summaryrefslogtreecommitdiffstats
path: root/tests/lapd/lapd_test.c
blob: e3223143bb2fd2c93073c682190956954e6ad171 (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
/*
 * (C) 2011 by Holger Hans Peter Freyther
 * (C) 2011 by On-Waves
 * (C) 2014 by Daniel Willmann <dwillmann@sysmocom.de>
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#include <osmocom/core/application.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/utils.h>
#include <osmocom/gsm/lapdm.h>
#include <osmocom/gsm/rsl.h>

#include <errno.h>

#include <string.h>

#define CHECK_RC(rc)	\
	if (rc != 0) {	\
		printf("Operation failed rc=%d on %s:%d\n", rc, __FILE__, __LINE__); \
		abort(); \
	}

static struct log_info info = {};
static int dummy_l1_header_len = 0;

struct lapdm_polling_state {
	struct lapdm_channel *bts;
	int bts_read;

	struct lapdm_channel *ms;
	int ms_read;
};

static struct msgb *msgb_from_array(const uint8_t *data, int len)
{
	struct msgb *msg = msgb_alloc_headroom(4096, 128, "data");
	msg->l3h = msgb_put(msg, len);
	if (data && len)
		memcpy(msg->l3h, data, len);
	return msg;
}

/*
 * Test data is below...
 */
static const uint8_t cm[] = {
	0x05, 0x24, 0x31, 0x03, 0x50, 0x18, 0x93, 0x08,
	0x29, 0x47, 0x80, 0x00, 0x00, 0x00, 0x00, 0x80,
};

static const uint8_t ua[] = {
	0x01, 0x73, 0x41, 0x05, 0x24, 0x31, 0x03, 0x50,
	0x18, 0x93, 0x08, 0x29, 0x47, 0x80, 0x00, 0x00,
	0x00, 0x00, 0x80, 0x2b, 0x2b, 0x2b, 0x2b
};

static const uint8_t mm[] = {
	0x00, 0x0c, 0x00, 0x03, 0x01, 0x01, 0x20, 0x02,
	0x00, 0x0b, 0x00, 0x03, 0x05, 0x04, 0x0d
};

static const uint8_t dummy1[] = {
	0xab, 0x03, 0x30, 0x60, 0x06,
};

static const uint8_t rel_req[] = {
	0x02, 0x07, 0x01, 0x0a, 0x02, 0x40, 0x14, 0x01
};

static const uint8_t est_req_sdcch_sapi3[] = {
	0x02, 0x04, 0x01, 0x20, 0x02, 0x03
};

static const uint8_t est_req_sacch_sapi3[] = {
	0x02, 0x04, 0x01, 0x0b, 0x02, 0x43
};

static struct msgb *create_cm_serv_req(void)
{
	struct msgb *msg;

	msg = msgb_from_array(cm, sizeof(cm));
	rsl_rll_push_l3(msg, RSL_MT_EST_REQ, 0, 0, 1);
	msgb_push(msg, dummy_l1_header_len);
	return msg;
}

static struct msgb *create_mm_id_req(void)
{
	struct msgb *msg;

	msg = msgb_from_array(mm, sizeof(mm));
	msg->l2h = msg->data + 3;
	OSMO_ASSERT(msgb_l2len(msg) == 12);
	msg->l3h = msg->l2h + 6;
	OSMO_ASSERT(msgb_l3len(msg) == 6);
	msgb_push(msg, dummy_l1_header_len);

	return msg;
}

static struct msgb *create_empty_msg(void)
{
	struct msgb *msg;

	msg = msgb_from_array(NULL, 0);
	OSMO_ASSERT(msgb_l3len(msg) == 0);
	rsl_rll_push_l3(msg, RSL_MT_DATA_REQ, 0, 0, 1);
	msgb_push(msg, dummy_l1_header_len);
	return msg;
}

static struct msgb *create_dummy_data_req(void)
{
	struct msgb *msg;

	msg = msgb_from_array(dummy1, sizeof(dummy1));
	rsl_rll_push_l3(msg, RSL_MT_DATA_REQ, 0, 0, 1);
	msgb_push(msg, dummy_l1_header_len);
	return msg;
}

