aboutsummaryrefslogtreecommitdiffstats
path: root/sysconfig/network-scripts/network-functions-ipv6
blob: 64b9b593ac0b7360496040f2f21044ca3e5608ff (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
# network-functions-ipv6
#
# Taken from: network-functions-ipv6
# (P) & (C) 1997-2005 by Peter Bieringer <pb@bieringer.de>
#
#  You will find more information on the initscripts-ipv6 homepage at
#   http://www.deepspace6.net/projects/initscripts-ipv6.html
#
# Version: 2006-08-03
#
#






##### Logging function
#  $1: <message> : message string
#  $2: [stdout|stderr].[err|warn[ing]|inf[o]|notice] : log level with optional channel, default is "stdout.notice"
#      [syslog.[facility.].err|warn[ing]|inf[o]|notice : syslog channel, default is "syslog.user.notice"
#  $3: <function name> : name of function which calls this log function, can be empty using ""
# return code: 0=ok 1=argument error  3=major problem
ipv6_log() {
	local message="$1"
	local level="$2"
	local name="$3"

	if [ -z "$message" ]; then
		echo $"ERROR: [ipv6_log] Missing 'message' (arg 1)" >/dev/stderr
		return 1
	fi
	if [ -z "$level" ]; then
		local level="stdout.notice"
	fi


	# Map loglevel now
	local fn=1
	local fnawk="print \$$fn"
	local t="$(echo $level | awk -F. "{ $fnawk }")"

	# Check channel, if given
	case $t in
	    'stdout'|'stderr'|'syslog')
		local channel="$t"
		local fn=$(($fn + 1))
		;;
	    *)
		local channel="stdout"
		;;
	esac

	# Check syslog facilty, if given
	if [ "$channel" = "syslog" ]; then
		local fnawk="print \$$fn"
		local t="$(echo $level | awk -F. "{ $fnawk }")"
		case $t in
		    'local0'|'local1'|'local2'|'local3'|'local4'|'local5'|'local6'|'local7'|'daemon')
			local facility="$t"
			local fn=$(($fn + 1))
			;;
		    *)
			local facility="user"
			;;
		esac
	fi

	local fnawk="print \$$fn"
	local t="$(echo $level | awk -F. "{ $fnawk }")"

	# Map priority
	[ "$t" = "inf"      ] && local t="info"
	[ "$t" = "deb"      ] && local t="debug"
	[ "$t" = "warning"  ] && local t="warn"
	[ "$t" = "error"    ] && local t="err"
	[ "$t" = "critical" ] && local t="crit"

	# Check priority, if given
	case $t in
	    'info'|'debug'|'notice'|'warn'|'err'|'crit')
			local priority="$t"
			local fn=$(($fn + 1))
			;;
		    *)
			local priority="notice"
			;;
	esac

	local fnawk="print \$$fn"
	local t="$(echo $level | awk -F. "{ $fnawk }")"
	if [ -n "$t" ]; then
		echo $"ERROR: [ipv6_log] Loglevel isn't valid '$level' (arg 2)" >/dev/stderr
		return 1
	fi

	# Generate function text
	if [ -z "$name" ]; then
		local txt_name=""
	else
		local txt_name="[$name]"
	fi

	# Log message
	case $channel in
	    'stdout'|'stderr')
		# Generate level text
		case $priority in
		    'debug')
			local txt_level=$"DEBUG    "
			;;
		    'err')
			local txt_level=$"ERROR    "
			;;
		    'warn')
			local txt_level=$"WARN     "
			;;
		    'crit')
			local txt_level=$"CRITICAL "
			;;
		    'info')
			local txt_level=$"INFO     "
			;;
		    'notice')
			local txt_level=$"NOTICE   "
			;;
		esac

