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
|
/* $FreeBSD$ */
/* $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $ */
/*-
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/sx.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#include <net/net_osdep.h>
static struct mtx addrsel_lock;
#define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF)
#define ADDRSEL_LOCK() mtx_lock(&addrsel_lock)
#define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock)
#define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED)
static struct sx addrsel_sxlock;
#define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock")
#define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock)
#define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock)
#define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock)
#define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock)
#define ADDR_LABEL_NOTAPP (-1)
struct in6_addrpolicy defaultaddrpolicy;
int ip6_prefer_tempaddr = 0;
static int selectroute __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *, struct ifnet **,
struct rtentry **, int, int));
static int in6_selectif __P((struct sockaddr_in6 *, struct ip6_pktopts *,
struct ip6_moptions *, struct route_in6 *ro, struct ifnet **));
static struct in6_addrpolicy *lookup_addrsel_policy __P((struct sockaddr_in6 *));
static void init_policy_queue __P((void));
static int add_addrsel_policyent __P((struct in6_addrpolicy *));
static int delete_addrsel_policyent __P((struct in6_addrpolicy *));
static int walk_addrsel_policy __P((int (*)(struct in6_addrpolicy *, void *),
void *));
static int dump_addrsel_policyent __P((struct in6_addrpolicy *, void *));
static struct in6_addrpolicy *match_addrsel_policy __P((struct sockaddr_in6 *));
/*
* Return an IPv6 address, which is the most appropriate for a given
* destination and user specified options.
* If necessary, this function lookups the routing table and returns
* an entry to the caller for later use.
*/
#define REPLACE(r) do {\
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
/* printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
goto replace; \
} while(0)
#define NEXT(r) do {\
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
/* printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
goto next; /* XXX: we can't use 'continue' here */ \
} while(0)
#define BREAK(r) do { \
if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
ip6stat.ip6s_sources_rule[(r)]++; \
goto out; /* XXX: we can't use 'break' here */ \
} while(0)
struct in6_addr *
in6_selectsrc(dstsock, opts, mopts, ro, laddr, ifpp, errorp)
struct sockaddr_in6 *dstsock;
struct ip6_pktopts *opts;
struct ip6_moptions *mopts;
struct route_in6 *ro;
struct in6_addr *laddr;
struct ifnet **ifpp;
int *errorp;
{
struct in6_addr dst;
struct ifnet *ifp = NULL;
struct in6_ifaddr *ia = NULL, *ia_best = NULL;
struct in6_pktinfo *pi = NULL;
int dst_scope = -1, best_scope = -1, best_matchlen = -1;
struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
u_int32_t odstzone;
int prefer_tempaddr;
dst = dstsock->sin6_addr; /* make a copy for local operation */
*errorp = 0;
if (ifpp)
*ifpp = NULL;
/*
* If the source address is explicitly specified by the caller,
* check if the requested source address is indeed a unicast address
* assigned to the node, and can be used as the packet's source
* address. If everything is okay, use the address as source.
*/
if (opts && (pi = opts->ip6po_pktinfo) &&
!IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
struct sockaddr_in6 srcsock;
struct in6_ifaddr *ia6;
/* get the outgoing interface */
if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ifp))
!= 0) {
return (NULL);
}
/*
* determine the appropriate zone id of the source based on
* the zone of the destination and the outgoing interface.
* If the specified address is ambiguous wrt the scope zone,
* the interface must be specified; otherwise, ifa_ifwithaddr()
* will fail matching the address.
*/
bzero(&srcsock, sizeof(srcsock));
srcsock.sin6_family = AF_INET6;
srcsock.sin6_len = sizeof(srcsock);
srcsock.sin6_addr = pi->ipi6_addr;
if (ifp) {
*errorp = in6_setscope(&srcsock.sin6_addr, ifp, NULL);
if (*errorp != 0)
return (NULL);
}
ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)(&srcsock));
if (ia6 == NULL ||
(ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
*errorp = EADDRNOTAVAIL;
return (NULL);
}
pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */
if (ifpp)
*ifpp = ifp;
return (&ia6->ia_addr.sin6_addr);
}
/*
* Otherwise, if the socket has already bound the source, just use it.
*/
if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
return (laddr);
/*
* If the address is not specified, choose the best one based on
* the outgoing interface and the destination address.
