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50
51#include <linux/types.h>
52#include <linux/list.h>
53#include <linux/socket.h>
54#include <linux/ip.h>
55#include <linux/time.h>
56#include <net/ip.h>
57#include <net/icmp.h>
58#include <net/snmp.h>
59#include <net/sock.h>
60#include <net/xfrm.h>
61#include <net/sctp/sctp.h>
62#include <net/sctp/sm.h>
63
64
65static int sctp_rcv_ootb(struct sk_buff *);
66static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
67 const union sctp_addr *laddr,
68 const union sctp_addr *paddr,
69 struct sctp_transport **transportp);
70static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr);
71static struct sctp_association *__sctp_lookup_association(
72 const union sctp_addr *local,
73 const union sctp_addr *peer,
74 struct sctp_transport **pt);
75
76static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb);
77
78
79
80static inline int sctp_rcv_checksum(struct sk_buff *skb)
81{
82 struct sk_buff *list = skb_shinfo(skb)->frag_list;
83 struct sctphdr *sh = sctp_hdr(skb);
84 __u32 cmp = ntohl(sh->checksum);
85 __u32 val = sctp_start_cksum((__u8 *)sh, skb_headlen(skb));
86
87 for (; list; list = list->next)
88 val = sctp_update_cksum((__u8 *)list->data, skb_headlen(list),
89 val);
90
91 val = sctp_end_cksum(val);
92
93 if (val != cmp) {
94
95 SCTP_INC_STATS_BH(SCTP_MIB_CHECKSUMERRORS);
96 return -1;
97 }
98 return 0;
99}
100
101struct sctp_input_cb {
102 union {
103 struct inet_skb_parm h4;
104#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
105 struct inet6_skb_parm h6;
106#endif
107 } header;
108 struct sctp_chunk *chunk;
109};
110#define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
111
112
113
114
115int sctp_rcv(struct sk_buff *skb)
116{
117 struct sock *sk;
118 struct sctp_association *asoc;
119 struct sctp_endpoint *ep = NULL;
120 struct sctp_ep_common *rcvr;
121 struct sctp_transport *transport = NULL;
122 struct sctp_chunk *chunk;
123 struct sctphdr *sh;
124 union sctp_addr src;
125 union sctp_addr dest;
126 int family;
127 struct sctp_af *af;
128
129 if (skb->pkt_type!=PACKET_HOST)
130 goto discard_it;
131
132 SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS);
133
134 if (skb_linearize(skb))
135 goto discard_it;
136
137 sh = sctp_hdr(skb);
138
139
140 __skb_pull(skb, skb_transport_offset(skb));
141 if (skb->len < sizeof(struct sctphdr))
142 goto discard_it;
143 if (!skb_csum_unnecessary(skb) && sctp_rcv_checksum(skb) < 0)
144 goto discard_it;
145
146 skb_pull(skb, sizeof(struct sctphdr));
147
148
149 if (skb->len < sizeof(struct sctp_chunkhdr))
150 goto discard_it;
151
152 family = ipver2af(ip_hdr(skb)->version);
153 af = sctp_get_af_specific(family);
154 if (unlikely(!af))
155 goto discard_it;
156
157
158 af->from_skb(&src, skb, 1);
159 af->from_skb(&dest, skb, 0);
160
161
162
163
164
165
166
167
168
169
170
171
172 if (!af->addr_valid(&src, NULL, skb) ||
173 !af->addr_valid(&dest, NULL, skb))
174 goto discard_it;
175
176 asoc = __sctp_rcv_lookup(skb, &src, &dest, &transport);
177
178 if (!asoc)
179 ep = __sctp_rcv_lookup_endpoint(&dest);
180
181
182 rcvr = asoc ? &asoc->base : &ep->base;
183 sk = rcvr->sk;
184
185
186
187
188
189 if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb)))
190 {
191 if (asoc) {
192 sctp_association_put(asoc);
193 asoc = NULL;
194 } else {
195 sctp_endpoint_put(ep);
196 ep = NULL;
197 }
198 sk = sctp_get_ctl_sock();
199 ep = sctp_sk(sk)->ep;
200 sctp_endpoint_hold(ep);
201 rcvr = &ep->base;
202 }
203
204
205
206
207
208
209
210
211
212 if (!asoc) {
213 if (sctp_rcv_ootb(skb)) {
214 SCTP_INC_STATS_BH(SCTP_MIB_OUTOFBLUES);
215 goto discard_release;
216 }
217 }
218
219 if (!xfrm_policy_check(sk, XFRM_POLICY_IN, skb, family))
