libudev: device - use DEVMODE from kernel as the default mode

TODO

@@ -1,5 +1,3 @@
- - support kernel-supplied DEVMODE=
-
  - /run/udev/control socket
 
  - read settle_timout from udev.conf

libudev/libudev-device.c

@@ -51,6 +51,7 @@ struct udev_device {
 	char *sysname;
 	const char *sysnum;
 	char *devnode;
+	mode_t devnode_mode;
 	char *subsystem;
 	char *devtype;
 	char *driver;
@@ -199,6 +200,8 @@ void udev_device_add_property_from_string_parse(struct udev_device *udev_device,
 		udev_device_set_timeout(udev_device, strtoull(&property[8], NULL, 10));
 	} else if (strncmp(property, "IFINDEX=", 8) == 0) {
 		udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
+	} else if (strncmp(property, "DEVMODE=", 8) == 0) {
+		udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
 	} else {
 		udev_device_add_property_from_string(udev_device, property);
 	}
@@ -343,6 +346,8 @@ int udev_device_read_uevent_file(struct udev_device *udev_device)
 			udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
 		else if (strncmp(line, "DEVNAME=", 8) == 0)
 			udev_device_set_knodename(udev_device, &line[8]);
+		else if (strncmp(line, "DEVMODE=", 8) == 0)
+			udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
 
 		udev_device_add_property_from_string(udev_device, line);
 	}
@@ -930,6 +935,13 @@ const char *udev_device_get_devnode(struct udev_device *udev_device)
 	return udev_device->devnode;
 }
 
+mode_t udev_device_get_devnode_mode(struct udev_device *udev_device)
+{
+	if (!udev_device->info_loaded)
+		udev_device_read_uevent_file(udev_device);
+	return udev_device->devnode_mode;
+}
+
 /**
  * udev_device_get_subsystem:
  * @udev_device: udev device
@@ -1414,6 +1426,16 @@ int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode
 	return 0;
 }
 
+int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode)
+{
+	char num[32];
+
+	udev_device->devnode_mode = mode;
+	snprintf(num, sizeof(num), "%#o", mode);
+	udev_device_add_property(udev_device, "DEVMODE", num);
+	return 0;
+}
+
 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink, int unique)
 {
 	struct udev_list_entry *list_entry;

libudev/libudev-private.h

@@ -69,6 +69,8 @@ struct udev_list_entry *udev_get_properties_list_entry(struct udev *udev);
 /* libudev-device.c */
 struct udev_device *udev_device_new(struct udev *udev);
 struct udev_device *udev_device_new_from_id_filename(struct udev *udev, char *id);
+mode_t udev_device_get_devnode_mode(struct udev_device *udev_device);
+int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode);
 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath);
 int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem);
 int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype);

libudev/test-libudev.c

@@ -221,7 +221,7 @@ static int test_enumerate_print_list(struct udev_enumerate *enumerate)
 
 static int test_monitor(struct udev *udev)
 {
-	struct udev_monitor *udev_monitor;
+	struct udev_monitor *udev_monitor = NULL;
 	int fd_ep;
 	int fd_udev = -1;
 	struct epoll_event ep_udev, ep_stdin;

test/udev-test.pl

@@ -1487,7 +1487,7 @@ EOF
 		subsys		=> "block",
 		devpath		=> "/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda",
 		exp_name	=> "sda",
-		exp_perms	=> "0:0:0600",
+		exp_perms	=> "0:0:0440",
 		exp_rem_error	=> "yes",
 		rules		=> <<EOF
 KERNEL=="sda", MODE="440"

udev/udev-event.c

@@ -43,7 +43,6 @@ struct udev_event *udev_event_new(struct udev_device *dev)
 	event = calloc(1, sizeof(struct udev_event));
 	if (event == NULL)
 		return NULL;
-	event->mode = 0600;
 	event->dev = dev;
 	event->udev = udev_device_get_udev(dev);
 	udev_list_init(&event->run_list);
@@ -1021,9 +1020,18 @@ int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules,
 			if (event->dev_db != NULL)
 				udev_node_update_old_links(dev, event->dev_db);
 
-			/* change default 0600 to 0660 if a group is assigned */
+			if (!event->mode_set) {
-			if (event->mode == 0600 && event->gid > 0)
+				if (udev_device_get_devnode_mode(dev) > 0) {
-				event->mode = 0660;
+					/* kernel supplied value */
+					event->mode = udev_device_get_devnode_mode(dev);
+				} else if (event->gid > 0) {
+					/* default 0660 if a group is assigned */
+					event->mode = 0660;
+				} else {
+					/* default 0600 */
+					event->mode = 0600;
+				}
+			}
 
 			err = udev_node_add(dev, event->mode, event->uid, event->gid);
 		}

udev/udev-rules.c

@@ -2443,19 +2443,22 @@ int udev_rules_apply_to_event(struct udev_rules *rules, struct udev_event *event
 			}
 		case TK_A_MODE:
 			{
-				char mode[UTIL_NAME_SIZE];
+				char mode_str[UTIL_NAME_SIZE];
+				mode_t mode;
 				char *endptr;
 
 				if (event->mode_final)
 					break;
+				udev_event_apply_format(event, &rules->buf[cur->key.value_off], mode_str, sizeof(mode_str));
+				mode = strtol(mode_str, &endptr, 8);
+				if (endptr[0] != '\0') {
+					err(event->udev, "ignoring invalid mode '%s'\n", mode_str);
+					break;
+				}
 				if (cur->key.op == OP_ASSIGN_FINAL)
 					event->mode_final = true;
-				udev_event_apply_format(event, &rules->buf[cur->key.value_off], mode, sizeof(mode));
+				event->mode_set = true;
-				event->mode = strtol(mode, &endptr, 8);
+				event->mode = mode;
-				if (endptr[0] != '\0') {
-					err(event->udev, "invalide mode '%s' set default mode 0600\n", mode);
-					event->mode = 0600;
-				}
 				info(event->udev, "MODE %#o %s:%u\n",
 				     event->mode,
 				     &rules->buf[rule->rule.filename_off],
@@ -2489,6 +2492,7 @@ int udev_rules_apply_to_event(struct udev_rules *rules, struct udev_event *event
 				break;
 			if (cur->key.op == OP_ASSIGN_FINAL)
 				event->mode_final = true;
+			event->mode_set = true;
 			event->mode = cur->key.mode;
 			info(event->udev, "MODE %#o %s:%u\n",
 			     event->mode,

udev/udev.h

@@ -49,6 +49,7 @@ struct udev_event {
 	bool inotify_watch_final;
 	bool group_final;
 	bool owner_final;
+	bool mode_set;
 	bool mode_final;
 	bool name_final;
 	bool devlink_final;