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Contract Diff Checker

Contract Name:
BurnMintTokenPool

Contract Source Code:

// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.24;

import {ITypeAndVersion} from "../../shared/interfaces/ITypeAndVersion.sol";
import {IBurnMintERC20} from "../../shared/token/ERC20/IBurnMintERC20.sol";

import {BurnMintTokenPoolAbstract} from "./BurnMintTokenPoolAbstract.sol";
import {TokenPool} from "./TokenPool.sol";

/// @notice This pool mints and burns a 3rd-party token.
/// @dev Pool whitelisting mode is set in the constructor and cannot be modified later.
/// It either accepts any address as originalSender, or only accepts whitelisted originalSender.
/// The only way to change whitelisting mode is to deploy a new pool.
/// If that is expected, please make sure the token's burner/minter roles are adjustable.
/// @dev This contract is a variant of BurnMintTokenPool that uses `burn(amount)`.
contract BurnMintTokenPool is BurnMintTokenPoolAbstract, ITypeAndVersion {
  string public constant override typeAndVersion = "BurnMintTokenPool 1.5.1";

  constructor(
    IBurnMintERC20 token,
    uint8 localTokenDecimals,
    address[] memory allowlist,
    address rmnProxy,
    address router
  ) TokenPool(token, localTokenDecimals, allowlist, rmnProxy, router) {}

  /// @inheritdoc BurnMintTokenPoolAbstract
  function _burn(
    uint256 amount
  ) internal virtual override {
    IBurnMintERC20(address(i_token)).burn(amount);
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface ITypeAndVersion {
  function typeAndVersion() external pure returns (string memory);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {IERC20} from "../../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";

interface IBurnMintERC20 is IERC20 {
  /// @notice Mints new tokens for a given address.
  /// @param account The address to mint the new tokens to.
  /// @param amount The number of tokens to be minted.
  /// @dev this function increases the total supply.
  function mint(address account, uint256 amount) external;

  /// @notice Burns tokens from the sender.
  /// @param amount The number of tokens to be burned.
  /// @dev this function decreases the total supply.
  function burn(uint256 amount) external;

  /// @notice Burns tokens from a given address..
  /// @param account The address to burn tokens from.
  /// @param amount The number of tokens to be burned.
  /// @dev this function decreases the total supply.
  function burn(address account, uint256 amount) external;

  /// @notice Burns tokens from a given address..
  /// @param account The address to burn tokens from.
  /// @param amount The number of tokens to be burned.
  /// @dev this function decreases the total supply.
  function burnFrom(address account, uint256 amount) external;
}

// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.24;

import {IBurnMintERC20} from "../../shared/token/ERC20/IBurnMintERC20.sol";

import {Pool} from "../libraries/Pool.sol";
import {TokenPool} from "./TokenPool.sol";

abstract contract BurnMintTokenPoolAbstract is TokenPool {
  /// @notice Contains the specific burn call for a pool.
  /// @dev overriding this method allows us to create pools with different burn signatures
  /// without duplicating the underlying logic.
  function _burn(
    uint256 amount
  ) internal virtual;

  /// @notice Burn the token in the pool
  /// @dev The _validateLockOrBurn check is an essential security check
  function lockOrBurn(
    Pool.LockOrBurnInV1 calldata lockOrBurnIn
  ) external virtual override returns (Pool.LockOrBurnOutV1 memory) {
    _validateLockOrBurn(lockOrBurnIn);

    _burn(lockOrBurnIn.amount);

    emit Burned(msg.sender, lockOrBurnIn.amount);

    return Pool.LockOrBurnOutV1({
      destTokenAddress: getRemoteToken(lockOrBurnIn.remoteChainSelector),
      destPoolData: _encodeLocalDecimals()
    });
  }

  /// @notice Mint tokens from the pool to the recipient
  /// @dev The _validateReleaseOrMint check is an essential security check
  function releaseOrMint(
    Pool.ReleaseOrMintInV1 calldata releaseOrMintIn
  ) external virtual override returns (Pool.ReleaseOrMintOutV1 memory) {
    _validateReleaseOrMint(releaseOrMintIn);

    // Calculate the local amount
    uint256 localAmount =
      _calculateLocalAmount(releaseOrMintIn.amount, _parseRemoteDecimals(releaseOrMintIn.sourcePoolData));

    // Mint to the receiver
    IBurnMintERC20(address(i_token)).mint(releaseOrMintIn.receiver, localAmount);

    emit Minted(msg.sender, releaseOrMintIn.receiver, localAmount);

    return Pool.ReleaseOrMintOutV1({destinationAmount: localAmount});
  }
}

// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.24;

import {IPoolV1} from "../interfaces/IPool.sol";
import {IRMN} from "../interfaces/IRMN.sol";
import {IRouter} from "../interfaces/IRouter.sol";

import {Ownable2StepMsgSender} from "../../shared/access/Ownable2StepMsgSender.sol";
import {Pool} from "../libraries/Pool.sol";
import {RateLimiter} from "../libraries/RateLimiter.sol";

import {IERC20} from "../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/IERC20.sol";
import {IERC20Metadata} from
  "../../vendor/openzeppelin-solidity/v4.8.3/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import {IERC165} from "../../vendor/openzeppelin-solidity/v5.0.2/contracts/utils/introspection/IERC165.sol";
import {EnumerableSet} from "../../vendor/openzeppelin-solidity/v5.0.2/contracts/utils/structs/EnumerableSet.sol";

/// @notice Base abstract class with common functions for all token pools.
/// A token pool serves as isolated place for holding tokens and token specific logic
/// that may execute as tokens move across the bridge.
/// @dev This pool supports different decimals on different chains but using this feature could impact the total number
/// of tokens in circulation. Since all of the tokens are locked/burned on the source, and a rounded amount is
/// minted/released on the destination, the number of tokens minted/released could be less than the number of tokens
/// burned/locked. This is because the source chain does not know about the destination token decimals. This is not a
/// problem if the decimals are the same on both chains.
///
/// Example:
/// Assume there is a token with 6 decimals on chain A and 3 decimals on chain B.
/// - 1.234567 tokens are burned on chain A.
/// - 1.234    tokens are minted on chain B.
/// When sending the 1.234 tokens back to chain A, you will receive 1.234000 tokens on chain A, effectively losing
/// 0.000567 tokens.
/// In the case of a burnMint pool on chain A, these funds are burned in the pool on chain A.
/// In the case of a lockRelease pool on chain A, these funds accumulate in the pool on chain A.
abstract contract TokenPool is IPoolV1, Ownable2StepMsgSender {
  using EnumerableSet for EnumerableSet.Bytes32Set;
  using EnumerableSet for EnumerableSet.AddressSet;
  using EnumerableSet for EnumerableSet.UintSet;
  using RateLimiter for RateLimiter.TokenBucket;

  error CallerIsNotARampOnRouter(address caller);
  error ZeroAddressNotAllowed();
  error SenderNotAllowed(address sender);
  error AllowListNotEnabled();
  error NonExistentChain(uint64 remoteChainSelector);
  error ChainNotAllowed(uint64 remoteChainSelector);
  error CursedByRMN();
  error ChainAlreadyExists(uint64 chainSelector);
  error InvalidSourcePoolAddress(bytes sourcePoolAddress);
  error InvalidToken(address token);
  error Unauthorized(address caller);
  error PoolAlreadyAdded(uint64 remoteChainSelector, bytes remotePoolAddress);
  error InvalidRemotePoolForChain(uint64 remoteChainSelector, bytes remotePoolAddress);
  error InvalidRemoteChainDecimals(bytes sourcePoolData);
  error OverflowDetected(uint8 remoteDecimals, uint8 localDecimals, uint256 remoteAmount);
  error InvalidDecimalArgs(uint8 expected, uint8 actual);

