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
  57
  58 /* Section 3.1.  SCTP Common Header Format */
  59 typedef struct sctphdr {
  60         __be16 source;
  61         __be16 dest;
  62         __be32 vtag;
  63         __le32 checksum;
  64 } __packed sctp_sctphdr_t;
  65
  66 #ifdef __KERNEL__
  67 #include <linux/skbuff.h>
  68
  69 static inline struct sctphdr *sctp_hdr(const struct sk_buff *skb)
  70 {
  71         return (struct sctphdr *)skb_transport_header(skb);
  72 }
  73 #endif
  74
  75 /* Section 3.2.  Chunk Field Descriptions. */
  76 typedef struct sctp_chunkhdr {
  77         __u8 type;
  78         __u8 flags;
  79         __be16 length;
  80 } __packed sctp_chunkhdr_t;
  81
  82
  83 /* Section 3.2.  Chunk Type Values.
  84  * [Chunk Type] identifies the type of information contained in the Chunk
  85  * Value field. It takes a value from 0 to 254. The value of 255 is
  86  * reserved for future use as an extension field.
  87  */
  88 typedef enum {
  89         SCTP_CID_DATA                   = 0,
  90         SCTP_CID_INIT                   = 1,
  91         SCTP_CID_INIT_ACK               = 2,
  92         SCTP_CID_SACK                   = 3,
  93         SCTP_CID_HEARTBEAT              = 4,
  94         SCTP_CID_HEARTBEAT_ACK          = 5,
  95         SCTP_CID_ABORT                  = 6,
  96         SCTP_CID_SHUTDOWN               = 7,
  97         SCTP_CID_SHUTDOWN_ACK           = 8,
  98         SCTP_CID_ERROR                  = 9,
  99         SCTP_CID_COOKIE_ECHO            = 10,
 100         SCTP_CID_COOKIE_ACK             = 11,
 101         SCTP_CID_ECN_ECNE               = 12,
 102         SCTP_CID_ECN_CWR                = 13,
 103         SCTP_CID_SHUTDOWN_COMPLETE      = 14,
 104
 105         /* AUTH Extension Section 4.1 */
 106         SCTP_CID_AUTH                   = 0x0F,
 107
 108         /* PR-SCTP Sec 3.2 */
 109         SCTP_CID_FWD_TSN                = 0xC0,
 110
 111         /* Use hex, as defined in ADDIP sec. 3.1 */
 112         SCTP_CID_ASCONF                 = 0xC1,
 113         SCTP_CID_ASCONF_ACK             = 0x80,
 114 } sctp_cid_t; /* enum */
 115
 116
 117 /* Section 3.2
 118  *  Chunk Types are encoded such that the highest-order two bits specify
 119  *  the action that must be taken if the processing endpoint does not
 120  *  recognize the Chunk Type.
 121  */
 122 typedef enum {
 123         SCTP_CID_ACTION_DISCARD     = 0x00,
 124         SCTP_CID_ACTION_DISCARD_ERR = 0x40,
 125         SCTP_CID_ACTION_SKIP        = 0x80,
 126         SCTP_CID_ACTION_SKIP_ERR    = 0xc0,
 127 } sctp_cid_action_t;
 128
 129 enum { SCTP_CID_ACTION_MASK = 0xc0, };
 130
 131 /* This flag is used in Chunk Flags for ABORT and SHUTDOWN COMPLETE.
 132  *
 133  * 3.3.7 Abort Association (ABORT) (6):
 134  *    The T bit is set to 0 if the sender had a TCB that it destroyed.
 135  *    If the sender did not have a TCB it should set this bit to 1.
 136  */
 137 enum { SCTP_CHUNK_FLAG_T = 0x01 };
 138
 139 /*
 140  *  Set the T bit
 141  *
 142  *      0                   1                   2                   3
 143  *      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
 144  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 145  *     |   Type = 14   |Reserved     |T|      Length = 4               |
 146  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 147  *
 148  * Chunk Flags: 8 bits
 149  *
 150  *   Reserved:  7 bits
 151  *     Set to 0 on transmit and ignored on receipt.
 152  *
 153  *   T bit:  1 bit
 154  *     The T bit is set to 0 if the sender had a TCB that it destroyed. If
 155  *     the sender did NOT have a TCB it should set this bit to 1.
