params,internal: add eth_config

Author: lightclient

internal/ethapi/api.go

@@ -1135,6 +1135,34 @@ func (api *BlockChainAPI) CreateAccessList(ctx context.Context, args Transaction
 	return result, nil
 }
 
+type config struct {
+	ActivationTime  uint64                    `json:"activationTime"`
+	BlobSchedule    *params.BlobConfig        `json:"blobSchedule"`
+	ChainId         *hexutil.Big              `json:"chainId"`
+	Precompiles     map[common.Address]string `json:"precompiles"`
+	SystemContracts map[string]common.Address `json:"systemContracts"`
+}
+
+// Config implements the EIP-7910 eth_config method.
+func (api *BlockChainAPI) Config(ctx context.Context) config {
+	var (
+		c           = api.b.ChainConfig()
+		h           = api.b.CurrentBlock()
+		rules       = c.Rules(h.Number, true, h.Time)
+		precompiles = make(map[common.Address]string)
+	)
+	for addr, c := range vm.ActivePrecompiledContracts(rules) {
+		precompiles[addr] = c.Name()
+	}
+	return config{
+		ActivationTime:  c.NextForkTime(h.Time),
+		BlobSchedule:    c.BlobConfig(c.LatestFork(h.Time)),
+		ChainId:         (*hexutil.Big)(c.ChainID),
+		Precompiles:     precompiles,
+		SystemContracts: c.ActiveSystemContracts(h.Time),
+	}
+}
+
 // AccessList creates an access list for the given transaction.
 // If the accesslist creation fails an error is returned.
 // If the transaction itself fails, an vmErr is returned.

internal/jsre/deps/web3.js

@@ -5490,6 +5490,10 @@ var properties = function () {
         new Property({
             name: 'protocolVersion',
             getter: 'eth_protocolVersion'
+        }),
+        new Property({
+          name: 'config',
+          getter: 'eth_config'
         })
     ];
 };

params/config.go

@@ -985,6 +985,65 @@ func (c *ChainConfig) LatestFork(time uint64) forks.Fork {
 	}
 }
 
+// NextFork returns the next fork to activate or nil if the last defined fork is
+// active.
+func (c *ChainConfig) NextForkTime(time uint64) uint64 {
+	// Assume last non-time-based fork has passed.
+	london := c.LondonBlock
+	next := newUint64(0)
+
+	switch {
+	case c.IsOsaka(london, time):
+		next = c.OsakaTime
+	case c.IsPrague(london, time):
+		next = c.OsakaTime
+	case c.IsCancun(london, time):
+		next = c.PragueTime
+	case c.IsShanghai(london, time):
+		next = c.CancunTime
+	default:
+		next = c.ShanghaiTime
+	}
+	if next == nil {
+		return 0
+	}
+	return *next
+}
+
+// BlobConfig returns the blob config associated with the provided fork.
+func (c *ChainConfig) BlobConfig(fork forks.Fork) *BlobConfig {
+	switch fork {
+	case forks.Osaka:
+		return DefaultOsakaBlobConfig
+	case forks.Prague:
+		return DefaultPragueBlobConfig
+	case forks.Cancun:
+		return DefaultCancunBlobConfig
+	default:
+		return nil
+	}
+}
+
+// ActiveSystemContracts returns the currently active system contracts at the
+// given timestamp.
+func (c *ChainConfig) ActiveSystemContracts(time uint64) map[string]common.Address {
+	fork := c.LatestFork(time)
+	active := make(map[string]common.Address)
+	if fork >= forks.Osaka {
+		// no new system contracts
+	}
+	if fork >= forks.Prague {
+		active["CONSOLIDATION_REQUEST_PREDEPLOY_ADDRESS"] = ConsolidationQueueAddress
+		active["DEPOSIT_CONTRACT_ADDRESS"] = c.DepositContractAddress
+		active["HISTORY_STORAGE_ADDRESS"] = HistoryStorageAddress
+		active["WITHDRAWAL_REQUEST_PREDEPLOY_ADDRESS"] = WithdrawalQueueAddress
+	}
+	if fork >= forks.Cancun {
+		active["BEACON_ROOTS_ADDRESS"] = BeaconRootsAddress
+	}
+	return active
+}
+
 // Timestamp returns the timestamp associated with the fork or returns nil if
 // the fork isn't defined or isn't a time-based fork.
 func (c *ChainConfig) Timestamp(fork forks.Fork) *uint64 {