libudev: add udev_device_new_from_devnum()

[elogind.git] / udev / lib / libudev-device.c

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index 731230efd0143858bd9da1072d60696fdbd6fd46..8103c7fcc46448c5812a5a393afa8217c9b83d7f 100644 (file)
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -216,6 +216,20 @@ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *
        return udev_device;
 }
 
+struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
+{
+       char path[UTIL_PATH_SIZE];
+
+       snprintf(path, sizeof(path), "%s/dev/%s/%u:%u",
+                udev_get_sys_path(udev),
+                type == 'b' ? "block" : "char",
+                major(devnum), minor(devnum));
+       if (util_resolve_sys_link(udev, path, sizeof(path)) < 0)
+               return NULL;
+
+       return udev_device_new_from_syspath(udev, path);
+}
+
 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
 {
        struct udev_device *udev_device_parent = NULL;