[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>
 *
 * 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/mutex.h>
#include <linux/skbuff.h>
#include <linux/vmalloc.h>
#include <linux/stddef.h>
#include <linux/err.h>
#include <linux/percpu.h>
#include <linux/moduleparam.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>

struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
EXPORT_SYMBOL_GPL(nf_ct_l3protos);

#ifdef CONFIG_SYSCTL
static DEFINE_MUTEX(nf_ct_proto_sysctl_mutex);

static int
nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_table *path,
		      struct ctl_table *table, unsigned int *users)
{
	if (*header == NULL) {
		*header = nf_register_sysctl_table(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;
	nf_unregister_sysctl_table(*header, table);
	*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_l4proto *
nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto)
{
	struct nf_conntrack_l4proto *p;

	rcu_read_lock();
	p = __nf_ct_l4proto_find(l3proto, l4proto);
	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);

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 */
	p = __nf_ct_l3proto_find(l3proto);
	module_put(p->me);
}
EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);

static int kill_l3proto(struct nf_conn *i, void *data)
{
	return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
			((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 (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum ==
			l4proto->l4proto) &&
	       (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
			l4proto->l3proto);
}

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

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

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

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

	if (proto->l3proto >= AF_MAX) {
		ret = -EBUSY;
		goto out;
	}

	write_lock_bh(&nf_conntrack_lock);
	if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
		ret = -EBUSY;
		goto out_unlock;
	}
	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
	write_unlock_bh(&nf_conntrack_lock);

	ret = nf_ct_l3proto_register_sysctl(proto);
	if (ret < 0)
		nf_conntrack_l3proto_unregister(proto);
	return ret;

out_unlock:
	write_unlock_bh(&nf_conntrack_lock);
out:
	return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);

void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
{
	BUG_ON(proto->l3proto >= AF_MAX);

	write_lock_bh(&nf_conntrack_lock);
	BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
			   &nf_conntrack_l3proto_generic);
	write_unlock_bh(&nf_conntrack_lock);
	synchronize_rcu();

	nf_ct_l3proto_unregister_sysctl(proto);

	/* Remove all contrack entries for this protocol */
	nf_ct_iterate_cleanup(kill_l3proto, proto);
}
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
	mutex_lock(&nf_ct_proto_sysctl_mutex);
	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:
	mutex_unlock(&nf_ct_proto_sysctl_mutex);
#endif /* CONFIG_SYSCTL */
	return err;
}

static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
{
#ifdef CONFIG_SYSCTL
	mutex_lock(&nf_ct_proto_sysctl_mutex);
	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 */
	mutex_unlock(&nf_ct_proto_sysctl_mutex);
#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) {
		ret = -EBUSY;
		goto out;
	}

	if (l4proto == &nf_conntrack_l4proto_generic)
		return nf_ct_l4proto_register_sysctl(l4proto);

retry:
	write_lock_bh(&nf_conntrack_lock);
	if (nf_ct_protos[l4proto->l3proto]) {
		if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
				!= &nf_conntrack_l4proto_generic) {
			ret = -EBUSY;
			goto out_unlock;
		}
	} else {
		/* l3proto may be loaded latter. */
		struct nf_conntrack_l4proto **proto_array;
		int i;

		write_unlock_bh(&nf_conntrack_lock);

		proto_array = (struct nf_conntrack_l4proto **)
				kmalloc(MAX_NF_CT_PROTO *
					 sizeof(struct nf_conntrack_l4proto *),
					GFP_KERNEL);
		if (proto_array == NULL) {
			ret = -ENOMEM;
			goto out;
		}
		for (i = 0; i < MAX_NF_CT_PROTO; i++)
			proto_array[i] = &nf_conntrack_l4proto_generic;

		write_lock_bh(&nf_conntrack_lock);
		if (nf_ct_protos[l4proto->l3proto]) {
			/* bad timing, but no problem */
			write_unlock_bh(&nf_conntrack_lock);
			kfree(proto_array);
		} else {
			nf_ct_protos[l4proto->l3proto] = proto_array;
			write_unlock_bh(&nf_conntrack_lock);
		}

