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 * The SCTP reference 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 * The SCTP reference 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 <[email protected]> 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 <[email protected]> 39 * Karl Knutson <[email protected]> 40 * Jon Grimm <[email protected]> 41 * Xingang Guo <[email protected]> 42 * [email protected] 43 * [email protected] 44 * [email protected] 45 * Sridhar Samudrala <[email protected]> 46 * Kevin Gao <[email protected]> 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 __be32 checksum; 64 } __attribute__((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 } __attribute__((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 /* PR-SCTP Sec 3.2 */ 106 SCTP_CID_FWD_TSN = 0xC0, 107 108 /* Use hex, as defined in ADDIP sec. 3.1 */ 109 SCTP_CID_ASCONF = 0xC1, 110 SCTP_CID_ASCONF_ACK = 0x80, 111 } sctp_cid_t; /* enum */ 112 113 114 /* Section 3.2 115 * Chunk Types are encoded such that the highest-order two bits specify 116 * the action that must be taken if the processing endpoint does not 117 * recognize the Chunk Type. 118 */ 119 typedef enum { 120 SCTP_CID_ACTION_DISCARD = 0x00, 121 SCTP_CID_ACTION_DISCARD_ERR = 0x40, 122 SCTP_CID_ACTION_SKIP = 0x80, 123 SCTP_CID_ACTION_SKIP_ERR = 0xc0, 124 } sctp_cid_action_t; 125 126 enum { SCTP_CID_ACTION_MASK = 0xc0, }; 127 128 /* This flag is used in Chunk Flags for ABORT and SHUTDOWN COMPLETE. 129 * 130 * 3.3.7 Abort Association (ABORT) (6): 131 * The T bit is set to 0 if the sender had a TCB that it destroyed. 132 * If the sender did not have a TCB it should set this bit to 1. 133 */ 134 enum { SCTP_CHUNK_FLAG_T = 0x01 }; 135 136 /* 137 * Set the T bit 138 * 139 * 0 1 2 3 140 * 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 1 141 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 142 * | Type = 14 |Reserved |T| Length = 4 | 143 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 144 * 145 * Chunk Flags: 8 bits 146 * 147 * Reserved: 7 bits 148 * Set to 0 on transmit and ignored on receipt. 149 * 150 * T bit: 1 bit 151 * The T bit is set to 0 if the sender had a TCB that it destroyed. If 152 * the sender did NOT have a TCB it should set this bit to 1. 153 * 154 * Note: Special rules apply to this chunk for verification, please 155 * see Section 8.5.1 for details. 156 */ 157 158 #define sctp_test_T_bit(c) ((c)->chunk_hdr->flags & SCTP_CHUNK_FLAG_T) 159 160 /* RFC 2960 161 * Section 3.2.1 Optional/Variable-length Parmaeter Format. 162 */ 163 164 typedef struct sctp_paramhdr { 165 __be16 type; 166 __be16 length; 167 } __attribute__((packed)) sctp_paramhdr_t; 168 169 typedef enum { 170 171 /* RFC 2960 Section 3.3.5 */ 172 SCTP_PARAM_HEARTBEAT_INFO = __constant_htons(1), 173 /* RFC 2960 Section 3.3.2.1 */ 174 SCTP_PARAM_IPV4_ADDRESS = __constant_htons(5), 175 SCTP_PARAM_IPV6_ADDRESS = __constant_htons(6), 176 SCTP_PARAM_STATE_COOKIE = __constant_htons(7), 177 SCTP_PARAM_UNRECOGNIZED_PARAMETERS = __constant_htons(8), 178 SCTP_PARAM_COOKIE_PRESERVATIVE = __constant_htons(9), 179 SCTP_PARAM_HOST_NAME_ADDRESS = __constant_htons(11), 180 SCTP_PARAM_SUPPORTED_ADDRESS_TYPES = __constant_htons(12), 181 SCTP_PARAM_ECN_CAPABLE = __constant_htons(0x8000), 182 183 /* PR-SCTP Sec 3.1 */ 184 SCTP_PARAM_FWD_TSN_SUPPORT = __constant_htons(0xc000), 185 186 /* Add-IP Extension. Section 3.2 */ 187 SCTP_PARAM_ADD_IP = __constant_htons(0xc001), 