summaryrefslogtreecommitdiffstats
path: root/src/plugins/nat/nat44-ed/nat44_ed.h
blob: f8cd9a06bea84ce6257f678edde8c98d2bf096d1 (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
/*
 * Copyright (c) 2020 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.
 */
/**
 * @file nat.c
 * NAT plugin global declarations
 */
#ifndef __included_nat44_ed_h__
#define __included_nat44_ed_h__

#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/ip/icmp46_packet.h>
#include <vnet/api_errno.h>
#include <vnet/fib/fib_source.h>
#include <vppinfra/elog.h>
#include <vppinfra/bihash_8_8.h>
#include <vppinfra/bihash_16_8.h>
#include <vppinfra/hash.h>
#include <vppinfra/dlist.h>
#include <vppinfra/error.h>
#include <vlibapi/api.h>

#include <nat/lib/lib.h>
#include <nat/lib/inlines.h>

/* default number of worker handoff frame queue elements */
#define NAT_FQ_NELTS_DEFAULT 64

/* NAT buffer flags */
#define SNAT_FLAG_HAIRPINNING (1 << 0)

/* NAT44 API Configuration flags */
#define foreach_nat44_config_flag                                             \
  _ (0x00, IS_ENDPOINT_INDEPENDENT)                                           \
  _ (0x01, IS_ENDPOINT_DEPENDENT)                                             \
  _ (0x02, IS_STATIC_MAPPING_ONLY)                                            \
  _ (0x04, IS_CONNECTION_TRACKING)

typedef enum nat44_config_flags_t_
{
#define _(n,f) NAT44_API_##f = n,
  foreach_nat44_config_flag
#undef _
} nat44_config_flags_t;

typedef struct
{
  /* nat44 plugin features */
  u8 static_mapping_only;
  u8 connection_tracking;

  u32 inside_vrf;
  u32 outside_vrf;

  /* maximum number of sessions */
  u32 sessions;

} nat44_config_t;

typedef enum
{
  NAT_NEXT_DROP,
  NAT_NEXT_ICMP_ERROR,
  NAT_NEXT_IN2OUT_ED_FAST_PATH,
  NAT_NEXT_IN2OUT_ED_SLOW_PATH,
  NAT_NEXT_IN2OUT_ED_OUTPUT_FAST_PATH,
  NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH,
  NAT_NEXT_OUT2IN_ED_FAST_PATH,
  NAT_NEXT_OUT2IN_ED_SLOW_PATH,
  NAT_NEXT_IN2OUT_CLASSIFY,
  NAT_NEXT_OUT2IN_CLASSIFY,
  NAT_N_NEXT,
} nat_next_t;

typedef struct
{
  u32 next_index;
  u32 arc_next_index;
} nat_pre_trace_t;

/* External address and port allocation modes */
#define foreach_nat_addr_and_port_alloc_alg \
  _(0, DEFAULT, "default")         \
  _(1, MAPE, "map-e")              \
  _(2, RANGE, "port-range")

typedef enum
{
#define _(v, N, s) NAT_ADDR_AND_PORT_ALLOC_ALG_##N = v,
  foreach_nat_addr_and_port_alloc_alg
#undef _
} nat_addr_and_port_alloc_alg_t;

/* Session state */
#define foreach_snat_session_state          \
  _(0, UNKNOWN, "unknown")                 \
  _(1, UDP_ACTIVE, "udp-active")           \
  _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
  _(3, TCP_ESTABLISHED, "tcp-established") \
  _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
  _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
  _(6, TCP_CLOSING, "tcp-closing")         \
  _(7, TCP_LAST_ACK, "tcp-last-ack")       \
  _(8, TCP_CLOSED, "tcp-closed")           \
  _(9, ICMP_ACTIVE, "icmp-active")

typedef enum
{
#define _(v, N, s) SNAT_SESSION_##N = v,
  foreach_snat_session_state
#undef _
} snat_session_state_t;

