[net-next-2.6.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>
 *
 * 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 <linux/rtnetlink.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[PF_MAX] __read_mostly;
struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[AF_MAX] __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 ctl_table_header **header, struct ctl_path *path,
		      struct ctl_table *table, unsigned int *users)
{
	if (*header == NULL) {
		*header = register_sysctl_paths(path, table);
		if (*header == NULL)
			return -ENOMEM;
	}
	if (users != NULL)
		(*users)++;
	return 0;
}

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

	unregister_sysctl_table(*header);
	*header = NULL;
}
#endif

struct nf_conntrack_l4proto *
__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
{
	if (unlikely(l3proto >= AF_MAX || 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);

void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
{
	module_put(p->me);
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);

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);

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 = (struct nf_conntrack_l4proto *)data;
	return nf_ct_protonum(i) == l4proto->l4proto &&
	       nf_ct_l3num(i) == l4proto->l3proto;
}

static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
{
	int err = 0;

#ifdef CONFIG_SYSCTL
	if (l3proto->ctl_table != NULL) {
		err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
					    l3proto->ctl_table_path,
					    l3proto->ctl_table, NULL);
	}
#endif
	return err;
}

static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
{
#ifdef CONFIG_SYSCTL
	if (l3proto->ctl_table_header != NULL)
		nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
					l3proto->ctl_table, NULL);
#endif
}

int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
{
	int ret = 0;

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

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

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

	ret = nf_ct_l3proto_register_sysctl(proto);
	if (ret < 0)
		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_conntrack_l3proto_register);

void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
{
	struct net *net;

	BUG_ON(proto->l3proto >= AF_MAX);

	mutex_lock(&nf_ct_proto_mutex);
	BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
			   &nf_conntrack_l3proto_generic);
	nf_ct_l3proto_unregister_sysctl(proto);
	mutex_unlock(&nf_ct_proto_mutex);

	synchronize_rcu();

	/* Remove all contrack entries for this protocol */
	rtnl_lock();
	for_each_net(net)
		nf_ct_iterate_cleanup(net, kill_l3proto, proto);
	rtnl_unlock();
}
EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);

static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
{
	int err = 0;

#ifdef CONFIG_SYSCTL
	if (l4proto->ctl_table != NULL) {
		err = nf_ct_register_sysctl(l4proto->ctl_table_header,
					    nf_net_netfilter_sysctl_path,
					    l4proto->ctl_table,
					    l4proto->ctl_table_users);
		if (err < 0)
			goto out;
	}
#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	if (l4proto->ctl_compat_table != NULL) {
		err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
					    nf_net_ipv4_netfilter_sysctl_path,
					    l4proto->ctl_compat_table, NULL);
		if (err == 0)
			goto out;
		nf_ct_unregister_sysctl(l4proto->ctl_table_header,
					l4proto->ctl_table,
					l4proto->ctl_table_users);
	}
#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
out:
#endif /* CONFIG_SYSCTL */
	return err;
}

static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
{
#ifdef CONFIG_SYSCTL
	if (l4proto->ctl_table_header != NULL &&
	    *l4proto->ctl_table_header != NULL)
		nf_ct_unregister_sysctl(l4proto->ctl_table_header,
					l4proto->ctl_table,
					l4proto->ctl_table_users);
#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	if (l4proto->ctl_compat_table_header != NULL)
		nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
					l4proto->ctl_compat_table, NULL);
#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
#endif /* CONFIG_SYSCTL */
}

/* FIXME: Allow NULL functions and sub in pointers to generic for
   them. --RR */
int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
{
	int ret = 0;

	if (l4proto->l3proto >= PF_MAX)
		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 **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++)
			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 (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
					&nf_conntrack_l4proto_generic) {
		ret = -EBUSY;
		goto out_unlock;
	}

	ret = nf_ct_l4proto_register_sysctl(l4proto);
	if (ret < 0)
		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_conntrack_l4proto_register);

void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
{
	struct net *net;

	BUG_ON(l4proto->l3proto >= PF_MAX);

	mutex_lock(&nf_ct_proto_mutex);
	BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
			   &nf_conntrack_l4proto_generic);
	nf_ct_l4proto_unregister_sysctl(l4proto);
	mutex_unlock(&nf_ct_proto_mutex);

	synchronize_rcu();

	/* Remove all contrack entries for this protocol */
	rtnl_lock();
	for_each_net(net)
		nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
	rtnl_unlock();
}
EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);

int nf_conntrack_proto_init(void)
{
	unsigned int i;
	int err;

	err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
	if (err < 0)
		return err;

	for (i = 0; i < AF_MAX; i++)
		rcu_assign_pointer(nf_ct_l3protos[i],
				   &nf_conntrack_l3proto_generic);
	return 0;
}

void nf_conntrack_proto_fini(void)
{
	unsigned int i;

	nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);

