summaryrefslogtreecommitdiff
path: root/net/sctp/ipv6.c
blob: fc6c5e4bffa540069f70cf33bda2942d7143fcd4 (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
/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2002, 2004
 * Copyright (c) 2001 Nokia, Inc.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 * Copyright (c) 2002-2003 Intel Corp.
 *
 * This file is part of the SCTP kernel implementation
 *
 * SCTP over IPv6.
 *
 * This SCTP implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *		   ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    Le Yanqun		    <yanqun.le@nokia.com>
 *    Hui Huang		    <hui.huang@nokia.com>
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Sridhar Samudrala	    <sri@us.ibm.com>
 *    Jon Grimm		    <jgrimm@us.ibm.com>
 *    Ardelle Fan	    <ardelle.fan@intel.com>
 *
 * Based on:
 *	linux/net/ipv6/tcp_ipv6.c
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/ipsec.h>
#include <linux/slab.h>

#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/random.h>
#include <linux/seq_file.h>

#include <net/protocol.h>
#include <net/ndisc.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/transp_v6.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/inet_common.h>
#include <net/inet_ecn.h>
#include <net/sctp/sctp.h>

#include <linux/uaccess.h>

static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
					 union sctp_addr *s2);
static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
			      __be16 port);
static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
			    const union sctp_addr *addr2);

/* Event handler for inet6 address addition/deletion events.
 * The sctp_local_addr_list needs to be protocted by a spin lock since
 * multiple notifiers (say IPv4 and IPv6) may be running at the same
 * time and thus corrupt the list.
 * The reader side is protected with RCU.
 */
static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
				void *ptr)
{
	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
	struct sctp_sockaddr_entry *addr = NULL;
	struct sctp_sockaddr_entry *temp;
	struct net *net = dev_net(ifa->idev->dev);
	int found = 0;

	switch (ev) {
	case NETDEV_UP:
		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
		if (addr) {
			addr->a.v6.sin6_family = AF_INET6;
			addr->a.v6.sin6_port = 0;
			addr->a.v6.sin6_addr = ifa->addr;
			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
			addr->valid = 1;
			spin_lock_bh(&net->sctp.local_addr_lock);
			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
			spin_unlock_bh(&net->sctp.local_addr_lock);
		}
		break;
	case NETDEV_DOWN:
		spin_lock_bh(&net->sctp.local_addr_lock);
		list_for_each_entry_safe(addr, temp,
					&net->sctp.local_addr_list, list) {
			if (addr->a.sa.sa_family == AF_INET6 &&
					ipv6_addr_equal(&addr->a.v6.sin6_addr,
						&ifa->addr)) {
				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
				found = 1;
				addr->valid = 0;
				list_del_rcu(&addr->list);
				break;
			}
		}
		spin_unlock_bh(&net->sctp.local_addr_lock);
		if (found)
			kfree_rcu(addr, rcu);
		break;
	}

	return NOTIFY_DONE;
}

static struct notifier_block sctp_inet6addr_notifier = {
	.notifier_call = sctp_inet6addr_event,
};

/* ICMP error handler. */
static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			u8 type, u8 code, int offset, __be32 info)
{
	struct inet6_dev *idev;
	struct sock *sk;
	struct sctp_association *asoc;
	struct sctp_transport *transport;
	struct ipv6_pinfo *np;
	__u16 saveip, savesctp;
	int err;
	struct net *net = dev_net(skb->dev);

	idev = in6_dev_get(skb->dev);

	/* Fix up skb to look at the embedded net header. */
	saveip	 = skb->network_header;
	savesctp = skb->transport_header;
	skb_reset_network_header(skb);
	skb_set_transport_header(skb, offset);
	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
	/* Put back, the original pointers. */
	skb->network_header   = saveip;
	skb->transport_header = savesctp;
	if (!sk) {
		__ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
		goto out;
	}

