Require non-zero delegation fee

contracts/staking/ERC20TokenStakingManager.sol

@@ -82,16 +82,21 @@ contract ERC20TokenStakingManager is
      * @param stakeAmount The amount to be staked.
      * @param nodeID The node ID of the validator being registered.
      * @param registrationExpiry The Unix timestamp after which the reigistration is no longer valid on the P-Chain.
+     * @param delegationFeeRate The fee charged to delegators by the validator.
      * @param blsPublicKey The BLS public key of the validator.
      */
     function initializeValidatorRegistration(
         uint256 stakeAmount,
         bytes32 nodeID,
         uint64 registrationExpiry,
+        uint256 delegationFeeRate,
         bytes memory blsPublicKey
     ) external returns (bytes32 validationID) {
         uint64 weight = _processStake(stakeAmount);
-        return _initializeValidatorRegistration(nodeID, weight, registrationExpiry, blsPublicKey);
+        validationID =
+            _initializeValidatorRegistration(nodeID, weight, registrationExpiry, blsPublicKey);
+        _setDelegationFeeRate(validationID, delegationFeeRate);
+        return validationID;
     }
 
     /**

contracts/staking/NativeTokenStakingManager.sol

@@ -46,15 +46,20 @@ contract NativeTokenStakingManager is
      * @notice Begins the validator registration process. Locks the provided native asset in the contract as the stake.
      * @param nodeID The node ID of the validator being registered.
      * @param registrationExpiry The Unix timestamp after which the reigistration is no longer valid on the P-Chain.
+     * @param delegationFeeRate The fee rate in basis points charged by this validator for delegations.
      * @param blsPublicKey The BLS public key of the validator.
      */
     function initializeValidatorRegistration(
         bytes32 nodeID,
         uint64 registrationExpiry,
+        uint256 delegationFeeRate,
         bytes memory blsPublicKey
-    ) external payable returns (bytes32) {
+    ) external payable returns (bytes32 validationID) {
         uint64 weight = _processStake(msg.value);
-        return _initializeValidatorRegistration(nodeID, weight, registrationExpiry, blsPublicKey);
+        validationID =
+            _initializeValidatorRegistration(nodeID, weight, registrationExpiry, blsPublicKey);
+        _setDelegationFeeRate(validationID, delegationFeeRate);
+        return validationID;
     }
 
     /**

contracts/staking/PoSValidatorManager.sol

@@ -26,6 +26,8 @@ abstract contract PoSValidatorManager is IPoSValidatorManager, ValidatorManager
         uint256 _maximumStakeAmount;
         /// @notice The minimum amount of time a validator must be staked for.
         uint64 _minimumStakeDuration;
+        /// @notice The minimum fee rate in basis points charged to the delegators by the validator.
+        uint256 _minimumDelegationFeeRate;
         /// @notice The reward calculator for this validator manager.
         IRewardCalculator _rewardCalculator;
         /// @notice Maps the validationID to a mapping of delegator address to delegator information.
@@ -38,6 +40,8 @@ abstract contract PoSValidatorManager is IPoSValidatorManager, ValidatorManager
             _pendingEndDelegatorMessages;
         /// @notice Maps the validationID to the uptime of the validator.
         mapping(bytes32 validationID => uint64) _validatorUptimes;
+        /// @notice Maps the validationID to the delegation fee rate.
+        mapping(bytes32 validationID => uint256) _validatorDelegationFeeRates;
     }
     // solhint-enable private-vars-leading-underscore
 
@@ -46,6 +50,9 @@ abstract contract PoSValidatorManager is IPoSValidatorManager, ValidatorManager
     bytes32 private constant _POS_VALIDATOR_MANAGER_STORAGE_LOCATION =
         0x4317713f7ecbdddd4bc99e95d903adedaa883b2e7c2551610bd13e2c7e473d00;
 
