eth, eth/fetcher: move propagated block import into fetcher

4 files changed, 106 insertions, 123 deletions

diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index 18e5f50e8..39976aae1 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -99,7 +99,7 @@ type Downloader struct {
 	hasBlock    hashCheckFn      // Checks if a block is present in the chain
 	getBlock    blockRetrievalFn // Retrieves a block from the chain
 	insertChain chainInsertFn    // Injects a batch of blocks into the chain
-	dropPeer    peerDropFn       // Retrieved the TD of our own chain
+	dropPeer    peerDropFn       // Drops a peer for misbehaving
 
 	// Status
 	synchroniseMock func(id string, hash common.Hash) error // Replacement for synchronise during testing
diff --git a/eth/fetcher/fetcher.go b/eth/fetcher/fetcher.go
index a70fcbeed..c96471554 100644
--- a/eth/fetcher/fetcher.go
+++ b/eth/fetcher/fetcher.go
@@ -29,12 +29,18 @@ type hashCheckFn func(common.Hash) bool
 // blockRequesterFn is a callback type for sending a block retrieval request.
 type blockRequesterFn func([]common.Hash) error
 
-// blockImporterFn is a callback type for trying to inject a block into the local chain.
-type blockImporterFn func(peer string, block *types.Block) error
+// blockBroadcasterFn is a callback type for broadcasting a block to connected peers.
+type blockBroadcasterFn func(block *types.Block)
 
 // chainHeightFn is a callback type to retrieve the current chain height.
 type chainHeightFn func() uint64
 
+// chainInsertFn is a callback type to insert a batch of blocks into the local chain.
+type chainInsertFn func(types.Blocks) (int, error)
+
+// peerDropFn is a callback type for dropping a peer detected as malicious.
+type peerDropFn func(id string)
+
 // announce is the hash notification of the availability of a new block in the
 // network.
 type announce struct {
@@ -70,26 +76,30 @@ type Fetcher struct {
 	queued map[common.Hash]struct{} // Presence set of already queued blocks (to dedup imports)
 
 	// Callbacks
-	hasBlock    hashCheckFn     // Checks if a block is present in the chain
-	importBlock blockImporterFn // Injects a block from an origin peer into the chain
-	chainHeight chainHeightFn   // Retrieves the current chain's height
+	hasBlock       hashCheckFn        // Checks if a block is present in the chain
+	broadcastBlock blockBroadcasterFn // Broadcasts a block to connected peers
+	chainHeight    chainHeightFn      // Retrieves the current chain's height
+	insertChain    chainInsertFn      // Injects a batch of blocks into the chain
+	dropPeer       peerDropFn         // Drops a peer for misbehaving
 }
 
 // New creates a block fetcher to retrieve blocks based on hash announcements.
-func New(hasBlock hashCheckFn, importBlock blockImporterFn, chainHeight chainHeightFn) *Fetcher {
+func New(hasBlock hashCheckFn, broadcastBlock blockBroadcasterFn, chainHeight chainHeightFn, insertChain chainInsertFn, dropPeer peerDropFn) *Fetcher {
 	return &Fetcher{
-		notify:      make(chan *announce),
-		inject:      make(chan *inject),
-		filter:      make(chan chan []*types.Block),
-		done:        make(chan common.Hash),
-		quit:        make(chan struct{}),
-		announced:   make(map[common.Hash][]*announce),
-		fetching:    make(map[common.Hash]*announce),
-		queue:       prque.New(),
-		queued:      make(map[common.Hash]struct{}),
-		hasBlock:    hasBlock,
-		importBlock: importBlock,
-		chainHeight: chainHeight,
+		notify:         make(chan *announce),
+		inject:         make(chan *inject),
+		filter:         make(chan chan []*types.Block),
+		done:           make(chan common.Hash),
+		quit:           make(chan struct{}),
+		announced:      make(map[common.Hash][]*announce),
+		fetching:       make(map[common.Hash]*announce),
+		queue:          prque.New(),
+		queued:         make(map[common.Hash]struct{}),
+		hasBlock:       hasBlock,
+		broadcastBlock: broadcastBlock,
+		chainHeight:    chainHeight,
+		insertChain:    insertChain,
+		dropPeer:       dropPeer,
 	}
 }
 
