net/sctp/sm_make

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This source file includes following definitions.
sctp_control_release_owner
sctp_control_set_owner_w
sctp_chunk_iif
sctp_init_cause
sctp_make_init
sctp_make_init_ack
sctp_make_cookie_echo
sctp_make_cookie_ack
sctp_make_cwr
sctp_make_ecne
sctp_make_datafrag_empty
sctp_make_sack
sctp_make_shutdown
sctp_make_shutdown_ack
sctp_make_shutdown_complete
sctp_make_abort
sctp_make_abort_no_data
sctp_make_abort_user
sctp_addto_param
sctp_make_abort_violation
sctp_make_violation_paramlen
sctp_make_violation_max_retrans
sctp_make_heartbeat
sctp_make_heartbeat_ack
sctp_make_op_error_space
sctp_make_op_error_limited
sctp_make_op_error
sctp_make_auth
sctp_chunkify
sctp_init_addrs
sctp_source
_sctp_make_chunk
sctp_make_data
sctp_make_idata
sctp_make_control
sctp_chunk_destroy
sctp_chunk_free
sctp_chunk_hold
sctp_chunk_put
sctp_addto_chunk
sctp_user_addto_chunk
sctp_chunk_assign_ssn
sctp_chunk_assign_tsn
sctp_make_temp_asoc
sctp_pack_cookie
sctp_unpack_cookie
sctp_process_missing_param
sctp_process_inv_mandatory
sctp_process_inv_paramlength
sctp_process_hn_param
sctp_verify_ext_param
sctp_process_ext_param
sctp_process_unk_param
sctp_verify_param
sctp_verify_init
sctp_process_init
sctp_process_param
sctp_generate_tag
sctp_generate_tsn
sctp_make_asconf
sctp_make_asconf_update_ip
sctp_make_asconf_set_prim
sctp_make_asconf_ack
sctp_add_asconf_response
sctp_process_asconf_param
sctp_verify_asconf
sctp_process_asconf
sctp_asconf_param_success
sctp_get_asconf_response
sctp_process_asconf_ack
sctp_make_fwdtsn
sctp_make_ifwdtsn
sctp_make_reconf
sctp_make_strreset_req
sctp_make_strreset_tsnreq
sctp_make_strreset_addstrm
sctp_make_strreset_resp
sctp_make_strreset_tsnresp
sctp_verify_reconf
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* SCTP kernel implementation
   3  * (C) Copyright IBM Corp. 2001, 2004
   4  * Copyright (c) 1999-2000 Cisco, Inc.
   5  * Copyright (c) 1999-2001 Motorola, Inc.
   6  * Copyright (c) 2001-2002 Intel Corp.
   7  *
   8  * This file is part of the SCTP kernel implementation
   9  *
  10  * These functions work with the state functions in sctp_sm_statefuns.c
  11  * to implement the state operations.  These functions implement the
  12  * steps which require modifying existing data structures.
  13  *
  14  * Please send any bug reports or fixes you make to the
  15  * email address(es):
  16  *    lksctp developers <linux-sctp@vger.kernel.org>
  17  *
  18  * Written or modified by:
  19  *    La Monte H.P. Yarroll <piggy@acm.org>
  20  *    Karl Knutson          <karl@athena.chicago.il.us>
  21  *    C. Robin              <chris@hundredacre.ac.uk>
  22  *    Jon Grimm             <jgrimm@us.ibm.com>
  23  *    Xingang Guo           <xingang.guo@intel.com>
  24  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  25  *    Sridhar Samudrala     <sri@us.ibm.com>
  26  *    Daisy Chang           <daisyc@us.ibm.com>
  27  *    Ardelle Fan           <ardelle.fan@intel.com>
  28  *    Kevin Gao             <kevin.gao@intel.com>
  29  */
  30 
  31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  32 
  33 #include <crypto/hash.h>
  34 #include <linux/types.h>
  35 #include <linux/kernel.h>
  36 #include <linux/ip.h>
  37 #include <linux/ipv6.h>
  38 #include <linux/net.h>
  39 #include <linux/inet.h>
  40 #include <linux/scatterlist.h>
  41 #include <linux/slab.h>
  42 #include <net/sock.h>
  43 
  44 #include <linux/skbuff.h>
  45 #include <linux/random.h>       /* for get_random_bytes */
  46 #include <net/sctp/sctp.h>
  47 #include <net/sctp/sm.h>
  48 
  49 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
  50                                             __u8 type, __u8 flags, int paylen,
  51                                             gfp_t gfp);
  52 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
  53                                          __u8 flags, int paylen, gfp_t gfp);
  54 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
  55                                            __u8 type, __u8 flags, int paylen,
  56                                            gfp_t gfp);
  57 static struct sctp_cookie_param *sctp_pack_cookie(
  58                                         const struct sctp_endpoint *ep,
  59                                         const struct sctp_association *asoc,
  60                                         const struct sctp_chunk *init_chunk,
  61                                         int *cookie_len,
  62                                         const __u8 *raw_addrs, int addrs_len);
  63 static int sctp_process_param(struct sctp_association *asoc,
  64                               union sctp_params param,
  65                               const union sctp_addr *peer_addr,
  66                               gfp_t gfp);
  67 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
  68                               const void *data);
  69 
  70 /* Control chunk destructor */
  71 static void sctp_control_release_owner(struct sk_buff *skb)
  72 {
  73         struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
  74 
  75         if (chunk->shkey) {
  76                 struct sctp_shared_key *shkey = chunk->shkey;
  77                 struct sctp_association *asoc = chunk->asoc;
  78 
  79                 /* refcnt == 2 and !list_empty mean after this release, it's
  80                  * not being used anywhere, and it's time to notify userland
  81                  * that this shkey can be freed if it's been deactivated.
  82                  */
  83                 if (shkey->deactivated && !list_empty(&shkey->key_list) &&
  84                     refcount_read(&shkey->refcnt) == 2) {
  85                         struct sctp_ulpevent *ev;
  86 
  87                         ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
  88                                                         SCTP_AUTH_FREE_KEY,
  89                                                         GFP_KERNEL);
  90                         if (ev)
  91                                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
  92                 }
  93                 sctp_auth_shkey_release(chunk->shkey);
  94         }
  95 }
  96 
  97 static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
  98 {
  99         struct sctp_association *asoc = chunk->asoc;
 100         struct sk_buff *skb = chunk->skb;
 101 
 102         /* TODO: properly account for control chunks.
 103          * To do it right we'll need:
 104          *  1) endpoint if association isn't known.
 105          *  2) proper memory accounting.
 106          *
 107          *  For now don't do anything for now.
 108          */
 109         if (chunk->auth) {
 110                 chunk->shkey = asoc->shkey;
 111                 sctp_auth_shkey_hold(chunk->shkey);
 112         }
 113         skb->sk = asoc ? asoc->base.sk : NULL;
 114         skb_shinfo(skb)->destructor_arg = chunk;
 115         skb->destructor = sctp_control_release_owner;
 116 }
 117 
 118 /* What was the inbound interface for this chunk? */
 119 int sctp_chunk_iif(const struct sctp_chunk *chunk)
 120 {
 121         struct sk_buff *skb = chunk->skb;
 122 
 123         return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
 124 }
 125 
 126 /* RFC 2960 3.3.2 Initiation (INIT) (1)
 127  *
 128  * Note 2: The ECN capable field is reserved for future use of
 129  * Explicit Congestion Notification.
 130  */
 131 static const struct sctp_paramhdr ecap_param = {
 132         SCTP_PARAM_ECN_CAPABLE,
 133         cpu_to_be16(sizeof(struct sctp_paramhdr)),
 134 };
 135 static const struct sctp_paramhdr prsctp_param = {
 136         SCTP_PARAM_FWD_TSN_SUPPORT,
 137         cpu_to_be16(sizeof(struct sctp_paramhdr)),
 138 };
 139 
 140 /* A helper to initialize an op error inside a provided chunk, as most
 141  * cause codes will be embedded inside an abort chunk.
 142  */
 143 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
 144                     size_t paylen)
 145 {
 146         struct sctp_errhdr err;
 147         __u16 len;
 148 
 149         /* Cause code constants are now defined in network order.  */
 150         err.cause = cause_code;
 151         len = sizeof(err) + paylen;
 152         err.length = htons(len);
 153 
 154         if (skb_tailroom(chunk->skb) < len)
 155                 return -ENOSPC;
 156 
 157         chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
 158 
 159         return 0;
 160 }
 161 
 162 /* 3.3.2 Initiation (INIT) (1)
 163  *
 164  * This chunk is used to initiate a SCTP association between two
 165  * endpoints. The format of the INIT chunk is shown below:
 166  *
 167  *     0                   1                   2                   3
 168  *     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
 169  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 170  *    |   Type = 1    |  Chunk Flags  |      Chunk Length             |
 171  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 172  *    |                         Initiate Tag                          |
 173  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 174  *    |           Advertised Receiver Window Credit (a_rwnd)          |
 175  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 176  *    |  Number of Outbound Streams   |  Number of Inbound Streams    |
 177  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 178  *    |                          Initial TSN                          |
 179  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 180  *    \                                                               \
 181  *    /              Optional/Variable-Length Parameters              /
 182  *    \                                                               \
 183  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 184  *
 185  *
 186  * The INIT chunk contains the following parameters. Unless otherwise
 187  * noted, each parameter MUST only be included once in the INIT chunk.
 188  *
 189  * Fixed Parameters                     Status
 190  * ----------------------------------------------
 191  * Initiate Tag                        Mandatory
 192  * Advertised Receiver Window Credit   Mandatory
 193  * Number of Outbound Streams          Mandatory
 194  * Number of Inbound Streams           Mandatory
 195  * Initial TSN                         Mandatory
 196  *
 197  * Variable Parameters                  Status     Type Value
 198  * -------------------------------------------------------------
 199  * IPv4 Address (Note 1)               Optional    5
 200  * IPv6 Address (Note 1)               Optional    6
 201  * Cookie Preservative                 Optional    9
 202  * Reserved for ECN Capable (Note 2)   Optional    32768 (0x8000)
 203  * Host Name Address (Note 3)          Optional    11
 204  * Supported Address Types (Note 4)    Optional    12
 205  */
 206 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
 207                                   const struct sctp_bind_addr *bp,
 208                                   gfp_t gfp, int vparam_len)
 209 {
 210         struct sctp_supported_ext_param ext_param;
 211         struct sctp_adaptation_ind_param aiparam;
 212         struct sctp_paramhdr *auth_chunks = NULL;
 213         struct sctp_paramhdr *auth_hmacs = NULL;
 214         struct sctp_supported_addrs_param sat;
 215         struct sctp_endpoint *ep = asoc->ep;
 216         struct sctp_chunk *retval = NULL;
 217         int num_types, addrs_len = 0;
 218         struct sctp_inithdr init;
 219         union sctp_params addrs;
 220         struct sctp_sock *sp;
 221         __u8 extensions[5];
 222         size_t chunksize;
 223         __be16 types[2];
 224         int num_ext = 0;
 225 
 226         /* RFC 2960 3.3.2 Initiation (INIT) (1)
 227          *
 228          * Note 1: The INIT chunks can contain multiple addresses that
 229          * can be IPv4 and/or IPv6 in any combination.
 230          */
 231 
 232         /* Convert the provided bind address list to raw format. */
 233         addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
 234 
 235         init.init_tag              = htonl(asoc->c.my_vtag);
 236         init.a_rwnd                = htonl(asoc->rwnd);
 237         init.num_outbound_streams  = htons(asoc->c.sinit_num_ostreams);
 238         init.num_inbound_streams   = htons(asoc->c.sinit_max_instreams);
 239         init.initial_tsn           = htonl(asoc->c.initial_tsn);
 240 
 241         /* How many address types are needed? */
 242         sp = sctp_sk(asoc->base.sk);
 243         num_types = sp->pf->supported_addrs(sp, types);
 244 
 245         chunksize = sizeof(init) + addrs_len;
 246         chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
 247 
 248         if (asoc->ep->ecn_enable)
 249                 chunksize += sizeof(ecap_param);
 250 
 251         if (asoc->ep->prsctp_enable)
 252                 chunksize += sizeof(prsctp_param);
 253 
 254         /* ADDIP: Section 4.2.7:
 255          *  An implementation supporting this extension [ADDIP] MUST list
 256          *  the ASCONF,the ASCONF-ACK, and the AUTH  chunks in its INIT and
 257          *  INIT-ACK parameters.
 258          */
 259         if (asoc->ep->asconf_enable) {
 260                 extensions[num_ext] = SCTP_CID_ASCONF;
 261                 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
 262                 num_ext += 2;
 263         }
 264 
 265         if (asoc->ep->reconf_enable) {
 266                 extensions[num_ext] = SCTP_CID_RECONF;
 267                 num_ext += 1;
 268         }
 269 
 270         if (sp->adaptation_ind)
 271                 chunksize += sizeof(aiparam);
 272 
 273         if (asoc->ep->intl_enable) {
 274                 extensions[num_ext] = SCTP_CID_I_DATA;
 275                 num_ext += 1;
 276         }
 277 
 278         chunksize += vparam_len;
 279 
 280         /* Account for AUTH related parameters */
 281         if (ep->auth_enable) {
 282                 /* Add random parameter length*/
 283                 chunksize += sizeof(asoc->c.auth_random);
 284 
 285                 /* Add HMACS parameter length if any were defined */
 286                 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
 287                 if (auth_hmacs->length)
 288                         chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
 289                 else
 290                         auth_hmacs = NULL;
 291 
 292                 /* Add CHUNKS parameter length */
 293                 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
 294                 if (auth_chunks->length)
 295                         chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
 296                 else
 297                         auth_chunks = NULL;
 298 
 299                 extensions[num_ext] = SCTP_CID_AUTH;
 300                 num_ext += 1;
 301         }
 302 
 303         /* If we have any extensions to report, account for that */
 304         if (num_ext)
 305                 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
 306 
 307         /* RFC 2960 3.3.2 Initiation (INIT) (1)
 308          *
 309          * Note 3: An INIT chunk MUST NOT contain more than one Host
 310          * Name address parameter. Moreover, the sender of the INIT
 311          * MUST NOT combine any other address types with the Host Name
 312          * address in the INIT. The receiver of INIT MUST ignore any
 313          * other address types if the Host Name address parameter is
 314          * present in the received INIT chunk.
 315          *
 316          * PLEASE DO NOT FIXME [This version does not support Host Name.]
 317          */
 318 
 319         retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
 320         if (!retval)
 321                 goto nodata;
 322 
 323         retval->subh.init_hdr =
 324                 sctp_addto_chunk(retval, sizeof(init), &init);
 325         retval->param_hdr.v =
 326                 sctp_addto_chunk(retval, addrs_len, addrs.v);
 327 
 328         /* RFC 2960 3.3.2 Initiation (INIT) (1)
 329          *
 330          * Note 4: This parameter, when present, specifies all the
 331          * address types the sending endpoint can support. The absence
 332          * of this parameter indicates that the sending endpoint can
 333          * support any address type.
 334          */
 335         sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
 336         sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
 337         sctp_addto_chunk(retval, sizeof(sat), &sat);
 338         sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
 339 
 340         if (asoc->ep->ecn_enable)
 341                 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
 342 
 343         /* Add the supported extensions parameter.  Be nice and add this
 344          * fist before addiding the parameters for the extensions themselves
 345          */
 346         if (num_ext) {
 347                 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
 348                 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
 349                 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
 350                 sctp_addto_param(retval, num_ext, extensions);
 351         }
 352 
 353         if (asoc->ep->prsctp_enable)
 354                 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
 355 
 356         if (sp->adaptation_ind) {
 357                 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
 358                 aiparam.param_hdr.length = htons(sizeof(aiparam));
 359                 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
 360                 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
 361         }
 362 
 363         /* Add SCTP-AUTH chunks to the parameter list */
 364         if (ep->auth_enable) {
 365                 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
 366                                  asoc->c.auth_random);
 367                 if (auth_hmacs)
 368                         sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
 369                                         auth_hmacs);
 370                 if (auth_chunks)
 371                         sctp_addto_chunk(retval, ntohs(auth_chunks->length),
 372                                         auth_chunks);
 373         }
 374 nodata:
 375         kfree(addrs.v);
 376         return retval;
 377 }
 378 
 379 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
 380                                       const struct sctp_chunk *chunk,
 381                                       gfp_t gfp, int unkparam_len)
 382 {
 383         struct sctp_supported_ext_param ext_param;
 384         struct sctp_adaptation_ind_param aiparam;
 385         struct sctp_paramhdr *auth_chunks = NULL;
 386         struct sctp_paramhdr *auth_random = NULL;
 387         struct sctp_paramhdr *auth_hmacs = NULL;
 388         struct sctp_chunk *retval = NULL;
 389         struct sctp_cookie_param *cookie;
 390         struct sctp_inithdr initack;
 391         union sctp_params addrs;
 392         struct sctp_sock *sp;
 393         __u8 extensions[5];
 394         size_t chunksize;
 395         int num_ext = 0;
 396         int cookie_len;
 397         int addrs_len;
 398 
 399         /* Note: there may be no addresses to embed. */
 400         addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
 401 
 402         initack.init_tag                = htonl(asoc->c.my_vtag);
 403         initack.a_rwnd                  = htonl(asoc->rwnd);
 404         initack.num_outbound_streams    = htons(asoc->c.sinit_num_ostreams);
 405         initack.num_inbound_streams     = htons(asoc->c.sinit_max_instreams);
 406         initack.initial_tsn             = htonl(asoc->c.initial_tsn);
 407 
 408         /* FIXME:  We really ought to build the cookie right
 409          * into the packet instead of allocating more fresh memory.
