xref: /netbsd/sys/netinet/sctp_structs.h (revision 393145cf)
1 /*	$KAME: sctp_structs.h,v 1.13 2005/03/06 16:04:18 itojun Exp $	*/
2 /*	$NetBSD: sctp_structs.h,v 1.3 2023/06/24 05:35:00 msaitoh Exp $ */
3 
4 #ifndef __SCTP_STRUCTS_H__
5 #define __SCTP_STRUCTS_H__
6 
7 /*
8  * Copyright (c) 2001, 2002, 2003, 2004 Cisco Systems, Inc.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *      This product includes software developed by Cisco Systems, Inc.
22  * 4. Neither the name of the project nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY CISCO SYSTEMS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL CISCO SYSTEMS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 #include <sys/queue.h>
39 
40 #include <sys/callout.h>
41 
42 #ifdef IPSEC
43 #include <netipsec/ipsec.h>
44 #include <netipsec/key.h>
45 #endif
46 
47 #include <netinet/sctp_header.h>
48 #include <netinet/sctp_uio.h>
49 
50 struct sctp_timer {
51 	struct callout timer;
52 	int type;
53 	/*
54 	 * Depending on the timer type these will be setup and cast with
55 	 * the appropriate entity.
56 	 */
57 	void *ep;
58 	void *tcb;
59 	void *net;
60 };
61 
62 /*
63  * This is the information we track on each interface that we know about	* from the distant end.
64  */
65 TAILQ_HEAD(sctpnetlisthead, sctp_nets);
66 
67 /*
68  * Users of the iterator need to malloc a iterator with a call to
69  * sctp_initiate_iterator(func, pcb_flags, asoc_state, void-ptr-arg, u_int32_t,
70  *                        u_int32-arg, end_func, inp);
71  *
72  * Use the following two defines if you don't care what pcb flags are on the
73  * EP and/or you don't care what state the association is in.
74  *
75  * Note that if you specify an INP as the last argument then ONLY each
76  * association of that single INP will be executed upon. Note that the
77  * pcb flags STILL apply so if the inp you specify has different pcb_flags
78  * then what you put in pcb_flags nothing will happen. use SCTP_PCB_ANY_FLAGS
79  * to assure the inp you specify gets treated.
80  */
81 #define SCTP_PCB_ANY_FLAGS  0x00000000
82 #define SCTP_ASOC_ANY_STATE 0x00000000
83 
84 typedef void (*asoc_func)(struct sctp_inpcb *, struct sctp_tcb *, void *ptr,
85 			  u_int32_t val);
86 typedef void (*end_func)(void *ptr, u_int32_t val);
87 
88 #define SCTP_ITERATOR_DO_ALL_INP	0x00000001
89 #define SCTP_ITERATOR_DO_SINGLE_INP	0x00000002
90 
91 struct sctp_iterator {
92         LIST_ENTRY(sctp_iterator) sctp_nxt_itr;
93 	struct sctp_timer tmr;
94 	struct sctp_inpcb *inp;	/* ep */
95 	struct sctp_tcb *stcb;	/* assoc */
96 	asoc_func function_toapply;
97 	end_func function_atend;
98 	void *pointer;		/* pointer for apply func to use */
99 	u_int32_t val;		/* value for apply func to use */
100 	u_int32_t pcb_flags;
101 	u_int32_t asoc_state;
102 	u_int32_t iterator_flags;
103 };
104 
105 LIST_HEAD(sctpiterators, sctp_iterator);
106 
107 struct sctp_copy_all {
108 	struct sctp_inpcb *inp;	/* ep */
109 	struct mbuf *m;
110 	struct sctp_sndrcvinfo sndrcv;
111 	int sndlen;
112 	int cnt_sent;
113 	int cnt_failed;
114 };
115 
116 union sctp_sockstore {
117 #ifdef AF_INET
118 	struct sockaddr_in  sin;
119 #endif
120 #ifdef AF_INET6
121 	struct sockaddr_in6 sin6;
122 #endif
123 	struct sockaddr     sa;
124 };
125 
126 struct sctp_nets {
127 	TAILQ_ENTRY(sctp_nets) sctp_next;	/* next link */
128 
129         /* Things on the top half may be able to be split
130 	 * into a common structure shared by all.
