release/src/linux/linux/net/ipv4/netfilter/ipt_bcount.c

   1 /*
   2
   3         bcount match (experimental)
   4         Copyright (C) 2006 Jonathan Zarate
   5
   6         Licensed under GNU GPL v2 or later.
   7
   8 */
   9 #include <linux/module.h>
  10 #include <linux/skbuff.h>
  11 #include <net/sock.h>
  12 #include <linux/netfilter_ipv4/ip_tables.h>
  13 #include <linux/netfilter_ipv4/ip_conntrack.h>
  14 #include <linux/netfilter_ipv4/ipt_bcount.h>
  15
  16 //      #define LOG                     printk
  17 #define LOG(...)        do { } while (0);
  18
  19
  20 static int match(const struct sk_buff *skb,     const struct net_device *in, const struct net_device *out,
  21                                  const void *matchinfo, int offset, const void *hdr, u_int16_t datalen, int *hotdrop)
  22 {
  23         const struct ipt_bcount_match *info = matchinfo;
  24         struct ip_conntrack *ct;
  25         enum ip_conntrack_info ctinfo;
  26
  27         ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
  28         if (!ct) return !info->invert;
  29         return ((ct->bcount >= info->min) && (ct->bcount <= info->max)) ^ info->invert;
  30 }
  31
  32 static int checkentry(const char *tablename, const struct ipt_ip *ip, void *matchinfo,
  33                                           unsigned int matchsize, unsigned int hook_mask)
  34 {
  35         return (matchsize == IPT_ALIGN(sizeof(struct ipt_bcount_match)));
  36 }
  37
  38
  39 static struct ipt_match bcount_match
  40 = { { NULL, NULL }, "bcount", &match, &checkentry, NULL, THIS_MODULE };
  41
  42 static int __init init(void)
  43 {
  44         LOG(KERN_INFO "ipt_bcount <" __DATE__ " " __TIME__ "> loaded\n");
  45         return ipt_register_match(&bcount_match);
  46 }
  47
  48 static void __exit fini(void)
  49 {
  50         ipt_unregister_match(&bcount_match);
  51 }
  52
  53 module_init(init);
  54 module_exit(fini);
  55
  56
  57 MODULE_AUTHOR("Jonathan Zarate");
  58 MODULE_DESCRIPTION("bcount match");
  59 MODULE_LICENSE("GPL");