Transact from eth to sub

contracts/src/Gateway.sol

@@ -17,7 +17,9 @@ import {
     Command,
     MultiAddress,
     Ticket,
-    Costs
+    Costs,
+    TransactMessage,
+    OriginKind
 } from "./Types.sol";
 import {IGateway} from "./interfaces/IGateway.sol";
 import {IInitializable} from "./interfaces/IInitializable.sol";
@@ -27,6 +29,7 @@ import {SafeNativeTransfer} from "./utils/SafeTransfer.sol";
 import {Call} from "./utils/Call.sol";
 import {Math} from "./utils/Math.sol";
 import {ScaleCodec} from "./utils/ScaleCodec.sol";
+import {SubstrateTypes} from "./SubstrateTypes.sol";
 
 import {
     UpgradeParams,
@@ -86,6 +89,7 @@ contract Gateway is IGateway, IInitializable {
     error InvalidAgentExecutionPayload();
     error InvalidCodeHash();
     error InvalidConstructorParams();
+    error InvalidTransact();
 
     // handler functions are privileged
     modifier onlySelf() {
@@ -617,4 +621,31 @@ contract Gateway is IGateway, IInitializable {
         assets.assetHubCreateAssetFee = config.assetHubCreateAssetFee;
         assets.assetHubReserveTransferFee = config.assetHubReserveTransferFee;
     }
+
+    /// @inheritdoc IGateway
+    function transact(ParaID destinationChain, TransactMessage calldata message) external payable {
+        Ticket memory ticket;
+        Costs memory costs;
+        address sender;
+        bytes1 originKind;
+        // Mapping originKind to https://github.com/Snowfork/polkadot-sdk/blob/348a1a010481002e41594ed75e5d78b7c2dbed92/polkadot/xcm/src/v2/mod.rs#L86
+        // only support originKind as SovereignAccount or Xcm for now
+        // for Xcm the sender will be the agent of the channel which to construct `DescendOrigin` on BH
+        if (message.originKind == OriginKind.SovereignAccount) {
+            sender = msg.sender;
+            originKind = 0x01;
+        } else if (message.originKind == OriginKind.Xcm) {
+            Channel storage channel = _ensureChannel(destinationChain.into());
+            sender = channel.agent;
+            originKind = 0x03;
+            costs.foreign = message.fee;
+        } else {
+            revert InvalidTransact();
+        }
+        bytes memory payload = SubstrateTypes.Transact(sender, originKind, message);
+        ticket.dest = destinationChain;
+        ticket.costs = costs;
+        ticket.payload = payload;
+        _submitOutbound(ticket);
+    }
 }

contracts/src/SubstrateTypes.sol

@@ -3,7 +3,7 @@
 pragma solidity 0.8.23;
 
 import {ScaleCodec} from "./utils/ScaleCodec.sol";
-import {ParaID} from "./Types.sol";
+import {ParaID, TransactMessage, OriginKind} from "./Types.sol";
 
 /**
  * @title SCALE encoders for common Substrate types
@@ -133,4 +133,24 @@ library SubstrateTypes {
             ScaleCodec.encodeU128(xcmFee)
         );
     }
+
+    // Arbitrary transact
+    function Transact(address sender, bytes1 originKind, TransactMessage memory message)
+        internal
+        view
+        returns (bytes memory)
+    {
+        return bytes.concat(
+            bytes1(0x00),
+            ScaleCodec.encodeU64(uint64(block.chainid)),
+            bytes1(0x02),
+            SubstrateTypes.H160(sender),
+            originKind,
+            ScaleCodec.encodeU128(message.fee),
+            ScaleCodec.encodeU64(message.weightAtMost.refTime),
+            ScaleCodec.encodeU64(message.weightAtMost.proofSize),
+            ScaleCodec.checkedEncodeCompactU32(message.call.length),
+            message.call
+        );
+    }
 }

contracts/src/Types.sol

@@ -109,3 +109,20 @@ struct TokenInfo {
     bool isRegistered;
     bytes31 __padding;
 }
+
+struct Weight {
+    uint64 refTime;
+    uint64 proofSize;
+}
+
+enum OriginKind {
+    SovereignAccount,
+    Xcm
+}
+
+struct TransactMessage {
+    OriginKind originKind;
+    uint128 fee;
+    Weight weightAtMost;
+    bytes call;
+}

contracts/src/interfaces/IGateway.sol

@@ -2,7 +2,7 @@
 // SPDX-FileCopyrightText: 2023 Snowfork <[email protected]>
 pragma solidity 0.8.23;
 
-import {OperatingMode, InboundMessage, ParaID, ChannelID, MultiAddress} from "../Types.sol";
+import {OperatingMode, InboundMessage, ParaID, ChannelID, MultiAddress, TransactMessage} from "../Types.sol";
 import {Verification} from "../Verification.sol";
 import {UD60x18} from "prb/math/src/UD60x18.sol";
 
