func classPayload(req *nl.NetlinkRequest, class Class) error { req.AddData(nl.NewRtAttr(nl.TCA_KIND, nl.ZeroTerminated(class.Type()))) options := nl.NewRtAttr(nl.TCA_OPTIONS, nil) if htb, ok := class.(*HtbClass); ok { opt := nl.TcHtbCopt{} opt.Buffer = htb.Buffer opt.Cbuffer = htb.Cbuffer opt.Quantum = htb.Quantum opt.Level = htb.Level opt.Prio = htb.Prio // TODO: Handle Debug properly. For now default to 0 /* Calculate {R,C}Tab and set Rate and Ceil */ cell_log := -1 ccell_log := -1 linklayer := nl.LINKLAYER_ETHERNET mtu := 1600 var rtab [256]uint32 var ctab [256]uint32 tcrate := nl.TcRateSpec{Rate: uint32(htb.Rate)} if CalcRtable(&tcrate, rtab, cell_log, uint32(mtu), linklayer) < 0 { return errors.New("HTB: failed to calculate rate table.") } opt.Rate = tcrate tcceil := nl.TcRateSpec{Rate: uint32(htb.Ceil)} if CalcRtable(&tcceil, ctab, ccell_log, uint32(mtu), linklayer) < 0 { return errors.New("HTB: failed to calculate ceil rate table.") } opt.Ceil = tcceil nl.NewRtAttrChild(options, nl.TCA_HTB_PARMS, opt.Serialize()) nl.NewRtAttrChild(options, nl.TCA_HTB_RTAB, SerializeRtab(rtab)) nl.NewRtAttrChild(options, nl.TCA_HTB_CTAB, SerializeRtab(ctab)) } req.AddData(options) return nil }
func setProtinfoAttr(link Link, mode bool, attr int) error { base := link.Attrs() ensureIndex(base) req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK) msg := nl.NewIfInfomsg(syscall.AF_BRIDGE) msg.Index = int32(base.Index) req.AddData(msg) br := nl.NewRtAttr(syscall.IFLA_PROTINFO|syscall.NLA_F_NESTED, nil) nl.NewRtAttrChild(br, attr, boolToByte(mode)) req.AddData(br) _, err := req.Execute(syscall.NETLINK_ROUTE, 0) if err != nil { return err } return nil }
func qdiscPayload(req *nl.NetlinkRequest, qdisc Qdisc) error { req.AddData(nl.NewRtAttr(nl.TCA_KIND, nl.ZeroTerminated(qdisc.Type()))) options := nl.NewRtAttr(nl.TCA_OPTIONS, nil) if prio, ok := qdisc.(*Prio); ok { tcmap := nl.TcPrioMap{ Bands: int32(prio.Bands), Priomap: prio.PriorityMap, } options = nl.NewRtAttr(nl.TCA_OPTIONS, tcmap.Serialize()) } else if tbf, ok := qdisc.(*Tbf); ok { opt := nl.TcTbfQopt{} // TODO: handle rate > uint32 opt.Rate.Rate = uint32(tbf.Rate) opt.Limit = tbf.Limit opt.Buffer = tbf.Buffer nl.NewRtAttrChild(options, nl.TCA_TBF_PARMS, opt.Serialize()) } else if htb, ok := qdisc.(*Htb); ok { opt := nl.TcHtbGlob{} opt.Version = htb.Version opt.Rate2Quantum = htb.Rate2Quantum opt.Defcls = htb.Defcls // TODO: Handle Debug properly. For now default to 0 opt.Debug = htb.Debug opt.DirectPkts = htb.DirectPkts nl.NewRtAttrChild(options, nl.TCA_HTB_INIT, opt.Serialize()) // nl.NewRtAttrChild(options, nl.TCA_HTB_DIRECT_QLEN, opt.Serialize()) } else if netem, ok := qdisc.