wifi: don't fail construction of NMDeviceWifi in constructor

We cannot abort the construction of a GLib object instance
like we did for NMDeviceWifi and NMDeviceOlpcMesh when
nm_platform_wifi_get_capabilities() failed.

Instead, check the capabilities first (in the factory method)
and only create the object instance when the device can be handled.

https://bugzilla.gnome.org/show_bug.cgi?id=760154
(cherry picked from commit 044de4cea2)

src/devices/wifi/nm-device-olpc-mesh.c

@@ -447,22 +447,14 @@ constructor (GType type,
 	GObjectClass *klass;
 	NMDeviceOlpcMesh *self;
 	NMDeviceOlpcMeshPrivate *priv;
-	NMDeviceWifiCapabilities caps;
 
 	klass = G_OBJECT_CLASS (nm_device_olpc_mesh_parent_class);
 	object = klass->constructor (type, n_construct_params, construct_params);
-	if (!object)
-		return NULL;
+	g_return_val_if_fail (object, NULL);
 
 	self = NM_DEVICE_OLPC_MESH (object);
 	priv = NM_DEVICE_OLPC_MESH_GET_PRIVATE (self);
 
-	if (!nm_platform_wifi_get_capabilities (NM_PLATFORM_GET, nm_device_get_ifindex (NM_DEVICE (self)), &caps)) {
-		_LOGW (LOGD_HW | LOGD_OLPC, "failed to initialize WiFi driver");
-		g_object_unref (object);
-		return NULL;
-	}
-
 	priv->manager = g_object_ref (nm_manager_get ());
 
 	g_signal_connect (priv->manager, "device-added", G_CALLBACK (device_added_cb), self);

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

@@ -201,20 +201,11 @@ constructor (GType type,
 
 	klass = G_OBJECT_CLASS (nm_device_wifi_parent_class);
 	object = klass->constructor (type, n_construct_params, construct_params);
-	if (!object)
-		return NULL;
+	g_return_val_if_fail (object, NULL);
 
 	self = NM_DEVICE_WIFI (object);
 	priv = NM_DEVICE_WIFI_GET_PRIVATE (self);
 
-	if (!nm_platform_wifi_get_capabilities (NM_PLATFORM_GET,
-	                                        nm_device_get_ifindex (NM_DEVICE (self)),
-	                                        &priv->capabilities)) {
-		_LOGW (LOGD_HW | LOGD_WIFI, "failed to initialize WiFi driver");
-		g_object_unref (object);
-		return NULL;
-	}
-
 	if (priv->capabilities & NM_WIFI_DEVICE_CAP_AP)
 		_LOGI (LOGD_HW | LOGD_WIFI, "driver supports Access Point (AP) mode");
 
@@ -3196,7 +3187,7 @@ set_enabled (NMDevice *device, gboolean enabled)
 /********************************************************************/
 
 NMDevice *
-nm_device_wifi_new (NMPlatformLink *platform_device)
+nm_device_wifi_new (NMPlatformLink *platform_device, NMDeviceWifiCapabilities capabilities)
 {
 	g_return_val_if_fail (platform_device != NULL, NULL);
 
@@ -3205,6 +3196,7 @@ nm_device_wifi_new (NMPlatformLink *platform_device)
 	                                  NM_DEVICE_TYPE_DESC, "802.11 WiFi",
 	                                  NM_DEVICE_DEVICE_TYPE, NM_DEVICE_TYPE_WIFI,
 	                                  NM_DEVICE_RFKILL_TYPE, RFKILL_TYPE_WLAN,
+	                                  NM_DEVICE_WIFI_CAPABILITIES, (guint) capabilities,
 	                                  NULL);
 }
 
@@ -3296,7 +3288,14 @@ static void
 set_property (GObject *object, guint prop_id,
               const GValue *value, GParamSpec *pspec)
 {
+	NMDeviceWifi *device = NM_DEVICE_WIFI (object);
+	NMDeviceWifiPrivate *priv = NM_DEVICE_WIFI_GET_PRIVATE (device);
+
 	switch (prop_id) {
+	case PROP_CAPABILITIES:
+		/* construct-only */
+		priv->capabilities = g_value_get_uint (value);
+		break;
 	default:
 		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 		break;
@@ -3381,7 +3380,8 @@ nm_device_wifi_class_init (NMDeviceWifiClass *klass)
 		(object_class, PROP_CAPABILITIES,
 		 g_param_spec_uint (NM_DEVICE_WIFI_CAPABILITIES, "", "",
 		                    0, G_MAXUINT32, NM_WIFI_DEVICE_CAP_NONE,
-		                    G_PARAM_READABLE |
+		                    G_PARAM_READWRITE |
+		                    G_PARAM_CONSTRUCT_ONLY |
 		                    G_PARAM_STATIC_STRINGS));
 
 	g_object_class_install_property

src/devices/wifi/nm-device-wifi.h

@@ -75,7 +75,7 @@ struct _NMDeviceWifiClass
 
 GType nm_device_wifi_get_type (void);
 
-NMDevice *nm_device_wifi_new (NMPlatformLink *platform_device);
+NMDevice *nm_device_wifi_new (NMPlatformLink *platform_device, NMDeviceWifiCapabilities capabilities);
 
 G_END_DECLS
 

src/devices/wifi/nm-wifi-factory.c

@@ -29,6 +29,8 @@
 #include "nm-device-olpc-mesh.h"
 #include "nm-settings-connection.h"
 #include "nm-platform.h"
+#include "nm-macros-internal.h"
+#include "nm-logging.h"
 
 #define NM_TYPE_WIFI_FACTORY (nm_wifi_factory_get_type ())
 #define NM_WIFI_FACTORY(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), NM_TYPE_WIFI_FACTORY, NMWifiFactory))
@@ -61,11 +63,22 @@ nm_device_factory_create (GError **error)
 static NMDevice *
 new_link (NMDeviceFactory *factory, NMPlatformLink *plink, gboolean *out_ignore, GError **error)
 {
+	NMDeviceWifiCapabilities capabilities;
+
+	g_return_val_if_fail (plink != NULL, NULL);
+	g_return_val_if_fail (NM_IN_SET (plink->type, NM_LINK_TYPE_WIFI, NM_LINK_TYPE_OLPC_MESH), NULL);
+
+	if (!nm_platform_wifi_get_capabilities (NM_PLATFORM_GET,
+	                                        plink->ifindex,
+	                                        &capabilities)) {
+		nm_log_warn (LOGD_HW | LOGD_WIFI, "(%s) failed to initialize Wi-Fi driver for ifindex %d", plink->name, plink->ifindex);
+		return NULL;
+	}
+
 	if (plink->type == NM_LINK_TYPE_WIFI)
-		return nm_device_wifi_new (plink);
-	else if (plink->type == NM_LINK_TYPE_OLPC_MESH)
+		return nm_device_wifi_new (plink, capabilities);
+	else
 		return nm_device_olpc_mesh_new (plink);
-	g_assert_not_reached ();
 }
 
 NM_DEVICE_FACTORY_DECLARE_TYPES (