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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
49#include <linux/types.h>
50#include <linux/list.h> /* For struct list_head */
51#include <linux/socket.h>
52#include <linux/ip.h>
53#include <net/sock.h> /* For skb_set_owner_w */
54
55#include <net/sctp/sctp.h>
56#include <net/sctp/sm.h>
57
58/* Declare internal functions here. */
59static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn);
60static void sctp_check_transmitted(struct sctp_outq *q,
61 struct list_head *transmitted_queue,
62 struct sctp_transport *transport,
63 struct sctp_sackhdr *sack,
64 __u32 highest_new_tsn);
65
66static void sctp_mark_missing(struct sctp_outq *q,
67 struct list_head *transmitted_queue,
68 struct sctp_transport *transport,
69 __u32 highest_new_tsn,
70 int count_of_newacks);
71
72static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
73
Adrian Bunkabd0b1982008-07-22 14:20:45 -070074static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout);
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076/* Add data to the front of the queue. */
77static inline void sctp_outq_head_data(struct sctp_outq *q,
78 struct sctp_chunk *ch)
79{
David S. Miller79af02c2005-07-08 21:47:49 -070080 list_add(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 q->out_qlen += ch->skb->len;
82 return;
83}
84
85/* Take data from the front of the queue. */
86static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q)
87{
David S. Miller79af02c2005-07-08 21:47:49 -070088 struct sctp_chunk *ch = NULL;
89
90 if (!list_empty(&q->out_chunk_list)) {
91 struct list_head *entry = q->out_chunk_list.next;
92
93 ch = list_entry(entry, struct sctp_chunk, list);
94 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 q->out_qlen -= ch->skb->len;
David S. Miller79af02c2005-07-08 21:47:49 -070096 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 return ch;
98}
99/* Add data chunk to the end of the queue. */
100static inline void sctp_outq_tail_data(struct sctp_outq *q,
101 struct sctp_chunk *ch)
102{
David S. Miller79af02c2005-07-08 21:47:49 -0700103 list_add_tail(&ch->list, &q->out_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 q->out_qlen += ch->skb->len;
105 return;
106}
107
108/*
109 * SFR-CACC algorithm:
110 * D) If count_of_newacks is greater than or equal to 2
111 * and t was not sent to the current primary then the
112 * sender MUST NOT increment missing report count for t.
113 */
114static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary,
115 struct sctp_transport *transport,
116 int count_of_newacks)
117{
118 if (count_of_newacks >=2 && transport != primary)
119 return 1;
120 return 0;
121}
122
123/*
124 * SFR-CACC algorithm:
125 * F) If count_of_newacks is less than 2, let d be the
126 * destination to which t was sent. If cacc_saw_newack
127 * is 0 for destination d, then the sender MUST NOT
128 * increment missing report count for t.
129 */
130static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport,
131 int count_of_newacks)
132{
133 if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack)
134 return 1;
135 return 0;
136}
137
138/*
139 * SFR-CACC algorithm:
140 * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD
141 * execute steps C, D, F.
142 *
143 * C has been implemented in sctp_outq_sack
144 */
145static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary,
146 struct sctp_transport *transport,
147 int count_of_newacks)
148{
149 if (!primary->cacc.cycling_changeover) {
150 if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks))
151 return 1;
152 if (sctp_cacc_skip_3_1_f(transport, count_of_newacks))
153 return 1;
154 return 0;
155 }
156 return 0;
157}
158
159/*
160 * SFR-CACC algorithm:
161 * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less
162 * than next_tsn_at_change of the current primary, then
163 * the sender MUST NOT increment missing report count
164 * for t.
165 */
166static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn)
167{
168 if (primary->cacc.cycling_changeover &&
169 TSN_lt(tsn, primary->cacc.next_tsn_at_change))
170 return 1;
171 return 0;
172}
173
174/*
175 * SFR-CACC algorithm:
176 * 3) If the missing report count for TSN t is to be
177 * incremented according to [RFC2960] and
178 * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set,
179 * then the sender MUST futher execute steps 3.1 and
180 * 3.2 to determine if the missing report count for
181 * TSN t SHOULD NOT be incremented.
182 *
183 * 3.3) If 3.1 and 3.2 do not dictate that the missing
184 * report count for t should not be incremented, then
185 * the sender SOULD increment missing report count for
186 * t (according to [RFC2960] and [SCTP_STEWART_2002]).
187 */
188static inline int sctp_cacc_skip(struct sctp_transport *primary,
189 struct sctp_transport *transport,
190 int count_of_newacks,
191 __u32 tsn)
192{
193 if (primary->cacc.changeover_active &&
Joe Perchesf64f9e72009-11-29 16:55:45 -0800194 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) ||
195 sctp_cacc_skip_3_2(primary, tsn)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 return 1;
197 return 0;
198}
199
200/* Initialize an existing sctp_outq. This does the boring stuff.
201 * You still need to define handlers if you really want to DO
202 * something with this structure...
203 */
204void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q)
205{
206 q->asoc = asoc;
David S. Miller79af02c2005-07-08 21:47:49 -0700207 INIT_LIST_HEAD(&q->out_chunk_list);
208 INIT_LIST_HEAD(&q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 INIT_LIST_HEAD(&q->retransmit);
210 INIT_LIST_HEAD(&q->sacked);
211 INIT_LIST_HEAD(&q->abandoned);
212
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700213 q->fast_rtx = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 q->outstanding_bytes = 0;
215 q->empty = 1;
216 q->cork = 0;
217
218 q->malloced = 0;
219 q->out_qlen = 0;
220}
221
222/* Free the outqueue structure and any related pending chunks.
223 */
224void sctp_outq_teardown(struct sctp_outq *q)
225{
226 struct sctp_transport *transport;
Robert P. J. Day9dbc15f02008-04-12 18:54:24 -0700227 struct list_head *lchunk, *temp;
David S. Miller79af02c2005-07-08 21:47:49 -0700228 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 /* Throw away unacknowledged chunks. */
Robert P. J. Day9dbc15f02008-04-12 18:54:24 -0700231 list_for_each_entry(transport, &q->asoc->peer.transport_addr_list,
232 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) {
234 chunk = list_entry(lchunk, struct sctp_chunk,
235 transmitted_list);
236 /* Mark as part of a failed message. */
237 sctp_chunk_fail(chunk, q->error);
238 sctp_chunk_free(chunk);
239 }
240 }
241
242 /* Throw away chunks that have been gap ACKed. */
243 list_for_each_safe(lchunk, temp, &q->sacked) {
244 list_del_init(lchunk);
245 chunk = list_entry(lchunk, struct sctp_chunk,
246 transmitted_list);
247 sctp_chunk_fail(chunk, q->error);
248 sctp_chunk_free(chunk);
249 }
250
251 /* Throw away any chunks in the retransmit queue. */
252 list_for_each_safe(lchunk, temp, &q->retransmit) {
253 list_del_init(lchunk);
254 chunk = list_entry(lchunk, struct sctp_chunk,
255 transmitted_list);
256 sctp_chunk_fail(chunk, q->error);
257 sctp_chunk_free(chunk);
258 }
259
260 /* Throw away any chunks that are in the abandoned queue. */
261 list_for_each_safe(lchunk, temp, &q->abandoned) {
262 list_del_init(lchunk);
263 chunk = list_entry(lchunk, struct sctp_chunk,
264 transmitted_list);
265 sctp_chunk_fail(chunk, q->error);
266 sctp_chunk_free(chunk);
267 }
268
269 /* Throw away any leftover data chunks. */
270 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
271
272 /* Mark as send failure. */
273 sctp_chunk_fail(chunk, q->error);
274 sctp_chunk_free(chunk);
275 }
276
277 q->error = 0;
278
279 /* Throw away any leftover control chunks. */
David S. Miller79af02c2005-07-08 21:47:49 -0700280 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
281 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -0700283 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284}
285
286/* Free the outqueue structure and any related pending chunks. */
287void sctp_outq_free(struct sctp_outq *q)
288{
289 /* Throw away leftover chunks. */
290 sctp_outq_teardown(q);
291
292 /* If we were kmalloc()'d, free the memory. */
293 if (q->malloced)
294 kfree(q);
295}
296
297/* Put a new chunk in an sctp_outq. */
298int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
299{
300 int error = 0;
301
302 SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
303 q, chunk, chunk && chunk->chunk_hdr ?
