2 * net/tipc/user_reg.c: TIPC user registry code
4 * Copyright (c) 2003-2005, Ericsson Research Canada
5 * Copyright (c) 2004-2005, Wind River Systems
6 * Copyright (c) 2005-2006, Ericsson AB
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42 * TIPC user registry keeps track of users of the tipc_port interface.
44 * The registry utilizes an array of "TIPC user" entries;
45 * a user's ID is the index of their associated array entry.
46 * Array entry 0 is not used, so userid 0 is not valid;
47 * TIPC sometimes uses this value to denote an anonymous user.
48 * The list of free entries is initially chained from last entry to entry 1.
52 * struct tipc_user - registered TIPC user info
53 * @next: index of next free registry entry (or -1 for an allocated entry)
54 * @callback: ptr to routine to call when TIPC mode changes (NULL if none)
55 * @usr_handle: user-defined value passed to callback routine
56 * @ports: list of user ports owned by the user
61 tipc_mode_event callback;
63 struct list_head ports;
67 #define USER_LIST_SIZE ((MAX_USERID + 1) * sizeof(struct tipc_user))
69 static struct tipc_user *users = 0;
70 static u32 next_free_user = MAX_USERID + 1;
71 static spinlock_t reg_lock = SPIN_LOCK_UNLOCKED;
74 * reg_init - create TIPC user registry (but don't activate it)
76 * If registry has been pre-initialized it is left "as is".
77 * NOTE: This routine may be called when TIPC is inactive.
80 static int reg_init(void)
84 spin_lock_bh(®_lock);
86 users = (struct tipc_user *)kmalloc(USER_LIST_SIZE, GFP_ATOMIC);
88 memset(users, 0, USER_LIST_SIZE);
89 for (i = 1; i <= MAX_USERID; i++) {
90 users[i].next = i - 1;
92 next_free_user = MAX_USERID;
95 spin_unlock_bh(®_lock);
96 return users ? TIPC_OK : -ENOMEM;
100 * reg_callback - inform TIPC user about current operating mode
103 static void reg_callback(struct tipc_user *user_ptr)
108 spin_lock_bh(®_lock);
109 cb = user_ptr->callback;
110 arg = user_ptr->usr_handle;
111 spin_unlock_bh(®_lock);
114 cb(arg, tipc_mode, tipc_own_addr);
118 * reg_start - activate TIPC user registry
126 if ((res = reg_init()))
129 for (u = 1; u <= MAX_USERID; u++) {
130 if (users[u].callback)
131 k_signal((Handler)reg_callback,
132 (unsigned long)&users[u]);
138 * reg_stop - shut down & delete TIPC user registry
148 for (id = 1; id <= MAX_USERID; id++) {
149 if (users[id].callback)
150 reg_callback(&users[id]);
157 * tipc_attach - register a TIPC user
159 * NOTE: This routine may be called when TIPC is inactive.
162 int tipc_attach(u32 *userid, tipc_mode_event cb, void *usr_handle)
164 struct tipc_user *user_ptr;
166 if ((tipc_mode == TIPC_NOT_RUNNING) && !cb)
171 spin_lock_bh(®_lock);
172 if (!next_free_user) {
173 spin_unlock_bh(®_lock);
176 user_ptr = &users[next_free_user];
177 *userid = next_free_user;
178 next_free_user = user_ptr->next;
180 spin_unlock_bh(®_lock);
182 user_ptr->callback = cb;
183 user_ptr->usr_handle = usr_handle;
184 INIT_LIST_HEAD(&user_ptr->ports);
185 atomic_inc(&tipc_user_count);
187 if (cb && (tipc_mode != TIPC_NOT_RUNNING))
188 k_signal((Handler)reg_callback, (unsigned long)user_ptr);
193 * tipc_detach - deregister a TIPC user
196 void tipc_detach(u32 userid)
198 struct tipc_user *user_ptr;
199 struct list_head ports_temp;
200 struct user_port *up_ptr, *temp_up_ptr;
202 if ((userid == 0) || (userid > MAX_USERID))
205 spin_lock_bh(®_lock);
206 if ((!users) || (users[userid].next >= 0)) {
207 spin_unlock_bh(®_lock);
211 user_ptr = &users[userid];
212 user_ptr->callback = NULL;
213 INIT_LIST_HEAD(&ports_temp);
214 list_splice(&user_ptr->ports, &ports_temp);
215 user_ptr->next = next_free_user;
216 next_free_user = userid;
217 spin_unlock_bh(®_lock);
219 atomic_dec(&tipc_user_count);
221 list_for_each_entry_safe(up_ptr, temp_up_ptr, &ports_temp, uport_list) {
222 tipc_deleteport(up_ptr->ref);
227 * reg_add_port - register a user's driver port
230 int reg_add_port(struct user_port *up_ptr)
232 struct tipc_user *user_ptr;
234 if (up_ptr->user_ref == 0)
236 if (up_ptr->user_ref > MAX_USERID)
238 if ((tipc_mode == TIPC_NOT_RUNNING) || !users )
241 spin_lock_bh(®_lock);
242 user_ptr = &users[up_ptr->user_ref];
243 list_add(&up_ptr->uport_list, &user_ptr->ports);
244 spin_unlock_bh(®_lock);
249 * reg_remove_port - deregister a user's driver port
252 int reg_remove_port(struct user_port *up_ptr)
254 if (up_ptr->user_ref == 0)
256 if (up_ptr->user_ref > MAX_USERID)
261 spin_lock_bh(®_lock);
262 list_del_init(&up_ptr->uport_list);
263 spin_unlock_bh(®_lock);