Handle peer interface config change (#348)

Before this change, NetBird Agent wasn't handling
peer interface configuration changes dynamically.
Also, remote peer configuration changes have
not been applied (e.g. AllowedIPs changed).
Not a very common cause, but still it should be handled.
Now, Agent reacts to PeerConfig changes sent from the
management service and restarts remote connections
if AllowedIps have been changed.

client/internal/engine.go

@@ -78,7 +78,7 @@ type Engine struct {
 
 	ctx context.Context
 
-	wgInterface iface.WGIface
+	wgInterface *iface.WGIface
 
 	udpMux          ice.UDPMux
 	udpMuxSrflx     ice.UniversalUDPMux
@@ -177,7 +177,7 @@ func (e *Engine) Start() error {
 	myPrivateKey := e.config.WgPrivateKey
 	var err error
 
-	e.wgInterface, err = iface.NewWGIface(wgIfaceName, wgAddr, iface.DefaultMTU)
+	e.wgInterface, err = iface.NewWGIFace(wgIfaceName, wgAddr, iface.DefaultMTU)
 	if err != nil {
 		log.Errorf("failed creating wireguard interface instance %s: [%s]", wgIfaceName, err.Error())
 		return err
@@ -216,7 +216,39 @@ func (e *Engine) Start() error {
 	return nil
 }
 
-// removePeers finds and removes peers that do not exist anymore in the network map received from the Management Service
+// modifyPeers updates peers that have been modified (e.g. IP address has been changed).
+// It closes the existing connection, removes it from the peerConns map, and creates a new one.
+func (e *Engine) modifyPeers(peersUpdate []*mgmProto.RemotePeerConfig) error {
+
+	// first, check if peers have been modified
+	var modified []*mgmProto.RemotePeerConfig
+	for _, p := range peersUpdate {
+		if peerConn, ok := e.peerConns[p.GetWgPubKey()]; ok {
+			if peerConn.GetConf().ProxyConfig.AllowedIps != strings.Join(p.AllowedIps, ",") {
+				modified = append(modified, p)
+			}
+		}
+	}
+
+	// second, close all modified connections and remove them from the state map
+	for _, p := range modified {
+		err := e.removePeer(p.GetWgPubKey())
+		if err != nil {
+			return err
+		}
+	}
+	// third, add the peer connections again
+	for _, p := range modified {
+		err := e.addNewPeer(p)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// removePeers finds and removes peers that do not exist anymore in the network map received from the Management Service.
+// It also removes peers that have been modified (e.g. change of IP address). They will be added again in addPeers method.
 func (e *Engine) removePeers(peersUpdate []*mgmProto.RemotePeerConfig) error {
 	currentPeers := make([]string, 0, len(e.peerConns))
 	for p := range e.peerConns {
@@ -366,6 +398,12 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 	}
 
 	if update.GetNetworkMap() != nil {
+		if update.GetNetworkMap().GetPeerConfig() != nil {
+			err := e.updateConfig(update.GetNetworkMap().GetPeerConfig())
+			if err != nil {
+				return err
+			}
+		}
 		// only apply new changes and ignore old ones
 		err := e.updateNetworkMap(update.GetNetworkMap())
 		if err != nil {
@@ -376,6 +414,20 @@ func (e *Engine) handleSync(update *mgmProto.SyncResponse) error {
 	return nil
 }
 
+func (e *Engine) updateConfig(conf *mgmProto.PeerConfig) error {
+	if e.wgInterface.Address.String() != conf.Address {
+		oldAddr := e.wgInterface.Address.String()
+		log.Debugf("updating peer address from %s to %s", oldAddr, conf.Address)
+		err := e.wgInterface.UpdateAddr(conf.Address)
+		if err != nil {
+			return err
+		}
+		log.Infof("updated peer address from %s to %s", oldAddr, conf.Address)
+	}
+
+	return nil
+}
+
 // receiveManagementEvents connects to the Management Service event stream to receive updates from the management service
 // E.g. when a new peer has been registered and we are allowed to connect to it.
 func (e *Engine) receiveManagementEvents() {
@@ -454,6 +506,11 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap) error {
 			return err
 		}
 
