// 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
}
func neighHandle(neigh *Neigh, req *nl.NetlinkRequest) error {
var family int
if neigh.Family > 0 {
family = neigh.Family
} else {
family = nl.GetIPFamily(neigh.IP)
}
msg := Ndmsg{
Family: uint8(family),
Index: uint32(neigh.LinkIndex),
State: uint16(neigh.State),
Type: uint8(neigh.Type),
Flags: uint8(neigh.Flags),
}
req.AddData(&msg)
ipData := neigh.IP.To4()
if ipData == nil {
ipData = neigh.IP.To16()
}
dstData := nl.NewRtAttr(NDA_DST, ipData)
req.AddData(dstData)
hwData := nl.NewRtAttr(NDA_LLADDR, []byte(neigh.HardwareAddr))
req.AddData(hwData)
_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
return err
}
// XfrmPolicyAdd will add an xfrm policy to the system.
// Equivalent to: `ip xfrm policy add $policy`
func XfrmPolicyAdd(policy *XfrmPolicy) error {
req := nl.NewNetlinkRequest(nl.XFRM_MSG_NEWPOLICY, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
msg := &nl.XfrmUserpolicyInfo{}
selFromPolicy(&msg.Sel, policy)
msg.Priority = uint32(policy.Priority)
msg.Index = uint32(policy.Index)
msg.Dir = uint8(policy.Dir)
msg.Lft.SoftByteLimit = nl.XFRM_INF
msg.Lft.HardByteLimit = nl.XFRM_INF
msg.Lft.SoftPacketLimit = nl.XFRM_INF
msg.Lft.HardPacketLimit = nl.XFRM_INF
req.AddData(msg)
tmplData := make([]byte, nl.SizeofXfrmUserTmpl*len(policy.Tmpls))
for i, tmpl := range policy.Tmpls {
start := i * nl.SizeofXfrmUserTmpl
userTmpl := nl.DeserializeXfrmUserTmpl(tmplData[start : start+nl.SizeofXfrmUserTmpl])
userTmpl.XfrmId.Daddr.FromIP(tmpl.Dst)
userTmpl.Saddr.FromIP(tmpl.Src)
userTmpl.XfrmId.Proto = uint8(tmpl.Proto)
userTmpl.Mode = uint8(tmpl.Mode)
userTmpl.Reqid = uint32(tmpl.Reqid)
userTmpl.Aalgos = ^uint32(0)
userTmpl.Ealgos = ^uint32(0)
userTmpl.Calgos = ^uint32(0)
}
if len(tmplData) > 0 {
tmpls := nl.NewRtAttr(nl.XFRMA_TMPL, tmplData)
req.AddData(tmpls)
}
_, err := req.Execute(syscall.NETLINK_XFRM, 0)
return err
}
// XfrmStateAdd will add an xfrm state to the system.
// Equivalent to: `ip xfrm state add $state`
func XfrmStateAdd(state *XfrmState) error {
// A state with spi 0 can't be deleted so don't allow it to be set
if state.Spi == 0 {
return fmt.Errorf("Spi must be set when adding xfrm state.")
}
req := nl.NewNetlinkRequest(nl.XFRM_MSG_NEWSA, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
msg := &nl.XfrmUsersaInfo{}
msg.Family = uint16(nl.GetIPFamily(state.Dst))
msg.Id.Daddr.FromIP(state.Dst)
msg.Saddr.FromIP(state.Src)
msg.Id.Proto = uint8(state.Proto)
msg.Mode = uint8(state.Mode)
msg.Id.Spi = nl.Swap32(uint32(state.Spi))
msg.Reqid = uint32(state.Reqid)
msg.ReplayWindow = uint8(state.ReplayWindow)
msg.Lft.SoftByteLimit = nl.XFRM_INF
msg.Lft.HardByteLimit = nl.XFRM_INF
msg.Lft.SoftPacketLimit = nl.XFRM_INF
msg.Lft.HardPacketLimit = nl.XFRM_INF
req.AddData(msg)
if state.Auth != nil {
out := nl.NewRtAttr(nl.XFRMA_ALG_AUTH_TRUNC, writeStateAlgoAuth(state.Auth))
req.AddData(out)
}
if state.Crypt != nil {
out := nl.NewRtAttr(nl.XFRMA_ALG_CRYPT, writeStateAlgo(state.Crypt))
req.AddData(out)
}
if state.Encap != nil {
encapData := make([]byte, nl.SizeofXfrmEncapTmpl)
encap := nl.DeserializeXfrmEncapTmpl(encapData)
encap.EncapType = uint16(state.Encap.Type)
encap.EncapSport = nl.Swap16(uint16(state.Encap.SrcPort))
encap.EncapDport = nl.Swap16(uint16(state.Encap.DstPort))
encap.EncapOa.FromIP(state.Encap.OriginalAddress)
out := nl.NewRtAttr(nl.XFRMA_ENCAP, encapData)
req.AddData(out)
}
_, err := req.Execute(syscall.NETLINK_XFRM, 0)
return err
}
// RouteGet gets a route to a specific destination from the host system.
// Equivalent to: 'ip route get'.
func RouteGet(destination net.IP) ([]Route, error) {
req := nl.NewNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_REQUEST)
family := nl.GetIPFamily(destination)
var destinationData []byte
var bitlen uint8
if family == FAMILY_V4 {
destinationData = destination.To4()
bitlen = 32
} else {
destinationData = destination.To16()
bitlen = 128
}
msg := &nl.RtMsg{}
msg.Family = uint8(family)
msg.Dst_len = bitlen
req.AddData(msg)
rtaDst := nl.NewRtAttr(syscall.RTA_DST, destinationData)
req.AddData(rtaDst)
msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
if err != nil {
return nil, err
}
native := nl.NativeEndian()
res := make([]Route, 0)
for _, m := range msgs {
msg := nl.DeserializeRtMsg(m)
attrs, err := nl.ParseRouteAttr(m[msg.Len():])
if err != nil {
return nil, err
}
route := Route{}
for _, attr := range attrs {
switch attr.Attr.Type {
case syscall.RTA_GATEWAY:
route.Gw = net.IP(attr.Value)
case syscall.RTA_PREFSRC:
route.Src = net.IP(attr.Value)
case syscall.RTA_DST:
route.Dst = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
}
case syscall.RTA_OIF:
routeIndex := int(native.Uint32(attr.Value[0:4]))
route.LinkIndex = routeIndex
}
}
res = append(res, route)
}
return res, nil
}
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
}
// LinkSetName sets the name of the link device.
// Equivalent to: `ip link set $link name $name`
func LinkSetName(link Link, name string) error {
base := link.Attrs()
ensureIndex(base)
req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
msg.Type = syscall.RTM_SETLINK
msg.Flags = syscall.NLM_F_REQUEST
msg.Index = int32(base.Index)
msg.Change = nl.DEFAULT_CHANGE
req.AddData(msg)
data := nl.NewRtAttr(syscall.IFLA_IFNAME, []byte(name))
req.AddData(data)
_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
return err
}
// XfrmStateDel will delete an xfrm state from the system. Note that
// the Algos are ignored when matching the state to delete.
// Equivalent to: `ip xfrm state del $state`
func XfrmStateDel(state *XfrmState) error {
req := nl.NewNetlinkRequest(nl.XFRM_MSG_DELSA, syscall.NLM_F_ACK)
msg := &nl.XfrmUsersaId{}
msg.Daddr.FromIP(state.Dst)
msg.Family = uint16(nl.GetIPFamily(state.Dst))
msg.Proto = uint8(state.Proto)
msg.Spi = nl.Swap32(uint32(state.Spi))
req.AddData(msg)
saddr := nl.XfrmAddress{}
saddr.FromIP(state.Src)
srcdata := nl.NewRtAttr(nl.XFRMA_SRCADDR, saddr.Serialize())
req.AddData(srcdata)
_, err := req.Execute(syscall.NETLINK_XFRM, 0)
return err
}
// LinkSetMTU sets the mtu of the link device.
// Equivalent to: `ip link set $link mtu $mtu`
func LinkSetMTU(link Link, mtu int) error {
base := link.Attrs()
ensureIndex(base)
req := nl.NewNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
msg.Type = syscall.RTM_SETLINK
msg.Flags = syscall.NLM_F_REQUEST
msg.Index = int32(base.Index)
msg.Change = nl.DEFAULT_CHANGE
req.AddData(msg)
b := make([]byte, 4)
native.PutUint32(b, uint32(mtu))
data := nl.NewRtAttr(syscall.IFLA_MTU, b)
req.AddData(data)
_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
return err
}
// 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 routeHandle(route *Route, req *nl.NetlinkRequest) error {
if route.Dst.IP == nil && route.Src == nil && route.Gw == nil {
return fmt.Errorf("one of Dst.IP, Src, or Gw must not be nil")
}
msg := nl.NewRtMsg()
msg.Scope = uint8(route.Scope)
family := -1
var rtAttrs []*nl.RtAttr
if route.Dst.IP != nil {
dstLen, _ := route.Dst.Mask.Size()
msg.Dst_len = uint8(dstLen)
dstFamily := nl.GetIPFamily(route.Dst.IP)
family = dstFamily
var dstData []byte
if dstFamily == FAMILY_V4 {
dstData = route.Dst.IP.To4()
} else {
dstData = route.Dst.IP.To16()
}
rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_DST, dstData))
}
if route.Src != nil {
srcFamily := nl.GetIPFamily(route.Src)
if family != -1 && family != srcFamily {
return fmt.Errorf("source and destination ip are not the same IP family")
}
family = srcFamily
var srcData []byte
if srcFamily == FAMILY_V4 {
srcData = route.Src.To4()
} else {
srcData = route.Src.To16()
}
// The commonly used src ip for routes is actually PREFSRC
rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_PREFSRC, srcData))
}
if route.Gw != nil {
gwFamily := nl.GetIPFamily(route.Gw)
if family != -1 && family != gwFamily {
return fmt.Errorf("gateway, source, and destination ip are not the same IP family")
}
family = gwFamily
var gwData []byte
if gwFamily == FAMILY_V4 {
gwData = route.Gw.To4()
} else {
gwData = route.Gw.To16()
}
rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_GATEWAY, gwData))
}
msg.Family = uint8(family)
req.AddData(msg)
for _, attr := range rtAttrs {
req.AddData(attr)
}
var (
b = make([]byte, 4)
native = nl.NativeEndian()
)
native.PutUint32(b, uint32(route.LinkIndex))
req.AddData(nl.NewRtAttr(syscall.RTA_OIF, b))
_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
return err
}