xref: /freebsd/sys/netinet/sctp_header.h (revision b1f9167f94059fd55c630891d359bcff987bd7eb)
1 /*-
2  * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
3  * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
4  * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * a) Redistributions of source code must retain the above copyright notice,
10  *    this list of conditions and the following disclaimer.
11  *
12  * b) Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the distribution.
15  *
16  * c) Neither the name of Cisco Systems, Inc. nor the names of its
17  *    contributors may be used to endorse or promote products derived
18  *    from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
22  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
30  * THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #ifndef _NETINET_SCTP_HEADER_H_
37 #define _NETINET_SCTP_HEADER_H_
38 
39 #include <sys/time.h>
40 #include <netinet/sctp.h>
41 #include <netinet/sctp_constants.h>
42 
43 #define SCTP_PACKED __attribute__((packed))
44 
45 /*
46  * Parameter structures
47  */
48 struct sctp_ipv4addr_param {
49 	struct sctp_paramhdr ph;/* type=SCTP_IPV4_PARAM_TYPE, len=8 */
50 	uint32_t addr;		/* IPV4 address */
51 }                   SCTP_PACKED;
52 
53 #define SCTP_V6_ADDR_BYTES 16
54 
55 
56 struct sctp_ipv6addr_param {
57 	struct sctp_paramhdr ph;/* type=SCTP_IPV6_PARAM_TYPE, len=20 */
58 	uint8_t addr[SCTP_V6_ADDR_BYTES];	/* IPV6 address */
59 }                   SCTP_PACKED;
60 
61 /* Cookie Preservative */
62 struct sctp_cookie_perserve_param {
63 	struct sctp_paramhdr ph;/* type=SCTP_COOKIE_PRESERVE, len=8 */
64 	uint32_t time;		/* time in ms to extend cookie */
65 }                          SCTP_PACKED;
66 
67 #define SCTP_ARRAY_MIN_LEN 1
68 /* Host Name Address */
69 struct sctp_host_name_param {
70 	struct sctp_paramhdr ph;/* type=SCTP_HOSTNAME_ADDRESS */
71 	char name[SCTP_ARRAY_MIN_LEN];	/* host name */
72 }                    SCTP_PACKED;
73 
74 /*
75  * This is the maximum padded size of a s-a-p
76  * so paramheadr + 3 address types (6 bytes) + 2 byte pad = 12
77  */
78 #define SCTP_MAX_ADDR_PARAMS_SIZE 12
79 /* supported address type */
80 struct sctp_supported_addr_param {
81 	struct sctp_paramhdr ph;/* type=SCTP_SUPPORTED_ADDRTYPE */
82 	uint16_t addr_type[2];	/* array of supported address types */
83 }                         SCTP_PACKED;
84 
85 /* ECN parameter */
86 struct sctp_ecn_supported_param {
87 	struct sctp_paramhdr ph;/* type=SCTP_ECN_CAPABLE */
88 }                        SCTP_PACKED;
89 
90 
91 /* heartbeat info parameter */
92 struct sctp_heartbeat_info_param {
93 	struct sctp_paramhdr ph;
94 	uint32_t time_value_1;
95 	uint32_t time_value_2;
96 	uint32_t random_value1;
97 	uint32_t random_value2;
98 	uint8_t addr_family;
99 	uint8_t addr_len;
100 	/* make sure that this structure is 4 byte aligned */
101 	uint8_t padding[2];
102 	char address[SCTP_ADDRMAX];
103 }                         SCTP_PACKED;
104 
105 
106 /* draft-ietf-tsvwg-prsctp */
107 /* PR-SCTP supported parameter */
108 struct sctp_prsctp_supported_param {
109 	struct sctp_paramhdr ph;
110 }                           SCTP_PACKED;
111 
112 
113 /* draft-ietf-tsvwg-addip-sctp */
114 struct sctp_asconf_paramhdr {	/* an ASCONF "parameter" */
115 	struct sctp_paramhdr ph;/* a SCTP parameter header */
116 	uint32_t correlation_id;/* correlation id for this param */
