Use networking to hold network related pkgs

Change names of unclear methods

Use net as pkg name for short
This commit is contained in:
Harry Zhang
2016-01-06 23:56:41 +08:00
committed by harry
parent 33c72db59c
commit 936a11e775
43 changed files with 687 additions and 626 deletions

View File

@@ -17,13 +17,8 @@ limitations under the License.
package util
import (
"bufio"
"encoding/hex"
"fmt"
"io"
"math"
"net"
"net/http"
"os"
"reflect"
"regexp"
@@ -203,249 +198,6 @@ func AllPtrFieldsNil(obj interface{}) bool {
return true
}
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
}
func GetClient(req *http.Request) string {
if userAgent, ok := req.Header["User-Agent"]; ok {
if len(userAgent) > 0 {
return userAgent[0]
}
}
return "unknown"
}
func FileExists(filename string) (bool, error) {
if _, err := os.Stat(filename); os.IsNotExist(err) {
return false, nil
@@ -486,17 +238,3 @@ func ReadDirNoExit(dirname string) ([]os.FileInfo, []error, error) {
return list, errs, 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 ValidPublicAddrForMaster(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
}