core: add testnet create and precompile hook (#607)

Early day in development, when developing for hardfork, some testnet blocks were
created with development code and not compatible with the current master code.
This commit adds testnet hooks to handle testnet bad blocks, makes the code
compatible with testnet data.

core/blockchain.go

@@ -288,6 +288,11 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 		blobSidecarsCache: blobSidecarsCache,
 		blobPrunePeriod:   params.BlobPrunePeriod,
 	}
+
+	if chainConfig.ChainID != nil && chainConfig.ChainID.Cmp(big.NewInt(testnetChainId)) == 0 {
+		bc.evmHook = TestnetHook{}
+	}
+
 	bc.validator = NewBlockValidator(chainConfig, bc, engine)
 	bc.prefetcher = newStatePrefetcher(chainConfig, bc, engine)
 	bc.processor = NewStateProcessor(chainConfig, bc, engine)

core/testnet_quirks.go

@@ -0,0 +1,107 @@
+package core
+
+import (
+	"errors"
+	"sort"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+const (
+	testnetChainId = 2021
+)
+
+type blacklistedAddress struct{}
+
+func (c *blacklistedAddress) RequiredGas(input []byte) uint64 {
+	return params.CallValueTransferGas + params.SloadGas*2
+}
+
+func (c *blacklistedAddress) Run(input []byte) ([]byte, error) {
+	return nil, errors.New("address is blacklisted")
+}
+
+type TestnetHook struct{}
+
+func (h TestnetHook) PrecompileHook(evm *vm.EVM, addr common.Address) (bool, vm.PrecompiledContract, bool) {
+	var (
+		badBlocks = []int64{
+			3312683,
+			3315192,
+			3315194,
+			3315196,
+			3315198,
+		}
+		blacklistAddress = common.HexToAddress("0x3a3012ec6812a00811A435c47eD79346318c8C92")
+	)
+
+	blockNumber := evm.Context.BlockNumber.Int64()
+	index := sort.Search(len(badBlocks), func(i int) bool { return badBlocks[i] >= blockNumber })
+
+	if index < len(badBlocks) && badBlocks[index] == blockNumber {
+		if blacklistAddress == addr {
+			return true, &blacklistedAddress{}, true
+		}
+	}
+
+	return false, nil, false
+}
+
+func (h TestnetHook) CreateHook(evm *vm.EVM, gas uint64, addr common.Address) (bool, []byte, common.Address, uint64, error) {
+	var (
+		badBlocks = []int64{
+			3281085,
+			3283414,
+			3283446,
+			3283452,
+			3283454,
+			3283456,
+			3283458,
+			3284174,
+			3284176,
+			3284178,
+			3284180,
+			3284188,
+			3284190,
+			3284275,
+			3284277,
+			3284279,
+			3284281,
+			3284307,
+			3284309,
+			3284311,
+			3284313,
+			3284617,
+			3284619,
+			3284621,
+			3284623,
+			3284752,
+			3284754,
+			3284756,
+			3284758,
+			3285191,
+			3285193,
+			3285195,
+			3285197,
+			3285607,
+			3285609,
+			3285611,
+			3285613,
+		}
+
+		blacklistAddress = common.HexToAddress("0x4e59b44847b379578588920ca78fbf26c0b4956c")
+	)
+
+	blockNumber := evm.Context.BlockNumber.Int64()
+	index := sort.Search(len(badBlocks), func(i int) bool { return badBlocks[i] >= blockNumber })
+
+	if index < len(badBlocks) && badBlocks[index] == blockNumber {
+		if addr == blacklistAddress {
+			return true, nil, common.Address{}, gas, vm.ErrExecutionReverted
+		}
+	}
+
+	return false, nil, common.Address{}, 0, nil
+}