131 	 */
132 	struct sctp_timer pmtu_timer;
133 
134 	/*
135 	 * The following two in combination equate to a route entry for
136 	 * v6 or v4.
137 	 */
138 #if 0
139 	struct sctp_route {
140 		struct rtentry *ro_rt;
141 		union sctp_sockstore _l_addr;	/* remote peer addr */
142 		union sctp_sockstore _s_addr;	/* our selected src addr */
143 	} ro;
144 #endif
145 	struct route ro;
146 	/* union sctp_sockstore _l_addr; */
147 	union sctp_sockstore _s_addr;
148 	/* mtu discovered so far */
149 	u_int32_t mtu;
150         u_int32_t ssthresh;		/* not sure about this one for split */
151 
152 	/* smoothed average things for RTT and RTO itself */
153 	int lastsa;
154 	int lastsv;
155 	unsigned int RTO;
156 
157 	/* This is used for SHUTDOWN/SHUTDOWN-ACK/SEND or INIT timers */
158 	struct sctp_timer rxt_timer;
159 
160 	/* last time in seconds I sent to it */
161 	struct timeval last_sent_time;
162 	int ref_count;
163 
164 	/* Congestion stats per destination */
165 	/*
166 	 * flight size variables and such, sorry Vern, I could not avoid
167 	 * this if I wanted performance :>
168 	 */
169 	u_int32_t flight_size;
170 	u_int32_t cwnd; /* actual cwnd */
171 	u_int32_t prev_cwnd; /* cwnd before any processing */
172 	u_int32_t partial_bytes_acked; /* in CA tracks when to incr a MTU */
173 
174 	/* tracking variables to avoid the aloc/free in sack processing */
175 	unsigned int net_ack;
176 	unsigned int net_ack2;
177 	/*
178 	 * These only are valid if the primary dest_sstate holds the
179 	 * SCTP_ADDR_SWITCH_PRIMARY flag
180 	 */
181 	u_int32_t next_tsn_at_change;
182 	u_int32_t heartbeat_random1;
183 	u_int32_t heartbeat_random2;
184 
185 	/* if this guy is ok or not ... status */
186 	u_int16_t dest_state;
187 	/* number of transmit failures to down this guy */
188 	u_int16_t failure_threshold;
189 	/* error stats on destination */
190 	u_int16_t error_count;
191 
192 	/* Flags that probably can be combined into dest_state */
193 	u_int8_t rto_pending;		/* is segment marked for RTO update  ** if we split?*/
194 	u_int8_t fast_retran_ip;	/* fast retransmit in progress */
195 	u_int8_t hb_responded;
196 	u_int8_t cacc_saw_newack;	/* CACC algorithm flag */
197         u_int8_t src_addr_selected;	/* if we split we move */
198 	u_int8_t indx_of_eligible_next_to_use;
199 	u_int8_t addr_is_local;		/* its a local address (if known) could move in split */
200 #ifdef SCTP_HIGH_SPEED
201 	u_int8_t last_hs_used;		/* index into the last HS table entry we used */
202 #endif
203 };
204 
205 
206 struct sctp_data_chunkrec {
207 	u_int32_t TSN_seq;  /* the TSN of this transmit */
208 	u_int16_t stream_seq; /* the stream sequence number of this transmit */
209 	u_int16_t stream_number; /* the stream number of this guy */
210 	u_int32_t payloadtype;
211 	u_int32_t context;	/* from send */
212 
213        /* ECN Nonce: Nonce Value for this chunk */
214         u_int8_t ect_nonce;
215 
216 	/* part of the Highest sacked algorithm to be able to
217 	 * stroke counts on ones that are FR'd.
218 	 */
219 	u_int32_t fast_retran_tsn;	/* sending_seq at the time of FR */
220 	struct timeval timetodrop;	/* time we drop it from queue */
221 	u_int8_t doing_fast_retransmit;
222 	u_int8_t rcv_flags; /* flags pulled from data chunk on inbound
223 			   * for outbound holds sending flags.