@@ -328,10 +338,17 @@ func (f *Fetcher) insert(peer string, block *types.Block) {
 	go func() {
 		defer func() { f.done <- hash }()
 
+		// If the parent's unknown, abort insertion
+		if !f.hasBlock(block.ParentHash()) {
+			return
+		}
 		// Run the actual import and log any issues
-		if err := f.importBlock(peer, block); err != nil {
+		if _, err := f.insertChain(types.Blocks{block}); err != nil {
 			glog.V(logger.Detail).Infof("Peer %s: block #%d [%x] import failed: %v", peer, block.NumberU64(), hash[:4], err)
+			f.dropPeer(peer)
 			return
 		}
+		// If import succeeded, broadcast the block
+		go f.broadcastBlock(block)
 	}()
 }
diff --git a/eth/fetcher/fetcher_test.go b/eth/fetcher/fetcher_test.go
index 4c6a1bf6a..3e8df1804 100644
--- a/eth/fetcher/fetcher_test.go
+++ b/eth/fetcher/fetcher_test.go
@@ -80,7 +80,7 @@ func newTester() *fetcherTester {
 		hashes: []common.Hash{knownHash},
 		blocks: map[common.Hash]*types.Block{knownHash: genesis},
 	}
-	tester.fetcher = New(tester.hasBlock, tester.importBlock, tester.chainHeight)
+	tester.fetcher = New(tester.hasBlock, tester.broadcastBlock, tester.chainHeight, tester.insertChain, tester.dropPeer)
 	tester.fetcher.Start()
 
 	return tester
@@ -95,23 +95,8 @@ func (f *fetcherTester) hasBlock(hash common.Hash) bool {
 	return ok
 }
 
-// importBlock injects a new blocks into the simulated chain.
-func (f *fetcherTester) importBlock(peer string, block *types.Block) error {
-	f.lock.Lock()
-	defer f.lock.Unlock()
-
-	// Make sure the parent in known
-	if _, ok := f.blocks[block.ParentHash()]; !ok {
-		return errors.New("unknown parent")
-	}
-	// Discard any new blocks if the same height already exists
-	if block.NumberU64() <= f.blocks[f.hashes[len(f.hashes)-1]].NumberU64() {
-		return nil
-	}
-	// Otherwise build our current chain
-	f.hashes = append(f.hashes, block.Hash())
-	f.blocks[block.Hash()] = block
-	return nil
+// broadcastBlock is a nop placeholder for the block broadcasting.
+func (f *fetcherTester) broadcastBlock(block *types.Block) {
 }
 
 // chainHeight retrieves the current height (block number) of the chain.
@@ -122,6 +107,31 @@ func (f *fetcherTester) chainHeight() uint64 {
 	return f.blocks[f.hashes[len(f.hashes)-1]].NumberU64()
 }
 
+// insertChain injects a new blocks into the simulated chain.
+func (f *fetcherTester) insertChain(blocks types.Blocks) (int, error) {
+	f.lock.Lock()
+	defer f.lock.Unlock()
+
+	for i, block := range blocks {
+		// Make sure the parent in known
+		if _, ok := f.blocks[block.ParentHash()]; !ok {
+			return i, errors.New("unknown parent")
+		}
+		// Discard any new blocks if the same height already exists
+		if block.NumberU64() <= f.blocks[f.hashes[len(f.hashes)-1]].NumberU64() {
+			return i, nil
+		}
+		// Otherwise build our current chain
+		f.hashes = append(f.hashes, block.Hash())
+		f.blocks[block.Hash()] = block
+	}
+	return 0, nil
+}
+
+// dropPeer is a nop placeholder for the peer removal.
+func (f *fetcherTester) dropPeer(peer string) {
+}
+
 // peerFetcher retrieves a fetcher associated with a simulated peer.
 func (f *fetcherTester) makeFetcher(blocks map[common.Hash]*types.Block) blockRequesterFn {
 	// Copy all the blocks to ensure they are not tampered with
@@ -330,9 +340,9 @@ func TestImportDeduplication(t *testing.T) {
 	fetcher := tester.makeFetcher(blocks)
 