	/* free l3proto protocol tables */
	for (i = 0; i < PF_MAX; 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>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/types.h>
	13	#include <linux/netfilter.h>
	14	#include <linux/module.h>
5a0e3ad6	15	#include <linux/slab.h>
d62f9ed4	16	#include <linux/mutex.h>
8f03dea5 MJ	17	#include <linux/vmalloc.h>
	18	#include <linux/stddef.h>
	19	#include <linux/err.h>
	20	#include <linux/percpu.h>
8f03dea5 MJ	21	#include <linux/notifier.h>
	22	#include <linux/kernel.h>
	23	#include <linux/netdevice.h>
efb9a8c2	24	#include <linux/rtnetlink.h>
8f03dea5 MJ	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
0906a372 AB	31	static struct nf_conntrack_l4proto __rcu **nf_ct_protos[PF_MAX] __read_mostly;
0906a372 AB	32	struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[AF_MAX] __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
b3fd3ffe	39	nf_ct_register_sysctl(struct ctl_table_header *header, struct ctl_path path,
d62f9ed4 PM	40	struct ctl_table table, unsigned int users)
	41	{
	42	if (*header == NULL) {
b3fd3ffe	43	*header = register_sysctl_paths(path, table);
d62f9ed4 PM	44	if (*header == NULL)
	45	return -ENOMEM;
	46	}
	47	if (users != NULL)
	48	(*users)++;
	49	return 0;
	50	}
	51
	52	static void
	53	nf_ct_unregister_sysctl(struct ctl_table_header **header,
	54	struct ctl_table table, unsigned int users)
	55	{
	56	if (users != NULL && --*users > 0)
	57	return;
b3fd3ffe PE	58
b3fd3ffe PE	59	unregister_sysctl_table(*header);
d62f9ed4 PM	60	*header = NULL;
	61	}
	62	#endif
	63
605dcad6 MJ	64	struct nf_conntrack_l4proto *
605dcad6 MJ	65	__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
8f03dea5 MJ	66	{
8f03dea5 MJ	67	if (unlikely(l3proto >= AF_MAX \|\| nf_ct_protos[l3proto] == NULL))
605dcad6	68	return &nf_conntrack_l4proto_generic;
8f03dea5	69
923f4902	70	return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
8f03dea5	71	}
13b18339	72	EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
8f03dea5 MJ	73
	74	/* this is guaranteed to always return a valid protocol helper, since
	75	* it falls back to generic_protocol */
8f03dea5 MJ	76	struct nf_conntrack_l3proto *
	77	nf_ct_l3proto_find_get(u_int16_t l3proto)
	78	{
	79	struct nf_conntrack_l3proto *p;
	80
923f4902	81	rcu_read_lock();
8f03dea5 MJ	82	p = __nf_ct_l3proto_find(l3proto);
8f03dea5 MJ	83	if (!try_module_get(p->me))
605dcad6	84	p = &nf_conntrack_l3proto_generic;
923f4902	85	rcu_read_unlock();
8f03dea5 MJ	86
	87	return p;
	88	}
13b18339	89	EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
8f03dea5 MJ	90
	91	void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
	92	{
	93	module_put(p->me);
	94	}
13b18339	95	EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
8f03dea5 MJ	96
	97	int
	98	nf_ct_l3proto_try_module_get(unsigned short l3proto)
	99	{
	100	int ret;
	101	struct nf_conntrack_l3proto *p;
	102
	103	retry: p = nf_ct_l3proto_find_get(l3proto);
605dcad6	104	if (p == &nf_conntrack_l3proto_generic) {
8f03dea5 MJ	105	ret = request_module("nf_conntrack-%d", l3proto);
	106	if (!ret)
	107	goto retry;
	108
	109	return -EPROTOTYPE;
	110	}
	111
	112	return 0;
	113	}
13b18339	114	EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
8f03dea5 MJ	115
	116	void nf_ct_l3proto_module_put(unsigned short l3proto)
	117	{
	118	struct nf_conntrack_l3proto *p;
	119
3b254c54 PM	120	/* rcu_read_lock not necessary since the caller holds a reference, but
	121	* taken anyways to avoid lockdep warnings in __nf_ct_l3proto_find()
	122	*/
	123	rcu_read_lock();
8f03dea5	124	p = __nf_ct_l3proto_find(l3proto);
8f03dea5	125	module_put(p->me);
3b254c54	126	rcu_read_unlock();
8f03dea5	127	}
13b18339	128	EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
8f03dea5 MJ	129
	130	static int kill_l3proto(struct nf_conn i, void data)
	131	{
5e8fbe2a	132	return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
8f03dea5 MJ	133	}
8f03dea5 MJ	134
605dcad6	135	static int kill_l4proto(struct nf_conn i, void data)
8f03dea5	136	{
605dcad6 MJ	137	struct nf_conntrack_l4proto *l4proto;
605dcad6 MJ	138	l4proto = (struct nf_conntrack_l4proto *)data;
