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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 <linux/module.h>
59#include "wimax-internal.h"
60
61
62#define D_SUBMODULE stack
63#include "debug-levels.h"
64
65static char wimax_debug_params[128];
66module_param_string(debug, wimax_debug_params, sizeof(wimax_debug_params),
67 0644);
68MODULE_PARM_DESC(debug,
69 "String of space-separated NAME:VALUE pairs, where NAMEs "
70 "are the different debug submodules and VALUE are the "
71 "initial debug value to set.");
72
73/*
74 * Authoritative source for the RE_STATE_CHANGE attribute policy
75 *
76 * We don't really use it here, but /me likes to keep the definition
77 * close to where the data is generated.
78 */
79/*
80static const struct nla_policy wimax_gnl_re_status_change[WIMAX_GNL_ATTR_MAX + 1] = {
81 [WIMAX_GNL_STCH_STATE_OLD] = { .type = NLA_U8 },
82 [WIMAX_GNL_STCH_STATE_NEW] = { .type = NLA_U8 },
83};
84*/
85
86
87/*
88 * Allocate a Report State Change message
89 *
90 * @header: save it, you need it for _send()
91 *
92 * Creates and fills a basic state change message; different code
93 * paths can then add more attributes to the message as needed.
94 *
95 * Use wimax_gnl_re_state_change_send() to send the returned skb.
96 *
97 * Returns: skb with the genl message if ok, IS_ERR() ptr on error
98 * with an errno code.
99 */
100static
101struct sk_buff *wimax_gnl_re_state_change_alloc(
102 struct wimax_dev *wimax_dev,
103 enum wimax_st new_state, enum wimax_st old_state,
104 void **header)
105{
106 int result;
107 struct device *dev = wimax_dev_to_dev(wimax_dev);
108 void *data;
109 struct sk_buff *report_skb;
110
111 d_fnstart(3, dev, "(wimax_dev %p new_state %u old_state %u)\n",
112 wimax_dev, new_state, old_state);
113 result = -ENOMEM;
114 report_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
115 if (report_skb == NULL) {
116 dev_err(dev, "RE_STCH: can't create message\n");
117 goto error_new;
118 }
119 data = genlmsg_put(report_skb, 0, wimax_gnl_mcg.id, &wimax_gnl_family,
120 0, WIMAX_GNL_RE_STATE_CHANGE);
121 if (data == NULL) {
122 dev_err(dev, "RE_STCH: can't put data into message\n");
123 goto error_put;
124 }
125 *header = data;
126
127 result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_OLD, old_state);
128 if (result < 0) {
129 dev_err(dev, "RE_STCH: Error adding OLD attr: %d\n", result);
130 goto error_put;
131 }
132 result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_NEW, new_state);
133 if (result < 0) {
134 dev_err(dev, "RE_STCH: Error adding NEW attr: %d\n", result);
135 goto error_put;
136 }
137 result = nla_put_u32(report_skb, WIMAX_GNL_STCH_IFIDX,
138 wimax_dev->net_dev->ifindex);
139 if (result < 0) {
140 dev_err(dev, "RE_STCH: Error adding IFINDEX attribute\n");
141 goto error_put;
142 }
143 d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %p\n",
144 wimax_dev, new_state, old_state, report_skb);
145 return report_skb;
146
147error_put:
148 nlmsg_free(report_skb);
149error_new:
150 d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %d\n",
151 wimax_dev, new_state, old_state, result);
152 return ERR_PTR(result);
153}
154
155
156/*
157 * Send a Report State Change message (as created with _alloc).
158 *
159 * @report_skb: as returned by wimax_gnl_re_state_change_alloc()
160 * @header: as returned by wimax_gnl_re_state_change_alloc()
161 *
162 * Returns: 0 if ok, < 0 errno code on error.
163 *
164 * If the message is NULL, pretend it didn't happen.
