aboutsummaryrefslogtreecommitdiffstats
path: root/src/gsm_04_08.c
blob: fe1637e9a4ffd33ee5614ef38e88895bae70670e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
/* GSM Mobile Radio Interface Layer 3 messages on the A-bis interface 
 * 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 */

/* (C) 2008-2009 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 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <netinet/in.h>

#include <openbsc/db.h>
#include <openbsc/msgb.h>
#include <openbsc/tlv.h>
#include <openbsc/debug.h>
#include <openbsc/gsm_data.h>
#include <openbsc/gsm_subscriber.h>
#include <openbsc/gsm_04_11.h>
#include <openbsc/gsm_04_08.h>
#include <openbsc/abis_rsl.h>
#include <openbsc/chan_alloc.h>
#include <openbsc/paging.h>
#include <openbsc/signal.h>
#include <openbsc/trau_mux.h>

#define GSM48_ALLOC_SIZE	1024
#define GSM48_ALLOC_HEADROOM	128

static const struct tlv_definition rsl_att_tlvdef = {
	.def = {
		[GSM48_IE_MOBILE_ID]	= { TLV_TYPE_TLV },
		[GSM48_IE_NAME_LONG]	= { TLV_TYPE_TLV },
		[GSM48_IE_NAME_SHORT]	= { TLV_TYPE_TLV },
		[GSM48_IE_UTC]		= { TLV_TYPE_TV },
		[GSM48_IE_NET_TIME_TZ]	= { TLV_TYPE_FIXED, 7 },
		[GSM48_IE_LSA_IDENT]	= { TLV_TYPE_TLV },

		[GSM48_IE_BEARER_CAP]	= { TLV_TYPE_TLV },
		[GSM48_IE_CAUSE]	= { TLV_TYPE_TLV },
		[GSM48_IE_CC_CAP]	= { TLV_TYPE_TLV },
		[GSM48_IE_ALERT]	= { TLV_TYPE_TLV },
		[GSM48_IE_FACILITY]	= { TLV_TYPE_TLV },
		[GSM48_IE_PROGR_IND]	= { TLV_TYPE_TLV },
		[GSM48_IE_AUX_STATUS]	= { TLV_TYPE_TLV },
		[GSM48_IE_KPD_FACILITY]	= { TLV_TYPE_TV },
		[GSM48_IE_SIGNAL]	= { TLV_TYPE_TV },
		[GSM48_IE_CONN_NUM]	= { TLV_TYPE_TLV },
		[GSM48_IE_CONN_SUBADDR]	= { TLV_TYPE_TLV },
		[GSM48_IE_CALLING_BCD]	= { TLV_TYPE_TLV },
		[GSM48_IE_CALLING_SUB]	= { TLV_TYPE_TLV },
		[GSM48_IE_CALLED_BCD]	= { TLV_TYPE_TLV },
		[GSM48_IE_CALLED_SUB]	= { TLV_TYPE_TLV },
		[GSM48_IE_REDIR_BCD]	= { TLV_TYPE_TLV },
		[GSM48_IE_REDIR_SUB]	= { TLV_TYPE_TLV },
		[GSM48_IE_LOWL_COMPAT]	= { TLV_TYPE_TLV },
		[GSM48_IE_HIGHL_COMPAT]	= { TLV_TYPE_TLV },
		[GSM48_IE_USER_USER]	= { TLV_TYPE_TLV },
		[GSM48_IE_SS_VERS]	= { TLV_TYPE_TLV },
		[GSM48_IE_MORE_DATA]	= { TLV_TYPE_T },
		[GSM48_IE_CLIR_SUPP]	= { TLV_TYPE_T },
		[GSM48_IE_CLIR_INVOC]	= { TLV_TYPE_T },
		[GSM48_IE_REV_C_SETUP]	= { TLV_TYPE_T },
		/* FIXME: more elements */
	},
};

static const char *rr_cause_names[] = {
	[GSM48_RR_CAUSE_NORMAL]			= "Normal event",
	[GSM48_RR_CAUSE_ABNORMAL_UNSPEC]	= "Abnormal release, unspecified",
	[GSM48_RR_CAUSE_ABNORMAL_UNACCT]	= "Abnormal release, channel unacceptable",
	[GSM48_RR_CAUSE_ABNORMAL_TIMER]		= "Abnormal release, timer expired",
	[GSM48_RR_CAUSE_ABNORMAL_NOACT]		= "Abnormal release, no activity on radio path",
	[GSM48_RR_CAUSE_PREMPTIVE_REL]		= "Preemptive release",
	[GSM48_RR_CAUSE_HNDOVER_IMP]		= "Handover impossible, timing advance out of range",
	[GSM48_RR_CAUSE_CHAN_MODE_UNACCT]	= "Channel mode unacceptable",
	[GSM48_RR_CAUSE_FREQ_NOT_IMPL]		= "Frequency not implemented",
	[GSM48_RR_CAUSE_CALL_CLEARED]		= "Call already cleared",
	[GSM48_RR_CAUSE_SEMANT_INCORR]		= "Semantically incorrect message",
	[GSM48_RR_CAUSE_INVALID_MAND_INF]	= "Invalid mandatory information",
	[GSM48_RR_CAUSE_MSG_TYPE_N]		= "Message type non-existant or not implemented",
	[GSM48_RR_CAUSE_MSG_TYPE_N_COMPAT]	= "Message type not compatible with protocol state",
	[GSM48_RR_CAUSE_COND_IE_ERROR]		= "Conditional IE error",
	[GSM48_RR_CAUSE_NO_CELL_ALLOC_A]	= "No cell allocation available",
	[GSM48_RR_CAUSE_PROT_ERROR_UNSPC]	= "Protocol error unspecified",
};

static char strbuf[64];

static const char *rr_cause_name(u_int8_t cause)
{
	if (cause < ARRAY_SIZE(rr_cause_names) &&
	    rr_cause_names[cause])
		return rr_cause_names[cause];

	snprintf(strbuf, sizeof(strbuf), "0x%02x", cause);
	return strbuf;
}

static int gsm48_tx_simple(struct gsm_lchan *lchan,
			   u_int8_t pdisc, u_int8_t msg_type);
static void schedule_reject(struct gsm_lchan *lchan);

struct gsm_lai {
	u_int16_t mcc;
	u_int16_t mnc;
	u_int16_t lac;
};

static int authorize_everonye = 0;
void gsm0408_allow_everyone(int everyone)
{
	printf("Allowing everyone?\n");
	authorize_everonye = everyone;
}

static int reject_cause = 0;
void gsm0408_set_reject_cause(int cause)
{
	reject_cause = cause;
}

static int authorize_subscriber(struct gsm_loc_updating_operation *loc,
				struct gsm_subscriber *subscriber)
{
	if (!subscriber)
		return 0;

