Loading...
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 * Note: If the user selects a mode that is not supported by hw, default
42 * behavior is to fall back to software control of the LED. However not every
43 * hw supports software control. LED callbacks brightness_set() and
44 * brightness_set_blocking() are NULL in this case. hw_control_is_supported()
45 * should use available means supported by hw to inform the user that selected
46 * mode isn't supported by hw. This could be switching off the LED or any
47 * hw blink mode. If software control fallback isn't possible, we return
48 * -EOPNOTSUPP to the user, but still store the selected mode. This is needed
49 * in case an intermediate unsupported mode is necessary to switch from one
50 * supported mode to another.
51 */
52
53struct led_netdev_data {
54 struct mutex lock;
55
56 struct delayed_work work;
57 struct notifier_block notifier;
58
59 struct led_classdev *led_cdev;
60 struct net_device *net_dev;
61
62 char device_name[IFNAMSIZ];
63 atomic_t interval;
64 unsigned int last_activity;
65
66 unsigned long mode;
67 int link_speed;
68 u8 duplex;
69
70 bool carrier_link_up;
71 bool hw_control;
72};
73
74static void set_baseline_state(struct led_netdev_data *trigger_data)
75{
76 int current_brightness;
77 struct led_classdev *led_cdev = trigger_data->led_cdev;
78
79 /* Already validated, hw control is possible with the requested mode */
80 if (trigger_data->hw_control) {
81 led_cdev->hw_control_set(led_cdev, trigger_data->mode);
82
83 return;
84 }
85
86 current_brightness = led_cdev->brightness;
87 if (current_brightness)
88 led_cdev->blink_brightness = current_brightness;
89 if (!led_cdev->blink_brightness)
90 led_cdev->blink_brightness = led_cdev->max_brightness;
91
92 if (!trigger_data->carrier_link_up) {
93 led_set_brightness(led_cdev, LED_OFF);
94 } else {
95 bool blink_on = false;
96
97 if (test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode))
98 blink_on = true;
99
100 if (test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) &&
101 trigger_data->link_speed == SPEED_10)
102 blink_on = true;
103
104 if (test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) &&
105 trigger_data->link_speed == SPEED_100)
106 blink_on = true;
107
108 if (test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) &&
109 trigger_data->link_speed == SPEED_1000)
110 blink_on = true;
111
112 if (test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) &&
113 trigger_data->link_speed == SPEED_2500)
114 blink_on = true;
115
116 if (test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) &&
117 trigger_data->link_speed == SPEED_5000)
118 blink_on = true;
119
120 if (test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) &&
121 trigger_data->link_speed == SPEED_10000)
122 blink_on = true;
123
124 if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) &&
125 trigger_data->duplex == DUPLEX_HALF)
126 blink_on = true;
127
128 if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) &&
129 trigger_data->duplex == DUPLEX_FULL)
130 blink_on = true;
131
132 if (blink_on)
133 led_set_brightness(led_cdev,
134 led_cdev->blink_brightness);
135 else
136 led_set_brightness(led_cdev, LED_OFF);
137
138 /* If we are looking for RX/TX start periodically
139 * checking stats
140 */
141 if (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ||
142 test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
143 schedule_delayed_work(&trigger_data->work, 0);
144 }
145}
146
147static bool supports_hw_control(struct led_classdev *led_cdev)
148{
149 if (!led_cdev->hw_control_get || !led_cdev->hw_control_set ||
150 !led_cdev->hw_control_is_supported)
151 return false;
152
153 return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name);
154}
155
156/*
157 * Validate the configured netdev is the same as the one associated with
158 * the LED driver in hw control.
159 */
160static bool validate_net_dev(struct led_classdev *led_cdev,
161 struct net_device *net_dev)
162{
163 struct device *dev = led_cdev->hw_control_get_device(led_cdev);
164 struct net_device *ndev;
165
166 if (!dev)
167 return false;
168
169 ndev = to_net_dev(dev);
170
171 return ndev == net_dev;
172}
173
174static bool can_hw_control(struct led_netdev_data *trigger_data)
175{
176 unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL);
177 unsigned int interval = atomic_read(&trigger_data->interval);
178 struct led_classdev *led_cdev = trigger_data->led_cdev;
179 int ret;
180
181 if (!supports_hw_control(led_cdev))
182 return false;
183
184 /*
185 * Interval must be set to the default
186 * value. Any different value is rejected if in hw
187 * control.
