[mirror_ubuntu-bionic-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>
 *
 * 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);

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 = (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;
	struct nf_conntrack_l3proto *old;

	if (proto->l3proto >= AF_MAX)
		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;
	}

	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(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);
	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 __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;
	}

	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(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);
	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	129
c1ebd7df PNA	130	struct nf_conntrack_l4proto *
	131	nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
	132	{
	133	struct nf_conntrack_l4proto *p;
	134
	135	rcu_read_lock();
	136	p = __nf_ct_l4proto_find(l3num, l4num);
	137	if (!try_module_get(p->me))
	138	p = &nf_conntrack_l4proto_generic;
	139	rcu_read_unlock();
	140
	141	return p;
	142	}
	143	EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
	144
	145	void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
	146	{
	147	module_put(p->me);
	148	}
	149	EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
	150
8f03dea5 MJ	151	static int kill_l3proto(struct nf_conn i, void data)
8f03dea5 MJ	152	{
5e8fbe2a	153	return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
8f03dea5 MJ	154	}
8f03dea5 MJ	155
605dcad6	156	static int kill_l4proto(struct nf_conn i, void data)
8f03dea5	157	{
605dcad6 MJ	158	struct nf_conntrack_l4proto *l4proto;
605dcad6 MJ	159	l4proto = (struct nf_conntrack_l4proto *)data;
5e8fbe2a PM	160	return nf_ct_protonum(i) == l4proto->l4proto &&
5e8fbe2a PM	161	nf_ct_l3num(i) == l4proto->l3proto;
8f03dea5 MJ	162	}
8f03dea5 MJ	163
d62f9ed4 PM	164	static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
	165	{
	166	int err = 0;
	167
	168	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	169	if (l3proto->ctl_table != NULL) {
	170	err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
	171	l3proto->ctl_table_path,
	172	l3proto->ctl_table, NULL);
	173	}
d62f9ed4 PM	174	#endif
	175	return err;
	176	}
	177
	178	static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
	179	{
	180	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	181	if (l3proto->ctl_table_header != NULL)
	182	nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
	183	l3proto->ctl_table, NULL);
d62f9ed4 PM	184	#endif
	185	}
	186
8f03dea5 MJ	187	int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
	188	{
	189	int ret = 0;
0e60ebe0	190	struct nf_conntrack_l3proto *old;
8f03dea5	191
0661cca9 PM	192	if (proto->l3proto >= AF_MAX)
0661cca9 PM	193	return -EBUSY;
ae5718fb	194
d0dba725 HE	195	if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
	196	return -EINVAL;
	197
b19caa0c	198	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	199	old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
	200	lockdep_is_held(&nf_ct_proto_mutex));
	201	if (old != &nf_conntrack_l3proto_generic) {
8f03dea5	202	ret = -EBUSY;
ae5718fb	203	goto out_unlock;
8f03dea5	204	}
d62f9ed4 PM	205
	206	ret = nf_ct_l3proto_register_sysctl(proto);
	207	if (ret < 0)
0661cca9 PM	208	goto out_unlock;
0661cca9 PM	209
d0dba725 HE	210	if (proto->nlattr_tuple_size)
	211	proto->nla_size = 3 * proto->nlattr_tuple_size();
	212
0661cca9	213	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
8f03dea5	214
ae5718fb	215	out_unlock:
b19caa0c	216	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5 MJ	217	return ret;
8f03dea5 MJ	218	}
13b18339	219	EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
8f03dea5	220
fe3eb20c	221	void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
8f03dea5	222	{
678d6675 AD	223	struct net *net;
678d6675 AD	224
fe3eb20c	225	BUG_ON(proto->l3proto >= AF_MAX);
ae5718fb	226
b19caa0c	227	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	228	BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
	229	lockdep_is_held(&nf_ct_proto_mutex)
	230	) != proto);
923f4902 PM	231	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
923f4902 PM	232	&nf_conntrack_l3proto_generic);
0661cca9	233	nf_ct_l3proto_unregister_sysctl(proto);
b19caa0c	234	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	235
0661cca9	236	synchronize_rcu();
d62f9ed4	237
8f03dea5	238	/* Remove all contrack entries for this protocol */
efb9a8c2	239	rtnl_lock();
678d6675 AD	240	for_each_net(net)
678d6675 AD	241	nf_ct_iterate_cleanup(net, kill_l3proto, proto);
efb9a8c2	242	rtnl_unlock();
8f03dea5	243	}
13b18339	244	EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
8f03dea5	245
d62f9ed4 PM	246	static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
	247	{
	248	int err = 0;
	249
	250	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	251	if (l4proto->ctl_table != NULL) {
	252	err = nf_ct_register_sysctl(l4proto->ctl_table_header,
	253	nf_net_netfilter_sysctl_path,
	254	l4proto->ctl_table,
	255	l4proto->ctl_table_users);
a999e683 PM	256	if (err < 0)
a999e683 PM	257	goto out;
d62f9ed4	258	}
