mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-11-30 02:00:19 +00:00
110 lines
4.4 KiB
Go
110 lines
4.4 KiB
Go
/*
|
|
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 conntrack
|
|
|
|
import (
|
|
"fmt"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"k8s.io/api/core/v1"
|
|
utilnet "k8s.io/kubernetes/pkg/util/net"
|
|
"k8s.io/utils/exec"
|
|
)
|
|
|
|
// Utilities for dealing with conntrack
|
|
|
|
// NoConnectionToDelete is the error string returned by conntrack when no matching connections are found
|
|
const NoConnectionToDelete = "0 flow entries have been deleted"
|
|
|
|
func protoStr(proto v1.Protocol) string {
|
|
return strings.ToLower(string(proto))
|
|
}
|
|
|
|
func parametersWithFamily(isIPv6 bool, parameters ...string) []string {
|
|
if isIPv6 {
|
|
parameters = append(parameters, "-f", "ipv6")
|
|
}
|
|
return parameters
|
|
}
|
|
|
|
// ClearEntriesForIP uses the conntrack tool to delete the conntrack entries
|
|
// for the UDP connections specified by the given service IP
|
|
func ClearEntriesForIP(execer exec.Interface, ip string, protocol v1.Protocol) error {
|
|
parameters := parametersWithFamily(utilnet.IsIPv6String(ip), "-D", "--orig-dst", ip, "-p", protoStr(protocol))
|
|
err := Exec(execer, parameters...)
|
|
if err != nil && !strings.Contains(err.Error(), NoConnectionToDelete) {
|
|
// TODO: Better handling for deletion failure. When failure occur, stale udp connection may not get flushed.
|
|
// These stale udp connection will keep black hole traffic. Making this a best effort operation for now, since it
|
|
// is expensive to baby-sit all udp connections to kubernetes services.
|
|
return fmt.Errorf("error deleting connection tracking state for UDP service IP: %s, error: %v", ip, err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Exec executes the conntrack tool using the given parameters
|
|
func Exec(execer exec.Interface, parameters ...string) error {
|
|
conntrackPath, err := execer.LookPath("conntrack")
|
|
if err != nil {
|
|
return fmt.Errorf("error looking for path of conntrack: %v", err)
|
|
}
|
|
output, err := execer.Command(conntrackPath, parameters...).CombinedOutput()
|
|
if err != nil {
|
|
return fmt.Errorf("conntrack command returned: %q, error message: %s", string(output), err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Exists returns true if conntrack binary is installed.
|
|
func Exists(execer exec.Interface) bool {
|
|
_, err := execer.LookPath("conntrack")
|
|
return err == nil
|
|
}
|
|
|
|
// ClearEntriesForPort uses the conntrack tool to delete the conntrack entries
|
|
// for connections specified by the port.
|
|
// When a packet arrives, it will not go through NAT table again, because it is not "the first" packet.
|
|
// The solution is clearing the conntrack. Known issues:
|
|
// https://github.com/docker/docker/issues/8795
|
|
// https://github.com/kubernetes/kubernetes/issues/31983
|
|
func ClearEntriesForPort(execer exec.Interface, port int, isIPv6 bool, protocol v1.Protocol) error {
|
|
if port <= 0 {
|
|
return fmt.Errorf("Wrong port number. The port number must be greater than zero")
|
|
}
|
|
parameters := parametersWithFamily(isIPv6, "-D", "-p", protoStr(protocol), "--dport", strconv.Itoa(port))
|
|
err := Exec(execer, parameters...)
|
|
if err != nil && !strings.Contains(err.Error(), NoConnectionToDelete) {
|
|
return fmt.Errorf("error deleting conntrack entries for UDP port: %d, error: %v", port, err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// ClearEntriesForNAT uses the conntrack tool to delete the conntrack entries
|
|
// for connections specified by the {origin, dest} IP pair.
|
|
func ClearEntriesForNAT(execer exec.Interface, origin, dest string, protocol v1.Protocol) error {
|
|
parameters := parametersWithFamily(utilnet.IsIPv6String(origin), "-D", "--orig-dst", origin, "--dst-nat", dest,
|
|
"-p", protoStr(protocol))
|
|
err := Exec(execer, parameters...)
|
|
if err != nil && !strings.Contains(err.Error(), NoConnectionToDelete) {
|
|
// TODO: Better handling for deletion failure. When failure occur, stale udp connection may not get flushed.
|
|
// These stale udp connection will keep black hole traffic. Making this a best effort operation for now, since it
|
|
// is expensive to baby sit all udp connections to kubernetes services.
|
|
return fmt.Errorf("error deleting conntrack entries for UDP peer {%s, %s}, error: %v", origin, dest, err)
|
|
}
|
|
return nil
|
|
}
|