/* (C) 1999-2001 Paul `Rusty' Russell
   * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
   *
   * 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/types.h>
  #include <linux/netfilter.h>

  #include <linux/slab.h>

  #include <linux/module.h>
  #include <linux/skbuff.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/percpu.h>
  #include <linux/netdevice.h>

  #include <linux/security.h>

  #include <net/net_namespace.h>

  #ifdef CONFIG_SYSCTL
  #include <linux/sysctl.h>
  #endif

  #include <net/netfilter/nf_conntrack.h>

  #include <net/netfilter/nf_conntrack_core.h>

  #include <net/netfilter/nf_conntrack_l3proto.h>

  #include <net/netfilter/nf_conntrack_l4proto.h>

  #include <net/netfilter/nf_conntrack_expect.h>

  #include <net/netfilter/nf_conntrack_helper.h>

  #include <net/netfilter/nf_conntrack_acct.h>

  #include <net/netfilter/nf_conntrack_zones.h>

  #include <net/netfilter/nf_conntrack_timestamp.h>

  #include <linux/rculist_nulls.h>

  MODULE_LICENSE("GPL");

  #ifdef CONFIG_NF_CONNTRACK_PROCFS

  int

  print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,

              const struct nf_conntrack_l3proto *l3proto,
              const struct nf_conntrack_l4proto *l4proto)

  {

  	return l3proto->print_tuple(s, tuple) || l4proto->print_tuple(s, tuple);

  }

  EXPORT_SYMBOL_GPL(print_tuple);

  struct ct_iter_state {

  	struct seq_net_private p;

  	unsigned int bucket;

  	u_int64_t time_now;

  };

  static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)

  {

  	struct net *net = seq_file_net(seq);

  	struct ct_iter_state *st = seq->private;

  	struct hlist_nulls_node *n;

  
  	for (st->bucket = 0;

  	     st->bucket < net->ct.htable_size;

  	     st->bucket++) {

  		n = rcu_dereference(hlist_nulls_first_rcu(&net->ct.hash[st->bucket]));

  		if (!is_a_nulls(n))

  			return n;

  	}
  	return NULL;
  }

  static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
  				      struct hlist_nulls_node *head)

  {

  	struct net *net = seq_file_net(seq);

  	struct ct_iter_state *st = seq->private;

  	head = rcu_dereference(hlist_nulls_next_rcu(head));

  	while (is_a_nulls(head)) {
  		if (likely(get_nulls_value(head) == st->bucket)) {

  			if (++st->bucket >= net->ct.htable_size)

  				return NULL;
  		}

  		head = rcu_dereference(
  				hlist_nulls_first_rcu(
  					&net->ct.hash[st->bucket]));

  	}
  	return head;
  }

  static struct hlist_nulls_node *ct_get_idx(struct seq_file *seq, loff_t pos)

  {

  	struct hlist_nulls_node *head = ct_get_first(seq);

  
  	if (head)
  		while (pos && (head = ct_get_next(seq, head)))
  			pos--;
  	return pos ? NULL : head;
  }
  
  static void *ct_seq_start(struct seq_file *seq, loff_t *pos)

  	__acquires(RCU)

  {

  	struct ct_iter_state *st = seq->private;
  
  	st->time_now = ktime_to_ns(ktime_get_real());

  	rcu_read_lock();

  	return ct_get_idx(seq, *pos);
  }
  
  static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
  {
  	(*pos)++;
  	return ct_get_next(s, v);
  }
  
  static void ct_seq_stop(struct seq_file *s, void *v)

  	__releases(RCU)

  {

  	rcu_read_unlock();

  }

  #ifdef CONFIG_NF_CONNTRACK_SECMARK
  static int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
  {
  	int ret;
  	u32 len;
  	char *secctx;
  
  	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
  	if (ret)

  		return 0;

  
  	ret = seq_printf(s, "secctx=%s ", secctx);
  
  	security_release_secctx(secctx, len);
  	return ret;
  }
  #else
  static inline int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
  {
  	return 0;
  }
  #endif

  #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP

  static int ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)

