Add openvpn and openconnect

transport/openconnect/device_system_stack.go

@@ -0,0 +1,105 @@
+//go:build with_gvisor
+
+package openconnect
+
+import (
+	"net/netip"
+
+	"github.com/sagernet/sing-tun/gtcpip/header"
+	"github.com/sagernet/sing/common/buf"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+var _ Device = (*systemStackDevice)(nil)
+
+type systemStackDevice struct {
+	*systemDevice
+	stackDevice *stackDevice
+}
+
+func newSystemStackDevice(options DeviceOptions) (*systemStackDevice, error) {
+	system, err := newSystemDevice(options)
+	if err != nil {
+		return nil, err
+	}
+	stackOptions := options
+	stackOptions.System = false
+	stackDevice, err := newStackDevice(stackOptions)
+	if err != nil {
+		system.Close()
+		return nil, err
+	}
+	return &systemStackDevice{
+		systemDevice: system,
+		stackDevice:  stackDevice,
+	}, nil
+}
+
+func (d *systemStackDevice) SetPacketWriter(writer PacketWriter) {
+	d.systemDevice.SetPacketWriter(writer)
+	d.stackDevice.SetPacketWriter(writer)
+}
+
+func (d *systemStackDevice) UpdateConfiguration(configuration Configuration) error {
+	err := d.systemDevice.UpdateConfiguration(configuration)
+	if err != nil {
+		return err
+	}
+	return d.stackDevice.UpdateConfiguration(configuration)
+}
+
+func (d *systemStackDevice) WriteInboundBuffers(packetBuffers []*buf.Buffer) error {
+	return d.systemDevice.processInboundBuffers(packetBuffers, d.writeBuffers)
+}
+
+func (d *systemStackDevice) writeBuffers(packetBuffers []*buf.Buffer) error {
+	addresses := d.systemDevice.configurationAddresses()
+	runStart := 0
+	runUsesSystemDevice := false
+	var writeErr error
+	for i, packetBuffer := range packetBuffers {
+		destination := packetDestination(packetBuffer.Bytes())
+		useSystemDevice := false
+		for _, prefix := range addresses {
+			if prefix.Contains(destination) {
+				useSystemDevice = true
+				break
+			}
+		}
+		if i > runStart && useSystemDevice != runUsesSystemDevice {
+			var err error
+			if runUsesSystemDevice {
+				err = d.systemDevice.writeBuffers(packetBuffers[runStart:i])
+			} else {
+				err = d.stackDevice.writeBuffers(packetBuffers[runStart:i])
+			}
+			writeErr = E.Errors(writeErr, err)
+			runStart = i
+		}
+		if i == runStart {
+			runUsesSystemDevice = useSystemDevice
+		}
+	}
+	if runStart == len(packetBuffers) {
+		return writeErr
+	}
+	if runUsesSystemDevice {
+		return E.Errors(writeErr, d.systemDevice.writeBuffers(packetBuffers[runStart:]))
+	}
+	return E.Errors(writeErr, d.stackDevice.writeBuffers(packetBuffers[runStart:]))
+}
+
+func packetDestination(packet []byte) netip.Addr {
+	switch header.IPVersion(packet) {
+	case header.IPv4Version:
+		return header.IPv4(packet).DestinationAddr()
+	case header.IPv6Version:
+		return header.IPv6(packet).DestinationAddr()
+	default:
+		return netip.Addr{}
+	}
+}
+
+func (d *systemStackDevice) Close() error {
+	return E.Errors(d.stackDevice.Close(), d.systemDevice.Close())
+}