[net-next-2.6.git] / net / tipc / user_reg.c

/*
 * net/tipc/user_reg.c: TIPC user registry code
 * 
 * Copyright (c) 2000-2006, Ericsson AB
 * Copyright (c) 2004-2005, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "core.h"
#include "user_reg.h"

/*
 * TIPC user registry keeps track of users of the tipc_port interface.
 *
 * The registry utilizes an array of "TIPC user" entries; 
 * a user's ID is the index of their associated array entry.
 * Array entry 0 is not used, so userid 0 is not valid;
 * TIPC sometimes uses this value to denote an anonymous user.
 * The list of free entries is initially chained from last entry to entry 1.
 */

/**
 * struct tipc_user - registered TIPC user info
 * @next: index of next free registry entry (or -1 for an allocated entry)
 * @callback: ptr to routine to call when TIPC mode changes (NULL if none)
 * @usr_handle: user-defined value passed to callback routine 
 * @ports: list of user ports owned by the user
 */

struct tipc_user {
	int next;
	tipc_mode_event callback;
	void *usr_handle;
	struct list_head ports;
};

#define MAX_USERID 64
#define USER_LIST_SIZE ((MAX_USERID + 1) * sizeof(struct tipc_user))

static struct tipc_user *users = NULL;
static u32 next_free_user = MAX_USERID + 1;
static DEFINE_SPINLOCK(reg_lock);

/**
 * reg_init - create TIPC user registry (but don't activate it)
 * 
 * If registry has been pre-initialized it is left "as is".
 * NOTE: This routine may be called when TIPC is inactive.
 */

static int reg_init(void)
{
	u32 i;
	
	spin_lock_bh(&reg_lock);
	if (!users) {
		users = (struct tipc_user *)kmalloc(USER_LIST_SIZE, GFP_ATOMIC);
		if (users) {
			memset(users, 0, USER_LIST_SIZE);
			for (i = 1; i <= MAX_USERID; i++) {
				users[i].next = i - 1;
			}
			next_free_user = MAX_USERID;
		}
	}
	spin_unlock_bh(&reg_lock);
	return users ? TIPC_OK : -ENOMEM;
}

/**
 * reg_callback - inform TIPC user about current operating mode
 */

static void reg_callback(struct tipc_user *user_ptr)
{
	tipc_mode_event cb;
	void *arg;

	spin_lock_bh(&reg_lock);
	cb = user_ptr->callback;
	arg = user_ptr->usr_handle;
	spin_unlock_bh(&reg_lock);

	if (cb)
		cb(arg, tipc_mode, tipc_own_addr);
}

/**
 * tipc_reg_start - activate TIPC user registry
 */

int tipc_reg_start(void)
{
	u32 u;
	int res;

	if ((res = reg_init()))
		return res;

	for (u = 1; u <= MAX_USERID; u++) {
		if (users[u].callback)
			tipc_k_signal((Handler)reg_callback,
				      (unsigned long)&users[u]);
	}
	return TIPC_OK;
}

/**
 * tipc_reg_stop - shut down & delete TIPC user registry
 */

void tipc_reg_stop(void)
{               
	int id;

	if (!users)
		return;

	for (id = 1; id <= MAX_USERID; id++) {
		if (users[id].callback)
			reg_callback(&users[id]);
	}
	kfree(users);
	users = NULL;
}

/**
 * tipc_attach - register a TIPC user
 *
 * NOTE: This routine may be called when TIPC is inactive.
 */

int tipc_attach(u32 *userid, tipc_mode_event cb, void *usr_handle)
{
	struct tipc_user *user_ptr;

	if ((tipc_mode == TIPC_NOT_RUNNING) && !cb)
		return -ENOPROTOOPT;
	if (!users)
		reg_init();

	spin_lock_bh(&reg_lock);
	if (!next_free_user) {
		spin_unlock_bh(&reg_lock);
		return -EBUSY;
	}
	user_ptr = &users[next_free_user];
	*userid = next_free_user;
	next_free_user = user_ptr->next;
	user_ptr->next = -1; 
	spin_unlock_bh(&reg_lock);

	user_ptr->callback = cb;
	user_ptr->usr_handle = usr_handle;
	INIT_LIST_HEAD(&user_ptr->ports);
	atomic_inc(&tipc_user_count);
	
	if (cb && (tipc_mode != TIPC_NOT_RUNNING))
		tipc_k_signal((Handler)reg_callback, (unsigned long)user_ptr);
	return TIPC_OK;
}

