summaryrefslogtreecommitdiffstats
path: root/epan/dissectors/packet-osmo_trx.c
blob: b6ac3b416bf45272019b85e17fe11e3d57c98a10 (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
/* packet-osmo_trx.c
 * Dissector for OsmoTRX Protocol (GSM Transceiver control and data).
 *
 * (C) 2018 by Harald Welte <laforge@gnumonks.org>
 * (C) 2019 by Vadim Yanitskiy <axilirator@gmail.com>
 * (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/unit_strings.h>

/* This is a non-standard, ad-hoc protocol to pass baseband GSM bursts between
 * the transceiver (such as osmo-trx, fake_trx.py or grgsm_trx) and the L1
 * program (such as osmo-bts-trx or trxcon). Osmocom inherited this protocol
 * when forking OsmoTRX off the OpenBTS "Transceiver" program. */

void proto_register_osmo_trx(void);
void proto_reg_handoff_osmo_trx(void);

static dissector_handle_t otrxd_handle;
static dissector_handle_t otrxc_handle;

/* Which kind of message it is */
static int proto_otrxd = -1;
static int proto_otrxc = -1;

/* Generated fields */
static int hf_otrxd_burst_dir = -1;
static int hf_otrxc_msg_dir = -1;

/* TRXD PDU version */
static int hf_otrxd_pdu_ver = -1;

/* TRXD common fields */
static int hf_otrxd_chdr_reserved = -1;
static int hf_otrxd_shadow_ind = -1;
static int hf_otrxd_batch_ind = -1;
static int hf_otrxd_trx_num = -1;
static int hf_otrxd_tdma_tn = -1;
static int hf_otrxd_tdma_fn = -1;

/* MTS (Modulation and Training Sequence) fields */
static int hf_otrxd_nope_ind = -1;
static int hf_otrxd_nope_ind_pad = -1;
static int hf_otrxd_mod_2b = -1; /* 2 bit field */
static int hf_otrxd_mod_3b = -1; /* 3 bit field */
static int hf_otrxd_mod_4b = -1; /* 4 bit field */
static int hf_otrxd_tsc_set_x4 = -1;
static int hf_otrxd_tsc_set_x2 = -1;
static int hf_otrxd_tsc = -1;

/* TRXD Rx header fields */
static int hf_otrxd_rssi = -1;
static int hf_otrxd_toa256 = -1;
static int hf_otrxd_ci = -1;

/* TRXD Tx header fields */
static int hf_otrxd_tx_att = -1;
static int hf_otrxd_tx_scpir = -1;
static int hf_otrxd_tx_rfu = -1;

/* Burst soft (255 .. 0) / hard (1 or 0) bits */
static int hf_otrxd_soft_symbols = -1;
static int hf_otrxd_hard_symbols = -1;
static int hf_otrxd_burst_pad = -1;

/* TRXC - Control and Clock protocol */
static int hf_otrxc_type = -1;
static int hf_otrxc_delimiter = -1;
static int hf_otrxc_verb = -1;
static int hf_otrxc_params = -1;
static int hf_otrxc_status = -1;

static gint ett_otrxd = -1;
static gint ett_otrxc = -1;

static gint ett_otrxd_rx_pdu = -1;
static gint ett_otrxd_tx_pdu = -1;

static expert_field ei_otrxd_unknown_pdu_ver = EI_INIT;
static expert_field ei_otrxd_injected_msg = EI_INIT;
static expert_field ei_otrxd_unknown_dir = EI_INIT;
static expert_field ei_otrxd_tail_octets = EI_INIT;

static expert_field ei_otrxc_unknown_msg_type = EI_INIT;
static expert_field ei_otrxc_bad_delimiter = EI_INIT;
static expert_field ei_otrxc_rsp_no_code = EI_INIT;
static expert_field ei_otrxc_injected_msg = EI_INIT;
static expert_field ei_otrxc_unknown_dir = EI_INIT;

/* Custom units */
static const unit_name_string otrx_units_toa256 = { " (1/256 of a symbol)", NULL };

/* TRXD SHADOW.ind value description */
static const true_false_string otrxd_shadow_bool_val = {
	"This is a shadow PDU",
	"This is a primary PDU",
};

/* TRXD BATCH.ind value description */
static const true_false_string otrxd_batch_bool_val = {
	"Another PDU follows",
	"This is the last PDU",
};

/* TRXD NOPE.{ind,req} value description */
static const true_false_string otrxd_nope_bool_val = {
	"Burst is not present",
	"Burst is present",
};

/* TRXD modulation types (2 bit field) */
static const value_string otrxd_mod_2b_vals[] = {
	/* .00xx... */	{ 0x00, "GMSK" },
	/* .11xx... */	{ 0x03, "AQPSK" },
	{ 0, NULL },
};

/* TRXD modulation types (3 bit field) */
static const value_string otrxd_mod_3b_vals[] = {
	/* .010x... */	{ 0x02, "8-PSK" },
	/* .100x... */	{ 0x04, "16QAM" },
	/* .101x... */	{ 0x05, "32QAM" },
	{ 0, NULL },
};

/* TRXD modulation types (4 bit field) */
static const value_string otrxd_mod_4b_vals[] = {
	/* .0110... */	{ 0x06, "GMSK (Access Burst)" },
	/* .0111... */	{ 0x07, "RFU (Reserved for Future Use)" },
	{ 0, NULL },
};

/* TRXD modulation type */
enum otrxd_mod_type {
	OTRXD_MOD_T_GMSK		= 0x00,
	OTRXD_MOD_T_8PSK		= 0x02,
	OTRXD_MOD_T_AQPSK		= 0x03,
	OTRXD_MOD_T_16QAM		= 0x04,
	OTRXD_MOD_T_32QAM		= 0x05,
	OTRXD_MOD_T_GMSK_AB		= 0x06,
	OTRXD_MOD_T_RFU			= 0x07,
};

