include/linux/sctp.h

   1 /* SCTP kernel reference Implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999-2000 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  * Copyright (c) 2001 Intel Corp.
   6  * Copyright (c) 2001 Nokia, Inc.
   7  * Copyright (c) 2001 La Monte H.P. Yarroll
   8  *
   9  * This file is part of the SCTP kernel reference Implementation
  10  *
  11  * Various protocol defined structures.
  12  *
  13  * This SCTP implementation is free software;
  14  * you can redistribute it and/or modify it under the terms of
  15  * the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  * This SCTP implementation is distributed in the hope that it
  20  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  21  *                 ************************
  22  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  23  * See the GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with GNU CC; see the file COPYING.  If not, write to
  27  * the Free Software Foundation, 59 Temple Place - Suite 330,
  28  * Boston, MA 02111-1307, USA.
  29  *
  30  * Please send any bug reports or fixes you make to the
  31  * email address(es):
  32  *    lksctp developers <lksctp-developerst@lists.sourceforge.net>
  33  *
  34  * Or submit a bug report through the following website:
  35  *    http://www.sf.net/projects/lksctp
  36  *
  37  * Written or modified by:
  38  *    La Monte H.P. Yarroll <piggy@acm.org>
  39  *    Karl Knutson <karl@athena.chicago.il.us>
  40  *    Jon Grimm <jgrimm@us.ibm.com>
  41  *    Xingang Guo <xingang.guo@intel.com>
  42  *    randall@sctp.chicago.il.us
  43  *    kmorneau@cisco.com
  44  *    qxie1@email.mot.com
  45  *    Sridhar Samudrala <sri@us.ibm.com>
  46  *    Kevin Gao <kevin.gao@intel.com>
  47  *
  48  * Any bugs reported given to us we will try to fix... any fixes shared will
  49  * be incorporated into the next SCTP release.
  50  */
  51 #ifndef __LINUX_SCTP_H__
  52 #define __LINUX_SCTP_H__
  53
  54 #include <linux/in.h>           /* We need in_addr.  */
  55 #include <linux/in6.h>          /* We need in6_addr.  */
  56 #include <linux/skbuff.h>
  57
  58 #include <uapi/linux/sctp.h>
  59
  60 /* Section 3.1.  SCTP Common Header Format */
  61 typedef struct sctphdr {
  62         __be16 source;
  63         __be16 dest;
  64         __be32 vtag;
  65         __le32 checksum;
  66 } __packed sctp_sctphdr_t;
  67
  68 static inline struct sctphdr *sctp_hdr(const struct sk_buff *skb)
  69 {
  70         return (struct sctphdr *)skb_transport_header(skb);
  71 }
  72
  73 /* Section 3.2.  Chunk Field Descriptions. */
  74 typedef struct sctp_chunkhdr {
  75         __u8 type;
  76         __u8 flags;
  77         __be16 length;
  78 } __packed sctp_chunkhdr_t;
  79
  80
  81 /* Section 3.2.  Chunk Type Values.
  82  * [Chunk Type] identifies the type of information contained in the Chunk
  83  * Value field. It takes a value from 0 to 254. The value of 255 is
  84  * reserved for future use as an extension field.
