xref: /linux/include/linux/sctp.h (revision d9e1cc087a55286fe028e0f078159b30d7da90bd)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* SCTP kernel reference 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 Intel Corp.
7  * Copyright (c) 2001 Nokia, Inc.
8  * Copyright (c) 2001 La Monte H.P. Yarroll
9  *
10  * This file is part of the SCTP kernel reference Implementation
11  *
12  * Various protocol defined 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  * Or submit a bug report through the following website:
19  *    http://www.sf.net/projects/lksctp
20  *
21  * Written or modified by:
22  *    La Monte H.P. Yarroll <piggy@acm.org>
23  *    Karl Knutson <karl@athena.chicago.il.us>
24  *    Jon Grimm <jgrimm@us.ibm.com>
25  *    Xingang Guo <xingang.guo@intel.com>
26  *    randall@sctp.chicago.il.us
27  *    kmorneau@cisco.com
28  *    qxie1@email.mot.com
29  *    Sridhar Samudrala <sri@us.ibm.com>
30  *    Kevin Gao <kevin.gao@intel.com>
31  *
32  * Any bugs reported given to us we will try to fix... any fixes shared will
33  * be incorporated into the next SCTP release.
34  */
35 #ifndef __LINUX_SCTP_H__
36 #define __LINUX_SCTP_H__
37 
38 #include <linux/in.h>		/* We need in_addr.  */
39 #include <linux/in6.h>		/* We need in6_addr.  */
40 #include <linux/skbuff.h>
41 
42 #include <uapi/linux/sctp.h>
43 
44 /* Section 3.1.  SCTP Common Header Format */
45 struct sctphdr {
46 	__be16 source;
47 	__be16 dest;
48 	__be32 vtag;
49 	__le32 checksum;
50 };
51 
52 static inline struct sctphdr *sctp_hdr(const struct sk_buff *skb)
53 {
54 	return (struct sctphdr *)skb_transport_header(skb);
55 }
56 
57 /* Section 3.2.  Chunk Field Descriptions. */
58 struct sctp_chunkhdr {
59 	__u8 type;
60 	__u8 flags;
61 	__be16 length;
62 };
63 
64 
65 /* Section 3.2.  Chunk Type Values.
66  * [Chunk Type] identifies the type of information contained in the Chunk
67  * Value field. It takes a value from 0 to 254. The value of 255 is
68  * reserved for future use as an extension field.
69  */
70 enum sctp_cid {
71 	SCTP_CID_DATA			= 0,
72         SCTP_CID_INIT			= 1,
73         SCTP_CID_INIT_ACK		= 2,
74         SCTP_CID_SACK			= 3,
75         SCTP_CID_HEARTBEAT		= 4,
76         SCTP_CID_HEARTBEAT_ACK		= 5,
77         SCTP_CID_ABORT			= 6,
78         SCTP_CID_SHUTDOWN		= 7,
79         SCTP_CID_SHUTDOWN_ACK		= 8,
80         SCTP_CID_ERROR			= 9,
81         SCTP_CID_COOKIE_ECHO		= 10,
82         SCTP_CID_COOKIE_ACK	        = 11,
83         SCTP_CID_ECN_ECNE		= 12,
84         SCTP_CID_ECN_CWR		= 13,
85         SCTP_CID_SHUTDOWN_COMPLETE	= 14,
86 
87 	/* AUTH Extension Section 4.1 */
88 	SCTP_CID_AUTH			= 0x0F,
89 
90 	/* sctp ndata 5.1. I-DATA */
91 	SCTP_CID_I_DATA			= 0x40,
92 
93 	/* PR-SCTP Sec 3.2 */
94 	SCTP_CID_FWD_TSN		= 0xC0,
95 
96 	/* Use hex, as defined in ADDIP sec. 3.1 */
97 	SCTP_CID_ASCONF			= 0xC1,
98 	SCTP_CID_I_FWD_TSN		= 0xC2,
99 	SCTP_CID_ASCONF_ACK		= 0x80,
100 	SCTP_CID_RECONF			= 0x82,
101 	SCTP_CID_PAD			= 0x84,
102 }; /* enum */
103 
104 
105 /* Section 3.2
106  *  Chunk Types are encoded such that the highest-order two bits specify
107  *  the action that must be taken if the processing endpoint does not
108  *  recognize the Chunk Type.
