package swarm import ( "context" "fmt" conn "github.com/libp2p/go-libp2p-conn" iconn "github.com/libp2p/go-libp2p-interface-conn" lgbl "github.com/libp2p/go-libp2p-loggables" mconn "github.com/libp2p/go-libp2p-metrics/conn" inet "github.com/libp2p/go-libp2p-net" transport "github.com/libp2p/go-libp2p-transport" ps "github.com/libp2p/go-peerstream" ma "github.com/multiformats/go-multiaddr" ) func (s *Swarm) AddListenAddr(a ma.Multiaddr) error { tpt := s.transportForAddr(a) if tpt == nil { return fmt.Errorf("no transport for address: %s", a) } d, err := tpt.Dialer(a, transport.TimeoutOpt(DialTimeout), transport.ReusePorts) if err != nil { return err } s.dialer.AddDialer(d) list, err := tpt.Listen(a) if err != nil { return err } err = s.addListener(list) if err != nil { return err } return nil } // Open listeners and reuse-dialers for the given addresses func (s *Swarm) setupInterfaces(addrs []ma.Multiaddr) error { errs := make([]error, len(addrs)) var succeeded int for i, a := range addrs { if err := s.AddListenAddr(a); err != nil { errs[i] = err } else { succeeded++ } } for i, e := range errs { if e != nil { log.Warningf("listen on %s failed: %s", addrs[i], errs[i]) } } if succeeded == 0 && len(addrs) > 0 { return fmt.Errorf("failed to listen on any addresses: %s", errs) } return nil } func (s *Swarm) transportForAddr(a ma.Multiaddr) transport.Transport { for _, t := range s.transports { if t.Matches(a) { return t } } return nil } func (s *Swarm) addListener(tptlist transport.Listener) error { sk := s.peers.PrivKey(s.local) if sk == nil { // may be fine for sk to be nil, just log a warning. log.Warning("Listener not given PrivateKey, so WILL NOT SECURE conns.") } list, err := conn.WrapTransportListenerWithProtector(s.Context(), tptlist, s.local, sk, s.protec) if err != nil { return err } list.SetAddrFilters(s.Filters) if cw, ok := list.(conn.ListenerConnWrapper); ok && s.bwc != nil { cw.SetConnWrapper(func(c transport.Conn) transport.Conn { return mconn.WrapConn(s.bwc, c) }) } return s.addConnListener(list) } func (s *Swarm) addConnListener(list iconn.Listener) error { // AddListener to the peerstream Listener. this will begin accepting connections // and streams! sl, err := s.swarm.AddListener(list) if err != nil { return err } log.Debugf("Swarm Listeners at %s", s.ListenAddresses()) maddr := list.Multiaddr() // signal to our notifiees on successful conn. s.notifyAll(func(n inet.Notifiee) { n.Listen((*Network)(s), maddr) }) // go consume peerstream's listen accept errors. note, these ARE errors. // they may be killing the listener, and if we get _any_ we should be // fixing this in our conn.Listener (to ignore them or handle them // differently.) go func(ctx context.Context, sl *ps.Listener) { // signal to our notifiees closing defer s.notifyAll(func(n inet.Notifiee) { n.ListenClose((*Network)(s), maddr) }) for { select { case err, more := <-sl.AcceptErrors(): if !more { return } log.Warningf("swarm listener accept error: %s", err) case <-ctx.Done(): return } } }(s.Context(), sl) return nil } // connHandler is called by the StreamSwarm whenever a new connection is added // here we configure it slightly. Note that this is sequential, so if anything // will take a while do it in a goroutine. // See https://godoc.org/github.com/libp2p/go-peerstream for more information func (s *Swarm) connHandler(c *ps.Conn) *Conn { ctx := context.Background() // this context is for running the handshake, which -- when receiveing connections // -- we have no bound on beyond what the transport protocol bounds it at. // note that setup + the handshake are bounded by underlying io. // (i.e. if TCP or UDP disconnects (or the swarm closes), we're done. // Q: why not have a shorter handshake? think about an HTTP server on really slow conns. // as long as the conn is live (TCP says its online), it tries its best. we follow suit.) sc, err := s.newConnSetup(ctx, c) if err != nil { log.Debug(err) log.Event(ctx, "newConnHandlerDisconnect", lgbl.NetConn(c.NetConn()), lgbl.Error(err)) c.Close() // boom. close it. return nil } // if a peer dials us, remove from dial backoff. s.backf.Clear(sc.RemotePeer()) return sc }