diff options
Diffstat (limited to 'net/netfilter/xt_iprange.c')
| -rw-r--r-- | net/netfilter/xt_iprange.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/net/netfilter/xt_iprange.c b/net/netfilter/xt_iprange.c new file mode 100644 index 0000000..7ac54ea --- /dev/null +++ b/net/netfilter/xt_iprange.c @@ -0,0 +1,174 @@ +/* + * 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 xt_match_param *par) +{ + const struct ipt_iprange_info *info = par->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 xt_match_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 " 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 xt_match_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_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 = NFPROTO_IPV4, + .match = iprange_mt_v0, + .matchsize = sizeof(struct ipt_iprange_info), + .me = THIS_MODULE, + }, + { + .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>, Jan Engelhardt <jengelh@computergmbh.de>"); +MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching"); +MODULE_ALIAS("ipt_iprange"); +MODULE_ALIAS("ip6t_iprange"); |