109  */
110 enum {
111 	SCTP_CID_ACTION_DISCARD     = 0x00,
112 	SCTP_CID_ACTION_DISCARD_ERR = 0x40,
113 	SCTP_CID_ACTION_SKIP        = 0x80,
114 	SCTP_CID_ACTION_SKIP_ERR    = 0xc0,
115 };
116 
117 enum { SCTP_CID_ACTION_MASK = 0xc0, };
118 
119 /* This flag is used in Chunk Flags for ABORT and SHUTDOWN COMPLETE.
120  *
121  * 3.3.7 Abort Association (ABORT) (6):
122  *    The T bit is set to 0 if the sender had a TCB that it destroyed.
123  *    If the sender did not have a TCB it should set this bit to 1.
124  */
125 enum { SCTP_CHUNK_FLAG_T = 0x01 };
126 
127 /*
128  *  Set the T bit
129  *
130  *      0                   1                   2                   3
131  *      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
132  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
133  *     |   Type = 14   |Reserved     |T|      Length = 4               |
134  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
135  *
136  * Chunk Flags: 8 bits
137  *
138  *   Reserved:  7 bits
139  *     Set to 0 on transmit and ignored on receipt.
140  *
141  *   T bit:  1 bit
142  *     The T bit is set to 0 if the sender had a TCB that it destroyed. If
143  *     the sender did NOT have a TCB it should set this bit to 1.
144  *
145  * Note: Special rules apply to this chunk for verification, please
146  * see Section 8.5.1 for details.
147  */
148 
149 #define sctp_test_T_bit(c)    ((c)->chunk_hdr->flags & SCTP_CHUNK_FLAG_T)
150 
151 /* RFC 2960
152  * Section 3.2.1 Optional/Variable-length Parmaeter Format.
153  */
154 
155 struct sctp_paramhdr {
156 	__be16 type;
157 	__be16 length;
158 };
159 
160 enum sctp_param {
161 
162 	/* RFC 2960 Section 3.3.5 */
163 	SCTP_PARAM_HEARTBEAT_INFO		= cpu_to_be16(1),
164 	/* RFC 2960 Section 3.3.2.1 */
165 	SCTP_PARAM_IPV4_ADDRESS			= cpu_to_be16(5),
166 	SCTP_PARAM_IPV6_ADDRESS			= cpu_to_be16(6),
167 	SCTP_PARAM_STATE_COOKIE			= cpu_to_be16(7),
168 	SCTP_PARAM_UNRECOGNIZED_PARAMETERS	= cpu_to_be16(8),
169 	SCTP_PARAM_COOKIE_PRESERVATIVE		= cpu_to_be16(9),
170 	SCTP_PARAM_HOST_NAME_ADDRESS		= cpu_to_be16(11),
171 	SCTP_PARAM_SUPPORTED_ADDRESS_TYPES	= cpu_to_be16(12),
172 	SCTP_PARAM_ECN_CAPABLE			= cpu_to_be16(0x8000),
173 
174 	/* AUTH Extension Section 3 */
175 	SCTP_PARAM_RANDOM			= cpu_to_be16(0x8002),
176 	SCTP_PARAM_CHUNKS			= cpu_to_be16(0x8003),
177 	SCTP_PARAM_HMAC_ALGO			= cpu_to_be16(0x8004),
178 
179 	/* Add-IP: Supported Extensions, Section 4.2 */
180 	SCTP_PARAM_SUPPORTED_EXT	= cpu_to_be16(0x8008),
181 
182 	/* PR-SCTP Sec 3.1 */
183 	SCTP_PARAM_FWD_TSN_SUPPORT	= cpu_to_be16(0xc000),
184 
185 	/* Add-IP Extension. Section 3.2 */
186 	SCTP_PARAM_ADD_IP		= cpu_to_be16(0xc001),
187 	SCTP_PARAM_DEL_IP		= cpu_to_be16(0xc002),
188 	SCTP_PARAM_ERR_CAUSE		= cpu_to_be16(0xc003),
189 	SCTP_PARAM_SET_PRIMARY		= cpu_to_be16(0xc004),
190 	SCTP_PARAM_SUCCESS_REPORT	= cpu_to_be16(0xc005),
191 	SCTP_PARAM_ADAPTATION_LAYER_IND = cpu_to_be16(0xc006),
192 
193 	/* RE-CONFIG. Section 4 */
194 	SCTP_PARAM_RESET_OUT_REQUEST		= cpu_to_be16(0x000d),
195 	SCTP_PARAM_RESET_IN_REQUEST		= cpu_to_be16(0x000e),
196 	SCTP_PARAM_RESET_TSN_REQUEST		= cpu_to_be16(0x000f),
197 	SCTP_PARAM_RESET_RESPONSE		= cpu_to_be16(0x0010),
198 	SCTP_PARAM_RESET_ADD_OUT_STREAMS	= cpu_to_be16(0x0011),
199 	SCTP_PARAM_RESET_ADD_IN_STREAMS		= cpu_to_be16(0x0012),
200 }; /* enum */
201 
202 
203 /* RFC 2960 Section 3.2.1
204  *  The Parameter Types are encoded such that the highest-order two bits
205  *  specify the action that must be taken if the processing endpoint does
206  *  not recognize the Parameter Type.
