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