 156  *
 157  * Note: Special rules apply to this chunk for verification, please
 158  * see Section 8.5.1 for details.
 159  */
 160
 161 #define sctp_test_T_bit(c)    ((c)->chunk_hdr->flags & SCTP_CHUNK_FLAG_T)
 162
 163 /* RFC 2960
 164  * Section 3.2.1 Optional/Variable-length Parmaeter Format.
 165  */
 166
 167 typedef struct sctp_paramhdr {
 168         __be16 type;
 169         __be16 length;
 170 } __packed sctp_paramhdr_t;
 171
 172 typedef enum {
 173
 174         /* RFC 2960 Section 3.3.5 */
 175         SCTP_PARAM_HEARTBEAT_INFO               = cpu_to_be16(1),
 176         /* RFC 2960 Section 3.3.2.1 */
 177         SCTP_PARAM_IPV4_ADDRESS                 = cpu_to_be16(5),
 178         SCTP_PARAM_IPV6_ADDRESS                 = cpu_to_be16(6),
 179         SCTP_PARAM_STATE_COOKIE                 = cpu_to_be16(7),
 180         SCTP_PARAM_UNRECOGNIZED_PARAMETERS      = cpu_to_be16(8),
 181         SCTP_PARAM_COOKIE_PRESERVATIVE          = cpu_to_be16(9),
 182         SCTP_PARAM_HOST_NAME_ADDRESS            = cpu_to_be16(11),
 183         SCTP_PARAM_SUPPORTED_ADDRESS_TYPES      = cpu_to_be16(12),
 184         SCTP_PARAM_ECN_CAPABLE                  = cpu_to_be16(0x8000),
 185
 186         /* AUTH Extension Section 3 */
 187         SCTP_PARAM_RANDOM                       = cpu_to_be16(0x8002),
 188         SCTP_PARAM_CHUNKS                       = cpu_to_be16(0x8003),
 189         SCTP_PARAM_HMAC_ALGO                    = cpu_to_be16(0x8004),
 190
 191         /* Add-IP: Supported Extensions, Section 4.2 */
 192         SCTP_PARAM_SUPPORTED_EXT        = cpu_to_be16(0x8008),
 193
 194         /* PR-SCTP Sec 3.1 */
 195         SCTP_PARAM_FWD_TSN_SUPPORT      = cpu_to_be16(0xc000),
 196
 197         /* Add-IP Extension. Section 3.2 */
 198         SCTP_PARAM_ADD_IP               = cpu_to_be16(0xc001),
 199         SCTP_PARAM_DEL_IP               = cpu_to_be16(0xc002),
 200         SCTP_PARAM_ERR_CAUSE            = cpu_to_be16(0xc003),
 201         SCTP_PARAM_SET_PRIMARY          = cpu_to_be16(0xc004),
 202         SCTP_PARAM_SUCCESS_REPORT       = cpu_to_be16(0xc005),
 203         SCTP_PARAM_ADAPTATION_LAYER_IND = cpu_to_be16(0xc006),
 204
 205 } sctp_param_t; /* enum */
 206
 207
 208 /* RFC 2960 Section 3.2.1
 209  *  The Parameter Types are encoded such that the highest-order two bits
 210  *  specify the action that must be taken if the processing endpoint does
 211  *  not recognize the Parameter Type.
