ICS 29: Fee Middleware

modules/apps/29-fee/client/cli/cli.go

@@ -0,0 +1,39 @@
+package cli
+
+import (
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/spf13/cobra"
+)
+
+// GetQueryCmd returns the query commands for 29-fee
+func GetQueryCmd() *cobra.Command {
+	queryCmd := &cobra.Command{
+		Use:                        "ibc-fee",
+		Short:                      "", // TODO
+		DisableFlagParsing:         true,
+		SuggestionsMinimumDistance: 2,
+	}
+
+	queryCmd.AddCommand(
+	// TODO
+	)
+
+	return queryCmd
+}
+
+// NewTxCmd returns the transaction commands for 29-fee
+func NewTxCmd() *cobra.Command {
+	txCmd := &cobra.Command{
+		Use:                        "ibc-fee",
+		Short:                      "", // TODO
+		DisableFlagParsing:         true,
+		SuggestionsMinimumDistance: 2,
+		RunE:                       client.ValidateCmd,
+	}
+
+	txCmd.AddCommand(
+	// TODO
+	)
+
+	return txCmd
+}

modules/apps/29-fee/client/cli/query.go

@@ -0,0 +1,3 @@
+package cli
+
+// TODO

modules/apps/29-fee/client/cli/tx.go

@@ -0,0 +1,3 @@
+package cli
+
+// TODO

modules/apps/29-fee/fee_test.go

@@ -0,0 +1,64 @@
+package fee_test
+
+import (
+	"testing"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/cosmos/ibc-go/v3/modules/apps/29-fee/types"
+	transfertypes "github.com/cosmos/ibc-go/v3/modules/apps/transfer/types"
+	clienttypes "github.com/cosmos/ibc-go/v3/modules/core/02-client/types"
+	channeltypes "github.com/cosmos/ibc-go/v3/modules/core/04-channel/types"
+	ibctesting "github.com/cosmos/ibc-go/v3/testing"
+)
+
+type FeeTestSuite struct {
+	suite.Suite
+
+	coordinator *ibctesting.Coordinator
+
+	chainA *ibctesting.TestChain
+	chainB *ibctesting.TestChain
+
+	path *ibctesting.Path
+}
+
+func (suite *FeeTestSuite) SetupTest() {
+	suite.coordinator = ibctesting.NewCoordinator(suite.T(), 2)
+	suite.chainA = suite.coordinator.GetChain(ibctesting.GetChainID(0))
+	suite.chainB = suite.coordinator.GetChain(ibctesting.GetChainID(1))
+
+	path := ibctesting.NewPath(suite.chainA, suite.chainB)
+	feeTransferVersion := channeltypes.MergeChannelVersions(types.Version, transfertypes.Version)
+	path.EndpointA.ChannelConfig.Version = feeTransferVersion
+	path.EndpointB.ChannelConfig.Version = feeTransferVersion
+	path.EndpointA.ChannelConfig.PortID = transfertypes.PortID
+	path.EndpointB.ChannelConfig.PortID = transfertypes.PortID
+	suite.path = path
+}
+
+func TestIBCFeeTestSuite(t *testing.T) {
+	suite.Run(t, new(FeeTestSuite))
+}
+
+func (suite *FeeTestSuite) CreateICS20Packet(coin sdk.Coin) channeltypes.Packet {
+
+	fungibleTokenPacket := transfertypes.NewFungibleTokenPacketData(
+		coin.Denom,
+		sdk.NewInt(100).String(),
+		suite.chainA.SenderAccount.GetAddress().String(),
+		suite.chainB.SenderAccount.GetAddress().String(),
+	)
+
+	return channeltypes.NewPacket(
+		fungibleTokenPacket.GetBytes(),
+		suite.chainA.SenderAccount.GetSequence(),
+		suite.path.EndpointA.ChannelConfig.PortID,
+		suite.path.EndpointA.ChannelID,
+		suite.path.EndpointB.ChannelConfig.PortID,
+		suite.path.EndpointB.ChannelID,
+		clienttypes.NewHeight(0, 100),
+		0,
+	)
+}

