aboutsummaryrefslogtreecommitdiffstats
path: root/src/plugins/acl/hash_lookup.c
blob: f16f7b2fd59a3aa52f5a6b368ae170fbc05a749c (plain)
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
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
/*
 *------------------------------------------------------------------
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * 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.
 *------------------------------------------------------------------
 */

#include <stddef.h>
#include <netinet/in.h>

#include <vlibapi/api.h>
#include <vlibmemory/api.h>

#include <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/pg/pg.h>
#include <vppinfra/error.h>
#include <vnet/plugin/plugin.h>
#include <acl/acl.h>
#include <vppinfra/bihash_48_8.h>

#include "hash_lookup.h"
#include "hash_lookup_private.h"


always_inline applied_hash_ace_entry_t **get_applied_hash_aces(acl_main_t *am, u32 lc_index)
{
  applied_hash_ace_entry_t **applied_hash_aces = vec_elt_at_index(am->hash_entry_vec_by_lc_index, lc_index);

/*is_input ? vec_elt_at_index(am->input_hash_entry_vec_by_sw_if_index, sw_if_index)
                                                          : vec_elt_at_index(am->output_hash_entry_vec_by_sw_if_index, sw_if_index);
*/
  return applied_hash_aces;
}


static void
hashtable_add_del(acl_main_t *am, clib_bihash_kv_48_8_t *kv, int is_add)
{
    DBG("HASH ADD/DEL: %016llx %016llx %016llx %016llx %016llx %016llx %016llx add %d",
                        kv->key[0], kv->key[1], kv->key[2],
                        kv->key[3], kv->key[4], kv->key[5], kv->value, is_add);
    BV (clib_bihash_add_del) (&am->acl_lookup_hash, kv, is_add);
}

/*
 * TupleMerge
 *
 * Initial adaptation by Valerio Bruschi (valerio.bruschi@telecom-paristech.fr)
 * based on the TupleMerge [1] simulator kindly made available
 * by  James Daly (dalyjamese@gmail.com) and  Eric Torng (torng@cse.msu.edu)
 * ( http://www.cse.msu.edu/~dalyjame/ or http://www.cse.msu.edu/~torng/ ),
 * refactoring by Andrew Yourtchenko.
 *
 * [1] James Daly, Eric Torng "TupleMerge: Building Online Packet Classifiers
 * by Omitting Bits", In Proc. IEEE ICCCN 2017, pp. 1-10
 *
 */

static int
count_bits (u64 word)
{
  int counter = 0;
  while (word)
    {
      counter += word & 1;
      word >>= 1;
    }
  return counter;
}

/* check if mask2 can be contained by mask1 */
static u8
first_mask_contains_second_mask(int is_ip6, fa_5tuple_t * mask1, fa_5tuple_t * mask2)
{
  int i;
  if (is_ip6)
    {
      for (i = 0; i < 2; i++)
        {
          if ((mask1->ip6_addr[0].as_u64[i] & mask2->ip6_addr[0].as_u64[i]) !=
              mask1->ip6_addr[0].as_u64[i])
            return 0;
          if ((mask1->ip6_addr[1].as_u64[i] & mask2->ip6_addr[1].as_u64[i]) !=
              mask1->ip6_addr[1].as_u64[i])
            return 0;
        }
    }
  else
    {
      /* check the pads, both masks must have it 0 */
      u32 padcheck = 0;
      int i;
      for (i=0; i<6; i++) {
        padcheck |= mask1->l3_zero_pad[i];
        padcheck |= mask2->l3_zero_pad[i];
      }
      if (padcheck != 0)
        return 0;
      if ((mask1->ip4_addr[0].as_u32 & mask2->ip4_addr[0].as_u32) !=
          mask1->ip4_addr[0].as_u32)
        return 0;
      if ((mask1->ip4_addr[1].as_u32 & mask2->ip4_addr[1].as_u32) !=
          mask1->ip4_addr[1].as_u32)
        return 0;
    }

  /* take care if port are not exact-match  */
  if ((mask1->l4.as_u64 & mask2->l4.as_u64) != mask1->l4.as_u64)
    return 0;

  if ((mask1->pkt.as_u64 & mask2->pkt.as_u64) != mask1->pkt.as_u64)
    return 0;

  return 1;
}



/*
 * TupleMerge:
 *
 * Consider the situation when we have to create a new table
 * T for a given rule R. This occurs for the first rule inserted and
 * for later rules if it is incompatible with all existing tables.
 * In this event, we need to determine mT for a new table.
 * Setting mT = mR is not a good strategy; if another similar,
 * but slightly less specific, rule appears we will be unable to
 * add it to T and will thus have to create another new table. We
 * thus consider two factors: is the rule more strongly aligned
 * with source or destination addresses (usually the two most
 * important fields) and how much slack needs to be given to
 * allow for other rules. If the source and destination addresses
 * are close together (within 4 bits for our experiments), we use
 * both of them. Otherwise, we drop the smaller (less specific)
 * address and its associated port field from consideration; R is
 * predominantly aligned with one of the two fields and should
 * be grouped with other similar rules. This is similar to TSS
 * dropping port fields, but since it is based on observable rule
 * characteristics it is more likely to keep important fields and
 * discard less useful ones.
 * We then look at the absolute lengths of the addresses. If
 * the address is long, we are more likely to try to add shorter
 * lengths and likewise the reverse. We thus remove a few bits
 * from both address fields with more bits removed from longer
 * addresses. For 32 bit addresses, we remove 4 bits, 3 for more
 * than 24, 2 for more than 16, and so on (so 8 and fewer bits
 * don’t have any removed). We only do this for prefix fields like
 * addresses; both range fields (like ports) and exact match fields
 * (like protocol) should remain as they are.
 */


static u32
shift_ip4_if(u32 mask, u32 thresh, int numshifts, u32 else_val)
{
  if (mask > thresh)
     return clib_host_to_net_u32((clib_net_to_host_u32(mask) << numshifts) & 0xFFFFFFFF);
  else
     return else_val;
}

static void
relax_ip4_addr(ip4_address_t *ip4_mask, int relax2) {
  int shifts_per_relax[2][4] = { { 6, 5, 4, 2 }, { 3, 2, 1, 1 } };

  int *shifts = shifts_per_relax[relax2];
  if(ip4_mask->as_u32 == 0xffffffff)
    ip4_mask->as_u32 = clib_host_to_net_u32((clib_net_to_host_u32(ip4_mask->as_u32) << shifts[0])&0xFFFFFFFF);
  else
    ip4_mask->as_u32 = shift_ip4_if(ip4_mask->as_u32, 0xffffff00, shifts[1],
                        shift_ip4_if(ip4_mask->as_u32, 0xffff0000, shifts[2],
                          shift_ip4_if(ip4_mask->as_u32, 0xff000000, shifts[3], ip4_mask->as_u32)));
}

static void
relax_ip6_addr(ip6_address_t *ip6_mask, int relax2) {
  /*
   * This "better than nothing" relax logic is based on heuristics
   * from IPv6 knowledge, and may not be optimal.
   * Some further tuning may be needed in the future.
   */
  if (ip6_mask->as_u64[0] == 0xffffffffffffffffULL) {
    if (ip6_mask->as_u64[1] == 0xffffffffffffffffULL) {
      /* relax a /128 down to /64  - likely to have more hosts */
      ip6_mask->as_u64[1] = 0;
    } else if (ip6_mask->as_u64[1] == 0) {
      /* relax a /64 down to /56 - likely to have more subnets */
      ip6_mask->as_u64[0] = clib_host_to_net_u64(0xffffffffffffff00ULL);
    }
  }
}

static void
relax_tuple(fa_5tuple_t *mask, int is_ip6, int relax2){
	fa_5tuple_t save_mask = *mask;

	int counter_s = 0, counter_d = 0;
        if (is_ip6) {
	  int i;
	  for(i=0; i<2; i++){
		counter_s += count_bits(mask->ip6_addr[0].as_u64[i]);
		counter_d += count_bits(mask->ip6_addr[1].as_u64[i]);
	  }
        } else {
		counter_s += count_bits(mask->ip4_addr[0].as_u32);
		counter_d += count_bits(mask->ip4_addr[1].as_u32);
        }

/*
 * is the rule more strongly aligned with source or destination addresses
 * (usually the two most important fields) and how much slack needs to be
 * given to allow for other rules. If the source and destination addresses
 * are close together (within 4 bits for our experiments), we use both of them.
 * Otherwise, we drop the smaller (less specific) address and its associated
 * port field from consideration
 */
	const int deltaThreshold = 4;
	/* const int deltaThreshold = 8; if IPV6? */
	int delta = counter_s - counter_d;
	if (-delta > deltaThreshold) {
                if (is_ip6)
		  mask->ip6_addr[0].as_u64[1] = mask->ip6_addr[0].as_u64[0] = 0;
                else
		  mask->ip4_addr[0].as_u32 = 0;
		mask->l4.port[0] = 0;
        } else if (delta > deltaThreshold) {
                if (is_ip6)
		  mask->ip6_addr[1].as_u64[1] = mask->ip6_addr[1].as_u64[0] = 0;
                else
		  mask->ip4_addr[1].as_u32 = 0;
		mask->l4.port[1] = 0;
        }

        if (is_ip6) {
          relax_ip6_addr(&mask->ip6_addr[0], relax2);
          relax_ip6_addr(&mask->ip6_addr[1], relax2);
        } else {
          relax_ip4_addr(&mask->ip4_addr[0], relax2);
          relax_ip4_addr(&mask->ip4_addr[1], relax2);
        }
	mask->pkt.is_nonfirst_fragment = 0;
	mask->pkt.l4_valid = 0;
	if(!first_mask_contains_second_mask(is_ip6, mask, &save_mask)){
		DBG( "TM-relaxing-ERROR");
                *mask = save_mask;
	}
	DBG( "TM-relaxing-end");
}


static u32
tm_assign_mask_type_index(acl_main_t *am, fa_5tuple_t *mask, int is_ip6, u32 lc_index)
{
	u32 mask_type_index = ~0;
	u32 for_mask_type_index = ~0;
	ace_mask_type_entry_t *mte;
	int order_index;
	/* look for existing mask comparable with the one in input */

	hash_applied_mask_info_t **hash_applied_mask_info_vec = vec_elt_at_index(am->hash_applied_mask_info_vec_by_lc_index, lc_index);
	hash_applied_mask_info_t *minfo;

        if (vec_len(*hash_applied_mask_info_vec) > 0) {
	    for(order_index = vec_len((*hash_applied_mask_info_vec)) -1; order_index >= 0; order_index--) {
		minfo = vec_elt_at_index((*hash_applied_mask_info_vec), order_index);
		for_mask_type_index = minfo->mask_type_index;
		mte = vec_elt_at_index(am->ace_mask_type_pool, for_mask_type_index);
		if(first_mask_contains_second_mask(is_ip6, &mte->mask, mask)){
			mask_type_index = (mte - am->ace_mask_type_pool);
			break;
		}
            }
	}

	if(~0 == mask_type_index) {
		/* if no mask is found, then let's use a relaxed version of the original one, in order to be used by new ace_entries */
		DBG( "TM-assigning mask type index-new one");
		pool_get_aligned (am->ace_mask_type_pool, mte, CLIB_CACHE_LINE_BYTES);
		mask_type_index = mte - am->ace_mask_type_pool;

		hash_applied_mask_info_t **hash_applied_mask_info_vec = vec_elt_at_index(am->hash_applied_mask_info_vec_by_lc_index, lc_index);

		int spot = vec_len((*hash_applied_mask_info_vec));
		vec_validate((*hash_applied_mask_info_vec), spot);
		minfo = vec_elt_at_index((*hash_applied_mask_info_vec), spot);
		minfo->mask_type_index = mask_type_index;
		minfo->num_entries = 0;
		minfo->max_collisions = 0;
		minfo->first_rule_index = ~0;

		clib_memcpy(&mte->mask, mask, sizeof(mte->mask));
		relax_tuple(&mte->mask, is_ip6, 0);

		mte->refcount = 0;
		/*
		 * We can use only 16 bits, since in the match there is only u16 field.
		 * Realistically, once you go to 64K of mask types, it is a huge
		 * problem anyway, so we might as well stop half way.
		 */
		ASSERT(mask_type_index < 32768);
	}
	mte = am->ace_mask_type_pool + mask_type_index;
	mte->refcount++;
	return mask_type_index;
}


static void
fill_applied_hash_ace_kv(acl_main_t *am,
                            applied_hash_ace_entry_t **applied_hash_aces,
                            u32 lc_index,
                            u32 new_index, clib_bihash_kv_48_8_t *kv)
{
  fa_5tuple_t *kv_key = (fa_5tuple_t *)kv->key;
  hash_acl_lookup_value_t *kv_val = (hash_acl_lookup_value_t *)&kv->value;
  applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), new_index);
  hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, pae->acl_index);

  /* apply the mask to ace key */
  hash_ace_info_t *ace_info = vec_elt_at_index(ha->rules, pae->hash_ace_info_index);
  ace_mask_type_entry_t *mte = vec_elt_at_index(am->ace_mask_type_pool, pae->mask_type_index);

  u64 *pmatch = (u64 *) &ace_info->match;
  u64 *pmask = (u64 *)&mte->mask;
  u64 *pkey = (u64 *)kv->key;

  *pkey++ = *pmatch++ & *pmask++;
  *pkey++ = *pmatch++ & *pmask++;
  *pkey++ = *pmatch++ & *pmask++;
  *pkey++ = *pmatch++ & *pmask++;
  *pkey++ = *pmatch++ & *pmask++;
  *pkey++ = *pmatch++ & *pmask++;

  kv_key->pkt.mask_type_index_lsb = pae->mask_type_index;
  kv_key->pkt.lc_index = lc_index;
  kv_val->as_u64 = 0;
  kv_val->applied_entry_index = new_index;
}

static void
add_del_hashtable_entry(acl_main_t *am,
                            u32 lc_index,
                            applied_hash_ace_entry_t **applied_hash_aces,
			    u32 index, int is_add)
{
  clib_bihash_kv_48_8_t kv;

  fill_applied_hash_ace_kv(am, applied_hash_aces, lc_index, index, &kv);
  hashtable_add_del(am, &kv, is_add);
}


static u32
find_mask_type_index(acl_main_t *am, fa_5tuple_t *mask)
{
  ace_mask_type_entry_t *mte;
  /* *INDENT-OFF* */
  pool_foreach(mte, am->ace_mask_type_pool,
  ({
    if(memcmp(&mte->mask, mask, sizeof(*mask)) == 0)
      return (mte - am->ace_mask_type_pool);
  }));
  /* *INDENT-ON* */
  return ~0;
}

static u32
assign_mask_type_index(acl_main_t *am, fa_5tuple_t *mask)
{
  u32 mask_type_index = find_mask_type_index(am, mask);
  ace_mask_type_entry_t *mte;
  if(~0 == mask_type_index) {
    pool_get_aligned (am->ace_mask_type_pool, mte, CLIB_CACHE_LINE_BYTES);
    mask_type_index = mte - am->ace_mask_type_pool;
    clib_memcpy(&mte->mask, mask, sizeof(mte->mask));
    mte->refcount = 0;
    /*
     * We can use only 16 bits, since in the match there is only u16 field.
     * Realistically, once you go to 64K of mask types, it is a huge
     * problem anyway, so we might as well stop half way.
     */
    ASSERT(mask_type_index < 32768);
  }
  mte = am->ace_mask_type_pool + mask_type_index;
  mte->refcount++;
  return mask_type_index;
}

static void
release_mask_type_index(acl_main_t *am, u32 mask_type_index)
{
  ace_mask_type_entry_t *mte = pool_elt_at_index(am->ace_mask_type_pool, mask_type_index);
  mte->refcount--;
  if (mte->refcount == 0) {
    /* we are not using this entry anymore */
    pool_put(am->ace_mask_type_pool, mte);
  }
}

static void
remake_hash_applied_mask_info_vec (acl_main_t * am,
                                   applied_hash_ace_entry_t **
                                   applied_hash_aces, u32 lc_index)
{
  hash_applied_mask_info_t *new_hash_applied_mask_info_vec =
    vec_new (hash_applied_mask_info_t, 0);

  hash_applied_mask_info_t *minfo;
  int i;
  for (i = 0; i < vec_len ((*applied_hash_aces)); i++)
    {
      applied_hash_ace_entry_t *pae =
        vec_elt_at_index ((*applied_hash_aces), i);

      /* check if mask_type_index is already there */
      u32 new_pointer = vec_len (new_hash_applied_mask_info_vec);
      int search;
      for (search = 0; search < vec_len (new_hash_applied_mask_info_vec);
           search++)
        {
          minfo = vec_elt_at_index (new_hash_applied_mask_info_vec, search);
          if (minfo->mask_type_index == pae->mask_type_index)
            break;
        }
       
      vec_validate ((new_hash_applied_mask_info_vec), search);
      minfo = vec_elt_at_index ((new_hash_applied_mask_info_vec), search);
      if (search == new_pointer)
        {
          minfo->mask_type_index = pae->mask_type_index;
          minfo->num_entries = 0;
          minfo->max_collisions = 0;
          minfo->first_rule_index = ~0;
        }

      minfo->num_entries = minfo->num_entries + 1;

      if (vec_len (pae->colliding_rules) > minfo->max_collisions)
        minfo->max_collisions = vec_len (pae->colliding_rules);

      if (minfo->first_rule_index > i)
        minfo->first_rule_index = i;
    }

  hash_applied_mask_info_t **hash_applied_mask_info_vec =
    vec_elt_at_index (am->hash_applied_mask_info_vec_by_lc_index, lc_index);

  vec_free ((*hash_applied_mask_info_vec));
  (*hash_applied_mask_info_vec) = new_hash_applied_mask_info_vec;
}

static void
vec_del_collision_rule (collision_match_rule_t ** pvec,
                        u32 applied_entry_index)
{
  u32 i = 0;
  u32 deleted = 0;
  while (i < _vec_len ((*pvec)))
    {
      collision_match_rule_t *cr = vec_elt_at_index ((*pvec), i);
      if (cr->applied_entry_index == applied_entry_index)
        {
          /* vec_del1 ((*pvec), i) would be more efficient but would reorder the elements. */
          vec_delete((*pvec), 1, i);
          deleted++;
          DBG0("vec_del_collision_rule deleting one at index %d", i);
        }
      else
        {
          i++;
        }
    }
  ASSERT(deleted > 0);
}

static void
acl_plugin_print_pae (vlib_main_t * vm, int j, applied_hash_ace_entry_t * pae);

static void
del_colliding_rule (applied_hash_ace_entry_t ** applied_hash_aces,
                    u32 head_index, u32 applied_entry_index)
{
  DBG0("DEL COLLIDING RULE: head_index %d applied index %d", head_index, applied_entry_index);


  applied_hash_ace_entry_t *head_pae =
    vec_elt_at_index ((*applied_hash_aces), head_index);
  if (ACL_HASH_LOOKUP_DEBUG > 0)
    acl_plugin_print_pae(acl_main.vlib_main, head_index, head_pae);
  vec_del_collision_rule (&head_pae->colliding_rules, applied_entry_index);
  if (vec_len(head_pae->colliding_rules) == 0) {
    vec_free(head_pae->colliding_rules);
  }
  if (ACL_HASH_LOOKUP_DEBUG > 0)
    acl_plugin_print_pae(acl_main.vlib_main, head_index, head_pae);
}

static void
add_colliding_rule (acl_main_t * am,
                    applied_hash_ace_entry_t ** applied_hash_aces,
                    u32 head_index, u32 applied_entry_index)
{
  applied_hash_ace_entry_t *head_pae =
    vec_elt_at_index ((*applied_hash_aces), head_index);
  applied_hash_ace_entry_t *pae =
    vec_elt_at_index ((*applied_hash_aces), applied_entry_index);
  DBG0("ADD COLLIDING RULE: head_index %d applied index %d", head_index, applied_entry_index);
  if (ACL_HASH_LOOKUP_DEBUG > 0)
    acl_plugin_print_pae(acl_main.vlib_main, head_index, head_pae);

  collision_match_rule_t cr;

  cr.acl_index = pae->acl_index;
  cr.ace_index = pae->ace_index;
  cr.acl_position = pae->acl_position;
  cr.applied_entry_index = applied_entry_index;
  cr.rule = am->acls[pae->acl_index].rules[pae->ace_index];
  vec_add1 (head_pae->colliding_rules, cr);
  if (ACL_HASH_LOOKUP_DEBUG > 0)
    acl_plugin_print_pae(acl_main.vlib_main, head_index, head_pae);
}

static u32
activate_applied_ace_hash_entry(acl_main_t *am,
                            u32 lc_index,
                            applied_hash_ace_entry_t **applied_hash_aces,
                            u32 new_index)
{
  clib_bihash_kv_48_8_t kv;
  ASSERT(new_index != ~0);
  applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), new_index);
  DBG("activate_applied_ace_hash_entry lc_index %d new_index %d", lc_index, new_index);

  fill_applied_hash_ace_kv(am, applied_hash_aces, lc_index, new_index, &kv);

  DBG("APPLY ADD KY: %016llx %016llx %016llx %016llx %016llx %016llx",
			kv.key[0], kv.key[1], kv.key[2],
			kv.key[3], kv.key[4], kv.key[5]);

  clib_bihash_kv_48_8_t result;
  hash_acl_lookup_value_t *result_val = (hash_acl_lookup_value_t *)&result.value;
  int res = BV (clib_bihash_search) (&am->acl_lookup_hash, &kv, &result);
  ASSERT(new_index != ~0);
  ASSERT(new_index < vec_len((*applied_hash_aces)));
  if (res == 0) {
    /* There already exists an entry or more. Append at the end. */
    u32 first_index = result_val->applied_entry_index;
    ASSERT(first_index != ~0);
    DBG("A key already exists, with applied entry index: %d", first_index);
    applied_hash_ace_entry_t *first_pae = vec_elt_at_index((*applied_hash_aces), first_index);
    u32 last_index = first_pae->tail_applied_entry_index;
    ASSERT(last_index != ~0);
    applied_hash_ace_entry_t *last_pae = vec_elt_at_index((*applied_hash_aces), last_index);
    DBG("...advance to chained entry index: %d", last_index);
    /* link ourseves in */
    last_pae->next_applied_entry_index = new_index;
    pae->prev_applied_entry_index = last_index;
    /* adjust the pointer to the new tail */
    first_pae->tail_applied_entry_index = new_index;
    add_colliding_rule(am, applied_hash_aces, first_index, new_index);
    return first_index;
  } else {
    /* It's the very first entry */
    hashtable_add_del(am, &kv, 1);
    ASSERT(new_index != ~0);
    pae->tail_applied_entry_index = new_index;
    add_colliding_rule(am, applied_hash_aces, new_index, new_index);
    return new_index;
  }
}


static void *
hash_acl_set_heap(acl_main_t *am)
{
  if (0 == am->hash_lookup_mheap) {
    am->hash_lookup_mheap = mheap_alloc_with_lock (0 /* use VM */ , 
                                                   am->hash_lookup_mheap_size,
                                                   1 /* locked */);
    if (0 == am->hash_lookup_mheap) {
        clib_error("ACL plugin failed to allocate lookup heap of %U bytes", 
                   format_memory_size, am->hash_lookup_mheap_size);
    }
  }
  void *oldheap = clib_mem_set_heap(am->hash_lookup_mheap);
  return oldheap;
}

void
acl_plugin_hash_acl_set_validate_heap(int on)
{
  acl_main_t *am = &acl_main;
  clib_mem_set_heap(hash_acl_set_heap(am));
#if USE_DLMALLOC == 0
  mheap_t *h = mheap_header (am->hash_lookup_mheap);
  if (on) {
    h->flags |= MHEAP_FLAG_VALIDATE;
    h->flags &= ~MHEAP_FLAG_SMALL_OBJECT_CACHE;
    mheap_validate(h);
  } else {
    h->flags &= ~MHEAP_FLAG_VALIDATE;
    h->flags |= MHEAP_FLAG_SMALL_OBJECT_CACHE;
  }
#endif
}

void
acl_plugin_hash_acl_set_trace_heap(int on)
{
  acl_main_t *am = &acl_main;
  clib_mem_set_heap(hash_acl_set_heap(am));
#if USE_DLMALLOC == 0
  mheap_t *h = mheap_header (am->hash_lookup_mheap);
  if (on) {
    h->flags |= MHEAP_FLAG_TRACE;
  } else {
    h->flags &= ~MHEAP_FLAG_TRACE;
  }
#endif
}

static void
assign_mask_type_index_to_pae(acl_main_t *am, u32 lc_index, int is_ip6, applied_hash_ace_entry_t *pae)
{
  hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, pae->acl_index);
  hash_ace_info_t *ace_info = vec_elt_at_index(ha->rules, pae->hash_ace_info_index);

  ace_mask_type_entry_t *mte;
  fa_5tuple_t mask;
  /*
   * Start taking base_mask associated to ace, and essentially copy it.
   * With TupleMerge we will assign a relaxed mask here.
   */
  mte = vec_elt_at_index(am->ace_mask_type_pool, ace_info->base_mask_type_index);
  mask = mte->mask;
  if (am->use_tuple_merge)
    pae->mask_type_index = tm_assign_mask_type_index(am, &mask, is_ip6, lc_index);
  else
    pae->mask_type_index = assign_mask_type_index(am, &mask);
}

static void
split_partition(acl_main_t *am, u32 first_index,
                            u32 lc_index, int is_ip6);


static void
check_collision_count_and_maybe_split(acl_main_t *am, u32 lc_index, int is_ip6, u32 first_index)
{
  applied_hash_ace_entry_t **applied_hash_aces = get_applied_hash_aces(am, lc_index);
  applied_hash_ace_entry_t *first_pae = vec_elt_at_index((*applied_hash_aces), first_index);
  if (vec_len(first_pae->colliding_rules) > am->tuple_merge_split_threshold) {
    split_partition(am, first_index, lc_index, is_ip6);
  }
}

void
hash_acl_apply(acl_main_t *am, u32 lc_index, int acl_index, u32 acl_position)
{
  int i;

  DBG0("HASH ACL apply: lc_index %d acl %d", lc_index, acl_index);
  if (!am->acl_lookup_hash_initialized) {
    BV (clib_bihash_init) (&am->acl_lookup_hash, "ACL plugin rule lookup bihash",
                           am->hash_lookup_hash_buckets, am->hash_lookup_hash_memory);
    am->acl_lookup_hash_initialized = 1;
  }

  void *oldheap = hash_acl_set_heap(am);
  vec_validate(am->hash_entry_vec_by_lc_index, lc_index);
  vec_validate(am->hash_acl_infos, acl_index);
  applied_hash_ace_entry_t **applied_hash_aces = get_applied_hash_aces(am, lc_index);

  hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, acl_index);
  u32 **hash_acl_applied_lc_index = &ha->lc_index_list;

  int base_offset = vec_len(*applied_hash_aces);

  /* Update the bitmap of the mask types with which the lookup
     needs to happen for the ACLs applied to this lc_index */
  applied_hash_acl_info_t **applied_hash_acls = &am->applied_hash_acl_info_by_lc_index;
  vec_validate((*applied_hash_acls), lc_index);
  applied_hash_acl_info_t *pal = vec_elt_at_index((*applied_hash_acls), lc_index);

  /* ensure the list of applied hash acls is initialized and add this acl# to it */
  u32 index = vec_search(pal->applied_acls, acl_index);
  if (index != ~0) {
    clib_warning("BUG: trying to apply twice acl_index %d on lc_index %d, according to lc",
                 acl_index, lc_index);
    goto done;
  }
  vec_add1(pal->applied_acls, acl_index);
  u32 index2 = vec_search((*hash_acl_applied_lc_index), lc_index);
  if (index2 != ~0) {
    clib_warning("BUG: trying to apply twice acl_index %d on lc_index %d, according to hash h-acl info",
                 acl_index, lc_index);
    goto done;
  }
  vec_add1((*hash_acl_applied_lc_index), lc_index);

  /*
   * if the applied ACL is empty, the current code will cause a
   * different behavior compared to current linear search: an empty ACL will
   * simply fallthrough to the next ACL, or the default deny in the end.
   *
   * This is not a problem, because after vpp-dev discussion,
   * the consensus was it should not be possible to apply the non-existent
   * ACL, so the change adding this code also takes care of that.
   */

  /* expand the applied aces vector by the necessary amount */
  vec_resize((*applied_hash_aces), vec_len(ha->rules));

  vec_validate(am->hash_applied_mask_info_vec_by_lc_index, lc_index);
  /* add the rules from the ACL to the hash table for lookup and append to the vector*/
  for(i=0; i < vec_len(ha->rules); i++) {
    int is_ip6 = ha->rules[i].match.pkt.is_ip6;
    u32 new_index = base_offset + i;
    applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), new_index);
    pae->acl_index = acl_index;
    pae->ace_index = ha->rules[i].ace_index;
    pae->acl_position = acl_position;
    pae->action = ha->rules[i].action;
    pae->hitcount = 0;
    pae->hash_ace_info_index = i;
    /* we might link it in later */
    pae->next_applied_entry_index = ~0;
    pae->prev_applied_entry_index = ~0;
    pae->tail_applied_entry_index = ~0;
    pae->colliding_rules = NULL;
    pae->mask_type_index = ~0;
    assign_mask_type_index_to_pae(am, lc_index, is_ip6, pae);
    u32 first_index = activate_applied_ace_hash_entry(am, lc_index, applied_hash_aces, new_index);
    if (am->use_tuple_merge)
      check_collision_count_and_maybe_split(am, lc_index, is_ip6, first_index);
  }
  remake_hash_applied_mask_info_vec(am, applied_hash_aces, lc_index);
done:
  clib_mem_set_heap (oldheap);
}

static u32
find_head_applied_ace_index(applied_hash_ace_entry_t **applied_hash_aces, u32 curr_index)
{
  /*
   * find back the first entry. Inefficient so might need to be a bit cleverer
   * if this proves to be a problem..
   */
  u32 an_index = curr_index;
  ASSERT(an_index != ~0);
  applied_hash_ace_entry_t *head_pae = vec_elt_at_index((*applied_hash_aces), an_index);
  while(head_pae->prev_applied_entry_index != ~0) {
    an_index = head_pae->prev_applied_entry_index;
    ASSERT(an_index != ~0);
    head_pae = vec_elt_at_index((*applied_hash_aces), an_index);
  }
  return an_index;
}

static void
move_applied_ace_hash_entry(acl_main_t *am,
                            u32 lc_index,
                            applied_hash_ace_entry_t **applied_hash_aces,
                            u32 old_index, u32 new_index)
{
  ASSERT(old_index != ~0);
  ASSERT(new_index != ~0);
  /* move the entry */
  *vec_elt_at_index((*applied_hash_aces), new_index) = *vec_elt_at_index((*applied_hash_aces), old_index);

  /* update the linkage and hash table if necessary */
  applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), old_index);
  applied_hash_ace_entry_t *new_pae = vec_elt_at_index((*applied_hash_aces), new_index);

  if (ACL_HASH_LOOKUP_DEBUG > 0) {
    clib_warning("Moving pae from %d to %d", old_index, new_index);
    acl_plugin_print_pae(am->vlib_main, old_index, pae);
  }

  if (new_pae->tail_applied_entry_index == old_index) {
    /* fix-up the tail index if we are the tail and the start */
    new_pae->tail_applied_entry_index = new_index;
  }

  if (pae->prev_applied_entry_index != ~0) {
    applied_hash_ace_entry_t *prev_pae = vec_elt_at_index((*applied_hash_aces), pae->prev_applied_entry_index);
    ASSERT(prev_pae->next_applied_entry_index == old_index);
    prev_pae->next_applied_entry_index = new_index;
  } else {
    /* first entry - so the hash points to it, update */
    add_del_hashtable_entry(am, lc_index,
                            applied_hash_aces, new_index, 1);
    ASSERT(pae->tail_applied_entry_index != ~0);
  }
  if (pae->next_applied_entry_index != ~0) {
    applied_hash_ace_entry_t *next_pae = vec_elt_at_index((*applied_hash_aces), pae->next_applied_entry_index);
    ASSERT(next_pae->prev_applied_entry_index == old_index);
    next_pae->prev_applied_entry_index = new_index;
  } else {
    /*
     * Moving the very last entry, so we need to update the tail pointer in the first one.
     */
    u32 head_index = find_head_applied_ace_index(applied_hash_aces, old_index);
    ASSERT(head_index != ~0);
    applied_hash_ace_entry_t *head_pae = vec_elt_at_index((*applied_hash_aces), head_index);

    ASSERT(head_pae->tail_applied_entry_index == old_index);
    head_pae->tail_applied_entry_index = new_index;
  }
  if (new_pae->colliding_rules) {
    /* update the information within the collision rule entry */
    ASSERT(vec_len(new_pae->colliding_rules) > 0);
    collision_match_rule_t *cr = vec_elt_at_index (new_pae->colliding_rules, 0);
    ASSERT(cr->applied_entry_index == old_index);
    cr->applied_entry_index = new_index;
  } else {
    /* find the index in the collision rule entry on the head element */
    u32 head_index = find_head_applied_ace_index(applied_hash_aces, new_index);
    ASSERT(head_index != ~0);
    applied_hash_ace_entry_t *head_pae = vec_elt_at_index((*applied_hash_aces), head_index);
    ASSERT(vec_len(head_pae->colliding_rules) > 0);
    u32 i;
    for (i=0; i<vec_len(head_pae->colliding_rules); i++) {
      collision_match_rule_t *cr = vec_elt_at_index (head_pae->colliding_rules, i);
      if (cr->applied_entry_index == old_index) {
        cr->applied_entry_index = new_index;
      }
    }
    if (ACL_HASH_LOOKUP_DEBUG > 0) {
      clib_warning("Head pae at index %d after adjustment", head_index);
      acl_plugin_print_pae(am->vlib_main, head_index, head_pae);
    }
  }
  /* invalidate the old entry */
  pae->prev_applied_entry_index = ~0;
  pae->next_applied_entry_index = ~0;
  pae->tail_applied_entry_index = ~0;
  pae->colliding_rules = NULL;
}

static void
deactivate_applied_ace_hash_entry(acl_main_t *am,
                            u32 lc_index,
                            applied_hash_ace_entry_t **applied_hash_aces,
                            u32 old_index)
{
  applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), old_index);
  DBG("UNAPPLY DEACTIVATE: lc_index %d applied index %d", lc_index, old_index);

  if (pae->prev_applied_entry_index != ~0) {
    DBG("UNAPPLY = index %d has prev_applied_entry_index %d", old_index, pae->prev_applied_entry_index);
    applied_hash_ace_entry_t *prev_pae = vec_elt_at_index((*applied_hash_aces), pae->prev_applied_entry_index);
    ASSERT(prev_pae->next_applied_entry_index == old_index);
    prev_pae->next_applied_entry_index = pae->next_applied_entry_index;

    u32 head_index = find_head_applied_ace_index(applied_hash_aces, old_index);
    ASSERT(head_index != ~0);
    applied_hash_ace_entry_t *head_pae = vec_elt_at_index((*applied_hash_aces), head_index);
    del_colliding_rule(applied_hash_aces, head_index, old_index);

    if (pae->next_applied_entry_index == ~0) {
      /* it was a last entry we removed, update the pointer on the first one */
      ASSERT(head_pae->tail_applied_entry_index == old_index);
      head_pae->tail_applied_entry_index = pae->prev_applied_entry_index;
    } else {
      applied_hash_ace_entry_t *next_pae = vec_elt_at_index((*applied_hash_aces), pae->next_applied_entry_index);
      next_pae->prev_applied_entry_index = pae->prev_applied_entry_index;
    }
  } else {
    /* It was the first entry. We need either to reset the hash entry or delete it */
    /* delete our entry from the collision vector first */
    del_colliding_rule(applied_hash_aces, old_index, old_index);
    if (pae->next_applied_entry_index != ~0) {
      /* the next element becomes the new first one, so needs the tail pointer to be set */
      applied_hash_ace_entry_t *next_pae = vec_elt_at_index((*applied_hash_aces), pae->next_applied_entry_index);
      ASSERT(pae->tail_applied_entry_index != ~0);
      next_pae->tail_applied_entry_index = pae->tail_applied_entry_index;
      /* Remove ourselves and transfer the ownership of the colliding rules vector */
      next_pae->colliding_rules = pae->colliding_rules;
      /* unlink from the next element */
      next_pae->prev_applied_entry_index = ~0;
      add_del_hashtable_entry(am, lc_index,
                              applied_hash_aces, pae->next_applied_entry_index, 1);
    } else {
      /* no next entry, so just delete the entry in the hash table */
      add_del_hashtable_entry(am, lc_index,
                              applied_hash_aces, old_index, 0);
    }
  }

  release_mask_type_index(am, pae->mask_type_index);
  /* invalidate the old entry */
  pae->mask_type_index = ~0;
  pae->prev_applied_entry_index = ~0;
  pae->next_applied_entry_index = ~0;
  pae->tail_applied_entry_index = ~0;
  /* always has to be 0 */
  pae->colliding_rules = NULL;
}


void
hash_acl_unapply(acl_main_t *am, u32 lc_index, int acl_index)
{
  int i;

  DBG0("HASH ACL unapply: lc_index %d acl %d", lc_index, acl_index);
  applied_hash_acl_info_t **applied_hash_acls = &am->applied_hash_acl_info_by_lc_index;
  applied_hash_acl_info_t *pal = vec_elt_at_index((*applied_hash_acls), lc_index);

  hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, acl_index);
  u32 **hash_acl_applied_lc_index = &ha->lc_index_list;

  /* remove this acl# from the list of applied hash acls */
  u32 index = vec_search(pal->applied_acls, acl_index);
  if (index == ~0) {
    clib_warning("BUG: trying to unapply unapplied acl_index %d on lc_index %d, according to lc",
                 acl_index, lc_index);
    return;
  }
  vec_del1(pal->applied_acls, index);

  u32 index2 = vec_search((*hash_acl_applied_lc_index), lc_index);
  if (index2 == ~0) {
    clib_warning("BUG: trying to unapply twice acl_index %d on lc_index %d, according to h-acl info",
                 acl_index, lc_index);
    return;
  }
  vec_del1((*hash_acl_applied_lc_index), index2);

  applied_hash_ace_entry_t **applied_hash_aces = get_applied_hash_aces(am, lc_index);

  for(i=0; i < vec_len((*applied_hash_aces)); i++) {
    if (vec_elt_at_index(*applied_hash_aces,i)->acl_index == acl_index) {
      DBG("Found applied ACL#%d at applied index %d", acl_index, i);
      break;
    }
  }
  if (vec_len((*applied_hash_aces)) <= i) {
    DBG("Did not find applied ACL#%d at lc_index %d", acl_index, lc_index);
    /* we went all the way without finding any entries. Probably a list was empty. */
    return;
  }

  void *oldheap = hash_acl_set_heap(am);
  int base_offset = i;
  int tail_offset = base_offset + vec_len(ha->rules);
  int tail_len = vec_len((*applied_hash_aces)) - tail_offset;
  DBG("base_offset: %d, tail_offset: %d, tail_len: %d", base_offset, tail_offset, tail_len);

  for(i=0; i < vec_len(ha->rules); i ++) {
    deactivate_applied_ace_hash_entry(am, lc_index,
                                      applied_hash_aces, base_offset + i);
  }
  for(i=0; i < tail_len; i ++) {
    /* move the entry at tail offset to base offset */
    /* that is, from (tail_offset+i) -> (base_offset+i) */
    DBG("UNAPPLY MOVE: lc_index %d, applied index %d -> %d", lc_index, tail_offset+i, base_offset + i);
    move_applied_ace_hash_entry(am, lc_index, applied_hash_aces, tail_offset + i, base_offset + i);
  }
  /* trim the end of the vector */
  _vec_len((*applied_hash_aces)) -= vec_len(ha->rules);

  remake_hash_applied_mask_info_vec(am, applied_hash_aces, lc_index);

  if (vec_len((*applied_hash_aces)) == 0) {
    vec_free((*applied_hash_aces));
  }

  clib_mem_set_heap (oldheap);
}

/*
 * Create the applied ACEs and update the hash table,
 * taking into account that the ACL may not be the last
 * in the vector of applied ACLs.
 *
 * For now, walk from the end of the vector and unapply the ACLs,
 * then apply the one in question and reapply the rest.
 */

void
hash_acl_reapply(acl_main_t *am, u32 lc_index, int acl_index)
{
  acl_lookup_context_t *acontext = pool_elt_at_index(am->acl_lookup_contexts, lc_index);
  u32 **applied_acls = &acontext->acl_indices;
  int i;
  int start_index = vec_search((*applied_acls), acl_index);

  DBG0("Start index for acl %d in lc_index %d is %d", acl_index, lc_index, start_index);
  /*
   * This function is called after we find out the lc_index where ACL is applied.
   * If the by-lc_index vector does not have the ACL#, then it's a bug.
   */
  ASSERT(start_index < vec_len(*applied_acls));

  /* unapply all the ACLs at the tail side, up to the current one */
  for(i = vec_len(*applied_acls) - 1; i > start_index; i--) {
    hash_acl_unapply(am, lc_index, *vec_elt_at_index(*applied_acls, i));
  }
  for(i = start_index; i < vec_len(*applied_acls); i++) {
    hash_acl_apply(am, lc_index, *vec_elt_at_index(*applied_acls, i), i);
  }
}

static void
make_ip6_address_mask(ip6_address_t *addr, u8 prefix_len)
{
  ip6_address_mask_from_width(addr, prefix_len);
}


/* Maybe should be moved into the core somewhere */
always_inline void
ip4_address_mask_from_width (ip4_address_t * a, u32 width)
{
  int i, byte, bit, bitnum;
  ASSERT (width <= 32);
  memset (a, 0, sizeof (a[0]));
  for (i = 0; i < width; i++)
    {
      bitnum = (7 - (i & 7));
      byte = i / 8;
      bit = 1 << bitnum;
      a->as_u8[byte] |= bit;
    }
}


static void
make_ip4_address_mask(ip4_address_t *addr, u8 prefix_len)
{
  ip4_address_mask_from_width(addr, prefix_len);
}

static void
make_port_mask(u16 *portmask, u16 port_first, u16 port_last)
{
  if (port_first == port_last) {
    *portmask = 0xffff;
    /* single port is representable by masked value */
    return;
  }

  *portmask = 0;
  return;
}

static void
make_mask_and_match_from_rule(fa_5tuple_t *mask, acl_rule_t *r, hash_ace_info_t *hi)
{
  memset(mask, 0, sizeof(*mask));
  memset(&hi->match, 0, sizeof(hi->match));
  hi->action = r->is_permit;

  /* we will need to be matching based on lc_index and mask_type_index when applied */
  mask->pkt.lc_index = ~0;
  /* we will assign the match of mask_type_index later when we find it*/
  mask->pkt.mask_type_index_lsb = ~0;

  mask->pkt.is_ip6 = 1;
  hi->match.pkt.is_ip6 = r->is_ipv6;
  if (r->is_ipv6) {
    make_ip6_address_mask(&mask->ip6_addr[0], r->src_prefixlen);
    hi->match.ip6_addr[0] = r->src.ip6;
    make_ip6_address_mask(&mask->ip6_addr[1], r->dst_prefixlen);
    hi->match.ip6_addr[1] = r->dst.ip6;
  } else {
    memset(hi->match.l3_zero_pad, 0, sizeof(hi->match.l3_zero_pad));
    make_ip4_address_mask(&mask->ip4_addr[0], r->src_prefixlen);
    hi->match.ip4_addr[0] = r->src.ip4;
    make_ip4_address_mask(&mask->ip4_addr[1], r->dst_prefixlen);
    hi->match.ip4_addr[1] = r->dst.ip4;
  }

  if (r->proto != 0) {
    mask->l4.proto = ~0; /* L4 proto needs to be matched */
    hi->match.l4.proto = r->proto;

    /* Calculate the src/dst port masks and make the src/dst port matches accordingly */
    make_port_mask(&mask->l4.port[0], r->src_port_or_type_first, r->src_port_or_type_last);
    hi->match.l4.port[0] = r->src_port_or_type_first & mask->l4.port[0];

    make_port_mask(&mask->l4.port[1], r->dst_port_or_code_first, r->dst_port_or_code_last);
    hi->match.l4.port[1] = r->dst_port_or_code_first & mask->l4.port[1];
    /* L4 info must be valid in order to match */
    mask->pkt.l4_valid = 1;
    hi->match.pkt.l4_valid = 1;
    /* And we must set the mask to check that it is an initial fragment */
    mask->pkt.is_nonfirst_fragment = 1;
    hi->match.pkt.is_nonfirst_fragment = 0;
    if ((r->proto == IPPROTO_TCP) && (r->tcp_flags_mask != 0)) {
      /* if we want to match on TCP flags, they must be masked off as well */
      mask->pkt.tcp_flags = r->tcp_flags_mask;
      hi->match.pkt.tcp_flags = r->tcp_flags_value;
      /* and the flags need to be present within the packet being matched */
      mask->pkt.tcp_flags_valid = 1;
      hi->match.pkt.tcp_flags_valid = 1;
    }
  }
  /* Sanitize the mask and the match */
  u64 *pmask = (u64 *)mask;
  u64 *pmatch = (u64 *)&hi->match;
  int j;
  for(j=0; j<6; j++) {
    pmatch[j] = pmatch[j] & pmask[j];
  }
}


int hash_acl_exists(acl_main_t *am, int acl_index)
{
  if (acl_index >= vec_len(am->hash_acl_infos))
    return 0;

  hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, acl_index);
  return ha->hash_acl_exists;
}

void hash_acl_add(acl_main_t *am, int acl_index)
{
  void *oldheap = hash_acl_set_heap(am);
  DBG("HASH ACL add : %d", acl_index);
  int i;
  acl_list_t *a = &am->acls[acl_index];
  vec_validate(am->hash_acl_infos, acl_index);
  hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, acl_index);
  memset(ha, 0, sizeof(*ha));
  ha->hash_acl_exists = 1;

  /* walk the newly added ACL entries and ensure that for each of them there
     is a mask type, increment a reference count for that mask type */
  for(i=0; i < a->count; i++) {
    hash_ace_info_t ace_info;
    fa_5tuple_t mask;
    memset(&ace_info, 0, sizeof(ace_info));
    ace_info.acl_index = acl_index;
    ace_info.ace_index = i;

    make_mask_and_match_from_rule(&mask, &a->rules[i], &ace_info);
    mask.pkt.flags_reserved = 0b000;
    ace_info.base_mask_type_index = assign_mask_type_index(am, &mask);
    /* assign the mask type index for matching itself */
    ace_info.match.pkt.mask_type_index_lsb = ace_info.base_mask_type_index;
    DBG("ACE: %d mask_type_index: %d", i, ace_info.base_mask_type_index);
    vec_add1(ha->rules, ace_info);
  }
  /*
   * if an ACL is applied somewhere, fill the corresponding lookup data structures.
   * We need to take care if the ACL is not the last one in the vector of ACLs applied to the interface.
   */
  if (acl_index < vec_len(am->lc_index_vec_by_acl)) {
    u32 *lc_index;
    vec_foreach(lc_index, am->lc_index_vec_by_acl[acl_index]) {
      hash_acl_reapply(am, *lc_index, acl_index);
    }
  }
  clib_mem_set_heap (oldheap);
}

void hash_acl_delete(acl_main_t *am, int acl_index)
{
  void *oldheap = hash_acl_set_heap(am);
  DBG0("HASH ACL delete : %d", acl_index);
  /*
   * If the ACL is applied somewhere, remove the references of it (call hash_acl_unapply)
   * this is a different behavior from the linear lookup where an empty ACL is "deny all",
   *
   * However, following vpp-dev discussion the ACL that is referenced elsewhere
   * should not be possible to delete, and the change adding this also adds
   * the safeguards to that respect, so this is not a problem.
   *
   * The part to rememeber is that this routine is called in process of reapplication
   * during the acl_add_replace() API call - the old acl ruleset is deleted, then
   * the new one is added, without the change in the applied ACLs - so this case
   * has to be handled.
   */
  hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, acl_index);
  u32 *lc_list_copy = 0;
  {
    u32 *lc_index;
    lc_list_copy = vec_dup(ha->lc_index_list);
    vec_foreach(lc_index, lc_list_copy) {
      hash_acl_unapply(am, *lc_index, acl_index);
    }
    vec_free(lc_list_copy);
  }
  vec_free(ha->lc_index_list);

  /* walk the mask types for the ACL about-to-be-deleted, and decrease
   * the reference count, possibly freeing up some of them */
  int i;
  for(i=0; i < vec_len(ha->rules); i++) {
    release_mask_type_index(am, ha->rules[i].base_mask_type_index);
  }
  ha->hash_acl_exists = 0;
  vec_free(ha->rules);
  clib_mem_set_heap (oldheap);
}


void
show_hash_acl_hash (vlib_main_t * vm, acl_main_t *am, u32 verbose)
{
  vlib_cli_output(vm, "\nACL lookup hash table:\n%U\n",
                  BV (format_bihash), &am->acl_lookup_hash, verbose);
}

void
acl_plugin_show_tables_mask_type (void)
{
  acl_main_t *am = &acl_main;
  vlib_main_t *vm = am->vlib_main;
  ace_mask_type_entry_t *mte;

  vlib_cli_output (vm, "Mask-type entries:");
    /* *INDENT-OFF* */
    pool_foreach(mte, am->ace_mask_type_pool,
    ({
      vlib_cli_output(vm, "     %3d: %016llx %016llx %016llx %016llx %016llx %016llx  refcount %d",
		    mte - am->ace_mask_type_pool,
		    mte->mask.kv_40_8.key[0], mte->mask.kv_40_8.key[1], mte->mask.kv_40_8.key[2],
		    mte->mask.kv_40_8.key[3], mte->mask.kv_40_8.key[4], mte->mask.kv_40_8.value, mte->refcount);
    }));
    /* *INDENT-ON* */
}

void
acl_plugin_show_tables_acl_hash_info (u32 acl_index)
{
  acl_main_t *am = &acl_main;
  vlib_main_t *vm = am->vlib_main;
  u32 i, j;
  u64 *m;
  vlib_cli_output (vm, "Mask-ready ACL representations\n");
  for (i = 0; i < vec_len (am->hash_acl_infos); i++)
    {
      if ((acl_index != ~0) && (acl_index != i))
	{
	  continue;
	}
      hash_acl_info_t *ha = &am->hash_acl_infos[i];
      vlib_cli_output (vm, "acl-index %u bitmask-ready layout\n", i);
      vlib_cli_output (vm, "  applied lc_index list: %U\n",
		       format_vec32, ha->lc_index_list, "%d");
      for (j = 0; j < vec_len (ha->rules); j++)
	{
	  hash_ace_info_t *pa = &ha->rules[j];
	  m = (u64 *) & pa->match;
	  vlib_cli_output (vm,
			   "    %4d: %016llx %016llx %016llx %016llx %016llx %016llx base mask index %d acl %d rule %d action %d\n",
			   j, m[0], m[1], m[2], m[3], m[4], m[5],
			   pa->base_mask_type_index, pa->acl_index, pa->ace_index,
			   pa->action);
	}
    }
}

static void
acl_plugin_print_colliding_rule (vlib_main_t * vm, int j, collision_match_rule_t *cr) {
  vlib_cli_output(vm,
                  "        %4d: acl %d ace %d acl pos %d pae index: %d",
                  j, cr->acl_index, cr->ace_index, cr->acl_position, cr->applied_entry_index);
}

static void
acl_plugin_print_pae (vlib_main_t * vm, int j, applied_hash_ace_entry_t * pae)
{
  vlib_cli_output (vm,
		   "    %4d: acl %d rule %d action %d bitmask-ready rule %d colliding_rules: %d next %d prev %d tail %d hitcount %lld acl_pos: %d",
		   j, pae->acl_index, pae->ace_index, pae->action,
		   pae->hash_ace_info_index, vec_len(pae->colliding_rules), pae->next_applied_entry_index,
		   pae->prev_applied_entry_index,
		   pae->tail_applied_entry_index, pae->hitcount, pae->acl_position);
  int jj;
  for(jj=0; jj<vec_len(pae->colliding_rules); jj++)
    acl_plugin_print_colliding_rule(vm, jj, vec_elt_at_index(pae->colliding_rules, jj));
}

static void
acl_plugin_print_applied_mask_info (vlib_main_t * vm, int j, hash_applied_mask_info_t *mi)
{
  vlib_cli_output (vm,
		   "    %4d: mask type index %d first rule index %d num_entries %d max_collisions %d",
		   j, mi->mask_type_index, mi->first_rule_index, mi->num_entries, mi->max_collisions);
}

void
acl_plugin_show_tables_applied_info (u32 lc_index)
{
  acl_main_t *am = &acl_main;
  vlib_main_t *vm = am->vlib_main;
  u32 lci, j;
  vlib_cli_output (vm, "Applied lookup entries for lookup contexts");

  for (lci = 0;
       (lci < vec_len(am->applied_hash_acl_info_by_lc_index)); lci++)
    {
      if ((lc_index != ~0) && (lc_index != lci))
	{
	  continue;
	}
      vlib_cli_output (vm, "lc_index %d:", lci);
      if (lci < vec_len (am->applied_hash_acl_info_by_lc_index))
	{
	  applied_hash_acl_info_t *pal =
	    &am->applied_hash_acl_info_by_lc_index[lci];
	  vlib_cli_output (vm, "  applied acls: %U", format_vec32,
			   pal->applied_acls, "%d");
	}
      if (lci < vec_len (am->hash_applied_mask_info_vec_by_lc_index))
	{
	  vlib_cli_output (vm, "  applied mask info entries:");
	  for (j = 0;
	       j < vec_len (am->hash_applied_mask_info_vec_by_lc_index[lci]);
	       j++)
	    {
	      acl_plugin_print_applied_mask_info (vm, j,
				    &am->hash_applied_mask_info_vec_by_lc_index
				    [lci][j]);
	    }
	}
      if (lci < vec_len (am->hash_entry_vec_by_lc_index))
	{
	  vlib_cli_output (vm, "  lookup applied entries:");
	  for (j = 0;
	       j < vec_len (am->hash_entry_vec_by_lc_index[lci]);
	       j++)
	    {
	      acl_plugin_print_pae (vm, j,
				    &am->hash_entry_vec_by_lc_index
				    [lci][j]);
	    }
	}
    }
}

void
acl_plugin_show_tables_bihash (u32 show_bihash_verbose)
{
  acl_main_t *am = &acl_main;
  vlib_main_t *vm = am->vlib_main;
  show_hash_acl_hash (vm, am, show_bihash_verbose);
}

/*
 * Split of the partition needs to happen when the collision count
 * goes over a specified threshold.
 *
 * This is a signal that we ignored too many bits in
 * mT and we need to split the table into two tables. We select
 * all of the colliding rules L and find their maximum common
 * tuple mL. Normally mL is specific enough to hash L with few
 * or no collisions. We then create a new table T2 with tuple mL
 * and transfer all compatible rules from T to T2. If mL is not
 * specific enough, we find the field with the biggest difference
 * between the minimum and maximum tuple lengths for all of
 * the rules in L and set that field to be the average of those two
 * values. We then transfer all compatible rules as before. This
 * guarantees that some rules from L will move and that T2 will
 * have a smaller number of collisions than T did.
 */


static void
ensure_ip6_min_addr (ip6_address_t * min_addr, ip6_address_t * mask_addr)
{
  int update =
    (clib_net_to_host_u64 (mask_addr->as_u64[0]) <
     clib_net_to_host_u64 (min_addr->as_u64[0]))
    ||
    ((clib_net_to_host_u64 (mask_addr->as_u64[0]) ==
      clib_net_to_host_u64 (min_addr->as_u64[0]))
     && (clib_net_to_host_u64 (mask_addr->as_u64[1]) <
	 clib_net_to_host_u64 (min_addr->as_u64[1])));
  if (update)
    {
      min_addr->as_u64[0] = mask_addr->as_u64[0];
      min_addr->as_u64[1] = mask_addr->as_u64[1];
    }
}

static void
ensure_ip6_max_addr (ip6_address_t * max_addr, ip6_address_t * mask_addr)
{
  int update =
    (clib_net_to_host_u64 (mask_addr->as_u64[0]) >
     clib_net_to_host_u64 (max_addr->as_u64[0]))
    ||
    ((clib_net_to_host_u64 (mask_addr->as_u64[0]) ==
      clib_net_to_host_u64 (max_addr->as_u64[0]))
     && (clib_net_to_host_u64 (mask_addr->as_u64[1]) >
	 clib_net_to_host_u64 (max_addr->as_u64[1])));
  if (update)
    {
      max_addr->as_u64[0] = mask_addr->as_u64[0];
      max_addr->as_u64[1] = mask_addr->as_u64[1];
    }
}

static void
ensure_ip4_min_addr (ip4_address_t * min_addr, ip4_address_t * mask_addr)
{
  int update =
    (clib_net_to_host_u32 (mask_addr->as_u32) <
     clib_net_to_host_u32 (min_addr->as_u32));
  if (update)
    min_addr->as_u32 = mask_addr->as_u32;
}

static void
ensure_ip4_max_addr (ip4_address_t * max_addr, ip4_address_t * mask_addr)
{
  int update =
    (clib_net_to_host_u32 (mask_addr->as_u32) >
     clib_net_to_host_u32 (max_addr->as_u32));
  if (update)
    max_addr->as_u32 = mask_addr->as_u32;
}

enum {
  DIM_SRC_ADDR = 0,
  DIM_DST_ADDR,
  DIM_SRC_PORT,
  DIM_DST_PORT,
  DIM_PROTO,
};



static void
split_partition(acl_main_t *am, u32 first_index,
                            u32 lc_index, int is_ip6){
	DBG( "TM-split_partition - first_entry:%d", first_index);
        applied_hash_ace_entry_t **applied_hash_aces = get_applied_hash_aces(am, lc_index);
	ace_mask_type_entry_t *mte;
	fa_5tuple_t the_min_tuple, *min_tuple = &the_min_tuple;
        fa_5tuple_t the_max_tuple, *max_tuple = &the_max_tuple;
	applied_hash_ace_entry_t *pae = vec_elt_at_index((*applied_hash_aces), first_index);
	hash_acl_info_t *ha = vec_elt_at_index(am->hash_acl_infos, pae->acl_index);
	hash_ace_info_t *ace_info;
	u32 coll_mask_type_index = pae->mask_type_index;
        memset(&the_min_tuple, 0, sizeof(the_min_tuple));
        memset(&the_max_tuple, 0, sizeof(the_max_tuple));

	int i=0;
	u64 collisions = vec_len(pae->colliding_rules);
//	while(pae->next_applied_entry_index == ~0){
	for(i=0; i<collisions; i++){

		DBG( "TM-collision: base_ace:%d (ace_mask:%d, first_collision_mask:%d)",
				pae->ace_index, pae->mask_type_index, coll_mask_type_index);

		ace_info = vec_elt_at_index(ha->rules, pae->hash_ace_info_index);
		mte = vec_elt_at_index(am->ace_mask_type_pool, ace_info->base_mask_type_index);
		fa_5tuple_t *mask = &mte->mask;

		if(pae->mask_type_index != coll_mask_type_index) continue;
		/* Computing min_mask and max_mask for colliding rules */
		if(i==0){
			clib_memcpy(min_tuple, mask, sizeof(fa_5tuple_t));
			clib_memcpy(max_tuple, mask, sizeof(fa_5tuple_t));
		}else{
			int j;
			for(j=0; j<2; j++){
                                if (is_ip6)
                                  ensure_ip6_min_addr(&min_tuple->ip6_addr[j], &mask->ip6_addr[j]);
                                else
                                  ensure_ip4_min_addr(&min_tuple->ip4_addr[j], &mask->ip4_addr[j]);

				if ((mask->l4.port[j] < min_tuple->l4.port[j]))
					min_tuple->l4.port[j] = mask->l4.port[j];
			}

			if ((mask->l4.proto < min_tuple->l4.proto))
				min_tuple->l4.proto = mask->l4.proto;

			if(mask->pkt.as_u64 < min_tuple->pkt.as_u64)
				min_tuple->pkt.as_u64 = mask->pkt.as_u64;


			for(j=0; j<2; j++){
                                if (is_ip6)
                                  ensure_ip6_max_addr(&max_tuple->ip6_addr[j], &mask->ip6_addr[j]);
                                else
                                  ensure_ip4_max_addr(&max_tuple->ip4_addr[j], &mask->ip4_addr[j]);

				if ((mask->l4.port[j] > max_tuple->l4.port[j]))
					max_tuple->l4.port[j] = mask->l4.port[j];
			}

			if ((mask->l4.proto < max_tuple->l4.proto))
				max_tuple->l4.proto = mask->l4.proto;

			if(mask->pkt.as_u64 > max_tuple->pkt.as_u64)
				max_tuple->pkt.as_u64 = mask->pkt.as_u64;
		}

		pae = vec_elt_at_index((*applied_hash_aces), pae->next_applied_entry_index);
	}

	/* Computing field with max difference between (min/max)_mask */
	int best_dim=-1, best_delta=0, delta=0;

	/* SRC_addr dimension */
        if (is_ip6) {
	  int i;
	  for(i=0; i<2; i++){
		delta += count_bits(max_tuple->ip6_addr[0].as_u64[i]) - count_bits(min_tuple->ip6_addr[0].as_u64[i]);
	  }
        } else {
		delta += count_bits(max_tuple->ip4_addr[0].as_u32) - count_bits(min_tuple->ip4_addr[0].as_u32);
        }
	if(delta > best_delta){
		best_delta = delta;
		best_dim = DIM_SRC_ADDR;
	}

	/* DST_addr dimension */
	delta = 0;
        if (is_ip6) {
	  int i;
	  for(i=0; i<2; i++){
		delta += count_bits(max_tuple->ip6_addr[1].as_u64[i]) - count_bits(min_tuple->ip6_addr[1].as_u64[i]);
	  }
        } else {
		delta += count_bits(max_tuple->ip4_addr[1].as_u32) - count_bits(min_tuple->ip4_addr[1].as_u32);
        }
	if(delta > best_delta){
		best_delta = delta;
		best_dim = DIM_DST_ADDR;
	}

	/* SRC_port dimension */
	delta = count_bits(max_tuple->l4.port[0]) - count_bits(min_tuple->l4.port[0]);
	if(delta > best_delta){
		best_delta = delta;
		best_dim = DIM_SRC_PORT;
	}

	/* DST_port dimension */
	delta = count_bits(max_tuple->l4.port[1]) - count_bits(min_tuple->l4.port[1]);
	if(delta > best_delta){
		best_delta = delta;
		best_dim = DIM_DST_PORT;
	}

	/* Proto dimension */
	delta = count_bits(max_tuple->l4.proto) - count_bits(min_tuple->l4.proto);
	if(delta > best_delta){
		best_delta = delta;
		best_dim = DIM_PROTO;
	}

	int shifting = 0; //, ipv4_block = 0;
	switch(best_dim){
		case DIM_SRC_ADDR:
			shifting = (best_delta)/2; // FIXME IPV4-only
			// ipv4_block = count_bits(max_tuple->ip4_addr[0].as_u32);
			min_tuple->ip4_addr[0].as_u32 =
					clib_host_to_net_u32((clib_net_to_host_u32(max_tuple->ip4_addr[0].as_u32) << (shifting))&0xFFFFFFFF);

			break;
		case DIM_DST_ADDR:
			shifting = (best_delta)/2;
/*
			ipv4_block = count_bits(max_tuple->addr[1].as_u64[1]);
			if(ipv4_block > shifting)
				min_tuple->addr[1].as_u64[1] =
					clib_host_to_net_u64((clib_net_to_host_u64(max_tuple->addr[1].as_u64[1]) << (shifting))&0xFFFFFFFF);
			else{
				shifting = shifting - ipv4_block;
				min_tuple->addr[1].as_u64[1] = 0;
				min_tuple->addr[1].as_u64[0] =
					clib_host_to_net_u64((clib_net_to_host_u64(max_tuple->addr[1].as_u64[0]) << (shifting))&0xFFFFFFFF);
			}
*/
			min_tuple->ip4_addr[1].as_u32 =
					clib_host_to_net_u32((clib_net_to_host_u32(max_tuple->ip4_addr[1].as_u32) << (shifting))&0xFFFFFFFF);

			break;
		case DIM_SRC_PORT: min_tuple->l4.port[0] = max_tuple->l4.port[0]  << (best_delta)/2;
			break;
		case DIM_DST_PORT: min_tuple->l4.port[1] = max_tuple->l4.port[1] << (best_delta)/2;
			break;
		case DIM_PROTO: min_tuple->l4.proto = max_tuple->l4.proto << (best_delta)/2;
			break;
		default: relax_tuple(min_tuple, is_ip6, 1);
			break;
	}

	min_tuple->pkt.is_nonfirst_fragment = 0;
        u32 new_mask_type_index = assign_mask_type_index(am, min_tuple);

	hash_applied_mask_info_t **hash_applied_mask_info_vec = vec_elt_at_index(am->hash_applied_mask_info_vec_by_lc_index, lc_index);

	hash_applied_mask_info_t *minfo;
	//search in order pool if mask_type_index is already there
	int search;
	for (search=0; search < vec_len((*hash_applied_mask_info_vec)); search++){
		minfo = vec_elt_at_index((*hash_applied_mask_info_vec), search);
		if(minfo->mask_type_index == new_mask_type_index)
			break;
	}

	vec_validate((*hash_applied_mask_info_vec), search);
	minfo = vec_elt_at_index((*hash_applied_mask_info_vec), search);
	minfo->mask_type_index = new_mask_type_index;
	minfo->num_entries = 0;
	minfo->max_collisions = 0;
	minfo->first_rule_index = ~0;

	DBG( "TM-split_partition - mask type index-assigned!! -> %d", new_mask_type_index);

	if(coll_mask_type_index == new_mask_type_index){
		//vlib_cli_output(vm, "TM-There are collisions over threshold, but i'm not able to split! %d %d", coll_mask_type_index, new_mask_type_index);
		return;
	}


	/* populate new partition */
	DBG( "TM-Populate new partition");
	u32 r_ace_index = first_index;

//	for(i=0; i<collisions; i++){
	for(r_ace_index=0; r_ace_index < vec_len((*applied_hash_aces)); r_ace_index++) {

		applied_hash_ace_entry_t *pop_pae = vec_elt_at_index((*applied_hash_aces), r_ace_index);
		DBG( "TM-Population-collision: base_ace:%d (ace_mask:%d, first_collision_mask:%d)",
				pop_pae->ace_index, pop_pae->mask_type_index, coll_mask_type_index);

		if(pop_pae->mask_type_index != coll_mask_type_index) continue;
		u32 next_index = pop_pae->next_applied_entry_index;

		ace_info = vec_elt_at_index(ha->rules, pop_pae->hash_ace_info_index);
		mte = vec_elt_at_index(am->ace_mask_type_pool, ace_info->base_mask_type_index);
		//can insert rule?
		//mte = vec_elt_at_index(am->ace_mask_type_pool, pop_pae->mask_type_index);
		fa_5tuple_t *pop_mask = &mte->mask;

		if(!first_mask_contains_second_mask(is_ip6, min_tuple, pop_mask)) continue;
		DBG( "TM-new partition can insert -> applied_ace:%d", r_ace_index);

		//delete and insert in new format
		deactivate_applied_ace_hash_entry(am, lc_index, applied_hash_aces, r_ace_index);

		/* insert the new entry */
		pop_pae->mask_type_index = new_mask_type_index;

		activate_applied_ace_hash_entry(am, lc_index, applied_hash_aces, r_ace_index);

		r_ace_index = next_index;
	}

	DBG( "TM-Populate new partition-END");
	DBG( "TM-split_partition - END");

}