eth,params,forks: add forks package with forks enum and LatestActive method on config

eth/catalyst/api.go

@@ -33,7 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/miner"
 	"github.com/ethereum/go-ethereum/node"
-	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/params/forks"
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
@@ -192,7 +192,7 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV2(update engine.ForkchoiceStateV1, pa
 		if params.BeaconRoot != nil {
 			return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("unexpected beacon root"))
 		}
-		if !latestActive(api.eth.BlockChain().Config(), "shanghai", params.Timestamp) {
+		if api.eth.BlockChain().Config().LatestFork(params.Timestamp) != forks.Shanghai {
 			return engine.STATUS_INVALID, engine.UnsupportedFork.With(errors.New("forkchoiceUpdatedV2 must only be called for shanghai payloads"))
 		}
 	}
@@ -208,8 +208,8 @@ func (api *ConsensusAPI) ForkchoiceUpdatedV3(update engine.ForkchoiceStateV1, pa
 		if params.BeaconRoot == nil {
 			return engine.STATUS_INVALID, engine.InvalidParams.With(errors.New("missing beacon root"))
 		}
-		if !latestActive(api.eth.BlockChain().Config(), "cancun", params.Timestamp) {
-			return engine.STATUS_INVALID, engine.UnsupportedFork.With(errors.New("forkchoiceUpdatedV3 must only be called for shanghai payloads"))
+		if api.eth.BlockChain().Config().LatestFork(params.Timestamp) != forks.Cancun {
+			return engine.STATUS_INVALID, engine.UnsupportedFork.With(errors.New("forkchoiceUpdatedV3 must only be called for cancun payloads"))
 		}
 	}
 	return api.forkchoiceUpdated(update, params)
@@ -445,7 +445,7 @@ func (api *ConsensusAPI) NewPayloadV1(params engine.ExecutableData) (engine.Payl
 
 // NewPayloadV2 creates an Eth1 block, inserts it in the chain, and returns the status of the chain.
 func (api *ConsensusAPI) NewPayloadV2(params engine.ExecutableData) (engine.PayloadStatusV1, error) {
-	if latestActive(api.eth.BlockChain().Config(), "shanghai", params.Timestamp) {
+	if api.eth.BlockChain().Config().LatestFork(params.Timestamp) == forks.Shanghai {
 		if params.Withdrawals == nil {
 			return engine.PayloadStatusV1{Status: engine.INVALID}, engine.InvalidParams.With(errors.New("nil withdrawals post-shanghai"))
 		}
@@ -482,33 +482,12 @@ func (api *ConsensusAPI) NewPayloadV3(params engine.ExecutableData, versionedHas
 		return engine.PayloadStatusV1{Status: engine.INVALID}, engine.InvalidParams.With(errors.New("nil parentBeaconBlockRoot post-cancun"))
 	}
 
-	if !latestActive(api.eth.BlockChain().Config(), "cancun", params.Timestamp) {
+	if api.eth.BlockChain().Config().LatestFork(params.Timestamp) != forks.Cancun {
 		return engine.PayloadStatusV1{Status: engine.INVALID}, engine.UnsupportedFork.With(errors.New("newPayloadV3 must only be called for cancun payloads"))
 	}
 	return api.newPayload(params, versionedHashes, beaconRoot)
 }
 
-// latestActive returns true only if fork is the latest latestActive fork. It returns false otherwise.
-func latestActive(config *params.ChainConfig, fork string, time uint64) bool {
-	switch fork {
-	case "shanghai":
-		if !config.IsShanghai(config.LondonBlock, time) {
-			return false
-		}
-		if config.IsCancun(config.LondonBlock, time) {
-			return false
-		}
-	case "cancun":
-		if !config.IsCancun(config.LondonBlock, time) {
-			return false
-		}
-		if config.IsPrague(config.LondonBlock, time) {
-			return false
-		}
-	}
-	return true
-}
-
 func (api *ConsensusAPI) newPayload(params engine.ExecutableData, versionedHashes []common.Hash, beaconRoot *common.Hash) (engine.PayloadStatusV1, error) {
 	// The locking here is, strictly, not required. Without these locks, this can happen:
 	//

params/config.go

@@ -21,6 +21,7 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/params/forks"
 )
 
 // Genesis hashes to enforce below configs on.
@@ -750,6 +751,21 @@ func (c *ChainConfig) ElasticityMultiplier() uint64 {
 	return DefaultElasticityMultiplier
 }
 
+// LatestFork returns the latest time-based fork that would be active for the given time.
+func (c *ChainConfig) LatestFork(time uint64) forks.Fork {
+	// Assume last non-time-based fork has passed.
+	london := c.LondonBlock
+
+	switch {
+	case c.IsCancun(london, time):
+		return forks.Cancun
+	case c.IsShanghai(london, time):
+		return forks.Shanghai
+	default:
+		return forks.Paris
+	}
+}
+
 // isForkBlockIncompatible returns true if a fork scheduled at block s1 cannot be
 // rescheduled to block s2 because head is already past the fork.
 func isForkBlockIncompatible(s1, s2, head *big.Int) bool {

params/forks/forks.go

@@ -0,0 +1,42 @@
+// Copyright 2023 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 forks
+
+// Fork is a numerical identifier of specific network upgrades (forks).
+type Fork int
+
+const (
+	Frontier = iota
+	FrontierThawing
+	Homestead
+	DAO
+	TangerineWhistle
+	SpuriousDragon
+	Byzantium
+	Constantinople
+	Petersburg
+	Istanbul
+	MuirGlacier
+	Berlin
+	London
+	ArrowGlacier
+	GrayGlacier
+	Paris
+	Shanghai
+	Cancun
+	Prague
+)