ICMP6ECHOTMLEN
cp = buf + off + ICMP6ECHOLEN + ICMP6ECHOTMLEN;
dp = outpack + ICMP6ECHOLEN + ICMP6ECHOTMLEN;
#define DEFDATALEN ICMP6ECHOTMLEN
datap = &outpack[ICMP6ECHOLEN + ICMP6ECHOTMLEN];
if ((options & F_PINGFILLED) != 0 && datalen <= (int)ICMP6ECHOTMLEN) {