xref: /freebsd/sys/netinet/sctp_header.h (revision d6eb98610fa65663bf0df4574b7cb2c5c4ffda71)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
5  * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
6  * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * a) Redistributions of source code must retain the above copyright notice,
12  *    this list of conditions and the following disclaimer.
13  *
14  * b) Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the distribution.
17  *
18  * c) Neither the name of Cisco Systems, Inc. nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
24  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
32  * THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #ifndef _NETINET_SCTP_HEADER_H_
39 #define _NETINET_SCTP_HEADER_H_
40 
41 #include <sys/time.h>
42 #include <netinet/sctp.h>
43 #include <netinet/sctp_constants.h>
44 
45 #define SCTP_PACKED __attribute__((packed))
46 
47 /*
48  * Parameter structures
49  */
50 struct sctp_ipv4addr_param {
51 	struct sctp_paramhdr ph;	/* type=SCTP_IPV4_PARAM_TYPE, len=8 */
52 	uint32_t addr;		/* IPV4 address */
53 }                   SCTP_PACKED;
54 
55 #define SCTP_V6_ADDR_BYTES 16
56 
57 
58 struct sctp_ipv6addr_param {
59 	struct sctp_paramhdr ph;	/* type=SCTP_IPV6_PARAM_TYPE, len=20 */
60 	uint8_t addr[SCTP_V6_ADDR_BYTES];	/* IPV6 address */
61 }                   SCTP_PACKED;
62 
63 /* Cookie Preservative */
64 struct sctp_cookie_perserve_param {
65 	struct sctp_paramhdr ph;	/* type=SCTP_COOKIE_PRESERVE, len=8 */
66 	uint32_t time;		/* time in ms to extend cookie */
67 }                          SCTP_PACKED;
68 
69 #define SCTP_ARRAY_MIN_LEN 1
70 /* Host Name Address */
71 struct sctp_host_name_param {
72 	struct sctp_paramhdr ph;	/* type=SCTP_HOSTNAME_ADDRESS */
73 	char name[SCTP_ARRAY_MIN_LEN];	/* host name */
74 }                    SCTP_PACKED;
75 
76 /*
77  * This is the maximum padded size of a s-a-p
78  * so paramheadr + 3 address types (6 bytes) + 2 byte pad = 12
79  */
80 #define SCTP_MAX_ADDR_PARAMS_SIZE 12
81 /* supported address type */
82 struct sctp_supported_addr_param {
83 	struct sctp_paramhdr ph;	/* type=SCTP_SUPPORTED_ADDRTYPE */
84 	uint16_t addr_type[2];	/* array of supported address types */
85 }                         SCTP_PACKED;
86 
87 /* heartbeat info parameter */
88 struct sctp_heartbeat_info_param {
89 	struct sctp_paramhdr ph;
90 	uint32_t time_value_1;
91 	uint32_t time_value_2;
92 	uint32_t random_value1;
93 	uint32_t random_value2;
94 	uint8_t addr_family;
95 	uint8_t addr_len;
96 	/* make sure that this structure is 4 byte aligned */
97 	uint8_t padding[2];
98 	char address[SCTP_ADDRMAX];
99 }                         SCTP_PACKED;
100 
101 
102 /* draft-ietf-tsvwg-prsctp */
103 /* PR-SCTP supported parameter */
104 struct sctp_prsctp_supported_param {
105 	struct sctp_paramhdr ph;
106 }                           SCTP_PACKED;
107 
108 
109 /* draft-ietf-tsvwg-addip-sctp */
110 struct sctp_asconf_paramhdr {	/* an ASCONF "parameter" */
111 	struct sctp_paramhdr ph;	/* a SCTP parameter header */
112 	uint32_t correlation_id;	/* correlation id for this param */
113 }                    SCTP_PACKED;
114 
115 struct sctp_asconf_addr_param {	/* an ASCONF address parameter */
116 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
117 	struct sctp_ipv6addr_param addrp;	/* max storage size */
118 }                      SCTP_PACKED;
119 
120 
121 struct sctp_asconf_tag_param {	/* an ASCONF NAT-Vtag parameter */
