summaryrefslogtreecommitdiffstats
path: root/plugins/snat-plugin/snat/snat.c
blob: 3fd9ecb41b7e026c89949eecbd623c97688273ba (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
/*
 * snat.c - simple nat plugin
 *
 * Copyright (c) 2016 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 <vnet/vnet.h>
#include <vnet/plugin/plugin.h>
#include <vlibapi/api.h>
#include <snat/snat.h>

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

snat_main_t snat_main;

/* define message IDs */
#include <snat/snat_msg_enum.h>

/* define message structures */
#define vl_typedefs
#include <snat/snat_all_api_h.h> 
#undef vl_typedefs

/* define generated endian-swappers */
#define vl_endianfun
#include <snat/snat_all_api_h.h> 
#undef vl_endianfun

#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)

/* Get the API version number */
#define vl_api_version(n,v) static u32 api_version=(v);
#include <snat/snat_all_api_h.h>
#undef vl_api_version

/* Macro to finish up custom dump fns */
#define FINISH                                  \
    vec_add1 (s, 0);                            \
    vl_print (handle, (char *)s);               \
    vec_free (s);                               \
    return handle;

/* 
 * A handy macro to set up a message reply.
 * Assumes that the following variables are available:
 * mp - pointer to request message
 * rmp - pointer to reply message type
 * rv - return value
 */

#define REPLY_MACRO(t)                                          \
do {                                                            \
    unix_shared_memory_queue_t * q =                            \
    vl_api_client_index_to_input_queue (mp->client_index);      \
    if (!q)                                                     \
        return;                                                 \
                                                                \
    rmp = vl_msg_api_alloc (sizeof (*rmp));                     \
    rmp->_vl_msg_id = ntohs((t)+sm->msg_id_base);               \
    rmp->context = mp->context;                                 \
    rmp->retval = ntohl(rv);                                    \
                                                                \
    vl_msg_api_send_shmem (q, (u8 *)&rmp);                      \
} while(0);

#define REPLY_MACRO2(t, body)                                   \
do {                                                            \
    unix_shared_memory_queue_t * q =                            \
    vl_api_client_index_to_input_queue (mp->client_index);      \
    if (!q)                                                     \
        return;                                                 \
                                                                \
    rmp = vl_msg_api_alloc (sizeof (*rmp));                     \
    rmp->_vl_msg_id = ntohs((t)+sm->msg_id_base);               \
    rmp->context = mp->context;                                 \
    rmp->retval = ntohl(rv);                                    \
    do {body;} while (0);                                       \
    vl_msg_api_send_shmem (q, (u8 *)&rmp);                      \
} while(0);


/* Hook up input features */
VNET_IP4_UNICAST_FEATURE_INIT (ip4_snat_in2out, static) = {
  .node_name = "snat-in2out",
  .runs_before = (char *[]){"snat-out2in", 0},
  .feature_index = &snat_main.rx_feature_in2out,
};
VNET_IP4_UNICAST_FEATURE_INIT (ip4_snat_out2in, static) = {
  .node_name = "snat-out2in",
  .runs_before = (char *[]){"ip4-lookup", 0},
  .feature_index = &snat_main.rx_feature_out2in,
};
VNET_IP4_UNICAST_FEATURE_INIT (ip4_snat_in2out_fast, static) = {
  .node_name = "snat-in2out-fast",
  .runs_before = (char *[]){"snat-out2in-fast", 0},
  .feature_index = &snat_main.rx_feature_in2out_fast,
};
VNET_IP4_UNICAST_FEATURE_INIT (ip4_snat_out2in_fast, static) = {
  .node_name = "snat-out2in-fast",
  .runs_before = (char *[]){"ip4-lookup", 0},
  .feature_index = &snat_main.rx_feature_out2in_fast,
};


/* 
 * This routine exists to convince the vlib plugin framework that
 * we haven't accidentally copied a random .dll into the plugin directory.
 *
 * Also collects global variable pointers passed from the vpp engine
 */

clib_error_t * 
vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h,
                      int from_early_init)
{
  snat_main_t * sm = &snat_main;
  clib_error_t * error = 0;

  sm->vlib_main = vm;
  sm->vnet_main = h->vnet_main;
  sm->ethernet_main = h->ethernet_main;

  return error;
}

/*$$$$$ move to an installed header file */
#if (1 || CLIB_DEBUG > 0)       /* "trust, but verify" */

#define VALIDATE_SW_IF_INDEX(mp)				\
 do { u32 __sw_if_index = ntohl(mp->sw_if_index);		\
    vnet_main_t *__vnm = vnet_get_main();                       \
    if (pool_is_free_index(__vnm->interface_main.sw_interfaces, \
                           __sw_if_index)) {                    \
        rv = VNET_API_ERROR_INVALID_SW_IF_INDEX;                \
        goto bad_sw_if_index;                                   \
    }                                                           \
} while(0);

#define BAD_SW_IF_INDEX_LABEL                   \
do {                                            \
bad_sw_if_index:                                \
    ;                                           \
} while (0);

#define VALIDATE_RX_SW_IF_INDEX(mp)				\
 do { u32 __rx_sw_if_index = ntohl(mp->rx_sw_if_index);		\
    vnet_main_t *__vnm = vnet_get_main();                       \
    if (pool_is_free_index(__vnm->interface_main.sw_interfaces, \
                           __rx_sw_if_index)) {			\
        rv = VNET_API_ERROR_INVALID_SW_IF_INDEX;                \
        goto bad_rx_sw_if_index;				\
    }                                                           \
} while(0);

#define BAD_RX_SW_IF_INDEX_LABEL		\
do {                                            \
bad_rx_sw_if_index:				\
    ;                                           \
} while (0);

