eth/connmanager: move Connection Manager to package eth

Better positioned in package eth to access relevant data about
connection quality.

eth/backend.go

@@ -76,6 +76,7 @@ type Ethereum struct {
 
 	handler *handler
 	discmix *enode.FairMix
+	connman *connManager
 
 	// DB interfaces
 	chainDb ethdb.Database // Block chain database
@@ -289,6 +290,10 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 		return nil, err
 	}
 
+	eth.connman = newConnManager(&connmanConfig{
+		maxDialPeers: eth.p2pServer.MaxDialedConns(),
+	})
+
 	eth.miner = miner.New(eth, config.Miner, eth.engine)
 	eth.miner.SetExtra(makeExtraData(config.Miner.ExtraData))
 	eth.miner.SetPrioAddresses(config.TxPool.Locals)
@@ -399,6 +404,9 @@ func (s *Ethereum) Start() error {
 	// Start the networking layer
 	s.handler.Start(s.p2pServer.MaxPeers)
 
+	// Start the connection manager
+	s.connman.Start(s.p2pServer)
+
 	// start log indexer
 	s.filterMaps.Start()
 	go s.updateFilterMapsHeads()
@@ -500,6 +508,7 @@ func (s *Ethereum) setupDiscovery() error {
 func (s *Ethereum) Stop() error {
 	// Stop all the peer-related stuff first.
 	s.discmix.Close()
+	s.connman.Stop()
 	s.handler.Stop()
 
 	// Then stop everything else.

eth/connmanager.go

@@ -14,17 +14,20 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
-package p2p
+package eth
 
 import (
 	crand "crypto/rand"
 	"encoding/binary"
 	mrand "math/rand"
+	"sync"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/mclock"
+	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/p2p"
 )
 
 const (
@@ -43,16 +46,20 @@ const (
 //     peerDropInterval to make space for new peers
 type connManager struct {
 	connmanConfig
+	srv       *p2p.Server
 	peersFunc getPeersFunc
 
 	// the peerDrop timer introduces churn if we are close to limit capacity
 	peerDropTimer *mclock.Alarm
-	addPeerCh     chan *conn
+	peerEventCh   chan *p2p.PeerEvent
-	remPeerCh     chan *conn
+	sub           event.Subscription
+
+	wg         sync.WaitGroup
+	shutdownCh chan struct{}
 }
 
 // callback type to get the list of connected peers.
-type getPeersFunc func() []*Peer
+type getPeersFunc func() []*p2p.Peer
 
 type connmanConfig struct {
 	maxDialPeers int // maximum number of dialed peers
@@ -77,33 +84,32 @@ func (cfg connmanConfig) withDefaults() connmanConfig {
 	return cfg
 }
 
-func newConnManager(config connmanConfig, peersFunc getPeersFunc) *connManager {
+func newConnManager(config *connmanConfig) *connManager {
 	cfg := config.withDefaults()
 	cm := &connManager{
 		connmanConfig: cfg,
 		peerDropTimer: mclock.NewAlarm(cfg.clock),
-		peersFunc:     peersFunc,
+		peerEventCh:   make(chan *p2p.PeerEvent),
-		addPeerCh:     make(chan *conn),
+		shutdownCh:    make(chan struct{}),
-		remPeerCh:     make(chan *conn),
 	}
 	cm.log.Info("New Connection Manager", "maxDialPeers", cm.maxDialPeers, "threshold", peerDropThreshold, "interval", peerDropInterval)
-	go cm.loop()
 	return cm
 }
 
