aboutsummaryrefslogtreecommitdiffstats
path: root/src/libmsc/gsm_04_08.c
blob: 09744db69c998139f51441bd5db14de83df62fa4 (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
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
/* 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) 2008-2016 by Harald Welte <laforge@gnumonks.org>
 * (C) 2008-2012 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 <stdbool.h>
#include <errno.h>
#include <time.h>
#include <netinet/in.h>
#include <regex.h>
#include <sys/types.h>

#include "bscconfig.h"

#include <osmocom/msc/db.h>
#include <osmocom/msc/debug.h>
#include <osmocom/msc/gsm_data.h>
#include <osmocom/msc/gsm_subscriber.h>
#include <osmocom/msc/gsm_04_11.h>
#include <osmocom/msc/gsm_04_08.h>
#include <osmocom/msc/gsm_04_80.h>
#include <osmocom/msc/gsm_04_14.h>
#include <osmocom/msc/gsm_09_11.h>
#include <osmocom/msc/signal.h>
#include <osmocom/msc/transaction.h>
#include <osmocom/msc/silent_call.h>
#include <osmocom/msc/mncc_int.h>
#include <osmocom/abis/e1_input.h>
#include <osmocom/core/bitvec.h>
#include <osmocom/msc/vlr.h>
#include <osmocom/msc/msc_ifaces.h>

#include <osmocom/gsm/gsm48.h>
#include <osmocom/gsm/gsm0480.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/gsm/protocol/gsm_04_08.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/byteswap.h>
#include <osmocom/gsm/tlv.h>
#include <osmocom/crypt/auth.h>
#ifdef BUILD_IU
#include <osmocom/ranap/iu_client.h>
#endif

#include <osmocom/msc/msc_ifaces.h>
#include <osmocom/msc/a_iface.h>
#include <osmocom/msc/msc_mgcp.h>

#include <assert.h>


void *tall_locop_ctx;
void *tall_authciphop_ctx;

static int gsm0408_loc_upd_acc(struct ran_conn *conn,
			       uint32_t send_tmsi);

/*! Send a simple GSM 04.08 message without any payload
 * \param      conn      Active RAN connection
 * \param[in]  pdisc     Protocol discriminator
 * \param[in]  msg_type  Message type
 * \return     result of \ref gsm48_conn_sendmsg
 */
int gsm48_tx_simple(struct ran_conn *conn,
		    uint8_t pdisc, uint8_t msg_type)
{
	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 TX SIMPLE");
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));

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

	return gsm48_conn_sendmsg(msg, conn, NULL);
}

static bool classmark1_is_r99(const struct gsm48_classmark1 *cm1)
{
	return cm1->rev_lev >= 2;
}

static bool classmark2_is_r99(const uint8_t *cm2, uint8_t cm2_len)
{
	uint8_t rev_lev;
	if (!cm2_len)
		return false;
	rev_lev = (cm2[0] >> 5) & 0x3;
	return rev_lev >= 2;
}

static bool classmark_is_r99(struct gsm_classmark *cm)
{
	if (cm->classmark1_set)
		return classmark1_is_r99(&cm->classmark1);
	return classmark2_is_r99(cm->classmark2, cm->classmark2_len);
}

static const char *classmark_a5_name(const struct gsm_classmark *cm)
{
	static char buf[128];
	char cm1[42];
	char cm2[42];
	char cm3[42];

	if (cm->classmark1_set)
		snprintf(cm1, sizeof(cm1), "cm1{a5/1=%s}",
		     cm->classmark1.a5_1 ? "not-supported":"supported" /* inverted logic */);
	else
		snprintf(cm1, sizeof(cm1), "no-cm1");

	if (cm->classmark2_len >= 3)
		snprintf(cm2, sizeof(cm2), " cm2{0x%x=%s%s}",
			 cm->classmark2[2],
			 cm->classmark2[2] & 0x1 ? " A5/2" : "",
			 cm->classmark2[2] & 0x2 ? " A5/3" : "");
	else
		snprintf(cm2, sizeof(cm2), " no-cm2");

	if (cm->classmark3_len >= 1)
		snprintf(cm3, sizeof(cm3), " cm3{0x%x=%s%s%s%s}",
			 cm->classmark3[0],
			 cm->classmark3[0] & (1 << 0) ? " A5/4" : "",
			 cm->classmark3[0] & (1 << 1) ? " A5/5" : "",
			 cm->classmark3[0] & (1 << 2) ? " A5/6" : "",
			 cm->classmark3[0] & (1 << 3) ? " A5/7" : "");
	else
		snprintf(cm3, sizeof(cm3), " no-cm3");

	snprintf(buf, sizeof(buf), "%s%s%s", cm1, cm2, cm3);
	return buf;
}

/* Determine if the given CLASSMARK (1/2/3) value permits a given A5/n cipher.
 * Return 1 when the given A5/n is permitted, 0 when not, and negative if the respective MS CLASSMARK is
 * not known, where the negative number indicates the classmark type: -2 means Classmark 2 is not
 * available. */
static int classmark_supports_a5(const struct gsm_classmark *cm, uint8_t a5)
{
	switch (a5) {
	case 0:
		/* all phones must implement A5/0, see 3GPP TS 43.020 4.9 */
		return 1;
	case 1:
		/* 3GPP TS 43.020 4.9 requires A5/1 to be suppored by all phones and actually states:
		 * "The network shall not provide service to an MS which indicates that it does not
		 *  support the ciphering algorithm A5/1.".  However, let's be more tolerant based
		 * on policy here */
		/* See 3GPP TS 24.008 10.5.1.7 */
		if (!cm->classmark1_set) {
			DEBUGP(DMSC, "CLASSMARK 1 unknown, assuming MS supports A5/1\n");
			return -1;
		} else {
			if (cm->classmark1.a5_1)
				return 0;	/* Inverted logic for this bit! */
			else
				return 1;
		}
		break;
	case 2:
	case 3:
		/* See 3GPP TS 24.008 10.5.1.6 */
		if (cm->classmark2_len < 3) {
			return -2;
		} else {
			if (cm->classmark2[2] & (1 << (a5-2)))
				return 1;
			else
				return 0;
		}
		break;
	case 4:
	case 5:
	case 6:
	case 7:
		/* See 3GPP TS 24.008 10.5.1.7 */
		if (cm->classmark3_len < 1) {
			return -3;
		} else {
			if (cm->classmark3[0] & (1 << (a5-4)))
				return 1;
			else
				return 0;
		}
		break;
	default:
		return false;
	}
}

int gsm48_conn_sendmsg(struct msgb *msg, struct ran_conn *conn, struct gsm_trans *trans)
{
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msg->data;

	/* if we get passed a transaction reference, do some common
	 * work that the caller no longer has to do */
	if (trans) {
		gh->proto_discr = trans->protocol | (trans->transaction_id << 4);
		OMSC_LINKID_CB(msg) = trans->dlci;
	}

	return msc_tx_dtap(conn, msg);
}

/* clear all transactions globally; used in case of MNCC socket disconnect */
void gsm0408_clear_all_trans(struct gsm_network *net, int protocol)
{
	struct gsm_trans *trans, *temp;

	LOGP(DCC, LOGL_NOTICE, "Clearing all currently active transactions!!!\n");

	llist_for_each_entry_safe(trans, temp, &net->trans_list, entry) {
		if (trans->protocol == protocol) {
			trans->callref = 0;
			trans_free(trans);
		}
	}
}

/* Chapter 9.2.14 : Send LOCATION UPDATING REJECT */
static int gsm0408_loc_upd_rej(struct ran_conn *conn, uint8_t cause)
{
	struct msgb *msg;

	msg = gsm48_create_loc_upd_rej(cause);
	if (!msg) {
		LOGP(DMM, LOGL_ERROR, "Failed to create msg for LOCATION UPDATING REJECT.\n");
		return -1;
	}

	LOGP(DMM, LOGL_INFO, "Subscriber %s: LOCATION UPDATING REJECT\n",
	     vlr_subscr_name(conn->vsub));

	return gsm48_conn_sendmsg(msg, conn, NULL);
}

/* Chapter 9.2.13 : Send LOCATION UPDATE ACCEPT */
static int gsm0408_loc_upd_acc(struct ran_conn *conn,
			       uint32_t send_tmsi)
{
	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 LOC UPD ACC");
	struct gsm48_hdr *gh;
	struct gsm48_loc_area_id *lai;
	uint8_t *mid;
	struct osmo_location_area_id laid = {
		.plmn = conn->network->plmn,
		.lac = conn->lac,
	};