 212  *
 213  */
 214 typedef enum {
 215         SCTP_PARAM_ACTION_DISCARD     = cpu_to_be16(0x0000),
 216         SCTP_PARAM_ACTION_DISCARD_ERR = cpu_to_be16(0x4000),
 217         SCTP_PARAM_ACTION_SKIP        = cpu_to_be16(0x8000),
 218         SCTP_PARAM_ACTION_SKIP_ERR    = cpu_to_be16(0xc000),
 219 } sctp_param_action_t;
 220
 221 enum { SCTP_PARAM_ACTION_MASK = cpu_to_be16(0xc000), };
 222
 223 /* RFC 2960 Section 3.3.1 Payload Data (DATA) (0) */
 224
 225 typedef struct sctp_datahdr {
 226         __be32 tsn;
 227         __be16 stream;
 228         __be16 ssn;
 229         __be32 ppid;
 230         __u8  payload[0];
 231 } __packed sctp_datahdr_t;
 232
 233 typedef struct sctp_data_chunk {
 234         sctp_chunkhdr_t chunk_hdr;
 235         sctp_datahdr_t  data_hdr;
 236 } __packed sctp_data_chunk_t;
 237
 238 /* DATA Chuck Specific Flags */
 239 enum {
 240         SCTP_DATA_MIDDLE_FRAG   = 0x00,
 241         SCTP_DATA_LAST_FRAG     = 0x01,
 242         SCTP_DATA_FIRST_FRAG    = 0x02,
 243         SCTP_DATA_NOT_FRAG      = 0x03,
 244         SCTP_DATA_UNORDERED     = 0x04,
 245         SCTP_DATA_SACK_IMM      = 0x08,
 246 };
 247 enum { SCTP_DATA_FRAG_MASK = 0x03, };
 248
 249
 250 /* RFC 2960 Section 3.3.2 Initiation (INIT) (1)
 251  *
 252  *  This chunk is used to initiate a SCTP association between two
 253  *  endpoints.
 254  */
 255 typedef struct sctp_inithdr {
 256         __be32 init_tag;
 257         __be32 a_rwnd;
 258         __be16 num_outbound_streams;
 259         __be16 num_inbound_streams;
 260         __be32 initial_tsn;
 261         __u8  params[0];
 262 } __packed sctp_inithdr_t;
 263
 264 typedef struct sctp_init_chunk {
 265         sctp_chunkhdr_t chunk_hdr;
 266         sctp_inithdr_t init_hdr;
 267 } __packed sctp_init_chunk_t;
 268
 269
 270 /* Section 3.3.2.1. IPv4 Address Parameter (5) */
 271 typedef struct sctp_ipv4addr_param {
 272         sctp_paramhdr_t param_hdr;
 273         struct in_addr  addr;
 274 } __packed sctp_ipv4addr_param_t;
 275
 276 /* Section 3.3.2.1. IPv6 Address Parameter (6) */
 277 typedef struct sctp_ipv6addr_param {
 278         sctp_paramhdr_t param_hdr;
 279         struct in6_addr addr;
 280 } __packed sctp_ipv6addr_param_t;
 281
 282 /* Section 3.3.2.1 Cookie Preservative (9) */
 283 typedef struct sctp_cookie_preserve_param {
 284         sctp_paramhdr_t param_hdr;
 285         __be32          lifespan_increment;
 286 } __packed sctp_cookie_preserve_param_t;
 287
 288 /* Section 3.3.2.1 Host Name Address (11) */
 289 typedef struct sctp_hostname_param {
 290         sctp_paramhdr_t param_hdr;
 291         uint8_t hostname[0];
 292 } __packed sctp_hostname_param_t;
 293
 294 /* Section 3.3.2.1 Supported Address Types (12) */
 295 typedef struct sctp_supported_addrs_param {
 296         sctp_paramhdr_t param_hdr;
 297         __be16 types[0];
 298 } __packed sctp_supported_addrs_param_t;
 299
 300 /* Appendix A. ECN Capable (32768) */
 301 typedef struct sctp_ecn_capable_param {
 302         sctp_paramhdr_t param_hdr;
 303 } __packed sctp_ecn_capable_param_t;
 304
 305 /* ADDIP Section 3.2.6 Adaptation Layer Indication */
 306 typedef struct sctp_adaptation_ind_param {
 307         struct sctp_paramhdr param_hdr;
 308         __be32 adaptation_ind;
 309 } __packed sctp_adaptation_ind_param_t;
 310
 311 /* ADDIP Section 4.2.7 Supported Extensions Parameter */
 312 typedef struct sctp_supported_ext_param {
 313         struct sctp_paramhdr param_hdr;
 314         __u8 chunks[0];
 315 } __packed sctp_supported_ext_param_t;
 316
 317 /* AUTH Section 3.1 Random */
 318 typedef struct sctp_random_param {
 319         sctp_paramhdr_t param_hdr;
 320         __u8 random_val[0];
 321 } __packed sctp_random_param_t;
 322
 323 /* AUTH Section 3.2 Chunk List */
 324 typedef struct sctp_chunks_param {
 325         sctp_paramhdr_t param_hdr;
 326         __u8 chunks[0];
 327 } __packed sctp_chunks_param_t;
 328
 329 /* AUTH Section 3.3 HMAC Algorithm */
 330 typedef struct sctp_hmac_algo_param {
 331         sctp_paramhdr_t param_hdr;
 332         __be16 hmac_ids[0];
 333 } __packed sctp_hmac_algo_param_t;
 334
 335 /* RFC 2960.  Section 3.3.3 Initiation Acknowledgement (INIT ACK) (2):
 336  *   The INIT ACK chunk is used to acknowledge the initiation of an SCTP
 337  *   association.
