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