	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));
	gsm48_generate_lai2(lai, &laid);

	if (send_tmsi == GSM_RESERVED_TMSI) {
		/* we did not allocate a TMSI to the MS, so we need to
		 * include the IMSI in order for the MS to delete any
		 * old TMSI that might still be allocated */
		uint8_t mi[10];
		int len;
		len = gsm48_generate_mid_from_imsi(mi, conn->vsub->imsi);
		mid = msgb_put(msg, len);
		memcpy(mid, mi, len);
		DEBUGP(DMM, "-> %s LOCATION UPDATE ACCEPT\n",
		       vlr_subscr_name(conn->vsub));
	} else {
		/* Include the TMSI, which means that the MS will send a
		 * TMSI REALLOCATION COMPLETE, and we should wait for
		 * that until T3250 expiration */
		mid = msgb_put(msg, GSM48_MID_TMSI_LEN);
		gsm48_generate_mid_from_tmsi(mid, send_tmsi);
		DEBUGP(DMM, "-> %s LOCATION UPDATE ACCEPT (TMSI = 0x%08x)\n",
		       vlr_subscr_name(conn->vsub),
		       send_tmsi);
	}
	/* TODO: Follow-on proceed */
	/* TODO: CTS permission */
	/* TODO: Equivalent PLMNs */
	/* TODO: Emergency Number List */
	/* TODO: Per-MS T3312 */


	return gsm48_conn_sendmsg(msg, conn, NULL);
}

/* Transmit Chapter 9.2.10 Identity Request */
static int mm_tx_identity_req(struct ran_conn *conn, uint8_t id_type)
{
	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 ID REQ");
	struct gsm48_hdr *gh;

	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_conn_sendmsg(msg, conn, NULL);
}

/* Parse Chapter 9.2.11 Identity Response */
static int mm_rx_id_resp(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	uint8_t *mi = gh->data+1;
	uint8_t mi_len = gh->data[0];

	if (!conn->vsub) {
		LOGP(DMM, LOGL_ERROR,
		     "Rx MM Identity Response: invalid: no subscriber\n");
		return -EINVAL;
	}

	DEBUGP(DMM, "IDENTITY RESPONSE: MI=%s\n", osmo_mi_name(mi, mi_len));

	osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_IDENTITY, gh->data);

	return vlr_subscr_rx_id_resp(conn->vsub, mi, mi_len);
}

/* Chapter 9.2.15: Receive Location Updating Request.
 * Keep this function non-static for direct invocation by unit tests. */
int mm_rx_loc_upd_req(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm_network *net = conn->network;
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm48_loc_upd_req *lu;
	uint8_t mi_type;
	char mi_string[GSM48_MI_SIZE];
	enum vlr_lu_type vlr_lu_type = VLR_LU_TYPE_REGULAR;
	uint32_t tmsi;
	char *imsi;
	struct osmo_location_area_id old_lai, new_lai;
	struct osmo_fsm_inst *lu_fsm;
	bool is_utran;

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

	if (ran_conn_is_establishing_auth_ciph(conn)) {
		LOG_RAN_CONN_CAT(conn, DMM, LOGL_ERROR,
				 "Cannot accept another LU, conn already busy establishing authenticity;"
				 " extraneous LOCATION UPDATING REQUEST: MI=%s LU-type=%s\n",
				 osmo_mi_name(lu->mi, lu->mi_len), osmo_lu_type_name(lu->type));
		return -EINVAL;
	}

	if (ran_conn_is_accepted(conn)) {
		LOG_RAN_CONN_CAT(conn, DMM, LOGL_ERROR,
				 "Cannot accept another LU, conn already established;"
				 " extraneous LOCATION UPDATING REQUEST: MI=%s LU-type=%s\n",
				 osmo_mi_name(lu->mi, lu->mi_len), osmo_lu_type_name(lu->type));
		return -EINVAL;
	}

	conn->complete_layer3_type = COMPLETE_LAYER3_LU;
	ran_conn_update_id_from_mi(conn, lu->mi, lu->mi_len);

	LOG_RAN_CONN_CAT(conn, DMM, LOGL_DEBUG, "LOCATION UPDATING REQUEST: MI=%s LU-type=%s\n",
			 osmo_mi_name(lu->mi, lu->mi_len), osmo_lu_type_name(lu->type));

	osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_IDENTITY, &lu->mi_len);

	switch (lu->type) {
	case GSM48_LUPD_NORMAL:
		rate_ctr_inc(&conn->network->msc_ctrs->ctr[MSC_CTR_LOC_UPDATE_TYPE_NORMAL]);
		vlr_lu_type = VLR_LU_TYPE_REGULAR;
		break;
	case GSM48_LUPD_IMSI_ATT:
		rate_ctr_inc(&conn->network->msc_ctrs->ctr[MSC_CTR_LOC_UPDATE_TYPE_ATTACH]);
		vlr_lu_type = VLR_LU_TYPE_IMSI_ATTACH;
		break;
	case GSM48_LUPD_PERIODIC:
		rate_ctr_inc(&conn->network->msc_ctrs->ctr[MSC_CTR_LOC_UPDATE_TYPE_PERIODIC]);
		vlr_lu_type = VLR_LU_TYPE_PERIODIC;
		break;
	}

	/* TODO: 10.5.1.6 MS Classmark for UMTS / Classmark 2 */
	/* TODO: 10.5.3.14 Aditional update parameters (CS fallback calls) */
	/* TODO: 10.5.7.8 Device properties */
	/* TODO: 10.5.1.15 MS network feature support */

	mi_type = lu->mi[0] & GSM_MI_TYPE_MASK;
	gsm48_mi_to_string(mi_string, sizeof(mi_string), lu->mi, lu->mi_len);
	switch (mi_type) {
	case GSM_MI_TYPE_IMSI:
		tmsi = GSM_RESERVED_TMSI;
		imsi = mi_string;
		break;
	case GSM_MI_TYPE_TMSI:
		tmsi = tmsi_from_string(mi_string);
		imsi = NULL;
		break;
	default:
		LOG_RAN_CONN_CAT(conn, DMM, LOGL_ERROR, "unknown mobile identity type\n");
		tmsi = GSM_RESERVED_TMSI;
		imsi = NULL;
		break;
	}

	gsm48_decode_lai2(&lu->lai, &old_lai);
	new_lai.plmn = conn->network->plmn;
	new_lai.lac = conn->lac;
	LOG_RAN_CONN_CAT(conn, DMM, LOGL_DEBUG, "LU/new-LAC: %u/%u\n", old_lai.lac, new_lai.lac);

	is_utran = (conn->via_ran == OSMO_RAT_UTRAN_IU);
	lu_fsm = vlr_loc_update(conn->fi,
				RAN_CONN_E_ACCEPTED, RAN_CONN_E_CN_CLOSE, NULL,
				net->vlr, conn, vlr_lu_type, tmsi, imsi,
				&old_lai, &new_lai,
				is_utran || conn->network->authentication_required,
				is_utran || conn->network->a5_encryption_mask > 0x01,
				lu->key_seq,
				classmark1_is_r99(&lu->classmark1),
				is_utran,
				net->vlr->cfg.assign_tmsi);
	if (!lu_fsm) {
		LOG_RAN_CONN(conn, LOGL_ERROR, "Can't start LU FSM\n");
		return 0;
	}

	/* From vlr_loc_update() we expect an implicit dispatch of
	 * VLR_ULA_E_UPDATE_LA, and thus we expect msc_vlr_subscr_assoc() to
	 * already have been called and completed. Has an error occured? */

	if (!conn->vsub || conn->vsub->lu_fsm != lu_fsm) {
		LOG_RAN_CONN(conn, LOGL_ERROR, "internal error during Location Updating attempt\n");
		return -EIO;
	}

	conn->vsub->classmark.classmark1 = lu->classmark1;
	conn->vsub->classmark.classmark1_set = true;

	ran_conn_complete_layer_3(conn);
	return 0;
}

/* Turn int into semi-octet representation: 98 => 0x89 */
/* FIXME: libosmocore/libosmogsm */
static uint8_t bcdify(uint8_t value)
{
        uint8_t ret;

        ret = value / 10;
        ret |= (value % 10) << 4;

        return ret;
}

/* Generate a message buffer that contains a valid MM info message,
 * See also 3GPP TS 24.008, chapter 9.2.15a */
struct msgb *gsm48_create_mm_info(struct gsm_network *net)
{
	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 MM INF");
	struct gsm48_hdr *gh;
	uint8_t *ptr8;
	int name_len, name_pad;

	time_t cur_t;
	struct tm* gmt_time;
	struct tm* local_time;
	int tzunits;
	int dst = 0;

	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) {
#if 0
		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 = (uint16_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 */
#endif
		name_len = (strlen(net->name_long)*7)/8;
		name_pad = (8 - strlen(net->name_long)*7)%8;
		if (name_pad > 0)
			name_len++;
		/* 10.5.3.5a */
		ptr8 = msgb_put(msg, 3);
		ptr8[0] = GSM48_IE_NAME_LONG;
		ptr8[1] = name_len +1;
		ptr8[2] = 0x80 | name_pad; /* Cell Broadcast DCS, no CI */

		ptr8 = msgb_put(msg, name_len);
		gsm_7bit_encode_n(ptr8, name_len, net->name_long, NULL);

	}

	if (net->name_short) {
#if 0
		name_len = strlen(net->name_short);
		/* 10.5.3.5a */
		ptr8 = (uint8_t *) msgb_put(msg, 3);
		ptr8[0] = GSM48_IE_NAME_SHORT;
		ptr8[1] = name_len*2 + 1;
		ptr8[2] = 0x90; /* UCS2, no spare bits, no CI */

		ptr16 = (uint16_t *) msgb_put(msg, name_len*2);
		for (i = 0; i < name_len; i++)
			ptr16[i] = htons(net->name_short[i]);
#endif
		name_len = (strlen(net->name_short)*7)/8;
		name_pad = (8 - strlen(net->name_short)*7)%8;
		if (name_pad > 0)
			name_len++;
		/* 10.5.3.5a */
		ptr8 = (uint8_t *) msgb_put(msg, 3);
		ptr8[0] = GSM48_IE_NAME_SHORT;
		ptr8[1] = name_len +1;
		ptr8[2] = 0x80 | name_pad; /* Cell Broadcast DCS, no CI */

		ptr8 = msgb_put(msg, name_len);
		gsm_7bit_encode_n(ptr8, name_len, net->name_short, NULL);

