netdev_has_upper_dev (9) - Linux Man Pages
netdev_has_upper_dev: Check if device is linked to an upper device
netdev_has_upper_dev - Check if device is linked to an upper device
bool netdev_has_upper_dev(struct net_device
*dev, struct net_device *upper_dev);
- upper device to check
Find out if a device is linked to specified upper device and return true in case it is. Note that this checks only immediate upper device, not through a complete stack of devices. The caller must hold the RTNL lock.