 410          */
 411         cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
 412                                   addrs.v, addrs_len);
 413         if (!cookie)
 414                 goto nomem_cookie;
 415 
 416         /* Calculate the total size of allocation, include the reserved
 417          * space for reporting unknown parameters if it is specified.
 418          */
 419         sp = sctp_sk(asoc->base.sk);
 420         chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
 421 
 422         /* Tell peer that we'll do ECN only if peer advertised such cap.  */
 423         if (asoc->peer.ecn_capable)
 424                 chunksize += sizeof(ecap_param);
 425 
 426         if (asoc->peer.prsctp_capable)
 427                 chunksize += sizeof(prsctp_param);
 428 
 429         if (asoc->peer.asconf_capable) {
 430                 extensions[num_ext] = SCTP_CID_ASCONF;
 431                 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
 432                 num_ext += 2;
 433         }
 434 
 435         if (asoc->peer.reconf_capable) {
 436                 extensions[num_ext] = SCTP_CID_RECONF;
 437                 num_ext += 1;
 438         }
 439 
 440         if (sp->adaptation_ind)
 441                 chunksize += sizeof(aiparam);
 442 
 443         if (asoc->peer.intl_capable) {
 444                 extensions[num_ext] = SCTP_CID_I_DATA;
 445                 num_ext += 1;
 446         }
 447 
 448         if (asoc->peer.auth_capable) {
 449                 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
 450                 chunksize += ntohs(auth_random->length);
 451 
 452                 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
 453                 if (auth_hmacs->length)
 454                         chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
 455                 else
 456                         auth_hmacs = NULL;
 457 
 458                 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
 459                 if (auth_chunks->length)
 460                         chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
 461                 else
 462                         auth_chunks = NULL;
 463 
 464                 extensions[num_ext] = SCTP_CID_AUTH;
 465                 num_ext += 1;
 466         }
 467 
 468         if (num_ext)
 469                 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
 470 
 471         /* Now allocate and fill out the chunk.  */
 472         retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
 473         if (!retval)
 474                 goto nomem_chunk;
 475 
 476         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 477          *
 478          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 479          * HEARTBEAT ACK, * etc.) to the same destination transport
 480          * address from which it received the DATA or control chunk
 481          * to which it is replying.
 482          *
 483          * [INIT ACK back to where the INIT came from.]
 484          */
 485         if (chunk->transport)
 486                 retval->transport =
 487                         sctp_assoc_lookup_paddr(asoc,
 488                                                 &chunk->transport->ipaddr);
 489 
 490         retval->subh.init_hdr =
 491                 sctp_addto_chunk(retval, sizeof(initack), &initack);
 492         retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
 493         sctp_addto_chunk(retval, cookie_len, cookie);
 494         if (asoc->peer.ecn_capable)
 495                 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
 496         if (num_ext) {
 497                 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
 498                 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
 499                 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
 500                 sctp_addto_param(retval, num_ext, extensions);
 501         }
 502         if (asoc->peer.prsctp_capable)
 503                 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
 504 
 505         if (sp->adaptation_ind) {
 506                 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
 507                 aiparam.param_hdr.length = htons(sizeof(aiparam));
 508                 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
 509                 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
 510         }
 511 
 512         if (asoc->peer.auth_capable) {
 513                 sctp_addto_chunk(retval, ntohs(auth_random->length),
 514                                  auth_random);
 515                 if (auth_hmacs)
 516                         sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
 517                                         auth_hmacs);
 518                 if (auth_chunks)
 519                         sctp_addto_chunk(retval, ntohs(auth_chunks->length),
 520                                         auth_chunks);
 521         }
 522 
 523         /* We need to remove the const qualifier at this point.  */
 524         retval->asoc = (struct sctp_association *) asoc;
 525 
 526 nomem_chunk:
 527         kfree(cookie);
 528 nomem_cookie:
 529         kfree(addrs.v);
 530         return retval;
 531 }
 532 
 533 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
 534  *
 535  * This chunk is used only during the initialization of an association.
 536  * It is sent by the initiator of an association to its peer to complete
 537  * the initialization process. This chunk MUST precede any DATA chunk
 538  * sent within the association, but MAY be bundled with one or more DATA
 539  * chunks in the same packet.
 540  *
 541  *      0                   1                   2                   3
 542  *      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
 543  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 544  *     |   Type = 10   |Chunk  Flags   |         Length                |
 545  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 546  *     /                     Cookie                                    /
 547  *     \                                                               \
 548  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 549  *
 550  * Chunk Flags: 8 bit
 551  *
 552  *   Set to zero on transmit and ignored on receipt.
 553  *
 554  * Length: 16 bits (unsigned integer)
 555  *
 556  *   Set to the size of the chunk in bytes, including the 4 bytes of
 557  *   the chunk header and the size of the Cookie.
 558  *
 559  * Cookie: variable size
 560  *
 561  *   This field must contain the exact cookie received in the
 562  *   State Cookie parameter from the previous INIT ACK.
 563  *
 564  *   An implementation SHOULD make the cookie as small as possible
 565  *   to insure interoperability.
 566  */
 567 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
 568                                          const struct sctp_chunk *chunk)
 569 {
 570         struct sctp_chunk *retval;
 571         int cookie_len;
 572         void *cookie;
 573 
 574         cookie = asoc->peer.cookie;
 575         cookie_len = asoc->peer.cookie_len;
 576 
 577         /* Build a cookie echo chunk.  */
 578         retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
 579                                    cookie_len, GFP_ATOMIC);
 580         if (!retval)
 581                 goto nodata;
 582         retval->subh.cookie_hdr =
 583                 sctp_addto_chunk(retval, cookie_len, cookie);
 584 
 585         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 586          *
 587          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 588          * HEARTBEAT ACK, * etc.) to the same destination transport
 589          * address from which it * received the DATA or control chunk
 590          * to which it is replying.
 591          *
 592          * [COOKIE ECHO back to where the INIT ACK came from.]
 593          */
 594         if (chunk)
 595                 retval->transport = chunk->transport;
 596 
 597 nodata:
 598         return retval;
 599 }
 600 
 601 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
 602  *
 603  * This chunk is used only during the initialization of an
 604  * association.  It is used to acknowledge the receipt of a COOKIE
 605  * ECHO chunk.  This chunk MUST precede any DATA or SACK chunk sent
 606  * within the association, but MAY be bundled with one or more DATA
 607  * chunks or SACK chunk in the same SCTP packet.
 608  *
 609  *      0                   1                   2                   3
 610  *      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
 611  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 612  *     |   Type = 11   |Chunk  Flags   |     Length = 4                |
 613  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 614  *
 615  * Chunk Flags: 8 bits
 616  *
 617  *   Set to zero on transmit and ignored on receipt.
 618  */
 619 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
 620                                         const struct sctp_chunk *chunk)
 621 {
 622         struct sctp_chunk *retval;
 623 
 624         retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
 625 
 626         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 627          *
 628          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 629          * HEARTBEAT ACK, * etc.) to the same destination transport
 630          * address from which it * received the DATA or control chunk
 631          * to which it is replying.
 632          *
 633          * [COOKIE ACK back to where the COOKIE ECHO came from.]
 634          */
 635         if (retval && chunk && chunk->transport)
 636                 retval->transport =
 637                         sctp_assoc_lookup_paddr(asoc,
 638                                                 &chunk->transport->ipaddr);
 639 
 640         return retval;
 641 }
 642 
 643 /*
 644  *  Appendix A: Explicit Congestion Notification:
 645  *  CWR:
 646  *
 647  *  RFC 2481 details a specific bit for a sender to send in the header of
 648  *  its next outbound TCP segment to indicate to its peer that it has
 649  *  reduced its congestion window.  This is termed the CWR bit.  For
 650  *  SCTP the same indication is made by including the CWR chunk.
 651  *  This chunk contains one data element, i.e. the TSN number that
 652  *  was sent in the ECNE chunk.  This element represents the lowest
 653  *  TSN number in the datagram that was originally marked with the
 654  *  CE bit.
 655  *
 656  *     0                   1                   2                   3
 657  *     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
 658  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 659  *    | Chunk Type=13 | Flags=00000000|    Chunk Length = 8           |
 660  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 661  *    |                      Lowest TSN Number                        |
 662  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 663  *
 664  *     Note: The CWR is considered a Control chunk.
 665  */
 666 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
 667                                  const __u32 lowest_tsn,
 668                                  const struct sctp_chunk *chunk)
 669 {
 670         struct sctp_chunk *retval;
 671         struct sctp_cwrhdr cwr;
 672 
 673         cwr.lowest_tsn = htonl(lowest_tsn);
 674         retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
 675                                    sizeof(cwr), GFP_ATOMIC);
 676 
 677         if (!retval)
 678                 goto nodata;
 679 
 680         retval->subh.ecn_cwr_hdr =
 681                 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
 682 
 683         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 684          *
 685          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 686          * HEARTBEAT ACK, * etc.) to the same destination transport
 687          * address from which it * received the DATA or control chunk
 688          * to which it is replying.
 689          *
 690          * [Report a reduced congestion window back to where the ECNE
 691          * came from.]
 692          */
 693         if (chunk)
 694                 retval->transport = chunk->transport;
 695 
 696 nodata:
 697         return retval;
 698 }
 699 
 700 /* Make an ECNE chunk.  This is a congestion experienced report.  */
 701 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
 702                                   const __u32 lowest_tsn)
 703 {
 704         struct sctp_chunk *retval;
 705         struct sctp_ecnehdr ecne;
 706 
 707         ecne.lowest_tsn = htonl(lowest_tsn);
 708         retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
 709                                    sizeof(ecne), GFP_ATOMIC);
 710         if (!retval)
 711                 goto nodata;
 712         retval->subh.ecne_hdr =
 713                 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
 714 
 715 nodata:
 716         return retval;
 717 }
 718 
 719 /* Make a DATA chunk for the given association from the provided
 720  * parameters.  However, do not populate the data payload.
 721  */
 722 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
 723                                             const struct sctp_sndrcvinfo *sinfo,
 724                                             int len, __u8 flags, gfp_t gfp)
 725 {
 726         struct sctp_chunk *retval;
 727         struct sctp_datahdr dp;
 728 
 729         /* We assign the TSN as LATE as possible, not here when
 730          * creating the chunk.
 731          */
 732         memset(&dp, 0, sizeof(dp));
 733         dp.ppid = sinfo->sinfo_ppid;
 734         dp.stream = htons(sinfo->sinfo_stream);
 735 
 736         /* Set the flags for an unordered send.  */
 737         if (sinfo->sinfo_flags & SCTP_UNORDERED)
 738                 flags |= SCTP_DATA_UNORDERED;
 739 
 740         retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
 741         if (!retval)
 742                 return NULL;
 743 
 744         retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
 745         memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
 746 
 747         return retval;
 748 }
 749 
 750 /* Create a selective ackowledgement (SACK) for the given
 751  * association.  This reports on which TSN's we've seen to date,
 752  * including duplicates and gaps.
 753  */
 754 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
 755 {
 756         struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
 757         struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
 758         __u16 num_gabs, num_dup_tsns;
 759         struct sctp_transport *trans;
 760         struct sctp_chunk *retval;
 761         struct sctp_sackhdr sack;
 762         __u32 ctsn;
 763         int len;
 764 
 765         memset(gabs, 0, sizeof(gabs));
 766         ctsn = sctp_tsnmap_get_ctsn(map);
 767 
 768         pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
 769 
 770         /* How much room is needed in the chunk? */
 771         num_gabs = sctp_tsnmap_num_gabs(map, gabs);
 772         num_dup_tsns = sctp_tsnmap_num_dups(map);
 773 
 774         /* Initialize the SACK header.  */
 775         sack.cum_tsn_ack            = htonl(ctsn);
 776         sack.a_rwnd                 = htonl(asoc->a_rwnd);
 777         sack.num_gap_ack_blocks     = htons(num_gabs);
 778         sack.num_dup_tsns           = htons(num_dup_tsns);
 779 
 780         len = sizeof(sack)
 781                 + sizeof(struct sctp_gap_ack_block) * num_gabs
 782                 + sizeof(__u32) * num_dup_tsns;
 783 
 784         /* Create the chunk.  */
 785         retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
 786         if (!retval)
 787                 goto nodata;
 788 
 789         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 790          *
 791          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 792          * HEARTBEAT ACK, etc.) to the same destination transport
 793          * address from which it received the DATA or control chunk to
 794          * which it is replying.  This rule should also be followed if
 795          * the endpoint is bundling DATA chunks together with the
 796          * reply chunk.
 797          *
 798          * However, when acknowledging multiple DATA chunks received
 799          * in packets from different source addresses in a single
 800          * SACK, the SACK chunk may be transmitted to one of the
 801          * destination transport addresses from which the DATA or
 802          * control chunks being acknowledged were received.
 803          *
 804          * [BUG:  We do not implement the following paragraph.
 805          * Perhaps we should remember the last transport we used for a
 806          * SACK and avoid that (if possible) if we have seen any
 807          * duplicates. --piggy]
 808          *
 809          * When a receiver of a duplicate DATA chunk sends a SACK to a
 810          * multi- homed endpoint it MAY be beneficial to vary the
 811          * destination address and not use the source address of the
 812          * DATA chunk.  The reason being that receiving a duplicate
 813          * from a multi-homed endpoint might indicate that the return
 814          * path (as specified in the source address of the DATA chunk)
 815          * for the SACK is broken.
 816          *
 817          * [Send to the address from which we last received a DATA chunk.]
 818          */
 819         retval->transport = asoc->peer.last_data_from;
 820 
 821         retval->subh.sack_hdr =
 822                 sctp_addto_chunk(retval, sizeof(sack), &sack);
 823 
 824         /* Add the gap ack block information.   */
 825         if (num_gabs)
 826                 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
 827                                  gabs);
 828 
 829         /* Add the duplicate TSN information.  */
 830         if (num_dup_tsns) {
 831                 asoc->stats.idupchunks += num_dup_tsns;
 832                 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
 833                                  sctp_tsnmap_get_dups(map));
 834         }
 835         /* Once we have a sack generated, check to see what our sack
 836          * generation is, if its 0, reset the transports to 0, and reset
 837          * the association generation to 1
 838          *
 839          * The idea is that zero is never used as a valid generation for the
 840          * association so no transport will match after a wrap event like this,
 841          * Until the next sack
 842          */
 843         if (++asoc->peer.sack_generation == 0) {
 844                 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
 845                                     transports)
 846                         trans->sack_generation = 0;
 847                 asoc->peer.sack_generation = 1;
 848         }
 849 nodata:
 850         return retval;
 851 }
 852 
 853 /* Make a SHUTDOWN chunk. */
 854 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
 855                                       const struct sctp_chunk *chunk)
 856 {
 857         struct sctp_shutdownhdr shut;
 858         struct sctp_chunk *retval;
 859         __u32 ctsn;
 860 
 861         if (chunk && chunk->asoc)
 862                 ctsn = sctp_tsnmap_get_ctsn(&chunk->asoc->peer.tsn_map);
 863         else
 864                 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 865 
 866         shut.cum_tsn_ack = htonl(ctsn);
 867 
 868         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
 869                                    sizeof(shut), GFP_ATOMIC);
 870         if (!retval)
 871                 goto nodata;
 872 
 873         retval->subh.shutdown_hdr =
 874                 sctp_addto_chunk(retval, sizeof(shut), &shut);
 875 
 876         if (chunk)
 877                 retval->transport = chunk->transport;
 878 nodata:
 879         return retval;
 880 }
 881 
 882 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
 883                                           const struct sctp_chunk *chunk)
 884 {
 885         struct sctp_chunk *retval;
 886 
 887         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
 888                                    GFP_ATOMIC);
 889 
 890         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 891          *
 892          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 893          * HEARTBEAT ACK, * etc.) to the same destination transport
 894          * address from which it * received the DATA or control chunk
 895          * to which it is replying.
