diff options
Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/util/net/interface.go')
-rw-r--r-- | vendor/k8s.io/apimachinery/pkg/util/net/interface.go | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/util/net/interface.go b/vendor/k8s.io/apimachinery/pkg/util/net/interface.go new file mode 100644 index 000000000..a1e53d2e4 --- /dev/null +++ b/vendor/k8s.io/apimachinery/pkg/util/net/interface.go @@ -0,0 +1,278 @@ +/* +Copyright 2016 The Kubernetes Authors. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package net + +import ( + "bufio" + "encoding/hex" + "fmt" + "io" + "net" + "os" + + "strings" + + "github.com/golang/glog" +) + +type Route struct { + Interface string + Destination net.IP + Gateway net.IP + // TODO: add more fields here if needed +} + +func getRoutes(input io.Reader) ([]Route, error) { + routes := []Route{} + if input == nil { + return nil, fmt.Errorf("input is nil") + } + scanner := bufio.NewReader(input) + for { + line, err := scanner.ReadString('\n') + if err == io.EOF { + break + } + //ignore the headers in the route info + if strings.HasPrefix(line, "Iface") { + continue + } + fields := strings.Fields(line) + routes = append(routes, Route{}) + route := &routes[len(routes)-1] + route.Interface = fields[0] + ip, err := parseIP(fields[1]) + if err != nil { + return nil, err + } + route.Destination = ip + ip, err = parseIP(fields[2]) + if err != nil { + return nil, err + } + route.Gateway = ip + } + return routes, nil +} + +func parseIP(str string) (net.IP, error) { + if str == "" { + return nil, fmt.Errorf("input is nil") + } + bytes, err := hex.DecodeString(str) + if err != nil { + return nil, err + } + //TODO add ipv6 support + if len(bytes) != net.IPv4len { + return nil, fmt.Errorf("only IPv4 is supported") + } + bytes[0], bytes[1], bytes[2], bytes[3] = bytes[3], bytes[2], bytes[1], bytes[0] + return net.IP(bytes), nil +} + +func isInterfaceUp(intf *net.Interface) bool { + if intf == nil { + return false + } + if intf.Flags&net.FlagUp != 0 { + glog.V(4).Infof("Interface %v is up", intf.Name) + return true + } + return false +} + +//getFinalIP method receives all the IP addrs of a Interface +//and returns a nil if the address is Loopback, Ipv6, link-local or nil. +//It returns a valid IPv4 if an Ipv4 address is found in the array. +func getFinalIP(addrs []net.Addr) (net.IP, error) { + if len(addrs) > 0 { + for i := range addrs { + glog.V(4).Infof("Checking addr %s.", addrs[i].String()) + ip, _, err := net.ParseCIDR(addrs[i].String()) + if err != nil { + return nil, err + } + //Only IPv4 + //TODO : add IPv6 support + if ip.To4() != nil { + if !ip.IsLoopback() && !ip.IsLinkLocalMulticast() && !ip.IsLinkLocalUnicast() { + glog.V(4).Infof("IP found %v", ip) + return ip, nil + } else { + glog.V(4).Infof("Loopback/link-local found %v", ip) + } + } else { + glog.V(4).Infof("%v is not a valid IPv4 address", ip) + } + + } + } + return nil, nil +} + +func getIPFromInterface(intfName string, nw networkInterfacer) (net.IP, error) { + intf, err := nw.InterfaceByName(intfName) + if err != nil { + return nil, err + } + if isInterfaceUp(intf) { + addrs, err := nw.Addrs(intf) + if err != nil { + return nil, err + } + glog.V(4).Infof("Interface %q has %d addresses :%v.", intfName, len(addrs), addrs) + finalIP, err := getFinalIP(addrs) + if err != nil { + return nil, err + } + if finalIP != nil { + glog.V(4).Infof("valid IPv4 address for interface %q found as %v.", intfName, finalIP) + return finalIP, nil + } + } + + return nil, nil +} + +func flagsSet(flags net.Flags, test net.Flags) bool { + return flags&test != 0 +} + +func flagsClear(flags net.Flags, test net.Flags) bool { + return flags&test == 0 +} + +func chooseHostInterfaceNativeGo() (net.IP, error) { + intfs, err := net.Interfaces() + if err != nil { + return nil, err + } + i := 0 + var ip net.IP + for i = range intfs { + if flagsSet(intfs[i].Flags, net.FlagUp) && flagsClear(intfs[i].Flags, net.FlagLoopback|net.FlagPointToPoint) { + addrs, err := intfs[i].Addrs() + if err != nil { + return nil, err + } + if len(addrs) > 0 { + for _, addr := range addrs { + if addrIP, _, err := net.ParseCIDR(addr.String()); err == nil { + if addrIP.To4() != nil { + ip = addrIP.To4() + if !ip.IsLinkLocalMulticast() && !ip.IsLinkLocalUnicast() { + break + } + } + } + } + if ip != nil { + // This interface should suffice. + break + } + } + } + } + if ip == nil { + return nil, fmt.Errorf("no acceptable interface from host") + } + glog.V(4).Infof("Choosing interface %s (IP %v) as default", intfs[i].Name, ip) + return ip, nil +} + +//ChooseHostInterface is a method used fetch an IP for a daemon. +//It uses data from /proc/net/route file. +//For a node with no internet connection ,it returns error +//For a multi n/w interface node it returns the IP of the interface with gateway on it. +func ChooseHostInterface() (net.IP, error) { + inFile, err := os.Open("/proc/net/route") + if err != nil { + if os.IsNotExist(err) { + return chooseHostInterfaceNativeGo() + } + return nil, err + } + defer inFile.Close() + var nw networkInterfacer = networkInterface{} + return chooseHostInterfaceFromRoute(inFile, nw) +} + +type networkInterfacer interface { + InterfaceByName(intfName string) (*net.Interface, error) + Addrs(intf *net.Interface) ([]net.Addr, error) +} + +type networkInterface struct{} + +func (_ networkInterface) InterfaceByName(intfName string) (*net.Interface, error) { + intf, err := net.InterfaceByName(intfName) + if err != nil { + return nil, err + } + return intf, nil +} + +func (_ networkInterface) Addrs(intf *net.Interface) ([]net.Addr, error) { + addrs, err := intf.Addrs() + if err != nil { + return nil, err + } + return addrs, nil +} + +func chooseHostInterfaceFromRoute(inFile io.Reader, nw networkInterfacer) (net.IP, error) { + routes, err := getRoutes(inFile) + if err != nil { + return nil, err + } + zero := net.IP{0, 0, 0, 0} + var finalIP net.IP + for i := range routes { + //find interface with gateway + if routes[i].Destination.Equal(zero) { + glog.V(4).Infof("Default route transits interface %q", routes[i].Interface) + finalIP, err := getIPFromInterface(routes[i].Interface, nw) + if err != nil { + return nil, err + } + if finalIP != nil { + glog.V(4).Infof("Choosing IP %v ", finalIP) + return finalIP, nil + } + } + } + glog.V(4).Infof("No valid IP found") + if finalIP == nil { + return nil, fmt.Errorf("Unable to select an IP.") + } + return nil, nil +} + +// If bind-address is usable, return it directly +// If bind-address is not usable (unset, 0.0.0.0, or loopback), we will use the host's default +// interface. +func ChooseBindAddress(bindAddress net.IP) (net.IP, error) { + if bindAddress == nil || bindAddress.IsUnspecified() || bindAddress.IsLoopback() { + hostIP, err := ChooseHostInterface() + if err != nil { + return nil, err + } + bindAddress = hostIP + } + return bindAddress, nil +} |