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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,
66 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -040067 __u32 *highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69static void sctp_mark_missing(struct sctp_outq *q,
70 struct list_head *transmitted_queue,
71 struct sctp_transport *transport,
72 __u32 highest_new_tsn,
73 int count_of_newacks);
74
75static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
76
Adrian Bunkabd0b1982008-07-22 14:20:45 -070077static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout);
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079/* Add data to the front of the queue. */
80static inline void sctp_outq_head_data(struct sctp_outq *q,
81 struct sctp_chunk *ch)
82{
David S. Miller79af02c2005-07-08 21:47:49 -070083 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085}
86
87/* Take data from the front of the queue. */
88static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
89{
David S. Miller79af02c2005-07-08 21:47:49 -070090 struct sctp_chunk *ch = NULL;
91
92 if (!list_empty(&q->out_chunk_list)) {
93 struct list_head *entry = q->out_chunk_list.next;
94
95 ch = list_entry(entry, struct sctp_chunk, list);
96 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 q->out_qlen -= ch->skb->len;
David S. Miller79af02c2005-07-08 21:47:49 -070098 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 return ch;
100}
101/* Add data chunk to the end of the queue. */
102static inline void sctp_outq_tail_data(struct sctp_outq *q,
103 struct sctp_chunk *ch)
104{
David S. Miller79af02c2005-07-08 21:47:49 -0700105 list_add_tail(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 q->out_qlen += ch->skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107}
108
109/*
110 * SFR-CACC algorithm:
111 * D) If count_of_newacks is greater than or equal to 2
112 * and t was not sent to the current primary then the
113 * sender MUST NOT increment missing report count for t.
114 */
115static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
116 struct sctp_transport *transport,
117 int count_of_newacks)
118{
119 if (count_of_newacks >=2 && transport != primary)
120 return 1;
121 return 0;
122}
123
124/*
125 * SFR-CACC algorithm:
126 * F) If count_of_newacks is less than 2, let d be the
127 * destination to which t was sent. If cacc_saw_newack
128 * is 0 for destination d, then the sender MUST NOT
129 * increment missing report count for t.
130 */
131static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
132 int count_of_newacks)
133{
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000134 if (count_of_newacks < 2 &&
135 (transport && !transport->cacc.cacc_saw_newack))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 return 1;
137 return 0;
138}
139
140/*
141 * SFR-CACC algorithm:
142 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
143 * execute steps C, D, F.
144 *
145 * C has been implemented in sctp_outq_sack
146 */
147static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
148 struct sctp_transport *transport,
149 int count_of_newacks)
150{
151 if (!primary->cacc.cycling_changeover) {
152 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
153 return 1;
154 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
155 return 1;
156 return 0;
157 }
158 return 0;
159}
160
161/*
162 * SFR-CACC algorithm:
163 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
164 * than next_tsn_at_change of the current primary, then
165 * the sender MUST NOT increment missing report count
166 * for t.
167 */
168static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
169{
170 if (primary->cacc.cycling_changeover &&
171 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
172 return 1;
173 return 0;
174}
175
176/*
177 * SFR-CACC algorithm:
178 * 3) If the missing report count for TSN t is to be
179 * incremented according to [RFC2960] and
180 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300181 * then the sender MUST further execute steps 3.1 and
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 * 3.2 to determine if the missing report count for
183 * TSN t SHOULD NOT be incremented.
184 *
185 * 3.3) If 3.1 and 3.2 do not dictate that the missing
186 * report count for t should not be incremented, then
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300187 * the sender SHOULD increment missing report count for
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
189 */
190static inline int sctp_cacc_skip(struct sctp_transport *primary,
191 struct sctp_transport *transport,
192 int count_of_newacks,
193 __u32 tsn)
194{
195 if (primary->cacc.changeover_active &&
Joe Perchesf64f9e72009-11-29 16:55:45 -0800196 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) ||
197 sctp_cacc_skip_3_2(primary, tsn)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 return 1;
199 return 0;
200}
201
202/* Initialize an existing sctp_outq. This does the boring stuff.
203 * You still need to define handlers if you really want to DO
204 * something with this structure...
205 */
206void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
207{
208 q->asoc = asoc;
David S. Miller79af02c2005-07-08 21:47:49 -0700209 INIT_LIST_HEAD(&q->out_chunk_list);
210 INIT_LIST_HEAD(&q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 INIT_LIST_HEAD(&q->retransmit);
212 INIT_LIST_HEAD(&q->sacked);
213 INIT_LIST_HEAD(&q->abandoned);
214
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700215 q->fast_rtx = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 q->outstanding_bytes = 0;
217 q->empty = 1;
218 q->cork = 0;
219
220 q->malloced = 0;
221 q->out_qlen = 0;
222}
223
224/* Free the outqueue structure and any related pending chunks.
225 */
226void sctp_outq_teardown(struct sctp_outq *q)
227{
228 struct sctp_transport *transport;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700229 struct list_head *lchunk, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700230 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
232 /* Throw away unacknowledged chunks. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700233 list_for_each_entry(transport, &q->asoc->peer.transport_addr_list,
234 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
236 chunk = list_entry(lchunk, struct sctp_chunk,
237 transmitted_list);
238 /* Mark as part of a failed message. */
239 sctp_chunk_fail(chunk, q->error);
240 sctp_chunk_free(chunk);
241 }
242 }
243
244 /* Throw away chunks that have been gap ACKed. */
245 list_for_each_safe(lchunk, temp, &q->sacked) {
246 list_del_init(lchunk);
247 chunk = list_entry(lchunk, struct sctp_chunk,
248 transmitted_list);
249 sctp_chunk_fail(chunk, q->error);
250 sctp_chunk_free(chunk);
251 }
252
253 /* Throw away any chunks in the retransmit queue. */
254 list_for_each_safe(lchunk, temp, &q->retransmit) {
255 list_del_init(lchunk);
256 chunk = list_entry(lchunk, struct sctp_chunk,
257 transmitted_list);
258 sctp_chunk_fail(chunk, q->error);
259 sctp_chunk_free(chunk);
260 }
261
262 /* Throw away any chunks that are in the abandoned queue. */
263 list_for_each_safe(lchunk, temp, &q->abandoned) {
264 list_del_init(lchunk);
265 chunk = list_entry(lchunk, struct sctp_chunk,
266 transmitted_list);
267 sctp_chunk_fail(chunk, q->error);
268 sctp_chunk_free(chunk);
269 }
270
271 /* Throw away any leftover data chunks. */
272 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
273
274 /* Mark as send failure. */
275 sctp_chunk_fail(chunk, q->error);
276 sctp_chunk_free(chunk);
277 }
278
279 q->error = 0;
280
281 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700282 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
283 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700285 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}
287
288/* Free the outqueue structure and any related pending chunks. */
289void sctp_outq_free(struct sctp_outq *q)
290{
291 /* Throw away leftover chunks. */
292 sctp_outq_teardown(q);
293
294 /* If we were kmalloc()'d, free the memory. */
295 if (q->malloced)
296 kfree(q);
297}
298
299/* Put a new chunk in an sctp_outq. */
300int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
301{
302 int error = 0;
303
304 SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
305 q, chunk, chunk && chunk->chunk_hdr ?
306 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
307 : "Illegal Chunk");
308
309 /* If it is data, queue it up, otherwise, send it
310 * immediately.
311 */
Shan Weiec7b9512010-04-30 22:41:09 -0400312 if (sctp_chunk_is_data(chunk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 /* Is it OK to queue data chunks? */
314 /* From 9. Termination of Association
315 *
316 * When either endpoint performs a shutdown, the
317 * association on each peer will stop accepting new
318 * data from its user and only deliver data in queue
319 * at the time of sending or receiving the SHUTDOWN
320 * chunk.
