s_initialize("tftp")

s_group("opcode", values=["\x00\x01","\x00\x02"])
s_group("transfertype", values=["netascii","octet","mail", "abcdabcd"])

if s_block_start("filerequest", group="opcode"):
	# filename
	s_string("ABCDABCD")
	# terminator
	s_static("\x00")
	
	if s_block_start("transtype", group="transfertype"):
		s_block_end("transtype")
		s_static("\x00")
s_block_end("filerequest")