net/sctp/stream_interleave.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright Red Hat Inc. 2017
   3  *
   4  * This file is part of the SCTP kernel implementation
   5  *
   6  * These functions manipulate sctp stream queue/scheduling.
   7  *
   8  * This SCTP implementation is free software;
   9  * you can redistribute it and/or modify it under the terms of
  10  * the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2, or (at your option)
  12  * any later version.
  13  *
  14  * This SCTP implementation is distributed in the hope that it
  15  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  16  *                 ************************
  17  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  18  * See the GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with GNU CC; see the file COPYING.  If not, see
  22  * <http://www.gnu.org/licenses/>.
  23  *
  24  * Please send any bug reports or fixes you make to the
  25  * email addresched(es):
  26  *    lksctp developers <linux-sctp@vger.kernel.org>
  27  *
  28  * Written or modified by:
  29  *    Xin Long <lucien.xin@gmail.com>
  30  */
  31
  32 #include <net/busy_poll.h>
  33 #include <net/sctp/sctp.h>
  34 #include <net/sctp/sm.h>
  35 #include <net/sctp/ulpevent.h>
  36 #include <linux/sctp.h>
  37
  38 static struct sctp_chunk *sctp_make_idatafrag_empty(
  39                                         const struct sctp_association *asoc,
  40                                         const struct sctp_sndrcvinfo *sinfo,
  41                                         int len, __u8 flags, gfp_t gfp)
  42 {
  43         struct sctp_chunk *retval;
  44         struct sctp_idatahdr dp;
  45
  46         memset(&dp, 0, sizeof(dp));
  47         dp.stream = htons(sinfo->sinfo_stream);
  48
  49         if (sinfo->sinfo_flags & SCTP_UNORDERED)
  50                 flags |= SCTP_DATA_UNORDERED;
  51
  52         retval = sctp_make_idata(asoc, flags, sizeof(dp) + len, gfp);
  53         if (!retval)
  54                 return NULL;
  55
  56         retval->subh.idata_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
  57         memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
  58
  59         return retval;
  60 }
  61
  62 static void sctp_chunk_assign_mid(struct sctp_chunk *chunk)
  63 {
  64         struct sctp_stream *stream;
  65         struct sctp_chunk *lchunk;
  66         __u32 cfsn = 0;
  67         __u16 sid;
  68
  69         if (chunk->has_mid)
  70                 return;
  71
  72         sid = sctp_chunk_stream_no(chunk);
  73         stream = &chunk->asoc->stream;
  74
  75         list_for_each_entry(lchunk, &chunk->msg->chunks, frag_list) {
  76                 struct sctp_idatahdr *hdr;
  77                 __u32 mid;
  78
  79                 lchunk->has_mid = 1;
  80
  81                 hdr = lchunk->subh.idata_hdr;
  82
  83                 if (lchunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG)
  84                         hdr->ppid = lchunk->sinfo.sinfo_ppid;
  85                 else
  86                         hdr->fsn = htonl(cfsn++);
  87
  88                 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
  89                         mid = lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG ?
  90                                 sctp_mid_uo_next(stream, out, sid) :
  91                                 sctp_mid_uo_peek(stream, out, sid);
  92                 } else {
  93                         mid = lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG ?
  94                                 sctp_mid_next(stream, out, sid) :
  95                                 sctp_mid_peek(stream, out, sid);
  96                 }
  97                 hdr->mid = htonl(mid);
  98         }
  99 }
 100
 101 static bool sctp_validate_data(struct sctp_chunk *chunk)
 102 {
 103         const struct sctp_stream *stream;
 104         __u16 sid, ssn;
 105
 106         if (chunk->chunk_hdr->type != SCTP_CID_DATA)
 107                 return false;
 108
 109         if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
 110                 return true;
 111
 112         stream = &chunk->asoc->stream;
 113         sid = sctp_chunk_stream_no(chunk);
 114         ssn = ntohs(chunk->subh.data_hdr->ssn);
 115
 116         return !SSN_lt(ssn, sctp_ssn_peek(stream, in, sid));
 117 }
 118
 119 static bool sctp_validate_idata(struct sctp_chunk *chunk)
 120 {
 121         struct sctp_stream *stream;
 122         __u32 mid;
 123         __u16 sid;
 124
 125         if (chunk->chunk_hdr->type != SCTP_CID_I_DATA)
 126                 return false;
 127
 128         if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
 129                 return true;
 130
 131         stream = &chunk->asoc->stream;
 132         sid = sctp_chunk_stream_no(chunk);
 133         mid = ntohl(chunk->subh.idata_hdr->mid);
 134
 135         return !MID_lt(mid, sctp_mid_peek(stream, in, sid));
 136 }
 137
 138 static void sctp_intl_store_reasm(struct sctp_ulpq *ulpq,
 139                                   struct sctp_ulpevent *event)
 140 {
 141         struct sctp_ulpevent *cevent;
 142         struct sk_buff *pos;
 143
 144         pos = skb_peek_tail(&ulpq->reasm);
 145         if (!pos) {
 146                 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
 147                 return;
 148         }
 149
 150         cevent = sctp_skb2event(pos);
 151
 152         if (event->stream == cevent->stream &&
 153             event->mid == cevent->mid &&
 154             (cevent->msg_flags & SCTP_DATA_FIRST_FRAG ||
 155              (!(event->msg_flags & SCTP_DATA_FIRST_FRAG) &&
 156               event->fsn > cevent->fsn))) {
 157                 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
 158                 return;
 159         }
 160
 161         if ((event->stream == cevent->stream &&
 162              MID_lt(cevent->mid, event->mid)) ||
 163             event->stream > cevent->stream) {
 164                 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
 165                 return;
 166         }
 167
 168         skb_queue_walk(&ulpq->reasm, pos) {
 169                 cevent = sctp_skb2event(pos);
 170
 171                 if (event->stream < cevent->stream ||
 172                     (event->stream == cevent->stream &&
