Prefer Linux network status detection using the xdg-desktop-portal interface that works without special privileges in sandbox contexts

src/calibre/utils/network.py

@@ -7,30 +7,71 @@ from calibre.constants import iswindows, islinux, isbsd
 from calibre.utils.config_base import tweaks
 
 
-class LinuxNetworkStatus(object):
+class LinuxNetworkStatus:
+
+    # Map of NetworkManager connectivity values to their XDP/GLib equivalents
+    NM_XDP_CONNECTIVITY_MAP = {
+        0: 4,  # NM_CONNECTIVITY_UNKNOWN → Full network
+        1: 1,  # NM_CONNECTIVITY_NONE → Local only
+        2: 3,  # NM_CONNECTIVITY_PORTAL → Captive portal
+        3: 2,  # NM_CONNECTIVITY_LIMITED → Limited connectivity
+        4: 4,  # NM_CONNECTIVITY_FULL → Full network
+    }
 
     def __init__(self):
+        # Prefer desktop portal interface here since it can theoretically
+        # work with network management solutions other than NetworkManager
+        # and is controlled by the current desktop session
+        #
+        # There is no difference in terms of “features” provided between
+        # the two APIs from our point of view.
+        self.get_connectivity = self.connect_to_xdp()
+        if self.get_connectivity != None:
+            return
+
+        self.get_connectivity = self.connect_to_nm()
+
+    @staticmethod
+    def connect_to_xdp():
+        try:
+            import dbus
+            bus = dbus.SessionBus()
+            proxy = bus.get_object("org.freedesktop.portal.Desktop",
+                        "/org/freedesktop/portal/desktop")
+            return proxy.get_dbus_method("GetConnectivity",
+                        "org.freedesktop.portal.NetworkMonitor")
+        except:
+            return None
+
+    @classmethod
+    def connect_to_nm(cls):
         try:
             import dbus
             bus = dbus.SystemBus()
             proxy = bus.get_object("org.freedesktop.NetworkManager",
                         "/org/freedesktop/NetworkManager")
-            self.manager = dbus.Interface(proxy, "org.freedesktop.DBus.Properties")
+            prop_getter = proxy.get_dbus_method("Get",
+                        "org.freedesktop.DBus.Properties")
+            return (lambda: cls.NM_XDP_CONNECTIVITY_MAP.get(
+                 prop_getter("org.freedesktop.NetworkManager", "Connectivity"), 4
+            ))
         except:
-            self.manager = None
+            return None
 
     def __call__(self):
-        if self.manager is None:
+        if self.get_connectivity is None:
             return True
         try:
-            connections = self.manager.Get("org.freedesktop.NetworkManager",
-                        "ActiveConnections")
-            return len(connections) > 0
+            # Meanings of returned XDP/GLib connectivity values:
+            #   * 1: Local only. The host is not configured with a route to the internet.
+            #   * 2: Limited connectivity. The host is connected to a network, but can't reach the full internet.
+            #   * 3: Captive portal. The host is behind a captive portal and cannot reach the full internet.
+            #   * 4: Full network. The host connected to a network, and can reach the full internet.
+            return self.get_connectivity() == 4
         except:
             return True
 
-
-class WindowsNetworkStatus(object):
+class WindowsNetworkStatus:
 
     def __init__(self):
         from calibre_extensions import winutil
@@ -42,7 +83,7 @@ class WindowsNetworkStatus(object):
         return self.winutil.internet_connected()
 
 
-class DummyNetworkStatus(object):
+class DummyNetworkStatus:
 
     def __call__(self):
         return True