p2p/simulations: Use WebSocket RPC

Signed-off-by: Lewis Marshall <lewis@lmars.net>

node/api.go

@@ -203,7 +203,7 @@ func (api *PrivateAdminAPI) StartWS(host *string, port *int, allowedOrigins *str
 		}
 	}
 
-	if err := api.node.startWS(fmt.Sprintf("%s:%d", *host, *port), api.node.rpcAPIs, modules, origins); err != nil {
+	if err := api.node.startWS(fmt.Sprintf("%s:%d", *host, *port), api.node.rpcAPIs, modules, origins, api.node.config.WSExposeAll); err != nil {
 		return false, err
 	}
 	return true, nil

node/config.go

@@ -128,6 +128,13 @@ type Config struct {
 	// If the module list is empty, all RPC API endpoints designated public will be
 	// exposed.
 	WSModules []string `toml:",omitempty"`
+
+	// WSExposeAll exposes all API modules via the WebSocket RPC interface rather
+	// than just the public ones.
+	//
+	// *WARNING* Only set this if the node is running in a trusted network, exposing
+	// private APIs to untrusted users is a major security risk.
+	WSExposeAll bool `toml:",omitempty"`
 }
 
 // IPCEndpoint resolves an IPC endpoint based on a configured value, taking into

node/node.go

@@ -275,7 +275,7 @@ func (n *Node) startRPC(services map[reflect.Type]Service) error {
 		n.stopInProc()
 		return err
 	}
-	if err := n.startWS(n.wsEndpoint, apis, n.config.WSModules, n.config.WSOrigins); err != nil {
+	if err := n.startWS(n.wsEndpoint, apis, n.config.WSModules, n.config.WSOrigins, n.config.WSExposeAll); err != nil {
 		n.stopHTTP()
 		n.stopIPC()
 		n.stopInProc()
@@ -426,7 +426,7 @@ func (n *Node) stopHTTP() {
 }
 
 // startWS initializes and starts the websocket RPC endpoint.
-func (n *Node) startWS(endpoint string, apis []rpc.API, modules []string, wsOrigins []string) error {
+func (n *Node) startWS(endpoint string, apis []rpc.API, modules []string, wsOrigins []string, exposeAll bool) error {
 	// Short circuit if the WS endpoint isn't being exposed
 	if endpoint == "" {
 		return nil
@@ -439,7 +439,7 @@ func (n *Node) startWS(endpoint string, apis []rpc.API, modules []string, wsOrig
 	// Register all the APIs exposed by the services
 	handler := rpc.NewServer()
 	for _, api := range apis {
-		if whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
+		if exposeAll || whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
 			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
 				return err
 			}
@@ -455,7 +455,7 @@ func (n *Node) startWS(endpoint string, apis []rpc.API, modules []string, wsOrig
 		return err
 	}
 	go rpc.NewWSServer(wsOrigins, handler).Serve(listener)
-	log.Info(fmt.Sprintf("WebSocket endpoint opened: ws://%s", endpoint))
+	log.Info(fmt.Sprintf("WebSocket endpoint opened: ws://%s", listener.Addr()))
 
 	// All listeners booted successfully
 	n.wsEndpoint = endpoint

p2p/simulations/adapters/exec.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"bufio"
 	"context"
 	"crypto/ecdsa"
 	"encoding/json"
@@ -12,7 +13,9 @@ import (
 	"os/exec"
 	"os/signal"
 	"path/filepath"
+	"regexp"
 	"strings"
+	"sync"
 	"syscall"
 	"time"
 
@@ -22,6 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/rpc"
+	"golang.org/x/net/websocket"
 )
 
 // ExecAdapter is a NodeAdapter which runs nodes by executing the current
@@ -69,6 +73,10 @@ func (e *ExecAdapter) NewNode(config *NodeConfig) (Node, error) {
 		Node:  config,
 	}
 	conf.Stack.DataDir = filepath.Join(dir, "data")
+	conf.Stack.WSHost = "127.0.0.1"
+	conf.Stack.WSPort = 0
+	conf.Stack.WSOrigins = []string{"*"}
+	conf.Stack.WSExposeAll = true
 	conf.Stack.P2P.EnableMsgEvents = false
 	conf.Stack.P2P.NoDiscovery = true
 	conf.Stack.P2P.NAT = nil
@@ -101,7 +109,7 @@ type ExecNode struct {
 	Info   *p2p.NodeInfo
 
 	client *rpc.Client
-	rpcMux *rpcMux
+	wsAddr string
 	newCmd func() *exec.Cmd
 	key    *ecdsa.PrivateKey
 }
@@ -120,6 +128,10 @@ func (n *ExecNode) Client() (*rpc.Client, error) {
 	return n.client, nil
 }
 