 173                      MID_lt(event->mid, cevent->mid)))
 174                         break;
 175
 176                 if (event->stream == cevent->stream &&
 177                     event->mid == cevent->mid &&
 178                     !(cevent->msg_flags & SCTP_DATA_FIRST_FRAG) &&
 179                     (event->msg_flags & SCTP_DATA_FIRST_FRAG ||
 180                      event->fsn < cevent->fsn))
 181                         break;
 182         }
 183
 184         __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
 185 }
 186
 187 static struct sctp_ulpevent *sctp_intl_retrieve_partial(
 188                                                 struct sctp_ulpq *ulpq,
 189                                                 struct sctp_ulpevent *event)
 190 {
 191         struct sk_buff *first_frag = NULL;
 192         struct sk_buff *last_frag = NULL;
 193         struct sctp_ulpevent *retval;
 194         struct sctp_stream_in *sin;
 195         struct sk_buff *pos;
 196         __u32 next_fsn = 0;
 197         int is_last = 0;
 198
 199         sin = sctp_stream_in(ulpq->asoc, event->stream);
 200
 201         skb_queue_walk(&ulpq->reasm, pos) {
 202                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 203
 204                 if (cevent->stream < event->stream)
 205                         continue;
 206
 207                 if (cevent->stream > event->stream ||
 208                     cevent->mid != sin->mid)
 209                         break;
 210
 211                 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
 212                 case SCTP_DATA_FIRST_FRAG:
 213                         goto out;
 214                 case SCTP_DATA_MIDDLE_FRAG:
 215                         if (!first_frag) {
 216                                 if (cevent->fsn == sin->fsn) {
 217                                         first_frag = pos;
 218                                         last_frag = pos;
 219                                         next_fsn = cevent->fsn + 1;
 220                                 }
 221                         } else if (cevent->fsn == next_fsn) {
 222                                 last_frag = pos;
 223                                 next_fsn++;
 224                         } else {
 225                                 goto out;
 226                         }
 227                         break;
 228                 case SCTP_DATA_LAST_FRAG:
 229                         if (!first_frag) {
 230                                 if (cevent->fsn == sin->fsn) {
 231                                         first_frag = pos;
 232                                         last_frag = pos;
 233                                         next_fsn = 0;
 234                                         is_last = 1;
 235                                 }
 236                         } else if (cevent->fsn == next_fsn) {
 237                                 last_frag = pos;
 238                                 next_fsn = 0;
 239                                 is_last = 1;
 240                         }
 241                         goto out;
 242                 default:
 243                         goto out;
 244                 }
 245         }
 246
 247 out:
 248         if (!first_frag)
 249                 return NULL;
 250
 251         retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
 252                                              &ulpq->reasm, first_frag,
 253                                              last_frag);
 254         if (retval) {
 255                 sin->fsn = next_fsn;
 256                 if (is_last) {
 257                         retval->msg_flags |= MSG_EOR;
 258                         sin->pd_mode = 0;
 259                 }
 260         }
 261
 262         return retval;
 263 }
 264
 265 static struct sctp_ulpevent *sctp_intl_retrieve_reassembled(
 266                                                 struct sctp_ulpq *ulpq,
 267                                                 struct sctp_ulpevent *event)
 268 {
 269         struct sctp_association *asoc = ulpq->asoc;
 270         struct sk_buff *pos, *first_frag = NULL;
 271         struct sctp_ulpevent *retval = NULL;
 272         struct sk_buff *pd_first = NULL;
 273         struct sk_buff *pd_last = NULL;
 274         struct sctp_stream_in *sin;
 275         __u32 next_fsn = 0;
 276         __u32 pd_point = 0;
 277         __u32 pd_len = 0;
 278         __u32 mid = 0;
 279
 280         sin = sctp_stream_in(ulpq->asoc, event->stream);
 281
 282         skb_queue_walk(&ulpq->reasm, pos) {
 283                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 284
 285                 if (cevent->stream < event->stream)
 286                         continue;
 287                 if (cevent->stream > event->stream)
 288                         break;
 289
 290                 if (MID_lt(cevent->mid, event->mid))
 291                         continue;
 292                 if (MID_lt(event->mid, cevent->mid))
 293                         break;
 294
 295                 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
 296                 case SCTP_DATA_FIRST_FRAG:
 297                         if (cevent->mid == sin->mid) {
 298                                 pd_first = pos;
 299                                 pd_last = pos;
 300                                 pd_len = pos->len;
 301                         }
 302
 303                         first_frag = pos;
 304                         next_fsn = 0;
 305                         mid = cevent->mid;
 306                         break;
 307
 308                 case SCTP_DATA_MIDDLE_FRAG:
 309                         if (first_frag && cevent->mid == mid &&
 310                             cevent->fsn == next_fsn) {
 311                                 next_fsn++;
 312                                 if (pd_first) {
 313                                         pd_last = pos;
 314                                         pd_len += pos->len;
 315                                 }
 316                         } else {
 317                                 first_frag = NULL;
 318                         }
 319                         break;
 320
 321                 case SCTP_DATA_LAST_FRAG:
 322                         if (first_frag && cevent->mid == mid &&
