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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05007 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
9 * These functions implement the sctp_outq class. The outqueue handles
10 * bundling and queueing of outgoing SCTP chunks.
11 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050012 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * 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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050018 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * 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
Joe Perches145ce502010-08-24 13:21:08 +000049#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <linux/types.h>
52#include <linux/list.h> /* For struct list_head */
53#include <linux/socket.h>
54#include <linux/ip.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090055#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#include <net/sock.h> /* For skb_set_owner_w */
57
58#include <net/sctp/sctp.h>
59#include <net/sctp/sm.h>
60
61/* Declare internal functions here. */
62static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
63static void sctp_check_transmitted(struct sctp_outq *q,
64 struct list_head *transmitted_queue,
65 struct sctp_transport *transport,
Nicolas Dichteledfee032012-10-03 05:43:22 +000066 union sctp_addr *saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -040068 __u32 *highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70static void sctp_mark_missing(struct sctp_outq *q,
71 struct list_head *transmitted_queue,
72 struct sctp_transport *transport,
73 __u32 highest_new_tsn,
74 int count_of_newacks);
75
76static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
77
Adrian Bunkabd0b1982008-07-22 14:20:45 -070078static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout);
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080/* Add data to the front of the queue. */
81static inline void sctp_outq_head_data(struct sctp_outq *q,
82 struct sctp_chunk *ch)
83{
David S. Miller79af02c2005-07-08 21:47:49 -070084 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086}
87
88/* Take data from the front of the queue. */
89static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
90{
David S. Miller79af02c2005-07-08 21:47:49 -070091 struct sctp_chunk *ch = NULL;
92
93 if (!list_empty(&q->out_chunk_list)) {
94 struct list_head *entry = q->out_chunk_list.next;
95
96 ch = list_entry(entry, struct sctp_chunk, list);
97 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 q->out_qlen -= ch->skb->len;
David S. Miller79af02c2005-07-08 21:47:49 -070099 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 return ch;
101}
102/* Add data chunk to the end of the queue. */
103static inline void sctp_outq_tail_data(struct sctp_outq *q,
104 struct sctp_chunk *ch)
105{
David S. Miller79af02c2005-07-08 21:47:49 -0700106 list_add_tail(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108}
109
110/*
111 * SFR-CACC algorithm:
112 * D) If count_of_newacks is greater than or equal to 2
113 * and t was not sent to the current primary then the
114 * sender MUST NOT increment missing report count for t.
115 */
116static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
117 struct sctp_transport *transport,
118 int count_of_newacks)
119{
120 if (count_of_newacks >=2 && transport != primary)
121 return 1;
122 return 0;
123}
124
125/*
126 * SFR-CACC algorithm:
127 * F) If count_of_newacks is less than 2, let d be the
128 * destination to which t was sent. If cacc_saw_newack
129 * is 0 for destination d, then the sender MUST NOT
130 * increment missing report count for t.
131 */
132static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
133 int count_of_newacks)
134{
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000135 if (count_of_newacks < 2 &&
136 (transport && !transport->cacc.cacc_saw_newack))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 return 1;
138 return 0;
139}
140
141/*
142 * SFR-CACC algorithm:
143 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
144 * execute steps C, D, F.
145 *
146 * C has been implemented in sctp_outq_sack
147 */
148static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
149 struct sctp_transport *transport,
150 int count_of_newacks)
151{
152 if (!primary->cacc.cycling_changeover) {
153 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
154 return 1;
155 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
156 return 1;
157 return 0;
158 }
159 return 0;
160}
161
162/*
163 * SFR-CACC algorithm:
164 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
165 * than next_tsn_at_change of the current primary, then
166 * the sender MUST NOT increment missing report count
167 * for t.
168 */
169static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
170{
171 if (primary->cacc.cycling_changeover &&
172 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
173 return 1;
174 return 0;
175}
176
177/*
178 * SFR-CACC algorithm:
179 * 3) If the missing report count for TSN t is to be
180 * incremented according to [RFC2960] and
181 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300182 * then the sender MUST further execute steps 3.1 and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 * 3.2 to determine if the missing report count for
184 * TSN t SHOULD NOT be incremented.
185 *
186 * 3.3) If 3.1 and 3.2 do not dictate that the missing
187 * report count for t should not be incremented, then
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300188 * the sender SHOULD increment missing report count for
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
190 */
191static inline int sctp_cacc_skip(struct sctp_transport *primary,
192 struct sctp_transport *transport,
193 int count_of_newacks,
194 __u32 tsn)
195{
196 if (primary->cacc.changeover_active &&
Joe Perchesf64f9e72009-11-29 16:55:45 -0800197 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) ||
198 sctp_cacc_skip_3_2(primary, tsn)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 return 1;
200 return 0;
201}
202
203/* Initialize an existing sctp_outq. This does the boring stuff.
204 * You still need to define handlers if you really want to DO
205 * something with this structure...
206 */
207void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
208{
209 q->asoc = asoc;
David S. Miller79af02c2005-07-08 21:47:49 -0700210 INIT_LIST_HEAD(&q->out_chunk_list);
211 INIT_LIST_HEAD(&q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 INIT_LIST_HEAD(&q->retransmit);
213 INIT_LIST_HEAD(&q->sacked);
214 INIT_LIST_HEAD(&q->abandoned);
215
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700216 q->fast_rtx = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 q->outstanding_bytes = 0;
218 q->empty = 1;
219 q->cork = 0;
220
221 q->malloced = 0;
222 q->out_qlen = 0;
223}
224
225/* Free the outqueue structure and any related pending chunks.
226 */
227void sctp_outq_teardown(struct sctp_outq *q)
228{
229 struct sctp_transport *transport;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700230 struct list_head *lchunk, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700231 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
233 /* Throw away unacknowledged chunks. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700234 list_for_each_entry(transport, &q->asoc->peer.transport_addr_list,
235 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
237 chunk = list_entry(lchunk, struct sctp_chunk,
238 transmitted_list);
239 /* Mark as part of a failed message. */
240 sctp_chunk_fail(chunk, q->error);
241 sctp_chunk_free(chunk);
242 }
243 }
244
245 /* Throw away chunks that have been gap ACKed. */
246 list_for_each_safe(lchunk, temp, &q->sacked) {
247 list_del_init(lchunk);
248 chunk = list_entry(lchunk, struct sctp_chunk,
249 transmitted_list);
250 sctp_chunk_fail(chunk, q->error);
251 sctp_chunk_free(chunk);
252 }
253
254 /* Throw away any chunks in the retransmit queue. */
255 list_for_each_safe(lchunk, temp, &q->retransmit) {
256 list_del_init(lchunk);
257 chunk = list_entry(lchunk, struct sctp_chunk,
258 transmitted_list);
259 sctp_chunk_fail(chunk, q->error);
260 sctp_chunk_free(chunk);
261 }
262
263 /* Throw away any chunks that are in the abandoned queue. */
264 list_for_each_safe(lchunk, temp, &q->abandoned) {
265 list_del_init(lchunk);
266 chunk = list_entry(lchunk, struct sctp_chunk,
267 transmitted_list);
268 sctp_chunk_fail(chunk, q->error);
269 sctp_chunk_free(chunk);
270 }
271
272 /* Throw away any leftover data chunks. */
273 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
274
275 /* Mark as send failure. */
276 sctp_chunk_fail(chunk, q->error);
277 sctp_chunk_free(chunk);
278 }
279
280 q->error = 0;
281
282 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700283 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
284 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700286 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287}
288
289/* Free the outqueue structure and any related pending chunks. */
290void sctp_outq_free(struct sctp_outq *q)
291{
292 /* Throw away leftover chunks. */
293 sctp_outq_teardown(q);
294
295 /* If we were kmalloc()'d, free the memory. */
296 if (q->malloced)
297 kfree(q);
298}
299
300/* Put a new chunk in an sctp_outq. */
301int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
302{
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000303 struct net *net = sock_net(q->asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 int error = 0;
305
306 SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
307 q, chunk, chunk && chunk->chunk_hdr ?
