add UCH logging + new to/from UCHPacket encoding

contracts/base/GeneralMiddleware.sol

@@ -24,9 +24,11 @@ contract GeneralMiddleware is IbcMwUser, IbcMiddleware, IbcMwEventsEmitter {
      */
     uint256 public MW_ID;
 
+    event UCHPacketSent(address source, bytes32 destination);
     /**
      * @param _middleware The middleware contract address this contract sends packets to and receives packets from.
      */
+
     constructor(uint256 mwId, address _middleware) IbcMwUser(_middleware) {
         MW_ID = mwId;
     }
@@ -37,6 +39,7 @@ contract GeneralMiddleware is IbcMwUser, IbcMiddleware, IbcMwEventsEmitter {
         bytes calldata appData,
         uint64 timeoutTimestamp
     ) external override {
+        emit UCHPacketSent(msg.sender, destPortAddr);
         _sendPacket(channelId, IbcUtils.toBytes32(msg.sender), destPortAddr, 0, appData, timeoutTimestamp);
     }
 

contracts/core/UniversalChannelHandler.sol

@@ -22,6 +22,8 @@ contract UniversalChannelHandler is IbcReceiverBase, IbcUniversalChannelMW {
     // Key: middleware bitmap, Value: middleware address from receiver(chain B)'s perspective
     mapping(uint256 => address[]) public mwStackAddrs;
 
+    event UCHPacketSent(address source, bytes32 destination);
+
     constructor(IbcDispatcher _dispatcher) IbcReceiverBase(_dispatcher) {}
     /**
      * @dev Close a universal channel.
@@ -55,6 +57,7 @@ contract UniversalChannelHandler is IbcReceiverBase, IbcUniversalChannelMW {
         bytes memory packetData = IbcUtils.toUniversalPacketBytes(
             UniversalPacket(IbcUtils.toBytes32(msg.sender), MW_ID, destPortAddr, appData)
         );
+        emit UCHPacketSent(msg.sender, destPortAddr);
         dispatcher.sendPacket(channelId, packetData, timeoutTimestamp);
     }
 

contracts/libs/Ibc.sol

@@ -170,6 +170,27 @@ library IBCErrors {
 library IbcUtils {
     error StringTooLong();
 
+    // fromUniversalPacketBytes converts UniversalPacketDataBytes to UniversalPacketData, per how its packed into bytes
+    function fromUniversalPacketBytes(bytes calldata data)
+        external
+        pure
+        returns (UniversalPacket memory universalPacketData)
+    {
+        bytes32 srcPortAddr;
+        uint256 mwBitmap;
+        bytes32 destPortAddr;
+        assembly {
+            // Keep reusing 0x0 to move from calldata to return vars
+            calldatacopy(0x0, data.offset, 32)
+            srcPortAddr := mload(0x0)
+            calldatacopy(0x0, add(data.offset, 32), 32)
+            mwBitmap := mload(0x0)
+            calldatacopy(0x0, add(data.offset, 64), 32)
+            destPortAddr := mload(0x0)
+        }
+        universalPacketData = UniversalPacket(srcPortAddr, uint256(mwBitmap), destPortAddr, data[96:data.length]);
+    }
+
     /**
      * Convert a non-0x-prefixed hex string to an address
      * @param hexStr hex string to convert to address. Note that the hex string must not include a 0x prefix.
@@ -218,19 +239,8 @@ library IbcUtils {
         }
     }
 
-    // convert params to UniversalPacketBytes with optimal gas cost
-
     function toUniversalPacketBytes(UniversalPacket memory data) internal pure returns (bytes memory packetBytes) {
-        packetBytes = abi.encode(data);
-    }
-
-    // fromUniversalPacketBytes converts UniversalPacketDataBytes to UniversalPacketData, per how its packed into bytes
-    function fromUniversalPacketBytes(bytes memory data)
-        internal
-        pure
-        returns (UniversalPacket memory universalPacketData)
-    {
-        universalPacketData = abi.decode(data, (UniversalPacket));
+        packetBytes = bytes.concat(data.srcPortAddr, bytes32(data.mwBitmap), data.destPortAddr, data.appData);
     }
 
