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 70struct led_netdev_data { 71 spinlock_t lock; 72 73 struct timer_list timer; 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 86static 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 mod_timer(&trigger_data->timer, jiffies + trigger_data->interval); 95} 96 97static 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 110static 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 < 0 || size >= IFNAMSIZ) 117 return -EINVAL; 118 119 spin_lock_bh(&trigger_data->lock); 120 del_timer_sync(&trigger_data->timer); 121 122 strcpy(trigger_data->device_name, buf); 123 if (size > 0 && trigger_data->device_name[size-1] == '\n') 124 trigger_data->device_name[size-1] = 0; 125 trigger_data->link_up = 0; 126 trigger_data->last_activity = 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 } 134 135 set_baseline_state(trigger_data); 136 spin_unlock_bh(&trigger_data->lock); 137 138 return size; 139} 140 141static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store); 142 143static ssize_t led_mode_show(struct device *dev, 144 struct device_attribute *attr, char *buf) 145{ 146 struct led_classdev *led_cdev = dev_get_drvdata(dev); 147 struct led_netdev_data *trigger_data = led_cdev->trigger_data; 148 149 spin_lock_bh(&trigger_data->lock); 150 151 if (trigger_data->mode == 0) { 152 strcpy(buf, "none\n"); 153 } else { 154 if (trigger_data->mode & MODE_LINK) 155 strcat(buf, "link "); 156 if (trigger_data->mode & MODE_TX) 157 strcat(buf, "tx "); 158 if (trigger_data->mode & MODE_RX) 159 strcat(buf, "rx "); 160 strcat(buf, "\n"); 161 } 162 163 spin_unlock_bh(&trigger_data->lock); 164 165 return strlen(buf)+1; 166} 167 168static ssize_t led_mode_store(struct device *dev, 169 struct device_attribute *attr, const char *buf, size_t size) 170{ 171 struct led_classdev *led_cdev = dev_get_drvdata(dev); 172 struct led_netdev_data *trigger_data = led_cdev->trigger_data; 173 char copybuf[128]; 174 int new_mode = -1; 175 char *p, *token; 176 177 /* take a copy since we don't want to trash the inbound buffer when using strsep */ 178 strncpy(copybuf, buf, sizeof(copybuf)); 179 copybuf[sizeof(copybuf) - 1] = 0; 180 p = copybuf; 181 182 while ((token = strsep(&p, " \t\n")) != NULL) { 183 if (!*token) 184 continue; 185 186 if (new_mode == -1) 187 new_mode = 0; 188 189 if (!strcmp(token, "none")) 190 new_mode = 0; 191 else if (!strcmp(token, "tx")) 192 new_mode |= MODE_TX; 193 else if (!strcmp(token, "rx")) 194 new_mode |= MODE_RX; 195 else if (!strcmp(token, "link")) 196 new_mode |= MODE_LINK; 197 else 198 return -EINVAL; 199 } 200 201 if (new_mode == -1) 202 return -EINVAL; 203 204 spin_lock_bh(&trigger_data->lock); 205 del_timer_sync(&trigger_data->timer); 206 207 trigger_data->mode = new_mode; 208 209 set_baseline_state(trigger_data); 210 spin_unlock_bh(&trigger_data->lock); 211 212 return size; 213} 214 215static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store); 216 217static 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 230static 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 spin_lock_bh(&trigger_data->lock); 246 del_timer_sync(&trigger_data->timer); 247 248 trigger_data->interval = msecs_to_jiffies(value); 249 250 set_baseline_state(trigger_data); /* resets timer */ 251 spin_unlock_bh(&trigger_data->lock); 252 253 ret = count; 254 } 255 256 return ret; 257} 258 259static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store); 260 261static int netdev_trig_notify(struct notifier_block *nb, 262 unsigned long evt, 263 void *dv) 264{ 265 struct net_device *dev = netdev_notifier_info_to_dev((struct netdev_notifier_info *) dv); 266 struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier); 267 268 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER && evt != NETDEV_CHANGENAME) 269 return NOTIFY_DONE; 270 271 spin_lock_bh(&trigger_data->lock); 272 273 if (strcmp(dev->name, trigger_data->device_name)) 274 goto done; 275 276 del_timer_sync(&trigger_data->timer); 277 278 if (evt == NETDEV_REGISTER || evt == NETDEV_CHANGENAME) { 279 if (trigger_data->net_dev != NULL) 280 dev_put(trigger_data->net_dev); 281 282 dev_hold(dev); 283 trigger_data->net_dev = dev; 284 trigger_data->link_up = 0; 285 goto done; 286 } 287 288 if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) { 289 dev_put(trigger_data->net_dev); 290 trigger_data->net_dev = NULL; 291 goto done; 