Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 | /*
* 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;
}
|