 896          *
 897          * [ACK back to where the SHUTDOWN came from.]
 898          */
 899         if (retval && chunk)
 900                 retval->transport = chunk->transport;
 901 
 902         return retval;
 903 }
 904 
 905 struct sctp_chunk *sctp_make_shutdown_complete(
 906                                         const struct sctp_association *asoc,
 907                                         const struct sctp_chunk *chunk)
 908 {
 909         struct sctp_chunk *retval;
 910         __u8 flags = 0;
 911 
 912         /* Set the T-bit if we have no association (vtag will be
 913          * reflected)
 914          */
 915         flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
 916 
 917         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
 918                                    0, GFP_ATOMIC);
 919 
 920         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 921          *
 922          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 923          * HEARTBEAT ACK, * etc.) to the same destination transport
 924          * address from which it * received the DATA or control chunk
 925          * to which it is replying.
 926          *
 927          * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
 928          * came from.]
 929          */
 930         if (retval && chunk)
 931                 retval->transport = chunk->transport;
 932 
 933         return retval;
 934 }
 935 
 936 /* Create an ABORT.  Note that we set the T bit if we have no
 937  * association, except when responding to an INIT (sctpimpguide 2.41).
 938  */
 939 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
 940                                    const struct sctp_chunk *chunk,
 941                                    const size_t hint)
 942 {
 943         struct sctp_chunk *retval;
 944         __u8 flags = 0;
 945 
 946         /* Set the T-bit if we have no association and 'chunk' is not
 947          * an INIT (vtag will be reflected).
 948          */
 949         if (!asoc) {
 950                 if (chunk && chunk->chunk_hdr &&
 951                     chunk->chunk_hdr->type == SCTP_CID_INIT)
 952                         flags = 0;
 953                 else
 954                         flags = SCTP_CHUNK_FLAG_T;
 955         }
 956 
 957         retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
 958                                    GFP_ATOMIC);
 959 
 960         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 961          *
 962          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 963          * HEARTBEAT ACK, * etc.) to the same destination transport
 964          * address from which it * received the DATA or control chunk
 965          * to which it is replying.
 966          *
 967          * [ABORT back to where the offender came from.]
 968          */
 969         if (retval && chunk)
 970                 retval->transport = chunk->transport;
 971 
 972         return retval;
 973 }
 974 
 975 /* Helper to create ABORT with a NO_USER_DATA error.  */
 976 struct sctp_chunk *sctp_make_abort_no_data(
 977                                         const struct sctp_association *asoc,
 978                                         const struct sctp_chunk *chunk,
 979                                         __u32 tsn)
 980 {
 981         struct sctp_chunk *retval;
 982         __be32 payload;
 983 
 984         retval = sctp_make_abort(asoc, chunk,
 985                                  sizeof(struct sctp_errhdr) + sizeof(tsn));
 986 
 987         if (!retval)
 988                 goto no_mem;
 989 
 990         /* Put the tsn back into network byte order.  */
 991         payload = htonl(tsn);
 992         sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
 993         sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
 994 
 995         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
 996          *
 997          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
 998          * HEARTBEAT ACK, * etc.) to the same destination transport
 999          * address from which it * received the DATA or control chunk
1000          * to which it is replying.
1001          *
1002          * [ABORT back to where the offender came from.]
1003          */
1004         if (chunk)
1005                 retval->transport = chunk->transport;
1006 
1007 no_mem:
1008         return retval;
1009 }
1010 
1011 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error.  */
1012 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1013                                         struct msghdr *msg,
1014                                         size_t paylen)
1015 {
1016         struct sctp_chunk *retval;
1017         void *payload = NULL;
1018         int err;
1019 
1020         retval = sctp_make_abort(asoc, NULL,
1021                                  sizeof(struct sctp_errhdr) + paylen);
1022         if (!retval)
1023                 goto err_chunk;
1024 
1025         if (paylen) {
1026                 /* Put the msg_iov together into payload.  */
1027                 payload = kmalloc(paylen, GFP_KERNEL);
1028                 if (!payload)
1029                         goto err_payload;
1030 
1031                 err = memcpy_from_msg(payload, msg, paylen);
1032                 if (err < 0)
1033                         goto err_copy;
1034         }
1035 
1036         sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1037         sctp_addto_chunk(retval, paylen, payload);
1038 
1039         if (paylen)
1040                 kfree(payload);
1041 
1042         return retval;
1043 
1044 err_copy:
1045         kfree(payload);
1046 err_payload:
1047         sctp_chunk_free(retval);
1048         retval = NULL;
1049 err_chunk:
1050         return retval;
1051 }
1052 
1053 /* Append bytes to the end of a parameter.  Will panic if chunk is not big
1054  * enough.
1055  */
1056 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1057                               const void *data)
1058 {
1059         int chunklen = ntohs(chunk->chunk_hdr->length);
1060         void *target;
1061 
1062         target = skb_put(chunk->skb, len);
1063 
1064         if (data)
1065                 memcpy(target, data, len);
1066         else
1067                 memset(target, 0, len);
1068 
1069         /* Adjust the chunk length field.  */
1070         chunk->chunk_hdr->length = htons(chunklen + len);
1071         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1072 
1073         return target;
1074 }
1075 
1076 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1077 struct sctp_chunk *sctp_make_abort_violation(
1078                                         const struct sctp_association *asoc,
1079                                         const struct sctp_chunk *chunk,
1080                                         const __u8 *payload,
1081                                         const size_t paylen)
1082 {
1083         struct sctp_chunk  *retval;
1084         struct sctp_paramhdr phdr;
1085 
1086         retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
1087                                               paylen + sizeof(phdr));
1088         if (!retval)
1089                 goto end;
1090 
1091         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
1092                                                             sizeof(phdr));
1093 
1094         phdr.type = htons(chunk->chunk_hdr->type);
1095         phdr.length = chunk->chunk_hdr->length;
1096         sctp_addto_chunk(retval, paylen, payload);
1097         sctp_addto_param(retval, sizeof(phdr), &phdr);
1098 
1099 end:
1100         return retval;
1101 }
1102 
1103 struct sctp_chunk *sctp_make_violation_paramlen(
1104                                         const struct sctp_association *asoc,
1105                                         const struct sctp_chunk *chunk,
1106                                         struct sctp_paramhdr *param)
1107 {
1108         static const char error[] = "The following parameter had invalid length:";
1109         size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1110                              sizeof(*param);
1111         struct sctp_chunk *retval;
1112 
1113         retval = sctp_make_abort(asoc, chunk, payload_len);
1114         if (!retval)
1115                 goto nodata;
1116 
1117         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1118                         sizeof(error) + sizeof(*param));
1119         sctp_addto_chunk(retval, sizeof(error), error);
1120         sctp_addto_param(retval, sizeof(*param), param);
1121 
1122 nodata:
1123         return retval;
1124 }
1125 
1126 struct sctp_chunk *sctp_make_violation_max_retrans(
1127                                         const struct sctp_association *asoc,
1128                                         const struct sctp_chunk *chunk)
1129 {
1130         static const char error[] = "Association exceeded its max_retrans count";
1131         size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1132         struct sctp_chunk *retval;
1133 
1134         retval = sctp_make_abort(asoc, chunk, payload_len);
1135         if (!retval)
1136                 goto nodata;
1137 
1138         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1139         sctp_addto_chunk(retval, sizeof(error), error);
1140 
1141 nodata:
1142         return retval;
1143 }
1144 
1145 /* Make a HEARTBEAT chunk.  */
1146 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1147                                        const struct sctp_transport *transport)
1148 {
1149         struct sctp_sender_hb_info hbinfo;
1150         struct sctp_chunk *retval;
1151 
1152         retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1153                                    sizeof(hbinfo), GFP_ATOMIC);
1154 
1155         if (!retval)
1156                 goto nodata;
1157 
1158         hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1159         hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1160         hbinfo.daddr = transport->ipaddr;
1161         hbinfo.sent_at = jiffies;
1162         hbinfo.hb_nonce = transport->hb_nonce;
1163 
1164         /* Cast away the 'const', as this is just telling the chunk
1165          * what transport it belongs to.
1166          */
1167         retval->transport = (struct sctp_transport *) transport;
1168         retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1169                                                 &hbinfo);
1170 
1171 nodata:
1172         return retval;
1173 }
1174 
1175 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1176                                            const struct sctp_chunk *chunk,
1177                                            const void *payload,
1178                                            const size_t paylen)
1179 {
1180         struct sctp_chunk *retval;
1181 
1182         retval  = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1183                                     GFP_ATOMIC);
1184         if (!retval)
1185                 goto nodata;
1186 
1187         retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1188 
1189         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1190          *
1191          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1192          * HEARTBEAT ACK, * etc.) to the same destination transport
1193          * address from which it * received the DATA or control chunk
1194          * to which it is replying.
1195          *
1196          * [HBACK back to where the HEARTBEAT came from.]
1197          */
1198         if (chunk)
1199                 retval->transport = chunk->transport;
1200 
1201 nodata:
1202         return retval;
1203 }
1204 
1205 /* Create an Operation Error chunk with the specified space reserved.
1206  * This routine can be used for containing multiple causes in the chunk.
1207  */
1208 static struct sctp_chunk *sctp_make_op_error_space(
1209                                         const struct sctp_association *asoc,
1210                                         const struct sctp_chunk *chunk,
1211                                         size_t size)
1212 {
1213         struct sctp_chunk *retval;
1214 
1215         retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1216                                    sizeof(struct sctp_errhdr) + size,
1217                                    GFP_ATOMIC);
1218         if (!retval)
1219                 goto nodata;
1220 
1221         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1222          *
1223          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1224          * HEARTBEAT ACK, etc.) to the same destination transport
1225          * address from which it received the DATA or control chunk
1226          * to which it is replying.
1227          *
1228          */
1229         if (chunk)
1230                 retval->transport = chunk->transport;
1231 
1232 nodata:
1233         return retval;
1234 }
1235 
1236 /* Create an Operation Error chunk of a fixed size, specifically,
1237  * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
1238  * This is a helper function to allocate an error chunk for for those
1239  * invalid parameter codes in which we may not want to report all the
1240  * errors, if the incoming chunk is large. If it can't fit in a single
1241  * packet, we ignore it.
1242  */
1243 static inline struct sctp_chunk *sctp_make_op_error_limited(
1244                                         const struct sctp_association *asoc,
1245                                         const struct sctp_chunk *chunk)
1246 {
1247         size_t size = SCTP_DEFAULT_MAXSEGMENT;
1248         struct sctp_sock *sp = NULL;
1249 
1250         if (asoc) {
1251                 size = min_t(size_t, size, asoc->pathmtu);
1252                 sp = sctp_sk(asoc->base.sk);
1253         }
1254 
1255         size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1256 
1257         return sctp_make_op_error_space(asoc, chunk, size);
1258 }
1259 
1260 /* Create an Operation Error chunk.  */
1261 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1262                                       const struct sctp_chunk *chunk,
1263                                       __be16 cause_code, const void *payload,
1264                                       size_t paylen, size_t reserve_tail)
1265 {
1266         struct sctp_chunk *retval;
1267 
1268         retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1269         if (!retval)
1270                 goto nodata;
1271 
1272         sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1273         sctp_addto_chunk(retval, paylen, payload);
1274         if (reserve_tail)
1275                 sctp_addto_param(retval, reserve_tail, NULL);
1276 
1277 nodata:
1278         return retval;
1279 }
1280 
1281 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1282                                   __u16 key_id)
1283 {
1284         struct sctp_authhdr auth_hdr;
1285         struct sctp_hmac *hmac_desc;
1286         struct sctp_chunk *retval;
1287 
1288         /* Get the first hmac that the peer told us to use */
1289         hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1290         if (unlikely(!hmac_desc))
1291                 return NULL;
1292 
1293         retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1294                                    hmac_desc->hmac_len + sizeof(auth_hdr),
1295                                    GFP_ATOMIC);
1296         if (!retval)
1297                 return NULL;
1298 
1299         auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1300         auth_hdr.shkey_id = htons(key_id);
1301 
1302         retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1303                                                  &auth_hdr);
1304 
1305         skb_put_zero(retval->skb, hmac_desc->hmac_len);
1306 
1307         /* Adjust the chunk header to include the empty MAC */
1308         retval->chunk_hdr->length =
1309                 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1310         retval->chunk_end = skb_tail_pointer(retval->skb);
1311 
1312         return retval;
1313 }
1314 
1315 
1316 /********************************************************************
1317  * 2nd Level Abstractions
1318  ********************************************************************/
1319 
1320 /* Turn an skb into a chunk.
1321  * FIXME: Eventually move the structure directly inside the skb->cb[].
1322  *
1323  * sctpimpguide-05.txt Section 2.8.2
1324  * M1) Each time a new DATA chunk is transmitted
1325  * set the 'TSN.Missing.Report' count for that TSN to 0. The
1326  * 'TSN.Missing.Report' count will be used to determine missing chunks
1327  * and when to fast retransmit.
1328  *
1329  */
1330 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1331                                  const struct sctp_association *asoc,
1332                                  struct sock *sk, gfp_t gfp)
1333 {
1334         struct sctp_chunk *retval;
1335 
1336         retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1337 
1338         if (!retval)
1339                 goto nodata;
1340         if (!sk)
1341                 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1342 
1343         INIT_LIST_HEAD(&retval->list);
1344         retval->skb             = skb;
1345         retval->asoc            = (struct sctp_association *)asoc;
1346         retval->singleton       = 1;
1347 
1348         retval->fast_retransmit = SCTP_CAN_FRTX;
1349 
1350         /* Polish the bead hole.  */
1351         INIT_LIST_HEAD(&retval->transmitted_list);
1352         INIT_LIST_HEAD(&retval->frag_list);
1353         SCTP_DBG_OBJCNT_INC(chunk);
1354         refcount_set(&retval->refcnt, 1);
1355 
1356 nodata:
1357         return retval;
1358 }
1359 
1360 /* Set chunk->source and dest based on the IP header in chunk->skb.  */
1361 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1362                      union sctp_addr *dest)
1363 {
1364         memcpy(&chunk->source, src, sizeof(union sctp_addr));
1365         memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1366 }
1367 
1368 /* Extract the source address from a chunk.  */
1369 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1370 {
1371         /* If we have a known transport, use that.  */
1372         if (chunk->transport) {
1373                 return &chunk->transport->ipaddr;
1374         } else {
1375                 /* Otherwise, extract it from the IP header.  */
1376                 return &chunk->source;
1377         }
1378 }
1379 
1380 /* Create a new chunk, setting the type and flags headers from the
1381  * arguments, reserving enough space for a 'paylen' byte payload.
1382  */
1383 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1384                                            __u8 type, __u8 flags, int paylen,
1385                                            gfp_t gfp)
1386 {
1387         struct sctp_chunkhdr *chunk_hdr;
1388         struct sctp_chunk *retval;
1389         struct sk_buff *skb;
1390         struct sock *sk;
1391         int chunklen;
1392 
1393         chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1394         if (chunklen > SCTP_MAX_CHUNK_LEN)
1395                 goto nodata;
1396 
1397         /* No need to allocate LL here, as this is only a chunk. */
1398         skb = alloc_skb(chunklen, gfp);
1399         if (!skb)
1400                 goto nodata;
1401 
1402         /* Make room for the chunk header.  */
1403         chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1404         chunk_hdr->type   = type;
1405         chunk_hdr->flags  = flags;
1406         chunk_hdr->length = htons(sizeof(*chunk_hdr));
1407 
1408         sk = asoc ? asoc->base.sk : NULL;
1409         retval = sctp_chunkify(skb, asoc, sk, gfp);
1410         if (!retval) {
1411                 kfree_skb(skb);
1412                 goto nodata;
1413         }
1414 
1415         retval->chunk_hdr = chunk_hdr;
1416         retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1417 
1418         /* Determine if the chunk needs to be authenticated */
1419         if (sctp_auth_send_cid(type, asoc))
1420                 retval->auth = 1;
1421 
1422         return retval;
1423 nodata:
1424         return NULL;
1425 }
1426 
1427 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1428                                          __u8 flags, int paylen, gfp_t gfp)
1429 {
1430         return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1431 }
1432 
1433 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1434                                    __u8 flags, int paylen, gfp_t gfp)
1435 {
1436         return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1437 }
1438 
1439 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1440                                             __u8 type, __u8 flags, int paylen,
1441                                             gfp_t gfp)
1442 {
1443         struct sctp_chunk *chunk;
1444 
1445         chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1446         if (chunk)
1447                 sctp_control_set_owner_w(chunk);
1448 
1449         return chunk;
1450 }
1451 
1452 /* Release the memory occupied by a chunk.  */
1453 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1454 {
1455         BUG_ON(!list_empty(&chunk->list));
1456         list_del_init(&chunk->transmitted_list);
1457 
1458         consume_skb(chunk->skb);
1459         consume_skb(chunk->auth_chunk);
1460 
1461         SCTP_DBG_OBJCNT_DEC(chunk);
1462         kmem_cache_free(sctp_chunk_cachep, chunk);
1463 }
1464 
1465 /* Possibly, free the chunk.  */
1466 void sctp_chunk_free(struct sctp_chunk *chunk)
1467 {
1468         /* Release our reference on the message tracker. */
1469         if (chunk->msg)
1470                 sctp_datamsg_put(chunk->msg);
1471 
1472         sctp_chunk_put(chunk);
1473 }
1474 
1475 /* Grab a reference to the chunk. */
1476 void sctp_chunk_hold(struct sctp_chunk *ch)
1477 {
1478         refcount_inc(&ch->refcnt);
1479 }
1480 
1481 /* Release a reference to the chunk. */
1482 void sctp_chunk_put(struct sctp_chunk *ch)
1483 {
1484         if (refcount_dec_and_test(&ch->refcnt))
1485                 sctp_chunk_destroy(ch);
1486 }
1487 
1488 /* Append bytes to the end of a chunk.  Will panic if chunk is not big
1489  * enough.