292 } 293 294 /* UP / DOWN / CHANGE */ 295 296 trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev)); 297 set_baseline_state(trigger_data); 298 299done: 300 spin_unlock_bh(&trigger_data->lock); 301 return NOTIFY_DONE; 302} 303 304/* here's the real work! */ 305static void netdev_trig_timer(unsigned long arg) 306{ 307 struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg; 308 struct rtnl_link_stats64 *dev_stats; 309 unsigned new_activity; 310 struct rtnl_link_stats64 temp; 311 312 if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) { 313 /* we don't need to do timer work, just reflect link state. */ 314 led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF); 315 return; 316 } 317 318 dev_stats = dev_get_stats(trigger_data->net_dev, &temp); 319 new_activity = 320 ((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) + 321 ((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0); 322 323 if (trigger_data->mode & MODE_LINK) { 324 /* base state is ON (link present) */ 325 /* if there's no link, we don't get this far and the LED is off */ 326 327 /* OFF -> ON always */ 328 /* ON -> OFF on activity */ 329 if (trigger_data->led_cdev->brightness == LED_OFF) { 330 led_set_brightness(trigger_data->led_cdev, LED_FULL); 331 } else if (trigger_data->last_activity != new_activity) { 332 led_set_brightness(trigger_data->led_cdev, LED_OFF); 333 } 334 } else { 335 /* base state is OFF */ 336 /* ON -> OFF always */ 337 /* OFF -> ON on activity */ 338 if (trigger_data->led_cdev->brightness == LED_FULL) { 339 led_set_brightness(trigger_data->led_cdev, LED_OFF); 340 } else if (trigger_data->last_activity != new_activity) { 341 led_set_brightness(trigger_data->led_cdev, LED_FULL); 342 } 343 } 344 345 trigger_data->last_activity = new_activity; 346 mod_timer(&trigger_data->timer, jiffies + trigger_data->interval); 347} 348 349static void netdev_trig_activate(struct led_classdev *led_cdev) 350{ 351 struct led_netdev_data *trigger_data; 352 int rc; 353 354 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL); 355 if (!trigger_data) 356 return; 357 358 spin_lock_init(&trigger_data->lock); 359 360 trigger_data->notifier.notifier_call = netdev_trig_notify; 361 trigger_data->notifier.priority = 10; 362 363 setup_timer(&trigger_data->timer, netdev_trig_timer, (unsigned long) trigger_data); 364 365 trigger_data->led_cdev = led_cdev; 366 trigger_data->net_dev = NULL; 367 trigger_data->device_name[0] = 0; 368 369 trigger_data->mode = 0; 370 trigger_data->interval = msecs_to_jiffies(50); 371 trigger_data->link_up = 0; 372 trigger_data->last_activity = 0; 373 374 led_cdev->trigger_data = trigger_data; 375 376 rc = device_create_file(led_cdev->dev, &dev_attr_device_name); 377 if (rc) 378 goto err_out; 379 rc = device_create_file(led_cdev->dev, &dev_attr_mode); 380 if (rc) 381 goto err_out_device_name; 382 rc = device_create_file(led_cdev->dev, &dev_attr_interval); 383 if (rc) 384 goto err_out_mode; 385 386 register_netdevice_notifier(&trigger_data->notifier); 387 return; 388 389err_out_mode: 390 device_remove_file(led_cdev->dev, &dev_attr_mode); 391err_out_device_name: 392 device_remove_file(led_cdev->dev, &dev_attr_device_name); 393err_out: 394 led_cdev->trigger_data = NULL; 395 kfree(trigger_data); 396} 397 398static void netdev_trig_deactivate(struct led_classdev *led_cdev) 399{ 400 struct led_netdev_data *trigger_data = led_cdev->trigger_data; 401 402 if (trigger_data) { 403 unregister_netdevice_notifier(&trigger_data->notifier); 404 405 device_remove_file(led_cdev->dev, &dev_attr_device_name); 406 device_remove_file(led_cdev->dev, &dev_attr_mode); 407 device_remove_file(led_cdev->dev, &dev_attr_interval); 408 409 spin_lock_bh(&trigger_data->lock); 410 del_timer_sync(&trigger_data->timer); 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 423static struct led_trigger netdev_led_trigger = { 424 .name = "netdev", 425 .activate = netdev_trig_activate, 426 .deactivate = netdev_trig_deactivate, 427}; 428 429static int __init netdev_trig_init(void) 430{ 431 return led_trigger_register(&netdev_led_trigger); 432} 433 434static void __exit netdev_trig_exit(void) 435{ 436 led_trigger_unregister(&netdev_led_trigger); 437} 438 439module_init(netdev_trig_init); 440module_exit(netdev_trig_exit); 441 442MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>"); 443MODULE_DESCRIPTION("Netdev LED trigger"); 444MODULE_LICENSE("GPL"); 445