source: trunk/target/linux/generic/files/drivers/leds/ledtrig-netdev.c @ 27143

Last change on this file since 27143 was 27143, checked in by blogic, 5 years ago

[ledtrig-netdev]
we dont need 1024 bytes buffer. 128 bytes is enough.

File size: 12.0 KB
Line 
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/sysdev.h>
26#include <linux/netdevice.h>
27#include <linux/timer.h>
28#include <linux/ctype.h>
29#include <linux/leds.h>
30#include <linux/version.h>
31
32#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
33#include <net/net_namespace.h>
34#endif
35
36#include "leds.h"
37
38/*
39 * Configurable sysfs attributes:
40 *
41 * device_name - network device name to monitor
42 *
43 * interval - duration of LED blink, in milliseconds
44 *
45 * mode - either "none" (LED is off) or a space separated list of one or more of:
46 *   link: LED's normal state reflects whether the link is up (has carrier) or not
47 *   tx:   LED blinks on transmitted data
48 *   rx:   LED blinks on receive data
49 *
50 * Some suggestions:
51 *
52 *  Simple link status LED:
53 *  $ echo netdev >someled/trigger
54 *  $ echo eth0 >someled/device_name
55 *  $ echo link >someled/mode
56 *
57 *  Ethernet-style link/activity LED:
58 *  $ echo netdev >someled/trigger
59 *  $ echo eth0 >someled/device_name
60 *  $ echo "link tx rx" >someled/mode
61 *
62 *  Modem-style tx/rx LEDs:
63 *  $ echo netdev >led1/trigger
64 *  $ echo ppp0 >led1/device_name
65 *  $ echo tx >led1/mode
66 *  $ echo netdev >led2/trigger
67 *  $ echo ppp0 >led2/device_name
68 *  $ echo rx >led2/mode
69 *
70 */
71
72#define MODE_LINK 1
73#define MODE_TX   2
74#define MODE_RX   4
75
76struct led_netdev_data {
77        rwlock_t lock;
78
79        struct timer_list timer;
80        struct notifier_block notifier;
81
82        struct led_classdev *led_cdev;
83        struct net_device *net_dev;
84
85        char device_name[IFNAMSIZ];
86        unsigned interval;
87        unsigned mode;
88        unsigned link_up;
89        unsigned last_activity;
90};
91
92static void set_baseline_state(struct led_netdev_data *trigger_data)
93{
94        if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
95                led_set_brightness(trigger_data->led_cdev, LED_FULL);
96        else
97                led_set_brightness(trigger_data->led_cdev, LED_OFF);
98
99        if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up)
100                mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
101        else
102                del_timer(&trigger_data->timer);
103}
104
105static ssize_t led_device_name_show(struct device *dev,
106                                    struct device_attribute *attr, char *buf)
107{
108        struct led_classdev *led_cdev = dev_get_drvdata(dev);
109        struct led_netdev_data *trigger_data = led_cdev->trigger_data;
110
111        read_lock(&trigger_data->lock);
112        sprintf(buf, "%s\n", trigger_data->device_name);
113        read_unlock(&trigger_data->lock);
114
115        return strlen(buf) + 1;
116}
117
118#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
119extern struct net init_net;
120#endif
121
122static ssize_t led_device_name_store(struct device *dev,
123                                     struct device_attribute *attr, const char *buf, size_t size)
124{
125        struct led_classdev *led_cdev = dev_get_drvdata(dev);
126        struct led_netdev_data *trigger_data = led_cdev->trigger_data;
127
128        if (size < 0 || size >= IFNAMSIZ)
129                return -EINVAL;
130
131        write_lock(&trigger_data->lock);
132
133        strcpy(trigger_data->device_name, buf);
134        if (size > 0 && trigger_data->device_name[size-1] == '\n')
135                trigger_data->device_name[size-1] = 0;
136
137        if (trigger_data->device_name[0] != 0) {
138                /* check for existing device to update from */
139#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
140                trigger_data->net_dev = dev_get_by_name(&init_net, trigger_data->device_name);
141#else
142                trigger_data->net_dev = dev_get_by_name(trigger_data->device_name);
143#endif
144                if (trigger_data->net_dev != NULL)
145                        trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
146                set_baseline_state(trigger_data); /* updates LEDs, may start timers */
147        }
148
149        write_unlock(&trigger_data->lock);
150        return size;
151}
152
153static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);
154
155static ssize_t led_mode_show(struct device *dev,
156                             struct device_attribute *attr, char *buf)
157{
158        struct led_classdev *led_cdev = dev_get_drvdata(dev);
159        struct led_netdev_data *trigger_data = led_cdev->trigger_data;
160
161        read_lock(&trigger_data->lock);
162
163        if (trigger_data->mode == 0) {
164                strcpy(buf, "none\n");
165        } else {
166                if (trigger_data->mode & MODE_LINK)
167                        strcat(buf, "link ");
168                if (trigger_data->mode & MODE_TX)
