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-rw-r--r--net/wimax/stack.c599
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diff --git a/net/wimax/stack.c b/net/wimax/stack.c
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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 <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/*
70static const
71struct 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 */
91static
92struct 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
138error_put:
139 nlmsg_free(report_skb);
140error_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 */
157static
158int 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 goto out;
168 genlmsg_end(report_skb, header);
169 result = genlmsg_multicast(report_skb, 0, wimax_gnl_mcg.id, GFP_KERNEL);
170 if (result == -ESRCH) /* Nobody connected, ignore it */
171 result = 0; /* btw, the skb is freed already */
172 if (result < 0) {
173 dev_err(dev, "RE_STCH: Error sending: %d\n", result);
174 nlmsg_free(report_skb);
175 }
176out:
177 d_fnend(3, dev, "(wimax_dev %p report_skb %p) = %d\n",
178 wimax_dev, report_skb, result);
179 return result;
180}
181
182
183static
184void __check_new_state(enum wimax_st old_state, enum wimax_st new_state,
185 unsigned allowed_states_bm)
186{
187 if (WARN_ON(((1 << new_state) & allowed_states_bm) == 0)) {
188 printk(KERN_ERR "SW BUG! Forbidden state change %u -> %u\n",
189 old_state, new_state);
190 }
191}
192
193
194/*
195 * Set the current state of a WiMAX device [unlocking version of
196 * wimax_state_change().
197 */
198void __wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
199{
200 struct device *dev = wimax_dev_to_dev(wimax_dev);
201 enum wimax_st old_state = wimax_dev->state;
202 struct sk_buff *stch_skb;
203 void *header;
204
205 d_fnstart(3, dev, "(wimax_dev %p new_state %u [old %u])\n",
206 wimax_dev, new_state, old_state);
207
208 if (WARN_ON(new_state >= __WIMAX_ST_INVALID)) {
209 dev_err(dev, "SW BUG: requesting invalid state %u\n",
210 new_state);
211 goto out;
212 }
213 if (old_state == new_state)
214 goto out;
215 header = NULL; /* gcc complains? can't grok why */
216 stch_skb = wimax_gnl_re_state_change_alloc(
217 wimax_dev, new_state, old_state, &header);
218
219 /* Verify the state transition and do exit-from-state actions */
220 switch (old_state) {
221 case __WIMAX_ST_NULL:
222 __check_new_state(old_state, new_state,
223 1 << WIMAX_ST_DOWN);
224 break;
225 case WIMAX_ST_DOWN:
226 __check_new_state(old_state, new_state,
227 1 << __WIMAX_ST_QUIESCING
228 | 1 << WIMAX_ST_UNINITIALIZED
229 | 1 << WIMAX_ST_RADIO_OFF);
230 break;
231 case __WIMAX_ST_QUIESCING:
232 __check_new_state(old_state, new_state, 1 << WIMAX_ST_DOWN);
233 break;
234 case WIMAX_ST_UNINITIALIZED:
235 __check_new_state(old_state, new_state,
236 1 << __WIMAX_ST_QUIESCING
237 | 1 << WIMAX_ST_RADIO_OFF);
238 break;
239 case WIMAX_ST_RADIO_OFF:
240 __check_new_state(old_state, new_state,
241 1 << __WIMAX_ST_QUIESCING
242 | 1 << WIMAX_ST_READY);
243 break;
244 case WIMAX_ST_READY:
245 __check_new_state(old_state, new_state,
246 1 << __WIMAX_ST_QUIESCING
247 | 1 << WIMAX_ST_RADIO_OFF
248 | 1 << WIMAX_ST_SCANNING
249 | 1 << WIMAX_ST_CONNECTING
250 | 1 << WIMAX_ST_CONNECTED);
251 break;
252 case WIMAX_ST_SCANNING:
253 __check_new_state(old_state, new_state,
254 1 << __WIMAX_ST_QUIESCING
255 | 1 << WIMAX_ST_RADIO_OFF
256 | 1 << WIMAX_ST_READY
257 | 1 << WIMAX_ST_CONNECTING
258 | 1 << WIMAX_ST_CONNECTED);
259 break;
260 case WIMAX_ST_CONNECTING:
261 __check_new_state(old_state, new_state,
262 1 << __WIMAX_ST_QUIESCING
263 | 1 << WIMAX_ST_RADIO_OFF
264 | 1 << WIMAX_ST_READY
265 | 1 << WIMAX_ST_SCANNING
266 | 1 << WIMAX_ST_CONNECTED);
267 break;
268 case WIMAX_ST_CONNECTED:
269 __check_new_state(old_state, new_state,
270 1 << __WIMAX_ST_QUIESCING
271 | 1 << WIMAX_ST_RADIO_OFF
272 | 1 << WIMAX_ST_READY);
273 netif_tx_disable(wimax_dev->net_dev);
274 netif_carrier_off(wimax_dev->net_dev);
275 break;
276 case __WIMAX_ST_INVALID:
277 default:
278 dev_err(dev, "SW BUG: wimax_dev %p is in unknown state %u\n",
279 wimax_dev, wimax_dev->state);
280 WARN_ON(1);
281 goto out;
282 }
283
284 /* Execute the actions of entry to the new state */
285 switch (new_state) {
286 case __WIMAX_ST_NULL:
287 dev_err(dev, "SW BUG: wimax_dev %p entering NULL state "
288 "from %u\n", wimax_dev, wimax_dev->state);
289 WARN_ON(1); /* Nobody can enter this state */
290 break;
291 case WIMAX_ST_DOWN:
292 break;
293 case __WIMAX_ST_QUIESCING:
294 break;
295 case WIMAX_ST_UNINITIALIZED:
296 break;
297 case WIMAX_ST_RADIO_OFF:
298 break;
299 case WIMAX_ST_READY:
300 break;
301 case WIMAX_ST_SCANNING:
302 break;
303 case WIMAX_ST_CONNECTING:
304 break;
305 case WIMAX_ST_CONNECTED:
306 netif_carrier_on(wimax_dev->net_dev);
307 netif_wake_queue(wimax_dev->net_dev);
308 break;
309 case __WIMAX_ST_INVALID:
310 default:
311 BUG();
312 }
313 __wimax_state_set(wimax_dev, new_state);
314 if (stch_skb)
315 wimax_gnl_re_state_change_send(wimax_dev, stch_skb, header);
316out:
317 d_fnend(3, dev, "(wimax_dev %p new_state %u [old %u]) = void\n",
318 wimax_dev, new_state, old_state);
319 return;
320}
321
322
323/**
324 * wimax_state_change - Set the current state of a WiMAX device
325 *
326 * @wimax_dev: WiMAX device descriptor (properly referenced)
327 * @new_state: New state to switch to
328 *
329 * This implements the state changes for the wimax devices. It will
330 *
331 * - verify that the state transition is legal (for now it'll just
332 * print a warning if not) according to the table in
333 * linux/wimax.h's documentation for 'enum wimax_st'.
334 *
335 * - perform the actions needed for leaving the current state and
336 * whichever are needed for entering the new state.
337 *
338 * - issue a report to user space indicating the new state (and an
339 * optional payload with information about the new state).
340 *
341 * NOTE: @wimax_dev must be locked
342 */
343void wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
344{
345 mutex_lock(&wimax_dev->mutex);
346 __wimax_state_change(wimax_dev, new_state);
347 mutex_unlock(&wimax_dev->mutex);
348 return;
349}
350EXPORT_SYMBOL_GPL(wimax_state_change);
351
352
353/**
354 * wimax_state_get() - Return the current state of a WiMAX device
355 *
356 * @wimax_dev: WiMAX device descriptor
357 *
358 * Returns: Current state of the device according to its driver.
359 */
360enum wimax_st wimax_state_get(struct wimax_dev *wimax_dev)
361{
362 enum wimax_st state;
363 mutex_lock(&wimax_dev->mutex);
364 state = wimax_dev->state;
365 mutex_unlock(&wimax_dev->mutex);
366 return state;
367}
368EXPORT_SYMBOL_GPL(wimax_state_get);
369
370
371/**
372 * wimax_dev_init - initialize a newly allocated instance
373 *
374 * @wimax_dev: WiMAX device descriptor to initialize.
375 *
376 * Initializes fields of a freshly allocated @wimax_dev instance. This
377 * function assumes that after allocation, the memory occupied by
378 * @wimax_dev was zeroed.
379 */
380void wimax_dev_init(struct wimax_dev *wimax_dev)
381{
382 INIT_LIST_HEAD(&wimax_dev->id_table_node);
383 __wimax_state_set(wimax_dev, WIMAX_ST_UNINITIALIZED);
384 mutex_init(&wimax_dev->mutex);
385 mutex_init(&wimax_dev->mutex_reset);
386}
387EXPORT_SYMBOL_GPL(wimax_dev_init);
388
389/*
390 * This extern is declared here because it's easier to keep track --
391 * both declarations are a list of the same
392 */
393extern struct genl_ops
394 wimax_gnl_msg_from_user,
395 wimax_gnl_reset,
396 wimax_gnl_rfkill;
397
398static
399struct genl_ops *wimax_gnl_ops[] = {
400 &wimax_gnl_msg_from_user,
401 &wimax_gnl_reset,
402 &wimax_gnl_rfkill,
403};
404
405
406static
407size_t wimax_addr_scnprint(char *addr_str, size_t addr_str_size,
408 unsigned char *addr, size_t addr_len)
409{
410 unsigned cnt, total;
411 for (total = cnt = 0; cnt < addr_len; cnt++)
412 total += scnprintf(addr_str + total, addr_str_size - total,
413 "%02x%c", addr[cnt],
414 cnt == addr_len - 1 ? '\0' : ':');
415 return total;
416}
417
418
419/**
420 * wimax_dev_add - Register a new WiMAX device
421 *
422 * @wimax_dev: WiMAX device descriptor (as embedded in your @net_dev's
423 * priv data). You must have called wimax_dev_init() on it before.
424 *
425 * @net_dev: net device the @wimax_dev is associated with. The
426 * function expects SET_NETDEV_DEV() and register_netdev() were
427 * already called on it.
428 *
429 * Registers the new WiMAX device, sets up the user-kernel control
430 * interface (generic netlink) and common WiMAX infrastructure.
431 *
432 * Note that the parts that will allow interaction with user space are
433 * setup at the very end, when the rest is in place, as once that
434 * happens, the driver might get user space control requests via
435 * netlink or from debugfs that might translate into calls into
436 * wimax_dev->op_*().
437 */
438int wimax_dev_add(struct wimax_dev *wimax_dev, struct net_device *net_dev)
439{
440 int result;
441 struct device *dev = net_dev->dev.parent;
442 char addr_str[32];
443
444 d_fnstart(3, dev, "(wimax_dev %p net_dev %p)\n", wimax_dev, net_dev);
445
446 /* Do the RFKILL setup before locking, as RFKILL will call
447 * into our functions. */
448 wimax_dev->net_dev = net_dev;
449 result = wimax_rfkill_add(wimax_dev);
450 if (result < 0)
451 goto error_rfkill_add;
452
453 /* Set up user-space interaction */
454 mutex_lock(&wimax_dev->mutex);
455 wimax_id_table_add(wimax_dev);
456 result = wimax_debugfs_add(wimax_dev);
457 if (result < 0) {
458 dev_err(dev, "cannot initialize debugfs: %d\n",
459 result);
460 goto error_debugfs_add;
461 }
462
463 __wimax_state_set(wimax_dev, WIMAX_ST_DOWN);
464 mutex_unlock(&wimax_dev->mutex);
465
466 wimax_addr_scnprint(addr_str, sizeof(addr_str),
467 net_dev->dev_addr, net_dev->addr_len);
468 dev_err(dev, "WiMAX interface %s (%s) ready\n",
469 net_dev->name, addr_str);
470 d_fnend(3, dev, "(wimax_dev %p net_dev %p) = 0\n", wimax_dev, net_dev);
471 return 0;
472
473error_debugfs_add:
474 wimax_id_table_rm(wimax_dev);
475 mutex_unlock(&wimax_dev->mutex);
476 wimax_rfkill_rm(wimax_dev);
477error_rfkill_add:
478 d_fnend(3, dev, "(wimax_dev %p net_dev %p) = %d\n",
479 wimax_dev, net_dev, result);
480 return result;
481}
482EXPORT_SYMBOL_GPL(wimax_dev_add);
483
484
485/**
486 * wimax_dev_rm - Unregister an existing WiMAX device
487 *
488 * @wimax_dev: WiMAX device descriptor
489 *
490 * Unregisters a WiMAX device previously registered for use with
491 * wimax_add_rm().
