OpenWrt – Rev 4
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/*
* LED Kernel Netdev Trigger
*
* Toggles the LED to reflect the link and traffic state of a named net device
*
* Copyright 2007 Oliver Jowett <oliver@opencloud.com>
*
* Derived from ledtrig-timer.c which is:
* Copyright 2005-2006 Openedhand Ltd.
* Author: Richard Purdie <rpurdie@openedhand.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/netdevice.h>
#include <linux/timer.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include "leds.h"
/*
* Configurable sysfs attributes:
*
* device_name - network device name to monitor
*
* interval - duration of LED blink, in milliseconds
*
* mode - either "none" (LED is off) or a space separated list of one or more of:
* link: LED's normal state reflects whether the link is up (has carrier) or not
* tx: LED blinks on transmitted data
* rx: LED blinks on receive data
*
* Some suggestions:
*
* Simple link status LED:
* $ echo netdev >someled/trigger
* $ echo eth0 >someled/device_name
* $ echo link >someled/mode
*
* Ethernet-style link/activity LED:
* $ echo netdev >someled/trigger
* $ echo eth0 >someled/device_name
* $ echo "link tx rx" >someled/mode
*
* Modem-style tx/rx LEDs:
* $ echo netdev >led1/trigger
* $ echo ppp0 >led1/device_name
* $ echo tx >led1/mode
* $ echo netdev >led2/trigger
* $ echo ppp0 >led2/device_name
* $ echo rx >led2/mode
*
*/
#define MODE_LINK 1
#define MODE_TX 2
#define MODE_RX 4
struct led_netdev_data {
spinlock_t lock;
struct delayed_work work;
struct notifier_block notifier;
struct led_classdev *led_cdev;
struct net_device *net_dev;
char device_name[IFNAMSIZ];
unsigned interval;
unsigned mode;
unsigned link_up;
unsigned last_activity;
};
static void set_baseline_state(struct led_netdev_data *trigger_data)
{
if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
led_set_brightness(trigger_data->led_cdev, LED_FULL);
else
led_set_brightness(trigger_data->led_cdev, LED_OFF);
if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 && trigger_data->link_up)
schedule_delayed_work(&trigger_data->work, trigger_data->interval);
}
static ssize_t led_device_name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_netdev_data *trigger_data = led_cdev->trigger_data;
spin_lock_bh(&trigger_data->lock);
sprintf(buf, "%s\n", trigger_data->device_name);
spin_unlock_bh(&trigger_data->lock);
return strlen(buf) + 1;
}
static ssize_t led_device_name_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_netdev_data *trigger_data = led_cdev->trigger_data;
if (size >= IFNAMSIZ)
return -EINVAL;
cancel_delayed_work_sync(&trigger_data->work);
spin_lock_bh(&trigger_data->lock);
strcpy(trigger_data->device_name, buf);
if (size > 0 && trigger_data->device_name[size-1] == '\n')
trigger_data->device_name[size-1] = 0;
trigger_data->link_up = 0;
trigger_data->last_activity = 0;
if (trigger_data->device_name[0] != 0) {
/* check for existing device to update from */
trigger_data->net_dev = dev_get_by_name(&init_net, trigger_data->device_name);
if (trigger_data->net_dev != NULL)
trigger_data->link_up = (dev_get_flags(trigger_data->net_dev) & IFF_LOWER_UP) != 0;
}
set_baseline_state(trigger_data);
spin_unlock_bh(&trigger_data->lock);
return size;
}
static DEVICE_ATTR(device_name, 0644, led_device_name_show, led_device_name_store);
static ssize_t led_mode_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_netdev_data *trigger_data = led_cdev->trigger_data;
spin_lock_bh(&trigger_data->lock);
if (trigger_data->mode == 0) {
strcpy(buf, "none\n");
} else {
if (trigger_data->mode & MODE_LINK)
strcat(buf, "link ");
if (trigger_data->mode & MODE_TX)
strcat(buf, "tx ");
if (trigger_data->mode & MODE_RX)
strcat(buf, "rx ");
strcat(buf, "\n");
}
spin_unlock_bh(&trigger_data->lock);
return strlen(buf)+1;
}
static ssize_t led_mode_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_netdev_data *trigger_data = led_cdev->trigger_data;
char copybuf[128];
int new_mode = -1;
char *p, *token;
/* take a copy since we don't want to trash the inbound buffer when using strsep */
strncpy(copybuf, buf, sizeof(copybuf));
copybuf[sizeof(copybuf) - 1] = 0;
p = copybuf;
while ((token = strsep(&p, " \t\n")) != NULL) {
if (!*token)
continue;
if (new_mode == -1)
new_mode = 0;
if (!strcmp(token, "none"))
new_mode = 0;
else if (!strcmp(token, "tx"))
new_mode |= MODE_TX;
else if (!strcmp(token, "rx"))
new_mode |= MODE_RX;
else if (!strcmp(token, "link"))
new_mode |= MODE_LINK;
else
return -EINVAL;
}
if (new_mode == -1)
return -EINVAL;
cancel_delayed_work_sync(&trigger_data->work);
spin_lock_bh(&trigger_data->lock);
trigger_data->mode = new_mode;
set_baseline_state(trigger_data);
spin_unlock_bh(&trigger_data->lock);
return size;
}
static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);
static ssize_t led_interval_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_netdev_data *trigger_data = led_cdev->trigger_data;
spin_lock_bh(&trigger_data->lock);
sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
spin_unlock_bh(&trigger_data->lock);
return strlen(buf) + 1;
}
static ssize_t led_interval_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_netdev_data *trigger_data = led_cdev->trigger_data;
int ret = -EINVAL;
char *after;
unsigned long value = simple_strtoul(buf, &after, 10);
size_t count = after - buf;
if (isspace(*after))