  85  */
  86 typedef enum {
  87         SCTP_CID_DATA                   = 0,
  88         SCTP_CID_INIT                   = 1,
  89         SCTP_CID_INIT_ACK               = 2,
  90         SCTP_CID_SACK                   = 3,
  91         SCTP_CID_HEARTBEAT              = 4,
  92         SCTP_CID_HEARTBEAT_ACK          = 5,
  93         SCTP_CID_ABORT                  = 6,
  94         SCTP_CID_SHUTDOWN               = 7,
  95         SCTP_CID_SHUTDOWN_ACK           = 8,
  96         SCTP_CID_ERROR                  = 9,
  97         SCTP_CID_COOKIE_ECHO            = 10,
  98         SCTP_CID_COOKIE_ACK             = 11,
  99         SCTP_CID_ECN_ECNE               = 12,
 100         SCTP_CID_ECN_CWR                = 13,
 101         SCTP_CID_SHUTDOWN_COMPLETE      = 14,
 102
 103         /* AUTH Extension Section 4.1 */
 104         SCTP_CID_AUTH                   = 0x0F,
 105
 106         /* PR-SCTP Sec 3.2 */
 107         SCTP_CID_FWD_TSN                = 0xC0,
 108
 109         /* Use hex, as defined in ADDIP sec. 3.1 */
 110         SCTP_CID_ASCONF                 = 0xC1,
 111         SCTP_CID_ASCONF_ACK             = 0x80,
 112 } sctp_cid_t; /* enum */
 113
 114
 115 /* Section 3.2
 116  *  Chunk Types are encoded such that the highest-order two bits specify
 117  *  the action that must be taken if the processing endpoint does not
 118  *  recognize the Chunk Type.
 119  */
 120 typedef enum {
 121         SCTP_CID_ACTION_DISCARD     = 0x00,
 122         SCTP_CID_ACTION_DISCARD_ERR = 0x40,
 123         SCTP_CID_ACTION_SKIP        = 0x80,
 124         SCTP_CID_ACTION_SKIP_ERR    = 0xc0,
 125 } sctp_cid_action_t;
 126
 127 enum { SCTP_CID_ACTION_MASK = 0xc0, };
 128
 129 /* This flag is used in Chunk Flags for ABORT and SHUTDOWN COMPLETE.
 130  *
 131  * 3.3.7 Abort Association (ABORT) (6):
 132  *    The T bit is set to 0 if the sender had a TCB that it destroyed.
 133  *    If the sender did not have a TCB it should set this bit to 1.
 134  */
 135 enum { SCTP_CHUNK_FLAG_T = 0x01 };
 136
 137 /*
 138  *  Set the T bit
 139  *
 140  *      0                   1                   2                   3
 141  *      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
 142  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 143  *     |   Type = 14   |Reserved     |T|      Length = 4               |
 144  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 145  *
 146  * Chunk Flags: 8 bits
 147  *
 148  *   Reserved:  7 bits
 149  *     Set to 0 on transmit and ignored on receipt.
 150  *
 151  *   T bit:  1 bit
 152  *     The T bit is set to 0 if the sender had a TCB that it destroyed. If
 153  *     the sender did NOT have a TCB it should set this bit to 1.
 154  *
 155  * Note: Special rules apply to this chunk for verification, please
 156  * see Section 8.5.1 for details.
 157  */
 158
 159 #define sctp_test_T_bit(c)    ((c)->chunk_hdr->flags & SCTP_CHUNK_FLAG_T)
 160
 161 /* RFC 2960
 162  * Section 3.2.1 Optional/Variable-length Parmaeter Format.
