Add relayer address to module callbacks (#206)

* Add relayer address to module callbacks

* Update CHANGELOG

* update migration docs

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

CHANGELOG.md

@@ -49,6 +49,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### API Breaking
 
+* (modules) [\#206](https://github.com/cosmos/ibc-go/pull/206) Expose `relayer sdk.AccAddress` on `OnRecvPacket`, `OnAcknowledgementPacket`, `OnTimeoutPacket` module callbacks to enable incentivization.
 * (02-client) [\#181](https://github.com/cosmos/ibc-go/pull/181) Remove 'InitialHeight' from UpdateClient Proposal. Only copy over latest consensus state from substitute client.
 * (06-solomachine) [\#169](https://github.com/cosmos/ibc-go/pull/169) Change FrozenSequence to boolean in solomachine ClientState. The solo machine proto package has been bumped from `v1` to `v2`.
 * (module/core/02-client) [\#165](https://github.com/cosmos/ibc-go/pull/165) Remove GetFrozenHeight from the ClientState interface. 

docs/migrations/ibc-migration-043.md

@@ -106,6 +106,8 @@ Application developers need to update their `OnRecvPacket` callback logic.
 
 The `OnRecvPacket` callback has been modified to only return the acknowledgement. The acknowledgement returned must implement the `Acknowledgement` interface. The acknowledgement should indicate if it represents a successful processing of a packet by returning true on `Success()` and false in all other cases. A return value of false on `Success()` will result in all state changes which occurred in the callback being discarded. More information can be found in the [documentation](https://github.com/cosmos/ibc-go/blob/main/docs/custom.md#receiving-packets).
 
+The `OnRecvPacket`, `OnAcknowledgementPacket`, and `OnTimeoutPacket` callbacks are now passed the `sdk.AccAddress` of the relayer who relayed the IBC packet. Applications may use or ignore this information. 
+
 ## IBC Event changes
 
 The `packet_data` attribute has been deprecated in favor of `packet_data_hex`, in order to provide standardized encoding/decoding of packet data in events. While the `packet_data` event still exists, all relayers and IBC Event consumers are strongly encouraged to switch over to using `packet_data_hex` as soon as possible.

modules/apps/transfer/module.go

@@ -323,6 +323,7 @@ func (am AppModule) OnChanCloseConfirm(
 func (am AppModule) OnRecvPacket(
 	ctx sdk.Context,
 	packet channeltypes.Packet,
+	relayer sdk.AccAddress,
 ) ibcexported.Acknowledgement {
 	ack := channeltypes.NewResultAcknowledgement([]byte{byte(1)})
 
@@ -360,6 +361,7 @@ func (am AppModule) OnAcknowledgementPacket(
 	ctx sdk.Context,
 	packet channeltypes.Packet,
 	acknowledgement []byte,
+	relayer sdk.AccAddress,
 ) (*sdk.Result, error) {
 	var ack channeltypes.Acknowledgement
 	if err := types.ModuleCdc.UnmarshalJSON(acknowledgement, &ack); err != nil {
@@ -411,6 +413,7 @@ func (am AppModule) OnAcknowledgementPacket(
 func (am AppModule) OnTimeoutPacket(
 	ctx sdk.Context,
 	packet channeltypes.Packet,
+	relayer sdk.AccAddress,
 ) (*sdk.Result, error) {
 	var data types.FungibleTokenPacketData
 	if err := types.ModuleCdc.UnmarshalJSON(packet.GetData(), &data); err != nil {

modules/core/05-port/types/module.go

@@ -67,16 +67,19 @@ type IBCModule interface {
 	OnRecvPacket(
 		ctx sdk.Context,
 		packet channeltypes.Packet,
+		relayer sdk.AccAddress,
 	) exported.Acknowledgement
 
 	OnAcknowledgementPacket(
 		ctx sdk.Context,
 		packet channeltypes.Packet,
 		acknowledgement []byte,
+		relayer sdk.AccAddress,
 	) (*sdk.Result, error)
 
