Cap the validators a Native Staking Strategy can hold

contracts/contracts/strategies/NativeStaking/NativeStakingSSVStrategy.sol

@@ -74,13 +74,15 @@ contract NativeStakingSSVStrategy is
     /// @param _wethAddress Address of the Erc20 WETH Token contract
     /// @param _ssvToken Address of the Erc20 SSV Token contract
     /// @param _ssvNetwork Address of the SSV Network contract
+    /// @param _maxValidators Maximum number of validators that can be registered in the strategy
     /// @param _feeAccumulator Address of the fee accumulator receiving execution layer validator rewards
     /// @param _beaconChainDepositContract Address of the beacon chain deposit contract
     constructor(
         BaseStrategyConfig memory _baseConfig,
         address _wethAddress,
         address _ssvToken,
         address _ssvNetwork,
+        uint256 _maxValidators,
         address _feeAccumulator,
         address _beaconChainDepositContract
     )
@@ -89,7 +91,8 @@ contract NativeStakingSSVStrategy is
             _wethAddress,
             _baseConfig.vaultAddress,
             _beaconChainDepositContract,
-            _ssvNetwork
+            _ssvNetwork,
+            _maxValidators
         )
     {
         SSV_TOKEN_ADDRESS = _ssvToken;

contracts/contracts/strategies/NativeStaking/ValidatorAccountant.sol

@@ -50,17 +50,20 @@ abstract contract ValidatorAccountant is ValidatorRegistrator {
     /// @param _vaultAddress Address of the Vault
     /// @param _beaconChainDepositContract Address of the beacon chain deposit contract
     /// @param _ssvNetwork Address of the SSV Network contract
+    /// @param _maxValidators Maximum number of validators that can be registered in the strategy
     constructor(
         address _wethAddress,
         address _vaultAddress,
         address _beaconChainDepositContract,
-        address _ssvNetwork
+        address _ssvNetwork,
+        uint256 _maxValidators
     )
         ValidatorRegistrator(
             _wethAddress,
             _vaultAddress,
             _beaconChainDepositContract,
-            _ssvNetwork
+            _ssvNetwork,
+            _maxValidators
         )
     {}
 

contracts/contracts/strategies/NativeStaking/ValidatorRegistrator.sol

@@ -28,6 +28,8 @@ abstract contract ValidatorRegistrator is Governable, Pausable {
     address public immutable SSV_NETWORK_ADDRESS;
     /// @notice Address of the OETH Vault proxy contract
     address public immutable VAULT_ADDRESS;
+    /// @notice Maximum number of validators that can be registered in this strategy
+    uint256 public immutable MAX_VALIDATORS;
 
     /// @notice Address of the registrator - allowed to register, exit and remove validators
     address public validatorRegistrator;
@@ -109,16 +111,19 @@ abstract contract ValidatorRegistrator is Governable, Pausable {
     /// @param _vaultAddress Address of the Vault
     /// @param _beaconChainDepositContract Address of the beacon chain deposit contract
     /// @param _ssvNetwork Address of the SSV Network contract
+    /// @param _maxValidators Maximum number of validators that can be registered in the strategy
     constructor(
         address _wethAddress,
         address _vaultAddress,
         address _beaconChainDepositContract,
-        address _ssvNetwork
+        address _ssvNetwork,
+        uint256 _maxValidators
     ) {
         WETH_TOKEN_ADDRESS = _wethAddress;
         BEACON_CHAIN_DEPOSIT_CONTRACT = _beaconChainDepositContract;
         SSV_NETWORK_ADDRESS = _ssvNetwork;
         VAULT_ADDRESS = _vaultAddress;
+        MAX_VALIDATORS = _maxValidators;
     }
 
     /// @notice Set the address of the registrator which can register, exit and remove validators
@@ -163,6 +168,10 @@ abstract contract ValidatorRegistrator is Governable, Pausable {
             requiredETH <= IWETH9(WETH_TOKEN_ADDRESS).balanceOf(address(this)),
             "insufficient WETH"
         );
+        require(
+            activeDepositedValidators + validators.length <= MAX_VALIDATORS,
+            "Max validators reached"
+        );
 
         require(
             stakeETHTally + requiredETH <= stakeETHThreshold,

contracts/deploy/deployActions.js

@@ -854,6 +854,7 @@ const upgradeNativeStakingSSVStrategy = async () => {
       assetAddresses.WETH, // wethAddress
       assetAddresses.SSV, // ssvToken
       assetAddresses.SSVNetwork, // ssvNetwork
+      600, // maxValidators
       cFeeAccumulatorProxy.address, // feeAccumulator
       assetAddresses.beaconChainDepositContract, // depositContractMock
     ]
@@ -900,6 +901,7 @@ const deployNativeStakingSSVStrategy = async () => {
       assetAddresses.WETH, // wethAddress
       assetAddresses.SSV, // ssvToken
       assetAddresses.SSVNetwork, // ssvNetwork
+      600, // maxValidators
       dFeeAccumulatorProxy.address, // feeAccumulator
       assetAddresses.beaconChainDepositContract, // depositContractMock
     ]

contracts/deploy/holesky/012_upgrade_strategy.js

@@ -0,0 +1,18 @@
+const { upgradeNativeStakingSSVStrategy } = require("../deployActions");
+
+const mainExport = async () => {
+  console.log("Running 012 deployment on Holesky...");
+
+  console.log("Upgrading native staking strategy");
+  await upgradeNativeStakingSSVStrategy();
+
+  console.log("Running 012 deployment done");
+  return true;
+};
+
+mainExport.id = "012_upgrade_strategy";
+mainExport.tags = [];
+mainExport.dependencies = [];
+mainExport.skip = () => false;
+
+module.exports = mainExport;

contracts/deploy/mainnet/097_native_ssv_staking.js

@@ -54,6 +54,7 @@ module.exports = deploymentWithGovernanceProposal(
         addresses.mainnet.WETH, // wethAddress
         addresses.mainnet.SSV, // ssvToken
         addresses.mainnet.SSVNetwork, // ssvNetwork
+        600, // maxValidators
         dFeeAccumulatorProxy.address, // feeAccumulator
         addresses.mainnet.beaconChainDepositContract, // beacon chain deposit contract
       ]