	/*
	 * Do not send accept yet as more information should arrive. Some
	 * phones will not send us the information and we will have to check
	 * what we want to do with that.
	 */
	if (loc && (loc->waiting_for_imsi || loc->waiting_for_imei))
		return 0;

	if (authorize_everonye)
		return 1;

	return subscriber->authorized;
}

static void release_loc_updating_req(struct gsm_lchan *lchan)
{
	if (!lchan->loc_operation)
		return;

	del_timer(&lchan->loc_operation->updating_timer);
	free(lchan->loc_operation);
	lchan->loc_operation = 0;
	put_lchan(lchan);
}

static void allocate_loc_updating_req(struct gsm_lchan *lchan)
{
	use_lchan(lchan);
	release_loc_updating_req(lchan);

	lchan->loc_operation = (struct gsm_loc_updating_operation *)
				malloc(sizeof(*lchan->loc_operation));
	memset(lchan->loc_operation, 0, sizeof(*lchan->loc_operation));
}

static void to_bcd(u_int8_t *bcd, u_int16_t val)
{
	bcd[2] = val % 10;
	val = val / 10;
	bcd[1] = val % 10;
	val = val / 10;
	bcd[0] = val % 10;
	val = val / 10;
}

void gsm0408_generate_lai(struct gsm48_loc_area_id *lai48, u_int16_t mcc, 
			 u_int16_t mnc, u_int16_t lac)
{
	u_int8_t bcd[3];

	to_bcd(bcd, mcc);
	lai48->digits[0] = bcd[0] | (bcd[1] << 4);
	lai48->digits[1] = bcd[2];

	to_bcd(bcd, mnc);
	/* FIXME: do we need three-digit MNC? See Table 10.5.3 */
#if 0
	lai48->digits[1] |= bcd[2] << 4;
	lai48->digits[2] = bcd[0] | (bcd[1] << 4);
#else
	lai48->digits[1] |= 0xf << 4;
	lai48->digits[2] = bcd[1] | (bcd[2] << 4);
#endif
	
	lai48->lac = htons(lac);
}

#define TMSI_LEN	5
#define MID_TMSI_LEN	(TMSI_LEN + 2)

int generate_mid_from_tmsi(u_int8_t *buf, u_int32_t tmsi)
{
	u_int32_t *tptr = (u_int32_t *) &buf[3];

	buf[0] = GSM48_IE_MOBILE_ID;
	buf[1] = TMSI_LEN;
	buf[2] = 0xf0 | GSM_MI_TYPE_TMSI;
	*tptr = htonl(tmsi);

	return 7;
}

static const char bcd_num_digits[] = {
	'0', '1', '2', '3', '4', '5', '6', '7', 
	'8', '9', '*', '#', 'a', 'b', 'c', '\0'
};

/* decode a 'called party BCD number' as in 10.5.4.7 */
u_int8_t decode_bcd_number(char *output, int output_len, const u_int8_t *bcd_lv)
{
	u_int8_t in_len = bcd_lv[0];
	int i;

	if (in_len < 1)
		return 0;

	for (i = 2; i <= in_len; i++) {
		/* lower nibble */
		output_len--;
		if (output_len <= 1)
			break;
		*output++ = bcd_num_digits[bcd_lv[i] & 0xf];

		/* higher nibble */
		output_len--;
		if (output_len <= 1)
			break;
		*output++ = bcd_num_digits[bcd_lv[i] >> 4];
	}
	if (output_len >= 1)
		*output++ = '\0';

	/* return number type / calling plan */
	return bcd_lv[1] & 0x3f;
}

/* convert a single ASCII character to call-control BCD */
static int asc_to_bcd(const char asc)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(bcd_num_digits); i++) {
		if (bcd_num_digits[i] == asc)
			return i;
	}
	return -EINVAL;
}

/* convert a ASCII phone number to 'called party BCD number' */
int encode_bcd_number(u_int8_t *bcd_lv, u_int8_t max_len,
		      u_int8_t type, const char *input)
{
	int in_len = strlen(input);
	int i;
	u_int8_t *bcd_cur = bcd_lv + 2;

	if (in_len/2 + 1 > max_len)
		return -EIO;

	/* two digits per byte, plus type byte */
	bcd_lv[0] = in_len/2 + 1;
	if (in_len % 2)
		bcd_lv[0]++;

	/* if the caller wants to create a valid 'calling party BCD
	 * number', then the extension bit MUST NOT be set.  For the
	 * 'called party BCD number' it MUST be set. *sigh */
	bcd_lv[1] = type;

	for (i = 0; i < in_len; i++) {
		int rc = asc_to_bcd(input[i]);
		if (rc < 0)
			return rc;
		if (i % 2 == 0)
			*bcd_cur = rc;	
		else
			*bcd_cur++ |= (rc << 4);
	}
	/* append padding nibble in case of odd length */
	if (i % 2)
		*bcd_cur++ |= 0xf0;

	/* return how many bytes we used */
	return (bcd_cur - bcd_lv);
}

struct msgb *gsm48_msgb_alloc(void)
{
	return msgb_alloc_headroom(GSM48_ALLOC_SIZE, GSM48_ALLOC_HEADROOM);
}

int gsm48_sendmsg(struct msgb *msg)
{
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msg->data;

	if (msg->lchan) {
		msg->trx = msg->lchan->ts->trx;

		if ((gh->proto_discr & GSM48_PDISC_MASK) == GSM48_PDISC_CC) {
			/* Send a 04.08 call control message, add transaction
			 * ID and TI flag */
			gh->proto_discr |= msg->lchan->call.transaction_id;

			/* GSM 04.07 Section 11.2.3.1.3 */
			switch (msg->lchan->call.type) {
			case GSM_CT_MO:
				gh->proto_discr |= 0x80;
				break;
			case GSM_CT_MT:
				break;
			case GSM_CT_NONE:
				break;
			}
		}
	}

	msg->l3h = msg->data;

	return rsl_data_request(msg, 0);
}


/* Chapter 9.2.14 : Send LOCATION UPDATING REJECT */
int gsm0408_loc_upd_rej(struct gsm_lchan *lchan, u_int8_t cause)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh;
	
	msg->lchan = lchan;

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_LOC_UPD_REJECT;
	gh->data[0] = cause;

	DEBUGP(DMM, "-> LOCATION UPDATING REJECT on channel: %d\n", lchan->nr);
	
	return gsm48_sendmsg(msg);
}

/* Chapter 9.2.13 : Send LOCATION UPDATE ACCEPT */
int gsm0408_loc_upd_acc(struct gsm_lchan *lchan, u_int32_t tmsi)
{
	struct gsm_bts *bts = lchan->ts->trx->bts;
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh;
	struct gsm48_loc_area_id *lai;
	u_int8_t *mid;
	int ret;
	
	msg->lchan = lchan;

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_LOC_UPD_ACCEPT;

	lai = (struct gsm48_loc_area_id *) msgb_put(msg, sizeof(*lai));
	gsm0408_generate_lai(lai, bts->network->country_code,
		     bts->network->network_code, bts->location_area_code);

	mid = msgb_put(msg, MID_TMSI_LEN);
	generate_mid_from_tmsi(mid, tmsi);

	DEBUGP(DMM, "-> LOCATION UPDATE ACCEPT\n");

	ret = gsm48_sendmsg(msg);

	ret = gsm48_tx_mm_info(lchan);

	return ret;
}

static char bcd2char(u_int8_t bcd)
{
	if (bcd < 0xa)
		return '0' + bcd;
	else
		return 'A' + (bcd - 0xa);
}

