// 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!")
}
req := nl.NewNetlinkRequest(syscall.RTM_NEWLINK, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
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)
}
nameData := nl.NewRtAttr(syscall.IFLA_IFNAME, nl.ZeroTerminated(base.Name))
req.AddData(nameData)
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))
} else if vxlan, ok := link.(*Vxlan); ok {
addVxlanAttrs(vxlan, 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
}
// LinkByName finds a link by name and returns a pointer to the object.
func LinkByName(name string) (Link, error) {
if lookupByDump {
return linkByNameDump(name)
}
req := nl.NewNetlinkRequest(syscall.RTM_GETLINK, syscall.NLM_F_ACK)
msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
req.AddData(msg)
nameData := nl.NewRtAttr(syscall.IFLA_IFNAME, nl.ZeroTerminated(name))
req.AddData(nameData)
link, err := execGetLink(req)
if err == syscall.EINVAL {
// older kernels don't support looking up via IFLA_IFNAME
// so fall back to dumping all links
lookupByDump = true
return linkByNameDump(name)
}
return link, err
}
func addrHandle(link Link, addr *Addr, req *nl.NetlinkRequest) error {
base := link.Attrs()
if addr.Label != "" && !strings.HasPrefix(addr.Label, base.Name) {
return fmt.Errorf("label must begin with interface name")
}
ensureIndex(base)
family := nl.GetIPFamily(addr.IP)
msg := nl.NewIfAddrmsg(family)
msg.Index = uint32(base.Index)
prefixlen, _ := addr.Mask.Size()
msg.Prefixlen = uint8(prefixlen)
req.AddData(msg)
var addrData []byte
if family == FAMILY_V4 {
addrData = addr.IP.To4()
} else {
addrData = addr.IP.To16()
}
localData := nl.NewRtAttr(syscall.IFA_LOCAL, addrData)
req.AddData(localData)
addressData := nl.NewRtAttr(syscall.IFA_ADDRESS, addrData)
req.AddData(addressData)
if addr.Label != "" {
labelData := nl.NewRtAttr(syscall.IFA_LABEL, nl.ZeroTerminated(addr.Label))
req.AddData(labelData)
}
_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
return err
}