/**
 * tipc_detach - deregister a TIPC user
 */

void tipc_detach(u32 userid)
{
	struct tipc_user *user_ptr;
	struct list_head ports_temp;
	struct user_port *up_ptr, *temp_up_ptr;

	if ((userid == 0) || (userid > MAX_USERID))
		return;

	spin_lock_bh(&reg_lock);
	if ((!users) || (users[userid].next >= 0)) {
		spin_unlock_bh(&reg_lock);
		return;
	}

	user_ptr = &users[userid];
        user_ptr->callback = NULL;              
	INIT_LIST_HEAD(&ports_temp);
        list_splice(&user_ptr->ports, &ports_temp);
	user_ptr->next = next_free_user;
	next_free_user = userid;
	spin_unlock_bh(&reg_lock);

	atomic_dec(&tipc_user_count);

        list_for_each_entry_safe(up_ptr, temp_up_ptr, &ports_temp, uport_list) {
		tipc_deleteport(up_ptr->ref);
	}
}

/**
 * tipc_reg_add_port - register a user's driver port
 */

int tipc_reg_add_port(struct user_port *up_ptr)
{
	struct tipc_user *user_ptr;

	if (up_ptr->user_ref == 0)
		return TIPC_OK;
	if (up_ptr->user_ref > MAX_USERID)
		return -EINVAL;
	if ((tipc_mode == TIPC_NOT_RUNNING) || !users )
		return -ENOPROTOOPT;

	spin_lock_bh(&reg_lock);
	user_ptr = &users[up_ptr->user_ref];
	list_add(&up_ptr->uport_list, &user_ptr->ports);
	spin_unlock_bh(&reg_lock);
	return TIPC_OK;
}

/**
 * tipc_reg_remove_port - deregister a user's driver port
 */

int tipc_reg_remove_port(struct user_port *up_ptr)
{
	if (up_ptr->user_ref == 0)
		return TIPC_OK;
	if (up_ptr->user_ref > MAX_USERID)
		return -EINVAL;
	if (!users )
		return -ENOPROTOOPT;