1490  */
1491 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1492 {
1493         int chunklen = ntohs(chunk->chunk_hdr->length);
1494         int padlen = SCTP_PAD4(chunklen) - chunklen;
1495         void *target;
1496 
1497         skb_put_zero(chunk->skb, padlen);
1498         target = skb_put_data(chunk->skb, data, len);
1499 
1500         /* Adjust the chunk length field.  */
1501         chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1502         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1503 
1504         return target;
1505 }
1506 
1507 /* Append bytes from user space to the end of a chunk.  Will panic if
1508  * chunk is not big enough.
1509  * Returns a kernel err value.
1510  */
1511 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1512                           struct iov_iter *from)
1513 {
1514         void *target;
1515 
1516         /* Make room in chunk for data.  */
1517         target = skb_put(chunk->skb, len);
1518 
1519         /* Copy data (whole iovec) into chunk */
1520         if (!copy_from_iter_full(target, len, from))
1521                 return -EFAULT;
1522 
1523         /* Adjust the chunk length field.  */
1524         chunk->chunk_hdr->length =
1525                 htons(ntohs(chunk->chunk_hdr->length) + len);
1526         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1527 
1528         return 0;
1529 }
1530 
1531 /* Helper function to assign a TSN if needed.  This assumes that both
1532  * the data_hdr and association have already been assigned.
1533  */
1534 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1535 {
1536         struct sctp_stream *stream;
1537         struct sctp_chunk *lchunk;
1538         struct sctp_datamsg *msg;
1539         __u16 ssn, sid;
1540 
1541         if (chunk->has_ssn)
1542                 return;
1543 
1544         /* All fragments will be on the same stream */
1545         sid = ntohs(chunk->subh.data_hdr->stream);
1546         stream = &chunk->asoc->stream;
1547 
1548         /* Now assign the sequence number to the entire message.
1549          * All fragments must have the same stream sequence number.
1550          */
1551         msg = chunk->msg;
1552         list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1553                 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1554                         ssn = 0;
1555                 } else {
1556                         if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1557                                 ssn = sctp_ssn_next(stream, out, sid);
1558                         else
1559                                 ssn = sctp_ssn_peek(stream, out, sid);
1560                 }
1561 
1562                 lchunk->subh.data_hdr->ssn = htons(ssn);
1563                 lchunk->has_ssn = 1;
1564         }
1565 }
1566 
1567 /* Helper function to assign a TSN if needed.  This assumes that both
1568  * the data_hdr and association have already been assigned.
1569  */
1570 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1571 {
1572         if (!chunk->has_tsn) {
1573                 /* This is the last possible instant to
1574                  * assign a TSN.
1575                  */
1576                 chunk->subh.data_hdr->tsn =
1577                         htonl(sctp_association_get_next_tsn(chunk->asoc));
1578                 chunk->has_tsn = 1;
1579         }
1580 }
1581 
1582 /* Create a CLOSED association to use with an incoming packet.  */
1583 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1584                                              struct sctp_chunk *chunk,
1585                                              gfp_t gfp)
1586 {
1587         struct sctp_association *asoc;
1588         enum sctp_scope scope;
1589         struct sk_buff *skb;
1590 
1591         /* Create the bare association.  */
1592         scope = sctp_scope(sctp_source(chunk));
1593         asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1594         if (!asoc)
1595                 goto nodata;
1596         asoc->temp = 1;
1597         skb = chunk->skb;
1598         /* Create an entry for the source address of the packet.  */
1599         SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1600 
1601 nodata:
1602         return asoc;
1603 }
1604 
1605 /* Build a cookie representing asoc.
1606  * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1607  */
1608 static struct sctp_cookie_param *sctp_pack_cookie(
1609                                         const struct sctp_endpoint *ep,
1610                                         const struct sctp_association *asoc,
1611                                         const struct sctp_chunk *init_chunk,
1612                                         int *cookie_len, const __u8 *raw_addrs,
1613                                         int addrs_len)
1614 {
1615         struct sctp_signed_cookie *cookie;
1616         struct sctp_cookie_param *retval;
1617         int headersize, bodysize;
1618 
1619         /* Header size is static data prior to the actual cookie, including
1620          * any padding.
1621          */
1622         headersize = sizeof(struct sctp_paramhdr) +
1623                      (sizeof(struct sctp_signed_cookie) -
1624                       sizeof(struct sctp_cookie));
1625         bodysize = sizeof(struct sctp_cookie)
1626                 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1627 
1628         /* Pad out the cookie to a multiple to make the signature
1629          * functions simpler to write.
1630          */
1631         if (bodysize % SCTP_COOKIE_MULTIPLE)
1632                 bodysize += SCTP_COOKIE_MULTIPLE
1633                         - (bodysize % SCTP_COOKIE_MULTIPLE);
1634         *cookie_len = headersize + bodysize;
1635 
1636         /* Clear this memory since we are sending this data structure
1637          * out on the network.
1638          */
1639         retval = kzalloc(*cookie_len, GFP_ATOMIC);
1640         if (!retval)
1641                 goto nodata;
1642 
1643         cookie = (struct sctp_signed_cookie *) retval->body;
1644 
1645         /* Set up the parameter header.  */
1646         retval->p.type = SCTP_PARAM_STATE_COOKIE;
1647         retval->p.length = htons(*cookie_len);
1648 
1649         /* Copy the cookie part of the association itself.  */
1650         cookie->c = asoc->c;
1651         /* Save the raw address list length in the cookie. */
1652         cookie->c.raw_addr_list_len = addrs_len;
1653 
1654         /* Remember PR-SCTP capability. */
1655         cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1656 
1657         /* Save adaptation indication in the cookie. */
1658         cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1659 
1660         /* Set an expiration time for the cookie.  */
1661         cookie->c.expiration = ktime_add(asoc->cookie_life,
1662                                          ktime_get_real());
1663 
1664         /* Copy the peer's init packet.  */
1665         memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1666                ntohs(init_chunk->chunk_hdr->length));
1667 
1668         /* Copy the raw local address list of the association. */
1669         memcpy((__u8 *)&cookie->c.peer_init[0] +
1670                ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1671 
1672         if (sctp_sk(ep->base.sk)->hmac) {
1673                 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1674                 int err;
1675 
1676                 /* Sign the message.  */
1677                 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1678 
1679                 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1680                                           sizeof(ep->secret_key)) ?:
1681                       crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
1682                                           cookie->signature);
1683                 shash_desc_zero(desc);
1684                 if (err)
1685                         goto free_cookie;
1686         }
1687 
1688         return retval;
1689 
1690 free_cookie:
1691         kfree(retval);
1692 nodata:
1693         *cookie_len = 0;
1694         return NULL;
1695 }
1696 
1697 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
1698 struct sctp_association *sctp_unpack_cookie(
1699                                         const struct sctp_endpoint *ep,
1700                                         const struct sctp_association *asoc,
1701                                         struct sctp_chunk *chunk, gfp_t gfp,
1702                                         int *error, struct sctp_chunk **errp)
1703 {
1704         struct sctp_association *retval = NULL;
1705         int headersize, bodysize, fixed_size;
1706         struct sctp_signed_cookie *cookie;
1707         struct sk_buff *skb = chunk->skb;
1708         struct sctp_cookie *bear_cookie;
1709         __u8 *digest = ep->digest;
1710         enum sctp_scope scope;
1711         unsigned int len;
1712         ktime_t kt;
1713 
1714         /* Header size is static data prior to the actual cookie, including
1715          * any padding.
1716          */
1717         headersize = sizeof(struct sctp_chunkhdr) +
1718                      (sizeof(struct sctp_signed_cookie) -
1719                       sizeof(struct sctp_cookie));
1720         bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1721         fixed_size = headersize + sizeof(struct sctp_cookie);
1722 
1723         /* Verify that the chunk looks like it even has a cookie.
1724          * There must be enough room for our cookie and our peer's
1725          * INIT chunk.
1726          */
1727         len = ntohs(chunk->chunk_hdr->length);
1728         if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1729                 goto malformed;
1730 
1731         /* Verify that the cookie has been padded out. */
1732         if (bodysize % SCTP_COOKIE_MULTIPLE)
1733                 goto malformed;
1734 
1735         /* Process the cookie.  */
1736         cookie = chunk->subh.cookie_hdr;
1737         bear_cookie = &cookie->c;
1738 
1739         if (!sctp_sk(ep->base.sk)->hmac)
1740                 goto no_hmac;
1741 
1742         /* Check the signature.  */
1743         {
1744                 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1745                 int err;
1746 
1747                 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1748 
1749                 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1750                                           sizeof(ep->secret_key)) ?:
1751                       crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
1752                                           digest);
1753                 shash_desc_zero(desc);
1754 
1755                 if (err) {
1756                         *error = -SCTP_IERROR_NOMEM;
1757                         goto fail;
1758                 }
1759         }
1760 
1761         if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1762                 *error = -SCTP_IERROR_BAD_SIG;
1763                 goto fail;
1764         }
1765 
1766 no_hmac:
1767         /* IG Section 2.35.2:
1768          *  3) Compare the port numbers and the verification tag contained
1769          *     within the COOKIE ECHO chunk to the actual port numbers and the
1770          *     verification tag within the SCTP common header of the received
1771          *     packet. If these values do not match the packet MUST be silently
1772          *     discarded,
1773          */
1774         if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1775                 *error = -SCTP_IERROR_BAD_TAG;
1776                 goto fail;
1777         }
1778 
1779         if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1780             ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1781                 *error = -SCTP_IERROR_BAD_PORTS;
1782                 goto fail;
1783         }
1784 
1785         /* Check to see if the cookie is stale.  If there is already
1786          * an association, there is no need to check cookie's expiration
1787          * for init collision case of lost COOKIE ACK.
1788          * If skb has been timestamped, then use the stamp, otherwise
1789          * use current time.  This introduces a small possibility that
1790          * that a cookie may be considered expired, but his would only slow
1791          * down the new association establishment instead of every packet.
1792          */
1793         if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1794                 kt = skb_get_ktime(skb);
1795         else
1796                 kt = ktime_get_real();
1797 
1798         if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1799                 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1800                 __be32 n = htonl(usecs);
1801 
1802                 /*
1803                  * Section 3.3.10.3 Stale Cookie Error (3)
1804                  *
1805                  * Cause of error
1806                  * ---------------
1807                  * Stale Cookie Error:  Indicates the receipt of a valid State
1808                  * Cookie that has expired.
1809                  */
1810                 *errp = sctp_make_op_error(asoc, chunk,
1811                                            SCTP_ERROR_STALE_COOKIE, &n,
1812                                            sizeof(n), 0);
1813                 if (*errp)
1814                         *error = -SCTP_IERROR_STALE_COOKIE;
1815                 else
1816                         *error = -SCTP_IERROR_NOMEM;
1817 
1818                 goto fail;
1819         }
1820 
1821         /* Make a new base association.  */
1822         scope = sctp_scope(sctp_source(chunk));
1823         retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1824         if (!retval) {
1825                 *error = -SCTP_IERROR_NOMEM;
1826                 goto fail;
1827         }
1828 
1829         /* Set up our peer's port number.  */
1830         retval->peer.port = ntohs(chunk->sctp_hdr->source);
1831 
1832         /* Populate the association from the cookie.  */
1833         memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1834 
1835         if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1836                                                  GFP_ATOMIC) < 0) {
1837                 *error = -SCTP_IERROR_NOMEM;
1838                 goto fail;
1839         }
1840 
1841         /* Also, add the destination address. */
1842         if (list_empty(&retval->base.bind_addr.address_list)) {
1843                 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1844                                    sizeof(chunk->dest), SCTP_ADDR_SRC,
1845                                    GFP_ATOMIC);
1846         }
1847 
1848         retval->next_tsn = retval->c.initial_tsn;
1849         retval->ctsn_ack_point = retval->next_tsn - 1;
1850         retval->addip_serial = retval->c.initial_tsn;
1851         retval->strreset_outseq = retval->c.initial_tsn;
1852         retval->adv_peer_ack_point = retval->ctsn_ack_point;
1853         retval->peer.prsctp_capable = retval->c.prsctp_capable;
1854         retval->peer.adaptation_ind = retval->c.adaptation_ind;
1855 
1856         /* The INIT stuff will be done by the side effects.  */
1857         return retval;
1858 
1859 fail:
1860         if (retval)
1861                 sctp_association_free(retval);
1862 
1863         return NULL;
1864 
1865 malformed:
1866         /* Yikes!  The packet is either corrupt or deliberately
1867          * malformed.
1868          */
1869         *error = -SCTP_IERROR_MALFORMED;
1870         goto fail;
1871 }
1872 
1873 /********************************************************************
1874  * 3rd Level Abstractions
1875  ********************************************************************/
1876 
1877 struct __sctp_missing {
1878         __be32 num_missing;
1879         __be16 type;
1880 }  __packed;
1881 
1882 /*
1883  * Report a missing mandatory parameter.
1884  */
1885 static int sctp_process_missing_param(const struct sctp_association *asoc,
1886                                       enum sctp_param paramtype,
1887                                       struct sctp_chunk *chunk,
1888                                       struct sctp_chunk **errp)
1889 {
1890         struct __sctp_missing report;
1891         __u16 len;
1892 
1893         len = SCTP_PAD4(sizeof(report));
1894 
1895         /* Make an ERROR chunk, preparing enough room for
1896          * returning multiple unknown parameters.
1897          */
1898         if (!*errp)
1899                 *errp = sctp_make_op_error_space(asoc, chunk, len);
1900 
1901         if (*errp) {
1902                 report.num_missing = htonl(1);
1903                 report.type = paramtype;
1904                 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1905                                 sizeof(report));
1906                 sctp_addto_chunk(*errp, sizeof(report), &report);
1907         }
1908 
1909         /* Stop processing this chunk. */
1910         return 0;
1911 }
1912 
1913 /* Report an Invalid Mandatory Parameter.  */
1914 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1915                                       struct sctp_chunk *chunk,
1916                                       struct sctp_chunk **errp)
1917 {
1918         /* Invalid Mandatory Parameter Error has no payload. */
1919 
1920         if (!*errp)
1921                 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1922 
1923         if (*errp)
1924                 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1925 
1926         /* Stop processing this chunk. */
1927         return 0;
1928 }
1929 
1930 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1931                                         struct sctp_paramhdr *param,
1932                                         const struct sctp_chunk *chunk,
1933                                         struct sctp_chunk **errp)
1934 {
1935         /* This is a fatal error.  Any accumulated non-fatal errors are
1936          * not reported.
1937          */
1938         if (*errp)
1939                 sctp_chunk_free(*errp);
1940 
1941         /* Create an error chunk and fill it in with our payload. */
1942         *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1943 
1944         return 0;
1945 }
1946 
1947 
1948 /* Do not attempt to handle the HOST_NAME parm.  However, do
1949  * send back an indicator to the peer.
