Implement Channel Upgrade Try functionality for 04 channel

modules/apps/27-interchain-accounts/controller/ibc_middleware.go

@@ -246,8 +246,7 @@ func (im IBCMiddleware) OnChanUpgradeConfirm(ctx sdk.Context, portID, channelID
 }
 
 // OnChanUpgradeRestore implements the IBCModule interface
-func (im IBCMiddleware) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) error {
-	return nil
+func (im IBCMiddleware) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) {
 }
 
 // SendPacket implements the ICS4 Wrapper interface

modules/apps/27-interchain-accounts/host/ibc_module.go

@@ -170,6 +170,5 @@ func (im IBCModule) OnChanUpgradeConfirm(ctx sdk.Context, portID, channelID stri
 }
 
 // OnChanUpgradeRestore implements the IBCModule interface
-func (im IBCModule) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) error {
-	return nil
+func (im IBCModule) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) {
 }

modules/apps/29-fee/ibc_middleware.go

@@ -341,8 +341,8 @@ func (im IBCMiddleware) OnChanUpgradeConfirm(ctx sdk.Context, portID, channelID
 }
 
 // OnChanUpgradeRestore implements the IBCModule interface
-func (im IBCMiddleware) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) error {
-	return im.app.OnChanUpgradeRestore(ctx, portID, channelID)
+func (im IBCMiddleware) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) {
+	im.app.OnChanUpgradeRestore(ctx, portID, channelID)
 }
 
 // SendPacket implements the ICS4 Wrapper interface

modules/apps/transfer/ibc_module.go

@@ -322,6 +322,5 @@ func (im IBCModule) OnChanUpgradeConfirm(ctx sdk.Context, portID, channelID stri
 }
 
 // OnChanUpgradeRestore implements the IBCModule interface
-func (im IBCModule) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) error {
-	return nil
+func (im IBCModule) OnChanUpgradeRestore(ctx sdk.Context, portID, channelID string) {
 }

modules/core/04-channel/keeper/events.go

@@ -291,3 +291,23 @@ func emitChannelUpgradeInitEvent(ctx sdk.Context, portID string, channelID strin
 		),
 	})
 }
+
+// emitChannelUpgradeTryEvent emits a channel upgrade try event
+func emitChannelUpgradeTryEvent(ctx sdk.Context, portID string, channelID string, upgradeSequence uint64, channel types.Channel) {
+	ctx.EventManager().EmitEvents(sdk.Events{
+		sdk.NewEvent(
+			types.EventTypeChannelUpgradeTry,
+			sdk.NewAttribute(types.AttributeKeyPortID, portID),
+			sdk.NewAttribute(types.AttributeKeyChannelID, channelID),
+			sdk.NewAttribute(types.AttributeCounterpartyPortID, channel.Counterparty.PortId),
+			sdk.NewAttribute(types.AttributeCounterpartyChannelID, channel.Counterparty.ChannelId),
+			sdk.NewAttribute(types.AttributeKeyConnectionID, channel.ConnectionHops[0]),
+			sdk.NewAttribute(types.AttributeVersion, channel.Version),
+			sdk.NewAttribute(types.AttributeKeyUpgradeSequence, fmt.Sprintf("%d", upgradeSequence)),
+		),
+		sdk.NewEvent(
+			sdk.EventTypeMessage,
+			sdk.NewAttribute(sdk.AttributeKeyModule, types.AttributeValueCategory),
+		),
+	})
+}

modules/core/04-channel/keeper/upgrade.go

@@ -8,12 +8,14 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
 
+	"github.com/cosmos/ibc-go/v7/internal/collections"
 	clienttypes "github.com/cosmos/ibc-go/v7/modules/core/02-client/types"
 	connectiontypes "github.com/cosmos/ibc-go/v7/modules/core/03-connection/types"
 	"github.com/cosmos/ibc-go/v7/modules/core/04-channel/types"
 	portkeeper "github.com/cosmos/ibc-go/v7/modules/core/05-port/keeper"
 	porttypes "github.com/cosmos/ibc-go/v7/modules/core/05-port/types"
 	host "github.com/cosmos/ibc-go/v7/modules/core/24-host"
+	"github.com/cosmos/ibc-go/v7/modules/core/exported"
 )
 
