| 1 | /* |
| 2 | * iptables module to match IP address ranges |
| 3 | * |
| 4 | * (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/skbuff.h> |
| 12 | #include <linux/ip.h> |
| 13 | #include <linux/netfilter/x_tables.h> |
| 14 | #include <linux/netfilter_ipv4/ipt_iprange.h> |
| 15 | |
| 16 | MODULE_LICENSE("GPL"); |
| 17 | MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>"); |
| 18 | MODULE_DESCRIPTION("iptables arbitrary IP range match module"); |
| 19 | |
| 20 | #if 0 |
| 21 | #define DEBUGP printk |
| 22 | #else |
| 23 | #define DEBUGP(format, args...) |
| 24 | #endif |
| 25 | |
| 26 | static bool |
| 27 | match(const struct sk_buff *skb, |
| 28 | const struct net_device *in, |
| 29 | const struct net_device *out, |
| 30 | const struct xt_match *match, |
| 31 | const void *matchinfo, |
| 32 | int offset, unsigned int protoff, bool *hotdrop) |
| 33 | { |
| 34 | const struct ipt_iprange_info *info = matchinfo; |
| 35 | const struct iphdr *iph = ip_hdr(skb); |
| 36 | |
| 37 | if (info->flags & IPRANGE_SRC) { |
| 38 | if ((ntohl(iph->saddr) < ntohl(info->src.min_ip) |
| 39 | || ntohl(iph->saddr) > ntohl(info->src.max_ip)) |
| 40 | ^ !!(info->flags & IPRANGE_SRC_INV)) { |
| 41 | DEBUGP("src IP %u.%u.%u.%u NOT in range %s" |
| 42 | "%u.%u.%u.%u-%u.%u.%u.%u\n", |
| 43 | NIPQUAD(iph->saddr), |
| 44 | info->flags & IPRANGE_SRC_INV ? "(INV) " : "", |
| 45 | NIPQUAD(info->src.min_ip), |
| 46 | NIPQUAD(info->src.max_ip)); |
| 47 | return false; |
| 48 | } |
| 49 | } |
| 50 | if (info->flags & IPRANGE_DST) { |
| 51 | if ((ntohl(iph->daddr) < ntohl(info->dst.min_ip) |
| 52 | || ntohl(iph->daddr) > ntohl(info->dst.max_ip)) |
| 53 | ^ !!(info->flags & IPRANGE_DST_INV)) { |
| 54 | DEBUGP("dst IP %u.%u.%u.%u NOT in range %s" |
| 55 | "%u.%u.%u.%u-%u.%u.%u.%u\n", |
| 56 | NIPQUAD(iph->daddr), |
| 57 | info->flags & IPRANGE_DST_INV ? "(INV) " : "", |
| 58 | NIPQUAD(info->dst.min_ip), |
| 59 | NIPQUAD(info->dst.max_ip)); |
| 60 | return false; |
| 61 | } |
| 62 | } |
| 63 | return true; |
| 64 | } |
| 65 | |
| 66 | static struct xt_match iprange_match __read_mostly = { |
| 67 | .name = "iprange", |
| 68 | .family = AF_INET, |
| 69 | .match = match, |
| 70 | .matchsize = sizeof(struct ipt_iprange_info), |
| 71 | .me = THIS_MODULE |
| 72 | }; |
| 73 | |
| 74 | static int __init ipt_iprange_init(void) |
| 75 | { |
| 76 | return xt_register_match(&iprange_match); |
| 77 | } |
| 78 | |
| 79 | static void __exit ipt_iprange_fini(void) |
| 80 | { |
| 81 | xt_unregister_match(&iprange_match); |
| 82 | } |
| 83 | |
| 84 | module_init(ipt_iprange_init); |
| 85 | module_exit(ipt_iprange_fini); |