light: implemented light chain, VM env and tx pool

2026-07-24 13:46:43 +00:00 · 2016-01-13 19:35:48 +01:00 · 2016-01-13 19:35:48 +01:00 · 2aac139b72
commit 2aac139b72
parent 4908bf6487
15 changed files with 2340 additions and 83 deletions
--- a/core/database_util.go
+++ b/core/database_util.go
@ -288,8 +288,13 @@ func WriteBody(db ethdb.Database, hash common.Hash, body *types.Body) error {
 	if err != nil {
 		return err
 	}
+	return WriteBodyRLP(db, hash, data)
+}
+
+// WriteBodyRLP writes a serialized body of a block into the database.
+func WriteBodyRLP(db ethdb.Database, hash common.Hash, rlp rlp.RawValue) error {
 	key := append(append(blockPrefix, hash.Bytes()...), bodySuffix...)
-	if err := db.Put(key, data); err != nil {
+	if err := db.Put(key, rlp); err != nil {
 		glog.Fatalf("failed to store block body into database: %v", err)
 		return err
 	}
--- a/core/types/block.go
+++ b/core/types/block.go
@ -70,6 +70,15 @@ type Header struct {
 	Nonce       BlockNonce
 }

+func (h *Header) GetNumber() *big.Int     { return new(big.Int).Set(h.Number) }
+func (h *Header) GetGasLimit() *big.Int   { return new(big.Int).Set(h.GasLimit) }
+func (h *Header) GetGasUsed() *big.Int    { return new(big.Int).Set(h.GasUsed) }
+func (h *Header) GetDifficulty() *big.Int { return new(big.Int).Set(h.Difficulty) }
+func (h *Header) GetTime() *big.Int       { return new(big.Int).Set(h.Time) }
+func (h *Header) GetNumberU64() uint64    { return h.Number.Uint64() }
+func (h *Header) GetNonce() uint64        { return binary.BigEndian.Uint64(h.Nonce[:]) }
+func (h *Header) GetExtra() []byte        { return common.CopyBytes(h.Extra) }
+
 func (h *Header) Hash() common.Hash {
 	return rlpHash(h)
 }
--- a/light/events.go
+++ b/light/events.go
@ -0,0 +1,33 @@
+// 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
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+type LightChainSplitEvent struct{ Header *types.Header }
+
+type LightChainEvent struct {
+	Header *types.Header
+	Hash   common.Hash
+}
+
+type LightChainSideEvent struct{ Header *types.Header }
+
+type LightChainHeadEvent struct{ Header *types.Header }
--- a/light/lightchain.go
+++ b/light/lightchain.go
@ -0,0 +1,430 @@
+// 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
+
+import (
+	"math/big"
+	"sync"
+	"sync/atomic"
+	"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/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/pow"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/hashicorp/golang-lru"
+	"golang.org/x/net/context"
+)
+
+var (
+	bodyCacheLimit  = 256
+	blockCacheLimit = 256
+)
+
+// LightChain represents a canonical chain that by default only handles block
+// headers, downloading block bodies and receipts on demand through an ODR
+// interface. It only does header validation during chain insertion.
+type LightChain struct {
+	hc           *core.HeaderChain
+	chainDb      ethdb.Database
+	odr          OdrBackend
+	eventMux     *event.TypeMux
+	genesisBlock *types.Block
+
+	mu      sync.RWMutex
+	chainmu sync.RWMutex
+	procmu  sync.RWMutex
+
+	bodyCache    *lru.Cache // Cache for the most recent block bodies
+	bodyRLPCache *lru.Cache // Cache for the most recent block bodies in RLP encoded format
+	blockCache   *lru.Cache // Cache for the most recent entire blocks
+
+	quit    chan struct{}
+	running int32 // running must be called automically
+	// procInterrupt must be atomically called
+	procInterrupt int32 // interrupt signaler for block processing
+	wg            sync.WaitGroup
+
+	pow       pow.PoW
+	validator core.HeaderValidator
+}
+
+// NewLightChain returns a fully initialised light chain using information
+// available in the database. It initialises the default Ethereum header
+// validator.
+func NewLightChain(odr OdrBackend, pow pow.PoW, mux *event.TypeMux) (*LightChain, error) {
+	bodyCache, _ := lru.New(bodyCacheLimit)
+	bodyRLPCache, _ := lru.New(bodyCacheLimit)
+	blockCache, _ := lru.New(blockCacheLimit)
+
+	bc := &LightChain{
+		chainDb:      odr.Database(),
+		odr:          odr,
+		eventMux:     mux,
+		quit:         make(chan struct{}),
+		bodyCache:    bodyCache,
+		bodyRLPCache: bodyRLPCache,
+		blockCache:   blockCache,
+		pow:          pow,
+	}
+
+	var err error
+	bc.hc, err = core.NewHeaderChain(odr.Database(), bc.Validator, bc.getProcInterrupt)
+	bc.SetValidator(core.NewHeaderValidator(bc.hc, pow))
+	if err != nil {
+		return nil, err
+	}
+
+	bc.genesisBlock, _ = bc.GetBlockByNumber(NoOdr, 0)
+	if bc.genesisBlock == nil {
+		bc.genesisBlock, err = core.WriteDefaultGenesisBlock(odr.Database())
+		if err != nil {
+			return nil, err
+		}
+		glog.V(logger.Info).Infoln("WARNING: Wrote default ethereum genesis block")
+	}
+	if err := bc.loadLastState(); err != nil {
+		return nil, err
+	}
+	// Check the current state of the block hashes and make sure that we do not have any of the bad blocks in our chain
+	for hash, _ := range core.BadHashes {
+		if header := bc.GetHeader(hash); header != nil {
+			glog.V(logger.Error).Infof("Found bad hash, rewinding chain to block #%d [%x…]", header.Number, header.ParentHash[:4])
+			bc.SetHead(header.Number.Uint64() - 1)
+			glog.V(logger.Error).Infoln("Chain rewind was successful, resuming normal operation")
+		}
+	}
+	return bc, nil
+}
+
+func (self *LightChain) getProcInterrupt() bool {
+	return atomic.LoadInt32(&self.procInterrupt) == 1
+}
+
+// Odr returns the ODR backend of the chain
+func (self *LightChain) Odr() OdrBackend {
+	return self.odr
+}
+
+// loadLastState loads the last known chain state from the database. This method
+// assumes that the chain manager mutex is held.
+func (self *LightChain) loadLastState() error {
+	if head := core.GetHeadHeaderHash(self.chainDb); head == (common.Hash{}) {
+		// Corrupt or empty database, init from scratch
+		self.Reset()
+	} else {
+		if header := self.GetHeader(head); header != nil {
+			self.hc.SetCurrentHeader(header)
+		}
+	}
+
+	// Issue a status log and return
+	headerTd := self.GetTd(self.hc.CurrentHeader().Hash())
+	glog.V(logger.Info).Infof("Last header: #%d [%x…] TD=%v", self.hc.CurrentHeader().Number, self.hc.CurrentHeader().Hash().Bytes()[:4], headerTd)
+
+	return nil
+}
+
+// SetHead rewinds the local chain to a new head. Everything above the new
+// head will be deleted and the new one set.
+func (bc *LightChain) SetHead(head uint64) {
+	bc.mu.Lock()
+	defer bc.mu.Unlock()
+
+	bc.hc.SetHead(head)
+	bc.loadLastState()
+}
+
+// GasLimit returns the gas limit of the current HEAD block.
+func (self *LightChain) GasLimit() *big.Int {
+	self.mu.RLock()
+	defer self.mu.RUnlock()
+
+	return self.hc.CurrentHeader().GasLimit
+}
+
+// LastBlockHash return the hash of the HEAD block.
+func (self *LightChain) LastBlockHash() common.Hash {
+	self.mu.RLock()
+	defer self.mu.RUnlock()
+
+	return self.hc.CurrentHeader().Hash()
+}
+
+// Status returns status information about the current chain such as the HEAD Td,
+// the HEAD hash and the hash of the genesis block.
+func (self *LightChain) Status() (td *big.Int, currentBlock common.Hash, genesisBlock common.Hash) {
+	self.mu.RLock()
+	defer self.mu.RUnlock()
+
+	hash := self.hc.CurrentHeader().Hash()
+	return self.GetTd(hash), hash, self.genesisBlock.Hash()
+}
+
+// SetValidator sets the validator which is used to validate incoming headers.
+func (self *LightChain) SetValidator(validator core.HeaderValidator) {
+	self.procmu.Lock()
+	defer self.procmu.Unlock()
+	self.validator = validator
+}
+
+// Validator returns the current header validator.
+func (self *LightChain) Validator() core.HeaderValidator {
+	self.procmu.RLock()
+	defer self.procmu.RUnlock()
+	return self.validator
+}
+
+// State returns a new mutable state based on the current HEAD block.
+func (self *LightChain) State() *LightState {
+	return NewLightState(StateTrieID(self.hc.CurrentHeader()), self.odr)
+}
+
+// Reset purges the entire blockchain, restoring it to its genesis state.
+func (bc *LightChain) Reset() {
+	bc.ResetWithGenesisBlock(bc.genesisBlock)
+}
+
+// ResetWithGenesisBlock purges the entire blockchain, restoring it to the
+// specified genesis state.
+func (bc *LightChain) ResetWithGenesisBlock(genesis *types.Block) {
+	// Dump the entire block chain and purge the caches
+	bc.SetHead(0)
+
+	bc.mu.Lock()
+	defer bc.mu.Unlock()
+
+	// Prepare the genesis block and reinitialise the chain
+	if err := core.WriteTd(bc.chainDb, genesis.Hash(), genesis.Difficulty()); err != nil {
+		glog.Fatalf("failed to write genesis block TD: %v", err)
+	}
+	if err := core.WriteBlock(bc.chainDb, genesis); err != nil {
+		glog.Fatalf("failed to write genesis block: %v", err)
+	}
+	bc.genesisBlock = genesis
+	bc.hc.SetGenesis(bc.genesisBlock.Header())
+	bc.hc.SetCurrentHeader(bc.genesisBlock.Header())
+}
+
+// Accessors
+
+// Genesis returns the genesis block
+func (bc *LightChain) Genesis() *types.Block {
+	return bc.genesisBlock
+}
+
+// GetBody retrieves a block body (transactions and uncles) from the database
+// or ODR service by hash, caching it if found.
+func (self *LightChain) GetBody(ctx context.Context, hash common.Hash) (*types.Body, error) {
+	// Short circuit if the body's already in the cache, retrieve otherwise
+	if cached, ok := self.bodyCache.Get(hash); ok {
+		body := cached.(*types.Body)
+		return body, nil
+	}
+	body, err := GetBody(ctx, self.odr, hash)
+	if err != nil {
+		return nil, err
+	}
+	// Cache the found body for next time and return
+	self.bodyCache.Add(hash, body)
+	return body, nil
+}
+
+// GetBodyRLP retrieves a block body in RLP encoding from the database or
+// ODR service by hash, caching it if found.
+func (self *LightChain) GetBodyRLP(ctx context.Context, hash common.Hash) (rlp.RawValue, error) {