321 */
322 switch (q->asoc->state) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 case SCTP_STATE_CLOSED:
324 case SCTP_STATE_SHUTDOWN_PENDING:
325 case SCTP_STATE_SHUTDOWN_SENT:
326 case SCTP_STATE_SHUTDOWN_RECEIVED:
327 case SCTP_STATE_SHUTDOWN_ACK_SENT:
328 /* Cannot send after transport endpoint shutdown */
329 error = -ESHUTDOWN;
330 break;
331
332 default:
333 SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
334 q, chunk, chunk && chunk->chunk_hdr ?
335 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
336 : "Illegal Chunk");
337
338 sctp_outq_tail_data(q, chunk);
339 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
340 SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
341 else
342 SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
343 q->empty = 0;
344 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700345 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700347 list_add_tail(&chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
349 }
350
351 if (error < 0)
352 return error;
353
354 if (!q->cork)
355 error = sctp_outq_flush(q, 0);
356
357 return error;
358}
359
360/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
361 * and the abandoned list are in ascending order.
362 */
363static void sctp_insert_list(struct list_head *head, struct list_head *new)
364{
365 struct list_head *pos;
366 struct sctp_chunk *nchunk, *lchunk;
367 __u32 ntsn, ltsn;
368 int done = 0;
369
370 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
371 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
372
373 list_for_each(pos, head) {
374 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
375 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
376 if (TSN_lt(ntsn, ltsn)) {
377 list_add(new, pos->prev);
378 done = 1;
379 break;
380 }
381 }
382 if (!done)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900383 list_add_tail(new, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384}
385
386/* Mark all the eligible packets on a transport for retransmission. */
387void sctp_retransmit_mark(struct sctp_outq *q,
388 struct sctp_transport *transport,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400389 __u8 reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390{
391 struct list_head *lchunk, *ltemp;
392 struct sctp_chunk *chunk;
393
394 /* Walk through the specified transmitted queue. */
395 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
396 chunk = list_entry(lchunk, struct sctp_chunk,
397 transmitted_list);
398
399 /* If the chunk is abandoned, move it to abandoned list. */
400 if (sctp_chunk_abandoned(chunk)) {
401 list_del_init(lchunk);
402 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800403
404 /* If this chunk has not been previousely acked,
405 * stop considering it 'outstanding'. Our peer
406 * will most likely never see it since it will
407 * not be retransmitted
408 */
409 if (!chunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400410 if (chunk->transport)
411 chunk->transport->flight_size -=
412 sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800413 q->outstanding_bytes -= sctp_data_size(chunk);
Thomas Grafa76c0ad2011-12-19 04:11:40 +0000414 q->asoc->peer.rwnd += sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800415 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 continue;
417 }
418
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400419 /* If we are doing retransmission due to a timeout or pmtu
420 * discovery, only the chunks that are not yet acked should
421 * be added to the retransmit queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400423 if ((reason == SCTP_RTXR_FAST_RTX &&
Neil Hormanc226ef92008-07-25 12:44:09 -0400424 (chunk->fast_retransmit == SCTP_NEED_FRTX)) ||
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400425 (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 /* RFC 2960 6.2.1 Processing a Received SACK
427 *
428 * C) Any time a DATA chunk is marked for
429 * retransmission (via either T3-rtx timer expiration
430 * (Section 6.3.3) or via fast retransmit
431 * (Section 7.2.4)), add the data size of those
432 * chunks to the rwnd.
433 */
Thomas Grafa76c0ad2011-12-19 04:11:40 +0000434 q->asoc->peer.rwnd += sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 q->outstanding_bytes -= sctp_data_size(chunk);
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400436 if (chunk->transport)
437 transport->flight_size -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
439 /* sctpimpguide-05 Section 2.8.2
440 * M5) If a T3-rtx timer expires, the
441 * 'TSN.Missing.Report' of all affected TSNs is set
442 * to 0.
443 */
444 chunk->tsn_missing_report = 0;
445
446 /* If a chunk that is being used for RTT measurement
447 * has to be retransmitted, we cannot use this chunk
448 * anymore for RTT measurements. Reset rto_pending so
449 * that a new RTT measurement is started when a new
450 * data chunk is sent.
451 */
452 if (chunk->rtt_in_progress) {
453 chunk->rtt_in_progress = 0;
454 transport->rto_pending = 0;
455 }
456
457 /* Move the chunk to the retransmit queue. The chunks
458 * on the retransmit queue are always kept in order.
459 */
460 list_del_init(lchunk);
461 sctp_insert_list(&q->retransmit, lchunk);
462 }
463 }
464
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400465 SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 "cwnd: %d, ssthresh: %d, flight_size: %d, "
Harvey Harrison0dc47872008-03-05 20:47:47 -0800467 "pba: %d\n", __func__,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400468 transport, reason,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 transport->cwnd, transport->ssthresh,
470 transport->flight_size,
471 transport->partial_bytes_acked);
472
473}
474
475/* Mark all the eligible packets on a transport for retransmission and force
476 * one packet out.
477 */
478void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
479 sctp_retransmit_reason_t reason)
480{
481 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
483 switch(reason) {
484 case SCTP_RTXR_T3_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700485 SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
487 /* Update the retran path if the T3-rtx timer has expired for
488 * the current retran path.
489 */
490 if (transport == transport->asoc->peer.retran_path)
491 sctp_assoc_update_retran_path(transport->asoc);
Neil Horman58fbbed2008-02-29 11:40:56 -0800492 transport->asoc->rtx_data_chunks +=
493 transport->asoc->unack_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 break;
495 case SCTP_RTXR_FAST_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700496 SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700498 q->fast_rtx = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 break;
500 case SCTP_RTXR_PMTUD:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700501 SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 break;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400503 case SCTP_RTXR_T1_RTX:
504 SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS);
Neil Horman58fbbed2008-02-29 11:40:56 -0800505 transport->asoc->init_retries++;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400506 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700507 default:
508 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 }
510
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400511 sctp_retransmit_mark(q, transport, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
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 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700517 if (reason == SCTP_RTXR_T3_RTX)
518 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700520 /* Flush the queues only on timeout, since fast_rtx is only
521 * triggered during sack processing and the queue
522 * will be flushed at the end.
523 */
524 if (reason != SCTP_RTXR_FAST_RTX)
525 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526
527 if (error)
528 q->asoc->base.sk->sk_err = -error;
529}
530
531/*
532 * Transmit DATA chunks on the retransmit queue. Upon return from
533 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
534 * need to be transmitted by the caller.
535 * We assume that pkt->transport has already been set.
536 *
537 * The return value is a normal kernel error return value.
538 */
539static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
540 int rtx_timeout, int *start_timer)
541{
542 struct list_head *lqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 struct sctp_transport *transport = pkt->transport;
544 sctp_xmit_t status;
545 struct sctp_chunk *chunk, *chunk1;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700546 int fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 int error = 0;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700548 int timer = 0;
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700549 int done = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 lqueue = &q->retransmit;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700552 fast_rtx = q->fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700554 /* This loop handles time-out retransmissions, fast retransmissions,
555 * and retransmissions due to opening of whindow.
556 *
557 * RFC 2960 6.3.3 Handle T3-rtx Expiration
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 *
559 * E3) Determine how many of the earliest (i.e., lowest TSN)
560 * outstanding DATA chunks for the address for which the
561 * T3-rtx has expired will fit into a single packet, subject
562 * to the MTU constraint for the path corresponding to the
563 * destination transport address to which the retransmission
564 * is being sent (this may be different from the address for
565 * which the timer expires [see Section 6.4]). Call this value
566 * K. Bundle and retransmit those K DATA chunks in a single
567 * packet to the destination endpoint.
