linux/net/sctp/sm_make_chunk.c
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   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) 2001-2002 Intel Corp.
   6 *
   7 * This file is part of the SCTP kernel implementation
   8 *
   9 * These functions work with the state functions in sctp_sm_statefuns.c
  10 * to implement the state operations.  These functions implement the
  11 * steps which require modifying existing data structures.
  12 *
  13 * This SCTP implementation is free software;
  14 * you can redistribute it and/or modify it under the terms of
  15 * the GNU General Public License as published by
  16 * the Free Software Foundation; either version 2, or (at your option)
  17 * any later version.
  18 *
  19 * This SCTP implementation is distributed in the hope that it
  20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  21 *                 ************************
  22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  23 * See the GNU General Public License for more details.
  24 *
  25 * You should have received a copy of the GNU General Public License
  26 * along with GNU CC; see the file COPYING.  If not, write to
  27 * the Free Software Foundation, 59 Temple Place - Suite 330,
  28 * Boston, MA 02111-1307, USA.
  29 *
  30 * Please send any bug reports or fixes you make to the
  31 * email address(es):
  32 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  33 *
  34 * Or submit a bug report through the following website:
  35 *    http://www.sf.net/projects/lksctp
  36 *
  37 * Written or modified by:
  38 *    La Monte H.P. Yarroll <piggy@acm.org>
  39 *    Karl Knutson          <karl@athena.chicago.il.us>
  40 *    C. Robin              <chris@hundredacre.ac.uk>
  41 *    Jon Grimm             <jgrimm@us.ibm.com>
  42 *    Xingang Guo           <xingang.guo@intel.com>
  43 *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  44 *    Sridhar Samudrala     <sri@us.ibm.com>
  45 *    Daisy Chang           <daisyc@us.ibm.com>
  46 *    Ardelle Fan           <ardelle.fan@intel.com>
  47 *    Kevin Gao             <kevin.gao@intel.com>
  48 *
  49 * Any bugs reported given to us we will try to fix... any fixes shared will
  50 * be incorporated into the next SCTP release.
  51 */
  52
  53#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  54
  55#include <linux/types.h>
  56#include <linux/kernel.h>
  57#include <linux/ip.h>
  58#include <linux/ipv6.h>
  59#include <linux/net.h>
  60#include <linux/inet.h>
  61#include <linux/scatterlist.h>
  62#include <linux/crypto.h>
  63#include <linux/slab.h>
  64#include <net/sock.h>
  65
  66#include <linux/skbuff.h>
  67#include <linux/random.h>       /* for get_random_bytes */
  68#include <net/sctp/sctp.h>
  69#include <net/sctp/sm.h>
  70
  71SCTP_STATIC
  72struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
  73                                   __u8 type, __u8 flags, int paylen);
  74static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
  75                                        const struct sctp_association *asoc,
  76                                        const struct sctp_chunk *init_chunk,
  77                                        int *cookie_len,
  78                                        const __u8 *raw_addrs, int addrs_len);
  79static int sctp_process_param(struct sctp_association *asoc,
  80                              union sctp_params param,
  81                              const union sctp_addr *peer_addr,
  82                              gfp_t gfp);
  83static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
  84                              const void *data);
  85
  86/* What was the inbound interface for this chunk? */
  87int sctp_chunk_iif(const struct sctp_chunk *chunk)
  88{
  89        struct sctp_af *af;
  90        int iif = 0;
  91
  92        af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
  93        if (af)
  94                iif = af->skb_iif(chunk->skb);
  95
  96        return iif;
  97}
  98
  99/* RFC 2960 3.3.2 Initiation (INIT) (1)
 100 *
 101 * Note 2: The ECN capable field is reserved for future use of
 102 * Explicit Congestion Notification.
 103 */
 104static const struct sctp_paramhdr ecap_param = {
 105        SCTP_PARAM_ECN_CAPABLE,
 106        cpu_to_be16(sizeof(struct sctp_paramhdr)),
 107};
 108static const struct sctp_paramhdr prsctp_param = {
 109        SCTP_PARAM_FWD_TSN_SUPPORT,
 110        cpu_to_be16(sizeof(struct sctp_paramhdr)),
 111};
 112
 113/* A helper to initialize an op error inside a
 114 * provided chunk, as most cause codes will be embedded inside an
 115 * abort chunk.
 116 */
 117void  sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
 118                      size_t paylen)
 119{
 120        sctp_errhdr_t err;
 121        __u16 len;
 122
 123        /* Cause code constants are now defined in network order.  */
 124        err.cause = cause_code;
 125        len = sizeof(sctp_errhdr_t) + paylen;
 126        err.length  = htons(len);
 127        chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
 128}
 129
 130/* A helper to initialize an op error inside a
 131 * provided chunk, as most cause codes will be embedded inside an
 132 * abort chunk.  Differs from sctp_init_cause in that it won't oops
 133 * if there isn't enough space in the op error chunk
 134 */
 135static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
 136                      size_t paylen)
 137{
 138        sctp_errhdr_t err;
 139        __u16 len;
 140
 141        /* Cause code constants are now defined in network order.  */
 142        err.cause = cause_code;
 143        len = sizeof(sctp_errhdr_t) + paylen;
 144        err.length  = htons(len);
 145
 146        if (skb_tailroom(chunk->skb) < len)
 147                return -ENOSPC;
 148        chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
 149                                                     sizeof(sctp_errhdr_t),
 150                                                     &err);
 151        return 0;
 152}
 153/* 3.3.2 Initiation (INIT) (1)
 154 *
 155 * This chunk is used to initiate a SCTP association between two
 156 * endpoints. The format of the INIT chunk is shown below:
 157 *
 158 *     0                   1                   2                   3
 159 *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 160 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 161 *    |   Type = 1    |  Chunk Flags  |      Chunk Length             |
 162 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 163 *    |                         Initiate Tag                          |
 164 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 165 *    |           Advertised Receiver Window Credit (a_rwnd)          |
 166 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 167 *    |  Number of Outbound Streams   |  Number of Inbound Streams    |
 168 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 169 *    |                          Initial TSN                          |
 170 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 171 *    \                                                               \
 172 *    /              Optional/Variable-Length Parameters              /
 173 *    \                                                               \
 174 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 175 *
 176 *
 177 * The INIT chunk contains the following parameters. Unless otherwise
 178 * noted, each parameter MUST only be included once in the INIT chunk.
 179 *
 180 * Fixed Parameters                     Status
 181 * ----------------------------------------------
 182 * Initiate Tag                        Mandatory
 183 * Advertised Receiver Window Credit   Mandatory
 184 * Number of Outbound Streams          Mandatory
 185 * Number of Inbound Streams           Mandatory
 186 * Initial TSN                         Mandatory
 187 *
 188 * Variable Parameters                  Status     Type Value
 189 * -------------------------------------------------------------
 190 * IPv4 Address (Note 1)               Optional    5
 191 * IPv6 Address (Note 1)               Optional    6
 192 * Cookie Preservative                 Optional    9
 193 * Reserved for ECN Capable (Note 2)   Optional    32768 (0x8000)
 194 * Host Name Address (Note 3)          Optional    11
 195 * Supported Address Types (Note 4)    Optional    12
 196 */
 197struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
 198                             const struct sctp_bind_addr *bp,
 199                             gfp_t gfp, int vparam_len)
 200{
 201        struct net *net = sock_net(asoc->base.sk);
 202        sctp_inithdr_t init;
 203        union sctp_params addrs;
 204        size_t chunksize;
 205        struct sctp_chunk *retval = NULL;
 206        int num_types, addrs_len = 0;
 207        struct sctp_sock *sp;
 208        sctp_supported_addrs_param_t sat;
 209        __be16 types[2];
 210        sctp_adaptation_ind_param_t aiparam;
 211        sctp_supported_ext_param_t ext_param;
 212        int num_ext = 0;
 213        __u8 extensions[3];
 214        sctp_paramhdr_t *auth_chunks = NULL,
 215                        *auth_hmacs = NULL;
 216
 217        /* RFC 2960 3.3.2 Initiation (INIT) (1)
 218         *
 219         * Note 1: The INIT chunks can contain multiple addresses that
 220         * can be IPv4 and/or IPv6 in any combination.
 221         */
 222        retval = NULL;
 223
 224        /* Convert the provided bind address list to raw format. */
 225        addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
 226
 227        init.init_tag              = htonl(asoc->c.my_vtag);
 228        init.a_rwnd                = htonl(asoc->rwnd);
 229        init.num_outbound_streams  = htons(asoc->c.sinit_num_ostreams);
 230        init.num_inbound_streams   = htons(asoc->c.sinit_max_instreams);
 231        init.initial_tsn           = htonl(asoc->c.initial_tsn);
 232
 233        /* How many address types are needed? */
 234        sp = sctp_sk(asoc->base.sk);
 235        num_types = sp->pf->supported_addrs(sp, types);
 236
 237        chunksize = sizeof(init) + addrs_len;
 238        chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
 239        chunksize += sizeof(ecap_param);
 240
 241        if (net->sctp.prsctp_enable)
 242                chunksize += sizeof(prsctp_param);
 243
 244        /* ADDIP: Section 4.2.7:
 245         *  An implementation supporting this extension [ADDIP] MUST list
 246         *  the ASCONF,the ASCONF-ACK, and the AUTH  chunks in its INIT and
 247         *  INIT-ACK parameters.
 248         */
 249        if (net->sctp.addip_enable) {
 250                extensions[num_ext] = SCTP_CID_ASCONF;
 251                extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
 252                num_ext += 2;
 253        }
 254
 255        if (sp->adaptation_ind)
 256                chunksize += sizeof(aiparam);
 257
 258        chunksize += vparam_len;
 259
 260        /* Account for AUTH related parameters */
 261        if (net->sctp.auth_enable) {
 262                /* Add random parameter length*/
 263                chunksize += sizeof(asoc->c.auth_random);
 264
 265                /* Add HMACS parameter length if any were defined */
 266                auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
 267                if (auth_hmacs->length)
 268                        chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
 269                else
 270                        auth_hmacs = NULL;
 271
 272                /* Add CHUNKS parameter length */
 273                auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
 274                if (auth_chunks->length)
 275                        chunksize += WORD_ROUND(ntohs(auth_chunks->length));
 276                else
 277                        auth_chunks = NULL;
 278
 279                extensions[num_ext] = SCTP_CID_AUTH;
 280                num_ext += 1;
 281        }
 282
 283        /* If we have any extensions to report, account for that */
 284        if (num_ext)
 285                chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
 286                                        num_ext);
 287
 288        /* RFC 2960 3.3.2 Initiation (INIT) (1)
 289         *
 290         * Note 3: An INIT chunk MUST NOT contain more than one Host
 291         * Name address parameter. Moreover, the sender of the INIT
 292         * MUST NOT combine any other address types with the Host Name
 293         * address in the INIT. The receiver of INIT MUST ignore any
 294         * other address types if the Host Name address parameter is
 295         * present in the received INIT chunk.
 296         *
 297         * PLEASE DO NOT FIXME [This version does not support Host Name.]
 298         */
 299
 300        retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize);
 301        if (!retval)
 302                goto nodata;
 303
 304        retval->subh.init_hdr =
 305                sctp_addto_chunk(retval, sizeof(init), &init);
 306        retval->param_hdr.v =
 307                sctp_addto_chunk(retval, addrs_len, addrs.v);
 308
 309        /* RFC 2960 3.3.2 Initiation (INIT) (1)
 310         *
 311         * Note 4: This parameter, when present, specifies all the
 312         * address types the sending endpoint can support. The absence
 313         * of this parameter indicates that the sending endpoint can
 314         * support any address type.
 315         */
 316        sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
 317        sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
 318        sctp_addto_chunk(retval, sizeof(sat), &sat);
 319        sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
 320
 321        sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
 322
 323        /* Add the supported extensions parameter.  Be nice and add this
 324         * fist before addiding the parameters for the extensions themselves
 325         */
 326        if (num_ext) {
 327                ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
 328                ext_param.param_hdr.length =
 329                            htons(sizeof(sctp_supported_ext_param_t) + num_ext);
 330                sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
 331                                &ext_param);
 332                sctp_addto_param(retval, num_ext, extensions);
 333        }
 334
 335        if (net->sctp.prsctp_enable)
 336                sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
 337
 338        if (sp->adaptation_ind) {
 339                aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
 340                aiparam.param_hdr.length = htons(sizeof(aiparam));
 341                aiparam.adaptation_ind = htonl(sp->adaptation_ind);
 342                sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
 343        }
 344
 345        /* Add SCTP-AUTH chunks to the parameter list */
 346        if (net->sctp.auth_enable) {
 347                sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
 348                                 asoc->c.auth_random);
 349                if (auth_hmacs)
 350                        sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
 351                                        auth_hmacs);
 352                if (auth_chunks)
 353                        sctp_addto_chunk(retval, ntohs(auth_chunks->length),
 354                                        auth_chunks);
 355        }
 356nodata:
 357        kfree(addrs.v);
 358        return retval;
 359}
 360
 361struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
 362                                 const struct sctp_chunk *chunk,
 363                                 gfp_t gfp, int unkparam_len)
 364{
 365        sctp_inithdr_t initack;
 366        struct sctp_chunk *retval;
 367        union sctp_params addrs;
 368        struct sctp_sock *sp;
 369        int addrs_len;
 370        sctp_cookie_param_t *cookie;
 371        int cookie_len;
 372        size_t chunksize;
 373        sctp_adaptation_ind_param_t aiparam;
 374        sctp_supported_ext_param_t ext_param;
 375        int num_ext = 0;
 376        __u8 extensions[3];
 377        sctp_paramhdr_t *auth_chunks = NULL,
 378                        *auth_hmacs = NULL,
 379                        *auth_random = NULL;
 380
 381        retval = NULL;
 382
 383        /* Note: there may be no addresses to embed. */
 384        addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
 385
 386        initack.init_tag                = htonl(asoc->c.my_vtag);
 387        initack.a_rwnd                  = htonl(asoc->rwnd);
 388        initack.num_outbound_streams    = htons(asoc->c.sinit_num_ostreams);
 389        initack.num_inbound_streams     = htons(asoc->c.sinit_max_instreams);
 390        initack.initial_tsn             = htonl(asoc->c.initial_tsn);
 391
 392        /* FIXME:  We really ought to build the cookie right
 393         * into the packet instead of allocating more fresh memory.
