1 /*
2  * Linux WiMAX
3  * Initialization, addition and removal of wimax devices
4  *
5  *
6  * Copyright (C) 2005-2006 Intel Corporation <linux-wimax@intel.com>
7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License version
11  * 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21  * 02110-1301, USA.
22  *
23  *
24  * This implements:
25  *
26  *   - basic life cycle of 'struct wimax_dev' [wimax_dev_*()]; on
27  *     addition/registration initialize all subfields and allocate
28  *     generic netlink resources for user space communication. On
29  *     removal/unregistration, undo all that.
30  *
31  *   - device state machine [wimax_state_change()] and support to send
32  *     reports to user space when the state changes
33  *     [wimax_gnl_re_state_change*()].
34  *
35  * See include/net/wimax.h for rationales and design.
36  *
37  * ROADMAP
38  *
39  * [__]wimax_state_change()     Called by drivers to update device's state
40  *   wimax_gnl_re_state_change_alloc()
41  *   wimax_gnl_re_state_change_send()
42  *
43  * wimax_dev_init()	        Init a device
44  * wimax_dev_add()              Register
45  *   wimax_rfkill_add()
46  *   wimax_gnl_add()            Register all the generic netlink resources.
47  *   wimax_id_table_add()
48  * wimax_dev_rm()               Unregister
49  *   wimax_id_table_rm()
50  *   wimax_gnl_rm()
51  *   wimax_rfkill_rm()
52  */
53 #include <linux/device.h>
54 #include <linux/gfp.h>
55 #include <net/genetlink.h>
56 #include <linux/netdevice.h>
57 #include <linux/wimax.h>
58 #include "wimax-internal.h"
59 
60 
61 #define D_SUBMODULE stack
62 #include "debug-levels.h"
63 
64 static char wimax_debug_params[128];
65 module_param_string(debug, wimax_debug_params, sizeof(wimax_debug_params),
66 		    0644);
67 MODULE_PARM_DESC(debug,
68 		 "String of space-separated NAME:VALUE pairs, where NAMEs "
69 		 "are the different debug submodules and VALUE are the "
70 		 "initial debug value to set.");
71 
72 /*
73  * Authoritative source for the RE_STATE_CHANGE attribute policy
74  *
75  * We don't really use it here, but /me likes to keep the definition
76  * close to where the data is generated.
77  */
78 /*
79 static const struct nla_policy wimax_gnl_re_status_change[WIMAX_GNL_ATTR_MAX + 1] = {
80 	[WIMAX_GNL_STCH_STATE_OLD] = { .type = NLA_U8 },
81 	[WIMAX_GNL_STCH_STATE_NEW] = { .type = NLA_U8 },
82 };
83 */
84 
85 
86 /*
87  * Allocate a Report State Change message
88  *
89  * @header: save it, you need it for _send()
90  *
91  * Creates and fills a basic state change message; different code
92  * paths can then add more attributes to the message as needed.
93  *
94  * Use wimax_gnl_re_state_change_send() to send the returned skb.
95  *
96  * Returns: skb with the genl message if ok, IS_ERR() ptr on error
97  *     with an errno code.
98  */
99 static
wimax_gnl_re_state_change_alloc(struct wimax_dev * wimax_dev,enum wimax_st new_state,enum wimax_st old_state,void ** header)100 struct sk_buff *wimax_gnl_re_state_change_alloc(
101 	struct wimax_dev *wimax_dev,
102 	enum wimax_st new_state, enum wimax_st old_state,
103 	void **header)
104 {
105 	int result;
106 	struct device *dev = wimax_dev_to_dev(wimax_dev);
107 	void *data;
108 	struct sk_buff *report_skb;
109 
110 	d_fnstart(3, dev, "(wimax_dev %p new_state %u old_state %u)\n",
111 		  wimax_dev, new_state, old_state);
112 	result = -ENOMEM;
113 	report_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
114 	if (report_skb == NULL) {
115 		dev_err(dev, "RE_STCH: can't create message\n");
116 		goto error_new;
117 	}
118 	data = genlmsg_put(report_skb, 0, wimax_gnl_mcg.id, &wimax_gnl_family,
119 			   0, WIMAX_GNL_RE_STATE_CHANGE);
120 	if (data == NULL) {
121 		dev_err(dev, "RE_STCH: can't put data into message\n");
122 		goto error_put;
123 	}
124 	*header = data;
125 
126 	result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_OLD, old_state);
127 	if (result < 0) {
128 		dev_err(dev, "RE_STCH: Error adding OLD attr: %d\n", result);
129 		goto error_put;
130 	}
131 	result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_NEW, new_state);
132 	if (result < 0) {
133 		dev_err(dev, "RE_STCH: Error adding NEW attr: %d\n", result);
134 		goto error_put;
135 	}
136 	result = nla_put_u32(report_skb, WIMAX_GNL_STCH_IFIDX,
137 			     wimax_dev->net_dev->ifindex);
138 	if (result < 0) {
139 		dev_err(dev, "RE_STCH: Error adding IFINDEX attribute\n");
140 		goto error_put;
141 	}
142 	d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %p\n",
143 		wimax_dev, new_state, old_state, report_skb);
144 	return report_skb;
145 
146 error_put:
147 	nlmsg_free(report_skb);
148 error_new:
149 	d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %d\n",
150 		wimax_dev, new_state, old_state, result);
151 	return ERR_PTR(result);
152 }
153 
154 
155 /*
156  * Send a Report State Change message (as created with _alloc).
