ooni-probe-cli/internal/ptx/fake.go

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feat: introduce ptx package for pluggable transports dialers (#373) * 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: https://gitlab.torproject.org/tpo/applications/tor-browser-build/-/commit/e26e91bef8bd8d04d79bdd69f087efd808bc925d See https://github.com/ooni/probe-cli/pull/373#discussion_r649820724 Co-authored-by: Arturo Filastò <arturo@openobservatory.org>
2021-06-14 10:20:54 +02:00
package ptx
import (
"context"
"fmt"
"net"
)
// FakeDialer is a fake pluggable transport dialer. It actually
// just creates a TCP connection with the given address.
type FakeDialer struct {
// Address is the real destination address.
Address string
}
var _ PTDialer = &FakeDialer{}
// DialContext establishes a TCP connection with d.Address.
func (d *FakeDialer) DialContext(ctx context.Context) (net.Conn, error) {
return (&net.Dialer{}).DialContext(ctx, "tcp", d.Address)
}
// AsBridgeArgument returns the argument to be passed to
// the tor command line to declare this bridge.
func (d *FakeDialer) AsBridgeArgument() string {
return fmt.Sprintf("fake %s", d.Address)
}
// Name returns the pluggable transport name.
func (d *FakeDialer) Name() string {
return "fake"
}