remove mw functionaity from uch

contracts/base/GeneralMiddleware.sol

@@ -18,7 +18,7 @@
 
 pragma solidity ^0.8.9;
 
 import {Ibc, UniversalPacket, AckPacket} from "../libs/Ibc.sol";
 import {IbcUtils} from "../libs/IbcUtils.sol";
 import {
     IbcUniversalPacketReceiver,
@@ -35,7 +35,7 @@
  *  @notice GeneralMiddleware is a starting point for developers to implement their own middleware logic. It is not
  * intended to be directly deployed, but rather only used for testing and development
  */
-contract GeneralMiddleware is IbcMwUser, IbcMiddleware, IbcMwEventsEmitter {
+contract GeneralMiddleware is IbcMwUser, IbcMiddleware, IbcMwEventsEmitter, IbcMwPacketSender {
     /**
      * @dev MW_ID is the ID of MW contract on all supported virtual chains.
      * MW_ID must:
@@ -45,7 +45,7 @@
      * one MW stack.
      * - be 1 << N, where N is a non-negative integer, and not in conflict with other MWs.
      */
     uint256 public MW_ID;
 
     event UCHPacketSent(address source, bytes32 destination);
     /**
@@ -63,7 +63,7 @@
         uint64 timeoutTimestamp
     ) external override {
         emit UCHPacketSent(msg.sender, destPortAddr);
         _sendPacket(channelId, IbcUtils.toBytes32(msg.sender), destPortAddr, 0, appData, timeoutTimestamp);
     }
 
     function sendMWPacket(
@@ -74,10 +74,10 @@
         bytes calldata appData,
         uint64 timeoutTimestamp
     ) external override {
         _sendPacket(channelId, srcPortAddr, destPortAddr, srcMwIds, appData, timeoutTimestamp);
     }
 
     function onRecvMWPacket(
         bytes32 channelId,
         UniversalPacket calldata ucPacket,
         // address srcPortAddr,
@@ -93,7 +93,7 @@
         // extra MW custom logic here to process packet, eg. emit MW events, mutate state, etc.
         // implementer can emit custom data fields suitable for their use cases.
         // Here we use MW_ID as the custom MW data field.
         emit RecvMWPacket(
             channelId, ucPacket.srcPortAddr, ucPacket.destPortAddr, MW_ID, ucPacket.appData, abi.encodePacked(MW_ID)
         );
 
@@ -122,7 +122,7 @@
         // extra MW custom logic here to process packet, eg. emit MW events, mutate state, etc.
         // implementer can emit custom data fields suitable for their use cases.
         // Here we use MW_ID as the custom MW data field.
         emit RecvMWAck(
             channelId,
             ucPacket.srcPortAddr,
             ucPacket.destPortAddr,
@@ -139,7 +139,7 @@
             );
         } else {
             // send ack to next MW
             IbcMwPacketReceiver(mwAddrs[mwIndex + 1]).onRecvMWAck(channelId, ucPacket, mwIndex + 1, mwAddrs, ack);
         }
     }
 
@@ -152,7 +152,7 @@
         // extra MW custom logic here to process packet, eg. emit MW events, mutate state, etc.
         // implementer can emit custom data fields suitable for their use cases.
         // Here we use MW_ID as the custom MW data field.
         emit RecvMWTimeout(
             channelId, ucPacket.srcPortAddr, ucPacket.destPortAddr, MW_ID, ucPacket.appData, abi.encodePacked(MW_ID)
         );
 
@@ -172,7 +172,7 @@
         override
         onlyIbcMw
         returns (AckPacket memory ackPacket)
     {}
 
     function onUniversalAcknowledgement(bytes32 channelId, UniversalPacket memory packet, AckPacket calldata ack)
         external

contracts/core/UniversalChannelHandler.sol

@@ -47,9 +47,6 @@ contract UniversalChannelHandler is IbcReceiverBaseUpgradeable, UUPSUpgradeable,
     string public constant VERSION = "1.0";
     uint256 public constant MW_ID = 1;
 
