les: limit state ODR retrievals to the last 100 blocks (ethereum#17744)

les/fetcher.go

@@ -32,8 +32,9 @@ import (
 )
 
 const (
-	blockDelayTimeout = time.Second * 10 // timeout for a peer to announce a head that has already been confirmed by others
-	maxNodeCount      = 20               // maximum number of fetcherTreeNode entries remembered for each peer
+	blockDelayTimeout    = time.Second * 10 // timeout for a peer to announce a head that has already been confirmed by others
+	maxNodeCount         = 20               // maximum number of fetcherTreeNode entries remembered for each peer
+	serverStateAvailable = 100              // number of recent blocks where state availability is assumed
 )
 
 // lightFetcher implements retrieval of newly announced headers. It also provides a peerHasBlock function for the
@@ -215,8 +216,8 @@ func (f *lightFetcher) syncLoop() {
 // registerPeer adds a new peer to the fetcher's peer set
 func (f *lightFetcher) registerPeer(p *peer) {
 	p.lock.Lock()
-	p.hasBlock = func(hash common.Hash, number uint64) bool {
-		return f.peerHasBlock(p, hash, number)
+	p.hasBlock = func(hash common.Hash, number uint64, hasState bool) bool {
+		return f.peerHasBlock(p, hash, number, hasState)
 	}
 	p.lock.Unlock()
 
@@ -344,21 +345,27 @@ func (f *lightFetcher) announce(p *peer, head *announceData) {
 
 // peerHasBlock returns true if we can assume the peer knows the given block
 // based on its announcements
-func (f *lightFetcher) peerHasBlock(p *peer, hash common.Hash, number uint64) bool {
+func (f *lightFetcher) peerHasBlock(p *peer, hash common.Hash, number uint64, hasState bool) bool {
 	f.lock.Lock()
 	defer f.lock.Unlock()
 
+	fp := f.peers[p]
+	if fp == nil || fp.root == nil {
+		return false
+	}
+
+	if hasState {
+		if fp.lastAnnounced == nil || fp.lastAnnounced.number > number+serverStateAvailable {
+			return false
+		}
+	}
+
 	if f.syncing {
 		// always return true when syncing
 		// false positives are acceptable, a more sophisticated condition can be implemented later
 		return true
 	}
 
-	fp := f.peers[p]
-	if fp == nil || fp.root == nil {
-		return false
-	}
-
 	if number >= fp.root.number {
 		// it is recent enough that if it is known, is should be in the peer's block tree
 		return fp.nodeByHash[hash] != nil

les/odr_requests.go

@@ -84,7 +84,7 @@ func (r *BlockRequest) GetCost(peer *peer) uint64 {
 
 // CanSend tells if a certain peer is suitable for serving the given request
 func (r *BlockRequest) CanSend(peer *peer) bool {
-	return peer.HasBlock(r.Hash, r.Number)
+	return peer.HasBlock(r.Hash, r.Number, false)
 }
 
 // Request sends an ODR request to the LES network (implementation of LesOdrRequest)
@@ -140,7 +140,7 @@ func (r *ReceiptsRequest) GetCost(peer *peer) uint64 {
 
 // CanSend tells if a certain peer is suitable for serving the given request
 func (r *ReceiptsRequest) CanSend(peer *peer) bool {
-	return peer.HasBlock(r.Hash, r.Number)
+	return peer.HasBlock(r.Hash, r.Number, false)
 }
 
 // Request sends an ODR request to the LES network (implementation of LesOdrRequest)
@@ -202,7 +202,7 @@ func (r *TrieRequest) GetCost(peer *peer) uint64 {
 
 // CanSend tells if a certain peer is suitable for serving the given request
 func (r *TrieRequest) CanSend(peer *peer) bool {
-	return peer.HasBlock(r.Id.BlockHash, r.Id.BlockNumber)
+	return peer.HasBlock(r.Id.BlockHash, r.Id.BlockNumber, true)
 }
 
 // Request sends an ODR request to the LES network (implementation of LesOdrRequest)
@@ -272,7 +272,7 @@ func (r *CodeRequest) GetCost(peer *peer) uint64 {
 
 // CanSend tells if a certain peer is suitable for serving the given request
 func (r *CodeRequest) CanSend(peer *peer) bool {
-	return peer.HasBlock(r.Id.BlockHash, r.Id.BlockNumber)
+	return peer.HasBlock(r.Id.BlockHash, r.Id.BlockNumber, true)
 }
 
 // Request sends an ODR request to the LES network (implementation of LesOdrRequest)

les/odr_test.go

@@ -194,7 +194,7 @@ func testOdr(t *testing.T, protocol int, expFail uint64, fn odrTestFn) {
 	client.peers.Register(client.rPeer)
 	time.Sleep(time.Millisecond * 10) // ensure that all peerSetNotify callbacks are executed
 	client.peers.lock.Lock()
-	client.rPeer.hasBlock = func(common.Hash, uint64) bool { return true }
+	client.rPeer.hasBlock = func(common.Hash, uint64, bool) bool { return true }
 	client.peers.lock.Unlock()
 	test(5)
 	// still expect all retrievals to pass, now data should be cached locally

les/peer.go

@@ -67,7 +67,7 @@ type peer struct {
 	sendQueue   *execQueue
 
 	poolEntry      *poolEntry
-	hasBlock       func(common.Hash, uint64) bool
+	hasBlock       func(common.Hash, uint64, bool) bool
 	responseErrors int
 
 	fcClient       *flowcontrol.ClientNode // nil if the peer is server only
@@ -171,11 +171,11 @@ func (p *peer) GetRequestCost(msgcode uint64, amount int) uint64 {
 }
 
 // HasBlock checks if the peer has a given block
-func (p *peer) HasBlock(hash common.Hash, number uint64) bool {
+func (p *peer) HasBlock(hash common.Hash, number uint64, hasState bool) bool {
 	p.lock.RLock()
 	hasBlock := p.hasBlock
 	p.lock.RUnlock()
-	return hasBlock != nil && hasBlock(hash, number)
+	return hasBlock != nil && hasBlock(hash, number, hasState)
 }
 
 // SendAnnounce announces the availability of a number of blocks through

les/request_test.go

@@ -115,7 +115,7 @@ func testAccess(t *testing.T, protocol int, fn accessTestFn) {
 	client.peers.Register(client.rPeer)
 	time.Sleep(time.Millisecond * 10) // ensure that all peerSetNotify callbacks are executed
 	client.rPeer.lock.Lock()
-	client.rPeer.hasBlock = func(common.Hash, uint64) bool { return true }
+	client.rPeer.hasBlock = func(common.Hash, uint64, bool) bool { return true }
 	client.rPeer.lock.Unlock()
 	// expect all retrievals to pass
 	test(5)