a999e683 PM	259	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	260	if (l4proto->ctl_compat_table != NULL) {
	261	err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
	262	nf_net_ipv4_netfilter_sysctl_path,
	263	l4proto->ctl_compat_table, NULL);
	264	if (err == 0)
	265	goto out;
	266	nf_ct_unregister_sysctl(l4proto->ctl_table_header,
	267	l4proto->ctl_table,
	268	l4proto->ctl_table_users);
	269	}
	270	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
	271	out:
933a41e7	272	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	273	return err;
	274	}
	275
	276	static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
	277	{
	278	#ifdef CONFIG_SYSCTL
d62f9ed4 PM	279	if (l4proto->ctl_table_header != NULL &&
	280	*l4proto->ctl_table_header != NULL)
	281	nf_ct_unregister_sysctl(l4proto->ctl_table_header,
	282	l4proto->ctl_table,
	283	l4proto->ctl_table_users);
a999e683 PM	284	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	285	if (l4proto->ctl_compat_table_header != NULL)
	286	nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
	287	l4proto->ctl_compat_table, NULL);
	288	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
933a41e7	289	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	290	}
d62f9ed4 PM	291
8f03dea5 MJ	292	/* FIXME: Allow NULL functions and sub in pointers to generic for
8f03dea5 MJ	293	them. --RR */
605dcad6	294	int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
8f03dea5 MJ	295	{
	296	int ret = 0;
	297
0661cca9 PM	298	if (l4proto->l3proto >= PF_MAX)
0661cca9 PM	299	return -EBUSY;
ae5718fb	300
d0dba725 HE	301	if ((l4proto->to_nlattr && !l4proto->nlattr_size)
	302	\|\| (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
	303	return -EINVAL;
	304
b19caa0c	305	mutex_lock(&nf_ct_proto_mutex);
c6a1e615	306	if (!nf_ct_protos[l4proto->l3proto]) {
8f03dea5	307	/* l3proto may be loaded latter. */
c5d277d2	308	struct nf_conntrack_l4proto __rcu **proto_array;
8f03dea5 MJ	309	int i;
8f03dea5 MJ	310
c6a1e615 PM	311	proto_array = kmalloc(MAX_NF_CT_PROTO *
	312	sizeof(struct nf_conntrack_l4proto *),
	313	GFP_KERNEL);
8f03dea5 MJ	314	if (proto_array == NULL) {
8f03dea5 MJ	315	ret = -ENOMEM;
b19caa0c	316	goto out_unlock;
8f03dea5	317	}
c6a1e615	318
8f03dea5	319	for (i = 0; i < MAX_NF_CT_PROTO; i++)
c5d277d2	320	RCU_INIT_POINTER(proto_array[i], &nf_conntrack_l4proto_generic);
d817d29d ED	321
	322	/* Before making proto_array visible to lockless readers,
	323	* we must make sure its content is committed to memory.
	324	*/
	325	smp_wmb();
	326
c6a1e615	327	nf_ct_protos[l4proto->l3proto] = proto_array;
0e60ebe0 ED	328	} else if (rcu_dereference_protected(
	329	nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
	330	lockdep_is_held(&nf_ct_proto_mutex)
	331	) != &nf_conntrack_l4proto_generic) {
c6a1e615 PM	332	ret = -EBUSY;
c6a1e615 PM	333	goto out_unlock;
8f03dea5 MJ	334	}
8f03dea5 MJ	335
d62f9ed4 PM	336	ret = nf_ct_l4proto_register_sysctl(l4proto);
d62f9ed4 PM	337	if (ret < 0)
0661cca9 PM	338	goto out_unlock;
0661cca9 PM	339
d0dba725 HE	340	l4proto->nla_size = 0;
	341	if (l4proto->nlattr_size)
	342	l4proto->nla_size += l4proto->nlattr_size();
	343	if (l4proto->nlattr_tuple_size)
	344	l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
	345
c6a1e615 PM	346	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
c6a1e615 PM	347	l4proto);
8f03dea5 MJ	348
8f03dea5 MJ	349	out_unlock:
b19caa0c	350	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5 MJ	351	return ret;
8f03dea5 MJ	352	}
13b18339	353	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
8f03dea5	354
fe3eb20c	355	void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
8f03dea5	356	{
678d6675 AD	357	struct net *net;
678d6675 AD	358
fe3eb20c	359	BUG_ON(l4proto->l3proto >= PF_MAX);
ae5718fb	360
b19caa0c	361	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	362	BUG_ON(rcu_dereference_protected(
	363	nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
	364	lockdep_is_held(&nf_ct_proto_mutex)
	365	) != l4proto);
923f4902 PM	366	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
923f4902 PM	367	&nf_conntrack_l4proto_generic);
0661cca9	368	nf_ct_l4proto_unregister_sysctl(l4proto);
b19caa0c	369	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	370
0661cca9	371	synchronize_rcu();
d62f9ed4	372
8f03dea5	373	/* Remove all contrack entries for this protocol */
efb9a8c2	374	rtnl_lock();
678d6675 AD	375	for_each_net(net)
678d6675 AD	376	nf_ct_iterate_cleanup(net, kill_l4proto, l4proto);
efb9a8c2	377	rtnl_unlock();
8f03dea5	378	}
13b18339	379	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
ac5357eb PM	380
	381	int nf_conntrack_proto_init(void)
	382	{
	383	unsigned int i;
	384	int err;
	385
	386	err = nf_ct_l4proto_register_sysctl(&nf_conntrack_l4proto_generic);
	387	if (err < 0)
	388	return err;
	389
	390	for (i = 0; i < AF_MAX; i++)
	391	rcu_assign_pointer(nf_ct_l3protos[i],
	392	&nf_conntrack_l3proto_generic);
	393	return 0;
	394	}
	395
	396	void nf_conntrack_proto_fini(void)
	397	{
	398	unsigned int i;
	399
	400	nf_ct_l4proto_unregister_sysctl(&nf_conntrack_l4proto_generic);
	401
	402	/* free l3proto protocol tables */
	403	for (i = 0; i < PF_MAX; i++)
	404	kfree(nf_ct_protos[i]);
	405	}