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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2003 Intel Corp.
6 *
7 * This file is part of the SCTP kernel reference Implementation
8 *
9 * These functions implement the sctp_outq class. The outqueue handles
10 * bundling and queueing of outgoing SCTP chunks.
11 *
12 * The SCTP reference implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * The SCTP reference implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Perry Melange <pmelange@null.cc.uic.edu>
40 * Xingang Guo <xingang.guo@intel.com>
41 * Hui Huang <hui.huang@nokia.com>
42 * Sridhar Samudrala <sri@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 *
45 * Any bugs reported given to us we will try to fix... any fixes shared will
46 * be incorporated into the next SCTP release.
47 */
48
49#include <linux/types.h>
50#include <linux/list.h> /* For struct list_head */
51#include <linux/socket.h>
52#include <linux/ip.h>
53#include <net/sock.h> /* For skb_set_owner_w */
54
55#include <net/sctp/sctp.h>
56#include <net/sctp/sm.h>
57
58/* Declare internal functions here. */
59static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
60static void sctp_check_transmitted(struct sctp_outq *q,
61 struct list_head *transmitted_queue,
62 struct sctp_transport *transport,
63 struct sctp_sackhdr *sack,
64 __u32 highest_new_tsn);
65
66static void sctp_mark_missing(struct sctp_outq *q,
67 struct list_head *transmitted_queue,
68 struct sctp_transport *transport,
69 __u32 highest_new_tsn,
70 int count_of_newacks);
71
72static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
73
74/* Add data to the front of the queue. */
75static inline void sctp_outq_head_data(struct sctp_outq *q,
76 struct sctp_chunk *ch)
77{
David S. Miller79af02c2005-07-08 21:47:49 -070078 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 q->out_qlen += ch->skb->len;
80 return;
81}
82
83/* Take data from the front of the queue. */
84static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
85{
David S. Miller79af02c2005-07-08 21:47:49 -070086 struct sctp_chunk *ch = NULL;
87
88 if (!list_empty(&q->out_chunk_list)) {
89 struct list_head *entry = q->out_chunk_list.next;
90
91 ch = list_entry(entry, struct sctp_chunk, list);
92 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 q->out_qlen -= ch->skb->len;
David S. Miller79af02c2005-07-08 21:47:49 -070094 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 return ch;
96}
97/* Add data chunk to the end of the queue. */
98static inline void sctp_outq_tail_data(struct sctp_outq *q,
99 struct sctp_chunk *ch)
100{
David S. Miller79af02c2005-07-08 21:47:49 -0700101 list_add_tail(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 q->out_qlen += ch->skb->len;
103 return;
104}
105
106/*
107 * SFR-CACC algorithm:
108 * D) If count_of_newacks is greater than or equal to 2
109 * and t was not sent to the current primary then the
110 * sender MUST NOT increment missing report count for t.
111 */
112static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
113 struct sctp_transport *transport,
114 int count_of_newacks)
115{
116 if (count_of_newacks >=2 && transport != primary)
117 return 1;
118 return 0;
119}
120
121/*
122 * SFR-CACC algorithm:
123 * F) If count_of_newacks is less than 2, let d be the
124 * destination to which t was sent. If cacc_saw_newack
125 * is 0 for destination d, then the sender MUST NOT
126 * increment missing report count for t.
127 */
128static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
129 int count_of_newacks)
130{
131 if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack)
132 return 1;
133 return 0;
134}
135
136/*
137 * SFR-CACC algorithm:
138 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
139 * execute steps C, D, F.
140 *
141 * C has been implemented in sctp_outq_sack
142 */
143static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
144 struct sctp_transport *transport,
145 int count_of_newacks)
146{
147 if (!primary->cacc.cycling_changeover) {
148 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
149 return 1;
150 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
151 return 1;
152 return 0;
153 }
154 return 0;
155}
156
157/*
158 * SFR-CACC algorithm:
159 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
160 * than next_tsn_at_change of the current primary, then
161 * the sender MUST NOT increment missing report count
162 * for t.
163 */
164static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
165{
166 if (primary->cacc.cycling_changeover &&
167 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
168 return 1;
169 return 0;
170}
171
172/*
173 * SFR-CACC algorithm:
174 * 3) If the missing report count for TSN t is to be
175 * incremented according to [RFC2960] and
176 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
177 * then the sender MUST futher execute steps 3.1 and
178 * 3.2 to determine if the missing report count for
179 * TSN t SHOULD NOT be incremented.
180 *
181 * 3.3) If 3.1 and 3.2 do not dictate that the missing
182 * report count for t should not be incremented, then
183 * the sender SOULD increment missing report count for
184 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
185 */
186static inline int sctp_cacc_skip(struct sctp_transport *primary,
187 struct sctp_transport *transport,
188 int count_of_newacks,
189 __u32 tsn)
190{
191 if (primary->cacc.changeover_active &&
192 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks)
193 || sctp_cacc_skip_3_2(primary, tsn)))
194 return 1;
195 return 0;
196}
197
198/* Initialize an existing sctp_outq. This does the boring stuff.
199 * You still need to define handlers if you really want to DO
200 * something with this structure...
201 */
202void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
203{
204 q->asoc = asoc;
David S. Miller79af02c2005-07-08 21:47:49 -0700205 INIT_LIST_HEAD(&q->out_chunk_list);
206 INIT_LIST_HEAD(&q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 INIT_LIST_HEAD(&q->retransmit);
208 INIT_LIST_HEAD(&q->sacked);
209 INIT_LIST_HEAD(&q->abandoned);
210
211 q->outstanding_bytes = 0;
212 q->empty = 1;
213 q->cork = 0;
214
215 q->malloced = 0;
216 q->out_qlen = 0;
217}
218
219/* Free the outqueue structure and any related pending chunks.
