feat(ethash): flashbots_getWork RPC with profit

Author: shekhirin

cmd/evm/internal/t8ntool/block.go

@@ -188,7 +188,7 @@ func (i *bbInput) sealEthash(block *types.Block) (*types.Block, error) {
 	// If the testmode is used, the sealer will return quickly, and complain
 	// "Sealing result is not read by miner" if it cannot write the result.
 	results := make(chan *types.Block, 1)
-	if err := engine.Seal(nil, block, results, nil); err != nil {
+	if err := engine.Seal(nil, block, nil, results, nil); err != nil {
 		panic(fmt.Sprintf("failed to seal block: %v", err))
 	}
 	found := <-results

cmd/geth/consolecmd_test.go

@@ -31,7 +31,7 @@ import (
 )
 
 const (
-	ipcAPIs  = "admin:1.0 debug:1.0 eth:1.0 ethash:1.0 miner:1.0 net:1.0 personal:1.0 rpc:1.0 txpool:1.0 web3:1.0"
+	ipcAPIs  = "admin:1.0 debug:1.0 eth:1.0 ethash:1.0 flashbots:1.0 miner:1.0 net:1.0 personal:1.0 rpc:1.0 txpool:1.0 web3:1.0"
 	httpAPIs = "eth:1.0 net:1.0 rpc:1.0 web3:1.0"
 )
 

consensus/beacon/consensus.go

@@ -298,9 +298,9 @@ func (beacon *Beacon) FinalizeAndAssemble(chain consensus.ChainHeaderReader, hea
 //
 // Note, the method returns immediately and will send the result async. More
 // than one result may also be returned depending on the consensus algorithm.
-func (beacon *Beacon) Seal(chain consensus.ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error {
+func (beacon *Beacon) Seal(chain consensus.ChainHeaderReader, block *types.Block, profit *big.Int, results chan<- *types.Block, stop <-chan struct{}) error {
 	if !beacon.IsPoSHeader(block.Header()) {
-		return beacon.ethone.Seal(chain, block, results, stop)
+		return beacon.ethone.Seal(chain, block, profit, results, stop)
 	}
 	// The seal verification is done by the external consensus engine,
 	// return directly without pushing any block back. In another word

consensus/clique/clique.go

@@ -589,7 +589,7 @@ func (c *Clique) Authorize(signer common.Address, signFn SignerFn) {
 
 // Seal implements consensus.Engine, attempting to create a sealed block using
 // the local signing credentials.
-func (c *Clique) Seal(chain consensus.ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error {
+func (c *Clique) Seal(chain consensus.ChainHeaderReader, block *types.Block, profit *big.Int, results chan<- *types.Block, stop <-chan struct{}) error {
 	header := block.Header()
 
 	// Sealing the genesis block is not supported

consensus/consensus.go

@@ -105,7 +105,7 @@ type Engine interface {
 	//
 	// Note, the method returns immediately and will send the result async. More
 	// than one result may also be returned depending on the consensus algorithm.
-	Seal(chain ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error
+	Seal(chain ChainHeaderReader, block *types.Block, profit *big.Int, results chan<- *types.Block, stop <-chan struct{}) error
 
 	// SealHash returns the hash of a block prior to it being sealed.
 	SealHash(header *types.Header) common.Hash

consensus/ethash/api.go

@@ -44,7 +44,7 @@ func (api *API) GetWork() ([4]string, error) {
 	}
 
 	var (
-		workCh = make(chan [4]string, 1)
+		workCh = make(chan [5]string, 1)
 		errc   = make(chan error, 1)
 	)
 	select {
@@ -53,7 +53,10 @@ func (api *API) GetWork() ([4]string, error) {
 		return [4]string{}, errEthashStopped
 	}
 	select {
-	case work := <-workCh:
+	case fullWork := <-workCh:
+		var work [4]string
+		copy(work[:], fullWork[:4])
+
 		return work, nil
 	case err := <-errc:
 		return [4]string{}, err