117 }                    SCTP_PACKED;
118 
119 struct sctp_asconf_addr_param {	/* an ASCONF address parameter */
120 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
121 	struct sctp_ipv6addr_param addrp;	/* max storage size */
122 }                      SCTP_PACKED;
123 
124 
125 struct sctp_asconf_tag_param {	/* an ASCONF NAT-Vtag parameter */
126 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
127 	uint32_t local_vtag;
128 	uint32_t remote_vtag;
129 }                     SCTP_PACKED;
130 
131 
132 struct sctp_asconf_addrv4_param {	/* an ASCONF address (v4) parameter */
133 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
134 	struct sctp_ipv4addr_param addrp;	/* max storage size */
135 }                        SCTP_PACKED;
136 
137 #define SCTP_MAX_SUPPORTED_EXT 256
138 
139 struct sctp_supported_chunk_types_param {
140 	struct sctp_paramhdr ph;/* type = 0x8008  len = x */
141 	uint8_t chunk_types[];
142 }                                SCTP_PACKED;
143 
144 
145 /*
146  * Structures for DATA chunks
147  */
148 struct sctp_data {
149 	uint32_t tsn;
150 	uint16_t stream_id;
151 	uint16_t stream_sequence;
152 	uint32_t protocol_id;
153 	/* user data follows */
154 }         SCTP_PACKED;
155 
156 struct sctp_data_chunk {
157 	struct sctp_chunkhdr ch;
158 	struct sctp_data dp;
159 }               SCTP_PACKED;
160 
161 /*
162  * Structures for the control chunks
163  */
164 
165 /* Initiate (INIT)/Initiate Ack (INIT ACK) */
166 struct sctp_init {
167 	uint32_t initiate_tag;	/* initiate tag */
168 	uint32_t a_rwnd;	/* a_rwnd */
169 	uint16_t num_outbound_streams;	/* OS */
170 	uint16_t num_inbound_streams;	/* MIS */
171 	uint32_t initial_tsn;	/* I-TSN */
172 	/* optional param's follow */
173 }         SCTP_PACKED;
174 
175 #define SCTP_IDENTIFICATION_SIZE 16
176 #define SCTP_ADDRESS_SIZE 4
177 #define SCTP_RESERVE_SPACE 6
178 /* state cookie header */
179 struct sctp_state_cookie {	/* this is our definition... */
180 	uint8_t identification[SCTP_IDENTIFICATION_SIZE];	/* id of who we are */
181 	struct timeval time_entered;	/* the time I built cookie */
182 	uint32_t cookie_life;	/* life I will award this cookie */
183 	uint32_t tie_tag_my_vtag;	/* my tag in old association */
184 
185 	uint32_t tie_tag_peer_vtag;	/* peers tag in old association */
186 	uint32_t peers_vtag;	/* peers tag in INIT (for quick ref) */
187 
188 	uint32_t my_vtag;	/* my tag in INIT-ACK (for quick ref) */
189 	uint32_t address[SCTP_ADDRESS_SIZE];	/* 4 ints/128 bits */
190 	uint32_t addr_type;	/* address type */
191 	uint32_t laddress[SCTP_ADDRESS_SIZE];	/* my local from address */
192 	uint32_t laddr_type;	/* my local from address type */
193 	uint32_t scope_id;	/* v6 scope id for link-locals */
194 
195 	uint16_t peerport;	/* port address of the peer in the INIT */
196 	uint16_t myport;	/* my port address used in the INIT */
197 	uint8_t ipv4_addr_legal;/* Are V4 addr legal? */
198 	uint8_t ipv6_addr_legal;/* Are V6 addr legal? */
199 	uint8_t local_scope;	/* IPv6 local scope flag */
200 	uint8_t site_scope;	/* IPv6 site scope flag */
201 
202 	uint8_t ipv4_scope;	/* IPv4 private addr scope */
203 	uint8_t loopback_scope;	/* loopback scope information */
204 	uint8_t reserved[SCTP_RESERVE_SPACE];	/* Align to 64 bits */
205 	/*
206 	 * at the end is tacked on the INIT chunk and the INIT-ACK chunk
207 	 * (minus the cookie).
