Implement ADR 026

proto/ibc/client/client.proto

@@ -26,6 +26,21 @@ message ClientConsensusStates {
       [(gogoproto.moretags) = "yaml:\"consensus_states\""];
 }
 
+// ClientUpdateProposal is a governance proposal. If it passes, the client is
+// updated with the provided header. The update may fail if the header is not
+// valid given certain conditions specified by the client implementation.
+message ClientUpdateProposal {
+  option (gogoproto.goproto_getters) = false;
+  // the title of the update proposal
+  string title = 1;
+  // the description of the proposal
+  string description = 2;
+  // the client identifier for the client to be updated if the proposal passes
+  string client_id = 3 [(gogoproto.moretags) = "yaml:\"client_id\""];
+  // the header used to update the client if the proposal passes
+  google.protobuf.Any header = 4;
+}
+
 // MsgCreateClient defines a message to create an IBC client
 message MsgCreateClient {
   // client unique identifier

proto/ibc/tendermint/tendermint.proto

@@ -54,6 +54,16 @@ message ClientState {
   // Proof specifications used in verifying counterparty state
   repeated ics23.ProofSpec proof_specs = 8
       [(gogoproto.moretags) = "yaml:\"proof_specs\""];
+
+  // This flag, when set to true, will allow governance to recover a client
+  // which has expired
+  bool allow_update_after_expiry = 9
+      [(gogoproto.moretags) = "yaml:\"allow_update_after_expiry,omitempty\""];
+  // This flag, when set to true, will allow governance to unfreeze a client
+  // whose chain has experienced a misbehaviour event
+  bool allow_update_after_misbehaviour = 10
+      [(gogoproto.moretags) =
+           "yaml:\"allow_update_after_misbehaviour,omitempty\""];
 }
 
 // ConsensusState defines the consensus state from Tendermint.

simapp/app.go

@@ -52,6 +52,7 @@ import (
 	transfer "github.com/cosmos/cosmos-sdk/x/ibc-transfer"
 	ibctransferkeeper "github.com/cosmos/cosmos-sdk/x/ibc-transfer/keeper"
 	ibctransfertypes "github.com/cosmos/cosmos-sdk/x/ibc-transfer/types"
+	ibcclient "github.com/cosmos/cosmos-sdk/x/ibc/02-client"
 	porttypes "github.com/cosmos/cosmos-sdk/x/ibc/05-port/types"
 	ibchost "github.com/cosmos/cosmos-sdk/x/ibc/24-host"
 	ibckeeper "github.com/cosmos/cosmos-sdk/x/ibc/keeper"
@@ -244,17 +245,6 @@ func NewSimApp(
 	)
 	app.UpgradeKeeper = upgradekeeper.NewKeeper(skipUpgradeHeights, keys[upgradetypes.StoreKey], appCodec, homePath)
 
-	// register the proposal types
-	govRouter := govtypes.NewRouter()
-	govRouter.AddRoute(govtypes.RouterKey, govtypes.ProposalHandler).
-		AddRoute(paramproposal.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)).
-		AddRoute(distrtypes.RouterKey, distr.NewCommunityPoolSpendProposalHandler(app.DistrKeeper)).
-		AddRoute(upgradetypes.RouterKey, upgrade.NewSoftwareUpgradeProposalHandler(app.UpgradeKeeper))
-	app.GovKeeper = govkeeper.NewKeeper(
-		appCodec, keys[govtypes.StoreKey], app.GetSubspace(govtypes.ModuleName), app.AccountKeeper, app.BankKeeper,
-		&stakingKeeper, govRouter,
-	)
-
 	// register the staking hooks
 	// NOTE: stakingKeeper above is passed by reference, so that it will contain these hooks
 	app.StakingKeeper = *stakingKeeper.SetHooks(
@@ -266,6 +256,18 @@ func NewSimApp(
 		appCodec, keys[ibchost.StoreKey], app.StakingKeeper, scopedIBCKeeper,
 	)
 
+	// register the proposal types
+	govRouter := govtypes.NewRouter()
+	govRouter.AddRoute(govtypes.RouterKey, govtypes.ProposalHandler).
+		AddRoute(paramproposal.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)).
+		AddRoute(distrtypes.RouterKey, distr.NewCommunityPoolSpendProposalHandler(app.DistrKeeper)).
+		AddRoute(upgradetypes.RouterKey, upgrade.NewSoftwareUpgradeProposalHandler(app.UpgradeKeeper)).
+		AddRoute(ibchost.RouterKey, ibcclient.NewClientUpdateProposalHandler(app.IBCKeeper.ClientKeeper))
+	app.GovKeeper = govkeeper.NewKeeper(
+		appCodec, keys[govtypes.StoreKey], app.GetSubspace(govtypes.ModuleName), app.AccountKeeper, app.BankKeeper,
+		&stakingKeeper, govRouter,
+	)
+
 	// Create Transfer Keepers
 	app.TransferKeeper = ibctransferkeeper.NewKeeper(
 		appCodec, keys[ibctransfertypes.StoreKey], app.GetSubspace(ibctransfertypes.ModuleName),

