ShortInput error while querying for A records

[glts]

The following program (adapted from the ‘sync’ example in domain-resolv) panics:

use domain::{
    base::{name::Dname, Rtype},
    rdata::AllRecordData,
};
use domain_resolv::StubResolver;
use std::str::FromStr;

fn main() {
    let name = Dname::<Vec<_>>::from_str("imsavscan.netvigator.com").unwrap();

    let res = StubResolver::run(move |stub| async move {
        stub.query((name, Rtype::A)).await
    });

    let res = res.unwrap();
    let res = res.answer().unwrap().limit_to::<AllRecordData<_, _>>();
    for record in res {
        let record = record.unwrap();
        println!("{}", record);
    }
}

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ShortInput', src/main.rs:18:22

It’s just a query for A records of domain imsavscan.netvigator.com.

It looks like the answer contains defective records? However, other DNS resolvers that I have tried do not indicate an error with this query, so I’m wondering if this could be a bug in domain-resolv? I could not investigate further, apologies for the simple bug report.

[partim]

Curiously, it works on my machine. The response is fairly big, though. So there might be some truncation issues, perhaps caused by a NAT box along the way or some such. We do indeed currently not check for this case.

I will add a check for completeness of the message.

[partim]

In the mean time, if you need a quick workaround, you could enable the use_vc option for the stub resolver config. This should force TCP and avoid truncation.

[glts]

Thank you, that works. (I can reproduce this both on my machine at home and on a virtual private server in a data centre somewhere, by the way.)

[partim]

Would you perchance be able to run dig +ignore +bufsize=1472 imsavscan.netvigator.com on an affected machine and paste the output (perhaps cutting out the answer section if it is just a bunch of A records)?

[partim]

Scratch that. Can you try again with the udp-buffer-size branch?

I seem to have used a different UDP buffer size than I actually advertised.

[glts]

On the branch I now see one more record line printed, and no panic. Great!

[partim]

This has been fixed in #71.