[mirror_ubuntu-artful-kernel.git] / net / netfilter / nf_conntrack_proto.c

/* L3/L4 protocol support for nf_conntrack. */

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
 * (C) 2006-2012 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/module.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/vmalloc.h>
#include <linux/stddef.h>
#include <linux/err.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>

#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_core.h>

static struct nf_conntrack_l4proto __rcu **nf_ct_protos[NFPROTO_NUMPROTO] __read_mostly;
struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[NFPROTO_NUMPROTO] __read_mostly;
EXPORT_SYMBOL_GPL(nf_ct_l3protos);

static DEFINE_MUTEX(nf_ct_proto_mutex);

#ifdef CONFIG_SYSCTL
static int
nf_ct_register_sysctl(struct net *net,
		      struct ctl_table_header **header,
		      const char *path,
		      struct ctl_table *table)
{
	if (*header == NULL) {
		*header = register_net_sysctl(net, path, table);
		if (*header == NULL)
			return -ENOMEM;
	}

	return 0;
}

static void
nf_ct_unregister_sysctl(struct ctl_table_header **header,
			struct ctl_table **table,
			unsigned int users)
{
	if (users > 0)
		return;

	unregister_net_sysctl_table(*header);
	kfree(*table);
	*header = NULL;
	*table = NULL;
}
#endif

struct nf_conntrack_l4proto *
__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
{
	if (unlikely(l3proto >= NFPROTO_NUMPROTO || nf_ct_protos[l3proto] == NULL))
		return &nf_conntrack_l4proto_generic;

	return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
}
EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);

/* this is guaranteed to always return a valid protocol helper, since
 * it falls back to generic_protocol */
struct nf_conntrack_l3proto *
nf_ct_l3proto_find_get(u_int16_t l3proto)
{
	struct nf_conntrack_l3proto *p;

	rcu_read_lock();
	p = __nf_ct_l3proto_find(l3proto);
	if (!try_module_get(p->me))
		p = &nf_conntrack_l3proto_generic;
	rcu_read_unlock();

	return p;
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);

int
nf_ct_l3proto_try_module_get(unsigned short l3proto)
{
	int ret;
	struct nf_conntrack_l3proto *p;

retry:	p = nf_ct_l3proto_find_get(l3proto);
	if (p == &nf_conntrack_l3proto_generic) {
		ret = request_module("nf_conntrack-%d", l3proto);
		if (!ret)
			goto retry;

		return -EPROTOTYPE;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);

void nf_ct_l3proto_module_put(unsigned short l3proto)
{
	struct nf_conntrack_l3proto *p;

	/* rcu_read_lock not necessary since the caller holds a reference, but
	 * taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
	 */
	rcu_read_lock();
	p = __nf_ct_l3proto_find(l3proto);
	module_put(p->me);
	rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);

int nf_ct_netns_get(struct net *net, u8 nfproto)
{
	const struct nf_conntrack_l3proto *l3proto;
	int ret;

	might_sleep();

	ret = nf_ct_l3proto_try_module_get(nfproto);
	if (ret < 0)
		return ret;

	/* we already have a reference, can't fail */
	rcu_read_lock();
	l3proto = __nf_ct_l3proto_find(nfproto);
	rcu_read_unlock();

	if (!l3proto->net_ns_get)
		return 0;

	ret = l3proto->net_ns_get(net);
	if (ret < 0)
		nf_ct_l3proto_module_put(nfproto);

	return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_netns_get);

void nf_ct_netns_put(struct net *net, u8 nfproto)
{
	const struct nf_conntrack_l3proto *l3proto;

	might_sleep();

	/* same as nf_conntrack_netns_get(), reference assumed */
	rcu_read_lock();
	l3proto = __nf_ct_l3proto_find(nfproto);
	rcu_read_unlock();

	if (WARN_ON(!l3proto))
		return;

	if (l3proto->net_ns_put)
		l3proto->net_ns_put(net);

	nf_ct_l3proto_module_put(nfproto);
}
EXPORT_SYMBOL_GPL(nf_ct_netns_put);

struct nf_conntrack_l4proto *
nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
{
	struct nf_conntrack_l4proto *p;

	rcu_read_lock();
	p = __nf_ct_l4proto_find(l3num, l4num);
	if (!try_module_get(p->me))
		p = &nf_conntrack_l4proto_generic;
	rcu_read_unlock();

	return p;
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);

void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
{
	module_put(p->me);
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);

static int kill_l3proto(struct nf_conn *i, void *data)
{
	return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
}

static int kill_l4proto(struct nf_conn *i, void *data)
{
	struct nf_conntrack_l4proto *l4proto;
	l4proto = data;
	return nf_ct_protonum(i) == l4proto->l4proto &&
	       nf_ct_l3num(i) == l4proto->l3proto;
}

int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)
{
	int ret = 0;
	struct nf_conntrack_l3proto *old;

	if (proto->l3proto >= NFPROTO_NUMPROTO)
		return -EBUSY;

	if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
		return -EINVAL;

	mutex_lock(&nf_ct_proto_mutex);
	old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
					lockdep_is_held(&nf_ct_proto_mutex));
	if (old != &nf_conntrack_l3proto_generic) {
		ret = -EBUSY;
		goto out_unlock;
	}

	if (proto->nlattr_tuple_size)
		proto->nla_size = 3 * proto->nlattr_tuple_size();

