les: light client protocol and API

common/mclock/mclock.go

+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// package mclock is a wrapper for a monotonic clock source
+package mclock
+
+import (
+	"time"
+
+	"github.com/aristanetworks/goarista/monotime"
+)
+
+type AbsTime time.Duration // absolute monotonic time
+
+func Now() AbsTime {
+	return AbsTime(monotime.Now())
+}

eth/api_backend.go

@@ -44,17 +44,17 @@ func (b *EthApiBackend) SetHead(number uint64) {
 	b.eth.blockchain.SetHead(number)
 }
 
-func (b *EthApiBackend) HeaderByNumber(blockNr rpc.BlockNumber) *types.Header {
+func (b *EthApiBackend) HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error) {
 	// Pending block is only known by the miner
 	if blockNr == rpc.PendingBlockNumber {
 		block, _ := b.eth.miner.Pending()
-		return block.Header()
+		return block.Header(), nil
 	}
 	// Otherwise resolve and return the block
 	if blockNr == rpc.LatestBlockNumber {
-		return b.eth.blockchain.CurrentBlock().Header()
+		return b.eth.blockchain.CurrentBlock().Header(), nil
 	}
-	return b.eth.blockchain.GetHeaderByNumber(uint64(blockNr))
+	return b.eth.blockchain.GetHeaderByNumber(uint64(blockNr)), nil
 }
 
 func (b *EthApiBackend) BlockByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Block, error) {
@@ -70,16 +70,16 @@ func (b *EthApiBackend) BlockByNumber(ctx context.Context, blockNr rpc.BlockNumb
 	return b.eth.blockchain.GetBlockByNumber(uint64(blockNr)), nil
 }
 
-func (b *EthApiBackend) StateAndHeaderByNumber(blockNr rpc.BlockNumber) (ethapi.State, *types.Header, error) {
+func (b *EthApiBackend) StateAndHeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (ethapi.State, *types.Header, error) {
 	// Pending state is only known by the miner
 	if blockNr == rpc.PendingBlockNumber {
 		block, state := b.eth.miner.Pending()
 		return EthApiState{state}, block.Header(), nil
 	}
 	// Otherwise resolve the block number and return its state
-	header := b.HeaderByNumber(blockNr)
-	if header == nil {
-		return nil, nil, nil
+	header, err := b.HeaderByNumber(ctx, blockNr)
+	if header == nil || err != nil {
+		return nil, nil, err
 	}
 	stateDb, err := b.eth.BlockChain().StateAt(header.Root)
 	return EthApiState{stateDb}, header, err

eth/backend.go

@@ -312,7 +312,7 @@ func (s *Ethereum) APIs() []rpc.API {
 		}, {
 			Namespace: "eth",
 			Version:   "1.0",
-			Service:   filters.NewPublicFilterAPI(s.chainDb, s.eventMux),
+			Service:   filters.NewPublicFilterAPI(s.ApiBackend, false),
 			Public:    true,
 		}, {
 			Namespace: "admin",

eth/filters/api.go

@@ -61,12 +61,14 @@ type PublicFilterAPI struct {
 }
 
 // NewPublicFilterAPI returns a new PublicFilterAPI instance.
-func NewPublicFilterAPI(chainDb ethdb.Database, mux *event.TypeMux) *PublicFilterAPI {
+func NewPublicFilterAPI(backend Backend, lightMode bool) *PublicFilterAPI {
 	api := &PublicFilterAPI{
-		mux:     mux,
-		chainDb: chainDb,
-		events:  NewEventSystem(mux),
-		filters: make(map[rpc.ID]*filter),
+		backend:   backend,
+		useMipMap: !lightMode,
+		mux:       backend.EventMux(),
+		chainDb:   backend.ChainDb(),
+		events:    NewEventSystem(backend.EventMux(), backend, lightMode),
+		filters:   make(map[rpc.ID]*filter),
 	}
 
 	go api.timeoutLoop()

eth/filters/filter.go

@@ -207,11 +207,15 @@ Logs:
 	return ret
 }
 
-func (f *Filter) bloomFilter(block *types.Block) bool {
-	if len(f.addresses) > 0 {
+func (f *Filter) bloomFilter(bloom types.Bloom) bool {
+	return bloomFilter(bloom, f.addresses, f.topics)
+}
+
+func bloomFilter(bloom types.Bloom, addresses []common.Address, topics [][]common.Hash) bool {
+	if len(addresses) > 0 {
 		var included bool
-		for _, addr := range f.addresses {
-			if types.BloomLookup(block.Bloom(), addr) {
+		for _, addr := range addresses {
+			if types.BloomLookup(bloom, addr) {
 				included = true
 				break
 			}
@@ -222,7 +226,7 @@ func (f *Filter) bloomFilter(block *types.Block) bool {
 		}
 	}
 
-	for _, sub := range f.topics {
+	for _, sub := range topics {
 		var included bool
 		for _, topic := range sub {
 			if (topic == common.Hash{}) || types.BloomLookup(block.Bloom(), topic) {

eth/filters/filter_system.go

@@ -31,6 +31,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/rpc"
+	"golang.org/x/net/context"
 )
 
 // Type determines the kind of filter and is used to put the filter in to
@@ -95,6 +96,9 @@ type subscription struct {
 type EventSystem struct {
 	mux       *event.TypeMux
 	sub       event.Subscription
+	backend   Backend
+	lightMode bool
+	lastHead  *types.Header
 	install   chan *subscription // install filter for event notification
 	uninstall chan *subscription // remove filter for event notification
 }
@@ -105,9 +109,11 @@ type EventSystem struct {
 //
 // The returned manager has a loop that needs to be stopped with the Stop function
 // or by stopping the given mux.
-func NewEventSystem(mux *event.TypeMux) *EventSystem {
+func NewEventSystem(mux *event.TypeMux, backend Backend, lightMode bool) *EventSystem {
 	m := &EventSystem{
 		mux:       mux,
+		backend:   backend,
+		lightMode: lightMode,
 		install:   make(chan *subscription),
 		uninstall: make(chan *subscription),
 	}
@@ -235,7 +241,7 @@ func (es *EventSystem) SubscribeNewHeads(headers chan *types.Header) *Subscripti
 type filterIndex map[Type]map[rpc.ID]*subscription
 
 // broadcast event to filters that match criteria.
-func broadcast(filters filterIndex, ev *event.Event) {
+func (es *EventSystem) broadcast(filters filterIndex, ev *event.Event) {
 	if ev == nil {
 		return
 	}
@@ -279,7 +285,77 @@ func broadcast(filters filterIndex, ev *event.Event) {
 				f.headers <- e.Block.Header()
 			}
 		}
+		if es.lightMode && len(filters[LogsSubscription]) > 0 {
+			es.lightFilterNewHead(e.Block.Header(), func(header *types.Header, remove bool) {
+				for _, f := range filters[LogsSubscription] {
+					if ev.Time.After(f.created) {
+						if matchedLogs := es.lightFilterLogs(header, f.logsCrit.Addresses, f.logsCrit.Topics, remove); len(matchedLogs) > 0 {
+							f.logs <- matchedLogs
+						}
+					}
+				}
+			})
+		}
+	}
+}
+
+func (es *EventSystem) lightFilterNewHead(newHeader *types.Header, callBack func(*types.Header, bool)) {
+	oldh := es.lastHead
+	es.lastHead = newHeader
+	if oldh == nil {
+		return
+	}
+	newh := newHeader
+	// find common ancestor, create list of rolled back and new block hashes
+	var oldHeaders, newHeaders []*types.Header
+	for oldh.Hash() != newh.Hash() {
+		if oldh.GetNumberU64() >= newh.GetNumberU64() {
+			oldHeaders = append(oldHeaders, oldh)
+			oldh = core.GetHeader(es.backend.ChainDb(), oldh.ParentHash, oldh.Number.Uint64()-1)
+		}
+		if oldh.GetNumberU64() < newh.GetNumberU64() {
+			newHeaders = append(newHeaders, newh)
+			newh = core.GetHeader(es.backend.ChainDb(), newh.ParentHash, newh.Number.Uint64()-1)
+			if newh == nil {
+				// happens when CHT syncing, nothing to do
+				newh = oldh
+			}
+		}
+	}
+	// roll back old blocks
+	for _, h := range oldHeaders {
+		callBack(h, true)
+	}
+	// check new blocks (array is in reverse order)
+	for i := len(newHeaders) - 1; i >= 0; i-- {
+		callBack(newHeaders[i], false)
+	}
+}
+
+// filter logs of a single header in light client mode
+func (es *EventSystem) lightFilterLogs(header *types.Header, addresses []common.Address, topics [][]common.Hash, remove bool) []Log {
+	//fmt.Println("lightFilterLogs", header.Number.Uint64(), remove)
+	if bloomFilter(header.Bloom, addresses, topics) {
+		//fmt.Println("bloom match")
+		// Get the logs of the block
+		ctx, _ := context.WithTimeout(context.Background(), time.Second*5)
+		receipts, err := es.backend.GetReceipts(ctx, header.Hash())
+		if err != nil {
+			return nil
+		}
+		var unfiltered []Log
+		for _, receipt := range receipts {
+			rl := make([]Log, len(receipt.Logs))
+			for i, l := range receipt.Logs {
+				rl[i] = Log{l, remove}
+			}
+			unfiltered = append(unfiltered, rl...)
+		}
+		logs := filterLogs(unfiltered, addresses, topics)
+		//fmt.Println("found", len(logs))
+		return logs
 	}
+	return nil
 }
 
 // eventLoop (un)installs filters and processes mux events.
@@ -294,7 +370,7 @@ func (es *EventSystem) eventLoop() {
 			if !active { // system stopped
 				return
 			}
-			broadcast(index, ev)
+			es.broadcast(index, ev)
 		case f := <-es.install:
 			if _, found := index[f.typ]; !found {
 				index[f.typ] = make(map[rpc.ID]*subscription)

eth/filters/filter_system_test.go

@@ -32,9 +32,10 @@ import (
 )
 
 var (
-	mux   = new(event.TypeMux)
-	db, _ = ethdb.NewMemDatabase()
-	api   = NewPublicFilterAPI(db, mux)
+	mux     = new(event.TypeMux)
+	db, _   = ethdb.NewMemDatabase()
+	backend = &testBackend{mux, db}
+	api     = NewPublicFilterAPI(backend, false)
 )
 
 // TestBlockSubscription tests if a block subscription returns block hashes for posted chain events.

eth/gasprice/lightprice.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package gasprice
+
+import (
+	"math/big"
+	"sort"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/rpc"
+	"golang.org/x/net/context"
+)
+
+const (
+	LpoAvgCount     = 5
+	LpoMinCount     = 3
+	LpoMaxBlocks    = 20
+	LpoSelect       = 50
+	LpoDefaultPrice = 20000000000
+)
+
+// LightPriceOracle recommends gas prices based on the content of recent
+// blocks. Suitable for both light and full clients.
+type LightPriceOracle struct {
+	backend   ethapi.Backend
+	lastHead  common.Hash
+	lastPrice *big.Int
+	cacheLock sync.RWMutex
+	fetchLock sync.Mutex
+}
+
+// NewLightPriceOracle returns a new oracle.
+func NewLightPriceOracle(backend ethapi.Backend) *LightPriceOracle {
+	return &LightPriceOracle{
+		backend:   backend,
+		lastPrice: big.NewInt(LpoDefaultPrice),
+	}
+}
+
+// SuggestPrice returns the recommended gas price.
+func (self *LightPriceOracle) SuggestPrice(ctx context.Context) (*big.Int, error) {
+	self.cacheLock.RLock()
+	lastHead := self.lastHead
+	lastPrice := self.lastPrice
+	self.cacheLock.RUnlock()
+
+	head, _ := self.backend.HeaderByNumber(ctx, rpc.LatestBlockNumber)
+	headHash := head.Hash()
+	if headHash == lastHead {
+		return lastPrice, nil
+	}
+
+	self.fetchLock.Lock()
+	defer self.fetchLock.Unlock()
+
+	// try checking the cache again, maybe the last fetch fetched what we need
+	self.cacheLock.RLock()
+	lastHead = self.lastHead
+	lastPrice = self.lastPrice
+	self.cacheLock.RUnlock()
+	if headHash == lastHead {
+		return lastPrice, nil
+	}
+
+	blockNum := head.GetNumberU64()
+	chn := make(chan lpResult, LpoMaxBlocks)
+	sent := 0
+	exp := 0
+	var lps bigIntArray
+	for sent < LpoAvgCount && blockNum > 0 {
+		go self.getLowestPrice(ctx, blockNum, chn)
+		sent++
+		exp++
+		blockNum--
+	}
+	maxEmpty := LpoAvgCount - LpoMinCount
+	for exp > 0 {
+		res := <-chn
+		if res.err != nil {
+			return nil, res.err
+		}
+		exp--
+		if res.price != nil {
+			lps = append(lps, res.price)
+		} else {
+			if maxEmpty > 0 {
+				maxEmpty--
+			} else {
+				if blockNum > 0 && sent < LpoMaxBlocks {
+					go self.getLowestPrice(ctx, blockNum, chn)
+					sent++
+					exp++
+					blockNum--
+				}
+			}
+		}
+	}
+	price := lastPrice
+	if len(lps) > 0 {
+		sort.Sort(lps)
+		price = lps[(len(lps)-1)*LpoSelect/100]
+	}
+
+	self.cacheLock.Lock()
+	self.lastHead = headHash
+	self.lastPrice = price
+	self.cacheLock.Unlock()
+	return price, nil
+}
+
+type lpResult struct {
+	price *big.Int
+	err   error
+}
+
+// getLowestPrice calculates the lowest transaction gas price in a given block
+// and sends it to the result channel. If the block is empty, price is nil.
+func (self *LightPriceOracle) getLowestPrice(ctx context.Context, blockNum uint64, chn chan lpResult) {
+	block, err := self.backend.BlockByNumber(ctx, rpc.BlockNumber(blockNum))
+	if block == nil {
+		chn <- lpResult{nil, err}
+		return
+	}
+	txs := block.Transactions()
+	if len(txs) == 0 {
+		chn <- lpResult{nil, nil}
+		return
+	}
+	// find smallest gasPrice
+	minPrice := txs[0].GasPrice()
+	for i := 1; i < len(txs); i++ {
+		price := txs[i].GasPrice()
+		if price.Cmp(minPrice) < 0 {
+			minPrice = price
+		}
+	}
+	chn <- lpResult{minPrice, nil}
+}
+
+type bigIntArray []*big.Int
+
+func (s bigIntArray) Len() int           { return len(s) }
+func (s bigIntArray) Less(i, j int) bool { return s[i].Cmp(s[j]) < 0 }
+func (s bigIntArray) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }

internal/ethapi/api.go

@@ -366,14 +366,15 @@ func NewPublicBlockChainAPI(b Backend) *PublicBlockChainAPI {
 
 // BlockNumber returns the block number of the chain head.
 func (s *PublicBlockChainAPI) BlockNumber() *big.Int {
-	return s.b.HeaderByNumber(rpc.LatestBlockNumber).Number
+	header, _ := s.b.HeaderByNumber(context.Background(), rpc.LatestBlockNumber) // latest header should always be available
+	return header.Number
 }
 
 // GetBalance returns the amount of wei for the given address in the state of the
 // given block number. The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta
 // block numbers are also allowed.
 func (s *PublicBlockChainAPI) GetBalance(ctx context.Context, address common.Address, blockNr rpc.BlockNumber) (*big.Int, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return nil, err
 	}
@@ -458,7 +459,7 @@ func (s *PublicBlockChainAPI) GetUncleCountByBlockHash(ctx context.Context, bloc
 
 // GetCode returns the code stored at the given address in the state for the given block number.
 func (s *PublicBlockChainAPI) GetCode(ctx context.Context, address common.Address, blockNr rpc.BlockNumber) (string, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return "", err
 	}
@@ -473,7 +474,7 @@ func (s *PublicBlockChainAPI) GetCode(ctx context.Context, address common.Addres
 // block number. The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta block
 // numbers are also allowed.
 func (s *PublicBlockChainAPI) GetStorageAt(ctx context.Context, address common.Address, key string, blockNr rpc.BlockNumber) (string, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return "0x", err
 	}
@@ -517,7 +518,7 @@ type CallArgs struct {
 func (s *PublicBlockChainAPI) doCall(ctx context.Context, args CallArgs, blockNr rpc.BlockNumber) (string, *big.Int, error) {
 	defer func(start time.Time) { glog.V(logger.Debug).Infof("call took %v", time.Since(start)) }(time.Now())
 
-	state, header, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, header, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return "0x", common.Big0, err
 	}
@@ -859,7 +860,7 @@ func (s *PublicTransactionPoolAPI) GetRawTransactionByBlockHashAndIndex(ctx cont
 
 // GetTransactionCount returns the number of transactions the given address has sent for the given block number
 func (s *PublicTransactionPoolAPI) GetTransactionCount(ctx context.Context, address common.Address, blockNr rpc.BlockNumber) (*rpc.HexNumber, error) {
-	state, _, err := s.b.StateAndHeaderByNumber(blockNr)
+	state, _, err := s.b.StateAndHeaderByNumber(ctx, blockNr)
 	if state == nil || err != nil {
 		return nil, err
 	}

internal/ethapi/backend.go

@@ -44,9 +44,9 @@ type Backend interface {
 	AccountManager() *accounts.Manager
 	// BlockChain API
 	SetHead(number uint64)
-	HeaderByNumber(blockNr rpc.BlockNumber) *types.Header
+	HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error)
 	BlockByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Block, error)
-	StateAndHeaderByNumber(blockNr rpc.BlockNumber) (State, *types.Header, error)
+	StateAndHeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (State, *types.Header, error)
 	GetBlock(ctx context.Context, blockHash common.Hash) (*types.Block, error)
 	GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error)
 	GetTd(blockHash common.Hash) *big.Int

les/api_backend.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package les
+
+import (
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/eth/gasprice"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/light"
+	rpc "github.com/ethereum/go-ethereum/rpc"
+	"golang.org/x/net/context"
+)
+
+type LesApiBackend struct {
+	eth *LightEthereum
+	gpo *gasprice.LightPriceOracle
+}
+
+func (b *LesApiBackend) SetHead(number uint64) {
+	b.eth.blockchain.SetHead(number)
+}
+
+func (b *LesApiBackend) HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error) {
+	if blockNr == rpc.LatestBlockNumber || blockNr == rpc.PendingBlockNumber {
+		return b.eth.blockchain.CurrentHeader(), nil
+	}
+
+	return b.eth.blockchain.GetHeaderByNumberOdr(ctx, uint64(blockNr))
+}
+
+func (b *LesApiBackend) BlockByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Block, error) {
+	header, err := b.HeaderByNumber(ctx, blockNr)
+	if header == nil || err != nil {
+		return nil, err
+	}
+	return b.GetBlock(ctx, header.Hash())
+}
+
+func (b *LesApiBackend) StateAndHeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (ethapi.State, *types.Header, error) {
+	header, err := b.HeaderByNumber(ctx, blockNr)
+	if header == nil || err != nil {
+		return nil, nil, err
+	}
+	return light.NewLightState(light.StateTrieID(header), b.eth.odr), header, nil
+}
+
+func (b *LesApiBackend) GetBlock(ctx context.Context, blockHash common.Hash) (*types.Block, error) {
+	return b.eth.blockchain.GetBlockByHash(ctx, blockHash)
+}
+
+func (b *LesApiBackend) GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error) {
+	return light.GetBlockReceipts(ctx, b.eth.odr, blockHash, core.GetBlockNumber(b.eth.chainDb, blockHash))
+}
+
+func (b *LesApiBackend) GetTd(blockHash common.Hash) *big.Int {
+	return b.eth.blockchain.GetTdByHash(blockHash)
+}
+
+func (b *LesApiBackend) GetVMEnv(ctx context.Context, msg core.Message, state ethapi.State, header *types.Header) (vm.Environment, func() error, error) {
+	stateDb := state.(*light.LightState).Copy()
+	addr, _ := msg.From()
+	from, err := stateDb.GetOrNewStateObject(ctx, addr)
+	if err != nil {
+		return nil, nil, err
+	}
+	from.SetBalance(common.MaxBig)
+	env := light.NewEnv(ctx, stateDb, b.eth.chainConfig, b.eth.blockchain, msg, header, b.eth.chainConfig.VmConfig)
+	return env, env.Error, nil
+}
+
+func (b *LesApiBackend) SendTx(ctx context.Context, signedTx *types.Transaction) error {
+	return b.eth.txPool.Add(ctx, signedTx)
+}
+
+func (b *LesApiBackend) RemoveTx(txHash common.Hash) {
+	b.eth.txPool.RemoveTx(txHash)
+}
+
+func (b *LesApiBackend) GetPoolTransactions() types.Transactions {
+	return b.eth.txPool.GetTransactions()
+}
+
+func (b *LesApiBackend) GetPoolTransaction(txHash common.Hash) *types.Transaction {
+	return b.eth.txPool.GetTransaction(txHash)
+}
+
+func (b *LesApiBackend) GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error) {
+	return b.eth.txPool.GetNonce(ctx, addr)
+}
+
+func (b *LesApiBackend) Stats() (pending int, queued int) {
+	return b.eth.txPool.Stats(), 0
+}
+
+func (b *LesApiBackend) TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions) {
+	return b.eth.txPool.Content()
+}
+
+func (b *LesApiBackend) Downloader() *downloader.Downloader {
+	return b.eth.Downloader()
+}
+
+func (b *LesApiBackend) ProtocolVersion() int {
+	return b.eth.LesVersion() + 10000
+}
+
+func (b *LesApiBackend) SuggestPrice(ctx context.Context) (*big.Int, error) {
+	return b.gpo.SuggestPrice(ctx)
+}
+
+func (b *LesApiBackend) ChainDb() ethdb.Database {
+	return b.eth.chainDb
+}
+
+func (b *LesApiBackend) EventMux() *event.TypeMux {
+	return b.eth.eventMux
+}
+
+func (b *LesApiBackend) AccountManager() *accounts.Manager {
+	return b.eth.accountManager
+}