-    // Key: middleware bitmap, Value: middleware address from receiver(chain B)'s perspective
-    mapping(uint256 => address[]) public mwStackAddrs;
-
     event UCHPacketSent(address source, bytes32 destination);
 
     constructor() {
@@ -103,30 +100,6 @@ contract UniversalChannelHandler is IbcReceiverBaseUpgradeable, UUPSUpgradeable,
         dispatcher.sendPacket(channelId, packetData, timeoutTimestamp);
     }
 
-    /**
-     * @notice Sends a middleware packet over an IBC channel. This is intended to be called by another middleware
-     * contract, rather than an end Dapp itself.
-     * @param channelId The channel ID through which the packet is sent on the dispatcher
-     * @param destPortAddr The destination port address
-     * @param srcMwIds The mwId bitmap of the middleware stack
-     * @param appData The packet data to be sent
-     * @param timeoutTimestamp of when the packet can timeout
-     */
-    function sendMWPacket(
-        bytes32 channelId,
-        // original source address of the packet
-        bytes32 srcPortAddr,
-        bytes32 destPortAddr,
-        // source middleware ids bit AND
-        uint256 srcMwIds,
-        bytes calldata appData,
-        uint64 timeoutTimestamp
-    ) external {
-        bytes memory packetData =
-            IbcUtils.toUniversalPacketBytes(UniversalPacket(srcPortAddr, srcMwIds | MW_ID, destPortAddr, appData));
-        dispatcher.sendPacket(channelId, packetData, timeoutTimestamp);
-    }
-
     /**
      * @notice Handles the reception of an IBC packet from the counterparty
      * @param packet The received IBC packet
@@ -139,16 +112,10 @@ contract UniversalChannelHandler is IbcReceiverBaseUpgradeable, UUPSUpgradeable,
         returns (AckPacket memory ackPacket)
     {
         UniversalPacket memory ucPacket = IbcUtils.fromUniversalPacketBytes(packet.data);
-        address[] storage mwAddrs = mwStackAddrs[ucPacket.mwBitmap];
-        if (mwAddrs.length == 0) {
-            // no other middleware stack registered for this packet. Deliver packet to dApp directly.
-            return IbcUniversalPacketReceiver(IbcUtils.toAddress(ucPacket.destPortAddr)).onRecvUniversalPacket(
-                packet.dest.channelId, ucPacket
-            );
-        } else {
-            // send packet to first MW in the stack
-            return IbcMwPacketReceiver(mwAddrs[0]).onRecvMWPacket(packet.dest.channelId, ucPacket, 0, mwAddrs);
-        }
+        // no other middleware stack registered for this packet. Deliver packet to dApp directly.
+        return IbcUniversalPacketReceiver(IbcUtils.toAddress(ucPacket.destPortAddr)).onRecvUniversalPacket(
+            packet.dest.channelId, ucPacket
+        );
     }
 
     /**
@@ -162,16 +129,10 @@ contract UniversalChannelHandler is IbcReceiverBaseUpgradeable, UUPSUpgradeable,
         onlyIbcDispatcher
     {
         UniversalPacket memory ucPacket = IbcUtils.fromUniversalPacketBytes(packet.data);
-        address[] storage mwAddrs = mwStackAddrs[ucPacket.mwBitmap];
-        if (mwAddrs.length == 0) {
-            // no other middleware stack registered for this packet. Deliver ack to dApp directly.
-            IbcUniversalPacketReceiver(IbcUtils.toAddress(ucPacket.srcPortAddr)).onUniversalAcknowledgement(
-                packet.src.channelId, ucPacket, ack
-            );
-        } else {
-            // send ack to last MW in the stack
-            IbcMwPacketReceiver(mwAddrs[0]).onRecvMWAck(packet.src.channelId, ucPacket, 0, mwAddrs, ack);
-        }
+        // no other middleware stack registered for this packet. Deliver ack to dApp directly.
+        IbcUniversalPacketReceiver(IbcUtils.toAddress(ucPacket.srcPortAddr)).onUniversalAcknowledgement(
+            packet.src.channelId, ucPacket, ack
+        );
     }
 