157  *
158  * @report_skb: as returned by wimax_gnl_re_state_change_alloc()
159  * @header: as returned by wimax_gnl_re_state_change_alloc()
160  *
161  * Returns: 0 if ok, < 0 errno code on error.
162  *
163  * If the message is  NULL, pretend it didn't happen.
164  */
165 static
wimax_gnl_re_state_change_send(struct wimax_dev * wimax_dev,struct sk_buff * report_skb,void * header)166 int wimax_gnl_re_state_change_send(
167 	struct wimax_dev *wimax_dev, struct sk_buff *report_skb,
168 	void *header)
169 {
170 	int result = 0;
171 	struct device *dev = wimax_dev_to_dev(wimax_dev);
172 	d_fnstart(3, dev, "(wimax_dev %p report_skb %p)\n",
173 		  wimax_dev, report_skb);
174 	if (report_skb == NULL) {
175 		result = -ENOMEM;
176 		goto out;
177 	}
178 	genlmsg_end(report_skb, header);
179 	genlmsg_multicast(report_skb, 0, wimax_gnl_mcg.id, GFP_KERNEL);
180 out:
181 	d_fnend(3, dev, "(wimax_dev %p report_skb %p) = %d\n",
182 		wimax_dev, report_skb, result);
183 	return result;
184 }
185 
186 
187 static
__check_new_state(enum wimax_st old_state,enum wimax_st new_state,unsigned allowed_states_bm)188 void __check_new_state(enum wimax_st old_state, enum wimax_st new_state,
189 		       unsigned allowed_states_bm)
190 {
191 	if (WARN_ON(((1 << new_state) & allowed_states_bm) == 0)) {
192 		printk(KERN_ERR "SW BUG! Forbidden state change %u -> %u\n",
193 			old_state, new_state);
194 	}
195 }
196 
197 
198 /*
199  * Set the current state of a WiMAX device [unlocking version of
200  * wimax_state_change().
