Function deviceHasPathForDownlink

pkg/networkserver/utils.go:224–238

(ctx context.Context, dev *ttnpb.EndDevice, down *ttnpb.ApplicationDownlink)

}

func deviceHasPathForDownlink(ctx context.Context, dev *ttnpb.EndDevice, down *ttnpb.ApplicationDownlink) bool {
	if dev.GetMulticast() || dev.GetMacState() == nil {
		return len(down.GetClassBC().GetGateways()) > 0
	}
	switch dev.MacState.DeviceClass {
	case ttnpb.Class_CLASS_A:
		return down.GetClassBC() == nil &&
			len(downlinkPathsFromRecentUplinks(dev.GetMacState().GetRecentUplinks()...)) > 0
	case ttnpb.Class_CLASS_B, ttnpb.Class_CLASS_C:
		return len(downlinkPathsFromRecentUplinks(dev.GetMacState().GetRecentUplinks()...)) > 0 ||
			len(down.GetClassBC().GetGateways()) > 0
	default:
		panic(fmt.Errorf("unmatched class: %v", dev.MacState.DeviceClass))
	}
}

// nextDataDownlinkSlot returns the next downlinkSlot before or at earliestAt when next data downlink can be transmitted to the device
// given the data known by Network Server and true, if such downlinkSlot and downlink exist, otherwise it returns nil and false.