This is xnu-4903.221.2. See this file in:
Directory listing for xnu-4903.221.2//security
Makefile
_label.h
conf/
mac.h
mac_alloc.c
mac_alloc.h
mac_audit.c
mac_base.c
mac_data.c
mac_data.h
mac_file.c
mac_framework.h
mac_inet.c
mac_internal.h
mac_iokit.c
mac_kext.c
mac_label.c
mac_mach.c
mac_mach_internal.h
mac_net.c
mac_pipe.c
mac_policy.h
mac_posix_sem.c
mac_posix_shm.c
mac_priv.c
mac_process.c
mac_pty.c
mac_skywalk.c
mac_socket.c
mac_system.c
mac_sysv_msg.c
mac_sysv_sem.c
mac_sysv_shm.c
mac_vfs.c
mac_vfs_subr.c