Oracle report sanity checks

contracts/0.4.24/Lido.sol

@@ -9,7 +9,6 @@ import "@aragon/os/contracts/apps/AragonApp.sol";
 import "@aragon/os/contracts/lib/math/SafeMath.sol";
 
 import "./lib/StakeLimitUtils.sol";
-import "./lib/PositiveTokenRebaseLimiter.sol";
 
 import "./StETHPermit.sol";
 
@@ -64,7 +63,6 @@ contract Lido is StETHPermit, AragonApp {
     using UnstructuredStorage for bytes32;
     using StakeLimitUnstructuredStorage for bytes32;
     using StakeLimitUtils for StakeLimitState.Data;
-    using PositiveTokenRebaseLimiter for LimiterState.Data;
 
     /// ACL
     bytes32 public constant PAUSE_ROLE = keccak256("PAUSE_ROLE");
@@ -73,7 +71,6 @@ contract Lido is StETHPermit, AragonApp {
     bytes32 public constant STAKING_CONTROL_ROLE = keccak256("STAKING_CONTROL_ROLE");
     bytes32 public constant MANAGE_PROTOCOL_CONTRACTS_ROLE = keccak256("MANAGE_PROTOCOL_CONTRACTS_ROLE");
     bytes32 public constant BURN_ROLE = keccak256("BURN_ROLE");
-    bytes32 public constant MANAGE_MAX_POSITIVE_TOKEN_REBASE_ROLE = keccak256("MANAGE_MAX_POSITIVE_TOKEN_REBASE_ROLE");
 
     uint256 private constant DEPOSIT_SIZE = 32 ether;
     uint256 public constant TOTAL_BASIS_POINTS = 10000;
@@ -97,9 +94,6 @@ contract Lido is StETHPermit, AragonApp {
     /// @dev number of Lido's validators available in the Consensus Layer state
     // "beacon" in the `keccak256()` parameter is staying here for compatibility reason
     bytes32 internal constant CL_VALIDATORS_POSITION = keccak256("lido.Lido.beaconValidators");
-    /// @dev positive token rebase allowed per single LidoOracle report
-    /// uses 1e9 precision, e.g.: 1e6 - 0.1%; 1e9 - 100%, see `setMaxPositiveTokenRebase()`
-    bytes32 internal constant MAX_POSITIVE_TOKEN_REBASE_POSITION = keccak256("lido.Lido.MaxPositiveTokenRebase");
     /// @dev Just a counter of total amount of execution layer rewards received by Lido contract. Not used in the logic.
     bytes32 internal constant TOTAL_EL_REWARDS_COLLECTED_POSITION = keccak256("lido.Lido.totalELRewardsCollected");
     /// @dev version of contract
@@ -124,9 +118,6 @@ contract Lido is StETHPermit, AragonApp {
     // The amount of ETH withdrawn from LidoExecutionLayerRewardsVault contract to Lido contract
     event ELRewardsReceived(uint256 amount);
 
-    // Max positive token rebase set (see `setMaxPositiveTokenRebase()`)
-    event MaxPositiveTokenRebaseSet(uint256 maxPositiveTokenRebase);
-
     // Records a deposit made by a user
     event Submitted(address indexed sender, uint256 amount, address referral);
 
@@ -460,36 +451,6 @@ contract Lido is StETHPermit, AragonApp {
         _setProtocolContracts(_oracle, _treasury, _executionLayerRewardsVault);
     }
 
-    /**
-     * @dev Set max positive rebase allowed per single oracle report
-     * token rebase happens on total supply adjustment,
-     * huge positive rebase can incur oracle report sandwitching.
-     *
-     * stETH balance for the `account` defined as:
-     * balanceOf(account) = shares[account] * totalPooledEther / totalShares = shares[account] * shareRate
-     *
-     * Suppose shareRate changes when oracle reports (see `handleOracleReport`)
-     * which means that token rebase happens:
-     *
-     * preShareRate = preTotalPooledEther() / preTotalShares()
-     * postShareRate = postTotalPooledEther() / postTotalShares()
-     * R = (postShareRate - preShareRate) / preShareRate
-     *
-     * R > 0 corresponds to the relative positive rebase value (i.e., instant APR)
-     *
-     * NB: The value is not set by default (explicit initialization required),
-     * the recommended sane values are from 0.05% to 0.1%.
-     *
-     * @param _maxTokenPositiveRebase max positive token rebase value with 1e9 precision:
-     *   e.g.: 1e6 - 0.1%; 1e9 - 100%
-     * - passing zero value is prohibited
-     * - to allow unlimited rebases, pass max uint256, i.e.: type(uint256).max
-     */
-    function setMaxPositiveTokenRebase(uint256 _maxTokenPositiveRebase) external {
-        _auth(MANAGE_MAX_POSITIVE_TOKEN_REBASE_ROLE);
-        _setMaxPositiveTokenRebase(_maxTokenPositiveRebase);
-    }
-
     /**
     * @notice Updates accounting stats, collects EL rewards and distributes collected rewards if beacon balance increased
     * @dev periodically called by the Oracle contract
@@ -522,12 +483,6 @@ contract Lido is StETHPermit, AragonApp {
         require(msg.sender == getOracle(), "APP_AUTH_FAILED");
         _whenNotStopped();
 