(*Netem); ok { opt := nl.TcNetemQopt{} opt.Latency = netem.Latency opt.Limit = netem.Limit opt.Loss = netem.Loss opt.Gap = netem.Gap opt.Duplicate = netem.Duplicate opt.Jitter = netem.Jitter options = nl.NewRtAttr(nl.TCA_OPTIONS, opt.Serialize()) // Correlation corr := nl.TcNetemCorr{} corr.DelayCorr = netem.DelayCorr corr.LossCorr = netem.LossCorr corr.DupCorr = netem.DuplicateCorr if corr.DelayCorr > 0 || corr.LossCorr > 0 || corr.DupCorr > 0 { nl.NewRtAttrChild(options, nl.TCA_NETEM_CORR, corr.Serialize()) } // Corruption corruption := nl.TcNetemCorrupt{} corruption.Probability = netem.CorruptProb corruption.Correlation = netem.CorruptCorr if corruption.Probability > 0 { nl.NewRtAttrChild(options, nl.TCA_NETEM_CORRUPT, corruption.Serialize()) } // Reorder reorder := nl.TcNetemReorder{} reorder.Probability = netem.ReorderProb reorder.Correlation = netem.ReorderCorr if reorder.Probability > 0 { nl.NewRtAttrChild(options, nl.TCA_NETEM_REORDER, reorder.Serialize()) } } else if _, ok := qdisc.(*Ingress); ok { // ingress filters must use the proper handle if qdisc.Attrs().Parent != HANDLE_INGRESS { return fmt.Errorf("Ingress filters must set Parent to HANDLE_INGRESS") } } req.AddData(options) return nil }
// FilterAdd will add a filter to the system. // Equivalent to: `tc filter add $filter` func FilterAdd(filter Filter) error { native = nl.NativeEndian() req := nl.NewNetlinkRequest(syscall.RTM_NEWTFILTER, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK) base := filter.Attrs() msg := &nl.TcMsg{ Family: nl.FAMILY_ALL, Ifindex: int32(base.LinkIndex), Handle: base.Handle, Parent: base.Parent, Info: MakeHandle(base.Priority, nl.Swap16(base.Protocol)), } req.AddData(msg) req.AddData(nl.NewRtAttr(nl.TCA_KIND, nl.ZeroTerminated(filter.Type()))) options := nl.NewRtAttr(nl.TCA_OPTIONS, nil) if u32, ok := filter.(*U32); ok { // match all sel := nl.TcU32Sel{ Nkeys: 1, Flags: nl.TC_U32_TERMINAL, } sel.Keys = append(sel.Keys, nl.TcU32Key{}) nl.NewRtAttrChild(options, nl.TCA_U32_SEL, sel.Serialize()) actions := nl.NewRtAttrChild(options, nl.TCA_U32_ACT, nil) table := nl.NewRtAttrChild(actions, nl.TCA_ACT_TAB, nil) nl.NewRtAttrChild(table, nl.TCA_KIND, nl.ZeroTerminated("mirred")) // redirect to other interface mir := nl.TcMirred{ Action: nl.TC_ACT_STOLEN, Eaction: nl.TCA_EGRESS_REDIR, Ifindex: uint32(u32.RedirIndex), } aopts := nl.NewRtAttrChild(table, nl.TCA_OPTIONS, nil) nl.NewRtAttrChild(aopts, nl.TCA_MIRRED_PARMS, mir.Serialize()) } else if fw, ok := filter.(*Fw); ok { if fw.Mask != 0 { b := make([]byte, 4) native.PutUint32(b, fw.Mask) nl.NewRtAttrChild(options, nl.TCA_FW_MASK, b) } if fw.InDev != "" { nl.NewRtAttrChild(options, nl.TCA_FW_INDEV, nl.ZeroTerminated(fw.InDev)) } if (fw.Police != nl.TcPolice{}) { police := nl.NewRtAttrChild(options, nl.TCA_FW_POLICE, nil) nl.NewRtAttrChild(police, nl.TCA_POLICE_TBF, fw.Police.Serialize()) if (fw.Police.Rate != nl.TcRateSpec{}) { payload := SerializeRtab(fw.Rtab) nl.NewRtAttrChild(police, nl.TCA_POLICE_RATE, payload) } if (fw.Police.PeakRate != nl.TcRateSpec{}) { payload := SerializeRtab(fw.Ptab) nl.NewRtAttrChild(police, nl.TCA_POLICE_PEAKRATE, payload) } } if fw.ClassId != 0 { b := make([]byte, 4) native.PutUint32(b, fw.ClassId) nl.NewRtAttrChild(options, nl.TCA_FW_CLASSID, b) } } req.AddData(options) _, err := req.Execute(syscall.NETLINK_ROUTE, 0) return err }
