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/ethtool.h> 17 #include <linux/init.h> 18 #include <linux/jiffies.h> 19 #include <linux/kernel.h> 20 #include <linux/leds.h> 21 #include <linux/list.h> 22 #include <linux/module.h> 23 #include <linux/netdevice.h> 24 #include <linux/mutex.h> 25 #include <linux/rtnetlink.h> 26 #include <linux/timer.h> 27 #include "../leds.h" 28 29 #define NETDEV_LED_DEFAULT_INTERVAL 50 30 31 /* 32 * Configurable sysfs attributes: 33 * 34 * device_name - network device name to monitor 35 * interval - duration of LED blink, in milliseconds 36 * link - LED's normal state reflects whether the link is up 37 * (has carrier) or not 38 * tx - LED blinks on transmitted data 39 * rx - LED blinks on receive data 40 * 41 */ 42 43 struct led_netdev_data { 44 struct mutex lock; 45 46 struct delayed_work work; 47 struct notifier_block notifier; 48 49 struct led_classdev *led_cdev; 50 struct net_device *net_dev; 51 52 char device_name[IFNAMSIZ]; 53 atomic_t interval; 54 unsigned int last_activity; 55 56 unsigned long mode; 57 int link_speed; 58 u8 duplex; 59 60 bool carrier_link_up; 61 bool hw_control; 62 }; 63 64 static void set_baseline_state(struct led_netdev_data *trigger_data) 65 { 66 int current_brightness; 67 struct led_classdev *led_cdev = trigger_data->led_cdev; 68 69 /* Already validated, hw control is possible with the requested mode */ 70 if (trigger_data->hw_control) { 71 led_cdev->hw_control_set(led_cdev, trigger_data->mode); 72 73 return; 74 } 75 76 current_brightness = led_cdev->brightness; 77 if (current_brightness) 78 led_cdev->blink_brightness = current_brightness; 79 if (!led_cdev->blink_brightness) 80 led_cdev->blink_brightness = led_cdev->max_brightness; 81 82 if (!trigger_data->carrier_link_up) { 83 led_set_brightness(led_cdev, LED_OFF); 84 } else { 85 bool blink_on = false; 86 87 if (test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode)) 88 blink_on = true; 89 90 if (test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) && 91 trigger_data->link_speed == SPEED_10) 92 blink_on = true; 93 94 if (test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) && 95 trigger_data->link_speed == SPEED_100) 96 blink_on = true; 97 98 if (test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) && 99 trigger_data->link_speed == SPEED_1000) 100 blink_on = true; 101 102 if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) && 103 trigger_data->duplex == DUPLEX_HALF) 104 blink_on = true; 105 106 if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) && 107 trigger_data->duplex == DUPLEX_FULL) 108 blink_on = true; 109 110 if (blink_on) 111 led_set_brightness(led_cdev, 112 led_cdev->blink_brightness); 113 else 114 led_set_brightness(led_cdev, LED_OFF); 115 116 /* If we are looking for RX/TX start periodically 117 * checking stats 118 */ 119 if (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) || 120 test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode)) 121 schedule_delayed_work(&trigger_data->work, 0); 122 } 123 } 124 125 static bool supports_hw_control(struct led_classdev *led_cdev) 126 { 127 if (!led_cdev->hw_control_get || !led_cdev->hw_control_set || 128 !led_cdev->hw_control_is_supported) 129 return false; 130 131 return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name); 132 } 133 134 /* 135 * Validate the configured netdev is the same as the one associated with 136 * the LED driver in hw control. 137 */ 138 static bool validate_net_dev(struct led_classdev *led_cdev, 139 struct net_device *net_dev) 140 { 141 struct device *dev = led_cdev->hw_control_get_device(led_cdev); 142 struct net_device *ndev; 143 144 if (!dev) 145 return false; 146 147 ndev = to_net_dev(dev); 148 149 return ndev == net_dev; 150 } 151 152 static bool can_hw_control(struct led_netdev_data *trigger_data) 153 { 154 unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL); 155 unsigned int interval = atomic_read(&trigger_data->interval); 156 struct led_classdev *led_cdev = trigger_data->led_cdev; 157 int ret; 158 159 if (!supports_hw_control(led_cdev)) 160 return false; 161 162 /* 163 * Interval must be set to the default 164 * value. Any different value is rejected if in hw 165 * control. 