Merge branch 'release/1.4'

(cherry picked from commit d87f7a1e81)

Makefile

@@ -13,7 +13,7 @@ GOBIN = build/bin
 GO ?= latest
 
 geth:
-	build/env.sh go install -v $(shell build/flags.sh) ./cmd/geth
+	build/env.sh go build -i -v $(shell build/flags.sh) -o $(GOBIN)/geth ./cmd/geth
 	@echo "Done building."
 	@echo "Run \"$(GOBIN)/geth\" to launch geth."
 
@@ -103,7 +103,9 @@ evm:
 	@echo "Run \"$(GOBIN)/evm to start the evm."
 
 all:
-	build/env.sh go install -v $(shell build/flags.sh) ./...
+	for cmd in `ls ./cmd/`; do \
+		 build/env.sh go build -i -v $(shell build/flags.sh) -o $(GOBIN)/$$cmd ./cmd/$$cmd; \
+	done
 
 test: all
 	build/env.sh go test ./...

VERSION

@@ -1 +1 @@
-1.4.1
+1.4.4

accounts/abi/abi.go

@@ -238,8 +238,16 @@ func (abi ABI) Unpack(v interface{}, name string, output []byte) error {
 		return fmt.Errorf("abi: unmarshalling empty output")
 	}
 
-	value := reflect.ValueOf(v).Elem()
-	typ := value.Type()
+	// make sure the passed value is a pointer
+	valueOf := reflect.ValueOf(v)
+	if reflect.Ptr != valueOf.Kind() {
+		return fmt.Errorf("abi: Unpack(non-pointer %T)", v)
+	}
+
+	var (
+		value = valueOf.Elem()
+		typ   = value.Type()
+	)
 
 	if len(method.Outputs) > 1 {
 		switch value.Kind() {
@@ -268,6 +276,25 @@ func (abi ABI) Unpack(v interface{}, name string, output []byte) error {
 				return fmt.Errorf("abi: cannot marshal tuple in to slice %T (only []interface{} is supported)", v)
 			}
 
+			// if the slice already contains values, set those instead of the interface slice itself.
+			if value.Len() > 0 {
+				if len(method.Outputs) > value.Len() {
+					return fmt.Errorf("abi: cannot marshal in to slices of unequal size (require: %v, got: %v)", len(method.Outputs), value.Len())
+				}
+
+				for i := 0; i < len(method.Outputs); i++ {
+					marshalledValue, err := toGoType(i, method.Outputs[i], output)
+					if err != nil {
+						return err
+					}
+					reflectValue := reflect.ValueOf(marshalledValue)
+					if err := set(value.Index(i).Elem(), reflectValue, method.Outputs[i]); err != nil {
+						return err
+					}
+				}
+				return nil
+			}
+
 			// create a new slice and start appending the unmarshalled
 			// values to the new interface slice.
 			z := reflect.MakeSlice(typ, 0, len(method.Outputs))
@@ -296,34 +323,6 @@ func (abi ABI) Unpack(v interface{}, name string, output []byte) error {
 	return nil
 }
 
-// set attempts to assign src to dst by either setting, copying or otherwise.
-//
-// set is a bit more lenient when it comes to assignment and doesn't force an as
-// strict ruleset as bare `reflect` does.
-func set(dst, src reflect.Value, output Argument) error {
-	dstType := dst.Type()
-	srcType := src.Type()
-
-	switch {
-	case dstType.AssignableTo(src.Type()):
-		dst.Set(src)
-	case dstType.Kind() == reflect.Array && srcType.Kind() == reflect.Slice:
-		if !dstType.Elem().AssignableTo(r_byte) {
-			return fmt.Errorf("abi: cannot unmarshal %v in to array of elem %v", src.Type(), dstType.Elem())
-		}
-
-		if dst.Len() < output.Type.SliceSize {
-			return fmt.Errorf("abi: cannot unmarshal src (len=%d) in to dst (len=%d)", output.Type.SliceSize, dst.Len())
-		}
-		reflect.Copy(dst, src)
-	case dstType.Kind() == reflect.Interface:
-		dst.Set(src)
-	default:
-		return fmt.Errorf("abi: cannot unmarshal %v in to %v", src.Type(), dst.Type())
-	}
-	return nil
-}
-
 func (abi *ABI) UnmarshalJSON(data []byte) error {
 	var fields []struct {
 		Type     string

accounts/abi/abi_test.go

@@ -289,6 +289,37 @@ func TestSimpleMethodUnpack(t *testing.T) {
 	}
 }
 
+func TestUnpackSetInterfaceSlice(t *testing.T) {
+	var (
+		var1 = new(uint8)
+		var2 = new(uint8)
+	)
+	out := []interface{}{var1, var2}
+	abi, err := JSON(strings.NewReader(`[{"type":"function", "name":"ints", "outputs":[{"type":"uint8"}, {"type":"uint8"}]}]`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	marshalledReturn := append(pad([]byte{1}, 32, true), pad([]byte{2}, 32, true)...)
+	err = abi.Unpack(&out, "ints", marshalledReturn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if *var1 != 1 {
+		t.Errorf("expected var1 to be 1, got", *var1)
+	}
+	if *var2 != 2 {
+		t.Errorf("expected var2 to be 2, got", *var2)
+	}
+
+	out = []interface{}{var1}
+	err = abi.Unpack(&out, "ints", marshalledReturn)
+
+	expErr := "abi: cannot marshal in to slices of unequal size (require: 2, got: 1)"
+	if err == nil || err.Error() != expErr {
+		t.Error("expected err:", expErr, "Got:", err)
+	}
+}
+
 func TestPack(t *testing.T) {
 	for i, test := range []struct {
 		typ string

accounts/abi/bind/bind_test.go

@@ -194,12 +194,44 @@ var bindTests = []struct {
 			}
 		`,
 	},
+	// Tests that plain values can be properly returned and deserialized
+	{
+		`Getter`,
+		`
+			contract Getter {
+				function getter() constant returns (string, int, bytes32) {
+					return ("Hi", 1, sha3(""));
+				}
+			}
+		`,
+		`606060405260dc8060106000396000f3606060405260e060020a6000350463993a04b78114601a575b005b600060605260c0604052600260809081527f486900000000000000000000000000000000000000000000000000000000000060a05260017fc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a47060e0829052610100819052606060c0908152600261012081905281906101409060a09080838184600060046012f1505081517fffff000000000000000000000000000000000000000000000000000000000000169091525050604051610160819003945092505050f3`,
+		`[{"constant":true,"inputs":[],"name":"getter","outputs":[{"name":"","type":"string"},{"name":"","type":"int256"},{"name":"","type":"bytes32"}],"type":"function"}]`,
+		`
+			// Generate a new random account and a funded simulator
+			key, _ := crypto.GenerateKey()
+			auth := bind.NewKeyedTransactor(key)
+			sim := backends.NewSimulatedBackend(core.GenesisAccount{Address: auth.From, Balance: big.NewInt(10000000000)})
+
+			// Deploy a tuple tester contract and execute a structured call on it
+			_, _, getter, err := DeployGetter(auth, sim)
+			if err != nil {
+				t.Fatalf("Failed to deploy getter contract: %v", err)
+			}
+			sim.Commit()
+
+			if str, num, _, err := getter.Getter(nil); err != nil {
+				t.Fatalf("Failed to call anonymous field retriever: %v", err)
+			} else if str != "Hi" || num.Cmp(big.NewInt(1)) != 0 {
+				t.Fatalf("Retrieved value mismatch: have %v/%v, want %v/%v", str, num, "Hi", 1)
+			}
+		`,
+	},
 	// Tests that tuples can be properly returned and deserialized
 	{
 		`Tupler`,
 		`
 			contract Tupler {
-				function tuple() returns (string a, int b, bytes32 c) {
+				function tuple() constant returns (string a, int b, bytes32 c) {
 					return ("Hi", 1, sha3(""));
 				}
 			}
@@ -219,8 +251,10 @@ var bindTests = []struct {
 			}
 			sim.Commit()
 
