From mboxrd@z Thu Jan  1 00:00:00 1970
From: John Lister <john.lister@kickstone.co.uk>
Subject: Statistic module nth problem
Date: Thu, 26 Feb 2009 20:49:25 +0000
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I've played with the nth function of the statistic module and i can't 
seem to get it to work, This mirrors a previous post where it matches 
each entry once and then doesn't match any more...

looking at the source code makes me surprised it does this unless i've 
misunderstood completely...


from /net/netfilter/xt_statistic.c

static bool
statistic_mt(const struct sk_buff *skb, const struct net_device *in,
  const struct net_device *out, const struct xt_match *match,
  const void *matchinfo, int offset, unsigned int protoff,
  bool *hotdrop)
{
  struct xt_statistic_info *info = (struct xt_statistic_info *)matchinfo;
  bool ret = info->flags & XT_STATISTIC_INVERT;

  switch (info->mode) {
    case XT_STATISTIC_MODE_RANDOM:
    if ((net_random() & 0x7FFFFFFF) < info->u.random.probability)
      ret = !ret;
      break;
    case XT_STATISTIC_MODE_NTH:
      info = info->master;
      spin_lock_bh(&nth_lock);
      if (info->u.nth.count++ == info->u.nth.every) {
        info->u.nth.count = 0;
        ret = !ret;
      }
      spin_unlock_bh(&nth_lock);
      break;
    }

  return ret;
}


The second case should look like this - or have i missed something?
    case XT_STATISTIC_MODE_NTH:
      info = info->master;
      spin_lock_bh(&nth_lock);
      if (info->u.nth.count == info->u.nth.packet) {
        ret=!ret;
      }
      if (info->u.nth.count++ == info->u.nth.every) {
        info->u.nth.count = 0;
      }
      spin_unlock_bh(&nth_lock);
      break;


I'll submit a patch if anyone agrees and i'll also add stuff to handle 
multiple counts - why was this removed????

Thanks