aboutsummaryrefslogtreecommitdiffstats
path: root/src/osmo-bsc/assignment_fsm.c
blob: c17b55509c6b8c31c940b4dec2c4969d26eec093 (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
/* osmo-bsc BSSMAP Assignment procedure implementation.
 *
 * (C) 2018 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
 * All Rights Reserved
 *
 * Author: Neels Hofmeyr <neels@hofmeyr.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <osmocom/gsm/gsm0808.h>

#include <osmocom/mgcp_client/mgcp_client_fsm.h>

#include <osmocom/bsc/debug.h>
#include <osmocom/bsc/gsm_data.h>
#include <osmocom/bsc/gsm_timers.h>
#include <osmocom/bsc/lchan_fsm.h>
#include <osmocom/bsc/mgw_endpoint_fsm.h>
#include <osmocom/bsc/bsc_subscr_conn_fsm.h>
#include <osmocom/bsc/osmo_bsc_lcls.h>
#include <osmocom/bsc/bsc_msc_data.h>
#include <osmocom/bsc/gsm_08_08.h>
#include <osmocom/bsc/lchan_select.h>
#include <osmocom/bsc/abis_rsl.h>

#include <osmocom/bsc/assignment_fsm.h>

static struct osmo_fsm assignment_fsm;

struct gsm_subscriber_connection *assignment_fi_conn(struct osmo_fsm_inst *fi)
{
	OSMO_ASSERT(fi);
	OSMO_ASSERT(fi->fsm == &assignment_fsm);
	OSMO_ASSERT(fi->priv);
	return fi->priv;
}

static const struct state_timeout assignment_fsm_timeouts[32] = {
	[ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE] = { .T=10 },
	[ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE] = { .keep_timer=true },
	[ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED] = { .keep_timer=true },
	[ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC] = { .T=23042 },
};

/* Transition to a state, using the T timer defined in assignment_fsm_timeouts.
 * The actual timeout value is in turn obtained from network->T_defs.
 * Assumes local variable fi exists. */
#define assignment_fsm_state_chg(state) \
	fsm_inst_state_chg_T(fi, state, \
			     assignment_fsm_timeouts, \
			     ((struct gsm_subscriber_connection*)(fi->priv))->network->T_defs, \
			     5)

/* Log failure and transition to ASSIGNMENT_ST_FAILURE, which triggers the appropriate actions. */
#define assignment_fail(cause, fmt, args...) do { \
		struct gsm_subscriber_connection *_conn = fi->priv; \
		_conn->assignment.failure_cause = cause; \
		LOG_ASSIGNMENT(_conn, LOGL_ERROR, "Assignment failed in state %s, cause %s: " fmt "\n", \
			       osmo_fsm_inst_state_name(fi), gsm0808_cause_name(cause), ## args); \
		assignment_count_result(BSC_CTR_ASSIGNMENT_ERROR); \
		on_assignment_failure(_conn); \
	} while(0)

/* Assume presence of local var 'conn' as struct gsm_subscriber_connection */
#define assignment_count(counter) do { \
		LOG_ASSIGNMENT(conn, LOGL_DEBUG, "incrementing rate counter: %s %s\n", \
			       bsc_ctr_description[counter].name, \
			       bsc_ctr_description[counter].description); \
		rate_ctr_inc(&conn->network->bsc_ctrs->ctr[counter]); \
	} while(0)

#define assignment_count_result(counter) do { \
		if (!conn->assignment.result_rate_ctr_done) { \
			assignment_count(counter); \
			conn->assignment.result_rate_ctr_done = true; \
		} else \
			LOG_ASSIGNMENT(conn, LOGL_DEBUG, \
				       "result rate counter already recorded, NOT counting as: %s %s\n", \
				       bsc_ctr_description[counter].name, \
				       bsc_ctr_description[counter].description); \
	} while(0)

void assignment_reset(struct gsm_subscriber_connection *conn)
{
	if (conn->assignment.new_lchan) {
		struct gsm_lchan *lchan = conn->assignment.new_lchan;
		conn->assignment.new_lchan = NULL;
		lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
	}

