target/linux/generic/files/drivers/leds/ledtrig-netdev.c

   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 timer_list timer;
  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                 mod_timer(&trigger_data->timer, jiffies + 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 < 0 || size >= IFNAMSIZ)
 117                 return -EINVAL;
 118
 119         spin_lock_bh(&trigger_data->lock);
 120         del_timer_sync(&trigger_data->timer);
 121
 122         strcpy(trigger_data->device_name, buf);
 123         if (size > 0 && trigger_data->device_name[size-1] == '\n')
 124                 trigger_data->device_name[size-1] = 0;
 125         trigger_data->link_up = 0;
 126         trigger_data->last_activity = 0;
 127
 128         if (trigger_data->device_name[0] != 0) {
 129                 /* check for existing device to update from */
 130                 trigger_data->net_dev = dev_get_by_name(&init_net, trigger_data->device_name);
 131                 if (trigger_data->net_dev != NULL)
 132                         trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
 133         }
 134
 135         set_baseline_state(trigger_data);
 136         spin_unlock_bh(&trigger_data->lock);
 137
 138         return size;
 139 }
 140
 141 static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);
 142
 143 static ssize_t led_mode_show(struct device *dev,
 144                 struct device_attribute *attr, char *buf)
 145 {
 146         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 147         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 148
 149         spin_lock_bh(&trigger_data->lock);
 150
 151         if (trigger_data->mode == 0) {
 152                 strcpy(buf, "none\n");
 153         } else {
 154                 if (trigger_data->mode & MODE_LINK)
 155                         strcat(buf, "link ");
 156                 if (trigger_data->mode & MODE_TX)
 157                         strcat(buf, "tx ");
 158                 if (trigger_data->mode & MODE_RX)
 159                         strcat(buf, "rx ");
 160                 strcat(buf, "\n");
 161         }
 162
 163         spin_unlock_bh(&trigger_data->lock);
 164
 165         return strlen(buf)+1;
 166 }
 167
 168 static ssize_t led_mode_store(struct device *dev,
 169                 struct device_attribute *attr, const char *buf, size_t size)
 170 {
 171         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 172         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 173         char copybuf[128];
 174         int new_mode = -1;
 175         char *p, *token;
 176
 177         /* take a copy since we don't want to trash the inbound buffer when using strsep */
 178         strncpy(copybuf, buf, sizeof(copybuf));
 179         copybuf[sizeof(copybuf) - 1] = 0;
 180         p = copybuf;
 181
 182         while ((token = strsep(&p, " \t\n")) != NULL) {
 183                 if (!*token)
 184                         continue;
 185
 186                 if (new_mode == -1)
 187                         new_mode = 0;
 188
 189                 if (!strcmp(token, "none"))
 190                         new_mode = 0;
 191                 else if (!strcmp(token, "tx"))
 192                         new_mode |= MODE_TX;
 193                 else if (!strcmp(token, "rx"))
 194                         new_mode |= MODE_RX;
 195                 else if (!strcmp(token, "link"))
 196                         new_mode |= MODE_LINK;
 197                 else
 198                         return -EINVAL;
 199         }
 200
 201         if (new_mode == -1)
 202                 return -EINVAL;
 203
 204         spin_lock_bh(&trigger_data->lock);
 205         del_timer_sync(&trigger_data->timer);
 206
 207         trigger_data->mode = new_mode;
 208
 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                 spin_lock_bh(&trigger_data->lock);
 246                 del_timer_sync(&trigger_data->timer);
 247
 248                 trigger_data->interval = msecs_to_jiffies(value);
 249
 250                 set_baseline_state(trigger_data); /* resets timer */
 251                 spin_unlock_bh(&trigger_data->lock);
 252
 253                 ret = count;
 254         }
 255
 256         return ret;
 257 }
 258
 259 static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
 260
 261 static int netdev_trig_notify(struct notifier_block *nb,
 262                               unsigned long evt,
 263                               void *dv)
 264 {
 265         struct net_device *dev = netdev_notifier_info_to_dev((struct netdev_notifier_info *) dv);
 266         struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
 267
 268         if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER && evt != NETDEV_CHANGENAME)
 269                 return NOTIFY_DONE;
 270
 271         spin_lock_bh(&trigger_data->lock);
 272
 273         if (strcmp(dev->name, trigger_data->device_name))
 274                 goto done;
 275
 276         del_timer_sync(&trigger_data->timer);
 277
 278         if (evt == NETDEV_REGISTER || evt == NETDEV_CHANGENAME) {
 279                 if (trigger_data->net_dev != NULL)