166 */ 167 if (interval != default_interval) 168 return false; 169 170 /* 171 * net_dev must be set with hw control, otherwise no 172 * blinking can be happening and there is nothing to 173 * offloaded. Additionally, for hw control to be 174 * valid, the configured netdev must be the same as 175 * netdev associated to the LED. 176 */ 177 if (!validate_net_dev(led_cdev, trigger_data->net_dev)) 178 return false; 179 180 /* Check if the requested mode is supported */ 181 ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode); 182 /* Fall back to software blinking if not supported */ 183 if (ret == -EOPNOTSUPP) 184 return false; 185 if (ret) { 186 dev_warn(led_cdev->dev, 187 "Current mode check failed with error %d\n", ret); 188 return false; 189 } 190 191 return true; 192 } 193 194 static void get_device_state(struct led_netdev_data *trigger_data) 195 { 196 struct ethtool_link_ksettings cmd; 197 198 trigger_data->carrier_link_up = netif_carrier_ok(trigger_data->net_dev); 199 if (!trigger_data->carrier_link_up) 200 return; 201 202 if (!__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd)) { 203 trigger_data->link_speed = cmd.base.speed; 204 trigger_data->duplex = cmd.base.duplex; 205 } 206 } 207 208 static ssize_t device_name_show(struct device *dev, 209 struct device_attribute *attr, char *buf) 210 { 211 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 212 ssize_t len; 213 214 mutex_lock(&trigger_data->lock); 215 len = sprintf(buf, "%s\n", trigger_data->device_name); 216 mutex_unlock(&trigger_data->lock); 217 218 return len; 219 } 220 221 static int set_device_name(struct led_netdev_data *trigger_data, 222 const char *name, size_t size) 223 { 224 cancel_delayed_work_sync(&trigger_data->work); 225 226 mutex_lock(&trigger_data->lock); 227 228 if (trigger_data->net_dev) { 229 dev_put(trigger_data->net_dev); 230 trigger_data->net_dev = NULL; 231 } 232 233 memcpy(trigger_data->device_name, name, size); 234 trigger_data->device_name[size] = 0; 235 if (size > 0 && trigger_data->device_name[size - 1] == '\n') 236 trigger_data->device_name[size - 1] = 0; 237 238 if (trigger_data->device_name[0] != 0) 239 trigger_data->net_dev = 240 dev_get_by_name(&init_net, trigger_data->device_name); 241 242 trigger_data->carrier_link_up = false; 243 trigger_data->link_speed = SPEED_UNKNOWN; 244 trigger_data->duplex = DUPLEX_UNKNOWN; 245 if (trigger_data->net_dev != NULL) { 246 rtnl_lock(); 247 get_device_state(trigger_data); 248 rtnl_unlock(); 249 } 250 251 trigger_data->last_activity = 0; 252 253 set_baseline_state(trigger_data); 254 mutex_unlock(&trigger_data->lock); 255 256 return 0; 257 } 258 259 static ssize_t device_name_store(struct device *dev, 260 struct device_attribute *attr, const char *buf, 261 size_t size) 262 { 263 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 264 int ret; 265 266 if (size >= IFNAMSIZ) 267 return -EINVAL; 268 269 ret = set_device_name(trigger_data, buf, size); 270 271 if (ret < 0) 272 return ret; 273 return size; 274 } 275 276 static DEVICE_ATTR_RW(device_name); 277 278 static ssize_t netdev_led_attr_show(struct device *dev, char *buf, 279 enum led_trigger_netdev_modes attr) 280 { 281 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 282 int bit; 283 284 switch (attr) { 285 case TRIGGER_NETDEV_LINK: 286 case TRIGGER_NETDEV_LINK_10: 287 case TRIGGER_NETDEV_LINK_100: 288 case TRIGGER_NETDEV_LINK_1000: 289 case TRIGGER_NETDEV_HALF_DUPLEX: 290 case TRIGGER_NETDEV_FULL_DUPLEX: 291 case TRIGGER_NETDEV_TX: 292 case TRIGGER_NETDEV_RX: 293 bit = attr; 294 break; 295 default: 296 return -EINVAL; 297 } 298 299 return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode)); 300 } 301 302 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf, 303 size_t size, enum led_trigger_netdev_modes attr) 304 { 305 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 306 unsigned long state, mode = trigger_data->mode; 307 int ret; 308 int bit; 309 310 ret = kstrtoul(buf, 0, &state); 311 if (ret) 312 return ret; 313 314 switch (attr) { 315 case TRIGGER_NETDEV_LINK: 316 case TRIGGER_NETDEV_LINK_10: 317 case TRIGGER_NETDEV_LINK_100: 318 case TRIGGER_NETDEV_LINK_1000: 319 case TRIGGER_NETDEV_HALF_DUPLEX: 320 case TRIGGER_NETDEV_FULL_DUPLEX: 321 case TRIGGER_NETDEV_TX: 322 case TRIGGER_NETDEV_RX: 323 bit = attr; 324 break; 325 default: 326 return -EINVAL; 327 } 328 329 if (state) 330 set_bit(bit, &mode); 331 else 332 clear_bit(bit, &mode); 333 334 if (test_bit(TRIGGER_NETDEV_LINK, &mode) && 335 (test_bit(TRIGGER_NETDEV_LINK_10, &mode) || 336 