		[ -n "$txt_name" ] && local txt_name="$txt_name "

		if [ "$channel" = "stderr" ]; then
			echo "$txt_level: ${txt_name}${message}" >/dev/stderr
		elif [ "$channel" = "stdout" ]; then
			echo "$txt_level: ${txt_name}${message}"
		fi
		;;
	    'syslog')
		# note: logger resides in /usr/bin, but not used by default
		if ! [ -x /usr/bin/logger ]; then
			echo $"ERROR: [ipv6_log] Syslog is chosen, but binary 'logger' doesn't exist or isn't executable" >/dev/stderr
			return 3
		fi
		if [ -z "$txt_name" ]; then
			/usr/bin/logger -p $facility.$priority $message
		else
			/usr/bin/logger -p $facility.$priority -t "$txt_name" "$message"
		fi
		;;
	    *)
		echo $"ERROR: [ipv6_log] Cannot log to channel '$channel'" >/dev/stderr
		return 3
		;;
	esac

	return 0
}


###### Beginning of main code here, always executed on "source|. network-functions-ipv6"



###### End of main code here


##### Test for IPv6 capabilites
# $1: (optional) testflag: currently supported: "testonly" (do not load a module)
# return code: 0=ok 2=IPv6 test fails
ipv6_test() {
	local fn="ipv6_test"

	local testflag=$1

	if ! [ -f /proc/net/if_inet6 ]; then
		if [ "$testflag" = "testonly" ]; then
			return 2
		else
			modprobe ipv6

			if ! [ -f /proc/net/if_inet6 ]; then
				#	ipv6_log $"Kernel is not compiled with IPv6 support" crit $fn
				return 2
			fi
		fi
	fi

	if ! [ -d /proc/sys/net/ipv6/conf/ ]; then
		return 2
	fi

	return 0
}

##### Static IPv6 route configuration

# Set static IPv6 route
#  $1: <IPv6 network> : to route
#  $2: <IPv6 gateway> : over which $1 should be routed (if "::", gw will be skipped)
#  $3: [<Interface>] : (optional)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem adding route
ipv6_add_route() {
	local fn="ipv6_add_route"

	local networkipv6=$1
	local gatewayipv6=$2
	local device=$3		# maybe empty

	if [ -z "$networkipv6" ]; then
		ipv6_log $"Missing parameter 'IPv6-network' (arg 1)" err $fn
		return 1
	fi

	if [ -z "$gatewayipv6" ]; then
		ipv6_log $"Missing parameter 'IPv6-gateway' (arg 2)" err $fn
		return 1
	fi

	ipv6_test || return 2

	ipv6_test_ipv6_addr_valid $networkipv6 || return 2
	ipv6_test_ipv6_addr_valid $gatewayipv6 || return 2

	if [ -z "$device" ]; then
		local returntxt="$(/sbin/ip -6 route add $networkipv6 via $gatewayipv6 metric 1 2>&1)"
	else
		if [ "$gatewayipv6" = "::" ]; then
			local returntxt="$(/sbin/ip -6 route add $networkipv6 dev $device metric 1 2>&1)"
		else
			local returntxt="$(/sbin/ip -6 route add $networkipv6 via $gatewayipv6 dev $device metric 1 2>&1)"
		fi
	fi

	if [ -n "$returntxt" ]; then
		if echo $returntxt | LC_ALL=C grep -q "File exists"; then
			# Netlink: "File exists"
			true
		elif echo $returntxt | LC_ALL=C grep -q "No route to host"; then
			# Netlink: "No route to host"
			ipv6_log $"'No route to host' adding route '$networkipv6' via gateway '$gatewayipv6' through device '$device'" warn $fn
			return 3
		else
			ipv6_log $"Unknown error" warn $fn
			return 3
		fi
	fi

	return 0
}

##### automatic tunneling configuration

## Configure automatic tunneling up
# return code: 0=ok 2=IPv6 test fails 3=major problem
ipv6_enable_autotunnel() {
	local fn="ipv6_enable_autotunnel"

	ipv6_test || return 2

	# enable IPv6-over-IPv4 tunnels
	if ipv6_test_device_status sit0; then
		true
	else
		# bring up basic tunnel device
		/sbin/ip link set sit0 up

			if ! ipv6_test_device_status sit0; then
				ipv6_log $"Tunnel device 'sit0' enabling didn't work" err $fn
				return 3
			fi

		# Set sysctls proper (regardless "default")
		/sbin/sysctl -e -w net.ipv6.conf.sit0.forwarding=1 >/dev/null 2>&1
		/sbin/sysctl -e -w net.ipv6.conf.sit0.accept_ra=0 >/dev/null 2>&1
		/sbin/sysctl -e -w net.ipv6.conf.sit0.accept_redirects=0 >/dev/null 2>&1
	fi

	return 0
}

##### Interface configuration

## Add an IPv6 address for given interface
#  $1: <Interface>
#  $2: <IPv6 address[/prefix]>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_add_addr_on_device() {
	local fn="ipv6_add_addr_on_device"

	local device=$1
	local address=$2

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	if [ -z "$address" ]; then
		ipv6_log $"Missing parameter 'IPv6-address' (arg 2)" err $fn
		return 1
	fi

	ipv6_test || return 2

	ipv6_test_ipv6_addr_valid $address || return 1

	ipv6_test_device_status $device
	local result=$?