	/* Warning:  The sock lock is held.  Remember to call
	 * sctp_err_finish!
	 */

	switch (type) {
	case ICMPV6_PKT_TOOBIG:
		if (ip6_sk_accept_pmtu(sk))
			sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
		goto out_unlock;
	case ICMPV6_PARAMPROB:
		if (ICMPV6_UNK_NEXTHDR == code) {
			sctp_icmp_proto_unreachable(sk, asoc, transport);
			goto out_unlock;
		}
		break;
	case NDISC_REDIRECT:
		sctp_icmp_redirect(sk, transport, skb);
		goto out_unlock;
	default:
		break;
	}

	np = inet6_sk(sk);
	icmpv6_err_convert(type, code, &err);
	if (!sock_owned_by_user(sk) && np->recverr) {
		sk->sk_err = err;
		sk->sk_error_report(sk);
	} else {  /* Only an error on timeout */
		sk->sk_err_soft = err;
	}

out_unlock:
	sctp_err_finish(sk, transport);
out:
	if (likely(idev != NULL))
		in6_dev_put(idev);
}

static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
{
	struct sock *sk = skb->sk;
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct flowi6 *fl6 = &transport->fl.u.ip6;
	__u8 tclass = np->tclass;
	int res;

	pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
		 skb->len, &fl6->saddr, &fl6->daddr);

	if (transport->dscp & SCTP_DSCP_SET_MASK)
		tclass = transport->dscp & SCTP_DSCP_VAL_MASK;

	if (INET_ECN_is_capable(tclass))
		IP6_ECN_flow_xmit(sk, fl6->flowlabel);

	if (!(transport->param_flags & SPP_PMTUD_ENABLE))
		skb->ignore_df = 1;

	SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);

	rcu_read_lock();
	res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
		       tclass);
	rcu_read_unlock();
	return res;
}

/* Returns the dst cache entry for the given source and destination ip
 * addresses.
 */
static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
			    struct flowi *fl, struct sock *sk)
{
	struct sctp_association *asoc = t->asoc;
	struct dst_entry *dst = NULL;
	struct flowi6 *fl6 = &fl->u.ip6;
	struct sctp_bind_addr *bp;
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct sctp_sockaddr_entry *laddr;
	union sctp_addr *daddr = &t->ipaddr;
	union sctp_addr dst_saddr;
	struct in6_addr *final_p, final;
	enum sctp_scope scope;
	__u8 matchlen = 0;

	memset(fl6, 0, sizeof(struct flowi6));
	fl6->daddr = daddr->v6.sin6_addr;
	fl6->fl6_dport = daddr->v6.sin6_port;
	fl6->flowi6_proto = IPPROTO_SCTP;
	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
		fl6->flowi6_oif = daddr->v6.sin6_scope_id;
	else if (asoc)
		fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
	if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
		fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);

	if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
		struct ip6_flowlabel *flowlabel;

		flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
		if (!flowlabel)
			goto out;
		fl6_sock_release(flowlabel);
	}

	pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);

	if (asoc)
		fl6->fl6_sport = htons(asoc->base.bind_addr.port);

	if (saddr) {
		fl6->saddr = saddr->v6.sin6_addr;
		fl6->fl6_sport = saddr->v6.sin6_port;

		pr_debug("src=%pI6 - ", &fl6->saddr);
	}

	rcu_read_lock();
	final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
	rcu_read_unlock();

	dst = ip6_dst_lookup_flow(sk, fl6, final_p);
	if (!asoc || saddr)
		goto out;

	bp = &asoc->base.bind_addr;
	scope = sctp_scope(daddr);
	/* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
	 * to see if we can use it.
	 */
	if (!IS_ERR(dst)) {
		/* Walk through the bind address list and look for a bind
		 * address that matches the source address of the returned dst.
		 */
		sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
		rcu_read_lock();
		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
			if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
			    (laddr->state != SCTP_ADDR_SRC &&
			     !asoc->src_out_of_asoc_ok))
				continue;