#define foreach_nat_in2out_ed_error                                           \
  _ (UNSUPPORTED_PROTOCOL, "unsupported protocol")                            \
  _ (OUT_OF_PORTS, "out of ports")                                            \
  _ (BAD_ICMP_TYPE, "unsupported ICMP type")                                  \
  _ (MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")                      \
  _ (NON_SYN, "non-SYN packet try to create session")                         \
  _ (TCP_CLOSED, "drops due to TCP in transitory timeout")                    \
  _ (TRNSL_FAILED, "couldn't translate packet")

typedef enum
{
#define _(sym,str) NAT_IN2OUT_ED_ERROR_##sym,
  foreach_nat_in2out_ed_error
#undef _
    NAT_IN2OUT_ED_N_ERROR,
} nat_in2out_ed_error_t;

#define foreach_nat_out2in_ed_error                                           \
  _ (UNSUPPORTED_PROTOCOL, "unsupported protocol")                            \
  _ (OUT_OF_PORTS, "out of ports")                                            \
  _ (BAD_ICMP_TYPE, "unsupported ICMP type")                                  \
  _ (NO_TRANSLATION, "no translation")                                        \
  _ (MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")                      \
  _ (NON_SYN, "non-SYN packet try to create session")                         \
  _ (TCP_CLOSED, "drops due to TCP in transitory timeout")                    \
  _ (HASH_ADD_FAILED, "hash table add failed")                                \
  _ (TRNSL_FAILED, "couldn't translate packet")

typedef enum
{
#define _(sym,str) NAT_OUT2IN_ED_ERROR_##sym,
  foreach_nat_out2in_ed_error
#undef _
    NAT_OUT2IN_ED_N_ERROR,
} nat_out2in_ed_error_t;


/* Endpoint dependent TCP session state */
#define NAT44_SES_I2O_FIN 1
#define NAT44_SES_O2I_FIN 2
#define NAT44_SES_I2O_FIN_ACK 4
#define NAT44_SES_O2I_FIN_ACK 8
#define NAT44_SES_I2O_SYN 16
#define NAT44_SES_O2I_SYN 32
#define NAT44_SES_RST     64

/* Session flags */
#define SNAT_SESSION_FLAG_STATIC_MAPPING     (1 << 0)
#define SNAT_SESSION_FLAG_UNKNOWN_PROTO	     (1 << 1)
#define SNAT_SESSION_FLAG_LOAD_BALANCING     (1 << 2)
#define SNAT_SESSION_FLAG_TWICE_NAT	     (1 << 3)
#define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT (1 << 4)
#define SNAT_SESSION_FLAG_FWD_BYPASS	     (1 << 5)
#define SNAT_SESSION_FLAG_AFFINITY	     (1 << 6)
#define SNAT_SESSION_FLAG_EXACT_ADDRESS	     (1 << 7)
#define SNAT_SESSION_FLAG_HAIRPINNING	     (1 << 8)

/* NAT interface flags */
#define NAT_INTERFACE_FLAG_IS_INSIDE 1
#define NAT_INTERFACE_FLAG_IS_OUTSIDE 2

/* Static mapping flags */
#define NAT_SM_FLAG_SELF_TWICE_NAT (1 << 1)
#define NAT_SM_FLAG_TWICE_NAT	   (1 << 2)
#define NAT_SM_FLAG_IDENTITY_NAT   (1 << 3)
#define NAT_SM_FLAG_ADDR_ONLY	   (1 << 4)
#define NAT_SM_FLAG_EXACT_ADDRESS  (1 << 5)
#define NAT_SM_FLAG_OUT2IN_ONLY	   (1 << 6)
#define NAT_SM_FLAG_LB		   (1 << 7)
#define NAT_SM_FLAG_SWITCH_ADDRESS (1 << 8)

typedef CLIB_PACKED(struct
{
  // number of sessions in this vrf
  u32 ses_count;

  u32 rx_fib_index;
  u32 tx_fib_index;

  // is this vrf expired
  u8 expired;
}) per_vrf_sessions_t;

typedef union
{
  struct
  {
    ip4_address_t saddr, daddr;
    u16 sport; // ICMP id for ICMP case
    u16 dport;
    u32 fib_index : 24;
    u8 proto;
  };
  u64 as_u64[2];
  u64x2u as_u128;
} nat_6t_t;