224 			   */
225 	u_int8_t state_flags;
226 };
227 
228 TAILQ_HEAD(sctpchunk_listhead, sctp_tmit_chunk);
229 
230 #define CHUNK_FLAGS_FRAGMENT_OK	0x0001
231 
232 struct sctp_tmit_chunk {
233 	union {
234 		struct sctp_data_chunkrec data;
235 		int chunk_id;
236 	} rec;
237 	int32_t   sent;		/* the send status */
238 	int32_t   snd_count;			/* number of times I sent */
239 	u_int32_t flags;		/* flags, such as FRAGMENT_OK */
240 	u_int32_t   send_size;
241 	u_int32_t   book_size;
242 	u_int32_t   mbcnt;
243 	struct sctp_association *asoc;	/* bp to asoc this belongs to */
244 	struct timeval sent_rcv_time;	/* filled in if RTT being calculated */
245 	struct mbuf *data;		/* pointer to mbuf chain of data */
246 	struct sctp_nets *whoTo;
247 	TAILQ_ENTRY(sctp_tmit_chunk) sctp_next;	/* next link */
248 	uint8_t do_rtt;
249 };
250 
251 
252 /*
253  * this struct contains info that is used to track inbound stream data
254  * and help with ordering.
255  */
256 TAILQ_HEAD(sctpwheelunrel_listhead, sctp_stream_in);
257 struct sctp_stream_in {
258 	struct sctpchunk_listhead inqueue;
259 	TAILQ_ENTRY(sctp_stream_in) next_spoke;
260 	uint16_t stream_no;
261 	uint16_t last_sequence_delivered;	/* used for re-order */
262 };
263 
264 /* This struct is used to track the traffic on outbound streams */
265 TAILQ_HEAD(sctpwheel_listhead, sctp_stream_out);
266 struct sctp_stream_out {
267 	struct sctpchunk_listhead outqueue;
268 	TAILQ_ENTRY(sctp_stream_out) next_spoke; /* next link in wheel */
269 	uint16_t stream_no;
270 	uint16_t next_sequence_sent; /* next one I expect to send out */
271 };
272 
273 /* used to keep track of the addresses yet to try to add/delete */
274 TAILQ_HEAD(sctp_asconf_addrhead, sctp_asconf_addr);
275 struct sctp_asconf_addr {
276 	TAILQ_ENTRY(sctp_asconf_addr) next;
277 	struct sctp_asconf_addr_param ap;
278 	struct ifaddr *ifa;	/* save the ifa for add/del ip */
279 	uint8_t	sent;		/* has this been sent yet? */
280 };
281 
282 
283 /*
284  * Here we have information about each individual association that we
285  * track. We probably in production would be more dynamic. But for ease
286  * of implementation we will have a fixed array that we hunt for in a
287  * linear fashion.
288  */
289 struct sctp_association {
290 	/* association state */
291 	int state;
292 	/* queue of pending addrs to add/delete */
293 	struct sctp_asconf_addrhead asconf_queue;
294 	struct timeval time_entered;		/* time we entered state */
295 	struct timeval time_last_rcvd;
296 	struct timeval time_last_sent;
297 	struct timeval time_last_sat_advance;
298 	struct sctp_sndrcvinfo def_send;	/* default send parameters */
299 
300 	/* timers and such */
301 	struct sctp_timer hb_timer;		/* hb timer */
302 	struct sctp_timer dack_timer;		/* Delayed ack timer */
303 	struct sctp_timer asconf_timer;		/* Asconf */
304 	struct sctp_timer strreset_timer;	/* stream reset */
305 	struct sctp_timer shut_guard_timer;	/* guard */
306 	struct sctp_timer autoclose_timer;	/* automatic close timer */
307 	struct sctp_timer delayed_event_timer;	/* timer for delayed events */
308 
309 	/* list of local addresses when add/del in progress */
310 	struct sctpladdr sctp_local_addr_list;
311 	struct sctpnetlisthead nets;
312 
313 	/* Control chunk queue */
314 	struct sctpchunk_listhead control_send_queue;
315 
316 	/* Once a TSN hits the wire it is moved to the sent_queue. We
317 	 * maintain two counts here (don't know if any but retran_cnt
318 	 * is needed). The idea is that the sent_queue_retran_cnt
319 	 * reflects how many chunks have been marked for retranmission
320 	 * by either T3-rxt or FR.
321 	 */
322 	struct sctpchunk_listhead sent_queue;
323 	struct sctpchunk_listhead send_queue;
324 
325 
326 	/* re-assembly queue for fragmented chunks on the inbound path */
327 	struct sctpchunk_listhead reasmqueue;
328 
329 	/*
330 	 * this queue is used when we reach a condition that we can NOT
331 	 * put data into the socket buffer. We track the size of this
332 	 * queue and set our rwnd to the space in the socket minus also
333 	 * the size_on_delivery_queue.