test_bit(TRIGGER_NETDEV_LINK_100, &mode) || 337 test_bit(TRIGGER_NETDEV_LINK_1000, &mode))) 338 return -EINVAL; 339 340 cancel_delayed_work_sync(&trigger_data->work); 341 342 trigger_data->mode = mode; 343 trigger_data->hw_control = can_hw_control(trigger_data); 344 345 set_baseline_state(trigger_data); 346 347 return size; 348 } 349 350 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \ 351 static ssize_t trigger_name##_show(struct device *dev, \ 352 struct device_attribute *attr, char *buf) \ 353 { \ 354 return netdev_led_attr_show(dev, buf, trigger); \ 355 } \ 356 static ssize_t trigger_name##_store(struct device *dev, \ 357 struct device_attribute *attr, const char *buf, size_t size) \ 358 { \ 359 return netdev_led_attr_store(dev, buf, size, trigger); \ 360 } \ 361 static DEVICE_ATTR_RW(trigger_name) 362 363 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK); 364 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10); 365 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100); 366 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000); 367 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX); 368 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX); 369 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX); 370 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX); 371 372 static ssize_t interval_show(struct device *dev, 373 struct device_attribute *attr, char *buf) 374 { 375 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 376 377 return sprintf(buf, "%u\n", 378 jiffies_to_msecs(atomic_read(&trigger_data->interval))); 379 } 380 381 static ssize_t interval_store(struct device *dev, 382 struct device_attribute *attr, const char *buf, 383 size_t size) 384 { 385 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 386 unsigned long value; 387 int ret; 388 389 if (trigger_data->hw_control) 390 return -EINVAL; 391 392 ret = kstrtoul(buf, 0, &value); 393 if (ret) 394 return ret; 395 396 /* impose some basic bounds on the timer interval */ 397 if (value >= 5 && value <= 10000) { 398 cancel_delayed_work_sync(&trigger_data->work); 399 400 atomic_set(&trigger_data->interval, msecs_to_jiffies(value)); 401 set_baseline_state(trigger_data); /* resets timer */ 402 } 403 404 return size; 405 } 406 407 static DEVICE_ATTR_RW(interval); 408 409 static ssize_t hw_control_show(struct device *dev, 410 struct device_attribute *attr, char *buf) 411 { 412 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 413 414 return sprintf(buf, "%d\n", trigger_data->hw_control); 415 } 416 417 static DEVICE_ATTR_RO(hw_control); 418 419 static struct attribute *netdev_trig_attrs[] = { 420 &dev_attr_device_name.attr, 421 &dev_attr_link.attr, 422 &dev_attr_link_10.attr, 423 &dev_attr_link_100.attr, 424 &dev_attr_link_1000.attr, 425 &dev_attr_full_duplex.attr, 426 &dev_attr_half_duplex.attr, 427 &dev_attr_rx.attr, 428 &dev_attr_tx.attr, 429 &dev_attr_interval.attr, 430 &dev_attr_hw_control.attr, 431 NULL 432 }; 433 ATTRIBUTE_GROUPS(netdev_trig); 434 435 static int netdev_trig_notify(struct notifier_block *nb, 436 unsigned long evt, void *dv) 437 { 438 struct net_device *dev = 439 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv); 440 struct led_netdev_data *trigger_data = 441 container_of(nb, struct led_netdev_data, notifier); 442 443 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE 444 && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER 445 && evt != NETDEV_CHANGENAME) 446 return NOTIFY_DONE; 447 448 if (!(dev == trigger_data->net_dev || 449 (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) || 450 (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name)))) 451 return NOTIFY_DONE; 452 453 cancel_delayed_work_sync(&trigger_data->work); 454 455 mutex_lock(&trigger_data->lock); 456 457 trigger_data->carrier_link_up = false; 458 trigger_data->link_speed = SPEED_UNKNOWN; 459 trigger_data->duplex = DUPLEX_UNKNOWN; 460 switch (evt) { 461 case NETDEV_CHANGENAME: 462 get_device_state(trigger_data); 463 fallthrough; 464 case NETDEV_REGISTER: 465 dev_put(trigger_data->net_dev); 466 dev_hold(dev); 467 trigger_data->net_dev = dev; 468 break; 469 case NETDEV_UNREGISTER: 470 dev_put(trigger_data->net_dev); 471 trigger_data->net_dev = NULL; 472 break; 473 case NETDEV_UP: 474 case NETDEV_CHANGE: 475 get_device_state(trigger_data); 476 break; 477 } 478 479 set_baseline_state(trigger_data); 