device: suppress logging and return error reason from nm_device_generate_connection()th/assume-master-rh1452062

Don't log in a function that basically just inspects state, without
mutating it. Instead, pass the reason why a connection could not be
generated to the caller so that we have one sensible log message.

3 files changed, 33 insertions, 28 deletions

diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index c0b4905ddf..6ff2d8684c 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -4007,27 +4007,32 @@ nm_device_master_update_slave_connection (NMDevice *self,
 }
 
 NMConnection *
-nm_device_generate_connection (NMDevice *self, NMDevice *master)
+nm_device_generate_connection (NMDevice *self, NMDevice *master, GError **error)
 {
 	NMDeviceClass *klass = NM_DEVICE_GET_CLASS (self);
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
 	const char *ifname = nm_device_get_iface (self);
-	NMConnection *connection;
+	gs_unref_object NMConnection *connection = NULL;
 	NMSetting *s_con;
 	NMSetting *s_ip4;
 	NMSetting *s_ip6;
 	char uuid[37];
 	const char *ip4_method, *ip6_method;
-	GError *error = NULL;
+	GError *local = NULL;
 	const NMPlatformLink *pllink;
 
 	/* If update_connection() is not implemented, just fail. */
-	if (!klass->update_connection)
+	if (!klass->update_connection) {
+		g_set_error (error, NM_DEVICE_ERROR, NM_DEVICE_ERROR_FAILED,
+		             "device class %s does not support generating a connection",
+		             G_OBJECT_TYPE_NAME (self));
 		return NULL;
+	}
 
 	/* Return NULL if device is unconfigured. */
 	if (!device_has_config (self)) {
-		_LOGD (LOGD_DEVICE, "device has no existing configuration");
+		g_set_error (error, NM_DEVICE_ERROR, NM_DEVICE_ERROR_FAILED,
+		             "device has no existing configuration");
 		return NULL;
 	}
 
@@ -4050,12 +4055,11 @@ nm_device_generate_connection (NMDevice *self, NMDevice *master)
 		if (!nm_device_master_update_slave_connection (master,
 		                                               self,
 		                                               connection,
-		                                               &error))
-		{
-			_LOGE (LOGD_DEVICE, "master device '%s' failed to update slave connection: %s",
-			       nm_device_get_iface (master), error->message);
-			g_error_free (error);
-			g_object_unref (connection);
+		                                               &local)) {
+			g_set_error (error, NM_DEVICE_ERROR, NM_DEVICE_ERROR_FAILED,
+			             "master device '%s' failed to update slave connection: %s",
+			             nm_device_get_iface (master), local->message);
+			g_error_free (local);
 			return NULL;
 		}
 	} else {
@@ -4068,7 +4072,6 @@ nm_device_generate_connection (NMDevice *self, NMDevice *master)
 
 		pllink = nm_platform_link_get (nm_device_get_platform (self), priv->ifindex);
 		if (pllink && pllink->inet6_token.id) {
-			_LOGD (LOGD_IP6, "IPv6 tokenized identifier present");
 			g_object_set (s_ip6,
 			              NM_SETTING_IP6_CONFIG_ADDR_GEN_MODE, NM_IN6_ADDR_GEN_MODE_EUI64,
 			              NM_SETTING_IP6_CONFIG_TOKEN, nm_utils_inet6_interface_identifier_to_token (pllink->inet6_token, NULL),
@@ -4078,11 +4081,11 @@ nm_device_generate_connection (NMDevice *self, NMDevice *master)
 
 	klass->update_connection (self, connection);
 
-	/* Check the connection in case of update_connection() bug. */
-	if (!nm_connection_verify (connection, &error)) {
-		_LOGE (LOGD_DEVICE, "Generated connection does not verify: %s", error->message);
-		g_clear_error (&error);
-		g_object_unref (connection);
+	if (!nm_connection_verify (connection, &local)) {
+		g_set_error (error, NM_DEVICE_ERROR, NM_DEVICE_ERROR_FAILED,
+		             "generated connection does not verify: %s",
+		             local->message);
+		g_error_free (local);
 		return NULL;
 	}
 
