net/sctp/stream.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999-2000 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  * Copyright (c) 2001 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * These functions manipulate sctp tsn mapping array.
  10  *
  11  * This SCTP implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * This SCTP implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, see
  25  * <http://www.gnu.org/licenses/>.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    Xin Long <lucien.xin@gmail.com>
  33  */
  34
  35 #include <net/sctp/sctp.h>
  36 #include <net/sctp/sm.h>
  37
  38 struct sctp_stream *sctp_stream_new(__u16 incnt, __u16 outcnt, gfp_t gfp)
  39 {
  40         struct sctp_stream *stream;
  41         int i;
  42
  43         stream = kzalloc(sizeof(*stream), gfp);
  44         if (!stream)
  45                 return NULL;
  46
  47         stream->outcnt = outcnt;
  48         stream->out = kcalloc(stream->outcnt, sizeof(*stream->out), gfp);
  49         if (!stream->out) {
  50                 kfree(stream);
  51                 return NULL;
  52         }
  53         for (i = 0; i < stream->outcnt; i++)
  54                 stream->out[i].state = SCTP_STREAM_OPEN;
  55
  56         stream->incnt = incnt;
  57         stream->in = kcalloc(stream->incnt, sizeof(*stream->in), gfp);
  58         if (!stream->in) {
  59                 kfree(stream->out);
  60                 kfree(stream);
  61                 return NULL;
  62         }
  63
  64         return stream;
  65 }
  66
  67 void sctp_stream_free(struct sctp_stream *stream)
  68 {
  69         if (unlikely(!stream))
  70                 return;
  71
  72         kfree(stream->out);
  73         kfree(stream->in);
  74         kfree(stream);
  75 }
  76
  77 void sctp_stream_clear(struct sctp_stream *stream)
  78 {
  79         int i;
  80
  81         for (i = 0; i < stream->outcnt; i++)
  82                 stream->out[i].ssn = 0;
  83
  84         for (i = 0; i < stream->incnt; i++)
  85                 stream->in[i].ssn = 0;
  86 }
  87
  88 static int sctp_send_reconf(struct sctp_association *asoc,
  89                             struct sctp_chunk *chunk)
  90 {
  91         struct net *net = sock_net(asoc->base.sk);
  92         int retval = 0;
  93
  94         retval = sctp_primitive_RECONF(net, asoc, chunk);
  95         if (retval)
  96                 sctp_chunk_free(chunk);
  97
  98         return retval;
  99 }
 100
 101 int sctp_send_reset_streams(struct sctp_association *asoc,
 102                             struct sctp_reset_streams *params)
 103 {
 104         struct sctp_stream *stream = asoc->stream;
 105         __u16 i, str_nums, *str_list;
 106         struct sctp_chunk *chunk;
 107         int retval = -EINVAL;
 108         bool out, in;
 109
 110         if (!asoc->peer.reconf_capable ||
 111             !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
 112                 retval = -ENOPROTOOPT;
 113                 goto out;
 114         }
 115
 116         if (asoc->strreset_outstanding) {
 117                 retval = -EINPROGRESS;
 118                 goto out;
 119         }
 120
 121         out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
 122         in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
 123         if (!out && !in)
 124                 goto out;
 125
 126         str_nums = params->srs_number_streams;
 127         str_list = params->srs_stream_list;
 128         if (out && str_nums)
 129                 for (i = 0; i < str_nums; i++)
 130                         if (str_list[i] >= stream->outcnt)
 131                                 goto out;
 132
 133         if (in && str_nums)
 134                 for (i = 0; i < str_nums; i++)
 135                         if (str_list[i] >= stream->incnt)