	if (conn->assignment.created_ci_for_msc) {
		gscon_forget_mgw_endpoint_ci(conn, conn->assignment.created_ci_for_msc);
		/* If this is the last endpoint released, the mgw_endpoint_fsm will terminate and tell
		 * the gscon about it. */
		mgw_endpoint_ci_dlcx(conn->assignment.created_ci_for_msc);
	}

	conn->assignment = (struct assignment_fsm_data){
		.fi = conn->assignment.fi, /* The FSM shall clear itself when it's done. */
	};
}

static void on_assignment_failure(struct gsm_subscriber_connection *conn)
{
	struct msgb *resp = gsm0808_create_assignment_failure(conn->assignment.failure_cause, NULL);

	if (!resp)
		LOG_ASSIGNMENT(conn, LOGL_ERROR, "Unable to compose BSSMAP Assignment Failure message\n");
	else
		gscon_sigtran_send(conn, resp);

	/* If assignment failed as early as in assignment_fsm_start(), there may not be an fi yet. */
	if (conn->assignment.fi) {
		LOG_ASSIGNMENT(conn, LOGL_ERROR, "Assignment failed\n");
		osmo_fsm_inst_term(conn->assignment.fi, OSMO_FSM_TERM_ERROR, 0);
	}
}

static void send_assignment_complete(struct gsm_subscriber_connection *conn)
{
	int rc;
	struct gsm0808_speech_codec sc;
	struct gsm0808_speech_codec *sc_ptr = NULL;
	struct sockaddr_storage addr_local;
	struct sockaddr_storage *addr_local_p = NULL;
	int perm_spch = 0;
	uint8_t chosen_channel;
	struct msgb *resp;
	struct gsm_lchan *lchan = conn->lchan;
	struct osmo_fsm_inst *fi = conn->fi;

	chosen_channel = gsm0808_chosen_channel(lchan->type, lchan->tch_mode);
	if (!chosen_channel) {
		assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
				"Unable to compose Chosen Channel for mode=%s type=%s",
				get_value_string(gsm48_chan_mode_names, lchan->tch_mode),
				gsm_lchant_name(lchan->type));
		return;
	}

	/* Generate voice related fields */
	if (conn->assignment.requires_voice_stream) {
		perm_spch = gsm0808_permitted_speech(lchan->type, lchan->tch_mode);

		if (gscon_is_aoip(conn)) {
			if (!mgwep_ci_get_crcx_info_to_sockaddr(conn->user_plane.mgw_endpoint_ci_msc,
								&addr_local)) {
				assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
						"Unable to compose RTP address of MGW -> MSC");
				return;
			}
			addr_local_p = &addr_local;
		}

		/* Only AoIP networks include a speech codec (choosen) in the
		 * assignment complete message. */
		if (gscon_is_aoip(conn)) {
			/* Extrapolate speech codec from speech mode */
			gsm0808_speech_codec_from_chan_type(&sc, perm_spch);
			sc.cfg = conn->lchan->activate.info.s15_s0;
			sc_ptr = &sc;
		}
	}

	resp = gsm0808_create_ass_compl2(lchan->abis_ip.ass_compl.rr_cause,
					 chosen_channel,
					 lchan->encr.alg_id, perm_spch,
					 addr_local_p, sc_ptr, NULL, lcls_get_status(conn));

	if (!resp) {
		assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
				"Unable to compose Assignment Complete message");
		return;
	}

	rc = gscon_sigtran_send(conn, resp);
	if (rc) {
		assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
				"Unable send Assignment Complete message: rc=%d %s",
				rc, strerror(-rc));
		return;
	}
}

static void assignment_success(struct gsm_subscriber_connection *conn)
{
	/* Take on the new lchan */
	gscon_change_primary_lchan(conn, conn->assignment.new_lchan);
	conn->assignment.new_lchan = NULL;

	/* apply LCLS configuration (if any) */
	lcls_apply_config(conn);

	send_assignment_complete(conn);
	/* If something went wrong during send_assignment_complete(), the fi will be gone from
	 * error handling in there. Almost a success, but then again the whole thing failed. */
	if (!conn->assignment.fi) {
		/* The lchan was ready, and we failed to tell the MSC about it. By releasing this lchan,
		 * the conn will notice that its primary lchan is gone and should clean itself up. */
		lchan_release(conn->lchan, true, true, RSL_ERR_EQUIPMENT_FAIL);
		return;
	}