	}

	/* Section 10.5.3.9 */
	cur_t = time(NULL);
	gmt_time = gmtime(&cur_t);

	ptr8 = msgb_put(msg, 8);
	ptr8[0] = GSM48_IE_NET_TIME_TZ;
	ptr8[1] = bcdify(gmt_time->tm_year % 100);
	ptr8[2] = bcdify(gmt_time->tm_mon + 1);
	ptr8[3] = bcdify(gmt_time->tm_mday);
	ptr8[4] = bcdify(gmt_time->tm_hour);
	ptr8[5] = bcdify(gmt_time->tm_min);
	ptr8[6] = bcdify(gmt_time->tm_sec);

	if (net->tz.override) {
		/* Convert tz.hr and tz.mn to units */
		if (net->tz.hr < 0) {
			tzunits = ((net->tz.hr/-1)*4);
			tzunits = tzunits + (net->tz.mn/15);
			ptr8[7] = bcdify(tzunits);
			/* Set negative time */
			ptr8[7] |= 0x08;
		}
		else {
			tzunits = net->tz.hr*4;
			tzunits = tzunits + (net->tz.mn/15);
			ptr8[7] = bcdify(tzunits);
		}
		/* Convert DST value */
		if (net->tz.dst >= 0 && net->tz.dst <= 2)
			dst = net->tz.dst;
	}
	else {
		/* Need to get GSM offset and convert into 15 min units */
		/* This probably breaks if gmtoff returns a value not evenly divisible by 15? */
#ifdef HAVE_TM_GMTOFF_IN_TM
		local_time = localtime(&cur_t);
		tzunits = (local_time->tm_gmtoff/60)/15;
#else
		/* find timezone offset */
		time_t utc;
		double offsetFromUTC;
		utc = mktime(gmt_time);
		local_time = localtime(&cur_t);
		offsetFromUTC = difftime(cur_t, utc);
		if (local_time->tm_isdst)
			offsetFromUTC += 3600.0;
		tzunits = ((int)offsetFromUTC) / 60 / 15;
#endif
		if (tzunits < 0) {
			tzunits = tzunits/-1;
			ptr8[7] = bcdify(tzunits);
			/* Flip it to negative */
			ptr8[7] |= 0x08;
		}
		else
			ptr8[7] = bcdify(tzunits);

		/* Does not support DST +2 */
		if (local_time->tm_isdst)
			dst = 1;
	}

	if (dst) {
		ptr8 = msgb_put(msg, 3);
		ptr8[0] = GSM48_IE_NET_DST;
		ptr8[1] = 1;
		ptr8[2] = dst;
	}

	return msg;
}

/* Section 9.2.15a */
int gsm48_tx_mm_info(struct ran_conn *conn)
{
	struct gsm_network *net = conn->network;
	struct msgb *msg;

        msg = gsm48_create_mm_info(net);

	LOG_RAN_CONN(conn, LOGL_DEBUG, "Tx MM INFO\n");
	return gsm48_conn_sendmsg(msg, conn, NULL);
}

/*! Send an Authentication Request to MS on the given RAN connection
 * according to 3GPP/ETSI TS 24.008, Section 9.2.2.
 * \param[in] conn  Subscriber connection to send on.
 * \param[in] rand  Random challenge token to send, must be 16 bytes long.
 * \param[in] autn  r99: In case of UMTS mutual authentication, AUTN token to
 * 	send; must be 16 bytes long, or pass NULL for plain GSM auth.
 * \param[in] key_seq  auth tuple's sequence number.
 */
int gsm48_tx_mm_auth_req(struct ran_conn *conn, uint8_t *rand,
			 uint8_t *autn, int key_seq)
{
	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 AUTH REQ");
	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
	struct gsm48_auth_req *ar = (struct gsm48_auth_req *) msgb_put(msg, sizeof(*ar));

	DEBUGP(DMM, "Tx AUTH REQ (rand = %s)\n", osmo_hexdump_nospc(rand, 16));
	if (autn)
		DEBUGP(DMM, "   AUTH REQ (autn = %s)\n", osmo_hexdump_nospc(autn, 16));

	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_AUTH_REQ;

	ar->key_seq = key_seq;

	/* 16 bytes RAND parameters */
	osmo_static_assert(sizeof(ar->rand) == 16, sizeof_auth_req_r99_rand);
	if (rand)
		memcpy(ar->rand, rand, 16);


	/* 16 bytes AUTN */
	if (autn)
		msgb_tlv_put(msg, GSM48_IE_AUTN, 16, autn);

	return gsm48_conn_sendmsg(msg, conn, NULL);
}

/* Section 9.2.1 */
int gsm48_tx_mm_auth_rej(struct ran_conn *conn)
{
	DEBUGP(DMM, "-> AUTH REJECT\n");
	return gsm48_tx_simple(conn, GSM48_PDISC_MM, GSM48_MT_MM_AUTH_REJ);
}

static int msc_vlr_tx_cm_serv_acc(void *msc_conn_ref);
static int msc_vlr_tx_cm_serv_rej(void *msc_conn_ref, enum gsm48_reject_value result);

static int cm_serv_reuse_conn(struct ran_conn *conn, const uint8_t *mi_lv)
{
	uint8_t mi_type;
	char mi_string[GSM48_MI_SIZE];
	uint32_t tmsi;

	gsm48_mi_to_string(mi_string, sizeof(mi_string), mi_lv+1, mi_lv[0]);
	mi_type = mi_lv[1] & GSM_MI_TYPE_MASK;

	switch (mi_type) {
	case GSM_MI_TYPE_IMSI:
		if (vlr_subscr_matches_imsi(conn->vsub, mi_string))
			goto accept_reuse;
		break;
	case GSM_MI_TYPE_TMSI:
		tmsi = osmo_load32be(mi_lv+2);
		if (vlr_subscr_matches_tmsi(conn->vsub, tmsi))
			goto accept_reuse;
		break;
	case GSM_MI_TYPE_IMEI:
		if (vlr_subscr_matches_imei(conn->vsub, mi_string))
			goto accept_reuse;
		break;
	default:
		break;
	}

	LOGP(DMM, LOGL_ERROR, "%s: CM Service Request with mismatching mobile identity: %s %s\n",
	     vlr_subscr_name(conn->vsub), gsm48_mi_type_name(mi_type), mi_string);
	msc_vlr_tx_cm_serv_rej(conn, GSM48_REJECT_ILLEGAL_MS);
	return -EINVAL;

accept_reuse:
	DEBUGP(DMM, "%s: re-using already accepted connection\n",
	       vlr_subscr_name(conn->vsub));

	if (!conn->received_cm_service_request) {
		conn->received_cm_service_request = true;
		ran_conn_get(conn, RAN_CONN_USE_CM_SERVICE);
	}
	ran_conn_update_id(conn);
	return conn->network->vlr->ops.tx_cm_serv_acc(conn);
}

/*
 * 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 conn and accept
 *
 * Keep this function non-static for direct invocation by unit tests.
 */
int gsm48_rx_mm_serv_req(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm_network *net = conn->network;
	uint8_t mi_type;
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm48_service_request *req =
			(struct gsm48_service_request *)gh->data;
	/* unfortunately in Phase1 the classmark2 length is variable */
	uint8_t classmark2_len = gh->data[1];
	uint8_t *classmark2 = gh->data+2;
	uint8_t *mi_p = classmark2 + classmark2_len;
	uint8_t mi_len = *mi_p;
	uint8_t *mi = mi_p + 1;
	struct osmo_location_area_id lai;
	bool is_utran;

	lai.plmn = conn->network->plmn;
	lai.lac = conn->lac;

	if (msg->data_len < sizeof(struct gsm48_service_request*)) {
		LOG_RAN_CONN(conn, LOGL_ERROR, "Rx CM SERVICE REQUEST: wrong message size (%u < %zu)\n",
			     msg->data_len, sizeof(struct gsm48_service_request*));
		return msc_gsm48_tx_mm_serv_rej(conn,
						GSM48_REJECT_INCORRECT_MESSAGE);
	}

	if (msg->data_len < req->mi_len + 6) {
		LOG_RAN_CONN(conn, LOGL_ERROR, "Rx CM SERVICE REQUEST: message does not fit in packet\n");
		return msc_gsm48_tx_mm_serv_rej(conn,
						GSM48_REJECT_INCORRECT_MESSAGE);
	}

	if (ran_conn_is_establishing_auth_ciph(conn)) {
		LOG_RAN_CONN(conn, LOGL_ERROR,
		     "Cannot accept CM Service Request, conn already busy establishing authenticity\n");
		msc_vlr_tx_cm_serv_rej(conn, GSM48_REJECT_CONGESTION);
		return -EINVAL;
		/* or should we accept and note down the service request anyway? */
	}

	conn->complete_layer3_type = COMPLETE_LAYER3_CM_SERVICE_REQ;
	ran_conn_update_id_from_mi(conn, mi, mi_len);
	LOG_RAN_CONN_CAT(conn, DMM, LOGL_DEBUG, "Rx CM SERVICE REQUEST cm_service_type=0x%02x\n",
			 req->cm_service_type);