// LinkAdd adds a new link device. The type and features of the device // are taken fromt the parameters in the link object. // Equivalent to: `ip link add $link` func LinkAdd(link Link) error { // TODO: set mtu and hardware address // TODO: support extra data for macvlan base := link.Attrs() if base.Name == "" { return fmt.Errorf("LinkAttrs.Name cannot be empty!") } if tuntap, ok := link.(*Tuntap); ok { // TODO: support user // TODO: support group // TODO: support non- one_queue // TODO: support pi | vnet_hdr | multi_queue // TODO: support non- exclusive // TODO: support non- persistent if tuntap.Mode < syscall.IFF_TUN || tuntap.Mode > syscall.IFF_TAP { return fmt.Errorf("Tuntap.Mode %v unknown!", tuntap.Mode) } file, err := os.OpenFile("/dev/net/tun", os.O_RDWR, 0) if err != nil { return err } defer file.Close() var req ifReq req.Flags |= syscall.IFF_ONE_QUEUE req.Flags |= syscall.IFF_TUN_EXCL copy(req.Name[:15], base.Name) req.Flags |= uint16(tuntap.Mode) _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, file.Fd(), uintptr(syscall.TUNSETIFF), uintptr(unsafe.Pointer(&req))) if errno != 0 { return fmt.Errorf("Tuntap IOCTL TUNSETIFF failed, errno %v", errno) } _, _, errno = syscall.Syscall(syscall.SYS_IOCTL, file.Fd(), uintptr(syscall.TUNSETPERSIST), 1) if errno != 0 { return fmt.Errorf("Tuntap IOCTL TUNSETPERSIST failed, errno %v", errno) } ensureIndex(base) // can't set master during create, so set it afterwards if base.MasterIndex != 0 { // TODO: verify MasterIndex is actually a bridge? return LinkSetMasterByIndex(link, base.MasterIndex) } return nil } req := nl.NewNetlinkRequest(syscall.RTM_NEWLINK, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK) msg := nl.NewIfInfomsg(syscall.AF_UNSPEC) // TODO: make it shorter if base.Flags&FlagUp != 0 { msg.Change = syscall.IFF_UP msg.Flags = syscall.IFF_UP } if base.Flags&FlagBroadcast != 0 { msg.Change |= syscall.IFF_BROADCAST msg.Flags |= syscall.IFF_BROADCAST } if base.Flags&FlagLoopback != 0 { msg.Change |= syscall.IFF_LOOPBACK msg.Flags |= syscall.IFF_LOOPBACK } if base.Flags&FlagPointToPoint != 0 { msg.Change |= syscall.IFF_POINTOPOINT msg.Flags |= syscall.IFF_POINTOPOINT } if base.Flags&FlagMulticast != 0 { msg.Change |= syscall.IFF_MULTICAST msg.Flags |= syscall.IFF_MULTICAST } if base.Flags&FlagRunning != 0 { msg.Change |= syscall.IFF_RUNNING msg.Flags |= syscall.IFF_RUNNING } req.AddData(msg) if base.ParentIndex != 0 { b := make([]byte, 4) native.PutUint32(b, uint32(base.ParentIndex)) data := nl.NewRtAttr(syscall.IFLA_LINK, b) req.AddData(data) } else if link.Type() == "ipvlan" { return fmt.Errorf("Can't create ipvlan link without ParentIndex") } nameData := nl.NewRtAttr(syscall.IFLA_IFNAME, nl.ZeroTerminated(base.Name)) req.AddData(nameData) if base.MTU > 0 { mtu := nl.NewRtAttr(syscall.IFLA_MTU, nl.Uint32Attr(uint32(base.MTU))) req.AddData(mtu) } if base.TxQLen >= 0 { qlen := nl.NewRtAttr(syscall.IFLA_TXQLEN, nl.Uint32Attr(uint32(base.TxQLen))) req.AddData(qlen) } if base.Namespace != nil { var attr *nl.RtAttr switch base.Namespace.