p2p: disable encryption handshake

The diff is a bit bigger than expected because the protocol handshake
logic has moved out of Peer. This is necessary because the protocol
handshake will have custom framing in the final protocol.

1 files changed, 59 insertions, 170 deletions

diff --git a/p2p/peer.go b/p2p/peer.go
index fd5bec7d5..b9bf0fd73 100644
--- a/p2p/peer.go
+++ b/p2p/peer.go
@@ -33,37 +33,14 @@ const (
 	peersMsg     = 0x05
 )
 
-// handshake is the RLP structure of the protocol handshake.
-type handshake struct {
-	Version    uint64
-	Name       string
-	Caps       []Cap
-	ListenPort uint64
-	NodeID     discover.NodeID
-}
-
 // Peer represents a connected remote node.
 type Peer struct {
 	// Peers have all the log methods.
 	// Use them to display messages related to the peer.
 	*logger.Logger
 
-	infoMu sync.Mutex
-	name   string
-	caps   []Cap
-
-	ourID, remoteID *discover.NodeID
-	ourName         string
-
-	rw *frameRW
-
-	// These fields maintain the running protocols.
-	protocols []Protocol
-	runlock   sync.RWMutex // protects running
-	running   map[string]*proto
-
-	// disables protocol handshake, for testing
-	noHandshake bool
+	rw      *conn
+	running map[string]*protoRW
 
 	protoWG  sync.WaitGroup
 	protoErr chan error
@@ -73,36 +50,27 @@ type Peer struct {
 
 // NewPeer returns a peer for testing purposes.
 func NewPeer(id discover.NodeID, name string, caps []Cap) *Peer {
-	conn, _ := net.Pipe()
-	peer := newPeer(conn, nil, "", nil, &id)
-	peer.setHandshakeInfo(name, caps)
+	pipe, _ := net.Pipe()
+	conn := newConn(pipe, &protoHandshake{ID: id, Name: name, Caps: caps})
+	peer := newPeer(conn, nil)
 	close(peer.closed) // ensures Disconnect doesn't block
 	return peer
 }
 
 // ID returns the node's public key.
 func (p *Peer) ID() discover.NodeID {
-	return *p.remoteID
+	return p.rw.ID
 }
 
 // Name returns the node name that the remote node advertised.
 func (p *Peer) Name() string {
-	// this needs a lock because the information is part of the
-	// protocol handshake.
-	p.infoMu.Lock()
-	name := p.name
-	p.infoMu.Unlock()
-	return name
+	return p.rw.Name
 }
 
 // Caps returns the capabilities (supported subprotocols) of the remote peer.
 func (p *Peer) Caps() []Cap {
-	// this needs a lock because the information is part of the
-	// protocol handshake.
-	p.infoMu.Lock()
-	caps := p.caps
-	p.infoMu.Unlock()
-	return caps
+	// TODO: maybe return copy
+	return p.rw.Caps
 }
 
 // RemoteAddr returns the remote address of the network connection.
@@ -126,30 +94,20 @@ func (p *Peer) Disconnect(reason DiscReason) {
 
 // String implements fmt.Stringer.
 func (p *Peer) String() string {
-	return fmt.Sprintf("Peer %.8x %v", p.remoteID[:], p.RemoteAddr())
+	return fmt.Sprintf("Peer %.8x %v", p.rw.ID[:], p.RemoteAddr())
 }
 
-func newPeer(conn net.Conn, protocols []Protocol, ourName string, ourID, remoteID *discover.NodeID) *Peer {
-	logtag := fmt.Sprintf("Peer %.8x %v", remoteID[:], conn.RemoteAddr())
-	return &Peer{
-		Logger:    logger.NewLogger(logtag),
-		rw:        newFrameRW(conn, msgWriteTimeout),
-		ourID:     ourID,
-		ourName:   ourName,
-		remoteID:  remoteID,
-		protocols: protocols,
-		running:   make(map[string]*proto),
-		disc:      make(chan DiscReason),
-		protoErr:  make(chan error),
-		closed:    make(chan struct{}),
+func newPeer(conn *conn, protocols []Protocol) *Peer {
+	logtag := fmt.Sprintf("Peer %.8x %v", conn.ID[:], conn.RemoteAddr())
+	p := &Peer{
+		Logger:   logger.NewLogger(logtag),
+		rw:       conn,
+		running:  matchProtocols(protocols, conn.Caps, conn),
+		disc:     make(chan DiscReason),
+		protoErr: make(chan error),
+		closed:   make(chan struct{}),
 	}
-}
-
-func (p *Peer) setHandshakeInfo(name string, caps []Cap) {
-	p.infoMu.Lock()
-	p.name = name
-	p.caps = caps
-	p.infoMu.Unlock()
+	return p
 }
 