+// wsAddrPattern is a regex used to read the WebSocket address from the node's
+// log
+var wsAddrPattern = regexp.MustCompile(`ws://[\d.:]+`)
+
 // Start exec's the node passing the ID and service as command line arguments
 // and the node config encoded as JSON in the _P2P_NODE_CONFIG environment
 // variable
@@ -142,29 +154,61 @@ func (n *ExecNode) Start(snapshots map[string][]byte) (err error) {
 		return fmt.Errorf("error generating node config: %s", err)
 	}
 
-	// create a net.Pipe for RPC communication over stdin / stdout
+	// use a pipe for stderr so we can both copy the node's stderr to
-	pipe1, pipe2 := net.Pipe()
+	// os.Stderr and read the WebSocket address from the logs
+	stderrR, stderrW := io.Pipe()
+	stderr := io.MultiWriter(os.Stderr, stderrW)
 
 	// start the node
 	cmd := n.newCmd()
-	cmd.Stdin = pipe1
+	cmd.Stdout = os.Stdout
-	cmd.Stdout = pipe1
+	cmd.Stderr = stderr
-	cmd.Stderr = os.Stderr
 	cmd.Env = append(os.Environ(), fmt.Sprintf("_P2P_NODE_CONFIG=%s", confData))
 	if err := cmd.Start(); err != nil {
 		return fmt.Errorf("error starting node: %s", err)
 	}
 	n.Cmd = cmd
 
+	// read the WebSocket address from the stderr logs
+	var wsAddr string
+	errC := make(chan error)
+	go func() {
+		s := bufio.NewScanner(stderrR)
+		for s.Scan() {
+			if strings.Contains(s.Text(), "WebSocket endpoint opened:") {
+				wsAddr = wsAddrPattern.FindString(s.Text())
+				break
+			}
+		}
+		select {
+		case errC <- s.Err():
+		default:
+		}
+	}()
+	select {
+	case err := <-errC:
+		if err != nil {
+			return fmt.Errorf("error reading WebSocket address from stderr: %s", err)
+		} else if wsAddr == "" {
+			return errors.New("failed to read WebSocket address from stderr")
+		}
+	case <-time.After(10 * time.Second):
+		return errors.New("timed out waiting for WebSocket address on stderr")
+	}
+
 	// create the RPC client and load the node info
-	n.rpcMux = newRPCMux(pipe2)
-	n.client = n.rpcMux.Client()
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
+	client, err := rpc.DialWebsocket(ctx, wsAddr, "")
+	if err != nil {
+		return fmt.Errorf("error dialing rpc websocket: %s", err)
+	}
 	var info p2p.NodeInfo
-	if err := n.client.CallContext(ctx, &info, "admin_nodeInfo"); err != nil {
+	if err := client.CallContext(ctx, &info, "admin_nodeInfo"); err != nil {
 		return fmt.Errorf("error getting node info: %s", err)
 	}
+	n.client = client
+	n.wsAddr = wsAddr
 	n.Info = &info
 
 	return nil
@@ -193,6 +237,7 @@ func (n *ExecNode) Stop() error {
 	if n.client != nil {
 		n.client.Close()
 		n.client = nil
+		n.wsAddr = ""
 		n.Info = nil
 	}
 
@@ -222,13 +267,30 @@ func (n *ExecNode) NodeInfo() *p2p.NodeInfo {
 	return info
 }
 
-// ServeRPC serves RPC requests over the given connection using the node's
+// ServeRPC serves RPC requests over the given connection by dialling the
-// RPC multiplexer
+// node's WebSocket address and joining the two connections
-func (n *ExecNode) ServeRPC(conn net.Conn) error {
+func (n *ExecNode) ServeRPC(clientConn net.Conn) error {
-	if n.rpcMux == nil {
+	conn, err := websocket.Dial(n.wsAddr, "", "http://localhost")
-		return errors.New("RPC not started")
+	if err != nil {
+		return err
 	}
-	n.rpcMux.Serve(conn)
+	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)
+	wg.Wait()
 	return nil
 }
 
@@ -313,15 +375,6 @@ func execP2PNode() {
 		log.Crit("error starting p2p node", "err", err)
 	}
 
