mtg/faketls/cloak.go

package faketls

import (
	"context"
	"io"
	"sync"
	"time"

	"github.com/9seconds/mtg/wrappers/rwc"
)

const cloakTimeout = 5 * time.Second

func cloak(one, another io.ReadWriteCloser) {
	defer func() {
		one.Close()
		another.Close()
	}()

	channelPing := make(chan struct{}, 1)
	ctx, cancel := context.WithCancel(context.Background())
	one = rwc.NewPing(ctx, one, channelPing)
	another = rwc.NewPing(ctx, another, channelPing)
	wg := &sync.WaitGroup{}

	wg.Add(2)

	go func() {
		defer wg.Done()
		io.Copy(one, another) // nolint: errcheck
	}()

	go func() {
		defer wg.Done()
		io.Copy(another, one) // nolint: errcheck
	}()

	go func() {
		wg.Wait()
		cancel()
	}()

	go func() {
		timer := time.NewTimer(cloakTimeout)
		defer timer.Stop()

		for {
			select {
			case <-channelPing:
				timer.Stop()
				timer = time.NewTimer(cloakTimeout)
			case <-ctx.Done():
				return
			case <-timer.C:
				cancel()
				return
			}
		}
	}()

	<-ctx.Done()
}