+	// Short circuit if the body's already in the cache, retrieve otherwise
+	if cached, ok := self.bodyRLPCache.Get(hash); ok {
+		return cached.(rlp.RawValue), nil
+	}
+	body, err := GetBodyRLP(ctx, self.odr, hash)
+	if err != nil {
+		return nil, err
+	}
+	// Cache the found body for next time and return
+	self.bodyRLPCache.Add(hash, body)
+	return body, nil
+}
+
+// HasBlock checks if a block is fully present in the database or not, caching
+// it if present.
+func (bc *LightChain) HasBlock(hash common.Hash) bool {
+	blk, _ := bc.GetBlock(NoOdr, hash)
+	return blk != nil
+}
+
+// GetBlock retrieves a block from the database or ODR service by hash,
+// caching it if found.
+func (self *LightChain) GetBlock(ctx context.Context, hash common.Hash) (*types.Block, error) {
+	// Short circuit if the block's already in the cache, retrieve otherwise
+	if block, ok := self.blockCache.Get(hash); ok {
+		return block.(*types.Block), nil
+	}
+	block, err := GetBlock(ctx, self.odr, hash)
+	if err != nil {
+		return nil, err
+	}
+	// Cache the found block for next time and return
+	self.blockCache.Add(block.Hash(), block)
+	return block, nil
+}
+
+// GetBlockByNumber retrieves a block from the database or ODR service by
+// number, caching it (associated with its hash) if found.
+func (self *LightChain) GetBlockByNumber(ctx context.Context, number uint64) (*types.Block, error) {
+	hash := core.GetCanonicalHash(self.chainDb, number)
+	if hash == (common.Hash{}) {
+		return nil, nil
+	}
+	return self.GetBlock(ctx, hash)
+}
+
+// Stop stops the blockchain service. If any imports are currently in progress
+// it will abort them using the procInterrupt.
+func (bc *LightChain) Stop() {
+	if !atomic.CompareAndSwapInt32(&bc.running, 0, 1) {
+		return
+	}
+	close(bc.quit)
+	atomic.StoreInt32(&bc.procInterrupt, 1)
+
+	bc.wg.Wait()
+
+	glog.V(logger.Info).Infoln("Chain manager stopped")
+}
+
+// Rollback is designed to remove a chain of links from the database that aren't
+// certain enough to be valid.
+func (self *LightChain) Rollback(chain []common.Hash) {
+	self.mu.Lock()
+	defer self.mu.Unlock()
+
+	for i := len(chain) - 1; i >= 0; i-- {
+		hash := chain[i]
+
+		if self.hc.CurrentHeader().Hash() == hash {
+			self.hc.SetCurrentHeader(self.GetHeader(self.hc.CurrentHeader().ParentHash))
+		}
+	}
+}
+
+// postChainEvents iterates over the events generated by a chain insertion and
+// posts them into the event mux.
+func (self *LightChain) postChainEvents(events []interface{}) {
+	for _, event := range events {
+		if event, ok := event.(LightChainEvent); ok {
+			if self.LastBlockHash() == event.Hash {
+				self.eventMux.Post(LightChainHeadEvent{event.Header})
+			}
+		}
+		// Fire the insertion events individually too
+		self.eventMux.Post(event)
+	}
+}
+
+// InsertHeaderChain attempts to insert the given header chain in to the local
+// chain, possibly creating a reorg. If an error is returned, it will return the
+// index number of the failing header as well an error describing what went wrong.
+//
+// The verify parameter can be used to fine tune whether nonce verification
+// should be done or not. The reason behind the optional check is because some
+// of the header retrieval mechanisms already need to verfy nonces, as well as
+// because nonces can be verified sparsely, not needing to check each.
+//
+// In the case of a light chain, InsertHeaderChain also creates and posts light
+// chain events when necessary.
+func (self *LightChain) InsertHeaderChain(chain []*types.Header, checkFreq int) (int, error) {
+	// Make sure only one thread manipulates the chain at once
+	self.chainmu.Lock()
+	defer self.chainmu.Unlock()
+
+	self.wg.Add(1)
+	defer self.wg.Done()
+
+	var events []interface{}
+	whFunc := func(header *types.Header) error {
+		self.mu.Lock()
+		defer self.mu.Unlock()
+
+		status, err := self.hc.WriteHeader(header)
+
+		switch status {
+		case core.CanonStatTy:
+			if glog.V(logger.Debug) {
+				glog.Infof("[%v] inserted header #%d (%x...).\n", time.Now().UnixNano(), header.Number, header.Hash().Bytes()[0:4])
+			}
+			events = append(events, LightChainEvent{header, header.Hash()})
+
+		case core.SideStatTy:
+			if glog.V(logger.Detail) {
+				glog.Infof("inserted forked header #%d (TD=%v) (%x...).\n", header.Number, header.Difficulty, header.Hash().Bytes()[0:4])
+			}
+			events = append(events, LightChainSideEvent{header})
+
+		case core.SplitStatTy:
+			events = append(events, LightChainSplitEvent{header})
+		}
+
+		return err
+	}
+	i, err := self.hc.InsertHeaderChain(chain, checkFreq, whFunc)
+	go self.postChainEvents(events)
+	return i, err
+}
+
+// CurrentHeader retrieves the current head header of the canonical chain. The
+// header is retrieved from the HeaderChain's internal cache.
+func (self *LightChain) CurrentHeader() *types.Header {
+	self.mu.RLock()
+	defer self.mu.RUnlock()
+
+	return self.hc.CurrentHeader()
+}
+
+// GetTd retrieves a block's total difficulty in the canonical chain from the
+// database by hash, caching it if found.
+func (self *LightChain) GetTd(hash common.Hash) *big.Int {
+	return self.hc.GetTd(hash)
+}
+
+// GetHeader retrieves a block header from the database by hash, caching it if
+// found.
+func (self *LightChain) GetHeader(hash common.Hash) *types.Header {
+	return self.hc.GetHeader(hash)
+}
+
+// HasHeader checks if a block header is present in the database or not, caching
+// it if present.
+func (bc *LightChain) HasHeader(hash common.Hash) bool {
+	return bc.hc.HasHeader(hash)
+}
+
+// GetBlockHashesFromHash retrieves a number of block hashes starting at a given
+// hash, fetching towards the genesis block.
+func (self *LightChain) GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash {
+	return self.hc.GetBlockHashesFromHash(hash, max)
+}
+
+// GetHeaderByNumber retrieves a block header from the database by number,
+// caching it (associated with its hash) if found.
+func (self *LightChain) GetHeaderByNumber(number uint64) *types.Header {
+	return self.hc.GetHeaderByNumber(number)
+}
--- a/light/lightchain_test.go
+++ b/light/lightchain_test.go
@ -0,0 +1,399 @@
+// Copyright 2014 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
+
+import (
+	"fmt"
+	"math/big"
+	"runtime"
+	"testing"
+
+	"github.com/ethereum/ethash"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/pow"
+	"github.com/hashicorp/golang-lru"
+	"golang.org/x/net/context"
+)
+
+// So we can deterministically seed different blockchains
+var (
+	canonicalSeed = 1
+	forkSeed      = 2
+)
+
+// makeHeaderChain creates a deterministic chain of headers rooted at parent.
+func makeHeaderChain(parent *types.Header, n int, db ethdb.Database, seed int) []*types.Header {
+	blocks, _ := core.GenerateChain(types.NewBlockWithHeader(parent), db, n, func(i int, b *core.BlockGen) {
+		b.SetCoinbase(common.Address{0: byte(seed), 19: byte(i)})
+	})
+	headers := make([]*types.Header, len(blocks))
+	for i, block := range blocks {
+		headers[i] = block.Header()
+	}
+	return headers
+}
+
+// newCanonical creates a chain database, and injects a deterministic canonical
+// chain. Depending on the full flag, if creates either a full block chain or a
+// header only chain.
+func newCanonical(n int) (ethdb.Database, *LightChain, error) {
+	// Create te new chain database
+	db, _ := ethdb.NewMemDatabase()
+	evmux := &event.TypeMux{}
+
+	// Initialize a fresh chain with only a genesis block
+	genesis, _ := core.WriteTestNetGenesisBlock(db)
+
+	blockchain, _ := NewLightChain(&dummyOdr{db: db}, core.FakePow{}, evmux)
+	// Create and inject the requested chain
+	if n == 0 {
+		return db, blockchain, nil
+	}
+	// Header-only chain requested
+	headers := makeHeaderChain(genesis.Header(), n, db, canonicalSeed)
+	_, err := blockchain.InsertHeaderChain(headers, 1)
+	return db, blockchain, err
+}
+
+func init() {
+	runtime.GOMAXPROCS(runtime.NumCPU())
+}
+
+func thePow() pow.PoW {
+	pow, _ := ethash.NewForTesting()
+	return pow
+}
+
+func theLightChain(db ethdb.Database, t *testing.T) *LightChain {
+	var eventMux event.TypeMux
+	core.WriteTestNetGenesisBlock(db)
+	LightChain, err := NewLightChain(&dummyOdr{db: db}, thePow(), &eventMux)
+	if err != nil {
+		t.Error("failed creating LightChain:", err)
+		t.FailNow()
+		return nil
+	}
+
+	return LightChain
+}
+
+// Test fork of length N starting from block i
+func testFork(t *testing.T, LightChain *LightChain, i, n int, comparator func(td1, td2 *big.Int)) {
+	// Copy old chain up to #i into a new db
+	db, LightChain2, err := newCanonical(i)
+	if err != nil {
+		t.Fatal("could not make new canonical in testFork", err)
+	}
+	// Assert the chains have the same header/block at #i
+	var hash1, hash2 common.Hash
+	hash1 = LightChain.GetHeaderByNumber(uint64(i)).Hash()
+	hash2 = LightChain2.GetHeaderByNumber(uint64(i)).Hash()
+	if hash1 != hash2 {
+		t.Errorf("chain content mismatch at %d: have hash %v, want hash %v", i, hash2, hash1)
+	}
+	// Extend the newly created chain
+	var (
+		headerChainB []*types.Header
+	)
+	headerChainB = makeHeaderChain(LightChain2.CurrentHeader(), n, db, forkSeed)
+	if _, err := LightChain2.InsertHeaderChain(headerChainB, 1); err != nil {
+		t.Fatalf("failed to insert forking chain: %v", err)
+	}
+	// Sanity check that the forked chain can be imported into the original
+	var tdPre, tdPost *big.Int
+
+	tdPre = LightChain.GetTd(LightChain.CurrentHeader().Hash())
+	if err := testHeaderChainImport(headerChainB, LightChain); err != nil {
+		t.Fatalf("failed to import forked header chain: %v", err)
+	}
+	tdPost = LightChain.GetTd(headerChainB[len(headerChainB)-1].Hash())
+	// Compare the total difficulties of the chains
+	comparator(tdPre, tdPost)
+}
