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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Linux WiMAX
4 * Initialization, addition and removal of wimax devices
5 *
6 * Copyright (C) 2005-2006 Intel Corporation <linux-wimax@intel.com>
7 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8 *
9 * This implements:
10 *
11 * - basic life cycle of 'struct wimax_dev' [wimax_dev_*()]; on
12 * addition/registration initialize all subfields and allocate
13 * generic netlink resources for user space communication. On
14 * removal/unregistration, undo all that.
15 *
16 * - device state machine [wimax_state_change()] and support to send
17 * reports to user space when the state changes
18 * [wimax_gnl_re_state_change*()].
19 *
20 * See include/net/wimax.h for rationales and design.
21 *
22 * ROADMAP
23 *
24 * [__]wimax_state_change() Called by drivers to update device's state
25 * wimax_gnl_re_state_change_alloc()
26 * wimax_gnl_re_state_change_send()
27 *
28 * wimax_dev_init() Init a device
29 * wimax_dev_add() Register
30 * wimax_rfkill_add()
31 * wimax_gnl_add() Register all the generic netlink resources.
32 * wimax_id_table_add()
33 * wimax_dev_rm() Unregister
34 * wimax_id_table_rm()
35 * wimax_gnl_rm()
36 * wimax_rfkill_rm()
37 */
38#include <linux/device.h>
39#include <linux/gfp.h>
40#include <net/genetlink.h>
41#include <linux/netdevice.h>
42#include <linux/wimax.h>
43#include <linux/module.h>
44#include "wimax-internal.h"
45
46
47#define D_SUBMODULE stack
48#include "debug-levels.h"
49
50static char wimax_debug_params[128];
51module_param_string(debug, wimax_debug_params, sizeof(wimax_debug_params),
52 0644);
53MODULE_PARM_DESC(debug,
54 "String of space-separated NAME:VALUE pairs, where NAMEs "
55 "are the different debug submodules and VALUE are the "
56 "initial debug value to set.");
57
58/*
59 * Authoritative source for the RE_STATE_CHANGE attribute policy
60 *
61 * We don't really use it here, but /me likes to keep the definition
62 * close to where the data is generated.
63 */
64/*
65static const struct nla_policy wimax_gnl_re_status_change[WIMAX_GNL_ATTR_MAX + 1] = {
66 [WIMAX_GNL_STCH_STATE_OLD] = { .type = NLA_U8 },
67 [WIMAX_GNL_STCH_STATE_NEW] = { .type = NLA_U8 },
68};
69*/
70
71
72/*
73 * Allocate a Report State Change message
74 *
75 * @header: save it, you need it for _send()
76 *
77 * Creates and fills a basic state change message; different code
78 * paths can then add more attributes to the message as needed.
79 *
80 * Use wimax_gnl_re_state_change_send() to send the returned skb.
81 *
82 * Returns: skb with the genl message if ok, IS_ERR() ptr on error
83 * with an errno code.
84 */
85static
86struct sk_buff *wimax_gnl_re_state_change_alloc(
87 struct wimax_dev *wimax_dev,
88 enum wimax_st new_state, enum wimax_st old_state,
89 void **header)
90{
91 int result;
92 struct device *dev = wimax_dev_to_dev(wimax_dev);
93 void *data;
94 struct sk_buff *report_skb;
95
96 d_fnstart(3, dev, "(wimax_dev %p new_state %u old_state %u)\n",
97 wimax_dev, new_state, old_state);
98 result = -ENOMEM;
99 report_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
100 if (report_skb == NULL) {
101 dev_err(dev, "RE_STCH: can't create message\n");
102 goto error_new;
103 }
104 /* FIXME: sending a group ID as the seq is wrong */
105 data = genlmsg_put(report_skb, 0, wimax_gnl_family.mcgrp_offset,
106 &wimax_gnl_family, 0, WIMAX_GNL_RE_STATE_CHANGE);
107 if (data == NULL) {
108 dev_err(dev, "RE_STCH: can't put data into message\n");
109 goto error_put;
110 }
111 *header = data;
112
113 result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_OLD, old_state);
114 if (result < 0) {
115 dev_err(dev, "RE_STCH: Error adding OLD attr: %d\n", result);
116 goto error_put;
117 }
118 result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_NEW, new_state);
119 if (result < 0) {
120 dev_err(dev, "RE_STCH: Error adding NEW attr: %d\n", result);
121 goto error_put;
122 }
123 result = nla_put_u32(report_skb, WIMAX_GNL_STCH_IFIDX,
124 wimax_dev->net_dev->ifindex);
125 if (result < 0) {
126 dev_err(dev, "RE_STCH: Error adding IFINDEX attribute\n");
127 goto error_put;
128 }
129 d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %p\n",
130 wimax_dev, new_state, old_state, report_skb);
131 return report_skb;
132
133error_put:
134 nlmsg_free(report_skb);
135error_new:
136 d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %d\n",
137 wimax_dev, new_state, old_state, result);
138 return ERR_PTR(result);
139}
140
141
142/*
143 * Send a Report State Change message (as created with _alloc).
