xref: /freebsd/sys/netinet/sctp_header.h (revision 076ad2f836d5f49dc1375f1677335a48fe0d4b82)
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 /* heartbeat info parameter */
86 struct sctp_heartbeat_info_param {
87 	struct sctp_paramhdr ph;
88 	uint32_t time_value_1;
89 	uint32_t time_value_2;
90 	uint32_t random_value1;
91 	uint32_t random_value2;
92 	uint8_t addr_family;
93 	uint8_t addr_len;
94 	/* make sure that this structure is 4 byte aligned */
95 	uint8_t padding[2];
96 	char address[SCTP_ADDRMAX];
97 }                         SCTP_PACKED;
98 
99 
100 /* draft-ietf-tsvwg-prsctp */
101 /* PR-SCTP supported parameter */
102 struct sctp_prsctp_supported_param {
103 	struct sctp_paramhdr ph;
104 }                           SCTP_PACKED;
105 
106 
107 /* draft-ietf-tsvwg-addip-sctp */
108 struct sctp_asconf_paramhdr {	/* an ASCONF "parameter" */
109 	struct sctp_paramhdr ph;/* a SCTP parameter header */
110 	uint32_t correlation_id;/* correlation id for this param */
111 }                    SCTP_PACKED;
112 
113 struct sctp_asconf_addr_param {	/* an ASCONF address parameter */
114 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
115 	struct sctp_ipv6addr_param addrp;	/* max storage size */
116 }                      SCTP_PACKED;
117 
118 
119 struct sctp_asconf_tag_param {	/* an ASCONF NAT-Vtag parameter */
120 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
121 	uint32_t local_vtag;
122 	uint32_t remote_vtag;
123 }                     SCTP_PACKED;
124 
125 
126 struct sctp_asconf_addrv4_param {	/* an ASCONF address (v4) parameter */
127 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
128 	struct sctp_ipv4addr_param addrp;	/* max storage size */
129 }                        SCTP_PACKED;
130 
131 #define SCTP_MAX_SUPPORTED_EXT 256
132 
133 struct sctp_supported_chunk_types_param {
134 	struct sctp_paramhdr ph;/* type = 0x8008  len = x */
135 	uint8_t chunk_types[];
136 }                                SCTP_PACKED;
137 
138 
139 /*
140  * Structures for DATA chunks
141  */
142 struct sctp_data {
143 	uint32_t tsn;
144 	uint16_t sid;
145 	uint16_t ssn;
146 	uint32_t ppid;
147 	/* user data follows */
148 }         SCTP_PACKED;
149 
150 struct sctp_data_chunk {
151 	struct sctp_chunkhdr ch;
152 	struct sctp_data dp;
153 }               SCTP_PACKED;
154 
155 struct sctp_idata {
156 	uint32_t tsn;
157 	uint16_t sid;
158 	uint16_t reserved;	/* Where does the SSN go? */
159 	uint32_t mid;
160 	union {
161 		uint32_t ppid;
162 		uint32_t fsn;	/* Fragment Sequence Number */
163 	}     ppid_fsn;
164 	/* user data follows */
165 }          SCTP_PACKED;
166 
167 struct sctp_idata_chunk {
168 	struct sctp_chunkhdr ch;
169 	struct sctp_idata dp;
170 }                SCTP_PACKED;
171 
172 /*
173  * Structures for the control chunks
174  */
175 
176 /* Initiate (INIT)/Initiate Ack (INIT ACK) */
177 struct sctp_init {
178 	uint32_t initiate_tag;	/* initiate tag */
179 	uint32_t a_rwnd;	/* a_rwnd */
180 	uint16_t num_outbound_streams;	/* OS */
181 	uint16_t num_inbound_streams;	/* MIS */
182 	uint32_t initial_tsn;	/* I-TSN */
183 	/* optional param's follow */
184 }         SCTP_PACKED;
185 #define SCTP_IDENTIFICATION_SIZE 16
186 #define SCTP_ADDRESS_SIZE 4
187 #define SCTP_RESERVE_SPACE 6
188 /* state cookie header */