STATIC_ASSERT_SIZEOF (nat_6t_t, 2 * sizeof (u64));

typedef struct
{
#define NAT_FLOW_OP_SADDR_REWRITE   (1 << 1)
#define NAT_FLOW_OP_SPORT_REWRITE   (1 << 2)
#define NAT_FLOW_OP_DADDR_REWRITE   (1 << 3)
#define NAT_FLOW_OP_DPORT_REWRITE   (1 << 4)
#define NAT_FLOW_OP_ICMP_ID_REWRITE (1 << 5)
#define NAT_FLOW_OP_TXFIB_REWRITE   (1 << 6)
  int ops;
  nat_6t_t match;
  struct
  {
    ip4_address_t saddr, daddr;
    u16 sport;
    u16 dport;
    u32 fib_index;
    u8 proto;
    u16 icmp_id;
  } rewrite;
  uword l3_csum_delta;
  uword l4_csum_delta;
} nat_6t_flow_t;

void nat44_ed_forwarding_enable_disable (u8 is_enable);

always_inline void
nat_6t_flow_saddr_rewrite_set (nat_6t_flow_t *f, u32 saddr)
{
  f->ops |= NAT_FLOW_OP_SADDR_REWRITE;
  f->rewrite.saddr.as_u32 = saddr;
}

always_inline void
nat_6t_flow_daddr_rewrite_set (nat_6t_flow_t *f, u32 daddr)
{
  f->ops |= NAT_FLOW_OP_DADDR_REWRITE;
  f->rewrite.daddr.as_u32 = daddr;
}

always_inline void
nat_6t_flow_sport_rewrite_set (nat_6t_flow_t *f, u32 sport)
{
  f->ops |= NAT_FLOW_OP_SPORT_REWRITE;
  f->rewrite.sport = sport;
}

always_inline void
nat_6t_flow_dport_rewrite_set (nat_6t_flow_t *f, u32 dport)
{
  f->ops |= NAT_FLOW_OP_DPORT_REWRITE;
  f->rewrite.dport = dport;
}

always_inline void
nat_6t_flow_txfib_rewrite_set (nat_6t_flow_t *f, u32 tx_fib_index)
{
  f->ops |= NAT_FLOW_OP_TXFIB_REWRITE;
  f->rewrite.fib_index = tx_fib_index;
}

always_inline void
nat_6t_flow_icmp_id_rewrite_set (nat_6t_flow_t *f, u16 id)
{
  f->ops |= NAT_FLOW_OP_ICMP_ID_REWRITE;
  f->rewrite.icmp_id = id;
}

typedef CLIB_PACKED(struct
{
  /* Outside network tuple */
  struct
  {
    ip4_address_t addr;
    u32 fib_index;
    u16 port;
  } out2in;

  /* Inside network tuple */
  struct
  {
    ip4_address_t addr;
    u32 fib_index;
    u16 port;
  } in2out;

  nat_protocol_t nat_proto;

  nat_6t_flow_t i2o;
  nat_6t_flow_t o2i;

  /* Flags */
  u32 flags;

  /* head of LRU list in which this session is tracked */
  u32 lru_head_index;
  /* index in global LRU list */
  u32 lru_index;
  f64 last_lru_update;

  /* Last heard timer */
  f64 last_heard;

  /* Last HA refresh */
  f64 ha_last_refreshed;

  /* Counters */
  u64 total_bytes;
  u32 total_pkts;

  /* External host address and port */
  ip4_address_t ext_host_addr;
  u16 ext_host_port;

  /* External host address and port after translation */
  ip4_address_t ext_host_nat_addr;
  u16 ext_host_nat_port;

  /* TCP session state */
  u8 state;
  u32 i2o_fin_seq;
  u32 o2i_fin_seq;
  u64 tcp_closed_timestamp;

