2ae15b64e6
Updates the MODULE_DESCRIPTION() tags for all Netfilter modules, actually describing what the module does and not just "netfilter XYZ target". Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
/* IP tables module for matching the value of the TTL
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*
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* (C) 2000,2001 by Harald Welte <laforge@netfilter.org>
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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/ip.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter_ipv4/ipt_ttl.h>
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#include <linux/netfilter/x_tables.h>
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MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
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MODULE_DESCRIPTION("Xtables: IPv4 TTL field match");
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MODULE_LICENSE("GPL");
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static bool
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ttl_mt(const struct sk_buff *skb, const struct net_device *in,
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const struct net_device *out, const struct xt_match *match,
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const void *matchinfo, int offset, unsigned int protoff, bool *hotdrop)
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{
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const struct ipt_ttl_info *info = matchinfo;
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const u8 ttl = ip_hdr(skb)->ttl;
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switch (info->mode) {
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case IPT_TTL_EQ:
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return ttl == info->ttl;
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case IPT_TTL_NE:
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return ttl != info->ttl;
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case IPT_TTL_LT:
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return ttl < info->ttl;
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case IPT_TTL_GT:
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return ttl > info->ttl;
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default:
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printk(KERN_WARNING "ipt_ttl: unknown mode %d\n",
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info->mode);
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return false;
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}
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return false;
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}
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static struct xt_match ttl_mt_reg __read_mostly = {
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.name = "ttl",
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.family = AF_INET,
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.match = ttl_mt,
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.matchsize = sizeof(struct ipt_ttl_info),
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.me = THIS_MODULE,
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};
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static int __init ttl_mt_init(void)
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{
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return xt_register_match(&ttl_mt_reg);
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}
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static void __exit ttl_mt_exit(void)
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{
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xt_unregister_match(&ttl_mt_reg);
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}
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module_init(ttl_mt_init);
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module_exit(ttl_mt_exit);
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