1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright 2017 Ben Whitten <ben.whitten@gmail.com>
3 // Copyright 2007 Oliver Jowett <oliver@opencloud.com>
4 //
5 // LED Kernel Netdev Trigger
6 //
7 // Toggles the LED to reflect the link and traffic state of a named net device
8 //
9 // Derived from ledtrig-timer.c which is:
10 // Copyright 2005-2006 Openedhand Ltd.
11 // Author: Richard Purdie <rpurdie@openedhand.com>
12
13 #include <linux/atomic.h>
14 #include <linux/ctype.h>
15 #include <linux/device.h>
16 #include <linux/ethtool.h>
17 #include <linux/init.h>
18 #include <linux/jiffies.h>
19 #include <linux/kernel.h>
20 #include <linux/leds.h>
21 #include <linux/list.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/mutex.h>
25 #include <linux/rtnetlink.h>
26 #include <linux/timer.h>
27 #include "../leds.h"
28
29 #define NETDEV_LED_DEFAULT_INTERVAL 50
30
31 /*
32 * Configurable sysfs attributes:
33 *
34 * device_name - network device name to monitor
35 * interval - duration of LED blink, in milliseconds
36 * link - LED's normal state reflects whether the link is up
37 * (has carrier) or not
38 * tx - LED blinks on transmitted data
39 * rx - LED blinks on receive data
40 *
41 */
42
43 struct led_netdev_data {
44 struct mutex lock;
45
46 struct delayed_work work;
47 struct notifier_block notifier;
48
49 struct led_classdev *led_cdev;
50 struct net_device *net_dev;
51
52 char device_name[IFNAMSIZ];
53 atomic_t interval;
54 unsigned int last_activity;
55
56 unsigned long mode;
57 unsigned long blink_delay;
58 int link_speed;
59 u8 duplex;
60
61 bool carrier_link_up;
62 bool hw_control;
63 };
64
set_baseline_state(struct led_netdev_data * trigger_data)65 static void set_baseline_state(struct led_netdev_data *trigger_data)
66 {
67 int current_brightness;
68 struct led_classdev *led_cdev = trigger_data->led_cdev;
69
70 /* Already validated, hw control is possible with the requested mode */
71 if (trigger_data->hw_control) {
72 led_cdev->hw_control_set(led_cdev, trigger_data->mode);
73 if (led_cdev->blink_set) {
74 led_cdev->blink_set(led_cdev, &trigger_data->blink_delay,
75 &trigger_data->blink_delay);
76 }
77
78 return;
79 }
80
81 current_brightness = led_cdev->brightness;
82 if (current_brightness)
83 led_cdev->blink_brightness = current_brightness;
84 if (!led_cdev->blink_brightness)
85 led_cdev->blink_brightness = led_cdev->max_brightness;
86
87 if (!trigger_data->carrier_link_up) {
88 led_set_brightness(led_cdev, LED_OFF);
89 } else {
90 bool blink_on = false;
91
92 if (test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode))
93 blink_on = true;
94
95 if (test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) &&
96 trigger_data->link_speed == SPEED_10)
97 blink_on = true;
98
99 if (test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) &&
100 trigger_data->link_speed == SPEED_100)
101 blink_on = true;
102
103 if (test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) &&
104 trigger_data->link_speed == SPEED_1000)
105 blink_on = true;
106
107 if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) &&
108 trigger_data->duplex == DUPLEX_HALF)
109 blink_on = true;
110
111 if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) &&
112 trigger_data->duplex == DUPLEX_FULL)
113 blink_on = true;
114
115 if (blink_on)
116 led_set_brightness(led_cdev,
117 led_cdev->blink_brightness);
118 else
119 led_set_brightness(led_cdev, LED_OFF);
120
121 /* If we are looking for RX/TX start periodically
122 * checking stats
123 */
124 if (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ||
125 test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
126 schedule_delayed_work(&trigger_data->work, 0);
127 }
128 }
129
supports_hw_control(struct led_classdev * led_cdev)130 static bool supports_hw_control(struct led_classdev *led_cdev)
131 {
132 if (!led_cdev->hw_control_get || !led_cdev->hw_control_set ||
133 !led_cdev->hw_control_is_supported)
134 return false;
135
136 return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name);
137 }
138
139 /*
140 * Validate the configured netdev is the same as the one associated with
141 * the LED driver in hw control.