-	// use stdin / stdout for RPC to avoid the parent needing to access
-	// either the local filesystem or TCP stack (useful when running in
-	// Docker)
-	handler, err := stack.RPCHandler()
-	if err != nil {
-		log.Crit("error getting RPC server", "err", err)
-	}
-	go handler.ServeCodec(rpc.NewJSONCodec(&stdioConn{os.Stdin, os.Stdout}), rpc.OptionMethodInvocation|rpc.OptionSubscriptions)
-
 	go func() {
 		sigc := make(chan os.Signal, 1)
 		signal.Notify(sigc, syscall.SIGTERM)
@@ -404,14 +457,3 @@ func (api SnapshotAPI) Snapshot() (map[string][]byte, error) {
 	}
 	return snapshots, nil
 }
-
-// stdioConn wraps os.Stdin / os.Stdout with a no-op Close method so we can
-// use stdio for RPC messages
-type stdioConn struct {
-	io.Reader
-	io.Writer
-}
-
-func (r *stdioConn) Close() error {
-	return nil
-}

p2p/simulations/adapters/inproc.go

@@ -119,7 +119,6 @@ type SimNode struct {
 	node    *node.Node
 	running []node.Service
 	client  *rpc.Client
-	rpcMux  *rpcMux
 }
 
 // Addr returns the node's discovery address
@@ -135,24 +134,28 @@ func (self *SimNode) Node() *discover.Node {
 // Client returns an rpc.Client which can be used to communicate with the
 // underlying service (it is set once the node has started)
 func (self *SimNode) Client() (*rpc.Client, error) {
-	self.lock.Lock()
+	self.lock.RLock()
-	defer self.lock.Unlock()
+	defer self.lock.RUnlock()
 	if self.client == nil {
-		return nil, errors.New("RPC not started")
+		return nil, errors.New("node not started")
 	}
 	return self.client, nil
 }
 
-// ServeRPC serves RPC requests over the given connection using the node's
+// ServeRPC serves RPC requests over the given connection by creating an
-// RPC multiplexer
+// in-process client to the node's RPC server
 func (self *SimNode) ServeRPC(conn net.Conn) error {
-	self.lock.Lock()
+	self.lock.RLock()
-	mux := self.rpcMux
+	node := self.node
-	self.lock.Unlock()
+	self.lock.RUnlock()
-	if mux == nil {
+	if node == nil {
-		return errors.New("RPC not started")
+		return errors.New("node not started")
 	}
-	mux.Serve(conn)
+	handler, err := node.RPCHandler()
+	if err != nil {
+		return err
+	}
+	handler.ServeCodec(rpc.NewJSONCodec(conn), rpc.OptionMethodInvocation|rpc.OptionSubscriptions)
 	return nil
 }
 
@@ -213,18 +216,12 @@ func (self *SimNode) Start(snapshots map[string][]byte) error {
 		return err
 	}
 
+	// create an in-process RPC client
 	handler, err := node.RPCHandler()
 	if err != nil {
 		return err
 	}
-
+	self.client = rpc.DialInProc(handler)
-	// create an in-process RPC multiplexer
-	pipe1, pipe2 := net.Pipe()
-	go handler.ServeCodec(rpc.NewJSONCodec(pipe1), rpc.OptionMethodInvocation|rpc.OptionSubscriptions)
-	self.rpcMux = newRPCMux(pipe2)
-
-	// create an in-process RPC client
-	self.client = self.rpcMux.Client()
 