+
+func printChain(bc *LightChain) {
+	for i := bc.CurrentHeader().GetNumberU64(); i > 0; i-- {
+		b := bc.GetHeaderByNumber(uint64(i))
+		fmt.Printf("\t%x %v\n", b.Hash(), b.Difficulty)
+	}
+}
+
+// testHeaderChainImport tries to process a chain of header, writing them into
+// the database if successful.
+func testHeaderChainImport(chain []*types.Header, LightChain *LightChain) error {
+	for _, header := range chain {
+		// Try and validate the header
+		if err := LightChain.Validator().ValidateHeader(header, LightChain.GetHeader(header.ParentHash), false); err != nil {
+			return err
+		}
+		// Manually insert the header into the database, but don't reorganize (allows subsequent testing)
+		LightChain.mu.Lock()
+		core.WriteTd(LightChain.chainDb, header.Hash(), new(big.Int).Add(header.Difficulty, LightChain.GetTd(header.ParentHash)))
+		core.WriteHeader(LightChain.chainDb, header)
+		LightChain.mu.Unlock()
+	}
+	return nil
+}
+
+// Tests that given a starting canonical chain of a given size, it can be extended
+// with various length chains.
+func TestExtendCanonicalHeaders(t *testing.T) {
+	length := 5
+
+	// Make first chain starting from genesis
+	_, processor, err := newCanonical(length)
+	if err != nil {
+		t.Fatalf("failed to make new canonical chain: %v", err)
+	}
+	// Define the difficulty comparator
+	better := func(td1, td2 *big.Int) {
+		if td2.Cmp(td1) <= 0 {
+			t.Errorf("total difficulty mismatch: have %v, expected more than %v", td2, td1)
+		}
+	}
+	// Start fork from current height
+	testFork(t, processor, length, 1, better)
+	testFork(t, processor, length, 2, better)
+	testFork(t, processor, length, 5, better)
+	testFork(t, processor, length, 10, better)
+}
+
+// Tests that given a starting canonical chain of a given size, creating shorter
+// forks do not take canonical ownership.
+func TestShorterForkHeaders(t *testing.T) {
+	length := 10
+
+	// Make first chain starting from genesis
+	_, processor, err := newCanonical(length)
+	if err != nil {
+		t.Fatalf("failed to make new canonical chain: %v", err)
+	}
+	// Define the difficulty comparator
+	worse := func(td1, td2 *big.Int) {
+		if td2.Cmp(td1) >= 0 {
+			t.Errorf("total difficulty mismatch: have %v, expected less than %v", td2, td1)
+		}
+	}
+	// Sum of numbers must be less than `length` for this to be a shorter fork
+	testFork(t, processor, 0, 3, worse)
+	testFork(t, processor, 0, 7, worse)
+	testFork(t, processor, 1, 1, worse)
+	testFork(t, processor, 1, 7, worse)
+	testFork(t, processor, 5, 3, worse)
+	testFork(t, processor, 5, 4, worse)
+}
+
+// Tests that given a starting canonical chain of a given size, creating longer
+// forks do take canonical ownership.
+func TestLongerForkHeaders(t *testing.T) {
+	length := 10
+
+	// Make first chain starting from genesis
+	_, processor, err := newCanonical(length)
+	if err != nil {
+		t.Fatalf("failed to make new canonical chain: %v", err)
+	}
+	// Define the difficulty comparator
+	better := func(td1, td2 *big.Int) {
+		if td2.Cmp(td1) <= 0 {
+			t.Errorf("total difficulty mismatch: have %v, expected more than %v", td2, td1)
+		}
+	}
+	// Sum of numbers must be greater than `length` for this to be a longer fork
+	testFork(t, processor, 0, 11, better)
+	testFork(t, processor, 0, 15, better)
+	testFork(t, processor, 1, 10, better)
+	testFork(t, processor, 1, 12, better)
+	testFork(t, processor, 5, 6, better)
+	testFork(t, processor, 5, 8, better)
+}
+
+// Tests that given a starting canonical chain of a given size, creating equal
+// forks do take canonical ownership.
+func TestEqualForkHeaders(t *testing.T) {
+	length := 10
+
+	// Make first chain starting from genesis
+	_, processor, err := newCanonical(length)
+	if err != nil {
+		t.Fatalf("failed to make new canonical chain: %v", err)
+	}
+	// Define the difficulty comparator
+	equal := func(td1, td2 *big.Int) {
+		if td2.Cmp(td1) != 0 {
+			t.Errorf("total difficulty mismatch: have %v, want %v", td2, td1)
+		}
+	}
+	// Sum of numbers must be equal to `length` for this to be an equal fork
+	testFork(t, processor, 0, 10, equal)
+	testFork(t, processor, 1, 9, equal)
+	testFork(t, processor, 2, 8, equal)
+	testFork(t, processor, 5, 5, equal)
+	testFork(t, processor, 6, 4, equal)
+	testFork(t, processor, 9, 1, equal)
+}
+
+// Tests that chains missing links do not get accepted by the processor.
+func TestBrokenHeaderChain(t *testing.T) {
+	// Make chain starting from genesis
+	db, LightChain, err := newCanonical(10)
+	if err != nil {
+		t.Fatalf("failed to make new canonical chain: %v", err)
+	}
+	// Create a forked chain, and try to insert with a missing link
+	chain := makeHeaderChain(LightChain.CurrentHeader(), 5, db, forkSeed)[1:]
+	if err := testHeaderChainImport(chain, LightChain); err == nil {
+		t.Errorf("broken header chain not reported")
+	}
+}
+
+type bproc struct{}
+
+func (bproc) ValidateHeader(*types.Header, *types.Header, bool) error { return nil }
+
+func makeHeaderChainWithDiff(genesis *types.Block, d []int, seed byte) []*types.Header {
+	var chain []*types.Header
+	for i, difficulty := range d {
+		header := &types.Header{
+			Coinbase:    common.Address{seed},
+			Number:      big.NewInt(int64(i + 1)),
+			Difficulty:  big.NewInt(int64(difficulty)),
+			UncleHash:   types.EmptyUncleHash,
+			TxHash:      types.EmptyRootHash,
+			ReceiptHash: types.EmptyRootHash,
+		}
+		if i == 0 {
+			header.ParentHash = genesis.Hash()
+		} else {
+			header.ParentHash = chain[i-1].Hash()
+		}
+		chain = append(chain, types.CopyHeader(header))
+	}
+	return chain
+}
+
+type dummyOdr struct {
+	OdrBackend
+	db ethdb.Database
+}
+
+func (odr *dummyOdr) Database() ethdb.Database {
+	return odr.db
+}
+
+func (odr *dummyOdr) Retrieve(ctx context.Context, req OdrRequest) error {
+	return nil
+}
+
+func chm(genesis *types.Block, db ethdb.Database) *LightChain {
+	odr := &dummyOdr{db: db}
+	var eventMux event.TypeMux
+	bc := &LightChain{odr: odr, chainDb: db, genesisBlock: genesis, eventMux: &eventMux, pow: core.FakePow{}}
+	bc.hc, _ = core.NewHeaderChain(db, bc.Validator, bc.getProcInterrupt)
+	bc.bodyCache, _ = lru.New(100)
+	bc.bodyRLPCache, _ = lru.New(100)
+	bc.blockCache, _ = lru.New(100)
+	bc.SetValidator(bproc{})
+	bc.ResetWithGenesisBlock(genesis)
+
+	return bc
+}
+
+// Tests that reorganizing a long difficult chain after a short easy one
+// overwrites the canonical numbers and links in the database.
+func TestReorgLongHeaders(t *testing.T) {
+	testReorg(t, []int{1, 2, 4}, []int{1, 2, 3, 4}, 10)
+}
+
+// Tests that reorganizing a short difficult chain after a long easy one
+// overwrites the canonical numbers and links in the database.
+func TestReorgShortHeaders(t *testing.T) {
+	testReorg(t, []int{1, 2, 3, 4}, []int{1, 10}, 11)
+}
+
+func testReorg(t *testing.T, first, second []int, td int64) {
+	// Create a pristine block chain
+	db, _ := ethdb.NewMemDatabase()
+	genesis, _ := core.WriteTestNetGenesisBlock(db)
+	bc := chm(genesis, db)
+
+	// Insert an easy and a difficult chain afterwards
+	bc.InsertHeaderChain(makeHeaderChainWithDiff(genesis, first, 11), 1)
+	bc.InsertHeaderChain(makeHeaderChainWithDiff(genesis, second, 22), 1)
+	// Check that the chain is valid number and link wise
+	prev := bc.CurrentHeader()
+	for header := bc.GetHeaderByNumber(bc.CurrentHeader().Number.Uint64() - 1); header.Number.Uint64() != 0; prev, header = header, bc.GetHeaderByNumber(header.Number.Uint64()-1) {
+		if prev.ParentHash != header.Hash() {
+			t.Errorf("parent header hash mismatch: have %x, want %x", prev.ParentHash, header.Hash())
+		}
+	}
+	// Make sure the chain total difficulty is the correct one
+	want := new(big.Int).Add(genesis.Difficulty(), big.NewInt(td))
+	if have := bc.GetTd(bc.CurrentHeader().Hash()); have.Cmp(want) != 0 {
+		t.Errorf("total difficulty mismatch: have %v, want %v", have, want)
+	}
+}
+
+// Tests that the insertion functions detect banned hashes.
+func TestBadHeaderHashes(t *testing.T) {
+	// Create a pristine block chain
+	db, _ := ethdb.NewMemDatabase()
+	genesis, _ := core.WriteTestNetGenesisBlock(db)
+	bc := chm(genesis, db)
+
+	// Create a chain, ban a hash and try to import
+	var err error
+	headers := makeHeaderChainWithDiff(genesis, []int{1, 2, 4}, 10)
+	core.BadHashes[headers[2].Hash()] = true
+	_, err = bc.InsertHeaderChain(headers, 1)
+	if !core.IsBadHashError(err) {
+		t.Errorf("error mismatch: want: BadHashError, have: %v", err)
+	}
+}
+
+// Tests that bad hashes are detected on boot, and the chan rolled back to a
+// good state prior to the bad hash.
+func TestReorgBadHeaderHashes(t *testing.T) {
+	// Create a pristine block chain
+	db, _ := ethdb.NewMemDatabase()
+	genesis, _ := core.WriteTestNetGenesisBlock(db)
+	bc := chm(genesis, db)
+
+	// Create a chain, import and ban aferwards
+	headers := makeHeaderChainWithDiff(genesis, []int{1, 2, 3, 4}, 10)
+
+	if _, err := bc.InsertHeaderChain(headers, 1); err != nil {
+		t.Fatalf("failed to import headers: %v", err)
+	}
+	if bc.CurrentHeader().Hash() != headers[3].Hash() {
+		t.Errorf("last header hash mismatch: have: %x, want %x", bc.CurrentHeader().Hash(), headers[3].Hash())
+	}
+	core.BadHashes[headers[3].Hash()] = true
+	defer func() { delete(core.BadHashes, headers[3].Hash()) }()
+	// Create a new chain manager and check it rolled back the state
+	ncm, err := NewLightChain(&dummyOdr{db: db}, core.FakePow{}, new(event.TypeMux))
+	if err != nil {
+		t.Fatalf("failed to create new chain manager: %v", err)
+	}
+	if ncm.CurrentHeader().Hash() != headers[2].Hash() {
+		t.Errorf("last header hash mismatch: have: %x, want %x", ncm.CurrentHeader().Hash(), headers[2].Hash())
+	}
+}
--- a/light/odr.go
+++ b/light/odr.go
@ -20,13 +20,19 @@ package light