 280                         dev_put(trigger_data->net_dev);
 281
 282                 dev_hold(dev);
 283                 trigger_data->net_dev = dev;
 284                 trigger_data->link_up = 0;
 285                 goto done;
 286         }
 287
 288         if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
 289                 dev_put(trigger_data->net_dev);
 290                 trigger_data->net_dev = NULL;
 291                 goto done;
 292         }
 293
 294         /* UP / DOWN / CHANGE */
 295
 296         trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
 297         set_baseline_state(trigger_data);
 298
 299 done:
 300         spin_unlock_bh(&trigger_data->lock);
 301         return NOTIFY_DONE;
 302 }
 303
 304 /* here's the real work! */
 305 static void netdev_trig_timer(unsigned long arg)
 306 {
 307         struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg;
 308         struct rtnl_link_stats64 *dev_stats;
 309         unsigned new_activity;
 310         struct rtnl_link_stats64 temp;
 311
 312         if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
 313                 /* we don't need to do timer work, just reflect link state. */
 314                 led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
 315                 return;
 316         }
 317
 318         dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
 319         new_activity =
 320                 ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
 321                 ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
 322
 323         if (trigger_data->mode & MODE_LINK) {
 324                 /* base state is ON (link present) */
 325                 /* if there's no link, we don't get this far and the LED is off */
 326
 327                 /* OFF -> ON always */
 328                 /* ON -> OFF on activity */
 329                 if (trigger_data->led_cdev->brightness == LED_OFF) {
 330                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 331                 } else if (trigger_data->last_activity != new_activity) {
 332                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 333                 }
 334         } else {
 335                 /* base state is OFF */
 336                 /* ON -> OFF always */
 337                 /* OFF -> ON on activity */
 338                 if (trigger_data->led_cdev->brightness == LED_FULL) {
 339                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 340                 } else if (trigger_data->last_activity != new_activity) {
 341                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 342                 }
 343         }
 344
 345         trigger_data->last_activity = new_activity;
 346         mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
 347 }
 348
 349 static void netdev_trig_activate(struct led_classdev *led_cdev)
 350 {
 351         struct led_netdev_data *trigger_data;
 352         int rc;
 353
 354         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 355         if (!trigger_data)
 356                 return;
 357
 358         spin_lock_init(&trigger_data->lock);
 359
 360         trigger_data->notifier.notifier_call = netdev_trig_notify;
 361         trigger_data->notifier.priority = 10;
 362
 363         setup_timer(&trigger_data->timer, netdev_trig_timer, (unsigned long) trigger_data);
 364
 365         trigger_data->led_cdev = led_cdev;
 366         trigger_data->net_dev = NULL;
 367         trigger_data->device_name[0] = 0;
 368
 369         trigger_data->mode = 0;
 370         trigger_data->interval = msecs_to_jiffies(50);
 371         trigger_data->link_up = 0;
 372         trigger_data->last_activity = 0;
 373
 374         led_cdev->trigger_data = trigger_data;
 375
 376         rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
 377         if (rc)
 378                 goto err_out;
 379         rc = device_create_file(led_cdev->dev, &dev_attr_mode);
 380         if (rc)
 381                 goto err_out_device_name;
 382         rc = device_create_file(led_cdev->dev, &dev_attr_interval);
 383         if (rc)
 384                 goto err_out_mode;
 385
 386         register_netdevice_notifier(&trigger_data->notifier);
 387         return;
 388
 389 err_out_mode:
 390         device_remove_file(led_cdev->dev, &dev_attr_mode);
 391 err_out_device_name:
 392         device_remove_file(led_cdev->dev, &dev_attr_device_name);
 393 err_out:
 394         led_cdev->trigger_data = NULL;
 395         kfree(trigger_data);
 396 }
 397
 398 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 399 {
 400         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 401
 402         if (trigger_data) {
 403                 unregister_netdevice_notifier(&trigger_data->notifier);
 404
 405                 device_remove_file(led_cdev->dev, &dev_attr_device_name);
 406                 device_remove_file(led_cdev->dev, &dev_attr_mode);
 407                 device_remove_file(led_cdev->dev, &dev_attr_interval);
 408
 409                 spin_lock_bh(&trigger_data->lock);
 410                 del_timer_sync(&trigger_data->timer);
 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");