modules/apps/29-fee/ibc_module.go

@@ -0,0 +1,253 @@
+package fee
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	capabilitytypes "github.com/cosmos/cosmos-sdk/x/capability/types"
+
+	"github.com/cosmos/ibc-go/v3/modules/apps/29-fee/keeper"
+	"github.com/cosmos/ibc-go/v3/modules/apps/29-fee/types"
+	channeltypes "github.com/cosmos/ibc-go/v3/modules/core/04-channel/types"
+	porttypes "github.com/cosmos/ibc-go/v3/modules/core/05-port/types"
+	"github.com/cosmos/ibc-go/v3/modules/core/exported"
+)
+
+// IBCModule implements the ICS26 callbacks for the fee middleware given the fee keeper and the underlying application.
+type IBCModule struct {
+	keeper keeper.Keeper
+	app    porttypes.IBCModule
+}
+
+// NewIBCModule creates a new IBCModule given the keeper and underlying application
+func NewIBCModule(k keeper.Keeper, app porttypes.IBCModule) IBCModule {
+	return IBCModule{
+		keeper: k,
+		app:    app,
+	}
+}
+
+// OnChanOpenInit implements the IBCModule interface
+func (im IBCModule) OnChanOpenInit(
+	ctx sdk.Context,
+	order channeltypes.Order,
+	connectionHops []string,
+	portID string,
+	channelID string,
+	chanCap *capabilitytypes.Capability,
+	counterparty channeltypes.Counterparty,
+	version string,
+) error {
+	mwVersion, appVersion := channeltypes.SplitChannelVersion(version)
+	// Since it is valid for fee version to not be specified, the above middleware version may be for a middleware
+	// lower down in the stack. Thus, if it is not a fee version we pass the entire version string onto the underlying
+	// application.
+	// If an invalid fee version was passed, we expect the underlying application to fail on its version negotiation.
+	if mwVersion == types.Version {
+		im.keeper.SetFeeEnabled(ctx, portID, channelID)
+	} else {
+		// middleware version is not the expected version for this midddleware. Pass the full version string along,
+		// if it not valid version for any other lower middleware, an error will be returned by base application.
+		appVersion = version
+	}
+
+	// call underlying app's OnChanOpenInit callback with the appVersion
+	return im.app.OnChanOpenInit(ctx, order, connectionHops, portID, channelID,
+		chanCap, counterparty, appVersion)
+}
+
+// OnChanOpenTry implements the IBCModule interface
+// If the channel is not fee enabled the underlying application version will be returned
+// If the channel is fee enabled we merge the underlying application version with the ics29 version
+func (im IBCModule) OnChanOpenTry(
+	ctx sdk.Context,
+	order channeltypes.Order,
+	connectionHops []string,
+	portID,
+	channelID string,
+	chanCap *capabilitytypes.Capability,
+	counterparty channeltypes.Counterparty,
+	counterpartyVersion string,
+) (string, error) {
+	cpMwVersion, cpAppVersion := channeltypes.SplitChannelVersion(counterpartyVersion)
+
+	// Since it is valid for fee version to not be specified, the above middleware version may be for a middleware
+	// lower down in the stack. Thus, if it is not a fee version we pass the entire version string onto the underlying
+	// application.
+	// If an invalid fee version was passed, we expect the underlying application to fail on its version negotiation.
+	if cpMwVersion == types.Version {
+		im.keeper.SetFeeEnabled(ctx, portID, channelID)
+	} else {
+		// middleware versions are not the expected version for this midddleware. Pass the full version strings along,
