validator set precompile

consensus/polybft/contractsapi/init.go

@@ -66,13 +66,14 @@ var (
 
 	// test smart contracts
 	//go:embed test-contracts/*
-	testContracts          embed.FS
-	TestWriteBlockMetadata *contracts.Artifact
-	RootERC20              *contracts.Artifact
-	TestSimple             *contracts.Artifact
-	TestRewardToken        *contracts.Artifact
-	Wrapper                *contracts.Artifact
-	NumberPersister        *contracts.Artifact
+	testContracts              embed.FS
+	TestWriteBlockMetadata     *contracts.Artifact
+	RootERC20                  *contracts.Artifact
+	TestSimple                 *contracts.Artifact
+	TestRewardToken            *contracts.Artifact
+	Wrapper                    *contracts.Artifact
+	NumberPersister            *contracts.Artifact
+	TestValidatorSetPrecompile *contracts.Artifact
 
 	contractArtifacts map[string]*contracts.Artifact
 )
@@ -270,6 +271,11 @@ func init() {
 		log.Fatal(err)
 	}
 
+	TestValidatorSetPrecompile, err = contracts.DecodeArtifact(readTestContractContent("TestValidatorSetPrecompile.json"))
+	if err != nil {
+		log.Fatal(err)
+	}
+
 	StakeManager, err = contracts.DecodeArtifact([]byte(StakeManagerArtifact))
 	if err != nil {
 		log.Fatal(err)
@@ -381,6 +387,7 @@ func init() {
 		"RootERC20":                       RootERC20,
 		"TestSimple":                      TestSimple,
 		"TestRewardToken":                 TestRewardToken,
+		"TestValidatorSetPrecompile":      TestValidatorSetPrecompile,
 	}
 }
 

consensus/polybft/contractsapi/test-contracts/TestValidatorSetPrecompile.json

@@ -0,0 +1,66 @@
+{
+    "_format": "hh-sol-artifact-1",
+    "contractName": "TestValidatorSetPrecompile",
+    "sourceName": "consensus/polybft/contractsapi/test-contracts/TestValidatorSetContract.sol",
+    "abi": [
+        {
+           "inputs":[
+
+           ],
+           "name":"VALIDATOR_SET_PRECOMPILE",
+           "outputs":[
+              {
+                 "internalType":"address",
+                 "name":"",
+                 "type":"address"
+              }
+           ],
+           "stateMutability":"view",
+           "type":"function"
+        },
+        {
+           "inputs":[
+
+           ],
+           "name":"VALIDATOR_SET_PRECOMPILE_GAS",
+           "outputs":[
+              {
+                 "internalType":"uint256",
+                 "name":"",
+                 "type":"uint256"
+              }
+           ],
+           "stateMutability":"view",
+           "type":"function"
+        },
+        {
+           "inputs":[
+
+           ],
+           "name":"hasQuorum",
+           "outputs":[
+              {
+                 "internalType":"bool",
+                 "name":"",
+                 "type":"bool"
+              }
+           ],
+           "stateMutability":"view",
+           "type":"function"
+        },
+        {
+           "inputs":[
+
+           ],
+           "name":"inc",
+           "outputs":[
+
+           ],
+           "stateMutability":"nonpayable",
+           "type":"function"
+        }
+     ],
+    "bytecode": "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",
+    "linkReferences": {},
+    "deployedLinkReferences": {}
+}    

consensus/polybft/contractsapi/test-contracts/TestValidatorSetPrecompile.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: MIT
+// TestValidatorSetPrecompile.sol
+// Contract which testst ValidatorSet precompile
+pragma solidity ^0.8.0;
+
+contract TestValidatorSetPrecompile {
+    address constant VALIDATOR_SET_PRECOMPILE = 0x0000000000000000000000000000000000002040;
+    uint256 constant VALIDATOR_SET_PRECOMPILE_GAS = 240000;
+
+    mapping(address => bool) voteMap;
+    address[] votes;
+
+    modifier onlyValidator() {
+        (bool callSuccess, bytes memory returnData) = VALIDATOR_SET_PRECOMPILE.staticcall{
+            gas: VALIDATOR_SET_PRECOMPILE_GAS
+        }(abi.encode(msg.sender));
+        require(callSuccess && abi.decode(returnData, (bool)), "validator");
+        _;
+    }
+
+    function inc() public onlyValidator {
+        if (!voteMap[msg.sender]) {
+            votes.push(msg.sender);
+            voteMap[msg.sender] = true;
+        }
+    }
+
+    function hasQuorum() public view returns (bool) {
+        (bool callSuccess, bytes memory returnData) = VALIDATOR_SET_PRECOMPILE.staticcall{
+            gas: VALIDATOR_SET_PRECOMPILE_GAS
+        }(abi.encode(votes));
+        return callSuccess && abi.decode(returnData, (bool));
+    }
+}

consensus/polybft/polybft.go

@@ -471,6 +471,9 @@ func (p *Polybft) Initialize() error {
 		executor:   p.config.Executor,
 	}
 