304 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
305 : "Illegal Chunk");
306
307 /* If it is data, queue it up, otherwise, send it
308 * immediately.
309 */
310 if (SCTP_CID_DATA == chunk->chunk_hdr->type) {
311 /* Is it OK to queue data chunks? */
312 /* From 9. Termination of Association
313 *
314 * When either endpoint performs a shutdown, the
315 * association on each peer will stop accepting new
316 * data from its user and only deliver data in queue
317 * at the time of sending or receiving the SHUTDOWN
318 * chunk.
319 */
320 switch (q->asoc->state) {
321 case SCTP_STATE_EMPTY:
322 case SCTP_STATE_CLOSED:
323 case SCTP_STATE_SHUTDOWN_PENDING:
324 case SCTP_STATE_SHUTDOWN_SENT:
325 case SCTP_STATE_SHUTDOWN_RECEIVED:
326 case SCTP_STATE_SHUTDOWN_ACK_SENT:
327 /* Cannot send after transport endpoint shutdown */
328 error = -ESHUTDOWN;
329 break;
330
331 default:
332 SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
333 q, chunk, chunk && chunk->chunk_hdr ?
334 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
335 : "Illegal Chunk");
336
337 sctp_outq_tail_data(q, chunk);
338 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
339 SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS);
340 else
341 SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS);
342 q->empty = 0;
343 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700344 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 } else {
David S. Miller79af02c2005-07-08 21:47:49 -0700346 list_add_tail(&chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
348 }
349
350 if (error < 0)
351 return error;
352
353 if (!q->cork)
354 error = sctp_outq_flush(q, 0);
355
356 return error;
357}
358
359/* Insert a chunk into the sorted list based on the TSNs. The retransmit list
360 * and the abandoned list are in ascending order.
361 */
362static void sctp_insert_list(struct list_head *head, struct list_head *new)
363{
364 struct list_head *pos;
365 struct sctp_chunk *nchunk, *lchunk;
366 __u32 ntsn, ltsn;
367 int done = 0;
368
369 nchunk = list_entry(new, struct sctp_chunk, transmitted_list);
370 ntsn = ntohl(nchunk->subh.data_hdr->tsn);
371
372 list_for_each(pos, head) {
373 lchunk = list_entry(pos, struct sctp_chunk, transmitted_list);
374 ltsn = ntohl(lchunk->subh.data_hdr->tsn);
375 if (TSN_lt(ntsn, ltsn)) {
376 list_add(new, pos->prev);
377 done = 1;
378 break;
379 }
380 }
381 if (!done)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900382 list_add_tail(new, head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383}
384
385/* Mark all the eligible packets on a transport for retransmission. */
386void sctp_retransmit_mark(struct sctp_outq *q,
387 struct sctp_transport *transport,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400388 __u8 reason)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389{
390 struct list_head *lchunk, *ltemp;
391 struct sctp_chunk *chunk;
392
393 /* Walk through the specified transmitted queue. */
394 list_for_each_safe(lchunk, ltemp, &transport->transmitted) {
395 chunk = list_entry(lchunk, struct sctp_chunk,
396 transmitted_list);
397
398 /* If the chunk is abandoned, move it to abandoned list. */
399 if (sctp_chunk_abandoned(chunk)) {
400 list_del_init(lchunk);
401 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800402
403 /* If this chunk has not been previousely acked,
404 * stop considering it 'outstanding'. Our peer
405 * will most likely never see it since it will
406 * not be retransmitted
407 */
408 if (!chunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400409 if (chunk->transport)
410 chunk->transport->flight_size -=
411 sctp_data_size(chunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -0800412 q->outstanding_bytes -= sctp_data_size(chunk);
413 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
414 sizeof(struct sk_buff));
415 }
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 */
Sridhar Samudralacd497882006-09-29 17:09:05 -0700434 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
435 sizeof(struct sk_buff));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 q->outstanding_bytes -= sctp_data_size(chunk);
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400437 if (chunk->transport)
438 transport->flight_size -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
440 /* sctpimpguide-05 Section 2.8.2
441 * M5) If a T3-rtx timer expires, the
442 * 'TSN.Missing.Report' of all affected TSNs is set
443 * to 0.
444 */
445 chunk->tsn_missing_report = 0;
446
447 /* If a chunk that is being used for RTT measurement
448 * has to be retransmitted, we cannot use this chunk
449 * anymore for RTT measurements. Reset rto_pending so
450 * that a new RTT measurement is started when a new
451 * data chunk is sent.
452 */
453 if (chunk->rtt_in_progress) {
454 chunk->rtt_in_progress = 0;
455 transport->rto_pending = 0;
456 }
457
458 /* Move the chunk to the retransmit queue. The chunks
459 * on the retransmit queue are always kept in order.
460 */
461 list_del_init(lchunk);
462 sctp_insert_list(&q->retransmit, lchunk);
463 }
464 }
465
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400466 SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 "cwnd: %d, ssthresh: %d, flight_size: %d, "
Harvey Harrison0dc47872008-03-05 20:47:47 -0800468 "pba: %d\n", __func__,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400469 transport, reason,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 transport->cwnd, transport->ssthresh,
471 transport->flight_size,
472 transport->partial_bytes_acked);
473
474}
475
476/* Mark all the eligible packets on a transport for retransmission and force
477 * one packet out.
478 */
479void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
480 sctp_retransmit_reason_t reason)
481{
482 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
484 switch(reason) {
485 case SCTP_RTXR_T3_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700486 SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
488 /* Update the retran path if the T3-rtx timer has expired for
489 * the current retran path.
490 */
491 if (transport == transport->asoc->peer.retran_path)
492 sctp_assoc_update_retran_path(transport->asoc);
Neil Horman58fbbed2008-02-29 11:40:56 -0800493 transport->asoc->rtx_data_chunks +=
494 transport->asoc->unack_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 break;
496 case SCTP_RTXR_FAST_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700497 SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700499 q->fast_rtx = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 break;
501 case SCTP_RTXR_PMTUD:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700502 SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 break;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400504 case SCTP_RTXR_T1_RTX:
505 SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS);
Neil Horman58fbbed2008-02-29 11:40:56 -0800506 transport->asoc->init_retries++;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400507 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700508 default:
509 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 }
511
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400512 sctp_retransmit_mark(q, transport, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513
514 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
515 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
516 * following the procedures outlined in C1 - C5.