 func (p *Peer) run() DiscReason {
@@ -157,16 +115,9 @@ func (p *Peer) run() DiscReason {
 	defer p.closeProtocols()
 	defer close(p.closed)
 
+	p.startProtocols()
 	go func() { readErr <- p.readLoop() }()
 
-	if !p.noHandshake {
-		if err := writeProtocolHandshake(p.rw, p.ourName, *p.ourID, p.protocols); err != nil {
-			p.DebugDetailf("Protocol handshake error: %v\n", err)
-			p.rw.Close()
-			return DiscProtocolError
-		}
-	}
-
 	// Wait for an error or disconnect.
 	var reason DiscReason
 	select {
@@ -206,11 +157,6 @@ func (p *Peer) politeDisconnect(reason DiscReason) {
 }
 
 func (p *Peer) readLoop() error {
-	if !p.noHandshake {
-		if err := readProtocolHandshake(p, p.rw); err != nil {
-			return err
-		}
-	}
 	for {
 		msg, err := p.rw.ReadMsg()
 		if err != nil {
@@ -249,105 +195,51 @@ func (p *Peer) handle(msg Msg) error {
 	return nil
 }
 
-func readProtocolHandshake(p *Peer, rw MsgReadWriter) error {
-	// read and handle remote handshake
-	msg, err := rw.ReadMsg()
-	if err != nil {
-		return err
-	}
-	if msg.Code == discMsg {
-		// disconnect before protocol handshake is valid according to the
-		// spec and we send it ourself if Server.addPeer fails.
-		var reason DiscReason
-		rlp.Decode(msg.Payload, &reason)
-		return discRequestedError(reason)
-	}
-	if msg.Code != handshakeMsg {
-		return newPeerError(errProtocolBreach, "expected handshake, got %x", msg.Code)
-	}
-	if msg.Size > baseProtocolMaxMsgSize {
-		return newPeerError(errInvalidMsg, "message too big")
-	}
-	var hs handshake
-	if err := msg.Decode(&hs); err != nil {
-		return err
-	}
-	// validate handshake info
-	if hs.Version != baseProtocolVersion {
-		return newPeerError(errP2PVersionMismatch, "required version %d, received %d\n",
-			baseProtocolVersion, hs.Version)
-	}
-	if hs.NodeID == *p.remoteID {
-		return newPeerError(errPubkeyForbidden, "node ID mismatch")
-	}
-	// TODO: remove Caps with empty name
-	p.setHandshakeInfo(hs.Name, hs.Caps)
-	p.startSubprotocols(hs.Caps)
-	return nil
-}
-
-func writeProtocolHandshake(w MsgWriter, name string, id discover.NodeID, ps []Protocol) error {
-	var caps []interface{}
-	for _, proto := range ps {
-		caps = append(caps, proto.cap())
-	}
-	return EncodeMsg(w, handshakeMsg, baseProtocolVersion, name, caps, 0, id)
-}
-
-// startProtocols starts matching named subprotocols.
-func (p *Peer) startSubprotocols(caps []Cap) {
+// matchProtocols creates structures for matching named subprotocols.
+func matchProtocols(protocols []Protocol, caps []Cap, rw MsgReadWriter) map[string]*protoRW {
 	sort.Sort(capsByName(caps))
-	p.runlock.Lock()
-	defer p.runlock.Unlock()
 	offset := baseProtocolLength
+	result := make(map[string]*protoRW)
 outer:
 	for _, cap := range caps {
-		for _, proto := range p.protocols {
-			if proto.Name == cap.Name &&
-				proto.Version == cap.Version &&
-				p.running[cap.Name] == nil {
-				p.running[cap.Name] = p.startProto(offset, proto)
+		for _, proto := range protocols {
+			if proto.Name == cap.Name && proto.Version == cap.Version && result[cap.Name] == nil {
+				result[cap.Name] = &protoRW{Protocol: proto, offset: offset, in: make(chan Msg), w: rw}
 				offset += proto.Length
 				continue outer
 			}
 		}
 	}
+	return result
 }
 
