bandwidth: use regexp to handle tc output and add IPv6 support

pkg/util/bandwidth/linux.go

@@ -24,6 +24,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"net"
+	"regexp"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -33,6 +34,11 @@ import (
 	"k8s.io/klog"
 )
 
+var (
+	classShowMatcher      = regexp.MustCompile(`class htb (1:\d+)`)
+	classAndHandleMatcher = regexp.MustCompile(`filter parent 1:.*fh (\d+::\d+).*flowid (\d+:\d+)`)
+)
+
 // tcShaper provides an implementation of the Shaper interface on Linux using the 'tc' tool.
 // In general, using this requires that the caller posses the NET_CAP_ADMIN capability, though if you
 // do this within an container, it only requires the NS_CAPABLE capability for manipulations to that
@@ -75,13 +81,13 @@ func (t *tcShaper) nextClassID() (int, error) {
 		if len(line) == 0 {
 			continue
 		}
-		parts := strings.Split(line, " ")
 		// expected tc line:
 		// class htb 1:1 root prio 0 rate 1000Kbit ceil 1000Kbit burst 1600b cburst 1600b
-		if len(parts) != 14 {
-			return -1, fmt.Errorf("unexpected output from tc: %s (%v)", scanner.Text(), parts)
+		matches := classShowMatcher.FindStringSubmatch(line)
+		if len(matches) != 2 {
+			return -1, fmt.Errorf("unexpected output from tc: %s (%v)", scanner.Text(), matches)
 		}
-		classes.Insert(parts[2])
+		classes.Insert(matches[1])
 	}
 
 	// Make sure it doesn't go forever
@@ -153,13 +159,14 @@ func (t *tcShaper) findCIDRClass(cidr string) (classAndHandleList [][]string, fo
 			continue
 		}
 		if strings.Contains(line, spec) {
-			parts := strings.Split(filter, " ")
 			// expected tc line:
-			// filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1
-			if len(parts) != 19 {
-				return classAndHandleList, false, fmt.Errorf("unexpected output from tc: %s %d (%v)", filter, len(parts), parts)
+			// `filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1` (old version) or
+			// `filter parent 1: protocol ip pref 1 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 not_in_hw` (new version)
+			matches := classAndHandleMatcher.FindStringSubmatch(filter)
+			if len(matches) != 3 {
+				return classAndHandleList, false, fmt.Errorf("unexpected output from tc: %s %d (%v)", filter, len(matches), matches)
 			}
-			resultTmp := []string{parts[18], parts[9]}
+			resultTmp := []string{matches[2], matches[1]}
 			classAndHandleList = append(classAndHandleList, resultTmp)
 		}
 	}
@@ -301,7 +308,6 @@ func (t *tcShaper) Reset(cidr string) error {
 		}
 	}
 	return nil
-
 }
 
 func (t *tcShaper) deleteInterface(class string) error {

pkg/util/bandwidth/linux_test.go

@@ -212,6 +212,13 @@ filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0
 filter parent 1: protocol ip pref 1 u32 fh 800::801 order 2049 key ht 800 bkt 0 flowid 1:2 
   match 01020000/ffff0000 at 16
 `
+var tcFilterOutputNewVersion = `filter parent 1: protocol ip pref 1 u32
+filter parent 1: protocol ip pref 1 u32 chain 0 fh 800: ht divisor 1
+filter parent 1: protocol ip pref 1 u32 chain 0 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 not_in_hw
+  match ac110002/ffffffff at 16
+filter parent 1: protocol ip pref 1 u32 chain 0 fh 800::801 order 2049 key ht 800 bkt 0 flowid 1:2 not_in_hw
+  match 01020000/ffff0000 at 16
+`
 
 func TestFindCIDRClass(t *testing.T) {
 	tests := []struct {
@@ -240,6 +247,23 @@ func TestFindCIDRClass(t *testing.T) {
 			output:         tcFilterOutput,
 			expectNotFound: true,
 		},
+		{
+			cidr:           "172.17.0.2/32",
+			output:         tcFilterOutputNewVersion,
+			expectedClass:  "1:1",
+			expectedHandle: "800::800",
+		},
+		{
+			cidr:           "1.2.3.4/16",
+			output:         tcFilterOutputNewVersion,
+			expectedClass:  "1:2",
+			expectedHandle: "800::801",
+		},
+		{
+			cidr:           "2.2.3.4/16",
+			output:         tcFilterOutputNewVersion,
+			expectNotFound: true,
+		},
 		{
 			err:       errors.New("test error"),
 			expectErr: true,