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 #include <linux/version.h>
  31
  32 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
  33 #include <net/net_namespace.h>
  34 #endif
  35
  36 #include "leds.h"
  37
  38 /*
  39  * Configurable sysfs attributes:
  40  *
  41  * device_name - network device name to monitor
  42  *
  43  * interval - duration of LED blink, in milliseconds
  44  *
  45  * mode - either "none" (LED is off) or a space separated list of one or more of:
  46  *   link: LED's normal state reflects whether the link is up (has carrier) or not
  47  *   tx:   LED blinks on transmitted data
  48  *   rx:   LED blinks on receive data
  49  *
  50  * Some suggestions:
  51  *
  52  *  Simple link status LED:
  53  *  $ echo netdev >someled/trigger
  54  *  $ echo eth0 >someled/device_name
  55  *  $ echo link >someled/mode
  56  *
  57  *  Ethernet-style link/activity LED:
  58  *  $ echo netdev >someled/trigger
  59  *  $ echo eth0 >someled/device_name
  60  *  $ echo "link tx rx" >someled/mode
  61  *
  62  *  Modem-style tx/rx LEDs:
  63  *  $ echo netdev >led1/trigger
  64  *  $ echo ppp0 >led1/device_name
  65  *  $ echo tx >led1/mode
  66  *  $ echo netdev >led2/trigger
  67  *  $ echo ppp0 >led2/device_name
  68  *  $ echo rx >led2/mode
  69  *
  70  */
  71
  72 #define MODE_LINK 1
  73 #define MODE_TX   2
  74 #define MODE_RX   4
  75
  76 struct led_netdev_data {
  77         rwlock_t lock;
  78
  79         struct timer_list timer;
  80         struct notifier_block notifier;
  81
  82         struct led_classdev *led_cdev;
  83         struct net_device *net_dev;
  84
  85         char device_name[IFNAMSIZ];
  86         unsigned interval;
  87         unsigned mode;
  88         unsigned link_up;
  89         unsigned last_activity;
  90 };
  91
  92 static void set_baseline_state(struct led_netdev_data *trigger_data)
  93 {
  94         if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
  95                 led_set_brightness(trigger_data->led_cdev, LED_FULL);
  96         else
  97                 led_set_brightness(trigger_data->led_cdev, LED_OFF);
  98
  99         if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up)
 100                 mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
 101         else
 102                 del_timer(&trigger_data->timer);
 103 }
 104
 105 static ssize_t led_device_name_show(struct device *dev,
 106                                     struct device_attribute *attr, char *buf)
 107 {
 108         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 109         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 110
 111         read_lock(&trigger_data->lock);
 112         sprintf(buf, "%s\n", trigger_data->device_name);
 113         read_unlock(&trigger_data->lock);
 114
 115         return strlen(buf) + 1;
 116 }
 117
 118 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
 119 extern struct net init_net;
 120 #endif
 121
 122 static ssize_t led_device_name_store(struct device *dev,
 123                                      struct device_attribute *attr, const char *buf, size_t size)
 124 {
 125         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 126         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 127
 128         if (size < 0 || size >= IFNAMSIZ)
 129                 return -EINVAL;
 130
 131         write_lock(&trigger_data->lock);
 132
 133         strcpy(trigger_data->device_name, buf);
 134         if (size > 0 && trigger_data->device_name[size-1] == '\n')
 135                 trigger_data->device_name[size-1] = 0;
 136
 137         if (trigger_data->device_name[0] != 0) {
 138                 /* check for existing device to update from */
 139 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
 140                 trigger_data->net_dev = dev_get_by_name(&init_net, trigger_data->device_name);
 141 #else
 142                 trigger_data->net_dev = dev_get_by_name(trigger_data->device_name);
 143 #endif
 144                 if (trigger_data->net_dev != NULL)
 145                         trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
 146                 set_baseline_state(trigger_data); /* updates LEDs, may start timers */
 147         }
 148
 149         write_unlock(&trigger_data->lock);
 150         return size;
 151 }
 152
 153 static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);
 154
 155 static ssize_t led_mode_show(struct device *dev,
 156                              struct device_attribute *attr, char *buf)
 157 {
 158         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 159         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 160
 161         read_lock(&trigger_data->lock);
 162
 163         if (trigger_data->mode == 0) {
 164                 strcpy(buf, "none\n");
 165         } else {
 166                 if (trigger_data->mode & MODE_LINK)
 167                         strcat(buf, "link ");
 168                 if (trigger_data->mode & MODE_TX)
 169                         strcat(buf, "tx ");
 170                 if (trigger_data->mode & MODE_RX)
 171                         strcat(buf, "rx ");