517 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700518 if (reason == SCTP_RTXR_T3_RTX)
519 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700521 /* Flush the queues only on timeout, since fast_rtx is only
522 * triggered during sack processing and the queue
523 * will be flushed at the end.
524 */
525 if (reason != SCTP_RTXR_FAST_RTX)
526 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
528 if (error)
529 q->asoc->base.sk->sk_err = -error;
530}
531
532/*
533 * Transmit DATA chunks on the retransmit queue. Upon return from
534 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
535 * need to be transmitted by the caller.
536 * We assume that pkt->transport has already been set.
537 *
538 * The return value is a normal kernel error return value.
539 */
540static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
541 int rtx_timeout, int *start_timer)
542{
543 struct list_head *lqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 struct sctp_transport *transport = pkt->transport;
545 sctp_xmit_t status;
546 struct sctp_chunk *chunk, *chunk1;
547 struct sctp_association *asoc;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700548 int fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 int error = 0;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700550 int timer = 0;
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700551 int done = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552
553 asoc = q->asoc;
554 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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581
582 /* Make sure that Gap Acked TSNs are not retransmitted. A
583 * simple approach is just to move such TSNs out of the
584 * way and into a 'transmitted' queue and skip to the
585 * next chunk.
586 */
587 if (chunk->tsn_gap_acked) {
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700588 list_del(&chunk->transmitted_list);
589 list_add_tail(&chunk->transmitted_list,
590 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 continue;
592 }
593
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700594 /* If we are doing fast retransmit, ignore non-fast_rtransmit
595 * chunks
596 */
597 if (fast_rtx && !chunk->fast_retransmit)
598 continue;
599
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 /* Attempt to append this chunk to the packet. */
601 status = sctp_packet_append_chunk(pkt, chunk);
602
603 switch (status) {
604 case SCTP_XMIT_PMTU_FULL:
605 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700606 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
608 /* If we are retransmitting, we should only
609 * send a single packet.
610 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700611 if (rtx_timeout || fast_rtx)
612 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700614 /* Bundle next chunk in the next round. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 break;
616
617 case SCTP_XMIT_RWND_FULL:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900618 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700619 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620
621 /* Stop sending DATA as there is no more room
622 * at the receiver.
623 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700624 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 break;
626
627 case SCTP_XMIT_NAGLE_DELAY:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900628 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700629 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
631 /* Stop sending DATA because of nagle delay. */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700632 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 break;
634
635 default:
636 /* The append was successful, so add this chunk to
637 * the transmitted list.
638 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700639 list_del(&chunk->transmitted_list);
640 list_add_tail(&chunk->transmitted_list,
641 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900643 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 * after it is retransmitted.
645 */
Neil Hormanc226ef92008-07-25 12:44:09 -0400646 if (chunk->fast_retransmit == SCTP_NEED_FRTX)
647 chunk->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700649 /* Force start T3-rtx timer when fast retransmitting
650 * the earliest outstanding TSN
651 */
652 if (!timer && fast_rtx &&
653 ntohl(chunk->subh.data_hdr->tsn) ==
654 asoc->ctsn_ack_point + 1)
655 timer = 2;
656
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 q->empty = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700659 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700661 /* Set the timer if there were no errors */
662 if (!error && !timer)
663 timer = 1;
664
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700665 if (done)
666 break;
667 }
668
669 /* If we are here due to a retransmit timeout or a fast
670 * retransmit and if there are any chunks left in the retransmit
671 * queue that could not fit in the PMTU sized packet, they need
672 * to be marked as ineligible for a subsequent fast retransmit.
673 */
674 if (rtx_timeout || fast_rtx) {
675 list_for_each_entry(chunk1, lqueue, transmitted_list) {
Neil Hormanc226ef92008-07-25 12:44:09 -0400676 if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
677 chunk1->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 }
679 }
680
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700681 *start_timer = timer;
682
683 /* Clear fast retransmit hint */
684 if (fast_rtx)
685 q->fast_rtx = 0;
686
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 return error;
688}
689
690/* Cork the outqueue so queued chunks are really queued. */
691int sctp_outq_uncork(struct sctp_outq *q)
692{
693 int error = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500694 if (q->cork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 q->cork = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500696 error = sctp_outq_flush(q, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 return error;
698}
699
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701/*
702 * Try to flush an outqueue.
703 *
704 * Description: Send everything in q which we legally can, subject to
705 * congestion limitations.
706 * * Note: This function can be called from multiple contexts so appropriate
707 * locking concerns must be made. Today we use the sock lock to protect
708 * this function.
709 */
Adrian Bunkabd0b1982008-07-22 14:20:45 -0700710static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711{
712 struct sctp_packet *packet;
713 struct sctp_packet singleton;
714 struct sctp_association *asoc = q->asoc;
715 __u16 sport = asoc->base.bind_addr.port;
716 __u16 dport = asoc->peer.port;
717 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 struct sctp_transport *transport = NULL;
719 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700720 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 sctp_xmit_t status;
722 int error = 0;
723 int start_timer = 0;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700724 int one_packet = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
726 /* These transports have chunks to send. */
727 struct list_head transport_list;
728 struct list_head *ltransport;
729
730 INIT_LIST_HEAD(&transport_list);
731 packet = NULL;
732
733 /*
734 * 6.10 Bundling
735 * ...
736 * When bundling control chunks with DATA chunks, an
737 * endpoint MUST place control chunks first in the outbound
738 * SCTP packet. The transmitter MUST transmit DATA chunks
739 * within a SCTP packet in increasing order of TSN.
740 * ...
741 */
742
David S. Miller79af02c2005-07-08 21:47:49 -0700743 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
744 list_del_init(&chunk->list);
745
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 /* Pick the right transport to use. */
747 new_transport = chunk->transport;
748
749 if (!new_transport) {
Vlad Yasevicha08de642007-12-20 14:11:47 -0800750 /*
751 * If we have a prior transport pointer, see if
752 * the destination address of the chunk
753 * matches the destination address of the
754 * current transport. If not a match, then
755 * try to look up the transport with a given
756 * destination address. We do this because
757 * after processing ASCONFs, we may have new
758 * transports created.
759 */
760 if (transport &&
761 sctp_cmp_addr_exact(&chunk->dest,
762 &transport->ipaddr))
763 new_transport = transport;
764 else
765 new_transport = sctp_assoc_lookup_paddr(asoc,
766 &chunk->dest);
767
768 /* if we still don't have a new transport, then
769 * use the current active path.
770 */
771 if (!new_transport)
772 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700773 } else if ((new_transport->state == SCTP_INACTIVE) ||
774 (new_transport->state == SCTP_UNCONFIRMED)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700775 /* If the chunk is Heartbeat or Heartbeat Ack,
776 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 * inactive.
778 *
779 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900780 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 * A HEARTBEAT ACK is always sent to the source IP
782 * address of the IP datagram containing the
783 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900784 * ...