/* See 3GPP TS 45.002, section 5.2 "Bursts" */
#define GMSK_BURST_LEN			148

/* TRXD modulation / burst length mapping */
static const guint16 otrxd_burst_len[] = {
	[OTRXD_MOD_T_GMSK]		= GMSK_BURST_LEN * 1,
	[OTRXD_MOD_T_GMSK_AB]		= GMSK_BURST_LEN * 1,
	[OTRXD_MOD_T_AQPSK]		= GMSK_BURST_LEN * 2,
	[OTRXD_MOD_T_8PSK]		= GMSK_BURST_LEN * 3,
	[OTRXD_MOD_T_16QAM]		= GMSK_BURST_LEN * 4,
	[OTRXD_MOD_T_32QAM]		= GMSK_BURST_LEN * 5,
	[OTRXD_MOD_T_RFU]		= 0, /* unknown */
};

/* RSSI is encoded without a negative sign, so we need to show it */
static void format_rssi(gchar *buf, const guint32 rssi)
{
	snprintf(buf, ITEM_LABEL_LENGTH, "-%u%s", rssi, unit_name_string_get_value(rssi, &units_dbm));
}

/* TSC (Training Sequence Code) set number in 3GPP TS 45.002 starts
 * from 1, while 'on the wire' it's encoded as X - 1 (starts from 0). */
static void format_tsc_set(gchar *buf, guint32 tsc_set)
{
	snprintf(buf, ITEM_LABEL_LENGTH, "%u", tsc_set + 1);
}

/* Message direction */
enum otrxcd_dir_type {
	OTRXCD_DIR_UNKNOWN = 0,
	OTRXCD_DIR_L12TRX,
	OTRXCD_DIR_TRX2L1,
};

static const value_string otrxcd_dir_vals[] = {
	{ OTRXCD_DIR_UNKNOWN, "Unknown" },
	{ OTRXCD_DIR_L12TRX, "L1 -> TRX" },
	{ OTRXCD_DIR_TRX2L1, "TRX -> L1" },
	{ 0, NULL },
};

/* Determine message direction (L1 to TRX, or TRX to L1?) */
static enum otrxcd_dir_type otrxcd_get_dir(const packet_info *pinfo)
{
	if (pinfo->srcport - pinfo->destport == 100)
		return OTRXCD_DIR_L12TRX;
	else if (pinfo->destport - pinfo->srcport == 100)
		return OTRXCD_DIR_TRX2L1;
	else
		return OTRXCD_DIR_UNKNOWN;
}

/* Guess message direction (L1 to TRX, or TRX to L1?) */
static enum otrxcd_dir_type otrxcd_guess_dir(const packet_info *pinfo)
{
	/* TODO: srcport can be also used for guessing,
	 * TODO: use port numbers from protocol preferences. */
	switch (pinfo->destport) {
	/* OsmoTRXD: Tx burst (L1 -> TRX) */
	case 5702: case 5704: case 6702:
		return OTRXCD_DIR_L12TRX;
	/* OsmoTRXD: Rx burst (TRX -> L1) */
	case 5802: case 5804: case 6802:
		return OTRXCD_DIR_TRX2L1;
	/* OsmoTRXC: Command (L1 -> TRX) */
	case 5701: case 5703: case 6701:
		return OTRXCD_DIR_L12TRX;
	/* OsmoTRXC: Response or Indication (TRX -> L1) */
	case 5801: case 5803: case 6801:
	case 5800: case 6800:
		return OTRXCD_DIR_TRX2L1;
	default:
		return OTRXCD_DIR_UNKNOWN;
	}
}

/* TRXC message types */
enum otrxc_msg_type {
	OTRXC_MSG_TYPE_UNKNOWN = 0,
	OTRXC_MSG_TYPE_COMMAND,
	OTRXC_MSG_TYPE_RESPONSE,
	OTRXC_MSG_TYPE_INDICATION,
};

static const value_string otrxc_msg_type_enc[] = {
	{ OTRXC_MSG_TYPE_COMMAND,	"CMD" },
	{ OTRXC_MSG_TYPE_RESPONSE,	"RSP" },
	{ OTRXC_MSG_TYPE_INDICATION,	"IND" },
	{ 0, NULL },
};

static const value_string otrxc_msg_type_desc[] = {
	{ OTRXC_MSG_TYPE_COMMAND,	"Command" },
	{ OTRXC_MSG_TYPE_RESPONSE,	"Response" },
	{ OTRXC_MSG_TYPE_INDICATION,	"Indication" },
	{ 0, NULL },
};

/* TRXD PDU information */
struct otrxd_pdu_info {
	/* PDU version */
	guint32 ver;
	/* BATCH.ind marker */
	gboolean batch;
	/* SHADOW.ind marker */
	gboolean shadow;
	/* Number of batched PDUs */
	guint32 num_pdus;
	/* TRX (RF channel) number */
	guint32 trx_num;
	/* TDMA frame number */
	guint32 fn;
	/* TDMA timeslot number */
	guint32 tn;
	/* NOPE.{ind,req} marker */
	gboolean nope;
	/* Modulation type and string */
	enum otrxd_mod_type mod;
	const gchar *mod_str;
	/* Training Sequence Code */
	guint32 tsc;
};

/* Dissector for common Rx/Tx TRXDv0/v1 header part */
static void dissect_otrxd_chdr_v0(tvbuff_t *tvb, packet_info *pinfo _U_,
				  proto_item *ti, proto_tree *tree,
				  struct otrxd_pdu_info *pi,
				  int *offset)
{
	proto_tree_add_item(tree, hf_otrxd_chdr_reserved, tvb,
			    *offset, 1, ENC_NA);
	proto_tree_add_item_ret_uint(tree, hf_otrxd_tdma_tn, tvb,
				     *offset, 1, ENC_NA, &pi->tn);
	*offset += 1;