  /* per vrf sessions index */
  u32 per_vrf_sessions_index;

  u32 thread_index;
}) snat_session_t;

typedef struct
{
  ip4_address_t addr;
  u32 fib_index;
#define _(N, i, n, s) \
  u32 busy_##n##_ports; \
  u32 * busy_##n##_ports_per_thread; \
  u32 busy_##n##_port_refcounts[65535];
  foreach_nat_protocol
#undef _
} snat_address_t;

typedef struct
{
  u32 fib_index;
  u32 ref_count;
} nat_fib_t;

typedef struct
{
  u32 fib_index;
  u32 refcount;
} nat_outside_fib_t;

typedef struct
{
  /* backend IP address */
  ip4_address_t addr;
  /* backend port number */
  u16 port;
  /* probability of the backend to be randomly matched */
  u8 probability;
  u8 prefix;
  /* backend FIB table */
  u32 vrf_id;
  u32 fib_index;
} nat44_lb_addr_port_t;

typedef enum
{
  /* twice-nat disabled */
  TWICE_NAT_DISABLED,
  /* twice-nat enabled */
  TWICE_NAT,
  /* twice-nat only when src IP equals dst IP after translation */
  TWICE_NAT_SELF,
} twice_nat_type_t;

typedef enum
{
  /* no load-balancing */
  NO_LB_NAT,
  /* load-balancing */
  LB_NAT,
  /* load-balancing with affinity */
  AFFINITY_LB_NAT,
} lb_nat_type_t;

typedef struct
{
  /* preferred pool address */
  ip4_address_t pool_addr;
  /* local IP address */
  ip4_address_t local_addr;
  /* external IP address */
  ip4_address_t external_addr;
  /* local port */
  u16 local_port;
  /* external port */
  u16 external_port;
  /* local FIB table */
  u32 vrf_id;
  u32 fib_index;
  /* protocol */
  nat_protocol_t proto;
  /* 0 = disabled, otherwise client IP affinity sticky time in seconds */
  u32 affinity;
  /* worker threads used by backends/local host */
  u32 *workers;
  /* opaque string tag */
  u8 *tag;
  /* backends for load-balancing mode */
  nat44_lb_addr_port_t *locals;
  /* affinity per service lis */
  u32 affinity_per_service_list_head_index;
  /* flags */
  u32 flags;
} snat_static_mapping_t;

typedef struct
{
  u32 sw_if_index;
  u8 flags;
} snat_interface_t;

typedef struct
{
  ip4_address_t l_addr;
  ip4_address_t pool_addr;
  u16 l_port;
  u16 e_port;
  u32 sw_if_index;
  u32 vrf_id;
  nat_protocol_t proto;
  u32 flags;
  int addr_only;
  int twice_nat;
  int out2in_only;
  int identity_nat;
  int exact;
  u8 *tag;
} snat_static_map_resolve_t;

typedef struct
{
  /* Session pool */
  snat_session_t *sessions;

  /* Pool of doubly-linked list elements */
  dlist_elt_t *list_pool;

  /* LRU session list - head is stale, tail is fresh */
  dlist_elt_t *lru_pool;
  u32 tcp_trans_lru_head_index;
  u32 tcp_estab_lru_head_index;
  u32 udp_lru_head_index;
  u32 icmp_lru_head_index;
  u32 unk_proto_lru_head_index;

  /* NAT thread index */
  u32 snat_thread_index;

  /* real thread index */
  u32 thread_index;

  per_vrf_sessions_t *per_vrf_sessions_vec;

} snat_main_per_thread_data_t;

struct snat_main_s;

u32 nat44_ed_get_in2out_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
				      u32 rx_fib_index, u8 is_output);
u32 nat44_ed_get_out2in_worker_index (vlib_buffer_t *b, ip4_header_t *ip,
				      u32 rx_fib_index, u8 is_output);

/* Return worker thread index for given packet */
/* NAT address and port allocation function */
typedef int (nat_alloc_out_addr_and_port_function_t) (snat_address_t *
						      addresses,
						      u32 fib_index,
						      u32 thread_index,
						      nat_protocol_t proto,
						      ip4_address_t * addr,
						      u16 * port,
						      u16 port_per_thread,
						      u32 snat_thread_index);

typedef struct snat_main_s
{
  /* Thread settings */
  u32 num_workers;
  u32 first_worker_index;
  u32 *workers;
  u16 port_per_thread;

  /* Per thread data */
  snat_main_per_thread_data_t *per_thread_data;

  /* Find a static mapping by local */
  clib_bihash_8_8_t static_mapping_by_local;

  /* Find a static mapping by external */
  clib_bihash_8_8_t static_mapping_by_external;

  /* Static mapping pool */
  snat_static_mapping_t *static_mappings;

