fix: remove old addresses in identify immediately

Previously, we'd keep addresses discovered through the DHT for up to 2
minutes (temporary TTL) and previously seen addresses (recently connected) for
up to 10 minutes (the TTL).

1. Make sure to downgrade both connected and recently connected addresses to the
"temporary" ttl before adding new addresses.
2. Finally, downgrade addresses with the temporary TTL to 0.

This could be more efficient with a better peerstore abstraction, but this is
better than nothing.

p2p/protocol/identify/id.go

@@ -56,9 +56,6 @@ func init() {
 	}
 }
 
-// transientTTL is a short ttl for invalidated previously connected addrs
-const transientTTL = 10 * time.Second
-
 type addPeerHandlerReq struct {
 	rp   peer.ID
 	resp chan *peerHandler
@@ -546,9 +543,13 @@ func (ids *IDService) consumeMessage(mes *pb.Identify, c network.Conn) {
 		ttl = peerstore.ConnectedAddrTTL
 	}
 
-	// invalidate previous addrs -- we use a transient ttl instead of 0 to ensure there
-	// is no period of having no good addrs whatsoever
-	ids.Host.Peerstore().UpdateAddrs(p, peerstore.ConnectedAddrTTL, transientTTL)
+	// Downgrade connected and recently connected addrs to a temporary TTL.
+	for _, ttl := range []time.Duration{
+		peerstore.RecentlyConnectedAddrTTL,
+		peerstore.ConnectedAddrTTL,
+	} {
+		ids.Host.Peerstore().UpdateAddrs(p, ttl, peerstore.TempAddrTTL)
+	}
 
 	// add signed addrs if we have them and the peerstore supports them
 	cab, ok := peerstore.GetCertifiedAddrBook(ids.Host.Peerstore())
@@ -560,6 +561,9 @@ func (ids *IDService) consumeMessage(mes *pb.Identify, c network.Conn) {
 	} else {
 		ids.Host.Peerstore().AddAddrs(p, lmaddrs, ttl)
 	}
+
+	// Finally, expire all temporary addrs.
+	ids.Host.Peerstore().UpdateAddrs(p, peerstore.TempAddrTTL, 0)
 	ids.addrMu.Unlock()
 
 	log.Debugf("%s received listen addrs for %s: %s", c.LocalPeer(), c.RemotePeer(), lmaddrs)