165 */
166static
167int wimax_gnl_re_state_change_send(
168 struct wimax_dev *wimax_dev, struct sk_buff *report_skb,
169 void *header)
170{
171 int result = 0;
172 struct device *dev = wimax_dev_to_dev(wimax_dev);
173 d_fnstart(3, dev, "(wimax_dev %p report_skb %p)\n",
174 wimax_dev, report_skb);
175 if (report_skb == NULL) {
176 result = -ENOMEM;
177 goto out;
178 }
179 genlmsg_end(report_skb, header);
180 genlmsg_multicast(report_skb, 0, wimax_gnl_mcg.id, GFP_KERNEL);
181out:
182 d_fnend(3, dev, "(wimax_dev %p report_skb %p) = %d\n",
183 wimax_dev, report_skb, result);
184 return result;
185}
186
187
188static
189void __check_new_state(enum wimax_st old_state, enum wimax_st new_state,
190 unsigned int allowed_states_bm)
191{
192 if (WARN_ON(((1 << new_state) & allowed_states_bm) == 0)) {
193 printk(KERN_ERR "SW BUG! Forbidden state change %u -> %u\n",
194 old_state, new_state);
195 }
196}
197
198
199/*
200 * Set the current state of a WiMAX device [unlocking version of
201 * wimax_state_change().
202 */
203void __wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
204{
205 struct device *dev = wimax_dev_to_dev(wimax_dev);
206 enum wimax_st old_state = wimax_dev->state;
207 struct sk_buff *stch_skb;
208 void *header;
209
210 d_fnstart(3, dev, "(wimax_dev %p new_state %u [old %u])\n",
211 wimax_dev, new_state, old_state);
212
213 if (WARN_ON(new_state >= __WIMAX_ST_INVALID)) {
214 dev_err(dev, "SW BUG: requesting invalid state %u\n",
215 new_state);
216 goto out;
217 }
218 if (old_state == new_state)
219 goto out;
220 header = NULL; /* gcc complains? can't grok why */
221 stch_skb = wimax_gnl_re_state_change_alloc(
222 wimax_dev, new_state, old_state, &header);
223
224 /* Verify the state transition and do exit-from-state actions */
225 switch (old_state) {
226 case __WIMAX_ST_NULL:
227 __check_new_state(old_state, new_state,
228 1 << WIMAX_ST_DOWN);
229 break;
230 case WIMAX_ST_DOWN:
231 __check_new_state(old_state, new_state,
232 1 << __WIMAX_ST_QUIESCING
233 | 1 << WIMAX_ST_UNINITIALIZED
234 | 1 << WIMAX_ST_RADIO_OFF);
235 break;
236 case __WIMAX_ST_QUIESCING:
237 __check_new_state(old_state, new_state, 1 << WIMAX_ST_DOWN);
238 break;
239 case WIMAX_ST_UNINITIALIZED:
240 __check_new_state(old_state, new_state,
241 1 << __WIMAX_ST_QUIESCING
242 | 1 << WIMAX_ST_RADIO_OFF);
243 break;
244 case WIMAX_ST_RADIO_OFF:
245 __check_new_state(old_state, new_state,
246 1 << __WIMAX_ST_QUIESCING
247 | 1 << WIMAX_ST_READY);
248 break;
249 case WIMAX_ST_READY:
250 __check_new_state(old_state, new_state,
251 1 << __WIMAX_ST_QUIESCING
252 | 1 << WIMAX_ST_RADIO_OFF
253 | 1 << WIMAX_ST_SCANNING
254 | 1 << WIMAX_ST_CONNECTING
255 | 1 << WIMAX_ST_CONNECTED);
256 break;
257 case WIMAX_ST_SCANNING:
258 __check_new_state(old_state, new_state,
259 1 << __WIMAX_ST_QUIESCING
260 | 1 << WIMAX_ST_RADIO_OFF
261 | 1 << WIMAX_ST_READY
262 | 1 << WIMAX_ST_CONNECTING
263 | 1 << WIMAX_ST_CONNECTED);
264 break;
265 case WIMAX_ST_CONNECTING:
266 __check_new_state(old_state, new_state,
267 1 << __WIMAX_ST_QUIESCING
268 | 1 << WIMAX_ST_RADIO_OFF
269 | 1 << WIMAX_ST_READY
270 | 1 << WIMAX_ST_SCANNING
271 | 1 << WIMAX_ST_CONNECTED);
272 break;
273 case WIMAX_ST_CONNECTED:
274 __check_new_state(old_state, new_state,
275 1 << __WIMAX_ST_QUIESCING
276 | 1 << WIMAX_ST_RADIO_OFF
277 | 1 << WIMAX_ST_READY);
278 netif_tx_disable(wimax_dev->net_dev);
279 netif_carrier_off(wimax_dev->net_dev);
280 break;
281 case __WIMAX_ST_INVALID:
282 default:
