mev_callBundle support

consensus/bor/bor.go

@@ -637,6 +637,16 @@ func (c *Bor) snapshot(chain consensus.ChainHeaderReader, number uint64, hash co
 	return snap, err
 }
 
+// CallBundle API requires the proposer at the specified block
+func (c *Bor) GetProposer(chain consensus.ChainHeaderReader, parent *types.Header) (common.Address, error) {
+	snap, err := c.snapshot(chain, parent.Number.Uint64(), parent.Hash(), nil)
+	if err != nil {
+		return common.Address{}, err
+	}
+
+	return snap.ValidatorSet.GetProposer().Address, nil
+}
+
 // VerifyUncles implements consensus.Engine, always returning an error for any
 // uncles as this consensus mechanism doesn't permit uncles.
 func (c *Bor) VerifyUncles(_ consensus.ChainReader, block *types.Block) error {

core/state_processor.go

@@ -205,3 +205,59 @@ func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *commo
 
 	return applyTransaction(msg, config, bc, author, gp, statedb, header.Number, header.Hash(), tx, usedGas, vmenv, interruptCtx)
 }
+
+func applyTransactionWithResult(msg types.Message, config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, evm *vm.EVM, interruptCtx context.Context) (*types.Receipt, *ExecutionResult, error) {
+	// Create a new context to be used in the EVM environment.
+	txContext := NewEVMTxContext(msg)
+	evm.Reset(txContext, statedb)
+
+	// Apply the transaction to the current state (included in the env).
+	result, err := ApplyMessage(evm, msg, gp, interruptCtx)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Update the state with pending changes.
+	var root []byte
+	if config.IsByzantium(header.Number) {
+		statedb.Finalise(true)
+	} else {
+		root = statedb.IntermediateRoot(config.IsEIP158(header.Number)).Bytes()
+	}
+	*usedGas += result.UsedGas
+
+	// Create a new receipt for the transaction, storing the intermediate root and gas used
+	// by the tx.
+	receipt := &types.Receipt{Type: tx.Type(), PostState: root, CumulativeGasUsed: *usedGas}
+	if result.Failed() {
+		receipt.Status = types.ReceiptStatusFailed
+	} else {
+		receipt.Status = types.ReceiptStatusSuccessful
+	}
+	receipt.TxHash = tx.Hash()
+	receipt.GasUsed = result.UsedGas
+
+	// If the transaction created a contract, store the creation address in the receipt.
+	if msg.To() == nil {
+		receipt.ContractAddress = crypto.CreateAddress(evm.TxContext.Origin, tx.Nonce())
+	}
+
+	// Set the receipt logs and create the bloom filter.
+	receipt.Logs = statedb.GetLogs(tx.Hash(), header.Hash())
+	receipt.Bloom = types.CreateBloom(types.Receipts{receipt})
+	receipt.BlockHash = header.Hash()
+	receipt.BlockNumber = header.Number
+	receipt.TransactionIndex = uint(statedb.TxIndex())
+	return receipt, result, err
+}
+
+func ApplyTransactionWithResult(config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, cfg vm.Config, interruptCtx context.Context) (*types.Receipt, *ExecutionResult, error) {
+	msg, err := tx.AsMessage(types.MakeSigner(config, header.Number), header.BaseFee)
+	if err != nil {
+		return nil, nil, err
+	}
+	// Create a new context to be used in the EVM environment
+	blockContext := NewEVMBlockContext(header, bc, author)
+	vmenv := vm.NewEVM(blockContext, vm.TxContext{}, statedb, config, cfg)
+	return applyTransactionWithResult(msg, config, bc, author, gp, statedb, header, tx, usedGas, vmenv, interruptCtx)
+}

eth/backend.go

@@ -330,7 +330,7 @@ func makeExtraData(extra []byte) []byte {
 // APIs return the collection of RPC services the ethereum package offers.
 // NOTE, some of these services probably need to be moved to somewhere else.
 func (s *Ethereum) APIs() []rpc.API {
-	apis := ethapi.GetAPIs(s.APIBackend)
+	apis := ethapi.GetAPIs(s.APIBackend, s.BlockChain())
 