220 goto discard_release;
221 nf_reset(skb);
222
223 if (sk_filter(sk, skb))
224 goto discard_release;
225
226
227 chunk = sctp_chunkify(skb, asoc, sk);
228 if (!chunk)
229 goto discard_release;
230 SCTP_INPUT_CB(skb)->chunk = chunk;
231
232
233 chunk->rcvr = rcvr;
234
235
236 chunk->sctp_hdr = sh;
237
238
239 sctp_init_addrs(chunk, &src, &dest);
240
241
242 chunk->transport = transport;
243
244
245
246
247
248 sctp_bh_lock_sock(sk);
249
250 if (sock_owned_by_user(sk)) {
251 SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_BACKLOG);
252 sctp_add_backlog(sk, skb);
253 } else {
254 SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_SOFTIRQ);
255 sctp_inq_push(&chunk->rcvr->inqueue, chunk);
256 }
257
258 sctp_bh_unlock_sock(sk);
259
260
261 if (asoc)
262 sctp_association_put(asoc);
263 else
264 sctp_endpoint_put(ep);
265
266 return 0;
267
268discard_it:
269 SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_DISCARDS);
270 kfree_skb(skb);
271 return 0;
272
273discard_release:
274
275 if (asoc)
276 sctp_association_put(asoc);
277 else
278 sctp_endpoint_put(ep);
279
280 goto discard_it;
281}
282
283
284
285
286
287
288int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
289{
290 struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
291 struct sctp_inq *inqueue = &chunk->rcvr->inqueue;
292 struct sctp_ep_common *rcvr = NULL;
293 int backloged = 0;
294
295 rcvr = chunk->rcvr;
296
297
298
299
300
301 if (rcvr->dead) {
302 sctp_chunk_free(chunk);
303 goto done;
304 }
305
306 if (unlikely(rcvr->sk != sk)) {
307
308
309
310
311
312
313
314
315
316
317
318 sk = rcvr->sk;
319 sctp_bh_lock_sock(sk);
320
321 if (sock_owned_by_user(sk)) {
322 sk_add_backlog(sk, skb);
323 backloged = 1;
324 } else
325 sctp_inq_push(inqueue, chunk);
326
327 sctp_bh_unlock_sock(sk);
328
329
330 if (backloged)
331 return 0;
332 } else {
333 sctp_inq_push(inqueue, chunk);
334 }
335
336done:
337
338 if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
339 sctp_association_put(sctp_assoc(rcvr));
340 else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
341 sctp_endpoint_put(sctp_ep(rcvr));
342 else
343 BUG();
344
345 return 0;
346}
347
348static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb)
349{
350 struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
351 struct sctp_ep_common *rcvr = chunk->rcvr;
352
353
354
355
356 if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
357 sctp_association_hold(sctp_assoc(rcvr));
358 else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
359 sctp_endpoint_hold(sctp_ep(rcvr));
360 else
361 BUG();
362
363 sk_add_backlog(sk, skb);
364}
365
366
367void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
368 struct sctp_transport *t, __u32 pmtu)
369{
370 if (!t || (t->pathmtu == pmtu))
371 return;
372
373 if (sock_owned_by_user(sk)) {
374 asoc->pmtu_pending = 1;
375 t->pmtu_pending = 1;
376 return;
377 }
378
379 if (t->param_flags & SPP_PMTUD_ENABLE) {
380
381 sctp_transport_update_pmtu(t, pmtu);
382
383
384 sctp_assoc_sync_pmtu(asoc);
385 }
386
387
388
389
390
391
392
393 sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
394}
395
396
397
398
399
400
401
402
403
404
405
406
407void sctp_icmp_proto_unreachable(struct sock *sk,
408 struct sctp_association *asoc,
409 struct sctp_transport *t)
410{
411 SCTP_DEBUG_PRINTK("%s\n", __FUNCTION__);
412
413 sctp_do_sm(SCTP_EVENT_T_OTHER,
414 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
415 asoc->state, asoc->ep, asoc, t,
416 GFP_ATOMIC);
417
418}
419
420
421struct sock *sctp_err_lookup(int family, struct sk_buff *skb,
422 struct sctphdr *sctphdr,
423 struct sctp_association **app,
424 struct sctp_transport **tpp)
425{
426 union sctp_addr saddr;
