func (self *LinkHandler) SetLinkState(flag link.Flags) (err error) {
var qry *netlink.Message
if hdr, ok := self.cache.Header.(*link.Header); ok {
// While rtnetlink(7) says changes should always be IFF_QUERY, it has some
// behaviours that are undocumented - like limiting actions on SETLINK's to
// specific FLAGs.
hdr = link.NewHeader(hdr.InterfaceFamily(), hdr.InterfaceType(), hdr.InterfaceIndex(), flag&link.IFF_UP, link.IFF_UP)
msg := rtnetlink.Message{Header: hdr}
qry, err = netlink.NewMessage(rtnetlink.RTM_SETLINK, netlink.NLM_F_ACK|netlink.NLM_F_REQUEST, msg)
} else {
err = errors.New("Cant set link flags (invalid cache)")
}
if err != nil {
return
}
mch, err := self.h.Query(*qry, 1)
if err == nil {
for m := range mch {
switch m.Header.MessageType() {
case netlink.NLMSG_ERROR:
emsg := &netlink.Error{}
err = emsg.UnmarshalNetlink(m.Body)
if err == nil && emsg.Code() != 0 {
err = emsg
}
default:
err = errors.New("Unexpected netlink message")
log.Printf("NetlinkError: %v", err)
}
}
close(mch)
}
return
}
func (self *linkFinder) GetLinkByID(i uint32) (lh *LinkHandler, err error) {
qry, err := netlink.NewMessage(rtnetlink.RTM_GETLINK, netlink.NLM_F_REQUEST,
link.NewHeader(rtnetlink.AF_UNSPEC, 0, i, 0, 0))
if err == nil {
var mch chan netlink.Message
mch, err = self.h.Query(*qry, 1)
if err == nil {
for ii := range mch {
switch ii.Header.MessageType() {
default:
err = errors.New("Unknown message type in response to RTM_GETLINK")
case netlink.NLMSG_ERROR:
emsg := &netlink.Error{}
err = emsg.UnmarshalNetlink(ii.Body)
if err == nil && emsg.Code() != 0 {
err = emsg
}
case rtnetlink.RTM_NEWLINK:
lhdr := &link.Header{}
msg := &rtnetlink.Message{Header: lhdr}
err = msg.UnmarshalNetlink(ii.Body)
if err == nil {
lh = &LinkHandler{h: self.h, cache: msg}
}
}
}
close(mch)
}
}
return
}
func main() {
// This imitates the functionality of rtnl_wilddump_req_filter from bridge/vlan.c in the
// iproute2 code. Note that the filter requires kernel 3.9 or newer
data := make([]byte, 4)
binary.LittleEndian.PutUint32(data, link.RTEXT_FILTER_BRVLAN)
lnmsg := link.NewHeader(rtnetlink.AF_BRIDGE, 0, 0, 0, 0)
msg := rtnetlink.NewMessage(lnmsg, []netlink.Attribute{{link.IFLA_EXT_MASK, data}})
nlmsg, err := netlink.NewMessage(rtnetlink.RTM_GETLINK, netlink.NLM_F_DUMP|netlink.NLM_F_REQUEST, msg)
if err != nil {
log.Panicf("Couldn't construct message: %v", err)
}
nlsock, err := netlink.Dial(netlink.NETLINK_ROUTE)
if err != nil {
log.Panicf("Couldn't dial netlink: %v", err)
}
h := netlink.NewHandler(nlsock)
ec := make(chan error)
go h.Start(ec)
c, err := h.Query(*nlmsg, 1)
if err != nil {
log.Panicf("Couldn't write netlink: %v", err)
}
for i := range c {
if i.Header.MessageType() == netlink.NLMSG_DONE {
break
}
switch i.Header.MessageType() {
case rtnetlink.RTM_NEWLINK:
hdr := &link.Header{}
msg := rtnetlink.NewMessage(hdr, nil)
err = msg.UnmarshalNetlink(i.Body)
if err == nil {
log.Printf("Link[%d] (Family: %v; Type: %v; Flags: %v; Changes: %v)",
hdr.InterfaceIndex(),
hdr.InterfaceFamily(), hdr.InterfaceType(), hdr.Flags(),
hdr.InterfaceChanges())
for i := range msg.Attributes {
log.Printf("Attribute[%d]: %v", i, msg.Attributes[i])
}
} else {
log.Printf("Unmarshal error: %v", err)
}
default:
log.Printf("Unknown type: %v", i)
}
}
}
func (self *linkFinder) GetLinks() (lhs []*LinkHandler, err error) {
qry, err := netlink.NewMessage(rtnetlink.RTM_GETLINK, netlink.NLM_F_REQUEST|netlink.NLM_F_ROOT,
link.NewHeader(rtnetlink.AF_UNSPEC, 0, 0, 0, 0))
if err != nil {
return
}
var mch chan netlink.Message
mch, err = self.h.Query(*qry, 1)
if err == nil {
for ii := range mch {
if ii.Header.MessageType() == netlink.NLMSG_DONE {
break
}
switch ii.Header.MessageType() {
default:
err = errors.New("Unknown message type in response to RTM_GETLINK")
case netlink.NLMSG_ERROR:
emsg := &netlink.Error{}
err = emsg.UnmarshalNetlink(ii.Body)
if err == nil && emsg.Code() != 0 {
err = emsg
}
case rtnetlink.RTM_NEWLINK:
lhdr := &link.Header{}
msg := &rtnetlink.Message{Header: lhdr}
err = msg.UnmarshalNetlink(ii.Body)
if err == nil {
lhs = append(lhs, &LinkHandler{h: self.h, cache: msg})
}
}
if err != nil {
log.Printf("Internal netlink failure: %v", err)
}
}
}
close(mch)
return
}