implements L1SLOAD contract

core/vm/contracts_rollup.go

@@ -4,27 +4,23 @@
 package vm
 
 import (
+	"context"
 	"errors"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 )
 
-type RollupPrecompiledContractsOverrides struct {
-	l1SLoadGetLatestL1Block func() *big.Int
-}
-
-func GenerateRollupPrecompiledContractsOverrides(evm *EVM) RollupPrecompiledContractsOverrides {
-	return RollupPrecompiledContractsOverrides{
-		l1SLoadGetLatestL1Block: getLatestL1BlockNumber(evm),
-	}
-}
-
 var rollupL1SloadAddress = common.BytesToAddress([]byte{0x10, 0x01})
 
 var PrecompiledContractsRollupR0 = PrecompiledContracts{
-	rollupL1SloadAddress: &l1SLoad{},
+	rollupL1SloadAddress: &L1SLoad{},
+}
+
+type RollupPrecompileActivationConfig struct {
+	L1SLoad
 }
 
 func activeRollupPrecompiledContracts(rules params.Rules) PrecompiledContracts {
@@ -36,40 +32,85 @@ func activeRollupPrecompiledContracts(rules params.Rules) PrecompiledContracts {
 	}
 }
 
-func (evm *EVM) activateRollupPrecompiledContracts() {
-	activeRollupPrecompiles := activeRollupPrecompiledContracts(evm.chainRules)
-	for k, v := range activeRollupPrecompiles {
-		evm.precompiles[k] = v
-	}
-
+func (pc *PrecompiledContracts) ActivateRollupPrecompiledContracts(config RollupPrecompileActivationConfig) {
 	// NOTE: if L1SLoad was not activated via chain rules this is no-op
-	evm.precompiles.activateL1SLoad(evm.Config.L1RpcClient, evm.rollupPrecompileOverrides.l1SLoadGetLatestL1Block)
+	pc.activateL1SLoad(config.L1RpcClient, config.GetLatestL1BlockNumber)
+}
+
+func (evm *EVM) activateRollupPrecompiledContracts() {
+	evm.precompiles.ActivateRollupPrecompiledContracts(RollupPrecompileActivationConfig{
+		L1SLoad{L1RpcClient: evm.Config.L1RpcClient, GetLatestL1BlockNumber: evm.rollupPrecompileOverrides.l1SLoadGetLatestL1Block},
+	})
 }
 
-type l1SLoad struct {
-	l1RpcClient            L1Client
-	getLatestL1BlockNumber func() *big.Int
+//INPUT SPECS:
+//Byte range          Name              Description
+//------------------------------------------------------------
+//[0: 19] (20 bytes)	address	          The contract address
+//[20: 51] (32 bytes)	key1	            The storage key
+//...	...	...
+//[k*32-12: k*32+19]  (32 bytes)	key_k	The storage key
+
+type L1SLoad struct {
+	L1RpcClient            L1RpcClient
+	GetLatestL1BlockNumber func() *big.Int
 }
 
-func (c *l1SLoad) RequiredGas(input []byte) uint64 { return 0 }
+func (c *L1SLoad) RequiredGas(input []byte) uint64 {
+	storageSlotsToLoad := len(input[common.AddressLength-1:]) / common.HashLength
+	storageSlotsToLoad = min(storageSlotsToLoad, params.L1SLoadMaxNumStorageSlots)
 
-func (c *l1SLoad) Run(input []byte) ([]byte, error) {
+	return params.L1SLoadBaseGas + uint64(storageSlotsToLoad)*params.L1SLoadPerLoadGas
+}
+
+func (c *L1SLoad) Run(input []byte) ([]byte, error) {
 	if !c.isL1SLoadActive() {
-		return nil, errors.New("L1SLoad precompile not active")
+		log.Error("L1SLOAD called, but not activated", "client", c.L1RpcClient, "and latest block number function", c.GetLatestL1BlockNumber)
+		return nil, errors.New("L1SLOAD precompile not active")
+	}
+
+	if len(input) < common.AddressLength+common.HashLength {
+		return nil, errors.New("L1SLOAD input too short")
+	}
+
+	countOfStorageKeysToRead := (len(input) - common.AddressLength) / common.HashLength
+	thereIsAtLeast1StorageKeyToRead := countOfStorageKeysToRead > 0
+	allStorageKeysAreExactly32Bytes := countOfStorageKeysToRead*common.HashLength == len(input)-common.AddressLength
+
+	if inputIsValid := thereIsAtLeast1StorageKeyToRead && allStorageKeysAreExactly32Bytes; !inputIsValid {
+		return nil, errors.New("L1SLOAD input is malformed")
+	}
+
+	contractAddress := common.BytesToAddress(input[:common.AddressLength])
+	input = input[common.AddressLength-1:]
+	contractStorageKeys := make([]common.Hash, countOfStorageKeysToRead)
+	for k := 0; k < countOfStorageKeysToRead; k++ {
+		contractStorageKeys[k] = common.BytesToHash(input[k*common.HashLength : (k+1)*common.HashLength])
 	}
 
