This is xnu-6153.11.26. See this file in:
Directory listing for xnu-6153.11.26//bsd/netinet6
Makefile
ah.h
ah6.h
ah_core.c
ah_input.c
ah_output.c
dest6.c
esp.h
esp6.h
esp_chachapoly.c
esp_chachapoly.h
esp_core.c
esp_input.c
esp_output.c
esp_rijndael.c
esp_rijndael.h
frag6.c
icmp6.c
icmp6.h
in6.c
in6.h
in6_cga.c
in6_cksum.c
in6_gif.c
in6_gif.h
in6_ifattach.c
in6_ifattach.h
in6_mcast.c
in6_pcb.c
in6_pcb.h
in6_proto.c
in6_rmx.c
in6_src.c
in6_var.h
ip6.h
ip6_ecn.h
ip6_forward.c
ip6_fw.c
ip6_fw.h
ip6_id.c
ip6_input.c
ip6_output.c
ip6_var.h
ip6protosw.h
ipcomp.h
ipsec.c
ipsec.h
ipsec6.h
mld6.c
mld6.h
mld6_var.h
nd6.c
nd6.h
nd6_nbr.c
nd6_prproxy.c
nd6_rtr.c
nd6_send.c
nd6_var.h
raw_ip6.c
raw_ip6.h
route6.c
scope6.c
scope6_var.h
tcp6_var.h
udp6_output.c
udp6_usrreq.c
udp6_var.h