ifa_xmsghdr
struct ifa_xmsghdr *ifam;
ifam = (struct ifa_xmsghdr *)w->w_tmem;
return sizeof(struct ifa_xmsghdr);
CTASSERT(sizeof(struct ifa_xmsghdr) == 20);
CTASSERT(sizeof(struct ifa_xmsghdr) == 32);
struct ifa_xmsghdr ifam;
mtod(m, struct ifa_xmsghdr *)->ifam_addrs =