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1 | /* |
2 | * net/tipc/user_reg.c: TIPC user registry code | |
3 | * | |
4 | * Copyright (c) 2003-2005, Ericsson Research Canada | |
5 | * Copyright (c) 2004-2005, Wind River Systems | |
6 | * Copyright (c) 2005-2006, Ericsson AB | |
7 | * All rights reserved. | |
8 | * | |
9 | * Redistribution and use in source and binary forms, with or without | |
10 | * modification, are permitted provided that the following conditions are met: | |
11 | * | |
12 | * Redistributions of source code must retain the above copyright notice, this | |
13 | * list of conditions and the following disclaimer. | |
14 | * Redistributions in binary form must reproduce the above copyright notice, | |
15 | * this list of conditions and the following disclaimer in the documentation | |
16 | * and/or other materials provided with the distribution. | |
17 | * Neither the names of the copyright holders nor the names of its | |
18 | * contributors may be used to endorse or promote products derived from this | |
19 | * software without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
22 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | |
25 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
31 | * POSSIBILITY OF SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | #include "core.h" | |
35 | #include "user_reg.h" | |
36 | ||
37 | /* | |
38 | * TIPC user registry keeps track of users of the tipc_port interface. | |
39 | * | |
40 | * The registry utilizes an array of "TIPC user" entries; | |
41 | * a user's ID is the index of their associated array entry. | |
42 | * Array entry 0 is not used, so userid 0 is not valid; | |
43 | * TIPC sometimes uses this value to denote an anonymous user. | |
44 | * The list of free entries is initially chained from last entry to entry 1. | |
45 | */ | |
46 | ||
47 | /** | |
48 | * struct tipc_user - registered TIPC user info | |
49 | * @next: index of next free registry entry (or -1 for an allocated entry) | |
50 | * @callback: ptr to routine to call when TIPC mode changes (NULL if none) | |
51 | * @usr_handle: user-defined value passed to callback routine | |
52 | * @ports: list of user ports owned by the user | |
53 | */ | |
54 | ||
55 | struct tipc_user { | |
56 | int next; | |
57 | tipc_mode_event callback; | |
58 | void *usr_handle; | |
59 | struct list_head ports; | |
60 | }; | |
61 | ||
62 | #define MAX_USERID 64 | |
63 | #define USER_LIST_SIZE ((MAX_USERID + 1) * sizeof(struct tipc_user)) | |
64 | ||
65 | static struct tipc_user *users = 0; | |
66 | static u32 next_free_user = MAX_USERID + 1; | |
67 | static spinlock_t reg_lock = SPIN_LOCK_UNLOCKED; | |
68 | ||
69 | /** | |
70 | * reg_init - create TIPC user registry (but don't activate it) | |
71 | * | |
72 | * If registry has been pre-initialized it is left "as is". | |
73 | * NOTE: This routine may be called when TIPC is inactive. | |
74 | */ | |
75 | ||
76 | static int reg_init(void) | |
77 | { | |
78 | u32 i; | |
79 | ||
80 | spin_lock_bh(®_lock); | |
81 | if (!users) { | |
82 | users = (struct tipc_user *)kmalloc(USER_LIST_SIZE, GFP_ATOMIC); | |
83 | if (users) { | |
84 | memset(users, 0, USER_LIST_SIZE); | |
85 | for (i = 1; i <= MAX_USERID; i++) { | |
86 | users[i].next = i - 1; | |
87 | } | |
88 | next_free_user = MAX_USERID; | |
89 | } | |
90 | } | |
91 | spin_unlock_bh(®_lock); | |
92 | return users ? TIPC_OK : -ENOMEM; | |
93 | } | |
94 | ||
95 | /** | |
96 | * reg_callback - inform TIPC user about current operating mode | |
97 | */ | |
98 | ||
99 | static void reg_callback(struct tipc_user *user_ptr) | |
100 | { | |
101 | tipc_mode_event cb; | |
102 | void *arg; | |
103 | ||
104 | spin_lock_bh(®_lock); | |
105 | cb = user_ptr->callback; | |
106 | arg = user_ptr->usr_handle; | |
107 | spin_unlock_bh(®_lock); | |
108 | ||
109 | if (cb) | |
110 | cb(arg, tipc_mode, tipc_own_addr); | |
111 | } | |
112 | ||
113 | /** | |
114 | * reg_start - activate TIPC user registry | |
115 | */ | |
116 | ||
117 | int reg_start(void) | |
118 | { | |
