swarm/network: light nodes are not dialed, saved and requested from (#17975)

* RequestFromPeers does not use peers marked as lightnode

* fix warning about variable name

* write tests for RequestFromPeers

* lightnodes should be omitted from the addressbook

* resolve pr comments regarding logging, formatting and comments

* resolve pr comments regarding comments and added a missing newline

* add assertions to check peers in live connections

swarm/network/stream/delivery.go

@@ -245,7 +245,10 @@ func (d *Delivery) RequestFromPeers(ctx context.Context, req *network.Request) (
 	} else {
 		d.kad.EachConn(req.Addr[:], 255, func(p *network.Peer, po int, nn bool) bool {
 			id := p.ID()
-			// TODO: skip light nodes that do not accept retrieve requests
+			if p.LightNode {
+				// skip light nodes
+				return true
+			}
 			if req.SkipPeer(id.String()) {
 				log.Trace("Delivery.RequestFromPeers: skip peer", "peer id", id)
 				return true

swarm/network/stream/delivery_test.go

@@ -29,10 +29,13 @@ import (
 
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/ethereum/go-ethereum/p2p/protocols"
 	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
 	p2ptest "github.com/ethereum/go-ethereum/p2p/testing"
 	"github.com/ethereum/go-ethereum/swarm/log"
 	"github.com/ethereum/go-ethereum/swarm/network"
+	pq "github.com/ethereum/go-ethereum/swarm/network/priorityqueue"
 	"github.com/ethereum/go-ethereum/swarm/network/simulation"
 	"github.com/ethereum/go-ethereum/swarm/state"
 	"github.com/ethereum/go-ethereum/swarm/storage"
@@ -274,6 +277,86 @@ func TestStreamerUpstreamRetrieveRequestMsgExchange(t *testing.T) {
 	}
 }
 
+// if there is one peer in the Kademlia, RequestFromPeers should return it
+func TestRequestFromPeers(t *testing.T) {
+	dummyPeerID := enode.HexID("3431c3939e1ee2a6345e976a8234f9870152d64879f30bc272a074f6859e75e8")
+
+	addr := network.RandomAddr()
+	to := network.NewKademlia(addr.OAddr, network.NewKadParams())
+	delivery := NewDelivery(to, nil)
+	protocolsPeer := protocols.NewPeer(p2p.NewPeer(dummyPeerID, "dummy", nil), nil, nil)
+	peer := network.NewPeer(&network.BzzPeer{
+		BzzAddr:   network.RandomAddr(),
+		LightNode: false,
+		Peer:      protocolsPeer,
+	}, to)
+	to.On(peer)
+	r := NewRegistry(addr.ID(), delivery, nil, nil, nil)
+
+	// an empty priorityQueue has to be created to prevent a goroutine being called after the test has finished
+	sp := &Peer{
+		Peer:     protocolsPeer,
+		pq:       pq.New(int(PriorityQueue), PriorityQueueCap),
+		streamer: r,
+	}
+	r.setPeer(sp)
+	req := network.NewRequest(
+		storage.Address(hash0[:]),
+		true,
+		&sync.Map{},
+	)
+	ctx := context.Background()
+	id, _, err := delivery.RequestFromPeers(ctx, req)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+	if *id != dummyPeerID {
+		t.Fatalf("Expected an id, got %v", id)
+	}
+}
+
+// RequestFromPeers should not return light nodes
+func TestRequestFromPeersWithLightNode(t *testing.T) {
+	dummyPeerID := enode.HexID("3431c3939e1ee2a6345e976a8234f9870152d64879f30bc272a074f6859e75e8")
+
+	addr := network.RandomAddr()
+	to := network.NewKademlia(addr.OAddr, network.NewKadParams())
+	delivery := NewDelivery(to, nil)
+
+	protocolsPeer := protocols.NewPeer(p2p.NewPeer(dummyPeerID, "dummy", nil), nil, nil)
+	// setting up a lightnode
+	peer := network.NewPeer(&network.BzzPeer{
+		BzzAddr:   network.RandomAddr(),
+		LightNode: true,
+		Peer:      protocolsPeer,
+	}, to)
+	to.On(peer)
+	r := NewRegistry(addr.ID(), delivery, nil, nil, nil)
+	// an empty priorityQueue has to be created to prevent a goroutine being called after the test has finished
+	sp := &Peer{
+		Peer:     protocolsPeer,
+		pq:       pq.New(int(PriorityQueue), PriorityQueueCap),
+		streamer: r,
+	}
+	r.setPeer(sp)
+
+	req := network.NewRequest(
+		storage.Address(hash0[:]),
+		true,
+		&sync.Map{},
+	)
+
+	ctx := context.Background()
+	// making a request which should return with "no peer found"
+	_, _, err := delivery.RequestFromPeers(ctx, req)
+
+	expectedError := "no peer found"
+	if err.Error() != expectedError {
+		t.Fatalf("expected '%v', got %v", expectedError, err)
+	}
+}
+
 func TestStreamerDownstreamChunkDeliveryMsgExchange(t *testing.T) {
 	tester, streamer, localStore, teardown, err := newStreamerTester(t, &RegistryOptions{
 		Retrieval: RetrievalDisabled,