+    // The maximum delegation fee rate in basis points. This is 99.99%
+    uint256 public constant MAXIMUM_DELEGATION_FEE_RATE = 1e4 - 1;
+
     // solhint-disable ordering
     function _getPoSValidatorManagerStorage()
         private
@@ -68,6 +75,7 @@ abstract contract PoSValidatorManager is IPoSValidatorManager, ValidatorManager
             settings.minimumStakeAmount,
             settings.maximumStakeAmount,
             settings.minimumStakeDuration,
+            settings.minimumDelegationFeeRate,
             settings.rewardCalculator
         );
     }
@@ -77,13 +85,19 @@ abstract contract PoSValidatorManager is IPoSValidatorManager, ValidatorManager
         uint256 minimumStakeAmount,
         uint256 maximumStakeAmount,
         uint64 minimumStakeDuration,
+        uint256 minimumDelegationFeeRate,
         IRewardCalculator rewardCalculator
     ) internal onlyInitializing {
+        require(
+            minimumDelegationFeeRate > 0 && minimumDelegationFeeRate < MAXIMUM_DELEGATION_FEE_RATE,
+            "PoSValidatorManager: invalid minimum delegation fee rate"
+        );
         PoSValidatorManagerStorage storage s = _getPoSValidatorManagerStorage();
         s._minimumStakeAmount = minimumStakeAmount;
         s._maximumStakeAmount = maximumStakeAmount;
         s._minimumStakeDuration = minimumStakeDuration;
         s._rewardCalculator = rewardCalculator;
+        s._minimumDelegationFeeRate = minimumDelegationFeeRate;
     }
 
     function initializeEndValidation(
@@ -120,6 +134,16 @@ abstract contract PoSValidatorManager is IPoSValidatorManager, ValidatorManager
         _initializeEndValidation(validationID);
     }
 
+    function _setDelegationFeeRate(bytes32 validationID, uint256 feeRate) internal {
+        PoSValidatorManagerStorage storage $ = _getPoSValidatorManagerStorage();
+        require(
+            feeRate >= $._minimumDelegationFeeRate && feeRate <= MAXIMUM_DELEGATION_FEE_RATE,
+            "PoSValidatorManager: invalid delegation fee rate"
+        );
+        $._validatorDelegationFeeRates[validationID] = feeRate;
+        emit DelegationFeeRateSet(validationID, feeRate);
+    }
+
     function _processStake(uint256 stakeAmount) internal virtual returns (uint64) {
         PoSValidatorManagerStorage storage $ = _getPoSValidatorManagerStorage();
         // Lock the stake in the contract.

contracts/staking/ValidatorManager.sol

@@ -99,6 +99,7 @@ abstract contract ValidatorManager is
     /**
      * @notice Begins the validator registration process, and sets the initial weight for the validator.
      * @param nodeID The node ID of the validator being registered.
+     * @param weight The weight of the validator being registered.
      * @param registrationExpiry The Unix timestamp after which the reigistration is no longer valid on the P-Chain.
      * @param blsPublicKey The BLS public key of the validator.
      */

contracts/staking/interfaces/IERC20TokenStakingManager.sol

@@ -10,14 +10,17 @@ import {IPoSValidatorManager} from "./IPoSValidatorManager.sol";
 interface IERC20TokenStakingManager is IPoSValidatorManager {
     /**
      * @notice Begins the validator registration process. Locks the {stakeAmount} of the managers specified ERC20 token.
+     * @param stakeAmount The amount of the ERC20 token to stake.
      * @param nodeID The node ID of the validator being registered.
      * @param registrationExpiry The Unix timestamp after which the reigistration is no longer valid on the P-Chain.
+     * @param delegationFeeRate The fee rate in basis points charged by this validator for delegations.
      * @param blsPublicKey The BLS public key of the validator.
      */
     function initializeValidatorRegistration(
         uint256 stakeAmount,
         bytes32 nodeID,
         uint64 registrationExpiry,
+        uint256 delegationFeeRate,
         bytes memory blsPublicKey
     ) external returns (bytes32 validationID);
 