-			if _, err := tupler.Tuple(nil); err != nil {
+			if res, err := tupler.Tuple(nil); err != nil {
 				t.Fatalf("Failed to call structure retriever: %v", err)
+			} else if res.A != "Hi" || res.B.Cmp(big.NewInt(1)) != 0 {
+				t.Fatalf("Retrieved value mismatch: have %v/%v, want %v/%v", res.A, res.B, "Hi", 1)
 			}
 		`,
 	},

accounts/abi/bind/template.go

@@ -211,7 +211,7 @@ package {{.Package}}
 				{{range $i, $_ := .Normalized.Outputs}}ret{{$i}} = new({{bindtype .Type}})
 				{{end}}
 			){{end}}
-			out := {{if .Structured}}ret{{else}}{{if eq (len .Normalized.Outputs) 1}}ret0{{else}}[]interface{}{
+			out := {{if .Structured}}ret{{else}}{{if eq (len .Normalized.Outputs) 1}}ret0{{else}}&[]interface{}{
 				{{range $i, $_ := .Normalized.Outputs}}ret{{$i}},
 				{{end}}
 			}{{end}}{{end}}

accounts/abi/reflect.go

@@ -16,7 +16,10 @@
 
 package abi
 
-import "reflect"
+import (
+	"fmt"
+	"reflect"
+)
 
 // indirect recursively dereferences the value until it either gets the value
 // or finds a big.Int
@@ -62,3 +65,33 @@ func mustArrayToByteSlice(value reflect.Value) reflect.Value {
 	reflect.Copy(slice, value)
 	return slice
 }
+
+// set attempts to assign src to dst by either setting, copying or otherwise.
+//
+// set is a bit more lenient when it comes to assignment and doesn't force an as
+// strict ruleset as bare `reflect` does.
+func set(dst, src reflect.Value, output Argument) error {
+	dstType := dst.Type()
+	srcType := src.Type()
+
+	switch {
+	case dstType.AssignableTo(src.Type()):
+		dst.Set(src)
+	case dstType.Kind() == reflect.Array && srcType.Kind() == reflect.Slice:
+		if !dstType.Elem().AssignableTo(r_byte) {
+			return fmt.Errorf("abi: cannot unmarshal %v in to array of elem %v", src.Type(), dstType.Elem())
+		}
+
+		if dst.Len() < output.Type.SliceSize {
+			return fmt.Errorf("abi: cannot unmarshal src (len=%d) in to dst (len=%d)", output.Type.SliceSize, dst.Len())
+		}
+		reflect.Copy(dst, src)
+	case dstType.Kind() == reflect.Interface:
+		dst.Set(src)
+	case dstType.Kind() == reflect.Ptr:
+		return set(dst.Elem(), src, output)
+	default:
+		return fmt.Errorf("abi: cannot unmarshal %v in to %v", src.Type(), dst.Type())
+	}
+	return nil
+}

build/win-ci-compile.bat

@@ -0,0 +1,26 @@
+@echo off
+if not exist .\build\win-ci-compile.bat (
+   echo This script must be run from the root of the repository.
+   exit /b
+)
+if not defined GOPATH (
+   echo GOPATH is not set.
+   exit /b
+)
+
+set GOPATH=%GOPATH%;%cd%\Godeps\_workspace
+set GOBIN=%cd%\build\bin
+
+rem set gitCommit when running from a Git checkout.
+set goLinkFlags=""
+if exist ".git\HEAD" (
+   where /q git
+   if not errorlevel 1 (
+      for /f %%h in ('git rev-parse HEAD') do (
+          set goLinkFlags="-X main.gitCommit=%%h"
+      )
+   )
+)
+
+@echo on
+go install -v -ldflags %goLinkFlags% ./...

build/win-ci-test.bat

@@ -0,0 +1,15 @@
+@echo off
+if not exist .\build\win-ci-test.bat (
+   echo This script must be run from the root of the repository.
+   exit /b
+)
+if not defined GOPATH (
+   echo GOPATH is not set.
+   exit /b
+)
+
+set GOPATH=%GOPATH%;%cd%\Godeps\_workspace
+set GOBIN=%cd%\build\bin
+
+@echo on
+go test ./...

cmd/geth/main.go

@@ -47,11 +47,11 @@ import (
 )
 
 const (
-	clientIdentifier = "Geth" // Client identifier to advertise over the network
-	versionMajor     = 1      // Major version component of the current release
-	versionMinor     = 4      // Minor version component of the current release
-	versionPatch     = 1      // Patch version component of the current release
-	versionMeta      = "rc"   // Version metadata to append to the version string
+	clientIdentifier = "Geth"   // Client identifier to advertise over the network
+	versionMajor     = 1        // Major version component of the current release
+	versionMinor     = 4        // Minor version component of the current release
+	versionPatch     = 4        // Patch version component of the current release
+	versionMeta      = "stable" // Version metadata to append to the version string
 
 	versionOracle = "0xfa7b9770ca4cb04296cac84f37736d4041251cdf" // Ethereum address of the Geth release oracle
 )

cmd/utils/cmd.go

@@ -73,15 +73,13 @@ func StartNode(stack *node.Node) {
 		<-sigc
 		glog.V(logger.Info).Infoln("Got interrupt, shutting down...")
 		go stack.Stop()
-		logger.Flush()
 		for i := 10; i > 0; i-- {
 			<-sigc
 			if i > 1 {
-				glog.V(logger.Info).Infoln("Already shutting down, please be patient.")
-				glog.V(logger.Info).Infoln("Interrupt", i-1, "more times to induce panic.")
+				glog.V(logger.Info).Infof("Already shutting down, interrupt %d more times for panic.", i-1)
 			}
 		}
-		glog.V(logger.Error).Infof("Force quitting: this might not end so well.")
+		debug.Exit() // ensure trace and CPU profile data is flushed.
 		debug.LoudPanic("boom")
 	}()
 }

cmd/utils/fdlimit_freebsd.go

@@ -0,0 +1,54 @@
+// Copyright 2016 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/>.
+
+// +build freebsd
+
+package utils
+
+import "syscall"
+
+// This file is largely identical to fdlimit_unix.go,
+// but Rlimit fields have type int64 on FreeBSD so it needs
+// an extra conversion.
+
+// raiseFdLimit tries to maximize the file descriptor allowance of this process
+// to the maximum hard-limit allowed by the OS.
+func raiseFdLimit(max uint64) error {
+	// Get the current limit
+	var limit syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
+		return err
+	}
+	// Try to update the limit to the max allowance
+	limit.Cur = limit.Max
+	if limit.Cur > int64(max) {
+		limit.Cur = int64(max)
+	}
+	if err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
+		return err
+	}
+	return nil
+}
+
+// getFdLimit retrieves the number of file descriptors allowed to be opened by this
+// process.
+func getFdLimit() (int, error) {
+	var limit syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
+		return 0, err
+	}
+	return int(limit.Cur), nil
+}

cmd/utils/fdlimit_unix.go

@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
 
-// +build linux darwin
+// +build linux darwin netbsd openbsd solaris
 
 package utils
 

core/block_validator.go

@@ -292,7 +292,7 @@ func calcDifficultyHomestead(time, parentTime uint64, parentNumber, parentDiff *
 
 	// minimum difficulty can ever be (before exponential factor)
 	if x.Cmp(params.MinimumDifficulty) < 0 {
-		x = params.MinimumDifficulty
+		x.Set(params.MinimumDifficulty)
 	}
 
 	// for the exponential factor
@@ -325,7 +325,7 @@ func calcDifficultyFrontier(time, parentTime uint64, parentNumber, parentDiff *b
 		diff.Sub(parentDiff, adjust)
 	}
 	if diff.Cmp(params.MinimumDifficulty) < 0 {
-		diff = params.MinimumDifficulty
+		diff.Set(params.MinimumDifficulty)
 	}
 
 	periodCount := new(big.Int).Add(parentNumber, common.Big1)

core/tx_pool.go

@@ -60,8 +60,7 @@ type stateFn func() (*state.StateDB, error)
 // two states over time as they are received and processed.
 type TxPool struct {
 	config       *ChainConfig
-	quit         chan bool // Quitting channel
-	currentState stateFn   // The state function which will allow us to do some pre checks
+	currentState stateFn // The state function which will allow us to do some pre checks
 	pendingState *state.ManagedState
 	gasLimit     func() *big.Int // The current gas limit function callback
 	minGasPrice  *big.Int
@@ -72,6 +71,8 @@ type TxPool struct {
 	pending      map[common.Hash]*types.Transaction // processable transactions
 	queue        map[common.Address]map[common.Hash]*types.Transaction
 
