handle holocene EIP-1559 params

beacon/engine/types.go

@@ -56,14 +56,19 @@ type PayloadAttributes struct {
 	NoTxPool bool `json:"noTxPool,omitempty" gencodec:"optional"`
 	// GasLimit is a field for rollups: if set, this sets the exact gas limit the block produced with.
 	GasLimit *uint64 `json:"gasLimit,omitempty" gencodec:"optional"`
+	// EIP1559Params is a field for rollups implementing the Holocene upgrade,
+	// and contains encoded EIP-1559 parameters. See:
+	// https://github.com/ethereum-optimism/specs/blob/main/specs/protocol/holocene/exec-engine.md#eip1559params-encoding
+	EIP1559Params []byte `json:"eip1559Params,omitempty" gencodec:"optional"`
 }
 
 // JSON type overrides for PayloadAttributes.
 type payloadAttributesMarshaling struct {
 	Timestamp hexutil.Uint64
 
-	Transactions []hexutil.Bytes
-	GasLimit     *hexutil.Uint64
+	Transactions  []hexutil.Bytes
+	GasLimit      *hexutil.Uint64
+	EIP1559Params hexutil.Bytes
 }
 
 //go:generate go run github.com/fjl/gencodec -type ExecutableData -field-override executableDataMarshaling -out gen_ed.go

consensus/misc/eip1559/eip1559.go

@@ -17,6 +17,7 @@
 package eip1559
 
 import (
+	"encoding/binary"
 	"errors"
 	"fmt"
 	"math/big"
@@ -55,15 +56,31 @@ func VerifyEIP1559Header(config *params.ChainConfig, parent, header *types.Heade
 	return nil
 }
 
+// DecodeHolocene1599Params extracts the Holcene 1599 parameters from the encoded form:
+// https://github.com/ethereum-optimism/specs/blob/main/specs/protocol/holocene/exec-engine.md#eip1559params-encoding
+func DecodeHolocene1559Params(nonce types.BlockNonce) (uint64, uint64) {
+	elasticity := binary.BigEndian.Uint32(nonce[4:])
+	denominator := binary.BigEndian.Uint32(nonce[:4])
+	return uint64(elasticity), uint64(denominator)
+}
+
 // CalcBaseFee calculates the basefee of the header.
-// The time belongs to the new block to check if Canyon is activted or not
+// The time belongs to the new block to check which upgrades are active.
 func CalcBaseFee(config *params.ChainConfig, parent *types.Header, time uint64) *big.Int {
 	// If the current block is the first EIP-1559 block, return the InitialBaseFee.
 	if !config.IsLondon(parent.Number) {
 		return new(big.Int).SetUint64(params.InitialBaseFee)
 	}
-
-	parentGasTarget := parent.GasLimit / config.ElasticityMultiplier()
+	elasticity := config.ElasticityMultiplier()
+	denominator := config.BaseFeeChangeDenominator(time)
+	if config.IsHolocene(time) {
+		// Holocene requires we get the 1559 parameters from the nonce field of parent header,
+		// unless the field is zero, in which case we use the Canyon values.
+		if parent.Nonce != types.BlockNonce([8]byte{}) {
+			elasticity, denominator = DecodeHolocene1559Params(parent.Nonce)
+		}
+	}
+	parentGasTarget := parent.GasLimit / elasticity
 	// If the parent gasUsed is the same as the target, the baseFee remains unchanged.
 	if parent.GasUsed == parentGasTarget {
 		return new(big.Int).Set(parent.BaseFee)
@@ -80,7 +97,7 @@ func CalcBaseFee(config *params.ChainConfig, parent *types.Header, time uint64)
 		num.SetUint64(parent.GasUsed - parentGasTarget)
 		num.Mul(num, parent.BaseFee)
 		num.Div(num, denom.SetUint64(parentGasTarget))
-		num.Div(num, denom.SetUint64(config.BaseFeeChangeDenominator(time)))
+		num.Div(num, denom.SetUint64(denominator))
 		baseFeeDelta := math.BigMax(num, common.Big1)
 
 		return num.Add(parent.BaseFee, baseFeeDelta)
@@ -90,7 +107,7 @@ func CalcBaseFee(config *params.ChainConfig, parent *types.Header, time uint64)
 		num.SetUint64(parentGasTarget - parent.GasUsed)
 		num.Mul(num, parent.BaseFee)
 		num.Div(num, denom.SetUint64(parentGasTarget))
-		num.Div(num, denom.SetUint64(config.BaseFeeChangeDenominator(time)))
+		num.Div(num, denom.SetUint64(denominator))
 		baseFee := num.Sub(parent.BaseFee, num)
 
 		return math.BigMax(baseFee, common.Big0)

consensus/misc/eip1559/eip1559_test.go

@@ -17,6 +17,7 @@
 package eip1559
 
 import (
+	"encoding/binary"
 	"math/big"
 	"testing"
 
