Example #1
0
// 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()))

	nl.NewRtAttrChild(linkInfo, syscall.IFLA_TXQLEN, nl.Uint32Attr(base.TxQLen))

	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))
		nl.NewRtAttrChild(peer, syscall.IFLA_TXQLEN, nl.Uint32Attr(base.TxQLen))
	} 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
}
Example #2
0
// 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
}
Example #3
0
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
}