 136                                 goto out;
 137
 138         for (i = 0; i < str_nums; i++)
 139                 str_list[i] = htons(str_list[i]);
 140
 141         chunk = sctp_make_strreset_req(asoc, str_nums, str_list, out, in);
 142
 143         for (i = 0; i < str_nums; i++)
 144                 str_list[i] = ntohs(str_list[i]);
 145
 146         if (!chunk) {
 147                 retval = -ENOMEM;
 148                 goto out;
 149         }
 150
 151         if (out) {
 152                 if (str_nums)
 153                         for (i = 0; i < str_nums; i++)
 154                                 stream->out[str_list[i]].state =
 155                                                        SCTP_STREAM_CLOSED;
 156                 else
 157                         for (i = 0; i < stream->outcnt; i++)
 158                                 stream->out[i].state = SCTP_STREAM_CLOSED;
 159         }
 160
 161         asoc->strreset_chunk = chunk;
 162         sctp_chunk_hold(asoc->strreset_chunk);
 163
 164         retval = sctp_send_reconf(asoc, chunk);
 165         if (retval) {
 166                 sctp_chunk_put(asoc->strreset_chunk);
 167                 asoc->strreset_chunk = NULL;
 168                 if (!out)
 169                         goto out;
 170
 171                 if (str_nums)
 172                         for (i = 0; i < str_nums; i++)
 173                                 stream->out[str_list[i]].state =
 174                                                        SCTP_STREAM_OPEN;
 175                 else
 176                         for (i = 0; i < stream->outcnt; i++)
 177                                 stream->out[i].state = SCTP_STREAM_OPEN;
 178
 179                 goto out;
 180         }
 181
 182         asoc->strreset_outstanding = out + in;
 183
 184 out:
 185         return retval;
 186 }
 187
 188 int sctp_send_reset_assoc(struct sctp_association *asoc)
 189 {
 190         struct sctp_chunk *chunk = NULL;
 191         int retval;
 192         __u16 i;
 193
 194         if (!asoc->peer.reconf_capable ||
 195             !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
 196                 return -ENOPROTOOPT;
 197
 198         if (asoc->strreset_outstanding)
 199                 return -EINPROGRESS;
 200
 201         chunk = sctp_make_strreset_tsnreq(asoc);
 202         if (!chunk)
 203                 return -ENOMEM;
 204
 205         /* Block further xmit of data until this request is completed */
 206         for (i = 0; i < asoc->stream->outcnt; i++)
 207                 asoc->stream->out[i].state = SCTP_STREAM_CLOSED;
 208
 209         asoc->strreset_chunk = chunk;
 210         sctp_chunk_hold(asoc->strreset_chunk);
 211
 212         retval = sctp_send_reconf(asoc, chunk);
 213         if (retval) {
 214                 sctp_chunk_put(asoc->strreset_chunk);
 215                 asoc->strreset_chunk = NULL;
 216
 217                 for (i = 0; i < asoc->stream->outcnt; i++)
 218                         asoc->stream->out[i].state = SCTP_STREAM_OPEN;
 219
 220                 return retval;
 221         }
 222
 223         asoc->strreset_outstanding = 1;
 224
 225         return 0;
 226 }
 227
 228 int sctp_send_add_streams(struct sctp_association *asoc,
 229                           struct sctp_add_streams *params)
 230 {
 231         struct sctp_stream *stream = asoc->stream;
 232         struct sctp_chunk *chunk = NULL;
 233         int retval = -ENOMEM;
 234         __u32 outcnt, incnt;
 235         __u16 out, in;
 236
 237         if (!asoc->peer.reconf_capable ||
 238             !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
 239                 retval = -ENOPROTOOPT;
 240                 goto out;
 241         }
 242
 243         if (asoc->strreset_outstanding) {
 244                 retval = -EINPROGRESS;
 245                 goto out;