  {

  	struct ct_iter_state *st = s->private;

  	struct nf_conn_tstamp *tstamp;

  	s64 delta_time;

  
  	tstamp = nf_conn_tstamp_find(ct);
  	if (tstamp) {

  		delta_time = st->time_now - tstamp->start;
  		if (delta_time > 0)
  			delta_time = div_s64(delta_time, NSEC_PER_SEC);
  		else
  			delta_time = 0;
  
  		return seq_printf(s, "delta-time=%llu ",
  				  (unsigned long long)delta_time);

  	}

  	return 0;

  }
  #else
  static inline int
  ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
  {
  	return 0;
  }
  #endif

  /* return 0 on success, 1 in case of error */
  static int ct_seq_show(struct seq_file *s, void *v)
  {

  	struct nf_conntrack_tuple_hash *hash = v;
  	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);

  	const struct nf_conntrack_l3proto *l3proto;
  	const struct nf_conntrack_l4proto *l4proto;

  	int ret = 0;

  	NF_CT_ASSERT(ct);

  	if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
  		return 0;

  
  	/* we only want to print DIR_ORIGINAL */
  	if (NF_CT_DIRECTION(hash))

  		goto release;

  	l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));

  	NF_CT_ASSERT(l3proto);

  	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));

  	NF_CT_ASSERT(l4proto);

  	ret = -ENOSPC;

  	if (seq_printf(s, "%-8s %u %-8s %u %ld ",

  		       l3proto->name, nf_ct_l3num(ct),
  		       l4proto->name, nf_ct_protonum(ct),

  		       timer_pending(&ct->timeout)
  		       ? (long)(ct->timeout.expires - jiffies)/HZ : 0) != 0)

  		goto release;

  	if (l4proto->print_conntrack && l4proto->print_conntrack(s, ct))

  		goto release;

  	if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,

  			l3proto, l4proto))

  		goto release;

  	if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))

  		goto release;

  	if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))

  		if (seq_printf(s, "[UNREPLIED] "))

  			goto release;

  	if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,

  			l3proto, l4proto))

  		goto release;

  	if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))

  		goto release;

  	if (test_bit(IPS_ASSURED_BIT, &ct->status))

  		if (seq_printf(s, "[ASSURED] "))

  			goto release;

  
  #if defined(CONFIG_NF_CONNTRACK_MARK)

  	if (seq_printf(s, "mark=%u ", ct->mark))

  		goto release;

  #endif

  	if (ct_show_secctx(s, ct))

  		goto release;

  #ifdef CONFIG_NF_CONNTRACK_ZONES
  	if (seq_printf(s, "zone=%u ", nf_ct_zone(ct)))
  		goto release;
  #endif

  	if (ct_show_delta_time(s, ct))
  		goto release;

  	if (seq_printf(s, "use=%u
  ", atomic_read(&ct->ct_general.use)))

  		goto release;

  	ret = 0;
  release:
  	nf_ct_put(ct);

  	return ret;

  }

  static const struct seq_operations ct_seq_ops = {

  	.start = ct_seq_start,
  	.next  = ct_seq_next,
  	.stop  = ct_seq_stop,
  	.show  = ct_seq_show
  };
  
  static int ct_open(struct inode *inode, struct file *file)
  {

  	return seq_open_net(inode, file, &ct_seq_ops,

  			sizeof(struct ct_iter_state));

  }

  static const struct file_operations ct_file_ops = {

  	.owner   = THIS_MODULE,
  	.open    = ct_open,
  	.read    = seq_read,
  	.llseek  = seq_lseek,

  	.release = seq_release_net,

  };

  static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
  {

  	struct net *net = seq_file_net(seq);

  	int cpu;
  
  	if (*pos == 0)
  		return SEQ_START_TOKEN;

  	for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {

  		if (!cpu_possible(cpu))
  			continue;
  		*pos = cpu + 1;

  		return per_cpu_ptr(net->ct.stat, cpu);

  	}
  
  	return NULL;
  }
  
  static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  {

  	struct net *net = seq_file_net(seq);

  	int cpu;

  	for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {

  		if (!cpu_possible(cpu))
  			continue;
  		*pos = cpu + 1;

  		return per_cpu_ptr(net->ct.stat, cpu);

