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 && 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");