	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);

out_unlock:
	mutex_unlock(&nf_ct_proto_mutex);
	return ret;

}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);

#ifdef CONFIG_SYSCTL
extern unsigned int nf_conntrack_default_on;

int nf_ct_l3proto_pernet_register(struct net *net,
				  struct nf_conntrack_l3proto *proto)
{
	if (nf_conntrack_default_on == 0)
		return 0;

	return proto->net_ns_get ? proto->net_ns_get(net) : 0;
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register);
#endif

void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto)
{
	BUG_ON(proto->l3proto >= NFPROTO_NUMPROTO);

	mutex_lock(&nf_ct_proto_mutex);
	BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
					 lockdep_is_held(&nf_ct_proto_mutex)
					 ) != proto);
	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
			   &nf_conntrack_l3proto_generic);
	mutex_unlock(&nf_ct_proto_mutex);

	synchronize_rcu();
	/* Remove all contrack entries for this protocol */
	nf_ct_iterate_destroy(kill_l3proto, proto);
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);

void nf_ct_l3proto_pernet_unregister(struct net *net,
				     struct nf_conntrack_l3proto *proto)
{
	/*
	 * nf_conntrack_default_on *might* have registered hooks.
	 * ->net_ns_put must cope with more puts() than get(), i.e.
	 * if nf_conntrack_default_on was 0 at time of
	 * nf_ct_l3proto_pernet_register invocation this net_ns_put()
	 * should be a noop.
	 */
	if (proto->net_ns_put)
		proto->net_ns_put(net);
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister);

static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
					      struct nf_conntrack_l4proto *l4proto)
{
	if (l4proto->get_net_proto) {
		/* statically built-in protocols use static per-net */
		return l4proto->get_net_proto(net);
	} else if (l4proto->net_id) {
		/* ... and loadable protocols use dynamic per-net */
		return net_generic(net, *l4proto->net_id);
	}
	return NULL;
}

static
int nf_ct_l4proto_register_sysctl(struct net *net,
				  struct nf_proto_net *pn,
				  struct nf_conntrack_l4proto *l4proto)
{
	int err = 0;

#ifdef CONFIG_SYSCTL
	if (pn->ctl_table != NULL) {
		err = nf_ct_register_sysctl(net,
					    &pn->ctl_table_header,
					    "net/netfilter",
					    pn->ctl_table);
		if (err < 0) {
			if (!pn->users) {
				kfree(pn->ctl_table);
				pn->ctl_table = NULL;
			}
		}
	}
#endif /* CONFIG_SYSCTL */
	return err;
}

static
void nf_ct_l4proto_unregister_sysctl(struct net *net,
				     struct nf_proto_net *pn,
				     struct nf_conntrack_l4proto *l4proto)
{
#ifdef CONFIG_SYSCTL
	if (pn->ctl_table_header != NULL)
		nf_ct_unregister_sysctl(&pn->ctl_table_header,
					&pn->ctl_table,
					pn->users);
#endif /* CONFIG_SYSCTL */
}

/* FIXME: Allow NULL functions and sub in pointers to generic for
   them. --RR */
int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *l4proto)
{
	int ret = 0;

	if (l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos))
		return -EBUSY;

	if ((l4proto->to_nlattr && !l4proto->nlattr_size) ||
	    (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
		return -EINVAL;

	mutex_lock(&nf_ct_proto_mutex);
	if (!nf_ct_protos[l4proto->l3proto]) {
		/* l3proto may be loaded latter. */
		struct nf_conntrack_l4proto __rcu **proto_array;
		int i;

		proto_array = kmalloc(MAX_NF_CT_PROTO *
				      sizeof(struct nf_conntrack_l4proto *),
				      GFP_KERNEL);
		if (proto_array == NULL) {
			ret = -ENOMEM;
			goto out_unlock;
		}

		for (i = 0; i < MAX_NF_CT_PROTO; i++)
			RCU_INIT_POINTER(proto_array[i],
					 &nf_conntrack_l4proto_generic);