  	}
  
  	return NULL;
  }
  
  static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
  {
  }
  
  static int ct_cpu_seq_show(struct seq_file *seq, void *v)
  {

  	struct net *net = seq_file_net(seq);
  	unsigned int nr_conntracks = atomic_read(&net->ct.count);

  	const struct ip_conntrack_stat *st = v;

  
  	if (v == SEQ_START_TOKEN) {

  		seq_printf(seq, "entries  searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error  expect_new expect_create expect_delete search_restart
  ");

  		return 0;
  	}
  
  	seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "

  			"%08x %08x %08x %08x %08x  %08x %08x %08x %08x
  ",

  		   nr_conntracks,
  		   st->searched,
  		   st->found,
  		   st->new,
  		   st->invalid,
  		   st->ignore,
  		   st->delete,
  		   st->delete_list,
  		   st->insert,
  		   st->insert_failed,
  		   st->drop,
  		   st->early_drop,
  		   st->error,
  
  		   st->expect_new,
  		   st->expect_create,

  		   st->expect_delete,
  		   st->search_restart

  		);
  	return 0;
  }

  static const struct seq_operations ct_cpu_seq_ops = {

  	.start	= ct_cpu_seq_start,
  	.next	= ct_cpu_seq_next,
  	.stop	= ct_cpu_seq_stop,
  	.show	= ct_cpu_seq_show,
  };
  
  static int ct_cpu_seq_open(struct inode *inode, struct file *file)
  {

  	return seq_open_net(inode, file, &ct_cpu_seq_ops,
  			    sizeof(struct seq_net_private));

  }

  static const struct file_operations ct_cpu_seq_fops = {

  	.owner	 = THIS_MODULE,
  	.open	 = ct_cpu_seq_open,
  	.read	 = seq_read,
  	.llseek	 = seq_lseek,

  	.release = seq_release_net,

  };

  static int nf_conntrack_standalone_init_proc(struct net *net)

  {
  	struct proc_dir_entry *pde;

  	pde = proc_net_fops_create(net, "nf_conntrack", 0440, &ct_file_ops);

  	if (!pde)
  		goto out_nf_conntrack;

  	pde = proc_create("nf_conntrack", S_IRUGO, net->proc_net_stat,

  			  &ct_cpu_seq_fops);

  	if (!pde)
  		goto out_stat_nf_conntrack;

  	return 0;
  
  out_stat_nf_conntrack:

  	proc_net_remove(net, "nf_conntrack");

  out_nf_conntrack:
  	return -ENOMEM;
  }

  static void nf_conntrack_standalone_fini_proc(struct net *net)

  {

  	remove_proc_entry("nf_conntrack", net->proc_net_stat);
  	proc_net_remove(net, "nf_conntrack");

  }
  #else

  static int nf_conntrack_standalone_init_proc(struct net *net)

  {
  	return 0;
  }

  static void nf_conntrack_standalone_fini_proc(struct net *net)

  {
  }

  #endif /* CONFIG_NF_CONNTRACK_PROCFS */

  
  /* Sysctl support */
  
  #ifdef CONFIG_SYSCTL

  /* Log invalid packets of a given protocol */
  static int log_invalid_proto_min = 0;
  static int log_invalid_proto_max = 255;

  static struct ctl_table_header *nf_ct_netfilter_header;

  
  static ctl_table nf_ct_sysctl_table[] = {
  	{

  		.procname	= "nf_conntrack_max",
  		.data		= &nf_conntrack_max,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname	= "nf_conntrack_count",

  		.data		= &init_net.ct.count,

  		.maxlen		= sizeof(int),
  		.mode		= 0444,

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname       = "nf_conntrack_buckets",

  		.data           = &init_net.ct.htable_size,

  		.maxlen         = sizeof(unsigned int),
  		.mode           = 0444,

  		.proc_handler   = proc_dointvec,

  	},
  	{

  		.procname	= "nf_conntrack_checksum",

  		.data		= &init_net.ct.sysctl_checksum,

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

  		.proc_handler	= proc_dointvec,

  	},
  	{

  		.procname	= "nf_conntrack_log_invalid",

  		.data		= &init_net.ct.sysctl_log_invalid,

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

  		.proc_handler	= proc_dointvec_minmax,

  		.extra1		= &log_invalid_proto_min,
  		.extra2		= &log_invalid_proto_max,
  	},

  	{

  		.procname	= "nf_conntrack_expect_max",
  		.data		= &nf_ct_expect_max,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},