	/* Rembered this only for error handling: should assignment fail, assignment_reset() will release
	 * the MGW endpoint right away. If successful, the conn continues to use the endpoint. */
	conn->assignment.created_ci_for_msc = NULL;

	/* New RTP information is now accepted */
	conn->user_plane.msc_assigned_cic = conn->assignment.req.msc_assigned_cic;
	osmo_strlcpy(conn->user_plane.msc_assigned_rtp_addr, conn->assignment.req.msc_rtp_addr,
		     sizeof(conn->user_plane.msc_assigned_rtp_addr));
	conn->user_plane.msc_assigned_rtp_port = conn->assignment.req.msc_rtp_port;

	LOG_ASSIGNMENT(conn, LOGL_DEBUG, "Assignment successful\n");
	osmo_fsm_inst_term(conn->assignment.fi, OSMO_FSM_TERM_REGULAR, 0);

	assignment_count_result(BSC_CTR_ASSIGNMENT_COMPLETED);
}

static void assignment_fsm_update_id(struct gsm_subscriber_connection *conn)
{
	struct gsm_lchan *new_lchan = conn->assignment.new_lchan;
	if (!new_lchan) {
		osmo_fsm_inst_update_id(conn->assignment.fi, conn->fi->id);
		return;
	}

	osmo_fsm_inst_update_id_f(conn->assignment.fi, "%s_%u-%u-%u-%s%s%s-%u",
				  conn->fi->id,
				  new_lchan->ts->trx->bts->nr, new_lchan->ts->trx->nr, new_lchan->ts->nr,
				  gsm_pchan_id(new_lchan->ts->pchan_on_init),
				  (new_lchan->ts->pchan_on_init == new_lchan->ts->pchan_is)? "" : "as",
				  (new_lchan->ts->pchan_on_init == new_lchan->ts->pchan_is)? ""
					  : gsm_pchan_id(new_lchan->ts->pchan_is),
				  new_lchan->nr);
}

static bool lchan_type_compat_with_mode(enum gsm_chan_t type, const struct channel_mode_and_rate *ch_mode_rate)
{
	enum gsm48_chan_mode chan_mode = ch_mode_rate->chan_mode;
	bool full_rate = ch_mode_rate->full_rate;

	switch (chan_mode) {
	case GSM48_CMODE_SIGN:
		switch (type) {
		case GSM_LCHAN_TCH_F:
		case GSM_LCHAN_TCH_H:
		case GSM_LCHAN_SDCCH:
			return true;
		default:
			return false;
		}

	case GSM48_CMODE_SPEECH_V1:
	case GSM48_CMODE_SPEECH_AMR:
	case GSM48_CMODE_DATA_3k6:
	case GSM48_CMODE_DATA_6k0:
		/* these services can all run on TCH/H, but we may have
		 * an explicit override by the 'full_rate' argument */
		switch (type) {
		case GSM_LCHAN_TCH_F:
			return full_rate;
		case GSM_LCHAN_TCH_H:
			return !full_rate;
		default:
			return false;
		}

	case GSM48_CMODE_DATA_12k0:
	case GSM48_CMODE_DATA_14k5:
	case GSM48_CMODE_SPEECH_EFR:
		/* these services all explicitly require a TCH/F */
		return type == GSM_LCHAN_TCH_F;

	default:
		return false;
	}
}

void assignment_fsm_init()
{
	OSMO_ASSERT(osmo_fsm_register(&assignment_fsm) == 0);
}

static int check_requires_voice(bool *requires_voice, enum gsm48_chan_mode chan_mode)
{
	*requires_voice = false;

	switch (chan_mode) {
	case GSM48_CMODE_SPEECH_V1:
	case GSM48_CMODE_SPEECH_EFR:
	case GSM48_CMODE_SPEECH_AMR:
		*requires_voice = true;
		break;
	case GSM48_CMODE_SIGN:
		*requires_voice = false;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

/* Check if the incoming assignment requests requires a voice stream or not,
 * we will look at the preferred and the alternate channel mode and also make
 * sure that both are consistent. */
static int check_requires_voice_stream(struct gsm_subscriber_connection *conn)
{
	bool result_requires_voice_alt;
	bool result_requires_voice_pref;
	struct assignment_request *req = &conn->assignment.req;
	struct osmo_fsm_inst *fi = conn->fi;
	int rc;

