feat: make cross-chain token mintable

proto/cosmos/crosschain/v1/tx.proto

@@ -23,6 +23,10 @@ service Msg {
   // UpdateChannelPermissions defines a governance operation for updating the channel permissions.
   // The authority is defined in the keeper.
   rpc UpdateChannelPermissions(MsgUpdateChannelPermissions) returns (MsgUpdateChannelPermissionsResponse);
+
+  // MintModuleTokens defines a governance operation for minting tokens for the crosschain module.
+  // The authority is defined in the keeper.
+  rpc MintModuleTokens(MsgMintModuleTokens) returns (MsgMintModuleTokensResponse);
 }
 
 // MsgUpdateParams is the Msg/UpdateParams request type.
@@ -55,4 +59,25 @@ message MsgUpdateChannelPermissions {
 
 // MsgUpdateChannelPermissionsResponse defines the response structure for executing a
 // MsgUpdateChannelPermissions message.
-message MsgUpdateChannelPermissionsResponse {}
+message MsgUpdateChannelPermissionsResponse {}
+
+// MsgMintModuleTokens is the Msg/MintModuleTokens request type.
+// The Msg is used to mint tokens for the crosschain module.
+// This Only permitted to be called by the authority(gov).
+message MsgMintModuleTokens {
+  option (cosmos.msg.v1.signer) = "authority";
+
+  // authority is the address that controls the module (defaults to x/gov unless overwritten).
+  string authority = 1 [(cosmos_proto.scalar) = "cosmos.AddressString"];
+
+  // initial balance to mint for crosschain module when the chain starts
+  string amount = 2 [
+    (cosmos_proto.scalar)  = "math.Int",
+    (gogoproto.customtype) = "cosmossdk.io/math.Int",
+    (gogoproto.nullable)   = false
+  ];
+}
+
+// MsgMintModuleTokensResponse defines the response structure for executing a
+// MsgMintModuleTokens message.
+message MsgMintModuleTokensResponse {}

x/crosschain/keeper/keeper.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"math/big"
 
+	"cosmossdk.io/math"
 	"github.com/cometbft/cometbft/libs/log"
 
 	"github.com/cosmos/cosmos-sdk/codec"
@@ -22,17 +23,24 @@ type Keeper struct {
 	storeKey storetypes.StoreKey
 
 	authority string
+
+	stakingKeeper types.StakingKeeper
+	bankKeeper    types.BankKeeper
 }
 
 // NewKeeper creates a new mint Keeper instance
 func NewKeeper(
 	cdc codec.BinaryCodec, key storetypes.StoreKey, authority string,
+	stakingKeeper types.StakingKeeper,
+	bankKeeper types.BankKeeper,
 ) Keeper {
 	return Keeper{
-		cdc:       cdc,
-		storeKey:  key,
-		cfg:       newCrossChainCfg(),
-		authority: authority,
+		cdc:           cdc,
+		storeKey:      key,
+		cfg:           newCrossChainCfg(),
+		authority:     authority,
+		stakingKeeper: stakingKeeper,
+		bankKeeper:    bankKeeper,
 	}
 }
 
@@ -293,3 +301,15 @@ func (k Keeper) incrSequence(ctx sdk.Context, destChainID sdk.ChainID, channelID
 func (k Keeper) GetCrossChainApp(channelID sdk.ChannelID) sdk.CrossChainApplication {
 	return k.cfg.channelIDToApp[channelID]
 }
+
+func (k Keeper) MintModuleAccountTokens(ctx sdk.Context, amount math.Int) error {
+	bondDenom := k.stakingKeeper.BondDenom(ctx)
+	err := k.bankKeeper.MintCoins(ctx, types.ModuleName, sdk.Coins{sdk.Coin{
+		Denom:  bondDenom,
+		Amount: amount,
+	}})
+	if err != nil {
+		return fmt.Errorf("mint cross chain module amount error, err=%s", err.Error())
+	}
+	return nil
+}

x/crosschain/keeper/keeper_test.go

@@ -3,6 +3,9 @@ package keeper_test
 import (
 	"testing"
 
