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4 office 1 /*
2 * LED Kernel Netdev Trigger
3 *
4 * Toggles the LED to reflect the link and traffic state of a named net device
5 *
6 * Copyright 2007 Oliver Jowett <oliver@opencloud.com>
7 *
8 * Derived from ledtrig-timer.c which is:
9 * Copyright 2005-2006 Openedhand Ltd.
10 * Author: Richard Purdie <rpurdie@openedhand.com>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 *
16 */
17  
18 #include <linux/module.h>
19 #include <linux/jiffies.h>
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/list.h>
23 #include <linux/spinlock.h>
24 #include <linux/device.h>
25 #include <linux/netdevice.h>
26 #include <linux/timer.h>
27 #include <linux/ctype.h>
28 #include <linux/leds.h>
29  
30 #include "leds.h"
31  
32 /*
33 * Configurable sysfs attributes:
34 *
35 * device_name - network device name to monitor
36 *
37 * interval - duration of LED blink, in milliseconds
38 *
39 * mode - either "none" (LED is off) or a space separated list of one or more of:
40 * link: LED's normal state reflects whether the link is up (has carrier) or not
41 * tx: LED blinks on transmitted data
42 * rx: LED blinks on receive data
43 *
44 * Some suggestions:
45 *
46 * Simple link status LED:
47 * $ echo netdev >someled/trigger
48 * $ echo eth0 >someled/device_name
49 * $ echo link >someled/mode
50 *
51 * Ethernet-style link/activity LED:
52 * $ echo netdev >someled/trigger
53 * $ echo eth0 >someled/device_name
54 * $ echo "link tx rx" >someled/mode
55 *
56 * Modem-style tx/rx LEDs:
57 * $ echo netdev >led1/trigger
58 * $ echo ppp0 >led1/device_name
59 * $ echo tx >led1/mode
60 * $ echo netdev >led2/trigger
61 * $ echo ppp0 >led2/device_name
62 * $ echo rx >led2/mode
63 *
64 */
65  
66 #define MODE_LINK 1
67 #define MODE_TX 2
68 #define MODE_RX 4
69  
70 struct led_netdev_data {
71 spinlock_t lock;
72  
73 struct delayed_work work;
74 struct notifier_block notifier;
75  
76 struct led_classdev *led_cdev;
77 struct net_device *net_dev;
78  
79 char device_name[IFNAMSIZ];
80 unsigned interval;
81 unsigned mode;
82 unsigned link_up;
83 unsigned last_activity;
84 };
85  
86 static void set_baseline_state(struct led_netdev_data *trigger_data)
87 {
88 if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
89 led_set_brightness(trigger_data->led_cdev, LED_FULL);
90 else
91 led_set_brightness(trigger_data->led_cdev, LED_OFF);
92  
93 if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up)
94 schedule_delayed_work(&trigger_data->work, trigger_data->interval);
95 }
96  
97 static ssize_t led_device_name_show(struct device *dev,
98 struct device_attribute *attr, char *buf)
99 {
100 struct led_classdev *led_cdev = dev_get_drvdata(dev);
101 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
102  
103 spin_lock_bh(&trigger_data->lock);
104 sprintf(buf, "%s\n", trigger_data->device_name);
105 spin_unlock_bh(&trigger_data->lock);
106  
107 return strlen(buf) + 1;
108 }
109  
110 static ssize_t led_device_name_store(struct device *dev,
111 struct device_attribute *attr, const char *buf, size_t size)
112 {
113 struct led_classdev *led_cdev = dev_get_drvdata(dev);
114 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
115  
116 if (size >= IFNAMSIZ)
117 return -EINVAL;
118  
119 cancel_delayed_work_sync(&trigger_data->work);
120  
121 spin_lock_bh(&trigger_data->lock);
122  
123 strcpy(trigger_data->device_name, buf);
124 if (size > 0 && trigger_data->device_name[size-1] == '\n')
125 trigger_data->device_name[size-1] = 0;
126 trigger_data->link_up = 0;
127 trigger_data->last_activity = 0;
128  
129 if (trigger_data->device_name[0] != 0) {
130 /* check for existing device to update from */
131 trigger_data->net_dev = dev_get_by_name(&init_net, trigger_data->device_name);
132 if (trigger_data->net_dev != NULL)
133 trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
134 }
135  
136 set_baseline_state(trigger_data);
137 spin_unlock_bh(&trigger_data->lock);
138  
139 return size;
140 }
141  
142 static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);
143  
144 static ssize_t led_mode_show(struct device *dev,
145 struct device_attribute *attr, char *buf)
146 {
147 struct led_classdev *led_cdev = dev_get_drvdata(dev);
148 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
149  
150 spin_lock_bh(&trigger_data->lock);
