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
39 struct 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
59 enum netdev_led_attr {
60 NETDEV_ATTR_LINK,
61 NETDEV_ATTR_TX,
62 NETDEV_ATTR_RX
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 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
device_name_show(struct device * dev,struct device_attribute * attr,char * buf)94 static 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
device_name_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)107 static 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
147 static DEVICE_ATTR_RW(device_name);
148
netdev_led_attr_show(struct device * dev,char * buf,enum netdev_led_attr attr)149 static 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
netdev_led_attr_store(struct device * dev,const char * buf,size_t size,enum netdev_led_attr attr)172 static 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
link_show(struct device * dev,struct device_attribute * attr,char * buf)210 static 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
link_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)216 static 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
222 static DEVICE_ATTR_RW(link);
223
tx_show(struct device * dev,struct device_attribute * attr,char * buf)224 static 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
tx_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)230 static 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
236 static DEVICE_ATTR_RW(tx);
237
rx_show(struct device * dev,struct device_attribute * attr,char * buf)238 static 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
rx_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)244 static 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
250 static DEVICE_ATTR_RW(rx);
251
interval_show(struct device * dev,struct device_attribute * attr,char * buf)252 static 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
interval_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)261 static 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
284 static DEVICE_ATTR_RW(interval);
285
286 static 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 };
294 ATTRIBUTE_GROUPS(netdev_trig);
295
netdev_trig_notify(struct notifier_block * nb,unsigned long evt,void * dv)296 static 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 if (netif_carrier_ok(dev))
322 set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
323 fallthrough;
324 case NETDEV_REGISTER:
325 if (trigger_data->net_dev)
326 dev_put(trigger_data->net_dev);
327 dev_hold(dev);
328 trigger_data->net_dev = dev;
329 break;
330 case NETDEV_UNREGISTER:
331 dev_put(trigger_data->net_dev);
332 trigger_data->net_dev = NULL;
333 break;
334 case NETDEV_UP:
335 case NETDEV_CHANGE:
336 if (netif_carrier_ok(dev))
337 set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
338 break;
339 }
340
341 set_baseline_state(trigger_data);
342
343 spin_unlock_bh(&trigger_data->lock);
344
345 return NOTIFY_DONE;
346 }
347
348 /* here's the real work! */
netdev_trig_work(struct work_struct * work)349 static void netdev_trig_work(struct work_struct *work)
350 {
351 struct led_netdev_data *trigger_data =
352 container_of(work, struct led_netdev_data, work.work);
353 struct rtnl_link_stats64 *dev_stats;
354 unsigned int new_activity;
355 struct rtnl_link_stats64 temp;
356 unsigned long interval;
357 int invert;
358
359 /* If we dont have a device, insure we are off */
360 if (!trigger_data->net_dev) {
361 led_set_brightness(trigger_data->led_cdev, LED_OFF);
362 return;
363 }
364
365 /* If we are not looking for RX/TX then return */
366 if (!test_bit(NETDEV_LED_TX, &trigger_data->mode) &&
367 !test_bit(NETDEV_LED_RX, &trigger_data->mode))
368 return;
369
370 dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
371 new_activity =
372 (test_bit(NETDEV_LED_TX, &trigger_data->mode) ?
373 dev_stats->tx_packets : 0) +
374 (test_bit(NETDEV_LED_RX, &trigger_data->mode) ?
375 dev_stats->rx_packets : 0);
376
377 if (trigger_data->last_activity != new_activity) {
378 led_stop_software_blink(trigger_data->led_cdev);
379
380 invert = test_bit(NETDEV_LED_LINK, &trigger_data->mode);
381 interval = jiffies_to_msecs(
382 atomic_read(&trigger_data->interval));
383 /* base state is ON (link present) */
384 led_blink_set_oneshot(trigger_data->led_cdev,
385 &interval,
386 &interval,
387 invert);
388 trigger_data->last_activity = new_activity;
389 }
390
391 schedule_delayed_work(&trigger_data->work,
392 (atomic_read(&trigger_data->interval)*2));
393 }
394
netdev_trig_activate(struct led_classdev * led_cdev)395 static int netdev_trig_activate(struct led_classdev *led_cdev)
396 {
397 struct led_netdev_data *trigger_data;
398 int rc;
399
400 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
401 if (!trigger_data)
402 return -ENOMEM;
403
404 spin_lock_init(&trigger_data->lock);
405
406 trigger_data->notifier.notifier_call = netdev_trig_notify;
407 trigger_data->notifier.priority = 10;
408
409 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
410
411 trigger_data->led_cdev = led_cdev;
412 trigger_data->net_dev = NULL;
413 trigger_data->device_name[0] = 0;
414
415 trigger_data->mode = 0;
416 atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
417 trigger_data->last_activity = 0;
418
419 led_set_trigger_data(led_cdev, trigger_data);
420
421 rc = register_netdevice_notifier(&trigger_data->notifier);
422 if (rc)
423 kfree(trigger_data);
424
425 return rc;
426 }
427
netdev_trig_deactivate(struct led_classdev * led_cdev)428 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
429 {
430 struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
431
432 unregister_netdevice_notifier(&trigger_data->notifier);
433
434 cancel_delayed_work_sync(&trigger_data->work);
435
436 if (trigger_data->net_dev)
437 dev_put(trigger_data->net_dev);
438
439 kfree(trigger_data);
440 }
441
442 static struct led_trigger netdev_led_trigger = {
443 .name = "netdev",
444 .activate = netdev_trig_activate,
445 .deactivate = netdev_trig_deactivate,
446 .groups = netdev_trig_groups,
447 };
448
netdev_trig_init(void)449 static int __init netdev_trig_init(void)
450 {
451 return led_trigger_register(&netdev_led_trigger);
452 }
453
netdev_trig_exit(void)454 static void __exit netdev_trig_exit(void)
455 {
456 led_trigger_unregister(&netdev_led_trigger);
457 }
458
459 module_init(netdev_trig_init);
460 module_exit(netdev_trig_exit);
461
462 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
463 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
464 MODULE_DESCRIPTION("Netdev LED trigger");
465 MODULE_LICENSE("GPL v2");
466