eth protocol changes

- changed backend interface
- using callbacks for blockPool
- use rlp stream for lazy decoding
- use peer as logger
- add id (peer pubkey) to ethProtocol fields
- add testPeer to protocol test (temporary)

eth/protocol.go

@@ -7,18 +7,16 @@ import (
 
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethutil"
-	ethlogger "github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
 )
 
-var logger = ethlogger.NewLogger("SERV")
-
 // ethProtocol represents the ethereum wire protocol
 // instance is running on each peer
 type ethProtocol struct {
 	eth  backend
-	td   *big.Int
 	peer *p2p.Peer
+	id   string
 	rw   p2p.MsgReadWriter
 }
 
@@ -26,28 +24,21 @@ type ethProtocol struct {
 // used as an argument to EthProtocol
 type backend interface {
 	GetTransactions() (txs []*types.Transaction)
-	AddTransactions(txs []*types.Transaction)
+	AddTransactions([]*types.Transaction)
 	GetBlockHashes(hash []byte, amount uint32) (hashes [][]byte)
-	AddHash(hash []byte, peer *p2p.Peer) (more bool)
+	AddBlockHashes(next func() ([]byte, bool), peerId string)
 	GetBlock(hash []byte) (block *types.Block)
-	AddBlock(td *big.Int, block *types.Block, peer *p2p.Peer) (fetchHashes bool, err error)
+	AddBlock(block *types.Block, peerId string) (err error)
-	AddPeer(td *big.Int, currentBlock []byte, peer *p2p.Peer) (fetchHashes bool)
+	AddPeer(td *big.Int, currentBlock []byte, peerId string, requestHashes func([]byte) error, requestBlocks func([][]byte) error, invalidBlock func(error)) (best bool)
+	RemovePeer(peerId string)
 	Status() (td *big.Int, currentBlock []byte, genesisBlock []byte)
 }
 
 const (
 	ProtocolVersion    = 43
-	// 0x00 // PoC-1
-	// 0x01 // PoC-2
-	// 0x07 // PoC-3
-	// 0x09 // PoC-4
-	// 0x17 // PoC-5
-	// 0x1c // PoC-6
 	NetworkId          = 0
 	ProtocolLength     = uint64(8)
 	ProtocolMaxMsgSize = 10 * 1024 * 1024
-
-	blockHashesBatchSize = 256
 )
 
 // eth protocol message codes
@@ -74,7 +65,8 @@ type getBlockHashesMsgData struct {
 }
 
 // main entrypoint, wrappers starting a server running the eth protocol
-// use this constructor to attach the protocol (class) to server caps
+// use this constructor to attach the protocol ("class") to server caps
+// the Dev p2p layer then runs the protocol instance on each peer
 func EthProtocol(eth backend) *p2p.Protocol {
 	return &p2p.Protocol{
 		Name:    "eth",
@@ -86,11 +78,14 @@ func EthProtocol(eth backend) *p2p.Protocol {
 	}
 }
 
+// the main loop that handles incoming messages
+// note RemovePeer in the post-disconnect hook
 func runEthProtocol(eth backend, peer *p2p.Peer, rw p2p.MsgReadWriter) (err error) {
 	self := &ethProtocol{
 		eth:  eth,
 		rw:   rw,
 		peer: peer,
+		id:   (string)(peer.Identity().Pubkey()),
 	}
 	err = self.handleStatus()
 	if err == nil {
@@ -98,6 +93,7 @@ func runEthProtocol(eth backend, peer *p2p.Peer, rw p2p.MsgReadWriter) (err erro
 			for {
 				err = self.handle()
 				if err != nil {
+					self.eth.RemovePeer(self.id)
 					break
 				}
 			}
@@ -132,6 +128,7 @@ func (self *ethProtocol) handle() error {
 		return self.rw.EncodeMsg(TxMsg, txsInterface...)
 
 	case TxMsg:
+		// TODO: rework using lazy RLP stream
 		var txs []*types.Transaction
 		if err := msg.Decode(&txs); err != nil {
 			return ProtocolError(ErrDecode, "%v", err)
@@ -148,29 +145,26 @@ func (self *ethProtocol) handle() error {
 
 	case BlockHashesMsg:
 		// TODO: redo using lazy decode , this way very inefficient on known chains
-		// s := rlp.NewListStream(msg.Payload, uint64(msg.Size))
+		msgStream := rlp.NewListStream(msg.Payload, uint64(msg.Size))
-		var blockHashes [][]byte
+		var err error
-		if err := msg.Decode(&blockHashes); err != nil {
+		iter := func() (hash []byte, ok bool) {
+			hash, err = msgStream.Bytes()
+			if err == nil {
+				ok = true
+			}
+			return
+		}
+		self.eth.AddBlockHashes(iter, self.id)
+		if err != nil && err != rlp.EOL {
 			return ProtocolError(ErrDecode, "%v", err)
 		}
-		fetchMore := true
-		for _, hash := range blockHashes {
-			fetchMore = self.eth.AddHash(hash, self.peer)
-			if !fetchMore {
-				break
-			}
-		}
-		if fetchMore {
-			return self.FetchHashes(blockHashes[len(blockHashes)-1])
-		}
 