		/* Before making proto_array visible to lockless readers,
		 * we must make sure its content is committed to memory.
		 */
		smp_wmb();

		nf_ct_protos[l4proto->l3proto] = proto_array;
	} else if (rcu_dereference_protected(
			nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
			lockdep_is_held(&nf_ct_proto_mutex)
			) != &nf_conntrack_l4proto_generic) {
		ret = -EBUSY;
		goto out_unlock;
	}

	l4proto->nla_size = 0;
	if (l4proto->nlattr_size)
		l4proto->nla_size += l4proto->nlattr_size();
	if (l4proto->nlattr_tuple_size)
		l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();

	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
			   l4proto);
out_unlock:
	mutex_unlock(&nf_ct_proto_mutex);
	return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_register_one);

int nf_ct_l4proto_pernet_register_one(struct net *net,
				      struct nf_conntrack_l4proto *l4proto)
{
	int ret = 0;
	struct nf_proto_net *pn = NULL;

	if (l4proto->init_net) {
		ret = l4proto->init_net(net, l4proto->l3proto);
		if (ret < 0)
			goto out;
	}

	pn = nf_ct_l4proto_net(net, l4proto);
	if (pn == NULL)
		goto out;

	ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
	if (ret < 0)
		goto out;

	pn->users++;
out:
	return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register_one);

static void __nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)

{
	BUG_ON(l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos));

	BUG_ON(rcu_dereference_protected(
			nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
			lockdep_is_held(&nf_ct_proto_mutex)
			) != l4proto);
	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
			   &nf_conntrack_l4proto_generic);
}

void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
{
	mutex_lock(&nf_ct_proto_mutex);
	__nf_ct_l4proto_unregister_one(l4proto);
	mutex_unlock(&nf_ct_proto_mutex);

	synchronize_rcu();
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister_one);

void nf_ct_l4proto_pernet_unregister_one(struct net *net,
					 struct nf_conntrack_l4proto *l4proto)
{
	struct nf_proto_net *pn = nf_ct_l4proto_net(net, l4proto);

	if (pn == NULL)
		return;

	pn->users--;
	nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister_one);

int nf_ct_l4proto_register(struct nf_conntrack_l4proto *l4proto[],
			   unsigned int num_proto)
{
	int ret = -EINVAL, ver;
	unsigned int i;

	for (i = 0; i < num_proto; i++) {
		ret = nf_ct_l4proto_register_one(l4proto[i]);
		if (ret < 0)
			break;
	}
	if (i != num_proto) {
		ver = l4proto[i]->l3proto == PF_INET6 ? 6 : 4;
		pr_err("nf_conntrack_ipv%d: can't register %s%d proto.\n",
		       ver, l4proto[i]->name, ver);
		nf_ct_l4proto_unregister(l4proto, i);
	}
	return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);

int nf_ct_l4proto_pernet_register(struct net *net,
				  struct nf_conntrack_l4proto *l4proto[],
				  unsigned int num_proto)
{
	int ret = -EINVAL;
	unsigned int i;

	for (i = 0; i < num_proto; i++) {
		ret = nf_ct_l4proto_pernet_register_one(net, l4proto[i]);
		if (ret < 0)
			break;
	}
	if (i != num_proto) {
		pr_err("nf_conntrack_%s%d: pernet registration failed\n",
		       l4proto[i]->name,
		       l4proto[i]->l3proto == PF_INET6 ? 6 : 4);
		nf_ct_l4proto_pernet_unregister(net, l4proto, i);
	}
	return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);

void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto[],
			      unsigned int num_proto)
{
	mutex_lock(&nf_ct_proto_mutex);
	while (num_proto-- != 0)
		__nf_ct_l4proto_unregister_one(l4proto[num_proto]);
	mutex_unlock(&nf_ct_proto_mutex);

	synchronize_net();
	/* Remove all contrack entries for this protocol */
	nf_ct_iterate_destroy(kill_l4proto, l4proto);
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);

void nf_ct_l4proto_pernet_unregister(struct net *net,
				     struct nf_conntrack_l4proto *l4proto[],
				     unsigned int num_proto)
{
	while (num_proto-- != 0)
		nf_ct_l4proto_pernet_unregister_one(net, l4proto[num_proto]);
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);

int nf_conntrack_proto_pernet_init(struct net *net)
{
	int err;
	struct nf_proto_net *pn = nf_ct_l4proto_net(net,
					&nf_conntrack_l4proto_generic);

	err = nf_conntrack_l4proto_generic.init_net(net,
					nf_conntrack_l4proto_generic.l3proto);
	if (err < 0)
		return err;
	err = nf_ct_l4proto_register_sysctl(net,
					    pn,
					    &nf_conntrack_l4proto_generic);
	if (err < 0)
		return err;

	pn->users++;
	return 0;
}

void nf_conntrack_proto_pernet_fini(struct net *net)
{
	struct nf_proto_net *pn = nf_ct_l4proto_net(net,
					&nf_conntrack_l4proto_generic);

	pn->users--;
	nf_ct_l4proto_unregister_sysctl(net,
					pn,
					&nf_conntrack_l4proto_generic);
}