static struct msgb *create_rel_req(void)
{
	struct msgb *msg;

	msg = msgb_from_array(rel_req, sizeof(rel_req));
	msg->l2h = msg->data;
	msgb_push(msg, dummy_l1_header_len);
	msg->l3h = msg->l2h + sizeof(struct abis_rsl_rll_hdr);
	return msg;
}

static struct msgb *create_est_req(const uint8_t *est_req, size_t est_req_size)
{
	struct msgb *msg;

	msg = msgb_from_array(est_req, est_req_size);
	msg->l2h = msg->data;
	msgb_push(msg, dummy_l1_header_len);
	msg->l3h = msg->l2h + sizeof(struct abis_rsl_rll_hdr);
	return msg;
}

static int send(struct msgb *in_msg, struct lapdm_channel *chan)
{
	struct osmo_phsap_prim pp;
	struct msgb *msg;
	int rc;

	msg = msgb_alloc_headroom(128, 64, "PH-DATA.ind");
	osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_DATA,
			PRIM_OP_INDICATION, msg);
	/* copy over actual MAC block */
	msg->l2h = msgb_put(msg, msgb_l2len(in_msg));
	memcpy(msg->l2h, in_msg->l2h, msgb_l2len(in_msg));

	/* LAPDm requires those... */
	pp.u.data.chan_nr = 0;
	pp.u.data.link_id = 0;
        /* feed into the LAPDm code of libosmogsm */
        rc = lapdm_phsap_up(&pp.oph, &chan->lapdm_dcch);
	OSMO_ASSERT(rc == 0 || rc == -EBUSY);
	return 0;
}

/* Receive from L1 */
static int send_buf(const uint8_t *buf, size_t len, struct lapdm_channel *chan)
{
	struct osmo_phsap_prim pp;
	struct msgb *msg;
	int rc;

	msg = msgb_from_array(buf, len);
	msg->l2h = msg->l3h;
	msg->l3h = NULL;
	osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_DATA,
			PRIM_OP_INDICATION, msg);

	/* LAPDm requires those... */
	pp.u.data.chan_nr = 0;
	pp.u.data.link_id = 0;
        /* feed into the LAPDm code of libosmogsm */
        rc = lapdm_phsap_up(&pp.oph, &chan->lapdm_dcch);
	OSMO_ASSERT(rc == 0 || rc == -EBUSY);
	return 0;
}

/* Receive from L3 */
static int enqueue_buf(const uint8_t *buf, size_t len, int sapi, struct lapdm_channel *chan)
{
	struct osmo_dlsap_prim dp;
	struct msgb *msg;
	int rc;
	struct lapdm_datalink *dl;

	dl = lapdm_datalink_for_sapi(&chan->lapdm_dcch, sapi);
	OSMO_ASSERT(dl);

	msg = msgb_from_array(buf, len);
	osmo_prim_init(&dp.oph, 0, PRIM_DL_DATA, PRIM_OP_REQUEST, msg);

	rc = lapd_recv_dlsap(&dp, &dl->dl.lctx);
	OSMO_ASSERT(rc == 0 || rc == -EBUSY);
	return 0;
}

static int send_sabm(struct lapdm_channel *chan, int sapi, const uint8_t *data, size_t len)
{
	struct osmo_phsap_prim pp;
	struct msgb *msg;
	int rc;

	OSMO_ASSERT(sapi == 0 || sapi == 3);

	msg = msgb_alloc_headroom(128, 64, "PH-DATA.ind");
	osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_DATA,
			PRIM_OP_INDICATION, msg);
	/* copy over actual MAC block */
	msg->l2h = msgb_put(msg, 3 + len);
	msg->l2h[0] = 0x01 | (sapi << 2);
	msg->l2h[1] = 0x3f;
	msg->l2h[2] = 0x01 | (len << 2);

	if (len > 0)
		memcpy(msg->l2h + 3, data, len);

	/* LAPDm requires those... */
	pp.u.data.chan_nr = 0;
	pp.u.data.link_id = 0;
        /* feed into the LAPDm code of libosmogsm */
        rc = lapdm_phsap_up(&pp.oph, &chan->lapdm_dcch);
	OSMO_ASSERT(rc == 0 || rc == -EBUSY);
	return 0;
}