	/* TDMA frame number (4 octets, big endian) */
	proto_tree_add_item_ret_uint(tree, hf_otrxd_tdma_fn, tvb,
				     *offset, 4, ENC_BIG_ENDIAN, &pi->fn);
	*offset += 4;

	proto_item_append_text(ti, "TDMA FN %07u TN %u", pi->fn, pi->tn);
}

/* Dissector for MTS (Modulation and Training Sequence) */
static void dissect_otrxd_mts(tvbuff_t *tvb, proto_tree *tree,
			      struct otrxd_pdu_info *pi,
			      int offset)
{
	/* NOPE indication contains no MTS information.
	 *
	 * | 7 6 5 4 3 2 1 0 | Bit numbers (value range)
	 * | X . . . . . . . | NOPE / IDLE indication
	 * | . X X X X . . . | MTS (Modulation and Training Sequence)
	 * | . . . . . X X X | TSC (Training Sequence Code)
	 */
	proto_tree_add_item_ret_boolean(tree, hf_otrxd_nope_ind, tvb,
					offset, 1, ENC_NA, &pi->nope);
	if (pi->nope) {
		proto_tree_add_item(tree, hf_otrxd_nope_ind_pad, tvb, offset, 1, ENC_NA);
		return;
	}

	/* MTS (Modulation and Training Sequence info).
	 *
	 * | 7 6 5 4 3 2 1 0 | Bit numbers (value range)
	 * | . 0 0 X X . . . | GMSK, 4 TSC sets (0..3)
	 * | . 0 1 0 X . . . | 8-PSK, 2 TSC sets (0..1)
	 * | . 0 1 1 0 . . . | GMSK, Packet Access Burst
	 * | . 0 1 1 1 . . . | RFU (Reserved for Future Use)
	 * | . 1 0 0 X . . . | 16QAM, 2 TSC sets (0..1)
	 * | . 1 0 1 X . . . | 32QAM, 2 TSC sets (0..1)
	 * | . 1 1 X X . . . | AQPSK, 4 TSC sets (0..3)
	 *
	 * NOTE: 3GPP defines 4 TSC sets for both GMSK and AQPSK.
	 */
	guint8 mts = tvb_get_guint8(tvb, offset);
	if ((mts >> 5) == 0x00 || (mts >> 5) == 0x03) { /* 2 bit: GMSK (0) or AQPSK (3) */
		pi->mod = (enum otrxd_mod_type) (mts >> 5);
		pi->mod_str = val_to_str(mts >> 5, otrxd_mod_2b_vals, "Unknown 0x%02x");
		proto_tree_add_item(tree, hf_otrxd_mod_2b, tvb, offset, 1, ENC_NA);
		proto_tree_add_item(tree, hf_otrxd_tsc_set_x4, tvb, offset, 1, ENC_NA);
	} else if ((mts >> 4) != 0x03) { /* 3 bit: 8-PSK, 16QAM, or 32QAM */
		pi->mod = (enum otrxd_mod_type) (mts >> 4);
		pi->mod_str = val_to_str(mts >> 4, otrxd_mod_3b_vals, "Unknown 0x%02x");
		proto_tree_add_item(tree, hf_otrxd_mod_3b, tvb, offset, 1, ENC_NA);
		proto_tree_add_item(tree, hf_otrxd_tsc_set_x2, tvb, offset, 1, ENC_NA);
	} else { /* 4 bit (without TSC set): GMSK (Packet Access Burst) or RFU */
		pi->mod = (enum otrxd_mod_type) (mts >> 3);
		pi->mod_str = val_to_str(mts >> 3, otrxd_mod_4b_vals, "Unknown 0x%02x");
		proto_tree_add_item(tree, hf_otrxd_mod_4b, tvb, offset, 1, ENC_NA);
	}

	proto_tree_add_item_ret_uint(tree, hf_otrxd_tsc, tvb, offset, 1, ENC_NA, &pi->tsc);
}

/* Dissector for Rx TRXD header version 0 */
static int dissect_otrxd_rx_hdr_v0(tvbuff_t *tvb, packet_info *pinfo,
				   proto_item *ti, proto_tree *tree,
				   struct otrxd_pdu_info *pi,
				   int offset)
{
	dissect_otrxd_chdr_v0(tvb, pinfo, ti, tree, pi, &offset);

	proto_tree_add_item(tree, hf_otrxd_rssi, tvb, offset++, 1, ENC_NA);
	proto_tree_add_item(tree, hf_otrxd_toa256, tvb, offset, 2, ENC_NA);
	offset += 2;

	return offset;
}

/* Dissector for Rx TRXD header version 1 */
static int dissect_otrxd_rx_hdr_v1(tvbuff_t *tvb, packet_info *pinfo,
				   proto_item *ti, proto_tree *tree,
				   struct otrxd_pdu_info *pi,
				   int offset)
{
	/* Dissect V0 specific part first */
	offset = dissect_otrxd_rx_hdr_v0(tvb, pinfo, ti, tree, pi, offset);

	/* MTS (Modulation and Training Sequence) */
	dissect_otrxd_mts(tvb, tree, pi, offset++);
	if (!pi->nope)
		proto_item_append_text(ti, ", Modulation %s, TSC %u", pi->mod_str, pi->tsc);
	else
		proto_item_append_text(ti, ", NOPE.ind");

	/* C/I (Carrier to Interference ratio) */
	proto_tree_add_item(tree, hf_otrxd_ci, tvb, offset, 2, ENC_NA);
	offset += 2;

	return offset;
}

/* Dissector for TRXD Rx header version 2 */
static int dissect_otrxd_rx_hdr_v2(tvbuff_t *tvb, packet_info *pinfo _U_,
				   proto_item *ti, proto_tree *tree,
				   struct otrxd_pdu_info *pi,
				   int offset)
{
	proto_tree_add_item(tree, hf_otrxd_chdr_reserved, tvb, offset, 1, ENC_NA);
	proto_tree_add_item_ret_uint(tree, hf_otrxd_tdma_tn, tvb,
				     offset, 1, ENC_NA, &pi->tn);
	offset += 1;

	proto_tree_add_item_ret_boolean(tree, hf_otrxd_batch_ind, tvb,
					offset, 1, ENC_NA, &pi->batch);
	proto_tree_add_item_ret_boolean(tree, hf_otrxd_shadow_ind, tvb,
					offset, 1, ENC_NA, &pi->shadow);
	proto_tree_add_item_ret_uint(tree, hf_otrxd_trx_num, tvb,
				     offset, 1, ENC_NA, &pi->trx_num);
	offset += 1;

