62 lines
1.4 KiB
Go
62 lines
1.4 KiB
Go
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// Copyright 2015 CNI authors
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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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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package ip
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import (
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"math/big"
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"net"
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)
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// NextIP returns IP incremented by 1
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func NextIP(ip net.IP) net.IP {
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i := ipToInt(ip)
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return intToIP(i.Add(i, big.NewInt(1)))
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}
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// PrevIP returns IP decremented by 1
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func PrevIP(ip net.IP) net.IP {
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i := ipToInt(ip)
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return intToIP(i.Sub(i, big.NewInt(1)))
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}
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// Cmp compares two IPs, returning the usual ordering:
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// a < b : -1
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// a == b : 0
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// a > b : 1
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func Cmp(a, b net.IP) int {
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aa := ipToInt(a)
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bb := ipToInt(b)
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return aa.Cmp(bb)
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}
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func ipToInt(ip net.IP) *big.Int {
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if v := ip.To4(); v != nil {
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return big.NewInt(0).SetBytes(v)
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}
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return big.NewInt(0).SetBytes(ip.To16())
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}
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func intToIP(i *big.Int) net.IP {
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return net.IP(i.Bytes())
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}
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// Network masks off the host portion of the IP
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func Network(ipn *net.IPNet) *net.IPNet {
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return &net.IPNet{
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IP: ipn.IP.Mask(ipn.Mask),
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Mask: ipn.Mask,
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}
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}
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