 246         }
 247
 248         out = params->sas_outstrms;
 249         in  = params->sas_instrms;
 250         outcnt = stream->outcnt + out;
 251         incnt = stream->incnt + in;
 252         if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
 253             (!out && !in)) {
 254                 retval = -EINVAL;
 255                 goto out;
 256         }
 257
 258         if (out) {
 259                 struct sctp_stream_out *streamout;
 260
 261                 streamout = krealloc(stream->out, outcnt * sizeof(*streamout),
 262                                      GFP_KERNEL);
 263                 if (!streamout)
 264                         goto out;
 265
 266                 memset(streamout + stream->outcnt, 0, out * sizeof(*streamout));
 267                 stream->out = streamout;
 268         }
 269
 270         chunk = sctp_make_strreset_addstrm(asoc, out, in);
 271         if (!chunk)
 272                 goto out;
 273
 274         asoc->strreset_chunk = chunk;
 275         sctp_chunk_hold(asoc->strreset_chunk);
 276
 277         retval = sctp_send_reconf(asoc, chunk);
 278         if (retval) {
 279                 sctp_chunk_put(asoc->strreset_chunk);
 280                 asoc->strreset_chunk = NULL;
 281                 goto out;
 282         }
 283
 284         stream->incnt = incnt;
 285         stream->outcnt = outcnt;
 286
 287         asoc->strreset_outstanding = !!out + !!in;
 288
 289 out:
 290         return retval;
 291 }
 292
 293 static sctp_paramhdr_t *sctp_chunk_lookup_strreset_param(
 294                         struct sctp_association *asoc, __u32 resp_seq,
 295                         __be16 type)
 296 {
 297         struct sctp_chunk *chunk = asoc->strreset_chunk;
 298         struct sctp_reconf_chunk *hdr;
 299         union sctp_params param;
 300
 301         if (!chunk)
 302                 return NULL;
 303
 304         hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
 305         sctp_walk_params(param, hdr, params) {
 306                 /* sctp_strreset_tsnreq is actually the basic structure
 307                  * of all stream reconf params, so it's safe to use it
 308                  * to access request_seq.
 309                  */
 310                 struct sctp_strreset_tsnreq *req = param.v;
 311
 312                 if ((!resp_seq || req->request_seq == resp_seq) &&
 313                     (!type || type == req->param_hdr.type))
 314                         return param.v;
 315         }
 316
 317         return NULL;
 318 }
 319
 320 struct sctp_chunk *sctp_process_strreset_outreq(
 321                                 struct sctp_association *asoc,
 322                                 union sctp_params param,
 323                                 struct sctp_ulpevent **evp)
 324 {
 325         struct sctp_strreset_outreq *outreq = param.v;
 326         struct sctp_stream *stream = asoc->stream;
 327         __u16 i, nums, flags = 0, *str_p = NULL;
 328         __u32 result = SCTP_STRRESET_DENIED;
 329         __u32 request_seq;
 330
 331         request_seq = ntohl(outreq->request_seq);
 332
 333         if (ntohl(outreq->send_reset_at_tsn) >
 334             sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
 335                 result = SCTP_STRRESET_IN_PROGRESS;
 336                 goto out;
 337         }
 338
 339         if (request_seq > asoc->strreset_inseq) {
 340                 result = SCTP_STRRESET_ERR_BAD_SEQNO;
 341                 goto out;
 342         } else if (request_seq == asoc->strreset_inseq) {
 343                 asoc->strreset_inseq++;
 344         }
 345
 346         /* Check strreset_enable after inseq inc, as sender cannot tell
 347          * the peer doesn't enable strreset after receiving response with
 348          * result denied, as well as to keep consistent with bsd.