189 struct sctp_state_cookie {	/* this is our definition... */
190 	uint8_t identification[SCTP_IDENTIFICATION_SIZE];	/* id of who we are */
191 	struct timeval time_entered;	/* the time I built cookie */
192 	uint32_t cookie_life;	/* life I will award this cookie */
193 	uint32_t tie_tag_my_vtag;	/* my tag in old association */
194 
195 	uint32_t tie_tag_peer_vtag;	/* peers tag in old association */
196 	uint32_t peers_vtag;	/* peers tag in INIT (for quick ref) */
197 
198 	uint32_t my_vtag;	/* my tag in INIT-ACK (for quick ref) */
199 	uint32_t address[SCTP_ADDRESS_SIZE];	/* 4 ints/128 bits */
200 	uint32_t addr_type;	/* address type */
201 	uint32_t laddress[SCTP_ADDRESS_SIZE];	/* my local from address */
202 	uint32_t laddr_type;	/* my local from address type */
203 	uint32_t scope_id;	/* v6 scope id for link-locals */
204 
205 	uint16_t peerport;	/* port address of the peer in the INIT */
206 	uint16_t myport;	/* my port address used in the INIT */
207 	uint8_t ipv4_addr_legal;/* Are V4 addr legal? */
208 	uint8_t ipv6_addr_legal;/* Are V6 addr legal? */
209 	uint8_t local_scope;	/* IPv6 local scope flag */
210 	uint8_t site_scope;	/* IPv6 site scope flag */
211 
212 	uint8_t ipv4_scope;	/* IPv4 private addr scope */
213 	uint8_t loopback_scope;	/* loopback scope information */
214 	uint8_t reserved[SCTP_RESERVE_SPACE];	/* Align to 64 bits */
215 	/*
216 	 * at the end is tacked on the INIT chunk and the INIT-ACK chunk
217 	 * (minus the cookie).
218 	 */
219 }                 SCTP_PACKED;
220 
221 /* state cookie parameter */
222 struct sctp_state_cookie_param {
223 	struct sctp_paramhdr ph;
224 	struct sctp_state_cookie cookie;
225 }                       SCTP_PACKED;
226 
227 struct sctp_init_chunk {
228 	struct sctp_chunkhdr ch;
229 	struct sctp_init init;
230 }               SCTP_PACKED;
231 
232 struct sctp_init_msg {
233 	struct sctphdr sh;
234 	struct sctp_init_chunk msg;
235 }             SCTP_PACKED;
236 
237 /* ... used for both INIT and INIT ACK */
238 #define sctp_init_ack		sctp_init
239 #define sctp_init_ack_chunk	sctp_init_chunk
240 #define sctp_init_ack_msg	sctp_init_msg
241 
242 
243 /* Selective Ack (SACK) */
244 struct sctp_gap_ack_block {
245 	uint16_t start;		/* Gap Ack block start */
246 	uint16_t end;		/* Gap Ack block end */
247 }                  SCTP_PACKED;
248 
249 struct sctp_sack {
250 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
251 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
252 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
253 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
254 	/* struct sctp_gap_ack_block's follow */
255 	/* uint32_t duplicate_tsn's follow */
256 }         SCTP_PACKED;
257 
258 struct sctp_sack_chunk {
259 	struct sctp_chunkhdr ch;
260 	struct sctp_sack sack;
261 }               SCTP_PACKED;
262 
263 struct sctp_nr_sack {
264 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
265 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
266 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
267 	uint16_t num_nr_gap_ack_blks;	/* number of NR Gap Ack blocks */
268 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
269 	uint16_t reserved;	/* not currently used */
270 	/* struct sctp_gap_ack_block's follow */
271 	/* uint32_t duplicate_tsn's follow */
272 }            SCTP_PACKED;