188 SCTP_PARAM_DEL_IP = __constant_htons(0xc002), 189 SCTP_PARAM_ERR_CAUSE = __constant_htons(0xc003), 190 SCTP_PARAM_SET_PRIMARY = __constant_htons(0xc004), 191 SCTP_PARAM_SUCCESS_REPORT = __constant_htons(0xc005), 192 SCTP_PARAM_ADAPTATION_LAYER_IND = __constant_htons(0xc006), 193 194 } sctp_param_t; /* enum */ 195 196 197 /* RFC 2960 Section 3.2.1 198 * The Parameter Types are encoded such that the highest-order two bits 199 * specify the action that must be taken if the processing endpoint does 200 * not recognize the Parameter Type. 201 * 202 */ 203 typedef enum { 204 SCTP_PARAM_ACTION_DISCARD = __constant_htons(0x0000), 205 SCTP_PARAM_ACTION_DISCARD_ERR = __constant_htons(0x4000), 206 SCTP_PARAM_ACTION_SKIP = __constant_htons(0x8000), 207 SCTP_PARAM_ACTION_SKIP_ERR = __constant_htons(0xc000), 208 } sctp_param_action_t; 209 210 enum { SCTP_PARAM_ACTION_MASK = __constant_htons(0xc000), }; 211 212 /* RFC 2960 Section 3.3.1 Payload Data (DATA) (0) */ 213 214 typedef struct sctp_datahdr { 215 __be32 tsn; 216 __be16 stream; 217 __be16 ssn; 218 __be32 ppid; 219 __u8 payload[0]; 220 } __attribute__((packed)) sctp_datahdr_t; 221 222 typedef struct sctp_data_chunk { 223 sctp_chunkhdr_t chunk_hdr; 224 sctp_datahdr_t data_hdr; 225 } __attribute__((packed)) sctp_data_chunk_t; 226 227 /* DATA Chuck Specific Flags */ 228 enum { 229 SCTP_DATA_MIDDLE_FRAG = 0x00, 230 SCTP_DATA_LAST_FRAG = 0x01, 231 SCTP_DATA_FIRST_FRAG = 0x02, 232 SCTP_DATA_NOT_FRAG = 0x03, 233 SCTP_DATA_UNORDERED = 0x04, 234 }; 235 enum { SCTP_DATA_FRAG_MASK = 0x03, }; 236 237 238 /* RFC 2960 Section 3.3.2 Initiation (INIT) (1) 239 * 240 * This chunk is used to initiate a SCTP association between two 241 * endpoints. 242 */ 243 typedef struct sctp_inithdr { 244 __be32 init_tag; 245 __be32 a_rwnd; 246 __be16 num_outbound_streams; 247 __be16 num_inbound_streams; 248 __be32 initial_tsn; 249 __u8 params[0]; 250 } __attribute__((packed)) sctp_inithdr_t; 251 252 typedef struct sctp_init_chunk { 253 sctp_chunkhdr_t chunk_hdr; 254 sctp_inithdr_t init_hdr; 255 } __attribute__((packed)) sctp_init_chunk_t; 256 257 258 /* Section 3.3.2.1. IPv4 Address Parameter (5) */ 259 typedef struct sctp_ipv4addr_param { 260 sctp_paramhdr_t param_hdr; 261 struct in_addr addr; 262 } __attribute__((packed)) sctp_ipv4addr_param_t; 263 264 /* Section 3.3.2.1. IPv6 Address Parameter (6) */ 265 typedef struct sctp_ipv6addr_param { 266 sctp_paramhdr_t param_hdr; 267 struct in6_addr addr; 268 } __attribute__((packed)) sctp_ipv6addr_param_t; 269 270 /* Section 3.3.2.1 Cookie Preservative (9) */ 271 typedef struct sctp_cookie_preserve_param { 272 sctp_paramhdr_t param_hdr; 273 __be32 lifespan_increment; 274 } __attribute__((packed)) sctp_cookie_preserve_param_t; 275 276 /* Section 3.3.2.1 Host Name Address (11) */ 277 typedef struct sctp_hostname_param { 278 sctp_paramhdr_t param_hdr; 279 uint8_t hostname[0]; 280 } __attribute__((packed)) sctp_hostname_param_t; 281 282 /* Section 3.3.2.1 Supported Address Types (12) */ 283 typedef struct sctp_supported_addrs_param { 284 sctp_paramhdr_t param_hdr; 285 __be16 types[0]; 286 } __attribute__((packed)) sctp_supported_addrs_param_t; 287 288 /* Appendix A. ECN Capable (32768) */ 289 typedef struct sctp_ecn_capable_param { 290 sctp_paramhdr_t param_hdr; 291 } __attribute__((packed)) sctp_ecn_capable_param_t; 292 293 /* ADDIP Section 3.2.6 Adaptation Layer Indication */ 294 typedef struct sctp_adaptation_ind_param { 295 struct sctp_paramhdr param_hdr; 296 __be32 adaptation_ind; 297 } __attribute__((packed)) sctp_adaptation_ind_param_t; 298 299 /* RFC 2960. Section 3.3.3 Initiation Acknowledgement (INIT ACK) (2): 300 * The INIT ACK chunk is used to acknowledge the initiation of an SCTP 301 * association. 