308 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
309 : "Illegal Chunk");
310
311 /* If it is data, queue it up, otherwise, send it
312 * immediately.
313 */
Shan Weiec7b9512010-04-30 22:41:09 -0400314 if (sctp_chunk_is_data(chunk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 /* Is it OK to queue data chunks? */
316 /* From 9. Termination of Association
317 *
318 * When either endpoint performs a shutdown, the
319 * association on each peer will stop accepting new
320 * data from its user and only deliver data in queue
321 * at the time of sending or receiving the SHUTDOWN
322 * chunk.
323 */
324 switch (q->asoc->state) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 case SCTP_STATE_CLOSED:
326 case SCTP_STATE_SHUTDOWN_PENDING:
327 case SCTP_STATE_SHUTDOWN_SENT:
328 case SCTP_STATE_SHUTDOWN_RECEIVED:
329 case SCTP_STATE_SHUTDOWN_ACK_SENT:
330 /* Cannot send after transport endpoint shutdown */
331 error = -ESHUTDOWN;
332 break;
333
334 default:
335 SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
336 q, chunk, chunk && chunk->chunk_hdr ?
337 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
338 : "Illegal Chunk");
339
340 sctp_outq_tail_data(q, chunk);
341 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000342 SCTP_INC_STATS(net, SCTP_MIB_OUTUNORDERCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 else
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000344 SCTP_INC_STATS(net, SCTP_MIB_OUTORDERCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 q->empty = 0;
346 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700347 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700349 list_add_tail(&chunk->list, &q->control_chunk_list);
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000350 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 }
352
353 if (error < 0)
354 return error;
355
356 if (!q->cork)
357 error = sctp_outq_flush(q, 0);
358
359 return error;
360}
361
362/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
363 * and the abandoned list are in ascending order.
364 */
365static void sctp_insert_list(struct list_head *head, struct list_head *new)
366{
367 struct list_head *pos;
368 struct sctp_chunk *nchunk, *lchunk;
369 __u32 ntsn, ltsn;
370 int done = 0;
371
372 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
373 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
374
375 list_for_each(pos, head) {
376 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
377 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
378 if (TSN_lt(ntsn, ltsn)) {
379 list_add(new, pos->prev);
380 done = 1;
381 break;
382 }
383 }
384 if (!done)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900385 list_add_tail(new, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386}
387
388/* Mark all the eligible packets on a transport for retransmission. */
389void sctp_retransmit_mark(struct sctp_outq *q,
390 struct sctp_transport *transport,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400391 __u8 reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392{
393 struct list_head *lchunk, *ltemp;
394 struct sctp_chunk *chunk;
395
396 /* Walk through the specified transmitted queue. */
397 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
398 chunk = list_entry(lchunk, struct sctp_chunk,
399 transmitted_list);
400
401 /* If the chunk is abandoned, move it to abandoned list. */
402 if (sctp_chunk_abandoned(chunk)) {
403 list_del_init(lchunk);
404 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800405
406 /* If this chunk has not been previousely acked,
407 * stop considering it 'outstanding'. Our peer
408 * will most likely never see it since it will
409 * not be retransmitted
410 */
411 if (!chunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400412 if (chunk->transport)
413 chunk->transport->flight_size -=
414 sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800415 q->outstanding_bytes -= sctp_data_size(chunk);
Thomas Grafa76c0ad2011-12-19 04:11:40 +0000416 q->asoc->peer.rwnd += sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800417 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 continue;
419 }
420
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400421 /* If we are doing retransmission due to a timeout or pmtu
422 * discovery, only the chunks that are not yet acked should
423 * be added to the retransmit queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400425 if ((reason == SCTP_RTXR_FAST_RTX &&
Neil Hormanc226ef92008-07-25 12:44:09 -0400426 (chunk->fast_retransmit == SCTP_NEED_FRTX)) ||
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400427 (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 /* RFC 2960 6.2.1 Processing a Received SACK
429 *
430 * C) Any time a DATA chunk is marked for
431 * retransmission (via either T3-rtx timer expiration
432 * (Section 6.3.3) or via fast retransmit
433 * (Section 7.2.4)), add the data size of those
434 * chunks to the rwnd.
435 */
Thomas Grafa76c0ad2011-12-19 04:11:40 +0000436 q->asoc->peer.rwnd += sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 q->outstanding_bytes -= sctp_data_size(chunk);
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400438 if (chunk->transport)
439 transport->flight_size -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
441 /* sctpimpguide-05 Section 2.8.2
442 * M5) If a T3-rtx timer expires, the
443 * 'TSN.Missing.Report' of all affected TSNs is set
444 * to 0.
445 */
446 chunk->tsn_missing_report = 0;
447
448 /* If a chunk that is being used for RTT measurement
449 * has to be retransmitted, we cannot use this chunk
450 * anymore for RTT measurements. Reset rto_pending so
451 * that a new RTT measurement is started when a new
452 * data chunk is sent.
453 */
454 if (chunk->rtt_in_progress) {
455 chunk->rtt_in_progress = 0;
456 transport->rto_pending = 0;
457 }
458
459 /* Move the chunk to the retransmit queue. The chunks
460 * on the retransmit queue are always kept in order.
461 */
462 list_del_init(lchunk);
463 sctp_insert_list(&q->retransmit, lchunk);
464 }
465 }
466
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400467 SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 "cwnd: %d, ssthresh: %d, flight_size: %d, "
Harvey Harrison0dc47872008-03-05 20:47:47 -0800469 "pba: %d\n", __func__,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400470 transport, reason,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 transport->cwnd, transport->ssthresh,
472 transport->flight_size,
473 transport->partial_bytes_acked);
474
475}
476
477/* Mark all the eligible packets on a transport for retransmission and force
478 * one packet out.
479 */
480void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
481 sctp_retransmit_reason_t reason)
482{
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000483 struct net *net = sock_net(q->asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485
486 switch(reason) {
487 case SCTP_RTXR_T3_RTX:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000488 SCTP_INC_STATS(net, SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
490 /* Update the retran path if the T3-rtx timer has expired for
491 * the current retran path.
492 */
493 if (transport == transport->asoc->peer.retran_path)
494 sctp_assoc_update_retran_path(transport->asoc);
Neil Horman58fbbed2008-02-29 11:40:56 -0800495 transport->asoc->rtx_data_chunks +=
496 transport->asoc->unack_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 break;
498 case SCTP_RTXR_FAST_RTX:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000499 SCTP_INC_STATS(net, SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700501 q->fast_rtx = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 break;
503 case SCTP_RTXR_PMTUD:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000504 SCTP_INC_STATS(net, SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 break;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400506 case SCTP_RTXR_T1_RTX:
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000507 SCTP_INC_STATS(net, SCTP_MIB_T1_RETRANSMITS);
Neil Horman58fbbed2008-02-29 11:40:56 -0800508 transport->asoc->init_retries++;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400509 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700510 default:
511 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 }
513
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400514 sctp_retransmit_mark(q, transport, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515
516 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
517 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
518 * following the procedures outlined in C1 - C5.
519 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700520 if (reason == SCTP_RTXR_T3_RTX)
521 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700523 /* Flush the queues only on timeout, since fast_rtx is only
524 * triggered during sack processing and the queue
525 * will be flushed at the end.
526 */
527 if (reason != SCTP_RTXR_FAST_RTX)
528 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
530 if (error)
531 q->asoc->base.sk->sk_err = -error;
532}
533
534/*
535 * Transmit DATA chunks on the retransmit queue. Upon return from
536 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
537 * need to be transmitted by the caller.