 323                             cevent->fsn == next_fsn)
 324                                 goto found;
 325                         else
 326                                 first_frag = NULL;
 327                         break;
 328                 }
 329         }
 330
 331         if (!pd_first)
 332                 goto out;
 333
 334         pd_point = sctp_sk(asoc->base.sk)->pd_point;
 335         if (pd_point && pd_point <= pd_len) {
 336                 retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
 337                                                      &ulpq->reasm,
 338                                                      pd_first, pd_last);
 339                 if (retval) {
 340                         sin->fsn = next_fsn;
 341                         sin->pd_mode = 1;
 342                 }
 343         }
 344         goto out;
 345
 346 found:
 347         retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
 348                                              &ulpq->reasm,
 349                                              first_frag, pos);
 350         if (retval)
 351                 retval->msg_flags |= MSG_EOR;
 352
 353 out:
 354         return retval;
 355 }
 356
 357 static struct sctp_ulpevent *sctp_intl_reasm(struct sctp_ulpq *ulpq,
 358                                              struct sctp_ulpevent *event)
 359 {
 360         struct sctp_ulpevent *retval = NULL;
 361         struct sctp_stream_in *sin;
 362
 363         if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
 364                 event->msg_flags |= MSG_EOR;
 365                 return event;
 366         }
 367
 368         sctp_intl_store_reasm(ulpq, event);
 369
 370         sin = sctp_stream_in(ulpq->asoc, event->stream);
 371         if (sin->pd_mode && event->mid == sin->mid &&
 372             event->fsn == sin->fsn)
 373                 retval = sctp_intl_retrieve_partial(ulpq, event);
 374
 375         if (!retval)
 376                 retval = sctp_intl_retrieve_reassembled(ulpq, event);
 377
 378         return retval;
 379 }
 380
 381 static void sctp_intl_store_ordered(struct sctp_ulpq *ulpq,
 382                                     struct sctp_ulpevent *event)
 383 {
 384         struct sctp_ulpevent *cevent;
 385         struct sk_buff *pos;
 386
 387         pos = skb_peek_tail(&ulpq->lobby);
 388         if (!pos) {
 389                 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
 390                 return;
 391         }
 392
 393         cevent = (struct sctp_ulpevent *)pos->cb;
 394         if (event->stream == cevent->stream &&
 395             MID_lt(cevent->mid, event->mid)) {
 396                 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
 397                 return;
 398         }
 399
 400         if (event->stream > cevent->stream) {
 401                 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
 402                 return;
 403         }
 404
 405         skb_queue_walk(&ulpq->lobby, pos) {
 406                 cevent = (struct sctp_ulpevent *)pos->cb;
 407
 408                 if (cevent->stream > event->stream)
 409                         break;
 410
 411                 if (cevent->stream == event->stream &&
 412                     MID_lt(event->mid, cevent->mid))
 413                         break;
 414         }
 415
 416         __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
 417 }
 418
 419 static void sctp_intl_retrieve_ordered(struct sctp_ulpq *ulpq,
 420                                        struct sctp_ulpevent *event)
 421 {
 422         struct sk_buff_head *event_list;
 423         struct sctp_stream *stream;
 424         struct sk_buff *pos, *tmp;
 425         __u16 sid = event->stream;
 426
 427         stream  = &ulpq->asoc->stream;
 428         event_list = (struct sk_buff_head *)sctp_event2skb(event)->prev;
 429
 430         sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
 431                 struct sctp_ulpevent *cevent = (struct sctp_ulpevent *)pos->cb;
 432
 433                 if (cevent->stream > sid)
 434                         break;
 435
 436                 if (cevent->stream < sid)
 437                         continue;
 438
 439                 if (cevent->mid != sctp_mid_peek(stream, in, sid))
 440                         break;
 441
 442                 sctp_mid_next(stream, in, sid);
 443
 444                 __skb_unlink(pos, &ulpq->lobby);
 445
 446                 __skb_queue_tail(event_list, pos);
 447         }
 448 }
 449
 450 static struct sctp_ulpevent *sctp_intl_order(struct sctp_ulpq *ulpq,
 451                                              struct sctp_ulpevent *event)
 452 {
 453         struct sctp_stream *stream;
 454         __u16 sid;
 455
 456         stream  = &ulpq->asoc->stream;
 457         sid = event->stream;
 458
 459         if (event->mid != sctp_mid_peek(stream, in, sid)) {
 460                 sctp_intl_store_ordered(ulpq, event);
 461                 return NULL;
 462         }
 463
 464         sctp_mid_next(stream, in, sid);
 465
 466         sctp_intl_retrieve_ordered(ulpq, event);
 467
 468         return event;
 469 }
 470
 471 static int sctp_enqueue_event(struct sctp_ulpq *ulpq,
 472                               struct sctp_ulpevent *event)
 473 {
 474         struct sk_buff *skb = sctp_event2skb(event);
 475         struct sock *sk = ulpq->asoc->base.sk;
 476         struct sctp_sock *sp = sctp_sk(sk);
 477         struct sk_buff_head *skb_list;
 478
 479         skb_list = (struct sk_buff_head *)skb->prev;
 480
 481         if (sk->sk_shutdown & RCV_SHUTDOWN &&
 482             (sk->sk_shutdown & SEND_SHUTDOWN ||
 483              !sctp_ulpevent_is_notification(event)))
 484                 goto out_free;
 485
 486         if (!sctp_ulpevent_is_notification(event)) {
 487                 sk_mark_napi_id(sk, skb);
 488                 sk_incoming_cpu_update(sk);
 489         }
 490
 491         if (!sctp_ulpevent_is_enabled(event, &sp->subscribe))
 492                 goto out_free;
 493
 494         if (skb_list)
 495                 skb_queue_splice_tail_init(skb_list,
 496                                            &sk->sk_receive_queue);
 497         else
 498                 __skb_queue_tail(&sk->sk_receive_queue, skb);
 499