/* Convert Mobile Identity (10.5.1.4) to string */
static int mi_to_string(char *string, int str_len, u_int8_t *mi, int mi_len)
{
	int i;
	u_int8_t mi_type;
	char *str_cur = string;
	u_int32_t tmsi;

	mi_type = mi[0] & GSM_MI_TYPE_MASK;

	switch (mi_type) {
	case GSM_MI_TYPE_NONE:
		break;
	case GSM_MI_TYPE_TMSI:
		/* Table 10.5.4.3, reverse generate_mid_from_tmsi */
		if (mi_len == TMSI_LEN && mi[0] == (0xf0 | GSM_MI_TYPE_TMSI)) {
			memcpy(&tmsi, &mi[1], 4);
			tmsi = ntohl(tmsi);
			return snprintf(string, str_len, "%u", tmsi);
		}
		break;
	case GSM_MI_TYPE_IMSI:
	case GSM_MI_TYPE_IMEI:
	case GSM_MI_TYPE_IMEISV:
		*str_cur++ = bcd2char(mi[0] >> 4);
		
                for (i = 1; i < mi_len; i++) {
			if (str_cur + 2 >= string + str_len)
				return str_cur - string;
			*str_cur++ = bcd2char(mi[i] & 0xf);
			/* skip last nibble in last input byte when GSM_EVEN */
			if( (i != mi_len-1) || (mi[0] & GSM_MI_ODD))
				*str_cur++ = bcd2char(mi[i] >> 4);
		}
		break;
	default:
		break;
	}
	*str_cur++ = '\0';

	return str_cur - string;
}

/* Transmit Chapter 9.2.10 Identity Request */
static int mm_tx_identity_req(struct gsm_lchan *lchan, u_int8_t id_type)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh;

	msg->lchan = lchan;

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_ID_REQ;
	gh->data[0] = id_type;

	return gsm48_sendmsg(msg);
}

#define MI_SIZE 32

/* Parse Chapter 9.2.11 Identity Response */
static int mm_rx_id_resp(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm_lchan *lchan = msg->lchan;
	u_int8_t mi_type = gh->data[1] & GSM_MI_TYPE_MASK;
	char mi_string[MI_SIZE];
	u_int32_t tmsi;

	mi_to_string(mi_string, sizeof(mi_string), &gh->data[1], gh->data[0]);
	DEBUGP(DMM, "IDENTITY RESPONSE: mi_type=0x%02x MI(%s)\n",
		mi_type, mi_string);

	/*
	 * Rogue messages could trick us but so is life
	 */
	put_lchan(lchan);

	switch (mi_type) {
	case GSM_MI_TYPE_IMSI:
		if (!lchan->subscr)
			lchan->subscr = db_create_subscriber(mi_string);
		if (lchan->loc_operation)
			lchan->loc_operation->waiting_for_imsi = 0;
		break;
	case GSM_MI_TYPE_IMEI:
	case GSM_MI_TYPE_IMEISV:
		/* update subscribe <-> IMEI mapping */
		if (lchan->subscr)
			db_subscriber_assoc_imei(lchan->subscr, mi_string);
		if (lchan->loc_operation)
			lchan->loc_operation->waiting_for_imei = 0;
		break;
	}

	/* Check if we can let the mobile station enter */
	if (authorize_subscriber(lchan->loc_operation, lchan->subscr)) {
		db_subscriber_alloc_tmsi(lchan->subscr);
		tmsi = strtoul(lchan->subscr->tmsi, NULL, 10);
		release_loc_updating_req(lchan);
		return gsm0408_loc_upd_acc(msg->lchan, tmsi);
	}

	return 0;
}


static void loc_upd_rej_cb(void *data)
{
	struct gsm_lchan *lchan = data;

	release_loc_updating_req(lchan);
	gsm0408_loc_upd_rej(lchan, reject_cause);
	lchan_auto_release(lchan);
}

static void schedule_reject(struct gsm_lchan *lchan)
{
	lchan->loc_operation->updating_timer.cb = loc_upd_rej_cb;
	lchan->loc_operation->updating_timer.data = lchan;
	schedule_timer(&lchan->loc_operation->updating_timer, 5, 0);
}

static const char *lupd_name(u_int8_t type)
{
	switch (type) {
	case GSM48_LUPD_NORMAL:
		return "NORMAL";
	case GSM48_LUPD_PERIODIC:
		return "PEROIDOC";
	case GSM48_LUPD_IMSI_ATT:
		return "IMSI ATTACH";
	default:
		return "UNKNOWN";
	}
}

#define MI_SIZE 32
/* Chapter 9.2.15: Receive Location Updating Request */
static int mm_rx_loc_upd_req(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm_bts *bts = msg->trx->bts;
	struct gsm48_loc_upd_req *lu;
	struct gsm_subscriber *subscr;
	struct gsm_lchan *lchan = msg->lchan;
	u_int8_t mi_type;
	u_int32_t tmsi;
	char mi_string[MI_SIZE];
	int rc;

 	lu = (struct gsm48_loc_upd_req *) gh->data;

	mi_type = lu->mi[0] & GSM_MI_TYPE_MASK;

	mi_to_string(mi_string, sizeof(mi_string), lu->mi, lu->mi_len);

	DEBUGP(DMM, "LUPDREQ: mi_type=0x%02x MI(%s) type=%s ", mi_type, mi_string,
		lupd_name(lu->type));

	allocate_loc_updating_req(lchan);

	switch (mi_type) {
	case GSM_MI_TYPE_IMSI:
		/* we always want the IMEI, too */
		use_lchan(lchan);
		rc = mm_tx_identity_req(lchan, GSM_MI_TYPE_IMEI);
		lchan->loc_operation->waiting_for_imei = 1;

		/* look up subscriber based on IMSI */
		subscr = db_create_subscriber(mi_string);
		break;
	case GSM_MI_TYPE_TMSI:
		/* we always want the IMEI, too */
		use_lchan(lchan);
		rc = mm_tx_identity_req(lchan, GSM_MI_TYPE_IMEI);
		lchan->loc_operation->waiting_for_imei = 1;

		/* look up the subscriber based on TMSI, request IMSI if it fails */
		subscr = subscr_get_by_tmsi(mi_string);
		if (!subscr) {
			/* send IDENTITY REQUEST message to get IMSI */
			use_lchan(lchan);
			rc = mm_tx_identity_req(lchan, GSM_MI_TYPE_IMSI);
			lchan->loc_operation->waiting_for_imsi = 1;
		}
		break;
	case GSM_MI_TYPE_IMEI:
	case GSM_MI_TYPE_IMEISV:
		/* no sim card... FIXME: what to do ? */
		DEBUGP(DMM, "unimplemented mobile identity type\n");
		break;
	default:	
		DEBUGP(DMM, "unknown mobile identity type\n");
		break;
	}

	lchan->subscr = subscr;

	/*
	 * Schedule the reject timer and check if we can let the
	 * subscriber into our network immediately or if we need to wait
	 * for identity responses.
	 */
	schedule_reject(lchan);
	if (!authorize_subscriber(lchan->loc_operation, subscr))
		return 0;

	db_subscriber_alloc_tmsi(subscr);
	subscr_update(subscr, bts, GSM_SUBSCRIBER_UPDATE_ATTACHED);

	tmsi = strtoul(subscr->tmsi, NULL, 10);

	release_loc_updating_req(lchan);
	return gsm0408_loc_upd_acc(lchan, tmsi);
}

/* 9.1.5 Channel mode modify */
int gsm48_tx_chan_mode_modify(struct gsm_lchan *lchan, u_int8_t mode)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
	struct gsm48_chan_mode_modify *cmm =
		(struct gsm48_chan_mode_modify *) msgb_put(msg, sizeof(*cmm));
	u_int16_t arfcn = lchan->ts->trx->arfcn & 0x3ff;