/*
 * I get called from the LAPDm code when something was sent my way...
 */
static int bts_to_ms_tx_cb(struct msgb *in_msg, struct lapdm_entity *le, void *_ctx)
{
	struct lapdm_polling_state *state = _ctx;


	printf("%s: MS->BTS(us) message %d\n", __func__, msgb_length(in_msg));


	if (state->bts_read == 0) {
		printf("BTS: Verifying CM request.\n");
		OSMO_ASSERT(msgb_l3len(in_msg) == ARRAY_SIZE(cm));
		OSMO_ASSERT(memcmp(in_msg->l3h, cm,
			ARRAY_SIZE(cm)) == 0);
	} else if (state->bts_read == 1) {
		printf("BTS: Verifying dummy message.\n");
		OSMO_ASSERT(msgb_l3len(in_msg) == ARRAY_SIZE(dummy1));
		OSMO_ASSERT(memcmp(in_msg->l3h, dummy1,
			ARRAY_SIZE(dummy1)) == 0);
	} else {
		printf("BTS: Do not know to verify: %d\n", state->bts_read);
	}

	state->bts_read += 1;
	msgb_free(in_msg);

	return 0;
}

static int ms_to_bts_l1_cb(struct osmo_prim_hdr *oph, void *_ctx)
{
	int rc;
	struct lapdm_polling_state *state = _ctx;
	printf("%s: MS(us) -> BTS prim message\n", __func__);

	/* i stuff it into the LAPDm channel of the BTS */
	rc = send(oph->msg, state->bts);
	msgb_free(oph->msg);
	return rc;
}

static int dequeue_prim(struct lapdm_entity *le, struct osmo_phsap_prim *pp,
			const char *queue_name)
{
	int rc;
	int l2_header_len;
	int l3_len = 0;

	/* Take message from queue */
	rc = lapdm_phsap_dequeue_prim(le, pp);

	fprintf(stderr, "dequeue: got rc %d: %s\n", rc,
		rc <= 0 ? strerror(-rc) : "-");

	if (rc < 0)
		return rc;

	l2_header_len = msgb_l2len(pp->oph.msg);
	if (msgb_l3(pp->oph.msg)) {
		l3_len = msgb_l3len(pp->oph.msg);
		l2_header_len -= l3_len;
	} else
		fprintf(stderr, "MSGB: L3 is undefined\n");

	if (l2_header_len < 0 || l2_header_len > pp->oph.msg->data_len) {
		fprintf(stderr,
			"MSGB inconsistent: data = %p, l2 = %p, l3 = %p, tail = %p\n",
			pp->oph.msg->data,
			pp->oph.msg->l2h,
			pp->oph.msg->l3h,
			pp->oph.msg->tail);
		l2_header_len = -1;
	}

	printf("Took message from %s queue: "
	       "L2 header size %d, L3 size %d, "
	       "SAP %#x, %d/%d, Link 0x%02x\n",
	       queue_name,
	       l2_header_len, l3_len,
	       pp->oph.sap, pp->oph.primitive, pp->oph.operation,
	       pp->u.data.link_id);
	printf("Message: %s\n", msgb_hexdump(pp->oph.msg));

	return rc;
}

static int ms_to_bts_tx_cb(struct msgb *msg, struct lapdm_entity *le, void *_ctx)
{
	struct lapdm_polling_state *state = _ctx;

	printf("%s: BTS->MS(us) message %d\n", __func__, msgb_length(msg));

	if (state->ms_read == 0) {
		struct abis_rsl_rll_hdr hdr;

		printf("MS: Verifying incoming primitive.\n");
		OSMO_ASSERT(msg->len == sizeof(struct abis_rsl_rll_hdr) + 3);

		/* verify the header */
		memset(&hdr, 0, sizeof(hdr));
		rsl_init_rll_hdr(&hdr, RSL_MT_EST_CONF);
		hdr.c.msg_discr |= ABIS_RSL_MDISC_TRANSP;
		OSMO_ASSERT(memcmp(msg->data, &hdr, sizeof(hdr)) == 0);

