[client] Add PCP support

client/internal/portforward/env.go

@@ -8,18 +8,27 @@ import (
 )
 
 const (
-	envDisableNATMapper = "NB_DISABLE_NAT_MAPPER"
+	envDisableNATMapper      = "NB_DISABLE_NAT_MAPPER"
+	envDisablePCPHealthCheck = "NB_DISABLE_PCP_HEALTH_CHECK"
 )
 
 func isDisabledByEnv() bool {
-	val := os.Getenv(envDisableNATMapper)
+	return parseBoolEnv(envDisableNATMapper)
+}
+
+func isHealthCheckDisabled() bool {
+	return parseBoolEnv(envDisablePCPHealthCheck)
+}
+
+func parseBoolEnv(key string) bool {
+	val := os.Getenv(key)
 	if val == "" {
 		return false
 	}
 
 	disabled, err := strconv.ParseBool(val)
 	if err != nil {
-		log.Warnf("failed to parse %s: %v", envDisableNATMapper, err)
+		log.Warnf("failed to parse %s: %v", key, err)
 		return false
 	}
 	return disabled

client/internal/portforward/manager.go

@@ -12,12 +12,15 @@ import (
 
 	"github.com/libp2p/go-nat"
 	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/internal/portforward/pcp"
 )
 
 const (
-	defaultMappingTTL  = 2 * time.Hour
-	discoveryTimeout   = 10 * time.Second
-	mappingDescription = "NetBird"
+	defaultMappingTTL   = 2 * time.Hour
+	healthCheckInterval = 1 * time.Minute
+	discoveryTimeout    = 10 * time.Second
+	mappingDescription  = "NetBird"
 )
 
 // upnpErrPermanentLeaseOnly matches UPnP error 725 in SOAP fault XML,
@@ -154,7 +157,7 @@ func (m *Manager) setup(ctx context.Context) (nat.NAT, *Mapping, error) {
 	discoverCtx, discoverCancel := context.WithTimeout(ctx, discoveryTimeout)
 	defer discoverCancel()
 
-	gateway, err := nat.DiscoverGateway(discoverCtx)
+	gateway, err := discoverGateway(discoverCtx)
 	if err != nil {
 		return nil, nil, fmt.Errorf("discover gateway: %w", err)
 	}
@@ -189,7 +192,6 @@ func (m *Manager) createMapping(ctx context.Context, gateway nat.NAT) (*Mapping,
 	externalIP, err := gateway.GetExternalAddress()
 	if err != nil {
 		log.Debugf("failed to get external address: %v", err)
-		// todo return with err?
 	}
 
 	mapping := &Mapping{
@@ -208,25 +210,85 @@ func (m *Manager) createMapping(ctx context.Context, gateway nat.NAT) (*Mapping,
 
 func (m *Manager) renewLoop(ctx context.Context, gateway nat.NAT, ttl time.Duration) {
 	if ttl == 0 {
-		// Permanent mappings don't expire, just wait for cancellation.
-		<-ctx.Done()
+		// Permanent mappings don't expire, just wait for cancellation
+		// but still run health checks for PCP gateways.
+		m.permanentLeaseLoop(ctx, gateway)
 		return
 	}
 
-	ticker := time.NewTicker(ttl / 2)
-	defer ticker.Stop()
+	renewTicker := time.NewTicker(ttl / 2)
+	healthTicker := time.NewTicker(healthCheckInterval)
+	defer renewTicker.Stop()
+	defer healthTicker.Stop()
 
 	for {
 		select {
 		case <-ctx.Done():
 			return
-		case <-ticker.C:
+		case <-renewTicker.C:
 			if err := m.renewMapping(ctx, gateway); err != nil {
 				log.Warnf("failed to renew port mapping: %v", err)
 				continue
 			}
+		case <-healthTicker.C:
+			if m.checkHealthAndRecreate(ctx, gateway) {
+				renewTicker.Reset(ttl / 2)
+			}
+		}
+	}
+}
+
+func (m *Manager) permanentLeaseLoop(ctx context.Context, gateway nat.NAT) {
+	healthTicker := time.NewTicker(healthCheckInterval)
+	defer healthTicker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-healthTicker.C:
+			m.checkHealthAndRecreate(ctx, gateway)
+		}
+	}
+}
+
+func (m *Manager) checkHealthAndRecreate(ctx context.Context, gateway nat.NAT) bool {
+	if isHealthCheckDisabled() {
+		return false
+	}
+
+	m.mappingLock.Lock()
+	hasMapping := m.mapping != nil
+	m.mappingLock.Unlock()
+
+	if !hasMapping {
+		return false
+	}
+
+	pcpNAT, ok := gateway.(*pcp.NAT)
+	if !ok {
+		return false
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+
+	epoch, serverRestarted, err := pcpNAT.CheckServerHealth(ctx)
+	if err != nil {
+		log.Debugf("PCP health check failed: %v", err)
+		return false
+	}
+
+	if serverRestarted {
+		log.Warnf("PCP server restart detected (epoch=%d), recreating port mapping", epoch)
+		if err := m.renewMapping(ctx, gateway); err != nil {
+			log.Errorf("failed to recreate port mapping after server restart: %v", err)
+			return false
 		}
+		return true
 	}
+
+	return false
 }
 
 func (m *Manager) renewMapping(ctx context.Context, gateway nat.NAT) error {