-        LimiterState.Data memory tokenRebaseLimiter = PositiveTokenRebaseLimiter.initLimiterState(
-            getMaxPositiveTokenRebase(),
-            _getTotalPooledEther(),
-            _getTotalShares()
-        );
-
         uint256 preClBalance = CL_BALANCE_POSITION.getStorageUint256();
 
         // update saved CL stats checking its sanity
@@ -539,9 +494,9 @@ contract Lido is StETHPermit, AragonApp {
         uint256 rewardsBase = appearedValidators.mul(DEPOSIT_SIZE).add(preClBalance);
         int256 clBalanceDiff = _signedSub(int256(_clBalance), int256(rewardsBase));
 
-        tokenRebaseLimiter.applyCLBalanceUpdate(clBalanceDiff);
-        withdrawals = tokenRebaseLimiter.appendEther(_withdrawalVaultBalance);
-        elRewards = tokenRebaseLimiter.appendEther(_elRewardsVaultBalance);
+        // TODO: temporary disable limit
+        withdrawals = _withdrawalVaultBalance;
+        elRewards = _elRewardsVaultBalance;
 
         // collect ETH from EL and Withdrawal vaults and send some to WithdrawalQueue if required
         _processETHDistribution(withdrawals, elRewards, _requestIdToFinalizeUpTo, _finalizationShareRate);
@@ -610,14 +565,6 @@ contract Lido is StETHPermit, AragonApp {
         return TOTAL_EL_REWARDS_COLLECTED_POSITION.getStorageUint256();
     }
 
-    /**
-     * @notice Get max positive token rebase value
-     * @return max positive token rebase value, nominated id MAX_POSITIVE_REBASE_PRECISION_POINTS (10**9 == 100% = 10000 BP)
-     */
-    function getMaxPositiveTokenRebase() public view returns (uint256) {
-        return MAX_POSITIVE_TOKEN_REBASE_POSITION.getStorageUint256();
-    }
-
     /**
      * @notice Gets authorized oracle address
      * @return address of oracle contract
@@ -1016,16 +963,6 @@ contract Lido is StETHPermit, AragonApp {
         return _stakeLimitData.calculateCurrentStakeLimit();
     }
 
-    /**
-     * @dev Set max positive token rebase value
-     * @param _maxPositiveTokenRebase max positive token rebase, nominated in MAX_POSITIVE_REBASE_PRECISION_POINTS
-     */
-    function _setMaxPositiveTokenRebase(uint256 _maxPositiveTokenRebase) internal {
-        MAX_POSITIVE_TOKEN_REBASE_POSITION.setStorageUint256(_maxPositiveTokenRebase);
-
-        emit MaxPositiveTokenRebaseSet(_maxPositiveTokenRebase);
-    }
-
     /**
      * @dev Size-efficient analog of the `auth(_role)` modifier
      * @param _role Permission name

contracts/0.4.24/template/LidoTemplate.sol

@@ -370,8 +370,7 @@ contract LidoTemplate is IsContract {
 
     function finalizeDAO(
         string _daoName,
-        uint256 _unvestedTokensAmount,
-        uint256 _maxPositiveTokenRebase
+        uint256 _unvestedTokensAmount
     )
         external onlyOwner
     {
@@ -381,11 +380,6 @@ contract LidoTemplate is IsContract {
         require(state.dao != address(0), ERROR_DAO_NOT_DEPLOYED);
         require(bytes(_daoName).length > 0, ERROR_INVALID_ID);
 