int nf_conntrack_proto_init(void)
{
	unsigned int i;
	for (i = 0; i < NFPROTO_NUMPROTO; i++)
		rcu_assign_pointer(nf_ct_l3protos[i],
				   &nf_conntrack_l3proto_generic);
	return 0;
}

void nf_conntrack_proto_fini(void)
{
	unsigned int i;
	/* free l3proto protocol tables */
	for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++)
		kfree(nf_ct_protos[i]);
}
Commit	Line	Data
8f03dea5 MJ	1	/* L3/L4 protocol support for nf_conntrack. */
	2
	3	/* (C) 1999-2001 Paul `Rusty' Russell
	4	* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
	5	* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
f229f6ce	6	* (C) 2006-2012 Patrick McHardy <kaber@trash.net>
8f03dea5 MJ	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/types.h>
	14	#include <linux/netfilter.h>
	15	#include <linux/module.h>
5a0e3ad6	16	#include <linux/slab.h>
d62f9ed4	17	#include <linux/mutex.h>
8f03dea5 MJ	18	#include <linux/vmalloc.h>
	19	#include <linux/stddef.h>
	20	#include <linux/err.h>
	21	#include <linux/percpu.h>
8f03dea5 MJ	22	#include <linux/notifier.h>
	23	#include <linux/kernel.h>
	24	#include <linux/netdevice.h>
	25
	26	#include <net/netfilter/nf_conntrack.h>
	27	#include <net/netfilter/nf_conntrack_l3proto.h>
605dcad6	28	#include <net/netfilter/nf_conntrack_l4proto.h>
8f03dea5 MJ	29	#include <net/netfilter/nf_conntrack_core.h>
8f03dea5 MJ	30
b7b5fda4 FW	31	static struct nf_conntrack_l4proto __rcu **nf_ct_protos[NFPROTO_NUMPROTO] __read_mostly;
b7b5fda4 FW	32	struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[NFPROTO_NUMPROTO] __read_mostly;
13b18339	33	EXPORT_SYMBOL_GPL(nf_ct_l3protos);
8f03dea5	34
b19caa0c	35	static DEFINE_MUTEX(nf_ct_proto_mutex);
d62f9ed4	36
b19caa0c	37	#ifdef CONFIG_SYSCTL
d62f9ed4	38	static int
2c352f44 G	39	nf_ct_register_sysctl(struct net *net,
	40	struct ctl_table_header **header,
	41	const char *path,
fa34fff5	42	struct ctl_table *table)
d62f9ed4 PM	43	{
d62f9ed4 PM	44	if (*header == NULL) {
2c352f44	45	*header = register_net_sysctl(net, path, table);
d62f9ed4 PM	46	if (*header == NULL)
	47	return -ENOMEM;
	48	}
2c352f44	49
d62f9ed4 PM	50	return 0;
	51	}
	52
	53	static void
	54	nf_ct_unregister_sysctl(struct ctl_table_header **header,
2c352f44	55	struct ctl_table **table,
fa34fff5	56	unsigned int users)
d62f9ed4	57	{
fa34fff5	58	if (users > 0)
d62f9ed4	59	return;
b3fd3ffe	60
5dd3df10	61	unregister_net_sysctl_table(*header);
2c352f44	62	kfree(*table);
d62f9ed4	63	*header = NULL;
2c352f44	64	*table = NULL;
d62f9ed4 PM	65	}
	66	#endif
	67
605dcad6 MJ	68	struct nf_conntrack_l4proto *
605dcad6 MJ	69	__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
8f03dea5	70	{
b7b5fda4	71	if (unlikely(l3proto >= NFPROTO_NUMPROTO \|\| nf_ct_protos[l3proto] == NULL))
605dcad6	72	return &nf_conntrack_l4proto_generic;
8f03dea5	73
923f4902	74	return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
8f03dea5	75	}
13b18339	76	EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
8f03dea5 MJ	77
	78	/* this is guaranteed to always return a valid protocol helper, since
	79	* it falls back to generic_protocol */
8f03dea5 MJ	80	struct nf_conntrack_l3proto *
	81	nf_ct_l3proto_find_get(u_int16_t l3proto)
	82	{
	83	struct nf_conntrack_l3proto *p;
	84
923f4902	85	rcu_read_lock();
8f03dea5 MJ	86	p = __nf_ct_l3proto_find(l3proto);
8f03dea5 MJ	87	if (!try_module_get(p->me))
605dcad6	88	p = &nf_conntrack_l3proto_generic;
923f4902	89	rcu_read_unlock();
8f03dea5 MJ	90
	91	return p;
	92	}
13b18339	93	EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
8f03dea5	94
8f03dea5 MJ	95	int
	96	nf_ct_l3proto_try_module_get(unsigned short l3proto)
	97	{
	98	int ret;
	99	struct nf_conntrack_l3proto *p;
	100
	101	retry: p = nf_ct_l3proto_find_get(l3proto);
605dcad6	102	if (p == &nf_conntrack_l3proto_generic) {
8f03dea5 MJ	103	ret = request_module("nf_conntrack-%d", l3proto);
	104	if (!ret)