151  
152 if (trigger_data->mode == 0) {
153 strcpy(buf, "none\n");
154 } else {
155 if (trigger_data->mode & MODE_LINK)
156 strcat(buf, "link ");
157 if (trigger_data->mode & MODE_TX)
158 strcat(buf, "tx ");
159 if (trigger_data->mode & MODE_RX)
160 strcat(buf, "rx ");
161 strcat(buf, "\n");
162 }
163  
164 spin_unlock_bh(&trigger_data->lock);
165  
166 return strlen(buf)+1;
167 }
168  
169 static ssize_t led_mode_store(struct device *dev,
170 struct device_attribute *attr, const char *buf, size_t size)
171 {
172 struct led_classdev *led_cdev = dev_get_drvdata(dev);
173 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
174 char copybuf[128];
175 int new_mode = -1;
176 char *p, *token;
177  
178 /* take a copy since we don't want to trash the inbound buffer when using strsep */
179 strncpy(copybuf, buf, sizeof(copybuf));
180 copybuf[sizeof(copybuf) - 1] = 0;
181 p = copybuf;
182  
183 while ((token = strsep(&p, " \t\n")) != NULL) {
184 if (!*token)
185 continue;
186  
187 if (new_mode == -1)
188 new_mode = 0;
189  
190 if (!strcmp(token, "none"))
191 new_mode = 0;
192 else if (!strcmp(token, "tx"))
193 new_mode |= MODE_TX;
194 else if (!strcmp(token, "rx"))
195 new_mode |= MODE_RX;
196 else if (!strcmp(token, "link"))
197 new_mode |= MODE_LINK;
198 else
199 return -EINVAL;
200 }
201  
202 if (new_mode == -1)
203 return -EINVAL;
204  
205 cancel_delayed_work_sync(&trigger_data->work);
206  
207 spin_lock_bh(&trigger_data->lock);
208 trigger_data->mode = new_mode;
209 set_baseline_state(trigger_data);
210 spin_unlock_bh(&trigger_data->lock);
211  
212 return size;
213 }
214  
215 static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);
216  
217 static ssize_t led_interval_show(struct device *dev,
218 struct device_attribute *attr, char *buf)
219 {
220 struct led_classdev *led_cdev = dev_get_drvdata(dev);
221 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
222  
223 spin_lock_bh(&trigger_data->lock);
224 sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
225 spin_unlock_bh(&trigger_data->lock);
226  
227 return strlen(buf) + 1;
228 }
229  
230 static ssize_t led_interval_store(struct device *dev,
231 struct device_attribute *attr, const char *buf, size_t size)
232 {
233 struct led_classdev *led_cdev = dev_get_drvdata(dev);
234 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
235 int ret = -EINVAL;
236 char *after;
237 unsigned long value = simple_strtoul(buf, &after, 10);
238 size_t count = after - buf;
239  
240 if (isspace(*after))
241 count++;
242  
243 /* impose some basic bounds on the timer interval */
244 if (count == size && value >= 5 && value <= 10000) {
245 cancel_delayed_work_sync(&trigger_data->work);
246  
247 spin_lock_bh(&trigger_data->lock);
248 trigger_data->interval = msecs_to_jiffies(value);
249 set_baseline_state(trigger_data); /* resets timer */
250 spin_unlock_bh(&trigger_data->lock);
251  
252 ret = count;
253 }
254  
255 return ret;
256 }
257  
258 static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
259  
260 static int netdev_trig_notify(struct notifier_block *nb,
261 unsigned long evt,
262 void *dv)
263 {
264 struct net_device *dev = netdev_notifier_info_to_dev((struct netdev_notifier_info *) dv);
265 struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
266  
267 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER && evt != NETDEV_CHANGENAME)
268 return NOTIFY_DONE;
269  
270 if (strcmp(dev->name, trigger_data->device_name))
271 return NOTIFY_DONE;
272  
273 cancel_delayed_work_sync(&trigger_data->work);
274  
275 spin_lock_bh(&trigger_data->lock);
276  
277 if (evt == NETDEV_REGISTER || evt == NETDEV_CHANGENAME) {
278 if (trigger_data->net_dev != NULL)
279 dev_put(trigger_data->net_dev);
280  
281 dev_hold(dev);
282 trigger_data->net_dev = dev;
283 trigger_data->link_up = 0;
284 goto done;
285 }
286  
287 if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
288 dev_put(trigger_data->net_dev);
289 trigger_data->net_dev = NULL;
290 goto done;
291 }
292  
293 /* UP / DOWN / CHANGE */
294  
295 trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
296 set_baseline_state(trigger_data);
297  
298 done:
299 spin_unlock_bh(&trigger_data->lock);
300 return NOTIFY_DONE;
301 }
302  
303 /* here's the real work! */
304 static void netdev_trig_work(struct work_struct *work)