	/* MTS (Modulation and Training Sequence) */
	dissect_otrxd_mts(tvb, tree, pi, offset++);

	/* RSSI (Received Signal Strength Indication) */
	proto_tree_add_item(tree, hf_otrxd_rssi, tvb, offset++, 1, ENC_NA);

	/* ToA256 (Timing of Arrival) and C/I (Carrier to Interference ratio) */
	proto_tree_add_item(tree, hf_otrxd_toa256, tvb, offset, 2, ENC_BIG_ENDIAN);
	proto_tree_add_item(tree, hf_otrxd_ci, tvb, offset + 2, 2, ENC_BIG_ENDIAN);
	offset += 4;

	/* TDMA frame number (absent in additional PDUs) */
	if (pi->num_pdus == 0) {
		proto_tree_add_item_ret_uint(tree, hf_otrxd_tdma_fn, tvb,
					     offset, 4, ENC_BIG_ENDIAN, &pi->fn);
		offset += 4;
	}

	proto_item_append_text(ti, "TRXN %02u, TDMA FN %07u TN %u", pi->trx_num, pi->fn, pi->tn);
	if (!pi->nope)
		proto_item_append_text(ti, ", Modulation %s, TSC %u", pi->mod_str, pi->tsc);
	else
		proto_item_append_text(ti, ", NOPE.ind");

	return offset;
}

/* Burst data in Receive direction */
static int dissect_otrxd_rx(tvbuff_t *tvb, packet_info *pinfo,
			    proto_item *pti, proto_tree *ptree,
			    struct otrxd_pdu_info *pi,
			    int offset)
{
	int start, burst_len, padding;
	proto_tree *tree;
	proto_item *ti;

loop:
	/* Add a sub-tree for each PDU (length is set below) */
	tree = proto_tree_add_subtree(ptree, tvb, offset, -1,
				      ett_otrxd_rx_pdu, &ti,
				      "TRXD Rx PDU: ");
	start = offset;

	/* Parse version specific TRXD header part */
	switch (pi->ver) {
	case 0:
		offset = dissect_otrxd_rx_hdr_v0(tvb, pinfo, ti, tree, pi, offset);
		/* The remaining octets is basically soft-bits of the burst */
		burst_len = tvb_reported_length(tvb) - offset;
		/* ... there must be at least 148 soft-bits */
		if (burst_len < GMSK_BURST_LEN)
			burst_len = GMSK_BURST_LEN; /* let it crash! */
		/* ... there can be 2 optional padding octets in the end */
		padding = burst_len % GMSK_BURST_LEN;
		proto_tree_add_item(tree, hf_otrxd_soft_symbols, tvb,
				    offset, burst_len - padding, ENC_NA);
		offset += burst_len - padding;
		if (padding == 0)
			break;
		proto_tree_add_item(tree, hf_otrxd_burst_pad, tvb,
				    offset, padding, ENC_NA);
		offset += padding;
		break;
	case 1:
		offset = dissect_otrxd_rx_hdr_v1(tvb, pinfo, ti, tree, pi, offset);
		if (pi->nope) /* NOPE.ind contains no burst */
			break;
		burst_len = otrxd_burst_len[pi->mod];
		proto_tree_add_item(tree, hf_otrxd_soft_symbols, tvb,
				    offset, burst_len, ENC_NA);
		offset += burst_len;
		break;
	case 2:
		offset = dissect_otrxd_rx_hdr_v2(tvb, pinfo, ti, tree, pi, offset);
		if (pi->nope) /* NOPE.ind contains no burst */
			break;
		burst_len = otrxd_burst_len[pi->mod];
		proto_tree_add_item(tree, hf_otrxd_soft_symbols, tvb,
				    offset, burst_len, ENC_NA);
		offset += burst_len;
		break;
	default:
		expert_add_info_format(pinfo, pti, &ei_otrxd_unknown_pdu_ver,
				       "Unknown TRXD PDU version %u", pi->ver);
		offset = 1; /* Only the PDU version was parsed */
		return offset;
	}

	proto_item_set_len(ti, offset - start);

	/* Number of processed PDUs */
	pi->num_pdus += 1;

	/* There can be additional 'batched' PDUs */
	if (pi->batch)
		goto loop;

	return offset;
}

/* Dissector for TRXDv0/v1 Tx burst */
static void dissect_otrxd_tx_burst_v0(tvbuff_t *tvb, packet_info *pinfo _U_,
				      proto_item *ti, proto_tree *tree,
				      struct otrxd_pdu_info *pi,
				      int *offset)
{
	/* Calculate the burst length */
	const int burst_len = tvb_reported_length(tvb) - *offset;

	/* Attempt to guess modulation by the length */
	switch (burst_len) {
	/* We may also have NOPE.req in the future (to drive fake_trx.py) */
	case 0:
		proto_item_append_text(ti, ", NOPE.req");
		pi->nope = TRUE;
		return;

	/* TODO: introduce an enumerated type, detect other modulation types,
	 * TODO: add a generated field for "osmo_trxd.mod" */
	case GMSK_BURST_LEN:
		proto_item_append_text(ti, ", Modulation GMSK");
		pi->mod_str = "GMSK";
		break;
	case 3 * GMSK_BURST_LEN:
		proto_item_append_text(ti, ", Modulation 8-PSK");
		pi->mod_str = "8-PSK";
		break;
	}

	/* Hard-bits (1 or 0) */
	proto_tree_add_item(tree, hf_otrxd_hard_symbols, tvb,
			    *offset, burst_len, ENC_NA);
	*offset += burst_len;
}

/* Dissector for TRXD Tx header version 2 */
static void dissect_otrxd_tx_hdr_v2(tvbuff_t *tvb, packet_info *pinfo _U_,
				    proto_item *ti, proto_tree *tree,
				    struct otrxd_pdu_info *pi,
				    int *offset)
{
	proto_tree_add_item(tree, hf_otrxd_chdr_reserved, tvb, *offset, 1, ENC_NA);
	proto_tree_add_item_ret_uint(tree, hf_otrxd_tdma_tn, tvb,
				     *offset, 1, ENC_NA, &pi->tn);
	*offset += 1;

	proto_tree_add_item_ret_boolean(tree, hf_otrxd_batch_ind, tvb,
					*offset, 1, ENC_NA, &pi->batch);
	proto_tree_add_item_ret_uint(tree, hf_otrxd_trx_num, tvb,
				     *offset, 1, ENC_NA, &pi->trx_num);
	*offset += 1;