122 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
123 	uint32_t local_vtag;
124 	uint32_t remote_vtag;
125 }                     SCTP_PACKED;
126 
127 
128 struct sctp_asconf_addrv4_param {	/* an ASCONF address (v4) parameter */
129 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
130 	struct sctp_ipv4addr_param addrp;	/* max storage size */
131 }                        SCTP_PACKED;
132 
133 #define SCTP_MAX_SUPPORTED_EXT 256
134 
135 struct sctp_supported_chunk_types_param {
136 	struct sctp_paramhdr ph;	/* type = 0x8008  len = x */
137 	uint8_t chunk_types[];
138 }                                SCTP_PACKED;
139 
140 
141 /*
142  * Structures for DATA chunks
143  */
144 struct sctp_data {
145 	uint32_t tsn;
146 	uint16_t sid;
147 	uint16_t ssn;
148 	uint32_t ppid;
149 	/* user data follows */
150 }         SCTP_PACKED;
151 
152 struct sctp_data_chunk {
153 	struct sctp_chunkhdr ch;
154 	struct sctp_data dp;
155 }               SCTP_PACKED;
156 
157 struct sctp_idata {
158 	uint32_t tsn;
159 	uint16_t sid;
160 	uint16_t reserved;	/* Where does the SSN go? */
161 	uint32_t mid;
162 	union {
163 		uint32_t ppid;
164 		uint32_t fsn;	/* Fragment Sequence Number */
165 	}     ppid_fsn;
166 	/* user data follows */
167 }          SCTP_PACKED;
168 
169 struct sctp_idata_chunk {
170 	struct sctp_chunkhdr ch;
171 	struct sctp_idata dp;
172 }                SCTP_PACKED;
173 
174 /*
175  * Structures for the control chunks
176  */
177 
178 /* Initiate (INIT)/Initiate Ack (INIT ACK) */
179 struct sctp_init {
180 	uint32_t initiate_tag;	/* initiate tag */
181 	uint32_t a_rwnd;	/* a_rwnd */
182 	uint16_t num_outbound_streams;	/* OS */
183 	uint16_t num_inbound_streams;	/* MIS */
184 	uint32_t initial_tsn;	/* I-TSN */
185 	/* optional param's follow */
186 }         SCTP_PACKED;
187 #define SCTP_IDENTIFICATION_SIZE 16
188 #define SCTP_ADDRESS_SIZE 4
189 #define SCTP_RESERVE_SPACE 6
190 /* state cookie header */
191 struct sctp_state_cookie {	/* this is our definition... */
192 	uint8_t identification[SCTP_IDENTIFICATION_SIZE];	/* id of who we are */
193 	struct timeval time_entered;	/* the time I built cookie */
194 	uint32_t cookie_life;	/* life I will award this cookie */
195 	uint32_t tie_tag_my_vtag;	/* my tag in old association */
196 
197 	uint32_t tie_tag_peer_vtag;	/* peers tag in old association */
198 	uint32_t peers_vtag;	/* peers tag in INIT (for quick ref) */
199 
200 	uint32_t my_vtag;	/* my tag in INIT-ACK (for quick ref) */
201 	uint32_t address[SCTP_ADDRESS_SIZE];	/* 4 ints/128 bits */
202 	uint32_t addr_type;	/* address type */
203 	uint32_t laddress[SCTP_ADDRESS_SIZE];	/* my local from address */
204 	uint32_t laddr_type;	/* my local from address type */
205 	uint32_t scope_id;	/* v6 scope id for link-locals */
206 
207 	uint16_t peerport;	/* port address of the peer in the INIT */
208 	uint16_t myport;	/* my port address used in the INIT */
209 	uint8_t ipv4_addr_legal;	/* Are V4 addr legal? */
210 	uint8_t ipv6_addr_legal;	/* Are V6 addr legal? */
211 	uint8_t local_scope;	/* IPv6 local scope flag */
212 	uint8_t site_scope;	/* IPv6 site scope flag */
213 
214 	uint8_t ipv4_scope;	/* IPv4 private addr scope */
215 	uint8_t loopback_scope;	/* loopback scope information */
216 	uint8_t reserved[SCTP_RESERVE_SPACE];	/* Align to 64 bits */
217 	/*
218 	 * at the end is tacked on the INIT chunk and the INIT-ACK chunk
219 	 * (minus the cookie).