		/* Verify the added RSL_IE_L3_INFO but we have a bug here */
		OSMO_ASSERT(msg->data[6] == RSL_IE_L3_INFO);
		#warning "RSL_IE_L3_INFO 16 bit length is wrong"
		/* This should be okay but it is actually 0x0, 0x9c on ia-32 */
		/* OSMO_ASSERT(msg->data[7] == 0x0 && msg->data[8] == 0x0); */
	} else if (state->ms_read == 1) {
		printf("MS: Verifying incoming MM message: %d\n", msgb_l3len(msg));
		OSMO_ASSERT(msgb_l3len(msg) == 3);
		OSMO_ASSERT(memcmp(msg->l3h, &mm[12], msgb_l3len(msg)) == 0);
	} else {
		printf("MS: Do not know to verify: %d\n", state->ms_read);
	}

	state->ms_read += 1;
	msgb_free(msg);
	return 0;
}

static void test_lapdm_polling()
{
	printf("I do some very simple LAPDm test.\n");

	int rc;
	struct lapdm_polling_state test_state;
	struct osmo_phsap_prim pp;

	/* Configure LAPDm on both sides */
	struct lapdm_channel bts_to_ms_channel;
	struct lapdm_channel ms_to_bts_channel;
	memset(&bts_to_ms_channel, 0, sizeof(bts_to_ms_channel));
	memset(&ms_to_bts_channel, 0, sizeof(ms_to_bts_channel));

	memset(&test_state, 0, sizeof(test_state));
	test_state.bts = &bts_to_ms_channel;
	test_state.ms = &ms_to_bts_channel;

	/* BTS to MS in polling mode */
	lapdm_channel_init(&bts_to_ms_channel, LAPDM_MODE_BTS);
        lapdm_channel_set_flags(&bts_to_ms_channel, LAPDM_ENT_F_POLLING_ONLY);
        lapdm_channel_set_l1(&bts_to_ms_channel, NULL, &test_state);
        lapdm_channel_set_l3(&bts_to_ms_channel, bts_to_ms_tx_cb, &test_state);

	/* MS to BTS in direct mode */
	lapdm_channel_init(&ms_to_bts_channel, LAPDM_MODE_MS);
	lapdm_channel_set_l1(&ms_to_bts_channel, ms_to_bts_l1_cb, &test_state);
	lapdm_channel_set_l3(&ms_to_bts_channel, ms_to_bts_tx_cb, &test_state);

	/*
	 * We try to send messages from the MS to the BTS to the MS..
	 */
	/* 1. Start with MS -> BTS, BTS should have a pending message */
	printf("Establishing link.\n");
	lapdm_rslms_recvmsg(create_cm_serv_req(), &ms_to_bts_channel);

	/* 2. Poll on the BTS for sending out a confirmation */
	printf("\nConfirming\n");
	OSMO_ASSERT(test_state.bts_read == 1);
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(pp.oph.msg->data == pp.oph.msg->l2h);
	send(pp.oph.msg, &ms_to_bts_channel);
	msgb_free(pp.oph.msg);
	OSMO_ASSERT(test_state.ms_read == 1);

	/* 3. Send some data to the MS */
	printf("\nSending back to MS\n");
	lapdm_rslms_recvmsg(create_mm_id_req(), &bts_to_ms_channel);
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	send(pp.oph.msg, &ms_to_bts_channel);
	msgb_free(pp.oph.msg);
	OSMO_ASSERT(test_state.ms_read == 2);

	/* verify that there is nothing more to poll */
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	OSMO_ASSERT(rc < 0);

	/* 3. And back to the BTS */
	printf("\nSending back to BTS\n");
	OSMO_ASSERT(test_state.ms_read == 2);
	lapdm_rslms_recvmsg(create_dummy_data_req(), &ms_to_bts_channel);


	/* 4. And back to the MS, but let's move data/l2h apart */
	OSMO_ASSERT(test_state.bts_read == 2);
	OSMO_ASSERT(test_state.ms_read == 2);
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	send(pp.oph.msg, &ms_to_bts_channel);
	OSMO_ASSERT(test_state.ms_read == 2);
	msgb_free(pp.oph.msg);