568 *
569 * [Just to be painfully clear, if we are retransmitting
570 * because a timeout just happened, we should send only ONE
571 * packet of retransmitted data.]
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700572 *
573 * For fast retransmissions we also send only ONE packet. However,
574 * if we are just flushing the queue due to open window, we'll
575 * try to send as much as possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700577 list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) {
Wei Yongjun4c6a6f42011-04-19 21:32:28 +0000578 /* If the chunk is abandoned, move it to abandoned list. */
579 if (sctp_chunk_abandoned(chunk)) {
580 list_del_init(&chunk->transmitted_list);
581 sctp_insert_list(&q->abandoned,
582 &chunk->transmitted_list);
583 continue;
584 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
586 /* Make sure that Gap Acked TSNs are not retransmitted. A
587 * simple approach is just to move such TSNs out of the
588 * way and into a 'transmitted' queue and skip to the
589 * next chunk.
590 */
591 if (chunk->tsn_gap_acked) {
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700592 list_del(&chunk->transmitted_list);
593 list_add_tail(&chunk->transmitted_list,
594 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 continue;
596 }
597
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700598 /* If we are doing fast retransmit, ignore non-fast_rtransmit
599 * chunks
600 */
601 if (fast_rtx && !chunk->fast_retransmit)
602 continue;
603
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400604redo:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 /* Attempt to append this chunk to the packet. */
606 status = sctp_packet_append_chunk(pkt, chunk);
607
608 switch (status) {
609 case SCTP_XMIT_PMTU_FULL:
Wei Yongjunbc4f8412010-04-30 22:38:53 -0400610 if (!pkt->has_data && !pkt->has_cookie_echo) {
611 /* If this packet did not contain DATA then
612 * retransmission did not happen, so do it
613 * again. We'll ignore the error here since
614 * control chunks are already freed so there
615 * is nothing we can do.
616 */
617 sctp_packet_transmit(pkt);
618 goto redo;
619 }
620
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700622 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
624 /* If we are retransmitting, we should only
625 * send a single packet.
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000626 * Otherwise, try appending this chunk again.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700628 if (rtx_timeout || fast_rtx)
629 done = 1;
Vlad Yasevichf246a7b2011-04-18 19:13:56 +0000630 else
631 goto redo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700633 /* Bundle next chunk in the next round. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 break;
635
636 case SCTP_XMIT_RWND_FULL:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900637 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700638 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639
640 /* Stop sending DATA as there is no more room
641 * at the receiver.
642 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700643 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 break;
645
646 case SCTP_XMIT_NAGLE_DELAY:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900647 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700648 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649
650 /* Stop sending DATA because of nagle delay. */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700651 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 break;
653
654 default:
655 /* The append was successful, so add this chunk to
656 * the transmitted list.
657 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700658 list_del(&chunk->transmitted_list);
659 list_add_tail(&chunk->transmitted_list,
660 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900662 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 * after it is retransmitted.
664 */
Neil Hormanc226ef92008-07-25 12:44:09 -0400665 if (chunk->fast_retransmit == SCTP_NEED_FRTX)
666 chunk->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 q->empty = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700670 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700672 /* Set the timer if there were no errors */
673 if (!error && !timer)
674 timer = 1;
675
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700676 if (done)
677 break;
678 }
679
680 /* If we are here due to a retransmit timeout or a fast
681 * retransmit and if there are any chunks left in the retransmit
682 * queue that could not fit in the PMTU sized packet, they need
683 * to be marked as ineligible for a subsequent fast retransmit.
684 */
685 if (rtx_timeout || fast_rtx) {
686 list_for_each_entry(chunk1, lqueue, transmitted_list) {
Neil Hormanc226ef92008-07-25 12:44:09 -0400687 if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
688 chunk1->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 }
690 }
691
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700692 *start_timer = timer;
693
694 /* Clear fast retransmit hint */
695 if (fast_rtx)
696 q->fast_rtx = 0;
697
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 return error;
699}
700
701/* Cork the outqueue so queued chunks are really queued. */
702int sctp_outq_uncork(struct sctp_outq *q)
703{
704 int error = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500705 if (q->cork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 q->cork = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500707 error = sctp_outq_flush(q, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 return error;
709}
710
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700711
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712/*
713 * Try to flush an outqueue.
714 *
715 * Description: Send everything in q which we legally can, subject to
716 * congestion limitations.
717 * * Note: This function can be called from multiple contexts so appropriate
718 * locking concerns must be made. Today we use the sock lock to protect
719 * this function.
720 */
Adrian Bunkabd0b1982008-07-22 14:20:45 -0700721static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722{
723 struct sctp_packet *packet;
724 struct sctp_packet singleton;
725 struct sctp_association *asoc = q->asoc;
726 __u16 sport = asoc->base.bind_addr.port;
727 __u16 dport = asoc->peer.port;
728 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 struct sctp_transport *transport = NULL;
730 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700731 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 sctp_xmit_t status;
733 int error = 0;
734 int start_timer = 0;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700735 int one_packet = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 /* These transports have chunks to send. */
738 struct list_head transport_list;
739 struct list_head *ltransport;
740
741 INIT_LIST_HEAD(&transport_list);
742 packet = NULL;
743
744 /*
745 * 6.10 Bundling
746 * ...
747 * When bundling control chunks with DATA chunks, an
748 * endpoint MUST place control chunks first in the outbound
749 * SCTP packet. The transmitter MUST transmit DATA chunks
750 * within a SCTP packet in increasing order of TSN.
751 * ...
752 */
753
David S. Miller79af02c2005-07-08 21:47:49 -0700754 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
Michio Honda8a07eb02011-04-26 20:19:36 +0900755 /* RFC 5061, 5.3
756 * F1) This means that until such time as the ASCONF
757 * containing the add is acknowledged, the sender MUST
758 * NOT use the new IP address as a source for ANY SCTP
759 * packet except on carrying an ASCONF Chunk.
760 */
761 if (asoc->src_out_of_asoc_ok &&
762 chunk->chunk_hdr->type != SCTP_CID_ASCONF)
763 continue;
764
David S. Miller79af02c2005-07-08 21:47:49 -0700765 list_del_init(&chunk->list);
766
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 /* Pick the right transport to use. */
768 new_transport = chunk->transport;
769
770 if (!new_transport) {
Vlad Yasevicha08de642007-12-20 14:11:47 -0800771 /*
772 * If we have a prior transport pointer, see if
773 * the destination address of the chunk
774 * matches the destination address of the
775 * current transport. If not a match, then
776 * try to look up the transport with a given
777 * destination address. We do this because
778 * after processing ASCONFs, we may have new
779 * transports created.
780 */
781 if (transport &&
782 sctp_cmp_addr_exact(&chunk->dest,
783 &transport->ipaddr))
784 new_transport = transport;
785 else
786 new_transport = sctp_assoc_lookup_paddr(asoc,
787 &chunk->dest);
788
789 /* if we still don't have a new transport, then
790 * use the current active path.
791 */
792 if (!new_transport)
793 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700794 } else if ((new_transport->state == SCTP_INACTIVE) ||
Neil Horman5aa93bc2012-07-21 07:56:07 +0000795 (new_transport->state == SCTP_UNCONFIRMED) ||
796 (new_transport->state == SCTP_PF)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700797 /* If the chunk is Heartbeat or Heartbeat Ack,
798 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 * inactive.
