Remove call index from the cross-chain interface

contracts/src/Assets.sol

@@ -95,17 +95,14 @@ library Assets {
 
     /// @dev Enqueues a create native token message to substrate.
     /// @param token The ERC20 token address.
-    function registerToken(address token, bytes2 createTokenCallID)
-        external
-        returns (bytes memory payload, uint256 extraFee)
-    {
+    function registerToken(address token) external returns (bytes memory payload, uint256 extraFee) {
         AssetsStorage.Layout storage $ = AssetsStorage.layout();
 
         if (!token.isContract()) {
             revert InvalidToken();
         }
 
-        payload = SubstrateTypes.RegisterToken(address(this), token, createTokenCallID);
+        payload = SubstrateTypes.RegisterToken(address(this), token);
         extraFee = $.registerTokenFee;
 
         emit TokenRegistrationSent(token);

contracts/src/DeployScript.sol

@@ -53,8 +53,7 @@ contract DeployScript is Script {
             bridgeHubParaID,
             bridgeHubAgentID,
             assetHubParaID,
-            assetHubAgentID,
-            bytes2(vm.envBytes("CREATE_CALL_INDEX"))
+            assetHubAgentID
         );
 
         bytes memory initParams = abi.encode(

contracts/src/Gateway.sol

@@ -40,7 +40,6 @@ contract Gateway is IGateway, IInitializable {
     // AssetHub
     ParaID internal immutable ASSET_HUB_PARA_ID;
     bytes32 internal immutable ASSET_HUB_AGENT_ID;
-    bytes2 internal immutable CREATE_TOKEN_CALL_ID;
 
     // Fixed amount of gas used outside the gas metering in submitInbound
     uint256 BASE_GAS_USED = 31000;
@@ -75,8 +74,7 @@ contract Gateway is IGateway, IInitializable {
         ParaID bridgeHubParaID,
         bytes32 bridgeHubAgentID,
         ParaID assetHubParaID,
-        bytes32 assetHubAgentID,
-        bytes2 createTokenCallID
+        bytes32 assetHubAgentID
     ) {
         if (
             bridgeHubParaID == ParaID.wrap(0) || bridgeHubAgentID == 0 || assetHubParaID == ParaID.wrap(0)
@@ -92,7 +90,6 @@ contract Gateway is IGateway, IInitializable {
         BRIDGE_HUB_AGENT_ID = bridgeHubAgentID;
         ASSET_HUB_PARA_ID = assetHubParaID;
         ASSET_HUB_AGENT_ID = assetHubAgentID;
-        CREATE_TOKEN_CALL_ID = createTokenCallID;
     }
 
     /// @dev Submit a message from Polkadot for verification and dispatch
@@ -418,7 +415,7 @@ contract Gateway is IGateway, IInitializable {
 
     // Register a token on AssetHub
     function registerToken(address token) external payable {
-        (bytes memory payload, uint256 extraFee) = Assets.registerToken(token, CREATE_TOKEN_CALL_ID);
+        (bytes memory payload, uint256 extraFee) = Assets.registerToken(token);
 
         _submitOutbound(ASSET_HUB_PARA_ID, payload, extraFee);
     }
@@ -528,7 +525,7 @@ contract Gateway is IGateway, IInitializable {
     }
 
     /// @dev Define the dust threshold as the minimum cost to transfer ether between accounts
-    function dustThreshold() view internal returns (uint256) {
+    function dustThreshold() internal view returns (uint256) {
         return 21000 * tx.gasprice;
     }
 

contracts/src/SubstrateTypes.sol

@@ -56,18 +56,13 @@ library SubstrateTypes {
      * `NativeTokensMessage::Create`
      */
     // solhint-disable-next-line func-name-mixedcase
-    function RegisterToken(address gateway, address token, bytes2 createCallIndex)
-        internal
-        view
-        returns (bytes memory)
-    {
+    function RegisterToken(address gateway, address token) internal view returns (bytes memory) {
         return bytes.concat(
             bytes1(0x00),
             ScaleCodec.encodeU64(uint64(block.chainid)),
             bytes1(0x00),
             SubstrateTypes.H160(gateway),
-            SubstrateTypes.H160(token),
-            createCallIndex
+            SubstrateTypes.H160(token)
         );
     }
 

contracts/test/Gateway.t.sol

@@ -79,8 +79,7 @@ contract GatewayTest is Test {
             bridgeHubParaID,
             bridgeHubAgentID,
             assetHubParaID,
-            assetHubAgentID,
-            bytes2(0x3500)
+            assetHubAgentID
         );
         gateway = new GatewayProxy(
             address(gatewayLogic),
@@ -158,7 +157,9 @@ contract GatewayTest is Test {
 
         hoax(relayer, 1 ether);
         IGateway(address(gateway)).submitInbound(
-            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward), proof, makeMockProof()
+            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward),
+            proof,
+            makeMockProof()
         );
     }
 