273 
274 struct sctp_nr_sack_chunk {
275 	struct sctp_chunkhdr ch;
276 	struct sctp_nr_sack nr_sack;
277 }                  SCTP_PACKED;
278 
279 
280 /* Heartbeat Request (HEARTBEAT) */
281 struct sctp_heartbeat {
282 	struct sctp_heartbeat_info_param hb_info;
283 }              SCTP_PACKED;
284 
285 struct sctp_heartbeat_chunk {
286 	struct sctp_chunkhdr ch;
287 	struct sctp_heartbeat heartbeat;
288 }                    SCTP_PACKED;
289 
290 /* ... used for Heartbeat Ack (HEARTBEAT ACK) */
291 #define sctp_heartbeat_ack		sctp_heartbeat
292 #define sctp_heartbeat_ack_chunk	sctp_heartbeat_chunk
293 
294 
295 /* Abort Asssociation (ABORT) */
296 struct sctp_abort_chunk {
297 	struct sctp_chunkhdr ch;
298 	/* optional error cause may follow */
299 }                SCTP_PACKED;
300 
301 struct sctp_abort_msg {
302 	struct sctphdr sh;
303 	struct sctp_abort_chunk msg;
304 }              SCTP_PACKED;
305 
306 
307 /* Shutdown Association (SHUTDOWN) */
308 struct sctp_shutdown_chunk {
309 	struct sctp_chunkhdr ch;
310 	uint32_t cumulative_tsn_ack;
311 }                   SCTP_PACKED;
312 
313 
314 /* Shutdown Acknowledgment (SHUTDOWN ACK) */
315 struct sctp_shutdown_ack_chunk {
316 	struct sctp_chunkhdr ch;
317 }                       SCTP_PACKED;
318 
319 
320 /* Operation Error (ERROR) */
321 struct sctp_error_chunk {
322 	struct sctp_chunkhdr ch;
323 	/* optional error causes follow */
324 }                SCTP_PACKED;
325 
326 
327 /* Cookie Echo (COOKIE ECHO) */
328 struct sctp_cookie_echo_chunk {
329 	struct sctp_chunkhdr ch;
330 	struct sctp_state_cookie cookie;
331 }                      SCTP_PACKED;
332 
333 /* Cookie Acknowledgment (COOKIE ACK) */
334 struct sctp_cookie_ack_chunk {
335 	struct sctp_chunkhdr ch;
336 }                     SCTP_PACKED;
337 
338 /* Explicit Congestion Notification Echo (ECNE) */
339 struct old_sctp_ecne_chunk {
340 	struct sctp_chunkhdr ch;
341 	uint32_t tsn;
342 }                   SCTP_PACKED;
343 
344 struct sctp_ecne_chunk {
345 	struct sctp_chunkhdr ch;
346 	uint32_t tsn;
347 	uint32_t num_pkts_since_cwr;
348 }               SCTP_PACKED;
349 
350 /* Congestion Window Reduced (CWR) */
351 struct sctp_cwr_chunk {
352 	struct sctp_chunkhdr ch;
353 	uint32_t tsn;
354 }              SCTP_PACKED;
355 
356 /* Shutdown Complete (SHUTDOWN COMPLETE) */
357 struct sctp_shutdown_complete_chunk {
358 	struct sctp_chunkhdr ch;
359 }                            SCTP_PACKED;
360 
361 struct sctp_adaptation_layer_indication {
362 	struct sctp_paramhdr ph;
363 	uint32_t indication;
364 }                                SCTP_PACKED;
365 
366 /*
367  * draft-ietf-tsvwg-addip-sctp
368  */
369 /* Address/Stream Configuration Change (ASCONF) */
370 struct sctp_asconf_chunk {
371 	struct sctp_chunkhdr ch;
372 	uint32_t serial_number;
373 	/* lookup address parameter (mandatory) */
374 	/* asconf parameters follow */
375 }                 SCTP_PACKED;
376 
377 /* Address/Stream Configuration Acknowledge (ASCONF ACK) */
378 struct sctp_asconf_ack_chunk {
379 	struct sctp_chunkhdr ch;
380 	uint32_t serial_number;
381 	/* asconf parameters follow */
382 }                     SCTP_PACKED;
383 
384 /* draft-ietf-tsvwg-prsctp */
385 /* Forward Cumulative TSN (FORWARD TSN) */
386 struct sctp_forward_tsn_chunk {
387 	struct sctp_chunkhdr ch;