 	case GetBlocksMsg:
-		// Limit to max 300 blocks
 		var blockHashes [][]byte
 		if err := msg.Decode(&blockHashes); err != nil {
 			return ProtocolError(ErrDecode, "%v", err)
 		}
-		max := int(math.Min(float64(len(blockHashes)), 300.0))
+		max := int(math.Min(float64(len(blockHashes)), blockHashesBatchSize))
 		var blocks []interface{}
 		for i, hash := range blockHashes {
 			if i >= max {
@@ -184,20 +178,19 @@ func (self *ethProtocol) handle() error {
 		return self.rw.EncodeMsg(BlocksMsg, blocks...)
 
 	case BlocksMsg:
-		var blocks []*types.Block
+		msgStream := rlp.NewListStream(msg.Payload, uint64(msg.Size))
-		if err := msg.Decode(&blocks); err != nil {
+		for {
+			var block *types.Block
+			if err := msgStream.Decode(&block); err != nil {
+				if err == rlp.EOL {
+					break
+				} else {
 					return ProtocolError(ErrDecode, "%v", err)
 				}
-		for _, block := range blocks {
+			}
-			fetchHashes, err := self.eth.AddBlock(nil, block, self.peer)
+			if err := self.eth.AddBlock(block, self.id); err != nil {
-			if err != nil {
 				return ProtocolError(ErrInvalidBlock, "%v", err)
 			}
-			if fetchHashes {
-				if err := self.FetchHashes(block.Hash()); err != nil {
-					return err
-				}
-			}
 		}
 
 	case NewBlockMsg:
@@ -205,13 +198,24 @@ func (self *ethProtocol) handle() error {
 		if err := msg.Decode(&request); err != nil {
 			return ProtocolError(ErrDecode, "%v", err)
 		}
-		var fetchHashes bool
+		hash := request.Block.Hash()
-		// this should reset td and offer blockpool as candidate new peer?
+		// to simplify backend interface adding a new block
-		if fetchHashes, err = self.eth.AddBlock(request.TD, request.Block, self.peer); err != nil {
+		// uses AddPeer followed by AddHashes, AddBlock only if peer is the best peer
+		// (or selected as new best peer)
+		if self.eth.AddPeer(request.TD, hash, self.id, self.requestBlockHashes, self.requestBlocks, self.invalidBlock) {
+			called := true
+			iter := func() (hash []byte, ok bool) {
+				if called {
+					called = false
+					return hash, true
+				} else {
+					return
+				}
+			}
+			self.eth.AddBlockHashes(iter, self.id)
+			if err := self.eth.AddBlock(request.Block, self.id); err != nil {
 				return ProtocolError(ErrInvalidBlock, "%v", err)
 			}
-		if fetchHashes {
-			return self.FetchHashes(request.Block.Hash())
 		}
 
 	default:
@@ -279,16 +283,34 @@ func (self *ethProtocol) handleStatus() error {
 		return ProtocolError(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, ProtocolVersion)
 	}
 
-	logger.Infof("Peer is [eth] capable (%d/%d). TD = %v ~ %x", status.ProtocolVersion, status.NetworkId, status.CurrentBlock)
+	self.peer.Infof("Peer is [eth] capable (%d/%d). TD = %v ~ %x", status.ProtocolVersion, status.NetworkId, status.CurrentBlock)
 
-	if self.eth.AddPeer(status.TD, status.CurrentBlock, self.peer) {
+	self.eth.AddPeer(status.TD, status.CurrentBlock, self.id, self.requestBlockHashes, self.requestBlocks, self.invalidBlock)
-		return self.FetchHashes(status.CurrentBlock)
-	}
 
 	return nil
 }
 
-func (self *ethProtocol) FetchHashes(from []byte) error {
+func (self *ethProtocol) requestBlockHashes(from []byte) error {
-	logger.Debugf("Fetching hashes (%d) %x...\n", blockHashesBatchSize, from[0:4])
+	self.peer.Debugf("fetching hashes (%d) %x...\n", blockHashesBatchSize, from[0:4])
 	return self.rw.EncodeMsg(GetBlockHashesMsg, from, blockHashesBatchSize)
 }
+
+func (self *ethProtocol) requestBlocks(hashes [][]byte) error {
+	self.peer.Debugf("fetching %v blocks", len(hashes))
+	return self.rw.EncodeMsg(GetBlocksMsg, ethutil.ByteSliceToInterface(hashes))
+}
+
+func (self *ethProtocol) invalidBlock(err error) {
+	ProtocolError(ErrInvalidBlock, "%v", err)
+	self.peer.Disconnect(p2p.DiscSubprotocolError)
+}
+
+func (self *ethProtocol) protoError(code int, format string, params ...interface{}) (err *protocolError) {
+	err = ProtocolError(code, format, params...)
+	if err.Fatal() {
+		self.peer.Errorln(err)
+	} else {
+		self.peer.Debugln(err)
+	}
+	return
+}

eth/protocol_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p"
 )
 
