deprecate DeviceFromIface (facebook#404)

Summary:

Deprecate `DeviceFromIface` function which duplicates the functionality of `IfaceToPHCDevice` – retrieving a path to `/dev/ptp𝑛` corresponding to a given network interface. The later is already optimal and has more identifiable references.

Reviewed By: abulimov

Differential Revision: D64332922

ntp/responder/server/server_linux.go

@@ -97,7 +97,7 @@ func deleteIfaceIP(iface *net.Interface, addr *net.IP) error {
 
 // PHCOffset periodically checks for PHC-SYS offset and updates it in the config
 func phcOffset(iface string) (time.Duration, error) {
-	device, err := phc.DeviceFromIface(iface)
+	device, err := phc.IfaceToPHCDevice(iface)
 	if err != nil {
 		return 0, err
 	}

phc/device.go

@@ -246,24 +246,3 @@ func IfacesInfo() ([]IfaceData, error) {
 	}
 	return res, nil
 }
-
-// DeviceFromIface returns a path to a PHC device from a network interface
-func DeviceFromIface(iface string) (string, error) {
-	ifaces, err := IfacesInfo()
-	if err != nil {
-		return "", err
-	}
-	if len(ifaces) == 0 {
-		return "", fmt.Errorf("no network devices found")
-	}
-
-	for _, d := range ifaces {
-		if d.Iface.Name == iface {
-			if d.TSInfo.PHCIndex < 0 {
-				return "", fmt.Errorf("no PHC support for %s", iface)
-			}
-			return fmt.Sprintf("/dev/ptp%d", d.TSInfo.PHCIndex), nil
-		}
-	}
-	return "", fmt.Errorf("%s interface is not found", iface)
-}

phc/device_test.go

@@ -17,25 +17,12 @@ limitations under the License.
 package phc
 
 import (
-	"fmt"
 	"testing"
 	"unsafe"
 
 	"github.com/stretchr/testify/require"
 )
 
-func TestDeviceFromIfaceNotSupported(t *testing.T) {
-	dev, err := DeviceFromIface("lo")
-	require.Equal(t, fmt.Errorf("no PHC support for lo"), err)
-	require.Equal(t, "", dev)
-}
-
-func TestDeviceFromIfaceNotFound(t *testing.T) {
-	dev, err := DeviceFromIface("lol-does-not-exist")
-	require.Equal(t, fmt.Errorf("lol-does-not-exist interface is not found"), err)
-	require.Equal(t, "", dev)
-}
-
 func TestIoctlValues(t *testing.T) {
 	require.Equal(t, iocPinGetfunc, uintptr(3227532550))
 	require.Equal(t, iocPinSetfunc, uintptr(1080048903))

phc/phc.go

@@ -94,20 +94,16 @@ const (
 	PinFuncPhySync                // PTP_PF_PHYSYNC
 )
 
-func ifaceInfoToPHCDevice(info *EthtoolTSinfo) (string, error) {
-	if info.PHCIndex < 0 {
-		return "", fmt.Errorf("interface doesn't support PHC")
-	}
-	return fmt.Sprintf("/dev/ptp%d", info.PHCIndex), nil
-}
-
 // IfaceToPHCDevice returns path to PHC device associated with given network card iface
 func IfaceToPHCDevice(iface string) (string, error) {
 	info, err := IfaceInfo(iface)
 	if err != nil {
 		return "", fmt.Errorf("getting interface %s info: %w", iface, err)
 	}
-	return ifaceInfoToPHCDevice(info)
+	if info.PHCIndex < 0 {
+		return "", fmt.Errorf("%s: no PHC support", iface)
+	}
+	return fmt.Sprintf("/dev/ptp%d", info.PHCIndex), nil
 }
 
 // Time returns time we got from network card

phc/phc_test.go

@@ -22,24 +22,6 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestIfaceInfoToPHCDevice(t *testing.T) {
-	info := &EthtoolTSinfo{
-		PHCIndex: 0,
-	}
-	got, err := ifaceInfoToPHCDevice(info)
-	require.NoError(t, err)
-	require.Equal(t, "/dev/ptp0", got)
-
-	info.PHCIndex = 23
-	got, err = ifaceInfoToPHCDevice(info)
-	require.NoError(t, err)
-	require.Equal(t, "/dev/ptp23", got)
-
-	info.PHCIndex = -1
-	_, err = ifaceInfoToPHCDevice(info)
-	require.Error(t, err)
-}
-
 func TestMaxAdjFreq(t *testing.T) {
 	caps := &PTPClockCaps{
 		MaxAdj: 1000000000,
@@ -52,3 +34,15 @@ func TestMaxAdjFreq(t *testing.T) {
 	got = caps.maxAdj()
 	require.InEpsilon(t, 500000.0, got, 0.00001)
 }
+
+func TestIfaceToPHCDeviceNotSupported(t *testing.T) {
+	dev, err := IfaceToPHCDevice("lo")
+	require.Error(t, err)
+	require.Equal(t, "", dev)
+}
+
+func TestIfaceToPHCDeviceNotFound(t *testing.T) {
+	dev, err := IfaceToPHCDevice("lol-does-not-exist")
+	require.Error(t, err)
+	require.Equal(t, "", dev)
+}