 163  */
 164
 165 typedef struct sctp_paramhdr {
 166         __be16 type;
 167         __be16 length;
 168 } __packed sctp_paramhdr_t;
 169
 170 typedef enum {
 171
 172         /* RFC 2960 Section 3.3.5 */
 173         SCTP_PARAM_HEARTBEAT_INFO               = cpu_to_be16(1),
 174         /* RFC 2960 Section 3.3.2.1 */
 175         SCTP_PARAM_IPV4_ADDRESS                 = cpu_to_be16(5),
 176         SCTP_PARAM_IPV6_ADDRESS                 = cpu_to_be16(6),
 177         SCTP_PARAM_STATE_COOKIE                 = cpu_to_be16(7),
 178         SCTP_PARAM_UNRECOGNIZED_PARAMETERS      = cpu_to_be16(8),
 179         SCTP_PARAM_COOKIE_PRESERVATIVE          = cpu_to_be16(9),
 180         SCTP_PARAM_HOST_NAME_ADDRESS            = cpu_to_be16(11),
 181         SCTP_PARAM_SUPPORTED_ADDRESS_TYPES      = cpu_to_be16(12),
 182         SCTP_PARAM_ECN_CAPABLE                  = cpu_to_be16(0x8000),
 183
 184         /* AUTH Extension Section 3 */
 185         SCTP_PARAM_RANDOM                       = cpu_to_be16(0x8002),
 186         SCTP_PARAM_CHUNKS                       = cpu_to_be16(0x8003),
 187         SCTP_PARAM_HMAC_ALGO                    = cpu_to_be16(0x8004),
 188
 189         /* Add-IP: Supported Extensions, Section 4.2 */
 190         SCTP_PARAM_SUPPORTED_EXT        = cpu_to_be16(0x8008),
 191
 192         /* PR-SCTP Sec 3.1 */
 193         SCTP_PARAM_FWD_TSN_SUPPORT      = cpu_to_be16(0xc000),
 194
 195         /* Add-IP Extension. Section 3.2 */
 196         SCTP_PARAM_ADD_IP               = cpu_to_be16(0xc001),
 197         SCTP_PARAM_DEL_IP               = cpu_to_be16(0xc002),
 198         SCTP_PARAM_ERR_CAUSE            = cpu_to_be16(0xc003),
 199         SCTP_PARAM_SET_PRIMARY          = cpu_to_be16(0xc004),
 200         SCTP_PARAM_SUCCESS_REPORT       = cpu_to_be16(0xc005),
 201         SCTP_PARAM_ADAPTATION_LAYER_IND = cpu_to_be16(0xc006),
 202
 203 } sctp_param_t; /* enum */
 204
 205
 206 /* RFC 2960 Section 3.2.1
 207  *  The Parameter Types are encoded such that the highest-order two bits
 208  *  specify the action that must be taken if the processing endpoint does
 209  *  not recognize the Parameter Type.
 210  *
 211  */
 212 typedef enum {
 213         SCTP_PARAM_ACTION_DISCARD     = cpu_to_be16(0x0000),
 214         SCTP_PARAM_ACTION_DISCARD_ERR = cpu_to_be16(0x4000),
 215         SCTP_PARAM_ACTION_SKIP        = cpu_to_be16(0x8000),
 216         SCTP_PARAM_ACTION_SKIP_ERR    = cpu_to_be16(0xc000),
 217 } sctp_param_action_t;
 218
 219 enum { SCTP_PARAM_ACTION_MASK = cpu_to_be16(0xc000), };
 220
 221 /* RFC 2960 Section 3.3.1 Payload Data (DATA) (0) */
 222
 223 typedef struct sctp_datahdr {
 224         __be32 tsn;
 225         __be16 stream;
 226         __be16 ssn;
 227         __be32 ppid;
 228         __u8  payload[0];
 229 } __packed sctp_datahdr_t;
 230
 231 typedef struct sctp_data_chunk {
 232         sctp_chunkhdr_t chunk_hdr;
 233         sctp_datahdr_t  data_hdr;
 234 } __packed sctp_data_chunk_t;
 235
 236 /* DATA Chuck Specific Flags */
 237 enum {
 238         SCTP_DATA_MIDDLE_FRAG   = 0x00,
 239         SCTP_DATA_LAST_FRAG     = 0x01,
 240         SCTP_DATA_FIRST_FRAG    = 0x02,
 241         SCTP_DATA_NOT_FRAG      = 0x03,
 242         SCTP_DATA_UNORDERED     = 0x04,
 243         SCTP_DATA_SACK_IMM      = 0x08,
 244 };
 245 enum { SCTP_DATA_FRAG_MASK = 0x03, };
 246
 247
 248 /* RFC 2960 Section 3.3.2 Initiation (INIT) (1)
 249  *
 250  *  This chunk is used to initiate a SCTP association between two
 251  *  endpoints.
