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
43struct 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
64static 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
125static 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 */
138static 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
152static 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
194static 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
208static 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
221static int set_device_name(struct led_netdev_data *trigger_data,
222			   const char *name, size_t size)
223{
224	if (size >= IFNAMSIZ)
225		return -EINVAL;
226
227	cancel_delayed_work_sync(&trigger_data->work);
228
229	/*
230	 * Take RTNL lock before trigger_data lock to prevent potential
231	 * deadlock with netdev notifier registration.
232	 */
233	rtnl_lock();
234	mutex_lock(&trigger_data->lock);
235
236	if (trigger_data->net_dev) {
237		dev_put(trigger_data->net_dev);
238		trigger_data->net_dev = NULL;
239	}
240
241	memcpy(trigger_data->device_name, name, size);
242	trigger_data->device_name[size] = 0;
243	if (size > 0 && trigger_data->device_name[size - 1] == '\n')
244		trigger_data->device_name[size - 1] = 0;
245
246	if (trigger_data->device_name[0] != 0)
247		trigger_data->net_dev =
248		    dev_get_by_name(&init_net, trigger_data->device_name);
249
250	trigger_data->carrier_link_up = false;
251	trigger_data->link_speed = SPEED_UNKNOWN;
252	trigger_data->duplex = DUPLEX_UNKNOWN;
253	if (trigger_data->net_dev)
254		get_device_state(trigger_data);
255
256	trigger_data->last_activity = 0;
257
258	set_baseline_state(trigger_data);
259	mutex_unlock(&trigger_data->lock);
260	rtnl_unlock();
261
262	return 0;
263}
264
265static ssize_t device_name_store(struct device *dev,
266				 struct device_attribute *attr, const char *buf,
267				 size_t size)
268{
269	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
270	int ret;
271
272	ret = set_device_name(trigger_data, buf, size);
273
274	if (ret < 0)
275		return ret;
276	return size;
277}
278
279static DEVICE_ATTR_RW(device_name);
280
281static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
282				    enum led_trigger_netdev_modes attr)
283{
284	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
285	int bit;
286
287	switch (attr) {
288	case TRIGGER_NETDEV_LINK:
289	case TRIGGER_NETDEV_LINK_10:
290	case TRIGGER_NETDEV_LINK_100:
291	case TRIGGER_NETDEV_LINK_1000:
292	case TRIGGER_NETDEV_HALF_DUPLEX:
293	case TRIGGER_NETDEV_FULL_DUPLEX:
294	case TRIGGER_NETDEV_TX:
295	case TRIGGER_NETDEV_RX:
296		bit = attr;
297		break;
298	default:
299		return -EINVAL;
300	}
301
302	return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
303}
304
305static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
306				     size_t size, enum led_trigger_netdev_modes attr)
307{
308	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
309	unsigned long state, mode = trigger_data->mode;
310	int ret;
311	int bit;
312
313	ret = kstrtoul(buf, 0, &state);
314	if (ret)
315		return ret;
316
317	switch (attr) {
318	case TRIGGER_NETDEV_LINK:
319	case TRIGGER_NETDEV_LINK_10:
320	case TRIGGER_NETDEV_LINK_100:
321	case TRIGGER_NETDEV_LINK_1000:
322	case TRIGGER_NETDEV_HALF_DUPLEX:
323	case TRIGGER_NETDEV_FULL_DUPLEX:
324	case TRIGGER_NETDEV_TX:
325	case TRIGGER_NETDEV_RX:
326		bit = attr;
327		break;
328	default:
329		return -EINVAL;
330	}
331
332	if (state)
333		set_bit(bit, &mode);
334	else
335		clear_bit(bit, &mode);
336
337	if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
338	    (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
339	     test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
340	     test_bit(TRIGGER_NETDEV_LINK_1000, &mode)))
341		return -EINVAL;
342
343	cancel_delayed_work_sync(&trigger_data->work);
344
345	trigger_data->mode = mode;
346	trigger_data->hw_control = can_hw_control(trigger_data);
347
348	set_baseline_state(trigger_data);
349
350	return size;
351}
352
353#define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
354	static ssize_t trigger_name##_show(struct device *dev, \
