ibc_module.go

package transfer

import (
	"fmt"
	"math"
	"strings"

	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/transfer/keeper"
	"github.com/cosmos/ibc-go/v3/modules/apps/transfer/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"
	host "github.com/cosmos/ibc-go/v3/modules/core/24-host"
	ibcexported "github.com/cosmos/ibc-go/v3/modules/core/exported"
)

// IBCModule implements the ICS26 interface for transfer given the transfer keeper.
type IBCModule struct {
	keeper keeper.Keeper
}

// NewIBCModule creates a new IBCModule given the keeper
func NewIBCModule(k keeper.Keeper) IBCModule {
	return IBCModule{
		keeper: k,
	}
}

// ValidateTransferChannelParams does validation of a newly created transfer channel. A transfer
// channel must be UNORDERED, use the correct port (by default 'transfer'), and use the current
// supported version. Only 2^32 channels are allowed to be created.
func ValidateTransferChannelParams(
	ctx sdk.Context,
	keeper keeper.Keeper,
	order channeltypes.Order,
	portID string,
	channelID string,
) error {
	// NOTE: for escrow address security only 2^32 channels are allowed to be created
	// Issue: https://github.com/cosmos/cosmos-sdk/issues/7737
	channelSequence, err := channeltypes.ParseChannelSequence(channelID)
	if err != nil {
		return err
	}
	if channelSequence > uint64(math.MaxUint32) {
		return sdkerrors.Wrapf(types.ErrMaxTransferChannels, "channel sequence %d is greater than max allowed transfer channels %d", channelSequence, uint64(math.MaxUint32))
	}
	if order != channeltypes.UNORDERED {
		return sdkerrors.Wrapf(channeltypes.ErrInvalidChannelOrdering, "expected %s channel, got %s ", channeltypes.UNORDERED, order)
	}

	// Require portID is the portID transfer module is bound to
	boundPort := keeper.GetPort(ctx)
	if boundPort != portID {
		return sdkerrors.Wrapf(porttypes.ErrInvalidPort, "invalid port: %s, expected %s", portID, boundPort)
	}

	return nil
}

// 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,
) (string, error) {
	if err := ValidateTransferChannelParams(ctx, im.keeper, order, portID, channelID); err != nil {
		return "", err
	}

	if strings.TrimSpace(version) == "" {
		version = types.Version
	}

	if version != types.Version {
		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "got %s, expected %s", version, types.Version)
	}

	// Claim channel capability passed back by IBC module
	if err := im.keeper.ClaimCapability(ctx, chanCap, host.ChannelCapabilityPath(portID, channelID)); err != nil {
		return "", err
	}

	return version, nil
}

// 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,
	counterpartyVersion string,
) (string, error) {
	if err := ValidateTransferChannelParams(ctx, im.keeper, order, portID, channelID); err != nil {
		return "", err
	}

	if counterpartyVersion != types.Version {
		return "", sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid counterparty version: got: %s, expected %s", counterpartyVersion, types.Version)
	}

	// Module may have already claimed capability in OnChanOpenInit in the case of crossing hellos
	// (ie chainA and chainB both call ChanOpenInit before one of them calls ChanOpenTry)
	// If module can already authenticate the capability then module already owns it so we don't need to claim
	// Otherwise, module does not have channel capability and we must claim it from IBC
	if !im.keeper.AuthenticateCapability(ctx, chanCap, host.ChannelCapabilityPath(portID, channelID)) {
		// Only claim channel capability passed back by IBC module if we do not already own it
		if err := im.keeper.ClaimCapability(ctx, chanCap, host.ChannelCapabilityPath(portID, channelID)); err != nil {
			return "", err
		}
	}

	return types.Version, nil
}

// OnChanOpenAck implements the IBCModule interface
func (im IBCModule) OnChanOpenAck(
	ctx sdk.Context,
	portID,
	channelID string,
	_ string,
	counterpartyVersion string,
) error {
	if counterpartyVersion != types.Version {
		return sdkerrors.Wrapf(types.ErrInvalidVersion, "invalid counterparty version: %s, expected %s", counterpartyVersion, types.Version)
	}
	return nil
}

// OnChanOpenConfirm implements the IBCModule interface
func (im IBCModule) OnChanOpenConfirm(
	ctx sdk.Context,
	portID,
	channelID string,
) error {
	return nil
}

// OnChanCloseInit implements the IBCModule interface
func (im IBCModule) OnChanCloseInit(
	ctx sdk.Context,
	portID,
	channelID string,
) error {
	// Disallow user-initiated channel closing for transfer channels
	return sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "user cannot close channel")
}

// OnChanCloseConfirm implements the IBCModule interface
func (im IBCModule) OnChanCloseConfirm(
	ctx sdk.Context,
	portID,
	channelID string,
) error {
	return nil
}

