[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / protocol.c

/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		INET protocol dispatch tables.
 *
 * Authors:	Ross Biro
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *
 * Fixes:
 *		Alan Cox	: Ahah! udp icmp errors don't work because
 *				  udp_err is never called!
 *		Alan Cox	: Added new fields for init and ready for
 *				  proper fragmentation (_NO_ 4K limits!)
 *		Richard Colella	: Hang on hash collision
 *		Vince Laviano	: Modified inet_del_protocol() to correctly
 *				  maintain copy bit.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
#include <linux/cache.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <net/protocol.h>

const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;

/*
 *	Add a protocol handler to the hash tables
 */

int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
{
	if (!prot->netns_ok) {
		pr_err("Protocol %u is not namespace aware, cannot register.\n",
			protocol);
		return -EINVAL;
	}

	return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
			NULL, prot) ? 0 : -1;
}
EXPORT_SYMBOL(inet_add_protocol);

int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
{
	return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
			NULL, prot) ? 0 : -1;
}
EXPORT_SYMBOL(inet_add_offload);

/*
 *	Remove a protocol from the hash tables.
 */

int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
{
	int ret;

	ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
		       prot, NULL) == prot) ? 0 : -1;

	synchronize_net();

	return ret;
}
EXPORT_SYMBOL(inet_del_protocol);

int inet_del_offload(const struct net_offload *prot, unsigned char protocol)
{
	int ret;

	ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol],
		       prot, NULL) == prot) ? 0 : -1;

	synchronize_net();

	return ret;
}
EXPORT_SYMBOL(inet_del_offload);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* INET An implementation of the TCP/IP protocol suite for the LINUX
	3	* operating system. INET is implemented using the BSD Socket
	4	* interface as the means of communication with the user level.
	5	*
	6	* INET protocol dispatch tables.
	7	*
02c30a84	8	* Authors: Ross Biro
1da177e4 LT	9	* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
	10	*
	11	* Fixes:
	12	* Alan Cox : Ahah! udp icmp errors don't work because
	13	* udp_err is never called!
	14	* Alan Cox : Added new fields for init and ready for
	15	* proper fragmentation (_NO_ 4K limits!)
	16	* Richard Colella : Hang on hash collision
	17	* Vince Laviano : Modified inet_del_protocol() to correctly
	18	* maintain copy bit.
	19	*
	20	* This program is free software; you can redistribute it and/or
	21	* modify it under the terms of the GNU General Public License
	22	* as published by the Free Software Foundation; either version
	23	* 2 of the License, or (at your option) any later version.
	24	*/
fa1a9c68	25	#include <linux/cache.h>
1da177e4	26	#include <linux/module.h>
1da177e4	27	#include <linux/netdevice.h>
fa1a9c68	28	#include <linux/spinlock.h>
1da177e4	29	#include <net/protocol.h>
1da177e4	30
e0ad61ec	31	const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
de27d001	32	const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;
1da177e4 LT	33
	34	/*
	35	* Add a protocol handler to the hash tables
	36	*/
	37
32613090	38	int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
1da177e4	39	{
547472b8 DM	40	if (!prot->netns_ok) {
	41	pr_err("Protocol %u is not namespace aware, cannot register.\n",
	42	protocol);
	43	return -EINVAL;
	44	}
	45
f9242b6b	46	return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
e0ad61ec	47	NULL, prot) ? 0 : -1;
1da177e4	48	}
4bc2f18b	49	EXPORT_SYMBOL(inet_add_protocol);
1da177e4	50
de27d001 VY	51	int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
	52	{
	53	return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
	54	NULL, prot) ? 0 : -1;
	55	}
	56	EXPORT_SYMBOL(inet_add_offload);
	57
1da177e4 LT	58	/*
	59	* Remove a protocol from the hash tables.
	60	*/
e905a9ed	61
32613090	62	int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
1da177e4	63	{
f9242b6b	64	int ret;
1da177e4	65
f9242b6b	66	ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
e0ad61ec	67	prot, NULL) == prot) ? 0 : -1;
1da177e4 LT	68
	69	synchronize_net();
	70
	71	return ret;
	72	}
1da177e4	73	EXPORT_SYMBOL(inet_del_protocol);
de27d001 VY	74
	75	int inet_del_offload(const struct net_offload *prot, unsigned char protocol)
	76	{
	77	int ret;
	78
	79	ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol],
	80	prot, NULL) == prot) ? 0 : -1;
	81
	82	synchronize_net();
	83
	84	return ret;
	85	}
	86	EXPORT_SYMBOL(inet_del_offload);