func()

in pkg/tc/tc.go [179:229]

• 43 lines of code
• 6 McCabe index (conditional complexity)

func (m *bpfTc) TCEgressAttach(interfaceName string, progFD int, funcName string) error {

	if err := mismatchedInterfacePrefix(interfaceName, m.InterfacePrefix); err != nil {
		return err
	}

	intf, err := netlink.LinkByName(interfaceName)
	if err != nil {
		log.Errorf("failed to find device by name %s: %w", interfaceName, err)
		return err
	}

	attrs := netlink.QdiscAttrs{
		LinkIndex: intf.Attrs().Index,
		Handle:    netlink.MakeHandle(constdef.QDISC_HANDLE, 0),
		Parent:    netlink.HANDLE_CLSACT,
	}

	if enableQdisc(intf) {
		qdisc := &netlink.GenericQdisc{
			QdiscAttrs: attrs,
			QdiscType:  "clsact",
		}

		if err := netlink.QdiscAdd(qdisc); err != nil {
			log.Errorf("cannot add clsact qdisc: %v", err)
			return err
		}
	}

	// construct the filter
	filter := &netlink.BpfFilter{
		FilterAttrs: netlink.FilterAttrs{
			LinkIndex: attrs.LinkIndex,
			Parent:    uint32(netlink.HANDLE_MIN_EGRESS),
			Handle:    constdef.DEFAULT_BPF_FILTER_HANDLE,
			Protocol:  unix.ETH_P_ALL,
			Priority:  1,
		},
		Fd:           progFD,
		Name:         funcName,
		DirectAction: true,
	}

	if err = netlink.FilterAdd(filter); err != nil {
		log.Errorf("while loading egress program %q on fd %d: %v", "handle egress", progFD, err)
		return err
	}
	log.Infof("TC filter egress add done %s", interfaceName)
	return nil
}