// OnRecvPacket implements the IBCModule interface. A successful acknowledgement
// is returned if the packet data is successfully decoded and the receive application
// logic returns without error.
func (im IBCModule) OnRecvPacket(
	ctx sdk.Context,
	packet channeltypes.Packet,
	relayer sdk.AccAddress,
) ibcexported.Acknowledgement {
	ack := channeltypes.NewResultAcknowledgement([]byte{byte(1)})

	var data types.FungibleTokenPacketData
	if err := types.ModuleCdc.UnmarshalJSON(packet.GetData(), &data); err != nil {
		ack = channeltypes.NewErrorAcknowledgement("cannot unmarshal ICS-20 transfer packet data")
	}

	// only attempt the application logic if the packet data
	// was successfully decoded
	if ack.Success() {
		err := im.keeper.OnRecvPacket(ctx, packet, data)
		if err != nil {
			ack = types.NewErrorAcknowledgement(err)
		}
	}

	ctx.EventManager().EmitEvent(
		sdk.NewEvent(
			types.EventTypePacket,
			sdk.NewAttribute(sdk.AttributeKeyModule, types.ModuleName),
			sdk.NewAttribute(types.AttributeKeyReceiver, data.Receiver),
			sdk.NewAttribute(types.AttributeKeyDenom, data.Denom),
			sdk.NewAttribute(types.AttributeKeyAmount, data.Amount),
			sdk.NewAttribute(types.AttributeKeyAckSuccess, fmt.Sprintf("%t", ack.Success())),
		),
	)

	// NOTE: acknowledgement will be written synchronously during IBC handler execution.
	return ack
}

// OnAcknowledgementPacket implements the IBCModule interface
func (im IBCModule) OnAcknowledgementPacket(
	ctx sdk.Context,
	packet channeltypes.Packet,
	acknowledgement []byte,
	relayer sdk.AccAddress,
) error {
	var ack channeltypes.Acknowledgement
	if err := types.ModuleCdc.UnmarshalJSON(acknowledgement, &ack); err != nil {
		return sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "cannot unmarshal ICS-20 transfer packet acknowledgement: %v", err)
	}
	var data types.FungibleTokenPacketData
	if err := types.ModuleCdc.UnmarshalJSON(packet.GetData(), &data); err != nil {
		return sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "cannot unmarshal ICS-20 transfer packet data: %s", err.Error())
	}

	if err := im.keeper.OnAcknowledgementPacket(ctx, packet, data, ack); err != nil {
		return err
	}

	ctx.EventManager().EmitEvent(
		sdk.NewEvent(
			types.EventTypePacket,
			sdk.NewAttribute(sdk.AttributeKeyModule, types.ModuleName),
			sdk.NewAttribute(types.AttributeKeyReceiver, data.Receiver),
			sdk.NewAttribute(types.AttributeKeyDenom, data.Denom),
			sdk.NewAttribute(types.AttributeKeyAmount, data.Amount),
			sdk.NewAttribute(types.AttributeKeyAck, ack.String()),
		),
	)

	switch resp := ack.Response.(type) {
	case *channeltypes.Acknowledgement_Result:
		ctx.EventManager().EmitEvent(
			sdk.NewEvent(
				types.EventTypePacket,
				sdk.NewAttribute(types.AttributeKeyAckSuccess, string(resp.Result)),
			),
		)
	case *channeltypes.Acknowledgement_Error:
		ctx.EventManager().EmitEvent(
			sdk.NewEvent(
				types.EventTypePacket,
				sdk.NewAttribute(types.AttributeKeyAckError, resp.Error),
			),
		)
	}

	return nil
}

// OnTimeoutPacket implements the IBCModule interface
func (im IBCModule) OnTimeoutPacket(
	ctx sdk.Context,
	packet channeltypes.Packet,
	relayer sdk.AccAddress,
) error {
	var data types.FungibleTokenPacketData
	if err := types.ModuleCdc.UnmarshalJSON(packet.GetData(), &data); err != nil {
		return sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "cannot unmarshal ICS-20 transfer packet data: %s", err.Error())
	}
	// refund tokens
	if err := im.keeper.OnTimeoutPacket(ctx, packet, data); err != nil {
		return err
	}

	ctx.EventManager().EmitEvent(
		sdk.NewEvent(
			types.EventTypeTimeout,
			sdk.NewAttribute(sdk.AttributeKeyModule, types.ModuleName),
			sdk.NewAttribute(types.AttributeKeyRefundReceiver, data.Sender),
			sdk.NewAttribute(types.AttributeKeyRefundDenom, data.Denom),
			sdk.NewAttribute(types.AttributeKeyRefundAmount, data.Amount),
		),
	)

	return nil
}