188 */
189 if (interval != default_interval)
190 return false;
191
192 /*
193 * net_dev must be set with hw control, otherwise no
194 * blinking can be happening and there is nothing to
195 * offloaded. Additionally, for hw control to be
196 * valid, the configured netdev must be the same as
197 * netdev associated to the LED.
198 */
199 if (!validate_net_dev(led_cdev, trigger_data->net_dev))
200 return false;
201
202 /* Check if the requested mode is supported */
203 ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode);
204 /* Fall back to software blinking if not supported */
205 if (ret == -EOPNOTSUPP)
206 return false;
207 if (ret) {
208 dev_warn(led_cdev->dev,
209 "Current mode check failed with error %d\n", ret);
210 return false;
211 }
212
213 return true;
214}
215
216static void get_device_state(struct led_netdev_data *trigger_data)
217{
218 struct ethtool_link_ksettings cmd;
219
220 trigger_data->carrier_link_up = netif_carrier_ok(trigger_data->net_dev);
221 if (!trigger_data->carrier_link_up)
222 return;
223
224 if (!__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd)) {
225 trigger_data->link_speed = cmd.base.speed;
226 trigger_data->duplex = cmd.base.duplex;
227 }
228}
229
230static ssize_t device_name_show(struct device *dev,
231 struct device_attribute *attr, char *buf)
232{
233 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
234 ssize_t len;
235
236 mutex_lock(&trigger_data->lock);
237 len = sprintf(buf, "%s\n", trigger_data->device_name);
238 mutex_unlock(&trigger_data->lock);
239
240 return len;
241}
242
243static int set_device_name(struct led_netdev_data *trigger_data,
244 const char *name, size_t size)
245{
246 if (size >= IFNAMSIZ)
247 return -EINVAL;
248
249 cancel_delayed_work_sync(&trigger_data->work);
250
251 /*
252 * Take RTNL lock before trigger_data lock to prevent potential
253 * deadlock with netdev notifier registration.
254 */
255 rtnl_lock();
256 mutex_lock(&trigger_data->lock);
257
258 if (trigger_data->net_dev) {
259 dev_put(trigger_data->net_dev);
260 trigger_data->net_dev = NULL;
261 }
262
263 memcpy(trigger_data->device_name, name, size);
264 trigger_data->device_name[size] = 0;
265 if (size > 0 && trigger_data->device_name[size - 1] == '\n')
266 trigger_data->device_name[size - 1] = 0;
267
268 if (trigger_data->device_name[0] != 0)
269 trigger_data->net_dev =
270 dev_get_by_name(&init_net, trigger_data->device_name);
271
272 trigger_data->carrier_link_up = false;
273 trigger_data->link_speed = SPEED_UNKNOWN;
274 trigger_data->duplex = DUPLEX_UNKNOWN;
275 if (trigger_data->net_dev)
276 get_device_state(trigger_data);
277
278 trigger_data->last_activity = 0;
279
280 set_baseline_state(trigger_data);
281 mutex_unlock(&trigger_data->lock);
282 rtnl_unlock();
283
284 return 0;
285}
286
287static ssize_t device_name_store(struct device *dev,
288 struct device_attribute *attr, const char *buf,
289 size_t size)
290{
291 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
292 int ret;
293
294 ret = set_device_name(trigger_data, buf, size);
295
296 if (ret < 0)
297 return ret;
298 return size;
299}
300
301static DEVICE_ATTR_RW(device_name);
302
303static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
304 enum led_trigger_netdev_modes attr)
305{
306 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
307 int bit;
308
309 switch (attr) {
310 case TRIGGER_NETDEV_LINK:
311 case TRIGGER_NETDEV_LINK_10:
312 case TRIGGER_NETDEV_LINK_100:
313 case TRIGGER_NETDEV_LINK_1000:
314 case TRIGGER_NETDEV_LINK_2500:
315 case TRIGGER_NETDEV_LINK_5000:
316 case TRIGGER_NETDEV_LINK_10000:
317 case TRIGGER_NETDEV_HALF_DUPLEX:
318 case TRIGGER_NETDEV_FULL_DUPLEX:
319 case TRIGGER_NETDEV_TX:
320 case TRIGGER_NETDEV_RX:
321 bit = attr;
322 break;
323 default:
324 return -EINVAL;
325 }
326
327 return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
328}
329
330static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
331 size_t size, enum led_trigger_netdev_modes attr)
332{
333 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
334 struct led_classdev *led_cdev = trigger_data->led_cdev;
335 unsigned long state, mode = trigger_data->mode;
336 int ret;
337 int bit;
338
339 ret = kstrtoul(buf, 0, &state);
340 if (ret)
341 return ret;
342
343 switch (attr) {
344 case TRIGGER_NETDEV_LINK:
345 case TRIGGER_NETDEV_LINK_10:
346 case TRIGGER_NETDEV_LINK_100:
347 case TRIGGER_NETDEV_LINK_1000:
348 case TRIGGER_NETDEV_LINK_2500:
349 case TRIGGER_NETDEV_LINK_5000:
350 case TRIGGER_NETDEV_LINK_10000:
351 case TRIGGER_NETDEV_HALF_DUPLEX:
352 case TRIGGER_NETDEV_FULL_DUPLEX:
353 case TRIGGER_NETDEV_TX:
354 case TRIGGER_NETDEV_RX:
355 bit = attr;
356 break;
357 default:
358 return -EINVAL;
359 }
360
361 if (state)
362 set_bit(bit, &mode);
363 else
364 clear_bit(bit, &mode);
365
366 if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
367 (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
368 test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
369 test_bit(TRIGGER_NETDEV_LINK_1000, &mode) ||
370 test_bit(TRIGGER_NETDEV_LINK_2500, &mode) ||
371 test_bit(TRIGGER_NETDEV_LINK_5000, &mode) ||
372 test_bit(TRIGGER_NETDEV_LINK_10000, &mode)))
373 return -EINVAL;
374
375 cancel_delayed_work_sync(&trigger_data->work);
376
377 trigger_data->mode = mode;
378 trigger_data->hw_control = can_hw_control(trigger_data);
379
380 if (!led_cdev->brightness_set && !led_cdev->brightness_set_blocking &&
381 !trigger_data->hw_control)
382 return -EOPNOTSUPP;
383
384 set_baseline_state(trigger_data);
385
386 return size;
387}
388
389#define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
390 static ssize_t trigger_name##_show(struct device *dev, \
391 struct device_attribute *attr, char *buf) \
392 { \
393 return netdev_led_attr_show(dev, buf, trigger); \
394 } \
395 static ssize_t trigger_name##_store(struct device *dev, \
396 struct device_attribute *attr, const char *buf, size_t size) \
397 { \
398 return netdev_led_attr_store(dev, buf, size, trigger); \
399 } \
400 static DEVICE_ATTR_RW(trigger_name)
401
402DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
403DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
404DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
405DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
406DEFINE_NETDEV_TRIGGER(link_2500, TRIGGER_NETDEV_LINK_2500);
407DEFINE_NETDEV_TRIGGER(link_5000, TRIGGER_NETDEV_LINK_5000);
408DEFINE_NETDEV_TRIGGER(link_10000, TRIGGER_NETDEV_LINK_10000);
409DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
410DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
411DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
412DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
413
414static ssize_t interval_show(struct device *dev,
415 struct device_attribute *attr, char *buf)
416{
417 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
418
419 return sprintf(buf, "%u\n",
420 jiffies_to_msecs(atomic_read(&trigger_data->interval)));
421}
422
423static ssize_t interval_store(struct device *dev,
424 struct device_attribute *attr, const char *buf,
425 size_t size)
426{
427 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
428 unsigned long value;
429 int ret;
430
431 if (trigger_data->hw_control)
432 return -EINVAL;
433
434 ret = kstrtoul(buf, 0, &value);
435 if (ret)
436 return ret;
437
438 /* impose some basic bounds on the timer interval */
439 if (value >= 5 && value <= 10000) {