 500         if (!sp->data_ready_signalled) {
 501                 sp->data_ready_signalled = 1;
 502                 sk->sk_data_ready(sk);
 503         }
 504
 505         return 1;
 506
 507 out_free:
 508         if (skb_list)
 509                 sctp_queue_purge_ulpevents(skb_list);
 510         else
 511                 sctp_ulpevent_free(event);
 512
 513         return 0;
 514 }
 515
 516 static void sctp_intl_store_reasm_uo(struct sctp_ulpq *ulpq,
 517                                      struct sctp_ulpevent *event)
 518 {
 519         struct sctp_ulpevent *cevent;
 520         struct sk_buff *pos;
 521
 522         pos = skb_peek_tail(&ulpq->reasm_uo);
 523         if (!pos) {
 524                 __skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
 525                 return;
 526         }
 527
 528         cevent = sctp_skb2event(pos);
 529
 530         if (event->stream == cevent->stream &&
 531             event->mid == cevent->mid &&
 532             (cevent->msg_flags & SCTP_DATA_FIRST_FRAG ||
 533              (!(event->msg_flags & SCTP_DATA_FIRST_FRAG) &&
 534               event->fsn > cevent->fsn))) {
 535                 __skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
 536                 return;
 537         }
 538
 539         if ((event->stream == cevent->stream &&
 540              MID_lt(cevent->mid, event->mid)) ||
 541             event->stream > cevent->stream) {
 542                 __skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
 543                 return;
 544         }
 545
 546         skb_queue_walk(&ulpq->reasm_uo, pos) {
 547                 cevent = sctp_skb2event(pos);
 548
 549                 if (event->stream < cevent->stream ||
 550                     (event->stream == cevent->stream &&
 551                      MID_lt(event->mid, cevent->mid)))
 552                         break;
 553
 554                 if (event->stream == cevent->stream &&
 555                     event->mid == cevent->mid &&
 556                     !(cevent->msg_flags & SCTP_DATA_FIRST_FRAG) &&
 557                     (event->msg_flags & SCTP_DATA_FIRST_FRAG ||
 558                      event->fsn < cevent->fsn))
 559                         break;
 560         }
 561
 562         __skb_queue_before(&ulpq->reasm_uo, pos, sctp_event2skb(event));
 563 }
 564
 565 static struct sctp_ulpevent *sctp_intl_retrieve_partial_uo(
 566                                                 struct sctp_ulpq *ulpq,
 567                                                 struct sctp_ulpevent *event)
 568 {
 569         struct sk_buff *first_frag = NULL;
 570         struct sk_buff *last_frag = NULL;
 571         struct sctp_ulpevent *retval;
 572         struct sctp_stream_in *sin;
 573         struct sk_buff *pos;
 574         __u32 next_fsn = 0;
 575         int is_last = 0;
 576
 577         sin = sctp_stream_in(ulpq->asoc, event->stream);
 578
 579         skb_queue_walk(&ulpq->reasm_uo, pos) {
 580                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 581
 582                 if (cevent->stream < event->stream)
 583                         continue;
 584                 if (cevent->stream > event->stream)
 585                         break;
 586
 587                 if (MID_lt(cevent->mid, sin->mid_uo))
 588                         continue;
 589                 if (MID_lt(sin->mid_uo, cevent->mid))
 590                         break;
 591
 592                 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
 593                 case SCTP_DATA_FIRST_FRAG:
 594                         goto out;
 595                 case SCTP_DATA_MIDDLE_FRAG:
 596                         if (!first_frag) {
 597                                 if (cevent->fsn == sin->fsn_uo) {
 598                                         first_frag = pos;
 599                                         last_frag = pos;
 600                                         next_fsn = cevent->fsn + 1;
 601                                 }
 602                         } else if (cevent->fsn == next_fsn) {
 603                                 last_frag = pos;
 604                                 next_fsn++;
 605                         } else {
 606                                 goto out;
 607                         }
 608                         break;
 609                 case SCTP_DATA_LAST_FRAG:
 610                         if (!first_frag) {
 611                                 if (cevent->fsn == sin->fsn_uo) {
 612                                         first_frag = pos;
 613                                         last_frag = pos;
 614                                         next_fsn = 0;
 615                                         is_last = 1;
 616                                 }
 617                         } else if (cevent->fsn == next_fsn) {
 618                                 last_frag = pos;
 619                                 next_fsn = 0;
 620                                 is_last = 1;
 621                         }
 622                         goto out;
 623                 default:
 624                         goto out;
 625                 }
 626         }
 627
 628 out:
 629         if (!first_frag)
 630                 return NULL;
 631
 632         retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
 633                                              &ulpq->reasm_uo, first_frag,
 634                                              last_frag);
 635         if (retval) {
 636                 sin->fsn_uo = next_fsn;
 637                 if (is_last) {
 638                         retval->msg_flags |= MSG_EOR;
 639                         sin->pd_mode_uo = 0;
 640                 }
 641         }
 642
 643         return retval;
 644 }
 645
 646 static struct sctp_ulpevent *sctp_intl_retrieve_reassembled_uo(
 647                                                 struct sctp_ulpq *ulpq,
 648                                                 struct sctp_ulpevent *event)
 649 {
 650         struct sctp_association *asoc = ulpq->asoc;
 651         struct sk_buff *pos, *first_frag = NULL;
 652         struct sctp_ulpevent *retval = NULL;
 653         struct sk_buff *pd_first = NULL;
 654         struct sk_buff *pd_last = NULL;
 655         struct sctp_stream_in *sin;
 656         __u32 next_fsn = 0;