			/* Do not compare against v4 addrs */
			if ((laddr->a.sa.sa_family == AF_INET6) &&
			    (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
				rcu_read_unlock();
				goto out;
			}
		}
		rcu_read_unlock();
		/* None of the bound addresses match the source address of the
		 * dst. So release it.
		 */
		dst_release(dst);
		dst = NULL;
	}

	/* Walk through the bind address list and try to get the
	 * best source address for a given destination.
	 */
	rcu_read_lock();
	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
		struct dst_entry *bdst;
		__u8 bmatchlen;

		if (!laddr->valid ||
		    laddr->state != SCTP_ADDR_SRC ||
		    laddr->a.sa.sa_family != AF_INET6 ||
		    scope > sctp_scope(&laddr->a))
			continue;

		fl6->saddr = laddr->a.v6.sin6_addr;
		fl6->fl6_sport = laddr->a.v6.sin6_port;
		final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
		bdst = ip6_dst_lookup_flow(sk, fl6, final_p);

		if (IS_ERR(bdst))
			continue;

		if (ipv6_chk_addr(dev_net(bdst->dev),
				  &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
			if (!IS_ERR_OR_NULL(dst))
				dst_release(dst);
			dst = bdst;
			break;
		}

		bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
		if (matchlen > bmatchlen) {
			dst_release(bdst);
			continue;
		}

		if (!IS_ERR_OR_NULL(dst))
			dst_release(dst);
		dst = bdst;
		matchlen = bmatchlen;
	}
	rcu_read_unlock();

out:
	if (!IS_ERR_OR_NULL(dst)) {
		struct rt6_info *rt;

		rt = (struct rt6_info *)dst;
		t->dst = dst;
		t->dst_cookie = rt6_get_cookie(rt);
		pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
			 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
			 &fl6->saddr);
	} else {
		t->dst = NULL;

		pr_debug("no route\n");
	}
}

/* Returns the number of consecutive initial bits that match in the 2 ipv6
 * addresses.
 */
static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
					 union sctp_addr *s2)
{
	return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
}

/* Fills in the source address(saddr) based on the destination address(daddr)
 * and asoc's bind address list.
 */
static void sctp_v6_get_saddr(struct sctp_sock *sk,
			      struct sctp_transport *t,
			      struct flowi *fl)
{
	struct flowi6 *fl6 = &fl->u.ip6;
	union sctp_addr *saddr = &t->saddr;

	pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);

	if (t->dst) {
		saddr->v6.sin6_family = AF_INET6;
		saddr->v6.sin6_addr = fl6->saddr;
	}
}

/* Make a copy of all potential local addresses. */
static void sctp_v6_copy_addrlist(struct list_head *addrlist,
				  struct net_device *dev)
{
	struct inet6_dev *in6_dev;
	struct inet6_ifaddr *ifp;
	struct sctp_sockaddr_entry *addr;

	rcu_read_lock();
	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
		rcu_read_unlock();
		return;
	}

	read_lock_bh(&in6_dev->lock);
	list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
		/* Add the address to the local list.  */
		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
		if (addr) {
			addr->a.v6.sin6_family = AF_INET6;
			addr->a.v6.sin6_port = 0;
			addr->a.v6.sin6_addr = ifp->addr;
			addr->a.v6.sin6_scope_id = dev->ifindex;
			addr->valid = 1;
			INIT_LIST_HEAD(&addr->list);
			list_add_tail(&addr->list, addrlist);
		}
	}

	read_unlock_bh(&in6_dev->lock);
	rcu_read_unlock();
}

/* Copy over any ip options */
static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
{
	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
	struct ipv6_txoptions *opt;

	newnp = inet6_sk(newsk);

	rcu_read_lock();
	opt = rcu_dereference(np->opt);
	if (opt) {
		opt = ipv6_dup_options(newsk, opt);
		if (!opt)
			pr_err("%s: Failed to copy ip options\n", __func__);
	}
	RCU_INIT_POINTER(newnp->opt, opt);
	rcu_read_unlock();
}

