Netstack (#1403)

Add netstack support for the agent to run it without privileges.

- use interface for tun device
- use common IPC for userspace WireGuard integration
- move udpmux creation and sharedsock to tun layer

iface/tun_netstack.go

@@ -0,0 +1,119 @@
+//go:build !android
+// +build !android
+
+package iface
+
+import (
+	"fmt"
+
+	"github.com/pion/transport/v3"
+	log "github.com/sirupsen/logrus"
+	"golang.zx2c4.com/wireguard/device"
+
+	"github.com/netbirdio/netbird/iface/bind"
+	"github.com/netbirdio/netbird/iface/netstack"
+)
+
+type tunNetstackDevice struct {
+	name          string
+	address       WGAddress
+	port          int
+	key           string
+	mtu           int
+	listenAddress string
+	iceBind       *bind.ICEBind
+
+	device     *device.Device
+	wrapper    *DeviceWrapper
+	nsTun      *netstack.NetStackTun
+	udpMux     *bind.UniversalUDPMuxDefault
+	configurer wgConfigurer
+}
+
+func newTunNetstackDevice(name string, address WGAddress, wgPort int, key string, mtu int, transportNet transport.Net, listenAddress string) wgTunDevice {
+	return &tunNetstackDevice{
+		name:          name,
+		address:       address,
+		port:          wgPort,
+		key:           key,
+		mtu:           mtu,
+		listenAddress: listenAddress,
+		iceBind:       bind.NewICEBind(transportNet),
+	}
+}
+
+func (t *tunNetstackDevice) Create() (wgConfigurer, error) {
+	log.Info("create netstack tun interface")
+	t.nsTun = netstack.NewNetStackTun(t.listenAddress, t.address.IP.String(), t.mtu)
+	tunIface, err := t.nsTun.Create()
+	if err != nil {
+		return nil, err
+	}
+	t.wrapper = newDeviceWrapper(tunIface)
+
+	t.device = device.NewDevice(
+		t.wrapper,
+		t.iceBind,
+		device.NewLogger(device.LogLevelSilent, "[netbird] "),
+	)
+
+	t.configurer = newWGUSPConfigurer(t.device, t.name)
+	err = t.configurer.configureInterface(t.key, t.port)
+	if err != nil {
+		_ = tunIface.Close()
+		return nil, err
+	}
+
+	log.Debugf("device has been created: %s", t.name)
+	return t.configurer, nil
+}
+
+func (t *tunNetstackDevice) Up() (*bind.UniversalUDPMuxDefault, error) {
+	if t.device == nil {
+		return nil, fmt.Errorf("device is not ready yet")
+	}
+
+	err := t.device.Up()
+	if err != nil {
+		return nil, err
+	}
+
+	udpMux, err := t.iceBind.GetICEMux()
+	if err != nil {
+		return nil, err
+	}
+	t.udpMux = udpMux
+	log.Debugf("netstack device is ready to use")
+	return udpMux, nil
+}
+
+func (t *tunNetstackDevice) UpdateAddr(WGAddress) error {
+	return nil
+}
+
+func (t *tunNetstackDevice) Close() error {
+	if t.configurer != nil {
+		t.configurer.close()
+	}
+
+	if t.device != nil {
+		t.device.Close()
+	}
+
+	if t.udpMux != nil {
+		return t.udpMux.Close()
+	}
+	return nil
+}
+
+func (t *tunNetstackDevice) WgAddress() WGAddress {
+	return t.address
+}
+
+func (t *tunNetstackDevice) DeviceName() string {
+	return t.name
+}
+
+func (t *tunNetstackDevice) Wrapper() *DeviceWrapper {
+	return t.wrapper
+}