consensus/ethash/ethash.go

@@ -683,6 +683,12 @@ func (ethash *Ethash) APIs(chain consensus.ChainHeaderReader) []rpc.API {
 			Service:   &API{ethash},
 			Public:    true,
 		},
+		{
+			Namespace: "flashbots",
+			Version:   "1.0",
+			Service:   &FlashbotsAPI{ethash},
+			Public:    true,
+		},
 	}
 }
 

consensus/ethash/ethash_test.go

@@ -38,7 +38,7 @@ func TestTestMode(t *testing.T) {
 	defer ethash.Close()
 
 	results := make(chan *types.Block)
-	err := ethash.Seal(nil, types.NewBlockWithHeader(header), results, nil)
+	err := ethash.Seal(nil, types.NewBlockWithHeader(header), nil, results, nil)
 	if err != nil {
 		t.Fatalf("failed to seal block: %v", err)
 	}
@@ -111,7 +111,7 @@ func TestRemoteSealer(t *testing.T) {
 
 	// Push new work.
 	results := make(chan *types.Block)
-	ethash.Seal(nil, block, results, nil)
+	ethash.Seal(nil, block, nil, results, nil)
 
 	var (
 		work [4]string
@@ -128,7 +128,7 @@ func TestRemoteSealer(t *testing.T) {
 	header = &types.Header{Number: big.NewInt(1), Difficulty: big.NewInt(1000)}
 	block = types.NewBlockWithHeader(header)
 	sealhash = ethash.SealHash(header)
-	ethash.Seal(nil, block, results, nil)
+	ethash.Seal(nil, block, nil, results, nil)
 
 	if work, err = api.GetWork(); err != nil || work[0] != sealhash.Hex() {
 		t.Error("expect to return the latest pushed work")

consensus/ethash/flashbots_api.go

@@ -0,0 +1,38 @@
+package ethash
+
+import "errors"
+
+// FlashbotsAPI exposes Flashbots related methods for the RPC interface.
+type FlashbotsAPI struct {
+	ethash *Ethash
+}
+
+// GetWork returns a work package for external miner.
+//
+// The work package consists of 5 strings:
+//   result[0] - 32 bytes hex encoded current block header pow-hash
+//   result[1] - 32 bytes hex encoded seed hash used for DAG
+//   result[2] - 32 bytes hex encoded boundary condition ("target"), 2^256/difficulty
+//   result[3] - hex encoded block number
+//   result[4] - hex encoded profit generated from this block
+func (api *FlashbotsAPI) GetWork() ([5]string, error) {
+	if api.ethash.remote == nil {
+		return [5]string{}, errors.New("not supported")
+	}
+
+	var (
+		workCh = make(chan [5]string, 1)
+		errc   = make(chan error, 1)
+	)
+	select {
+	case api.ethash.remote.fetchWorkCh <- &sealWork{errc: errc, res: workCh}:
+	case <-api.ethash.remote.exitCh:
+		return [5]string{}, errEthashStopped
+	}
+	select {
+	case work := <-workCh:
+		return work, nil
+	case err := <-errc:
+		return [5]string{}, err
+	}
+}

