | bool m;
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| 59 |
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| 60 | if (info->flags & IPRANGE_SRC) {
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| 61 | m = iprange_ipv6_lt(&iph->saddr, &info->src_min.in6);
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| 62 | m |= iprange_ipv6_lt(&info->src_max.in6, &iph->saddr);
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| 63 | m ^= !!(info->flags & IPRANGE_SRC_INV);
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| 64 | if (m)
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| 65 | return false;
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| 66 | }
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| 67 | if (info->flags & IPRANGE_DST) {
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| 68 | m = iprange_ipv6_lt(&iph->daddr, &info->dst_min.in6);
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| 69 | m |= iprange_ipv6_lt(&info->dst_max.in6, &iph->daddr);
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| 70 | m ^= !!(info->flags & IPRANGE_DST_INV);
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| 71 | if (m)
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| 72 | return false;
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| 73 | }
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| 74 | return true;
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| 75 | }
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| 76 |
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| 77 | static struct xt_match iprange_mt_reg[] __read_mostly = {
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| 78 | {
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| 79 | .name = "iprange",
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| 80 | .revision = 1,
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| 81 | .family = NFPROTO_IPV4,
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| 82 | .match = iprange_mt4,
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| 83 | .matchsize = sizeof(struct xt_iprange_mtinfo),
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| 84 | .me = THIS_MODULE,
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| 85 | },
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| 86 | {
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| 87 | .name = "iprange",
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| 88 | .revision = 1,
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| 89 | .family = NFPROTO_IPV6,
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| 90 | .match = iprange_mt6,
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| 91 | .matchsize = sizeof(struct xt_iprange_mtinfo),
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| 92 | .me = THIS_MODULE,
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| 93 | },
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| 94 | };
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| 95 |
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| 96 | static int __init iprange_mt_init(void)
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| 97 | {
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| 98 | return xt_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
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| 99 | }
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| 100 |
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| 101 | static void __exit iprange_mt_exit(void)
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| 102 | {
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| 103 | xt_unregister_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
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| 104 | }
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| 105 |
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| 106 | module_init(iprange_mt_init);
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| 107 | module_exit(iprange_mt_exit);
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| 108 | MODULE_LICENSE("GPL");
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| 109 | MODULE_AUTHOR("Jozsef Kadlecsik <[email protected]>");
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| 110 | MODULE_AUTHOR("Jan Engelhardt <[email protected]>");
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| 111 | MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching");
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| 112 | MODULE_ALIAS("ipt_iprange");
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| 113 | MODULE_ALIAS("ip6t_iprange");
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