 394         */
 395        cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
 396                                  addrs.v, addrs_len);
 397        if (!cookie)
 398                goto nomem_cookie;
 399
 400        /* Calculate the total size of allocation, include the reserved
 401         * space for reporting unknown parameters if it is specified.
 402         */
 403        sp = sctp_sk(asoc->base.sk);
 404        chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
 405
 406        /* Tell peer that we'll do ECN only if peer advertised such cap.  */
 407        if (asoc->peer.ecn_capable)
 408                chunksize += sizeof(ecap_param);
 409
 410        if (asoc->peer.prsctp_capable)
 411                chunksize += sizeof(prsctp_param);
 412
 413        if (asoc->peer.asconf_capable) {
 414                extensions[num_ext] = SCTP_CID_ASCONF;
 415                extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
 416                num_ext += 2;
 417        }
 418
 419        if (sp->adaptation_ind)
 420                chunksize += sizeof(aiparam);
 421
 422        if (asoc->peer.auth_capable) {
 423                auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
 424                chunksize += ntohs(auth_random->length);
 425
 426                auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
 427                if (auth_hmacs->length)
 428                        chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
 429                else
 430                        auth_hmacs = NULL;
 431
 432                auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
 433                if (auth_chunks->length)
 434                        chunksize += WORD_ROUND(ntohs(auth_chunks->length));
 435                else
 436                        auth_chunks = NULL;
 437
 438                extensions[num_ext] = SCTP_CID_AUTH;
 439                num_ext += 1;
 440        }
 441
 442        if (num_ext)
 443                chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
 444                                        num_ext);
 445
 446        /* Now allocate and fill out the chunk.  */
 447        retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
 448        if (!retval)
 449                goto nomem_chunk;
 450
 451        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 452         *
 453         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 454         * HEARTBEAT ACK, * etc.) to the same destination transport
 455         * address from which it received the DATA or control chunk
 456         * to which it is replying.
 457         *
 458         * [INIT ACK back to where the INIT came from.]
 459         */
 460        retval->transport = chunk->transport;
 461
 462        retval->subh.init_hdr =
 463                sctp_addto_chunk(retval, sizeof(initack), &initack);
 464        retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
 465        sctp_addto_chunk(retval, cookie_len, cookie);
 466        if (asoc->peer.ecn_capable)
 467                sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
 468        if (num_ext) {
 469                ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
 470                ext_param.param_hdr.length =
 471                            htons(sizeof(sctp_supported_ext_param_t) + num_ext);
 472                sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
 473                                 &ext_param);
 474                sctp_addto_param(retval, num_ext, extensions);
 475        }
 476        if (asoc->peer.prsctp_capable)
 477                sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
 478
 479        if (sp->adaptation_ind) {
 480                aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
 481                aiparam.param_hdr.length = htons(sizeof(aiparam));
 482                aiparam.adaptation_ind = htonl(sp->adaptation_ind);
 483                sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
 484        }
 485
 486        if (asoc->peer.auth_capable) {
 487                sctp_addto_chunk(retval, ntohs(auth_random->length),
 488                                 auth_random);
 489                if (auth_hmacs)
 490                        sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
 491                                        auth_hmacs);
 492                if (auth_chunks)
 493                        sctp_addto_chunk(retval, ntohs(auth_chunks->length),
 494                                        auth_chunks);
 495        }
 496
 497        /* We need to remove the const qualifier at this point.  */
 498        retval->asoc = (struct sctp_association *) asoc;
 499
 500nomem_chunk:
 501        kfree(cookie);
 502nomem_cookie:
 503        kfree(addrs.v);
 504        return retval;
 505}
 506
 507/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
 508 *
 509 * This chunk is used only during the initialization of an association.
 510 * It is sent by the initiator of an association to its peer to complete
 511 * the initialization process. This chunk MUST precede any DATA chunk
 512 * sent within the association, but MAY be bundled with one or more DATA
 513 * chunks in the same packet.
 514 *
 515 *      0                   1                   2                   3
 516 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 517 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 518 *     |   Type = 10   |Chunk  Flags   |         Length                |
 519 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 520 *     /                     Cookie                                    /
 521 *     \                                                               \
 522 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 523 *
 524 * Chunk Flags: 8 bit
 525 *
 526 *   Set to zero on transmit and ignored on receipt.
 527 *
 528 * Length: 16 bits (unsigned integer)
 529 *
 530 *   Set to the size of the chunk in bytes, including the 4 bytes of
 531 *   the chunk header and the size of the Cookie.
 532 *
 533 * Cookie: variable size
 534 *
 535 *   This field must contain the exact cookie received in the
 536 *   State Cookie parameter from the previous INIT ACK.
 537 *
 538 *   An implementation SHOULD make the cookie as small as possible
 539 *   to insure interoperability.
 540 */
 541struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
 542                                    const struct sctp_chunk *chunk)
 543{
 544        struct sctp_chunk *retval;
 545        void *cookie;
 546        int cookie_len;
 547
 548        cookie = asoc->peer.cookie;
 549        cookie_len = asoc->peer.cookie_len;
 550
 551        /* Build a cookie echo chunk.  */
 552        retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
 553        if (!retval)
 554                goto nodata;
 555        retval->subh.cookie_hdr =
 556                sctp_addto_chunk(retval, cookie_len, cookie);
 557
 558        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 559         *
 560         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 561         * HEARTBEAT ACK, * etc.) to the same destination transport
 562         * address from which it * received the DATA or control chunk
 563         * to which it is replying.
 564         *
 565         * [COOKIE ECHO back to where the INIT ACK came from.]
 566         */
 567        if (chunk)
 568                retval->transport = chunk->transport;
 569
 570nodata:
 571        return retval;
 572}
 573
 574/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
 575 *
 576 * This chunk is used only during the initialization of an
 577 * association.  It is used to acknowledge the receipt of a COOKIE
 578 * ECHO chunk.  This chunk MUST precede any DATA or SACK chunk sent
 579 * within the association, but MAY be bundled with one or more DATA
 580 * chunks or SACK chunk in the same SCTP packet.
 581 *
 582 *      0                   1                   2                   3
 583 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 584 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 585 *     |   Type = 11   |Chunk  Flags   |     Length = 4                |
 586 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 587 *
 588 * Chunk Flags: 8 bits
 589 *
 590 *   Set to zero on transmit and ignored on receipt.
 591 */
 592struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
 593                                   const struct sctp_chunk *chunk)
 594{
 595        struct sctp_chunk *retval;
 596
 597        retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
 598
 599        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 600         *
 601         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 602         * HEARTBEAT ACK, * etc.) to the same destination transport
 603         * address from which it * received the DATA or control chunk
 604         * to which it is replying.
 605         *
 606         * [COOKIE ACK back to where the COOKIE ECHO came from.]
 607         */
 608        if (retval && chunk)
 609                retval->transport = chunk->transport;
 610
 611        return retval;
 612}
 613
 614/*
 615 *  Appendix A: Explicit Congestion Notification:
 616 *  CWR:
 617 *
 618 *  RFC 2481 details a specific bit for a sender to send in the header of
 619 *  its next outbound TCP segment to indicate to its peer that it has
 620 *  reduced its congestion window.  This is termed the CWR bit.  For
 621 *  SCTP the same indication is made by including the CWR chunk.
 622 *  This chunk contains one data element, i.e. the TSN number that
 623 *  was sent in the ECNE chunk.  This element represents the lowest
 624 *  TSN number in the datagram that was originally marked with the
 625 *  CE bit.
 626 *
 627 *     0                   1                   2                   3
 628 *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 629 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 630 *    | Chunk Type=13 | Flags=00000000|    Chunk Length = 8           |
 631 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 632 *    |                      Lowest TSN Number                        |
 633 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 634 *
 635 *     Note: The CWR is considered a Control chunk.
 636 */
 637struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
 638                            const __u32 lowest_tsn,
 639                            const struct sctp_chunk *chunk)
 640{
 641        struct sctp_chunk *retval;
 642        sctp_cwrhdr_t cwr;
 643
 644        cwr.lowest_tsn = htonl(lowest_tsn);
 645        retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0,
 646                                 sizeof(sctp_cwrhdr_t));
 647
 648        if (!retval)
 649                goto nodata;
 650
 651        retval->subh.ecn_cwr_hdr =
 652                sctp_addto_chunk(retval, sizeof(cwr), &cwr);
 653
 654        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 655         *
 656         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 657         * HEARTBEAT ACK, * etc.) to the same destination transport
 658         * address from which it * received the DATA or control chunk
 659         * to which it is replying.
 660         *
 661         * [Report a reduced congestion window back to where the ECNE
 662         * came from.]
 663         */
 664        if (chunk)
 665                retval->transport = chunk->transport;
 666
 667nodata:
 668        return retval;
 669}
 670
 671/* Make an ECNE chunk.  This is a congestion experienced report.  */
 672struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
 673                             const __u32 lowest_tsn)
 674{
 675        struct sctp_chunk *retval;
 676        sctp_ecnehdr_t ecne;
 677
 678        ecne.lowest_tsn = htonl(lowest_tsn);
 679        retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0,
 680                                 sizeof(sctp_ecnehdr_t));
 681        if (!retval)
 682                goto nodata;
 683        retval->subh.ecne_hdr =
 684                sctp_addto_chunk(retval, sizeof(ecne), &ecne);
 685
 686nodata:
 687        return retval;
 688}
 689
 690/* Make a DATA chunk for the given association from the provided
 691 * parameters.  However, do not populate the data payload.
 692 */
 693struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
 694                                       const struct sctp_sndrcvinfo *sinfo,
 695                                       int data_len, __u8 flags, __u16 ssn)
 696{
 697        struct sctp_chunk *retval;
 698        struct sctp_datahdr dp;
 699        int chunk_len;
 700
 701        /* We assign the TSN as LATE as possible, not here when
 702         * creating the chunk.
 703         */
 704        dp.tsn = 0;
 705        dp.stream = htons(sinfo->sinfo_stream);
 706        dp.ppid   = sinfo->sinfo_ppid;
 707
 708        /* Set the flags for an unordered send.  */
 709        if (sinfo->sinfo_flags & SCTP_UNORDERED) {
 710                flags |= SCTP_DATA_UNORDERED;
 711                dp.ssn = 0;
 712        } else
 713                dp.ssn = htons(ssn);
 714
 715        chunk_len = sizeof(dp) + data_len;
 716        retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len);
 717        if (!retval)
 718                goto nodata;
 719
 720        retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
 721        memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
 722
 723nodata:
 724        return retval;
 725}
 726
 727/* Create a selective ackowledgement (SACK) for the given
 728 * association.  This reports on which TSN's we've seen to date,
 729 * including duplicates and gaps.
 730 */
 731struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
 732{
 733        struct sctp_chunk *retval;
 734        struct sctp_sackhdr sack;
 735        int len;
 736        __u32 ctsn;
 737        __u16 num_gabs, num_dup_tsns;
 738        struct sctp_association *aptr = (struct sctp_association *)asoc;
 739        struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
 740        struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
 741        struct sctp_transport *trans;
 742
 743        memset(gabs, 0, sizeof(gabs));
 744        ctsn = sctp_tsnmap_get_ctsn(map);
 745        SCTP_DEBUG_PRINTK("sackCTSNAck sent:  0x%x.\n", ctsn);
 746
 747        /* How much room is needed in the chunk? */
 748        num_gabs = sctp_tsnmap_num_gabs(map, gabs);
 749        num_dup_tsns = sctp_tsnmap_num_dups(map);
 750
 751        /* Initialize the SACK header.  */
 752        sack.cum_tsn_ack            = htonl(ctsn);
 753        sack.a_rwnd                 = htonl(asoc->a_rwnd);
 754        sack.num_gap_ack_blocks     = htons(num_gabs);
 755        sack.num_dup_tsns           = htons(num_dup_tsns);
 756
 757        len = sizeof(sack)
 758                + sizeof(struct sctp_gap_ack_block) * num_gabs
 759                + sizeof(__u32) * num_dup_tsns;
 760
 761        /* Create the chunk.  */
 762        retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len);
 763        if (!retval)
 764                goto nodata;
 765
 766        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 767         *
 768         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 769         * HEARTBEAT ACK, etc.) to the same destination transport
 770         * address from which it received the DATA or control chunk to
 771         * which it is replying.  This rule should also be followed if
 772         * the endpoint is bundling DATA chunks together with the
 773         * reply chunk.
 774         *
 775         * However, when acknowledging multiple DATA chunks received
 776         * in packets from different source addresses in a single
 777         * SACK, the SACK chunk may be transmitted to one of the
 778         * destination transport addresses from which the DATA or
 779         * control chunks being acknowledged were received.
 780         *
 781         * [BUG:  We do not implement the following paragraph.
 782         * Perhaps we should remember the last transport we used for a
 783         * SACK and avoid that (if possible) if we have seen any
 784         * duplicates. --piggy]
 785         *
 786         * When a receiver of a duplicate DATA chunk sends a SACK to a
 787         * multi- homed endpoint it MAY be beneficial to vary the
 788         * destination address and not use the source address of the
 789         * DATA chunk.  The reason being that receiving a duplicate
 790         * from a multi-homed endpoint might indicate that the return
 791         * path (as specified in the source address of the DATA chunk)
 792         * for the SACK is broken.
 793         *
 794         * [Send to the address from which we last received a DATA chunk.]
 795         */
 796        retval->transport = asoc->peer.last_data_from;
 797
 798        retval->subh.sack_hdr =
 799                sctp_addto_chunk(retval, sizeof(sack), &sack);
 800
 801        /* Add the gap ack block information.   */
 802        if (num_gabs)
 803                sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
 804                                 gabs);
 805
 806        /* Add the duplicate TSN information.  */
 807        if (num_dup_tsns) {
 808                aptr->stats.idupchunks += num_dup_tsns;
 809                sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
 810                                 sctp_tsnmap_get_dups(map));
 811        }
 812        /* Once we have a sack generated, check to see what our sack
 813         * generation is, if its 0, reset the transports to 0, and reset
 814         * the association generation to 1
 815         *
 816         * The idea is that zero is never used as a valid generation for the
 817         * association so no transport will match after a wrap event like this,
 818         * Until the next sack
 819         */
 820        if (++aptr->peer.sack_generation == 0) {
 821                list_for_each_entry(trans, &asoc->peer.transport_addr_list,
 822                                    transports)
 823                        trans->sack_generation = 0;
 824                aptr->peer.sack_generation = 1;
 825        }
 826nodata:
 827        return retval;
 828}
 829
 830/* Make a SHUTDOWN chunk. */
 831struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
 832                                      const struct sctp_chunk *chunk)
 833{
 834        struct sctp_chunk *retval;
 835        sctp_shutdownhdr_t shut;
 836        __u32 ctsn;
 837
 838        ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 839        shut.cum_tsn_ack = htonl(ctsn);
 840
 841        retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0,
 842                                 sizeof(sctp_shutdownhdr_t));
 843        if (!retval)
 844                goto nodata;
 845
 846        retval->subh.shutdown_hdr =
 847                sctp_addto_chunk(retval, sizeof(shut), &shut);
 848
 849        if (chunk)
 850                retval->transport = chunk->transport;
 851nodata:
 852        return retval;
 853}
 854
 855struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
 856                                     const struct sctp_chunk *chunk)
 857{
 858        struct sctp_chunk *retval;
 859
 860        retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
 861
 862        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 863         *
 864         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 865         * HEARTBEAT ACK, * etc.) to the same destination transport
 866         * address from which it * received the DATA or control chunk
 867         * to which it is replying.
