/*
* 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 = 0;
static u32 next_free_user = MAX_USERID + 1;
static spinlock_t reg_lock = SPIN_LOCK_UNLOCKED;
/**
* 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(®_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(®_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(®_lock);
cb = user_ptr->callback;
arg = user_ptr->usr_handle;
spin_unlock_bh(®_lock);
if (cb)
cb(arg, tipc_mode, tipc_own_addr);
}
/**
* reg_start - activate TIPC user registry
*/
int reg_start(void)
{
u32 u;
int res;
if ((res = reg_init()))
return res;
for (u = 1; u <= MAX_USERID; u++) {
if (users[u].callback)
k_signal((Handler)reg_callback,
(unsigned long)&users[u]);
}
return TIPC_OK;
}
/**
* reg_stop - shut down & delete TIPC user registry
*/
void 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 = 0;
}
/**
* 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(®_lock);
if (!next_free_user) {
spin_unlock_bh(®_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(®_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))
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(®_lock);
if ((!users) || (users[userid].next >= 0)) {
spin_unlock_bh(®_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(®_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);
}
}
/**
* reg_add_port - register a user's driver port
*/
int 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(®_lock);
user_ptr = &users[up_ptr->user_ref];
list_add(&up_ptr->uport_list, &user_ptr->ports);
spin_unlock_bh(®_lock);
return TIPC_OK;
}
/**
* reg_remove_port - deregister a user's driver port
*/
int 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(®_lock);
list_del_init(&up_ptr->uport_list);
spin_unlock_bh(®_lock);
return TIPC_OK;
}