Vlad Yasevicha08de642007-12-20 14:11:47 -0800785 *
786 * ASCONF_ACKs also must be sent to the source.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 */
788 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
Vlad Yasevicha08de642007-12-20 14:11:47 -0800789 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
790 chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 new_transport = asoc->peer.active_path;
792 }
793
794 /* Are we switching transports?
795 * Take care of transport locks.
796 */
797 if (new_transport != transport) {
798 transport = new_transport;
799 if (list_empty(&transport->send_ready)) {
800 list_add_tail(&transport->send_ready,
801 &transport_list);
802 }
803 packet = &transport->packet;
804 sctp_packet_config(packet, vtag,
805 asoc->peer.ecn_capable);
806 }
807
808 switch (chunk->chunk_hdr->type) {
809 /*
810 * 6.10 Bundling
811 * ...
812 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
813 * COMPLETE with any other chunks. [Send them immediately.]
814 */
815 case SCTP_CID_INIT:
816 case SCTP_CID_INIT_ACK:
817 case SCTP_CID_SHUTDOWN_COMPLETE:
818 sctp_packet_init(&singleton, transport, sport, dport);
819 sctp_packet_config(&singleton, vtag, 0);
820 sctp_packet_append_chunk(&singleton, chunk);
821 error = sctp_packet_transmit(&singleton);
822 if (error < 0)
823 return error;
824 break;
825
826 case SCTP_CID_ABORT:
Gui Jianfengf4ad85c2008-04-12 18:39:34 -0700827 if (sctp_test_T_bit(chunk)) {
828 packet->vtag = asoc->c.my_vtag;
829 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700830 /* The following chunks are "response" chunks, i.e.
831 * they are generated in response to something we
832 * received. If we are sending these, then we can
833 * send only 1 packet containing these chunks.
834 */
835 case SCTP_CID_HEARTBEAT_ACK:
836 case SCTP_CID_SHUTDOWN_ACK:
837 case SCTP_CID_COOKIE_ACK:
838 case SCTP_CID_COOKIE_ECHO:
839 case SCTP_CID_ERROR:
840 case SCTP_CID_ECN_CWR:
841 case SCTP_CID_ASCONF_ACK:
842 one_packet = 1;
843 /* Fall throught */
844
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 case SCTP_CID_SACK:
846 case SCTP_CID_HEARTBEAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 case SCTP_CID_SHUTDOWN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 case SCTP_CID_ECN_ECNE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 case SCTP_CID_ASCONF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 case SCTP_CID_FWD_TSN:
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700851 status = sctp_packet_transmit_chunk(packet, chunk,
852 one_packet);
853 if (status != SCTP_XMIT_OK) {
854 /* put the chunk back */
855 list_add(&chunk->list, &q->control_chunk_list);
856 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 break;
858
859 default:
860 /* We built a chunk with an illegal type! */
861 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700862 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 }
864
865 /* Is it OK to send data chunks? */
866 switch (asoc->state) {
867 case SCTP_STATE_COOKIE_ECHOED:
868 /* Only allow bundling when this packet has a COOKIE-ECHO
869 * chunk.
870 */
871 if (!packet || !packet->has_cookie_echo)
872 break;
873
874 /* fallthru */
875 case SCTP_STATE_ESTABLISHED:
876 case SCTP_STATE_SHUTDOWN_PENDING:
877 case SCTP_STATE_SHUTDOWN_RECEIVED:
878 /*
879 * RFC 2960 6.1 Transmission of DATA Chunks
880 *
881 * C) When the time comes for the sender to transmit,
882 * before sending new DATA chunks, the sender MUST
883 * first transmit any outstanding DATA chunks which
884 * are marked for retransmission (limited by the
885 * current cwnd).
886 */
887 if (!list_empty(&q->retransmit)) {
888 if (transport == asoc->peer.retran_path)
889 goto retran;
890
891 /* Switch transports & prepare the packet. */
892
893 transport = asoc->peer.retran_path;
894
895 if (list_empty(&transport->send_ready)) {
896 list_add_tail(&transport->send_ready,
897 &transport_list);
898 }
899
900 packet = &transport->packet;
901 sctp_packet_config(packet, vtag,
902 asoc->peer.ecn_capable);
903 retran:
904 error = sctp_outq_flush_rtx(q, packet,
905 rtx_timeout, &start_timer);
906
907 if (start_timer)
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700908 sctp_transport_reset_timers(transport,
909 start_timer-1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
911 /* This can happen on COOKIE-ECHO resend. Only
912 * one chunk can get bundled with a COOKIE-ECHO.
913 */
914 if (packet->has_cookie_echo)
915 goto sctp_flush_out;
916
917 /* Don't send new data if there is still data
918 * waiting to retransmit.
919 */
920 if (!list_empty(&q->retransmit))
921 goto sctp_flush_out;
922 }
923
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500924 /* Apply Max.Burst limitation to the current transport in
925 * case it will be used for new data. We are going to
926 * rest it before we return, but we want to apply the limit
927 * to the currently queued data.
928 */
929 if (transport)
930 sctp_transport_burst_limited(transport);
931
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 /* Finally, transmit new packets. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
934 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
935 * stream identifier.
936 */
937 if (chunk->sinfo.sinfo_stream >=
938 asoc->c.sinit_num_ostreams) {
939
940 /* Mark as failed send. */
941 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
942 sctp_chunk_free(chunk);
943 continue;
944 }
945
946 /* Has this chunk expired? */
947 if (sctp_chunk_abandoned(chunk)) {
948 sctp_chunk_fail(chunk, 0);
949 sctp_chunk_free(chunk);
950 continue;
951 }
952
953 /* If there is a specified transport, use it.
954 * Otherwise, we want to use the active path.
955 */
956 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700957 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700958 ((new_transport->state == SCTP_INACTIVE) ||
959 (new_transport->state == SCTP_UNCONFIRMED)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 new_transport = asoc->peer.active_path;
961
962 /* Change packets if necessary. */
963 if (new_transport != transport) {
964 transport = new_transport;
965
966 /* Schedule to have this transport's
967 * packet flushed.
968 */
969 if (list_empty(&transport->send_ready)) {
970 list_add_tail(&transport->send_ready,
971 &transport_list);
972 }
973
974 packet = &transport->packet;
975 sctp_packet_config(packet, vtag,
976 asoc->peer.ecn_capable);
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500977 /* We've switched transports, so apply the
978 * Burst limit to the new transport.
979 */
980 sctp_transport_burst_limited(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 }
982
983 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
984 q, chunk,
985 chunk && chunk->chunk_hdr ?
986 sctp_cname(SCTP_ST_CHUNK(
987 chunk->chunk_hdr->type))
988 : "Illegal Chunk");
989
990 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
991 "%p skb->users %d.\n",
992 ntohl(chunk->subh.data_hdr->tsn),
993 chunk->skb ?chunk->skb->head : NULL,
994 chunk->skb ?
995 atomic_read(&chunk->skb->users) : -1);
996
997 /* Add the chunk to the packet. */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700998 status = sctp_packet_transmit_chunk(packet, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999
1000 switch (status) {
1001 case SCTP_XMIT_PMTU_FULL:
1002 case SCTP_XMIT_RWND_FULL:
1003 case SCTP_XMIT_NAGLE_DELAY:
1004 /* We could not append this chunk, so put
1005 * the chunk back on the output queue.
