From 162ebffe48e9239778353d2acedeb193b82062cc Mon Sep 17 00:00:00 2001
From: Daniel <dhaavi@users.noreply.github.com>
Date: Fri, 9 Feb 2024 14:28:06 +0100
Subject: [PATCH] Skip self-check if device is offline

---
 compat/module.go    | 4 ++++
 compat/selfcheck.go | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/compat/module.go b/compat/module.go
index ea5fcd69..c159d02f 100644
--- a/compat/module.go
+++ b/compat/module.go
@@ -2,6 +2,7 @@ package compat
 
 import (
 	"context"
+	"errors"
 	"time"
 
 	"github.com/tevino/abool"
@@ -92,6 +93,9 @@ func selfcheckTaskFunc(ctx context.Context, task *modules.Task) error {
 	case err == nil:
 		// Successful.
 		tracer.Debugf("compat: self-check successful")
+	case errors.Is(err, errSelfcheckSkipped):
+		// Skipped.
+		tracer.Debugf("compat: %s", err)
 	case issue == nil:
 		// Internal error.
 		tracer.Warningf("compat: %s", err)
diff --git a/compat/selfcheck.go b/compat/selfcheck.go
index fd4a22bc..e26c1ed5 100644
--- a/compat/selfcheck.go
+++ b/compat/selfcheck.go
@@ -3,6 +3,7 @@ package compat
 import (
 	"context"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"net"
 	"strings"
@@ -11,6 +12,7 @@ import (
 
 	"github.com/safing/portbase/log"
 	"github.com/safing/portbase/rng"
+	"github.com/safing/portmaster/netenv"
 	"github.com/safing/portmaster/network/packet"
 	"github.com/safing/portmaster/resolver"
 )
@@ -36,12 +38,19 @@ var (
 	dnsCheckWaitDuration        = 45 * time.Second
 	dnsCheckAnswerLock          sync.Mutex
 	dnsCheckAnswer              net.IP
+
+	errSelfcheckSkipped = errors.New("self-check skipped")
 )
 
 func selfcheck(ctx context.Context) (issue *systemIssue, err error) {
 	selfcheckLock.Lock()
 	defer selfcheckLock.Unlock()
 
+	// Step 0: Check if self-check makes sense.
+	if !netenv.Online() {
+		return nil, fmt.Errorf("%w: device is offline or in limited network", errSelfcheckSkipped)
+	}
+
 	// Step 1: Check if the system integration sees a packet.
 
 	// Empty recv channel.