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 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)
 268                 return NOTIFY_DONE;
 269
 270         if (!(dev == trigger_data->net_dev ||
 271               (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
 272                 return NOTIFY_DONE;
 273
 274         cancel_delayed_work_sync(&trigger_data->work);
 275
 276         spin_lock_bh(&trigger_data->lock);
 277
 278         switch (evt) {
 279         case NETDEV_REGISTER:
 280                 dev_hold(dev);
 281                 trigger_data->net_dev = dev;
 282                 trigger_data->link_up = 0;
 283                 break;
 284         case NETDEV_UNREGISTER:
 285                 dev_put(trigger_data->net_dev);
 286                 trigger_data->net_dev = NULL;
 287                 break;
 288         default: /* UP / DOWN / CHANGE */
 289                 trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
 290                 set_baseline_state(trigger_data);
 291                 break;
 292         }
 293
 294         spin_unlock_bh(&trigger_data->lock);
 295
 296         return NOTIFY_DONE;
 297 }
 298
 299 /* here's the real work! */
 300 static void netdev_trig_work(struct work_struct *work)
 301 {
 302         struct led_netdev_data *trigger_data = container_of(work, struct led_netdev_data, work.work);
 303         struct rtnl_link_stats64 *dev_stats;
 304         unsigned new_activity;
 305         struct rtnl_link_stats64 temp;
 306
 307         if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
 308                 /* we don't need to do timer work, just reflect link state. */
 309                 led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
 310                 return;
 311         }
 312
 313         dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
 314         new_activity =
 315                 ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
 316                 ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
 317
 318         if (trigger_data->mode & MODE_LINK) {
 319                 /* base state is ON (link present) */
 320                 /* if there's no link, we don't get this far and the LED is off */
 321
 322                 /* OFF -> ON always */
 323                 /* ON -> OFF on activity */
 324                 if (trigger_data->led_cdev->brightness == LED_OFF) {
 325                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 326                 } else if (trigger_data->last_activity != new_activity) {
 327                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 328                 }
 329         } else {
 330                 /* base state is OFF */
 331                 /* ON -> OFF always */
 332                 /* OFF -> ON on activity */
 333                 if (trigger_data->led_cdev->brightness == LED_FULL) {
 334                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 335                 } else if (trigger_data->last_activity != new_activity) {
 336                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 337                 }
 338         }
 339
 340         trigger_data->last_activity = new_activity;
 341         schedule_delayed_work(&trigger_data->work, trigger_data->interval);
 342 }
 343
 344 static void netdev_trig_activate(struct led_classdev *led_cdev)
 345 {
 346         struct led_netdev_data *trigger_data;
 347         int rc;
 348
 349         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 350         if (!trigger_data)
 351                 return;
 352
 353         spin_lock_init(&trigger_data->lock);
 354
 355         trigger_data->notifier.notifier_call = netdev_trig_notify;
 356         trigger_data->notifier.priority = 10;
 357
 358         INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
 359
 360         trigger_data->led_cdev = led_cdev;
 361         trigger_data->net_dev = NULL;
 362         trigger_data->device_name[0] = 0;
 363
 364         trigger_data->mode = 0;
 365         trigger_data->interval = msecs_to_jiffies(50);
 366         trigger_data->link_up = 0;
 367         trigger_data->last_activity = 0;
 368
 369         led_cdev->trigger_data = trigger_data;
 370
 371         rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
 372         if (rc)
 373                 goto err_out;
 374         rc = device_create_file(led_cdev->dev, &dev_attr_mode);
 375         if (rc)
 376                 goto err_out_device_name;
 377         rc = device_create_file(led_cdev->dev, &dev_attr_interval);
 378         if (rc)
 379                 goto err_out_mode;
 380
 381         register_netdevice_notifier(&trigger_data->notifier);
 382         return;
 383
 384 err_out_mode:
 385         device_remove_file(led_cdev->dev, &dev_attr_mode);
 386 err_out_device_name:
 387         device_remove_file(led_cdev->dev, &dev_attr_device_name);
 388 err_out:
 389         led_cdev->trigger_data = NULL;
 390         kfree(trigger_data);
 391 }
 392
 393 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 394 {
 395         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 396
 397         if (trigger_data) {
 398                 unregister_netdevice_notifier(&trigger_data->notifier);
 399
 400                 device_remove_file(led_cdev->dev, &dev_attr_device_name);
 401                 device_remove_file(led_cdev->dev, &dev_attr_mode);
 402                 device_remove_file(led_cdev->dev, &dev_attr_interval);
 403
 404                 cancel_delayed_work_sync(&trigger_data->work);
 405
 406                 spin_lock_bh(&trigger_data->lock);
 407
 408                 if (trigger_data->net_dev) {
 409                         dev_put(trigger_data->net_dev);
 410                         trigger_data->net_dev = NULL;
 411                 }
 412
 413                 spin_unlock_bh(&trigger_data->lock);
 414
 415                 kfree(trigger_data);
 416         }
 417 }
 418
 419 static struct led_trigger netdev_led_trigger = {
 420         .name     = "netdev",
 421         .activate = netdev_trig_activate,
 422         .deactivate = netdev_trig_deactivate,
 423 };
 424
 425 static int __init netdev_trig_init(void)
 426 {
 427         return led_trigger_register(&netdev_led_trigger);
 428 }
 429
 430 static void __exit netdev_trig_exit(void)
 431 {
 432         led_trigger_unregister(&netdev_led_trigger);
 433 }
 434
 435 module_init(netdev_trig_init);
 436 module_exit(netdev_trig_exit);
 437
 438 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
 439 MODULE_DESCRIPTION("Netdev LED trigger");
 440 MODULE_LICENSE("GPL");