sctp_header.h revision 228031
1/*-
2 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
3 * Copyright (c) 2008-2011, by Randall Stewart. All rights reserved.
4 * Copyright (c) 2008-2011, 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/* $KAME: sctp_header.h,v 1.14 2005/03/06 16:04:17 itojun Exp $	 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: head/sys/netinet/sctp_header.h 228031 2011-11-27 17:51:13Z tuexen $");
37
38#ifndef __sctp_header_h__
39#define __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 */
50struct 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
58struct 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 */
64struct 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 */
71struct 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 */
82struct 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/* ECN parameter */
88struct sctp_ecn_supported_param {
89	struct sctp_paramhdr ph;/* type=SCTP_ECN_CAPABLE */
90}                        SCTP_PACKED;
91
92
93/* heartbeat info parameter */
94struct sctp_heartbeat_info_param {
95	struct sctp_paramhdr ph;
96	uint32_t time_value_1;
97	uint32_t time_value_2;
98	uint32_t random_value1;
99	uint32_t random_value2;
100	uint8_t addr_family;
101	uint8_t addr_len;
102	/* make sure that this structure is 4 byte aligned */
103	uint8_t padding[2];
104	char address[SCTP_ADDRMAX];
105}                         SCTP_PACKED;
106
107
108/* draft-ietf-tsvwg-prsctp */
109/* PR-SCTP supported parameter */
110struct sctp_prsctp_supported_param {
111	struct sctp_paramhdr ph;
112}                           SCTP_PACKED;
113
114
115/* draft-ietf-tsvwg-addip-sctp */
116struct sctp_asconf_paramhdr {	/* an ASCONF "parameter" */
117	struct sctp_paramhdr ph;/* a SCTP parameter header */
118	uint32_t correlation_id;/* correlation id for this param */
119}                    SCTP_PACKED;
120
121struct sctp_asconf_addr_param {	/* an ASCONF address parameter */
122	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
123	struct sctp_ipv6addr_param addrp;	/* max storage size */
124}                      SCTP_PACKED;
125
126
127struct sctp_asconf_tag_param {	/* an ASCONF NAT-Vtag parameter */
128	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
129	uint32_t local_vtag;
130	uint32_t remote_vtag;
131}                     SCTP_PACKED;
132
133
134struct sctp_asconf_addrv4_param {	/* an ASCONF address (v4) parameter */
135	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
136	struct sctp_ipv4addr_param addrp;	/* max storage size */
137}                        SCTP_PACKED;
138
139#define SCTP_MAX_SUPPORTED_EXT 256
140
141struct sctp_supported_chunk_types_param {
142	struct sctp_paramhdr ph;/* type = 0x8008  len = x */
143	uint8_t chunk_types[];
144}                                SCTP_PACKED;
145
146
147/*
148 * Structures for DATA chunks
149 */
150struct sctp_data {
151	uint32_t tsn;
152	uint16_t stream_id;
153	uint16_t stream_sequence;
154	uint32_t protocol_id;
155	/* user data follows */
156}         SCTP_PACKED;
157
158struct sctp_data_chunk {
159	struct sctp_chunkhdr ch;
160	struct sctp_data dp;
161}               SCTP_PACKED;
162
163/*
164 * Structures for the control chunks
165 */
166
167/* Initiate (INIT)/Initiate Ack (INIT ACK) */
168struct sctp_init {
169	uint32_t initiate_tag;	/* initiate tag */
170	uint32_t a_rwnd;	/* a_rwnd */
171	uint16_t num_outbound_streams;	/* OS */
172	uint16_t num_inbound_streams;	/* MIS */
173	uint32_t initial_tsn;	/* I-TSN */
174	/* optional param's follow */
175}         SCTP_PACKED;
176