220 */
221void sctp_outq_teardown(struct sctp_outq *q)
222{
223 struct sctp_transport *transport;
224 struct list_head *lchunk, *pos, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700225 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 /* Throw away unacknowledged chunks. */
228 list_for_each(pos, &q->asoc->peer.transport_addr_list) {
229 transport = list_entry(pos, struct sctp_transport, transports);
230 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
231 chunk = list_entry(lchunk, struct sctp_chunk,
232 transmitted_list);
233 /* Mark as part of a failed message. */
234 sctp_chunk_fail(chunk, q->error);
235 sctp_chunk_free(chunk);
236 }
237 }
238
239 /* Throw away chunks that have been gap ACKed. */
240 list_for_each_safe(lchunk, temp, &q->sacked) {
241 list_del_init(lchunk);
242 chunk = list_entry(lchunk, struct sctp_chunk,
243 transmitted_list);
244 sctp_chunk_fail(chunk, q->error);
245 sctp_chunk_free(chunk);
246 }
247
248 /* Throw away any chunks in the retransmit queue. */
249 list_for_each_safe(lchunk, temp, &q->retransmit) {
250 list_del_init(lchunk);
251 chunk = list_entry(lchunk, struct sctp_chunk,
252 transmitted_list);
253 sctp_chunk_fail(chunk, q->error);
254 sctp_chunk_free(chunk);
255 }
256
257 /* Throw away any chunks that are in the abandoned queue. */
258 list_for_each_safe(lchunk, temp, &q->abandoned) {
259 list_del_init(lchunk);
260 chunk = list_entry(lchunk, struct sctp_chunk,
261 transmitted_list);
262 sctp_chunk_fail(chunk, q->error);
263 sctp_chunk_free(chunk);
264 }
265
266 /* Throw away any leftover data chunks. */
267 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
268
269 /* Mark as send failure. */
270 sctp_chunk_fail(chunk, q->error);
271 sctp_chunk_free(chunk);
272 }
273
274 q->error = 0;
275
276 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700277 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
278 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700280 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281}
282
283/* Free the outqueue structure and any related pending chunks. */
284void sctp_outq_free(struct sctp_outq *q)
285{
286 /* Throw away leftover chunks. */
287 sctp_outq_teardown(q);
288
289 /* If we were kmalloc()'d, free the memory. */
290 if (q->malloced)
291 kfree(q);
292}
293
294/* Put a new chunk in an sctp_outq. */
295int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
296{
297 int error = 0;
298
299 SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
300 q, chunk, chunk && chunk->chunk_hdr ?
301 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
302 : "Illegal Chunk");
303
304 /* If it is data, queue it up, otherwise, send it
305 * immediately.
306 */
307 if (SCTP_CID_DATA == chunk->chunk_hdr->type) {
308 /* Is it OK to queue data chunks? */
309 /* From 9. Termination of Association
310 *
311 * When either endpoint performs a shutdown, the
312 * association on each peer will stop accepting new
313 * data from its user and only deliver data in queue
314 * at the time of sending or receiving the SHUTDOWN
315 * chunk.
316 */
317 switch (q->asoc->state) {
318 case SCTP_STATE_EMPTY:
319 case SCTP_STATE_CLOSED:
320 case SCTP_STATE_SHUTDOWN_PENDING:
321 case SCTP_STATE_SHUTDOWN_SENT:
322 case SCTP_STATE_SHUTDOWN_RECEIVED:
323 case SCTP_STATE_SHUTDOWN_ACK_SENT:
324 /* Cannot send after transport endpoint shutdown */
325 error = -ESHUTDOWN;
326 break;
327
328 default:
329 SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
330 q, chunk, chunk && chunk->chunk_hdr ?
331 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
332 : "Illegal Chunk");
333
334 sctp_outq_tail_data(q, chunk);
335 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
336 SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
337 else
338 SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
339 q->empty = 0;
340 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700341 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700343 list_add_tail(&chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
345 }
346
347 if (error < 0)
348 return error;
349
350 if (!q->cork)
351 error = sctp_outq_flush(q, 0);
352
353 return error;
354}
355
356/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
357 * and the abandoned list are in ascending order.
358 */
359static void sctp_insert_list(struct list_head *head, struct list_head *new)
360{
361 struct list_head *pos;
362 struct sctp_chunk *nchunk, *lchunk;
363 __u32 ntsn, ltsn;
364 int done = 0;
365
366 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
367 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
368
369 list_for_each(pos, head) {
370 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
371 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
372 if (TSN_lt(ntsn, ltsn)) {
373 list_add(new, pos->prev);
374 done = 1;
375 break;
376 }
377 }
378 if (!done)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900379 list_add_tail(new, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380}
381
382/* Mark all the eligible packets on a transport for retransmission. */
383void sctp_retransmit_mark(struct sctp_outq *q,
384 struct sctp_transport *transport,
385 __u8 fast_retransmit)
386{
387 struct list_head *lchunk, *ltemp;
388 struct sctp_chunk *chunk;
389
390 /* Walk through the specified transmitted queue. */
391 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
392 chunk = list_entry(lchunk, struct sctp_chunk,
393 transmitted_list);
394
395 /* If the chunk is abandoned, move it to abandoned list. */
396 if (sctp_chunk_abandoned(chunk)) {
397 list_del_init(lchunk);
398 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800399
400 /* If this chunk has not been previousely acked,
401 * stop considering it 'outstanding'. Our peer
402 * will most likely never see it since it will
403 * not be retransmitted
404 */
405 if (!chunk->tsn_gap_acked) {
406 chunk->transport->flight_size -=
407 sctp_data_size(chunk);
408 q->outstanding_bytes -= sctp_data_size(chunk);
409 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
410 sizeof(struct sk_buff));
411 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 continue;
413 }
414
415 /* If we are doing retransmission due to a fast retransmit,
416 * only the chunk's that are marked for fast retransmit
417 * should be added to the retransmit queue. If we are doing
418 * retransmission due to a timeout or pmtu discovery, only the
419 * chunks that are not yet acked should be added to the
420 * retransmit queue.
421 */
Vlad Yasevich27852c22006-02-02 16:57:31 -0800422 if ((fast_retransmit && (chunk->fast_retransmit > 0)) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 (!fast_retransmit && !chunk->tsn_gap_acked)) {
Vlad Yasevichd0ce9292007-08-24 19:37:46 +0900424 /* If this chunk was sent less then 1 rto ago, do not
425 * retransmit this chunk, but give the peer time
426 * to acknowlege it.
427 */
428 if ((jiffies - chunk->sent_at) < transport->rto)
429 continue;
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 /* RFC 2960 6.2.1 Processing a Received SACK
432 *
433 * C) Any time a DATA chunk is marked for
434 * retransmission (via either T3-rtx timer expiration
435 * (Section 6.3.3) or via fast retransmit
436 * (Section 7.2.4)), add the data size of those
437 * chunks to the rwnd.
438 */
Sridhar Samudralacd497882006-09-29 17:09:05 -0700439 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
440 sizeof(struct sk_buff));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 q->outstanding_bytes -= sctp_data_size(chunk);
442 transport->flight_size -= sctp_data_size(chunk);
443
444 /* sctpimpguide-05 Section 2.8.2
445 * M5) If a T3-rtx timer expires, the
446 * 'TSN.Missing.Report' of all affected TSNs is set
447 * to 0.
448 */
449 chunk->tsn_missing_report = 0;
450
451 /* If a chunk that is being used for RTT measurement
452 * has to be retransmitted, we cannot use this chunk
453 * anymore for RTT measurements. Reset rto_pending so
454 * that a new RTT measurement is started when a new
455 * data chunk is sent.
456 */
457 if (chunk->rtt_in_progress) {
458 chunk->rtt_in_progress = 0;
459 transport->rto_pending = 0;
460 }
461
462 /* Move the chunk to the retransmit queue. The chunks
463 * on the retransmit queue are always kept in order.
464 */
465 list_del_init(lchunk);
466 sctp_insert_list(&q->retransmit, lchunk);
467 }
468 }
469
470 SCTP_DEBUG_PRINTK("%s: transport: %p, fast_retransmit: %d, "
471 "cwnd: %d, ssthresh: %d, flight_size: %d, "
472 "pba: %d\n", __FUNCTION__,
473 transport, fast_retransmit,
474 transport->cwnd, transport->ssthresh,
475 transport->flight_size,
476 transport->partial_bytes_acked);
477
478}
479
480/* Mark all the eligible packets on a transport for retransmission and force
481 * one packet out.