	DEBUGP(DRR, "-> CHANNEL MODE MODIFY mode=0x%02x\n", mode);

	msg->lchan = lchan;
	gh->proto_discr = GSM48_PDISC_RR;
	gh->msg_type = GSM48_MT_RR_CHAN_MODE_MODIF;

	/* fill the channel information element, this code
	 * should probably be shared with rsl_rx_chan_rqd() */
	cmm->chan_desc.chan_nr = lchan2chan_nr(lchan);
	cmm->chan_desc.h0.tsc = lchan->ts->trx->bts->tsc;
	cmm->chan_desc.h0.h = 0;
	cmm->chan_desc.h0.arfcn_high = arfcn >> 8;
	cmm->chan_desc.h0.arfcn_low = arfcn & 0xff;
	cmm->mode = mode;

	return gsm48_sendmsg(msg);
}

/* Section 9.2.15a */
int gsm48_tx_mm_info(struct gsm_lchan *lchan)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh;
	struct gsm_network *net = lchan->ts->trx->bts->network;
	u_int8_t *ptr8;
	u_int16_t *ptr16;
	int name_len;
	int i;

	msg->lchan = lchan;

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_INFO;

	if (net->name_long) {
		name_len = strlen(net->name_long);
		/* 10.5.3.5a */
		ptr8 = msgb_put(msg, 3);
		ptr8[0] = GSM48_IE_NAME_LONG;
		ptr8[1] = name_len*2 +1;
		ptr8[2] = 0x90; /* UCS2, no spare bits, no CI */

		ptr16 = (u_int16_t *) msgb_put(msg, name_len*2);
		for (i = 0; i < name_len; i++)
			ptr16[i] = htons(net->name_long[i]);

		/* FIXME: Use Cell Broadcast, not UCS-2, since
		 * UCS-2 is only supported by later revisions of the spec */
	}

	if (net->name_short) {
		name_len = strlen(net->name_short);
		/* 10.5.3.5a */
		ptr8 = (u_int8_t *) msgb_put(msg, 3);
		ptr8[0] = GSM48_IE_NAME_LONG;
		ptr8[1] = name_len*2 + 1;
		ptr8[2] = 0x90; /* UCS2, no spare bits, no CI */

		ptr16 = (u_int16_t *) msgb_put(msg, name_len*2);
		for (i = 0; i < name_len; i++)
			ptr16[i] = htons(net->name_short[i]);
	}

#if 0
	/* move back to the top */
	time_t cur_t;
	struct tm* cur_time;
	int tz15min;
	/* Section 10.5.3.9 */
	cur_t = time(NULL);
	cur_time = gmtime(cur_t);
	ptr8 = msgb_put(msg, 8);
	ptr8[0] = GSM48_IE_NET_TIME_TZ;
	ptr8[1] = to_bcd8(cur_time->tm_year % 100);
	ptr8[2] = to_bcd8(cur_time->tm_mon);
	ptr8[3] = to_bcd8(cur_time->tm_mday);
	ptr8[4] = to_bcd8(cur_time->tm_hour);
	ptr8[5] = to_bcd8(cur_time->tm_min);
	ptr8[6] = to_bcd8(cur_time->tm_sec);
	/* 02.42: coded as BCD encoded signed value in units of 15 minutes */
	tz15min = (cur_time->tm_gmtoff)/(60*15);
	ptr8[6] = to_bcd8(tz15min);
	if (tz15min < 0)
		ptr8[6] |= 0x80;
#endif

	return gsm48_sendmsg(msg);
}

static int gsm48_tx_mm_serv_ack(struct gsm_lchan *lchan)
{
	DEBUGP(DMM, "-> CM SERVICE ACK\n");
	return gsm48_tx_simple(lchan, GSM48_PDISC_MM, GSM48_MT_MM_CM_SERV_ACC);
}

/* 9.2.6 CM service reject */
static int gsm48_tx_mm_serv_rej(struct gsm_lchan *lchan,
				enum gsm48_reject_value value)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh;

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);

	msg->lchan = lchan;
	use_lchan(lchan);

	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_CM_SERV_REJ;
	gh->data[0] = value;
	DEBUGP(DMM, "-> CM SERVICE Reject cause: %d\n", value);

	return gsm48_sendmsg(msg);
}


/*
 * Handle CM Service Requests
 * a) Verify that the packet is long enough to contain the information
 *    we require otherwsie reject with INCORRECT_MESSAGE
 * b) Try to parse the TMSI. If we do not have one reject
 * c) Check that we know the subscriber with the TMSI otherwise reject
 *    with a HLR cause
 * d) Set the subscriber on the gsm_lchan and accept
 */
static int gsm48_rx_mm_serv_req(struct msgb *msg)
{
	u_int8_t mi_type;
	char mi_string[MI_SIZE];

	struct gsm_subscriber *subscr;
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm48_service_request *req =
			(struct gsm48_service_request *)gh->data;
	/* unfortunately in Phase1 the classmar2 length is variable */
	u_int8_t classmark2_len = gh->data[1];
	u_int8_t *classmark2 = gh->data+2;
	u_int8_t mi_len = *(classmark2 + classmark2_len);
	u_int8_t *mi = (classmark2 + classmark2_len + 1);

	DEBUGP(DMM, "<- CM SERVICE REQUEST ");
	if (msg->data_len < sizeof(struct gsm48_service_request*)) {
		DEBUGPC(DMM, "wrong sized message\n");
		return gsm48_tx_mm_serv_rej(msg->lchan,
					    GSM48_REJECT_INCORRECT_MESSAGE);
	}

	if (msg->data_len < req->mi_len + 6) {
		DEBUGPC(DMM, "does not fit in packet\n");
		return gsm48_tx_mm_serv_rej(msg->lchan,
					    GSM48_REJECT_INCORRECT_MESSAGE);
	}

	mi_type = mi[0] & GSM_MI_TYPE_MASK;
	if (mi_type != GSM_MI_TYPE_TMSI) {
		DEBUGPC(DMM, "mi_type is not TMSI: %d\n", mi_type);
		return gsm48_tx_mm_serv_rej(msg->lchan,
					    GSM48_REJECT_INCORRECT_MESSAGE);
	}

	mi_to_string(mi_string, sizeof(mi_string), mi, mi_len);
	subscr = subscr_get_by_tmsi(mi_string);
	DEBUGPC(DMM, "serv_type=0x%02x mi_type=0x%02x M(%s)\n",
		req->cm_service_type, mi_type, mi_string);

