| package networkdriver |
| |
| import ( |
| "encoding/binary" |
| "errors" |
| "fmt" |
| "net" |
| |
| "github.com/dotcloud/docker/pkg/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 = network.IP.To4() |
| firstIP = netIP.Mask(network.Mask) |
| lastIP = net.IPv4(0, 0, 0, 0).To4() |
| ) |
| |
| for i := 0; i < len(lastIP); i++ { |
| lastIP[i] = netIP[i] | ^network.Mask[i] |
| } |
| return firstIP, lastIP |
| } |
| |
| // Given a netmask, calculates the number of available hosts |
| func NetworkSize(mask net.IPMask) int32 { |
| m := net.IPv4Mask(0, 0, 0, 0) |
| for i := 0; i < net.IPv4len; i++ { |
| m[i] = ^mask[i] |
| } |
| return int32(binary.BigEndian.Uint32(m)) + 1 |
| } |
| |
| // 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(); len(ip4) == net.IPv4len { |
| 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 |
| } |