	if [ "$result" = "0" ]; then
		true
	elif [ "$result" != "11" ]; then
		ipv6_log $"Device '$device' doesn't exist" err $fn
		return 3
	else
		/sbin/ip link set $device up

			if ! ipv6_test_device_status $device; then
				ipv6_log $"Device '$device' enabling didn't work" err $fn
				return 3
			fi
	fi

	# Extract address parts
	local prefixlength_implicit="$(echo $address | awk -F/ '{ print $2 }')"
	local address_implicit="${address%%/*}"

	# Check prefix length and using '64' as default
	if [ -z "$prefixlength_implicit" ]; then
		local prefixlength_implicit="64"
		local address="$address_implicit/$prefixlength_implicit"
	fi

	/sbin/ip -6 addr add $address dev $device
	local result=$?

	if [ $result -eq 2 ]; then
		return 0
	elif [ $result -ne 0 ]; then
		ipv6_log $"Cannot add IPv6 address '$address' on dev '$device'" err $fn
		return 3
	fi

	return 0
}


## Remove all IPv6 routes and addresses on given interface (cleanup to prevent kernel crashes)
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_cleanup_device() {
	local fn="ipv6_cleanup_device"

	local device=$1

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	ipv6_test testonly || return 2

	# Remove all IPv6 routes through this device (but not "lo")
	if [ "$device" != "lo" ]; then
		/sbin/ip -6 route flush dev $device scope global >/dev/null 2>&1
		/sbin/ip -6 route flush dev $device scope site   >/dev/null 2>&1
	fi

	# Remove all IPv6 addresses on this interface
	/sbin/ip -6 addr flush dev $device scope global >/dev/null 2>&1
	/sbin/ip -6 addr flush dev $device scope site   >/dev/null 2>&1

	return 0
}


## Remove all IPv6 6to4 related routes and addresses on given interface
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_cleanup_6to4_device() {
	local fn="ipv6_cleanup_6to4_device"

	local device=$1

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	ipv6_test testonly || return 2

	# Cleanup 6to4 addresses on this device
	/sbin/ip -6 addr show dev $dev scope global permanent | awk '/\<inet6\>/ && $2 ~ /^2002:/ { print $2 }' | while read addr; do
		/sbin/ip -6 addr del ${addr} dev ${dev}
	done

	# Get all IPv6 routes through given interface related to 6to4 and remove them
	/sbin/ip -6 route show dev $device | LC_ALL=C grep "^2002:" | while read ipv6net dummy; do
		/sbin/ip -6 route del $ipv6net dev $device
	done

	return 0
}


##### Some address test functions

## Test a given IPv6 address for validity
#  $1: <IPv6 address>
# return code: 0=ok 1=not valid
ipv6_test_ipv6_addr_valid() {
	ipcalc -cs6 $1
}


## Test a given IPv4 address for validity
#  $1: <IPv4 address>
# return code: 0=ok 1=not valid
ipv6_test_ipv4_addr_valid() {
	ipcalc -cs4 $1
}


## Test a given IPv4 address for not a private but unicast one
#  $1: <IPv4 address>
# return code: 0=ok 1=argument error 10=private or not unicast
ipv6_test_ipv4_addr_global_usable() {
	local fn="ipv6_test_ipv4_addr_global_usable"

