Ejemplo n.º 1
0
// Wait for an interface to come up and have a route added to the multicast subnet.
// This matches the behaviour in 'weave attach', which is the only context in which
// we expect this to be called.  If you change one, change the other to match.
func EnsureInterfaceAndMcastRoute(ifaceName string) (*net.Interface, error) {
	iface, err := ensureInterface(ifaceName)
	if err != nil {
		return nil, err
	}
	ch := make(chan netlink.RouteUpdate)
	done := make(chan struct{})
	defer close(done)
	if err := netlink.RouteSubscribe(ch, done); err != nil {
		return nil, err
	}
	dest := net.IPv4(224, 0, 0, 0)
	check := func(route netlink.Route) bool {
		return route.LinkIndex == iface.Index && route.Dst != nil && route.Dst.IP.Equal(dest)
	}
	// check for currently-existing route after subscribing, to avoid race
	routes, err := netlink.RouteList(nil, netlink.FAMILY_V4)
	if err != nil {
		return nil, err
	}
	for _, route := range routes {
		if check(route) {
			return iface, nil
		}
	}
	for update := range ch {
		if check(update.Route) {
			return iface, nil
		}
	}
	// should never get here
	return iface, nil
}
Ejemplo n.º 2
0
// Wait for an interface to come up and have a route added to the multicast subnet.
// This matches the behaviour in 'weave attach', which is the only context in which
// we expect this to be called.  If you change one, change the other to match.
func EnsureInterfaceAndMcastRoute(ifaceName string) (*net.Interface, error) {
	iface, err := ensureInterface(ifaceName)
	if err != nil {
		return nil, err
	}
	dest := net.IPv4(224, 0, 0, 0)
	if CheckRouteExists(ifaceName, dest) {
		return iface, err
	}
	ch := make(chan netlink.RouteUpdate)
	done := make(chan struct{})
	defer close(done)
	if err := netlink.RouteSubscribe(ch, done); err != nil {
		return nil, err
	}
	for update := range ch {
		link, _ := netlink.LinkByIndex(update.Route.LinkIndex)
		if link.Attrs().Name == ifaceName && update.Route.Dst.IP.Equal(dest) {
			break
		}
	}
	return iface, nil
}
Ejemplo n.º 3
0
// This function should be put into the main process or somewhere that can be
// use to init the network namespace trap.
func setupNetworkNsTrap(netNs2Containerd func(supervisor.NetlinkUpdate)) {

	// Subscribe for links change event
	chLink := make(chan netlink.LinkUpdate)
	doneLink := make(chan struct{})
	defer close(doneLink)
	if err := netlink.LinkSubscribe(chLink, doneLink); err != nil {
		glog.Fatal(err)
	}

	// Subscribe for addresses change event
	chAddr := make(chan netlink.AddrUpdate)
	doneAddr := make(chan struct{})
	defer close(doneAddr)
	if err := netlink.AddrSubscribe(chAddr, doneAddr); err != nil {
		glog.Fatal(err)
	}

	// Subscribe for route change event
	chRoute := make(chan netlink.RouteUpdate)
	doneRoute := make(chan struct{})
	defer close(doneRoute)
	if err := netlink.RouteSubscribe(chRoute, doneRoute); err != nil {
		glog.Fatal(err)
	}

	for {
		select {
		case updateLink := <-chLink:
			handleLink(updateLink, netNs2Containerd)
		case updateAddr := <-chAddr:
			handleAddr(updateAddr, netNs2Containerd)
		case updateRoute := <-chRoute:
			handleRoute(updateRoute, netNs2Containerd)
		}
	}
}