mirror of https://github.com/kubernetes/kops.git
70 lines
1.8 KiB
Go
70 lines
1.8 KiB
Go
/*
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Copyright 2019 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 subnet
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import (
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"encoding/binary"
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"fmt"
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"net"
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)
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// Overlap checks if two subnets overlap
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func Overlap(l, r *net.IPNet) bool {
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return l.Contains(r.IP) || r.Contains(l.IP)
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}
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// BelongsTo checks if child is a subnet of parent
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func BelongsTo(parent *net.IPNet, child *net.IPNet) bool {
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parentOnes, parentBits := parent.Mask.Size()
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childOnes, childBits := child.Mask.Size()
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if childBits != parentBits {
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return false
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}
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if parentOnes > childOnes {
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return false
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}
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childMasked := child.IP.Mask(parent.Mask)
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parentMasked := parent.IP.Mask(parent.Mask)
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return childMasked.Equal(parentMasked)
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}
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// SplitInto8 splits the parent IPNet into 8 subnets
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func SplitInto8(parent *net.IPNet) ([]*net.IPNet, error) {
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networkLength, _ := parent.Mask.Size()
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networkLength += 3
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var subnets []*net.IPNet
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for i := 0; i < 8; i++ {
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ip4 := parent.IP.To4()
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if ip4 != nil {
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n := binary.BigEndian.Uint32(ip4)
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n += uint32(i) << uint(32-networkLength)
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subnetIP := make(net.IP, len(ip4))
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binary.BigEndian.PutUint32(subnetIP, n)
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subnets = append(subnets, &net.IPNet{
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IP: subnetIP,
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Mask: net.CIDRMask(networkLength, 32),
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})
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} else {
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return nil, fmt.Errorf("unexpected IP address type: %s", parent)
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}
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}
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return subnets, nil
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}
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