800 *
801 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900802 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 * A HEARTBEAT ACK is always sent to the source IP
804 * address of the IP datagram containing the
805 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900806 * ...
Vlad Yasevicha08de642007-12-20 14:11:47 -0800807 *
808 * ASCONF_ACKs also must be sent to the source.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 */
810 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
Vlad Yasevicha08de642007-12-20 14:11:47 -0800811 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
812 chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 new_transport = asoc->peer.active_path;
814 }
815
816 /* Are we switching transports?
817 * Take care of transport locks.
818 */
819 if (new_transport != transport) {
820 transport = new_transport;
821 if (list_empty(&transport->send_ready)) {
822 list_add_tail(&transport->send_ready,
823 &transport_list);
824 }
825 packet = &transport->packet;
826 sctp_packet_config(packet, vtag,
827 asoc->peer.ecn_capable);
828 }
829
830 switch (chunk->chunk_hdr->type) {
831 /*
832 * 6.10 Bundling
833 * ...
834 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
835 * COMPLETE with any other chunks. [Send them immediately.]
836 */
837 case SCTP_CID_INIT:
838 case SCTP_CID_INIT_ACK:
839 case SCTP_CID_SHUTDOWN_COMPLETE:
840 sctp_packet_init(&singleton, transport, sport, dport);
841 sctp_packet_config(&singleton, vtag, 0);
842 sctp_packet_append_chunk(&singleton, chunk);
843 error = sctp_packet_transmit(&singleton);
844 if (error < 0)
845 return error;
846 break;
847
848 case SCTP_CID_ABORT:
Gui Jianfengf4ad85c2008-04-12 18:39:34 -0700849 if (sctp_test_T_bit(chunk)) {
850 packet->vtag = asoc->c.my_vtag;
851 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700852 /* The following chunks are "response" chunks, i.e.
853 * they are generated in response to something we
854 * received. If we are sending these, then we can
855 * send only 1 packet containing these chunks.
856 */
857 case SCTP_CID_HEARTBEAT_ACK:
858 case SCTP_CID_SHUTDOWN_ACK:
859 case SCTP_CID_COOKIE_ACK:
860 case SCTP_CID_COOKIE_ECHO:
861 case SCTP_CID_ERROR:
862 case SCTP_CID_ECN_CWR:
863 case SCTP_CID_ASCONF_ACK:
864 one_packet = 1;
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300865 /* Fall through */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700866
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 case SCTP_CID_SACK:
868 case SCTP_CID_HEARTBEAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 case SCTP_CID_SHUTDOWN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 case SCTP_CID_ECN_ECNE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 case SCTP_CID_ASCONF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 case SCTP_CID_FWD_TSN:
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700873 status = sctp_packet_transmit_chunk(packet, chunk,
874 one_packet);
875 if (status != SCTP_XMIT_OK) {
876 /* put the chunk back */
877 list_add(&chunk->list, &q->control_chunk_list);
Wei Yongjunbd69b982010-04-30 21:42:43 -0400878 } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
879 /* PR-SCTP C5) If a FORWARD TSN is sent, the
880 * sender MUST assure that at least one T3-rtx
881 * timer is running.
882 */
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400883 sctp_transport_reset_timers(transport);
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700884 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885 break;
886
887 default:
888 /* We built a chunk with an illegal type! */
889 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700890 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 }
892
Michio Honda8a07eb02011-04-26 20:19:36 +0900893 if (q->asoc->src_out_of_asoc_ok)
894 goto sctp_flush_out;
895
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 /* Is it OK to send data chunks? */
897 switch (asoc->state) {
898 case SCTP_STATE_COOKIE_ECHOED:
899 /* Only allow bundling when this packet has a COOKIE-ECHO
900 * chunk.
901 */
902 if (!packet || !packet->has_cookie_echo)
903 break;
904
905 /* fallthru */
906 case SCTP_STATE_ESTABLISHED:
907 case SCTP_STATE_SHUTDOWN_PENDING:
908 case SCTP_STATE_SHUTDOWN_RECEIVED:
909 /*
910 * RFC 2960 6.1 Transmission of DATA Chunks
911 *
912 * C) When the time comes for the sender to transmit,
913 * before sending new DATA chunks, the sender MUST
914 * first transmit any outstanding DATA chunks which
915 * are marked for retransmission (limited by the
916 * current cwnd).
917 */
918 if (!list_empty(&q->retransmit)) {
Michio Hondaf207c052011-06-16 10:54:23 +0900919 if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED)
920 goto sctp_flush_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 if (transport == asoc->peer.retran_path)
922 goto retran;
923
924 /* Switch transports & prepare the packet. */
925
926 transport = asoc->peer.retran_path;
927
928 if (list_empty(&transport->send_ready)) {
929 list_add_tail(&transport->send_ready,
930 &transport_list);
931 }
932
933 packet = &transport->packet;
934 sctp_packet_config(packet, vtag,
935 asoc->peer.ecn_capable);
936 retran:
937 error = sctp_outq_flush_rtx(q, packet,
938 rtx_timeout, &start_timer);
939
940 if (start_timer)
Vlad Yasevichd9efc222010-04-30 22:41:09 -0400941 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942
943 /* This can happen on COOKIE-ECHO resend. Only
944 * one chunk can get bundled with a COOKIE-ECHO.
945 */
946 if (packet->has_cookie_echo)
947 goto sctp_flush_out;
948
949 /* Don't send new data if there is still data
950 * waiting to retransmit.
951 */
952 if (!list_empty(&q->retransmit))
953 goto sctp_flush_out;
954 }
955
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500956 /* Apply Max.Burst limitation to the current transport in
957 * case it will be used for new data. We are going to
958 * rest it before we return, but we want to apply the limit
959 * to the currently queued data.
960 */
961 if (transport)
962 sctp_transport_burst_limited(transport);
963
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 /* Finally, transmit new packets. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
966 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
967 * stream identifier.
968 */
969 if (chunk->sinfo.sinfo_stream >=
970 asoc->c.sinit_num_ostreams) {
971
972 /* Mark as failed send. */
973 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
974 sctp_chunk_free(chunk);
975 continue;
976 }
977
978 /* Has this chunk expired? */
979 if (sctp_chunk_abandoned(chunk)) {
980 sctp_chunk_fail(chunk, 0);
981 sctp_chunk_free(chunk);
982 continue;
983 }
984
985 /* If there is a specified transport, use it.
986 * Otherwise, we want to use the active path.
987 */
988 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700989 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700990 ((new_transport->state == SCTP_INACTIVE) ||
Neil Horman5aa93bc2012-07-21 07:56:07 +0000991 (new_transport->state == SCTP_UNCONFIRMED) ||
992 (new_transport->state == SCTP_PF)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 new_transport = asoc->peer.active_path;
Michio Hondaf207c052011-06-16 10:54:23 +0900994 if (new_transport->state == SCTP_UNCONFIRMED)
995 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996
997 /* Change packets if necessary. */
998 if (new_transport != transport) {
999 transport = new_transport;
1000
1001 /* Schedule to have this transport's
1002 * packet flushed.
1003 */
1004 if (list_empty(&transport->send_ready)) {
1005 list_add_tail(&transport->send_ready,
1006 &transport_list);
1007 }
1008
1009 packet = &transport->packet;
1010 sctp_packet_config(packet, vtag,
1011 asoc->peer.ecn_capable);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001012 /* We've switched transports, so apply the
1013 * Burst limit to the new transport.
1014 */
1015 sctp_transport_burst_limited(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 }
1017
1018 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
1019 q, chunk,
1020 chunk && chunk->chunk_hdr ?