     /**
@@ -180,29 +141,10 @@ contract UniversalChannelHandler is IbcReceiverBaseUpgradeable, UUPSUpgradeable,
      */
     function onTimeoutPacket(IbcPacket calldata packet) external override onlyIbcDispatcher {
         UniversalPacket memory ucPacketData = IbcUtils.fromUniversalPacketBytes(packet.data);
-        address[] storage mwAddrs = mwStackAddrs[ucPacketData.mwBitmap];
-        if (mwAddrs.length == 0) {
-            // no other middleware stack registered for this packet. Deliver timeout to dApp directly.
-            IbcUniversalPacketReceiver(IbcUtils.toAddress(ucPacketData.srcPortAddr)).onTimeoutUniversalPacket(
-                packet.src.channelId, ucPacketData
-            );
-        } else {
-            // send timeout to last MW in the stack
-            IbcMwPacketReceiver(mwAddrs[0]).onRecvMWTimeout(packet.src.channelId, ucPacketData, 0, mwAddrs);
-        }
-    }
-
-    /**
-     * @dev Register a middleware stack for universal packet routing.
-     * This is a temporary solution for testing only.
-     * Polymer chain will maintain a global registry of middleware stacks.
-     * @param mwBitmap Bit OR of all MW IDs in the stack, excluding this MW's ID
-     * @param mwAddrs addresses in the stack, from the perspective of the receiver (chain B)
-     * MW closer to UniversalChannel MW has smaller index. MW stack must be in the same order on both chains.
-     */
-    function registerMwStack(uint256 mwBitmap, address[] calldata mwAddrs) external onlyOwner {
-        if (mwBitmap == 0) revert MwBitmpaCannotBeZero();
-        mwStackAddrs[mwBitmap] = mwAddrs;
+        // no other middleware stack registered for this packet. Deliver timeout to dApp directly.
+        IbcUniversalPacketReceiver(IbcUtils.toAddress(ucPacketData.srcPortAddr)).onTimeoutUniversalPacket(
+            packet.src.channelId, ucPacketData
+        );
     }
 
     function onChanOpenConfirm(bytes32 channelId) external onlyIbcDispatcher {}

contracts/interfaces/IbcMiddleware.sol

@@ -99,7 +99,7 @@ interface IbcUniversalPacketReceiver {
     function onTimeoutUniversalPacket(bytes32 channelId, UniversalPacket calldata packet) external;
 }
 
-interface IbcMiddlwareProvider is IbcUniversalPacketSender, IbcMwPacketSender {
+interface IbcMiddlwareProvider is IbcUniversalPacketSender {
     /**
      * @dev MW_ID is the ID of MW contract on all supported virtual chains.
      * MW_ID must:

test/universal.channel.t.sol

@@ -210,12 +210,14 @@ contract UniversalChannelPacketTest is Base, IbcMwEventsEmitter {
 
     // packet flow: Earth -> MW1 -> UC -> Dispatcher -> (Relayer) -> Dispatcher -> UC -> MW1 -> Earth
     function test_packetFlow_via_mw1_ok() public {
+        vm.skip(true); // uch as middleware sender is not yet supported
         uint256 mwBitmap = register_mw1();
         verifyPacketFlow(5, mwBitmap);
     }
 
