Add support for OpenBSD, FreeBSD, NetBSD and add InterfaceName para…

…meter for Windows to allow selecting between multiple `tap0901` adapters on the same system

CONTRIBUTORS

@@ -9,3 +9,4 @@ Tony Lu <[email protected]>
 ajee cai <[email protected]>
 yinheli <[email protected]>
 Paul Querna <[email protected]>
+Neil Alexander <[email protected]>

README.md

@@ -17,6 +17,9 @@ See https://github.com/songgao/packets for functions for parsing various packets
 * Linux
 * Windows (experimental; APIs might change)
 * macOS (point-to-point TUN only)
+* OpenBSD
+* NetBSD
+* FreeBSD
 
 ## Installation
 ```

params_bsd.go

@@ -0,0 +1,20 @@
+// +build openbsd freebsd netbsd dragonfly
+
+package water
+
+// PlatformSpecificParams defines parameters in Config that are specific to
+// Linux. A zero-value of such type is valid, yielding an interface
+// with OS defined name.
+type PlatformSpecificParams struct {
+	// Name is the name to be set for the interface to be created. This overrides
+	// the default name assigned by OS such as tap0 or tun0. A zero-value of this
+	// field, i.e. an empty string, indicates that the default name should be
+	// used.
+	Name string
+}
+
+func defaultPlatformSpecificParams() PlatformSpecificParams {
+	return PlatformSpecificParams{
+		Name: "/dev/tun0",
+	}
+}

params_others.go

@@ -1,4 +1,4 @@
-// +build !linux,!darwin,!windows
+// +build !linux,!darwin,!windows,!openbsd,!freebsd,!netbsd,!dragonfly
 
 package water
 

params_windows.go

@@ -11,6 +11,10 @@ type PlatformSpecificParams struct {
 	// use the default ComponentId. The default ComponentId is set to tap0901,
 	// the one used by OpenVPN.
 	ComponentID string
+	// Of course, you may have multiple tap0901 adapters on the system, in which
+	// case we need a friendlier way to identify them. In that case we can use
+	// the friendly name of the network adapter as set in Control Panel.
+	InterfaceName string
 	// Network is required when creating a TUN interface. The library will call
 	// net.ParseCIDR() to parse this string into LocalIP, RemoteNetaddr,
 	// RemoteNetmask. The underlying driver will need those to generate ARP
@@ -27,6 +31,7 @@ type PlatformSpecificParams struct {
 func defaultPlatformSpecificParams() PlatformSpecificParams {
 	return PlatformSpecificParams{
 		ComponentID: "tap0901",
+		InterfaceName: "",
 		Network:     "192.168.1.10/24",
 	}
 }

syscalls_bsd.go

@@ -0,0 +1,35 @@
+// +build openbsd freebsd netbsd dragonfly
+
+package water
+
+import (
+	"os"
+)
+
+func newTAP(config Config) (ifce *Interface, err error) {
+	if config.Name[:8] != "/dev/tap" {
+		panic("TUN/TAP name must be in format /dev/tunX or /dev/tapX")
+	}
+
+	file, err := os.OpenFile(config.Name, os.O_RDWR, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	ifce = &Interface{isTAP: true, ReadWriteCloser: file, name: config.Name[5:]}
+	return
+}
+
+func newTUN(config Config) (ifce *Interface, err error) {
+	if config.Name[:8] != "/dev/tun" {
+		panic("TUN/TAP name must be in format /dev/tunX or /dev/tapX")
+	}
+
+	file, err := os.OpenFile(config.Name, os.O_RDWR, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	ifce = &Interface{isTAP: false, ReadWriteCloser: file, name: config.Name[5:]}
+	return
+}

syscalls_other.go

@@ -1,4 +1,4 @@
-// +build !linux,!darwin,!windows
+// +build !linux,!darwin,!windows,!openbsd,!freebsd,!netbsd,!dragonfly
 
 package water
 

syscalls_windows.go

@@ -140,7 +140,7 @@ func tap_control_code(request, method uint32) uint32 {
 }
 
 // getdeviceid finds out a TAP device from registry, it *may* requires privileged right to prevent some weird issue.
-func getdeviceid(componentID string) (deviceid string, err error) {
+func getdeviceid(componentID string, interfaceName string) (deviceid string, err error) {
 	// TAP driver key location
 	regkey := `SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}`
 	k, err := registry.OpenKey(registry.LOCAL_MACHINE, regkey, registry.READ)
@@ -170,12 +170,33 @@ func getdeviceid(componentID string) (deviceid string, err error) {
 				key.Close()
 				continue
 			}
+			if len(interfaceName) > 0 {
+				key2 := `SYSTEM\CurrentControlSet\Control\Network\{4D36E972-E325-11CE-BFC1-08002BE10318}\`+val+`\Connection`
+				k2, err := registry.OpenKey(registry.LOCAL_MACHINE, key2, registry.READ)
+				if err != nil {
+					fmt.Println("Unable to open", key2)
+					continue
+				}
+				defer k2.Close()
+				val, _, err := k2.GetStringValue("Name")
+				if err != nil {
+					fmt.Println("Unable to get Name value from", key2)
+					continue
+				}
+				if val != interfaceName {
+					continue
+				}
+			}
 			key.Close()
 			return val, nil
 		}
 		key.Close()
 	}
-	return "", fmt.Errorf("Failed to find the tap device in registry with specified ComponentId(%s), TAP driver may be not installed", componentID)
+	if len(interfaceName) > 0 {
+		return "", fmt.Errorf("Failed to find the tap device in registry with specified ComponentId '%s' and InterfaceName '%s', TAP driver may be not installed or you may have specified an interface name that doesn't exist", componentID)
+	} else {
+		return "", fmt.Errorf("Failed to find the tap device in registry with specified ComponentId '%s', TAP driver may be not installed", componentID)
+	}
 }
 
 // setStatus is used to bring up or bring down the interface
@@ -217,7 +238,7 @@ func setTUN(fd syscall.Handle, network string) error {
 // openDev find and open an interface.
 func openDev(config Config) (ifce *Interface, err error) {
 	// find the device in registry.
-	deviceid, err := getdeviceid(config.PlatformSpecificParams.ComponentID)
+	deviceid, err := getdeviceid(config.PlatformSpecificParams.ComponentID, config.PlatformSpecificParams.InterfaceName)
 	if err != nil {
 		return nil, err
 	}