334 	 */
335 	struct sctpchunk_listhead delivery_queue;
336 
337 	struct sctpwheel_listhead out_wheel;
338 
339 	/* If an iterator is looking at me, this is it */
340 	struct sctp_iterator *stcb_starting_point_for_iterator;
341 
342 	/* ASCONF destination address last sent to */
343 	struct sctp_nets *asconf_last_sent_to;
344 
345 	/* ASCONF save the last ASCONF-ACK so we can resend it if necessary */
346 	struct mbuf *last_asconf_ack_sent;
347 
348 	/*
349 	 * if Source Address Selection happening, this will rotate through
350 	 * the link list.
351 	 */
352 	struct sctp_laddr *last_used_address;
353 
354 	/* stream arrays */
355         struct sctp_stream_in  *strmin;
356 	struct sctp_stream_out *strmout;
357 	u_int8_t *mapping_array;
358 	/* primary destination to use */
359 	struct sctp_nets *primary_destination;
360 
361 	/* last place I got a data chunk from */
362 	struct sctp_nets *last_data_chunk_from;
363 	/* last place I got a control from */
364 	struct sctp_nets *last_control_chunk_from;
365 
366 	/* circular looking for output selection */
367 	struct sctp_stream_out *last_out_stream;
368 
369 	/* wait to the point the cum-ack passes
370 	 * pending_reply->sr_resp.reset_at_tsn.
371 	 */
372 	struct sctp_stream_reset_response *pending_reply;
373 	struct sctpchunk_listhead pending_reply_queue;
374 
375 	u_int32_t cookie_preserve_req;
376 	/* ASCONF next seq I am sending out, inits at init-tsn */
377 	uint32_t asconf_seq_out;
378 	/* ASCONF last received ASCONF from peer, starts at peer's TSN-1 */
379 	uint32_t asconf_seq_in;
380 
381 	/* next seq I am sending in str reset messages */
382 	uint32_t str_reset_seq_out;
383 
384 	/* next seq I am expecting in str reset messages */
385 	uint32_t str_reset_seq_in;
386 	u_int32_t str_reset_sending_seq;
387 
388 	/* various verification tag information */
389 	u_int32_t my_vtag;	/*
390 				 * The tag to be used. if assoc is
391 				 * re-initited by remote end, and
392 				 * I have unlocked this will be
393 				 * regenerated to a new random value.
394 				 */
395 	u_int32_t peer_vtag;	/* The peers last tag */
396 
397 	u_int32_t my_vtag_nonce;
398 	u_int32_t peer_vtag_nonce;
399 
400 
401 	/* This is the SCTP fragmentation threshold */
402 	u_int32_t smallest_mtu;
403 
404 	/*
405 	 * Special hook for Fast retransmit, allows us to track the highest
406 	 * TSN that is NEW in this SACK if gap ack blocks are present.
407 	 */
408 	u_int32_t this_sack_highest_gap;
409 
410 	/*
411 	 * The highest consecutive TSN that has been acked by peer on my
412 	 * sends
413 	 */
414 	u_int32_t last_acked_seq;
415 
416 	/* The next TSN that I will use in sending. */
417 	u_int32_t sending_seq;
418 
419 	/* Original seq number I used ??questionable to keep?? */
420 	u_int32_t init_seq_number;
421 
422 	/*
423 	 * We use this value to know if FR's are allowed, i.e. did the
424 	 * cum-ack pass this point or equal it so FR's are now allowed.
425 	 */
426 	u_int32_t t3timeout_highest_marked;
427 
428 	/* The Advanced Peer Ack Point, as required by the PR-SCTP */
429 	/* (A1 in Section 4.2) */
430 	u_int32_t advanced_peer_ack_point;
431 
432 	/*
433 	 * The highest consequetive TSN at the bottom of the mapping
434 	 * array (for his sends).
435 	 */
436 	u_int32_t cumulative_tsn;
437 	/*
438 	 * Used to track the mapping array and its offset bits. This
439 	 * MAY be lower then cumulative_tsn.
440 	 */
441 	u_int32_t mapping_array_base_tsn;
442 	/*
443 	 * used to track highest TSN we have received and is listed in
444 	 * the mapping array.
