sctp_header.h revision 218129
1169689Skan/*-
2169689Skan * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
3169689Skan *
4169689Skan * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * a) Redistributions of source code must retain the above copyright notice,
8 *   this list of conditions and the following disclaimer.
9 *
10 * b) Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *   the documentation and/or other materials provided with the distribution.
13 *
14 * c) Neither the name of Cisco Systems, Inc. nor the names of its
15 *    contributors may be used to endorse or promote products derived
16 *    from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
20 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28 * THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31/* $KAME: sctp_header.h,v 1.14 2005/03/06 16:04:17 itojun Exp $	 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: head/sys/netinet/sctp_header.h 218129 2011-01-31 11:50:11Z rrs $");
35
36#ifndef __sctp_header_h__
37#define __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 */
48struct 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
56struct 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 */
62struct 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 */
69struct 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 */
80struct sctp_supported_addr_param {
81	struct sctp_paramhdr ph;/* type=SCTP_SUPPORTED_ADDRTYPE */
82	uint16_t addr_type[SCTP_ARRAY_MIN_LEN];	/* array of supported address
83						 * types */
84}                         SCTP_PACKED;
85
86/* ECN parameter */
87struct sctp_ecn_supported_param {
88	struct sctp_paramhdr ph;/* type=SCTP_ECN_CAPABLE */
89}                        SCTP_PACKED;
90
91
92/* heartbeat info parameter */
93struct sctp_heartbeat_info_param {
94	struct sctp_paramhdr ph;
95	uint32_t time_value_1;
96	uint32_t time_value_2;
97	uint32_t random_value1;
98	uint32_t random_value2;
99	uint16_t user_req;
100	uint8_t addr_family;
101	uint8_t addr_len;
102	char address[SCTP_ADDRMAX];
103}                         SCTP_PACKED;
104
105
106/* draft-ietf-tsvwg-prsctp */
107/* PR-SCTP supported parameter */
108struct sctp_prsctp_supported_param {
109	struct sctp_paramhdr ph;
110}                           SCTP_PACKED;
111
112
113/* draft-ietf-tsvwg-addip-sctp */
114struct 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
119struct 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
125struct 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
132struct 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
139struct 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 */
148struct 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
156struct 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) */
166struct 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 */
179struct 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 */
213struct sctp_missing_nat_state {
214	uint16_t cause;
215	uint16_t length;
216	uint8_t data[];
217}                      SCTP_PACKED;
218
219
220struct 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
232struct 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 */
240struct sctp_state_cookie_param {
241	struct sctp_paramhdr ph;
242	struct sctp_state_cookie cookie;
243}                       SCTP_PACKED;
244
245struct sctp_init_chunk {
246	struct sctp_chunkhdr ch;
247	struct sctp_init init;
248}               SCTP_PACKED;
249
250struct 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) */
262struct sctp_gap_ack_block {
263	uint16_t start;		/* Gap Ack block start */
264	uint16_t end;		/* Gap Ack block end */
265}                  SCTP_PACKED;
266
267struct 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
276struct sctp_sack_chunk {
277	struct sctp_chunkhdr ch;
278	struct sctp_sack sack;
279}               SCTP_PACKED;
280
281struct 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
292struct 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) */
299struct sctp_heartbeat {
300	struct sctp_heartbeat_info_param hb_info;
301}              SCTP_PACKED;
302
303struct 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) */
314struct sctp_abort_chunk {
315	struct sctp_chunkhdr ch;
316	/* optional error cause may follow */
317}                SCTP_PACKED;
318
319struct sctp_abort_msg {
320	struct sctphdr sh;
321	struct sctp_abort_chunk msg;
322}              SCTP_PACKED;
323
324
325/* Shutdown Association (SHUTDOWN) */
326struct sctp_shutdown_chunk {
327	struct sctp_chunkhdr ch;
328	uint32_t cumulative_tsn_ack;
329}                   SCTP_PACKED;
330
331
332/* Shutdown Acknowledgment (SHUTDOWN ACK) */
333struct sctp_shutdown_ack_chunk {
334	struct sctp_chunkhdr ch;
335}                       SCTP_PACKED;
336
337
338/* Operation Error (ERROR) */
339struct sctp_error_chunk {
340	struct sctp_chunkhdr ch;
341	/* optional error causes follow */
342}                SCTP_PACKED;
343
344
345/* Cookie Echo (COOKIE ECHO) */
346struct sctp_cookie_echo_chunk {
347	struct sctp_chunkhdr ch;
348	struct sctp_state_cookie cookie;
349}                      SCTP_PACKED;
350
351/* Cookie Acknowledgment (COOKIE ACK) */
352struct sctp_cookie_ack_chunk {
353	struct sctp_chunkhdr ch;
354}                     SCTP_PACKED;
355
356/* Explicit Congestion Notification Echo (ECNE) */
357struct old_sctp_ecne_chunk {
358	struct sctp_chunkhdr ch;
359	uint32_t tsn;
360}                   SCTP_PACKED;
361
362struct 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) */
369struct sctp_cwr_chunk {
370	struct sctp_chunkhdr ch;
371	uint32_t tsn;
372}              SCTP_PACKED;
373
374/* Shutdown Complete (SHUTDOWN COMPLETE) */
375struct sctp_shutdown_complete_chunk {
376	struct sctp_chunkhdr ch;
377}                            SCTP_PACKED;
378
379/* Oper error holding a stale cookie */
380struct sctp_stale_cookie_msg {
381	struct sctp_paramhdr ph;/* really an error cause */
382	uint32_t time_usec;
383}                     SCTP_PACKED;
384
385struct sctp_adaptation_layer_indication {
386	struct sctp_paramhdr ph;
387	uint32_t indication;
388}                                SCTP_PACKED;
389
390struct 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
396struct 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) */
405struct 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) */
413struct 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) */
421struct 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
427struct sctp_strseq {
428	uint16_t stream;
429	uint16_t sequence;
430}           SCTP_PACKED;
431
432struct 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
441struct 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
448struct 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
459struct 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
467struct 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
474struct sctp_stream_reset_tsn_request {
475	struct sctp_paramhdr ph;
476	uint32_t request_seq;
477}                             SCTP_PACKED;
478
479struct 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
485struct 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
493struct 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_NOTHING   0x00000000	/* Nothing for me to do */
501#define SCTP_STREAM_RESET_PERFORMED 0x00000001	/* Did it */
502#define SCTP_STREAM_RESET_DENIED    0x00000002	/* refused to do it */
503#define SCTP_STREAM_RESET_ERROR_STR 0x00000003	/* bad Stream no */
504#define SCTP_STREAM_RESET_TRY_LATER 0x00000004	/* collision, try again */
505#define SCTP_STREAM_RESET_BAD_SEQNO 0x00000005	/* bad str-reset seq no */
506
507/*
508 * convience structures, note that if you are making a request for specific
509 * streams then the request will need to be an overlay structure.