 	counter := uint32(0)
-	tester.fetcher.importBlock = func(peer string, block *types.Block) error {
-		atomic.AddUint32(&counter, 1)
-		return tester.importBlock(peer, block)
+	tester.fetcher.insertChain = func(blocks types.Blocks) (int, error) {
+		atomic.AddUint32(&counter, uint32(len(blocks)))
+		return tester.insertChain(blocks)
 	}
 	// Announce the duplicating block, wait for retrieval, and also propagate directly
 	tester.fetcher.Notify("valid", hashes[0], time.Now().Add(-arriveTimeout), fetcher)
@@ -400,18 +410,18 @@ func TestCompetingImports(t *testing.T) {
 
 	first := int32(1)
 	height := uint64(1)
-	tester.fetcher.importBlock = func(peer string, block *types.Block) error {
+	tester.fetcher.insertChain = func(blocks types.Blocks) (int, error) {
 		// Check for any phase reordering
-		if prev := atomic.LoadUint64(&height); block.NumberU64() < prev {
-			t.Errorf("phase reversal: have %v, want %v", block.NumberU64(), prev)
+		if prev := atomic.LoadUint64(&height); blocks[0].NumberU64() < prev {
+			t.Errorf("phase reversal: have %v, want %v", blocks[0].NumberU64(), prev)
 		}
-		atomic.StoreUint64(&height, block.NumberU64())
+		atomic.StoreUint64(&height, blocks[0].NumberU64())
 
 		// Sleep a bit on the first import not to race with the enqueues
 		if atomic.CompareAndSwapInt32(&first, 1, 0) {
 			time.Sleep(50 * time.Millisecond)
 		}
-		return tester.importBlock(peer, block)
+		return tester.insertChain(blocks)
 	}
 	// Queue up everything but with a missing link
 	for i := 0; i < len(hashesA)-2; i++ {
diff --git a/eth/handler.go b/eth/handler.go
index b62815532..eeb6a4f14 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -1,10 +1,8 @@
 package eth
 
 import (
-	"errors"
 	"fmt"
 	"math"
-	"math/big"
 	"sync"
 	"time"
 
@@ -93,16 +91,10 @@ func NewProtocolManager(protocolVersion, networkId int, mux *event.TypeMux, txpo
 	// Construct the different synchronisation mechanisms
 	manager.downloader = downloader.New(manager.eventMux, manager.chainman.HasBlock, manager.chainman.GetBlock, manager.chainman.InsertChain, manager.removePeer)
 
-	importer := func(peer string, block *types.Block) error {
-		if p := manager.peers.Peer(peer); p != nil {
-			return manager.importBlock(manager.peers.Peer(peer), block, nil)
-		}
-		return errors.New("unknown peer")
-	}
 	heighter := func() uint64 {
 		return manager.chainman.CurrentBlock().NumberU64()
 	}
-	manager.fetcher = fetcher.New(manager.chainman.HasBlock, importer, heighter)
+	manager.fetcher = fetcher.New(manager.chainman.HasBlock, manager.BroadcastBlock, heighter, manager.chainman.InsertChain, manager.removePeer)
 
 	return manager
 }
@@ -194,7 +186,7 @@ func (pm *ProtocolManager) handle(p *peer) error {
 	return nil
 }
 