	spin_lock_bh(&reg_lock);
	list_del_init(&up_ptr->uport_list);
	spin_unlock_bh(&reg_lock);
	return TIPC_OK;
}
Commit	Line	Data
b97bf3fd PL	1	/*
	2	* net/tipc/user_reg.c: TIPC user registry code
	3	*
593a5f22	4	* Copyright (c) 2000-2006, Ericsson AB
b97bf3fd	5	* Copyright (c) 2004-2005, Wind River Systems
b97bf3fd PL	6	* All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions are met:
9ea1fd3c PL	10	*
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. Neither the names of the copyright holders nor the names of its
	17	* contributors may be used to endorse or promote products derived from
	18	* this software without specific prior written permission.
	19	*
	20	* Alternatively, this software may be distributed under the terms of the
	21	* GNU General Public License ("GPL") version 2 as published by the Free
	22	* Software Foundation.
b97bf3fd PL	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	25	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	28	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	29	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	30	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	31	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	32	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	33	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	34	* POSSIBILITY OF SUCH DAMAGE.
	35	*/
	36
	37	#include "core.h"
	38	#include "user_reg.h"
	39
	40	/*
	41	* TIPC user registry keeps track of users of the tipc_port interface.
	42	*
	43	* The registry utilizes an array of "TIPC user" entries;
	44	* a user's ID is the index of their associated array entry.
	45	* Array entry 0 is not used, so userid 0 is not valid;
	46	* TIPC sometimes uses this value to denote an anonymous user.
	47	* The list of free entries is initially chained from last entry to entry 1.
	48	*/
	49
	50	/**
	51	* struct tipc_user - registered TIPC user info
	52	* @next: index of next free registry entry (or -1 for an allocated entry)
	53	* @callback: ptr to routine to call when TIPC mode changes (NULL if none)
	54	* @usr_handle: user-defined value passed to callback routine
	55	* @ports: list of user ports owned by the user
	56	*/
	57
	58	struct tipc_user {
	59	int next;
	60	tipc_mode_event callback;
	61	void *usr_handle;
	62	struct list_head ports;
	63	};
	64
	65	#define MAX_USERID 64
	66	#define USER_LIST_SIZE ((MAX_USERID + 1) * sizeof(struct tipc_user))
	67
1fc54d8f	68	static struct tipc_user *users = NULL;
b97bf3fd	69	static u32 next_free_user = MAX_USERID + 1;
34af946a	70	static DEFINE_SPINLOCK(reg_lock);
b97bf3fd PL	71
	72	/**
	73	* reg_init - create TIPC user registry (but don't activate it)
	74	*
	75	* If registry has been pre-initialized it is left "as is".
	76	* NOTE: This routine may be called when TIPC is inactive.
	77	*/
	78
	79	static int reg_init(void)
	80	{
	81	u32 i;
	82
	83	spin_lock_bh(&reg_lock);
	84	if (!users) {
	85	users = (struct tipc_user *)kmalloc(USER_LIST_SIZE, GFP_ATOMIC);
	86	if (users) {
	87	memset(users, 0, USER_LIST_SIZE);
	88	for (i = 1; i <= MAX_USERID; i++) {
	89	users[i].next = i - 1;
	90	}
	91	next_free_user = MAX_USERID;
	92	}
	93	}
	94	spin_unlock_bh(&reg_lock);
	95	return users ? TIPC_OK : -ENOMEM;
	96	}
	97
	98	/**
	99	* reg_callback - inform TIPC user about current operating mode
	100	*/
	101
	102	static void reg_callback(struct tipc_user *user_ptr)
	103	{
	104	tipc_mode_event cb;
	105	void *arg;
	106
	107	spin_lock_bh(&reg_lock);
	108	cb = user_ptr->callback;
	109	arg = user_ptr->usr_handle;
	110	spin_unlock_bh(&reg_lock);
	111
	112	if (cb)
	113	cb(arg, tipc_mode, tipc_own_addr);
	114	}
	115
	116	/**
4323add6	117	* tipc_reg_start - activate TIPC user registry
b97bf3fd PL	118	*/