-        bytes32 LIDO_MANAGE_MAX_POSITIVE_TOKEN_REBASE = state.lido.MANAGE_MAX_POSITIVE_TOKEN_REBASE_ROLE();
-        _createPermissionForTemplate(state.acl, state.lido, LIDO_MANAGE_MAX_POSITIVE_TOKEN_REBASE);
-        state.lido.setMaxPositiveTokenRebase(_maxPositiveTokenRebase);
-        _removePermissionFromTemplate(state.acl, state.lido, LIDO_MANAGE_MAX_POSITIVE_TOKEN_REBASE);
-
         if (_unvestedTokensAmount != 0) {
             // using issue + assign to avoid setting the additional MINT_ROLE for the template
             state.tokenManager.issue(_unvestedTokensAmount);
@@ -606,8 +600,7 @@ contract LidoTemplate is IsContract {
         perms[3] = _state.lido.RESUME_ROLE();
         perms[4] = _state.lido.STAKING_PAUSE_ROLE();
         perms[5] = _state.lido.STAKING_CONTROL_ROLE();
-        perms[6] = _state.lido.MANAGE_MAX_POSITIVE_TOKEN_REBASE_ROLE();
-        for (i = 0; i < 7; ++i) {
+        for (i = 0; i < 6; ++i) {
             _createPermissionForVoting(acl, _state.lido, perms[i], voting);
         }
     }

contracts/0.4.24/test_helpers/LidoMock.sol

@@ -50,7 +50,6 @@ contract LidoMock is Lido {
     function resumeProtocolAndStaking() public {
         _resume();
         _resumeStaking();
-        _setMaxPositiveTokenRebase(UNLIMITED_TOKEN_REBASE);
     }
 
     /**

contracts/0.4.24/test_helpers/LidoPushableMock.sol

@@ -19,7 +19,6 @@ contract LidoPushableMock is Lido {
     function initialize(address _oracle) public onlyInit {
         _setProtocolContracts(_oracle, _oracle, address(0));
         _resume();
-        _setMaxPositiveTokenRebase(UNLIMITED_TOKEN_REBASE);
         initialized();
     }
 

contracts/0.4.24/lib/PositiveTokenRebaseLimiter.sol → contracts/0.8.9/lib/PositiveTokenRebaseLimiter.sol

@@ -3,9 +3,7 @@
 // SPDX-License-Identifier: GPL-3.0
 
 /* See contracts/COMPILERS.md */
-pragma solidity 0.4.24;
-
-import {SafeMath} from "@aragon/os/contracts/lib/math/SafeMath.sol";
+pragma solidity 0.8.9;
 
 import {Math256} from "../../common/lib/Math256.sol";
 
@@ -35,31 +33,29 @@ library LimiterState {
 }
 
 library PositiveTokenRebaseLimiter {
-    using SafeMath for uint256;
-
     /// @dev Precision base for the limiter (e.g.: 1e6 - 0.1%; 1e9 - 100%)
     uint256 private constant LIMITER_PRECISION_BASE = 10**9;
     /// @dev Disabled limit
-    uint256 private constant UNLIMITED_REBASE = uint256(-1);
+    uint256 private constant UNLIMITED_REBASE = type(uint64).max;
 
     /**
       * @dev Initialize the new `LimiterState` structure instance
       * @param _rebaseLimit max limiter value (saturation point), see `LIMITER_PRECISION_POINTS`
       * @param _totalPooledEther total pooled ether, see `Lido.getTotalPooledEther()`
       * @param _totalShares total shares, see `Lido.getTotalShares()`
-      * @return newly initialized limiter structure
+      * @return limiterState newly initialized limiter structure
       */
     function initLimiterState(
         uint256 _rebaseLimit,
         uint256 _totalPooledEther,
         uint256 _totalShares
-    ) internal pure returns (LimiterState.Data memory _limiterState) {
+    ) internal pure returns (LimiterState.Data memory limiterState) {
         require(_rebaseLimit > 0, "TOO_LOW_TOKEN_REBASE_MAX");
         require(_rebaseLimit <= UNLIMITED_REBASE, "WRONG_REBASE_LIMIT");
 
-        _limiterState.totalPooledEther = _totalPooledEther;
-        _limiterState.totalShares = _totalShares;
-        _limiterState.rebaseLimit = _rebaseLimit;
+        limiterState.totalPooledEther = _totalPooledEther;
+        limiterState.totalShares = _totalShares;
+        limiterState.rebaseLimit = _rebaseLimit;
     }
 
