p2p: msg.Payload contains list data

With RLPx frames, the message code is contained in the
frame and is no longer part of the encoded data.

EncodeMsg, Msg.Decode have been updated to match.
Code that decodes RLP directly from Msg.Payload will need
to change.

p2p/message.go

@@ -51,19 +51,8 @@ type Msg struct {
 
 // NewMsg creates an RLP-encoded message with the given code.
 func NewMsg(code uint64, params ...interface{}) Msg {
-	buf := new(bytes.Buffer)
-	for _, p := range params {
-		buf.Write(ethutil.Encode(p))
-	}
-	return Msg{Code: code, Size: uint32(buf.Len()), Payload: buf}
-}
-
-func encodePayload(params ...interface{}) []byte {
-	buf := new(bytes.Buffer)
-	for _, p := range params {
-		buf.Write(ethutil.Encode(p))
-	}
-	return buf.Bytes()
+	p := bytes.NewReader(ethutil.Encode(params))
+	return Msg{Code: code, Size: uint32(p.Len()), Payload: p}
 }
 
 // Decode parse the RLP content of a message into
@@ -71,8 +60,7 @@ func encodePayload(params ...interface{}) []byte {
 //
 // For the decoding rules, please see package rlp.
 func (msg Msg) Decode(val interface{}) error {
-	s := rlp.NewListStream(msg.Payload, uint64(msg.Size))
-	if err := s.Decode(val); err != nil {
+	if err := rlp.Decode(msg.Payload, val); err != nil {
 		return newPeerError(errInvalidMsg, "(code %#x) (size %d) %v", msg.Code, msg.Size, err)
 	}
 	return nil

p2p/message_test.go

@@ -2,10 +2,12 @@ package p2p
 
 import (
 	"bytes"
+	"encoding/hex"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"runtime"
+	"strings"
 	"testing"
 	"time"
 )
@@ -15,11 +17,11 @@ func TestNewMsg(t *testing.T) {
 	if msg.Code != 3 {
 		t.Errorf("incorrect code %d, want %d", msg.Code)
 	}
-	if msg.Size != 5 {
-		t.Errorf("incorrect size %d, want %d", msg.Size, 5)
+	expect := unhex("c50183303030")
+	if msg.Size != uint32(len(expect)) {
+		t.Errorf("incorrect size %d, want %d", msg.Size, len(expect))
 	}
 	pl, _ := ioutil.ReadAll(msg.Payload)
-	expect := []byte{0x01, 0x83, 0x30, 0x30, 0x30}
 	if !bytes.Equal(pl, expect) {
 		t.Errorf("incorrect payload content, got %x, want %x", pl, expect)
 	}
@@ -139,3 +141,11 @@ func TestEOFSignal(t *testing.T) {
 	default:
 	}
 }
+
+func unhex(str string) []byte {
+	b, err := hex.DecodeString(strings.Replace(str, "\n", "", -1))
+	if err != nil {
+		panic(fmt.Sprintf("invalid hex string: %q", str))
+	}
+	return b
+}

p2p/peer.go

@@ -193,12 +193,12 @@ func (p *Peer) handle(msg Msg) error {
 		msg.Discard()
 		go EncodeMsg(p.rw, pongMsg)
 	case msg.Code == discMsg:
-		var reason DiscReason
+		var reason [1]DiscReason
 		// no need to discard or for error checking, we'll close the
 		// connection after this.
 		rlp.Decode(msg.Payload, &reason)
 		p.Disconnect(DiscRequested)
-		return discRequestedError(reason)
+		return discRequestedError(reason[0])
 	case msg.Code < baseProtocolLength:
 		// ignore other base protocol messages
 		return msg.Discard()