*/
/* get the outgoing interface */
if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ifp)) != 0)
return (NULL);
#ifdef DIAGNOSTIC
if (ifp == NULL) /* this should not happen */
panic("in6_selectsrc: NULL ifp");
#endif
*errorp = in6_setscope(&dst, ifp, &odstzone);
if (*errorp != 0)
return (NULL);
for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
int new_scope = -1, new_matchlen = -1;
struct in6_addrpolicy *new_policy = NULL;
u_int32_t srczone, osrczone, dstzone;
struct in6_addr src;
struct ifnet *ifp1 = ia->ia_ifp;
/*
* We'll never take an address that breaks the scope zone
* of the destination. We also skip an address if its zone
* does not contain the outgoing interface.
* XXX: we should probably use sin6_scope_id here.
*/
if (in6_setscope(&dst, ifp1, &dstzone) ||
odstzone != dstzone) {
continue;
}
src = ia->ia_addr.sin6_addr;
if (in6_setscope(&src, ifp, &osrczone) ||
in6_setscope(&src, ifp1, &srczone) ||
osrczone != srczone) {
continue;
}
/* avoid unusable addresses */
if ((ia->ia6_flags &
(IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
continue;
}
if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
continue;
/* Rule 1: Prefer same address */
if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) {
ia_best = ia;
BREAK(1); /* there should be no better candidate */
}
if (ia_best == NULL)
REPLACE(0);
/* Rule 2: Prefer appropriate scope */
if (dst_scope < 0)
dst_scope = in6_addrscope(&dst);
new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0)
REPLACE(2);
NEXT(2);
} else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0)
NEXT(2);
REPLACE(2);
}
/*
* Rule 3: Avoid deprecated addresses. Note that the case of
* !ip6_use_deprecated is already rejected above.
*/
if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia))
NEXT(3);
if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia))
REPLACE(3);
/* Rule 4: Prefer home addresses */
/*
* XXX: This is a TODO. We should probably merge the MIP6
* case above.
*/
/* Rule 5: Prefer outgoing interface */
if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp)
NEXT(5);
if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp)
REPLACE(5);
/*
* Rule 6: Prefer matching label
* Note that best_policy should be non-NULL here.
*/
if (dst_policy == NULL)
dst_policy = lookup_addrsel_policy(dstsock);
if (dst_policy->label != ADDR_LABEL_NOTAPP) {
new_policy = lookup_addrsel_policy(&ia->ia_addr);
if (dst_policy->label == best_policy->label &&
dst_policy->label != new_policy->label)
NEXT(6);
if (dst_policy->label != best_policy->label &&
dst_policy->label == new_policy->label)
REPLACE(6);
}
/*
* Rule 7: Prefer public addresses.
* We allow users to reverse the logic by configuring
* a sysctl variable, so that privacy conscious users can
* always prefer temporary addresses.
*/
if (opts == NULL ||
opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
prefer_tempaddr = ip6_prefer_tempaddr;
} else if (opts->ip6po_prefer_tempaddr ==
IP6PO_TEMPADDR_NOTPREFER) {
prefer_tempaddr = 0;
} else
prefer_tempaddr = 1;
if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (prefer_tempaddr)
REPLACE(7);
else
NEXT(7);
}
if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
!(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
if (prefer_tempaddr)
NEXT(7);
else
REPLACE(7);
}
/*
* Rule 8: prefer addresses on alive interfaces.
* This is a KAME specific rule.
*/
if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
!(ia->ia_ifp->if_flags & IFF_UP))
NEXT(8);
if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
(ia->ia_ifp->if_flags & IFF_UP))
REPLACE(8);
/*
* Rule 14: Use longest matching prefix.
* Note: in the address selection draft, this rule is
* documented as "Rule 8". However, since it is also
* documented that this rule can be overridden, we assign
* a large number so that it is easy to assign smaller numbers
* to more preferred rules.
*/
new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
if (best_matchlen < new_matchlen)
REPLACE(14);
if (new_matchlen < best_matchlen)
NEXT(14);
/* Rule 15 is reserved. */
/*
* Last resort: just keep the current candidate.
* Or, do we need more rules?