consensus/ethash/sealer.go

@@ -48,7 +48,7 @@ var (
 
 // Seal implements consensus.Engine, attempting to find a nonce that satisfies
 // the block's difficulty requirements.
-func (ethash *Ethash) Seal(chain consensus.ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error {
+func (ethash *Ethash) Seal(chain consensus.ChainHeaderReader, block *types.Block, profit *big.Int, results chan<- *types.Block, stop <-chan struct{}) error {
 	// If we're running a fake PoW, simply return a 0 nonce immediately
 	if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
 		header := block.Header()
@@ -62,7 +62,7 @@ func (ethash *Ethash) Seal(chain consensus.ChainHeaderReader, block *types.Block
 	}
 	// If we're running a shared PoW, delegate sealing to it
 	if ethash.shared != nil {
-		return ethash.shared.Seal(chain, block, results, stop)
+		return ethash.shared.Seal(chain, block, profit, results, stop)
 	}
 	// Create a runner and the multiple search threads it directs
 	abort := make(chan struct{})
@@ -86,7 +86,7 @@ func (ethash *Ethash) Seal(chain consensus.ChainHeaderReader, block *types.Block
 	}
 	// Push new work to remote sealer
 	if ethash.remote != nil {
-		ethash.remote.workCh <- &sealTask{block: block, results: results}
+		ethash.remote.workCh <- &sealTask{block: block, profit: profit, results: results}
 	}
 	var (
 		pend   sync.WaitGroup
@@ -117,7 +117,7 @@ func (ethash *Ethash) Seal(chain consensus.ChainHeaderReader, block *types.Block
 		case <-ethash.update:
 			// Thread count was changed on user request, restart
 			close(abort)
-			if err := ethash.Seal(chain, block, results, stop); err != nil {
+			if err := ethash.Seal(chain, block, profit, results, stop); err != nil {
 				ethash.config.Log.Error("Failed to restart sealing after update", "err", err)
 			}
 		}
@@ -194,7 +194,7 @@ type remoteSealer struct {
 	works        map[common.Hash]*types.Block
 	rates        map[common.Hash]hashrate
 	currentBlock *types.Block
-	currentWork  [4]string
+	currentWork  [5]string
 	notifyCtx    context.Context
 	cancelNotify context.CancelFunc // cancels all notification requests
 	reqWG        sync.WaitGroup     // tracks notification request goroutines
@@ -215,6 +215,7 @@ type remoteSealer struct {
 // sealTask wraps a seal block with relative result channel for remote sealer thread.
 type sealTask struct {
 	block   *types.Block
+	profit  *big.Int
 	results chan<- *types.Block
 }
 
@@ -239,7 +240,7 @@ type hashrate struct {
 // sealWork wraps a seal work package for remote sealer.
 type sealWork struct {
 	errc chan error
-	res  chan [4]string
+	res  chan [5]string
 }
 
 func startRemoteSealer(ethash *Ethash, urls []string, noverify bool) *remoteSealer {
@@ -281,7 +282,7 @@ func (s *remoteSealer) loop() {
 			// Update current work with new received block.
 			// Note same work can be past twice, happens when changing CPU threads.
 			s.results = work.results
-			s.makeWork(work.block)
+			s.makeWork(work.block, work.profit)
 			s.notifyWork()
 
 		case work := <-s.fetchWorkCh:
@@ -338,18 +339,23 @@ func (s *remoteSealer) loop() {
 
 // makeWork creates a work package for external miner.
 //
-// The work package consists of 3 strings:
+// The work package consists of 5 strings:
 //   result[0], 32 bytes hex encoded current block header pow-hash
 //   result[1], 32 bytes hex encoded seed hash used for DAG
 //   result[2], 32 bytes hex encoded boundary condition ("target"), 2^256/difficulty
 //   result[3], hex encoded block number
-func (s *remoteSealer) makeWork(block *types.Block) {
+//   result[4], hex encoded profit generated from this block, if present
+func (s *remoteSealer) makeWork(block *types.Block, profit *big.Int) {
 	hash := s.ethash.SealHash(block.Header())
 	s.currentWork[0] = hash.Hex()
 	s.currentWork[1] = common.BytesToHash(SeedHash(block.NumberU64())).Hex()
 	s.currentWork[2] = common.BytesToHash(new(big.Int).Div(two256, block.Difficulty()).Bytes()).Hex()
 	s.currentWork[3] = hexutil.EncodeBig(block.Number())
 
+	if profit != nil {
+		s.currentWork[4] = hexutil.EncodeBig(profit)
+	}
+
 	// Trace the seal work fetched by remote sealer.
 	s.currentBlock = block
 	s.works[hash] = block
@@ -375,7 +381,7 @@ func (s *remoteSealer) notifyWork() {
 	}
 }
 
-func (s *remoteSealer) sendNotification(ctx context.Context, url string, json []byte, work [4]string) {
+func (s *remoteSealer) sendNotification(ctx context.Context, url string, json []byte, work [5]string) {
 	defer s.reqWG.Done()
 
 	req, err := http.NewRequest("POST", url, bytes.NewReader(json))