les/backend.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package les implements the Light Ethereum Subprotocol.
+package les
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/ethereum/ethash"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/compiler"
+	"github.com/ethereum/go-ethereum/common/httpclient"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/eth/filters"
+	"github.com/ethereum/go-ethereum/eth/gasprice"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/light"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	rpc "github.com/ethereum/go-ethereum/rpc"
+)
+
+type LightEthereum struct {
+	odr         *LesOdr
+	relay       *LesTxRelay
+	chainConfig *core.ChainConfig
+	// Channel for shutting down the service
+	shutdownChan chan bool
+	// Handlers
+	txPool          *light.TxPool
+	blockchain      *light.LightChain
+	protocolManager *ProtocolManager
+	// DB interfaces
+	chainDb ethdb.Database // Block chain database
+
+	ApiBackend *LesApiBackend
+
+	eventMux       *event.TypeMux
+	pow            *ethash.Ethash
+	httpclient     *httpclient.HTTPClient
+	accountManager *accounts.Manager
+	solcPath       string
+	solc           *compiler.Solidity
+
+	NatSpec       bool
+	PowTest       bool
+	netVersionId  int
+	netRPCService *ethapi.PublicNetAPI
+}
+
+func New(ctx *node.ServiceContext, config *eth.Config) (*LightEthereum, error) {
+	chainDb, err := eth.CreateDB(ctx, config, "lightchaindata")
+	if err != nil {
+		return nil, err
+	}
+	if err := eth.SetupGenesisBlock(&chainDb, config); err != nil {
+		return nil, err
+	}
+	pow, err := eth.CreatePoW(config)
+	if err != nil {
+		return nil, err
+	}
+
+	odr := NewLesOdr(chainDb)
+	relay := NewLesTxRelay()
+	eth := &LightEthereum{
+		odr:            odr,
+		relay:          relay,
+		chainDb:        chainDb,
+		eventMux:       ctx.EventMux,
+		accountManager: ctx.AccountManager,
+		pow:            pow,
+		shutdownChan:   make(chan bool),
+		httpclient:     httpclient.New(config.DocRoot),
+		netVersionId:   config.NetworkId,
+		NatSpec:        config.NatSpec,
+		PowTest:        config.PowTest,
+		solcPath:       config.SolcPath,
+	}
+
+	if config.ChainConfig == nil {
+		return nil, errors.New("missing chain config")
+	}
+	eth.chainConfig = config.ChainConfig
+	eth.chainConfig.VmConfig = vm.Config{
+		EnableJit: config.EnableJit,
+		ForceJit:  config.ForceJit,
+	}
+	eth.blockchain, err = light.NewLightChain(odr, eth.chainConfig, eth.pow, eth.eventMux)
+	if err != nil {
+		if err == core.ErrNoGenesis {
+			return nil, fmt.Errorf(`Genesis block not found. Please supply a genesis block with the "--genesis /path/to/file" argument`)
+		}
+		return nil, err
+	}
+
+	eth.txPool = light.NewTxPool(eth.chainConfig, eth.eventMux, eth.blockchain, eth.relay)
+	if eth.protocolManager, err = NewProtocolManager(eth.chainConfig, config.LightMode, config.NetworkId, eth.eventMux, eth.pow, eth.blockchain, nil, chainDb, odr, relay); err != nil {
+		return nil, err
+	}
+
+	eth.ApiBackend = &LesApiBackend{eth, nil}
+	eth.ApiBackend.gpo = gasprice.NewLightPriceOracle(eth.ApiBackend)
+	return eth, nil
+}
+
+type LightDummyAPI struct{}
+
+// Etherbase is the address that mining rewards will be send to
+func (s *LightDummyAPI) Etherbase() (common.Address, error) {
+	return common.Address{}, fmt.Errorf("not supported")
+}
+
+// Coinbase is the address that mining rewards will be send to (alias for Etherbase)
+func (s *LightDummyAPI) Coinbase() (common.Address, error) {
+	return common.Address{}, fmt.Errorf("not supported")
+}
+
+// Hashrate returns the POW hashrate
+func (s *LightDummyAPI) Hashrate() *rpc.HexNumber {
+	return rpc.NewHexNumber(0)
+}
+
+// Mining returns an indication if this node is currently mining.
+func (s *LightDummyAPI) Mining() bool {
+	return false
+}
+
+// APIs returns the collection of RPC services the ethereum package offers.
+// NOTE, some of these services probably need to be moved to somewhere else.
+func (s *LightEthereum) APIs() []rpc.API {
+	return append(ethapi.GetAPIs(s.ApiBackend, s.solcPath), []rpc.API{
+		{
+			Namespace: "eth",
+			Version:   "1.0",
+			Service:   &LightDummyAPI{},
+			Public:    true,
+		}, {
+			Namespace: "eth",
+			Version:   "1.0",
+			Service:   downloader.NewPublicDownloaderAPI(s.protocolManager.downloader, s.eventMux),
+			Public:    true,
+		}, {
+			Namespace: "eth",
+			Version:   "1.0",
+			Service:   filters.NewPublicFilterAPI(s.ApiBackend, true),
+			Public:    true,
+		}, {
+			Namespace: "net",
+			Version:   "1.0",
+			Service:   s.netRPCService,
+			Public:    true,
+		},
+	}...)
+}
+
+func (s *LightEthereum) ResetWithGenesisBlock(gb *types.Block) {
+	s.blockchain.ResetWithGenesisBlock(gb)
+}
+
+func (s *LightEthereum) BlockChain() *light.LightChain      { return s.blockchain }
+func (s *LightEthereum) TxPool() *light.TxPool              { return s.txPool }
+func (s *LightEthereum) LesVersion() int                    { return int(s.protocolManager.SubProtocols[0].Version) }
+func (s *LightEthereum) Downloader() *downloader.Downloader { return s.protocolManager.downloader }
+
+// Protocols implements node.Service, returning all the currently configured
+// network protocols to start.
+func (s *LightEthereum) Protocols() []p2p.Protocol {
+	return s.protocolManager.SubProtocols
+}
+
+// Start implements node.Service, starting all internal goroutines needed by the
+// Ethereum protocol implementation.
+func (s *LightEthereum) Start(srvr *p2p.Server) error {
+	s.netRPCService = ethapi.NewPublicNetAPI(srvr, s.netVersionId)
+	s.protocolManager.Start()
+	return nil
+}
+
+// Stop implements node.Service, terminating all internal goroutines used by the
+// Ethereum protocol.
+func (s *LightEthereum) Stop() error {
+	s.odr.Stop()
+	s.blockchain.Stop()
+	s.protocolManager.Stop()
+	s.txPool.Stop()
+
+	s.eventMux.Stop()
+
+	time.Sleep(time.Millisecond * 200)
+	s.chainDb.Close()
+	close(s.shutdownChan)
+
+	return nil
+}

les/fetcher.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package les implements the Light Ethereum Subprotocol.
+package les
+
+import (
+	"math/big"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+type lightFetcher struct {
+	pm    *ProtocolManager
+	odr   *LesOdr
+	chain BlockChain
+
+	headAnnouncedMu sync.Mutex
+	headAnnouncedBy map[common.Hash][]*peer
+	currentTd       *big.Int
+	deliverChn      chan fetchResponse
+	reqMu           sync.RWMutex
+	requested       map[uint64]fetchRequest
+	timeoutChn      chan uint64
+	notifyChn       chan bool // true if initiated from outside
+	syncing         bool
+	syncDone        chan struct{}
+}
+
+type fetchRequest struct {
+	hash   common.Hash
+	amount uint64
+	peer   *peer
+}
+
+type fetchResponse struct {
+	reqID   uint64
+	headers []*types.Header
+}
+
+func newLightFetcher(pm *ProtocolManager) *lightFetcher {
+	f := &lightFetcher{
+		pm:              pm,
+		chain:           pm.blockchain,
+		odr:             pm.odr,
+		headAnnouncedBy: make(map[common.Hash][]*peer),
+		deliverChn:      make(chan fetchResponse, 100),
+		requested:       make(map[uint64]fetchRequest),
+		timeoutChn:      make(chan uint64),
+		notifyChn:       make(chan bool, 100),
+		syncDone:        make(chan struct{}),
+		currentTd:       big.NewInt(0),
+	}
+	go f.syncLoop()
+	return f
+}
+
+func (f *lightFetcher) notify(p *peer, head *announceData) {
+	var headHash common.Hash
+	if head == nil {
+		// initial notify
+		headHash = p.Head()
+	} else {
+		if core.GetTd(f.pm.chainDb, head.Hash, head.Number) != nil {
+			head.haveHeaders = head.Number
+		}
+		//fmt.Println("notify", p.id, head.Number, head.ReorgDepth, head.haveHeaders)
+		if !p.addNotify(head) {
+			//fmt.Println("addNotify fail")
+			f.pm.removePeer(p.id)
+		}
+		headHash = head.Hash
+	}
+	f.headAnnouncedMu.Lock()
+	f.headAnnouncedBy[headHash] = append(f.headAnnouncedBy[headHash], p)
+	f.headAnnouncedMu.Unlock()
+	f.notifyChn <- true
+}
+
+func (f *lightFetcher) gotHeader(header *types.Header) {
+	f.headAnnouncedMu.Lock()
+	defer f.headAnnouncedMu.Unlock()
+
+	hash := header.Hash()
+	peerList := f.headAnnouncedBy[hash]
+	if peerList == nil {
+		return
+	}
+	number := header.GetNumberU64()
+	td := core.GetTd(f.pm.chainDb, hash, number)
+	for _, peer := range peerList {
+		peer.lock.Lock()
+		ok := peer.gotHeader(hash, number, td)
+		peer.lock.Unlock()
+		if !ok {
+			//fmt.Println("gotHeader fail")
+			f.pm.removePeer(peer.id)
+		}
+	}
+	delete(f.headAnnouncedBy, hash)
+}
+
+func (f *lightFetcher) nextRequest() (*peer, *announceData) {
+	var bestPeer *peer
+	bestTd := f.currentTd
+	for _, peer := range f.pm.peers.AllPeers() {
+		peer.lock.RLock()
+		if !peer.headInfo.requested && (peer.headInfo.Td.Cmp(bestTd) > 0 ||
+			(bestPeer != nil && peer.headInfo.Td.Cmp(bestTd) == 0 && peer.headInfo.haveHeaders > bestPeer.headInfo.haveHeaders)) {
+			bestPeer = peer
+			bestTd = peer.headInfo.Td
+		}
+		peer.lock.RUnlock()
+	}
+	if bestPeer == nil {
+		return nil, nil
+	}
+	bestPeer.lock.Lock()
+	res := bestPeer.headInfo
+	res.requested = true
+	bestPeer.lock.Unlock()
+	for _, peer := range f.pm.peers.AllPeers() {
+		if peer != bestPeer {
+			peer.lock.Lock()
+			if peer.headInfo.Hash == bestPeer.headInfo.Hash && peer.headInfo.haveHeaders == bestPeer.headInfo.haveHeaders {
+				peer.headInfo.requested = true
+			}
+			peer.lock.Unlock()
+		}
+	}
+	return bestPeer, res
+}
+
+func (f *lightFetcher) deliverHeaders(reqID uint64, headers []*types.Header) {
+	f.deliverChn <- fetchResponse{reqID: reqID, headers: headers}
+}
+
+func (f *lightFetcher) requestedID(reqID uint64) bool {
+	f.reqMu.RLock()
+	_, ok := f.requested[reqID]
+	f.reqMu.RUnlock()
+	return ok
+}
+
+func (f *lightFetcher) request(p *peer, block *announceData) {
+	//fmt.Println("request", p.id, block.Number, block.haveHeaders)
+	amount := block.Number - block.haveHeaders
+	if amount == 0 {
+		return
+	}
+	if amount > 100 {
+		f.syncing = true
+		go func() {
+			//fmt.Println("f.pm.synchronise(p)")
+			f.pm.synchronise(p)
+			//fmt.Println("sync done")
+			f.syncDone <- struct{}{}
+		}()
+		return
+	}
+
+	reqID := f.odr.getNextReqID()
+	f.reqMu.Lock()
+	f.requested[reqID] = fetchRequest{hash: block.Hash, amount: amount, peer: p}
+	f.reqMu.Unlock()
+	cost := p.GetRequestCost(GetBlockHeadersMsg, int(amount))
+	p.fcServer.SendRequest(reqID, cost)
+	go p.RequestHeadersByHash(reqID, cost, block.Hash, int(amount), 0, true)
+	go func() {
+		time.Sleep(hardRequestTimeout)
+		f.timeoutChn <- reqID
+	}()
+}
+
+func (f *lightFetcher) processResponse(req fetchRequest, resp fetchResponse) bool {
+	if uint64(len(resp.headers)) != req.amount || resp.headers[0].Hash() != req.hash {
+		return false
+	}
+	headers := make([]*types.Header, req.amount)
+	for i, header := range resp.headers {
+		headers[int(req.amount)-1-i] = header
+	}
+	if _, err := f.chain.InsertHeaderChain(headers, 1); err != nil {
+		return false
+	}
+	for _, header := range headers {
+		td := core.GetTd(f.pm.chainDb, header.Hash(), header.GetNumberU64())
+		if td == nil {
+			return false
+		}
+		if td.Cmp(f.currentTd) > 0 {
+			f.currentTd = td
+		}
+		f.gotHeader(header)
+	}
+	return true
+}
+
+func (f *lightFetcher) checkSyncedHeaders() {
+	//fmt.Println("checkSyncedHeaders()")
+	for _, peer := range f.pm.peers.AllPeers() {
+		peer.lock.Lock()
+		h := peer.firstHeadInfo
+		remove := false
+	loop:
+		for h != nil {
+			if td := core.GetTd(f.pm.chainDb, h.Hash, h.Number); td != nil {
+				//fmt.Println(" found", h.Number)
+				ok := peer.gotHeader(h.Hash, h.Number, td)
+				if !ok {
+					remove = true
+					break loop
+				}
+				if td.Cmp(f.currentTd) > 0 {
+					f.currentTd = td
+				}
+			}
+			h = h.next
+		}
+		peer.lock.Unlock()
+		if remove {
+			//fmt.Println("checkSync fail")
+			f.pm.removePeer(peer.id)
+		}
+	}
+}
+
+func (f *lightFetcher) syncLoop() {
+	f.pm.wg.Add(1)
+	defer f.pm.wg.Done()
+
+	srtoNotify := false
+	for {
+		select {
+		case <-f.pm.quitSync:
+			return
+		case ext := <-f.notifyChn:
+			//fmt.Println("<-f.notifyChn", f.syncing, ext, srtoNotify)
+			s := srtoNotify
+			srtoNotify = false
+			if !f.syncing && !(ext && s) {
+				if p, r := f.nextRequest(); r != nil {
+					srtoNotify = true
+					go func() {
+						time.Sleep(softRequestTimeout)
+						f.notifyChn <- false
+					}()
+					f.request(p, r)
+				}
+			}
+		case reqID := <-f.timeoutChn:
+			f.reqMu.Lock()
+			req, ok := f.requested[reqID]
+			if ok {
+				delete(f.requested, reqID)
+			}
+			f.reqMu.Unlock()
+			if ok {
+				//fmt.Println("hard timeout")
+				f.pm.removePeer(req.peer.id)
+			}
+		case resp := <-f.deliverChn:
+			//fmt.Println("<-f.deliverChn", f.syncing)
+			f.reqMu.Lock()
+			req, ok := f.requested[resp.reqID]
+			delete(f.requested, resp.reqID)
+			f.reqMu.Unlock()
+			if !ok || !(f.syncing || f.processResponse(req, resp)) {
+				//fmt.Println("processResponse fail")
+				f.pm.removePeer(req.peer.id)
+			}
+		case <-f.syncDone:
+			//fmt.Println("<-f.syncDone", f.syncing)
+			f.checkSyncedHeaders()
+			f.syncing = false
+		}
+	}
+}

les/flowcontrol/control.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package flowcontrol implements a client side flow control mechanism
+package flowcontrol
+
+import (
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common/mclock"
+)
+
+const fcTimeConst = 1000000
+
+type ServerParams struct {
+	BufLimit, MinRecharge uint64
+}
+
+type ClientNode struct {
+	params   *ServerParams
+	bufValue uint64
+	lastTime int64
+	lock     sync.Mutex
+	cm       *ClientManager
+	cmNode   *cmNode
+}
+
+func NewClientNode(cm *ClientManager, params *ServerParams) *ClientNode {
+	node := &ClientNode{
+		cm:       cm,
+		params:   params,
+		bufValue: params.BufLimit,
+		lastTime: getTime(),
+	}
+	node.cmNode = cm.addNode(node)
+	return node
+}
+
+func (peer *ClientNode) Remove(cm *ClientManager) {
+	cm.removeNode(peer.cmNode)
+}
+
+func (peer *ClientNode) recalcBV(time int64) {
+	dt := uint64(time - peer.lastTime)
+	if time < peer.lastTime {
+		dt = 0
+	}
+	peer.bufValue += peer.params.MinRecharge * dt / fcTimeConst
+	if peer.bufValue > peer.params.BufLimit {
+		peer.bufValue = peer.params.BufLimit
+	}
+	peer.lastTime = time
+}
+
+func (peer *ClientNode) AcceptRequest() (uint64, bool) {
+	peer.lock.Lock()
+	defer peer.lock.Unlock()
+
+	time := getTime()
+	peer.recalcBV(time)
+	return peer.bufValue, peer.cm.accept(peer.cmNode, time)
+}
+
+func (peer *ClientNode) RequestProcessed(cost uint64) (bv, realCost uint64) {
+	peer.lock.Lock()
+	defer peer.lock.Unlock()
+
+	time := getTime()
+	peer.recalcBV(time)
+	peer.bufValue -= cost
+	peer.recalcBV(time)
+	rcValue, rcost := peer.cm.processed(peer.cmNode, time)
+	if rcValue < peer.params.BufLimit {
+		bv := peer.params.BufLimit - rcValue
+		if bv > peer.bufValue {
+			peer.bufValue = bv
+		}
+	}
+	return peer.bufValue, rcost
+}
+
+type ServerNode struct {
+	bufEstimate uint64
+	lastTime    int64
+	params      *ServerParams
+	sumCost     uint64            // sum of req costs sent to this server
+	pending     map[uint64]uint64 // value = sumCost after sending the given req
+	lock        sync.Mutex
+}
+
+func NewServerNode(params *ServerParams) *ServerNode {
+	return &ServerNode{
+		bufEstimate: params.BufLimit,
+		lastTime:    getTime(),
+		params:      params,
+		pending:     make(map[uint64]uint64),
+	}
+}
+
+func getTime() int64 {
+	return int64(mclock.Now())
+}
+
+func (peer *ServerNode) recalcBLE(time int64) {
+	dt := uint64(time - peer.lastTime)
+	if time < peer.lastTime {
+		dt = 0
+	}
+	peer.bufEstimate += peer.params.MinRecharge * dt / fcTimeConst
+	if peer.bufEstimate > peer.params.BufLimit {
+		peer.bufEstimate = peer.params.BufLimit
+	}
+	peer.lastTime = time
+}
+
+func (peer *ServerNode) canSend(maxCost uint64) uint64 {
+	if peer.bufEstimate >= maxCost {
+		return 0
+	}
+	return (maxCost - peer.bufEstimate) * fcTimeConst / peer.params.MinRecharge
+}
+
+func (peer *ServerNode) CanSend(maxCost uint64) uint64 {
+	peer.lock.Lock()
+	defer peer.lock.Unlock()
+
+	return peer.canSend(maxCost)
+}
+
+// blocks until request can be sent
+func (peer *ServerNode) SendRequest(reqID, maxCost uint64) {
+	peer.lock.Lock()
+	defer peer.lock.Unlock()
+
+	peer.recalcBLE(getTime())
+	for peer.bufEstimate < maxCost {
+		time.Sleep(time.Duration(peer.canSend(maxCost)))
+		peer.recalcBLE(getTime())
+	}
+	peer.bufEstimate -= maxCost
+	peer.sumCost += maxCost
+	if reqID >= 0 {
+		peer.pending[reqID] = peer.sumCost
+	}
+}
+
+func (peer *ServerNode) GotReply(reqID, bv uint64) {
+	peer.lock.Lock()
+	defer peer.lock.Unlock()
+
+	sc, ok := peer.pending[reqID]
+	if !ok {
+		return
+	}
+	delete(peer.pending, reqID)
+	peer.bufEstimate = bv - (peer.sumCost - sc)
+	peer.lastTime = getTime()
+}

les/flowcontrol/manager.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package flowcontrol implements a client side flow control mechanism
+package flowcontrol
+
+import (
+	"sync"
+	"time"
+)
+
+const rcConst = 1000000
+
+type cmNode struct {
+	node                       *ClientNode
+	lastUpdate                 int64
+	reqAccepted                int64
+	serving, recharging        bool
+	rcWeight                   uint64
+	rcValue, rcDelta           int64
+	finishRecharge, startValue int64
+}
+
+func (node *cmNode) update(time int64) {
+	dt := time - node.lastUpdate
+	node.rcValue += node.rcDelta * dt / rcConst
+	node.lastUpdate = time
+	if node.recharging && time >= node.finishRecharge {
+		node.recharging = false
+		node.rcDelta = 0
+		node.rcValue = 0
+	}
+}
+
+func (node *cmNode) set(serving bool, simReqCnt, sumWeight uint64) {
+	if node.serving && !serving {
+		node.recharging = true
+		sumWeight += node.rcWeight
+	}
+	node.serving = serving
+	if node.recharging && serving {
+		node.recharging = false
+		sumWeight -= node.rcWeight
+	}
+
+	node.rcDelta = 0
+	if serving {
+		node.rcDelta = int64(rcConst / simReqCnt)
+	}
+	if node.recharging {
+		node.rcDelta = -int64(node.node.cm.rcRecharge * node.rcWeight / sumWeight)
+		node.finishRecharge = node.lastUpdate + node.rcValue*rcConst/(-node.rcDelta)
+	}
+}
+
+type ClientManager struct {
+	lock                             sync.Mutex
+	nodes                            map[*cmNode]struct{}
+	simReqCnt, sumWeight, rcSumValue uint64
+	maxSimReq, maxRcSum              uint64
+	rcRecharge                       uint64
+	resumeQueue                      chan chan bool
+	time                             int64
+}
+
+func NewClientManager(rcTarget, maxSimReq, maxRcSum uint64) *ClientManager {
+	cm := &ClientManager{
+		nodes:       make(map[*cmNode]struct{}),
+		resumeQueue: make(chan chan bool),
+		rcRecharge:  rcConst * rcConst / (100*rcConst/rcTarget - rcConst),
+		maxSimReq:   maxSimReq,
+		maxRcSum:    maxRcSum,
+	}
+	go cm.queueProc()
+	return cm
+}
+
+func (self *ClientManager) Stop() {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	// signal any waiting accept routines to return false
+	self.nodes = make(map[*cmNode]struct{})
+	close(self.resumeQueue)
+}
+
+func (self *ClientManager) addNode(cnode *ClientNode) *cmNode {
+	time := getTime()
+	node := &cmNode{
+		node:           cnode,
+		lastUpdate:     time,
+		finishRecharge: time,
+		rcWeight:       1,
+	}
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	self.nodes[node] = struct{}{}
+	self.update(getTime())
+	return node
+}
+
+func (self *ClientManager) removeNode(node *cmNode) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	time := getTime()
+	self.stop(node, time)
+	delete(self.nodes, node)
+	self.update(time)
+}
+
+// recalc sumWeight
+func (self *ClientManager) updateNodes(time int64) (rce bool) {
+	var sumWeight, rcSum uint64
+	for node, _ := range self.nodes {
+		rc := node.recharging
+		node.update(time)
+		if rc && !node.recharging {
+			rce = true
+		}
+		if node.recharging {
+			sumWeight += node.rcWeight
+		}
+		rcSum += uint64(node.rcValue)
+	}
+	self.sumWeight = sumWeight
+	self.rcSumValue = rcSum
+	return
+}
+
+func (self *ClientManager) update(time int64) {
+	for {
+		firstTime := time
+		for node, _ := range self.nodes {
+			if node.recharging && node.finishRecharge < firstTime {
+				firstTime = node.finishRecharge
+			}
+		}
+		if self.updateNodes(firstTime) {
+			for node, _ := range self.nodes {
+				if node.recharging {
+					node.set(node.serving, self.simReqCnt, self.sumWeight)
+				}
+			}
+		} else {
+			self.time = time
+			return
+		}
+	}
+}
+
+func (self *ClientManager) canStartReq() bool {
+	return self.simReqCnt < self.maxSimReq && self.rcSumValue < self.maxRcSum
+}
+
+func (self *ClientManager) queueProc() {
+	for rc := range self.resumeQueue {
+		for {
+			time.Sleep(time.Millisecond * 10)
+			self.lock.Lock()
+			self.update(getTime())
+			cs := self.canStartReq()
+			self.lock.Unlock()
+			if cs {
+				break
+			}
+		}
+		close(rc)
+	}
+}
+
+func (self *ClientManager) accept(node *cmNode, time int64) bool {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	self.update(time)
+	if !self.canStartReq() {
+		resume := make(chan bool)
+		self.lock.Unlock()
+		self.resumeQueue <- resume
+		<-resume
+		self.lock.Lock()
+		if _, ok := self.nodes[node]; !ok {
+			return false // reject if node has been removed or manager has been stopped
+		}
+	}
+	self.simReqCnt++
+	node.set(true, self.simReqCnt, self.sumWeight)
+	node.startValue = node.rcValue
+	self.update(self.time)
+	return true
+}
+
+func (self *ClientManager) stop(node *cmNode, time int64) {
+	if node.serving {
+		self.update(time)
+		self.simReqCnt--
+		node.set(false, self.simReqCnt, self.sumWeight)
+		self.update(time)
+	}
+}
+
+func (self *ClientManager) processed(node *cmNode, time int64) (rcValue, rcCost uint64) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	self.stop(node, time)
+	return uint64(node.rcValue), uint64(node.rcValue - node.startValue)
+}