119 | u32 u; | |
120 | int res; | |
121 | ||
122 | if ((res = reg_init())) | |
123 | return res; | |
124 | ||
125 | for (u = 1; u <= MAX_USERID; u++) { | |
126 | if (users[u].callback) | |
127 | k_signal((Handler)reg_callback, | |
128 | (unsigned long)&users[u]); | |
129 | } | |
130 | return TIPC_OK; | |
131 | } | |
132 | ||
133 | /** | |
134 | * reg_stop - shut down & delete TIPC user registry | |
135 | */ | |
136 | ||
137 | void reg_stop(void) | |
138 | { | |
139 | int id; | |
140 | ||
141 | if (!users) | |
142 | return; | |
143 | ||
144 | for (id = 1; id <= MAX_USERID; id++) { | |
145 | if (users[id].callback) | |
146 | reg_callback(&users[id]); | |
147 | } | |
148 | kfree(users); | |
149 | users = 0; | |
150 | } | |
151 | ||
152 | /** | |
153 | * tipc_attach - register a TIPC user | |
154 | * | |
155 | * NOTE: This routine may be called when TIPC is inactive. | |
156 | */ | |
157 | ||
158 | int tipc_attach(u32 *userid, tipc_mode_event cb, void *usr_handle) | |
159 | { | |
160 | struct tipc_user *user_ptr; | |
161 | ||
162 | if ((tipc_mode == TIPC_NOT_RUNNING) && !cb) | |
163 | return -ENOPROTOOPT; | |
164 | if (!users) | |
165 | reg_init(); | |
166 | ||
167 | spin_lock_bh(®_lock); | |
168 | if (!next_free_user) { | |
169 | spin_unlock_bh(®_lock); | |
170 | return -EBUSY; | |
171 | } | |
172 | user_ptr = &users[next_free_user]; | |
173 | *userid = next_free_user; | |
174 | next_free_user = user_ptr->next; | |
175 | user_ptr->next = -1; | |
176 | spin_unlock_bh(®_lock); | |
177 | ||
178 | user_ptr->callback = cb; | |
179 | user_ptr->usr_handle = usr_handle; | |
180 | INIT_LIST_HEAD(&user_ptr->ports); | |
181 | atomic_inc(&tipc_user_count); | |
182 | ||
183 | if (cb && (tipc_mode != TIPC_NOT_RUNNING)) | |
184 | k_signal((Handler)reg_callback, (unsigned long)user_ptr); | |
185 | return TIPC_OK; | |
186 | } | |
187 | ||
188 | /** | |
189 | * tipc_detach - deregister a TIPC user | |
190 | */ | |
191 | ||
192 | void tipc_detach(u32 userid) | |
193 | { | |
194 | struct tipc_user *user_ptr; | |
195 | struct list_head ports_temp; | |
196 | struct user_port *up_ptr, *temp_up_ptr; | |
197 | ||
198 | if ((userid == 0) || (userid > MAX_USERID)) | |
199 | return; | |
200 | ||
201 | spin_lock_bh(®_lock); | |
202 | if ((!users) || (users[userid].next >= 0)) { | |
203 | spin_unlock_bh(®_lock); | |
204 | return; | |
205 | } | |
206 | ||
207 | user_ptr = &users[userid]; | |
208 | user_ptr->callback = NULL; | |
209 | INIT_LIST_HEAD(&ports_temp); | |
210 | list_splice(&user_ptr->ports, &ports_temp); | |
211 | user_ptr->next = next_free_user; | |
212 | next_free_user = userid; | |
213 | spin_unlock_bh(®_lock); | |
214 | ||
215 | atomic_dec(&tipc_user_count); | |
216 | ||
217 | list_for_each_entry_safe(up_ptr, temp_up_ptr, &ports_temp, uport_list) { | |
218 | tipc_deleteport(up_ptr->ref); | |
219 | } | |
220 | } | |
221 | ||
222 | /** | |
223 | * reg_add_port - register a user's driver port | |
224 | */ | |
225 | ||
226 | int reg_add_port(struct user_port *up_ptr) | |
227 | { | |
228 | struct tipc_user *user_ptr; | |
229 | ||
230 | if (up_ptr->user_ref == 0) | |
231 | return TIPC_OK; | |
232 | if (up_ptr->user_ref > MAX_USERID) | |
233 | return -EINVAL; | |
234 | if ((tipc_mode == TIPC_NOT_RUNNING) || !users ) | |
235 | return -ENOPROTOOPT; | |
236 | ||
237 | spin_lock_bh(®_lock); | |
238 | user_ptr = &users[up_ptr->user_ref]; | |
239 | list_add(&up_ptr->uport_list, &user_ptr->ports); | |
240 | spin_unlock_bh(®_lock); | |
241 | return TIPC_OK; | |
242 | } | |
243 | ||
244 | /** | |
245 | * reg_remove_port - deregister a user's driver port | |
246 | */ | |
247 | ||
248 | int reg_remove_port(struct user_port *up_ptr) | |
249 | { | |
250 | if (up_ptr->user_ref == 0) | |
251 | return TIPC_OK; | |
252 | if (up_ptr->user_ref > MAX_USERID) | |
253 | return -EINVAL; | |
254 | if (!users ) | |
255 | return -ENOPROTOOPT; | |
256 | ||
257 | spin_lock_bh(®_lock); | |
258 | list_del_init(&up_ptr->uport_list); | |
259 | spin_unlock_bh(®_lock); | |
260 | return TIPC_OK; | |
261 | } | |
262 |