1021 sctp_cname(SCTP_ST_CHUNK(
1022 chunk->chunk_hdr->type))
1023 : "Illegal Chunk");
1024
1025 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
1026 "%p skb->users %d.\n",
1027 ntohl(chunk->subh.data_hdr->tsn),
1028 chunk->skb ?chunk->skb->head : NULL,
1029 chunk->skb ?
1030 atomic_read(&chunk->skb->users) : -1);
1031
1032 /* Add the chunk to the packet. */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07001033 status = sctp_packet_transmit_chunk(packet, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034
1035 switch (status) {
1036 case SCTP_XMIT_PMTU_FULL:
1037 case SCTP_XMIT_RWND_FULL:
1038 case SCTP_XMIT_NAGLE_DELAY:
1039 /* We could not append this chunk, so put
1040 * the chunk back on the output queue.
1041 */
1042 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
1043 "not transmit TSN: 0x%x, status: %d\n",
1044 ntohl(chunk->subh.data_hdr->tsn),
1045 status);
1046 sctp_outq_head_data(q, chunk);
1047 goto sctp_flush_out;
1048 break;
1049
1050 case SCTP_XMIT_OK:
Wei Yongjunb93d6472009-11-23 15:53:56 -05001051 /* The sender is in the SHUTDOWN-PENDING state,
1052 * The sender MAY set the I-bit in the DATA
1053 * chunk header.
1054 */
1055 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
1056 chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
1057
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 break;
1059
1060 default:
1061 BUG();
1062 }
1063
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001064 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065 * call below will succeed all the time and add the
1066 * chunk to the transmitted list and restart the
1067 * timers.
1068 * It is possible that the call can fail under OOM
1069 * conditions.
1070 *
1071 * Is this really a problem? Won't this behave
1072 * like a lost TSN?
1073 */
1074 list_add_tail(&chunk->transmitted_list,
1075 &transport->transmitted);
1076
Vlad Yasevichd9efc222010-04-30 22:41:09 -04001077 sctp_transport_reset_timers(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078
1079 q->empty = 0;
1080
1081 /* Only let one DATA chunk get bundled with a
1082 * COOKIE-ECHO chunk.
1083 */
1084 if (packet->has_cookie_echo)
1085 goto sctp_flush_out;
1086 }
1087 break;
1088
1089 default:
1090 /* Do nothing. */
1091 break;
1092 }
1093
1094sctp_flush_out:
1095
1096 /* Before returning, examine all the transports touched in
1097 * this call. Right now, we bluntly force clear all the
1098 * transports. Things might change after we implement Nagle.
1099 * But such an examination is still required.
1100 *
1101 * --xguo
1102 */
1103 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
1104 struct sctp_transport *t = list_entry(ltransport,
1105 struct sctp_transport,
1106 send_ready);
1107 packet = &t->packet;
1108 if (!sctp_packet_empty(packet))
1109 error = sctp_packet_transmit(packet);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001110
1111 /* Clear the burst limited state, if any */
1112 sctp_transport_burst_reset(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 }
1114
1115 return error;
1116}
1117
1118/* Update unack_data based on the incoming SACK chunk */
1119static void sctp_sack_update_unack_data(struct sctp_association *assoc,
1120 struct sctp_sackhdr *sack)
1121{
1122 sctp_sack_variable_t *frags;
1123 __u16 unack_data;
1124 int i;
1125
1126 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
1127
1128 frags = sack->variable;
1129 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1130 unack_data -= ((ntohs(frags[i].gab.end) -
1131 ntohs(frags[i].gab.start) + 1));
1132 }
1133
1134 assoc->unack_data = unack_data;
1135}
1136
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137/* This is where we REALLY process a SACK.
1138 *
1139 * Process the SACK against the outqueue. Mostly, this just frees
1140 * things off the transmitted queue.
1141 */
1142int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
1143{
1144 struct sctp_association *asoc = q->asoc;
1145 struct sctp_transport *transport;
1146 struct sctp_chunk *tchunk = NULL;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001147 struct list_head *lchunk, *transport_list, *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148 sctp_sack_variable_t *frags = sack->variable;
1149 __u32 sack_ctsn, ctsn, tsn;
1150 __u32 highest_tsn, highest_new_tsn;
1151 __u32 sack_a_rwnd;
Eric Dumazet95c96172012-04-15 05:58:06 +00001152 unsigned int outstanding;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 struct sctp_transport *primary = asoc->peer.primary_path;
1154 int count_of_newacks = 0;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001155 int gap_ack_blocks;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001156 u8 accum_moved = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157
1158 /* Grab the association's destination address list. */
1159 transport_list = &asoc->peer.transport_addr_list;
1160
1161 sack_ctsn = ntohl(sack->cum_tsn_ack);
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001162 gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163 /*
1164 * SFR-CACC algorithm:
1165 * On receipt of a SACK the sender SHOULD execute the
1166 * following statements.
1167 *
1168 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1169 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1170 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1171 * all destinations.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1173 * is set the receiver of the SACK MUST take the following actions:
1174 *
1175 * A) Initialize the cacc_saw_newack to 0 for all destination
1176 * addresses.
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001177 *
1178 * Only bother if changeover_active is set. Otherwise, this is
1179 * totally suboptimal to do on every SACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180 */
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001181 if (primary->cacc.changeover_active) {
1182 u8 clear_cycling = 0;
1183
1184 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1185 primary->cacc.changeover_active = 0;
1186 clear_cycling = 1;
1187 }
1188
1189 if (clear_cycling || gap_ack_blocks) {
1190 list_for_each_entry(transport, transport_list,
1191 transports) {
1192 if (clear_cycling)
1193 transport->cacc.cycling_changeover = 0;
1194 if (gap_ack_blocks)
1195 transport->cacc.cacc_saw_newack = 0;
1196 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 }
1198 }
1199
1200 /* Get the highest TSN in the sack. */
1201 highest_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001202 if (gap_ack_blocks)
1203 highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001205 if (TSN_lt(asoc->highest_sacked, highest_tsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 asoc->highest_sacked = highest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001208 highest_new_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001209
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 /* Run through the retransmit queue. Credit bytes received
1211 * and free those chunks that we can.
1212 */
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001213 sctp_check_transmitted(q, &q->retransmit, NULL, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214
1215 /* Run through the transmitted queue.
1216 * Credit bytes received and free those chunks which we can.
1217 *
1218 * This is a MASSIVE candidate for optimization.
1219 */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001220 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 sctp_check_transmitted(q, &transport->transmitted,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001222 transport, sack, &highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 /*
1224 * SFR-CACC algorithm:
1225 * C) Let count_of_newacks be the number of
1226 * destinations for which cacc_saw_newack is set.
1227 */
1228 if (transport->cacc.cacc_saw_newack)
1229 count_of_newacks ++;
1230 }
1231
Vlad Yasevichea862c82010-04-30 22:41:10 -04001232 /* Move the Cumulative TSN Ack Point if appropriate. */
1233 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) {
1234 asoc->ctsn_ack_point = sack_ctsn;
1235 accum_moved = 1;
1236 }
1237
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001238 if (gap_ack_blocks) {
Vlad Yasevichea862c82010-04-30 22:41:10 -04001239
1240 if (asoc->fast_recovery && accum_moved)
1241 highest_new_tsn = highest_tsn;
1242
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001243 list_for_each_entry(transport, transport_list, transports)
1244 sctp_mark_missing(q, &transport->transmitted, transport,
1245 highest_new_tsn, count_of_newacks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 }
1247
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248 /* Update unack_data field in the assoc. */
1249 sctp_sack_update_unack_data(asoc, sack);
1250
1251 ctsn = asoc->ctsn_ack_point;
1252
1253 /* Throw away stuff rotting on the sack queue. */
1254 list_for_each_safe(lchunk, temp, &q->sacked) {
1255 tchunk = list_entry(lchunk, struct sctp_chunk,
1256 transmitted_list);
1257 tsn = ntohl(tchunk->subh.data_hdr->tsn);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001258 if (TSN_lte(tsn, ctsn)) {
1259 list_del_init(&tchunk->transmitted_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 sctp_chunk_free(tchunk);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001261 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 }
1263
1264 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1265 * number of bytes still outstanding after processing the
1266 * Cumulative TSN Ack and the Gap Ack Blocks.