440 cancel_delayed_work_sync(&trigger_data->work);
441
442 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
443 set_baseline_state(trigger_data); /* resets timer */
444 }
445
446 return size;
447}
448
449static DEVICE_ATTR_RW(interval);
450
451static ssize_t offloaded_show(struct device *dev,
452 struct device_attribute *attr, char *buf)
453{
454 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
455
456 return sprintf(buf, "%d\n", trigger_data->hw_control);
457}
458
459static DEVICE_ATTR_RO(offloaded);
460
461static struct attribute *netdev_trig_attrs[] = {
462 &dev_attr_device_name.attr,
463 &dev_attr_link.attr,
464 &dev_attr_link_10.attr,
465 &dev_attr_link_100.attr,
466 &dev_attr_link_1000.attr,
467 &dev_attr_link_2500.attr,
468 &dev_attr_link_5000.attr,
469 &dev_attr_link_10000.attr,
470 &dev_attr_full_duplex.attr,
471 &dev_attr_half_duplex.attr,
472 &dev_attr_rx.attr,
473 &dev_attr_tx.attr,
474 &dev_attr_interval.attr,
475 &dev_attr_offloaded.attr,
476 NULL
477};
478ATTRIBUTE_GROUPS(netdev_trig);
479
480static int netdev_trig_notify(struct notifier_block *nb,
481 unsigned long evt, void *dv)
482{
483 struct net_device *dev =
484 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
485 struct led_netdev_data *trigger_data =
486 container_of(nb, struct led_netdev_data, notifier);
487
488 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
489 && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
490 && evt != NETDEV_CHANGENAME)
491 return NOTIFY_DONE;
492
493 if (!(dev == trigger_data->net_dev ||
494 (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
495 (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
496 return NOTIFY_DONE;
497
498 cancel_delayed_work_sync(&trigger_data->work);
499
500 mutex_lock(&trigger_data->lock);
501
502 trigger_data->carrier_link_up = false;
503 trigger_data->link_speed = SPEED_UNKNOWN;
504 trigger_data->duplex = DUPLEX_UNKNOWN;
505 switch (evt) {
506 case NETDEV_CHANGENAME:
507 get_device_state(trigger_data);
508 fallthrough;
509 case NETDEV_REGISTER:
510 dev_put(trigger_data->net_dev);
511 dev_hold(dev);
512 trigger_data->net_dev = dev;
513 break;
514 case NETDEV_UNREGISTER:
515 dev_put(trigger_data->net_dev);
516 trigger_data->net_dev = NULL;
517 break;
518 case NETDEV_UP:
519 case NETDEV_CHANGE:
520 get_device_state(trigger_data);
521 break;
522 }
523
524 set_baseline_state(trigger_data);
525
526 mutex_unlock(&trigger_data->lock);
527
528 return NOTIFY_DONE;
529}
530
531/* here's the real work! */
532static void netdev_trig_work(struct work_struct *work)
533{
534 struct led_netdev_data *trigger_data =
535 container_of(work, struct led_netdev_data, work.work);
536 struct rtnl_link_stats64 *dev_stats;
537 unsigned int new_activity;
538 struct rtnl_link_stats64 temp;
539 unsigned long interval;
540 int invert;
541
542 /* If we dont have a device, insure we are off */
543 if (!trigger_data->net_dev) {
544 led_set_brightness(trigger_data->led_cdev, LED_OFF);
545 return;
546 }
547
548 /* If we are not looking for RX/TX then return */
549 if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
550 !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
551 return;
552
553 dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
554 new_activity =
555 (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
556 dev_stats->tx_packets : 0) +
557 (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
558 dev_stats->rx_packets : 0);
559
560 if (trigger_data->last_activity != new_activity) {
561 led_stop_software_blink(trigger_data->led_cdev);
562
563 invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
564 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
565 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
