forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 3
/
cidr_set.go
150 lines (127 loc) · 3.65 KB
/
cidr_set.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
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/*
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 node
import (
"encoding/binary"
"fmt"
"math/big"
"net"
"sync"
)
type cidrSet struct {
sync.Mutex
clusterCIDR *net.IPNet
clusterIP net.IP
clusterMaskSize int
maxCIDRs int
nextCandidate int
used big.Int
subNetMaskSize int
}
func newCIDRSet(clusterCIDR *net.IPNet, subNetMaskSize int) *cidrSet {
clusterMask := clusterCIDR.Mask
clusterMaskSize, _ := clusterMask.Size()
maxCIDRs := 1 << uint32(subNetMaskSize-clusterMaskSize)
return &cidrSet{
clusterCIDR: clusterCIDR,
clusterIP: clusterCIDR.IP.To4(),
clusterMaskSize: clusterMaskSize,
maxCIDRs: maxCIDRs,
subNetMaskSize: subNetMaskSize,
}
}
func (s *cidrSet) allocateNext() (*net.IPNet, error) {
s.Lock()
defer s.Unlock()
nextUnused := -1
for i := 0; i < s.maxCIDRs; i++ {
candidate := (i + s.nextCandidate) % s.maxCIDRs
if s.used.Bit(candidate) == 0 {
nextUnused = candidate
break
}
}
if nextUnused == -1 {
return nil, errCIDRRangeNoCIDRsRemaining
}
s.nextCandidate = (nextUnused + 1) % s.maxCIDRs
s.used.SetBit(&s.used, nextUnused, 1)
j := uint32(nextUnused) << uint32(32-s.subNetMaskSize)
ipInt := (binary.BigEndian.Uint32(s.clusterIP)) | j
ip := make([]byte, 4)
binary.BigEndian.PutUint32(ip, ipInt)
return &net.IPNet{
IP: ip,
Mask: net.CIDRMask(s.subNetMaskSize, 32),
}, nil
}
func (s *cidrSet) getBeginingAndEndIndices(cidr *net.IPNet) (begin, end int, err error) {
begin, end = 0, s.maxCIDRs
cidrMask := cidr.Mask
maskSize, _ := cidrMask.Size()
if !s.clusterCIDR.Contains(cidr.IP.Mask(s.clusterCIDR.Mask)) && !cidr.Contains(s.clusterCIDR.IP.Mask(cidr.Mask)) {
return -1, -1, fmt.Errorf("cidr %v is out the range of cluster cidr %v", cidr, s.clusterCIDR)
}
if s.clusterMaskSize < maskSize {
subNetMask := net.CIDRMask(s.subNetMaskSize, 32)
begin, err = s.getIndexForCIDR(&net.IPNet{
IP: cidr.IP.To4().Mask(subNetMask),
Mask: subNetMask,
})
if err != nil {
return -1, -1, err
}
ip := make([]byte, 4)
ipInt := binary.BigEndian.Uint32(cidr.IP) | (^binary.BigEndian.Uint32(cidr.Mask))
binary.BigEndian.PutUint32(ip, ipInt)
end, err = s.getIndexForCIDR(&net.IPNet{
IP: net.IP(ip).To4().Mask(subNetMask),
Mask: subNetMask,
})
if err != nil {
return -1, -1, err
}
}
return begin, end, nil
}
func (s *cidrSet) release(cidr *net.IPNet) error {
begin, end, err := s.getBeginingAndEndIndices(cidr)
if err != nil {
return err
}
s.Lock()
defer s.Unlock()
for i := begin; i <= end; i++ {
s.used.SetBit(&s.used, i, 0)
}
return nil
}
func (s *cidrSet) occupy(cidr *net.IPNet) (err error) {
begin, end, err := s.getBeginingAndEndIndices(cidr)
if err != nil {
return err
}
s.Lock()
defer s.Unlock()
for i := begin; i <= end; i++ {
s.used.SetBit(&s.used, i, 1)
}
return nil
}
func (s *cidrSet) getIndexForCIDR(cidr *net.IPNet) (int, error) {
cidrIndex := (binary.BigEndian.Uint32(s.clusterIP) ^ binary.BigEndian.Uint32(cidr.IP.To4())) >> uint32(32-s.subNetMaskSize)
if cidrIndex >= uint32(s.maxCIDRs) {
return 0, fmt.Errorf("CIDR: %v is out of the range of CIDR allocator", cidr)
}
return int(cidrIndex), nil
}