538 * We assume that pkt->transport has already been set.
539 *
540 * The return value is a normal kernel error return value.
541 */
542static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
543 int rtx_timeout, int *start_timer)
544{
545 struct list_head *lqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 struct sctp_transport *transport = pkt->transport;
547 sctp_xmit_t status;
548 struct sctp_chunk *chunk, *chunk1;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700549 int fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 int error = 0;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700551 int timer = 0;
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700552 int done = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 lqueue = &q->retransmit;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700555 fast_rtx = q->fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700557 /* This loop handles time-out retransmissions, fast retransmissions,
558 * and retransmissions due to opening of whindow.
559 *
560 * RFC 2960 6.3.3 Handle T3-rtx Expiration
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 *
562 * E3) Determine how many of the earliest (i.e., lowest TSN)
563 * outstanding DATA chunks for the address for which the
564 * T3-rtx has expired will fit into a single packet, subject
565 * to the MTU constraint for the path corresponding to the
566 * destination transport address to which the retransmission
567 * is being sent (this may be different from the address for
568 * which the timer expires [see Section 6.4]). Call this value
569 * K. Bundle and retransmit those K DATA chunks in a single
570 * packet to the destination endpoint.
571 *
572 * [Just to be painfully clear, if we are retransmitting
573 * because a timeout just happened, we should send only ONE
574 * packet of retransmitted data.]
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700575 *
576 * For fast retransmissions we also send only ONE packet. However,
577 * if we are just flushing the queue due to open window, we'll
578 * try to send as much as possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700580 list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) {
Wei Yongjun4c6a6f42011-04-19 21:32:28 +0000581 /* If the chunk is abandoned, move it to abandoned list. */
582 if (sctp_chunk_abandoned(chunk)) {
583 list_del_init(&chunk->transmitted_list);
584 sctp_insert_list(&q->abandoned,
585 &chunk->transmitted_list);
586 continue;
587 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588
589 /* Make sure that Gap Acked TSNs are not retransmitted. A
590 * simple approach is just to move such TSNs out of the
591 * way and into a 'transmitted' queue and skip to the
592 * next chunk.
593 */
594 if (chunk->tsn_gap_acked) {
Wei Yongjun54a27922012-09-03 23:58:16 +0000595 list_move_tail(&chunk->transmitted_list,
596 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 continue;
598 }
599
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700600 /* If we are doing fast retransmit, ignore non-fast_rtransmit
601 * chunks
602 */
603 if (fast_rtx && !chunk->fast_retransmit)
604 continue;
605
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400606redo:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 /* Attempt to append this chunk to the packet. */
608 status = sctp_packet_append_chunk(pkt, chunk);
609
610 switch (status) {
611 case SCTP_XMIT_PMTU_FULL:
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400612 if (!pkt->has_data && !pkt->has_cookie_echo) {
613 /* If this packet did not contain DATA then
614 * retransmission did not happen, so do it
615 * again. We'll ignore the error here since
616 * control chunks are already freed so there
617 * is nothing we can do.
618 */
619 sctp_packet_transmit(pkt);
620 goto redo;
621 }
622
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700624 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
626 /* If we are retransmitting, we should only
627 * send a single packet.
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000628 * Otherwise, try appending this chunk again.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700630 if (rtx_timeout || fast_rtx)
631 done = 1;
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000632 else
633 goto redo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700635 /* Bundle next chunk in the next round. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 break;
637
638 case SCTP_XMIT_RWND_FULL:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900639 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700640 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
642 /* Stop sending DATA as there is no more room
643 * at the receiver.
644 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700645 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 break;
647
648 case SCTP_XMIT_NAGLE_DELAY:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900649 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700650 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651
652 /* Stop sending DATA because of nagle delay. */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700653 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 break;
655
656 default:
657 /* The append was successful, so add this chunk to
658 * the transmitted list.
659 */
Wei Yongjun54a27922012-09-03 23:58:16 +0000660 list_move_tail(&chunk->transmitted_list,
661 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900663 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 * after it is retransmitted.
665 */
Neil Hormanc226ef92008-07-25 12:44:09 -0400666 if (chunk->fast_retransmit == SCTP_NEED_FRTX)
667 chunk->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 q->empty = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700671 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700673 /* Set the timer if there were no errors */
674 if (!error && !timer)
675 timer = 1;
676
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700677 if (done)
678 break;
679 }
680
681 /* If we are here due to a retransmit timeout or a fast
682 * retransmit and if there are any chunks left in the retransmit
683 * queue that could not fit in the PMTU sized packet, they need
684 * to be marked as ineligible for a subsequent fast retransmit.
685 */
686 if (rtx_timeout || fast_rtx) {
687 list_for_each_entry(chunk1, lqueue, transmitted_list) {
Neil Hormanc226ef92008-07-25 12:44:09 -0400688 if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
689 chunk1->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 }
691 }
692
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700693 *start_timer = timer;
694
695 /* Clear fast retransmit hint */
696 if (fast_rtx)
697 q->fast_rtx = 0;
698
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 return error;
700}
701
702/* Cork the outqueue so queued chunks are really queued. */
703int sctp_outq_uncork(struct sctp_outq *q)
704{
705 int error = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500706 if (q->cork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 q->cork = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500708 error = sctp_outq_flush(q, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 return error;
710}
711
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713/*
714 * Try to flush an outqueue.
715 *
716 * Description: Send everything in q which we legally can, subject to
717 * congestion limitations.
718 * * Note: This function can be called from multiple contexts so appropriate
719 * locking concerns must be made. Today we use the sock lock to protect
720 * this function.
721 */
Adrian Bunkabd0b1982008-07-22 14:20:45 -0700722static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723{
724 struct sctp_packet *packet;
725 struct sctp_packet singleton;
726 struct sctp_association *asoc = q->asoc;
727 __u16 sport = asoc->base.bind_addr.port;
728 __u16 dport = asoc->peer.port;
729 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 struct sctp_transport *transport = NULL;
731 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700732 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 sctp_xmit_t status;
734 int error = 0;
735 int start_timer = 0;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700736 int one_packet = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737
738 /* These transports have chunks to send. */
739 struct list_head transport_list;
740 struct list_head *ltransport;
741
742 INIT_LIST_HEAD(&transport_list);
743 packet = NULL;
744
745 /*
746 * 6.10 Bundling
747 * ...
748 * When bundling control chunks with DATA chunks, an
749 * endpoint MUST place control chunks first in the outbound
750 * SCTP packet. The transmitter MUST transmit DATA chunks
751 * within a SCTP packet in increasing order of TSN.
752 * ...
753 */
754
David S. Miller79af02c2005-07-08 21:47:49 -0700755 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
Michio Honda8a07eb02011-04-26 20:19:36 +0900756 /* RFC 5061, 5.3
757 * F1) This means that until such time as the ASCONF
758 * containing the add is acknowledged, the sender MUST
759 * NOT use the new IP address as a source for ANY SCTP
760 * packet except on carrying an ASCONF Chunk.
761 */
762 if (asoc->src_out_of_asoc_ok &&
763 chunk->chunk_hdr->type != SCTP_CID_ASCONF)
764 continue;
765
David S. Miller79af02c2005-07-08 21:47:49 -0700766 list_del_init(&chunk->list);
767
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 /* Pick the right transport to use. */
769 new_transport = chunk->transport;
770
771 if (!new_transport) {
Vlad Yasevicha08de642007-12-20 14:11:47 -0800772 /*
773 * If we have a prior transport pointer, see if
774 * the destination address of the chunk
775 * matches the destination address of the
776 * current transport. If not a match, then
777 * try to look up the transport with a given
778 * destination address. We do this because
779 * after processing ASCONFs, we may have new
780 * transports created.