566 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
567 test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) ||
568 test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) ||
569 test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) ||
570 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
571 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
572 interval = jiffies_to_msecs(
573 atomic_read(&trigger_data->interval));
574 /* base state is ON (link present) */
575 led_blink_set_oneshot(trigger_data->led_cdev,
576 &interval,
577 &interval,
578 invert);
579 trigger_data->last_activity = new_activity;
580 }
581
582 schedule_delayed_work(&trigger_data->work,
583 (atomic_read(&trigger_data->interval)*2));
584}
585
586static int netdev_trig_activate(struct led_classdev *led_cdev)
587{
588 struct led_netdev_data *trigger_data;
589 unsigned long mode = 0;
590 struct device *dev;
591 int rc;
592
593 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
594 if (!trigger_data)
595 return -ENOMEM;
596
597 mutex_init(&trigger_data->lock);
598
599 trigger_data->notifier.notifier_call = netdev_trig_notify;
600 trigger_data->notifier.priority = 10;
601
602 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
603
604 trigger_data->led_cdev = led_cdev;
605 trigger_data->net_dev = NULL;
606 trigger_data->device_name[0] = 0;
607
608 trigger_data->mode = 0;
609 atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
610 trigger_data->last_activity = 0;
611
612 /* Check if hw control is active by default on the LED.
613 * Init already enabled mode in hw control.
614 */
615 if (supports_hw_control(led_cdev)) {
616 dev = led_cdev->hw_control_get_device(led_cdev);
617 if (dev) {
618 const char *name = dev_name(dev);
619
620 set_device_name(trigger_data, name, strlen(name));
621 trigger_data->hw_control = true;
622
623 rc = led_cdev->hw_control_get(led_cdev, &mode);
624 if (!rc)
625 trigger_data->mode = mode;
626 }
627 }
628
629 led_set_trigger_data(led_cdev, trigger_data);
630
631 rc = register_netdevice_notifier(&trigger_data->notifier);
632 if (rc)
633 kfree(trigger_data);
634
635 return rc;
636}
637
638static void netdev_trig_deactivate(struct led_classdev *led_cdev)
639{
640 struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
641
642 unregister_netdevice_notifier(&trigger_data->notifier);
643
644 cancel_delayed_work_sync(&trigger_data->work);
645
646 led_set_brightness(led_cdev, LED_OFF);
647
648 dev_put(trigger_data->net_dev);
649
650 kfree(trigger_data);
651}
652
653static struct led_trigger netdev_led_trigger = {
654 .name = "netdev",
655 .activate = netdev_trig_activate,
656 .deactivate = netdev_trig_deactivate,
657 .groups = netdev_trig_groups,
658};
659
660module_led_trigger(netdev_led_trigger);
661
662MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
663MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
664MODULE_DESCRIPTION("Netdev LED trigger");
665MODULE_LICENSE("GPL v2");
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/init.h>
17#include <linux/jiffies.h>
18#include <linux/kernel.h>
19#include <linux/leds.h>
20#include <linux/list.h>
21#include <linux/module.h>
22#include <linux/netdevice.h>
23#include <linux/spinlock.h>
24#include <linux/timer.h>
25#include "../leds.h"
26
27/*
28 * Configurable sysfs attributes:
29 *
30 * device_name - network device name to monitor
31 * interval - duration of LED blink, in milliseconds
32 * link - LED's normal state reflects whether the link is up
33 * (has carrier) or not
34 * tx - LED blinks on transmitted data
35 * rx - LED blinks on receive data
36 *
37 */
38
39struct led_netdev_data {
40 spinlock_t lock;
41
42 struct delayed_work work;
43 struct notifier_block notifier;
44
45 struct led_classdev *led_cdev;
