eth: make transaction propagation paths in the network deterministic (#29034)

* eth: make transaction propagation paths in the network deterministic

* eth: avoid potential division by 0

* eth: make tx propagation dependent on local node id too

* eth: fix review comments
pull/29151/head
Péter Szilágyi 8 months ago committed by GitHub
parent 0a2f33946b
commit 0b1438c3df
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
  1. 1
      eth/backend.go
  2. 57
      eth/handler.go

@ -236,6 +236,7 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
// Permit the downloader to use the trie cache allowance during fast sync
cacheLimit := cacheConfig.TrieCleanLimit + cacheConfig.TrieDirtyLimit + cacheConfig.SnapshotLimit
if eth.handler, err = newHandler(&handlerConfig{
NodeID: eth.p2pServer.Self().ID(),
Database: chainDb,
Chain: eth.blockchain,
TxPool: eth.txPool,

@ -32,6 +32,7 @@ import (
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/txpool"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/eth/downloader"
"github.com/ethereum/go-ethereum/eth/fetcher"
"github.com/ethereum/go-ethereum/eth/protocols/eth"
@ -41,7 +42,9 @@ import (
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/triedb/pathdb"
"golang.org/x/crypto/sha3"
)
const (
@ -84,6 +87,7 @@ type txPool interface {
// handlerConfig is the collection of initialization parameters to create a full
// node network handler.
type handlerConfig struct {
NodeID enode.ID // P2P node ID used for tx propagation topology
Database ethdb.Database // Database for direct sync insertions
Chain *core.BlockChain // Blockchain to serve data from
TxPool txPool // Transaction pool to propagate from
@ -96,6 +100,7 @@ type handlerConfig struct {
}
type handler struct {
nodeID enode.ID
networkID uint64
forkFilter forkid.Filter // Fork ID filter, constant across the lifetime of the node
@ -137,6 +142,7 @@ func newHandler(config *handlerConfig) (*handler, error) {
config.EventMux = new(event.TypeMux) // Nicety initialization for tests
}
h := &handler{
nodeID: config.NodeID,
networkID: config.Network,
forkFilter: forkid.NewFilter(config.Chain),
eventMux: config.EventMux,
@ -614,25 +620,54 @@ func (h *handler) BroadcastTransactions(txs types.Transactions) {
annos = make(map[*ethPeer][]common.Hash) // Set peer->hash to announce
)
// Broadcast transactions to a batch of peers not knowing about it
for _, tx := range txs {
peers := h.peers.peersWithoutTransaction(tx.Hash())
direct := big.NewInt(int64(math.Sqrt(float64(h.peers.len())))) // Approximate number of peers to broadcast to
if direct.BitLen() == 0 {
direct = big.NewInt(1)
}
total := new(big.Int).Exp(direct, big.NewInt(2), nil) // Stabilise total peer count a bit based on sqrt peers
var numDirect int
var (
signer = types.LatestSignerForChainID(h.chain.Config().ChainID) // Don't care about chain status, we just need *a* sender
hasher = sha3.NewLegacyKeccak256().(crypto.KeccakState)
hash = make([]byte, 32)
)
for _, tx := range txs {
var maybeDirect bool
switch {
case tx.Type() == types.BlobTxType:
blobTxs++
case tx.Size() > txMaxBroadcastSize:
largeTxs++
default:
numDirect = int(math.Sqrt(float64(len(peers))))
maybeDirect = true
}
// Send the tx unconditionally to a subset of our peers
for _, peer := range peers[:numDirect] {
txset[peer] = append(txset[peer], tx.Hash())
}
// For the remaining peers, send announcement only
for _, peer := range peers[numDirect:] {
annos[peer] = append(annos[peer], tx.Hash())
// Send the transaction (if it's small enough) directly to a subset of
// the peers that have not received it yet, ensuring that the flow of
// transactions is groupped by account to (try and) avoid nonce gaps.
//
// To do this, we hash the local enode IW with together with a peer's
// enode ID together with the transaction sender and broadcast if
// `sha(self, peer, sender) mod peers < sqrt(peers)`.
for _, peer := range h.peers.peersWithoutTransaction(tx.Hash()) {
var broadcast bool
if maybeDirect {
hasher.Reset()
hasher.Write(h.nodeID.Bytes())
hasher.Write(peer.Node().ID().Bytes())
from, _ := types.Sender(signer, tx) // Ignore error, we only use the addr as a propagation target splitter
hasher.Write(from.Bytes())
hasher.Read(hash)
if new(big.Int).Mod(new(big.Int).SetBytes(hash), total).Cmp(direct) < 0 {
broadcast = true
}
}
if broadcast {
txset[peer] = append(txset[peer], tx.Hash())
} else {
annos[peer] = append(annos[peer], tx.Hash())
}
}
}
for peer, hashes := range txset {

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