@@ -169,14 +170,18 @@ contract GatewayTest is Test {
 
         hoax(relayer, 1 ether);
         IGateway(address(gateway)).submitInbound(
-            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward), proof, makeMockProof()
+            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward),
+            proof,
+            makeMockProof()
         );
 
         // try to replay the message
         vm.expectRevert(Gateway.InvalidNonce.selector);
         hoax(relayer, 1 ether);
         IGateway(address(gateway)).submitInbound(
-            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward), proof, makeMockProof()
+            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward),
+            proof,
+            makeMockProof()
         );
     }
 
@@ -200,7 +205,9 @@ contract GatewayTest is Test {
 
         hoax(relayer, 1 ether);
         IGateway(address(gateway)).submitInbound(
-            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward), proof, makeMockProof()
+            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward),
+            proof,
+            makeMockProof()
         );
     }
 
@@ -221,7 +228,9 @@ contract GatewayTest is Test {
 
         uint256 startGas = gasleft();
         IGateway(address(gateway)).submitInbound(
-            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward), proof, makeMockProof()
+            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward),
+            proof,
+            makeMockProof()
         );
         uint256 endGas = gasleft();
         uint256 estimatedActualRefundAmount = (startGas - endGas) * tx.gasprice;
@@ -245,7 +254,9 @@ contract GatewayTest is Test {
 
         hoax(relayer, 1 ether);
         IGateway(address(gateway)).submitInbound(
-            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward), proof, makeMockProof()
+            InboundMessage(bridgeHubParaID, 1, command, params, maxDispatchGas, maxRefund, reward),
+            proof,
+            makeMockProof()
         );
 
         assertEq(address(bridgeHubAgent).balance, 0 ether);
@@ -525,9 +536,7 @@ contract GatewayTest is Test {
         emit TokenRegistrationSent(address(token));
 
         vm.expectEmit(true, false, false, false);
-        emit OutboundMessageAccepted(
-            assetHubParaID, 1, SubstrateTypes.RegisterToken(address(gateway), address(token), bytes2(0x3500))
-        );
+        emit OutboundMessageAccepted(assetHubParaID, 1, SubstrateTypes.RegisterToken(address(gateway), address(token)));
 
         IGateway(address(gateway)).registerToken{value: 2 ether}(address(token));
     }
@@ -537,9 +546,7 @@ contract GatewayTest is Test {
         emit TokenRegistrationSent(address(token));
 
         vm.expectEmit(true, false, false, false);
-        emit OutboundMessageAccepted(
-            assetHubParaID, 1, SubstrateTypes.RegisterToken(address(gateway), address(token), bytes2(0x3500))
-        );
+        emit OutboundMessageAccepted(assetHubParaID, 1, SubstrateTypes.RegisterToken(address(gateway), address(token)));
 
         uint256 totalFee = baseFee + registerNativeTokenFee;
         uint256 balanceBefore = address(this).balance;

contracts/test/mocks/GatewayMock.sol

@@ -15,19 +15,8 @@ contract GatewayMock is Gateway {
         ParaID bridgeHubParaID,
         bytes32 bridgeHubHubAgentID,
         ParaID assetHubParaID,
-        bytes32 assetHubHubAgentID,
-        bytes2 createTokenCallID
-    )
-        Gateway(
-            beefyClient,
-            agentExecutor,
-            bridgeHubParaID,
-            bridgeHubHubAgentID,
-            assetHubParaID,
-            assetHubHubAgentID,
-            createTokenCallID
-        )
-    {}
+        bytes32 assetHubHubAgentID
+    ) Gateway(beefyClient, agentExecutor, bridgeHubParaID, bridgeHubHubAgentID, assetHubParaID, assetHubHubAgentID) {}
 
     function agentExecutePublic(bytes calldata params) external {
         this.agentExecute(params);

parachain/pallets/control/src/lib.rs

@@ -240,6 +240,11 @@ pub mod pallet {
 		///
 		/// Fee required: Yes
 		///
+		/// This extrinsic is permissionless, so a fee is charged to prevent spamming and pay
+		/// for execution costs on the remote side.
+		///
+		/// The message is sent over the bridge on BridgeHub's own channel to the Gateway.
+		///
 		/// - `origin`: Must be `MultiLocation`
 		#[pallet::call_index(2)]
 		#[pallet::weight(T::WeightInfo::create_channel())]