207  *
208  */
209 enum {
210 	SCTP_PARAM_ACTION_DISCARD     = cpu_to_be16(0x0000),
211 	SCTP_PARAM_ACTION_DISCARD_ERR = cpu_to_be16(0x4000),
212 	SCTP_PARAM_ACTION_SKIP        = cpu_to_be16(0x8000),
213 	SCTP_PARAM_ACTION_SKIP_ERR    = cpu_to_be16(0xc000),
214 };
215 
216 enum { SCTP_PARAM_ACTION_MASK = cpu_to_be16(0xc000), };
217 
218 /* RFC 2960 Section 3.3.1 Payload Data (DATA) (0) */
219 
220 struct sctp_datahdr {
221 	__be32 tsn;
222 	__be16 stream;
223 	__be16 ssn;
224 	__u32 ppid;
225 };
226 
227 struct sctp_data_chunk {
228 	struct sctp_chunkhdr chunk_hdr;
229 	struct sctp_datahdr data_hdr;
230 };
231 
232 struct sctp_idatahdr {
233 	__be32 tsn;
234 	__be16 stream;
235 	__be16 reserved;
236 	__be32 mid;
237 	union {
238 		__u32 ppid;
239 		__be32 fsn;
240 	};
241 	__u8 payload[0];
242 };
243 
244 struct sctp_idata_chunk {
245 	struct sctp_chunkhdr chunk_hdr;
246 	struct sctp_idatahdr data_hdr;
247 };
248 
249 /* DATA Chuck Specific Flags */
250 enum {
251 	SCTP_DATA_MIDDLE_FRAG	= 0x00,
252 	SCTP_DATA_LAST_FRAG	= 0x01,
253 	SCTP_DATA_FIRST_FRAG	= 0x02,
254 	SCTP_DATA_NOT_FRAG	= 0x03,
255 	SCTP_DATA_UNORDERED	= 0x04,
256 	SCTP_DATA_SACK_IMM	= 0x08,
257 };
258 enum { SCTP_DATA_FRAG_MASK = 0x03, };
259 
260 
261 /* RFC 2960 Section 3.3.2 Initiation (INIT) (1)
262  *
263  *  This chunk is used to initiate a SCTP association between two
264  *  endpoints.
