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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(®_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(®_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(®_lock); | |
108 | cb = user_ptr->callback; | |
109 | arg = user_ptr->usr_handle; | |
110 | spin_unlock_bh(®_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 | */ |
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, |
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 | */ |
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(®_lock); | |
171 | if (!next_free_user) { | |
172 | spin_unlock_bh(®_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(®_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(®_lock); | |
205 | if ((!users) || (users[userid].next >= 0)) { | |
206 | spin_unlock_bh(®_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(®_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 | */ |
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(®_lock); | |
241 | user_ptr = &users[up_ptr->user_ref]; | |
242 | list_add(&up_ptr->uport_list, &user_ptr->ports); | |
243 | spin_unlock_bh(®_lock); | |
244 | return TIPC_OK; | |
245 | } | |
246 | ||
247 | /** | |
4323add6 | 248 | * tipc_reg_remove_port - deregister a user's driver port |
b97bf3fd PL |
249 | */ |
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(®_lock); | |
261 | list_del_init(&up_ptr->uport_list); | |
262 | spin_unlock_bh(®_lock); | |
263 | return TIPC_OK; | |
264 | } | |
265 |