ibc: async acknowledgements

proto/ibc/lightclients/solomachine/v1/solomachine.proto

@@ -28,7 +28,7 @@ message ClientState {
 message ConsensusState {
   option (gogoproto.goproto_getters) = false;
   // public key of the solo machine
-   google.protobuf.Any public_key = 1 [(gogoproto.moretags) = "yaml:\"public_key\""];
+  google.protobuf.Any public_key = 1 [(gogoproto.moretags) = "yaml:\"public_key\""];
   // diversifier allows the same public key to be re-used across different solo machine clients
   // (potentially on different chains) without being considered misbehaviour.
   string diversifier = 2;
@@ -39,11 +39,11 @@ message ConsensusState {
 message Header {
   option (gogoproto.goproto_getters) = false;
   // sequence to update solo machine public key at
-  uint64                               sequence        = 1;
-  uint64                               timestamp       = 2;
-  bytes                                signature       = 3;
+  uint64              sequence        = 1;
+  uint64              timestamp       = 2;
+  bytes               signature       = 3;
   google.protobuf.Any new_public_key  = 4 [(gogoproto.moretags) = "yaml:\"new_public_key\""];
-  string                               new_diversifier = 5 [(gogoproto.moretags) = "yaml:\"new_diversifier\""];
+  string              new_diversifier = 5 [(gogoproto.moretags) = "yaml:\"new_diversifier\""];
 }
 
 // Misbehaviour defines misbehaviour for a solo machine which consists
@@ -143,7 +143,7 @@ message PacketAcknowledgementData {
   bytes acknowledgement = 2;
 }
 
-// PacketAcknowledgementAbsenceSignBytes returns the SignBytes data for
+// PacketReceiptAbsenceSignBytes returns the SignBytes data for
 // acknowledgement absence verification.
 message PacketAcknowledgementAbsenseData {
   bytes path = 1;

x/ibc-transfer/keeper/keeper.go

@@ -80,7 +80,7 @@ func (k Keeper) ReceiveExecuted(ctx sdk.Context, packet ibcexported.PacketI, ack
 	if !ok {
 		return sdkerrors.Wrap(channeltypes.ErrChannelCapabilityNotFound, "channel capability could not be retrieved for packet")
 	}
-	return k.channelKeeper.ReceiveExecuted(ctx, chanCap, packet, acknowledgement)
+	return k.channelKeeper.ReceiveExecuted(ctx, chanCap, packet)
 }
 
 // ChanCloseInit defines a wrapper function for the channel Keeper's function

x/ibc-transfer/types/expected_keepers.go

@@ -29,7 +29,8 @@ type ChannelKeeper interface {
 	GetChannel(ctx sdk.Context, srcPort, srcChan string) (channel channeltypes.Channel, found bool)
 	GetNextSequenceSend(ctx sdk.Context, portID, channelID string) (uint64, bool)
 	SendPacket(ctx sdk.Context, channelCap *capabilitytypes.Capability, packet ibcexported.PacketI) error
-	ReceiveExecuted(ctx sdk.Context, chanCap *capabilitytypes.Capability, packet ibcexported.PacketI, acknowledgement []byte) error
+	ReceiveExecuted(ctx sdk.Context, chanCap *capabilitytypes.Capability, packet ibcexported.PacketI) error
+	WriteAcknowledgement(ctx sdk.Context, packet ibcexported.PacketI, acknowledgement []byte) error
 	ChanCloseInit(ctx sdk.Context, portID, channelID string, chanCap *capabilitytypes.Capability) error
 }
 

x/ibc/02-client/types/errors.go

@@ -23,7 +23,7 @@ var (
 	ErrFailedChannelStateVerification         = sdkerrors.Register(SubModuleName, 16, "channel state verification failed")
 	ErrFailedPacketCommitmentVerification     = sdkerrors.Register(SubModuleName, 17, "packet commitment verification failed")
 	ErrFailedPacketAckVerification            = sdkerrors.Register(SubModuleName, 18, "packet acknowledgement verification failed")
-	ErrFailedPacketAckAbsenceVerification     = sdkerrors.Register(SubModuleName, 19, "packet acknowledgement absence verification failed")
+	ErrFailedPacketReceiptVerification        = sdkerrors.Register(SubModuleName, 19, "packet receipt verification failed")
 	ErrFailedNextSeqRecvVerification          = sdkerrors.Register(SubModuleName, 20, "next sequence receive verification failed")
 	ErrSelfConsensusStateNotFound             = sdkerrors.Register(SubModuleName, 21, "self consensus state not found")
 	ErrUpdateClientFailed                     = sdkerrors.Register(SubModuleName, 22, "unable to update light client")

x/ibc/03-connection/keeper/verify.go

@@ -175,10 +175,10 @@ func (k Keeper) VerifyPacketAcknowledgement(
 	return nil
 }
 