265  */
266 struct sctp_inithdr {
267 	__be32 init_tag;
268 	__be32 a_rwnd;
269 	__be16 num_outbound_streams;
270 	__be16 num_inbound_streams;
271 	__be32 initial_tsn;
272 	/* __u8  params[]; */
273 };
274 
275 struct sctp_init_chunk {
276 	struct sctp_chunkhdr chunk_hdr;
277 	struct sctp_inithdr init_hdr;
278 };
279 
280 
281 /* Section 3.3.2.1. IPv4 Address Parameter (5) */
282 struct sctp_ipv4addr_param {
283 	struct sctp_paramhdr param_hdr;
284 	struct in_addr addr;
285 };
286 
287 /* Section 3.3.2.1. IPv6 Address Parameter (6) */
288 struct sctp_ipv6addr_param {
289 	struct sctp_paramhdr param_hdr;
290 	struct in6_addr addr;
291 };
292 
293 /* Section 3.3.2.1 Cookie Preservative (9) */
294 struct sctp_cookie_preserve_param {
295 	struct sctp_paramhdr param_hdr;
296 	__be32 lifespan_increment;
297 };
298 
299 /* Section 3.3.2.1 Host Name Address (11) */
300 struct sctp_hostname_param {
301 	struct sctp_paramhdr param_hdr;
302 	uint8_t hostname[];
303 };
304 
305 /* Section 3.3.2.1 Supported Address Types (12) */
306 struct sctp_supported_addrs_param {
307 	struct sctp_paramhdr param_hdr;
308 	__be16 types[];
309 };
310 
311 /* ADDIP Section 3.2.6 Adaptation Layer Indication */
312 struct sctp_adaptation_ind_param {
313 	struct sctp_paramhdr param_hdr;
314 	__be32 adaptation_ind;
315 };
316 
317 /* ADDIP Section 4.2.7 Supported Extensions Parameter */
318 struct sctp_supported_ext_param {
319 	struct sctp_paramhdr param_hdr;
320 	__u8 chunks[];
321 };
322 
323 /* AUTH Section 3.1 Random */
324 struct sctp_random_param {
325 	struct sctp_paramhdr param_hdr;
326 	__u8 random_val[];
327 };
328 
329 /* AUTH Section 3.2 Chunk List */
330 struct sctp_chunks_param {
331 	struct sctp_paramhdr param_hdr;
332 	__u8 chunks[];
333 };
334 
335 /* AUTH Section 3.3 HMAC Algorithm */
336 struct sctp_hmac_algo_param {
337 	struct sctp_paramhdr param_hdr;
338 	__be16 hmac_ids[];
339 };
340 
341 /* RFC 2960.  Section 3.3.3 Initiation Acknowledgement (INIT ACK) (2):
342  *   The INIT ACK chunk is used to acknowledge the initiation of an SCTP
343  *   association.
344  */
345 struct sctp_initack_chunk {
346 	struct sctp_chunkhdr chunk_hdr;
347 	struct sctp_inithdr init_hdr;
348 };
349 
350 /* Section 3.3.3.1 State Cookie (7) */
351 struct sctp_cookie_param {
352 	struct sctp_paramhdr p;
353 	__u8 body[];
354 };
355 
356 /* Section 3.3.3.1 Unrecognized Parameters (8) */
357 struct sctp_unrecognized_param {
358 	struct sctp_paramhdr param_hdr;
359 	struct sctp_paramhdr unrecognized;
360 };
361 
362 
363 
364 /*
365  * 3.3.4 Selective Acknowledgement (SACK) (3):
366  *
367  *  This chunk is sent to the peer endpoint to acknowledge received DATA
368  *  chunks and to inform the peer endpoint of gaps in the received
369  *  subsequences of DATA chunks as represented by their TSNs.
370  */
371 
372 struct sctp_gap_ack_block {
373 	__be16 start;
374 	__be16 end;
375 };
376 
377 union sctp_sack_variable {
378 	struct sctp_gap_ack_block gab;
379 	__be32 dup;
380 };
381 
382 struct sctp_sackhdr {
383 	__be32 cum_tsn_ack;
384 	__be32 a_rwnd;
385 	__be16 num_gap_ack_blocks;
386 	__be16 num_dup_tsns;
387 	/* union sctp_sack_variable variable[]; */
388 };
389 
390 struct sctp_sack_chunk {
391 	struct sctp_chunkhdr chunk_hdr;
392 	struct sctp_sackhdr sack_hdr;
393 };
394 
395 
396 /* RFC 2960.  Section 3.3.5 Heartbeat Request (HEARTBEAT) (4):
397  *
398  *  An endpoint should send this chunk to its peer endpoint to probe the
399  *  reachability of a particular destination transport address defined in
400  *  the present association.