	mi_type = (mi && mi_len) ? (mi[0] & GSM_MI_TYPE_MASK) : GSM_MI_TYPE_NONE;
	switch (mi_type) {
	case GSM_MI_TYPE_IMSI:
	case GSM_MI_TYPE_TMSI:
		/* continue below */
		break;
	case GSM_MI_TYPE_IMEI:
		if (req->cm_service_type == GSM48_CMSERV_EMERGENCY) {
			/* We don't do emergency calls by IMEI */
			LOG_RAN_CONN(conn, LOGL_NOTICE, "Tx CM SERVICE REQUEST REJECT\n");
			return msc_gsm48_tx_mm_serv_rej(conn, GSM48_REJECT_IMEI_NOT_ACCEPTED);
		}
		/* fall-through for non-emergency setup */
	default:
		LOG_RAN_CONN(conn, LOGL_ERROR, "MI type is not expected: %s\n", gsm48_mi_type_name(mi_type));
		return msc_gsm48_tx_mm_serv_rej(conn,
						GSM48_REJECT_INCORRECT_MESSAGE);
	}

	switch (req->cm_service_type) {
	case GSM48_CMSERV_MO_CALL_PACKET:
	case GSM48_CMSERV_EMERGENCY:
	case GSM48_CMSERV_SMS:
	case GSM48_CMSERV_SUP_SERV:
		/* continue below */
		break;
	default:
		return msc_gsm48_tx_mm_serv_rej(conn, GSM48_REJECT_SRV_OPT_NOT_SUPPORTED);
	}

	if (ran_conn_is_accepted(conn))
		return cm_serv_reuse_conn(conn, mi_p);

	osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_IDENTITY, mi_p);

	is_utran = (conn->via_ran == OSMO_RAT_UTRAN_IU);
	vlr_proc_acc_req(conn->fi,
			 RAN_CONN_E_ACCEPTED, RAN_CONN_E_CN_CLOSE, NULL,
			 net->vlr, conn,
			 VLR_PR_ARQ_T_CM_SERV_REQ, mi-1, &lai,
			 is_utran || conn->network->authentication_required,
			 is_utran || conn->network->a5_encryption_mask > 0x01,
			 req->cipher_key_seq,
			 classmark2_is_r99(classmark2, classmark2_len),
			 is_utran);

	/* From vlr_proc_acc_req() we expect an implicit dispatch of PR_ARQ_E_START we expect
	 * msc_vlr_subscr_assoc() to already have been called and completed. Has an error occured? */
	if (!conn->vsub) {
		LOG_RAN_CONN(conn, LOGL_ERROR, "subscriber not allowed to do a CM Service Request\n");
		return -EIO;
	}

	memcpy(conn->vsub->classmark.classmark2, classmark2, classmark2_len);
	conn->vsub->classmark.classmark2_len = classmark2_len;

	ran_conn_complete_layer_3(conn);
	return 0;
}

/* Receive a CM Re-establish Request */
static int gsm48_rx_cm_reest_req(struct ran_conn *conn, struct msgb *msg)
{
	uint8_t mi_type;
	char mi_string[GSM48_MI_SIZE];
	struct gsm48_hdr *gh = msgb_l3(msg);

	uint8_t classmark2_len = gh->data[1];
	uint8_t *classmark2 = gh->data+2;
	uint8_t mi_len = *(classmark2 + classmark2_len);
	uint8_t *mi = (classmark2 + classmark2_len + 1);

	gsm48_mi_to_string(mi_string, sizeof(mi_string), mi, mi_len);
	mi_type = mi[0] & GSM_MI_TYPE_MASK;
	DEBUGP(DMM, "<- CM RE-ESTABLISH REQUEST MI(%s)=%s\n", gsm48_mi_type_name(mi_type), mi_string);

	/* we don't support CM call re-establishment */
	return msc_gsm48_tx_mm_serv_rej(conn, GSM48_REJECT_SRV_OPT_NOT_SUPPORTED);
}

static int gsm48_rx_mm_imsi_detach_ind(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm_network *network = conn->network;
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm48_imsi_detach_ind *idi =
				(struct gsm48_imsi_detach_ind *) gh->data;
	uint8_t mi_type = idi->mi[0] & GSM_MI_TYPE_MASK;
	char mi_string[GSM48_MI_SIZE];
	struct vlr_subscr *vsub = NULL;

	gsm48_mi_to_string(mi_string, sizeof(mi_string), idi->mi, idi->mi_len);
	DEBUGP(DMM, "IMSI DETACH INDICATION: MI(%s)=%s\n",
	       gsm48_mi_type_name(mi_type), mi_string);

	rate_ctr_inc(&network->msc_ctrs->ctr[MSC_CTR_LOC_UPDATE_TYPE_DETACH]);

	switch (mi_type) {
	case GSM_MI_TYPE_TMSI:
		vsub = vlr_subscr_find_by_tmsi(network->vlr,
					       tmsi_from_string(mi_string));
		break;
	case GSM_MI_TYPE_IMSI:
		vsub = vlr_subscr_find_by_imsi(network->vlr, mi_string);
		break;
	case GSM_MI_TYPE_IMEI:
	case GSM_MI_TYPE_IMEISV:
		/* no sim card... FIXME: what to do ? */
		LOGP(DMM, LOGL_ERROR, "MI(%s)=%s: unimplemented mobile identity type\n",
		     gsm48_mi_type_name(mi_type), mi_string);
		break;
	default:
		LOGP(DMM, LOGL_ERROR, "MI(%s)=%s: unknown mobile identity type\n",
		     gsm48_mi_type_name(mi_type), mi_string);
		break;
	}

	if (!vsub) {
		LOGP(DMM, LOGL_ERROR, "IMSI DETACH for unknown subscriber MI(%s)=%s\n",
		     gsm48_mi_type_name(mi_type), mi_string);
	} else {
		LOGP(DMM, LOGL_INFO, "IMSI DETACH for %s\n", vlr_subscr_name(vsub));

		if (vsub->cs.is_paging)
			subscr_paging_cancel(vsub, GSM_PAGING_EXPIRED);

		/* We already got Classmark 1 during Location Updating ... but well, ok */
		vsub->classmark.classmark1 = idi->classmark1;

		vlr_subscr_rx_imsi_detach(vsub);
		osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_DETACHED, vsub);
		vlr_subscr_put(vsub);
	}

	ran_conn_close(conn, 0);
	return 0;
}

static int gsm48_rx_mm_status(struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);

	DEBUGP(DMM, "MM STATUS (reject cause 0x%02x)\n", gh->data[0]);

	return 0;
}

static int parse_gsm_auth_resp(uint8_t *res, uint8_t *res_len,
			       struct ran_conn *conn,
			       struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm48_auth_resp *ar = (struct gsm48_auth_resp*) gh->data;

	if (msgb_l3len(msg) < sizeof(*gh) + sizeof(*ar)) {
		LOGP(DMM, LOGL_ERROR,
		     "%s: MM AUTHENTICATION RESPONSE:"
		     " l3 length invalid: %u\n",
		     vlr_subscr_name(conn->vsub), msgb_l3len(msg));
		return -EINVAL;
	}

	*res_len = sizeof(ar->sres);
	memcpy(res, ar->sres, sizeof(ar->sres));
	return 0;
}

static int parse_umts_auth_resp(uint8_t *res, uint8_t *res_len,
				struct ran_conn *conn,
				struct msgb *msg)
{
	struct gsm48_hdr *gh;
	uint8_t *data;
	uint8_t iei;
	uint8_t ie_len;
	unsigned int data_len;

	/* First parse the GSM part */
	if (parse_gsm_auth_resp(res, res_len, conn, msg))
		return -EINVAL;
	OSMO_ASSERT(*res_len == 4);

	/* Then add the extended res part */
	gh = msgb_l3(msg);
	data = gh->data + sizeof(struct gsm48_auth_resp);
	data_len = msgb_l3len(msg) - (data - (uint8_t*)msgb_l3(msg));

	if (data_len < 3) {
		LOGP(DMM, LOGL_ERROR,
		     "%s: MM AUTHENTICATION RESPONSE:"
		     " l3 length invalid: %u\n",
		     vlr_subscr_name(conn->vsub), msgb_l3len(msg));
		return -EINVAL;
	}

	iei = data[0];
	ie_len = data[1];
	if (iei != GSM48_IE_AUTH_RES_EXT) {
		LOGP(DMM, LOGL_ERROR,
		     "%s: MM R99 AUTHENTICATION RESPONSE:"
		     " expected IEI 0x%02x, got 0x%02x\n",
		     vlr_subscr_name(conn->vsub),
		     GSM48_IE_AUTH_RES_EXT, iei);
		return -EINVAL;
	}

	if (ie_len > 12) {
		LOGP(DMM, LOGL_ERROR,
		     "%s: MM R99 AUTHENTICATION RESPONSE:"
		     " extended Auth Resp IE 0x%02x is too large: %u bytes\n",
		     vlr_subscr_name(conn->vsub), GSM48_IE_AUTH_RES_EXT, ie_len);
		return -EINVAL;
	}