 252  */
 253 typedef struct sctp_inithdr {
 254         __be32 init_tag;
 255         __be32 a_rwnd;
 256         __be16 num_outbound_streams;
 257         __be16 num_inbound_streams;
 258         __be32 initial_tsn;
 259         __u8  params[0];
 260 } __packed sctp_inithdr_t;
 261
 262 typedef struct sctp_init_chunk {
 263         sctp_chunkhdr_t chunk_hdr;
 264         sctp_inithdr_t init_hdr;
 265 } __packed sctp_init_chunk_t;
 266
 267
 268 /* Section 3.3.2.1. IPv4 Address Parameter (5) */
 269 typedef struct sctp_ipv4addr_param {
 270         sctp_paramhdr_t param_hdr;
 271         struct in_addr  addr;
 272 } __packed sctp_ipv4addr_param_t;
 273
 274 /* Section 3.3.2.1. IPv6 Address Parameter (6) */
 275 typedef struct sctp_ipv6addr_param {
 276         sctp_paramhdr_t param_hdr;
 277         struct in6_addr addr;
 278 } __packed sctp_ipv6addr_param_t;
 279
 280 /* Section 3.3.2.1 Cookie Preservative (9) */
 281 typedef struct sctp_cookie_preserve_param {
 282         sctp_paramhdr_t param_hdr;
 283         __be32          lifespan_increment;
 284 } __packed sctp_cookie_preserve_param_t;
 285
 286 /* Section 3.3.2.1 Host Name Address (11) */
 287 typedef struct sctp_hostname_param {
 288         sctp_paramhdr_t param_hdr;
 289         uint8_t hostname[0];
 290 } __packed sctp_hostname_param_t;
 291
 292 /* Section 3.3.2.1 Supported Address Types (12) */
 293 typedef struct sctp_supported_addrs_param {
 294         sctp_paramhdr_t param_hdr;
 295         __be16 types[0];
 296 } __packed sctp_supported_addrs_param_t;
 297
 298 /* Appendix A. ECN Capable (32768) */
 299 typedef struct sctp_ecn_capable_param {
 300         sctp_paramhdr_t param_hdr;
 301 } __packed sctp_ecn_capable_param_t;
 302
 303 /* ADDIP Section 3.2.6 Adaptation Layer Indication */
 304 typedef struct sctp_adaptation_ind_param {
 305         struct sctp_paramhdr param_hdr;
 306         __be32 adaptation_ind;
 307 } __packed sctp_adaptation_ind_param_t;
 308
 309 /* ADDIP Section 4.2.7 Supported Extensions Parameter */
 310 typedef struct sctp_supported_ext_param {
 311         struct sctp_paramhdr param_hdr;
 312         __u8 chunks[0];
 313 } __packed sctp_supported_ext_param_t;
 314
 315 /* AUTH Section 3.1 Random */
 316 typedef struct sctp_random_param {
 317         sctp_paramhdr_t param_hdr;
 318         __u8 random_val[0];
 319 } __packed sctp_random_param_t;
 320
 321 /* AUTH Section 3.2 Chunk List */
 322 typedef struct sctp_chunks_param {
 323         sctp_paramhdr_t param_hdr;
 324         __u8 chunks[0];
 325 } __packed sctp_chunks_param_t;
 326
 327 /* AUTH Section 3.3 HMAC Algorithm */
 328 typedef struct sctp_hmac_algo_param {
 329         sctp_paramhdr_t param_hdr;
 330         __be16 hmac_ids[0];
 331 } __packed sctp_hmac_algo_param_t;
 332
 333 /* RFC 2960.  Section 3.3.3 Initiation Acknowledgement (INIT ACK) (2):
 334  *   The INIT ACK chunk is used to acknowledge the initiation of an SCTP
 335  *   association.