 // ChanUpgradeInit is called by a module to initiate a channel upgrade handshake with
@@ -86,17 +88,249 @@ func (k Keeper) WriteUpgradeInitChannel(
 	channelID string,
 	upgradeSequence uint64,
 	channelUpgrade types.Channel,
-) {
+) error {
 	defer telemetry.IncrCounter(1, "ibc", "channel", "upgrade-init")
 
+	channel, found := k.GetChannel(ctx, portID, channelID)
+	if !found {
+		return errorsmod.Wrapf(types.ErrChannelNotFound, "failed to retrieve channel %s on port %s", channelID, portID)
+	}
+
+	// assign directly the fields that are modifiable.
+	// counterparty fields may not be changed.
+	channel.Version = channelUpgrade.Version
+	channel.Ordering = channelUpgrade.Ordering
+	channel.ConnectionHops = channelUpgrade.ConnectionHops
+
+	// prevent silent failures if fields that are not allowed to be modified are changed in the upgrade channel
+	// request.
+	if !reflect.DeepEqual(channel, channelUpgrade) {
+		return errorsmod.Wrapf(types.ErrInvalidChannel, "expected: %v but got: %v", channel, channelUpgrade)
+	}
+
 	k.SetChannel(ctx, portID, channelID, channelUpgrade)
 	k.Logger(ctx).Info("channel state updated", "port-id", portID, "channel-id", channelID, "previous-state", types.OPEN.String(), "new-state", types.INITUPGRADE.String())
 