201  */
__wimax_state_change(struct wimax_dev * wimax_dev,enum wimax_st new_state)202 void __wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
203 {
204 	struct device *dev = wimax_dev_to_dev(wimax_dev);
205 	enum wimax_st old_state = wimax_dev->state;
206 	struct sk_buff *stch_skb;
207 	void *header;
208 
209 	d_fnstart(3, dev, "(wimax_dev %p new_state %u [old %u])\n",
210 		  wimax_dev, new_state, old_state);
211 
212 	if (WARN_ON(new_state >= __WIMAX_ST_INVALID)) {
213 		dev_err(dev, "SW BUG: requesting invalid state %u\n",
214 			new_state);
215 		goto out;
216 	}
217 	if (old_state == new_state)
218 		goto out;
219 	header = NULL;	/* gcc complains? can't grok why */
220 	stch_skb = wimax_gnl_re_state_change_alloc(
221 		wimax_dev, new_state, old_state, &header);
222 
223 	/* Verify the state transition and do exit-from-state actions */
224 	switch (old_state) {
225 	case __WIMAX_ST_NULL:
226 		__check_new_state(old_state, new_state,
227 				  1 << WIMAX_ST_DOWN);
228 		break;
229 	case WIMAX_ST_DOWN:
230 		__check_new_state(old_state, new_state,
231 				  1 << __WIMAX_ST_QUIESCING
232 				  | 1 << WIMAX_ST_UNINITIALIZED
233 				  | 1 << WIMAX_ST_RADIO_OFF);
234 		break;
235 	case __WIMAX_ST_QUIESCING:
236 		__check_new_state(old_state, new_state, 1 << WIMAX_ST_DOWN);
237 		break;
238 	case WIMAX_ST_UNINITIALIZED:
239 		__check_new_state(old_state, new_state,
240 				  1 << __WIMAX_ST_QUIESCING
241 				  | 1 << WIMAX_ST_RADIO_OFF);
242 		break;
243 	case WIMAX_ST_RADIO_OFF:
244 		__check_new_state(old_state, new_state,
245 				  1 << __WIMAX_ST_QUIESCING
246 				  | 1 << WIMAX_ST_READY);
247 		break;
248 	case WIMAX_ST_READY:
249 		__check_new_state(old_state, new_state,
250 				  1 << __WIMAX_ST_QUIESCING
251 				  | 1 << WIMAX_ST_RADIO_OFF
252 				  | 1 << WIMAX_ST_SCANNING
253 				  | 1 << WIMAX_ST_CONNECTING
254 				  | 1 << WIMAX_ST_CONNECTED);
255 		break;
256 	case WIMAX_ST_SCANNING:
257 		__check_new_state(old_state, new_state,
258 				  1 << __WIMAX_ST_QUIESCING
259 				  | 1 << WIMAX_ST_RADIO_OFF
260 				  | 1 << WIMAX_ST_READY
261 				  | 1 << WIMAX_ST_CONNECTING
262 				  | 1 << WIMAX_ST_CONNECTED);
263 		break;
264 	case WIMAX_ST_CONNECTING:
265 		__check_new_state(old_state, new_state,
266 				  1 << __WIMAX_ST_QUIESCING
267 				  | 1 << WIMAX_ST_RADIO_OFF
268 				  | 1 << WIMAX_ST_READY
269 				  | 1 << WIMAX_ST_SCANNING
270 				  | 1 << WIMAX_ST_CONNECTED);
271 		break;
272 	case WIMAX_ST_CONNECTED:
273 		__check_new_state(old_state, new_state,
274 				  1 << __WIMAX_ST_QUIESCING
275 				  | 1 << WIMAX_ST_RADIO_OFF
276 				  | 1 << WIMAX_ST_READY);
277 		netif_tx_disable(wimax_dev->net_dev);
278 		netif_carrier_off(wimax_dev->net_dev);
279 		break;
280 	case __WIMAX_ST_INVALID:
281 	default:
282 		dev_err(dev, "SW BUG: wimax_dev %p is in unknown state %u\n",
283 			wimax_dev, wimax_dev->state);
284 		WARN_ON(1);
285 		goto out;
286 	}
287 
288 	/* Execute the actions of entry to the new state */
289 	switch (new_state) {
290 	case __WIMAX_ST_NULL:
291 		dev_err(dev, "SW BUG: wimax_dev %p entering NULL state "
292 			"from %u\n", wimax_dev, wimax_dev->state);
293 		WARN_ON(1);		/* Nobody can enter this state */
294 		break;
295 	case WIMAX_ST_DOWN:
296 		break;
297 	case __WIMAX_ST_QUIESCING:
298 		break;
299 	case WIMAX_ST_UNINITIALIZED:
300 		break;
301 	case WIMAX_ST_RADIO_OFF:
302 		break;
303 	case WIMAX_ST_READY:
304 		break;
305 	case WIMAX_ST_SCANNING:
306 		break;
307 	case WIMAX_ST_CONNECTING:
308 		break;
309 	case WIMAX_ST_CONNECTED:
310 		netif_carrier_on(wimax_dev->net_dev);
311 		netif_wake_queue(wimax_dev->net_dev);
312 		break;
313 	case __WIMAX_ST_INVALID:
314 	default:
315 		BUG();
316 	}
317 	__wimax_state_set(wimax_dev, new_state);
318 	if (!IS_ERR(stch_skb))
319 		wimax_gnl_re_state_change_send(wimax_dev, stch_skb, header);
320 out:
321 	d_fnend(3, dev, "(wimax_dev %p new_state %u [old %u]) = void\n",
322 		wimax_dev, new_state, old_state);
323 }
324 
325 
326 /**
327  * wimax_state_change - Set the current state of a WiMAX device
328  *
329  * @wimax_dev: WiMAX device descriptor (properly referenced)
330  * @new_state: New state to switch to
331  *
332  * This implements the state changes for the wimax devices. It will
333  *
334  * - verify that the state transition is legal (for now it'll just
335  *   print a warning if not) according to the table in
336  *   linux/wimax.h's documentation for 'enum wimax_st'.
