From ed2338fdb94478b462f5e833883e242e9023d9c8 Mon Sep 17 00:00:00 2001
From: Vladimir Stoilov <vladimir@safing.io>
Date: Mon, 2 Dec 2024 15:15:46 +0200
Subject: [PATCH] [service] Fix error on unitilized dns monitor

---
 .../interception/dnsmonitor/etwlink_windows.go       |  7 +++++++
 .../interception/dnsmonitor/eventlistener_windows.go |  3 +++
 service/integration/integration_windows.go           | 12 ++++++++++++
 service/network/connection.go                        |  6 +++++-
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/service/firewall/interception/dnsmonitor/etwlink_windows.go b/service/firewall/interception/dnsmonitor/etwlink_windows.go
index e0d48bdcf..cb9d8675f 100644
--- a/service/firewall/interception/dnsmonitor/etwlink_windows.go
+++ b/service/firewall/interception/dnsmonitor/etwlink_windows.go
@@ -68,6 +68,10 @@ func (l *ETWSession) IsRunning() bool {
 
 // FlushTrace flushes the trace buffer.
 func (l *ETWSession) FlushTrace() error {
+	if l.i == nil {
+		return fmt.Errorf("session not initialized")
+	}
+
 	l.shutdownMutex.Lock()
 	defer l.shutdownMutex.Unlock()
 
@@ -86,6 +90,9 @@ func (l *ETWSession) StopTrace() error {
 
 // DestroySession closes the session and frees the allocated memory. Listener cannot be used after this function is called.
 func (l *ETWSession) DestroySession() error {
+	if l.i == nil {
+		return fmt.Errorf("session not initialized")
+	}
 	l.shutdownMutex.Lock()
 	defer l.shutdownMutex.Unlock()
 
diff --git a/service/firewall/interception/dnsmonitor/eventlistener_windows.go b/service/firewall/interception/dnsmonitor/eventlistener_windows.go
index 283101365..a46e8cc6b 100644
--- a/service/firewall/interception/dnsmonitor/eventlistener_windows.go
+++ b/service/firewall/interception/dnsmonitor/eventlistener_windows.go
@@ -52,6 +52,9 @@ func initializeSessions(module *DNSMonitor, listener *Listener) error {
 }
 
 func (l *Listener) flush() error {
+	if l.etw == nil {
+		return fmt.Errorf("etw not initialized")
+	}
 	return l.etw.FlushTrace()
 }
 
diff --git a/service/integration/integration_windows.go b/service/integration/integration_windows.go
index 0ca123fc0..b297b3638 100644
--- a/service/integration/integration_windows.go
+++ b/service/integration/integration_windows.go
@@ -5,6 +5,7 @@ package integration
 
 import (
 	"fmt"
+	"sync"
 
 	"github.com/safing/portmaster/base/log"
 	"github.com/safing/portmaster/service/mgr"
@@ -24,14 +25,25 @@ func (i *OSIntegration) Initialize() error {
 	if err != nil {
 		log.Errorf("integration: failed to load dll: %s", err)
 
+		callbackLock := sync.Mutex{}
 		// listen for event from the updater and try to load again if any.
 		i.instance.Updates().EventResourcesUpdated.AddCallback("core-dll-loader", func(wc *mgr.WorkerCtx, s struct{}) (cancel bool, err error) {
+			// Make sure no multiple callas are executed at the same time.
+			callbackLock.Lock()
+			defer callbackLock.Unlock()
+
+			// Try to load again.
 			err = i.loadDLL()
 			if err != nil {
 				log.Errorf("integration: failed to load dll: %s", err)
+			} else {
+				log.Info("integration: initialize successful after updater event")
 			}
 			return false, nil
 		})
+
+	} else {
+		log.Info("integration: initialize successful")
 	}
 	return nil
 }
diff --git a/service/network/connection.go b/service/network/connection.go
index b3dd70fcc..1c1bbf198 100644
--- a/service/network/connection.go
+++ b/service/network/connection.go
@@ -550,7 +550,11 @@ func (conn *Connection) GatherConnectionInfo(pkt packet.Packet) (err error) {
 			if module.instance.Resolver().IsDisabled() && conn.shouldWaitForDomain() {
 				// Flush the dns listener buffer and try again.
 				for i := range 4 {
-					_ = module.instance.DNSMonitor().Flush()
+					err = module.instance.DNSMonitor().Flush()
+					if err != nil {
+						// Error flushing, dont try again.
+						break
+					}
 					ipinfo, err = resolver.GetIPInfo(resolver.IPInfoProfileScopeGlobal, pkt.Info().RemoteIP().String())
 					if err == nil {
 						log.Tracer(pkt.Ctx()).Debugf("network: found domain from dnsmonitor after %d tries", i+1)