summaryrefslogtreecommitdiffstats
path: root/3rdparty/openpgm-svn-r1085/pgm/if.c
blob: f034758f2a41ba6b284f4dd4c304972c84debdeb (plain) (blame)
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
/* vim:ts=8:sts=8:sw=4:noai:noexpandtab
 *
 * network interface handling.
 *
 * Copyright (c) 2006-2010 Miru Limited.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#define _GNU_SOURCE
#include <errno.h>
#include <ctype.h>
#include <stdio.h>
#ifndef _WIN32
#	include <sys/types.h>
#	include <sys/socket.h>
#	include <netdb.h>		/* _GNU_SOURCE for EAI_NODATA */
#endif
#include <impl/i18n.h>
#include <impl/framework.h>
#include <pgm/if.h>


//#define IF_DEBUG

/* temporary structure to contain interface name whilst address family
 * has not been resolved.
 */
struct interface_req {
	char			ir_name[IF_NAMESIZE];
	unsigned int		ir_flags;		/* from SIOCGIFFLAGS */
	unsigned int		ir_interface;		/* interface index */
	struct sockaddr_storage ir_addr;		/* interface address */
};


/* locals */

#ifndef _WIN32
#	define IF_DEFAULT_GROUP	((in_addr_t)0xefc00001) /* 239.192.0.1 */
#else
#	define IF_DEFAULT_GROUP	((u_long)0xefc00001)
#endif

/* ff08::1 */
#define IF6_DEFAULT_INIT { { { 0xff,8,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } }
const struct in6_addr if6_default_group_addr = IF6_DEFAULT_INIT;


static inline bool is_in_net (const struct in_addr*restrict, const struct in_addr*restrict, const struct in_addr*restrict) PGM_GNUC_WARN_UNUSED_RESULT;
static inline bool is_in_net6 (const struct in6_addr*restrict, const struct in6_addr*restrict, const struct in6_addr*restrict) PGM_GNUC_WARN_UNUSED_RESULT;
static inline bool is_network_char (const int, const char) PGM_GNUC_CONST;
static const char* pgm_family_string (const int) PGM_GNUC_CONST;


/* recommended address space for multicast:
 * rfc4607, rfc3180, rfc2365
 *
 * avoid 5 high-order bit overlap.
 *
 * loopback:  ffx1::/16
 * segment:   ffx2::/16
 * glop:      238/8
 * mysterious admin:  239/8,   ffx6::/16
 * site:      239.252-255/16,  ffx5::/16
 * org:       239.192/14,      ffx8::/16
 *
 * internets: 224.0.1.0-238.255.255.255,  ffxe::/16
 */


/* dump all interfaces to console.
 *
 * note that interface indexes are only in regard to the link layer and hence
 * no 1-1 mapping between adapter name to index back to address.
 */

void
pgm_if_print_all (void)
{
	struct pgm_ifaddrs_t *ifap, *ifa;

	if (!pgm_getifaddrs (&ifap, NULL))
		return;

	for (ifa = ifap; ifa; ifa = ifa->ifa_next)
	{
		const unsigned int i = NULL == ifa->ifa_addr ? 0 : pgm_if_nametoindex (ifa->ifa_addr->sa_family, ifa->ifa_name);
		char rname[IF_NAMESIZE * 2 + 3];
		char b[IF_NAMESIZE * 2 + 3];

		pgm_if_indextoname (i, rname);
		sprintf (b, "%s (%s)",
			ifa->ifa_name ? ifa->ifa_name : "(null)", rname);

		if (NULL == ifa->ifa_addr ||
		     (ifa->ifa_addr->sa_family != AF_INET && 
		      ifa->ifa_addr->sa_family != AF_INET6) )
		{
			pgm_info (_("#%d name %-15.15s ---- %-46.46s scope 0 status %s loop %s b/c %s m/c %s"),
				i,
				b,
				"",
			ifa->ifa_flags & IFF_UP ? "UP  " : "DOWN",
			ifa->ifa_flags & IFF_LOOPBACK ? "YES" : "NO ",
			ifa->ifa_flags & IFF_BROADCAST ? "YES" : "NO ",
			ifa->ifa_flags & IFF_MULTICAST ? "YES" : "NO "
			);
			continue;
		}

		char s[INET6_ADDRSTRLEN];
		getnameinfo (ifa->ifa_addr, pgm_sockaddr_len(ifa->ifa_addr),
			     s, sizeof(s),
			     NULL, 0,
			     NI_NUMERICHOST);
		pgm_info (_("#%d name %-15.15s IPv%i %-46.46s scope %u status %s loop %s b/c %s m/c %s"),
			i,
			b,
			ifa->ifa_addr->sa_family == AF_INET ? 4 : 6,
			s,
			(unsigned)pgm_sockaddr_scope_id(ifa->ifa_addr),
			ifa->ifa_flags & IFF_UP ? "UP  " : "DOWN",
			ifa->ifa_flags & IFF_LOOPBACK ? "YES" : "NO ",
			ifa->ifa_flags & IFF_BROADCAST ? "YES" : "NO ",
			ifa->ifa_flags & IFF_MULTICAST ? "YES" : "NO "
			);
	}

	pgm_freeifaddrs (ifap);
}

static inline
bool
is_in_net (
	const struct in_addr* restrict	addr,		/* host byte order */
	const struct in_addr* restrict	netaddr,
	const struct in_addr* restrict	netmask
	)
{
	pgm_assert (NULL != addr);
	pgm_assert (NULL != netaddr);
	pgm_assert (NULL != netmask);

#ifdef IF_DEBUG
	const struct in_addr taddr    = { .s_addr = htonl (addr->s_addr) };
	const struct in_addr tnetaddr = { .s_addr = htonl (netaddr->s_addr) };
	const struct in_addr tnetmask = { .s_addr = htonl (netmask->s_addr) };
	char saddr[INET_ADDRSTRLEN], snetaddr[INET_ADDRSTRLEN], snetmask[INET_ADDRSTRLEN];
	pgm_debug ("is_in_net (addr:%s netaddr:%s netmask:%s)",
		 pgm_inet_ntop (AF_INET, &taddr,    saddr,    sizeof(saddr)),
		 pgm_inet_ntop (AF_INET, &tnetaddr, snetaddr, sizeof(snetaddr)),
		 pgm_inet_ntop (AF_INET, &tnetmask, snetmask, sizeof(snetmask)));
#endif

	if ((addr->s_addr & netmask->s_addr) == (netaddr->s_addr & netmask->s_addr))
		return TRUE;
	return FALSE;
}

static
bool
is_in_net6 (
	const struct in6_addr* restrict	addr,
	const struct in6_addr* restrict	netaddr,
	const struct in6_addr* restrict	netmask
	)
{
	pgm_assert (NULL != addr);
	pgm_assert (NULL != netaddr);
	pgm_assert (NULL != netmask);