 	// Append any APIs exposed explicitly by the consensus engine
 	apis = append(apis, s.engine.APIs(s.BlockChain())...)

internal/ethapi/api.go

@@ -18,6 +18,7 @@ package ethapi
 
 import (
 	"context"
+	"encoding/hex"
 	"errors"
 	"fmt"
 	"math/big"
@@ -35,6 +36,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/consensus/clique"
 	"github.com/ethereum/go-ethereum/consensus/ethash"
 	"github.com/ethereum/go-ethereum/consensus/misc"
@@ -51,6 +53,7 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc"
+	"golang.org/x/crypto/sha3"
 )
 
 // PublicEthereumAPI provides an API to access Ethereum related information.
@@ -2343,12 +2346,13 @@ func toHexSlice(b [][]byte) []string {
 
 // PrivateTxBundleAPI offers an API for accepting bundled transactions
 type PrivateTxBundleAPI struct {
-	b Backend
+	b     Backend
+	chain *core.BlockChain
 }
 
 // NewPrivateTxBundleAPI creates a new Tx Bundle API instance.
-func NewPrivateTxBundleAPI(b Backend) *PrivateTxBundleAPI {
-	return &PrivateTxBundleAPI{b}
+func NewPrivateTxBundleAPI(b Backend, chain *core.BlockChain) *PrivateTxBundleAPI {
+	return &PrivateTxBundleAPI{b, chain}
 }
 
 // SendBundleArgs represents the arguments for a call.
@@ -2389,3 +2393,208 @@ func (s *PrivateTxBundleAPI) SendBundle(ctx context.Context, args SendBundleArgs
 
