feat: add LinkSetBondSlaveActive()/LinkDelBondSlave()

Signed-off-by: Jason Joo <hblzxsj@gmail.com>

link_linux.go

@@ -3704,8 +3704,7 @@ func parseXfrmiData(link Link, data []syscall.NetlinkRouteAttr) {
 	}
 }
 
-// LinkSetBondSlave add slave to bond link via ioctl interface.
-func LinkSetBondSlave(link Link, master *Bond) error {
+func ioctlBondSlave(cmd uintptr, link Link, master *Bond) error {
 	fd, err := getSocketUDP()
 	if err != nil {
 		return err
@@ -3713,10 +3712,38 @@ func LinkSetBondSlave(link Link, master *Bond) error {
 	defer syscall.Close(fd)
 
 	ifreq := newIocltSlaveReq(link.Attrs().Name, master.Attrs().Name)
-
-	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), unix.SIOCBONDENSLAVE, uintptr(unsafe.Pointer(ifreq)))
+	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), cmd, uintptr(unsafe.Pointer(ifreq)))
 	if errno != 0 {
-		return fmt.Errorf("Failed to enslave %q to %q, errno=%v", link.Attrs().Name, master.Attrs().Name, errno)
+		return fmt.Errorf("errno=%v", errno)
+	}
+	return nil
+}
+
+// LinkSetBondSlaveActive sets specified slave to ACTIVE in an `active-backup` bond link via ioctl interface.
+//
+//	Multiple calls keeps the status unchanged(shown in the unit test).
+func LinkSetBondSlaveActive(link Link, master *Bond) error {
+	err := ioctlBondSlave(unix.SIOCBONDCHANGEACTIVE, link, master)
+	if err != nil {
+		return fmt.Errorf("Failed to set slave %q active in %q, %v", link.Attrs().Name, master.Attrs().Name, err)
+	}
+	return nil
+}
+
+// LinkSetBondSlave add slave to bond link via ioctl interface.
+func LinkSetBondSlave(link Link, master *Bond) error {
+	err := ioctlBondSlave(unix.SIOCBONDENSLAVE, link, master)
+	if err != nil {
+		return fmt.Errorf("Failed to enslave %q to %q, %v", link.Attrs().Name, master.Attrs().Name, err)
+	}
+	return nil
+}
+
+// LinkSetBondSlave removes specified slave from bond link via ioctl interface.
+func LinkDelBondSlave(link Link, master *Bond) error {
+	err := ioctlBondSlave(unix.SIOCBONDRELEASE, link, master)
+	if err != nil {
+		return fmt.Errorf("Failed to del slave %q from %q, %v", link.Attrs().Name, master.Attrs().Name, err)
 	}
 	return nil
 }

link_test.go

@@ -3205,6 +3205,108 @@ func TestLinkSetBondSlave(t *testing.T) {
 	}
 }
 
+func testFailover(t *testing.T, slaveName, bondName string) {
+	slaveLink, err := LinkByName(slaveName)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	bondLink, err := LinkByName(bondName)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = LinkSetBondSlaveActive(slaveLink, &Bond{LinkAttrs: *bondLink.Attrs()})
+	if err != nil {
+		t.Errorf("set slave link active failed: %v", err)
+		return
+	}
+
+	bondLink, err = LinkByName(bondName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bond := bondLink.(*Bond)
+	if bond.ActiveSlave != slaveLink.Attrs().Index {
+		t.Errorf("the current active slave %d is not expected as %d", bond.ActiveSlave, slaveLink.Attrs().Index)
+	}
+}
+
+func TestLinkFailover(t *testing.T) {
+	minKernelRequired(t, 3, 13)
+
+	tearDown := setUpNetlinkTest(t)
+	defer tearDown()
+
+	const (
+		bondName     = "foo"
+		slaveOneName = "fooFoo"
+		slaveTwoName = "fooBar"
+	)
+
+	bond := NewLinkBond(LinkAttrs{Name: bondName})
+	bond.Mode = StringToBondModeMap["active-backup"]
+	bond.Miimon = 100
+
+	if err := LinkAdd(bond); err != nil {
+		t.Fatal(err)
+	}
+
+	bondLink, err := LinkByName(bondName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer LinkDel(bondLink)
+
+	if err := LinkAdd(&Dummy{LinkAttrs{Name: slaveOneName}}); err != nil {
+		t.Fatal(err)
+	}
+
+	slaveOneLink, err := LinkByName(slaveOneName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer LinkDel(slaveOneLink)
+
+	if err := LinkAdd(&Dummy{LinkAttrs{Name: slaveTwoName}}); err != nil {
+		t.Fatal(err)
+	}
+	slaveTwoLink, err := LinkByName(slaveTwoName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer LinkDel(slaveTwoLink)
+
+	if err := LinkSetBondSlave(slaveOneLink, &Bond{LinkAttrs: *bondLink.Attrs()}); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := LinkSetBondSlave(slaveTwoLink, &Bond{LinkAttrs: *bondLink.Attrs()}); err != nil {
+		t.Fatal(err)
+	}
+
+	testFailover(t, slaveOneName, bondName)
+	testFailover(t, slaveTwoName, bondName)
+	testFailover(t, slaveTwoName, bondName)
+
+	// del slave from bond
+	slaveOneLink, err = LinkByName(slaveOneName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = LinkDelBondSlave(slaveOneLink, &Bond{LinkAttrs: *bondLink.Attrs()})
+	if err != nil {
+		t.Errorf("Remove slave %s from bond failed: %v", slaveOneName, err)
+	}
+	slaveOneLink, err = LinkByName(slaveOneName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if slaveOneLink.Attrs().MasterIndex > 0 {
+		t.Errorf("The nic %s is still a slave of %d", slaveOneName, slaveOneLink.Attrs().MasterIndex)
+	}
+}
+
 func TestLinkSetAllmulticast(t *testing.T) {
 	tearDown := setUpNetlinkTest(t)
 	defer tearDown()