	/* FIXME: if we don't know the TMSI, inquire abit IMSI and allocate new TMSI */
	if (!subscr)
		return gsm48_tx_mm_serv_rej(msg->lchan,
					    GSM48_REJECT_IMSI_UNKNOWN_IN_HLR);

	if (!msg->lchan->subscr)
		msg->lchan->subscr = subscr;
	else if (msg->lchan->subscr != subscr) {
		DEBUGP(DMM, "<- CM Channel already owned by someone else?\n");
		subscr_put(subscr);
	}

	return gsm48_tx_mm_serv_ack(msg->lchan);
}

static int gsm48_rx_mm_imsi_detach_ind(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm48_imsi_detach_ind *idi =
				(struct gsm48_imsi_detach_ind *) gh->data;
	u_int8_t mi_type = idi->mi[0] & GSM_MI_TYPE_MASK;
	char mi_string[MI_SIZE];
	struct gsm_subscriber *subscr;

	mi_to_string(mi_string, sizeof(mi_string), idi->mi, idi->mi_len);
	DEBUGP(DMM, "IMSI DETACH INDICATION: mi_type=0x%02x MI(%s): ",
		mi_type, mi_string);

	switch (mi_type) {
	case GSM_MI_TYPE_TMSI:
		subscr = subscr_get_by_tmsi(mi_string);
		break;
	case GSM_MI_TYPE_IMSI:
		subscr = subscr_get_by_imsi(mi_string);
		break;
	case GSM_MI_TYPE_IMEI:
	case GSM_MI_TYPE_IMEISV:
		/* no sim card... FIXME: what to do ? */
		fprintf(stderr, "Unimplemented mobile identity type\n");
		break;
	default:	
		fprintf(stderr, "Unknown mobile identity type\n");
		break;
	}

	if (subscr) {
		subscr_update(subscr, msg->trx->bts,
				GSM_SUBSCRIBER_UPDATE_DETACHED);
		DEBUGP(DMM, "Subscriber: %s\n",
		       subscr->name ? subscr->name : subscr->imsi);
	} else
		DEBUGP(DMM, "Unknown Subscriber ?!?\n");

	put_lchan(msg->lchan);

	return 0;
}

/* Receive a GSM 04.08 Mobility Management (MM) message */
static int gsm0408_rcv_mm(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	int rc;

	switch (gh->msg_type & 0xbf) {
	case GSM48_MT_MM_LOC_UPD_REQUEST:
		DEBUGP(DMM, "LOCATION UPDATING REQUEST\n");
		rc = mm_rx_loc_upd_req(msg);
		break;
	case GSM48_MT_MM_ID_RESP:
		rc = mm_rx_id_resp(msg);
		break;
	case GSM48_MT_MM_CM_SERV_REQ:
		rc = gsm48_rx_mm_serv_req(msg);
		break;
	case GSM48_MT_MM_STATUS:
		DEBUGP(DMM, "STATUS: FIXME parse error cond.\n");
		break;
	case GSM48_MT_MM_TMSI_REALL_COMPL:
		DEBUGP(DMM, "TMSI Reallocation Completed. Subscriber: %s\n",
		       msg->lchan->subscr ?
				msg->lchan->subscr->imsi :
				"unknown subscriber");
		break;
	case GSM48_MT_MM_IMSI_DETACH_IND:
		rc = gsm48_rx_mm_imsi_detach_ind(msg);
		break;
	case GSM48_MT_MM_CM_REEST_REQ:
		DEBUGP(DMM, "CM REESTABLISH REQUEST: Not implemented\n");
		break;
	case GSM48_MT_MM_AUTH_RESP:
		DEBUGP(DMM, "AUTHENTICATION RESPONSE: Not implemented\n");
		break;
	default:
		fprintf(stderr, "Unknown GSM 04.08 MM msg type 0x%02x\n",
			gh->msg_type);
		break;
	}

	return rc;
}

/* Receive a PAGING RESPONSE message from the MS */
static int gsm48_rr_rx_pag_resp(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	u_int8_t *classmark2_lv = gh->data + 1;
	u_int8_t *mi_lv = gh->data + 2 + *classmark2_lv;
	u_int8_t mi_type = mi_lv[1] & GSM_MI_TYPE_MASK;
	char mi_string[MI_SIZE];
	struct gsm_subscriber *subscr;
	struct paging_signal_data sig_data;
	int rc = 0;

	mi_to_string(mi_string, sizeof(mi_string), mi_lv+1, *mi_lv);
	DEBUGP(DRR, "PAGING RESPONSE: mi_type=0x%02x MI(%s)\n",
		mi_type, mi_string);
	switch (mi_type) {
	case GSM_MI_TYPE_TMSI:
		subscr = subscr_get_by_tmsi(mi_string);
		break;
	case GSM_MI_TYPE_IMSI:
		subscr = subscr_get_by_imsi(mi_string);
		break;
	}

	if (!subscr) {
		DEBUGP(DRR, "<- Can't find any subscriber for this ID\n");
		/* FIXME: request id? close channel? */
		return -EINVAL;
	}
	DEBUGP(DRR, "<- Channel was requested by %s\n",
		subscr->name ? subscr->name : subscr->imsi);

	if (!msg->lchan->subscr)
		msg->lchan->subscr = subscr;
	else if (msg->lchan->subscr != subscr) {
		DEBUGP(DRR, "<- Channel already owned by someone else?\n");
		subscr_put(subscr);
	}

	sig_data.subscr = subscr;
	sig_data.bts	= msg->lchan->ts->trx->bts;
	sig_data.lchan	= msg->lchan;

	dispatch_signal(SS_PAGING, S_PAGING_COMPLETED, &sig_data);
	paging_request_stop(msg->trx->bts, subscr, msg->lchan);

	/* FIXME: somehow signal the completion of the PAGING to
	 * the entity that requested the paging */

	return rc;
}

static int gsm48_rx_rr_status(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);

	DEBUGP(DRR, "STATUS rr_cause = %s\n", 
		rr_cause_name(gh->data[0]));

	return 0;
}

/* Receive a GSM 04.08 Radio Resource (RR) message */
static int gsm0408_rcv_rr(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	int rc = 0;

	switch (gh->msg_type) {
	case GSM48_MT_RR_CLSM_CHG:
		DEBUGP(DRR, "CLASSMARK CHANGE\n");
		/* FIXME: what to do ?!? */
		break;
	case GSM48_MT_RR_GPRS_SUSP_REQ:
		DEBUGP(DRR, "GRPS SUSPEND REQUEST\n");
		break;
	case GSM48_MT_RR_PAG_RESP:
		rc = gsm48_rr_rx_pag_resp(msg);
		break;
	case GSM48_MT_RR_CHAN_MODE_MODIF_ACK:
		DEBUGP(DRR, "CHANNEL MODE MODIFY ACK\n");
		rc = rsl_chan_mode_modify_req(msg->lchan);
		break;
	case GSM48_MT_RR_STATUS:
		rc = gsm48_rx_rr_status(msg);
		break;
	default:
		fprintf(stderr, "Unimplemented GSM 04.08 RR msg type 0x%02x\n",
			gh->msg_type);
		break;
	}

	return rc;
}

/* 7.1.7 and 9.1.7 Channel release*/
int gsm48_send_rr_release(struct gsm_lchan *lchan)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
	u_int8_t *cause;

	msg->lchan = lchan;
	gh->proto_discr = GSM48_PDISC_RR;
	gh->msg_type = GSM48_MT_RR_CHAN_REL;

	cause = msgb_put(msg, 1);
	cause[0] = GSM48_RR_CAUSE_NORMAL;

