feat: tlsmiddlebox experiment (#817)

See https://github.com/ooni/probe/issues/2124

internal/engine/experiment/tlsmiddlebox/measurer.go

@@ -0,0 +1,115 @@
+package tlsmiddlebox
+
+//
+// Measurer
+//
+
+import (
+	"context"
+	"errors"
+	"net/url"
+	"sync"
+	"time"
+
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+const (
+	testName    = "tlsmiddlebox"
+	testVersion = "0.1.0"
+)
+
+// Measurer performs the measurement.
+type Measurer struct {
+	config Config
+}
+
+// ExperimentName implements ExperimentMeasurer.ExperimentName.
+func (m *Measurer) ExperimentName() string {
+	return testName
+}
+
+// ExperimentVersion implements ExperimentMeasurer.ExperimentVersion.
+func (m *Measurer) ExperimentVersion() string {
+	return testVersion
+}
+
+var (
+	// errNoInputProvided indicates you didn't provide any input
+	errNoInputProvided = errors.New("no input provided")
+
+	// errInputIsNotAnURL indicates that input is not an URL
+	errInputIsNotAnURL = errors.New("input is not an URL")
+
+	// errInvalidInputScheme indicates that the input scheme is invalid
+	errInvalidInputScheme = errors.New("input scheme must be tlstrace")
+
+	// errInvalidTestHelper indicates that the testhelper is invalid
+	errInvalidTestHelper = errors.New("invalid testhelper")
+
+	// errInvalidTHScheme indicates that the TH scheme is invalid
+	errInvalidTHScheme = errors.New("th scheme must be tlshandshake")
+)
+
+// // Run implements ExperimentMeasurer.Run.
+func (m *Measurer) Run(
+	ctx context.Context,
+	sess model.ExperimentSession,
+	measurement *model.Measurement,
+	callbacks model.ExperimentCallbacks,
+) error {
+	if measurement.Input == "" {
+		return errNoInputProvided
+	}
+	parsed, err := url.Parse(string(measurement.Input))
+	if err != nil {
+		return errInputIsNotAnURL
+	}
+	if parsed.Scheme != "tlstrace" {
+		return errInvalidInputScheme
+	}
+	th, err := m.config.testhelper(parsed.Host)
+	if err != nil {
+		return errInvalidTestHelper
+	}
+	if th.Scheme != "tlshandshake" {
+		return errInvalidTHScheme
+	}
+	tk := NewTestKeys()
+	measurement.TestKeys = tk
+	wg := new(sync.WaitGroup)
+	// 1. perform a DNSLookup
+	addrs, err := m.DNSLookup(ctx, 0, measurement.MeasurementStartTimeSaved, sess.Logger(), th.Hostname(), tk)
+	if err != nil {
+		return err
+	}
+	// 2. measure addresses
+	addrs = prepareAddrs(addrs, th.Port())
+	for i, addr := range addrs {
+		wg.Add(1)
+		go m.TraceAddress(ctx, int64(i), measurement.MeasurementStartTimeSaved, sess.Logger(), addr, parsed.Hostname(), tk, wg)
+	}
+	wg.Wait()
+	return nil
+}
+
+// TraceAddress measures a single address after the DNSLookup
+func (m *Measurer) TraceAddress(ctx context.Context, index int64, zeroTime time.Time, logger model.Logger,
+	address string, sni string, tk *TestKeys, wg *sync.WaitGroup) error {
+	defer wg.Done()
+	trace := &CompleteTrace{
+		Address: address,
+	}
+	tk.addTrace(trace)
+	err := m.TCPConnect(ctx, index, zeroTime, logger, address, tk)
+	if err != nil {
+		return err // skip tracing if we cannot connect with default TTL
+	}
+	m.TLSTrace(ctx, index, zeroTime, logger, address, sni, trace)
+	return nil
+}
+
+// NewExperimentMeasurer creates a new ExperimentMeasurer.
+func NewExperimentMeasurer(config Config) *Measurer {
+	return &Measurer{config: config}
+}