// SPDX-License-Identifier: MIT OR Apache-2.0 pragma solidity >=0.6.11; // ============ Internal Imports ============ import {BridgeMessage} from "./BridgeMessage.sol"; import {Encoding} from "./Encoding.sol"; import {IBridgeToken} from "../../interfaces/bridge/IBridgeToken.sol"; import {XAppConnectionClient} from "../XAppConnectionClient.sol"; // ============ External Imports ============ import {TypeCasts} from "@celo-org/optics-sol/contracts/XAppConnectionManager.sol"; import {UpgradeBeaconProxy} from "@celo-org/optics-sol/contracts/upgrade/UpgradeBeaconProxy.sol"; import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol"; import {TypedMemView} from "@summa-tx/memview-sol/contracts/TypedMemView.sol"; import {Initializable} from "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol"; /** * @title TokenRegistry * @notice manages a registry of token contracts on this chain * - * We sort token types as "representation token" or "locally originating token". * Locally originating - a token contract that was originally deployed on the local chain * Representation (repr) - a token that was originally deployed on some other chain * - * When the router handles an incoming message, it determines whether the * transfer is for an asset of local origin. If not, it checks for an existing * representation contract. If no such representation exists, it deploys a new * representation contract. It then stores the relationship in the * "reprToCanonical" and "canonicalToRepr" mappings to ensure we can always * perform a lookup in either direction * Note that locally originating tokens should NEVER be represented in these lookup tables. */ abstract contract TokenRegistry is Initializable { // ============ Libraries ============ using TypedMemView for bytes; using TypedMemView for bytes29; using BridgeMessage for bytes29; // ============ Structs ============ // Tokens are identified by a TokenId: // domain - 4 byte chain ID of the chain from which the token originates // id - 32 byte identifier of the token address on the origin chain, in that chain's address format struct TokenId { uint32 domain; bytes32 id; } // ============ Public Storage ============ // UpgradeBeacon from which new token proxies will get their implementation address public tokenBeacon; // local representation token address => token ID mapping(address => TokenId) public representationToCanonical; // hash of the tightly-packed TokenId => local representation token address // If the token is of local origin, this MUST map to address(0). mapping(bytes32 => address) public canonicalToRepresentation; // ============ Events ============ event TokenDeployed( uint32 indexed domain, bytes32 indexed id, address indexed representation ); // ======== Initializer ========= /** * @notice Initialize the TokenRegistry with UpgradeBeaconController and * XappConnectionManager. * @dev This method deploys two new contracts, and may be expensive to call. * @param _tokenBeacon The address of the upgrade beacon for bridge token * proxies */ function __TokenRegistry_initialize(address _tokenBeacon) internal initializer { tokenBeacon = _tokenBeacon; } // ======== External: Token Lookup Convenience ========= /** * @notice Looks up the canonical identifier for a local representation. * @dev If no such canonical ID is known, this instead returns (0, bytes32(0)) * @param _local The local address of the representation */ function getCanonicalAddress(address _local) external view returns (uint32 _domain, bytes32 _id) { TokenId memory _canonical = representationToCanonical[_local]; _domain = _canonical.domain; _id = _canonical.id; } /** * @notice Looks up the local address corresponding to a domain/id pair. * @dev If the token is local, it will return the local address. * If the token is non-local and no local representation exists, this * will return `address(0)`. * @param _domain the domain of the canonical version. * @param _id the identifier of the canonical version in its domain. * @return _token the local address of the token contract */ function getLocalAddress(uint32 _domain, address _id) external view returns (address _token) { _token = getLocalAddress(_domain, TypeCasts.addressToBytes32(_id)); } // ======== Public: Token Lookup Convenience ========= /** * @notice Looks up the local address corresponding to a domain/id pair. * @dev If the token is local, it will return the local address. * If the token is non-local and no local representation exists, this * will return `address(0)`. * @param _domain the domain of the canonical version. * @param _id the identifier of the canonical version in its domain. * @return _token the local address of the token contract */ function getLocalAddress(uint32 _domain, bytes32 _id) public view returns (address _token) { _token = _getTokenAddress(BridgeMessage.formatTokenId(_domain, _id)); } // ======== Internal Functions ========= function _localDomain() internal view virtual returns (uint32); /** * @notice Get default name and details for a token * Sets name to "optics.[domain].