  /* Endpoint independent lookup tables */
  clib_bihash_8_8_t in2out;
  clib_bihash_8_8_t out2in;

  /* Endpoint dependent lookup table */
  clib_bihash_16_8_t flow_hash;

  /* Interface pool */
  snat_interface_t *interfaces;
  snat_interface_t *output_feature_interfaces;

  /* Vector of outside addresses */
  snat_address_t *addresses;
  /* Vector of twice NAT addresses for external hosts */
  snat_address_t *twice_nat_addresses;

  /* sw_if_indices whose intfc addresses should be auto-added */
  u32 *auto_add_sw_if_indices;
  u32 *auto_add_sw_if_indices_twice_nat;

  /* Address and port allocation function */
  nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
  /* Address and port allocation type */
  nat_addr_and_port_alloc_alg_t addr_and_port_alloc_alg;
  /* Port set parameters (MAP-E) */
  u8 psid_offset;
  u8 psid_length;
  u16 psid;
  /* Port range parameters */
  u16 start_port;
  u16 end_port;

  /* vector of fibs */
  nat_fib_t *fibs;

  /* vector of outside fibs */
  nat_outside_fib_t *outside_fibs;

  /* vector of interface address static mappings to resolve. */
  snat_static_map_resolve_t *to_resolve;

  /* Randomize port allocation order */
  u32 random_seed;

  /* Worker handoff frame-queue index */
  u32 fq_in2out_index;
  u32 fq_in2out_output_index;
  u32 fq_out2in_index;

  u32 out2in_node_index;
  u32 in2out_node_index;
  u32 in2out_output_node_index;

  nat44_config_t rconfig;
  //nat44_config_t cconfig;

  /* If forwarding is enabled */
  u8 forwarding_enabled;

  /* static mapping config */
  u8 static_mapping_only;
  u8 static_mapping_connection_tracking;

  /* Is translation memory size calculated or user defined */
  u8 translation_memory_size_set;

  u32 translation_buckets;
  u32 max_translations_per_thread;
  u32 *max_translations_per_fib;

  u32 outside_vrf_id;
  u32 outside_fib_index;
  u32 inside_vrf_id;
  u32 inside_fib_index;

  nat_timeouts_t timeouts;

  /* TCP MSS clamping */
  u16 mss_clamping;

  /* counters */
  vlib_simple_counter_main_t total_sessions;
  u32 max_cfg_sessions_gauge; /* Index of max configured sessions gauge in
				 stats */

#define _(x) vlib_simple_counter_main_t x;
  struct
  {
    struct
    {
      struct
      {
	foreach_nat_counter;
      } in2out;

      struct
      {
	foreach_nat_counter;
      } out2in;
    } fastpath;

    struct
    {
      struct
      {
	foreach_nat_counter;
      } in2out;

      struct
      {
	foreach_nat_counter;
      } out2in;
    } slowpath;

    vlib_simple_counter_main_t hairpinning;
  } counters;
#undef _

  /* API message ID base */
  u16 msg_id_base;

  /* log class */
  vlib_log_class_t log_class;
  /* logging level */
  u8 log_level;

  /* convenience */
  api_main_t *api_main;
  ip4_main_t *ip4_main;
  ip_lookup_main_t *ip4_lookup_main;

  fib_source_t fib_src_hi;
  fib_source_t fib_src_low;

  /* pat - dynamic mapping enabled or conneciton tracking */
  u8 pat;

  /* number of worker handoff frame queue elements */
  u32 frame_queue_nelts;

  /* nat44 plugin enabled */
  u8 enabled;

  vnet_main_t *vnet_main;

} snat_main_t;

typedef struct
{
  u32 thread_index;
  f64 now;
} nat44_is_idle_session_ctx_t;

typedef struct
{
  u32 cached_sw_if_index;
  uword *cached_presence_by_ip4_address;
} snat_runtime_t;

extern snat_main_t snat_main;