1267 */
1268
1269 sack_a_rwnd = ntohl(sack->a_rwnd);
1270 outstanding = q->outstanding_bytes;
1271
1272 if (outstanding < sack_a_rwnd)
1273 sack_a_rwnd -= outstanding;
1274 else
1275 sack_a_rwnd = 0;
1276
1277 asoc->peer.rwnd = sack_a_rwnd;
1278
1279 sctp_generate_fwdtsn(q, sack_ctsn);
1280
1281 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001282 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1284 "%p is 0x%x. Adv peer ack point: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001285 __func__, asoc, ctsn, asoc->adv_peer_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286
1287 /* See if all chunks are acked.
1288 * Make sure the empty queue handler will get run later.
1289 */
David S. Miller79af02c2005-07-08 21:47:49 -07001290 q->empty = (list_empty(&q->out_chunk_list) &&
David S. Miller79af02c2005-07-08 21:47:49 -07001291 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 if (!q->empty)
1293 goto finish;
1294
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001295 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 q->empty = q->empty && list_empty(&transport->transmitted);
1297 if (!q->empty)
1298 goto finish;
1299 }
1300
1301 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1302finish:
1303 return q->empty;
1304}
1305
1306/* Is the outqueue empty? */
1307int sctp_outq_is_empty(const struct sctp_outq *q)
1308{
1309 return q->empty;
1310}
1311
1312/********************************************************************
1313 * 2nd Level Abstractions
1314 ********************************************************************/
1315
1316/* Go through a transport's transmitted list or the association's retransmit
1317 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1318 * The retransmit list will not have an associated transport.
1319 *
1320 * I added coherent debug information output. --xguo
1321 *
1322 * Instead of printing 'sacked' or 'kept' for each TSN on the
1323 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1324 * KEPT TSN6-TSN7, etc.
1325 */
1326static void sctp_check_transmitted(struct sctp_outq *q,
1327 struct list_head *transmitted_queue,
1328 struct sctp_transport *transport,
1329 struct sctp_sackhdr *sack,
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001330 __u32 *highest_new_tsn_in_sack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331{
1332 struct list_head *lchunk;
1333 struct sctp_chunk *tchunk;
1334 struct list_head tlist;
1335 __u32 tsn;
1336 __u32 sack_ctsn;
1337 __u32 rtt;
1338 __u8 restart_timer = 0;
1339 int bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001340 int migrate_bytes = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341
1342 /* These state variables are for coherent debug output. --xguo */
1343
1344#if SCTP_DEBUG
1345 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1346 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1347 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1348 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1349
1350 /* 0 : The last TSN was ACKed.
1351 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1352 * -1: We need to initialize.
1353 */
1354 int dbg_prt_state = -1;
1355#endif /* SCTP_DEBUG */
1356
1357 sack_ctsn = ntohl(sack->cum_tsn_ack);
1358
1359 INIT_LIST_HEAD(&tlist);
1360
1361 /* The while loop will skip empty transmitted queues. */
1362 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1363 tchunk = list_entry(lchunk, struct sctp_chunk,
1364 transmitted_list);
1365
1366 if (sctp_chunk_abandoned(tchunk)) {
1367 /* Move the chunk to abandoned list. */
1368 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001369
1370 /* If this chunk has not been acked, stop
1371 * considering it as 'outstanding'.
1372 */
1373 if (!tchunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001374 if (tchunk->transport)
1375 tchunk->transport->flight_size -=
1376 sctp_data_size(tchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001377 q->outstanding_bytes -= sctp_data_size(tchunk);
1378 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379 continue;
1380 }
1381
1382 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1383 if (sctp_acked(sack, tsn)) {
1384 /* If this queue is the retransmit queue, the
1385 * retransmit timer has already reclaimed
1386 * the outstanding bytes for this chunk, so only
1387 * count bytes associated with a transport.
1388 */
1389 if (transport) {
1390 /* If this chunk is being used for RTT
1391 * measurement, calculate the RTT and update
1392 * the RTO using this value.
1393 *
1394 * 6.3.1 C5) Karn's algorithm: RTT measurements
1395 * MUST NOT be made using packets that were
1396 * retransmitted (and thus for which it is
1397 * ambiguous whether the reply was for the
1398 * first instance of the packet or a later
1399 * instance).
1400 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001401 if (!tchunk->tsn_gap_acked &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001403 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 rtt = jiffies - tchunk->sent_at;
1405 sctp_transport_update_rto(transport,
1406 rtt);
1407 }
1408 }
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001409
1410 /* If the chunk hasn't been marked as ACKED,
1411 * mark it and account bytes_acked if the
1412 * chunk had a valid transport (it will not
1413 * have a transport if ASCONF had deleted it
1414 * while DATA was outstanding).
1415 */
1416 if (!tchunk->tsn_gap_acked) {
1417 tchunk->tsn_gap_acked = 1;
Vlad Yasevichbfa0d982010-04-30 22:41:10 -04001418 *highest_new_tsn_in_sack = tsn;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001419 bytes_acked += sctp_data_size(tchunk);
1420 if (!tchunk->transport)
1421 migrate_bytes += sctp_data_size(tchunk);
1422 }
1423
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001424 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425 /* RFC 2960 6.3.2 Retransmission Timer Rules
1426 *
1427 * R3) Whenever a SACK is received
1428 * that acknowledges the DATA chunk
1429 * with the earliest outstanding TSN
1430 * for that address, restart T3-rtx
1431 * timer for that address with its
1432 * current RTO.
1433 */
1434 restart_timer = 1;
1435
1436 if (!tchunk->tsn_gap_acked) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001437 /*
1438 * SFR-CACC algorithm:
1439 * 2) If the SACK contains gap acks
1440 * and the flag CHANGEOVER_ACTIVE is
1441 * set the receiver of the SACK MUST
1442 * take the following action:
1443 *
1444 * B) For each TSN t being acked that
1445 * has not been acked in any SACK so
1446 * far, set cacc_saw_newack to 1 for
1447 * the destination that the TSN was
1448 * sent to.
1449 */
1450 if (transport &&
1451 sack->num_gap_ack_blocks &&
1452 q->asoc->peer.primary_path->cacc.
1453 changeover_active)
1454 transport->cacc.cacc_saw_newack
1455 = 1;
1456 }
1457
1458 list_add_tail(&tchunk->transmitted_list,
1459 &q->sacked);
1460 } else {
1461 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1462 * M2) Each time a SACK arrives reporting
1463 * 'Stray DATA chunk(s)' record the highest TSN
1464 * reported as newly acknowledged, call this
1465 * value 'HighestTSNinSack'. A newly
1466 * acknowledged DATA chunk is one not
1467 * previously acknowledged in a SACK.
1468 *
1469 * When the SCTP sender of data receives a SACK
1470 * chunk that acknowledges, for the first time,
1471 * the receipt of a DATA chunk, all the still
1472 * unacknowledged DATA chunks whose TSN is
1473 * older than that newly acknowledged DATA
1474 * chunk, are qualified as 'Stray DATA chunks'.