#define VALIDATE_TX_SW_IF_INDEX(mp)				\
 do { u32 __tx_sw_if_index = ntohl(mp->tx_sw_if_index);		\
    vnet_main_t *__vnm = vnet_get_main();                       \
    if (pool_is_free_index(__vnm->interface_main.sw_interfaces, \
                           __tx_sw_if_index)) {			\
        rv = VNET_API_ERROR_INVALID_SW_IF_INDEX;                \
        goto bad_tx_sw_if_index;				\
    }                                                           \
} while(0);

#define BAD_TX_SW_IF_INDEX_LABEL		\
do {                                            \
bad_tx_sw_if_index:				\
    ;                                           \
} while (0);

#else

#define VALIDATE_SW_IF_INDEX(mp)
#define BAD_SW_IF_INDEX_LABEL
#define VALIDATE_RX_SW_IF_INDEX(mp)
#define BAD_RX_SW_IF_INDEX_LABEL
#define VALIDATE_TX_SW_IF_INDEX(mp)
#define BAD_TX_SW_IF_INDEX_LABEL

#endif  /* CLIB_DEBUG > 0 */

void snat_add_address (snat_main_t *sm, ip4_address_t *addr)
{
  snat_address_t * ap;

  vec_add2 (sm->addresses, ap, 1);
  ap->addr = *addr;

}

static void increment_v4_address (ip4_address_t * a)
{
  u32 v;
  
  v = clib_net_to_host_u32(a->as_u32) + 1;
  a->as_u32 = clib_host_to_net_u32(v);
}

/**
 * @brief Add static mapping.
 *
 * Create static mapping between local addr+port and external addr+port.
 *
 * @param l_addr Local IPv4 address.
 * @param e_addr External IPv4 address.
 * @param l_port Local port number.
 * @param e_port External port number.
 * @param vrf_id VRF ID.
 * @param addr_only If 0 address port and pair mapping, otherwise address only.
 * @param is_add If 0 delete static mapping, otherwise add.
 *
 * @returns
 */
int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
                            u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
                            int is_add)
{
  snat_main_t * sm = &snat_main;
  snat_static_mapping_t *m;
  snat_static_mapping_key_t m_key;
  clib_bihash_kv_8_8_t kv, value;
  snat_address_t *a = 0;
  u32 fib_index = ~0;
  uword * p;
  int i;

  m_key.addr = e_addr;
  m_key.port = addr_only ? 0 : e_port;
  m_key.pad = 0;
  kv.key = m_key.as_u64;
  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
    m = 0;
  else
    m = pool_elt_at_index (sm->static_mappings, value.value);

  if (is_add)
    {
      if (m)
        return VNET_API_ERROR_VALUE_EXIST;

      /* Convert VRF id to FIB index */
      if (vrf_id != ~0)
        {
          p = hash_get (sm->ip4_main->fib_index_by_table_id, vrf_id);
          if (!p)
            return VNET_API_ERROR_NO_SUCH_FIB;
          fib_index = p[0];
        }
      /* If not specified use inside VRF id from SNAT plugin startup config */
      else
        {
          if (sm->inside_fib_index == ~0)
            {
              p = hash_get (sm->ip4_main->fib_index_by_table_id, sm->inside_vrf_id);
              if (!p)
                return VNET_API_ERROR_NO_SUCH_FIB;
              fib_index = p[0];
              sm->inside_fib_index = fib_index;
            }
          else
            fib_index = sm->inside_fib_index;

          vrf_id = sm->inside_vrf_id;
        }

      /* If outside FIB index is not resolved yet */
      if (sm->outside_fib_index == ~0)
        {
          p = hash_get (sm->ip4_main->fib_index_by_table_id, sm->outside_vrf_id);
          if (!p)
            return VNET_API_ERROR_NO_SUCH_FIB;
          sm->outside_fib_index = p[0];
        }

      /* Find external address in allocated addresses and reserve port for
         address and port pair mapping when dynamic translations enabled */
      if (!addr_only && !(sm->static_mapping_only))
        {
          for (i = 0; i < vec_len (sm->addresses); i++)
            {
              if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
                {
                  a = sm->addresses + i;
                  /* External port must be unused */
                  if (clib_bitmap_get (a->busy_port_bitmap, e_port))
                    return VNET_API_ERROR_INVALID_VALUE;
                  a->busy_port_bitmap = clib_bitmap_set (a->busy_port_bitmap,
                                                         e_port, 1);
                  if (e_port > 1024)
                    a->busy_ports++;

                  break;
                }
            }
          /* External address must be allocated */
          if (!a)
            return VNET_API_ERROR_NO_SUCH_ENTRY;
        }

      pool_get (sm->static_mappings, m);
      memset (m, 0, sizeof (*m));
      m->local_addr = l_addr;
      m->external_addr = e_addr;
      m->addr_only = addr_only;
      m->vrf_id = vrf_id;
      m->fib_index = fib_index;
      if (!addr_only)
        {
          m->local_port = l_port;
          m->external_port = e_port;
        }

      m_key.addr = m->local_addr;
      m_key.port = m->local_port;
      m_key.pad = 0;
      kv.key = m_key.as_u64;
      kv.value = m - sm->static_mappings;
      clib_bihash_add_del_8_8(&sm->static_mapping_by_local, &kv, 1);

      m_key.addr = m->external_addr;
      m_key.port = m->external_port;
      kv.key = m_key.as_u64;
      kv.value = m - sm->static_mappings;
      clib_bihash_add_del_8_8(&sm->static_mapping_by_external, &kv, 1);
    }
  else
    {
      if (!m)
        return VNET_API_ERROR_NO_SUCH_ENTRY;