1950  */
1951 static int sctp_process_hn_param(const struct sctp_association *asoc,
1952                                  union sctp_params param,
1953                                  struct sctp_chunk *chunk,
1954                                  struct sctp_chunk **errp)
1955 {
1956         __u16 len = ntohs(param.p->length);
1957 
1958         /* Processing of the HOST_NAME parameter will generate an
1959          * ABORT.  If we've accumulated any non-fatal errors, they
1960          * would be unrecognized parameters and we should not include
1961          * them in the ABORT.
1962          */
1963         if (*errp)
1964                 sctp_chunk_free(*errp);
1965 
1966         *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
1967                                    param.v, len, 0);
1968 
1969         /* Stop processing this chunk. */
1970         return 0;
1971 }
1972 
1973 static int sctp_verify_ext_param(struct net *net,
1974                                  const struct sctp_endpoint *ep,
1975                                  union sctp_params param)
1976 {
1977         __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
1978         int have_asconf = 0;
1979         int have_auth = 0;
1980         int i;
1981 
1982         for (i = 0; i < num_ext; i++) {
1983                 switch (param.ext->chunks[i]) {
1984                 case SCTP_CID_AUTH:
1985                         have_auth = 1;
1986                         break;
1987                 case SCTP_CID_ASCONF:
1988                 case SCTP_CID_ASCONF_ACK:
1989                         have_asconf = 1;
1990                         break;
1991                 }
1992         }
1993 
1994         /* ADD-IP Security: The draft requires us to ABORT or ignore the
1995          * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not.  Do this
1996          * only if ADD-IP is turned on and we are not backward-compatible
1997          * mode.
1998          */
1999         if (net->sctp.addip_noauth)
2000                 return 1;
2001 
2002         if (ep->asconf_enable && !have_auth && have_asconf)
2003                 return 0;
2004 
2005         return 1;
2006 }
2007 
2008 static void sctp_process_ext_param(struct sctp_association *asoc,
2009                                    union sctp_params param)
2010 {
2011         __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2012         int i;
2013 
2014         for (i = 0; i < num_ext; i++) {
2015                 switch (param.ext->chunks[i]) {
2016                 case SCTP_CID_RECONF:
2017                         if (asoc->ep->reconf_enable)
2018                                 asoc->peer.reconf_capable = 1;
2019                         break;
2020                 case SCTP_CID_FWD_TSN:
2021                         if (asoc->ep->prsctp_enable)
2022                                 asoc->peer.prsctp_capable = 1;
2023                         break;
2024                 case SCTP_CID_AUTH:
2025                         /* if the peer reports AUTH, assume that he
2026                          * supports AUTH.
2027                          */
2028                         if (asoc->ep->auth_enable)
2029                                 asoc->peer.auth_capable = 1;
2030                         break;
2031                 case SCTP_CID_ASCONF:
2032                 case SCTP_CID_ASCONF_ACK:
2033                         if (asoc->ep->asconf_enable)
2034                                 asoc->peer.asconf_capable = 1;
2035                         break;
2036                 case SCTP_CID_I_DATA:
2037                         if (asoc->ep->intl_enable)
2038                                 asoc->peer.intl_capable = 1;
2039                         break;
2040                 default:
2041                         break;
2042                 }
2043         }
2044 }
2045 
2046 /* RFC 3.2.1 & the Implementers Guide 2.2.
2047  *
2048  * The Parameter Types are encoded such that the
2049  * highest-order two bits specify the action that must be
2050  * taken if the processing endpoint does not recognize the
2051  * Parameter Type.
2052  *
2053  * 00 - Stop processing this parameter; do not process any further
2054  *      parameters within this chunk
2055  *
2056  * 01 - Stop processing this parameter, do not process any further
2057  *      parameters within this chunk, and report the unrecognized
2058  *      parameter in an 'Unrecognized Parameter' ERROR chunk.
2059  *
2060  * 10 - Skip this parameter and continue processing.
2061  *
2062  * 11 - Skip this parameter and continue processing but
2063  *      report the unrecognized parameter in an
2064  *      'Unrecognized Parameter' ERROR chunk.
2065  *
2066  * Return value:
2067  *      SCTP_IERROR_NO_ERROR - continue with the chunk
2068  *      SCTP_IERROR_ERROR    - stop and report an error.
2069  *      SCTP_IERROR_NOMEME   - out of memory.
2070  */
2071 static enum sctp_ierror sctp_process_unk_param(
2072                                         const struct sctp_association *asoc,
2073                                         union sctp_params param,
2074                                         struct sctp_chunk *chunk,
2075                                         struct sctp_chunk **errp)
2076 {
2077         int retval = SCTP_IERROR_NO_ERROR;
2078 
2079         switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2080         case SCTP_PARAM_ACTION_DISCARD:
2081                 retval =  SCTP_IERROR_ERROR;
2082                 break;
2083         case SCTP_PARAM_ACTION_SKIP:
2084                 break;
2085         case SCTP_PARAM_ACTION_DISCARD_ERR:
2086                 retval =  SCTP_IERROR_ERROR;
2087                 /* Fall through */
2088         case SCTP_PARAM_ACTION_SKIP_ERR:
2089                 /* Make an ERROR chunk, preparing enough room for
2090                  * returning multiple unknown parameters.
2091                  */
2092                 if (!*errp) {
2093                         *errp = sctp_make_op_error_limited(asoc, chunk);
2094                         if (!*errp) {
2095                                 /* If there is no memory for generating the
2096                                  * ERROR report as specified, an ABORT will be
2097                                  * triggered to the peer and the association
2098                                  * won't be established.
2099                                  */
2100                                 retval = SCTP_IERROR_NOMEM;
2101                                 break;
2102                         }
2103                 }
2104 
2105                 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2106                                      ntohs(param.p->length)))
2107                         sctp_addto_chunk(*errp, ntohs(param.p->length),
2108                                          param.v);
2109                 break;
2110         default:
2111                 break;
2112         }
2113 
2114         return retval;
2115 }
2116 
2117 /* Verify variable length parameters
2118  * Return values:
2119  *      SCTP_IERROR_ABORT - trigger an ABORT
2120  *      SCTP_IERROR_NOMEM - out of memory (abort)
2121  *      SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2122  *      SCTP_IERROR_NO_ERROR - continue with the chunk
2123  */
2124 static enum sctp_ierror sctp_verify_param(struct net *net,
2125                                           const struct sctp_endpoint *ep,
2126                                           const struct sctp_association *asoc,
2127                                           union sctp_params param,
2128                                           enum sctp_cid cid,
2129                                           struct sctp_chunk *chunk,
2130                                           struct sctp_chunk **err_chunk)
2131 {
2132         struct sctp_hmac_algo_param *hmacs;
2133         int retval = SCTP_IERROR_NO_ERROR;
2134         __u16 n_elt, id = 0;
2135         int i;
2136 
2137         /* FIXME - This routine is not looking at each parameter per the
2138          * chunk type, i.e., unrecognized parameters should be further
2139          * identified based on the chunk id.
2140          */
2141 
2142         switch (param.p->type) {
2143         case SCTP_PARAM_IPV4_ADDRESS:
2144         case SCTP_PARAM_IPV6_ADDRESS:
2145         case SCTP_PARAM_COOKIE_PRESERVATIVE:
2146         case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2147         case SCTP_PARAM_STATE_COOKIE:
2148         case SCTP_PARAM_HEARTBEAT_INFO:
2149         case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2150         case SCTP_PARAM_ECN_CAPABLE:
2151         case SCTP_PARAM_ADAPTATION_LAYER_IND:
2152                 break;
2153 
2154         case SCTP_PARAM_SUPPORTED_EXT:
2155                 if (!sctp_verify_ext_param(net, ep, param))
2156                         return SCTP_IERROR_ABORT;
2157                 break;
2158 
2159         case SCTP_PARAM_SET_PRIMARY:
2160                 if (ep->asconf_enable)
2161                         break;
2162                 goto unhandled;
2163 
2164         case SCTP_PARAM_HOST_NAME_ADDRESS:
2165                 /* Tell the peer, we won't support this param.  */
2166                 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2167                 retval = SCTP_IERROR_ABORT;
2168                 break;
2169 
2170         case SCTP_PARAM_FWD_TSN_SUPPORT:
2171                 if (ep->prsctp_enable)
2172                         break;
2173                 goto unhandled;
2174 
2175         case SCTP_PARAM_RANDOM:
2176                 if (!ep->auth_enable)
2177                         goto unhandled;
2178 
2179                 /* SCTP-AUTH: Secion 6.1
2180                  * If the random number is not 32 byte long the association
2181                  * MUST be aborted.  The ABORT chunk SHOULD contain the error
2182                  * cause 'Protocol Violation'.
2183                  */
2184                 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
2185                                                sizeof(struct sctp_paramhdr)) {
2186                         sctp_process_inv_paramlength(asoc, param.p,
2187                                                      chunk, err_chunk);
2188                         retval = SCTP_IERROR_ABORT;
2189                 }
2190                 break;
2191 
2192         case SCTP_PARAM_CHUNKS:
2193                 if (!ep->auth_enable)
2194                         goto unhandled;
2195 
2196                 /* SCTP-AUTH: Section 3.2
2197                  * The CHUNKS parameter MUST be included once in the INIT or
2198                  *  INIT-ACK chunk if the sender wants to receive authenticated
2199                  *  chunks.  Its maximum length is 260 bytes.
2200                  */
2201                 if (260 < ntohs(param.p->length)) {
2202                         sctp_process_inv_paramlength(asoc, param.p,
2203                                                      chunk, err_chunk);
2204                         retval = SCTP_IERROR_ABORT;
2205                 }
2206                 break;
2207 
2208         case SCTP_PARAM_HMAC_ALGO:
2209                 if (!ep->auth_enable)
2210                         goto unhandled;
2211 
2212                 hmacs = (struct sctp_hmac_algo_param *)param.p;
2213                 n_elt = (ntohs(param.p->length) -
2214                          sizeof(struct sctp_paramhdr)) >> 1;
2215 
2216                 /* SCTP-AUTH: Section 6.1
2217                  * The HMAC algorithm based on SHA-1 MUST be supported and
2218                  * included in the HMAC-ALGO parameter.
2219                  */
2220                 for (i = 0; i < n_elt; i++) {
2221                         id = ntohs(hmacs->hmac_ids[i]);
2222 
2223                         if (id == SCTP_AUTH_HMAC_ID_SHA1)
2224                                 break;
2225                 }
2226 
2227                 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2228                         sctp_process_inv_paramlength(asoc, param.p, chunk,
2229                                                      err_chunk);
2230                         retval = SCTP_IERROR_ABORT;
2231                 }
2232                 break;
2233 unhandled:
2234         default:
2235                 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2236                          __func__, ntohs(param.p->type), cid);
2237 
2238                 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2239                 break;
2240         }
2241         return retval;
2242 }
2243 
2244 /* Verify the INIT packet before we process it.  */
2245 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2246                      const struct sctp_association *asoc, enum sctp_cid cid,
2247                      struct sctp_init_chunk *peer_init,
2248                      struct sctp_chunk *chunk, struct sctp_chunk **errp)
2249 {
2250         union sctp_params param;
2251         bool has_cookie = false;
2252         int result;
2253 
2254         /* Check for missing mandatory parameters. Note: Initial TSN is
2255          * also mandatory, but is not checked here since the valid range
2256          * is 0..2**32-1. RFC4960, section 3.3.3.
2257          */
2258         if (peer_init->init_hdr.num_outbound_streams == 0 ||
2259             peer_init->init_hdr.num_inbound_streams == 0 ||
2260             peer_init->init_hdr.init_tag == 0 ||
2261             ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2262                 return sctp_process_inv_mandatory(asoc, chunk, errp);
2263 
2264         sctp_walk_params(param, peer_init, init_hdr.params) {
2265                 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2266                         has_cookie = true;
2267         }
2268 
2269         /* There is a possibility that a parameter length was bad and
2270          * in that case we would have stoped walking the parameters.
2271          * The current param.p would point at the bad one.
2272          * Current consensus on the mailing list is to generate a PROTOCOL
2273          * VIOLATION error.  We build the ERROR chunk here and let the normal
2274          * error handling code build and send the packet.
2275          */
2276         if (param.v != (void *)chunk->chunk_end)
2277                 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2278 
2279         /* The only missing mandatory param possible today is
2280          * the state cookie for an INIT-ACK chunk.
2281          */
2282         if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2283                 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2284                                                   chunk, errp);
2285 
2286         /* Verify all the variable length parameters */
2287         sctp_walk_params(param, peer_init, init_hdr.params) {
2288                 result = sctp_verify_param(net, ep, asoc, param, cid,
2289                                            chunk, errp);
2290                 switch (result) {
2291                 case SCTP_IERROR_ABORT:
2292                 case SCTP_IERROR_NOMEM:
2293                         return 0;
2294                 case SCTP_IERROR_ERROR:
2295                         return 1;
2296                 case SCTP_IERROR_NO_ERROR:
2297                 default:
2298                         break;
2299                 }
2300 
2301         } /* for (loop through all parameters) */
2302 
2303         return 1;
2304 }
2305 
2306 /* Unpack the parameters in an INIT packet into an association.
2307  * Returns 0 on failure, else success.
2308  * FIXME:  This is an association method.
2309  */
2310 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2311                       const union sctp_addr *peer_addr,
2312                       struct sctp_init_chunk *peer_init, gfp_t gfp)
2313 {
2314         struct net *net = sock_net(asoc->base.sk);
2315         struct sctp_transport *transport;
2316         struct list_head *pos, *temp;
2317         union sctp_params param;
2318         union sctp_addr addr;
2319         struct sctp_af *af;
2320         int src_match = 0;
2321 
2322         /* We must include the address that the INIT packet came from.
2323          * This is the only address that matters for an INIT packet.
2324          * When processing a COOKIE ECHO, we retrieve the from address
2325          * of the INIT from the cookie.
2326          */
2327 
2328         /* This implementation defaults to making the first transport
2329          * added as the primary transport.  The source address seems to
2330          * be a a better choice than any of the embedded addresses.
2331          */
2332         if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2333                 goto nomem;
2334 
2335         if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2336                 src_match = 1;
2337 
2338         /* Process the initialization parameters.  */
2339         sctp_walk_params(param, peer_init, init_hdr.params) {
2340                 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2341                     param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2342                         af = sctp_get_af_specific(param_type2af(param.p->type));
2343                         af->from_addr_param(&addr, param.addr,
2344                                             chunk->sctp_hdr->source, 0);
2345                         if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2346                                 src_match = 1;
2347                 }
2348 
2349                 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2350                         goto clean_up;
2351         }
2352 
2353         /* source address of chunk may not match any valid address */
2354         if (!src_match)
2355                 goto clean_up;
2356 
2357         /* AUTH: After processing the parameters, make sure that we
2358          * have all the required info to potentially do authentications.
2359          */
2360         if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2361                                         !asoc->peer.peer_hmacs))
2362                 asoc->peer.auth_capable = 0;
2363 
2364         /* In a non-backward compatible mode, if the peer claims
2365          * support for ADD-IP but not AUTH,  the ADD-IP spec states
2366          * that we MUST ABORT the association. Section 6.  The section
2367          * also give us an option to silently ignore the packet, which
2368          * is what we'll do here.
2369          */
2370         if (!net->sctp.addip_noauth &&
2371              (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2372                 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2373                                                   SCTP_PARAM_DEL_IP |
2374                                                   SCTP_PARAM_SET_PRIMARY);
2375                 asoc->peer.asconf_capable = 0;
2376                 goto clean_up;
2377         }
2378 
2379         /* Walk list of transports, removing transports in the UNKNOWN state. */
2380         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2381                 transport = list_entry(pos, struct sctp_transport, transports);
2382                 if (transport->state == SCTP_UNKNOWN) {
2383                         sctp_assoc_rm_peer(asoc, transport);
2384                 }
2385         }
2386 
2387         /* The fixed INIT headers are always in network byte
2388          * order.
2389          */
2390         asoc->peer.i.init_tag =
2391                 ntohl(peer_init->init_hdr.init_tag);
2392         asoc->peer.i.a_rwnd =
2393                 ntohl(peer_init->init_hdr.a_rwnd);
2394         asoc->peer.i.num_outbound_streams =
2395                 ntohs(peer_init->init_hdr.num_outbound_streams);
2396         asoc->peer.i.num_inbound_streams =
2397                 ntohs(peer_init->init_hdr.num_inbound_streams);
2398         asoc->peer.i.initial_tsn =
2399                 ntohl(peer_init->init_hdr.initial_tsn);
2400 
2401         asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2402 
2403         /* Apply the upper bounds for output streams based on peer's
2404          * number of inbound streams.