	/* MTS (Modulation and Training Sequence) */
	dissect_otrxd_mts(tvb, tree, pi, *offset);
	*offset += 1;

	/* Tx power attenuation */
	proto_tree_add_item(tree, hf_otrxd_tx_att, tvb, *offset, 1, ENC_NA);
	*offset += 1;

	/* SCPIR (Subchannel Power Imbalance Ratio) */
	proto_tree_add_item(tree, hf_otrxd_tx_scpir, tvb, *offset, 1, ENC_NA);
	*offset += 1;

	/* RFU (currently just to make the header dword-alignment) */
	proto_tree_add_item(tree, hf_otrxd_tx_rfu, tvb, *offset, 3, ENC_NA);
	*offset += 3;

	/* TDMA frame number (absent in additional PDUs) */
	if (pi->num_pdus == 0) {
		proto_tree_add_item_ret_uint(tree, hf_otrxd_tdma_fn, tvb,
					     *offset, 4, ENC_BIG_ENDIAN, &pi->fn);
		*offset += 4;
	}

	proto_item_append_text(ti, "TRXN %02u, TDMA FN %07u TN %u", pi->trx_num, pi->fn, pi->tn);
	if (!pi->nope)
		proto_item_append_text(ti, ", Modulation %s, TSC %u", pi->mod_str, pi->tsc);
	else
		proto_item_append_text(ti, ", NOPE.req");
}

/* Burst data in Transmit direction */
static int dissect_otrxd_tx(tvbuff_t *tvb, packet_info *pinfo,
			    proto_item *pti, proto_tree *ptree,
			    struct otrxd_pdu_info *pi,
			    int offset)
{
	proto_tree *tree;
	proto_item *ti;
	int burst_len;
	int start;

loop:
	/* Add a sub-tree for each PDU (length is set below) */
	tree = proto_tree_add_subtree(ptree, tvb, offset, -1,
				      ett_otrxd_tx_pdu, &ti,
				      "TRXD Tx PDU: ");
	start = offset;

	switch (pi->ver) {
	/* Both versions feature the same PDU format */
	case 0:
	case 1:
		dissect_otrxd_chdr_v0(tvb, pinfo, ti, tree, pi, &offset);
		proto_tree_add_item(tree, hf_otrxd_tx_att, tvb, offset++, 1, ENC_NA);
		dissect_otrxd_tx_burst_v0(tvb, pinfo, ti, tree, pi, &offset);
		break;
	case 2:
		dissect_otrxd_tx_hdr_v2(tvb, pinfo, ti, tree, pi, &offset);
		if (pi->nope) /* NOPE.ind contains no burst */
			break;
		burst_len = otrxd_burst_len[pi->mod];
		proto_tree_add_item(tree, hf_otrxd_hard_symbols, tvb,
				    offset, burst_len, ENC_NA);
		offset += burst_len;
		break;
	default:
		expert_add_info_format(pinfo, pti, &ei_otrxd_unknown_pdu_ver,
				       "Unknown TRXD PDU version %u", pi->ver);
		offset = 1; /* Only the PDU version was parsed */
		return offset;
	}

	proto_item_set_len(ti, offset - start);

	/* Number of processed PDUs */
	pi->num_pdus += 1;

	/* There can be additional 'batched' PDUs */
	if (pi->batch)
		goto loop;

	return offset;
}

/* Common dissector for bursts in both directions */
static int dissect_otrxd(tvbuff_t *tvb, packet_info *pinfo,
			 proto_tree *tree, void* data _U_)
{
	struct otrxd_pdu_info pi = { 0 };
	proto_tree *otrxd_tree;
	proto_item *ti, *gi;
	int offset = 0;

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "OsmoTRXD");
	col_clear(pinfo->cinfo, COL_INFO);

	ti = proto_tree_add_item(tree, proto_otrxd, tvb, 0, -1, ENC_NA);
	otrxd_tree = proto_item_add_subtree(ti, ett_otrxd);

	/* Determine the burst direction */
	int burst_dir = otrxcd_get_dir(pinfo);

	/* A burst might be injected by some other program using
	 * a random source port, so let's try to guess by destport. */
	if (burst_dir == OTRXCD_DIR_UNKNOWN) {
		expert_add_info(pinfo, ti, &ei_otrxd_injected_msg);
		burst_dir = otrxcd_guess_dir(pinfo);
	}

	if (burst_dir == OTRXCD_DIR_L12TRX)
		col_append_str(pinfo->cinfo, COL_INFO, "Tx burst (L1 -> TRX): ");
	else if (burst_dir == OTRXCD_DIR_TRX2L1)
		col_append_str(pinfo->cinfo, COL_INFO, "Rx burst (TRX -> L1): ");
	else
		col_append_str(pinfo->cinfo, COL_INFO, "Tx/Rx burst (Unknown): ");

	/* Add a generated field, so we can filter bursts by direction */
	gi = proto_tree_add_uint(otrxd_tree, hf_otrxd_burst_dir,
				 tvb, 0, 0, burst_dir);
	proto_item_set_generated(gi);

	/* Parse common TRXD PDU version */
	proto_tree_add_item_ret_uint(otrxd_tree, hf_otrxd_pdu_ver, tvb,
				     offset, 1, ENC_NA, &pi.ver);
	proto_item_append_text(ti, " Version %u", pi.ver);

	if (burst_dir == OTRXCD_DIR_L12TRX)
		offset = dissect_otrxd_tx(tvb, pinfo, ti, otrxd_tree, &pi, offset);
	else if (burst_dir == OTRXCD_DIR_TRX2L1)
		offset = dissect_otrxd_rx(tvb, pinfo, ti, otrxd_tree, &pi, offset);
	else {
		expert_add_info(pinfo, ti, &ei_otrxd_unknown_dir);
		offset = 1; /* Only the PDU version was parsed */
	}