781 */
782 if (transport &&
783 sctp_cmp_addr_exact(&chunk->dest,
784 &transport->ipaddr))
785 new_transport = transport;
786 else
787 new_transport = sctp_assoc_lookup_paddr(asoc,
788 &chunk->dest);
789
790 /* if we still don't have a new transport, then
791 * use the current active path.
792 */
793 if (!new_transport)
794 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700795 } else if ((new_transport->state == SCTP_INACTIVE) ||
Neil Horman5aa93bc2012-07-21 07:56:07 +0000796 (new_transport->state == SCTP_UNCONFIRMED) ||
797 (new_transport->state == SCTP_PF)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700798 /* If the chunk is Heartbeat or Heartbeat Ack,
799 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 * inactive.
801 *
802 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900803 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 * A HEARTBEAT ACK is always sent to the source IP
805 * address of the IP datagram containing the
806 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900807 * ...
Vlad Yasevicha08de642007-12-20 14:11:47 -0800808 *
809 * ASCONF_ACKs also must be sent to the source.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 */
811 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
Vlad Yasevicha08de642007-12-20 14:11:47 -0800812 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
813 chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 new_transport = asoc->peer.active_path;
815 }
816
817 /* Are we switching transports?
818 * Take care of transport locks.
819 */
820 if (new_transport != transport) {
821 transport = new_transport;
822 if (list_empty(&transport->send_ready)) {
823 list_add_tail(&transport->send_ready,
824 &transport_list);
825 }
826 packet = &transport->packet;
827 sctp_packet_config(packet, vtag,
828 asoc->peer.ecn_capable);
829 }
830
831 switch (chunk->chunk_hdr->type) {
832 /*
833 * 6.10 Bundling
834 * ...
835 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
836 * COMPLETE with any other chunks. [Send them immediately.]
837 */
838 case SCTP_CID_INIT:
839 case SCTP_CID_INIT_ACK:
840 case SCTP_CID_SHUTDOWN_COMPLETE:
841 sctp_packet_init(&singleton, transport, sport, dport);
842 sctp_packet_config(&singleton, vtag, 0);
843 sctp_packet_append_chunk(&singleton, chunk);
844 error = sctp_packet_transmit(&singleton);
845 if (error < 0)
846 return error;
847 break;
848
849 case SCTP_CID_ABORT:
Gui Jianfengf4ad85c2008-04-12 18:39:34 -0700850 if (sctp_test_T_bit(chunk)) {
851 packet->vtag = asoc->c.my_vtag;
852 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700853 /* The following chunks are "response" chunks, i.e.
854 * they are generated in response to something we
855 * received. If we are sending these, then we can
856 * send only 1 packet containing these chunks.
857 */
858 case SCTP_CID_HEARTBEAT_ACK:
859 case SCTP_CID_SHUTDOWN_ACK:
860 case SCTP_CID_COOKIE_ACK:
861 case SCTP_CID_COOKIE_ECHO:
862 case SCTP_CID_ERROR:
863 case SCTP_CID_ECN_CWR:
864 case SCTP_CID_ASCONF_ACK:
865 one_packet = 1;
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300866 /* Fall through */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700867
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 case SCTP_CID_SACK:
869 case SCTP_CID_HEARTBEAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 case SCTP_CID_SHUTDOWN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 case SCTP_CID_ECN_ECNE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 case SCTP_CID_ASCONF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 case SCTP_CID_FWD_TSN:
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700874 status = sctp_packet_transmit_chunk(packet, chunk,
875 one_packet);
876 if (status != SCTP_XMIT_OK) {
877 /* put the chunk back */
878 list_add(&chunk->list, &q->control_chunk_list);
Wei Yongjunbd69b982010-04-30 21:42:43 -0400879 } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
880 /* PR-SCTP C5) If a FORWARD TSN is sent, the
881 * sender MUST assure that at least one T3-rtx
882 * timer is running.
883 */
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400884 sctp_transport_reset_timers(transport);
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700885 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 break;
887
888 default:
889 /* We built a chunk with an illegal type! */
890 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 }
893
Michio Honda8a07eb02011-04-26 20:19:36 +0900894 if (q->asoc->src_out_of_asoc_ok)
895 goto sctp_flush_out;
896
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 /* Is it OK to send data chunks? */
898 switch (asoc->state) {
899 case SCTP_STATE_COOKIE_ECHOED:
900 /* Only allow bundling when this packet has a COOKIE-ECHO
901 * chunk.
902 */
903 if (!packet || !packet->has_cookie_echo)
904 break;
905
906 /* fallthru */
907 case SCTP_STATE_ESTABLISHED:
908 case SCTP_STATE_SHUTDOWN_PENDING:
909 case SCTP_STATE_SHUTDOWN_RECEIVED:
910 /*
911 * RFC 2960 6.1 Transmission of DATA Chunks
912 *
913 * C) When the time comes for the sender to transmit,
914 * before sending new DATA chunks, the sender MUST
915 * first transmit any outstanding DATA chunks which
916 * are marked for retransmission (limited by the
917 * current cwnd).
918 */
919 if (!list_empty(&q->retransmit)) {
Michio Hondaf207c052011-06-16 10:54:23 +0900920 if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED)
921 goto sctp_flush_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 if (transport == asoc->peer.retran_path)
923 goto retran;
924
925 /* Switch transports & prepare the packet. */
926
927 transport = asoc->peer.retran_path;
928
929 if (list_empty(&transport->send_ready)) {
930 list_add_tail(&transport->send_ready,
931 &transport_list);
932 }
933
934 packet = &transport->packet;
935 sctp_packet_config(packet, vtag,
936 asoc->peer.ecn_capable);
937 retran:
938 error = sctp_outq_flush_rtx(q, packet,
939 rtx_timeout, &start_timer);
940
941 if (start_timer)
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400942 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943
944 /* This can happen on COOKIE-ECHO resend. Only
945 * one chunk can get bundled with a COOKIE-ECHO.
946 */
947 if (packet->has_cookie_echo)
948 goto sctp_flush_out;
949
950 /* Don't send new data if there is still data
951 * waiting to retransmit.
952 */
953 if (!list_empty(&q->retransmit))
954 goto sctp_flush_out;
955 }
956
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500957 /* Apply Max.Burst limitation to the current transport in
958 * case it will be used for new data. We are going to
959 * rest it before we return, but we want to apply the limit
960 * to the currently queued data.
961 */
962 if (transport)
963 sctp_transport_burst_limited(transport);
964
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 /* Finally, transmit new packets. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
967 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
968 * stream identifier.
969 */
970 if (chunk->sinfo.sinfo_stream >=
971 asoc->c.sinit_num_ostreams) {
972
973 /* Mark as failed send. */
974 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
975 sctp_chunk_free(chunk);
976 continue;
977 }
978
979 /* Has this chunk expired? */
980 if (sctp_chunk_abandoned(chunk)) {
981 sctp_chunk_fail(chunk, 0);
982 sctp_chunk_free(chunk);
983 continue;
984 }
985
986 /* If there is a specified transport, use it.
987 * Otherwise, we want to use the active path.
988 */
989 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700990 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700991 ((new_transport->state == SCTP_INACTIVE) ||
Neil Horman5aa93bc2012-07-21 07:56:07 +0000992 (new_transport->state == SCTP_UNCONFIRMED) ||
993 (new_transport->state == SCTP_PF)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 new_transport = asoc->peer.active_path;
Michio Hondaf207c052011-06-16 10:54:23 +0900995 if (new_transport->state == SCTP_UNCONFIRMED)
996 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
998 /* Change packets if necessary. */
999 if (new_transport != transport) {
1000 transport = new_transport;
1001
1002 /* Schedule to have this transport's
1003 * packet flushed.