 657         __u32 pd_point = 0;
 658         __u32 pd_len = 0;
 659         __u32 mid = 0;
 660
 661         sin = sctp_stream_in(ulpq->asoc, event->stream);
 662
 663         skb_queue_walk(&ulpq->reasm_uo, pos) {
 664                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 665
 666                 if (cevent->stream < event->stream)
 667                         continue;
 668                 if (cevent->stream > event->stream)
 669                         break;
 670
 671                 if (MID_lt(cevent->mid, event->mid))
 672                         continue;
 673                 if (MID_lt(event->mid, cevent->mid))
 674                         break;
 675
 676                 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
 677                 case SCTP_DATA_FIRST_FRAG:
 678                         if (!sin->pd_mode_uo) {
 679                                 sin->mid_uo = cevent->mid;
 680                                 pd_first = pos;
 681                                 pd_last = pos;
 682                                 pd_len = pos->len;
 683                         }
 684
 685                         first_frag = pos;
 686                         next_fsn = 0;
 687                         mid = cevent->mid;
 688                         break;
 689
 690                 case SCTP_DATA_MIDDLE_FRAG:
 691                         if (first_frag && cevent->mid == mid &&
 692                             cevent->fsn == next_fsn) {
 693                                 next_fsn++;
 694                                 if (pd_first) {
 695                                         pd_last = pos;
 696                                         pd_len += pos->len;
 697                                 }
 698                         } else {
 699                                 first_frag = NULL;
 700                         }
 701                         break;
 702
 703                 case SCTP_DATA_LAST_FRAG:
 704                         if (first_frag && cevent->mid == mid &&
 705                             cevent->fsn == next_fsn)
 706                                 goto found;
 707                         else
 708                                 first_frag = NULL;
 709                         break;
 710                 }
 711         }
 712
 713         if (!pd_first)
 714                 goto out;
 715
 716         pd_point = sctp_sk(asoc->base.sk)->pd_point;
 717         if (pd_point && pd_point <= pd_len) {
 718                 retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
 719                                                      &ulpq->reasm_uo,
 720                                                      pd_first, pd_last);
 721                 if (retval) {
 722                         sin->fsn_uo = next_fsn;
 723                         sin->pd_mode_uo = 1;
 724                 }
 725         }
 726         goto out;
 727
 728 found:
 729         retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
 730                                              &ulpq->reasm_uo,
 731                                              first_frag, pos);
 732         if (retval)
 733                 retval->msg_flags |= MSG_EOR;
 734
 735 out:
 736         return retval;
 737 }
 738
 739 static struct sctp_ulpevent *sctp_intl_reasm_uo(struct sctp_ulpq *ulpq,
 740                                                 struct sctp_ulpevent *event)
 741 {
 742         struct sctp_ulpevent *retval = NULL;
 743         struct sctp_stream_in *sin;
 744
 745         if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
 746                 event->msg_flags |= MSG_EOR;
 747                 return event;
 748         }
 749
 750         sctp_intl_store_reasm_uo(ulpq, event);
 751
 752         sin = sctp_stream_in(ulpq->asoc, event->stream);
 753         if (sin->pd_mode_uo && event->mid == sin->mid_uo &&
 754             event->fsn == sin->fsn_uo)
 755                 retval = sctp_intl_retrieve_partial_uo(ulpq, event);
 756
 757         if (!retval)
 758                 retval = sctp_intl_retrieve_reassembled_uo(ulpq, event);
 759
 760         return retval;
 761 }
 762
 763 static struct sctp_ulpevent *sctp_intl_retrieve_first_uo(struct sctp_ulpq *ulpq)
 764 {
 765         struct sctp_stream_in *csin, *sin = NULL;
 766         struct sk_buff *first_frag = NULL;
 767         struct sk_buff *last_frag = NULL;
 768         struct sctp_ulpevent *retval;
 769         struct sk_buff *pos;
 770         __u32 next_fsn = 0;
 771         __u16 sid = 0;
 772
 773         skb_queue_walk(&ulpq->reasm_uo, pos) {
 774                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 775
 776                 csin = sctp_stream_in(ulpq->asoc, cevent->stream);
 777                 if (csin->pd_mode_uo)
 778                         continue;
 779
 780                 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
 781                 case SCTP_DATA_FIRST_FRAG:
 782                         if (first_frag)
 783                                 goto out;
 784                         first_frag = pos;
 785                         last_frag = pos;
 786                         next_fsn = 0;
 787                         sin = csin;
 788                         sid = cevent->stream;
 789                         sin->mid_uo = cevent->mid;
 790                         break;
 791                 case SCTP_DATA_MIDDLE_FRAG:
 792                         if (!first_frag)
 793                                 break;
 794                         if (cevent->stream == sid &&
 795                             cevent->mid == sin->mid_uo &&
 796                             cevent->fsn == next_fsn) {
 797                                 next_fsn++;
 798                                 last_frag = pos;
 799                         } else {
 800                                 goto out;
 801                         }
 802                         break;
 803                 case SCTP_DATA_LAST_FRAG:
 804                         if (first_frag)
 805                                 goto out;
 806                         break;
 807                 default:
 808                         break;
 809                 }
 810         }
 811
 812         if (!first_frag)
 813                 return NULL;
 814
 815 out:
 816         retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