  event Locked(address indexed sender, uint256 amount);
  event Burned(address indexed sender, uint256 amount);
  event Released(address indexed sender, address indexed recipient, uint256 amount);
  event Minted(address indexed sender, address indexed recipient, uint256 amount);
  event ChainAdded(
    uint64 remoteChainSelector,
    bytes remoteToken,
    RateLimiter.Config outboundRateLimiterConfig,
    RateLimiter.Config inboundRateLimiterConfig
  );
  event ChainConfigured(
    uint64 remoteChainSelector,
    RateLimiter.Config outboundRateLimiterConfig,
    RateLimiter.Config inboundRateLimiterConfig
  );
  event ChainRemoved(uint64 remoteChainSelector);
  event RemotePoolAdded(uint64 indexed remoteChainSelector, bytes remotePoolAddress);
  event RemotePoolRemoved(uint64 indexed remoteChainSelector, bytes remotePoolAddress);
  event AllowListAdd(address sender);
  event AllowListRemove(address sender);
  event RouterUpdated(address oldRouter, address newRouter);
  event RateLimitAdminSet(address rateLimitAdmin);

  struct ChainUpdate {
    uint64 remoteChainSelector; // Remote chain selector
    bytes[] remotePoolAddresses; // Address of the remote pool, ABI encoded in the case of a remote EVM chain.
    bytes remoteTokenAddress; // Address of the remote token, ABI encoded in the case of a remote EVM chain.
    RateLimiter.Config outboundRateLimiterConfig; // Outbound rate limited config, meaning the rate limits for all of the onRamps for the given chain
    RateLimiter.Config inboundRateLimiterConfig; // Inbound rate limited config, meaning the rate limits for all of the offRamps for the given chain
  }

  struct RemoteChainConfig {
    RateLimiter.TokenBucket outboundRateLimiterConfig; // Outbound rate limited config, meaning the rate limits for all of the onRamps for the given chain
    RateLimiter.TokenBucket inboundRateLimiterConfig; // Inbound rate limited config, meaning the rate limits for all of the offRamps for the given chain
    bytes remoteTokenAddress; // Address of the remote token, ABI encoded in the case of a remote EVM chain.
    EnumerableSet.Bytes32Set remotePools; // Set of remote pool hashes, ABI encoded in the case of a remote EVM chain.
  }

  /// @dev The bridgeable token that is managed by this pool. Pools could support multiple tokens at the same time if
  /// required, but this implementation only supports one token.
  IERC20 internal immutable i_token;
  /// @dev The number of decimals of the token managed by this pool.
  uint8 internal immutable i_tokenDecimals;
  /// @dev The address of the RMN proxy
  address internal immutable i_rmnProxy;
  /// @dev The immutable flag that indicates if the pool is access-controlled.
  bool internal immutable i_allowlistEnabled;
  /// @dev A set of addresses allowed to trigger lockOrBurn as original senders.
  /// Only takes effect if i_allowlistEnabled is true.
  /// This can be used to ensure only token-issuer specified addresses can move tokens.
  EnumerableSet.AddressSet internal s_allowlist;
  /// @dev The address of the router
  IRouter internal s_router;
  /// @dev A set of allowed chain selectors. We want the allowlist to be enumerable to
  /// be able to quickly determine (without parsing logs) who can access the pool.
  /// @dev The chain selectors are in uint256 format because of the EnumerableSet implementation.
  EnumerableSet.UintSet internal s_remoteChainSelectors;
  mapping(uint64 remoteChainSelector => RemoteChainConfig) internal s_remoteChainConfigs;
  /// @notice A mapping of hashed pool addresses to their unhashed form. This is used to be able to find the actually
  /// configured pools and not just their hashed versions.
  mapping(bytes32 poolAddressHash => bytes poolAddress) internal s_remotePoolAddresses;
  /// @notice The address of the rate limiter admin.
  /// @dev Can be address(0) if none is configured.
  address internal s_rateLimitAdmin;

  constructor(IERC20 token, uint8 localTokenDecimals, address[] memory allowlist, address rmnProxy, address router) {
    if (address(token) == address(0) || router == address(0) || rmnProxy == address(0)) revert ZeroAddressNotAllowed();
    i_token = token;
    i_rmnProxy = rmnProxy;

    try IERC20Metadata(address(token)).decimals() returns (uint8 actualTokenDecimals) {
      if (localTokenDecimals != actualTokenDecimals) {
        revert InvalidDecimalArgs(localTokenDecimals, actualTokenDecimals);
      }
    } catch {
      // The decimals function doesn't exist, which is possible since it's optional in the ERC20 spec. We skip the check and
      // assume the supplied token decimals are correct.
    }
    i_tokenDecimals = localTokenDecimals;

    s_router = IRouter(router);

    // Pool can be set as permissioned or permissionless at deployment time only to save hot-path gas.
    i_allowlistEnabled = allowlist.length > 0;
    if (i_allowlistEnabled) {
      _applyAllowListUpdates(new address[](0), allowlist);
    }
  }

  /// @inheritdoc IPoolV1
  function isSupportedToken(
    address token
  ) public view virtual returns (bool) {
    return token == address(i_token);
  }

  /// @notice Gets the IERC20 token that this pool can lock or burn.
  /// @return token The IERC20 token representation.
  function getToken() public view returns (IERC20 token) {
    return i_token;
  }

  /// @notice Get RMN proxy address
  /// @return rmnProxy Address of RMN proxy
  function getRmnProxy() public view returns (address rmnProxy) {
    return i_rmnProxy;
  }

  /// @notice Gets the pool's Router
  /// @return router The pool's Router
  function getRouter() public view returns (address router) {
    return address(s_router);
  }

  /// @notice Sets the pool's Router
  /// @param newRouter The new Router
  function setRouter(
    address newRouter
  ) public onlyOwner {
    if (newRouter == address(0)) revert ZeroAddressNotAllowed();
    address oldRouter = address(s_router);
    s_router = IRouter(newRouter);

    emit RouterUpdated(oldRouter, newRouter);
  }

  /// @notice Signals which version of the pool interface is supported
  function supportsInterface(
    bytes4 interfaceId
  ) public pure virtual override returns (bool) {
    return interfaceId == Pool.CCIP_POOL_V1 || interfaceId == type(IPoolV1).interfaceId
      || interfaceId == type(IERC165).interfaceId;
  }

  // ================================================================
  // │                         Validation                           │
  // ================================================================

  /// @notice Validates the lock or burn input for correctness on
  /// - token to be locked or burned
  /// - RMN curse status
  /// - allowlist status
  /// - if the sender is a valid onRamp
  /// - rate limit status
  /// @param lockOrBurnIn The input to validate.
  /// @dev This function should always be called before executing a lock or burn. Not doing so would allow
  /// for various exploits.
  function _validateLockOrBurn(
    Pool.LockOrBurnInV1 calldata lockOrBurnIn
  ) internal {
    if (!isSupportedToken(lockOrBurnIn.localToken)) revert InvalidToken(lockOrBurnIn.localToken);
    if (IRMN(i_rmnProxy).isCursed(bytes16(uint128(lockOrBurnIn.remoteChainSelector)))) revert CursedByRMN();
    _checkAllowList(lockOrBurnIn.originalSender);