*/
continue;
replace:
ia_best = ia;
best_scope = (new_scope >= 0 ? new_scope :
in6_addrscope(&ia_best->ia_addr.sin6_addr));
best_policy = (new_policy ? new_policy :
lookup_addrsel_policy(&ia_best->ia_addr));
best_matchlen = (new_matchlen >= 0 ? new_matchlen :
in6_matchlen(&ia_best->ia_addr.sin6_addr,
&dst));
next:
continue;
out:
break;
}
if ((ia = ia_best) == NULL) {
*errorp = EADDRNOTAVAIL;
return (NULL);
}
if (ifpp)
*ifpp = ifp;
return (&ia->ia_addr.sin6_addr);
}
static int
selectroute(dstsock, opts, mopts, ro, retifp, retrt, clone, norouteok)
struct sockaddr_in6 *dstsock;
struct ip6_pktopts *opts;
struct ip6_moptions *mopts;
struct route_in6 *ro;
struct ifnet **retifp;
struct rtentry **retrt;
int clone; /* meaningful only for bsdi and freebsd. */
int norouteok;
{
int error = 0;
struct ifnet *ifp = NULL;
struct rtentry *rt = NULL;
struct sockaddr_in6 *sin6_next;
struct in6_pktinfo *pi = NULL;
struct in6_addr *dst = &dstsock->sin6_addr;
#if 0
if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
dstsock->sin6_addr.s6_addr32[1] == 0 &&
!IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
printf("in6_selectroute: strange destination %s\n",
ip6_sprintf(&dstsock->sin6_addr));
} else {
printf("in6_selectroute: destination = %s%%%d\n",
ip6_sprintf(&dstsock->sin6_addr),
dstsock->sin6_scope_id); /* for debug */
}
#endif
/* If the caller specify the outgoing interface explicitly, use it. */
if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
/* XXX boundary check is assumed to be already done. */
ifp = ifnet_byindex(pi->ipi6_ifindex);
if (ifp != NULL &&
(norouteok || retrt == NULL ||
IN6_IS_ADDR_MULTICAST(dst))) {
/*
* we do not have to check or get the route for
* multicast.
*/
goto done;
} else
goto getroute;
}
/*
* If the destination address is a multicast address and the outgoing
* interface for the address is specified by the caller, use it.
*/
if (IN6_IS_ADDR_MULTICAST(dst) &&
mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) {
goto done; /* we do not need a route for multicast. */
}
getroute:
/*
* If the next hop address for the packet is specified by the caller,
* use it as the gateway.
*/
if (opts && opts->ip6po_nexthop) {
struct route_in6 *ron;
sin6_next = satosin6(opts->ip6po_nexthop);
/* at this moment, we only support AF_INET6 next hops */
if (sin6_next->sin6_family != AF_INET6) {
error = EAFNOSUPPORT; /* or should we proceed? */
goto done;
}
/*
* If the next hop is an IPv6 address, then the node identified
* by that address must be a neighbor of the sending host.
*/
ron = &opts->ip6po_nextroute;
if ((ron->ro_rt &&
(ron->ro_rt->rt_flags & (RTF_UP | RTF_LLINFO)) !=
(RTF_UP | RTF_LLINFO)) ||
!SA6_ARE_ADDR_EQUAL(satosin6(&ron->ro_dst), sin6_next)) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
*satosin6(&ron->ro_dst) = *sin6_next;
}
if (ron->ro_rt == NULL) {
rtalloc((struct route *)ron); /* multi path case? */
if (ron->ro_rt == NULL ||
!(ron->ro_rt->rt_flags & RTF_LLINFO)) {
if (ron->ro_rt) {
RTFREE(ron->ro_rt);
ron->ro_rt = NULL;
}
error = EHOSTUNREACH;
goto done;
}
}
rt = ron->ro_rt;
ifp = rt->rt_ifp;
/*
* When cloning is required, try to allocate a route to the
* destination so that the caller can store path MTU
* information.
*/
if (!clone)
goto done;
}
/*
* Use a cached route if it exists and is valid, else try to allocate
* a new one. Note that we should check the address family of the
* cached destination, in case of sharing the cache with IPv4.
*/
if (ro) {
if (ro->ro_rt &&
(!(ro->ro_rt->rt_flags & RTF_UP) ||
((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 ||
!IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
dst))) {
RTFREE(ro->ro_rt);
ro->ro_rt = (struct rtentry *)NULL;
}
if (ro->ro_rt == (struct rtentry *)NULL) {
struct sockaddr_in6 *sa6;
/* No route yet, so try to acquire one */
bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
*sa6 = *dstsock;
sa6->sin6_scope_id = 0;
if (clone) {
rtalloc((struct route *)ro);
} else {
ro->ro_rt = rtalloc1(&((struct route *)ro)
->ro_dst, 0, 0UL);
if (ro->ro_rt)
RT_UNLOCK(ro->ro_rt);
}
}
/*
* do not care about the result if we have the nexthop
* explicitly specified.