 	OnTimeoutPacket(
 		ctx sdk.Context,
 		packet channeltypes.Packet,
+		relayer sdk.AccAddress,
 	) (*sdk.Result, error)
 }

modules/core/keeper/msg_server.go

@@ -424,6 +424,11 @@ func (k Keeper) ChannelCloseConfirm(goCtx context.Context, msg *channeltypes.Msg
 func (k Keeper) RecvPacket(goCtx context.Context, msg *channeltypes.MsgRecvPacket) (*channeltypes.MsgRecvPacketResponse, error) {
 	ctx := sdk.UnwrapSDKContext(goCtx)
 
+	relayer, err := sdk.AccAddressFromBech32(msg.Signer)
+	if err != nil {
+		return nil, sdkerrors.Wrap(err, "Invalid address for msg Signer")
+	}
+
 	// Lookup module by channel capability
 	module, cap, err := k.ChannelKeeper.LookupModuleByChannel(ctx, msg.Packet.DestinationPort, msg.Packet.DestinationChannel)
 	if err != nil {
@@ -444,7 +449,7 @@ func (k Keeper) RecvPacket(goCtx context.Context, msg *channeltypes.MsgRecvPacke
 	// Perform application logic callback
 	// Cache context so that we may discard state changes from callback if the acknowledgement is unsuccessful.
 	cacheCtx, writeFn := ctx.CacheContext()
-	ack := cbs.OnRecvPacket(cacheCtx, msg.Packet)
+	ack := cbs.OnRecvPacket(cacheCtx, msg.Packet, relayer)
 	if ack == nil || ack.Success() {
 		// write application state changes for asynchronous and successful acknowledgements
 		writeFn()
@@ -478,6 +483,12 @@ func (k Keeper) RecvPacket(goCtx context.Context, msg *channeltypes.MsgRecvPacke
 // Timeout defines a rpc handler method for MsgTimeout.
 func (k Keeper) Timeout(goCtx context.Context, msg *channeltypes.MsgTimeout) (*channeltypes.MsgTimeoutResponse, error) {
 	ctx := sdk.UnwrapSDKContext(goCtx)
+
+	relayer, err := sdk.AccAddressFromBech32(msg.Signer)
+	if err != nil {
+		return nil, sdkerrors.Wrap(err, "Invalid address for msg Signer")
+	}
+
 	// Lookup module by channel capability
 	module, cap, err := k.ChannelKeeper.LookupModuleByChannel(ctx, msg.Packet.SourcePort, msg.Packet.SourceChannel)
 	if err != nil {
@@ -496,7 +507,7 @@ func (k Keeper) Timeout(goCtx context.Context, msg *channeltypes.MsgTimeout) (*c
 	}
 
 	// Perform application logic callback
-	_, err = cbs.OnTimeoutPacket(ctx, msg.Packet)
+	_, err = cbs.OnTimeoutPacket(ctx, msg.Packet, relayer)
 	if err != nil {
 		return nil, sdkerrors.Wrap(err, "timeout packet callback failed")
 	}
@@ -527,6 +538,11 @@ func (k Keeper) Timeout(goCtx context.Context, msg *channeltypes.MsgTimeout) (*c
 func (k Keeper) TimeoutOnClose(goCtx context.Context, msg *channeltypes.MsgTimeoutOnClose) (*channeltypes.MsgTimeoutOnCloseResponse, error) {
 	ctx := sdk.UnwrapSDKContext(goCtx)
 