220 	 */
221 }                 SCTP_PACKED;
222 
223 /* state cookie parameter */
224 struct sctp_state_cookie_param {
225 	struct sctp_paramhdr ph;
226 	struct sctp_state_cookie cookie;
227 }                       SCTP_PACKED;
228 
229 struct sctp_init_chunk {
230 	struct sctp_chunkhdr ch;
231 	struct sctp_init init;
232 }               SCTP_PACKED;
233 
234 struct sctp_init_msg {
235 	struct sctphdr sh;
236 	struct sctp_init_chunk msg;
237 }             SCTP_PACKED;
238 
239 /* ... used for both INIT and INIT ACK */
240 #define sctp_init_ack		sctp_init
241 #define sctp_init_ack_chunk	sctp_init_chunk
242 #define sctp_init_ack_msg	sctp_init_msg
243 
244 
245 /* Selective Ack (SACK) */
246 struct sctp_gap_ack_block {
247 	uint16_t start;		/* Gap Ack block start */
248 	uint16_t end;		/* Gap Ack block end */
249 }                  SCTP_PACKED;
250 
251 struct sctp_sack {
252 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
253 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
254 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
255 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
256 	/* struct sctp_gap_ack_block's follow */
257 	/* uint32_t duplicate_tsn's follow */
258 }         SCTP_PACKED;
259 
260 struct sctp_sack_chunk {
261 	struct sctp_chunkhdr ch;
262 	struct sctp_sack sack;
263 }               SCTP_PACKED;
264 
265 struct sctp_nr_sack {
266 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
267 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
268 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
269 	uint16_t num_nr_gap_ack_blks;	/* number of NR Gap Ack blocks */
270 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
271 	uint16_t reserved;	/* not currently used */
272 	/* struct sctp_gap_ack_block's follow */
273 	/* uint32_t duplicate_tsn's follow */
274 }            SCTP_PACKED;
275 
276 struct sctp_nr_sack_chunk {
277 	struct sctp_chunkhdr ch;
278 	struct sctp_nr_sack nr_sack;
279 }                  SCTP_PACKED;
280 
281 
282 /* Heartbeat Request (HEARTBEAT) */
283 struct sctp_heartbeat {
284 	struct sctp_heartbeat_info_param hb_info;
285 }              SCTP_PACKED;
286 
287 struct sctp_heartbeat_chunk {
288 	struct sctp_chunkhdr ch;
289 	struct sctp_heartbeat heartbeat;
290 }                    SCTP_PACKED;
291 
292 /* ... used for Heartbeat Ack (HEARTBEAT ACK) */
293 #define sctp_heartbeat_ack		sctp_heartbeat
294 #define sctp_heartbeat_ack_chunk	sctp_heartbeat_chunk
295 
296 
297 /* Abort Asssociation (ABORT) */
298 struct sctp_abort_chunk {
299 	struct sctp_chunkhdr ch;
300 	/* optional error cause may follow */
301 }                SCTP_PACKED;
302 
303 struct sctp_abort_msg {
304 	struct sctphdr sh;
305 	struct sctp_abort_chunk msg;
306 }              SCTP_PACKED;
307 
308 
309 /* Shutdown Association (SHUTDOWN) */
310 struct sctp_shutdown_chunk {
311 	struct sctp_chunkhdr ch;
312 	uint32_t cumulative_tsn_ack;
313 }                   SCTP_PACKED;
314 
315 
316 /* Shutdown Acknowledgment (SHUTDOWN ACK) */
317 struct sctp_shutdown_ack_chunk {
318 	struct sctp_chunkhdr ch;
319 }                       SCTP_PACKED;
320 
321 
322 /* Operation Error (ERROR) */
323 struct sctp_error_chunk {
324 	struct sctp_chunkhdr ch;
325 	/* optional error causes follow */
326 }                SCTP_PACKED;
327 
328 
329 /* Cookie Echo (COOKIE ECHO) */
330 struct sctp_cookie_echo_chunk {
331 	struct sctp_chunkhdr ch;
332 	struct sctp_state_cookie cookie;
333 }                      SCTP_PACKED;
334 
335 /* Cookie Acknowledgment (COOKIE ACK) */
336 struct sctp_cookie_ack_chunk {
337 	struct sctp_chunkhdr ch;
338 }                     SCTP_PACKED;
339 
340 /* Explicit Congestion Notification Echo (ECNE) */
341 struct old_sctp_ecne_chunk {
342 	struct sctp_chunkhdr ch;
343 	uint32_t tsn;
344 }                   SCTP_PACKED;
345 
346 struct sctp_ecne_chunk {
347 	struct sctp_chunkhdr ch;
348 	uint32_t tsn;
349 	uint32_t num_pkts_since_cwr;
350 }               SCTP_PACKED;
351 
352 /* Congestion Window Reduced (CWR) */
353 struct sctp_cwr_chunk {
354 	struct sctp_chunkhdr ch;
355 	uint32_t tsn;
356 }              SCTP_PACKED;
357 
358 /* Shutdown Complete (SHUTDOWN COMPLETE) */
359 struct sctp_shutdown_complete_chunk {
