drivers/leds/trigger/ledtrig-netdev.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright 2017 Ben Whitten <ben.whitten@gmail.com>
   3 // Copyright 2007 Oliver Jowett <oliver@opencloud.com>
   4 //
   5 // LED Kernel Netdev Trigger
   6 //
   7 // Toggles the LED to reflect the link and traffic state of a named net device
   8 //
   9 // Derived from ledtrig-timer.c which is:
  10 //  Copyright 2005-2006 Openedhand Ltd.
  11 //  Author: Richard Purdie <rpurdie@openedhand.com>
  12
  13 #include <linux/atomic.h>
  14 #include <linux/ctype.h>
  15 #include <linux/device.h>
  16 #include <linux/init.h>
  17 #include <linux/jiffies.h>
  18 #include <linux/kernel.h>
  19 #include <linux/leds.h>
  20 #include <linux/list.h>
  21 #include <linux/module.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/timer.h>
  25 #include "../leds.h"
  26
  27 /*
  28  * Configurable sysfs attributes:
  29  *
  30  * device_name - network device name to monitor
  31  * interval - duration of LED blink, in milliseconds
  32  * link -  LED's normal state reflects whether the link is up
  33  *         (has carrier) or not
  34  * tx -  LED blinks on transmitted data
  35  * rx -  LED blinks on receive data
  36  *
  37  */
  38
  39 struct led_netdev_data {
  40         spinlock_t lock;
  41
  42         struct delayed_work work;
  43         struct notifier_block notifier;
  44
  45         struct led_classdev *led_cdev;
  46         struct net_device *net_dev;
  47
  48         char device_name[IFNAMSIZ];
  49         atomic_t interval;
  50         unsigned int last_activity;
  51
  52         unsigned long mode;
  53 #define NETDEV_LED_LINK 0
  54 #define NETDEV_LED_TX   1
  55 #define NETDEV_LED_RX   2
  56 #define NETDEV_LED_MODE_LINKUP  3
  57 };
  58
  59 enum netdev_led_attr {
  60         NETDEV_ATTR_LINK,
  61         NETDEV_ATTR_TX,
  62         NETDEV_ATTR_RX
  63 };
  64
  65 static void set_baseline_state(struct led_netdev_data *trigger_data)
  66 {
  67         int current_brightness;
  68         struct led_classdev *led_cdev = trigger_data->led_cdev;
  69
  70         current_brightness = led_cdev->brightness;
  71         if (current_brightness)
  72                 led_cdev->blink_brightness = current_brightness;
  73         if (!led_cdev->blink_brightness)
  74                 led_cdev->blink_brightness = led_cdev->max_brightness;
  75
  76         if (!test_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode))
  77                 led_set_brightness(led_cdev, LED_OFF);
  78         else {
  79                 if (test_bit(NETDEV_LED_LINK, &trigger_data->mode))
  80                         led_set_brightness(led_cdev,
  81                                            led_cdev->blink_brightness);
  82                 else
  83                         led_set_brightness(led_cdev, LED_OFF);
  84
  85                 /* If we are looking for RX/TX start periodically
  86                  * checking stats
  87                  */
  88                 if (test_bit(NETDEV_LED_TX, &trigger_data->mode) ||
  89                     test_bit(NETDEV_LED_RX, &trigger_data->mode))
  90                         schedule_delayed_work(&trigger_data->work, 0);
  91         }
  92 }
  93
  94 static ssize_t device_name_show(struct device *dev,
  95                                 struct device_attribute *attr, char *buf)
  96 {
  97         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
  98         ssize_t len;
  99
 100         spin_lock_bh(&trigger_data->lock);
 101         len = sprintf(buf, "%s\n", trigger_data->device_name);
 102         spin_unlock_bh(&trigger_data->lock);
 103
 104         return len;
 105 }
 106
 107 static ssize_t device_name_store(struct device *dev,
 108                                  struct device_attribute *attr, const char *buf,
 109                                  size_t size)
 110 {
 111         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 112
 113         if (size >= IFNAMSIZ)
 114                 return -EINVAL;
 115
 116         cancel_delayed_work_sync(&trigger_data->work);
 117
 118         spin_lock_bh(&trigger_data->lock);
 119
 120         if (trigger_data->net_dev) {
 121                 dev_put(trigger_data->net_dev);
 122                 trigger_data->net_dev = NULL;
 123         }
 124
 125         strncpy(trigger_data->device_name, buf, size);
 126         if (size > 0 && trigger_data->device_name[size - 1] == '\n')
 127                 trigger_data->device_name[size - 1] = 0;
 128
 129         if (trigger_data->device_name[0] != 0)
 130                 trigger_data->net_dev =
 131                     dev_get_by_name(&init_net, trigger_data->device_name);
 132
 133         clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 134         if (trigger_data->net_dev != NULL)
 135                 if (netif_carrier_ok(trigger_data->net_dev))
 136                         set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 137
 138         trigger_data->last_activity = 0;
 139
 140         set_baseline_state(trigger_data);
 141         spin_unlock_bh(&trigger_data->lock);
 142
 143         return size;
 144 }
 145
 146 static DEVICE_ATTR_RW(device_name);
 147
 148 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
 149         enum netdev_led_attr attr)
 150 {
 151         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 152         int bit;