1006 */
1007 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
1008 "not transmit TSN: 0x%x, status: %d\n",
1009 ntohl(chunk->subh.data_hdr->tsn),
1010 status);
1011 sctp_outq_head_data(q, chunk);
1012 goto sctp_flush_out;
1013 break;
1014
1015 case SCTP_XMIT_OK:
Wei Yongjunb93d6472009-11-23 15:53:56 -05001016 /* The sender is in the SHUTDOWN-PENDING state,
1017 * The sender MAY set the I-bit in the DATA
1018 * chunk header.
1019 */
1020 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
1021 chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
1022
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 break;
1024
1025 default:
1026 BUG();
1027 }
1028
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001029 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 * call below will succeed all the time and add the
1031 * chunk to the transmitted list and restart the
1032 * timers.
1033 * It is possible that the call can fail under OOM
1034 * conditions.
1035 *
1036 * Is this really a problem? Won't this behave
1037 * like a lost TSN?
1038 */
1039 list_add_tail(&chunk->transmitted_list,
1040 &transport->transmitted);
1041
Vlad Yasevich6574df92009-01-22 14:52:43 -08001042 sctp_transport_reset_timers(transport, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043
1044 q->empty = 0;
1045
1046 /* Only let one DATA chunk get bundled with a
1047 * COOKIE-ECHO chunk.
1048 */
1049 if (packet->has_cookie_echo)
1050 goto sctp_flush_out;
1051 }
1052 break;
1053
1054 default:
1055 /* Do nothing. */
1056 break;
1057 }
1058
1059sctp_flush_out:
1060
1061 /* Before returning, examine all the transports touched in
1062 * this call. Right now, we bluntly force clear all the
1063 * transports. Things might change after we implement Nagle.
1064 * But such an examination is still required.
1065 *
1066 * --xguo
1067 */
1068 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
1069 struct sctp_transport *t = list_entry(ltransport,
1070 struct sctp_transport,
1071 send_ready);
1072 packet = &t->packet;
1073 if (!sctp_packet_empty(packet))
1074 error = sctp_packet_transmit(packet);
Vlad Yasevich46d5a802009-11-23 15:54:00 -05001075
1076 /* Clear the burst limited state, if any */
1077 sctp_transport_burst_reset(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078 }
1079
1080 return error;
1081}
1082
1083/* Update unack_data based on the incoming SACK chunk */
1084static void sctp_sack_update_unack_data(struct sctp_association *assoc,
1085 struct sctp_sackhdr *sack)
1086{
1087 sctp_sack_variable_t *frags;
1088 __u16 unack_data;
1089 int i;
1090
1091 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
1092
1093 frags = sack->variable;
1094 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1095 unack_data -= ((ntohs(frags[i].gab.end) -
1096 ntohs(frags[i].gab.start) + 1));
1097 }
1098
1099 assoc->unack_data = unack_data;
1100}
1101
1102/* Return the highest new tsn that is acknowledged by the given SACK chunk. */
1103static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack,
1104 struct sctp_association *asoc)
1105{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 struct sctp_transport *transport;
1107 struct sctp_chunk *chunk;
1108 __u32 highest_new_tsn, tsn;
1109 struct list_head *transport_list = &asoc->peer.transport_addr_list;
1110
1111 highest_new_tsn = ntohl(sack->cum_tsn_ack);
1112
Robert P. J. Day9dbc15f02008-04-12 18:54:24 -07001113 list_for_each_entry(transport, transport_list, transports) {
1114 list_for_each_entry(chunk, &transport->transmitted,
1115 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 tsn = ntohl(chunk->subh.data_hdr->tsn);
1117
1118 if (!chunk->tsn_gap_acked &&
1119 TSN_lt(highest_new_tsn, tsn) &&
1120 sctp_acked(sack, tsn))
1121 highest_new_tsn = tsn;
1122 }
1123 }
1124
1125 return highest_new_tsn;
1126}
1127
1128/* This is where we REALLY process a SACK.
1129 *
1130 * Process the SACK against the outqueue. Mostly, this just frees
1131 * things off the transmitted queue.
1132 */
1133int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
1134{
1135 struct sctp_association *asoc = q->asoc;
1136 struct sctp_transport *transport;
1137 struct sctp_chunk *tchunk = NULL;
Robert P. J. Day9dbc15f02008-04-12 18:54:24 -07001138 struct list_head *lchunk, *transport_list, *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 sctp_sack_variable_t *frags = sack->variable;
1140 __u32 sack_ctsn, ctsn, tsn;
1141 __u32 highest_tsn, highest_new_tsn;
1142 __u32 sack_a_rwnd;
1143 unsigned outstanding;
1144 struct sctp_transport *primary = asoc->peer.primary_path;
1145 int count_of_newacks = 0;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001146 int gap_ack_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147
1148 /* Grab the association's destination address list. */
1149 transport_list = &asoc->peer.transport_addr_list;
1150
1151 sack_ctsn = ntohl(sack->cum_tsn_ack);
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001152 gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 /*
1154 * SFR-CACC algorithm:
1155 * On receipt of a SACK the sender SHOULD execute the
1156 * following statements.
1157 *
1158 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1159 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1160 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1161 * all destinations.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1163 * is set the receiver of the SACK MUST take the following actions:
1164 *
1165 * A) Initialize the cacc_saw_newack to 0 for all destination
1166 * addresses.
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001167 *
1168 * Only bother if changeover_active is set. Otherwise, this is
1169 * totally suboptimal to do on every SACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 */
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001171 if (primary->cacc.changeover_active) {
1172 u8 clear_cycling = 0;
1173
1174 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1175 primary->cacc.changeover_active = 0;
1176 clear_cycling = 1;
1177 }
1178
1179 if (clear_cycling || gap_ack_blocks) {
1180 list_for_each_entry(transport, transport_list,
1181 transports) {
1182 if (clear_cycling)
1183 transport->cacc.cycling_changeover = 0;
1184 if (gap_ack_blocks)
1185 transport->cacc.cacc_saw_newack = 0;
1186 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 }
1188 }
1189
1190 /* Get the highest TSN in the sack. */
1191 highest_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001192 if (gap_ack_blocks)
1193 highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194
1195 if (TSN_lt(asoc->highest_sacked, highest_tsn)) {
1196 highest_new_tsn = highest_tsn;
1197 asoc->highest_sacked = highest_tsn;
1198 } else {
1199 highest_new_tsn = sctp_highest_new_tsn(sack, asoc);
1200 }
1201
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001202
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 /* Run through the retransmit queue. Credit bytes received
1204 * and free those chunks that we can.
1205 */
1206 sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207
1208 /* Run through the transmitted queue.
1209 * Credit bytes received and free those chunks which we can.
1210 *
1211 * This is a MASSIVE candidate for optimization.
1212 */
Robert P. J. Day9dbc15f02008-04-12 18:54:24 -07001213 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 sctp_check_transmitted(q, &transport->transmitted,
1215 transport, sack, highest_new_tsn);
1216 /*
1217 * SFR-CACC algorithm:
1218 * C) Let count_of_newacks be the number of
1219 * destinations for which cacc_saw_newack is set.