-// VerifyPacketAcknowledgementAbsence verifies a proof of the absence of an
+// VerifyPacketReceiptAbsence verifies a proof of the absence of an
 // incoming packet acknowledgement at the specified port, specified channel, and
 // specified sequence.
-func (k Keeper) VerifyPacketAcknowledgementAbsence(
+func (k Keeper) VerifyPacketReceiptAbsence(
 	ctx sdk.Context,
 	connection exported.ConnectionI,
 	height exported.Height,
@@ -192,7 +192,7 @@ func (k Keeper) VerifyPacketAcknowledgementAbsence(
 		return sdkerrors.Wrap(clienttypes.ErrClientNotFound, connection.GetClientID())
 	}
 
-	if err := clientState.VerifyPacketAcknowledgementAbsence(
+	if err := clientState.VerifyPacketReceiptAbsence(
 		k.clientKeeper.ClientStore(ctx, connection.GetClientID()), k.cdc, height,
 		connection.GetCounterparty().GetPrefix(), proof, portID, channelID,
 		sequence,

x/ibc/03-connection/keeper/verify_test.go

@@ -361,10 +361,10 @@ func (suite *KeeperTestSuite) TestVerifyPacketAcknowledgement() {
 	}
 }
 
-// TestVerifyPacketAcknowledgementAbsence has chainA verify the acknowledgement
+// TestVerifyPacketReceiptAbsence has chainA verify the acknowledgement
 // absence on channelB. The channels on chainA and chainB are fully opened and
 // a packet is sent from chainA to chainB and not received.
-func (suite *KeeperTestSuite) TestVerifyPacketAcknowledgementAbsence() {
+func (suite *KeeperTestSuite) TestVerifyPacketReceiptAbsence() {
 	cases := []struct {
 		msg            string
 		changeClientID bool
@@ -407,7 +407,7 @@ func (suite *KeeperTestSuite) TestVerifyPacketAcknowledgementAbsence() {
 			packetAckKey := host.KeyPacketAcknowledgement(packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence())
 			proof, proofHeight := suite.chainB.QueryProof(packetAckKey)
 
-			err = suite.chainA.App.IBCKeeper.ConnectionKeeper.VerifyPacketAcknowledgementAbsence(
+			err = suite.chainA.App.IBCKeeper.ConnectionKeeper.VerifyPacketReceiptAbsence(
 				suite.chainA.GetContext(), connection, malleateHeight(proofHeight, tc.heightDiff), proof,
 				packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence(),
 			)

x/ibc/04-channel/keeper/keeper.go

@@ -125,6 +125,23 @@ func (k Keeper) SetNextSequenceAck(ctx sdk.Context, portID, channelID string, se
 	store.Set(host.KeyNextSequenceAck(portID, channelID), bz)
 }
 
+// GetPacketReceipt gets a packet receipt from the store
+func (k Keeper) GetPacketReceipt(ctx sdk.Context, portID, channelID string, sequence uint64) (string, bool) {
+	store := ctx.KVStore(k.storeKey)
+	bz := store.Get(host.KeyPacketReceipt(portID, channelID, sequence))
+	if bz == nil {
+		return "", false
+	}
+
+	return string(bz), true
+}
+
+// SetPacketReceipt sets an empty packet receipt to the store
+func (k Keeper) SetPacketReceipt(ctx sdk.Context, portID, channelID string, sequence uint64) {
+	store := ctx.KVStore(k.storeKey)
+	store.Set(host.KeyPacketReceipt(portID, channelID, sequence), []byte(""))
+}
+
 // GetPacketCommitment gets the packet commitment hash from the store
 func (k Keeper) GetPacketCommitment(ctx sdk.Context, portID, channelID string, sequence uint64) []byte {
 	store := ctx.KVStore(k.storeKey)

x/ibc/04-channel/keeper/packet.go

@@ -15,6 +15,8 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/ibc/exported"
 )
 
