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2 * net/tipc/user_reg.c: TIPC user registry code
4 * Copyright (c) 2000-2006, Ericsson AB
5 * Copyright (c) 2004-2005, Wind River Systems
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9 * modification, are permitted provided that the following conditions are met:
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.
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.
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
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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.
41 * TIPC user registry keeps track of users of the tipc_port interface.
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.
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
60 tipc_mode_event callback
;
62 struct list_head ports
;
66 #define USER_LIST_SIZE ((MAX_USERID + 1) * sizeof(struct tipc_user))
68 static struct tipc_user
*users
= NULL
;
69 static u32 next_free_user
= MAX_USERID
+ 1;
70 static DEFINE_SPINLOCK(reg_lock
);
73 * reg_init - create TIPC user registry (but don't activate it)
75 * If registry has been pre-initialized it is left "as is".
76 * NOTE: This routine may be called when TIPC is inactive.
79 static int reg_init(void)
83 spin_lock_bh(®_lock
);
85 users
= kzalloc(USER_LIST_SIZE
, GFP_ATOMIC
);
87 for (i
= 1; i
<= MAX_USERID
; i
++) {
88 users
[i
].next
= i
- 1;
90 next_free_user
= MAX_USERID
;
93 spin_unlock_bh(®_lock
);
94 return users
? 0 : -ENOMEM
;
98 * reg_callback - inform TIPC user about current operating mode
101 static void reg_callback(struct tipc_user
*user_ptr
)
106 spin_lock_bh(®_lock
);
107 cb
= user_ptr
->callback
;
108 arg
= user_ptr
->usr_handle
;
109 spin_unlock_bh(®_lock
);
112 cb(arg
, tipc_mode
, tipc_own_addr
);
116 * tipc_reg_start - activate TIPC user registry
119 int tipc_reg_start(void)
124 if ((res
= reg_init()))
127 for (u
= 1; u
<= MAX_USERID
; u
++) {
128 if (users
[u
].callback
)
129 tipc_k_signal((Handler
)reg_callback
,
130 (unsigned long)&users
[u
]);
136 * tipc_reg_stop - shut down & delete TIPC user registry
139 void tipc_reg_stop(void)
146 for (id
= 1; id
<= MAX_USERID
; id
++) {
147 if (users
[id
].callback
)
148 reg_callback(&users
[id
]);
155 * tipc_attach - register a TIPC user
157 * NOTE: This routine may be called when TIPC is inactive.
160 int tipc_attach(u32
*userid
, tipc_mode_event cb
, void *usr_handle
)
162 struct tipc_user
*user_ptr
;
164 if ((tipc_mode
== TIPC_NOT_RUNNING
) && !cb
)
169 spin_lock_bh(®_lock
);
170 if (!next_free_user
) {
171 spin_unlock_bh(®_lock
);
174 user_ptr
= &users
[next_free_user
];
175 *userid
= next_free_user
;
176 next_free_user
= user_ptr
->next
;
178 spin_unlock_bh(®_lock
);
180 user_ptr
->callback
= cb
;
181 user_ptr
->usr_handle
= usr_handle
;
182 INIT_LIST_HEAD(&user_ptr
->ports
);
183 atomic_inc(&tipc_user_count
);
185 if (cb
&& (tipc_mode
!= TIPC_NOT_RUNNING
))
186 tipc_k_signal((Handler
)reg_callback
, (unsigned long)user_ptr
);
191 * tipc_detach - deregister a TIPC user
194 void tipc_detach(u32 userid
)
196 struct tipc_user
*user_ptr
;
197 struct list_head ports_temp
;
198 struct user_port
*up_ptr
, *temp_up_ptr
;
200 if ((userid
== 0) || (userid
> MAX_USERID
))
203 spin_lock_bh(®_lock
);
204 if ((!users
) || (users
[userid
].next
>= 0)) {
205 spin_unlock_bh(®_lock
);
209 user_ptr
= &users
[userid
];
210 user_ptr
->callback
= NULL
;
211 INIT_LIST_HEAD(&ports_temp
);
212 list_splice(&user_ptr
->ports
, &ports_temp
);
213 user_ptr
->next
= next_free_user
;
214 next_free_user
= userid
;
215 spin_unlock_bh(®_lock
);
217 atomic_dec(&tipc_user_count
);
219 list_for_each_entry_safe(up_ptr
, temp_up_ptr
, &ports_temp
, uport_list
) {
220 tipc_deleteport(up_ptr
->ref
);
225 * tipc_reg_add_port - register a user's driver port
228 int tipc_reg_add_port(struct user_port
*up_ptr
)
230 struct tipc_user
*user_ptr
;
232 if (up_ptr
->user_ref
== 0)
234 if (up_ptr
->user_ref
> MAX_USERID
)
236 if ((tipc_mode
== TIPC_NOT_RUNNING
) || !users
)
239 spin_lock_bh(®_lock
);
240 user_ptr
= &users
[up_ptr
->user_ref
];
241 list_add(&up_ptr
->uport_list
, &user_ptr
->ports
);
242 spin_unlock_bh(®_lock
);
247 * tipc_reg_remove_port - deregister a user's driver port
250 int tipc_reg_remove_port(struct user_port
*up_ptr
)
252 if (up_ptr
->user_ref
== 0)
254 if (up_ptr
->user_ref
> MAX_USERID
)
259 spin_lock_bh(®_lock
);
260 list_del_init(&up_ptr
->uport_list
);
261 spin_unlock_bh(®_lock
);