+		// if it not valid version for any other lower middleware, an error will be returned by base application.
+		cpAppVersion = counterpartyVersion
+	}
+
+	// call underlying app's OnChanOpenTry callback with the app versions
+	appVersion, err := im.app.OnChanOpenTry(ctx, order, connectionHops, portID, channelID, chanCap, counterparty, cpAppVersion)
+	if err != nil {
+		return "", err
+	}
+
+	if !im.keeper.IsFeeEnabled(ctx, portID, channelID) {
+		return appVersion, nil
+	}
+
+	return channeltypes.MergeChannelVersions(types.Version, appVersion), nil
+}
+
+// OnChanOpenAck implements the IBCModule interface
+func (im IBCModule) OnChanOpenAck(
+	ctx sdk.Context,
+	portID,
+	channelID string,
+	counterpartyVersion string,
+) error {
+	// If handshake was initialized with fee enabled it must complete with fee enabled.
+	// If handshake was initialized with fee disabled it must complete with fee disabled.
+	cpAppVersion := counterpartyVersion
+	if im.keeper.IsFeeEnabled(ctx, portID, channelID) {
+		var cpFeeVersion string
+		cpFeeVersion, cpAppVersion = channeltypes.SplitChannelVersion(counterpartyVersion)
+
+		if cpFeeVersion != types.Version {
+			return sdkerrors.Wrapf(types.ErrInvalidVersion, "expected counterparty version: %s, got: %s", types.Version, cpFeeVersion)
+		}
+	}
+	// call underlying app's OnChanOpenAck callback with the counterparty app version.
+	return im.app.OnChanOpenAck(ctx, portID, channelID, cpAppVersion)
+}
+
+// OnChanOpenConfirm implements the IBCModule interface
+func (im IBCModule) OnChanOpenConfirm(
+	ctx sdk.Context,
+	portID,
+	channelID string,
+) error {
+	// call underlying app's OnChanOpenConfirm callback.
+	return im.app.OnChanOpenConfirm(ctx, portID, channelID)
+}
+
+// OnChanCloseInit implements the IBCModule interface
+func (im IBCModule) OnChanCloseInit(
+	ctx sdk.Context,
+	portID,
+	channelID string,
+) error {
+	// delete fee enabled on channel
+	// and refund any remaining fees escrowed on channel
+	im.keeper.DeleteFeeEnabled(ctx, portID, channelID)
+	err := im.keeper.RefundFeesOnChannel(ctx, portID, channelID)
+	// error should only be non-nil if there is a bug in the code
+	// that causes module account to have insufficient funds to refund
+	// all escrowed fees on the channel.
+	// Disable all channels to allow for coordinated fix to the issue
+	// and mitigate/reverse damage.
+	// NOTE: Underlying application's packets will still go through, but
+	// fee module will be disabled for all channels
+	if err != nil {
+		im.keeper.DisableAllChannels(ctx)
+	}
+	return im.app.OnChanCloseInit(ctx, portID, channelID)
+}
+
+// OnChanCloseConfirm implements the IBCModule interface
+func (im IBCModule) OnChanCloseConfirm(
+	ctx sdk.Context,
+	portID,
+	channelID string,
+) error {
+	// delete fee enabled on channel
+	// and refund any remaining fees escrowed on channel
+	im.keeper.DeleteFeeEnabled(ctx, portID, channelID)
+	err := im.keeper.RefundFeesOnChannel(ctx, portID, channelID)
+	// error should only be non-nil if there is a bug in the code
+	// that causes module account to have insufficient funds to refund
+	// all escrowed fees on the channel.
+	// Disable all channels to allow for coordinated fix to the issue
+	// and mitigate/reverse damage.
+	// NOTE: Underlying application's packets will still go through, but