144 *
145 * @report_skb: as returned by wimax_gnl_re_state_change_alloc()
146 * @header: as returned by wimax_gnl_re_state_change_alloc()
147 *
148 * Returns: 0 if ok, < 0 errno code on error.
149 *
150 * If the message is NULL, pretend it didn't happen.
151 */
152static
153int wimax_gnl_re_state_change_send(
154 struct wimax_dev *wimax_dev, struct sk_buff *report_skb,
155 void *header)
156{
157 int result = 0;
158 struct device *dev = wimax_dev_to_dev(wimax_dev);
159 d_fnstart(3, dev, "(wimax_dev %p report_skb %p)\n",
160 wimax_dev, report_skb);
161 if (report_skb == NULL) {
162 result = -ENOMEM;
163 goto out;
164 }
165 genlmsg_end(report_skb, header);
166 genlmsg_multicast(&wimax_gnl_family, report_skb, 0, 0, GFP_KERNEL);
167out:
168 d_fnend(3, dev, "(wimax_dev %p report_skb %p) = %d\n",
169 wimax_dev, report_skb, result);
170 return result;
171}
172
173
174static
175void __check_new_state(enum wimax_st old_state, enum wimax_st new_state,
176 unsigned int allowed_states_bm)
177{
178 if (WARN_ON(((1 << new_state) & allowed_states_bm) == 0)) {
179 pr_err("SW BUG! Forbidden state change %u -> %u\n",
180 old_state, new_state);
181 }
182}
183
184
185/*
186 * Set the current state of a WiMAX device [unlocking version of
187 * wimax_state_change().
188 */
189void __wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
190{
191 struct device *dev = wimax_dev_to_dev(wimax_dev);
192 enum wimax_st old_state = wimax_dev->state;
193 struct sk_buff *stch_skb;
194 void *header;
195
196 d_fnstart(3, dev, "(wimax_dev %p new_state %u [old %u])\n",
197 wimax_dev, new_state, old_state);
198
199 if (WARN_ON(new_state >= __WIMAX_ST_INVALID)) {
200 dev_err(dev, "SW BUG: requesting invalid state %u\n",
201 new_state);
202 goto out;
203 }
204 if (old_state == new_state)
205 goto out;
206 header = NULL; /* gcc complains? can't grok why */
207 stch_skb = wimax_gnl_re_state_change_alloc(
208 wimax_dev, new_state, old_state, &header);
209
210 /* Verify the state transition and do exit-from-state actions */
211 switch (old_state) {
212 case __WIMAX_ST_NULL:
213 __check_new_state(old_state, new_state,
214 1 << WIMAX_ST_DOWN);
215 break;
216 case WIMAX_ST_DOWN:
217 __check_new_state(old_state, new_state,
218 1 << __WIMAX_ST_QUIESCING
219 | 1 << WIMAX_ST_UNINITIALIZED
220 | 1 << WIMAX_ST_RADIO_OFF);
221 break;
222 case __WIMAX_ST_QUIESCING:
223 __check_new_state(old_state, new_state, 1 << WIMAX_ST_DOWN);
224 break;
225 case WIMAX_ST_UNINITIALIZED:
226 __check_new_state(old_state, new_state,
227 1 << __WIMAX_ST_QUIESCING
228 | 1 << WIMAX_ST_RADIO_OFF);
229 break;
230 case WIMAX_ST_RADIO_OFF:
231 __check_new_state(old_state, new_state,
232 1 << __WIMAX_ST_QUIESCING
233 | 1 << WIMAX_ST_READY);
234 break;
235 case WIMAX_ST_READY:
236 __check_new_state(old_state, new_state,