b97bf3fd PL	119
4323add6	120	int tipc_reg_start(void)
b97bf3fd PL	121	{
	122	u32 u;
	123	int res;
	124
	125	if ((res = reg_init()))
	126	return res;
	127
	128	for (u = 1; u <= MAX_USERID; u++) {
	129	if (users[u].callback)
4323add6 PL	130	tipc_k_signal((Handler)reg_callback,
4323add6 PL	131	(unsigned long)&users[u]);
b97bf3fd PL	132	}
	133	return TIPC_OK;
	134	}
	135
	136	/**
4323add6	137	* tipc_reg_stop - shut down & delete TIPC user registry
b97bf3fd PL	138	*/
b97bf3fd PL	139
4323add6	140	void tipc_reg_stop(void)
b97bf3fd PL	141	{
	142	int id;
	143
	144	if (!users)
	145	return;
	146
	147	for (id = 1; id <= MAX_USERID; id++) {
	148	if (users[id].callback)
	149	reg_callback(&users[id]);
	150	}
	151	kfree(users);
1fc54d8f	152	users = NULL;
b97bf3fd PL	153	}
	154
	155	/**
	156	* tipc_attach - register a TIPC user
	157	*
	158	* NOTE: This routine may be called when TIPC is inactive.
	159	*/
	160
	161	int tipc_attach(u32 userid, tipc_mode_event cb, void usr_handle)
	162	{
	163	struct tipc_user *user_ptr;
	164
	165	if ((tipc_mode == TIPC_NOT_RUNNING) && !cb)
	166	return -ENOPROTOOPT;
	167	if (!users)
	168	reg_init();
	169
	170	spin_lock_bh(&reg_lock);
	171	if (!next_free_user) {
	172	spin_unlock_bh(&reg_lock);
	173	return -EBUSY;
	174	}
	175	user_ptr = &users[next_free_user];
	176	*userid = next_free_user;
	177	next_free_user = user_ptr->next;
	178	user_ptr->next = -1;
	179	spin_unlock_bh(&reg_lock);
	180
	181	user_ptr->callback = cb;
	182	user_ptr->usr_handle = usr_handle;
	183	INIT_LIST_HEAD(&user_ptr->ports);
	184	atomic_inc(&tipc_user_count);
	185
	186	if (cb && (tipc_mode != TIPC_NOT_RUNNING))
4323add6	187	tipc_k_signal((Handler)reg_callback, (unsigned long)user_ptr);
b97bf3fd PL	188	return TIPC_OK;
	189	}
	190
	191	/**
	192	* tipc_detach - deregister a TIPC user
	193	*/
	194
	195	void tipc_detach(u32 userid)
	196	{
	197	struct tipc_user *user_ptr;
	198	struct list_head ports_temp;
	199	struct user_port up_ptr, temp_up_ptr;
	200
	201	if ((userid == 0) \|\| (userid > MAX_USERID))
	202	return;
	203
	204	spin_lock_bh(&reg_lock);
	205	if ((!users) \|\| (users[userid].next >= 0)) {
	206	spin_unlock_bh(&reg_lock);
	207	return;
	208	}
	209
	210	user_ptr = &users[userid];
	211	user_ptr->callback = NULL;
	212	INIT_LIST_HEAD(&ports_temp);
	213	list_splice(&user_ptr->ports, &ports_temp);
	214	user_ptr->next = next_free_user;
	215	next_free_user = userid;
	216	spin_unlock_bh(&reg_lock);
	217
	218	atomic_dec(&tipc_user_count);
	219
	220	list_for_each_entry_safe(up_ptr, temp_up_ptr, &ports_temp, uport_list) {
	221	tipc_deleteport(up_ptr->ref);
	222	}
	223	}
	224
	225	/**
4323add6	226	* tipc_reg_add_port - register a user's driver port
b97bf3fd PL	227	*/
b97bf3fd PL	228
4323add6	229	int tipc_reg_add_port(struct user_port *up_ptr)
b97bf3fd PL	230	{
	231	struct tipc_user *user_ptr;
	232
	233	if (up_ptr->user_ref == 0)
	234	return TIPC_OK;
	235	if (up_ptr->user_ref > MAX_USERID)
	236	return -EINVAL;
	237	if ((tipc_mode == TIPC_NOT_RUNNING) \|\| !users )
	238	return -ENOPROTOOPT;
	239
	240	spin_lock_bh(&reg_lock);
	241	user_ptr = &users[up_ptr->user_ref];
	242	list_add(&up_ptr->uport_list, &user_ptr->ports);
	243	spin_unlock_bh(&reg_lock);
	244	return TIPC_OK;
	245	}
	246
	247	/**
4323add6	248	* tipc_reg_remove_port - deregister a user's driver port
b97bf3fd PL	249	*/
b97bf3fd PL	250
4323add6	251	int tipc_reg_remove_port(struct user_port *up_ptr)
b97bf3fd PL	252	{
	253	if (up_ptr->user_ref == 0)
	254	return TIPC_OK;
	255	if (up_ptr->user_ref > MAX_USERID)
	256	return -EINVAL;
	257	if (!users )
	258	return -ENOPROTOOPT;
	259
	260	spin_lock_bh(&reg_lock);
	261	list_del_init(&up_ptr->uport_list);
	262	spin_unlock_bh(&reg_lock);
	263	return TIPC_OK;
	264	}
	265