Make gas fee staleness threshold configurable per chain (#1491)

## Motivation
On some chains, it is possible the gas price will just always be zero or
will be fixed at some constant fee

## Solution
Make stalenessThreshold per dest chain and have 0 mean no staleness
check

Author: RyanRHall

contracts/gas-snapshots/ccip.gas-snapshot

@@ -29,7 +29,6 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
 
   error TokenNotSupported(address token);
   error FeeTokenNotSupported(address token);
-  error ChainNotSupported(uint64 chain);
   error StaleGasPrice(uint64 destChainSelector, uint256 threshold, uint256 timePassed);
   error StaleKeystoneUpdate(address token, uint256 feedTimestamp, uint256 storedTimeStamp);
   error DataFeedValueOutOfUint224Range();
@@ -76,7 +75,8 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
   struct StaticConfig {
     uint96 maxFeeJuelsPerMsg; // ─╮ Maximum fee that can be charged for a message
     address linkToken; // ────────╯ LINK token address
-    uint32 stalenessThreshold; // The amount of time a gas price can be stale before it is considered invalid.
+    // The amount of time a token price can be stale before it is considered invalid (gas price staleness is configured per dest chain)
+    uint32 tokenPriceStalenessThreshold;
   }
 
   /// @dev The struct representing the received CCIP feed report from keystone IReceiver.onReport()
@@ -103,6 +103,7 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
     uint32 defaultTxGasLimit; //─────────────────╮ Default gas limit for a tx
     uint64 gasMultiplierWeiPerEth; //            │ Multiplier for gas costs, 1e18 based so 11e17 = 10% extra cost.
     uint32 networkFeeUSDCents; //                │ Flat network fee to charge for messages, multiples of 0.01 USD
+    uint32 gasPriceStalenessThreshold; //        │ The amount of time a gas price can be stale before it is considered invalid (0 means disabled)
     bool enforceOutOfOrder; //                   │ Whether to enforce the allowOutOfOrderExecution extraArg value to be true.
     bytes4 chainFamilySelector; // ──────────────╯ Selector that identifies the destination chain's family. Used to determine the correct validations to perform for the dest chain.
   }
@@ -202,8 +203,8 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
 
   /// @dev Subset of tokens which prices tracked by this registry which are fee tokens.
   EnumerableSet.AddressSet private s_feeTokens;
-  /// @dev The amount of time a gas price can be stale before it is considered invalid.
-  uint32 private immutable i_stalenessThreshold;
+  /// @dev The amount of time a token price can be stale before it is considered invalid.
+  uint32 private immutable i_tokenPriceStalenessThreshold;
 
   constructor(
     StaticConfig memory staticConfig,
@@ -216,14 +217,14 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
   ) AuthorizedCallers(priceUpdaters) {
     if (
       staticConfig.linkToken == address(0) || staticConfig.maxFeeJuelsPerMsg == 0
-        || staticConfig.stalenessThreshold == 0
+        || staticConfig.tokenPriceStalenessThreshold == 0
     ) {
       revert InvalidStaticConfig();
     }
 
     i_linkToken = staticConfig.linkToken;
     i_maxFeeJuelsPerMsg = staticConfig.maxFeeJuelsPerMsg;
-    i_stalenessThreshold = staticConfig.stalenessThreshold;
+    i_tokenPriceStalenessThreshold = staticConfig.tokenPriceStalenessThreshold;
 
     _applyFeeTokensUpdates(feeTokens, new address[](0));
     _updateTokenPriceFeeds(tokenPriceFeeds);
@@ -241,7 +242,7 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
     Internal.TimestampedPackedUint224 memory tokenPrice = s_usdPerToken[token];
 
     // If the token price is not stale, return it
-    if (block.timestamp - tokenPrice.timestamp < i_stalenessThreshold) {
+    if (block.timestamp - tokenPrice.timestamp < i_tokenPriceStalenessThreshold) {
       return tokenPrice;
     }
 