      /* Free external address port */
      if (!addr_only && !(sm->static_mapping_only))
        {
          for (i = 0; i < vec_len (sm->addresses); i++)
            {
              if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
                {
                  a = sm->addresses + i;
                  a->busy_port_bitmap = clib_bitmap_set (a->busy_port_bitmap,
                                                         e_port, 0);
                  a->busy_ports--;

                  break;
                }
            }
        }

      m_key.addr = m->local_addr;
      m_key.port = m->local_port;
      m_key.pad = 0;
      kv.key = m_key.as_u64;
      clib_bihash_add_del_8_8(&sm->static_mapping_by_local, &kv, 0);

      m_key.addr = m->external_addr;
      m_key.port = m->external_port;
      kv.key = m_key.as_u64;
      clib_bihash_add_del_8_8(&sm->static_mapping_by_external, &kv, 0);

      /* Delete session(s) for static mapping if exist */
      if (!(sm->static_mapping_only) ||
          (sm->static_mapping_only && sm->static_mapping_connection_tracking))
        {
          snat_user_key_t u_key;
          snat_user_t *u;
          dlist_elt_t * head, * elt;
          u32 elt_index, head_index;
          u32 ses_index;
          snat_session_t * s;

          u_key.addr = m->local_addr;
          u_key.fib_index = m->fib_index;
          kv.key = u_key.as_u64;
          if (!clib_bihash_search_8_8 (&sm->user_hash, &kv, &value))
            {
              u = pool_elt_at_index (sm->users, value.value);
              if (u->nstaticsessions)
                {
                  head_index = u->sessions_per_user_list_head_index;
                  head = pool_elt_at_index (sm->list_pool, head_index);
                  elt_index = head->next;
                  elt = pool_elt_at_index (sm->list_pool, elt_index);
                  ses_index = elt->value;
                  while (ses_index != ~0)
                    {
                      s =  pool_elt_at_index (sm->sessions, ses_index);

                      if (!addr_only)
                        {
                          if ((s->out2in.addr.as_u32 != e_addr.as_u32) &&
                              (clib_net_to_host_u16 (s->out2in.port) != e_port))
                            continue;
                        }
                      value.key = s->in2out.as_u64;
                      clib_bihash_add_del_8_8 (&sm->in2out, &value, 0);
                      value.key = s->out2in.as_u64;
                      clib_bihash_add_del_8_8 (&sm->out2in, &value, 0);
                      pool_put (sm->sessions, s);

                      if (!addr_only)
                        break;

                      elt_index = elt->next;
                      elt = pool_elt_at_index (sm->list_pool, elt_index);
                      ses_index = elt->value;
                    }
                  if (addr_only)
                    {
                      while ((elt_index = clib_dlist_remove_head(sm->list_pool, head_index)) != ~0)
                        pool_put_index (sm->list_pool, elt_index);
                      pool_put (sm->users, u);
                      clib_bihash_add_del_8_8 (&sm->user_hash, &kv, 0);
                    }
                  else
                    {
                      if (ses_index != ~0)
                        {
                          clib_dlist_remove (sm->list_pool, elt_index);
                          pool_put (sm->list_pool, elt);
                          u->nstaticsessions--;
                        }
                    }
                }
            }
        }

      /* Delete static mapping from pool */
      pool_put (sm->static_mappings, m);
    }

  return 0;
}

static void 
vl_api_snat_add_address_range_t_handler
(vl_api_snat_add_address_range_t * mp)
{
  snat_main_t * sm = &snat_main;
  vl_api_snat_add_address_range_reply_t * rmp;
  ip4_address_t this_addr;
  u32 start_host_order, end_host_order;
  int i, count;
  int rv = 0;
  u32 * tmp;

  if (mp->is_ip4 != 1)
    {
      rv = VNET_API_ERROR_UNIMPLEMENTED;
      goto send_reply;
    }

  if (sm->static_mapping_only)
    {
      rv = VNET_API_ERROR_FEATURE_DISABLED;
      goto send_reply;
    }

  tmp = (u32 *) mp->first_ip_address;
  start_host_order = clib_host_to_net_u32 (tmp[0]);
  tmp = (u32 *) mp->last_ip_address;
  end_host_order = clib_host_to_net_u32 (tmp[0]);

  count = (end_host_order - start_host_order) + 1;

  if (count > 1024)
    clib_warning ("%U - %U, %d addresses...",
                  format_ip4_address, mp->first_ip_address,
                  format_ip4_address, mp->last_ip_address,
                  count);
  
  memcpy (&this_addr.as_u8, mp->first_ip_address, 4);

  for (i = 0; i < count; i++)
    {
      snat_add_address (sm, &this_addr);
      increment_v4_address (&this_addr);
    }

 send_reply:
  REPLY_MACRO (VL_API_SNAT_ADD_ADDRESS_RANGE_REPLY);
}

static void *vl_api_snat_add_address_range_t_print
(vl_api_snat_add_address_range_t *mp, void * handle)
{
  u8 * s;

  s = format (0, "SCRIPT: snat_add_address_range ");
  s = format (s, "%U ", format_ip4_address, mp->first_ip_address);
  if (memcmp (mp->first_ip_address, mp->last_ip_address, 4))
    {
      s = format (s, " - %U ", format_ip4_address, mp->last_ip_address);
    }
  FINISH;
}

static void
vl_api_snat_interface_add_del_feature_t_handler
(vl_api_snat_interface_add_del_feature_t * mp)
{
  snat_main_t * sm = &snat_main;
  vl_api_snat_interface_add_del_feature_reply_t * rmp;
  u8 is_del = mp->is_add == 0;
  u32 sw_if_index = ntohl(mp->sw_if_index);
  u32 ci;
  ip4_main_t * im = &ip4_main;
  ip_lookup_main_t * lm = &im->lookup_main;
  ip_config_main_t * rx_cm = &lm->feature_config_mains[VNET_IP_RX_UNICAST_FEAT];
  u32 feature_index;
  int rv = 0;