/* Account for the IP options */
static int sctp_v6_ip_options_len(struct sock *sk)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct ipv6_txoptions *opt;
	int len = 0;

	rcu_read_lock();
	opt = rcu_dereference(np->opt);
	if (opt)
		len = opt->opt_flen + opt->opt_nflen;

	rcu_read_unlock();
	return len;
}

/* Initialize a sockaddr_storage from in incoming skb. */
static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
			     int is_saddr)
{
	/* Always called on head skb, so this is safe */
	struct sctphdr *sh = sctp_hdr(skb);
	struct sockaddr_in6 *sa = &addr->v6;

	addr->v6.sin6_family = AF_INET6;
	addr->v6.sin6_flowinfo = 0; /* FIXME */
	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;

	if (is_saddr) {
		sa->sin6_port = sh->source;
		sa->sin6_addr = ipv6_hdr(skb)->saddr;
	} else {
		sa->sin6_port = sh->dest;
		sa->sin6_addr = ipv6_hdr(skb)->daddr;
	}
}

/* Initialize an sctp_addr from a socket. */
static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
{
	addr->v6.sin6_family = AF_INET6;
	addr->v6.sin6_port = 0;
	addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
}

/* Initialize sk->sk_rcv_saddr from sctp_addr. */
static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
{
	if (addr->sa.sa_family == AF_INET) {
		sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
		sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
		sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
		sk->sk_v6_rcv_saddr.s6_addr32[3] =
			addr->v4.sin_addr.s_addr;
	} else {
		sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
	}
}

/* Initialize sk->sk_daddr from sctp_addr. */
static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
{
	if (addr->sa.sa_family == AF_INET) {
		sk->sk_v6_daddr.s6_addr32[0] = 0;
		sk->sk_v6_daddr.s6_addr32[1] = 0;
		sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
		sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
	} else {
		sk->sk_v6_daddr = addr->v6.sin6_addr;
	}
}

/* Initialize a sctp_addr from an address parameter. */
static void sctp_v6_from_addr_param(union sctp_addr *addr,
				    union sctp_addr_param *param,
				    __be16 port, int iif)
{
	addr->v6.sin6_family = AF_INET6;
	addr->v6.sin6_port = port;
	addr->v6.sin6_flowinfo = 0; /* BUG */
	addr->v6.sin6_addr = param->v6.addr;
	addr->v6.sin6_scope_id = iif;
}

/* Initialize an address parameter from a sctp_addr and return the length
 * of the address parameter.
 */
static int sctp_v6_to_addr_param(const union sctp_addr *addr,
				 union sctp_addr_param *param)
{
	int length = sizeof(struct sctp_ipv6addr_param);

	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
	param->v6.param_hdr.length = htons(length);
	param->v6.addr = addr->v6.sin6_addr;

	return length;
}

/* Initialize a sctp_addr from struct in6_addr. */
static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
			      __be16 port)
{
	addr->sa.sa_family = AF_INET6;
	addr->v6.sin6_port = port;
	addr->v6.sin6_flowinfo = 0;
	addr->v6.sin6_addr = *saddr;
	addr->v6.sin6_scope_id = 0;
}

static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
			      const union sctp_addr *addr2)
{
	if (addr1->sa.sa_family != addr2->sa.sa_family) {
		if (addr1->sa.sa_family == AF_INET &&
		    addr2->sa.sa_family == AF_INET6 &&
		    ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
		    addr2->v6.sin6_addr.s6_addr32[3] ==
		    addr1->v4.sin_addr.s_addr)
			return 1;

		if (addr2->sa.sa_family == AF_INET &&
		    addr1->sa.sa_family == AF_INET6 &&
		    ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
		    addr1->v6.sin6_addr.s6_addr32[3] ==
		    addr2->v4.sin_addr.s_addr)
			return 1;

		return 0;
	}

	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
		return 0;