	DEBUGP(DRR, "Sending Channel Release: Chan: Number: %d Type: %d\n",
		lchan->nr, lchan->type);

	return gsm48_sendmsg(msg);
}

/* Call Control */

/* The entire call control code is written in accordance with Figure 7.10c
 * for 'very early assignment', i.e. we allocate a TCH/F during IMMEDIATE
 * ASSIGN, then first use that TCH/F for signalling and later MODE MODIFY
 * it for voice */

static int gsm48_cc_tx_status(struct gsm_lchan *lchan)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
	u_int8_t *cause, *call_state;

	gh->proto_discr = GSM48_PDISC_CC;

	msg->lchan = lchan;

	gh->msg_type = GSM48_MT_CC_STATUS;

	cause = msgb_put(msg, 3);
	cause[0] = 2;
	cause[1] = GSM48_CAUSE_CS_GSM | GSM48_CAUSE_LOC_USER;
	cause[2] = 0x80 | 30;	/* response to status inquiry */

	call_state = msgb_put(msg, 1);
	call_state[0] = 0xc0 | 0x00;

	return gsm48_sendmsg(msg);
}

static int gsm48_tx_simple(struct gsm_lchan *lchan,
			   u_int8_t pdisc, u_int8_t msg_type)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));

	msg->lchan = lchan;

	gh->proto_discr = pdisc;
	gh->msg_type = msg_type;

	return gsm48_sendmsg(msg);
}

/* call-back from paging the B-end of the connection */
static int setup_trig_pag_evt(unsigned int hooknum, unsigned int event,
			      struct msgb *msg, void *_lchan, void *param)
{
	struct gsm_lchan *lchan = _lchan;
	struct gsm_call *remote_call = param;
	struct gsm_call *call = &lchan->call;
	int rc = 0;

	if (hooknum != GSM_HOOK_RR_PAGING)
		return -EINVAL;

	switch (event) {
	case GSM_PAGING_SUCCEEDED:
		DEBUGP(DCC, "paging succeeded!\n");
		remote_call->remote_lchan = lchan;
		call->remote_lchan = remote_call->local_lchan;
		/* send SETUP request to called party */
		rc = gsm48_cc_tx_setup(lchan, call->remote_lchan->subscr);
		if (is_ipaccess_bts(lchan->ts->trx->bts))
			rsl_ipacc_bind(lchan);
		break;
	case GSM_PAGING_EXPIRED:
		DEBUGP(DCC, "paging expired!\n");
		/* notify caller that we cannot reach called party */
		/* FIXME: correct cause, etc */
		rc = gsm48_tx_simple(remote_call->local_lchan, GSM48_PDISC_CC,
				     GSM48_MT_CC_RELEASE_COMPL);
		break;
	}
	return rc;
}

static int gsm48_cc_rx_status_enq(struct msgb *msg)
{
	DEBUGP(DCC, "-> STATUS ENQ\n");
	return gsm48_cc_tx_status(msg->lchan);
}

static int gsm48_cc_rx_setup(struct msgb *msg)
{
	struct gsm_call *call = &msg->lchan->call;
	struct gsm48_hdr *gh = msgb_l3(msg);
	unsigned int payload_len = msgb_l3len(msg) - sizeof(*gh);
	struct gsm_subscriber *called_subscr;
	char called_number[(43-2)*2 + 1] = "\0";
	struct tlv_parsed tp;
	u_int8_t num_type;
	int ret;

	if (call->state == GSM_CSTATE_NULL ||
	    call->state == GSM_CSTATE_RELEASE_REQ)
		use_lchan(msg->lchan);

	call->type = GSM_CT_MO;
	call->state = GSM_CSTATE_INITIATED;
	call->local_lchan = msg->lchan;
	call->transaction_id = gh->proto_discr & 0xf0;

	tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len);
	if (!TLVP_PRESENT(&tp, GSM48_IE_CALLED_BCD))
		goto err;

	/* Parse the number that was dialed and lookup subscriber */
	num_type = decode_bcd_number(called_number, sizeof(called_number),
				     TLVP_VAL(&tp, GSM48_IE_CALLED_BCD)-1);

	DEBUGP(DCC, "A -> SETUP(tid=0x%02x,number='%s')\n", call->transaction_id,
		called_number);

	called_subscr = subscr_get_by_extension(called_number);
	if (!called_subscr) {
		DEBUGP(DCC, "could not find subscriber, RELEASE\n");
		put_lchan(msg->lchan);
		return gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
				GSM48_MT_CC_RELEASE_COMPL);
	}
	if (called_subscr == msg->lchan->subscr) {
		DEBUGP(DCC, "subscriber calling himself ?!?\n");
		put_lchan(msg->lchan);
		subscr_put(called_subscr);
		return gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
				GSM48_MT_CC_RELEASE_COMPL);
	}

	subscr_get(msg->lchan->subscr);
	call->called_subscr = called_subscr;

	/* start paging of the receiving end of the call */
	paging_request(msg->trx->bts, called_subscr, RSL_CHANNEED_TCH_F,
			setup_trig_pag_evt, call);

	/* send a CALL PROCEEDING message to the MO */
	ret = gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
			       GSM48_MT_CC_CALL_PROC);

	if (is_ipaccess_bts(msg->trx->bts))
		rsl_ipacc_bind(msg->lchan);

	/* change TCH/F mode to voice */ 
	return gsm48_tx_chan_mode_modify(msg->lchan, GSM48_CMODE_SPEECH_EFR);

err:
	/* FIXME: send some kind of RELEASE */
	return 0;
}

static int gsm48_cc_rx_alerting(struct msgb *msg)
{
	struct gsm_call *call = &msg->lchan->call;

	DEBUGP(DCC, "A -> ALERTING\n");

	/* forward ALERTING to other party */
	if (!call->remote_lchan)
		return -EIO;

	DEBUGP(DCC, "B <- ALERTING\n");
	return gsm48_tx_simple(call->remote_lchan, GSM48_PDISC_CC,
			       GSM48_MT_CC_ALERTING);
}

/* map two ipaccess RTP streams onto each other */
static int tch_map(struct gsm_lchan *lchan, struct gsm_lchan *remote_lchan)
{
	struct gsm_bts *bts = lchan->ts->trx->bts;
	struct gsm_bts *remote_bts = remote_lchan->ts->trx->bts;
	struct gsm_bts_trx_ts *ts;

	DEBUGP(DCC, "Setting up TCH map between (bts=%u,trx=%u,ts=%u) and (bts=%u,trx=%u,ts=%u)\n",
		bts->nr, lchan->ts->trx->nr, lchan->ts->nr,
		remote_bts->nr, remote_lchan->ts->trx->nr, remote_lchan->ts->nr);

	if (bts->type != remote_bts->type) {
		DEBUGP(DCC, "Cannot switch calls between different BTS types yet\n");
		return -EINVAL;
	}
	
	switch (bts->type) {
	case GSM_BTS_TYPE_NANOBTS_900:
	case GSM_BTS_TYPE_NANOBTS_1800:
		ts = remote_lchan->ts;
		rsl_ipacc_connect(lchan, ts->abis_ip.bound_ip, ts->abis_ip.bound_port,
				  lchan->ts->abis_ip.attr_f8, ts->abis_ip.attr_fc);
	
		ts = lchan->ts;
		rsl_ipacc_connect(remote_lchan, ts->abis_ip.bound_ip, ts->abis_ip.bound_port,
				  remote_lchan->ts->abis_ip.attr_f8, ts->abis_ip.attr_fc);
		break;
	case GSM_BTS_TYPE_BS11:
		trau_mux_map_lchan(lchan, remote_lchan);
		break;
	default:
		DEBUGP(DCC, "Unknown BTS type %u\n", bts->type);
		break;
	}

	return 0;
}

static int gsm48_cc_rx_connect(struct msgb *msg)
{
	struct gsm_call *call = &msg->lchan->call;
	int rc;

