change tc instead of replacing it

main.go

@@ -12,7 +12,6 @@ import (
 	"os/signal"
 	"regexp"
 	"strconv"
-	"strings"
 	"syscall"
 	"time"
 )
@@ -29,7 +28,6 @@ type Conf struct {
 	ConformationPPP       int    `yaml:"conformation_ppp"`
 	LogLevel              string `yaml:"log_level"`
 	UploadInterface       string `yaml:"upload_interface"`
-	CakeOptions           string `yaml:"cake_options"`
 	ThrottlePingThreshold int64  `yaml:"throttle_ping_threshold"`
 	TryRestoringAfter     int    `yaml:"try_restoring_after"`
 }
@@ -62,10 +60,7 @@ func (m UploadManager) Upload() (int, error) {
 }
 
 func (m UploadManager) SetUpload(upload int) (int, error) {
-	m.clearTC()
-	args := []string{"qdisc", "add", "dev", conf.UploadInterface, "root", "cake", "bandwidth", fmt.Sprintf("%dMbit", upload)}
-	args = append(args, strings.Split(conf.CakeOptions, " ")...)
-	tcCmd := exec.Command("tc", args...)
+	tcCmd := exec.Command("tc", "qdisc", "change", "dev", conf.UploadInterface, "root", "cake", "bandwidth", fmt.Sprintf("%dMbit", upload))
 	log.Debugf("[TC] exec %s", tcCmd.String())
 	out, err := tcCmd.CombinedOutput()
 	if err != nil {
@@ -75,15 +70,6 @@ func (m UploadManager) SetUpload(upload int) (int, error) {
 	return upload, nil
 }
 
-func (m UploadManager) clearTC() {
-	tcCmd := exec.Command("tc", "qdisc", "del", "dev", conf.UploadInterface, "root")
-	log.Debugf("[TC] exec %s", tcCmd.String())
-	out, err := tcCmd.CombinedOutput()
-	if err != nil {
-		log.Debugf("[TC] executing %s failed with: %v (%s)", tcCmd.String(), err, out)
-	}
-}
-
 func doPing(host string, count int, interval time.Duration) (*ping.Statistics, error) {
 	log.Debugf("[PING] starting to ping %s with %d packages", host, count)
 	pinger, err := ping.NewPinger(host)