-func (p *Peer) startProto(offset uint64, impl Protocol) *proto {
-	p.DebugDetailf("Starting protocol %s/%d\n", impl.Name, impl.Version)
-	rw := &proto{
-		name:    impl.Name,
-		in:      make(chan Msg),
-		offset:  offset,
-		maxcode: impl.Length,
-		w:       p.rw,
+func (p *Peer) startProtocols() {
+	for _, proto := range p.running {
+		proto := proto
+		p.DebugDetailf("Starting protocol %s/%d\n", proto.Name, proto.Version)
+		p.protoWG.Add(1)
+		go func() {
+			err := proto.Run(p, proto)
+			if err == nil {
+				p.DebugDetailf("Protocol %s/%d returned\n", proto.Name, proto.Version)
+				err = errors.New("protocol returned")
+			} else {
+				p.DebugDetailf("Protocol %s/%d error: %v\n", proto.Name, proto.Version, err)
+			}
+			select {
+			case p.protoErr <- err:
+			case <-p.closed:
+			}
+			p.protoWG.Done()
+		}()
 	}
-	p.protoWG.Add(1)
-	go func() {
-		err := impl.Run(p, rw)
-		if err == nil {
-			p.DebugDetailf("Protocol %s/%d returned\n", impl.Name, impl.Version)
-			err = errors.New("protocol returned")
-		} else {
-			p.DebugDetailf("Protocol %s/%d error: %v\n", impl.Name, impl.Version, err)
-		}
-		select {
-		case p.protoErr <- err:
-		case <-p.closed:
-		}
-		p.protoWG.Done()
-	}()
-	return rw
 }
 
 // getProto finds the protocol responsible for handling
 // the given message code.
-func (p *Peer) getProto(code uint64) (*proto, error) {
-	p.runlock.RLock()
-	defer p.runlock.RUnlock()
+func (p *Peer) getProto(code uint64) (*protoRW, error) {
 	for _, proto := range p.running {
-		if code >= proto.offset && code < proto.offset+proto.maxcode {
+		if code >= proto.offset && code < proto.offset+proto.Length {
 			return proto, nil
 		}
 	}
@@ -355,46 +247,43 @@ func (p *Peer) getProto(code uint64) (*proto, error) {
 }
 
 func (p *Peer) closeProtocols() {
-	p.runlock.RLock()
 	for _, p := range p.running {
 		close(p.in)
 	}
-	p.runlock.RUnlock()
 	p.protoWG.Wait()
 }
 
 // writeProtoMsg sends the given message on behalf of the given named protocol.
 // this exists because of Server.Broadcast.
 func (p *Peer) writeProtoMsg(protoName string, msg Msg) error {
-	p.runlock.RLock()
 	proto, ok := p.running[protoName]
-	p.runlock.RUnlock()
 	if !ok {
 		return fmt.Errorf("protocol %s not handled by peer", protoName)
 	}
-	if msg.Code >= proto.maxcode {
+	if msg.Code >= proto.Length {
 		return newPeerError(errInvalidMsgCode, "code %x is out of range for protocol %q", msg.Code, protoName)
 	}
 	msg.Code += proto.offset
 	return p.rw.WriteMsg(msg)
 }
 
-type proto struct {
-	name            string
-	in              chan Msg
-	maxcode, offset uint64
-	w               MsgWriter
+type protoRW struct {
+	Protocol
+
+	in     chan Msg
+	offset uint64
+	w      MsgWriter
 }
 
-func (rw *proto) WriteMsg(msg Msg) error {
-	if msg.Code >= rw.maxcode {
+func (rw *protoRW) WriteMsg(msg Msg) error {
+	if msg.Code >= rw.Length {
 		return newPeerError(errInvalidMsgCode, "not handled")
 	}
 	msg.Code += rw.offset
 	return rw.w.WriteMsg(msg)
 }
 
-func (rw *proto) ReadMsg() (Msg, error) {
+func (rw *protoRW) ReadMsg() (Msg, error) {
 	msg, ok := <-rw.in
 	if !ok {
 		return msg, io.EOF