5e8fbe2a PM	139	return nf_ct_protonum(i) == l4proto->l4proto &&
5e8fbe2a PM	140	nf_ct_l3num(i) == l4proto->l3proto;
8f03dea5 MJ	141	}
8f03dea5 MJ	142
d62f9ed4 PM	143	static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
	144	{
	145	int err = 0;
	146
	147	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	148	if (l3proto->ctl_table != NULL) {
	149	err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
	150	l3proto->ctl_table_path,
	151	l3proto->ctl_table, NULL);
	152	}
d62f9ed4 PM	153	#endif
	154	return err;
	155	}
	156
	157	static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
	158	{
	159	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	160	if (l3proto->ctl_table_header != NULL)
	161	nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
	162	l3proto->ctl_table, NULL);
d62f9ed4 PM	163	#endif
	164	}
	165
8f03dea5 MJ	166	int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
	167	{
	168	int ret = 0;
	169
0661cca9 PM	170	if (proto->l3proto >= AF_MAX)
0661cca9 PM	171	return -EBUSY;
ae5718fb	172
d0dba725 HE	173	if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
	174	return -EINVAL;
	175
b19caa0c	176	mutex_lock(&nf_ct_proto_mutex);
605dcad6	177	if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
8f03dea5	178	ret = -EBUSY;
ae5718fb	179	goto out_unlock;
8f03dea5	180	}
d62f9ed4 PM	181
	182	ret = nf_ct_l3proto_register_sysctl(proto);
	183	if (ret < 0)
0661cca9 PM	184	goto out_unlock;
0661cca9 PM	185
d0dba725 HE	186	if (proto->nlattr_tuple_size)
	187	proto->nla_size = 3 * proto->nlattr_tuple_size();
	188
0661cca9	189	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
8f03dea5	190
ae5718fb	191	out_unlock:
b19caa0c	192	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5 MJ	193	return ret;
8f03dea5 MJ	194	}
13b18339	195	EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
8f03dea5	196
fe3eb20c	197	void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
8f03dea5	198	{
678d6675 AD	199	struct net *net;
678d6675 AD	200
fe3eb20c	201	BUG_ON(proto->l3proto >= AF_MAX);
ae5718fb	202
b19caa0c	203	mutex_lock(&nf_ct_proto_mutex);
fe3eb20c	204	BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
923f4902 PM	205	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
923f4902 PM	206	&nf_conntrack_l3proto_generic);
0661cca9	207	nf_ct_l3proto_unregister_sysctl(proto);
b19caa0c	208	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	209
0661cca9	210	synchronize_rcu();
d62f9ed4	211
8f03dea5	212	/* Remove all contrack entries for this protocol */
efb9a8c2	213	rtnl_lock();
678d6675 AD	214	for_each_net(net)
678d6675 AD	215	nf_ct_iterate_cleanup(net, kill_l3proto, proto);
efb9a8c2	216	rtnl_unlock();
8f03dea5	217	}
13b18339	218	EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
8f03dea5	219
d62f9ed4 PM	220	static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
	221	{
	222	int err = 0;
	223
	224	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	225	if (l4proto->ctl_table != NULL) {
	226	err = nf_ct_register_sysctl(l4proto->ctl_table_header,
	227	nf_net_netfilter_sysctl_path,
	228	l4proto->ctl_table,
	229	l4proto->ctl_table_users);
a999e683 PM	230	if (err < 0)
a999e683 PM	231	goto out;
d62f9ed4	232	}
a999e683 PM	233	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	234	if (l4proto->ctl_compat_table != NULL) {
	235	err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
	236	nf_net_ipv4_netfilter_sysctl_path,
	237	l4proto->ctl_compat_table, NULL);
	238	if (err == 0)
	239	goto out;
	240	nf_ct_unregister_sysctl(l4proto->ctl_table_header,
	241	l4proto->ctl_table,
	242	l4proto->ctl_table_users);
	243	}
	244	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
	245	out:
933a41e7	246	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	247	return err;
	248	}
	249
	250	static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
	251	{
	252	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	253	if (l4proto->ctl_table_header != NULL &&
	254	*l4proto->ctl_table_header != NULL)
	255	nf_ct_unregister_sysctl(l4proto->ctl_table_header,
	256	l4proto->ctl_table,
