feat: Add handshake logic to ics29 (#307)

* do handshake logic, create test file

* do cap logic and fix build

* open handshake implementation and tests

* remove prints

* Update modules/apps/29-fee/module.go

Co-authored-by: Sean King <seantking@users.noreply.github.com>

* debugging progress

* fee enabled flag

* cleanup handshake logic

* fix tests

* much cleaner simapp

* split module.go file

* cleanup and docs

* assert IBC interfaces are fulfilled in middleware

* Update modules/apps/transfer/module.go

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>

* Apply suggestions from code review

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>

* fix unnecessary crossing hello logic

* fix version negotiation bugs and improve tests

* cleanup tests

* Apply suggestions from code review

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>

* Apply suggestions from code review

Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>

* address rest of colin comments

Co-authored-by: Sean King <seantking@users.noreply.github.com>
Co-authored-by: colin axnér <25233464+colin-axner@users.noreply.github.com>

modules/apps/29-fee/fee_test.go

@@ -0,0 +1,41 @@
+package fee_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+
+	"github.com/cosmos/ibc-go/modules/apps/29-fee/types"
+	transfertypes "github.com/cosmos/ibc-go/modules/apps/transfer/types"
+	channeltypes "github.com/cosmos/ibc-go/modules/core/04-channel/types"
+	ibctesting "github.com/cosmos/ibc-go/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))
+}

modules/apps/29-fee/ibc_module.go

@@ -0,0 +1,178 @@
+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/modules/apps/29-fee/keeper"
+	"github.com/cosmos/ibc-go/modules/apps/29-fee/types"
+	channeltypes "github.com/cosmos/ibc-go/modules/core/04-channel/types"
+	porttypes "github.com/cosmos/ibc-go/modules/core/05-port/types"
+	ibcexported "github.com/cosmos/ibc-go/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
+func (im IBCModule) OnChanOpenTry(
+	ctx sdk.Context,
+	order channeltypes.Order,
+	connectionHops []string,
+	portID,
+	channelID string,
+	chanCap *capabilitytypes.Capability,
+	counterparty channeltypes.Counterparty,
+	version,
+	counterpartyVersion string,
+) error {
+	mwVersion, appVersion := channeltypes.SplitChannelVersion(version)
+	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 mwVersion == types.Version || cpMwVersion == types.Version {
+		if cpMwVersion != mwVersion {
+			return sdkerrors.Wrapf(types.ErrInvalidVersion, "fee versions do not match. self version: %s, counterparty version: %s", mwVersion, cpMwVersion)
+		}
+
+		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.
+		appVersion = version
+		cpAppVersion = counterpartyVersion
+	}
+
+	// call underlying app's OnChanOpenTry callback with the app versions
+	return im.app.OnChanOpenTry(ctx, order, connectionHops, portID, channelID,
+		chanCap, counterparty, appVersion, cpAppVersion)
+}
+
+// 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 {
+	// TODO: Unescrow all remaining funds for unprocessed packets
+	im.keeper.DeleteFeeEnabled(ctx, portID, channelID)
+	return im.app.OnChanCloseInit(ctx, portID, channelID)
+}
+
+// OnChanCloseConfirm implements the IBCModule interface
+func (im IBCModule) OnChanCloseConfirm(
+	ctx sdk.Context,
+	portID,
+	channelID string,
+) error {
+	// TODO: Unescrow all remaining funds for unprocessed packets
+	im.keeper.DeleteFeeEnabled(ctx, portID, channelID)
+	return im.app.OnChanCloseConfirm(ctx, portID, channelID)
+}
+
+// OnRecvPacket implements the IBCModule interface.
+func (im IBCModule) OnRecvPacket(
+	ctx sdk.Context,
+	packet channeltypes.Packet,
+	relayer sdk.AccAddress,
+) ibcexported.Acknowledgement {
+	// TODO: Implement fee specific logic if fee is enabled for the given channel
+	return im.app.OnRecvPacket(ctx, packet, relayer)
+}
+
+// OnAcknowledgementPacket implements the IBCModule interface
+func (im IBCModule) OnAcknowledgementPacket(
+	ctx sdk.Context,
+	packet channeltypes.Packet,
+	acknowledgement []byte,
+	relayer sdk.AccAddress,
+) error {
+	// TODO: Implement fee specific logic if fee is enabled for the given channel
+	return im.app.OnAcknowledgementPacket(ctx, packet, acknowledgement, relayer)
+}
+
+// OnTimeoutPacket implements the IBCModule interface
+func (im IBCModule) OnTimeoutPacket(
+	ctx sdk.Context,
+	packet channeltypes.Packet,
+	relayer sdk.AccAddress,
+) error {
+	// TODO: Implement fee specific logic if fee is enabled for the given channel
+	return im.app.OnTimeoutPacket(ctx, packet, relayer)
+}