@@ -305,14 +306,12 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
   function getTokenAndGasPrices(
     address token,
     uint64 destChainSelector
-  ) public view returns (uint224 tokenPrice, uint224 gasPriceValue) {
-    Internal.TimestampedPackedUint224 memory gasPrice = s_usdPerUnitGasByDestChainSelector[destChainSelector];
-    // We do allow a gas price of 0, but no stale or unset gas prices
-    if (gasPrice.timestamp == 0) revert ChainNotSupported(destChainSelector);
-    uint256 timePassed = block.timestamp - gasPrice.timestamp;
-    if (timePassed > i_stalenessThreshold) revert StaleGasPrice(destChainSelector, i_stalenessThreshold, timePassed);
-
-    return (_getValidatedTokenPrice(token), gasPrice.value);
+  ) external view returns (uint224 tokenPrice, uint224 gasPriceValue) {
+    if (!s_destChainConfigs[destChainSelector].isEnabled) revert DestinationChainNotEnabled(destChainSelector);
+    return (
+      _getValidatedTokenPrice(token),
+      _getValidatedGasPrice(destChainSelector, s_destChainConfigs[destChainSelector].gasPriceStalenessThreshold)
+    );
   }
 
   /// @notice Convert a given token amount to target token amount.
@@ -374,6 +373,27 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
     return Internal.TimestampedPackedUint224({value: rebasedValue, timestamp: uint32(block.timestamp)});
   }
 
+  /// @dev Gets the fee token price and the gas price, both denominated in dollars.
+  /// @param destChainSelector The destination chain to get the gas price for.
+  /// @param gasPriceStalenessThreshold The amount of time a gas price can be stale before it is considered invalid.
+  /// @return gasPriceValue The price of gas in 1e18 dollars per base unit.
+  function _getValidatedGasPrice(
+    uint64 destChainSelector,
+    uint32 gasPriceStalenessThreshold
+  ) private view returns (uint224 gasPriceValue) {
+    Internal.TimestampedPackedUint224 memory gasPrice = s_usdPerUnitGasByDestChainSelector[destChainSelector];
+    // If the staleness threshold is 0, we consider the gas price to be always valid
+    if (gasPriceStalenessThreshold != 0) {
+      // We do allow a gas price of 0, but no stale or unset gas prices
+      uint256 timePassed = block.timestamp - gasPrice.timestamp;
+      if (timePassed > gasPriceStalenessThreshold) {
+        revert StaleGasPrice(destChainSelector, gasPriceStalenessThreshold, timePassed);
+      }
+    }
+
+    return gasPrice.value;
+  }
+
   // ================================================================
   // │                         Fee tokens                           │
   // ================================================================
@@ -507,7 +527,8 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
     _validateMessage(destChainConfig, message.data.length, numberOfTokens, message.receiver);
 
     // The below call asserts that feeToken is a supported token
-    (uint224 feeTokenPrice, uint224 packedGasPrice) = getTokenAndGasPrices(message.feeToken, destChainSelector);
+    uint224 feeTokenPrice = _getValidatedTokenPrice(message.feeToken);
+    uint224 packedGasPrice = _getValidatedGasPrice(destChainSelector, destChainConfig.gasPriceStalenessThreshold);
 
     // Calculate premiumFee in USD with 18 decimals precision first.
     // If message-only and no token transfers, a flat network fee is charged.
@@ -990,7 +1011,7 @@ contract FeeQuoter is AuthorizedCallers, IFeeQuoter, ITypeAndVersion, IReceiver,
     return StaticConfig({
       maxFeeJuelsPerMsg: i_maxFeeJuelsPerMsg,
       linkToken: i_linkToken,
-      stalenessThreshold: i_stalenessThreshold
+      tokenPriceStalenessThreshold: i_tokenPriceStalenessThreshold
     });
   }
 }

contracts/src/v0.8/ccip/FeeQuoter.sol

@@ -1,8 +1,6 @@
 // SPDX-License-Identifier: BUSL-1.1
 pragma solidity 0.8.24;
 