@@ -4095,26 +4098,26 @@ nm_device_generate_connection (NMDevice *self, NMDevice *master)
 	    && g_strcmp0 (ip6_method, NM_SETTING_IP6_CONFIG_METHOD_IGNORE) == 0
 	    && !nm_setting_connection_get_master (NM_SETTING_CONNECTION (s_con))
 	    && c_list_is_empty (&priv->slaves)) {
-		_LOGD (LOGD_DEVICE, "ignoring generated connection (no IP and not in master-slave relationship)");
-		g_object_unref (connection);
-		connection = NULL;
+		g_set_error_literal (error, NM_DEVICE_ERROR, NM_DEVICE_ERROR_FAILED,
+		                     "ignoring generated connection (no IP and not in master-slave relationship)");
+		return NULL;
 	}
 
 	/* Ignore any IPv6LL-only, not master connections without slaves,
 	 * unless they are in the assume-ipv6ll-only list.
 	 */
-	if (   connection
-	    && g_strcmp0 (ip4_method, NM_SETTING_IP4_CONFIG_METHOD_DISABLED) == 0
+	if (   g_strcmp0 (ip4_method, NM_SETTING_IP4_CONFIG_METHOD_DISABLED) == 0
 	    && g_strcmp0 (ip6_method, NM_SETTING_IP6_CONFIG_METHOD_LINK_LOCAL) == 0
 	    && !nm_setting_connection_get_master (NM_SETTING_CONNECTION (s_con))
 	    && c_list_is_empty (&priv->slaves)
 	    && !nm_config_data_get_assume_ipv6ll_only (NM_CONFIG_GET_DATA, self)) {
 		_LOGD (LOGD_DEVICE, "ignoring generated connection (IPv6LL-only and not in master-slave relationship)");
-		g_object_unref (connection);
-		connection = NULL;
+		g_set_error_literal (error, NM_DEVICE_ERROR, NM_DEVICE_ERROR_FAILED,
+		                    "ignoring generated connection (IPv6LL-only and not in master-slave relationship)");
+		return NULL;
 	}
 
-	return connection;
+	return g_steal_pointer (&connection);
 }
 
 gboolean
diff --git a/src/devices/nm-device.h b/src/devices/nm-device.h
index 1cdeb14768..56fea3a25d 100644
--- a/src/devices/nm-device.h
+++ b/src/devices/nm-device.h
@@ -496,7 +496,7 @@ void            nm_device_removed               (NMDevice *self, gboolean unconf
 gboolean        nm_device_is_available          (NMDevice *dev, NMDeviceCheckDevAvailableFlags flags);
 gboolean        nm_device_has_carrier           (NMDevice *dev);
 
-NMConnection * nm_device_generate_connection (NMDevice *self, NMDevice *master);
+NMConnection * nm_device_generate_connection (NMDevice *self, NMDevice *master, GError **error);
 
 gboolean nm_device_master_update_slave_connection (NMDevice *master,
                                                    NMDevice *slave,
diff --git a/src/nm-manager.c b/src/nm-manager.c
index 0d767e4f32..6152607fe3 100644
--- a/src/nm-manager.c
+++ b/src/nm-manager.c
@@ -1773,9 +1773,11 @@ get_existing_connection (NMManager *self,
 	 * update_connection() implemented, otherwise nm_device_generate_connection()
 	 * returns NULL.
 	 */
-	connection = nm_device_generate_connection (device, master);
+	connection = nm_device_generate_connection (device, master, &error);
 	if (!connection) {
-		_LOG2D (LOGD_DEVICE, device, "assume: don't assume due to failure to generate connection");
+		_LOG2D (LOGD_DEVICE, device, "assume: cannot generate connection: %s",
+		        error->message);
+		g_error_free (error);
 		return NULL;
 	}