	105	goto retry;
	106
	107	return -EPROTOTYPE;
	108	}
	109
	110	return 0;
	111	}
13b18339	112	EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
8f03dea5 MJ	113
	114	void nf_ct_l3proto_module_put(unsigned short l3proto)
	115	{
	116	struct nf_conntrack_l3proto *p;
	117
3b254c54 PM	118	/* rcu_read_lock not necessary since the caller holds a reference, but
	119	* taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
	120	*/
	121	rcu_read_lock();
8f03dea5	122	p = __nf_ct_l3proto_find(l3proto);
8f03dea5	123	module_put(p->me);
3b254c54	124	rcu_read_unlock();
8f03dea5	125	}
13b18339	126	EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
8f03dea5	127
ecb2421b FW	128	int nf_ct_netns_get(struct net *net, u8 nfproto)
ecb2421b FW	129	{
0c66dc1e FW	130	const struct nf_conntrack_l3proto *l3proto;
	131	int ret;
	132
	133	might_sleep();
	134
	135	ret = nf_ct_l3proto_try_module_get(nfproto);
	136	if (ret < 0)
	137	return ret;
	138
	139	/* we already have a reference, can't fail */
	140	rcu_read_lock();
	141	l3proto = __nf_ct_l3proto_find(nfproto);
	142	rcu_read_unlock();
	143
	144	if (!l3proto->net_ns_get)
	145	return 0;
	146
	147	ret = l3proto->net_ns_get(net);
	148	if (ret < 0)
	149	nf_ct_l3proto_module_put(nfproto);
	150
	151	return ret;
ecb2421b FW	152	}
	153	EXPORT_SYMBOL_GPL(nf_ct_netns_get);
	154
	155	void nf_ct_netns_put(struct net *net, u8 nfproto)
	156	{
0c66dc1e FW	157	const struct nf_conntrack_l3proto *l3proto;
	158
	159	might_sleep();
	160
	161	/* same as nf_conntrack_netns_get(), reference assumed */
	162	rcu_read_lock();
	163	l3proto = __nf_ct_l3proto_find(nfproto);
	164	rcu_read_unlock();
	165
	166	if (WARN_ON(!l3proto))
	167	return;
	168
	169	if (l3proto->net_ns_put)
	170	l3proto->net_ns_put(net);
	171
ecb2421b FW	172	nf_ct_l3proto_module_put(nfproto);
	173	}
	174	EXPORT_SYMBOL_GPL(nf_ct_netns_put);
	175
c1ebd7df PNA	176	struct nf_conntrack_l4proto *
	177	nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
	178	{
	179	struct nf_conntrack_l4proto *p;
	180
	181	rcu_read_lock();
	182	p = __nf_ct_l4proto_find(l3num, l4num);
	183	if (!try_module_get(p->me))
	184	p = &nf_conntrack_l4proto_generic;
	185	rcu_read_unlock();
	186
	187	return p;
	188	}
	189	EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
	190
	191	void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
	192	{
	193	module_put(p->me);
	194	}
	195	EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
	196
8f03dea5 MJ	197	static int kill_l3proto(struct nf_conn i, void data)
8f03dea5 MJ	198	{
5e8fbe2a	199	return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
8f03dea5 MJ	200	}
8f03dea5 MJ	201
605dcad6	202	static int kill_l4proto(struct nf_conn i, void data)
8f03dea5	203	{
605dcad6	204	struct nf_conntrack_l4proto *l4proto;
68ad546a	205	l4proto = data;
5e8fbe2a PM	206	return nf_ct_protonum(i) == l4proto->l4proto &&
5e8fbe2a PM	207	nf_ct_l3num(i) == l4proto->l3proto;
8f03dea5 MJ	208	}
8f03dea5 MJ	209
6330750d	210	int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)
8f03dea5 MJ	211	{
8f03dea5 MJ	212	int ret = 0;
0e60ebe0	213	struct nf_conntrack_l3proto *old;
8f03dea5	214
b7b5fda4	215	if (proto->l3proto >= NFPROTO_NUMPROTO)
0661cca9	216	return -EBUSY;
ae5718fb	217
d0dba725 HE	218	if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
	219	return -EINVAL;
	220
b19caa0c	221	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	222	old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
	223	lockdep_is_held(&nf_ct_proto_mutex));
	224	if (old != &nf_conntrack_l3proto_generic) {
8f03dea5	225	ret = -EBUSY;
ae5718fb	226	goto out_unlock;
8f03dea5	227	}
d62f9ed4	228
d0dba725 HE	229	if (proto->nlattr_tuple_size)
	230	proto->nla_size = 3 * proto->nlattr_tuple_size();
	231
0661cca9	232	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
8f03dea5	233
ae5718fb	234	out_unlock:
b19caa0c	235	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	236	return ret;
524a53e5	237
8f03dea5	238	}
6330750d	239	EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);
8f03dea5	240
481fa373 FW	241	#ifdef CONFIG_SYSCTL
	242	extern unsigned int nf_conntrack_default_on;
	243
6330750d	244	int nf_ct_l3proto_pernet_register(struct net *net,
524a53e5	245	struct nf_conntrack_l3proto *proto)
8f03dea5	246	{
481fa373 FW	247	if (nf_conntrack_default_on == 0)
	248	return 0;
	249
	250	return proto->net_ns_get ? proto->net_ns_get(net) : 0;
524a53e5	251	}
6330750d	252	EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register);
481fa373	253	#endif
678d6675	254
6330750d	255	void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto)
524a53e5	256	{
b7b5fda4	257	BUG_ON(proto->l3proto >= NFPROTO_NUMPROTO);
ae5718fb	258
b19caa0c	259	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	260	BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
	261	lockdep_is_held(&nf_ct_proto_mutex)
	262	) != proto);
923f4902 PM	263	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
923f4902 PM	264	&nf_conntrack_l3proto_generic);
b19caa0c	265	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	266
0661cca9	267	synchronize_rcu();
2c41f33c FW	268	/* Remove all contrack entries for this protocol */
2c41f33c FW	269	nf_ct_iterate_destroy(kill_l3proto, proto);
524a53e5	270	}
6330750d	271	EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
524a53e5	272
6330750d	273	void nf_ct_l3proto_pernet_unregister(struct net *net,
524a53e5 G	274	struct nf_conntrack_l3proto *proto)
524a53e5 G	275	{
481fa373 FW	276	/*
	277	* nf_conntrack_default_on might have registered hooks.
	278	* ->net_ns_put must cope with more puts() than get(), i.e.
	279	* if nf_conntrack_default_on was 0 at time of
	280	* nf_ct_l3proto_pernet_register invocation this net_ns_put()
	281	* should be a noop.
	282	*/
	283	if (proto->net_ns_put)
	284	proto->net_ns_put(net);
8f03dea5	285	}
6330750d	286	EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister);
8f03dea5	287
2c352f44 G	288	static struct nf_proto_net nf_ct_l4proto_net(struct net net,
	289	struct nf_conntrack_l4proto *l4proto)
	290	{
08911475 PNA	291	if (l4proto->get_net_proto) {
	292	/* statically built-in protocols use static per-net */
	293	return l4proto->get_net_proto(net);
	294	} else if (l4proto->net_id) {
	295	/* ... and loadable protocols use dynamic per-net */
	296	return net_generic(net, *l4proto->net_id);
15f585bd G	297	}
15f585bd G	298	return NULL;
2c352f44 G	299	}
	300
	301	static
	302	int nf_ct_l4proto_register_sysctl(struct net *net,
fa34fff5	303	struct nf_proto_net *pn,
2c352f44	304	struct nf_conntrack_l4proto *l4proto)
d62f9ed4 PM	305	{
	306	int err = 0;
	307
	308	#ifdef CONFIG_SYSCTL
2c352f44 G	309	if (pn->ctl_table != NULL) {
	310	err = nf_ct_register_sysctl(net,
	311	&pn->ctl_table_header,
f99e8f71	312	"net/netfilter",
fa34fff5	313	pn->ctl_table);
2c352f44 G	314	if (err < 0) {
	315	if (!pn->users) {
	316	kfree(pn->ctl_table);
	317	pn->ctl_table = NULL;
	318	}
2c352f44	319	}
d62f9ed4	320	}
933a41e7	321	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	322	return err;
	323	}
	324
2c352f44 G	325	static
2c352f44 G	326	void nf_ct_l4proto_unregister_sysctl(struct net *net,
fa34fff5	327	struct nf_proto_net *pn,
2c352f44	328	struct nf_conntrack_l4proto *l4proto)
d62f9ed4 PM	329	{
d62f9ed4 PM	330	#ifdef CONFIG_SYSCTL
2c352f44 G	331	if (pn->ctl_table_header != NULL)
	332	nf_ct_unregister_sysctl(&pn->ctl_table_header,
	333	&pn->ctl_table,
fa34fff5	334	pn->users);
933a41e7	335	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	336	}
d62f9ed4 PM	337
8f03dea5 MJ	338	/* FIXME: Allow NULL functions and sub in pointers to generic for
8f03dea5 MJ	339	them. --RR */
0e54d217	340	int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *l4proto)
8f03dea5 MJ	341	{