 868         *
 869         * [ACK back to where the SHUTDOWN came from.]
 870         */
 871        if (retval && chunk)
 872                retval->transport = chunk->transport;
 873
 874        return retval;
 875}
 876
 877struct sctp_chunk *sctp_make_shutdown_complete(
 878        const struct sctp_association *asoc,
 879        const struct sctp_chunk *chunk)
 880{
 881        struct sctp_chunk *retval;
 882        __u8 flags = 0;
 883
 884        /* Set the T-bit if we have no association (vtag will be
 885         * reflected)
 886         */
 887        flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
 888
 889        retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
 890
 891        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 892         *
 893         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 894         * HEARTBEAT ACK, * etc.) to the same destination transport
 895         * address from which it * received the DATA or control chunk
 896         * to which it is replying.
 897         *
 898         * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
 899         * came from.]
 900         */
 901        if (retval && chunk)
 902                retval->transport = chunk->transport;
 903
 904        return retval;
 905}
 906
 907/* Create an ABORT.  Note that we set the T bit if we have no
 908 * association, except when responding to an INIT (sctpimpguide 2.41).
 909 */
 910struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
 911                              const struct sctp_chunk *chunk,
 912                              const size_t hint)
 913{
 914        struct sctp_chunk *retval;
 915        __u8 flags = 0;
 916
 917        /* Set the T-bit if we have no association and 'chunk' is not
 918         * an INIT (vtag will be reflected).
 919         */
 920        if (!asoc) {
 921                if (chunk && chunk->chunk_hdr &&
 922                    chunk->chunk_hdr->type == SCTP_CID_INIT)
 923                        flags = 0;
 924                else
 925                        flags = SCTP_CHUNK_FLAG_T;
 926        }
 927
 928        retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);
 929
 930        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 931         *
 932         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 933         * HEARTBEAT ACK, * etc.) to the same destination transport
 934         * address from which it * received the DATA or control chunk
 935         * to which it is replying.
 936         *
 937         * [ABORT back to where the offender came from.]
 938         */
 939        if (retval && chunk)
 940                retval->transport = chunk->transport;
 941
 942        return retval;
 943}
 944
 945/* Helper to create ABORT with a NO_USER_DATA error.  */
 946struct sctp_chunk *sctp_make_abort_no_data(
 947        const struct sctp_association *asoc,
 948        const struct sctp_chunk *chunk, __u32 tsn)
 949{
 950        struct sctp_chunk *retval;
 951        __be32 payload;
 952
 953        retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
 954                                 + sizeof(tsn));
 955
 956        if (!retval)
 957                goto no_mem;
 958
 959        /* Put the tsn back into network byte order.  */
 960        payload = htonl(tsn);
 961        sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
 962        sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
 963
 964        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 965         *
 966         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 967         * HEARTBEAT ACK, * etc.) to the same destination transport
 968         * address from which it * received the DATA or control chunk
 969         * to which it is replying.
 970         *
 971         * [ABORT back to where the offender came from.]
 972         */
 973        if (chunk)
 974                retval->transport = chunk->transport;
 975
 976no_mem:
 977        return retval;
 978}
 979
 980/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error.  */
 981struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
 982                                        const struct msghdr *msg,
 983                                        size_t paylen)
 984{
 985        struct sctp_chunk *retval;
 986        void *payload = NULL;
 987        int err;
 988
 989        retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
 990        if (!retval)
 991                goto err_chunk;
 992
 993        if (paylen) {
 994                /* Put the msg_iov together into payload.  */
 995                payload = kmalloc(paylen, GFP_KERNEL);
 996                if (!payload)
 997                        goto err_payload;
 998
 999                err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
1000                if (err < 0)
1001                        goto err_copy;
1002        }
1003
1004        sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1005        sctp_addto_chunk(retval, paylen, payload);
1006
1007        if (paylen)
1008                kfree(payload);
1009
1010        return retval;
1011
1012err_copy:
1013        kfree(payload);
1014err_payload:
1015        sctp_chunk_free(retval);
1016        retval = NULL;
1017err_chunk:
1018        return retval;
1019}
1020
1021/* Append bytes to the end of a parameter.  Will panic if chunk is not big
1022 * enough.
1023 */
1024static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1025                              const void *data)
1026{
1027        void *target;
1028        int chunklen = ntohs(chunk->chunk_hdr->length);
1029
1030        target = skb_put(chunk->skb, len);
1031
1032        if (data)
1033                memcpy(target, data, len);
1034        else
1035                memset(target, 0, len);
1036
1037        /* Adjust the chunk length field.  */
1038        chunk->chunk_hdr->length = htons(chunklen + len);
1039        chunk->chunk_end = skb_tail_pointer(chunk->skb);
1040
1041        return target;
1042}
1043
1044/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1045struct sctp_chunk *sctp_make_abort_violation(
1046        const struct sctp_association *asoc,
1047        const struct sctp_chunk *chunk,
1048        const __u8   *payload,
1049        const size_t paylen)
1050{
1051        struct sctp_chunk  *retval;
1052        struct sctp_paramhdr phdr;
1053
1054        retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1055                                        + sizeof(sctp_paramhdr_t));
1056        if (!retval)
1057                goto end;
1058
1059        sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1060                                        + sizeof(sctp_paramhdr_t));
1061
1062        phdr.type = htons(chunk->chunk_hdr->type);
1063        phdr.length = chunk->chunk_hdr->length;
1064        sctp_addto_chunk(retval, paylen, payload);
1065        sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1066
1067end:
1068        return retval;
1069}
1070
1071struct sctp_chunk *sctp_make_violation_paramlen(
1072        const struct sctp_association *asoc,
1073        const struct sctp_chunk *chunk,
1074        struct sctp_paramhdr *param)
1075{
1076        struct sctp_chunk *retval;
1077        static const char error[] = "The following parameter had invalid length:";
1078        size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1079                                sizeof(sctp_paramhdr_t);
1080
1081        retval = sctp_make_abort(asoc, chunk, payload_len);
1082        if (!retval)
1083                goto nodata;
1084
1085        sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1086                        sizeof(error) + sizeof(sctp_paramhdr_t));
1087        sctp_addto_chunk(retval, sizeof(error), error);
1088        sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1089
1090nodata:
1091        return retval;
1092}
1093
1094struct sctp_chunk *sctp_make_violation_max_retrans(
1095        const struct sctp_association *asoc,
1096        const struct sctp_chunk *chunk)
1097{
1098        struct sctp_chunk *retval;
1099        static const char error[] = "Association exceeded its max_retans count";
1100        size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1101
1102        retval = sctp_make_abort(asoc, chunk, payload_len);
1103        if (!retval)
1104                goto nodata;
1105
1106        sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1107        sctp_addto_chunk(retval, sizeof(error), error);
1108
1109nodata:
1110        return retval;
1111}
1112
1113/* Make a HEARTBEAT chunk.  */
1114struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1115                                  const struct sctp_transport *transport)
1116{
1117        struct sctp_chunk *retval;
1118        sctp_sender_hb_info_t hbinfo;
1119
1120        retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
1121
1122        if (!retval)
1123                goto nodata;
1124
1125        hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1126        hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1127        hbinfo.daddr = transport->ipaddr;
1128        hbinfo.sent_at = jiffies;
1129        hbinfo.hb_nonce = transport->hb_nonce;
1130
1131        /* Cast away the 'const', as this is just telling the chunk
1132         * what transport it belongs to.
1133         */
1134        retval->transport = (struct sctp_transport *) transport;
1135        retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1136                                                &hbinfo);
1137
1138nodata:
1139        return retval;
1140}
1141
1142struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1143                                      const struct sctp_chunk *chunk,
1144                                      const void *payload, const size_t paylen)
1145{
1146        struct sctp_chunk *retval;
1147
1148        retval  = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1149        if (!retval)
1150                goto nodata;
1151
1152        retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1153
1154        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1155         *
1156         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1157         * HEARTBEAT ACK, * etc.) to the same destination transport
1158         * address from which it * received the DATA or control chunk
1159         * to which it is replying.
1160         *
1161         * [HBACK back to where the HEARTBEAT came from.]
1162         */
1163        if (chunk)
1164                retval->transport = chunk->transport;
1165
1166nodata:
1167        return retval;
1168}
1169
1170/* Create an Operation Error chunk with the specified space reserved.
1171 * This routine can be used for containing multiple causes in the chunk.
1172 */
1173static struct sctp_chunk *sctp_make_op_error_space(
1174        const struct sctp_association *asoc,
1175        const struct sctp_chunk *chunk,
1176        size_t size)
1177{
1178        struct sctp_chunk *retval;
1179
1180        retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0,
1181                                 sizeof(sctp_errhdr_t) + size);
1182        if (!retval)
1183                goto nodata;
1184
1185        /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1186         *
1187         * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1188         * HEARTBEAT ACK, etc.) to the same destination transport
1189         * address from which it received the DATA or control chunk
1190         * to which it is replying.
1191         *
1192         */
1193        if (chunk)
1194                retval->transport = chunk->transport;
1195
1196nodata:
1197        return retval;
1198}
1199
1200/* Create an Operation Error chunk of a fixed size,
1201 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1202 * This is a helper function to allocate an error chunk for
1203 * for those invalid parameter codes in which we may not want
1204 * to report all the errors, if the incomming chunk is large
1205 */
1206static inline struct sctp_chunk *sctp_make_op_error_fixed(
1207        const struct sctp_association *asoc,
1208        const struct sctp_chunk *chunk)
1209{
1210        size_t size = asoc ? asoc->pathmtu : 0;
1211
1212        if (!size)
1213                size = SCTP_DEFAULT_MAXSEGMENT;
1214
1215        return sctp_make_op_error_space(asoc, chunk, size);
1216}
1217
1218/* Create an Operation Error chunk.  */
1219struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1220                                 const struct sctp_chunk *chunk,
1221                                 __be16 cause_code, const void *payload,
1222                                 size_t paylen, size_t reserve_tail)
1223{
1224        struct sctp_chunk *retval;
1225
1226        retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1227        if (!retval)
1228                goto nodata;
1229
1230        sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1231        sctp_addto_chunk(retval, paylen, payload);
1232        if (reserve_tail)
1233                sctp_addto_param(retval, reserve_tail, NULL);
1234
1235nodata:
1236        return retval;
1237}
1238
1239struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1240{
1241        struct sctp_chunk *retval;
1242        struct sctp_hmac *hmac_desc;
1243        struct sctp_authhdr auth_hdr;
1244        __u8 *hmac;
1245
1246        /* Get the first hmac that the peer told us to use */
1247        hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1248        if (unlikely(!hmac_desc))
1249                return NULL;
1250
1251        retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0,
1252                        hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1253        if (!retval)
1254                return NULL;
1255
1256        auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1257        auth_hdr.shkey_id = htons(asoc->active_key_id);
1258
1259        retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1260                                                &auth_hdr);
1261
1262        hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1263        memset(hmac, 0, hmac_desc->hmac_len);
1264
1265        /* Adjust the chunk header to include the empty MAC */
1266        retval->chunk_hdr->length =
1267                htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1268        retval->chunk_end = skb_tail_pointer(retval->skb);
1269
1270        return retval;
1271}
1272
1273
1274/********************************************************************
1275 * 2nd Level Abstractions
1276 ********************************************************************/
1277
1278/* Turn an skb into a chunk.
1279 * FIXME: Eventually move the structure directly inside the skb->cb[].
1280 */
1281struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1282                            const struct sctp_association *asoc,
1283                            struct sock *sk)
1284{
1285        struct sctp_chunk *retval;
1286
1287        retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1288
1289        if (!retval)
1290                goto nodata;
1291
1292        if (!sk) {
1293                SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
1294        }
1295
1296        INIT_LIST_HEAD(&retval->list);
1297        retval->skb             = skb;
1298        retval->asoc            = (struct sctp_association *)asoc;
1299        retval->has_tsn         = 0;
1300        retval->has_ssn         = 0;
1301        retval->rtt_in_progress = 0;
1302        retval->sent_at         = 0;
1303        retval->singleton       = 1;
1304        retval->end_of_packet   = 0;
1305        retval->ecn_ce_done     = 0;
1306        retval->pdiscard        = 0;
1307
1308        /* sctpimpguide-05.txt Section 2.8.2
1309         * M1) Each time a new DATA chunk is transmitted
1310         * set the 'TSN.Missing.Report' count for that TSN to 0. The
1311         * 'TSN.Missing.Report' count will be used to determine missing chunks
1312         * and when to fast retransmit.
1313         */
1314        retval->tsn_missing_report = 0;
1315        retval->tsn_gap_acked = 0;
1316        retval->fast_retransmit = SCTP_CAN_FRTX;
1317
1318        /* If this is a fragmented message, track all fragments
1319         * of the message (for SEND_FAILED).
1320         */
1321        retval->msg = NULL;
1322
1323        /* Polish the bead hole.  */
1324        INIT_LIST_HEAD(&retval->transmitted_list);
1325        INIT_LIST_HEAD(&retval->frag_list);
1326        SCTP_DBG_OBJCNT_INC(chunk);
1327        atomic_set(&retval->refcnt, 1);
1328
1329nodata:
1330        return retval;
1331}
1332
1333/* Set chunk->source and dest based on the IP header in chunk->skb.  */
1334void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1335                     union sctp_addr *dest)
1336{
1337        memcpy(&chunk->source, src, sizeof(union sctp_addr));
1338        memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1339}
1340
1341/* Extract the source address from a chunk.  */
1342const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1343{
1344        /* If we have a known transport, use that.  */
1345        if (chunk->transport) {
1346                return &chunk->transport->ipaddr;
1347        } else {
1348                /* Otherwise, extract it from the IP header.  */
1349                return &chunk->source;
1350        }
1351}
1352
1353/* Create a new chunk, setting the type and flags headers from the
1354 * arguments, reserving enough space for a 'paylen' byte payload.
