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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 &&
194 (sctp_cacc_skip_3_1(primary, transport, count_of_newacks)
195 || sctp_cacc_skip_3_2(primary, tsn)))
196 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. Day9dbc15f2008-04-12 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. Day9dbc15f2008-04-12 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)) {
Vlad Yasevichd0ce9292007-08-24 19:37:46 +0900426 /* If this chunk was sent less then 1 rto ago, do not
427 * retransmit this chunk, but give the peer time
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400428 * to acknowlege it. Do this only when
429 * retransmitting due to T3 timeout.
Vlad Yasevichd0ce9292007-08-24 19:37:46 +0900430 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400431 if (reason == SCTP_RTXR_T3_RTX &&
Wei Yongjunf61f6f82009-03-02 09:46:13 +0000432 time_before(jiffies, chunk->sent_at +
433 transport->last_rto))
Vlad Yasevichd0ce9292007-08-24 19:37:46 +0900434 continue;
435
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 /* RFC 2960 6.2.1 Processing a Received SACK
437 *
438 * C) Any time a DATA chunk is marked for
439 * retransmission (via either T3-rtx timer expiration
440 * (Section 6.3.3) or via fast retransmit
441 * (Section 7.2.4)), add the data size of those
442 * chunks to the rwnd.
443 */
Sridhar Samudralacd497882006-09-29 17:09:05 -0700444 q->asoc->peer.rwnd += (sctp_data_size(chunk) +
445 sizeof(struct sk_buff));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 q->outstanding_bytes -= sctp_data_size(chunk);
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400447 if (chunk->transport)
448 transport->flight_size -= sctp_data_size(chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
450 /* sctpimpguide-05 Section 2.8.2
451 * M5) If a T3-rtx timer expires, the
452 * 'TSN.Missing.Report' of all affected TSNs is set
453 * to 0.
454 */
455 chunk->tsn_missing_report = 0;
456
457 /* If a chunk that is being used for RTT measurement
458 * has to be retransmitted, we cannot use this chunk
459 * anymore for RTT measurements. Reset rto_pending so
460 * that a new RTT measurement is started when a new
461 * data chunk is sent.
462 */
463 if (chunk->rtt_in_progress) {
464 chunk->rtt_in_progress = 0;
465 transport->rto_pending = 0;
466 }
467
468 /* Move the chunk to the retransmit queue. The chunks
469 * on the retransmit queue are always kept in order.
470 */
471 list_del_init(lchunk);
472 sctp_insert_list(&q->retransmit, lchunk);
473 }
474 }
475
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400476 SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 "cwnd: %d, ssthresh: %d, flight_size: %d, "
Harvey Harrison0dc47872008-03-05 20:47:47 -0800478 "pba: %d\n", __func__,
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400479 transport, reason,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 transport->cwnd, transport->ssthresh,
481 transport->flight_size,
482 transport->partial_bytes_acked);
483
484}
485
486/* Mark all the eligible packets on a transport for retransmission and force
487 * one packet out.
488 */
489void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
490 sctp_retransmit_reason_t reason)
491{
492 int error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
494 switch(reason) {
495 case SCTP_RTXR_T3_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700496 SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
498 /* Update the retran path if the T3-rtx timer has expired for
499 * the current retran path.
500 */
501 if (transport == transport->asoc->peer.retran_path)
502 sctp_assoc_update_retran_path(transport->asoc);
Neil Horman58fbbed2008-02-29 11:40:56 -0800503 transport->asoc->rtx_data_chunks +=
504 transport->asoc->unack_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 break;
506 case SCTP_RTXR_FAST_RTX:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700507 SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700509 q->fast_rtx = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 break;
511 case SCTP_RTXR_PMTUD:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700512 SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 break;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400514 case SCTP_RTXR_T1_RTX:
515 SCTP_INC_STATS(SCTP_MIB_T1_RETRANSMITS);
Neil Horman58fbbed2008-02-29 11:40:56 -0800516 transport->asoc->init_retries++;
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400517 break;
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700518 default:
519 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 }
521
Vlad Yasevichb6157d82007-10-24 15:59:16 -0400522 sctp_retransmit_mark(q, transport, reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523
524 /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination,
525 * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by
526 * following the procedures outlined in C1 - C5.
527 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700528 if (reason == SCTP_RTXR_T3_RTX)
529 sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700531 /* Flush the queues only on timeout, since fast_rtx is only
532 * triggered during sack processing and the queue
533 * will be flushed at the end.
534 */
535 if (reason != SCTP_RTXR_FAST_RTX)
536 error = sctp_outq_flush(q, /* rtx_timeout */ 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
538 if (error)
539 q->asoc->base.sk->sk_err = -error;
540}
541
542/*
543 * Transmit DATA chunks on the retransmit queue. Upon return from
544 * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
545 * need to be transmitted by the caller.
