PUT4
#define PUT8(p,a) do {PUT4(p,a);PUT4(p+4,a>>32);} while(0)
PUT4(ext + 16, log->ccrc);
PUT4(ext + 20, log->clen);
PUT4(ext + 24, log->tcrc);
PUT4(ext + 28, log->tlen);
PUT4(buf, log->tcrc);
PUT4(buf + 4, log->tlen);
PUT4(buf, log->tcrc);
PUT4(buf + 4, log->tlen);