CoW Swap finally working

Author: miohtama

contracts/guard/src/GuardV0Base.sol

@@ -728,9 +728,10 @@ abstract contract GuardV0Base is IGuard,  Multicall, SwapCowSwap  {
     }
 
     // https://github.com/cowprotocol/contracts/tree/main/deployments
-    function whitelistCowSwap(address settlementContract, string calldata notes) external {
+    function whitelistCowSwap(address settlementContract, address relayerContract, string calldata notes) external {
         // Interaction by special _swapAndValidateCowSwap() internal function
         allowApprovalDestination(settlementContract, notes);
+        allowApprovalDestination(relayerContract, notes);
         allowedCowSwaps[settlementContract] = true;
         emit CowSwapApproved(settlementContract, notes);
     }
@@ -740,14 +741,17 @@ abstract contract GuardV0Base is IGuard,  Multicall, SwapCowSwap  {
      *
      * Checks that an asset manager tries to perform a legit CowSwap swap.
      *
-     * 1. Create a Order instance
-     * 2. Calculate its hash, also known as orderUi
-     * 3. Call setPreSignature(orderUid, True) on CowSwap
-     * 4. Offchain logic can now take over to fill the order
-     *     4.a) Read the emitted order data from OrderSigned event
-     *     4.b) Submit to CowSwap offchain settlement system
-     *     4.c) Wait for order to be filled
+     * 1. Validate the swap is within our allowed whitelists
+     * 2. Create a Order structure
+     * 3. Calculate order data hash and prefix with additional information to create order UID
+     * 4. Set up data needed to call ICowSettlement.setPreSignature(orderUid, True) from Gnosis Safe as a
+     * 5. Return data to call setPreSignature(orderUid, True) on CowSwap by Safe
+     * 6. Offchain logic can now take over to fill the order
+     *     6.a) Read the emitted order data from OrderSigned event
+     *     6.b) Submit to CowSwap offchain settlement system
+     *     6.c) Wait for order to be filled
      *
+     * Assume receiver is the same as owner that is the same as the Gnosis Safe address.
      */
     function _swapAndValidateCowSwap(
         address settlementContract,
@@ -757,7 +761,7 @@ abstract contract GuardV0Base is IGuard,  Multicall, SwapCowSwap  {
         address tokenOut,
         uint256 amountIn,
         uint256 minAmountOut
-    ) internal returns (bytes memory) {
+    ) internal returns (PresignDeletaCallData memory) {
         // Assume sender is trade-executor hot wallet
         require(isAllowedCowSwap(settlementContract), "swapAndValidateCowSwap: Cow Swap not enabled");
         require(isAllowedSender(msg.sender), "swapAndValidateCowSwap: Sender not asset manager");
@@ -774,6 +778,7 @@ abstract contract GuardV0Base is IGuard,  Multicall, SwapCowSwap  {
         );
         return _signCowSwapOrder(
             settlementContract,
+            receiver,
             order
         );
     }

contracts/guard/src/lib/SwapCowSwap.sol

@@ -19,6 +19,8 @@ import {GPv2Order} from "./GPv2Order.sol";
 //
 // Construct order structure and does it "pre-sign" on CowSwap settlement contract
 //
+// Currently does the minimal sell order support only.
+//
 contract SwapCowSwap {
 
     // How long are our CowSwap orders valid for
@@ -31,6 +33,14 @@ contract SwapCowSwap {
         uint256 indexed timestamp, bytes orderUid, GPv2Order.Data order, uint32 validTo, uint256 buyAmount, uint256 sellAmount
     );
 
+    // Gnosis Safe delegatecall information to presign CowSwap order
+    struct PresignDeletaCallData {
+        bytes orderUid;
+        address targetAddress;
+        bytes data;
+    }
+
+    // Perform sell (exact in) order creation with a max slippage limit
     // Copied from https://github.com/InfiniFi-Labs/infinifi-protocol/blob/888c147c4d0f1848577463bc74680c86b7a5c0ff/src/integrations/farms/CoWSwapFarmBase.sol#L71
     function _createCowSwapOrder(bytes32 appdata, address receiver, address _tokenIn, address _tokenOut, uint256 _amountIn, uint256 _minAmountOut)
         internal
@@ -46,23 +56,37 @@ contract SwapCowSwap {
             validTo: uint32(block.timestamp + _SIGN_COOLDOWN),
             appData: appdata,
             feeAmount: 0,
-            kind: GPv2Order.KIND_BUY,
+            kind: GPv2Order.KIND_SELL,
             partiallyFillable: false,
             sellTokenBalance: GPv2Order.BALANCE_ERC20,
             buyTokenBalance: GPv2Order.BALANCE_ERC20
         });
     }
 
     // Copied from https://github.com/InfiniFi-Labs/infinifi-protocol/blob/888c147c4d0f1848577463bc74680c86b7a5c0ff/src/integrations/farms/CoWSwapFarmBase.sol#L93C1-L102C6
-    // The main entry point for performing a swap via CowSwap
-    function _signCowSwapOrder(address settlementContract, GPv2Order.Data memory order) internal returns (bytes memory) {
+    // Takes the order structure and prepares order UID.
+    // This order UID must be passed to Gnosis Safe delegatecall to be called at ICowSettlement.setPreSignature(orderUid, true)
+    function _signCowSwapOrder(address settlementContract, address owner, GPv2Order.Data memory order) internal returns (PresignDeletaCallData memory) {
         ICowSettlement settlement = ICowSettlement(payable(settlementContract));
         bytes32 orderDigest = GPv2Order.hash(order, settlement.domainSeparator());
+
+        // Fill in order UID bytes
         bytes memory orderUid = new bytes(GPv2Order.UID_LENGTH);
-        GPv2Order.packOrderUidParams(orderUid, orderDigest, address(this), order.validTo);
-        settlement.setPreSignature(orderUid, true);
+        GPv2Order.packOrderUidParams(orderUid, orderDigest, owner, order.validTo);
+
+        // Notify our offchain logic about the created order UID
         emit OrderSigned(block.timestamp, orderUid, order, order.validTo, order.buyAmount, order.sellAmount);
-        return orderUid;
+
+        return PresignDeletaCallData({
+            orderUid: orderUid,
+            targetAddress: settlementContract,
+            data: abi.encodeWithSelector(
+                ICowSettlement.setPreSignature.selector,
+                orderUid,
+                true
+            )
+        });
+
     }
 
 }

contracts/safe-integration/src/TradingStrategyModuleV0.sol

@@ -117,8 +117,12 @@ contract TradingStrategyModuleV0 is Module, GuardV0Base {
         address tokenOut,
         uint256 amountIn,
         uint256 minAmountOut
-    ) external returns (bytes memory) {
-        return _swapAndValidateCowSwap(
+    ) public {
+        bool success;
+        bytes memory response;
+
+        // Checks for asset manager (msg.sender), receiver, etc.
+        PresignDeletaCallData memory presignDeletaCallData = _swapAndValidateCowSwap(
             settlementContract,
             receiver,
             appData,
@@ -127,6 +131,20 @@ contract TradingStrategyModuleV0 is Module, GuardV0Base {
             amountIn,
             minAmountOut
         );
+        // Perform ICowSettlement.setPresigned() call on the behalf of the Safe
+        (success, response) = execAndReturnData(
+            presignDeletaCallData.targetAddress,
+            0,
+            presignDeletaCallData.data,
+            Enum.Operation.Call
+        );
+
+        // Bubble up the revert reason
+        if (!success) {
+            assembly {
+                revert(add(response, 0x20), mload(response))
+            }
+       }
     }
 
 }