	*res_len += ie_len;
	memcpy(res + 4, &data[2], ie_len);
	return 0;
}

/* Chapter 9.2.3: Authentication Response */
static int gsm48_rx_mm_auth_resp(struct ran_conn *conn, struct msgb *msg)
{
	uint8_t res[16];
	uint8_t res_len;
	int rc;
	bool is_umts;

	if (!conn->vsub) {
		LOGP(DMM, LOGL_ERROR,
		     "MM AUTHENTICATION RESPONSE: invalid: no subscriber\n");
		ran_conn_close(conn, GSM_CAUSE_AUTH_FAILED);
		return -EINVAL;
	}

	is_umts = (msgb_l3len(msg) > sizeof(struct gsm48_hdr) + sizeof(struct gsm48_auth_resp));

	if (is_umts)
		rc = parse_umts_auth_resp(res, &res_len, conn, msg);
	else
		rc = parse_gsm_auth_resp(res, &res_len, conn, msg);

	if (rc) {
		LOGP(DMM, LOGL_ERROR,
		     "%s: MM AUTHENTICATION RESPONSE: invalid: parsing %s AKA Auth Response"
		     " failed with rc=%d; dispatching zero length SRES/RES to trigger failure\n",
		     vlr_subscr_name(conn->vsub), is_umts ? "UMTS" : "GSM", rc);
		memset(res, 0, sizeof(res));
		res_len = 0;
	}

	DEBUGP(DMM, "%s: MM %s AUTHENTICATION RESPONSE (%s = %s)\n",
	       vlr_subscr_name(conn->vsub),
	       is_umts ? "UMTS" : "GSM", is_umts ? "res" : "sres",
	       osmo_hexdump_nospc(res, res_len));

	return vlr_subscr_rx_auth_resp(conn->vsub, classmark_is_r99(&conn->vsub->classmark),
				       conn->via_ran == OSMO_RAT_UTRAN_IU,
				       res, res_len);
}

static int gsm48_rx_mm_auth_fail(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	uint8_t cause;
	uint8_t auts_tag;
	uint8_t auts_len;
	uint8_t *auts;

	if (!conn->vsub) {
		LOGP(DMM, LOGL_ERROR,
		     "MM R99 AUTHENTICATION FAILURE: invalid: no subscriber\n");
		ran_conn_close(conn, GSM_CAUSE_AUTH_FAILED);
		return -EINVAL;
	}

	if (msgb_l3len(msg) < sizeof(*gh) + 1) {
		LOGP(DMM, LOGL_ERROR,
		     "%s: MM R99 AUTHENTICATION FAILURE:"
		     " l3 length invalid: %u\n",
		     vlr_subscr_name(conn->vsub), msgb_l3len(msg));
		ran_conn_close(conn, GSM_CAUSE_AUTH_FAILED);
		return -EINVAL;
	}

	cause = gh->data[0];

	if (cause != GSM48_REJECT_SYNCH_FAILURE) {
		LOGP(DMM, LOGL_INFO,
		     "%s: MM R99 AUTHENTICATION FAILURE: cause 0x%0x\n",
		     vlr_subscr_name(conn->vsub), cause);
		vlr_subscr_rx_auth_fail(conn->vsub, NULL);
		return 0;
	}

	/* This is a Synch Failure procedure, which should pass an AUTS to
	 * resynchronize the sequence nr with the HLR. Expecting exactly one
	 * TLV with 14 bytes of AUTS. */

	if (msgb_l3len(msg) < sizeof(*gh) + 1 + 2) {
		LOGP(DMM, LOGL_INFO,
		     "%s: MM R99 AUTHENTICATION FAILURE:"
		     " invalid Synch Failure: missing AUTS IE\n",
		     vlr_subscr_name(conn->vsub));
		ran_conn_close(conn, GSM_CAUSE_AUTH_FAILED);
		return -EINVAL;
	}

	auts_tag = gh->data[1];
	auts_len = gh->data[2];
	auts = &gh->data[3];

	if (auts_tag != GSM48_IE_AUTS
	    || auts_len != 14) {
		LOGP(DMM, LOGL_INFO,
		     "%s: MM R99 AUTHENTICATION FAILURE:"
		     " invalid Synch Failure:"
		     " expected AUTS IE 0x%02x of 14 bytes,"
		     " got IE 0x%02x of %u bytes\n",
		     vlr_subscr_name(conn->vsub),
		     GSM48_IE_AUTS, auts_tag, auts_len);
		ran_conn_close(conn, GSM_CAUSE_AUTH_FAILED);
		return -EINVAL;
	}

	if (msgb_l3len(msg) < sizeof(*gh) + 1 + 2 + auts_len) {
		LOGP(DMM, LOGL_INFO,
		     "%s: MM R99 AUTHENTICATION FAILURE:"
		     " invalid Synch Failure msg: message truncated (%u)\n",
		     vlr_subscr_name(conn->vsub), msgb_l3len(msg));
		ran_conn_close(conn, GSM_CAUSE_AUTH_FAILED);
		return -EINVAL;
	}

	/* We have an AUTS IE with exactly 14 bytes of AUTS and the msgb is
	 * large enough. */

	DEBUGP(DMM, "%s: MM R99 AUTHENTICATION SYNCH (AUTS = %s)\n",
	       vlr_subscr_name(conn->vsub), osmo_hexdump_nospc(auts, 14));

	return vlr_subscr_rx_auth_fail(conn->vsub, auts);
}

static int gsm48_rx_mm_tmsi_reall_compl(struct ran_conn *conn)
{
	DEBUGP(DMM, "TMSI Reallocation Completed. Subscriber: %s\n",
	       vlr_subscr_name(conn->vsub));
	if (!conn->vsub) {
		LOGP(DMM, LOGL_ERROR,
		     "Rx MM TMSI Reallocation Complete: invalid: no subscriber\n");
		return -EINVAL;
	}
	return vlr_subscr_rx_tmsi_reall_compl(conn->vsub);
}

/* Receive a GSM 04.08 Mobility Management (MM) message */
static int gsm0408_rcv_mm(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	int rc = 0;

	switch (gsm48_hdr_msg_type(gh)) {
	case GSM48_MT_MM_LOC_UPD_REQUEST:
		rc = mm_rx_loc_upd_req(conn, msg);
		break;
	case GSM48_MT_MM_ID_RESP:
		rc = mm_rx_id_resp(conn, msg);
		break;
	case GSM48_MT_MM_CM_SERV_REQ:
		rc = gsm48_rx_mm_serv_req(conn, msg);
		break;
	case GSM48_MT_MM_STATUS:
		rc = gsm48_rx_mm_status(msg);
		break;
	case GSM48_MT_MM_TMSI_REALL_COMPL:
		rc = gsm48_rx_mm_tmsi_reall_compl(conn);
		break;
	case GSM48_MT_MM_IMSI_DETACH_IND:
		rc = gsm48_rx_mm_imsi_detach_ind(conn, msg);
		break;
	case GSM48_MT_MM_CM_REEST_REQ:
		rc = gsm48_rx_cm_reest_req(conn, msg);
		break;
	case GSM48_MT_MM_AUTH_RESP:
		rc = gsm48_rx_mm_auth_resp(conn, msg);
		break;
	case GSM48_MT_MM_AUTH_FAIL:
		rc = gsm48_rx_mm_auth_fail(conn, msg);
		break;
	default:
		LOGP(DMM, LOGL_NOTICE, "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_rx_rr_pag_resp(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm_network *net = conn->network;
	struct gsm48_hdr *gh = msgb_l3(msg);
	struct gsm48_pag_resp *pr =
			(struct gsm48_pag_resp *)gh->data;
	uint8_t classmark2_len = gh->data[1];
	uint8_t *classmark2 = gh->data+2;
	uint8_t *mi_lv = classmark2 + classmark2_len;
	struct osmo_location_area_id lai;
	bool is_utran;

	lai.plmn = conn->network->plmn;
	lai.lac = conn->lac;

	if (ran_conn_is_establishing_auth_ciph(conn)) {
		LOGP(DMM, LOGL_ERROR,
		     "Ignoring Paging Response, conn already busy establishing authenticity\n");
		return 0;
	}

	if (ran_conn_is_accepted(conn)) {
		LOGP(DMM, LOGL_ERROR, "Ignoring Paging Response, conn already established\n");
		return 0;
	}

	conn->complete_layer3_type = COMPLETE_LAYER3_PAGING_RESP;
	ran_conn_update_id_from_mi(conn, mi_lv + 1, *mi_lv);
	LOG_RAN_CONN_CAT(conn, DRR, LOGL_DEBUG, "PAGING RESPONSE\n");

	is_utran = (conn->via_ran == OSMO_RAT_UTRAN_IU);
	vlr_proc_acc_req(conn->fi,
			 RAN_CONN_E_ACCEPTED, RAN_CONN_E_CN_CLOSE, NULL,
			 net->vlr, conn,
			 VLR_PR_ARQ_T_PAGING_RESP, mi_lv, &lai,
			 is_utran || conn->network->authentication_required,
			 is_utran || conn->network->a5_encryption_mask > 0x01,
			 pr->key_seq,
			 classmark2_is_r99(classmark2, classmark2_len),
			 is_utran);

