summaryrefslogtreecommitdiffstats
path: root/src/libbsc/chan_alloc.c
blob: c0bdc1be90c68d36e07a1938286445b8dec8d79f (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
/* GSM Channel allocation routines
 *
 * (C) 2008 by Harald Welte <laforge@gnumonks.org>
 * (C) 2008, 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
 *
 * All Rights Reserved
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include <openbsc/gsm_subscriber.h>
#include <openbsc/chan_alloc.h>
#include <openbsc/abis_nm.h>
#include <openbsc/abis_rsl.h>
#include <openbsc/debug.h>
#include <openbsc/signal.h>

#include <osmocom/core/talloc.h>

static int ts_is_usable(struct gsm_bts_trx_ts *ts)
{
	/* FIXME: How does this behave for BS-11 ? */
	if (is_ipaccess_bts(ts->trx->bts)) {
		if (!nm_is_running(&ts->mo.nm_state))
			return 0;
	}

	return 1;
}

int trx_is_usable(struct gsm_bts_trx *trx)
{
	/* FIXME: How does this behave for BS-11 ? */
	if (is_ipaccess_bts(trx->bts)) {
		if (!nm_is_running(&trx->mo.nm_state) ||
		    !nm_is_running(&trx->bb_transc.mo.nm_state))
			return 0;
	}

	return 1;
}

struct gsm_bts_trx_ts *ts_c0_alloc(struct gsm_bts *bts,
				   enum gsm_phys_chan_config pchan)
{
	struct gsm_bts_trx *trx = bts->c0;
	struct gsm_bts_trx_ts *ts = &trx->ts[0];

	if (pchan != GSM_PCHAN_CCCH &&
	    pchan != GSM_PCHAN_CCCH_SDCCH4)
		return NULL;

	if (ts->pchan != GSM_PCHAN_NONE)
		return NULL;

	ts->pchan = pchan;

	return ts;
}

/* Allocate a physical channel (TS) */
struct gsm_bts_trx_ts *ts_alloc(struct gsm_bts *bts,
				enum gsm_phys_chan_config pchan)
{
	int j;
	struct gsm_bts_trx *trx;

	llist_for_each_entry(trx, &bts->trx_list, list) {
		int from, to;

		if (!trx_is_usable(trx))
			continue;

		/* the following constraints are pure policy,
		 * no requirement to put this restriction in place */
		if (trx == bts->c0) {
			/* On the first TRX we run one CCCH and one SDCCH8 */
			switch (pchan) {
			case GSM_PCHAN_CCCH:
			case GSM_PCHAN_CCCH_SDCCH4:
				from = 0; to = 0;
				break;
			case GSM_PCHAN_TCH_F:
			case GSM_PCHAN_TCH_H:
				from = 1; to = 7;
				break;
			case GSM_PCHAN_SDCCH8_SACCH8C:
			default:
				return NULL;
			}
		} else {
			/* Every secondary TRX is configured for TCH/F
			 * and TCH/H only */
			switch (pchan) {
			case GSM_PCHAN_SDCCH8_SACCH8C:
				from = 1; to = 1;
			case GSM_PCHAN_TCH_F:
			case GSM_PCHAN_TCH_H:
				from = 1; to = 7;
				break;
			default:
				return NULL;
			}
		}

		for (j = from; j <= to; j++) {
			struct gsm_bts_trx_ts *ts = &trx->ts[j];

			if (!ts_is_usable(ts))
				continue;

			if (ts->pchan == GSM_PCHAN_NONE) {
				ts->pchan = pchan;
				/* set channel attribute on OML */
				abis_nm_set_channel_attr(ts, abis_nm_chcomb4pchan(pchan));
				return ts;
			}
		}
	}
	return NULL;
}