-func (self *ProtocolManager) handleMsg(p *peer) error {
+func (pm *ProtocolManager) handleMsg(p *peer) error {
 	msg, err := p.rw.ReadMsg()
 	if err != nil {
 		return err
@@ -224,7 +216,7 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 				RemoteId: p.ID().String(),
 			})
 		}
-		self.txpool.AddTransactions(txs)
+		pm.txpool.AddTransactions(txs)
 
 	case GetBlockHashesMsg:
 		var request getBlockHashesMsgData
@@ -236,7 +228,7 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 			request.Amount = uint64(downloader.MaxHashFetch)
 		}
 
-		hashes := self.chainman.GetBlockHashesFromHash(request.Hash, request.Amount)
+		hashes := pm.chainman.GetBlockHashesFromHash(request.Hash, request.Amount)
 
 		if glog.V(logger.Debug) {
 			if len(hashes) == 0 {
@@ -254,7 +246,7 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 		if err := msgStream.Decode(&hashes); err != nil {
 			break
 		}
-		err := self.downloader.DeliverHashes(p.id, hashes)
+		err := pm.downloader.DeliverHashes(p.id, hashes)
 		if err != nil {
 			glog.V(logger.Debug).Infoln(err)
 		}
@@ -280,7 +272,7 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 				return errResp(ErrDecode, "msg %v: %v", msg, err)
 			}
 
-			block := self.chainman.GetBlock(hash)
+			block := pm.chainman.GetBlock(hash)
 			if block != nil {
 				blocks = append(blocks, block)
 				totalsize += block.Size()
@@ -301,8 +293,8 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 			blocks = nil
 		}
 		// Filter out any explicitly requested blocks, deliver the rest to the downloader
-		if blocks := self.fetcher.Filter(blocks); len(blocks) > 0 {
-			self.downloader.DeliverBlocks(p.id, blocks)
+		if blocks := pm.fetcher.Filter(blocks); len(blocks) > 0 {
+			pm.downloader.DeliverBlocks(p.id, blocks)
 		}
 
 	case NewBlockHashesMsg:
@@ -321,15 +313,16 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 		// Schedule all the unknown hashes for retrieval
 		unknown := make([]common.Hash, 0, len(hashes))
 		for _, hash := range hashes {
-			if !self.chainman.HasBlock(hash) {
+			if !pm.chainman.HasBlock(hash) {
 				unknown = append(unknown, hash)
 			}
 		}
 		for _, hash := range unknown {
-			self.fetcher.Notify(p.id, hash, time.Now(), p.requestBlocks)
+			pm.fetcher.Notify(p.id, hash, time.Now(), p.requestBlocks)
 		}
 
 	case NewBlockMsg:
+		// Retrieve and decode the propagated block
 		var request newBlockMsgData
 		if err := msg.Decode(&request); err != nil {
 			return errResp(ErrDecode, "%v: %v", msg, err)
@@ -339,11 +332,24 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 		}
 		request.Block.ReceivedAt = msg.ReceivedAt
 
-		// Try to import the propagated block, also making it fill any fetcher gaps
-		self.fetcher.Enqueue(p.id, request.Block)
-		if err := self.importBlock(p, request.Block, request.TD); err != nil {
-			return err
-		}
+		// Mark the block's arrival for whatever reason
+		_, chainHead, _ := pm.chainman.Status()
+		jsonlogger.LogJson(&logger.EthChainReceivedNewBlock{
+			BlockHash:     request.Block.Hash().Hex(),
+			BlockNumber:   request.Block.Number(),
+			ChainHeadHash: chainHead.Hex(),
+			BlockPrevHash: request.Block.ParentHash().Hex(),
+			RemoteId:      p.ID().String(),
+		})
+		// Mark the peer as owning the block and schedule it for import
+		p.blockHashes.Add(request.Block.Hash())
+		p.SetHead(request.Block.Hash())
+
+		pm.fetcher.Enqueue(p.id, request.Block)
+
+		// TODO: Schedule a sync to cover potential gaps (this needs proto update)
+		p.SetTd(request.TD)
+		go pm.synchronise(p)
 
 	default:
 		return errResp(ErrInvalidMsgCode, "%v", msg.Code)
@@ -351,61 +357,11 @@ func (self *ProtocolManager) handleMsg(p *peer) error {
 	return nil
 }
 
