tbf.go

package main

import (
	"fmt"
	"log"
	"time"

	"github.com/vishvananda/netlink"
)

func main() {
	l, err := netlink.LinkByName("lo")
	if err != nil {
		panic(err)
	}
	log.Println("Qdisc test start")
	for {
		var bw uint64
		fmt.Scan(&bw)
		bandwidth := bw // Kbits
		rate := uint64(bandwidth) * 1000 / 8
		buffer := uint32(bandwidth * 1000 / 250)
		if buffer < 32000 {
			buffer = uint32(32000)
		}
		limit := uint32(rate/10) + buffer
		log.Printf("rate: %d\n", rate)
		log.Printf("burst: %d\n", buffer)
		log.Printf("buffer: %d\n", buffer*1000/8)
		log.Printf("limit: %d\n", limit)
		tbf := &netlink.Tbf{
			QdiscAttrs: netlink.QdiscAttrs{
				LinkIndex: l.Attrs().Index,
				Handle:    netlink.MakeHandle(1, 0),
				Parent:    netlink.HANDLE_ROOT,
			},
			Rate:     rate,
			Limit:    limit,
			Buffer:   buffer * 1000 / 8, // buffer uint is millibyte...
			Minburst: 1540,
		}
		err = netlink.QdiscAdd(tbf)
		if err != nil {
			log.Fatalf("QdiskAdd error: %s\n", err)
		}
		qdiscs, _ := netlink.QdiscList(l)
		log.Println("Qdisk set done")
		log.Printf("%#v\n", qdiscs[0])
		time.Sleep(10 * time.Second)
		err = netlink.QdiscDel(tbf)
		if err != nil {
			log.Fatalf("QdiskDel error: %s", err)
		}
		log.Println("Qdisc delete done")
	}
	log.Println("Qdisc test end")
}