Fix NewHtbClass

- Prio and Quantum should be set equal to the input params
- Fix buffer and cbuffer due to incorrect hz
- Fix Xmittime which is also not equal the behavior of c library.
C library converts time to uint32 to drop precision before multiply
tick_in_usec. ref https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/tc/tc_core.c#n62

Author: chenchun

class_linux.go

@@ -43,22 +43,22 @@ func NewHtbClass(attrs ClassAttrs, cattrs HtbClassAttrs) *HtbClass {
 	if buffer == 0 {
 		buffer = uint32(float64(rate)/Hz() + float64(mtu))
 	}
-	buffer = uint32(Xmittime(rate, buffer))
+	buffer = Xmittime(rate, buffer)
 
 	if cbuffer == 0 {
 		cbuffer = uint32(float64(ceil)/Hz() + float64(mtu))
 	}
-	cbuffer = uint32(Xmittime(ceil, cbuffer))
+	cbuffer = Xmittime(ceil, cbuffer)
 
 	return &HtbClass{
 		ClassAttrs: attrs,
 		Rate:       rate,
 		Ceil:       ceil,
 		Buffer:     buffer,
 		Cbuffer:    cbuffer,
-		Quantum:    10,
 		Level:      0,
-		Prio:       0,
+		Prio:       cattrs.Prio,
+		Quantum:    cattrs.Quantum,
 	}
 }
 

class_test.go

@@ -97,6 +97,8 @@ func TestClassAddDel(t *testing.T) {
 	htbclassattrs := HtbClassAttrs{
 		Rate:    1234000,
 		Cbuffer: 1690,
+		Prio:    2,
+		Quantum: 1000,
 	}
 	class := NewHtbClass(classattrs, htbclassattrs)
 	if err := ClassAdd(class); err != nil {
@@ -126,6 +128,12 @@ func TestClassAddDel(t *testing.T) {
 	if htb.Cbuffer != class.Cbuffer {
 		t.Fatal("Cbuffer doesn't match")
 	}
+	if htb.Prio != class.Prio {
+		t.Fatal("Prio doesn't match")
+	}
+	if htb.Quantum != class.Quantum {
+		t.Fatal("Quantum doesn't match")
+	}
 
 	testClassStats(htb.ClassAttrs.Statistics, NewClassStatistics(), t)
 

filter_linux.go

@@ -89,7 +89,7 @@ func NewFw(attrs FilterAttrs, fattrs FilterFwAttrs) (*Fw, error) {
 		if CalcRtable(&police.Rate, rtab[:], rcellLog, fattrs.Mtu, linklayer) < 0 {
 			return nil, errors.New("TBF: failed to calculate rate table")
 		}
-		police.Burst = uint32(Xmittime(uint64(police.Rate.Rate), uint32(buffer)))
+		police.Burst = Xmittime(uint64(police.Rate.Rate), uint32(buffer))
 	}
 	police.Mtu = fattrs.Mtu
 	if police.PeakRate.Rate != 0 {
@@ -783,7 +783,7 @@ func CalcRtable(rate *nl.TcRateSpec, rtab []uint32, cellLog int, mtu uint32, lin
 	}
 	for i := 0; i < 256; i++ {
 		sz = AdjustSize(uint((i+1)<<uint32(cellLog)), uint(mpu), linklayer)
-		rtab[i] = uint32(Xmittime(uint64(bps), uint32(sz)))
+		rtab[i] = Xmittime(uint64(bps), uint32(sz))
 	}
 	rate.CellAlign = -1
 	rate.CellLog = uint8(cellLog)

qdisc_linux.go

@@ -598,10 +598,10 @@ func initClock() {
 		return
 	}
 	parts := strings.Split(strings.TrimSpace(string(data)), " ")
-	if len(parts) < 3 {
+	if len(parts) < 4 {
 		return
 	}
-	var vals [3]uint64
+	var vals [4]uint64
 	for i := range vals {
 		val, err := strconv.ParseUint(parts[i], 16, 32)
 		if err != nil {
@@ -615,7 +615,12 @@ func initClock() {
 	}
 	clockFactor = float64(vals[2]) / TIME_UNITS_PER_SEC
 	tickInUsec = float64(vals[0]) / float64(vals[1]) * clockFactor
-	hz = float64(vals[0])
+	if vals[2] == 1000000 {
+		// ref https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/lib/utils.c#n963
+		hz = float64(vals[3])
+	} else {
+		hz = 100
+	}
 }
 
 func TickInUsec() float64 {
@@ -663,6 +668,7 @@ func latency(rate uint64, limit, buffer uint32) float64 {
 	return TIME_UNITS_PER_SEC*(float64(limit)/float64(rate)) - float64(tick2Time(buffer))
 }
 
-func Xmittime(rate uint64, size uint32) float64 {
-	return TickInUsec() * TIME_UNITS_PER_SEC * (float64(size) / float64(rate))
+func Xmittime(rate uint64, size uint32) uint32 {
+	// https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/tc/tc_core.c#n62
+	return time2Tick(uint32(TIME_UNITS_PER_SEC * (float64(size) / float64(rate))))
 }