177#define SCTP_IDENTIFICATION_SIZE 16
178#define SCTP_ADDRESS_SIZE 4
179#define SCTP_RESERVE_SPACE 6
180/* state cookie header */
181struct sctp_state_cookie {	/* this is our definition... */
182	uint8_t identification[SCTP_IDENTIFICATION_SIZE];	/* id of who we are */
183	struct timeval time_entered;	/* the time I built cookie */
184	uint32_t cookie_life;	/* life I will award this cookie */
185	uint32_t tie_tag_my_vtag;	/* my tag in old association */
186
187	uint32_t tie_tag_peer_vtag;	/* peers tag in old association */
188	uint32_t peers_vtag;	/* peers tag in INIT (for quick ref) */
189
190	uint32_t my_vtag;	/* my tag in INIT-ACK (for quick ref) */
191	uint32_t address[SCTP_ADDRESS_SIZE];	/* 4 ints/128 bits */
192	uint32_t addr_type;	/* address type */
193	uint32_t laddress[SCTP_ADDRESS_SIZE];	/* my local from address */
194	uint32_t laddr_type;	/* my local from address type */
195	uint32_t scope_id;	/* v6 scope id for link-locals */
196
197	uint16_t peerport;	/* port address of the peer in the INIT */
198	uint16_t myport;	/* my port address used in the INIT */
199	uint8_t ipv4_addr_legal;/* Are V4 addr legal? */
200	uint8_t ipv6_addr_legal;/* Are V6 addr legal? */
201	uint8_t local_scope;	/* IPv6 local scope flag */
202	uint8_t site_scope;	/* IPv6 site scope flag */
203
204	uint8_t ipv4_scope;	/* IPv4 private addr scope */
205	uint8_t loopback_scope;	/* loopback scope information */
206	uint8_t reserved[SCTP_RESERVE_SPACE];	/* Align to 64 bits */
207	/*
208	 * at the end is tacked on the INIT chunk and the INIT-ACK chunk
209	 * (minus the cookie).
210	 */
211}                 SCTP_PACKED;
212
213
214/* Used for NAT state error cause */
215struct sctp_missing_nat_state {
216	uint16_t cause;
217	uint16_t length;
218	uint8_t data[];
219}                      SCTP_PACKED;
220
221
222struct sctp_inv_mandatory_param {
223	uint16_t cause;
224	uint16_t length;
225	uint32_t num_param;
226	uint16_t param;
227	/*
228	 * We include this to 0 it since only a missing cookie will cause
229	 * this error.
230	 */
231	uint16_t resv;
232}                        SCTP_PACKED;
233
234struct sctp_unresolv_addr {
235	uint16_t cause;
236	uint16_t length;
237	uint16_t addr_type;
238	uint16_t reserved;	/* Only one invalid addr type */
239}                  SCTP_PACKED;
240
241/* state cookie parameter */
242struct sctp_state_cookie_param {
243	struct sctp_paramhdr ph;
244	struct sctp_state_cookie cookie;
245}                       SCTP_PACKED;
246
247struct sctp_init_chunk {
248	struct sctp_chunkhdr ch;
249	struct sctp_init init;
250}               SCTP_PACKED;
251
252struct sctp_init_msg {
253	struct sctphdr sh;
254	struct sctp_init_chunk msg;
255}             SCTP_PACKED;
256
257/* ... used for both INIT and INIT ACK */
258#define sctp_init_ack		sctp_init
259#define sctp_init_ack_chunk	sctp_init_chunk
260#define sctp_init_ack_msg	sctp_init_msg
261
262
263/* Selective Ack (SACK) */
264struct sctp_gap_ack_block {
265	uint16_t start;		/* Gap Ack block start */
266	uint16_t end;		/* Gap Ack block end */
267}                  SCTP_PACKED;
268
269struct sctp_sack {
270	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
271	uint32_t a_rwnd;	/* updated a_rwnd of sender */
272	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
273	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
274	/* struct sctp_gap_ack_block's follow */
275	/* uint32_t duplicate_tsn's follow */
276}         SCTP_PACKED;
277
278struct sctp_sack_chunk {
279	struct sctp_chunkhdr ch;
280	struct sctp_sack sack;
281}               SCTP_PACKED;
282
283struct sctp_nr_sack {
