dnscore: implement DNS-over-QUIC

[bassosimone]

Overview This issue is about adding support for DNS-over-QUIC (DoQ) in the dnscore library. The goal is to enable users to perform DNS queries over QUIC using dnscore's transport and high-level APIs. In turn, this feature will be exposed to the rbmk dig tool, allowing users to perform DNS-over-QUIC queries from the command line.

Open to contributors! I currently do not have time myself to work on this issue right now, so, please, let me know if you would like to take on this task. I am willing to provide feedback, guidance, and support to land this new feature.

Proposed Activities I believe we should proceed as follows:

• write a brief summary of how DoQ works and sketch out how it could be integrated into dnscore
• pick up the proper library for QUIC in Go (most likely this would be https://github.com/quic-go/quic-go)
• sketch out initial implementation in dnscore and expose it using the ./internal/cmd/transport/ command, such that we can test the new code with existing DoQ servers
• check whether we need to update the design documents (https://github.com/rbmk-project/rbmk-project.github.io/tree/main/docs/design)
• update the rbmk command to support DoQ
• add support for structured logging to the initial implementation and see whether we need to update the spec (https://github.com/rbmk-project/rbmk-project.github.io/tree/main/docs/spec/data-format)
• write unit tests for the initial implementation following the same pattern already used for, e.g., dotls_test.go, dohttps_test.go
• add support for DoQ inside the ./dnscoretest package

This is the general idea of how I think we should proceed, but obviously we will adapt this plan as we go, if new information and reckonings come up.

Work Style

• We encourage incremental development through multiple PRs

  • Each task above can be split into smaller, focused PRs
  • Early functionality can be merged while work continues
  • Example progression:
    1. Initial discussion over here sketching out a plan
    2. Basic QUIC connection handling
    3. DNS protocol integration
    4. Structured logging implementation
    5. Test coverage expansion
    6. CLI integration

• All code changes eventually require:

  • Unit tests following existing patterns (see dotls_test.go, dohttps_test.go)
  • Documentation updates (both code and design docs)
  • Spec updates where relevant
  • Passing CI checks
  • Following Go style guidelines

• Consider using a draft PRs for early feedback and discussion

  • Share initial design thoughts and research findings
  • Discuss QUIC library selection and integration approach
  • Get feedback on implementation direction
  • Early reviews help avoid major refactoring later

• If your code is derived work from someone else's code, reference the original source code explicitly

• Always include a SPDX-License-Identifier (and use GPL-3.0-or-later for new code)

Expected Outcomes I would say:

1. dnscore includes DoQ support
2. the DoQ code is fully tested
3. the dnscoretest includes DoQ support
4. the internal/cmd/transport/ command includes DoQ support
5. we have updated all the relevant docs
6. we have released a new version of dnscore including DoQ
7. the rbmk dig tool supports DoQ

Prerequisites I think:

• knowledge of Go and networking
• familiarity with DNS
• knowledge of https://go.dev/wiki/CodeReviewComments

Getting Started

1. Comment on this issue expressing interest
2. Fork the repository and set up your development environment
3. Read through the dnscore design doc and the already-existing dnscore protocol implementations
4. Create a draft PR early to discuss implementation approach
5. Full development documentation is not available yet, but I will be working on this to facilitate future work

Communications The RBMK and dnscore projects are hobby projects for me, at the moment, so expect some delays in communication. I will try to be as responsive as possible, but please be patient. I am available to discuss on GitHub issues and pull requests, and I am also available via Matrix as @bassosimone:matrix.org.

[bassosimone]

Being worked on at rbmk-project/dnscore#18

[bassosimone]

We're making progress towards this. We have just merged rbmk-project/dnscore#19, which fixes an underlying issue with correctly setting the query ID for DoQ. Along the way, we also discovered that DoH suggests using a zero query ID for caching reasons, so we have also took care of that in such a patch. The next step is to polish the rbmk-project/dnscore#18 pull request and see to merge it into the main branch.

[bassosimone]

We're going to merge rbmk-project/dnscore#18 soon, which will give us basic DoQ support! 🥳