func NewNetNSContextByNode(g *graph.Graph, n *graph.Node) (*common.NetNSContext, error) {
name, ok := n.Metadata()["Name"]
if !ok || name == "" {
return nil, fmt.Errorf("No name for node %v", n)
}
ifName := name.(string)
nodes := g.LookupShortestPath(n, graph.Metadata{"Type": "host"}, graph.Metadata{"RelationType": "ownership"})
if len(nodes) == 0 {
return nil, fmt.Errorf("Failed to determine probePath for %s", ifName)
}
for _, node := range nodes {
if node.Metadata()["Type"] == "netns" {
name := node.Metadata()["Name"].(string)
path := node.Metadata()["Path"].(string)
logging.GetLogger().Debugf("Switching to namespace %s (path: %s)", name, path)
return common.NewNetNsContext(path)
}
}
return nil, nil
}
func (u *NetLinkProbe) start(nsPath string) {
var context *common.NetNSContext
var err error
// Enter the network namespace if necessary
if nsPath != "" {
context, err = common.NewNetNsContext(nsPath)
if err != nil {
logging.GetLogger().Errorf("Failed to switch namespace: %s", err.Error())
return
}
}
// Both NewHandle and Subscribe need to done in the network namespace.
h, err := netlink.NewHandle(syscall.NETLINK_ROUTE)
if err != nil {
logging.GetLogger().Errorf("Failed to create netlink handle: %s", err.Error())
context.Close()
return
}
defer h.Delete()
s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_LINK, syscall.RTNLGRP_IPV4_IFADDR, syscall.RTNLGRP_IPV6_IFADDR)
if err != nil {
logging.GetLogger().Errorf("Failed to subscribe to netlink messages: %s", err.Error())
context.Close()
return
}
defer s.Close()
u.ethtool, err = ethtool.NewEthtool()
if err != nil {
logging.GetLogger().Errorf("Failed to create ethtool object: %s", err.Error())
context.Close()
return
}
defer u.ethtool.Close()
epfd, e := syscall.EpollCreate1(0)
if e != nil {
logging.GetLogger().Errorf("Failed to create epoll: %s", err.Error())
return
}
defer syscall.Close(epfd)
// Leave the network namespace
context.Close()
u.wg.Add(1)
defer u.wg.Done()
atomic.StoreInt64(&u.state, common.RunningState)
defer atomic.StoreInt64(&u.state, common.StoppedState)
u.netlink = h
u.initialize()
fd := s.GetFd()
err = syscall.SetNonblock(fd, true)
if err != nil {
logging.GetLogger().Errorf("Failed to set the netlink fd as non-blocking: %s", err.Error())
return
}
event := syscall.EpollEvent{Events: syscall.EPOLLIN, Fd: int32(fd)}
if err = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, fd, &event); err != nil {
logging.GetLogger().Errorf("Failed to control epoll: %s", err.Error())
return
}
events := make([]syscall.EpollEvent, maxEpollEvents)
for atomic.LoadInt64(&u.state) == common.RunningState {
n, err := syscall.EpollWait(epfd, events[:], 1000)
if err != nil {
errno, ok := err.(syscall.Errno)
if ok && errno != syscall.EINTR {
logging.GetLogger().Errorf("Failed to receive from events from netlink: %s", err.Error())
}
continue
}
if n == 0 {
continue
}
msgs, err := s.Receive()
if err != nil {
if errno, ok := err.(syscall.Errno); !ok || !errno.Temporary() {
logging.GetLogger().Errorf("Failed to receive from netlink messages: %s", err.Error())
return
}
time.Sleep(1 * time.Second)
continue
}
for _, msg := range msgs {
switch msg.Header.Type {
case syscall.RTM_NEWLINK:
link, err := netlink.LinkDeserialize(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to deserialize netlink message: %s", err.Error())
continue
}
u.onLinkAdded(link)
case syscall.RTM_DELLINK:
link, err := netlink.LinkDeserialize(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to deserialize netlink message: %s", err.Error())
continue
}
u.onLinkDeleted(link)
case syscall.RTM_NEWADDR:
addr, family, ifindex, err := parseAddr(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to parse newlink message: %s", err.Error())
continue
}
u.onAddressAdded(addr, family, ifindex)
case syscall.RTM_DELADDR:
addr, family, ifindex, err := parseAddr(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to parse newlink message: %s", err.Error())
continue
}
u.onAddressDeleted(addr, family, ifindex)
}
}
}
}