 349          */
 350         if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
 351                 goto out;
 352
 353         if (asoc->strreset_chunk) {
 354                 if (!sctp_chunk_lookup_strreset_param(
 355                                 asoc, outreq->response_seq,
 356                                 SCTP_PARAM_RESET_IN_REQUEST)) {
 357                         /* same process with outstanding isn't 0 */
 358                         result = SCTP_STRRESET_ERR_IN_PROGRESS;
 359                         goto out;
 360                 }
 361
 362                 asoc->strreset_outstanding--;
 363                 asoc->strreset_outseq++;
 364
 365                 if (!asoc->strreset_outstanding) {
 366                         struct sctp_transport *t;
 367
 368                         t = asoc->strreset_chunk->transport;
 369                         if (del_timer(&t->reconf_timer))
 370                                 sctp_transport_put(t);
 371
 372                         sctp_chunk_put(asoc->strreset_chunk);
 373                         asoc->strreset_chunk = NULL;
 374                 }
 375
 376                 flags = SCTP_STREAM_RESET_INCOMING_SSN;
 377         }
 378
 379         nums = (ntohs(param.p->length) - sizeof(*outreq)) / 2;
 380         if (nums) {
 381                 str_p = outreq->list_of_streams;
 382                 for (i = 0; i < nums; i++) {
 383                         if (ntohs(str_p[i]) >= stream->incnt) {
 384                                 result = SCTP_STRRESET_ERR_WRONG_SSN;
 385                                 goto out;
 386                         }
 387                 }
 388
 389                 for (i = 0; i < nums; i++)
 390                         stream->in[ntohs(str_p[i])].ssn = 0;
 391         } else {
 392                 for (i = 0; i < stream->incnt; i++)
 393                         stream->in[i].ssn = 0;
 394         }
 395
 396         result = SCTP_STRRESET_PERFORMED;
 397
 398         *evp = sctp_ulpevent_make_stream_reset_event(asoc,
 399                 flags | SCTP_STREAM_RESET_OUTGOING_SSN, nums, str_p,
 400                 GFP_ATOMIC);
 401
 402 out:
 403         return sctp_make_strreset_resp(asoc, result, request_seq);
 404 }
 405
 406 struct sctp_chunk *sctp_process_strreset_inreq(
 407                                 struct sctp_association *asoc,
 408                                 union sctp_params param,
 409                                 struct sctp_ulpevent **evp)
 410 {
 411         struct sctp_strreset_inreq *inreq = param.v;
 412         struct sctp_stream *stream = asoc->stream;
 413         __u32 result = SCTP_STRRESET_DENIED;
 414         struct sctp_chunk *chunk = NULL;
 415         __u16 i, nums, *str_p;
 416         __u32 request_seq;
 417
 418         request_seq = ntohl(inreq->request_seq);
 419         if (request_seq > asoc->strreset_inseq) {
 420                 result = SCTP_STRRESET_ERR_BAD_SEQNO;
 421                 goto out;
 422         } else if (request_seq == asoc->strreset_inseq) {
 423                 asoc->strreset_inseq++;
 424         }
 425
 426         if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
 427                 goto out;
 428
 429         if (asoc->strreset_outstanding) {
 430                 result = SCTP_STRRESET_ERR_IN_PROGRESS;
 431                 goto out;
 432         }
 433
 434         nums = (ntohs(param.p->length) - sizeof(*inreq)) / 2;
 435         str_p = inreq->list_of_streams;
 436         for (i = 0; i < nums; i++) {
 437                 if (ntohs(str_p[i]) >= stream->outcnt) {
 438                         result = SCTP_STRRESET_ERR_WRONG_SSN;
 439                         goto out;
 440                 }
 441         }
 442
 443         chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
 444         if (!chunk)
 445                 goto out;
 446
 447         if (nums)
 448                 for (i = 0; i < nums; i++)
 449                         stream->out[ntohs(str_p[i])].state =
 450                                                SCTP_STREAM_CLOSED;
 451         else
 452                 for (i = 0; i < stream->outcnt; i++)
 453                         stream->out[i].state = SCTP_STREAM_CLOSED;
 454
 455         asoc->strreset_chunk = chunk;
 456         asoc->strreset_outstanding = 1;
 457         sctp_chunk_hold(asoc->strreset_chunk);
 458
 459         *evp = sctp_ulpevent_make_stream_reset_event(asoc,
 460                 SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
 461
 462 out:
 463         if (!chunk)
 464                 chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
 465
 466         return chunk;
 467 }
 468
 469 struct sctp_chunk *sctp_process_strreset_tsnreq(
 470                                 struct sctp_association *asoc,
 471                                 union sctp_params param,
 472                                 struct sctp_ulpevent **evp)
 473 {
 474         __u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
 475         struct sctp_strreset_tsnreq *tsnreq = param.v;
 476         struct sctp_stream *stream = asoc->stream;
 477         __u32 result = SCTP_STRRESET_DENIED;
 478         __u32 request_seq;
 479         __u16 i;
 480
 481         request_seq = ntohl(tsnreq->request_seq);
 482         if (request_seq > asoc->strreset_inseq) {
 483                 result = SCTP_STRRESET_ERR_BAD_SEQNO;
 484                 goto out;
 485         } else if (request_seq == asoc->strreset_inseq) {
 486                 asoc->strreset_inseq++;
 487         }
 488
 489         if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
 490                 goto out;
 491
 492         if (asoc->strreset_outstanding) {
 493                 result = SCTP_STRRESET_ERR_IN_PROGRESS;
 494                 goto out;
 495         }
 496
 497         /* G3: The same processing as though a SACK chunk with no gap report
 498          *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
 499          *     received MUST be performed.