 336  */
 337 typedef sctp_init_chunk_t sctp_initack_chunk_t;
 338
 339 /* Section 3.3.3.1 State Cookie (7) */
 340 typedef struct sctp_cookie_param {
 341         sctp_paramhdr_t p;
 342         __u8 body[0];
 343 } __packed sctp_cookie_param_t;
 344
 345 /* Section 3.3.3.1 Unrecognized Parameters (8) */
 346 typedef struct sctp_unrecognized_param {
 347         sctp_paramhdr_t param_hdr;
 348         sctp_paramhdr_t unrecognized;
 349 } __packed sctp_unrecognized_param_t;
 350
 351
 352
 353 /*
 354  * 3.3.4 Selective Acknowledgement (SACK) (3):
 355  *
 356  *  This chunk is sent to the peer endpoint to acknowledge received DATA
 357  *  chunks and to inform the peer endpoint of gaps in the received
 358  *  subsequences of DATA chunks as represented by their TSNs.
 359  */
 360
 361 typedef struct sctp_gap_ack_block {
 362         __be16 start;
 363         __be16 end;
 364 } __packed sctp_gap_ack_block_t;
 365
 366 typedef __be32 sctp_dup_tsn_t;
 367
 368 typedef union {
 369         sctp_gap_ack_block_t    gab;
 370         sctp_dup_tsn_t          dup;
 371 } sctp_sack_variable_t;
 372
 373 typedef struct sctp_sackhdr {
 374         __be32 cum_tsn_ack;
 375         __be32 a_rwnd;
 376         __be16 num_gap_ack_blocks;
 377         __be16 num_dup_tsns;
 378         sctp_sack_variable_t variable[0];
 379 } __packed sctp_sackhdr_t;
 380
 381 typedef struct sctp_sack_chunk {
 382         sctp_chunkhdr_t chunk_hdr;
 383         sctp_sackhdr_t sack_hdr;
 384 } __packed sctp_sack_chunk_t;
 385
 386
 387 /* RFC 2960.  Section 3.3.5 Heartbeat Request (HEARTBEAT) (4):
 388  *
 389  *  An endpoint should send this chunk to its peer endpoint to probe the
 390  *  reachability of a particular destination transport address defined in
 391  *  the present association.
 392  */
 393
 394 typedef struct sctp_heartbeathdr {
 395         sctp_paramhdr_t info;
 396 } __packed sctp_heartbeathdr_t;
 397
 398 typedef struct sctp_heartbeat_chunk {
 399         sctp_chunkhdr_t chunk_hdr;
 400         sctp_heartbeathdr_t hb_hdr;
 401 } __packed sctp_heartbeat_chunk_t;
 402
 403
 404 /* For the abort and shutdown ACK we must carry the init tag in the
 405  * common header. Just the common header is all that is needed with a
 406  * chunk descriptor.
 407  */
 408 typedef struct sctp_abort_chunk {
 409         sctp_chunkhdr_t uh;
 410 } __packed sctp_abort_chunk_t;
 411
 412
 413 /* For the graceful shutdown we must carry the tag (in common header)
 414  * and the highest consecutive acking value.
 415  */
 416 typedef struct sctp_shutdownhdr {
 417         __be32 cum_tsn_ack;
 418 } __packed sctp_shutdownhdr_t;
 419
 420 struct sctp_shutdown_chunk_t {
 421         sctp_chunkhdr_t    chunk_hdr;
 422         sctp_shutdownhdr_t shutdown_hdr;
 423 } __packed;
 424
 425 /* RFC 2960.  Section 3.3.10 Operation Error (ERROR) (9) */
 426
 427 typedef struct sctp_errhdr {
 428         __be16 cause;
 429         __be16 length;
 430         __u8  variable[0];
 431 } __packed sctp_errhdr_t;
 432
 433 typedef struct sctp_operr_chunk {
 434         sctp_chunkhdr_t chunk_hdr;
 435         sctp_errhdr_t   err_hdr;
 436 } __packed sctp_operr_chunk_t;
 437
 438 /* RFC 2960 3.3.10 - Operation Error
 439  *
 440  * Cause Code: 16 bits (unsigned integer)
 441  *
 442  *     Defines the type of error conditions being reported.