 817                                              &ulpq->reasm_uo, first_frag,
 818                                              last_frag);
 819         if (retval) {
 820                 sin->fsn_uo = next_fsn;
 821                 sin->pd_mode_uo = 1;
 822         }
 823
 824         return retval;
 825 }
 826
 827 static int sctp_ulpevent_idata(struct sctp_ulpq *ulpq,
 828                                struct sctp_chunk *chunk, gfp_t gfp)
 829 {
 830         struct sctp_ulpevent *event;
 831         struct sk_buff_head temp;
 832         int event_eor = 0;
 833
 834         event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
 835         if (!event)
 836                 return -ENOMEM;
 837
 838         event->mid = ntohl(chunk->subh.idata_hdr->mid);
 839         if (event->msg_flags & SCTP_DATA_FIRST_FRAG)
 840                 event->ppid = chunk->subh.idata_hdr->ppid;
 841         else
 842                 event->fsn = ntohl(chunk->subh.idata_hdr->fsn);
 843
 844         if (!(event->msg_flags & SCTP_DATA_UNORDERED)) {
 845                 event = sctp_intl_reasm(ulpq, event);
 846                 if (event && event->msg_flags & MSG_EOR) {
 847                         skb_queue_head_init(&temp);
 848                         __skb_queue_tail(&temp, sctp_event2skb(event));
 849
 850                         event = sctp_intl_order(ulpq, event);
 851                 }
 852         } else {
 853                 event = sctp_intl_reasm_uo(ulpq, event);
 854         }
 855
 856         if (event) {
 857                 event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
 858                 sctp_enqueue_event(ulpq, event);
 859         }
 860
 861         return event_eor;
 862 }
 863
 864 static struct sctp_ulpevent *sctp_intl_retrieve_first(struct sctp_ulpq *ulpq)
 865 {
 866         struct sctp_stream_in *csin, *sin = NULL;
 867         struct sk_buff *first_frag = NULL;
 868         struct sk_buff *last_frag = NULL;
 869         struct sctp_ulpevent *retval;
 870         struct sk_buff *pos;
 871         __u32 next_fsn = 0;
 872         __u16 sid = 0;
 873
 874         skb_queue_walk(&ulpq->reasm, pos) {
 875                 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
 876
 877                 csin = sctp_stream_in(ulpq->asoc, cevent->stream);
 878                 if (csin->pd_mode)
 879                         continue;
 880
 881                 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
 882                 case SCTP_DATA_FIRST_FRAG:
 883                         if (first_frag)
 884                                 goto out;
 885                         if (cevent->mid == csin->mid) {
 886                                 first_frag = pos;
 887                                 last_frag = pos;
 888                                 next_fsn = 0;
 889                                 sin = csin;
 890                                 sid = cevent->stream;
 891                         }
 892                         break;
 893                 case SCTP_DATA_MIDDLE_FRAG:
 894                         if (!first_frag)
 895                                 break;
 896                         if (cevent->stream == sid &&
 897                             cevent->mid == sin->mid &&
 898                             cevent->fsn == next_fsn) {
 899                                 next_fsn++;
 900                                 last_frag = pos;
 901                         } else {
 902                                 goto out;
 903                         }
 904                         break;
 905                 case SCTP_DATA_LAST_FRAG:
 906                         if (first_frag)
 907                                 goto out;
 908                         break;
 909                 default:
 910                         break;
 911                 }
 912         }
 913
 914         if (!first_frag)
 915                 return NULL;
 916
 917 out:
 918         retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
 919                                              &ulpq->reasm, first_frag,
 920                                              last_frag);
 921         if (retval) {
 922                 sin->fsn = next_fsn;
 923                 sin->pd_mode = 1;
 924         }
 925
 926         return retval;
 927 }
 928
 929 static void sctp_intl_start_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
 930 {
 931         struct sctp_ulpevent *event;
 932
 933         if (!skb_queue_empty(&ulpq->reasm)) {
 934                 do {
 935                         event = sctp_intl_retrieve_first(ulpq);
 936                         if (event)
 937                                 sctp_enqueue_event(ulpq, event);
 938                 } while (event);
 939         }
 940
 941         if (!skb_queue_empty(&ulpq->reasm_uo)) {
 942                 do {
 943                         event = sctp_intl_retrieve_first_uo(ulpq);
 944                         if (event)
 945                                 sctp_enqueue_event(ulpq, event);
 946                 } while (event);
 947         }
 948 }
 949
 950 static void sctp_renege_events(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
 951                                gfp_t gfp)
 952 {
 953         struct sctp_association *asoc = ulpq->asoc;
 954         __u32 freed = 0;
 955         __u16 needed;
 956
 957         if (chunk) {
 958                 needed = ntohs(chunk->chunk_hdr->length);
 959                 needed -= sizeof(struct sctp_idata_chunk);
 960         } else {
 961                 needed = SCTP_DEFAULT_MAXWINDOW;
 962         }
 963
 964         if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
 965                 freed = sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
 966                 if (freed < needed)
 967                         freed += sctp_ulpq_renege_list(ulpq, &ulpq->reasm,
 968                                                        needed);
 969                 if (freed < needed)
 970                         freed += sctp_ulpq_renege_list(ulpq, &ulpq->reasm_uo,
 971                                                        needed);
 972         }
 973
 974         if (chunk && freed >= needed)
 975                 if (sctp_ulpevent_idata(ulpq, chunk, gfp) <= 0)
