mirror of
https://github.com/k3s-io/kubernetes.git
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112 lines
3.4 KiB
Go
112 lines
3.4 KiB
Go
/*
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Copyright 2015 The Kubernetes Authors All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package hairpin
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import (
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"fmt"
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"io/ioutil"
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"net"
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"os"
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"path"
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"regexp"
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"strconv"
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"github.com/golang/glog"
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"k8s.io/kubernetes/pkg/util/exec"
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)
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const (
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sysfsNetPath = "/sys/devices/virtual/net"
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brportRelativePath = "brport"
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hairpinModeRelativePath = "hairpin_mode"
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hairpinEnable = "1"
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)
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var (
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ethtoolOutputRegex = regexp.MustCompile("peer_ifindex: (\\d+)")
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)
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func SetUpContainer(containerPid int, containerInterfaceName string) error {
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e := exec.New()
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return setUpContainerInternal(e, containerPid, containerInterfaceName)
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}
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func setUpContainerInternal(e exec.Interface, containerPid int, containerInterfaceName string) error {
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hostIfName, err := findPairInterfaceOfContainerInterface(e, containerPid, containerInterfaceName)
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if err != nil {
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glog.Infof("Unable to find pair interface, setting up all interfaces: %v", err)
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return setUpAllInterfaces()
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}
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return setUpInterface(hostIfName)
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}
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func findPairInterfaceOfContainerInterface(e exec.Interface, containerPid int, containerInterfaceName string) (string, error) {
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nsenterPath, err := e.LookPath("nsenter")
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if err != nil {
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return "", err
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}
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ethtoolPath, err := e.LookPath("ethtool")
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if err != nil {
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return "", err
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}
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// Get container's interface index
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output, err := e.Command(nsenterPath, "-t", fmt.Sprintf("%d", containerPid), "-n", "-F", "--", ethtoolPath, "--statistics", containerInterfaceName).CombinedOutput()
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if err != nil {
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return "", fmt.Errorf("Unable to query interface %s of container %d: %v: %s", containerInterfaceName, containerPid, err, string(output))
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}
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// look for peer_ifindex
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match := ethtoolOutputRegex.FindSubmatch(output)
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if match == nil {
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return "", fmt.Errorf("No peer_ifindex in interface statistics for %s of container %d", containerInterfaceName, containerPid)
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}
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peerIfIndex, err := strconv.Atoi(string(match[1]))
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if err != nil { // seems impossible (\d+ not numeric)
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return "", fmt.Errorf("peer_ifindex wasn't numeric: %s: %v", match[1], err)
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}
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iface, err := net.InterfaceByIndex(peerIfIndex)
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if err != nil {
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return "", err
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}
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return iface.Name, nil
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}
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func setUpAllInterfaces() error {
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interfaces, err := net.Interfaces()
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if err != nil {
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return err
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}
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for _, netIf := range interfaces {
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setUpInterface(netIf.Name) // ignore errors
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}
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return nil
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}
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func setUpInterface(ifName string) error {
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glog.V(3).Infof("Enabling hairpin on interface %s", ifName)
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ifPath := path.Join(sysfsNetPath, ifName)
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if _, err := os.Stat(ifPath); err != nil {
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return err
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}
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brportPath := path.Join(ifPath, brportRelativePath)
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if _, err := os.Stat(brportPath); err != nil && os.IsNotExist(err) {
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// Device is not on a bridge, so doesn't need hairpin mode
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return nil
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}
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hairpinModeFile := path.Join(brportPath, hairpinModeRelativePath)
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return ioutil.WriteFile(hairpinModeFile, []byte(hairpinEnable), 0644)
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}
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