 338  */
 339 typedef sctp_init_chunk_t sctp_initack_chunk_t;
 340
 341 /* Section 3.3.3.1 State Cookie (7) */
 342 typedef struct sctp_cookie_param {
 343         sctp_paramhdr_t p;
 344         __u8 body[0];
 345 } __packed sctp_cookie_param_t;
 346
 347 /* Section 3.3.3.1 Unrecognized Parameters (8) */
 348 typedef struct sctp_unrecognized_param {
 349         sctp_paramhdr_t param_hdr;
 350         sctp_paramhdr_t unrecognized;
 351 } __packed sctp_unrecognized_param_t;
 352
 353
 354
 355 /*
 356  * 3.3.4 Selective Acknowledgement (SACK) (3):
 357  *
 358  *  This chunk is sent to the peer endpoint to acknowledge received DATA
 359  *  chunks and to inform the peer endpoint of gaps in the received
 360  *  subsequences of DATA chunks as represented by their TSNs.
 361  */
 362
 363 typedef struct sctp_gap_ack_block {
 364         __be16 start;
 365         __be16 end;
 366 } __packed sctp_gap_ack_block_t;
 367
 368 typedef __be32 sctp_dup_tsn_t;
 369
 370 typedef union {
 371         sctp_gap_ack_block_t    gab;
 372         sctp_dup_tsn_t          dup;
 373 } sctp_sack_variable_t;
 374
 375 typedef struct sctp_sackhdr {
 376         __be32 cum_tsn_ack;
 377         __be32 a_rwnd;
 378         __be16 num_gap_ack_blocks;
 379         __be16 num_dup_tsns;
 380         sctp_sack_variable_t variable[0];
 381 } __packed sctp_sackhdr_t;
 382
 383 typedef struct sctp_sack_chunk {
 384         sctp_chunkhdr_t chunk_hdr;
 385         sctp_sackhdr_t sack_hdr;
 386 } __packed sctp_sack_chunk_t;
 387
 388
 389 /* RFC 2960.  Section 3.3.5 Heartbeat Request (HEARTBEAT) (4):
 390  *
 391  *  An endpoint should send this chunk to its peer endpoint to probe the
 392  *  reachability of a particular destination transport address defined in
 393  *  the present association.
 394  */
 395
 396 typedef struct sctp_heartbeathdr {
 397         sctp_paramhdr_t info;
 398 } __packed sctp_heartbeathdr_t;
 399
 400 typedef struct sctp_heartbeat_chunk {
 401         sctp_chunkhdr_t chunk_hdr;
 402         sctp_heartbeathdr_t hb_hdr;
 403 } __packed sctp_heartbeat_chunk_t;
 404
 405
 406 /* For the abort and shutdown ACK we must carry the init tag in the
 407  * common header. Just the common header is all that is needed with a
 408  * chunk descriptor.
 409  */
 410 typedef struct sctp_abort_chunk {
 411         sctp_chunkhdr_t uh;
 412 } __packed sctp_abort_chunk_t;
 413
 414
 415 /* For the graceful shutdown we must carry the tag (in common header)
 416  * and the highest consecutive acking value.