302 */ 303 typedef sctp_init_chunk_t sctp_initack_chunk_t; 304 305 /* Section 3.3.3.1 State Cookie (7) */ 306 typedef struct sctp_cookie_param { 307 sctp_paramhdr_t p; 308 __u8 body[0]; 309 } __attribute__((packed)) sctp_cookie_param_t; 310 311 /* Section 3.3.3.1 Unrecognized Parameters (8) */ 312 typedef struct sctp_unrecognized_param { 313 sctp_paramhdr_t param_hdr; 314 sctp_paramhdr_t unrecognized; 315 } __attribute__((packed)) sctp_unrecognized_param_t; 316 317 318 319 /* 320 * 3.3.4 Selective Acknowledgement (SACK) (3): 321 * 322 * This chunk is sent to the peer endpoint to acknowledge received DATA 323 * chunks and to inform the peer endpoint of gaps in the received 324 * subsequences of DATA chunks as represented by their TSNs. 325 */ 326 327 typedef struct sctp_gap_ack_block { 328 __be16 start; 329 __be16 end; 330 } __attribute__((packed)) sctp_gap_ack_block_t; 331 332 typedef __be32 sctp_dup_tsn_t; 333 334 typedef union { 335 sctp_gap_ack_block_t gab; 336 sctp_dup_tsn_t dup; 337 } sctp_sack_variable_t; 338 339 typedef struct sctp_sackhdr { 340 __be32 cum_tsn_ack; 341 __be32 a_rwnd; 342 __be16 num_gap_ack_blocks; 343 __be16 num_dup_tsns; 344 sctp_sack_variable_t variable[0]; 345 } __attribute__((packed)) sctp_sackhdr_t; 346 347 typedef struct sctp_sack_chunk { 348 sctp_chunkhdr_t chunk_hdr; 349 sctp_sackhdr_t sack_hdr; 350 } __attribute__((packed)) sctp_sack_chunk_t; 351 352 353 /* RFC 2960. Section 3.3.5 Heartbeat Request (HEARTBEAT) (4): 354 * 355 * An endpoint should send this chunk to its peer endpoint to probe the 356 * reachability of a particular destination transport address defined in 357 * the present association. 358 */ 359 360 typedef struct sctp_heartbeathdr { 361 sctp_paramhdr_t info; 362 } __attribute__((packed)) sctp_heartbeathdr_t; 363 364 typedef struct sctp_heartbeat_chunk { 365 sctp_chunkhdr_t chunk_hdr; 366 sctp_heartbeathdr_t hb_hdr; 367 } __attribute__((packed)) sctp_heartbeat_chunk_t; 368 369 370 /* For the abort and shutdown ACK we must carry the init tag in the 371 * common header. Just the common header is all that is needed with a 372 * chunk descriptor. 373 */ 374 typedef struct sctp_abort_chunk { 375 sctp_chunkhdr_t uh; 376 } __attribute__((packed)) sctp_abort_chunk_t; 377 378 379 /* For the graceful shutdown we must carry the tag (in common header) 380 * and the highest consecutive acking value. 381 */ 382 typedef struct sctp_shutdownhdr { 383 __be32 cum_tsn_ack; 384 } __attribute__((packed)) sctp_shutdownhdr_t; 385 386 struct sctp_shutdown_chunk_t { 387 sctp_chunkhdr_t chunk_hdr; 388 sctp_shutdownhdr_t shutdown_hdr; 389 } __attribute__ ((packed)); 390 391 /* RFC 2960. Section 3.3.10 Operation Error (ERROR) (9) */ 392 393 typedef struct sctp_errhdr { 394 __be16 cause; 395 __be16 length; 396 __u8 variable[0]; 397 } __attribute__((packed)) sctp_errhdr_t; 398 399 typedef struct sctp_operr_chunk { 400 sctp_chunkhdr_t chunk_hdr; 401 sctp_errhdr_t err_hdr; 402 } __attribute__((packed)) sctp_operr_chunk_t; 403 404 /* RFC 2960 3.3.10 - Operation Error 405 * 406 * Cause Code: 16 bits (unsigned integer) 407 * 408 * Defines the type of error conditions being reported. 