ref: 9d471caaae56a734728c3b19755adfe26f6c4f4c dir: /sys/src/ape/lib/bsd/in6_addr.c/
#include <netinet/in.h> struct in6_addr in6addr_any = IN6ADDR_ANY_INIT; struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;