+	wg sync.WaitGroup // for shutdown sync
+
 	homestead bool
 }
 
@@ -80,7 +81,6 @@ func NewTxPool(config *ChainConfig, eventMux *event.TypeMux, currentStateFn stat
 		config:       config,
 		pending:      make(map[common.Hash]*types.Transaction),
 		queue:        make(map[common.Address]map[common.Hash]*types.Transaction),
-		quit:         make(chan bool),
 		eventMux:     eventMux,
 		currentState: currentStateFn,
 		gasLimit:     gasLimitFn,
@@ -90,12 +90,15 @@ func NewTxPool(config *ChainConfig, eventMux *event.TypeMux, currentStateFn stat
 		events:       eventMux.Subscribe(ChainHeadEvent{}, GasPriceChanged{}, RemovedTransactionEvent{}),
 	}
 
+	pool.wg.Add(1)
 	go pool.eventLoop()
 
 	return pool
 }
 
 func (pool *TxPool) eventLoop() {
+	defer pool.wg.Done()
+
 	// Track chain events. When a chain events occurs (new chain canon block)
 	// we need to know the new state. The new state will help us determine
 	// the nonces in the managed state
@@ -155,8 +158,8 @@ func (pool *TxPool) resetState() {
 }
 
 func (pool *TxPool) Stop() {
-	close(pool.quit)
 	pool.events.Unsubscribe()
+	pool.wg.Wait()
 	glog.V(logger.Info).Infoln("Transaction pool stopped")
 }
 

eth/api.go

@@ -1841,7 +1841,7 @@ func (s *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger *vm.LogCon
 		}
 		// Mutate the state if we haven't reached the tracing transaction yet
 		if uint64(idx) < txIndex {
-			vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, parent.Header(), vm.Config{})
+			vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, block.Header(), vm.Config{})
 			_, _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
 			if err != nil {
 				return nil, fmt.Errorf("mutation failed: %v", err)
@@ -1849,7 +1849,7 @@ func (s *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger *vm.LogCon
 			continue
 		}
 		// Otherwise trace the transaction and return
-		vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, parent.Header(), vm.Config{Debug: true, Logger: *logger})
+		vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, block.Header(), vm.Config{Debug: true, Logger: *logger})
 		ret, gas, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
 		if err != nil {
 			return nil, fmt.Errorf("tracing failed: %v", err)

eth/backend.go

@@ -416,6 +416,7 @@ func (s *Ethereum) Stop() error {
 	s.blockchain.Stop()
 	s.protocolManager.Stop()
 	s.txPool.Stop()
+	s.miner.Stop()
 	s.eventMux.Stop()
 
 	s.StopAutoDAG()

eth/downloader/downloader.go

@@ -34,6 +34,7 @@ import (
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/rcrowley/go-metrics"
 )
 
@@ -45,6 +46,8 @@ var (
 	MaxReceiptFetch = 256 // Amount of transaction receipts to allow fetching per request
 	MaxStateFetch   = 384 // Amount of node state values to allow fetching per request
 
+	MaxForkAncestry = 3 * params.EpochDuration.Uint64() // Maximum chain reorganisation
+
 	hashTTL        = 3 * time.Second     // [eth/61] Time it takes for a hash request to time out
 	blockTargetRTT = 3 * time.Second / 2 // [eth/61] Target time for completing a block retrieval request
 	blockTTL       = 3 * blockTargetRTT  // [eth/61] Maximum time allowance before a block request is considered expired
@@ -79,6 +82,7 @@ var (
 	errEmptyHeaderSet     = errors.New("empty header set by peer")
 	errPeersUnavailable   = errors.New("no peers available or all tried for download")
 	errAlreadyInPool      = errors.New("hash already in pool")
+	errInvalidAncestor    = errors.New("retrieved ancestor is invalid")
 	errInvalidChain       = errors.New("retrieved hash chain is invalid")
 	errInvalidBlock       = errors.New("retrieved block is invalid")
 	errInvalidBody        = errors.New("retrieved block body is invalid")
@@ -266,7 +270,7 @@ func (d *Downloader) Synchronise(id string, head common.Hash, td *big.Int, mode
 	case errBusy:
 		glog.V(logger.Detail).Infof("Synchronisation already in progress")
 
-	case errTimeout, errBadPeer, errStallingPeer, errEmptyHashSet, errEmptyHeaderSet, errPeersUnavailable, errInvalidChain:
+	case errTimeout, errBadPeer, errStallingPeer, errEmptyHashSet, errEmptyHeaderSet, errPeersUnavailable, errInvalidAncestor, errInvalidChain:
 		glog.V(logger.Debug).Infof("Removing peer %v: %v", id, err)
 		d.dropPeer(id)
 
@@ -353,7 +357,7 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 		if err != nil {
 			return err
 		}
-		origin, err := d.findAncestor61(p)
+		origin, err := d.findAncestor61(p, latest)
 		if err != nil {
 			return err
 		}
@@ -380,7 +384,7 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 		if err != nil {
 			return err
 		}
-		origin, err := d.findAncestor(p)
+		origin, err := d.findAncestor(p, latest)
 		if err != nil {
 			return err
 		}
@@ -536,11 +540,19 @@ func (d *Downloader) fetchHeight61(p *peer) (uint64, error) {
 // on the correct chain, checking the top N blocks should already get us a match.
 // In the rare scenario when we ended up on a long reorganisation (i.e. none of
 // the head blocks match), we do a binary search to find the common ancestor.
-func (d *Downloader) findAncestor61(p *peer) (uint64, error) {
+func (d *Downloader) findAncestor61(p *peer, height uint64) (uint64, error) {
 	glog.V(logger.Debug).Infof("%v: looking for common ancestor", p)
 
-	// Request out head blocks to short circuit ancestor location
-	head := d.headBlock().NumberU64()
+	// Figure out the valid ancestor range to prevent rewrite attacks
+	floor, ceil := int64(-1), d.headBlock().NumberU64()
+	if ceil >= MaxForkAncestry {
+		floor = int64(ceil - MaxForkAncestry)
+	}
+	// Request the topmost blocks to short circuit binary ancestor lookup
+	head := ceil
+	if head > height {
+		head = height
+	}
 	from := int64(head) - int64(MaxHashFetch) + 1
 	if from < 0 {
 		from = 0
@@ -600,11 +612,18 @@ func (d *Downloader) findAncestor61(p *peer) (uint64, error) {
 	}
 	// If the head fetch already found an ancestor, return
 	if !common.EmptyHash(hash) {
+		if int64(number) <= floor {
+			glog.V(logger.Warn).Infof("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, number, hash[:4], floor)
+			return 0, errInvalidAncestor
+		}
 		glog.V(logger.Debug).Infof("%v: common ancestor: #%d [%x…]", p, number, hash[:4])
 		return number, nil
 	}
 	// Ancestor not found, we need to binary search over our chain
 	start, end := uint64(0), head
+	if floor > 0 {
+		start = uint64(floor)
+	}
 	for start+1 < end {
 		// Split our chain interval in two, and request the hash to cross check
 		check := (start + end) / 2
@@ -660,6 +679,12 @@ func (d *Downloader) findAncestor61(p *peer) (uint64, error) {
 			}
 		}
 	}
+	// Ensure valid ancestry and return
+	if int64(start) <= floor {
+		glog.V(logger.Warn).Infof("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, start, hash[:4], floor)
+		return 0, errInvalidAncestor
+	}
+	glog.V(logger.Debug).Infof("%v: common ancestor: #%d [%x…]", p, start, hash[:4])
 	return start, nil
 }
 
@@ -961,15 +986,23 @@ func (d *Downloader) fetchHeight(p *peer) (uint64, error) {
 // on the correct chain, checking the top N links should already get us a match.
 // In the rare scenario when we ended up on a long reorganisation (i.e. none of
 // the head links match), we do a binary search to find the common ancestor.
-func (d *Downloader) findAncestor(p *peer) (uint64, error) {
+func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 	glog.V(logger.Debug).Infof("%v: looking for common ancestor", p)
 
