1 files changed, 323 insertions, 0 deletions
diff --git a/eth/handler.go b/eth/handler.go
new file mode 100644
index 000000000..749809175
--- /dev/null
+++ b/eth/handler.go
@@ -0,0 +1,323 @@
+package eth
+
+// XXX Fair warning, most of the code is re-used from the old protocol. Please be aware that most of this will actually change
+// The idea is that most of the calls within the protocol will become synchronous.
+// Block downloading and block processing will be complete seperate processes
+/*
+# Possible scenarios
+
+// Synching scenario
+// Use the best peer to synchronise
+blocks, err := pm.downloader.Synchronise()
+if err != nil {
+	// handle
+	break
+}
+pm.chainman.InsertChain(blocks)
+
+// Receiving block with known parent
+if parent_exist {
+	if err := pm.chainman.InsertChain(block); err != nil {
+		// handle
+		break
+	}
+	pm.BroadcastBlock(block)
+}
+
+// Receiving block with unknown parent
+blocks, err := pm.downloader.SynchroniseWithPeer(peer)
+if err != nil {
+	// handle
+	break
+}
+pm.chainman.InsertChain(blocks)
+
+*/
+
+import (
+	"fmt"
+	"math"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+func errResp(code errCode, format string, v ...interface{}) error {
+	return fmt.Errorf("%v - %v", code, fmt.Sprintf(format, v...))
+}
+
+type hashFetcherFn func(common.Hash) error
+type blockFetcherFn func([]common.Hash) error
+
+// extProt is an interface which is passed around so we can expose GetHashes and GetBlock without exposing it to the rest of the protocol
+// extProt is passed around to peers which require to GetHashes and GetBlocks
+type extProt struct {
+	getHashes hashFetcherFn
+	getBlocks blockFetcherFn
+}
+
+func (ep extProt) GetHashes(hash common.Hash) error    { return ep.getHashes(hash) }
+func (ep extProt) GetBlock(hashes []common.Hash) error { return ep.getBlocks(hashes) }
+
+type ProtocolManager struct {
+	protVer, netId int
+	txpool         txPool
+	chainman       *core.ChainManager
+	downloader     *downloader.Downloader
+
+	pmu   sync.Mutex
+	peers map[string]*peer
+
+	SubProtocol p2p.Protocol
+}
+
+// NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
+// with the ethereum network.
+func NewProtocolManager(protocolVersion, networkId int, txpool txPool, chainman *core.ChainManager, downloader *downloader.Downloader) *ProtocolManager {
+	manager := &ProtocolManager{
+		txpool:     txpool,
+		chainman:   chainman,
+		downloader: downloader,
+		peers:      make(map[string]*peer),
+	}
+
+	manager.SubProtocol = p2p.Protocol{
+		Name:    "eth",
+		Version: uint(protocolVersion),
+		Length:  ProtocolLength,
+		Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
+			peer := manager.newPeer(protocolVersion, networkId, p, rw)
+			err := manager.handle(peer)
+			//glog.V(logger.Detail).Infof("[%s]: %v\n", peer.id, err)
+
+			return err
+		},
+	}
+
+	return manager
+}
+
+func (pm *ProtocolManager) newPeer(pv, nv int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
+
+	td, current, genesis := pm.chainman.Status()
+
+	return newPeer(pv, nv, genesis, current, td, p, rw)
+}
+
+func (pm *ProtocolManager) handle(p *peer) error {
+	if err := p.handleStatus(); err != nil {
+		return err
+	}
+	pm.pmu.Lock()
+	pm.peers[p.id] = p
+	pm.pmu.Unlock()
+
+	pm.downloader.RegisterPeer(p.id, p.td, p.currentHash, p.requestHashes, p.requestBlocks)
+	defer func() {
+		pm.pmu.Lock()
+		defer pm.pmu.Unlock()
+		delete(pm.peers, p.id)
+		pm.downloader.UnregisterPeer(p.id)
+	}()
+
+	// propagate existing transactions. new transactions appearing
+	// after this will be sent via broadcasts.
+	if err := p.sendTransactions(pm.txpool.GetTransactions()); err != nil {
+		return err
+	}
+
+	// main loop. handle incoming messages.
+	for {
+		if err := pm.handleMsg(p); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (self *ProtocolManager) handleMsg(p *peer) error {
+	msg, err := p.rw.ReadMsg()
+	if err != nil {
+		return err
+	}
+	if msg.Size > ProtocolMaxMsgSize {
+		return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
+	}
+	// make sure that the payload has been fully consumed
+	defer msg.Discard()
+
+	switch msg.Code {
+	case GetTxMsg: // ignore
+	case StatusMsg:
+		return errResp(ErrExtraStatusMsg, "uncontrolled status message")
+
+	case TxMsg:
+		// TODO: rework using lazy RLP stream
+		var txs []*types.Transaction
+		if err := msg.Decode(&txs); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		for i, tx := range txs {
+			if tx == nil {
+				return errResp(ErrDecode, "transaction %d is nil", i)
+			}
+			jsonlogger.LogJson(&logger.EthTxReceived{
+				TxHash:   tx.Hash().Hex(),
+				RemoteId: p.ID().String(),
+			})
+		}
+		self.txpool.AddTransactions(txs)
+
+	case GetBlockHashesMsg:
+		var request getBlockHashesMsgData
+		if err := msg.Decode(&request); err != nil {
+			return errResp(ErrDecode, "->msg %v: %v", msg, err)
+		}
+
+		if request.Amount > maxHashes {
+			request.Amount = maxHashes
+		}
+		hashes := self.chainman.GetBlockHashesFromHash(request.Hash, request.Amount)
+		return p.sendBlockHashes(hashes)
+	case BlockHashesMsg:
+		msgStream := rlp.NewStream(msg.Payload)
+
+		var hashes []common.Hash
+		if err := msgStream.Decode(&hashes); err != nil {
+			break
+		}
+		err := self.downloader.AddHashes(p.id, hashes)
+		if err != nil {
+			glog.V(logger.Debug).Infoln(err)
+		}
+
+	case GetBlocksMsg:
+		msgStream := rlp.NewStream(msg.Payload)
+		if _, err := msgStream.List(); err != nil {
+			return err
+		}
+
+		var blocks []*types.Block
+		var i int
+		for {
+			i++
+			var hash common.Hash
+			err := msgStream.Decode(&hash)
+			if err == rlp.EOL {
+				break
+			} else if err != nil {
+				return errResp(ErrDecode, "msg %v: %v", msg, err)
+			}
+
+			block := self.chainman.GetBlock(hash)
+			if block != nil {
+				blocks = append(blocks, block)
+			}
+			if i == maxBlocks {
+				break
+			}
+		}
+		return p.sendBlocks(blocks)
+	case BlocksMsg:
+		msgStream := rlp.NewStream(msg.Payload)
+
+		var blocks []*types.Block
+		if err := msgStream.Decode(&blocks); err != nil {
+			glog.V(logger.Detail).Infoln("Decode error", err)
+			blocks = nil
+		}
+		self.downloader.DeliverChunk(p.id, blocks)
+
+	case NewBlockMsg:
+		var request newBlockMsgData
+		if err := msg.Decode(&request); err != nil {
+			return errResp(ErrDecode, "%v: %v", msg, err)
+		}
+		if err := request.Block.ValidateFields(); err != nil {
+			return errResp(ErrDecode, "block validation %v: %v", msg, err)
+		}
+		hash := request.Block.Hash()
+		// Add the block hash as a known hash to the peer. This will later be used to detirmine
+		// who should receive this.
+		p.blockHashes.Add(hash)
+
+		_, chainHead, _ := self.chainman.Status()
+
+		jsonlogger.LogJson(&logger.EthChainReceivedNewBlock{
+			BlockHash:     hash.Hex(),
+			BlockNumber:   request.Block.Number(), // this surely must be zero
+			ChainHeadHash: chainHead.Hex(),
+			BlockPrevHash: request.Block.ParentHash().Hex(),
+			RemoteId:      p.ID().String(),
+		})
+
+		// Make sure the block isn't already known. If this is the case simply drop
+		// the message and move on. If the TD is < currentTd; drop it as well. If this
+		// chain at some point becomes canonical, the downloader will fetch it.
+		if self.chainman.HasBlock(hash) {
+			break
+		}
+		/* XXX unsure about this
+		if self.chainman.Td().Cmp(request.TD) > 0 && new(big.Int).Add(request.Block.Number(), big.NewInt(7)).Cmp(self.chainman.CurrentBlock().Number()) < 0 {
+			glog.V(logger.Debug).Infoln("dropped block", request.Block.Number(), "due to low TD", request.TD)
+			break
+		}
+		*/
+
+		// Attempt to insert the newly received by checking if the parent exists.
+		// if the parent exists we process the block and propagate to our peers
+		// if the parent does not exists we delegate to the downloader.
+		// NOTE we can reduce chatter by dropping blocks with Td < currentTd
+		if self.chainman.HasBlock(request.Block.ParentHash()) {
+			if err := self.chainman.InsertChain(types.Blocks{request.Block}); err != nil {
+				// handle error
+				return nil
+			}
+			self.BroadcastBlock(hash, request.Block)
+		} else {
+			// adding blocks is synchronous
+			go func() {
+				err := self.downloader.AddBlock(p.id, request.Block, request.TD)
+				if err != nil {
+					glog.V(logger.Detail).Infoln("downloader err:", err)
+					return
+				}
+				self.BroadcastBlock(hash, request.Block)
+			}()
+		}
+	default:
+		return errResp(ErrInvalidMsgCode, "%v", msg.Code)
+	}
+	return nil
+}
+
+// BroadcastBlock will propagate the block to its connected peers. It will sort
+// out which peers do not contain the block in their block set and will do a
+// sqrt(peers) to determine the amount of peers we broadcast to.
+func (pm *ProtocolManager) BroadcastBlock(hash common.Hash, block *types.Block) {
+	pm.pmu.Lock()
+	defer pm.pmu.Unlock()
+
+	// Find peers who don't know anything about the given hash. Peers that
+	// don't know about the hash will be a candidate for the broadcast loop
+	var peers []*peer
+	for _, peer := range pm.peers {
+		if !peer.blockHashes.Has(hash) {
+			peers = append(peers, peer)
+		}
+	}
+	// Broadcast block to peer set
+	peers = peers[:int(math.Sqrt(float64(len(peers))))]
+	for _, peer := range peers {
+		peer.sendNewBlock(block)
+	}
+	glog.V(logger.Detail).Infoln("broadcast block to", len(peers), "peers")
+}