 500          */
 501         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 502         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, max_tsn_seen);
 503         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 504
 505         /* G1: Compute an appropriate value for the Receiver's Next TSN -- the
 506          *     TSN that the peer should use to send the next DATA chunk.  The
 507          *     value SHOULD be the smallest TSN not acknowledged by the
 508          *     receiver of the request plus 2^31.
 509          */
 510         init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
 511         sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
 512                          init_tsn, GFP_ATOMIC);
 513
 514         /* G4: The same processing as though a FWD-TSN chunk (as defined in
 515          *     [RFC3758]) with all streams affected and a new cumulative TSN
 516          *     ACK of the Receiver's Next TSN minus 1 were received MUST be
 517          *     performed.
 518          */
 519         sctp_outq_free(&asoc->outqueue);
 520
 521         /* G2: Compute an appropriate value for the local endpoint's next TSN,
 522          *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
 523          *     chunk.  The value SHOULD be the highest TSN sent by the receiver
 524          *     of the request plus 1.
 525          */
 526         next_tsn = asoc->next_tsn;
 527         asoc->ctsn_ack_point = next_tsn - 1;
 528         asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
 529
 530         /* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
 531          *      incoming and outgoing streams.
 532          */
 533         for (i = 0; i < stream->outcnt; i++)
 534                 stream->out[i].ssn = 0;
 535         for (i = 0; i < stream->incnt; i++)
 536                 stream->in[i].ssn = 0;
 537
 538         result = SCTP_STRRESET_PERFORMED;
 539
 540         *evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
 541                                                     next_tsn, GFP_ATOMIC);
 542
 543 out:
 544         return sctp_make_strreset_tsnresp(asoc, result, request_seq,
 545                                           next_tsn, init_tsn);
 546 }
 547
 548 struct sctp_chunk *sctp_process_strreset_addstrm_out(
 549                                 struct sctp_association *asoc,
 550                                 union sctp_params param,
 551                                 struct sctp_ulpevent **evp)
 552 {
 553         struct sctp_strreset_addstrm *addstrm = param.v;
 554         struct sctp_stream *stream = asoc->stream;
 555         __u32 result = SCTP_STRRESET_DENIED;
 556         struct sctp_stream_in *streamin;
 557         __u32 request_seq, incnt;
 558         __u16 in;
 559
 560         request_seq = ntohl(addstrm->request_seq);
 561         if (request_seq > asoc->strreset_inseq) {
 562                 result = SCTP_STRRESET_ERR_BAD_SEQNO;
 563                 goto out;
 564         } else if (request_seq == asoc->strreset_inseq) {
 565                 asoc->strreset_inseq++;
 566         }
 567
 568         if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
 569                 goto out;
 570
 571         if (asoc->strreset_chunk) {
 572                 if (!sctp_chunk_lookup_strreset_param(
 573                         asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
 574                         /* same process with outstanding isn't 0 */
 575                         result = SCTP_STRRESET_ERR_IN_PROGRESS;
 576                         goto out;
 577                 }
 578