    _onlyOnRamp(lockOrBurnIn.remoteChainSelector);
    _consumeOutboundRateLimit(lockOrBurnIn.remoteChainSelector, lockOrBurnIn.amount);
  }

  /// @notice Validates the release or mint input for correctness on
  /// - token to be released or minted
  /// - RMN curse status
  /// - if the sender is a valid offRamp
  /// - if the source pool is valid
  /// - rate limit status
  /// @param releaseOrMintIn The input to validate.
  /// @dev This function should always be called before executing a release or mint. Not doing so would allow
  /// for various exploits.
  function _validateReleaseOrMint(
    Pool.ReleaseOrMintInV1 calldata releaseOrMintIn
  ) internal {
    if (!isSupportedToken(releaseOrMintIn.localToken)) revert InvalidToken(releaseOrMintIn.localToken);
    if (IRMN(i_rmnProxy).isCursed(bytes16(uint128(releaseOrMintIn.remoteChainSelector)))) revert CursedByRMN();
    _onlyOffRamp(releaseOrMintIn.remoteChainSelector);

    // Validates that the source pool address is configured on this pool.
    if (!isRemotePool(releaseOrMintIn.remoteChainSelector, releaseOrMintIn.sourcePoolAddress)) {
      revert InvalidSourcePoolAddress(releaseOrMintIn.sourcePoolAddress);
    }

    _consumeInboundRateLimit(releaseOrMintIn.remoteChainSelector, releaseOrMintIn.amount);
  }

  // ================================================================
  // │                      Token decimals                          │
  // ================================================================

  /// @notice Gets the IERC20 token decimals on the local chain.
  function getTokenDecimals() public view virtual returns (uint8 decimals) {
    return i_tokenDecimals;
  }

  function _encodeLocalDecimals() internal view virtual returns (bytes memory) {
    return abi.encode(i_tokenDecimals);
  }

  function _parseRemoteDecimals(
    bytes memory sourcePoolData
  ) internal view virtual returns (uint8) {
    // Fallback to the local token decimals if the source pool data is empty. This allows for backwards compatibility.
    if (sourcePoolData.length == 0) {
      return i_tokenDecimals;
    }
    if (sourcePoolData.length != 32) {
      revert InvalidRemoteChainDecimals(sourcePoolData);
    }
    uint256 remoteDecimals = abi.decode(sourcePoolData, (uint256));
    if (remoteDecimals > type(uint8).max) {
      revert InvalidRemoteChainDecimals(sourcePoolData);
    }
    return uint8(remoteDecimals);
  }

  /// @notice Calculates the local amount based on the remote amount and decimals.
  /// @param remoteAmount The amount on the remote chain.
  /// @param remoteDecimals The decimals of the token on the remote chain.
  /// @return The local amount.
  /// @dev This function protects against overflows. If there is a transaction that hits the overflow check, it is
  /// probably incorrect as that means the amount cannot be represented on this chain. If the local decimals have been
  /// wrongly configured, the token issuer could redeploy the pool with the correct decimals and manually re-execute the
  /// CCIP tx to fix the issue.
  function _calculateLocalAmount(uint256 remoteAmount, uint8 remoteDecimals) internal view virtual returns (uint256) {
    if (remoteDecimals == i_tokenDecimals) {
      return remoteAmount;
    }
    if (remoteDecimals > i_tokenDecimals) {
      uint8 decimalsDiff = remoteDecimals - i_tokenDecimals;
      if (decimalsDiff > 77) {
        // This is a safety check to prevent overflow in the next calculation.
        revert OverflowDetected(remoteDecimals, i_tokenDecimals, remoteAmount);
      }
      // Solidity rounds down so there is no risk of minting more tokens than the remote chain sent.
      return remoteAmount / (10 ** decimalsDiff);
    }

    // This is a safety check to prevent overflow in the next calculation.
    // More than 77 would never fit in a uint256 and would cause an overflow. We also check if the resulting amount
    // would overflow.
    uint8 diffDecimals = i_tokenDecimals - remoteDecimals;
    if (diffDecimals > 77 || remoteAmount > type(uint256).max / (10 ** diffDecimals)) {
      revert OverflowDetected(remoteDecimals, i_tokenDecimals, remoteAmount);
    }

    return remoteAmount * (10 ** diffDecimals);
  }

  // ================================================================
  // │                     Chain permissions                        │
  // ================================================================

  /// @notice Gets the pool address on the remote chain.
  /// @param remoteChainSelector Remote chain selector.
  /// @dev To support non-evm chains, this value is encoded into bytes
  function getRemotePools(
    uint64 remoteChainSelector
  ) public view returns (bytes[] memory) {
    bytes32[] memory remotePoolHashes = s_remoteChainConfigs[remoteChainSelector].remotePools.values();

    bytes[] memory remotePools = new bytes[](remotePoolHashes.length);
    for (uint256 i = 0; i < remotePoolHashes.length; ++i) {
      remotePools[i] = s_remotePoolAddresses[remotePoolHashes[i]];
    }

    return remotePools;
  }

  /// @notice Checks if the pool address is configured on the remote chain.
  /// @param remoteChainSelector Remote chain selector.
  /// @param remotePoolAddress The address of the remote pool.
  function isRemotePool(uint64 remoteChainSelector, bytes calldata remotePoolAddress) public view returns (bool) {
    return s_remoteChainConfigs[remoteChainSelector].remotePools.contains(keccak256(remotePoolAddress));
  }

  /// @notice Gets the token address on the remote chain.
  /// @param remoteChainSelector Remote chain selector.
  /// @dev To support non-evm chains, this value is encoded into bytes
  function getRemoteToken(
    uint64 remoteChainSelector
  ) public view returns (bytes memory) {
    return s_remoteChainConfigs[remoteChainSelector].remoteTokenAddress;
  }

  /// @notice Adds a remote pool for a given chain selector. This could be due to a pool being upgraded on the remote
  /// chain. We don't simply want to replace the old pool as there could still be valid inflight messages from the old
  /// pool. This function allows for multiple pools to be added for a single chain selector.
  /// @param remoteChainSelector The remote chain selector for which the remote pool address is being added.
  /// @param remotePoolAddress The address of the new remote pool.
  function addRemotePool(uint64 remoteChainSelector, bytes calldata remotePoolAddress) external onlyOwner {
    if (!isSupportedChain(remoteChainSelector)) revert NonExistentChain(remoteChainSelector);

    _setRemotePool(remoteChainSelector, remotePoolAddress);
  }

  /// @notice Removes the remote pool address for a given chain selector.
  /// @dev All inflight txs from the remote pool will be rejected after it is removed. To ensure no loss of funds, there
  /// should be no inflight txs from the given pool.
  function removeRemotePool(uint64 remoteChainSelector, bytes calldata remotePoolAddress) external onlyOwner {
    if (!isSupportedChain(remoteChainSelector)) revert NonExistentChain(remoteChainSelector);

    if (!s_remoteChainConfigs[remoteChainSelector].remotePools.remove(keccak256(remotePoolAddress))) {
      revert InvalidRemotePoolForChain(remoteChainSelector, remotePoolAddress);
    }

    emit RemotePoolRemoved(remoteChainSelector, remotePoolAddress);
  }

  /// @inheritdoc IPoolV1
  function isSupportedChain(
    uint64 remoteChainSelector
  ) public view returns (bool) {
    return s_remoteChainSelectors.contains(remoteChainSelector);
  }

