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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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);