| 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"); |
| 452 | |
