An ACL structure type.
GFARM_ACL_FIRST_ENTRY (to get first ACL entry) or GFARM_ACL_NEXT_ENTRY (to get next ACL entry).
Pointer to get the ACL entry.
The function terminated successfully.
The ACL does not have ACL entries anymore. (End of ACL)
An error except the above occurred. The reason is shown by gfarm_error_string(3).