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