/* Free a physical channel (TS) */
void ts_free(struct gsm_bts_trx_ts *ts)
{
	ts->pchan = GSM_PCHAN_NONE;
}

static const uint8_t subslots_per_pchan[] = {
	[GSM_PCHAN_NONE] = 0,
	[GSM_PCHAN_CCCH] = 0,
	[GSM_PCHAN_CCCH_SDCCH4] = 4,
	[GSM_PCHAN_TCH_F] = 1,
	[GSM_PCHAN_TCH_H] = 2,
	[GSM_PCHAN_SDCCH8_SACCH8C] = 8,
	/* FIXME: what about dynamic TCH_F_TCH_H ? */
	[GSM_PCHAN_TCH_F_PDCH] = 1,
};

static struct gsm_lchan *
_lc_find_trx(struct gsm_bts_trx *trx, enum gsm_phys_chan_config pchan)
{
	struct gsm_bts_trx_ts *ts;
	int j, ss;

	if (!trx_is_usable(trx))
		return NULL;

	for (j = 0; j < 8; j++) {
		ts = &trx->ts[j];
		if (!ts_is_usable(ts))
			continue;
		/* ip.access dynamic TCH/F + PDCH combination */
		if (ts->pchan == GSM_PCHAN_TCH_F_PDCH &&
		    pchan == GSM_PCHAN_TCH_F) {
			/* we can only consider such a dynamic channel
			 * if the PDCH is currently inactive */
			if (ts->flags & TS_F_PDCH_MODE)
				continue;
		} else if (ts->pchan != pchan)
			continue;
		/* check if all sub-slots are allocated yet */
		for (ss = 0; ss < subslots_per_pchan[pchan]; ss++) {
			struct gsm_lchan *lc = &ts->lchan[ss];
			if (lc->type == GSM_LCHAN_NONE &&
			    lc->state == LCHAN_S_NONE)
				return lc;
		}
	}

	return NULL;
}

static struct gsm_lchan *
_lc_find_bts(struct gsm_bts *bts, enum gsm_phys_chan_config pchan)
{
	struct gsm_bts_trx *trx;
	struct gsm_bts_trx_ts *ts;
	struct gsm_lchan *lc;

	if (bts->chan_alloc_reverse) {
		llist_for_each_entry_reverse(trx, &bts->trx_list, list) {
			lc = _lc_find_trx(trx, pchan);
			if (lc)
				return lc;
		}
	} else {
		llist_for_each_entry(trx, &bts->trx_list, list) {
			lc = _lc_find_trx(trx, pchan);
			if (lc)
				return lc;
		}
	}

	/* we cannot allocate more of these */
	if (pchan == GSM_PCHAN_CCCH_SDCCH4)
		return NULL;

	/* if we've reached here, we need to allocate a new physical
	 * channel for the logical channel type requested */
	ts = ts_alloc(bts, pchan);
	if (!ts) {
		/* no more radio resources */
		return NULL;
	}
	return &ts->lchan[0];
}

/* Allocate a logical channel */
struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type,
			      int allow_bigger)
{
	struct gsm_lchan *lchan = NULL;
	enum gsm_phys_chan_config first, second;

	switch (type) {
	case GSM_LCHAN_SDCCH:
		if (bts->chan_alloc_reverse) {
			first = GSM_PCHAN_SDCCH8_SACCH8C;
			second = GSM_PCHAN_CCCH_SDCCH4;
		} else {
			first = GSM_PCHAN_CCCH_SDCCH4;
			second = GSM_PCHAN_SDCCH8_SACCH8C;
		}

		lchan = _lc_find_bts(bts, first);
		if (lchan == NULL)
			lchan = _lc_find_bts(bts, second);