510 */
511
512struct sctp_stream_reset_out_req {
513	struct sctp_chunkhdr ch;
514	struct sctp_stream_reset_out_request sr_req;
515}                         SCTP_PACKED;
516
517struct sctp_stream_reset_in_req {
518	struct sctp_chunkhdr ch;
519	struct sctp_stream_reset_in_request sr_req;
520}                        SCTP_PACKED;
521
522struct sctp_stream_reset_tsn_req {
523	struct sctp_chunkhdr ch;
524	struct sctp_stream_reset_tsn_request sr_req;
525}                         SCTP_PACKED;
526
527struct sctp_stream_reset_resp {
528	struct sctp_chunkhdr ch;
529	struct sctp_stream_reset_response sr_resp;
530}                      SCTP_PACKED;
531
532/* respone only valid with a TSN request */
533struct sctp_stream_reset_resp_tsn {
534	struct sctp_chunkhdr ch;
535	struct sctp_stream_reset_response_tsn sr_resp;
536}                          SCTP_PACKED;
537
538/****************************************************/
539
540/*
541 * Authenticated chunks support draft-ietf-tsvwg-sctp-auth
542 */
543
544/* Should we make the max be 32? */
545#define SCTP_RANDOM_MAX_SIZE 256
546struct sctp_auth_random {
547	struct sctp_paramhdr ph;/* type = 0x8002 */
548	uint8_t random_data[];
549}                SCTP_PACKED;
550
551struct sctp_auth_chunk_list {
552	struct sctp_paramhdr ph;/* type = 0x8003 */
553	uint8_t chunk_types[];
554}                    SCTP_PACKED;
555
556struct sctp_auth_hmac_algo {
557	struct sctp_paramhdr ph;/* type = 0x8004 */
558	uint16_t hmac_ids[];
559}                   SCTP_PACKED;
560
561struct sctp_auth_chunk {
562	struct sctp_chunkhdr ch;
563	uint16_t shared_key_id;
564	uint16_t hmac_id;
565	uint8_t hmac[];
566}               SCTP_PACKED;
567
568struct sctp_auth_invalid_hmac {
569	struct sctp_paramhdr ph;
570	uint16_t hmac_id;
571	uint16_t padding;
572}                      SCTP_PACKED;
573
574/*
575 * we pre-reserve enough room for a ECNE or CWR AND a SACK with no missing
576 * pieces. If ENCE is missing we could have a couple of blocks. This way we
577 * optimize so we MOST likely can bundle a SACK/ECN with the smallest size
578 * data chunk I will split into. We could increase throughput slightly by
579 * taking out these two but the  24-sack/8-CWR i.e. 32 bytes I pre-reserve I
580 * feel is worth it for now.
581 */
582#ifndef SCTP_MAX_OVERHEAD
583#ifdef INET6
584#define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
585			   sizeof(struct sctphdr) + \
586			   sizeof(struct sctp_ecne_chunk) + \
587			   sizeof(struct sctp_sack_chunk) + \
588			   sizeof(struct ip6_hdr))
589
590#define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
591			   sizeof(struct sctphdr) + \
592			   sizeof(struct ip6_hdr))
593
594
595#define SCTP_MIN_OVERHEAD (sizeof(struct ip6_hdr) + \
596			   sizeof(struct sctphdr))
597
598#else
599#define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
600			   sizeof(struct sctphdr) + \
601			   sizeof(struct sctp_ecne_chunk) + \
602			   sizeof(struct sctp_sack_chunk) + \
603			   sizeof(struct ip))
604
605#define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
606			   sizeof(struct sctphdr) + \
607			   sizeof(struct ip))
608
609
610#define SCTP_MIN_OVERHEAD (sizeof(struct ip) + \
611			   sizeof(struct sctphdr))
612
613#endif				/* INET6 */
614#endif				/* !SCTP_MAX_OVERHEAD */
615
616#define SCTP_MED_V4_OVERHEAD (sizeof(struct sctp_data_chunk) + \
617			      sizeof(struct sctphdr) + \
618			      sizeof(struct ip))
619
620#define SCTP_MIN_V4_OVERHEAD (sizeof(struct ip) + \
621			      sizeof(struct sctphdr))
622
623#undef SCTP_PACKED
624#endif				/* !__sctp_header_h__ */
625