refactor(oohelperd): better distinguish different helpers (#434)

Part of https://github.com/ooni/probe/issues/1733

internal/cmd/oohelperd/internal/http.go

@@ -1,65 +0,0 @@
-package internal
-
-import (
-	"context"
-	"io"
-	"net/http"
-	"strings"
-	"sync"
-
-	"github.com/ooni/probe-cli/v3/internal/engine/experiment/webconnectivity"
-	"github.com/ooni/probe-cli/v3/internal/iox"
-)
-
-// CtrlHTTPResponse is the result of the HTTP check performed by
-// the Web Connectivity test helper.
-type CtrlHTTPResponse = webconnectivity.ControlHTTPRequestResult
-
-// HTTPConfig configures the HTTP check.
-type HTTPConfig struct {
-	Client            *http.Client
-	Headers           map[string][]string
-	MaxAcceptableBody int64
-	Out               chan CtrlHTTPResponse
-	URL               string
-	Wg                *sync.WaitGroup
-}
-
-// HTTPDo performs the HTTP check.
-func HTTPDo(ctx context.Context, config *HTTPConfig) {
-	defer config.Wg.Done()
-	req, err := http.NewRequestWithContext(ctx, "GET", config.URL, nil)
-	if err != nil {
-		config.Out <- CtrlHTTPResponse{Failure: newfailure(err)}
-		return
-	}
-	// The original test helper failed with extra headers while here
-	// we're implementing (for now?) a more liberal approach.
-	for k, vs := range config.Headers {
-		switch strings.ToLower(k) {
-		case "user-agent", "accept", "accept-language":
-			for _, v := range vs {
-				req.Header.Add(k, v)
-			}
-		}
-	}
-	resp, err := config.Client.Do(req)
-	if err != nil {
-		config.Out <- CtrlHTTPResponse{Failure: newfailure(err)}
-		return
-	}
-	defer resp.Body.Close()
-	headers := make(map[string]string)
-	for k := range resp.Header {
-		headers[k] = resp.Header.Get(k)
-	}
-	reader := &io.LimitedReader{R: resp.Body, N: config.MaxAcceptableBody}
-	data, err := iox.ReadAllContext(ctx, reader)
-	config.Out <- CtrlHTTPResponse{
-		BodyLength: int64(len(data)),
-		Failure:    newfailure(err),
-		StatusCode: int64(resp.StatusCode),
-		Headers:    headers,
-		Title:      webconnectivity.GetTitle(string(data)),
-	}
-}