	/* Summary for all parsed PDUs */
	if (pi.num_pdus == 1) {
		col_append_fstr(pinfo->cinfo, COL_INFO, "TDMA FN %07u TN %u", pi.fn, pi.tn);
		if (pi.mod_str != NULL)
			col_append_fstr(pinfo->cinfo, COL_INFO, ", Modulation %s", pi.mod_str);
		else if (pi.nope && burst_dir == OTRXCD_DIR_TRX2L1)
			col_append_str(pinfo->cinfo, COL_INFO, ", NOPE.ind");
		else if (pi.nope && burst_dir == OTRXCD_DIR_L12TRX)
			col_append_str(pinfo->cinfo, COL_INFO, ", NOPE.req");
	} else if (pi.num_pdus > 1) {
		col_append_fstr(pinfo->cinfo, COL_INFO, "TDMA FN %07u", pi.fn);
		col_append_fstr(pinfo->cinfo, COL_INFO, ", %u batched PDUs ", pi.num_pdus);
	}

	proto_item_set_len(ti, offset);

	/* Let it warn us if there are unhandled tail octets */
	if ((guint) offset < tvb_reported_length(tvb))
		expert_add_info(pinfo, ti, &ei_otrxd_tail_octets);

	return offset;
}

/* Dissector for Control commands and responses, and Clock indications */
static int dissect_otrxc(tvbuff_t *tvb, packet_info *pinfo,
			 proto_tree *tree, void *data _U_)
{
	int offset = 0, msg_len, end_verb, end_status;
	const guint8 *msg_str, *msg_type_str;
	proto_item *ti, *gi, *delim_item;
	proto_tree *otrxc_tree;
	guint32 delimiter;

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "OsmoTRXC");
	col_clear(pinfo->cinfo, COL_INFO);

	msg_len = tvb_reported_length(tvb);
	msg_str = tvb_get_string_enc(pinfo->pool, tvb, 0, msg_len, ENC_ASCII);
	col_add_str(pinfo->cinfo, COL_INFO, msg_str);

	ti = proto_tree_add_item(tree, proto_otrxc, tvb, 0, msg_len, ENC_ASCII);
	otrxc_tree = proto_item_add_subtree(ti, ett_otrxc);

	/* Determine the message direction */
	int msg_dir = otrxcd_get_dir(pinfo);

	/* A message might be injected by some other program using
	 * a random source port, so let's try to guess by destport. */
	if (msg_dir == OTRXCD_DIR_UNKNOWN) {
		expert_add_info(pinfo, ti, &ei_otrxc_injected_msg);
		if ((msg_dir = otrxcd_guess_dir(pinfo)) == OTRXCD_DIR_UNKNOWN)
			expert_add_info(pinfo, ti, &ei_otrxc_unknown_dir);
	}

	/* Add a generated field, so we can filter bursts by direction */
	gi = proto_tree_add_uint(otrxc_tree, hf_otrxc_msg_dir,
				 tvb, 0, 0, msg_dir);
	proto_item_set_generated(gi);

	/* First 3 bytes define a type of the message ("IND", "CMD", "RSP") */
	proto_tree_add_item_ret_string(otrxc_tree, hf_otrxc_type, tvb, offset, 3,
				       ENC_NA | ENC_ASCII, pinfo->pool,
				       &msg_type_str);
	offset += 3;

	/* Determine the message type */
	enum otrxc_msg_type msg_type = str_to_val((const gchar *) msg_type_str,
						  otrxc_msg_type_enc,
						  OTRXC_MSG_TYPE_UNKNOWN);
	proto_item_append_text(ti, ", %s", val_to_str_const(msg_type, otrxc_msg_type_desc,
							    "Unknown message type"));
	if (msg_type == OTRXC_MSG_TYPE_UNKNOWN) {
		expert_add_info(pinfo, ti, &ei_otrxc_unknown_msg_type);
		return offset;
	}

	/* The message type is separated by a delimiter */
	delim_item = proto_tree_add_item_ret_uint(otrxc_tree, hf_otrxc_delimiter,
						  tvb, offset, 1, ENC_NA, &delimiter);
	proto_item_set_hidden(delim_item);
	offset += 1;

	/* Delimiter should be a space symbol */
	if (delimiter != 0x20)
		expert_add_info(pinfo, delim_item, &ei_otrxc_bad_delimiter);

	/* The message type is followed by a verb, e.g. "IND CLOCK", "CMD POWEROFF" */
	end_verb = tvb_find_guint8(tvb, offset, -1, (char) delimiter);
	if (end_verb < 0) {
		/* Just a command without parameters, e.g. "CMD POWERON" */
		proto_tree_add_item(otrxc_tree, hf_otrxc_verb, tvb,
				    offset, -1, ENC_ASCII | ENC_NA);
		if (msg_type == OTRXC_MSG_TYPE_RESPONSE)
			expert_add_info(pinfo, ti, &ei_otrxc_rsp_no_code);
		return tvb_captured_length(tvb);
	} else {
		proto_tree_add_item(otrxc_tree, hf_otrxc_verb, tvb,
				    offset, end_verb - offset,
				    ENC_ASCII | ENC_NA);
		offset = end_verb;
	}

	/* Another delimiter between the verb and status code / parameters */
	delim_item = proto_tree_add_item_ret_uint(otrxc_tree, hf_otrxc_delimiter,
						  tvb, offset, 1, ENC_NA, &delimiter);
	proto_item_set_hidden(delim_item);
	offset += 1;

	if (msg_type == OTRXC_MSG_TYPE_RESPONSE) {
		end_status = tvb_find_guint8(tvb, offset, -1, (char) delimiter);
		if (end_status > 0) {
			proto_tree_add_item(otrxc_tree, hf_otrxc_status,
					    tvb, offset, end_status - offset, ENC_ASCII | ENC_NA);
			offset = end_status;

