text: /* (C) 1999-2001 Paul `Rusty' Russell
   * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
   * (C) 2005-2012 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/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
  void
  print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple,
              const struct nf_conntrack_l3proto *l3proto,
              const struct nf_conntrack_l4proto *l4proto)
  {
  	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_get_real_ns();
  	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 void 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;
  
  	seq_printf(s, "secctx=%s ", secctx);
  
  	security_release_secctx(secctx, len);
  }
  #else
  static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
  {
  }
  #endif
  
  #ifdef CONFIG_NF_CONNTRACK_ZONES
  static void ct_show_zone(struct seq_file *s, const struct nf_conn *ct,
  			 int dir)
  {
  	const struct nf_conntrack_zone *zone = nf_ct_zone(ct);
  
  	if (zone->dir != dir)
  		return;
  	switch (zone->dir) {
  	case NF_CT_DEFAULT_ZONE_DIR:
  		seq_printf(s, "zone=%u ", zone->id);
  		break;
  	case NF_CT_ZONE_DIR_ORIG:
  		seq_printf(s, "zone-orig=%u ", zone->id);
  		break;
  	case NF_CT_ZONE_DIR_REPL:
  		seq_printf(s, "zone-reply=%u ", zone->id);
  		break;
  	default:
  		break;
  	}
  }
  #else
  static inline void ct_show_zone(struct seq_file *s, const struct nf_conn *ct,
  				int dir)
  {
  }
  #endif
  
  #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
  static void 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;
  
  		seq_printf(s, "delta-time=%llu ",
  			   (unsigned long long)delta_time);
  	}
  	return;
  }
  #else
  static inline void
  ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
  {
  }
  #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;
  	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);
  
  	if (l4proto->print_conntrack)
  		l4proto->print_conntrack(s, ct);
  
  	print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
  		    l3proto, l4proto);
  
  	ct_show_zone(s, ct, NF_CT_ZONE_DIR_ORIG);
  
  	if (seq_has_overflowed(s))
  		goto release;
  
  	if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))
  		goto release;
  
  	if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
  		seq_printf(s, "[UNREPLIED] ");
  
  	print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
  		    l3proto, l4proto);
  
  	ct_show_zone(s, ct, NF_CT_ZONE_DIR_REPL);
  
  	if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
  		goto release;
  
  	if (test_bit(IPS_ASSURED_BIT, &ct->status))
  		seq_printf(s, "[ASSURED] ");
  
  	if (seq_has_overflowed(s))
  		goto release;
  
  #if defined(CONFIG_NF_CONNTRACK_MARK)
  	seq_printf(s, "mark=%u ", ct->mark);
  #endif
  
  	ct_show_secctx(s, ct);
  	ct_show_zone(s, ct, NF_CT_DEFAULT_ZONE_DIR);
  	ct_show_delta_time(s, ct);
  
  	seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use));
  
  	if (seq_has_overflowed(s))
  		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\n");
  		return 0;
  	}
  
  	seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
  			"%08x %08x %08x %08x %08x  %08x %08x %08x %08x\n",
  		   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;
  	kuid_t root_uid;
  	kgid_t root_gid;
  
  	pde = proc_create("nf_conntrack", 0440, net->proc_net, &ct_file_ops);
  	if (!pde)
  		goto out_nf_conntrack;
  
  	root_uid = make_kuid(net->user_ns, 0);
  	root_gid = make_kgid(net->user_ns, 0);
  	if (uid_valid(root_uid) && gid_valid(root_gid))
  		proc_set_user(pde, root_uid, root_gid);
  
  	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:
  	remove_proc_entry("nf_conntrack", net->proc_net);
  out_nf_conntrack:
  	return -ENOMEM;
  }
  
  static void nf_conntrack_standalone_fini_proc(struct net *net)
  {
  	remove_proc_entry("nf_conntrack", net->proc_net_stat);
  	remove_proc_entry("nf_conntrack", net->proc_net);
  }
  #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 struct 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 struct ctl_table nf_ct_netfilter_table[] = {
  	{
  		.procname	= "nf_conntrack_max",
  		.data		= &nf_conntrack_max,
  		.maxlen		= sizeof(int),
  		.mode		= 0644,
  		.proc_handler	= proc_dointvec,
  	},
  	{ }
  };
  
  static int nf_conntrack_standalone_init_sysctl(struct net *net)
  {
  	struct ctl_table *table;
  
  	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;
  
  	/* Don't export sysctls to unprivileged users */
  	if (net->user_ns != &init_user_ns)
  		table[0].procname = NULL;
  
  	net->ct.sysctl_header = register_net_sysctl(net, "net/netfilter", table);
  	if (!net->ct.sysctl_header)
  		goto out_unregister_netfilter;
  
  	return 0;
  
  out_unregister_netfilter:
  	kfree(table);
  out_kmemdup:
  	return -ENOMEM;
  }
  
  static void nf_conntrack_standalone_fini_sysctl(struct net *net)
  {
  	struct ctl_table *table;
  
  	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_pernet_init(struct net *net)
  {
  	int ret;
  
  	ret = nf_conntrack_init_net(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(net);
  out_init:
  	return ret;
  }
  
  static void nf_conntrack_pernet_exit(struct list_head *net_exit_list)
  {
  	struct net *net;
  
  	list_for_each_entry(net, net_exit_list, exit_list) {
  		nf_conntrack_standalone_fini_sysctl(net);
  		nf_conntrack_standalone_fini_proc(net);
  	}
  	nf_conntrack_cleanup_net_list(net_exit_list);
  }
  
  static struct pernet_operations nf_conntrack_net_ops = {
  	.init		= nf_conntrack_pernet_init,
  	.exit_batch	= nf_conntrack_pernet_exit,
  };
  
  static int __init nf_conntrack_standalone_init(void)
  {
  	int ret = nf_conntrack_init_start();
  	if (ret < 0)
  		goto out_start;
  
  #ifdef CONFIG_SYSCTL
  	nf_ct_netfilter_header =
  		register_net_sysctl(&init_net, "net", nf_ct_netfilter_table);
  	if (!nf_ct_netfilter_header) {
  		pr_err("nf_conntrack: can't register to sysctl.\n");
  		ret = -ENOMEM;
  		goto out_sysctl;
  	}
  #endif
  
  	ret = register_pernet_subsys(&nf_conntrack_net_ops);
  	if (ret < 0)
  		goto out_pernet;
  
  	nf_conntrack_init_end();
  	return 0;
  
  out_pernet:
  #ifdef CONFIG_SYSCTL
  	unregister_net_sysctl_table(nf_ct_netfilter_header);
  out_sysctl:
  #endif
  	nf_conntrack_cleanup_end();
  out_start:
  	return ret;
  }
  
  static void __exit nf_conntrack_standalone_fini(void)
  {
  	nf_conntrack_cleanup_start();
  	unregister_pernet_subsys(&nf_conntrack_net_ops);
  #ifdef CONFIG_SYSCTL
  	unregister_net_sysctl_table(nf_ct_netfilter_header);
  #endif
  	nf_conntrack_cleanup_end();
  }
  
  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);
  