+		err = e.modifyPeers(networkMap.GetRemotePeers())
+		if err != nil {
+			return err
+		}
+
 		err = e.addNewPeers(networkMap.GetRemotePeers())
 		if err != nil {
 			return err
@@ -464,11 +521,21 @@ func (e *Engine) updateNetworkMap(networkMap *mgmProto.NetworkMap) error {
 	return nil
 }
 
-// addNewPeers finds and adds peers that were not know before but arrived from the Management service with the update
+// addNewPeers adds peers that were not know before but arrived from the Management service with the update
 func (e *Engine) addNewPeers(peersUpdate []*mgmProto.RemotePeerConfig) error {
 	for _, p := range peersUpdate {
-		peerKey := p.GetWgPubKey()
-		peerIPs := p.GetAllowedIps()
+		err := e.addNewPeer(p)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// addNewPeer add peer if connection doesn't exist
+func (e *Engine) addNewPeer(peerConfig *mgmProto.RemotePeerConfig) error {
+	peerKey := peerConfig.GetWgPubKey()
+	peerIPs := peerConfig.GetAllowedIps()
 	if _, ok := e.peerConns[peerKey]; !ok {
 		conn, err := e.createPeerConn(peerKey, strings.Join(peerIPs, ","))
 		if err != nil {
@@ -478,8 +545,6 @@ func (e *Engine) addNewPeers(peersUpdate []*mgmProto.RemotePeerConfig) error {
 
 		go e.connWorker(conn, peerKey)
 	}
-
-	}
 	return nil
 }
 
@@ -505,6 +570,12 @@ func (e Engine) connWorker(conn *peer.Conn, peerKey string) {
 		err := conn.Open()
 		if err != nil {
 			log.Debugf("connection to peer %s failed: %v", peerKey, err)
+			switch err.(type) {
+			case *peer.ConnectionClosedError:
+				// conn has been forced to close, so we exit the loop
+				return
+			default:
+			}
 		}
 	}
 }

client/internal/engine_test.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -62,7 +63,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 		networkMap *mgmtProto.NetworkMap
 
 		expectedLen    int
-		expectedPeers  []string
+		expectedPeers  []*mgmtProto.RemotePeerConfig
 		expectedSerial uint64
 	}
 
@@ -81,6 +82,11 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 		AllowedIps: []string{"100.64.0.12/24"},
 	}
 
+	modifiedPeer3 := &mgmtProto.RemotePeerConfig{
+		WgPubKey:   "GGHf3Ma6z6mdLbriAJbqhX7+nM/B71lgw2+91q3LfhU=",
+		AllowedIps: []string{"100.64.0.20/24"},
+	}
+
 	case1 := testCase{
 		name: "input with a new peer to add",
 		networkMap: &mgmtProto.NetworkMap{
@@ -92,7 +98,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 			RemotePeersIsEmpty: false,
 		},
 		expectedLen:    1,
-		expectedPeers:  []string{peer1.GetWgPubKey()},
+		expectedPeers:  []*mgmtProto.RemotePeerConfig{peer1},
 		expectedSerial: 1,
 	}
 
@@ -108,7 +114,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 			RemotePeersIsEmpty: false,
 		},
 		expectedLen:    2,
-		expectedPeers:  []string{peer1.GetWgPubKey(), peer2.GetWgPubKey()},
+		expectedPeers:  []*mgmtProto.RemotePeerConfig{peer1, peer2},
 		expectedSerial: 2,
 	}
 
@@ -123,7 +129,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 			RemotePeersIsEmpty: false,
 		},
 		expectedLen:    2,
-		expectedPeers:  []string{peer1.GetWgPubKey(), peer2.GetWgPubKey()},
+		expectedPeers:  []*mgmtProto.RemotePeerConfig{peer1, peer2},
 		expectedSerial: 2,
 	}
 
@@ -138,11 +144,26 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 			RemotePeersIsEmpty: false,
 		},
 		expectedLen:    2,
-		expectedPeers:  []string{peer2.GetWgPubKey(), peer3.GetWgPubKey()},
+		expectedPeers:  []*mgmtProto.RemotePeerConfig{peer2, peer3},
 		expectedSerial: 4,
 	}
 
 	case5 := testCase{
+		name: "input with one peer to modify",
+		networkMap: &mgmtProto.NetworkMap{
+			Serial:     4,
+			PeerConfig: nil,
+			RemotePeers: []*mgmtProto.RemotePeerConfig{
+				modifiedPeer3, peer2,
+			},
+			RemotePeersIsEmpty: false,
+		},
+		expectedLen:    2,
+		expectedPeers:  []*mgmtProto.RemotePeerConfig{peer2, modifiedPeer3},
+		expectedSerial: 4,
+	}
+
+	case6 := testCase{
 		name: "input with all peers to remove",
 		networkMap: &mgmtProto.NetworkMap{
 			Serial:             5,
@@ -155,7 +176,7 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 		expectedSerial: 5,
 	}
 
-	for _, c := range []testCase{case1, case2, case3, case4, case5} {
+	for _, c := range []testCase{case1, case2, case3, case4, case5, case6} {
 		t.Run(c.name, func(t *testing.T) {
 			err = engine.updateNetworkMap(c.networkMap)
 			if err != nil {
@@ -172,9 +193,15 @@ func TestEngine_UpdateNetworkMap(t *testing.T) {
 			}
 
 			for _, p := range c.expectedPeers {
-				if _, ok := engine.peerConns[p]; !ok {
+				conn, ok := engine.peerConns[p.GetWgPubKey()]
+				if !ok {
 					t.Errorf("expecting Engine.peerConns to contain peer %s", p)
 				}
+				expectedAllowedIPs := strings.Join(p.AllowedIps, ",")
+				if conn.GetConf().ProxyConfig.AllowedIps != expectedAllowedIPs {
+					t.Errorf("expecting peer %s to have AllowedIPs= %s, got %s", p.GetWgPubKey(),
+						expectedAllowedIPs, conn.GetConf().ProxyConfig.AllowedIps)
+				}
 			}
 		})
 	}

client/internal/peer/conn.go

@@ -66,6 +66,11 @@ type Conn struct {
 	proxy proxy.Proxy
 }
 
+// GetConf returns the connection config
+func (conn *Conn) GetConf() ConnConfig {
+	return conn.config
+}
+
 // NewConn creates a new not opened Conn to the remote peer.
 // To establish a connection run Conn.Open
 func NewConn(config ConnConfig) (*Conn, error) {
@@ -437,7 +442,7 @@ func (conn *Conn) Close() error {
 		// before conn.Open() another update from management arrives with peers: [1,2,3,4,5]
 		// engine adds a new Conn for 4 and 5
 		// therefore peer 4 has 2 Conn objects
-		log.Warnf("closing not started coonection %s", conn.config.Key)
+		log.Warnf("connection has been already closed or attempted closing not started coonection %s", conn.config.Key)
 		return NewConnectionAlreadyClosed(conn.config.Key)
 	}
 }

client/internal/proxy/proxy.go

@@ -21,7 +21,7 @@ const (
 type Config struct {
 	WgListenAddr string
 	RemoteKey    string
-	WgInterface  iface.WGIface
+	WgInterface  *iface.WGIface
 	AllowedIps   string
 	PreSharedKey *wgtypes.Key
 }

iface/configuration.go

@@ -30,6 +30,8 @@ func (w *WGIface) configureDevice(config wgtypes.Config) error {
 // Configure configures a Wireguard interface
 // The interface must exist before calling this method (e.g. call interface.Create() before)
 func (w *WGIface) Configure(privateKey string, port int) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
 
 	log.Debugf("configuring Wireguard interface %s", w.Name)
 
@@ -76,6 +78,8 @@ func (w *WGIface) GetListenPort() (*int, error) {
 // UpdatePeer updates existing Wireguard Peer or creates a new one if doesn't exist
 // Endpoint is optional
 func (w *WGIface) UpdatePeer(peerKey string, allowedIps string, keepAlive time.Duration, endpoint *net.UDPAddr, preSharedKey *wgtypes.Key) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
 
 	log.Debugf("updating interface %s peer %s: endpoint %s ", w.Name, peerKey, endpoint)
 
@@ -110,6 +114,9 @@ func (w *WGIface) UpdatePeer(peerKey string, allowedIps string, keepAlive time.D
 
 // RemovePeer removes a Wireguard Peer from the interface iface
 func (w *WGIface) RemovePeer(peerKey string) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
 	log.Debugf("Removing peer %s from interface %s ", peerKey, w.Name)
 
 	peerKeyParsed, err := wgtypes.ParseKey(peerKey)

iface/iface.go

@@ -1,10 +1,11 @@
 package iface
 
 import (
-	"golang.zx2c4.com/wireguard/wgctrl"
+	"fmt"
 	"net"
 	"os"
 	"runtime"
+	"sync"
 )
 
 const (
@@ -19,6 +20,7 @@ type WGIface struct {
 	MTU       int
 	Address   WGAddress
 	Interface NetInterface
+	mu        sync.Mutex
 }
 
 // WGAddress Wireguard parsed address
@@ -27,16 +29,22 @@ type WGAddress struct {
 	Network *net.IPNet
 }
 
+func (addr *WGAddress) String() string {
+	maskSize, _ := addr.Network.Mask.Size()
+	return fmt.Sprintf("%s/%d", addr.IP.String(), maskSize)
+}
+
 // NetInterface represents a generic network tunnel interface
 type NetInterface interface {
 	Close() error
 }
 
-// NewWGIface Creates a new Wireguard interface instance
-func NewWGIface(iface string, address string, mtu int) (WGIface, error) {
-	wgIface := WGIface{
+// NewWGIFace Creates a new Wireguard interface instance
+func NewWGIFace(iface string, address string, mtu int) (*WGIface, error) {
+	wgIface := &WGIface{
 		Name: iface,
 		MTU:  mtu,
+		mu:   sync.Mutex{},
 	}
 
 	wgAddress, err := parseAddress(address)
@@ -49,30 +57,6 @@ func NewWGIface(iface string, address string, mtu int) (WGIface, error) {
 	return wgIface, nil
 }
 
-// Exists checks whether specified Wireguard device exists or not
-func Exists(iface string) (*bool, error) {
-	wg, err := wgctrl.New()
-	if err != nil {
-		return nil, err
-	}
-	defer wg.Close()
-
-	devices, err := wg.Devices()
-	if err != nil {
-		return nil, err
-	}
-
-	var exists bool
-	for _, d := range devices {
-		if d.Name == iface {
-			exists = true
-			return &exists, nil
-		}
-	}
-	exists = false
-	return &exists, nil
-}
-
 // parseAddress parse a string ("1.2.3.4/24") address to WG Address
 func parseAddress(address string) (WGAddress, error) {
 	ip, network, err := net.ParseCIDR(address)
@@ -85,8 +69,10 @@ func parseAddress(address string) (WGAddress, error) {
 	}, nil
 }
 
-// Closes the tunnel interface
+// Close closes the tunnel interface
 func (w *WGIface) Close() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
 
 	err := w.Interface.Close()
 	if err != nil {

iface/iface_darwin.go

@@ -7,7 +7,10 @@ import (
 
 // Create Creates a new Wireguard interface, sets a given IP and brings it up.
 func (w *WGIface) Create() error {
-	return w.CreateWithUserspace()
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	return w.createWithUserspace()
 }
 
 // assignAddr Adds IP address to the tunnel interface and network route based on the range provided

iface/iface_linux.go

@@ -2,7 +2,6 @@ package iface
 
 import (
 	"errors"
-	"fmt"
 	"math"
 	"os"
 	"syscall"
@@ -33,22 +32,24 @@ func WireguardModExists() bool {
 	return errors.Is(err, syscall.EINVAL)
 }
 
-// Create Creates a new Wireguard interface, sets a given IP and brings it up.
+// Create creates a new Wireguard interface, sets a given IP and brings it up.
 // Will reuse an existing one.
 func (w *WGIface) Create() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
 
 	if WireguardModExists() {
 		log.Info("using kernel WireGuard")
-		return w.CreateWithKernel()
+		return w.createWithKernel()
 	} else {
 		log.Info("using userspace WireGuard")
-		return w.CreateWithUserspace()
+		return w.createWithUserspace()
 	}
 }
 
-// CreateWithKernel Creates a new Wireguard interface using kernel Wireguard module.
+// createWithKernel Creates a new Wireguard interface using kernel Wireguard module.
 // Works for Linux and offers much better network performance
-func (w *WGIface) CreateWithKernel() error {
+func (w *WGIface) createWithKernel() error {
 
 	link := newWGLink(w.Name)
 
@@ -106,10 +107,6 @@ func (w *WGIface) CreateWithKernel() error {
 
 // assignAddr Adds IP address to the tunnel interface
 func (w *WGIface) assignAddr() error {
-
-	mask, _ := w.Address.Network.Mask.Size()
-	address := fmt.Sprintf("%s/%d", w.Address.IP.String(), mask)
-
 	link := newWGLink(w.Name)
 
 	//delete existing addresses
@@ -126,11 +123,11 @@ func (w *WGIface) assignAddr() error {
 		}
 	}
 
-	log.Debugf("adding address %s to interface: %s", address, w.Name)
-	addr, _ := netlink.ParseAddr(address)
+	log.Debugf("adding address %s to interface: %s", w.Address.String(), w.Name)
+	addr, _ := netlink.ParseAddr(w.Address.String())
 	err = netlink.AddrAdd(link, addr)
 	if os.IsExist(err) {
-		log.Infof("interface %s already has the address: %s", w.Name, address)
+		log.Infof("interface %s already has the address: %s", w.Name, w.Address.String())
 	} else if err != nil {
 		return err
 	}

iface/iface_test.go

@@ -3,6 +3,7 @@ package iface
 import (
 	"fmt"
 	log "github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
 	"golang.zx2c4.com/wireguard/wgctrl"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 	"net"
@@ -28,11 +29,71 @@ func init() {
 	peerPubKey = peerPrivateKey.PublicKey().String()
 }
 
+func TestWGIface_UpdateAddr(t *testing.T) {
+	ifaceName := fmt.Sprintf("utun%d", WgIntNumber+4)
+	addr := "100.64.0.1/8"
+	iface, err := NewWGIFace(ifaceName, addr, DefaultMTU)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = iface.Create()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		err = iface.Close()
+		if err != nil {
+			t.Error(err)
+		}
+	}()
+	port, err := iface.GetListenPort()
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = iface.Configure(key, *port)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	addrs, err := getIfaceAddrs(ifaceName)
+	if err != nil {
+		t.Error(err)
+	}
+	assert.Equal(t, addr, addrs[0].String())
+
+	//update WireGuard address
+	addr = "100.64.0.2/8"
+	err = iface.UpdateAddr(addr)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	addrs, err = getIfaceAddrs(ifaceName)
+	if err != nil {
+		t.Error(err)
+	}
+
+	assert.Equal(t, addr, addrs[0].String())
+
+}
+
+func getIfaceAddrs(ifaceName string) ([]net.Addr, error) {
+	ief, err := net.InterfaceByName(ifaceName)
+	if err != nil {
+		return nil, err
+	}
+	addrs, err := ief.Addrs()
+	if err != nil {
+		return nil, err
+	}
+	return addrs, nil
+}
+
 //
 func Test_CreateInterface(t *testing.T) {
 	ifaceName := fmt.Sprintf("utun%d", WgIntNumber+1)
 	wgIP := "10.99.99.1/32"
-	iface, err := NewWGIface(ifaceName, wgIP, DefaultMTU)
+	iface, err := NewWGIFace(ifaceName, wgIP, DefaultMTU)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -61,7 +122,7 @@ func Test_CreateInterface(t *testing.T) {
 func Test_Close(t *testing.T) {
 	ifaceName := fmt.Sprintf("utun%d", WgIntNumber+2)
 	wgIP := "10.99.99.2/32"
-	iface, err := NewWGIface(ifaceName, wgIP, DefaultMTU)
+	iface, err := NewWGIFace(ifaceName, wgIP, DefaultMTU)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -89,7 +150,7 @@ func Test_Close(t *testing.T) {
 func Test_ConfigureInterface(t *testing.T) {
 	ifaceName := fmt.Sprintf("utun%d", WgIntNumber+3)
 	wgIP := "10.99.99.5/30"
-	iface, err := NewWGIface(ifaceName, wgIP, DefaultMTU)
+	iface, err := NewWGIFace(ifaceName, wgIP, DefaultMTU)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -136,7 +197,7 @@ func Test_ConfigureInterface(t *testing.T) {
 func Test_UpdatePeer(t *testing.T) {
 	ifaceName := fmt.Sprintf("utun%d", WgIntNumber+4)
 	wgIP := "10.99.99.9/30"
-	iface, err := NewWGIface(ifaceName, wgIP, DefaultMTU)
+	iface, err := NewWGIFace(ifaceName, wgIP, DefaultMTU)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -195,7 +256,7 @@ func Test_UpdatePeer(t *testing.T) {
 func Test_RemovePeer(t *testing.T) {
 	ifaceName := fmt.Sprintf("utun%d", WgIntNumber+4)
 	wgIP := "10.99.99.13/30"
-	iface, err := NewWGIface(ifaceName, wgIP, DefaultMTU)
+	iface, err := NewWGIFace(ifaceName, wgIP, DefaultMTU)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -247,7 +308,7 @@ func Test_ConnectPeers(t *testing.T) {
 
 	keepAlive := 1 * time.Second
 
-	iface1, err := NewWGIface(peer1ifaceName, peer1wgIP, DefaultMTU)
+	iface1, err := NewWGIFace(peer1ifaceName, peer1wgIP, DefaultMTU)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -264,7 +325,7 @@ func Test_ConnectPeers(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	iface2, err := NewWGIface(peer2ifaceName, peer2wgIP, DefaultMTU)
+	iface2, err := NewWGIFace(peer2ifaceName, peer2wgIP, DefaultMTU)
 	if err != nil {
 		t.Fatal(err)
 	}

iface/iface_unix.go

@@ -12,8 +12,8 @@ import (
 	"net"
 )
 
-// CreateWithUserspace Creates a new Wireguard interface, using wireguard-go userspace implementation
-func (w *WGIface) CreateWithUserspace() error {
+// createWithUserspace Creates a new Wireguard interface, using wireguard-go userspace implementation
+func (w *WGIface) createWithUserspace() error {
 
 	tunIface, err := tun.CreateTUN(w.Name, w.MTU)
 	if err != nil {
@@ -61,3 +61,17 @@ func getUAPI(iface string) (net.Listener, error) {
 	}
 	return ipc.UAPIListen(iface, tunSock)
 }
+
+// UpdateAddr updates address of the interface
+func (w *WGIface) UpdateAddr(newAddr string) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	addr, err := parseAddress(newAddr)
+	if err != nil {
+		return err
+	}
+
+	w.Address = addr
+	return w.assignAddr()
+}

iface/iface_windows.go

@@ -11,6 +11,8 @@ import (
 
 // Create Creates a new Wireguard interface, sets a given IP and brings it up.
 func (w *WGIface) Create() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
 
 	WintunStaticRequestedGUID, _ := windows.GenerateGUID()
 	adapter, err := driver.CreateAdapter(w.Name, "WireGuard", &WintunStaticRequestedGUID)
@@ -40,3 +42,18 @@ func (w *WGIface) assignAddr(luid winipcfg.LUID) error {
 
 	return nil
 }
+
+// UpdateAddr updates address of the interface
+func (w *WGIface) UpdateAddr(newAddr string) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	luid := w.Interface.(*driver.Adapter).LUID()
+	addr, err := parseAddress(newAddr)
+	if err != nil {
+		return err
+	}
+
+	w.Address = addr
+	return w.assignAddr(luid)
+}

management/server/grpcserver.go

@@ -29,9 +29,6 @@ type Server struct {
 	jwtMiddleware          *middleware.JWTMiddleware
 }
 
-// AllowedIPsFormat generates Wireguard AllowedIPs format (e.g. 100.30.30.1/32)
-const AllowedIPsFormat = "%s/32"
-
 // NewServer creates a new Management server
 func NewServer(config *Config, accountManager AccountManager, peersUpdateManager *PeersUpdateManager, turnCredentialsManager TURNCredentialsManager) (*Server, error) {
 	key, err := wgtypes.GeneratePrivateKey()
@@ -227,7 +224,7 @@ func (s *Server) registerPeer(peerKey wgtypes.Key, req *proto.LoginRequest) (*Pe
 				peersToSend = append(peersToSend, p)
 			}
 		}
-		update := toSyncResponse(s.config, peer, peersToSend, nil, networkMap.Network.CurrentSerial())
+		update := toSyncResponse(s.config, remotePeer, peersToSend, nil, networkMap.Network.CurrentSerial())
 		err = s.peersUpdateManager.SendUpdate(remotePeer.Key, &UpdateMessage{Update: update})
 		if err != nil {
 			// todo rethink if we should keep this return
@@ -368,7 +365,7 @@ func toWiretrusteeConfig(config *Config, turnCredentials *TURNCredentials) *prot
 
 func toPeerConfig(peer *Peer) *proto.PeerConfig {
 	return &proto.PeerConfig{
-		Address: peer.IP.String() + "/16", // todo make it explicit
+		Address: fmt.Sprintf("%s/%d", peer.IP.String(), SubnetSize), // take it from the network
 	}
 }
 
@@ -377,7 +374,7 @@ func toRemotePeerConfig(peers []*Peer) []*proto.RemotePeerConfig {
 	for _, rPeer := range peers {
 		remotePeers = append(remotePeers, &proto.RemotePeerConfig{
 			WgPubKey:   rPeer.Key,
-			AllowedIps: []string{fmt.Sprintf(AllowedIPsFormat, rPeer.IP)}, // todo /32
+			AllowedIps: []string{fmt.Sprintf(AllowedIPsFormat, rPeer.IP)},
 		})
 	}
 

management/server/network.go

@@ -11,6 +11,16 @@ import (
 	"time"
 )
 
+const (
+	// SubnetSize is a size of the subnet of the global network, e.g.  100.77.0.0/16
+	SubnetSize = 16
+	// NetSize is a global network size 100.64.0.0/10
+	NetSize = 10
+
+	// AllowedIPsFormat generates Wireguard AllowedIPs format (e.g. 100.64.30.1/32)
+	AllowedIPsFormat = "%s/32"
+)
+
 type NetworkMap struct {
 	Peers   []*Peer
 	Network *Network
@@ -31,8 +41,8 @@ type Network struct {
 // It takes a random /16 subnet from 100.64.0.0/10 (64 different subnets)
 func NewNetwork() *Network {
 
-	n := iplib.NewNet4(net.ParseIP("100.64.0.0"), 10)
-	sub, _ := n.Subnet(16)
+	n := iplib.NewNet4(net.ParseIP("100.64.0.0"), NetSize)
+	sub, _ := n.Subnet(SubnetSize)
 
 	s := rand.NewSource(time.Now().Unix())
 	r := rand.New(s)