 	emitChannelUpgradeInitEvent(ctx, portID, channelID, upgradeSequence, channelUpgrade)
+	return nil
+}
+
+// ChanUpgradeTry is called by a module to accept the first step of a channel upgrade
+// handshake initiated by a module on another chain.
+func (k Keeper) ChanUpgradeTry(
+	ctx sdk.Context,
+	portID string,
+	channelID string,
+	chanCap *capabilitytypes.Capability,
+	counterpartyChannel types.Channel,
+	counterpartyUpgradeSequence uint64,
+	proposedUpgradeChannel types.Channel,
+	timeoutHeight clienttypes.Height,
+	timeoutTimestamp uint64,
+	proofChannel []byte,
+	proofUpgradeTimeout []byte,
+	proofUpgradeSequence []byte,
+	proofHeight clienttypes.Height,
+) (upgradeSequence uint64, previousVersion string, err error) {
+	channel, found := k.GetChannel(ctx, portID, channelID)
+	if !found {
+		return 0, "", errorsmod.Wrapf(types.ErrChannelNotFound, "port ID (%s) channel ID (%s)", portID, channelID)
+	}
+
+	if !collections.Contains(channel.State, []types.State{types.OPEN, types.INITUPGRADE}) {
+		return 0, "", errorsmod.Wrapf(types.ErrInvalidChannelState, "expected one of [%s, %s], got %s", types.OPEN, types.INITUPGRADE, channel.State)
+	}
+
+	if !k.scopedKeeper.AuthenticateCapability(ctx, chanCap, host.ChannelCapabilityPath(portID, channelID)) {
+		return 0, "", errorsmod.Wrapf(types.ErrChannelCapabilityNotFound, "caller does not own capability for channel, port ID (%s) channel ID (%s)", portID, channelID)
+	}
+
+	if proposedUpgradeChannel.Counterparty.PortId != channel.Counterparty.PortId ||
+		proposedUpgradeChannel.Counterparty.ChannelId != channel.Counterparty.ChannelId {
+		return 0, "", errorsmod.Wrap(types.ErrInvalidChannel, "proposed channel upgrade is invalid")
+	}
+
+	if !channel.Ordering.SubsetOf(proposedUpgradeChannel.Ordering) {
+		return 0, "", errorsmod.Wrap(types.ErrInvalidChannelOrdering, "channel ordering must be a subset of the new ordering")
+	}
+
+	if counterpartyChannel.Ordering != proposedUpgradeChannel.Ordering {
+		return 0, "", errorsmod.Wrapf(types.ErrInvalidChannelOrdering, "channel ordering of counterparty channel and proposed channel must be equal")
+	}
+
+	connectionEnd, err := k.getUpgradeTryConnectionEnd(ctx, portID, channelID, channel)
+	if err != nil {
+		return 0, "", err
+	}
+
+	if connectionEnd.GetState() != int32(connectiontypes.OPEN) {
+		return 0, "", errorsmod.Wrapf(
+			connectiontypes.ErrInvalidConnectionState,
+			"connection state is not OPEN (got %s)", connectiontypes.State(connectionEnd.GetState()).String(),
+		)
+	}
+
+	if connectionEnd.GetCounterparty().GetConnectionID() != counterpartyChannel.ConnectionHops[0] {
+		return 0, "", errorsmod.Wrapf(connectiontypes.ErrInvalidConnection, "unexpected counterparty channel connection hops, expected %s but got %s", connectionEnd.GetCounterparty().GetConnectionID(), counterpartyChannel.ConnectionHops[0])
+	}
+
+	if err := k.connectionKeeper.VerifyChannelState(ctx, connectionEnd, proofHeight, proofChannel, proposedUpgradeChannel.Counterparty.PortId,
+		proposedUpgradeChannel.Counterparty.ChannelId, counterpartyChannel); err != nil {
+		return 0, "", err
+	}
+
+	upgradeTimeout := types.UpgradeTimeout{TimeoutHeight: timeoutHeight, TimeoutTimestamp: timeoutTimestamp}
+	if err := k.connectionKeeper.VerifyChannelUpgradeTimeout(ctx, connectionEnd, proofHeight, proofUpgradeTimeout, proposedUpgradeChannel.Counterparty.PortId,
+		proposedUpgradeChannel.Counterparty.ChannelId, upgradeTimeout); err != nil {
+		return 0, "", err
+	}
+
+	if err := k.connectionKeeper.VerifyChannelUpgradeSequence(ctx, connectionEnd, proofHeight, proofUpgradeSequence, proposedUpgradeChannel.Counterparty.PortId,
+		proposedUpgradeChannel.Counterparty.ChannelId, counterpartyUpgradeSequence); err != nil {
+		return 0, "", err
+	}
+
+	// check if upgrade timed out by comparing it with the latest height of the chain
+	selfHeight := clienttypes.GetSelfHeight(ctx)
+	if !timeoutHeight.IsZero() && selfHeight.GTE(timeoutHeight) {
+		if err := k.RestoreChannelAndWriteErrorReceipt(ctx, portID, channelID, upgradeSequence, types.ErrUpgradeTimeout); err != nil {
+			return 0, "", errorsmod.Wrap(types.ErrUpgradeAborted, err.Error())
+		}
+		return 0, "", errorsmod.Wrap(types.ErrUpgradeAborted, "upgrade timed out")
+	}
+
+	// check if upgrade timed out by comparing it with the latest timestamp of the chain
+	if timeoutTimestamp != 0 && uint64(ctx.BlockTime().UnixNano()) >= timeoutTimestamp {
+		if err := k.RestoreChannelAndWriteErrorReceipt(ctx, portID, channelID, upgradeSequence, types.ErrUpgradeTimeout); err != nil {
+			return 0, "", errorsmod.Wrap(types.ErrUpgradeAborted, err.Error())
+		}
+		return 0, "", errorsmod.Wrap(types.ErrUpgradeAborted, "upgrade timed out")
+	}
+
+	switch channel.State {
+	case types.OPEN:
+		upgradeSequence = uint64(0)
+		if seq, found := k.GetUpgradeSequence(ctx, portID, channelID); found {
+			upgradeSequence = seq
+		}
+
+		// if the counterparty upgrade sequence is ahead then fast forward so both channel ends are using the same sequence for the current upgrade
+		if counterpartyUpgradeSequence > upgradeSequence {
+			upgradeSequence = counterpartyUpgradeSequence
+			k.SetUpgradeSequence(ctx, portID, channelID, upgradeSequence)
+		} else {
+			errorReceipt := types.NewErrorReceipt(upgradeSequence, errorsmod.Wrapf(types.ErrUpgradeAborted, "upgrade sequence %d was not smaller than the counter party chain upgrade sequence %d", upgradeSequence, counterpartyUpgradeSequence))
+			// the upgrade sequence is incremented so both sides start the next upgrade with a fresh sequence.
+			upgradeSequence++
+
+			k.SetUpgradeErrorReceipt(ctx, portID, channelID, errorReceipt)
+			k.SetUpgradeSequence(ctx, portID, channelID, upgradeSequence)
+
+			// TODO: emit error receipt events
+
+			// do we want to return upgrade sequence here to include in response??
+			return 0, "", errorsmod.Wrapf(types.ErrUpgradeAborted, "upgrade aborted, error receipt written for upgrade sequence: %d", errorReceipt.GetSequence())
+		}
+
+		// this is first message in upgrade handshake on this chain so we must store original channel in restore channel path
+		// in case we need to restore channel later.
+		k.SetUpgradeRestoreChannel(ctx, portID, channelID, channel)
+	case types.INITUPGRADE:
+		upgradeSequence, found = k.GetUpgradeSequence(ctx, portID, channelID)
+		if !found {
+			errorReceipt := types.NewErrorReceipt(upgradeSequence, errorsmod.Wrapf(types.ErrUpgradeAborted, "upgrade sequence %d was not smaller than the counter party chain upgrade sequence %d", upgradeSequence, counterpartyUpgradeSequence))
+			k.SetUpgradeErrorReceipt(ctx, portID, channelID, errorReceipt)
+
+			return 0, "", errorsmod.Wrapf(types.ErrUpgradeAborted, "upgrade aborted, error receipt written for upgrade sequence: %d", upgradeSequence)
+		}
+
+		if upgradeSequence != counterpartyUpgradeSequence {
+			errorReceipt := types.NewErrorReceipt(upgradeSequence, errorsmod.Wrapf(types.ErrUpgradeAborted, "upgrade sequence %d was not equal to the counter party chain upgrade sequence %d", upgradeSequence, counterpartyUpgradeSequence))
+
+			// set to the max of the two
+			if counterpartyUpgradeSequence > upgradeSequence {
+				upgradeSequence = counterpartyUpgradeSequence
+				k.SetUpgradeSequence(ctx, portID, channelID, upgradeSequence)
+			}
+
+			k.SetUpgradeErrorReceipt(ctx, portID, channelID, errorReceipt)
+			return 0, "", errorsmod.Wrapf(types.ErrUpgradeAborted, "upgrade aborted, error receipt written for upgrade sequence: %d", upgradeSequence)
+		}
+
+		// if there is a crossing hello, i.e an UpgradeInit has been called on both channelEnds,
+		// then we must ensure that the proposedUpgrade by the counterparty is the same as the currentChannel
+		// except for the channel state (upgrade channel will be in TRYUPGRADE and current channel will be in INITUPGRADE)
+		// if the proposed upgrades on either side are incompatible, then we will restore the channel and cancel the upgrade.
+		channel.State = types.TRYUPGRADE
+		k.SetChannel(ctx, portID, channelID, channel)
+
+		if !reflect.DeepEqual(channel, proposedUpgradeChannel) {
+			// TODO: log and emit events
+			if err := k.RestoreChannelAndWriteErrorReceipt(ctx, portID, channelID, upgradeSequence, types.ErrInvalidChannel); err != nil {
+				return 0, "", errorsmod.Wrap(types.ErrUpgradeAborted, err.Error())
+			}
+			return 0, "", errorsmod.Wrap(types.ErrUpgradeAborted, "proposed upgrade channel did not equal expected channel")
+		}
+
+		// retrieve restore channel to return previous version
+		restoreChannel, found := k.GetUpgradeRestoreChannel(ctx, portID, channelID)
+		if !found {
+			//(this case should be unreachable): write error receipt for upgrade sequence and abort / cancel upgrade
+			errorReceipt := types.NewErrorReceipt(upgradeSequence, err)
+			k.SetUpgradeErrorReceipt(ctx, portID, channelID, errorReceipt)
+			return 0, "", errorsmod.Wrapf(types.ErrChannelNotFound, "upgrade aborted, error receipt written for upgrade sequence: %d", upgradeSequence)
+		}
+
+		return upgradeSequence, restoreChannel.Version, nil
+	default:
+		return 0, "", errorsmod.Wrapf(types.ErrInvalidChannelState, "expected one of [%s, %s] but got %s", types.OPEN, types.INITUPGRADE, channel.State)
+	}
+
+	return upgradeSequence, channel.Version, nil
 }
 