-import {IFeeQuoter} from "../../interfaces/IFeeQuoter.sol";
-
 import {KeystoneFeedsPermissionHandler} from "../../../keystone/KeystoneFeedsPermissionHandler.sol";
 import {AuthorizedCallers} from "../../../shared/access/AuthorizedCallers.sol";
 import {MockV3Aggregator} from "../../../tests/MockV3Aggregator.sol";
@@ -35,7 +33,7 @@ contract FeeQuoter_constructor is FeeQuoterSetup {
     FeeQuoter.StaticConfig memory staticConfig = FeeQuoter.StaticConfig({
       linkToken: s_sourceTokens[0],
       maxFeeJuelsPerMsg: MAX_MSG_FEES_JUELS,
-      stalenessThreshold: uint32(TWELVE_HOURS)
+      tokenPriceStalenessThreshold: uint32(TWELVE_HOURS)
     });
     s_feeQuoter = new FeeQuoterHelper(
       staticConfig,
@@ -93,7 +91,7 @@ contract FeeQuoter_constructor is FeeQuoterSetup {
     FeeQuoter.StaticConfig memory staticConfig = FeeQuoter.StaticConfig({
       linkToken: s_sourceTokens[0],
       maxFeeJuelsPerMsg: MAX_MSG_FEES_JUELS,
-      stalenessThreshold: 0
+      tokenPriceStalenessThreshold: 0
     });
 
     vm.expectRevert(FeeQuoter.InvalidStaticConfig.selector);
@@ -113,7 +111,7 @@ contract FeeQuoter_constructor is FeeQuoterSetup {
     FeeQuoter.StaticConfig memory staticConfig = FeeQuoter.StaticConfig({
       linkToken: address(0),
       maxFeeJuelsPerMsg: MAX_MSG_FEES_JUELS,
-      stalenessThreshold: uint32(TWELVE_HOURS)
+      tokenPriceStalenessThreshold: uint32(TWELVE_HOURS)
     });
 
     vm.expectRevert(FeeQuoter.InvalidStaticConfig.selector);
@@ -133,7 +131,7 @@ contract FeeQuoter_constructor is FeeQuoterSetup {
     FeeQuoter.StaticConfig memory staticConfig = FeeQuoter.StaticConfig({
       linkToken: s_sourceTokens[0],
       maxFeeJuelsPerMsg: 0,
-      stalenessThreshold: uint32(TWELVE_HOURS)
+      tokenPriceStalenessThreshold: uint32(TWELVE_HOURS)
     });
 
     vm.expectRevert(FeeQuoter.InvalidStaticConfig.selector);
@@ -173,7 +171,7 @@ contract FeeQuoter_getTokenPrice is FeeQuoterSetup {
     uint256 originalTimestampValue = block.timestamp;
 
     // Above staleness threshold
-    vm.warp(originalTimestampValue + s_feeQuoter.getStaticConfig().stalenessThreshold + 1);
+    vm.warp(originalTimestampValue + s_feeQuoter.getStaticConfig().tokenPriceStalenessThreshold + 1);
 
     address sourceToken = _initialiseSingleTokenPriceFeed();
     Internal.TimestampedPackedUint224 memory tokenPriceAnswer = s_feeQuoter.getTokenPrice(sourceToken);
@@ -596,8 +594,35 @@ contract FeeQuoter_getTokenAndGasPrices is FeeQuoterSetup {
     assertEq(gasPrice, priceUpdates.gasPriceUpdates[0].usdPerUnitGas);
   }
 