445 	 */
446 	u_int32_t highest_tsn_inside_map;
447 
448 	u_int32_t last_echo_tsn;
449 	u_int32_t last_cwr_tsn;
450 	u_int32_t fast_recovery_tsn;
451 	u_int32_t sat_t3_recovery_tsn;
452 
453 	u_int32_t tsn_last_delivered;
454 
455 	/*
456 	 * window state information and smallest MTU that I use to bound
457 	 * segmentation
458 	 */
459 	u_int32_t peers_rwnd;
460 	u_int32_t my_rwnd;
461 	u_int32_t my_last_reported_rwnd;
462 	u_int32_t my_rwnd_control_len;
463 
464 	u_int32_t total_output_queue_size;
465 	u_int32_t total_output_mbuf_queue_size;
466 
467 	/* 32 bit nonce stuff */
468 	u_int32_t nonce_resync_tsn;
469 	u_int32_t nonce_wait_tsn;
470 
471 	int ctrl_queue_cnt; /* could be removed  REM */
472 	/*
473 	 * All outbound datagrams queue into this list from the
474 	 * individual stream queue. Here they get assigned a TSN
475 	 * and then await sending. The stream seq comes when it
476 	 * is first put in the individual str queue
477 	 */
478 	unsigned int stream_queue_cnt;
479 	unsigned int send_queue_cnt;
480 	unsigned int sent_queue_cnt;
481 	unsigned int sent_queue_cnt_removeable;
482 	/*
483 	 * Number on sent queue that are marked for retran until this
484 	 * value is 0 we only send one packet of retran'ed data.
485 	 */
486 	unsigned int sent_queue_retran_cnt;
487 
488 	unsigned int size_on_reasm_queue;
489 	unsigned int cnt_on_reasm_queue;
490 	/* amount of data (bytes) currently in flight (on all destinations) */
491 	unsigned int total_flight;
492 	/* Total book size in flight */
493 	unsigned int total_flight_count;	/* count of chunks used with book total */
494 	/* count of destinaton nets and list of destination nets */
495 	unsigned int numnets;
496 
497 	/* Total error count on this association */
498 	unsigned int overall_error_count;
499 
500 	unsigned int size_on_delivery_queue;
501 	unsigned int cnt_on_delivery_queue;
502 
503 	unsigned int cnt_msg_on_sb;
504 
505 	/* All stream count of chunks for delivery */
506 	unsigned int size_on_all_streams;
507 	unsigned int cnt_on_all_streams;
508 
509 	/* Heart Beat delay in ticks */
510 	unsigned int heart_beat_delay;
511 
512 	/* autoclose */
513 	unsigned int sctp_autoclose_ticks;
514 
515 	/* how many preopen streams we have */
516 	unsigned int pre_open_streams;
517 
518 	/* How many streams I support coming into me */
519 	unsigned int max_inbound_streams;
520 
521 	/* the cookie life I award for any cookie, in seconds */
522 	unsigned int cookie_life;
523 
524 	unsigned int numduptsns;
525 	int dup_tsns[SCTP_MAX_DUP_TSNS];
526 	unsigned int initial_init_rto_max;	/* initial RTO for INIT's */
527 	unsigned int initial_rto;		/* initial send RTO */
528 	unsigned int minrto;			/* per assoc RTO-MIN */
529 	unsigned int maxrto;			/* per assoc RTO-MAX */
530 	/* Being that we have no bag to collect stale cookies, and
531 	 * that we really would not want to anyway.. we will count
532 	 * them in this counter. We of course feed them to the
533 	 * pigeons right away (I have always thought of pigeons
534 	 * as flying rats).