	/* When the assignment request indicates that there is an alternate
	 * rate available (e.g. "Full or Half rate channel, Half rate
	 * preferred..."), then both must be either voice or either signalling,
	 * a mismatch is not permitted */

	/* Check the prefered setting */
	rc = check_requires_voice(&result_requires_voice_pref, req->ch_mode_rate_pref.chan_mode);
	if (rc < 0) {
		assignment_fail(GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_NOT_SUPP,
				"Prefered channel mode not supported: %s",
				gsm48_chan_mode_name(req->ch_mode_rate_pref.chan_mode));
		return -EINVAL;
	}
	conn->assignment.requires_voice_stream = result_requires_voice_pref;

	/* If there is an alternate setting, check that one as well */
	if (!req->ch_mode_rate_alt_present)
		return 0;
	rc = check_requires_voice(&result_requires_voice_alt, req->ch_mode_rate_alt.chan_mode);
	if (rc < 0) {
		assignment_fail(GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_NOT_SUPP,
				"Alternate channel mode not supported: %s",
				gsm48_chan_mode_name(req->ch_mode_rate_alt.chan_mode));
		return -EINVAL;
	}

	/* Make sure both settings match */
	if (result_requires_voice_pref != result_requires_voice_alt) {
		assignment_fail(GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_NOT_SUPP,
				"Inconsistent channel modes: %s != %s",
				gsm48_chan_mode_name(req->ch_mode_rate_pref.chan_mode),
				gsm48_chan_mode_name(req->ch_mode_rate_alt.chan_mode));
		return -EINVAL;
	}

	return 0;
}

/* Check if the conn is already associated with an lchan. If yes, we will check
 * if that lchan is compatible with the preferred rate/codec. If the lchan
 * turns out to be incompatible we try with the alternate rate/codec. */
static bool reuse_existing_lchan(struct gsm_subscriber_connection *conn)
{
	struct assignment_request *req = &conn->assignment.req;

	if (!conn->lchan)
		return false;

	/* Check if the currently existing lchan is compatible with the
	 * preferred rate/codec. */
	if (lchan_type_compat_with_mode(conn->lchan->type, &req->ch_mode_rate_pref))
		conn->lchan->ch_mode_rate = req->ch_mode_rate_pref;
	else if (req->ch_mode_rate_alt_present
		 && lchan_type_compat_with_mode(conn->lchan->type, &req->ch_mode_rate_alt))
		conn->lchan->ch_mode_rate = req->ch_mode_rate_alt;
	else
		return false;

	if (conn->lchan->tch_mode != conn->lchan->ch_mode_rate.chan_mode) {
		/* FIXME: send Channel Mode Modify to put the current lchan in the right mode, and kick
		 * off its RTP stream setup code path. See gsm48_lchan_modify() and
		 * gsm48_rx_rr_modif_ack(), and see lchan_fsm.h LCHAN_EV_CHAN_MODE_MODIF_* */
		LOG_ASSIGNMENT(conn, LOGL_DEBUG,
			       "Current lchan would be compatible, but Channel Mode Modify is not implemented\n");
		return false;
	}

	return true;
}

void assignment_fsm_start(struct gsm_subscriber_connection *conn, struct gsm_bts *bts,
			  struct assignment_request *req)
{
	struct osmo_fsm_inst *fi;
	struct lchan_activate_info info;

	OSMO_ASSERT(conn);
	OSMO_ASSERT(conn->fi);
	OSMO_ASSERT(!conn->assignment.fi);
	OSMO_ASSERT(!conn->assignment.new_lchan);

	assignment_count(BSC_CTR_ASSIGNMENT_ATTEMPTED);

	fi = osmo_fsm_inst_alloc_child(&assignment_fsm, conn->fi, GSCON_EV_ASSIGNMENT_END);
	OSMO_ASSERT(fi);
	conn->assignment.fi = fi;
	fi->priv = conn;

	/* Create a copy of the request data and use that copy from now on. */
	conn->assignment.req = *req;
	req = &conn->assignment.req;

	/* Check if we need a voice stream. If yes, set the approriate struct
	 * members in conn */
	if (check_requires_voice_stream(conn) < 0)
		return;