 import (
 	"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/rlp"
 	"golang.org/x/net/context"
 )

-// OdrBackend is an interface to a backend service that handles odr retrievals
+// NoOdr is the default context passed to an ODR capable function when the ODR
+// service is not required.
+var NoOdr = context.Background()
+
+// OdrBackend is an interface to a backend service that handles ODR retrievals
 type OdrBackend interface {
 	Database() ethdb.Database
 	Retrieve(ctx context.Context, req OdrRequest) error
@ -37,17 +43,44 @@ type OdrRequest interface {
 	StoreResult(db ethdb.Database)
 }

+// TrieID identifies a state or account storage trie
+type TrieID struct {
+	blockHash, root common.Hash
+	accKey          []byte
+}
+
+// StateTrieID returns a TrieID for a state trie belonging to a certain block
+// header.
+func StateTrieID(header *types.Header) *TrieID {
+	return &TrieID{
+		blockHash: header.Hash(),
+		accKey:    nil,
+		root:      header.Root,
+	}
+}
+
+// StorageTrieID returns a TrieID for a contract storage trie at a given account
+// of a given state trie. It also requires the root hash of the trie for
+// checking Merkle proofs.
+func StorageTrieID(state *TrieID, addr common.Address, root common.Hash) *TrieID {
+	return &TrieID{
+		blockHash: state.blockHash,
+		accKey:    crypto.Keccak256(addr[:]),
+		root:      root,
+	}
+}
+
 // TrieRequest is the ODR request type for state/storage trie entries
 type TrieRequest struct {
 	OdrRequest
-	root  common.Hash
-	key   []byte
-	proof []rlp.RawValue
+	Id    *TrieID
+	Key   []byte
+	Proof []rlp.RawValue
 }

 // StoreResult stores the retrieved data in local database
 func (req *TrieRequest) StoreResult(db ethdb.Database) {
-	storeProof(db, req.proof)
+	storeProof(db, req.Proof)
 }

 // storeProof stores the new trie nodes obtained from a merkle proof in the database
@ -61,38 +94,39 @@ func storeProof(db ethdb.Database, proof []rlp.RawValue) {
 	}
 }

-// NodeDataRequest is the ODR request type for node data (used for retrieving contract code)
-type NodeDataRequest struct {
+// CodeRequest is the ODR request type for retrieving contract code
+type CodeRequest struct {
 	OdrRequest
-	hash common.Hash
-	data []byte
-}
-
-// GetData returns the retrieved node data after a successful request
-func (req *NodeDataRequest) GetData() []byte {
-	return req.data
+	Id    *TrieID
+	Hash common.Hash
+	Data []byte
 }

 // StoreResult stores the retrieved data in local database
-func (req *NodeDataRequest) StoreResult(db ethdb.Database) {
-	db.Put(req.hash[:], req.GetData())
+func (req *CodeRequest) StoreResult(db ethdb.Database) {
+	db.Put(req.Hash[:], req.Data)
 }

-var sha3_nil = crypto.Keccak256Hash(nil)
-
-// retrieveNodeData tries to retrieve node data with the given hash from the network
-func retrieveNodeData(ctx context.Context, odr OdrBackend, hash common.Hash) ([]byte, error) {
-	if hash == sha3_nil {
-		return nil, nil
-	}
-	res, _ := odr.Database().Get(hash[:])
-	if res != nil {
-		return res, nil
-	}
-	r := &NodeDataRequest{hash: hash}
-	if err := odr.Retrieve(ctx, r); err != nil {
-		return nil, err
-	} else {
-		return r.GetData(), nil
-	}
+// BlockRequest is the ODR request type for retrieving block bodies
+type BlockRequest struct {
+	OdrRequest
+	Hash common.Hash
+	Rlp  []byte
+}
+
+// StoreResult stores the retrieved data in local database
+func (req *BlockRequest) StoreResult(db ethdb.Database) {
+	core.WriteBodyRLP(db, req.Hash, req.Rlp)
+}
+
+// ReceiptsRequest is the ODR request type for retrieving block bodies
+type ReceiptsRequest struct {
+	OdrRequest
+	Hash     common.Hash
+	Receipts types.Receipts
+}
+
+// StoreResult stores the retrieved data in local database
+func (req *ReceiptsRequest) StoreResult(db ethdb.Database) {
+	core.WriteBlockReceipts(db, req.Hash, req.Receipts)
 }
--- a/light/odr_test.go
+++ b/light/odr_test.go
@ -0,0 +1,323 @@
+package light
+
+import (
+	"bytes"
+	"errors"
+	"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/crypto"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/trie"
+	"golang.org/x/net/context"
+)
+
+var (
+	testBankKey, _  = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+	testBankAddress = crypto.PubkeyToAddress(testBankKey.PublicKey)
+	testBankFunds   = big.NewInt(100000000)
+
+	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
+)
+
+type testOdr struct {
+	OdrBackend
+	sdb, ldb ethdb.Database
+	disable  bool
+}
+
+func (odr *testOdr) Database() ethdb.Database {
+	return odr.ldb
+}
+
+var ErrOdrDisabled = errors.New("ODR disabled")
+
+func (odr *testOdr) Retrieve(ctx context.Context, req OdrRequest) error {
+	if odr.disable {
+		return ErrOdrDisabled
+	}
+	switch req := req.(type) {
+	case *BlockRequest:
+		req.Rlp = core.GetBodyRLP(odr.sdb, req.Hash)
+	case *ReceiptsRequest:
+		req.Receipts = core.GetBlockReceipts(odr.sdb, req.Hash)
+	case *TrieRequest:
+		t, _ := trie.New(req.Id.root, odr.sdb)
+		req.Proof = t.Prove(req.Key)
+		trie.ClearGlobalCache()
+	case *CodeRequest:
+		req.Data, _ = odr.sdb.Get(req.Hash[:])
+	}
+	req.StoreResult(odr.ldb)
+	return nil
+}
+
+type odrTestFn func(ctx context.Context, db ethdb.Database, bc *core.BlockChain, lc *LightChain, bhash common.Hash) []byte
+
+func TestOdrGetBlockLes1(t *testing.T) { testChainOdr(t, 1, 1, odrGetBlock) }
+
+func odrGetBlock(ctx context.Context, db ethdb.Database, bc *core.BlockChain, lc *LightChain, bhash common.Hash) []byte {
+	var block *types.Block
+	if bc != nil {
+		block = bc.GetBlock(bhash)
+	} else {
+		block, _ = lc.GetBlock(ctx, bhash)
+	}
+	if block == nil {
+		return nil
+	}
+	rlp, _ := rlp.EncodeToBytes(block)
+	return rlp
+}
+
+func TestOdrGetReceiptsLes1(t *testing.T) { testChainOdr(t, 1, 1, odrGetReceipts) }
+
+func odrGetReceipts(ctx context.Context, db ethdb.Database, bc *core.BlockChain, lc *LightChain, bhash common.Hash) []byte {
+	var receipts types.Receipts
+	if bc != nil {
+		receipts = core.GetBlockReceipts(db, bhash)
+	} else {
+		receipts, _ = GetBlockReceipts(ctx, lc.Odr(), bhash)
+	}
+	if receipts == nil {
+		return nil
+	}
+	rlp, _ := rlp.EncodeToBytes(receipts)
+	return rlp
+}
+
+func TestOdrAccountsLes1(t *testing.T) { testChainOdr(t, 1, 1, odrAccounts) }
+
+func odrAccounts(ctx context.Context, db ethdb.Database, bc *core.BlockChain, lc *LightChain, bhash common.Hash) []byte {
+	dummyAddr := common.HexToAddress("1234567812345678123456781234567812345678")
+	acc := []common.Address{testBankAddress, acc1Addr, acc2Addr, dummyAddr}
+
+	trie.ClearGlobalCache()
+
+	var res []byte
+	for _, addr := range acc {
+		if bc != nil {
+			header := bc.GetHeader(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.GetHeader(bhash)
+			st := NewLightState(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) { testChainOdr(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 m.from.Nonce() }
+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          *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 m.from.Nonce() }
+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, bc *core.BlockChain, lc *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.GetHeader(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, bc, msg, header)
+				gp := new(core.GasPool).AddGas(common.MaxBig)
+				ret, _, _ := core.ApplyMessage(vmenv, msg, gp)
+				res = append(res, ret...)
+			}
+		} else {
+			header := lc.GetHeader(bhash)
+			state := NewLightState(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 := NewEnv(ctx, state, lc, msg, header)
+				gp := new(core.GasPool).AddGas(common.MaxBig)
+				ret, _, _ := core.ApplyMessage(vmenv, msg, gp)
+				if vmenv.Error() == nil {
+					res = append(res, ret...)
+				}
+			}
+		}
+	}
+	return res
+}
+
+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(100000), 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 testChainOdr(t *testing.T, protocol int, expFail uint64, fn odrTestFn) {
+	var (
+		evmux   = new(event.TypeMux)
+		pow     = new(core.FakePow)
+		sdb, _  = ethdb.NewMemDatabase()
+		ldb, _  = ethdb.NewMemDatabase()
+		genesis = core.WriteGenesisBlockForTesting(sdb, core.GenesisAccount{testBankAddress, testBankFunds})
+	)
+	core.WriteGenesisBlockForTesting(ldb, core.GenesisAccount{testBankAddress, testBankFunds})
+	// Assemble the test environment
+	blockchain, _ := core.NewBlockChain(sdb, pow, evmux)
+	gchain, _ := core.GenerateChain(genesis, sdb, 4, testChainGen)
+	if _, err := blockchain.InsertChain(gchain); err != nil {
+		panic(err)
+	}
+
+	odr := &testOdr{sdb: sdb, ldb: ldb}
+	lightchain, _ := NewLightChain(odr, pow, evmux)
+	lightchain.SetValidator(bproc{})
+	headers := make([]*types.Header, len(gchain))
+	for i, block := range gchain {
+		headers[i] = block.Header()
+	}
+	if _, err := lightchain.InsertHeaderChain(headers, 1); err != nil {
+		panic(err)
+	}
+
+	test := func(expFail uint64) {
+		for i := uint64(0); i <= blockchain.CurrentHeader().GetNumberU64(); i++ {
+			bhash := core.GetCanonicalHash(sdb, i)
+			b1 := fn(NoOdr, sdb, blockchain, nil, bhash)
+			ctx, _ := context.WithTimeout(context.Background(), 200*time.Millisecond)
+			b2 := fn(ctx, ldb, nil, 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")
+			}
+		}
+	}
+
+	odr.disable = true
+	// expect retrievals to fail (except genesis block) without a les peer
+	test(expFail)
+	odr.disable = false
+	// expect all retrievals to pass
+	test(5)
+	odr.disable = true
+	// still expect all retrievals to pass, now data should be cached locally
+	test(5)
+}
--- a/light/odr_util.go
+++ b/light/odr_util.go
@ -0,0 +1,112 @@
+// 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
+
+import (
+	"bytes"
+	"errors"
+
+	"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/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/rlp"
+	"golang.org/x/net/context"
+)
+
+var sha3_nil = crypto.Keccak256Hash(nil)
+
+var ErrNoHeader = errors.New("Block header not found")
+
+// retrieveContractCode tries to retrieve the contract code of the given account
+// with the given hash from the network (id points to the storage trie belonging
+// to the same account)
+func retrieveContractCode(ctx context.Context, odr OdrBackend, id *TrieID, hash common.Hash) ([]byte, error) {
+	if hash == sha3_nil {
+		return nil, nil
+	}
+	res, _ := odr.Database().Get(hash[:])
+	if res != nil {
+		return res, nil
+	}
+	r := &CodeRequest{Id: id, Hash: hash}
+	if err := odr.Retrieve(ctx, r); err != nil {
+		return nil, err
+	} else {
+		return r.Data, nil
+	}
+}
+
+// GetBodyRLP retrieves the block body (transactions and uncles) in RLP encoding.
+func GetBodyRLP(ctx context.Context, odr OdrBackend, hash common.Hash) (rlp.RawValue, error) {
+	if data := core.GetBodyRLP(odr.Database(), hash); data != nil {
+		return data, nil
+	}
+	r := &BlockRequest{Hash: hash}
+	if err := odr.Retrieve(ctx, r); err != nil {
+		return nil, err
+	} else {
+		return r.Rlp, nil
+	}
+}
+
+// GetBody retrieves the block body (transactons, uncles) corresponding to the
+// hash.
+func GetBody(ctx context.Context, odr OdrBackend, hash common.Hash) (*types.Body, error) {
+	data, err := GetBodyRLP(ctx, odr, hash)
+	if err != nil {
+		return nil, err
+	}
+	body := new(types.Body)
+	if err := rlp.Decode(bytes.NewReader(data), body); err != nil {
+		glog.V(logger.Error).Infof("invalid block body RLP for hash %x: %v", hash, err)
+		return nil, err
+	}
+	return body, nil
+}
+
+// GetBlock retrieves an entire block corresponding to the hash, assembling it
+// back from the stored header and body.
+func GetBlock(ctx context.Context, odr OdrBackend, hash common.Hash) (*types.Block, error) {
+	// Retrieve the block header and body contents
+	header := core.GetHeader(odr.Database(), hash)
+	if header == nil {
+		return nil, ErrNoHeader
+	}
+	body, err := GetBody(ctx, odr, hash)
+	if err != nil {
+		return nil, err
+	}
+	// Reassemble the block and return
+	return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles), nil
+}
+
+// GetBlockReceipts retrieves the receipts generated by the transactions included
+// in a block given by its hash.
+func GetBlockReceipts(ctx context.Context, odr OdrBackend, hash common.Hash) (types.Receipts, error) {
+	receipts := core.GetBlockReceipts(odr.Database(), hash)
+	if receipts != nil {
+		return receipts, nil
+	}
+	r := &ReceiptsRequest{Hash: hash}
+	if err := odr.Retrieve(ctx, r); err != nil {
+		return nil, err
+	} else {
+		return r.Receipts, nil
+	}
+}
--- a/light/state.go
+++ b/light/state.go
@ -33,10 +33,11 @@ var StartingNonce uint64
 // state, retrieving unknown parts on-demand from the ODR backend. Changes are
 // never stored in the local database, only in the memory objects.
 type LightState struct {
-	odr  OdrBackend
-	trie *LightTrie
-
+	odr          OdrBackend
+	trie         *LightTrie
+	id           *TrieID
 	stateObjects map[string]*StateObject
+	refund       *big.Int
 }