	/* From vlr_proc_acc_req() we expect an implicit dispatch of PR_ARQ_E_START we expect
	 * msc_vlr_subscr_assoc() to already have been called and completed. Has an error occured? */
	if (!conn->vsub) {
		LOG_RAN_CONN(conn, LOGL_ERROR, "subscriber not allowed to do a Paging Response\n");
		return -EIO;
	}

	memcpy(conn->vsub->classmark.classmark2, classmark2, classmark2_len);
	conn->vsub->classmark.classmark2_len = classmark2_len;

	ran_conn_complete_layer_3(conn);
	return 0;
}

static int gsm48_rx_rr_app_info(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm48_hdr *gh = msgb_l3(msg);
	uint8_t apdu_id_flags;
	uint8_t apdu_len;
	uint8_t *apdu_data;

	apdu_id_flags = gh->data[0];
	apdu_len = gh->data[1];
	apdu_data = gh->data+2;

	DEBUGP(DRR, "RX APPLICATION INFO id/flags=0x%02x apdu_len=%u apdu=%s\n",
		apdu_id_flags, apdu_len, osmo_hexdump(apdu_data, apdu_len));

	/* we're not using the app info blob anywhere, so ignore. */
#if 0
	return db_apdu_blob_store(conn->subscr, apdu_id_flags, apdu_len, apdu_data);
#else
	return 0;
#endif
}

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

	switch (gh->msg_type) {
	case GSM48_MT_RR_PAG_RESP:
		rc = gsm48_rx_rr_pag_resp(conn, msg);
		break;
	case GSM48_MT_RR_APP_INFO:
		rc = gsm48_rx_rr_app_info(conn, msg);
		break;
	default:
		LOGP(DRR, LOGL_NOTICE, "MSC: Unimplemented %s GSM 04.08 RR "
		     "message\n", gsm48_rr_msg_name(gh->msg_type));
		break;
	}

	return rc;
}

int gsm48_send_rr_app_info(struct ran_conn *conn, uint8_t apdu_id,
			   uint8_t apdu_len, const uint8_t *apdu)
{
	struct msgb *msg = gsm48_msgb_alloc_name("GSM 04.08 APP INF");
	struct gsm48_hdr *gh;

	DEBUGP(DRR, "TX APPLICATION INFO id=0x%02x, len=%u\n",
		apdu_id, apdu_len);

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 2 + apdu_len);
	gh->proto_discr = GSM48_PDISC_RR;
	gh->msg_type = GSM48_MT_RR_APP_INFO;
	gh->data[0] = apdu_id;
	gh->data[1] = apdu_len;
	memcpy(gh->data+2, apdu, apdu_len);

	return gsm48_conn_sendmsg(msg, conn, NULL);
}

static bool msg_is_initially_permitted(const struct gsm48_hdr *hdr)
{
	uint8_t pdisc = gsm48_hdr_pdisc(hdr);
	uint8_t msg_type = gsm48_hdr_msg_type(hdr);

	switch (pdisc) {
	case GSM48_PDISC_MM:
		switch (msg_type) {
		case GSM48_MT_MM_LOC_UPD_REQUEST:
		case GSM48_MT_MM_CM_SERV_REQ:
		case GSM48_MT_MM_CM_REEST_REQ:
		case GSM48_MT_MM_AUTH_RESP:
		case GSM48_MT_MM_AUTH_FAIL:
		case GSM48_MT_MM_ID_RESP:
		case GSM48_MT_MM_TMSI_REALL_COMPL:
		case GSM48_MT_MM_IMSI_DETACH_IND:
			return true;
		default:
			break;
		}
		break;
	case GSM48_PDISC_RR:
		switch (msg_type) {
		/* GSM48_MT_RR_CIPH_M_COMPL is actually handled in bssmap_rx_ciph_compl() and gets redirected in the
		 * BSSAP layer to ran_conn_cipher_mode_compl() (before this here is reached) */
		case GSM48_MT_RR_PAG_RESP:
			return true;
		default:
			break;
		}
		break;
	default:
		break;
	}

	return false;
}

void cm_service_request_concludes(struct ran_conn *conn,
				  struct msgb *msg)
{

	/* If a CM Service Request was received before, this is the request the
	 * conn was opened for. No need to wait for further messages. */

	if (!conn->received_cm_service_request)
		return;

	if (log_check_level(DMM, LOGL_DEBUG)) {
		struct gsm48_hdr *gh = msgb_l3(msg);
		uint8_t pdisc = gsm48_hdr_pdisc(gh);
		uint8_t msg_type = gsm48_hdr_msg_type(gh);

		DEBUGP(DMM, "%s: rx msg %s:"
		       " received_cm_service_request changes to false\n",
		       vlr_subscr_name(conn->vsub),
		       gsm48_pdisc_msgtype_name(pdisc, msg_type));
	}
	conn->received_cm_service_request = false;
	ran_conn_put(conn, RAN_CONN_USE_CM_SERVICE);
}

/* TS 24.007 11.2.3.2.3 Message Type Octet / Duplicate Detection */
int gsm0407_pdisc_ctr_bin(uint8_t pdisc)
{
	switch (pdisc) {
	case GSM48_PDISC_MM:
	case GSM48_PDISC_CC:
	case GSM48_PDISC_NC_SS:
		return 0;
	case GSM48_PDISC_GROUP_CC:
		return 1;
	case GSM48_PDISC_BCAST_CC:
		return 2;
	case GSM48_PDISC_LOC:
		return 3;
	default:
		return -1;
	}
}

/* extract the N(SD) and return the modulo value for a R98 message */
static uint8_t gsm0407_determine_nsd_ret_modulo_r99(uint8_t pdisc, uint8_t msg_type, uint8_t *n_sd)
{
	switch (pdisc) {
	case GSM48_PDISC_MM:
	case GSM48_PDISC_CC:
	case GSM48_PDISC_NC_SS:
		*n_sd = (msg_type >> 6) & 0x3;
		return 4;
	case GSM48_PDISC_GROUP_CC:
	case GSM48_PDISC_BCAST_CC:
	case GSM48_PDISC_LOC:
		*n_sd = (msg_type >> 6) & 0x1;
		return 2;
	default:
		/* no sequence number, we cannot detect dups */
		return 0;
	}
}

/* extract the N(SD) and return the modulo value for a R99 message */
static uint8_t gsm0407_determine_nsd_ret_modulo_r98(uint8_t pdisc, uint8_t msg_type, uint8_t *n_sd)
{
	switch (pdisc) {
	case GSM48_PDISC_MM:
	case GSM48_PDISC_CC:
	case GSM48_PDISC_NC_SS:
	case GSM48_PDISC_GROUP_CC:
	case GSM48_PDISC_BCAST_CC:
	case GSM48_PDISC_LOC:
		*n_sd = (msg_type >> 6) & 0x1;
		return 2;
	default:
		/* no sequence number, we cannot detect dups */
		return 0;
	}
}

/* TS 24.007 11.2.3.2 Message Type Octet / Duplicate Detection */
static bool gsm0407_is_duplicate(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm48_hdr *gh;
	uint8_t pdisc;
	uint8_t n_sd, modulo;
	int bin;

	gh = msgb_l3(msg);
	pdisc = gsm48_hdr_pdisc(gh);

	if (conn->vsub && classmark_is_r99(&conn->vsub->classmark)) {
		modulo = gsm0407_determine_nsd_ret_modulo_r99(pdisc, gh->msg_type, &n_sd);
	} else { /* pre R99 */
		modulo = gsm0407_determine_nsd_ret_modulo_r98(pdisc, gh->msg_type, &n_sd);
	}
	if (modulo == 0)
		return false;
	bin = gsm0407_pdisc_ctr_bin(pdisc);
	if (bin < 0)
		return false;

	OSMO_ASSERT(bin < ARRAY_SIZE(conn->n_sd_next));
	if (n_sd != conn->n_sd_next[bin]) {
		/* not what we expected: duplicate */
		return true;
	} else {
		/* as expected: no dup; update expected counter for next message */
		conn->n_sd_next[bin] = (n_sd + 1) % modulo;
		return false;
	}
}

extern int gsm0408_rcv_cc(struct ran_conn *conn, struct msgb *msg);

/* Main entry point for GSM 04.08/44.008 Layer 3 data (e.g. from the BSC). */
int gsm0408_dispatch(struct ran_conn *conn, struct msgb *msg)
{
	struct gsm48_hdr *gh;
	uint8_t pdisc;
	int rc = 0;

	OSMO_ASSERT(msg->l3h);
	OSMO_ASSERT(conn);
	OSMO_ASSERT(msg);

	gh = msgb_l3(msg);
	pdisc = gsm48_hdr_pdisc(gh);

	if (gsm0407_is_duplicate(conn, msg)) {
		LOGP(DRLL, LOGL_NOTICE, "%s: Discarding duplicate L3 message\n",
			(conn && conn->vsub) ? vlr_subscr_name(conn->vsub) : "UNKNOWN");
		return 0;
	}

	LOGP(DRLL, LOGL_DEBUG, "Dispatching 04.08 message %s (0x%x:0x%x)\n",
	     gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh)),
	     pdisc, gsm48_hdr_msg_type(gh));

	if (!ran_conn_is_accepted(conn)
	    && !msg_is_initially_permitted(gh)) {
		LOGP(DRLL, LOGL_ERROR,
		     "subscr %s: Message not permitted for initial conn: %s\n",
		     vlr_subscr_name(conn->vsub),
		     gsm48_pdisc_msgtype_name(pdisc, gsm48_hdr_msg_type(gh)));
		return -EACCES;
	}

	if (conn->vsub && conn->vsub->cs.attached_via_ran != conn->via_ran) {
		LOGP(DMM, LOGL_ERROR,
		     "%s: Illegal situation: RAN type mismatch:"
		     " attached via %s, received message via %s\n",
		     vlr_subscr_name(conn->vsub),
		     osmo_rat_type_name(conn->vsub->cs.attached_via_ran),
		     osmo_rat_type_name(conn->via_ran));
		return -EACCES;
	}