1220 */
1221 if (transport->cacc.cacc_saw_newack)
1222 count_of_newacks ++;
1223 }
1224
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001225 if (gap_ack_blocks) {
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001226 list_for_each_entry(transport, transport_list, transports)
1227 sctp_mark_missing(q, &transport->transmitted, transport,
1228 highest_new_tsn, count_of_newacks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 }
1230
1231 /* Move the Cumulative TSN Ack Point if appropriate. */
1232 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn))
1233 asoc->ctsn_ack_point = sack_ctsn;
1234
1235 /* Update unack_data field in the assoc. */
1236 sctp_sack_update_unack_data(asoc, sack);
1237
1238 ctsn = asoc->ctsn_ack_point;
1239
1240 /* Throw away stuff rotting on the sack queue. */
1241 list_for_each_safe(lchunk, temp, &q->sacked) {
1242 tchunk = list_entry(lchunk, struct sctp_chunk,
1243 transmitted_list);
1244 tsn = ntohl(tchunk->subh.data_hdr->tsn);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001245 if (TSN_lte(tsn, ctsn)) {
1246 list_del_init(&tchunk->transmitted_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 sctp_chunk_free(tchunk);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001248 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249 }
1250
1251 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1252 * number of bytes still outstanding after processing the
1253 * Cumulative TSN Ack and the Gap Ack Blocks.
1254 */
1255
1256 sack_a_rwnd = ntohl(sack->a_rwnd);
1257 outstanding = q->outstanding_bytes;
1258
1259 if (outstanding < sack_a_rwnd)
1260 sack_a_rwnd -= outstanding;
1261 else
1262 sack_a_rwnd = 0;
1263
1264 asoc->peer.rwnd = sack_a_rwnd;
1265
1266 sctp_generate_fwdtsn(q, sack_ctsn);
1267
1268 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001269 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1271 "%p is 0x%x. Adv peer ack point: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001272 __func__, asoc, ctsn, asoc->adv_peer_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001273
1274 /* See if all chunks are acked.
1275 * Make sure the empty queue handler will get run later.
1276 */
David S. Miller79af02c2005-07-08 21:47:49 -07001277 q->empty = (list_empty(&q->out_chunk_list) &&
David S. Miller79af02c2005-07-08 21:47:49 -07001278 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 if (!q->empty)
1280 goto finish;
1281
Robert P. J. Day9dbc15f02008-04-12 18:54:24 -07001282 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 q->empty = q->empty && list_empty(&transport->transmitted);
1284 if (!q->empty)
1285 goto finish;
1286 }
1287
1288 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1289finish:
1290 return q->empty;
1291}
1292
1293/* Is the outqueue empty? */
1294int sctp_outq_is_empty(const struct sctp_outq *q)
1295{
1296 return q->empty;
1297}
1298
1299/********************************************************************
1300 * 2nd Level Abstractions
1301 ********************************************************************/
1302
1303/* Go through a transport's transmitted list or the association's retransmit
1304 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1305 * The retransmit list will not have an associated transport.
1306 *
1307 * I added coherent debug information output. --xguo
1308 *
1309 * Instead of printing 'sacked' or 'kept' for each TSN on the
1310 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1311 * KEPT TSN6-TSN7, etc.
1312 */
1313static void sctp_check_transmitted(struct sctp_outq *q,
1314 struct list_head *transmitted_queue,
1315 struct sctp_transport *transport,
1316 struct sctp_sackhdr *sack,
1317 __u32 highest_new_tsn_in_sack)
1318{
1319 struct list_head *lchunk;
1320 struct sctp_chunk *tchunk;
1321 struct list_head tlist;
1322 __u32 tsn;
1323 __u32 sack_ctsn;
1324 __u32 rtt;
1325 __u8 restart_timer = 0;
1326 int bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001327 int migrate_bytes = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328
1329 /* These state variables are for coherent debug output. --xguo */
1330
1331#if SCTP_DEBUG
1332 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1333 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1334 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1335 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1336
1337 /* 0 : The last TSN was ACKed.
1338 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1339 * -1: We need to initialize.
1340 */
1341 int dbg_prt_state = -1;
1342#endif /* SCTP_DEBUG */
1343
1344 sack_ctsn = ntohl(sack->cum_tsn_ack);
1345
1346 INIT_LIST_HEAD(&tlist);
1347
1348 /* The while loop will skip empty transmitted queues. */
1349 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1350 tchunk = list_entry(lchunk, struct sctp_chunk,
1351 transmitted_list);
1352
1353 if (sctp_chunk_abandoned(tchunk)) {
1354 /* Move the chunk to abandoned list. */
1355 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001356
1357 /* If this chunk has not been acked, stop
1358 * considering it as 'outstanding'.
1359 */
1360 if (!tchunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001361 if (tchunk->transport)
1362 tchunk->transport->flight_size -=
1363 sctp_data_size(tchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001364 q->outstanding_bytes -= sctp_data_size(tchunk);
1365 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366 continue;
1367 }
1368
1369 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1370 if (sctp_acked(sack, tsn)) {
1371 /* If this queue is the retransmit queue, the
1372 * retransmit timer has already reclaimed
1373 * the outstanding bytes for this chunk, so only
1374 * count bytes associated with a transport.
1375 */
1376 if (transport) {
1377 /* If this chunk is being used for RTT
1378 * measurement, calculate the RTT and update
1379 * the RTO using this value.
1380 *
1381 * 6.3.1 C5) Karn's algorithm: RTT measurements
1382 * MUST NOT be made using packets that were
1383 * retransmitted (and thus for which it is
1384 * ambiguous whether the reply was for the
1385 * first instance of the packet or a later
1386 * instance).
1387 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001388 if (!tchunk->tsn_gap_acked &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 !tchunk->resent &&
1390 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001391 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 rtt = jiffies - tchunk->sent_at;
1393 sctp_transport_update_rto(transport,
1394 rtt);
1395 }
1396 }
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001397
1398 /* If the chunk hasn't been marked as ACKED,
1399 * mark it and account bytes_acked if the
1400 * chunk had a valid transport (it will not
1401 * have a transport if ASCONF had deleted it
1402 * while DATA was outstanding).
1403 */
1404 if (!tchunk->tsn_gap_acked) {
1405 tchunk->tsn_gap_acked = 1;
1406 bytes_acked += sctp_data_size(tchunk);
1407 if (!tchunk->transport)
1408 migrate_bytes += sctp_data_size(tchunk);
1409 }
1410
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001411 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 /* RFC 2960 6.3.2 Retransmission Timer Rules
1413 *
1414 * R3) Whenever a SACK is received
1415 * that acknowledges the DATA chunk
1416 * with the earliest outstanding TSN
1417 * for that address, restart T3-rtx
1418 * timer for that address with its
1419 * current RTO.
1420 */
1421 restart_timer = 1;
1422
1423 if (!tchunk->tsn_gap_acked) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424 /*
1425 * SFR-CACC algorithm:
1426 * 2) If the SACK contains gap acks
1427 * and the flag CHANGEOVER_ACTIVE is
1428 * set the receiver of the SACK MUST
1429 * take the following action:
1430 *
1431 * B) For each TSN t being acked that
1432 * has not been acked in any SACK so
1433 * far, set cacc_saw_newack to 1 for
1434 * the destination that the TSN was
1435 * sent to.
1436 */
1437 if (transport &&
1438 sack->num_gap_ack_blocks &&
1439 q->asoc->peer.primary_path->cacc.