parachain/pallets/inbound-queue/Cargo.toml

@@ -26,6 +26,7 @@ sp-io = { git = "https://github.com/paritytech/substrate.git", branch = "master"
 sp-runtime = { git = "https://github.com/paritytech/substrate.git", branch = "master", default-features = false }
 
 xcm = { git = "https://github.com/paritytech/polkadot.git", branch = "master", default-features = false }
+xcm-builder = { git = "https://github.com/paritytech/polkadot.git", branch = "master", default-features = false }
 bp-runtime = { git = "https://github.com/Snowfork/cumulus.git", branch = "snowbridge", default-features = false }
 
 snowbridge-core = { path = "../../primitives/core", default-features = false }
@@ -63,6 +64,7 @@ std = [
     "snowbridge-router-primitives/std",
     "ethabi/std",
     "xcm/std",
+    "xcm-builder/std",
     "bp-runtime/std",
 ]
 runtime-benchmarks = [
@@ -72,5 +74,6 @@ runtime-benchmarks = [
     "frame-system/runtime-benchmarks",
     "hex-literal",
     "rlp",
-    "snowbridge-beacon-primitives"
+    "snowbridge-beacon-primitives",
+    "xcm-builder/runtime-benchmarks",
 ]

parachain/pallets/inbound-queue/src/benchmarking/fixtures.rs

@@ -17,7 +17,7 @@ pub fn make_create_message() -> InboundQueueTest {
             receipts_root: hex!("a2686fe1aa2f66ada774373ced7952f3591a7830b9161eec5d16149747253779").into(),
         },
         message: Message {
-            data: hex!("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").to_vec(),
+            data: hex!("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").to_vec(),
             proof: Proof {
                 block_hash: hex!("565f5dc872af9351abd1ba4974753169a98f028ef2c2ef3bb6d4eea4c6519eac").into(),
                 tx_index: 0,

parachain/pallets/inbound-queue/src/lib.rs

@@ -28,15 +28,19 @@ use sp_core::H160;
 use sp_runtime::traits::AccountIdConversion;
 use sp_std::convert::TryFrom;
 use xcm::v3::{
-	send_xcm, Junction::*, Junctions::*, MultiLocation, SendError as XcmpSendError, XcmHash,
+	send_xcm, Junction::*, Junctions::*, MultiLocation, SendError as XcmpSendError, SendXcm,
+	XcmHash,
 };
 
 use envelope::Envelope;
 use snowbridge_core::{
 	inbound::{Message, Verifier},
 	ParaId,
 };
-use snowbridge_router_primitives::inbound;
+use snowbridge_router_primitives::{
+	inbound,
+	inbound::{ConvertMessage, ConvertMessageError},
+};
 pub use weights::WeightInfo;
 
 type BalanceOf<T> =
@@ -51,11 +55,9 @@ pub mod pallet {
 
 	use super::*;
 
+	use bp_runtime::{BasicOperatingMode, OwnedBridgeModule};
 	use frame_support::{pallet_prelude::*, traits::tokens::Preservation};
 	use frame_system::pallet_prelude::*;
-	use xcm::v3::SendXcm;
-
-	use bp_runtime::{BasicOperatingMode, OwnedBridgeModule};
 
 	#[pallet::pallet]
 	pub struct Pallet<T>(_);
@@ -87,6 +89,9 @@ pub mod pallet {
 		#[pallet::constant]
 		type GatewayAddress: Get<H160>;
 
+		/// Convert inbound message to XCM
+		type MessageConverter: ConvertMessage;
+
 		#[cfg(feature = "runtime-benchmarks")]
 		type Helper: BenchmarkHelper<Self>;
 	}
@@ -126,6 +131,8 @@ pub mod pallet {
 		Send(SendError),
 		/// Operational mode errors
 		OperationalMode(bp_runtime::OwnedBridgeModuleError),
+		/// Message conversion error
+		ConvertMessage(ConvertMessageError),
 	}
 
 	#[derive(Clone, Encode, Decode, Eq, PartialEq, Debug, TypeInfo, PalletError)]
@@ -218,7 +225,8 @@ pub mod pallet {
 
 			// Decode message into XCM
 			let xcm = match inbound::VersionedMessage::decode_all(&mut envelope.payload.as_ref()) {
-				Ok(inbound::VersionedMessage::V1(message_v1)) => message_v1.into(),
+				Ok(message) => T::MessageConverter::convert(message)
+					.map_err(|e| Error::<T>::ConvertMessage(e))?,
 				Err(_) => return Err(Error::<T>::InvalidPayload.into()),
 			};