	342	int ret = 0;
	343
b7b5fda4	344	if (l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos))
0661cca9	345	return -EBUSY;
ae5718fb	346
0e54d217 DC	347	if ((l4proto->to_nlattr && !l4proto->nlattr_size) \|\|
0e54d217 DC	348	(l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
d0dba725 HE	349	return -EINVAL;
d0dba725 HE	350
b19caa0c	351	mutex_lock(&nf_ct_proto_mutex);
c6a1e615	352	if (!nf_ct_protos[l4proto->l3proto]) {
8f03dea5	353	/* l3proto may be loaded latter. */
c5d277d2	354	struct nf_conntrack_l4proto __rcu **proto_array;
8f03dea5 MJ	355	int i;
8f03dea5 MJ	356
c6a1e615 PM	357	proto_array = kmalloc(MAX_NF_CT_PROTO *
	358	sizeof(struct nf_conntrack_l4proto *),
	359	GFP_KERNEL);
8f03dea5 MJ	360	if (proto_array == NULL) {
8f03dea5 MJ	361	ret = -ENOMEM;
b19caa0c	362	goto out_unlock;
8f03dea5	363	}
c6a1e615	364
8f03dea5	365	for (i = 0; i < MAX_NF_CT_PROTO; i++)
0e54d217 DC	366	RCU_INIT_POINTER(proto_array[i],
0e54d217 DC	367	&nf_conntrack_l4proto_generic);
d817d29d ED	368
	369	/* Before making proto_array visible to lockless readers,
	370	* we must make sure its content is committed to memory.
	371	*/
	372	smp_wmb();
	373
c6a1e615	374	nf_ct_protos[l4proto->l3proto] = proto_array;
0e60ebe0 ED	375	} else if (rcu_dereference_protected(
	376	nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
	377	lockdep_is_held(&nf_ct_proto_mutex)
	378	) != &nf_conntrack_l4proto_generic) {
c6a1e615 PM	379	ret = -EBUSY;
c6a1e615 PM	380	goto out_unlock;
8f03dea5 MJ	381	}
8f03dea5 MJ	382
d0dba725 HE	383	l4proto->nla_size = 0;
	384	if (l4proto->nlattr_size)
	385	l4proto->nla_size += l4proto->nlattr_size();
	386	if (l4proto->nlattr_tuple_size)
	387	l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
	388
c6a1e615 PM	389	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
c6a1e615 PM	390	l4proto);
8f03dea5	391	out_unlock:
b19caa0c	392	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5 MJ	393	return ret;
8f03dea5 MJ	394	}
0e54d217	395	EXPORT_SYMBOL_GPL(nf_ct_l4proto_register_one);
8f03dea5	396
0e54d217 DC	397	int nf_ct_l4proto_pernet_register_one(struct net *net,
0e54d217 DC	398	struct nf_conntrack_l4proto *l4proto)
8f03dea5	399	{
2c352f44	400	int ret = 0;
fa34fff5	401	struct nf_proto_net *pn = NULL;
2c352f44	402
fa0f61f0	403	if (l4proto->init_net) {
f1caad27	404	ret = l4proto->init_net(net, l4proto->l3proto);
fa0f61f0	405	if (ret < 0)
fa34fff5	406	goto out;
fa0f61f0	407	}
678d6675	408
fa34fff5 G	409	pn = nf_ct_l4proto_net(net, l4proto);
	410	if (pn == NULL)
	411	goto out;
	412
	413	ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
2c352f44	414	if (ret < 0)
fa34fff5	415	goto out;
2c352f44	416
fa34fff5 G	417	pn->users++;
fa34fff5 G	418	out:
fa0f61f0	419	return ret;
2c352f44	420	}
0e54d217	421	EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register_one);
2c352f44	422
2c41f33c FW	423	static void __nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
2c41f33c FW	424
2c352f44	425	{
b7b5fda4	426	BUG_ON(l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos));
ae5718fb	427
0e60ebe0 ED	428	BUG_ON(rcu_dereference_protected(
	429	nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
	430	lockdep_is_held(&nf_ct_proto_mutex)
	431	) != l4proto);
923f4902 PM	432	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
923f4902 PM	433	&nf_conntrack_l4proto_generic);
2c41f33c FW	434	}
	435
	436	void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
	437	{
	438	mutex_lock(&nf_ct_proto_mutex);
	439	__nf_ct_l4proto_unregister_one(l4proto);
b19caa0c	440	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	441
0661cca9	442	synchronize_rcu();
2c352f44	443	}
0e54d217	444	EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister_one);
d62f9ed4	445
0e54d217 DC	446	void nf_ct_l4proto_pernet_unregister_one(struct net *net,
0e54d217 DC	447	struct nf_conntrack_l4proto *l4proto)