169                        strcat(buf, "tx ");
170                if (trigger_data->mode & MODE_RX)
171                        strcat(buf, "rx ");
172                strcat(buf, "\n");
173        }
174
175        read_unlock(&trigger_data->lock);
176
177        return strlen(buf)+1;
178}
179
180static ssize_t led_mode_store(struct device *dev,
181                              struct device_attribute *attr, const char *buf, size_t size)
182{
183        struct led_classdev *led_cdev = dev_get_drvdata(dev);
184        struct led_netdev_data *trigger_data = led_cdev->trigger_data;
185        char copybuf[128];
186        int new_mode = -1;
187        char *p, *token;
188
189        /* take a copy since we don't want to trash the inbound buffer when using strsep */
190        strncpy(copybuf, buf, sizeof(copybuf));
191        copybuf[sizeof(copybuf) - 1] = 0;
192        p = copybuf;
193
194        while ((token = strsep(&p, " \t\n")) != NULL) {
195                if (!*token)
196                        continue;
197
198                if (new_mode == -1)
199                        new_mode = 0;
200
201                if (!strcmp(token, "none"))
202                        new_mode = 0;
203                else if (!strcmp(token, "tx"))
204                        new_mode |= MODE_TX;
205                else if (!strcmp(token, "rx"))
206                        new_mode |= MODE_RX;
207                else if (!strcmp(token, "link"))
208                        new_mode |= MODE_LINK;
209                else
210                        return -EINVAL;
211        }
212
213        if (new_mode == -1)
214                return -EINVAL;
215
216        write_lock(&trigger_data->lock);
217        trigger_data->mode = new_mode;
218        set_baseline_state(trigger_data);
219        write_unlock(&trigger_data->lock);
220
221        return size;
222}
223
224static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);
225
226static ssize_t led_interval_show(struct device *dev,
227                                 struct device_attribute *attr, char *buf)
228{
229        struct led_classdev *led_cdev = dev_get_drvdata(dev);
230        struct led_netdev_data *trigger_data = led_cdev->trigger_data;
231
232        read_lock(&trigger_data->lock);
233        sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
234        read_unlock(&trigger_data->lock);
235
236        return strlen(buf) + 1;
237}
238
239static ssize_t led_interval_store(struct device *dev,
240                                  struct device_attribute *attr, const char *buf, size_t size)
241{
242        struct led_classdev *led_cdev = dev_get_drvdata(dev);
243        struct led_netdev_data *trigger_data = led_cdev->trigger_data;
244        int ret = -EINVAL;
245        char *after;
246        unsigned long value = simple_strtoul(buf, &after, 10);
247        size_t count = after - buf;
248
249        if (*after && isspace(*after))
250                count++;
251
252        /* impose some basic bounds on the timer interval */
253        if (count == size && value >= 5 && value <= 10000) {
254                write_lock(&trigger_data->lock);
255                trigger_data->interval = msecs_to_jiffies(value);
256                set_baseline_state(trigger_data); // resets timer
257                write_unlock(&trigger_data->lock);
258                ret = count;
259        }
260
261        return ret;
262}
263
264static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
265
266static int netdev_trig_notify(struct notifier_block *nb,
267                              unsigned long evt,
268                              void *dv)
269{
270        struct net_device *dev = dv;
271        struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
272
273        if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER)
274                return NOTIFY_DONE;
275
276        write_lock(&trigger_data->lock);
277
278        if (strcmp(dev->name, trigger_data->device_name))
279                goto done;
280
281        if (evt == NETDEV_REGISTER) {
282                if (trigger_data->net_dev != NULL)
283                        dev_put(trigger_data->net_dev);
284                dev_hold(dev);
285                trigger_data->net_dev = dev;
286                trigger_data->link_up = 0;
287                goto done;
288        }
289
290        if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
291                dev_put(trigger_data->net_dev);
292                trigger_data->net_dev = NULL;
293                goto done;
294        }
295
296        /* UP / DOWN / CHANGE */
297
298        trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
299        set_baseline_state(trigger_data);
300
301done:
302        write_unlock(&trigger_data->lock);
303        return NOTIFY_DONE;
304}
305
306/* here's the real work! */
307static void netdev_trig_timer(unsigned long arg)
308{
309        struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg;
310        const struct net_device_stats *dev_stats;
311        unsigned new_activity;
312
