Summary

Adds UDP batching for linux using recvmmsg. To close #12452

Only used on Linux. All other systems to use normal recvmsg.

Vector configuration

TODO

How did you test this PR?

cargo test in WSL & cargo test on Debian Trixie server

No test failures that were not pre-existing on those systems. Part of the reason to create this PR is to see what the CI says.

Change Type

• Bug fix
• New feature
• Dependencies
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

I left configuring the batch size etc to a later PR if such a feature is desirable. I used a conservative value of 32 for now which should be enough that everyone gets a benifit but without any substantial memory increases.

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

Closes: #12452

Notes

• Please read our Vector contributor resources.
• Do not hesitate to use @vectordotdev/vector to reach out to us regarding this PR.
• Some CI checks run only after we manually approve them.
  • We recommend adding a pre-push hook, please see this template.
  • Alternatively, we recommend running the following locally before pushing to the remote branch:
    • make fmt
    • make check-clippy (if there are failures it's possible some of them can be fixed with make clippy-fix)
    • make test
• After a review is requested, please avoid force pushes to help us review incrementally.
  • Feel free to push as many commits as you want. They will be squashed into one before merging.
  • For example, you can run git merge origin master and git push.
• If this PR introduces changes Vector dependencies (modifies Cargo.lock), please
  run make build-licenses to regenerate the license inventory and commit the changes (if any). More details on the dd-rust-license-tool.