diff options
Diffstat (limited to 'net/netfilter/xt_iprange.c')
| -rw-r--r-- | net/netfilter/xt_iprange.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/net/netfilter/xt_iprange.c b/net/netfilter/xt_iprange.c new file mode 100644 index 00000000..b46626cd --- /dev/null +++ b/net/netfilter/xt_iprange.c @@ -0,0 +1,140 @@ +/* + * xt_iprange - Netfilter module to match IP address ranges + * + * (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> + * (C) CC Computer Consultants GmbH, 2008 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter/xt_iprange.h> + +static bool +iprange_mt4(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct xt_iprange_mtinfo *info = par->matchinfo; + const struct iphdr *iph = ip_hdr(skb); + bool m; + + if (info->flags & IPRANGE_SRC) { + m = ntohl(iph->saddr) < ntohl(info->src_min.ip); + m |= ntohl(iph->saddr) > ntohl(info->src_max.ip); + m ^= !!(info->flags & IPRANGE_SRC_INV); + if (m) { + pr_debug("src IP %pI4 NOT in range %s%pI4-%pI4\n", + &iph->saddr, + (info->flags & IPRANGE_SRC_INV) ? "(INV) " : "", + &info->src_min.ip, + &info->src_max.ip); + return false; + } + } + if (info->flags & IPRANGE_DST) { + m = ntohl(iph->daddr) < ntohl(info->dst_min.ip); + m |= ntohl(iph->daddr) > ntohl(info->dst_max.ip); + m ^= !!(info->flags & IPRANGE_DST_INV); + if (m) { + pr_debug("dst IP %pI4 NOT in range %s%pI4-%pI4\n", + &iph->daddr, + (info->flags & IPRANGE_DST_INV) ? "(INV) " : "", + &info->dst_min.ip, + &info->dst_max.ip); + return false; + } + } + return true; +} + +static inline int +iprange_ipv6_lt(const struct in6_addr *a, const struct in6_addr *b) +{ + unsigned int i; + + for (i = 0; i < 4; ++i) { + if (a->s6_addr32[i] != b->s6_addr32[i]) + return ntohl(a->s6_addr32[i]) < ntohl(b->s6_addr32[i]); + } + + return 0; +} + +static bool +iprange_mt6(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct xt_iprange_mtinfo *info = par->matchinfo; + const struct ipv6hdr *iph = ipv6_hdr(skb); + bool m; + + if (info->flags & IPRANGE_SRC) { + m = iprange_ipv6_lt(&iph->saddr, &info->src_min.in6); + m |= iprange_ipv6_lt(&info->src_max.in6, &iph->saddr); + m ^= !!(info->flags & IPRANGE_SRC_INV); + if (m) { + pr_debug("src IP %pI6 NOT in range %s%pI6-%pI6\n", + &iph->saddr, + (info->flags & IPRANGE_SRC_INV) ? "(INV) " : "", + &info->src_min.in6, + &info->src_max.in6); + return false; + } + } + if (info->flags & IPRANGE_DST) { + m = iprange_ipv6_lt(&iph->daddr, &info->dst_min.in6); + m |= iprange_ipv6_lt(&info->dst_max.in6, &iph->daddr); + m ^= !!(info->flags & IPRANGE_DST_INV); + if (m) { + pr_debug("dst IP %pI6 NOT in range %s%pI6-%pI6\n", + &iph->daddr, + (info->flags & IPRANGE_DST_INV) ? "(INV) " : "", + &info->dst_min.in6, + &info->dst_max.in6); + return false; + } + } + return true; +} + +static struct xt_match iprange_mt_reg[] __read_mostly = { + { + .name = "iprange", + .revision = 1, + .family = NFPROTO_IPV4, + .match = iprange_mt4, + .matchsize = sizeof(struct xt_iprange_mtinfo), + .me = THIS_MODULE, + }, + { + .name = "iprange", + .revision = 1, + .family = NFPROTO_IPV6, + .match = iprange_mt6, + .matchsize = sizeof(struct xt_iprange_mtinfo), + .me = THIS_MODULE, + }, +}; + +static int __init iprange_mt_init(void) +{ + return xt_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg)); +} + +static void __exit iprange_mt_exit(void) +{ + xt_unregister_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg)); +} + +module_init(iprange_mt_init); +module_exit(iprange_mt_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>"); +MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); +MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching"); +MODULE_ALIAS("ipt_iprange"); +MODULE_ALIAS("ip6t_iprange"); |