x/ibc/02-client/handler.go

@@ -5,6 +5,7 @@ import (
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
 	"github.com/cosmos/cosmos-sdk/x/ibc/02-client/keeper"
 	"github.com/cosmos/cosmos-sdk/x/ibc/02-client/types"
 )
@@ -93,3 +94,16 @@ func HandleMsgSubmitMisbehaviour(ctx sdk.Context, k keeper.Keeper, msg *types.Ms
 		Events: ctx.EventManager().Events().ToABCIEvents(),
 	}, nil
 }
+
+// NewClientUpdateProposalHandler defines the client update proposal handler
+func NewClientUpdateProposalHandler(k keeper.Keeper) govtypes.Handler {
+	return func(ctx sdk.Context, content govtypes.Content) error {
+		switch c := content.(type) {
+		case *types.ClientUpdateProposal:
+			return k.ClientUpdateProposal(ctx, c)
+
+		default:
+			return sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "unrecognized ibc proposal content type: %T", c)
+		}
+	}
+}

x/ibc/02-client/handler_test.go

@@ -0,0 +1,76 @@
+package client_test
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	distributiontypes "github.com/cosmos/cosmos-sdk/x/distribution/types"
+	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
+	client "github.com/cosmos/cosmos-sdk/x/ibc/02-client"
+	clienttypes "github.com/cosmos/cosmos-sdk/x/ibc/02-client/types"
+	ibctmtypes "github.com/cosmos/cosmos-sdk/x/ibc/07-tendermint/types"
+	"github.com/cosmos/cosmos-sdk/x/ibc/exported"
+	ibctesting "github.com/cosmos/cosmos-sdk/x/ibc/testing"
+)
+
+func (suite *ClientTestSuite) TestNewClientUpdateProposalHandler() {
+	var (
+		content govtypes.Content
+		err     error
+	)
+
+	testCases := []struct {
+		name     string
+		malleate func()
+		expPass  bool
+	}{
+		{
+			"valid update client proposal", func() {
+				clientA, _ := suite.coordinator.SetupClients(suite.chainA, suite.chainB, exported.Tendermint)
+				clientState := suite.chainA.GetClientState(clientA)
+
+				tmClientState, ok := clientState.(*ibctmtypes.ClientState)
+				suite.Require().True(ok)
+				tmClientState.AllowUpdateAfterMisbehaviour = true
+				tmClientState.FrozenHeight = clienttypes.NewHeight(0, tmClientState.GetLatestHeight())
+				suite.chainA.App.IBCKeeper.ClientKeeper.SetClientState(suite.chainA.GetContext(), clientA, tmClientState)
+
+				// use next header for chainB to update the client on chainA
+				header, err := suite.chainA.ConstructUpdateTMClientHeader(suite.chainB, clientA)
+				suite.Require().NoError(err)
+
+				content, err = clienttypes.NewClientUpdateProposal(ibctesting.Title, ibctesting.Description, clientA, header)
+				suite.Require().NoError(err)
+			}, true,
+		},
+		{
+			"nil proposal", func() {
+				content = nil
+			}, false,
+		},
+		{
+			"unsupported proposal type", func() {
+				content = distributiontypes.NewCommunityPoolSpendProposal(ibctesting.Title, ibctesting.Description, suite.chainA.SenderAccount.GetAddress(), sdk.NewCoins(sdk.NewCoin("communityfunds", sdk.NewInt(10))))
+			}, false,
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+
+		suite.Run(tc.name, func() {
+			suite.SetupTest() // reset
+
+			tc.malleate()
+
+			proposalHandler := client.NewClientUpdateProposalHandler(suite.chainA.App.IBCKeeper.ClientKeeper)
+
+			err = proposalHandler(suite.chainA.GetContext(), content)
+
+			if tc.expPass {
+				suite.Require().NoError(err)
+			} else {
+				suite.Require().Error(err)
+			}
+		})
+	}
+
+}

x/ibc/02-client/keeper/client.go

@@ -37,7 +37,7 @@ func (k Keeper) CreateClient(
 	return clientState, nil
 }
 
-// UpdateClient updates the consensus state and the state root from a provided header
+// UpdateClient updates the consensus state and the state root from a provided header.
 func (k Keeper) UpdateClient(ctx sdk.Context, clientID string, header exported.Header) (exported.ClientState, error) {
 	clientType, found := k.GetClientType(ctx, clientID)
 	if !found {