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

util/wsproxy/client/dialer_js.go

@@ -0,0 +1,171 @@
+package client
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"sync"
+	"syscall/js"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	"google.golang.org/grpc"
+
+	"github.com/netbirdio/netbird/util/wsproxy"
+)
+
+const dialTimeout = 30 * time.Second
+
+// websocketConn wraps a JavaScript WebSocket to implement net.Conn
+type websocketConn struct {
+	ws         js.Value
+	remoteAddr string
+	messages   chan []byte
+	readBuf    []byte
+	ctx        context.Context
+	cancel     context.CancelFunc
+	mu         sync.Mutex
+}
+
+func (c *websocketConn) Read(b []byte) (int, error) {
+	c.mu.Lock()
+	if len(c.readBuf) > 0 {
+		n := copy(b, c.readBuf)
+		c.readBuf = c.readBuf[n:]
+		c.mu.Unlock()
+		return n, nil
+	}
+	c.mu.Unlock()
+
+	select {
+	case data := <-c.messages:
+		n := copy(b, data)
+		if n < len(data) {
+			c.mu.Lock()
+			c.readBuf = data[n:]
+			c.mu.Unlock()
+		}
+		return n, nil
+	case <-c.ctx.Done():
+		return 0, c.ctx.Err()
+	}
+}
+
+func (c *websocketConn) Write(b []byte) (int, error) {
+	select {
+	case <-c.ctx.Done():
+		return 0, c.ctx.Err()
+	default:
+	}
+
+	uint8Array := js.Global().Get("Uint8Array").New(len(b))
+	js.CopyBytesToJS(uint8Array, b)
+	c.ws.Call("send", uint8Array)
+	return len(b), nil
+}
+
+func (c *websocketConn) Close() error {
+	c.cancel()
+	c.ws.Call("close")
+	return nil
+}
+
+func (c *websocketConn) LocalAddr() net.Addr {
+	return nil
+}
+
+func (c *websocketConn) RemoteAddr() net.Addr {
+	return stringAddr(c.remoteAddr)
+}
+func (c *websocketConn) SetDeadline(t time.Time) error {
+	return nil
+}
+
+func (c *websocketConn) SetReadDeadline(t time.Time) error {
+	return nil
+}
+
+func (c *websocketConn) SetWriteDeadline(t time.Time) error {
+	return nil
+}
+
+// stringAddr is a simple net.Addr that returns a string
+type stringAddr string
+
+func (s stringAddr) Network() string { return "tcp" }
+func (s stringAddr) String() string  { return string(s) }
+
+// WithWebSocketDialer returns a gRPC dial option that uses WebSocket transport for JS/WASM environments.
+func WithWebSocketDialer(tlsEnabled bool) grpc.DialOption {
+	return grpc.WithContextDialer(func(ctx context.Context, addr string) (net.Conn, error) {
+		scheme := "wss"
+		if !tlsEnabled {
+			scheme = "ws"
+		}
+		wsURL := fmt.Sprintf("%s://%s%s", scheme, addr, wsproxy.ProxyPath)
+
+		ws := js.Global().Get("WebSocket").New(wsURL)
+
+		connCtx, connCancel := context.WithCancel(context.Background())
+		conn := &websocketConn{
+			ws:         ws,
+			remoteAddr: addr,
+			messages:   make(chan []byte, 100),
+			ctx:        connCtx,
+			cancel:     connCancel,
+		}
+
+		ws.Set("binaryType", "arraybuffer")
+
+		openCh := make(chan struct{})
+		errorCh := make(chan error, 1)
+
+		ws.Set("onopen", js.FuncOf(func(this js.Value, args []js.Value) any {
+			close(openCh)
+			return nil
+		}))
+
+		ws.Set("onerror", js.FuncOf(func(this js.Value, args []js.Value) any {
+			select {
+			case errorCh <- wsproxy.ErrConnectionFailed:
+			default:
+			}
+			return nil
+		}))
+
+		ws.Set("onmessage", js.FuncOf(func(this js.Value, args []js.Value) any {
+			event := args[0]
+			data := event.Get("data")
+
+			uint8Array := js.Global().Get("Uint8Array").New(data)
+			length := uint8Array.Get("length").Int()
+			bytes := make([]byte, length)
+			js.CopyBytesToGo(bytes, uint8Array)
+
+			select {
+			case conn.messages <- bytes:
+			default:
+				log.Warnf("gRPC WebSocket message dropped for %s - buffer full", addr)
+			}
+			return nil
+		}))
+
+		ws.Set("onclose", js.FuncOf(func(this js.Value, args []js.Value) any {
+			conn.cancel()
+			return nil
+		}))
+
+		select {
+		case <-openCh:
+			return conn, nil
+		case err := <-errorCh:
+			return nil, err
+		case <-ctx.Done():
+			ws.Call("close")
+			return nil, ctx.Err()
+		case <-time.After(dialTimeout):
+			ws.Call("close")
+			return nil, wsproxy.ErrConnectionTimeout
+		}
+	})
+}