401  */
402 
403 struct sctp_heartbeathdr {
404 	struct sctp_paramhdr info;
405 };
406 
407 struct sctp_heartbeat_chunk {
408 	struct sctp_chunkhdr chunk_hdr;
409 	struct sctp_heartbeathdr hb_hdr;
410 };
411 
412 
413 /* PAD chunk could be bundled with heartbeat chunk to probe pmtu */
414 struct sctp_pad_chunk {
415 	struct sctp_chunkhdr uh;
416 };
417 
418 
419 /* For the abort and shutdown ACK we must carry the init tag in the
420  * common header. Just the common header is all that is needed with a
421  * chunk descriptor.
422  */
423 struct sctp_abort_chunk {
424 	struct sctp_chunkhdr uh;
425 };
426 
427 
428 /* For the graceful shutdown we must carry the tag (in common header)
429  * and the highest consecutive acking value.
430  */
431 struct sctp_shutdownhdr {
432 	__be32 cum_tsn_ack;
433 };
434 
435 struct sctp_shutdown_chunk {
436 	struct sctp_chunkhdr chunk_hdr;
437 	struct sctp_shutdownhdr shutdown_hdr;
438 };
439 
440 /* RFC 2960.  Section 3.3.10 Operation Error (ERROR) (9) */
441 
442 struct sctp_errhdr {
443 	__be16 cause;
444 	__be16 length;
445 	/* __u8  variable[]; */
446 };
447 
448 struct sctp_operr_chunk {
449 	struct sctp_chunkhdr chunk_hdr;
450 	struct sctp_errhdr err_hdr;
451 };
452 
453 /* RFC 2960 3.3.10 - Operation Error
454  *
455  * Cause Code: 16 bits (unsigned integer)
456  *
457  *     Defines the type of error conditions being reported.
458  *    Cause Code
459  *     Value           Cause Code
460  *     ---------      ----------------
461  *      1              Invalid Stream Identifier
462  *      2              Missing Mandatory Parameter
463  *      3              Stale Cookie Error
464  *      4              Out of Resource
465  *      5              Unresolvable Address
466  *      6              Unrecognized Chunk Type
467  *      7              Invalid Mandatory Parameter
468  *      8              Unrecognized Parameters
469  *      9              No User Data
470  *     10              Cookie Received While Shutting Down
471  */
472 enum sctp_error {
473 
474 	SCTP_ERROR_NO_ERROR	   = cpu_to_be16(0x00),
475 	SCTP_ERROR_INV_STRM	   = cpu_to_be16(0x01),
476 	SCTP_ERROR_MISS_PARAM 	   = cpu_to_be16(0x02),
477 	SCTP_ERROR_STALE_COOKIE	   = cpu_to_be16(0x03),
478 	SCTP_ERROR_NO_RESOURCE 	   = cpu_to_be16(0x04),
479 	SCTP_ERROR_DNS_FAILED      = cpu_to_be16(0x05),
480 	SCTP_ERROR_UNKNOWN_CHUNK   = cpu_to_be16(0x06),
481 	SCTP_ERROR_INV_PARAM       = cpu_to_be16(0x07),
482 	SCTP_ERROR_UNKNOWN_PARAM   = cpu_to_be16(0x08),
483 	SCTP_ERROR_NO_DATA         = cpu_to_be16(0x09),
484 	SCTP_ERROR_COOKIE_IN_SHUTDOWN = cpu_to_be16(0x0a),
485 
486 
487 	/* SCTP Implementation Guide:
488 	 *  11  Restart of an association with new addresses
489 	 *  12  User Initiated Abort
490 	 *  13  Protocol Violation
491 	 *  14  Restart of an Association with New Encapsulation Port
492 	 */
493 
494 	SCTP_ERROR_RESTART         = cpu_to_be16(0x0b),
495 	SCTP_ERROR_USER_ABORT      = cpu_to_be16(0x0c),
496 	SCTP_ERROR_PROTO_VIOLATION = cpu_to_be16(0x0d),
497 	SCTP_ERROR_NEW_ENCAP_PORT  = cpu_to_be16(0x0e),
498 
499 	/* ADDIP Section 3.3  New Error Causes
500 	 *
501 	 * Four new Error Causes are added to the SCTP Operational Errors,
502 	 * primarily for use in the ASCONF-ACK chunk.
