s[i] = v
	}
	return s
}

// LookupPort looks up the port for the given network and service.
//
// LookupPort uses [context.Background] internally; to specify the context, use
// [Resolver.LookupPort].
func LookupPort(network, service string) (port int, err error) {
	return DefaultResolver.LookupPort(context.Background(), network, service)
}

// LookupPort looks up the port for the given network and service.
//

				_, err := LookupCNAME(testNXDOMAIN)
				return err
			},
		},
		{
			name: "LookupHost NXDOMAIN",
			query: func() error {
				_, err := LookupHost(testNXDOMAIN)
				return err
			},
		},
		{
			name: "LookupHost NODATA",
			query: func() error {
				_, err := LookupHost(testNODATA)
				return err
			},
		},
		{
			name: "LookupMX NXDOMAIN",

			services[netw] = m
		}
		for i := 0; i < len(f); i++ {
			if i != 1 { // f[1] was port/net
				m[f[i]] = port
			}
		}
	}
}

// goLookupPort is the native Go implementation of LookupPort.
func goLookupPort(network, service string) (port int, err error) {
	onceReadServices.Do(readServices)
	return lookupPortMap(network, service)

	}
	if netutils.ParseIPSloppy(apiEndpointHost) == nil {
		return APIEndpoint{}, errors.Errorf("invalid API endpoint IP: %s", apiEndpointHost)
	}
	apiEndpointPort, err := net.LookupPort("tcp", apiEndpointPortStr)
	if err != nil {
		return APIEndpoint{}, errors.Wrapf(err, "invalid advertise address endpoint port: %s", apiEndpointPortStr)
	}
	return APIEndpoint{
		AdvertiseAddress: apiEndpointHost,

	if order == hostLookupCgo {
		return cgoLookupIP(ctx, network, host)
	}
	ips, _, err := r.goLookupIPCNAMEOrder(ctx, network, host, order, conf)
	return ips, err
}

func (r *Resolver) lookupPort(ctx context.Context, network, service string) (int, error) {
	// Port lookup is not a DNS operation.
	// Prefer the cgo resolver if possible.
	if !systemConf().mustUseGoResolver(r) {

	}

	lits, err := r.lookupHost(ctx, host)
	if err != nil {
		return
	}
	for _, lit := range lits {
		host, zone := splitHostZone(lit)
		if ip := ParseIP(host); ip != nil {
			addr := IPAddr{IP: ip, Zone: zone}
			addrs = append(addrs, addr)
		}
	}
	return
}

func (r *Resolver) lookupPort(ctx context.Context, network, service string) (port int, err error) {

	)
	switch net {
	case "tcp", "tcp4", "tcp6", "udp", "udp4", "udp6":
		if addr != "" {
			if host, port, err = SplitHostPort(addr); err != nil {
				return nil, err
			}
			if portnum, err = r.LookupPort(ctx, net, port); err != nil {
				return nil, err
			}
		}
	case "ip", "ip4", "ip6":
		if addr != "" {
			host = addr
		}
	default:
		return nil, UnknownNetworkError(net)
	}

		// newLookupIP, and newerLookUP.
		//
		// For now we just let it finish and write to the
		// buffered channel.
		return nil, newDNSError(mapErr(ctx.Err()), name, "")
	}
}

func (r *Resolver) lookupPort(ctx context.Context, network, service string) (int, error) {
	if systemConf().mustUseGoResolver(r) {
		return lookupPortMap(network, service)
	}

	// TODO(bradfitz): finish ctx plumbing

pkg net, method (*Resolver) LookupHost(context.Context, string) ([]string, error)
pkg net, method (*Resolver) LookupIPAddr(context.Context, string) ([]IPAddr, error)
pkg net, method (*Resolver) LookupMX(context.Context, string) ([]*MX, error)
pkg net, method (*Resolver) LookupNS(context.Context, string) ([]*NS, error)
pkg net, method (*Resolver) LookupPort(context.Context, string, string) (int, error)

	"context"
	"net"
	"time"
)

// LookupHost is a function to make custom lookupHost for optional cached DNS requests
type LookupHost func(ctx context.Context, host string) (addrs []string, err error)

// DialContextWithLookupHost is a helper function which returns `net.DialContext` function.
// It randomly fetches an IP via custom LookupHost function and dials it by the given dial