add rate limit to calling manually fix accounting

contracts/contracts/strategies/NativeStaking/ValidatorAccountant.sol

@@ -10,6 +10,8 @@ import { IWETH9 } from "../../interfaces/IWETH9.sol";
 /// Full withdrawals are from exited validators.
 /// @author Origin Protocol Inc
 abstract contract ValidatorAccountant is ValidatorRegistrator {
+    /// @notice The minimum amount of blocks that need to pass between two calls to manuallyFixAccounting
+    uint256 public constant MIN_FIX_ACCOUNTING_CADENCE = 7200; // 1 day
     /// @notice The maximum amount of ETH that can be staked by a validator
     /// @dev this can change in the future with EIP-7251, Increase the MAX_EFFECTIVE_BALANCE
     uint256 public constant MAX_STAKE = 32 ether;
@@ -21,8 +23,10 @@ abstract contract ValidatorAccountant is ValidatorRegistrator {
     uint256 public fuseIntervalStart;
     /// @notice end of fuse interval
     uint256 public fuseIntervalEnd;
+    /// @notice last block number manuallyFixAccounting has been called
+    uint256 public lastFixAccountingBlockNumber;
 
-    uint256[50] private __gap;
+    uint256[49] private __gap;
 
     event FuseIntervalUpdated(uint256 start, uint256 end);
     event AccountingFullyWithdrawnValidator(
@@ -186,6 +190,11 @@ abstract contract ValidatorAccountant is ValidatorRegistrator {
         int256 _validatorsDelta,
         int256 _consensusRewardsDelta
     ) external onlyStrategist whenPaused {
+        require(
+            lastFixAccountingBlockNumber + MIN_FIX_ACCOUNTING_CADENCE <
+                block.number,
+            "manuallyFixAccounting called too soon"
+        );
         require(
             _validatorsDelta >= -3 &&
                 _validatorsDelta <= 3 &&
@@ -210,6 +219,8 @@ abstract contract ValidatorAccountant is ValidatorRegistrator {
             int256(consensusRewards) + _consensusRewardsDelta
         );
 
+        lastFixAccountingBlockNumber = block.number;
+
         // rerun the accounting to see if it has now been fixed.
         // Do not pause the accounting on failure as it is already paused
         require(_doAccounting(false), "fuse still blown");

contracts/test/strategies/nativeSSVStaking.js

@@ -4,6 +4,7 @@
 const {
   setBalance,
   setStorageAt,
+  mine,
 } = require("@nomicfoundation/hardhat-network-helpers");
 
 const { isCI } = require("../helpers");
@@ -12,6 +13,7 @@
 const { shouldBehaveLikeStrategy } = require("../behaviour/strategy");
 const { MAX_UINT256 } = require("../../utils/constants");
 const { impersonateAndFund } = require("../../utils/signers");
+const minFixAccountingCadence = 7200 + 1;
 
 const {
   createFixtureLoader,
@@ -543,6 +545,7 @@
       const { nativeStakingSSVStrategy, strategist } = fixture;
 
       await nativeStakingSSVStrategy.connect(strategist).pause();
+      await mine(minFixAccountingCadence);
 
       await expect(
         nativeStakingSSVStrategy.connect(strategist).manuallyFixAccounting(
@@ -563,6 +566,7 @@
       const { nativeStakingSSVStrategy, strategist } = fixture;
 
       await nativeStakingSSVStrategy.connect(strategist).pause();
+      await mine(minFixAccountingCadence);
 
       await expect(
         nativeStakingSSVStrategy.connect(strategist).manuallyFixAccounting(
@@ -587,6 +591,7 @@
           await setActiveDepositedValidators(10, nativeStakingSSVStrategy);
 
           await nativeStakingSSVStrategy.connect(strategist).pause();
+          await mine(minFixAccountingCadence);
           const activeDepositedValidatorsBefore =
             await nativeStakingSSVStrategy.activeDepositedValidators();
 
@@ -619,6 +624,7 @@
           await setActiveDepositedValidators(10000, nativeStakingSSVStrategy);
 
           await nativeStakingSSVStrategy.connect(strategist).pause();
+          await mine(minFixAccountingCadence);
           const consensusRewardsDelta = parseEther(delta.toString());
 
           const tx = await nativeStakingSSVStrategy
@@ -647,6 +653,7 @@
           .transfer(nativeStakingSSVStrategy.address, parseEther("5"));
 
         await nativeStakingSSVStrategy.connect(strategist).pause();
+        await mine(minFixAccountingCadence);
         // unit test fixture sets OUSD governor as accounting governor
         const tx = await nativeStakingSSVStrategy
           .connect(strategist)
@@ -662,6 +669,50 @@
             parseEther("2.3") // consensusRewards
           );
       });
+
+      it("Calling manually fix accounting too often should result in an error", async () => {
+        const { nativeStakingSSVStrategy, strategist, governor } = fixture;
+
+        await nativeStakingSSVStrategy.connect(strategist).pause();
+        await mine(minFixAccountingCadence);
+        await nativeStakingSSVStrategy
+          .connect(strategist)
+          .manuallyFixAccounting(
+            0, //_validatorsDelta
+            parseEther("0") //_consensusRewardsDelta
+          );
+
+        await nativeStakingSSVStrategy.connect(strategist).pause();
+        await mine(minFixAccountingCadence - 4);
+        await expect(
+          nativeStakingSSVStrategy.connect(strategist).manuallyFixAccounting(
+            0, //_validatorsDelta
+            parseEther("0") //_consensusRewardsDelta
+          )
+        ).to.be.revertedWith("manuallyFixAccounting called too soon");
+      });
+
+      it("Calling manually fix accounting twice with enough blocks in between should pass", async () => {
+        const { nativeStakingSSVStrategy, strategist, governor } = fixture;
+
+        await nativeStakingSSVStrategy.connect(strategist).pause();
+        await mine(minFixAccountingCadence);
+        await nativeStakingSSVStrategy
+          .connect(strategist)
+          .manuallyFixAccounting(
+            0, //_validatorsDelta
+            parseEther("0") //_consensusRewardsDelta
+          );
+
+        await nativeStakingSSVStrategy.connect(strategist).pause();
+        await mine(minFixAccountingCadence);
+        await nativeStakingSSVStrategy
+          .connect(strategist)
+          .manuallyFixAccounting(
+            0, //_validatorsDelta
+            parseEther("0") //_consensusRewardsDelta
+          );
+      });
     });
   });