chore: add channel consensus state rpc

modules/core/04-channel/v2/keeper/grpc_query.go

@@ -51,6 +51,38 @@ func (q *queryServer) Channel(ctx context.Context, req *types.QueryChannelReques
 	return types.NewQueryChannelResponse(channel), nil
 }
 
+// ChannelConsensusState implements the Query/ChannelConsensusState gRPC method
+func (q *queryServer) ChannelConsensusState(ctx context.Context, req *types.QueryChannelConsensusStateRequest) (*types.QueryChannelConsensusStateResponse, error) {
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "empty request")
+	}
+
+	if err := host.ChannelIdentifierValidator(req.ChannelId); err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	channel, found := q.GetChannel(ctx, req.ChannelId)
+	if !found {
+		return nil, status.Error(codes.NotFound, errorsmod.Wrapf(types.ErrChannelNotFound, "channel-id: %s", req.ChannelId).Error())
+	}
+
+	consHeight := clienttypes.NewHeight(req.RevisionNumber, req.RevisionHeight)
+	consensusState, found := q.ClientKeeper.GetClientConsensusState(ctx, channel.ClientId, consHeight)
+	if !found {
+		return nil, status.Error(
+			codes.NotFound,
+			errorsmod.Wrapf(clienttypes.ErrConsensusStateNotFound, "client-id: %s", channel.ClientId).Error(),
+		)
+	}
+
+	anyConsensusState, err := clienttypes.PackConsensusState(consensusState)
+	if err != nil {
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+
+	return types.NewQueryChannelConsensusStateResponse(channel.ClientId, anyConsensusState, nil, clienttypes.GetSelfHeight(ctx)), nil
+}
+
 // NextSequenceSend implements the Query/NextSequenceSend gRPC method
 func (q *queryServer) NextSequenceSend(ctx context.Context, req *types.QueryNextSequenceSendRequest) (*types.QueryNextSequenceSendResponse, error) {
 	if req == nil {

modules/core/04-channel/v2/types/expected_keepers.go

@@ -19,4 +19,6 @@ type ClientKeeper interface {
 	// GetClientTimestampAtHeight returns the timestamp for a given height on the client
 	// given its client ID and height
 	GetClientTimestampAtHeight(ctx context.Context, clientID string, height exported.Height) (uint64, error)
+	// GetClientConsensusState gets the stored consensus state from a client at a given height.
+	GetClientConsensusState(ctx context.Context, clientID string, height exported.Height) (exported.ConsensusState, bool)
 }

modules/core/04-channel/v2/types/query.go

@@ -1,6 +1,10 @@
 package types
 
-import clienttypes "github.com/cosmos/ibc-go/v9/modules/core/02-client/types"
+import (
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
+
+	clienttypes "github.com/cosmos/ibc-go/v9/modules/core/02-client/types"
+)
 
 // NewQueryChannelRequest creates and returns a new channel query request.
 func NewQueryChannelRequest(channelID string) *QueryChannelRequest {
@@ -16,6 +20,16 @@ func NewQueryChannelResponse(channel Channel) *QueryChannelResponse {
 	}
 }
 
+// NewQueryChannelConsensusStateResponse creates and returns a new ChannelConsensusState query response.
+func NewQueryChannelConsensusStateResponse(clientID string, anyConsensusState *codectypes.Any, proof []byte, height clienttypes.Height) *QueryChannelConsensusStateResponse {
+	return &QueryChannelConsensusStateResponse{
+		ConsensusState: anyConsensusState,
+		ClientId:       clientID,
+		Proof:          proof,
+		ProofHeight:    height,
+	}
+}
+
 // NewQueryNextSequenceSendRequest creates a new next sequence send query.
 func NewQueryNextSequenceSendRequest(channelID string) *QueryNextSequenceSendRequest {
 	return &QueryNextSequenceSendRequest{