-	// Request our head headers to short circuit ancestor location
-	head := d.headHeader().Number.Uint64()
+	// Figure out the valid ancestor range to prevent rewrite attacks
+	floor, ceil := int64(-1), d.headHeader().Number.Uint64()
 	if d.mode == FullSync {
-		head = d.headBlock().NumberU64()
+		ceil = d.headBlock().NumberU64()
 	} else if d.mode == FastSync {
-		head = d.headFastBlock().NumberU64()
+		ceil = d.headFastBlock().NumberU64()
+	}
+	if ceil >= MaxForkAncestry {
+		floor = int64(ceil - MaxForkAncestry)
+	}
+	// Request the topmost blocks to short circuit binary ancestor lookup
+	head := ceil
+	if head > height {
+		head = height
 	}
 	from := int64(head) - int64(MaxHeaderFetch) + 1
 	if from < 0 {
@@ -1040,11 +1073,18 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 	}
 	// If the head fetch already found an ancestor, return
 	if !common.EmptyHash(hash) {
+		if int64(number) <= floor {
+			glog.V(logger.Warn).Infof("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, number, hash[:4], floor)
+			return 0, errInvalidAncestor
+		}
 		glog.V(logger.Debug).Infof("%v: common ancestor: #%d [%x…]", p, number, hash[:4])
 		return number, nil
 	}
 	// Ancestor not found, we need to binary search over our chain
 	start, end := uint64(0), head
+	if floor > 0 {
+		start = uint64(floor)
+	}
 	for start+1 < end {
 		// Split our chain interval in two, and request the hash to cross check
 		check := (start + end) / 2
@@ -1100,6 +1140,12 @@ func (d *Downloader) findAncestor(p *peer) (uint64, error) {
 			}
 		}
 	}
+	// Ensure valid ancestry and return
+	if int64(start) <= floor {
+		glog.V(logger.Warn).Infof("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, start, hash[:4], floor)
+		return 0, errInvalidAncestor
+	}
+	glog.V(logger.Debug).Infof("%v: common ancestor: #%d [%x…]", p, start, hash[:4])
 	return start, nil
 }
 

eth/downloader/downloader_test.go

@@ -43,8 +43,9 @@ var (
 	genesis     = core.GenesisBlockForTesting(testdb, testAddress, big.NewInt(1000000000))
 )
 
-// Reduce the block cache limit, otherwise the tests will be very heavy.
+// Reduce some of the parameters to make the tester faster.
 func init() {
+	MaxForkAncestry = uint64(10000)
 	blockCacheLimit = 1024
 }
 
@@ -52,11 +53,15 @@ func init() {
 // the returned hash chain is ordered head->parent. In addition, every 3rd block
 // contains a transaction and every 5th an uncle to allow testing correct block
 // reassembly.
-func makeChain(n int, seed byte, parent *types.Block, parentReceipts types.Receipts) ([]common.Hash, map[common.Hash]*types.Header, map[common.Hash]*types.Block, map[common.Hash]types.Receipts) {
+func makeChain(n int, seed byte, parent *types.Block, parentReceipts types.Receipts, heavy bool) ([]common.Hash, map[common.Hash]*types.Header, map[common.Hash]*types.Block, map[common.Hash]types.Receipts) {
 	// Generate the block chain
 	blocks, receipts := core.GenerateChain(parent, testdb, n, func(i int, block *core.BlockGen) {
 		block.SetCoinbase(common.Address{seed})
 
+		// If a heavy chain is requested, delay blocks to raise difficulty
+		if heavy {
+			block.OffsetTime(-1)
+		}
 		// If the block number is multiple of 3, send a bonus transaction to the miner
 		if parent == genesis && i%3 == 0 {
 			tx, err := types.NewTransaction(block.TxNonce(testAddress), common.Address{seed}, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(testKey)
@@ -97,15 +102,19 @@ func makeChain(n int, seed byte, parent *types.Block, parentReceipts types.Recei
 
 // makeChainFork creates two chains of length n, such that h1[:f] and
 // h2[:f] are different but have a common suffix of length n-f.
-func makeChainFork(n, f int, parent *types.Block, parentReceipts types.Receipts) ([]common.Hash, []common.Hash, map[common.Hash]*types.Header, map[common.Hash]*types.Header, map[common.Hash]*types.Block, map[common.Hash]*types.Block, map[common.Hash]types.Receipts, map[common.Hash]types.Receipts) {
+func makeChainFork(n, f int, parent *types.Block, parentReceipts types.Receipts, balanced bool) ([]common.Hash, []common.Hash, map[common.Hash]*types.Header, map[common.Hash]*types.Header, map[common.Hash]*types.Block, map[common.Hash]*types.Block, map[common.Hash]types.Receipts, map[common.Hash]types.Receipts) {
 	// Create the common suffix
-	hashes, headers, blocks, receipts := makeChain(n-f, 0, parent, parentReceipts)
+	hashes, headers, blocks, receipts := makeChain(n-f, 0, parent, parentReceipts, false)
 
-	// Create the forks
-	hashes1, headers1, blocks1, receipts1 := makeChain(f, 1, blocks[hashes[0]], receipts[hashes[0]])
+	// Create the forks, making the second heavyer if non balanced forks were requested
+	hashes1, headers1, blocks1, receipts1 := makeChain(f, 1, blocks[hashes[0]], receipts[hashes[0]], false)
 	hashes1 = append(hashes1, hashes[1:]...)
 
-	hashes2, headers2, blocks2, receipts2 := makeChain(f, 2, blocks[hashes[0]], receipts[hashes[0]])
+	heavy := false
+	if !balanced {
+		heavy = true
+	}
+	hashes2, headers2, blocks2, receipts2 := makeChain(f, 2, blocks[hashes[0]], receipts[hashes[0]], heavy)
 	hashes2 = append(hashes2, hashes[1:]...)
 
 	for hash, header := range headers {
@@ -712,7 +721,7 @@ func testCanonicalSynchronisation(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 	tester.newPeer("peer", protocol, hashes, headers, blocks, receipts)
@@ -736,7 +745,7 @@ func TestThrottling64Fast(t *testing.T) { testThrottling(t, 64, FastSync) }
 func testThrottling(t *testing.T, protocol int, mode SyncMode) {
 	// Create a long block chain to download and the tester
 	targetBlocks := 8 * blockCacheLimit
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 	tester.newPeer("peer", protocol, hashes, headers, blocks, receipts)
@@ -810,20 +819,20 @@ func testThrottling(t *testing.T, protocol int, mode SyncMode) {
 // Tests that simple synchronization against a forked chain works correctly. In
 // this test common ancestor lookup should *not* be short circuited, and a full
 // binary search should be executed.
-func TestForkedSynchronisation61(t *testing.T)      { testForkedSynchronisation(t, 61, FullSync) }
-func TestForkedSynchronisation62(t *testing.T)      { testForkedSynchronisation(t, 62, FullSync) }
-func TestForkedSynchronisation63Full(t *testing.T)  { testForkedSynchronisation(t, 63, FullSync) }
-func TestForkedSynchronisation63Fast(t *testing.T)  { testForkedSynchronisation(t, 63, FastSync) }
-func TestForkedSynchronisation64Full(t *testing.T)  { testForkedSynchronisation(t, 64, FullSync) }
-func TestForkedSynchronisation64Fast(t *testing.T)  { testForkedSynchronisation(t, 64, FastSync) }
-func TestForkedSynchronisation64Light(t *testing.T) { testForkedSynchronisation(t, 64, LightSync) }
+func TestForkedSync61(t *testing.T)      { testForkedSync(t, 61, FullSync) }
+func TestForkedSync62(t *testing.T)      { testForkedSync(t, 62, FullSync) }
+func TestForkedSync63Full(t *testing.T)  { testForkedSync(t, 63, FullSync) }
+func TestForkedSync63Fast(t *testing.T)  { testForkedSync(t, 63, FastSync) }
+func TestForkedSync64Full(t *testing.T)  { testForkedSync(t, 64, FullSync) }
+func TestForkedSync64Fast(t *testing.T)  { testForkedSync(t, 64, FastSync) }
+func TestForkedSync64Light(t *testing.T) { testForkedSync(t, 64, LightSync) }
 