     // addressToPortId converts an address to a port ID

test/Ibc.t.sol

@@ -57,4 +57,33 @@ contract IbcTest is Test {
         assertFalse(parsederr.success);
         assertEq(bytes("this is an error message"), parsederr.data);
     }
+
+    function assert_Equal_Before_and_After_Encoding(address a1, uint256 mwBitmap, address a2, bytes memory appData)
+        internal
+    {
+        bytes memory afterEncoding = IbcUtils.toUniversalPacketBytes(
+            UniversalPacket(IbcUtils.toBytes32(a1), mwBitmap, IbcUtils.toBytes32(a2), appData)
+        );
+
+        UniversalPacket memory afterDecoding = IbcUtils.fromUniversalPacketBytes(afterEncoding);
+        assertEq(a1, IbcUtils.toAddress(afterDecoding.srcPortAddr));
+        assertEq(mwBitmap, afterDecoding.mwBitmap);
+        assertEq(a2, IbcUtils.toAddress(afterDecoding.destPortAddr));
+        assertEq(appData, afterDecoding.appData);
+    }
+
+    function test_To_From_UniversalPacketBytes() public {
+        // Standard
+        assert_Equal_Before_and_After_Encoding(vm.addr(1), uint256(123), vm.addr(2), "helloooo decode this for me ");
+        // empty string
+        assert_Equal_Before_and_After_Encoding(vm.addr(1), uint256(123), vm.addr(2), ""); // empty string
+
+        // Really long string:
+        assert_Equal_Before_and_After_Encoding(
+            vm.addr(1),
+            uint256(123),
+            vm.addr(2),
+            "daf;lkdsajflkasjdv;lkjzdljga;lkgfjda;iocjvz;lkjval;dsjkf;alkdj;zlkjv;lkjaeg;ijafd;lkjzvc,mnb.kahgd;ajkfaj;dgoij;zlckjv;lzkjv;kaldfjg;alkjgf;lkzvjcx;lkvja;lkjg;aslgjdz;adf;kasjg;lkjwaea;lkjg;io1j;4kjrda;lkfjaleot8ywp89yz;dvhlsdkj"
+        );
+    }
 }

test/universal.channel.t.sol

@@ -7,6 +7,7 @@ import {IbcEventsEmitter} from "../contracts/interfaces/IbcDispatcher.sol";
 import {IbcReceiver} from "../contracts/interfaces/IbcReceiver.sol";
 import "../contracts/core/UniversalChannelHandler.sol";
 import "../contracts/examples/Mars.sol";
+import "../contracts/interfaces/IbcMiddleware.sol";
 import "../contracts/core/OpLightClient.sol";
 import "./Dispatcher.base.t.sol";
 import "./VirtualChain.sol";
@@ -91,6 +92,8 @@ struct UcPacket {
 }
 
 contract UniversalChannelPacketTest is Base, IbcMwEventsEmitter {
+    event UCHPacketSent(address source, bytes32 destination);
+
     VirtualChain eth1;
     VirtualChain eth2;
     VirtualChainData v1;
@@ -239,6 +242,9 @@ contract UniversalChannelPacketTest is Base, IbcMwEventsEmitter {
                 IbcUtils.toBytes32(address(v1.earth)), mwBitmap, IbcUtils.toBytes32(address(v2.earth)), appData
             );
             packetData = IbcUtils.toUniversalPacketBytes(ucPacket);
+            // Verify event emitted by UCH
+            vm.expectEmit(true, true, true, true);
+            emit UCHPacketSent(address(v1.earth), IbcUtils.toBytes32(address(v2.earth)));
 
             // iterate over sending middleware contracts to verify each MW has witnessed the packet
             for (uint256 i = 0; i < senderMws.length; i++) {
@@ -258,6 +264,7 @@ contract UniversalChannelPacketTest is Base, IbcMwEventsEmitter {
             // Verify event emitted by Dispatcher
             vm.expectEmit(true, true, true, true);
             emit SendPacket(address(v1.ucHandler), channelId1, packetData, packetSeq, timeout);
+
             v1.earth.greet(address(v2.earth), channelId1, appData, timeout);
 
             // simulate relayer calling dispatcherProxy.recvPacket on chain B
@@ -325,6 +332,8 @@ contract UniversalChannelPacketTest is Base, IbcMwEventsEmitter {
                 IbcUtils.toBytes32(address(v1.earth)), mwBitmap, IbcUtils.toBytes32(address(v2.earth)), appData
             );
             packetData = IbcUtils.toUniversalPacketBytes(ucPacket);
+            vm.expectEmit(true, true, true, true);
+            emit UCHPacketSent(address(v1.earth), IbcUtils.toBytes32(address(v2.earth)));
 
             // iterate over sending middleware contracts to verify each MW has witnessed the packet
             for (uint256 i = 0; i < senderMws.length; i++) {
@@ -341,6 +350,7 @@ contract UniversalChannelPacketTest is Base, IbcMwEventsEmitter {
                     );
                 }
             }
+
             // Verify event emitted by Dispatcher
             vm.expectEmit(true, true, true, true);
             emit SendPacket(address(v1.ucHandler), channelId1, packetData, packetSeq, timeout);