+	relayer, err := sdk.AccAddressFromBech32(msg.Signer)
+	if err != nil {
+		return nil, sdkerrors.Wrap(err, "Invalid address for msg Signer")
+	}
+
 	// Lookup module by channel capability
 	module, cap, err := k.ChannelKeeper.LookupModuleByChannel(ctx, msg.Packet.SourcePort, msg.Packet.SourceChannel)
 	if err != nil {
@@ -547,7 +563,7 @@ func (k Keeper) TimeoutOnClose(goCtx context.Context, msg *channeltypes.MsgTimeo
 	// Perform application logic callback
 	// NOTE: MsgTimeout and MsgTimeoutOnClose use the same "OnTimeoutPacket"
 	// application logic callback.
-	_, err = cbs.OnTimeoutPacket(ctx, msg.Packet)
+	_, err = cbs.OnTimeoutPacket(ctx, msg.Packet, relayer)
 	if err != nil {
 		return nil, sdkerrors.Wrap(err, "timeout packet callback failed")
 	}
@@ -578,6 +594,11 @@ func (k Keeper) TimeoutOnClose(goCtx context.Context, msg *channeltypes.MsgTimeo
 func (k Keeper) Acknowledgement(goCtx context.Context, msg *channeltypes.MsgAcknowledgement) (*channeltypes.MsgAcknowledgementResponse, error) {
 	ctx := sdk.UnwrapSDKContext(goCtx)
 
+	relayer, err := sdk.AccAddressFromBech32(msg.Signer)
+	if err != nil {
+		return nil, sdkerrors.Wrap(err, "Invalid address for msg Signer")
+	}
+
 	// Lookup module by channel capability
 	module, cap, err := k.ChannelKeeper.LookupModuleByChannel(ctx, msg.Packet.SourcePort, msg.Packet.SourceChannel)
 	if err != nil {
@@ -596,7 +617,7 @@ func (k Keeper) Acknowledgement(goCtx context.Context, msg *channeltypes.MsgAckn
 	}
 
 	// Perform application logic callback
-	_, err = cbs.OnAcknowledgementPacket(ctx, msg.Packet, msg.Acknowledgement)
+	_, err = cbs.OnAcknowledgementPacket(ctx, msg.Packet, msg.Acknowledgement, relayer)
 	if err != nil {
 		return nil, sdkerrors.Wrap(err, "acknowledge packet callback failed")
 	}

testing/mock/mock.go

@@ -17,6 +17,7 @@ import (
 	abci "github.com/tendermint/tendermint/abci/types"
 
 	channeltypes "github.com/cosmos/ibc-go/modules/core/04-channel/types"
+	porttypes "github.com/cosmos/ibc-go/modules/core/05-port/types"
 	host "github.com/cosmos/ibc-go/modules/core/24-host"
 	"github.com/cosmos/ibc-go/modules/core/exported"
 )
@@ -34,6 +35,8 @@ var (
 	MockCanaryCapabilityName = "mock canary capability name"
 )
 
+var _ porttypes.IBCModule = AppModule{}
+
 // Expected Interface
 // PortKeeper defines the expected IBC port keeper
 type PortKeeper interface {
@@ -189,7 +192,7 @@ func (am AppModule) OnChanCloseConfirm(sdk.Context, string, string) error {
 }
 
 // OnRecvPacket implements the IBCModule interface.
-func (am AppModule) OnRecvPacket(ctx sdk.Context, packet channeltypes.Packet) exported.Acknowledgement {
+func (am AppModule) OnRecvPacket(ctx sdk.Context, packet channeltypes.Packet, relayer sdk.AccAddress) exported.Acknowledgement {
 	// set state by claiming capability to check if revert happens return
 	am.scopedKeeper.NewCapability(ctx, MockCanaryCapabilityName)
 	if bytes.Equal(MockPacketData, packet.GetData()) {
@@ -202,11 +205,11 @@ func (am AppModule) OnRecvPacket(ctx sdk.Context, packet channeltypes.Packet) ex
 }
 
 // OnAcknowledgementPacket implements the IBCModule interface.
-func (am AppModule) OnAcknowledgementPacket(sdk.Context, channeltypes.Packet, []byte) (*sdk.Result, error) {
+func (am AppModule) OnAcknowledgementPacket(sdk.Context, channeltypes.Packet, []byte, sdk.AccAddress) (*sdk.Result, error) {
 	return nil, nil
 }
 
 // OnTimeoutPacket implements the IBCModule interface.
-func (am AppModule) OnTimeoutPacket(sdk.Context, channeltypes.Packet) (*sdk.Result, error) {
+func (am AppModule) OnTimeoutPacket(sdk.Context, channeltypes.Packet, sdk.AccAddress) (*sdk.Result, error) {
 	return nil, nil
 }