 417  */
 418 typedef struct sctp_shutdownhdr {
 419         __be32 cum_tsn_ack;
 420 } __packed sctp_shutdownhdr_t;
 421
 422 struct sctp_shutdown_chunk_t {
 423         sctp_chunkhdr_t    chunk_hdr;
 424         sctp_shutdownhdr_t shutdown_hdr;
 425 } __packed;
 426
 427 /* RFC 2960.  Section 3.3.10 Operation Error (ERROR) (9) */
 428
 429 typedef struct sctp_errhdr {
 430         __be16 cause;
 431         __be16 length;
 432         __u8  variable[0];
 433 } __packed sctp_errhdr_t;
 434
 435 typedef struct sctp_operr_chunk {
 436         sctp_chunkhdr_t chunk_hdr;
 437         sctp_errhdr_t   err_hdr;
 438 } __packed sctp_operr_chunk_t;
 439
 440 /* RFC 2960 3.3.10 - Operation Error
 441  *
 442  * Cause Code: 16 bits (unsigned integer)
 443  *
 444  *     Defines the type of error conditions being reported.
 445  *    Cause Code
 446  *     Value           Cause Code
 447  *     ---------      ----------------
 448  *      1              Invalid Stream Identifier
 449  *      2              Missing Mandatory Parameter
 450  *      3              Stale Cookie Error
 451  *      4              Out of Resource
 452  *      5              Unresolvable Address
 453  *      6              Unrecognized Chunk Type
 454  *      7              Invalid Mandatory Parameter
 455  *      8              Unrecognized Parameters
 456  *      9              No User Data
 457  *     10              Cookie Received While Shutting Down
 458  */
 459 typedef enum {
 460
 461         SCTP_ERROR_NO_ERROR        = cpu_to_be16(0x00),
 462         SCTP_ERROR_INV_STRM        = cpu_to_be16(0x01),
 463         SCTP_ERROR_MISS_PARAM      = cpu_to_be16(0x02),
 464         SCTP_ERROR_STALE_COOKIE    = cpu_to_be16(0x03),
 465         SCTP_ERROR_NO_RESOURCE     = cpu_to_be16(0x04),
 466         SCTP_ERROR_DNS_FAILED      = cpu_to_be16(0x05),
 467         SCTP_ERROR_UNKNOWN_CHUNK   = cpu_to_be16(0x06),
 468         SCTP_ERROR_INV_PARAM       = cpu_to_be16(0x07),
 469         SCTP_ERROR_UNKNOWN_PARAM   = cpu_to_be16(0x08),
 470         SCTP_ERROR_NO_DATA         = cpu_to_be16(0x09),
 471         SCTP_ERROR_COOKIE_IN_SHUTDOWN = cpu_to_be16(0x0a),
 472
 473
 474         /* SCTP Implementation Guide:
 475          *  11  Restart of an association with new addresses
 476          *  12  User Initiated Abort
 477          *  13  Protocol Violation
 478          */
 479
 480         SCTP_ERROR_RESTART         = cpu_to_be16(0x0b),
 481         SCTP_ERROR_USER_ABORT      = cpu_to_be16(0x0c),
 482         SCTP_ERROR_PROTO_VIOLATION = cpu_to_be16(0x0d),
 483
 484         /* ADDIP Section 3.3  New Error Causes
 485          *
 486          * Four new Error Causes are added to the SCTP Operational Errors,
 487          * primarily for use in the ASCONF-ACK chunk.
 488          *
 489          * Value          Cause Code
 490          * ---------      ----------------
 491          * 0x00A0          Request to Delete Last Remaining IP Address.
 492          * 0x00A1          Operation Refused Due to Resource Shortage.
 493          * 0x00A2          Request to Delete Source IP Address.
 494          * 0x00A3          Association Aborted due to illegal ASCONF-ACK
 495          * 0x00A4          Request refused - no authorization.
 496          */
 497         SCTP_ERROR_DEL_LAST_IP  = cpu_to_be16(0x00A0),
 498         SCTP_ERROR_RSRC_LOW     = cpu_to_be16(0x00A1),
 499         SCTP_ERROR_DEL_SRC_IP   = cpu_to_be16(0x00A2),
 500         SCTP_ERROR_ASCONF_ACK   = cpu_to_be16(0x00A3),
 501         SCTP_ERROR_REQ_REFUSED  = cpu_to_be16(0x00A4),
 502
 503         /* AUTH Section 4.  New Error Cause
 504          *
 505          * This section defines a new error cause that will be sent if an AUTH
 506          * chunk is received with an unsupported HMAC identifier.
 507          * illustrates the new error cause.