	/* There may be an already existing lchan, if yes, try to work with
	 * the existing lchan */
	if (reuse_existing_lchan(conn)) {
		LOG_ASSIGNMENT(conn, LOGL_DEBUG,
			       "Current lchan is compatible with requested chan_mode,"
			       " sending BSSMAP Assignment Complete directly."
			       " requested chan_mode=%s; current lchan is %s\n",
			       gsm48_chan_mode_name(conn->lchan->ch_mode_rate.chan_mode),
			       gsm_lchan_name(conn->lchan));

		send_assignment_complete(conn);
		/* If something went wrong during send_assignment_complete(), the fi will be gone from
		 * error handling in there. */
		if (conn->assignment.fi) {
			assignment_count_result(BSC_CTR_ASSIGNMENT_COMPLETED);
			osmo_fsm_inst_term(conn->assignment.fi, OSMO_FSM_TERM_REGULAR, 0);
		}
		return;
	}

	/* Try to allocate a new lchan with the preferred codec/rate choice */
	conn->assignment.new_lchan =
	    lchan_select_by_chan_mode(bts, req->ch_mode_rate_pref.chan_mode, req->ch_mode_rate_pref.full_rate);
	conn->lchan->ch_mode_rate = req->ch_mode_rate_pref;

	/* In case the lchan allocation fails, we try with the alternat codec/
	 * rate choice (if possible) */
	if (!conn->assignment.new_lchan && req->ch_mode_rate_alt_present) {
		conn->assignment.new_lchan =
		    lchan_select_by_chan_mode(bts, req->ch_mode_rate_alt.chan_mode, req->ch_mode_rate_alt.full_rate);
		conn->lchan->ch_mode_rate = req->ch_mode_rate_alt;
	}

	/* Check whether the lchan allocation was successful or not and tear
	 * down the assignment in case of failure. */
	if (!conn->assignment.new_lchan) {
		assignment_count_result(BSC_CTR_ASSIGNMENT_NO_CHANNEL);
		assignment_fail(GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE,
				"BSSMAP Assignment Command:"
				" No lchan available for: preferred=%s%s / alternate=%s%s\n",
				gsm48_chan_mode_name(req->ch_mode_rate_pref.chan_mode),
				req->ch_mode_rate_pref.full_rate ? ",FR" : ",HR",
				req->ch_mode_rate_alt_present ?
					gsm48_chan_mode_name(req->ch_mode_rate_alt.chan_mode) : "none",
				req->ch_mode_rate_alt_present ?
					(req->ch_mode_rate_alt.full_rate ? ",FR" : ",HR") : "");
		return;
	}

	assignment_fsm_update_id(conn);
	LOG_ASSIGNMENT(conn, LOGL_INFO, "Starting Assignment: chan_mode=%s, full_rate=%d,"
		       " aoip=%s MSC-rtp=%s:%u\n",
		       gsm48_chan_mode_name(conn->lchan->ch_mode_rate.chan_mode),
		       conn->lchan->ch_mode_rate.full_rate,
		       req->aoip ? "yes" : "no", req->msc_rtp_addr, req->msc_rtp_port);

	assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE);
	info = (struct lchan_activate_info){
		.activ_for = FOR_ASSIGNMENT,
		.for_conn = conn,
		.chan_mode = conn->lchan->ch_mode_rate.chan_mode,
		.s15_s0 = conn->lchan->ch_mode_rate.s15_s0,
		.requires_voice_stream = conn->assignment.requires_voice_stream,
		.msc_assigned_cic = req->msc_assigned_cic,
		.re_use_mgw_endpoint_from_lchan = conn->lchan,
	};
	lchan_activate(conn->assignment.new_lchan, &info);
}

static void assignment_fsm_wait_lchan(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	switch (event) {

	case ASSIGNMENT_EV_LCHAN_ACTIVE:
		if (data != conn->assignment.new_lchan)
			return;