les/handler.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package les implements the Light Ethereum Subprotocol.
+package les
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/big"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/pow"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+const (
+	softResponseLimit = 2 * 1024 * 1024 // Target maximum size of returned blocks, headers or node data.
+	estHeaderRlpSize  = 500             // Approximate size of an RLP encoded block header
+
+	ethVersion = 63 // equivalent eth version for the downloader
+
+	MaxHeaderFetch       = 192 // Amount of block headers to be fetched per retrieval request
+	MaxBodyFetch         = 32  // Amount of block bodies to be fetched per retrieval request
+	MaxReceiptFetch      = 128 // Amount of transaction receipts to allow fetching per request
+	MaxCodeFetch         = 64  // Amount of contract codes to allow fetching per request
+	MaxProofsFetch       = 64  // Amount of merkle proofs to be fetched per retrieval request
+	MaxHeaderProofsFetch = 64  // Amount of merkle proofs to be fetched per retrieval request
+	MaxTxSend            = 64  // Amount of transactions to be send per request
+
+	disableClientRemovePeer = true
+)
+
+// errIncompatibleConfig is returned if the requested protocols and configs are
+// not compatible (low protocol version restrictions and high requirements).
+var errIncompatibleConfig = errors.New("incompatible configuration")
+
+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 BlockChain interface {
+	HasHeader(hash common.Hash) bool
+	GetHeader(hash common.Hash, number uint64) *types.Header
+	GetHeaderByHash(hash common.Hash) *types.Header
+	CurrentHeader() *types.Header
+	GetTdByHash(hash common.Hash) *big.Int
+	InsertHeaderChain(chain []*types.Header, checkFreq int) (int, error)
+	Rollback(chain []common.Hash)
+	Status() (td *big.Int, currentBlock common.Hash, genesisBlock common.Hash)
+	GetHeaderByNumber(number uint64) *types.Header
+	GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash
+	LastBlockHash() common.Hash
+	Genesis() *types.Block
+}
+
+type txPool interface {
+	// AddTransactions should add the given transactions to the pool.
+	AddBatch([]*types.Transaction)
+}
+
+type ProtocolManager struct {
+	lightSync   bool
+	txpool      txPool
+	txrelay     *LesTxRelay
+	networkId   int
+	chainConfig *core.ChainConfig
+	blockchain  BlockChain
+	chainDb     ethdb.Database
+	odr         *LesOdr
+	server      *LesServer
+
+	downloader *downloader.Downloader
+	fetcher    *lightFetcher
+	peers      *peerSet
+
+	SubProtocols []p2p.Protocol
+
+	eventMux *event.TypeMux
+
+	// channels for fetcher, syncer, txsyncLoop
+	newPeerCh   chan *peer
+	quitSync    chan struct{}
+	noMorePeers chan struct{}
+
+	syncMu   sync.Mutex
+	syncing  bool
+	syncDone chan struct{}
+
+	// wait group is used for graceful shutdowns during downloading
+	// and processing
+	wg sync.WaitGroup
+}
+
+// NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
+// with the ethereum network.
+func NewProtocolManager(chainConfig *core.ChainConfig, lightSync bool, networkId int, mux *event.TypeMux, pow pow.PoW, blockchain BlockChain, txpool txPool, chainDb ethdb.Database, odr *LesOdr, txrelay *LesTxRelay) (*ProtocolManager, error) {
+	// Create the protocol manager with the base fields
+	manager := &ProtocolManager{
+		lightSync:   lightSync,
+		eventMux:    mux,
+		blockchain:  blockchain,
+		chainConfig: chainConfig,
+		chainDb:     chainDb,
+		networkId:   networkId,
+		txpool:      txpool,
+		txrelay:     txrelay,
+		odr:         odr,
+		peers:       newPeerSet(),
+		newPeerCh:   make(chan *peer),
+		quitSync:    make(chan struct{}),
+		noMorePeers: make(chan struct{}),
+	}
+	// Initiate a sub-protocol for every implemented version we can handle
+	manager.SubProtocols = make([]p2p.Protocol, 0, len(ProtocolVersions))
+	for i, version := range ProtocolVersions {
+		// Compatible, initialize the sub-protocol
+		version := version // Closure for the run
+		manager.SubProtocols = append(manager.SubProtocols, p2p.Protocol{
+			Name:    "les",
+			Version: version,
+			Length:  ProtocolLengths[i],
+			Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
+				peer := manager.newPeer(int(version), networkId, p, rw)
+				select {
+				case manager.newPeerCh <- peer:
+					manager.wg.Add(1)
+					defer manager.wg.Done()
+					return manager.handle(peer)
+				case <-manager.quitSync:
+					return p2p.DiscQuitting
+				}
+			},
+			NodeInfo: func() interface{} {
+				return manager.NodeInfo()
+			},
+			PeerInfo: func(id discover.NodeID) interface{} {
+				if p := manager.peers.Peer(fmt.Sprintf("%x", id[:8])); p != nil {
+					return p.Info()
+				}
+				return nil
+			},
+		})
+	}
+	if len(manager.SubProtocols) == 0 {
+		return nil, errIncompatibleConfig
+	}
+
+	removePeer := manager.removePeer
+	if disableClientRemovePeer {
+		removePeer = func(id string) {}
+	}
+
+	if lightSync {
+		glog.V(logger.Debug).Infof("LES: create downloader")
+		manager.downloader = downloader.New(downloader.LightSync, chainDb, manager.eventMux, blockchain.HasHeader, nil, blockchain.GetHeaderByHash,
+			nil, blockchain.CurrentHeader, nil, nil, nil, blockchain.GetTdByHash,
+			blockchain.InsertHeaderChain, nil, nil, blockchain.Rollback, removePeer)
+		manager.fetcher = newLightFetcher(manager)
+	}
+
+	if odr != nil {
+		odr.removePeer = removePeer
+	}
+
+	/*validator := func(block *types.Block, parent *types.Block) error {
+		return core.ValidateHeader(pow, block.Header(), parent.Header(), true, false)
+	}
+	heighter := func() uint64 {
+		return chainman.LastBlockNumberU64()
+	}
+	manager.fetcher = fetcher.New(chainman.GetBlockNoOdr, validator, nil, heighter, chainman.InsertChain, manager.removePeer)
+	*/
+	return manager, nil
+}
+
+func (pm *ProtocolManager) removePeer(id string) {
+	// Short circuit if the peer was already removed
+	peer := pm.peers.Peer(id)
+	if peer == nil {
+		return
+	}
+	glog.V(logger.Debug).Infoln("Removing peer", id)
+
+	// Unregister the peer from the downloader and Ethereum peer set
+	glog.V(logger.Debug).Infof("LES: unregister peer %v", id)
+	if pm.lightSync {
+		pm.downloader.UnregisterPeer(id)
+		pm.odr.UnregisterPeer(peer)
+		if pm.txrelay != nil {
+			pm.txrelay.removePeer(id)
+		}
+	}
+	if err := pm.peers.Unregister(id); err != nil {
+		glog.V(logger.Error).Infoln("Removal failed:", err)
+	}
+	// Hard disconnect at the networking layer
+	if peer != nil {
+		peer.Peer.Disconnect(p2p.DiscUselessPeer)
+	}
+}
+
+func (pm *ProtocolManager) Start() {
+	if pm.lightSync {
+		// start sync handler
+		go pm.syncer()
+	} else {
+		go func() {
+			for range pm.newPeerCh {
+			}
+		}()
+	}
+}
+
+func (pm *ProtocolManager) Stop() {
+	// Showing a log message. During download / process this could actually
+	// take between 5 to 10 seconds and therefor feedback is required.
+	glog.V(logger.Info).Infoln("Stopping light ethereum protocol handler...")
+
+	// Quit the sync loop.
+	// After this send has completed, no new peers will be accepted.
+	pm.noMorePeers <- struct{}{}
+
+	close(pm.quitSync) // quits syncer, fetcher
+
+	// Disconnect existing sessions.
+	// This also closes the gate for any new registrations on the peer set.
+	// sessions which are already established but not added to pm.peers yet
+	// will exit when they try to register.
+	pm.peers.Close()
+
+	// Wait for any process action
+	pm.wg.Wait()
+
+	glog.V(logger.Info).Infoln("Light ethereum protocol handler stopped")
+}
+
+func (pm *ProtocolManager) newPeer(pv, nv int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
+	return newPeer(pv, nv, p, newMeteredMsgWriter(rw))
+}
+
+// handle is the callback invoked to manage the life cycle of a les peer. When
+// this function terminates, the peer is disconnected.
+func (pm *ProtocolManager) handle(p *peer) error {
+	glog.V(logger.Debug).Infof("%v: peer connected [%s]", p, p.Name())
+
+	// Execute the LES handshake
+	td, head, genesis := pm.blockchain.Status()
+	headNum := core.GetBlockNumber(pm.chainDb, head)
+	if err := p.Handshake(td, head, headNum, genesis, pm.server); err != nil {
+		glog.V(logger.Debug).Infof("%v: handshake failed: %v", p, err)
+		return err
+	}
+	if rw, ok := p.rw.(*meteredMsgReadWriter); ok {
+		rw.Init(p.version)
+	}
+	// Register the peer locally
+	glog.V(logger.Detail).Infof("%v: adding peer", p)
+	if err := pm.peers.Register(p); err != nil {
+		glog.V(logger.Error).Infof("%v: addition failed: %v", p, err)
+		return err
+	}
+	defer func() {
+		if pm.server != nil && pm.server.fcManager != nil && p.fcClient != nil {
+			p.fcClient.Remove(pm.server.fcManager)
+		}
+		pm.removePeer(p.id)
+	}()
+
+	// Register the peer in the downloader. If the downloader considers it banned, we disconnect
+	glog.V(logger.Debug).Infof("LES: register peer %v", p.id)
+	if pm.lightSync {
+		requestHeadersByHash := func(origin common.Hash, amount int, skip int, reverse bool) error {
+			reqID := pm.odr.getNextReqID()
+			cost := p.GetRequestCost(GetBlockHeadersMsg, amount)
+			p.fcServer.SendRequest(reqID, cost)
+			return p.RequestHeadersByHash(reqID, cost, origin, amount, skip, reverse)
+		}
+		requestHeadersByNumber := func(origin uint64, amount int, skip int, reverse bool) error {
+			reqID := pm.odr.getNextReqID()
+			cost := p.GetRequestCost(GetBlockHeadersMsg, amount)
+			p.fcServer.SendRequest(reqID, cost)
+			return p.RequestHeadersByNumber(reqID, cost, origin, amount, skip, reverse)
+		}
+		if err := pm.downloader.RegisterPeer(p.id, ethVersion, p.HeadAndTd,
+			requestHeadersByHash, requestHeadersByNumber, nil, nil, nil); err != nil {
+			return err
+		}
+		pm.odr.RegisterPeer(p)
+		if pm.txrelay != nil {
+			pm.txrelay.addPeer(p)
+		}
+
+		pm.fetcher.notify(p, nil)
+	}
+
+	stop := make(chan struct{})
+	defer close(stop)
+	go func() {
+		// new block announce loop
+		for {
+			select {
+			case announce := <-p.announceChn:
+				p.SendAnnounce(announce)
+				//fmt.Println("  BROADCAST sent")
+			case <-stop:
+				return
+			}
+		}
+	}()
+
+	// main loop. handle incoming messages.
+	for {
+		if err := pm.handleMsg(p); err != nil {
+			glog.V(logger.Debug).Infof("%v: message handling failed: %v", p, err)
+			//fmt.Println("handleMsg err:", err)
+			return err
+		}
+	}
+}
+
+var reqList = []uint64{GetBlockHeadersMsg, GetBlockBodiesMsg, GetCodeMsg, GetReceiptsMsg, GetProofsMsg, SendTxMsg, GetHeaderProofsMsg}
+
+// handleMsg is invoked whenever an inbound message is received from a remote
+// peer. The remote connection is torn down upon returning any error.
+func (pm *ProtocolManager) handleMsg(p *peer) error {
+	// Read the next message from the remote peer, and ensure it's fully consumed
+	msg, err := p.rw.ReadMsg()
+	if err != nil {
+		return err
+	}
+
+	var costs *requestCosts
+	var reqCnt, maxReqs int
+
+	//fmt.Println("MSG", msg.Code, msg.Size)
+	if rc, ok := p.fcCosts[msg.Code]; ok { // check if msg is a supported request type
+		costs = rc
+		if p.fcClient == nil {
+			return errResp(ErrRequestRejected, "")
+		}
+		bv, ok := p.fcClient.AcceptRequest()
+		if !ok || bv < costs.baseCost {
+			return errResp(ErrRequestRejected, "")
+		}
+		maxReqs = 10000
+		if bv < pm.server.defParams.BufLimit {
+			d := bv - costs.baseCost
+			if d/10000 < costs.reqCost {
+				maxReqs = int(d / costs.reqCost)
+			}
+		}
+	}
+
+	if msg.Size > ProtocolMaxMsgSize {
+		return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
+	}
+	defer msg.Discard()
+
+	var deliverMsg *Msg
+
+	// Handle the message depending on its contents
+	switch msg.Code {
+	case StatusMsg:
+		glog.V(logger.Debug).Infof("LES: received StatusMsg from peer %v", p.id)
+		// Status messages should never arrive after the handshake
+		return errResp(ErrExtraStatusMsg, "uncontrolled status message")
+
+	// Block header query, collect the requested headers and reply
+	case AnnounceMsg:
+		var req announceData
+		if err := msg.Decode(&req); err != nil {
+			return errResp(ErrDecode, "%v: %v", msg, err)
+		}
+		//fmt.Println("RECEIVED", req.Number, req.Hash, req.Td, req.ReorgDepth)
+		pm.fetcher.notify(p, &req)
+
+	case GetBlockHeadersMsg:
+		glog.V(logger.Debug).Infof("LES: received GetBlockHeadersMsg from peer %v", p.id)
+		// Decode the complex header query
+		var req struct {
+			ReqID uint64
+			Query getBlockHeadersData
+		}
+		if err := msg.Decode(&req); err != nil {
+			return errResp(ErrDecode, "%v: %v", msg, err)
+		}
+
+		query := req.Query
+		if query.Amount > uint64(maxReqs) || query.Amount > MaxHeaderFetch {
+			return errResp(ErrRequestRejected, "")
+		}
+
+		hashMode := query.Origin.Hash != (common.Hash{})
+
+		// Gather headers until the fetch or network limits is reached
+		var (
+			bytes   common.StorageSize
+			headers []*types.Header
+			unknown bool
+		)
+		for !unknown && len(headers) < int(query.Amount) && bytes < softResponseLimit {
+			// Retrieve the next header satisfying the query
+			var origin *types.Header
+			if hashMode {
+				origin = pm.blockchain.GetHeaderByHash(query.Origin.Hash)
+			} else {
+				origin = pm.blockchain.GetHeaderByNumber(query.Origin.Number)
+			}
+			if origin == nil {
+				break
+			}
+			number := origin.Number.Uint64()
+			headers = append(headers, origin)
+			bytes += estHeaderRlpSize
+
+			// Advance to the next header of the query
+			switch {
+			case query.Origin.Hash != (common.Hash{}) && query.Reverse:
+				// Hash based traversal towards the genesis block
+				for i := 0; i < int(query.Skip)+1; i++ {
+					if header := pm.blockchain.GetHeader(query.Origin.Hash, number); header != nil {
+						query.Origin.Hash = header.ParentHash
+						number--
+					} else {
+						unknown = true
+						break
+					}
+				}
+			case query.Origin.Hash != (common.Hash{}) && !query.Reverse:
+				// Hash based traversal towards the leaf block
+				if header := pm.blockchain.GetHeaderByNumber(origin.Number.Uint64() + query.Skip + 1); header != nil {
+					if pm.blockchain.GetBlockHashesFromHash(header.Hash(), query.Skip+1)[query.Skip] == query.Origin.Hash {
+						query.Origin.Hash = header.Hash()
+					} else {
+						unknown = true
+					}
+				} else {
+					unknown = true
+				}
+			case query.Reverse:
+				// Number based traversal towards the genesis block
+				if query.Origin.Number >= query.Skip+1 {
+					query.Origin.Number -= (query.Skip + 1)
+				} else {
+					unknown = true
+				}
+
+			case !query.Reverse:
+				// Number based traversal towards the leaf block
+				query.Origin.Number += (query.Skip + 1)
+			}
+		}
+
+		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + query.Amount*costs.reqCost)
+		pm.server.fcCostStats.update(msg.Code, query.Amount, rcost)
+		return p.SendBlockHeaders(req.ReqID, bv, headers)
+
+	case BlockHeadersMsg:
+		if pm.downloader == nil {
+			return errResp(ErrUnexpectedResponse, "")
+		}
+
+		glog.V(logger.Debug).Infof("LES: received BlockHeadersMsg from peer %v", p.id)
+		// A batch of headers arrived to one of our previous requests
+		var resp struct {
+			ReqID, BV uint64
+			Headers   []*types.Header
+		}
+		if err := msg.Decode(&resp); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		p.fcServer.GotReply(resp.ReqID, resp.BV)
+		if pm.fetcher.requestedID(resp.ReqID) {
+			pm.fetcher.deliverHeaders(resp.ReqID, resp.Headers)
+		} else {
+			err := pm.downloader.DeliverHeaders(p.id, resp.Headers)
+			if err != nil {
+				glog.V(logger.Debug).Infoln(err)
+			}
+		}
+
+	case GetBlockBodiesMsg:
+		glog.V(logger.Debug).Infof("LES: received GetBlockBodiesMsg from peer %v", p.id)
+		// Decode the retrieval message
+		var req struct {
+			ReqID  uint64
+			Hashes []common.Hash
+		}
+		if err := msg.Decode(&req); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		// Gather blocks until the fetch or network limits is reached
+		var (
+			bytes  int
+			bodies []rlp.RawValue
+		)
+		reqCnt = len(req.Hashes)
+		if reqCnt > maxReqs || reqCnt > MaxBodyFetch {
+			return errResp(ErrRequestRejected, "")
+		}
+		for _, hash := range req.Hashes {
+			if bytes >= softResponseLimit {
+				break
+			}
+			// Retrieve the requested block body, stopping if enough was found
+			if data := core.GetBodyRLP(pm.chainDb, hash, core.GetBlockNumber(pm.chainDb, hash)); len(data) != 0 {
+				bodies = append(bodies, data)
+				bytes += len(data)
+			}
+		}
+		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
+		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
+		return p.SendBlockBodiesRLP(req.ReqID, bv, bodies)
+
+	case BlockBodiesMsg:
+		if pm.odr == nil {
+			return errResp(ErrUnexpectedResponse, "")
+		}
+
+		glog.V(logger.Debug).Infof("LES: received BlockBodiesMsg from peer %v", p.id)
+		// A batch of block bodies arrived to one of our previous requests
+		var resp struct {
+			ReqID, BV uint64
+			Data      []*types.Body
+		}
+		if err := msg.Decode(&resp); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		p.fcServer.GotReply(resp.ReqID, resp.BV)
+		deliverMsg = &Msg{
+			MsgType: MsgBlockBodies,
+			ReqID:   resp.ReqID,
+			Obj:     resp.Data,
+		}
+
+	case GetCodeMsg:
+		glog.V(logger.Debug).Infof("LES: received GetCodeMsg from peer %v", p.id)
+		// Decode the retrieval message
+		var req struct {
+			ReqID uint64
+			Reqs  []CodeReq
+		}
+		if err := msg.Decode(&req); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		// Gather state data until the fetch or network limits is reached
+		var (
+			bytes int
+			data  [][]byte
+		)
+		reqCnt = len(req.Reqs)
+		if reqCnt > maxReqs || reqCnt > MaxCodeFetch {
+			return errResp(ErrRequestRejected, "")
+		}
+		for _, req := range req.Reqs {
+			// Retrieve the requested state entry, stopping if enough was found
+			if header := core.GetHeader(pm.chainDb, req.BHash, core.GetBlockNumber(pm.chainDb, req.BHash)); header != nil {
+				if trie, _ := trie.New(header.Root, pm.chainDb); trie != nil {
+					sdata := trie.Get(req.AccKey)
+					var acc state.Account
+					if err := rlp.DecodeBytes(sdata, &acc); err == nil {
+						entry, _ := pm.chainDb.Get(acc.CodeHash)
+						if bytes+len(entry) >= softResponseLimit {
+							break
+						}
+						data = append(data, entry)
+						bytes += len(entry)
+					}
+				}
+			}
+		}
+		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
+		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
+		return p.SendCode(req.ReqID, bv, data)
+
+	case CodeMsg:
+		if pm.odr == nil {
+			return errResp(ErrUnexpectedResponse, "")
+		}
+
+		glog.V(logger.Debug).Infof("LES: received CodeMsg from peer %v", p.id)
+		// A batch of node state data arrived to one of our previous requests
+		var resp struct {
+			ReqID, BV uint64
+			Data      [][]byte
+		}
+		if err := msg.Decode(&resp); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		p.fcServer.GotReply(resp.ReqID, resp.BV)
+		deliverMsg = &Msg{
+			MsgType: MsgCode,
+			ReqID:   resp.ReqID,
+			Obj:     resp.Data,
+		}
+
+	case GetReceiptsMsg:
+		glog.V(logger.Debug).Infof("LES: received GetReceiptsMsg from peer %v", p.id)
+		// Decode the retrieval message
+		var req struct {
+			ReqID  uint64
+			Hashes []common.Hash
+		}
+		if err := msg.Decode(&req); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		// Gather state data until the fetch or network limits is reached
+		var (
+			bytes    int
+			receipts []rlp.RawValue
+		)
+		reqCnt = len(req.Hashes)
+		if reqCnt > maxReqs || reqCnt > MaxReceiptFetch {
+			return errResp(ErrRequestRejected, "")
+		}
+		for _, hash := range req.Hashes {
+			if bytes >= softResponseLimit {
+				break
+			}
+			// Retrieve the requested block's receipts, skipping if unknown to us
+			results := core.GetBlockReceipts(pm.chainDb, hash, core.GetBlockNumber(pm.chainDb, hash))
+			if results == nil {
+				if header := pm.blockchain.GetHeaderByHash(hash); header == nil || header.ReceiptHash != types.EmptyRootHash {
+					continue
+				}
+			}
+			// If known, encode and queue for response packet
+			if encoded, err := rlp.EncodeToBytes(results); err != nil {
+				glog.V(logger.Error).Infof("failed to encode receipt: %v", err)
+			} else {
+				receipts = append(receipts, encoded)
+				bytes += len(encoded)
+			}
+		}
+		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
+		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
+		return p.SendReceiptsRLP(req.ReqID, bv, receipts)
+
+	case ReceiptsMsg:
+		if pm.odr == nil {
+			return errResp(ErrUnexpectedResponse, "")
+		}
+
+		glog.V(logger.Debug).Infof("LES: received ReceiptsMsg from peer %v", p.id)
+		// A batch of receipts arrived to one of our previous requests
+		var resp struct {
+			ReqID, BV uint64
+			Receipts  []types.Receipts
+		}
+		if err := msg.Decode(&resp); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		p.fcServer.GotReply(resp.ReqID, resp.BV)
+		deliverMsg = &Msg{
+			MsgType: MsgReceipts,
+			ReqID:   resp.ReqID,
+			Obj:     resp.Receipts,
+		}
+
+	case GetProofsMsg:
+		glog.V(logger.Debug).Infof("LES: received GetProofsMsg from peer %v", p.id)
+		// Decode the retrieval message
+		var req struct {
+			ReqID uint64
+			Reqs  []ProofReq
+		}
+		if err := msg.Decode(&req); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		// Gather state data until the fetch or network limits is reached
+		var (
+			bytes  int
+			proofs proofsData
+		)
+		reqCnt = len(req.Reqs)
+		if reqCnt > maxReqs || reqCnt > MaxProofsFetch {
+			return errResp(ErrRequestRejected, "")
+		}
+		for _, req := range req.Reqs {
+			if bytes >= softResponseLimit {
+				break
+			}
+			// Retrieve the requested state entry, stopping if enough was found
+			if header := core.GetHeader(pm.chainDb, req.BHash, core.GetBlockNumber(pm.chainDb, req.BHash)); header != nil {
+				if tr, _ := trie.New(header.Root, pm.chainDb); tr != nil {
+					if len(req.AccKey) > 0 {
+						sdata := tr.Get(req.AccKey)
+						tr = nil
+						var acc state.Account
+						if err := rlp.DecodeBytes(sdata, &acc); err == nil {
+							tr, _ = trie.New(acc.Root, pm.chainDb)
+						}
+					}
+					if tr != nil {
+						proof := tr.Prove(req.Key)
+						proofs = append(proofs, proof)
+						bytes += len(proof)
+					}
+				}
+			}
+		}
+		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
+		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
+		return p.SendProofs(req.ReqID, bv, proofs)
+
+	case ProofsMsg:
+		if pm.odr == nil {
+			return errResp(ErrUnexpectedResponse, "")
+		}
+
+		glog.V(logger.Debug).Infof("LES: received ProofsMsg from peer %v", p.id)
+		// A batch of merkle proofs arrived to one of our previous requests
+		var resp struct {
+			ReqID, BV uint64
+			Data      [][]rlp.RawValue
+		}
+		if err := msg.Decode(&resp); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		p.fcServer.GotReply(resp.ReqID, resp.BV)
+		deliverMsg = &Msg{
+			MsgType: MsgProofs,
+			ReqID:   resp.ReqID,
+			Obj:     resp.Data,
+		}
+
+	case GetHeaderProofsMsg:
+		glog.V(logger.Debug).Infof("LES: received GetHeaderProofsMsg from peer %v", p.id)
+		// Decode the retrieval message
+		var req struct {
+			ReqID uint64
+			Reqs  []ChtReq
+		}
+		if err := msg.Decode(&req); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		// Gather state data until the fetch or network limits is reached
+		var (
+			bytes  int
+			proofs []ChtResp
+		)
+		reqCnt = len(req.Reqs)
+		if reqCnt > maxReqs || reqCnt > MaxHeaderProofsFetch {
+			return errResp(ErrRequestRejected, "")
+		}
+		for _, req := range req.Reqs {
+			if bytes >= softResponseLimit {
+				break
+			}
+
+			if header := pm.blockchain.GetHeaderByNumber(req.BlockNum); header != nil {
+				if root := getChtRoot(pm.chainDb, req.ChtNum); root != (common.Hash{}) {
+					if tr, _ := trie.New(root, pm.chainDb); tr != nil {
+						var encNumber [8]byte
+						binary.BigEndian.PutUint64(encNumber[:], req.BlockNum)
+						proof := tr.Prove(encNumber[:])
+						proofs = append(proofs, ChtResp{Header: header, Proof: proof})
+						bytes += len(proof) + estHeaderRlpSize
+					}
+				}
+			}
+		}
+		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
+		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
+		return p.SendHeaderProofs(req.ReqID, bv, proofs)
+
+	case HeaderProofsMsg:
+		if pm.odr == nil {
+			return errResp(ErrUnexpectedResponse, "")
+		}
+
+		glog.V(logger.Debug).Infof("LES: received HeaderProofsMsg from peer %v", p.id)
+		var resp struct {
+			ReqID, BV uint64
+			Data      []ChtResp
+		}
+		if err := msg.Decode(&resp); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		p.fcServer.GotReply(resp.ReqID, resp.BV)
+		deliverMsg = &Msg{
+			MsgType: MsgHeaderProofs,
+			ReqID:   resp.ReqID,
+			Obj:     resp.Data,
+		}
+
+	case SendTxMsg:
+		if pm.txpool == nil {
+			return errResp(ErrUnexpectedResponse, "")
+		}
+		// Transactions arrived, parse all of them and deliver to the pool
+		var txs []*types.Transaction
+		if err := msg.Decode(&txs); err != nil {
+			return errResp(ErrDecode, "msg %v: %v", msg, err)
+		}
+		reqCnt = len(txs)
+		if reqCnt > maxReqs || reqCnt > MaxTxSend {
+			return errResp(ErrRequestRejected, "")
+		}
+		pm.txpool.AddBatch(txs)
+		_, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
+		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
+
+	default:
+		glog.V(logger.Debug).Infof("LES: received unknown message with code %d from peer %v", msg.Code, p.id)
+		return errResp(ErrInvalidMsgCode, "%v", msg.Code)
+	}
+
+	if deliverMsg != nil {
+		return pm.odr.Deliver(p, deliverMsg)
+	}
+
+	return nil
+}
+
+// NodeInfo retrieves some protocol metadata about the running host node.
+func (self *ProtocolManager) NodeInfo() *eth.EthNodeInfo {
+	return &eth.EthNodeInfo{
+		Network:    self.networkId,
+		Difficulty: self.blockchain.GetTdByHash(self.blockchain.LastBlockHash()),
+		Genesis:    self.blockchain.Genesis().Hash(),
+		Head:       self.blockchain.LastBlockHash(),
+	}
+}