+const emptyReceipt = ""
+
 // SendPacket is called by a module in order to send an IBC packet on a channel
 // end owned by the calling module to the corresponding module on the counterparty
 // chain.
@@ -242,15 +244,14 @@ func (k Keeper) RecvPacket(
 	return nil
 }
 
-// ReceiveExecuted writes the packet execution acknowledgement to the state,
-// which will be verified by the counterparty chain using AcknowledgePacket.
+// ReceiveExecuted updates the receive sequence in the case of an ordered channel or sets an empty receipt
+// if the channel is unordered.
 //
 // CONTRACT: this function must be called in the IBC handler
 func (k Keeper) ReceiveExecuted(
 	ctx sdk.Context,
 	chanCap *capabilitytypes.Capability,
 	packet exported.PacketI,
-	acknowledgement []byte,
 ) error {
 	channel, found := k.GetChannel(ctx, packet.GetDestPort(), packet.GetDestChannel())
 	if !found {
@@ -273,16 +274,6 @@ func (k Keeper) ReceiveExecuted(
 		)
 	}
 
-	if len(acknowledgement) == 0 {
-		return sdkerrors.Wrap(types.ErrInvalidAcknowledgement, "acknowledgement cannot be empty")
-	}
-
-	// always set the acknowledgement so that it can be verified on the other side
-	k.SetPacketAcknowledgement(
-		ctx, packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence(),
-		types.CommitAcknowledgement(acknowledgement),
-	)
-
 	if channel.Ordering == types.ORDERED {
 		nextSequenceRecv, found := k.GetNextSequenceRecv(ctx, packet.GetDestPort(), packet.GetDestChannel())
 		if !found {
@@ -297,17 +288,29 @@ func (k Keeper) ReceiveExecuted(
 		// incrementng nextSequenceRecv and storing under this chain's channelEnd identifiers
 		// Since this is the receiving chain, our channelEnd is packet's destination port and channel
 		k.SetNextSequenceRecv(ctx, packet.GetDestPort(), packet.GetDestChannel(), nextSequenceRecv)
+	} else {
+		// For unordered channels we must set the receipt so it can be verified on the other side.
+		// This receipt does not contain any data, since the packet has not yet been processed,
+		// it's just a single store key set to an empty string to indicate that the packet has been received
+		_, found := k.GetPacketReceipt(ctx, packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence())
+		if found {
+			return sdkerrors.Wrapf(
+				types.ErrPacketReceived,
+				"destination port: %s, destination channel: %s, sequence: %d", packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence(),
+			)
+		}
+
+		k.SetPacketReceipt(ctx, packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence())
 	}
 
 	// log that a packet has been received & executed
-	k.Logger(ctx).Info(fmt.Sprintf("packet received & executed: %v", packet))
+	k.Logger(ctx).Info("packet received and executed", "packet", fmt.Sprintf("%v", packet))
 
 	// emit an event that the relayer can query for
 	ctx.EventManager().EmitEvents(sdk.Events{
 		sdk.NewEvent(
 			types.EventTypeRecvPacket,
 			sdk.NewAttribute(types.AttributeKeyData, string(packet.GetData())),
-			sdk.NewAttribute(types.AttributeKeyAck, string(acknowledgement)),
 			sdk.NewAttribute(types.AttributeKeyTimeoutHeight, packet.GetTimeoutHeight().String()),
 			sdk.NewAttribute(types.AttributeKeyTimeoutTimestamp, fmt.Sprintf("%d", packet.GetTimeoutTimestamp())),
 			sdk.NewAttribute(types.AttributeKeySequence, fmt.Sprintf("%d", packet.GetSequence())),
@@ -326,6 +329,43 @@ func (k Keeper) ReceiveExecuted(
 	return nil
 }
 