+  function test_StalenessCheckDisabled_Success() public {
+    uint64 neverStaleChainSelector = 345678;
+    FeeQuoter.DestChainConfigArgs[] memory destChainConfigArgs = _generateFeeQuoterDestChainConfigArgs();
+    destChainConfigArgs[0].destChainSelector = neverStaleChainSelector;
+    destChainConfigArgs[0].destChainConfig.gasPriceStalenessThreshold = 0; // disables the staleness check
+
+    s_feeQuoter.applyDestChainConfigUpdates(destChainConfigArgs);
+
+    Internal.GasPriceUpdate[] memory gasPriceUpdates = new Internal.GasPriceUpdate[](1);
+    gasPriceUpdates[0] = Internal.GasPriceUpdate({destChainSelector: neverStaleChainSelector, usdPerUnitGas: 999});
+
+    Internal.PriceUpdates memory priceUpdates =
+      Internal.PriceUpdates({tokenPriceUpdates: new Internal.TokenPriceUpdate[](0), gasPriceUpdates: gasPriceUpdates});
+    s_feeQuoter.updatePrices(priceUpdates);
+
+    // this should have no affect! But we do it anyway to make sure the staleness check is disabled
+    vm.warp(block.timestamp + 52_000_000 weeks); // 1M-ish years
+
+    (, uint224 gasPrice) = s_feeQuoter.getTokenAndGasPrices(s_sourceFeeToken, neverStaleChainSelector);
+
+    assertEq(gasPrice, 999);
+  }
+
   function test_ZeroGasPrice_Success() public {
     uint64 zeroGasDestChainSelector = 345678;
+    FeeQuoter.DestChainConfigArgs[] memory destChainConfigArgs = _generateFeeQuoterDestChainConfigArgs();
+    destChainConfigArgs[0].destChainSelector = zeroGasDestChainSelector;
+
+    s_feeQuoter.applyDestChainConfigUpdates(destChainConfigArgs);
     Internal.GasPriceUpdate[] memory gasPriceUpdates = new Internal.GasPriceUpdate[](1);
     gasPriceUpdates[0] = Internal.GasPriceUpdate({destChainSelector: zeroGasDestChainSelector, usdPerUnitGas: 0});
 
@@ -607,11 +632,11 @@ contract FeeQuoter_getTokenAndGasPrices is FeeQuoterSetup {
 
     (, uint224 gasPrice) = s_feeQuoter.getTokenAndGasPrices(s_sourceFeeToken, zeroGasDestChainSelector);
 
-    assertEq(gasPrice, priceUpdates.gasPriceUpdates[0].usdPerUnitGas);
+    assertEq(gasPrice, 0);
   }
 
   function test_UnsupportedChain_Revert() public {
-    vm.expectRevert(abi.encodeWithSelector(FeeQuoter.ChainNotSupported.selector, DEST_CHAIN_SELECTOR + 1));
+    vm.expectRevert(abi.encodeWithSelector(FeeQuoter.DestinationChainNotEnabled.selector, DEST_CHAIN_SELECTOR + 1));
     s_feeQuoter.getTokenAndGasPrices(s_sourceTokens[0], DEST_CHAIN_SELECTOR + 1);
   }
 

contracts/src/v0.8/ccip/test/feeQuoter/FeeQuoter.t.sol

@@ -162,7 +162,7 @@ contract FeeQuoterSetup is TokenSetup {
       FeeQuoter.StaticConfig({
         linkToken: s_sourceTokens[0],
         maxFeeJuelsPerMsg: MAX_MSG_FEES_JUELS,
-        stalenessThreshold: uint32(TWELVE_HOURS)
+        tokenPriceStalenessThreshold: uint32(TWELVE_HOURS)
       }),
       priceUpdaters,
       feeTokens,
@@ -254,6 +254,7 @@ contract FeeQuoterSetup is TokenSetup {
         defaultTxGasLimit: GAS_LIMIT,
         gasMultiplierWeiPerEth: 5e17,
         networkFeeUSDCents: 1_00,
+        gasPriceStalenessThreshold: uint32(TWELVE_HOURS),
         enforceOutOfOrder: false,
         chainFamilySelector: Internal.CHAIN_FAMILY_SELECTOR_EVM
       })