	/* verify that there is nothing more to poll */
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	OSMO_ASSERT(rc < 0);
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_acch, &pp, "ACCH");
	OSMO_ASSERT(rc < 0);

	/* check sending an empty L3 message fails */
	rc = lapdm_rslms_recvmsg(create_empty_msg(), &bts_to_ms_channel);
	OSMO_ASSERT(rc == -1);
	OSMO_ASSERT(test_state.ms_read == 2);

	/* clean up */
	lapdm_channel_exit(&bts_to_ms_channel);
	lapdm_channel_exit(&ms_to_bts_channel);

	/* Check if exit is idempotent */
	lapdm_channel_exit(&bts_to_ms_channel);
	lapdm_channel_exit(&ms_to_bts_channel);
}

static void test_lapdm_contention_resolution()
{
	printf("I test contention resultion by having two mobiles collide and "
		"first mobile repeating SABM.\n");

	int rc;
	struct lapdm_polling_state test_state;
	struct osmo_phsap_prim pp;
	uint8_t *cm2;

	/* Configure LAPDm on both sides */
	struct lapdm_channel bts_to_ms_channel;
	memset(&bts_to_ms_channel, 0, sizeof(bts_to_ms_channel));

	memset(&test_state, 0, sizeof(test_state));
	test_state.bts = &bts_to_ms_channel;

	/* BTS to MS in polling mode */
	lapdm_channel_init(&bts_to_ms_channel, LAPDM_MODE_BTS);
	lapdm_channel_set_flags(&bts_to_ms_channel, LAPDM_ENT_F_POLLING_ONLY);
	lapdm_channel_set_l1(&bts_to_ms_channel, NULL, &test_state);
	lapdm_channel_set_l3(&bts_to_ms_channel, bts_to_ms_tx_cb, &test_state);

	/* Send SABM MS 1, we must get UA */
	send_sabm(&bts_to_ms_channel, 0, cm, sizeof(cm));
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, ua, ARRAY_SIZE(ua)) == 0);

	/* Send SABM MS 2, we must get nothing, due to collision */
	cm2 = malloc(sizeof(cm));
	memcpy(cm2, cm, sizeof(cm));
	cm2[0] += 1;
	send_sabm(&bts_to_ms_channel, 0, cm2, sizeof(cm2));
	free(cm2);
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	OSMO_ASSERT(rc == -ENODEV);

	/* Send SABM MS 1 again, we must get UA gain */
	send_sabm(&bts_to_ms_channel, 0, cm, sizeof(cm));
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, ua, ARRAY_SIZE(ua)) == 0);

	/* clean up */
	lapdm_channel_exit(&bts_to_ms_channel);

	/* idempotent */
	lapdm_channel_exit(&bts_to_ms_channel);
}

static void test_lapdm_early_release()
{
	printf("I test RF channel release of an unestablished channel.\n");

	int rc;
	struct lapdm_polling_state test_state;

	/* Configure LAPDm on both sides */
	struct lapdm_channel bts_to_ms_channel;
	memset(&bts_to_ms_channel, 0, sizeof(bts_to_ms_channel));

	memset(&test_state, 0, sizeof(test_state));
	test_state.bts = &bts_to_ms_channel;

	/* BTS to MS in polling mode */
	lapdm_channel_init(&bts_to_ms_channel, LAPDM_MODE_BTS);
	lapdm_channel_set_flags(&bts_to_ms_channel, LAPDM_ENT_F_POLLING_ONLY);
	lapdm_channel_set_l1(&bts_to_ms_channel, NULL, &test_state);
	lapdm_channel_set_l3(&bts_to_ms_channel, bts_to_ms_tx_cb, &test_state);

	/* Send the release request */
	rc = lapdm_rslms_recvmsg(create_rel_req(), &bts_to_ms_channel);
	OSMO_ASSERT(rc == -EINVAL);

	/* clean up */
	lapdm_channel_exit(&bts_to_ms_channel);

	/* Check if exit is idempotent */
	lapdm_channel_exit(&bts_to_ms_channel);
}

static void lapdm_establish(const uint8_t *est_req, size_t est_req_size)
{
	int rc;
	struct lapdm_polling_state test_state;
	struct osmo_phsap_prim pp;
	struct msgb *msg;

