func addEndpointGatewaysFromConfig()

in common/core/network.go [240:288]
38 lines of code
12 McCabe index (conditional complexity)

func addEndpointGatewaysFromConfig(
	endpointInfo *network.EndpointInfo,
	cniConfig *cni.NetworkConfig) {

	defaultDestipv4, defaultDestipv4Network, _ := net.ParseCIDR("0.0.0.0/0")
	defaultDestipv6, defaultDestipv6Network, _ := net.ParseCIDR("::/0")

	for _, addr := range cniConfig.AdditionalRoutes {

		var isv4 bool
		if addr.GW.To4() != nil {
			isv4 = true
		}

		if isv4 {
			if endpointInfo.Gateway == nil {

				logrus.Debugf("[cni-net] Found no ipv4 gateway")
				
				m1, _ := addr.Dst.Mask.Size()
				m2, _ := defaultDestipv4Network.Mask.Size()

				if m1 == m2 &&
				   addr.Dst.IP.Equal(defaultDestipv4) {
					endpointInfo.Gateway = addr.GW
					logrus.Debugf("[cni-net] Assigned % as ipv4 gateway", endpointInfo.Gateway.String())
				}
			}
		} else {
			if endpointInfo.Gateway6 == nil {
				
				logrus.Debugf("[cni-net] Found no ipv6 gateway")

				m1, _ := addr.Dst.Mask.Size()
				m2, _ := defaultDestipv6Network.Mask.Size()

				if m1 == m2 &&
				   addr.Dst.IP.Equal(defaultDestipv6) {
					endpointInfo.Gateway6 = addr.GW
					logrus.Debugf("[cni-net] Assigned % as ipv6 gateway", endpointInfo.Gateway6.String())
				}
			}
		}

		if endpointInfo.Gateway != nil && endpointInfo.Gateway6 != nil {
			break
		}
	}
}