@@ -61,6 +62,8 @@ func opConfig() *params.ChainConfig {
 	ct := uint64(10)
 	eip1559DenominatorCanyon := uint64(250)
 	config.CanyonTime = &ct
+	ht := uint64(12)
+	config.HoloceneTime = &ht
 	config.Optimism = &params.OptimismConfig{
 		EIP1559Elasticity:        6,
 		EIP1559Denominator:       50,
@@ -174,5 +177,54 @@ func TestCalcBaseFeeOptimism(t *testing.T) {
 		if have, want := CalcBaseFee(opConfig(), parent, parent.Time+2), big.NewInt(test.expectedBaseFee); have.Cmp(want) != 0 {
 			t.Errorf("test %d: have %d  want %d, ", i, have, want)
 		}
+		if test.postCanyon {
+			// make sure Holocene activation doesn't change the outcome; since these tests have a
+			// zero nonce, they should be handled using the Canyon config.
+			parent.Time = 10
+			if have, want := CalcBaseFee(opConfig(), parent, parent.Time+2), big.NewInt(test.expectedBaseFee); have.Cmp(want) != 0 {
+				t.Errorf("test %d: have %d  want %d, ", i, have, want)
+			}
+		}
+	}
+}
+
+func encodeHolocene1559Params(elasticity, denom uint32) types.BlockNonce {
+	var nonce types.BlockNonce
+	binary.BigEndian.PutUint32(nonce[4:], elasticity)
+	binary.BigEndian.PutUint32(nonce[:4], denom)
+	return nonce
+}
+
+// TestCalcBaseFeeHolocene assumes all blocks are Optimism blocks post-Holocene upgrade
+func TestCalcBaseFeeOptimismHolocene(t *testing.T) {
+	elasticity2Denom10Nonce := encodeHolocene1559Params(2, 10)
+	elasticity10Denom2Nonce := encodeHolocene1559Params(10, 2)
+	parentBaseFee := int64(10_000_000)
+	parentGasLimit := uint64(30_000_000)
+
+	tests := []struct {
+		parentGasUsed   uint64
+		expectedBaseFee int64
+		nonce           types.BlockNonce
+	}{
+		{parentGasLimit / 2, parentBaseFee, elasticity2Denom10Nonce},  // target
+		{10_000_000, 9_666_667, elasticity2Denom10Nonce},              // below
+		{20_000_000, 10_333_333, elasticity2Denom10Nonce},             // above
+		{parentGasLimit / 10, parentBaseFee, elasticity10Denom2Nonce}, // target
+		{1_000_000, 6_666_667, elasticity10Denom2Nonce},               // below
+		{30_000_000, 55_000_000, elasticity10Denom2Nonce},             // above
+	}
+	for i, test := range tests {
+		parent := &types.Header{
+			Number:   common.Big32,
+			GasLimit: parentGasLimit,
+			GasUsed:  test.parentGasUsed,
+			BaseFee:  big.NewInt(parentBaseFee),
+			Time:     10,
+			Nonce:    test.nonce,
+		}
+		if have, want := CalcBaseFee(opConfig(), parent, parent.Time+2), big.NewInt(test.expectedBaseFee); have.Cmp(want) != 0 {
+			t.Errorf("test %d: have %d  want %d, ", i, have, want)
+		}
 	}
 }

eth/catalyst/api.go

@@ -435,8 +435,17 @@ func (api *ConsensusAPI) forkchoiceUpdated(update engine.ForkchoiceStateV1, payl
 	// sealed by the beacon client. The payload will be requested later, and we
 	// will replace it arbitrarily many times in between.
 	if payloadAttributes != nil {
-		if api.eth.BlockChain().Config().Optimism != nil && payloadAttributes.GasLimit == nil {
-			return engine.STATUS_INVALID, engine.InvalidPayloadAttributes.With(errors.New("gasLimit parameter is required"))
+		if api.eth.BlockChain().Config().Optimism != nil {
+			if payloadAttributes.GasLimit == nil {
+				return engine.STATUS_INVALID, engine.InvalidPayloadAttributes.With(errors.New("gasLimit parameter is required"))
+			}
+			if api.eth.BlockChain().Config().IsHolocene(payloadAttributes.Timestamp) {
+				if payloadAttributes.EIP1559Params == nil {
+					return engine.STATUS_INVALID, engine.InvalidPayloadAttributes.With(errors.New("eip1559Params parameter is required"))
+				}
+			} else if payloadAttributes.EIP1559Params != nil {
+				return engine.STATUS_INVALID, engine.InvalidPayloadAttributes.With(errors.New("eip155Params not supported prior to Holocene upgrade"))
+			}
 		}
 		transactions := make(types.Transactions, 0, len(payloadAttributes.Transactions))
 		for i, otx := range payloadAttributes.Transactions {