#if 0
	if (silent_call_reroute(conn, msg))
		return silent_call_rx(conn, msg);
#endif

	switch (pdisc) {
	case GSM48_PDISC_CC:
		rc = gsm0408_rcv_cc(conn, msg);
		break;
	case GSM48_PDISC_MM:
		rc = gsm0408_rcv_mm(conn, msg);
		break;
	case GSM48_PDISC_RR:
		rc = gsm0408_rcv_rr(conn, msg);
		break;
	case GSM48_PDISC_SMS:
		rc = gsm0411_rcv_sms(conn, msg);
		break;
	case GSM48_PDISC_MM_GPRS:
	case GSM48_PDISC_SM_GPRS:
		LOGP(DRLL, LOGL_NOTICE, "Unimplemented "
			"GSM 04.08 discriminator 0x%02x\n", pdisc);
		rc = -ENOTSUP;
		break;
	case GSM48_PDISC_NC_SS:
		rc = gsm0911_rcv_nc_ss(conn, msg);
		break;
	case GSM48_PDISC_TEST:
		rc = gsm0414_rcv_test(conn, msg);
		break;
	default:
		LOGP(DRLL, LOGL_NOTICE, "Unknown "
			"GSM 04.08 discriminator 0x%02x\n", pdisc);
		rc = -EINVAL;
		break;
	}

	return rc;
}

/***********************************************************************
 * VLR integration
 ***********************************************************************/

/* VLR asks us to send an authentication request */
static int msc_vlr_tx_auth_req(void *msc_conn_ref, struct vlr_auth_tuple *at,
			       bool send_autn)
{
	struct ran_conn *conn = msc_conn_ref;
	return gsm48_tx_mm_auth_req(conn, at->vec.rand,
				    send_autn? at->vec.autn : NULL,
				    at->key_seq);
}

/* VLR asks us to send an authentication reject */
static int msc_vlr_tx_auth_rej(void *msc_conn_ref)
{
	struct ran_conn *conn = msc_conn_ref;
	return gsm48_tx_mm_auth_rej(conn);
}

/* VLR asks us to transmit an Identity Request of given type */
static int msc_vlr_tx_id_req(void *msc_conn_ref, uint8_t mi_type)
{
	struct ran_conn *conn = msc_conn_ref;
	return mm_tx_identity_req(conn, mi_type);
}

/* VLR asks us to transmit a Location Update Accept */
static int msc_vlr_tx_lu_acc(void *msc_conn_ref, uint32_t send_tmsi)
{
	struct ran_conn *conn = msc_conn_ref;
	return gsm0408_loc_upd_acc(conn, send_tmsi);
}

/* VLR asks us to transmit a Location Update Reject */
static int msc_vlr_tx_lu_rej(void *msc_conn_ref, enum gsm48_reject_value cause)
{
	struct ran_conn *conn = msc_conn_ref;
	return gsm0408_loc_upd_rej(conn, cause);
}

/* VLR asks us to transmit a CM Service Accept */
static int msc_vlr_tx_cm_serv_acc(void *msc_conn_ref)
{
	struct ran_conn *conn = msc_conn_ref;
	return msc_gsm48_tx_mm_serv_ack(conn);
}

static int msc_vlr_tx_common_id(void *msc_conn_ref)
{
	struct ran_conn *conn = msc_conn_ref;
	return msc_tx_common_id(conn);
}

/* VLR asks us to transmit MM info. */
static int msc_vlr_tx_mm_info(void *msc_conn_ref)
{
	struct ran_conn *conn = msc_conn_ref;
	if (!conn->network->send_mm_info)
		return 0;
	return gsm48_tx_mm_info(conn);
}

/* VLR asks us to transmit a CM Service Reject */
static int msc_vlr_tx_cm_serv_rej(void *msc_conn_ref, enum gsm48_reject_value cause)
{
	struct ran_conn *conn = msc_conn_ref;
	int rc;

	rc = msc_gsm48_tx_mm_serv_rej(conn, cause);

	if (conn->received_cm_service_request) {
		conn->received_cm_service_request = false;
		ran_conn_put(conn, RAN_CONN_USE_CM_SERVICE);
	}

	return rc;
}

/* For msc_vlr_set_ciph_mode() */
osmo_static_assert(sizeof(((struct gsm0808_encrypt_info*)0)->key) >= sizeof(((struct osmo_auth_vector*)0)->kc),
		   gsm0808_encrypt_info_key_fits_osmo_auth_vec_kc);

int ran_conn_geran_set_cipher_mode(struct ran_conn *conn, bool umts_aka, bool retrieve_imeisv)
{
	struct gsm_network *net;
	struct gsm0808_encrypt_info ei;
	int i, j = 0;
	int request_classmark = 0;
	int request_classmark_for_a5_n = 0;
	struct vlr_auth_tuple *tuple;

	if (!conn || !conn->vsub || !conn->vsub->last_tuple) {
		/* This should really never happen, because we checked this in msc_vlr_set_ciph_mode()
		 * already. */
		LOGP(DMM, LOGL_ERROR, "Internal error: missing state during Ciphering Mode Command\n");
		return -EINVAL;
	}

	net = conn->network;
        tuple = conn->vsub->last_tuple;

	for (i = 0; i < 8; i++) {
		int supported;

		/* A5/n permitted by osmo-msc.cfg? */
		if (!(net->a5_encryption_mask & (1 << i)))
			continue;

		/* A5/n supported by MS? */
		supported = classmark_supports_a5(&conn->vsub->classmark, i);
		if (supported == 1) {
			ei.perm_algo[j++] = vlr_ciph_to_gsm0808_alg_id(i);
			/* A higher A5/n is supported, so no need to request a Classmark
			 * for support of a lesser A5/n. */
			request_classmark = 0;
		} else if (supported < 0) {
			request_classmark = -supported;
			request_classmark_for_a5_n = i;
		}
	}
	ei.perm_algo_len = j;

	if (request_classmark) {
		/* The highest A5/n as from osmo-msc.cfg might be available, but we are
		 * still missing the Classmark information for that from the MS. First
		 * ask for that. */
		LOGP(DMM, LOGL_DEBUG, "%s: to determine whether A5/%d is supported,"
		     " first ask for a Classmark Update to obtain Classmark %d\n",
		     vlr_subscr_name(conn->vsub), request_classmark_for_a5_n,
		     request_classmark);

		return ran_conn_classmark_request_then_cipher_mode_cmd(conn, umts_aka, retrieve_imeisv);
	}

	if (ei.perm_algo_len == 0) {
		LOGP(DMM, LOGL_ERROR, "%s: cannot start ciphering, no intersection "
		     "between MSC-configured and MS-supported A5 algorithms. MSC: %x  MS: %s\n",
		     vlr_subscr_name(conn->vsub), net->a5_encryption_mask,
		     classmark_a5_name(&conn->vsub->classmark));
		return -ENOTSUP;
	}

	DEBUGP(DMM, "-> CIPHER MODE COMMAND %s\n", vlr_subscr_name(conn->vsub));

	tuple = conn->vsub->last_tuple;

	/* In case of UMTS AKA, the Kc for ciphering must be derived from the 3G auth
	 * tokens.  tuple->vec.kc was calculated from the GSM algorithm and is not
	 * necessarily a match for the UMTS AKA tokens. */
	if (umts_aka)
		osmo_auth_c3(ei.key, tuple->vec.ck, tuple->vec.ik);
	else
		memcpy(ei.key, tuple->vec.kc, sizeof(tuple->vec.kc));
	ei.key_len = sizeof(tuple->vec.kc);

	conn->geran_encr = (struct geran_encr){};
	if (ei.key_len <= sizeof(conn->geran_encr.key)) {
		memcpy(conn->geran_encr.key, ei.key, ei.key_len);
		conn->geran_encr.key_len = ei.key_len;
	}
	/* conn->geran_encr.alg_id remains unknown until we receive a Cipher Mode Complete from the BSC */

	return a_iface_tx_cipher_mode(conn, &ei, retrieve_imeisv);
}

/* VLR asks us to start using ciphering.
 * (Keep non-static to allow regression testing on this function.) */
int msc_vlr_set_ciph_mode(void *msc_conn_ref,
			  bool umts_aka,
			  bool retrieve_imeisv)
{
	struct ran_conn *conn = msc_conn_ref;
	struct vlr_subscr *vsub;
	struct vlr_auth_tuple *tuple;

	if (!conn || !conn->vsub) {
		LOGP(DMM, LOGL_ERROR, "Cannot send Ciphering Mode Command to"
		     " NULL conn/subscriber");
		return -EINVAL;
	}

	vsub = conn->vsub;
	tuple = vsub->last_tuple;

	if (!tuple) {
		LOGP(DMM, LOGL_ERROR, "subscr %s: Cannot send Ciphering Mode"
		     " Command: no auth tuple available\n",
		     vlr_subscr_name(vsub));
		return -EINVAL;
	}

	switch (conn->via_ran) {
	case OSMO_RAT_GERAN_A:
		return ran_conn_geran_set_cipher_mode(conn, umts_aka, retrieve_imeisv);

	case OSMO_RAT_UTRAN_IU:
#ifdef BUILD_IU
		DEBUGP(DMM, "-> SECURITY MODE CONTROL %s\n",
		       vlr_subscr_name(conn->vsub));
		return ranap_iu_tx_sec_mode_cmd(conn->iu.ue_ctx, &tuple->vec, 0, 1);
#else
		LOGP(DMM, LOGL_ERROR, "Cannot send Security Mode Control over OSMO_RAT_UTRAN_IU,"
		     " built without Iu support\n");
		return -ENOTSUP;
#endif

	default:
		break;
	}
	LOGP(DMM, LOGL_ERROR,
	     "%s: cannot start ciphering, unknown RAN type %d\n",
	     vlr_subscr_name(conn->vsub), conn->via_ran);
	return -ENOTSUP;
}

void ran_conn_rx_sec_mode_compl(struct ran_conn *conn)
{
	struct vlr_ciph_result vlr_res = {};

	if (!conn || !conn->vsub) {
		LOGP(DMM, LOGL_ERROR,
		     "Rx Security Mode Complete for invalid conn\n");
		return;
	}