		/* The TS may have changed its pchan_is */
		assignment_fsm_update_id(conn);

		assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE);
		return;

	default:
		OSMO_ASSERT(false);
	}
}

static void assignment_fsm_wait_rr_ass_complete_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
	int rc;
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);

	rc = gsm48_send_rr_ass_cmd(conn->lchan, conn->assignment.new_lchan,
				   conn->lchan->ms_power);

	if (rc)
		assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE, "Unable to send RR Assignment Command");
}

static uint8_t get_cause(void *data)
{
	if (data)
		return *(uint8_t*)data;
	return GSM0808_CAUSE_EQUIPMENT_FAILURE;
}

static void assignment_fsm_wait_rr_ass_complete(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	switch (event) {

	case ASSIGNMENT_EV_RR_ASSIGNMENT_COMPLETE:
		assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED);
		return;

	case ASSIGNMENT_EV_LCHAN_ESTABLISHED:
		LOG_ASSIGNMENT(conn, LOGL_DEBUG, "lchan established, still waiting for RR Assignment Complete\n");
		/* The lchan is already done with all of its RTP setup. We will notice the lchan state
		 * being LCHAN_ST_ESTABLISHED in assignment_fsm_wait_lchan_established_onenter(). */
		return;

	case ASSIGNMENT_EV_RR_ASSIGNMENT_FAIL:
		assignment_count_result(BSC_CTR_ASSIGNMENT_FAILED);
		assignment_fail(get_cause(data), "Rx RR Assignment Failure");
		return;

	default:
		OSMO_ASSERT(false);
	}
}

static void assignment_fsm_post_lchan_established(struct osmo_fsm_inst *fi);

static void assignment_fsm_wait_lchan_established_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	/* Do we still need to wait for the RTP stream at all? */
	if (lchan_state_is(conn->assignment.new_lchan, LCHAN_ST_ESTABLISHED)) {
		LOG_ASSIGNMENT(conn, LOGL_DEBUG, "lchan fully established, no need to wait\n");
		assignment_fsm_post_lchan_established(fi);
	}
}

static void assignment_fsm_wait_lchan_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
	switch (event) {

	case ASSIGNMENT_EV_LCHAN_ESTABLISHED:
		assignment_fsm_post_lchan_established(fi);
		return;

	default:
		OSMO_ASSERT(false);
	}
}

static void assignment_fsm_post_lchan_established(struct osmo_fsm_inst *fi)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	if (conn->assignment.requires_voice_stream)
		assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC);
	else
		assignment_success(conn);
}

static void assignment_fsm_wait_mgw_endpoint_to_msc_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);

	OSMO_ASSERT(conn->assignment.requires_voice_stream);

	LOG_ASSIGNMENT(conn, LOGL_DEBUG,
		       "Connecting MGW endpoint to the MSC's RTP port: %s:%u\n",
		       conn->assignment.req.msc_rtp_addr,
		       conn->assignment.req.msc_rtp_port);

	if (!gscon_connect_mgw_to_msc(conn,
				      conn->assignment.new_lchan,
				      conn->assignment.req.msc_rtp_addr,
				      conn->assignment.req.msc_rtp_port,
				      fi,
				      ASSIGNMENT_EV_MSC_MGW_OK,
				      ASSIGNMENT_EV_MSC_MGW_FAIL,
				      NULL,
				      &conn->assignment.created_ci_for_msc)) {
		assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
				"Unable to connect MGW endpoint to the MSC side");
		return;
	}
}

static void assignment_fsm_wait_mgw_endpoint_to_msc(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	switch (event) {

	case ASSIGNMENT_EV_MSC_MGW_OK:
		/* For AoIP, we created the MGW endpoint. Ensure it is really there, and log it. */
		if (gscon_is_aoip(conn)) {
			const struct mgcp_conn_peer *mgw_info;
			mgw_info = mgwep_ci_get_rtp_info(conn->user_plane.mgw_endpoint_ci_msc);
			if (!mgw_info) {
				assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
						"Unable to retrieve RTP port info allocated by MGW for"
						" the MSC side.");
				return;
			}
			LOG_ASSIGNMENT(conn, LOGL_DEBUG, "MGW's MSC side CI: %s:%u\n",
				       mgw_info->addr, mgw_info->port);
		}
		assignment_success(conn);
		return;

	case ASSIGNMENT_EV_MSC_MGW_FAIL:
		assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
				"Unable to connect MGW endpoint to the MSC side");
		return;

	default:
		OSMO_ASSERT(false);
	}
}

#define S(x)	(1 << (x))