-	return nil, nil
+	// TODO:
+	// 1. Batch multiple storage slots
+	// 2. What about timeout strategy here?
+	res, err := c.L1RpcClient.StorageAt(context.Background(), contractAddress, contractStorageKeys[0], c.GetLatestL1BlockNumber())
+	if err != nil {
+		return nil, err
+	}
+
+	return res, nil
 }
 
-func (c *l1SLoad) isL1SLoadActive() bool {
-	return c.getLatestL1BlockNumber != nil && c.l1RpcClient != nil
+func (c *L1SLoad) isL1SLoadActive() bool {
+	return c.GetLatestL1BlockNumber != nil && c.L1RpcClient != nil
 }
 
-func (pc *PrecompiledContracts) activateL1SLoad(l1RpcClient L1Client, getLatestL1BlockNumber func() *big.Int) {
-	if (*pc)[rollupL1SloadAddress] != nil {
-		(*pc)[rollupL1SloadAddress] = &l1SLoad{
-			l1RpcClient:            l1RpcClient,
-			getLatestL1BlockNumber: getLatestL1BlockNumber,
+func (pc PrecompiledContracts) activateL1SLoad(l1RpcClient L1RpcClient, getLatestL1BlockNumber func() *big.Int) {
+	rulesSayContractShouldBeActive := pc[rollupL1SloadAddress] != nil
+	paramsNotNil := l1RpcClient != nil && getLatestL1BlockNumber != nil
+
+	if shouldActivateL1SLoad := rulesSayContractShouldBeActive && paramsNotNil; shouldActivateL1SLoad {
+		pc[rollupL1SloadAddress] = &L1SLoad{
+			L1RpcClient:            l1RpcClient,
+			GetLatestL1BlockNumber: getLatestL1BlockNumber,
 		}
 	}
 }

core/vm/contracts_rollup_test.go

@@ -0,0 +1,32 @@
+package vm
+
+import (
+	"context"
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type MockL1RPCClient struct{}
+
+func (m MockL1RPCClient) StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
+	return common.Hex2Bytes("abab"), nil
+}
+
+func TestPrecompiledL1SLOAD(t *testing.T) {
+	mockL1RPCClient := MockL1RPCClient{}
+
+	allPrecompiles[rollupL1SloadAddress] = &L1SLoad{}
+	allPrecompiles.activateL1SLoad(mockL1RPCClient, func() *big.Int { return big1 })
+
+	l1SLoadTestcase := precompiledTest{
+		Name:        "L1SLOAD",
+		Input:       "C02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc22d2c7bb6fc06067df8b0223aec460d1ebb51febb9012bc2554141a4dca08e864",
+		Expected:    "abab",
+		Gas:         4000,
+		NoBenchmark: true,
+	}
+
+	testPrecompiled(rollupL1SloadAddress.Hex(), l1SLoadTestcase, t)
+}

core/vm/contracts_test.go

@@ -45,7 +45,7 @@ type precompiledFailureTest struct {
 
 // allPrecompiles does not map to the actual set of precompiles, as it also contains
 // repriced versions of precompiles at certain slots
-var allPrecompiles = map[common.Address]PrecompiledContract{
+var allPrecompiles = PrecompiledContracts{
 	common.BytesToAddress([]byte{1}):    &ecrecover{},
 	common.BytesToAddress([]byte{2}):    &sha256hash{},
 	common.BytesToAddress([]byte{3}):    &ripemd160hash{},
@@ -181,7 +181,7 @@ func benchmarkPrecompiled(addr string, test precompiledTest, bench *testing.B) {
 		// Keep it as uint64, multiply 100 to get two digit float later
 		mgasps := (100 * 1000 * gasUsed) / elapsed
 		bench.ReportMetric(float64(mgasps)/100, "mgas/s")
-		//Check if it is correct
+		// Check if it is correct
 		if err != nil {
 			bench.Error(err)
 			return

params/protocol_params_rollup.go

@@ -0,0 +1,7 @@
+package params
+
+const (
+	L1SLoadBaseGas            uint64 = 2000 // Base price for L1Sload
+	L1SLoadPerLoadGas         uint64 = 2000 // Per-load price for loading one storage slot
+	L1SLoadMaxNumStorageSlots        = 5    // Max number of storage slots requested in L1Sload precompile
+)