 579                 asoc->strreset_outstanding--;
 580                 asoc->strreset_outseq++;
 581
 582                 if (!asoc->strreset_outstanding) {
 583                         struct sctp_transport *t;
 584
 585                         t = asoc->strreset_chunk->transport;
 586                         if (del_timer(&t->reconf_timer))
 587                                 sctp_transport_put(t);
 588
 589                         sctp_chunk_put(asoc->strreset_chunk);
 590                         asoc->strreset_chunk = NULL;
 591                 }
 592         }
 593
 594         in = ntohs(addstrm->number_of_streams);
 595         incnt = stream->incnt + in;
 596         if (!in || incnt > SCTP_MAX_STREAM)
 597                 goto out;
 598
 599         streamin = krealloc(stream->in, incnt * sizeof(*streamin),
 600                             GFP_ATOMIC);
 601         if (!streamin)
 602                 goto out;
 603
 604         memset(streamin + stream->incnt, 0, in * sizeof(*streamin));
 605         stream->in = streamin;
 606         stream->incnt = incnt;
 607
 608         result = SCTP_STRRESET_PERFORMED;
 609
 610         *evp = sctp_ulpevent_make_stream_change_event(asoc,
 611                 0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
 612
 613 out:
 614         return sctp_make_strreset_resp(asoc, result, request_seq);
 615 }
 616
 617 struct sctp_chunk *sctp_process_strreset_addstrm_in(
 618                                 struct sctp_association *asoc,
 619                                 union sctp_params param,
 620                                 struct sctp_ulpevent **evp)
 621 {
 622         struct sctp_strreset_addstrm *addstrm = param.v;
 623         struct sctp_stream *stream = asoc->stream;
 624         __u32 result = SCTP_STRRESET_DENIED;
 625         struct sctp_stream_out *streamout;
 626         struct sctp_chunk *chunk = NULL;
 627         __u32 request_seq, outcnt;
 628         __u16 out;
 629
 630         request_seq = ntohl(addstrm->request_seq);
 631         if (request_seq > asoc->strreset_inseq) {
 632                 result = SCTP_STRRESET_ERR_BAD_SEQNO;
 633                 goto out;
 634         } else if (request_seq == asoc->strreset_inseq) {
 635                 asoc->strreset_inseq++;
 636         }
 637
 638         if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
 639                 goto out;
 640
 641         if (asoc->strreset_outstanding) {
 642                 result = SCTP_STRRESET_ERR_IN_PROGRESS;
 643                 goto out;
 644         }
 645
 646         out = ntohs(addstrm->number_of_streams);
 647         outcnt = stream->outcnt + out;
 648         if (!out || outcnt > SCTP_MAX_STREAM)
 649                 goto out;
 650
 651         streamout = krealloc(stream->out, outcnt * sizeof(*streamout),
 652                              GFP_ATOMIC);
 653         if (!streamout)
 654                 goto out;
 655
 656         memset(streamout + stream->outcnt, 0, out * sizeof(*streamout));
 657         stream->out = streamout;
 658
 659         chunk = sctp_make_strreset_addstrm(asoc, out, 0);
 660         if (!chunk)
 661                 goto out;
 662
 663         asoc->strreset_chunk = chunk;
 664         asoc->strreset_outstanding = 1;
 665         sctp_chunk_hold(asoc->strreset_chunk);
 666
 667         stream->outcnt = outcnt;
 668
 669         *evp = sctp_ulpevent_make_stream_change_event(asoc,
 670                 0, 0, ntohs(addstrm->number_of_streams), GFP_ATOMIC);
 671
 672 out:
 673         if (!chunk)
 674                 chunk = sctp_make_strreset_resp(asoc, result, request_seq);
 675
 676         return chunk;
 677 }