rpc, p2p/simulations: use github.com/gorilla/websocket (ethereum#20289)

* rpc: improve codec abstraction

rpc.ServerCodec is an opaque interface. There was only one way to get a
codec using existing APIs: rpc.NewJSONCodec. This change exports
newCodec (as NewFuncCodec) and NewJSONCodec (as NewCodec). It also makes
all codec methods non-public to avoid showing internals in godoc.

While here, remove codec options in tests because they are not
supported anymore.

* p2p/simulations: use github.com/gorilla/websocket

This package was the last remaining user of golang.org/x/net/websocket.
Migrating to the new library wasn't straightforward because it is no
longer possible to treat WebSocket connections as a net.Conn.

* vendor: delete golang.org/x/net/websocket

* rpc: fix godoc comments and run gofmt

p2p/simulations/adapters/exec.go

@@ -41,7 +41,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/rpc"
-	"golang.org/x/net/websocket"
+	"github.com/gorilla/websocket"
 )
 
 func init() {
@@ -118,7 +118,7 @@ func (e *ExecAdapter) NewNode(config *NodeConfig) (Node, error) {
 	conf.Stack.P2P.NAT = nil
 	conf.Stack.NoUSB = true
 
-	// listen on a localhost port, which we set when we
+	// Listen on a localhost port, which we set when we
 	// initialise NodeConfig (usually a random port)
 	conf.Stack.P2P.ListenAddr = fmt.Sprintf(":%d", config.Port)
 
@@ -205,17 +205,17 @@ func (n *ExecNode) Start(snapshots map[string][]byte) (err error) {
 	}
 	n.Cmd = cmd
 
-	// read the WebSocket address from the stderr logs
+	// Wait for the node to start.
 	status := <-statusC
 	if status.Err != "" {
 		return errors.New(status.Err)
 	}
-	client, err := rpc.DialWebsocket(ctx, status.WSEndpoint, "http://localhost")
+	client, err := rpc.DialWebsocket(ctx, status.WSEndpoint, "")
 	if err != nil {
 		return fmt.Errorf("can't connect to RPC server: %v", err)
 	}
 
-	// node ready :)
+	// Node ready :)
 	n.client = client
 	n.wsAddr = status.WSEndpoint
 	n.Info = status.NodeInfo
@@ -314,31 +314,37 @@ func (n *ExecNode) NodeInfo() *p2p.NodeInfo {
 
 // ServeRPC serves RPC requests over the given connection by dialling the
 // node's WebSocket address and joining the two connections
-func (n *ExecNode) ServeRPC(clientConn net.Conn) error {
-	conn, err := websocket.Dial(n.wsAddr, "", "http://localhost")
+func (n *ExecNode) ServeRPC(clientConn *websocket.Conn) error {
+	conn, _, err := websocket.DefaultDialer.Dial(n.wsAddr, nil)
 	if err != nil {
 		return err
 	}
 	var wg sync.WaitGroup
 	wg.Add(2)
-	join := func(src, dst net.Conn) {
-		defer wg.Done()
-		io.Copy(dst, src)
-		// close the write end of the destination connection
-		if cw, ok := dst.(interface {
-			CloseWrite() error
-		}); ok {
-			cw.CloseWrite()
-		} else {
-			dst.Close()
-		}
-	}
-	go join(conn, clientConn)
-	go join(clientConn, conn)
+	go wsCopy(&wg, conn, clientConn)
+	go wsCopy(&wg, clientConn, conn)
 	wg.Wait()
+	conn.Close()
 	return nil
 }
 
+func wsCopy(wg *sync.WaitGroup, src, dst *websocket.Conn) {
+	defer wg.Done()
+	for {
+		msgType, r, err := src.NextReader()
+		if err != nil {
+			return
+		}
+		w, err := dst.NextWriter(msgType)
+		if err != nil {
+			return
+		}
+		if _, err = io.Copy(w, r); err != nil {
+			return
+		}
+	}
+}
+
 // Snapshots creates snapshots of the services by calling the
 // simulation_snapshot RPC method
 func (n *ExecNode) Snapshots() (map[string][]byte, error) {

p2p/simulations/adapters/inproc.go

@@ -30,6 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/simulations/pipes"
 	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/gorilla/websocket"
 )
 
 // SimAdapter is a NodeAdapter which creates in-memory simulation nodes and
@@ -210,13 +211,14 @@ func (sn *SimNode) Client() (*rpc.Client, error) {
 }
 
 // ServeRPC serves RPC requests over the given connection by creating an
-// in-memory client to the node's RPC server
-func (sn *SimNode) ServeRPC(conn net.Conn) error {
+// in-memory client to the node's RPC server.
+func (sn *SimNode) ServeRPC(conn *websocket.Conn) error {
 	handler, err := sn.node.RPCHandler()
 	if err != nil {
 		return err
 	}
-	handler.ServeCodec(rpc.NewJSONCodec(conn), rpc.OptionMethodInvocation|rpc.OptionSubscriptions)
+	codec := rpc.NewFuncCodec(conn, conn.WriteJSON, conn.ReadJSON)
+	handler.ServeCodec(codec, 0)
 	return nil
 }
 

p2p/simulations/adapters/types.go

@@ -33,6 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/gorilla/websocket"
 )
 