-func testForkedSynchronisation(t *testing.T, protocol int, mode SyncMode) {
+func testForkedSync(t *testing.T, protocol int, mode SyncMode) {
 	t.Parallel()
 
 	// Create a long enough forked chain
 	common, fork := MaxHashFetch, 2*MaxHashFetch
-	hashesA, hashesB, headersA, headersB, blocksA, blocksB, receiptsA, receiptsB := makeChainFork(common+fork, fork, genesis, nil)
+	hashesA, hashesB, headersA, headersB, blocksA, blocksB, receiptsA, receiptsB := makeChainFork(common+fork, fork, genesis, nil, true)
 
 	tester := newTester()
 	tester.newPeer("fork A", protocol, hashesA, headersA, blocksA, receiptsA)
@@ -842,6 +851,40 @@ func testForkedSynchronisation(t *testing.T, protocol int, mode SyncMode) {
 	assertOwnForkedChain(t, tester, common+1, []int{common + fork + 1, common + fork + 1})
 }
 
+// Tests that synchronising against a much shorter but much heavyer fork works
+// corrently and is not dropped.
+func TestHeavyForkedSync61(t *testing.T)      { testHeavyForkedSync(t, 61, FullSync) }
+func TestHeavyForkedSync62(t *testing.T)      { testHeavyForkedSync(t, 62, FullSync) }
+func TestHeavyForkedSync63Full(t *testing.T)  { testHeavyForkedSync(t, 63, FullSync) }
+func TestHeavyForkedSync63Fast(t *testing.T)  { testHeavyForkedSync(t, 63, FastSync) }
+func TestHeavyForkedSync64Full(t *testing.T)  { testHeavyForkedSync(t, 64, FullSync) }
+func TestHeavyForkedSync64Fast(t *testing.T)  { testHeavyForkedSync(t, 64, FastSync) }
+func TestHeavyForkedSync64Light(t *testing.T) { testHeavyForkedSync(t, 64, LightSync) }
+
+func testHeavyForkedSync(t *testing.T, protocol int, mode SyncMode) {
+	t.Parallel()
+
+	// Create a long enough forked chain
+	common, fork := MaxHashFetch, 4*MaxHashFetch
+	hashesA, hashesB, headersA, headersB, blocksA, blocksB, receiptsA, receiptsB := makeChainFork(common+fork, fork, genesis, nil, false)
+
+	tester := newTester()
+	tester.newPeer("light", protocol, hashesA, headersA, blocksA, receiptsA)
+	tester.newPeer("heavy", protocol, hashesB[fork/2:], headersB, blocksB, receiptsB)
+
+	// Synchronise with the peer and make sure all blocks were retrieved
+	if err := tester.sync("light", nil, mode); err != nil {
+		t.Fatalf("failed to synchronise blocks: %v", err)
+	}
+	assertOwnChain(t, tester, common+fork+1)
+
+	// Synchronise with the second peer and make sure that fork is pulled too
+	if err := tester.sync("heavy", nil, mode); err != nil {
+		t.Fatalf("failed to synchronise blocks: %v", err)
+	}
+	assertOwnForkedChain(t, tester, common+1, []int{common + fork + 1, common + fork/2 + 1})
+}
+
 // Tests that an inactive downloader will not accept incoming hashes and blocks.
 func TestInactiveDownloader61(t *testing.T) {
 	t.Parallel()
@@ -856,6 +899,74 @@ func TestInactiveDownloader61(t *testing.T) {
 	}
 }
 
+// Tests that chain forks are contained within a certain interval of the current
+// chain head, ensuring that malicious peers cannot waste resources by feeding
+// long dead chains.
+func TestBoundedForkedSync61(t *testing.T)      { testBoundedForkedSync(t, 61, FullSync) }
+func TestBoundedForkedSync62(t *testing.T)      { testBoundedForkedSync(t, 62, FullSync) }
+func TestBoundedForkedSync63Full(t *testing.T)  { testBoundedForkedSync(t, 63, FullSync) }
+func TestBoundedForkedSync63Fast(t *testing.T)  { testBoundedForkedSync(t, 63, FastSync) }
+func TestBoundedForkedSync64Full(t *testing.T)  { testBoundedForkedSync(t, 64, FullSync) }
+func TestBoundedForkedSync64Fast(t *testing.T)  { testBoundedForkedSync(t, 64, FastSync) }
+func TestBoundedForkedSync64Light(t *testing.T) { testBoundedForkedSync(t, 64, LightSync) }
+
+func testBoundedForkedSync(t *testing.T, protocol int, mode SyncMode) {
+	t.Parallel()
+
+	// Create a long enough forked chain
+	common, fork := 13, int(MaxForkAncestry+17)
+	hashesA, hashesB, headersA, headersB, blocksA, blocksB, receiptsA, receiptsB := makeChainFork(common+fork, fork, genesis, nil, true)
+
+	tester := newTester()
+	tester.newPeer("original", protocol, hashesA, headersA, blocksA, receiptsA)
+	tester.newPeer("rewriter", protocol, hashesB, headersB, blocksB, receiptsB)
+
+	// Synchronise with the peer and make sure all blocks were retrieved
+	if err := tester.sync("original", nil, mode); err != nil {
+		t.Fatalf("failed to synchronise blocks: %v", err)
+	}
+	assertOwnChain(t, tester, common+fork+1)
+
+	// Synchronise with the second peer and ensure that the fork is rejected to being too old
+	if err := tester.sync("rewriter", nil, mode); err != errInvalidAncestor {
+		t.Fatalf("sync failure mismatch: have %v, want %v", err, errInvalidAncestor)
+	}
+}
+
+// Tests that chain forks are contained within a certain interval of the current
+// chain head for short but heavy forks too. These are a bit special because they
+// take different ancestor lookup paths.
+func TestBoundedHeavyForkedSync61(t *testing.T)      { testBoundedHeavyForkedSync(t, 61, FullSync) }
+func TestBoundedHeavyForkedSync62(t *testing.T)      { testBoundedHeavyForkedSync(t, 62, FullSync) }
+func TestBoundedHeavyForkedSync63Full(t *testing.T)  { testBoundedHeavyForkedSync(t, 63, FullSync) }
+func TestBoundedHeavyForkedSync63Fast(t *testing.T)  { testBoundedHeavyForkedSync(t, 63, FastSync) }
+func TestBoundedHeavyForkedSync64Full(t *testing.T)  { testBoundedHeavyForkedSync(t, 64, FullSync) }
+func TestBoundedHeavyForkedSync64Fast(t *testing.T)  { testBoundedHeavyForkedSync(t, 64, FastSync) }
+func TestBoundedHeavyForkedSync64Light(t *testing.T) { testBoundedHeavyForkedSync(t, 64, LightSync) }
+
+func testBoundedHeavyForkedSync(t *testing.T, protocol int, mode SyncMode) {
+	t.Parallel()
+
+	// Create a long enough forked chain
+	common, fork := 13, int(MaxForkAncestry+17)
+	hashesA, hashesB, headersA, headersB, blocksA, blocksB, receiptsA, receiptsB := makeChainFork(common+fork, fork, genesis, nil, false)
+
+	tester := newTester()
+	tester.newPeer("original", protocol, hashesA, headersA, blocksA, receiptsA)
+	tester.newPeer("heavy-rewriter", protocol, hashesB[MaxForkAncestry-17:], headersB, blocksB, receiptsB) // Root the fork below the ancestor limit
+
+	// Synchronise with the peer and make sure all blocks were retrieved
+	if err := tester.sync("original", nil, mode); err != nil {
+		t.Fatalf("failed to synchronise blocks: %v", err)
+	}
+	assertOwnChain(t, tester, common+fork+1)
+
+	// Synchronise with the second peer and ensure that the fork is rejected to being too old
+	if err := tester.sync("heavy-rewriter", nil, mode); err != errInvalidAncestor {
+		t.Fatalf("sync failure mismatch: have %v, want %v", err, errInvalidAncestor)
+	}
+}
+
 // Tests that an inactive downloader will not accept incoming block headers and
 // bodies.
 func TestInactiveDownloader62(t *testing.T) {
@@ -909,7 +1020,7 @@ func testCancel(t *testing.T, protocol int, mode SyncMode) {
 	if targetBlocks >= MaxHeaderFetch {
 		targetBlocks = MaxHeaderFetch - 15
 	}
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 	tester.newPeer("peer", protocol, hashes, headers, blocks, receipts)
@@ -944,7 +1055,7 @@ func testMultiSynchronisation(t *testing.T, protocol int, mode SyncMode) {
 	// Create various peers with various parts of the chain
 	targetPeers := 8
 	targetBlocks := targetPeers*blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 	for i := 0; i < targetPeers; i++ {
@@ -972,7 +1083,7 @@ func testMultiProtoSync(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	// Create peers of every type
 	tester := newTester()
@@ -1010,7 +1121,7 @@ func testEmptyShortCircuit(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a block chain to download
 	targetBlocks := 2*blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 	tester.newPeer("peer", protocol, hashes, headers, blocks, receipts)
@@ -1063,7 +1174,7 @@ func testMissingHeaderAttack(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 
@@ -1095,7 +1206,7 @@ func TestShiftedHeaderAttack64Light(t *testing.T) { testShiftedHeaderAttack(t, 6
 func testShiftedHeaderAttack(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 
@@ -1126,7 +1237,7 @@ func TestInvalidHeaderRollback64Light(t *testing.T) { testInvalidHeaderRollback(
 func testInvalidHeaderRollback(t *testing.T, protocol int, mode SyncMode) {
 	// Create a small enough block chain to download
 	targetBlocks := 3*fsHeaderSafetyNet + fsMinFullBlocks
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	tester := newTester()
 