546 * We assume that pkt->transport has already been set.
547 *
548 * The return value is a normal kernel error return value.
549 */
550static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
551 int rtx_timeout, int *start_timer)
552{
553 struct list_head *lqueue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 struct sctp_transport *transport = pkt->transport;
555 sctp_xmit_t status;
556 struct sctp_chunk *chunk, *chunk1;
557 struct sctp_association *asoc;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700558 int fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 int error = 0;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700560 int timer = 0;
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700561 int done = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
563 asoc = q->asoc;
564 lqueue = &q->retransmit;
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700565 fast_rtx = q->fast_rtx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700567 /* This loop handles time-out retransmissions, fast retransmissions,
568 * and retransmissions due to opening of whindow.
569 *
570 * RFC 2960 6.3.3 Handle T3-rtx Expiration
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 *
572 * E3) Determine how many of the earliest (i.e., lowest TSN)
573 * outstanding DATA chunks for the address for which the
574 * T3-rtx has expired will fit into a single packet, subject
575 * to the MTU constraint for the path corresponding to the
576 * destination transport address to which the retransmission
577 * is being sent (this may be different from the address for
578 * which the timer expires [see Section 6.4]). Call this value
579 * K. Bundle and retransmit those K DATA chunks in a single
580 * packet to the destination endpoint.
581 *
582 * [Just to be painfully clear, if we are retransmitting
583 * because a timeout just happened, we should send only ONE
584 * packet of retransmitted data.]
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700585 *
586 * For fast retransmissions we also send only ONE packet. However,
587 * if we are just flushing the queue due to open window, we'll
588 * try to send as much as possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700590 list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591
592 /* Make sure that Gap Acked TSNs are not retransmitted. A
593 * simple approach is just to move such TSNs out of the
594 * way and into a 'transmitted' queue and skip to the
595 * next chunk.
596 */
597 if (chunk->tsn_gap_acked) {
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700598 list_del(&chunk->transmitted_list);
599 list_add_tail(&chunk->transmitted_list,
600 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 continue;
602 }
603
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700604 /* If we are doing fast retransmit, ignore non-fast_rtransmit
605 * chunks
606 */
607 if (fast_rtx && !chunk->fast_retransmit)
608 continue;
609
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 /* Attempt to append this chunk to the packet. */
611 status = sctp_packet_append_chunk(pkt, chunk);
612
613 switch (status) {
614 case SCTP_XMIT_PMTU_FULL:
615 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700616 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
618 /* If we are retransmitting, we should only
619 * send a single packet.
620 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700621 if (rtx_timeout || fast_rtx)
622 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700624 /* Bundle next chunk in the next round. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 break;
626
627 case SCTP_XMIT_RWND_FULL:
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 as there is no more room
632 * at the receiver.
633 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700634 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 break;
636
637 case SCTP_XMIT_NAGLE_DELAY:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900638 /* Send this packet. */
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700639 error = sctp_packet_transmit(pkt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640
641 /* Stop sending DATA because of nagle delay. */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700642 done = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 break;
644
645 default:
646 /* The append was successful, so add this chunk to
647 * the transmitted list.
648 */
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700649 list_del(&chunk->transmitted_list);
650 list_add_tail(&chunk->transmitted_list,
651 &transport->transmitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900653 /* Mark the chunk as ineligible for fast retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 * after it is retransmitted.
655 */
Neil Hormanc226ef92008-07-25 12:44:09 -0400656 if (chunk->fast_retransmit == SCTP_NEED_FRTX)
657 chunk->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700659 /* Force start T3-rtx timer when fast retransmitting
660 * the earliest outstanding TSN
661 */
662 if (!timer && fast_rtx &&
663 ntohl(chunk->subh.data_hdr->tsn) ==
664 asoc->ctsn_ack_point + 1)
665 timer = 2;
666
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 q->empty = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700669 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700671 /* Set the timer if there were no errors */
672 if (!error && !timer)
673 timer = 1;
674
Vlad Yasevich8b750ce2008-06-04 12:39:36 -0700675 if (done)
676 break;
677 }
678
679 /* If we are here due to a retransmit timeout or a fast
680 * retransmit and if there are any chunks left in the retransmit
681 * queue that could not fit in the PMTU sized packet, they need
682 * to be marked as ineligible for a subsequent fast retransmit.
683 */
684 if (rtx_timeout || fast_rtx) {
685 list_for_each_entry(chunk1, lqueue, transmitted_list) {
Neil Hormanc226ef92008-07-25 12:44:09 -0400686 if (chunk1->fast_retransmit == SCTP_NEED_FRTX)
687 chunk1->fast_retransmit = SCTP_DONT_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 }
689 }
690
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700691 *start_timer = timer;
692
693 /* Clear fast retransmit hint */
694 if (fast_rtx)
695 q->fast_rtx = 0;
696
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 return error;
698}
699
700/* Cork the outqueue so queued chunks are really queued. */
701int sctp_outq_uncork(struct sctp_outq *q)
702{
703 int error = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500704 if (q->cork)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 q->cork = 0;
Vlad Yasevich7d54dc62007-11-09 11:43:41 -0500706 error = sctp_outq_flush(q, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 return error;
708}
709
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700710
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711/*
712 * Try to flush an outqueue.