360 	struct sctp_chunkhdr ch;
361 }                            SCTP_PACKED;
362 
363 struct sctp_adaptation_layer_indication {
364 	struct sctp_paramhdr ph;
365 	uint32_t indication;
366 }                                SCTP_PACKED;
367 
368 /*
369  * draft-ietf-tsvwg-addip-sctp
370  */
371 /* Address/Stream Configuration Change (ASCONF) */
372 struct sctp_asconf_chunk {
373 	struct sctp_chunkhdr ch;
374 	uint32_t serial_number;
375 	/* lookup address parameter (mandatory) */
376 	/* asconf parameters follow */
377 }                 SCTP_PACKED;
378 
379 /* Address/Stream Configuration Acknowledge (ASCONF ACK) */
380 struct sctp_asconf_ack_chunk {
381 	struct sctp_chunkhdr ch;
382 	uint32_t serial_number;
383 	/* asconf parameters follow */
384 }                     SCTP_PACKED;
385 
386 /* draft-ietf-tsvwg-prsctp */
387 /* Forward Cumulative TSN (FORWARD TSN) */
388 struct sctp_forward_tsn_chunk {
389 	struct sctp_chunkhdr ch;
390 	uint32_t new_cumulative_tsn;
391 	/* stream/sequence pairs (sctp_strseq) follow */
392 }                      SCTP_PACKED;
393 
394 struct sctp_strseq {
395 	uint16_t sid;
396 	uint16_t ssn;
397 }           SCTP_PACKED;
398 
399 struct sctp_strseq_mid {
400 	uint16_t sid;
401 	uint16_t flags;
402 	uint32_t mid;
403 };
404 
405 struct sctp_forward_tsn_msg {
406 	struct sctphdr sh;
407 	struct sctp_forward_tsn_chunk msg;
408 }                    SCTP_PACKED;
409 
410 /* should be a multiple of 4 - 1 aka 3/7/11 etc. */
411 
412 #define SCTP_NUM_DB_TO_VERIFY 31
413 
414 struct sctp_chunk_desc {
415 	uint8_t chunk_type;
416 	uint8_t data_bytes[SCTP_NUM_DB_TO_VERIFY];
417 	uint32_t tsn_ifany;
418 }               SCTP_PACKED;
419 
420 
421 struct sctp_pktdrop_chunk {
422 	struct sctp_chunkhdr ch;
423 	uint32_t bottle_bw;
424 	uint32_t current_onq;
425 	uint16_t trunc_len;
426 	uint16_t reserved;
427 	uint8_t data[];
428 }                  SCTP_PACKED;
429 
430 /**********STREAM RESET STUFF ******************/
431 
432 struct sctp_stream_reset_request {
433 	struct sctp_paramhdr ph;
434 	uint32_t request_seq;
435 }                         SCTP_PACKED;
436 
437 struct sctp_stream_reset_out_request {
438 	struct sctp_paramhdr ph;
439 	uint32_t request_seq;	/* monotonically increasing seq no */
440 	uint32_t response_seq;	/* if a response, the resp seq no */
441 	uint32_t send_reset_at_tsn;	/* last TSN I assigned outbound */
442 	uint16_t list_of_streams[];	/* if not all list of streams */
443 }                             SCTP_PACKED;
444 
445 struct sctp_stream_reset_in_request {
446 	struct sctp_paramhdr ph;
447 	uint32_t request_seq;
448 	uint16_t list_of_streams[];	/* if not all list of streams */
449 }                            SCTP_PACKED;
450 
451 struct sctp_stream_reset_tsn_request {
452 	struct sctp_paramhdr ph;
453 	uint32_t request_seq;
454 }                             SCTP_PACKED;
455 
456 struct sctp_stream_reset_response {
457 	struct sctp_paramhdr ph;
458 	uint32_t response_seq;	/* if a response, the resp seq no */
459 	uint32_t result;
460 }                          SCTP_PACKED;
461 
462 struct sctp_stream_reset_response_tsn {
463 	struct sctp_paramhdr ph;
464 	uint32_t response_seq;	/* if a response, the resp seq no */
465 	uint32_t result;
466 	uint32_t senders_next_tsn;
467 	uint32_t receivers_next_tsn;
468 }                              SCTP_PACKED;
469 
470 struct sctp_stream_reset_add_strm {
471 	struct sctp_paramhdr ph;
472 	uint32_t request_seq;
473 	uint16_t number_of_streams;
474 	uint16_t reserved;
475 }                          SCTP_PACKED;
476 
477 #define SCTP_STREAM_RESET_RESULT_NOTHING_TO_DO   0x00000000	/* XXX: unused */
478 #define SCTP_STREAM_RESET_RESULT_PERFORMED       0x00000001
479 #define SCTP_STREAM_RESET_RESULT_DENIED          0x00000002
480 #define SCTP_STREAM_RESET_RESULT_ERR__WRONG_SSN  0x00000003	/* XXX: unused */
481 #define SCTP_STREAM_RESET_RESULT_ERR_IN_PROGRESS 0x00000004
482 #define SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO   0x00000005
483 #define SCTP_STREAM_RESET_RESULT_IN_PROGRESS     0x00000006	/* XXX: unused */
484 
485 /*
486  * convience structures, note that if you are making a request for specific
487  * streams then the request will need to be an overlay structure.