	257	l4proto->ctl_table_users);
a999e683 PM	258	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	259	if (l4proto->ctl_compat_table_header != NULL)
	260	nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
	261	l4proto->ctl_compat_table, NULL);
	262	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
933a41e7	263	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	264	}
d62f9ed4 PM	265
8f03dea5 MJ	266	/* FIXME: Allow NULL functions and sub in pointers to generic for
8f03dea5 MJ	267	them. --RR */
605dcad6	268	int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
8f03dea5 MJ	269	{
	270	int ret = 0;
	271
0661cca9 PM	272	if (l4proto->l3proto >= PF_MAX)
0661cca9 PM	273	return -EBUSY;
ae5718fb	274
d0dba725 HE	275	if ((l4proto->to_nlattr && !l4proto->nlattr_size)
	276	\|\| (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
	277	return -EINVAL;
	278
b19caa0c	279	mutex_lock(&nf_ct_proto_mutex);
c6a1e615	280	if (!nf_ct_protos[l4proto->l3proto]) {
8f03dea5	281	/* l3proto may be loaded latter. */
605dcad6	282	struct nf_conntrack_l4proto **proto_array;
8f03dea5 MJ	283	int i;
8f03dea5 MJ	284
c6a1e615 PM	285	proto_array = kmalloc(MAX_NF_CT_PROTO *
	286	sizeof(struct nf_conntrack_l4proto *),
	287	GFP_KERNEL);
8f03dea5 MJ	288	if (proto_array == NULL) {
8f03dea5 MJ	289	ret = -ENOMEM;
b19caa0c	290	goto out_unlock;
8f03dea5	291	}
c6a1e615	292
8f03dea5	293	for (i = 0; i < MAX_NF_CT_PROTO; i++)
605dcad6	294	proto_array[i] = &nf_conntrack_l4proto_generic;
d817d29d ED	295
	296	/* Before making proto_array visible to lockless readers,
	297	* we must make sure its content is committed to memory.
	298	*/
	299	smp_wmb();
	300
c6a1e615 PM	301	nf_ct_protos[l4proto->l3proto] = proto_array;
	302	} else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
	303	&nf_conntrack_l4proto_generic) {
	304	ret = -EBUSY;
	305	goto out_unlock;
8f03dea5 MJ	306	}
8f03dea5 MJ	307
d62f9ed4 PM	308	ret = nf_ct_l4proto_register_sysctl(l4proto);
d62f9ed4 PM	309	if (ret < 0)
0661cca9 PM	310	goto out_unlock;
0661cca9 PM	311
d0dba725 HE	312	l4proto->nla_size = 0;
	313	if (l4proto->nlattr_size)
	314	l4proto->nla_size += l4proto->nlattr_size();
	315	if (l4proto->nlattr_tuple_size)
	316	l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
	317
c6a1e615 PM	318	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
c6a1e615 PM	319	l4proto);
8f03dea5 MJ	320
8f03dea5 MJ	321	out_unlock:
b19caa0c	322	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5 MJ	323	return ret;
8f03dea5 MJ	324	}
13b18339	325	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
8f03dea5	326
fe3eb20c	327	void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
8f03dea5	328	{
678d6675 AD	329	struct net *net;
678d6675 AD	330
fe3eb20c	331	BUG_ON(l4proto->l3proto >= PF_MAX);
ae5718fb	332
b19caa0c	333	mutex_lock(&nf_ct_proto_mutex);
fe3eb20c	334	BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
923f4902 PM	335	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
923f4902 PM	336	&nf_conntrack_l4proto_generic);
0661cca9	337	nf_ct_l4proto_unregister_sysctl(l4proto);
b19caa0c	338	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	339
0661cca9	340	synchronize_rcu();
d62f9ed4	341
8f03dea5	342	/* Remove all contrack entries for this protocol */
efb9a8c2	343	rtnl_lock();
678d6675 AD	344	for_each_net(net)
678d6675 AD	345	nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
efb9a8c2	346	rtnl_unlock();
8f03dea5	347	}
13b18339	348	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
ac5357eb PM	349
	350	int nf_conntrack_proto_init(void)
	351	{
	352	unsigned int i;
	353	int err;
	354
	355	err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
	356	if (err < 0)
	357	return err;
	358
	359	for (i = 0; i < AF_MAX; i++)
	360	rcu_assign_pointer(nf_ct_l3protos[i],
	361	&nf_conntrack_l3proto_generic);
	362	return 0;
	363	}
	364
	365	void nf_conntrack_proto_fini(void)
	366	{
	367	unsigned int i;
	368
	369	nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
	370
	371	/* free l3proto protocol tables */
	372	for (i = 0; i < PF_MAX; i++)
	373	kfree(nf_ct_protos[i]);
	374	}