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