RELAY_BUFSZ
char ibuff[RELAY_BUFSZ];
char obuff[RELAY_BUFSZ];
if (irh < (ibuff + RELAY_BUFSZ))
if (iwh < (obuff + RELAY_BUFSZ))
rw = read(ifd, irh, ibuff + RELAY_BUFSZ - irh);
rw = read(rfd, iwh, obuff + RELAY_BUFSZ - iwh);