		/* allow to assign bigger channels */
		if (allow_bigger) {
			if (lchan == NULL) {
				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_H);
				type = GSM_LCHAN_TCH_H;
			}

			if (lchan == NULL) {
				lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
				type = GSM_LCHAN_TCH_F;
			}
		}
		break;
	case GSM_LCHAN_TCH_F:
		lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
		break;
	case GSM_LCHAN_TCH_H:
		lchan =_lc_find_bts(bts, GSM_PCHAN_TCH_H);
		/* If we don't have TCH/H available, fall-back to TCH/F */
		if (!lchan) {
			lchan = _lc_find_bts(bts, GSM_PCHAN_TCH_F);
			type = GSM_LCHAN_TCH_F;
		}
		break;
	default:
		LOGP(DRLL, LOGL_ERROR, "Unknown gsm_chan_t %u\n", type);
	}

	if (lchan) {
		lchan->type = type;

		/* clear sapis */
		memset(lchan->sapis, 0, ARRAY_SIZE(lchan->sapis));

		/* clear multi rate config */
		memset(&lchan->mr_conf, 0, sizeof(lchan->mr_conf));
	} else {
		struct challoc_signal_data sig;
		sig.bts = bts;
		sig.type = type;
		osmo_signal_dispatch(SS_CHALLOC, S_CHALLOC_ALLOC_FAIL, &sig);
	}

	return lchan;
}

/* Free a logical channel */
void lchan_free(struct gsm_lchan *lchan)
{
	struct challoc_signal_data sig;
	int i;

	sig.type = lchan->type;
	lchan->type = GSM_LCHAN_NONE;


	if (lchan->conn) {
		struct lchan_signal_data sig;

		/* We might kill an active channel... */
		sig.lchan = lchan;
		sig.mr = NULL;
		osmo_signal_dispatch(SS_LCHAN, S_LCHAN_UNEXPECTED_RELEASE, &sig);
	}


	/* stop the timer */
	osmo_timer_del(&lchan->T3101);

	/* clear cached measuement reports */
	lchan->meas_rep_idx = 0;
	for (i = 0; i < ARRAY_SIZE(lchan->meas_rep); i++) {
		lchan->meas_rep[i].flags = 0;
		lchan->meas_rep[i].nr = 0;
	}
	for (i = 0; i < ARRAY_SIZE(lchan->neigh_meas); i++)
		lchan->neigh_meas[i].arfcn = 0;

	if (lchan->rqd_ref) {
		talloc_free(lchan->rqd_ref);
		lchan->rqd_ref = NULL;
		lchan->rqd_ta = 0;
	}

	sig.lchan = lchan;
	sig.bts = lchan->ts->trx->bts;
	osmo_signal_dispatch(SS_CHALLOC, S_CHALLOC_FREED, &sig);

	if (lchan->conn) {
		LOGP(DRLL, LOGL_ERROR, "the subscriber connection should be gone.\n");
		lchan->conn = NULL;
	}

	lchan->sach_deact = 0;
	lchan->release_reason = 0;

	/* FIXME: ts_free() the timeslot, if we're the last logical
	 * channel using it */
}

/*
 * There was an error with the TRX and we need to forget
 * any state so that a lchan can be allocated again after
 * the trx is fully usable.
 *
 * This should be called after lchan_free to force a channel
 * be available for allocation again. This means that this
 * method will stop the "delay after error"-timer and set the
 * state to LCHAN_S_NONE.
 */
void lchan_reset(struct gsm_lchan *lchan)
{
	osmo_timer_del(&lchan->T3101);
	osmo_timer_del(&lchan->T3111);
	osmo_timer_del(&lchan->error_timer);

	lchan->type = GSM_LCHAN_NONE;
	lchan->state = LCHAN_S_NONE;
}

/* release the next allocated SAPI or return 0 */
static int _lchan_release_next_sapi(struct gsm_lchan *lchan)
{
	int sapi;

	for (sapi = 1; sapi < ARRAY_SIZE(lchan->sapis); ++sapi) {
		uint8_t link_id;
		if (lchan->sapis[sapi] == LCHAN_SAPI_UNUSED)
			continue;