	DEBUGP(DCC, "A -> CONNECT\n");
	
	rc = tch_map(msg->lchan, call->remote_lchan);
	if (rc)
		return -EIO;
		
	if (!call->remote_lchan)
		return -EIO;

	DEBUGP(DCC, "A <- CONNECT ACK\n");
	/* MT+MO: need to respond with CONNECT_ACK and pass on */
	rc = gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
			     GSM48_MT_CC_CONNECT_ACK);


	/* forward CONNECT to other party */
	DEBUGP(DCC, "B <- CONNECT\n");
	return gsm48_tx_simple(call->remote_lchan, GSM48_PDISC_CC,
			       GSM48_MT_CC_CONNECT);
}

static int gsm48_cc_rx_disconnect(struct msgb *msg)
{
	struct gsm_call *call = &msg->lchan->call;
	int rc;


	/* Section 5.4.3.2 */
	DEBUGP(DCC, "A -> DISCONNECT (state->RELEASE_REQ)\n");
	call->state = GSM_CSTATE_RELEASE_REQ;
	/* FIXME: clear the network connection */
	DEBUGP(DCC, "A <- RELEASE\n");
	rc = gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
			     GSM48_MT_CC_RELEASE);

	/*
	 * FIXME: This looks wrong! We should have a single
	 * place to do MMCC-REL-CNF/-REQ/-IND and then switch
	 * to the NULL state and relase the call
	 */
	subscr_put_channel(msg->lchan);

	/* forward DISCONNECT to other party */
	if (!call->remote_lchan)
		return -EIO;

	DEBUGP(DCC, "B <- DISCONNECT\n");
	return gsm48_tx_simple(call->remote_lchan, GSM48_PDISC_CC,
			       GSM48_MT_CC_DISCONNECT);
}

static const u_int8_t calling_bcd[] = { 0xb9, 0x32, 0x24 };

int gsm48_cc_tx_setup(struct gsm_lchan *lchan, 
		      struct gsm_subscriber *calling_subscr)
{
	struct msgb *msg = gsm48_msgb_alloc();
	struct gsm48_hdr *gh;
	struct gsm_call *call = &lchan->call;
	u_int8_t bcd_lv[19];

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));

	call->type = GSM_CT_MT;

	call->local_lchan = msg->lchan = lchan;
	use_lchan(lchan);

	gh->proto_discr = GSM48_PDISC_CC;
	gh->msg_type = GSM48_MT_CC_SETUP;

	msgb_tv_put(msg, GSM48_IE_SIGNAL, GSM48_SIGNAL_DIALTONE);
	if (calling_subscr) {
		encode_bcd_number(bcd_lv, sizeof(bcd_lv), 0xb9,
				  calling_subscr->extension);
		msgb_tlv_put(msg, GSM48_IE_CALLING_BCD,
			     bcd_lv[0], bcd_lv+1);
	}
	if (lchan->subscr) {
		encode_bcd_number(bcd_lv, sizeof(bcd_lv), 0xb9,
				  lchan->subscr->extension);
		msgb_tlv_put(msg, GSM48_IE_CALLED_BCD,
			     bcd_lv[0], bcd_lv+1);
	}

	DEBUGP(DCC, "B <- SETUP\n");

	return gsm48_sendmsg(msg);
}

static int gsm0408_rcv_cc(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	u_int8_t msg_type = gh->msg_type & 0xbf;
	struct gsm_call *call = &msg->lchan->call;
	int rc = 0;

	switch (msg_type) {
	case GSM48_MT_CC_CALL_CONF:
		/* Response to SETUP */
		DEBUGP(DCC, "-> CALL CONFIRM\n");
		/* we now need to MODIFY the channel */
		rc = gsm48_tx_chan_mode_modify(msg->lchan, GSM48_CMODE_SPEECH_EFR);
		break;
	case GSM48_MT_CC_RELEASE_COMPL:
		/* Answer from MS to RELEASE */
		DEBUGP(DCC, "-> RELEASE COMPLETE (state->NULL)\n");
		call->state = GSM_CSTATE_NULL;
		break;
	case GSM48_MT_CC_ALERTING:
		rc = gsm48_cc_rx_alerting(msg);
		break;
	case GSM48_MT_CC_CONNECT:
		rc = gsm48_cc_rx_connect(msg);
		break;
	case GSM48_MT_CC_CONNECT_ACK:
		/* MO: Answer to CONNECT */
		call->state = GSM_CSTATE_ACTIVE;
		DEBUGP(DCC, "-> CONNECT_ACK (state->ACTIVE)\n");
		break;
	case GSM48_MT_CC_RELEASE:
		DEBUGP(DCC, "-> RELEASE\n");
		DEBUGP(DCC, "<- RELEASE_COMPLETE\n");
		/* need to respond with RELEASE_COMPLETE */
		rc = gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
				     GSM48_MT_CC_RELEASE_COMPL);
		subscr_put_channel(msg->lchan);
                call->state = GSM_CSTATE_NULL;
		break;
	case GSM48_MT_CC_STATUS_ENQ:
		rc = gsm48_cc_rx_status_enq(msg);
		break;
	case GSM48_MT_CC_DISCONNECT:
		rc = gsm48_cc_rx_disconnect(msg);
		break;
	case GSM48_MT_CC_SETUP:
		/* MO: wants to establish a call */
		rc = gsm48_cc_rx_setup(msg);
		break;
	case GSM48_MT_CC_EMERG_SETUP:
		DEBUGP(DCC, "-> EMERGENCY SETUP\n");
		/* FIXME: continue with CALL_PROCEEDING, ALERTING, CONNECT, RELEASE_COMPLETE */
		break;
	case GSM48_MT_CC_HOLD:
		DEBUGP(DCC, "-> HOLD (rejecting)\n");
		rc = gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
				     GSM48_MT_CC_HOLD_REJ);
		break;
	case GSM48_MT_CC_RETR:
		DEBUGP(DCC, "-> RETR (rejecting)\n");
		rc = gsm48_tx_simple(msg->lchan, GSM48_PDISC_CC,
				     GSM48_MT_CC_RETR_REJ);
		break;
	default:
		fprintf(stderr, "Unimplemented GSM 04.08 CC msg type 0x%02x\n",
			msg_type);
		break;
	}

	return rc;
}

/* here we pass in a msgb from the RSL->RLL.  We expect the l3 pointer to be set */
int gsm0408_rcvmsg(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	u_int8_t pdisc = gh->proto_discr & 0x0f;
	int rc = 0;
	
