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 if (size >= IFNAMSIZ) 225 return -EINVAL; 226 227 cancel_delayed_work_sync(&trigger_data->work); 228 229 /* 230 * Take RTNL lock before trigger_data lock to prevent potential 231 * deadlock with netdev notifier registration. 232 */ 233 rtnl_lock(); 234 mutex_lock(&trigger_data->lock); 235 236 if (trigger_data->net_dev) { 237 dev_put(trigger_data->net_dev); 238 trigger_data->net_dev = NULL; 239 } 240 241 memcpy(trigger_data->device_name, name, size); 242 trigger_data->device_name[size] = 0; 243 if (size > 0 && trigger_data->device_name[size - 1] == '\n') 244 trigger_data->device_name[size - 1] = 0; 245 246 if (trigger_data->device_name[0] != 0) 247 trigger_data->net_dev = 248 dev_get_by_name(&init_net, trigger_data->device_name); 249 250 trigger_data->carrier_link_up = false; 251 trigger_data->link_speed = SPEED_UNKNOWN; 252 trigger_data->duplex = DUPLEX_UNKNOWN; 253 if (trigger_data->net_dev) 254 get_device_state(trigger_data); 255 256 trigger_data->last_activity = 0; 257 258 set_baseline_state(trigger_data); 259 mutex_unlock(&trigger_data->lock); 260 rtnl_unlock(); 261 262 return 0; 263 } 264 265 static ssize_t device_name_store(struct device *dev, 266 struct device_attribute *attr, const char *buf, 267 size_t size) 268 { 269 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 270 int ret; 271 272 ret = set_device_name(trigger_data, buf, size); 273 274 if (ret < 0) 275 return ret; 276 return size; 277 } 278 279 static DEVICE_ATTR_RW(device_name); 280 281 static ssize_t netdev_led_attr_show(struct device *dev, char *buf, 282 enum led_trigger_netdev_modes attr) 283 { 284 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 285 int bit; 286 287 switch (attr) { 288 case TRIGGER_NETDEV_LINK: 289 case TRIGGER_NETDEV_LINK_10: 290 case TRIGGER_NETDEV_LINK_100: 291 case TRIGGER_NETDEV_LINK_1000: 292 case TRIGGER_NETDEV_HALF_DUPLEX: 293 case TRIGGER_NETDEV_FULL_DUPLEX: 294 case TRIGGER_NETDEV_TX: 295 case TRIGGER_NETDEV_RX: 296 bit = attr; 297 break; 298 default: 299 return -EINVAL; 300 } 301 302 return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode)); 303 } 304 305 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf, 306 size_t size, enum led_trigger_netdev_modes attr) 307 { 308 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 309 unsigned long state, mode = trigger_data->mode; 310 int ret; 311 int bit; 312 313 ret = kstrtoul(buf, 0, &state); 314 if (ret) 315 return ret; 316 317 switch (attr) { 318 case TRIGGER_NETDEV_LINK: 319 case TRIGGER_NETDEV_LINK_10: 320 case TRIGGER_NETDEV_LINK_100: 321 case TRIGGER_NETDEV_LINK_1000: 322 case TRIGGER_NETDEV_HALF_DUPLEX: 323 case TRIGGER_NETDEV_FULL_DUPLEX: 324 case TRIGGER_NETDEV_TX: 325 case TRIGGER_NETDEV_RX: 326 bit = attr; 327 break; 328 default: 329 return -EINVAL; 330 } 331 332 if (state) 333 set_bit(bit, &mode); 334 else 335 clear_bit(bit, &mode); 336 337 if (test_bit(TRIGGER_NETDEV_LINK, &mode) && 338 (test_bit(TRIGGER_NETDEV_LINK_10, &mode) || 339 test_bit(TRIGGER_NETDEV_LINK_100, &mode) || 340 test_bit(TRIGGER_NETDEV_LINK_1000, &mode))) 341 return -EINVAL; 342 343 cancel_delayed_work_sync(&trigger_data->work); 344 345 trigger_data->mode = mode; 346 trigger_data->hw_control = can_hw_control(trigger_data); 347 348 set_baseline_state(trigger_data); 349 350 return size; 351 } 352 353 #define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \ 354 static ssize_t trigger_name##_show(struct device *dev, \ 355 struct device_attribute *attr, char *buf) \ 356 { \ 357 return netdev_led_attr_show(dev, buf, trigger); \ 358 } \ 359 static ssize_t trigger_name##_store(struct device *dev, \ 360 struct device_attribute *attr, const char *buf, size_t size) \ 361 { \ 362 return netdev_led_attr_store(dev, buf, size, trigger); \ 363 } \ 364 static DEVICE_ATTR_RW(trigger_name) 365 366 DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK); 367 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10); 368 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100); 369 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000); 370 DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX); 371 DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX); 372 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX); 373 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX); 374 375 static ssize_t interval_show(struct device *dev, 376 struct device_attribute *attr, char *buf) 377 { 378 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 379 380 return sprintf(buf, "%u\n", 381 jiffies_to_msecs(atomic_read(&trigger_data->interval))); 382 } 383 384 static ssize_t interval_store(struct device *dev, 385 struct device_attribute *attr, const char *buf, 386 size_t size) 387 { 388 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 389 unsigned long value; 390 int ret; 391 392 if (trigger_data->hw_control) 393 return -EINVAL; 394 395 ret = kstrtoul(buf, 0, &value); 396 if (ret) 397 return ret; 398 399 /* impose some basic bounds on the timer interval */ 400 if (value >= 5 && value <= 10000) { 401 cancel_delayed_work_sync(&trigger_data->work); 402 403 atomic_set(&trigger_data->interval, msecs_to_jiffies(value)); 404 set_baseline_state(trigger_data); /* resets timer */ 405 } 406 407 return size; 408 } 409 410 static DEVICE_ATTR_RW(interval); 411 412 static ssize_t offloaded_show(struct device *dev, 413 struct device_attribute *attr, char *buf) 414 { 415 struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); 416 417 return sprintf(buf, "%d\n", trigger_data->hw_control); 418 } 419 420 static DEVICE_ATTR_RO(offloaded); 421 422 static struct attribute *netdev_trig_attrs[] = { 423 &dev_attr_device_name.attr, 424 &dev_attr_link.attr, 425 &dev_attr_link_10.attr, 426 &dev_attr_link_100.attr, 427 &dev_attr_link_1000.attr, 428 &dev_attr_full_duplex.attr, 429 &dev_attr_half_duplex.attr, 430 &dev_attr_rx.attr, 431 &dev_attr_tx.attr, 432 &dev_attr_interval.attr, 433 &dev_attr_offloaded.attr, 434 NULL 435 }; 436 ATTRIBUTE_GROUPS(netdev_trig); 437 438 static int netdev_trig_notify(struct notifier_block *nb, 439 unsigned long evt, void *dv) 440 { 441 struct net_device *dev = 442 netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv); 443 struct led_netdev_data *trigger_data = 444 container_of(nb, struct led_netdev_data, notifier); 445 446 if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE 447 && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER 448 && evt != NETDEV_CHANGENAME) 449 return NOTIFY_DONE; 450 451 if (!(dev == trigger_data->net_dev || 452 (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) || 453 (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name)))) 454 return NOTIFY_DONE; 455 456 cancel_delayed_work_sync(&trigger_data->work); 457 458 mutex_lock(&trigger_data->lock); 459 460 trigger_data->carrier_link_up = false; 461 trigger_data->link_speed = SPEED_UNKNOWN; 462 trigger_data->duplex = DUPLEX_UNKNOWN; 463 switch (evt) { 464 case NETDEV_CHANGENAME: 465 get_device_state(trigger_data); 466 fallthrough; 467 case NETDEV_REGISTER: 468 dev_put(trigger_data->net_dev); 469 dev_hold(dev); 470 trigger_data->net_dev = dev; 471 break; 472 case NETDEV_UNREGISTER: 473 dev_put(trigger_data->net_dev); 474 trigger_data->net_dev = NULL; 475 break; 476 case NETDEV_UP: 477 case NETDEV_CHANGE: 478 get_device_state(trigger_data); 479 break; 480 } 481 482 set_baseline_state(trigger_data); 483 484 mutex_unlock(&trigger_data->lock); 485 486 return NOTIFY_DONE; 487 } 488 489 /* here's the real work! */ 490 static void netdev_trig_work(struct work_struct *work) 491 { 492 struct led_netdev_data *trigger_data = 493 container_of(work, struct led_netdev_data, work.work); 494 struct rtnl_link_stats64 *dev_stats; 495 unsigned int new_activity; 496 struct rtnl_link_stats64 temp; 497 unsigned long interval; 498 int invert; 499 500 /* If we dont have a device, insure we are off */ 501 if (!trigger_data->net_dev) { 502 led_set_brightness(trigger_data->led_cdev, LED_OFF); 503 return; 504 } 505 506 /* If we are not looking for RX/TX then return */ 507 if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) && 508 !