427 union sctp_addr daddr;
428 struct sctp_af *af;
429 struct sock *sk = NULL;
430 struct sctp_association *asoc;
431 struct sctp_transport *transport = NULL;
432
433 *app = NULL; *tpp = NULL;
434
435 af = sctp_get_af_specific(family);
436 if (unlikely(!af)) {
437 return NULL;
438 }
439
440
441 af->from_skb(&saddr, skb, 1);
442 af->from_skb(&daddr, skb, 0);
443
444
445
446
447 asoc = __sctp_lookup_association(&saddr, &daddr, &transport);
448 if (!asoc)
449 return NULL;
450
451 sk = asoc->base.sk;
452
453 if (ntohl(sctphdr->vtag) != asoc->c.peer_vtag) {
454 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
455 goto out;
456 }
457
458 sctp_bh_lock_sock(sk);
459
460
461
462
463 if (sock_owned_by_user(sk))
464 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
465
466 *app = asoc;
467 *tpp = transport;
468 return sk;
469
470out:
471 if (asoc)
472 sctp_association_put(asoc);
473 return NULL;
474}
475
476
477void sctp_err_finish(struct sock *sk, struct sctp_association *asoc)
478{
479 sctp_bh_unlock_sock(sk);
480 if (asoc)
481 sctp_association_put(asoc);
482}
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499void sctp_v4_err(struct sk_buff *skb, __u32 info)
500{
501 struct iphdr *iph = (struct iphdr *)skb->data;
502 const int ihlen = iph->ihl * 4;
503 const int type = icmp_hdr(skb)->type;
504 const int code = icmp_hdr(skb)->code;
505 struct sock *sk;
506 struct sctp_association *asoc = NULL;
507 struct sctp_transport *transport;
508 struct inet_sock *inet;
509 sk_buff_data_t saveip, savesctp;
510 int err;
511
512 if (skb->len < ihlen + 8) {
513 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
514 return;
515 }
516
517
518 saveip = skb->network_header;
519 savesctp = skb->transport_header;
520 skb_reset_network_header(skb);
521 skb_set_transport_header(skb, ihlen);
522 sk = sctp_err_lookup(AF_INET, skb, sctp_hdr(skb), &asoc, &transport);
523
524 skb->network_header = saveip;
525 skb->transport_header = savesctp;
526 if (!sk) {
527 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
528 return;
529 }
530
531
532
533
534 switch (type) {
535 case ICMP_PARAMETERPROB:
536 err = EPROTO;
537 break;
538 case ICMP_DEST_UNREACH:
539 if (code > NR_ICMP_UNREACH)
540 goto out_unlock;
541
542
543 if (ICMP_FRAG_NEEDED == code) {
544 sctp_icmp_frag_needed(sk, asoc, transport, info);
545 goto out_unlock;
546 }
547 else {
548 if (ICMP_PROT_UNREACH == code) {
549 sctp_icmp_proto_unreachable(sk, asoc,
550 transport);
551 goto out_unlock;
552 }
553 }
554 err = icmp_err_convert[code].errno;
555 break;
556 case ICMP_TIME_EXCEEDED:
557
558
559
560 if (ICMP_EXC_FRAGTIME == code)
561 goto out_unlock;
562
563 err = EHOSTUNREACH;
564 break;
565 default:
566 goto out_unlock;
567 }
568
569 inet = inet_sk(sk);
570 if (!sock_owned_by_user(sk) && inet->recverr) {
571 sk->sk_err = err;
572 sk->sk_error_report(sk);
573 } else {
574 sk->sk_err_soft = err;
575 }
576
577out_unlock:
578 sctp_err_finish(sk, asoc);
579}
580
581
582
583
584
585
586
587
588
589
590
591
592
593static int sctp_rcv_ootb(struct sk_buff *skb)
594{
595 sctp_chunkhdr_t *ch;
596 __u8 *ch_end;
597 sctp_errhdr_t *err;
598
599 ch = (sctp_chunkhdr_t *) skb->data;
600
601
602 do {
603
604 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
605 break;
606
607 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
608 if (ch_end > skb_tail_pointer(skb))
609 break;
610
611
612
613
614
615 if (SCTP_CID_ABORT == ch->type)
616 goto discard;
617
618
619
620
621
622 if (SCTP_CID_SHUTDOWN_COMPLETE == ch->type)
623 goto discard;
624
625
626
627
628
629
630 if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data)
631 goto discard;
632
633
634
635
636
637 if (SCTP_CID_COOKIE_ACK == ch->type)
638 goto discard;