535 	 */
536 	u_int16_t stale_cookie_count;
537 
538 	/* For the partial delivery API, if up, invoked
539 	 * this is what last TSN I delivered
540 	 */
541 	u_int16_t str_of_pdapi;
542 	u_int16_t ssn_of_pdapi;
543 
544 
545 	/* counts of actual built streams. Allocation may be more however */
546 	/* could re-arrange to optimize space here. */
547 	u_int16_t streamincnt;
548 	u_int16_t streamoutcnt;
549 
550 	/* my maximum number of retrans of INIT and SEND */
551 	/* copied from SCTP but should be individually setable */
552 	u_int16_t max_init_times;
553 	u_int16_t max_send_times;
554 
555 	u_int16_t def_net_failure;
556 
557 	/*
558 	 * lock flag: 0 is ok to send, 1+ (duals as a retran count) is
559 	 * awaiting ACK
560 	 */
561 	u_int16_t asconf_sent;   /* possibly removable REM */
562 	u_int16_t mapping_array_size;
563 
564 	u_int16_t chunks_on_out_queue; /* total chunks floating around */
565 	int16_t num_send_timers_up;
566 	/*
567 	 * This flag indicates that we need to send the first SACK. If
568 	 * in place it says we have NOT yet sent a SACK and need to.
569 	 */
570 	u_int8_t first_ack_sent;
571 
572 	/* max burst after fast retransmit completes */
573 	u_int8_t max_burst;
574 
575 	u_int8_t sat_network;	/* RTT is in range of sat net or greater */
576 	u_int8_t sat_network_lockout;/* lockout code */
577 	u_int8_t burst_limit_applied;	/* Burst limit in effect at last send? */
578 	/* flag goes on when we are doing a partial delivery api */
579 	u_int8_t hb_random_values[4];
580 	u_int8_t fragmented_delivery_inprogress;
581 	u_int8_t fragment_flags;
582 	u_int8_t hb_ect_randombit;
583         u_int8_t hb_random_idx;
584 
585 	/* ECN Nonce stuff */
586 	u_int8_t receiver_nonce_sum; /* nonce I sum and put in my sack */
587 	u_int8_t ecn_nonce_allowed;  /* Tells us if ECN nonce is on */
588 	u_int8_t nonce_sum_check;    /* On off switch used during re-sync */
589 	u_int8_t nonce_wait_for_ecne;/* flag when we expect a ECN */
590 	u_int8_t peer_supports_ecn_nonce;
591 
592 	/*
593 	 * This value, plus all other ack'd but above cum-ack is added
594 	 * together to cross check against the bit that we have yet to
595 	 * define (probably in the SACK).
596 	 * When the cum-ack is updated, this sum is updated as well.
597 	 */
598 	u_int8_t nonce_sum_expect_base;
599 	/* Flag to tell if ECN is allowed */
600 	u_int8_t ecn_allowed;
601 
602 	/* flag to indicate if peer can do asconf */
603 	uint8_t peer_supports_asconf;
604 	uint8_t peer_supports_asconf_setprim; /* possibly removable REM */
605 	/* pr-sctp support flag */
606 	uint8_t peer_supports_prsctp;
607 
608 	/* stream resets are supported by the peer */
609 	uint8_t peer_supports_strreset;
610 
611 	/*
612 	 * packet drop's are supported by the peer, we don't really care
613 	 * about this but we bookkeep it anyway.
614 	 */
615 	uint8_t peer_supports_pktdrop;
616 
617 	/* Do we allow V6/V4? */
618 	u_int8_t ipv4_addr_legal;
619 	u_int8_t ipv6_addr_legal;
620 	/* Address scoping flags */
621 	/* scope value for IPv4 */
622 	u_int8_t ipv4_local_scope;
623 	/* scope values for IPv6 */
624 	u_int8_t local_scope;
625 	u_int8_t site_scope;
626 	/* loopback scope */
627 	u_int8_t loopback_scope;
628 	/* flags to handle send alternate net tracking */
629 	u_int8_t used_alt_onsack;
630 	u_int8_t used_alt_asconfack;
631 	u_int8_t fast_retran_loss_recovery;
632 	u_int8_t sat_t3_loss_recovery;
633         u_int8_t dropped_special_cnt;
634 	u_int8_t seen_a_sack_this_pkt;
635 	u_int8_t stream_reset_outstanding;
636 	u_int8_t delayed_connection;
637 	u_int8_t ifp_had_enobuf;
638 	u_int8_t saw_sack_with_frags;
639 	/*
640 	 * The mapping array is used to track out of order sequences above
641 	 * last_acked_seq. 0 indicates packet missing 1 indicates packet
642 	 * rec'd. We slide it up every time we raise last_acked_seq and 0
643 	 * trailing locactions out.  If I get a TSN above the array
644 	 * mappingArraySz, I discard the datagram and let retransmit happen.
645 	 */
646 };
647 
648 #endif
649