1355 */
1356SCTP_STATIC
1357struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
1358                                   __u8 type, __u8 flags, int paylen)
1359{
1360        struct sctp_chunk *retval;
1361        sctp_chunkhdr_t *chunk_hdr;
1362        struct sk_buff *skb;
1363        struct sock *sk;
1364
1365        /* No need to allocate LL here, as this is only a chunk. */
1366        skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1367                        GFP_ATOMIC);
1368        if (!skb)
1369                goto nodata;
1370
1371        /* Make room for the chunk header.  */
1372        chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1373        chunk_hdr->type   = type;
1374        chunk_hdr->flags  = flags;
1375        chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1376
1377        sk = asoc ? asoc->base.sk : NULL;
1378        retval = sctp_chunkify(skb, asoc, sk);
1379        if (!retval) {
1380                kfree_skb(skb);
1381                goto nodata;
1382        }
1383
1384        retval->chunk_hdr = chunk_hdr;
1385        retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1386
1387        /* Determine if the chunk needs to be authenticated */
1388        if (sctp_auth_send_cid(type, asoc))
1389                retval->auth = 1;
1390
1391        /* Set the skb to the belonging sock for accounting.  */
1392        skb->sk = sk;
1393
1394        return retval;
1395nodata:
1396        return NULL;
1397}
1398
1399
1400/* Release the memory occupied by a chunk.  */
1401static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1402{
1403        BUG_ON(!list_empty(&chunk->list));
1404        list_del_init(&chunk->transmitted_list);
1405
1406        /* Free the chunk skb data and the SCTP_chunk stub itself. */
1407        dev_kfree_skb(chunk->skb);
1408
1409        SCTP_DBG_OBJCNT_DEC(chunk);
1410        kmem_cache_free(sctp_chunk_cachep, chunk);
1411}
1412
1413/* Possibly, free the chunk.  */
1414void sctp_chunk_free(struct sctp_chunk *chunk)
1415{
1416        /* Release our reference on the message tracker. */
1417        if (chunk->msg)
1418                sctp_datamsg_put(chunk->msg);
1419
1420        sctp_chunk_put(chunk);
1421}
1422
1423/* Grab a reference to the chunk. */
1424void sctp_chunk_hold(struct sctp_chunk *ch)
1425{
1426        atomic_inc(&ch->refcnt);
1427}
1428
1429/* Release a reference to the chunk. */
1430void sctp_chunk_put(struct sctp_chunk *ch)
1431{
1432        if (atomic_dec_and_test(&ch->refcnt))
1433                sctp_chunk_destroy(ch);
1434}
1435
1436/* Append bytes to the end of a chunk.  Will panic if chunk is not big
1437 * enough.
1438 */
1439void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1440{
1441        void *target;
1442        void *padding;
1443        int chunklen = ntohs(chunk->chunk_hdr->length);
1444        int padlen = WORD_ROUND(chunklen) - chunklen;
1445
1446        padding = skb_put(chunk->skb, padlen);
1447        target = skb_put(chunk->skb, len);
1448
1449        memset(padding, 0, padlen);
1450        memcpy(target, data, len);
1451
1452        /* Adjust the chunk length field.  */
1453        chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1454        chunk->chunk_end = skb_tail_pointer(chunk->skb);
1455
1456        return target;
1457}
1458
1459/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1460 * space in the chunk
1461 */
1462void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1463                             int len, const void *data)
1464{
1465        if (skb_tailroom(chunk->skb) >= len)
1466                return sctp_addto_chunk(chunk, len, data);
1467        else
1468                return NULL;
1469}
1470
1471/* Append bytes from user space to the end of a chunk.  Will panic if
1472 * chunk is not big enough.
1473 * Returns a kernel err value.
1474 */
1475int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
1476                          struct iovec *data)
1477{
1478        __u8 *target;
1479        int err = 0;
1480
1481        /* Make room in chunk for data.  */
1482        target = skb_put(chunk->skb, len);
1483
1484        /* Copy data (whole iovec) into chunk */
1485        if ((err = memcpy_fromiovecend(target, data, off, len)))
1486                goto out;
1487
1488        /* Adjust the chunk length field.  */
1489        chunk->chunk_hdr->length =
1490                htons(ntohs(chunk->chunk_hdr->length) + len);
1491        chunk->chunk_end = skb_tail_pointer(chunk->skb);
1492
1493out:
1494        return err;
1495}
1496
1497/* Helper function to assign a TSN if needed.  This assumes that both
1498 * the data_hdr and association have already been assigned.
1499 */
1500void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1501{
1502        struct sctp_datamsg *msg;
1503        struct sctp_chunk *lchunk;
1504        struct sctp_stream *stream;
1505        __u16 ssn;
1506        __u16 sid;
1507
1508        if (chunk->has_ssn)
1509                return;
1510
1511        /* All fragments will be on the same stream */
1512        sid = ntohs(chunk->subh.data_hdr->stream);
1513        stream = &chunk->asoc->ssnmap->out;
1514
1515        /* Now assign the sequence number to the entire message.
1516         * All fragments must have the same stream sequence number.
1517         */
1518        msg = chunk->msg;
1519        list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1520                if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1521                        ssn = 0;
1522                } else {
1523                        if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1524                                ssn = sctp_ssn_next(stream, sid);
1525                        else
1526                                ssn = sctp_ssn_peek(stream, sid);
1527                }
1528
1529                lchunk->subh.data_hdr->ssn = htons(ssn);
1530                lchunk->has_ssn = 1;
1531        }
1532}
1533
1534/* Helper function to assign a TSN if needed.  This assumes that both
1535 * the data_hdr and association have already been assigned.
1536 */
1537void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1538{
1539        if (!chunk->has_tsn) {
1540                /* This is the last possible instant to
1541                 * assign a TSN.
1542                 */
1543                chunk->subh.data_hdr->tsn =
1544                        htonl(sctp_association_get_next_tsn(chunk->asoc));
1545                chunk->has_tsn = 1;
1546        }
1547}
1548
1549/* Create a CLOSED association to use with an incoming packet.  */
1550struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1551                                        struct sctp_chunk *chunk,
1552                                        gfp_t gfp)
1553{
1554        struct sctp_association *asoc;
1555        struct sk_buff *skb;
1556        sctp_scope_t scope;
1557        struct sctp_af *af;
1558
1559        /* Create the bare association.  */
1560        scope = sctp_scope(sctp_source(chunk));
1561        asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1562        if (!asoc)
1563                goto nodata;
1564        asoc->temp = 1;
1565        skb = chunk->skb;
1566        /* Create an entry for the source address of the packet.  */
1567        af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1568        if (unlikely(!af))
1569                goto fail;
1570        af->from_skb(&asoc->c.peer_addr, skb, 1);
1571nodata:
1572        return asoc;
1573
1574fail:
1575        sctp_association_free(asoc);
1576        return NULL;
1577}
1578
1579/* Build a cookie representing asoc.
1580 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1581 */
1582static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1583                                      const struct sctp_association *asoc,
1584                                      const struct sctp_chunk *init_chunk,
1585                                      int *cookie_len,
1586                                      const __u8 *raw_addrs, int addrs_len)
1587{
1588        sctp_cookie_param_t *retval;
1589        struct sctp_signed_cookie *cookie;
1590        struct scatterlist sg;
1591        int headersize, bodysize;
1592        unsigned int keylen;
1593        char *key;
1594
1595        /* Header size is static data prior to the actual cookie, including
1596         * any padding.
1597         */
1598        headersize = sizeof(sctp_paramhdr_t) +
1599                     (sizeof(struct sctp_signed_cookie) -
1600                      sizeof(struct sctp_cookie));
1601        bodysize = sizeof(struct sctp_cookie)
1602                + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1603
1604        /* Pad out the cookie to a multiple to make the signature
1605         * functions simpler to write.
1606         */
1607        if (bodysize % SCTP_COOKIE_MULTIPLE)
1608                bodysize += SCTP_COOKIE_MULTIPLE
1609                        - (bodysize % SCTP_COOKIE_MULTIPLE);
1610        *cookie_len = headersize + bodysize;
1611
1612        /* Clear this memory since we are sending this data structure
1613         * out on the network.
1614         */
1615        retval = kzalloc(*cookie_len, GFP_ATOMIC);
1616        if (!retval)
1617                goto nodata;
1618
1619        cookie = (struct sctp_signed_cookie *) retval->body;
1620
1621        /* Set up the parameter header.  */
1622        retval->p.type = SCTP_PARAM_STATE_COOKIE;
1623        retval->p.length = htons(*cookie_len);
1624
1625        /* Copy the cookie part of the association itself.  */
1626        cookie->c = asoc->c;
1627        /* Save the raw address list length in the cookie. */
1628        cookie->c.raw_addr_list_len = addrs_len;
1629
1630        /* Remember PR-SCTP capability. */
1631        cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1632
1633        /* Save adaptation indication in the cookie. */
1634        cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1635
1636        /* Set an expiration time for the cookie.  */
1637        do_gettimeofday(&cookie->c.expiration);
1638        TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);
1639
1640        /* Copy the peer's init packet.  */
1641        memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1642               ntohs(init_chunk->chunk_hdr->length));
1643
1644        /* Copy the raw local address list of the association. */
1645        memcpy((__u8 *)&cookie->c.peer_init[0] +
1646               ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1647
1648        if (sctp_sk(ep->base.sk)->hmac) {
1649                struct hash_desc desc;
1650
1651                /* Sign the message.  */
1652                sg_init_one(&sg, &cookie->c, bodysize);
1653                keylen = SCTP_SECRET_SIZE;
1654                key = (char *)ep->secret_key[ep->current_key];
1655                desc.tfm = sctp_sk(ep->base.sk)->hmac;
1656                desc.flags = 0;
1657
1658                if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1659                    crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
1660                        goto free_cookie;
1661        }
1662
1663        return retval;
1664
1665free_cookie:
1666        kfree(retval);
1667nodata:
1668        *cookie_len = 0;
1669        return NULL;
1670}
1671
1672/* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
1673struct sctp_association *sctp_unpack_cookie(
1674        const struct sctp_endpoint *ep,
1675        const struct sctp_association *asoc,
1676        struct sctp_chunk *chunk, gfp_t gfp,
1677        int *error, struct sctp_chunk **errp)
1678{
1679        struct sctp_association *retval = NULL;
1680        struct sctp_signed_cookie *cookie;
1681        struct sctp_cookie *bear_cookie;
1682        int headersize, bodysize, fixed_size;
1683        __u8 *digest = ep->digest;
1684        struct scatterlist sg;
1685        unsigned int keylen, len;
1686        char *key;
1687        sctp_scope_t scope;
1688        struct sk_buff *skb = chunk->skb;
1689        struct timeval tv;
1690        struct hash_desc desc;
1691
1692        /* Header size is static data prior to the actual cookie, including
1693         * any padding.
1694         */
1695        headersize = sizeof(sctp_chunkhdr_t) +
1696                     (sizeof(struct sctp_signed_cookie) -
1697                      sizeof(struct sctp_cookie));
1698        bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1699        fixed_size = headersize + sizeof(struct sctp_cookie);
1700
1701        /* Verify that the chunk looks like it even has a cookie.
1702         * There must be enough room for our cookie and our peer's
1703         * INIT chunk.
1704         */
1705        len = ntohs(chunk->chunk_hdr->length);
1706        if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1707                goto malformed;
1708
1709        /* Verify that the cookie has been padded out. */
1710        if (bodysize % SCTP_COOKIE_MULTIPLE)
1711                goto malformed;
1712
1713        /* Process the cookie.  */
1714        cookie = chunk->subh.cookie_hdr;
1715        bear_cookie = &cookie->c;
1716
1717        if (!sctp_sk(ep->base.sk)->hmac)
1718                goto no_hmac;
1719
1720        /* Check the signature.  */
1721        keylen = SCTP_SECRET_SIZE;
1722        sg_init_one(&sg, bear_cookie, bodysize);
1723        key = (char *)ep->secret_key[ep->current_key];
1724        desc.tfm = sctp_sk(ep->base.sk)->hmac;
1725        desc.flags = 0;
1726
1727        memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1728        if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1729            crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1730                *error = -SCTP_IERROR_NOMEM;
1731                goto fail;
1732        }
1733
1734        if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1735                /* Try the previous key. */
1736                key = (char *)ep->secret_key[ep->last_key];
1737                memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1738                if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1739                    crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1740                        *error = -SCTP_IERROR_NOMEM;
1741                        goto fail;
1742                }
1743
1744                if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1745                        /* Yikes!  Still bad signature! */
1746                        *error = -SCTP_IERROR_BAD_SIG;
1747                        goto fail;
1748                }
1749        }
1750
1751no_hmac:
1752        /* IG Section 2.35.2:
1753         *  3) Compare the port numbers and the verification tag contained
1754         *     within the COOKIE ECHO chunk to the actual port numbers and the
1755         *     verification tag within the SCTP common header of the received
1756         *     packet. If these values do not match the packet MUST be silently
1757         *     discarded,
1758         */
1759        if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1760                *error = -SCTP_IERROR_BAD_TAG;
1761                goto fail;
1762        }
1763
1764        if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1765            ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1766                *error = -SCTP_IERROR_BAD_PORTS;
1767                goto fail;
1768        }
1769
1770        /* Check to see if the cookie is stale.  If there is already
1771         * an association, there is no need to check cookie's expiration
1772         * for init collision case of lost COOKIE ACK.
1773         * If skb has been timestamped, then use the stamp, otherwise
1774         * use current time.  This introduces a small possibility that
1775         * that a cookie may be considered expired, but his would only slow
1776         * down the new association establishment instead of every packet.
1777         */
1778        if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1779                skb_get_timestamp(skb, &tv);
1780        else
1781                do_gettimeofday(&tv);
1782
1783        if (!asoc && tv_lt(bear_cookie->expiration, tv)) {
1784                /*
1785                 * Section 3.3.10.3 Stale Cookie Error (3)
1786                 *
1787                 * Cause of error
1788                 * ---------------
1789                 * Stale Cookie Error:  Indicates the receipt of a valid State
1790                 * Cookie that has expired.