 443  *    Cause Code
 444  *     Value           Cause Code
 445  *     ---------      ----------------
 446  *      1              Invalid Stream Identifier
 447  *      2              Missing Mandatory Parameter
 448  *      3              Stale Cookie Error
 449  *      4              Out of Resource
 450  *      5              Unresolvable Address
 451  *      6              Unrecognized Chunk Type
 452  *      7              Invalid Mandatory Parameter
 453  *      8              Unrecognized Parameters
 454  *      9              No User Data
 455  *     10              Cookie Received While Shutting Down
 456  */
 457 typedef enum {
 458
 459         SCTP_ERROR_NO_ERROR        = cpu_to_be16(0x00),
 460         SCTP_ERROR_INV_STRM        = cpu_to_be16(0x01),
 461         SCTP_ERROR_MISS_PARAM      = cpu_to_be16(0x02),
 462         SCTP_ERROR_STALE_COOKIE    = cpu_to_be16(0x03),
 463         SCTP_ERROR_NO_RESOURCE     = cpu_to_be16(0x04),
 464         SCTP_ERROR_DNS_FAILED      = cpu_to_be16(0x05),
 465         SCTP_ERROR_UNKNOWN_CHUNK   = cpu_to_be16(0x06),
 466         SCTP_ERROR_INV_PARAM       = cpu_to_be16(0x07),
 467         SCTP_ERROR_UNKNOWN_PARAM   = cpu_to_be16(0x08),
 468         SCTP_ERROR_NO_DATA         = cpu_to_be16(0x09),
 469         SCTP_ERROR_COOKIE_IN_SHUTDOWN = cpu_to_be16(0x0a),
 470
 471
 472         /* SCTP Implementation Guide:
 473          *  11  Restart of an association with new addresses
 474          *  12  User Initiated Abort
 475          *  13  Protocol Violation
 476          */
 477
 478         SCTP_ERROR_RESTART         = cpu_to_be16(0x0b),
 479         SCTP_ERROR_USER_ABORT      = cpu_to_be16(0x0c),
 480         SCTP_ERROR_PROTO_VIOLATION = cpu_to_be16(0x0d),
 481
 482         /* ADDIP Section 3.3  New Error Causes
 483          *
 484          * Four new Error Causes are added to the SCTP Operational Errors,
 485          * primarily for use in the ASCONF-ACK chunk.
 486          *
 487          * Value          Cause Code
 488          * ---------      ----------------
 489          * 0x00A0          Request to Delete Last Remaining IP Address.
 490          * 0x00A1          Operation Refused Due to Resource Shortage.
 491          * 0x00A2          Request to Delete Source IP Address.
 492          * 0x00A3          Association Aborted due to illegal ASCONF-ACK
 493          * 0x00A4          Request refused - no authorization.
 494          */
 495         SCTP_ERROR_DEL_LAST_IP  = cpu_to_be16(0x00A0),
 496         SCTP_ERROR_RSRC_LOW     = cpu_to_be16(0x00A1),
 497         SCTP_ERROR_DEL_SRC_IP   = cpu_to_be16(0x00A2),
 498         SCTP_ERROR_ASCONF_ACK   = cpu_to_be16(0x00A3),
 499         SCTP_ERROR_REQ_REFUSED  = cpu_to_be16(0x00A4),
 500
 501         /* AUTH Section 4.  New Error Cause
 502          *
 503          * This section defines a new error cause that will be sent if an AUTH
 504          * chunk is received with an unsupported HMAC identifier.
 505          * illustrates the new error cause.
 506          *
 507          * Cause Code      Error Cause Name
 508          * --------------------------------------------------------------
 509          * 0x0105          Unsupported HMAC Identifier
 510          */
 511          SCTP_ERROR_UNSUP_HMAC  = cpu_to_be16(0x0105)
 512 } sctp_error_t;
 513
 514
 515
 516 /* RFC 2960.  Appendix A.  Explicit Congestion Notification.