409 * Cause Code 410 * Value Cause Code 411 * --------- ---------------- 412 * 1 Invalid Stream Identifier 413 * 2 Missing Mandatory Parameter 414 * 3 Stale Cookie Error 415 * 4 Out of Resource 416 * 5 Unresolvable Address 417 * 6 Unrecognized Chunk Type 418 * 7 Invalid Mandatory Parameter 419 * 8 Unrecognized Parameters 420 * 9 No User Data 421 * 10 Cookie Received While Shutting Down 422 */ 423 typedef enum { 424 425 SCTP_ERROR_NO_ERROR = __constant_htons(0x00), 426 SCTP_ERROR_INV_STRM = __constant_htons(0x01), 427 SCTP_ERROR_MISS_PARAM = __constant_htons(0x02), 428 SCTP_ERROR_STALE_COOKIE = __constant_htons(0x03), 429 SCTP_ERROR_NO_RESOURCE = __constant_htons(0x04), 430 SCTP_ERROR_DNS_FAILED = __constant_htons(0x05), 431 SCTP_ERROR_UNKNOWN_CHUNK = __constant_htons(0x06), 432 SCTP_ERROR_INV_PARAM = __constant_htons(0x07), 433 SCTP_ERROR_UNKNOWN_PARAM = __constant_htons(0x08), 434 SCTP_ERROR_NO_DATA = __constant_htons(0x09), 435 SCTP_ERROR_COOKIE_IN_SHUTDOWN = __constant_htons(0x0a), 436 437 438 /* SCTP Implementation Guide: 439 * 11 Restart of an association with new addresses 440 * 12 User Initiated Abort 441 * 13 Protocol Violation 442 */ 443 444 SCTP_ERROR_RESTART = __constant_htons(0x0b), 445 SCTP_ERROR_USER_ABORT = __constant_htons(0x0c), 446 SCTP_ERROR_PROTO_VIOLATION = __constant_htons(0x0d), 447 448 /* ADDIP Section 3.3 New Error Causes 449 * 450 * Four new Error Causes are added to the SCTP Operational Errors, 451 * primarily for use in the ASCONF-ACK chunk. 452 * 453 * Value Cause Code 454 * --------- ---------------- 455 * 0x0100 Request to Delete Last Remaining IP Address. 456 * 0x0101 Operation Refused Due to Resource Shortage. 457 * 0x0102 Request to Delete Source IP Address. 458 * 0x0103 Association Aborted due to illegal ASCONF-ACK 459 * 0x0104 Request refused - no authorization. 460 */ 461 SCTP_ERROR_DEL_LAST_IP = __constant_htons(0x0100), 462 SCTP_ERROR_RSRC_LOW = __constant_htons(0x0101), 463 SCTP_ERROR_DEL_SRC_IP = __constant_htons(0x0102), 464 SCTP_ERROR_ASCONF_ACK = __constant_htons(0x0103), 465 SCTP_ERROR_REQ_REFUSED = __constant_htons(0x0104) 466 } sctp_error_t; 467 468 469 470 /* RFC 2960. Appendix A. Explicit Congestion Notification. 471 * Explicit Congestion Notification Echo (ECNE) (12) 472 */ 473 typedef struct sctp_ecnehdr { 474 __be32 lowest_tsn; 475 } sctp_ecnehdr_t; 476 477 typedef struct sctp_ecne_chunk { 478 sctp_chunkhdr_t chunk_hdr; 479 sctp_ecnehdr_t ence_hdr; 480 } __attribute__((packed)) sctp_ecne_chunk_t; 481 482 /* RFC 2960. Appendix A. Explicit Congestion Notification. 483 * Congestion Window Reduced (CWR) (13) 484 */ 485 typedef struct sctp_cwrhdr { 486 __be32 lowest_tsn; 487 } sctp_cwrhdr_t; 488 489 typedef struct sctp_cwr_chunk { 490 sctp_chunkhdr_t chunk_hdr; 491 sctp_cwrhdr_t cwr_hdr; 492 } __attribute__((packed)) sctp_cwr_chunk_t; 493 494 /* PR-SCTP 495 * 3.2 Forward Cumulative TSN Chunk Definition (FORWARD TSN) 496 * 497 * Forward Cumulative TSN chunk has the following format: 498 * 499 * 0 1 2 3 500 * 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 1 501 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 502 * | Type = 192 | Flags = 0x00 | Length = Variable | 503 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 504 * | New Cumulative TSN | 505 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 506 * | Stream-1 | Stream Sequence-1 | 507 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 508 * \ / 509 * / \ 510 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 511 * | Stream-N | Stream Sequence-N | 512 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 513 * 514 * Chunk Flags: 515 * 516 * Set to all zeros on transmit and ignored on receipt. 