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chore: Fix review bugs
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@ChefCupcake
ChefCupcake committed Dec 30, 2024
1 parent 6f4bec3 commit aa7f1ab
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Showing 2 changed files with 30 additions and 15 deletions.
33 changes: 24 additions & 9 deletions src/pool-cl/anti-sniping/CLAntiSniping.sol
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,7 @@ import {SafeCast} from "pancake-v4-core/src/libraries/SafeCast.sol";

/// @title AntiSnipingHook
/// @notice A PancakeSwap V4 hook that prevents MEV sniping attacks by enforcing time locks on positions and redistributing fees accrued in the initial block to legitimate liquidity providers.
/// Notice this hook only prevents getting fees from swaps or donations in the same block, but does not prevent any other type of MEV attacks such as sandwiching or frontrunning swaps.
/// @dev Positions are time-locked, and fees accrued in the first block after position creation are redistributed.
contract CLAntiSniping is CLBaseHook {
using PoolIdLibrary for PoolKey;
Expand All @@ -35,9 +36,13 @@ contract CLAntiSniping is CLBaseHook {
/// @notice The duration (in blocks) for which a position must remain locked before it can be removed.
uint128 public immutable positionLockDuration;

uint128 public constant MAX_LOCK_DURATION = 7500000;

/// @notice The maximum number of positions that can be created in the same block per pool to prevent excessive gas usage.
uint128 public immutable sameBlockPositionsLimit;

uint128 public constant MIN_SAME_BLOCK_POSITIONS_LIMIT = 50;

mapping(PoolId => uint256) lastProcessedBlockNumber;

mapping(PoolId => bytes32[]) positionsCreatedInLastBlock;
Expand Down Expand Up @@ -71,8 +76,16 @@ contract CLAntiSniping is CLBaseHook {
constructor(ICLPoolManager poolManager, uint128 _positionLockDuration, uint128 _sameBlockPositionsLimit)
CLBaseHook(poolManager)
{
positionLockDuration = _positionLockDuration;
sameBlockPositionsLimit = _sameBlockPositionsLimit;
if (_positionLockDuration < MAX_LOCK_DURATION) {
positionLockDuration = _positionLockDuration;
} else {
positionLockDuration = MAX_LOCK_DURATION;
}
if (_sameBlockPositionsLimit > MIN_SAME_BLOCK_POSITIONS_LIMIT) {
sameBlockPositionsLimit = _sameBlockPositionsLimit;
} else {
sameBlockPositionsLimit = MIN_SAME_BLOCK_POSITIONS_LIMIT;
}
}

function getHooksRegistrationBitmap() external pure override returns (uint16) {
Expand Down Expand Up @@ -112,9 +125,9 @@ contract CLAntiSniping is CLBaseHook {
(uint256 feeGrowthInside0X128, uint256 feeGrowthInside1X128) = _getFeeGrowthInside(poolId, params.sender, params.tickLower, params.tickUpper, params.salt);
uint256 feeGrowthDelta0X128 = feeGrowthInside0X128 - info.feeGrowthInside0LastX128;
uint256 feeGrowthDelta1X128 = feeGrowthInside1X128 - info.feeGrowthInside1LastX128;
firstBlockFeesToken0[poolId][positionKey] =
firstBlockFeesToken0[poolId][positionKey] +=
FullMath.mulDiv(feeGrowthDelta0X128, info.liquidity, FixedPoint128.Q128);
firstBlockFeesToken1[poolId][positionKey] =
firstBlockFeesToken1[poolId][positionKey] +=
FullMath.mulDiv(feeGrowthDelta1X128, info.liquidity, FixedPoint128.Q128);
}

Expand All @@ -130,7 +143,7 @@ contract CLAntiSniping is CLBaseHook {
BalanceDelta,
BalanceDelta,
bytes calldata
) external override returns (bytes4, BalanceDelta) {
) external override poolManagerOnly returns (bytes4, BalanceDelta) {
PoolId poolId = key.toId();
bytes32 positionKey = CLPosition.calculatePositionKey(sender, params.tickLower, params.tickUpper, params.salt);

Expand Down Expand Up @@ -163,7 +176,7 @@ contract CLAntiSniping is CLBaseHook {
PoolKey calldata key,
ICLPoolManager.ModifyLiquidityParams calldata params,
bytes calldata
) external override returns (bytes4) {
) external override poolManagerOnly returns (bytes4) {
PoolId poolId = key.toId();
collectLastBlockInfo(poolId);
bytes32 positionKey = CLPosition.calculatePositionKey(sender, params.tickLower, params.tickUpper, params.salt);
Expand All @@ -174,7 +187,7 @@ contract CLAntiSniping is CLBaseHook {
liqParams.salt = params.salt;