355		struct device_attribute *attr, char *buf) \
356	{ \
357		return netdev_led_attr_show(dev, buf, trigger); \
358	} \
359	static ssize_t trigger_name##_store(struct device *dev, \
360		struct device_attribute *attr, const char *buf, size_t size) \
361	{ \
362		return netdev_led_attr_store(dev, buf, size, trigger); \
363	} \
364	static DEVICE_ATTR_RW(trigger_name)
365
366DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
367DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
368DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
369DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
370DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
371DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
372DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
373DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
374
375static ssize_t interval_show(struct device *dev,
376			     struct device_attribute *attr, char *buf)
377{
378	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
379
380	return sprintf(buf, "%u\n",
381		       jiffies_to_msecs(atomic_read(&trigger_data->interval)));
382}
383
384static ssize_t interval_store(struct device *dev,
385			      struct device_attribute *attr, const char *buf,
386			      size_t size)
387{
388	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
389	unsigned long value;
390	int ret;
391
392	if (trigger_data->hw_control)
393		return -EINVAL;
394
395	ret = kstrtoul(buf, 0, &value);
396	if (ret)
397		return ret;
398
399	/* impose some basic bounds on the timer interval */
400	if (value >= 5 && value <= 10000) {
401		cancel_delayed_work_sync(&trigger_data->work);
402
403		atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
404		set_baseline_state(trigger_data);	/* resets timer */
405	}
406
407	return size;
408}
409
410static DEVICE_ATTR_RW(interval);
411
412static ssize_t offloaded_show(struct device *dev,
413			      struct device_attribute *attr, char *buf)
414{
415	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
416
417	return sprintf(buf, "%d\n", trigger_data->hw_control);
418}
419
420static DEVICE_ATTR_RO(offloaded);
421
422static struct attribute *netdev_trig_attrs[] = {
423	&dev_attr_device_name.attr,
424	&dev_attr_link.attr,
425	&dev_attr_link_10.attr,
426	&dev_attr_link_100.attr,
427	&dev_attr_link_1000.attr,
428	&dev_attr_full_duplex.attr,
429	&dev_attr_half_duplex.attr,
430	&dev_attr_rx.attr,
431	&dev_attr_tx.attr,
432	&dev_attr_interval.attr,
433	&dev_attr_offloaded.attr,
434	NULL
435};
436ATTRIBUTE_GROUPS(netdev_trig);
437
438static int netdev_trig_notify(struct notifier_block *nb,
439			      unsigned long evt, void *dv)
440{
441	struct net_device *dev =
442		netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
443	struct led_netdev_data *trigger_data =
444		container_of(nb, struct led_netdev_data, notifier);
445
446	if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
447	    && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
448	    && evt != NETDEV_CHANGENAME)
449		return NOTIFY_DONE;
450
451	if (!(dev == trigger_data->net_dev ||
452	      (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
453	      (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
454		return NOTIFY_DONE;
455
456	cancel_delayed_work_sync(&trigger_data->work);
457
458	mutex_lock(&trigger_data->lock);
459
460	trigger_data->carrier_link_up = false;
461	trigger_data->link_speed = SPEED_UNKNOWN;
462	trigger_data->duplex = DUPLEX_UNKNOWN;
463	switch (evt) {
464	case NETDEV_CHANGENAME:
465	case NETDEV_REGISTER:
466		dev_put(trigger_data->net_dev);
467		dev_hold(dev);
468		trigger_data->net_dev = dev;
469		if (evt == NETDEV_CHANGENAME)
470			get_device_state(trigger_data);
471		break;
472	case NETDEV_UNREGISTER:
473		dev_put(trigger_data->net_dev);
474		trigger_data->net_dev = NULL;
475		break;
476	case NETDEV_UP:
477	case NETDEV_CHANGE:
478		get_device_state(trigger_data);
479		break;
480	}
481
482	set_baseline_state(trigger_data);
483
484	mutex_unlock(&trigger_data->lock);
485
486	return NOTIFY_DONE;
487}
488
489/* here's the real work! */
