add CheckCaller

x/evm/keeper/precompiles/bank.go

@@ -3,8 +3,6 @@ package precompiles
 import (
  "errors"
  "math/big"
- "runtime"
- "strings"
 
  sdkmath "cosmossdk.io/math"
  "github.com/ethereum/go-ethereum/accounts/abi"
@@ -90,23 +88,9 @@ func (bc *BankContract) RequiredGas(input []byte) uint64 {
 }
 
 func (bc *BankContract) Run(input []byte) ([]byte, error) {
- layer := 2
- pc, _, _, _ := runtime.Caller(layer)
- prefix := "github.com/ethereum/go-ethereum/core/vm.(*EVM)."
- caller := runtime.FuncForPC(pc).Name()
- readonly := false
- if strings.Index(caller, prefix) == 0 {
- fn := caller[len(prefix):]
- switch fn {
- case "Call":
- readonly = false
- case "CallCode":
- case "DelegateCall":
- case "StaticCall":
- readonly = true
- default:
- return nil, errors.New("unknown caller")
- }
+ readonly, err := CheckCaller()
+ if err != nil {
+ return nil, err
  }
  // parse input
  methodID := input[:4]
@@ -147,8 +131,8 @@ func (bc *BankContract) Run(input []byte) ([]byte, error) {
  token := args[0].(common.Address)
  addr := args[1].(common.Address)
  // query from storage
- amount := bc.bankKeeper.GetBalance(bc.ctx, sdk.AccAddress(addr.Bytes()), EVMDenom(token)).Amount.BigInt()
- return BalanceOfMethod.Outputs.Pack(amount)
+ balance := bc.bankKeeper.GetBalance(bc.ctx, sdk.AccAddress(addr.Bytes()), EVMDenom(token)).Amount.BigInt()
+ return BalanceOfMethod.Outputs.Pack(balance)
  default:
  return nil, errors.New("unknown method")
  }

x/evm/keeper/precompiles/utils.go

@@ -0,0 +1,29 @@
+package precompiles
+
+import (
+ "errors"
+ "runtime"
+ "strings"
+)
+
+func CheckCaller() (bool, error) {
+ layer := 2
+ pc, _, _, _ := runtime.Caller(layer)
+ prefix := "github.com/ethereum/go-ethereum/core/vm.(*EVM)."
+ caller := runtime.FuncForPC(pc).Name()
+ readonly := false
+ if strings.Index(caller, prefix) == 0 {
+ fn := caller[len(prefix):]
+ switch fn {
+ case "Call":
+ readonly = false
+ case "CallCode":
+ case "DelegateCall":
+ case "StaticCall":
+ readonly = true
+ default:
+ return readonly, errors.New("unknown caller")
+ }
+ }
+ return readonly, nil
+}