503 	 *
504 	 * Value          Cause Code
505 	 * ---------      ----------------
506 	 * 0x00A0          Request to Delete Last Remaining IP Address.
507 	 * 0x00A1          Operation Refused Due to Resource Shortage.
508 	 * 0x00A2          Request to Delete Source IP Address.
509 	 * 0x00A3          Association Aborted due to illegal ASCONF-ACK
510 	 * 0x00A4          Request refused - no authorization.
511 	 */
512 	SCTP_ERROR_DEL_LAST_IP	= cpu_to_be16(0x00A0),
513 	SCTP_ERROR_RSRC_LOW	= cpu_to_be16(0x00A1),
514 	SCTP_ERROR_DEL_SRC_IP	= cpu_to_be16(0x00A2),
515 	SCTP_ERROR_ASCONF_ACK   = cpu_to_be16(0x00A3),
516 	SCTP_ERROR_REQ_REFUSED	= cpu_to_be16(0x00A4),
517 
518 	/* AUTH Section 4.  New Error Cause
519 	 *
520 	 * This section defines a new error cause that will be sent if an AUTH
521 	 * chunk is received with an unsupported HMAC identifier.
522 	 * illustrates the new error cause.
523 	 *
524 	 * Cause Code      Error Cause Name
525 	 * --------------------------------------------------------------
526 	 * 0x0105          Unsupported HMAC Identifier
527 	 */
528 	 SCTP_ERROR_UNSUP_HMAC	= cpu_to_be16(0x0105)
529 };
530 
531 
532 
533 /* RFC 2960.  Appendix A.  Explicit Congestion Notification.
534  *   Explicit Congestion Notification Echo (ECNE) (12)
535  */
536 struct sctp_ecnehdr {
537 	__be32 lowest_tsn;
538 };
539 
540 struct sctp_ecne_chunk {
541 	struct sctp_chunkhdr chunk_hdr;
542 	struct sctp_ecnehdr ence_hdr;
543 };
544 
545 /* RFC 2960.  Appendix A.  Explicit Congestion Notification.
546  *   Congestion Window Reduced (CWR) (13)
547  */
548 struct sctp_cwrhdr {
549 	__be32 lowest_tsn;
550 };
551 
552 /* PR-SCTP
553  * 3.2 Forward Cumulative TSN Chunk Definition (FORWARD TSN)
554  *
555  * Forward Cumulative TSN chunk has the following format:
556  *
557  *        0                   1                   2                   3
558  *        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
559  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
560  *      |   Type = 192  |  Flags = 0x00 |        Length = Variable      |
561  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
562  *      |                      New Cumulative TSN                       |
563  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
564  *      |         Stream-1              |       Stream Sequence-1       |
565  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
566  *      \                                                               /
567  *      /                                                               \
568  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
569  *      |         Stream-N              |       Stream Sequence-N       |
570  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
571  *
572  *      Chunk Flags:
573  *
574  *        Set to all zeros on transmit and ignored on receipt.
575  *
576  *      New Cumulative TSN: 32 bit u_int
577  *
578  *       This indicates the new cumulative TSN to the data receiver. Upon
579  *       the reception of this value, the data receiver MUST consider
580  *       any missing TSNs earlier than or equal to this value as received
581  *       and stop reporting them as gaps in any subsequent SACKs.
582  *
583  *      Stream-N: 16 bit u_int
584  *
585  *       This field holds a stream number that was skipped by this
586  *       FWD-TSN.
587  *
588  *      Stream Sequence-N: 16 bit u_int
589  *       This field holds the sequence number associated with the stream
590  *       that was skipped. The stream sequence field holds the largest stream
591  *       sequence number in this stream being skipped.  The receiver of
592  *       the FWD-TSN's can use the Stream-N and Stream Sequence-N fields
593  *       to enable delivery of any stranded TSN's that remain on the stream
594  *       re-ordering queues. This field MUST NOT report TSN's corresponding
595  *       to DATA chunk that are marked as unordered. For ordered DATA
596  *       chunks this field MUST be filled in.