284	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
285	uint32_t a_rwnd;	/* updated a_rwnd of sender */
286	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
287	uint16_t num_nr_gap_ack_blks;	/* number of NR Gap Ack blocks */
288	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
289	uint16_t reserved;	/* not currently used */
290	/* struct sctp_gap_ack_block's follow */
291	/* uint32_t duplicate_tsn's follow */
292}            SCTP_PACKED;
293
294struct sctp_nr_sack_chunk {
295	struct sctp_chunkhdr ch;
296	struct sctp_nr_sack nr_sack;
297}                  SCTP_PACKED;
298
299
300/* Heartbeat Request (HEARTBEAT) */
301struct sctp_heartbeat {
302	struct sctp_heartbeat_info_param hb_info;
303}              SCTP_PACKED;
304
305struct sctp_heartbeat_chunk {
306	struct sctp_chunkhdr ch;
307	struct sctp_heartbeat heartbeat;
308}                    SCTP_PACKED;
309
310/* ... used for Heartbeat Ack (HEARTBEAT ACK) */
311#define sctp_heartbeat_ack		sctp_heartbeat
312#define sctp_heartbeat_ack_chunk	sctp_heartbeat_chunk
313
314
315/* Abort Asssociation (ABORT) */
316struct sctp_abort_chunk {
317	struct sctp_chunkhdr ch;
318	/* optional error cause may follow */
319}                SCTP_PACKED;
320
321struct sctp_abort_msg {
322	struct sctphdr sh;
323	struct sctp_abort_chunk msg;
324}              SCTP_PACKED;
325
326
327/* Shutdown Association (SHUTDOWN) */
328struct sctp_shutdown_chunk {
329	struct sctp_chunkhdr ch;
330	uint32_t cumulative_tsn_ack;
331}                   SCTP_PACKED;
332
333
334/* Shutdown Acknowledgment (SHUTDOWN ACK) */
335struct sctp_shutdown_ack_chunk {
336	struct sctp_chunkhdr ch;
337}                       SCTP_PACKED;
338
339
340/* Operation Error (ERROR) */
341struct sctp_error_chunk {
342	struct sctp_chunkhdr ch;
343	/* optional error causes follow */
344}                SCTP_PACKED;
345
346
347/* Cookie Echo (COOKIE ECHO) */
348struct sctp_cookie_echo_chunk {
349	struct sctp_chunkhdr ch;
350	struct sctp_state_cookie cookie;
351}                      SCTP_PACKED;
352
353/* Cookie Acknowledgment (COOKIE ACK) */
354struct sctp_cookie_ack_chunk {
355	struct sctp_chunkhdr ch;
356}                     SCTP_PACKED;
357
358/* Explicit Congestion Notification Echo (ECNE) */
359struct old_sctp_ecne_chunk {
360	struct sctp_chunkhdr ch;
361	uint32_t tsn;
362}                   SCTP_PACKED;
363
364struct sctp_ecne_chunk {
365	struct sctp_chunkhdr ch;
366	uint32_t tsn;
367	uint32_t num_pkts_since_cwr;
368}               SCTP_PACKED;
369
370/* Congestion Window Reduced (CWR) */
371struct sctp_cwr_chunk {
372	struct sctp_chunkhdr ch;
373	uint32_t tsn;
374}              SCTP_PACKED;
375
376/* Shutdown Complete (SHUTDOWN COMPLETE) */
377struct sctp_shutdown_complete_chunk {
378	struct sctp_chunkhdr ch;
379}                            SCTP_PACKED;
380
381/* Oper error holding a stale cookie */
382struct sctp_stale_cookie_msg {
383	struct sctp_paramhdr ph;/* really an error cause */
384	uint32_t time_usec;
385}                     SCTP_PACKED;
386
387struct sctp_adaptation_layer_indication {
388	struct sctp_paramhdr ph;
389	uint32_t indication;
390}                                SCTP_PACKED;
391
392struct sctp_cookie_while_shutting_down {
393	struct sctphdr sh;
394	struct sctp_chunkhdr ch;
395	struct sctp_paramhdr ph;/* really an error cause */
396}                               SCTP_PACKED;
397
398struct sctp_shutdown_complete_msg {
399	struct sctphdr sh;
400	struct sctp_shutdown_complete_chunk shut_cmp;
401}                          SCTP_PACKED;
402
403/*
404 * draft-ietf-tsvwg-addip-sctp