  	{ }

  };
  
  #define NET_NF_CONNTRACK_MAX 2089
  
  static ctl_table nf_ct_netfilter_table[] = {
  	{

  		.procname	= "nf_conntrack_max",
  		.data		= &nf_conntrack_max,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,

  		.proc_handler	= proc_dointvec,

  	},

  	{ }

  };

  static struct ctl_path nf_ct_path[] = {

  	{ .procname = "net", },

  	{ }

  };

  static int nf_conntrack_standalone_init_sysctl(struct net *net)

  {

  	struct ctl_table *table;
  
  	if (net_eq(net, &init_net)) {
  		nf_ct_netfilter_header =
  		       register_sysctl_paths(nf_ct_path, nf_ct_netfilter_table);
  		if (!nf_ct_netfilter_header)
  			goto out;
  	}
  
  	table = kmemdup(nf_ct_sysctl_table, sizeof(nf_ct_sysctl_table),
  			GFP_KERNEL);
  	if (!table)
  		goto out_kmemdup;
  
  	table[1].data = &net->ct.count;

  	table[2].data = &net->ct.htable_size;

  	table[3].data = &net->ct.sysctl_checksum;

  	table[4].data = &net->ct.sysctl_log_invalid;

  
  	net->ct.sysctl_header = register_net_sysctl_table(net,
  					nf_net_netfilter_sysctl_path, table);
  	if (!net->ct.sysctl_header)

  		goto out_unregister_netfilter;

  	return 0;

  out_unregister_netfilter:

  	kfree(table);
  out_kmemdup:
  	if (net_eq(net, &init_net))
  		unregister_sysctl_table(nf_ct_netfilter_header);

  out:

  	printk(KERN_ERR "nf_conntrack: can't register to sysctl.
  ");

  	return -ENOMEM;

  }

  static void nf_conntrack_standalone_fini_sysctl(struct net *net)

  {

  	struct ctl_table *table;
  
  	if (net_eq(net, &init_net))
  		unregister_sysctl_table(nf_ct_netfilter_header);
  	table = net->ct.sysctl_header->ctl_table_arg;
  	unregister_net_sysctl_table(net->ct.sysctl_header);
  	kfree(table);

  }
  #else

  static int nf_conntrack_standalone_init_sysctl(struct net *net)

  {
  	return 0;
  }

  static void nf_conntrack_standalone_fini_sysctl(struct net *net)

  {
  }

  #endif /* CONFIG_SYSCTL */

  static int nf_conntrack_net_init(struct net *net)
  {

  	int ret;
  
  	ret = nf_conntrack_init(net);
  	if (ret < 0)
  		goto out_init;
  	ret = nf_conntrack_standalone_init_proc(net);
  	if (ret < 0)
  		goto out_proc;

  	net->ct.sysctl_checksum = 1;

  	net->ct.sysctl_log_invalid = 0;

  	ret = nf_conntrack_standalone_init_sysctl(net);
  	if (ret < 0)
  		goto out_sysctl;

  	return 0;

  out_sysctl:
  	nf_conntrack_standalone_fini_proc(net);

  out_proc:
  	nf_conntrack_cleanup(net);
  out_init:
  	return ret;

  }
  
  static void nf_conntrack_net_exit(struct net *net)
  {

  	nf_conntrack_standalone_fini_sysctl(net);

  	nf_conntrack_standalone_fini_proc(net);

  	nf_conntrack_cleanup(net);
  }
  
  static struct pernet_operations nf_conntrack_net_ops = {
  	.init = nf_conntrack_net_init,
  	.exit = nf_conntrack_net_exit,
  };

  static int __init nf_conntrack_standalone_init(void)

  {

  	return register_pernet_subsys(&nf_conntrack_net_ops);

  }

  static void __exit nf_conntrack_standalone_fini(void)

  {

  	unregister_pernet_subsys(&nf_conntrack_net_ops);

  }

  module_init(nf_conntrack_standalone_init);
  module_exit(nf_conntrack_standalone_fini);

  
  /* Some modules need us, but don't depend directly on any symbol.
     They should call this. */

  void need_conntrack(void)

  {
  }

  EXPORT_SYMBOL_GPL(need_conntrack);