597  */
598 struct sctp_fwdtsn_skip {
599 	__be16 stream;
600 	__be16 ssn;
601 };
602 
603 struct sctp_fwdtsn_hdr {
604 	__be32 new_cum_tsn;
605 	/* struct sctp_fwdtsn_skip skip[]; */
606 };
607 
608 struct sctp_fwdtsn_chunk {
609 	struct sctp_chunkhdr chunk_hdr;
610 	struct sctp_fwdtsn_hdr fwdtsn_hdr;
611 };
612 
613 struct sctp_ifwdtsn_skip {
614 	__be16 stream;
615 	__u8 reserved;
616 	__u8 flags;
617 	__be32 mid;
618 };
619 
620 struct sctp_ifwdtsn_hdr {
621 	__be32 new_cum_tsn;
622 	/* struct sctp_ifwdtsn_skip skip[]; */
623 };
624 
625 struct sctp_ifwdtsn_chunk {
626 	struct sctp_chunkhdr chunk_hdr;
627 	struct sctp_ifwdtsn_hdr fwdtsn_hdr;
628 };
629 
630 /* ADDIP
631  * Section 3.1.1 Address Configuration Change Chunk (ASCONF)
632  *
633  * 	Serial Number: 32 bits (unsigned integer)
634  *	This value represents a Serial Number for the ASCONF Chunk. The
635  *	valid range of Serial Number is from 0 to 2^32-1.
636  *	Serial Numbers wrap back to 0 after reaching 2^32 -1.
637  *
638  *	Address Parameter: 8 or 20 bytes (depending on type)
639  *	The address is an address of the sender of the ASCONF chunk,
640  *	the address MUST be considered part of the association by the
641  *	peer endpoint. This field may be used by the receiver of the
642  *	ASCONF to help in finding the association. This parameter MUST
643  *	be present in every ASCONF message i.e. it is a mandatory TLV
644  *	parameter.
645  *
646  *	ASCONF Parameter: TLV format
647  *	Each Address configuration change is represented by a TLV
648  *	parameter as defined in Section 3.2. One or more requests may
649  *	be present in an ASCONF Chunk.
650  *
651  * Section 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
652  *
653  *	Serial Number: 32 bits (unsigned integer)
654  *	This value represents the Serial Number for the received ASCONF
655  *	Chunk that is acknowledged by this chunk. This value is copied
656  *	from the received ASCONF Chunk.
657  *
658  *	ASCONF Parameter Response: TLV format
659  *	The ASCONF Parameter Response is used in the ASCONF-ACK to
660  *	report status of ASCONF processing.
661  */
662 struct sctp_addip_param {
663 	struct sctp_paramhdr param_hdr;
664 	__be32 crr_id;
665 };
666 
667 struct sctp_addiphdr {
668 	__be32	serial;
669 	/* __u8	params[]; */
670 };
671 
672 struct sctp_addip_chunk {
673 	struct sctp_chunkhdr chunk_hdr;
674 	struct sctp_addiphdr addip_hdr;
675 };
676 
677 /* AUTH
678  * Section 4.1  Authentication Chunk (AUTH)
679  *
680  *   This chunk is used to hold the result of the HMAC calculation.
681  *
682  *    0                   1                   2                   3
683  *    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
684  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
685  *   | Type = 0x0F   |   Flags=0     |             Length            |
686  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
687  *   |     Shared Key Identifier     |   HMAC Identifier             |
688  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
689  *   |                                                               |
690  *   \                             HMAC                              /
691  *   /                                                               \
692  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
693  *
694  *   Type: 1 byte (unsigned integer)
695  *   	This value MUST be set to 0x0F for  all AUTH-chunks.
696  *
697  *   Flags: 1 byte (unsigned integer)
698  *	Set to zero on transmit and ignored on receipt.
699  *
700  *   Length: 2 bytes (unsigned integer)
701  *   	This value holds the length of the HMAC in bytes plus 8.
702  *
703  *  Shared Key Identifier: 2 bytes (unsigned integer)
704  *	This value describes which endpoint pair shared key is used.
705  *
706  *   HMAC Identifier: 2 bytes (unsigned integer)
707  *   	This value describes which message digest is being used.  Table 2
708  *	shows the currently defined values.
709  *
710  *    The following Table 2 shows the currently defined values for HMAC
711  *       identifiers.
