1/* Length Match - IPv6 Port */ 2 3#include <linux/module.h> 4#include <linux/skbuff.h> 5#include <linux/netfilter_ipv6/ip6t_length.h> 6#include <linux/netfilter_ipv6/ip6_tables.h> 7 8static int 9match(const struct sk_buff *skb, 10 const struct net_device *in, 11 const struct net_device *out, 12 const void *matchinfo, 13 int offset, 14 const void *hdr, 15 u_int16_t datalen, 16 int *hotdrop) 17{ 18 const struct ip6t_length_info *info = matchinfo; 19 u_int16_t pktlen = ntohs(skb->nh.ipv6h->payload_len) + sizeof(struct ipv6hdr); 20 21 return (pktlen >= info->min && pktlen <= info->max) ^ info->invert; 22} 23 24static int 25checkentry(const char *tablename, 26 const struct ip6t_ip6 *ip, 27 void *matchinfo, 28 unsigned int matchsize, 29 unsigned int hook_mask) 30{ 31 if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_length_info))) 32 return 0; 33 34 return 1; 35} 36 37static struct ip6t_match length_match 38= { { NULL, NULL }, "length", &match, &checkentry, NULL, THIS_MODULE }; 39 40static int __init init(void) 41{ 42 return ip6t_register_match(&length_match); 43} 44 45static void __exit fini(void) 46{ 47 ip6t_unregister_match(&length_match); 48} 49 50module_init(init); 51module_exit(fini); 52