	/* If this is a linklocal address, compare the scope_id. */
	if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
	    addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
	    addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
		return 0;

	return 1;
}

/* Compare addresses exactly.
 * v4-mapped-v6 is also in consideration.
 */
static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
			    const union sctp_addr *addr2)
{
	return __sctp_v6_cmp_addr(addr1, addr2) &&
	       addr1->v6.sin6_port == addr2->v6.sin6_port;
}

/* Initialize addr struct to INADDR_ANY. */
static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
{
	memset(addr, 0x00, sizeof(union sctp_addr));
	addr->v6.sin6_family = AF_INET6;
	addr->v6.sin6_port = port;
}

/* Is this a wildcard address? */
static int sctp_v6_is_any(const union sctp_addr *addr)
{
	return ipv6_addr_any(&addr->v6.sin6_addr);
}

/* Should this be available for binding?   */
static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
{
	int type;
	struct net *net = sock_net(&sp->inet.sk);
	const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;

	type = ipv6_addr_type(in6);
	if (IPV6_ADDR_ANY == type)
		return 1;
	if (type == IPV6_ADDR_MAPPED) {
		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
			return 0;
		sctp_v6_map_v4(addr);
		return sctp_get_af_specific(AF_INET)->available(addr, sp);
	}
	if (!(type & IPV6_ADDR_UNICAST))
		return 0;

	return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
		ipv6_chk_addr(net, in6, NULL, 0);
}

/* This function checks if the address is a valid address to be used for
 * SCTP.
 *
 * Output:
 * Return 0 - If the address is a non-unicast or an illegal address.
 * Return 1 - If the address is a unicast.
 */
static int sctp_v6_addr_valid(union sctp_addr *addr,
			      struct sctp_sock *sp,
			      const struct sk_buff *skb)
{
	int ret = ipv6_addr_type(&addr->v6.sin6_addr);

	/* Support v4-mapped-v6 address. */
	if (ret == IPV6_ADDR_MAPPED) {
		/* Note: This routine is used in input, so v4-mapped-v6
		 * are disallowed here when there is no sctp_sock.
		 */
		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
			return 0;
		sctp_v6_map_v4(addr);
		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
	}

	/* Is this a non-unicast address */
	if (!(ret & IPV6_ADDR_UNICAST))
		return 0;

	return 1;
}

/* What is the scope of 'addr'?  */
static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
{
	enum sctp_scope retval;
	int v6scope;

	/* The IPv6 scope is really a set of bit fields.
	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
	 */

	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
	switch (v6scope) {
	case IFA_HOST:
		retval = SCTP_SCOPE_LOOPBACK;
		break;
	case IFA_LINK:
		retval = SCTP_SCOPE_LINK;
		break;
	case IFA_SITE:
		retval = SCTP_SCOPE_PRIVATE;
		break;
	default:
		retval = SCTP_SCOPE_GLOBAL;
		break;
	}

	return retval;
}

/* Create and initialize a new sk for the socket to be returned by accept(). */
static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
					     struct sctp_association *asoc,
					     bool kern)
{
	struct sock *newsk;
	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
	struct sctp6_sock *newsctp6sk;

	newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
	if (!newsk)
		goto out;

	sock_init_data(NULL, newsk);

	sctp_copy_sock(newsk, sk, asoc);
	sock_reset_flag(sk, SOCK_ZAPPED);

	newsctp6sk = (struct sctp6_sock *)newsk;
	inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;

	sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;

	newnp = inet6_sk(newsk);

	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
	newnp->ipv6_mc_list = NULL;
	newnp->ipv6_ac_list = NULL;
	newnp->ipv6_fl_list = NULL;

	sctp_v6_copy_ip_options(sk, newsk);

	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
	 * and getpeername().
	 */
	sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);

	newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;

	sk_refcnt_debug_inc(newsk);

	if (newsk->sk_prot->init(newsk)) {
		sk_common_release(newsk);
		newsk = NULL;
	}

out:
	return newsk;
}

/* Format a sockaddr for return to user space. This makes sure the return is
 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 */
static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
{
	if (sp->v4mapped) {
		if (addr->sa.sa_family == AF_INET)
			sctp_v4_map_v6(addr);
	} else {
		if (addr->sa.sa_family == AF_INET6 &&
		    ipv6_addr_v4mapped(&addr->v6.sin6_addr))
			sctp_v6_map_v4(addr);
	}

	if (addr->sa.sa_family == AF_INET) {
		memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
		return sizeof(struct sockaddr_in);
	}
	return sizeof(struct sockaddr_in6);
}