2405          */
2406         if (asoc->c.sinit_num_ostreams  >
2407             ntohs(peer_init->init_hdr.num_inbound_streams)) {
2408                 asoc->c.sinit_num_ostreams =
2409                         ntohs(peer_init->init_hdr.num_inbound_streams);
2410         }
2411 
2412         if (asoc->c.sinit_max_instreams >
2413             ntohs(peer_init->init_hdr.num_outbound_streams)) {
2414                 asoc->c.sinit_max_instreams =
2415                         ntohs(peer_init->init_hdr.num_outbound_streams);
2416         }
2417 
2418         /* Copy Initiation tag from INIT to VT_peer in cookie.   */
2419         asoc->c.peer_vtag = asoc->peer.i.init_tag;
2420 
2421         /* Peer Rwnd   : Current calculated value of the peer's rwnd.  */
2422         asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2423 
2424         /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2425          * high (for example, implementations MAY use the size of the receiver
2426          * advertised window).
2427          */
2428         list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2429                         transports) {
2430                 transport->ssthresh = asoc->peer.i.a_rwnd;
2431         }
2432 
2433         /* Set up the TSN tracking pieces.  */
2434         if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2435                                 asoc->peer.i.initial_tsn, gfp))
2436                 goto clean_up;
2437 
2438         /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2439          *
2440          * The stream sequence number in all the streams shall start
2441          * from 0 when the association is established.  Also, when the
2442          * stream sequence number reaches the value 65535 the next
2443          * stream sequence number shall be set to 0.
2444          */
2445 
2446         if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2447                              asoc->c.sinit_max_instreams, gfp))
2448                 goto clean_up;
2449 
2450         /* Update frag_point when stream_interleave may get changed. */
2451         sctp_assoc_update_frag_point(asoc);
2452 
2453         if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2454                 goto clean_up;
2455 
2456         /* ADDIP Section 4.1 ASCONF Chunk Procedures
2457          *
2458          * When an endpoint has an ASCONF signaled change to be sent to the
2459          * remote endpoint it should do the following:
2460          * ...
2461          * A2) A serial number should be assigned to the Chunk. The serial
2462          * number should be a monotonically increasing number. All serial
2463          * numbers are defined to be initialized at the start of the
2464          * association to the same value as the Initial TSN.
2465          */
2466         asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2467         return 1;
2468 
2469 clean_up:
2470         /* Release the transport structures. */
2471         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2472                 transport = list_entry(pos, struct sctp_transport, transports);
2473                 if (transport->state != SCTP_ACTIVE)
2474                         sctp_assoc_rm_peer(asoc, transport);
2475         }
2476 
2477 nomem:
2478         return 0;
2479 }
2480 
2481 
2482 /* Update asoc with the option described in param.
2483  *
2484  * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2485  *
2486  * asoc is the association to update.
2487  * param is the variable length parameter to use for update.
2488  * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2489  * If the current packet is an INIT we want to minimize the amount of
2490  * work we do.  In particular, we should not build transport
2491  * structures for the addresses.
2492  */
2493 static int sctp_process_param(struct sctp_association *asoc,
2494                               union sctp_params param,
2495                               const union sctp_addr *peer_addr,
2496                               gfp_t gfp)
2497 {
2498         struct net *net = sock_net(asoc->base.sk);
2499         struct sctp_endpoint *ep = asoc->ep;
2500         union sctp_addr_param *addr_param;
2501         struct sctp_transport *t;
2502         enum sctp_scope scope;
2503         union sctp_addr addr;
2504         struct sctp_af *af;
2505         int retval = 1, i;
2506         u32 stale;
2507         __u16 sat;
2508 
2509         /* We maintain all INIT parameters in network byte order all the
2510          * time.  This allows us to not worry about whether the parameters
2511          * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2512          */
2513         switch (param.p->type) {
2514         case SCTP_PARAM_IPV6_ADDRESS:
2515                 if (PF_INET6 != asoc->base.sk->sk_family)
2516                         break;
2517                 goto do_addr_param;
2518 
2519         case SCTP_PARAM_IPV4_ADDRESS:
2520                 /* v4 addresses are not allowed on v6-only socket */
2521                 if (ipv6_only_sock(asoc->base.sk))
2522                         break;
2523 do_addr_param:
2524                 af = sctp_get_af_specific(param_type2af(param.p->type));
2525                 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2526                 scope = sctp_scope(peer_addr);
2527                 if (sctp_in_scope(net, &addr, scope))
2528                         if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2529                                 return 0;
2530                 break;
2531 
2532         case SCTP_PARAM_COOKIE_PRESERVATIVE:
2533                 if (!net->sctp.cookie_preserve_enable)
2534                         break;
2535 
2536                 stale = ntohl(param.life->lifespan_increment);
2537 
2538                 /* Suggested Cookie Life span increment's unit is msec,
2539                  * (1/1000sec).
2540                  */
2541                 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2542                 break;
2543 
2544         case SCTP_PARAM_HOST_NAME_ADDRESS:
2545                 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2546                 break;
2547 
2548         case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2549                 /* Turn off the default values first so we'll know which
2550                  * ones are really set by the peer.
2551                  */
2552                 asoc->peer.ipv4_address = 0;
2553                 asoc->peer.ipv6_address = 0;
2554 
2555                 /* Assume that peer supports the address family
2556                  * by which it sends a packet.
2557                  */
2558                 if (peer_addr->sa.sa_family == AF_INET6)
2559                         asoc->peer.ipv6_address = 1;
2560                 else if (peer_addr->sa.sa_family == AF_INET)
2561                         asoc->peer.ipv4_address = 1;
2562 
2563                 /* Cycle through address types; avoid divide by 0. */
2564                 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2565                 if (sat)
2566                         sat /= sizeof(__u16);
2567 
2568                 for (i = 0; i < sat; ++i) {
2569                         switch (param.sat->types[i]) {
2570                         case SCTP_PARAM_IPV4_ADDRESS:
2571                                 asoc->peer.ipv4_address = 1;
2572                                 break;
2573 
2574                         case SCTP_PARAM_IPV6_ADDRESS:
2575                                 if (PF_INET6 == asoc->base.sk->sk_family)
2576                                         asoc->peer.ipv6_address = 1;
2577                                 break;
2578 
2579                         case SCTP_PARAM_HOST_NAME_ADDRESS:
2580                                 asoc->peer.hostname_address = 1;
2581                                 break;
2582 
2583                         default: /* Just ignore anything else.  */
2584                                 break;
2585                         }
2586                 }
2587                 break;
2588 
2589         case SCTP_PARAM_STATE_COOKIE:
2590                 asoc->peer.cookie_len =
2591                         ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2592                 kfree(asoc->peer.cookie);
2593                 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
2594                 if (!asoc->peer.cookie)
2595                         retval = 0;
2596                 break;
2597 
2598         case SCTP_PARAM_HEARTBEAT_INFO:
2599                 /* Would be odd to receive, but it causes no problems. */
2600                 break;
2601 
2602         case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2603                 /* Rejected during verify stage. */
2604                 break;
2605 
2606         case SCTP_PARAM_ECN_CAPABLE:
2607                 if (asoc->ep->ecn_enable) {
2608                         asoc->peer.ecn_capable = 1;
2609                         break;
2610                 }
2611                 /* Fall Through */
2612                 goto fall_through;
2613 
2614 
2615         case SCTP_PARAM_ADAPTATION_LAYER_IND:
2616                 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2617                 break;
2618 
2619         case SCTP_PARAM_SET_PRIMARY:
2620                 if (!ep->asconf_enable)
2621                         goto fall_through;
2622 
2623                 addr_param = param.v + sizeof(struct sctp_addip_param);
2624 
2625                 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2626                 if (af == NULL)
2627                         break;
2628 
2629                 af->from_addr_param(&addr, addr_param,
2630                                     htons(asoc->peer.port), 0);
2631 
2632                 /* if the address is invalid, we can't process it.
2633                  * XXX: see spec for what to do.
2634                  */
2635                 if (!af->addr_valid(&addr, NULL, NULL))
2636                         break;
2637 
2638                 t = sctp_assoc_lookup_paddr(asoc, &addr);
2639                 if (!t)
2640                         break;
2641 
2642                 sctp_assoc_set_primary(asoc, t);
2643                 break;
2644 
2645         case SCTP_PARAM_SUPPORTED_EXT:
2646                 sctp_process_ext_param(asoc, param);
2647                 break;
2648 
2649         case SCTP_PARAM_FWD_TSN_SUPPORT:
2650                 if (asoc->ep->prsctp_enable) {
2651                         asoc->peer.prsctp_capable = 1;
2652                         break;
2653                 }
2654                 /* Fall Through */
2655                 goto fall_through;
2656 
2657         case SCTP_PARAM_RANDOM:
2658                 if (!ep->auth_enable)
2659                         goto fall_through;
2660 
2661                 /* Save peer's random parameter */
2662                 kfree(asoc->peer.peer_random);
2663                 asoc->peer.peer_random = kmemdup(param.p,
2664                                             ntohs(param.p->length), gfp);
2665                 if (!asoc->peer.peer_random) {
2666                         retval = 0;
2667                         break;
2668                 }
2669                 break;
2670 
2671         case SCTP_PARAM_HMAC_ALGO:
2672                 if (!ep->auth_enable)
2673                         goto fall_through;
2674 
2675                 /* Save peer's HMAC list */
2676                 kfree(asoc->peer.peer_hmacs);
2677                 asoc->peer.peer_hmacs = kmemdup(param.p,
2678                                             ntohs(param.p->length), gfp);
2679                 if (!asoc->peer.peer_hmacs) {
2680                         retval = 0;
2681                         break;
2682                 }
2683 
2684                 /* Set the default HMAC the peer requested*/
2685                 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2686                 break;
2687 
2688         case SCTP_PARAM_CHUNKS:
2689                 if (!ep->auth_enable)
2690                         goto fall_through;
2691 
2692                 kfree(asoc->peer.peer_chunks);
2693                 asoc->peer.peer_chunks = kmemdup(param.p,
2694                                             ntohs(param.p->length), gfp);
2695                 if (!asoc->peer.peer_chunks)
2696                         retval = 0;
2697                 break;
2698 fall_through:
2699         default:
2700                 /* Any unrecognized parameters should have been caught
2701                  * and handled by sctp_verify_param() which should be
2702                  * called prior to this routine.  Simply log the error
2703                  * here.
2704                  */
2705                 pr_debug("%s: ignoring param:%d for association:%p.\n",
2706                          __func__, ntohs(param.p->type), asoc);
2707                 break;
2708         }
2709 
2710         return retval;
2711 }
2712 
2713 /* Select a new verification tag.  */
2714 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2715 {
2716         /* I believe that this random number generator complies with RFC1750.
2717          * A tag of 0 is reserved for special cases (e.g. INIT).
2718          */
2719         __u32 x;
2720 
2721         do {
2722                 get_random_bytes(&x, sizeof(__u32));
2723         } while (x == 0);
2724 
2725         return x;
2726 }
2727 
2728 /* Select an initial TSN to send during startup.  */
2729 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2730 {
2731         __u32 retval;
2732 
2733         get_random_bytes(&retval, sizeof(__u32));
2734         return retval;
2735 }
2736 
2737 /*
2738  * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2739  *      0                   1                   2                   3
2740  *      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
2741  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2742  *     | Type = 0xC1   |  Chunk Flags  |      Chunk Length             |
2743  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2744  *     |                       Serial Number                           |
2745  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2746  *     |                    Address Parameter                          |
2747  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2748  *     |                     ASCONF Parameter #1                       |
2749  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2750  *     \                                                               \
2751  *     /                             ....                              /
2752  *     \                                                               \
2753  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2754  *     |                     ASCONF Parameter #N                       |
2755  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2756  *
2757  * Address Parameter and other parameter will not be wrapped in this function
2758  */
2759 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2760                                            union sctp_addr *addr,
2761                                            int vparam_len)
2762 {
2763         struct sctp_addiphdr asconf;
2764         struct sctp_chunk *retval;
2765         int length = sizeof(asconf) + vparam_len;
2766         union sctp_addr_param addrparam;
2767         int addrlen;
2768         struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2769 
2770         addrlen = af->to_addr_param(addr, &addrparam);
2771         if (!addrlen)
2772                 return NULL;
2773         length += addrlen;
2774 
2775         /* Create the chunk.  */
2776         retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2777                                    GFP_ATOMIC);
2778         if (!retval)
2779                 return NULL;
2780 
2781         asconf.serial = htonl(asoc->addip_serial++);
2782 
2783         retval->subh.addip_hdr =
2784                 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2785         retval->param_hdr.v =
2786                 sctp_addto_chunk(retval, addrlen, &addrparam);
2787 
2788         return retval;
2789 }
2790 
2791 /* ADDIP
2792  * 3.2.1 Add IP Address
2793  *      0                   1                   2                   3
2794  *      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
2795  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2796  *     |        Type = 0xC001          |    Length = Variable          |
2797  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2798  *     |               ASCONF-Request Correlation ID                   |
2799  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2800  *     |                       Address Parameter                       |
2801  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2802  *
2803  * 3.2.2 Delete IP Address
2804  *      0                   1                   2                   3
2805  *      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
2806  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2807  *     |        Type = 0xC002          |    Length = Variable          |
2808  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2809  *     |               ASCONF-Request Correlation ID                   |
2810  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2811  *     |                       Address Parameter                       |
2812  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2813  *
2814  */
2815 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2816                                               union sctp_addr *laddr,
2817                                               struct sockaddr *addrs,
2818                                               int addrcnt, __be16 flags)
2819 {
2820         union sctp_addr_param addr_param;
2821         struct sctp_addip_param param;
2822         int paramlen = sizeof(param);
2823         struct sctp_chunk *retval;
2824         int addr_param_len = 0;
2825         union sctp_addr *addr;
2826         int totallen = 0, i;
2827         int del_pickup = 0;
2828         struct sctp_af *af;
2829         void *addr_buf;
2830 
2831         /* Get total length of all the address parameters. */
2832         addr_buf = addrs;
2833         for (i = 0; i < addrcnt; i++) {
2834                 addr = addr_buf;
2835                 af = sctp_get_af_specific(addr->v4.sin_family);
2836                 addr_param_len = af->to_addr_param(addr, &addr_param);
2837 
2838                 totallen += paramlen;
2839                 totallen += addr_param_len;
2840 
2841                 addr_buf += af->sockaddr_len;
2842                 if (asoc->asconf_addr_del_pending && !del_pickup) {
2843                         /* reuse the parameter length from the same scope one */
2844                         totallen += paramlen;
2845                         totallen += addr_param_len;
2846                         del_pickup = 1;
2847 
2848                         pr_debug("%s: picked same-scope del_pending addr, "
2849                                  "totallen for all addresses is %d\n",
2850                                  __func__, totallen);
2851                 }
2852         }
2853 
2854         /* Create an asconf chunk with the required length. */
2855         retval = sctp_make_asconf(asoc, laddr, totallen);
2856         if (!retval)
2857                 return NULL;
2858 
2859         /* Add the address parameters to the asconf chunk. */
2860         addr_buf = addrs;
2861         for (i = 0; i < addrcnt; i++) {
2862                 addr = addr_buf;
2863                 af = sctp_get_af_specific(addr->v4.sin_family);
2864                 addr_param_len = af->to_addr_param(addr, &addr_param);
2865                 param.param_hdr.type = flags;
2866                 param.param_hdr.length = htons(paramlen + addr_param_len);
2867                 param.crr_id = htonl(i);
2868 
2869                 sctp_addto_chunk(retval, paramlen, &param);
2870                 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2871 
2872                 addr_buf += af->sockaddr_len;
2873         }
2874         if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2875                 addr = asoc->asconf_addr_del_pending;
2876                 af = sctp_get_af_specific(addr->v4.sin_family);
2877                 addr_param_len = af->to_addr_param(addr, &addr_param);
2878                 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2879                 param.param_hdr.length = htons(paramlen + addr_param_len);
2880                 param.crr_id = htonl(i);
2881 
2882                 sctp_addto_chunk(retval, paramlen, &param);
2883                 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2884         }
2885         return retval;
2886 }
2887 
2888 /* ADDIP
2889  * 3.2.4 Set Primary IP Address
2890  *      0                   1                   2                   3
2891  *      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
2892  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2893  *     |        Type =0xC004           |    Length = Variable          |
2894  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2895  *     |               ASCONF-Request Correlation ID                   |
2896  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2897  *     |                       Address Parameter                       |
2898  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2899  *
2900  * Create an ASCONF chunk with Set Primary IP address parameter.