 517  *   Explicit Congestion Notification Echo (ECNE) (12)
 518  */
 519 typedef struct sctp_ecnehdr {
 520         __be32 lowest_tsn;
 521 } sctp_ecnehdr_t;
 522
 523 typedef struct sctp_ecne_chunk {
 524         sctp_chunkhdr_t chunk_hdr;
 525         sctp_ecnehdr_t ence_hdr;
 526 } __packed sctp_ecne_chunk_t;
 527
 528 /* RFC 2960.  Appendix A.  Explicit Congestion Notification.
 529  *   Congestion Window Reduced (CWR) (13)
 530  */
 531 typedef struct sctp_cwrhdr {
 532         __be32 lowest_tsn;
 533 } sctp_cwrhdr_t;
 534
 535 typedef struct sctp_cwr_chunk {
 536         sctp_chunkhdr_t chunk_hdr;
 537         sctp_cwrhdr_t cwr_hdr;
 538 } __packed sctp_cwr_chunk_t;
 539
 540 /* PR-SCTP
 541  * 3.2 Forward Cumulative TSN Chunk Definition (FORWARD TSN)
 542  *
 543  * Forward Cumulative TSN chunk has the following format:
 544  *
 545  *        0                   1                   2                   3
 546  *        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
 547  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 548  *      |   Type = 192  |  Flags = 0x00 |        Length = Variable      |
 549  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 550  *      |                      New Cumulative TSN                       |
 551  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 552  *      |         Stream-1              |       Stream Sequence-1       |
 553  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 554  *      \                                                               /
 555  *      /                                                               \
 556  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 557  *      |         Stream-N              |       Stream Sequence-N       |
 558  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 559  *
 560  *      Chunk Flags:
 561  *
 562  *        Set to all zeros on transmit and ignored on receipt.
 563  *
 564  *      New Cumulative TSN: 32 bit u_int
 565  *
 566  *       This indicates the new cumulative TSN to the data receiver. Upon
 567  *       the reception of this value, the data receiver MUST consider
 568  *       any missing TSNs earlier than or equal to this value as received
 569  *       and stop reporting them as gaps in any subsequent SACKs.
 570  *
 571  *      Stream-N: 16 bit u_int
 572  *
 573  *       This field holds a stream number that was skipped by this
 574  *       FWD-TSN.
 575  *
 576  *      Stream Sequence-N: 16 bit u_int
 577  *       This field holds the sequence number associated with the stream
 578  *       that was skipped. The stream sequence field holds the largest stream
 579  *       sequence number in this stream being skipped.  The receiver of
 580  *       the FWD-TSN's can use the Stream-N and Stream Sequence-N fields
 581  *       to enable delivery of any stranded TSN's that remain on the stream
 582  *       re-ordering queues. This field MUST NOT report TSN's corresponding
 583  *       to DATA chunk that are marked as unordered. For ordered DATA
 584  *       chunks this field MUST be filled in.
 585  */
 586 struct sctp_fwdtsn_skip {
 587         __be16 stream;
 588         __be16 ssn;
 589 } __packed;
 590
 591 struct sctp_fwdtsn_hdr {
 592         __be32 new_cum_tsn;
 593         struct sctp_fwdtsn_skip skip[0];
 594 } __packed;
 595
 596 struct sctp_fwdtsn_chunk {
 597         struct sctp_chunkhdr chunk_hdr;
 598         struct sctp_fwdtsn_hdr fwdtsn_hdr;
 599 } __packed;
 600
 601
 602 /* ADDIP
 603  * Section 3.1.1 Address Configuration Change Chunk (ASCONF)
 604  *
 605  *      Serial Number: 32 bits (unsigned integer)
 606  *      This value represents a Serial Number for the ASCONF Chunk. The
 607  *      valid range of Serial Number is from 0 to 2^32-1.
 608  *      Serial Numbers wrap back to 0 after reaching 2^32 -1.
 609  *
 610  *      Address Parameter: 8 or 20 bytes (depending on type)
 611  *      The address is an address of the sender of the ASCONF chunk,
 612  *      the address MUST be considered part of the association by the
 613  *      peer endpoint. This field may be used by the receiver of the
 614  *      ASCONF to help in finding the association. This parameter MUST
 615  *      be present in every ASCONF message i.e. it is a mandatory TLV
 616  *      parameter.