@@ -1217,7 +1328,7 @@ func testHighTDStarvationAttack(t *testing.T, protocol int, mode SyncMode) {
 	t.Parallel()
 
 	tester := newTester()
-	hashes, headers, blocks, receipts := makeChain(0, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(0, 0, genesis, nil, false)
 
 	tester.newPeer("attack", protocol, []common.Hash{hashes[0]}, headers, blocks, receipts)
 	if err := tester.sync("attack", big.NewInt(1000000), mode); err != errStallingPeer {
@@ -1247,6 +1358,7 @@ func testBlockHeaderAttackerDropping(t *testing.T, protocol int) {
 		{errEmptyHashSet, true},        // No hashes were returned as a response, drop as it's a dead end
 		{errEmptyHeaderSet, true},      // No headers were returned as a response, drop as it's a dead end
 		{errPeersUnavailable, true},    // Nobody had the advertised blocks, drop the advertiser
+		{errInvalidAncestor, true},     // Agreed upon ancestor is not acceptable, drop the chain rewriter
 		{errInvalidChain, true},        // Hash chain was detected as invalid, definitely drop
 		{errInvalidBlock, false},       // A bad peer was detected, but not the sync origin
 		{errInvalidBody, false},        // A bad peer was detected, but not the sync origin
@@ -1294,7 +1406,7 @@ func testSyncProgress(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	// Set a sync init hook to catch progress changes
 	starting := make(chan struct{})
@@ -1366,7 +1478,7 @@ func testForkedSyncProgress(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a forked chain to simulate origin revertal
 	common, fork := MaxHashFetch, 2*MaxHashFetch
-	hashesA, hashesB, headersA, headersB, blocksA, blocksB, receiptsA, receiptsB := makeChainFork(common+fork, fork, genesis, nil)
+	hashesA, hashesB, headersA, headersB, blocksA, blocksB, receiptsA, receiptsB := makeChainFork(common+fork, fork, genesis, nil, true)
 
 	// Set a sync init hook to catch progress changes
 	starting := make(chan struct{})
@@ -1441,7 +1553,7 @@ func testFailedSyncProgress(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a small enough block chain to download
 	targetBlocks := blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks, 0, genesis, nil, false)
 
 	// Set a sync init hook to catch progress changes
 	starting := make(chan struct{})
@@ -1517,7 +1629,7 @@ func testFakedSyncProgress(t *testing.T, protocol int, mode SyncMode) {
 
 	// Create a small block chain
 	targetBlocks := blockCacheLimit - 15
-	hashes, headers, blocks, receipts := makeChain(targetBlocks+3, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(targetBlocks+3, 0, genesis, nil, false)
 
 	// Set a sync init hook to catch progress changes
 	starting := make(chan struct{})
@@ -1590,7 +1702,7 @@ func TestDeliverHeadersHang64Light(t *testing.T) { testDeliverHeadersHang(t, 64,
 
 func testDeliverHeadersHang(t *testing.T, protocol int, mode SyncMode) {
 	t.Parallel()
-	hashes, headers, blocks, receipts := makeChain(5, 0, genesis, nil)
+	hashes, headers, blocks, receipts := makeChain(5, 0, genesis, nil, false)
 	fakeHeads := []*types.Header{{}, {}, {}, {}}
 	for i := 0; i < 200; i++ {
 		tester := newTester()

eth/handler.go

@@ -22,6 +22,7 @@ import (
 	"math"
 	"math/big"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -58,7 +59,7 @@ type blockFetcherFn func([]common.Hash) error
 type ProtocolManager struct {
 	networkId int
 
-	fastSync   bool
+	fastSync   uint32
 	txpool     txPool
 	blockchain *core.BlockChain
 	chaindb    ethdb.Database
@@ -74,36 +75,39 @@ type ProtocolManager struct {
 	minedBlockSub event.Subscription
 
 	// channels for fetcher, syncer, txsyncLoop
-	newPeerCh chan *peer
-	txsyncCh  chan *txsync
-	quitSync  chan struct{}
+	newPeerCh   chan *peer
+	txsyncCh    chan *txsync
+	quitSync    chan struct{}
+	noMorePeers chan struct{}
 
 	// wait group is used for graceful shutdowns during downloading
 	// and processing
-	wg   sync.WaitGroup
-	quit bool
+	wg sync.WaitGroup
 }
 
 // NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
 // with the ethereum network.
 func NewProtocolManager(config *core.ChainConfig, fastSync bool, networkId int, mux *event.TypeMux, txpool txPool, pow pow.PoW, blockchain *core.BlockChain, chaindb ethdb.Database) (*ProtocolManager, error) {
+	// Create the protocol manager with the base fields
+	manager := &ProtocolManager{
+		networkId:   networkId,
+		eventMux:    mux,
+		txpool:      txpool,
+		blockchain:  blockchain,
+		chaindb:     chaindb,
+		peers:       newPeerSet(),
+		newPeerCh:   make(chan *peer),
+		noMorePeers: make(chan struct{}),
+		txsyncCh:    make(chan *txsync),
+		quitSync:    make(chan struct{}),
+	}
 	// Figure out whether to allow fast sync or not
 	if fastSync && blockchain.CurrentBlock().NumberU64() > 0 {
 		glog.V(logger.Info).Infof("blockchain not empty, fast sync disabled")
 		fastSync = false
 	}
-	// Create the protocol manager with the base fields
-	manager := &ProtocolManager{
-		networkId:  networkId,
-		fastSync:   fastSync,
-		eventMux:   mux,
-		txpool:     txpool,
-		blockchain: blockchain,
-		chaindb:    chaindb,
-		peers:      newPeerSet(),
-		newPeerCh:  make(chan *peer, 1),
-		txsyncCh:   make(chan *txsync),
-		quitSync:   make(chan struct{}),
+	if fastSync {
+		manager.fastSync = uint32(1)
 	}
 	// Initiate a sub-protocol for every implemented version we can handle
 	manager.SubProtocols = make([]p2p.Protocol, 0, len(ProtocolVersions))
@@ -120,8 +124,14 @@ func NewProtocolManager(config *core.ChainConfig, fastSync bool, networkId int,
 			Length:  ProtocolLengths[i],
 			Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
 				peer := manager.newPeer(int(version), p, rw)
-				manager.newPeerCh <- peer
-				return manager.handle(peer)
+				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()
@@ -187,16 +197,25 @@ func (pm *ProtocolManager) Start() {
 }
 
 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 ethereum protocol handler...")
 