// nat pre ed next_node feature classification
extern vlib_node_registration_t nat_default_node;
extern vlib_node_registration_t nat_pre_in2out_node;
extern vlib_node_registration_t nat_pre_out2in_node;

extern vlib_node_registration_t snat_in2out_node;
extern vlib_node_registration_t snat_in2out_output_node;
extern vlib_node_registration_t snat_out2in_node;
extern vlib_node_registration_t snat_in2out_worker_handoff_node;
extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
extern vlib_node_registration_t snat_out2in_worker_handoff_node;
extern vlib_node_registration_t nat44_ed_in2out_node;
extern vlib_node_registration_t nat44_ed_in2out_output_node;
extern vlib_node_registration_t nat44_ed_out2in_node;

extern fib_source_t nat_fib_src_hi;
extern fib_source_t nat_fib_src_low;

/* format functions */
format_function_t format_snat_static_mapping;
format_function_t format_snat_static_map_to_resolve;
format_function_t format_snat_session;
format_function_t format_snat_key;
format_function_t format_static_mapping_key;
format_function_t format_nat_protocol;
format_function_t format_nat_addr_and_port_alloc_alg;
/* unformat functions */
unformat_function_t unformat_nat_protocol;

/** \brief Check if SNAT session is created from static mapping.
    @param s SNAT session
    @return true if SNAT session is created from static mapping otherwise 0
*/
always_inline bool
nat44_ed_is_session_static (snat_session_t *s)
{
  return s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING;
}

/** \brief Check if SNAT session for unknown protocol.
    @param s SNAT session
    @return true if SNAT session for unknown protocol otherwise 0
*/
always_inline bool
snat_is_unk_proto_session (snat_session_t *s)
{
  return s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO;
}

/** \brief Check if NAT session is twice NAT.
    @param s NAT session
    @return true if NAT session is twice NAT
*/
always_inline bool
nat44_ed_is_twice_nat_session (snat_session_t *s)
{
  return s->flags & SNAT_SESSION_FLAG_TWICE_NAT;
}

/** \brief Check if NAT session is load-balancing.
    @param s NAT session
    @return true if NAT session is load-balancing
*/
always_inline bool
nat44_ed_is_lb_session (snat_session_t *s)
{
  return s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING;
}

/** \brief Check if NAT session is forwarding bypass.
    @param s NAT session
    @return true if NAT session is load-balancing
*/
always_inline bool
na44_ed_is_fwd_bypass_session (snat_session_t *s)
{
  return s->flags & SNAT_SESSION_FLAG_FWD_BYPASS;
}

/** \brief Check if NAT session has affinity record.
    @param s NAT session
    @return true if NAT session has affinity record
*/
always_inline bool
nat44_ed_is_affinity_session (snat_session_t *s)
{
  return s->flags & SNAT_SESSION_FLAG_AFFINITY;
}

/** \brief Check if exact pool address should be used.
    @param s SNAT session
    @return true if exact pool address
*/
always_inline bool
nat44_ed_is_exact_address_session (snat_session_t *s)
{
  return s->flags & SNAT_SESSION_FLAG_EXACT_ADDRESS;
}

/** \brief Check if NAT interface is inside.
    @param i NAT interface
    @return true if inside interface
*/
always_inline bool
nat44_ed_is_interface_inside (snat_interface_t *i)
{
  return i->flags & NAT_INTERFACE_FLAG_IS_INSIDE;
}

/** \brief Check if NAT interface is outside.
    @param i NAT interface
    @return true if outside interface
*/
always_inline bool
nat44_ed_is_interface_outside (snat_interface_t *i)
{
  return i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE;
}

/** \brief Check if NAT44 endpoint-dependent TCP session is closed.
    @param s NAT session
    @return true if session is closed
*/
always_inline bool
nat44_is_ses_closed (snat_session_t *s)
{
  return s->state == 0xf;
}

