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/*
* 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.
*/
#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>
#include <linux/netfilter_ipv4/ipt_iprange.h>
static bool
iprange_mt_v0(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct xt_match *match,
const void *matchinfo, int offset, unsigned int protoff,
bool *hotdrop)
{
const struct ipt_iprange_info *info = matchinfo;
const struct iphdr *iph = ip_hdr(skb);
if (info->flags & IPRANGE_SRC) {
if ((ntohl(iph->saddr) < ntohl(info->src.min_ip)
|| ntohl(iph->saddr) > ntohl(info->src.max_ip))
^ !!(info->flags & IPRANGE_SRC_INV)) {
pr_debug("src IP %u.%u.%u.%u NOT in range %s"
"%u.%u.%u.%u-%u.%u.%u.%u\n",
NIPQUAD(iph->saddr),
info->flags & IPRANGE_SRC_INV ? "(INV) " : "",
NIPQUAD(info->src.min_ip),
NIPQUAD(info->src.max_ip));
return false;
}
}
if (info->flags & IPRANGE_DST) {
if ((ntohl(iph->daddr) < ntohl(info->dst.min_ip)
|| ntohl(iph->daddr) > ntohl(info->dst.max_ip))
^ !!(info->flags & IPRANGE_DST_INV)) {
pr_debug("dst IP %u.%u.%u.%u NOT in range %s"
"%u.%u.%u.%u-%u.%u.%u.%u\n",
NIPQUAD(iph->daddr),
info->flags & IPRANGE_DST_INV ? "(INV) " : "",
NIPQUAD(info->dst.min_ip),
NIPQUAD(info->dst.max_ip));
return false;
}
}
return true;
}
static bool
iprange_mt4(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct xt_match *match,
const void *matchinfo, int offset, unsigned int protoff,
bool *hotdrop)
{
const struct xt_iprange_mtinfo *info = 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 " NIPQUAD_FMT " NOT in range %s"
NIPQUAD_FMT "-" NIPQUAD_FMT "\n",
NIPQUAD(iph->saddr),
(info->flags & IPRANGE_SRC_INV) ? "(INV) " : "",
NIPQUAD(info->src_max.ip),
NIPQUAD(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 " NIPQUAD_FMT " NOT in range %s"
NIPQUAD_FMT "-" NIPQUAD_FMT "\n",
NIPQUAD(iph->daddr),
(info->flags & IPRANGE_DST_INV) ? "(INV) " : "",
NIPQUAD(info->dst_min.ip),
NIPQUAD(info->dst_max.ip));
return false;
}
}
return true;
}
static inline int
iprange_ipv6_sub(const struct in6_addr *a, const struct in6_addr *b)
{
unsigned int i;
int r;
for (i = 0; i < 4; ++i) {
r = ntohl(a->s6_addr32[i]) - ntohl(b->s6_addr32[i]);
if (r != 0)
return r;
}
return 0;
}
static bool
iprange_mt6(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct xt_match *match,
const void *matchinfo, int offset, unsigned int protoff,
bool *hotdrop)
{
const struct xt_iprange_mtinfo *info = matchinfo;
const struct ipv6hdr *iph = ipv6_hdr(skb);
bool m;
if (info->flags & IPRANGE_SRC) {
m = iprange_ipv6_sub(&iph->saddr, &info->src_min.in6) < 0;
m |= iprange_ipv6_sub(&iph->saddr, &info->src_max.in6) > 0;
m ^= info->flags & IPRANGE_SRC_INV;
if (m)
return false;
}
if (info->flags & IPRANGE_DST) {
m = iprange_ipv6_sub(&iph->daddr, &info->dst_min.in6) < 0;
m |= iprange_ipv6_sub(&iph->daddr, &info->dst_max.in6) > 0;
m ^= info->flags & IPRANGE_DST_INV;
if (m)
return false;
}
return true;
}
static struct xt_match iprange_mt_reg[] __read_mostly = {
{
.name = "iprange",
.revision = 0,
.family = AF_INET,
.match = iprange_mt_v0,
.matchsize = sizeof(struct ipt_iprange_info),
.me = THIS_MODULE,
},
{
.name = "iprange",
.revision = 1,
.family = AF_INET,
.match = iprange_mt4,
.matchsize = sizeof(struct xt_iprange_mtinfo),
.me = THIS_MODULE,
},
{
.name = "iprange",
.revision = 1,
.family = AF_INET6,
.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>, Jan Engelhardt <jengelh@computergmbh.de>");
MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching");
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