*/
if (opts && opts->ip6po_nexthop)
goto done;
if (ro->ro_rt) {
ifp = ro->ro_rt->rt_ifp;
if (ifp == NULL) { /* can this really happen? */
RTFREE(ro->ro_rt);
ro->ro_rt = NULL;
}
}
if (ro->ro_rt == NULL)
error = EHOSTUNREACH;
rt = ro->ro_rt;
/*
* Check if the outgoing interface conflicts with
* the interface specified by ipi6_ifindex (if specified).
* Note that loopback interface is always okay.
* (this may happen when we are sending a packet to one of
* our own addresses.)
*/
if (ifp && opts && opts->ip6po_pktinfo &&
opts->ip6po_pktinfo->ipi6_ifindex) {
if (!(ifp->if_flags & IFF_LOOPBACK) &&
ifp->if_index !=
opts->ip6po_pktinfo->ipi6_ifindex) {
error = EHOSTUNREACH;
goto done;
}
}
}
done:
if (ifp == NULL && rt == NULL) {
/*
* This can happen if the caller did not pass a cached route
* nor any other hints. We treat this case an error.
*/
error = EHOSTUNREACH;
}
if (error == EHOSTUNREACH)
ip6stat.ip6s_noroute++;
if (retifp != NULL)
*retifp = ifp;
if (retrt != NULL)
*retrt = rt; /* rt may be NULL */
return (error);
}
static int
in6_selectif(dstsock, opts, mopts, ro, retifp)
struct sockaddr_in6 *dstsock;
struct ip6_pktopts *opts;
struct ip6_moptions *mopts;
struct route_in6 *ro;
struct ifnet **retifp;
{
int error;
struct route_in6 sro;
struct rtentry *rt = NULL;
if (ro == NULL) {
bzero(&sro, sizeof(sro));
ro = &sro;
}
if ((error = selectroute(dstsock, opts, mopts, ro, retifp,
&rt, 0, 1)) != 0) {
if (rt && rt == sro.ro_rt)
RTFREE(rt);
return (error);
}
/*
* do not use a rejected or black hole route.
* XXX: this check should be done in the L2 output routine.
* However, if we skipped this check here, we'd see the following
* scenario:
* - install a rejected route for a scoped address prefix
* (like fe80::/10)
* - send a packet to a destination that matches the scoped prefix,
* with ambiguity about the scope zone.
* - pick the outgoing interface from the route, and disambiguate the
* scope zone with the interface.
* - ip6_output() would try to get another route with the "new"
* destination, which may be valid.
* - we'd see no error on output.
* Although this may not be very harmful, it should still be confusing.
* We thus reject the case here.
*/
if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) {
int flags = (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
if (rt && rt == sro.ro_rt)
RTFREE(rt);
return (flags);
}
/*
* Adjust the "outgoing" interface. If we're going to loop the packet
* back to ourselves, the ifp would be the loopback interface.
* However, we'd rather know the interface associated to the
* destination address (which should probably be one of our own
* addresses.)
*/
if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp)
*retifp = rt->rt_ifa->ifa_ifp;
if (rt && rt == sro.ro_rt)
RTFREE(rt);
return (0);
}
int
in6_selectroute(dstsock, opts, mopts, ro, retifp, retrt, clone)
struct sockaddr_in6 *dstsock;
struct ip6_pktopts *opts;
struct ip6_moptions *mopts;
struct route_in6 *ro;
struct ifnet **retifp;
struct rtentry **retrt;
int clone; /* meaningful only for bsdi and freebsd. */
{
return (selectroute(dstsock, opts, mopts, ro, retifp,
retrt, clone, 0));
}
/*
* Default hop limit selection. The precedence is as follows:
* 1. Hoplimit value specified via ioctl.
* 2. (If the outgoing interface is detected) the current
* hop limit of the interface specified by router advertisement.
* 3. The system default hoplimit.
*/
int
in6_selecthlim(in6p, ifp)
struct in6pcb *in6p;
struct ifnet *ifp;
{
if (in6p && in6p->in6p_hops >= 0)
return (in6p->in6p_hops);
else if (ifp)
return (ND_IFINFO(ifp)->chlim);
else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
struct route_in6 ro6;
struct ifnet *lifp;
bzero(&ro6, sizeof(ro6));
ro6.ro_dst.sin6_family = AF_INET6;
ro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
ro6.ro_dst.sin6_addr = in6p->in6p_faddr;
rtalloc((struct route *)&ro6);
if (ro6.ro_rt) {
lifp = ro6.ro_rt->rt_ifp;
RTFREE(ro6.ro_rt);
if (lifp)
return (ND_IFINFO(lifp)->chlim);
} else
return (ip6_defhlim);
}
return (ip6_defhlim);
}
/*
* XXX: this is borrowed from in6_pcbbind(). If possible, we should
* share this function by all *bsd*...
*/
int
in6_pcbsetport(laddr, inp, cred)
struct in6_addr *laddr;
struct inpcb *inp;
struct ucred *cred;
{
struct socket *so = inp->inp_socket;
u_int16_t lport = 0, first, last, *lastport;
int count, error = 0, wild = 0;
struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
/* XXX: this is redundant when called from in6_pcbbind */
if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
wild = INPLOOKUP_WILDCARD;
inp->inp_flags |= INP_ANONPORT;
if (inp->inp_flags & INP_HIGHPORT) {
first = ipport_hifirstauto; /* sysctl */
last = ipport_hilastauto;
lastport = &pcbinfo->lasthi;
} else if (inp->inp_flags & INP_LOWPORT) {
if ((error = suser_cred(cred, 0)))
return error;
first = ipport_lowfirstauto; /* 1023 */
last = ipport_lowlastauto; /* 600 */
lastport = &pcbinfo->lastlow;
} else {
first = ipport_firstauto; /* sysctl */
last = ipport_lastauto;
lastport = &pcbinfo->lastport;
}
/*
* Simple check to ensure all ports are not used up causing
* a deadlock here.
*
* We split the two cases (up and down) so that the direction
* is not being tested on each round of the loop.
*/
if (first > last) {
/*
* counting down
*/
count = first - last;
do {
if (count-- < 0) { /* completely used? */
/*
* Undo any address bind that may have
* occurred above.
*/
inp->in6p_laddr = in6addr_any;
return (EAGAIN);
}
--*lastport;
if (*lastport > first || *lastport < last)
*lastport = first;
lport = htons(*lastport);
} while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
lport, wild));
} else {
/*
* counting up
*/
count = last - first;
do {
if (count-- < 0) { /* completely used? */
/*
* Undo any address bind that may have
* occurred above.
*/
inp->in6p_laddr = in6addr_any;
return (EAGAIN);
}
++*lastport;
if (*lastport < first || *lastport > last)
*lastport = first;
lport = htons(*lastport);
} while (in6_pcblookup_local(pcbinfo,
&inp->in6p_laddr, lport, wild));
}
inp->inp_lport = lport;
if (in_pcbinshash(inp) != 0) {
inp->in6p_laddr = in6addr_any;
inp->inp_lport = 0;
return (EAGAIN);
}
return (0);
}
void
addrsel_policy_init()
{
ADDRSEL_LOCK_INIT();
ADDRSEL_SXLOCK_INIT();
init_policy_queue();
/* initialize the "last resort" policy */
bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy));
defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
}
static struct in6_addrpolicy *
lookup_addrsel_policy(key)
struct sockaddr_in6 *key;
{
struct in6_addrpolicy *match = NULL;
ADDRSEL_LOCK();
match = match_addrsel_policy(key);
if (match == NULL)
match = &defaultaddrpolicy;
else
match->use++;
ADDRSEL_UNLOCK();
return (match);
}
/*
* Subroutines to manage the address selection policy table via sysctl.
*/
struct walkarg {
struct sysctl_req *w_req;
};
static int in6_src_sysctl(SYSCTL_HANDLER_ARGS);
SYSCTL_DECL(_net_inet6_ip6);
SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
CTLFLAG_RD, in6_src_sysctl, "");
static int
in6_src_sysctl(SYSCTL_HANDLER_ARGS)
{
struct walkarg w;
if (req->newptr)
return EPERM;
bzero(&w, sizeof(w));
w.w_req = req;
return (walk_addrsel_policy(dump_addrsel_policyent, &w));
}
int
in6_src_ioctl(cmd, data)
u_long cmd;
caddr_t data;
{
int i;
struct in6_addrpolicy ent0;
if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY)
return (EOPNOTSUPP); /* check for safety */
ent0 = *(struct in6_addrpolicy *)data;
if (ent0.label == ADDR_LABEL_NOTAPP)
return (EINVAL);
/* check if the prefix mask is consecutive. */
if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0)
return (EINVAL);
/* clear trailing garbages (if any) of the prefix address. */
for (i = 0; i < 4; i++) {
ent0.addr.sin6_addr.s6_addr32[i] &=
ent0.addrmask.sin6_addr.s6_addr32[i];
}
ent0.use = 0;
switch (cmd) {
case SIOCAADDRCTL_POLICY:
return (add_addrsel_policyent(&ent0));
case SIOCDADDRCTL_POLICY:
return (delete_addrsel_policyent(&ent0));
}
return (0); /* XXX: compromise compilers */
}
/*
* The followings are implementation of the policy table using a
* simple tail queue.
* XXX such details should be hidden.
* XXX implementation using binary tree should be more efficient.
*/
struct addrsel_policyent {
TAILQ_ENTRY(addrsel_policyent) ape_entry;
struct in6_addrpolicy ape_policy;
};
TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
struct addrsel_policyhead addrsel_policytab;
static void
init_policy_queue()
{
TAILQ_INIT(&addrsel_policytab);
}
static int
add_addrsel_policyent(newpolicy)
struct in6_addrpolicy *newpolicy;
{
struct addrsel_policyent *new, *pol;
MALLOC(new, struct addrsel_policyent *, sizeof(*new), M_IFADDR,
M_WAITOK);
ADDRSEL_XLOCK();
ADDRSEL_LOCK();
/* duplication check */
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if (SA6_ARE_ADDR_EQUAL(&newpolicy->addr,
&pol->ape_policy.addr) &&
SA6_ARE_ADDR_EQUAL(&newpolicy->addrmask,
&pol->ape_policy.addrmask)) {
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
FREE(new, M_IFADDR);
return (EEXIST); /* or override it? */
}
}
bzero(new, sizeof(*new));
/* XXX: should validate entry */
new->ape_policy = *newpolicy;
TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry);
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (0);
}
static int
delete_addrsel_policyent(key)
struct in6_addrpolicy *key;
{
struct addrsel_policyent *pol;
ADDRSEL_XLOCK();
ADDRSEL_LOCK();
/* search for the entry in the table */
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if (SA6_ARE_ADDR_EQUAL(&key->addr, &pol->ape_policy.addr) &&
SA6_ARE_ADDR_EQUAL(&key->addrmask,
&pol->ape_policy.addrmask)) {
break;
}
}
if (pol == NULL) {
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (ESRCH);
}
TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry);
ADDRSEL_UNLOCK();
ADDRSEL_XUNLOCK();
return (0);
}
static int
walk_addrsel_policy(callback, w)
int (*callback) __P((struct in6_addrpolicy *, void *));
void *w;
{
struct addrsel_policyent *pol;
int error = 0;
ADDRSEL_SLOCK();
TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
ADDRSEL_SUNLOCK();
return (error);
}
}
ADDRSEL_SUNLOCK();
return (error);
}
static int
dump_addrsel_policyent(pol, arg)
struct in6_addrpolicy *pol;
void *arg;
{
int error = 0;
struct walkarg *w = arg;
error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol));
return (error);
}
static struct in6_addrpolicy *
match_addrsel_policy(key)
struct sockaddr_in6 *key;
{
struct addrsel_policyent *pent;
struct in6_addrpolicy *bestpol = NULL, *pol;
int matchlen, bestmatchlen = -1;
u_char *mp, *ep, *k, *p, m;
TAILQ_FOREACH(pent, &addrsel_policytab, ape_entry) {
matchlen = 0;
pol = &pent->ape_policy;
mp = (u_char *)&pol->addrmask.sin6_addr;
ep = mp + 16; /* XXX: scope field? */
k = (u_char *)&key->sin6_addr;
p = (u_char *)&pol->addr.sin6_addr;
for (; mp < ep && *mp; mp++, k++, p++) {
m = *mp;
if ((*k & m) != *p)
goto next; /* not match */
if (m == 0xff) /* short cut for a typical case */
matchlen += 8;
else {
while (m >= 0x80) {
matchlen++;
m <<= 1;
}
}
}
/* matched. check if this is better than the current best. */
if (bestpol == NULL ||
matchlen > bestmatchlen) {
bestpol = pol;
bestmatchlen = matchlen;
}
next:
continue;
}
return (bestpol);
}
|