  /// @notice Get list of allowed chains
  /// @return list of chains.
  function getSupportedChains() public view returns (uint64[] memory) {
    uint256[] memory uint256ChainSelectors = s_remoteChainSelectors.values();
    uint64[] memory chainSelectors = new uint64[](uint256ChainSelectors.length);
    for (uint256 i = 0; i < uint256ChainSelectors.length; ++i) {
      chainSelectors[i] = uint64(uint256ChainSelectors[i]);
    }

    return chainSelectors;
  }

  /// @notice Sets the permissions for a list of chains selectors. Actual senders for these chains
  /// need to be allowed on the Router to interact with this pool.
  /// @param remoteChainSelectorsToRemove A list of chain selectors to remove.
  /// @param chainsToAdd A list of chains and their new permission status & rate limits. Rate limits
  /// are only used when the chain is being added through `allowed` being true.
  /// @dev Only callable by the owner
  function applyChainUpdates(
    uint64[] calldata remoteChainSelectorsToRemove,
    ChainUpdate[] calldata chainsToAdd
  ) external virtual onlyOwner {
    for (uint256 i = 0; i < remoteChainSelectorsToRemove.length; ++i) {
      uint64 remoteChainSelectorToRemove = remoteChainSelectorsToRemove[i];
      // If the chain doesn't exist, revert
      if (!s_remoteChainSelectors.remove(remoteChainSelectorToRemove)) {
        revert NonExistentChain(remoteChainSelectorToRemove);
      }

      // Remove all remote pool hashes for the chain
      bytes32[] memory remotePools = s_remoteChainConfigs[remoteChainSelectorToRemove].remotePools.values();
      for (uint256 j = 0; j < remotePools.length; ++j) {
        s_remoteChainConfigs[remoteChainSelectorToRemove].remotePools.remove(remotePools[j]);
      }

      delete s_remoteChainConfigs[remoteChainSelectorToRemove];

      emit ChainRemoved(remoteChainSelectorToRemove);
    }

    for (uint256 i = 0; i < chainsToAdd.length; ++i) {
      ChainUpdate memory newChain = chainsToAdd[i];
      RateLimiter._validateTokenBucketConfig(newChain.outboundRateLimiterConfig, false);
      RateLimiter._validateTokenBucketConfig(newChain.inboundRateLimiterConfig, false);

      if (newChain.remoteTokenAddress.length == 0) {
        revert ZeroAddressNotAllowed();
      }

      // If the chain already exists, revert
      if (!s_remoteChainSelectors.add(newChain.remoteChainSelector)) {
        revert ChainAlreadyExists(newChain.remoteChainSelector);
      }

      RemoteChainConfig storage remoteChainConfig = s_remoteChainConfigs[newChain.remoteChainSelector];

      remoteChainConfig.outboundRateLimiterConfig = RateLimiter.TokenBucket({
        rate: newChain.outboundRateLimiterConfig.rate,
        capacity: newChain.outboundRateLimiterConfig.capacity,
        tokens: newChain.outboundRateLimiterConfig.capacity,
        lastUpdated: uint32(block.timestamp),
        isEnabled: newChain.outboundRateLimiterConfig.isEnabled
      });
      remoteChainConfig.inboundRateLimiterConfig = RateLimiter.TokenBucket({
        rate: newChain.inboundRateLimiterConfig.rate,
        capacity: newChain.inboundRateLimiterConfig.capacity,
        tokens: newChain.inboundRateLimiterConfig.capacity,
        lastUpdated: uint32(block.timestamp),
        isEnabled: newChain.inboundRateLimiterConfig.isEnabled
      });
      remoteChainConfig.remoteTokenAddress = newChain.remoteTokenAddress;

      for (uint256 j = 0; j < newChain.remotePoolAddresses.length; ++j) {
        _setRemotePool(newChain.remoteChainSelector, newChain.remotePoolAddresses[j]);
      }

      emit ChainAdded(
        newChain.remoteChainSelector,
        newChain.remoteTokenAddress,
        newChain.outboundRateLimiterConfig,
        newChain.inboundRateLimiterConfig
      );
    }
  }

  /// @notice Adds a pool address to the allowed remote token pools for a particular chain.
  /// @param remoteChainSelector The remote chain selector for which the remote pool address is being added.
  /// @param remotePoolAddress The address of the new remote pool.
  function _setRemotePool(uint64 remoteChainSelector, bytes memory remotePoolAddress) internal {
    if (remotePoolAddress.length == 0) {
      revert ZeroAddressNotAllowed();
    }

    bytes32 poolHash = keccak256(remotePoolAddress);

    // Check if the pool already exists.
    if (!s_remoteChainConfigs[remoteChainSelector].remotePools.add(poolHash)) {
      revert PoolAlreadyAdded(remoteChainSelector, remotePoolAddress);
    }

    // Add the pool to the mapping to be able to un-hash it later.
    s_remotePoolAddresses[poolHash] = remotePoolAddress;

    emit RemotePoolAdded(remoteChainSelector, remotePoolAddress);
  }

  // ================================================================
  // │                        Rate limiting                         │
  // ================================================================

  /// @dev The inbound rate limits should be slightly higher than the outbound rate limits. This is because many chains
  /// finalize blocks in batches. CCIP also commits messages in batches: the commit plugin bundles multiple messages in
  /// a single merkle root.
  /// Imagine the following scenario.
  /// - Chain A has an inbound and outbound rate limit of 100 tokens capacity and 1 token per second refill rate.
  /// - Chain B has an inbound and outbound rate limit of 100 tokens capacity and 1 token per second refill rate.
  ///
  /// At time 0:
  /// - Chain A sends 100 tokens to Chain B.
  /// At time 5:
  /// - Chain A sends 5 tokens to Chain B.
  /// At time 6:
  /// The epoch that contains blocks [0-5] is finalized.
  /// Both transactions will be included in the same merkle root and become executable at the same time. This means
  /// the token pool on chain B requires a capacity of 105 to successfully execute both messages at the same time.
  /// The exact additional capacity required depends on the refill rate and the size of the source chain epochs and the
  /// CCIP round time. For simplicity, a 5-10% buffer should be sufficient in most cases.