237 1 << __WIMAX_ST_QUIESCING
238 | 1 << WIMAX_ST_RADIO_OFF
239 | 1 << WIMAX_ST_SCANNING
240 | 1 << WIMAX_ST_CONNECTING
241 | 1 << WIMAX_ST_CONNECTED);
242 break;
243 case WIMAX_ST_SCANNING:
244 __check_new_state(old_state, new_state,
245 1 << __WIMAX_ST_QUIESCING
246 | 1 << WIMAX_ST_RADIO_OFF
247 | 1 << WIMAX_ST_READY
248 | 1 << WIMAX_ST_CONNECTING
249 | 1 << WIMAX_ST_CONNECTED);
250 break;
251 case WIMAX_ST_CONNECTING:
252 __check_new_state(old_state, new_state,
253 1 << __WIMAX_ST_QUIESCING
254 | 1 << WIMAX_ST_RADIO_OFF
255 | 1 << WIMAX_ST_READY
256 | 1 << WIMAX_ST_SCANNING
257 | 1 << WIMAX_ST_CONNECTED);
258 break;
259 case WIMAX_ST_CONNECTED:
260 __check_new_state(old_state, new_state,
261 1 << __WIMAX_ST_QUIESCING
262 | 1 << WIMAX_ST_RADIO_OFF
263 | 1 << WIMAX_ST_READY);
264 netif_tx_disable(wimax_dev->net_dev);
265 netif_carrier_off(wimax_dev->net_dev);
266 break;
267 case __WIMAX_ST_INVALID:
268 default:
269 dev_err(dev, "SW BUG: wimax_dev %p is in unknown state %u\n",
270 wimax_dev, wimax_dev->state);
271 WARN_ON(1);
272 goto out;
273 }
274
275 /* Execute the actions of entry to the new state */
276 switch (new_state) {
277 case __WIMAX_ST_NULL:
278 dev_err(dev, "SW BUG: wimax_dev %p entering NULL state "
279 "from %u\n", wimax_dev, wimax_dev->state);
280 WARN_ON(1); /* Nobody can enter this state */
281 break;
282 case WIMAX_ST_DOWN:
283 break;
284 case __WIMAX_ST_QUIESCING:
285 break;
286 case WIMAX_ST_UNINITIALIZED:
287 break;
288 case WIMAX_ST_RADIO_OFF:
289 break;
290 case WIMAX_ST_READY:
291 break;
292 case WIMAX_ST_SCANNING:
293 break;
294 case WIMAX_ST_CONNECTING:
295 break;
296 case WIMAX_ST_CONNECTED:
297 netif_carrier_on(wimax_dev->net_dev);
298 netif_wake_queue(wimax_dev->net_dev);
299 break;
300 case __WIMAX_ST_INVALID:
301 default:
302 BUG();
303 }
304 __wimax_state_set(wimax_dev, new_state);
305 if (!IS_ERR(stch_skb))
306 wimax_gnl_re_state_change_send(wimax_dev, stch_skb, header);
307out:
308 d_fnend(3, dev, "(wimax_dev %p new_state %u [old %u]) = void\n",
309 wimax_dev, new_state, old_state);
310}
311
312
313/**
314 * wimax_state_change - Set the current state of a WiMAX device
315 *
316 * @wimax_dev: WiMAX device descriptor (properly referenced)
317 * @new_state: New state to switch to
318 *
319 * This implements the state changes for the wimax devices. It will
320 *
321 * - verify that the state transition is legal (for now it'll just
322 * print a warning if not) according to the table in
323 * linux/wimax.h's documentation for 'enum wimax_st'.
324 *
325 * - perform the actions needed for leaving the current state and
326 * whichever are needed for entering the new state.
327 *
328 * - issue a report to user space indicating the new state (and an
329 * optional payload with information about the new state).
