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