th_stuff
wtail = wbuf.t.th_stuff;
cp = tp->th_stuff;
pktlen = packet_size - offsetof(struct tftphdr, th_stuff);
file = cp = tp->th_stuff;
p = (u_char *)tp->th_stuff;
opcode(ntohs(tp->th_opcode)), tp->th_stuff);
bp = (char *)tp->th_stuff;
cp = tp->th_stuff;
i = cp - tp->th_stuff;
memcpy(filename, tp->th_stuff, i);