305 {
306 struct led_netdev_data *trigger_data = container_of(work, struct led_netdev_data, work.work);
307 struct rtnl_link_stats64 *dev_stats;
308 unsigned new_activity;
309 struct rtnl_link_stats64 temp;
310  
311 if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
312 /* we don't need to do timer work, just reflect link state. */
313 led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
314 return;
315 }
316  
317 dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
318 new_activity =
319 ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
320 ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
321  
322 if (trigger_data->mode & MODE_LINK) {
323 /* base state is ON (link present) */
324 /* if there's no link, we don't get this far and the LED is off */
325  
326 /* OFF -> ON always */
327 /* ON -> OFF on activity */
328 if (trigger_data->led_cdev->brightness == LED_OFF) {
329 led_set_brightness(trigger_data->led_cdev, LED_FULL);
330 } else if (trigger_data->last_activity != new_activity) {
331 led_set_brightness(trigger_data->led_cdev, LED_OFF);
332 }
333 } else {
334 /* base state is OFF */
335 /* ON -> OFF always */
336 /* OFF -> ON on activity */
337 if (trigger_data->led_cdev->brightness == LED_FULL) {
338 led_set_brightness(trigger_data->led_cdev, LED_OFF);
339 } else if (trigger_data->last_activity != new_activity) {
340 led_set_brightness(trigger_data->led_cdev, LED_FULL);
341 }
342 }
343  
344 trigger_data->last_activity = new_activity;
345 schedule_delayed_work(&trigger_data->work, trigger_data->interval);
346 }
347  
348 static void netdev_trig_activate(struct led_classdev *led_cdev)
349 {
350 struct led_netdev_data *trigger_data;
351 int rc;
352  
353 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
354 if (!trigger_data)
355 return;
356  
357 spin_lock_init(&trigger_data->lock);
358  
359 trigger_data->notifier.notifier_call = netdev_trig_notify;
360 trigger_data->notifier.priority = 10;
361  
362 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
363  
364 trigger_data->led_cdev = led_cdev;
365 trigger_data->net_dev = NULL;
366 trigger_data->device_name[0] = 0;
367  
368 trigger_data->mode = 0;
369 trigger_data->interval = msecs_to_jiffies(50);
370 trigger_data->link_up = 0;
371 trigger_data->last_activity = 0;
372  
373 led_cdev->trigger_data = trigger_data;
374  
375 rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
376 if (rc)
377 goto err_out;
378 rc = device_create_file(led_cdev->dev, &dev_attr_mode);
379 if (rc)
380 goto err_out_device_name;
381 rc = device_create_file(led_cdev->dev, &dev_attr_interval);
382 if (rc)
383 goto err_out_mode;
384  
385 register_netdevice_notifier(&trigger_data->notifier);
386 return;
387  
388 err_out_mode:
389 device_remove_file(led_cdev->dev, &dev_attr_mode);
390 err_out_device_name:
391 device_remove_file(led_cdev->dev, &dev_attr_device_name);
392 err_out:
393 led_cdev->trigger_data = NULL;
394 kfree(trigger_data);
395 }
396  
397 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
398 {
399 struct led_netdev_data *trigger_data = led_cdev->trigger_data;
400  
401 if (trigger_data) {
402 unregister_netdevice_notifier(&trigger_data->notifier);
403  
404 device_remove_file(led_cdev->dev, &dev_attr_device_name);
405 device_remove_file(led_cdev->dev, &dev_attr_mode);
406 device_remove_file(led_cdev->dev, &dev_attr_interval);
407  
408 cancel_delayed_work_sync(&trigger_data->work);
409  
410 spin_lock_bh(&trigger_data->lock);
411  
412 if (trigger_data->net_dev) {
413 dev_put(trigger_data->net_dev);
414 trigger_data->net_dev = NULL;
415 }
416  
417 spin_unlock_bh(&trigger_data->lock);
418  
419 kfree(trigger_data);
420 }
421 }
422  
423 static struct led_trigger netdev_led_trigger = {
424 .name = "netdev",
425 .activate = netdev_trig_activate,
426 .deactivate = netdev_trig_deactivate,
427 };
428  
429 static int __init netdev_trig_init(void)
430 {
431 return led_trigger_register(&netdev_led_trigger);
432 }
433  
434 static void __exit netdev_trig_exit(void)
435 {
436 led_trigger_unregister(&netdev_led_trigger);
437 }
438  
439 module_init(netdev_trig_init);
440 module_exit(netdev_trig_exit);
441  
442 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
443 MODULE_DESCRIPTION("Netdev LED trigger");
444 MODULE_LICENSE("GPL");