208 	 */
209 }                 SCTP_PACKED;
210 
211 
212 /* Used for NAT state error cause */
213 struct sctp_missing_nat_state {
214 	uint16_t cause;
215 	uint16_t length;
216 	uint8_t data[];
217 }                      SCTP_PACKED;
218 
219 
220 struct sctp_inv_mandatory_param {
221 	uint16_t cause;
222 	uint16_t length;
223 	uint32_t num_param;
224 	uint16_t param;
225 	/*
226 	 * We include this to 0 it since only a missing cookie will cause
227 	 * this error.
228 	 */
229 	uint16_t resv;
230 }                        SCTP_PACKED;
231 
232 struct sctp_unresolv_addr {
233 	uint16_t cause;
234 	uint16_t length;
235 	uint16_t addr_type;
236 	uint16_t reserved;	/* Only one invalid addr type */
237 }                  SCTP_PACKED;
238 
239 /* state cookie parameter */
240 struct sctp_state_cookie_param {
241 	struct sctp_paramhdr ph;
242 	struct sctp_state_cookie cookie;
243 }                       SCTP_PACKED;
244 
245 struct sctp_init_chunk {
246 	struct sctp_chunkhdr ch;
247 	struct sctp_init init;
248 }               SCTP_PACKED;
249 
250 struct sctp_init_msg {
251 	struct sctphdr sh;
252 	struct sctp_init_chunk msg;
253 }             SCTP_PACKED;
254 
255 /* ... used for both INIT and INIT ACK */
256 #define sctp_init_ack		sctp_init
257 #define sctp_init_ack_chunk	sctp_init_chunk
258 #define sctp_init_ack_msg	sctp_init_msg
259 
260 
261 /* Selective Ack (SACK) */
262 struct sctp_gap_ack_block {
263 	uint16_t start;		/* Gap Ack block start */
264 	uint16_t end;		/* Gap Ack block end */
265 }                  SCTP_PACKED;
266 
267 struct sctp_sack {
268 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
269 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
270 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
271 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
272 	/* struct sctp_gap_ack_block's follow */
273 	/* uint32_t duplicate_tsn's follow */
274 }         SCTP_PACKED;
275 
276 struct sctp_sack_chunk {
277 	struct sctp_chunkhdr ch;
278 	struct sctp_sack sack;
279 }               SCTP_PACKED;
280 
281 struct sctp_nr_sack {
282 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
283 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
284 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
285 	uint16_t num_nr_gap_ack_blks;	/* number of NR Gap Ack blocks */
286 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
287 	uint16_t reserved;	/* not currently used */
288 	/* struct sctp_gap_ack_block's follow */
289 	/* uint32_t duplicate_tsn's follow */
290 }            SCTP_PACKED;
291 
292 struct sctp_nr_sack_chunk {
293 	struct sctp_chunkhdr ch;
294 	struct sctp_nr_sack nr_sack;
295 }                  SCTP_PACKED;
296 
297 
298 /* Heartbeat Request (HEARTBEAT) */
299 struct sctp_heartbeat {
300 	struct sctp_heartbeat_info_param hb_info;
301 }              SCTP_PACKED;
302 
303 struct sctp_heartbeat_chunk {
304 	struct sctp_chunkhdr ch;
305 	struct sctp_heartbeat heartbeat;
306 }                    SCTP_PACKED;
307 
308 /* ... used for Heartbeat Ack (HEARTBEAT ACK) */
309 #define sctp_heartbeat_ack		sctp_heartbeat
310 #define sctp_heartbeat_ack_chunk	sctp_heartbeat_chunk
311 
312 