p2p/peer_test.go

@@ -85,41 +85,6 @@ func TestPeerProtoReadMsg(t *testing.T) {
 	}
 }
 
-func TestPeerProtoReadLargeMsg(t *testing.T) {
-	defer testlog(t).detach()
-
-	msgsize := uint32(10 * 1024 * 1024)
-	done := make(chan struct{})
-	proto := Protocol{
-		Name:   "a",
-		Length: 5,
-		Run: func(peer *Peer, rw MsgReadWriter) error {
-			msg, err := rw.ReadMsg()
-			if err != nil {
-				t.Errorf("read error: %v", err)
-			}
-			if msg.Size != msgsize+4 {
-				t.Errorf("incorrect msg.Size, got %d, expected %d", msg.Size, msgsize)
-			}
-			msg.Discard()
-			close(done)
-			return nil
-		},
-	}
-
-	closer, rw, _, errc := testPeer([]Protocol{proto})
-	defer closer.Close()
-
-	EncodeMsg(rw, 18, make([]byte, msgsize))
-	select {
-	case <-done:
-	case err := <-errc:
-		t.Errorf("peer returned: %v", err)
-	case <-time.After(2 * time.Second):
-		t.Errorf("receive timeout")
-	}
-}
-
 func TestPeerProtoEncodeMsg(t *testing.T) {
 	defer testlog(t).detach()
 
@@ -246,13 +211,9 @@ func expectMsg(r MsgReader, code uint64, content interface{}) error {
 		if err != nil {
 			panic("content encode error: " + err.Error())
 		}
-		// skip over list header in encoded value. this is temporary.
-		contentEncR := bytes.NewReader(contentEnc)
-		if k, _, err := rlp.NewStream(contentEncR).Kind(); k != rlp.List || err != nil {
-			panic("content must encode as RLP list")
+		if int(msg.Size) != len(contentEnc) {
+			return fmt.Errorf("message size mismatch: got %d, want %d", msg.Size, len(contentEnc))
 		}
-		contentEnc = contentEnc[len(contentEnc)-contentEncR.Len():]
-
 		actualContent, err := ioutil.ReadAll(msg.Payload)
 		if err != nil {
 			return err

p2p/rlpx_test.go

@@ -3,8 +3,6 @@ package p2p
 import (
 	"bytes"
 	"crypto/rand"
-	"encoding/hex"
-	"fmt"
 	"io/ioutil"
 	"strings"
 	"testing"
@@ -32,7 +30,7 @@ ba628a4ba590cb43f7848f41c4382885
 `)
 
 	// Check WriteMsg. This puts a message into the buffer.
-	if err := EncodeMsg(rw, 8, []interface{}{1, 2, 3, 4}); err != nil {
+	if err := EncodeMsg(rw, 8, 1, 2, 3, 4); err != nil {
 		t.Fatalf("WriteMsg error: %v", err)
 	}
 	written := buf.Bytes()
@@ -68,14 +66,6 @@ func (fakeHash) BlockSize() int              { return 0 }
 func (h fakeHash) Size() int           { return len(h) }
 func (h fakeHash) Sum(b []byte) []byte { return append(b, h...) }
 
-func unhex(str string) []byte {
-	b, err := hex.DecodeString(strings.Replace(str, "\n", "", -1))
-	if err != nil {
-		panic(fmt.Sprintf("invalid hex string: %q", str))
-	}
-	return b
-}
-
 func TestRlpxFrameRW(t *testing.T) {
 	var (
 		aesSecret      = make([]byte, 16)
@@ -112,7 +102,7 @@ func TestRlpxFrameRW(t *testing.T) {
 	for i := 0; i < 10; i++ {
 		// write message into conn buffer
 		wmsg := []interface{}{"foo", "bar", strings.Repeat("test", i)}
-		err := EncodeMsg(rw1, uint64(i), wmsg)
+		err := EncodeMsg(rw1, uint64(i), wmsg...)
 		if err != nil {
 			t.Fatalf("WriteMsg error (i=%d): %v", i, err)
 		}

p2p/server.go

@@ -10,6 +10,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/ethutil"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/p2p/nat"
@@ -135,7 +136,7 @@ func (srv *Server) SuggestPeer(n *discover.Node) {
 func (srv *Server) Broadcast(protocol string, code uint64, data ...interface{}) {
 	var payload []byte
 	if data != nil {
-		payload = encodePayload(data...)
+		payload = ethutil.Encode(data)
 	}
 	srv.lock.RLock()
 	defer srv.lock.RUnlock()

p2p/server_test.go

@@ -150,7 +150,7 @@ func TestServerBroadcast(t *testing.T) {
 
 	// broadcast one message
 	srv.Broadcast("discard", 0, "foo")
-	golden := unhex("66e94e166f0a2c3b884cfa59ca34")
+	golden := unhex("66e94d166f0a2c3b884cfa59ca34")
 
 	// check that the message has been written everywhere
 	for i, conn := range conns {