ref: cc978d6fdb7e8ceddc92a7ed3f0f393f39c915e7 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;