  /// @notice Sets the rate limiter admin address.
  /// @dev Only callable by the owner.
  /// @param rateLimitAdmin The new rate limiter admin address.
  function setRateLimitAdmin(
    address rateLimitAdmin
  ) external onlyOwner {
    s_rateLimitAdmin = rateLimitAdmin;
    emit RateLimitAdminSet(rateLimitAdmin);
  }

  /// @notice Gets the rate limiter admin address.
  function getRateLimitAdmin() external view returns (address) {
    return s_rateLimitAdmin;
  }

  /// @notice Consumes outbound rate limiting capacity in this pool
  function _consumeOutboundRateLimit(uint64 remoteChainSelector, uint256 amount) internal {
    s_remoteChainConfigs[remoteChainSelector].outboundRateLimiterConfig._consume(amount, address(i_token));
  }

  /// @notice Consumes inbound rate limiting capacity in this pool
  function _consumeInboundRateLimit(uint64 remoteChainSelector, uint256 amount) internal {
    s_remoteChainConfigs[remoteChainSelector].inboundRateLimiterConfig._consume(amount, address(i_token));
  }

  /// @notice Gets the token bucket with its values for the block it was requested at.
  /// @return The token bucket.
  function getCurrentOutboundRateLimiterState(
    uint64 remoteChainSelector
  ) external view returns (RateLimiter.TokenBucket memory) {
    return s_remoteChainConfigs[remoteChainSelector].outboundRateLimiterConfig._currentTokenBucketState();
  }

  /// @notice Gets the token bucket with its values for the block it was requested at.
  /// @return The token bucket.
  function getCurrentInboundRateLimiterState(
    uint64 remoteChainSelector
  ) external view returns (RateLimiter.TokenBucket memory) {
    return s_remoteChainConfigs[remoteChainSelector].inboundRateLimiterConfig._currentTokenBucketState();
  }

  /// @notice Sets the chain rate limiter config.
  /// @param remoteChainSelector The remote chain selector for which the rate limits apply.
  /// @param outboundConfig The new outbound rate limiter config, meaning the onRamp rate limits for the given chain.
  /// @param inboundConfig The new inbound rate limiter config, meaning the offRamp rate limits for the given chain.
  function setChainRateLimiterConfig(
    uint64 remoteChainSelector,
    RateLimiter.Config memory outboundConfig,
    RateLimiter.Config memory inboundConfig
  ) external {
    if (msg.sender != s_rateLimitAdmin && msg.sender != owner()) revert Unauthorized(msg.sender);

    _setRateLimitConfig(remoteChainSelector, outboundConfig, inboundConfig);
  }

  function _setRateLimitConfig(
    uint64 remoteChainSelector,
    RateLimiter.Config memory outboundConfig,
    RateLimiter.Config memory inboundConfig
  ) internal {
    if (!isSupportedChain(remoteChainSelector)) revert NonExistentChain(remoteChainSelector);
    RateLimiter._validateTokenBucketConfig(outboundConfig, false);
    s_remoteChainConfigs[remoteChainSelector].outboundRateLimiterConfig._setTokenBucketConfig(outboundConfig);
    RateLimiter._validateTokenBucketConfig(inboundConfig, false);
    s_remoteChainConfigs[remoteChainSelector].inboundRateLimiterConfig._setTokenBucketConfig(inboundConfig);
    emit ChainConfigured(remoteChainSelector, outboundConfig, inboundConfig);
  }

  // ================================================================
  // │                           Access                             │
  // ================================================================

  /// @notice Checks whether remote chain selector is configured on this contract, and if the msg.sender
  /// is a permissioned onRamp for the given chain on the Router.
  function _onlyOnRamp(
    uint64 remoteChainSelector
  ) internal view {
    if (!isSupportedChain(remoteChainSelector)) revert ChainNotAllowed(remoteChainSelector);
    if (!(msg.sender == s_router.getOnRamp(remoteChainSelector))) revert CallerIsNotARampOnRouter(msg.sender);
  }

  /// @notice Checks whether remote chain selector is configured on this contract, and if the msg.sender
  /// is a permissioned offRamp for the given chain on the Router.
  function _onlyOffRamp(
    uint64 remoteChainSelector
  ) internal view {
    if (!isSupportedChain(remoteChainSelector)) revert ChainNotAllowed(remoteChainSelector);
    if (!s_router.isOffRamp(remoteChainSelector, msg.sender)) revert CallerIsNotARampOnRouter(msg.sender);
  }

  // ================================================================
  // │                          Allowlist                           │
  // ================================================================

  function _checkAllowList(
    address sender
  ) internal view {
    if (i_allowlistEnabled) {
      if (!s_allowlist.contains(sender)) {
        revert SenderNotAllowed(sender);
      }
    }
  }

  /// @notice Gets whether the allowlist functionality is enabled.
  /// @return true is enabled, false if not.
  function getAllowListEnabled() external view returns (bool) {
    return i_allowlistEnabled;
  }

  /// @notice Gets the allowed addresses.
  /// @return The allowed addresses.
  function getAllowList() external view returns (address[] memory) {
    return s_allowlist.values();
  }

  /// @notice Apply updates to the allow list.
  /// @param removes The addresses to be removed.
  /// @param adds The addresses to be added.
  function applyAllowListUpdates(address[] calldata removes, address[] calldata adds) external onlyOwner {
    _applyAllowListUpdates(removes, adds);
  }

  /// @notice Internal version of applyAllowListUpdates to allow for reuse in the constructor.
  function _applyAllowListUpdates(address[] memory removes, address[] memory adds) internal {
    if (!i_allowlistEnabled) revert AllowListNotEnabled();

    for (uint256 i = 0; i < removes.length; ++i) {
      address toRemove = removes[i];
      if (s_allowlist.remove(toRemove)) {
        emit AllowListRemove(toRemove);
      }
    }
    for (uint256 i = 0; i < adds.length; ++i) {
      address toAdd = adds[i];
      if (toAdd == address(0)) {
        continue;
      }
      if (s_allowlist.add(toAdd)) {
        emit AllowListAdd(toAdd);
      }
    }
  }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
  /**
   * @dev Emitted when `value` tokens are moved from one account (`from`) to
   * another (`to`).
   *
   * Note that `value` may be zero.
   */
  event Transfer(address indexed from, address indexed to, uint256 value);

  /**
   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
   * a call to {approve}. `value` is the new allowance.
   */
  event Approval(address indexed owner, address indexed spender, uint256 value);

  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns the amount of tokens owned by `account`.
   */
  function balanceOf(address account) external view returns (uint256);

  /**
   * @dev Moves `amount` tokens from the caller's account to `to`.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transfer(address to, uint256 amount) external returns (bool);

  /**
   * @dev Returns the remaining number of tokens that `spender` will be
   * allowed to spend on behalf of `owner` through {transferFrom}. This is
   * zero by default.
   *
   * This value changes when {approve} or {transferFrom} are called.
   */
  function allowance(address owner, address spender) external view returns (uint256);

  /**
   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * IMPORTANT: Beware that changing an allowance with this method brings the risk
   * that someone may use both the old and the new allowance by unfortunate
   * transaction ordering. One possible solution to mitigate this race
   * condition is to first reduce the spender's allowance to 0 and set the
   * desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   *
   * Emits an {Approval} event.
   */
  function approve(address spender, uint256 amount) external returns (bool);

  /**
   * @dev Moves `amount` tokens from `from` to `to` using the
   * allowance mechanism. `amount` is then deducted from the caller's
   * allowance.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transferFrom(address from, address to, uint256 amount) external returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @notice This library contains various token pool functions to aid constructing the return data.
library Pool {
  // The tag used to signal support for the pool v1 standard.
  // bytes4(keccak256("CCIP_POOL_V1"))
  bytes4 public constant CCIP_POOL_V1 = 0xaff2afbf;

  // The number of bytes in the return data for a pool v1 releaseOrMint call.
  // This should match the size of the ReleaseOrMintOutV1 struct.
  uint16 public constant CCIP_POOL_V1_RET_BYTES = 32;

