Retry NAT punching without duration on mapping failure

Some hardware doesn't support UPnP with durations.

p2p/nat/nat.go

@@ -155,12 +155,13 @@ type Mapping interface {
 type mapping struct {
 	sync.Mutex // guards all fields
 
-	nat     *NAT
-	proto   string
-	intport int
-	extport int
-	intaddr ma.Multiaddr
-	proc    goprocess.Process
+	nat       *NAT
+	proto     string
+	intport   int
+	extport   int
+	permanent bool
+	intaddr   ma.Multiaddr
+	proc      goprocess.Process
 
 	cached    ma.Multiaddr
 	cacheTime time.Time
@@ -197,6 +198,18 @@ func (m *mapping) setExternalPort(p int) {
 	m.extport = p
 }
 
+func (m *mapping) setPermanent(p bool) {
+	m.Lock()
+	defer m.Unlock()
+	m.permanent = p
+}
+
+func (m *mapping) isPermanent() bool {
+	m.Lock()
+	defer m.Unlock()
+	return m.permanent
+}
+
 func (m *mapping) InternalAddr() ma.Multiaddr {
 	m.Lock()
 	defer m.Unlock()
@@ -333,13 +346,26 @@ func (nat *NAT) NewMapping(maddr ma.Multiaddr) (Mapping, error) {
 
 func (nat *NAT) establishMapping(m *mapping) {
 	oldport := m.ExternalPort()
+	if oldport != 0 && m.isPermanent() {
+		// mapping was already established and it is permanent
+		return
+	}
+
 	log.Debugf("Attempting port map: %s/%d", m.Protocol(), m.InternalPort())
-	newport, err := nat.nat.AddPortMapping(m.Protocol(), m.InternalPort(), "http", MappingDuration)
+	permanent := false
+
+	newport, err := nat.nat.AddPortMapping(m.Protocol(), m.InternalPort(), "libp2p", MappingDuration)
+
+	if err != nil {
+		// Some hardware does not support mappings with timeout, so try that
+		newport, err = nat.nat.AddPortMapping(m.Protocol(), m.InternalPort(), "libp2p", 0)
+		permanent = (err == nil)
+	}
 
 	failure := func() {
 		m.setExternalPort(0) // clear mapping
 		// TODO: log.Event
-		log.Debugf("failed to establish port mapping: %s", err)
+		log.Warningf("failed to establish port mapping: %s", err)
 		nat.Notifier.notifyAll(func(n Notifiee) {
 			n.MappingFailed(nat, m, oldport, err)
 		})
@@ -353,6 +379,7 @@ func (nat *NAT) establishMapping(m *mapping) {
 		return
 	}
 
+	m.setPermanent(permanent)
 	m.setExternalPort(newport)
 	ext, err := m.ExternalAddr()
 	if err != nil {