ref: 713beb6d423144456a458c7bb984a29ae70b3a9e 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;