It doesn't make much sense to have the pluggable transport manager be a
registry, so replace its interface with a more narrowly defined, less generic
version.
Other changes:
- instead of returning a &-reference, it returns an owned Arc, which
should make the ptmgr easier to implement while allowing efficient
reuse
- provision for error handling is added, but will probably be revised in
a future commit pending discussion
- tor-ptmgr code that would generate warnings as a result of this change
is temporarily removed
This is a split out version of arti!886, intended so work on arti#659
can proceed.
This brings the draft configuration mechanisms in tor-ptmgr in line with
the config in other crates, using builders. It also plumbs the config
type through into the main `arti-client` config, and adds some example
lines to `arti-example-config.toml`.
The new `ipc` module inside `tor-ptmgr` implements the Pluggable
Transport Specification version 1 (`pt-spec.txt`,
https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/pt-spec.txt).
This enables module users to spawn pluggable transport binaries inside a
child process asynchronously, and receive structured information about
how to connect to the transports provided by said binaries.
Internally, this is structured as a pure set of serialisers and
deserialisers for the protocol in the specification (in the form of
environment variables, and the PT's stdout), a wrapper to run the PT
binary and enable accessing its output asynchronously, and a user-facing
wrapper that handles ensuring all the requested transports launched
properly.
The included `run-pt` example is an exceedingly minimal wrapper program
that was useful in testing. More tests can and should be added in a
further MR.
closes arti#394; part of arti#69
The feature we want is `#[doc = include_str!("README.md")]`, which is
stable since 1.54 and our MSRV is now 1.56.
This commit is precisely the result of the following Perl rune:
perl -i~ -0777 -pe 's{(^//!(?!.*\@\@).*\n)+}{#![doc = include_str!("../README.md")]\n}m' crates/*/src/lib.rs
The traits that launch connections need to be async; the traits that
don't, shouldn't be async.
Additionally, we need a few more "Sync" annotations here for the
futures to work.
(Since the APIs for the `Schedule::sleep*` functions changed, this
is a breaking change in tor-rtcompat. Therefore, the Runtime trait
in tor-rtcompat is now a different trait. Therefore, anything that
uses the Runtime trait in its APIs has also broken.)