  // The default max number of bytes in the return data for a pool v1 lockOrBurn call.
  // This data can be used to send information to the destination chain token pool. Can be overwritten
  // in the TokenTransferFeeConfig.destBytesOverhead if more data is required.
  uint32 public constant CCIP_LOCK_OR_BURN_V1_RET_BYTES = 32;

  struct LockOrBurnInV1 {
    bytes receiver; //  The recipient of the tokens on the destination chain, abi encoded.
    uint64 remoteChainSelector; // ─╮ The chain ID of the destination chain.
    address originalSender; // ─────╯ The original sender of the tx on the source chain.
    uint256 amount; //  The amount of tokens to lock or burn, denominated in the source token's decimals.
    address localToken; //  The address on this chain of the token to lock or burn.
  }

  struct LockOrBurnOutV1 {
    // The address of the destination token, abi encoded in the case of EVM chains.
    // This value is UNTRUSTED as any pool owner can return whatever value they want.
    bytes destTokenAddress;
    // Optional pool data to be transferred to the destination chain. Be default this is capped at
    // CCIP_LOCK_OR_BURN_V1_RET_BYTES bytes. If more data is required, the TokenTransferFeeConfig.destBytesOverhead
    // has to be set for the specific token.
    bytes destPoolData;
  }

  struct ReleaseOrMintInV1 {
    bytes originalSender; //          The original sender of the tx on the source chain.
    uint64 remoteChainSelector; // ─╮ The chain ID of the source chain.
    address receiver; // ───────────╯ The recipient of the tokens on the destination chain.
    uint256 amount; //                The amount of tokens to release or mint, denominated in the source token's decimals.
    address localToken; //            The address on this chain of the token to release or mint.
    /// @dev WARNING: sourcePoolAddress should be checked prior to any processing of funds. Make sure it matches the
    /// expected pool address for the given remoteChainSelector.
    bytes sourcePoolAddress; //       The address of the source pool, abi encoded in the case of EVM chains.
    bytes sourcePoolData; //          The data received from the source pool to process the release or mint.
    /// @dev WARNING: offchainTokenData is untrusted data.
    bytes offchainTokenData; //       The offchain data to process the release or mint.
  }

  struct ReleaseOrMintOutV1 {
    // The number of tokens released or minted on the destination chain, denominated in the local token's decimals.
    // This value is expected to be equal to the ReleaseOrMintInV1.amount in the case where the source and destination
    // chain have the same number of decimals.
    uint256 destinationAmount;
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {Pool} from "../libraries/Pool.sol";

import {IERC165} from "../../vendor/openzeppelin-solidity/v5.0.2/contracts/utils/introspection/IERC165.sol";

/// @notice Shared public interface for multiple V1 pool types.
/// Each pool type handles a different child token model e.g. lock/unlock, mint/burn.
interface IPoolV1 is IERC165 {
  /// @notice Lock tokens into the pool or burn the tokens.
  /// @param lockOrBurnIn Encoded data fields for the processing of tokens on the source chain.
  /// @return lockOrBurnOut Encoded data fields for the processing of tokens on the destination chain.
  function lockOrBurn(
    Pool.LockOrBurnInV1 calldata lockOrBurnIn
  ) external returns (Pool.LockOrBurnOutV1 memory lockOrBurnOut);

  /// @notice Releases or mints tokens to the receiver address.
  /// @param releaseOrMintIn All data required to release or mint tokens.
  /// @return releaseOrMintOut The amount of tokens released or minted on the local chain, denominated
  /// in the local token's decimals.
  /// @dev The offramp asserts that the balanceOf of the receiver has been incremented by exactly the number
  /// of tokens that is returned in ReleaseOrMintOutV1.destinationAmount. If the amounts do not match, the tx reverts.
  function releaseOrMint(
    Pool.ReleaseOrMintInV1 calldata releaseOrMintIn
  ) external returns (Pool.ReleaseOrMintOutV1 memory);

  /// @notice Checks whether a remote chain is supported in the token pool.
  /// @param remoteChainSelector The selector of the remote chain.
  /// @return true if the given chain is a permissioned remote chain.
  function isSupportedChain(
    uint64 remoteChainSelector
  ) external view returns (bool);

  /// @notice Returns if the token pool supports the given token.
  /// @param token The address of the token.
  /// @return true if the token is supported by the pool.
  function isSupportedToken(
    address token
  ) external view returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/// @notice This interface contains the only RMN-related functions that might be used on-chain by other CCIP contracts.
interface IRMN {
  /// @notice A Merkle root tagged with the address of the commit store contract it is destined for.
  struct TaggedRoot {
    address commitStore;
    bytes32 root;
  }

  /// @notice Callers MUST NOT cache the return value as a blessed tagged root could become unblessed.
  function isBlessed(
    TaggedRoot calldata taggedRoot
  ) external view returns (bool);

  /// @notice Iff there is an active global or legacy curse, this function returns true.
  function isCursed() external view returns (bool);

  /// @notice Iff there is an active global curse, or an active curse for `subject`, this function returns true.
  /// @param subject To check whether a particular chain is cursed, set to bytes16(uint128(chainSelector)).
  function isCursed(
    bytes16 subject
  ) external view returns (bool);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import {Client} from "../libraries/Client.sol";

interface IRouter {
  error OnlyOffRamp();

  /// @notice Route the message to its intended receiver contract.
  /// @param message Client.Any2EVMMessage struct.
  /// @param gasForCallExactCheck of params for exec.
  /// @param gasLimit set of params for exec.
  /// @param receiver set of params for exec.
  /// @dev if the receiver is a contracts that signals support for CCIP execution through EIP-165.
  /// the contract is called. If not, only tokens are transferred.
  /// @return success A boolean value indicating whether the ccip message was received without errors.
  /// @return retBytes A bytes array containing return data form CCIP receiver.
  /// @return gasUsed the gas used by the external customer call. Does not include any overhead.
  function routeMessage(
    Client.Any2EVMMessage calldata message,
    uint16 gasForCallExactCheck,
    uint256 gasLimit,
    address receiver
  ) external returns (bool success, bytes memory retBytes, uint256 gasUsed);

  /// @notice Returns the configured onramp for a specific destination chain.
  /// @param destChainSelector The destination chain Id to get the onRamp for.
  /// @return onRampAddress The address of the onRamp.
  function getOnRamp(
    uint64 destChainSelector
  ) external view returns (address onRampAddress);

  /// @notice Return true if the given offRamp is a configured offRamp for the given source chain.
  /// @param sourceChainSelector The source chain selector to check.
  /// @param offRamp The address of the offRamp to check.
  function isOffRamp(uint64 sourceChainSelector, address offRamp) external view returns (bool isOffRamp);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import {Ownable2Step} from "./Ownable2Step.sol";

/// @notice Sets the msg.sender to be the owner of the contract and does not set a pending owner.
contract Ownable2StepMsgSender is Ownable2Step {
  constructor() Ownable2Step(msg.sender, address(0)) {}
}

// SPDX-License-Identifier: BUSL-1.1
pragma solidity ^0.8.4;