480 481 mutex_unlock(&trigger_data->lock); 482 483 return NOTIFY_DONE; 484 } 485 486 /* here's the real work! */ 487 static void netdev_trig_work(struct work_struct *work) 488 { 489 struct led_netdev_data *trigger_data = 490 container_of(work, struct led_netdev_data, work.work); 491 struct rtnl_link_stats64 *dev_stats; 492 unsigned int new_activity; 493 struct rtnl_link_stats64 temp; 494 unsigned long interval; 495 int invert; 496 497 /* If we dont have a device, insure we are off */ 498 if (!trigger_data->net_dev) { 499 led_set_brightness(trigger_data->led_cdev, LED_OFF); 500 return; 501 } 502 503 /* If we are not looking for RX/TX then return */ 504 if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) && 505 !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode)) 506 return; 507 508 dev_stats = dev_get_stats(trigger_data->net_dev, &temp); 509 new_activity = 510 (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ? 511 dev_stats->tx_packets : 0) + 512 (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ? 513 dev_stats->rx_packets : 0); 514 515 if (trigger_data->last_activity != new_activity) { 516 led_stop_software_blink(trigger_data->led_cdev); 517 518 invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) || 519 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) || 520 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) || 521 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) || 522 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) || 523 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode); 524 interval = jiffies_to_msecs( 525 atomic_read(&trigger_data->interval)); 526 /* base state is ON (link present) */ 527 led_blink_set_oneshot(trigger_data->led_cdev, 528 &interval, 529 &interval, 530 invert); 531 trigger_data->last_activity = new_activity; 532 } 533 534 schedule_delayed_work(&trigger_data->work, 535 (atomic_read(&trigger_data->interval)*2)); 536 } 537 538 static int netdev_trig_activate(struct led_classdev *led_cdev) 539 { 540 struct led_netdev_data *trigger_data; 541 unsigned long mode = 0; 542 struct device *dev; 543 int rc; 544 545 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL); 546 if (!trigger_data) 547 return -ENOMEM; 548 549 mutex_init(&trigger_data->lock); 550 551 trigger_data->notifier.notifier_call = netdev_trig_notify; 552 trigger_data->notifier.priority = 10; 553 554 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work); 555 556 trigger_data->led_cdev = led_cdev; 557 trigger_data->net_dev = NULL; 558 trigger_data->device_name[0] = 0; 559 560 trigger_data->mode = 0; 561 atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL)); 562 trigger_data->last_activity = 0; 563 564 /* Check if hw control is active by default on the LED. 565 * Init already enabled mode in hw control. 566 */ 567 if (supports_hw_control(led_cdev) && 568 !led_cdev->hw_control_get(led_cdev, &mode)) { 569 dev = led_cdev->hw_control_get_device(led_cdev); 570 if (dev) { 571 const char *name = dev_name(dev); 572 573 set_device_name(trigger_data, name, strlen(name)); 574 trigger_data->hw_control = true; 575 trigger_data->mode = mode; 576 } 577 } 578 579 led_set_trigger_data(led_cdev, trigger_data); 580 581 rc = register_netdevice_notifier(&trigger_data->notifier); 582 if (rc) 583 kfree(trigger_data); 584 585 return rc; 586 } 587 588 static void netdev_trig_deactivate(struct led_classdev *led_cdev) 589 { 590 struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev); 591 592 unregister_netdevice_notifier(&trigger_data->notifier); 593 594 cancel_delayed_work_sync(&trigger_data->work); 595 596 dev_put(trigger_data->net_dev); 597 598 kfree(trigger_data); 599 } 600 601 static struct led_trigger netdev_led_trigger = { 602 .name = "netdev", 603 .activate = netdev_trig_activate, 604 .deactivate = netdev_trig_deactivate, 605 .groups = netdev_trig_groups, 606 }; 607 608 static int __init netdev_trig_init(void) 609 { 610 return led_trigger_register(&netdev_led_trigger); 611 } 612 613 static void __exit netdev_trig_exit(void) 614 { 615 led_trigger_unregister(&netdev_led_trigger); 616 } 617 618 module_init(netdev_trig_init); 619 module_exit(netdev_trig_exit); 620 621 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>"); 622 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>"); 623 MODULE_DESCRIPTION("Netdev LED trigger"); 624 MODULE_LICENSE("GPL v2"); 625