 172                 strcat(buf, "\n");
 173         }
 174
 175         read_unlock(&trigger_data->lock);
 176
 177         return strlen(buf)+1;
 178 }
 179
 180 static ssize_t led_mode_store(struct device *dev,
 181                               struct device_attribute *attr, const char *buf, size_t size)
 182 {
 183         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 184         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 185         char copybuf[128];
 186         int new_mode = -1;
 187         char *p, *token;
 188
 189         /* take a copy since we don't want to trash the inbound buffer when using strsep */
 190         strncpy(copybuf, buf, sizeof(copybuf));
 191         copybuf[sizeof(copybuf) - 1] = 0;
 192         p = copybuf;
 193
 194         while ((token = strsep(&p, " \t\n")) != NULL) {
 195                 if (!*token)
 196                         continue;
 197
 198                 if (new_mode == -1)
 199                         new_mode = 0;
 200
 201                 if (!strcmp(token, "none"))
 202                         new_mode = 0;
 203                 else if (!strcmp(token, "tx"))
 204                         new_mode |= MODE_TX;
 205                 else if (!strcmp(token, "rx"))
 206                         new_mode |= MODE_RX;
 207                 else if (!strcmp(token, "link"))
 208                         new_mode |= MODE_LINK;
 209                 else
 210                         return -EINVAL;
 211         }
 212
 213         if (new_mode == -1)
 214                 return -EINVAL;
 215
 216         write_lock(&trigger_data->lock);
 217         trigger_data->mode = new_mode;
 218         set_baseline_state(trigger_data);
 219         write_unlock(&trigger_data->lock);
 220
 221         return size;
 222 }
 223
 224 static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);
 225
 226 static ssize_t led_interval_show(struct device *dev,
 227                                  struct device_attribute *attr, char *buf)
 228 {
 229         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 230         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 231
 232         read_lock(&trigger_data->lock);
 233         sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
 234         read_unlock(&trigger_data->lock);
 235
 236         return strlen(buf) + 1;
 237 }
 238
 239 static ssize_t led_interval_store(struct device *dev,
 240                                   struct device_attribute *attr, const char *buf, size_t size)
 241 {
 242         struct led_classdev *led_cdev = dev_get_drvdata(dev);
 243         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 244         int ret = -EINVAL;
 245         char *after;
 246         unsigned long value = simple_strtoul(buf, &after, 10);
 247         size_t count = after - buf;
 248
 249         if (*after && isspace(*after))
 250                 count++;
 251
 252         /* impose some basic bounds on the timer interval */
 253         if (count == size && value >= 5 && value <= 10000) {
 254                 write_lock(&trigger_data->lock);
 255                 trigger_data->interval = msecs_to_jiffies(value);
 256                 set_baseline_state(trigger_data); // resets timer
 257                 write_unlock(&trigger_data->lock);
 258                 ret = count;
 259         }
 260
 261         return ret;
 262 }
 263
 264 static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
 265
 266 static int netdev_trig_notify(struct notifier_block *nb,
 267                               unsigned long evt,
 268                               void *dv)
 269 {
 270         struct net_device *dev = dv;
 271         struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
 272
 273         if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER)
 274                 return NOTIFY_DONE;
 275
 276         write_lock(&trigger_data->lock);
 277
 278         if (strcmp(dev->name, trigger_data->device_name))
 279                 goto done;
 280
 281         if (evt == NETDEV_REGISTER) {
 282                 if (trigger_data->net_dev != NULL)
 283                         dev_put(trigger_data->net_dev);
 284                 dev_hold(dev);
 285                 trigger_data->net_dev = dev;
 286                 trigger_data->link_up = 0;
 287                 goto done;
 288         }
 289
 290         if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
 291                 dev_put(trigger_data->net_dev);
 292                 trigger_data->net_dev = NULL;
 293                 goto done;
 294         }
 295
 296         /* UP / DOWN / CHANGE */
 297
 298         trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
 299         set_baseline_state(trigger_data);
 300
 301 done:
 302         write_unlock(&trigger_data->lock);
 303         return NOTIFY_DONE;
 304 }
 305
 306 /* here's the real work! */
 307 static void netdev_trig_timer(unsigned long arg)
 308 {
 309         struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg;
 310         const struct net_device_stats *dev_stats;
 311         unsigned new_activity;
 312
 313         write_lock(&trigger_data->lock);
 314