 // Node represents a node in a simulation network which is created by a
@@ -51,7 +52,7 @@ type Node interface {
 	Client() (*rpc.Client, error)
 
 	// ServeRPC serves RPC requests over the given connection
-	ServeRPC(net.Conn) error
+	ServeRPC(*websocket.Conn) error
 
 	// Start starts the node with the given snapshots
 	Start(snapshots map[string][]byte) error

p2p/simulations/http.go

@@ -34,8 +34,8 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
 	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/gorilla/websocket"
 	"github.com/julienschmidt/httprouter"
-	"golang.org/x/net/websocket"
 )
 
 // DefaultClient is the default simulation API client which expects the API
@@ -654,16 +654,20 @@ func (s *Server) Options(w http.ResponseWriter, req *http.Request) {
 	w.WriteHeader(http.StatusOK)
 }
 
+var wsUpgrade = websocket.Upgrader{
+	CheckOrigin: func(*http.Request) bool { return true },
+}
+
 // NodeRPC forwards RPC requests to a node in the network via a WebSocket
 // connection
 func (s *Server) NodeRPC(w http.ResponseWriter, req *http.Request) {
-	node := req.Context().Value("node").(*Node)
-
-	handler := func(conn *websocket.Conn) {
-		node.ServeRPC(conn)
+	conn, err := wsUpgrade.Upgrade(w, req, nil)
+	if err != nil {
+		return
 	}
-
-	websocket.Server{Handler: handler}.ServeHTTP(w, req)
+	defer conn.Close()
+	node := req.Context().Value("node").(*Node)
+	node.ServeRPC(conn)
 }
 
 // ServeHTTP implements the http.Handler interface by delegating to the

rpc/client.go

@@ -117,7 +117,7 @@ func (c *Client) newClientConn(conn ServerCodec) *clientConn {
 
 func (cc *clientConn) close(err error, inflightReq *requestOp) {
 	cc.handler.close(err, inflightReq)
-	cc.codec.Close()
+	cc.codec.close()
 }
 
 type readOp struct {
@@ -484,7 +484,7 @@ func (c *Client) write(ctx context.Context, msg interface{}) error {
 			return err
 		}
 	}
-	err := c.writeConn.Write(ctx, msg)
+	err := c.writeConn.writeJSON(ctx, msg)
 	if err != nil {
 		c.writeConn = nil
 	}
@@ -511,7 +511,7 @@ func (c *Client) reconnect(ctx context.Context) error {
 		c.writeConn = newconn
 		return nil
 	case <-c.didClose:
-		newconn.Close()
+		newconn.close()
 		return ErrClientQuit
 	}
 }
@@ -558,7 +558,7 @@ func (c *Client) dispatch(codec ServerCodec) {
 
 		// Reconnect:
 		case newcodec := <-c.reconnected:
-			log.Debug("RPC client reconnected", "reading", reading, "conn", newcodec.RemoteAddr())
+			log.Debug("RPC client reconnected", "reading", reading, "conn", newcodec.remoteAddr())
 			if reading {
 				// Wait for the previous read loop to exit. This is a rare case which
 				// happens if this loop isn't notified in time after the connection breaks.
@@ -612,9 +612,9 @@ func (c *Client) drainRead() {
 // read decodes RPC messages from a codec, feeding them into dispatch.
 func (c *Client) read(codec ServerCodec) {
 	for {
-		msgs, batch, err := codec.Read()
+		msgs, batch, err := codec.readBatch()
 		if _, ok := err.(*json.SyntaxError); ok {
-			codec.Write(context.Background(), errorMessage(&parseError{err.Error()}))
+			codec.writeJSON(context.Background(), errorMessage(&parseError{err.Error()}))
 		}
 		if err != nil {
 			c.readErr <- err