313 /* Abort Asssociation (ABORT) */
314 struct sctp_abort_chunk {
315 	struct sctp_chunkhdr ch;
316 	/* optional error cause may follow */
317 }                SCTP_PACKED;
318 
319 struct sctp_abort_msg {
320 	struct sctphdr sh;
321 	struct sctp_abort_chunk msg;
322 }              SCTP_PACKED;
323 
324 
325 /* Shutdown Association (SHUTDOWN) */
326 struct sctp_shutdown_chunk {
327 	struct sctp_chunkhdr ch;
328 	uint32_t cumulative_tsn_ack;
329 }                   SCTP_PACKED;
330 
331 
332 /* Shutdown Acknowledgment (SHUTDOWN ACK) */
333 struct sctp_shutdown_ack_chunk {
334 	struct sctp_chunkhdr ch;
335 }                       SCTP_PACKED;
336 
337 
338 /* Operation Error (ERROR) */
339 struct sctp_error_chunk {
340 	struct sctp_chunkhdr ch;
341 	/* optional error causes follow */
342 }                SCTP_PACKED;
343 
344 
345 /* Cookie Echo (COOKIE ECHO) */
346 struct sctp_cookie_echo_chunk {
347 	struct sctp_chunkhdr ch;
348 	struct sctp_state_cookie cookie;
349 }                      SCTP_PACKED;
350 
351 /* Cookie Acknowledgment (COOKIE ACK) */
352 struct sctp_cookie_ack_chunk {
353 	struct sctp_chunkhdr ch;
354 }                     SCTP_PACKED;
355 
356 /* Explicit Congestion Notification Echo (ECNE) */
357 struct old_sctp_ecne_chunk {
358 	struct sctp_chunkhdr ch;
359 	uint32_t tsn;
360 }                   SCTP_PACKED;
361 
362 struct sctp_ecne_chunk {
363 	struct sctp_chunkhdr ch;
364 	uint32_t tsn;
365 	uint32_t num_pkts_since_cwr;
366 }               SCTP_PACKED;
367 
368 /* Congestion Window Reduced (CWR) */
369 struct sctp_cwr_chunk {
370 	struct sctp_chunkhdr ch;
371 	uint32_t tsn;
372 }              SCTP_PACKED;
373 
374 /* Shutdown Complete (SHUTDOWN COMPLETE) */
375 struct sctp_shutdown_complete_chunk {
376 	struct sctp_chunkhdr ch;
377 }                            SCTP_PACKED;
378 
379 /* Oper error holding a stale cookie */
380 struct sctp_stale_cookie_msg {
381 	struct sctp_paramhdr ph;/* really an error cause */
382 	uint32_t time_usec;
383 }                     SCTP_PACKED;
384 
385 struct sctp_adaptation_layer_indication {
386 	struct sctp_paramhdr ph;
387 	uint32_t indication;
388 }                                SCTP_PACKED;
389 
390 struct sctp_cookie_while_shutting_down {
391 	struct sctphdr sh;
392 	struct sctp_chunkhdr ch;
393 	struct sctp_paramhdr ph;/* really an error cause */
394 }                               SCTP_PACKED;
395 
396 struct sctp_shutdown_complete_msg {
397 	struct sctphdr sh;
398 	struct sctp_shutdown_complete_chunk shut_cmp;
399 }                          SCTP_PACKED;
400 
401 /*
402  * draft-ietf-tsvwg-addip-sctp
403  */
404 /* Address/Stream Configuration Change (ASCONF) */
405 struct sctp_asconf_chunk {
406 	struct sctp_chunkhdr ch;
407 	uint32_t serial_number;
408 	/* lookup address parameter (mandatory) */
409 	/* asconf parameters follow */
410 }                 SCTP_PACKED;
411 
412 /* Address/Stream Configuration Acknowledge (ASCONF ACK) */
413 struct sctp_asconf_ack_chunk {
414 	struct sctp_chunkhdr ch;
415 	uint32_t serial_number;
416 	/* asconf parameters follow */
417 }                     SCTP_PACKED;
418 
419 /* draft-ietf-tsvwg-prsctp */