count++;
/* impose some basic bounds on the timer interval */
if (count == size && value >= 5 && value <= 10000) {
cancel_delayed_work_sync(&trigger_data->work);
spin_lock_bh(&trigger_data->lock);
trigger_data->interval = msecs_to_jiffies(value);
set_baseline_state(trigger_data); /* resets timer */
spin_unlock_bh(&trigger_data->lock);
ret = count;
}
return ret;
}
static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
static int netdev_trig_notify(struct notifier_block *nb,
unsigned long evt,
void *dv)
{
struct net_device *dev = netdev_notifier_info_to_dev((struct netdev_notifier_info *) dv);
struct led_netdev_data *trigger_data = container_of(nb, struct led_netdev_data, notifier);
if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER && evt != NETDEV_CHANGENAME)
return NOTIFY_DONE;
if (strcmp(dev->name, trigger_data->device_name))
return NOTIFY_DONE;
cancel_delayed_work_sync(&trigger_data->work);
spin_lock_bh(&trigger_data->lock);
if (evt == NETDEV_REGISTER || evt == NETDEV_CHANGENAME) {
if (trigger_data->net_dev != NULL)
dev_put(trigger_data->net_dev);
dev_hold(dev);
trigger_data->net_dev = dev;
trigger_data->link_up = 0;
goto done;
}
if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
dev_put(trigger_data->net_dev);
trigger_data->net_dev = NULL;
goto done;
}
/* UP / DOWN / CHANGE */
trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
set_baseline_state(trigger_data);
done:
spin_unlock_bh(&trigger_data->lock);
return NOTIFY_DONE;
}
/* here's the real work! */
static void netdev_trig_work(struct work_struct *work)
{
struct led_netdev_data *trigger_data = container_of(work, struct led_netdev_data, work.work);
struct rtnl_link_stats64 *dev_stats;
unsigned new_activity;
struct rtnl_link_stats64 temp;
if (!trigger_data->link_up || !trigger_data->net_dev || (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
/* we don't need to do timer work, just reflect link state. */
led_set_brightness(trigger_data->led_cdev, ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up) ? LED_FULL : LED_OFF);
return;
}
dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
new_activity =
((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
if (trigger_data->mode & MODE_LINK) {
/* base state is ON (link present) */
/* if there's no link, we don't get this far and the LED is off */
/* OFF -> ON always */
/* ON -> OFF on activity */
if (trigger_data->led_cdev->brightness == LED_OFF) {
led_set_brightness(trigger_data->led_cdev, LED_FULL);
} else if (trigger_data->last_activity != new_activity) {
led_set_brightness(trigger_data->led_cdev, LED_OFF);
}
} else {
/* base state is OFF */
/* ON -> OFF always */
/* OFF -> ON on activity */
if (trigger_data->led_cdev->brightness == LED_FULL) {
led_set_brightness(trigger_data->led_cdev, LED_OFF);
} else if (trigger_data->last_activity != new_activity) {
led_set_brightness(trigger_data->led_cdev, LED_FULL);
}
}
trigger_data->last_activity = new_activity;
schedule_delayed_work(&trigger_data->work, trigger_data->interval);
}
static void netdev_trig_activate(struct led_classdev *led_cdev)
{
struct led_netdev_data *trigger_data;
int rc;
trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
if (!trigger_data)
return;
spin_lock_init(&trigger_data->lock);
trigger_data->notifier.notifier_call = netdev_trig_notify;
trigger_data->notifier.priority = 10;
INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);
trigger_data->led_cdev = led_cdev;
trigger_data->net_dev = NULL;
trigger_data->device_name[0] = 0;
trigger_data->mode = 0;
trigger_data->interval = msecs_to_jiffies(50);
trigger_data->link_up = 0;
trigger_data->last_activity = 0;
led_cdev->trigger_data = trigger_data;
rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
if (rc)
goto err_out;
rc = device_create_file(led_cdev->dev, &dev_attr_mode);
if (rc)
goto err_out_device_name;
rc = device_create_file(led_cdev->dev, &dev_attr_interval);
if (rc)
goto err_out_mode;
register_netdevice_notifier(&trigger_data->notifier);
return;
err_out_mode:
device_remove_file(led_cdev->dev, &dev_attr_mode);
err_out_device_name:
device_remove_file(led_cdev->dev, &dev_attr_device_name);
err_out:
led_cdev->trigger_data = NULL;
kfree(trigger_data);
}
static void netdev_trig_deactivate(struct led_classdev *led_cdev)
{
struct led_netdev_data *trigger_data = led_cdev->trigger_data;
if (trigger_data) {
unregister_netdevice_notifier(&trigger_data->notifier);
device_remove_file(led_cdev->dev, &dev_attr_device_name);
device_remove_file(led_cdev->dev, &dev_attr_mode);
device_remove_file(led_cdev->dev, &dev_attr_interval);
cancel_delayed_work_sync(&trigger_data->work);
spin_lock_bh(&trigger_data->lock);
if (trigger_data->net_dev) {
dev_put(trigger_data->net_dev);
trigger_data->net_dev = NULL;
}
spin_unlock_bh(&trigger_data->lock);
kfree(trigger_data);
}
}
static struct led_trigger netdev_led_trigger = {
.name = "netdev",
.activate = netdev_trig_activate,
.deactivate = netdev_trig_deactivate,
};
static int __init netdev_trig_init(void)
{
return led_trigger_register(&netdev_led_trigger);
}
static void __exit netdev_trig_exit(void)
{
led_trigger_unregister(&netdev_led_trigger);
}
module_init(netdev_trig_init);
module_exit(netdev_trig_exit);
MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
MODULE_DESCRIPTION("Netdev LED trigger");
MODULE_LICENSE("GPL");