482 */
483void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
484 sctp_retransmit_reason_t reason)
485{
486 int error = 0;
487 __u8 fast_retransmit = 0;
488
489 switch(reason) {
490 case SCTP_RTXR_T3_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700491 SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
493 /* Update the retran path if the T3-rtx timer has expired for
494 * the current retran path.
495 */
496 if (transport == transport->asoc->peer.retran_path)
497 sctp_assoc_update_retran_path(transport->asoc);
498 break;
499 case SCTP_RTXR_FAST_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700500 SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
502 fast_retransmit = 1;
503 break;
504 case SCTP_RTXR_PMTUD:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700505 SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700507 default:
508 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 }
510
511 sctp_retransmit_mark(q, transport, fast_retransmit);
512
513 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
514 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
515 * following the procedures outlined in C1 - C5.
516 */
517 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
518
519 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
520
521 if (error)
522 q->asoc->base.sk->sk_err = -error;
523}
524
525/*
526 * Transmit DATA chunks on the retransmit queue. Upon return from
527 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
528 * need to be transmitted by the caller.
529 * We assume that pkt->transport has already been set.
530 *
531 * The return value is a normal kernel error return value.
532 */
533static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
534 int rtx_timeout, int *start_timer)
535{
536 struct list_head *lqueue;
537 struct list_head *lchunk, *lchunk1;
538 struct sctp_transport *transport = pkt->transport;
539 sctp_xmit_t status;
540 struct sctp_chunk *chunk, *chunk1;
541 struct sctp_association *asoc;
542 int error = 0;
543
544 asoc = q->asoc;
545 lqueue = &q->retransmit;
546
547 /* RFC 2960 6.3.3 Handle T3-rtx Expiration
548 *
549 * E3) Determine how many of the earliest (i.e., lowest TSN)
550 * outstanding DATA chunks for the address for which the
551 * T3-rtx has expired will fit into a single packet, subject
552 * to the MTU constraint for the path corresponding to the
553 * destination transport address to which the retransmission
554 * is being sent (this may be different from the address for
555 * which the timer expires [see Section 6.4]). Call this value
556 * K. Bundle and retransmit those K DATA chunks in a single
557 * packet to the destination endpoint.
558 *
559 * [Just to be painfully clear, if we are retransmitting
560 * because a timeout just happened, we should send only ONE
561 * packet of retransmitted data.]
562 */
563 lchunk = sctp_list_dequeue(lqueue);
564
565 while (lchunk) {
566 chunk = list_entry(lchunk, struct sctp_chunk,
567 transmitted_list);
568
569 /* Make sure that Gap Acked TSNs are not retransmitted. A
570 * simple approach is just to move such TSNs out of the
571 * way and into a 'transmitted' queue and skip to the
572 * next chunk.
573 */
574 if (chunk->tsn_gap_acked) {
575 list_add_tail(lchunk, &transport->transmitted);
576 lchunk = sctp_list_dequeue(lqueue);
577 continue;
578 }
579
580 /* Attempt to append this chunk to the packet. */
581 status = sctp_packet_append_chunk(pkt, chunk);
582
583 switch (status) {
584 case SCTP_XMIT_PMTU_FULL:
585 /* Send this packet. */
586 if ((error = sctp_packet_transmit(pkt)) == 0)
587 *start_timer = 1;
588
589 /* If we are retransmitting, we should only
590 * send a single packet.
591 */
592 if (rtx_timeout) {
593 list_add(lchunk, lqueue);
594 lchunk = NULL;
595 }
596
597 /* Bundle lchunk in the next round. */
598 break;
599
600 case SCTP_XMIT_RWND_FULL:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900601 /* Send this packet. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 if ((error = sctp_packet_transmit(pkt)) == 0)
603 *start_timer = 1;
604
605 /* Stop sending DATA as there is no more room
606 * at the receiver.
607 */
608 list_add(lchunk, lqueue);
609 lchunk = NULL;
610 break;
611
612 case SCTP_XMIT_NAGLE_DELAY:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900613 /* Send this packet. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 if ((error = sctp_packet_transmit(pkt)) == 0)
615 *start_timer = 1;
616
617 /* Stop sending DATA because of nagle delay. */
618 list_add(lchunk, lqueue);
619 lchunk = NULL;
620 break;
621
622 default:
623 /* The append was successful, so add this chunk to
624 * the transmitted list.
625 */
626 list_add_tail(lchunk, &transport->transmitted);
627
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900628 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 * after it is retransmitted.
630 */
Vlad Yasevich27852c22006-02-02 16:57:31 -0800631 if (chunk->fast_retransmit > 0)
632 chunk->fast_retransmit = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
634 *start_timer = 1;
635 q->empty = 0;
636
637 /* Retrieve a new chunk to bundle. */
638 lchunk = sctp_list_dequeue(lqueue);
639 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700640 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
642 /* If we are here due to a retransmit timeout or a fast
643 * retransmit and if there are any chunks left in the retransmit
644 * queue that could not fit in the PMTU sized packet, they need * to be marked as ineligible for a subsequent fast retransmit.
645 */
646 if (rtx_timeout && !lchunk) {
647 list_for_each(lchunk1, lqueue) {
648 chunk1 = list_entry(lchunk1, struct sctp_chunk,
649 transmitted_list);
Vlad Yasevich27852c22006-02-02 16:57:31 -0800650 if (chunk1->fast_retransmit > 0)
651 chunk1->fast_retransmit = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 }
653 }
654 }
655
656 return error;
657}
658
659/* Cork the outqueue so queued chunks are really queued. */
660int sctp_outq_uncork(struct sctp_outq *q)
661{
662 int error = 0;
663 if (q->cork) {
664 q->cork = 0;
665 error = sctp_outq_flush(q, 0);
666 }
667 return error;
668}
669
670/*
671 * Try to flush an outqueue.
672 *
673 * Description: Send everything in q which we legally can, subject to
674 * congestion limitations.
675 * * Note: This function can be called from multiple contexts so appropriate
676 * locking concerns must be made. Today we use the sock lock to protect
677 * this function.
678 */
679int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
680{
681 struct sctp_packet *packet;
682 struct sctp_packet singleton;
683 struct sctp_association *asoc = q->asoc;
684 __u16 sport = asoc->base.bind_addr.port;
685 __u16 dport = asoc->peer.port;
686 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 struct sctp_transport *transport = NULL;
688 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700689 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 sctp_xmit_t status;
691 int error = 0;
692 int start_timer = 0;
693
694 /* These transports have chunks to send. */
695 struct list_head transport_list;
696 struct list_head *ltransport;
697
698 INIT_LIST_HEAD(&transport_list);
699 packet = NULL;
700
701 /*
702 * 6.10 Bundling
703 * ...