1004 */
1005 if (list_empty(&transport->send_ready)) {
1006 list_add_tail(&transport->send_ready,
1007 &transport_list);
1008 }
1009
1010 packet = &transport->packet;
1011 sctp_packet_config(packet, vtag,
1012 asoc->peer.ecn_capable);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001013 /* We've switched transports, so apply the
1014 * Burst limit to the new transport.
1015 */
1016 sctp_transport_burst_limited(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 }
1018
1019 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
1020 q, chunk,
1021 chunk && chunk->chunk_hdr ?
1022 sctp_cname(SCTP_ST_CHUNK(
1023 chunk->chunk_hdr->type))
1024 : "Illegal Chunk");
1025
1026 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
1027 "%p skb->users %d.\n",
1028 ntohl(chunk->subh.data_hdr->tsn),
1029 chunk->skb ?chunk->skb->head : NULL,
1030 chunk->skb ?
1031 atomic_read(&chunk->skb->users) : -1);
1032
1033 /* Add the chunk to the packet. */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07001034 status = sctp_packet_transmit_chunk(packet, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035
1036 switch (status) {
1037 case SCTP_XMIT_PMTU_FULL:
1038 case SCTP_XMIT_RWND_FULL:
1039 case SCTP_XMIT_NAGLE_DELAY:
1040 /* We could not append this chunk, so put
1041 * the chunk back on the output queue.
1042 */
1043 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
1044 "not transmit TSN: 0x%x, status: %d\n",
1045 ntohl(chunk->subh.data_hdr->tsn),
1046 status);
1047 sctp_outq_head_data(q, chunk);
1048 goto sctp_flush_out;
1049 break;
1050
1051 case SCTP_XMIT_OK:
Wei Yongjunb93d6472009-11-23 15:53:56 -05001052 /* The sender is in the SHUTDOWN-PENDING state,
1053 * The sender MAY set the I-bit in the DATA
1054 * chunk header.
1055 */
1056 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
1057 chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
1058
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 break;
1060
1061 default:
1062 BUG();
1063 }
1064
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001065 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 * call below will succeed all the time and add the
1067 * chunk to the transmitted list and restart the
1068 * timers.
1069 * It is possible that the call can fail under OOM
1070 * conditions.
1071 *
1072 * Is this really a problem? Won't this behave
1073 * like a lost TSN?
1074 */
1075 list_add_tail(&chunk->transmitted_list,
1076 &transport->transmitted);
1077
Vlad Yasevichd9efc222010-04-30 22:41:09 -04001078 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079
1080 q->empty = 0;
1081
1082 /* Only let one DATA chunk get bundled with a
1083 * COOKIE-ECHO chunk.
1084 */
1085 if (packet->has_cookie_echo)
1086 goto sctp_flush_out;
1087 }
1088 break;
1089
1090 default:
1091 /* Do nothing. */
1092 break;
1093 }
1094
1095sctp_flush_out:
1096
1097 /* Before returning, examine all the transports touched in
1098 * this call. Right now, we bluntly force clear all the
1099 * transports. Things might change after we implement Nagle.
1100 * But such an examination is still required.
1101 *
1102 * --xguo
1103 */
1104 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
1105 struct sctp_transport *t = list_entry(ltransport,
1106 struct sctp_transport,
1107 send_ready);
1108 packet = &t->packet;
1109 if (!sctp_packet_empty(packet))
1110 error = sctp_packet_transmit(packet);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001111
1112 /* Clear the burst limited state, if any */
1113 sctp_transport_burst_reset(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 }
1115
1116 return error;
1117}
1118
1119/* Update unack_data based on the incoming SACK chunk */
1120static void sctp_sack_update_unack_data(struct sctp_association *assoc,
1121 struct sctp_sackhdr *sack)
1122{
1123 sctp_sack_variable_t *frags;
1124 __u16 unack_data;
1125 int i;
1126
1127 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
1128
1129 frags = sack->variable;
1130 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1131 unack_data -= ((ntohs(frags[i].gab.end) -
1132 ntohs(frags[i].gab.start) + 1));
1133 }
1134
1135 assoc->unack_data = unack_data;
1136}
1137
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138/* This is where we REALLY process a SACK.
1139 *
1140 * Process the SACK against the outqueue. Mostly, this just frees
1141 * things off the transmitted queue.
1142 */
Nicolas Dichteledfee032012-10-03 05:43:22 +00001143int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144{
1145 struct sctp_association *asoc = q->asoc;
Nicolas Dichteledfee032012-10-03 05:43:22 +00001146 struct sctp_sackhdr *sack = chunk->subh.sack_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 struct sctp_transport *transport;
1148 struct sctp_chunk *tchunk = NULL;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001149 struct list_head *lchunk, *transport_list, *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 sctp_sack_variable_t *frags = sack->variable;
1151 __u32 sack_ctsn, ctsn, tsn;
1152 __u32 highest_tsn, highest_new_tsn;
1153 __u32 sack_a_rwnd;
Eric Dumazet95c96172012-04-15 05:58:06 +00001154 unsigned int outstanding;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155 struct sctp_transport *primary = asoc->peer.primary_path;
1156 int count_of_newacks = 0;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001157 int gap_ack_blocks;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001158 u8 accum_moved = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159
1160 /* Grab the association's destination address list. */
1161 transport_list = &asoc->peer.transport_addr_list;
1162
1163 sack_ctsn = ntohl(sack->cum_tsn_ack);
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001164 gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 /*
1166 * SFR-CACC algorithm:
1167 * On receipt of a SACK the sender SHOULD execute the
1168 * following statements.
1169 *
1170 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1171 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1172 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1173 * all destinations.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1175 * is set the receiver of the SACK MUST take the following actions:
1176 *
1177 * A) Initialize the cacc_saw_newack to 0 for all destination
1178 * addresses.
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001179 *
1180 * Only bother if changeover_active is set. Otherwise, this is
1181 * totally suboptimal to do on every SACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 */
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001183 if (primary->cacc.changeover_active) {
1184 u8 clear_cycling = 0;
1185
1186 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1187 primary->cacc.changeover_active = 0;
1188 clear_cycling = 1;
1189 }
1190
1191 if (clear_cycling || gap_ack_blocks) {
1192 list_for_each_entry(transport, transport_list,
1193 transports) {
1194 if (clear_cycling)
1195 transport->cacc.cycling_changeover = 0;
1196 if (gap_ack_blocks)
1197 transport->cacc.cacc_saw_newack = 0;
1198 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 }
1200 }
1201
1202 /* Get the highest TSN in the sack. */
1203 highest_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001204 if (gap_ack_blocks)
1205 highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001207 if (TSN_lt(asoc->highest_sacked, highest_tsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 asoc->highest_sacked = highest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001210 highest_new_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001211
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 /* Run through the retransmit queue. Credit bytes received
1213 * and free those chunks that we can.
1214 */
Nicolas Dichteledfee032012-10-03 05:43:22 +00001215 sctp_check_transmitted(q, &q->retransmit, NULL, NULL, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216
1217 /* Run through the transmitted queue.
1218 * Credit bytes received and free those chunks which we can.
1219 *
1220 * This is a MASSIVE candidate for optimization.
1221 */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001222 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 sctp_check_transmitted(q, &transport->transmitted,
Nicolas Dichteledfee032012-10-03 05:43:22 +00001224 transport, &chunk->source, sack,
1225 &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 /*
1227 * SFR-CACC algorithm:
1228 * C) Let count_of_newacks be the number of
1229 * destinations for which cacc_saw_newack is set.