/** \brief Check if client initiating TCP connection (received SYN from client)
    @param t TCP header
    @return true if client initiating TCP connection
*/
always_inline bool
tcp_flags_is_init (u8 f)
{
  return (f & TCP_FLAG_SYN) && !(f & TCP_FLAG_ACK);
}

always_inline bool
is_sm_addr_only (u32 f)
{
  return (f & NAT_SM_FLAG_ADDR_ONLY);
}

always_inline bool
is_sm_out2in_only (u32 f)
{
  return (f & NAT_SM_FLAG_OUT2IN_ONLY);
}

always_inline bool
is_sm_identity_nat (u32 f)
{
  return (f & NAT_SM_FLAG_IDENTITY_NAT);
}

always_inline bool
is_sm_lb (u32 f)
{
  return (f & NAT_SM_FLAG_LB);
}

always_inline bool
is_sm_exact_address (u32 f)
{
  return (f & NAT_SM_FLAG_EXACT_ADDRESS);
}

always_inline bool
is_sm_self_twice_nat (u32 f)
{
  return (f & NAT_SM_FLAG_SELF_TWICE_NAT);
}

always_inline bool
is_sm_twice_nat (u32 f)
{
  return (f & NAT_SM_FLAG_TWICE_NAT);
}

always_inline bool
is_sm_switch_address (u32 f)
{
  return (f & NAT_SM_FLAG_SWITCH_ADDRESS);
}

/* logging */
#define nat_log_err(...) \
  vlib_log(VLIB_LOG_LEVEL_ERR, snat_main.log_class, __VA_ARGS__)
#define nat_log_warn(...) \
  vlib_log(VLIB_LOG_LEVEL_WARNING, snat_main.log_class, __VA_ARGS__)
#define nat_log_notice(...) \
  vlib_log(VLIB_LOG_LEVEL_NOTICE, snat_main.log_class, __VA_ARGS__)
#define nat_log_info(...) \
  vlib_log(VLIB_LOG_LEVEL_INFO, snat_main.log_class, __VA_ARGS__)
#define nat_log_debug(...)\
  vlib_log(VLIB_LOG_LEVEL_DEBUG, snat_main.log_class, __VA_ARGS__)

clib_error_t *nat44_api_hookup (vlib_main_t *vm);

int snat_set_workers (uword *bitmap);

int nat44_plugin_enable (nat44_config_t c);
int nat44_plugin_disable ();

int nat44_ed_add_interface (u32 sw_if_index, u8 is_inside);
int nat44_ed_del_interface (u32 sw_if_index, u8 is_inside);
int nat44_ed_add_output_interface (u32 sw_if_index);
int nat44_ed_del_output_interface (u32 sw_if_index);

int nat44_ed_add_address (ip4_address_t *addr, u32 vrf_id, u8 twice_nat);
int nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat);
int nat44_ed_add_interface_address (u32 sw_if_index, u8 twice_nat);
int nat44_ed_del_interface_address (u32 sw_if_index, u8 twice_nat);

int nat44_ed_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
				 u16 l_port, u16 e_port, nat_protocol_t proto,
				 u32 vrf_id, u32 sw_if_index, u32 flags,
				 ip4_address_t pool_addr, u8 *tag);

int nat44_ed_del_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
				 u16 l_port, u16 e_port, nat_protocol_t proto,
				 u32 vrf_id, u32 sw_if_index, u32 flags);

int nat44_ed_add_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
				    nat_protocol_t proto,
				    nat44_lb_addr_port_t *locals, u32 flags,
				    u8 *tag, u32 affinity);

int nat44_ed_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
				    nat_protocol_t proto, u32 flags);

int nat44_ed_add_del_lb_static_mapping_local (ip4_address_t e_addr, u16 e_port,
					      ip4_address_t l_addr, u16 l_port,
					      nat_protocol_t proto, u32 vrf_id,
					      u8 probability, u8 is_add);

/**
 * @brief Delete NAT44 endpoint-dependent session
 *
 * @param sm     snat global configuration data
 * @param addr   IPv4 address
 * @param port   L4 port number
 * @param proto  L4 protocol
 * @param vrf_id VRF ID
 * @param is_in  1 = inside network address and port pair, 0 = outside
 *
 * @return 0 on success, non-zero value otherwise
 */
int nat44_ed_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
			  ip4_address_t *eh_addr, u16 eh_port, u8 proto,
			  u32 vrf_id, int is_in);

/**
 * @brief Free NAT44 session data (lookup keys, external address port)
 *
 * @param sm           snat global configuration data
 * @param s            NAT session
 * @param thread_index thread index
 * @param is_ha        is HA event
 */
void nat_free_session_data (snat_main_t * sm, snat_session_t * s,
			    u32 thread_index, u8 is_ha);