420 /* Forward Cumulative TSN (FORWARD TSN) */
421 struct sctp_forward_tsn_chunk {
422 	struct sctp_chunkhdr ch;
423 	uint32_t new_cumulative_tsn;
424 	/* stream/sequence pairs (sctp_strseq) follow */
425 }                      SCTP_PACKED;
426 
427 struct sctp_strseq {
428 	uint16_t stream;
429 	uint16_t sequence;
430 }           SCTP_PACKED;
431 
432 struct sctp_forward_tsn_msg {
433 	struct sctphdr sh;
434 	struct sctp_forward_tsn_chunk msg;
435 }                    SCTP_PACKED;
436 
437 /* should be a multiple of 4 - 1 aka 3/7/11 etc. */
438 
439 #define SCTP_NUM_DB_TO_VERIFY 31
440 
441 struct sctp_chunk_desc {
442 	uint8_t chunk_type;
443 	uint8_t data_bytes[SCTP_NUM_DB_TO_VERIFY];
444 	uint32_t tsn_ifany;
445 }               SCTP_PACKED;
446 
447 
448 struct sctp_pktdrop_chunk {
449 	struct sctp_chunkhdr ch;
450 	uint32_t bottle_bw;
451 	uint32_t current_onq;
452 	uint16_t trunc_len;
453 	uint16_t reserved;
454 	uint8_t data[];
455 }                  SCTP_PACKED;
456 
457 /**********STREAM RESET STUFF ******************/
458 
459 struct sctp_stream_reset_out_request {
460 	struct sctp_paramhdr ph;
461 	uint32_t request_seq;	/* monotonically increasing seq no */
462 	uint32_t response_seq;	/* if a response, the resp seq no */
463 	uint32_t send_reset_at_tsn;	/* last TSN I assigned outbound */
464 	uint16_t list_of_streams[];	/* if not all list of streams */
465 }                             SCTP_PACKED;
466 
467 struct sctp_stream_reset_in_request {
468 	struct sctp_paramhdr ph;
469 	uint32_t request_seq;
470 	uint16_t list_of_streams[];	/* if not all list of streams */
471 }                            SCTP_PACKED;
472 
473 
474 struct sctp_stream_reset_tsn_request {
475 	struct sctp_paramhdr ph;
476 	uint32_t request_seq;
477 }                             SCTP_PACKED;
478 
479 struct sctp_stream_reset_response {
480 	struct sctp_paramhdr ph;
481 	uint32_t response_seq;	/* if a response, the resp seq no */
482 	uint32_t result;
483 }                          SCTP_PACKED;
484 
485 struct sctp_stream_reset_response_tsn {
486 	struct sctp_paramhdr ph;
487 	uint32_t response_seq;	/* if a response, the resp seq no */
488 	uint32_t result;
489 	uint32_t senders_next_tsn;
490 	uint32_t receivers_next_tsn;
491 }                              SCTP_PACKED;
492 
493 struct sctp_stream_reset_add_strm {
494 	struct sctp_paramhdr ph;
495 	uint32_t request_seq;
496 	uint16_t number_of_streams;
497 	uint16_t reserved;
498 }                          SCTP_PACKED;
499 
500 #define SCTP_STREAM_RESET_RESULT_NOTHING_TO_DO   0x00000000	/* XXX: unused */
501 #define SCTP_STREAM_RESET_RESULT_PERFORMED       0x00000001
502 #define SCTP_STREAM_RESET_RESULT_DENIED          0x00000002
503 #define SCTP_STREAM_RESET_RESULT_ERR__WRONG_SSN  0x00000003	/* XXX: unused */
504 #define SCTP_STREAM_RESET_RESULT_ERR_IN_PROGRESS 0x00000004
505 #define SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO   0x00000005
506 #define SCTP_STREAM_RESET_RESULT_IN_PROGRESS     0x00000006	/* XXX: unused */
507 
508 /*
509  * convience structures, note that if you are making a request for specific
510  * streams then the request will need to be an overlay structure.