		link_id = sapi;
		if (lchan->type == GSM_LCHAN_TCH_F || lchan->type == GSM_LCHAN_TCH_H)
			link_id |= 0x40;
		rsl_release_request(lchan, link_id, lchan->release_reason);
		return 0;
	}

	return 1;
}

/* Drive the release process of the lchan */
static void _lchan_handle_release(struct gsm_lchan *lchan)
{
	/* Ask for SAPI != 0 to be freed first and stop if we need to wait */
	if (_lchan_release_next_sapi(lchan) == 0)
		return;

	if (lchan->sach_deact) {
		gsm48_send_rr_release(lchan);
		return;
	}

	rsl_release_request(lchan, 0, lchan->release_reason);
	rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);
}

/* called from abis rsl */
int rsl_lchan_rll_release(struct gsm_lchan *lchan, uint8_t link_id)
{
	if (lchan->state != LCHAN_S_REL_REQ)
		return -1;

	if ((link_id & 0x7) != 0)
		_lchan_handle_release(lchan);
	return 0;
}

/* Consider releasing the channel now */
int lchan_release(struct gsm_lchan *lchan, int sach_deact, int reason)
{
	DEBUGP(DRLL, "%s starting release sequence\n", gsm_lchan_name(lchan));
	rsl_lchan_set_state(lchan, LCHAN_S_REL_REQ);

	lchan->conn = NULL;
	lchan->release_reason = reason;
	lchan->sach_deact = sach_deact;
	_lchan_handle_release(lchan);
	return 1;
}

static struct gsm_lchan* lchan_find(struct gsm_bts *bts, struct gsm_subscriber *subscr) {
	struct gsm_bts_trx *trx;
	int ts_no, lchan_no;

	llist_for_each_entry(trx, &bts->trx_list, list) {
		for (ts_no = 0; ts_no < 8; ++ts_no) {
			for (lchan_no = 0; lchan_no < TS_MAX_LCHAN; ++lchan_no) {
				struct gsm_lchan *lchan =
					&trx->ts[ts_no].lchan[lchan_no];
				if (lchan->conn && subscr == lchan->conn->subscr)
					return lchan;
			}
		}
	}

	return NULL;
}

struct gsm_subscriber_connection *connection_for_subscr(struct gsm_subscriber *subscr)
{
	struct gsm_bts *bts;
	struct gsm_network *net = subscr->net;
	struct gsm_lchan *lchan;

	llist_for_each_entry(bts, &net->bts_list, list) {
		lchan = lchan_find(bts, subscr);
		if (lchan)
			return lchan->conn;
	}

	return NULL;
}

void bts_chan_load(struct pchan_load *cl, const struct gsm_bts *bts)
{
	struct gsm_bts_trx *trx;

	llist_for_each_entry(trx, &bts->trx_list, list) {
		int i;

		/* skip administratively deactivated tranxsceivers */
		if (!nm_is_running(&trx->mo.nm_state) ||
		    !nm_is_running(&trx->bb_transc.mo.nm_state))
			continue;

		for (i = 0; i < ARRAY_SIZE(trx->ts); i++) {
			struct gsm_bts_trx_ts *ts = &trx->ts[i];
			struct load_counter *pl = &cl->pchan[ts->pchan];
			int j;

			/* skip administratively deactivated timeslots */
			if (!nm_is_running(&ts->mo.nm_state))
				continue;

			for (j = 0; j < subslots_per_pchan[ts->pchan]; j++) {
				struct gsm_lchan *lchan = &ts->lchan[j];

				pl->total++;

				switch (lchan->state) {
				case LCHAN_S_NONE:
					break;
				default:
					pl->used++;
					break;
				}
			}
		}
	}
}

void network_chan_load(struct pchan_load *pl, struct gsm_network *net)
{
	struct gsm_bts *bts;

	memset(pl, 0, sizeof(*pl));

	llist_for_each_entry(bts, &net->bts_list, list)
		bts_chan_load(pl, bts);
}