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net/netfilter/xt_hl.c
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cfac5ef7b netfilter: Combin... |
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/* * IP tables module for matching the value of the TTL * (C) 2000,2001 by Harald Welte <laforge@netfilter.org> * * Hop Limit matching module * (C) 2001-2002 Maciej Soltysiak <solt@dns.toxicfilms.tv> * * 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/ip.h> #include <linux/ipv6.h> #include <linux/module.h> #include <linux/skbuff.h> #include <linux/netfilter/x_tables.h> #include <linux/netfilter_ipv4/ipt_ttl.h> #include <linux/netfilter_ipv6/ip6t_hl.h> MODULE_AUTHOR("Maciej Soltysiak <solt@dns.toxicfilms.tv>"); MODULE_DESCRIPTION("Xtables: Hoplimit/TTL field match"); MODULE_LICENSE("GPL"); MODULE_ALIAS("ipt_ttl"); MODULE_ALIAS("ip6t_hl"); static bool ttl_mt(const struct sk_buff *skb, const struct xt_match_param *par) { const struct ipt_ttl_info *info = par->matchinfo; const u8 ttl = ip_hdr(skb)->ttl; switch (info->mode) { case IPT_TTL_EQ: return ttl == info->ttl; case IPT_TTL_NE: return ttl != info->ttl; case IPT_TTL_LT: return ttl < info->ttl; case IPT_TTL_GT: return ttl > info->ttl; default: printk(KERN_WARNING "ipt_ttl: unknown mode %d ", info->mode); return false; } return false; } static bool hl_mt6(const struct sk_buff *skb, const struct xt_match_param *par) { const struct ip6t_hl_info *info = par->matchinfo; const struct ipv6hdr *ip6h = ipv6_hdr(skb); switch (info->mode) { case IP6T_HL_EQ: return ip6h->hop_limit == info->hop_limit; break; case IP6T_HL_NE: return ip6h->hop_limit != info->hop_limit; break; case IP6T_HL_LT: return ip6h->hop_limit < info->hop_limit; break; case IP6T_HL_GT: return ip6h->hop_limit > info->hop_limit; break; default: printk(KERN_WARNING "ip6t_hl: unknown mode %d ", info->mode); return false; } return false; } static struct xt_match hl_mt_reg[] __read_mostly = { { .name = "ttl", .revision = 0, .family = NFPROTO_IPV4, .match = ttl_mt, .matchsize = sizeof(struct ipt_ttl_info), .me = THIS_MODULE, }, { .name = "hl", .revision = 0, .family = NFPROTO_IPV6, .match = hl_mt6, .matchsize = sizeof(struct ip6t_hl_info), .me = THIS_MODULE, }, }; static int __init hl_mt_init(void) { return xt_register_matches(hl_mt_reg, ARRAY_SIZE(hl_mt_reg)); } static void __exit hl_mt_exit(void) { xt_unregister_matches(hl_mt_reg, ARRAY_SIZE(hl_mt_reg)); } module_init(hl_mt_init); module_exit(hl_mt_exit); |