405 */
406/* Address/Stream Configuration Change (ASCONF) */
407struct sctp_asconf_chunk {
408	struct sctp_chunkhdr ch;
409	uint32_t serial_number;
410	/* lookup address parameter (mandatory) */
411	/* asconf parameters follow */
412}                 SCTP_PACKED;
413
414/* Address/Stream Configuration Acknowledge (ASCONF ACK) */
415struct sctp_asconf_ack_chunk {
416	struct sctp_chunkhdr ch;
417	uint32_t serial_number;
418	/* asconf parameters follow */
419}                     SCTP_PACKED;
420
421/* draft-ietf-tsvwg-prsctp */
422/* Forward Cumulative TSN (FORWARD TSN) */
423struct sctp_forward_tsn_chunk {
424	struct sctp_chunkhdr ch;
425	uint32_t new_cumulative_tsn;
426	/* stream/sequence pairs (sctp_strseq) follow */
427}                      SCTP_PACKED;
428
429struct sctp_strseq {
430	uint16_t stream;
431	uint16_t sequence;
432}           SCTP_PACKED;
433
434struct sctp_forward_tsn_msg {
435	struct sctphdr sh;
436	struct sctp_forward_tsn_chunk msg;
437}                    SCTP_PACKED;
438
439/* should be a multiple of 4 - 1 aka 3/7/11 etc. */
440
441#define SCTP_NUM_DB_TO_VERIFY 31
442
443struct sctp_chunk_desc {
444	uint8_t chunk_type;
445	uint8_t data_bytes[SCTP_NUM_DB_TO_VERIFY];
446	uint32_t tsn_ifany;
447}               SCTP_PACKED;
448
449
450struct sctp_pktdrop_chunk {
451	struct sctp_chunkhdr ch;
452	uint32_t bottle_bw;
453	uint32_t current_onq;
454	uint16_t trunc_len;
455	uint16_t reserved;
456	uint8_t data[];
457}                  SCTP_PACKED;
458
459/**********STREAM RESET STUFF ******************/
460
461struct sctp_stream_reset_out_request {
462	struct sctp_paramhdr ph;
463	uint32_t request_seq;	/* monotonically increasing seq no */
464	uint32_t response_seq;	/* if a response, the resp seq no */
465	uint32_t send_reset_at_tsn;	/* last TSN I assigned outbound */
466	uint16_t list_of_streams[];	/* if not all list of streams */
467}                             SCTP_PACKED;
468
469struct sctp_stream_reset_in_request {
470	struct sctp_paramhdr ph;
471	uint32_t request_seq;
472	uint16_t list_of_streams[];	/* if not all list of streams */
473}                            SCTP_PACKED;
474
475
476struct sctp_stream_reset_tsn_request {
477	struct sctp_paramhdr ph;
478	uint32_t request_seq;
479}                             SCTP_PACKED;
480
481struct sctp_stream_reset_response {
482	struct sctp_paramhdr ph;
483	uint32_t response_seq;	/* if a response, the resp seq no */
484	uint32_t result;
485}                          SCTP_PACKED;
486
487struct sctp_stream_reset_response_tsn {
488	struct sctp_paramhdr ph;
489	uint32_t response_seq;	/* if a response, the resp seq no */
490	uint32_t result;
491	uint32_t senders_next_tsn;
492	uint32_t receivers_next_tsn;
493}                              SCTP_PACKED;
494
495struct sctp_stream_reset_add_strm {
496	struct sctp_paramhdr ph;
497	uint32_t request_seq;
498	uint16_t number_of_streams;
499	uint16_t reserved;
500}                          SCTP_PACKED;
501
502#define SCTP_STREAM_RESET_NOTHING   0x00000000	/* Nothing for me to do */
503#define SCTP_STREAM_RESET_PERFORMED 0x00000001	/* Did it */
504#define SCTP_STREAM_RESET_DENIED    0x00000002	/* refused to do it */
505#define SCTP_STREAM_RESET_ERROR_STR 0x00000003	/* bad Stream no */
506#define SCTP_STREAM_RESET_TRY_LATER 0x00000004	/* collision, try again */
507#define SCTP_STREAM_RESET_BAD_SEQNO 0x00000005	/* bad str-reset seq no */
508
509/*
510 * convience structures, note that if you are making a request for specific
511 * streams then the request will need to be an overlay structure.