2901  */
2902 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2903                                              union sctp_addr *addr)
2904 {
2905         struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2906         union sctp_addr_param addrparam;
2907         struct sctp_addip_param param;
2908         struct sctp_chunk *retval;
2909         int len = sizeof(param);
2910         int addrlen;
2911 
2912         addrlen = af->to_addr_param(addr, &addrparam);
2913         if (!addrlen)
2914                 return NULL;
2915         len += addrlen;
2916 
2917         /* Create the chunk and make asconf header. */
2918         retval = sctp_make_asconf(asoc, addr, len);
2919         if (!retval)
2920                 return NULL;
2921 
2922         param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2923         param.param_hdr.length = htons(len);
2924         param.crr_id = 0;
2925 
2926         sctp_addto_chunk(retval, sizeof(param), &param);
2927         sctp_addto_chunk(retval, addrlen, &addrparam);
2928 
2929         return retval;
2930 }
2931 
2932 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2933  *      0                   1                   2                   3
2934  *      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
2935  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2936  *     | Type = 0x80   |  Chunk Flags  |      Chunk Length             |
2937  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2938  *     |                       Serial Number                           |
2939  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2940  *     |                 ASCONF Parameter Response#1                   |
2941  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2942  *     \                                                               \
2943  *     /                             ....                              /
2944  *     \                                                               \
2945  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2946  *     |                 ASCONF Parameter Response#N                   |
2947  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2948  *
2949  * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2950  */
2951 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2952                                                __u32 serial, int vparam_len)
2953 {
2954         struct sctp_addiphdr asconf;
2955         struct sctp_chunk *retval;
2956         int length = sizeof(asconf) + vparam_len;
2957 
2958         /* Create the chunk.  */
2959         retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2960                                    GFP_ATOMIC);
2961         if (!retval)
2962                 return NULL;
2963 
2964         asconf.serial = htonl(serial);
2965 
2966         retval->subh.addip_hdr =
2967                 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2968 
2969         return retval;
2970 }
2971 
2972 /* Add response parameters to an ASCONF_ACK chunk. */
2973 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2974                                      __be16 err_code,
2975                                      struct sctp_addip_param *asconf_param)
2976 {
2977         struct sctp_addip_param ack_param;
2978         struct sctp_errhdr err_param;
2979         int asconf_param_len = 0;
2980         int err_param_len = 0;
2981         __be16 response_type;
2982 
2983         if (SCTP_ERROR_NO_ERROR == err_code) {
2984                 response_type = SCTP_PARAM_SUCCESS_REPORT;
2985         } else {
2986                 response_type = SCTP_PARAM_ERR_CAUSE;
2987                 err_param_len = sizeof(err_param);
2988                 if (asconf_param)
2989                         asconf_param_len =
2990                                  ntohs(asconf_param->param_hdr.length);
2991         }
2992 
2993         /* Add Success Indication or Error Cause Indication parameter. */
2994         ack_param.param_hdr.type = response_type;
2995         ack_param.param_hdr.length = htons(sizeof(ack_param) +
2996                                            err_param_len +
2997                                            asconf_param_len);
2998         ack_param.crr_id = crr_id;
2999         sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
3000 
3001         if (SCTP_ERROR_NO_ERROR == err_code)
3002                 return;
3003 
3004         /* Add Error Cause parameter. */
3005         err_param.cause = err_code;
3006         err_param.length = htons(err_param_len + asconf_param_len);
3007         sctp_addto_chunk(chunk, err_param_len, &err_param);
3008 
3009         /* Add the failed TLV copied from ASCONF chunk. */
3010         if (asconf_param)
3011                 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3012 }
3013 
3014 /* Process a asconf parameter. */
3015 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3016                                         struct sctp_chunk *asconf,
3017                                         struct sctp_addip_param *asconf_param)
3018 {
3019         union sctp_addr_param *addr_param;
3020         struct sctp_transport *peer;
3021         union sctp_addr addr;
3022         struct sctp_af *af;
3023 
3024         addr_param = (void *)asconf_param + sizeof(*asconf_param);
3025 
3026         if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3027             asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3028             asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3029                 return SCTP_ERROR_UNKNOWN_PARAM;
3030 
3031         switch (addr_param->p.type) {
3032         case SCTP_PARAM_IPV6_ADDRESS:
3033                 if (!asoc->peer.ipv6_address)
3034                         return SCTP_ERROR_DNS_FAILED;
3035                 break;
3036         case SCTP_PARAM_IPV4_ADDRESS:
3037                 if (!asoc->peer.ipv4_address)
3038                         return SCTP_ERROR_DNS_FAILED;
3039                 break;
3040         default:
3041                 return SCTP_ERROR_DNS_FAILED;
3042         }
3043 
3044         af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3045         if (unlikely(!af))
3046                 return SCTP_ERROR_DNS_FAILED;
3047 
3048         af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3049 
3050         /* ADDIP 4.2.1  This parameter MUST NOT contain a broadcast
3051          * or multicast address.
3052          * (note: wildcard is permitted and requires special handling so
3053          *  make sure we check for that)
3054          */
3055         if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3056                 return SCTP_ERROR_DNS_FAILED;
3057 
3058         switch (asconf_param->param_hdr.type) {
3059         case SCTP_PARAM_ADD_IP:
3060                 /* Section 4.2.1:
3061                  * If the address 0.0.0.0 or ::0 is provided, the source
3062                  * address of the packet MUST be added.
3063                  */
3064                 if (af->is_any(&addr))
3065                         memcpy(&addr, &asconf->source, sizeof(addr));
3066 
3067                 if (security_sctp_bind_connect(asoc->ep->base.sk,
3068                                                SCTP_PARAM_ADD_IP,
3069                                                (struct sockaddr *)&addr,
3070                                                af->sockaddr_len))
3071                         return SCTP_ERROR_REQ_REFUSED;
3072 
3073                 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3074                  * request and does not have the local resources to add this
3075                  * new address to the association, it MUST return an Error
3076                  * Cause TLV set to the new error code 'Operation Refused
3077                  * Due to Resource Shortage'.
3078                  */
3079 
3080                 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3081                 if (!peer)
3082                         return SCTP_ERROR_RSRC_LOW;
3083 
3084                 /* Start the heartbeat timer. */
3085                 sctp_transport_reset_hb_timer(peer);
3086                 asoc->new_transport = peer;
3087                 break;
3088         case SCTP_PARAM_DEL_IP:
3089                 /* ADDIP 4.3 D7) If a request is received to delete the
3090                  * last remaining IP address of a peer endpoint, the receiver
3091                  * MUST send an Error Cause TLV with the error cause set to the
3092                  * new error code 'Request to Delete Last Remaining IP Address'.
3093                  */
3094                 if (asoc->peer.transport_count == 1)
3095                         return SCTP_ERROR_DEL_LAST_IP;
3096 
3097                 /* ADDIP 4.3 D8) If a request is received to delete an IP
3098                  * address which is also the source address of the IP packet
3099                  * which contained the ASCONF chunk, the receiver MUST reject
3100                  * this request. To reject the request the receiver MUST send
3101                  * an Error Cause TLV set to the new error code 'Request to
3102                  * Delete Source IP Address'
3103                  */
3104                 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3105                         return SCTP_ERROR_DEL_SRC_IP;
3106 
3107                 /* Section 4.2.2
3108                  * If the address 0.0.0.0 or ::0 is provided, all
3109                  * addresses of the peer except the source address of the
3110                  * packet MUST be deleted.
3111                  */
3112                 if (af->is_any(&addr)) {
3113                         sctp_assoc_set_primary(asoc, asconf->transport);
3114                         sctp_assoc_del_nonprimary_peers(asoc,
3115                                                         asconf->transport);
3116                         return SCTP_ERROR_NO_ERROR;
3117                 }
3118 
3119                 /* If the address is not part of the association, the
3120                  * ASCONF-ACK with Error Cause Indication Parameter
3121                  * which including cause of Unresolvable Address should
3122                  * be sent.
3123                  */
3124                 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3125                 if (!peer)
3126                         return SCTP_ERROR_DNS_FAILED;
3127 
3128                 sctp_assoc_rm_peer(asoc, peer);
3129                 break;
3130         case SCTP_PARAM_SET_PRIMARY:
3131                 /* ADDIP Section 4.2.4
3132                  * If the address 0.0.0.0 or ::0 is provided, the receiver
3133                  * MAY mark the source address of the packet as its
3134                  * primary.
3135                  */
3136                 if (af->is_any(&addr))
3137                         memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3138 
3139                 if (security_sctp_bind_connect(asoc->ep->base.sk,
3140                                                SCTP_PARAM_SET_PRIMARY,
3141                                                (struct sockaddr *)&addr,
3142                                                af->sockaddr_len))
3143                         return SCTP_ERROR_REQ_REFUSED;
3144 
3145                 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3146                 if (!peer)
3147                         return SCTP_ERROR_DNS_FAILED;
3148 
3149                 sctp_assoc_set_primary(asoc, peer);
3150                 break;
3151         }
3152 
3153         return SCTP_ERROR_NO_ERROR;
3154 }
3155 
3156 /* Verify the ASCONF packet before we process it. */
3157 bool sctp_verify_asconf(const struct sctp_association *asoc,
3158                         struct sctp_chunk *chunk, bool addr_param_needed,
3159                         struct sctp_paramhdr **errp)
3160 {
3161         struct sctp_addip_chunk *addip;
3162         bool addr_param_seen = false;
3163         union sctp_params param;
3164 
3165         addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3166         sctp_walk_params(param, addip, addip_hdr.params) {
3167                 size_t length = ntohs(param.p->length);
3168 
3169                 *errp = param.p;
3170                 switch (param.p->type) {
3171                 case SCTP_PARAM_ERR_CAUSE:
3172                         break;
3173                 case SCTP_PARAM_IPV4_ADDRESS:
3174                         if (length != sizeof(struct sctp_ipv4addr_param))
3175                                 return false;
3176                         /* ensure there is only one addr param and it's in the
3177                          * beginning of addip_hdr params, or we reject it.
3178                          */
3179                         if (param.v != addip->addip_hdr.params)
3180                                 return false;
3181                         addr_param_seen = true;
3182                         break;
3183                 case SCTP_PARAM_IPV6_ADDRESS:
3184                         if (length != sizeof(struct sctp_ipv6addr_param))
3185                                 return false;
3186                         if (param.v != addip->addip_hdr.params)
3187                                 return false;
3188                         addr_param_seen = true;
3189                         break;
3190                 case SCTP_PARAM_ADD_IP:
3191                 case SCTP_PARAM_DEL_IP:
3192                 case SCTP_PARAM_SET_PRIMARY:
3193                         /* In ASCONF chunks, these need to be first. */
3194                         if (addr_param_needed && !addr_param_seen)
3195                                 return false;
3196                         length = ntohs(param.addip->param_hdr.length);
3197                         if (length < sizeof(struct sctp_addip_param) +
3198                                      sizeof(**errp))
3199                                 return false;
3200                         break;
3201                 case SCTP_PARAM_SUCCESS_REPORT:
3202                 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3203                         if (length != sizeof(struct sctp_addip_param))
3204                                 return false;
3205                         break;
3206                 default:
3207                         /* This is unkown to us, reject! */
3208                         return false;
3209                 }
3210         }
3211 
3212         /* Remaining sanity checks. */
3213         if (addr_param_needed && !addr_param_seen)
3214                 return false;
3215         if (!addr_param_needed && addr_param_seen)
3216                 return false;
3217         if (param.v != chunk->chunk_end)
3218                 return false;
3219 
3220         return true;
3221 }
3222 
3223 /* Process an incoming ASCONF chunk with the next expected serial no. and
3224  * return an ASCONF_ACK chunk to be sent in response.
3225  */
3226 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3227                                        struct sctp_chunk *asconf)
3228 {
3229         union sctp_addr_param *addr_param;
3230         struct sctp_addip_chunk *addip;
3231         struct sctp_chunk *asconf_ack;
3232         bool all_param_pass = true;
3233         struct sctp_addiphdr *hdr;
3234         int length = 0, chunk_len;
3235         union sctp_params param;
3236         __be16 err_code;
3237         __u32 serial;
3238 
3239         addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3240         chunk_len = ntohs(asconf->chunk_hdr->length) -
3241                     sizeof(struct sctp_chunkhdr);
3242         hdr = (struct sctp_addiphdr *)asconf->skb->data;
3243         serial = ntohl(hdr->serial);
3244 
3245         /* Skip the addiphdr and store a pointer to address parameter.  */
3246         length = sizeof(*hdr);
3247         addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3248         chunk_len -= length;
3249 
3250         /* Skip the address parameter and store a pointer to the first
3251          * asconf parameter.
3252          */
3253         length = ntohs(addr_param->p.length);
3254         chunk_len -= length;
3255 
3256         /* create an ASCONF_ACK chunk.
3257          * Based on the definitions of parameters, we know that the size of
3258          * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3259          * parameters.
3260          */
3261         asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3262         if (!asconf_ack)
3263                 goto done;
3264 
3265         /* Process the TLVs contained within the ASCONF chunk. */
3266         sctp_walk_params(param, addip, addip_hdr.params) {
3267                 /* Skip preceeding address parameters. */
3268                 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3269                     param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3270                         continue;
3271 
3272                 err_code = sctp_process_asconf_param(asoc, asconf,
3273                                                      param.addip);
3274                 /* ADDIP 4.1 A7)
3275                  * If an error response is received for a TLV parameter,
3276                  * all TLVs with no response before the failed TLV are
3277                  * considered successful if not reported.  All TLVs after
3278                  * the failed response are considered unsuccessful unless
3279                  * a specific success indication is present for the parameter.
3280                  */
3281                 if (err_code != SCTP_ERROR_NO_ERROR)
3282                         all_param_pass = false;
3283                 if (!all_param_pass)
3284                         sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3285                                                  err_code, param.addip);
3286 
3287                 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3288                  * an IP address sends an 'Out of Resource' in its response, it
3289                  * MUST also fail any subsequent add or delete requests bundled
3290                  * in the ASCONF.
3291                  */
3292                 if (err_code == SCTP_ERROR_RSRC_LOW)
3293                         goto done;
3294         }
3295 done:
3296         asoc->peer.addip_serial++;
3297 
3298         /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3299          * after freeing the reference to old asconf ack if any.
3300          */
3301         if (asconf_ack) {
3302                 sctp_chunk_hold(asconf_ack);
3303                 list_add_tail(&asconf_ack->transmitted_list,
3304                               &asoc->asconf_ack_list);
3305         }
3306 
3307         return asconf_ack;
3308 }
3309 
3310 /* Process a asconf parameter that is successfully acked. */
3311 static void sctp_asconf_param_success(struct sctp_association *asoc,
3312                                       struct sctp_addip_param *asconf_param)
3313 {
3314         struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3315         union sctp_addr_param *addr_param;
3316         struct sctp_sockaddr_entry *saddr;
3317         struct sctp_transport *transport;
3318         union sctp_addr addr;
3319         struct sctp_af *af;
3320 
3321         addr_param = (void *)asconf_param + sizeof(*asconf_param);
3322 
3323         /* We have checked the packet before, so we do not check again. */
3324         af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3325         af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3326 
3327         switch (asconf_param->param_hdr.type) {
3328         case SCTP_PARAM_ADD_IP:
3329                 /* This is always done in BH context with a socket lock
3330                  * held, so the list can not change.
3331                  */
3332                 local_bh_disable();
3333                 list_for_each_entry(saddr, &bp->address_list, list) {
3334                         if (sctp_cmp_addr_exact(&saddr->a, &addr))
3335                                 saddr->state = SCTP_ADDR_SRC;
3336                 }
3337                 local_bh_enable();
3338                 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3339                                 transports) {
3340                         sctp_transport_dst_release(transport);
3341                 }
3342                 break;
3343         case SCTP_PARAM_DEL_IP:
3344                 local_bh_disable();
3345                 sctp_del_bind_addr(bp, &addr);
3346                 if (asoc->asconf_addr_del_pending != NULL &&
3347                     sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3348                         kfree(asoc->asconf_addr_del_pending);
3349                         asoc->asconf_addr_del_pending = NULL;
3350                 }
3351                 local_bh_enable();
3352                 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3353                                 transports) {
3354                         sctp_transport_dst_release(transport);
3355                 }
3356                 break;
3357         default:
3358                 break;
3359         }
3360 }
3361 
3362 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3363  * for the given asconf parameter.  If there is no response for this parameter,
3364  * return the error code based on the third argument 'no_err'.
3365  * ADDIP 4.1
3366  * A7) If an error response is received for a TLV parameter, all TLVs with no
3367  * response before the failed TLV are considered successful if not reported.
3368  * All TLVs after the failed response are considered unsuccessful unless a
3369  * specific success indication is present for the parameter.