712  *
713  *	 +-----------------+--------------------------+
714  *	 | HMAC Identifier | Message Digest Algorithm |
715  *	 +-----------------+--------------------------+
716  *	 | 0               | Reserved                 |
717  *	 | 1               | SHA-1 defined in [8]     |
718  *	 | 2               | Reserved                 |
719  *	 | 3               | SHA-256 defined in [8]   |
720  *	 +-----------------+--------------------------+
721  *
722  *
723  *   HMAC: n bytes (unsigned integer) This hold the result of the HMAC
724  *      calculation.
725  */
726 struct sctp_authhdr {
727 	__be16 shkey_id;
728 	__be16 hmac_id;
729 	/* __u8   hmac[]; */
730 };
731 
732 struct sctp_auth_chunk {
733 	struct sctp_chunkhdr chunk_hdr;
734 	struct sctp_authhdr auth_hdr;
735 };
736 
737 struct sctp_infox {
738 	struct sctp_info *sctpinfo;
739 	struct sctp_association *asoc;
740 };
741 
742 struct sctp_reconf_chunk {
743 	struct sctp_chunkhdr chunk_hdr;
744 	/* __u8 params[]; */
745 };
746 
747 struct sctp_strreset_outreq {
748 	struct sctp_paramhdr param_hdr;
749 	__be32 request_seq;
750 	__be32 response_seq;
751 	__be32 send_reset_at_tsn;
752 	__be16 list_of_streams[];
753 };
754 
755 struct sctp_strreset_inreq {
756 	struct sctp_paramhdr param_hdr;
757 	__be32 request_seq;
758 	__be16 list_of_streams[];
759 };
760 
761 struct sctp_strreset_tsnreq {
762 	struct sctp_paramhdr param_hdr;
763 	__be32 request_seq;
764 };
765 
766 struct sctp_strreset_addstrm {
767 	struct sctp_paramhdr param_hdr;
768 	__be32 request_seq;
769 	__be16 number_of_streams;
770 	__be16 reserved;
771 };
772 
773 enum {
774 	SCTP_STRRESET_NOTHING_TO_DO	= 0x00,
775 	SCTP_STRRESET_PERFORMED		= 0x01,
776 	SCTP_STRRESET_DENIED		= 0x02,
777 	SCTP_STRRESET_ERR_WRONG_SSN	= 0x03,
778 	SCTP_STRRESET_ERR_IN_PROGRESS	= 0x04,
779 	SCTP_STRRESET_ERR_BAD_SEQNO	= 0x05,
780 	SCTP_STRRESET_IN_PROGRESS	= 0x06,
781 };
782 
783 struct sctp_strreset_resp {
784 	struct sctp_paramhdr param_hdr;
785 	__be32 response_seq;
786 	__be32 result;
787 };
788 
789 struct sctp_strreset_resptsn {
790 	struct sctp_paramhdr param_hdr;
791 	__be32 response_seq;
792 	__be32 result;
793 	__be32 senders_next_tsn;
794 	__be32 receivers_next_tsn;
795 };
796 
797 enum {
798 	SCTP_DSCP_SET_MASK = 0x1,
799 	SCTP_DSCP_VAL_MASK = 0xfc,
800 	SCTP_FLOWLABEL_SET_MASK = 0x100000,
801 	SCTP_FLOWLABEL_VAL_MASK = 0xfffff
802 };
803 
804 /* UDP Encapsulation
805  * draft-tuexen-tsvwg-sctp-udp-encaps-cons-03.html#section-4-4
806  *
807  *   The error cause indicating an "Restart of an Association with
808  *   New Encapsulation Port"
809  *
810  * 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
811  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
812  * |        Cause Code = 14        |       Cause Length = 8        |
813  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
814  * |   Current Encapsulation Port  |     New Encapsulation Port    |
815  * +-------------------------------+-------------------------------+
816  */
817 struct sctp_new_encap_port_hdr {
818 	__be16 cur_port;
819 	__be16 new_port;
820 };
821 
822 /* Round an int up to the next multiple of 4.  */
823 #define SCTP_PAD4(s) (((s)+3)&~3)
824 /* Truncate to the previous multiple of 4.  */
825 #define SCTP_TRUNC4(s) ((s)&~3)
826 
827 #endif /* __LINUX_SCTP_H__ */
828