 // NewLightState creates a new LightState with the specified root.
@ -44,15 +45,25 @@ type LightState struct {
 // root is non-existent. In that case, ODR retrieval will always be unsuccessful
 // and every operation will return with an error or wait for the context to be
 // cancelled.
-func NewLightState(root common.Hash, odr OdrBackend) *LightState {
-	tr := NewLightTrie(root, odr, true)
+func NewLightState(id *TrieID, odr OdrBackend) *LightState {
+	var tr *LightTrie
+	if id != nil {
+		tr = NewLightTrie(id, odr, true)
+	}
 	return &LightState{
 		odr:          odr,
 		trie:         tr,
+		id:           id,
 		stateObjects: make(map[string]*StateObject),
+		refund:       new(big.Int),
 	}
 }

+// AddRefund adds an amount to the refund value collected during a vm execution
+func (self *LightState) AddRefund(gas *big.Int) {
+	self.refund.Add(self.refund, gas)
+}
+
 // HasAccount returns true if an account exists at the given address
 func (self *LightState) HasAccount(ctx context.Context, addr common.Address) (bool, error) {
 	so, err := self.GetStateObject(ctx, addr)
@ -194,7 +205,7 @@ func (self *LightState) GetStateObject(ctx context.Context, addr common.Address)
 		return nil, nil
 	}

-	stateObject, err = DecodeObject(ctx, addr, self.odr, []byte(data))
+	stateObject, err = DecodeObject(ctx, self.id, addr, self.odr, []byte(data))
 	if err != nil {
 		return nil, err
 	}
@ -258,12 +269,14 @@ func (self *LightState) CreateStateObject(ctx context.Context, addr common.Addre
 // Copy creates a copy of the state
 func (self *LightState) Copy() *LightState {
 	// ignore error - we assume state-to-be-copied always exists
-	state := NewLightState(common.Hash{}, self.odr)
+	state := NewLightState(nil, self.odr)
 	state.trie = self.trie
+	state.id = self.id
 	for k, stateObject := range self.stateObjects {
 		state.stateObjects[k] = stateObject.Copy()
 	}

+	state.refund.Set(self.refund)
 	return state
 }

@ -272,4 +285,10 @@ func (self *LightState) Copy() *LightState {
 func (self *LightState) Set(state *LightState) {
 	self.trie = state.trie
 	self.stateObjects = state.stateObjects
+	self.refund = state.refund
+}
+
+// GetRefund returns the refund value collected during a vm execution
+func (self *LightState) GetRefund() *big.Int {
+	return self.refund
 }
--- a/light/state_object.go
+++ b/light/state_object.go
@ -102,7 +102,7 @@ func NewStateObject(address common.Address, odr OdrBackend) *StateObject {
 		codeHash: emptyCodeHash,
 		storage:  make(Storage),
 	}
-	object.trie = NewLightTrie(common.Hash{}, odr, true)
+	object.trie = NewLightTrie(nil, odr, true)
 	return object
 }

@ -181,6 +181,9 @@ func (c *StateObject) SetBalance(amount *big.Int) {
 	c.dirty = true
 }

+// ReturnGas returns the gas back to the origin. Used by the Virtual machine or Closures
+func (c *StateObject) ReturnGas(gas, price *big.Int) {}
+
 // Copy creates a copy of the state object
 func (self *StateObject) Copy() *StateObject {
 	stateObject := NewStateObject(self.Address(), self.odr)
@ -235,6 +238,23 @@ func (self *StateObject) Nonce() uint64 {
 	return self.nonce
 }

+// EachStorage calls a callback function for every key/value pair found
+// in the local storage cache. Note that unlike core/state.StateObject,
+// light.StateObject only returns cached values and doesn't download the
+// entire storage tree.
+func (self *StateObject) EachStorage(cb func(key, value []byte)) {
+	for h, v := range self.storage {
+		cb([]byte(h), v.Bytes())
+	}
+}
+
+// Never called, but must be present to allow StateObject to be used
+// as a vm.Account interface that also satisfies the vm.ContractRef
+// interface. Interfaces are awesome.
+func (self *StateObject) Value() *big.Int {
+	panic("Value on StateObject should never be called")
+}
+
 // Encoding

 type extStateObject struct {
@ -245,7 +265,7 @@ type extStateObject struct {
 }

 // DecodeObject decodes an RLP-encoded state object.
-func DecodeObject(ctx context.Context, address common.Address, odr OdrBackend, data []byte) (*StateObject, error) {
+func DecodeObject(ctx context.Context, stateID *TrieID, address common.Address, odr OdrBackend, data []byte) (*StateObject, error) {
 	var (
 		obj = &StateObject{address: address, odr: odr, storage: make(Storage)}
 		ext extStateObject
@ -254,9 +274,10 @@ func DecodeObject(ctx context.Context, address common.Address, odr OdrBackend, d
 	if err = rlp.DecodeBytes(data, &ext); err != nil {
 		return nil, err
 	}
-	obj.trie = NewLightTrie(ext.Root, odr, true)
+	trieID := StorageTrieID(stateID, address, ext.Root)
+	obj.trie = NewLightTrie(trieID, odr, true)
 	if !bytes.Equal(ext.CodeHash, emptyCodeHash) {
-		if obj.code, err = retrieveNodeData(ctx, obj.odr, common.BytesToHash(ext.CodeHash)); err != nil {
+		if obj.code, err = retrieveContractCode(ctx, obj.odr, trieID, common.BytesToHash(ext.CodeHash)); err != nil {
 			return nil, fmt.Errorf("can't find code for hash %x: %v", ext.CodeHash, err)
 		}
 	}
--- a/light/state_test.go
+++ b/light/state_test.go
@ -22,34 +22,14 @@ import (
 	"testing"

 	"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/trie"
 	"golang.org/x/net/context"
 )

-type testOdr struct {
-	OdrBackend
-	sdb, ldb ethdb.Database
-}
-
-func (odr *testOdr) Database() ethdb.Database {
-	return odr.ldb
-}
-
-func (odr *testOdr) Retrieve(ctx context.Context, req OdrRequest) error {
-	switch req := req.(type) {
-	case *TrieRequest:
-		t, _ := trie.New(req.root, odr.sdb)
-		req.proof = t.Prove(req.key)
-		trie.ClearGlobalCache()
-	case *NodeDataRequest:
-		req.data, _ = odr.sdb.Get(req.hash[:])
-	}
-	req.StoreResult(odr.ldb)
-	return nil
-}
-
 func makeTestState() (common.Hash, ethdb.Database) {
 	sdb, _ := ethdb.NewMemDatabase()
 	st, _ := state.New(common.Hash{}, sdb)
@ -71,9 +51,11 @@ func makeTestState() (common.Hash, ethdb.Database) {

 func TestLightStateOdr(t *testing.T) {
 	root, sdb := makeTestState()
+	header := &types.Header{Root: root}
+	core.WriteHeader(sdb, header)
 	ldb, _ := ethdb.NewMemDatabase()
 	odr := &testOdr{sdb: sdb, ldb: ldb}
-	ls := NewLightState(root, odr)
+	ls := NewLightState(StateTrieID(header), odr)
 	ctx := context.Background()
 	trie.ClearGlobalCache()

@ -156,9 +138,11 @@ func TestLightStateOdr(t *testing.T) {

 func TestLightStateSetCopy(t *testing.T) {
 	root, sdb := makeTestState()
+	header := &types.Header{Root: root}
+	core.WriteHeader(sdb, header)
 	ldb, _ := ethdb.NewMemDatabase()
 	odr := &testOdr{sdb: sdb, ldb: ldb}
-	ls := NewLightState(root, odr)
+	ls := NewLightState(StateTrieID(header), odr)
 	ctx := context.Background()
 	trie.ClearGlobalCache()

@ -233,9 +217,11 @@ func TestLightStateSetCopy(t *testing.T) {

 func TestLightStateDelete(t *testing.T) {
 	root, sdb := makeTestState()
+	header := &types.Header{Root: root}
+	core.WriteHeader(sdb, header)
 	ldb, _ := ethdb.NewMemDatabase()
 	odr := &testOdr{sdb: sdb, ldb: ldb}
-	ls := NewLightState(root, odr)
+	ls := NewLightState(StateTrieID(header), odr)
 	ctx := context.Background()
 	trie.ClearGlobalCache()

--- a/light/trie.go
+++ b/light/trie.go
@ -17,7 +17,6 @@
 package light

 import (
-	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/trie"
 	"golang.org/x/net/context"
@ -25,28 +24,28 @@ import (

 // LightTrie is an ODR-capable wrapper around trie.SecureTrie
 type LightTrie struct {
-	trie         *trie.SecureTrie
-	originalRoot common.Hash
-	odr          OdrBackend
-	db           ethdb.Database
+	trie *trie.SecureTrie
+	id   *TrieID
+	odr  OdrBackend
+	db   ethdb.Database
 }

 // NewLightTrie creates a new LightTrie instance. It doesn't instantly try to
 // access the db or network and retrieve the root node, it only initializes its
 // encapsulated SecureTrie at the first actual operation.
-func NewLightTrie(root common.Hash, odr OdrBackend, useFakeMap bool) *LightTrie {
+func NewLightTrie(id *TrieID, odr OdrBackend, useFakeMap bool) *LightTrie {
 	return &LightTrie{
 		// SecureTrie is initialized before first request
-		originalRoot: root,
-		odr:          odr,
-		db:           odr.Database(),
+		id:  id,
+		odr: odr,
+		db:  odr.Database(),
 	}
 }

 // retrieveKey retrieves a single key, returns true and stores nodes in local
 // database if successful
 func (t *LightTrie) retrieveKey(ctx context.Context, key []byte) bool {
-	r := &TrieRequest{root: t.originalRoot, key: key}
+	r := &TrieRequest{Id: t.id, Key: key}
 	return t.odr.Retrieve(ctx, r) == nil
 }