+// WriteAcknowledgement writes the packet execution acknowledgement to the state,
+// which will be verified by the counterparty chain using AcknowledgePacket.
+//
+// CONTRACT: this function must be called in the IBC handler
+func (k Keeper) WriteAcknowledgement(
+	ctx sdk.Context,
+	packet exported.PacketI,
+	acknowledgement []byte,
+) error {
+	if len(acknowledgement) == 0 {
+		return sdkerrors.Wrap(types.ErrInvalidAcknowledgement, "acknowledgement cannot be empty")
+	}
+
+	// always set the acknowledgement so that it can be verified on the other side
+	k.SetPacketAcknowledgement(
+		ctx, packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence(),
+		types.CommitAcknowledgement(acknowledgement),
+	)
+
+	// log that a packet has been acknowledged
+	k.Logger(ctx).Info("packet acknowledged", "packet", fmt.Sprintf("%v", packet))
+
+	// emit an event that the relayer can query for
+	ctx.EventManager().EmitEvents(sdk.Events{
+		sdk.NewEvent(
+			types.EventTypeRecvPacket,
+			sdk.NewAttribute(types.AttributeKeyAck, string(acknowledgement)),
+		),
+		sdk.NewEvent(
+			sdk.EventTypeMessage,
+			sdk.NewAttribute(sdk.AttributeKeyModule, types.AttributeValueCategory),
+		),
+	})
+
+	return nil
+}
+
 // AcknowledgePacket is called by a module to process the acknowledgement of a
 // packet previously sent by the calling module on a channel to a counterparty
 // module on the counterparty chain. Its intended usage is within the ante

x/ibc/04-channel/keeper/packet_test.go

@@ -409,7 +409,7 @@ func (suite *KeeperTestSuite) TestReceiveExecuted() {
 
 			tc.malleate()
 
-			err := suite.chainB.App.IBCKeeper.ChannelKeeper.ReceiveExecuted(suite.chainB.GetContext(), channelCap, packet, ack)
+			err := suite.chainB.App.IBCKeeper.ChannelKeeper.ReceiveExecuted(suite.chainB.GetContext(), channelCap, packet)
 
 			if tc.expPass {
 				suite.Require().NoError(err)

x/ibc/04-channel/keeper/timeout.go

@@ -101,7 +101,7 @@ func (k Keeper) TimeoutPacket(
 			packet.GetDestPort(), packet.GetDestChannel(), nextSequenceRecv,
 		)
 	case types.UNORDERED:
-		err = k.connectionKeeper.VerifyPacketAcknowledgementAbsence(
+		err = k.connectionKeeper.VerifyPacketReceiptAbsence(
 			ctx, connectionEnd, proofHeight, proof,
 			packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence(),
 		)
@@ -255,7 +255,7 @@ func (k Keeper) TimeoutOnClose(
 			packet.GetDestPort(), packet.GetDestChannel(), nextSequenceRecv,
 		)
 	case types.UNORDERED:
-		err = k.connectionKeeper.VerifyPacketAcknowledgementAbsence(
+		err = k.connectionKeeper.VerifyPacketReceiptAbsence(
 			ctx, connectionEnd, proofHeight, proof,
 			packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence(),
 		)

x/ibc/04-channel/types/errors.go

@@ -23,4 +23,5 @@ var (
 	ErrAcknowledgementTooLong    = sdkerrors.Register(SubModuleName, 16, "acknowledgement too long")
 	ErrInvalidAcknowledgement    = sdkerrors.Register(SubModuleName, 17, "invalid acknowledgement")
 	ErrPacketCommitmentNotFound  = sdkerrors.Register(SubModuleName, 18, "packet commitment not found")
+	ErrPacketReceived            = sdkerrors.Register(SubModuleName, 19, "packet receipt already received")
 )

x/ibc/04-channel/types/expected_keepers.go

@@ -50,7 +50,7 @@ type ConnectionKeeper interface {
 		sequence uint64,
 		acknowledgement []byte,
 	) error
-	VerifyPacketAcknowledgementAbsence(
+	VerifyPacketReceiptAbsence(
 		ctx sdk.Context,
 		connection exported.ConnectionI,
 		height exported.Height,

x/ibc/07-tendermint/types/client_state.go

@@ -343,10 +343,10 @@ func (cs ClientState) VerifyPacketAcknowledgement(
 	return nil
 }
 
-// VerifyPacketAcknowledgementAbsence verifies a proof of the absence of an
+// VerifyPacketReceiptAbsence verifies a proof of the absence of an
 // incoming packet acknowledgement at the specified port, specified channel, and
 // specified sequence.
-func (cs ClientState) VerifyPacketAcknowledgementAbsence(
+func (cs ClientState) VerifyPacketReceiptAbsence(
 	store sdk.KVStore,
 	cdc codec.BinaryMarshaler,
 	height exported.Height,
@@ -361,7 +361,7 @@ func (cs ClientState) VerifyPacketAcknowledgementAbsence(
 		return err
 	}
 