 508          *
 509          * Cause Code      Error Cause Name
 510          * --------------------------------------------------------------
 511          * 0x0105          Unsupported HMAC Identifier
 512          */
 513          SCTP_ERROR_UNSUP_HMAC  = cpu_to_be16(0x0105)
 514 } sctp_error_t;
 515
 516
 517
 518 /* RFC 2960.  Appendix A.  Explicit Congestion Notification.
 519  *   Explicit Congestion Notification Echo (ECNE) (12)
 520  */
 521 typedef struct sctp_ecnehdr {
 522         __be32 lowest_tsn;
 523 } sctp_ecnehdr_t;
 524
 525 typedef struct sctp_ecne_chunk {
 526         sctp_chunkhdr_t chunk_hdr;
 527         sctp_ecnehdr_t ence_hdr;
 528 } __packed sctp_ecne_chunk_t;
 529
 530 /* RFC 2960.  Appendix A.  Explicit Congestion Notification.
 531  *   Congestion Window Reduced (CWR) (13)
 532  */
 533 typedef struct sctp_cwrhdr {
 534         __be32 lowest_tsn;
 535 } sctp_cwrhdr_t;
 536
 537 typedef struct sctp_cwr_chunk {
 538         sctp_chunkhdr_t chunk_hdr;
 539         sctp_cwrhdr_t cwr_hdr;
 540 } __packed sctp_cwr_chunk_t;
 541
 542 /* PR-SCTP
 543  * 3.2 Forward Cumulative TSN Chunk Definition (FORWARD TSN)
 544  *
 545  * Forward Cumulative TSN chunk has the following format:
 546  *
 547  *        0                   1                   2                   3
 548  *        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
 549  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 550  *      |   Type = 192  |  Flags = 0x00 |        Length = Variable      |
 551  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 552  *      |                      New Cumulative TSN                       |
 553  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 554  *      |         Stream-1              |       Stream Sequence-1       |
 555  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 556  *      \                                                               /
 557  *      /                                                               \
 558  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 559  *      |         Stream-N              |       Stream Sequence-N       |
 560  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 561  *
 562  *      Chunk Flags:
 563  *
 564  *        Set to all zeros on transmit and ignored on receipt.
 565  *
 566  *      New Cumulative TSN: 32 bit u_int
 567  *
 568  *       This indicates the new cumulative TSN to the data receiver. Upon
 569  *       the reception of this value, the data receiver MUST consider
 570  *       any missing TSNs earlier than or equal to this value as received
 571  *       and stop reporting them as gaps in any subsequent SACKs.
 572  *
 573  *      Stream-N: 16 bit u_int
 574  *
 575  *       This field holds a stream number that was skipped by this
 576  *       FWD-TSN.
 577  *
 578  *      Stream Sequence-N: 16 bit u_int
 579  *       This field holds the sequence number associated with the stream
 580  *       that was skipped. The stream sequence field holds the largest stream
 581  *       sequence number in this stream being skipped.  The receiver of
 582  *       the FWD-TSN's can use the Stream-N and Stream Sequence-N fields
 583  *       to enable delivery of any stranded TSN's that remain on the stream
 584  *       re-ordering queues. This field MUST NOT report TSN's corresponding
 585  *       to DATA chunk that are marked as unordered. For ordered DATA
 586  *       chunks this field MUST be filled in.
 587  */
 588 struct sctp_fwdtsn_skip {
 589         __be16 stream;
 590         __be16 ssn;
 591 } __packed;
 592
 593 struct sctp_fwdtsn_hdr {
 594         __be32 new_cum_tsn;
 595         struct sctp_fwdtsn_skip skip[0];
 596 } __packed;
 597
 598 struct sctp_fwdtsn_chunk {
 599         struct sctp_chunkhdr chunk_hdr;
 600         struct sctp_fwdtsn_hdr fwdtsn_hdr;
 601 } __packed;
 602
 603
 604 /* ADDIP
 605  * Section 3.1.1 Address Configuration Change Chunk (ASCONF)
 606  *
 607  *      Serial Number: 32 bits (unsigned integer)
 608  *      This value represents a Serial Number for the ASCONF Chunk. The
 609  *      valid range of Serial Number is from 0 to 2^32-1.