1230 */
1231 if (transport->cacc.cacc_saw_newack)
1232 count_of_newacks ++;
1233 }
1234
Vlad Yasevichea862c82010-04-30 22:41:10 -04001235 /* Move the Cumulative TSN Ack Point if appropriate. */
1236 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) {
1237 asoc->ctsn_ack_point = sack_ctsn;
1238 accum_moved = 1;
1239 }
1240
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001241 if (gap_ack_blocks) {
Vlad Yasevichea862c82010-04-30 22:41:10 -04001242
1243 if (asoc->fast_recovery && accum_moved)
1244 highest_new_tsn = highest_tsn;
1245
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001246 list_for_each_entry(transport, transport_list, transports)
1247 sctp_mark_missing(q, &transport->transmitted, transport,
1248 highest_new_tsn, count_of_newacks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 }
1250
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 /* Update unack_data field in the assoc. */
1252 sctp_sack_update_unack_data(asoc, sack);
1253
1254 ctsn = asoc->ctsn_ack_point;
1255
1256 /* Throw away stuff rotting on the sack queue. */
1257 list_for_each_safe(lchunk, temp, &q->sacked) {
1258 tchunk = list_entry(lchunk, struct sctp_chunk,
1259 transmitted_list);
1260 tsn = ntohl(tchunk->subh.data_hdr->tsn);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001261 if (TSN_lte(tsn, ctsn)) {
1262 list_del_init(&tchunk->transmitted_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 sctp_chunk_free(tchunk);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001264 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265 }
1266
1267 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1268 * number of bytes still outstanding after processing the
1269 * Cumulative TSN Ack and the Gap Ack Blocks.
1270 */
1271
1272 sack_a_rwnd = ntohl(sack->a_rwnd);
1273 outstanding = q->outstanding_bytes;
1274
1275 if (outstanding < sack_a_rwnd)
1276 sack_a_rwnd -= outstanding;
1277 else
1278 sack_a_rwnd = 0;
1279
1280 asoc->peer.rwnd = sack_a_rwnd;
1281
1282 sctp_generate_fwdtsn(q, sack_ctsn);
1283
1284 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001285 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1287 "%p is 0x%x. Adv peer ack point: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001288 __func__, asoc, ctsn, asoc->adv_peer_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289
1290 /* See if all chunks are acked.
1291 * Make sure the empty queue handler will get run later.
1292 */
David S. Miller79af02c2005-07-08 21:47:49 -07001293 q->empty = (list_empty(&q->out_chunk_list) &&
David S. Miller79af02c2005-07-08 21:47:49 -07001294 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 if (!q->empty)
1296 goto finish;
1297
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001298 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 q->empty = q->empty && list_empty(&transport->transmitted);
1300 if (!q->empty)
1301 goto finish;
1302 }
1303
1304 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1305finish:
1306 return q->empty;
1307}
1308
1309/* Is the outqueue empty? */
1310int sctp_outq_is_empty(const struct sctp_outq *q)
1311{
1312 return q->empty;
1313}
1314
1315/********************************************************************
1316 * 2nd Level Abstractions
1317 ********************************************************************/
1318
1319/* Go through a transport's transmitted list or the association's retransmit
1320 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1321 * The retransmit list will not have an associated transport.
1322 *
1323 * I added coherent debug information output. --xguo
1324 *
1325 * Instead of printing 'sacked' or 'kept' for each TSN on the
1326 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1327 * KEPT TSN6-TSN7, etc.
1328 */
1329static void sctp_check_transmitted(struct sctp_outq *q,
1330 struct list_head *transmitted_queue,
1331 struct sctp_transport *transport,
Nicolas Dichteledfee032012-10-03 05:43:22 +00001332 union sctp_addr *saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001334 __u32 *highest_new_tsn_in_sack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335{
1336 struct list_head *lchunk;
1337 struct sctp_chunk *tchunk;
1338 struct list_head tlist;
1339 __u32 tsn;
1340 __u32 sack_ctsn;
1341 __u32 rtt;
1342 __u8 restart_timer = 0;
1343 int bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001344 int migrate_bytes = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345
1346 /* These state variables are for coherent debug output. --xguo */
1347
1348#if SCTP_DEBUG
1349 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1350 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1351 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1352 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1353
1354 /* 0 : The last TSN was ACKed.
1355 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1356 * -1: We need to initialize.
1357 */
1358 int dbg_prt_state = -1;
1359#endif /* SCTP_DEBUG */
1360
1361 sack_ctsn = ntohl(sack->cum_tsn_ack);
1362
1363 INIT_LIST_HEAD(&tlist);
1364
1365 /* The while loop will skip empty transmitted queues. */
1366 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1367 tchunk = list_entry(lchunk, struct sctp_chunk,
1368 transmitted_list);
1369
1370 if (sctp_chunk_abandoned(tchunk)) {
1371 /* Move the chunk to abandoned list. */
1372 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001373
1374 /* If this chunk has not been acked, stop
1375 * considering it as 'outstanding'.
1376 */
1377 if (!tchunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001378 if (tchunk->transport)
1379 tchunk->transport->flight_size -=
1380 sctp_data_size(tchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001381 q->outstanding_bytes -= sctp_data_size(tchunk);
1382 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 continue;
1384 }
1385
1386 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1387 if (sctp_acked(sack, tsn)) {
1388 /* If this queue is the retransmit queue, the
1389 * retransmit timer has already reclaimed
1390 * the outstanding bytes for this chunk, so only
1391 * count bytes associated with a transport.
1392 */
1393 if (transport) {
1394 /* If this chunk is being used for RTT
1395 * measurement, calculate the RTT and update
1396 * the RTO using this value.
1397 *
1398 * 6.3.1 C5) Karn's algorithm: RTT measurements
1399 * MUST NOT be made using packets that were
1400 * retransmitted (and thus for which it is
1401 * ambiguous whether the reply was for the
1402 * first instance of the packet or a later
1403 * instance).
1404 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001405 if (!tchunk->tsn_gap_acked &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001407 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408 rtt = jiffies - tchunk->sent_at;
1409 sctp_transport_update_rto(transport,
1410 rtt);
1411 }
1412 }
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001413
1414 /* If the chunk hasn't been marked as ACKED,
1415 * mark it and account bytes_acked if the
1416 * chunk had a valid transport (it will not
1417 * have a transport if ASCONF had deleted it
1418 * while DATA was outstanding).
1419 */
1420 if (!tchunk->tsn_gap_acked) {
1421 tchunk->tsn_gap_acked = 1;
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001422 *highest_new_tsn_in_sack = tsn;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001423 bytes_acked += sctp_data_size(tchunk);
1424 if (!tchunk->transport)
1425 migrate_bytes += sctp_data_size(tchunk);
1426 }
1427
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001428 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 /* RFC 2960 6.3.2 Retransmission Timer Rules
1430 *
1431 * R3) Whenever a SACK is received
1432 * that acknowledges the DATA chunk
1433 * with the earliest outstanding TSN
1434 * for that address, restart T3-rtx
1435 * timer for that address with its
1436 * current RTO.
1437 */
1438 restart_timer = 1;
1439
1440 if (!tchunk->tsn_gap_acked) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 /*
1442 * SFR-CACC algorithm:
1443 * 2) If the SACK contains gap acks
1444 * and the flag CHANGEOVER_ACTIVE is
1445 * set the receiver of the SACK MUST
1446 * take the following action:
1447 *
1448 * B) For each TSN t being acked that
1449 * has not been acked in any SACK so
1450 * far, set cacc_saw_newack to 1 for
1451 * the destination that the TSN was
1452 * sent to.
1453 */
1454 if (transport &&
1455 sack->num_gap_ack_blocks &&
1456 q->asoc->peer.primary_path->cacc.
1457 changeover_active)
1458 transport->cacc.cacc_saw_newack
1459 = 1;
1460 }
1461
1462 list_add_tail(&tchunk->transmitted_list,
1463 &q->sacked);
1464 } else {
1465 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1466 * M2) Each time a SACK arrives reporting
1467 * 'Stray DATA chunk(s)' record the highest TSN
1468 * reported as newly acknowledged, call this
1469 * value 'HighestTSNinSack'. A newly
1470 * acknowledged DATA chunk is one not
1471 * previously acknowledged in a SACK.