/**
 * @brief Set NAT44 session limit (session limit, vrf id)
 *
 * @param session_limit Session limit
 * @param vrf_id        VRF id
 * @return 0 on success, non-zero value otherwise
 */
int nat44_set_session_limit (u32 session_limit, u32 vrf_id);

/**
 * @brief Update NAT44 session limit flushing all data (session limit, vrf id)
 *
 * @param session_limit Session limit
 * @param vrf_id        VRF id
 * @return 0 on success, non-zero value otherwise
 */
int nat44_update_session_limit (u32 session_limit, u32 vrf_id);

/**
 * @brief Free outside address and port pair
 *
 * @param addresses    vector of outside addresses
 * @param thread_index thread index
 * @param key          address, port and protocol
 */
void
snat_free_outside_address_and_port (snat_address_t * addresses,
				    u32 thread_index,
				    ip4_address_t * addr,
				    u16 port, nat_protocol_t protocol);

void expire_per_vrf_sessions (u32 fib_index);

/**
 * @brief Match NAT44 static mapping.
 *
 * @param key             address and port to match
 * @param addr            external/local address of the matched mapping
 * @param port            port of the matched mapping
 * @param fib_index       fib index of the matched mapping
 * @param by_external     if 0 match by local address otherwise match by external
 *                        address
 * @param is_addr_only    1 if matched mapping is address only
 * @param twice_nat       matched mapping is twice NAT type
 * @param lb              1 if matched mapping is load-balanced
 * @param ext_host_addr   external host address
 * @param is_identity_nat 1 if indentity mapping
 * @param out             if !=0 set to pointer of the mapping structure
 *
 * @returns 0 if match found otherwise 1.
 */
int snat_static_mapping_match (
  vlib_main_t *vm, snat_main_t *sm, ip4_address_t match_addr, u16 match_port,
  u32 match_fib_index, nat_protocol_t match_protocol,
  ip4_address_t *mapping_addr, u16 *mapping_port, u32 *mapping_fib_index,
  u8 by_external, u8 *is_addr_only, twice_nat_type_t *twice_nat,
  lb_nat_type_t *lb, ip4_address_t *ext_host_addr, u8 *is_identity_nat,
  snat_static_mapping_t **out);

/*
 * Why is this here? Because we don't need to touch this layer to
 * simply reply to an icmp. We need to change id to a unique
 * value to NAT an echo request/reply.
 */

typedef struct
{
  u16 identifier;
  u16 sequence;
} icmp_echo_header_t;

typedef struct
{
  u16 src_port, dst_port;
} tcp_udp_header_t;

u32 get_thread_idx_by_port (u16 e_port);

u8 *format_static_mapping_kvp (u8 *s, va_list *args);

u8 *format_session_kvp (u8 *s, va_list *args);

u32 nat_calc_bihash_buckets (u32 n_elts);

void nat44_addresses_free (snat_address_t **addresses);

void nat44_ed_sessions_clear ();

int nat44_ed_set_frame_queue_nelts (u32 frame_queue_nelts);

typedef enum
{
  NAT_ED_TRNSL_ERR_SUCCESS = 0,
  NAT_ED_TRNSL_ERR_TRANSLATION_FAILED = 1,
  NAT_ED_TRNSL_ERR_FLOW_MISMATCH = 2,
  NAT_ED_TRNSL_ERR_PACKET_TRUNCATED = 3,
  NAT_ED_TRNSL_ERR_INNER_IP_CORRUPT = 4,
  NAT_ED_TRNSL_ERR_INVALID_CSUM = 5,
} nat_translation_error_e;

nat_translation_error_e nat_6t_flow_buf_translate_i2o (
  vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
  nat_6t_flow_t *f, nat_protocol_t proto, int is_output_feature);

nat_translation_error_e nat_6t_flow_buf_translate_o2i (
  vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
  nat_6t_flow_t *f, nat_protocol_t proto, int is_output_feature);

void nat_6t_l3_l4_csum_calc (nat_6t_flow_t *f);

format_function_t format_nat_ed_translation_error;
format_function_t format_nat_6t_flow;
format_function_t format_ed_session_kvp;

#endif /* __included_nat44_ed_h__ */
/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */