consensus, core, ethstats: use engine specific block beneficiary

consensus/clique/clique.go

@@ -220,6 +220,12 @@ func New(config *params.CliqueConfig, db ethdb.Database) *Clique {
 	}
 }
 
+// Author implements consensus.Engine, returning the Ethereum address recovered
+// from the signature in the header's extra-data section.
+func (c *Clique) Author(header *types.Header) (common.Address, error) {
+	return ecrecover(header)
+}
+
 // VerifyHeader checks whether a header conforms to the consensus rules.
 func (c *Clique) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error {
 	return c.verifyHeader(chain, header, nil)

consensus/consensus.go

@@ -46,6 +46,11 @@ type ChainReader interface {
 
 // Engine is an algorithm agnostic consensus engine.
 type Engine interface {
+	// Author retrieves the Ethereum address of the account that minted the given
+	// block, which may be different from the header's coinbase if a consensus
+	// engine is based on signatures.
+	Author(header *types.Header) (common.Address, error)
+
 	// VerifyHeader checks whether a header conforms to the consensus rules of a
 	// given engine. Verifying the seal may be done optionally here, or explicitly
 	// via the VerifySeal method.

consensus/ethash/consensus.go

@@ -59,6 +59,12 @@ var (
 	errInvalidPoW        = errors.New("invalid proof-of-work")
 )
 
+// Author implements consensus.Engine, returning the header's coinbase as the
+// proof-of-work verified author of the block.
+func (ethash *Ethash) Author(header *types.Header) (common.Address, error) {
+	return header.Coinbase, nil
+}
+
 // VerifyHeader checks whether a header conforms to the consensus rules of the
 // stock Ethereum ethash engine.
 func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error {

core/blockchain.go

@@ -1398,3 +1398,6 @@ func (self *BlockChain) GetHeaderByNumber(number uint64) *types.Header {
 
 // Config retrieves the blockchain's chain configuration.
 func (self *BlockChain) Config() *params.ChainConfig { return self.config }
+
+// Engine retrieves the blockchain's consensus engine.
+func (self *BlockChain) Engine() consensus.Engine { return self.engine }

core/chain_makers.go

@@ -85,7 +85,7 @@ func (b *BlockGen) AddTx(tx *types.Transaction) {
 		b.SetCoinbase(common.Address{})
 	}
 	b.statedb.StartRecord(tx.Hash(), common.Hash{}, len(b.txs))
-	receipt, _, err := ApplyTransaction(b.config, nil, b.gasPool, b.statedb, b.header, tx, b.header.GasUsed, vm.Config{})
+	receipt, _, err := ApplyTransaction(b.config, &BlockChain{engine: ethash.NewFaker()}, b.gasPool, b.statedb, b.header, tx, b.header.GasUsed, vm.Config{})
 	if err != nil {
 		panic(err)
 	}

core/evm.go

@@ -20,25 +20,34 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 )
 
-// BlockFetcher retrieves headers by their hash
-type HeaderFetcher interface {
-	// GetHeader returns the hash corresponding to their hash
+// ChainContext supports retrieving headers and consensus parameters from the
+// current blockchain to be used during transaction processing.
+type ChainContext interface {
+	// Engine retrieves the chain's consensus engine.
+	Engine() consensus.Engine
+
+	// GetHeader returns the hash corresponding to their hash.
 	GetHeader(common.Hash, uint64) *types.Header
 }
 
 // NewEVMContext creates a new context for use in the EVM.
-func NewEVMContext(msg Message, header *types.Header, chain HeaderFetcher) vm.Context {
+func NewEVMContext(msg Message, header *types.Header, chain ChainContext) vm.Context {
+	author, err := chain.Engine().Author(header)
+	if err != nil {
+		// Explicitly ignore, don't crash. Header is invalid.
+	}
 	return vm.Context{
 		CanTransfer: CanTransfer,
 		Transfer:    Transfer,
 		GetHash:     GetHashFn(header, chain),
 
 		Origin:      msg.From(),
-		Coinbase:    header.Coinbase,
+		Coinbase:    author,
 		BlockNumber: new(big.Int).Set(header.Number),
 		Time:        new(big.Int).Set(header.Time),
 		Difficulty:  new(big.Int).Set(header.Difficulty),
@@ -48,7 +57,7 @@ func NewEVMContext(msg Message, header *types.Header, chain HeaderFetcher) vm.Co
 }
 
 // GetHashFn returns a GetHashFunc which retrieves header hashes by number
-func GetHashFn(ref *types.Header, chain HeaderFetcher) func(n uint64) common.Hash {
+func GetHashFn(ref *types.Header, chain ChainContext) func(n uint64) common.Hash {
 	return func(n uint64) common.Hash {
 		for header := chain.GetHeader(ref.ParentHash, ref.Number.Uint64()-1); header != nil; header = chain.GetHeader(header.ParentHash, header.Number.Uint64()-1) {
 			if header.Number.Uint64() == n {

core/headerchain.go

@@ -442,6 +442,9 @@ func (hc *HeaderChain) SetGenesis(head *types.Header) {
 // Config retrieves the header chain's chain configuration.
 func (hc *HeaderChain) Config() *params.ChainConfig { return hc.config }
 
+// Engine retrieves the header chain's consensus engine.
+func (hc *HeaderChain) Engine() consensus.Engine { return hc.engine }
+
 // GetBlock implements consensus.ChainReader, and returns nil for every input as
 // a header chain does not have blocks available for retrieval.
 func (hc *HeaderChain) GetBlock(hash common.Hash, number uint64) *types.Block {

ethstats/ethstats.go

@@ -30,6 +30,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth"
@@ -54,6 +55,7 @@ type Service struct {
 	server *p2p.Server        // Peer-to-peer server to retrieve networking infos
 	eth    *eth.Ethereum      // Full Ethereum service if monitoring a full node
 	les    *les.LightEthereum // Light Ethereum service if monitoring a light node
+	engine consensus.Engine   // Consensus engine to retrieve variadic block fields
 
 	node string // Name of the node to display on the monitoring page
 	pass string // Password to authorize access to the monitoring page
@@ -72,9 +74,16 @@ func New(url string, ethServ *eth.Ethereum, lesServ *les.LightEthereum) (*Servic
 		return nil, fmt.Errorf("invalid netstats url: \"%s\", should be nodename:secret@host:port", url)
 	}
 	// Assemble and return the stats service
+	var engine consensus.Engine
+	if ethServ != nil {
+		engine = ethServ.Engine()
+	} else {
+		engine = lesServ.Engine()
+	}
 	return &Service{
 		eth:    ethServ,
 		les:    lesServ,
+		engine: engine,
 		node:   parts[1],
 		pass:   parts[3],
 		host:   parts[4],
@@ -493,12 +502,14 @@ func (s *Service) assembleBlockStats(block *types.Block) *blockStats {
 		td = s.les.BlockChain().GetTd(header.Hash(), header.Number.Uint64())
 	}
 	// Assemble and return the block stats
+	author, _ := s.engine.Author(header)
+
 	return &blockStats{
 		Number:     header.Number,
 		Hash:       header.Hash(),
 		ParentHash: header.ParentHash,
 		Timestamp:  header.Time,
-		Miner:      header.Coinbase,
+		Miner:      author,
 		GasUsed:    new(big.Int).Set(header.GasUsed),
 		GasLimit:   new(big.Int).Set(header.GasLimit),
 		Diff:       header.Difficulty.String(),

les/backend.go

@@ -176,6 +176,7 @@ func (s *LightEthereum) ResetWithGenesisBlock(gb *types.Block) {
 
 func (s *LightEthereum) BlockChain() *light.LightChain      { return s.blockchain }
 func (s *LightEthereum) TxPool() *light.TxPool              { return s.txPool }
+func (s *LightEthereum) Engine() consensus.Engine           { return s.engine }
 func (s *LightEthereum) LesVersion() int                    { return int(s.protocolManager.SubProtocols[0].Version) }
 func (s *LightEthereum) Downloader() *downloader.Downloader { return s.protocolManager.downloader }
 func (s *LightEthereum) EventMux() *event.TypeMux           { return s.eventMux }

light/lightchain.go

@@ -213,6 +213,9 @@ func (bc *LightChain) ResetWithGenesisBlock(genesis *types.Block) {
 
 // Accessors
 
+// Engine retrieves the light chain's consensus engine.
+func (bc *LightChain) Engine() consensus.Engine { return bc.engine }
+
 // Genesis returns the genesis block
 func (bc *LightChain) Genesis() *types.Block {
 	return bc.genesisBlock