	/* Configure LAPDm on both sides */
	struct lapdm_channel bts_to_ms_channel;
	memset(&bts_to_ms_channel, 0, sizeof(bts_to_ms_channel));

	memset(&test_state, 0, sizeof(test_state));
	test_state.bts = &bts_to_ms_channel;

	/* BTS to MS in polling mode */
	lapdm_channel_init(&bts_to_ms_channel, LAPDM_MODE_BTS);
	lapdm_channel_set_flags(&bts_to_ms_channel, LAPDM_ENT_F_POLLING_ONLY);
	lapdm_channel_set_l1(&bts_to_ms_channel, NULL, &test_state);
	lapdm_channel_set_l3(&bts_to_ms_channel, bts_to_ms_tx_cb, &test_state);

	/* Send the release request */
	msg = create_est_req(est_req, est_req_size);
	rc = lapdm_rslms_recvmsg(msg, &bts_to_ms_channel);
	fprintf(stderr, "recvmsg: got rc %d: %s\n", rc, rc <= 0 ? strerror(-rc) : "???");
	OSMO_ASSERT(rc == 0);

	/* Take message from queue */
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	if (rc < 0)
		rc = dequeue_prim(&bts_to_ms_channel.lapdm_acch, &pp, "ACCH");

	CHECK_RC(rc);

	OSMO_ASSERT(pp.oph.msg->data == msgb_l2(pp.oph.msg));

	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	OSMO_ASSERT(rc < 0);
	rc = dequeue_prim(&bts_to_ms_channel.lapdm_acch, &pp, "ACCH");
	OSMO_ASSERT(rc < 0);

	/* clean up */
	lapdm_channel_exit(&bts_to_ms_channel);

	/* idempotent */
	lapdm_channel_exit(&bts_to_ms_channel);
}

static void test_lapdm_establishment()
{
	printf("I test RF channel establishment.\n");
	printf("Testing SAPI3/SDCCH\n");
	lapdm_establish(est_req_sdcch_sapi3, sizeof(est_req_sdcch_sapi3));
	printf("Testing SAPI3/SACCH\n");
	lapdm_establish(est_req_sacch_sapi3, sizeof(est_req_sacch_sapi3));
}


const uint8_t cm_chg[] = {
	0x01, 0x00, 0x49, 0x06, 0x16, 0x03, 0x33,
	0x59, 0xa6, 0x20, 0x0a, 0x20, 0x04, 0x04,
	0x2f, 0x65, 0x23, 0x02, 0x00, 0x24, 0x04
};

const uint8_t cm_chg_ack[] = {
	0x01, 0x21, 0x01
};

const uint8_t gprs_susp[] = {
	0x01, 0x02, 0x35, 0x06, 0x34, 0xe3, 0xd4,
	0xd2, 0x6f, 0x09, 0xf1, 0x07, 0x00, 0x01, 0x00, 0x02
};

const uint8_t cipher_cmd[] = {
	0x06, 0x35, 0x01
};

/* The cipher command we send to the MS after updating our N(R) */
const uint8_t cipher_cmd_out[] = {
	0x03, 0x40, 0x0d, 0x06, 0x35, 0x01
};

uint8_t cipher_compl[] = {
	0x01, 0x24, 0x09, 0x06, 0x32
};

uint8_t cipher_compl_ack[] = {
	0x01, 0x61, 0x01
};

static const uint8_t ua_sms[] = {
	0x0d, 0x73, 0x01
};

const uint8_t cp_data_1[] = {
	0x0d, 0x00, 0x53, 0x59, 0x01, 0x5c, 0x00,
	0x4c, 0x00, 0x06, 0x91, 0x86, 0x77, 0x07,
	0x00, 0xf9, 0x51, 0x11, 0x76, 0x05, 0x81, 0x29, 0x32
};

const uint8_t cp_data_1_ack[] = {
	0x0d, 0x21, 0x01
};

static int bts_to_ms_dummy_tx_cb(struct msgb *in_msg, struct lapdm_entity *le, void *_ctx)
{
	printf("%s: MS->BTS(us) message %d\n", __func__, msgb_length(in_msg));
	msgb_free(in_msg);

	return 0;
}

static void dump_queue(struct llist_head *head)
{
	struct msgb* msg;

	printf("\nDumping queue:\n");
	llist_for_each_entry(msg, head, list)
		printf("%s\n", msgb_hexdump(msg));
	printf("\n");
}

static void test_lapdm_desync()
{
	printf("I test if desync problems exist in LAPDm\n");

	int rc;
	struct osmo_phsap_prim pp;