337  *
338  * - perform the actions needed for leaving the current state and
339  *   whichever are needed for entering the new state.
340  *
341  * - issue a report to user space indicating the new state (and an
342  *   optional payload with information about the new state).
343  *
344  * NOTE: @wimax_dev must be locked
345  */
wimax_state_change(struct wimax_dev * wimax_dev,enum wimax_st new_state)346 void wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
347 {
348 	/*
349 	 * A driver cannot take the wimax_dev out of the
350 	 * __WIMAX_ST_NULL state unless by calling wimax_dev_add(). If
351 	 * the wimax_dev's state is still NULL, we ignore any request
352 	 * to change its state because it means it hasn't been yet
353 	 * registered.
354 	 *
355 	 * There is no need to complain about it, as routines that
356 	 * call this might be shared from different code paths that
357 	 * are called before or after wimax_dev_add() has done its
358 	 * job.
359 	 */
360 	mutex_lock(&wimax_dev->mutex);
361 	if (wimax_dev->state > __WIMAX_ST_NULL)
362 		__wimax_state_change(wimax_dev, new_state);
363 	mutex_unlock(&wimax_dev->mutex);
364 }
365 EXPORT_SYMBOL_GPL(wimax_state_change);
366 
367 
368 /**
369  * wimax_state_get() - Return the current state of a WiMAX device
370  *
371  * @wimax_dev: WiMAX device descriptor
372  *
373  * Returns: Current state of the device according to its driver.
374  */
wimax_state_get(struct wimax_dev * wimax_dev)375 enum wimax_st wimax_state_get(struct wimax_dev *wimax_dev)
376 {
377 	enum wimax_st state;
378 	mutex_lock(&wimax_dev->mutex);
379 	state = wimax_dev->state;
380 	mutex_unlock(&wimax_dev->mutex);
381 	return state;
382 }
383 EXPORT_SYMBOL_GPL(wimax_state_get);
384 
385 
386 /**
387  * wimax_dev_init - initialize a newly allocated instance
388  *
389  * @wimax_dev: WiMAX device descriptor to initialize.
390  *
391  * Initializes fields of a freshly allocated @wimax_dev instance. This
392  * function assumes that after allocation, the memory occupied by
393  * @wimax_dev was zeroed.
394  */
wimax_dev_init(struct wimax_dev * wimax_dev)395 void wimax_dev_init(struct wimax_dev *wimax_dev)
396 {
397 	INIT_LIST_HEAD(&wimax_dev->id_table_node);
398 	__wimax_state_set(wimax_dev, __WIMAX_ST_NULL);
399 	mutex_init(&wimax_dev->mutex);
400 	mutex_init(&wimax_dev->mutex_reset);
401 }
402 EXPORT_SYMBOL_GPL(wimax_dev_init);
403 
404 /*
405  * This extern is declared here because it's easier to keep track --
406  * both declarations are a list of the same
407  */
408 extern struct genl_ops
409 	wimax_gnl_msg_from_user,
410 	wimax_gnl_reset,
411 	wimax_gnl_rfkill,
412 	wimax_gnl_state_get;
413 
414 static
415 struct genl_ops *wimax_gnl_ops[] = {
416 	&wimax_gnl_msg_from_user,
417 	&wimax_gnl_reset,
418 	&wimax_gnl_rfkill,
419 	&wimax_gnl_state_get,
420 };
421 
422 
423 static
wimax_addr_scnprint(char * addr_str,size_t addr_str_size,unsigned char * addr,size_t addr_len)424 size_t wimax_addr_scnprint(char *addr_str, size_t addr_str_size,
425 			   unsigned char *addr, size_t addr_len)
426 {
427 	unsigned cnt, total;
428 	for (total = cnt = 0; cnt < addr_len; cnt++)
429 		total += scnprintf(addr_str + total, addr_str_size - total,
430 				   "%02x%c", addr[cnt],
431 				   cnt == addr_len - 1 ? '\0' : ':');
432 	return total;
433 }
434 
435 
436 /**
437  * wimax_dev_add - Register a new WiMAX device
438  *
439  * @wimax_dev: WiMAX device descriptor (as embedded in your @net_dev's
440  *     priv data). You must have called wimax_dev_init() on it before.
