Direct XCM ExportMessage fees for different bridges to different receiver accounts (#2021)

polkadot/xcm/xcm-executor/src/lib.rs

@@ -248,7 +248,7 @@ impl<Config: config::Config> ExecuteXcm<Config::RuntimeCall> for XcmExecutor<Con
 			for asset in fees.inner() {
 				Config::AssetTransactor::withdraw_asset(&asset, &origin, None)?;
 			}
-			Config::FeeManager::handle_fee(fees, None);
+			Config::FeeManager::handle_fee(fees, None, FeeReason::ChargeFees);
 		}
 		Ok(())
 	}
@@ -851,7 +851,7 @@ impl<Config: config::Config> XcmExecutor<Config> {
 					destination,
 					xcm,
 				)?;
-				self.take_fee(fee, FeeReason::Export(network))?;
+				self.take_fee(fee, FeeReason::Export { network, destination })?;
 				Config::MessageExporter::deliver(ticket)?;
 				Ok(())
 			},
@@ -962,7 +962,7 @@ impl<Config: config::Config> XcmExecutor<Config> {
 		} else {
 			self.holding.try_take(fee.into()).map_err(|_| XcmError::NotHoldingFees)?.into()
 		};
-		Config::FeeManager::handle_fee(paid, Some(&self.context));
+		Config::FeeManager::handle_fee(paid, Some(&self.context), reason);
 		Ok(())
 	}
 

polkadot/xcm/xcm-executor/src/traits/fee_manager.rs

@@ -18,12 +18,12 @@ use xcm::prelude::*;
 
 /// Handle stuff to do with taking fees in certain XCM instructions.
 pub trait FeeManager {
-	/// Determine if a fee which would normally payable should be waived.
+	/// Determine if a fee should be waived.
 	fn is_waived(origin: Option<&MultiLocation>, r: FeeReason) -> bool;
 
 	/// Do something with the fee which has been paid. Doing nothing here silently burns the
 	/// fees.
-	fn handle_fee(fee: MultiAssets, context: Option<&XcmContext>);
+	fn handle_fee(fee: MultiAssets, context: Option<&XcmContext>, r: FeeReason);
 }
 
 /// Context under which a fee is paid.
@@ -42,7 +42,7 @@ pub enum FeeReason {
 	/// When the `QueryPallet` instruction is called.
 	QueryPallet,
 	/// When the `ExportMessage` instruction is called (and includes the network ID).
-	Export(NetworkId),
+	Export { network: NetworkId, destination: InteriorMultiLocation },
 	/// The `charge_fees` API.
 	ChargeFees,
 	/// When the `LockAsset` instruction is called.
@@ -55,5 +55,6 @@ impl FeeManager for () {
 	fn is_waived(_: Option<&MultiLocation>, _: FeeReason) -> bool {
 		false
 	}
-	fn handle_fee(_: MultiAssets, _: Option<&XcmContext>) {}
+
+	fn handle_fee(_: MultiAssets, _: Option<&XcmContext>, _: FeeReason) {}
 }