+	// enable validatorset precompile
+	p.config.Executor.SetValidatorSetBackend(p)
+
 	// create bridge and consensus topics
 	if err = p.createTopics(); err != nil {
 		return fmt.Errorf("cannot create topics: %w", err)
@@ -754,6 +757,10 @@ func (p *Polybft) GetValidators(blockNumber uint64, parents []*types.Header) (va
 	return p.validatorsCache.GetSnapshot(blockNumber, parents, nil)
 }
 
+func (p *Polybft) GetValidatorsForBlock(blockNumber uint64) (validator.AccountSet, error) {
+	return p.validatorsCache.GetSnapshot(blockNumber, nil, nil)
+}
+
 func (p *Polybft) GetValidatorsWithTx(blockNumber uint64, parents []*types.Header,
 	dbTx *bolt.Tx) (validator.AccountSet, error) {
 	return p.validatorsCache.GetSnapshot(blockNumber, parents, dbTx)

consensus/polybft/validators_snapshot.go

@@ -182,15 +182,13 @@ func (v *validatorsSnapshotCache) computeSnapshot(
 
 	v.logger.Trace("Compute snapshot started...", "BlockNumber", nextEpochEndBlockNumber)
 
-	if len(parents) > 0 {
-		for i := len(parents) - 1; i >= 0; i-- {
-			parentHeader := parents[i]
-			if parentHeader.Number == nextEpochEndBlockNumber {
-				v.logger.Trace("Compute snapshot. Found header in parents", "Header", parentHeader.Number)
-				header = parentHeader
-
-				break
-			}
+	for i := len(parents) - 1; i >= 0; i-- {
+		parentHeader := parents[i]
+		if parentHeader.Number == nextEpochEndBlockNumber {
+			v.logger.Trace("Compute snapshot. Found header in parents", "Header", parentHeader.Number)
+			header = parentHeader
+
+			break
 		}
 	}
 

contracts/system_addresses.go

@@ -95,8 +95,10 @@ var (
 
 	// NativeTransferPrecompile is an address of native transfer precompile
 	NativeTransferPrecompile = types.StringToAddress("0x2020")
-	// BLSAggSigsVerificationPrecompile is an address of BLS aggregated signatures verificatin precompile
+	// BLSAggSigsVerificationPrecompile is an address of BLS aggregated signatures verification precompile
 	BLSAggSigsVerificationPrecompile = types.StringToAddress("0x2030")
+	// ValidatorSetPrecompile is an address of precompile which provides some validatorSet functionalities
+	ValidatorSetPrecompile = types.StringToAddress("0x2040")
 	// ConsolePrecompile is and address of Hardhat console precompile
 	ConsolePrecompile = types.StringToAddress("0x000000000000000000636F6e736F6c652e6c6f67")
 	// AllowListContractsAddr is the address of the contract deployer allow list