	/* Configure LAPDm on both sides */
	struct lapdm_channel bts_to_ms_channel;
	memset(&bts_to_ms_channel, 0, sizeof(bts_to_ms_channel));

	/* BTS to MS in polling mode */
	lapdm_channel_init(&bts_to_ms_channel, LAPDM_MODE_BTS);
	lapdm_channel_set_flags(&bts_to_ms_channel, LAPDM_ENT_F_POLLING_ONLY);
	lapdm_channel_set_l1(&bts_to_ms_channel, NULL, NULL);
	lapdm_channel_set_l3(&bts_to_ms_channel, bts_to_ms_dummy_tx_cb, NULL);
	struct lapdm_datalink *dl = lapdm_datalink_for_sapi(&bts_to_ms_channel.lapdm_dcch, 0);
	dl->mctx.dl = dl;
	dl->dl.lctx.dl = &dl->dl;

	/* Send SABM MS 1, we must get UA */
	printf("\nEstablishing SAPI=0\n");
	send_sabm(&bts_to_ms_channel, 0, cm, sizeof(cm));

	dump_queue(&dl->dl.tx_queue);

	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, ua, ARRAY_SIZE(ua)) == 0);

	printf("\nSending Classmark Change\n");
	send_buf(cm_chg, sizeof(cm_chg), &bts_to_ms_channel);
	dump_queue(&dl->dl.tx_queue);

	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, cm_chg_ack, ARRAY_SIZE(cm_chg_ack)) == 0);

	printf("\nEnqueueing Ciphering Mode Command\n");
	enqueue_buf(cipher_cmd, sizeof(cipher_cmd), 0, &bts_to_ms_channel);
	dump_queue(&dl->dl.tx_queue);

	printf("\nSending GPRS Suspend Request\n");
	send_buf(gprs_susp, sizeof(gprs_susp), &bts_to_ms_channel);
	dump_queue(&dl->dl.tx_queue);

	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, cipher_cmd_out, ARRAY_SIZE(cipher_cmd_out)) == 0);

	printf("\nSending Cipher Mode Complete\n");
	send_buf(cipher_compl, sizeof(cipher_compl), &bts_to_ms_channel);
	dump_queue(&dl->dl.tx_queue);

	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, cipher_compl_ack, ARRAY_SIZE(cipher_compl_ack)) == 0);

	printf("\nEstablishing SAPI=3\n");
	send_sabm(&bts_to_ms_channel, 3, NULL, 0);
	dump_queue(&dl->dl.tx_queue);

	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, ua_sms, ARRAY_SIZE(ua_sms)) == 0);

	printf("\nSending CP-DATA\n");
	send_buf(cp_data_1, sizeof(cp_data_1), &bts_to_ms_channel);
	dump_queue(&dl->dl.tx_queue);

	rc = dequeue_prim(&bts_to_ms_channel.lapdm_dcch, &pp, "DCCH");
	CHECK_RC(rc);
	OSMO_ASSERT(memcmp(pp.oph.msg->l2h, cp_data_1_ack, ARRAY_SIZE(cp_data_1_ack)) == 0);

	/* clean up */
	lapdm_channel_exit(&bts_to_ms_channel);

	/* Check if exit is idempotent */
	lapdm_channel_exit(&bts_to_ms_channel);
}

int main(int argc, char **argv)
{
	osmo_init_logging(&info);

	/* Prevent the test from segfaulting */
	dummy_l1_header_len = 0;
	test_lapdm_polling();

	dummy_l1_header_len = 3;
	test_lapdm_early_release();
	test_lapdm_contention_resolution();
	test_lapdm_establishment();
	test_lapdm_desync();

	printf("Success.\n");

	return 0;
}