142 */
validate_net_dev(struct led_classdev * led_cdev,struct net_device * net_dev)143 static bool validate_net_dev(struct led_classdev *led_cdev,
144 struct net_device *net_dev)
145 {
146 struct device *dev = led_cdev->hw_control_get_device(led_cdev);
147 struct net_device *ndev;
148
149 if (!dev)
150 return false;
151
152 ndev = to_net_dev(dev);
153
154 return ndev == net_dev;
155 }
156
can_hw_control(struct led_netdev_data * trigger_data)157 static bool can_hw_control(struct led_netdev_data *trigger_data)
158 {
159 unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL);
160 unsigned int interval = atomic_read(&trigger_data->interval);
161 struct led_classdev *led_cdev = trigger_data->led_cdev;
162 int ret;
163
164 if (!supports_hw_control(led_cdev))
165 return false;
166
167 /*
168 * Interval must be set to the default
169 * value. Any different value is rejected if in hw
170 * control.
171 */
172 if (interval != default_interval)
173 return false;
174
175 /*
176 * net_dev must be set with hw control, otherwise no
177 * blinking can be happening and there is nothing to
178 * offloaded. Additionally, for hw control to be
179 * valid, the configured netdev must be the same as
180 * netdev associated to the LED.
181 */
182 if (!validate_net_dev(led_cdev, trigger_data->net_dev))
183 return false;
184
185 /* Check if the requested mode is supported */
186 ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode);
187 /* Fall back to software blinking if not supported */
188 if (ret == -EOPNOTSUPP)
189 return false;
190 if (ret) {
191 dev_warn(led_cdev->dev,
192 "Current mode check failed with error %d\n", ret);
193 return false;
194 }
195
196 return true;
197 }
198
get_device_state(struct led_netdev_data * trigger_data)199 static void get_device_state(struct led_netdev_data *trigger_data)
200 {
201 struct ethtool_link_ksettings cmd;
202
203 trigger_data->carrier_link_up = netif_carrier_ok(trigger_data->net_dev);
204 if (!trigger_data->carrier_link_up)
205 return;
206
207 if (!__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd)) {
208 trigger_data->link_speed = cmd.base.speed;
209 trigger_data->duplex = cmd.base.duplex;
210 }
211 }
212
device_name_show(struct device * dev,struct device_attribute * attr,char * buf)213 static ssize_t device_name_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
215 {
216 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
217 ssize_t len;
218
219 mutex_lock(&trigger_data->lock);
220 len = sprintf(buf, "%s\n", trigger_data->device_name);
221 mutex_unlock(&trigger_data->lock);
222
223 return len;
224 }
225
set_device_name(struct led_netdev_data * trigger_data,const char * name,size_t size)226 static int set_device_name(struct led_netdev_data *trigger_data,
227 const char *name, size_t size)
228 {
229 if (size >= IFNAMSIZ)
230 return -EINVAL;
231
232 cancel_delayed_work_sync(&trigger_data->work);
233
234 /*
235 * Take RTNL lock before trigger_data lock to prevent potential
236 * deadlock with netdev notifier registration.
237 */
238 rtnl_lock();
239 mutex_lock(&trigger_data->lock);
240
241 if (trigger_data->net_dev) {
242 dev_put(trigger_data->net_dev);
243 trigger_data->net_dev = NULL;
244 }
245
246 memcpy(trigger_data->device_name, name, size);
247 trigger_data->device_name[size] = 0;
248 if (size > 0 && trigger_data->device_name[size - 1] == '\n')
249 trigger_data->device_name[size - 1] = 0;
250
251 if (trigger_data->device_name[0] != 0)
252 trigger_data->net_dev =
253 dev_get_by_name(&init_net, trigger_data->device_name);
254
255 trigger_data->carrier_link_up = false;
256 trigger_data->link_speed = SPEED_UNKNOWN;
257 trigger_data->duplex = DUPLEX_UNKNOWN;
258 if (trigger_data->net_dev)
259 get_device_state(trigger_data);
260
261 trigger_data->last_activity = 0;
262
263 set_baseline_state(trigger_data);
264 mutex_unlock(&trigger_data->lock);
265 rtnl_unlock();
266
267 return 0;
268 }
269
device_name_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)270 static ssize_t device_name_store(struct device *dev,
271 struct device_attribute *attr, const char *buf,
272 size_t size)
273 {
274 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
275 int ret;
276
277 ret = set_device_name(trigger_data, buf, size);
278
279 if (ret < 0)
280 return ret;
281 return size;
282 }
283
284 static DEVICE_ATTR_RW(device_name);
285
netdev_led_attr_show(struct device * dev,char * buf,enum led_trigger_netdev_modes attr)286 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
287 enum led_trigger_netdev_modes attr)
288 {
289 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
290 int bit;
291
292 switch (attr) {
293 case TRIGGER_NETDEV_LINK:
294 case TRIGGER_NETDEV_LINK_10:
295 case TRIGGER_NETDEV_LINK_100:
296 case TRIGGER_NETDEV_LINK_1000:
297 case TRIGGER_NETDEV_HALF_DUPLEX:
298 case TRIGGER_NETDEV_FULL_DUPLEX:
299 case TRIGGER_NETDEV_TX:
300 case TRIGGER_NETDEV_RX:
301 bit = attr;
302 break;
303 default:
304 return -EINVAL;
305 }
306
307 return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
308 }
309
netdev_led_attr_store(struct device * dev,const char * buf,size_t size,enum led_trigger_netdev_modes attr)310 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
311 size_t size, enum led_trigger_netdev_modes attr)
312 {
313 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
314 unsigned long state, mode = trigger_data->mode;
315 int ret;
316 int bit;
317
318 ret = kstrtoul(buf, 0, &state);
319 if (ret)
320 return ret;
321
322 switch (attr) {
323 case TRIGGER_NETDEV_LINK:
324 case TRIGGER_NETDEV_LINK_10:
325 case TRIGGER_NETDEV_LINK_100:
326 case TRIGGER_NETDEV_LINK_1000:
327 case TRIGGER_NETDEV_HALF_DUPLEX:
328 case TRIGGER_NETDEV_FULL_DUPLEX:
329 case TRIGGER_NETDEV_TX:
330 case TRIGGER_NETDEV_RX:
331 bit = attr;
332 break;
333 default:
334 return -EINVAL;
335 }
336
337 if (state)
338 set_bit(bit, &mode);
339 else
340 clear_bit(bit, &mode);
341
342 if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
343 (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
344 test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
345 test_bit(TRIGGER_NETDEV_LINK_1000, &mode)))
346 return -EINVAL;
347
348 cancel_delayed_work_sync(&trigger_data->work);
349
350 trigger_data->mode = mode;
351 trigger_data->hw_control = can_hw_control(trigger_data);
352
353 set_baseline_state(trigger_data);
354
355 return size;
356 }
357
358 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
359 static ssize_t trigger_name##_show(struct device *dev, \
360 struct device_attribute *attr, char *buf) \
361 { \
362 return netdev_led_attr_show(dev, buf, trigger); \
363 } \
364 static ssize_t trigger_name##_store(struct device *dev, \
365 struct device_attribute *attr, const char *buf, size_t size) \
366 { \
367 return netdev_led_attr_store(dev, buf, size, trigger); \
368 } \
369 static DEVICE_ATTR_RW(trigger_name)
370
371 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
372 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
373 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
