feat(webconnectivity): long-term-evolution prototype (#882)

See https://github.com/ooni/probe/issues/2237

internal/experiment/webconnectivity/measurer.go

@@ -0,0 +1,135 @@
+package webconnectivity
+
+//
+// Measurer
+//
+
+import (
+	"context"
+	"errors"
+	"net/http/cookiejar"
+	"sync"
+
+	"github.com/ooni/probe-cli/v3/internal/atomicx"
+	"github.com/ooni/probe-cli/v3/internal/engine/experiment/webconnectivity"
+	"github.com/ooni/probe-cli/v3/internal/model"
+	"golang.org/x/net/publicsuffix"
+)
+
+// Measurer for the web_connectivity experiment.
+type Measurer struct {
+	// Contains the experiment's config.
+	Config *Config
+}
+
+// NewExperimentMeasurer creates a new model.ExperimentMeasurer.
+func NewExperimentMeasurer(config *Config) model.ExperimentMeasurer {
+	return &Measurer{
+		Config: config,
+	}
+}
+
+// ExperimentName implements model.ExperimentMeasurer.
+func (m *Measurer) ExperimentName() string {
+	return "web_connectivity"
+}
+
+// ExperimentVersion implements model.ExperimentMeasurer.
+func (m *Measurer) ExperimentVersion() string {
+	return "0.5.0"
+}
+
+// Run implements model.ExperimentMeasurer.
+func (m *Measurer) Run(ctx context.Context, sess model.ExperimentSession,
+	measurement *model.Measurement, callbacks model.ExperimentCallbacks) error {
+	// Reminder: when this function returns an error, the measurement result
+	// WILL NOT be submitted to the OONI backend. You SHOULD only return an error
+	// for fundamental errors (e.g., the input is invalid or missing).
+
+	// honour InputOrQueryBackend
+	input := measurement.Input
+	if input == "" {
+		return errors.New("no input provided")
+	}
+
+	// convert the input string to a URL
+	inputParser := &InputParser{
+		AcceptedSchemes: []string{
+			"http",
+			"https",
+		},
+		AllowEndpoints: false,
+		DefaultScheme:  "",
+	}
+	URL, err := inputParser.Parse(string(measurement.Input))
+	if err != nil {
+		return err
+	}
+
+	// initialize the experiment's test keys
+	tk := NewTestKeys()
+	measurement.TestKeys = tk
+
+	// create variables required to run parallel tasks
+	idGenerator := &atomicx.Int64{}
+	wg := &sync.WaitGroup{}
+
+	// create cookiejar
+	jar, err := cookiejar.New(&cookiejar.Options{
+		PublicSuffixList: publicsuffix.List,
+	})
+	if err != nil {
+		return err
+	}
+
+	// obtain the test helper's address
+	testhelpers, _ := sess.GetTestHelpersByName("web-connectivity")
+	var thAddr string
+	for _, th := range testhelpers {
+		if th.Type == "https" {
+			thAddr = th.Address
+			measurement.TestHelpers = map[string]any{
+				"backend": &th,
+			}
+			break
+		}
+	}
+	if thAddr == "" {
+		sess.Logger().Warnf("continuing without a valid TH address")
+		tk.SetControlFailure(webconnectivity.ErrNoAvailableTestHelpers)
+	}
+
+	// start background tasks
+	resos := &DNSResolvers{
+		DNSCache:    NewDNSCache(),
+		Domain:      URL.Hostname(),
+		IDGenerator: idGenerator,
+		Logger:      sess.Logger(),
+		TestKeys:    tk,
+		URL:         URL,
+		ZeroTime:    measurement.MeasurementStartTimeSaved,
+		WaitGroup:   wg,
+		CookieJar:   jar,
+		Referer:     "",
+		Session:     sess,
+		THAddr:      thAddr,
+		UDPAddress:  "",
+	}
+	resos.Start(ctx)
+
+	// wait for background tasks to join
+	wg.Wait()
+
+	// If the context passed to us has been cancelled, we cannot
+	// trust this experiment's results to be okay.
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+
+	// perform any deferred computation on the test keys
+	tk.Finalize(sess.Logger())
+
+	// return whether there was a fundamental failure, which would prevent
+	// the measurement from being submitted to the OONI collector.
+	return tk.fundamentalFailure
+}