• rjl493456442's avatar
    cmd, core, eth, graphql, trie: no persisted clean trie cache file (#27525) · 59f7b289
    rjl493456442 authored
    The clean trie cache is persisted periodically, therefore Geth can
    quickly warmup the cache in next restart.
    
    However it will reduce the robustness of system. The assumption is
    held in Geth that if the parent trie node is present, then the entire
    sub-trie associated with the parent are all prensent.
    
    Imagine the scenario that Geth rewinds itself to a past block and
    restart, but Geth finds the root node of "future state" in clean
    cache then regard this state is present in disk, while is not in fact.
    
    Another example is offline pruning tool. Whenever an offline pruning
    is performed, the clean cache file has to be removed to aviod hitting
    the root node of "deleted states" in clean cache.
    
    All in all, compare with the minor performance gain, system robustness
    is something we care more.
    59f7b289
fuzz_handler.go 4.67 KB
// Copyright 2021 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package snap

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"math/big"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/consensus/ethash"
	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/core/vm"
	"github.com/ethereum/go-ethereum/eth/protocols/snap"
	"github.com/ethereum/go-ethereum/p2p"
	"github.com/ethereum/go-ethereum/p2p/enode"
	"github.com/ethereum/go-ethereum/params"
	"github.com/ethereum/go-ethereum/rlp"
	fuzz "github.com/google/gofuzz"
)

var trieRoot common.Hash

func getChain() *core.BlockChain {
	ga := make(core.GenesisAlloc, 1000)
	var a = make([]byte, 20)
	var mkStorage = func(k, v int) (common.Hash, common.Hash) {
		var kB = make([]byte, 32)
		var vB = make([]byte, 32)
		binary.LittleEndian.PutUint64(kB, uint64(k))
		binary.LittleEndian.PutUint64(vB, uint64(v))
		return common.BytesToHash(kB), common.BytesToHash(vB)
	}
	storage := make(map[common.Hash]common.Hash)
	for i := 0; i < 10; i++ {
		k, v := mkStorage(i, i)
		storage[k] = v
	}
	for i := 0; i < 1000; i++ {
		binary.LittleEndian.PutUint64(a, uint64(i+0xff))
		acc := core.GenesisAccount{Balance: big.NewInt(int64(i))}
		if i%2 == 1 {
			acc.Storage = storage
		}
		ga[common.BytesToAddress(a)] = acc
	}
	gspec := &core.Genesis{
		Config: params.TestChainConfig,
		Alloc:  ga,
	}
	_, blocks, _ := core.GenerateChainWithGenesis(gspec, ethash.NewFaker(), 2, func(i int, gen *core.BlockGen) {})
	cacheConf := &core.CacheConfig{
		TrieCleanLimit:      0,
		TrieDirtyLimit:      0,
		TrieTimeLimit:       5 * time.Minute,
		TrieCleanNoPrefetch: true,
		SnapshotLimit:       100,
		SnapshotWait:        true,
	}
	trieRoot = blocks[len(blocks)-1].Root()
	bc, _ := core.NewBlockChain(rawdb.NewMemoryDatabase(), cacheConf, gspec, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
	if _, err := bc.InsertChain(blocks); err != nil {
		panic(err)
	}
	return bc
}

type dummyBackend struct {
	chain *core.BlockChain
}

func (d *dummyBackend) Chain() *core.BlockChain                { return d.chain }
func (d *dummyBackend) RunPeer(*snap.Peer, snap.Handler) error { return nil }
func (d *dummyBackend) PeerInfo(enode.ID) interface{}          { return "Foo" }
func (d *dummyBackend) Handle(*snap.Peer, snap.Packet) error   { return nil }

type dummyRW struct {
	code       uint64
	data       []byte
	writeCount int
}

func (d *dummyRW) ReadMsg() (p2p.Msg, error) {
	return p2p.Msg{
		Code:       d.code,
		Payload:    bytes.NewReader(d.data),
		ReceivedAt: time.Now(),
		Size:       uint32(len(d.data)),
	}, nil
}

func (d *dummyRW) WriteMsg(msg p2p.Msg) error {
	d.writeCount++
	return nil
}

func doFuzz(input []byte, obj interface{}, code int) int {
	if len(input) > 1024*4 {
		return -1
	}
	bc := getChain()
	defer bc.Stop()
	backend := &dummyBackend{bc}
	fuzz.NewFromGoFuzz(input).Fuzz(obj)
	var data []byte
	switch p := obj.(type) {
	case *snap.GetTrieNodesPacket:
		p.Root = trieRoot
		data, _ = rlp.EncodeToBytes(obj)
	default:
		data, _ = rlp.EncodeToBytes(obj)
	}
	cli := &dummyRW{
		code: uint64(code),
		data: data,
	}
	peer := snap.NewFakePeer(65, "gazonk01", cli)
	err := snap.HandleMessage(backend, peer)
	switch {
	case err == nil && cli.writeCount != 1:
		panic(fmt.Sprintf("Expected 1 response, got %d", cli.writeCount))
	case err != nil && cli.writeCount != 0:
		panic(fmt.Sprintf("Expected 0 response, got %d", cli.writeCount))
	}
	return 1
}

// To run a fuzzer, do
// $ CGO_ENABLED=0 go-fuzz-build -func FuzzTrieNodes
// $ go-fuzz

func FuzzARange(input []byte) int {
	return doFuzz(input, &snap.GetAccountRangePacket{}, snap.GetAccountRangeMsg)
}
func FuzzSRange(input []byte) int {
	return doFuzz(input, &snap.GetStorageRangesPacket{}, snap.GetStorageRangesMsg)
}
func FuzzByteCodes(input []byte) int {
	return doFuzz(input, &snap.GetByteCodesPacket{}, snap.GetByteCodesMsg)
}
func FuzzTrieNodes(input []byte) int {
	return doFuzz(input, &snap.GetTrieNodesPacket{}, snap.GetTrieNodesMsg)
}