388 	uint32_t new_cumulative_tsn;
389 	/* stream/sequence pairs (sctp_strseq) follow */
390 }                      SCTP_PACKED;
391 
392 struct sctp_strseq {
393 	uint16_t sid;
394 	uint16_t ssn;
395 }           SCTP_PACKED;
396 
397 struct sctp_strseq_mid {
398 	uint16_t sid;
399 	uint16_t flags;
400 	uint32_t mid;
401 };
402 
403 struct sctp_forward_tsn_msg {
404 	struct sctphdr sh;
405 	struct sctp_forward_tsn_chunk msg;
406 }                    SCTP_PACKED;
407 
408 /* should be a multiple of 4 - 1 aka 3/7/11 etc. */
409 
410 #define SCTP_NUM_DB_TO_VERIFY 31
411 
412 struct sctp_chunk_desc {
413 	uint8_t chunk_type;
414 	uint8_t data_bytes[SCTP_NUM_DB_TO_VERIFY];
415 	uint32_t tsn_ifany;
416 }               SCTP_PACKED;
417 
418 
419 struct sctp_pktdrop_chunk {
420 	struct sctp_chunkhdr ch;
421 	uint32_t bottle_bw;
422 	uint32_t current_onq;
423 	uint16_t trunc_len;
424 	uint16_t reserved;
425 	uint8_t data[];
426 }                  SCTP_PACKED;
427 
428 /**********STREAM RESET STUFF ******************/
429 
430 struct sctp_stream_reset_request {
431 	struct sctp_paramhdr ph;
432 	uint32_t request_seq;
433 }                         SCTP_PACKED;
434 
435 struct sctp_stream_reset_out_request {
436 	struct sctp_paramhdr ph;
437 	uint32_t request_seq;	/* monotonically increasing seq no */
438 	uint32_t response_seq;	/* if a response, the resp seq no */
439 	uint32_t send_reset_at_tsn;	/* last TSN I assigned outbound */
440 	uint16_t list_of_streams[];	/* if not all list of streams */
441 }                             SCTP_PACKED;
442 
443 struct sctp_stream_reset_in_request {
444 	struct sctp_paramhdr ph;
445 	uint32_t request_seq;
446 	uint16_t list_of_streams[];	/* if not all list of streams */
447 }                            SCTP_PACKED;
448 
449 struct sctp_stream_reset_tsn_request {
450 	struct sctp_paramhdr ph;
451 	uint32_t request_seq;
452 }                             SCTP_PACKED;
453 
454 struct sctp_stream_reset_response {
455 	struct sctp_paramhdr ph;
456 	uint32_t response_seq;	/* if a response, the resp seq no */
457 	uint32_t result;
458 }                          SCTP_PACKED;
459 
460 struct sctp_stream_reset_response_tsn {
461 	struct sctp_paramhdr ph;
462 	uint32_t response_seq;	/* if a response, the resp seq no */
463 	uint32_t result;
464 	uint32_t senders_next_tsn;
465 	uint32_t receivers_next_tsn;
466 }                              SCTP_PACKED;
467 
468 struct sctp_stream_reset_add_strm {
469 	struct sctp_paramhdr ph;
470 	uint32_t request_seq;
471 	uint16_t number_of_streams;
472 	uint16_t reserved;
473 }                          SCTP_PACKED;
474 
475 #define SCTP_STREAM_RESET_RESULT_NOTHING_TO_DO   0x00000000	/* XXX: unused */
476 #define SCTP_STREAM_RESET_RESULT_PERFORMED       0x00000001
477 #define SCTP_STREAM_RESET_RESULT_DENIED          0x00000002
478 #define SCTP_STREAM_RESET_RESULT_ERR__WRONG_SSN  0x00000003	/* XXX: unused */
479 #define SCTP_STREAM_RESET_RESULT_ERR_IN_PROGRESS 0x00000004
480 #define SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO   0x00000005
481 #define SCTP_STREAM_RESET_RESULT_IN_PROGRESS     0x00000006	/* XXX: unused */
482 
483 /*
484  * convience structures, note that if you are making a request for specific
485  * streams then the request will need to be an overlay structure.
