2 * Hop Limit matching module
3 * Maciej Soltysiak <solt@dns.toxicfilms.tv>
4 * Based on HW's ttl module
6 * This software is distributed under the terms GNU GPL
9 #include <linux/module.h>
10 #include <linux/skbuff.h>
12 #include <linux/netfilter_ipv6/ip6t_hl.h>
13 #include <linux/netfilter_ipv6/ip6_tables.h>
15 MODULE_AUTHOR("Maciej Soltysiak <solt@dns.toxicfilms.tv>");
16 MODULE_DESCRIPTION("IP tables Hop Limit matching module");
17 MODULE_LICENSE("GPL");
19 static int match(const struct sk_buff *skb, const struct net_device *in,
20 const struct net_device *out, const void *matchinfo,
21 int offset, const void *hdr, u_int16_t datalen,
24 const struct ip6t_hl_info *info = matchinfo;
25 const struct ipv6hdr *ip6h = skb->nh.ipv6h;
29 return (ip6h->hop_limit == info->hop_limit);
32 return (!(ip6h->hop_limit == info->hop_limit));
35 return (ip6h->hop_limit < info->hop_limit);
38 return (ip6h->hop_limit > info->hop_limit);
41 printk(KERN_WARNING "ip6t_hl: unknown mode %d\n",
49 static int checkentry(const char *tablename, const struct ip6t_ip6 *ip,
50 void *matchinfo, unsigned int matchsize,
51 unsigned int hook_mask)
53 if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_hl_info)))
59 static struct ip6t_match hl_match = { { NULL, NULL }, "hl", &match,
60 &checkentry, NULL, THIS_MODULE };
62 static int __init init(void)
64 return ip6t_register_match(&hl_match);
67 static void __exit fini(void)
69 ip6t_unregister_match(&hl_match);