projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* IP tables module for matching the value of the TTL |
| 2 | * | |
| 3 | * ipt_ttl.c,v 1.5 2000/11/13 11:16:08 laforge Exp | |
| 4 | * | |
| 5 | * (C) 2000,2001 by Harald Welte <laforge@netfilter.org> | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License version 2 as | |
| 9 | * published by the Free Software Foundation. | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/module.h> | |
| 13 | #include <linux/skbuff.h> | |
| 14 | ||
| 15 | #include <linux/netfilter_ipv4/ipt_ttl.h> | |
| 16 | #include <linux/netfilter_ipv4/ip_tables.h> | |
| 17 | ||
| 18 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
| 19 | MODULE_DESCRIPTION("IP tables TTL matching module"); | |
| 20 | MODULE_LICENSE("GPL"); | |
| 21 | ||
| c4986734 PM |
22 | static int match(const struct sk_buff *skb, |
| 23 | const struct net_device *in, const struct net_device *out, | |
| 24 | const struct xt_match *match, const void *matchinfo, | |
| 2e4e6a17 | 25 | int offset, unsigned int protoff, int *hotdrop) |
| 1da177e4 LT |
26 | { |
| 27 | const struct ipt_ttl_info *info = matchinfo; | |
| 28 | ||
| 29 | switch (info->mode) { | |
| 30 | case IPT_TTL_EQ: | |
| 31 | return (skb->nh.iph->ttl == info->ttl); | |
| 32 | break; | |
| 33 | case IPT_TTL_NE: | |
| 34 | return (!(skb->nh.iph->ttl == info->ttl)); | |
| 35 | break; | |
| 36 | case IPT_TTL_LT: | |
| 37 | return (skb->nh.iph->ttl < info->ttl); | |
| 38 | break; | |
| 39 | case IPT_TTL_GT: | |
| 40 | return (skb->nh.iph->ttl > info->ttl); | |
| 41 | break; | |
| 42 | default: | |
| 43 | printk(KERN_WARNING "ipt_ttl: unknown mode %d\n", | |
| 44 | info->mode); | |
| 45 | return 0; | |
| 46 | } | |
| 47 | ||
| 48 | return 0; | |
| 49 | } | |
| 50 | ||
| 1da177e4 LT |
51 | static struct ipt_match ttl_match = { |
| 52 | .name = "ttl", | |
| 1d5cd909 PM |
53 | .match = match, |
| 54 | .matchsize = sizeof(struct ipt_ttl_info), | |
| 1da177e4 LT |
55 | .me = THIS_MODULE, |
| 56 | }; | |
| 57 | ||
| 58 | static int __init init(void) | |
| 59 | { | |
| 60 | return ipt_register_match(&ttl_match); | |
| 61 | } | |
| 62 | ||
| 63 | static void __exit fini(void) | |
| 64 | { | |
| 65 | ipt_unregister_match(&ttl_match); | |
| 66 | ||
| 67 | } | |
| 68 | ||
| 69 | module_init(init); | |
| 70 | module_exit(fini); |