-// importBlocks injects a new block retrieved from the given peer into the chain
-// manager.
-func (pm *ProtocolManager) importBlock(p *peer, block *types.Block, td *big.Int) error {
-	hash := block.Hash()
-
-	// Mark the block as present at the remote node (don't duplicate already held data)
-	p.blockHashes.Add(hash)
-	p.SetHead(hash)
-	if td != nil {
-		p.SetTd(td)
-	}
-	// Log the block's arrival
-	_, chainHead, _ := pm.chainman.Status()
-	jsonlogger.LogJson(&logger.EthChainReceivedNewBlock{
-		BlockHash:     hash.Hex(),
-		BlockNumber:   block.Number(),
-		ChainHeadHash: chainHead.Hex(),
-		BlockPrevHash: block.ParentHash().Hex(),
-		RemoteId:      p.ID().String(),
-	})
-	// If the block's already known or its difficulty is lower than ours, drop
-	if pm.chainman.HasBlock(hash) {
-		p.SetTd(pm.chainman.GetBlock(hash).Td) // update the peer's TD to the real value
-		return nil
-	}
-	if td != nil && pm.chainman.Td().Cmp(td) > 0 && new(big.Int).Add(block.Number(), big.NewInt(7)).Cmp(pm.chainman.CurrentBlock().Number()) < 0 {
-		glog.V(logger.Debug).Infof("[%s] dropped block %v due to low TD %v\n", p.id, block.Number(), td)
-		return nil
-	}
-	// Attempt to insert the newly received block and propagate to our peers
-	if pm.chainman.HasBlock(block.ParentHash()) {
-		if _, err := pm.chainman.InsertChain(types.Blocks{block}); err != nil {
-			glog.V(logger.Error).Infoln("removed peer (", p.id, ") due to block error", err)
-			return err
-		}
-		if td != nil && block.Td.Cmp(td) != 0 {
-			err := fmt.Errorf("invalid TD on block(%v) from peer(%s): block.td=%v, request.td=%v", block.Number(), p.id, block.Td, td)
-			glog.V(logger.Error).Infoln(err)
-			return err
-		}
-		pm.BroadcastBlock(hash, block)
-		return nil
-	}
-	// Parent of the block is unknown, try to sync with this peer if it seems to be good
-	if td != nil {
-		go pm.synchronise(p)
-	}
-	return nil
-}
-
 // BroadcastBlock will propagate the block to a subset of its connected peers,
 // only notifying the rest of the block's appearance.
-func (pm *ProtocolManager) BroadcastBlock(hash common.Hash, block *types.Block) {
+func (pm *ProtocolManager) BroadcastBlock(block *types.Block) {
 	// Retrieve all the target peers and split between full broadcast or only notification
-	peers := pm.peers.PeersWithoutBlock(hash)
+	peers := pm.peers.PeersWithoutBlock(block.Hash())
 	split := int(math.Sqrt(float64(len(peers))))
 
 	transfer := peers[:split]
@@ -413,7 +369,7 @@ func (pm *ProtocolManager) BroadcastBlock(hash common.Hash, block *types.Block)
 
 	// Send out the data transfers and the notifications
 	for _, peer := range notify {
-		peer.sendNewBlockHashes([]common.Hash{hash})
+		peer.sendNewBlockHashes([]common.Hash{block.Hash()})
 	}
 	glog.V(logger.Detail).Infoln("broadcast hash to", len(notify), "peers.")
 
@@ -442,7 +398,7 @@ func (self *ProtocolManager) minedBroadcastLoop() {
 	for obj := range self.minedBlockSub.Chan() {
 		switch ev := obj.(type) {
 		case core.NewMinedBlockEvent:
-			self.BroadcastBlock(ev.Block.Hash(), ev.Block)
+			self.BroadcastBlock(ev.Block)
 		}
 	}
 }