	switch (pdisc) {
	case GSM48_PDISC_CC:
		rc = gsm0408_rcv_cc(msg);
		break;
	case GSM48_PDISC_MM:
		rc = gsm0408_rcv_mm(msg);
		break;
	case GSM48_PDISC_RR:
		rc = gsm0408_rcv_rr(msg);
		break;
	case GSM48_PDISC_SMS:
		rc = gsm0411_rcv_sms(msg);
		break;
	case GSM48_PDISC_MM_GPRS:
	case GSM48_PDISC_SM_GPRS:
		fprintf(stderr, "Unimplemented GSM 04.08 discriminator 0x%02d\n",
			pdisc);
		break;
	default:
		fprintf(stderr, "Unknown GSM 04.08 discriminator 0x%02d\n",
			pdisc);
		break;
	}

	return rc;
}

enum chreq_type {
	CHREQ_T_EMERG_CALL,
	CHREQ_T_CALL_REEST_TCH_F,
	CHREQ_T_CALL_REEST_TCH_H,
	CHREQ_T_CALL_REEST_TCH_H_DBL,
	CHREQ_T_SDCCH,
	CHREQ_T_TCH_F,
	CHREQ_T_VOICE_CALL_TCH_H,
	CHREQ_T_DATA_CALL_TCH_H,
	CHREQ_T_LOCATION_UPD,
	CHREQ_T_PAG_R_ANY,
	CHREQ_T_PAG_R_TCH_F,
	CHREQ_T_PAG_R_TCH_FH,
};

/* Section 9.1.8 / Table 9.9 */
struct chreq {
	u_int8_t val;
	u_int8_t mask;
	enum chreq_type type;
};

/* If SYSTEM INFORMATION TYPE 4 NECI bit == 1 */
static const struct chreq chreq_type_neci1[] = {
	{ 0xa0, 0xe0, CHREQ_T_EMERG_CALL },
	{ 0xc0, 0xe0, CHREQ_T_CALL_REEST_TCH_F },
	{ 0x68, 0xfc, CHREQ_T_CALL_REEST_TCH_H },
	{ 0x6c, 0xfc, CHREQ_T_CALL_REEST_TCH_H_DBL },
	{ 0xe0, 0xe0, CHREQ_T_SDCCH },
	{ 0x40, 0xf0, CHREQ_T_VOICE_CALL_TCH_H },
	{ 0x50, 0xf0, CHREQ_T_DATA_CALL_TCH_H },
	{ 0x00, 0xf0, CHREQ_T_LOCATION_UPD },
	{ 0x10, 0xf0, CHREQ_T_SDCCH },
	{ 0x80, 0xe0, CHREQ_T_PAG_R_ANY },
	{ 0x20, 0xf0, CHREQ_T_PAG_R_TCH_F },
	{ 0x30, 0xf0, CHREQ_T_PAG_R_TCH_FH },
};

/* If SYSTEM INFORMATION TYPE 4 NECI bit == 0 */
static const struct chreq chreq_type_neci0[] = {
	{ 0xa0, 0xe0, CHREQ_T_EMERG_CALL },
	{ 0xc0, 0xe0, CHREQ_T_CALL_REEST_TCH_H },
	{ 0xe0, 0xe0, CHREQ_T_TCH_F },
	{ 0x50, 0xf0, CHREQ_T_DATA_CALL_TCH_H },
	{ 0x00, 0xe0, CHREQ_T_LOCATION_UPD },
	{ 0x80, 0xe0, CHREQ_T_PAG_R_ANY },
	{ 0x20, 0xf0, CHREQ_T_PAG_R_TCH_F },
	{ 0x30, 0xf0, CHREQ_T_PAG_R_TCH_FH },
};

static const enum gsm_chan_t ctype_by_chreq[] = {
	[CHREQ_T_EMERG_CALL]		= GSM_LCHAN_TCH_F,
	[CHREQ_T_CALL_REEST_TCH_F]	= GSM_LCHAN_TCH_F,
	[CHREQ_T_CALL_REEST_TCH_H]	= GSM_LCHAN_TCH_H,
	[CHREQ_T_CALL_REEST_TCH_H_DBL]	= GSM_LCHAN_TCH_H,
	[CHREQ_T_SDCCH]			= GSM_LCHAN_SDCCH,
	[CHREQ_T_TCH_F]			= GSM_LCHAN_TCH_F,
	[CHREQ_T_VOICE_CALL_TCH_H]	= GSM_LCHAN_TCH_H,
	[CHREQ_T_DATA_CALL_TCH_H]	= GSM_LCHAN_TCH_H,
	[CHREQ_T_LOCATION_UPD]		= GSM_LCHAN_SDCCH,
	[CHREQ_T_PAG_R_ANY]		= GSM_LCHAN_SDCCH,
	[CHREQ_T_PAG_R_TCH_F]		= GSM_LCHAN_TCH_F,
	[CHREQ_T_PAG_R_TCH_FH]		= GSM_LCHAN_TCH_F,
};

static const enum gsm_chreq_reason_t reason_by_chreq[] = {
	[CHREQ_T_EMERG_CALL]		= GSM_CHREQ_REASON_EMERG,
	[CHREQ_T_CALL_REEST_TCH_F]	= GSM_CHREQ_REASON_CALL,
	[CHREQ_T_CALL_REEST_TCH_H]	= GSM_CHREQ_REASON_CALL,
	[CHREQ_T_CALL_REEST_TCH_H_DBL]	= GSM_CHREQ_REASON_CALL,
	[CHREQ_T_SDCCH]			= GSM_CHREQ_REASON_OTHER,
	[CHREQ_T_TCH_F]			= GSM_CHREQ_REASON_OTHER,
	[CHREQ_T_VOICE_CALL_TCH_H]	= GSM_CHREQ_REASON_OTHER,
	[CHREQ_T_DATA_CALL_TCH_H]	= GSM_CHREQ_REASON_OTHER,
	[CHREQ_T_LOCATION_UPD]		= GSM_CHREQ_REASON_LOCATION_UPD,
	[CHREQ_T_PAG_R_ANY]		= GSM_CHREQ_REASON_PAG,
	[CHREQ_T_PAG_R_TCH_F]		= GSM_CHREQ_REASON_PAG,
	[CHREQ_T_PAG_R_TCH_FH]		= GSM_CHREQ_REASON_PAG,
};

enum gsm_chan_t get_ctype_by_chreq(struct gsm_bts *bts, u_int8_t ra)
{
	int i;
	/* FIXME: determine if we set NECI = 0 in the BTS SI4 */

	for (i = 0; i < ARRAY_SIZE(chreq_type_neci0); i++) {
		const struct chreq *chr = &chreq_type_neci0[i];
		if ((ra & chr->mask) == chr->val)
			return ctype_by_chreq[chr->type];
	}
	fprintf(stderr, "Unknown CHANNEL REQUEST RQD 0x%02x\n", ra);
	return GSM_LCHAN_SDCCH;
}

enum gsm_chreq_reason_t get_reason_by_chreq(struct gsm_bts *bts, u_int8_t ra)
{
	int i;
	/* FIXME: determine if we set NECI = 0 in the BTS SI4 */

	for (i = 0; i < ARRAY_SIZE(chreq_type_neci0); i++) {
		const struct chreq *chr = &chreq_type_neci0[i];
		if ((ra & chr->mask) == chr->val)
			return reason_by_chreq[chr->type];
	}
	fprintf(stderr, "Unknown CHANNEL REQUEST REASON 0x%02x\n", ra);
	return GSM_CHREQ_REASON_OTHER;
}