		/*
		 * Just once because array is never freed until unloading
		 * nf_conntrack.ko
		 */
		goto retry;
	}

	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], l4proto);
	write_unlock_bh(&nf_conntrack_lock);

	ret = nf_ct_l4proto_register_sysctl(l4proto);
	if (ret < 0)
		nf_conntrack_l4proto_unregister(l4proto);
	return ret;

out_unlock:
	write_unlock_bh(&nf_conntrack_lock);
out:
	return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);

void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
{
	BUG_ON(l4proto->l3proto >= PF_MAX);

	if (l4proto == &nf_conntrack_l4proto_generic) {
		nf_ct_l4proto_unregister_sysctl(l4proto);
		return;
	}

	write_lock_bh(&nf_conntrack_lock);
	BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
			   &nf_conntrack_l4proto_generic);
	write_unlock_bh(&nf_conntrack_lock);
	synchronize_rcu();

	nf_ct_l4proto_unregister_sysctl(l4proto);

	/* Remove all contrack entries for this protocol */
	nf_ct_iterate_cleanup(kill_l4proto, l4proto);
}
EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
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>
d62f9ed4	15	#include <linux/mutex.h>
8f03dea5 MJ	16	#include <linux/skbuff.h>
	17	#include <linux/vmalloc.h>
	18	#include <linux/stddef.h>
	19	#include <linux/err.h>
	20	#include <linux/percpu.h>
	21	#include <linux/moduleparam.h>
	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
605dcad6	31	struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
ae5718fb	32	struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
13b18339	33	EXPORT_SYMBOL_GPL(nf_ct_l3protos);
8f03dea5	34
d62f9ed4 PM	35	#ifdef CONFIG_SYSCTL
	36	static DEFINE_MUTEX(nf_ct_proto_sysctl_mutex);
	37
	38	static int
	39	nf_ct_register_sysctl(struct ctl_table_header *header, struct ctl_table path,
	40	struct ctl_table table, unsigned int users)
	41	{
	42	if (*header == NULL) {
	43	*header = nf_register_sysctl_table(path, table);
	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;
	58	nf_unregister_sysctl_table(*header, table);
	59	*header = NULL;
	60	}
	61	#endif
	62
605dcad6 MJ	63	struct nf_conntrack_l4proto *
605dcad6 MJ	64	__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
8f03dea5 MJ	65	{
8f03dea5 MJ	66	if (unlikely(l3proto >= AF_MAX \|\| nf_ct_protos[l3proto] == NULL))
605dcad6	67	return &nf_conntrack_l4proto_generic;
8f03dea5	68
923f4902	69	return rcu_dereference(nf_ct_protos[l3proto][l4proto]);
8f03dea5	70	}
13b18339	71	EXPORT_SYMBOL_GPL(__nf_ct_l4proto_find);
8f03dea5 MJ	72
	73	/* this is guaranteed to always return a valid protocol helper, since
	74	* it falls back to generic_protocol */
605dcad6 MJ	75	struct nf_conntrack_l4proto *
605dcad6 MJ	76	nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto)
8f03dea5	77	{
605dcad6	78	struct nf_conntrack_l4proto *p;
8f03dea5	79
923f4902	80	rcu_read_lock();
605dcad6	81	p = __nf_ct_l4proto_find(l3proto, l4proto);
8f03dea5	82	if (!try_module_get(p->me))
605dcad6	83	p = &nf_conntrack_l4proto_generic;
923f4902	84	rcu_read_unlock();
8f03dea5 MJ	85
	86	return p;
	87	}
13b18339	88	EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
8f03dea5	89
605dcad6	90	void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
8f03dea5 MJ	91	{
	92	module_put(p->me);
	93	}
13b18339	94	EXPORT_SYMBOL_GPL(nf_ct_l4proto_put);
8f03dea5 MJ	95
	96	struct nf_conntrack_l3proto *
	97	nf_ct_l3proto_find_get(u_int16_t l3proto)
	98	{
	99	struct nf_conntrack_l3proto *p;
	100
923f4902	101	rcu_read_lock();
8f03dea5 MJ	102	p = __nf_ct_l3proto_find(l3proto);
8f03dea5 MJ	103	if (!try_module_get(p->me))
605dcad6	104	p = &nf_conntrack_l3proto_generic;
923f4902	105	rcu_read_unlock();
8f03dea5 MJ	106
	107	return p;
	108	}
13b18339	109	EXPORT_SYMBOL_GPL(nf_ct_l3proto_find_get);
8f03dea5 MJ	110
	111	void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p)
	112	{
	113	module_put(p->me);
	114	}
13b18339	115	EXPORT_SYMBOL_GPL(nf_ct_l3proto_put);
8f03dea5 MJ	116
	117	int
	118	nf_ct_l3proto_try_module_get(unsigned short l3proto)
	119	{
	120	int ret;
	121	struct nf_conntrack_l3proto *p;
	122
	123	retry: p = nf_ct_l3proto_find_get(l3proto);
605dcad6	124	if (p == &nf_conntrack_l3proto_generic) {
8f03dea5 MJ	125	ret = request_module("nf_conntrack-%d", l3proto);
	126	if (!ret)
	127	goto retry;
	128
	129	return -EPROTOTYPE;
	130	}
	131
	132	return 0;
	133	}
13b18339	134	EXPORT_SYMBOL_GPL(nf_ct_l3proto_try_module_get);
8f03dea5 MJ	135
	136	void nf_ct_l3proto_module_put(unsigned short l3proto)
	137	{
	138	struct nf_conntrack_l3proto *p;
	139
923f4902	140	/* rcu_read_lock not necessary since the caller holds a reference */
8f03dea5	141	p = __nf_ct_l3proto_find(l3proto);
8f03dea5 MJ	142	module_put(p->me);
8f03dea5 MJ	143	}
13b18339	144	EXPORT_SYMBOL_GPL(nf_ct_l3proto_module_put);
8f03dea5 MJ	145
	146	static int kill_l3proto(struct nf_conn i, void data)
	147	{
	148	return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
	149	((struct nf_conntrack_l3proto *)data)->l3proto);
	150	}
	151
605dcad6	152	static int kill_l4proto(struct nf_conn i, void data)
8f03dea5	153	{
605dcad6 MJ	154	struct nf_conntrack_l4proto *l4proto;
605dcad6 MJ	155	l4proto = (struct nf_conntrack_l4proto *)data;
8f03dea5	156	return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum ==
605dcad6	157	l4proto->l4proto) &&
8f03dea5	158	(i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num ==
605dcad6	159	l4proto->l3proto);
8f03dea5 MJ	160	}
8f03dea5 MJ	161
d62f9ed4 PM	162	static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
	163	{
	164	int err = 0;
	165
	166	#ifdef CONFIG_SYSCTL
	167	mutex_lock(&nf_ct_proto_sysctl_mutex);
	168	if (l3proto->ctl_table != NULL) {
	169	err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
	170	l3proto->ctl_table_path,
	171	l3proto->ctl_table, NULL);
	172	}
	173	mutex_unlock(&nf_ct_proto_sysctl_mutex);
	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
	181	mutex_lock(&nf_ct_proto_sysctl_mutex);
	182	if (l3proto->ctl_table_header != NULL)
	183	nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
	184	l3proto->ctl_table, NULL);
	185	mutex_unlock(&nf_ct_proto_sysctl_mutex);
	186	#endif
	187	}
	188
8f03dea5 MJ	189	int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
	190	{
	191	int ret = 0;
	192
ae5718fb MJ	193	if (proto->l3proto >= AF_MAX) {
	194	ret = -EBUSY;
	195	goto out;
	196	}
	197
8f03dea5	198	write_lock_bh(&nf_conntrack_lock);
605dcad6	199	if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
8f03dea5	200	ret = -EBUSY;
ae5718fb	201	goto out_unlock;
8f03dea5	202	}
923f4902	203	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);
d62f9ed4 PM	204	write_unlock_bh(&nf_conntrack_lock);
	205
	206	ret = nf_ct_l3proto_register_sysctl(proto);
	207	if (ret < 0)
	208	nf_conntrack_l3proto_unregister(proto);
	209	return ret;
8f03dea5	210
ae5718fb MJ	211	out_unlock:
	212	write_unlock_bh(&nf_conntrack_lock);
	213	out:
8f03dea5 MJ	214	return ret;
8f03dea5 MJ	215	}
13b18339	216	EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_register);
8f03dea5	217
fe3eb20c	218	void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
8f03dea5	219	{
fe3eb20c	220	BUG_ON(proto->l3proto >= AF_MAX);
ae5718fb	221
8f03dea5	222	write_lock_bh(&nf_conntrack_lock);
fe3eb20c	223	BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
923f4902 PM	224	rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
923f4902 PM	225	&nf_conntrack_l3proto_generic);
8f03dea5	226	write_unlock_bh(&nf_conntrack_lock);
923f4902	227	synchronize_rcu();
8f03dea5	228
d62f9ed4 PM	229	nf_ct_l3proto_unregister_sysctl(proto);
d62f9ed4 PM	230
8f03dea5 MJ	231	/* Remove all contrack entries for this protocol */
	232	nf_ct_iterate_cleanup(kill_l3proto, proto);
	233	}
13b18339	234	EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
8f03dea5	235
d62f9ed4 PM	236	static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
	237	{
	238	int err = 0;
	239
	240	#ifdef CONFIG_SYSCTL
	241	mutex_lock(&nf_ct_proto_sysctl_mutex);
	242	if (l4proto->ctl_table != NULL) {
	243	err = nf_ct_register_sysctl(l4proto->ctl_table_header,
	244	nf_net_netfilter_sysctl_path,
	245	l4proto->ctl_table,
	246	l4proto->ctl_table_users);
a999e683 PM	247	if (err < 0)
a999e683 PM	248	goto out;
d62f9ed4	249	}
a999e683 PM	250	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	251	if (l4proto->ctl_compat_table != NULL) {
	252	err = nf_ct_register_sysctl(&l4proto->ctl_compat_table_header,
	253	nf_net_ipv4_netfilter_sysctl_path,
	254	l4proto->ctl_compat_table, NULL);
	255	if (err == 0)
	256	goto out;
	257	nf_ct_unregister_sysctl(l4proto->ctl_table_header,
	258	l4proto->ctl_table,
	259	l4proto->ctl_table_users);
	260	}
	261	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
	262	out:
d62f9ed4	263	mutex_unlock(&nf_ct_proto_sysctl_mutex);
933a41e7	264	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	265	return err;
	266	}
	267
	268	static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
	269	{
	270	#ifdef CONFIG_SYSCTL
	271	mutex_lock(&nf_ct_proto_sysctl_mutex);
	272	if (l4proto->ctl_table_header != NULL &&
	273	*l4proto->ctl_table_header != NULL)
	274	nf_ct_unregister_sysctl(l4proto->ctl_table_header,
	275	l4proto->ctl_table,
	276	l4proto->ctl_table_users);
a999e683 PM	277	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	278	if (l4proto->ctl_compat_table_header != NULL)
	279	nf_ct_unregister_sysctl(&l4proto->ctl_compat_table_header,
	280	l4proto->ctl_compat_table, NULL);
	281	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
d62f9ed4	282	mutex_unlock(&nf_ct_proto_sysctl_mutex);
933a41e7	283	#endif /* CONFIG_SYSCTL */
d62f9ed4 PM	284	}
d62f9ed4 PM	285
8f03dea5 MJ	286	/* FIXME: Allow NULL functions and sub in pointers to generic for
8f03dea5 MJ	287	them. --RR */
605dcad6	288	int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
8f03dea5 MJ	289	{
	290	int ret = 0;
	291
ae5718fb MJ	292	if (l4proto->l3proto >= PF_MAX) {
	293	ret = -EBUSY;
	294	goto out;
	295	}
	296
933a41e7 PM	297	if (l4proto == &nf_conntrack_l4proto_generic)
	298	return nf_ct_l4proto_register_sysctl(l4proto);
	299
8f03dea5 MJ	300	retry:
8f03dea5 MJ	301	write_lock_bh(&nf_conntrack_lock);
605dcad6 MJ	302	if (nf_ct_protos[l4proto->l3proto]) {
	303	if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto]
	304	!= &nf_conntrack_l4proto_generic) {
8f03dea5 MJ	305	ret = -EBUSY;
	306	goto out_unlock;
	307	}
	308	} else {
	309	/* l3proto may be loaded latter. */
605dcad6	310	struct nf_conntrack_l4proto **proto_array;
8f03dea5 MJ	311	int i;
	312
	313	write_unlock_bh(&nf_conntrack_lock);
	314
605dcad6	315	proto_array = (struct nf_conntrack_l4proto **)
8f03dea5	316	kmalloc(MAX_NF_CT_PROTO *
605dcad6	317	sizeof(struct nf_conntrack_l4proto *),
8f03dea5 MJ	318	GFP_KERNEL);
	319	if (proto_array == NULL) {
	320	ret = -ENOMEM;
	321	goto out;
	322	}
	323	for (i = 0; i < MAX_NF_CT_PROTO; i++)
605dcad6	324	proto_array[i] = &nf_conntrack_l4proto_generic;
8f03dea5 MJ	325
8f03dea5 MJ	326	write_lock_bh(&nf_conntrack_lock);
605dcad6	327	if (nf_ct_protos[l4proto->l3proto]) {
8f03dea5 MJ	328	/* bad timing, but no problem */
	329	write_unlock_bh(&nf_conntrack_lock);
	330	kfree(proto_array);
	331	} else {
605dcad6	332	nf_ct_protos[l4proto->l3proto] = proto_array;
8f03dea5 MJ	333	write_unlock_bh(&nf_conntrack_lock);
	334	}
	335
	336	/*
	337	* Just once because array is never freed until unloading
	338	* nf_conntrack.ko
	339	*/
	340	goto retry;
	341	}
	342
923f4902	343	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], l4proto);
d62f9ed4 PM	344	write_unlock_bh(&nf_conntrack_lock);
	345
	346	ret = nf_ct_l4proto_register_sysctl(l4proto);
	347	if (ret < 0)
	348	nf_conntrack_l4proto_unregister(l4proto);
	349	return ret;
8f03dea5 MJ	350
	351	out_unlock:
	352	write_unlock_bh(&nf_conntrack_lock);
	353	out:
	354	return ret;
	355	}
13b18339	356	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_register);
8f03dea5	357
fe3eb20c	358	void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
8f03dea5	359	{
fe3eb20c	360	BUG_ON(l4proto->l3proto >= PF_MAX);
ae5718fb	361
933a41e7 PM	362	if (l4proto == &nf_conntrack_l4proto_generic) {
933a41e7 PM	363	nf_ct_l4proto_unregister_sysctl(l4proto);
fe3eb20c	364	return;
933a41e7 PM	365	}
933a41e7 PM	366
8f03dea5	367	write_lock_bh(&nf_conntrack_lock);
fe3eb20c	368	BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
923f4902 PM	369	rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
923f4902 PM	370	&nf_conntrack_l4proto_generic);
8f03dea5	371	write_unlock_bh(&nf_conntrack_lock);
923f4902	372	synchronize_rcu();
8f03dea5	373
d62f9ed4 PM	374	nf_ct_l4proto_unregister_sysctl(l4proto);
d62f9ed4 PM	375
8f03dea5	376	/* Remove all contrack entries for this protocol */
605dcad6	377	nf_ct_iterate_cleanup(kill_l4proto, l4proto);
8f03dea5	378	}
13b18339	379	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);