 	self.node = node
 

p2p/simulations/adapters/rpc_mux.go

@@ -1,218 +0,0 @@
-// Copyright 2016 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package adapters
-
-import (
-	"encoding/json"
-	"net"
-	"strconv"
-	"strings"
-	"sync"
-
-	"github.com/ethereum/go-ethereum/rpc"
-)
-
-// rpcMux is an RPC multiplexer which allows many clients to make RPC requests
-// over a single connection by changing each request's ID to a unique value.
-//
-// This is used by node adapters so that simulations can create many RPC
-// clients all sending requests over the underlying node's stdin / stdout.
-type rpcMux struct {
-	conn net.Conn
-
-	mtx       sync.Mutex
-	idCounter uint64
-	msgMap    map[uint64]*rpcMsg
-	subMap    map[string]*rpcReply
-	send      chan *rpcMsg
-}
-
-type rpcMsg struct {
-	Method  string          `json:"method,omitempty"`
-	Version string          `json:"jsonrpc,omitempty"`
-	ID      json.RawMessage `json:"id,omitempty"`
-	Payload json.RawMessage `json:"params,omitempty"`
-	Result  json.RawMessage `json:"result,omitempty"`
-	Error   json.RawMessage `json:"error,omitempty"`
-
-	id    uint64
-	reply *rpcReply
-}
-
-// rpcSub is the payload or result of a subscription RPC message
-type rpcSub struct {
-	Subscription string          `json:"subscription"`
-	Result       json.RawMessage `json:"result,omitempty"`
-}
-
-// rpcReply receives replies to RPC messages for a particular client
-type rpcReply struct {
-	ch        chan *rpcMsg
-	closeOnce sync.Once
-}
-
-func (r *rpcReply) close() {
-	r.closeOnce.Do(func() { close(r.ch) })
-}
-
-func newRPCMux(conn net.Conn) *rpcMux {
-	mux := &rpcMux{
-		msgMap: make(map[uint64]*rpcMsg),
-		subMap: make(map[string]*rpcReply),
-		send:   make(chan *rpcMsg),
-	}
-	go mux.sendLoop(conn)
-	go mux.recvLoop(conn)
-	return mux
-}
-
-// Client creates a new RPC client which sends messages through the multiplexer
-func (mux *rpcMux) Client() *rpc.Client {
-	pipe1, pipe2 := net.Pipe()
-	go mux.Serve(pipe1)
-	return rpc.NewClientWithConn(pipe2)
-}
-
-// Serve reads RPC messages from the given connection, forwards them to the
-// multiplexed connnection and writes replies back to the given connection
-func (mux *rpcMux) Serve(conn net.Conn) {
-	// reply will receive replies to any messages we send
-	reply := &rpcReply{ch: make(chan *rpcMsg)}
-	defer func() {
-		// drain the channel to prevent blocking the recvLoop
-		for range reply.ch {
-		}
-	}()
-
-	// start a goroutine to read RPC messages from the connection and
-	// forward them to the sendLoop
-	done := make(chan struct{})
-	go func() {
-		defer close(done)
-		dec := json.NewDecoder(conn)
-		for {
-			msg := &rpcMsg{}
-			if err := dec.Decode(msg); err != nil {
-				return
-			}
-			msg.reply = reply
-			mux.send <- msg
-		}
-	}()
-
-	// write message replies to the connection
-	enc := json.NewEncoder(conn)
-	for {
-		select {
-		case msg, ok := <-reply.ch:
-			if !ok {
-				return
-			}
-			if err := enc.Encode(msg); err != nil {
-				return
-			}
-		case <-done:
-			return
-		}
-	}
-}
-
-// sendLoop receives messages from the send channel, changes their ID and
-// writes them to the given connection
-func (mux *rpcMux) sendLoop(conn net.Conn) {
-	enc := json.NewEncoder(conn)
-	for msg := range mux.send {
-		if err := enc.Encode(mux.newMsg(msg)); err != nil {
-			return
-		}
-	}
-}
-
-// recvLoop reads messages from the given connection, changes their ID back
-// to the oringal value and sends them to the message's reply channel
-func (mux *rpcMux) recvLoop(conn net.Conn) {
-	// close all reply channels if we get an error
-	defer func() {
-		mux.mtx.Lock()
-		defer mux.mtx.Unlock()
-		for _, msg := range mux.msgMap {
-			msg.reply.close()
-		}
-	}()
-
-	dec := json.NewDecoder(conn)
-	for {
-		msg := &rpcMsg{}
-		if err := dec.Decode(msg); err != nil {
-			return
-		}
-		if reply := mux.lookup(msg); reply != nil {
-			reply.ch <- msg
-		}
-	}
-}
-
-// newMsg copies the given message and changes it's ID to a unique value
-func (mux *rpcMux) newMsg(msg *rpcMsg) *rpcMsg {
-	mux.mtx.Lock()
-	defer mux.mtx.Unlock()
-	id := mux.idCounter
-	mux.idCounter++
-	mux.msgMap[id] = msg
-	newMsg := *msg
-	newMsg.ID = json.RawMessage(strconv.FormatUint(id, 10))
-	return &newMsg
-}
-
-// lookup looks up the original message for which the given message is a reply
-func (mux *rpcMux) lookup(msg *rpcMsg) *rpcReply {
-	mux.mtx.Lock()
-	defer mux.mtx.Unlock()
-
-	// if the message has no ID, it is a subscription notification so
-	// lookup the original subscribe message
-	if msg.ID == nil {
-		sub := &rpcSub{}
-		if err := json.Unmarshal(msg.Payload, sub); err != nil {
-			return nil
-		}
-		return mux.subMap[sub.Subscription]
-	}
-
-	// lookup the original message and restore the ID
-	id, err := strconv.ParseUint(string(msg.ID), 10, 64)
-	if err != nil {
-		return nil
-	}
-	origMsg, ok := mux.msgMap[id]
-	if !ok {
-		return nil
-	}
-	delete(mux.msgMap, id)
-	msg.ID = origMsg.ID
-
-	// if the original message was a subscription, store the subscription
-	// ID so we can detect notifications
-	if strings.HasSuffix(string(origMsg.Method), "_subscribe") {
-		var result string
-		if err := json.Unmarshal(msg.Result, &result); err == nil {
-			mux.subMap[result] = origMsg.reply
-		}
-	}
-
-	return origMsg.reply
-}