/* Where did this skb come from?  */
static int sctp_v6_skb_iif(const struct sk_buff *skb)
{
	return IP6CB(skb)->iif;
}

/* Was this packet marked by Explicit Congestion Notification? */
static int sctp_v6_is_ce(const struct sk_buff *skb)
{
	return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
}

/* Dump the v6 addr to the seq file. */
static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
{
	seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
}

static void sctp_v6_ecn_capable(struct sock *sk)
{
	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
}

/* Initialize a PF_INET msgname from a ulpevent. */
static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
				     char *msgname, int *addrlen)
{
	union sctp_addr *addr;
	struct sctp_association *asoc;
	union sctp_addr *paddr;

	if (!msgname)
		return;

	addr = (union sctp_addr *)msgname;
	asoc = event->asoc;
	paddr = &asoc->peer.primary_addr;

	if (paddr->sa.sa_family == AF_INET) {
		addr->v4.sin_family = AF_INET;
		addr->v4.sin_port = htons(asoc->peer.port);
		addr->v4.sin_addr = paddr->v4.sin_addr;
	} else {
		addr->v6.sin6_family = AF_INET6;
		addr->v6.sin6_flowinfo = 0;
		if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
			addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
		else
			addr->v6.sin6_scope_id = 0;
		addr->v6.sin6_port = htons(asoc->peer.port);
		addr->v6.sin6_addr = paddr->v6.sin6_addr;
	}

	*addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
}

/* Initialize a msg_name from an inbound skb. */
static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
				   int *addr_len)
{
	union sctp_addr *addr;
	struct sctphdr *sh;

	if (!msgname)
		return;

	addr = (union sctp_addr *)msgname;
	sh = sctp_hdr(skb);

	if (ip_hdr(skb)->version == 4) {
		addr->v4.sin_family = AF_INET;
		addr->v4.sin_port = sh->source;
		addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
	} else {
		addr->v6.sin6_family = AF_INET6;
		addr->v6.sin6_flowinfo = 0;
		addr->v6.sin6_port = sh->source;
		addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
		if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
			addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
		else
			addr->v6.sin6_scope_id = 0;
	}

	*addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
}

/* Do we support this AF? */
static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
{
	switch (family) {
	case AF_INET6:
		return 1;
	/* v4-mapped-v6 addresses */
	case AF_INET:
		if (!__ipv6_only_sock(sctp_opt2sk(sp)))
			return 1;
		/* fallthru */
	default:
		return 0;
	}
}

/* Address matching with wildcards allowed.  This extra level
 * of indirection lets us choose whether a PF_INET6 should
 * disallow any v4 addresses if we so choose.
 */
static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
			       const union sctp_addr *addr2,
			       struct sctp_sock *opt)
{
	struct sock *sk = sctp_opt2sk(opt);
	struct sctp_af *af1, *af2;

	af1 = sctp_get_af_specific(addr1->sa.sa_family);
	af2 = sctp_get_af_specific(addr2->sa.sa_family);

	if (!af1 || !af2)
		return 0;

	/* If the socket is IPv6 only, v4 addrs will not match */
	if (__ipv6_only_sock(sk) && af1 != af2)
		return 0;

	/* Today, wildcard AF_INET/AF_INET6. */
	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
		return 1;

	if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
		return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;

	return __sctp_v6_cmp_addr(addr1, addr2);
}

/* Verify that the provided sockaddr looks bindable.   Common verification,
 * has already been taken care of.
 */
static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
{
	struct sctp_af *af;