[id]" * and symbol to * @param _tokenId the tokenId for the token */ function _defaultDetails(bytes29 _tokenId) internal pure returns (string memory _name, string memory _symbol) { // get the first and second half of the token ID (, uint256 _secondHalfId) = Encoding.encodeHex(uint256(_tokenId.id())); // encode the default token name: "[decimal domain].[hex 4 bytes of ID]" _name = string( abi.encodePacked( Encoding.decimalUint32(_tokenId.domain()), // 10 ".", // 1 uint32(_secondHalfId) // 4 ) ); // allocate the memory for a new 32-byte string _symbol = new string(10 + 1 + 4); assembly { mstore(add(_symbol, 0x20), mload(add(_name, 0x20))) } } /** * @notice Deploy and initialize a new token contract * @dev Each token contract is a proxy which * points to the token upgrade beacon * @return _token the address of the token contract */ function _deployToken(bytes29 _tokenId) internal returns (address _token) { // deploy and initialize the token contract _token = address(new UpgradeBeaconProxy(tokenBeacon, "")); // initialize the token separately from the IBridgeToken(_token).initialize(); // set the default token name & symbol string memory _name; string memory _symbol; (_name, _symbol) = _defaultDetails(_tokenId); IBridgeToken(_token).setDetails(_name, _symbol, 18); // store token in mappings representationToCanonical[_token].domain = _tokenId.domain(); representationToCanonical[_token].id = _tokenId.id(); canonicalToRepresentation[_tokenId.keccak()] = _token; // emit event upon deploying new token emit TokenDeployed(_tokenId.domain(), _tokenId.id(), _token); } /** * @notice Get the local token address * for the canonical token represented by tokenID * Returns address(0) if canonical token is of remote origin * and no representation token has been deployed locally * @param _tokenId the token id of the canonical token * @return _local the local token address */ function _getTokenAddress(bytes29 _tokenId) internal view returns (address _local) { if (_tokenId.domain() == _localDomain()) { // Token is of local origin _local = _tokenId.evmId(); } else { // Token is a representation of a token of remote origin _local = canonicalToRepresentation[_tokenId.keccak()]; } } /** * @notice Return the local token contract for the * canonical tokenId; revert if there is no local token * @param _tokenId the token id of the canonical token * @return the IERC20 token contract */ function _mustHaveToken(bytes29 _tokenId) internal view returns (IERC20) { address _local = _getTokenAddress(_tokenId); require(_local != address(0), "!token"); return IERC20(_local); } /** * @notice Return tokenId for a local token address * @param _token local token address (representation or canonical) * @return _id local token address (representation or canonical) */ function _tokenIdFor(address _token) internal view returns (TokenId memory _id) { _id = representationToCanonical[_token]; if (_id.domain == 0) { _id.domain = _localDomain(); _id.id = TypeCasts.addressToBytes32(_token); } } /** * @notice Determine if token is of local origin * @return TRUE if token is locally originating */ function _isLocalOrigin(IERC20 _token) internal view returns (bool) { return _isLocalOrigin(address(_token)); } /** * @notice Determine if token is of local origin * @return TRUE if token is locally originating */ function _isLocalOrigin(address _token) internal view returns (bool) { // If the contract WAS deployed by the TokenRegistry, // it will be stored in this mapping. // If so, it IS NOT of local origin if (representationToCanonical[_token].domain != 0) { return false; } // If the contract WAS NOT deployed by the TokenRegistry, // and the contract exists, then it IS of local origin // Return true if code exists at _addr uint256 _codeSize; // solhint-disable-next-line no-inline-assembly assembly { _codeSize := extcodesize(_token) } return _codeSize != 0; } /** * @notice Get the local representation contract for a canonical token * @dev Returns contract with null address if tokenId has no representation * @param _tokenId the tokenId of the canonical token * @return representation token contract */ function _representationForCanonical(bytes29 _tokenId) internal view returns (IBridgeToken) { return IBridgeToken(canonicalToRepresentation[_tokenId.keccak()]); } /** * @notice Get the local representation contract for a canonical token * @dev Returns contract with null address if tokenId has no representation * @param _tokenId the tokenId of the canonical token * @return representation token contract */ function _representationForCanonical(TokenId memory _tokenId) internal view returns (IBridgeToken) { return _representationForCanonical(_serializeId(_tokenId)); } /** * @notice downcast an IERC20 to an IBridgeToken * @dev Unsafe. Please know what you're doing * @param _token the IERC20 contract * @return the IBridgeToken contract */ function _downcast(IERC20 _token) internal pure returns (IBridgeToken) { return IBridgeToken(address(_token)); } /** * @notice serialize a TokenId struct into a bytes view * @param _id the tokenId * @return serialized bytes of tokenId */ function _serializeId(TokenId memory _id) internal pure returns (bytes29) { return BridgeMessage.formatTokenId(_id.domain, _id.id); } }