     // packet flow: Earth -> MW1 -> MW2 -> UC -> Dispatcher -> (Relayer) -> Dispatcher -> UC -> MW2 -> MW1 -> Earth
     function test_packetFlow_via_mw2_ok() public {
+        vm.skip(true); // uch as middleware sender is not yet supported
         uint256 mwBitmap = register_mw1_mw2();
         verifyPacketFlow(5, mwBitmap);
     }

test/upgradeableProxy/DispatcherRC4.upgrade.t.sol

@@ -172,19 +172,6 @@ contract DispatcherRC4MidwayUpgradeTest is ChannelHandShakeUpgradeUtil, UpgradeT
     IUniversalChannelHandler uch;
     LocalEnd _localUch;
     Earth earth;
-    uint256 mwBitmap;
-
-    GeneralMiddleware mw1;
-
-    event RecvMWPacket(
-        bytes32 indexed channelId,
-        bytes32 indexed srcPortAddr,
-        bytes32 indexed destPortAddr,
-        // middleware UID
-        uint256 mwId,
-        bytes appData,
-        bytes mwData
-    );
 
     function setUp() public override {
         ChannelHandshakeSetting memory setting = ChannelHandshakeSetting(ChannelOrder.ORDERED, false, true, validProof);
@@ -198,12 +185,6 @@ contract DispatcherRC4MidwayUpgradeTest is ChannelHandShakeUpgradeUtil, UpgradeT
         mars = new Mars(dispatcherProxy);
         uch = deployUCHV2ProxyAndImpl(address(dispatcherProxy));
         earth = new Earth(address(uch));
-        // Register mw stack and test it isn't corrupted after the upgrade
-        mw1 = new GeneralMiddleware(1 << 1, address(uch));
-        mwBitmap = uch.MW_ID() | mw1.MW_ID();
-        address[] memory mwAddrs = new address[](1);
-        mwAddrs[0] = address(mw1);
-        uch.registerMwStack(mwBitmap, mwAddrs);
         receivingMars = new Mars(dispatcherProxy);
 
         sendingPortId = IbcUtils.addressToPortId(portPrefix, address(mars));
@@ -222,7 +203,7 @@ contract DispatcherRC4MidwayUpgradeTest is ChannelHandShakeUpgradeUtil, UpgradeT
 
         channelOpenTry(_re, _le, setting, true);
 
-        // Do channel handshake via uch using mw set before the upgrade, to ensure that mw addrs state is still useful
+        // Do channel handshake via uch
         doProofChannelHandshake(_localUch, _remote);
         earth.greet(address(mars), _localUch.channelId, bytes("hello mars"), UINT64_MAX);
     }
@@ -279,10 +260,9 @@ contract DispatcherRC4MidwayUpgradeTest is ChannelHandShakeUpgradeUtil, UpgradeT
         assertEq(2, nextSequenceSendValue);
 
         // Now recv uch packet
-
         bytes memory appData = abi.encodePacked("hello using mw stack");
         UniversalPacket memory ucPacket =
-            UniversalPacket(IbcUtils.toBytes32(address(mars)), mwBitmap, IbcUtils.toBytes32(address(earth)), appData);
+            UniversalPacket(IbcUtils.toBytes32(address(mars)), uch.MW_ID(), IbcUtils.toBytes32(address(earth)), appData);
         bytes memory packetData = IbcUtils.toUniversalPacketBytes(ucPacket);
         IbcPacket memory uchPacket = IbcPacket(
             IbcEndpoint(sendingPortId, _local.channelId),
@@ -292,15 +272,14 @@ contract DispatcherRC4MidwayUpgradeTest is ChannelHandShakeUpgradeUtil, UpgradeT
             Height(0, 0),
             maxTimeout
         );
+
+        AckPacket memory earthAck = earth.generateAckPacket(0x0, address(mars), appData);
         vm.expectEmit(true, true, true, true);
-        emit RecvMWPacket(
-            _localUch.channelId,
-            ucPacket.srcPortAddr,
-            ucPacket.destPortAddr,
-            mw1.MW_ID(),
-            ucPacket.appData,
-            abi.encodePacked(mw1.MW_ID())
-        );
+        emit WriteAckPacket(address(uch), _localUch.channelId, 1, earthAck);
         dispatcherProxy.recvPacket(uchPacket, validProof);
+
+        (bytes32 actualChannelId, UniversalPacket memory storedUcPacket) = earth.recvedPackets(0);
+        assertEq(actualChannelId, _localUch.channelId);
+        assertEq(storedUcPacket.appData, ucPacket.appData);
     }
 }