@@ -105,4 +105,7 @@ interface IGateway {
         uint128 destinationFee,
         uint128 amount
     ) external payable;
+
+    /// @dev Call transact in destinationChain
+    function transact(ParaID destinationChain, TransactMessage calldata message) external payable;
 }

contracts/test/Gateway.t.sol

@@ -42,22 +42,28 @@ import {
     ParaID,
     Command,
     multiAddressFromBytes32,
-    multiAddressFromBytes20
+    multiAddressFromBytes20,
+    TransactMessage,
+    Weight,
+    OriginKind
 } from "../src/Types.sol";
 
 import {WETH9} from "canonical-weth/WETH9.sol";
 import "./mocks/GatewayUpgradeMock.sol";
 import {UD60x18, ud60x18, convert} from "prb/math/src/UD60x18.sol";
 
 contract GatewayTest is Test {
-    ParaID public bridgeHubParaID = ParaID.wrap(1001);
-    bytes32 public bridgeHubAgentID = keccak256("1001");
+    ParaID public bridgeHubParaID = ParaID.wrap(1013);
+    bytes32 public bridgeHubAgentID = keccak256("1013");
     address public bridgeHubAgent;
 
-    ParaID public assetHubParaID = ParaID.wrap(1002);
-    bytes32 public assetHubAgentID = keccak256("1002");
+    ParaID public assetHubParaID = ParaID.wrap(1000);
+    bytes32 public assetHubAgentID = keccak256("1000");
     address public assetHubAgent;
 
+    ParaID public penpalParaID = ParaID.wrap(2000);
+    bytes32 public penpalAgentID = keccak256("2000");
+
     address public relayer;
 
     bytes32[] public proof = [bytes32(0x2f9ee6cfdf244060dc28aa46347c5219e303fc95062dd672b4e406ca5c29764b)];
@@ -114,6 +120,14 @@ contract GatewayTest is Test {
         bridgeHubAgent = IGateway(address(gateway)).agentOf(bridgeHubAgentID);
         assetHubAgent = IGateway(address(gateway)).agentOf(assetHubAgentID);
 
+        // Initialize agent/channel for Penpal
+        GatewayMock(address(gateway)).createAgentPublic(abi.encode(CreateAgentParams({agentID: penpalAgentID})));
+        GatewayMock(address(gateway)).createChannelPublic(
+            abi.encode(
+                CreateChannelParams({channelID: penpalParaID.into(), agentID: penpalAgentID, mode: OperatingMode.Normal})
+            )
+        );
+
         // fund the message relayer account
         relayer = makeAddr("relayer");
 
@@ -825,4 +839,29 @@ contract GatewayTest is Test {
         fee = IGateway(address(gateway)).quoteRegisterTokenFee();
         assertEq(fee, 10000000000000000);
     }
+
+    /**
+     * Transact
+     */
+    function testTransactFromSovereignOrigin() public {
+        TransactMessage memory message = TransactMessage(OriginKind.Xcm, 1, Weight(1, 1), bytes("0x1"));
+        address agentAddress = IGateway(address(gateway)).agentOf(penpalAgentID);
+        bytes memory payload = SubstrateTypes.Transact(agentAddress, 0x03, message);
+        console.log(agentAddress);
+        console.logBytes(payload);
+        vm.expectEmit(true, false, false, true);
+        emit IGateway.OutboundMessageAccepted(penpalParaID.into(), 1, messageID, payload);
+        IGateway(address(gateway)).transact{value: 1 ether}(penpalParaID, message);
+    }
+
+    function testTransactFromSignedOrigin() public {
+        TransactMessage memory message = TransactMessage(OriginKind.SovereignAccount, 1, Weight(1, 1), bytes("0x1"));
+        bytes memory payload = SubstrateTypes.Transact(account1, 0x01, message);
+        console.log(account1);
+        console.logBytes(payload);
+        vm.expectEmit(true, false, false, true);
+        emit IGateway.OutboundMessageAccepted(penpalParaID.into(), 1, messageID, payload);
+        hoax(address(account1));
+        IGateway(address(gateway)).transact{value: 1 ether}(penpalParaID, message);
+    }
 }

contracts/test/mocks/GatewayUpgradeMock.sol

@@ -2,7 +2,16 @@
 // SPDX-FileCopyrightText: 2023 Snowfork <[email protected]>
 pragma solidity 0.8.23;
 
-import {Channel, InboundMessage, OperatingMode, ParaID, Command, ChannelID, MultiAddress} from "../../src/Types.sol";
+import {
+    Channel,
+    InboundMessage,
+    OperatingMode,
+    ParaID,
+    Command,
+    ChannelID,
+    MultiAddress,
+    TransactMessage
+} from "../../src/Types.sol";
 import {IGateway} from "../../src/interfaces/IGateway.sol";
 import {IInitializable} from "../../src/interfaces/IInitializable.sol";
 import {Verification} from "../../src/Verification.sol";
@@ -61,4 +70,6 @@ contract GatewayUpgradeMock is IGateway, IInitializable {
     function pricingParameters() external pure returns (UD60x18, uint128) {
         return (convert(0), uint128(0));
     }
+
+    function transact(ParaID destinationChain, TransactMessage calldata message) external payable {}
 }