639
640 if (SCTP_CID_ERROR == ch->type) {
641 sctp_walk_errors(err, ch) {
642 if (SCTP_ERROR_STALE_COOKIE == err->cause)
643 goto discard;
644 }
645 }
646
647 ch = (sctp_chunkhdr_t *) ch_end;
648 } while (ch_end < skb_tail_pointer(skb));
649
650 return 0;
651
652discard:
653 return 1;
654}
655
656
657static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
658{
659 struct sctp_ep_common *epb;
660 struct sctp_hashbucket *head;
661
662 epb = &ep->base;
663
664 epb->hashent = sctp_ep_hashfn(epb->bind_addr.port);
665 head = &sctp_ep_hashtable[epb->hashent];
666
667 sctp_write_lock(&head->lock);
668 hlist_add_head(&epb->node, &head->chain);
669 sctp_write_unlock(&head->lock);
670}
671
672
673void sctp_hash_endpoint(struct sctp_endpoint *ep)
674{
675 sctp_local_bh_disable();
676 __sctp_hash_endpoint(ep);
677 sctp_local_bh_enable();
678}
679
680
681static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
682{
683 struct sctp_hashbucket *head;
684 struct sctp_ep_common *epb;
685
686 epb = &ep->base;
687
688 if (hlist_unhashed(&epb->node))
689 return;
690
691 epb->hashent = sctp_ep_hashfn(epb->bind_addr.port);
692
693 head = &sctp_ep_hashtable[epb->hashent];
694
695 sctp_write_lock(&head->lock);
696 __hlist_del(&epb->node);
697 sctp_write_unlock(&head->lock);
698}
699
700
701void sctp_unhash_endpoint(struct sctp_endpoint *ep)
702{
703 sctp_local_bh_disable();
704 __sctp_unhash_endpoint(ep);
705 sctp_local_bh_enable();
706}
707
708
709static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *laddr)
710{
711 struct sctp_hashbucket *head;
712 struct sctp_ep_common *epb;
713 struct sctp_endpoint *ep;
714 struct hlist_node *node;
715 int hash;
716
717 hash = sctp_ep_hashfn(ntohs(laddr->v4.sin_port));
718 head = &sctp_ep_hashtable[hash];
719 read_lock(&head->lock);
720 sctp_for_each_hentry(epb, node, &head->chain) {
721 ep = sctp_ep(epb);
722 if (sctp_endpoint_is_match(ep, laddr))
723 goto hit;
724 }
725
726 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
727 epb = &ep->base;
728
729hit:
730 sctp_endpoint_hold(ep);
731 read_unlock(&head->lock);
732 return ep;
733}
734
735
736static void __sctp_hash_established(struct sctp_association *asoc)
737{
738 struct sctp_ep_common *epb;
739 struct sctp_hashbucket *head;
740
741 epb = &asoc->base;
742
743
744 epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port, asoc->peer.port);
745
746 head = &sctp_assoc_hashtable[epb->hashent];
747
748 sctp_write_lock(&head->lock);
749 hlist_add_head(&epb->node, &head->chain);
750 sctp_write_unlock(&head->lock);
751}
752
753
754void sctp_hash_established(struct sctp_association *asoc)
755{
756 if (asoc->temp)
757 return;
758
759 sctp_local_bh_disable();
760 __sctp_hash_established(asoc);
761 sctp_local_bh_enable();
762}
763
764
765static void __sctp_unhash_established(struct sctp_association *asoc)
766{
767 struct sctp_hashbucket *head;
768 struct sctp_ep_common *epb;
769
770 epb = &asoc->base;
771
772 epb->hashent = sctp_assoc_hashfn(epb->bind_addr.port,
773 asoc->peer.port);
774
775 head = &sctp_assoc_hashtable[epb->hashent];
776
777 sctp_write_lock(&head->lock);
778 __hlist_del(&epb->node);
779 sctp_write_unlock(&head->lock);
780}
781
782
783void sctp_unhash_established(struct sctp_association *asoc)
784{
785 if (asoc->temp)
786 return;
787
788 sctp_local_bh_disable();
789 __sctp_unhash_established(asoc);
790 sctp_local_bh_enable();
791}
792
793
794static struct sctp_association *__sctp_lookup_association(
795 const union sctp_addr *local,
796 const union sctp_addr *peer,
797 struct sctp_transport **pt)
798{
799 struct sctp_hashbucket *head;
800 struct sctp_ep_common *epb;
801 struct sctp_association *asoc;
802 struct sctp_transport *transport;