1791                 */
1792                len = ntohs(chunk->chunk_hdr->length);
1793                *errp = sctp_make_op_error_space(asoc, chunk, len);
1794                if (*errp) {
1795                        suseconds_t usecs = (tv.tv_sec -
1796                                bear_cookie->expiration.tv_sec) * 1000000L +
1797                                tv.tv_usec - bear_cookie->expiration.tv_usec;
1798                        __be32 n = htonl(usecs);
1799
1800                        sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1801                                        sizeof(n));
1802                        sctp_addto_chunk(*errp, sizeof(n), &n);
1803                        *error = -SCTP_IERROR_STALE_COOKIE;
1804                } else
1805                        *error = -SCTP_IERROR_NOMEM;
1806
1807                goto fail;
1808        }
1809
1810        /* Make a new base association.  */
1811        scope = sctp_scope(sctp_source(chunk));
1812        retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1813        if (!retval) {
1814                *error = -SCTP_IERROR_NOMEM;
1815                goto fail;
1816        }
1817
1818        /* Set up our peer's port number.  */
1819        retval->peer.port = ntohs(chunk->sctp_hdr->source);
1820
1821        /* Populate the association from the cookie.  */
1822        memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1823
1824        if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1825                                                 GFP_ATOMIC) < 0) {
1826                *error = -SCTP_IERROR_NOMEM;
1827                goto fail;
1828        }
1829
1830        /* Also, add the destination address. */
1831        if (list_empty(&retval->base.bind_addr.address_list)) {
1832                sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1833                                SCTP_ADDR_SRC, GFP_ATOMIC);
1834        }
1835
1836        retval->next_tsn = retval->c.initial_tsn;
1837        retval->ctsn_ack_point = retval->next_tsn - 1;
1838        retval->addip_serial = retval->c.initial_tsn;
1839        retval->adv_peer_ack_point = retval->ctsn_ack_point;
1840        retval->peer.prsctp_capable = retval->c.prsctp_capable;
1841        retval->peer.adaptation_ind = retval->c.adaptation_ind;
1842
1843        /* The INIT stuff will be done by the side effects.  */
1844        return retval;
1845
1846fail:
1847        if (retval)
1848                sctp_association_free(retval);
1849
1850        return NULL;
1851
1852malformed:
1853        /* Yikes!  The packet is either corrupt or deliberately
1854         * malformed.
1855         */
1856        *error = -SCTP_IERROR_MALFORMED;
1857        goto fail;
1858}
1859
1860/********************************************************************
1861 * 3rd Level Abstractions
1862 ********************************************************************/
1863
1864struct __sctp_missing {
1865        __be32 num_missing;
1866        __be16 type;
1867}  __packed;
1868
1869/*
1870 * Report a missing mandatory parameter.
1871 */
1872static int sctp_process_missing_param(const struct sctp_association *asoc,
1873                                      sctp_param_t paramtype,
1874                                      struct sctp_chunk *chunk,
1875                                      struct sctp_chunk **errp)
1876{
1877        struct __sctp_missing report;
1878        __u16 len;
1879
1880        len = WORD_ROUND(sizeof(report));
1881
1882        /* Make an ERROR chunk, preparing enough room for
1883         * returning multiple unknown parameters.
1884         */
1885        if (!*errp)
1886                *errp = sctp_make_op_error_space(asoc, chunk, len);
1887
1888        if (*errp) {
1889                report.num_missing = htonl(1);
1890                report.type = paramtype;
1891                sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1892                                sizeof(report));
1893                sctp_addto_chunk(*errp, sizeof(report), &report);
1894        }
1895
1896        /* Stop processing this chunk. */
1897        return 0;
1898}
1899
1900/* Report an Invalid Mandatory Parameter.  */
1901static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1902                                      struct sctp_chunk *chunk,
1903                                      struct sctp_chunk **errp)
1904{
1905        /* Invalid Mandatory Parameter Error has no payload. */
1906
1907        if (!*errp)
1908                *errp = sctp_make_op_error_space(asoc, chunk, 0);
1909
1910        if (*errp)
1911                sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1912
1913        /* Stop processing this chunk. */
1914        return 0;
1915}
1916
1917static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1918                                        struct sctp_paramhdr *param,
1919                                        const struct sctp_chunk *chunk,
1920                                        struct sctp_chunk **errp)
1921{
1922        /* This is a fatal error.  Any accumulated non-fatal errors are
1923         * not reported.
1924         */
1925        if (*errp)
1926                sctp_chunk_free(*errp);
1927
1928        /* Create an error chunk and fill it in with our payload. */
1929        *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1930
1931        return 0;
1932}
1933
1934
1935/* Do not attempt to handle the HOST_NAME parm.  However, do
1936 * send back an indicator to the peer.
1937 */
1938static int sctp_process_hn_param(const struct sctp_association *asoc,
1939                                 union sctp_params param,
1940                                 struct sctp_chunk *chunk,
1941                                 struct sctp_chunk **errp)
1942{
1943        __u16 len = ntohs(param.p->length);
1944
1945        /* Processing of the HOST_NAME parameter will generate an
1946         * ABORT.  If we've accumulated any non-fatal errors, they
1947         * would be unrecognized parameters and we should not include
1948         * them in the ABORT.
1949         */
1950        if (*errp)
1951                sctp_chunk_free(*errp);
1952
1953        *errp = sctp_make_op_error_space(asoc, chunk, len);
1954
1955        if (*errp) {
1956                sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1957                sctp_addto_chunk(*errp, len, param.v);
1958        }
1959
1960        /* Stop processing this chunk. */
1961        return 0;
1962}
1963
1964static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1965{
1966        __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1967        int have_auth = 0;
1968        int have_asconf = 0;
1969        int i;
1970
1971        for (i = 0; i < num_ext; i++) {
1972                switch (param.ext->chunks[i]) {
1973                    case SCTP_CID_AUTH:
1974                            have_auth = 1;
1975                            break;
1976                    case SCTP_CID_ASCONF:
1977                    case SCTP_CID_ASCONF_ACK:
1978                            have_asconf = 1;
1979                            break;
1980                }
1981        }
1982
1983        /* ADD-IP Security: The draft requires us to ABORT or ignore the
1984         * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not.  Do this
1985         * only if ADD-IP is turned on and we are not backward-compatible
1986         * mode.
1987         */
1988        if (net->sctp.addip_noauth)
1989                return 1;
1990
1991        if (net->sctp.addip_enable && !have_auth && have_asconf)
1992                return 0;
1993
1994        return 1;
1995}
1996
1997static void sctp_process_ext_param(struct sctp_association *asoc,
1998                                    union sctp_params param)
1999{
2000        struct net *net = sock_net(asoc->base.sk);
2001        __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2002        int i;
2003
2004        for (i = 0; i < num_ext; i++) {
2005                switch (param.ext->chunks[i]) {
2006                    case SCTP_CID_FWD_TSN:
2007                            if (net->sctp.prsctp_enable &&
2008                                !asoc->peer.prsctp_capable)
2009                                    asoc->peer.prsctp_capable = 1;
2010                            break;
2011                    case SCTP_CID_AUTH:
2012                            /* if the peer reports AUTH, assume that he
2013                             * supports AUTH.
2014                             */
2015                            if (net->sctp.auth_enable)
2016                                    asoc->peer.auth_capable = 1;
2017                            break;
2018                    case SCTP_CID_ASCONF:
2019                    case SCTP_CID_ASCONF_ACK:
2020                            if (net->sctp.addip_enable)
2021                                    asoc->peer.asconf_capable = 1;
2022                            break;
2023                    default:
2024                            break;
2025                }
2026        }
2027}
2028
2029/* RFC 3.2.1 & the Implementers Guide 2.2.
2030 *
2031 * The Parameter Types are encoded such that the
2032 * highest-order two bits specify the action that must be
2033 * taken if the processing endpoint does not recognize the
2034 * Parameter Type.
2035 *
2036 * 00 - Stop processing this parameter; do not process any further
2037 *      parameters within this chunk
2038 *
2039 * 01 - Stop processing this parameter, do not process any further
2040 *      parameters within this chunk, and report the unrecognized
2041 *      parameter in an 'Unrecognized Parameter' ERROR chunk.
2042 *
2043 * 10 - Skip this parameter and continue processing.
2044 *
2045 * 11 - Skip this parameter and continue processing but
2046 *      report the unrecognized parameter in an
2047 *      'Unrecognized Parameter' ERROR chunk.
2048 *
2049 * Return value:
2050 *      SCTP_IERROR_NO_ERROR - continue with the chunk
2051 *      SCTP_IERROR_ERROR    - stop and report an error.
2052 *      SCTP_IERROR_NOMEME   - out of memory.
2053 */
2054static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2055                                            union sctp_params param,
2056                                            struct sctp_chunk *chunk,
2057                                            struct sctp_chunk **errp)
2058{
2059        int retval = SCTP_IERROR_NO_ERROR;
2060
2061        switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2062        case SCTP_PARAM_ACTION_DISCARD:
2063                retval =  SCTP_IERROR_ERROR;
2064                break;
2065        case SCTP_PARAM_ACTION_SKIP:
2066                break;
2067        case SCTP_PARAM_ACTION_DISCARD_ERR:
2068                retval =  SCTP_IERROR_ERROR;
2069                /* Fall through */
2070        case SCTP_PARAM_ACTION_SKIP_ERR:
2071                /* Make an ERROR chunk, preparing enough room for
2072                 * returning multiple unknown parameters.
2073                 */
2074                if (NULL == *errp)
2075                        *errp = sctp_make_op_error_fixed(asoc, chunk);
2076
2077                if (*errp) {
2078                        if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2079                                        WORD_ROUND(ntohs(param.p->length))))
2080                                sctp_addto_chunk_fixed(*errp,
2081                                                WORD_ROUND(ntohs(param.p->length)),
2082                                                param.v);
2083                } else {
2084                        /* If there is no memory for generating the ERROR
2085                         * report as specified, an ABORT will be triggered
2086                         * to the peer and the association won't be
2087                         * established.
2088                         */
2089                        retval = SCTP_IERROR_NOMEM;
2090                }
2091                break;
2092        default:
2093                break;
2094        }
2095
2096        return retval;
2097}
2098
2099/* Verify variable length parameters
2100 * Return values:
2101 *      SCTP_IERROR_ABORT - trigger an ABORT
2102 *      SCTP_IERROR_NOMEM - out of memory (abort)
2103 *      SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2104 *      SCTP_IERROR_NO_ERROR - continue with the chunk
2105 */
2106static sctp_ierror_t sctp_verify_param(struct net *net,
2107                                        const struct sctp_association *asoc,
2108                                        union sctp_params param,
2109                                        sctp_cid_t cid,
2110                                        struct sctp_chunk *chunk,
2111                                        struct sctp_chunk **err_chunk)
2112{
2113        struct sctp_hmac_algo_param *hmacs;
2114        int retval = SCTP_IERROR_NO_ERROR;
2115        __u16 n_elt, id = 0;
2116        int i;
2117
2118        /* FIXME - This routine is not looking at each parameter per the
2119         * chunk type, i.e., unrecognized parameters should be further
2120         * identified based on the chunk id.
2121         */
2122
2123        switch (param.p->type) {
2124        case SCTP_PARAM_IPV4_ADDRESS:
2125        case SCTP_PARAM_IPV6_ADDRESS:
2126        case SCTP_PARAM_COOKIE_PRESERVATIVE:
2127        case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2128        case SCTP_PARAM_STATE_COOKIE:
2129        case SCTP_PARAM_HEARTBEAT_INFO:
2130        case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2131        case SCTP_PARAM_ECN_CAPABLE:
2132        case SCTP_PARAM_ADAPTATION_LAYER_IND:
2133                break;
2134
2135        case SCTP_PARAM_SUPPORTED_EXT:
2136                if (!sctp_verify_ext_param(net, param))
2137                        return SCTP_IERROR_ABORT;
2138                break;
2139
2140        case SCTP_PARAM_SET_PRIMARY:
2141                if (net->sctp.addip_enable)
2142                        break;
2143                goto fallthrough;
2144
2145        case SCTP_PARAM_HOST_NAME_ADDRESS:
2146                /* Tell the peer, we won't support this param.  */
2147                sctp_process_hn_param(asoc, param, chunk, err_chunk);
2148                retval = SCTP_IERROR_ABORT;
2149                break;
2150
2151        case SCTP_PARAM_FWD_TSN_SUPPORT:
2152                if (net->sctp.prsctp_enable)
2153                        break;
2154                goto fallthrough;
2155
2156        case SCTP_PARAM_RANDOM:
2157                if (!net->sctp.auth_enable)
2158                        goto fallthrough;
2159
2160                /* SCTP-AUTH: Secion 6.1
2161                 * If the random number is not 32 byte long the association
2162                 * MUST be aborted.  The ABORT chunk SHOULD contain the error
2163                 * cause 'Protocol Violation'.
2164                 */
2165                if (SCTP_AUTH_RANDOM_LENGTH !=
2166                        ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2167                        sctp_process_inv_paramlength(asoc, param.p,
2168                                                        chunk, err_chunk);
2169                        retval = SCTP_IERROR_ABORT;
2170                }
2171                break;
2172
2173        case SCTP_PARAM_CHUNKS:
2174                if (!net->sctp.auth_enable)
2175                        goto fallthrough;
2176
2177                /* SCTP-AUTH: Section 3.2
2178                 * The CHUNKS parameter MUST be included once in the INIT or
2179                 *  INIT-ACK chunk if the sender wants to receive authenticated
2180                 *  chunks.  Its maximum length is 260 bytes.
2181                 */
2182                if (260 < ntohs(param.p->length)) {
2183                        sctp_process_inv_paramlength(asoc, param.p,
2184                                                     chunk, err_chunk);
2185                        retval = SCTP_IERROR_ABORT;
2186                }
2187                break;
2188
2189        case SCTP_PARAM_HMAC_ALGO:
2190                if (!net->sctp.auth_enable)
2191                        goto fallthrough;
2192
2193                hmacs = (struct sctp_hmac_algo_param *)param.p;
2194                n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2195
2196                /* SCTP-AUTH: Section 6.1
2197                 * The HMAC algorithm based on SHA-1 MUST be supported and
2198                 * included in the HMAC-ALGO parameter.
