vde: support PTP (switchless) socket

See https://github.com/lima-vm/vde_vmnet/tree/v0.4.0#ptp-mode-switchless-mode

Signed-off-by: Akihiro Suda <[email protected]>

Author: AkihiroSuda

pkg/limayaml/default.yaml

@@ -127,6 +127,9 @@ network:
   vde:
     # url points to the vde_switch socket directory, optionally with vde:// prefix
     # - url: "vde:///var/run/vde.ctl"
+    #   # VDE Switch port number (not TCP/UDP port number). Set to 65535 for PTP mode.
+    #   # Default: 0
+    #   switchPort: 0
     #   # MAC address of the instance; lima will pick one based on the instance name,
     #   # so DHCP assigned ip addresses should remain constant over instance restarts.
     #   macAddress: ""

pkg/limayaml/limayaml.go

@@ -112,6 +112,7 @@ type Network struct {
 }
 type VDE struct {
 	URL        string `yaml:"url,omitempty"`
+	SwitchPort uint16 `yaml:"switchPort,omitempty"` // VDE Switch port, not TCP/UDP port
 	MACAddress string `yaml:"macAddress,omitempty"`
 	Name       string `yaml:"name,omitempty"`
 }

pkg/limayaml/validate.go

@@ -186,16 +186,28 @@ func validateNetwork(yNetwork Network) error {
 			if err != nil {
 				return errors.Wrapf(err, "field `%s.url` %q failed stat", field, vdeSwitch)
 			}
-			if !fi.IsDir() {
-				return errors.Wrapf(err, "field `%s.url` %q is not a directory", field, vdeSwitch)
-			}
-			ctlSocket := filepath.Join(vdeSwitch, "ctl")
-			fi, err = os.Stat(ctlSocket)
-			if err != nil {
-				return errors.Wrapf(err, "field `%s.url` control socket %q failed stat", field, ctlSocket)
-			}
-			if fi.Mode()&os.ModeSocket == 0 {
-				return errors.Errorf("field `%s.url` file %q is not a UNIX socket", field, ctlSocket)
+			if fi.IsDir() {
+				/* Switch mode (vdeSwitch is dir, port != 65535) */
+				ctlSocket := filepath.Join(vdeSwitch, "ctl")
+				fi, err = os.Stat(ctlSocket)
+				if err != nil {
+					return errors.Wrapf(err, "field `%s.url` control socket %q failed stat", field, ctlSocket)
+				}
+				if fi.Mode()&os.ModeSocket == 0 {
+					return errors.Errorf("field `%s.url` file %q is not a UNIX socket", field, ctlSocket)
+				}
+				if vde.SwitchPort == 65535 {
+					return errors.Errorf("field `%s.url` points to a non-PTP switch, so the port number must not be 65535", field)
+				}
+			} else {
+				/* PTP mode (vdeSwitch is socket, port == 65535) */
+				if fi.Mode()&os.ModeSocket == 0 {
+					return errors.Errorf("field `%s.url` %q is not a directory nor a UNIX socket", field, vdeSwitch)
+				}
+				if vde.SwitchPort != 65535 {
+					return errors.Errorf("field `%s.url` points to a PTP (switchless) socket %q, so the port number has to be 65535 (got %d)",
+						field, vdeSwitch, vde.SwitchPort)
+				}
 			}
 		} else if runtime.GOOS != "linux" {
 			logrus.Warnf("field `%s.url` is unlikely to work for %s (unless libvdeplug4 has been ported to %s and is installed)",