+func (cm *connManager) Start(srv *p2p.Server) {
+	cm.wg.Add(1)
+	cm.srv = srv
+	cm.peersFunc = srv.Peers
+	cm.sub = srv.SubscribeEvents(cm.peerEventCh)
+	go cm.loop()
+}
+
 // stop the connection manager.
-func (cm *connManager) stop() {
+func (cm *connManager) Stop() {
+	cm.sub.Unsubscribe()
 	cm.peerDropTimer.Stop()
-}
+	close(cm.shutdownCh)
-
+	cm.wg.Wait()
-// peerAdded notifies about peerset change.
-func (cm *connManager) peerAdded(c *conn) {
-	cm.addPeerCh <- c
-}
-
-// peerRemoved notifies about peerset change.
-func (cm *connManager) peerRemoved(c *conn) {
-	cm.remPeerCh <- c
 }
 
 // filter is a helper function to filter the peerset.
@@ -118,13 +124,13 @@ func filter[T any](s []T, test func(T) bool) (filtered []T) {
 
 // numDialPeers returns the current number of peers dialed (not inbound).
 func (cm *connManager) numDialPeers() int {
-	selectDialed := func(p *Peer) bool { return !p.rw.is(inboundConn) }
+	selectDialed := func(p *p2p.Peer) bool { return !p.Inbound() }
 	dialed := filter(cm.peersFunc(), selectDialed)
 	return len(dialed)
 }
 
 func (cm *connManager) numPeers() (int, int, int) {
-	selectDialed := func(p *Peer) bool { return !p.rw.is(inboundConn) }
+	selectDialed := func(p *p2p.Peer) bool { return !p.Inbound() }
 	peers := cm.peersFunc()
 	dialed := filter(peers, selectDialed)
 	return len(peers), len(dialed), len(peers) - len(dialed)
@@ -136,15 +142,15 @@ func (cm *connManager) dropRandomPeer() bool {
 
 	// Only drop from dyndialed peers. Avoid dropping trusted peers.
 	// Give some time to peers before considering them for a drop.
-	selectDroppable := func(p *Peer) bool {
+	selectDroppable := func(p *p2p.Peer) bool {
-		return p.rw.is(dynDialedConn) && !p.rw.is(trustedConn) &&
+		return p.DynDialed() && !p.Trusted() &&
-			mclock.Now()-p.created >= mclock.AbsTime(doNotDropBefore)
+			p.Lifetime() >= mclock.AbsTime(doNotDropBefore)
 	}
 	droppable := filter(peers, selectDroppable)
 	if len(droppable) > 0 {
 		p := droppable[cm.rand.Intn(len(droppable))]
-		cm.log.Trace("dropping random peer", "id", p.ID(), "duration", common.PrettyDuration(mclock.Now()-p.created), "peercountbefore", len(peers))
+		cm.log.Info("dropping random peer", "id", p.ID(), "duration", common.PrettyDuration(p.Lifetime()), "peercountbefore", len(peers))
-		p.Disconnect(DiscDropped)
+		p.Disconnect(p2p.DiscTooManyPeers)
 		return true
 	}
 	return false
@@ -152,31 +158,34 @@ func (cm *connManager) dropRandomPeer() bool {
 
 // loop is the main loop of the connection manager.
 func (cm *connManager) loop() {
+	defer cm.wg.Done()
 
 	for {
-
 		select {
+		case ev := <-cm.peerEventCh:
+			switch ev.Type {
+			case p2p.PeerEventTypeAdd:
+				// check and start timer for peer drop
+				// If a drop was already scheduled, Schedule does nothing.
+				numpeers, out, in := cm.numPeers()
+				cm.log.Info("addPeerCh", "peers", numpeers, "out", out, "in", in, "maxout", cm.maxDialPeers)
+				if cm.maxDialPeers-cm.numDialPeers() <= peerDropThreshold {
+					cm.peerDropTimer.Schedule(cm.clock.Now().Add(peerDropInterval))
+				}
 
