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Diffstat (limited to 'net/tipc/user_reg.c')
| -rw-r--r-- | net/tipc/user_reg.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/net/tipc/user_reg.c b/net/tipc/user_reg.c new file mode 100644 index 0000000..5069288 --- /dev/null +++ b/net/tipc/user_reg.c @@ -0,0 +1,264 @@ +/* + * 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(®_lock); + if (!users) { + users = kzalloc(USER_LIST_SIZE, GFP_ATOMIC); + if (users) { + for (i = 1; i <= MAX_USERID; i++) { + users[i].next = i - 1; + } + next_free_user = MAX_USERID; + } + } + spin_unlock_bh(®_lock); + return users ? 0 : -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); +} + +/** + * 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 0; +} + +/** + * 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(®_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)) + tipc_k_signal((Handler)reg_callback, (unsigned long)user_ptr); + return 0; +} + +/** + * 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); + } +} + +/** + * 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 0; + 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 0; +} + +/** + * 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 0; + 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 0; +} + |
