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- package networkdriver
- import (
- "errors"
- "fmt"
- "net"
- "github.com/docker/libcontainer/netlink"
- )
- var (
- networkGetRoutesFct = netlink.NetworkGetRoutes
- ErrNoDefaultRoute = errors.New("no default route")
- )
- func CheckNameserverOverlaps(nameservers []string, toCheck *net.IPNet) error {
- if len(nameservers) > 0 {
- for _, ns := range nameservers {
- _, nsNetwork, err := net.ParseCIDR(ns)
- if err != nil {
- return err
- }
- if NetworkOverlaps(toCheck, nsNetwork) {
- return ErrNetworkOverlapsWithNameservers
- }
- }
- }
- return nil
- }
- func CheckRouteOverlaps(toCheck *net.IPNet) error {
- networks, err := networkGetRoutesFct()
- if err != nil {
- return err
- }
- for _, network := range networks {
- if network.IPNet != nil && NetworkOverlaps(toCheck, network.IPNet) {
- return ErrNetworkOverlaps
- }
- }
- return nil
- }
- // Detects overlap between one IPNet and another
- func NetworkOverlaps(netX *net.IPNet, netY *net.IPNet) bool {
- if firstIP, _ := NetworkRange(netX); netY.Contains(firstIP) {
- return true
- }
- if firstIP, _ := NetworkRange(netY); netX.Contains(firstIP) {
- return true
- }
- return false
- }
- // Calculates the first and last IP addresses in an IPNet
- func NetworkRange(network *net.IPNet) (net.IP, net.IP) {
- var netIP net.IP
- if network.IP.To4() != nil {
- netIP = network.IP.To4()
- } else if network.IP.To16() != nil {
- netIP = network.IP.To16()
- } else {
- return nil, nil
- }
- lastIP := make([]byte, len(netIP), len(netIP))
- for i := 0; i < len(netIP); i++ {
- lastIP[i] = netIP[i] | ^network.Mask[i]
- }
- return netIP.Mask(network.Mask), net.IP(lastIP)
- }
- // Return the IPv4 address of a network interface
- func GetIfaceAddr(name string) (net.Addr, error) {
- iface, err := net.InterfaceByName(name)
- if err != nil {
- return nil, err
- }
- addrs, err := iface.Addrs()
- if err != nil {
- return nil, err
- }
- var addrs4 []net.Addr
- for _, addr := range addrs {
- ip := (addr.(*net.IPNet)).IP
- if ip4 := ip.To4(); ip4 != nil {
- addrs4 = append(addrs4, addr)
- }
- }
- switch {
- case len(addrs4) == 0:
- return nil, fmt.Errorf("Interface %v has no IP addresses", name)
- case len(addrs4) > 1:
- fmt.Printf("Interface %v has more than 1 IPv4 address. Defaulting to using %v\n",
- name, (addrs4[0].(*net.IPNet)).IP)
- }
- return addrs4[0], nil
- }
- func GetDefaultRouteIface() (*net.Interface, error) {
- rs, err := networkGetRoutesFct()
- if err != nil {
- return nil, fmt.Errorf("unable to get routes: %v", err)
- }
- for _, r := range rs {
- if r.Default {
- return r.Iface, nil
- }
- }
- return nil, ErrNoDefaultRoute
- }
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