Option to send Duplicate Data Packets

[lupyuen]

Hi: Thank you so much for the excellent work on rs-tftpd! Your project was very helpful for troubleshooting a strange TFTP Timeout problem on a RISC-V SBC (Star64), I wrote about it below. Thanks again! :-)

• "Strange Workaround for TFTP Timeout in U-Boot Bootloader (Star64 JH7110 RISC-V SBC)"

[altugbakan]

Hello!

Thank you so much for using rs-tftpd on an environment! My idea for building this was actually to use it with u-boot at work. Do you think adding a burst-sending option can be helpful for things like this? We can add a new flag for resending all packets every time.

Do you think this would be a helpful addition? Did you have any other issues while working? Thanks again!

[lupyuen]

Great to hear that we're both having U-Boot TFTP issues :-)

Yes it would be very helpful to have a Command-Line Option that will send Duplicate Data Packets! I wonder if we need a Delay between the Duplicate Packets, should that be another option? (I inserted a 1 millisecond delay between Duplicate Packets)

rs-tftpd works great for me, I have no other requests. (Though I'm still trying to figure out how to install it as a Linux Service)

This U-Boot TFTP Timeout issue feels very strange. I hope it's not something simple that I missed, like a faulty network cable :-)

[acassis]

@lupyuen did you compare rs-tftpd against the default tftpd package from Ubuntu/Debian? Is this issue happening with this tftpd as well?

[lupyuen]

@acassis Yes I saw the same TFTP Timeout when using the standard xinetd + tftpd on Raspberry Pi 4 (32-bit Debian): https://lupyuen.github.io/articles/tftp2#all-things-considered

I have a hunch that it's something inside U-Boot for JH7110 that's dropping UDP Packets, causing Resends and Timeouts.

[altugbakan]

Hey @lupyuen! I added a pre-release for supporting duplicate packets. You can use tftpd --duplicate-packets <NUM> to make the server send packets more than once.

If you have time, would you be so kind to try it and see if it is working as you intended? Thanks!

[lupyuen]

@altugbakan Thank you so much! It seems we need to insert a delay between duplicate packets: https://github.com/altugbakan/rs-tftpd/pull/7

Also I hope I got this right: The option --duplicate-packets 2 will actually send 1 original + 1 duplicate packet?

Wonder if we might confuse folks? Should we shift it to --duplicate-packets 1?

Thanks again for adding this option, we finally have a proper solution for our U-Boot issue :-)

[stappersg]

On Sun, Oct 08, 2023 at 01:16:59AM -0700, Lup Yuen Lee wrote:

Also I hope I got this right: The option --duplicate-packets 2 will actually send 1 original + 1 duplicate packet?

Wonder if we might confuse folks? Should we shift it to --duplicate-packets 1?

For what it is worth: I prefer '--duplicate-packets 1' for original packet and one duplicate.

So also --duplicate-packets 2 for orig plus two extras.

After all is without the duplicate packets option without duplicates.

Groeten Geert Stappers -- Silence is hard to parse

[altugbakan]

I think changing the duplicate packets option with the number of duplicate packets makes more sense, thanks! I also will try to add a default delay.

[altugbakan]

Added with #7