miner/payload_building.go

@@ -47,9 +47,10 @@ type BuildPayloadArgs struct {
 	BeaconRoot   *common.Hash          // The provided beaconRoot (Cancun)
 	Version      engine.PayloadVersion // Versioning byte for payload id calculation.
 
-	NoTxPool     bool                 // Optimism addition: option to disable tx pool contents from being included
-	Transactions []*types.Transaction // Optimism addition: txs forced into the block via engine API
-	GasLimit     *uint64              // Optimism addition: override gas limit of the block to build
+	NoTxPool      bool                 // Optimism addition: option to disable tx pool contents from being included
+	Transactions  []*types.Transaction // Optimism addition: txs forced into the block via engine API
+	GasLimit      *uint64              // Optimism addition: override gas limit of the block to build
+	EIP1559Params *types.BlockNonce    // Optimism addition: encodes Holocene EIP-1559 params
 }
 
 // Id computes an 8-byte identifier by hashing the components of the payload arguments.
@@ -75,6 +76,9 @@ func (args *BuildPayloadArgs) Id() engine.PayloadID {
 	if args.GasLimit != nil {
 		binary.Write(hasher, binary.BigEndian, *args.GasLimit)
 	}
+	if args.EIP1559Params != nil {
+		hasher.Write(args.EIP1559Params[:])
+	}
 
 	var out engine.PayloadID
 	copy(out[:], hasher.Sum(nil)[:8])
@@ -280,16 +284,17 @@ func (miner *Miner) buildPayload(args *BuildPayloadArgs, witness bool) (*Payload
 		// to deliver for not missing slot.
 		// In OP-Stack, the "empty" block is constructed from provided txs only, i.e. no tx-pool usage.
 		emptyParams := &generateParams{
-			timestamp:   args.Timestamp,
-			forceTime:   true,
-			parentHash:  args.Parent,
-			coinbase:    args.FeeRecipient,
-			random:      args.Random,
-			withdrawals: args.Withdrawals,
-			beaconRoot:  args.BeaconRoot,
-			noTxs:       true,
-			txs:         args.Transactions,
-			gasLimit:    args.GasLimit,
+			timestamp:     args.Timestamp,
+			forceTime:     true,
+			parentHash:    args.Parent,
+			coinbase:      args.FeeRecipient,
+			random:        args.Random,
+			withdrawals:   args.Withdrawals,
+			beaconRoot:    args.BeaconRoot,
+			noTxs:         true,
+			txs:           args.Transactions,
+			gasLimit:      args.GasLimit,
+			eip1559Params: args.EIP1559Params,
 		}
 		empty := miner.generateWork(emptyParams, witness)
 		if empty.err != nil {
@@ -304,16 +309,17 @@ func (miner *Miner) buildPayload(args *BuildPayloadArgs, witness bool) (*Payload
 	}
 
 	fullParams := &generateParams{
-		timestamp:   args.Timestamp,
-		forceTime:   true,
-		parentHash:  args.Parent,
-		coinbase:    args.FeeRecipient,
-		random:      args.Random,
-		withdrawals: args.Withdrawals,
-		beaconRoot:  args.BeaconRoot,
-		noTxs:       false,
-		txs:         args.Transactions,
-		gasLimit:    args.GasLimit,
+		timestamp:     args.Timestamp,
+		forceTime:     true,
+		parentHash:    args.Parent,
+		coinbase:      args.FeeRecipient,
+		random:        args.Random,
+		withdrawals:   args.Withdrawals,
+		beaconRoot:    args.BeaconRoot,
+		noTxs:         false,
+		txs:           args.Transactions,
+		gasLimit:      args.GasLimit,
+		eip1559Params: args.EIP1559Params,
 	}
 
 	// Since we skip building the empty block when using the tx pool, we need to explicitly