441  *
442  * @net_dev: net device the @wimax_dev is associated with. The
443  *     function expects SET_NETDEV_DEV() and register_netdev() were
444  *     already called on it.
445  *
446  * Registers the new WiMAX device, sets up the user-kernel control
447  * interface (generic netlink) and common WiMAX infrastructure.
448  *
449  * Note that the parts that will allow interaction with user space are
450  * setup at the very end, when the rest is in place, as once that
451  * happens, the driver might get user space control requests via
452  * netlink or from debugfs that might translate into calls into
453  * wimax_dev->op_*().
454  */
wimax_dev_add(struct wimax_dev * wimax_dev,struct net_device * net_dev)455 int wimax_dev_add(struct wimax_dev *wimax_dev, struct net_device *net_dev)
456 {
457 	int result;
458 	struct device *dev = net_dev->dev.parent;
459 	char addr_str[32];
460 
461 	d_fnstart(3, dev, "(wimax_dev %p net_dev %p)\n", wimax_dev, net_dev);
462 
463 	/* Do the RFKILL setup before locking, as RFKILL will call
464 	 * into our functions. */
465 	wimax_dev->net_dev = net_dev;
466 	result = wimax_rfkill_add(wimax_dev);
467 	if (result < 0)
468 		goto error_rfkill_add;
469 
470 	/* Set up user-space interaction */
471 	mutex_lock(&wimax_dev->mutex);
472 	wimax_id_table_add(wimax_dev);
473 	result = wimax_debugfs_add(wimax_dev);
474 	if (result < 0) {
475 		dev_err(dev, "cannot initialize debugfs: %d\n",
476 			result);
477 		goto error_debugfs_add;
478 	}
479 
480 	__wimax_state_set(wimax_dev, WIMAX_ST_DOWN);
481 	mutex_unlock(&wimax_dev->mutex);
482 
483 	wimax_addr_scnprint(addr_str, sizeof(addr_str),
484 			    net_dev->dev_addr, net_dev->addr_len);
485 	dev_err(dev, "WiMAX interface %s (%s) ready\n",
486 		net_dev->name, addr_str);
487 	d_fnend(3, dev, "(wimax_dev %p net_dev %p) = 0\n", wimax_dev, net_dev);
488 	return 0;
489 
490 error_debugfs_add:
491 	wimax_id_table_rm(wimax_dev);
492 	mutex_unlock(&wimax_dev->mutex);
493 	wimax_rfkill_rm(wimax_dev);
494 error_rfkill_add:
495 	d_fnend(3, dev, "(wimax_dev %p net_dev %p) = %d\n",
496 		wimax_dev, net_dev, result);
497 	return result;
498 }
499 EXPORT_SYMBOL_GPL(wimax_dev_add);
500 
501 
502 /**
503  * wimax_dev_rm - Unregister an existing WiMAX device
504  *
505  * @wimax_dev: WiMAX device descriptor
506  *
507  * Unregisters a WiMAX device previously registered for use with
508  * wimax_add_rm().
509  *
510  * IMPORTANT! Must call before calling unregister_netdev().
511  *
512  * After this function returns, you will not get any more user space
513  * control requests (via netlink or debugfs) and thus to wimax_dev->ops.
514  *
515  * Reentrancy control is ensured by setting the state to
516  * %__WIMAX_ST_QUIESCING. rfkill operations coming through
517  * wimax_*rfkill*() will be stopped by the quiescing state; ops coming
518  * from the rfkill subsystem will be stopped by the support being
519  * removed by wimax_rfkill_rm().