511  */
512 
513 struct sctp_stream_reset_tsn_req {
514 	struct sctp_chunkhdr ch;
515 	struct sctp_stream_reset_tsn_request sr_req;
516 }                         SCTP_PACKED;
517 
518 struct sctp_stream_reset_resp {
519 	struct sctp_chunkhdr ch;
520 	struct sctp_stream_reset_response sr_resp;
521 }                      SCTP_PACKED;
522 
523 /* respone only valid with a TSN request */
524 struct sctp_stream_reset_resp_tsn {
525 	struct sctp_chunkhdr ch;
526 	struct sctp_stream_reset_response_tsn sr_resp;
527 }                          SCTP_PACKED;
528 
529 /****************************************************/
530 
531 /*
532  * Authenticated chunks support draft-ietf-tsvwg-sctp-auth
533  */
534 
535 /* Should we make the max be 32? */
536 #define SCTP_RANDOM_MAX_SIZE 256
537 struct sctp_auth_random {
538 	struct sctp_paramhdr ph;/* type = 0x8002 */
539 	uint8_t random_data[];
540 }                SCTP_PACKED;
541 
542 struct sctp_auth_chunk_list {
543 	struct sctp_paramhdr ph;/* type = 0x8003 */
544 	uint8_t chunk_types[];
545 }                    SCTP_PACKED;
546 
547 struct sctp_auth_hmac_algo {
548 	struct sctp_paramhdr ph;/* type = 0x8004 */
549 	uint16_t hmac_ids[];
550 }                   SCTP_PACKED;
551 
552 struct sctp_auth_chunk {
553 	struct sctp_chunkhdr ch;
554 	uint16_t shared_key_id;
555 	uint16_t hmac_id;
556 	uint8_t hmac[];
557 }               SCTP_PACKED;
558 
559 struct sctp_auth_invalid_hmac {
560 	struct sctp_paramhdr ph;
561 	uint16_t hmac_id;
562 	uint16_t padding;
563 }                      SCTP_PACKED;
564 
565 /*
566  * we pre-reserve enough room for a ECNE or CWR AND a SACK with no missing
567  * pieces. If ENCE is missing we could have a couple of blocks. This way we
568  * optimize so we MOST likely can bundle a SACK/ECN with the smallest size
569  * data chunk I will split into. We could increase throughput slightly by
570  * taking out these two but the  24-sack/8-CWR i.e. 32 bytes I pre-reserve I
571  * feel is worth it for now.
572  */
573 #ifndef SCTP_MAX_OVERHEAD
574 #ifdef INET6
575 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
576 			   sizeof(struct sctphdr) + \
577 			   sizeof(struct sctp_ecne_chunk) + \
578 			   sizeof(struct sctp_sack_chunk) + \
579 			   sizeof(struct ip6_hdr))
580 
581 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
582 			   sizeof(struct sctphdr) + \
583 			   sizeof(struct ip6_hdr))
584 
585 
586 #define SCTP_MIN_OVERHEAD (sizeof(struct ip6_hdr) + \
587 			   sizeof(struct sctphdr))
588 
589 #else
590 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
591 			   sizeof(struct sctphdr) + \
592 			   sizeof(struct sctp_ecne_chunk) + \
593 			   sizeof(struct sctp_sack_chunk) + \
594 			   sizeof(struct ip))
595 
596 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
597 			   sizeof(struct sctphdr) + \
598 			   sizeof(struct ip))
599 
600 
601 #define SCTP_MIN_OVERHEAD (sizeof(struct ip) + \
602 			   sizeof(struct sctphdr))
603 
604 #endif				/* INET6 */
605 #endif				/* !SCTP_MAX_OVERHEAD */
606 
607 #define SCTP_MED_V4_OVERHEAD (sizeof(struct sctp_data_chunk) + \
608 			      sizeof(struct sctphdr) + \
609 			      sizeof(struct ip))
610 
611 #define SCTP_MIN_V4_OVERHEAD (sizeof(struct ip) + \
612 			      sizeof(struct sctphdr))
613 
614 #undef SCTP_PACKED
615 #endif				/* !__sctp_header_h__ */
616