-
Notifications
You must be signed in to change notification settings - Fork 155
/
helper.go
116 lines (100 loc) · 2.94 KB
/
helper.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
/*
Copyright 2022 The Kubermatic Kubernetes Platform contributors.
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 ipam
import (
"errors"
"fmt"
"math/big"
"net"
)
var (
errIncompatiblePool = errors.New("pool is incompatible with a current cluster allocation")
)
func ipToInt(ip net.IP) (*big.Int, int) {
val := &big.Int{}
val.SetBytes([]byte(ip))
switch len(ip) {
case net.IPv4len:
return val, 32
case net.IPv6len:
return val, 128
default:
panic(fmt.Errorf("unsupported address length %d", len(ip)))
}
}
func intToIP(ipInt *big.Int, bits int) net.IP {
ipBytes := ipInt.Bytes()
ret := make([]byte, bits/8)
// Pack our IP bytes into the end of the return array,
// since big.Int.Bytes() removes front zero padding.
for i := 1; i <= len(ipBytes); i++ {
ret[len(ret)-i] = ipBytes[len(ipBytes)-i]
}
return net.IP(ret)
}
func addressRange(network *net.IPNet) (net.IP, net.IP) {
// the first IP is easy
firstIP := network.IP
// the last IP is the network address OR NOT the mask address
prefixLen, bits := network.Mask.Size()
if prefixLen == bits {
// Easy!
// But make sure that our two slices are distinct, since they
// would be in all other cases.
lastIP := make([]byte, len(firstIP))
copy(lastIP, firstIP)
return firstIP, lastIP
}
firstIPInt, bits := ipToInt(firstIP)
hostLen := uint(bits) - uint(prefixLen)
lastIPInt := big.NewInt(1)
lastIPInt.Lsh(lastIPInt, hostLen)
lastIPInt.Sub(lastIPInt, big.NewInt(1))
lastIPInt.Or(lastIPInt, firstIPInt)
return firstIP, intToIP(lastIPInt, bits)
}
func nextSubnet(network *net.IPNet, prefixLen int) (*net.IPNet, bool) {
_, currentLast := addressRange(network)
mask := net.CIDRMask(prefixLen, 8*len(currentLast))
currentSubnet := &net.IPNet{IP: currentLast.Mask(mask), Mask: mask}
_, last := addressRange(currentSubnet)
last = incIP(last)
next := &net.IPNet{IP: last.Mask(mask), Mask: mask}
if last.Equal(net.IPv4zero) || last.Equal(net.IPv6zero) {
return next, true
}
return next, false
}
func incIP(ip net.IP) net.IP {
ip = checkIPv4(ip)
incIP := make([]byte, len(ip))
copy(incIP, ip)
for j := len(incIP) - 1; j >= 0; j-- {
incIP[j]++
if incIP[j] > 0 {
break
}
}
return incIP
}
func checkIPv4(ip net.IP) net.IP {
// Go for some reason allocs IPv6len for IPv4 so we have to correct it
if v4 := ip.To4(); v4 != nil {
return v4
}
return ip
}
func isTheNextIP(ipToCheck string, previousIP string) bool {
nextIP := incIP(net.ParseIP(previousIP))
return nextIP.Equal(net.ParseIP(ipToCheck))
}