2199                 */
2200                for (i = 0; i < n_elt; i++) {
2201                        id = ntohs(hmacs->hmac_ids[i]);
2202
2203                        if (id == SCTP_AUTH_HMAC_ID_SHA1)
2204                                break;
2205                }
2206
2207                if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2208                        sctp_process_inv_paramlength(asoc, param.p, chunk,
2209                                                     err_chunk);
2210                        retval = SCTP_IERROR_ABORT;
2211                }
2212                break;
2213fallthrough:
2214        default:
2215                SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
2216                                ntohs(param.p->type), cid);
2217                retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2218                break;
2219        }
2220        return retval;
2221}
2222
2223/* Verify the INIT packet before we process it.  */
2224int sctp_verify_init(struct net *net, const struct sctp_association *asoc,
2225                     sctp_cid_t cid,
2226                     sctp_init_chunk_t *peer_init,
2227                     struct sctp_chunk *chunk,
2228                     struct sctp_chunk **errp)
2229{
2230        union sctp_params param;
2231        int has_cookie = 0;
2232        int result;
2233
2234        /* Verify stream values are non-zero. */
2235        if ((0 == peer_init->init_hdr.num_outbound_streams) ||
2236            (0 == peer_init->init_hdr.num_inbound_streams) ||
2237            (0 == peer_init->init_hdr.init_tag) ||
2238            (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {
2239
2240                return sctp_process_inv_mandatory(asoc, chunk, errp);
2241        }
2242
2243        /* Check for missing mandatory parameters.  */
2244        sctp_walk_params(param, peer_init, init_hdr.params) {
2245
2246                if (SCTP_PARAM_STATE_COOKIE == param.p->type)
2247                        has_cookie = 1;
2248
2249        } /* for (loop through all parameters) */
2250
2251        /* There is a possibility that a parameter length was bad and
2252         * in that case we would have stoped walking the parameters.
2253         * The current param.p would point at the bad one.
2254         * Current consensus on the mailing list is to generate a PROTOCOL
2255         * VIOLATION error.  We build the ERROR chunk here and let the normal
2256         * error handling code build and send the packet.
2257         */
2258        if (param.v != (void*)chunk->chunk_end)
2259                return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2260
2261        /* The only missing mandatory param possible today is
2262         * the state cookie for an INIT-ACK chunk.
2263         */
2264        if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2265                return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2266                                                  chunk, errp);
2267
2268        /* Verify all the variable length parameters */
2269        sctp_walk_params(param, peer_init, init_hdr.params) {
2270
2271                result = sctp_verify_param(net, asoc, param, cid, chunk, errp);
2272                switch (result) {
2273                    case SCTP_IERROR_ABORT:
2274                    case SCTP_IERROR_NOMEM:
2275                                return 0;
2276                    case SCTP_IERROR_ERROR:
2277                                return 1;
2278                    case SCTP_IERROR_NO_ERROR:
2279                    default:
2280                                break;
2281                }
2282
2283        } /* for (loop through all parameters) */
2284
2285        return 1;
2286}
2287
2288/* Unpack the parameters in an INIT packet into an association.
2289 * Returns 0 on failure, else success.
2290 * FIXME:  This is an association method.
2291 */
2292int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2293                      const union sctp_addr *peer_addr,
2294                      sctp_init_chunk_t *peer_init, gfp_t gfp)
2295{
2296        struct net *net = sock_net(asoc->base.sk);
2297        union sctp_params param;
2298        struct sctp_transport *transport;
2299        struct list_head *pos, *temp;
2300        struct sctp_af *af;
2301        union sctp_addr addr;
2302        char *cookie;
2303        int src_match = 0;
2304
2305        /* We must include the address that the INIT packet came from.
2306         * This is the only address that matters for an INIT packet.
2307         * When processing a COOKIE ECHO, we retrieve the from address
2308         * of the INIT from the cookie.
2309         */
2310
2311        /* This implementation defaults to making the first transport
2312         * added as the primary transport.  The source address seems to
2313         * be a a better choice than any of the embedded addresses.
2314         */
2315        if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2316                goto nomem;
2317
2318        if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2319                src_match = 1;
2320
2321        /* Process the initialization parameters.  */
2322        sctp_walk_params(param, peer_init, init_hdr.params) {
2323                if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2324                    param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2325                        af = sctp_get_af_specific(param_type2af(param.p->type));
2326                        af->from_addr_param(&addr, param.addr,
2327                                            chunk->sctp_hdr->source, 0);
2328                        if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2329                                src_match = 1;
2330                }
2331
2332                if (!sctp_process_param(asoc, param, peer_addr, gfp))
2333                        goto clean_up;
2334        }
2335
2336        /* source address of chunk may not match any valid address */
2337        if (!src_match)
2338                goto clean_up;
2339
2340        /* AUTH: After processing the parameters, make sure that we
2341         * have all the required info to potentially do authentications.
2342         */
2343        if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2344                                        !asoc->peer.peer_hmacs))
2345                asoc->peer.auth_capable = 0;
2346
2347        /* In a non-backward compatible mode, if the peer claims
2348         * support for ADD-IP but not AUTH,  the ADD-IP spec states
2349         * that we MUST ABORT the association. Section 6.  The section
2350         * also give us an option to silently ignore the packet, which
2351         * is what we'll do here.
2352         */
2353        if (!net->sctp.addip_noauth &&
2354             (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2355                asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2356                                                  SCTP_PARAM_DEL_IP |
2357                                                  SCTP_PARAM_SET_PRIMARY);
2358                asoc->peer.asconf_capable = 0;
2359                goto clean_up;
2360        }
2361
2362        /* Walk list of transports, removing transports in the UNKNOWN state. */
2363        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2364                transport = list_entry(pos, struct sctp_transport, transports);
2365                if (transport->state == SCTP_UNKNOWN) {
2366                        sctp_assoc_rm_peer(asoc, transport);
2367                }
2368        }
2369
2370        /* The fixed INIT headers are always in network byte
2371         * order.
2372         */
2373        asoc->peer.i.init_tag =
2374                ntohl(peer_init->init_hdr.init_tag);
2375        asoc->peer.i.a_rwnd =
2376                ntohl(peer_init->init_hdr.a_rwnd);
2377        asoc->peer.i.num_outbound_streams =
2378                ntohs(peer_init->init_hdr.num_outbound_streams);
2379        asoc->peer.i.num_inbound_streams =
2380                ntohs(peer_init->init_hdr.num_inbound_streams);
2381        asoc->peer.i.initial_tsn =
2382                ntohl(peer_init->init_hdr.initial_tsn);
2383
2384        /* Apply the upper bounds for output streams based on peer's
2385         * number of inbound streams.
2386         */
2387        if (asoc->c.sinit_num_ostreams  >
2388            ntohs(peer_init->init_hdr.num_inbound_streams)) {
2389                asoc->c.sinit_num_ostreams =
2390                        ntohs(peer_init->init_hdr.num_inbound_streams);
2391        }
2392
2393        if (asoc->c.sinit_max_instreams >
2394            ntohs(peer_init->init_hdr.num_outbound_streams)) {
2395                asoc->c.sinit_max_instreams =
2396                        ntohs(peer_init->init_hdr.num_outbound_streams);
2397        }
2398
2399        /* Copy Initiation tag from INIT to VT_peer in cookie.   */
2400        asoc->c.peer_vtag = asoc->peer.i.init_tag;
2401
2402        /* Peer Rwnd   : Current calculated value of the peer's rwnd.  */
2403        asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2404
2405        /* Copy cookie in case we need to resend COOKIE-ECHO. */
2406        cookie = asoc->peer.cookie;
2407        if (cookie) {
2408                asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2409                if (!asoc->peer.cookie)
2410                        goto clean_up;
2411        }
2412
2413        /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2414         * high (for example, implementations MAY use the size of the receiver
2415         * advertised window).
2416         */
2417        list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2418                        transports) {
2419                transport->ssthresh = asoc->peer.i.a_rwnd;
2420        }
2421
2422        /* Set up the TSN tracking pieces.  */
2423        if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2424                                asoc->peer.i.initial_tsn, gfp))
2425                goto clean_up;
2426
2427        /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2428         *
2429         * The stream sequence number in all the streams shall start
2430         * from 0 when the association is established.  Also, when the
2431         * stream sequence number reaches the value 65535 the next
2432         * stream sequence number shall be set to 0.
2433         */
2434
2435        /* Allocate storage for the negotiated streams if it is not a temporary
2436         * association.
2437         */
2438        if (!asoc->temp) {
2439                int error;
2440
2441                asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2442                                               asoc->c.sinit_num_ostreams, gfp);
2443                if (!asoc->ssnmap)
2444                        goto clean_up;
2445
2446                error = sctp_assoc_set_id(asoc, gfp);
2447                if (error)
2448                        goto clean_up;
2449        }
2450
2451        /* ADDIP Section 4.1 ASCONF Chunk Procedures
2452         *
2453         * When an endpoint has an ASCONF signaled change to be sent to the
2454         * remote endpoint it should do the following:
2455         * ...
2456         * A2) A serial number should be assigned to the Chunk. The serial
2457         * number should be a monotonically increasing number. All serial
2458         * numbers are defined to be initialized at the start of the
2459         * association to the same value as the Initial TSN.
2460         */
2461        asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2462        return 1;
2463
2464clean_up:
2465        /* Release the transport structures. */
2466        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2467                transport = list_entry(pos, struct sctp_transport, transports);
2468                if (transport->state != SCTP_ACTIVE)
2469                        sctp_assoc_rm_peer(asoc, transport);
2470        }
2471
2472nomem:
2473        return 0;
2474}
2475
2476
2477/* Update asoc with the option described in param.
2478 *
2479 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2480 *
2481 * asoc is the association to update.
2482 * param is the variable length parameter to use for update.
2483 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2484 * If the current packet is an INIT we want to minimize the amount of
2485 * work we do.  In particular, we should not build transport
2486 * structures for the addresses.
2487 */
2488static int sctp_process_param(struct sctp_association *asoc,
2489                              union sctp_params param,
2490                              const union sctp_addr *peer_addr,
2491                              gfp_t gfp)
2492{
2493        struct net *net = sock_net(asoc->base.sk);
2494        union sctp_addr addr;
2495        int i;
2496        __u16 sat;
2497        int retval = 1;
2498        sctp_scope_t scope;
2499        time_t stale;
2500        struct sctp_af *af;
2501        union sctp_addr_param *addr_param;
2502        struct sctp_transport *t;
2503
2504        /* We maintain all INIT parameters in network byte order all the
2505         * time.  This allows us to not worry about whether the parameters
2506         * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2507         */
2508        switch (param.p->type) {
2509        case SCTP_PARAM_IPV6_ADDRESS:
2510                if (PF_INET6 != asoc->base.sk->sk_family)
2511                        break;
2512                goto do_addr_param;
2513
2514        case SCTP_PARAM_IPV4_ADDRESS:
2515                /* v4 addresses are not allowed on v6-only socket */
2516                if (ipv6_only_sock(asoc->base.sk))
2517                        break;
2518do_addr_param:
2519                af = sctp_get_af_specific(param_type2af(param.p->type));
2520                af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2521                scope = sctp_scope(peer_addr);
2522                if (sctp_in_scope(net, &addr, scope))
2523                        if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2524                                return 0;
2525                break;
2526
2527        case SCTP_PARAM_COOKIE_PRESERVATIVE:
2528                if (!net->sctp.cookie_preserve_enable)
2529                        break;
2530
2531                stale = ntohl(param.life->lifespan_increment);
2532
2533                /* Suggested Cookie Life span increment's unit is msec,
2534                 * (1/1000sec).
2535                 */
2536                asoc->cookie_life.tv_sec += stale / 1000;
2537                asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
2538                break;
2539
2540        case SCTP_PARAM_HOST_NAME_ADDRESS:
2541                SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
2542                break;
2543
2544        case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2545                /* Turn off the default values first so we'll know which
2546                 * ones are really set by the peer.
2547                 */
2548                asoc->peer.ipv4_address = 0;
2549                asoc->peer.ipv6_address = 0;
2550
2551                /* Assume that peer supports the address family
2552                 * by which it sends a packet.
2553                 */
2554                if (peer_addr->sa.sa_family == AF_INET6)
2555                        asoc->peer.ipv6_address = 1;
2556                else if (peer_addr->sa.sa_family == AF_INET)
2557                        asoc->peer.ipv4_address = 1;
2558
2559                /* Cycle through address types; avoid divide by 0. */
2560                sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2561                if (sat)
2562                        sat /= sizeof(__u16);
2563
2564                for (i = 0; i < sat; ++i) {
2565                        switch (param.sat->types[i]) {
2566                        case SCTP_PARAM_IPV4_ADDRESS:
2567                                asoc->peer.ipv4_address = 1;
2568                                break;
2569
2570                        case SCTP_PARAM_IPV6_ADDRESS:
2571                                if (PF_INET6 == asoc->base.sk->sk_family)
2572                                        asoc->peer.ipv6_address = 1;
2573                                break;
2574
2575                        case SCTP_PARAM_HOST_NAME_ADDRESS:
2576                                asoc->peer.hostname_address = 1;
2577                                break;
2578
2579                        default: /* Just ignore anything else.  */
2580                                break;
2581                        }
2582                }
2583                break;
2584
2585        case SCTP_PARAM_STATE_COOKIE:
2586                asoc->peer.cookie_len =
2587                        ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2588                asoc->peer.cookie = param.cookie->body;
2589                break;
2590
2591        case SCTP_PARAM_HEARTBEAT_INFO:
2592                /* Would be odd to receive, but it causes no problems. */
2593                break;
2594
2595        case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2596                /* Rejected during verify stage. */
2597                break;
2598
2599        case SCTP_PARAM_ECN_CAPABLE:
2600                asoc->peer.ecn_capable = 1;
2601                break;
2602
2603        case SCTP_PARAM_ADAPTATION_LAYER_IND:
2604                asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2605                break;
2606
2607        case SCTP_PARAM_SET_PRIMARY:
2608                if (!net->sctp.addip_enable)
2609                        goto fall_through;
2610
2611                addr_param = param.v + sizeof(sctp_addip_param_t);
2612
2613                af = sctp_get_af_specific(param_type2af(param.p->type));
2614                af->from_addr_param(&addr, addr_param,
2615                                    htons(asoc->peer.port), 0);
2616
2617                /* if the address is invalid, we can't process it.
2618                 * XXX: see spec for what to do.