			/* Another delimiter between the status code and parameters */
			delim_item = proto_tree_add_item_ret_uint(otrxc_tree, hf_otrxc_delimiter,
								  tvb, offset, 1, ENC_NA, &delimiter);
			proto_item_set_hidden(delim_item);
			offset += 1;
		} else if (offset < msg_len) {
			/* Response without parameters, e.g. "RSP POWEROFF 0" */
			proto_tree_add_item(otrxc_tree, hf_otrxc_status,
					    tvb, offset, msg_len - offset, ENC_ASCII | ENC_NA);
			return tvb_captured_length(tvb);
		} else {
			expert_add_info(pinfo, ti, &ei_otrxc_rsp_no_code);
			return offset;
		}
	}

	if (offset < msg_len) {
		proto_tree_add_item(otrxc_tree, hf_otrxc_params,
				    tvb, offset, -1, ENC_ASCII | ENC_NA);
	}

	return tvb_captured_length(tvb);
}

void proto_register_osmo_trx(void)
{
	static hf_register_info hf_otrxd[] = {
		/* Common generated field: burst direction */
		{ &hf_otrxd_burst_dir, { "Burst Direction", "osmo_trx.direction",
		  FT_UINT8, BASE_DEC, VALS(otrxcd_dir_vals), 0, NULL, HFILL } },

		/* Rx/Tx header fields */
		{ &hf_otrxd_pdu_ver, { "PDU Version", "osmo_trxd.pdu_ver",
		  FT_UINT8, BASE_DEC, NULL, 0xf0, NULL, HFILL } },
		{ &hf_otrxd_chdr_reserved, { "Reserved", "osmo_trxd.chdr_reserved",
		  FT_UINT8, BASE_DEC, NULL, 0x08, NULL, HFILL } },
		{ &hf_otrxd_tdma_tn, { "TDMA Timeslot Number", "osmo_trxd.tdma.tn",
		  FT_UINT8, BASE_DEC, NULL, 0x07, NULL, HFILL } },
		{ &hf_otrxd_tdma_fn, { "TDMA Frame Number", "osmo_trxd.tdma.fn",
		  FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL } },
		{ &hf_otrxd_batch_ind, { "BATCH Indication", "osmo_trxd.batch_ind",
		  FT_BOOLEAN, 8, TFS(&otrxd_batch_bool_val), 0x80, NULL, HFILL } },
		{ &hf_otrxd_shadow_ind, { "PDU class", "osmo_trxd.shadow_ind",
		  FT_BOOLEAN, 8, TFS(&otrxd_shadow_bool_val), 0x40, NULL, HFILL } },
		{ &hf_otrxd_trx_num, { "TRX (RF Channel) Number", "osmo_trxd.trx_num",
		  FT_UINT8, BASE_DEC, NULL, 0x3f, NULL, HFILL } },

		/* Rx header fields */
		{ &hf_otrxd_rssi, { "RSSI", "osmo_trxd.meas.rssi",
		  FT_UINT8, BASE_CUSTOM, CF_FUNC(format_rssi), 0, NULL, HFILL } },
		{ &hf_otrxd_toa256, { "Timing of Arrival", "osmo_trxd.meas.toa256",
		  FT_INT16, BASE_DEC | BASE_UNIT_STRING, &otrx_units_toa256, 0, NULL, HFILL } },

		/* MTS (Modulation and Training Sequence) fields */
		{ &hf_otrxd_nope_ind, { "NOPE Indication", "osmo_trxd.nope_ind",
		  FT_BOOLEAN, 8, TFS(&otrxd_nope_bool_val), 0x80, NULL, HFILL } },
		{ &hf_otrxd_nope_ind_pad, { "NOPE Padding", "osmo_trxd.nope_ind_pad",
		  FT_UINT8, BASE_DEC, NULL, 0x7f, NULL, HFILL } },
		{ &hf_otrxd_mod_2b, { "Modulation", "osmo_trxd.mod",
		  FT_UINT8, BASE_DEC, VALS(otrxd_mod_2b_vals), 0x60, NULL, HFILL } },
		{ &hf_otrxd_mod_3b, { "Modulation", "osmo_trxd.mod",
		  FT_UINT8, BASE_DEC, VALS(otrxd_mod_3b_vals), 0x70, NULL, HFILL } },
		{ &hf_otrxd_mod_4b, { "Modulation", "osmo_trxd.mod",
		  FT_UINT8, BASE_DEC, VALS(otrxd_mod_4b_vals), 0x78, NULL, HFILL } },
		{ &hf_otrxd_tsc_set_x2, { "TSC Set", "osmo_trxd.tsc_set",
		  FT_UINT8, BASE_CUSTOM, CF_FUNC(format_tsc_set), 0x08, NULL, HFILL } },
		{ &hf_otrxd_tsc_set_x4, { "TSC Set", "osmo_trxd.tsc_set",
		  FT_UINT8, BASE_CUSTOM, CF_FUNC(format_tsc_set), 0x18, NULL, HFILL } },
		{ &hf_otrxd_tsc, { "TSC (Training Sequence Code)", "osmo_trxd.tsc",
		  FT_UINT8, BASE_DEC, NULL, 0x07, NULL, HFILL } },
		{ &hf_otrxd_ci, { "C/I (Carrier-to-Interference ratio)", "osmo_trxd.meas.ci",
		  FT_INT16, BASE_DEC | BASE_UNIT_STRING, &units_centibels, 0, NULL, HFILL } },

		/* Tx header fields */
		{ &hf_otrxd_tx_att, { "Tx Attenuation", "osmo_trxd.tx_att",
		  FT_UINT8, BASE_DEC | BASE_UNIT_STRING, &units_decibels, 0, NULL, HFILL } },
		{ &hf_otrxd_tx_scpir, { "SCPIR Value", "osmo_trxd.scpir_val",
		  FT_INT8, BASE_DEC | BASE_UNIT_STRING, &units_decibels, 0, NULL, HFILL } },
		{ &hf_otrxd_tx_rfu, { "Spare padding", "osmo_trxd.spare",
		  FT_BYTES, SEP_SPACE, NULL, 0, NULL, HFILL } },