les/handler_test.go

+package les
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+func expectResponse(r p2p.MsgReader, msgcode, reqID, bv uint64, data interface{}) error {
+	type resp struct {
+		ReqID, BV uint64
+		Data      interface{}
+	}
+	return p2p.ExpectMsg(r, msgcode, resp{reqID, bv, data})
+}
+
+// Tests that block headers can be retrieved from a remote chain based on user queries.
+func TestGetBlockHeadersLes1(t *testing.T) { testGetBlockHeaders(t, 1) }
+
+func testGetBlockHeaders(t *testing.T, protocol int) {
+	pm, _, _ := newTestProtocolManagerMust(t, false, downloader.MaxHashFetch+15, nil)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	// Create a "random" unknown hash for testing
+	var unknown common.Hash
+	for i, _ := range unknown {
+		unknown[i] = byte(i)
+	}
+	// Create a batch of tests for various scenarios
+	limit := uint64(MaxHeaderFetch)
+	tests := []struct {
+		query  *getBlockHeadersData // The query to execute for header retrieval
+		expect []common.Hash        // The hashes of the block whose headers are expected
+	}{
+		// A single random block should be retrievable by hash and number too
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Hash: bc.GetBlockByNumber(limit / 2).Hash()}, Amount: 1},
+			[]common.Hash{bc.GetBlockByNumber(limit / 2).Hash()},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 1},
+			[]common.Hash{bc.GetBlockByNumber(limit / 2).Hash()},
+		},
+		// Multiple headers should be retrievable in both directions
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 + 1).Hash(),
+				bc.GetBlockByNumber(limit/2 + 2).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 - 1).Hash(),
+				bc.GetBlockByNumber(limit/2 - 2).Hash(),
+			},
+		},
+		// Multiple headers with skip lists should be retrievable
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Skip: 3, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 + 4).Hash(),
+				bc.GetBlockByNumber(limit/2 + 8).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Skip: 3, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(limit / 2).Hash(),
+				bc.GetBlockByNumber(limit/2 - 4).Hash(),
+				bc.GetBlockByNumber(limit/2 - 8).Hash(),
+			},
+		},
+		// The chain endpoints should be retrievable
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: 0}, Amount: 1},
+			[]common.Hash{bc.GetBlockByNumber(0).Hash()},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64()}, Amount: 1},
+			[]common.Hash{bc.CurrentBlock().Hash()},
+		},
+		// Ensure protocol limits are honored
+		/*{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() - 1}, Amount: limit + 10, Reverse: true},
+			bc.GetBlockHashesFromHash(bc.CurrentBlock().Hash(), limit),
+		},*/
+		// Check that requesting more than available is handled gracefully
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() - 4}, Skip: 3, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64() - 4).Hash(),
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64()).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: 4}, Skip: 3, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(4).Hash(),
+				bc.GetBlockByNumber(0).Hash(),
+			},
+		},
+		// Check that requesting more than available is handled gracefully, even if mid skip
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() - 4}, Skip: 2, Amount: 3},
+			[]common.Hash{
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64() - 4).Hash(),
+				bc.GetBlockByNumber(bc.CurrentBlock().NumberU64() - 1).Hash(),
+			},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: 4}, Skip: 2, Amount: 3, Reverse: true},
+			[]common.Hash{
+				bc.GetBlockByNumber(4).Hash(),
+				bc.GetBlockByNumber(1).Hash(),
+			},
+		},
+		// Check that non existing headers aren't returned
+		{
+			&getBlockHeadersData{Origin: hashOrNumber{Hash: unknown}, Amount: 1},
+			[]common.Hash{},
+		}, {
+			&getBlockHeadersData{Origin: hashOrNumber{Number: bc.CurrentBlock().NumberU64() + 1}, Amount: 1},
+			[]common.Hash{},
+		},
+	}
+	// Run each of the tests and verify the results against the chain
+	var reqID uint64
+	for i, tt := range tests {
+		// Collect the headers to expect in the response
+		headers := []*types.Header{}
+		for _, hash := range tt.expect {
+			headers = append(headers, bc.GetHeaderByHash(hash))
+		}
+		// Send the hash request and verify the response
+		reqID++
+		cost := peer.GetRequestCost(GetBlockHeadersMsg, int(tt.query.Amount))
+		sendRequest(peer.app, GetBlockHeadersMsg, reqID, cost, tt.query)
+		if err := expectResponse(peer.app, BlockHeadersMsg, reqID, testBufLimit, headers); err != nil {
+			t.Errorf("test %d: headers mismatch: %v", i, err)
+		}
+	}
+}
+
+// Tests that block contents can be retrieved from a remote chain based on their hashes.
+func TestGetBlockBodiesLes1(t *testing.T) { testGetBlockBodies(t, 1) }
+
+func testGetBlockBodies(t *testing.T, protocol int) {
+	pm, _, _ := newTestProtocolManagerMust(t, false, downloader.MaxBlockFetch+15, nil)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	// Create a batch of tests for various scenarios
+	limit := MaxBodyFetch
+	tests := []struct {
+		random    int           // Number of blocks to fetch randomly from the chain
+		explicit  []common.Hash // Explicitly requested blocks
+		available []bool        // Availability of explicitly requested blocks
+		expected  int           // Total number of existing blocks to expect
+	}{
+		{1, nil, nil, 1},         // A single random block should be retrievable
+		{10, nil, nil, 10},       // Multiple random blocks should be retrievable
+		{limit, nil, nil, limit}, // The maximum possible blocks should be retrievable
+		//{limit + 1, nil, nil, limit},                                  // No more than the possible block count should be returned
+		{0, []common.Hash{bc.Genesis().Hash()}, []bool{true}, 1},      // The genesis block should be retrievable
+		{0, []common.Hash{bc.CurrentBlock().Hash()}, []bool{true}, 1}, // The chains head block should be retrievable
+		{0, []common.Hash{common.Hash{}}, []bool{false}, 0},           // A non existent block should not be returned
+
+		// Existing and non-existing blocks interleaved should not cause problems
+		{0, []common.Hash{
+			common.Hash{},
+			bc.GetBlockByNumber(1).Hash(),
+			common.Hash{},
+			bc.GetBlockByNumber(10).Hash(),
+			common.Hash{},
+			bc.GetBlockByNumber(100).Hash(),
+			common.Hash{},
+		}, []bool{false, true, false, true, false, true, false}, 3},
+	}
+	// Run each of the tests and verify the results against the chain
+	var reqID uint64
+	for i, tt := range tests {
+		// Collect the hashes to request, and the response to expect
+		hashes, seen := []common.Hash{}, make(map[int64]bool)
+		bodies := []*types.Body{}
+
+		for j := 0; j < tt.random; j++ {
+			for {
+				num := rand.Int63n(int64(bc.CurrentBlock().NumberU64()))
+				if !seen[num] {
+					seen[num] = true
+
+					block := bc.GetBlockByNumber(uint64(num))
+					hashes = append(hashes, block.Hash())
+					if len(bodies) < tt.expected {
+						bodies = append(bodies, &types.Body{Transactions: block.Transactions(), Uncles: block.Uncles()})
+					}
+					break
+				}
+			}
+		}
+		for j, hash := range tt.explicit {
+			hashes = append(hashes, hash)
+			if tt.available[j] && len(bodies) < tt.expected {
+				block := bc.GetBlockByHash(hash)
+				bodies = append(bodies, &types.Body{Transactions: block.Transactions(), Uncles: block.Uncles()})
+			}
+		}
+		reqID++
+		// Send the hash request and verify the response
+		cost := peer.GetRequestCost(GetBlockBodiesMsg, len(hashes))
+		sendRequest(peer.app, GetBlockBodiesMsg, reqID, cost, hashes)
+		if err := expectResponse(peer.app, BlockBodiesMsg, reqID, testBufLimit, bodies); err != nil {
+			t.Errorf("test %d: bodies mismatch: %v", i, err)
+		}
+	}
+}
+
+// Tests that the contract codes can be retrieved based on account addresses.
+func TestGetCodeLes1(t *testing.T) { testGetCode(t, 1) }
+
+func testGetCode(t *testing.T, protocol int) {
+	// Assemble the test environment
+	pm, _, _ := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	var codereqs []*CodeReq
+	var codes [][]byte
+
+	for i := uint64(0); i <= bc.CurrentBlock().NumberU64(); i++ {
+		header := bc.GetHeaderByNumber(i)
+		req := &CodeReq{
+			BHash:  header.Hash(),
+			AccKey: crypto.Keccak256(testContractAddr[:]),
+		}
+		codereqs = append(codereqs, req)
+		if i >= testContractDeployed {
+			codes = append(codes, testContractCodeDeployed)
+		}
+	}
+
+	cost := peer.GetRequestCost(GetCodeMsg, len(codereqs))
+	sendRequest(peer.app, GetCodeMsg, 42, cost, codereqs)
+	if err := expectResponse(peer.app, CodeMsg, 42, testBufLimit, codes); err != nil {
+		t.Errorf("codes mismatch: %v", err)
+	}
+}
+
+// Tests that the transaction receipts can be retrieved based on hashes.
+func TestGetReceiptLes1(t *testing.T) { testGetReceipt(t, 1) }
+
+func testGetReceipt(t *testing.T, protocol int) {
+	// Assemble the test environment
+	pm, db, _ := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	// Collect the hashes to request, and the response to expect
+	hashes, receipts := []common.Hash{}, []types.Receipts{}
+	for i := uint64(0); i <= bc.CurrentBlock().NumberU64(); i++ {
+		block := bc.GetBlockByNumber(i)
+
+		hashes = append(hashes, block.Hash())
+		receipts = append(receipts, core.GetBlockReceipts(db, block.Hash(), block.NumberU64()))
+	}
+	// Send the hash request and verify the response
+	cost := peer.GetRequestCost(GetReceiptsMsg, len(hashes))
+	sendRequest(peer.app, GetReceiptsMsg, 42, cost, hashes)
+	if err := expectResponse(peer.app, ReceiptsMsg, 42, testBufLimit, receipts); err != nil {
+		t.Errorf("receipts mismatch: %v", err)
+	}
+}
+
+// Tests that trie merkle proofs can be retrieved
+func TestGetProofsLes1(t *testing.T) { testGetReceipt(t, 1) }
+
+func testGetProofs(t *testing.T, protocol int) {
+	// Assemble the test environment
+	pm, db, _ := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	var proofreqs []ProofReq
+	var proofs [][]rlp.RawValue
+
+	accounts := []common.Address{testBankAddress, acc1Addr, acc2Addr, common.Address{}}
+	for i := uint64(0); i <= bc.CurrentBlock().NumberU64(); i++ {
+		header := bc.GetHeaderByNumber(i)
+		root := header.Root
+		trie, _ := trie.New(root, db)
+
+		for _, acc := range accounts {
+			req := ProofReq{
+				BHash: header.Hash(),
+				Key:   acc[:],
+			}
+			proofreqs = append(proofreqs, req)
+
+			proof := trie.Prove(crypto.Keccak256(acc[:]))
+			proofs = append(proofs, proof)
+		}
+	}
+	// Send the proof request and verify the response
+	cost := peer.GetRequestCost(GetProofsMsg, len(proofreqs))
+	sendRequest(peer.app, GetProofsMsg, 42, cost, proofreqs)
+	if err := expectResponse(peer.app, ProofsMsg, 42, testBufLimit, proofs); err != nil {
+		t.Errorf("proofs mismatch: %v", err)
+	}
+}

les/helper_test.go

+// This file contains some shares testing functionality, common to  multiple
+// different files and modules being tested.
+
+package les
+
+import (
+	"crypto/ecdsa"
+	"crypto/rand"
+	"math/big"
+	"sync"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/les/flowcontrol"
+	"github.com/ethereum/go-ethereum/light"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+var (
+	testBankKey, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+	testBankAddress = crypto.PubkeyToAddress(testBankKey.PublicKey)
+	testBankFunds   = big.NewInt(1000000)
+
+	acc1Key, _ = crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
+	acc2Key, _ = crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
+	acc1Addr   = crypto.PubkeyToAddress(acc1Key.PublicKey)
+	acc2Addr   = crypto.PubkeyToAddress(acc2Key.PublicKey)
+
+	testContractCode         = common.Hex2Bytes("606060405260cc8060106000396000f360606040526000357c01000000000000000000000000000000000000000000000000000000009004806360cd2685146041578063c16431b914606b57603f565b005b6055600480803590602001909190505060a9565b6040518082815260200191505060405180910390f35b60886004808035906020019091908035906020019091905050608a565b005b80600060005083606481101560025790900160005b50819055505b5050565b6000600060005082606481101560025790900160005b5054905060c7565b91905056")
+	testContractAddr         common.Address
+	testContractCodeDeployed = testContractCode[16:]
+	testContractDeployed     = uint64(2)
+
+	testBufLimit = uint64(100)
+)
+
+/*
+contract test {
+
+    uint256[100] data;
+
+    function Put(uint256 addr, uint256 value) {
+        data[addr] = value;
+    }
+
+    function Get(uint256 addr) constant returns (uint256 value) {
+        return data[addr];
+    }
+}
+*/
+
+func testChainGen(i int, block *core.BlockGen) {
+	switch i {
+	case 0:
+		// In block 1, the test bank sends account #1 some ether.
+		tx, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(testBankKey)
+		block.AddTx(tx)
+	case 1:
+		// In block 2, the test bank sends some more ether to account #1.
+		// acc1Addr passes it on to account #2.
+		// acc1Addr creates a test contract.
+		tx1, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(testBankKey)
+		nonce := block.TxNonce(acc1Addr)
+		tx2, _ := types.NewTransaction(nonce, acc2Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(acc1Key)
+		nonce++
+		tx3, _ := types.NewContractCreation(nonce, big.NewInt(0), big.NewInt(200000), big.NewInt(0), testContractCode).SignECDSA(acc1Key)
+		testContractAddr = crypto.CreateAddress(acc1Addr, nonce)
+		block.AddTx(tx1)
+		block.AddTx(tx2)
+		block.AddTx(tx3)
+	case 2:
+		// Block 3 is empty but was mined by account #2.
+		block.SetCoinbase(acc2Addr)
+		block.SetExtra([]byte("yeehaw"))
+		data := common.Hex2Bytes("C16431B900000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000001")
+		tx, _ := types.NewTransaction(block.TxNonce(testBankAddress), testContractAddr, big.NewInt(0), big.NewInt(100000), nil, data).SignECDSA(testBankKey)
+		block.AddTx(tx)
+	case 3:
+		// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
+		b2 := block.PrevBlock(1).Header()
+		b2.Extra = []byte("foo")
+		block.AddUncle(b2)
+		b3 := block.PrevBlock(2).Header()
+		b3.Extra = []byte("foo")
+		block.AddUncle(b3)
+		data := common.Hex2Bytes("C16431B900000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000002")
+		tx, _ := types.NewTransaction(block.TxNonce(testBankAddress), testContractAddr, big.NewInt(0), big.NewInt(100000), nil, data).SignECDSA(testBankKey)
+		block.AddTx(tx)
+	}
+}
+
+func testRCL() RequestCostList {
+	cl := make(RequestCostList, len(reqList))
+	for i, code := range reqList {
+		cl[i].MsgCode = code
+		cl[i].BaseCost = 0
+		cl[i].ReqCost = 0
+	}
+	return cl
+}
+
+// newTestProtocolManager creates a new protocol manager for testing purposes,
+// with the given number of blocks already known, and potential notification
+// channels for different events.
+func newTestProtocolManager(lightSync bool, blocks int, generator func(int, *core.BlockGen)) (*ProtocolManager, ethdb.Database, *LesOdr, error) {
+	var (
+		evmux       = new(event.TypeMux)
+		pow         = new(core.FakePow)
+		db, _       = ethdb.NewMemDatabase()
+		genesis     = core.WriteGenesisBlockForTesting(db, core.GenesisAccount{Address: testBankAddress, Balance: testBankFunds})
+		chainConfig = &core.ChainConfig{HomesteadBlock: big.NewInt(0)} // homestead set to 0 because of chain maker
+		odr         *LesOdr
+		chain       BlockChain
+	)
+
+	if lightSync {
+		odr = NewLesOdr(db)
+		chain, _ = light.NewLightChain(odr, chainConfig, pow, evmux)
+	} else {
+		blockchain, _ := core.NewBlockChain(db, chainConfig, pow, evmux)
+		gchain, _ := core.GenerateChain(nil, genesis, db, blocks, generator)
+		if _, err := blockchain.InsertChain(gchain); err != nil {
+			panic(err)
+		}
+		chain = blockchain
+	}
+
+	pm, err := NewProtocolManager(chainConfig, lightSync, NetworkId, evmux, pow, chain, nil, db, odr, nil)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	if !lightSync {
+		srv := &LesServer{protocolManager: pm}
+		pm.server = srv
+
+		srv.defParams = &flowcontrol.ServerParams{
+			BufLimit:    testBufLimit,
+			MinRecharge: 1,
+		}
+
+		srv.fcManager = flowcontrol.NewClientManager(50, 10, 1000000000)
+		srv.fcCostStats = newCostStats(nil)
+	}
+	pm.Start()
+	return pm, db, odr, nil
+}
+
+// newTestProtocolManagerMust creates a new protocol manager for testing purposes,
+// with the given number of blocks already known, and potential notification
+// channels for different events. In case of an error, the constructor force-
+// fails the test.
+func newTestProtocolManagerMust(t *testing.T, lightSync bool, blocks int, generator func(int, *core.BlockGen)) (*ProtocolManager, ethdb.Database, *LesOdr) {
+	pm, db, odr, err := newTestProtocolManager(lightSync, blocks, generator)
+	if err != nil {
+		t.Fatalf("Failed to create protocol manager: %v", err)
+	}
+	return pm, db, odr
+}
+
+// testTxPool is a fake, helper transaction pool for testing purposes
+type testTxPool struct {
+	pool  []*types.Transaction        // Collection of all transactions
+	added chan<- []*types.Transaction // Notification channel for new transactions
+
+	lock sync.RWMutex // Protects the transaction pool
+}
+
+// AddTransactions appends a batch of transactions to the pool, and notifies any
+// listeners if the addition channel is non nil
+func (p *testTxPool) AddBatch(txs []*types.Transaction) {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	p.pool = append(p.pool, txs...)
+	if p.added != nil {
+		p.added <- txs
+	}
+}
+
+// GetTransactions returns all the transactions known to the pool
+func (p *testTxPool) GetTransactions() types.Transactions {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+
+	txs := make([]*types.Transaction, len(p.pool))
+	copy(txs, p.pool)
+
+	return txs
+}
+
+// newTestTransaction create a new dummy transaction.
+func newTestTransaction(from *ecdsa.PrivateKey, nonce uint64, datasize int) *types.Transaction {
+	tx := types.NewTransaction(nonce, common.Address{}, big.NewInt(0), big.NewInt(100000), big.NewInt(0), make([]byte, datasize))
+	tx, _ = tx.SignECDSA(from)
+
+	return tx
+}
+
+// testPeer is a simulated peer to allow testing direct network calls.
+type testPeer struct {
+	net p2p.MsgReadWriter // Network layer reader/writer to simulate remote messaging
+	app *p2p.MsgPipeRW    // Application layer reader/writer to simulate the local side
+	*peer
+}
+
+// newTestPeer creates a new peer registered at the given protocol manager.
+func newTestPeer(t *testing.T, name string, version int, pm *ProtocolManager, shake bool) (*testPeer, <-chan error) {
+	// Create a message pipe to communicate through
+	app, net := p2p.MsgPipe()
+
+	// Generate a random id and create the peer
+	var id discover.NodeID
+	rand.Read(id[:])
+
+	peer := pm.newPeer(version, NetworkId, p2p.NewPeer(id, name, nil), net)
+
+	// Start the peer on a new thread
+	errc := make(chan error, 1)
+	go func() {
+		select {
+		case pm.newPeerCh <- peer:
+			errc <- pm.handle(peer)
+		case <-pm.quitSync:
+			errc <- p2p.DiscQuitting
+		}
+	}()
+	tp := &testPeer{
+		app:  app,
+		net:  net,
+		peer: peer,
+	}
+	// Execute any implicitly requested handshakes and return
+	if shake {
+		td, head, genesis := pm.blockchain.Status()
+		headNum := pm.blockchain.CurrentHeader().Number.Uint64()
+		tp.handshake(t, td, head, headNum, genesis)
+	}
+	return tp, errc
+}
+
+func newTestPeerPair(name string, version int, pm, pm2 *ProtocolManager) (*peer, <-chan error, *peer, <-chan error) {
+	// Create a message pipe to communicate through
+	app, net := p2p.MsgPipe()
+
+	// Generate a random id and create the peer
+	var id discover.NodeID
+	rand.Read(id[:])
+
+	peer := pm.newPeer(version, NetworkId, p2p.NewPeer(id, name, nil), net)
+	peer2 := pm2.newPeer(version, NetworkId, p2p.NewPeer(id, name, nil), app)
+
+	// Start the peer on a new thread
+	errc := make(chan error, 1)
+	errc2 := make(chan error, 1)
+	go func() {
+		select {
+		case pm.newPeerCh <- peer:
+			errc <- pm.handle(peer)
+		case <-pm.quitSync:
+			errc <- p2p.DiscQuitting
+		}
+	}()
+	go func() {
+		select {
+		case pm2.newPeerCh <- peer2:
+			errc2 <- pm2.handle(peer2)
+		case <-pm2.quitSync:
+			errc2 <- p2p.DiscQuitting
+		}
+	}()
+	return peer, errc, peer2, errc2
+}
+
+// handshake simulates a trivial handshake that expects the same state from the
+// remote side as we are simulating locally.
+func (p *testPeer) handshake(t *testing.T, td *big.Int, head common.Hash, headNum uint64, genesis common.Hash) {
+	var expList keyValueList
+	expList = expList.add("protocolVersion", uint64(p.version))
+	expList = expList.add("networkId", uint64(NetworkId))
+	expList = expList.add("headTd", td)
+	expList = expList.add("headHash", head)
+	expList = expList.add("headNum", headNum)
+	expList = expList.add("genesisHash", genesis)
+	sendList := make(keyValueList, len(expList))
+	copy(sendList, expList)
+	expList = expList.add("serveHeaders", nil)
+	expList = expList.add("serveChainSince", uint64(0))
+	expList = expList.add("serveStateSince", uint64(0))
+	expList = expList.add("txRelay", nil)
+	expList = expList.add("flowControl/BL", testBufLimit)
+	expList = expList.add("flowControl/MRR", uint64(1))
+	expList = expList.add("flowControl/MRC", testRCL())
+
+	if err := p2p.ExpectMsg(p.app, StatusMsg, expList); err != nil {
+		t.Fatalf("status recv: %v", err)
+	}
+	if err := p2p.Send(p.app, StatusMsg, sendList); err != nil {
+		t.Fatalf("status send: %v", err)
+	}
+
+	p.fcServerParams = &flowcontrol.ServerParams{
+		BufLimit:    testBufLimit,
+		MinRecharge: 1,
+	}
+}
+
+// close terminates the local side of the peer, notifying the remote protocol
+// manager of termination.
+func (p *testPeer) close() {
+	p.app.Close()
+}