/// @notice Implements Token Bucket rate limiting.
/// @dev uint128 is safe for rate limiter state.
/// - For USD value rate limiting, it can adequately store USD value in 18 decimals.
/// - For ERC20 token amount rate limiting, all tokens that will be listed will have at most a supply of uint128.max
/// tokens, and it will therefore not overflow the bucket. In exceptional scenarios where tokens consumed may be larger
/// than uint128, e.g. compromised issuer, an enabled RateLimiter will check and revert.
library RateLimiter {
  error BucketOverfilled();
  error OnlyCallableByAdminOrOwner();
  error TokenMaxCapacityExceeded(uint256 capacity, uint256 requested, address tokenAddress);
  error TokenRateLimitReached(uint256 minWaitInSeconds, uint256 available, address tokenAddress);
  error AggregateValueMaxCapacityExceeded(uint256 capacity, uint256 requested);
  error AggregateValueRateLimitReached(uint256 minWaitInSeconds, uint256 available);
  error InvalidRateLimitRate(Config rateLimiterConfig);
  error DisabledNonZeroRateLimit(Config config);
  error RateLimitMustBeDisabled();

  event TokensConsumed(uint256 tokens);
  event ConfigChanged(Config config);

  struct TokenBucket {
    uint128 tokens; // ──────╮ Current number of tokens that are in the bucket.
    uint32 lastUpdated; //   │ Timestamp in seconds of the last token refill, good for 100+ years.
    bool isEnabled; // ──────╯ Indication whether the rate limiting is enabled or not.
    uint128 capacity; // ────╮ Maximum number of tokens that can be in the bucket.
    uint128 rate; // ────────╯ Number of tokens per second that the bucket is refilled.
  }

  struct Config {
    bool isEnabled; // Indication whether the rate limiting should be enabled.
    uint128 capacity; // ────╮ Specifies the capacity of the rate limiter.
    uint128 rate; //  ───────╯ Specifies the rate of the rate limiter.
  }

  /// @notice _consume removes the given tokens from the pool, lowering the rate tokens allowed to be
  /// consumed for subsequent calls.
  /// @param requestTokens The total tokens to be consumed from the bucket.
  /// @param tokenAddress The token to consume capacity for, use 0x0 to indicate aggregate value capacity.
  /// @dev Reverts when requestTokens exceeds bucket capacity or available tokens in the bucket.
  /// @dev emits removal of requestTokens if requestTokens is > 0.
  function _consume(TokenBucket storage s_bucket, uint256 requestTokens, address tokenAddress) internal {
    // If there is no value to remove or rate limiting is turned off, skip this step to reduce gas usage.
    if (!s_bucket.isEnabled || requestTokens == 0) {
      return;
    }

    uint256 tokens = s_bucket.tokens;
    uint256 capacity = s_bucket.capacity;
    uint256 timeDiff = block.timestamp - s_bucket.lastUpdated;

    if (timeDiff != 0) {
      if (tokens > capacity) revert BucketOverfilled();

      // Refill tokens when arriving at a new block time.
      tokens = _calculateRefill(capacity, tokens, timeDiff, s_bucket.rate);

      s_bucket.lastUpdated = uint32(block.timestamp);
    }

    if (capacity < requestTokens) {
      // Token address 0 indicates consuming aggregate value rate limit capacity.
      if (tokenAddress == address(0)) revert AggregateValueMaxCapacityExceeded(capacity, requestTokens);
      revert TokenMaxCapacityExceeded(capacity, requestTokens, tokenAddress);
    }
    if (tokens < requestTokens) {
      uint256 rate = s_bucket.rate;
      // Wait required until the bucket is refilled enough to accept this value, round up to next higher second.
      // Consume is not guaranteed to succeed after wait time passes if there is competing traffic.
      // This acts as a lower bound of wait time.
      uint256 minWaitInSeconds = ((requestTokens - tokens) + (rate - 1)) / rate;

      if (tokenAddress == address(0)) revert AggregateValueRateLimitReached(minWaitInSeconds, tokens);
      revert TokenRateLimitReached(minWaitInSeconds, tokens, tokenAddress);
    }
    tokens -= requestTokens;

    // Downcast is safe here, as tokens is not larger than capacity.
    s_bucket.tokens = uint128(tokens);
    emit TokensConsumed(requestTokens);
  }

  /// @notice Gets the token bucket with its values for the block it was requested at.
  /// @return The token bucket.
  function _currentTokenBucketState(
    TokenBucket memory bucket
  ) internal view returns (TokenBucket memory) {
    // We update the bucket to reflect the status at the exact time of the call. This means we might need to refill a
    // part of the bucket based on the time that has passed since the last update.
    bucket.tokens =
      uint128(_calculateRefill(bucket.capacity, bucket.tokens, block.timestamp - bucket.lastUpdated, bucket.rate));
    bucket.lastUpdated = uint32(block.timestamp);
    return bucket;
  }

  /// @notice Sets the rate limited config.
  /// @param s_bucket The token bucket.
  /// @param config The new config.
  function _setTokenBucketConfig(TokenBucket storage s_bucket, Config memory config) internal {
    // First update the bucket to make sure the proper rate is used for all the time up until the config change.
    uint256 timeDiff = block.timestamp - s_bucket.lastUpdated;
    if (timeDiff != 0) {
      s_bucket.tokens = uint128(_calculateRefill(s_bucket.capacity, s_bucket.tokens, timeDiff, s_bucket.rate));

      s_bucket.lastUpdated = uint32(block.timestamp);
    }

    s_bucket.tokens = uint128(_min(config.capacity, s_bucket.tokens));
    s_bucket.isEnabled = config.isEnabled;
    s_bucket.capacity = config.capacity;
    s_bucket.rate = config.rate;

    emit ConfigChanged(config);
  }

  /// @notice Validates the token bucket config.
  function _validateTokenBucketConfig(Config memory config, bool mustBeDisabled) internal pure {
    if (config.isEnabled) {
      if (config.rate >= config.capacity || config.rate == 0) {
        revert InvalidRateLimitRate(config);
      }
      if (mustBeDisabled) {
        revert RateLimitMustBeDisabled();
      }
    } else {
      if (config.rate != 0 || config.capacity != 0) {
        revert DisabledNonZeroRateLimit(config);
      }
    }
  }

  /// @notice Calculate refilled tokens.
  /// @param capacity bucket capacity.
  /// @param tokens current bucket tokens.
  /// @param timeDiff block time difference since last refill.
  /// @param rate bucket refill rate.
  /// @return the value of tokens after refill.
  function _calculateRefill(
    uint256 capacity,
    uint256 tokens,
    uint256 timeDiff,
    uint256 rate
  ) private pure returns (uint256) {
    return _min(capacity, tokens + timeDiff * rate);
  }

  /// @notice Return the smallest of two integers.
  /// @param a first int.
  /// @param b second int.
  /// @return smallest.
  function _min(uint256 a, uint256 b) internal pure returns (uint256) {
    return a < b ? a : b;
  }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
  /**
   * @dev Returns the name of the token.
   */
  function name() external view returns (string memory);

  /**
   * @dev Returns the symbol of the token.
   */
  function symbol() external view returns (string memory);

  /**
   * @dev Returns the decimals places of the token.
   */
  function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/introspection/IERC165.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (utils/structs/EnumerableSet.sol)
// This file was procedurally generated from scripts/generate/templates/EnumerableSet.js.