-// RestoreChannel restores the given channel to the state prior to upgrade.
-func (k Keeper) RestoreChannel(ctx sdk.Context, portID, channelID string, upgradeSequence uint64, err error) error {
+// WriteUpgradeTryChannel writes a channel which has successfully passed the UpgradeTry handshake step.
+// An event is emitted for the handshake step.
+func (k Keeper) WriteUpgradeTryChannel(
+	ctx sdk.Context,
+	portID,
+	channelID,
+	proposedUpgradeVersion string,
+	upgradeSequence uint64,
+	channelUpgrade types.Channel,
+) error {
+	defer telemetry.IncrCounter(1, "ibc", "channel", "upgrade-try")
+
+	channel, found := k.GetChannel(ctx, portID, channelID)
+	if !found {
+		return errorsmod.Wrapf(types.ErrChannelNotFound, "failed to retrieve channel %s on port %s", channelID, portID)
+	}
+
+	// assign directly the fields that are modifiable.
+	// counterparty fields may not be changed.
+	channel.Version = proposedUpgradeVersion
+	channel.Ordering = channelUpgrade.Ordering
+	channel.ConnectionHops = channelUpgrade.ConnectionHops
+
+	// prevent silent failures if fields that are not allowed to be modified are changed in the upgrade channel
+	// request.
+	if !reflect.DeepEqual(channel, channelUpgrade) {
+		return errorsmod.Wrapf(types.ErrInvalidChannel, "expected: %v but got: %v", channel, channelUpgrade)
+	}
+
+	k.SetChannel(ctx, portID, channelID, channel)
+
+	// TODO: previous state will not be OPEN in the case of crossing hellos. Determine this state correctly.
+	k.Logger(ctx).Info("channel state updated", "port-id", portID, "channel-id", channelID, "previous-state", types.OPEN.String(), "new-state", types.TRYUPGRADE.String())
+
+	emitChannelUpgradeTryEvent(ctx, portID, channelID, upgradeSequence, channelUpgrade)
+	return nil
+}
+
+// TODO: should we pull out the error receipt logic from this function? They seem like two discrete operations.
+
+// RestoreChannelAndWriteErrorReceipt restores the given channel to the state prior to upgrade.
+func (k Keeper) RestoreChannelAndWriteErrorReceipt(ctx sdk.Context, portID, channelID string, upgradeSequence uint64, err error) error {
 	errorReceipt := types.NewErrorReceipt(upgradeSequence, err)
 	k.SetUpgradeErrorReceipt(ctx, portID, channelID, errorReceipt)
 
