(draft) feat: tcp transport

[Frando]

Description

Adds a TCP transport.
Mostly written as a test case for #3845. No direct intention of adding this as a public iroh feature for now.

Current code likely has issues around waker registration, will have to think it through properly.

It's public in the PR though so that I could wire it up to the iroh benchmark

cargo run --release -p iroh-bench -- iroh
[...]
Transferred 1073741824 bytes on 1 streams in 918.36ms (1115.03 MiB/s)
[...]

cargo run --release -p iroh-bench -- iroh --tcp
[...]
Transferred 1073741824 bytes on 1 streams in 1.49s (689.20 MiB/s)
[...]

edit: perf got better with the recent commits, it's at ~3/4 of regular iroh now on my machine.

So it's quite a bit slower than UDP on my machine, but that's localhost, and the code is not yet optimized.

Breaking Changes

Notes & open questions

Change checklist

• Self-review.
• Documentation updates following the style guide, if relevant.
• Tests if relevant.
• All breaking changes documented.
  • List all breaking changes in the above "Breaking Changes" section.
  • Open an issue or PR on any number0 repos that are affected by this breaking change. Give guidance on how the updates should be handled or do the actual updates themselves. The major ones are:
    • quic-rpc
    • iroh-gossip
    • iroh-blobs
    • dumbpipe
    • sendme

[github-actions]

Documentation for this PR has been generated and is available at: https://n0-computer.github.io/iroh/pr/3880/docs/iroh/

Last updated: 2026-01-24T12:45:53Z

[rklaehn]

I did a bunch of trait renames in the custom transports branch. Nothing fundamental though...