1475 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476 list_add_tail(lchunk, &tlist);
1477 }
1478
1479#if SCTP_DEBUG
1480 switch (dbg_prt_state) {
1481 case 0: /* last TSN was ACKed */
1482 if (dbg_last_ack_tsn + 1 == tsn) {
1483 /* This TSN belongs to the
1484 * current ACK range.
1485 */
1486 break;
1487 }
1488
1489 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1490 /* Display the end of the
1491 * current range.
1492 */
Joe Perches145ce502010-08-24 13:21:08 +00001493 SCTP_DEBUG_PRINTK_CONT("-%08x",
1494 dbg_last_ack_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495 }
1496
1497 /* Start a new range. */
Joe Perches145ce502010-08-24 13:21:08 +00001498 SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 dbg_ack_tsn = tsn;
1500 break;
1501
1502 case 1: /* The last TSN was NOT ACKed. */
1503 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1504 /* Display the end of current range. */
Joe Perches145ce502010-08-24 13:21:08 +00001505 SCTP_DEBUG_PRINTK_CONT("-%08x",
1506 dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507 }
1508
Joe Perches145ce502010-08-24 13:21:08 +00001509 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510
1511 /* FALL THROUGH... */
1512 default:
1513 /* This is the first-ever TSN we examined. */
1514 /* Start a new range of ACK-ed TSNs. */
1515 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1516 dbg_prt_state = 0;
1517 dbg_ack_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001518 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001519
1520 dbg_last_ack_tsn = tsn;
1521#endif /* SCTP_DEBUG */
1522
1523 } else {
1524 if (tchunk->tsn_gap_acked) {
1525 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1526 "data TSN: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001527 __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 tsn);
1529 tchunk->tsn_gap_acked = 0;
1530
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001531 if (tchunk->transport)
1532 bytes_acked -= sctp_data_size(tchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533
1534 /* RFC 2960 6.3.2 Retransmission Timer Rules
1535 *
1536 * R4) Whenever a SACK is received missing a
1537 * TSN that was previously acknowledged via a
1538 * Gap Ack Block, start T3-rtx for the
1539 * destination address to which the DATA
1540 * chunk was originally
1541 * transmitted if it is not already running.
1542 */
1543 restart_timer = 1;
1544 }
1545
1546 list_add_tail(lchunk, &tlist);
1547
1548#if SCTP_DEBUG
1549 /* See the above comments on ACK-ed TSNs. */
1550 switch (dbg_prt_state) {
1551 case 1:
1552 if (dbg_last_kept_tsn + 1 == tsn)
1553 break;
1554
1555 if (dbg_last_kept_tsn != dbg_kept_tsn)
Joe Perches145ce502010-08-24 13:21:08 +00001556 SCTP_DEBUG_PRINTK_CONT("-%08x",
1557 dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558
Joe Perches145ce502010-08-24 13:21:08 +00001559 SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560 dbg_kept_tsn = tsn;
1561 break;
1562
1563 case 0:
1564 if (dbg_last_ack_tsn != dbg_ack_tsn)
Joe Perches145ce502010-08-24 13:21:08 +00001565 SCTP_DEBUG_PRINTK_CONT("-%08x",
1566 dbg_last_ack_tsn);
1567 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568
1569 /* FALL THROUGH... */
1570 default:
1571 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1572 dbg_prt_state = 1;
1573 dbg_kept_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001574 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001575
1576 dbg_last_kept_tsn = tsn;
1577#endif /* SCTP_DEBUG */
1578 }
1579 }
1580
1581#if SCTP_DEBUG
1582 /* Finish off the last range, displaying its ending TSN. */
1583 switch (dbg_prt_state) {
1584 case 0:
1585 if (dbg_last_ack_tsn != dbg_ack_tsn) {
Joe Perches145ce502010-08-24 13:21:08 +00001586 SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_ack_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001587 } else {
Joe Perches145ce502010-08-24 13:21:08 +00001588 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589 }
1590 break;
1591
1592 case 1:
1593 if (dbg_last_kept_tsn != dbg_kept_tsn) {
Joe Perches145ce502010-08-24 13:21:08 +00001594 SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_kept_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 } else {
Joe Perches145ce502010-08-24 13:21:08 +00001596 SCTP_DEBUG_PRINTK_CONT("\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 }
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001598 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599#endif /* SCTP_DEBUG */
1600 if (transport) {
1601 if (bytes_acked) {
Thomas Graff8d96052011-07-07 00:28:35 +00001602 struct sctp_association *asoc = transport->asoc;
1603
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001604 /* We may have counted DATA that was migrated
1605 * to this transport due to DEL-IP operation.
1606 * Subtract those bytes, since the were never
1607 * send on this transport and shouldn't be
1608 * credited to this transport.
1609 */
1610 bytes_acked -= migrate_bytes;
1611
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 /* 8.2. When an outstanding TSN is acknowledged,
1613 * the endpoint shall clear the error counter of
1614 * the destination transport address to which the
1615 * DATA chunk was last sent.
1616 * The association's overall error counter is
1617 * also cleared.
1618 */
1619 transport->error_count = 0;
1620 transport->asoc->overall_error_count = 0;
1621
Thomas Graff8d96052011-07-07 00:28:35 +00001622 /*
1623 * While in SHUTDOWN PENDING, we may have started
1624 * the T5 shutdown guard timer after reaching the
1625 * retransmission limit. Stop that timer as soon
1626 * as the receiver acknowledged any data.
1627 */
1628 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING &&
1629 del_timer(&asoc->timers
1630 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]))
1631 sctp_association_put(asoc);
1632
Linus Torvalds1da177e2005-04-16 15:20:36 -07001633 /* Mark the destination transport address as
1634 * active if it is not so marked.
1635 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001636 if ((transport->state == SCTP_INACTIVE) ||
1637 (transport->state == SCTP_UNCONFIRMED)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001638 sctp_assoc_control_transport(
1639 transport->asoc,
1640 transport,
1641 SCTP_TRANSPORT_UP,
1642 SCTP_RECEIVED_SACK);
1643 }
1644
1645 sctp_transport_raise_cwnd(transport, sack_ctsn,
1646 bytes_acked);
1647
1648 transport->flight_size -= bytes_acked;
Gui Jianfeng8b73a072008-04-17 14:22:18 -07001649 if (transport->flight_size == 0)
1650 transport->partial_bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001651 q->outstanding_bytes -= bytes_acked + migrate_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 } else {
1653 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1654 * When a sender is doing zero window probing, it
1655 * should not timeout the association if it continues
1656 * to receive new packets from the receiver. The
1657 * reason is that the receiver MAY keep its window
1658 * closed for an indefinite time.
1659 * A sender is doing zero window probing when the
1660 * receiver's advertised window is zero, and there is
1661 * only one data chunk in flight to the receiver.
Thomas Graff8d96052011-07-07 00:28:35 +00001662 *
1663 * Allow the association to timeout while in SHUTDOWN
1664 * PENDING or SHUTDOWN RECEIVED in case the receiver
1665 * stays in zero window mode forever.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666 */
1667 if (!q->asoc->peer.rwnd &&
1668 !list_empty(&tlist) &&
Thomas Graff8d96052011-07-07 00:28:35 +00001669 (sack_ctsn+2 == q->asoc->next_tsn) &&
1670 q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1672 "window probe: %u\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001673 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674 q->asoc->overall_error_count = 0;
1675 transport->error_count = 0;
1676 }
1677 }
1678
1679 /* RFC 2960 6.3.2 Retransmission Timer Rules
1680 *
1681 * R2) Whenever all outstanding data sent to an address have
1682 * been acknowledged, turn off the T3-rtx timer of that
1683 * address.