		/* Burst soft (255 .. 0) / hard (1 or 0) bits */
		{ &hf_otrxd_soft_symbols, { "Soft-bits", "osmo_trxd.burst.sbits",
		  FT_BYTES, SEP_SPACE, NULL, 0, NULL, HFILL } },
		{ &hf_otrxd_hard_symbols, { "Hard-bits", "osmo_trxd.burst.hbits",
		  FT_BYTES, SEP_SPACE, NULL, 0, NULL, HFILL } },
		{ &hf_otrxd_burst_pad, { "Legacy padding", "osmo_trxd.burst.pad",
		  FT_BYTES, SEP_SPACE, NULL, 0, NULL, HFILL } },
	};

	static hf_register_info hf_otrxc[] = {
		/* Common generated field: message direction */
		{ &hf_otrxc_msg_dir, { "Message Direction", "osmo_trx.direction",
		  FT_UINT8, BASE_DEC, VALS(otrxcd_dir_vals), 0, NULL, HFILL } },

		{ &hf_otrxc_type, { "Type", "osmo_trxc.type",
		  FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL } },
		{ &hf_otrxc_delimiter, { "Delimiter", "osmo_trxc.delim",
		  FT_CHAR, BASE_HEX, NULL, 0, NULL, HFILL } },
		{ &hf_otrxc_verb, { "Verb", "osmo_trxc.verb",
		  FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL } },
		{ &hf_otrxc_status, { "Status", "osmo_trxc.status",
		  FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL } },
		{ &hf_otrxc_params, { "Parameters", "osmo_trxc.params",
		  FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL } },
	};

	static gint *ett[] = {
		&ett_otrxd,
		&ett_otrxd_rx_pdu,
		&ett_otrxd_tx_pdu,
		&ett_otrxc,
	};

	proto_otrxd = proto_register_protocol("OsmoTRX Data Protocol",
					      "OsmoTRXD", "osmo_trxd");
	proto_otrxc = proto_register_protocol("OsmoTRX Control / Clock Protocol",
					      "OsmoTRXC", "osmo_trxc");

	proto_register_field_array(proto_otrxd, hf_otrxd, array_length(hf_otrxd));
	proto_register_field_array(proto_otrxc, hf_otrxc, array_length(hf_otrxc));
	proto_register_subtree_array(ett, array_length(ett));

	static ei_register_info ei_otrxd[] = {
		{ &ei_otrxd_injected_msg, { "osmo_trx.ei.injected_msg",
		  PI_COMMENTS_GROUP, PI_COMMENT, "Injected message", EXPFILL } },
		{ &ei_otrxd_unknown_dir, { "osmo_trx.ei.unknown_dir",
		  PI_UNDECODED, PI_ERROR, "Unknown direction", EXPFILL } },
		{ &ei_otrxd_unknown_pdu_ver, { "osmo_trxd.ei.unknown_pdu_ver",
		  PI_PROTOCOL, PI_ERROR, "Unknown PDU version", EXPFILL } },
		{ &ei_otrxd_tail_octets, { "osmo_trxd.ei.tail_octets",
		  PI_UNDECODED, PI_WARN, "Unhandled tail octets", EXPFILL } },
	};

	static ei_register_info ei_otrxc[] = {
		{ &ei_otrxc_injected_msg, { "osmo_trx.ei.injected_msg",
		  PI_COMMENTS_GROUP, PI_COMMENT, "Injected message", EXPFILL } },
		{ &ei_otrxc_unknown_dir, { "osmo_trx.ei.unknown_dir",
		  PI_ASSUMPTION, PI_WARN, "Unknown direction", EXPFILL } },
		{ &ei_otrxc_bad_delimiter, { "osmo_trxc.ei.bad_delimiter",
		  PI_PROTOCOL, PI_WARN, "Invalid delimiter", EXPFILL } },
		{ &ei_otrxc_rsp_no_code, { "osmo_trxc.ei.rsp_no_code",
		  PI_PROTOCOL, PI_ERROR, "Response without status code", EXPFILL } },
		{ &ei_otrxc_unknown_msg_type, { "osmo_trxc.ei.unknown_msg_type",
		  PI_PROTOCOL, PI_ERROR, "Unknown message type", EXPFILL } },
	};

	/* Expert info for OsmoTRXD protocol */
	expert_module_t *expert_otrxd = expert_register_protocol(proto_otrxd);
	expert_register_field_array(expert_otrxd, ei_otrxd, array_length(ei_otrxd));

	/* Expert info for OsmoTRXC protocol */
	expert_module_t *expert_otrxc = expert_register_protocol(proto_otrxc);
	expert_register_field_array(expert_otrxc, ei_otrxc, array_length(ei_otrxc));

	/* Register the dissectors */
	otrxd_handle = register_dissector("osmo_trxd", dissect_otrxd, proto_otrxd);
	otrxc_handle = register_dissector("osmo_trxc", dissect_otrxc, proto_otrxc);
}

void proto_reg_handoff_osmo_trx(void)
{
#if 0
/* The TRX-side control interface for C(N) is on port P = B + 2N + 1;
 * the corresponding core-side interface for every socket is at P + 100.
 * Give a base port B (5700), the master clock interface is at port P = B. */
#define OTRXC_UDP_PORTS \
	"5701,5703,5800,5801,5803,"  /* The BTS side (osmo-trx, osmo-bts-trx) */ \
	"6701,6703,6800,6801,6803"   /* The MS side (trxcon, fake_trx, grgsm_trx) */

/* The data interface is on an odd numbered port P = B + 2N + 2. */
#define OTRXD_UDP_PORTS \
	"5702,5802,"  /* The BTS side, TRX0 (osmo-trx, osmo-bts-trx) */ \
	"5704,5804,"  /* The BTS side, TRX1 (osmo-trx, osmo-bts-trx) */ \
	"6702,6802"   /* The MS side (trxcon, fake_trx, grgsm_trx) */

	dissector_add_uint_range_with_preference("udp.port", OTRXD_UDP_PORTS, otrxd_handle);
	dissector_add_uint_range_with_preference("udp.port", OTRXC_UDP_PORTS, otrxc_handle);
#endif

	dissector_add_for_decode_as("udp.port", otrxd_handle);
	dissector_add_for_decode_as("udp.port", otrxc_handle);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */