/*
   * (C) 2007 Patrick McHardy <kaber@trash.net>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #include <linux/module.h>
  #include <linux/skbuff.h>
  #include <linux/gen_stats.h>
  
  #include <linux/netfilter/x_tables.h>
  #include <linux/netfilter/xt_rateest.h>
  #include <net/netfilter/xt_rateest.h>

  static bool

  xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)

  {

  	const struct xt_rateest_match_info *info = par->matchinfo;

  	struct gnet_stats_rate_est *r;
  	u_int32_t bps1, bps2, pps1, pps2;
  	bool ret = true;
  
  	spin_lock_bh(&info->est1->lock);
  	r = &info->est1->rstats;
  	if (info->flags & XT_RATEEST_MATCH_DELTA) {
  		bps1 = info->bps1 >= r->bps ? info->bps1 - r->bps : 0;
  		pps1 = info->pps1 >= r->pps ? info->pps1 - r->pps : 0;
  	} else {
  		bps1 = r->bps;
  		pps1 = r->pps;
  	}
  	spin_unlock_bh(&info->est1->lock);
  
  	if (info->flags & XT_RATEEST_MATCH_ABS) {
  		bps2 = info->bps2;
  		pps2 = info->pps2;
  	} else {
  		spin_lock_bh(&info->est2->lock);
  		r = &info->est2->rstats;
  		if (info->flags & XT_RATEEST_MATCH_DELTA) {
  			bps2 = info->bps2 >= r->bps ? info->bps2 - r->bps : 0;
  			pps2 = info->pps2 >= r->pps ? info->pps2 - r->pps : 0;
  		} else {
  			bps2 = r->bps;
  			pps2 = r->pps;
  		}
  		spin_unlock_bh(&info->est2->lock);
  	}
  
  	switch (info->mode) {
  	case XT_RATEEST_MATCH_LT:
  		if (info->flags & XT_RATEEST_MATCH_BPS)
  			ret &= bps1 < bps2;
  		if (info->flags & XT_RATEEST_MATCH_PPS)
  			ret &= pps1 < pps2;
  		break;
  	case XT_RATEEST_MATCH_GT:
  		if (info->flags & XT_RATEEST_MATCH_BPS)
  			ret &= bps1 > bps2;
  		if (info->flags & XT_RATEEST_MATCH_PPS)
  			ret &= pps1 > pps2;
  		break;
  	case XT_RATEEST_MATCH_EQ:
  		if (info->flags & XT_RATEEST_MATCH_BPS)
  			ret &= bps1 == bps2;
  		if (info->flags & XT_RATEEST_MATCH_PPS)

  			ret &= pps1 == pps2;

  		break;
  	}
  
  	ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
  	return ret;
  }

  static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)

  {

  	struct xt_rateest_match_info *info = par->matchinfo;

  	struct xt_rateest *est1, *est2;

  	int ret = -EINVAL;

  
  	if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
  				     XT_RATEEST_MATCH_REL)) != 1)
  		goto err1;
  
  	if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
  		goto err1;
  
  	switch (info->mode) {
  	case XT_RATEEST_MATCH_EQ:
  	case XT_RATEEST_MATCH_LT:
  	case XT_RATEEST_MATCH_GT:
  		break;
  	default:
  		goto err1;
  	}

  	ret  = -ENOENT;

  	est1 = xt_rateest_lookup(info->name1);
  	if (!est1)
  		goto err1;

  	est2 = NULL;

  	if (info->flags & XT_RATEEST_MATCH_REL) {
  		est2 = xt_rateest_lookup(info->name2);
  		if (!est2)
  			goto err2;

  	}

  
  	info->est1 = est1;
  	info->est2 = est2;

  	return 0;

  
  err2:
  	xt_rateest_put(est1);
  err1:

  	return ret;

  }

  static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)

  {

  	struct xt_rateest_match_info *info = par->matchinfo;

  
  	xt_rateest_put(info->est1);
  	if (info->est2)
  		xt_rateest_put(info->est2);
  }

  static struct xt_match xt_rateest_mt_reg __read_mostly = {
  	.name       = "rateest",
  	.revision   = 0,
  	.family     = NFPROTO_UNSPEC,
  	.match      = xt_rateest_mt,
  	.checkentry = xt_rateest_mt_checkentry,
  	.destroy    = xt_rateest_mt_destroy,
  	.matchsize  = sizeof(struct xt_rateest_match_info),
  	.me         = THIS_MODULE,

  };
  
  static int __init xt_rateest_mt_init(void)
  {

  	return xt_register_match(&xt_rateest_mt_reg);

  }
  
  static void __exit xt_rateest_mt_fini(void)
  {

  	xt_unregister_match(&xt_rateest_mt_reg);

  }
  
  MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("xtables rate estimator match");
  MODULE_ALIAS("ipt_rateest");
  MODULE_ALIAS("ip6t_rateest");
  module_init(xt_rateest_mt_init);
  module_exit(xt_rateest_mt_fini);