if (positionCreationBlock[poolId][positionKey] != 0 &&
block.number - positionCreationBlock[poolId][positionKey] < positionLockDuration) {
block.number - positionCreationBlock[poolId][positionKey] <= positionLockDuration) {
revert PositionAlreadyExistsAndLocked();
}
if (positionsCreatedInLastBlock[poolId].length >= sameBlockPositionsLimit) revert TooManyPositionsInSameBlock();
Expand All @@ -193,11 +206,11 @@ contract CLAntiSniping is CLBaseHook {
PoolKey calldata key,
ICLPoolManager.ModifyLiquidityParams calldata params,
bytes calldata
) external override returns (bytes4) {
) external override poolManagerOnly returns (bytes4) {
PoolId poolId = key.toId();
collectLastBlockInfo(poolId);
bytes32 positionKey = CLPosition.calculatePositionKey(sender, params.tickLower, params.tickUpper, params.salt);
if (block.number - positionCreationBlock[poolId][positionKey] < positionLockDuration) revert PositionLocked();
if (block.number - positionCreationBlock[poolId][positionKey] <= positionLockDuration) revert PositionLocked();
CLPosition.Info memory info = poolManager.getPosition(poolId, sender, params.tickLower, params.tickUpper, params.salt);
if (int128(info.liquidity) + params.liquidityDelta != 0) revert PositionPartiallyWithdrawn();
return (this.beforeRemoveLiquidity.selector);
Expand All @@ -208,6 +221,7 @@ contract CLAntiSniping is CLBaseHook {
function beforeSwap(address, PoolKey calldata key, ICLPoolManager.SwapParams calldata, bytes calldata)
external
override
poolManagerOnly
returns (bytes4, BeforeSwapDelta, uint24)
{
PoolId poolId = key.toId();
Expand All @@ -220,6 +234,7 @@ contract CLAntiSniping is CLBaseHook {
function beforeDonate(address, PoolKey calldata key, uint256, uint256, bytes calldata)
external
override
poolManagerOnly
returns (bytes4)
{
PoolId poolId = key.toId();
Expand Down
12 changes: 6 additions & 6 deletions test/pool-cl/CLAntiSniping.t.sol
View file
Original file line number Diff line number Diff line change
Expand Up @@ -268,7 +268,7 @@ contract AntiSnipingTest is Test, Deployers, DeployPermit2 {
assertEq(antiSniping.firstBlockFeesToken1(poolId, bobPositionKey), 0);

// Advance to after position lock duration
vm.roll(POSITION_LOCK_DURATION + 2);
vm.roll(POSITION_LOCK_DURATION + 3);

// Bob removes liquidity
_decreaseLiquidityPosition(BOB, bobTokenId, 10000 ether, ZERO_BYTES);
Expand Down Expand Up @@ -332,7 +332,7 @@ contract AntiSnipingTest is Test, Deployers, DeployPermit2 {
assertApproxEqRel(antiSniping.firstBlockFeesToken1(poolId, bobPositionKey), token1Donation / 2, allowedError);

// Advance to after position lock duration
vm.roll(POSITION_LOCK_DURATION + 2);
vm.roll(POSITION_LOCK_DURATION + 3);

// Bob removes liquidity
_decreaseLiquidityPosition(BOB, bobTokenId, 10000 ether, ZERO_BYTES);
Expand Down Expand Up @@ -378,7 +378,7 @@ contract AntiSnipingTest is Test, Deployers, DeployPermit2 {
assertApproxEqAbsDecimal(antiSniping.firstBlockFeesToken0(poolId, alicePositionKey), token0ExpectedFees, 1e15, 18);

// Advance to after position lock duration
vm.roll(POSITION_LOCK_DURATION + 1);
vm.roll(POSITION_LOCK_DURATION + 2);

// Alice removes liquidity
_decreaseLiquidityPosition(ALICE, aliceTokenId, 10000 ether, ZERO_BYTES);
Expand Down Expand Up @@ -406,7 +406,7 @@ contract AntiSnipingTest is Test, Deployers, DeployPermit2 {
_increaseLiquidityPosition(ALICE, aliceTokenId, 10000 ether, ZERO_BYTES);

// Advance to after position lock duration
vm.roll(POSITION_LOCK_DURATION + 1);
vm.roll(POSITION_LOCK_DURATION + 3);

// Alice add liquidity
_increaseLiquidityPosition(ALICE, aliceTokenId, 10000 ether, ZERO_BYTES);
Expand All @@ -419,7 +419,7 @@ contract AntiSnipingTest is Test, Deployers, DeployPermit2 {
uint256 token0ExpectedFees = (uint256(swapAmount) * FEE) / 1e6; // Swap amount * fee percentage

// Advance to after position lock duration
vm.roll(POSITION_LOCK_DURATION + 3);
vm.roll(POSITION_LOCK_DURATION + 4);
_performSwapExactOutputSingle(CANDY, false, swapAmount);
uint256 token1ExpectedFees = (uint256(swapAmount) * FEE) / 1e6;

Expand All @@ -439,7 +439,7 @@ contract AntiSnipingTest is Test, Deployers, DeployPermit2 {
_decreaseLiquidityPosition(ALICE, aliceTokenId, 20000 ether, ZERO_BYTES);

// Advance to after position lock duration
vm.roll(POSITION_LOCK_DURATION + POSITION_LOCK_DURATION + 2);
vm.roll(POSITION_LOCK_DURATION + POSITION_LOCK_DURATION + 5);

// Attempt to remove liquidity partially and expect revert
vm.expectRevert();
Expand Down

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