-	pm.quit = true
 	pm.txSub.Unsubscribe()         // quits txBroadcastLoop
 	pm.minedBlockSub.Unsubscribe() // quits blockBroadcastLoop
-	close(pm.quitSync)             // quits syncer, fetcher, txsyncLoop
 
-	// Wait for any process action
+	// Quit the sync loop.
+	// After this send has completed, no new peers will be accepted.
+	pm.noMorePeers <- struct{}{}
+
+	// Quit fetcher, txsyncLoop.
+	close(pm.quitSync)
+
+	// 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 all peer handler goroutines and the loops to come down.
 	pm.wg.Wait()
 
 	glog.V(logger.Info).Infoln("Ethereum protocol handler stopped")
@@ -662,7 +681,11 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		}
 
 	case msg.Code == TxMsg:
-		// Transactions arrived, parse all of them and deliver to the pool
+		// Transactions arrived, make sure we have a valid chain to handle them
+		if atomic.LoadUint32(&pm.fastSync) == 1 {
+			break
+		}
+		// Transactions can be processed, 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)

eth/helper_test.go

@@ -140,14 +140,14 @@ func newTestPeer(name string, version int, pm *ProtocolManager, shake bool) (*te
 	// Start the peer on a new thread
 	errc := make(chan error, 1)
 	go func() {
-		pm.newPeerCh <- peer
-		errc <- pm.handle(peer)
+		select {
+		case pm.newPeerCh <- peer:
+			errc <- pm.handle(peer)
+		case <-pm.quitSync:
+			errc <- p2p.DiscQuitting
+		}
 	}()
-	tp := &testPeer{
-		app:  app,
-		net:  net,
-		peer: peer,
-	}
+	tp := &testPeer{app: app, net: net, peer: peer}
 	// Execute any implicitly requested handshakes and return
 	if shake {
 		td, head, genesis := pm.blockchain.Status()

eth/peer.go

@@ -34,6 +34,7 @@ import (
 )
 
 var (
+	errClosed            = errors.New("peer set is closed")
 	errAlreadyRegistered = errors.New("peer is already registered")
 	errNotRegistered     = errors.New("peer is not registered")
 )
@@ -351,8 +352,9 @@ func (p *peer) String() string {
 // peerSet represents the collection of active peers currently participating in
 // the Ethereum sub-protocol.
 type peerSet struct {
-	peers map[string]*peer
-	lock  sync.RWMutex
+	peers  map[string]*peer
+	lock   sync.RWMutex
+	closed bool
 }
 
 // newPeerSet creates a new peer set to track the active participants.
@@ -368,6 +370,9 @@ 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
 	}
@@ -450,3 +455,15 @@ func (ps *peerSet) BestPeer() *peer {
 	}
 	return bestPeer
 }
+
+// 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
+}

eth/sync.go

@@ -18,6 +18,7 @@ package eth
 
 import (
 	"math/rand"
+	"sync/atomic"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -148,7 +149,7 @@ func (pm *ProtocolManager) syncer() {
 			// Force a sync even if not enough peers are present
 			go pm.synchronise(pm.peers.BestPeer())
 
-		case <-pm.quitSync:
+		case <-pm.noMorePeers:
 			return
 		}
 	}
@@ -167,18 +168,18 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
 	}
 	// Otherwise try to sync with the downloader
 	mode := downloader.FullSync
-	if pm.fastSync {
+	if atomic.LoadUint32(&pm.fastSync) == 1 {
 		mode = downloader.FastSync
 	}
 	if err := pm.downloader.Synchronise(peer.id, peer.Head(), peer.Td(), mode); err != nil {
 		return
 	}
 	// If fast sync was enabled, and we synced up, disable it
-	if pm.fastSync {
+	if atomic.LoadUint32(&pm.fastSync) == 1 {
 		// Disable fast sync if we indeed have something in our chain
 		if pm.blockchain.CurrentBlock().NumberU64() > 0 {
 			glog.V(logger.Info).Infof("fast sync complete, auto disabling")
-			pm.fastSync = false
+			atomic.StoreUint32(&pm.fastSync, 0)
 		}
 	}
 }

eth/sync_test.go

@@ -17,6 +17,7 @@
 package eth
 
 import (
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -29,12 +30,12 @@ import (
 func TestFastSyncDisabling(t *testing.T) {
 	// Create a pristine protocol manager, check that fast sync is left enabled
 	pmEmpty := newTestProtocolManagerMust(t, true, 0, nil, nil)
-	if !pmEmpty.fastSync {
+	if atomic.LoadUint32(&pmEmpty.fastSync) == 0 {
 		t.Fatalf("fast sync disabled on pristine blockchain")
 	}
 	// Create a full protocol manager, check that fast sync gets disabled
 	pmFull := newTestProtocolManagerMust(t, true, 1024, nil, nil)
-	if pmFull.fastSync {
+	if atomic.LoadUint32(&pmFull.fastSync) == 1 {
 		t.Fatalf("fast sync not disabled on non-empty blockchain")
 	}
 	// Sync up the two peers
@@ -47,7 +48,7 @@ func TestFastSyncDisabling(t *testing.T) {
 	pmEmpty.synchronise(pmEmpty.peers.BestPeer())
 
 	// Check that fast sync was disabled
-	if pmEmpty.fastSync {
+	if atomic.LoadUint32(&pmEmpty.fastSync) == 1 {
 		t.Fatalf("fast sync not disabled after successful synchronisation")
 	}
 }

event/event.go

@@ -66,6 +66,9 @@ func (mux *TypeMux) Subscribe(types ...interface{}) Subscription {
 	mux.mutex.Lock()
 	defer mux.mutex.Unlock()
 	if mux.stopped {
+		// set the status to closed so that calling Unsubscribe after this
+		// call will short curuit
+		sub.closed = true
 		close(sub.postC)
 	} else {
 		if mux.subm == nil {

event/event_test.go

@@ -25,6 +25,14 @@ import (
 
 type testEvent int
 
+func TestSubCloseUnsub(t *testing.T) {
+	// the point of this test is **not** to panic
+	var mux TypeMux
+	mux.Stop()
+	sub := mux.Subscribe(int(0))
+	sub.Unsubscribe()
+}
+
 func TestSub(t *testing.T) {
 	mux := new(TypeMux)
 	defer mux.Stop()

internal/debug/api.go

@@ -51,7 +51,7 @@ type HandlerT struct {
 	traceFile string
 }
 
-// Verbosity sets the glog verbosity floor.
+// Verbosity sets the glog verbosity ceiling.
 // The verbosity of individual packages and source files
 // can be raised using Vmodule.
 func (*HandlerT) Verbosity(level int) {
@@ -131,14 +131,14 @@ func (h *HandlerT) StopCPUProfile() error {
 	return nil
 }
 
-// Trace turns on tracing for nsec seconds and writes
+// GoTrace turns on tracing for nsec seconds and writes
 // trace data to file.
-func (h *HandlerT) Trace(file string, nsec uint) error {
-	if err := h.StartTrace(file); err != nil {
+func (h *HandlerT) GoTrace(file string, nsec uint) error {
+	if err := h.StartGoTrace(file); err != nil {
 		return err
 	}
 	time.Sleep(time.Duration(nsec) * time.Second)
-	h.StopTrace()
+	h.StopGoTrace()
 	return nil
 }
 

internal/debug/flags.go

@@ -89,7 +89,7 @@ func Setup(ctx *cli.Context) error {
 	runtime.MemProfileRate = ctx.GlobalInt(memprofilerateFlag.Name)
 	Handler.SetBlockProfileRate(ctx.GlobalInt(blockprofilerateFlag.Name))
 	if traceFile := ctx.GlobalString(traceFlag.Name); traceFile != "" {
-		if err := Handler.StartTrace(traceFile); err != nil {
+		if err := Handler.StartGoTrace(traceFile); err != nil {
 			return err
 		}
 	}
@@ -114,5 +114,5 @@ func Setup(ctx *cli.Context) error {
 // respective file.
 func Exit() {
 	Handler.StopCPUProfile()
-	Handler.StopTrace()
+	Handler.StopGoTrace()
 }

internal/debug/trace.go

@@ -27,8 +27,8 @@ import (
 	"github.com/ethereum/go-ethereum/logger/glog"
 )
 
