dns-conf.go

func buildBlockedIPs(client network.Client, blockMalicious, blockAds, blockSurveillance bool,
	privateAddresses []string) (lines []string, errs []error) {
	chResults := make(chan []string)
	chError := make(chan error)
	listsLeftToFetch := 0
	if blockMalicious {
		listsLeftToFetch++
		go func() {
			results, err := getList(client, string(constants.MaliciousBlockListIPsURL))
			chResults <- results
			chError <- err
		}()
	}
	if blockAds {
		listsLeftToFetch++
		go func() {
			results, err := getList(client, string(constants.AdsBlockListIPsURL))
			chResults <- results
			chError <- err
		}()
	}
	if blockSurveillance {
		listsLeftToFetch++
		go func() {
			results, err := getList(client, string(constants.SurveillanceBlockListIPsURL))
			chResults <- results
			chError <- err
		}()
	}
	uniqueResults := make(map[string]struct{})
	for listsLeftToFetch > 0 {
		select {
		case results := <-chResults:
			for _, result := range results {
				uniqueResults[result] = struct{}{}
			}
		case err := <-chError:
			listsLeftToFetch--
			if err != nil {
				errs = append(errs, err)
			}
		}
	}
	for _, privateAddress := range privateAddresses {
		uniqueResults[privateAddress] = struct{}{}
	}
	for result := range uniqueResults {
		lines = append(lines, "  private-address: "+result)
	}
	return lines, errs
}