803 struct hlist_node *node;
804 int hash;
805
806
807
808
809 hash = sctp_assoc_hashfn(ntohs(local->v4.sin_port), ntohs(peer->v4.sin_port));
810 head = &sctp_assoc_hashtable[hash];
811 read_lock(&head->lock);
812 sctp_for_each_hentry(epb, node, &head->chain) {
813 asoc = sctp_assoc(epb);
814 transport = sctp_assoc_is_match(asoc, local, peer);
815 if (transport)
816 goto hit;
817 }
818
819 read_unlock(&head->lock);
820
821 return NULL;
822
823hit:
824 *pt = transport;
825 sctp_association_hold(asoc);
826 read_unlock(&head->lock);
827 return asoc;
828}
829
830
831SCTP_STATIC
832struct sctp_association *sctp_lookup_association(const union sctp_addr *laddr,
833 const union sctp_addr *paddr,
834 struct sctp_transport **transportp)
835{
836 struct sctp_association *asoc;
837
838 sctp_local_bh_disable();
839 asoc = __sctp_lookup_association(laddr, paddr, transportp);
840 sctp_local_bh_enable();
841
842 return asoc;
843}
844
845
846int sctp_has_association(const union sctp_addr *laddr,
847 const union sctp_addr *paddr)
848{
849 struct sctp_association *asoc;
850 struct sctp_transport *transport;
851
852 if ((asoc = sctp_lookup_association(laddr, paddr, &transport))) {
853 sctp_association_put(asoc);
854 return 1;
855 }
856
857 return 0;
858}
859
860
861
862
863
864
865
866
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868
869
870
871
872
873
874
875
876
877
878static struct sctp_association *__sctp_rcv_init_lookup(struct sk_buff *skb,
879 const union sctp_addr *laddr, struct sctp_transport **transportp)
880{
881 struct sctp_association *asoc;
882 union sctp_addr addr;
883 union sctp_addr *paddr = &addr;
884 struct sctphdr *sh = sctp_hdr(skb);
885 sctp_chunkhdr_t *ch;
886 union sctp_params params;
887 sctp_init_chunk_t *init;
888 struct sctp_transport *transport;
889 struct sctp_af *af;
890
891 ch = (sctp_chunkhdr_t *) skb->data;
892
893
894
895
896
897
898 if (WORD_ROUND(ntohs(ch->length)) > skb->len)
899 return NULL;
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917 init = (sctp_init_chunk_t *)skb->data;
918
919
920 sctp_walk_params(params, init, init_hdr.params) {
921
922
923 af = sctp_get_af_specific(param_type2af(params.p->type));
924 if (!af)
925 continue;
926
927 af->from_addr_param(paddr, params.addr, sh->source, 0);
928
929 asoc = __sctp_lookup_association(laddr, paddr, &transport);
930 if (asoc)
931 return asoc;
932 }
933
934 return NULL;
935}
936
937
938
939
940
941
942
943
944
945
946
947
948
949static struct sctp_association *__sctp_rcv_auth_lookup(struct sk_buff *skb,
950 const union sctp_addr *paddr,
951 const union sctp_addr *laddr,
952 struct sctp_transport **transportp)
953{
954
955
956
957
958 return NULL;
959}
960
961
962
963
964
965
966
967static struct sctp_association *__sctp_rcv_lookup_harder(struct sk_buff *skb,
968 const union sctp_addr *paddr,
969 const union sctp_addr *laddr,
970 struct sctp_transport **transportp)
971{
972 sctp_chunkhdr_t *ch;
973
974 ch = (sctp_chunkhdr_t *) skb->data;
975
976
977 switch (ch->type) {
978 case SCTP_CID_INIT:
979 case SCTP_CID_INIT_ACK:
980 return __sctp_rcv_init_lookup(skb, laddr, transportp);
981 break;
982
983 case SCTP_CID_AUTH:
984 return __sctp_rcv_auth_lookup(skb, paddr, laddr, transportp);
985 break;
986 }
987
988 return NULL;
989}
990
991
992static struct sctp_association *__sctp_rcv_lookup(struct sk_buff *skb,
993 const union sctp_addr *paddr,
994 const union sctp_addr *laddr,
995 struct sctp_transport **transportp)
996{
997 struct sctp_association *asoc;
998
999 asoc = __sctp_lookup_association(laddr, paddr, transportp);
1000
1001
1002
1003
1004
1005 if (!asoc)
1006 asoc = __sctp_rcv_lookup_harder(skb, paddr, laddr, transportp);
1007
1008 return asoc;
1009}
1010