contracts/src/v0.8/ccip/test/feeQuoter/FeeQuoterSetup.t.sol

@@ -73,9 +73,9 @@ func TestDeployAllV1_6(t *testing.T) {
 		owner,
 		chain,
 		fee_quoter.FeeQuoterStaticConfig{
-			MaxFeeJuelsPerMsg:  big.NewInt(1e18),
-			LinkToken:          common.HexToAddress("0x1"),
-			StalenessThreshold: 10,
+			MaxFeeJuelsPerMsg:            big.NewInt(1e18),
+			LinkToken:                    common.HexToAddress("0x1"),
+			TokenPriceStalenessThreshold: 10,
 		},
 		[]common.Address{common.HexToAddress("0x1")},
 		[]common.Address{common.HexToAddress("0x2")},

core/gethwrappers/ccip/deployment_test/deployment_test.go

@@ -13,7 +13,7 @@ commit_store_helper: ../../../contracts/solc/v0.8.24/CommitStoreHelper/CommitSto
 ether_sender_receiver: ../../../contracts/solc/v0.8.24/EtherSenderReceiver/EtherSenderReceiver.abi ../../../contracts/solc/v0.8.24/EtherSenderReceiver/EtherSenderReceiver.bin 09510a3f773f108a3c231e8d202835c845ded862d071ec54c4f89c12d868b8de
 evm_2_evm_offramp: ../../../contracts/solc/v0.8.24/EVM2EVMOffRamp/EVM2EVMOffRamp.abi ../../../contracts/solc/v0.8.24/EVM2EVMOffRamp/EVM2EVMOffRamp.bin b0d77babbe635cd6ba04c2af049badc9e9d28a4b6ed6bb75f830ad902a618beb
 evm_2_evm_onramp: ../../../contracts/solc/v0.8.24/EVM2EVMOnRamp/EVM2EVMOnRamp.abi ../../../contracts/solc/v0.8.24/EVM2EVMOnRamp/EVM2EVMOnRamp.bin 5c02c2b167946b3467636ff2bb58594cb4652fc63d8bdfee2488ed562e2a3e50
-fee_quoter: ../../../contracts/solc/v0.8.24/FeeQuoter/FeeQuoter.abi ../../../contracts/solc/v0.8.24/FeeQuoter/FeeQuoter.bin 6806f01f305df73a923361f128b8962e9a8d3e7338a9a5b5fbe0636e6c9fc35f
+fee_quoter: ../../../contracts/solc/v0.8.24/FeeQuoter/FeeQuoter.abi ../../../contracts/solc/v0.8.24/FeeQuoter/FeeQuoter.bin 503823a939ff99fe3bdaaef7a89cd4bbe475e260d3921335dbf9c80d4f584b76
 lock_release_token_pool: ../../../contracts/solc/v0.8.24/LockReleaseTokenPool/LockReleaseTokenPool.abi ../../../contracts/solc/v0.8.24/LockReleaseTokenPool/LockReleaseTokenPool.bin e6a8ec9e8faccb1da7d90e0f702ed72975964f97dc3222b54cfcca0a0ba3fea2
 lock_release_token_pool_and_proxy: ../../../contracts/solc/v0.8.24/LockReleaseTokenPoolAndProxy/LockReleaseTokenPoolAndProxy.abi ../../../contracts/solc/v0.8.24/LockReleaseTokenPoolAndProxy/LockReleaseTokenPoolAndProxy.bin e632b08be0fbd1d013e8b3a9d75293d0d532b83071c531ff2be1deec1fa48ec1
 maybe_revert_message_receiver: ../../../contracts/solc/v0.8.24/MaybeRevertMessageReceiver/MaybeRevertMessageReceiver.abi ../../../contracts/solc/v0.8.24/MaybeRevertMessageReceiver/MaybeRevertMessageReceiver.bin d73956c26232ebcc4a5444429fa99cbefed960e323be9b5a24925885c2e477d5