520  */
wimax_dev_rm(struct wimax_dev * wimax_dev)521 void wimax_dev_rm(struct wimax_dev *wimax_dev)
522 {
523 	d_fnstart(3, NULL, "(wimax_dev %p)\n", wimax_dev);
524 
525 	mutex_lock(&wimax_dev->mutex);
526 	__wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
527 	wimax_debugfs_rm(wimax_dev);
528 	wimax_id_table_rm(wimax_dev);
529 	__wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
530 	mutex_unlock(&wimax_dev->mutex);
531 	wimax_rfkill_rm(wimax_dev);
532 	d_fnend(3, NULL, "(wimax_dev %p) = void\n", wimax_dev);
533 }
534 EXPORT_SYMBOL_GPL(wimax_dev_rm);
535 
536 
537 /* Debug framework control of debug levels */
538 struct d_level D_LEVEL[] = {
539 	D_SUBMODULE_DEFINE(debugfs),
540 	D_SUBMODULE_DEFINE(id_table),
541 	D_SUBMODULE_DEFINE(op_msg),
542 	D_SUBMODULE_DEFINE(op_reset),
543 	D_SUBMODULE_DEFINE(op_rfkill),
544 	D_SUBMODULE_DEFINE(op_state_get),
545 	D_SUBMODULE_DEFINE(stack),
546 };
547 size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
548 
549 
550 struct genl_family wimax_gnl_family = {
551 	.id = GENL_ID_GENERATE,
552 	.name = "WiMAX",
553 	.version = WIMAX_GNL_VERSION,
554 	.hdrsize = 0,
555 	.maxattr = WIMAX_GNL_ATTR_MAX,
556 };
557 
558 struct genl_multicast_group wimax_gnl_mcg = {
559 	.name = "msg",
560 };
561 
562 
563 
564 /* Shutdown the wimax stack */
565 static
wimax_subsys_init(void)566 int __init wimax_subsys_init(void)
567 {
568 	int result, cnt;
569 
570 	d_fnstart(4, NULL, "()\n");
571 	d_parse_params(D_LEVEL, D_LEVEL_SIZE, wimax_debug_params,
572 		       "wimax.debug");
573 
574 	snprintf(wimax_gnl_family.name, sizeof(wimax_gnl_family.name),
575 		 "WiMAX");
576 	result = genl_register_family(&wimax_gnl_family);
577 	if (unlikely(result < 0)) {
578 		printk(KERN_ERR "cannot register generic netlink family: %d\n",
579 		       result);
580 		goto error_register_family;
581 	}
582 
583 	for (cnt = 0; cnt < ARRAY_SIZE(wimax_gnl_ops); cnt++) {
584 		result = genl_register_ops(&wimax_gnl_family,
585 					   wimax_gnl_ops[cnt]);
586 		d_printf(4, NULL, "registering generic netlink op code "
587 			 "%u: %d\n", wimax_gnl_ops[cnt]->cmd, result);
588 		if (unlikely(result < 0)) {
589 			printk(KERN_ERR "cannot register generic netlink op "
590 			       "code %u: %d\n",
591 			       wimax_gnl_ops[cnt]->cmd, result);
592 			goto error_register_ops;
593 		}
594 	}
595 
596 	result = genl_register_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
597 	if (result < 0)
598 		goto error_mc_group;
599 	d_fnend(4, NULL, "() = 0\n");
600 	return 0;
601 
602 error_mc_group:
603 error_register_ops:
604 	for (cnt--; cnt >= 0; cnt--)
605 		genl_unregister_ops(&wimax_gnl_family,
606 				    wimax_gnl_ops[cnt]);
607 	genl_unregister_family(&wimax_gnl_family);
608 error_register_family:
609 	d_fnend(4, NULL, "() = %d\n", result);
610 	return result;
611 
612 }
613 module_init(wimax_subsys_init);
614 
615 
616 /* Shutdown the wimax stack */
617 static
wimax_subsys_exit(void)618 void __exit wimax_subsys_exit(void)
619 {
620 	int cnt;
621 	wimax_id_table_release();
622 	genl_unregister_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
623 	for (cnt = ARRAY_SIZE(wimax_gnl_ops) - 1; cnt >= 0; cnt--)
624 		genl_unregister_ops(&wimax_gnl_family,
625 				    wimax_gnl_ops[cnt]);
626 	genl_unregister_family(&wimax_gnl_family);
627 }
628 module_exit(wimax_subsys_exit);
629 
630 MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
631 MODULE_DESCRIPTION("Linux WiMAX stack");
632 MODULE_LICENSE("GPL");
633 
634