46 struct net_device *net_dev;
47
48 char device_name[IFNAMSIZ];
49 atomic_t interval;
50 unsigned int last_activity;
51
52 unsigned long mode;
53#define NETDEV_LED_LINK 0
54#define NETDEV_LED_TX 1
55#define NETDEV_LED_RX 2
56#define NETDEV_LED_MODE_LINKUP 3
57};
58
59enum netdev_led_attr {
60 NETDEV_ATTR_LINK,
61 NETDEV_ATTR_TX,
62 NETDEV_ATTR_RX
63};
64
65static 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 current_brightness = led_cdev->brightness;
71 if (current_brightness)
72 led_cdev->blink_brightness = current_brightness;
73 if (!led_cdev->blink_brightness)
74 led_cdev->blink_brightness = led_cdev->max_brightness;
75
76 if (!test_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode))
77 led_set_brightness(led_cdev, LED_OFF);
78 else {
79 if (test_bit(NETDEV_LED_LINK, &trigger_data->mode))
80 led_set_brightness(led_cdev,
81 led_cdev->blink_brightness);
82 else
83 led_set_brightness(led_cdev, LED_OFF);
84
85 /* If we are looking for RX/TX start periodically
86 * checking stats
87 */
88 if (test_bit(NETDEV_LED_TX, &trigger_data->mode) ||
89 test_bit(NETDEV_LED_RX, &trigger_data->mode))
90 schedule_delayed_work(&trigger_data->work, 0);
91 }
92}
93
94static ssize_t device_name_show(struct device *dev,
95 struct device_attribute *attr, char *buf)
96{
97 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
98 ssize_t len;
99
100 spin_lock_bh(&trigger_data->lock);
101 len = sprintf(buf, "%s\n", trigger_data->device_name);
102 spin_unlock_bh(&trigger_data->lock);
103
104 return len;
105}
106
107static ssize_t device_name_store(struct device *dev,
108 struct device_attribute *attr, const char *buf,
109 size_t size)
110{
111 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
112
113 if (size >= IFNAMSIZ)
114 return -EINVAL;
115
116 cancel_delayed_work_sync(&trigger_data->work);
117
118 spin_lock_bh(&trigger_data->lock);
119
120 if (trigger_data->net_dev) {
121 dev_put(trigger_data->net_dev);
122 trigger_data->net_dev = NULL;
123 }
124
125 memcpy(trigger_data->device_name, buf, size);
126 trigger_data->device_name[size] = 0;
127 if (size > 0 && trigger_data->device_name[size - 1] == '\n')
128 trigger_data->device_name[size - 1] = 0;
129
130 if (trigger_data->device_name[0] != 0)
131 trigger_data->net_dev =
132 dev_get_by_name(&init_net, trigger_data->device_name);
133
134 clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
135 if (trigger_data->net_dev != NULL)
136 if (netif_carrier_ok(trigger_data->net_dev))
137 set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
138
139 trigger_data->last_activity = 0;
140
141 set_baseline_state(trigger_data);
142 spin_unlock_bh(&trigger_data->lock);
143
144 return size;
145}
146
147static DEVICE_ATTR_RW(device_name);
148
149static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
150 enum netdev_led_attr attr)
151{
152 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
153 int bit;
154
155 switch (attr) {
156 case NETDEV_ATTR_LINK:
157 bit = NETDEV_LED_LINK;
158 break;
159 case NETDEV_ATTR_TX:
160 bit = NETDEV_LED_TX;
161 break;
162 case NETDEV_ATTR_RX:
163 bit = NETDEV_LED_RX;
164 break;
165 default:
166 return -EINVAL;
167 }
168
169 return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
170}
171
172static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
173 size_t size, enum netdev_led_attr attr)
174{
175 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
176 unsigned long state;
177 int ret;
178 int bit;
179
180 ret = kstrtoul(buf, 0, &state);
181 if (ret)
182 return ret;
183
184 switch (attr) {
185 case NETDEV_ATTR_LINK:
186 bit = NETDEV_LED_LINK;
187 break;
188 case NETDEV_ATTR_TX:
189 bit = NETDEV_LED_TX;
190 break;
191 case NETDEV_ATTR_RX:
192 bit = NETDEV_LED_RX;