488  */
489 
490 struct sctp_stream_reset_tsn_req {
491 	struct sctp_chunkhdr ch;
492 	struct sctp_stream_reset_tsn_request sr_req;
493 }                         SCTP_PACKED;
494 
495 struct sctp_stream_reset_resp {
496 	struct sctp_chunkhdr ch;
497 	struct sctp_stream_reset_response sr_resp;
498 }                      SCTP_PACKED;
499 
500 /* respone only valid with a TSN request */
501 struct sctp_stream_reset_resp_tsn {
502 	struct sctp_chunkhdr ch;
503 	struct sctp_stream_reset_response_tsn sr_resp;
504 }                          SCTP_PACKED;
505 
506 /****************************************************/
507 
508 /*
509  * Authenticated chunks support draft-ietf-tsvwg-sctp-auth
510  */
511 
512 /* Should we make the max be 32? */
513 #define SCTP_RANDOM_MAX_SIZE 256
514 struct sctp_auth_random {
515 	struct sctp_paramhdr ph;	/* type = 0x8002 */
516 	uint8_t random_data[];
517 }                SCTP_PACKED;
518 
519 struct sctp_auth_chunk_list {
520 	struct sctp_paramhdr ph;	/* type = 0x8003 */
521 	uint8_t chunk_types[];
522 }                    SCTP_PACKED;
523 
524 struct sctp_auth_hmac_algo {
525 	struct sctp_paramhdr ph;	/* type = 0x8004 */
526 	uint16_t hmac_ids[];
527 }                   SCTP_PACKED;
528 
529 struct sctp_auth_chunk {
530 	struct sctp_chunkhdr ch;
531 	uint16_t shared_key_id;
532 	uint16_t hmac_id;
533 	uint8_t hmac[];
534 }               SCTP_PACKED;
535 
536 /*
537  * we pre-reserve enough room for a ECNE or CWR AND a SACK with no missing
538  * pieces. If ENCE is missing we could have a couple of blocks. This way we
539  * optimize so we MOST likely can bundle a SACK/ECN with the smallest size
540  * data chunk I will split into. We could increase throughput slightly by
541  * taking out these two but the  24-sack/8-CWR i.e. 32 bytes I pre-reserve I
542  * feel is worth it for now.
543  */
544 #ifndef SCTP_MAX_OVERHEAD
545 #ifdef INET6
546 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
547 			   sizeof(struct sctphdr) + \
548 			   sizeof(struct sctp_ecne_chunk) + \
549 			   sizeof(struct sctp_sack_chunk) + \
550 			   sizeof(struct ip6_hdr))
551 
552 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
553 			   sizeof(struct sctphdr) + \
554 			   sizeof(struct ip6_hdr))
555 
556 
557 #define SCTP_MIN_OVERHEAD (sizeof(struct ip6_hdr) + \
558 			   sizeof(struct sctphdr))
559 
560 #else
561 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
562 			   sizeof(struct sctphdr) + \
563 			   sizeof(struct sctp_ecne_chunk) + \
564 			   sizeof(struct sctp_sack_chunk) + \
565 			   sizeof(struct ip))
566 
567 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
568 			   sizeof(struct sctphdr) + \
569 			   sizeof(struct ip))
570 
571 
572 #define SCTP_MIN_OVERHEAD (sizeof(struct ip) + \
573 			   sizeof(struct sctphdr))
574 
575 #endif				/* INET6 */
576 #endif				/* !SCTP_MAX_OVERHEAD */
577 
578 #define SCTP_MED_V4_OVERHEAD (sizeof(struct sctp_data_chunk) + \
579 			      sizeof(struct sctphdr) + \
580 			      sizeof(struct ip))
581 
582 #define SCTP_MIN_V4_OVERHEAD (sizeof(struct ip) + \
583 			      sizeof(struct sctphdr))
584 
585 #undef SCTP_PACKED
586 #endif				/* !__sctp_header_h__ */
587