/* Accouting handling for netfilter. */
  
  /*
   * (C) 2008 Krzysztof Piotr Oledzki <ole@ans.pl>
   *
   * 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/netfilter.h>

  #include <linux/slab.h>

  #include <linux/kernel.h>
  #include <linux/moduleparam.h>

  #include <linux/export.h>

  
  #include <net/netfilter/nf_conntrack.h>
  #include <net/netfilter/nf_conntrack_extend.h>
  #include <net/netfilter/nf_conntrack_acct.h>

  static bool nf_ct_acct __read_mostly;

  
  module_param_named(acct, nf_ct_acct, bool, 0644);
  MODULE_PARM_DESC(acct, "Enable connection tracking flow accounting.");
  
  #ifdef CONFIG_SYSCTL

  static struct ctl_table acct_sysctl_table[] = {
  	{

  		.procname	= "nf_conntrack_acct",

  		.data		= &init_net.ct.sysctl_acct,

  		.maxlen		= sizeof(unsigned int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},
  	{}
  };
  #endif /* CONFIG_SYSCTL */
  
  unsigned int
  seq_print_acct(struct seq_file *s, const struct nf_conn *ct, int dir)
  {

  	struct nf_conn_acct *acct;
  	struct nf_conn_counter *counter;

  
  	acct = nf_conn_acct_find(ct);
  	if (!acct)
  		return 0;

  	counter = acct->counter;

  	return seq_printf(s, "packets=%llu bytes=%llu ",

  			  (unsigned long long)atomic64_read(&counter[dir].packets),
  			  (unsigned long long)atomic64_read(&counter[dir].bytes));

  };
  EXPORT_SYMBOL_GPL(seq_print_acct);
  
  static struct nf_ct_ext_type acct_extend __read_mostly = {

  	.len	= sizeof(struct nf_conn_acct),
  	.align	= __alignof__(struct nf_conn_acct),

  	.id	= NF_CT_EXT_ACCT,
  };

  #ifdef CONFIG_SYSCTL
  static int nf_conntrack_acct_init_sysctl(struct net *net)

  {

  	struct ctl_table *table;

  	table = kmemdup(acct_sysctl_table, sizeof(acct_sysctl_table),
  			GFP_KERNEL);
  	if (!table)
  		goto out;
  
  	table[0].data = &net->ct.sysctl_acct;

  	/* Don't export sysctls to unprivileged users */
  	if (net->user_ns != &init_user_ns)
  		table[0].procname = NULL;

  	net->ct.acct_sysctl_header = register_net_sysctl(net, "net/netfilter",
  							 table);

  	if (!net->ct.acct_sysctl_header) {
  		printk(KERN_ERR "nf_conntrack_acct: can't register to sysctl.
  ");
  		goto out_register;

  	}

  	return 0;

  out_register:
  	kfree(table);
  out:
  	return -ENOMEM;
  }

  static void nf_conntrack_acct_fini_sysctl(struct net *net)
  {
  	struct ctl_table *table;

  	table = net->ct.acct_sysctl_header->ctl_table_arg;
  	unregister_net_sysctl_table(net->ct.acct_sysctl_header);
  	kfree(table);
  }
  #else
  static int nf_conntrack_acct_init_sysctl(struct net *net)
  {
  	return 0;
  }
  
  static void nf_conntrack_acct_fini_sysctl(struct net *net)
  {
  }
  #endif

  int nf_conntrack_acct_pernet_init(struct net *net)

  {

  	net->ct.sysctl_acct = nf_ct_acct;

  	return nf_conntrack_acct_init_sysctl(net);
  }

  void nf_conntrack_acct_pernet_fini(struct net *net)
  {
  	nf_conntrack_acct_fini_sysctl(net);
  }

  int nf_conntrack_acct_init(void)
  {
  	int ret = nf_ct_extend_register(&acct_extend);

  	if (ret < 0)

  		pr_err("nf_conntrack_acct: Unable to register extension
  ");

  	return ret;

  }

  void nf_conntrack_acct_fini(void)

  {

  	nf_ct_extend_unregister(&acct_extend);

  }