193 break;
194 default:
195 return -EINVAL;
196 }
197
198 cancel_delayed_work_sync(&trigger_data->work);
199
200 if (state)
201 set_bit(bit, &trigger_data->mode);
202 else
203 clear_bit(bit, &trigger_data->mode);
204
205 set_baseline_state(trigger_data);
206
207 return size;
208}
209
210static ssize_t link_show(struct device *dev,
211 struct device_attribute *attr, char *buf)
212{
213 return netdev_led_attr_show(dev, buf, NETDEV_ATTR_LINK);
214}
215
216static ssize_t link_store(struct device *dev,
217 struct device_attribute *attr, const char *buf, size_t size)
218{
219 return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_LINK);
220}
221
222static DEVICE_ATTR_RW(link);
223
224static ssize_t tx_show(struct device *dev,
225 struct device_attribute *attr, char *buf)
226{
227 return netdev_led_attr_show(dev, buf, NETDEV_ATTR_TX);
228}
229
230static ssize_t tx_store(struct device *dev,
231 struct device_attribute *attr, const char *buf, size_t size)
232{
233 return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_TX);
234}
235
236static DEVICE_ATTR_RW(tx);
237
238static ssize_t rx_show(struct device *dev,
239 struct device_attribute *attr, char *buf)
240{
241 return netdev_led_attr_show(dev, buf, NETDEV_ATTR_RX);
242}
243
244static ssize_t rx_store(struct device *dev,
245 struct device_attribute *attr, const char *buf, size_t size)
246{
247 return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_RX);
248}
249
250static DEVICE_ATTR_RW(rx);
251
252static ssize_t interval_show(struct device *dev,
253 struct device_attribute *attr, char *buf)
254{
255 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
256
257 return sprintf(buf, "%u\n",
258 jiffies_to_msecs(atomic_read(&trigger_data->interval)));
259}
260
261static ssize_t interval_store(struct device *dev,
262 struct device_attribute *attr, const char *buf,
263 size_t size)
264{
265 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
266 unsigned long value;
267 int ret;
268
269 ret = kstrtoul(buf, 0, &value);
270 if (ret)
271 return ret;
272
273 /* impose some basic bounds on the timer interval */
274 if (value >= 5 && value <= 10000) {
275 cancel_delayed_work_sync(&trigger_data->work);
276
277 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
278 set_baseline_state(trigger_data); /* resets timer */
279 }
280
281 return size;
282}
283
284static DEVICE_ATTR_RW(interval);
285
286static struct attribute *netdev_trig_attrs[] = {
287 &dev_attr_device_name.attr,
288 &dev_attr_link.attr,
289 &dev_attr_rx.attr,
290 &dev_attr_tx.attr,
291 &dev_attr_interval.attr,
292 NULL
293};
294ATTRIBUTE_GROUPS(netdev_trig);
295
296static int netdev_trig_notify(struct notifier_block *nb,
297 unsigned long evt, void *dv)
298{
299 struct net_device *dev =
300 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
301 struct led_netdev_data *trigger_data =
302 container_of(nb, struct led_netdev_data, notifier);
303
304 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
305 && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
306 && evt != NETDEV_CHANGENAME)
307 return NOTIFY_DONE;
308
309 if (!(dev == trigger_data->net_dev ||
310 (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
311 (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
312 return NOTIFY_DONE;
313
314 cancel_delayed_work_sync(&trigger_data->work);
315
316 spin_lock_bh(&trigger_data->lock);
317
318 clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
319 switch (evt) {
320 case NETDEV_CHANGENAME:
321 case NETDEV_REGISTER:
322 if (trigger_data->net_dev)
323 dev_put(trigger_data->net_dev);
324 dev_hold(dev);
325 trigger_data->net_dev = dev;
326 break;
327 case NETDEV_UNREGISTER:
328 dev_put(trigger_data->net_dev);