486  */
487 
488 struct sctp_stream_reset_tsn_req {
489 	struct sctp_chunkhdr ch;
490 	struct sctp_stream_reset_tsn_request sr_req;
491 }                         SCTP_PACKED;
492 
493 struct sctp_stream_reset_resp {
494 	struct sctp_chunkhdr ch;
495 	struct sctp_stream_reset_response sr_resp;
496 }                      SCTP_PACKED;
497 
498 /* respone only valid with a TSN request */
499 struct sctp_stream_reset_resp_tsn {
500 	struct sctp_chunkhdr ch;
501 	struct sctp_stream_reset_response_tsn sr_resp;
502 }                          SCTP_PACKED;
503 
504 /****************************************************/
505 
506 /*
507  * Authenticated chunks support draft-ietf-tsvwg-sctp-auth
508  */
509 
510 /* Should we make the max be 32? */
511 #define SCTP_RANDOM_MAX_SIZE 256
512 struct sctp_auth_random {
513 	struct sctp_paramhdr ph;/* type = 0x8002 */
514 	uint8_t random_data[];
515 }                SCTP_PACKED;
516 
517 struct sctp_auth_chunk_list {
518 	struct sctp_paramhdr ph;/* type = 0x8003 */
519 	uint8_t chunk_types[];
520 }                    SCTP_PACKED;
521 
522 struct sctp_auth_hmac_algo {
523 	struct sctp_paramhdr ph;/* type = 0x8004 */
524 	uint16_t hmac_ids[];
525 }                   SCTP_PACKED;
526 
527 struct sctp_auth_chunk {
528 	struct sctp_chunkhdr ch;
529 	uint16_t shared_key_id;
530 	uint16_t hmac_id;
531 	uint8_t hmac[];
532 }               SCTP_PACKED;
533 
534 /*
535  * we pre-reserve enough room for a ECNE or CWR AND a SACK with no missing
536  * pieces. If ENCE is missing we could have a couple of blocks. This way we
537  * optimize so we MOST likely can bundle a SACK/ECN with the smallest size
538  * data chunk I will split into. We could increase throughput slightly by
539  * taking out these two but the  24-sack/8-CWR i.e. 32 bytes I pre-reserve I
540  * feel is worth it for now.
541  */
542 #ifndef SCTP_MAX_OVERHEAD
543 #ifdef INET6
544 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
545 			   sizeof(struct sctphdr) + \
546 			   sizeof(struct sctp_ecne_chunk) + \
547 			   sizeof(struct sctp_sack_chunk) + \
548 			   sizeof(struct ip6_hdr))
549 
550 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
551 			   sizeof(struct sctphdr) + \
552 			   sizeof(struct ip6_hdr))
553 
554 
555 #define SCTP_MIN_OVERHEAD (sizeof(struct ip6_hdr) + \
556 			   sizeof(struct sctphdr))
557 
558 #else
559 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
560 			   sizeof(struct sctphdr) + \
561 			   sizeof(struct sctp_ecne_chunk) + \
562 			   sizeof(struct sctp_sack_chunk) + \
563 			   sizeof(struct ip))
564 
565 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
566 			   sizeof(struct sctphdr) + \
567 			   sizeof(struct ip))
568 
569 
570 #define SCTP_MIN_OVERHEAD (sizeof(struct ip) + \
571 			   sizeof(struct sctphdr))
572 
573 #endif				/* INET6 */
574 #endif				/* !SCTP_MAX_OVERHEAD */
575 
576 #define SCTP_MED_V4_OVERHEAD (sizeof(struct sctp_data_chunk) + \
577 			      sizeof(struct sctphdr) + \
578 			      sizeof(struct ip))
579 
580 #define SCTP_MIN_V4_OVERHEAD (sizeof(struct ip) + \
581 			      sizeof(struct sctphdr))
582 
583 #undef SCTP_PACKED
584 #endif				/* !__sctp_header_h__ */
585