 617  *
 618  *      ASCONF Parameter: TLV format
 619  *      Each Address configuration change is represented by a TLV
 620  *      parameter as defined in Section 3.2. One or more requests may
 621  *      be present in an ASCONF Chunk.
 622  *
 623  * Section 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
 624  *
 625  *      Serial Number: 32 bits (unsigned integer)
 626  *      This value represents the Serial Number for the received ASCONF
 627  *      Chunk that is acknowledged by this chunk. This value is copied
 628  *      from the received ASCONF Chunk.
 629  *
 630  *      ASCONF Parameter Response: TLV format
 631  *      The ASCONF Parameter Response is used in the ASCONF-ACK to
 632  *      report status of ASCONF processing.
 633  */
 634 typedef struct sctp_addip_param {
 635         sctp_paramhdr_t param_hdr;
 636         __be32          crr_id;
 637 } __packed sctp_addip_param_t;
 638
 639 typedef struct sctp_addiphdr {
 640         __be32  serial;
 641         __u8    params[0];
 642 } __packed sctp_addiphdr_t;
 643
 644 typedef struct sctp_addip_chunk {
 645         sctp_chunkhdr_t chunk_hdr;
 646         sctp_addiphdr_t addip_hdr;
 647 } __packed sctp_addip_chunk_t;
 648
 649 /* AUTH
 650  * Section 4.1  Authentication Chunk (AUTH)
 651  *
 652  *   This chunk is used to hold the result of the HMAC calculation.
 653  *
 654  *    0                   1                   2                   3
 655  *    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
 656  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 657  *   | Type = 0x0F   |   Flags=0     |             Length            |
 658  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 659  *   |     Shared Key Identifier     |   HMAC Identifier             |
 660  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 661  *   |                                                               |
 662  *   \                             HMAC                              /
 663  *   /                                                               \
 664  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 665  *
 666  *   Type: 1 byte (unsigned integer)
 667  *      This value MUST be set to 0x0F for  all AUTH-chunks.
 668  *
 669  *   Flags: 1 byte (unsigned integer)
 670  *      Set to zero on transmit and ignored on receipt.
 671  *
 672  *   Length: 2 bytes (unsigned integer)
 673  *      This value holds the length of the HMAC in bytes plus 8.
 674  *
 675  *  Shared Key Identifier: 2 bytes (unsigned integer)
 676  *      This value describes which endpoint pair shared key is used.
 677  *
 678  *   HMAC Identifier: 2 bytes (unsigned integer)
 679  *      This value describes which message digest is being used.  Table 2
 680  *      shows the currently defined values.
 681  *
 682  *    The following Table 2 shows the currently defined values for HMAC
 683  *       identifiers.
 684  *
 685  *       +-----------------+--------------------------+
 686  *       | HMAC Identifier | Message Digest Algorithm |
 687  *       +-----------------+--------------------------+
 688  *       | 0               | Reserved                 |
 689  *       | 1               | SHA-1 defined in [8]     |
 690  *       | 2               | Reserved                 |
 691  *       | 3               | SHA-256 defined in [8]   |
 692  *       +-----------------+--------------------------+
 693  *
 694  *
 695  *   HMAC: n bytes (unsigned integer) This hold the result of the HMAC
 696  *      calculation.
 697  */
 698 typedef struct sctp_authhdr {
 699         __be16 shkey_id;
 700         __be16 hmac_id;
 701         __u8   hmac[0];
 702 } __packed sctp_authhdr_t;
 703
 704 typedef struct sctp_auth_chunk {
 705         sctp_chunkhdr_t chunk_hdr;
 706         sctp_authhdr_t auth_hdr;
 707 } __packed sctp_auth_chunk_t;
 708
 709 #endif /* __LINUX_SCTP_H__ */