 	return s.b.SendBundle(ctx, txs, args.BlockNumber, minTimestamp, maxTimestamp, args.RevertingTxHashes)
 }
+
+// CallBundleArgs represents the arguments for a call.
+type CallBundleArgs struct {
+	Txs                    []hexutil.Bytes       `json:"txs"`
+	BlockNumber            rpc.BlockNumber       `json:"blockNumber"`
+	StateBlockNumberOrHash rpc.BlockNumberOrHash `json:"stateBlockNumber"`
+	Coinbase               *string               `json:"coinbase"`
+	Timestamp              *uint64               `json:"timestamp"`
+	Timeout                *int64                `json:"timeout"`
+	GasLimit               *uint64               `json:"gasLimit"`
+	Difficulty             *big.Int              `json:"difficulty"`
+	BaseFee                *big.Int              `json:"baseFee"`
+}
+
+// CallBundle will simulate a bundle of transactions at the top of a given block
+// number with the state of another (or the same) block. This can be used to
+// simulate future blocks with the current state, or it can be used to simulate
+// a past block.
+// The sender is responsible for signing the transactions and using the correct
+// nonce and ensuring validity
+func (s *PrivateTxBundleAPI) CallBundle(ctx context.Context, args CallBundleArgs) (map[string]interface{}, error) {
+	if len(args.Txs) == 0 {
+		return nil, errors.New("bundle missing txs")
+	}
+	if args.BlockNumber == 0 {
+		return nil, errors.New("bundle missing blockNumber")
+	}
+
+	var txs types.Transactions
+
+	for _, encodedTx := range args.Txs {
+		tx := new(types.Transaction)
+		if err := tx.UnmarshalBinary(encodedTx); err != nil {
+			return nil, err
+		}
+		txs = append(txs, tx)
+	}
+	defer func(start time.Time) { log.Debug("Executing EVM call finished", "runtime", time.Since(start)) }(time.Now())
+
+	timeoutMilliSeconds := int64(5000)
+	if args.Timeout != nil {
+		timeoutMilliSeconds = *args.Timeout
+	}
+	timeout := time.Millisecond * time.Duration(timeoutMilliSeconds)
+	state, parent, err := s.b.StateAndHeaderByNumberOrHash(ctx, args.StateBlockNumberOrHash)
+	if state == nil || err != nil {
+		return nil, err
+	}
+	blockNumber := big.NewInt(int64(args.BlockNumber))
+
+	// Reject mev-bor requests with invalid block numbers
+	// TODO: Add API to engine interface
+	type BorInfo interface {
+		GetProposer(chain consensus.ChainHeaderReader, parent *types.Header) (common.Address, error)
+	}
+
+	bor, isBorEngine := s.b.Engine().(BorInfo)
+	if isBorEngine && parent.Number.Uint64() != s.chain.CurrentHeader().Number.Uint64() {
+		return nil, errors.New("Please simulate on top of the latest block!")
+	}
+
+	if isBorEngine && blockNumber.Uint64() != parent.Number.Uint64()+1 {
+		return nil, errors.New("Please target the in-progress block for simulation!")
+	}
+
+	timestamp := parent.Time + 1
+	if args.Timestamp != nil {
+		timestamp = *args.Timestamp
+	}
+	var coinbase common.Address
+	if args.Coinbase != nil {
+		coinbase = common.HexToAddress(*args.Coinbase)
+	} else {
+		if isBorEngine {
+			coinbase, err = bor.GetProposer(s.chain, parent)
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			coinbase = parent.Coinbase
+		}
+	}
+	difficulty := parent.Difficulty
+	if args.Difficulty != nil {
+		difficulty = args.Difficulty
+	}
+	gasLimit := parent.GasLimit
+	if args.GasLimit != nil {
+		gasLimit = *args.GasLimit
+	}
+	var baseFee *big.Int
+	if args.BaseFee != nil {
+		baseFee = args.BaseFee
+	} else if s.b.ChainConfig().IsLondon(big.NewInt(args.BlockNumber.Int64())) {
+		baseFee = misc.CalcBaseFee(s.b.ChainConfig(), parent)
+	}
+	header := &types.Header{
+		ParentHash: parent.Hash(),
+		Number:     blockNumber,
+		GasLimit:   gasLimit,
+		Time:       timestamp,
+		Difficulty: difficulty,
+		Coinbase:   coinbase,
+		BaseFee:    baseFee,
+	}
+
+	// Setup context so it may be cancelled the call has completed
+	// or, in case of unmetered gas, setup a context with a timeout.
+	var cancel context.CancelFunc
+	if timeout > 0 {
+		ctx, cancel = context.WithTimeout(ctx, timeout)
+	} else {
+		ctx, cancel = context.WithCancel(ctx)
+	}
+	// Make sure the context is cancelled when the call has completed
+	// this makes sure resources are cleaned up.
+	defer cancel()
+
+	vmconfig := vm.Config{}
+
+	// Setup the gas pool (also for unmetered requests)
+	// and apply the message.
+	gp := new(core.GasPool).AddGas(math.MaxUint64)
+
+	results := []map[string]interface{}{}
+	coinbaseBalanceBefore := state.GetBalance(coinbase)
+
+	bundleHash := sha3.NewLegacyKeccak256()
+	signer := types.MakeSigner(s.b.ChainConfig(), blockNumber)
+	var totalGasUsed uint64
+	gasFees := new(big.Int)
+	for i, tx := range txs {
+		coinbaseBalanceBeforeTx := state.GetBalance(coinbase)
+		state.Prepare(tx.Hash(), i)
+
+		receipt, result, err := core.ApplyTransactionWithResult(s.b.ChainConfig(), s.chain, &coinbase, gp, state, header, tx, &header.GasUsed, vmconfig, ctx)
+		if err != nil {
+			return nil, fmt.Errorf("err: %w; txhash %s", err, tx.Hash())
+		}
+
+		txHash := tx.Hash().String()
+		from, err := types.Sender(signer, tx)
+		if err != nil {
+			return nil, fmt.Errorf("err: %w; txhash %s", err, tx.Hash())
+		}
+		to := "0x"
+		if tx.To() != nil {
+			to = tx.To().String()
+		}
+		jsonResult := map[string]interface{}{
+			"txHash":      txHash,
+			"gasUsed":     receipt.GasUsed,
+			"fromAddress": from.String(),
+			"toAddress":   to,
+		}
+		totalGasUsed += receipt.GasUsed
+		gasPrice, err := tx.EffectiveGasTip(header.BaseFee)
+		if err != nil {
+			return nil, fmt.Errorf("err: %w; txhash %s", err, tx.Hash())
+		}
+		gasFeesTx := new(big.Int).Mul(big.NewInt(int64(receipt.GasUsed)), gasPrice)
+		gasFees.Add(gasFees, gasFeesTx)
+		bundleHash.Write(tx.Hash().Bytes())
+		if result.Err != nil {
+			jsonResult["error"] = result.Err.Error()
+			revert := result.Revert()
+			if len(revert) > 0 {
+				jsonResult["revert"] = string(revert)
+			}
+		} else {
+			dst := make([]byte, hex.EncodedLen(len(result.Return())))
+			hex.Encode(dst, result.Return())
+			jsonResult["value"] = "0x" + string(dst)
+		}
+		coinbaseDiffTx := new(big.Int).Sub(state.GetBalance(coinbase), coinbaseBalanceBeforeTx)
+		jsonResult["coinbaseDiff"] = coinbaseDiffTx.String()
+		jsonResult["gasFees"] = gasFeesTx.String()
+		jsonResult["ethSentToCoinbase"] = new(big.Int).Sub(coinbaseDiffTx, gasFeesTx).String()
+		jsonResult["gasPrice"] = new(big.Int).Div(coinbaseDiffTx, big.NewInt(int64(receipt.GasUsed))).String()
+		jsonResult["gasUsed"] = receipt.GasUsed
+		results = append(results, jsonResult)
+	}
+
+	ret := map[string]interface{}{}
+	ret["results"] = results
+	coinbaseDiff := new(big.Int).Sub(state.GetBalance(coinbase), coinbaseBalanceBefore)
+	ret["coinbaseDiff"] = coinbaseDiff.String()
+	ret["gasFees"] = gasFees.String()
+	ret["ethSentToCoinbase"] = new(big.Int).Sub(coinbaseDiff, gasFees).String()
+	ret["bundleGasPrice"] = new(big.Int).Div(coinbaseDiff, big.NewInt(int64(totalGasUsed))).String()
+	ret["totalGasUsed"] = totalGasUsed
+	ret["stateBlockNumber"] = parent.Number.Int64()
+
+	ret["bundleHash"] = "0x" + common.Bytes2Hex(bundleHash.Sum(nil))
+
+	// Retrieve block producer in bor when available
+	if isBorEngine {
+		proposer, err := bor.GetProposer(s.chain, parent)
+		if err == nil {
+			ret["proposer"] = proposer.Hex()
+		}
+	}
+
+	return ret, nil
+}

