forked from networkservicemesh/networkservicemesh
-
Notifications
You must be signed in to change notification settings - Fork 12
/
prefixpool.go
642 lines (566 loc) · 17.5 KB
/
prefixpool.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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
package prefix_pool
import (
"math/big"
"net"
"sort"
"sync"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"github.com/networkservicemesh/networkservicemesh/controlplane/api/connectioncontext"
)
/**
All in one interface for managing prefixes.
*/
type PrefixPool interface {
/*
Process ExtraPrefixesRequest and provide a list of prefixes for clients to use.
*/
Extract(connectionId string, family connectioncontext.IpFamily_Family, requests ...*connectioncontext.ExtraPrefixRequest) (srcIP *net.IPNet, dstIP *net.IPNet, requested []string, err error)
Release(connectionId string) error
GetConnectionInformation(connectionId string) (string, []string, error)
GetPrefixes() []string
Intersect(prefix string) (bool, error)
ExcludePrefixes(excludedPrefixes []string) ([]string, error)
ReleaseExcludedPrefixes(excludedPrefixes []string) error
}
type prefixPool struct {
sync.RWMutex
basePrefixes []string // Just to know where we start from
prefixes []string
connections map[string]*connectionRecord
}
func (impl *prefixPool) GetPrefixes() []string {
return impl.prefixes
}
type connectionRecord struct {
ipNet *net.IPNet
prefixes []string
}
func NewPrefixPool(prefixes ...string) (PrefixPool, error) {
//TODO: Add validation of input prefixes.
return &prefixPool{
basePrefixes: prefixes,
prefixes: prefixes,
connections: map[string]*connectionRecord{},
}, nil
}
/* Release excluded prefixes back the pool of available ones */
func (impl *prefixPool) ReleaseExcludedPrefixes(excludedPrefixes []string) error {
impl.Lock()
defer impl.Unlock()
remaining, err := ReleasePrefixes(impl.prefixes, excludedPrefixes...)
if err != nil {
return err
}
/* Sort the prefixes, so their order is consistent during unit testing */
sort.Slice(remaining, func(i, j int) bool { return remaining[i] < remaining[j] })
impl.prefixes = remaining
return nil
}
/* Exclude prefixes from the pool of available prefixes */
func (impl *prefixPool) ExcludePrefixes(excludedPrefixes []string) ([]string, error) {
impl.Lock()
defer impl.Unlock()
/* Use a working copy for the available prefixes */
copyPrefixes := append([]string{}, impl.prefixes...)
removedPrefixes := []string{}
for _, excludedPrefix := range excludedPrefixes {
splittedEntries := []string{}
prefixesToRemove := []string{}
_, subnetExclude, _ := net.ParseCIDR(excludedPrefix)
/* 1. Check if each excluded entry overlaps with the available prefix */
for _, prefix := range copyPrefixes {
intersecting := false
excludedIsBigger := false
_, subnetPrefix, _ := net.ParseCIDR(prefix)
intersecting, excludedIsBigger = intersect(subnetExclude, subnetPrefix)
/* 1.1. If intersecting, check which one is bigger */
if intersecting {
/* 1.1.1. If excluded is bigger, we remove the original entry */
if !excludedIsBigger {
/* 1.1.2. If the original entry is bigger, we split it and remove the avoided range */
res, err := extractSubnet(subnetPrefix, subnetExclude)
if err != nil {
return nil, err
}
/* 1.1.3. Collect the resulted split prefixes */
splittedEntries = append(splittedEntries, res...)
/* 1.1.5. Collect the actual excluded prefixes that should be added back to the original pool */
removedPrefixes = append(removedPrefixes, subnetExclude.String())
} else {
/* 1.1.5. Collect the actual excluded prefixes that should be added back to the original pool */
removedPrefixes = append(removedPrefixes, subnetPrefix.String())
}
/* 1.1.4. Collect prefixes that should be removed from the original pool */
prefixesToRemove = append(prefixesToRemove, subnetPrefix.String())
break
}
/* 1.2. If not intersecting, proceed verifying the next one */
}
/* 2. Keep only the prefixes that should not be removed from the original pool */
if len(prefixesToRemove) != 0 {
for _, presentPrefix := range copyPrefixes {
prefixFound := false
for _, prefixToRemove := range prefixesToRemove {
if presentPrefix == prefixToRemove {
prefixFound = true
break
}
}
if !prefixFound {
/* 2.1. Add the original non-split prefixes to the split ones */
splittedEntries = append(splittedEntries, presentPrefix)
}
}
/* 2.2. Update the original prefix list */
copyPrefixes = splittedEntries
}
}
/* Raise an error, if there aren't any available prefixes left after excluding */
if len(copyPrefixes) == 0 {
err := errors.New("IPAM: The available address pool is empty, probably intersected by excludedPrefix")
logrus.Errorf("%v", err)
return nil, err
}
/* Everything should be fine, update the available prefixes with what's left */
impl.prefixes = copyPrefixes
return removedPrefixes, nil
}
/* Split the wider range removing the avoided smaller range from it */
func extractSubnet(wider, smaller *net.IPNet) ([]string, error) {
root := wider
prefixLen, _ := smaller.Mask.Size()
leftParts, rightParts := []string{}, []string{}
for {
rootLen, _ := root.Mask.Size()
if rootLen == prefixLen {
// we found the required prefix
break
}
sub1, err := subnet(root, 0)
if err != nil {
return nil, err
}
sub2, err := subnet(root, 1)
if err != nil {
return nil, err
}
if sub1.Contains(smaller.IP) {
rightParts = append(rightParts, sub2.String())
root = sub1
} else if sub2.Contains(smaller.IP) {
leftParts = append(leftParts, sub1.String())
root = sub2
} else {
return nil, errors.New("split failed")
}
}
return append(leftParts, rightParts...), nil
}
func (impl *prefixPool) Extract(connectionId string, family connectioncontext.IpFamily_Family, requests ...*connectioncontext.ExtraPrefixRequest) (srcIP *net.IPNet, dstIP *net.IPNet, requested []string, err error) {
impl.Lock()
defer impl.Unlock()
prefixLen := 30 // At lest 4 addresses
if family == connectioncontext.IpFamily_IPV6 {
prefixLen = 126
}
result, remaining, err := ExtractPrefixes(impl.prefixes, &connectioncontext.ExtraPrefixRequest{
RequiredNumber: 1,
RequestedNumber: 1,
PrefixLen: uint32(prefixLen),
AddrFamily: &connectioncontext.IpFamily{Family: family},
})
if err != nil {
return nil, nil, nil, err
}
ip, ipNet, err := net.ParseCIDR(result[0])
if err != nil {
return nil, nil, nil, err
}
src, err := IncrementIP(ip, ipNet)
if err != nil {
return nil, nil, nil, err
}
dst, err := IncrementIP(src, ipNet)
if err != nil {
return nil, nil, nil, err
}
if len(requests) > 0 {
requested, remaining, err = ExtractPrefixes(remaining, requests...)
if err != nil {
return nil, nil, nil, err
}
}
impl.prefixes = remaining
impl.connections[connectionId] = &connectionRecord{
ipNet: ipNet,
prefixes: requested,
}
return &net.IPNet{IP: src, Mask: ipNet.Mask}, &net.IPNet{IP: dst, Mask: ipNet.Mask}, requested, nil
}
func (impl *prefixPool) Release(connectionId string) error {
impl.Lock()
defer impl.Unlock()
conn := impl.connections[connectionId]
if conn == nil {
return errors.Errorf("Failed to release connection infomration: %s", connectionId)
}
delete(impl.connections, connectionId)
remaining, err := ReleasePrefixes(impl.prefixes, conn.prefixes...)
if err != nil {
return err
}
remaining, err = ReleasePrefixes(remaining, conn.ipNet.String())
if err != nil {
return err
}
impl.prefixes = remaining
return nil
}
func (impl *prefixPool) GetConnectionInformation(connectionId string) (string, []string, error) {
impl.RLock()
defer impl.RUnlock()
conn := impl.connections[connectionId]
if conn == nil {
return "", nil, errors.Errorf("No connection with id: %s is found", connectionId)
}
return conn.ipNet.String(), conn.prefixes, nil
}
func (impl *prefixPool) Intersect(prefix string) (bool, error) {
_, subnet, err := net.ParseCIDR(prefix)
if err != nil {
return false, err
}
for _, p := range impl.prefixes {
_, sn, _ := net.ParseCIDR(p)
if ret, _ := intersect(sn, subnet); ret {
return true, nil
}
}
return false, nil
}
func intersect(first, second *net.IPNet) (bool, bool) {
f, _ := first.Mask.Size()
s, _ := second.Mask.Size()
firstIsBigger := false
var widerRange, narrowerRange *net.IPNet
if f < s {
widerRange, narrowerRange = first, second
firstIsBigger = true
} else {
widerRange, narrowerRange = second, first
}
return widerRange.Contains(narrowerRange.IP), firstIsBigger
}
func ExtractPrefixes(prefixes []string, requests ...*connectioncontext.ExtraPrefixRequest) (requested []string, remaining []string, err error) {
// Check if requests are valid.
for _, request := range requests {
err := request.IsValid()
if err != nil {
return nil, prefixes, err
}
}
//1 find prefix of desired prefix len and return it
result := []string{}
// Make a copy since we need to fit all prefixes before we could finish.
newPrefixes := []string{}
newPrefixes = append(newPrefixes, prefixes...)
// We need to firstly find required prefixes available.
for _, request := range requests {
for i := uint32(0); i < request.RequiredNumber; i++ {
prefix, leftPrefixes, err := ExtractPrefix(newPrefixes, request.PrefixLen)
if err != nil {
return nil, prefixes, err
}
result = append(result, prefix)
newPrefixes = leftPrefixes
}
}
// We need to fit some more prefies up to Requested ones
for _, request := range requests {
for i := request.RequiredNumber; i < request.RequestedNumber; i++ {
prefix, leftPrefixes, err := ExtractPrefix(newPrefixes, request.PrefixLen)
if err != nil {
// It seems there is no more prefixes available, but since we have all Required already we could go.
break
}
result = append(result, prefix)
newPrefixes = leftPrefixes
}
}
if len(result) == 0 {
return nil, prefixes, errors.Errorf("Failed to extract prefixes, there is no available %v", prefixes)
}
return result, newPrefixes, nil
}
func ExtractPrefix(prefixes []string, prefixLen uint32) (string, []string, error) {
// Check if we already have required CIDR
max_prefix := 0
max_prefix_idx := -1
// Check if we already have required prefix,
for idx, prefix := range prefixes {
_, netip, err := net.ParseCIDR(prefix)
if err != nil {
continue
}
parentLen, _ := netip.Mask.Size()
// Check if some of requests are fit into this prefix.
if prefixLen == uint32(parentLen) {
// We found required one.
resultPrefix := prefixes[idx]
resultPrefixes := append(prefixes[:idx], prefixes[idx+1:]...)
// Lets remove from list and return
return resultPrefix, resultPrefixes, nil
} else {
// Update minimal root for split
if uint32(parentLen) < prefixLen && (parentLen > max_prefix || max_prefix == 0) {
max_prefix = parentLen
max_prefix_idx = idx
}
}
}
// Not found, lets split minimal found prefix
if max_prefix_idx == -1 {
// There is no room to split
return "", prefixes, errors.Errorf("Failed to find room to have prefix len %d at %v", prefixLen, prefixes)
}
resultPrefixRoot := prefixes[max_prefix_idx]
right_parts := []string{}
_, rootCIDRNet, _ := net.ParseCIDR(resultPrefixRoot)
for {
rootLen, _ := rootCIDRNet.Mask.Size()
if uint32(rootLen) == prefixLen {
// we found required prefix
break
}
sub1, err := subnet(rootCIDRNet, 0)
if err != nil {
return "", prefixes, err
}
sub2, err := subnet(rootCIDRNet, 1)
if err != nil {
return "", prefixes, err
}
right_parts = append(right_parts, sub2.String())
rootCIDRNet = sub1
}
var resultPrefixes []string = nil
resultPrefixes = append(resultPrefixes, prefixes[:max_prefix_idx]...)
resultPrefixes = append(resultPrefixes, reverse(right_parts)...)
resultPrefixes = append(resultPrefixes, prefixes[max_prefix_idx+1:]...)
// return result
return rootCIDRNet.String(), resultPrefixes, nil
}
func removeDuplicates(elements []string) []string {
encountered := map[string]bool{}
result := []string{}
for v := range elements {
if !encountered[elements[v]] {
encountered[elements[v]] = true
result = append(result, elements[v])
}
}
return result
}
func reverse(values []string) []string {
newValues := make([]string, len(values))
for i, j := 0, len(values)-1; i <= j; i, j = i+1, j-1 {
newValues[i] = values[j]
if i != j {
newValues[j] = values[i]
}
}
return newValues
}
func ReleasePrefixes(prefixes []string, released ...string) (remaining []string, err error) {
result := []string{}
if len(released) == 0 {
return prefixes, nil
}
result = removeDuplicates(append(prefixes, released...))
prefixByPrefixLen := map[int][]*net.IPNet{}
for _, prefix := range result {
_, ipnet, err := net.ParseCIDR(prefix)
if err != nil {
return nil, err
}
parentLen, _ := ipnet.Mask.Size()
nets := prefixByPrefixLen[parentLen]
nets = append(nets, ipnet)
prefixByPrefixLen[parentLen] = nets
}
for {
newPrefixByPrefixLen := map[int][]*net.IPNet{}
changes := 0
for basePrefix, value := range prefixByPrefixLen {
base := map[string]*net.IPNet{}
cvalue := append(newPrefixByPrefixLen[basePrefix], value...)
parentPrefix := []*net.IPNet{}
if len(cvalue) < 2 {
newPrefixByPrefixLen[basePrefix] = cvalue
continue
}
for _, netValue := range cvalue {
baseIp := &net.IPNet{
IP: clearNetIndexInIP(netValue.IP, basePrefix),
Mask: netValue.Mask,
}
parentLen, addrLen := baseIp.Mask.Size()
bv := base[baseIp.String()]
if bv == nil {
base[baseIp.String()] = netValue
} else {
// We found item with same base IP, we we could join this two networks into one.
// Remove from current level
delete(base, baseIp.String())
// And put to next level
parentPrefix = append(parentPrefix, &net.IPNet{
IP: baseIp.IP,
Mask: net.CIDRMask(parentLen-1, addrLen),
})
changes++
}
}
leftPrefixes := []*net.IPNet{}
// Put all not merged values
for _, value := range base {
leftPrefixes = append(leftPrefixes, value)
}
newPrefixByPrefixLen[basePrefix] = leftPrefixes
newPrefixByPrefixLen[basePrefix-1] = append(newPrefixByPrefixLen[basePrefix-1], parentPrefix...)
}
if changes == 0 {
// All is merged, we could exit
result = []string{}
for _, value := range newPrefixByPrefixLen {
for _, v := range value {
result = append(result, v.String())
}
}
return result, nil
}
prefixByPrefixLen = newPrefixByPrefixLen
}
}
func subnet(ipnet *net.IPNet, subnet_index int) (*net.IPNet, error) {
mask := ipnet.Mask
parentLen, addrLen := mask.Size()
newPrefixLen := parentLen + 1
if newPrefixLen > addrLen {
return nil, errors.Errorf("insufficient address space to extend prefix of %d", parentLen)
}
if uint64(subnet_index) > 2 {
return nil, errors.Errorf("prefix extension does not accommodate a subnet numbered %d", subnet_index)
}
return &net.IPNet{
IP: setNetIndexInIP(ipnet.IP, subnet_index, newPrefixLen),
Mask: net.CIDRMask(newPrefixLen, addrLen),
}, nil
}
func AddressCount(prefixes ...string) uint64 {
var c uint64 = 0
for _, pr := range prefixes {
c += addressCount(pr)
}
return c
}
func addressCount(pr string) uint64 {
_, network, _ := net.ParseCIDR(pr)
prefixLen, bits := network.Mask.Size()
return 1 << (uint64(bits) - uint64(prefixLen))
}
func setNetIndexInIP(ip net.IP, num int, prefixLen int) net.IP {
ipInt, totalBits := fromIP(ip)
bigNum := big.NewInt(int64(num))
bigNum.Lsh(bigNum, uint(totalBits-prefixLen))
ipInt.Or(ipInt, bigNum)
return toIP(ipInt, totalBits)
}
func clearNetIndexInIP(ip net.IP, prefixLen int) net.IP {
ipInt, totalBits := fromIP(ip)
ipInt.SetBit(ipInt, totalBits-prefixLen, 0)
return toIP(ipInt, totalBits)
}
func toIP(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 fromIP(ip net.IP) (*big.Int, int) {
val := &big.Int{}
val.SetBytes([]byte(ip))
i := len(ip)
if i == net.IPv4len {
return val, 32
} // else if i == net.IPv6len
return val, 128
}
func min(a, b int) int {
if a < b {
return a
}
return b
}
func MaxCommonPrefixSubnet(s1, s2 *net.IPNet) *net.IPNet {
rawIp1, n1 := fromIP(s1.IP)
rawIp2, _ := fromIP(s2.IP)
xored := &big.Int{}
xored.Xor(rawIp1, rawIp2)
maskSize := leadingZeros(xored, n1)
m1, bits := s1.Mask.Size()
m2, _ := s2.Mask.Size()
mask := net.CIDRMask(min(min(m1, m2), maskSize), bits)
return &net.IPNet{
IP: s1.IP.Mask(mask),
Mask: mask,
}
}
func IpToNet(ipAddr net.IP) *net.IPNet {
mask := net.CIDRMask(len(ipAddr)*8, len(ipAddr)*8)
return &net.IPNet{IP: ipAddr, Mask: mask}
}
func leadingZeros(n *big.Int, size int) int {
i := size - 1
for ; n.Bit(i) == 0 && i > 0; i-- {
}
return size - 1 - i
}
/**
AddressRange returns the first and last addresses in the given CIDR range.
*/
func AddressRange(network *net.IPNet) (net.IP, net.IP) {
firstIP := network.IP
// the last IP is the network address OR NOT the mask address
prefixLen, bits := network.Mask.Size()
if prefixLen == bits {
lastIP := make([]byte, len(firstIP))
copy(lastIP, firstIP)
return firstIP, lastIP
}
firstIPInt, bits := fromIP(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, toIP(lastIPInt, bits)
}
func IncrementIP(sourceIp net.IP, ipNet *net.IPNet) (net.IP, error) {
ip := make([]byte, len(sourceIp))
copy(ip, sourceIp)
for i := len(ip) - 1; i >= 0; i-- {
ip[i]++
if ip[i] != 0 {
break
}
}
if !ipNet.Contains(ip) {
return nil, errors.Errorf("Overflowed CIDR while incrementing IP")
}
return ip, nil
}