cmd/cli: only set DNS for physical interfaces on Windows

By filtering the interfaces by MAC address instead of name.

cmd/cli/net.go

@@ -0,0 +1,34 @@
+package cli
+
+import "strings"
+
+// Copied from https://gist.github.com/Ultraporing/fe52981f678be6831f747c206a4861cb
+
+// Mac Address parts to look for, and identify non-physical devices. There may be more, update me!
+var macAddrPartsToFilter = []string{
+	"00:03:FF",       // Microsoft Hyper-V, Virtual Server, Virtual PC
+	"0A:00:27",       // VirtualBox
+	"00:00:00:00:00", // Teredo Tunneling Pseudo-Interface
+	"00:50:56",       // VMware ESX 3, Server, Workstation, Player
+	"00:1C:14",       // VMware ESX 3, Server, Workstation, Player
+	"00:0C:29",       // VMware ESX 3, Server, Workstation, Player
+	"00:05:69",       // VMware ESX 3, Server, Workstation, Player
+	"00:1C:42",       // Microsoft Hyper-V, Virtual Server, Virtual PC
+	"00:0F:4B",       // Virtual Iron 4
+	"00:16:3E",       // Red Hat Xen, Oracle VM, XenSource, Novell Xen
+	"08:00:27",       // Sun xVM VirtualBox
+	"7A:79",          // Hamachi
+}
+
+// Filters the possible physical interface address by comparing it to known popular VM Software addresses
+// and Teredo Tunneling Pseudo-Interface.
+//
+//lint:ignore U1000 use in net_windows.go
+func isPhysicalInterface(addr string) bool {
+	for _, macPart := range macAddrPartsToFilter {
+		if strings.HasPrefix(strings.ToLower(addr), strings.ToLower(macPart)) {
+			return false
+		}
+	}
+	return true
+}

cmd/cli/net_others.go

@@ -1,4 +1,4 @@
-//go:build !darwin
+//go:build !darwin && !windows
 
 package cli
 

cmd/cli/net_windows.go

@@ -0,0 +1,21 @@
+package cli
+
+import (
+	"net"
+)
+
+func patchNetIfaceName(iface *net.Interface) error {
+	return nil
+}
+
+// validInterface reports whether the *net.Interface is a valid one.
+// On Windows, only physical interfaces are considered valid.
+func validInterface(iface *net.Interface) bool {
+	if iface == nil {
+		return false
+	}
+	if isPhysicalInterface(iface.HardwareAddr.String()) {
+		return true
+	}
+	return false
+}

cmd/cli/prog.go

@@ -707,13 +707,11 @@ func withEachPhysicalInterfaces(excludeIfaceName, context string, f func(i *net.
 		if netIface.Name == excludeIfaceName {
 			return
 		}
-		// Skip Windows Hyper-V Default Switch.
-		if strings.Contains(netIface.Name, "vEthernet") {
-			return
-		}
 		// TODO: investigate whether we should report this error?
 		if err := f(netIface); err == nil {
 			mainLog.Load().Debug().Msgf("%s for interface %q successfully", context, i.Name)
+		} else if !errors.Is(err, errSaveCurrentStaticDNSNotSupported) {
+			mainLog.Load().Err(err).Msgf("%s for interface %q failed", context, i.Name)
 		}
 	})
 }
@@ -728,13 +726,15 @@ func requiredMultiNICsConfig() bool {
 	}
 }
 
+var errSaveCurrentStaticDNSNotSupported = errors.New("saving current DNS is not supported on this platform")
+
 // saveCurrentStaticDNS saves the current static DNS settings for restoring later.
 // Only works on Windows and Mac.
 func saveCurrentStaticDNS(iface *net.Interface) error {
 	switch runtime.GOOS {
 	case "windows", "darwin":
 	default:
-		return nil
+		return errSaveCurrentStaticDNSNotSupported
 	}
 	file := savedStaticDnsSettingsFilePath(iface)
 	ns, _ := currentStaticDNS(iface)