contracts/staking/interfaces/INativeTokenStakingManager.sol

@@ -12,11 +12,13 @@ interface INativeTokenStakingManager is IPoSValidatorManager {
      * @notice Begins the validator registration process. Locks the provided native asset in the contract as the stake.
      * @param nodeID The node ID of the validator being registered.
      * @param registrationExpiry The Unix timestamp after which the reigistration is no longer valid on the P-Chain.
+     * @param delegationFeeRate The fee rate in basis points charged by this validator for delegations.
      * @param blsPublicKey The BLS public key of the validator.
      */
     function initializeValidatorRegistration(
         bytes32 nodeID,
         uint64 registrationExpiry,
+        uint256 delegationFeeRate,
         bytes memory blsPublicKey
     ) external payable returns (bytes32 validationID);
 

contracts/staking/interfaces/IPoSValidatorManager.sol

@@ -21,6 +21,7 @@ struct PoSValidatorManagerSettings {
     uint256 minimumStakeAmount;
     uint256 maximumStakeAmount;
     uint64 minimumStakeDuration;
+    uint256 minimumDelegationFeeRate;
     IRewardCalculator rewardCalculator;
 }
 
@@ -41,6 +42,13 @@ interface IPoSValidatorManager is IValidatorManager {
      */
     event ValidationUptimeUpdated(bytes32 indexed validationID, uint64 uptime);
 
+    /**
+     * @notice Event emitted when a validator's delegation fee is set. This is only emitted at the start of a validation
+     * @param validationID The ID of the validation period
+     * @param delegationFeeRate Fee rate in basis points charged by this validator its delegators.
+     */
+    event DelegationFeeRateSet(bytes32 indexed validationID, uint256 delegationFeeRate);
+
     /**
      * @notice Event emitted when a delegator registration is initiated
      * @param validationID The ID of the validation period

contracts/staking/tests/ERC20TokenStakingManagerTests.t.sol

@@ -37,10 +37,12 @@ contract ERC20TokenStakingManagerTest is PoSValidatorManagerTest {
                 minimumStakeAmount: DEFAULT_MINIMUM_STAKE,
                 maximumStakeAmount: DEFAULT_MAXIMUM_STAKE,
                 minimumStakeDuration: DEFAULT_MINIMUM_STAKE_DURATION,
+                minimumDelegationFeeRate: DEFAULT_MINIMUM_DELEGATION_FEE_RATE,
                 rewardCalculator: IRewardCalculator(address(0))
             }),
             token
         );
+        delegationFeeRate = DEFAULT_MINIMUM_DELEGATION_FEE_RATE;
         validatorManager = app;
         posValidatorManager = app;
     }
@@ -52,7 +54,7 @@ contract ERC20TokenStakingManagerTest is PoSValidatorManagerTest {
         uint64 weight
     ) internal virtual override returns (bytes32) {
         return app.initializeValidatorRegistration(
-            app.weightToValue(weight), nodeID, registrationExpiry, signature
+            app.weightToValue(weight), nodeID, registrationExpiry, delegationFeeRate, signature
         );
     }
 

contracts/staking/tests/ExamplesRewardCalculatorTests.t.sol

@@ -13,7 +13,7 @@ contract ExampleRewardCalculatorTest is Test {
 
     uint256 public constant DEFAULT_STAKE_AMOUNT = 1e12;
     uint64 public constant DEFAULT_START_TIME = 1000;
-    uint64 public constant DEFAULT_END_TIME = 31537000; // a year + 1000 seonds
+    uint64 public constant DEFAULT_END_TIME = 31537000; // a year + 1000 seconds
     uint64 public constant DEFAULT_REWARD_BASIS_POINTS = 42;
 