492 *
493 * IMPORTANT! Must call before calling unregister_netdev().
494 *
495 * After this function returns, you will not get any more user space
496 * control requests (via netlink or debugfs) and thus to wimax_dev->ops.
497 *
498 * Reentrancy control is ensured by setting the state to
499 * %__WIMAX_ST_QUIESCING. rfkill operations coming through
500 * wimax_*rfkill*() will be stopped by the quiescing state; ops coming
501 * from the rfkill subsystem will be stopped by the support being
502 * removed by wimax_rfkill_rm().
503 */
504void wimax_dev_rm(struct wimax_dev *wimax_dev)
505{
506 d_fnstart(3, NULL, "(wimax_dev %p)\n", wimax_dev);
507
508 mutex_lock(&wimax_dev->mutex);
509 __wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
510 wimax_debugfs_rm(wimax_dev);
511 wimax_id_table_rm(wimax_dev);
512 __wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
513 mutex_unlock(&wimax_dev->mutex);
514 wimax_rfkill_rm(wimax_dev);
515 d_fnend(3, NULL, "(wimax_dev %p) = void\n", wimax_dev);
516}
517EXPORT_SYMBOL_GPL(wimax_dev_rm);
518
519struct genl_family wimax_gnl_family = {
520 .id = GENL_ID_GENERATE,
521 .name = "WiMAX",
522 .version = WIMAX_GNL_VERSION,
523 .hdrsize = 0,
524 .maxattr = WIMAX_GNL_ATTR_MAX,
525};
526
527struct genl_multicast_group wimax_gnl_mcg = {
528 .name = "msg",
529};
530
531
532
533/* Shutdown the wimax stack */
534static
535int __init wimax_subsys_init(void)
536{
537 int result, cnt;
538
539 d_fnstart(4, NULL, "()\n");
540 snprintf(wimax_gnl_family.name, sizeof(wimax_gnl_family.name),
541 "WiMAX");
542 result = genl_register_family(&wimax_gnl_family);
543 if (unlikely(result < 0)) {
544 printk(KERN_ERR "cannot register generic netlink family: %d\n",
545 result);
546 goto error_register_family;
547 }
548
549 for (cnt = 0; cnt < ARRAY_SIZE(wimax_gnl_ops); cnt++) {
550 result = genl_register_ops(&wimax_gnl_family,
551 wimax_gnl_ops[cnt]);
552 d_printf(4, NULL, "registering generic netlink op code "
553 "%u: %d\n", wimax_gnl_ops[cnt]->cmd, result);
554 if (unlikely(result < 0)) {
555 printk(KERN_ERR "cannot register generic netlink op "
556 "code %u: %d\n",
557 wimax_gnl_ops[cnt]->cmd, result);
558 goto error_register_ops;
559 }
560 }
561
562 result = genl_register_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
563 if (result < 0)
564 goto error_mc_group;
565 d_fnend(4, NULL, "() = 0\n");
566 return 0;
567
568error_mc_group:
569error_register_ops:
570 for (cnt--; cnt >= 0; cnt--)
571 genl_unregister_ops(&wimax_gnl_family,
572 wimax_gnl_ops[cnt]);
573 genl_unregister_family(&wimax_gnl_family);
574error_register_family:
575 d_fnend(4, NULL, "() = %d\n", result);
576 return result;
577
578}
579module_init(wimax_subsys_init);
580
581
582/* Shutdown the wimax stack */
583static
584void __exit wimax_subsys_exit(void)
585{
586 int cnt;
587 wimax_id_table_release();
588 genl_unregister_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
589 for (cnt = ARRAY_SIZE(wimax_gnl_ops) - 1; cnt >= 0; cnt--)
590 genl_unregister_ops(&wimax_gnl_family,
591 wimax_gnl_ops[cnt]);
592 genl_unregister_family(&wimax_gnl_family);
593}
594module_exit(wimax_subsys_exit);
595
596MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
597MODULE_DESCRIPTION("Linux WiMAX stack");
598MODULE_LICENSE("GPL");
599