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         memcpy(trigger_data->device_name, buf, size);
 126         trigger_data->device_name[size] = 0;
 127         if (size > 0 && trigger_data->device_name[size - 1] == '\n')
 128                 trigger_data->device_name[size - 1] = 0;
 129
 130         if (trigger_data->device_name[0] != 0)
 131                 trigger_data->net_dev =
 132                     dev_get_by_name(&init_net, trigger_data->device_name);
 133
 134         clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 135         if (trigger_data->net_dev != NULL)
 136                 if (netif_carrier_ok(trigger_data->net_dev))
 137                         set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 138
 139         trigger_data->last_activity = 0;
 140
 141         set_baseline_state(trigger_data);
 142         spin_unlock_bh(&trigger_data->lock);
 143
 144         return size;
 145 }
 146
 147 static DEVICE_ATTR_RW(device_name);
 148
 149 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
 150         enum netdev_led_attr attr)
 151 {
 152         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 153         int bit;
 154
 155         switch (attr) {
 156         case NETDEV_ATTR_LINK:
 157                 bit = NETDEV_LED_LINK;
 158                 break;
 159         case NETDEV_ATTR_TX:
 160                 bit = NETDEV_LED_TX;
 161                 break;
 162         case NETDEV_ATTR_RX:
 163                 bit = NETDEV_LED_RX;
 164                 break;
 165         default:
 166                 return -EINVAL;
 167         }
 168
 169         return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
 170 }
 171
 172 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
 173         size_t size, enum netdev_led_attr attr)
 174 {
 175         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 176         unsigned long state;
 177         int ret;
 178         int bit;
 179
 180         ret = kstrtoul(buf, 0, &state);
 181         if (ret)
 182                 return ret;
 183
 184         switch (attr) {
 185         case NETDEV_ATTR_LINK:
 186                 bit = NETDEV_LED_LINK;
 187                 break;
 188         case NETDEV_ATTR_TX:
 189                 bit = NETDEV_LED_TX;
 190                 break;
 191         case NETDEV_ATTR_RX:
 192                 bit = NETDEV_LED_RX;
 193                 break;
 194         default:
 195                 return -EINVAL;
 196         }
 197
 198         cancel_delayed_work_sync(&trigger_data->work);
 199
 200         if (state)
 201                 set_bit(bit, &trigger_data->mode);
 202         else
 203                 clear_bit(bit, &trigger_data->mode);
 204
 205         set_baseline_state(trigger_data);
 206
 207         return size;
 208 }
 209
 210 static ssize_t link_show(struct device *dev,
 211         struct device_attribute *attr, char *buf)
 212 {
 213         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_LINK);
 214 }
 215
 216 static ssize_t link_store(struct device *dev,
 217         struct device_attribute *attr, const char *buf, size_t size)
 218 {
 219         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_LINK);
 220 }
 221
 222 static DEVICE_ATTR_RW(link);
 223
 224 static ssize_t tx_show(struct device *dev,
 225         struct device_attribute *attr, char *buf)
 226 {
 227         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_TX);
 228 }
 229
 230 static ssize_t tx_store(struct device *dev,
 231         struct device_attribute *attr, const char *buf, size_t size)
 232 {
 233         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_TX);
 234 }
 235
 236 static DEVICE_ATTR_RW(tx);
 237
 238 static ssize_t rx_show(struct device *dev,
 239         struct device_attribute *attr, char *buf)
 240 {
 241         return netdev_led_attr_show(dev, buf, NETDEV_ATTR_RX);
 242 }
 243
 244 static ssize_t rx_store(struct device *dev,
 245         struct device_attribute *attr, const char *buf, size_t size)
 246 {
 247         return netdev_led_attr_store(dev, buf, size, NETDEV_ATTR_RX);
 248 }
 249
 250 static DEVICE_ATTR_RW(rx);
 251
 252 static ssize_t interval_show(struct device *dev,
 253                              struct device_attribute *attr, char *buf)
 254 {
 255         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 256
 257         return sprintf(buf, "%u\n",
 258                        jiffies_to_msecs(atomic_read(&trigger_data->interval)));
 259 }
 260
 261 static ssize_t interval_store(struct device *dev,
 262                               struct device_attribute *attr, const char *buf,
 263                               size_t size)
 264 {
 265         struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 266         unsigned long value;
 267         int ret;
 268
 269         ret = kstrtoul(buf, 0, &value);
 270         if (ret)
 271                 return ret;
 272
 273         /* impose some basic bounds on the timer interval */
 274         if (value >= 5 && value <= 10000) {
 275                 cancel_delayed_work_sync(&trigger_data->work);
 276
 277                 atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
 278                 set_baseline_state(trigger_data);       /* resets timer */
 279         }
 280
 281         return size;
 282 }
 283
 284 static DEVICE_ATTR_RW(interval);
 285
 286 static struct attribute *netdev_trig_attrs[] = {
 287         &dev_attr_device_name.attr,
 288         &dev_attr_link.attr,
 289         &dev_attr_rx.attr,
 290         &dev_attr_tx.attr,
 291         &dev_attr_interval.attr,
 292         NULL
 293 };
 294 ATTRIBUTE_GROUPS(netdev_trig);
 295
 296 static int netdev_trig_notify(struct notifier_block *nb,
 297                               unsigned long evt, void *dv)
 298 {
 299         struct net_device *dev =
 300                 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
