eth: check snap satelliteness, delegate drop to eth (#22235)

* eth: check snap satelliteness, delegate drop to eth

* eth: better handle eth/snap satellite relation, merge reg/unreg paths
# Conflicts:
#	eth/handler.go
#	eth/peer.go

eth/handler_eth.go

@@ -47,7 +47,7 @@ func (h *ethHandler) RunPeer(peer *eth.Peer, hand eth.Handler) error {
 
 // PeerInfo retrieves all known `eth` information about a peer.
 func (h *ethHandler) PeerInfo(id enode.ID) interface{} {
-	if p := h.peers.ethPeer(id.String()); p != nil {
+	if p := h.peers.peer(id.String()); p != nil {
 		return p.info()
 	}
 	return nil
@@ -107,7 +107,7 @@ func (h *ethHandler) Handle(peer *eth.Peer, packet eth.Packet) error {
 // handleHeaders is invoked from a peer's message handler when it transmits a batch
 // of headers for the local node to process.
 func (h *ethHandler) handleHeaders(peer *eth.Peer, headers []*types.Header) error {
-	p := h.peers.ethPeer(peer.ID())
+	p := h.peers.peer(peer.ID())
 	if p == nil {
 		return errors.New("unregistered during callback")
 	}

eth/handler_eth_test.go

@@ -574,11 +574,11 @@ func testCheckpointChallenge(t *testing.T, syncmode downloader.SyncMode, checkpo
 
 	// Verify that the remote peer is maintained or dropped
 	if drop {
-		if peers := handler.handler.peers.Len(); peers != 0 {
+		if peers := handler.handler.peers.len(); peers != 0 {
 			t.Fatalf("peer count mismatch: have %d, want %d", peers, 0)
 		}
 	} else {
-		if peers := handler.handler.peers.Len(); peers != 1 {
+		if peers := handler.handler.peers.len(); peers != 1 {
 			t.Fatalf("peer count mismatch: have %d, want %d", peers, 1)
 		}
 	}

eth/handler_snap.go

@@ -30,13 +30,15 @@ func (h *snapHandler) Chain() *core.BlockChain { return h.chain }
 
 // RunPeer is invoked when a peer joins on the `snap` protocol.
 func (h *snapHandler) RunPeer(peer *snap.Peer, hand snap.Handler) error {
-	return (*handler)(h).runSnapPeer(peer, hand)
+	return (*handler)(h).runSnapExtension(peer, hand)
 }
 
 // PeerInfo retrieves all known `snap` information about a peer.
 func (h *snapHandler) PeerInfo(id enode.ID) interface{} {
-	if p := h.peers.snapPeer(id.String()); p != nil {
-		return p.info()
+	if p := h.peers.peer(id.String()); p != nil {
+		if p.snapExt != nil {
+			return p.snapExt.info()
+		}
 	}
 	return nil
 }

eth/peer.go

@@ -40,9 +40,11 @@ type ethPeerInfo struct {
 // ethPeer is a wrapper around eth.Peer to maintain a few extra metadata.
 type ethPeer struct {
 	*eth.Peer
-	syncDrop *time.Timer  // Connection dropper if `eth` sync progress isn't validated in time
+	snapExt *snapPeer // Satellite `snap` connection
 
-	lock     sync.RWMutex // Mutex protecting the internal fields
+	syncDrop *time.Timer   // Connection dropper if `eth` sync progress isn't validated in time
+	snapWait chan struct{} // Notification channel for snap connections
+	lock     sync.RWMutex  // Mutex protecting the internal fields
 }
 
 // info gathers and returns some `eth` protocol metadata known about a peer.