704 * When bundling control chunks with DATA chunks, an
705 * endpoint MUST place control chunks first in the outbound
706 * SCTP packet. The transmitter MUST transmit DATA chunks
707 * within a SCTP packet in increasing order of TSN.
708 * ...
709 */
710
David S. Miller79af02c2005-07-08 21:47:49 -0700711 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
712 list_del_init(&chunk->list);
713
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 /* Pick the right transport to use. */
715 new_transport = chunk->transport;
716
717 if (!new_transport) {
718 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700719 } else if ((new_transport->state == SCTP_INACTIVE) ||
720 (new_transport->state == SCTP_UNCONFIRMED)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700721 /* If the chunk is Heartbeat or Heartbeat Ack,
722 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 * inactive.
724 *
725 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900726 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 * A HEARTBEAT ACK is always sent to the source IP
728 * address of the IP datagram containing the
729 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900730 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 */
732 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
733 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK)
734 new_transport = asoc->peer.active_path;
735 }
736
737 /* Are we switching transports?
738 * Take care of transport locks.
739 */
740 if (new_transport != transport) {
741 transport = new_transport;
742 if (list_empty(&transport->send_ready)) {
743 list_add_tail(&transport->send_ready,
744 &transport_list);
745 }
746 packet = &transport->packet;
747 sctp_packet_config(packet, vtag,
748 asoc->peer.ecn_capable);
749 }
750
751 switch (chunk->chunk_hdr->type) {
752 /*
753 * 6.10 Bundling
754 * ...
755 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
756 * COMPLETE with any other chunks. [Send them immediately.]
757 */
758 case SCTP_CID_INIT:
759 case SCTP_CID_INIT_ACK:
760 case SCTP_CID_SHUTDOWN_COMPLETE:
761 sctp_packet_init(&singleton, transport, sport, dport);
762 sctp_packet_config(&singleton, vtag, 0);
763 sctp_packet_append_chunk(&singleton, chunk);
764 error = sctp_packet_transmit(&singleton);
765 if (error < 0)
766 return error;
767 break;
768
769 case SCTP_CID_ABORT:
770 case SCTP_CID_SACK:
771 case SCTP_CID_HEARTBEAT:
772 case SCTP_CID_HEARTBEAT_ACK:
773 case SCTP_CID_SHUTDOWN:
774 case SCTP_CID_SHUTDOWN_ACK:
775 case SCTP_CID_ERROR:
776 case SCTP_CID_COOKIE_ECHO:
777 case SCTP_CID_COOKIE_ACK:
778 case SCTP_CID_ECN_ECNE:
779 case SCTP_CID_ECN_CWR:
780 case SCTP_CID_ASCONF:
781 case SCTP_CID_ASCONF_ACK:
782 case SCTP_CID_FWD_TSN:
783 sctp_packet_transmit_chunk(packet, chunk);
784 break;
785
786 default:
787 /* We built a chunk with an illegal type! */
788 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700789 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 }
791
792 /* Is it OK to send data chunks? */
793 switch (asoc->state) {
794 case SCTP_STATE_COOKIE_ECHOED:
795 /* Only allow bundling when this packet has a COOKIE-ECHO
796 * chunk.
797 */
798 if (!packet || !packet->has_cookie_echo)
799 break;
800
801 /* fallthru */
802 case SCTP_STATE_ESTABLISHED:
803 case SCTP_STATE_SHUTDOWN_PENDING:
804 case SCTP_STATE_SHUTDOWN_RECEIVED:
805 /*
806 * RFC 2960 6.1 Transmission of DATA Chunks
807 *
808 * C) When the time comes for the sender to transmit,
809 * before sending new DATA chunks, the sender MUST
810 * first transmit any outstanding DATA chunks which
811 * are marked for retransmission (limited by the
812 * current cwnd).
813 */
814 if (!list_empty(&q->retransmit)) {
815 if (transport == asoc->peer.retran_path)
816 goto retran;
817
818 /* Switch transports & prepare the packet. */
819
820 transport = asoc->peer.retran_path;
821
822 if (list_empty(&transport->send_ready)) {
823 list_add_tail(&transport->send_ready,
824 &transport_list);
825 }
826
827 packet = &transport->packet;
828 sctp_packet_config(packet, vtag,
829 asoc->peer.ecn_capable);
830 retran:
831 error = sctp_outq_flush_rtx(q, packet,
832 rtx_timeout, &start_timer);
833
834 if (start_timer)
835 sctp_transport_reset_timers(transport);
836
837 /* This can happen on COOKIE-ECHO resend. Only
838 * one chunk can get bundled with a COOKIE-ECHO.
839 */
840 if (packet->has_cookie_echo)
841 goto sctp_flush_out;
842
843 /* Don't send new data if there is still data
844 * waiting to retransmit.
845 */
846 if (!list_empty(&q->retransmit))
847 goto sctp_flush_out;
848 }
849
850 /* Finally, transmit new packets. */
851 start_timer = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
853 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
854 * stream identifier.
855 */
856 if (chunk->sinfo.sinfo_stream >=
857 asoc->c.sinit_num_ostreams) {
858
859 /* Mark as failed send. */
860 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
861 sctp_chunk_free(chunk);
862 continue;
863 }
864
865 /* Has this chunk expired? */
866 if (sctp_chunk_abandoned(chunk)) {
867 sctp_chunk_fail(chunk, 0);
868 sctp_chunk_free(chunk);
869 continue;
870 }
871
872 /* If there is a specified transport, use it.
873 * Otherwise, we want to use the active path.
874 */
875 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700876 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700877 ((new_transport->state == SCTP_INACTIVE) ||
878 (new_transport->state == SCTP_UNCONFIRMED)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 new_transport = asoc->peer.active_path;
880
881 /* Change packets if necessary. */
882 if (new_transport != transport) {
883 transport = new_transport;
884
885 /* Schedule to have this transport's
886 * packet flushed.
887 */
888 if (list_empty(&transport->send_ready)) {
889 list_add_tail(&transport->send_ready,
890 &transport_list);
891 }
892
893 packet = &transport->packet;
894 sctp_packet_config(packet, vtag,
895 asoc->peer.ecn_capable);
896 }
897
898 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
899 q, chunk,
900 chunk && chunk->chunk_hdr ?
901 sctp_cname(SCTP_ST_CHUNK(
902 chunk->chunk_hdr->type))
903 : "Illegal Chunk");
904
905 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
906 "%p skb->users %d.\n",
907 ntohl(chunk->subh.data_hdr->tsn),
908 chunk->skb ?chunk->skb->head : NULL,
909 chunk->skb ?
910 atomic_read(&chunk->skb->users) : -1);
911
912 /* Add the chunk to the packet. */
913 status = sctp_packet_transmit_chunk(packet, chunk);
914
915 switch (status) {
916 case SCTP_XMIT_PMTU_FULL:
917 case SCTP_XMIT_RWND_FULL:
918 case SCTP_XMIT_NAGLE_DELAY:
919 /* We could not append this chunk, so put
920 * the chunk back on the output queue.
