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 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
device_name_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)265 static 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
279 static DEVICE_ATTR_RW(device_name);
280
netdev_led_attr_show(struct device * dev,char * buf,enum led_trigger_netdev_modes attr)281 static 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
netdev_led_attr_store(struct device * dev,const char * buf,size_t size,enum led_trigger_netdev_modes attr)305 static 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
366 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
367 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
368 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
369 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
370 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
371 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
372 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
373 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
374
interval_show(struct device * dev,struct device_attribute * attr,char * buf)375 static 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
interval_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)384 static 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
410 static DEVICE_ATTR_RW(interval);
411
offloaded_show(struct device * dev,struct device_attribute * attr,char * buf)412 static 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
420 static DEVICE_ATTR_RO(offloaded);
421
422 static 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 };
436 ATTRIBUTE_GROUPS(netdev_trig);
437
netdev_trig_notify(struct notifier_block * nb,unsigned long evt,void * dv)438 static 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 get_device_state(trigger_data);
466 fallthrough;
467 case NETDEV_REGISTER:
468 dev_put(trigger_data->net_dev);
469 dev_hold(dev);
470 trigger_data->net_dev = dev;
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! */
netdev_trig_work(struct work_struct * work)490 static 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
netdev_trig_activate(struct led_classdev * led_cdev)541 static 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
netdev_trig_deactivate(struct led_classdev * led_cdev)593 static 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
608 static 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
615 module_led_trigger(netdev_led_trigger);
616
617 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
618 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
619 MODULE_DESCRIPTION("Netdev LED trigger");
620 MODULE_LICENSE("GPL v2");
621