mirror of https://github.com/k3s-io/k3s
94 lines
2.9 KiB
Go
94 lines
2.9 KiB
Go
/*
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Copyright 2017 The Kubernetes Authors.
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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 iptables
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import (
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"fmt"
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"net"
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"k8s.io/klog"
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utiliptables "k8s.io/kubernetes/pkg/util/iptables"
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utilnet "k8s.io/utils/net"
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)
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// LocalTrafficDetector in a interface to take action (jump) based on whether traffic originated locally
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// at the node or not
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type LocalTrafficDetector interface {
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// IsImplemented returns true if the implementation does something, false otherwise
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IsImplemented() bool
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// JumpIfLocal appends conditions to jump to a target chain if traffic detected to be
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// of local origin
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JumpIfLocal(args []string, toChain string) []string
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// JumpINotfLocal appends conditions to jump to a target chain if traffic detected not to be
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// of local origin
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JumpIfNotLocal(args []string, toChain string) []string
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}
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type noOpLocalDetector struct{}
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// NewNoOpLocalDetector is a no-op implementation of LocalTrafficDetector
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func NewNoOpLocalDetector() LocalTrafficDetector {
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return &noOpLocalDetector{}
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}
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func (n *noOpLocalDetector) IsImplemented() bool {
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return false
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}
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func (n *noOpLocalDetector) JumpIfLocal(args []string, toChain string) []string {
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return args // no-op
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}
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func (n *noOpLocalDetector) JumpIfNotLocal(args []string, toChain string) []string {
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return args // no-op
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}
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type detectLocalByCIDR struct {
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cidr string
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}
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// NewDetectLocalByCIDR implements the LocalTrafficDetector interface using a CIDR. This can be used when a single CIDR
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// range can be used to capture the notion of local traffic.
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func NewDetectLocalByCIDR(cidr string, ipt utiliptables.Interface) (LocalTrafficDetector, error) {
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if utilnet.IsIPv6CIDRString(cidr) != ipt.IsIpv6() {
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return nil, fmt.Errorf("CIDR %s has incorrect IP version: expect isIPv6=%t", cidr, ipt.IsIpv6())
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}
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_, _, err := net.ParseCIDR(cidr)
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if err != nil {
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return nil, err
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}
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return &detectLocalByCIDR{cidr: cidr}, nil
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}
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func (d *detectLocalByCIDR) IsImplemented() bool {
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return true
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}
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func (d *detectLocalByCIDR) JumpIfLocal(args []string, toChain string) []string {
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line := append(args, "-s", d.cidr, "-j", toChain)
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klog.V(4).Info("[DetectLocalByCIDR (", d.cidr, ")", " Jump Local: ", line)
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return line
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}
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func (d *detectLocalByCIDR) JumpIfNotLocal(args []string, toChain string) []string {
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line := append(args, "!", "-s", d.cidr, "-j", toChain)
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klog.V(4).Info("[DetectLocalByCIDR (", d.cidr, ")]", " Jump Not Local: ", line)
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return line
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}
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