921 */
922 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
923 "not transmit TSN: 0x%x, status: %d\n",
924 ntohl(chunk->subh.data_hdr->tsn),
925 status);
926 sctp_outq_head_data(q, chunk);
927 goto sctp_flush_out;
928 break;
929
930 case SCTP_XMIT_OK:
931 break;
932
933 default:
934 BUG();
935 }
936
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900937 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 * call below will succeed all the time and add the
939 * chunk to the transmitted list and restart the
940 * timers.
941 * It is possible that the call can fail under OOM
942 * conditions.
943 *
944 * Is this really a problem? Won't this behave
945 * like a lost TSN?
946 */
947 list_add_tail(&chunk->transmitted_list,
948 &transport->transmitted);
949
950 sctp_transport_reset_timers(transport);
951
952 q->empty = 0;
953
954 /* Only let one DATA chunk get bundled with a
955 * COOKIE-ECHO chunk.
956 */
957 if (packet->has_cookie_echo)
958 goto sctp_flush_out;
959 }
960 break;
961
962 default:
963 /* Do nothing. */
964 break;
965 }
966
967sctp_flush_out:
968
969 /* Before returning, examine all the transports touched in
970 * this call. Right now, we bluntly force clear all the
971 * transports. Things might change after we implement Nagle.
972 * But such an examination is still required.
973 *
974 * --xguo
975 */
976 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
977 struct sctp_transport *t = list_entry(ltransport,
978 struct sctp_transport,
979 send_ready);
980 packet = &t->packet;
981 if (!sctp_packet_empty(packet))
982 error = sctp_packet_transmit(packet);
983 }
984
985 return error;
986}
987
988/* Update unack_data based on the incoming SACK chunk */
989static void sctp_sack_update_unack_data(struct sctp_association *assoc,
990 struct sctp_sackhdr *sack)
991{
992 sctp_sack_variable_t *frags;
993 __u16 unack_data;
994 int i;
995
996 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
997
998 frags = sack->variable;
999 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1000 unack_data -= ((ntohs(frags[i].gab.end) -
1001 ntohs(frags[i].gab.start) + 1));
1002 }
1003
1004 assoc->unack_data = unack_data;
1005}
1006
1007/* Return the highest new tsn that is acknowledged by the given SACK chunk. */
1008static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack,
1009 struct sctp_association *asoc)
1010{
1011 struct list_head *ltransport, *lchunk;
1012 struct sctp_transport *transport;
1013 struct sctp_chunk *chunk;
1014 __u32 highest_new_tsn, tsn;
1015 struct list_head *transport_list = &asoc->peer.transport_addr_list;
1016
1017 highest_new_tsn = ntohl(sack->cum_tsn_ack);
1018
1019 list_for_each(ltransport, transport_list) {
1020 transport = list_entry(ltransport, struct sctp_transport,
1021 transports);
1022 list_for_each(lchunk, &transport->transmitted) {
1023 chunk = list_entry(lchunk, struct sctp_chunk,
1024 transmitted_list);
1025 tsn = ntohl(chunk->subh.data_hdr->tsn);
1026
1027 if (!chunk->tsn_gap_acked &&
1028 TSN_lt(highest_new_tsn, tsn) &&
1029 sctp_acked(sack, tsn))
1030 highest_new_tsn = tsn;
1031 }
1032 }
1033
1034 return highest_new_tsn;
1035}
1036
1037/* This is where we REALLY process a SACK.
1038 *
1039 * Process the SACK against the outqueue. Mostly, this just frees
1040 * things off the transmitted queue.
1041 */
1042int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
1043{
1044 struct sctp_association *asoc = q->asoc;
1045 struct sctp_transport *transport;
1046 struct sctp_chunk *tchunk = NULL;
1047 struct list_head *lchunk, *transport_list, *pos, *temp;
1048 sctp_sack_variable_t *frags = sack->variable;
1049 __u32 sack_ctsn, ctsn, tsn;
1050 __u32 highest_tsn, highest_new_tsn;
1051 __u32 sack_a_rwnd;
1052 unsigned outstanding;
1053 struct sctp_transport *primary = asoc->peer.primary_path;
1054 int count_of_newacks = 0;
1055
1056 /* Grab the association's destination address list. */
1057 transport_list = &asoc->peer.transport_addr_list;
1058
1059 sack_ctsn = ntohl(sack->cum_tsn_ack);
1060
1061 /*
1062 * SFR-CACC algorithm:
1063 * On receipt of a SACK the sender SHOULD execute the
1064 * following statements.
1065 *
1066 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1067 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1068 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1069 * all destinations.
1070 */
1071 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1072 primary->cacc.changeover_active = 0;
1073 list_for_each(pos, transport_list) {
1074 transport = list_entry(pos, struct sctp_transport,
1075 transports);
1076 transport->cacc.cycling_changeover = 0;
1077 }
1078 }
1079
1080 /*
1081 * SFR-CACC algorithm:
1082 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1083 * is set the receiver of the SACK MUST take the following actions:
1084 *
1085 * A) Initialize the cacc_saw_newack to 0 for all destination
1086 * addresses.
1087 */
Al Viro34bcca22006-11-20 17:27:15 -08001088 if (sack->num_gap_ack_blocks &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089 primary->cacc.changeover_active) {
1090 list_for_each(pos, transport_list) {
1091 transport = list_entry(pos, struct sctp_transport,
1092 transports);
1093 transport->cacc.cacc_saw_newack = 0;
1094 }
1095 }
1096
1097 /* Get the highest TSN in the sack. */
1098 highest_tsn = sack_ctsn;
1099 if (sack->num_gap_ack_blocks)
1100 highest_tsn +=
1101 ntohs(frags[ntohs(sack->num_gap_ack_blocks) - 1].gab.end);
1102
1103 if (TSN_lt(asoc->highest_sacked, highest_tsn)) {
1104 highest_new_tsn = highest_tsn;
1105 asoc->highest_sacked = highest_tsn;
1106 } else {
1107 highest_new_tsn = sctp_highest_new_tsn(sack, asoc);
1108 }
1109
1110 /* Run through the retransmit queue. Credit bytes received
1111 * and free those chunks that we can.
1112 */
1113 sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn);
1114 sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0);
1115
1116 /* Run through the transmitted queue.
1117 * Credit bytes received and free those chunks which we can.
1118 *
1119 * This is a MASSIVE candidate for optimization.
1120 */
1121 list_for_each(pos, transport_list) {
1122 transport = list_entry(pos, struct sctp_transport,
1123 transports);
1124 sctp_check_transmitted(q, &transport->transmitted,
1125 transport, sack, highest_new_tsn);
1126 /*
1127 * SFR-CACC algorithm:
1128 * C) Let count_of_newacks be the number of
1129 * destinations for which cacc_saw_newack is set.