rpc/handler.go

@@ -85,8 +85,8 @@ func newHandler(connCtx context.Context, conn jsonWriter, idgen func() ID, reg *
 		serverSubs:     make(map[ID]*Subscription),
 		log:            log.Root(),
 	}
-	if conn.RemoteAddr() != "" {
-		h.log = h.log.New("conn", conn.RemoteAddr())
+	if conn.remoteAddr() != "" {
+		h.log = h.log.New("conn", conn.remoteAddr())
 	}
 	h.unsubscribeCb = newCallback(reflect.Value{}, reflect.ValueOf(h.unsubscribe))
 	return h
@@ -97,7 +97,7 @@ func (h *handler) handleBatch(msgs []*jsonrpcMessage) {
 	// Emit error response for empty batches:
 	if len(msgs) == 0 {
 		h.startCallProc(func(cp *callProc) {
-			h.conn.Write(cp.ctx, errorMessage(&invalidRequestError{"empty batch"}))
+			h.conn.writeJSON(cp.ctx, errorMessage(&invalidRequestError{"empty batch"}))
 		})
 		return
 	}
@@ -122,7 +122,7 @@ func (h *handler) handleBatch(msgs []*jsonrpcMessage) {
 		}
 		h.addSubscriptions(cp.notifiers)
 		if len(answers) > 0 {
-			h.conn.Write(cp.ctx, answers)
+			h.conn.writeJSON(cp.ctx, answers)
 		}
 		for _, n := range cp.notifiers {
 			n.activate()
@@ -139,7 +139,7 @@ func (h *handler) handleMsg(msg *jsonrpcMessage) {
 		answer := h.handleCallMsg(cp, msg)
 		h.addSubscriptions(cp.notifiers)
 		if answer != nil {
-			h.conn.Write(cp.ctx, answer)
+			h.conn.writeJSON(cp.ctx, answer)
 		}
 		for _, n := range cp.notifiers {
 			n.activate()

rpc/http.go

@@ -47,29 +47,29 @@ type httpConn struct {
 	client    *http.Client
 	req       *http.Request
 	closeOnce sync.Once
-	closed    chan interface{}
+	closeCh   chan interface{}
 }
 
 // httpConn is treated specially by Client.
-func (hc *httpConn) Write(context.Context, interface{}) error {
-	panic("Write called on httpConn")
+func (hc *httpConn) writeJSON(context.Context, interface{}) error {
+	panic("writeJSON called on httpConn")
 }
 
-func (hc *httpConn) RemoteAddr() string {
+func (hc *httpConn) remoteAddr() string {
 	return hc.req.URL.String()
 }
 
-func (hc *httpConn) Read() ([]*jsonrpcMessage, bool, error) {
-	<-hc.closed
+func (hc *httpConn) readBatch() ([]*jsonrpcMessage, bool, error) {
+	<-hc.closeCh
 	return nil, false, io.EOF
 }
 
-func (hc *httpConn) Close() {
-	hc.closeOnce.Do(func() { close(hc.closed) })
+func (hc *httpConn) close() {
+	hc.closeOnce.Do(func() { close(hc.closeCh) })
 }
 
-func (hc *httpConn) Closed() <-chan interface{} {
-	return hc.closed
+func (hc *httpConn) closed() <-chan interface{} {
+	return hc.closeCh
 }
 
 // HTTPTimeouts represents the configuration params for the HTTP RPC server.
@@ -116,7 +116,7 @@ func DialHTTPWithClient(endpoint string, client *http.Client) (*Client, error) {
 
 	initctx := context.Background()
 	return newClient(initctx, func(context.Context) (ServerCodec, error) {
-		return &httpConn{client: client, req: req, closed: make(chan interface{})}, nil
+		return &httpConn{client: client, req: req, closeCh: make(chan interface{})}, nil
 	})
 }
 
@@ -195,7 +195,7 @@ type httpServerConn struct {
 func newHTTPServerConn(r *http.Request, w http.ResponseWriter) ServerCodec {
 	body := io.LimitReader(r.Body, maxRequestContentLength)
 	conn := &httpServerConn{Reader: body, Writer: w, r: r}
-	return NewJSONCodec(conn)
+	return NewCodec(conn)
 }
 
 // Close does nothing and always returns nil.
@@ -266,7 +266,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	w.Header().Set("content-type", contentType)
 	codec := newHTTPServerConn(r, w)
-	defer codec.Close()
+	defer codec.close()
 	s.serveSingleRequest(ctx, codec)
 }
 

rpc/inproc.go

@@ -26,8 +26,8 @@ func DialInProc(handler *Server) *Client {
 	initctx := context.Background()
 	c, _ := newClient(initctx, func(context.Context) (ServerCodec, error) {
 		p1, p2 := net.Pipe()
-		go handler.ServeCodec(NewJSONCodec(p1), OptionMethodInvocation|OptionSubscriptions)
-		return NewJSONCodec(p2), nil
+		go handler.ServeCodec(NewCodec(p1), 0)
+		return NewCodec(p2), nil
 	})
 	return c
 }

rpc/ipc.go

@@ -35,7 +35,7 @@ func (s *Server) ServeListener(l net.Listener) error {
 			return err
 		}
 		log.Trace("Accepted RPC connection", "conn", conn.RemoteAddr())
-		go s.ServeCodec(NewJSONCodec(conn), OptionMethodInvocation|OptionSubscriptions)
+		go s.ServeCodec(NewCodec(conn), 0)
 	}
 }
 
@@ -51,6 +51,6 @@ func DialIPC(ctx context.Context, endpoint string) (*Client, error) {
 		if err != nil {
 			return nil, err
 		}
-		return NewJSONCodec(conn), err
+		return NewCodec(conn), err
 	})
 }