## Description
This PR continues the refactoring of `netx` under the following principles:
1. do not break the rest of the tree and do not engage in extensive tree-wide refactoring yet
2. move under `netxlite` clearly related subpackages (e.g., `iox`, `netxmocks`)
3. move into `internal/netxlite/internal` stuff that is clearly private of `netxlite`
4. hide implementation details in `netxlite` pending new factories
5. refactor `tls` code in `netxlite` to clearly separate `crypto/tls` code from `utls` code
After each commit, I run `go test -short -race ./...` locally. Each individual commit explains what it does. I will squash, but this operation will preserve the original commit titles, so this will give further insight on each step.
## Commits
* refactor: rename netxmocks -> netxlite/mocks
Part of https://github.com/ooni/probe/issues/1591
* refactor: rename quicx -> netxlite/quicx
See https://github.com/ooni/probe/issues/1591
* refactor: rename iox -> netxlite/iox
Regenerate sources and make sure the tests pass.
See https://github.com/ooni/probe/issues/1591.
* refactor(iox): move MockableReader to netxlite/mocks
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): generator is an implementation detail
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): separate tls and utls code
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): hide most types but keep old names as legacy
With this change we avoid breaking the rest of the tree, but we start
hiding some implementation details a bit. Factories will follow.
See https://github.com/ooni/probe/issues/1591
* feat: introduce ptx package for pluggable transports dialers
Version 2 of the pluggable transports specification defines a function
that's like `Dial() (net.Conn, error`).
Because we use contexts as much as possible in `probe-cli`, we are
wrapping such an interface into a `DialContext` func.
The code for obfs4 is adapted from https://github.com/ooni/probe-cli/pull/341.
The code for snowflake is significantly easier than it is in
https://github.com/ooni/probe-cli/pull/341, because now Snowflake
supports the PTv2 spec (thanks @cohosh!).
The code for setting up a pluggable transport listener has also
been adapted from https://github.com/ooni/probe-cli/pull/341.
We cannot merge this code yet, because we need unit testing, yet the
newly added code already seems suitable for these use cases:
1. testing by dialing and seeing whether we can dial (which is not
very useful but still better than not doing it);
2. spawning tor+pluggable transports for circumvention (we need a
little more hammering like we did in https://github.com/ooni/probe-cli/pull/341,
which is basically https://github.com/ooni/probe/issues/1565, and then
we will be able to do that, as demonstrated by the new, simple client which
already allows us to use pluggable transports with tor);
3. testing by launching tor (when available) with a set of
pluggable transports (which depends on https://github.com/ooni/probe-engine/issues/897
and has not been assigned an issue yet).
* fix: tweaks after self code-review
* feat: write quick tests for ptx/obfs4
(They run in 0.4s, so I think it's fine for them to always run.)
* feat(ptx/snowflake): write unit and integration tests
* feat: create a fake PTDialer
The idea is that we'll use this simpler PTDialer for testing.
* feat: finish writing tests for new package
* Apply suggestions from code review
* Update internal/ptx/dependencies_test.go
Co-authored-by: Arturo Filastò <arturo@openobservatory.org>
* Update internal/ptx/dependencies_test.go
Co-authored-by: Arturo Filastò <arturo@openobservatory.org>
* chore: use as testing bridge one that's used by tor browser
The previous testing bridge used to be used by tor browser but
it was subsequently removed here:
e26e91bef8
See https://github.com/ooni/probe-cli/pull/373#discussion_r649820724
Co-authored-by: Arturo Filastò <arturo@openobservatory.org>
