#6 Block size option < 512 is not accepted

[Anonymous]

From RFC 2348 TFTP Blocksize Option:
#octets
The number of octets in a block, specified in ASCII. Valid
values range between "8" and "65464" octets, inclusive. The
blocksize refers to the number of data octets; it does not
include the four octets of TFTP header.
...
If the server is willing to accept the blocksize option, it sends an
Option Acknowledgment (OACK) to the client. The specified value must
be less than or equal to the value specified by the client.

The issue is that Open TFTP server sends the Option Acknowledgment (OACK) to the client with a value = 512, instead of accepting the value specified by the client when this value is less than 512.