func getDefaultGatewayIface() *net.Interface {
log.V(1).Infof("Attempting to retrieve IP route info from netlink")
routes, err := netlink.NetworkGetRoutes()
if err != nil {
log.V(1).Infof("Unable to detect default interface: %v", err)
return nil
}
if len(routes) == 0 {
log.V(1).Infof("Netlink returned zero routes")
return nil
}
for _, route := range routes {
if route.Default {
if route.Iface == nil {
log.V(1).Infof("Found default route but could not determine interface")
}
log.V(1).Infof("Found default route with interface %v", route.Iface.Name)
return route.Iface
}
}
log.V(1).Infof("Unable to find default route")
return nil
}
func getRoutes(w rest.ResponseWriter, req *rest.Request) {
routes, err := netlink.NetworkGetRoutes()
if err != nil {
log.Printf(err.Error())
rest.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.WriteJson(routes)
}
// getDefaultRouteMtu returns the MTU for the default route's interface.
func getDefaultRouteMtu() (int, error) {
routes, err := netlink.NetworkGetRoutes()
if err != nil {
return 0, err
}
for _, r := range routes {
if r.Default {
return r.Iface.MTU, nil
}
}
return 0, errNoDefaultRoute
}
func getDefaultGatewayIfaceName() (string, error) {
routes, err := netlink.NetworkGetRoutes()
if err != nil {
return "", err
}
for _, route := range routes {
if route.Default {
if route.Iface == nil {
return "", errors.New("found default route but could not determine interface")
}
return route.Iface.Name, nil
}
}
return "", errors.New("unable to find default route")
}
func DefaultExternalIP() (string, error) {
routes, err := netlink.NetworkGetRoutes()
if err != nil {
return "", err
}
var iface *net.Interface
for _, r := range routes {
if r.Default {
iface = r.Iface
break
}
}
if iface == nil {
return "", errors.New("config: Unable to identify default network interface")
}
addrs, err := iface.Addrs()
if err != nil {
return "", err
}
if len(addrs) == 0 {
return "", errors.New("config: No IPs configured on default interface")
}
var defaultIP net.IP
for _, a := range addrs {
ip, _, _ := net.ParseCIDR(a.String())
if ip.To4() != nil && ip.IsGlobalUnicast() {
defaultIP = ip
break
}
}
if defaultIP == nil {
return "", errors.New("config: Unable to determine default IPv4 address")
}
return defaultIP.String(), nil
}