[client] Add embeddable library (#3239)

client/internal/dns/service_memory.go

@@ -2,7 +2,6 @@ package dns
 
 import (
 	"fmt"
-	"math/big"
 	"net"
 	"sync"
 
@@ -10,6 +9,8 @@ import (
 	"github.com/google/gopacket/layers"
 	"github.com/miekg/dns"
 	log "github.com/sirupsen/logrus"
+
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 type ServiceViaMemory struct {
@@ -27,7 +28,7 @@ func NewServiceViaMemory(wgIface WGIface) *ServiceViaMemory {
 		wgInterface: wgIface,
 		dnsMux:      dns.NewServeMux(),
 
-		runtimeIP:   getLastIPFromNetwork(wgIface.Address().Network, 1),
+		runtimeIP:   nbnet.GetLastIPFromNetwork(wgIface.Address().Network, 1).String(),
 		runtimePort: defaultPort,
 	}
 	return s
@@ -118,22 +119,3 @@ func (s *ServiceViaMemory) filterDNSTraffic() (string, error) {
 
 	return filter.AddUDPPacketHook(false, net.ParseIP(s.runtimeIP), uint16(s.runtimePort), hook), nil
 }
-
-func getLastIPFromNetwork(network *net.IPNet, fromEnd int) string {
-	// Calculate the last IP in the CIDR range
-	var endIP net.IP
-	for i := 0; i < len(network.IP); i++ {
-		endIP = append(endIP, network.IP[i]|^network.Mask[i])
-	}
-
-	// convert to big.Int
-	endInt := big.NewInt(0)
-	endInt.SetBytes(endIP)
-
-	// subtract fromEnd from the last ip
-	fromEndBig := big.NewInt(int64(fromEnd))
-	resultInt := big.NewInt(0)
-	resultInt.Sub(endInt, fromEndBig)
-
-	return net.IP(resultInt.Bytes()).String()
-}

client/internal/dns/service_memory_test.go

@@ -3,6 +3,8 @@ package dns
 import (
 	"net"
 	"testing"
+
+	nbnet "github.com/netbirdio/netbird/util/net"
 )
 
 func TestGetLastIPFromNetwork(t *testing.T) {
@@ -23,7 +25,7 @@ func TestGetLastIPFromNetwork(t *testing.T) {
 			return
 		}
 
-		lastIP := getLastIPFromNetwork(ipnet, 1)
+		lastIP := nbnet.GetLastIPFromNetwork(ipnet, 1).String()
 		if lastIP != tt.ip {
 			t.Errorf("wrong IP address, expected %s: got %s", tt.ip, lastIP)
 		}

client/internal/engine.go

@@ -19,6 +19,7 @@ import (
 	"github.com/pion/ice/v3"
 	"github.com/pion/stun/v2"
 	log "github.com/sirupsen/logrus"
+	"golang.zx2c4.com/wireguard/tun/netstack"
 	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
 	"google.golang.org/protobuf/proto"
 
@@ -28,7 +29,7 @@ import (
 	"github.com/netbirdio/netbird/client/iface"
 	"github.com/netbirdio/netbird/client/iface/bind"
 	"github.com/netbirdio/netbird/client/iface/device"
-	"github.com/netbirdio/netbird/client/iface/netstack"
+	nbnetstack "github.com/netbirdio/netbird/client/iface/netstack"
 	"github.com/netbirdio/netbird/client/internal/acl"
 	"github.com/netbirdio/netbird/client/internal/dns"
 	"github.com/netbirdio/netbird/client/internal/dnsfwd"
@@ -724,7 +725,7 @@ func (e *Engine) updateSSH(sshConf *mgmProto.SSHConfig) error {
 			// start SSH server if it wasn't running
 			if isNil(e.sshServer) {
 				listenAddr := fmt.Sprintf("%s:%d", e.wgInterface.Address().IP.String(), nbssh.DefaultSSHPort)
-				if netstack.IsEnabled() {
+				if nbnetstack.IsEnabled() {
 					listenAddr = fmt.Sprintf("127.0.0.1:%d", nbssh.DefaultSSHPort)
 				}
 				// nil sshServer means it has not yet been started
@@ -1716,6 +1717,37 @@ func (e *Engine) updateDNSForwarder(enabled bool, domains []string) {
 	}
 }
 
+func (e *Engine) GetNet() (*netstack.Net, error) {
+	e.syncMsgMux.Lock()
+	intf := e.wgInterface
+	e.syncMsgMux.Unlock()
+	if intf == nil {
+		return nil, errors.New("wireguard interface not initialized")
+	}
+
+	nsnet := intf.GetNet()
+	if nsnet == nil {
+		return nil, errors.New("failed to get netstack")
+	}
+	return nsnet, nil
+}
+
+func (e *Engine) Address() (netip.Addr, error) {
+	e.syncMsgMux.Lock()
+	intf := e.wgInterface
+	e.syncMsgMux.Unlock()
+	if intf == nil {
+		return netip.Addr{}, errors.New("wireguard interface not initialized")
+	}
+
+	addr := e.wgInterface.Address()
+	ip, ok := netip.AddrFromSlice(addr.IP)
+	if !ok {
+		return netip.Addr{}, errors.New("failed to convert address to netip.Addr")
+	}
+	return ip.Unmap(), nil
+}
+
 // isChecksEqual checks if two slices of checks are equal.
 func isChecksEqual(checks []*mgmProto.Checks, oChecks []*mgmProto.Checks) bool {
 	for _, check := range checks {