329 trigger_data->net_dev = NULL;
330 break;
331 case NETDEV_UP:
332 case NETDEV_CHANGE:
333 if (netif_carrier_ok(dev))
334 set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
335 break;
336 }
337
338 set_baseline_state(trigger_data);
339
340 spin_unlock_bh(&trigger_data->lock);
341
342 return NOTIFY_DONE;
343}
344
345/* here's the real work! */
346static void netdev_trig_work(struct work_struct *work)
347{
348 struct led_netdev_data *trigger_data =
349 container_of(work, struct led_netdev_data, work.work);
350 struct rtnl_link_stats64 *dev_stats;
351 unsigned int new_activity;
352 struct rtnl_link_stats64 temp;
353 unsigned long interval;
354 int invert;
355
356 /* If we dont have a device, insure we are off */
357 if (!trigger_data->net_dev) {
358 led_set_brightness(trigger_data->led_cdev, LED_OFF);
359 return;
360 }
361
362 /* If we are not looking for RX/TX then return */
363 if (!test_bit(NETDEV_LED_TX, &trigger_data->mode) &&
364 !test_bit(NETDEV_LED_RX, &trigger_data->mode))
365 return;
366
367 dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
368 new_activity =
369 (test_bit(NETDEV_LED_TX, &trigger_data->mode) ?
370 dev_stats->tx_packets : 0) +
371 (test_bit(NETDEV_LED_RX, &trigger_data->mode) ?
372 dev_stats->rx_packets : 0);
373
374 if (trigger_data->last_activity != new_activity) {
375 led_stop_software_blink(trigger_data->led_cdev);
376
377 invert = test_bit(NETDEV_LED_LINK, &trigger_data->mode);
378 interval = jiffies_to_msecs(
379 atomic_read(&trigger_data->interval));
380 /* base state is ON (link present) */
381 led_blink_set_oneshot(trigger_data->led_cdev,
382 &interval,
383 &interval,
384 invert);
385 trigger_data->last_activity = new_activity;
386 }
387
388 schedule_delayed_work(&trigger_data->work,
389 (atomic_read(&trigger_data->interval)*2));
390}
391
392static int netdev_trig_activate(struct led_classdev *led_cdev)
393{
394 struct led_netdev_data *trigger_data;
395 int rc;
396
397 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
398 if (!trigger_data)
399 return -ENOMEM;
400
401 spin_lock_init(&trigger_data->lock);
402
403 trigger_data->notifier.notifier_call = netdev_trig_notify;
404 trigger_data->notifier.priority = 10;
405
406 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
407
408 trigger_data->led_cdev = led_cdev;
409 trigger_data->net_dev = NULL;
410 trigger_data->device_name[0] = 0;
411
412 trigger_data->mode = 0;
413 atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
414 trigger_data->last_activity = 0;
415
416 led_set_trigger_data(led_cdev, trigger_data);
417
418 rc = register_netdevice_notifier(&trigger_data->notifier);
419 if (rc)
420 kfree(trigger_data);
421
422 return rc;
423}
424
425static void netdev_trig_deactivate(struct led_classdev *led_cdev)
426{
427 struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
428
429 unregister_netdevice_notifier(&trigger_data->notifier);
430
431 cancel_delayed_work_sync(&trigger_data->work);
432
433 if (trigger_data->net_dev)
434 dev_put(trigger_data->net_dev);
435
436 kfree(trigger_data);
437}
438
439static struct led_trigger netdev_led_trigger = {
440 .name = "netdev",
441 .activate = netdev_trig_activate,
442 .deactivate = netdev_trig_deactivate,
443 .groups = netdev_trig_groups,
444};
445
446static int __init netdev_trig_init(void)
447{
448 return led_trigger_register(&netdev_led_trigger);
449}
450
451static void __exit netdev_trig_exit(void)
452{
453 led_trigger_unregister(&netdev_led_trigger);
454}
455
456module_init(netdev_trig_init);
457module_exit(netdev_trig_exit);
458
459MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
460MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
461MODULE_DESCRIPTION("Netdev LED trigger");
462MODULE_LICENSE("GPL v2");