512 */
513
514struct sctp_stream_reset_out_req {
515	struct sctp_chunkhdr ch;
516	struct sctp_stream_reset_out_request sr_req;
517}                         SCTP_PACKED;
518
519struct sctp_stream_reset_in_req {
520	struct sctp_chunkhdr ch;
521	struct sctp_stream_reset_in_request sr_req;
522}                        SCTP_PACKED;
523
524struct sctp_stream_reset_tsn_req {
525	struct sctp_chunkhdr ch;
526	struct sctp_stream_reset_tsn_request sr_req;
527}                         SCTP_PACKED;
528
529struct sctp_stream_reset_resp {
530	struct sctp_chunkhdr ch;
531	struct sctp_stream_reset_response sr_resp;
532}                      SCTP_PACKED;
533
534/* respone only valid with a TSN request */
535struct sctp_stream_reset_resp_tsn {
536	struct sctp_chunkhdr ch;
537	struct sctp_stream_reset_response_tsn sr_resp;
538}                          SCTP_PACKED;
539
540/****************************************************/
541
542/*
543 * Authenticated chunks support draft-ietf-tsvwg-sctp-auth
544 */
545
546/* Should we make the max be 32? */
547#define SCTP_RANDOM_MAX_SIZE 256
548struct sctp_auth_random {
549	struct sctp_paramhdr ph;/* type = 0x8002 */
550	uint8_t random_data[];
551}                SCTP_PACKED;
552
553struct sctp_auth_chunk_list {
554	struct sctp_paramhdr ph;/* type = 0x8003 */
555	uint8_t chunk_types[];
556}                    SCTP_PACKED;
557
558struct sctp_auth_hmac_algo {
559	struct sctp_paramhdr ph;/* type = 0x8004 */
560	uint16_t hmac_ids[];
561}                   SCTP_PACKED;
562
563struct sctp_auth_chunk {
564	struct sctp_chunkhdr ch;
565	uint16_t shared_key_id;
566	uint16_t hmac_id;
567	uint8_t hmac[];
568}               SCTP_PACKED;
569
570struct sctp_auth_invalid_hmac {
571	struct sctp_paramhdr ph;
572	uint16_t hmac_id;
573	uint16_t padding;
574}                      SCTP_PACKED;
575
576/*
577 * we pre-reserve enough room for a ECNE or CWR AND a SACK with no missing
578 * pieces. If ENCE is missing we could have a couple of blocks. This way we
579 * optimize so we MOST likely can bundle a SACK/ECN with the smallest size
580 * data chunk I will split into. We could increase throughput slightly by
581 * taking out these two but the  24-sack/8-CWR i.e. 32 bytes I pre-reserve I
582 * feel is worth it for now.
583 */
584#ifndef SCTP_MAX_OVERHEAD
585#ifdef INET6
586#define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
587			   sizeof(struct sctphdr) + \
588			   sizeof(struct sctp_ecne_chunk) + \
589			   sizeof(struct sctp_sack_chunk) + \
590			   sizeof(struct ip6_hdr))
591
592#define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
593			   sizeof(struct sctphdr) + \
594			   sizeof(struct ip6_hdr))
595
596
597#define SCTP_MIN_OVERHEAD (sizeof(struct ip6_hdr) + \
598			   sizeof(struct sctphdr))
599
600#else
601#define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
602			   sizeof(struct sctphdr) + \
603			   sizeof(struct sctp_ecne_chunk) + \
604			   sizeof(struct sctp_sack_chunk) + \
605			   sizeof(struct ip))
606
607#define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
608			   sizeof(struct sctphdr) + \
609			   sizeof(struct ip))
610
611
612#define SCTP_MIN_OVERHEAD (sizeof(struct ip) + \
613			   sizeof(struct sctphdr))
614
615#endif				/* INET6 */
616#endif				/* !SCTP_MAX_OVERHEAD */
617
618#define SCTP_MED_V4_OVERHEAD (sizeof(struct sctp_data_chunk) + \
619			      sizeof(struct sctphdr) + \
620			      sizeof(struct ip))
621
622#define SCTP_MIN_V4_OVERHEAD (sizeof(struct ip) + \
623			      sizeof(struct sctphdr))
624
625#undef SCTP_PACKED
626#endif				/* !__sctp_header_h__ */
627