@ -79,7 +78,7 @@ func (t *LightTrie) do(ctx context.Context, fallbackKey []byte, fn func() error)
 func (t *LightTrie) Get(ctx context.Context, key []byte) (res []byte, err error) {
 	err = t.do(ctx, key, func() (err error) {
 		if t.trie == nil {
-			t.trie, err = trie.NewSecure(t.originalRoot, t.db)
+			t.trie, err = trie.NewSecure(t.id.root, t.db)
 		}
 		if err == nil {
 			res, err = t.trie.TryGet(key)
@ -98,7 +97,7 @@ func (t *LightTrie) Get(ctx context.Context, key []byte) (res []byte, err error)
 func (t *LightTrie) Update(ctx context.Context, key, value []byte) (err error) {
 	err = t.do(ctx, key, func() (err error) {
 		if t.trie == nil {
-			t.trie, err = trie.NewSecure(t.originalRoot, t.db)
+			t.trie, err = trie.NewSecure(t.id.root, t.db)
 		}
 		if err == nil {
 			err = t.trie.TryUpdate(key, value)
@ -112,7 +111,7 @@ func (t *LightTrie) Update(ctx context.Context, key, value []byte) (err error) {
 func (t *LightTrie) Delete(ctx context.Context, key []byte) (err error) {
 	err = t.do(ctx, key, func() (err error) {
 		if t.trie == nil {
-			t.trie, err = trie.NewSecure(t.originalRoot, t.db)
+			t.trie, err = trie.NewSecure(t.id.root, t.db)
 		}
 		if err == nil {
 			err = t.trie.TryDelete(key)
--- a/light/txpool.go
+++ b/light/txpool.go
@ -0,0 +1,506 @@
+// 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
+
+import (
+	"fmt"
+	"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/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/params"
+	"github.com/ethereum/go-ethereum/rlp"
+	"golang.org/x/net/context"
+)
+
+// txPermanent is the number of mined blocks after a mined transaction is
+// considered permanent and no rollback is expected
+var txPermanent = uint64(500)
+
+// TxPool implements the transaction pool for light clients, which keeps track
+// of the status of locally created transactions, detecting if they are included
+// in a block (mined) or rolled back. There are no queued transactions since we
+// always receive all locally signed transactions in the same order as they are
+// created.
+type TxPool struct {
+	quit     chan bool
+	eventMux *event.TypeMux
+	events   event.Subscription
+	mu       sync.RWMutex
+	chain    *LightChain
+	odr      OdrBackend
+	chainDb  ethdb.Database
+	relay    TxRelayBackend
+	head     common.Hash
+	nonce    map[common.Address]uint64            // "pending" nonce
+	pending  map[common.Hash]*types.Transaction   // pending transactions by tx hash
+	mined    map[common.Hash][]*types.Transaction // mined transactions by block hash
+	clearIdx uint64                               // earliest block nr that can contain mined tx info
+
+	homestead bool
+}
+
+// TxRelayBackend provides an interface to the mechanism that forwards transacions
+// to the ETH network. The implementations of the functions should be non-blocking.
+//
+// Send instructs backend to forward new transactions
+// NewHead notifies backend about a new head after processed by the tx pool,
+//  including  mined and rolled back transactions since the last event
+// Discard notifies backend about transactions that should be discarded either
+//  because they have been replaced by a re-send or because they have been mined
+//  long ago and no rollback is expected
+type TxRelayBackend interface {
+	Send(txs types.Transactions)
+	NewHead(head common.Hash, mined []common.Hash, rollback []common.Hash)
+	Discard(hashes []common.Hash)
+}
+
+// NewTxPool creates a new light transaction pool
+func NewTxPool(eventMux *event.TypeMux, chain *LightChain, relay TxRelayBackend) *TxPool {
+	pool := &TxPool{
+		nonce:    make(map[common.Address]uint64),
+		pending:  make(map[common.Hash]*types.Transaction),
+		mined:    make(map[common.Hash][]*types.Transaction),
+		quit:     make(chan bool),
+		eventMux: eventMux,
+		events:   eventMux.Subscribe(LightChainHeadEvent{}),
+		chain:    chain,
+		relay:    relay,
+		odr:      chain.Odr(),
+		chainDb:  chain.Odr().Database(),
+		head:     chain.CurrentHeader().Hash(),
+		clearIdx: chain.CurrentHeader().GetNumberU64(),
+	}
+	go pool.eventLoop()
+
+	return pool
+}
+
+// currentState returns the light state of the current head header
+func (pool *TxPool) currentState() *LightState {
+	return NewLightState(StateTrieID(pool.chain.CurrentHeader()), pool.odr)
+}
+
+// GetNonce returns the "pending" nonce of a given address. It always queries
+// the nonce belonging to the latest header too in order to detect if another
+// client using the same key sent a transaction.
+func (pool *TxPool) GetNonce(ctx context.Context, addr common.Address) (uint64, error) {
+	nonce, err := pool.currentState().GetNonce(ctx, addr)
+	if err != nil {
+		return 0, err
+	}
+	sn, ok := pool.nonce[addr]
+	if ok && sn > nonce {
+		nonce = sn
+	}
+	if !ok || sn < nonce {
+		pool.nonce[addr] = nonce
+	}
+	return nonce, nil
+}
+
+type txBlockData struct {
+	BlockHash  common.Hash
+	BlockIndex uint64
+	Index      uint64
+}
+
+// storeTxBlockData stores the block position of a mined tx in the local db
+func (pool *TxPool) storeTxBlockData(txh common.Hash, tbd txBlockData) {
+	data, _ := rlp.EncodeToBytes(tbd)
+	pool.chainDb.Put(append(txh[:], byte(1)), data)
+}
+
+// removeTxBlockData removes the stored block position of a rolled back tx
+func (pool *TxPool) removeTxBlockData(txh common.Hash) {
+	pool.chainDb.Delete(append(txh[:], byte(1)))
+}
+
+// txStateChanges stores the recent changes between pending/mined states of
+// transactions. True means mined, false means rolled back, no entry means no change
+type txStateChanges map[common.Hash]bool
+
+// setState sets the status of a tx to either recently mined or recently rolled back
+func (txc txStateChanges) setState(txHash common.Hash, mined bool) {
+	val, ent := txc[txHash]
+	if ent && (val != mined) {
+		delete(txc, txHash)
+	} else {
+		txc[txHash] = mined
+	}
+}
+
+// getLists creates lists of mined and rolled back tx hashes
+func (txc txStateChanges) getLists() (mined []common.Hash, rollback []common.Hash) {
+	for hash, val := range txc {
+		if val {
+			mined = append(mined, hash)
+		} else {
+			rollback = append(rollback, hash)
+		}
+	}
+	return
+}
+
+// checkMinedTxs checks newly added blocks for the currently pending transactions
+// and marks them as mined if necessary. It also stores block position in the db
+// and adds them to the received txStateChanges map.
+func (pool *TxPool) checkMinedTxs(ctx context.Context, hash common.Hash, idx uint64, txc txStateChanges) error {
+	if len(pool.pending) == 0 {
+		return nil
+	}
+
+	receipts, err := GetBlockReceipts(ctx, pool.odr, hash)
+	if err != nil {
+		return err
+	}
+	list := pool.mined[hash]
+	for i, receipt := range receipts {
+		txHash := receipt.TxHash
+		if tx, ok := pool.pending[txHash]; ok {
+			pool.storeTxBlockData(txHash, txBlockData{hash, idx, uint64(i)})
+			delete(pool.pending, txHash)
+			list = append(list, tx)
+			txc.setState(txHash, true)
+		}
+	}
+	if list != nil {
+		pool.mined[hash] = list
+	}
+	return nil
+}
+
+// rollbackTxs marks the transactions contained in recently rolled back blocks
+// as rolled back. It also removes block position info from the db and adds them
+// to the received txStateChanges map.
+func (pool *TxPool) rollbackTxs(hash common.Hash, txc txStateChanges) {
+	if list, ok := pool.mined[hash]; ok {
+		for _, tx := range list {
+			txHash := tx.Hash()
+			pool.removeTxBlockData(txHash)
+			pool.pending[txHash] = tx
+			txc.setState(txHash, false)
+		}
+		delete(pool.mined, hash)
+	}
+}
+
+// setNewHead sets a new head header, processing (and rolling back if necessary)
+// the blocks since the last known head and returns a txStateChanges map containing
+// the recently mined and rolled back transaction hashes. If an error (context
+// timeout) occurs during checking new blocks, it leaves the locally known head
+// at the latest checked block and still returns a valid txStateChanges, making it
+// possible to continue checking the missing blocks at the next chain head event
+func (pool *TxPool) setNewHead(ctx context.Context, newHeader *types.Header) (txStateChanges, error) {
+	txc := make(txStateChanges)
+	oldh := pool.chain.GetHeader(pool.head)
+	newh := newHeader
+	// find common ancestor, create list of rolled back and new block hashes
+	var oldHashes, newHashes []common.Hash
+	for oldh.Hash() != newh.Hash() {
+		if oldh.GetNumberU64() >= newh.GetNumberU64() {
+			oldHashes = append(oldHashes, oldh.Hash())
+			oldh = pool.chain.GetHeader(oldh.ParentHash)
+		}
+		if oldh.GetNumberU64() < newh.GetNumberU64() {
+			newHashes = append(newHashes, newh.Hash())
+			newh = pool.chain.GetHeader(newh.ParentHash)
+		}
+	}
+	if oldh.GetNumberU64() < pool.clearIdx {
+		pool.clearIdx = oldh.GetNumberU64()
+	}
+	// roll back old blocks
+	for _, hash := range oldHashes {
+		pool.rollbackTxs(hash, txc)
+	}
+	pool.head = oldh.Hash()
+	// check mined txs of new blocks (array is in reversed order)
+	for i := len(newHashes) - 1; i >= 0; i-- {
+		hash := newHashes[i]
+		if err := pool.checkMinedTxs(ctx, hash, newHeader.GetNumberU64()-uint64(i), txc); err != nil {
+			return txc, err
+		}
+		pool.head = hash
+	}
+
+	// clear old mined tx entries of old blocks
+	if idx := newHeader.GetNumberU64(); idx > pool.clearIdx+txPermanent {
+		idx2 := idx - txPermanent
+		for i := pool.clearIdx; i < idx2; i++ {
+			hash := core.GetCanonicalHash(pool.chainDb, i)
+			if list, ok := pool.mined[hash]; ok {
+				hashes := make([]common.Hash, len(list))
+				for i, tx := range list {
+					hashes[i] = tx.Hash()
+				}
+				pool.relay.Discard(hashes)
+				delete(pool.mined, hash)
+			}
+		}
+		pool.clearIdx = idx2
+	}
+
+	return txc, nil
+}
+
+// blockCheckTimeout is the time limit for checking new blocks for mined
+// transactions. Checking resumes at the next chain head event if timed out.
+const blockCheckTimeout = time.Second * 3
+
+// eventLoop processes chain head events and also notifies the tx relay backend
+// about the new head hash and tx state changes
+func (pool *TxPool) eventLoop() {
+	for ev := range pool.events.Chan() {
+		switch ev.Data.(type) {
+		case LightChainHeadEvent:
+			pool.mu.Lock()
+			ctx, _ := context.WithTimeout(context.Background(), blockCheckTimeout)
+			head := pool.chain.CurrentHeader()
+			txc, _ := pool.setNewHead(ctx, head)
+			m, r := txc.getLists()
+			pool.relay.NewHead(pool.head, m, r)
+			pool.homestead = params.IsHomestead(head.Number)
+			pool.mu.Unlock()
+		}
+	}
+}
+
+// Stop stops the light transaction pool
+func (pool *TxPool) Stop() {
+	close(pool.quit)
+	pool.events.Unsubscribe()
+	glog.V(logger.Info).Infoln("Transaction pool stopped")
+}
+
+// Stats returns the number of currently pending (locally created) transactions
+func (pool *TxPool) Stats() (pending int) {
+	pool.mu.RLock()
+	defer pool.mu.RUnlock()
+
+	pending = len(pool.pending)
+	return
+}
+
+// validateTx checks whether a transaction is valid according to the consensus rules.
+func (pool *TxPool) validateTx(ctx context.Context, tx *types.Transaction) error {
+	// Validate sender
+	var (
+		from common.Address
+		err  error
+	)
+
+	// Validate the transaction sender and it's sig. Throw
+	// if the from fields is invalid.
+	if from, err = tx.From(); err != nil {
+		return core.ErrInvalidSender
+	}
+
+	// Make sure the account exist. Non existent accounts
+	// haven't got funds and well therefor never pass.
+	currentState := pool.currentState()
+	if h, err := currentState.HasAccount(ctx, from); err == nil {
+		if !h {
+			return core.ErrNonExistentAccount
+		}
+	} else {
+		return err
+	}
+
+	// Last but not least check for nonce errors
+	if n, err := currentState.GetNonce(ctx, from); err == nil {
+		if n > tx.Nonce() {
+			return core.ErrNonce
+		}
+	} else {
+		return err
+	}
+
+	// Check the transaction doesn't exceed the current
+	// block limit gas.
+	header := pool.chain.GetHeader(pool.head)
+	if header.GasLimit.Cmp(tx.Gas()) < 0 {
+		return core.ErrGasLimit
+	}
+
+	// Transactions can't be negative. This may never happen
+	// using RLP decoded transactions but may occur if you create
+	// a transaction using the RPC for example.
+	if tx.Value().Cmp(common.Big0) < 0 {
+		return core.ErrNegativeValue
+	}
+
+	// Transactor should have enough funds to cover the costs
+	// cost == V + GP * GL
+	if b, err := currentState.GetBalance(ctx, from); err == nil {
+		if b.Cmp(tx.Cost()) < 0 {
+			return core.ErrInsufficientFunds
+		}
+	} else {
+		return err
+	}
+
+	// Should supply enough intrinsic gas
+	if tx.Gas().Cmp(core.IntrinsicGas(tx.Data(), core.MessageCreatesContract(tx), pool.homestead)) < 0 {
+		return core.ErrIntrinsicGas
+	}
+
+	return nil
+}
+
+// add validates a new transaction and sets its state pending if processable.
+// It also updates the locally stored nonce if necessary.
+func (self *TxPool) add(ctx context.Context, tx *types.Transaction) error {
+	hash := tx.Hash()
+
+	if self.pending[hash] != nil {
+		return fmt.Errorf("Known transaction (%x)", hash[:4])
+	}
+	err := self.validateTx(ctx, tx)
+	if err != nil {
+		return err
+	}
+
+	if _, ok := self.pending[hash]; !ok {
+		self.pending[hash] = tx
+
+		nonce := tx.Nonce() + 1
+		addr, _ := tx.From()
+		if nonce > self.nonce[addr] {
+			self.nonce[addr] = nonce
+		}
+
+		// Notify the subscribers. This event is posted in a goroutine
+		// because it's possible that somewhere during the post "Remove transaction"
+		// gets called which will then wait for the global tx pool lock and deadlock.