	DEBUGP(DMM, "<- SECURITY MODE COMPLETE %s\n",
	       vlr_subscr_name(conn->vsub));

	vlr_res.cause = VLR_CIPH_COMPL;
	vlr_subscr_rx_ciph_res(conn->vsub, &vlr_res);
}

/* VLR informs us that the subscriber data has somehow been modified */
static void msc_vlr_subscr_update(struct vlr_subscr *subscr)
{
	LOGVSUBP(LOGL_NOTICE, subscr, "VLR: update for IMSI=%s (MSISDN=%s, used=%d)\n",
		 subscr->imsi, subscr->msisdn, subscr->use_count);
	ran_conn_update_id_for_vsub(subscr);
}

static void update_classmark(const struct gsm_classmark *src, struct gsm_classmark *dst)
{
	if (src->classmark1_set) {
		dst->classmark1 = src->classmark1;
		dst->classmark1_set = true;
	}
	if (src->classmark2_len) {
		dst->classmark2_len = src->classmark2_len;
		memcpy(dst->classmark2, src->classmark2, sizeof(dst->classmark2));
	}
	if (src->classmark3_len) {
		dst->classmark3_len = src->classmark3_len;
		memcpy(dst->classmark3, src->classmark3, sizeof(dst->classmark3));
	}
}

/* VLR informs us that the subscriber has been associated with a conn */
static int msc_vlr_subscr_assoc(void *msc_conn_ref,
				 struct vlr_subscr *vsub)
{
	struct ran_conn *conn = msc_conn_ref;
	OSMO_ASSERT(vsub);
	if (conn->vsub) {
		if (conn->vsub == vsub)
			LOG_RAN_CONN(conn, LOGL_NOTICE, "msc_vlr_subscr_assoc(): conn already associated with %s\n",
				     vlr_subscr_name(vsub));
		else {
			LOG_RAN_CONN(conn, LOGL_ERROR, "msc_vlr_subscr_assoc(): conn already associated with a subscriber,"
				     " cannot associate with %s\n", vlr_subscr_name(vsub));
			return -EINVAL;
		}
	}

	conn->vsub = vlr_subscr_get(vsub);
	OSMO_ASSERT(conn->vsub);
	conn->vsub->cs.attached_via_ran = conn->via_ran;

	/* In case we have already received Classmark Information before the VLR Subscriber was
	 * associated with the conn: merge the new Classmark into vsub->classmark. Don't overwrite valid
	 * vsub->classmark with unset classmark, though. */
	update_classmark(&conn->temporary_classmark, &conn->vsub->classmark);
	ran_conn_update_id(conn);
	return 0;
}

static int msc_vlr_route_gsup_msg(struct vlr_subscr *vsub,
				  struct osmo_gsup_message *gsup_msg)
{
	switch (gsup_msg->message_type) {
	/* GSM 09.11 code implementing SS/USSD */
	case OSMO_GSUP_MSGT_PROC_SS_REQUEST:
	case OSMO_GSUP_MSGT_PROC_SS_RESULT:
	case OSMO_GSUP_MSGT_PROC_SS_ERROR:
		DEBUGP(DMSC, "Routed to GSM 09.11 SS/USSD handler\n");
		return gsm0911_gsup_handler(vsub, gsup_msg);

	/* GSM 04.11 code implementing MO SMS */
	case OSMO_GSUP_MSGT_MO_FORWARD_SM_ERROR:
	case OSMO_GSUP_MSGT_MO_FORWARD_SM_RESULT:
	case OSMO_GSUP_MSGT_READY_FOR_SM_ERROR:
	case OSMO_GSUP_MSGT_READY_FOR_SM_RESULT:
		DEBUGP(DMSC, "Routed to GSM 04.11 MO handler\n");
		return gsm411_gsup_mo_handler(vsub, gsup_msg);

	/* GSM 04.11 code implementing MT SMS */
	case OSMO_GSUP_MSGT_MT_FORWARD_SM_REQUEST:
		DEBUGP(DMSC, "Routed to GSM 04.11 MT handler\n");
		return gsm411_gsup_mt_handler(vsub, gsup_msg);

	default:
		LOGP(DMM, LOGL_ERROR, "No handler found for %s, dropping message...\n",
			osmo_gsup_message_type_name(gsup_msg->message_type));
		return -GMM_CAUSE_MSGT_NOTEXIST_NOTIMPL;
	}
}

/* operations that we need to implement for libvlr */
static const struct vlr_ops msc_vlr_ops = {
	.tx_auth_req = msc_vlr_tx_auth_req,
	.tx_auth_rej = msc_vlr_tx_auth_rej,
	.tx_id_req = msc_vlr_tx_id_req,
	.tx_lu_acc = msc_vlr_tx_lu_acc,
	.tx_lu_rej = msc_vlr_tx_lu_rej,
	.tx_cm_serv_acc = msc_vlr_tx_cm_serv_acc,
	.tx_cm_serv_rej = msc_vlr_tx_cm_serv_rej,
	.set_ciph_mode = msc_vlr_set_ciph_mode,
	.tx_common_id = msc_vlr_tx_common_id,
	.tx_mm_info = msc_vlr_tx_mm_info,
	.subscr_update = msc_vlr_subscr_update,
	.subscr_assoc = msc_vlr_subscr_assoc,
	.forward_gsup_msg = msc_vlr_route_gsup_msg,
};

/* Allocate net->vlr so that the VTY may configure the VLR's data structures */
int msc_vlr_alloc(struct gsm_network *net)
{
	net->vlr = vlr_alloc(net, &msc_vlr_ops);
	if (!net->vlr)
		return -ENOMEM;
	net->vlr->user_ctx = net;
	return 0;
}

/* Launch the VLR, i.e. its GSUP connection */
int msc_vlr_start(struct gsm_network *net)
{
	struct ipaccess_unit *ipa_dev;

	OSMO_ASSERT(net->vlr);

	ipa_dev = talloc_zero(net->vlr, struct ipaccess_unit);
	ipa_dev->unit_name = "MSC";
	ipa_dev->serno = net->msc_ipa_name; /* NULL unless configured via VTY */
	ipa_dev->swversion = PACKAGE_NAME "-" PACKAGE_VERSION;

	return vlr_start(ipa_dev, net->vlr, net->gsup_server_addr_str, net->gsup_server_port);
}

struct msgb *gsm48_create_mm_serv_rej(enum gsm48_reject_value value)
{
	struct msgb *msg;
	struct gsm48_hdr *gh;

	msg = gsm48_msgb_alloc_name("GSM 04.08 SERV REJ");
	if (!msg)
		return NULL;

	gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh) + 1);
	gh->proto_discr = GSM48_PDISC_MM;
	gh->msg_type = GSM48_MT_MM_CM_SERV_REJ;
	gh->data[0] = value;

	return msg;
}

struct msgb *gsm48_create_loc_upd_rej(uint8_t cause)
{
	struct gsm48_hdr *gh;
	struct msgb *msg;

	msg = gsm48_msgb_alloc_name("GSM 04.08 LOC UPD REJ");
	if (!msg)
		return NULL;

	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;
	return msg;
}

int gsm48_extract_mi(uint8_t *classmark2_lv, int length, char *mi_string, uint8_t *mi_type)
{
	/* Check the size for the classmark */
	if (length < 1 + *classmark2_lv)
		return -1;

	uint8_t *mi_lv = classmark2_lv + *classmark2_lv + 1;
	if (length < 2 + *classmark2_lv + mi_lv[0])
		return -2;

	*mi_type = mi_lv[1] & GSM_MI_TYPE_MASK;
	return gsm48_mi_to_string(mi_string, GSM48_MI_SIZE, mi_lv+1, *mi_lv);
}

int gsm48_paging_extract_mi(struct gsm48_pag_resp *resp, int length,
			    char *mi_string, uint8_t *mi_type)
{
	static const uint32_t classmark_offset =
		offsetof(struct gsm48_pag_resp, classmark2);
	uint8_t *classmark2_lv = (uint8_t *) &resp->classmark2;
	return gsm48_extract_mi(classmark2_lv, length - classmark_offset,
				mi_string, mi_type);
}