	local testipv4addr_globalusable=$1


	if [ -z "$testipv4addr_globalusable" ]; then
		return 1
	fi

	# Test for a globally usable IPv4 address now
		# test 0.0.0.0/8
		/bin/ipcalc --network $testipv4addr_globalusable 255.0.0.0   | LC_ALL=C grep -q "NETWORK=0\.0\.0\.0"     && return 10
		# test 10.0.0.0/8     (RFC 1918 / private)
		/bin/ipcalc --network $testipv4addr_globalusable 255.0.0.0   | LC_ALL=C grep -q "NETWORK=10\.0\.0\.0"    && return 10
		# test 127.0.0.0/8    (loopback)
		/bin/ipcalc --network $testipv4addr_globalusable 255.0.0.0   | LC_ALL=C grep -q "NETWORK=127\.0\.0\.0"   && return 10
		# test 169.254.0.0/16 (APIPA / DHCP link local)
		/bin/ipcalc --network $testipv4addr_globalusable 255.255.0.0 | LC_ALL=C grep -q "NETWORK=169\.254\.0\.0" && return 10
		# test 172.16.0.0/12  (RFC 1918 / private)
		/bin/ipcalc --network $testipv4addr_globalusable 255.240.0.0 | LC_ALL=C grep -q "NETWORK=172\.16\.0\.0"  && return 10
		# test 192.168.0.0/16 (RFC 1918 / private)
		/bin/ipcalc --network $testipv4addr_globalusable 255.255.0.0 | LC_ALL=C grep -q "NETWORK=192\.168\.0\.0" && return 10
		# test 224.0.0.0/3    (multicast and reserved, broadcast)
		/bin/ipcalc --network $testipv4addr_globalusable 224.0.0.0   | LC_ALL=C grep -q "NETWORK=224\.0\.0\.0"   && return 10

	return 0
}


## Test a given device for status
#  $1: <Interface>
# return code: 0=ok 1=argument error 10=not exists 11=down
ipv6_test_device_status() {
	local fn="ipv6_test_device_status"

	local device=$1

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	# Test if device exists
	if [ ! -d "/sys/class/net/${device}" ]; then
		# not exists
		return 10
	fi

	# Test if device is up
	if /sbin/ip link show dev $device 2>/dev/null | LC_ALL=C grep -q "UP"; then
		# up
		return 0
	else
		# down
		return 11
	fi
}


## Create 6to4 prefix
#  $1: <IPv4 address>
# stdout: <6to4address>
# return code: 0=ok 1=argument error
ipv6_create_6to4_prefix() {
	local fn="ipv6_create_6to4_prefix"

	local ipv4addr=$1

	if [ -z "$ipv4addr" ]; then
		ipv6_log $"Missing parameter 'IPv4 address' (arg 1)" stderr.err $fn
	fi

	local major1="${ipv4addr%%.*}"
	local minor1="$(echo $ipv4addr | awk -F. '{ print $2 }')"
	local major2="$(echo $ipv4addr | awk -F. '{ print $3 }')"
	local minor2="$(echo $ipv4addr | awk -F. '{ print $4 }')"

	if [ -z "$major1" -o -z "$minor1" -o -z "$major2" -o -z "$minor2" ]; then
		return 1
	fi

	if [ $major1 -eq 0 ]; then
		local block1="$(printf "%x" $minor1)"
	else
		local block1="$(printf "%x%02x" $major1 $minor1)"
	fi
	if [ $major2 -eq 0 ]; then
		local block2="$(printf "%x" $minor2)"
	else
		local block2="$(printf "%x%02x" $major2 $minor2)"
	fi

	local prefix6to4="2002:$block1:$block2"

	echo "$prefix6to4"
	return 0
}


## Check and create 6to4 tunnel relay address
#  $1: <IPv4 address|IPv6to4 address>
# stdout: <tunnel relay address>
# return code: 0=ok 1=argument error
ipv6_create_6to4_relay_address() {
	local fn="ipv6_create_6to4_relay_address"

	local addr=$1

	if [ -z "$addr" ]; then
		ipv6_log $"Missing parameter 'address' (arg 1)" stderr.err $fn
		return 1
	fi

	# Check
	if ipv6_test_ipv4_addr_valid $addr ; then
		# ok, a IPv4 one
		if ipv6_test_ipv4_addr_global_usable $addr; then
			# IPv4 globally usable
			local ipv6to4_relay="::$addr"
		else
			ipv6_log $"Given address '$addr' is not a global IPv4 one (arg 1)" stderr.err $fn
			return 1
		fi
	else
		ipv6_log $"Given address '$addr' is not a valid IPv4 one (arg 1)" stderr.err $fn
		return 1
	fi

	echo "$ipv6to4_relay"

	return 0
}


##### 6to4 tunneling setup

## Configure 6to4 tunneling up
#  $1: <Interface> : only "tun6to4" is supported
#  $2: <IPv4 address> : global IPv4 address of interface (will be used to generate 6to4 prefix)
#  $3: [<IPv6 suffix>] : for 6to4 prefix (optional, default is "::1")
#  $4: [<MTU>] : MTU of tunnel device (optional, default is automatic)
#  $5: [<IPv4 address>] : local IPv4 address of tunnel interface (required in case of 6to4 behind NAT)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_add_6to4_tunnel() {
	local fn="ipv6_add_6to4_tunnel"

	local device=$1
	local globalipv4=$2
	local globalipv6to4suffix=$3
	local mtu=$4
	local localipv4=$5

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	if [ -z "$globalipv4" ]; then
		ipv6_log $"Missing parameter 'global IPv4 address' (arg 2)" err $fn
		return 1
	fi

	# Check device
	if [ "$device" != "tun6to4" ]; then
		ipv6_log $"Given device '$device' is not supported (arg 1)" err $fn
		return 1
	fi

	# Copy global IPv4 address to local if last one is not given
	if [ -z "$localipv4" ]; then
		localipv4="$globalipv4"
	fi

	ipv6_test || return 2

	# Generate 6to4 address
	local prefix6to4="$(ipv6_create_6to4_prefix $globalipv4)"
	if [ $? -ne 0 -o -z "$prefix6to4" ]; then
		return 3
	fi

	if [ -z "$globalipv6to4suffix" ]; then
		local address6to4="${prefix6to4}::1/16"
	else
		local address6to4="${prefix6to4}::${globalipv6to4suffix}/16"
	fi

		ipv6_add_tunnel_device tun6to4 0.0.0.0 $address6to4 $localipv4
		if [ $? -ne 0 ]; then
			local retval=3
		else
			local retval=0
		fi

		# Add unspecific unreachable route for local 6to4 address space
		/sbin/ip route add unreach ${prefix6to4}::/48

	# Set MTU, if given
	if [ -n "$mtu" ]; then
		ipv6_set_mtu $device $mtu
	fi

	return $retval
}


## Configure all 6to4 tunneling down
#  $1: <Interface> : only "tun6to4" is supported
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_cleanup_6to4_tunnels() {
	local fn="ipv6_cleanup_6to4_tunnels"

	local device=$1

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	# Check device
	if [ "$device" != "tun6to4" ]; then
		ipv6_log $"Given device '$device' is not supported (arg 1)" err $fn
		return 1
	fi

	ipv6_test testonly || return 2

		ipv6_del_tunnel_device tun6to4

		# Remove all unspecific unreachable routes for local 6to4 address space
		/sbin/ip -6 route | LC_ALL=C grep "^unreachable 2002:.*/48 dev lo" | while read token net rest; do
			/sbin/ip route del unreach $net
		done

	return 0
}


## Configure 6to4 tunneling down
#  $1: <Interface> : only "tun6to4" is supported
#  $2: <IPv4 address> : global address of local interface
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_del_6to4_tunnel() {
	local fn="ipv6_del_6to4_tunnel"

	local device=$1
	local localipv4=$2

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	if [ -z "$localipv4" ]; then
		ipv6_log $"Missing parameter 'local IPv4 address' (arg 2)" err $fn
		return 1
	fi

	# Check device
	if [ "$device" != "tun6to4" ]; then
		ipv6_log $"Given device '$device' is not supported (arg 1)" err $fn
		return 1
	fi

	ipv6_test || return 2

		ipv6_del_tunnel_device tun6to4
		local retval=$?

		# Remove unspecific unreachable route for local 6to4 address space
		/sbin/ip route del unreach ${prefix6to4}::/48

	return $retval
}


## Configure a static tunnel device up
#  $1: <Interface>
#  $2: <IPv4 address> : of foreign tunnel
#  $3: [<IPv6 address>] : local one of a P-t-P tunnel (optional)
#  $4: [<IPv4 address>] : local one of tunnel (optional)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_add_tunnel_device() {
	local fn="ipv6_add_tunnel_device"

	local device=$1
	local addressipv4tunnel=$2
	local addressipv6local=$3
	local addressipv4tunnellocal=$4

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	if [ -z "$addressipv4tunnel" ]; then
		ipv6_log $"Missing parameter 'IPv4-tunnel address' (arg 2)" err $fn
		return 1
	fi

	if [ -z "$addressipv4tunnellocal" ]; then
		local addressipv4tunnellocal="any"
	fi

	ipv6_test || return 2

	if ! ipv6_test_device_status $device; then
		local ttldefault="$(/sbin/sysctl -e net.ipv4.ip_default_ttl | awk '{ print $3 }')"
		if [ -z "$ttldefault" ]; then
			local ttldefault=64
		fi

		# Test whether remote IPv4 address was already applied to another tunnel
		if [ "$addressipv4tunnel" != "0.0.0.0" -a "$addressipv4tunnel" != "any" ]; then
			/sbin/ip tunnel show remote $addressipv4tunnel 2>/dev/null | LC_ALL=C grep -w "ipv6/ip" | while IFS=":" read devnew rest; do
				if [ "$devnew" != "$device" ]; then
					ipv6_log $"Given remote address '$addressipv4tunnel' on tunnel device '$device' is already configured on device '$devnew'" err $fn
					return 3
				fi
			done
		fi

		/sbin/ip tunnel add $device mode sit ttl $ttldefault remote $addressipv4tunnel local $addressipv4tunnellocal
		if [ $? -ne 0 ]; then
			return 3
		fi

		# Test, whether "ip tunnel show" reports valid content
		if ! /sbin/ip tunnel show $device 2>/dev/null | LC_ALL=C grep -q -w "remote"; then
			ipv6_log $"Tunnel device '$device' creation didn't work" err $fn
			return 3
		fi

		/sbin/ip link set $device up

		if ! ipv6_test_device_status $device; then
			ipv6_log $"Tunnel device '$device' bringing up didn't work" err $fn
			return 3
		fi

		# Set sysctls proper (regardless "default")
		/sbin/sysctl -e -w net.ipv6.conf.$SYSCTLDEVICE.forwarding=1 >/dev/null 2>&1
		/sbin/sysctl -e -w net.ipv6.conf.$SYSCTLDEVICE.accept_ra=0 >/dev/null 2>&1
		/sbin/sysctl -e -w net.ipv6.conf.$SYSCTLDEVICE.accept_redirects=0 >/dev/null 2>&1

		if [ -n "$addressipv6local" ]; then
			# Setup P-t-P address
			ipv6_add_addr_on_device $device $addressipv6local
			if [ $? -ne 0 ]; then
				return 3
			fi
		fi
	else
		false
	fi

	return 0
}


## Configure a static tunnel device down
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_del_tunnel_device() {
	local fn="ipv6_del_tunnel_device"

	local device=$1

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	ipv6_test testonly || return 2

	if ipv6_test_device_status $device; then
		ipv6_cleanup_device $device
	else
		if [ "$device" != "sit0" ]; then
			false
		fi
	fi

	if [ "$device" != "sit0" ]; then
		if /sbin/ip tunnel show $device 2>/dev/null | LC_ALL=C grep -q -w "ipv6/ip"; then
			/sbin/ip tunnel del $device

				if ipv6_test_device_status $device; then
					return 3
				fi
		else
			false
		fi
	fi

	return 0
}


## Cleanup all dedicated tunnel devices
ipv6_cleanup_tunnel_devices() {
	local fn="ipv6_cleanup_tunnel_devices"

	ipv6_test testonly || return 2

	# Find still existing tunnel devices and shutdown and delete them

	/sbin/ip tunnel show | awk -F: '/\<ipv6\/ip\>/ { print $1 }' | while read device; do
		ipv6_del_tunnel_device $device
	done

	return 0
}


## Get address of a dedicated tunnel
#  $1: <Interface>
#  $2: local|remote : local or remote address
# stdout: <IPv4 address> if available
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_get_ipv4addr_of_tunnel() {
	local fn="ipv6_get_local_ipv4_of_tunnel"

	local device=$1
	local selection=$2

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" stderr.err $fn
		return 1
	fi

	if [ -z "$selection" ]; then
		ipv6_log $"Missing parameter 'selection' (arg 2)" stderr.err $fn
		return 1
	fi
	if [ "$selection" != "local" -a "$selection" != "remote" ]; then
		ipv6_log $"Unsupported selection '$selection' specified (arg 2)" stderr.err $fn
		return 1
	fi

	ipv6_test testonly || return 2

	ipv6_test_device_status $device

	if [ $? != 0 -a $? != 11 ]; then
		# Device doesn't exist
		return 3
	fi

	# Device exists, retrieve address
	if [ "$selection" = "local" ]; then
		local tunnel_local_ipv4addr="$(/sbin/ip tunnel show $device | awk '{ print $6 }')"
	elif [ "$selection" = "remote" ]; then
		local tunnel_local_ipv4addr="$(/sbin/ip tunnel show $device | awk '{ print $4 }')"
	fi

	if [ $? != 0 ]; then
		return 3
	fi

	if [ "$tunnel_local_ipv4addr" = "any" ]; then
		local tunnel_local_ipv4addr="0.0.0.0"
	fi

	echo "$tunnel_local_ipv4addr"

	return 0
}


## Get IPv4 address of a device
#  $1: <Interface>
# stdout: <IPv4 address> if available
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem (more than one IPv4 address applied)
ipv6_get_ipv4addr_of_device() {
	local fn="ipv6_get_ipv4addr_of_device"

	local device=$1

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" stderr.err $fn
		return 1
	fi

	ipv6_test_device_status $device

	if [ $? != 0 -a $? != 11 ]; then
		# Device doesn't exist
		return 3
	fi

	# Device exists, retrieve the first address only
	local ipv4addr="$(/sbin/ip -o -4 addr show dev $device | awk '{ print $4 }' | awk -F/ '{ print $1; exit }')"

	if [ $? != 0 ]; then
		return 3
	fi

	if [ "$ipv4addr" = "any" ]; then
		local ipv4addr="0.0.0.0"
	fi

	echo "$ipv4addr"

	return 0
}


## Set IPv6 MTU for a device
#  $1: <Interface>
#  $2: <IPv6 MTU>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_set_mtu() {
	local fn="ipv6_set_mtu"

	local device=$1
	local ipv6_mtu=$2

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	if [ -z "$ipv6_mtu" ]; then
		ipv6_log $"Missing parameter 'IPv6 MTU' (arg 2)" err $fn
		return 1
	fi

	# Check range
	if [ $ipv6_mtu -lt 1280 -o $ipv6_mtu -gt 65535 ]; then
		ipv6_log $"Given IPv6 MTU '$ipv6_mtu' is out of range" err $fn
		return 1
	fi

	ipv6_test testonly || return 2

	# Set value
	/sbin/ip link set dev $device mtu $ipv6_mtu

	return 0
}


## Set a default route
#  $1: <IPv6 address> : gateway, can also contain scope suffix (device name), cause a warning if not matching with $2 (but will have precedence)
#  $2: <gateway device>: gateway device (optional in case of $1 is a global address or $1 contains scope suffix)
#  $3: <check device>: (optional) device to check scope and gateway device against (setup is skipped, if not matching)
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_set_default_route() {
	local fn="ipv6_set_default_route"

	local address=$1
	local device=$2
	local device_check=$3

	ipv6_test testonly || return 2

	# Map the unspecified address to nothing
	if [ "$address" = "::" ]; then
		local address=""
	fi

	if [ -n "$address" ]; then
		local addressgw=${address%%%*}
		local device_scope=$(echo $address | awk -F% '{ print $2 }')

		if [ -z "$addressgw" ]; then
			ipv6_log $"Given IPv6 default gateway '$address' is not in proper format" err $fn
			return 3
		fi

		# Scope device has precedence
		if [ -n "$device_scope" -a -n "$device" -a "$device_scope" != "$device" ]; then
			ipv6_log $"Given IPv6 default gateway '$address' has scope '$device_scope' defined, given default gateway device '$device' will be not used" inf $fn
			local device=""
		fi

		# Link local addresses require a device
		if echo $addressgw | LC_ALL=C grep -qi "^fe80:"; then
			if [ -z "$device_scope" ]; then
				if [ -z "$device" ]; then
					ipv6_log $"Given IPv6 default gateway '$address' is link-local, but no scope or gateway device is specified" err $fn
					return 3
				fi
			fi
		fi

		# Check whether the route belongs to the specific given interface
		if [ -n "$device_check" ]; then
			# Check whether scope device matches given check device
			if [ -n "$device_scope" -a "$device_check" != "$device_scope" ]; then
				# scope device != specific given -> skip
				return 0
			elif [ -n "$device" -a "$device_check" != "$device" ]; then
				# gateway device != specific given -> skip
				return 0
			fi
		fi

		# Set device now, if not given
		if [ -z "$device" ]; then
			local device="$device_scope"
		fi

		if [ -z "$device" ]; then
			# Note: this can cause a warning and a not installed route, if given address is not reachable on the link
			ipv6_add_route ::/0 $addressgw
		else
			ipv6_add_route ::/0 $addressgw $device
		fi
	elif [ -n "$device" ]; then
		# Check whether the route belongs to the specific given interface
		if [ -n "$device_check" -a "$device_check" != "$device" ]; then
			# gateway device != specific given -> skip
			return 0
		fi

		ipv6_test_route_requires_next_hop $device
		local result=$?

		if [ $result = 0 ]; then
			ipv6_log $"Given IPv6 default device '$device' requires an explicit nexthop" err $fn
			return 3
		elif [ $result != 10 ]; then
			ipv6_log $"Given IPv6 default device '$device' doesn't exist or isn't up" err $fn
			return 3
		fi

		ipv6_add_route ::/0 :: $device
	else
		ipv6_log $"No parameters given to setup a default route" err $fn
		return 3
	fi

	return 0
}


## Resolve need of explicit next hop for an interface
#  $1: <Interface>
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem 10=needs no explicit hop
ipv6_test_route_requires_next_hop() {
	local fn="ipv6_test_route_requires_next_hop"

	local device=$1

	if [ -z "$device" ]; then
		ipv6_log $"Missing parameter 'device' (arg 1)" err $fn
		return 1
	fi

	ipv6_test testonly || return 2

	ipv6_test_device_status $device

	if [ $? != 0 ]; then
		return 3
	fi

	if [ "$device" = "sit0" ]; then
		return 10
	fi

	if /sbin/ip -o link show $device 2>/dev/null |  LC_ALL=C grep -q "POINTOPOINT"; then
		return 10
	fi

	return 0
}


## Trigger radvd
#  $1: up|down : device reason for triggering (coming up or going down)
#  $2: [startstop|restart|reload|SIGHUP] : triger mechanism (default is "SIGHUP")
#        "startstop" : reason=up -> start, reason=down -> stop
#  $3: [<filename>] : alternative pid file  [optional]
# return code: 0=ok 1=argument error 2=IPv6 test fails 3=major problem
ipv6_trigger_radvd() {
	local fn="ipv6_trigger_radvd"

	local reason=$1
	local mechanism=$2
	local pidfile=$3

	if [ -z "$reason" ]; then
		ipv6_log $"No reason given for sending trigger to radvd" err $fn
		return 1
	fi

	if [ "$reason" != "up" -a "$reason" != "down" ]; then
		ipv6_log $"Unsupported reason '$reason' for sending trigger to radvd" err $fn
		return 1
	fi

	if [ -z "$mechanism" ]; then
		# Take default
		local mechanism="SIGHUP"
	fi

	if [ -z "$pidfile" ]; then
		local pidfile="/var/run/radvd/radvd.pid"
	fi

	# Print message and select action
	case $mechanism in
	    'startstop')
		case $reason in
		    up)
			local action="start"
			;;
		    down)
			local action="stop"
			;;
		esac
		;;
	    'reload'|'restart'|'SIGHUP')
		local action="$mechanism"
		;;
	    *)
		ipv6_log $"Unsupported mechanism '$mechanism' for sending trigger to radvd" err $fn
		return 3
		;;
	esac

	# PID file needed?
	if [ "$action" = "SIGHUP" ]; then
		if ! [ -f "$pidfile" ]; then
			if [ "$reason" = "down" ]; then
				# be quiet because triggering may have been disabled
				true
			else
				ipv6_log $"Given pidfile '$pidfile' doesn't exist, cannot send trigger to radvd" err $fn
			fi
			return 3
		fi

		# Get PID
		local pid="$(cat $pidfile)"
		if [ -z "$pid" ]; then
			# pidfile empty - strange
			ipv6_log $"Pidfile '$pidfile' is empty, cannot send trigger to radvd" err $fn
			return 3
		fi
	fi


	# Do action
	case $action in
	    'SIGHUP')
		kill -HUP $pid
		;;
	    'reload'|'restart'|'stop'|'start')
			if ! /sbin/chkconfig --list radvd >/dev/null 2>&1; then
				if [ "$reason" = "down" ]; then
					# be quiet because triggering may have been disabled
					true
				else
					ipv6_log $"radvd not (properly) installed, triggering failed" err $fn
				fi
				return 3
			else
				/sbin/service radvd $action >/dev/null 2>&1
			fi
		;;
	    *)
		# Normally not reached, "action" is set above to proper value
		;;
	esac

	return 0
}