#ifdef IF_DEBUG
	char saddr[INET6_ADDRSTRLEN], snetaddr[INET6_ADDRSTRLEN], snetmask[INET6_ADDRSTRLEN];
	pgm_debug ("is_in_net6 (addr:%s netaddr:%s netmask:%s)",
		 pgm_inet_ntop (AF_INET6, addr, saddr, sizeof(saddr)),
		 pgm_inet_ntop (AF_INET6, netaddr, snetaddr, sizeof(snetaddr)),
		 pgm_inet_ntop (AF_INET6, netmask, snetmask, sizeof(snetmask)));
#endif

	for (unsigned i = 0; i < 16; i++)
		if ((addr->s6_addr[i] & netmask->s6_addr[i]) != (netaddr->s6_addr[i] & netmask->s6_addr[i]))
			return FALSE;
	return TRUE;
}

/* parse interface entity into an interface-request structure.
 *
 * e.g.  eth0
 *       1.2.3.4
 *       1.2
 *       abcd::
 *       [abcd::]
 *       <hostname>
 *       <nss network name>
 *
 * special addresses should be ignored:
 *
 * local physical link: 169.254.0.0/16, fe80::/64
 * broadcast: 255.255.255.255
 * multicast: 224.0.0.0/4 (224.0.0.0 to 239.255.255.255), ff00::/8
 *
 * We could use if_nametoindex() but we might as well check that the interface is
 * actually UP and capable of multicast traffic.
 *
 * returns TRUE on success, FALSE on error and sets error appropriately.
 */

static
bool
parse_interface (
	int				family,			/* AF_UNSPEC | AF_INET | AF_INET6 */
	const char*	      restrict	ifname,			/* NULL terminated */
	struct interface_req* restrict	ir,			/* location to write interface details to */
	pgm_error_t**	      restrict	error
	)
{
	bool check_inet_network = FALSE, check_inet6_network = FALSE;
	bool check_addr = FALSE;
	bool check_ifname = FALSE;
	char literal[1024];
	struct in_addr in_addr;
	struct in6_addr in6_addr;
	struct pgm_ifaddrs_t *ifap, *ifa;
	struct sockaddr_storage addr;
	unsigned interface_matches = 0;

/* pre-conditions */
	pgm_assert (AF_INET == family || AF_INET6 == family || AF_UNSPEC == family);
	pgm_assert (NULL != ifname);
	pgm_assert (NULL != ir);

	pgm_debug ("parse_interface (family:%s ifname:%s%s%s ir:%p error:%p)",
		pgm_family_string (family),
		ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "",
		(const void*)ir,
		(const void*)error);

/* strip any square brackets for IPv6 early evaluation */
	if (AF_INET != family &&
	    '[' == ifname[0])
	{
		const size_t ifnamelen = strlen(ifname);
		if (']' == ifname[ ifnamelen - 1 ]) {
			strncpy (literal, ifname + 1, ifnamelen - 2);
			literal[ ifnamelen - 2 ] = 0;
			family = AF_INET6;		/* force IPv6 evaluation */
			check_inet6_network = TRUE;	/* may be a network IP or CIDR block */
			check_addr = TRUE;		/* cannot be not a name */
			ifname = literal;
		}
	}

/* network address: in_addr in host byte order */
	if (AF_INET6 != family && 0 == pgm_inet_network (ifname, &in_addr))
	{
#ifdef IF_DEBUG
		struct in_addr t = { .s_addr = htonl (in_addr.s_addr) };
		pgm_debug ("IPv4 network address: %s", inet_ntoa (t));
#endif
		if (IN_MULTICAST(in_addr.s_addr)) {
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     PGM_ERROR_XDEV,
				     _("Expecting network interface address, found IPv4 multicast network %s%s%s"),
				     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
			return FALSE;
		}
		struct sockaddr_in s4;
		memset (&s4, 0, sizeof(s4));
		s4.sin_family = AF_INET;
		s4.sin_addr.s_addr = htonl (in_addr.s_addr);
		memcpy (&addr, &s4, sizeof(s4));

		check_inet_network = TRUE;
		check_addr = TRUE;
	}
	if (AF_INET  != family && 0 == pgm_inet6_network (ifname, &in6_addr))
	{
		if (IN6_IS_ADDR_MULTICAST(&in6_addr)) {
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     PGM_ERROR_XDEV,
				     _("Expecting network interface address, found IPv6 multicast network %s%s%s"),
				     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
			return FALSE;
		}
		struct sockaddr_in6 s6;
		memset (&s6, 0, sizeof(s6));
		s6.sin6_family = AF_INET6;
		s6.sin6_addr = in6_addr;
		memcpy (&addr, &s6, sizeof(s6));

		check_inet6_network = TRUE;
		check_addr = TRUE;
	}

/* numeric host with scope id */
	if (!check_addr)
	{
		struct addrinfo hints = {
			.ai_family	= family,
			.ai_socktype	= SOCK_STREAM,				/* not really, SOCK_RAW */
			.ai_protocol	= IPPROTO_TCP,				/* not really, IPPROTO_PGM */
			.ai_flags	= AI_ADDRCONFIG | AI_NUMERICHOST	/* AI_V4MAPPED is unhelpful */
		}, *res;
		const int eai = getaddrinfo (ifname, NULL, &hints, &res);
		switch (eai) {
		case 0:
			if (AF_INET == res->ai_family &&
			    IN_MULTICAST(ntohl (((struct sockaddr_in*)(res->ai_addr))->sin_addr.s_addr)))
			{
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_XDEV,
					     _("Expecting interface address, found IPv4 multicast address %s%s%s"),
					     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
				freeaddrinfo (res);
				return FALSE;
			}
			else if (AF_INET6 == res->ai_family &&
				 IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6*)res->ai_addr)->sin6_addr))
			{
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_XDEV,
					     _("Expecting interface address, found IPv6 multicast address %s%s%s"),
					     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
				freeaddrinfo (res);
				return FALSE;
			}

			memcpy (&addr, res->ai_addr, pgm_sockaddr_len (res->ai_addr));
			freeaddrinfo (res);
			check_addr = TRUE;
			break;

#if defined(EAI_NODATA) && EAI_NODATA != EAI_NONAME
		case EAI_NODATA:
#endif
		case EAI_NONAME:
			break;

		default:
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     pgm_error_from_eai_errno (eai, errno),
				     _("Numeric host resolution: %s"),
				     gai_strerror (eai));
			return FALSE;
		}
	}

