server: Remove UPnP support.

config.go

@@ -172,7 +172,7 @@ type config struct {
 	DisableDNSSeed bool     `long:"nodnsseed" description:"DEPRECATED: use --noseeders"`
 	ExternalIPs    []string `long:"externalip" description:"Add a public-facing IP to the list of local external IPs that dcrd will advertise to other peers"`
 	NoDiscoverIP   bool     `long:"nodiscoverip" description:"Disable automatic network address discovery of local external IPs"`
-	Upnp           bool     `long:"upnp" description:"Use UPnP to map our listening port outside of NAT"`
+	Upnp           bool     `long:"upnp" description:"REMOVED: This feature is no longer available and this flag will be removed in a future version"`
 
 	// Banning options.
 	DisableBanning bool          `long:"nobanning" description:"Disable banning of misbehaving peers"`

dcrd.go

@@ -71,6 +71,12 @@ func dcrdMain() error {
 		dcrdLog.Info("File logging disabled")
 	}
 
+	if cfg.Upnp {
+		dcrdLog.Warnf("The --upnp option is no longer supported.  Make sure " +
+			"to manually map the listening port on your router if you are " +
+			"behind NAT and wish to receive inbound connections")
+	}
+
 	// Block and transaction processing can cause bursty allocations.  This
 	// limits the garbage collector from excessively overallocating during
 	// bursts.  It does this by tweaking the soft memory limit.

doc.go

@@ -119,7 +119,6 @@ Application Options:
 	                             peers
 	    --nodiscoverip           Disable automatic network address discovery of
 	                             local external IPs
-	    --upnp                   Use UPnP to map our listening port outside of NAT
 	    --nobanning              Disable banning of misbehaving peers
 	    --banduration=           How long to ban misbehaving peers.  Valid time
 	                             units are {s, m, h}.  Minimum 1 second (default:

docs/default_ports.md

@@ -2,12 +2,9 @@ While dcrd is highly configurable when it comes to the network configuration,
 the following is intended to be a quick reference for the default ports used so
 port forwarding can be configured as required.
 
-dcrd provides a `--upnp` flag which can be used to automatically map the Decred
-peer-to-peer listening port if your router supports UPnP.  If your router does
-not support UPnP, or you don't wish to use it, please note that only the Decred
-peer-to-peer port should be forwarded unless you specifically want to allow RPC
-access to your dcrd from external sources such as in more advanced network
-configurations.
+Please note that only the Decred peer-to-peer port should be forwarded unless
+you specifically want to allow RPC access to your dcrd from external sources
+such as in more advanced network configurations.
 
 |Name|Port|
 |----|----|

server.go

@@ -588,7 +588,6 @@ type server struct {
 	peerState            peerState
 	relayInv             chan relayMsg
 	broadcast            chan broadcastMsg
-	nat                  *upnpNAT
 	db                   database.DB
 	timeSource           blockchain.MedianTimeSource
 	services             wire.ServiceFlag
@@ -2747,12 +2746,11 @@ func (s *server) handleAddPeer(sp *serverPeer) bool {
 	//  - There is an external IP explicitly set (--externalip)
 	//  - Listening has been disabled (--nolisten, listen disabled because of
 	//    --connect, etc)
-	//  - Universal Plug and Play is enabled (--upnp)
 	//  - The active network is simnet or regnet
 	if (cfg.Proxy != "" || cfg.OnionProxy != "") ||
 		cfg.NoDiscoverIP ||
 		len(cfg.ExternalIPs) > 0 ||
-		(cfg.DisableListen || len(cfg.Listeners) == 0) || cfg.Upnp ||
+		(cfg.DisableListen || len(cfg.Listeners) == 0) ||
 		s.chainParams.Name == simNetParams.Name ||
 		s.chainParams.Name == regNetParams.Name {
 
@@ -3586,14 +3584,6 @@ func (s *server) Run(ctx context.Context) {
 		wg.Done()
 	}()
 
-	if s.nat != nil {
-		wg.Add(1)
-		go func() {
-			s.upnpUpdateThread(ctx)
-			wg.Done()
-		}()
-	}
-
 	if !cfg.DisableRPC {
 		// Start the RPC server and rebroadcast handler which ensures
 		// transactions submitted to the RPC server are rebroadcast until being
@@ -3690,64 +3680,6 @@ func parseListeners(addrs []string) ([]net.Addr, error) {
 	return netAddrs, nil
 }
 
