Add command to set devlink device switchdev mode

Devlink device currently has legacy and switchdev mode.
Add an API to set devlink device mode for discovered devlink device.

Signed-off-by: Parav Pandit <parav@mellanox.com>

devlink_linux.go

@@ -3,6 +3,7 @@ package netlink
 import (
 	"syscall"
 
+	"fmt"
 	"github.com/vishvananda/netlink/nl"
 	"golang.org/x/sys/unix"
 )
@@ -42,6 +43,16 @@ func parseDevLinkDeviceList(msgs [][]byte) ([]*DevlinkDevice, error) {
 	return devices, nil
 }
 
+func eswitchStringToMode(modeName string) (uint16, error) {
+	if modeName == "legacy" {
+		return nl.DEVLINK_ESWITCH_MODE_LEGACY, nil
+	} else if modeName == "switchdev" {
+		return nl.DEVLINK_ESWITCH_MODE_SWITCHDEV, nil
+	} else {
+		return 0xffff, fmt.Errorf("invalid switchdev mode")
+	}
+}
+
 func parseEswitchMode(mode uint16) string {
 	var eswitchMode = map[uint16]string{
 		nl.DEVLINK_ESWITCH_MODE_LEGACY:    "legacy",
@@ -230,3 +241,32 @@ func (h *Handle) DevLinkGetDeviceByName(Bus string, Device string) (*DevlinkDevi
 func DevLinkGetDeviceByName(Bus string, Device string) (*DevlinkDevice, error) {
 	return pkgHandle.DevLinkGetDeviceByName(Bus, Device)
 }
+
+// DevLinkSetEswitchMode sets eswitch mode if able to set successfully or
+// returns an error code.
+// Equivalent to: `devlink dev eswitch set $dev mode switchdev`
+// Equivalent to: `devlink dev eswitch set $dev mode legacy`
+func (h *Handle) DevLinkSetEswitchMode(Dev *DevlinkDevice, NewMode string) error {
+	mode, err := eswitchStringToMode(NewMode)
+	if err != nil {
+		return err
+	}
+
+	_, req, err := h.createCmdReq(nl.DEVLINK_CMD_ESWITCH_SET, Dev.BusName, Dev.DeviceName)
+	if err != nil {
+		return err
+	}
+
+	req.AddData(nl.NewRtAttr(nl.DEVLINK_ATTR_ESWITCH_MODE, nl.Uint16Attr(mode)))
+
+	_, err = req.Execute(unix.NETLINK_GENERIC, 0)
+	return err
+}
+
+// DevLinkSetEswitchMode sets eswitch mode if able to set successfully or
+// returns an error code.
+// Equivalent to: `devlink dev eswitch set $dev mode switchdev`
+// Equivalent to: `devlink dev eswitch set $dev mode legacy`
+func DevLinkSetEswitchMode(Dev *DevlinkDevice, NewMode string) error {
+	return pkgHandle.DevLinkSetEswitchMode(Dev, NewMode)
+}

devlink_test.go

@@ -23,3 +23,20 @@ func TestDevLinkGetDeviceByName(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestDevLinkSetEswitchMode(t *testing.T) {
+	minKernelRequired(t, 4, 12)
+	setUpNetlinkTestWithKModule(t, "devlink")
+	dev, err := DevLinkGetDeviceByName("foo", "bar")
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = DevLinkSetEswitchMode(dev, "switchdev")
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = DevLinkSetEswitchMode(dev, "legacy")
+	if err != nil {
+		t.Fatal(err)
+	}
+}

nl/devlink_linux.go

@@ -11,6 +11,7 @@ const (
 const (
 	DEVLINK_CMD_GET         = 1
 	DEVLINK_CMD_ESWITCH_GET = 29
+	DEVLINK_CMD_ESWITCH_SET = 30
 )
 
 const (