 153
 154         switch (attr) {
 155         case NETDEV_ATTR_LINK:
 156                 bit = NETDEV_LED_LINK;
 157                 break;
 158         case NETDEV_ATTR_TX:
 159                 bit = NETDEV_LED_TX;
 160                 break;
 161         case NETDEV_ATTR_RX:
 162                 bit = NETDEV_LED_RX;
 163                 break;
 164         default:
 165                 return -EINVAL;
 166         }
 167
 168         return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
 169 }
 170
 171 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
 172         size_t size, enum netdev_led_attr attr)
 173 {
 174         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 175         unsigned long state;
 176         int ret;
 177         int bit;
 178
 179         ret = kstrtoul(buf, 0, &state);
 180         if (ret)
 181                 return ret;
 182
 183         switch (attr) {
 184         case NETDEV_ATTR_LINK:
 185                 bit = NETDEV_LED_LINK;
 186                 break;
 187         case NETDEV_ATTR_TX:
 188                 bit = NETDEV_LED_TX;
 189                 break;
 190         case NETDEV_ATTR_RX:
 191                 bit = NETDEV_LED_RX;
 192                 break;
 193         default:
 194                 return -EINVAL;
 195         }
 196
 197         cancel_delayed_work_sync(&trigger_data->work);
 198
 199         if (state)
 200                 set_bit(bit, &trigger_data->mode);
 201         else
 202                 clear_bit(bit, &trigger_data->mode);
 203
 204         set_baseline_state(trigger_data);
 205
 206         return size;
 207 }
 208
 209 static ssize_t link_show(struct device *dev,
 210         struct device_attribute *attr, char *buf)
 211 {
 212         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_LINK);
 213 }
 214
 215 static ssize_t link_store(struct device *dev,
 216         struct device_attribute *attr, const char *buf, size_t size)
 217 {
 218         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_LINK);
 219 }
 220
 221 static DEVICE_ATTR_RW(link);
 222
 223 static ssize_t tx_show(struct device *dev,
 224         struct device_attribute *attr, char *buf)
 225 {
 226         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_TX);
 227 }
 228
 229 static ssize_t tx_store(struct device *dev,
 230         struct device_attribute *attr, const char *buf, size_t size)
 231 {
 232         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_TX);
 233 }
 234
 235 static DEVICE_ATTR_RW(tx);
 236
 237 static ssize_t rx_show(struct device *dev,
 238         struct device_attribute *attr, char *buf)
 239 {
 240         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_RX);
 241 }
 242
 243 static ssize_t rx_store(struct device *dev,
 244         struct device_attribute *attr, const char *buf, size_t size)
 245 {
 246         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_RX);
 247 }
 248
 249 static DEVICE_ATTR_RW(rx);
 250
 251 static ssize_t interval_show(struct device *dev,
 252                              struct device_attribute *attr, char *buf)
 253 {
 254         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 255
 256         return sprintf(buf, "%u\n",
 257                        jiffies_to_msecs(atomic_read(&trigger_data->interval)));
 258 }
 259
 260 static ssize_t interval_store(struct device *dev,
 261                               struct device_attribute *attr, const char *buf,
 262                               size_t size)
 263 {
 264         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 265         unsigned long value;
 266         int ret;
 267
 268         ret = kstrtoul(buf, 0, &value);
 269         if (ret)
 270                 return ret;
 271
 272         /* impose some basic bounds on the timer interval */
 273         if (value >= 5 && value <= 10000) {
 274                 cancel_delayed_work_sync(&trigger_data->work);
 275
 276                 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
 277                 set_baseline_state(trigger_data);       /* resets timer */
 278         }
 279
 280         return size;
 281 }
 282
 283 static DEVICE_ATTR_RW(interval);
 284
 285 static struct attribute *netdev_trig_attrs[] = {
 286         &dev_attr_device_name.attr,
 287         &dev_attr_link.attr,
 288         &dev_attr_rx.attr,
 289         &dev_attr_tx.attr,
 290         &dev_attr_interval.attr,
 291         NULL
 292 };
 293 ATTRIBUTE_GROUPS(netdev_trig);
 294
 295 static int netdev_trig_notify(struct notifier_block *nb,
 296                               unsigned long evt, void *dv)
 297 {
 298         struct net_device *dev =
 299                 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
 300         struct led_netdev_data *trigger_data =
 301                 container_of(nb, struct led_netdev_data, notifier);
 302
 303         if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
 304             && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
 305             && evt != NETDEV_CHANGENAME)
 306                 return NOTIFY_DONE;
 307
 308         if (strcmp(dev->name, trigger_data->device_name))
 309                 return NOTIFY_DONE;
 310
 311         cancel_delayed_work_sync(&trigger_data->work);
 312
 313         spin_lock_bh(&trigger_data->lock);
 314