pragma solidity ^0.8.20;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```solidity
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
 * and `uint256` (`UintSet`) are supported.
 *
 * [WARNING]
 * ====
 * Trying to delete such a structure from storage will likely result in data corruption, rendering the structure
 * unusable.
 * See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
 *
 * In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an
 * array of EnumerableSet.
 * ====
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;
        // Position is the index of the value in the `values` array plus 1.
        // Position 0 is used to mean a value is not in the set.
        mapping(bytes32 value => uint256) _positions;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._positions[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We cache the value's position to prevent multiple reads from the same storage slot
        uint256 position = set._positions[value];

        if (position != 0) {
            // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 valueIndex = position - 1;
            uint256 lastIndex = set._values.length - 1;

            if (valueIndex != lastIndex) {
                bytes32 lastValue = set._values[lastIndex];

                // Move the lastValue to the index where the value to delete is
                set._values[valueIndex] = lastValue;
                // Update the tracked position of the lastValue (that was just moved)
                set._positions[lastValue] = position;
            }

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the tracked position for the deleted slot
            delete set._positions[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._positions[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        return set._values[index];
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function _values(Set storage set) private view returns (bytes32[] memory) {
        return set._values;
    }

    // Bytes32Set

    struct Bytes32Set {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _add(set._inner, value);
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
        return _remove(set._inner, value);
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
        return _contains(set._inner, value);
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(Bytes32Set storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
        return _at(set._inner, index);
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
        bytes32[] memory store = _values(set._inner);
        bytes32[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(uint160(value))));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint160(uint256(_at(set._inner, index))));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(AddressSet storage set) internal view returns (address[] memory) {
        bytes32[] memory store = _values(set._inner);
        address[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }

    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

    /**
     * @dev Returns the value stored at position `index` in the set. O(1).
     *
     * Note that there are no guarantees on the ordering of values inside the
     * array, and it may change when more values are added or removed.
     *
     * Requirements:
     *
     * - `index` must be strictly less than {length}.
     */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }

    /**
     * @dev Return the entire set in an array
     *
     * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
     * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
     * this function has an unbounded cost, and using it as part of a state-changing function may render the function
     * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
     */
    function values(UintSet storage set) internal view returns (uint256[] memory) {
        bytes32[] memory store = _values(set._inner);
        uint256[] memory result;

        /// @solidity memory-safe-assembly
        assembly {
            result := store
        }

        return result;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// End consumer library.
library Client {
  /// @dev RMN depends on this struct, if changing, please notify the RMN maintainers.
  struct EVMTokenAmount {
    address token; // token address on the local chain.
    uint256 amount; // Amount of tokens.
  }

  struct Any2EVMMessage {
    bytes32 messageId; // MessageId corresponding to ccipSend on source.
    uint64 sourceChainSelector; // Source chain selector.
    bytes sender; // abi.decode(sender) if coming from an EVM chain.
    bytes data; // payload sent in original message.
    EVMTokenAmount[] destTokenAmounts; // Tokens and their amounts in their destination chain representation.
  }

  // If extraArgs is empty bytes, the default is 200k gas limit.
  struct EVM2AnyMessage {
    bytes receiver; // abi.encode(receiver address) for dest EVM chains.
    bytes data; // Data payload.
    EVMTokenAmount[] tokenAmounts; // Token transfers.
    address feeToken; // Address of feeToken. address(0) means you will send msg.value.
    bytes extraArgs; // Populate this with _argsToBytes(EVMExtraArgsV2).
  }

  // bytes4(keccak256("CCIP EVMExtraArgsV1"));
  bytes4 public constant EVM_EXTRA_ARGS_V1_TAG = 0x97a657c9;

  struct EVMExtraArgsV1 {
    uint256 gasLimit;
  }

  function _argsToBytes(
    EVMExtraArgsV1 memory extraArgs
  ) internal pure returns (bytes memory bts) {
    return abi.encodeWithSelector(EVM_EXTRA_ARGS_V1_TAG, extraArgs);
  }

  // bytes4(keccak256("CCIP EVMExtraArgsV2"));
  bytes4 public constant EVM_EXTRA_ARGS_V2_TAG = 0x181dcf10;

  /// @param gasLimit: gas limit for the callback on the destination chain.
  /// @param allowOutOfOrderExecution: if true, it indicates that the message can be executed in any order relative to
  /// other messages from the same sender. This value's default varies by chain. On some chains, a particular value is
  /// enforced, meaning if the expected value is not set, the message request will revert.
  struct EVMExtraArgsV2 {
    uint256 gasLimit;
    bool allowOutOfOrderExecution;
  }

  function _argsToBytes(
    EVMExtraArgsV2 memory extraArgs
  ) internal pure returns (bytes memory bts) {
    return abi.encodeWithSelector(EVM_EXTRA_ARGS_V2_TAG, extraArgs);
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import {IOwnable} from "../interfaces/IOwnable.sol";

/// @notice A minimal contract that implements 2-step ownership transfer and nothing more. It's made to be minimal
/// to reduce the impact of the bytecode size on any contract that inherits from it.
contract Ownable2Step is IOwnable {
  /// @notice The pending owner is the address to which ownership may be transferred.
  address private s_pendingOwner;
  /// @notice The owner is the current owner of the contract.
  /// @dev The owner is the second storage variable so any implementing contract could pack other state with it
  /// instead of the much less used s_pendingOwner.
  address private s_owner;

  error OwnerCannotBeZero();
  error MustBeProposedOwner();
  error CannotTransferToSelf();
  error OnlyCallableByOwner();

  event OwnershipTransferRequested(address indexed from, address indexed to);
  event OwnershipTransferred(address indexed from, address indexed to);

  constructor(address newOwner, address pendingOwner) {
    if (newOwner == address(0)) {
      revert OwnerCannotBeZero();
    }

    s_owner = newOwner;
    if (pendingOwner != address(0)) {
      _transferOwnership(pendingOwner);
    }
  }

  /// @notice Get the current owner
  function owner() public view override returns (address) {
    return s_owner;
  }

  /// @notice Allows an owner to begin transferring ownership to a new address. The new owner needs to call
  /// `acceptOwnership` to accept the transfer before any permissions are changed.
  /// @param to The address to which ownership will be transferred.
  function transferOwnership(address to) public override onlyOwner {
    _transferOwnership(to);
  }

  /// @notice validate, transfer ownership, and emit relevant events
  /// @param to The address to which ownership will be transferred.
  function _transferOwnership(address to) private {
    if (to == msg.sender) {
      revert CannotTransferToSelf();
    }

    s_pendingOwner = to;

    emit OwnershipTransferRequested(s_owner, to);
  }

  /// @notice Allows an ownership transfer to be completed by the recipient.
  function acceptOwnership() external override {
    if (msg.sender != s_pendingOwner) {
      revert MustBeProposedOwner();
    }

    address oldOwner = s_owner;
    s_owner = msg.sender;
    s_pendingOwner = address(0);

    emit OwnershipTransferred(oldOwner, msg.sender);
  }

  /// @notice validate access
  function _validateOwnership() internal view {
    if (msg.sender != s_owner) {
      revert OnlyCallableByOwner();
    }
  }

  /// @notice Reverts if called by anyone other than the contract owner.
  modifier onlyOwner() {
    _validateOwnership();
    _;
  }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface IOwnable {
  function owner() external returns (address);

  function transferOwnership(address recipient) external;

  function acceptOwnership() external;
}

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