@@ -55,10 +56,11 @@ type TestBackend struct {
 	getTransactions func() []*types.Transaction
 	addTransactions func(txs []*types.Transaction)
 	getBlockHashes  func(hash []byte, amount uint32) (hashes [][]byte)
-	addHash         func(hash []byte, peer *p2p.Peer) (more bool)
+	addBlockHashes  func(next func() ([]byte, bool), peerId string)
 	getBlock        func(hash []byte) *types.Block
-	addBlock        func(td *big.Int, block *types.Block, peer *p2p.Peer) (fetchHashes bool, err error)
+	addBlock        func(block *types.Block, peerId string) (err error)
-	addPeer         func(td *big.Int, currentBlock []byte, peer *p2p.Peer) (fetchHashes bool)
+	addPeer         func(td *big.Int, currentBlock []byte, peerId string, requestHashes func([]byte) error, requestBlocks func([][]byte) error, invalidBlock func(error)) (best bool)
+	removePeer      func(peerId string)
 	status          func() (td *big.Int, currentBlock []byte, genesisBlock []byte)
 }
 
@@ -82,12 +84,12 @@ func (self *TestBackend) GetBlockHashes(hash []byte, amount uint32) (hashes [][]
 	return
 }
 
-func (self *TestBackend) AddHash(hash []byte, peer *p2p.Peer) (more bool) {
+func (self *TestBackend) AddBlockHashes(next func() ([]byte, bool), peerId string) {
-	if self.addHash != nil {
+	if self.addBlockHashes != nil {
-		more = self.addHash(hash, peer)
+		self.addBlockHashes(next, peerId)
 	}
-	return
 }
+
 func (self *TestBackend) GetBlock(hash []byte) (block *types.Block) {
 	if self.getBlock != nil {
 		block = self.getBlock(hash)
@@ -95,20 +97,26 @@ func (self *TestBackend) GetBlock(hash []byte) (block *types.Block) {
 	return
 }
 
-func (self *TestBackend) AddBlock(td *big.Int, block *types.Block, peer *p2p.Peer) (fetchHashes bool, err error) {
+func (self *TestBackend) AddBlock(block *types.Block, peerId string) (err error) {
 	if self.addBlock != nil {
-		fetchHashes, err = self.addBlock(td, block, peer)
+		err = self.addBlock(block, peerId)
 	}
 	return
 }
 
-func (self *TestBackend) AddPeer(td *big.Int, currentBlock []byte, peer *p2p.Peer) (fetchHashes bool) {
+func (self *TestBackend) AddPeer(td *big.Int, currentBlock []byte, peerId string, requestBlockHashes func([]byte) error, requestBlocks func([][]byte) error, invalidBlock func(error)) (best bool) {
 	if self.addPeer != nil {
-		fetchHashes = self.addPeer(td, currentBlock, peer)
+		best = self.addPeer(td, currentBlock, peerId, requestBlockHashes, requestBlocks, invalidBlock)
 	}
 	return
 }
 
+func (self *TestBackend) RemovePeer(peerId string) {
+	if self.removePeer != nil {
+		self.removePeer(peerId)
+	}
+}
+
 func (self *TestBackend) Status() (td *big.Int, currentBlock []byte, genesisBlock []byte) {
 	if self.status != nil {
 		td, currentBlock, genesisBlock = self.status()
@@ -116,13 +124,35 @@ func (self *TestBackend) Status() (td *big.Int, currentBlock []byte, genesisBloc
 	return
 }
 
-func TestEth(t *testing.T) {
+// TODO: refactor this into p2p/client_identity
+type peerId struct {
+	pubkey []byte
+}
+
+func (self *peerId) String() string {
+	return "test peer"
+}
+
+func (self *peerId) Pubkey() (pubkey []byte) {
+	pubkey = self.pubkey
+	if len(pubkey) == 0 {
+		pubkey = crypto.GenerateNewKeyPair().PublicKey
+		self.pubkey = pubkey
+	}
+	return
+}
+
+func testPeer() *p2p.Peer {
+	return p2p.NewPeer(&peerId{}, []p2p.Cap{})
+}
+
+func TestErrNoStatusMsg(t *testing.T) {
 	quit := make(chan bool)
 	rw := &testMsgReadWriter{make(chan p2p.Msg, 10), make(chan p2p.Msg, 10)}
 	testBackend := &TestBackend{}
 	var err error
 	go func() {
-		err = runEthProtocol(testBackend, nil, rw)
+		err = runEthProtocol(testBackend, testPeer(), rw)
 		close(quit)
 	}()
 	statusMsg := p2p.NewMsg(4)