chore: add channel client state rpc

modules/core/04-channel/v2/client/cli/abci.go

@@ -1,17 +1,46 @@
 package cli
 
 import (
+	"context"
 	"encoding/binary"
 
 	errorsmod "cosmossdk.io/errors"
 
 	"github.com/cosmos/cosmos-sdk/client"
 
+	clientutils "github.com/cosmos/ibc-go/v9/modules/core/02-client/client/utils"
+	clienttypes "github.com/cosmos/ibc-go/v9/modules/core/02-client/types"
 	"github.com/cosmos/ibc-go/v9/modules/core/04-channel/v2/types"
 	hostv2 "github.com/cosmos/ibc-go/v9/modules/core/24-host/v2"
 	ibcclient "github.com/cosmos/ibc-go/v9/modules/core/client"
 )
 
+func queryChannelClientStateABCI(clientCtx client.Context, channelID string) (*types.QueryChannelClientStateResponse, error) {
+	queryClient := types.NewQueryClient(clientCtx)
+	req := &types.QueryChannelClientStateRequest{
+		ChannelId: channelID,
+	}
+
+	res, err := queryClient.ChannelClientState(context.Background(), req)
+	if err != nil {
+		return nil, err
+	}
+
+	clientStateRes, err := clientutils.QueryClientStateABCI(clientCtx, res.IdentifiedClientState.ClientId)
+	if err != nil {
+		return nil, err
+	}
+
+	// use client state returned from ABCI query in case query height differs
+	identifiedClientState := clienttypes.IdentifiedClientState{
+		ClientId:    res.IdentifiedClientState.ClientId,
+		ClientState: clientStateRes.ClientState,
+	}
+	res = types.NewQueryChannelClientStateResponse(identifiedClientState, clientStateRes.Proof, clientStateRes.ProofHeight)
+
+	return res, nil
+}
+
 func queryNextSequenceSendABCI(clientCtx client.Context, channelID string) (*types.QueryNextSequenceSendResponse, error) {
 	key := hostv2.NextSequenceSendKey(channelID)
 	value, proofBz, proofHeight, err := ibcclient.QueryTendermintProof(clientCtx, key)

modules/core/04-channel/v2/client/cli/cli.go

@@ -20,6 +20,7 @@ func GetQueryCmd() *cobra.Command {
 
 	queryCmd.AddCommand(
 		getCmdQueryChannel(),
+		getCmdQueryChannelClientState(),
 		getCmdQueryNextSequenceSend(),
 		getCmdQueryPacketCommitment(),
 		getCmdQueryPacketCommitments(),

modules/core/04-channel/v2/client/cli/query.go

@@ -49,6 +49,51 @@ func getCmdQueryChannel() *cobra.Command {
 	return cmd
 }
 
+// getCmdQueryChannelClientState defines the command to query the channel client state for the given channel ID.
+func getCmdQueryChannelClientState() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "client-state [channel-id]",
+		Short:   "Query the client state associated with a channel.",
+		Long:    "Query the client state associated with a channel for the provided channel ID.",
+		Example: fmt.Sprintf("%s query %s %s client-state [channel-id]", version.AppName, exported.ModuleName, types.SubModuleName),
+		Args:    cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			clientCtx, err := client.GetClientQueryContext(cmd)
+			if err != nil {
+				return err
+			}
+
+			channelID := args[0]
+			prove, err := cmd.Flags().GetBool(flags.FlagProve)
+			if err != nil {
+				return err
+			}
+
+			if prove {
+				res, err := queryChannelClientStateABCI(clientCtx, channelID)
+				if err != nil {
+					return err
+				}
+
+				return clientCtx.PrintProto(res)
+			}
+
+			queryClient := types.NewQueryClient(clientCtx)
+			res, err := queryClient.ChannelClientState(cmd.Context(), types.NewQueryChannelClientStateRequest(channelID))
+			if err != nil {
+				return err
+			}
+
+			return clientCtx.PrintProto(res)
+		},
+	}
+
+	cmd.Flags().Bool(flags.FlagProve, true, "show proofs for the query results")
+	flags.AddQueryFlagsToCmd(cmd)
+
+	return cmd
+}
+
 // getCmdQueryNextSequenceSend defines the command to query a next send sequence for a given channel
 func getCmdQueryNextSequenceSend() *cobra.Command {
 	cmd := &cobra.Command{

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

@@ -51,6 +51,32 @@ func (q *queryServer) Channel(ctx context.Context, req *types.QueryChannelReques
 	return types.NewQueryChannelResponse(channel), nil
 }
 
+// ChannelClientState implements the Query/ChannelClientState gRPC method
+func (q *queryServer) ChannelClientState(ctx context.Context, req *types.QueryChannelClientStateRequest) (*types.QueryChannelClientStateResponse, 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())
+	}
+
+	clientState, found := q.ClientKeeper.GetClientState(ctx, channel.ClientId)
+	if !found {
+		return nil, status.Error(codes.NotFound, errorsmod.Wrapf(clienttypes.ErrClientNotFound, "channel-id: %s", req.ChannelId).Error())
+	}
+
+	identifiedClientState := clienttypes.NewIdentifiedClientState(channel.ClientId, clientState)
+	res := types.NewQueryChannelClientStateResponse(identifiedClientState, nil, clienttypes.GetSelfHeight(ctx))
+
+	return res, 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)
+	// GetClientState gets a particular client from the store
+	GetClientState(ctx context.Context, clientID string) (exported.ClientState, bool)
 }

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

@@ -16,6 +16,22 @@ func NewQueryChannelResponse(channel Channel) *QueryChannelResponse {
 	}
 }
 
+// NewQueryChannelClientStateRequest creates and returns a new ChannelClientState query request.
+func NewQueryChannelClientStateRequest(channelID string) *QueryChannelClientStateRequest {
+	return &QueryChannelClientStateRequest{
+		ChannelId: channelID,
+	}
+}
+
+// NewQueryChannelClientStateResponse creates and returns a new ChannelClientState query response.
+func NewQueryChannelClientStateResponse(identifiedClientState clienttypes.IdentifiedClientState, proof []byte, height clienttypes.Height) *QueryChannelClientStateResponse {
+	return &QueryChannelClientStateResponse{
+		IdentifiedClientState: &identifiedClientState,
+		Proof:                 proof,
+		ProofHeight:           height,
+	}
+}
+
 // NewQueryNextSequenceSendRequest creates a new next sequence send query.
 func NewQueryNextSequenceSendRequest(channelID string) *QueryNextSequenceSendRequest {
 	return &QueryNextSequenceSendRequest{