core/txpool: disallow future churn by remote txs (#26907)

Prior to this change, it was possible that transactions are erroneously deemed as 'future' although they are in fact 'pending', causing them to be dropped due to 'future' not being allowed to replace 'pending'. 

This change fixes that, by doing a more in-depth inspection of the queue.
This commit is contained in:
Marius van der Wijden 2023-04-05 10:59:32 +02:00 committed by GitHub
parent 2adce0b066
commit 230df98e4d
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 51 additions and 19 deletions

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@ -270,10 +270,10 @@ func newList(strict bool) *list {
}
}
// Overlaps returns whether the transaction specified has the same nonce as one
// already contained within the list.
func (l *list) Overlaps(tx *types.Transaction) bool {
return l.txs.Get(tx.Nonce()) != nil
// Contains returns whether the list contains a transaction
// with the provided nonce.
func (l *list) Contains(nonce uint64) bool {
return l.txs.Get(nonce) != nil
}
// Add tries to insert a new transaction into the list, returning whether the

View File

@ -745,11 +745,11 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (replaced bool, err e
}
// If the new transaction is a future transaction it should never churn pending transactions
if !isLocal && pool.isFuture(from, tx) {
if !isLocal && pool.isGapped(from, tx) {
var replacesPending bool
for _, dropTx := range drop {
dropSender, _ := types.Sender(pool.signer, dropTx)
if list := pool.pending[dropSender]; list != nil && list.Overlaps(dropTx) {
if list := pool.pending[dropSender]; list != nil && list.Contains(dropTx.Nonce()) {
replacesPending = true
break
}
@ -774,7 +774,7 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (replaced bool, err e
}
// Try to replace an existing transaction in the pending pool
if list := pool.pending[from]; list != nil && list.Overlaps(tx) {
if list := pool.pending[from]; list != nil && list.Contains(tx.Nonce()) {
// Nonce already pending, check if required price bump is met
inserted, old := list.Add(tx, pool.config.PriceBump)
if !inserted {
@ -817,18 +817,26 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (replaced bool, err e
return replaced, nil
}
// isFuture reports whether the given transaction is immediately executable.
func (pool *TxPool) isFuture(from common.Address, tx *types.Transaction) bool {
list := pool.pending[from]
if list == nil {
return pool.pendingNonces.get(from) != tx.Nonce()
// isGapped reports whether the given transaction is immediately executable.
func (pool *TxPool) isGapped(from common.Address, tx *types.Transaction) bool {
// Short circuit if transaction matches pending nonce and can be promoted
// to pending list as an executable transaction.
next := pool.pendingNonces.get(from)
if tx.Nonce() == next {
return false
}
// Sender has pending transactions.
if old := list.txs.Get(tx.Nonce()); old != nil {
return false // It replaces a pending transaction.
// The transaction has a nonce gap with pending list, it's only considered
// as executable if transactions in queue can fill up the nonce gap.
queue, ok := pool.queue[from]
if !ok {
return true
}
// Not replacing, check if parent nonce exists in pending.
return list.txs.Get(tx.Nonce()-1) == nil
for nonce := next; nonce < tx.Nonce(); nonce++ {
if !queue.Contains(nonce) {
return true // txs in queue can't fill up the nonce gap
}
}
return false
}
// enqueueTx inserts a new transaction into the non-executable transaction queue.

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@ -42,7 +42,7 @@ func count(t *testing.T, pool *TxPool) (pending int, queued int) {
return pending, queued
}
func fillPool(t *testing.T, pool *TxPool) {
func fillPool(t testing.TB, pool *TxPool) {
t.Helper()
// Create a number of test accounts, fund them and make transactions
executableTxs := types.Transactions{}
@ -189,7 +189,7 @@ func TestTransactionZAttack(t *testing.T) {
key, _ := crypto.GenerateKey()
pool.currentState.AddBalance(crypto.PubkeyToAddress(key.PublicKey), big.NewInt(100000000000))
for j := 0; j < int(pool.config.GlobalSlots); j++ {
overDraftTxs = append(overDraftTxs, pricedValuedTransaction(uint64(j), 60000000000, 21000, big.NewInt(500), key))
overDraftTxs = append(overDraftTxs, pricedValuedTransaction(uint64(j), 600000000000, 21000, big.NewInt(500), key))
}
}
pool.AddRemotesSync(overDraftTxs)
@ -210,3 +210,27 @@ func TestTransactionZAttack(t *testing.T) {
newIvPending, ivPending, pool.config.GlobalSlots, newQueued)
}
}
func BenchmarkFutureAttack(b *testing.B) {
// Create the pool to test the limit enforcement with
statedb, _ := state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
blockchain := newTestBlockChain(1000000, statedb, new(event.Feed))
config := testTxPoolConfig
config.GlobalQueue = 100
config.GlobalSlots = 100
pool := NewTxPool(config, eip1559Config, blockchain)
defer pool.Stop()
fillPool(b, pool)
key, _ := crypto.GenerateKey()
pool.currentState.AddBalance(crypto.PubkeyToAddress(key.PublicKey), big.NewInt(100000000000))
futureTxs := types.Transactions{}
for n := 0; n < b.N; n++ {
futureTxs = append(futureTxs, pricedTransaction(1000+uint64(n), 100000, big.NewInt(500), key))
}
b.ResetTimer()
for i := 0; i < 5; i++ {
pool.AddRemotesSync(futureTxs)
}
}