evm: add EQ02 body and quote vs execution method

Author: evan-gray

design/02_On_Chain_Quotes.md

@@ -160,14 +160,14 @@ uint64  expiryTime;       // The unix time, in seconds, after which this quote s
 
 ### Quote - Version 2
 
-This introduces a new Quote version to the [Executor spec](../README.md#api--database-schema).
-
-<aside>
-⚠️ TBD if the `baseFee`, `destinationGasPrice`, `sourcePrice`, and `destinationPrice` fields should be required akin to `EQ01`. We are assessing the additional cost to implement this or provide an equivalent way to gather this data off-chain.
-</aside>
+This introduces a new Quote version to the [Executor spec](../README.md#api--database-schema). It has the same body as `EQ01` sans signature. This is useful for parsing and validating off-chain.
 
 ```solidity
 Header   header              // prefix = "EQ02"
+uint64   baseFee             // The base fee, in sourceChain native currency, required by the quoter to perform an execution on the destination chain
+uint64   destinationGasPrice // The current gas price on the destination chain
+uint64   sourcePrice         // The USD price, in 10^10, of the sourceChain native currency
+uint64   destinationPrice    // The USD price, in 10^10, of the destinationChain native currency
 ```
 
 # **Caveats**

evm/src/ExecutorQuoter.sol

@@ -17,15 +17,16 @@ contract ExecutorQuoter is IExecutorQuoter {
 
     /// This is the same as an EQ01 quote body
     /// It fits into a single bytes32 storage slot
+    /// It is listed in reverse order so that it is stored in the correct order (EVM stores right to left)
     struct OnChainQuoteBody {
-        /// The base fee, in sourceChain native currency, required by the quoter to perform an execution on the destination chain
-        uint64 baseFee;
-        /// The current gas price on the destination chain
-        uint64 dstGasPrice;
-        /// The USD price, in 10^10, of the sourceChain native currency
-        uint64 srcPrice;
         /// The USD price, in 10^10, of the destinationChain native currency
         uint64 dstPrice;
+        /// The USD price, in 10^10, of the sourceChain native currency
+        uint64 srcPrice;
+        /// The current gas price on the destination chain
+        uint64 dstGasPrice;
+        /// The base fee, in sourceChain native currency, required by the quoter to perform an execution on the destination chain
+        uint64 baseFee;
     }
 
     struct ChainInfo {
@@ -193,16 +194,37 @@ contract ExecutorQuoter is IExecutorQuoter {
         address, //refundAddr,
         bytes calldata, //requestBytes,
         bytes calldata relayInstructions
-    ) external view returns (bytes32, uint256) {
+    ) external view returns (uint256 requiredPayment) {
+        ChainInfo storage dstChainInfo = chainInfos[dstChain];
+        if (!dstChainInfo.enabled) {
+            revert ChainDisabled(dstChain);
+        }
+        (uint256 gasLimit, uint256 msgValue) = totalGasLimitAndMsgValue(relayInstructions);
+        // NOTE: this does not include any maxGasLimit or maxMsgValue checks
+        requiredPayment = estimateQuote(quoteByDstChain[dstChain], dstChainInfo, gasLimit, msgValue);
+
+        return requiredPayment;
+    }
+
+    function requestExecutionQuote(
+        uint16 dstChain,
+        bytes32, //dstAddr,
+        address, //refundAddr,
+        bytes calldata, //requestBytes,
+        bytes calldata relayInstructions
+    ) external view returns (uint256 requiredPayment, bytes32, bytes32 quoteBody) {
         ChainInfo storage dstChainInfo = chainInfos[dstChain];
         if (!dstChainInfo.enabled) {
             revert ChainDisabled(dstChain);
         }
         OnChainQuoteBody storage quote = quoteByDstChain[dstChain];
+        assembly {
+            quoteBody := sload(quote.slot)
+        }
         (uint256 gasLimit, uint256 msgValue) = totalGasLimitAndMsgValue(relayInstructions);
         // NOTE: this does not include any maxGasLimit or maxMsgValue checks
-        uint256 requiredPayment = estimateQuote(quote, dstChainInfo, gasLimit, msgValue);
+        requiredPayment = estimateQuote(quote, dstChainInfo, gasLimit, msgValue);
 
-        return (PAYEE_ADDRESS, requiredPayment);
+        return (requiredPayment, PAYEE_ADDRESS, quoteBody);
     }
 }

evm/src/ExecutorQuoterRouter.sol

@@ -100,7 +100,7 @@ contract ExecutorQuoterRouter is IExecutorQuoterRouter {
         bytes calldata requestBytes,
         bytes calldata relayInstructions
     ) external view returns (uint256 requiredPayment) {
-        (, requiredPayment) =
+        requiredPayment =
             quoterContract[quoterAddr].requestQuote(dstChain, dstAddr, refundAddr, requestBytes, relayInstructions);
     }
 
