1 /*        $KAME: sctp_structs.h,v 1.13 2005/03/06 16:04:18 itojun Exp $         */
2 /*        $NetBSD: sctp_structs.h,v 1.4 2023/08/10 06:44:12 andvar 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 destination 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