NAME

       NS_GET_OWNER_UID - discovering the owner of a user namespace

SYNOPSIS

       #include <linux/nsfs.h>  /* Definition of NS_GET_OWNER_UID */
       #include <sys/ioctl.h>

       int ioctl(int fd, NS_GET_OWNER_UID, uid_t *uid);

DESCRIPTION

       The  NS_GET_OWNER_UID  operation  can  be  used  to  discover  the owner user ID of a user
       namespace (i.e., the effective user ID of the process that created the user namespace).

       fd refers to a /proc/pid/ns/user file.

       The owner user ID is returned in the uid_t pointed to by the third argument.

RETURN VALUE

       On success, 0 is returned.  On error, -1 is returned, and errno is  set  to  indicate  the
       error.

ERRORS

       EINVAL fd does not refer to a user namespace.

STANDARDS

       Linux.

HISTORY

       Linux 4.11.

SEE ALSO

       ioctl(2), ioctl_nsfs(2)