 315         if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
 316                 /* we don't need to do timer work, just reflect link state. */
 317                 led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
 318                 goto no_restart;
 319         }
 320
 321         dev_stats = dev_get_stats(trigger_data->net_dev);
 322         new_activity =
 323                 ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
 324                 ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
 325
 326         if (trigger_data->mode & MODE_LINK) {
 327                 /* base state is ON (link present) */
 328                 /* if there's no link, we don't get this far and the LED is off */
 329
 330                 /* OFF -> ON always */
 331                 /* ON -> OFF on activity */
 332                 if (trigger_data->led_cdev->brightness == LED_OFF) {
 333                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 334                 } else if (trigger_data->last_activity != new_activity) {
 335                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 336                 }
 337         } else {
 338                 /* base state is OFF */
 339                 /* ON -> OFF always */
 340                 /* OFF -> ON on activity */
 341                 if (trigger_data->led_cdev->brightness == LED_FULL) {
 342                         led_set_brightness(trigger_data->led_cdev, LED_OFF);
 343                 } else if (trigger_data->last_activity != new_activity) {
 344                         led_set_brightness(trigger_data->led_cdev, LED_FULL);
 345                 }
 346         }
 347
 348         trigger_data->last_activity = new_activity;
 349         mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
 350
 351 no_restart:
 352         write_unlock(&trigger_data->lock);
 353 }
 354
 355 static void netdev_trig_activate(struct led_classdev *led_cdev)
 356 {
 357         struct led_netdev_data *trigger_data;
 358         int rc;
 359
 360         trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 361         if (!trigger_data)
 362                 return;
 363
 364         rwlock_init(&trigger_data->lock);
 365
 366         trigger_data->notifier.notifier_call = netdev_trig_notify;
 367         trigger_data->notifier.priority = 10;
 368
 369         setup_timer(&trigger_data->timer, netdev_trig_timer, (unsigned long) trigger_data);
 370
 371         trigger_data->led_cdev = led_cdev;
 372         trigger_data->net_dev = NULL;
 373         trigger_data->device_name[0] = 0;
 374
 375         trigger_data->mode = 0;
 376         trigger_data->interval = msecs_to_jiffies(50);
 377         trigger_data->link_up = 0;
 378         trigger_data->last_activity = 0;
 379
 380         led_cdev->trigger_data = trigger_data;
 381
 382         rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
 383         if (rc)
 384                 goto err_out;
 385         rc = device_create_file(led_cdev->dev, &dev_attr_mode);
 386         if (rc)
 387                 goto err_out_device_name;
 388         rc = device_create_file(led_cdev->dev, &dev_attr_interval);
 389         if (rc)
 390                 goto err_out_mode;
 391
 392         register_netdevice_notifier(&trigger_data->notifier);
 393         return;
 394
 395 err_out_mode:
 396         device_remove_file(led_cdev->dev, &dev_attr_mode);
 397 err_out_device_name:
 398         device_remove_file(led_cdev->dev, &dev_attr_device_name);
 399 err_out:
 400         led_cdev->trigger_data = NULL;
 401         kfree(trigger_data);
 402 }
 403
 404 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 405 {
 406         struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 407
 408         if (trigger_data) {
 409                 unregister_netdevice_notifier(&trigger_data->notifier);
 410
 411                 device_remove_file(led_cdev->dev, &dev_attr_device_name);
 412                 device_remove_file(led_cdev->dev, &dev_attr_mode);
 413                 device_remove_file(led_cdev->dev, &dev_attr_interval);
 414
 415                 write_lock(&trigger_data->lock);
 416
 417                 if (trigger_data->net_dev) {
 418                         dev_put(trigger_data->net_dev);
 419                         trigger_data->net_dev = NULL;
 420                 }
 421
 422                 write_unlock(&trigger_data->lock);
 423
 424                 del_timer_sync(&trigger_data->timer);
 425
 426                 kfree(trigger_data);
 427         }
 428 }
 429
 430 static struct led_trigger netdev_led_trigger = {
 431         .name     = "netdev",
 432         .activate = netdev_trig_activate,
 433         .deactivate = netdev_trig_deactivate,
 434 };
 435
 436 static int __init netdev_trig_init(void)
 437 {
 438         return led_trigger_register(&netdev_led_trigger);
 439 }
 440
 441 static void __exit netdev_trig_exit(void)
 442 {
 443         led_trigger_unregister(&netdev_led_trigger);
 444 }
 445
 446 module_init(netdev_trig_init);
 447 module_exit(netdev_trig_exit);
 448
 449 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
 450 MODULE_DESCRIPTION("Netdev LED trigger");
 451 MODULE_LICENSE("GPL");