e2e-polybft/e2e/consensus_test.go

@@ -823,3 +823,119 @@ func TestE2E_Deploy_Nested_Contract(t *testing.T) {
 
 	require.Equal(t, numberToPersist, parsedResponse)
 }
+
+func TestE2E_TestValidatorSetPrecompile(t *testing.T) {
+	var (
+		premineBalance = ethgo.Ether(2e6) // 2M native tokens (so that we have enough balance to fund new validator)
+		stakeAmount    = ethgo.Ether(500)
+	)
+
+	admin, err := wallet.GenerateKey()
+	require.NoError(t, err)
+
+	dummyKey, err := wallet.GenerateKey()
+	require.NoError(t, err)
+
+	// start cluster with 'validatorSize' validators
+	cluster := framework.NewTestCluster(t, 4,
+		framework.WithBladeAdmin(admin.Address().String()),
+		framework.WithSecretsCallback(func(addresses []types.Address, config *framework.TestClusterConfig) {
+			for _, a := range addresses {
+				config.Premine = append(config.Premine, fmt.Sprintf("%s:%s", a, premineBalance))
+				config.StakeAmounts = append(config.StakeAmounts, stakeAmount)
+			}
+
+			config.Premine = append(config.Premine, fmt.Sprintf("%s:%s", dummyKey.Address(), premineBalance))
+		}),
+	)
+
+	defer cluster.Stop()
+
+	cluster.WaitForReady(t)
+
+	validatorKeys := make([]*wallet.Key, len(cluster.Servers))
+
+	for i, s := range cluster.Servers {
+		voterAcc, err := validatorHelper.GetAccountFromDir(s.DataDir())
+		require.NoError(t, err)
+
+		validatorKeys[i] = voterAcc.Ecdsa
+	}
+
+	txRelayer, err := txrelayer.NewTxRelayer(txrelayer.WithClient(cluster.Servers[0].JSONRPC()))
+	require.NoError(t, err)
+
+	// deploy contract
+	receipt, err := txRelayer.SendTransaction(
+		&ethgo.Transaction{
+			To:    nil,
+			Input: contractsapi.TestValidatorSetPrecompile.Bytecode,
+		},
+		admin)
+	require.NoError(t, err)
+
+	validatorSetPrecompileTestAddr := receipt.ContractAddress
+
+	hasQuorum := func() bool {
+		t.Helper()
+
+		hasQuorumFn := contractsapi.TestValidatorSetPrecompile.Abi.GetMethod("hasQuorum")
+
+		hasQuorumFnBytes, err := hasQuorumFn.Encode([]interface{}{})
+		require.NoError(t, err)
+
+		response, err := txRelayer.Call(ethgo.ZeroAddress, validatorSetPrecompileTestAddr, hasQuorumFnBytes)
+		require.NoError(t, err)
+
+		return response == "0x0000000000000000000000000000000000000000000000000000000000000001"
+	}
+
+	sendIncTx := func(validatorID int) {
+		t.Helper()
+
+		isValidator := validatorID >= 0 && validatorID < len(validatorKeys)
+		incFn := contractsapi.TestValidatorSetPrecompile.Abi.GetMethod("inc")
+
+		incFnBytes, err := incFn.Encode([]interface{}{})
+		require.NoError(t, err)
+
+		var key *wallet.Key
+		if isValidator {
+			key = validatorKeys[validatorID]
+		} else {
+			key = dummyKey
+		}
+
+		txn := &ethgo.Transaction{
+			From:  key.Address(),
+			To:    &validatorSetPrecompileTestAddr,
+			Input: incFnBytes,
+		}
+
+		receipt, err = txRelayer.SendTransaction(txn, key)
+
+		if isValidator {
+			require.NoError(t, err)
+			require.Equal(t, uint64(types.ReceiptSuccess), receipt.Status)
+		} else {
+			require.ErrorContains(t, err, "unable to apply transaction even for the highest gas limit")
+		}
+	}
+
+	require.False(t, hasQuorum())
+
+	sendIncTx(0)
+	require.False(t, hasQuorum())
+
+	sendIncTx(1)
+	require.False(t, hasQuorum())
+
+	sendIncTx(1)
+	require.False(t, hasQuorum())
+
+	sendIncTx(-1) // non validator
+	require.False(t, hasQuorum())
+
+	sendIncTx(3)
+	require.True(t, hasQuorum())
+}

helper/predeployment/predeployment.go

@@ -68,7 +68,7 @@ func getPredeployAccount(address types.Address, input []byte,
 	config := chain.AllForksEnabled.At(0)
 
 	// Create a transition
-	transition := state.NewTransition(hclog.NewNullLogger(), config, snapshot, radix)
+	transition := state.NewTransition(hclog.NewNullLogger(), config, snapshot, radix, nil)
 	transition.ContextPtr().ChainID = chainID
 
 	// Run the transition through the EVM

state/executor.go

@@ -45,6 +45,10 @@ type Executor struct {
 
 	PostHook        func(txn *Transition)
 	GenesisPostHook func(*Transition) error
+
+	// this value should be set if we want to enable validator set precompile
+	// note that this precompile WONT be enabled for WriteGenesis
+	validatorSetBackend precompiled.ValidatorSetPrecompileBackend
 }
 
 // NewExecutor creates a new executor
@@ -81,7 +85,7 @@ func (e *Executor) WriteGenesis(
 		ChainID: e.config.ChainID,
 	}
 
-	transition := NewTransition(e.logger, config, snap, txn)
+	transition := NewTransition(e.logger, config, snap, txn, nil)
 	transition.ctx = env
 
 	for addr, account := range alloc {
@@ -199,7 +203,7 @@ func (e *Executor) BeginTxn(
 		BurnContract: burnContract,
 	}
 
-	t := NewTransition(e.logger, forkConfig, snap, newTxn)
+	t := NewTransition(e.logger, forkConfig, snap, newTxn, e.validatorSetBackend)
 	t.PostHook = e.PostHook
 	t.getHash = e.GetHash(header)
 	t.ctx = txCtx
@@ -235,6 +239,10 @@ func (e *Executor) BeginTxn(
 	return t, nil
 }
 
+func (e *Executor) SetValidatorSetBackend(validatorSetBackend precompiled.ValidatorSetPrecompileBackend) {
+	e.validatorSetBackend = validatorSetBackend
+}
+
 type Transition struct {
 	logger hclog.Logger
 
@@ -272,14 +280,15 @@ type Transition struct {
 	accessList *runtime.AccessList
 }
 
-func NewTransition(logger hclog.Logger, config chain.ForksInTime, snap Snapshot, radix *Txn) *Transition {
+func NewTransition(logger hclog.Logger, config chain.ForksInTime,
+	snap Snapshot, radix *Txn, validatorSetBackend precompiled.ValidatorSetPrecompileBackend) *Transition {
 	return &Transition{
 		logger:      logger,
 		config:      config,
 		state:       radix,
 		snap:        snap,
 		evm:         evm.NewEVM(),
-		precompiles: precompiled.NewPrecompiled(),
+		precompiles: precompiled.NewPrecompiled(validatorSetBackend),
 		journal:     &runtime.Journal{},
 		accessList:  runtime.NewAccessList(),
 	}