  VALIDATE_SW_IF_INDEX(mp);

  if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
    feature_index = mp->is_inside ?  sm->rx_feature_in2out_fast
      : sm->rx_feature_out2in_fast;
  else
    feature_index = mp->is_inside ? sm->rx_feature_in2out
      : sm->rx_feature_out2in;

  ci = rx_cm->config_index_by_sw_if_index[sw_if_index];
  ci = (is_del
        ? vnet_config_del_feature
        : vnet_config_add_feature)
    (sm->vlib_main, &rx_cm->config_main,
     ci,
     feature_index,
     0 /* config struct */, 
     0 /* sizeof config struct*/);
  rx_cm->config_index_by_sw_if_index[sw_if_index] = ci;
  
  BAD_SW_IF_INDEX_LABEL;

  REPLY_MACRO(VL_API_SNAT_INTERFACE_ADD_DEL_FEATURE_REPLY);
}

static void *vl_api_snat_interface_add_del_feature_t_print
(vl_api_snat_interface_add_del_feature_t * mp, void *handle)
{
  u8 * s;

  s = format (0, "SCRIPT: snat_interface_add_del_feature ");
  s = format (s, "sw_if_index %d %s %s",
              clib_host_to_net_u32(mp->sw_if_index),
              mp->is_inside ? "in":"out",
              mp->is_add ? "" : "del");

  FINISH;
}

static void
vl_api_snat_add_static_mapping_t_handler
(vl_api_snat_add_static_mapping_t * mp)
{
  snat_main_t * sm = &snat_main;
  vl_api_snat_add_static_mapping_reply_t * rmp;
  ip4_address_t local_addr, external_addr;
  u16 local_port = 0, external_port = 0;
  u32 vrf_id;
  int rv = 0;

  if (mp->is_ip4 != 1)
    {
      rv = VNET_API_ERROR_UNIMPLEMENTED;
      goto send_reply;
    }

  memcpy (&local_addr.as_u8, mp->local_ip_address, 4);
  memcpy (&external_addr.as_u8, mp->external_ip_address, 4);
  if (mp->addr_only == 0)
    {
      local_port = clib_net_to_host_u16 (mp->local_port);
      external_port = clib_net_to_host_u16 (mp->external_port);
    }
  vrf_id = clib_net_to_host_u32 (mp->vrf_id);

  rv = snat_add_static_mapping(local_addr, external_addr, local_port,
                               external_port, vrf_id, mp->addr_only,
                               mp->is_add);

 send_reply:
  REPLY_MACRO (VL_API_SNAT_ADD_ADDRESS_RANGE_REPLY);
}

static void *vl_api_snat_add_static_mapping_t_print
(vl_api_snat_add_static_mapping_t *mp, void * handle)
{
  u8 * s;

  s = format (0, "SCRIPT: snat_add_static_mapping ");
  s = format (s, "local_addr %U external_addr %U ",
              format_ip4_address, mp->local_ip_address,
              format_ip4_address, mp->external_ip_address);

  if (mp->addr_only == 0)
    s = format (s, "local_port %d external_port %d ",
                clib_net_to_host_u16 (mp->local_port),
                clib_net_to_host_u16 (mp->external_port));

  if (mp->vrf_id != ~0)
    s = format (s, "vrf %d", clib_net_to_host_u32 (mp->vrf_id));

  FINISH;
}

static void
send_snat_static_mapping_details
(snat_static_mapping_t * m, unix_shared_memory_queue_t * q, u32 context)
{
  vl_api_snat_static_mapping_details_t *rmp;
  snat_main_t * sm = &snat_main;

  rmp = vl_msg_api_alloc (sizeof (*rmp));
  memset (rmp, 0, sizeof (*rmp));
  rmp->_vl_msg_id = ntohs (VL_API_SNAT_STATIC_MAPPING_DETAILS+sm->msg_id_base);
  rmp->is_ip4 = 1;
  rmp->addr_only = m->addr_only;
  clib_memcpy (rmp->local_ip_address, &(m->local_addr), 4);
  clib_memcpy (rmp->external_ip_address, &(m->external_addr), 4);
  rmp->local_port = htons (m->local_port);
  rmp->external_port = htons (m->external_port);
  rmp->vrf_id = htonl (m->vrf_id);
  rmp->context = context;

  vl_msg_api_send_shmem (q, (u8 *) & rmp);
}

static void
vl_api_snat_static_mapping_dump_t_handler
(vl_api_snat_static_mapping_dump_t * mp)
{
  unix_shared_memory_queue_t *q;
  snat_main_t * sm = &snat_main;
  snat_static_mapping_t * m;

  q = vl_api_client_index_to_input_queue (mp->client_index);
  if (q == 0)
    return;

  pool_foreach (m, sm->static_mappings,
  ({
      send_snat_static_mapping_details (m, q, mp->context);
  }));
}

static void *vl_api_snat_static_mapping_dump_t_print
(vl_api_snat_static_mapping_dump_t *mp, void * handle)
{
  u8 *s;

  s = format (0, "SCRIPT: snat_static_mapping_dump ");

  FINISH;
}

static void
vl_api_snat_control_ping_t_handler
(vl_api_snat_control_ping_t * mp)
{
  vl_api_snat_control_ping_reply_t *rmp;
  snat_main_t * sm = &snat_main;
  int rv = 0;

  REPLY_MACRO2(VL_API_SNAT_CONTROL_PING_REPLY,
  ({
    rmp->vpe_pid = ntohl (getpid());
  }));
}

static void *vl_api_snat_control_ping_t_print
(vl_api_snat_control_ping_t *mp, void * handle)
{
  u8 *s;

  s = format (0, "SCRIPT: snat_control_ping ");

  FINISH;
}

static void
vl_api_snat_show_config_t_handler
(vl_api_snat_show_config_t * mp)
{
  vl_api_snat_show_config_reply_t *rmp;
  snat_main_t * sm = &snat_main;
  int rv = 0;