internal/ethapi/backend.go

@@ -110,7 +110,7 @@ type Backend interface {
 	Engine() consensus.Engine
 }
 
-func GetAPIs(apiBackend Backend) []rpc.API {
+func GetAPIs(apiBackend Backend, chain *core.BlockChain) []rpc.API {
 	nonceLock := new(AddrLocker)
 	return []rpc.API{
 		{
@@ -155,7 +155,7 @@ func GetAPIs(apiBackend Backend) []rpc.API {
 		}, {
 			Namespace: "mev",
 			Version:   "1.0",
-			Service:   NewPrivateTxBundleAPI(apiBackend),
+			Service:   NewPrivateTxBundleAPI(apiBackend, chain),
 			Public:    false,
 		},
 	}

les/client.go

@@ -283,7 +283,7 @@ func (s *LightDummyAPI) Mining() bool {
 // APIs returns the collection of RPC services the ethereum package offers.
 // NOTE, some of these services probably need to be moved to somewhere else.
 func (s *LightEthereum) APIs() []rpc.API {
-	apis := ethapi.GetAPIs(s.ApiBackend)
+	apis := ethapi.GetAPIs(s.ApiBackend, nil)
 	apis = append(apis, s.engine.APIs(s.BlockChain().HeaderChain())...)
 	return append(apis, []rpc.API{
 		{