2619                 */
2620                if (!af->addr_valid(&addr, NULL, NULL))
2621                        break;
2622
2623                t = sctp_assoc_lookup_paddr(asoc, &addr);
2624                if (!t)
2625                        break;
2626
2627                sctp_assoc_set_primary(asoc, t);
2628                break;
2629
2630        case SCTP_PARAM_SUPPORTED_EXT:
2631                sctp_process_ext_param(asoc, param);
2632                break;
2633
2634        case SCTP_PARAM_FWD_TSN_SUPPORT:
2635                if (net->sctp.prsctp_enable) {
2636                        asoc->peer.prsctp_capable = 1;
2637                        break;
2638                }
2639                /* Fall Through */
2640                goto fall_through;
2641
2642        case SCTP_PARAM_RANDOM:
2643                if (!net->sctp.auth_enable)
2644                        goto fall_through;
2645
2646                /* Save peer's random parameter */
2647                asoc->peer.peer_random = kmemdup(param.p,
2648                                            ntohs(param.p->length), gfp);
2649                if (!asoc->peer.peer_random) {
2650                        retval = 0;
2651                        break;
2652                }
2653                break;
2654
2655        case SCTP_PARAM_HMAC_ALGO:
2656                if (!net->sctp.auth_enable)
2657                        goto fall_through;
2658
2659                /* Save peer's HMAC list */
2660                asoc->peer.peer_hmacs = kmemdup(param.p,
2661                                            ntohs(param.p->length), gfp);
2662                if (!asoc->peer.peer_hmacs) {
2663                        retval = 0;
2664                        break;
2665                }
2666
2667                /* Set the default HMAC the peer requested*/
2668                sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2669                break;
2670
2671        case SCTP_PARAM_CHUNKS:
2672                if (!net->sctp.auth_enable)
2673                        goto fall_through;
2674
2675                asoc->peer.peer_chunks = kmemdup(param.p,
2676                                            ntohs(param.p->length), gfp);
2677                if (!asoc->peer.peer_chunks)
2678                        retval = 0;
2679                break;
2680fall_through:
2681        default:
2682                /* Any unrecognized parameters should have been caught
2683                 * and handled by sctp_verify_param() which should be
2684                 * called prior to this routine.  Simply log the error
2685                 * here.
2686                 */
2687                SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n",
2688                                  ntohs(param.p->type), asoc);
2689                break;
2690        }
2691
2692        return retval;
2693}
2694
2695/* Select a new verification tag.  */
2696__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2697{
2698        /* I believe that this random number generator complies with RFC1750.
2699         * A tag of 0 is reserved for special cases (e.g. INIT).
2700         */
2701        __u32 x;
2702
2703        do {
2704                get_random_bytes(&x, sizeof(__u32));
2705        } while (x == 0);
2706
2707        return x;
2708}
2709
2710/* Select an initial TSN to send during startup.  */
2711__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2712{
2713        __u32 retval;
2714
2715        get_random_bytes(&retval, sizeof(__u32));
2716        return retval;
2717}
2718
2719/*
2720 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2721 *      0                   1                   2                   3
2722 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2723 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2724 *     | Type = 0xC1   |  Chunk Flags  |      Chunk Length             |
2725 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2726 *     |                       Serial Number                           |
2727 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2728 *     |                    Address Parameter                          |
2729 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2730 *     |                     ASCONF Parameter #1                       |
2731 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2732 *     \                                                               \
2733 *     /                             ....                              /
2734 *     \                                                               \
2735 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2736 *     |                     ASCONF Parameter #N                       |
2737 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2738 *
2739 * Address Parameter and other parameter will not be wrapped in this function
2740 */
2741static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2742                                           union sctp_addr *addr,
2743                                           int vparam_len)
2744{
2745        sctp_addiphdr_t asconf;
2746        struct sctp_chunk *retval;
2747        int length = sizeof(asconf) + vparam_len;
2748        union sctp_addr_param addrparam;
2749        int addrlen;
2750        struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2751
2752        addrlen = af->to_addr_param(addr, &addrparam);
2753        if (!addrlen)
2754                return NULL;
2755        length += addrlen;
2756
2757        /* Create the chunk.  */
2758        retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length);
2759        if (!retval)
2760                return NULL;
2761
2762        asconf.serial = htonl(asoc->addip_serial++);
2763
2764        retval->subh.addip_hdr =
2765                sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2766        retval->param_hdr.v =
2767                sctp_addto_chunk(retval, addrlen, &addrparam);
2768
2769        return retval;
2770}
2771
2772/* ADDIP
2773 * 3.2.1 Add IP Address
2774 *      0                   1                   2                   3
2775 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2776 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2777 *     |        Type = 0xC001          |    Length = Variable          |
2778 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2779 *     |               ASCONF-Request Correlation ID                   |
2780 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2781 *     |                       Address Parameter                       |
2782 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2783 *
2784 * 3.2.2 Delete IP Address
2785 *      0                   1                   2                   3
2786 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2787 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2788 *     |        Type = 0xC002          |    Length = Variable          |
2789 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2790 *     |               ASCONF-Request Correlation ID                   |
2791 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 *     |                       Address Parameter                       |
2793 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2794 *
2795 */
2796struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2797                                              union sctp_addr         *laddr,
2798                                              struct sockaddr         *addrs,
2799                                              int                     addrcnt,
2800                                              __be16                  flags)
2801{
2802        sctp_addip_param_t      param;
2803        struct sctp_chunk       *retval;
2804        union sctp_addr_param   addr_param;
2805        union sctp_addr         *addr;
2806        void                    *addr_buf;
2807        struct sctp_af          *af;
2808        int                     paramlen = sizeof(param);
2809        int                     addr_param_len = 0;
2810        int                     totallen = 0;
2811        int                     i;
2812        int                     del_pickup = 0;
2813
2814        /* Get total length of all the address parameters. */
2815        addr_buf = addrs;
2816        for (i = 0; i < addrcnt; i++) {
2817                addr = addr_buf;
2818                af = sctp_get_af_specific(addr->v4.sin_family);
2819                addr_param_len = af->to_addr_param(addr, &addr_param);
2820
2821                totallen += paramlen;
2822                totallen += addr_param_len;
2823
2824                addr_buf += af->sockaddr_len;
2825                if (asoc->asconf_addr_del_pending && !del_pickup) {
2826                        /* reuse the parameter length from the same scope one */
2827                        totallen += paramlen;
2828                        totallen += addr_param_len;
2829                        del_pickup = 1;
2830                        SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen);
2831                }
2832        }
2833
2834        /* Create an asconf chunk with the required length. */
2835        retval = sctp_make_asconf(asoc, laddr, totallen);
2836        if (!retval)
2837                return NULL;
2838
2839        /* Add the address parameters to the asconf chunk. */
2840        addr_buf = addrs;
2841        for (i = 0; i < addrcnt; i++) {
2842                addr = addr_buf;
2843                af = sctp_get_af_specific(addr->v4.sin_family);
2844                addr_param_len = af->to_addr_param(addr, &addr_param);
2845                param.param_hdr.type = flags;
2846                param.param_hdr.length = htons(paramlen + addr_param_len);
2847                param.crr_id = i;
2848
2849                sctp_addto_chunk(retval, paramlen, &param);
2850                sctp_addto_chunk(retval, addr_param_len, &addr_param);
2851
2852                addr_buf += af->sockaddr_len;
2853        }
2854        if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2855                addr = asoc->asconf_addr_del_pending;
2856                af = sctp_get_af_specific(addr->v4.sin_family);
2857                addr_param_len = af->to_addr_param(addr, &addr_param);
2858                param.param_hdr.type = SCTP_PARAM_DEL_IP;
2859                param.param_hdr.length = htons(paramlen + addr_param_len);
2860                param.crr_id = i;
2861
2862                sctp_addto_chunk(retval, paramlen, &param);
2863                sctp_addto_chunk(retval, addr_param_len, &addr_param);
2864        }
2865        return retval;
2866}
2867
2868/* ADDIP
2869 * 3.2.4 Set Primary IP Address
2870 *      0                   1                   2                   3
2871 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2872 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2873 *     |        Type =0xC004           |    Length = Variable          |
2874 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2875 *     |               ASCONF-Request Correlation ID                   |
2876 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2877 *     |                       Address Parameter                       |
2878 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2879 *
2880 * Create an ASCONF chunk with Set Primary IP address parameter.
2881 */
2882struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2883                                             union sctp_addr *addr)
2884{
2885        sctp_addip_param_t      param;
2886        struct sctp_chunk       *retval;
2887        int                     len = sizeof(param);
2888        union sctp_addr_param   addrparam;
2889        int                     addrlen;
2890        struct sctp_af          *af = sctp_get_af_specific(addr->v4.sin_family);
2891
2892        addrlen = af->to_addr_param(addr, &addrparam);
2893        if (!addrlen)
2894                return NULL;
2895        len += addrlen;
2896
2897        /* Create the chunk and make asconf header. */
2898        retval = sctp_make_asconf(asoc, addr, len);
2899        if (!retval)
2900                return NULL;
2901
2902        param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2903        param.param_hdr.length = htons(len);
2904        param.crr_id = 0;
2905
2906        sctp_addto_chunk(retval, sizeof(param), &param);
2907        sctp_addto_chunk(retval, addrlen, &addrparam);
2908
2909        return retval;
2910}
2911
2912/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2913 *      0                   1                   2                   3
2914 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2915 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2916 *     | Type = 0x80   |  Chunk Flags  |      Chunk Length             |
2917 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2918 *     |                       Serial Number                           |
2919 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2920 *     |                 ASCONF Parameter Response#1                   |
2921 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2922 *     \                                                               \
2923 *     /                             ....                              /
2924 *     \                                                               \
2925 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2926 *     |                 ASCONF Parameter Response#N                   |
2927 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2928 *
2929 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2930 */
2931static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2932                                               __u32 serial, int vparam_len)
2933{
2934        sctp_addiphdr_t         asconf;
2935        struct sctp_chunk       *retval;
2936        int                     length = sizeof(asconf) + vparam_len;
2937
2938        /* Create the chunk.  */
2939        retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2940        if (!retval)
2941                return NULL;
2942
2943        asconf.serial = htonl(serial);
2944
2945        retval->subh.addip_hdr =
2946                sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2947
2948        return retval;
2949}
2950
2951/* Add response parameters to an ASCONF_ACK chunk. */
2952static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2953                              __be16 err_code, sctp_addip_param_t *asconf_param)
2954{
2955        sctp_addip_param_t      ack_param;
2956        sctp_errhdr_t           err_param;
2957        int                     asconf_param_len = 0;
2958        int                     err_param_len = 0;
2959        __be16                  response_type;
2960
2961        if (SCTP_ERROR_NO_ERROR == err_code) {
2962                response_type = SCTP_PARAM_SUCCESS_REPORT;
2963        } else {
2964                response_type = SCTP_PARAM_ERR_CAUSE;
2965                err_param_len = sizeof(err_param);
2966                if (asconf_param)
2967                        asconf_param_len =
2968                                 ntohs(asconf_param->param_hdr.length);
2969        }
2970
2971        /* Add Success Indication or Error Cause Indication parameter. */
2972        ack_param.param_hdr.type = response_type;
2973        ack_param.param_hdr.length = htons(sizeof(ack_param) +
2974                                           err_param_len +
2975                                           asconf_param_len);
2976        ack_param.crr_id = crr_id;
2977        sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2978
2979        if (SCTP_ERROR_NO_ERROR == err_code)
2980                return;
2981
2982        /* Add Error Cause parameter. */
2983        err_param.cause = err_code;
2984        err_param.length = htons(err_param_len + asconf_param_len);
2985        sctp_addto_chunk(chunk, err_param_len, &err_param);
2986
2987        /* Add the failed TLV copied from ASCONF chunk. */
2988        if (asconf_param)
2989                sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
2990}
2991
2992/* Process a asconf parameter. */
2993static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
2994                                       struct sctp_chunk *asconf,
2995                                       sctp_addip_param_t *asconf_param)
2996{
2997        struct sctp_transport *peer;
2998        struct sctp_af *af;
2999        union sctp_addr addr;
3000        union sctp_addr_param *addr_param;
3001
3002        addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3003
3004        if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3005            asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3006            asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3007                return SCTP_ERROR_UNKNOWN_PARAM;
3008
3009        switch (addr_param->p.type) {
3010        case SCTP_PARAM_IPV6_ADDRESS:
3011                if (!asoc->peer.ipv6_address)
3012                        return SCTP_ERROR_DNS_FAILED;
3013                break;
3014        case SCTP_PARAM_IPV4_ADDRESS:
3015                if (!asoc->peer.ipv4_address)
3016                        return SCTP_ERROR_DNS_FAILED;
3017                break;
3018        default:
3019                return SCTP_ERROR_DNS_FAILED;
3020        }
3021
3022        af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3023        if (unlikely(!af))
3024                return SCTP_ERROR_DNS_FAILED;
3025
3026        af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3027
3028        /* ADDIP 4.2.1  This parameter MUST NOT contain a broadcast
3029         * or multicast address.
3030         * (note: wildcard is permitted and requires special handling so
3031         *  make sure we check for that)
3032         */
3033        if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3034                return SCTP_ERROR_DNS_FAILED;
3035
3036        switch (asconf_param->param_hdr.type) {
3037        case SCTP_PARAM_ADD_IP:
3038                /* Section 4.2.1:
3039                 * If the address 0.0.0.0 or ::0 is provided, the source
3040                 * address of the packet MUST be added.
3041                 */
3042                if (af->is_any(&addr))
3043                        memcpy(&addr, &asconf->source, sizeof(addr));
3044
3045                /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3046                 * request and does not have the local resources to add this
3047                 * new address to the association, it MUST return an Error
3048                 * Cause TLV set to the new error code 'Operation Refused
3049                 * Due to Resource Shortage'.
3050                 */
3051
3052                peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3053                if (!peer)
3054                        return SCTP_ERROR_RSRC_LOW;
3055
3056                /* Start the heartbeat timer. */
3057                if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
3058                        sctp_transport_hold(peer);
3059                asoc->new_transport = peer;
3060                break;
3061        case SCTP_PARAM_DEL_IP:
3062                /* ADDIP 4.3 D7) If a request is received to delete the
3063                 * last remaining IP address of a peer endpoint, the receiver
3064                 * MUST send an Error Cause TLV with the error cause set to the
3065                 * new error code 'Request to Delete Last Remaining IP Address'.