 301         struct led_netdev_data *trigger_data =
 302                 container_of(nb, struct led_netdev_data, notifier);
 303
 304         if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
 305             && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER)
 306                 return NOTIFY_DONE;
 307
 308         if (!(dev == trigger_data->net_dev ||
 309               (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
 310                 return NOTIFY_DONE;
 311
 312         cancel_delayed_work_sync(&trigger_data->work);
 313
 314         spin_lock_bh(&trigger_data->lock);
 315
 316         clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 317         switch (evt) {
 318         case NETDEV_REGISTER:
 319                 if (trigger_data->net_dev)
 320                         dev_put(trigger_data->net_dev);
 321                 dev_hold(dev);
 322                 trigger_data->net_dev = dev;
 323                 break;
 324         case NETDEV_UNREGISTER:
 325                 dev_put(trigger_data->net_dev);
 326                 trigger_data->net_dev = NULL;
 327                 break;
 328         case NETDEV_UP:
 329         case NETDEV_CHANGE:
 330                 if (netif_carrier_ok(dev))
 331                         set_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode);
 332                 break;
 333         }
 334
 335         set_baseline_state(trigger_data);
 336
 337         spin_unlock_bh(&trigger_data->lock);
 338
 339         return NOTIFY_DONE;
 340 }
 341
 342 /* here's the real work! */
 343 static void netdev_trig_work(struct work_struct *work)
 344 {
 345         struct led_netdev_data *trigger_data =
 346                 container_of(work, struct led_netdev_data, work.work);
 347         struct rtnl_link_stats64 *dev_stats;
 348         unsigned int new_activity;
 349         struct rtnl_link_stats64 temp;
 350         unsigned long interval;
 351         int invert;
 352
 353         /* If we dont have a device, insure we are off */
 354         if (!trigger_data->net_dev) {
 355                 led_set_brightness(trigger_data->led_cdev, LED_OFF);
 356                 return;
 357         }
 358
 359         /* If we are not looking for RX/TX then return  */
 360         if (!test_bit(NETDEV_LED_TX, &trigger_data->mode) &&
 361             !test_bit(NETDEV_LED_RX, &trigger_data->mode))
 362                 return;
 363
 364         dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
 365         new_activity =
 366             (test_bit(NETDEV_LED_TX, &trigger_data->mode) ?
 367                 dev_stats->tx_packets : 0) +
 368             (test_bit(NETDEV_LED_RX, &trigger_data->mode) ?
 369                 dev_stats->rx_packets : 0);
 370
 371         if (trigger_data->last_activity != new_activity) {
 372                 led_stop_software_blink(trigger_data->led_cdev);
 373
 374                 invert = test_bit(NETDEV_LED_LINK, &trigger_data->mode);
 375                 interval = jiffies_to_msecs(
 376                                 atomic_read(&trigger_data->interval));
 377                 /* base state is ON (link present) */
 378                 led_blink_set_oneshot(trigger_data->led_cdev,
 379                                       &interval,
 380                                       &interval,
 381                                       invert);
 382                 trigger_data->last_activity = new_activity;
 383         }
 384
 385         schedule_delayed_work(&trigger_data->work,
 386                         (atomic_read(&trigger_data->interval)*2));
 387 }
 388
 389 static int netdev_trig_activate(struct led_classdev *led_cdev)
 390 {
 391         struct led_netdev_data *trigger_data;
 392         int rc;
 393
 394         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 395         if (!trigger_data)
 396                 return -ENOMEM;
 397
 398         spin_lock_init(&trigger_data->lock);
 399
 400         trigger_data->notifier.notifier_call = netdev_trig_notify;
 401         trigger_data->notifier.priority = 10;
 402
 403         INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
 404
 405         trigger_data->led_cdev = led_cdev;
 406         trigger_data->net_dev = NULL;
 407         trigger_data->device_name[0] = 0;
 408
 409         trigger_data->mode = 0;
 410         atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
 411         trigger_data->last_activity = 0;
 412
 413         led_set_trigger_data(led_cdev, trigger_data);
 414
 415         rc = register_netdevice_notifier(&trigger_data->notifier);
 416         if (rc)
 417                 kfree(trigger_data);
 418
 419         return rc;
 420 }
 421
 422 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 423 {
 424         struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
 425
 426         unregister_netdevice_notifier(&trigger_data->notifier);
 427
 428         cancel_delayed_work_sync(&trigger_data->work);
 429
 430         if (trigger_data->net_dev)
 431                 dev_put(trigger_data->net_dev);
 432
 433         kfree(trigger_data);
 434 }
 435
 436 static struct led_trigger netdev_led_trigger = {
 437         .name = "netdev",
 438         .activate = netdev_trig_activate,
 439         .deactivate = netdev_trig_deactivate,
 440         .groups = netdev_trig_groups,
 441 };
 442
 443 static int __init netdev_trig_init(void)
 444 {
 445         return led_trigger_register(&netdev_led_trigger);
 446 }
 447
 448 static void __exit netdev_trig_exit(void)
 449 {
 450         led_trigger_unregister(&netdev_led_trigger);
 451 }
 452
 453 module_init(netdev_trig_init);
 454 module_exit(netdev_trig_exit);
 455
 456 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
 457 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
 458 MODULE_DESCRIPTION("Netdev LED trigger");
 459 MODULE_LICENSE("GPL v2");