83 lines
2.8 KiB
Go
83 lines
2.8 KiB
Go
|
package ante
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
|
||
|
|
sdk "github.com/cosmos/cosmos-sdk/types"
|
||
|
|
sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
|
||
|
|
authante "github.com/cosmos/cosmos-sdk/x/auth/ante"
|
||
|
|
authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
|
||
|
|
"github.com/cosmos/cosmos-sdk/x/feegrant/keeper"
|
||
|
|
"github.com/cosmos/cosmos-sdk/x/feegrant/types"
|
||
|
|
)
|
||
|
|
|
||
|
|
// DeductGrantedFeeDecorator deducts fees from fee_payer or fee_granter (if exists a valid fee allowance) of the tx
|
||
|
|
// If the fee_payer or fee_granter does not have the funds to pay for the fees, return with InsufficientFunds error
|
||
|
|
// Call next AnteHandler if fees successfully deducted
|
||
|
|
// CONTRACT: Tx must implement GrantedFeeTx interface to use DeductGrantedFeeDecorator
|
||
|
|
type DeductGrantedFeeDecorator struct {
|
||
|
|
ak types.AccountKeeper
|
||
|
|
k keeper.Keeper
|
||
|
|
bk types.BankKeeper
|
||
|
|
}
|
||
|
|
|
||
|
|
func NewDeductGrantedFeeDecorator(ak types.AccountKeeper, bk types.BankKeeper, k keeper.Keeper) DeductGrantedFeeDecorator {
|
||
|
|
return DeductGrantedFeeDecorator{
|
||
|
|
ak: ak,
|
||
|
|
k: k,
|
||
|
|
bk: bk,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// AnteHandle performs a decorated ante-handler responsible for deducting transaction
|
||
|
|
// fees. Fees will be deducted from the account designated by the FeePayer on a
|
||
|
|
// transaction by default. However, if the fee payer differs from the transaction
|
||
|
|
// signer, the handler will check if a fee grant has been authorized. If the
|
||
|
|
// transaction's signer does not exist, it will be created.
|
||
|
|
func (d DeductGrantedFeeDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
|
||
|
|
feeTx, ok := tx.(sdk.FeeTx)
|
||
|
|
if !ok {
|
||
|
|
return ctx, sdkerrors.Wrap(sdkerrors.ErrTxDecode, "Tx must be a GrantedFeeTx")
|
||
|
|
}
|
||
|
|
|
||
|
|
// sanity check from DeductFeeDecorator
|
||
|
|
if addr := d.ak.GetModuleAddress(authtypes.FeeCollectorName); addr == nil {
|
||
|
|
panic(fmt.Sprintf("%s module account has not been set", authtypes.FeeCollectorName))
|
||
|
|
}
|
||
|
|
|
||
|
|
fee := feeTx.GetFee()
|
||
|
|
feePayer := feeTx.FeePayer()
|
||
|
|
feeGranter := feeTx.FeeGranter()
|
||
|
|
|
||
|
|
deductFeesFrom := feePayer
|
||
|
|
|
||
|
|
// ensure the grant is allowed, if we request a different fee payer
|
||
|
|
if feeGranter != nil && !feeGranter.Equals(feePayer) {
|
||
|
|
err := d.k.UseGrantedFees(ctx, feeGranter, feePayer, fee)
|
||
|
|
if err != nil {
|
||
|
|
return ctx, sdkerrors.Wrapf(err, "%s not allowed to pay fees from %s", feeGranter, feePayer)
|
||
|
|
}
|
||
|
|
|
||
|
|
deductFeesFrom = feeGranter
|
||
|
|
}
|
||
|
|
|
||
|
|
// now, either way, we know that we are authorized to deduct the fees from the deductFeesFrom account
|
||
|
|
deductFeesFromAcc := d.ak.GetAccount(ctx, deductFeesFrom)
|
||
|
|
if deductFeesFromAcc == nil {
|
||
|
|
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownAddress, "fee payer address: %s does not exist", deductFeesFrom)
|
||
|
|
}
|
||
|
|
|
||
|
|
// move on if there is no fee to deduct
|
||
|
|
if fee.IsZero() {
|
||
|
|
return next(ctx, tx, simulate)
|
||
|
|
}
|
||
|
|
|
||
|
|
// deduct fee if non-zero
|
||
|
|
err = authante.DeductFees(d.bk, ctx, deductFeesFromAcc, fee)
|
||
|
|
if err != nil {
|
||
|
|
return ctx, err
|
||
|
|
}
|
||
|
|
|
||
|
|
return next(ctx, tx, simulate)
|
||
|
|
}
|