283 dev_err(dev, "SW BUG: wimax_dev %p is in unknown state %u\n",
284 wimax_dev, wimax_dev->state);
285 WARN_ON(1);
286 goto out;
287 }
288
289 /* Execute the actions of entry to the new state */
290 switch (new_state) {
291 case __WIMAX_ST_NULL:
292 dev_err(dev, "SW BUG: wimax_dev %p entering NULL state "
293 "from %u\n", wimax_dev, wimax_dev->state);
294 WARN_ON(1); /* Nobody can enter this state */
295 break;
296 case WIMAX_ST_DOWN:
297 break;
298 case __WIMAX_ST_QUIESCING:
299 break;
300 case WIMAX_ST_UNINITIALIZED:
301 break;
302 case WIMAX_ST_RADIO_OFF:
303 break;
304 case WIMAX_ST_READY:
305 break;
306 case WIMAX_ST_SCANNING:
307 break;
308 case WIMAX_ST_CONNECTING:
309 break;
310 case WIMAX_ST_CONNECTED:
311 netif_carrier_on(wimax_dev->net_dev);
312 netif_wake_queue(wimax_dev->net_dev);
313 break;
314 case __WIMAX_ST_INVALID:
315 default:
316 BUG();
317 }
318 __wimax_state_set(wimax_dev, new_state);
319 if (!IS_ERR(stch_skb))
320 wimax_gnl_re_state_change_send(wimax_dev, stch_skb, header);
321out:
322 d_fnend(3, dev, "(wimax_dev %p new_state %u [old %u]) = void\n",
323 wimax_dev, new_state, old_state);
324}
325
326
327/**
328 * wimax_state_change - Set the current state of a WiMAX device
329 *
330 * @wimax_dev: WiMAX device descriptor (properly referenced)
331 * @new_state: New state to switch to
332 *
333 * This implements the state changes for the wimax devices. It will
334 *
335 * - verify that the state transition is legal (for now it'll just
336 * print a warning if not) according to the table in
337 * linux/wimax.h's documentation for 'enum wimax_st'.
338 *
339 * - perform the actions needed for leaving the current state and
340 * whichever are needed for entering the new state.
341 *
342 * - issue a report to user space indicating the new state (and an
343 * optional payload with information about the new state).
344 *
345 * NOTE: @wimax_dev must be locked
346 */
347void wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
348{
349 /*
350 * A driver cannot take the wimax_dev out of the
351 * __WIMAX_ST_NULL state unless by calling wimax_dev_add(). If
352 * the wimax_dev's state is still NULL, we ignore any request
353 * to change its state because it means it hasn't been yet
354 * registered.
355 *
356 * There is no need to complain about it, as routines that
357 * call this might be shared from different code paths that
358 * are called before or after wimax_dev_add() has done its
359 * job.
360 */
361 mutex_lock(&wimax_dev->mutex);
362 if (wimax_dev->state > __WIMAX_ST_NULL)
363 __wimax_state_change(wimax_dev, new_state);
364 mutex_unlock(&wimax_dev->mutex);
365}
366EXPORT_SYMBOL_GPL(wimax_state_change);
367
368
369/**
370 * wimax_state_get() - Return the current state of a WiMAX device
371 *
372 * @wimax_dev: WiMAX device descriptor
373 *
374 * Returns: Current state of the device according to its driver.
375 */
376enum wimax_st wimax_state_get(struct wimax_dev *wimax_dev)
377{
378 enum wimax_st state;
379 mutex_lock(&wimax_dev->mutex);
380 state = wimax_dev->state;
381 mutex_unlock(&wimax_dev->mutex);
382 return state;
383}
384EXPORT_SYMBOL_GPL(wimax_state_get);
385
386
387/**
388 * wimax_dev_init - initialize a newly allocated instance
389 *
390 * @wimax_dev: WiMAX device descriptor to initialize.
391 *
392 * Initializes fields of a freshly allocated @wimax_dev instance. This
393 * function assumes that after allocation, the memory occupied by
394 * @wimax_dev was zeroed.