330 *
331 * NOTE: @wimax_dev must be locked
332 */
333void wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
334{
335 /*
336 * A driver cannot take the wimax_dev out of the
337 * __WIMAX_ST_NULL state unless by calling wimax_dev_add(). If
338 * the wimax_dev's state is still NULL, we ignore any request
339 * to change its state because it means it hasn't been yet
340 * registered.
341 *
342 * There is no need to complain about it, as routines that
343 * call this might be shared from different code paths that
344 * are called before or after wimax_dev_add() has done its
345 * job.
346 */
347 mutex_lock(&wimax_dev->mutex);
348 if (wimax_dev->state > __WIMAX_ST_NULL)
349 __wimax_state_change(wimax_dev, new_state);
350 mutex_unlock(&wimax_dev->mutex);
351}
352EXPORT_SYMBOL_GPL(wimax_state_change);
353
354
355/**
356 * wimax_state_get() - Return the current state of a WiMAX device
357 *
358 * @wimax_dev: WiMAX device descriptor
359 *
360 * Returns: Current state of the device according to its driver.
361 */
362enum wimax_st wimax_state_get(struct wimax_dev *wimax_dev)
363{
364 enum wimax_st state;
365 mutex_lock(&wimax_dev->mutex);
366 state = wimax_dev->state;
367 mutex_unlock(&wimax_dev->mutex);
368 return state;
369}
370EXPORT_SYMBOL_GPL(wimax_state_get);
371
372
373/**
374 * wimax_dev_init - initialize a newly allocated instance
375 *
376 * @wimax_dev: WiMAX device descriptor to initialize.
377 *
378 * Initializes fields of a freshly allocated @wimax_dev instance. This
379 * function assumes that after allocation, the memory occupied by
380 * @wimax_dev was zeroed.
381 */
382void wimax_dev_init(struct wimax_dev *wimax_dev)
383{
384 INIT_LIST_HEAD(&wimax_dev->id_table_node);
385 __wimax_state_set(wimax_dev, __WIMAX_ST_NULL);
386 mutex_init(&wimax_dev->mutex);
387 mutex_init(&wimax_dev->mutex_reset);
388}
389EXPORT_SYMBOL_GPL(wimax_dev_init);
390
391static const struct nla_policy wimax_gnl_policy[WIMAX_GNL_ATTR_MAX + 1] = {
392 [WIMAX_GNL_RESET_IFIDX] = { .type = NLA_U32, },
393 [WIMAX_GNL_RFKILL_IFIDX] = { .type = NLA_U32, },
394 [WIMAX_GNL_RFKILL_STATE] = {
395 .type = NLA_U32 /* enum wimax_rf_state */
396 },
397 [WIMAX_GNL_STGET_IFIDX] = { .type = NLA_U32, },
398 [WIMAX_GNL_MSG_IFIDX] = { .type = NLA_U32, },
399 [WIMAX_GNL_MSG_DATA] = {
400 .type = NLA_UNSPEC, /* libnl doesn't grok BINARY yet */
401 },
402};
403
404static const struct genl_ops wimax_gnl_ops[] = {
405 {
406 .cmd = WIMAX_GNL_OP_MSG_FROM_USER,
407 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
408 .flags = GENL_ADMIN_PERM,
409 .doit = wimax_gnl_doit_msg_from_user,
410 },
411 {
412 .cmd = WIMAX_GNL_OP_RESET,
413 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
414 .flags = GENL_ADMIN_PERM,
415 .doit = wimax_gnl_doit_reset,
416 },
417 {
418 .cmd = WIMAX_GNL_OP_RFKILL,
419 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
420 .flags = GENL_ADMIN_PERM,
421 .doit = wimax_gnl_doit_rfkill,
422 },
423 {
424 .cmd = WIMAX_GNL_OP_STATE_GET,
425 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
426 .flags = GENL_ADMIN_PERM,
427 .doit = wimax_gnl_doit_state_get,
428 },
429};
430
431
432static
433size_t wimax_addr_scnprint(char *addr_str, size_t addr_str_size,
434 unsigned char *addr, size_t addr_len)
435{
436 unsigned int cnt, total;
437
438 for (total = cnt = 0; cnt < addr_len; cnt++)
439 total += scnprintf(addr_str + total, addr_str_size - total,
440 "%02x%c", addr[cnt],
441 cnt == addr_len - 1 ? '\0' : ':');
442 return total;
443}
444
445
446/**
447 * wimax_dev_add - Register a new WiMAX device
448 *
449 * @wimax_dev: WiMAX device descriptor (as embedded in your @net_dev's
450 * priv data). You must have called wimax_dev_init() on it before.