les/metrics.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package les
+
+import (
+	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethereum/go-ethereum/p2p"
+)
+
+var (
+	/*	propTxnInPacketsMeter     = metrics.NewMeter("eth/prop/txns/in/packets")
+		propTxnInTrafficMeter     = metrics.NewMeter("eth/prop/txns/in/traffic")
+		propTxnOutPacketsMeter    = metrics.NewMeter("eth/prop/txns/out/packets")
+		propTxnOutTrafficMeter    = metrics.NewMeter("eth/prop/txns/out/traffic")
+		propHashInPacketsMeter    = metrics.NewMeter("eth/prop/hashes/in/packets")
+		propHashInTrafficMeter    = metrics.NewMeter("eth/prop/hashes/in/traffic")
+		propHashOutPacketsMeter   = metrics.NewMeter("eth/prop/hashes/out/packets")
+		propHashOutTrafficMeter   = metrics.NewMeter("eth/prop/hashes/out/traffic")
+		propBlockInPacketsMeter   = metrics.NewMeter("eth/prop/blocks/in/packets")
+		propBlockInTrafficMeter   = metrics.NewMeter("eth/prop/blocks/in/traffic")
+		propBlockOutPacketsMeter  = metrics.NewMeter("eth/prop/blocks/out/packets")
+		propBlockOutTrafficMeter  = metrics.NewMeter("eth/prop/blocks/out/traffic")
+		reqHashInPacketsMeter     = metrics.NewMeter("eth/req/hashes/in/packets")
+		reqHashInTrafficMeter     = metrics.NewMeter("eth/req/hashes/in/traffic")
+		reqHashOutPacketsMeter    = metrics.NewMeter("eth/req/hashes/out/packets")
+		reqHashOutTrafficMeter    = metrics.NewMeter("eth/req/hashes/out/traffic")
+		reqBlockInPacketsMeter    = metrics.NewMeter("eth/req/blocks/in/packets")
+		reqBlockInTrafficMeter    = metrics.NewMeter("eth/req/blocks/in/traffic")
+		reqBlockOutPacketsMeter   = metrics.NewMeter("eth/req/blocks/out/packets")
+		reqBlockOutTrafficMeter   = metrics.NewMeter("eth/req/blocks/out/traffic")
+		reqHeaderInPacketsMeter   = metrics.NewMeter("eth/req/headers/in/packets")
+		reqHeaderInTrafficMeter   = metrics.NewMeter("eth/req/headers/in/traffic")
+		reqHeaderOutPacketsMeter  = metrics.NewMeter("eth/req/headers/out/packets")
+		reqHeaderOutTrafficMeter  = metrics.NewMeter("eth/req/headers/out/traffic")
+		reqBodyInPacketsMeter     = metrics.NewMeter("eth/req/bodies/in/packets")
+		reqBodyInTrafficMeter     = metrics.NewMeter("eth/req/bodies/in/traffic")
+		reqBodyOutPacketsMeter    = metrics.NewMeter("eth/req/bodies/out/packets")
+		reqBodyOutTrafficMeter    = metrics.NewMeter("eth/req/bodies/out/traffic")
+		reqStateInPacketsMeter    = metrics.NewMeter("eth/req/states/in/packets")
+		reqStateInTrafficMeter    = metrics.NewMeter("eth/req/states/in/traffic")
+		reqStateOutPacketsMeter   = metrics.NewMeter("eth/req/states/out/packets")
+		reqStateOutTrafficMeter   = metrics.NewMeter("eth/req/states/out/traffic")
+		reqReceiptInPacketsMeter  = metrics.NewMeter("eth/req/receipts/in/packets")
+		reqReceiptInTrafficMeter  = metrics.NewMeter("eth/req/receipts/in/traffic")
+		reqReceiptOutPacketsMeter = metrics.NewMeter("eth/req/receipts/out/packets")
+		reqReceiptOutTrafficMeter = metrics.NewMeter("eth/req/receipts/out/traffic")*/
+	miscInPacketsMeter  = metrics.NewMeter("les/misc/in/packets")
+	miscInTrafficMeter  = metrics.NewMeter("les/misc/in/traffic")
+	miscOutPacketsMeter = metrics.NewMeter("les/misc/out/packets")
+	miscOutTrafficMeter = metrics.NewMeter("les/misc/out/traffic")
+)
+
+// meteredMsgReadWriter is a wrapper around a p2p.MsgReadWriter, capable of
+// accumulating the above defined metrics based on the data stream contents.
+type meteredMsgReadWriter struct {
+	p2p.MsgReadWriter     // Wrapped message stream to meter
+	version           int // Protocol version to select correct meters
+}
+
+// newMeteredMsgWriter wraps a p2p MsgReadWriter with metering support. If the
+// metrics system is disabled, this fucntion returns the original object.
+func newMeteredMsgWriter(rw p2p.MsgReadWriter) p2p.MsgReadWriter {
+	if !metrics.Enabled {
+		return rw
+	}
+	return &meteredMsgReadWriter{MsgReadWriter: rw}
+}
+
+// Init sets the protocol version used by the stream to know which meters to
+// increment in case of overlapping message ids between protocol versions.
+func (rw *meteredMsgReadWriter) Init(version int) {
+	rw.version = version
+}
+
+func (rw *meteredMsgReadWriter) ReadMsg() (p2p.Msg, error) {
+	// Read the message and short circuit in case of an error
+	msg, err := rw.MsgReadWriter.ReadMsg()
+	if err != nil {
+		return msg, err
+	}
+	// Account for the data traffic
+	packets, traffic := miscInPacketsMeter, miscInTrafficMeter
+	packets.Mark(1)
+	traffic.Mark(int64(msg.Size))
+
+	return msg, err
+}
+
+func (rw *meteredMsgReadWriter) WriteMsg(msg p2p.Msg) error {
+	// Account for the data traffic
+	packets, traffic := miscOutPacketsMeter, miscOutTrafficMeter
+	packets.Mark(1)
+	traffic.Mark(int64(msg.Size))
+
+	// Send the packet to the p2p layer
+	return rw.MsgReadWriter.WriteMsg(msg)
+}

les/odr.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+package les
+
+import (
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common/mclock"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/light"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"golang.org/x/net/context"
+)
+
+var (
+	softRequestTimeout = time.Millisecond * 500
+	hardRequestTimeout = time.Second * 10
+	retryPeers         = time.Second * 1
+)
+
+// peerDropFn is a callback type for dropping a peer detected as malicious.
+type peerDropFn func(id string)
+
+type LesOdr struct {
+	light.OdrBackend
+	db           ethdb.Database
+	stop         chan struct{}
+	removePeer   peerDropFn
+	mlock, clock sync.Mutex
+	sentReqs     map[uint64]*sentReq
+	peers        *odrPeerSet
+	lastReqID    uint64
+}
+
+func NewLesOdr(db ethdb.Database) *LesOdr {
+	return &LesOdr{
+		db:       db,
+		stop:     make(chan struct{}),
+		peers:    newOdrPeerSet(),
+		sentReqs: make(map[uint64]*sentReq),
+	}
+}
+
+func (odr *LesOdr) Stop() {
+	close(odr.stop)
+}
+
+func (odr *LesOdr) Database() ethdb.Database {
+	return odr.db
+}
+
+// validatorFunc is a function that processes a message and returns true if
+// it was a meaningful answer to a given request
+type validatorFunc func(ethdb.Database, *Msg) bool
+
+// sentReq is a request waiting for an answer that satisfies its valFunc
+type sentReq struct {
+	valFunc  validatorFunc
+	sentTo   map[*peer]chan struct{}
+	lock     sync.RWMutex  // protects acces to sentTo
+	answered chan struct{} // closed and set to nil when any peer answers it
+}
+
+// RegisterPeer registers a new LES peer to the ODR capable peer set
+func (self *LesOdr) RegisterPeer(p *peer) error {
+	return self.peers.register(p)
+}
+
+// UnregisterPeer removes a peer from the ODR capable peer set
+func (self *LesOdr) UnregisterPeer(p *peer) {
+	self.peers.unregister(p)
+}
+
+const (
+	MsgBlockBodies = iota
+	MsgCode
+	MsgReceipts
+	MsgProofs
+	MsgHeaderProofs
+)
+
+// Msg encodes a LES message that delivers reply data for a request
+type Msg struct {
+	MsgType int
+	ReqID   uint64
+	Obj     interface{}
+}
+
+// Deliver is called by the LES protocol manager to deliver ODR reply messages to waiting requests
+func (self *LesOdr) Deliver(peer *peer, msg *Msg) error {
+	var delivered chan struct{}
+	self.mlock.Lock()
+	req, ok := self.sentReqs[msg.ReqID]
+	self.mlock.Unlock()
+	if ok {
+		req.lock.Lock()
+		delivered, ok = req.sentTo[peer]
+		req.lock.Unlock()
+	}
+
+	if !ok {
+		return errResp(ErrUnexpectedResponse, "reqID = %v", msg.ReqID)
+	}
+
+	if req.valFunc(self.db, msg) {
+		close(delivered)
+		req.lock.Lock()
+		if req.answered != nil {
+			close(req.answered)
+			req.answered = nil
+		}
+		req.lock.Unlock()
+		return nil
+	}
+	return errResp(ErrInvalidResponse, "reqID = %v", msg.ReqID)
+}
+
+func (self *LesOdr) requestPeer(req *sentReq, peer *peer, delivered, timeout chan struct{}, reqWg *sync.WaitGroup) {
+	stime := mclock.Now()
+	defer func() {
+		req.lock.Lock()
+		delete(req.sentTo, peer)
+		req.lock.Unlock()
+		reqWg.Done()
+	}()
+
+	select {
+	case <-delivered:
+		servTime := uint64(mclock.Now() - stime)
+		self.peers.updateTimeout(peer, false)
+		self.peers.updateServTime(peer, servTime)
+		return
+	case <-time.After(softRequestTimeout):
+		close(timeout)
+		if self.peers.updateTimeout(peer, true) {
+			self.removePeer(peer.id)
+		}
+	case <-self.stop:
+		return
+	}
+
+	select {
+	case <-delivered:
+		servTime := uint64(mclock.Now() - stime)
+		self.peers.updateServTime(peer, servTime)
+		return
+	case <-time.After(hardRequestTimeout):
+		self.removePeer(peer.id)
+	case <-self.stop:
+		return
+	}
+}
+
+// networkRequest sends a request to known peers until an answer is received
+// or the context is cancelled
+func (self *LesOdr) networkRequest(ctx context.Context, lreq LesOdrRequest) error {
+	answered := make(chan struct{})
+	req := &sentReq{
+		valFunc:  lreq.Valid,
+		sentTo:   make(map[*peer]chan struct{}),
+		answered: answered, // reply delivered by any peer
+	}
+	reqID := self.getNextReqID()
+	self.mlock.Lock()
+	self.sentReqs[reqID] = req
+	self.mlock.Unlock()
+
+	reqWg := new(sync.WaitGroup)
+	reqWg.Add(1)
+	defer reqWg.Done()
+	go func() {
+		reqWg.Wait()
+		self.mlock.Lock()
+		delete(self.sentReqs, reqID)
+		self.mlock.Unlock()
+	}()
+
+	exclude := make(map[*peer]struct{})
+	for {
+		if peer := self.peers.bestPeer(lreq, exclude); peer == nil {
+			select {
+			case <-ctx.Done():
+				return ctx.Err()
+			case <-req.answered:
+				return nil
+			case <-time.After(retryPeers):
+			}
+		} else {
+			exclude[peer] = struct{}{}
+			delivered := make(chan struct{})
+			timeout := make(chan struct{})
+			req.lock.Lock()
+			req.sentTo[peer] = delivered
+			req.lock.Unlock()
+			reqWg.Add(1)
+			cost := lreq.GetCost(peer)
+			peer.fcServer.SendRequest(reqID, cost)
+			go self.requestPeer(req, peer, delivered, timeout, reqWg)
+			lreq.Request(reqID, peer)
+
+			select {
+			case <-ctx.Done():
+				return ctx.Err()
+			case <-answered:
+				return nil
+			case <-timeout:
+			}
+		}
+	}
+}
+
+// Retrieve tries to fetch an object from the local db, then from the LES network.
+// If the network retrieval was successful, it stores the object in local db.
+func (self *LesOdr) Retrieve(ctx context.Context, req light.OdrRequest) (err error) {
+	lreq := LesRequest(req)
+	err = self.networkRequest(ctx, lreq)
+	if err == nil {
+		// retrieved from network, store in db
+		req.StoreResult(self.db)
+	} else {
+		glog.V(logger.Debug).Infof("networkRequest  err = %v", err)
+	}
+	return
+}
+
+func (self *LesOdr) getNextReqID() uint64 {
+	self.clock.Lock()
+	defer self.clock.Unlock()
+
+	self.lastReqID++
+	return self.lastReqID
+}

les/odr_peerset.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+package les
+
+import (
+	"sync"
+)
+
+const dropTimeoutRatio = 20
+
+type odrPeerInfo struct {
+	reqTimeSum, reqTimeCnt, reqCnt, timeoutCnt uint64
+}
+
+// odrPeerSet represents the collection of active peer participating in the block
+// download procedure.
+type odrPeerSet struct {
+	peers map[*peer]*odrPeerInfo
+	lock  sync.RWMutex
+}
+
+// newPeerSet creates a new peer set top track the active download sources.
+func newOdrPeerSet() *odrPeerSet {
+	return &odrPeerSet{
+		peers: make(map[*peer]*odrPeerInfo),
+	}
+}
+
+// Register injects a new peer into the working set, or returns an error if the
+// peer is already known.
+func (ps *odrPeerSet) register(p *peer) error {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	if _, ok := ps.peers[p]; ok {
+		return errAlreadyRegistered
+	}
+	ps.peers[p] = &odrPeerInfo{}
+	return nil
+}
+
+// Unregister removes a remote peer from the active set, disabling any further
+// actions to/from that particular entity.
+func (ps *odrPeerSet) unregister(p *peer) error {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	if _, ok := ps.peers[p]; !ok {
+		return errNotRegistered
+	}
+	delete(ps.peers, p)
+	return nil
+}
+
+func (ps *odrPeerSet) peerPriority(p *peer, info *odrPeerInfo, req LesOdrRequest) uint64 {
+	tm := p.fcServer.CanSend(req.GetCost(p))
+	if info.reqTimeCnt > 0 {
+		tm += info.reqTimeSum / info.reqTimeCnt
+	}
+	return tm
+}
+
+func (ps *odrPeerSet) bestPeer(req LesOdrRequest, exclude map[*peer]struct{}) *peer {
+	var best *peer
+	var bpv uint64
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	for p, info := range ps.peers {
+		if _, ok := exclude[p]; !ok {
+			pv := ps.peerPriority(p, info, req)
+			if best == nil || pv < bpv {
+				best = p
+				bpv = pv
+			}
+		}
+	}
+	return best
+}
+
+func (ps *odrPeerSet) updateTimeout(p *peer, timeout bool) (drop bool) {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	if info, ok := ps.peers[p]; ok {
+		info.reqCnt++
+		if timeout {
+			// check ratio before increase to allow an extra timeout
+			if info.timeoutCnt*dropTimeoutRatio >= info.reqCnt {
+				return true
+			}
+			info.timeoutCnt++
+		}
+	}
+	return false
+}
+
+func (ps *odrPeerSet) updateServTime(p *peer, servTime uint64) {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	if info, ok := ps.peers[p]; ok {
+		info.reqTimeSum += servTime
+		info.reqTimeCnt++
+	}
+}

les/odr_requests.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package light implements on-demand retrieval capable state and chain objects
+// for the Ethereum Light Client.
+package les
+
+import (
+	"bytes"
+	"encoding/binary"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/light"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+type LesOdrRequest interface {
+	GetCost(*peer) uint64
+	Request(uint64, *peer) error
+	Valid(ethdb.Database, *Msg) bool // if true, keeps the retrieved object
+}
+
+func LesRequest(req light.OdrRequest) LesOdrRequest {
+	switch r := req.(type) {
+	case *light.BlockRequest:
+		return (*BlockRequest)(r)
+	case *light.ReceiptsRequest:
+		return (*ReceiptsRequest)(r)
+	case *light.TrieRequest:
+		return (*TrieRequest)(r)
+	case *light.CodeRequest:
+		return (*CodeRequest)(r)
+	case *light.ChtRequest:
+		return (*ChtRequest)(r)
+	default:
+		return nil
+	}
+}
+
+// BlockRequest is the ODR request type for block bodies
+type BlockRequest light.BlockRequest
+
+// GetCost returns the cost of the given ODR request according to the serving
+// peer's cost table (implementation of LesOdrRequest)
+func (self *BlockRequest) GetCost(peer *peer) uint64 {
+	return peer.GetRequestCost(GetBlockBodiesMsg, 1)
+}
+
+// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
+func (self *BlockRequest) Request(reqID uint64, peer *peer) error {
+	glog.V(logger.Debug).Infof("ODR: requesting body of block %08x from peer %v", self.Hash[:4], peer.id)
+	return peer.RequestBodies(reqID, self.GetCost(peer), []common.Hash{self.Hash})
+}
+
+// Valid processes an ODR request reply message from the LES network
+// returns true and stores results in memory if the message was a valid reply
+// to the request (implementation of LesOdrRequest)
+func (self *BlockRequest) Valid(db ethdb.Database, msg *Msg) bool {
+	glog.V(logger.Debug).Infof("ODR: validating body of block %08x", self.Hash[:4])
+	if msg.MsgType != MsgBlockBodies {
+		glog.V(logger.Debug).Infof("ODR: invalid message type")
+		return false
+	}
+	bodies := msg.Obj.([]*types.Body)
+	if len(bodies) != 1 {
+		glog.V(logger.Debug).Infof("ODR: invalid number of entries: %d", len(bodies))
+		return false
+	}
+	body := bodies[0]
+	header := core.GetHeader(db, self.Hash, self.Number)
+	if header == nil {
+		glog.V(logger.Debug).Infof("ODR: header not found for block %08x", self.Hash[:4])
+		return false
+	}
+	txHash := types.DeriveSha(types.Transactions(body.Transactions))
+	if header.TxHash != txHash {
+		glog.V(logger.Debug).Infof("ODR: header.TxHash %08x does not match received txHash %08x", header.TxHash[:4], txHash[:4])
+		return false
+	}
+	uncleHash := types.CalcUncleHash(body.Uncles)
+	if header.UncleHash != uncleHash {
+		glog.V(logger.Debug).Infof("ODR: header.UncleHash %08x does not match received uncleHash %08x", header.UncleHash[:4], uncleHash[:4])
+		return false
+	}
+	data, err := rlp.EncodeToBytes(body)
+	if err != nil {
+		glog.V(logger.Debug).Infof("ODR: body RLP encode error: %v", err)
+		return false
+	}
+	self.Rlp = data
+	glog.V(logger.Debug).Infof("ODR: validation successful")
+	return true
+}
+
+// ReceiptsRequest is the ODR request type for block receipts by block hash
+type ReceiptsRequest light.ReceiptsRequest
+
+// GetCost returns the cost of the given ODR request according to the serving
+// peer's cost table (implementation of LesOdrRequest)
+func (self *ReceiptsRequest) GetCost(peer *peer) uint64 {
+	return peer.GetRequestCost(GetReceiptsMsg, 1)
+}
+
+// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
+func (self *ReceiptsRequest) Request(reqID uint64, peer *peer) error {
+	glog.V(logger.Debug).Infof("ODR: requesting receipts for block %08x from peer %v", self.Hash[:4], peer.id)
+	return peer.RequestReceipts(reqID, self.GetCost(peer), []common.Hash{self.Hash})
+}
+
+// Valid processes an ODR request reply message from the LES network
+// returns true and stores results in memory if the message was a valid reply
+// to the request (implementation of LesOdrRequest)
+func (self *ReceiptsRequest) Valid(db ethdb.Database, msg *Msg) bool {
+	glog.V(logger.Debug).Infof("ODR: validating receipts for block %08x", self.Hash[:4])
+	if msg.MsgType != MsgReceipts {
+		glog.V(logger.Debug).Infof("ODR: invalid message type")
+		return false
+	}
+	receipts := msg.Obj.([]types.Receipts)
+	if len(receipts) != 1 {
+		glog.V(logger.Debug).Infof("ODR: invalid number of entries: %d", len(receipts))
+		return false
+	}
+	hash := types.DeriveSha(receipts[0])
+	header := core.GetHeader(db, self.Hash, self.Number)
+	if header == nil {
+		glog.V(logger.Debug).Infof("ODR: header not found for block %08x", self.Hash[:4])
+		return false
+	}
+	if !bytes.Equal(header.ReceiptHash[:], hash[:]) {
+		glog.V(logger.Debug).Infof("ODR: header receipts hash %08x does not match calculated RLP hash %08x", header.ReceiptHash[:4], hash[:4])
+		return false
+	}
+	self.Receipts = receipts[0]
+	glog.V(logger.Debug).Infof("ODR: validation successful")
+	return true
+}
+
+type ProofReq struct {
+	BHash       common.Hash
+	AccKey, Key []byte
+	FromLevel   uint
+}
+
+// ODR request type for state/storage trie entries, see LesOdrRequest interface
+type TrieRequest light.TrieRequest
+
+// GetCost returns the cost of the given ODR request according to the serving
+// peer's cost table (implementation of LesOdrRequest)
+func (self *TrieRequest) GetCost(peer *peer) uint64 {
+	return peer.GetRequestCost(GetProofsMsg, 1)
+}
+
+// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
+func (self *TrieRequest) Request(reqID uint64, peer *peer) error {
+	glog.V(logger.Debug).Infof("ODR: requesting trie root %08x key %08x from peer %v", self.Id.Root[:4], self.Key[:4], peer.id)
+	req := &ProofReq{
+		BHash:  self.Id.BlockHash,
+		AccKey: self.Id.AccKey,
+		Key:    self.Key,
+	}
+	return peer.RequestProofs(reqID, self.GetCost(peer), []*ProofReq{req})
+}
+
+// Valid processes an ODR request reply message from the LES network
+// returns true and stores results in memory if the message was a valid reply
+// to the request (implementation of LesOdrRequest)
+func (self *TrieRequest) Valid(db ethdb.Database, msg *Msg) bool {
+	glog.V(logger.Debug).Infof("ODR: validating trie root %08x key %08x", self.Id.Root[:4], self.Key[:4])
+
+	if msg.MsgType != MsgProofs {
+		glog.V(logger.Debug).Infof("ODR: invalid message type")
+		return false
+	}
+	proofs := msg.Obj.([][]rlp.RawValue)
+	if len(proofs) != 1 {
+		glog.V(logger.Debug).Infof("ODR: invalid number of entries: %d", len(proofs))
+		return false
+	}
+	_, err := trie.VerifyProof(self.Id.Root, self.Key, proofs[0])
+	if err != nil {
+		glog.V(logger.Debug).Infof("ODR: merkle proof verification error: %v", err)
+		return false
+	}
+	self.Proof = proofs[0]
+	glog.V(logger.Debug).Infof("ODR: validation successful")
+	return true
+}
+
+type CodeReq struct {
+	BHash  common.Hash
+	AccKey []byte
+}
+
+// ODR request type for node data (used for retrieving contract code), see LesOdrRequest interface
+type CodeRequest light.CodeRequest
+
+// GetCost returns the cost of the given ODR request according to the serving
+// peer's cost table (implementation of LesOdrRequest)
+func (self *CodeRequest) GetCost(peer *peer) uint64 {
+	return peer.GetRequestCost(GetCodeMsg, 1)
+}
+
+// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
+func (self *CodeRequest) Request(reqID uint64, peer *peer) error {
+	glog.V(logger.Debug).Infof("ODR: requesting node data for hash %08x from peer %v", self.Hash[:4], peer.id)
+	req := &CodeReq{
+		BHash:  self.Id.BlockHash,
+		AccKey: self.Id.AccKey,
+	}
+	return peer.RequestCode(reqID, self.GetCost(peer), []*CodeReq{req})
+}
+
+// Valid processes an ODR request reply message from the LES network
+// returns true and stores results in memory if the message was a valid reply
+// to the request (implementation of LesOdrRequest)
+func (self *CodeRequest) Valid(db ethdb.Database, msg *Msg) bool {
+	glog.V(logger.Debug).Infof("ODR: validating node data for hash %08x", self.Hash[:4])
+	if msg.MsgType != MsgCode {
+		glog.V(logger.Debug).Infof("ODR: invalid message type")
+		return false
+	}
+	reply := msg.Obj.([][]byte)
+	if len(reply) != 1 {
+		glog.V(logger.Debug).Infof("ODR: invalid number of entries: %d", len(reply))
+		return false
+	}
+	data := reply[0]
+	hash := crypto.Sha3Hash(data)
+	if !bytes.Equal(self.Hash[:], hash[:]) {
+		glog.V(logger.Debug).Infof("ODR: requested hash %08x does not match received data hash %08x", self.Hash[:4], hash[:4])
+		return false
+	}
+	self.Data = data
+	glog.V(logger.Debug).Infof("ODR: validation successful")
+	return true
+}
+
+type ChtReq struct {
+	ChtNum, BlockNum, FromLevel uint64
+}
+
+type ChtResp struct {
+	Header *types.Header
+	Proof  []rlp.RawValue
+}
+
+// ODR request type for requesting headers by Canonical Hash Trie, see LesOdrRequest interface
+type ChtRequest light.ChtRequest
+
+// GetCost returns the cost of the given ODR request according to the serving
+// peer's cost table (implementation of LesOdrRequest)
+func (self *ChtRequest) GetCost(peer *peer) uint64 {
+	return peer.GetRequestCost(GetHeaderProofsMsg, 1)
+}
+
+// Request sends an ODR request to the LES network (implementation of LesOdrRequest)
+func (self *ChtRequest) Request(reqID uint64, peer *peer) error {
+	glog.V(logger.Debug).Infof("ODR: requesting CHT #%d block #%d from peer %v", self.ChtNum, self.BlockNum, peer.id)
+	req := &ChtReq{
+		ChtNum:   self.ChtNum,
+		BlockNum: self.BlockNum,
+	}
+	return peer.RequestHeaderProofs(reqID, self.GetCost(peer), []*ChtReq{req})
+}
+
+// Valid processes an ODR request reply message from the LES network
+// returns true and stores results in memory if the message was a valid reply
+// to the request (implementation of LesOdrRequest)
+func (self *ChtRequest) Valid(db ethdb.Database, msg *Msg) bool {
+	glog.V(logger.Debug).Infof("ODR: validating CHT #%d block #%d", self.ChtNum, self.BlockNum)
+
+	if msg.MsgType != MsgHeaderProofs {
+		glog.V(logger.Debug).Infof("ODR: invalid message type")
+		return false
+	}
+	proofs := msg.Obj.([]ChtResp)
+	if len(proofs) != 1 {
+		glog.V(logger.Debug).Infof("ODR: invalid number of entries: %d", len(proofs))
+		return false
+	}
+	proof := proofs[0]
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], self.BlockNum)
+	value, err := trie.VerifyProof(self.ChtRoot, encNumber[:], proof.Proof)
+	if err != nil {
+		glog.V(logger.Debug).Infof("ODR: CHT merkle proof verification error: %v", err)
+		return false
+	}
+	var node light.ChtNode
+	if err := rlp.DecodeBytes(value, &node); err != nil {
+		glog.V(logger.Debug).Infof("ODR: error decoding CHT node: %v", err)
+		return false
+	}
+	if node.Hash != proof.Header.Hash() {
+		glog.V(logger.Debug).Infof("ODR: CHT header hash does not match")
+		return false
+	}
+
+	self.Proof = proof.Proof
+	self.Header = proof.Header
+	self.Td = node.Td
+	glog.V(logger.Debug).Infof("ODR: validation successful")
+	return true
+}

les/odr_test.go

+package les
+
+import (
+	"bytes"
+	"math/big"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/light"
+	"github.com/ethereum/go-ethereum/rlp"
+	"golang.org/x/net/context"
+)
+
+type odrTestFn func(ctx context.Context, db ethdb.Database, config *core.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte
+
+func TestOdrGetBlockLes1(t *testing.T) { testOdr(t, 1, 1, odrGetBlock) }
+
+func odrGetBlock(ctx context.Context, db ethdb.Database, config *core.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
+	var block *types.Block
+	if bc != nil {
+		block = bc.GetBlockByHash(bhash)
+	} else {
+		block, _ = lc.GetBlockByHash(ctx, bhash)
+	}
+	if block == nil {
+		return nil
+	}
+	rlp, _ := rlp.EncodeToBytes(block)
+	return rlp
+}
+
+func TestOdrGetReceiptsLes1(t *testing.T) { testOdr(t, 1, 1, odrGetReceipts) }
+
+func odrGetReceipts(ctx context.Context, db ethdb.Database, config *core.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
+	var receipts types.Receipts
+	if bc != nil {
+		receipts = core.GetBlockReceipts(db, bhash, core.GetBlockNumber(db, bhash))
+	} else {
+		receipts, _ = light.GetBlockReceipts(ctx, lc.Odr(), bhash, core.GetBlockNumber(db, bhash))
+	}
+	if receipts == nil {
+		return nil
+	}
+	rlp, _ := rlp.EncodeToBytes(receipts)
+	return rlp
+}
+
+func TestOdrAccountsLes1(t *testing.T) { testOdr(t, 1, 1, odrAccounts) }
+
+func odrAccounts(ctx context.Context, db ethdb.Database, config *core.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
+	dummyAddr := common.HexToAddress("1234567812345678123456781234567812345678")
+	acc := []common.Address{testBankAddress, acc1Addr, acc2Addr, dummyAddr}
+
+	var res []byte
+	for _, addr := range acc {
+		if bc != nil {
+			header := bc.GetHeaderByHash(bhash)
+			st, err := state.New(header.Root, db)
+			if err == nil {
+				bal := st.GetBalance(addr)
+				rlp, _ := rlp.EncodeToBytes(bal)
+				res = append(res, rlp...)
+			}
+		} else {
+			header := lc.GetHeaderByHash(bhash)
+			st := light.NewLightState(light.StateTrieID(header), lc.Odr())
+			bal, err := st.GetBalance(ctx, addr)
+			if err == nil {
+				rlp, _ := rlp.EncodeToBytes(bal)
+				res = append(res, rlp...)
+			}
+		}
+	}
+
+	return res
+}
+
+func TestOdrContractCallLes1(t *testing.T) { testOdr(t, 1, 2, odrContractCall) }
+
+// fullcallmsg is the message type used for call transations.
+type fullcallmsg struct {
+	from          *state.StateObject
+	to            *common.Address
+	gas, gasPrice *big.Int
+	value         *big.Int
+	data          []byte
+}
+
+// accessor boilerplate to implement core.Message
+func (m fullcallmsg) From() (common.Address, error)         { return m.from.Address(), nil }
+func (m fullcallmsg) FromFrontier() (common.Address, error) { return m.from.Address(), nil }
+func (m fullcallmsg) Nonce() uint64                         { return 0 }
+func (m fullcallmsg) CheckNonce() bool                      { return false }
+func (m fullcallmsg) To() *common.Address                   { return m.to }
+func (m fullcallmsg) GasPrice() *big.Int                    { return m.gasPrice }
+func (m fullcallmsg) Gas() *big.Int                         { return m.gas }
+func (m fullcallmsg) Value() *big.Int                       { return m.value }
+func (m fullcallmsg) Data() []byte                          { return m.data }
+
+// callmsg is the message type used for call transations.
+type lightcallmsg struct {
+	from          *light.StateObject
+	to            *common.Address
+	gas, gasPrice *big.Int
+	value         *big.Int
+	data          []byte
+}
+
+// accessor boilerplate to implement core.Message
+func (m lightcallmsg) From() (common.Address, error)         { return m.from.Address(), nil }
+func (m lightcallmsg) FromFrontier() (common.Address, error) { return m.from.Address(), nil }
+func (m lightcallmsg) Nonce() uint64                         { return 0 }
+func (m lightcallmsg) CheckNonce() bool                      { return false }
+func (m lightcallmsg) To() *common.Address                   { return m.to }
+func (m lightcallmsg) GasPrice() *big.Int                    { return m.gasPrice }
+func (m lightcallmsg) Gas() *big.Int                         { return m.gas }
+func (m lightcallmsg) Value() *big.Int                       { return m.value }
+func (m lightcallmsg) Data() []byte                          { return m.data }
+
+func odrContractCall(ctx context.Context, db ethdb.Database, config *core.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte {
+	data := common.Hex2Bytes("60CD26850000000000000000000000000000000000000000000000000000000000000000")
+
+	var res []byte
+	for i := 0; i < 3; i++ {
+		data[35] = byte(i)
+		if bc != nil {
+			header := bc.GetHeaderByHash(bhash)
+			statedb, err := state.New(header.Root, db)
+			if err == nil {
+				from := statedb.GetOrNewStateObject(testBankAddress)
+				from.SetBalance(common.MaxBig)
+
+				msg := fullcallmsg{
+					from:     from,
+					gas:      big.NewInt(100000),
+					gasPrice: big.NewInt(0),
+					value:    big.NewInt(0),
+					data:     data,
+					to:       &testContractAddr,
+				}
+
+				vmenv := core.NewEnv(statedb, config, bc, msg, header, config.VmConfig)
+				gp := new(core.GasPool).AddGas(common.MaxBig)
+				ret, _, _ := core.ApplyMessage(vmenv, msg, gp)
+				res = append(res, ret...)
+			}
+		} else {
+			header := lc.GetHeaderByHash(bhash)
+			state := light.NewLightState(light.StateTrieID(header), lc.Odr())
+			from, err := state.GetOrNewStateObject(ctx, testBankAddress)
+			if err == nil {
+				from.SetBalance(common.MaxBig)
+
+				msg := lightcallmsg{
+					from:     from,
+					gas:      big.NewInt(100000),
+					gasPrice: big.NewInt(0),
+					value:    big.NewInt(0),
+					data:     data,
+					to:       &testContractAddr,
+				}
+
+				vmenv := light.NewEnv(ctx, state, config, lc, msg, header, config.VmConfig)
+				gp := new(core.GasPool).AddGas(common.MaxBig)
+				ret, _, _ := core.ApplyMessage(vmenv, msg, gp)
+				if vmenv.Error() == nil {
+					res = append(res, ret...)
+				}
+			}
+		}
+	}
+	return res
+}
+
+func testOdr(t *testing.T, protocol int, expFail uint64, fn odrTestFn) {
+	// Assemble the test environment
+	pm, db, odr := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	lpm, ldb, odr := newTestProtocolManagerMust(t, true, 0, nil)
+	_, err1, lpeer, err2 := newTestPeerPair("peer", protocol, pm, lpm)
+	select {
+	case <-time.After(time.Millisecond * 100):
+	case err := <-err1:
+		t.Fatalf("peer 1 handshake error: %v", err)
+	case err := <-err2:
+		t.Fatalf("peer 1 handshake error: %v", err)
+	}
+
+	lpm.synchronise(lpeer)
+
+	test := func(expFail uint64) {
+		for i := uint64(0); i <= pm.blockchain.CurrentHeader().GetNumberU64(); i++ {
+			bhash := core.GetCanonicalHash(db, i)
+			b1 := fn(light.NoOdr, db, pm.chainConfig, pm.blockchain.(*core.BlockChain), nil, bhash)
+			ctx, _ := context.WithTimeout(context.Background(), 200*time.Millisecond)
+			b2 := fn(ctx, ldb, lpm.chainConfig, nil, lpm.blockchain.(*light.LightChain), bhash)
+			eq := bytes.Equal(b1, b2)
+			exp := i < expFail
+			if exp && !eq {
+				t.Errorf("odr mismatch")
+			}
+			if !exp && eq {
+				t.Errorf("unexpected odr match")
+			}
+		}
+	}
+
+	// temporarily remove peer to test odr fails
+	odr.UnregisterPeer(lpeer)
+	// expect retrievals to fail (except genesis block) without a les peer
+	test(expFail)
+	odr.RegisterPeer(lpeer)
+	// expect all retrievals to pass
+	test(5)
+	odr.UnregisterPeer(lpeer)
+	// still expect all retrievals to pass, now data should be cached locally
+	test(5)
+}

les/peer.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package les implements the Light Ethereum Subprotocol.
+package les
+
+import (
+	"errors"
+	"fmt"
+	"math/big"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/les/flowcontrol"
+	"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"
+)
+
+var (
+	errClosed            = errors.New("peer set is closed")
+	errAlreadyRegistered = errors.New("peer is already registered")
+	errNotRegistered     = errors.New("peer is not registered")
+)
+
+const maxHeadInfoLen = 20
+
+type peer struct {
+	*p2p.Peer
+
+	rw p2p.MsgReadWriter
+
+	version int // Protocol version negotiated
+	network int // Network ID being on
+
+	id string
+
+	firstHeadInfo, headInfo *announceData
+	headInfoLen             int
+	lock                    sync.RWMutex
+
+	announceChn chan announceData
+
+	fcClient       *flowcontrol.ClientNode // nil if the peer is server only
+	fcServer       *flowcontrol.ServerNode // nil if the peer is client only
+	fcServerParams *flowcontrol.ServerParams
+	fcCosts        requestCostTable
+}
+
+func newPeer(version, network int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
+	id := p.ID()
+
+	return &peer{
+		Peer:        p,
+		rw:          rw,
+		version:     version,
+		network:     network,
+		id:          fmt.Sprintf("%x", id[:8]),
+		announceChn: make(chan announceData, 20),
+	}
+}
+
+// Info gathers and returns a collection of metadata known about a peer.
+func (p *peer) Info() *eth.PeerInfo {
+	return &eth.PeerInfo{
+		Version:    p.version,
+		Difficulty: p.Td(),
+		Head:       fmt.Sprintf("%x", p.Head()),
+	}
+}
+
+// Head retrieves a copy of the current head (most recent) hash of the peer.
+func (p *peer) Head() (hash common.Hash) {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+
+	copy(hash[:], p.headInfo.Hash[:])
+	return hash
+}
+
+func (p *peer) HeadAndTd() (hash common.Hash, td *big.Int) {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+
+	copy(hash[:], p.headInfo.Hash[:])
+	return hash, p.headInfo.Td
+}
+
+func (p *peer) headBlockInfo() blockInfo {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+
+	return blockInfo{Hash: p.headInfo.Hash, Number: p.headInfo.Number, Td: p.headInfo.Td}
+}
+
+func (p *peer) addNotify(announce *announceData) bool {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	if announce.Td.Cmp(p.headInfo.Td) < 1 {
+		return false
+	}
+	if p.headInfoLen >= maxHeadInfoLen {
+		//return false
+		p.firstHeadInfo = p.firstHeadInfo.next
+		p.headInfoLen--
+	}
+	if announce.haveHeaders == 0 {
+		hh := p.headInfo.Number - announce.ReorgDepth
+		if p.headInfo.haveHeaders < hh {
+			hh = p.headInfo.haveHeaders
+		}
+		announce.haveHeaders = hh
+	}
+	p.headInfo.next = announce
+	p.headInfo = announce
+	p.headInfoLen++
+	return true
+}
+
+func (p *peer) gotHeader(hash common.Hash, number uint64, td *big.Int) bool {
+	h := p.firstHeadInfo
+	ptr := 0
+	for h != nil {
+		if h.Hash == hash {
+			if h.Number != number || h.Td.Cmp(td) != 0 {
+				return false
+			}
+			h.headKnown = true
+			h.haveHeaders = h.Number
+			p.firstHeadInfo = h
+			p.headInfoLen -= ptr
+			last := h
+			h = h.next
+			// propagate haveHeaders through the chain
+			for h != nil {
+				hh := last.Number - h.ReorgDepth
+				if last.haveHeaders < hh {
+					hh = last.haveHeaders
+				}
+				if hh > h.haveHeaders {
+					h.haveHeaders = hh
+				} else {
+					return true
+				}
+				last = h
+				h = h.next
+			}
+			return true
+		}
+		h = h.next
+		ptr++
+	}
+	return true
+}
+
+// Td retrieves the current total difficulty of a peer.
+func (p *peer) Td() *big.Int {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+
+	return new(big.Int).Set(p.headInfo.Td)
+}
+
+func sendRequest(w p2p.MsgWriter, msgcode, reqID, cost uint64, data interface{}) error {
+	type req struct {
+		ReqID uint64
+		Data  interface{}
+	}
+	return p2p.Send(w, msgcode, req{reqID, data})
+}
+
+func sendResponse(w p2p.MsgWriter, msgcode, reqID, bv uint64, data interface{}) error {
+	type resp struct {
+		ReqID, BV uint64
+		Data      interface{}
+	}
+	return p2p.Send(w, msgcode, resp{reqID, bv, data})
+}
+
+func (p *peer) GetRequestCost(msgcode uint64, amount int) uint64 {
+	cost := p.fcCosts[msgcode].baseCost + p.fcCosts[msgcode].reqCost*uint64(amount)
+	if cost > p.fcServerParams.BufLimit {
+		cost = p.fcServerParams.BufLimit
+	}
+	return cost
+}
+
+// SendAnnounce announces the availability of a number of blocks through
+// a hash notification.
+func (p *peer) SendAnnounce(request announceData) error {
+	return p2p.Send(p.rw, AnnounceMsg, request)
+}
+
+// SendBlockHeaders sends a batch of block headers to the remote peer.
+func (p *peer) SendBlockHeaders(reqID, bv uint64, headers []*types.Header) error {
+	return sendResponse(p.rw, BlockHeadersMsg, reqID, bv, headers)
+}
+
+// SendBlockBodiesRLP sends a batch of block contents to the remote peer from
+// an already RLP encoded format.
+func (p *peer) SendBlockBodiesRLP(reqID, bv uint64, bodies []rlp.RawValue) error {
+	return sendResponse(p.rw, BlockBodiesMsg, reqID, bv, bodies)
+}
+
+// SendCodeRLP sends a batch of arbitrary internal data, corresponding to the
+// hashes requested.
+func (p *peer) SendCode(reqID, bv uint64, data [][]byte) error {
+	return sendResponse(p.rw, CodeMsg, reqID, bv, data)
+}
+
+// SendReceiptsRLP sends a batch of transaction receipts, corresponding to the
+// ones requested from an already RLP encoded format.
+func (p *peer) SendReceiptsRLP(reqID, bv uint64, receipts []rlp.RawValue) error {
+	return sendResponse(p.rw, ReceiptsMsg, reqID, bv, receipts)
+}
+
+// SendProofs sends a batch of merkle proofs, corresponding to the ones requested.
+func (p *peer) SendProofs(reqID, bv uint64, proofs proofsData) error {
+	return sendResponse(p.rw, ProofsMsg, reqID, bv, proofs)
+}
+
+// SendHeaderProofs sends a batch of header proofs, corresponding to the ones requested.
+func (p *peer) SendHeaderProofs(reqID, bv uint64, proofs []ChtResp) error {
+	return sendResponse(p.rw, HeaderProofsMsg, reqID, bv, proofs)
+}
+
+// RequestHeadersByHash fetches a batch of blocks' headers corresponding to the
+// specified header query, based on the hash of an origin block.
+func (p *peer) RequestHeadersByHash(reqID, cost uint64, origin common.Hash, amount int, skip int, reverse bool) error {
+	glog.V(logger.Debug).Infof("%v fetching %d headers from %x, skipping %d (reverse = %v)", p, amount, origin[:4], skip, reverse)
+	return sendRequest(p.rw, GetBlockHeadersMsg, reqID, cost, &getBlockHeadersData{Origin: hashOrNumber{Hash: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
+}
+
+// RequestHeadersByNumber fetches a batch of blocks' headers corresponding to the
+// specified header query, based on the number of an origin block.
+func (p *peer) RequestHeadersByNumber(reqID, cost, origin uint64, amount int, skip int, reverse bool) error {
+	glog.V(logger.Debug).Infof("%v fetching %d headers from #%d, skipping %d (reverse = %v)", p, amount, origin, skip, reverse)
+	return sendRequest(p.rw, GetBlockHeadersMsg, reqID, cost, &getBlockHeadersData{Origin: hashOrNumber{Number: origin}, Amount: uint64(amount), Skip: uint64(skip), Reverse: reverse})
+}
+
+// RequestBodies fetches a batch of blocks' bodies corresponding to the hashes
+// specified.
+func (p *peer) RequestBodies(reqID, cost uint64, hashes []common.Hash) error {
+	glog.V(logger.Debug).Infof("%v fetching %d block bodies", p, len(hashes))
+	return sendRequest(p.rw, GetBlockBodiesMsg, reqID, cost, hashes)
+}
+
+// RequestCode fetches a batch of arbitrary data from a node's known state
+// data, corresponding to the specified hashes.
+func (p *peer) RequestCode(reqID, cost uint64, reqs []*CodeReq) error {
+	glog.V(logger.Debug).Infof("%v fetching %v state data", p, len(reqs))
+	return sendRequest(p.rw, GetCodeMsg, reqID, cost, reqs)
+}
+
+// RequestReceipts fetches a batch of transaction receipts from a remote node.
+func (p *peer) RequestReceipts(reqID, cost uint64, hashes []common.Hash) error {
+	glog.V(logger.Debug).Infof("%v fetching %v receipts", p, len(hashes))
+	return sendRequest(p.rw, GetReceiptsMsg, reqID, cost, hashes)
+}
+
+// RequestProofs fetches a batch of merkle proofs from a remote node.
+func (p *peer) RequestProofs(reqID, cost uint64, reqs []*ProofReq) error {
+	glog.V(logger.Debug).Infof("%v fetching %v proofs", p, len(reqs))
+	return sendRequest(p.rw, GetProofsMsg, reqID, cost, reqs)
+}
+
+// RequestHeaderProofs fetches a batch of header merkle proofs from a remote node.
+func (p *peer) RequestHeaderProofs(reqID, cost uint64, reqs []*ChtReq) error {
+	glog.V(logger.Debug).Infof("%v fetching %v header proofs", p, len(reqs))
+	return sendRequest(p.rw, GetHeaderProofsMsg, reqID, cost, reqs)
+}
+
+func (p *peer) SendTxs(cost uint64, txs types.Transactions) error {
+	glog.V(logger.Debug).Infof("%v relaying %v txs", p, len(txs))
+	p.fcServer.SendRequest(0, cost)
+	return p2p.Send(p.rw, SendTxMsg, txs)
+}
+
+type keyValueEntry struct {
+	Key   string
+	Value rlp.RawValue
+}
+type keyValueList []keyValueEntry
+type keyValueMap map[string]rlp.RawValue
+
+func (l keyValueList) add(key string, val interface{}) keyValueList {
+	var entry keyValueEntry
+	entry.Key = key
+	if val == nil {
+		val = uint64(0)
+	}
+	enc, err := rlp.EncodeToBytes(val)
+	if err == nil {
+		entry.Value = enc
+	}
+	return append(l, entry)
+}
+
+func (l keyValueList) decode() keyValueMap {
+	m := make(keyValueMap)
+	for _, entry := range l {
+		m[entry.Key] = entry.Value
+	}
+	return m
+}
+
+func (m keyValueMap) get(key string, val interface{}) error {
+	enc, ok := m[key]
+	if !ok {
+		return errResp(ErrHandshakeMissingKey, "%s", key)
+	}
+	if val == nil {
+		return nil
+	}
+	return rlp.DecodeBytes(enc, val)
+}
+
+func (p *peer) sendReceiveHandshake(sendList keyValueList) (keyValueList, error) {
+	// Send out own handshake in a new thread
+	errc := make(chan error, 1)
+	go func() {
+		errc <- p2p.Send(p.rw, StatusMsg, sendList)
+	}()
+	// In the mean time retrieve the remote status message
+	msg, err := p.rw.ReadMsg()
+	if err != nil {
+		return nil, err
+	}
+	if msg.Code != StatusMsg {
+		return nil, errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
+	}
+	if msg.Size > ProtocolMaxMsgSize {
+		return nil, errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
+	}
+	// Decode the handshake
+	var recvList keyValueList
+	if err := msg.Decode(&recvList); err != nil {
+		return nil, errResp(ErrDecode, "msg %v: %v", msg, err)
+	}
+	if err := <-errc; err != nil {
+		return nil, err
+	}
+	return recvList, nil
+}
+
+// Handshake executes the les protocol handshake, negotiating version number,
+// network IDs, difficulties, head and genesis blocks.
+func (p *peer) Handshake(td *big.Int, head common.Hash, headNum uint64, genesis common.Hash, server *LesServer) error {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	var send keyValueList
+	send = send.add("protocolVersion", uint64(p.version))
+	send = send.add("networkId", uint64(p.network))
+	send = send.add("headTd", td)
+	send = send.add("headHash", head)
+	send = send.add("headNum", headNum)
+	send = send.add("genesisHash", genesis)
+	if server != nil {
+		send = send.add("serveHeaders", nil)
+		send = send.add("serveChainSince", uint64(0))
+		send = send.add("serveStateSince", uint64(0))
+		send = send.add("txRelay", nil)
+		send = send.add("flowControl/BL", server.defParams.BufLimit)
+		send = send.add("flowControl/MRR", server.defParams.MinRecharge)
+		list := server.fcCostStats.getCurrentList()
+		send = send.add("flowControl/MRC", list)
+		p.fcCosts = list.decode()
+	}
+	recvList, err := p.sendReceiveHandshake(send)
+	if err != nil {
+		return err
+	}
+	recv := recvList.decode()
+
+	var rGenesis, rHash common.Hash
+	var rVersion, rNetwork, rNum uint64
+	var rTd *big.Int
+
+	if err := recv.get("protocolVersion", &rVersion); err != nil {
+		return err
+	}
+	if err := recv.get("networkId", &rNetwork); err != nil {
+		return err
+	}
+	if err := recv.get("headTd", &rTd); err != nil {
+		return err
+	}
+	if err := recv.get("headHash", &rHash); err != nil {
+		return err
+	}
+	if err := recv.get("headNum", &rNum); err != nil {
+		return err
+	}
+	if err := recv.get("genesisHash", &rGenesis); err != nil {
+		return err
+	}
+
+	if rGenesis != genesis {
+		return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", rGenesis, genesis)
+	}
+	if int(rNetwork) != p.network {
+		return errResp(ErrNetworkIdMismatch, "%d (!= %d)", rNetwork, p.network)
+	}
+	if int(rVersion) != p.version {
+		return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", rVersion, p.version)
+	}
+	if server != nil {
+		if recv.get("serveStateSince", nil) == nil {
+			return errResp(ErrUselessPeer, "wanted client, got server")
+		}
+		p.fcClient = flowcontrol.NewClientNode(server.fcManager, server.defParams)
+	} else {
+		if recv.get("serveChainSince", nil) != nil {
+			return errResp(ErrUselessPeer, "peer cannot serve chain")
+		}
+		if recv.get("serveStateSince", nil) != nil {
+			return errResp(ErrUselessPeer, "peer cannot serve state")
+		}
+		if recv.get("txRelay", nil) != nil {
+			return errResp(ErrUselessPeer, "peer cannot relay transactions")
+		}
+		params := &flowcontrol.ServerParams{}
+		if err := recv.get("flowControl/BL", &params.BufLimit); err != nil {
+			return err
+		}
+		if err := recv.get("flowControl/MRR", &params.MinRecharge); err != nil {
+			return err
+		}
+		var MRC RequestCostList
+		if err := recv.get("flowControl/MRC", &MRC); err != nil {
+			return err
+		}
+		p.fcServerParams = params
+		p.fcServer = flowcontrol.NewServerNode(params)
+		p.fcCosts = MRC.decode()
+	}
+
+	p.firstHeadInfo = &announceData{Td: rTd, Hash: rHash, Number: rNum}
+	p.headInfo = p.firstHeadInfo
+	p.headInfoLen = 1
+	return nil
+}
+
+// String implements fmt.Stringer.
+func (p *peer) String() string {
+	return fmt.Sprintf("Peer %s [%s]", p.id,
+		fmt.Sprintf("les/%d", p.version),
+	)
+}
+
+// peerSet represents the collection of active peers currently participating in
+// the Light Ethereum sub-protocol.
+type peerSet struct {
+	peers  map[string]*peer
+	lock   sync.RWMutex
+	closed bool
+}
+
+// newPeerSet creates a new peer set to track the active participants.
+func newPeerSet() *peerSet {
+	return &peerSet{
+		peers: make(map[string]*peer),
+	}
+}
+
+// Register injects a new peer into the working set, or returns an error if the
+// peer is already known.
+func (ps *peerSet) Register(p *peer) error {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	if ps.closed {
+		return errClosed
+	}
+	if _, ok := ps.peers[p.id]; ok {
+		return errAlreadyRegistered
+	}
+	ps.peers[p.id] = p
+	return nil
+}
+
+// Unregister removes a remote peer from the active set, disabling any further
+// actions to/from that particular entity.
+func (ps *peerSet) Unregister(id string) error {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	if _, ok := ps.peers[id]; !ok {
+		return errNotRegistered
+	}
+	delete(ps.peers, id)
+	return nil
+}
+
+// AllPeerIDs returns a list of all registered peer IDs
+func (ps *peerSet) AllPeerIDs() []string {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	res := make([]string, len(ps.peers))
+	idx := 0
+	for id, _ := range ps.peers {
+		res[idx] = id
+		idx++
+	}
+	return res
+}
+
+// Peer retrieves the registered peer with the given id.
+func (ps *peerSet) Peer(id string) *peer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	return ps.peers[id]
+}
+
+// Len returns if the current number of peers in the set.
+func (ps *peerSet) Len() int {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	return len(ps.peers)
+}
+
+// BestPeer retrieves the known peer with the currently highest total difficulty.
+func (ps *peerSet) BestPeer() *peer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	var (
+		bestPeer *peer
+		bestTd   *big.Int
+	)
+	for _, p := range ps.peers {
+		if td := p.Td(); bestPeer == nil || td.Cmp(bestTd) > 0 {
+			bestPeer, bestTd = p, td
+		}
+	}
+	return bestPeer
+}
+
+// AllPeers returns all peers in a list
+func (ps *peerSet) AllPeers() []*peer {
+	ps.lock.RLock()
+	defer ps.lock.RUnlock()
+
+	list := make([]*peer, len(ps.peers))
+	i := 0
+	for _, peer := range ps.peers {
+		list[i] = peer
+		i++
+	}
+	return list
+}
+
+// Close disconnects all peers.
+// No new peers can be registered after Close has returned.
+func (ps *peerSet) Close() {
+	ps.lock.Lock()
+	defer ps.lock.Unlock()
+
+	for _, p := range ps.peers {
+		p.Disconnect(p2p.DiscQuitting)
+	}
+	ps.closed = true
+}

les/protocol.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package les implements the Light Ethereum Subprotocol.
+package les
+
+import (
+	"fmt"
+	"io"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+// Constants to match up protocol versions and messages
+const (
+	lpv1 = 1
+)
+
+// Supported versions of the les protocol (first is primary).
+var ProtocolVersions = []uint{lpv1}
+
+// Number of implemented message corresponding to different protocol versions.
+var ProtocolLengths = []uint64{15}
+
+const (
+	NetworkId          = 1
+	ProtocolMaxMsgSize = 10 * 1024 * 1024 // Maximum cap on the size of a protocol message
+)
+
+// les protocol message codes
+const (
+	// Protocol messages belonging to LPV1
+	StatusMsg          = 0x00
+	AnnounceMsg        = 0x01
+	GetBlockHeadersMsg = 0x02
+	BlockHeadersMsg    = 0x03
+	GetBlockBodiesMsg  = 0x04
+	BlockBodiesMsg     = 0x05
+	GetReceiptsMsg     = 0x06
+	ReceiptsMsg        = 0x07
+	GetProofsMsg       = 0x08
+	ProofsMsg          = 0x09
+	GetCodeMsg         = 0x0a
+	CodeMsg            = 0x0b
+	SendTxMsg          = 0x0c
+	GetHeaderProofsMsg = 0x0d
+	HeaderProofsMsg    = 0x0e
+)
+
+type errCode int
+
+const (
+	ErrMsgTooLarge = iota
+	ErrDecode
+	ErrInvalidMsgCode
+	ErrProtocolVersionMismatch
+	ErrNetworkIdMismatch
+	ErrGenesisBlockMismatch
+	ErrNoStatusMsg
+	ErrExtraStatusMsg
+	ErrSuspendedPeer
+	ErrUselessPeer
+	ErrRequestRejected
+	ErrUnexpectedResponse
+	ErrInvalidResponse
+	ErrTooManyTimeouts
+	ErrHandshakeMissingKey
+)
+
+func (e errCode) String() string {
+	return errorToString[int(e)]
+}
+
+// XXX change once legacy code is out
+var errorToString = map[int]string{
+	ErrMsgTooLarge:             "Message too long",
+	ErrDecode:                  "Invalid message",
+	ErrInvalidMsgCode:          "Invalid message code",
+	ErrProtocolVersionMismatch: "Protocol version mismatch",
+	ErrNetworkIdMismatch:       "NetworkId mismatch",
+	ErrGenesisBlockMismatch:    "Genesis block mismatch",
+	ErrNoStatusMsg:             "No status message",
+	ErrExtraStatusMsg:          "Extra status message",
+	ErrSuspendedPeer:           "Suspended peer",
+	ErrRequestRejected:         "Request rejected",
+	ErrUnexpectedResponse:      "Unexpected response",
+	ErrInvalidResponse:         "Invalid response",
+	ErrTooManyTimeouts:         "Too many request timeouts",
+	ErrHandshakeMissingKey:     "Key missing from handshake message",
+}
+
+type chainManager interface {
+	GetBlockHashesFromHash(hash common.Hash, amount uint64) (hashes []common.Hash)
+	GetBlock(hash common.Hash) (block *types.Block)
+	Status() (td *big.Int, currentBlock common.Hash, genesisBlock common.Hash)
+}
+
+// announceData is the network packet for the block announcements.
+type announceData struct {
+	Hash       common.Hash // Hash of one particular block being announced
+	Number     uint64      // Number of one particular block being announced
+	Td         *big.Int    // Total difficulty of one particular block being announced
+	ReorgDepth uint64
+	Update     keyValueList
+
+	haveHeaders uint64 // we have the headers of the remote peer's chain up to this number
+	headKnown   bool
+	requested   bool
+	next        *announceData
+}
+
+type blockInfo struct {
+	Hash   common.Hash // Hash of one particular block being announced
+	Number uint64      // Number of one particular block being announced
+	Td     *big.Int    // Total difficulty of one particular block being announced
+}
+
+// getBlockHashesData is the network packet for the hash based hash retrieval.
+type getBlockHashesData struct {
+	Hash   common.Hash
+	Amount uint64
+}
+
+// getBlockHeadersData represents a block header query.
+type getBlockHeadersData struct {
+	Origin  hashOrNumber // Block from which to retrieve headers
+	Amount  uint64       // Maximum number of headers to retrieve
+	Skip    uint64       // Blocks to skip between consecutive headers
+	Reverse bool         // Query direction (false = rising towards latest, true = falling towards genesis)
+}
+
+// hashOrNumber is a combined field for specifying an origin block.
+type hashOrNumber struct {
+	Hash   common.Hash // Block hash from which to retrieve headers (excludes Number)
+	Number uint64      // Block hash from which to retrieve headers (excludes Hash)
+}
+
+// EncodeRLP is a specialized encoder for hashOrNumber to encode only one of the
+// two contained union fields.
+func (hn *hashOrNumber) EncodeRLP(w io.Writer) error {
+	if hn.Hash == (common.Hash{}) {
+		return rlp.Encode(w, hn.Number)
+	}
+	if hn.Number != 0 {
+		return fmt.Errorf("both origin hash (%x) and number (%d) provided", hn.Hash, hn.Number)
+	}
+	return rlp.Encode(w, hn.Hash)
+}
+
+// DecodeRLP is a specialized decoder for hashOrNumber to decode the contents
+// into either a block hash or a block number.
+func (hn *hashOrNumber) DecodeRLP(s *rlp.Stream) error {
+	_, size, _ := s.Kind()
+	origin, err := s.Raw()
+	if err == nil {
+		switch {
+		case size == 32:
+			err = rlp.DecodeBytes(origin, &hn.Hash)
+		case size <= 8:
+			err = rlp.DecodeBytes(origin, &hn.Number)
+		default:
+			err = fmt.Errorf("invalid input size %d for origin", size)
+		}
+	}
+	return err
+}
+
+// newBlockData is the network packet for the block propagation message.
+type newBlockData struct {
+	Block *types.Block
+	TD    *big.Int
+}
+
+// blockBodiesData is the network packet for block content distribution.
+type blockBodiesData []*types.Body
+
+// CodeData is the network response packet for a node data retrieval.
+type CodeData []struct {
+	Value []byte
+}
+
+type proofsData [][]rlp.RawValue

les/request_test.go

+package les
+
+import (
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/light"
+	"golang.org/x/net/context"
+)
+
+var testBankSecureTrieKey = secAddr(testBankAddress)
+
+func secAddr(addr common.Address) []byte {
+	return crypto.Keccak256(addr[:])
+}
+
+type accessTestFn func(db ethdb.Database, bhash common.Hash, number uint64) light.OdrRequest
+
+func TestBlockAccessLes1(t *testing.T) { testAccess(t, 1, tfBlockAccess) }
+
+func tfBlockAccess(db ethdb.Database, bhash common.Hash, number uint64) light.OdrRequest {
+	return &light.BlockRequest{Hash: bhash, Number: number}
+}
+
+func TestReceiptsAccessLes1(t *testing.T) { testAccess(t, 1, tfReceiptsAccess) }
+
+func tfReceiptsAccess(db ethdb.Database, bhash common.Hash, number uint64) light.OdrRequest {
+	return &light.ReceiptsRequest{Hash: bhash, Number: number}
+}
+
+func TestTrieEntryAccessLes1(t *testing.T) { testAccess(t, 1, tfTrieEntryAccess) }
+
+func tfTrieEntryAccess(db ethdb.Database, bhash common.Hash, number uint64) light.OdrRequest {
+	return &light.TrieRequest{Id: light.StateTrieID(core.GetHeader(db, bhash, core.GetBlockNumber(db, bhash))), Key: testBankSecureTrieKey}
+}
+
+func TestCodeAccessLes1(t *testing.T) { testAccess(t, 1, tfCodeAccess) }
+
+func tfCodeAccess(db ethdb.Database, bhash common.Hash, number uint64) light.OdrRequest {
+	header := core.GetHeader(db, bhash, core.GetBlockNumber(db, bhash))
+	if header.GetNumberU64() < testContractDeployed {
+		return nil
+	}
+	sti := light.StateTrieID(header)
+	ci := light.StorageTrieID(sti, testContractAddr, common.Hash{})
+	return &light.CodeRequest{Id: ci, Hash: crypto.Keccak256Hash(testContractCodeDeployed)}
+}
+
+func testAccess(t *testing.T, protocol int, fn accessTestFn) {
+	// Assemble the test environment
+	pm, db, _ := newTestProtocolManagerMust(t, false, 4, testChainGen)
+	lpm, ldb, odr := newTestProtocolManagerMust(t, true, 0, nil)
+	_, err1, lpeer, err2 := newTestPeerPair("peer", protocol, pm, lpm)
+	select {
+	case <-time.After(time.Millisecond * 100):
+	case err := <-err1:
+		t.Fatalf("peer 1 handshake error: %v", err)
+	case err := <-err2:
+		t.Fatalf("peer 1 handshake error: %v", err)
+	}
+
+	lpm.synchronise(lpeer)
+
+	test := func(expFail uint64) {
+		for i := uint64(0); i <= pm.blockchain.CurrentHeader().GetNumberU64(); i++ {
+			bhash := core.GetCanonicalHash(db, i)
+			if req := fn(ldb, bhash, i); req != nil {
+				ctx, _ := context.WithTimeout(context.Background(), 200*time.Millisecond)
+				err := odr.Retrieve(ctx, req)
+				got := err == nil
+				exp := i < expFail
+				if exp && !got {
+					t.Errorf("object retrieval failed")
+				}
+				if !exp && got {
+					t.Errorf("unexpected object retrieval success")
+				}
+			}
+		}
+	}
+
+	// temporarily remove peer to test odr fails
+	odr.UnregisterPeer(lpeer)
+	// expect retrievals to fail (except genesis block) without a les peer
+	test(0)
+	odr.RegisterPeer(lpeer)
+	// expect all retrievals to pass
+	test(5)
+	odr.UnregisterPeer(lpeer)
+}

les/server.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package les implements the Light Ethereum Subprotocol.
+package les
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math"
+	"sync"
+	"time"
+
+	"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"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/les/flowcontrol"
+	"github.com/ethereum/go-ethereum/light"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+)
+
+type LesServer struct {
+	protocolManager *ProtocolManager
+	fcManager       *flowcontrol.ClientManager // nil if our node is client only
+	fcCostStats     *requestCostStats
+	defParams       *flowcontrol.ServerParams
+}
+
+func NewLesServer(eth *eth.Ethereum, config *eth.Config) (*LesServer, error) {
+	pm, err := NewProtocolManager(config.ChainConfig, false, config.NetworkId, eth.EventMux(), eth.Pow(), eth.BlockChain(), eth.TxPool(), eth.ChainDb(), nil, nil)
+	if err != nil {
+		return nil, err
+	}
+	pm.blockLoop()
+
+	srv := &LesServer{protocolManager: pm}
+	pm.server = srv
+
+	srv.defParams = &flowcontrol.ServerParams{
+		BufLimit:    300000000,
+		MinRecharge: 50000,
+	}
+	srv.fcManager = flowcontrol.NewClientManager(uint64(config.LightServ), 10, 1000000000)
+	srv.fcCostStats = newCostStats(eth.ChainDb())
+	return srv, nil
+}
+
+func (s *LesServer) Protocols() []p2p.Protocol {
+	return s.protocolManager.SubProtocols
+}
+
+func (s *LesServer) Start() {
+	s.protocolManager.Start()
+}
+
+func (s *LesServer) Stop() {
+	s.fcCostStats.store()
+	s.fcManager.Stop()
+	go func() {
+		<-s.protocolManager.noMorePeers
+	}()
+	s.protocolManager.Stop()
+}
+
+type requestCosts struct {
+	baseCost, reqCost uint64
+}
+
+type requestCostTable map[uint64]*requestCosts
+
+type RequestCostList []struct {
+	MsgCode, BaseCost, ReqCost uint64
+}
+
+func (list RequestCostList) decode() requestCostTable {
+	table := make(requestCostTable)
+	for _, e := range list {
+		table[e.MsgCode] = &requestCosts{
+			baseCost: e.BaseCost,
+			reqCost:  e.ReqCost,
+		}
+	}
+	return table
+}
+
+func (table requestCostTable) encode() RequestCostList {
+	list := make(RequestCostList, len(table))
+	for idx, code := range reqList {
+		list[idx].MsgCode = code
+		list[idx].BaseCost = table[code].baseCost
+		list[idx].ReqCost = table[code].reqCost
+	}
+	return list
+}
+
+type linReg struct {
+	sumX, sumY, sumXX, sumXY float64
+	cnt                      uint64
+}
+
+const linRegMaxCnt = 100000
+
+func (l *linReg) add(x, y float64) {
+	if l.cnt >= linRegMaxCnt {
+		sub := float64(l.cnt+1-linRegMaxCnt) / linRegMaxCnt
+		l.sumX -= l.sumX * sub
+		l.sumY -= l.sumY * sub
+		l.sumXX -= l.sumXX * sub
+		l.sumXY -= l.sumXY * sub
+		l.cnt = linRegMaxCnt - 1
+	}
+	l.cnt++
+	l.sumX += x
+	l.sumY += y
+	l.sumXX += x * x
+	l.sumXY += x * y
+}
+
+func (l *linReg) calc() (b, m float64) {
+	if l.cnt == 0 {
+		return 0, 0
+	}
+	cnt := float64(l.cnt)
+	d := cnt*l.sumXX - l.sumX*l.sumX
+	if d < 0.001 {
+		return l.sumY / cnt, 0
+	}
+	m = (cnt*l.sumXY - l.sumX*l.sumY) / d
+	b = (l.sumY / cnt) - (m * l.sumX / cnt)
+	return b, m
+}
+
+func (l *linReg) toBytes() []byte {
+	var arr [40]byte
+	binary.BigEndian.PutUint64(arr[0:8], math.Float64bits(l.sumX))
+	binary.BigEndian.PutUint64(arr[8:16], math.Float64bits(l.sumY))
+	binary.BigEndian.PutUint64(arr[16:24], math.Float64bits(l.sumXX))
+	binary.BigEndian.PutUint64(arr[24:32], math.Float64bits(l.sumXY))
+	binary.BigEndian.PutUint64(arr[32:40], l.cnt)
+	return arr[:]
+}
+
+func linRegFromBytes(data []byte) *linReg {
+	if len(data) != 40 {
+		return nil
+	}
+	l := &linReg{}
+	l.sumX = math.Float64frombits(binary.BigEndian.Uint64(data[0:8]))
+	l.sumY = math.Float64frombits(binary.BigEndian.Uint64(data[8:16]))
+	l.sumXX = math.Float64frombits(binary.BigEndian.Uint64(data[16:24]))
+	l.sumXY = math.Float64frombits(binary.BigEndian.Uint64(data[24:32]))
+	l.cnt = binary.BigEndian.Uint64(data[32:40])
+	return l
+}
+
+type requestCostStats struct {
+	lock  sync.RWMutex
+	db    ethdb.Database
+	stats map[uint64]*linReg
+}
+
+type requestCostStatsRlp []struct {
+	MsgCode uint64
+	Data    []byte
+}
+
+var rcStatsKey = []byte("_requestCostStats")
+
+func newCostStats(db ethdb.Database) *requestCostStats {
+	stats := make(map[uint64]*linReg)
+	for _, code := range reqList {
+		stats[code] = &linReg{cnt: 100}
+	}
+
+	if db != nil {
+		data, err := db.Get(rcStatsKey)
+		var statsRlp requestCostStatsRlp
+		if err == nil {
+			err = rlp.DecodeBytes(data, &statsRlp)
+		}
+		if err == nil {
+			for _, r := range statsRlp {
+				if stats[r.MsgCode] != nil {
+					if l := linRegFromBytes(r.Data); l != nil {
+						stats[r.MsgCode] = l
+					}
+				}
+			}
+		}
+	}
+
+	return &requestCostStats{
+		db:    db,
+		stats: stats,
+	}
+}
+
+func (s *requestCostStats) store() {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	statsRlp := make(requestCostStatsRlp, len(reqList))
+	for i, code := range reqList {
+		statsRlp[i].MsgCode = code
+		statsRlp[i].Data = s.stats[code].toBytes()
+	}
+
+	if data, err := rlp.EncodeToBytes(statsRlp); err == nil {
+		s.db.Put(rcStatsKey, data)
+	}
+}
+
+func (s *requestCostStats) getCurrentList() RequestCostList {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	list := make(RequestCostList, len(reqList))
+	//fmt.Println("RequestCostList")
+	for idx, code := range reqList {
+		b, m := s.stats[code].calc()
+		//fmt.Println(code, s.stats[code].cnt, b/1000000, m/1000000)
+		if m < 0 {
+			b += m
+			m = 0
+		}
+		if b < 0 {
+			b = 0
+		}
+
+		list[idx].MsgCode = code
+		list[idx].BaseCost = uint64(b * 2)
+		list[idx].ReqCost = uint64(m * 2)
+	}
+	return list
+}
+
+func (s *requestCostStats) update(msgCode, reqCnt, cost uint64) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	c, ok := s.stats[msgCode]
+	if !ok || reqCnt == 0 {
+		return
+	}
+	c.add(float64(reqCnt), float64(cost))
+}
+
+func (pm *ProtocolManager) blockLoop() {
+	pm.wg.Add(1)
+	sub := pm.eventMux.Subscribe(core.ChainHeadEvent{})
+	newCht := make(chan struct{}, 10)
+	newCht <- struct{}{}
+	go func() {
+		var mu sync.Mutex
+		var lastHead *types.Header
+		lastBroadcastTd := common.Big0
+		for {
+			select {
+			case ev := <-sub.Chan():
+				peers := pm.peers.AllPeers()
+				if len(peers) > 0 {
+					header := ev.Data.(core.ChainHeadEvent).Block.Header()
+					hash := header.Hash()
+					number := header.GetNumberU64()
+					td := core.GetTd(pm.chainDb, hash, number)
+					if td != nil && td.Cmp(lastBroadcastTd) > 0 {
+						var reorg uint64
+						if lastHead != nil {
+							reorg = lastHead.GetNumberU64() - core.FindCommonAncestor(pm.chainDb, header, lastHead).GetNumberU64()
+						}
+						lastHead = header
+						lastBroadcastTd = td
+						//fmt.Println("BROADCAST", number, hash, td, reorg)
+						announce := announceData{Hash: hash, Number: number, Td: td, ReorgDepth: reorg}
+						for _, p := range peers {
+							select {
+							case p.announceChn <- announce:
+							default:
+								pm.removePeer(p.id)
+							}
+						}
+					}
+				}
+				newCht <- struct{}{}
+			case <-newCht:
+				go func() {
+					mu.Lock()
+					more := makeCht(pm.chainDb)
+					mu.Unlock()
+					if more {
+						time.Sleep(time.Millisecond * 10)
+						newCht <- struct{}{}
+					}
+				}()
+			case <-pm.quitSync:
+				sub.Unsubscribe()
+				pm.wg.Done()
+				return
+			}
+		}
+	}()
+}
+
+var (
+	lastChtKey       = []byte("LastChtNumber") // chtNum (uint64 big endian)
+	chtPrefix        = []byte("cht")           // chtPrefix + chtNum (uint64 big endian) -> trie root hash
+	chtConfirmations = light.ChtFrequency / 2
+)
+
+func getChtRoot(db ethdb.Database, num uint64) common.Hash {
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], num)
+	data, _ := db.Get(append(chtPrefix, encNumber[:]...))
+	return common.BytesToHash(data)
+}
+
+func storeChtRoot(db ethdb.Database, num uint64, root common.Hash) {
+	var encNumber [8]byte
+	binary.BigEndian.PutUint64(encNumber[:], num)
+	db.Put(append(chtPrefix, encNumber[:]...), root[:])
+}
+
+func makeCht(db ethdb.Database) bool {
+	headHash := core.GetHeadBlockHash(db)
+	headNum := core.GetBlockNumber(db, headHash)
+
+	var newChtNum uint64
+	if headNum > chtConfirmations {
+		newChtNum = (headNum - chtConfirmations) / light.ChtFrequency
+	}
+
+	var lastChtNum uint64
+	data, _ := db.Get(lastChtKey)
+	if len(data) == 8 {
+		lastChtNum = binary.BigEndian.Uint64(data[:])
+	}
+	if newChtNum <= lastChtNum {
+		return false
+	}
+
+	var t *trie.Trie
+	if lastChtNum > 0 {
+		var err error
+		t, err = trie.New(getChtRoot(db, lastChtNum), db)
+		if err != nil {
+			lastChtNum = 0
+		}
+	}
+	if lastChtNum == 0 {
+		t, _ = trie.New(common.Hash{}, db)
+	}
+
+	for num := lastChtNum * light.ChtFrequency; num < (lastChtNum+1)*light.ChtFrequency; num++ {
+		hash := core.GetCanonicalHash(db, num)
+		if hash == (common.Hash{}) {
+			panic("Canonical hash not found")
+		}
+		td := core.GetTd(db, hash, num)
+		if td == nil {
+			panic("TD not found")
+		}
+		var encNumber [8]byte
+		binary.BigEndian.PutUint64(encNumber[:], num)
+		var node light.ChtNode
+		node.Hash = hash
+		node.Td = td
+		data, _ := rlp.EncodeToBytes(node)
+		t.Update(encNumber[:], data)
+	}
+
+	root, err := t.Commit()
+	if err != nil {
+		lastChtNum = 0
+	} else {
+		lastChtNum++
+		fmt.Printf("CHT %d %064x\n", lastChtNum, root)
+		storeChtRoot(db, lastChtNum, root)
+		var data [8]byte
+		binary.BigEndian.PutUint64(data[:], lastChtNum)
+		db.Put(lastChtKey, data[:])
+	}
+
+	return newChtNum > lastChtNum
+}

les/sync.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package les
+
+import (
+	"time"
+
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/light"
+	"golang.org/x/net/context"
+)
+
+const (
+	//forceSyncCycle      = 10 * time.Second // Time interval to force syncs, even if few peers are available
+	minDesiredPeerCount = 5 // Amount of peers desired to start syncing
+)
+
+// syncer is responsible for periodically synchronising with the network, both
+// downloading hashes and blocks as well as handling the announcement handler.
+func (pm *ProtocolManager) syncer() {
+	// Start and ensure cleanup of sync mechanisms
+	//pm.fetcher.Start()
+	//defer pm.fetcher.Stop()
+	defer pm.downloader.Terminate()
+
+	// Wait for different events to fire synchronisation operations
+	//forceSync := time.Tick(forceSyncCycle)
+	for {
+		select {
+		case <-pm.newPeerCh:
+/*			// Make sure we have peers to select from, then sync
+			if pm.peers.Len() < minDesiredPeerCount {
+				break
+			}
+			go pm.synchronise(pm.peers.BestPeer())
+*/
+		/*case <-forceSync:
+		// Force a sync even if not enough peers are present
+		go pm.synchronise(pm.peers.BestPeer())
+		*/
+		case <-pm.noMorePeers:
+			return
+		}
+	}
+}
+
+func (pm *ProtocolManager) needToSync(peerHead blockInfo) bool {
+	head := pm.blockchain.CurrentHeader()
+	currentTd := core.GetTd(pm.chainDb, head.Hash(), head.Number.Uint64())
+	return currentTd != nil && peerHead.Td.Cmp(currentTd) > 0
+}
+
+// synchronise tries to sync up our local block chain with a remote peer.
+func (pm *ProtocolManager) synchronise(peer *peer) {
+	// Short circuit if no peers are available
+	if peer == nil {
+		return
+	}
+
+	// Make sure the peer's TD is higher than our own.
+	if !pm.needToSync(peer.headBlockInfo()) {
+		return
+	}
+
+	ctx, _ := context.WithTimeout(context.Background(), time.Second*5)
+	pm.blockchain.(*light.LightChain).SyncCht(ctx)
+
+	pm.downloader.Synchronise(peer.id, peer.Head(), peer.Td(), downloader.LightSync)
+}

les/txrelay.go

+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+package les
+
+import (
+	"sync"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+type ltrInfo struct {
+	tx     *types.Transaction
+	sentTo map[*peer]struct{}
+}
+
+type LesTxRelay struct {
+	txSent       map[common.Hash]*ltrInfo
+	txPending    map[common.Hash]struct{}
+	ps           *peerSet
+	peerList     []*peer
+	peerStartPos int
+	lock         sync.RWMutex
+}
+
+func NewLesTxRelay() *LesTxRelay {
+	return &LesTxRelay{
+		txSent:    make(map[common.Hash]*ltrInfo),
+		txPending: make(map[common.Hash]struct{}),
+		ps:        newPeerSet(),
+	}
+}
+
+func (self *LesTxRelay) addPeer(p *peer) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	self.ps.Register(p)
+	self.peerList = self.ps.AllPeers()
+}
+
+func (self *LesTxRelay) removePeer(id string) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	self.ps.Unregister(id)
+	self.peerList = self.ps.AllPeers()
+}
+
+// send sends a list of transactions to at most a given number of peers at
+// once, never resending any particular transaction to the same peer twice
+func (self *LesTxRelay) send(txs types.Transactions, count int) {
+	sendTo := make(map[*peer]types.Transactions)
+
+	self.peerStartPos++ // rotate the starting position of the peer list
+	if self.peerStartPos >= len(self.peerList) {
+		self.peerStartPos = 0
+	}
+
+	for _, tx := range txs {
+		hash := tx.Hash()
+		ltr, ok := self.txSent[hash]
+		if !ok {
+			ltr = &ltrInfo{
+				tx:     tx,
+				sentTo: make(map[*peer]struct{}),
+			}
+			self.txSent[hash] = ltr
+			self.txPending[hash] = struct{}{}
+		}
+
+		if len(self.peerList) > 0 {
+			cnt := count
+			pos := self.peerStartPos
+			for {
+				peer := self.peerList[pos]
+				if _, ok := ltr.sentTo[peer]; !ok {
+					sendTo[peer] = append(sendTo[peer], tx)
+					ltr.sentTo[peer] = struct{}{}
+					cnt--
+				}
+				if cnt == 0 {
+					break // sent it to the desired number of peers
+				}
+				pos++
+				if pos == len(self.peerList) {
+					pos = 0
+				}
+				if pos == self.peerStartPos {
+					break // tried all available peers
+				}
+			}
+		}
+	}
+
+	for p, list := range sendTo {
+		cost := p.GetRequestCost(SendTxMsg, len(list))
+		go func(p *peer, list types.Transactions, cost uint64) {
+			p.fcServer.SendRequest(0, cost)
+			p.SendTxs(cost, list)
+		}(p, list, cost)
+	}
+}
+
+func (self *LesTxRelay) Send(txs types.Transactions) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	self.send(txs, 3)
+}
+
+func (self *LesTxRelay) NewHead(head common.Hash, mined []common.Hash, rollback []common.Hash) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	for _, hash := range mined {
+		delete(self.txPending, hash)
+	}
+
+	for _, hash := range rollback {
+		self.txPending[hash] = struct{}{}
+	}
+
+	if len(self.txPending) > 0 {
+		txs := make(types.Transactions, len(self.txPending))
+		i := 0
+		for hash, _ := range self.txPending {
+			txs[i] = self.txSent[hash].tx
+			i++
+		}
+		self.send(txs, 1)
+	}
+}
+
+func (self *LesTxRelay) Discard(hashes []common.Hash) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+
+	for _, hash := range hashes {
+		delete(self.txSent, hash)
+		delete(self.txPending, hash)
+	}
+}

vendor.conf

@@ -3,6 +3,7 @@ github.com/ethereum/go-ethereum
 
 # import
 github.com/Azure/azure-sdk-for-go	v5.0.0-beta-5-gbd73d95
+github.com/aristanetworks/goarista	ockafka-v0.0.2-7-g306a19f
 github.com/cespare/cp	165db2f
 github.com/davecgh/go-spew	v1.0.0-9-g346938d
 github.com/ethereum/ethash	v23.1-249-g214d4c0

vendor/github.com/aristanetworks/goarista/.travis.yml

+language: go
+go:
+- 1.6.2
+- tip
+before_install:
+- go get -v github.com/golang/lint/golint
+- go get -v -t -d ./...
+after_success:
+- make coverdata
+- bash <(curl -s https://codecov.io/bash)
+script:
+- make -j4 check GOTEST_FLAGS=-v
+notifications:
+  slack:
+    secure: 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

vendor/github.com/aristanetworks/goarista/AUTHORS

+All contributors are required to sign a "Contributor License Agreement" at
+  <TBD>
+
+The following organizations and people have contributed code to this library.
+(Please keep both lists sorted alphabetically.)
+
+
+Arista Networks, Inc.
+
+
+Benoit Sigoure
+Fabrice Rabaute
+
+
+
+The list of individual contributors for code currently in HEAD can be obtained
+at any time with the following script:
+
+find . -type f \
+| while read i; do \
+  git blame -t $i 2>/dev/null; \
+  done \
+| sed 's/^[0-9a-f]\{8\} [^(]*(\([^)]*\) [-+0-9 ]\{14,\}).*/\1/;s/ *$//' \
+| awk '{a[$0]++; t++} END{for(n in a) print n}' \
+| sort

vendor/github.com/aristanetworks/goarista/COPYING

+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
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+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
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+      including but not limited to software source code, documentation
+      source, and configuration files.
+
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+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
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+      designated in writing by the copyright owner as "Not a Contribution."
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+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
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+
+   4. Redistribution. You may reproduce and distribute copies of the
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+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
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+
+      (d) If the Work includes a "NOTICE" text file as part of its
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+          within a display generated by the Derivative Works, if and
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+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
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+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS

vendor/github.com/aristanetworks/goarista/Dockerfile

+# Copyright (C) 2016  Arista Networks, Inc.
+# Use of this source code is governed by the Apache License 2.0
+# that can be found in the COPYING file.
+
+# TODO: move this to cmd/ockafka (https://github.com/docker/hub-feedback/issues/292)
+FROM golang:1.6
+
+RUN mkdir -p /go/src/github.com/aristanetworks/goarista/cmd
+WORKDIR /go/src/github.com/aristanetworks/goarista
+COPY ./ .
+RUN go get -d ./cmd/ockafka/... \
+  && go install ./cmd/ockafka
+
+ENTRYPOINT ["/go/bin/ockafka"]

vendor/github.com/aristanetworks/goarista/Makefile

+# Copyright (C) 2015  Arista Networks, Inc.
+# Use of this source code is governed by the Apache License 2.0
+# that can be found in the COPYING file.
+
+GO := go
+TEST_TIMEOUT := 30s
+GOTEST_FLAGS :=
+
+DEFAULT_GOPATH := $${GOPATH%%:*}
+GOPATH_BIN := $(DEFAULT_GOPATH)/bin
+GOPATH_PKG := $(DEFAULT_GOPATH)/pkg
+GOLINT := $(GOPATH_BIN)/golint
+GOFOLDERS := find . -type d ! -path "./.git/*"
+
+all: install
+
+install:
+	$(GO) install ./...
+
+check: vet test fmtcheck lint
+
+COVER_PKGS := key test
+COVER_MODE := count
+coverdata:
+	echo 'mode: $(COVER_MODE)' >coverage.out
+	for dir in $(COVER_PKGS); do \
+	  $(GO) test -covermode=$(COVER_MODE) -coverprofile=cov.out-t ./$$dir || exit; \
+	  tail -n +2 cov.out-t >> coverage.out && \
+	  rm cov.out-t; \
+	done;
+
+coverage: coverdata
+	$(GO) tool cover -html=coverage.out
+	rm -f coverage.out
+
+fmtcheck:
+	errors=`gofmt -l .`; if test -n "$$errors"; then echo Check these files for style errors:; echo "$$errors"; exit 1; fi
+	find . -name '*.go' ! -name '*.pb.go' -exec ./check_line_len.awk {} +
+
+vet:
+	$(GO) vet ./...
+
+lint:
+	lint=`$(GOFOLDERS) | xargs -L 1 $(GOLINT) | fgrep -v .pb.go`; if test -n "$$lint"; then echo "$$lint"; exit 1; fi
+# The above is ugly, but unfortunately golint doesn't exit 1 when it finds
+# lint.  See https://github.com/golang/lint/issues/65
+
+test:
+	$(GO) test $(GOTEST_FLAGS) -timeout=$(TEST_TIMEOUT) ./...
+
+docker:
+	docker build -f cmd/occlient/Dockerfile .
+
+clean:
+	rm -rf $(GOPATH_PKG)/*/github.com/aristanetworks/goarista
+	$(GO) clean ./...
+
+.PHONY: all check coverage coverdata docker fmtcheck install lint test vet

vendor/github.com/aristanetworks/goarista/README.md

+# Arista Go library [![Build Status](https://travis-ci.org/aristanetworks/goarista.svg?branch=master)](https://travis-ci.org/aristanetworks/goarista) [![codecov.io](http://codecov.io/github/aristanetworks/goarista/coverage.svg?branch=master)](http://codecov.io/github/aristanetworks/goarista?branch=master) [![GoDoc](https://godoc.org/github.com/aristanetworks/goarista?status.png)](https://godoc.org/github.com/aristanetworks/goarista) [![Go Report Card](https://goreportcard.com/badge/github.com/aristanetworks/goarista)](https://goreportcard.com/report/github.com/aristanetworks/goarista)
+
+## areflect
+
+Helper functions to work with the `reflect` package.  Contains
+`ForceExport()`, which bypasses the check in `reflect.Value` that
+prevents accessing unexported attributes.
+
+## monotime
+
+Provides access to a fast monotonic clock source, to fill in the gap in the
+[Go standard library, which lacks one](https://github.com/golang/go/issues/12914).
+Don't use `time.Now()` in code that needs to time things or otherwise assume
+that time passes at a constant rate, instead use `monotime.Now()`.
+
+## cmd
+
+See the [cmd](cmd) directory.
+
+## dscp
+
+Provides `ListenTCPWithTOS()`, which is a replacement for `net.ListenTCP()`
+that allows specifying the ToS (Type of Service), to specify DSCP / ECN /
+class of service flags to use for incoming connections.
+
+## key
+
+Provides a common type used across various Arista projects, named `key.Key`,
+which is used to work around the fact that Go can't let one
+use a non-hashable type as a key to a `map`, and we sometimes need to use
+a `map[string]interface{}` (or something containing one) as a key to maps.
+As a result, we frequently use `map[key.Key]interface{}` instead of just
+`map[interface{}]interface{}` when we need a generic key-value collection.
+
+## lanz
+A client for [LANZ](https://eos.arista.com/latency-analyzer-lanz-architectures-and-configuration/)
+streaming servers. It connects to a LANZ streaming server,
+listens for notifications, decodes them and sends the LANZ protobuf on the
+provided channel.
+
+## monitor
+
+A library to help expose monitoring metrics on top of the
+[`expvar`](https://golang.org/pkg/expvar/) infrastructure.
+
+## netns
+
+`netns.Do(namespace, cb)` provides a handy mechanism to execute the given
+callback `cb` in the given [network namespace](https://lwn.net/Articles/580893/).
+
+## pathmap
+
+A datastructure for mapping keys of type string slice to values. It
+allows for some fuzzy matching.
+
+## test
+
+This is a [Go](http://golang.org/) library to help in writing unit tests.
+
+## Examples
+
+TBD

vendor/github.com/aristanetworks/goarista/check_line_len.awk

+#!/usr/bin/awk -f
+# Copyright (C) 2015  Arista Networks, Inc.
+# Use of this source code is governed by the Apache License 2.0
+# that can be found in the COPYING file.
+
+BEGIN {
+  max = 100;
+}
+
+# Expand tabs to 4 spaces.
+{
+  gsub(/\t/, "    ");
+}
+
+length() > max {
+  errors++;
+  print FILENAME ":" FNR ": Line too long (" length() "/" max ")";
+}
+
+END {
+  if (errors >= 125) {
+    errors = 125;
+  }
+  exit errors;
+}

vendor/github.com/aristanetworks/goarista/iptables.sh

+#!/bin/sh
+
+DEFAULT_PORT=6042
+
+set -e
+
+if [ "$#" -lt 1 ]
+then
+   echo "usage: $0 <host> [<port>]"
+   exit 1
+fi
+
+host=$1
+port=$DEFAULT_PORT
+if [ "$#" -gt 1 ]
+then
+   port=$2
+fi
+iptables="bash sudo iptables -A INPUT -p tcp --dport $port -j ACCEPT"
+ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no $host "$iptables"
+echo "opened TCP port $port on $host"

vendor/github.com/aristanetworks/goarista/monotime/issue15006.s

+// Copyright (C) 2016  Arista Networks, Inc.
+// Use of this source code is governed by the Apache License 2.0
+// that can be found in the COPYING file.
+
+// This file is intentionally empty.
+// It's a workaround for https://github.com/golang/go/issues/15006

vendor/github.com/aristanetworks/goarista/monotime/nanotime.go

+// Copyright (C) 2016  Arista Networks, Inc.
+// Use of this source code is governed by the Apache License 2.0
+// that can be found in the COPYING file.
+
+// Package monotime provides a fast monotonic clock source.
+package monotime
+
+import (
+	_ "unsafe" // required to use //go:linkname
+)
+
+//go:noescape
+//go:linkname nanotime runtime.nanotime
+func nanotime() int64
+
+// Now returns the current time in nanoseconds from a monotonic clock.
+// The time returned is based on some arbitrary platform-specific point in the
+// past.  The time returned is guaranteed to increase monotonically at a
+// constant rate, unlike time.Now() from the Go standard library, which may
+// slow down, speed up, jump forward or backward, due to NTP activity or leap
+// seconds.
+func Now() uint64 {
+	return uint64(nanotime())
+}

vendor/github.com/aristanetworks/goarista/rpmbuild.sh

+#!/bin/sh
+
+# Copyright (C) 2016  Arista Networks, Inc.
+# Use of this source code is governed by the Apache License 2.0
+# that can be found in the COPYING file.
+
+if [ "$#" -lt 1 ]
+then
+   echo "usage: $0 <binary>"
+   exit 1
+fi
+binary=$1
+
+if [ -z "$GOPATH" ] || [ -z "$GOOS" ] || [ -z "$GOARCH" ]
+then
+    echo "Please set \$GOPATH, \$GOOS and \$GOARCH"
+    exit 1
+fi
+
+set -e
+
+version=$(git rev-parse --short=7 HEAD)
+pwd=$(pwd)
+cd $GOPATH/bin
+if [ -d $GOOS_$GOARCH ]
+then
+   cd $GOOS_GOARCH
+fi
+os=$GOOS
+arch=$GOARCH
+if [ "$arch" == "386" ]
+then
+   arch="i686"
+fi
+cmd="fpm -n $binary -v $version -s dir -t rpm --rpm-os $os -a $arch --epoch 0 --prefix /usr/bin $binary"
+echo $cmd
+$cmd
+mv $binary-$version-1.$arch.rpm $pwd