(type) { case NsPid: val := nl.Uint32Attr(uint32(base.Namespace.(NsPid))) attr = nl.NewRtAttr(syscall.IFLA_NET_NS_PID, val) case NsFd: val := nl.Uint32Attr(uint32(base.Namespace.(NsFd))) attr = nl.NewRtAttr(nl.IFLA_NET_NS_FD, val) } req.AddData(attr) } linkInfo := nl.NewRtAttr(syscall.IFLA_LINKINFO, nil) nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_KIND, nl.NonZeroTerminated(link.Type())) if vlan, ok := link.(*Vlan); ok { b := make([]byte, 2) native.PutUint16(b, uint16(vlan.VlanId)) data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil) nl.NewRtAttrChild(data, nl.IFLA_VLAN_ID, b) } else if veth, ok := link.(*Veth); ok { data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil) peer := nl.NewRtAttrChild(data, nl.VETH_INFO_PEER, nil) nl.NewIfInfomsgChild(peer, syscall.AF_UNSPEC) nl.NewRtAttrChild(peer, syscall.IFLA_IFNAME, nl.ZeroTerminated(veth.PeerName)) if base.TxQLen >= 0 { nl.NewRtAttrChild(peer, syscall.IFLA_TXQLEN, nl.Uint32Attr(uint32(base.TxQLen))) } if base.MTU > 0 { nl.NewRtAttrChild(peer, syscall.IFLA_MTU, nl.Uint32Attr(uint32(base.MTU))) } } else if vxlan, ok := link.(*Vxlan); ok { addVxlanAttrs(vxlan, linkInfo) } else if bond, ok := link.(*Bond); ok { addBondAttrs(bond, linkInfo) } else if ipv, ok := link.(*IPVlan); ok { data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil) nl.NewRtAttrChild(data, nl.IFLA_IPVLAN_MODE, nl.Uint16Attr(uint16(ipv.Mode))) } else if macv, ok := link.(*Macvlan); ok { if macv.Mode != MACVLAN_MODE_DEFAULT { data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil) nl.NewRtAttrChild(data, nl.IFLA_MACVLAN_MODE, nl.Uint32Attr(macvlanModes[macv.Mode])) } } else if gretap, ok := link.(*Gretap); ok { addGretapAttrs(gretap, linkInfo) } req.AddData(linkInfo) _, err := req.Execute(syscall.NETLINK_ROUTE, 0) if err != nil { return err } ensureIndex(base) // can't set master during create, so set it afterwards if base.MasterIndex != 0 { // TODO: verify MasterIndex is actually a bridge? return LinkSetMasterByIndex(link, base.MasterIndex) } return nil }
func addBondAttrs(bond *Bond, linkInfo *nl.RtAttr) { data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil) if bond.Mode >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_MODE, nl.Uint8Attr(uint8(bond.Mode))) } if bond.ActiveSlave >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_ACTIVE_SLAVE, nl.Uint32Attr(uint32(bond.ActiveSlave))) } if bond.Miimon >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_MIIMON, nl.Uint32Attr(uint32(bond.Miimon))) } if bond.UpDelay >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_UPDELAY, nl.Uint32Attr(uint32(bond.UpDelay))) } if bond.DownDelay >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_DOWNDELAY, nl.Uint32Attr(uint32(bond.DownDelay))) } if bond.UseCarrier >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_USE_CARRIER, nl.Uint8Attr(uint8(bond.UseCarrier))) } if