451 *
452 * @net_dev: net device the @wimax_dev is associated with. The
453 * function expects SET_NETDEV_DEV() and register_netdev() were
454 * already called on it.
455 *
456 * Registers the new WiMAX device, sets up the user-kernel control
457 * interface (generic netlink) and common WiMAX infrastructure.
458 *
459 * Note that the parts that will allow interaction with user space are
460 * setup at the very end, when the rest is in place, as once that
461 * happens, the driver might get user space control requests via
462 * netlink or from debugfs that might translate into calls into
463 * wimax_dev->op_*().
464 */
465int wimax_dev_add(struct wimax_dev *wimax_dev, struct net_device *net_dev)
466{
467 int result;
468 struct device *dev = net_dev->dev.parent;
469 char addr_str[32];
470
471 d_fnstart(3, dev, "(wimax_dev %p net_dev %p)\n", wimax_dev, net_dev);
472
473 /* Do the RFKILL setup before locking, as RFKILL will call
474 * into our functions.
475 */
476 wimax_dev->net_dev = net_dev;
477 result = wimax_rfkill_add(wimax_dev);
478 if (result < 0)
479 goto error_rfkill_add;
480
481 /* Set up user-space interaction */
482 mutex_lock(&wimax_dev->mutex);
483 wimax_id_table_add(wimax_dev);
484 wimax_debugfs_add(wimax_dev);
485
486 __wimax_state_set(wimax_dev, WIMAX_ST_DOWN);
487 mutex_unlock(&wimax_dev->mutex);
488
489 wimax_addr_scnprint(addr_str, sizeof(addr_str),
490 net_dev->dev_addr, net_dev->addr_len);
491 dev_err(dev, "WiMAX interface %s (%s) ready\n",
492 net_dev->name, addr_str);
493 d_fnend(3, dev, "(wimax_dev %p net_dev %p) = 0\n", wimax_dev, net_dev);
494 return 0;
495
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
552static const struct genl_multicast_group wimax_gnl_mcgrps[] = {
553 { .name = "msg", },
554};
555
556struct genl_family wimax_gnl_family __ro_after_init = {
557 .name = "WiMAX",
558 .version = WIMAX_GNL_VERSION,
559 .hdrsize = 0,
560 .maxattr = WIMAX_GNL_ATTR_MAX,
561 .policy = wimax_gnl_policy,
562 .module = THIS_MODULE,
563 .ops = wimax_gnl_ops,
564 .n_ops = ARRAY_SIZE(wimax_gnl_ops),
565 .mcgrps = wimax_gnl_mcgrps,
566 .n_mcgrps = ARRAY_SIZE(wimax_gnl_mcgrps),
567};
568
569
570
571/* Shutdown the wimax stack */
572static
573int __init wimax_subsys_init(void)
574{
575 int result;
576
577 d_fnstart(4, NULL, "()\n");
578 d_parse_params(D_LEVEL, D_LEVEL_SIZE, wimax_debug_params,
579 "wimax.debug");
580
581 result = genl_register_family(&wimax_gnl_family);
582 if (unlikely(result < 0)) {
583 pr_err("cannot register generic netlink family: %d\n", result);
584 goto error_register_family;
585 }
586
587 d_fnend(4, NULL, "() = 0\n");
588 return 0;
589
590error_register_family:
591 d_fnend(4, NULL, "() = %d\n", result);
592 return result;
593
594}
595module_init(wimax_subsys_init);
596
597
598/* Shutdown the wimax stack */
599static
600void __exit wimax_subsys_exit(void)
601{
602 wimax_id_table_release();
603 genl_unregister_family(&wimax_gnl_family);
604}
605module_exit(wimax_subsys_exit);
606
607MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
608MODULE_DESCRIPTION("Linux WiMAX stack");
609MODULE_LICENSE("GPL");