     /**
@@ -83,9 +79,7 @@ library PositiveTokenRebaseLimiter {
         require(_limiterState.accumulatedRebase == 0, "DIRTY_LIMITER_STATE");
 
         if (_clBalanceDiff < 0 && (_limiterState.rebaseLimit != UNLIMITED_REBASE)) {
-            _limiterState.rebaseLimit = _limiterState.rebaseLimit.add(
-                uint256(-_clBalanceDiff).mul(LIMITER_PRECISION_BASE).div(_limiterState.totalPooledEther)
-            );
+            _limiterState.rebaseLimit += (uint256(-_clBalanceDiff) * LIMITER_PRECISION_BASE) / _limiterState.totalPooledEther;
         } else {
             appendEther(_limiterState, uint256(_clBalanceDiff));
         }
@@ -95,7 +89,7 @@ library PositiveTokenRebaseLimiter {
      * @dev append ether and return value not exceeding the limit
      * @param _limiterState limit repr struct
      * @param _etherAmount desired ether addition
-     * @return allowed to add ether to not exceed the limit
+     * @return appendableEther allowed to add ether to not exceed the limit
      */
     function appendEther(LimiterState.Data memory _limiterState, uint256 _etherAmount)
         internal
@@ -104,25 +98,25 @@ library PositiveTokenRebaseLimiter {
     {
         if (_limiterState.rebaseLimit == UNLIMITED_REBASE) return _etherAmount;
 
-        uint256 remainingRebase = _limiterState.rebaseLimit.sub(_limiterState.accumulatedRebase);
-        uint256 remainingEther = remainingRebase.mul(_limiterState.totalPooledEther).div(LIMITER_PRECISION_BASE);
+        uint256 remainingRebase = _limiterState.rebaseLimit - _limiterState.accumulatedRebase;
+        uint256 remainingEther = (remainingRebase * _limiterState.totalPooledEther) / LIMITER_PRECISION_BASE;
 
         appendableEther = Math256.min(remainingEther, _etherAmount);
 
         if (appendableEther == remainingEther) {
             _limiterState.accumulatedRebase = _limiterState.rebaseLimit;
         } else {
-            _limiterState.accumulatedRebase = _limiterState.accumulatedRebase.add(
-                appendableEther.mul(LIMITER_PRECISION_BASE).div(_limiterState.totalPooledEther)
-            );
+            _limiterState.accumulatedRebase += (
+                appendableEther * LIMITER_PRECISION_BASE
+            ) / _limiterState.totalPooledEther;
         }
     }
 
     /**
      * @dev deduct shares and return value not exceeding the limit
      * @param _limiterState limit repr struct
      * @param _sharesAmount desired shares deduction
-     * @return allowed to deduct shares to not exceed the limit
+     * @return deductableShares allowed to deduct shares to not exceed the limit
      */
     function deductShares(LimiterState.Data memory _limiterState, uint256 _sharesAmount)
         internal
@@ -131,19 +125,19 @@ library PositiveTokenRebaseLimiter {
     {
         if (_limiterState.rebaseLimit == UNLIMITED_REBASE) return _sharesAmount;
 
-        uint256 remainingRebase = _limiterState.rebaseLimit.sub(_limiterState.accumulatedRebase);
-        uint256 remainingShares = _limiterState.totalShares.mul(remainingRebase).div(
-            LIMITER_PRECISION_BASE.add(remainingRebase)
-        );
+        uint256 remainingRebase = _limiterState.rebaseLimit - _limiterState.accumulatedRebase;
+        uint256 remainingShares = (
+            _limiterState.totalShares * remainingRebase
+        ) / (LIMITER_PRECISION_BASE + remainingRebase);
 
         deductableShares = Math256.min(_sharesAmount, remainingShares);
 
         if (deductableShares == remainingShares) {
             _limiterState.accumulatedRebase = _limiterState.rebaseLimit;
         } else {
-            _limiterState.accumulatedRebase = _limiterState.accumulatedRebase.add(
-                deductableShares.mul(LIMITER_PRECISION_BASE).div(_limiterState.totalShares.sub(deductableShares))
-            );
+            _limiterState.accumulatedRebase += (
+                deductableShares * LIMITER_PRECISION_BASE
+            ) / (_limiterState.totalShares - deductableShares);
         }
     }