static const struct osmo_fsm_state assignment_fsm_states[] = {
	[ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE] = {
		.name = "WAIT_LCHAN_ACTIVE",
		.action = assignment_fsm_wait_lchan,
		.in_event_mask = 0
			| S(ASSIGNMENT_EV_LCHAN_ACTIVE)
			,
		.out_state_mask = 0
			| S(ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE)
			| S(ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE)
			,
	},
	[ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE] = {
		.name = "WAIT_RR_ASS_COMPLETE",
		.onenter = assignment_fsm_wait_rr_ass_complete_onenter,
		.action = assignment_fsm_wait_rr_ass_complete,
		.in_event_mask = 0
			| S(ASSIGNMENT_EV_RR_ASSIGNMENT_COMPLETE)
			| S(ASSIGNMENT_EV_RR_ASSIGNMENT_FAIL)
			| S(ASSIGNMENT_EV_LCHAN_ESTABLISHED)
			,
		.out_state_mask = 0
			| S(ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED)
			,
	},
	[ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED] = {
		.name = "WAIT_LCHAN_ESTABLISHED",
		.onenter = assignment_fsm_wait_lchan_established_onenter,
		.action = assignment_fsm_wait_lchan_established,
		.in_event_mask = 0
			| S(ASSIGNMENT_EV_LCHAN_ESTABLISHED)
			,
		.out_state_mask = 0
			| S(ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC)
			,
	},
	[ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC] = {
		.name = "WAIT_MGW_ENDPOINT_TO_MSC",
		.onenter = assignment_fsm_wait_mgw_endpoint_to_msc_onenter,
		.action = assignment_fsm_wait_mgw_endpoint_to_msc,
		.in_event_mask = 0
			| S(ASSIGNMENT_EV_MSC_MGW_OK)
			| S(ASSIGNMENT_EV_MSC_MGW_FAIL)
			,
	},
};

static const struct value_string assignment_fsm_event_names[] = {
	OSMO_VALUE_STRING(ASSIGNMENT_EV_LCHAN_ACTIVE),
	OSMO_VALUE_STRING(ASSIGNMENT_EV_LCHAN_ESTABLISHED),
	OSMO_VALUE_STRING(ASSIGNMENT_EV_LCHAN_ERROR),
	OSMO_VALUE_STRING(ASSIGNMENT_EV_MSC_MGW_OK),
	OSMO_VALUE_STRING(ASSIGNMENT_EV_MSC_MGW_FAIL),
	OSMO_VALUE_STRING(ASSIGNMENT_EV_RR_ASSIGNMENT_COMPLETE),
	OSMO_VALUE_STRING(ASSIGNMENT_EV_RR_ASSIGNMENT_FAIL),
	OSMO_VALUE_STRING(ASSIGNMENT_EV_CONN_RELEASING),
	{}
};

void assignment_fsm_allstate_action(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	switch (event) {

	case ASSIGNMENT_EV_CONN_RELEASING:
		assignment_count_result(BSC_CTR_ASSIGNMENT_STOPPED);
		osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REQUEST, 0);
		return;

	case ASSIGNMENT_EV_LCHAN_ERROR:
		if (data != conn->assignment.new_lchan)
			return;
		assignment_fail(conn->assignment.new_lchan->activate.gsm0808_error_cause,
				"Failed to activate lchan %s",
				gsm_lchan_name(conn->assignment.new_lchan));
		return;

	default:
		return;
	}
}

int assignment_fsm_timer_cb(struct osmo_fsm_inst *fi)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	assignment_count_result(BSC_CTR_ASSIGNMENT_TIMEOUT);
	assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE, "Timeout");
	return 0;
}

void assignment_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
{
	struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
	assignment_reset(conn);
	conn->assignment.fi = NULL;
}

static struct osmo_fsm assignment_fsm = {
	.name = "assignment",
	.states = assignment_fsm_states,
	.num_states = ARRAY_SIZE(assignment_fsm_states),
	.log_subsys = DAS,
	.event_names = assignment_fsm_event_names,
	.allstate_action = assignment_fsm_allstate_action,
	.allstate_event_mask = 0
		| S(ASSIGNMENT_EV_CONN_RELEASING)
		| S(ASSIGNMENT_EV_LCHAN_ERROR)
		,
	.timer_cb = assignment_fsm_timer_cb,
	.cleanup = assignment_fsm_cleanup,
};