[client] Cleanup dns and route states on startup (#2757)

client/internal/statemanager/path.go

@@ -0,0 +1,35 @@
+package statemanager
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/sirupsen/logrus"
+)
+
+// GetDefaultStatePath returns the path to the state file based on the operating system
+// It returns an empty string if the path cannot be determined. It also creates the directory if it does not exist.
+func GetDefaultStatePath() string {
+	var path string
+
+	switch runtime.GOOS {
+	case "windows":
+		path = filepath.Join(os.Getenv("PROGRAMDATA"), "Netbird", "state.json")
+	case "darwin", "linux":
+		path = "/var/lib/netbird/state.json"
+	case "freebsd", "openbsd", "netbsd", "dragonfly":
+		path = "/var/db/netbird/state.json"
+	// ios/android don't need state
+	default:
+		return ""
+	}
+
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		logrus.Errorf("Error creating directory %s: %v. Continuing without state support.", dir, err)
+		return ""
+	}
+
+	return path
+}