 610  *      Serial Numbers wrap back to 0 after reaching 2^32 -1.
 611  *
 612  *      Address Parameter: 8 or 20 bytes (depending on type)
 613  *      The address is an address of the sender of the ASCONF chunk,
 614  *      the address MUST be considered part of the association by the
 615  *      peer endpoint. This field may be used by the receiver of the
 616  *      ASCONF to help in finding the association. This parameter MUST
 617  *      be present in every ASCONF message i.e. it is a mandatory TLV
 618  *      parameter.
 619  *
 620  *      ASCONF Parameter: TLV format
 621  *      Each Address configuration change is represented by a TLV
 622  *      parameter as defined in Section 3.2. One or more requests may
 623  *      be present in an ASCONF Chunk.
 624  *
 625  * Section 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
 626  *
 627  *      Serial Number: 32 bits (unsigned integer)
 628  *      This value represents the Serial Number for the received ASCONF
 629  *      Chunk that is acknowledged by this chunk. This value is copied
 630  *      from the received ASCONF Chunk.
 631  *
 632  *      ASCONF Parameter Response: TLV format
 633  *      The ASCONF Parameter Response is used in the ASCONF-ACK to
 634  *      report status of ASCONF processing.
 635  */
 636 typedef struct sctp_addip_param {
 637         sctp_paramhdr_t param_hdr;
 638         __be32          crr_id;
 639 } __packed sctp_addip_param_t;
 640
 641 typedef struct sctp_addiphdr {
 642         __be32  serial;
 643         __u8    params[0];
 644 } __packed sctp_addiphdr_t;
 645
 646 typedef struct sctp_addip_chunk {
 647         sctp_chunkhdr_t chunk_hdr;
 648         sctp_addiphdr_t addip_hdr;
 649 } __packed sctp_addip_chunk_t;
 650
 651 /* AUTH
 652  * Section 4.1  Authentication Chunk (AUTH)
 653  *
 654  *   This chunk is used to hold the result of the HMAC calculation.
 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  *   | Type = 0x0F   |   Flags=0     |             Length            |
 660  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 661  *   |     Shared Key Identifier     |   HMAC Identifier             |
 662  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 663  *   |                                                               |
 664  *   \                             HMAC                              /
 665  *   /                                                               \
 666  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 667  *
 668  *   Type: 1 byte (unsigned integer)
 669  *      This value MUST be set to 0x0F for  all AUTH-chunks.
 670  *
 671  *   Flags: 1 byte (unsigned integer)
 672  *      Set to zero on transmit and ignored on receipt.
 673  *
 674  *   Length: 2 bytes (unsigned integer)
 675  *      This value holds the length of the HMAC in bytes plus 8.
 676  *
 677  *  Shared Key Identifier: 2 bytes (unsigned integer)
 678  *      This value describes which endpoint pair shared key is used.
 679  *
 680  *   HMAC Identifier: 2 bytes (unsigned integer)
 681  *      This value describes which message digest is being used.  Table 2
 682  *      shows the currently defined values.
 683  *
 684  *    The following Table 2 shows the currently defined values for HMAC
 685  *       identifiers.
 686  *
 687  *       +-----------------+--------------------------+
 688  *       | HMAC Identifier | Message Digest Algorithm |
 689  *       +-----------------+--------------------------+
 690  *       | 0               | Reserved                 |
 691  *       | 1               | SHA-1 defined in [8]     |
 692  *       | 2               | Reserved                 |
 693  *       | 3               | SHA-256 defined in [8]   |
 694  *       +-----------------+--------------------------+
 695  *
 696  *
 697  *   HMAC: n bytes (unsigned integer) This hold the result of the HMAC
 698  *      calculation.
 699  */
 700 typedef struct sctp_authhdr {
 701         __be16 shkey_id;
 702         __be16 hmac_id;
 703         __u8   hmac[0];
 704 } __packed sctp_authhdr_t;
 705
 706 typedef struct sctp_auth_chunk {
 707         sctp_chunkhdr_t chunk_hdr;
 708         sctp_authhdr_t auth_hdr;
 709 } __packed sctp_auth_chunk_t;
 710
 711 #endif /* __LINUX_SCTP_H__ */