This fleshes out the PtReactor that was previously a stub, making it
actually do reactor-ey things. Note that this is entirely untested, and
might not work at all. Hopefully it does, though.
This makes a `pt_state` directory inside .local/share/arti (or the
local equivalent), right next to our existing `state` dir.
Ideally we would use a separate directory for each PT, but we have a
very fuzzy "what is a specific PT" notion.
Closes#667
I prefer that it not take `&mut self`, since PtMgr already has
interior mutability.
I also need it to take `tor_config::Reconfigure` argument, in case
it gains any more smarts about validation in the future.
These are implementation details and we don't want to mark them as
stable.
To do this, I needed to apply some additional options to the example
code's configuration in Cargo.toml.
This commit implements `PtMgr`, a pluggable transport manager
responsible for keeping track of spawned PTs and spawning them to
satisfy client requests on demand.
It does this in two parts: the `PtMgr` type exported to the rest of the
code, and the background `PtReactor` that actually does the spawning;
this design ensures that only one attempt to spawn a PT is active at a
time, and will prove useful later for implementing e.g. timeouts.
A few changes were necessary to the rest of the code in order to make
this all work out. Namely:
- `TransportRegistry`'s API didn't make any sense for two reasons:
- It wasn't feasible for implementors to implement `ChannelFactory`,
since that'd require constructing a `ChanBuilder` (which requires a
bootstrap reporting event sender).
- Treating the PT manager as a registry is over-general; it's only
necessary for it to spawn pluggable transports, so saddling it with
other concerns didn't make any sense.
- (It's possible to get extensibility for arbitrary user customization
by just letting the user swap in a new `ChannelFactory`, anyway.)
- Therefore, the `PtMgr` implements the new `AbstractPtMgr` trait, which
is far more narrowly focused; this only exists to solve a dependency
loop, and is documented as such.
- This provides a `TransportHelper` instead of a `ChannelFactory`.
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.)
Ian Jackson
Nick Mathewson
eta
Ian Jackson
trinity-1686a