#ifndef _WIN32
/* network name into network address, can be expensive with NSS network lookup
 *
 * Only Class A, B or C networks are supported, partitioned networks
 * (i.e. network/26 or network/28) are not supported by this facility.
 */
	if (!(check_inet_network || check_inet6_network))
	{
		const struct netent* ne = getnetbyname (ifname);
/* ne::n_net in host byte order */

		if (ne) {
			switch (ne->n_addrtype) {
			case AF_INET:
				if (AF_INET6 == family) {
					pgm_set_error (error,
						     PGM_ERROR_DOMAIN_IF,
						     PGM_ERROR_NODEV,
						     _("IP address family conflict when resolving network name %s%s%s, found AF_INET when AF_INET6 expected."),
						     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
					return FALSE;
				}
/* ne->n_net in network order */
				in_addr.s_addr = ne->n_net;
				if (IN_MULTICAST(in_addr.s_addr)) {
					pgm_set_error (error,
						     PGM_ERROR_DOMAIN_IF,
						     PGM_ERROR_XDEV,
						     _("Network name %s%s%s resolves to IPv4 mulicast address."),
						     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
					return FALSE;
				}
				check_inet_network = TRUE;
				break;
			case AF_INET6:
#ifndef CONFIG_HAVE_IP6_NETWORKS
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_NODEV,
					     _("Not configured for IPv6 network name support, %s%s%s is an IPv6 network name."),
					     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
				return FALSE;
#else
				if (AF_INET == family) {
					pgm_set_error (error,
						     PGM_ERROR_DOMAIN_IF,
						     PGM_ERROR_NODEV,
						     _("IP address family conflict when resolving network name %s%s%s, found AF_INET6 when AF_INET expected."),
						     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
					return FALSE;
				}
				if (IN6_IS_ADDR_MULTICAST(&ne->n_net)) {
					pgm_set_error (error,
						     PGM_ERROR_DOMAIN_IF,
						     PGM_ERROR_XDEV,
						     _("Network name resolves to IPv6 mulicast address %s%s%s"),
						     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
					return FALSE;
				}
				in6_addr = *(const struct in6_addr*)&ne->n_net;
				check_inet6_network = TRUE;
				break;
#endif
			default:
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_NODEV,
					     _("Network name resolves to non-internet protocol address family %s%s%s"),
					     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
				return FALSE;
			}
		}
	}
#endif /* _WIN32 */

/* hostname lookup with potential DNS delay or error */
	if (!check_addr)
	{
		struct addrinfo hints = {
			.ai_family	= family,
			.ai_socktype	= SOCK_STREAM,		/* not really, SOCK_RAW */
			.ai_protocol	= IPPROTO_TCP,		/* not really, IPPROTO_PGM */
			.ai_flags	= AI_ADDRCONFIG,	/* AI_V4MAPPED is unhelpful */
		}, *res;

		const int eai = getaddrinfo (ifname, NULL, &hints, &res);
		switch (eai) {
		case 0:
			if (AF_INET == res->ai_family &&
			    IN_MULTICAST(ntohl (((struct sockaddr_in*)(res->ai_addr))->sin_addr.s_addr)))
			{
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_XDEV,
					     _("Expecting interface address, found IPv4 multicast name %s%s%s"),
					     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
				freeaddrinfo (res);
				return FALSE;
			}
			else if (AF_INET6 == res->ai_family &&
				 IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6*)res->ai_addr)->sin6_addr))
			{
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_XDEV,
					     _("Expecting interface address, found IPv6 multicast name %s%s%s"),
					     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
				freeaddrinfo (res);
				return FALSE;
			}
			memcpy (&addr, res->ai_addr, pgm_sockaddr_len (res->ai_addr));
			freeaddrinfo (res);
			check_addr = TRUE;
			break;

#if defined(EAI_NODATA) && EAI_NODATA != EAI_NONAME
		case EAI_NODATA:
#endif
		case EAI_NONAME:
			check_ifname = TRUE;
			break;

		default:
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     pgm_error_from_eai_errno (eai, errno),
				     _("Internet host resolution: %s(%d)"),
				     gai_strerror (eai), eai);
			return FALSE;
		}
	}

/* iterate through interface list and match device name, ip or net address */
	if (!pgm_getifaddrs (&ifap, error)) {
		pgm_prefix_error (error,
				_("Enumerating network interfaces: "));
		return FALSE;
	}

	for (ifa = ifap; ifa; ifa = ifa->ifa_next)
	{
		if (NULL == ifa->ifa_addr)
			continue;

		switch (ifa->ifa_addr->sa_family) {
/* ignore raw entries on Linux */
#ifdef AF_PACKET
		case AF_PACKET:
			continue;
#endif
		case AF_INET:
			if (AF_INET6 == family)
				continue;
			break;
		case AF_INET6:
			if (AF_INET == family)
				continue;
			break;
		default:
			continue;
		}

		const unsigned ifindex = pgm_if_nametoindex (ifa->ifa_addr->sa_family, ifa->ifa_name);
		pgm_assert (0 != ifindex);

/* check numeric host */
		if (check_addr &&
		    (0 == pgm_sockaddr_cmp (ifa->ifa_addr, (const struct sockaddr*)&addr)))
		{
			strcpy (ir->ir_name, ifa->ifa_name);
			ir->ir_flags = ifa->ifa_flags;
			if (ir->ir_flags & IFF_LOOPBACK)
				pgm_warn (_("Interface %s reports as a loopback device."), ir->ir_name);
			if (!(ir->ir_flags & IFF_MULTICAST))
				pgm_warn (_("Interface %s reports as a non-multicast capable device."), ir->ir_name);
			ir->ir_interface = ifindex;
			memcpy (&ir->ir_addr, ifa->ifa_addr, pgm_sockaddr_len (ifa->ifa_addr));
			pgm_freeifaddrs (ifap);
			return TRUE;
		}

/* check network address */
		if (check_inet_network &&
		    AF_INET == ifa->ifa_addr->sa_family)
		{
			const struct in_addr ifaddr  = { .s_addr = ntohl (((struct sockaddr_in*)ifa->ifa_addr)->sin_addr.s_addr) };
			const struct in_addr netmask = { .s_addr = ntohl (((struct sockaddr_in*)ifa->ifa_netmask)->sin_addr.s_addr) };
			if (is_in_net (&ifaddr, &in_addr, &netmask)) {
				strcpy (ir->ir_name, ifa->ifa_name);
				ir->ir_flags = ifa->ifa_flags;
				if (ir->ir_flags & IFF_LOOPBACK) {
					pgm_warn (_("Skipping matching loopback network device %s."), ir->ir_name);
					goto skip_inet_network;
				}
				if (!(ir->ir_flags & IFF_MULTICAST)) {
					pgm_warn (_("Skipping matching non-multicast capable network device %s."), ir->ir_name);
					goto skip_inet_network;
				}
				ir->ir_interface = ifindex;
				memcpy (&ir->ir_addr, ifa->ifa_addr, pgm_sockaddr_len (ifa->ifa_addr));
				pgm_freeifaddrs (ifap);
				return TRUE;
			}
		}
		if (check_inet6_network &&
		    AF_INET6 == ifa->ifa_addr->sa_family)
		{
			const struct in6_addr ifaddr = ((struct sockaddr_in6*)ifa->ifa_addr)->sin6_addr;
			const struct in6_addr netmask = ((struct sockaddr_in6*)ifa->ifa_netmask)->sin6_addr;
			if (is_in_net6 (&ifaddr, &in6_addr, &netmask)) {
				strcpy (ir->ir_name, ifa->ifa_name);
				ir->ir_flags = ifa->ifa_flags;
				if (ir->ir_flags & IFF_LOOPBACK) {
					pgm_warn (_("Skipping matching loopback network device %s."), ir->ir_name);
					goto skip_inet_network;
				}
				if (!(ir->ir_flags & IFF_MULTICAST)) {
					pgm_warn (_("Skipping matching non-multicast capable network device %s."), ir->ir_name);
					goto skip_inet_network;
				}
				ir->ir_interface = ifindex;
				memcpy (&ir->ir_addr, ifa->ifa_addr, pgm_sockaddr_len (ifa->ifa_addr));
				pgm_freeifaddrs (ifap);
				return TRUE;
			}
		}
skip_inet_network:

/* check interface name */
		if (check_ifname)
		{
			if (0 != strcmp (ifname, ifa->ifa_name))
				continue;

			ir->ir_flags = ifa->ifa_flags;
/* skip loopback and non-multicast capable devices */
			if ((ir->ir_flags & IFF_LOOPBACK) || !(ir->ir_flags & IFF_MULTICAST))
				continue;

/* check for multiple interfaces */
			if (interface_matches++) {
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_NOTUNIQ,
					     _("Network interface name not unique %s%s%s"),
					     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
				pgm_freeifaddrs (ifap);
				return FALSE;
			}

			ir->ir_interface = ifindex;
			strcpy (ir->ir_name, ifa->ifa_name);
			memcpy (&ir->ir_addr, ifa->ifa_addr, pgm_sockaddr_len (ifa->ifa_addr));
			continue;
		}

	}

	if (0 == interface_matches) {
		pgm_set_error (error,
			     PGM_ERROR_DOMAIN_IF,
			     PGM_ERROR_NODEV,
			     _("No matching non-loopback and multicast capable network interface %s%s%s"),
			     ifname ? "\"" : "", ifname ? ifname : "(null)", ifname ? "\"" : "");
		pgm_freeifaddrs (ifap);
		return FALSE;
	}

	pgm_freeifaddrs (ifap);
	return TRUE;
}

/* parse one multicast address, conflict resolution of multiple address families of DNS multicast names is
 * deferred to libc.
 *
 * Zone indices are ignored as interface specification is already available.
 *
 * reserved addresses may flag warnings:
 *
 * 224.0.0.0/24 for local network control
 * 224.0.1/24 for internetwork control
 * 169.254.255.255, ff02::1 all local nodes on segment
 * ff02::2 all routers
 * ff05::1 all nodes
 * ff0x::fb multicast DNS
 * ff0x::108 NIS
 * ff05::1:3 DHCP
 *
 * returns TRUE on success, FALSE on error and sets error appropriately.
 */

static
bool
parse_group (
	const int		  family,	/* AF_UNSPEC | AF_INET | AF_INET6 */
	const char*	 restrict group,	/* NULL terminated */
	struct sockaddr* restrict addr,		/* pointer to sockaddr_storage for writing */
	pgm_error_t**	 restrict error
	)
{
/* pre-conditions */
	pgm_assert (AF_INET == family || AF_INET6 == family || AF_UNSPEC == family);
	pgm_assert (NULL != group);
	pgm_assert (NULL != addr);

	pgm_debug ("parse_group (family:%s group:%s%s%s addr:%p error:%p)",
		pgm_family_string (family),
		group ? "\"" : "", group ? group : "(null)", group ? "\"" : "",
		(const void*)addr,
		(const void*)error);

/* strip any square brackets for early IPv6 literal evaluation */
	if (AF_INET != family &&
	    '[' == group[0])
	{
		const size_t grouplen = strlen(group);
		if (']' == group[ grouplen - 1 ]) {
			char literal[1024];
			strncpy (literal, group + 1, grouplen - 2);
			literal[ grouplen - 2 ] = 0;
			if (pgm_inet_pton (AF_INET6, literal, &((struct sockaddr_in6*)addr)->sin6_addr) &&
			    IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6*)addr)->sin6_addr))
			{
				addr->sa_family = AF_INET6;
				((struct sockaddr_in6*)addr)->sin6_port = 0;
				((struct sockaddr_in6*)addr)->sin6_flowinfo = 0;
				((struct sockaddr_in6*)addr)->sin6_scope_id = 0;
				return TRUE;
			}
		}
	}

/* IPv4 address */
	if (AF_INET6 != family &&
	    pgm_inet_pton (AF_INET, group, &((struct sockaddr_in*)addr)->sin_addr) &&
	    IN_MULTICAST(ntohl (((struct sockaddr_in*)addr)->sin_addr.s_addr)))
	{
		addr->sa_family = AF_INET;
		return TRUE;
	}
	if (AF_INET  != family &&
	    pgm_inet_pton (AF_INET6, group, &((struct sockaddr_in6*)addr)->sin6_addr) &&
	    IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6*)addr)->sin6_addr))
	{
		addr->sa_family = AF_INET6;
		((struct sockaddr_in6*)addr)->sin6_port = 0;
		((struct sockaddr_in6*)addr)->sin6_flowinfo = 0;
		((struct sockaddr_in6*)addr)->sin6_scope_id = 0;
		return TRUE;
	}

#ifndef _WIN32
/* NSS network */
	const struct netent* ne = getnetbyname (group);
/* ne::n_net in host byte order */
	if (ne) {
		switch (ne->n_addrtype) {
		case AF_INET:
			if (AF_INET6 == family) {
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_NODEV,
					     _("IP address family conflict when resolving network name %s%s%s, found IPv4 when IPv6 expected."),
					     group ? "\"" : "", group ? group : "(null)", group ? "\"" : "");
				return FALSE;
			}
			if (IN_MULTICAST(ne->n_net)) {
				addr->sa_family = AF_INET;
				((struct sockaddr_in*)addr)->sin_addr.s_addr = htonl (ne->n_net);
				return TRUE;
			}
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     PGM_ERROR_NODEV,
				     _("IP address class conflict when resolving network name %s%s%s, expected IPv4 multicast."),
				     group ? "\"" : "", group ? group : "(null)", group ? "\"" : "");
			return FALSE;
		case AF_INET6:
#ifndef CONFIG_HAVE_IP6_NETWORKS
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     PGM_ERROR_NODEV,
				     _("Not configured for IPv6 network name support, %s%s%s is an IPv6 network name."),
				     group ? "\"" : "", group ? group : "(null)", group ? "\"" : "");
			return FALSE;
#else
			if (AF_INET == family) {
				pgm_set_error (error,
					     PGM_ERROR_DOMAIN_IF,
					     PGM_ERROR_NODEV,
					     _("IP address family conflict when resolving network name %s%s%s, found IPv6 when IPv4 expected."),
					     group ? "\"" : "", group ? group : "(null)", group ? "\"" : "");
				return FALSE;
			}
			if (IN6_IS_ADDR_MULTICAST(&ne->n_net)) {
				addr->sa_family = AF_INET6;
				((struct sockaddr_in6*)addr)->sin6_addr = *(const struct in6_addr*)ne->n_net;
				((struct sockaddr_in6*)&addr)->sin6_port = 0;
				((struct sockaddr_in6*)&addr)->sin6_flowinfo = 0;
				((struct sockaddr_in6*)&addr)->sin6_scope_id = 0;
				return TRUE;
			}
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     PGM_ERROR_NODEV,
				     _("IP address class conflict when resolving network name %s%s%s, expected IPv6 multicast."),
				     group ? "\"" : "", group ? group : "(null)", group ? "\"" : "");
			return FALSE;
#endif /* CONFIG_HAVE_IP6_NETWORKS */
		default:
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     PGM_ERROR_NODEV,
				     _("Network name resolves to non-internet protocol address family %s%s%s"),
				     group ? "\"" : "", group ? group : "(null)", group ? "\"" : "");
			return FALSE;
		}
	}
#endif /* _WIN32 */

/* lookup group through name service */
	struct addrinfo hints = {
		.ai_family	= family,
		.ai_socktype	= SOCK_STREAM,		/* not really, SOCK_RAW */
		.ai_protocol	= IPPROTO_TCP,		/* not really, IPPROTO_PGM */
		.ai_flags	= AI_ADDRCONFIG,	/* AI_V4MAPPED is unhelpful */
	}, *res;

	const int eai = getaddrinfo (group, NULL, &hints, &res);
	if (0 != eai) {
		pgm_set_error (error,
			     PGM_ERROR_DOMAIN_IF,
			     pgm_error_from_eai_errno (eai, errno),
			     _("Resolving receive group: %s"),
			     gai_strerror (eai));
		return FALSE;
	}

	if ((AF_INET6 != family && IN_MULTICAST(ntohl (((struct sockaddr_in*)res->ai_addr)->sin_addr.s_addr))) ||
	    (AF_INET  != family && IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6*)res->ai_addr)->sin6_addr)))
	{
		memcpy (addr, res->ai_addr, res->ai_addrlen);
		freeaddrinfo (res);
		return TRUE;
	}

	pgm_set_error (error,
		     PGM_ERROR_DOMAIN_IF,
		     PGM_ERROR_INVAL,
		     _("Unresolvable receive group %s%s%s"),
		     group ? "\"" : "", group ? group : "(null)", group ? "\"" : "");
	freeaddrinfo (res);
	return FALSE;
}

/* parse an interface entity from a network parameter.
 *
 * family can be unspecified - AF_UNSPEC, can return interfaces with the unspecified
 * address family
 *
 * examples:  "eth0"
 * 	      "hme0,hme1"
 * 	      "qe0,qe1,qe2"
 * 	      "qe0,qe2,qe2"	=> valid even though duplicate interface name
 *
 * returns TRUE on success with device_list containing double linked list of devices as
 * sockaddr/idx pairs.  returns FALSE on error, including multiple matching adapters.
 *
 * memory ownership of linked list is passed to caller and must be freed with pgm_free
 * and the pgm_list_free* api.
 */

static
bool
parse_interface_entity (
	int			family,	/* AF_UNSPEC | AF_INET | AF_INET6 */
	const char*   restrict	entity,	/* NULL terminated */
	pgm_list_t**  restrict	interface_list,	/* <struct interface_req*> */
	pgm_error_t** restrict	error
	)
{
	struct interface_req* ir;
	pgm_list_t* source_list = NULL;

/* pre-conditions */
	pgm_assert (AF_INET == family || AF_INET6 == family || AF_UNSPEC == family);
	pgm_assert (NULL != interface_list);
	pgm_assert (NULL == *interface_list);
	pgm_assert (NULL != error);

	pgm_debug ("parse_interface_entity (family:%s entity:%s%s%s interface_list:%p error:%p)",
		pgm_family_string (family),
		entity ? "\"":"", entity ? entity : "(null)", entity ? "\"":"",
		(const void*)interface_list,
		(const void*)error);

/* the empty entity, returns in_addr_any for both receive and send interfaces */
	if (NULL == entity)
	{
		ir = pgm_new0 (struct interface_req, 1);
		ir->ir_addr.ss_family = family;
		*interface_list = pgm_list_append (*interface_list, ir);
		return TRUE;
	}

/* check interface name length limit */
	char** tokens = pgm_strsplit (entity, ",", 10);
	int j = 0;
	while (tokens && tokens[j])
	{
		pgm_error_t* sub_error = NULL;
		ir = pgm_new (struct interface_req, 1);
		if (!parse_interface (family, tokens[j], ir, &sub_error))
		{
/* mark multiple interfaces for later decision based on group families */
			if (sub_error && PGM_ERROR_NOTUNIQ == sub_error->code)
			{
				ir->ir_addr.ss_family = AF_UNSPEC;
				pgm_error_free (sub_error);
			}
/* bail out on first interface with an error */
			else
			{
				pgm_propagate_error (error, sub_error);
				pgm_free (ir);
				pgm_strfreev (tokens);
				while (source_list) {
					pgm_free (source_list->data);
					source_list = pgm_list_delete_link (source_list, source_list);
				}
				return FALSE;
			}
		}

		source_list = pgm_list_append (source_list, ir);
		++j;
	}

	pgm_strfreev (tokens);
	*interface_list = source_list;
	return TRUE;
}

/* parse a receive multicast group entity.  can contain more than one multicast group to
 * support asymmetric fan-out.
 *
 * if group is ambiguous, i.e. empty or a name mapping then the address family of the matching
 * interface is queried.  if the interface is also ambiguous, i.e. empty interface and receive group
 * then the hostname will be used to determine the default node address family.  if the hosts
 * node name resolves both IPv4 and IPv6 address families then the first matching value is taken.
 *
 * e.g. "239.192.0.1"
 * 	"239.192.0.100,239.192.0.101"
 *
 * unspecified address family interfaces are forced to AF_INET or AF_INET6.
 *
 * returns TRUE on success, returns FALSE on error and sets error appropriately.
 */

static
bool
parse_receive_entity (
	int			family,		/* AF_UNSPEC | AF_INET | AF_INET6 */
	const char*   restrict	entity,		/* NULL terminated */
	pgm_list_t**  restrict	interface_list,	/* <struct interface_req*> */
	pgm_list_t**  restrict	recv_list,	/* <struct group_source_req*> */
	pgm_error_t** restrict	error
	)
{
/* pre-conditions */
	pgm_assert (AF_INET == family || AF_INET6 == family || AF_UNSPEC == family);
	pgm_assert (NULL != recv_list);
	pgm_assert (NULL == *recv_list);
	pgm_assert (NULL != error);

	pgm_debug ("parse_receive_entity (family:%s entity:%s%s%s interface_list:%p recv_list:%p error:%p)",
		pgm_family_string (family),
		entity ? "\"":"", entity ? entity : "(null)", entity ? "\"":"",
		(const void*)interface_list,
		(const void*)recv_list,
		(const void*)error);

	struct group_source_req* recv_gsr;
	struct interface_req* primary_interface = (struct interface_req*)pgm_memdup ((*interface_list)->data, sizeof(struct interface_req));

/* the empty entity */
	if (NULL == entity)
	{
/* default receive object */
		recv_gsr = pgm_new0 (struct group_source_req, 1);
		recv_gsr->gsr_interface = primary_interface->ir_interface;
		recv_gsr->gsr_group.ss_family = family;

/* track IPv6 scope from any resolved interface */
		unsigned scope_id = 0;

/* if using unspec default group check the interface for address family
 */
		if (AF_UNSPEC == recv_gsr->gsr_group.ss_family)
		{
			if (AF_UNSPEC == primary_interface->ir_addr.ss_family)
			{
				struct sockaddr_storage addr;
				if (!pgm_if_getnodeaddr (AF_UNSPEC, (struct sockaddr*)&addr, sizeof(addr), error))
				{
					pgm_prefix_error (error,
							_("Node primary address family cannot be determined: "));
					pgm_free (recv_gsr);
					pgm_free (primary_interface);
					return FALSE;
				}
				recv_gsr->gsr_group.ss_family = addr.ss_family;
				scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&addr);

/* was an interface actually specified */
				if (primary_interface->ir_name[0] != '\0')
				{
					struct interface_req ir;
					if (!parse_interface (recv_gsr->gsr_group.ss_family, primary_interface->ir_name, &ir, error))
					{
						pgm_prefix_error (error,
								_("Unique address cannot be determined for interface %s%s%s: "),
								primary_interface->ir_name ? "\"" : "", primary_interface->ir_name ? primary_interface->ir_name : "(null)", primary_interface->ir_name ? "\"" : "");
						pgm_free (recv_gsr);
						pgm_free (primary_interface);
						return FALSE;
					}

					recv_gsr->gsr_interface = ir.ir_interface;
					memcpy (&primary_interface->ir_addr, &ir.ir_addr, pgm_sockaddr_len ((struct sockaddr*)&ir.ir_addr));
					scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&ir.ir_addr);
				}
			}
			else
			{
/* use interface address family for multicast group */
				recv_gsr->gsr_group.ss_family = primary_interface->ir_addr.ss_family;
				scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&primary_interface->ir_addr);
			}
		}


		pgm_assert (AF_UNSPEC != recv_gsr->gsr_group.ss_family);
		if (AF_UNSPEC != primary_interface->ir_addr.ss_family)
		{
			pgm_assert (recv_gsr->gsr_group.ss_family == primary_interface->ir_addr.ss_family);
		}
		else
		{
/* check if we can now resolve the interface by address family of the receive group */
			if (primary_interface->ir_name[0] != '\0')
			{
				struct interface_req ir;
				if (!parse_interface (recv_gsr->gsr_group.ss_family, primary_interface->ir_name, &ir, error))
				{
					pgm_prefix_error (error,
							_("Unique address cannot be determined for interface %s%s%s: "),
							primary_interface->ir_name ? "\"" : "", primary_interface->ir_name ? primary_interface->ir_name : "(null)", primary_interface->ir_name ? "\"" : "");
					pgm_free (recv_gsr);
					pgm_free (primary_interface);
					return FALSE;
				}

				recv_gsr->gsr_interface = ir.ir_interface;
				scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&ir.ir_addr);
			}
		}

/* copy default PGM multicast group */
		switch (recv_gsr->gsr_group.ss_family) {
		case AF_INET6:
			memcpy (&((struct sockaddr_in6*)&recv_gsr->gsr_group)->sin6_addr,
				&if6_default_group_addr,
				sizeof(if6_default_group_addr));
			((struct sockaddr_in6*)&recv_gsr->gsr_group)->sin6_scope_id = scope_id;
			break;

		case AF_INET:
			((struct sockaddr_in*)&recv_gsr->gsr_group)->sin_addr.s_addr = htonl(IF_DEFAULT_GROUP);
			break;
	
		default:
			pgm_assert_not_reached();
		}

/* ASM: source = group */
		memcpy (&recv_gsr->gsr_source, &recv_gsr->gsr_group, pgm_sockaddr_len ((struct sockaddr*)&recv_gsr->gsr_group));
		*recv_list = pgm_list_append (*recv_list, recv_gsr);
		pgm_free (primary_interface);
		return TRUE;
	}

/* parse one or more multicast receive groups.
 */

	int j = 0;	
	char** tokens = pgm_strsplit (entity, ",", 10);
	while (tokens && tokens[j])
	{
/* default receive object */
		recv_gsr = pgm_new0 (struct group_source_req, 1);
		recv_gsr->gsr_interface = primary_interface->ir_interface;
		recv_gsr->gsr_group.ss_family = family;

		if (AF_UNSPEC == recv_gsr->gsr_group.ss_family)
		{
			if (AF_UNSPEC == primary_interface->ir_addr.ss_family)
			{
				pgm_debug ("Address family of receive group cannot be determined from interface.");
			}
			else
			{
				recv_gsr->gsr_group.ss_family = primary_interface->ir_addr.ss_family;
				((struct sockaddr_in6*)&recv_gsr->gsr_group)->sin6_scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&primary_interface->ir_addr);
			}
		}

		if (!parse_group (recv_gsr->gsr_group.ss_family, tokens[j], (struct sockaddr*)&recv_gsr->gsr_group, error))
		{
			pgm_prefix_error (error,
					_("Unresolvable receive entity %s%s%s: "),
					tokens[j] ? "\"" : "", tokens[j] ? tokens[j] : "(null)", tokens[j] ? "\"" : "");
			pgm_free (recv_gsr);
			pgm_strfreev (tokens);
			pgm_free (primary_interface);
			return FALSE;
		}

/* check if we can now resolve the source interface by address family of the receive group */
		if (AF_UNSPEC == primary_interface->ir_addr.ss_family)
		{
			if (primary_interface->ir_name[0] != '\0')
			{
				struct interface_req ir;
				if (!parse_interface (recv_gsr->gsr_group.ss_family, primary_interface->ir_name, &ir, error))
				{
					pgm_prefix_error (error,
							_("Unique address cannot be determined for interface %s%s%s: "),
							primary_interface->ir_name ? "\"" : "", primary_interface->ir_name ? primary_interface->ir_name : "(null)", primary_interface->ir_name ? "\"" : "");
					pgm_free (recv_gsr);
					pgm_free (primary_interface);
					return FALSE;
				}

				recv_gsr->gsr_interface = ir.ir_interface;
				((struct sockaddr_in6*)&recv_gsr->gsr_group)->sin6_scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&ir.ir_addr);
			}
		}
		else
		{
/* keep interface scope */
			((struct sockaddr_in6*)&recv_gsr->gsr_group)->sin6_scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&primary_interface->ir_addr);
		}

/* ASM: source = group */
		memcpy (&recv_gsr->gsr_source, &recv_gsr->gsr_group, pgm_sockaddr_len ((struct sockaddr*)&recv_gsr->gsr_group));
		*recv_list = pgm_list_append (*recv_list, recv_gsr);
		++j;
	}

	pgm_strfreev (tokens);
	pgm_free (primary_interface);
	return TRUE;
}

static
bool
parse_send_entity (
	int			family,		/* AF_UNSPEC | AF_INET | AF_INET6 */
	const char*   restrict	entity,		/* null = empty entity */
	pgm_list_t**  restrict	interface_list,	/* <struct interface_req*> */
	pgm_list_t**  restrict	recv_list,	/* <struct group_source_req*> */
	pgm_list_t**  restrict	send_list,	/* <struct group_source_req*> */
	pgm_error_t** restrict	error
	)
{
/* pre-conditions */
	pgm_assert (AF_INET == family || AF_INET6 == family || AF_UNSPEC == family);
	pgm_assert (NULL != recv_list);
	pgm_assert (NULL != *recv_list);
	pgm_assert (NULL != send_list);
	pgm_assert (NULL == *send_list);
	pgm_assert (NULL != error);

	pgm_debug ("parse_send_entity (family:%s entity:%s%s%s interface_list:%p recv_list:%p send_list:%p error:%p)",
		pgm_family_string (family),
		entity ? "\"":"", entity ? entity : "(null)", entity ? "\"":"",
		(const void*)interface_list,
		(const void*)recv_list,
		(const void*)send_list,
		(const void*)error);

	struct group_source_req* send_gsr;
	const struct interface_req* primary_interface = (struct interface_req*)(*interface_list)->data;

	if (entity == NULL)
	{
		send_gsr = pgm_memdup ((*recv_list)->data, sizeof(struct group_source_req));
		*send_list = pgm_list_append (*send_list, send_gsr);
		return TRUE;
	}

/* default send object */
	send_gsr = pgm_new0 (struct group_source_req, 1);
	send_gsr->gsr_interface = primary_interface->ir_interface;
	if (!parse_group (family, entity, (struct sockaddr*)&send_gsr->gsr_group, error))
	{
		pgm_prefix_error (error,
				_("Unresolvable send entity %s%s%s: "),
				entity ? "\"":"", entity ? entity : "(null)", entity ? "\"":"");
		pgm_free (send_gsr);
		return FALSE;
	}

/* check if we can now resolve the source interface by address family of the send group */
	if (AF_UNSPEC == primary_interface->ir_addr.ss_family)
	{
		if (primary_interface->ir_name[0] != '\0')
		{
			struct interface_req ir;
			if (!parse_interface (send_gsr->gsr_group.ss_family, primary_interface->ir_name, &ir, error))
			{
				pgm_prefix_error (error,
						_("Unique address cannot be determined for interface %s%s%s: "),
						primary_interface->ir_name ? "\"":"", primary_interface->ir_name ? primary_interface->ir_name : "(null)", primary_interface->ir_name ? "\"":"");
				pgm_free (send_gsr);
				return FALSE;
			}

			send_gsr->gsr_interface = ir.ir_interface;
			((struct sockaddr_in6*)&send_gsr->gsr_group)->sin6_scope_id = pgm_sockaddr_scope_id ((struct sockaddr*)&ir.ir_addr);
		}
	}

/* ASM: source = group */
	memcpy (&send_gsr->gsr_source, &send_gsr->gsr_group, pgm_sockaddr_len ((struct sockaddr*)&send_gsr->gsr_group));
	*send_list = pgm_list_append (*send_list, send_gsr);
	return TRUE;
}

/* parse network parameter
 *
 * interface list; receive multicast group list; send multicast group
 */

#define IS_HOSTNAME(x) ( 				/* RFC 952 */ \
				isalnum(x) || \
				((x) == '-') || \
				((x) == '.') \
			)
#define IS_IP(x) ( \
				isdigit(x) || \
				((x) == '.') || \
				((x) == '/') \
			)
#define IS_IP6(x) ( \
				isxdigit(x) || \
				((x) == ':') || \
				((x) == '/') || \
				((x) == '.') || \
				((x) == '[') || \
				((x) == ']') \
			)
/* e.g. fe80::1%eth0.620    vlan tag,
 *      fe80::1%eth0:0      IP alias
 *      fe80::1%qe0_0       Solaris link name
 *
 * The Linux kernel generally doesn't care too much, but everything else falls apart with
 * random characters in interface names.  Hyphen is a popular problematic character.
 */
#define IS_IP6_WITH_ZONE(x) ( \
				IS_IP6(x) || \
				((x) == '%') || \
				isalpha(x) || \
				((x) == '_') \
			    )
#define IS_NETPARAM(x) ( \
				((x) == ',') || \
				((x) == ';') \
			)

static inline
bool
is_network_char (
	const int		family,
	const char		c
	)
{
	if (IS_HOSTNAME(c) ||
	    (AF_INET == family && IS_IP(c)) ||
	    ((AF_INET6 == family || AF_UNSPEC == family) && IS_IP6_WITH_ZONE(c)) ||
	    IS_NETPARAM(c))
		return TRUE;
	else
		return FALSE;
}

static
bool
network_parse (
	const char*   restrict	network,		/* NULL terminated */
	int			family,			/* AF_UNSPEC | AF_INET | AF_INET6 */
	pgm_list_t**  restrict	recv_list,		/* <struct group_source_req*> */
	pgm_list_t**  restrict	send_list,		/* <struct group_source_req*> */
	pgm_error_t** restrict	error
	)
{
	bool retval = FALSE;
	const char *p = network;
	const char *e = p + strlen(network);
	enum { ENTITY_INTERFACE, ENTITY_RECEIVE, ENTITY_SEND, ENTITY_ERROR } ec = ENTITY_INTERFACE;
	const char *b = p;		/* begin of entity */
	pgm_list_t* source_list = NULL;
	pgm_error_t* sub_error = NULL;

/* pre-conditions */
	pgm_assert (NULL != network);
	pgm_assert (AF_UNSPEC == family || AF_INET == family || AF_INET6 == family);
	pgm_assert (NULL != recv_list);
	pgm_assert (NULL != send_list);

	pgm_debug ("network_parse (network:%s%s%s family:%s recv_list:%p send_list:%p error:%p)",
		network ? "\"" : "", network ? network : "(null)", network ? "\"" : "",
		pgm_family_string (family),
		(const void*)recv_list,
		(const void*)send_list,
		(const void*)error);

	while (p < e)
	{
		if (!is_network_char (family, *p))
		{
			pgm_set_error (error,
				     PGM_ERROR_DOMAIN_IF,
				     PGM_ERROR_INVAL,
				     _("'%c' is not a valid character."),
				     *p);
			goto free_lists;
		}

		if (*p == ';')		/* end of entity */
		{
			if (b == p)	/* empty entity */
			{
				switch (ec++) {
				case ENTITY_INTERFACE:
					retval = parse_interface_entity (family, NULL, &source_list, error);
					break;

				case ENTITY_RECEIVE:
					retval = parse_receive_entity (family, NULL, &source_list, recv_list, error);
					break;

				case ENTITY_SEND:
					retval = parse_send_entity (family, NULL, &source_list, recv_list, send_list, error);
					break;

				default:
					pgm_assert_not_reached();
					break;
				}

				if (!retval)
					goto free_lists;

				b = ++p;
				continue;
			}

/* entity from b to p-1 */
			char entity[1024];
			strncpy (entity, b, sizeof(entity));
			entity[p - b] = 0;

			switch (ec++) {
			case ENTITY_INTERFACE:
				if (parse_interface_entity (family, entity, &source_list, &sub_error))
					break;
				if (!(sub_error && PGM_ERROR_XDEV == sub_error->code))
				{
/* fall through on multicast */
					if (!(sub_error && PGM_ERROR_NOTUNIQ == sub_error->code))
					{
						pgm_propagate_error (error, sub_error);
						goto free_lists;
					}
					pgm_clear_error (&sub_error);
/* FIXME: too many interfaces */
					if (pgm_list_length (source_list) > 1) {
						pgm_set_error (error,
				   			     PGM_ERROR_DOMAIN_IF,
							     PGM_ERROR_INVAL,
							     _("Send group list contains more than one entity."));
						goto free_lists;
					}
					break;
				}
				pgm_clear_error (&sub_error);
				while (source_list) {
					pgm_free (source_list->data);
					source_list = pgm_list_delete_link (source_list, source_list);
				}
				if (!parse_interface_entity (family, NULL, &source_list, &sub_error) &&
				    !(sub_error && PGM_ERROR_NOTUNIQ == sub_error->code))
				{
					pgm_propagate_error (error, sub_error);
					goto free_lists;
				}
				pgm_clear_error (&sub_error);
				ec++;

			case ENTITY_RECEIVE:
				if (!parse_receive_entity (family, entity, &source_list, recv_list, error))
					goto free_lists;
				break;

			case ENTITY_SEND:
				if (!parse_send_entity (family, entity, &source_list, recv_list, send_list, error))
					goto free_lists;
				break;

			default:
				pgm_assert_not_reached();
				break;
			}

			b = ++p;
			continue;
		}

		p++;
	}

	if (b < e) {
		switch (ec++) {
		case ENTITY_INTERFACE:
			if (parse_interface_entity (family, b, &source_list, &sub_error))
				break;
			if (!(sub_error && PGM_ERROR_XDEV == sub_error->code))
			{
/* fall through on multicast */
				if (!(sub_error && PGM_ERROR_NOTUNIQ == sub_error->code))
				{
					pgm_propagate_error (error, sub_error);
					goto free_lists;
				}
				pgm_clear_error (&sub_error);

/* FIXME: too many interfaces */
				if (pgm_list_length (source_list) > 1) {
					pgm_set_error (error,
			   			     PGM_ERROR_DOMAIN_IF,
						     PGM_ERROR_INVAL,
						     _("Send group list contains more than one entity."));
					goto free_lists;
				}
				break;
			}
			pgm_clear_error (&sub_error);
			while (source_list) {
				pgm_free (source_list->data);
				source_list = pgm_list_delete_link (source_list, source_list);
			}
			if (!parse_interface_entity (family, NULL, &source_list, &sub_error) &&
			    !(sub_error && PGM_ERROR_NOTUNIQ == sub_error->code))
			{
				pgm_propagate_error (error, sub_error);
				goto free_lists;
			}
			ec++;

		case ENTITY_RECEIVE:
			if (!parse_receive_entity (family, b, &source_list, recv_list, error))
				goto free_lists;
			break;

		case ENTITY_SEND:
			if (!parse_send_entity (family, b, &source_list, recv_list, send_list, error))
				goto free_lists;
			break;

		default:
			pgm_assert_not_reached();
			break;
		}
	}

	while (ec <= ENTITY_SEND)
	{
		switch (ec++) {
		case ENTITY_INTERFACE:
			if (!parse_interface_entity (family, NULL, &source_list, error))
				goto free_lists;
			break;

		case ENTITY_RECEIVE:
			if (!parse_receive_entity (family, NULL, &source_list, recv_list, error))
				goto free_lists;
			break;

		case ENTITY_SEND:
			if (!parse_send_entity (family, NULL, &source_list, recv_list, send_list, error))
				goto free_lists;
			break;

		default:
			pgm_assert_not_reached();
			break;
		}
	}

	if (pgm_list_length (source_list) > 1)
		goto free_lists;

/* cleanup source interface list */
	while (source_list) {
		pgm_free (source_list->data);
		source_list = pgm_list_delete_link (source_list, source_list);
	}

	return TRUE;

free_lists:
	while (source_list) {
		pgm_free (source_list->data);
		source_list = pgm_list_delete_link (source_list, source_list);
	}
	while (*recv_list) {
		pgm_free ((*recv_list)->data);
		*recv_list = pgm_list_delete_link (*recv_list, *recv_list);
	}
	while (*send_list) {
		pgm_free ((*send_list)->data);
		*send_list = pgm_list_delete_link (*send_list, *send_list);
	}
	return FALSE;
}

/* create group_source_req as used by pgm_transport_create which specify port, address & interface.
 * gsr_source is copied from gsr_group for ASM, caller needs to populate gsr_source for SSM.
 *
 * returns TRUE on success, returns FALSE on error and sets error appropriately.
 */

bool
pgm_getaddrinfo (
	const char*			   restrict network,
	const struct pgm_addrinfo_t* const restrict hints,
	struct pgm_addrinfo_t**		   restrict res,
	pgm_error_t**			   restrict error
	)
{
	struct pgm_addrinfo_t* ai;
	const int family = hints ? hints->ai_family : AF_UNSPEC;
	pgm_list_t* recv_list = NULL;	/* <struct group_source_req*> */
	pgm_list_t* send_list = NULL;	/* <struct group_source_req*> */

	pgm_return_val_if_fail (NULL != network, FALSE);
	pgm_return_val_if_fail (AF_UNSPEC == family || AF_INET == family || AF_INET6 == family, FALSE);
	pgm_return_val_if_fail (NULL != res, FALSE);

	if (hints) {
		pgm_debug ("pgm_getaddrinfo (network:%s%s%s hints: {family:%s} res:%p error:%p)",
			network ? "\"" : "", network ? network : "(null)", network ? "\"" : "",
			pgm_family_string (family),
			(const void*)res,
			(const void*)error);
	} else {
		pgm_debug ("pgm_getaddrinfo (network:%s%s%s hints:%p res:%p error:%p)",
			network ? "\"" : "", network ? network : "(null)", network ? "\"" : "",
			(const void*)hints,
			(const void*)res,
			(const void*)error);
	}

	if (!network_parse (network, family, &recv_list, &send_list, error))
		return FALSE;
	const size_t recv_list_len = pgm_list_length (recv_list);
	const size_t send_list_len = pgm_list_length (send_list);
	ai = pgm_malloc0 (sizeof(struct pgm_addrinfo_t) + 
			 (recv_list_len + send_list_len) * sizeof(struct group_source_req));
	ai->ai_recv_addrs_len = recv_list_len;
	ai->ai_recv_addrs = (void*)((char*)ai + sizeof(struct pgm_addrinfo_t));
	ai->ai_send_addrs_len = send_list_len;
	ai->ai_send_addrs = (void*)((char*)ai->ai_recv_addrs + recv_list_len * sizeof(struct group_source_req));
			
	size_t i = 0;
	while (recv_list) {
		memcpy (&ai->ai_recv_addrs[i++], recv_list->data, sizeof(struct group_source_req));
		pgm_free (recv_list->data);
		recv_list = pgm_list_delete_link (recv_list, recv_list);
	}
	i = 0;
	while (send_list) {
		memcpy (&ai->ai_send_addrs[i++], send_list->data, sizeof(struct group_source_req));
		pgm_free (send_list->data);
		send_list = pgm_list_delete_link (send_list, send_list);
	}
	*res = ai;
	return TRUE;
}

void
pgm_freeaddrinfo (
	struct pgm_addrinfo_t*	res
	)
{
	pgm_free (res);
}


static
const char*
pgm_family_string (
	const int	family
	)
{
	const char* c;

	switch (family) {
	case AF_UNSPEC:		c = "AF_UNSPEC"; break;
	case AF_INET:		c = "AF_INET"; break;
	case AF_INET6:		c = "AF_INET6"; break;
	default: c = "(unknown)"; break;
	}

	return c;
}

/* eof */