 976                         sctp_intl_start_pd(ulpq, gfp);
 977
 978         sk_mem_reclaim(asoc->base.sk);
 979 }
 980
 981 static void sctp_intl_stream_abort_pd(struct sctp_ulpq *ulpq, __u16 sid,
 982                                       __u32 mid, __u16 flags, gfp_t gfp)
 983 {
 984         struct sock *sk = ulpq->asoc->base.sk;
 985         struct sctp_ulpevent *ev = NULL;
 986
 987         if (!sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
 988                                         &sctp_sk(sk)->subscribe))
 989                 return;
 990
 991         ev = sctp_ulpevent_make_pdapi(ulpq->asoc, SCTP_PARTIAL_DELIVERY_ABORTED,
 992                                       sid, mid, flags, gfp);
 993         if (ev) {
 994                 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
 995
 996                 if (!sctp_sk(sk)->data_ready_signalled) {
 997                         sctp_sk(sk)->data_ready_signalled = 1;
 998                         sk->sk_data_ready(sk);
 999                 }
1000         }
1001 }
1002
1003 static void sctp_intl_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
1004 {
1005         struct sctp_stream *stream = &ulpq->asoc->stream;
1006         struct sctp_ulpevent *cevent, *event = NULL;
1007         struct sk_buff_head *lobby = &ulpq->lobby;
1008         struct sk_buff *pos, *tmp;
1009         struct sk_buff_head temp;
1010         __u16 csid;
1011         __u32 cmid;
1012
1013         skb_queue_head_init(&temp);
1014         sctp_skb_for_each(pos, lobby, tmp) {
1015                 cevent = (struct sctp_ulpevent *)pos->cb;
1016                 csid = cevent->stream;
1017                 cmid = cevent->mid;
1018
1019                 if (csid > sid)
1020                         break;
1021
1022                 if (csid < sid)
1023                         continue;
1024
1025                 if (!MID_lt(cmid, sctp_mid_peek(stream, in, csid)))
1026                         break;
1027
1028                 __skb_unlink(pos, lobby);
1029                 if (!event)
1030                         event = sctp_skb2event(pos);
1031
1032                 __skb_queue_tail(&temp, pos);
1033         }
1034
1035         if (!event && pos != (struct sk_buff *)lobby) {
1036                 cevent = (struct sctp_ulpevent *)pos->cb;
1037                 csid = cevent->stream;
1038                 cmid = cevent->mid;
1039
1040                 if (csid == sid && cmid == sctp_mid_peek(stream, in, csid)) {
1041                         sctp_mid_next(stream, in, csid);
1042                         __skb_unlink(pos, lobby);
1043                         __skb_queue_tail(&temp, pos);
1044                         event = sctp_skb2event(pos);
1045                 }
1046         }
1047
1048         if (event) {
1049                 sctp_intl_retrieve_ordered(ulpq, event);
1050                 sctp_enqueue_event(ulpq, event);
1051         }
1052 }
1053
1054 static void sctp_intl_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
1055 {
1056         struct sctp_stream *stream = &ulpq->asoc->stream;
1057         __u16 sid;
1058
1059         for (sid = 0; sid < stream->incnt; sid++) {
1060                 struct sctp_stream_in *sin = &stream->in[sid];
1061                 __u32 mid;
1062
1063                 if (sin->pd_mode_uo) {
1064                         sin->pd_mode_uo = 0;
1065
1066                         mid = sin->mid_uo;
1067                         sctp_intl_stream_abort_pd(ulpq, sid, mid, 0x1, gfp);
1068                 }
1069
1070                 if (sin->pd_mode) {
1071                         sin->pd_mode = 0;
1072
1073                         mid = sin->mid;
1074                         sctp_intl_stream_abort_pd(ulpq, sid, mid, 0, gfp);
1075                         sctp_mid_skip(stream, in, sid, mid);
1076
1077                         sctp_intl_reap_ordered(ulpq, sid);
1078                 }
1079         }
1080
1081         /* intl abort pd happens only when all data needs to be cleaned */
1082         sctp_ulpq_flush(ulpq);
1083 }
1084
1085 static inline int sctp_get_skip_pos(struct sctp_ifwdtsn_skip *skiplist,
1086                                     int nskips, __be16 stream, __u8 flags)
1087 {
1088         int i;
1089
1090         for (i = 0; i < nskips; i++)
1091                 if (skiplist[i].stream == stream &&
1092                     skiplist[i].flags == flags)
1093                         return i;
1094
1095         return i;
1096 }
1097
1098 #define SCTP_FTSN_U_BIT 0x1
1099 static void sctp_generate_iftsn(struct sctp_outq *q, __u32 ctsn)
1100 {
1101         struct sctp_ifwdtsn_skip ftsn_skip_arr[10];
1102         struct sctp_association *asoc = q->asoc;
1103         struct sctp_chunk *ftsn_chunk = NULL;
1104         struct list_head *lchunk, *temp;
1105         int nskips = 0, skip_pos;
1106         struct sctp_chunk *chunk;
1107         __u32 tsn;
1108
1109         if (!asoc->peer.prsctp_capable)
1110                 return;
1111
1112         if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1113                 asoc->adv_peer_ack_point = ctsn;
1114
1115         list_for_each_safe(lchunk, temp, &q->abandoned) {
1116                 chunk = list_entry(lchunk, struct sctp_chunk, transmitted_list);
1117                 tsn = ntohl(chunk->subh.data_hdr->tsn);
1118
1119                 if (TSN_lte(tsn, ctsn)) {
1120                         list_del_init(lchunk);
1121                         sctp_chunk_free(chunk);
1122                 } else if (TSN_lte(tsn, asoc->adv_peer_ack_point + 1)) {
1123                         __be16 sid = chunk->subh.idata_hdr->stream;
1124                         __be32 mid = chunk->subh.idata_hdr->mid;
1125                         __u8 flags = 0;
1126
1127                         if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
1128                                 flags |= SCTP_FTSN_U_BIT;
1129
1130                         asoc->adv_peer_ack_point = tsn;
1131                         skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], nskips,
1132                                                      sid, flags);
1133                         ftsn_skip_arr[skip_pos].stream = sid;
1134                         ftsn_skip_arr[skip_pos].reserved = 0;
1135                         ftsn_skip_arr[skip_pos].flags = flags;
1136                         ftsn_skip_arr[skip_pos].mid = mid;