  REPLY_MACRO2(VL_API_SNAT_SHOW_CONFIG_REPLY,
  ({
    rmp->translation_buckets = htons (sm->translation_buckets);
    rmp->translation_memory_size = htons (sm->translation_memory_size);
    rmp->user_buckets = htons (sm->user_buckets);
    rmp->user_memory_size = htons (sm->user_memory_size);
    rmp->max_translations_per_user = htons (sm->max_translations_per_user);
    rmp->outside_vrf_id = htons (sm->outside_vrf_id);
    rmp->inside_vrf_id = htons (sm->inside_vrf_id);
    rmp->static_mapping_only = sm->static_mapping_only;
    rmp->static_mapping_connection_tracking =
      sm->static_mapping_connection_tracking;
  }));
}

static void *vl_api_snat_show_config_t_print
(vl_api_snat_show_config_t *mp, void * handle)
{
  u8 *s;

  s = format (0, "SCRIPT: snat_show_config ");

  FINISH;
}

/* List of message types that this plugin understands */
#define foreach_snat_plugin_api_msg                                     \
_(SNAT_ADD_ADDRESS_RANGE, snat_add_address_range)                       \
_(SNAT_INTERFACE_ADD_DEL_FEATURE, snat_interface_add_del_feature)       \
_(SNAT_ADD_STATIC_MAPPING, snat_add_static_mapping)                     \
_(SNAT_CONTROL_PING, snat_control_ping)                                 \
_(SNAT_STATIC_MAPPING_DUMP, snat_static_mapping_dump)                   \
_(SNAT_SHOW_CONFIG, snat_show_config)

/* Set up the API message handling tables */
static clib_error_t *
snat_plugin_api_hookup (vlib_main_t *vm)
{
   snat_main_t * sm __attribute__ ((unused)) = &snat_main;
#define _(N,n)                                                  \
    vl_msg_api_set_handlers((VL_API_##N + sm->msg_id_base),     \
                           #n,					\
                           vl_api_##n##_t_handler,              \
                           vl_noop_handler,                     \
                           vl_api_##n##_t_endian,               \
                           vl_api_##n##_t_print,                \
                           sizeof(vl_api_##n##_t), 1); 
    foreach_snat_plugin_api_msg;
#undef _

    return 0;
}

static void plugin_custom_dump_configure (snat_main_t * sm) 
{
#define _(n,f) sm->api_main->msg_print_handlers \
  [VL_API_##n + sm->msg_id_base]                \
    = (void *) vl_api_##f##_t_print;
  foreach_snat_plugin_api_msg;
#undef _
}

static clib_error_t * snat_init (vlib_main_t * vm)
{
  snat_main_t * sm = &snat_main;
  clib_error_t * error = 0;
  ip4_main_t * im = &ip4_main;
  ip_lookup_main_t * lm = &im->lookup_main;
  u8 * name;

  name = format (0, "snat_%08x%c", api_version, 0);

  /* Ask for a correctly-sized block of API message decode slots */
  sm->msg_id_base = vl_msg_api_get_msg_ids 
      ((char *) name, VL_MSG_FIRST_AVAILABLE);

  sm->vlib_main = vm;
  sm->vnet_main = vnet_get_main();
  sm->ip4_main = im;
  sm->ip4_lookup_main = lm;
  sm->api_main = &api_main;

  error = snat_plugin_api_hookup (vm);
  plugin_custom_dump_configure (sm);
  vec_free(name);

  return error;
}

VLIB_INIT_FUNCTION (snat_init);

void snat_free_outside_address_and_port (snat_main_t * sm, 
                                         snat_session_key_t * k, 
                                         u32 address_index)
{
  snat_address_t *a;
  u16 port_host_byte_order = clib_net_to_host_u16 (k->port);
  
  ASSERT (address_index < vec_len (sm->addresses));

  a = sm->addresses + address_index;

  ASSERT (clib_bitmap_get (a->busy_port_bitmap, port_host_byte_order) == 1);

  a->busy_port_bitmap = clib_bitmap_set (a->busy_port_bitmap, 
                                         port_host_byte_order, 0);
  a->busy_ports--;
}  

/**
 * @brief Match SNAT static mapping.
 *
 * @param sm          SNAT main.
 * @param match       Address and port to match.
 * @param mapping     External or local address and port of the matched mapping.
 * @param by_external If 0 match by local address otherwise match by external
 *                    address.
 *
 * @returns 0 if match found otherwise 1.
 */
int snat_static_mapping_match (snat_main_t * sm,
                               snat_session_key_t match,
                               snat_session_key_t * mapping,
                               u8 by_external)
{
  clib_bihash_kv_8_8_t kv, value;
  snat_static_mapping_t *m;
  snat_static_mapping_key_t m_key;
  clib_bihash_8_8_t *mapping_hash = &sm->static_mapping_by_local;

  if (by_external)
    mapping_hash = &sm->static_mapping_by_external;

  m_key.addr = match.addr;
  m_key.port = clib_net_to_host_u16 (match.port);
  m_key.pad = 0;

  kv.key = m_key.as_u64;

  if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
    {
      /* Try address only mapping */
      m_key.port = 0;
      kv.key = m_key.as_u64;
      if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
        return 1;
    }

  m = pool_elt_at_index (sm->static_mappings, value.value);

  if (by_external)
    {
      mapping->addr = m->local_addr;
      /* Address only mapping doesn't change port */
      mapping->port = m->addr_only ? match.port
        : clib_host_to_net_u16 (m->local_port);
      mapping->fib_index = m->fib_index;
    }
  else
    {
      mapping->addr = m->external_addr;
      /* Address only mapping doesn't change port */
      mapping->port = m->addr_only ? match.port
        : clib_host_to_net_u16 (m->external_port);
      mapping->fib_index = sm->outside_fib_index;
    }

  return 0;
}

int snat_alloc_outside_address_and_port (snat_main_t * sm, 
                                         snat_session_key_t * k,
                                         u32 * address_indexp)
{
  int i;
  snat_address_t *a;
  u32 portnum;

  for (i = 0; i < vec_len (sm->addresses); i++)
    {
      if (sm->addresses[i].busy_ports < (65535-1024))
        {
          a = sm->addresses + i;

          while (1)
            {
              portnum = random_u32 (&sm->random_seed);
              portnum &= 0xFFFF;
              if (portnum < 1024)
                continue;
              if (clib_bitmap_get (a->busy_port_bitmap, portnum))
                continue;
              a->busy_port_bitmap = clib_bitmap_set (a->busy_port_bitmap,
                                                     portnum, 1);
              a->busy_ports++;
              /* Caller sets protocol and fib index */
              k->addr = a->addr;
              k->port = clib_host_to_net_u16(portnum);
              *address_indexp = i;
              return 0;
            }
        }
    }
  /* Totally out of translations to use... */
  return 1;
}


static clib_error_t *
add_address_command_fn (vlib_main_t * vm,
                        unformat_input_t * input,
                        vlib_cli_command_t * cmd)
{
  unformat_input_t _line_input, *line_input = &_line_input;
  snat_main_t * sm = &snat_main;
  ip4_address_t start_addr, end_addr, this_addr;
  u32 start_host_order, end_host_order;
  int i, count;

  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  if (unformat (line_input, "%U - %U",
                unformat_ip4_address, &start_addr,
                unformat_ip4_address, &end_addr))
    ;
  else if (unformat (line_input, "%U", unformat_ip4_address, &start_addr))
    end_addr = start_addr;
  else
    return clib_error_return (0, "unknown input '%U'", format_unformat_error,
      input);
  unformat_free (line_input);

  if (sm->static_mapping_only)
    return clib_error_return (0, "static mapping only mode");

  start_host_order = clib_host_to_net_u32 (start_addr.as_u32);
  end_host_order = clib_host_to_net_u32 (end_addr.as_u32);
  
  if (end_host_order < start_host_order)
    return clib_error_return (0, "end address less than start address");

  count = (end_host_order - start_host_order) + 1;

  if (count > 1024)
    clib_warning ("%U - %U, %d addresses...",
                  format_ip4_address, &start_addr,
                  format_ip4_address, &end_addr,
                  count);
  
  this_addr = start_addr;

  for (i = 0; i < count; i++)
    {
      snat_add_address (sm, &this_addr);
      increment_v4_address (&this_addr);
    }

  return 0;
}

VLIB_CLI_COMMAND (add_address_command, static) = {
  .path = "snat add address",
  .short_help = "snat add addresses <ip4-range-start> [- <ip4-range-end>]",
  .function = add_address_command_fn,
};

static clib_error_t *
snat_feature_command_fn (vlib_main_t * vm,
                          unformat_input_t * input,
                          vlib_cli_command_t * cmd)
{
  unformat_input_t _line_input, *line_input = &_line_input;
  vnet_main_t * vnm = vnet_get_main();
  snat_main_t * sm = &snat_main;
  ip4_main_t * im = &ip4_main;
  ip_lookup_main_t * lm = &im->lookup_main;
  ip_config_main_t * rx_cm = &lm->feature_config_mains[VNET_IP_RX_UNICAST_FEAT];
  clib_error_t * error = 0;
  u32 sw_if_index, ci;
  u32 feature_index;
  u32 * inside_sw_if_indices = 0;
  u32 * outside_sw_if_indices = 0;
  int is_del = 0;
  int i;

  sw_if_index = ~0;

  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (line_input, "in %U", unformat_vnet_sw_interface,
                    vnm, &sw_if_index))
        vec_add1 (inside_sw_if_indices, sw_if_index);
      else if (unformat (line_input, "out %U", unformat_vnet_sw_interface,
                         vnm, &sw_if_index))
        vec_add1 (outside_sw_if_indices, sw_if_index);
      else if (unformat (line_input, "del"))
        is_del = 1;
      else
        return clib_error_return (0, "unknown input '%U'",
          format_unformat_error, input);
    }
  unformat_free (line_input);

  if (vec_len (inside_sw_if_indices))
    {
      if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
        feature_index = sm->rx_feature_in2out_fast;
      else
        feature_index = sm->rx_feature_in2out;

      for (i = 0; i < vec_len(inside_sw_if_indices); i++)
        {
          sw_if_index = inside_sw_if_indices[i];
          ci = rx_cm->config_index_by_sw_if_index[sw_if_index];
          ci = (is_del
                ? vnet_config_del_feature
                : vnet_config_add_feature)
            (vm, &rx_cm->config_main,
             ci,
             feature_index,
             0 /* config struct */, 
             0 /* sizeof config struct*/);
          rx_cm->config_index_by_sw_if_index[sw_if_index] = ci;
        }
    }

  if (vec_len (outside_sw_if_indices))
    {
      if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
        feature_index = sm->rx_feature_out2in_fast;
      else
        feature_index = sm->rx_feature_out2in;

      for (i = 0; i < vec_len(outside_sw_if_indices); i++)
        {
          sw_if_index = outside_sw_if_indices[i];
          ci = rx_cm->config_index_by_sw_if_index[sw_if_index];
          ci = (is_del
                ? vnet_config_del_feature
                : vnet_config_add_feature)
            (vm, &rx_cm->config_main,
             ci,
             feature_index,
             0 /* config struct */, 
             0 /* sizeof config struct*/);
          rx_cm->config_index_by_sw_if_index[sw_if_index] = ci;
        }
    }

  vec_free (inside_sw_if_indices);
  vec_free (outside_sw_if_indices);

  return error;
}

VLIB_CLI_COMMAND (set_interface_snat_command, static) = {
  .path = "set interface snat",
  .function = snat_feature_command_fn,
  .short_help = "set interface snat in <intfc> out <intfc> [del]",
};

static clib_error_t *
add_static_mapping_command_fn (vlib_main_t * vm,
                               unformat_input_t * input,
                               vlib_cli_command_t * cmd)
{
  unformat_input_t _line_input, *line_input = &_line_input;
  clib_error_t * error = 0;
  ip4_address_t l_addr, e_addr;
  u32 l_port = 0, e_port = 0, vrf_id = ~0;
  int is_add = 1;
  int addr_only = 1;
  int rv;

  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (line_input, "local %U %u", unformat_ip4_address, &l_addr,
                    &l_port))
        addr_only = 0;
      else if (unformat (line_input, "local %U", unformat_ip4_address, &l_addr))
        ;
      else if (unformat (line_input, "external %U %u", unformat_ip4_address,
                         &e_addr, &e_port))
        addr_only = 0;
      else if (unformat (line_input, "external %U", unformat_ip4_address,
                         &e_addr))
        ;
      else if (unformat (line_input, "vrf %u", &vrf_id))
        ;
      else if (unformat (line_input, "del"))
        is_add = 0;
      else
        return clib_error_return (0, "unknown input: '%U'",
          format_unformat_error, line_input);
    }
  unformat_free (line_input);

  rv = snat_add_static_mapping(l_addr, e_addr, (u16) l_port, (u16) e_port,
                               vrf_id, addr_only, is_add);

  switch (rv)
    {
    case VNET_API_ERROR_INVALID_VALUE:
      return clib_error_return (0, "External port already in use.");
      break;
    case VNET_API_ERROR_NO_SUCH_ENTRY:
      if (is_add)
        return clib_error_return (0, "External addres must be allocated.");
      else
        return clib_error_return (0, "Mapping not exist.");
      break;
    case VNET_API_ERROR_NO_SUCH_FIB:
      return clib_error_return (0, "No such VRF id.");
    case VNET_API_ERROR_VALUE_EXIST:
      return clib_error_return (0, "Mapping already exist.");
    default:
      break;
    }

  return error;
}

/*?
 * @cliexpar
 * @cliexstart{snat add static mapping}
 * Static mapping allows hosts on the external network to initiate connection
 * to to the local network host.
 * To create static mapping between local host address 10.0.0.3 port 6303 and
 * external address 4.4.4.4 port 3606 use:
 *  vpp# snat add static mapping local 10.0.0.3 6303 external 4.4.4.4 3606
 * If not runnig "static mapping only" S-NAT plugin mode use before:
 *  vpp# snat add address 4.4.4.4
 * To create static mapping between local and external address use:
 *  vpp# snat add static mapping local 10.0.0.3 external 4.4.4.4
 * @cliexend
?*/
VLIB_CLI_COMMAND (add_static_mapping_command, static) = {
  .path = "snat add static mapping",
  .function = add_static_mapping_command_fn,
  .short_help =
    "snat add static mapping local <addr> [<port>] external <addr> [<port>] [vrf <table-id>] [del]",
};

static clib_error_t *
snat_config (vlib_main_t * vm, unformat_input_t * input)
{
  snat_main_t * sm = &snat_main;
  u32 translation_buckets = 1024;
  u32 translation_memory_size = 128<<20;
  u32 user_buckets = 128;
  u32 user_memory_size = 64<<20;
  u32 max_translations_per_user = 100;
  u32 outside_vrf_id = 0;
  u32 inside_vrf_id = 0;
  u32 static_mapping_buckets = 1024;
  u32 static_mapping_memory_size = 64<<20;
  u8 static_mapping_only = 0;
  u8 static_mapping_connection_tracking = 0;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "translation hash buckets %d", &translation_buckets))
        ;
      else if (unformat (input, "translation hash memory %d",
                         &translation_memory_size));
      else if (unformat (input, "user hash buckets %d", &user_buckets))
        ;
      else if (unformat (input, "user hash memory %d",
                         &user_memory_size))
        ;
      else if (unformat (input, "max translations per user %d",
                         &max_translations_per_user))
        ;
      else if (unformat (input, "outside VRF id %d",
                         &outside_vrf_id))
        ;
      else if (unformat (input, "inside VRF id %d",
                         &inside_vrf_id))
        ;
      else if (unformat (input, "static mapping only"))
        {
          static_mapping_only = 1;
          if (unformat (input, "connection tracking"))
            static_mapping_connection_tracking = 1;
        }
      else 
	return clib_error_return (0, "unknown input '%U'",
				  format_unformat_error, input);
    }

  /* for show commands, etc. */
  sm->translation_buckets = translation_buckets;
  sm->translation_memory_size = translation_memory_size;
  sm->user_buckets = user_buckets;
  sm->user_memory_size = user_memory_size;
  sm->max_translations_per_user = max_translations_per_user;
  sm->outside_vrf_id = outside_vrf_id;
  sm->outside_fib_index = ~0;
  sm->inside_vrf_id = inside_vrf_id;
  sm->inside_fib_index = ~0;
  sm->static_mapping_only = static_mapping_only;
  sm->static_mapping_connection_tracking = static_mapping_connection_tracking;

  if (!static_mapping_only ||
      (static_mapping_only && static_mapping_connection_tracking))
    {
      clib_bihash_init_8_8 (&sm->in2out, "in2out", translation_buckets,
                            translation_memory_size);

      clib_bihash_init_8_8 (&sm->out2in, "out2in", translation_buckets,
                            translation_memory_size);

      clib_bihash_init_8_8 (&sm->user_hash, "users", user_buckets,
                            user_memory_size);
    }
  clib_bihash_init_8_8 (&sm->static_mapping_by_local,
                        "static_mapping_by_local", static_mapping_buckets,
                        static_mapping_memory_size);

  clib_bihash_init_8_8 (&sm->static_mapping_by_external,
                        "static_mapping_by_external", static_mapping_buckets,
                        static_mapping_memory_size);
  return 0;
}

VLIB_CONFIG_FUNCTION (snat_config, "snat");

u8 * format_snat_key (u8 * s, va_list * args)
{
  snat_session_key_t * key = va_arg (*args, snat_session_key_t *);
  char * protocol_string = "unknown";
  static char *protocol_strings[] = {
      "UDP",
      "TCP",
      "ICMP",
  };

  if (key->protocol < ARRAY_LEN(protocol_strings))
      protocol_string = protocol_strings[key->protocol];

  s = format (s, "%U proto %s port %d fib %d",
              format_ip4_address, &key->addr, protocol_string,
              clib_net_to_host_u16 (key->port), key->fib_index);
  return s;
}

u8 * format_snat_session (u8 * s, va_list * args)
{
  snat_main_t * sm __attribute__((unused)) = va_arg (*args, snat_main_t *);
  snat_session_t * sess = va_arg (*args, snat_session_t *);

  s = format (s, "  i2o %U\n", format_snat_key, &sess->in2out);
  s = format (s, "    o2i %U\n", format_snat_key, &sess->out2in);
  s = format (s, "       last heard %.2f\n", sess->last_heard);
  s = format (s, "       total pkts %d, total bytes %lld\n",
              sess->total_pkts, sess->total_bytes);
  if (snat_is_session_static (sess))
    s = format (s, "       static translation\n");
  else
    s = format (s, "       dynamic translation\n");

  return s;
}

u8 * format_snat_user (u8 * s, va_list * args)
{
  snat_main_t * sm = va_arg (*args, snat_main_t *);
  snat_user_t * u = va_arg (*args, snat_user_t *);
  int verbose = va_arg (*args, int);
  dlist_elt_t * head, * elt;
  u32 elt_index, head_index;
  u32 session_index;
  snat_session_t * sess;

  s = format (s, "%U: %d dynamic translations, %d static translations\n",
              format_ip4_address, &u->addr, u->nsessions, u->nstaticsessions);

  if (verbose == 0)
    return s;

  if (u->nsessions || u->nstaticsessions)
    {
      head_index = u->sessions_per_user_list_head_index;
      head = pool_elt_at_index (sm->list_pool, head_index);

      elt_index = head->next;
      elt = pool_elt_at_index (sm->list_pool, elt_index);
      session_index = elt->value;

      while (session_index != ~0)
        {
          sess = pool_elt_at_index (sm->sessions, session_index);

          s = format (s, "  %U\n", format_snat_session, sm, sess);

          elt_index = elt->next;
          elt = pool_elt_at_index (sm->list_pool, elt_index);
          session_index = elt->value;
        }
    }

  return s;
}

u8 * format_snat_static_mapping (u8 * s, va_list * args)
{
  snat_static_mapping_t *m = va_arg (*args, snat_static_mapping_t *);

  if (m->addr_only)
      s = format (s, "local %U external %U vrf %d",
                  format_ip4_address, &m->local_addr,
                  format_ip4_address, &m->external_addr,
                  m->vrf_id);
  else
      s = format (s, "local %U:%d external %U:%d vrf %d",
                  format_ip4_address, &m->local_addr, m->local_port,
                  format_ip4_address, &m->external_addr, m->external_port,
                  m->vrf_id);

  return s;
}

static clib_error_t *
show_snat_command_fn (vlib_main_t * vm,
		 unformat_input_t * input,
		 vlib_cli_command_t * cmd)
{
  int verbose = 0;
  snat_main_t * sm = &snat_main;
  snat_user_t * u;
  snat_static_mapping_t *m;

  if (unformat (input, "detail"))
    verbose = 1;
  else if (unformat (input, "verbose"))
    verbose = 2;

  if (sm->static_mapping_only)
    {
      if (sm->static_mapping_connection_tracking)
        vlib_cli_output (vm, "SNAT mode: static mapping only connection "
                         "tracking");
      else
        vlib_cli_output (vm, "SNAT mode: static mapping only");
    }
  else
    {
      vlib_cli_output (vm, "SNAT mode: dynamic translations enabled");
    }

  if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
    {
      vlib_cli_output (vm, "%d static mappings",
                       pool_elts (sm->static_mappings));

      if (verbose > 0)
        {
          pool_foreach (m, sm->static_mappings,
          ({
            vlib_cli_output (vm, "%U", format_snat_static_mapping, m);
          }));
        }
    }
  else
    {
      vlib_cli_output (vm, "%d users, %d outside addresses, %d active sessions,"
                       " %d static mappings",
                       pool_elts (sm->users),
                       vec_len (sm->addresses),
                       pool_elts (sm->sessions),
                       pool_elts (sm->static_mappings));

      if (verbose > 0)
        {
          vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->in2out,
                           verbose - 1);
          vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->out2in,
                           verbose - 1);
          vlib_cli_output (vm, "%d list pool elements",
                           pool_elts (sm->list_pool));

          pool_foreach (u, sm->users,
          ({
            vlib_cli_output (vm, "%U", format_snat_user, sm, u, verbose - 1);
          }));

          if (pool_elts (sm->static_mappings))
            {
              vlib_cli_output (vm, "static mappings:");
              pool_foreach (m, sm->static_mappings,
              ({
                vlib_cli_output (vm, "%U", format_snat_static_mapping, m);
              }));
            }
        }
    }

  return 0;
}

VLIB_CLI_COMMAND (show_snat_command, static) = {
    .path = "show snat",
    .short_help = "show snat",
    .function = show_snat_command_fn,
};