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![Jan Engelhardt](/assets/img/avatar_default.png)
The function signatures for Xtables extensions have grown over time. It involves a lot of typing/replication, and also a bit of stack space even if they are not used. Realize an NFWS2008 idea and pack them into structs. The skb remains outside of the struct so gcc can continue to apply its optimizations. This patch does this for match extensions' match functions. A few ambiguities have also been addressed. The "offset" parameter for example has been renamed to "fragoff" (there are so many different offsets already) and "protoff" to "thoff" (there is more than just one protocol here, so clarify). Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net>
174 lines
4.8 KiB
C
174 lines
4.8 KiB
C
/*
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* xt_iprange - Netfilter module to match IP address ranges
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*
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* (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
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* (C) CC Computer Consultants GmbH, 2008
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_iprange.h>
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#include <linux/netfilter_ipv4/ipt_iprange.h>
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static bool
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iprange_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
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{
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const struct ipt_iprange_info *info = par->matchinfo;
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const struct iphdr *iph = ip_hdr(skb);
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if (info->flags & IPRANGE_SRC) {
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if ((ntohl(iph->saddr) < ntohl(info->src.min_ip)
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|| ntohl(iph->saddr) > ntohl(info->src.max_ip))
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^ !!(info->flags & IPRANGE_SRC_INV)) {
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pr_debug("src IP %u.%u.%u.%u NOT in range %s"
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"%u.%u.%u.%u-%u.%u.%u.%u\n",
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NIPQUAD(iph->saddr),
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info->flags & IPRANGE_SRC_INV ? "(INV) " : "",
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NIPQUAD(info->src.min_ip),
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NIPQUAD(info->src.max_ip));
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return false;
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}
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}
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if (info->flags & IPRANGE_DST) {
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if ((ntohl(iph->daddr) < ntohl(info->dst.min_ip)
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|| ntohl(iph->daddr) > ntohl(info->dst.max_ip))
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^ !!(info->flags & IPRANGE_DST_INV)) {
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pr_debug("dst IP %u.%u.%u.%u NOT in range %s"
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"%u.%u.%u.%u-%u.%u.%u.%u\n",
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NIPQUAD(iph->daddr),
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info->flags & IPRANGE_DST_INV ? "(INV) " : "",
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NIPQUAD(info->dst.min_ip),
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NIPQUAD(info->dst.max_ip));
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return false;
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}
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}
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return true;
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}
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static bool
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iprange_mt4(const struct sk_buff *skb, const struct xt_match_param *par)
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{
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const struct xt_iprange_mtinfo *info = par->matchinfo;
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const struct iphdr *iph = ip_hdr(skb);
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bool m;
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if (info->flags & IPRANGE_SRC) {
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m = ntohl(iph->saddr) < ntohl(info->src_min.ip);
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m |= ntohl(iph->saddr) > ntohl(info->src_max.ip);
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m ^= info->flags & IPRANGE_SRC_INV;
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if (m) {
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pr_debug("src IP " NIPQUAD_FMT " NOT in range %s"
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NIPQUAD_FMT "-" NIPQUAD_FMT "\n",
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NIPQUAD(iph->saddr),
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(info->flags & IPRANGE_SRC_INV) ? "(INV) " : "",
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NIPQUAD(info->src_max.ip),
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NIPQUAD(info->src_max.ip));
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return false;
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}
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}
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if (info->flags & IPRANGE_DST) {
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m = ntohl(iph->daddr) < ntohl(info->dst_min.ip);
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m |= ntohl(iph->daddr) > ntohl(info->dst_max.ip);
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m ^= info->flags & IPRANGE_DST_INV;
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if (m) {
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pr_debug("dst IP " NIPQUAD_FMT " NOT in range %s"
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NIPQUAD_FMT "-" NIPQUAD_FMT "\n",
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NIPQUAD(iph->daddr),
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(info->flags & IPRANGE_DST_INV) ? "(INV) " : "",
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NIPQUAD(info->dst_min.ip),
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NIPQUAD(info->dst_max.ip));
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return false;
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}
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}
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return true;
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}
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static inline int
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iprange_ipv6_sub(const struct in6_addr *a, const struct in6_addr *b)
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{
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unsigned int i;
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int r;
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for (i = 0; i < 4; ++i) {
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r = ntohl(a->s6_addr32[i]) - ntohl(b->s6_addr32[i]);
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if (r != 0)
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return r;
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}
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return 0;
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}
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static bool
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iprange_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
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{
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const struct xt_iprange_mtinfo *info = par->matchinfo;
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const struct ipv6hdr *iph = ipv6_hdr(skb);
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bool m;
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if (info->flags & IPRANGE_SRC) {
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m = iprange_ipv6_sub(&iph->saddr, &info->src_min.in6) < 0;
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m |= iprange_ipv6_sub(&iph->saddr, &info->src_max.in6) > 0;
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m ^= info->flags & IPRANGE_SRC_INV;
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if (m)
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return false;
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}
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if (info->flags & IPRANGE_DST) {
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m = iprange_ipv6_sub(&iph->daddr, &info->dst_min.in6) < 0;
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m |= iprange_ipv6_sub(&iph->daddr, &info->dst_max.in6) > 0;
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m ^= info->flags & IPRANGE_DST_INV;
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if (m)
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return false;
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}
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return true;
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}
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static struct xt_match iprange_mt_reg[] __read_mostly = {
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{
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.name = "iprange",
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.revision = 0,
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.family = NFPROTO_IPV4,
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.match = iprange_mt_v0,
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.matchsize = sizeof(struct ipt_iprange_info),
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.me = THIS_MODULE,
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},
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{
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.name = "iprange",
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.revision = 1,
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.family = NFPROTO_IPV4,
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.match = iprange_mt4,
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.matchsize = sizeof(struct xt_iprange_mtinfo),
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.me = THIS_MODULE,
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},
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{
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.name = "iprange",
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.revision = 1,
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.family = NFPROTO_IPV6,
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.match = iprange_mt6,
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.matchsize = sizeof(struct xt_iprange_mtinfo),
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.me = THIS_MODULE,
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},
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};
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static int __init iprange_mt_init(void)
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{
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return xt_register_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
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}
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static void __exit iprange_mt_exit(void)
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{
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xt_unregister_matches(iprange_mt_reg, ARRAY_SIZE(iprange_mt_reg));
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}
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module_init(iprange_mt_init);
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module_exit(iprange_mt_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>, Jan Engelhardt <jengelh@computergmbh.de>");
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MODULE_DESCRIPTION("Xtables: arbitrary IPv4 range matching");
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MODULE_ALIAS("ipt_iprange");
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MODULE_ALIAS("ip6t_iprange");
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