1137                         if (skip_pos == nskips)
1138                                 nskips++;
1139                         if (nskips == 10)
1140                                 break;
1141                 } else {
1142                         break;
1143                 }
1144         }
1145
1146         if (asoc->adv_peer_ack_point > ctsn)
1147                 ftsn_chunk = sctp_make_ifwdtsn(asoc, asoc->adv_peer_ack_point,
1148                                                nskips, &ftsn_skip_arr[0]);
1149
1150         if (ftsn_chunk) {
1151                 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
1152                 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS);
1153         }
1154 }
1155
1156 #define _sctp_walk_ifwdtsn(pos, chunk, end) \
1157         for (pos = chunk->subh.ifwdtsn_hdr->skip; \
1158              (void *)pos < (void *)chunk->subh.ifwdtsn_hdr->skip + (end); pos++)
1159
1160 #define sctp_walk_ifwdtsn(pos, ch) \
1161         _sctp_walk_ifwdtsn((pos), (ch), ntohs((ch)->chunk_hdr->length) - \
1162                                         sizeof(struct sctp_ifwdtsn_chunk))
1163
1164 static bool sctp_validate_fwdtsn(struct sctp_chunk *chunk)
1165 {
1166         struct sctp_fwdtsn_skip *skip;
1167         __u16 incnt;
1168
1169         if (chunk->chunk_hdr->type != SCTP_CID_FWD_TSN)
1170                 return false;
1171
1172         incnt = chunk->asoc->stream.incnt;
1173         sctp_walk_fwdtsn(skip, chunk)
1174                 if (ntohs(skip->stream) >= incnt)
1175                         return false;
1176
1177         return true;
1178 }
1179
1180 static bool sctp_validate_iftsn(struct sctp_chunk *chunk)
1181 {
1182         struct sctp_ifwdtsn_skip *skip;
1183         __u16 incnt;
1184
1185         if (chunk->chunk_hdr->type != SCTP_CID_I_FWD_TSN)
1186                 return false;
1187
1188         incnt = chunk->asoc->stream.incnt;
1189         sctp_walk_ifwdtsn(skip, chunk)
1190                 if (ntohs(skip->stream) >= incnt)
1191                         return false;
1192
1193         return true;
1194 }
1195
1196 static void sctp_report_fwdtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1197 {
1198         /* Move the Cumulattive TSN Ack ahead. */
1199         sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
1200         /* purge the fragmentation queue */
1201         sctp_ulpq_reasm_flushtsn(ulpq, ftsn);
1202         /* Abort any in progress partial delivery. */
1203         sctp_ulpq_abort_pd(ulpq, GFP_ATOMIC);
1204 }
1205
1206 static void sctp_intl_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1207 {
1208         struct sk_buff *pos, *tmp;
1209
1210         skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
1211                 struct sctp_ulpevent *event = sctp_skb2event(pos);
1212                 __u32 tsn = event->tsn;
1213
1214                 if (TSN_lte(tsn, ftsn)) {
1215                         __skb_unlink(pos, &ulpq->reasm);
1216                         sctp_ulpevent_free(event);
1217                 }
1218         }
1219
1220         skb_queue_walk_safe(&ulpq->reasm_uo, pos, tmp) {
1221                 struct sctp_ulpevent *event = sctp_skb2event(pos);
1222                 __u32 tsn = event->tsn;
1223
1224                 if (TSN_lte(tsn, ftsn)) {
1225                         __skb_unlink(pos, &ulpq->reasm_uo);
1226                         sctp_ulpevent_free(event);
1227                 }
1228         }
1229 }
1230
1231 static void sctp_report_iftsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1232 {
1233         /* Move the Cumulattive TSN Ack ahead. */
1234         sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
1235         /* purge the fragmentation queue */
1236         sctp_intl_reasm_flushtsn(ulpq, ftsn);
1237         /* abort only when it's for all data */
1238         if (ftsn == sctp_tsnmap_get_max_tsn_seen(&ulpq->asoc->peer.tsn_map))
1239                 sctp_intl_abort_pd(ulpq, GFP_ATOMIC);
1240 }
1241
1242 static struct sctp_stream_interleave sctp_stream_interleave_0 = {
1243         .data_chunk_len         = sizeof(struct sctp_data_chunk),
1244         .ftsn_chunk_len         = sizeof(struct sctp_fwdtsn_chunk),
1245         /* DATA process functions */
1246         .make_datafrag          = sctp_make_datafrag_empty,
1247         .assign_number          = sctp_chunk_assign_ssn,
1248         .validate_data          = sctp_validate_data,
1249         .ulpevent_data          = sctp_ulpq_tail_data,
1250         .enqueue_event          = sctp_ulpq_tail_event,
1251         .renege_events          = sctp_ulpq_renege,
1252         .start_pd               = sctp_ulpq_partial_delivery,
1253         .abort_pd               = sctp_ulpq_abort_pd,
1254         /* FORWARD-TSN process functions */
1255         .generate_ftsn          = sctp_generate_fwdtsn,
1256         .validate_ftsn          = sctp_validate_fwdtsn,
1257         .report_ftsn            = sctp_report_fwdtsn,
1258 };
1259
1260 static struct sctp_stream_interleave sctp_stream_interleave_1 = {
1261         .data_chunk_len         = sizeof(struct sctp_idata_chunk),
1262         .ftsn_chunk_len         = sizeof(struct sctp_ifwdtsn_chunk),
1263         /* I-DATA process functions */
1264         .make_datafrag          = sctp_make_idatafrag_empty,
1265         .assign_number          = sctp_chunk_assign_mid,
1266         .validate_data          = sctp_validate_idata,
1267         .ulpevent_data          = sctp_ulpevent_idata,
1268         .enqueue_event          = sctp_enqueue_event,
1269         .renege_events          = sctp_renege_events,
1270         .start_pd               = sctp_intl_start_pd,
1271         .abort_pd               = sctp_intl_abort_pd,
1272         /* I-FORWARD-TSN process functions */
1273         .generate_ftsn          = sctp_generate_iftsn,
1274         .validate_ftsn          = sctp_validate_iftsn,
1275         .report_ftsn            = sctp_report_iftsn,
1276 };
1277
1278 void sctp_stream_interleave_init(struct sctp_stream *stream)
1279 {
1280         struct sctp_association *asoc;
1281
1282         asoc = container_of(stream, struct sctp_association, stream);
1283         stream->si = asoc->intl_enable ? &sctp_stream_interleave_1
1284                                        : &sctp_stream_interleave_0;
1285 }