bond.ArpInterval >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_ARP_INTERVAL, nl.Uint32Attr(uint32(bond.ArpInterval))) } if bond.ArpIpTargets != nil { msg := nl.NewRtAttrChild(data, nl.IFLA_BOND_ARP_IP_TARGET, nil) for i := range bond.ArpIpTargets { ip := bond.ArpIpTargets[i].To4() if ip != nil { nl.NewRtAttrChild(msg, i, []byte(ip)) continue } ip = bond.ArpIpTargets[i].To16() if ip != nil { nl.NewRtAttrChild(msg, i, []byte(ip)) } } } if bond.ArpValidate >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_ARP_VALIDATE, nl.Uint32Attr(uint32(bond.ArpValidate))) } if bond.ArpAllTargets >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_ARP_ALL_TARGETS, nl.Uint32Attr(uint32(bond.ArpAllTargets))) } if bond.Primary >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_PRIMARY, nl.Uint32Attr(uint32(bond.Primary))) } if bond.PrimaryReselect >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_PRIMARY_RESELECT, nl.Uint8Attr(uint8(bond.PrimaryReselect))) } if bond.FailOverMac >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_FAIL_OVER_MAC, nl.Uint8Attr(uint8(bond.FailOverMac))) } if bond.XmitHashPolicy >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_XMIT_HASH_POLICY, nl.Uint8Attr(uint8(bond.XmitHashPolicy))) } if bond.ResendIgmp >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_RESEND_IGMP, nl.Uint32Attr(uint32(bond.ResendIgmp))) } if bond.NumPeerNotif >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_NUM_PEER_NOTIF, nl.Uint8Attr(uint8(bond.NumPeerNotif))) } if bond.AllSlavesActive >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_ALL_SLAVES_ACTIVE, nl.Uint8Attr(uint8(bond.AllSlavesActive))) } if bond.MinLinks >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_MIN_LINKS, nl.Uint32Attr(uint32(bond.MinLinks))) } if bond.LpInterval >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_LP_INTERVAL, nl.Uint32Attr(uint32(bond.LpInterval))) } if bond.PackersPerSlave >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_PACKETS_PER_SLAVE, nl.Uint32Attr(uint32(bond.PackersPerSlave))) } if bond.LacpRate >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_AD_LACP_RATE, nl.Uint8Attr(uint8(bond.LacpRate))) } if bond.AdSelect >= 0 { nl.NewRtAttrChild(data, nl.IFLA_BOND_AD_SELECT, nl.Uint8Attr(uint8(bond.AdSelect))) } }
func addVxlanAttrs(vxlan *Vxlan, linkInfo *nl.RtAttr) { data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_ID, nl.Uint32Attr(uint32(vxlan.VxlanId))) if vxlan.VtepDevIndex != 0 { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_LINK, nl.Uint32Attr(uint32(vxlan.VtepDevIndex))) } if vxlan.SrcAddr != nil { ip := vxlan.SrcAddr.To4() if ip != nil { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_LOCAL, []byte(ip)) } else { ip = vxlan.SrcAddr.To16() if ip != nil { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_LOCAL6, []byte(ip)) } } } if vxlan.Group != nil { group := vxlan.Group.To4() if group != nil { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_GROUP, []byte(group)) } else { group = vxlan.Group.To16() if group != nil { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_GROUP6, []byte(group)) } } } nl.NewRtAttrChild(data, nl.IFLA_VXLAN_TTL, nl.Uint8Attr(uint8(vxlan.TTL))) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_TOS, nl.Uint8Attr(uint8(vxlan.TOS))) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_LEARNING, boolAttr(vxlan.Learning)) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_PROXY, boolAttr(vxlan.Proxy)) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_RSC, boolAttr(vxlan.RSC)) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_L2MISS, boolAttr(vxlan.L2miss)) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_L3MISS, boolAttr(vxlan.L3miss)) if vxlan.UDPCSum { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_UDP_CSUM, boolAttr(vxlan.UDPCSum)) } if vxlan.GBP { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_GBP, boolAttr(vxlan.GBP)) } if vxlan.NoAge { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_AGEING, nl.Uint32Attr(0)) } else if vxlan.Age > 0 { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_AGEING, nl.Uint32Attr(uint32(vxlan.Age))) } if vxlan.Limit > 0 { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_LIMIT, nl.Uint32Attr(uint32(vxlan.Limit))) } if vxlan.Port > 0 { nl.NewRtAttrChild(data, nl.IFLA_VXLAN_PORT, nl.Uint16Attr(uint16(vxlan.Port))) } if vxlan.PortLow > 0 || vxlan.PortHigh > 0 { pr := vxlanPortRange{uint16(vxlan.PortLow), uint16(vxlan.PortHigh)} buf := new(bytes.Buffer) binary.Write(buf, binary.BigEndian, &pr) nl.NewRtAttrChild(data, nl.IFLA_VXLAN_PORT_RANGE, buf.Bytes()) } }
func addGretapAttrs(gretap *Gretap, linkInfo *nl.RtAttr) { data := nl.NewRtAttrChild(linkInfo, nl.IFLA_INFO_DATA, nil) ip := gretap.Local.To4() if ip != nil { nl.NewRtAttrChild(data, nl.IFLA_GRE_LOCAL, []byte(ip)) } ip = gretap.Remote.To4() if ip != nil { nl.NewRtAttrChild(data, nl.IFLA_GRE_REMOTE, []byte(ip)) } if gretap.IKey != 0 { nl.NewRtAttrChild(data, nl.IFLA_GRE_IKEY, htonl(gretap.IKey)) gretap.IFlags |= uint16(nl.GRE_KEY) } if gretap.OKey != 0 { nl.NewRtAttrChild(data, nl.IFLA_GRE_OKEY, htonl(gretap.OKey)) gretap.OFlags |= uint16(nl.GRE_KEY) } nl.NewRtAttrChild(data, nl.IFLA_GRE_IFLAGS, htons(gretap.IFlags)) nl.NewRtAttrChild(data, nl.IFLA_GRE_OFLAGS, htons(gretap.OFlags)) if gretap.Link != 0 { nl.NewRtAttrChild(data, nl.IFLA_GRE_LINK, nl.Uint32Attr(gretap.Link)) } nl.NewRtAttrChild(data, nl.IFLA_GRE_PMTUDISC, nl.Uint8Attr(gretap.PMtuDisc)) nl.NewRtAttrChild(data, nl.IFLA_GRE_TTL, nl.Uint8Attr(gretap.Ttl)) nl.NewRtAttrChild(data, nl.IFLA_GRE_TOS, nl.Uint8Attr(gretap.Tos)) nl.NewRtAttrChild(data, nl.IFLA_GRE_ENCAP_TYPE, nl.Uint16Attr(gretap.EncapType)) nl.NewRtAttrChild(data, nl.IFLA_GRE_ENCAP_FLAGS, nl.Uint16Attr(gretap.EncapFlags)) nl.NewRtAttrChild(data, nl.IFLA_GRE_ENCAP_SPORT, htons(gretap.EncapSport)) nl.NewRtAttrChild(data, nl.IFLA_GRE_ENCAP_DPORT, htons(gretap.EncapDport)) }