1472 *
1473 * When the SCTP sender of data receives a SACK
1474 * chunk that acknowledges, for the first time,
1475 * the receipt of a DATA chunk, all the still
1476 * unacknowledged DATA chunks whose TSN is
1477 * older than that newly acknowledged DATA
1478 * chunk, are qualified as 'Stray DATA chunks'.
1479 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480 list_add_tail(lchunk, &tlist);
1481 }
1482
1483#if SCTP_DEBUG
1484 switch (dbg_prt_state) {
1485 case 0: /* last TSN was ACKed */
1486 if (dbg_last_ack_tsn + 1 == tsn) {
1487 /* This TSN belongs to the
1488 * current ACK range.
1489 */
1490 break;
1491 }
1492
1493 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1494 /* Display the end of the
1495 * current range.
1496 */
Joe Perches145ce502010-08-24 13:21:08 +00001497 SCTP_DEBUG_PRINTK_CONT("-%08x",
1498 dbg_last_ack_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 }
1500
1501 /* Start a new range. */
Joe Perches145ce502010-08-24 13:21:08 +00001502 SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503 dbg_ack_tsn = tsn;
1504 break;
1505
1506 case 1: /* The last TSN was NOT ACKed. */
1507 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1508 /* Display the end of current range. */
Joe Perches145ce502010-08-24 13:21:08 +00001509 SCTP_DEBUG_PRINTK_CONT("-%08x",
1510 dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 }
1512
Joe Perches145ce502010-08-24 13:21:08 +00001513 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001514
1515 /* FALL THROUGH... */
1516 default:
1517 /* This is the first-ever TSN we examined. */
1518 /* Start a new range of ACK-ed TSNs. */
1519 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1520 dbg_prt_state = 0;
1521 dbg_ack_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001522 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001523
1524 dbg_last_ack_tsn = tsn;
1525#endif /* SCTP_DEBUG */
1526
1527 } else {
1528 if (tchunk->tsn_gap_acked) {
1529 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1530 "data TSN: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001531 __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001532 tsn);
1533 tchunk->tsn_gap_acked = 0;
1534
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001535 if (tchunk->transport)
1536 bytes_acked -= sctp_data_size(tchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537
1538 /* RFC 2960 6.3.2 Retransmission Timer Rules
1539 *
1540 * R4) Whenever a SACK is received missing a
1541 * TSN that was previously acknowledged via a
1542 * Gap Ack Block, start T3-rtx for the
1543 * destination address to which the DATA
1544 * chunk was originally
1545 * transmitted if it is not already running.
1546 */
1547 restart_timer = 1;
1548 }
1549
1550 list_add_tail(lchunk, &tlist);
1551
1552#if SCTP_DEBUG
1553 /* See the above comments on ACK-ed TSNs. */
1554 switch (dbg_prt_state) {
1555 case 1:
1556 if (dbg_last_kept_tsn + 1 == tsn)
1557 break;
1558
1559 if (dbg_last_kept_tsn != dbg_kept_tsn)
Joe Perches145ce502010-08-24 13:21:08 +00001560 SCTP_DEBUG_PRINTK_CONT("-%08x",
1561 dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562
Joe Perches145ce502010-08-24 13:21:08 +00001563 SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564 dbg_kept_tsn = tsn;
1565 break;
1566
1567 case 0:
1568 if (dbg_last_ack_tsn != dbg_ack_tsn)
Joe Perches145ce502010-08-24 13:21:08 +00001569 SCTP_DEBUG_PRINTK_CONT("-%08x",
1570 dbg_last_ack_tsn);
1571 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572
1573 /* FALL THROUGH... */
1574 default:
1575 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1576 dbg_prt_state = 1;
1577 dbg_kept_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001578 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579
1580 dbg_last_kept_tsn = tsn;
1581#endif /* SCTP_DEBUG */
1582 }
1583 }
1584
1585#if SCTP_DEBUG
1586 /* Finish off the last range, displaying its ending TSN. */
1587 switch (dbg_prt_state) {
1588 case 0:
1589 if (dbg_last_ack_tsn != dbg_ack_tsn) {
Joe Perches145ce502010-08-24 13:21:08 +00001590 SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_ack_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591 } else {
Joe Perches145ce502010-08-24 13:21:08 +00001592 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001593 }
1594 break;
1595
1596 case 1:
1597 if (dbg_last_kept_tsn != dbg_kept_tsn) {
Joe Perches145ce502010-08-24 13:21:08 +00001598 SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599 } else {
Joe Perches145ce502010-08-24 13:21:08 +00001600 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001601 }
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001602 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603#endif /* SCTP_DEBUG */
1604 if (transport) {
1605 if (bytes_acked) {
Thomas Graff8d96052011-07-07 00:28:35 +00001606 struct sctp_association *asoc = transport->asoc;
1607
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001608 /* We may have counted DATA that was migrated
1609 * to this transport due to DEL-IP operation.
1610 * Subtract those bytes, since the were never
1611 * send on this transport and shouldn't be
1612 * credited to this transport.
1613 */
1614 bytes_acked -= migrate_bytes;
1615
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616 /* 8.2. When an outstanding TSN is acknowledged,
1617 * the endpoint shall clear the error counter of
1618 * the destination transport address to which the
1619 * DATA chunk was last sent.
1620 * The association's overall error counter is
1621 * also cleared.
1622 */
1623 transport->error_count = 0;
1624 transport->asoc->overall_error_count = 0;
1625
Thomas Graff8d96052011-07-07 00:28:35 +00001626 /*
1627 * While in SHUTDOWN PENDING, we may have started
1628 * the T5 shutdown guard timer after reaching the
1629 * retransmission limit. Stop that timer as soon
1630 * as the receiver acknowledged any data.
1631 */
1632 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING &&
1633 del_timer(&asoc->timers
1634 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]))
1635 sctp_association_put(asoc);
1636
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 /* Mark the destination transport address as
1638 * active if it is not so marked.
1639 */
Nicolas Dichteledfee032012-10-03 05:43:22 +00001640 if ((transport->state == SCTP_INACTIVE ||
1641 transport->state == SCTP_UNCONFIRMED) &&
1642 sctp_cmp_addr_exact(&transport->ipaddr, saddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 sctp_assoc_control_transport(
1644 transport->asoc,
1645 transport,
1646 SCTP_TRANSPORT_UP,
1647 SCTP_RECEIVED_SACK);
1648 }
1649
1650 sctp_transport_raise_cwnd(transport, sack_ctsn,
1651 bytes_acked);
1652
1653 transport->flight_size -= bytes_acked;
Gui Jianfeng8b73a072008-04-17 14:22:18 -07001654 if (transport->flight_size == 0)
1655 transport->partial_bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001656 q->outstanding_bytes -= bytes_acked + migrate_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657 } else {
1658 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1659 * When a sender is doing zero window probing, it
1660 * should not timeout the association if it continues
1661 * to receive new packets from the receiver. The
1662 * reason is that the receiver MAY keep its window
1663 * closed for an indefinite time.
1664 * A sender is doing zero window probing when the
1665 * receiver's advertised window is zero, and there is
1666 * only one data chunk in flight to the receiver.