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode)) 509 return; 510 511 dev_stats = dev_get_stats(trigger_data->net_dev, &temp); 512 new_activity = 513 (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ? 514 dev_stats->tx_packets : 0) + 515 (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ? 516 dev_stats->rx_packets : 0); 517 518 if (trigger_data->last_activity != new_activity) { 519 led_stop_software_blink(trigger_data->led_cdev); 520 521 invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) || 522 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) || 523 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) || 524 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) || 525 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) || 526 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode); 527 interval = jiffies_to_msecs( 528 atomic_read(&trigger_data->interval)); 529 /* base state is ON (link present) */ 530 led_blink_set_oneshot(trigger_data->led_cdev, 531 &interval, 532 &interval, 533 invert); 534 trigger_data->last_activity = new_activity; 535 } 536 537 schedule_delayed_work(&trigger_data->work, 538 (atomic_read(&trigger_data->interval)*2)); 539 } 540 541 static int netdev_trig_activate(struct led_classdev *led_cdev) 542 { 543 struct led_netdev_data *trigger_data; 544 unsigned long mode = 0; 545 struct device *dev; 546 int rc; 547 548 trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL); 549 if (!trigger_data) 550 return -ENOMEM; 551 552 mutex_init(&trigger_data->lock); 553 554 trigger_data->notifier.notifier_call = netdev_trig_notify; 555 trigger_data->notifier.priority = 10; 556 557 INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work); 558 559 trigger_data->led_cdev = led_cdev; 560 trigger_data->net_dev = NULL; 561 trigger_data->device_name[0] = 0; 562 563 trigger_data->mode = 0; 564 atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL)); 565 trigger_data->last_activity = 0; 566 567 /* Check if hw control is active by default on the LED. 568 * Init already enabled mode in hw control. 569 */ 570 if (supports_hw_control(led_cdev)) { 571 dev = led_cdev->hw_control_get_device(led_cdev); 572 if (dev) { 573 const char *name = dev_name(dev); 574 575 set_device_name(trigger_data, name, strlen(name)); 576 trigger_data->hw_control = true; 577 578 rc = led_cdev->hw_control_get(led_cdev, &mode); 579 if (!rc) 580 trigger_data->mode = mode; 581 } 582 } 583 584 led_set_trigger_data(led_cdev, trigger_data); 585 586 rc = register_netdevice_notifier(&trigger_data->notifier); 587 if (rc) 588 kfree(trigger_data); 589 590 return rc; 591 } 592 593 static void netdev_trig_deactivate(struct led_classdev *led_cdev) 594 { 595 struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev); 596 597 unregister_netdevice_notifier(&trigger_data->notifier); 598 599 cancel_delayed_work_sync(&trigger_data->work); 600 601 led_set_brightness(led_cdev, LED_OFF); 602 603 dev_put(trigger_data->net_dev); 604 605 kfree(trigger_data); 606 } 607 608 static struct led_trigger netdev_led_trigger = { 609 .name = "netdev", 610 .activate = netdev_trig_activate, 611 .deactivate = netdev_trig_deactivate, 612 .groups = netdev_trig_groups, 613 }; 614 615 module_led_trigger(netdev_led_trigger); 616 617 MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>"); 618 MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>"); 619 MODULE_DESCRIPTION("Netdev LED trigger"); 620 MODULE_LICENSE("GPL v2"); 621