@@ -124,5 +358,31 @@ func (k Keeper) RestoreChannel(ctx sdk.Context, portID, channelID string, upgrad
 		return errorsmod.Wrapf(porttypes.ErrInvalidRoute, "route not found to module: %s", module)
 	}
 
-	return cbs.OnChanUpgradeRestore(ctx, portID, channelID)
+	cbs.OnChanUpgradeRestore(ctx, portID, channelID)
+	return nil
+}
+
+// getUpgradeTryConnectionEnd returns the connection end that should be used. During crossing hellos, the restore
+// channel connection end is used, while in a regular flow the current channel connection end is used.
+func (k Keeper) getUpgradeTryConnectionEnd(ctx sdk.Context, portID string, channelID string, currentChannel types.Channel) (exported.ConnectionI, error) {
+	isCrossingHellos := currentChannel.State == types.INITUPGRADE
+	if isCrossingHellos {
+		// fetch restore channel
+		restoreChannel, found := k.GetUpgradeRestoreChannel(ctx, portID, channelID)
+		if !found {
+			return nil, errorsmod.Wrapf(types.ErrChannelNotFound, "port ID (%s) channel ID (%s)", portID, channelID)
+		}
+		connectionEnd, err := k.GetConnection(ctx, restoreChannel.ConnectionHops[0])
+		if err != nil {
+			return nil, err
+		}
+		return connectionEnd, nil
+	}
+
+	// use current channel
+	connectionEnd, err := k.GetConnection(ctx, currentChannel.ConnectionHops[0])
+	if err != nil {
+		return nil, err
+	}
+	return connectionEnd, nil
 }