// LinkSubscribe takes a chan down which notifications will be sent
// when links change. Close the 'done' chan to stop subscription.
func LinkSubscribe(ch chan<- LinkUpdate, done <-chan struct{}) error {
s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_LINK)
if err != nil {
return err
}
if done != nil {
go func() {
<-done
s.Close()
}()
}
go func() {
defer close(ch)
for {
msgs, err := s.Receive()
if err != nil {
return
}
for _, m := range msgs {
ifmsg := nl.DeserializeIfInfomsg(m.Data)
link, err := linkDeserialize(m.Data)
if err != nil {
return
}
ch <- LinkUpdate{IfInfomsg: *ifmsg, Header: m.Header, Link: link}
}
}
}()
return nil
}
// RouteSubscribe takes a chan down which notifications will be sent
// when routes are added or deleted. Close the 'done' chan to stop subscription.
func RouteSubscribe(ch chan<- RouteUpdate, done <-chan struct{}) error {
s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_IPV4_ROUTE, syscall.RTNLGRP_IPV6_ROUTE)
if err != nil {
return err
}
if done != nil {
go func() {
<-done
s.Close()
}()
}
go func() {
defer close(ch)
for {
msgs, err := s.Receive()
if err != nil {
return
}
for _, m := range msgs {
route, err := deserializeRoute(m.Data)
if err != nil {
return
}
ch <- RouteUpdate{Type: m.Header.Type, Route: route}
}
}
}()
return nil
}
// AddrSubscribe takes a chan down which notifications will be sent
// when addresses change. Close the 'done' chan to stop subscription.
func AddrSubscribe(ch chan<- AddrUpdate, done <-chan struct{}) error {
s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_IPV4_IFADDR, syscall.RTNLGRP_IPV6_IFADDR)
if err != nil {
return err
}
if done != nil {
go func() {
<-done
s.Close()
}()
}
go func() {
defer close(ch)
for {
msgs, err := s.Receive()
if err != nil {
log.Printf("netlink.AddrSubscribe: Receive() error: %v", err)
return
}
for _, m := range msgs {
msgType := m.Header.Type
if msgType != syscall.RTM_NEWADDR && msgType != syscall.RTM_DELADDR {
log.Printf("netlink.AddrSubscribe: bad message type: %d", msgType)
continue
}
msg := nl.DeserializeIfAddrmsg(m.Data)
attrs, err := nl.ParseRouteAttr(m.Data[msg.Len():])
if err != nil {
log.Printf("netlink.AddrSubscribe: nl.ParseRouteAttr() error: %v", err)
return
}
var local, dst *net.IPNet
var addr Addr
for _, attr := range attrs {
switch attr.Attr.Type {
case syscall.IFA_ADDRESS:
dst = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)),
}
case syscall.IFA_LOCAL:
local = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)),
}
case syscall.IFA_LABEL:
addr.Label = string(attr.Value[:len(attr.Value)-1])
case IFA_FLAGS:
addr.Flags = int(native.Uint32(attr.Value[0:4]))
}
}
// IFA_LOCAL should be there but if not, fall back to IFA_ADDRESS
if local != nil {
addr.IPNet = local
} else {
addr.IPNet = dst
}
ch <- AddrUpdate{LinkAddress: *addr.IPNet, LinkIndex: int(msg.Index), NewAddr: msgType == syscall.RTM_NEWADDR}
}
}
}()
return nil
}