1440 changeover_active)
1441 transport->cacc.cacc_saw_newack
1442 = 1;
1443 }
1444
1445 list_add_tail(&tchunk->transmitted_list,
1446 &q->sacked);
1447 } else {
1448 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1449 * M2) Each time a SACK arrives reporting
1450 * 'Stray DATA chunk(s)' record the highest TSN
1451 * reported as newly acknowledged, call this
1452 * value 'HighestTSNinSack'. A newly
1453 * acknowledged DATA chunk is one not
1454 * previously acknowledged in a SACK.
1455 *
1456 * When the SCTP sender of data receives a SACK
1457 * chunk that acknowledges, for the first time,
1458 * the receipt of a DATA chunk, all the still
1459 * unacknowledged DATA chunks whose TSN is
1460 * older than that newly acknowledged DATA
1461 * chunk, are qualified as 'Stray DATA chunks'.
1462 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 list_add_tail(lchunk, &tlist);
1464 }
1465
1466#if SCTP_DEBUG
1467 switch (dbg_prt_state) {
1468 case 0: /* last TSN was ACKed */
1469 if (dbg_last_ack_tsn + 1 == tsn) {
1470 /* This TSN belongs to the
1471 * current ACK range.
1472 */
1473 break;
1474 }
1475
1476 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1477 /* Display the end of the
1478 * current range.
1479 */
1480 SCTP_DEBUG_PRINTK("-%08x",
1481 dbg_last_ack_tsn);
1482 }
1483
1484 /* Start a new range. */
1485 SCTP_DEBUG_PRINTK(",%08x", tsn);
1486 dbg_ack_tsn = tsn;
1487 break;
1488
1489 case 1: /* The last TSN was NOT ACKed. */
1490 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1491 /* Display the end of current range. */
1492 SCTP_DEBUG_PRINTK("-%08x",
1493 dbg_last_kept_tsn);
1494 }
1495
1496 SCTP_DEBUG_PRINTK("\n");
1497
1498 /* FALL THROUGH... */
1499 default:
1500 /* This is the first-ever TSN we examined. */
1501 /* Start a new range of ACK-ed TSNs. */
1502 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1503 dbg_prt_state = 0;
1504 dbg_ack_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001505 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506
1507 dbg_last_ack_tsn = tsn;
1508#endif /* SCTP_DEBUG */
1509
1510 } else {
1511 if (tchunk->tsn_gap_acked) {
1512 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1513 "data TSN: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001514 __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515 tsn);
1516 tchunk->tsn_gap_acked = 0;
1517
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001518 if (tchunk->transport)
1519 bytes_acked -= sctp_data_size(tchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001520
1521 /* RFC 2960 6.3.2 Retransmission Timer Rules
1522 *
1523 * R4) Whenever a SACK is received missing a
1524 * TSN that was previously acknowledged via a
1525 * Gap Ack Block, start T3-rtx for the
1526 * destination address to which the DATA
1527 * chunk was originally
1528 * transmitted if it is not already running.
1529 */
1530 restart_timer = 1;
1531 }
1532
1533 list_add_tail(lchunk, &tlist);
1534
1535#if SCTP_DEBUG
1536 /* See the above comments on ACK-ed TSNs. */
1537 switch (dbg_prt_state) {
1538 case 1:
1539 if (dbg_last_kept_tsn + 1 == tsn)
1540 break;
1541
1542 if (dbg_last_kept_tsn != dbg_kept_tsn)
1543 SCTP_DEBUG_PRINTK("-%08x",
1544 dbg_last_kept_tsn);
1545
1546 SCTP_DEBUG_PRINTK(",%08x", tsn);
1547 dbg_kept_tsn = tsn;
1548 break;
1549
1550 case 0:
1551 if (dbg_last_ack_tsn != dbg_ack_tsn)
1552 SCTP_DEBUG_PRINTK("-%08x",
1553 dbg_last_ack_tsn);
1554 SCTP_DEBUG_PRINTK("\n");
1555
1556 /* FALL THROUGH... */
1557 default:
1558 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1559 dbg_prt_state = 1;
1560 dbg_kept_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001561 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562
1563 dbg_last_kept_tsn = tsn;
1564#endif /* SCTP_DEBUG */
1565 }
1566 }
1567
1568#if SCTP_DEBUG
1569 /* Finish off the last range, displaying its ending TSN. */
1570 switch (dbg_prt_state) {
1571 case 0:
1572 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1573 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn);
1574 } else {
1575 SCTP_DEBUG_PRINTK("\n");
1576 }
1577 break;
1578
1579 case 1:
1580 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1581 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn);
1582 } else {
1583 SCTP_DEBUG_PRINTK("\n");
1584 }
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001585 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586#endif /* SCTP_DEBUG */
1587 if (transport) {
1588 if (bytes_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001589 /* We may have counted DATA that was migrated
1590 * to this transport due to DEL-IP operation.
1591 * Subtract those bytes, since the were never
1592 * send on this transport and shouldn't be
1593 * credited to this transport.
1594 */
1595 bytes_acked -= migrate_bytes;
1596
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 /* 8.2. When an outstanding TSN is acknowledged,
1598 * the endpoint shall clear the error counter of
1599 * the destination transport address to which the
1600 * DATA chunk was last sent.
1601 * The association's overall error counter is
1602 * also cleared.
1603 */
1604 transport->error_count = 0;
1605 transport->asoc->overall_error_count = 0;
1606
1607 /* Mark the destination transport address as
1608 * active if it is not so marked.
1609 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001610 if ((transport->state == SCTP_INACTIVE) ||
1611 (transport->state == SCTP_UNCONFIRMED)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 sctp_assoc_control_transport(
1613 transport->asoc,
1614 transport,
1615 SCTP_TRANSPORT_UP,
1616 SCTP_RECEIVED_SACK);
1617 }
1618
1619 sctp_transport_raise_cwnd(transport, sack_ctsn,
1620 bytes_acked);
1621
1622 transport->flight_size -= bytes_acked;
Gui Jianfeng8b73a072008-04-17 14:22:18 -07001623 if (transport->flight_size == 0)
1624 transport->partial_bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001625 q->outstanding_bytes -= bytes_acked + migrate_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001626 } else {
1627 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1628 * When a sender is doing zero window probing, it
1629 * should not timeout the association if it continues
1630 * to receive new packets from the receiver. The
1631 * reason is that the receiver MAY keep its window
1632 * closed for an indefinite time.
1633 * A sender is doing zero window probing when the
1634 * receiver's advertised window is zero, and there is
1635 * only one data chunk in flight to the receiver.
1636 */
1637 if (!q->asoc->peer.rwnd &&
1638 !list_empty(&tlist) &&
1639 (sack_ctsn+2 == q->asoc->next_tsn)) {
1640 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1641 "window probe: %u\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001642 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 q->asoc->overall_error_count = 0;
1644 transport->error_count = 0;
1645 }
1646 }
1647
1648 /* RFC 2960 6.3.2 Retransmission Timer Rules
1649 *
1650 * R2) Whenever all outstanding data sent to an address have
1651 * been acknowledged, turn off the T3-rtx timer of that
1652 * address.