1684 */
1685 if (!transport->flight_size) {
1686 if (timer_pending(&transport->T3_rtx_timer) &&
1687 del_timer(&transport->T3_rtx_timer)) {
1688 sctp_transport_put(transport);
1689 }
1690 } else if (restart_timer) {
1691 if (!mod_timer(&transport->T3_rtx_timer,
1692 jiffies + transport->rto))
1693 sctp_transport_hold(transport);
1694 }
1695 }
1696
1697 list_splice(&tlist, transmitted_queue);
1698}
1699
1700/* Mark chunks as missing and consequently may get retransmitted. */
1701static void sctp_mark_missing(struct sctp_outq *q,
1702 struct list_head *transmitted_queue,
1703 struct sctp_transport *transport,
1704 __u32 highest_new_tsn_in_sack,
1705 int count_of_newacks)
1706{
1707 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708 __u32 tsn;
1709 char do_fast_retransmit = 0;
Vlad Yasevichea862c82010-04-30 22:41:10 -04001710 struct sctp_association *asoc = q->asoc;
1711 struct sctp_transport *primary = asoc->peer.primary_path;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001713 list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715 tsn = ntohl(chunk->subh.data_hdr->tsn);
1716
1717 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1718 * 'Unacknowledged TSN's', if the TSN number of an
1719 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1720 * value, increment the 'TSN.Missing.Report' count on that
1721 * chunk if it has NOT been fast retransmitted or marked for
1722 * fast retransmit already.
1723 */
Neil Hormanc226ef92008-07-25 12:44:09 -04001724 if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 !chunk->tsn_gap_acked &&
1726 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1727
1728 /* SFR-CACC may require us to skip marking
1729 * this chunk as missing.
1730 */
Vlad Yasevichf246a7b2011-04-18 19:13:56 +00001731 if (!transport || !sctp_cacc_skip(primary,
1732 chunk->transport,
1733 count_of_newacks, tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001734 chunk->tsn_missing_report++;
1735
1736 SCTP_DEBUG_PRINTK(
1737 "%s: TSN 0x%x missing counter: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001738 __func__, tsn,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001739 chunk->tsn_missing_report);
1740 }
1741 }
1742 /*
1743 * M4) If any DATA chunk is found to have a
1744 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001745 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001746 * retransmission and start the fast retransmit procedure.
1747 */
1748
Vlad Yasevich27852c22006-02-02 16:57:31 -08001749 if (chunk->tsn_missing_report >= 3) {
Neil Hormanc226ef92008-07-25 12:44:09 -04001750 chunk->fast_retransmit = SCTP_NEED_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001751 do_fast_retransmit = 1;
1752 }
1753 }
1754
1755 if (transport) {
1756 if (do_fast_retransmit)
1757 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1758
1759 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1760 "ssthresh: %d, flight_size: %d, pba: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001761 __func__, transport, transport->cwnd,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001762 transport->ssthresh, transport->flight_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001763 transport->partial_bytes_acked);
1764 }
1765}
1766
1767/* Is the given TSN acked by this packet? */
1768static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1769{
1770 int i;
1771 sctp_sack_variable_t *frags;
1772 __u16 gap;
1773 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1774
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001775 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001776 goto pass;
1777
1778 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1779 *
1780 * Gap Ack Blocks:
1781 * These fields contain the Gap Ack Blocks. They are repeated
1782 * for each Gap Ack Block up to the number of Gap Ack Blocks
1783 * defined in the Number of Gap Ack Blocks field. All DATA
1784 * chunks with TSNs greater than or equal to (Cumulative TSN
1785 * Ack + Gap Ack Block Start) and less than or equal to
1786 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1787 * Block are assumed to have been received correctly.
1788 */
1789
1790 frags = sack->variable;
1791 gap = tsn - ctsn;
1792 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1793 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1794 TSN_lte(gap, ntohs(frags[i].gab.end)))
1795 goto pass;
1796 }
1797
1798 return 0;
1799pass:
1800 return 1;
1801}
1802
1803static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001804 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001805{
1806 int i;
1807
1808 for (i = 0; i < nskips; i++) {
1809 if (skiplist[i].stream == stream)
1810 return i;
1811 }
1812 return i;
1813}
1814
1815/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1816static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1817{
1818 struct sctp_association *asoc = q->asoc;
1819 struct sctp_chunk *ftsn_chunk = NULL;
1820 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1821 int nskips = 0;
1822 int skip_pos = 0;
1823 __u32 tsn;
1824 struct sctp_chunk *chunk;
1825 struct list_head *lchunk, *temp;
1826
Wei Yongjun76595022009-03-12 09:49:19 +00001827 if (!asoc->peer.prsctp_capable)
1828 return;
1829
Linus Torvalds1da177e2005-04-16 15:20:36 -07001830 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1831 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001832 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001833 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1834 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1835 */
1836 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1837 asoc->adv_peer_ack_point = ctsn;
1838
1839 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1840 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1841 * the chunk next in the out-queue space is marked as "abandoned" as
1842 * shown in the following example:
1843 *
1844 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1845 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001846 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001847 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1848 * normal SACK processing local advancement
1849 * ... ...
1850 * Adv.Ack.Pt-> 102 acked 102 acked
1851 * 103 abandoned 103 abandoned
1852 * 104 abandoned Adv.Ack.P-> 104 abandoned
1853 * 105 105
1854 * 106 acked 106 acked
1855 * ... ...
1856 *
1857 * In this example, the data sender successfully advanced the
1858 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1859 */
1860 list_for_each_safe(lchunk, temp, &q->abandoned) {
1861 chunk = list_entry(lchunk, struct sctp_chunk,
1862 transmitted_list);
1863 tsn = ntohl(chunk->subh.data_hdr->tsn);
1864
1865 /* Remove any chunks in the abandoned queue that are acked by
1866 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001867 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868 if (TSN_lte(tsn, ctsn)) {
1869 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870 sctp_chunk_free(chunk);
1871 } else {
1872 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1873 asoc->adv_peer_ack_point = tsn;
1874 if (chunk->chunk_hdr->flags &
1875 SCTP_DATA_UNORDERED)
1876 continue;
1877 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1878 nskips,
1879 chunk->subh.data_hdr->stream);
1880 ftsn_skip_arr[skip_pos].stream =
1881 chunk->subh.data_hdr->stream;
1882 ftsn_skip_arr[skip_pos].ssn =
1883 chunk->subh.data_hdr->ssn;
1884 if (skip_pos == nskips)
1885 nskips++;
1886 if (nskips == 10)
1887 break;
1888 } else
1889 break;
1890 }
1891 }
1892
1893 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1894 * is greater than the Cumulative TSN ACK carried in the received
1895 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1896 * chunk containing the latest value of the
1897 * "Advanced.Peer.Ack.Point".
1898 *
1899 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1900 * list each stream and sequence number in the forwarded TSN. This
1901 * information will enable the receiver to easily find any
1902 * stranded TSN's waiting on stream reorder queues. Each stream
1903 * SHOULD only be reported once; this means that if multiple
1904 * abandoned messages occur in the same stream then only the
1905 * highest abandoned stream sequence number is reported. If the
1906 * total size of the FORWARD TSN does NOT fit in a single MTU then
1907 * the sender of the FORWARD TSN SHOULD lower the
1908 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1909 * single MTU.
1910 */
1911 if (asoc->adv_peer_ack_point > ctsn)
1912 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001913 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914
1915 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001916 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001917 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1918 }
1919}