 315         clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 316         switch (evt) {
 317         case NETDEV_REGISTER:
 318                 if (trigger_data->net_dev)
 319                         dev_put(trigger_data->net_dev);
 320                 dev_hold(dev);
 321                 trigger_data->net_dev = dev;
 322                 break;
 323         case NETDEV_CHANGENAME:
 324         case NETDEV_UNREGISTER:
 325                 if (trigger_data->net_dev) {
 326                         dev_put(trigger_data->net_dev);
 327                         trigger_data->net_dev = NULL;
 328                 }
 329                 break;
 330         case NETDEV_UP:
 331         case NETDEV_CHANGE:
 332                 if (netif_carrier_ok(dev))
 333                         set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 334                 break;
 335         }
 336
 337         set_baseline_state(trigger_data);
 338
 339         spin_unlock_bh(&trigger_data->lock);
 340
 341         return NOTIFY_DONE;
 342 }
 343
 344 /* here's the real work! */
 345 static void netdev_trig_work(struct work_struct *work)
 346 {
 347         struct led_netdev_data *trigger_data =
 348                 container_of(work, struct led_netdev_data, work.work);
 349         struct rtnl_link_stats64 *dev_stats;
 350         unsigned int new_activity;
 351         struct rtnl_link_stats64 temp;
 352         unsigned long interval;
 353         int invert;
 354
 355         /* If we dont have a device, insure we are off */
 356         if (!trigger_data->net_dev) {
 357                 led_set_brightness(trigger_data->led_cdev, LED_OFF);
 358                 return;
 359         }
 360
 361         /* If we are not looking for RX/TX then return  */
 362         if (!test_bit(NETDEV_LED_TX, &trigger_data->mode) &&
 363             !test_bit(NETDEV_LED_RX, &trigger_data->mode))
 364                 return;
 365
 366         dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
 367         new_activity =
 368             (test_bit(NETDEV_LED_TX, &trigger_data->mode) ?
 369                 dev_stats->tx_packets : 0) +
 370             (test_bit(NETDEV_LED_RX, &trigger_data->mode) ?
 371                 dev_stats->rx_packets : 0);
 372
 373         if (trigger_data->last_activity != new_activity) {
 374                 led_stop_software_blink(trigger_data->led_cdev);
 375
 376                 invert = test_bit(NETDEV_LED_LINK, &trigger_data->mode);
 377                 interval = jiffies_to_msecs(
 378                                 atomic_read(&trigger_data->interval));
 379                 /* base state is ON (link present) */
 380                 led_blink_set_oneshot(trigger_data->led_cdev,
 381                                       &interval,
 382                                       &interval,
 383                                       invert);
 384                 trigger_data->last_activity = new_activity;
 385         }
 386
 387         schedule_delayed_work(&trigger_data->work,
 388                         (atomic_read(&trigger_data->interval)*2));
 389 }
 390
 391 static int netdev_trig_activate(struct led_classdev *led_cdev)
 392 {
 393         struct led_netdev_data *trigger_data;
 394         int rc;
 395
 396         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 397         if (!trigger_data)
 398                 return -ENOMEM;
 399
 400         spin_lock_init(&trigger_data->lock);
 401
 402         trigger_data->notifier.notifier_call = netdev_trig_notify;
 403         trigger_data->notifier.priority = 10;
 404
 405         INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
 406
 407         trigger_data->led_cdev = led_cdev;
 408         trigger_data->net_dev = NULL;
 409         trigger_data->device_name[0] = 0;
 410
 411         trigger_data->mode = 0;
 412         atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
 413         trigger_data->last_activity = 0;
 414
 415         led_set_trigger_data(led_cdev, trigger_data);
 416
 417         rc = register_netdevice_notifier(&trigger_data->notifier);
 418         if (rc)
 419                 kfree(trigger_data);
 420
 421         return rc;
 422 }
 423
 424 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 425 {
 426         struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
 427
 428         unregister_netdevice_notifier(&trigger_data->notifier);
 429
 430         cancel_delayed_work_sync(&trigger_data->work);
 431
 432         if (trigger_data->net_dev)
 433                 dev_put(trigger_data->net_dev);
 434
 435         kfree(trigger_data);
 436 }
 437
 438 static struct led_trigger netdev_led_trigger = {
 439         .name = "netdev",
 440         .activate = netdev_trig_activate,
 441         .deactivate = netdev_trig_deactivate,
 442         .groups = netdev_trig_groups,
 443 };
 444
 445 static int __init netdev_trig_init(void)
 446 {
 447         return led_trigger_register(&netdev_led_trigger);
 448 }
 449
 450 static void __exit netdev_trig_exit(void)
 451 {
 452         led_trigger_unregister(&netdev_led_trigger);
 453 }
 454
 455 module_init(netdev_trig_init);
 456 module_exit(netdev_trig_exit);
 457
 458 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
 459 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
 460 MODULE_DESCRIPTION("Netdev LED trigger");
 461 MODULE_LICENSE("GPL v2");