-		case <-cm.addPeerCh:
+			case p2p.PeerEventTypeDrop:
-			// check and start timer for peer drop
+				// check and stop timer for peer drop
-			// If a drop was already scheduled, Schedule does nothing.
+				numpeers, out, in := cm.numPeers()
-			numpeers, out, in := cm.numPeers()
+				cm.log.Info("remPeerCh", "peers", numpeers, "out", out, "in", in, "maxout", cm.maxDialPeers)
-			cm.log.Trace("addPeerCh", "peers", numpeers, "out", out, "in", in, "maxout", cm.maxDialPeers)
+				if cm.maxDialPeers-cm.numDialPeers() > peerDropThreshold {
-			if cm.maxDialPeers-cm.numDialPeers() <= peerDropThreshold {
+					cm.peerDropTimer.Stop()
-				cm.peerDropTimer.Schedule(cm.clock.Now().Add(peerDropInterval))
+				}
-			}
-
-		case <-cm.remPeerCh:
-			// check and stop timer for peer drop
-			numpeers, out, in := cm.numPeers()
-			cm.log.Trace("remPeerCh", "peers", numpeers, "out", out, "in", in, "maxout", cm.maxDialPeers)
-			if cm.maxDialPeers-cm.numDialPeers() > peerDropThreshold {
-				cm.peerDropTimer.Stop()
 			}
 
 		case <-cm.peerDropTimer.C():
 			cm.dropRandomPeer()
+		case <-cm.shutdownCh:
+			return
 		}
 	}
-	cm.log.Warn("Exiting connmanager loop")
 }

p2p/peer_error.go

@@ -69,7 +69,6 @@ const (
 	DiscUnexpectedIdentity
 	DiscSelf
 	DiscReadTimeout
-	DiscDropped
 	DiscSubprotocolError = DiscReason(0x10)
 
 	DiscInvalid = 0xff
@@ -88,7 +87,6 @@ var discReasonToString = [...]string{
 	DiscUnexpectedIdentity:  "unexpected identity",
 	DiscSelf:                "connected to self",
 	DiscReadTimeout:         "read timeout",
-	DiscDropped:             "dropped to make space for others",
 	DiscSubprotocolError:    "subprotocol error",
 	DiscInvalid:             "invalid disconnect reason",
 }

p2p/server.go

@@ -97,7 +97,6 @@ type Server struct {
 	discv5    *discover.UDPv5
 	discmix   *enode.FairMix
 	dialsched *dialScheduler
-	connman   *connManager
 
 	// This is read by the NAT port mapping loop.
 	portMappingRegister chan *portMapping
@@ -412,8 +411,6 @@ func (srv *Server) Start() (err error) {
 	}
 	srv.setupDialScheduler()
 
-	srv.setupConnManager()
-
 	srv.loopWG.Add(1)
 	go srv.run()
 	return nil
@@ -530,11 +527,6 @@ func (srv *Server) setupDialScheduler() {
 	}
 }
 
-func (srv *Server) setupConnManager() {
-	config := connmanConfig{maxDialPeers: srv.maxDialedConns()}
-	srv.connman = newConnManager(config, srv.Peers)
-}
-
 func (srv *Server) MaxInboundConns() int {
 	return srv.MaxPeers - srv.MaxDialedConns()
 }
@@ -689,7 +681,6 @@ running:
 				peers[c.node.ID()] = p
 				srv.log.Debug("Adding p2p peer", "peercount", len(peers), "id", p.ID(), "conn", c.flags, "addr", p.RemoteAddr(), "name", p.Name())
 				srv.dialsched.peerAdded(c)
-				srv.connman.peerAdded(c)
 				if p.Inbound() {
 					inboundCount++
 					serveSuccessMeter.Mark(1)
@@ -708,7 +699,6 @@ running:
 			delete(peers, pd.ID())
 			srv.log.Debug("Removing p2p peer", "peercount", len(peers), "id", pd.ID(), "duration", d, "req", pd.requested, "err", pd.err)
 			srv.dialsched.peerRemoved(pd.rw)
-			srv.connman.peerRemoved(pd.rw)
 			if pd.Inbound() {
 				inboundCount--
 				activeInboundPeerGauge.Dec(1)