1130 */
1131 if (transport->cacc.cacc_saw_newack)
1132 count_of_newacks ++;
1133 }
1134
1135 list_for_each(pos, transport_list) {
1136 transport = list_entry(pos, struct sctp_transport,
1137 transports);
1138 sctp_mark_missing(q, &transport->transmitted, transport,
1139 highest_new_tsn, count_of_newacks);
1140 }
1141
1142 /* Move the Cumulative TSN Ack Point if appropriate. */
1143 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn))
1144 asoc->ctsn_ack_point = sack_ctsn;
1145
1146 /* Update unack_data field in the assoc. */
1147 sctp_sack_update_unack_data(asoc, sack);
1148
1149 ctsn = asoc->ctsn_ack_point;
1150
1151 /* Throw away stuff rotting on the sack queue. */
1152 list_for_each_safe(lchunk, temp, &q->sacked) {
1153 tchunk = list_entry(lchunk, struct sctp_chunk,
1154 transmitted_list);
1155 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1156 if (TSN_lte(tsn, ctsn))
1157 sctp_chunk_free(tchunk);
1158 }
1159
1160 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1161 * number of bytes still outstanding after processing the
1162 * Cumulative TSN Ack and the Gap Ack Blocks.
1163 */
1164
1165 sack_a_rwnd = ntohl(sack->a_rwnd);
1166 outstanding = q->outstanding_bytes;
1167
1168 if (outstanding < sack_a_rwnd)
1169 sack_a_rwnd -= outstanding;
1170 else
1171 sack_a_rwnd = 0;
1172
1173 asoc->peer.rwnd = sack_a_rwnd;
1174
1175 sctp_generate_fwdtsn(q, sack_ctsn);
1176
1177 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
1178 __FUNCTION__, sack_ctsn);
1179 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1180 "%p is 0x%x. Adv peer ack point: 0x%x\n",
1181 __FUNCTION__, asoc, ctsn, asoc->adv_peer_ack_point);
1182
1183 /* See if all chunks are acked.
1184 * Make sure the empty queue handler will get run later.
1185 */
David S. Miller79af02c2005-07-08 21:47:49 -07001186 q->empty = (list_empty(&q->out_chunk_list) &&
1187 list_empty(&q->control_chunk_list) &&
1188 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 if (!q->empty)
1190 goto finish;
1191
1192 list_for_each(pos, transport_list) {
1193 transport = list_entry(pos, struct sctp_transport,
1194 transports);
1195 q->empty = q->empty && list_empty(&transport->transmitted);
1196 if (!q->empty)
1197 goto finish;
1198 }
1199
1200 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1201finish:
1202 return q->empty;
1203}
1204
1205/* Is the outqueue empty? */
1206int sctp_outq_is_empty(const struct sctp_outq *q)
1207{
1208 return q->empty;
1209}
1210
1211/********************************************************************
1212 * 2nd Level Abstractions
1213 ********************************************************************/
1214
1215/* Go through a transport's transmitted list or the association's retransmit
1216 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1217 * The retransmit list will not have an associated transport.
1218 *
1219 * I added coherent debug information output. --xguo
1220 *
1221 * Instead of printing 'sacked' or 'kept' for each TSN on the
1222 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1223 * KEPT TSN6-TSN7, etc.
1224 */
1225static void sctp_check_transmitted(struct sctp_outq *q,
1226 struct list_head *transmitted_queue,
1227 struct sctp_transport *transport,
1228 struct sctp_sackhdr *sack,
1229 __u32 highest_new_tsn_in_sack)
1230{
1231 struct list_head *lchunk;
1232 struct sctp_chunk *tchunk;
1233 struct list_head tlist;
1234 __u32 tsn;
1235 __u32 sack_ctsn;
1236 __u32 rtt;
1237 __u8 restart_timer = 0;
1238 int bytes_acked = 0;
1239
1240 /* These state variables are for coherent debug output. --xguo */
1241
1242#if SCTP_DEBUG
1243 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1244 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1245 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1246 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1247
1248 /* 0 : The last TSN was ACKed.
1249 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1250 * -1: We need to initialize.
1251 */
1252 int dbg_prt_state = -1;
1253#endif /* SCTP_DEBUG */
1254
1255 sack_ctsn = ntohl(sack->cum_tsn_ack);
1256
1257 INIT_LIST_HEAD(&tlist);
1258
1259 /* The while loop will skip empty transmitted queues. */
1260 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1261 tchunk = list_entry(lchunk, struct sctp_chunk,
1262 transmitted_list);
1263
1264 if (sctp_chunk_abandoned(tchunk)) {
1265 /* Move the chunk to abandoned list. */
1266 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001267
1268 /* If this chunk has not been acked, stop
1269 * considering it as 'outstanding'.
1270 */
1271 if (!tchunk->tsn_gap_acked) {
1272 tchunk->transport->flight_size -=
1273 sctp_data_size(tchunk);
1274 q->outstanding_bytes -= sctp_data_size(tchunk);
1275 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 continue;
1277 }
1278
1279 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1280 if (sctp_acked(sack, tsn)) {
1281 /* If this queue is the retransmit queue, the
1282 * retransmit timer has already reclaimed
1283 * the outstanding bytes for this chunk, so only
1284 * count bytes associated with a transport.
1285 */
1286 if (transport) {
1287 /* If this chunk is being used for RTT
1288 * measurement, calculate the RTT and update
1289 * the RTO using this value.
1290 *
1291 * 6.3.1 C5) Karn's algorithm: RTT measurements
1292 * MUST NOT be made using packets that were
1293 * retransmitted (and thus for which it is
1294 * ambiguous whether the reply was for the
1295 * first instance of the packet or a later
1296 * instance).
1297 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001298 if (!tchunk->tsn_gap_acked &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 !tchunk->resent &&
1300 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001301 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 rtt = jiffies - tchunk->sent_at;
1303 sctp_transport_update_rto(transport,
1304 rtt);
1305 }
1306 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001307 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308 /* RFC 2960 6.3.2 Retransmission Timer Rules
1309 *
1310 * R3) Whenever a SACK is received
1311 * that acknowledges the DATA chunk
1312 * with the earliest outstanding TSN
1313 * for that address, restart T3-rtx
1314 * timer for that address with its
1315 * current RTO.
1316 */
1317 restart_timer = 1;
1318
1319 if (!tchunk->tsn_gap_acked) {
1320 tchunk->tsn_gap_acked = 1;
1321 bytes_acked += sctp_data_size(tchunk);
1322 /*
1323 * SFR-CACC algorithm:
1324 * 2) If the SACK contains gap acks
1325 * and the flag CHANGEOVER_ACTIVE is
1326 * set the receiver of the SACK MUST
1327 * take the following action:
1328 *
1329 * B) For each TSN t being acked that
1330 * has not been acked in any SACK so
1331 * far, set cacc_saw_newack to 1 for
1332 * the destination that the TSN was
1333 * sent to.
1334 */
1335 if (transport &&
1336 sack->num_gap_ack_blocks &&
1337 q->asoc->peer.primary_path->cacc.