-// StartTrace turns on tracing, writing to the given file.
-func (h *HandlerT) StartTrace(file string) error {
+// StartGoTrace turns on tracing, writing to the given file.
+func (h *HandlerT) StartGoTrace(file string) error {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 	if h.traceW != nil {
@@ -49,7 +49,7 @@ func (h *HandlerT) StartTrace(file string) error {
 }
 
 // StopTrace stops an ongoing trace.
-func (h *HandlerT) StopTrace() error {
+func (h *HandlerT) StopGoTrace() error {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 	trace.Stop()

internal/debug/trace_fallback.go

@@ -22,10 +22,10 @@ package debug
 
 import "errors"
 
-func (*HandlerT) StartTrace(string) error {
+func (*HandlerT) StartGoTrace(string) error {
 	return errors.New("tracing is not supported on Go < 1.5")
 }
 
-func (*HandlerT) StopTrace() error {
+func (*HandlerT) StopGoTrace() error {
 	return errors.New("tracing is not supported on Go < 1.5")
 }

internal/web3ext/web3ext.go

@@ -366,18 +366,18 @@ web3._extend({
 			params: 0
 		}),
 		new web3._extend.Method({
-			name: 'trace',
-			call: 'debug_trace',
+			name: 'goTrace',
+			call: 'debug_goTrace',
 			params: 2
 		}),
 		new web3._extend.Method({
-			name: 'startTrace',
-			call: 'debug_startTrace',
+			name: 'startGoTrace',
+			call: 'debug_startGoTrace',
 			params: 1
 		}),
 		new web3._extend.Method({
-			name: 'stopTrace',
-			call: 'debug_stopTrace',
+			name: 'stopGoTrace',
+			call: 'debug_stopGoTrace',
 			params: 0
 		}),
 		new web3._extend.Method({

jsre/ethereum_js.go

@@ -3911,7 +3911,12 @@ var outputSyncingFormatter = function(result) {
     result.startingBlock = utils.toDecimal(result.startingBlock);
     result.currentBlock = utils.toDecimal(result.currentBlock);
     result.highestBlock = utils.toDecimal(result.highestBlock);
-
+    if (result.knownStates !== undefined) {
+      result.knownStates = utils.toDecimal(result.knownStates);
+    }
+    if (result.pulledStates !== undefined) {
+      result.pulledStates = utils.toDecimal(result.pulledStates);
+    }
     return result;
 };
 

miner/worker.go

@@ -94,10 +94,13 @@ type worker struct {
 
 	mu sync.Mutex
 
+	// update loop
+	mux    *event.TypeMux
+	events event.Subscription
+	wg     sync.WaitGroup
+
 	agents map[Agent]struct{}
 	recv   chan *Result
-	mux    *event.TypeMux
-	quit   chan struct{}
 	pow    pow.PoW
 
 	eth     core.Backend
@@ -138,13 +141,13 @@ func newWorker(config *core.ChainConfig, coinbase common.Address, eth core.Backe
 		possibleUncles: make(map[common.Hash]*types.Block),
 		coinbase:       coinbase,
 		txQueue:        make(map[common.Hash]*types.Transaction),
-		quit:           make(chan struct{}),
 		agents:         make(map[Agent]struct{}),
 		fullValidation: false,
 	}
+	worker.events = worker.mux.Subscribe(core.ChainHeadEvent{}, core.ChainSideEvent{}, core.TxPreEvent{})
 	go worker.update()
-	go worker.wait()
 
+	go worker.wait()
 	worker.commitNewWork()
 
 	return worker
@@ -184,9 +187,10 @@ func (self *worker) start() {
 }
 
 func (self *worker) stop() {
+	self.wg.Wait()
+
 	self.mu.Lock()
 	defer self.mu.Unlock()
-
 	if atomic.LoadInt32(&self.mining) == 1 {
 		// Stop all agents.
 		for agent := range self.agents {
@@ -217,36 +221,22 @@ func (self *worker) unregister(agent Agent) {
 }
 
 func (self *worker) update() {
-	eventSub := self.mux.Subscribe(core.ChainHeadEvent{}, core.ChainSideEvent{}, core.TxPreEvent{})
-	defer eventSub.Unsubscribe()
-
-	eventCh := eventSub.Chan()
-	for {
-		select {
-		case event, ok := <-eventCh:
-			if !ok {
-				// Event subscription closed, set the channel to nil to stop spinning
-				eventCh = nil
-				continue
+	for event := range self.events.Chan() {
+		// A real event arrived, process interesting content
+		switch ev := event.Data.(type) {
+		case core.ChainHeadEvent:
+			self.commitNewWork()
+		case core.ChainSideEvent:
+			self.uncleMu.Lock()
+			self.possibleUncles[ev.Block.Hash()] = ev.Block
+			self.uncleMu.Unlock()
+		case core.TxPreEvent:
+			// Apply transaction to the pending state if we're not mining
+			if atomic.LoadInt32(&self.mining) == 0 {
+				self.currentMu.Lock()
+				self.current.commitTransactions(self.mux, types.Transactions{ev.Tx}, self.gasPrice, self.chain)
+				self.currentMu.Unlock()
 			}
-			// A real event arrived, process interesting content
-			switch ev := event.Data.(type) {
-			case core.ChainHeadEvent:
-				self.commitNewWork()
-			case core.ChainSideEvent:
-				self.uncleMu.Lock()
-				self.possibleUncles[ev.Block.Hash()] = ev.Block
-				self.uncleMu.Unlock()
-			case core.TxPreEvent:
-				// Apply transaction to the pending state if we're not mining
-				if atomic.LoadInt32(&self.mining) == 0 {
-					self.currentMu.Lock()
-					self.current.commitTransactions(self.mux, types.Transactions{ev.Tx}, self.gasPrice, self.chain)
-					self.currentMu.Unlock()
-				}
-			}
-		case <-self.quit:
-			return
 		}
 	}
 }

node/api.go

@@ -68,7 +68,11 @@ func (api *PrivateAdminAPI) StartRPC(host *string, port *rpc.HexNumber, cors *st
 	}
 
 	if host == nil {
-		host = &api.node.httpHost
+		h := common.DefaultHTTPHost
+		if api.node.httpHost != "" {
+			h = api.node.httpHost
+		}
+		host = &h
 	}
 	if port == nil {
 		port = rpc.NewHexNumber(api.node.httpPort)
@@ -113,7 +117,11 @@ func (api *PrivateAdminAPI) StartWS(host *string, port *rpc.HexNumber, allowedOr
 	}
 
 	if host == nil {
-		host = &api.node.wsHost
+		h := common.DefaultWSHost
+		if api.node.wsHost != "" {
+			h = api.node.wsHost
+		}
+		host = &h
 	}
 	if port == nil {
 		port = rpc.NewHexNumber(api.node.wsPort)

rpc/websocket.go

@@ -61,22 +61,22 @@ func wsHandshakeValidator(allowedOrigins []string) func(*websocket.Config, *http
 			allowAllOrigins = true
 		}
 		if origin != "" {
-			origins.Add(origin)
+			origins.Add(strings.ToLower(origin))
 		}
 	}
 
-	// allow localhost if no allowedOrigins are specified
+	// allow localhost if no allowedOrigins are specified.
 	if len(origins.List()) == 0 {
 		origins.Add("http://localhost")
 		if hostname, err := os.Hostname(); err == nil {
-			origins.Add("http://" + hostname)
+			origins.Add("http://" + strings.ToLower(hostname))
 		}
 	}
 
 	glog.V(logger.Debug).Infof("Allowed origin(s) for WS RPC interface %v\n", origins.List())
 
 	f := func(cfg *websocket.Config, req *http.Request) error {
-		origin := req.Header.Get("Origin")
+		origin := strings.ToLower(req.Header.Get("Origin"))
 		if allowAllOrigins || origins.Has(origin) {
 			return nil
 		}