	/* ASSERT: address family has already been verified. */
	if (addr->sa.sa_family != AF_INET6)
		af = sctp_get_af_specific(addr->sa.sa_family);
	else {
		int type = ipv6_addr_type(&addr->v6.sin6_addr);
		struct net_device *dev;

		if (type & IPV6_ADDR_LINKLOCAL) {
			struct net *net;
			if (!addr->v6.sin6_scope_id)
				return 0;
			net = sock_net(&opt->inet.sk);
			rcu_read_lock();
			dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
			if (!dev || !(opt->inet.freebind ||
				      net->ipv6.sysctl.ip_nonlocal_bind ||
				      ipv6_chk_addr(net, &addr->v6.sin6_addr,
						    dev, 0))) {
				rcu_read_unlock();
				return 0;
			}
			rcu_read_unlock();
		}

		af = opt->pf->af;
	}
	return af->available(addr, opt);
}

/* Verify that the provided sockaddr looks sendable.   Common verification,
 * has already been taken care of.
 */
static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
{
	struct sctp_af *af = NULL;

	/* ASSERT: address family has already been verified. */
	if (addr->sa.sa_family != AF_INET6)
		af = sctp_get_af_specific(addr->sa.sa_family);
	else {
		int type = ipv6_addr_type(&addr->v6.sin6_addr);
		struct net_device *dev;

		if (type & IPV6_ADDR_LINKLOCAL) {
			if (!addr->v6.sin6_scope_id)
				return 0;
			rcu_read_lock();
			dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
						   addr->v6.sin6_scope_id);
			rcu_read_unlock();
			if (!dev)
				return 0;
		}
		af = opt->pf->af;
	}

	return af != NULL;
}

/* Fill in Supported Address Type information for INIT and INIT-ACK
 * chunks.   Note: In the future, we may want to look at sock options
 * to determine whether a PF_INET6 socket really wants to have IPV4
 * addresses.
 * Returns number of addresses supported.
 */
static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
				      __be16 *types)
{
	types[0] = SCTP_PARAM_IPV6_ADDRESS;
	if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
		types[1] = SCTP_PARAM_IPV4_ADDRESS;
		return 2;
	}
	return 1;
}

/* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
			int peer)
{
	int rc;

	rc = inet6_getname(sock, uaddr, peer);

	if (rc < 0)
		return rc;

	rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
					  (union sctp_addr *)uaddr);

	return rc;
}

static const struct proto_ops inet6_seqpacket_ops = {
	.family		   = PF_INET6,
	.owner		   = THIS_MODULE,
	.release	   = inet6_release,
	.bind		   = inet6_bind,
	.connect	   = sctp_inet_connect,
	.socketpair	   = sock_no_socketpair,
	.accept		   = inet_accept,
	.getname	   = sctp_getname,
	.poll		   = sctp_poll,
	.ioctl		   = inet6_ioctl,
	.listen		   = sctp_inet_listen,
	.shutdown	   = inet_shutdown,
	.setsockopt	   = sock_common_setsockopt,
	.getsockopt	   = sock_common_getsockopt,
	.sendmsg	   = inet_sendmsg,
	.recvmsg	   = inet_recvmsg,
	.mmap		   = sock_no_mmap,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_sock_common_setsockopt,
	.compat_getsockopt = compat_sock_common_getsockopt,
#endif
};

static struct inet_protosw sctpv6_seqpacket_protosw = {
	.type          = SOCK_SEQPACKET,
	.protocol      = IPPROTO_SCTP,
	.prot 	       = &sctpv6_prot,
	.ops           = &inet6_seqpacket_ops,
	.flags         = SCTP_PROTOSW_FLAG
};
static struct inet_protosw sctpv6_stream_protosw = {
	.type          = SOCK_STREAM,
	.protocol      = IPPROTO_SCTP,
	.prot 	       = &sctpv6_prot,
	.ops           = &inet6_seqpacket_ops,
	.flags         = SCTP_PROTOSW_FLAG,
};