1338 changeover_active)
1339 transport->cacc.cacc_saw_newack
1340 = 1;
1341 }
1342
1343 list_add_tail(&tchunk->transmitted_list,
1344 &q->sacked);
1345 } else {
1346 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1347 * M2) Each time a SACK arrives reporting
1348 * 'Stray DATA chunk(s)' record the highest TSN
1349 * reported as newly acknowledged, call this
1350 * value 'HighestTSNinSack'. A newly
1351 * acknowledged DATA chunk is one not
1352 * previously acknowledged in a SACK.
1353 *
1354 * When the SCTP sender of data receives a SACK
1355 * chunk that acknowledges, for the first time,
1356 * the receipt of a DATA chunk, all the still
1357 * unacknowledged DATA chunks whose TSN is
1358 * older than that newly acknowledged DATA
1359 * chunk, are qualified as 'Stray DATA chunks'.
1360 */
1361 if (!tchunk->tsn_gap_acked) {
1362 tchunk->tsn_gap_acked = 1;
1363 bytes_acked += sctp_data_size(tchunk);
1364 }
1365 list_add_tail(lchunk, &tlist);
1366 }
1367
1368#if SCTP_DEBUG
1369 switch (dbg_prt_state) {
1370 case 0: /* last TSN was ACKed */
1371 if (dbg_last_ack_tsn + 1 == tsn) {
1372 /* This TSN belongs to the
1373 * current ACK range.
1374 */
1375 break;
1376 }
1377
1378 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1379 /* Display the end of the
1380 * current range.
1381 */
1382 SCTP_DEBUG_PRINTK("-%08x",
1383 dbg_last_ack_tsn);
1384 }
1385
1386 /* Start a new range. */
1387 SCTP_DEBUG_PRINTK(",%08x", tsn);
1388 dbg_ack_tsn = tsn;
1389 break;
1390
1391 case 1: /* The last TSN was NOT ACKed. */
1392 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1393 /* Display the end of current range. */
1394 SCTP_DEBUG_PRINTK("-%08x",
1395 dbg_last_kept_tsn);
1396 }
1397
1398 SCTP_DEBUG_PRINTK("\n");
1399
1400 /* FALL THROUGH... */
1401 default:
1402 /* This is the first-ever TSN we examined. */
1403 /* Start a new range of ACK-ed TSNs. */
1404 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1405 dbg_prt_state = 0;
1406 dbg_ack_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001407 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408
1409 dbg_last_ack_tsn = tsn;
1410#endif /* SCTP_DEBUG */
1411
1412 } else {
1413 if (tchunk->tsn_gap_acked) {
1414 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1415 "data TSN: 0x%x\n",
1416 __FUNCTION__,
1417 tsn);
1418 tchunk->tsn_gap_acked = 0;
1419
1420 bytes_acked -= sctp_data_size(tchunk);
1421
1422 /* RFC 2960 6.3.2 Retransmission Timer Rules
1423 *
1424 * R4) Whenever a SACK is received missing a
1425 * TSN that was previously acknowledged via a
1426 * Gap Ack Block, start T3-rtx for the
1427 * destination address to which the DATA
1428 * chunk was originally
1429 * transmitted if it is not already running.
1430 */
1431 restart_timer = 1;
1432 }
1433
1434 list_add_tail(lchunk, &tlist);
1435
1436#if SCTP_DEBUG
1437 /* See the above comments on ACK-ed TSNs. */
1438 switch (dbg_prt_state) {
1439 case 1:
1440 if (dbg_last_kept_tsn + 1 == tsn)
1441 break;
1442
1443 if (dbg_last_kept_tsn != dbg_kept_tsn)
1444 SCTP_DEBUG_PRINTK("-%08x",
1445 dbg_last_kept_tsn);
1446
1447 SCTP_DEBUG_PRINTK(",%08x", tsn);
1448 dbg_kept_tsn = tsn;
1449 break;
1450
1451 case 0:
1452 if (dbg_last_ack_tsn != dbg_ack_tsn)
1453 SCTP_DEBUG_PRINTK("-%08x",
1454 dbg_last_ack_tsn);
1455 SCTP_DEBUG_PRINTK("\n");
1456
1457 /* FALL THROUGH... */
1458 default:
1459 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1460 dbg_prt_state = 1;
1461 dbg_kept_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001462 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463
1464 dbg_last_kept_tsn = tsn;
1465#endif /* SCTP_DEBUG */
1466 }
1467 }
1468
1469#if SCTP_DEBUG
1470 /* Finish off the last range, displaying its ending TSN. */
1471 switch (dbg_prt_state) {
1472 case 0:
1473 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1474 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn);
1475 } else {
1476 SCTP_DEBUG_PRINTK("\n");
1477 }
1478 break;
1479
1480 case 1:
1481 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1482 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn);
1483 } else {
1484 SCTP_DEBUG_PRINTK("\n");
1485 }
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001486 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001487#endif /* SCTP_DEBUG */
1488 if (transport) {
1489 if (bytes_acked) {
1490 /* 8.2. When an outstanding TSN is acknowledged,
1491 * the endpoint shall clear the error counter of
1492 * the destination transport address to which the
1493 * DATA chunk was last sent.
1494 * The association's overall error counter is
1495 * also cleared.
1496 */
1497 transport->error_count = 0;
1498 transport->asoc->overall_error_count = 0;
1499
1500 /* Mark the destination transport address as
1501 * active if it is not so marked.
1502 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001503 if ((transport->state == SCTP_INACTIVE) ||
1504 (transport->state == SCTP_UNCONFIRMED)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001505 sctp_assoc_control_transport(
1506 transport->asoc,
1507 transport,
1508 SCTP_TRANSPORT_UP,
1509 SCTP_RECEIVED_SACK);
1510 }
1511
1512 sctp_transport_raise_cwnd(transport, sack_ctsn,
1513 bytes_acked);
1514
1515 transport->flight_size -= bytes_acked;
1516 q->outstanding_bytes -= bytes_acked;
1517 } else {
1518 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1519 * When a sender is doing zero window probing, it
1520 * should not timeout the association if it continues
1521 * to receive new packets from the receiver. The
1522 * reason is that the receiver MAY keep its window
1523 * closed for an indefinite time.
1524 * A sender is doing zero window probing when the
1525 * receiver's advertised window is zero, and there is
1526 * only one data chunk in flight to the receiver.
1527 */
1528 if (!q->asoc->peer.rwnd &&
1529 !list_empty(&tlist) &&
1530 (sack_ctsn+2 == q->asoc->next_tsn)) {
1531 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1532 "window probe: %u\n",
1533 __FUNCTION__, sack_ctsn);
1534 q->asoc->overall_error_count = 0;
1535 transport->error_count = 0;
1536 }
1537 }
1538
1539 /* RFC 2960 6.3.2 Retransmission Timer Rules
1540 *
1541 * R2) Whenever all outstanding data sent to an address have
1542 * been acknowledged, turn off the T3-rtx timer of that
1543 * address.