374 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
375 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
376 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
377 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
378 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
379
interval_show(struct device * dev,struct device_attribute * attr,char * buf)380 static ssize_t interval_show(struct device *dev,
381 struct device_attribute *attr, char *buf)
382 {
383 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
384
385 return sprintf(buf, "%u\n",
386 jiffies_to_msecs(atomic_read(&trigger_data->interval)));
387 }
388
interval_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)389 static ssize_t interval_store(struct device *dev,
390 struct device_attribute *attr, const char *buf,
391 size_t size)
392 {
393 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
394 struct led_classdev *led_cdev = trigger_data->led_cdev;
395 unsigned long value;
396 int ret;
397
398 if (trigger_data->hw_control && !led_cdev->blink_set)
399 return -EINVAL;
400
401 ret = kstrtoul(buf, 0, &value);
402 if (ret)
403 return ret;
404
405 /* impose some basic bounds on the timer interval */
406 if (value >= 5 && value <= 10000) {
407 if (trigger_data->hw_control) {
408 trigger_data->blink_delay = value;
409 } else {
410 cancel_delayed_work_sync(&trigger_data->work);
411
412 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
413 }
414 set_baseline_state(trigger_data); /* resets timer */
415 }
416
417 return size;
418 }
419
420 static DEVICE_ATTR_RW(interval);
421
offloaded_show(struct device * dev,struct device_attribute * attr,char * buf)422 static ssize_t offloaded_show(struct device *dev,
423 struct device_attribute *attr, char *buf)
424 {
425 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
426
427 return sprintf(buf, "%d\n", trigger_data->hw_control);
428 }
429
430 static DEVICE_ATTR_RO(offloaded);
431
432 static struct attribute *netdev_trig_attrs[] = {
433 &dev_attr_device_name.attr,
434 &dev_attr_link.attr,
435 &dev_attr_link_10.attr,
436 &dev_attr_link_100.attr,
437 &dev_attr_link_1000.attr,
438 &dev_attr_full_duplex.attr,
439 &dev_attr_half_duplex.attr,
440 &dev_attr_rx.attr,
441 &dev_attr_tx.attr,
442 &dev_attr_interval.attr,
443 &dev_attr_offloaded.attr,
444 NULL
445 };
446 ATTRIBUTE_GROUPS(netdev_trig);
447
netdev_trig_notify(struct notifier_block * nb,unsigned long evt,void * dv)448 static int netdev_trig_notify(struct notifier_block *nb,
449 unsigned long evt, void *dv)
450 {
451 struct net_device *dev =
452 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
453 struct led_netdev_data *trigger_data =
454 container_of(nb, struct led_netdev_data, notifier);
455
456 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
457 && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
458 && evt != NETDEV_CHANGENAME)
459 return NOTIFY_DONE;
460
461 if (!(dev == trigger_data->net_dev ||
462 (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
463 (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
464 return NOTIFY_DONE;
465
466 cancel_delayed_work_sync(&trigger_data->work);
467
468 mutex_lock(&trigger_data->lock);
469
470 trigger_data->carrier_link_up = false;
471 trigger_data->link_speed = SPEED_UNKNOWN;
472 trigger_data->duplex = DUPLEX_UNKNOWN;
473 switch (evt) {
474 case NETDEV_CHANGENAME:
475 case NETDEV_REGISTER:
476 dev_put(trigger_data->net_dev);
477 dev_hold(dev);
478 trigger_data->net_dev = dev;
479 if (evt == NETDEV_CHANGENAME)
480 get_device_state(trigger_data);
481 break;
482 case NETDEV_UNREGISTER:
483 dev_put(trigger_data->net_dev);
484 trigger_data->net_dev = NULL;
485 break;
486 case NETDEV_UP:
487 case NETDEV_CHANGE:
488 get_device_state(trigger_data);
489 break;
490 }
491
492 set_baseline_state(trigger_data);
493
494 mutex_unlock(&trigger_data->lock);
495
496 return NOTIFY_DONE;
497 }
498
499 /* here's the real work! */
netdev_trig_work(struct work_struct * work)500 static void netdev_trig_work(struct work_struct *work)
501 {
