TooMuchData errors

[vbauerster]

Hello!

I tried doh-client and got following errors:

ERROR [doh_client::http2] GetResponse: DNS parser error: TooMuchData

[LinkTed]

Hi,
this error appears when the DoH server responds with a content bigger than 512 bytes. According to the RFC 1035, a DNS packet has to be 512 bytes or less. Can you tell me which DoH server you use?

[vbauerster]

I'm using unbound as front forwarding recursive queries to doh-client with a-and-a.

[LinkTed]

Can you give me a example DNS request, where this error appears. I use the following argument:

doh-client /etc/ca-certificates/extracted/tls-ca-bundle.pem -vv --remote-addr=217.169.20.23:443 --domain dns.aa.net.uk

[vbauerster]

Unfortunately I can't narrow which query is causing that, but logs suggest apparently all:

[LinkTed]

I add more debug output to the code to get the request and corresponded response. Can you use the fc18f07 commit and use the -vvv argument, please?

[vbauerster]

doh-client.log.gz

[LinkTed]

According to the RFC 6891 the maximum payload of dns packet, was increased. So i increased the size. Can you test the doh-client with the commit 72fad86 and tell me if it works? By the way, if you use unbound to cache the dns packet then you should deactivate the cache mechanism of the doh-client by using the argument -c 0.

[vbauerster]

I confirm, that it works now. Thank you for quick fix!
There are public resolvers with dns stamps available. It would be nice if doh-client would support dns stamp format as source for a resolver. For example I had to use Online DNS Stamp calculator first, in order to extract domain and ip from a stamp like sdns://AgcAAAAAAAAADTIxNy4xNjkuMjAuMjIgPhoaD2xT8-l6SS1XCEtbmAcFnuBXqxUFh2_YP9o9uDgNZG5zLmFhLm5ldC51awovZG5zLXF1ZXJ5.

[LinkTed]

Okay, thank you for the reporting.