490static void netdev_trig_work(struct work_struct *work)
491{
492	struct led_netdev_data *trigger_data =
493		container_of(work, struct led_netdev_data, work.work);
494	struct rtnl_link_stats64 *dev_stats;
495	unsigned int new_activity;
496	struct rtnl_link_stats64 temp;
497	unsigned long interval;
498	int invert;
499
500	/* If we dont have a device, insure we are off */
501	if (!trigger_data->net_dev) {
502		led_set_brightness(trigger_data->led_cdev, LED_OFF);
503		return;
504	}
505
506	/* If we are not looking for RX/TX then return  */
507	if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
508	    !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode))
509		return;
510
511	dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
512	new_activity =
513	    (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
514		dev_stats->tx_packets : 0) +
515	    (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
516		dev_stats->rx_packets : 0);
517
518	if (trigger_data->last_activity != new_activity) {
519		led_stop_software_blink(trigger_data->led_cdev);
520
521		invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
522			 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
523			 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
524			 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
525			 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
526			 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
527		interval = jiffies_to_msecs(
528				atomic_read(&trigger_data->interval));
529		/* base state is ON (link present) */
530		led_blink_set_oneshot(trigger_data->led_cdev,
531				      &interval,
532				      &interval,
533				      invert);
534		trigger_data->last_activity = new_activity;
535	}
536
537	schedule_delayed_work(&trigger_data->work,
538			(atomic_read(&trigger_data->interval)*2));
539}
540
541static int netdev_trig_activate(struct led_classdev *led_cdev)
542{
543	struct led_netdev_data *trigger_data;
544	unsigned long mode = 0;
545	struct device *dev;
546	int rc;
547
548	trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
549	if (!trigger_data)
550		return -ENOMEM;
551
552	mutex_init(&trigger_data->lock);
553
554	trigger_data->notifier.notifier_call = netdev_trig_notify;
555	trigger_data->notifier.priority = 10;
556
557	INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
558
559	trigger_data->led_cdev = led_cdev;
560	trigger_data->net_dev = NULL;
561	trigger_data->device_name[0] = 0;
562
563	trigger_data->mode = 0;
564	atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
565	trigger_data->last_activity = 0;
566
567	/* Check if hw control is active by default on the LED.
568	 * Init already enabled mode in hw control.
569	 */
570	if (supports_hw_control(led_cdev)) {
571		dev = led_cdev->hw_control_get_device(led_cdev);
572		if (dev) {
573			const char *name = dev_name(dev);
574
575			set_device_name(trigger_data, name, strlen(name));
576			trigger_data->hw_control = true;
577
578			rc = led_cdev->hw_control_get(led_cdev, &mode);
579			if (!rc)
580				trigger_data->mode = mode;
581		}
582	}
583
584	led_set_trigger_data(led_cdev, trigger_data);
585
586	rc = register_netdevice_notifier(&trigger_data->notifier);
587	if (rc)
588		kfree(trigger_data);
589
590	return rc;
591}
592
593static void netdev_trig_deactivate(struct led_classdev *led_cdev)
594{
595	struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
596
597	unregister_netdevice_notifier(&trigger_data->notifier);
598
599	cancel_delayed_work_sync(&trigger_data->work);
600
601	led_set_brightness(led_cdev, LED_OFF);
602
603	dev_put(trigger_data->net_dev);
604
605	kfree(trigger_data);
606}
607
608static struct led_trigger netdev_led_trigger = {
609	.name = "netdev",
610	.activate = netdev_trig_activate,
611	.deactivate = netdev_trig_deactivate,
612	.groups = netdev_trig_groups,
613};
614
615module_led_trigger(netdev_led_trigger);
616
617MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
618MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
619MODULE_DESCRIPTION("Netdev LED trigger");
620MODULE_LICENSE("GPL v2");
621