713 *
714 * Description: Send everything in q which we legally can, subject to
715 * congestion limitations.
716 * * Note: This function can be called from multiple contexts so appropriate
717 * locking concerns must be made. Today we use the sock lock to protect
718 * this function.
719 */
Adrian Bunkabd0b1982008-07-22 14:20:45 -0700720static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721{
722 struct sctp_packet *packet;
723 struct sctp_packet singleton;
724 struct sctp_association *asoc = q->asoc;
725 __u16 sport = asoc->base.bind_addr.port;
726 __u16 dport = asoc->peer.port;
727 __u32 vtag = asoc->peer.i.init_tag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 struct sctp_transport *transport = NULL;
729 struct sctp_transport *new_transport;
David S. Miller79af02c2005-07-08 21:47:49 -0700730 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 sctp_xmit_t status;
732 int error = 0;
733 int start_timer = 0;
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700734 int one_packet = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735
736 /* These transports have chunks to send. */
737 struct list_head transport_list;
738 struct list_head *ltransport;
739
740 INIT_LIST_HEAD(&transport_list);
741 packet = NULL;
742
743 /*
744 * 6.10 Bundling
745 * ...
746 * When bundling control chunks with DATA chunks, an
747 * endpoint MUST place control chunks first in the outbound
748 * SCTP packet. The transmitter MUST transmit DATA chunks
749 * within a SCTP packet in increasing order of TSN.
750 * ...
751 */
752
David S. Miller79af02c2005-07-08 21:47:49 -0700753 list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
754 list_del_init(&chunk->list);
755
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 /* Pick the right transport to use. */
757 new_transport = chunk->transport;
758
759 if (!new_transport) {
Vlad Yasevicha08de642007-12-20 14:11:47 -0800760 /*
761 * If we have a prior transport pointer, see if
762 * the destination address of the chunk
763 * matches the destination address of the
764 * current transport. If not a match, then
765 * try to look up the transport with a given
766 * destination address. We do this because
767 * after processing ASCONFs, we may have new
768 * transports created.
769 */
770 if (transport &&
771 sctp_cmp_addr_exact(&chunk->dest,
772 &transport->ipaddr))
773 new_transport = transport;
774 else
775 new_transport = sctp_assoc_lookup_paddr(asoc,
776 &chunk->dest);
777
778 /* if we still don't have a new transport, then
779 * use the current active path.
780 */
781 if (!new_transport)
782 new_transport = asoc->peer.active_path;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700783 } else if ((new_transport->state == SCTP_INACTIVE) ||
784 (new_transport->state == SCTP_UNCONFIRMED)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700785 /* If the chunk is Heartbeat or Heartbeat Ack,
786 * send it to chunk->transport, even if it's
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 * inactive.
788 *
789 * 3.3.6 Heartbeat Acknowledgement:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900790 * ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 * A HEARTBEAT ACK is always sent to the source IP
792 * address of the IP datagram containing the
793 * HEARTBEAT chunk to which this ack is responding.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900794 * ...
Vlad Yasevicha08de642007-12-20 14:11:47 -0800795 *
796 * ASCONF_ACKs also must be sent to the source.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 */
798 if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
Vlad Yasevicha08de642007-12-20 14:11:47 -0800799 chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
800 chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 new_transport = asoc->peer.active_path;
802 }
803
804 /* Are we switching transports?
805 * Take care of transport locks.
806 */
807 if (new_transport != transport) {
808 transport = new_transport;
809 if (list_empty(&transport->send_ready)) {
810 list_add_tail(&transport->send_ready,
811 &transport_list);
812 }
813 packet = &transport->packet;
814 sctp_packet_config(packet, vtag,
815 asoc->peer.ecn_capable);
816 }
817
818 switch (chunk->chunk_hdr->type) {
819 /*
820 * 6.10 Bundling
821 * ...
822 * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN
823 * COMPLETE with any other chunks. [Send them immediately.]
824 */
825 case SCTP_CID_INIT:
826 case SCTP_CID_INIT_ACK:
827 case SCTP_CID_SHUTDOWN_COMPLETE:
828 sctp_packet_init(&singleton, transport, sport, dport);
829 sctp_packet_config(&singleton, vtag, 0);
830 sctp_packet_append_chunk(&singleton, chunk);
831 error = sctp_packet_transmit(&singleton);
832 if (error < 0)
833 return error;
834 break;
835
836 case SCTP_CID_ABORT:
Gui Jianfengf4ad85c2008-04-12 18:39:34 -0700837 if (sctp_test_T_bit(chunk)) {
838 packet->vtag = asoc->c.my_vtag;
839 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700840 /* The following chunks are "response" chunks, i.e.