-	path, err := commitmenttypes.ApplyPrefix(prefix, host.PacketAcknowledgementPath(portID, channelID, sequence))
+	path, err := commitmenttypes.ApplyPrefix(prefix, host.PacketReceiptPath(portID, channelID, sequence))
 	if err != nil {
 		return err
 	}

x/ibc/07-tendermint/types/client_state_test.go

@@ -495,7 +495,7 @@ func (suite *TendermintTestSuite) TestVerifyPacketAcknowledgement() {
 // test verification of the absent acknowledgement on chainB being represented
 // in the light client on chainA. A send from chainB to chainA is simulated, but
 // no receive.
-func (suite *TendermintTestSuite) TestVerifyPacketAcknowledgementAbsence() {
+func (suite *TendermintTestSuite) TestVerifyPacketReceiptAbsence() {
 	var (
 		clientState *types.ClientState
 		proof       []byte
@@ -565,7 +565,7 @@ func (suite *TendermintTestSuite) TestVerifyPacketAcknowledgementAbsence() {
 
 			store := suite.chainA.App.IBCKeeper.ClientKeeper.ClientStore(suite.chainA.GetContext(), clientA)
 
-			err = clientState.VerifyPacketAcknowledgementAbsence(
+			err = clientState.VerifyPacketReceiptAbsence(
 				store, suite.chainA.Codec, proofHeight, &prefix, proof,
 				packet.GetDestPort(), packet.GetDestChannel(), packet.GetSequence(),
 			)

x/ibc/09-localhost/types/client_state.go

@@ -257,10 +257,10 @@ func (cs ClientState) VerifyPacketAcknowledgement(
 	return nil
 }
 
-// VerifyPacketAcknowledgementAbsence verifies a proof of the absence of an
-// incoming packet acknowledgement at the specified port, specified channel, and
+// VerifyPacketReceiptAbsence verifies a proof of the absence of an
+// incoming packet receipt at the specified port, specified channel, and
 // specified sequence.
-func (cs ClientState) VerifyPacketAcknowledgementAbsence(
+func (cs ClientState) VerifyPacketReceiptAbsence(
 	store sdk.KVStore,
 	_ codec.BinaryMarshaler,
 	_ exported.Height,
@@ -270,11 +270,11 @@ func (cs ClientState) VerifyPacketAcknowledgementAbsence(
 	channelID string,
 	sequence uint64,
 ) error {
-	path := host.KeyPacketAcknowledgement(portID, channelID, sequence)
+	path := host.KeyPacketReceipt(portID, channelID, sequence)
 
 	data := store.Get(path)
 	if data != nil {
-		return sdkerrors.Wrap(clienttypes.ErrFailedPacketAckAbsenceVerification, "expected no ack absence")
+		return sdkerrors.Wrap(clienttypes.ErrFailedPacketReceiptVerification, "expected no packet receipt")
 	}
 
 	return nil

x/ibc/09-localhost/types/client_state_test.go

@@ -407,18 +407,18 @@ func (suite *LocalhostTestSuite) TestVerifyPacketAcknowledgement() {
 	}
 }
 
-func (suite *LocalhostTestSuite) TestVerifyPacketAcknowledgementAbsence() {
+func (suite *LocalhostTestSuite) TestVerifyPacketReceiptAbsence() {
 	clientState := types.NewClientState("chainID", clientHeight)
 
-	err := clientState.VerifyPacketAcknowledgementAbsence(
+	err := clientState.VerifyPacketReceiptAbsence(
 		suite.store, suite.cdc, clientHeight, nil, nil, testPortID, testChannelID, testSequence,
 	)
 
 	suite.Require().NoError(err, "ack absence failed")
 
 	suite.store.Set(host.KeyPacketAcknowledgement(testPortID, testChannelID, testSequence), []byte("ack"))
 
-	err = clientState.VerifyPacketAcknowledgementAbsence(
+	err = clientState.VerifyPacketReceiptAbsence(
 		suite.store, suite.cdc, clientHeight, nil, nil, testPortID, testChannelID, testSequence,
 	)
 	suite.Require().Error(err, "ack exists in store")