wifi: require wifi.scan permission to start/stop P2P scan

Users should not be allowed to start or stop a wifi-p2p scan unless
they have some kind of permission. Since we already have the
"org.freedesktop.NetworkManager.wifi.scan" permission for wifi scans,
check that.

Fixes: dd0c59c468 ('core/devices: Add DBus methods to start/stop a P2P find')

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1795

NEWS

@@ -14,6 +14,9 @@ Overview of changes since NetworkManager-1.44
   link local addresses on default wired connection.
 * Honor udev property ID_NET_MANAGED_BY to only manage an interface
   when set to "org.freedesktop.NetworkManager".
+* D-Bus methods StartFind() and StopFind() on interface
+  "org.freedesktop.NetworkManager.Device.WifiP2P" now require the
+  "org.freedesktop.NetworkManager.wifi.scan" Polkit permission.
 * Drop build support with Python2. Python3 is now required.
 * nmcli: limit number of printed addresses/routes in `nmcli` overview to 10.
 * Limit number of exported IP addresses/routes on D-Bus to 100 to reduce

src/core/devices/wifi/nm-device-wifi-p2p.c

@@ -15,6 +15,7 @@
 #include "NetworkManagerUtils.h"
 #include "devices/nm-device-private.h"
 #include "libnm-core-aux-intern/nm-libnm-core-utils.h"
+#include "libnm-core-aux-intern/nm-common-macros.h"
 #include "libnm-core-intern/nm-core-internal.h"
 #include "libnm-glib-aux/nm-ref-string.h"
 #include "libnm-platform/nm-platform.h"
@@ -982,23 +983,24 @@ device_state_changed(NMDevice           *device,
 }
 
 static void
-impl_device_wifi_p2p_start_find(NMDBusObject                      *obj,
+p2p_start_find_auth_cb(NMDevice              *device,
-                                const NMDBusInterfaceInfoExtended *interface_info,
-                                const NMDBusMethodInfoExtended    *method_info,
-                                GDBusConnection                   *connection,
-                                const char                        *sender,
                        GDBusMethodInvocation *invocation,
-                                GVariant                          *parameters)
+                       NMAuthSubject         *subject,
+                       GError                *error,
+                       gpointer               user_data)
 {
-    NMDeviceWifiP2P           *self    = NM_DEVICE_WIFI_P2P(obj);
+    NMDeviceWifiP2P           *self    = NM_DEVICE_WIFI_P2P(device);
     NMDeviceWifiP2PPrivate    *priv    = NM_DEVICE_WIFI_P2P_GET_PRIVATE(self);
-    gs_unref_variant GVariant *options = NULL;
+    gs_unref_variant GVariant *options = user_data;
     const char                *opts_key;
     GVariant                  *opts_val;
     GVariantIter               iter;
     gint32                     timeout = 30;
 
-    g_variant_get(parameters, "(@a{sv})", &options);
+    if (error) {
+        g_dbus_method_invocation_return_gerror(invocation, error);
+        return;
+    }
 
     g_variant_iter_init(&iter, options);
     while (g_variant_iter_next(&iter, "{&sv}", &opts_key, &opts_val)) {
@@ -1050,7 +1052,7 @@ impl_device_wifi_p2p_start_find(NMDBusObject                      *obj,
 }
 
 static void
-impl_device_wifi_p2p_stop_find(NMDBusObject                      *obj,
+impl_device_wifi_p2p_start_find(NMDBusObject                      *obj,
                                 const NMDBusInterfaceInfoExtended *interface_info,
                                 const NMDBusMethodInfoExtended    *method_info,
                                 GDBusConnection                   *connection,
@@ -1058,9 +1060,35 @@ impl_device_wifi_p2p_stop_find(NMDBusObject                      *obj,
                                 GDBusMethodInvocation             *invocation,
                                 GVariant                          *parameters)
 {
-    NMDeviceWifiP2P        *self = NM_DEVICE_WIFI_P2P(obj);
+    gs_unref_variant GVariant *options = NULL;
+
+    g_variant_get(parameters, "(@a{sv})", &options);
+
+    nm_device_auth_request(NM_DEVICE(obj),
+                           invocation,
+                           NULL,
+                           NM_AUTH_PERMISSION_WIFI_SCAN,
+                           TRUE,
+                           NULL,
+                           p2p_start_find_auth_cb,
+                           g_steal_pointer(&options));
+}
+
+static void
+p2p_stop_find_auth_cb(NMDevice              *device,
+                      GDBusMethodInvocation *invocation,
+                      NMAuthSubject         *subject,
+                      GError                *error,
+                      gpointer               user_data)
+{
+    NMDeviceWifiP2P        *self = NM_DEVICE_WIFI_P2P(device);
     NMDeviceWifiP2PPrivate *priv = NM_DEVICE_WIFI_P2P_GET_PRIVATE(self);
 
+    if (error) {
+        g_dbus_method_invocation_return_gerror(invocation, error);
+        return;
+    }
+
     if (!priv->mgmt_iface) {
         g_dbus_method_invocation_return_error_literal(
             invocation,
@@ -1075,6 +1103,25 @@ impl_device_wifi_p2p_stop_find(NMDBusObject                      *obj,
     g_dbus_method_invocation_return_value(invocation, NULL);
 }
 
+static void
+impl_device_wifi_p2p_stop_find(NMDBusObject                      *obj,
+                               const NMDBusInterfaceInfoExtended *interface_info,
+                               const NMDBusMethodInfoExtended    *method_info,
+                               GDBusConnection                   *connection,
+                               const char                        *sender,
+                               GDBusMethodInvocation             *invocation,
+                               GVariant                          *parameters)
+{
+    nm_device_auth_request(NM_DEVICE(obj),
+                           invocation,
+                           NULL,
+                           NM_AUTH_PERMISSION_WIFI_SCAN,
+                           TRUE,
+                           NULL,
+                           p2p_stop_find_auth_cb,
+                           NULL);
+}
+
 /*****************************************************************************/
 
 NMSupplicantInterface *