502 struct led_netdev_data *trigger_data =
503 container_of(work, struct led_netdev_data, work.work);
504 struct rtnl_link_stats64 *dev_stats;
505 unsigned int new_activity;
506 struct rtnl_link_stats64 temp;
507 unsigned long interval;
508 int invert;
509
510 /* If we dont have a device, insure we are off */
511 if (!trigger_data->net_dev) {
512 led_set_brightness(trigger_data->led_cdev, LED_OFF);
513 return;
514 }
515
516 /* If we are not looking for RX/TX then return */
517 if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
518 !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
519 return;
520
521 dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
522 new_activity =
523 (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
524 dev_stats->tx_packets : 0) +
525 (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
526 dev_stats->rx_packets : 0);
527
528 if (trigger_data->last_activity != new_activity) {
529 led_stop_software_blink(trigger_data->led_cdev);
530
531 invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
532 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
533 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
534 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
535 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
536 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
537 interval = jiffies_to_msecs(
538 atomic_read(&trigger_data->interval));
539 /* base state is ON (link present) */
540 led_blink_set_oneshot(trigger_data->led_cdev,
541 &interval,
542 &interval,
543 invert);
544 trigger_data->last_activity = new_activity;
545 }
546
547 schedule_delayed_work(&trigger_data->work,
548 (atomic_read(&trigger_data->interval)*2));
549 }
550
netdev_trig_activate(struct led_classdev * led_cdev)551 static int netdev_trig_activate(struct led_classdev *led_cdev)
552 {
553 struct led_netdev_data *trigger_data;
554 unsigned long mode = 0;
555 struct device *dev;
556 int rc;
557
558 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
559 if (!trigger_data)
560 return -ENOMEM;
561
562 mutex_init(&trigger_data->lock);
563
564 trigger_data->notifier.notifier_call = netdev_trig_notify;
565 trigger_data->notifier.priority = 10;
566
567 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
568
569 trigger_data->led_cdev = led_cdev;
570 trigger_data->net_dev = NULL;
571 trigger_data->device_name[0] = 0;
572
573 trigger_data->mode = 0;
574 atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
575 trigger_data->last_activity = 0;
576
577 /* Check if hw control is active by default on the LED.
578 * Init already enabled mode in hw control.
579 */
580 if (supports_hw_control(led_cdev)) {
581 dev = led_cdev->hw_control_get_device(led_cdev);
582 if (dev) {
583 const char *name = dev_name(dev);
584
585 set_device_name(trigger_data, name, strlen(name));
586 trigger_data->hw_control = true;
587
588 rc = led_cdev->hw_control_get(led_cdev, &mode);
589 if (!rc)
590 trigger_data->mode = mode;
591 }
592 }
593
594 led_set_trigger_data(led_cdev, trigger_data);
595
596 rc = register_netdevice_notifier(&trigger_data->notifier);
597 if (rc)
598 kfree(trigger_data);
599
600 return rc;
601 }
602
netdev_trig_deactivate(struct led_classdev * led_cdev)603 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
604 {
605 struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
606
607 unregister_netdevice_notifier(&trigger_data->notifier);
608
609 cancel_delayed_work_sync(&trigger_data->work);
610
611 led_set_brightness(led_cdev, LED_OFF);
612
613 dev_put(trigger_data->net_dev);
614
615 kfree(trigger_data);
616 }
617
618 static struct led_trigger netdev_led_trigger = {
619 .name = "netdev",
620 .activate = netdev_trig_activate,
621 .deactivate = netdev_trig_deactivate,
622 .groups = netdev_trig_groups,
623 };
624
625 module_led_trigger(netdev_led_trigger);
626
627 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
628 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
629 MODULE_DESCRIPTION("Netdev LED trigger");
630 MODULE_LICENSE("GPL v2");
631