static int sctp6_rcv(struct sk_buff *skb)
{
	return sctp_rcv(skb) ? -1 : 0;
}

static const struct inet6_protocol sctpv6_protocol = {
	.handler      = sctp6_rcv,
	.err_handler  = sctp_v6_err,
	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
};

static struct sctp_af sctp_af_inet6 = {
	.sa_family	   = AF_INET6,
	.sctp_xmit	   = sctp_v6_xmit,
	.setsockopt	   = ipv6_setsockopt,
	.getsockopt	   = ipv6_getsockopt,
	.get_dst	   = sctp_v6_get_dst,
	.get_saddr	   = sctp_v6_get_saddr,
	.copy_addrlist	   = sctp_v6_copy_addrlist,
	.from_skb	   = sctp_v6_from_skb,
	.from_sk	   = sctp_v6_from_sk,
	.from_addr_param   = sctp_v6_from_addr_param,
	.to_addr_param	   = sctp_v6_to_addr_param,
	.cmp_addr	   = sctp_v6_cmp_addr,
	.scope		   = sctp_v6_scope,
	.addr_valid	   = sctp_v6_addr_valid,
	.inaddr_any	   = sctp_v6_inaddr_any,
	.is_any		   = sctp_v6_is_any,
	.available	   = sctp_v6_available,
	.skb_iif	   = sctp_v6_skb_iif,
	.is_ce		   = sctp_v6_is_ce,
	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
	.ecn_capable	   = sctp_v6_ecn_capable,
	.net_header_len	   = sizeof(struct ipv6hdr),
	.sockaddr_len	   = sizeof(struct sockaddr_in6),
	.ip_options_len	   = sctp_v6_ip_options_len,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_ipv6_setsockopt,
	.compat_getsockopt = compat_ipv6_getsockopt,
#endif
};

static struct sctp_pf sctp_pf_inet6 = {
	.event_msgname = sctp_inet6_event_msgname,
	.skb_msgname   = sctp_inet6_skb_msgname,
	.af_supported  = sctp_inet6_af_supported,
	.cmp_addr      = sctp_inet6_cmp_addr,
	.bind_verify   = sctp_inet6_bind_verify,
	.send_verify   = sctp_inet6_send_verify,
	.supported_addrs = sctp_inet6_supported_addrs,
	.create_accept_sk = sctp_v6_create_accept_sk,
	.addr_to_user  = sctp_v6_addr_to_user,
	.to_sk_saddr   = sctp_v6_to_sk_saddr,
	.to_sk_daddr   = sctp_v6_to_sk_daddr,
	.copy_ip_options = sctp_v6_copy_ip_options,
	.af            = &sctp_af_inet6,
};

/* Initialize IPv6 support and register with socket layer.  */
void sctp_v6_pf_init(void)
{
	/* Register the SCTP specific PF_INET6 functions. */
	sctp_register_pf(&sctp_pf_inet6, PF_INET6);

	/* Register the SCTP specific AF_INET6 functions. */
	sctp_register_af(&sctp_af_inet6);
}

void sctp_v6_pf_exit(void)
{
	list_del(&sctp_af_inet6.list);
}

/* Initialize IPv6 support and register with socket layer.  */
int sctp_v6_protosw_init(void)
{
	int rc;

	rc = proto_register(&sctpv6_prot, 1);
	if (rc)
		return rc;

	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
	inet6_register_protosw(&sctpv6_seqpacket_protosw);
	inet6_register_protosw(&sctpv6_stream_protosw);

	return 0;
}

void sctp_v6_protosw_exit(void)
{
	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
	inet6_unregister_protosw(&sctpv6_stream_protosw);
	proto_unregister(&sctpv6_prot);
}


/* Register with inet6 layer. */
int sctp_v6_add_protocol(void)
{
	/* Register notifier for inet6 address additions/deletions. */
	register_inet6addr_notifier(&sctp_inet6addr_notifier);

	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
		return -EAGAIN;

	return 0;
}

/* Unregister with inet6 layer. */
void sctp_v6_del_protocol(void)
{
	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
}