@@ -113,8 +113,8 @@ contract ExecutorQuoterRouter is IExecutorQuoterRouter {
         bytes calldata relayInstructions
     ) external payable {
         IExecutorQuoter implementation = quoterContract[quoterAddr];
-        (bytes32 payeeAddress, uint256 requiredPayment) =
-            implementation.requestQuote(dstChain, dstAddr, refundAddr, requestBytes, relayInstructions);
+        (uint256 requiredPayment, bytes32 payeeAddress, bytes32 quoteBody) =
+            implementation.requestExecutionQuote(dstChain, dstAddr, refundAddr, requestBytes, relayInstructions);
         if (msg.value < requiredPayment) {
             revert Underpaid(msg.value, requiredPayment);
         }
@@ -128,7 +128,7 @@ contract ExecutorQuoterRouter is IExecutorQuoterRouter {
             dstChain,
             dstAddr,
             refundAddr,
-            abi.encodePacked(QUOTE_PREFIX, quoterAddr, payeeAddress, OUR_CHAIN, dstChain, EXPIRY_TIME),
+            abi.encodePacked(QUOTE_PREFIX, quoterAddr, payeeAddress, OUR_CHAIN, dstChain, EXPIRY_TIME, quoteBody),
             requestBytes,
             relayInstructions
         );

evm/src/interfaces/IExecutorQuoter.sol

@@ -2,11 +2,25 @@
 pragma solidity ^0.8.19;
 
 interface IExecutorQuoter {
+    /// This method is used by on- or off-chain services which need to determine the cost of a relay
+    /// It only returns the required cost (msg.value)
+    /// It is explicitly marked view
     function requestQuote(
         uint16 dstChain,
         bytes32 dstAddr,
         address refundAddr,
         bytes calldata requestBytes,
         bytes calldata relayInstructions
-    ) external view returns (bytes32, uint256);
+    ) external view returns (uint256);
+
+    /// This method is used by an ExecutorQuoterRouter during the execution flow
+    /// It returns the required cost (msg.value) in addition to the payee and EQ02 quote body
+    /// It is explicitly NOT marked view in order to allow the quoter the flexibility to emit events or update state
+    function requestExecutionQuote(
+        uint16 dstChain,
+        bytes32 dstAddr,
+        address refundAddr,
+        bytes calldata requestBytes,
+        bytes calldata relayInstructions
+    ) external returns (uint256, bytes32, bytes32);
 }

evm/test/ExecutorQuoter.t.sol

@@ -18,7 +18,7 @@ contract ExecutorQuoterTest is Test {
     bytes32 constant DST_ADDR = bytes32(0);
 
     function packUint64(uint64 a, uint64 b, uint64 c, uint64 d) public pure returns (bytes32) {
-        return bytes32((uint256(d) << 192) | (uint256(c) << 128) | (uint256(b) << 64) | uint256(a));
+        return bytes32((uint256(a) << 192) | (uint256(b) << 128) | (uint256(c) << 64) | uint256(d));
     }
 
     function setUp() public {
@@ -69,7 +69,7 @@ contract ExecutorQuoterTest is Test {
 
     function test_quoteUpdate() public {
         executorQuoter.quoteUpdate(updates);
-        (uint64 baseFee,,,) = executorQuoter.quoteByDstChain(10003);
+        (,,, uint64 baseFee) = executorQuoter.quoteByDstChain(10003);
         require(baseFee == 27971);
     }
 
@@ -86,4 +86,14 @@ contract ExecutorQuoterTest is Test {
             RelayInstructions.encodeGas(250000, 0)
         );
     }
+
+    function test_requestExecutionQuote() public view {
+        executorQuoter.requestExecutionQuote(
+            DST_CHAIN,
+            DST_ADDR,
+            UPDATER,
+            ExecutorMessages.makeVAAv1Request(10002, bytes32(uint256(uint160(address(this)))), 1),
+            RelayInstructions.encodeGas(250000, 0)
+        );
+    }
 }

evm/test/ExecutorQuoterRouter.t.sol

@@ -28,7 +28,7 @@ contract ExecutorQuoterRouterTest is Test {
     bytes32 constant DST_ADDR = bytes32(0);
 
     function packUint64(uint64 a, uint64 b, uint64 c, uint64 d) public pure returns (bytes32) {
-        return bytes32((uint256(d) << 192) | (uint256(c) << 128) | (uint256(b) << 64) | uint256(a));
+        return bytes32((uint256(a) << 192) | (uint256(b) << 128) | (uint256(c) << 64) | uint256(d));
     }
 
     function setUp() public {