     function setUp() public {

contracts/staking/tests/NativeTokenStakingManagerTests.t.sol

@@ -30,9 +30,11 @@ contract NativeTokenStakingManagerTest is PoSValidatorManagerTest {
                 minimumStakeAmount: DEFAULT_MINIMUM_STAKE,
                 maximumStakeAmount: DEFAULT_MAXIMUM_STAKE,
                 minimumStakeDuration: DEFAULT_MINIMUM_STAKE_DURATION,
+                minimumDelegationFeeRate: DEFAULT_MINIMUM_DELEGATION_FEE_RATE,
                 rewardCalculator: IRewardCalculator(address(0))
             })
         );
+        delegationFeeRate = DEFAULT_MINIMUM_DELEGATION_FEE_RATE;
         validatorManager = app;
         posValidatorManager = app;
     }
@@ -45,7 +47,7 @@ contract NativeTokenStakingManagerTest is PoSValidatorManagerTest {
         uint64 weight
     ) internal virtual override returns (bytes32) {
         return app.initializeValidatorRegistration{value: app.weightToValue(weight)}(
-            nodeID, registrationExpiry, signature
+            nodeID, registrationExpiry, delegationFeeRate, signature
         );
     }
 

contracts/staking/tests/PoSValidatorManagerTests.t.sol

@@ -22,6 +22,10 @@ abstract contract PoSValidatorManagerTest is ValidatorManagerTest {
     address public constant DEFAULT_DELEGATOR_ADDRESS =
         address(0x1234123412341234123412341234123412341234);
 
+    // This is the rate that will be passed into the child contract `initializeValidatorRegistration` calls
+    // It is set here to avoid having to pass irrelevant initializers to the parent contract.
+    uint256 public delegationFeeRate;
+
     PoSValidatorManager public posValidatorManager;
 
     event ValidationUptimeUpdated(bytes32 indexed validationID, uint64 uptime);

contracts/staking/tests/ValidatorManagerTests.t.sol

@@ -38,6 +38,7 @@ abstract contract ValidatorManagerTest is Test {
     uint64 public constant DEFAULT_EXPIRY = 1000;
     uint64 public constant DEFAULT_REGISTRATION_TIMESTAMP = 1000;
     uint64 public constant DEFAULT_COMPLETION_TIMESTAMP = 2000;
+    uint256 public constant DEFAULT_MINIMUM_DELEGATION_FEE_RATE = 100; // 1%
 
     ValidatorManager public validatorManager;
 

tests/utils/staking.go

@@ -131,10 +131,11 @@ func DeployAndInitializeERC20TokenStakingManager(
 				SubnetID:           subnet.SubnetID,
 				MaximumHourlyChurn: 0,
 			},
-			MinimumStakeAmount:   big.NewInt(0).SetUint64(1e6),
-			MaximumStakeAmount:   big.NewInt(0).SetUint64(10e6),
-			MinimumStakeDuration: uint64(24 * time.Hour),
-			RewardCalculator:     common.Address{},
+			MinimumStakeAmount:       big.NewInt(0).SetUint64(1e6),
+			MaximumStakeAmount:       big.NewInt(0).SetUint64(10e6),
+			MinimumStakeDuration:     uint64(24 * time.Hour),
+			MinimumDelegationFeeRate: big.NewInt(0).SetUint64(100),
+			RewardCalculator:         common.Address{},
 		},
 		erc20Address,
 	)
@@ -213,6 +214,7 @@ func InitializeNativeValidatorRegistration(
 		opts,
 		nodeID,
 		uint64(time.Now().Add(24*time.Hour).Unix()),
+		big.NewInt(0).SetUint64(100),
 		blsPublicKey[:],
 	)
 	Expect(err).Should(BeNil())
@@ -252,6 +254,7 @@ func InitializeERC20ValidatorRegistration(
 		stakeAmount,
 		nodeID,
 		uint64(time.Now().Add(24*time.Hour).Unix()),
+		big.NewInt(0).SetUint64(100),
 		blsPublicKey[:],
 	)
 	Expect(err).Should(BeNil())