[deliverable/linux.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[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 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 >= 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);

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;
}

int nf_ct_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;
	}

	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);

int nf_ct_l3proto_pernet_register(struct net *net,
				  struct nf_conntrack_l3proto *proto)
{
	int ret;

	if (proto->init_net) {
		ret = proto->init_net(net);
		if (ret < 0)
			return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register);

void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto)
{
	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);
	mutex_unlock(&nf_ct_proto_mutex);

	synchronize_rcu();
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);

void nf_ct_l3proto_pernet_unregister(struct net *net,
				     struct nf_conntrack_l3proto *proto)
{
	/* Remove all contrack entries for this protocol */
	nf_ct_iterate_cleanup(net, kill_l3proto, proto, 0, 0);
}
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(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;
	}

	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);

int nf_ct_l4proto_pernet_register(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);

void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
{
	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);
	mutex_unlock(&nf_ct_proto_mutex);

	synchronize_rcu();
}
EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);

void nf_ct_l4proto_pernet_unregister(struct net *net,
				     struct nf_conntrack_l4proto *l4proto)
{
	struct nf_proto_net *pn = NULL;

	pn = nf_ct_l4proto_net(net, l4proto);
	if (pn == NULL)
		return;

	pn->users--;
	nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);

	/* Remove all contrack entries for this protocol */
	nf_ct_iterate_cleanup(net, kill_l4proto, l4proto, 0, 0);
}
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 < 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;
	/* 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>
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
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
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 MJ	70	{
8f03dea5 MJ	71	if (unlikely(l3proto >= AF_MAX \|\| 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
c1ebd7df PNA	128	struct nf_conntrack_l4proto *
	129	nf_ct_l4proto_find_get(u_int16_t l3num, u_int8_t l4num)
	130	{
	131	struct nf_conntrack_l4proto *p;
	132
	133	rcu_read_lock();
	134	p = __nf_ct_l4proto_find(l3num, l4num);
	135	if (!try_module_get(p->me))
	136	p = &nf_conntrack_l4proto_generic;
	137	rcu_read_unlock();
	138
	139	return p;
	140	}
	141	EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
	142
	143	void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
	144	{
	145	module_put(p->me);
	146	}
	147	EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
	148
8f03dea5 MJ	149	static int kill_l3proto(struct nf_conn i, void data)
8f03dea5 MJ	150	{
5e8fbe2a	151	return nf_ct_l3num(i) == ((struct nf_conntrack_l3proto *)data)->l3proto;
8f03dea5 MJ	152	}
8f03dea5 MJ	153
605dcad6	154	static int kill_l4proto(struct nf_conn i, void data)
8f03dea5	155	{
605dcad6 MJ	156	struct nf_conntrack_l4proto *l4proto;
605dcad6 MJ	157	l4proto = (struct nf_conntrack_l4proto *)data;
5e8fbe2a PM	158	return nf_ct_protonum(i) == l4proto->l4proto &&
5e8fbe2a PM	159	nf_ct_l3num(i) == l4proto->l3proto;
8f03dea5 MJ	160	}
8f03dea5 MJ	161
6330750d	162	int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)
8f03dea5 MJ	163	{
8f03dea5 MJ	164	int ret = 0;
0e60ebe0	165	struct nf_conntrack_l3proto *old;
8f03dea5	166
0661cca9 PM	167	if (proto->l3proto >= AF_MAX)
0661cca9 PM	168	return -EBUSY;
ae5718fb	169
d0dba725 HE	170	if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
	171	return -EINVAL;
	172
b19caa0c	173	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	174	old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
	175	lockdep_is_held(&nf_ct_proto_mutex));
	176	if (old != &nf_conntrack_l3proto_generic) {
8f03dea5	177	ret = -EBUSY;
ae5718fb	178	goto out_unlock;
8f03dea5	179	}
d62f9ed4	180
d0dba725 HE	181	if (proto->nlattr_tuple_size)
	182	proto->nla_size = 3 * proto->nlattr_tuple_size();
	183
0661cca9	184	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
8f03dea5	185
ae5718fb	186	out_unlock:
b19caa0c	187	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	188	return ret;
524a53e5	189
8f03dea5	190	}
6330750d	191	EXPORT_SYMBOL_GPL(nf_ct_l3proto_register);
8f03dea5	192
6330750d	193	int nf_ct_l3proto_pernet_register(struct net *net,
524a53e5	194	struct nf_conntrack_l3proto *proto)
8f03dea5	195	{
adf05168	196	int ret;
524a53e5	197
fa0f61f0 G	198	if (proto->init_net) {
	199	ret = proto->init_net(net);
	200	if (ret < 0)
	201	return ret;
	202	}
524a53e5	203
adf05168	204	return 0;
524a53e5	205	}
6330750d	206	EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_register);
678d6675	207
6330750d	208	void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto)
524a53e5	209	{
fe3eb20c	210	BUG_ON(proto->l3proto >= AF_MAX);
ae5718fb	211
b19caa0c	212	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	213	BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
	214	lockdep_is_held(&nf_ct_proto_mutex)
	215	) != proto);
923f4902 PM	216	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
923f4902 PM	217	&nf_conntrack_l3proto_generic);
b19caa0c	218	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	219
0661cca9	220	synchronize_rcu();
524a53e5	221	}
6330750d	222	EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
524a53e5	223
6330750d	224	void nf_ct_l3proto_pernet_unregister(struct net *net,
524a53e5 G	225	struct nf_conntrack_l3proto *proto)
524a53e5 G	226	{
8f03dea5	227	/* Remove all contrack entries for this protocol */
c655bc68	228	nf_ct_iterate_cleanup(net, kill_l3proto, proto, 0, 0);
8f03dea5	229	}
6330750d	230	EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister);
8f03dea5	231
2c352f44 G	232	static struct nf_proto_net nf_ct_l4proto_net(struct net net,
	233	struct nf_conntrack_l4proto *l4proto)
	234	{
08911475 PNA	235	if (l4proto->get_net_proto) {
	236	/* statically built-in protocols use static per-net */
	237	return l4proto->get_net_proto(net);
	238	} else if (l4proto->net_id) {
	239	/* ... and loadable protocols use dynamic per-net */
	240	return net_generic(net, *l4proto->net_id);
15f585bd G	241	}
15f585bd G	242	return NULL;
2c352f44 G	243	}
	244
	245	static
	246	int nf_ct_l4proto_register_sysctl(struct net *net,
fa34fff5	247	struct nf_proto_net *pn,
2c352f44	248	struct nf_conntrack_l4proto *l4proto)
d62f9ed4 PM	249	{
	250	int err = 0;
	251
	252	#ifdef CONFIG_SYSCTL
2c352f44 G	253	if (pn->ctl_table != NULL) {
	254	err = nf_ct_register_sysctl(net,
	255	&pn->ctl_table_header,
f99e8f71	256	"net/netfilter",
fa34fff5	257	pn->ctl_table);
2c352f44 G	258	if (err < 0) {
	259	if (!pn->users) {
	260	kfree(pn->ctl_table);
	261	pn->ctl_table = NULL;
	262	}
2c352f44	263	}
d62f9ed4	264	}
933a41e7	265	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	266	return err;
	267	}
	268
2c352f44 G	269	static
2c352f44 G	270	void nf_ct_l4proto_unregister_sysctl(struct net *net,
fa34fff5	271	struct nf_proto_net *pn,
2c352f44	272	struct nf_conntrack_l4proto *l4proto)
d62f9ed4 PM	273	{
d62f9ed4 PM	274	#ifdef CONFIG_SYSCTL
2c352f44 G	275	if (pn->ctl_table_header != NULL)
	276	nf_ct_unregister_sysctl(&pn->ctl_table_header,
	277	&pn->ctl_table,
fa34fff5	278	pn->users);
933a41e7	279	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	280	}
d62f9ed4 PM	281
8f03dea5 MJ	282	/* FIXME: Allow NULL functions and sub in pointers to generic for
8f03dea5 MJ	283	them. --RR */
c296bb4d	284	int nf_ct_l4proto_register(struct nf_conntrack_l4proto *l4proto)
8f03dea5 MJ	285	{
	286	int ret = 0;
	287
0661cca9 PM	288	if (l4proto->l3proto >= PF_MAX)
0661cca9 PM	289	return -EBUSY;
ae5718fb	290
d0dba725 HE	291	if ((l4proto->to_nlattr && !l4proto->nlattr_size)
	292	\|\| (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size))
	293	return -EINVAL;
	294
b19caa0c	295	mutex_lock(&nf_ct_proto_mutex);
c6a1e615	296	if (!nf_ct_protos[l4proto->l3proto]) {
8f03dea5	297	/* l3proto may be loaded latter. */
c5d277d2	298	struct nf_conntrack_l4proto __rcu **proto_array;
8f03dea5 MJ	299	int i;
8f03dea5 MJ	300
c6a1e615 PM	301	proto_array = kmalloc(MAX_NF_CT_PROTO *
	302	sizeof(struct nf_conntrack_l4proto *),
	303	GFP_KERNEL);
8f03dea5 MJ	304	if (proto_array == NULL) {
8f03dea5 MJ	305	ret = -ENOMEM;
b19caa0c	306	goto out_unlock;
8f03dea5	307	}
c6a1e615	308
8f03dea5	309	for (i = 0; i < MAX_NF_CT_PROTO; i++)
c5d277d2	310	RCU_INIT_POINTER(proto_array[i], &nf_conntrack_l4proto_generic);
d817d29d ED	311
	312	/* Before making proto_array visible to lockless readers,
	313	* we must make sure its content is committed to memory.
	314	*/
	315	smp_wmb();
	316
c6a1e615	317	nf_ct_protos[l4proto->l3proto] = proto_array;
0e60ebe0 ED	318	} else if (rcu_dereference_protected(
	319	nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
	320	lockdep_is_held(&nf_ct_proto_mutex)
	321	) != &nf_conntrack_l4proto_generic) {
c6a1e615 PM	322	ret = -EBUSY;
c6a1e615 PM	323	goto out_unlock;
8f03dea5 MJ	324	}
8f03dea5 MJ	325
d0dba725 HE	326	l4proto->nla_size = 0;
	327	if (l4proto->nlattr_size)
	328	l4proto->nla_size += l4proto->nlattr_size();
	329	if (l4proto->nlattr_tuple_size)
	330	l4proto->nla_size += 3 * l4proto->nlattr_tuple_size();
	331
c6a1e615 PM	332	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
c6a1e615 PM	333	l4proto);
8f03dea5	334	out_unlock:
b19caa0c	335	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5 MJ	336	return ret;
8f03dea5 MJ	337	}
c296bb4d	338	EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);
8f03dea5	339
c296bb4d	340	int nf_ct_l4proto_pernet_register(struct net *net,
2c352f44	341	struct nf_conntrack_l4proto *l4proto)
8f03dea5	342	{
2c352f44	343	int ret = 0;
fa34fff5	344	struct nf_proto_net *pn = NULL;
2c352f44	345
fa0f61f0	346	if (l4proto->init_net) {
f1caad27	347	ret = l4proto->init_net(net, l4proto->l3proto);
fa0f61f0	348	if (ret < 0)
fa34fff5	349	goto out;
fa0f61f0	350	}
678d6675	351
fa34fff5 G	352	pn = nf_ct_l4proto_net(net, l4proto);
	353	if (pn == NULL)
	354	goto out;
	355
	356	ret = nf_ct_l4proto_register_sysctl(net, pn, l4proto);
2c352f44	357	if (ret < 0)
fa34fff5	358	goto out;
2c352f44	359
fa34fff5 G	360	pn->users++;
fa34fff5 G	361	out:
fa0f61f0	362	return ret;
2c352f44	363	}
c296bb4d	364	EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register);
2c352f44	365
c296bb4d	366	void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
2c352f44	367	{
fe3eb20c	368	BUG_ON(l4proto->l3proto >= PF_MAX);
ae5718fb	369
b19caa0c	370	mutex_lock(&nf_ct_proto_mutex);
0e60ebe0 ED	371	BUG_ON(rcu_dereference_protected(
	372	nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
	373	lockdep_is_held(&nf_ct_proto_mutex)
	374	) != l4proto);
923f4902 PM	375	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
923f4902 PM	376	&nf_conntrack_l4proto_generic);
b19caa0c	377	mutex_unlock(&nf_ct_proto_mutex);
8f03dea5	378
0661cca9	379	synchronize_rcu();
2c352f44	380	}
c296bb4d	381	EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);
d62f9ed4	382
c296bb4d	383	void nf_ct_l4proto_pernet_unregister(struct net *net,
2c352f44 G	384	struct nf_conntrack_l4proto *l4proto)
2c352f44 G	385	{
fa34fff5 G	386	struct nf_proto_net *pn = NULL;
fa34fff5 G	387
fa34fff5 G	388	pn = nf_ct_l4proto_net(net, l4proto);
	389	if (pn == NULL)
	390	return;
	391
	392	pn->users--;
	393	nf_ct_l4proto_unregister_sysctl(net, pn, l4proto);
	394
8f03dea5	395	/* Remove all contrack entries for this protocol */
c655bc68	396	nf_ct_iterate_cleanup(net, kill_l4proto, l4proto, 0, 0);
8f03dea5	397	}
c296bb4d	398	EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_unregister);
ac5357eb	399
04d87001	400	int nf_conntrack_proto_pernet_init(struct net *net)
ac5357eb	401	{
ac5357eb	402	int err;
fa34fff5 G	403	struct nf_proto_net *pn = nf_ct_l4proto_net(net,
	404	&nf_conntrack_l4proto_generic);
	405
f1caad27 G	406	err = nf_conntrack_l4proto_generic.init_net(net,
f1caad27 G	407	nf_conntrack_l4proto_generic.l3proto);
15f585bd G	408	if (err < 0)
	409	return err;
	410	err = nf_ct_l4proto_register_sysctl(net,
fa34fff5	411	pn,
15f585bd	412	&nf_conntrack_l4proto_generic);
ac5357eb PM	413	if (err < 0)
	414	return err;
	415
fa34fff5	416	pn->users++;
ac5357eb PM	417	return 0;
	418	}
	419
04d87001	420	void nf_conntrack_proto_pernet_fini(struct net *net)
ac5357eb	421	{
fa34fff5 G	422	struct nf_proto_net *pn = nf_ct_l4proto_net(net,
	423	&nf_conntrack_l4proto_generic);
	424
	425	pn->users--;
15f585bd	426	nf_ct_l4proto_unregister_sysctl(net,
fa34fff5	427	pn,
15f585bd	428	&nf_conntrack_l4proto_generic);
04d87001 G	429	}
	430
	431	int nf_conntrack_proto_init(void)
	432	{
	433	unsigned int i;
	434	for (i = 0; i < AF_MAX; i++)
	435	rcu_assign_pointer(nf_ct_l3protos[i],
	436	&nf_conntrack_l3proto_generic);
	437	return 0;
	438	}
	439
	440	void nf_conntrack_proto_fini(void)
	441	{
	442	unsigned int i;
	443	/* free l3proto protocol tables */
	444	for (i = 0; i < PF_MAX; i++)
	445	kfree(nf_ct_protos[i]);
ac5357eb	446	}