1653 */
1654 if (!transport->flight_size) {
1655 if (timer_pending(&transport->T3_rtx_timer) &&
1656 del_timer(&transport->T3_rtx_timer)) {
1657 sctp_transport_put(transport);
1658 }
1659 } else if (restart_timer) {
1660 if (!mod_timer(&transport->T3_rtx_timer,
1661 jiffies + transport->rto))
1662 sctp_transport_hold(transport);
1663 }
1664 }
1665
1666 list_splice(&tlist, transmitted_queue);
1667}
1668
1669/* Mark chunks as missing and consequently may get retransmitted. */
1670static void sctp_mark_missing(struct sctp_outq *q,
1671 struct list_head *transmitted_queue,
1672 struct sctp_transport *transport,
1673 __u32 highest_new_tsn_in_sack,
1674 int count_of_newacks)
1675{
1676 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677 __u32 tsn;
1678 char do_fast_retransmit = 0;
1679 struct sctp_transport *primary = q->asoc->peer.primary_path;
1680
Robert P. J. Day9dbc15f02008-04-12 18:54:24 -07001681 list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 tsn = ntohl(chunk->subh.data_hdr->tsn);
1684
1685 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1686 * 'Unacknowledged TSN's', if the TSN number of an
1687 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1688 * value, increment the 'TSN.Missing.Report' count on that
1689 * chunk if it has NOT been fast retransmitted or marked for
1690 * fast retransmit already.
1691 */
Neil Hormanc226ef92008-07-25 12:44:09 -04001692 if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001693 !chunk->tsn_gap_acked &&
1694 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1695
1696 /* SFR-CACC may require us to skip marking
1697 * this chunk as missing.
1698 */
1699 if (!transport || !sctp_cacc_skip(primary, transport,
1700 count_of_newacks, tsn)) {
1701 chunk->tsn_missing_report++;
1702
1703 SCTP_DEBUG_PRINTK(
1704 "%s: TSN 0x%x missing counter: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001705 __func__, tsn,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 chunk->tsn_missing_report);
1707 }
1708 }
1709 /*
1710 * M4) If any DATA chunk is found to have a
1711 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001712 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001713 * retransmission and start the fast retransmit procedure.
1714 */
1715
Vlad Yasevich27852c22006-02-02 16:57:31 -08001716 if (chunk->tsn_missing_report >= 3) {
Neil Hormanc226ef92008-07-25 12:44:09 -04001717 chunk->fast_retransmit = SCTP_NEED_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 do_fast_retransmit = 1;
1719 }
1720 }
1721
1722 if (transport) {
1723 if (do_fast_retransmit)
1724 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1725
1726 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1727 "ssthresh: %d, flight_size: %d, pba: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001728 __func__, transport, transport->cwnd,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001729 transport->ssthresh, transport->flight_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730 transport->partial_bytes_acked);
1731 }
1732}
1733
1734/* Is the given TSN acked by this packet? */
1735static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1736{
1737 int i;
1738 sctp_sack_variable_t *frags;
1739 __u16 gap;
1740 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1741
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001742 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001743 goto pass;
1744
1745 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1746 *
1747 * Gap Ack Blocks:
1748 * These fields contain the Gap Ack Blocks. They are repeated
1749 * for each Gap Ack Block up to the number of Gap Ack Blocks
1750 * defined in the Number of Gap Ack Blocks field. All DATA
1751 * chunks with TSNs greater than or equal to (Cumulative TSN
1752 * Ack + Gap Ack Block Start) and less than or equal to
1753 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1754 * Block are assumed to have been received correctly.
1755 */
1756
1757 frags = sack->variable;
1758 gap = tsn - ctsn;
1759 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1760 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1761 TSN_lte(gap, ntohs(frags[i].gab.end)))
1762 goto pass;
1763 }
1764
1765 return 0;
1766pass:
1767 return 1;
1768}
1769
1770static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001771 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772{
1773 int i;
1774
1775 for (i = 0; i < nskips; i++) {
1776 if (skiplist[i].stream == stream)
1777 return i;
1778 }
1779 return i;
1780}
1781
1782/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1783static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1784{
1785 struct sctp_association *asoc = q->asoc;
1786 struct sctp_chunk *ftsn_chunk = NULL;
1787 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1788 int nskips = 0;
1789 int skip_pos = 0;
1790 __u32 tsn;
1791 struct sctp_chunk *chunk;
1792 struct list_head *lchunk, *temp;
1793
Wei Yongjun76595022009-03-12 09:49:19 +00001794 if (!asoc->peer.prsctp_capable)
1795 return;
1796
Linus Torvalds1da177e2005-04-16 15:20:36 -07001797 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1798 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001799 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1801 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1802 */
1803 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1804 asoc->adv_peer_ack_point = ctsn;
1805
1806 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1807 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1808 * the chunk next in the out-queue space is marked as "abandoned" as
1809 * shown in the following example:
1810 *
1811 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1812 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001813 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1815 * normal SACK processing local advancement
1816 * ... ...
1817 * Adv.Ack.Pt-> 102 acked 102 acked
1818 * 103 abandoned 103 abandoned
1819 * 104 abandoned Adv.Ack.P-> 104 abandoned
1820 * 105 105
1821 * 106 acked 106 acked
1822 * ... ...
1823 *
1824 * In this example, the data sender successfully advanced the
1825 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1826 */
1827 list_for_each_safe(lchunk, temp, &q->abandoned) {
1828 chunk = list_entry(lchunk, struct sctp_chunk,
1829 transmitted_list);
1830 tsn = ntohl(chunk->subh.data_hdr->tsn);
1831
1832 /* Remove any chunks in the abandoned queue that are acked by
1833 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001834 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835 if (TSN_lte(tsn, ctsn)) {
1836 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001837 sctp_chunk_free(chunk);
1838 } else {
1839 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1840 asoc->adv_peer_ack_point = tsn;
1841 if (chunk->chunk_hdr->flags &
1842 SCTP_DATA_UNORDERED)
1843 continue;
1844 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1845 nskips,
1846 chunk->subh.data_hdr->stream);
1847 ftsn_skip_arr[skip_pos].stream =
1848 chunk->subh.data_hdr->stream;
1849 ftsn_skip_arr[skip_pos].ssn =
1850 chunk->subh.data_hdr->ssn;
1851 if (skip_pos == nskips)
1852 nskips++;
1853 if (nskips == 10)
1854 break;
1855 } else
1856 break;
1857 }
1858 }
1859
1860 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1861 * is greater than the Cumulative TSN ACK carried in the received
1862 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1863 * chunk containing the latest value of the
1864 * "Advanced.Peer.Ack.Point".
1865 *
1866 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1867 * list each stream and sequence number in the forwarded TSN. This
1868 * information will enable the receiver to easily find any
1869 * stranded TSN's waiting on stream reorder queues. Each stream
1870 * SHOULD only be reported once; this means that if multiple
1871 * abandoned messages occur in the same stream then only the
1872 * highest abandoned stream sequence number is reported. If the
1873 * total size of the FORWARD TSN does NOT fit in a single MTU then
1874 * the sender of the FORWARD TSN SHOULD lower the
1875 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1876 * single MTU.
1877 */
1878 if (asoc->adv_peer_ack_point > ctsn)
1879 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001880 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001881
1882 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001883 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001884 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1885 }
1886}