2c352f44	448	{
809c2d9a	449	struct nf_proto_net *pn = nf_ct_l4proto_net(net, l4proto);
fa34fff5	450
fa34fff5 G	451	if (pn == NULL)
	452	return;
	453
	454	pn->users--;
	455	nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
8f03dea5	456	}
0e54d217 DC	457	EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister_one);
	458
	459	int nf_ct_l4proto_register(struct nf_conntrack_l4proto *l4proto[],
	460	unsigned int num_proto)
	461	{
	462	int ret = -EINVAL, ver;
	463	unsigned int i;
	464
	465	for (i = 0; i < num_proto; i++) {
	466	ret = nf_ct_l4proto_register_one(l4proto[i]);
	467	if (ret < 0)
	468	break;
	469	}
	470	if (i != num_proto) {
	471	ver = l4proto[i]->l3proto == PF_INET6 ? 6 : 4;
	472	pr_err("nf_conntrack_ipv%d: can't register %s%d proto.\n",
	473	ver, l4proto[i]->name, ver);
	474	nf_ct_l4proto_unregister(l4proto, i);
	475	}
	476	return ret;
	477	}
	478	EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);
	479
	480	int nf_ct_l4proto_pernet_register(struct net *net,
	481	struct nf_conntrack_l4proto *l4proto[],
	482	unsigned int num_proto)
	483	{
	484	int ret = -EINVAL;
	485	unsigned int i;
	486
	487	for (i = 0; i < num_proto; i++) {
	488	ret = nf_ct_l4proto_pernet_register_one(net, l4proto[i]);
	489	if (ret < 0)
	490	break;
	491	}
	492	if (i != num_proto) {
	493	pr_err("nf_conntrack_%s%d: pernet registration failed\n",
	494	l4proto[i]->name,
	495	l4proto[i]->l3proto == PF_INET6 ? 6 : 4);
	496	nf_ct_l4proto_pernet_unregister(net, l4proto, i);
	497	}
	498	return ret;
	499	}
	500	EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);
	501
	502	void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto[],
	503	unsigned int num_proto)
	504	{
2c41f33c	505	mutex_lock(&nf_ct_proto_mutex);
0e54d217	506	while (num_proto-- != 0)
2c41f33c FW	507	__nf_ct_l4proto_unregister_one(l4proto[num_proto]);
	508	mutex_unlock(&nf_ct_proto_mutex);
	509
	510	synchronize_net();
	511	/* Remove all contrack entries for this protocol */
	512	nf_ct_iterate_destroy(kill_l4proto, l4proto);
0e54d217 DC	513	}
	514	EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);
	515
	516	void nf_ct_l4proto_pernet_unregister(struct net *net,
	517	struct nf_conntrack_l4proto *l4proto[],
	518	unsigned int num_proto)
	519	{
	520	while (num_proto-- != 0)
	521	nf_ct_l4proto_pernet_unregister_one(net, l4proto[num_proto]);
	522	}
c296bb4d	523	EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);
ac5357eb	524
04d87001	525	int nf_conntrack_proto_pernet_init(struct net *net)
ac5357eb	526	{
ac5357eb	527	int err;
fa34fff5 G	528	struct nf_proto_net *pn = nf_ct_l4proto_net(net,
	529	&nf_conntrack_l4proto_generic);
	530
f1caad27 G	531	err = nf_conntrack_l4proto_generic.init_net(net,
f1caad27 G	532	nf_conntrack_l4proto_generic.l3proto);
15f585bd G	533	if (err < 0)
	534	return err;
	535	err = nf_ct_l4proto_register_sysctl(net,
fa34fff5	536	pn,
15f585bd	537	&nf_conntrack_l4proto_generic);
ac5357eb PM	538	if (err < 0)
	539	return err;
	540
fa34fff5	541	pn->users++;
ac5357eb PM	542	return 0;
	543	}
	544
04d87001	545	void nf_conntrack_proto_pernet_fini(struct net *net)
ac5357eb	546	{
fa34fff5 G	547	struct nf_proto_net *pn = nf_ct_l4proto_net(net,
	548	&nf_conntrack_l4proto_generic);
	549
	550	pn->users--;
15f585bd	551	nf_ct_l4proto_unregister_sysctl(net,
fa34fff5	552	pn,
15f585bd	553	&nf_conntrack_l4proto_generic);
04d87001 G	554	}
	555
	556	int nf_conntrack_proto_init(void)
	557	{
	558	unsigned int i;
b7b5fda4	559	for (i = 0; i < NFPROTO_NUMPROTO; i++)
04d87001 G	560	rcu_assign_pointer(nf_ct_l3protos[i],
	561	&nf_conntrack_l3proto_generic);
	562	return 0;
	563	}
	564
	565	void nf_conntrack_proto_fini(void)
	566	{
	567	unsigned int i;
	568	/* free l3proto protocol tables */
b7b5fda4	569	for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++)
04d87001	570	kfree(nf_ct_protos[i]);
ac5357eb	571	}