+	// fee module will be disabled for all channels
+	if err != nil {
+		im.keeper.DisableAllChannels(ctx)
+	}
+	return im.app.OnChanCloseConfirm(ctx, portID, channelID)
+}
+
+// OnRecvPacket implements the IBCModule interface.
+// If fees are not enabled, this callback will default to the ibc-core packet callback
+func (im IBCModule) OnRecvPacket(
+	ctx sdk.Context,
+	packet channeltypes.Packet,
+	relayer sdk.AccAddress,
+) exported.Acknowledgement {
+	if !im.keeper.IsFeeEnabled(ctx, packet.DestinationPort, packet.DestinationChannel) {
+		return im.app.OnRecvPacket(ctx, packet, relayer)
+	}
+
+	ack := im.app.OnRecvPacket(ctx, packet, relayer)
+
+	forwardRelayer, found := im.keeper.GetCounterpartyAddress(ctx, relayer.String())
+
+	// incase of async aknowledgement (ack == nil) store the ForwardRelayer address for use later
+	if ack == nil && found {
+		im.keeper.SetForwardRelayerAddress(ctx, channeltypes.NewPacketId(packet.GetSourceChannel(), packet.GetSourcePort(), packet.GetSequence()), forwardRelayer)
+	}
+
+	return types.NewIncentivizedAcknowledgement(forwardRelayer, ack.Acknowledgement())
+}
+
+// OnAcknowledgementPacket implements the IBCModule interface
+// If fees are not enabled, this callback will default to the ibc-core packet callback
+func (im IBCModule) OnAcknowledgementPacket(
+	ctx sdk.Context,
+	packet channeltypes.Packet,
+	acknowledgement []byte,
+	relayer sdk.AccAddress,
+) error {
+	if !im.keeper.IsFeeEnabled(ctx, packet.SourcePort, packet.SourceChannel) {
+		return im.app.OnAcknowledgementPacket(ctx, packet, acknowledgement, relayer)
+	}
+
+	ack := new(types.IncentivizedAcknowledgement)
+	if err := types.ModuleCdc.UnmarshalJSON(acknowledgement, ack); err != nil {
+		return sdkerrors.Wrapf(err, "cannot unmarshal ICS-29 incentivized packet acknowledgement: %v", ack)
+	}
+
+	packetId := channeltypes.NewPacketId(packet.SourceChannel, packet.SourcePort, packet.Sequence)
+
+	identifiedPacketFee, found := im.keeper.GetFeeInEscrow(ctx, packetId)
+	if !found {
+		// return underlying callback if no fee found for given packetID
+		return im.app.OnAcknowledgementPacket(ctx, packet, ack.Result, relayer)
+	}
+
+	im.keeper.DistributePacketFees(ctx, identifiedPacketFee.RefundAddress, ack.ForwardRelayerAddress, relayer, identifiedPacketFee)
+
+	// call underlying callback
+	return im.app.OnAcknowledgementPacket(ctx, packet, ack.Result, relayer)
+}
+
+// OnTimeoutPacket implements the IBCModule interface
+// If fees are not enabled, this callback will default to the ibc-core packet callback
+func (im IBCModule) OnTimeoutPacket(
+	ctx sdk.Context,
+	packet channeltypes.Packet,
+	relayer sdk.AccAddress,
+) error {
+	if !im.keeper.IsFeeEnabled(ctx, packet.SourcePort, packet.SourceChannel) {
+		return im.app.OnTimeoutPacket(ctx, packet, relayer)
+	}
+
+	packetId := channeltypes.NewPacketId(packet.SourceChannel, packet.SourcePort, packet.Sequence)
+
+	identifiedPacketFee, found := im.keeper.GetFeeInEscrow(ctx, packetId)
+	if !found {
+		// return underlying callback if fee not found for given packetID
+		return im.app.OnTimeoutPacket(ctx, packet, relayer)
+	}
+
+	im.keeper.DistributePacketFeesOnTimeout(ctx, identifiedPacketFee.RefundAddress, relayer, identifiedPacketFee)
+
+	// call underlying callback
+	return im.app.OnTimeoutPacket(ctx, packet, relayer)
+}