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Diffstat (limited to 'contracts/extensions/contracts/Forwarder/MixinWeth.sol')
-rw-r--r-- | contracts/extensions/contracts/Forwarder/MixinWeth.sol | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/contracts/extensions/contracts/Forwarder/MixinWeth.sol b/contracts/extensions/contracts/Forwarder/MixinWeth.sol new file mode 100644 index 000000000..2a281f3ae --- /dev/null +++ b/contracts/extensions/contracts/Forwarder/MixinWeth.sol @@ -0,0 +1,113 @@ +/* + + Copyright 2018 ZeroEx Intl. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. + +*/ + +pragma solidity 0.4.24; + +import "@0x/contracts-libs/contracts/libs/LibMath.sol"; +import "./libs/LibConstants.sol"; +import "./mixins/MWeth.sol"; + + +contract MixinWeth is + LibMath, + LibConstants, + MWeth +{ + /// @dev Default payabale function, this allows us to withdraw WETH + function () + public + payable + { + require( + msg.sender == address(ETHER_TOKEN), + "DEFAULT_FUNCTION_WETH_CONTRACT_ONLY" + ); + } + + /// @dev Converts message call's ETH value into WETH. + function convertEthToWeth() + internal + { + require( + msg.value > 0, + "INVALID_MSG_VALUE" + ); + ETHER_TOKEN.deposit.value(msg.value)(); + } + + /// @dev Transfers feePercentage of WETH spent on primary orders to feeRecipient. + /// Refunds any excess ETH to msg.sender. + /// @param wethSoldExcludingFeeOrders Amount of WETH sold when filling primary orders. + /// @param wethSoldForZrx Amount of WETH sold when purchasing ZRX required for primary order fees. + /// @param feePercentage Percentage of WETH sold that will payed as fee to forwarding contract feeRecipient. + /// @param feeRecipient Address that will receive ETH when orders are filled. + function transferEthFeeAndRefund( + uint256 wethSoldExcludingFeeOrders, + uint256 wethSoldForZrx, + uint256 feePercentage, + address feeRecipient + ) + internal + { + // Ensure feePercentage is less than 5%. + require( + feePercentage <= MAX_FEE_PERCENTAGE, + "FEE_PERCENTAGE_TOO_LARGE" + ); + + // Ensure that no extra WETH owned by this contract has been sold. + uint256 wethSold = safeAdd(wethSoldExcludingFeeOrders, wethSoldForZrx); + require( + wethSold <= msg.value, + "OVERSOLD_WETH" + ); + + // Calculate amount of WETH that hasn't been sold. + uint256 wethRemaining = safeSub(msg.value, wethSold); + + // Calculate ETH fee to pay to feeRecipient. + uint256 ethFee = getPartialAmountFloor( + feePercentage, + PERCENTAGE_DENOMINATOR, + wethSoldExcludingFeeOrders + ); + + // Ensure fee is less than amount of WETH remaining. + require( + ethFee <= wethRemaining, + "INSUFFICIENT_ETH_REMAINING" + ); + + // Do nothing if no WETH remaining + if (wethRemaining > 0) { + // Convert remaining WETH to ETH + ETHER_TOKEN.withdraw(wethRemaining); + + // Pay ETH to feeRecipient + if (ethFee > 0) { + feeRecipient.transfer(ethFee); + } + + // Refund remaining ETH to msg.sender. + uint256 ethRefund = safeSub(wethRemaining, ethFee); + if (ethRefund > 0) { + msg.sender.transfer(ethRefund); + } + } + } +} |