395 */
396void wimax_dev_init(struct wimax_dev *wimax_dev)
397{
398 INIT_LIST_HEAD(&wimax_dev->id_table_node);
399 __wimax_state_set(wimax_dev, __WIMAX_ST_NULL);
400 mutex_init(&wimax_dev->mutex);
401 mutex_init(&wimax_dev->mutex_reset);
402}
403EXPORT_SYMBOL_GPL(wimax_dev_init);
404
405/*
406 * This extern is declared here because it's easier to keep track --
407 * both declarations are a list of the same
408 */
409extern struct genl_ops
410 wimax_gnl_msg_from_user,
411 wimax_gnl_reset,
412 wimax_gnl_rfkill,
413 wimax_gnl_state_get;
414
415static
416struct genl_ops *wimax_gnl_ops[] = {
417 &wimax_gnl_msg_from_user,
418 &wimax_gnl_reset,
419 &wimax_gnl_rfkill,
420 &wimax_gnl_state_get,
421};
422
423
424static
425size_t wimax_addr_scnprint(char *addr_str, size_t addr_str_size,
426 unsigned char *addr, size_t addr_len)
427{
428 unsigned int cnt, total;
429
430 for (total = cnt = 0; cnt < addr_len; cnt++)
431 total += scnprintf(addr_str + total, addr_str_size - total,
432 "%02x%c", addr[cnt],
433 cnt == addr_len - 1 ? '\0' : ':');
434 return total;
435}
436
437
438/**
439 * wimax_dev_add - Register a new WiMAX device
440 *
441 * @wimax_dev: WiMAX device descriptor (as embedded in your @net_dev's
442 * priv data). You must have called wimax_dev_init() on it before.
443 *
444 * @net_dev: net device the @wimax_dev is associated with. The
445 * function expects SET_NETDEV_DEV() and register_netdev() were
446 * already called on it.
447 *
448 * Registers the new WiMAX device, sets up the user-kernel control
449 * interface (generic netlink) and common WiMAX infrastructure.
450 *
451 * Note that the parts that will allow interaction with user space are
452 * setup at the very end, when the rest is in place, as once that
453 * happens, the driver might get user space control requests via
454 * netlink or from debugfs that might translate into calls into
455 * wimax_dev->op_*().
456 */
457int wimax_dev_add(struct wimax_dev *wimax_dev, struct net_device *net_dev)
458{
459 int result;
460 struct device *dev = net_dev->dev.parent;
461 char addr_str[32];
462
463 d_fnstart(3, dev, "(wimax_dev %p net_dev %p)\n", wimax_dev, net_dev);
464
465 /* Do the RFKILL setup before locking, as RFKILL will call
466 * into our functions. */
467 wimax_dev->net_dev = net_dev;
468 result = wimax_rfkill_add(wimax_dev);
469 if (result < 0)
470 goto error_rfkill_add;
471
472 /* Set up user-space interaction */
473 mutex_lock(&wimax_dev->mutex);
474 wimax_id_table_add(wimax_dev);
475 result = wimax_debugfs_add(wimax_dev);
476 if (result < 0) {
477 dev_err(dev, "cannot initialize debugfs: %d\n",
478 result);
479 goto error_debugfs_add;
480 }
481
482 __wimax_state_set(wimax_dev, WIMAX_ST_DOWN);
483 mutex_unlock(&wimax_dev->mutex);
484
485 wimax_addr_scnprint(addr_str, sizeof(addr_str),
486 net_dev->dev_addr, net_dev->addr_len);
487 dev_err(dev, "WiMAX interface %s (%s) ready\n",
488 net_dev->name, addr_str);
489 d_fnend(3, dev, "(wimax_dev %p net_dev %p) = 0\n", wimax_dev, net_dev);
490 return 0;
491
492error_debugfs_add:
493 wimax_id_table_rm(wimax_dev);
494 mutex_unlock(&wimax_dev->mutex);
495 wimax_rfkill_rm(wimax_dev);
496error_rfkill_add:
497 d_fnend(3, dev, "(wimax_dev %p net_dev %p) = %d\n",
498 wimax_dev, net_dev, result);
499 return result;
500}
501EXPORT_SYMBOL_GPL(wimax_dev_add);
502
503
504/**
505 * wimax_dev_rm - Unregister an existing WiMAX device
506 *
507 * @wimax_dev: WiMAX device descriptor
508 *
509 * Unregisters a WiMAX device previously registered for use with
510 * wimax_add_rm().
511 *
512 * IMPORTANT! Must call before calling unregister_netdev().
513 *
514 * After this function returns, you will not get any more user space
515 * control requests (via netlink or debugfs) and thus to wimax_dev->ops.