-func (s *server) upnpUpdateThread(ctx context.Context) {
-	// Go off immediately to prevent code duplication, thereafter we renew
-	// lease every 15 minutes.
-	timer := time.NewTimer(0 * time.Second)
-	lport, _ := strconv.ParseInt(s.chainParams.DefaultPort, 10, 16)
-
-	first := true
-out:
-	for {
-		select {
-		case <-timer.C:
-			// TODO: pick external port more cleverly
-			// TODO: know which ports we are listening to on an external net.
-			// TODO: if specific listen port doesn't work then ask for wildcard
-			// listen port?
-			// XXX this assumes timeout is in seconds.
-			listenPort, err := s.nat.AddPortMapping("tcp", int(lport), int(lport),
-				"dcrd listen port", 20*60)
-			if err != nil {
-				srvrLog.Warnf("can't add UPnP port mapping: %v", err)
-			}
-			if first && err == nil {
-				// TODO: look this up periodically to see if upnp domain changed
-				// and so did ip.
-				externalip, err := s.nat.GetExternalAddress()
-				if err != nil {
-					srvrLog.Warnf("UPnP can't get external address: %v", err)
-					continue out
-				}
-				localAddr := addrmgr.NewNetAddressFromIPPort(externalip,
-					uint16(listenPort), s.services)
-				err = s.addrManager.AddLocalAddress(localAddr, addrmgr.UpnpPrio)
-				if err != nil {
-					srvrLog.Warnf("Failed to add UPnP local address %s: %v",
-						localAddr, err)
-				} else {
-					srvrLog.Warnf("Successfully bound via UPnP to %s",
-						localAddr)
-					first = false
-				}
-			}
-			timer.Reset(time.Minute * 15)
-
-		case <-ctx.Done():
-			break out
-		}
-	}
-
-	timer.Stop()
-
-	err := s.nat.DeletePortMapping("tcp", int(lport), int(lport))
-	if err != nil {
-		srvrLog.Warnf("unable to remove UPnP port mapping: %v", err)
-	} else {
-		srvrLog.Debugf("successfully disestablished UPnP port mapping")
-	}
-}
-
 // standardScriptVerifyFlags returns the script flags that should be used when
 // executing transaction scripts to enforce additional checks which are required
 // for the script to be considered standard.  Note these flags are different
@@ -4104,10 +4036,9 @@ func newServer(ctx context.Context, profiler *profileServer,
 	services := defaultServices
 
 	var listeners []net.Listener
-	var nat *upnpNAT
 	if !cfg.DisableListen {
 		var err error
-		listeners, nat, err = initListeners(ctx, chainParams, amgr, listenAddrs,
+		listeners, err = initListeners(ctx, chainParams, amgr, listenAddrs,
 			services)
 		if err != nil {
 			return nil, err
@@ -4131,7 +4062,6 @@ func newServer(ctx context.Context, profiler *profileServer,
 		relayInv:             make(chan relayMsg, cfg.MaxPeers),
 		broadcast:            make(chan broadcastMsg, cfg.MaxPeers),
 		modifyRebroadcastInv: make(chan any),
-		nat:                  nat,
 		db:                   db,
 		timeSource:           blockchain.NewMedianTime(),
 		services:             services,
@@ -4616,13 +4546,12 @@ func newServer(ctx context.Context, profiler *profileServer,
 }
 
 // initListeners initializes the configured net listeners and adds any bound
-// addresses to the address manager. Returns the listeners and a NAT interface,
-// which is non-nil if UPnP is in use.
-func initListeners(ctx context.Context, params *chaincfg.Params, amgr *addrmgr.AddrManager, listenAddrs []string, services wire.ServiceFlag) ([]net.Listener, *upnpNAT, error) {
+// addresses to the address manager. Returns the listeners.
+func initListeners(ctx context.Context, params *chaincfg.Params, amgr *addrmgr.AddrManager, listenAddrs []string, services wire.ServiceFlag) ([]net.Listener, error) {
 	// Listen for TCP connections at the configured addresses
 	netAddrs, err := parseListeners(listenAddrs)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
 	var notifyAddrServer boundAddrEventServer
@@ -4642,13 +4571,12 @@ func initListeners(ctx context.Context, params *chaincfg.Params, amgr *addrmgr.A
 		notifyAddrServer.notifyP2PAddress(listener.Addr().String())
 	}
 
-	var nat *upnpNAT
 	if len(cfg.ExternalIPs) != 0 {
 		defaultPort, err := strconv.ParseUint(params.DefaultPort, 10, 16)
 		if err != nil {
 			srvrLog.Errorf("Can not parse default port %s for active chain: %v",
 				params.DefaultPort, err)
-			return nil, nil, err
+			return nil, err
 		}
 
 		for _, sip := range cfg.ExternalIPs {
@@ -4679,15 +4607,6 @@ func initListeners(ctx context.Context, params *chaincfg.Params, amgr *addrmgr.A
 			}
 		}
 	} else {
-		if cfg.Upnp {
-			var err error
-			nat, err = discover(ctx)
-			if err != nil {
-				srvrLog.Warnf("Can't discover upnp: %v", err)
-			}
-			// nil nat here is fine, just means no upnp on network.
-		}
-
 		// Add bound addresses to address manager to be advertised to peers.
 		for _, listener := range listeners {
 			addr := listener.Addr().String()
@@ -4698,7 +4617,7 @@ func initListeners(ctx context.Context, params *chaincfg.Params, amgr *addrmgr.A
 		}
 	}
 
-	return listeners, nat, nil
+	return listeners, nil
 }
 
 // addrStringToNetAddr takes an address in the form of 'host:port' and returns