Thomas Graff8d96052011-07-07 00:28:35 +00001667 *
1668 * Allow the association to timeout while in SHUTDOWN
1669 * PENDING or SHUTDOWN RECEIVED in case the receiver
1670 * stays in zero window mode forever.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671 */
1672 if (!q->asoc->peer.rwnd &&
1673 !list_empty(&tlist) &&
Thomas Graff8d96052011-07-07 00:28:35 +00001674 (sack_ctsn+2 == q->asoc->next_tsn) &&
1675 q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1677 "window probe: %u\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001678 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679 q->asoc->overall_error_count = 0;
1680 transport->error_count = 0;
1681 }
1682 }
1683
1684 /* RFC 2960 6.3.2 Retransmission Timer Rules
1685 *
1686 * R2) Whenever all outstanding data sent to an address have
1687 * been acknowledged, turn off the T3-rtx timer of that
1688 * address.
1689 */
1690 if (!transport->flight_size) {
1691 if (timer_pending(&transport->T3_rtx_timer) &&
1692 del_timer(&transport->T3_rtx_timer)) {
1693 sctp_transport_put(transport);
1694 }
1695 } else if (restart_timer) {
1696 if (!mod_timer(&transport->T3_rtx_timer,
1697 jiffies + transport->rto))
1698 sctp_transport_hold(transport);
1699 }
1700 }
1701
1702 list_splice(&tlist, transmitted_queue);
1703}
1704
1705/* Mark chunks as missing and consequently may get retransmitted. */
1706static void sctp_mark_missing(struct sctp_outq *q,
1707 struct list_head *transmitted_queue,
1708 struct sctp_transport *transport,
1709 __u32 highest_new_tsn_in_sack,
1710 int count_of_newacks)
1711{
1712 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001713 __u32 tsn;
1714 char do_fast_retransmit = 0;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001715 struct sctp_association *asoc = q->asoc;
1716 struct sctp_transport *primary = asoc->peer.primary_path;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001718 list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 tsn = ntohl(chunk->subh.data_hdr->tsn);
1721
1722 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1723 * 'Unacknowledged TSN's', if the TSN number of an
1724 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1725 * value, increment the 'TSN.Missing.Report' count on that
1726 * chunk if it has NOT been fast retransmitted or marked for
1727 * fast retransmit already.
1728 */
Neil Hormanc226ef92008-07-25 12:44:09 -04001729 if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730 !chunk->tsn_gap_acked &&
1731 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1732
1733 /* SFR-CACC may require us to skip marking
1734 * this chunk as missing.
1735 */
Vlad Yasevichf246a7b2011-04-18 19:13:56 +00001736 if (!transport || !sctp_cacc_skip(primary,
1737 chunk->transport,
1738 count_of_newacks, tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001739 chunk->tsn_missing_report++;
1740
1741 SCTP_DEBUG_PRINTK(
1742 "%s: TSN 0x%x missing counter: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001743 __func__, tsn,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001744 chunk->tsn_missing_report);
1745 }
1746 }
1747 /*
1748 * M4) If any DATA chunk is found to have a
1749 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001750 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001751 * retransmission and start the fast retransmit procedure.
1752 */
1753
Vlad Yasevich27852c22006-02-02 16:57:31 -08001754 if (chunk->tsn_missing_report >= 3) {
Neil Hormanc226ef92008-07-25 12:44:09 -04001755 chunk->fast_retransmit = SCTP_NEED_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756 do_fast_retransmit = 1;
1757 }
1758 }
1759
1760 if (transport) {
1761 if (do_fast_retransmit)
1762 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1763
1764 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1765 "ssthresh: %d, flight_size: %d, pba: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001766 __func__, transport, transport->cwnd,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001767 transport->ssthresh, transport->flight_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768 transport->partial_bytes_acked);
1769 }
1770}
1771
1772/* Is the given TSN acked by this packet? */
1773static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1774{
1775 int i;
1776 sctp_sack_variable_t *frags;
1777 __u16 gap;
1778 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1779
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001780 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781 goto pass;
1782
1783 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1784 *
1785 * Gap Ack Blocks:
1786 * These fields contain the Gap Ack Blocks. They are repeated
1787 * for each Gap Ack Block up to the number of Gap Ack Blocks
1788 * defined in the Number of Gap Ack Blocks field. All DATA
1789 * chunks with TSNs greater than or equal to (Cumulative TSN
1790 * Ack + Gap Ack Block Start) and less than or equal to
1791 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1792 * Block are assumed to have been received correctly.
1793 */
1794
1795 frags = sack->variable;
1796 gap = tsn - ctsn;
1797 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1798 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1799 TSN_lte(gap, ntohs(frags[i].gab.end)))
1800 goto pass;
1801 }
1802
1803 return 0;
1804pass:
1805 return 1;
1806}
1807
1808static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001809 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001810{
1811 int i;
1812
1813 for (i = 0; i < nskips; i++) {
1814 if (skiplist[i].stream == stream)
1815 return i;
1816 }
1817 return i;
1818}
1819
1820/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1821static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1822{
1823 struct sctp_association *asoc = q->asoc;
1824 struct sctp_chunk *ftsn_chunk = NULL;
1825 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1826 int nskips = 0;
1827 int skip_pos = 0;
1828 __u32 tsn;
1829 struct sctp_chunk *chunk;
1830 struct list_head *lchunk, *temp;
1831
Wei Yongjun76595022009-03-12 09:49:19 +00001832 if (!asoc->peer.prsctp_capable)
1833 return;
1834
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1836 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001837 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1839 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1840 */
1841 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1842 asoc->adv_peer_ack_point = ctsn;
1843
1844 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1845 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1846 * the chunk next in the out-queue space is marked as "abandoned" as
1847 * shown in the following example:
1848 *
1849 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1850 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001851 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001852 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1853 * normal SACK processing local advancement
1854 * ... ...
1855 * Adv.Ack.Pt-> 102 acked 102 acked
1856 * 103 abandoned 103 abandoned
1857 * 104 abandoned Adv.Ack.P-> 104 abandoned
1858 * 105 105
1859 * 106 acked 106 acked
1860 * ... ...
1861 *
1862 * In this example, the data sender successfully advanced the
1863 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1864 */
1865 list_for_each_safe(lchunk, temp, &q->abandoned) {
1866 chunk = list_entry(lchunk, struct sctp_chunk,
1867 transmitted_list);
1868 tsn = ntohl(chunk->subh.data_hdr->tsn);
1869
1870 /* Remove any chunks in the abandoned queue that are acked by
1871 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001872 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873 if (TSN_lte(tsn, ctsn)) {
1874 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875 sctp_chunk_free(chunk);
1876 } else {
1877 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1878 asoc->adv_peer_ack_point = tsn;
1879 if (chunk->chunk_hdr->flags &
1880 SCTP_DATA_UNORDERED)
1881 continue;
1882 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1883 nskips,
1884 chunk->subh.data_hdr->stream);
1885 ftsn_skip_arr[skip_pos].stream =
1886 chunk->subh.data_hdr->stream;
1887 ftsn_skip_arr[skip_pos].ssn =
1888 chunk->subh.data_hdr->ssn;
1889 if (skip_pos == nskips)
1890 nskips++;
1891 if (nskips == 10)
1892 break;
1893 } else
1894 break;
1895 }
1896 }
1897
1898 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1899 * is greater than the Cumulative TSN ACK carried in the received
1900 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1901 * chunk containing the latest value of the
1902 * "Advanced.Peer.Ack.Point".
1903 *
1904 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1905 * list each stream and sequence number in the forwarded TSN. This
1906 * information will enable the receiver to easily find any
1907 * stranded TSN's waiting on stream reorder queues. Each stream
1908 * SHOULD only be reported once; this means that if multiple
1909 * abandoned messages occur in the same stream then only the
1910 * highest abandoned stream sequence number is reported. If the
1911 * total size of the FORWARD TSN does NOT fit in a single MTU then
1912 * the sender of the FORWARD TSN SHOULD lower the
1913 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1914 * single MTU.
1915 */
1916 if (asoc->adv_peer_ack_point > ctsn)
1917 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001918 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001919
1920 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001921 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00001922 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001923 }
1924}