// Has the destination device been given?
if (skbuf.getDevice() == null) {
// The device has not been send, figure out the route ourselves.
// First lets try to find a route
final IPv4Route route;
route = findRoute(hdr, skbuf);
route.incUseCount();
// Get the device
dev = route.getDevice();
api = route.getDeviceAPI();
// Get my source address if not already set
if (hdr.getSource() == null) {
hdr.setSource(getSourceAddress(route, hdr, skbuf));
}