+		go self.eventMux.Post(core.TxPreEvent{tx})
+	}
+
+	if glog.V(logger.Debug) {
+		var toname string
+		if to := tx.To(); to != nil {
+			toname = common.Bytes2Hex(to[:4])
+		} else {
+			toname = "[NEW_CONTRACT]"
+		}
+		// we can ignore the error here because From is
+		// verified in ValidateTransaction.
+		f, _ := tx.From()
+		from := common.Bytes2Hex(f[:4])
+		glog.Infof("(t) %x => %s (%v) %x\n", from, toname, tx.Value, hash)
+	}
+
+	return nil
+}
+
+// Add adds a transaction to the pool if valid and passes it to the tx relay
+// backend
+func (self *TxPool) Add(ctx context.Context, tx *types.Transaction) error {
+	self.mu.Lock()
+	defer self.mu.Unlock()
+
+	data, err := rlp.EncodeToBytes(tx)
+	if err != nil {
+		return err
+	}
+
+	if err := self.add(ctx, tx); err != nil {
+		return err
+	}
+	self.relay.Send(types.Transactions{tx})
+
+	self.chainDb.Put(tx.Hash().Bytes(), data)
+	return nil
+}
+
+// AddTransactions adds all valid transactions to the pool and passes them to
+// the tx relay backend
+func (self *TxPool) AddTransactions(ctx context.Context, txs []*types.Transaction) {
+	self.mu.Lock()
+	defer self.mu.Unlock()
+	var sendTx types.Transactions
+
+	for _, tx := range txs {
+		if err := self.add(ctx, tx); err != nil {
+			glog.V(logger.Debug).Infoln("tx error:", err)
+		} else {
+			sendTx = append(sendTx, tx)
+			h := tx.Hash()
+			glog.V(logger.Debug).Infof("tx %x\n", h[:4])
+		}
+	}
+
+	if len(sendTx) > 0 {
+		self.relay.Send(sendTx)
+	}
+}
+
+// GetTransaction returns a transaction if it is contained in the pool
+// and nil otherwise.
+func (tp *TxPool) GetTransaction(hash common.Hash) *types.Transaction {
+	// check the txs first
+	if tx, ok := tp.pending[hash]; ok {
+		return tx
+	}
+	return nil
+}
+
+// GetTransactions returns all currently processable transactions.
+// The returned slice may be modified by the caller.
+func (self *TxPool) GetTransactions() (txs types.Transactions) {
+	self.mu.Lock()
+	defer self.mu.Unlock()
+
+	txs = make(types.Transactions, len(self.pending))
+	i := 0
+	for _, tx := range self.pending {
+		txs[i] = tx
+		i++
+	}
+	return txs
+}
+
+// RemoveTransactions removes all given transactions from the pool.
+func (self *TxPool) RemoveTransactions(txs types.Transactions) {
+	self.mu.Lock()
+	defer self.mu.Unlock()
+	var hashes []common.Hash
+	for _, tx := range txs {
+		//self.RemoveTx(tx.Hash())
+		hash := tx.Hash()
+		delete(self.pending, hash)
+		self.chainDb.Delete(hash[:])
+		hashes = append(hashes, hash)
+	}
+	self.relay.Discard(hashes)
+}
+
+// RemoveTx removes the transaction with the given hash from the pool.
+func (pool *TxPool) RemoveTx(hash common.Hash) {
+	pool.mu.Lock()
+	defer pool.mu.Unlock()
+	// delete from pending pool
+	delete(pool.pending, hash)
+	pool.chainDb.Delete(hash[:])
+	pool.relay.Discard([]common.Hash{hash})
+}
--- a/light/txpool_test.go
+++ b/light/txpool_test.go
@ -0,0 +1,140 @@
+// Copyright 2014 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
+
+import (
+	"math"
+	"math/big"
+	"testing"
+	"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/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/params"
+	"golang.org/x/net/context"
+)
+
+type testTxRelay struct {
+	send, nhMined, nhRollback, discard int
+}
+
+func (self *testTxRelay) Send(txs types.Transactions) {
+	self.send = len(txs)
+}
+
+func (self *testTxRelay) NewHead(head common.Hash, mined []common.Hash, rollback []common.Hash) {
+	self.nhMined = len(mined)
+	self.nhRollback = len(rollback)
+}
+
+func (self *testTxRelay) Discard(hashes []common.Hash) {
+	self.discard = len(hashes)
+}
+
+const poolTestTxs = 1000
+const poolTestBlocks = 100
+
+// test tx 0..n-1
+var testTx [poolTestTxs]*types.Transaction
+
+// txs sent before block i
+func sentTx(i int) int {
+	return int(math.Pow(float64(i)/float64(poolTestBlocks), 0.9) * poolTestTxs)
+}
+
+// txs included in block i or before that (minedTx(i) <= sentTx(i))
+func minedTx(i int) int {
+	return int(math.Pow(float64(i)/float64(poolTestBlocks), 1.1) * poolTestTxs)
+}
+
+func txPoolTestChainGen(i int, block *core.BlockGen) {
+	s := minedTx(i)
+	e := minedTx(i + 1)
+	for i := s; i < e; i++ {
+		block.AddTx(testTx[i])
+	}
+}
+
+func TestTxPool(t *testing.T) {
+	for i, _ := range testTx {
+		testTx[i], _ = types.NewTransaction(uint64(i), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(testBankKey)
+	}
+
+	var (
+		evmux   = new(event.TypeMux)
+		pow     = new(core.FakePow)
+		sdb, _  = ethdb.NewMemDatabase()
+		ldb, _  = ethdb.NewMemDatabase()
+		genesis = core.WriteGenesisBlockForTesting(sdb, core.GenesisAccount{testBankAddress, testBankFunds})
+	)
+	core.WriteGenesisBlockForTesting(ldb, core.GenesisAccount{testBankAddress, testBankFunds})
+	// Assemble the test environment
+	blockchain, _ := core.NewBlockChain(sdb, pow, evmux)
+	gchain, _ := core.GenerateChain(genesis, sdb, poolTestBlocks, txPoolTestChainGen)
+	if _, err := blockchain.InsertChain(gchain); err != nil {
+		panic(err)
+	}
+
+	odr := &testOdr{sdb: sdb, ldb: ldb}
+	relay := &testTxRelay{}
+	lightchain, _ := NewLightChain(odr, pow, evmux)
+	lightchain.SetValidator(bproc{})
+	txPermanent = 50
+	pool := NewTxPool(evmux, lightchain, relay)
+
+	for ii, block := range gchain {
+		i := ii + 1
+		ctx, _ := context.WithTimeout(context.Background(), 200*time.Millisecond)
+		s := sentTx(i - 1)
+		e := sentTx(i)
+		for i := s; i < e; i++ {
+			relay.send = 0
+			pool.Add(ctx, testTx[i])
+			got := relay.send
+			exp := 1
+			if got != exp {
+				t.Errorf("relay.Send expected len = %d, got %d", exp, got)
+			}
+		}
+
+		relay.nhMined = 0
+		relay.nhRollback = 0
+		relay.discard = 0
+		if _, err := lightchain.InsertHeaderChain([]*types.Header{block.Header()}, 1); err != nil {
+			panic(err)
+		}
+		time.Sleep(time.Millisecond * 10)
+
+		got := relay.nhMined
+		exp := minedTx(i) - minedTx(i-1)
+		if got != exp {
+			t.Errorf("relay.NewHead expected len(mined) = %d, got %d", exp, got)
+		}
+
+		got = relay.discard
+		exp = 0
+		if i > int(txPermanent)+1 {
+			exp = minedTx(i-int(txPermanent)-1) - minedTx(i-int(txPermanent)-2)
+		}
+		if got != exp {
+			t.Errorf("relay.Discard expected len = %d, got %d", exp, got)
+		}
+	}
+}
--- a/light/vm_env.go
+++ b/light/vm_env.go
@ -0,0 +1,241 @@
+// 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
+
+import (
+	"math/big"
+
+	"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"
+	"golang.org/x/net/context"
+)
+
+// VMEnv is the light client version of the vm execution environment.
+// Unlike other structures, VMEnv holds a context that is applied by state
+// retrieval requests through the entire execution. If any state operation
+// returns an error, the execution fails.
+type VMEnv struct {
+	vm.Environment
+	ctx    context.Context
+	state  *VMState
+	header *types.Header
+	msg    core.Message
+	depth  int
+	chain  *LightChain
+	typ    vm.Type
+	// structured logging
+	logs []vm.StructLog
+	err  error
+}
+
+// NewEnv creates a new execution environment based on an ODR capable light state
+func NewEnv(ctx context.Context, state *LightState, chain *LightChain, msg core.Message, header *types.Header) *VMEnv {
+	env := &VMEnv{
+		chain:  chain,
+		header: header,
+		msg:    msg,
+		typ:    vm.StdVmTy,
+	}
+	env.state = &VMState{ctx: ctx, state: state, env: env}
+	return env
+}
+
+func (self *VMEnv) Origin() common.Address   { f, _ := self.msg.From(); return f }
+func (self *VMEnv) BlockNumber() *big.Int    { return self.header.Number }
+func (self *VMEnv) Coinbase() common.Address { return self.header.Coinbase }
+func (self *VMEnv) Time() *big.Int           { return self.header.Time }
+func (self *VMEnv) Difficulty() *big.Int     { return self.header.Difficulty }
+func (self *VMEnv) GasLimit() *big.Int       { return self.header.GasLimit }
+func (self *VMEnv) Value() *big.Int          { return self.msg.Value() }
+func (self *VMEnv) Db() vm.Database          { return self.state }
+func (self *VMEnv) Depth() int               { return self.depth }
+func (self *VMEnv) SetDepth(i int)           { self.depth = i }
+func (self *VMEnv) VmType() vm.Type          { return self.typ }
+func (self *VMEnv) SetVmType(t vm.Type)      { self.typ = t }
+func (self *VMEnv) GetHash(n uint64) common.Hash {
+	for header := self.chain.GetHeader(self.header.ParentHash); header != nil; header = self.chain.GetHeader(header.ParentHash) {
+		if header.GetNumberU64() == n {
+			return header.Hash()
+		}
+	}
+
+	return common.Hash{}
+}
+
+func (self *VMEnv) AddLog(log *vm.Log) {
+	//self.state.AddLog(log)
+}
+func (self *VMEnv) CanTransfer(from common.Address, balance *big.Int) bool {
+	return self.state.GetBalance(from).Cmp(balance) >= 0
+}
+
+func (self *VMEnv) MakeSnapshot() vm.Database {
+	return &VMState{ctx: self.ctx, state: self.state.state.Copy(), env: self}
+}
+
+func (self *VMEnv) SetSnapshot(copy vm.Database) {
+	self.state.state.Set(copy.(*VMState).state)
+}
+
+func (self *VMEnv) Transfer(from, to vm.Account, amount *big.Int) {
+	core.Transfer(from, to, amount)
+}
+
+func (self *VMEnv) Call(me vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	return core.Call(self, me, addr, data, gas, price, value)
+}
+func (self *VMEnv) CallCode(me vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
+	return core.CallCode(self, me, addr, data, gas, price, value)
+}
+
+func (self *VMEnv) Create(me vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) {
+	return core.Create(self, me, data, gas, price, value)
+}
+
+func (self *VMEnv) StructLogs() []vm.StructLog {
+	return self.logs
+}
+
+func (self *VMEnv) AddStructLog(log vm.StructLog) {
+	self.logs = append(self.logs, log)
+}
+
+// Error returns the error (if any) that happened during execution.
+func (self *VMEnv) Error() error {
+	return self.err
+}
+
+// VMState is a wrapper for the light state that holds the actual context and
+// passes it to any state operation that requires it.
+type VMState struct {
+	vm.Database
+	ctx   context.Context
+	state *LightState
+	env   *VMEnv
+}
+
+// errHandler handles and stores any state error that happens during execution.
+func (s *VMState) errHandler(err error) {
+	if err != nil && s.env.err == nil {
+		s.env.err = err
+	}
+}
+
+// GetAccount returns the account object of the given account or nil if the
+// account does not exist
+func (s *VMState) GetAccount(addr common.Address) vm.Account {
+	so, err := s.state.GetStateObject(s.ctx, addr)
+	s.errHandler(err)
+	return so
+}
+
+// CreateAccount creates creates a new account object and takes ownership.
+func (s *VMState) CreateAccount(addr common.Address) vm.Account {
+	so, err := s.state.CreateStateObject(s.ctx, addr)
+	s.errHandler(err)
+	return so
+}
+
+// AddBalance adds the given amount to the balance of the specified account
+func (s *VMState) AddBalance(addr common.Address, amount *big.Int) {
+	err := s.state.AddBalance(s.ctx, addr, amount)
+	s.errHandler(err)
+}
+
+// GetBalance retrieves the balance from the given address or 0 if the account does
+// not exist
+func (s *VMState) GetBalance(addr common.Address) *big.Int {
+	res, err := s.state.GetBalance(s.ctx, addr)
+	s.errHandler(err)
+	return res
+}
+
+// GetNonce returns the nonce at the given address or 0 if the account does
+// not exist
+func (s *VMState) GetNonce(addr common.Address) uint64 {
+	res, err := s.state.GetNonce(s.ctx, addr)
+	s.errHandler(err)
+	return res
+}
+
+// SetNonce sets the nonce of the specified account
+func (s *VMState) SetNonce(addr common.Address, nonce uint64) {
+	err := s.state.SetNonce(s.ctx, addr, nonce)
+	s.errHandler(err)
+}
+
+// GetCode returns the contract code at the given address or nil if the account
+// does not exist
+func (s *VMState) GetCode(addr common.Address) []byte {
+	res, err := s.state.GetCode(s.ctx, addr)
+	s.errHandler(err)
+	return res
+}
+
+// SetCode sets the contract code at the specified account
+func (s *VMState) SetCode(addr common.Address, code []byte) {
+	err := s.state.SetCode(s.ctx, addr, code)
+	s.errHandler(err)
+}
+
+// AddRefund adds an amount to the refund value collected during a vm execution
+func (s *VMState) AddRefund(gas *big.Int) {
+	s.state.AddRefund(gas)
+}
+
+// GetRefund returns the refund value collected during a vm execution
+func (s *VMState) GetRefund() *big.Int {
+	return s.state.GetRefund()
+}
+
+// GetState returns the contract storage value at storage address b from the
+// contract address a or common.Hash{} if the account does not exist
+func (s *VMState) GetState(a common.Address, b common.Hash) common.Hash {
+	res, err := s.state.GetState(s.ctx, a, b)
+	s.errHandler(err)
+	return res
+}
+
+// SetState sets the storage value at storage address key of the account addr
+func (s *VMState) SetState(addr common.Address, key common.Hash, value common.Hash) {
+	err := s.state.SetState(s.ctx, addr, key, value)
+	s.errHandler(err)
+}
+
+// Delete marks an account to be removed and clears its balance
+func (s *VMState) Delete(addr common.Address) bool {
+	res, err := s.state.Delete(s.ctx, addr)
+	s.errHandler(err)
+	return res
+}
+
+// Exist returns true if an account exists at the given address
+func (s *VMState) Exist(addr common.Address) bool {
+	res, err := s.state.HasAccount(s.ctx, addr)
+	s.errHandler(err)
+	return res
+}
+
+// IsDeleted returns true if the given account has been marked for deletion
+// or false if the account does not exist
+func (s *VMState) IsDeleted(addr common.Address) bool {
+	res, err := s.state.IsDeleted(s.ctx, addr)
+	s.errHandler(err)
+	return res
+}