313        write_lock(&trigger_data->lock);
314
315        if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
316                /* we don't need to do timer work, just reflect link state. */
317                led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
318                goto no_restart;
319        }
320
321        dev_stats = dev_get_stats(trigger_data->net_dev);
322        new_activity =
323                ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
324                ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
325
326        if (trigger_data->mode & MODE_LINK) {
327                /* base state is ON (link present) */
328                /* if there's no link, we don't get this far and the LED is off */
329
330                /* OFF -> ON always */
331                /* ON -> OFF on activity */
332                if (trigger_data->led_cdev->brightness == LED_OFF) {
333                        led_set_brightness(trigger_data->led_cdev, LED_FULL);
334                } else if (trigger_data->last_activity != new_activity) {
335                        led_set_brightness(trigger_data->led_cdev, LED_OFF);
336                }
337        } else {
338                /* base state is OFF */
339                /* ON -> OFF always */
340                /* OFF -> ON on activity */
341                if (trigger_data->led_cdev->brightness == LED_FULL) {
342                        led_set_brightness(trigger_data->led_cdev, LED_OFF);
343                } else if (trigger_data->last_activity != new_activity) {
344                        led_set_brightness(trigger_data->led_cdev, LED_FULL);
345                }
346        }
347
348        trigger_data->last_activity = new_activity;
349        mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
350
351no_restart:
352        write_unlock(&trigger_data->lock);
353}
354
355static void netdev_trig_activate(struct led_classdev *led_cdev)
356{
357        struct led_netdev_data *trigger_data;
358        int rc;
359
360        trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
361        if (!trigger_data)
362                return;
363
364        rwlock_init(&trigger_data->lock);
365
366        trigger_data->notifier.notifier_call = netdev_trig_notify;
367        trigger_data->notifier.priority = 10;
368
369        setup_timer(&trigger_data->timer, netdev_trig_timer, (unsigned long) trigger_data);
370
371        trigger_data->led_cdev = led_cdev;
372        trigger_data->net_dev = NULL;
373        trigger_data->device_name[0] = 0;
374
375        trigger_data->mode = 0;
376        trigger_data->interval = msecs_to_jiffies(50);
377        trigger_data->link_up = 0;
378        trigger_data->last_activity = 0;
379
380        led_cdev->trigger_data = trigger_data;
381
382        rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
383        if (rc)
384                goto err_out;
385        rc = device_create_file(led_cdev->dev, &dev_attr_mode);
386        if (rc)
387                goto err_out_device_name;
388        rc = device_create_file(led_cdev->dev, &dev_attr_interval);
389        if (rc)
390                goto err_out_mode;
391
392        register_netdevice_notifier(&trigger_data->notifier);
393        return;
394
395err_out_mode:
396        device_remove_file(led_cdev->dev, &dev_attr_mode);
397err_out_device_name:
398        device_remove_file(led_cdev->dev, &dev_attr_device_name);
399err_out:
400        led_cdev->trigger_data = NULL;
401        kfree(trigger_data);
402}
403
404static void netdev_trig_deactivate(struct led_classdev *led_cdev)
405{
406        struct led_netdev_data *trigger_data = led_cdev->trigger_data;
407
408        if (trigger_data) {
409                unregister_netdevice_notifier(&trigger_data->notifier);
410
411                device_remove_file(led_cdev->dev, &dev_attr_device_name);
412                device_remove_file(led_cdev->dev, &dev_attr_mode);
413                device_remove_file(led_cdev->dev, &dev_attr_interval);
414
415                write_lock(&trigger_data->lock);
416
417                if (trigger_data->net_dev) {
418                        dev_put(trigger_data->net_dev);
419                        trigger_data->net_dev = NULL;
420                }
421
422                write_unlock(&trigger_data->lock);
423
424                del_timer_sync(&trigger_data->timer);
425
426                kfree(trigger_data);
427        }
428}
429
430static struct led_trigger netdev_led_trigger = {
431        .name     = "netdev",
432        .activate = netdev_trig_activate,
433        .deactivate = netdev_trig_deactivate,
434};
435
436static int __init netdev_trig_init(void)
437{
438        return led_trigger_register(&netdev_led_trigger);
439}
440
441static void __exit netdev_trig_exit(void)
442{
443        led_trigger_unregister(&netdev_led_trigger);
444}
445
446module_init(netdev_trig_init);
447module_exit(netdev_trig_exit);
448
449MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
450MODULE_DESCRIPTION("Netdev LED trigger");
451MODULE_LICENSE("GPL");
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