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/suite"
+
 	"github.com/cosmos/cosmos-sdk/baseapp"
 	storetypes "github.com/cosmos/cosmos-sdk/store/types"
 	"github.com/cosmos/cosmos-sdk/testutil"
@@ -12,8 +15,8 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/crosschain/keeper"
 	testutil2 "github.com/cosmos/cosmos-sdk/x/crosschain/testutil"
 	"github.com/cosmos/cosmos-sdk/x/crosschain/types"
+	govtestutil "github.com/cosmos/cosmos-sdk/x/gov/testutil"
 	"github.com/cosmos/cosmos-sdk/x/mint"
-	"github.com/stretchr/testify/suite"
 )
 
 type TestSuite struct {
@@ -31,11 +34,16 @@ func (s *TestSuite) SetupTest() {
 	key := storetypes.NewKVStoreKey(types.StoreKey)
 	testCtx := testutil.DefaultContextWithDB(s.T(), key, storetypes.NewTransientStoreKey("transient_test"))
 	s.ctx = testCtx.Ctx
-
+	// gomock initializations
+	ctrl := gomock.NewController(s.T())
+	bankKeeper := govtestutil.NewMockBankKeeper(ctrl)
+	stakingKeeper := govtestutil.NewMockStakingKeeper(ctrl)
 	s.crossChainKeeper = keeper.NewKeeper(
 		encCfg.Codec,
 		key,
 		authtypes.NewModuleAddress(types.ModuleName).String(),
+		stakingKeeper,
+		bankKeeper,
 	)
 
 	err := s.crossChainKeeper.SetParams(s.ctx, types.DefaultParams())

x/crosschain/keeper/msg_server.go

@@ -46,3 +46,16 @@ func (k msgServer) UpdateChannelPermissions(goCtx context.Context, req *types.Ms
 
 	return &types.MsgUpdateChannelPermissionsResponse{}, nil
 }
+
+func (k msgServer) MintModuleTokens(goCtx context.Context, req *types.MsgMintModuleTokens) (*types.MsgMintModuleTokensResponse, error) {
+	if k.GetAuthority() != req.Authority {
+		return nil, errorsmod.Wrapf(govtypes.ErrInvalidSigner, "invalid authority; expected %s, got %s", k.GetAuthority(), req.Authority)
+	}
+
+	ctx := sdk.UnwrapSDKContext(goCtx)
+	if err := k.MintModuleAccountTokens(ctx, req.Amount); err != nil {
+		return nil, err
+	}
+
+	return &types.MsgMintModuleTokensResponse{}, nil
+}

x/crosschain/module.go

@@ -178,6 +178,8 @@ func ProvideModule(in CrossChainInputs) CrossChainOutputs {
 		in.Cdc,
 		in.Key,
 		authority.String(),
+		in.StakingKeeper,
+		in.BankKeeper,
 	)
 
 	m := NewAppModule(k, in.BankKeeper, in.StakingKeeper)

x/crosschain/types/msgs.go

@@ -7,7 +7,11 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
 
-var _ sdk.Msg = &MsgUpdateParams{}
+var (
+	_ sdk.Msg = &MsgUpdateParams{}
+	_ sdk.Msg = &MsgUpdateChannelPermissions{}
+	_ sdk.Msg = &MsgMintModuleTokens{}
+)
 
 // GetSignBytes implements the LegacyMsg interface.
 func (m MsgUpdateParams) GetSignBytes() []byte {
@@ -58,3 +62,27 @@ func (m *MsgUpdateChannelPermissions) ValidateBasic() error {
 
 	return nil
 }
+
+// GetSignBytes implements the LegacyMsg interface.
+func (m MsgMintModuleTokens) GetSignBytes() []byte {
+	return sdk.MustSortJSON(ModuleCdc.MustMarshalJSON(&m))
+}
+
+// GetSigners returns the expected signers for a MsgMintModuleTokens message.
+func (m *MsgMintModuleTokens) GetSigners() []sdk.AccAddress {
+	addr, _ := sdk.AccAddressFromHexUnsafe(m.Authority)
+	return []sdk.AccAddress{addr}
+}
+
+// ValidateBasic does a sanity check on the provided data.
+func (m *MsgMintModuleTokens) ValidateBasic() error {
+	if _, err := sdk.AccAddressFromHexUnsafe(m.Authority); err != nil {
+		return errorsmod.Wrap(err, "invalid authority address")
+	}
+
+	if m.Amount.LTE(sdk.ZeroInt()) {
+		return fmt.Errorf("amount must be positive, is %s", m.Amount)
+	}
+
+	return nil
+}