3370  */
3371 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3372                                        struct sctp_addip_param *asconf_param,
3373                                        int no_err)
3374 {
3375         struct sctp_addip_param *asconf_ack_param;
3376         struct sctp_errhdr *err_param;
3377         int asconf_ack_len;
3378         __be16 err_code;
3379         int length;
3380 
3381         if (no_err)
3382                 err_code = SCTP_ERROR_NO_ERROR;
3383         else
3384                 err_code = SCTP_ERROR_REQ_REFUSED;
3385 
3386         asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3387                          sizeof(struct sctp_chunkhdr);
3388 
3389         /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3390          * the first asconf_ack parameter.
3391          */
3392         length = sizeof(struct sctp_addiphdr);
3393         asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3394                                                        length);
3395         asconf_ack_len -= length;
3396 
3397         while (asconf_ack_len > 0) {
3398                 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3399                         switch (asconf_ack_param->param_hdr.type) {
3400                         case SCTP_PARAM_SUCCESS_REPORT:
3401                                 return SCTP_ERROR_NO_ERROR;
3402                         case SCTP_PARAM_ERR_CAUSE:
3403                                 length = sizeof(*asconf_ack_param);
3404                                 err_param = (void *)asconf_ack_param + length;
3405                                 asconf_ack_len -= length;
3406                                 if (asconf_ack_len > 0)
3407                                         return err_param->cause;
3408                                 else
3409                                         return SCTP_ERROR_INV_PARAM;
3410                                 break;
3411                         default:
3412                                 return SCTP_ERROR_INV_PARAM;
3413                         }
3414                 }
3415 
3416                 length = ntohs(asconf_ack_param->param_hdr.length);
3417                 asconf_ack_param = (void *)asconf_ack_param + length;
3418                 asconf_ack_len -= length;
3419         }
3420 
3421         return err_code;
3422 }
3423 
3424 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3425 int sctp_process_asconf_ack(struct sctp_association *asoc,
3426                             struct sctp_chunk *asconf_ack)
3427 {
3428         struct sctp_chunk *asconf = asoc->addip_last_asconf;
3429         struct sctp_addip_param *asconf_param;
3430         __be16 err_code = SCTP_ERROR_NO_ERROR;
3431         union sctp_addr_param *addr_param;
3432         int asconf_len = asconf->skb->len;
3433         int all_param_pass = 0;
3434         int length = 0;
3435         int no_err = 1;
3436         int retval = 0;
3437 
3438         /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3439          * a pointer to address parameter.
3440          */
3441         length = sizeof(struct sctp_addip_chunk);
3442         addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3443         asconf_len -= length;
3444 
3445         /* Skip the address parameter in the last asconf sent and store a
3446          * pointer to the first asconf parameter.
3447          */
3448         length = ntohs(addr_param->p.length);
3449         asconf_param = (void *)addr_param + length;
3450         asconf_len -= length;
3451 
3452         /* ADDIP 4.1
3453          * A8) If there is no response(s) to specific TLV parameter(s), and no
3454          * failures are indicated, then all request(s) are considered
3455          * successful.
3456          */
3457         if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3458                 all_param_pass = 1;
3459 
3460         /* Process the TLVs contained in the last sent ASCONF chunk. */
3461         while (asconf_len > 0) {
3462                 if (all_param_pass)
3463                         err_code = SCTP_ERROR_NO_ERROR;
3464                 else {
3465                         err_code = sctp_get_asconf_response(asconf_ack,
3466                                                             asconf_param,
3467                                                             no_err);
3468                         if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3469                                 no_err = 0;
3470                 }
3471 
3472                 switch (err_code) {
3473                 case SCTP_ERROR_NO_ERROR:
3474                         sctp_asconf_param_success(asoc, asconf_param);
3475                         break;
3476 
3477                 case SCTP_ERROR_RSRC_LOW:
3478                         retval = 1;
3479                         break;
3480 
3481                 case SCTP_ERROR_UNKNOWN_PARAM:
3482                         /* Disable sending this type of asconf parameter in
3483                          * future.
3484                          */
3485                         asoc->peer.addip_disabled_mask |=
3486                                 asconf_param->param_hdr.type;
3487                         break;
3488 
3489                 case SCTP_ERROR_REQ_REFUSED:
3490                 case SCTP_ERROR_DEL_LAST_IP:
3491                 case SCTP_ERROR_DEL_SRC_IP:
3492                 default:
3493                          break;
3494                 }
3495 
3496                 /* Skip the processed asconf parameter and move to the next
3497                  * one.
3498                  */
3499                 length = ntohs(asconf_param->param_hdr.length);
3500                 asconf_param = (void *)asconf_param + length;
3501                 asconf_len -= length;
3502         }
3503 
3504         if (no_err && asoc->src_out_of_asoc_ok) {
3505                 asoc->src_out_of_asoc_ok = 0;
3506                 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3507         }
3508 
3509         /* Free the cached last sent asconf chunk. */
3510         list_del_init(&asconf->transmitted_list);
3511         sctp_chunk_free(asconf);
3512         asoc->addip_last_asconf = NULL;
3513 
3514         return retval;
3515 }
3516 
3517 /* Make a FWD TSN chunk. */
3518 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3519                                     __u32 new_cum_tsn, size_t nstreams,
3520                                     struct sctp_fwdtsn_skip *skiplist)
3521 {
3522         struct sctp_chunk *retval = NULL;
3523         struct sctp_fwdtsn_hdr ftsn_hdr;
3524         struct sctp_fwdtsn_skip skip;
3525         size_t hint;
3526         int i;
3527 
3528         hint = (nstreams + 1) * sizeof(__u32);
3529 
3530         retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3531 
3532         if (!retval)
3533                 return NULL;
3534 
3535         ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3536         retval->subh.fwdtsn_hdr =
3537                 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3538 
3539         for (i = 0; i < nstreams; i++) {
3540                 skip.stream = skiplist[i].stream;
3541                 skip.ssn = skiplist[i].ssn;
3542                 sctp_addto_chunk(retval, sizeof(skip), &skip);
3543         }
3544 
3545         return retval;
3546 }
3547 
3548 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3549                                      __u32 new_cum_tsn, size_t nstreams,
3550                                      struct sctp_ifwdtsn_skip *skiplist)
3551 {
3552         struct sctp_chunk *retval = NULL;
3553         struct sctp_ifwdtsn_hdr ftsn_hdr;
3554         size_t hint;
3555 
3556         hint = (nstreams + 1) * sizeof(__u32);
3557 
3558         retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3559                                    GFP_ATOMIC);
3560         if (!retval)
3561                 return NULL;
3562 
3563         ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3564         retval->subh.ifwdtsn_hdr =
3565                 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3566 
3567         sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3568 
3569         return retval;
3570 }
3571 
3572 /* RE-CONFIG 3.1 (RE-CONFIG chunk)
3573  *   0                   1                   2                   3
3574  *   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
3575  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3576  *  | Type = 130    |  Chunk Flags  |      Chunk Length             |
3577  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3578  *  \                                                               \
3579  *  /                  Re-configuration Parameter                   /
3580  *  \                                                               \
3581  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3582  *  \                                                               \
3583  *  /             Re-configuration Parameter (optional)             /
3584  *  \                                                               \
3585  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3586  */
3587 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3588                                            int length)
3589 {
3590         struct sctp_reconf_chunk *reconf;
3591         struct sctp_chunk *retval;
3592 
3593         retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3594                                    GFP_ATOMIC);
3595         if (!retval)
3596                 return NULL;
3597 
3598         reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3599         retval->param_hdr.v = reconf->params;
3600 
3601         return retval;
3602 }
3603 
3604 /* RE-CONFIG 4.1 (STREAM OUT RESET)
3605  *   0                   1                   2                   3
3606  *   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
3607  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3608  *  |     Parameter Type = 13       | Parameter Length = 16 + 2 * N |
3609  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3610  *  |           Re-configuration Request Sequence Number            |
3611  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3612  *  |           Re-configuration Response Sequence Number           |
3613  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3614  *  |                Sender's Last Assigned TSN                     |
3615  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3616  *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
3617  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3618  *  /                            ......                             /
3619  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3620  *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
3621  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3622  *
3623  * RE-CONFIG 4.2 (STREAM IN RESET)
3624  *   0                   1                   2                   3
3625  *   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
3626  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3627  *  |     Parameter Type = 14       |  Parameter Length = 8 + 2 * N |
3628  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3629  *  |          Re-configuration Request Sequence Number             |
3630  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3631  *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
3632  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3633  *  /                            ......                             /
3634  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3635  *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
3636  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3637  */
3638 struct sctp_chunk *sctp_make_strreset_req(
3639                                         const struct sctp_association *asoc,
3640                                         __u16 stream_num, __be16 *stream_list,
3641                                         bool out, bool in)
3642 {
3643         __u16 stream_len = stream_num * sizeof(__u16);
3644         struct sctp_strreset_outreq outreq;
3645         struct sctp_strreset_inreq inreq;
3646         struct sctp_chunk *retval;
3647         __u16 outlen, inlen;
3648 
3649         outlen = (sizeof(outreq) + stream_len) * out;
3650         inlen = (sizeof(inreq) + stream_len) * in;
3651 
3652         retval = sctp_make_reconf(asoc, outlen + inlen);
3653         if (!retval)
3654                 return NULL;
3655 
3656         if (outlen) {
3657                 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3658                 outreq.param_hdr.length = htons(outlen);
3659                 outreq.request_seq = htonl(asoc->strreset_outseq);
3660                 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3661                 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3662 
3663                 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3664 
3665                 if (stream_len)
3666                         sctp_addto_chunk(retval, stream_len, stream_list);
3667         }
3668 
3669         if (inlen) {
3670                 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3671                 inreq.param_hdr.length = htons(inlen);
3672                 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3673 
3674                 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3675 
3676                 if (stream_len)
3677                         sctp_addto_chunk(retval, stream_len, stream_list);
3678         }
3679 
3680         return retval;
3681 }
3682 
3683 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3684  *   0                   1                   2                   3
3685  *   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
3686  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3687  *  |     Parameter Type = 15       |      Parameter Length = 8     |
3688  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3689  *  |         Re-configuration Request Sequence Number              |
3690  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3691  */
3692 struct sctp_chunk *sctp_make_strreset_tsnreq(
3693                                         const struct sctp_association *asoc)
3694 {
3695         struct sctp_strreset_tsnreq tsnreq;
3696         __u16 length = sizeof(tsnreq);
3697         struct sctp_chunk *retval;
3698 
3699         retval = sctp_make_reconf(asoc, length);
3700         if (!retval)
3701                 return NULL;
3702 
3703         tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3704         tsnreq.param_hdr.length = htons(length);
3705         tsnreq.request_seq = htonl(asoc->strreset_outseq);
3706 
3707         sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3708 
3709         return retval;
3710 }
3711 
3712 /* RE-CONFIG 4.5/4.6 (ADD STREAM)
3713  *   0                   1                   2                   3
3714  *   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
3715  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3716  *  |     Parameter Type = 17       |      Parameter Length = 12    |
3717  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3718  *  |          Re-configuration Request Sequence Number             |
3719  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3720  *  |      Number of new streams    |         Reserved              |
3721  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3722  */
3723 struct sctp_chunk *sctp_make_strreset_addstrm(
3724                                         const struct sctp_association *asoc,
3725                                         __u16 out, __u16 in)
3726 {
3727         struct sctp_strreset_addstrm addstrm;
3728         __u16 size = sizeof(addstrm);
3729         struct sctp_chunk *retval;
3730 
3731         retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3732         if (!retval)
3733                 return NULL;
3734 
3735         if (out) {
3736                 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3737                 addstrm.param_hdr.length = htons(size);
3738                 addstrm.number_of_streams = htons(out);
3739                 addstrm.request_seq = htonl(asoc->strreset_outseq);
3740                 addstrm.reserved = 0;
3741 
3742                 sctp_addto_chunk(retval, size, &addstrm);
3743         }
3744 
3745         if (in) {
3746                 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3747                 addstrm.param_hdr.length = htons(size);
3748                 addstrm.number_of_streams = htons(in);
3749                 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3750                 addstrm.reserved = 0;
3751 
3752                 sctp_addto_chunk(retval, size, &addstrm);
3753         }
3754 
3755         return retval;
3756 }
3757 
3758 /* RE-CONFIG 4.4 (RESP)
3759  *   0                   1                   2                   3
3760  *   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
3761  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3762  *  |     Parameter Type = 16       |      Parameter Length         |
3763  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3764  *  |         Re-configuration Response Sequence Number             |
3765  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3766  *  |                            Result                             |
3767  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3768  */
3769 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3770                                            __u32 result, __u32 sn)
3771 {
3772         struct sctp_strreset_resp resp;
3773         __u16 length = sizeof(resp);
3774         struct sctp_chunk *retval;
3775 
3776         retval = sctp_make_reconf(asoc, length);
3777         if (!retval)
3778                 return NULL;
3779 
3780         resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3781         resp.param_hdr.length = htons(length);
3782         resp.response_seq = htonl(sn);
3783         resp.result = htonl(result);
3784 
3785         sctp_addto_chunk(retval, sizeof(resp), &resp);
3786 
3787         return retval;
3788 }
3789 
3790 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3791  *   0                   1                   2                   3
3792  *   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
3793  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3794  *  |     Parameter Type = 16       |      Parameter Length         |
3795  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3796  *  |         Re-configuration Response Sequence Number             |
3797  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3798  *  |                            Result                             |
3799  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3800  *  |                   Sender's Next TSN (optional)                |
3801  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3802  *  |                  Receiver's Next TSN (optional)               |
3803  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3804  */
3805 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3806                                               __u32 result, __u32 sn,
3807                                               __u32 sender_tsn,
3808                                               __u32 receiver_tsn)
3809 {
3810         struct sctp_strreset_resptsn tsnresp;
3811         __u16 length = sizeof(tsnresp);
3812         struct sctp_chunk *retval;
3813 
3814         retval = sctp_make_reconf(asoc, length);
3815         if (!retval)
3816                 return NULL;
3817 
3818         tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3819         tsnresp.param_hdr.length = htons(length);
3820 
3821         tsnresp.response_seq = htonl(sn);
3822         tsnresp.result = htonl(result);
3823         tsnresp.senders_next_tsn = htonl(sender_tsn);
3824         tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3825 
3826         sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3827 
3828         return retval;
3829 }
3830 
3831 bool sctp_verify_reconf(const struct sctp_association *asoc,
3832                         struct sctp_chunk *chunk,
3833                         struct sctp_paramhdr **errp)
3834 {
3835         struct sctp_reconf_chunk *hdr;
3836         union sctp_params param;
3837         __be16 last = 0;
3838         __u16 cnt = 0;
3839 
3840         hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3841         sctp_walk_params(param, hdr, params) {
3842                 __u16 length = ntohs(param.p->length);
3843 
3844                 *errp = param.p;
3845                 if (cnt++ > 2)
3846                         return false;
3847                 switch (param.p->type) {
3848                 case SCTP_PARAM_RESET_OUT_REQUEST:
3849                         if (length < sizeof(struct sctp_strreset_outreq) ||
3850                             (last && last != SCTP_PARAM_RESET_RESPONSE &&
3851                              last != SCTP_PARAM_RESET_IN_REQUEST))
3852                                 return false;
3853                         break;
3854                 case SCTP_PARAM_RESET_IN_REQUEST:
3855                         if (length < sizeof(struct sctp_strreset_inreq) ||
3856                             (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3857                                 return false;
3858                         break;
3859                 case SCTP_PARAM_RESET_RESPONSE:
3860                         if ((length != sizeof(struct sctp_strreset_resp) &&
3861                              length != sizeof(struct sctp_strreset_resptsn)) ||
3862                             (last && last != SCTP_PARAM_RESET_RESPONSE &&
3863                              last != SCTP_PARAM_RESET_OUT_REQUEST))
3864                                 return false;
3865                         break;
3866                 case SCTP_PARAM_RESET_TSN_REQUEST:
3867                         if (length !=
3868                             sizeof(struct sctp_strreset_tsnreq) || last)
3869                                 return false;
3870                         break;
3871                 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3872                         if (length != sizeof(struct sctp_strreset_addstrm) ||
3873                             (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3874                                 return false;
3875                         break;
3876                 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3877                         if (length != sizeof(struct sctp_strreset_addstrm) ||
3878                             (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3879                                 return false;
3880                         break;
3881                 default:
3882                         return false;
3883                 }
3884 
3885                 last = param.p->type;
3886         }
3887 
3888         return true;
3889 }
/* [<][>][^][v][top][bottom][index][help] */
root/net/sctp/sm_make_chunk.c

DEFINITIONS