517 * 518 * New Cumulative TSN: 32 bit u_int 519 * 520 * This indicates the new cumulative TSN to the data receiver. Upon 521 * the reception of this value, the data receiver MUST consider 522 * any missing TSNs earlier than or equal to this value as received 523 * and stop reporting them as gaps in any subsequent SACKs. 524 * 525 * Stream-N: 16 bit u_int 526 * 527 * This field holds a stream number that was skipped by this 528 * FWD-TSN. 529 * 530 * Stream Sequence-N: 16 bit u_int 531 * This field holds the sequence number associated with the stream 532 * that was skipped. The stream sequence field holds the largest stream 533 * sequence number in this stream being skipped. The receiver of 534 * the FWD-TSN's can use the Stream-N and Stream Sequence-N fields 535 * to enable delivery of any stranded TSN's that remain on the stream 536 * re-ordering queues. This field MUST NOT report TSN's corresponding 537 * to DATA chunk that are marked as unordered. For ordered DATA 538 * chunks this field MUST be filled in. 539 */ 540 struct sctp_fwdtsn_skip { 541 __be16 stream; 542 __be16 ssn; 543 } __attribute__((packed)); 544 545 struct sctp_fwdtsn_hdr { 546 __be32 new_cum_tsn; 547 struct sctp_fwdtsn_skip skip[0]; 548 } __attribute((packed)); 549 550 struct sctp_fwdtsn_chunk { 551 struct sctp_chunkhdr chunk_hdr; 552 struct sctp_fwdtsn_hdr fwdtsn_hdr; 553 } __attribute((packed)); 554 555 556 /* ADDIP 557 * Section 3.1.1 Address Configuration Change Chunk (ASCONF) 558 * 559 * Serial Number: 32 bits (unsigned integer) 560 * This value represents a Serial Number for the ASCONF Chunk. The 561 * valid range of Serial Number is from 0 to 2^32-1. 562 * Serial Numbers wrap back to 0 after reaching 2^32 -1. 563 * 564 * Address Parameter: 8 or 20 bytes (depending on type) 565 * The address is an address of the sender of the ASCONF chunk, 566 * the address MUST be considered part of the association by the 567 * peer endpoint. This field may be used by the receiver of the 568 * ASCONF to help in finding the association. This parameter MUST 569 * be present in every ASCONF message i.e. it is a mandatory TLV 570 * parameter. 571 * 572 * ASCONF Parameter: TLV format 573 * Each Address configuration change is represented by a TLV 574 * parameter as defined in Section 3.2. One or more requests may 575 * be present in an ASCONF Chunk. 576 * 577 * Section 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 578 * 579 * Serial Number: 32 bits (unsigned integer) 580 * This value represents the Serial Number for the received ASCONF 581 * Chunk that is acknowledged by this chunk. This value is copied 582 * from the received ASCONF Chunk. 583 * 584 * ASCONF Parameter Response: TLV format 585 * The ASCONF Parameter Response is used in the ASCONF-ACK to 586 * report status of ASCONF processing. 587 */ 588 typedef struct sctp_addip_param { 589 sctp_paramhdr_t param_hdr; 590 __be32 crr_id; 591 } __attribute__((packed)) sctp_addip_param_t; 592 593 typedef struct sctp_addiphdr { 594 __be32 serial; 595 __u8 params[0]; 596 } __attribute__((packed)) sctp_addiphdr_t; 597 598 typedef struct sctp_addip_chunk { 599 sctp_chunkhdr_t chunk_hdr; 600 sctp_addiphdr_t addip_hdr; 601 } __attribute__((packed)) sctp_addip_chunk_t; 602 603 #endif /* __LINUX_SCTP_H__ */ 604