[client,signal,management] Add browser client support (#4415)

client/iface/bind/relay_bind.go

@@ -0,0 +1,125 @@
+package bind
+
+import (
+	"context"
+	"net"
+	"net/netip"
+	"sync"
+
+	log "github.com/sirupsen/logrus"
+	"golang.zx2c4.com/wireguard/conn"
+
+	"github.com/netbirdio/netbird/client/iface/udpmux"
+)
+
+// RelayBindJS is a conn.Bind implementation for WebAssembly environments.
+// Do not limit to build only js, because we want to be able to run tests
+type RelayBindJS struct {
+	*conn.StdNetBind
+
+	recvChan         chan recvMessage
+	endpoints        map[netip.Addr]net.Conn
+	endpointsMu      sync.Mutex
+	activityRecorder *ActivityRecorder
+	ctx              context.Context
+	cancel           context.CancelFunc
+}
+
+func NewRelayBindJS() *RelayBindJS {
+	return &RelayBindJS{
+		recvChan:         make(chan recvMessage, 100),
+		endpoints:        make(map[netip.Addr]net.Conn),
+		activityRecorder: NewActivityRecorder(),
+	}
+}
+
+// Open creates a receive function for handling relay packets in WASM.
+func (s *RelayBindJS) Open(uport uint16) ([]conn.ReceiveFunc, uint16, error) {
+	log.Debugf("Open: creating receive function for port %d", uport)
+
+	s.ctx, s.cancel = context.WithCancel(context.Background())
+
+	receiveFn := func(bufs [][]byte, sizes []int, eps []conn.Endpoint) (int, error) {
+		select {
+		case <-s.ctx.Done():
+			return 0, net.ErrClosed
+		case msg, ok := <-s.recvChan:
+			if !ok {
+				return 0, net.ErrClosed
+			}
+			copy(bufs[0], msg.Buffer)
+			sizes[0] = len(msg.Buffer)
+			eps[0] = conn.Endpoint(msg.Endpoint)
+			return 1, nil
+		}
+	}
+
+	log.Debugf("Open: receive function created, returning port %d", uport)
+	return []conn.ReceiveFunc{receiveFn}, uport, nil
+}
+
+func (s *RelayBindJS) Close() error {
+	if s.cancel == nil {
+		return nil
+	}
+	log.Debugf("close RelayBindJS")
+	s.cancel()
+	return nil
+}
+
+func (s *RelayBindJS) ReceiveFromEndpoint(ctx context.Context, ep *Endpoint, buf []byte) {
+	select {
+	case <-s.ctx.Done():
+		return
+	case <-ctx.Done():
+		return
+	case s.recvChan <- recvMessage{ep, buf}:
+	}
+}
+
+// Send forwards packets through the relay connection for WASM.
+func (s *RelayBindJS) Send(bufs [][]byte, ep conn.Endpoint) error {
+	if ep == nil {
+		return nil
+	}
+
+	fakeIP := ep.DstIP()
+
+	s.endpointsMu.Lock()
+	relayConn, ok := s.endpoints[fakeIP]
+	s.endpointsMu.Unlock()
+
+	if !ok {
+		return nil
+	}
+
+	for _, buf := range bufs {
+		if _, err := relayConn.Write(buf); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (b *RelayBindJS) SetEndpoint(fakeIP netip.Addr, conn net.Conn) {
+	b.endpointsMu.Lock()
+	b.endpoints[fakeIP] = conn
+	b.endpointsMu.Unlock()
+}
+
+func (s *RelayBindJS) RemoveEndpoint(fakeIP netip.Addr) {
+	s.endpointsMu.Lock()
+	defer s.endpointsMu.Unlock()
+
+	delete(s.endpoints, fakeIP)
+}
+
+// GetICEMux returns the ICE UDPMux that was created and used by ICEBind
+func (s *RelayBindJS) GetICEMux() (*udpmux.UniversalUDPMuxDefault, error) {
+	return nil, ErrUDPMUXNotSupported
+}
+
+func (s *RelayBindJS) ActivityRecorder() *ActivityRecorder {
+	return s.activityRecorder
+}