3066                 */
3067                if (asoc->peer.transport_count == 1)
3068                        return SCTP_ERROR_DEL_LAST_IP;
3069
3070                /* ADDIP 4.3 D8) If a request is received to delete an IP
3071                 * address which is also the source address of the IP packet
3072                 * which contained the ASCONF chunk, the receiver MUST reject
3073                 * this request. To reject the request the receiver MUST send
3074                 * an Error Cause TLV set to the new error code 'Request to
3075                 * Delete Source IP Address'
3076                 */
3077                if (sctp_cmp_addr_exact(&asconf->source, &addr))
3078                        return SCTP_ERROR_DEL_SRC_IP;
3079
3080                /* Section 4.2.2
3081                 * If the address 0.0.0.0 or ::0 is provided, all
3082                 * addresses of the peer except the source address of the
3083                 * packet MUST be deleted.
3084                 */
3085                if (af->is_any(&addr)) {
3086                        sctp_assoc_set_primary(asoc, asconf->transport);
3087                        sctp_assoc_del_nonprimary_peers(asoc,
3088                                                        asconf->transport);
3089                } else
3090                        sctp_assoc_del_peer(asoc, &addr);
3091                break;
3092        case SCTP_PARAM_SET_PRIMARY:
3093                /* ADDIP Section 4.2.4
3094                 * If the address 0.0.0.0 or ::0 is provided, the receiver
3095                 * MAY mark the source address of the packet as its
3096                 * primary.
3097                 */
3098                if (af->is_any(&addr))
3099                        memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3100
3101                peer = sctp_assoc_lookup_paddr(asoc, &addr);
3102                if (!peer)
3103                        return SCTP_ERROR_DNS_FAILED;
3104
3105                sctp_assoc_set_primary(asoc, peer);
3106                break;
3107        }
3108
3109        return SCTP_ERROR_NO_ERROR;
3110}
3111
3112/* Verify the ASCONF packet before we process it.  */
3113int sctp_verify_asconf(const struct sctp_association *asoc,
3114                       struct sctp_paramhdr *param_hdr, void *chunk_end,
3115                       struct sctp_paramhdr **errp) {
3116        sctp_addip_param_t *asconf_param;
3117        union sctp_params param;
3118        int length, plen;
3119
3120        param.v = (sctp_paramhdr_t *) param_hdr;
3121        while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
3122                length = ntohs(param.p->length);
3123                *errp = param.p;
3124
3125                if (param.v > chunk_end - length ||
3126                    length < sizeof(sctp_paramhdr_t))
3127                        return 0;
3128
3129                switch (param.p->type) {
3130                case SCTP_PARAM_ADD_IP:
3131                case SCTP_PARAM_DEL_IP:
3132                case SCTP_PARAM_SET_PRIMARY:
3133                        asconf_param = (sctp_addip_param_t *)param.v;
3134                        plen = ntohs(asconf_param->param_hdr.length);
3135                        if (plen < sizeof(sctp_addip_param_t) +
3136                            sizeof(sctp_paramhdr_t))
3137                                return 0;
3138                        break;
3139                case SCTP_PARAM_SUCCESS_REPORT:
3140                case SCTP_PARAM_ADAPTATION_LAYER_IND:
3141                        if (length != sizeof(sctp_addip_param_t))
3142                                return 0;
3143
3144                        break;
3145                default:
3146                        break;
3147                }
3148
3149                param.v += WORD_ROUND(length);
3150        }
3151
3152        if (param.v != chunk_end)
3153                return 0;
3154
3155        return 1;
3156}
3157
3158/* Process an incoming ASCONF chunk with the next expected serial no. and
3159 * return an ASCONF_ACK chunk to be sent in response.
3160 */
3161struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3162                                       struct sctp_chunk *asconf)
3163{
3164        sctp_addiphdr_t         *hdr;
3165        union sctp_addr_param   *addr_param;
3166        sctp_addip_param_t      *asconf_param;
3167        struct sctp_chunk       *asconf_ack;
3168
3169        __be16  err_code;
3170        int     length = 0;
3171        int     chunk_len;
3172        __u32   serial;
3173        int     all_param_pass = 1;
3174
3175        chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3176        hdr = (sctp_addiphdr_t *)asconf->skb->data;
3177        serial = ntohl(hdr->serial);
3178
3179        /* Skip the addiphdr and store a pointer to address parameter.  */
3180        length = sizeof(sctp_addiphdr_t);
3181        addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3182        chunk_len -= length;
3183
3184        /* Skip the address parameter and store a pointer to the first
3185         * asconf parameter.
3186         */
3187        length = ntohs(addr_param->p.length);
3188        asconf_param = (void *)addr_param + length;
3189        chunk_len -= length;
3190
3191        /* create an ASCONF_ACK chunk.
3192         * Based on the definitions of parameters, we know that the size of
3193         * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3194         * parameters.
3195         */
3196        asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3197        if (!asconf_ack)
3198                goto done;
3199
3200        /* Process the TLVs contained within the ASCONF chunk. */
3201        while (chunk_len > 0) {
3202                err_code = sctp_process_asconf_param(asoc, asconf,
3203                                                     asconf_param);
3204                /* ADDIP 4.1 A7)
3205                 * If an error response is received for a TLV parameter,
3206                 * all TLVs with no response before the failed TLV are
3207                 * considered successful if not reported.  All TLVs after
3208                 * the failed response are considered unsuccessful unless
3209                 * a specific success indication is present for the parameter.
3210                 */
3211                if (SCTP_ERROR_NO_ERROR != err_code)
3212                        all_param_pass = 0;
3213
3214                if (!all_param_pass)
3215                        sctp_add_asconf_response(asconf_ack,
3216                                                 asconf_param->crr_id, err_code,
3217                                                 asconf_param);
3218
3219                /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3220                 * an IP address sends an 'Out of Resource' in its response, it
3221                 * MUST also fail any subsequent add or delete requests bundled
3222                 * in the ASCONF.
3223                 */
3224                if (SCTP_ERROR_RSRC_LOW == err_code)
3225                        goto done;
3226
3227                /* Move to the next ASCONF param. */
3228                length = ntohs(asconf_param->param_hdr.length);
3229                asconf_param = (void *)asconf_param + length;
3230                chunk_len -= length;
3231        }
3232
3233done:
3234        asoc->peer.addip_serial++;
3235
3236        /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3237         * after freeing the reference to old asconf ack if any.
3238         */
3239        if (asconf_ack) {
3240                sctp_chunk_hold(asconf_ack);
3241                list_add_tail(&asconf_ack->transmitted_list,
3242                              &asoc->asconf_ack_list);
3243        }
3244
3245        return asconf_ack;
3246}
3247
3248/* Process a asconf parameter that is successfully acked. */
3249static void sctp_asconf_param_success(struct sctp_association *asoc,
3250                                     sctp_addip_param_t *asconf_param)
3251{
3252        struct sctp_af *af;
3253        union sctp_addr addr;
3254        struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3255        union sctp_addr_param *addr_param;
3256        struct sctp_transport *transport;
3257        struct sctp_sockaddr_entry *saddr;
3258
3259        addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3260
3261        /* We have checked the packet before, so we do not check again. */
3262        af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3263        af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3264
3265        switch (asconf_param->param_hdr.type) {
3266        case SCTP_PARAM_ADD_IP:
3267                /* This is always done in BH context with a socket lock
3268                 * held, so the list can not change.
3269                 */
3270                local_bh_disable();
3271                list_for_each_entry(saddr, &bp->address_list, list) {
3272                        if (sctp_cmp_addr_exact(&saddr->a, &addr))
3273                                saddr->state = SCTP_ADDR_SRC;
3274                }
3275                local_bh_enable();
3276                list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3277                                transports) {
3278                        dst_release(transport->dst);
3279                        transport->dst = NULL;
3280                }
3281                break;
3282        case SCTP_PARAM_DEL_IP:
3283                local_bh_disable();
3284                sctp_del_bind_addr(bp, &addr);
3285                if (asoc->asconf_addr_del_pending != NULL &&
3286                    sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3287                        kfree(asoc->asconf_addr_del_pending);
3288                        asoc->asconf_addr_del_pending = NULL;
3289                }
3290                local_bh_enable();
3291                list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3292                                transports) {
3293                        dst_release(transport->dst);
3294                        transport->dst = NULL;
3295                }
3296                break;
3297        default:
3298                break;
3299        }
3300}
3301
3302/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3303 * for the given asconf parameter.  If there is no response for this parameter,
3304 * return the error code based on the third argument 'no_err'.
3305 * ADDIP 4.1
3306 * A7) If an error response is received for a TLV parameter, all TLVs with no
3307 * response before the failed TLV are considered successful if not reported.
3308 * All TLVs after the failed response are considered unsuccessful unless a
3309 * specific success indication is present for the parameter.
3310 */
3311static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3312                                      sctp_addip_param_t *asconf_param,
3313                                      int no_err)
3314{
3315        sctp_addip_param_t      *asconf_ack_param;
3316        sctp_errhdr_t           *err_param;
3317        int                     length;
3318        int                     asconf_ack_len;
3319        __be16                  err_code;
3320
3321        if (no_err)
3322                err_code = SCTP_ERROR_NO_ERROR;
3323        else
3324                err_code = SCTP_ERROR_REQ_REFUSED;
3325
3326        asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3327                             sizeof(sctp_chunkhdr_t);
3328
3329        /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3330         * the first asconf_ack parameter.
3331         */
3332        length = sizeof(sctp_addiphdr_t);
3333        asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3334                                                  length);
3335        asconf_ack_len -= length;
3336
3337        while (asconf_ack_len > 0) {
3338                if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3339                        switch(asconf_ack_param->param_hdr.type) {
3340                        case SCTP_PARAM_SUCCESS_REPORT:
3341                                return SCTP_ERROR_NO_ERROR;
3342                        case SCTP_PARAM_ERR_CAUSE:
3343                                length = sizeof(sctp_addip_param_t);
3344                                err_param = (void *)asconf_ack_param + length;
3345                                asconf_ack_len -= length;
3346                                if (asconf_ack_len > 0)
3347                                        return err_param->cause;
3348                                else
3349                                        return SCTP_ERROR_INV_PARAM;
3350                                break;
3351                        default:
3352                                return SCTP_ERROR_INV_PARAM;
3353                        }
3354                }
3355
3356                length = ntohs(asconf_ack_param->param_hdr.length);
3357                asconf_ack_param = (void *)asconf_ack_param + length;
3358                asconf_ack_len -= length;
3359        }
3360
3361        return err_code;
3362}
3363
3364/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3365int sctp_process_asconf_ack(struct sctp_association *asoc,
3366                            struct sctp_chunk *asconf_ack)
3367{
3368        struct sctp_chunk       *asconf = asoc->addip_last_asconf;
3369        union sctp_addr_param   *addr_param;
3370        sctp_addip_param_t      *asconf_param;
3371        int     length = 0;
3372        int     asconf_len = asconf->skb->len;
3373        int     all_param_pass = 0;
3374        int     no_err = 1;
3375        int     retval = 0;
3376        __be16  err_code = SCTP_ERROR_NO_ERROR;
3377
3378        /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3379         * a pointer to address parameter.
3380         */
3381        length = sizeof(sctp_addip_chunk_t);
3382        addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3383        asconf_len -= length;
3384
3385        /* Skip the address parameter in the last asconf sent and store a
3386         * pointer to the first asconf parameter.
3387         */
3388        length = ntohs(addr_param->p.length);
3389        asconf_param = (void *)addr_param + length;
3390        asconf_len -= length;
3391
3392        /* ADDIP 4.1
3393         * A8) If there is no response(s) to specific TLV parameter(s), and no
3394         * failures are indicated, then all request(s) are considered
3395         * successful.
3396         */
3397        if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3398                all_param_pass = 1;
3399
3400        /* Process the TLVs contained in the last sent ASCONF chunk. */
3401        while (asconf_len > 0) {
3402                if (all_param_pass)
3403                        err_code = SCTP_ERROR_NO_ERROR;
3404                else {
3405                        err_code = sctp_get_asconf_response(asconf_ack,
3406                                                            asconf_param,
3407                                                            no_err);
3408                        if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3409                                no_err = 0;
3410                }
3411
3412                switch (err_code) {
3413                case SCTP_ERROR_NO_ERROR:
3414                        sctp_asconf_param_success(asoc, asconf_param);
3415                        break;
3416
3417                case SCTP_ERROR_RSRC_LOW:
3418                        retval = 1;
3419                        break;
3420
3421                case SCTP_ERROR_UNKNOWN_PARAM:
3422                        /* Disable sending this type of asconf parameter in
3423                         * future.
3424                         */
3425                        asoc->peer.addip_disabled_mask |=
3426                                asconf_param->param_hdr.type;
3427                        break;
3428
3429                case SCTP_ERROR_REQ_REFUSED:
3430                case SCTP_ERROR_DEL_LAST_IP:
3431                case SCTP_ERROR_DEL_SRC_IP:
3432                default:
3433                         break;
3434                }
3435
3436                /* Skip the processed asconf parameter and move to the next
3437                 * one.
3438                 */
3439                length = ntohs(asconf_param->param_hdr.length);
3440                asconf_param = (void *)asconf_param + length;
3441                asconf_len -= length;
3442        }
3443
3444        if (no_err && asoc->src_out_of_asoc_ok) {
3445                asoc->src_out_of_asoc_ok = 0;
3446                sctp_transport_immediate_rtx(asoc->peer.primary_path);
3447        }
3448
3449        /* Free the cached last sent asconf chunk. */
3450        list_del_init(&asconf->transmitted_list);
3451        sctp_chunk_free(asconf);
3452        asoc->addip_last_asconf = NULL;
3453
3454        return retval;
3455}
3456
3457/* Make a FWD TSN chunk. */
3458struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3459                                    __u32 new_cum_tsn, size_t nstreams,
3460                                    struct sctp_fwdtsn_skip *skiplist)
3461{
3462        struct sctp_chunk *retval = NULL;
3463        struct sctp_fwdtsn_hdr ftsn_hdr;
3464        struct sctp_fwdtsn_skip skip;
3465        size_t hint;
3466        int i;
3467
3468        hint = (nstreams + 1) * sizeof(__u32);
3469
3470        retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint);
3471
3472        if (!retval)
3473                return NULL;
3474
3475        ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3476        retval->subh.fwdtsn_hdr =
3477                sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3478
3479        for (i = 0; i < nstreams; i++) {
3480                skip.stream = skiplist[i].stream;
3481                skip.ssn = skiplist[i].ssn;
3482                sctp_addto_chunk(retval, sizeof(skip), &skip);
3483        }
3484
3485        return retval;
3486}
3487
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