1544 */
1545 if (!transport->flight_size) {
1546 if (timer_pending(&transport->T3_rtx_timer) &&
1547 del_timer(&transport->T3_rtx_timer)) {
1548 sctp_transport_put(transport);
1549 }
1550 } else if (restart_timer) {
1551 if (!mod_timer(&transport->T3_rtx_timer,
1552 jiffies + transport->rto))
1553 sctp_transport_hold(transport);
1554 }
1555 }
1556
1557 list_splice(&tlist, transmitted_queue);
1558}
1559
1560/* Mark chunks as missing and consequently may get retransmitted. */
1561static void sctp_mark_missing(struct sctp_outq *q,
1562 struct list_head *transmitted_queue,
1563 struct sctp_transport *transport,
1564 __u32 highest_new_tsn_in_sack,
1565 int count_of_newacks)
1566{
1567 struct sctp_chunk *chunk;
1568 struct list_head *pos;
1569 __u32 tsn;
1570 char do_fast_retransmit = 0;
1571 struct sctp_transport *primary = q->asoc->peer.primary_path;
1572
1573 list_for_each(pos, transmitted_queue) {
1574
1575 chunk = list_entry(pos, struct sctp_chunk, transmitted_list);
1576 tsn = ntohl(chunk->subh.data_hdr->tsn);
1577
1578 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1579 * 'Unacknowledged TSN's', if the TSN number of an
1580 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1581 * value, increment the 'TSN.Missing.Report' count on that
1582 * chunk if it has NOT been fast retransmitted or marked for
1583 * fast retransmit already.
1584 */
1585 if (!chunk->fast_retransmit &&
1586 !chunk->tsn_gap_acked &&
1587 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1588
1589 /* SFR-CACC may require us to skip marking
1590 * this chunk as missing.
1591 */
1592 if (!transport || !sctp_cacc_skip(primary, transport,
1593 count_of_newacks, tsn)) {
1594 chunk->tsn_missing_report++;
1595
1596 SCTP_DEBUG_PRINTK(
1597 "%s: TSN 0x%x missing counter: %d\n",
1598 __FUNCTION__, tsn,
1599 chunk->tsn_missing_report);
1600 }
1601 }
1602 /*
1603 * M4) If any DATA chunk is found to have a
1604 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001605 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001606 * retransmission and start the fast retransmit procedure.
1607 */
1608
Vlad Yasevich27852c22006-02-02 16:57:31 -08001609 if (chunk->tsn_missing_report >= 3) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 chunk->fast_retransmit = 1;
1611 do_fast_retransmit = 1;
1612 }
1613 }
1614
1615 if (transport) {
1616 if (do_fast_retransmit)
1617 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1618
1619 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1620 "ssthresh: %d, flight_size: %d, pba: %d\n",
1621 __FUNCTION__, transport, transport->cwnd,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001622 transport->ssthresh, transport->flight_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 transport->partial_bytes_acked);
1624 }
1625}
1626
1627/* Is the given TSN acked by this packet? */
1628static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1629{
1630 int i;
1631 sctp_sack_variable_t *frags;
1632 __u16 gap;
1633 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1634
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001635 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636 goto pass;
1637
1638 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1639 *
1640 * Gap Ack Blocks:
1641 * These fields contain the Gap Ack Blocks. They are repeated
1642 * for each Gap Ack Block up to the number of Gap Ack Blocks
1643 * defined in the Number of Gap Ack Blocks field. All DATA
1644 * chunks with TSNs greater than or equal to (Cumulative TSN
1645 * Ack + Gap Ack Block Start) and less than or equal to
1646 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1647 * Block are assumed to have been received correctly.
1648 */
1649
1650 frags = sack->variable;
1651 gap = tsn - ctsn;
1652 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1653 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1654 TSN_lte(gap, ntohs(frags[i].gab.end)))
1655 goto pass;
1656 }
1657
1658 return 0;
1659pass:
1660 return 1;
1661}
1662
1663static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001664 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665{
1666 int i;
1667
1668 for (i = 0; i < nskips; i++) {
1669 if (skiplist[i].stream == stream)
1670 return i;
1671 }
1672 return i;
1673}
1674
1675/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1676static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1677{
1678 struct sctp_association *asoc = q->asoc;
1679 struct sctp_chunk *ftsn_chunk = NULL;
1680 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1681 int nskips = 0;
1682 int skip_pos = 0;
1683 __u32 tsn;
1684 struct sctp_chunk *chunk;
1685 struct list_head *lchunk, *temp;
1686
1687 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1688 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001689 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1691 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1692 */
1693 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1694 asoc->adv_peer_ack_point = ctsn;
1695
1696 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1697 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1698 * the chunk next in the out-queue space is marked as "abandoned" as
1699 * shown in the following example:
1700 *
1701 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1702 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001703 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1705 * normal SACK processing local advancement
1706 * ... ...
1707 * Adv.Ack.Pt-> 102 acked 102 acked
1708 * 103 abandoned 103 abandoned
1709 * 104 abandoned Adv.Ack.P-> 104 abandoned
1710 * 105 105
1711 * 106 acked 106 acked
1712 * ... ...
1713 *
1714 * In this example, the data sender successfully advanced the
1715 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1716 */
1717 list_for_each_safe(lchunk, temp, &q->abandoned) {
1718 chunk = list_entry(lchunk, struct sctp_chunk,
1719 transmitted_list);
1720 tsn = ntohl(chunk->subh.data_hdr->tsn);
1721
1722 /* Remove any chunks in the abandoned queue that are acked by
1723 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001724 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 if (TSN_lte(tsn, ctsn)) {
1726 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001727 sctp_chunk_free(chunk);
1728 } else {
1729 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1730 asoc->adv_peer_ack_point = tsn;
1731 if (chunk->chunk_hdr->flags &
1732 SCTP_DATA_UNORDERED)
1733 continue;
1734 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1735 nskips,
1736 chunk->subh.data_hdr->stream);
1737 ftsn_skip_arr[skip_pos].stream =
1738 chunk->subh.data_hdr->stream;
1739 ftsn_skip_arr[skip_pos].ssn =
1740 chunk->subh.data_hdr->ssn;
1741 if (skip_pos == nskips)
1742 nskips++;
1743 if (nskips == 10)
1744 break;
1745 } else
1746 break;
1747 }
1748 }
1749
1750 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1751 * is greater than the Cumulative TSN ACK carried in the received
1752 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1753 * chunk containing the latest value of the
1754 * "Advanced.Peer.Ack.Point".
1755 *
1756 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1757 * list each stream and sequence number in the forwarded TSN. This
1758 * information will enable the receiver to easily find any
1759 * stranded TSN's waiting on stream reorder queues. Each stream
1760 * SHOULD only be reported once; this means that if multiple
1761 * abandoned messages occur in the same stream then only the
1762 * highest abandoned stream sequence number is reported. If the
1763 * total size of the FORWARD TSN does NOT fit in a single MTU then
1764 * the sender of the FORWARD TSN SHOULD lower the
1765 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1766 * single MTU.
1767 */
1768 if (asoc->adv_peer_ack_point > ctsn)
1769 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001770 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771
1772 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001773 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001774 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1775 }
1776}