516 *
517 * Reentrancy control is ensured by setting the state to
518 * %__WIMAX_ST_QUIESCING. rfkill operations coming through
519 * wimax_*rfkill*() will be stopped by the quiescing state; ops coming
520 * from the rfkill subsystem will be stopped by the support being
521 * removed by wimax_rfkill_rm().
522 */
523void wimax_dev_rm(struct wimax_dev *wimax_dev)
524{
525 d_fnstart(3, NULL, "(wimax_dev %p)\n", wimax_dev);
526
527 mutex_lock(&wimax_dev->mutex);
528 __wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
529 wimax_debugfs_rm(wimax_dev);
530 wimax_id_table_rm(wimax_dev);
531 __wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
532 mutex_unlock(&wimax_dev->mutex);
533 wimax_rfkill_rm(wimax_dev);
534 d_fnend(3, NULL, "(wimax_dev %p) = void\n", wimax_dev);
535}
536EXPORT_SYMBOL_GPL(wimax_dev_rm);
537
538
539/* Debug framework control of debug levels */
540struct d_level D_LEVEL[] = {
541 D_SUBMODULE_DEFINE(debugfs),
542 D_SUBMODULE_DEFINE(id_table),
543 D_SUBMODULE_DEFINE(op_msg),
544 D_SUBMODULE_DEFINE(op_reset),
545 D_SUBMODULE_DEFINE(op_rfkill),
546 D_SUBMODULE_DEFINE(op_state_get),
547 D_SUBMODULE_DEFINE(stack),
548};
549size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
550
551
552struct genl_family wimax_gnl_family = {
553 .id = GENL_ID_GENERATE,
554 .name = "WiMAX",
555 .version = WIMAX_GNL_VERSION,
556 .hdrsize = 0,
557 .maxattr = WIMAX_GNL_ATTR_MAX,
558};
559
560struct genl_multicast_group wimax_gnl_mcg = {
561 .name = "msg",
562};
563
564
565
566/* Shutdown the wimax stack */
567static
568int __init wimax_subsys_init(void)
569{
570 int result, cnt;
571
572 d_fnstart(4, NULL, "()\n");
573 d_parse_params(D_LEVEL, D_LEVEL_SIZE, wimax_debug_params,
574 "wimax.debug");
575
576 snprintf(wimax_gnl_family.name, sizeof(wimax_gnl_family.name),
577 "WiMAX");
578 result = genl_register_family(&wimax_gnl_family);
579 if (unlikely(result < 0)) {
580 printk(KERN_ERR "cannot register generic netlink family: %d\n",
581 result);
582 goto error_register_family;
583 }
584
585 for (cnt = 0; cnt < ARRAY_SIZE(wimax_gnl_ops); cnt++) {
586 result = genl_register_ops(&wimax_gnl_family,
587 wimax_gnl_ops[cnt]);
588 d_printf(4, NULL, "registering generic netlink op code "
589 "%u: %d\n", wimax_gnl_ops[cnt]->cmd, result);
590 if (unlikely(result < 0)) {
591 printk(KERN_ERR "cannot register generic netlink op "
592 "code %u: %d\n",
593 wimax_gnl_ops[cnt]->cmd, result);
594 goto error_register_ops;
595 }
596 }
597
598 result = genl_register_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
599 if (result < 0)
600 goto error_mc_group;
601 d_fnend(4, NULL, "() = 0\n");
602 return 0;
603
604error_mc_group:
605error_register_ops:
606 for (cnt--; cnt >= 0; cnt--)
607 genl_unregister_ops(&wimax_gnl_family,
608 wimax_gnl_ops[cnt]);
609 genl_unregister_family(&wimax_gnl_family);
610error_register_family:
611 d_fnend(4, NULL, "() = %d\n", result);
612 return result;
613
614}
615module_init(wimax_subsys_init);
616
617
618/* Shutdown the wimax stack */
619static
620void __exit wimax_subsys_exit(void)
621{
622 int cnt;
623 wimax_id_table_release();
624 genl_unregister_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
625 for (cnt = ARRAY_SIZE(wimax_gnl_ops) - 1; cnt >= 0; cnt--)
626 genl_unregister_ops(&wimax_gnl_family,
627 wimax_gnl_ops[cnt]);
628 genl_unregister_family(&wimax_gnl_family);
629}
630module_exit(wimax_subsys_exit);
631
632MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
633MODULE_DESCRIPTION("Linux WiMAX stack");
634MODULE_LICENSE("GPL");
635