Re: [edk2] MTFTP4 Protocol - Wrapping

Subject: Re: [edk2] MTFTP4 Protocol - Wrapping

From: Daniel Moral <daniel.moral@ericsson.com>

To: "edk2-devel@lists.sourceforge.net" <edk2-devel@lists.sourceforge.net>, "efidevkit-devel@lists.sourceforge.net" <efidevkit-devel@lists.sourceforge.net>

Date: 2011-11-03 21:18:49

Yes, your totally right.
 
Thank you very much for your feedback :)


From: Li, Ruth [mailto:ruth.li@intel.com]
Sent: Thursday, November 03, 2011 12:46 PM
To: edk2-devel@lists.sourceforge.net; efidevkit-devel@lists.sourceforge.net
Subject: Re: [edk2] MTFTP4 Protocol - Wrapping

Per my understanding, RFC 1350 does not describe block number roll-over. It’s the implementation choice to implement the roll-over so that to accept transfers of unlimited size. And there’s no consensus on whether wrap to 0 or 1.

In following capture file, 192.168.10.101 is the server and 192.16.10.103 is the EFI MTFTP4 Client. The server used here (an OS tftp server) is choose to wrap to 0 instead of 1. UEFI mtftp as a client, responding DATA(65535) with ACK(65535), and responding DATA(0) with ACK(0).

 

Thanks,

Ruth

From: Daniel Moral [mailto:daniel.moral@ericsson.com]
Sent: Thursday, November 03, 2011 5:47 PM
To: edk2-devel@lists.sourceforge.net; efidevkit-devel@lists.sourceforge.net
Subject: Re: [edk2] MTFTP4 Protocol - Wrapping

 

Thank you for the replies.

 

The system uses EDK1, so maybe we try to port the code.

Nevertheless, I stil do not get it, because according to the RFC, the block numbers should start with 1, not with 0.

 

BR

Daniel

 


From: Li, Ruth [mailto:ruth.li@intel.com]
Sent: Thursday, November 03, 2011 3:07 AM
To: edk2-devel@lists.sourceforge.net; efidevkit-devel@lists.sourceforge.net
Subject: Re: [edk2] MTFTP4 Protocol - Wrapping

Hi Daniel,

We tried the latest MTFTP4 driver, looks like we’re responding DATA(65535) with ACK(65536) instead of ACK(0).  Which version of EDKII you’re using?

 

 

From: Li, Ruth [mailto:ruth.li@intel.com]
Sent: Thursday, November 03, 2011 8:17 AM
To: edk2-devel@lists.sourceforge.net; efidevkit-devel@lists.sourceforge.net
Subject: Re: [edk2] MTFTP4 Protocol - Wrapping

 

Hi Daniel,

 

You’re correct. The EFI MTFTP4 protocol has the same wrapping behavior – after block 65535 and start with block 0 again.

 

Thanks,

Ruth

From: Daniel Moral [mailto:daniel.moral@ericsson.com]
Sent: Wednesday, November 02, 2011 8:48 PM
To: edk2-devel@lists.sourceforge.net; efidevkit-devel@lists.sourceforge.net
Subject: [edk2] MTFTP4 Protocol - Wrapping

 

Hi all,

 

This is a simple question in case you have worked with MTFTP4. This protocol has 2 bytes for the block sequence numbers. Therefore the maximum sequence number is 65535. Some servers, after the block 65535 has been sent, are able to wrap the numbers and start with the block number 0 again. Therefore, there would not be a file limit.

 

My question is, the MTFTP4 protocol has this behavior? Or it does not wrap numbers? (i.e it finishes in seq number 65535 and does not continue)

 

Thanks

 

BR

Daniel