841 * they are generated in response to something we
842 * received. If we are sending these, then we can
843 * send only 1 packet containing these chunks.
844 */
845 case SCTP_CID_HEARTBEAT_ACK:
846 case SCTP_CID_SHUTDOWN_ACK:
847 case SCTP_CID_COOKIE_ACK:
848 case SCTP_CID_COOKIE_ECHO:
849 case SCTP_CID_ERROR:
850 case SCTP_CID_ECN_CWR:
851 case SCTP_CID_ASCONF_ACK:
852 one_packet = 1;
853 /* Fall throught */
854
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 case SCTP_CID_SACK:
856 case SCTP_CID_HEARTBEAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 case SCTP_CID_SHUTDOWN:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 case SCTP_CID_ECN_ECNE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 case SCTP_CID_ASCONF:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 case SCTP_CID_FWD_TSN:
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700861 status = sctp_packet_transmit_chunk(packet, chunk,
862 one_packet);
863 if (status != SCTP_XMIT_OK) {
864 /* put the chunk back */
865 list_add(&chunk->list, &q->control_chunk_list);
866 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 break;
868
869 default:
870 /* We built a chunk with an illegal type! */
871 BUG();
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700872 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 }
874
875 /* Is it OK to send data chunks? */
876 switch (asoc->state) {
877 case SCTP_STATE_COOKIE_ECHOED:
878 /* Only allow bundling when this packet has a COOKIE-ECHO
879 * chunk.
880 */
881 if (!packet || !packet->has_cookie_echo)
882 break;
883
884 /* fallthru */
885 case SCTP_STATE_ESTABLISHED:
886 case SCTP_STATE_SHUTDOWN_PENDING:
887 case SCTP_STATE_SHUTDOWN_RECEIVED:
888 /*
889 * RFC 2960 6.1 Transmission of DATA Chunks
890 *
891 * C) When the time comes for the sender to transmit,
892 * before sending new DATA chunks, the sender MUST
893 * first transmit any outstanding DATA chunks which
894 * are marked for retransmission (limited by the
895 * current cwnd).
896 */
897 if (!list_empty(&q->retransmit)) {
898 if (transport == asoc->peer.retran_path)
899 goto retran;
900
901 /* Switch transports & prepare the packet. */
902
903 transport = asoc->peer.retran_path;
904
905 if (list_empty(&transport->send_ready)) {
906 list_add_tail(&transport->send_ready,
907 &transport_list);
908 }
909
910 packet = &transport->packet;
911 sctp_packet_config(packet, vtag,
912 asoc->peer.ecn_capable);
913 retran:
914 error = sctp_outq_flush_rtx(q, packet,
915 rtx_timeout, &start_timer);
916
917 if (start_timer)
Vlad Yasevich62aeaff2008-06-04 12:39:11 -0700918 sctp_transport_reset_timers(transport,
919 start_timer-1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920
921 /* This can happen on COOKIE-ECHO resend. Only
922 * one chunk can get bundled with a COOKIE-ECHO.
923 */
924 if (packet->has_cookie_echo)
925 goto sctp_flush_out;
926
927 /* Don't send new data if there is still data
928 * waiting to retransmit.
929 */
930 if (!list_empty(&q->retransmit))
931 goto sctp_flush_out;
932 }
933
934 /* Finally, transmit new packets. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
936 /* RFC 2960 6.5 Every DATA chunk MUST carry a valid
937 * stream identifier.
938 */
939 if (chunk->sinfo.sinfo_stream >=
940 asoc->c.sinit_num_ostreams) {
941
942 /* Mark as failed send. */
943 sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM);
944 sctp_chunk_free(chunk);
945 continue;
946 }
947
948 /* Has this chunk expired? */
949 if (sctp_chunk_abandoned(chunk)) {
950 sctp_chunk_fail(chunk, 0);
951 sctp_chunk_free(chunk);
952 continue;
953 }
954
955 /* If there is a specified transport, use it.
956 * Otherwise, we want to use the active path.
957 */
958 new_transport = chunk->transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700959 if (!new_transport ||
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700960 ((new_transport->state == SCTP_INACTIVE) ||
961 (new_transport->state == SCTP_UNCONFIRMED)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 new_transport = asoc->peer.active_path;
963
964 /* Change packets if necessary. */
965 if (new_transport != transport) {
966 transport = new_transport;
967
968 /* Schedule to have this transport's
969 * packet flushed.
970 */
971 if (list_empty(&transport->send_ready)) {
972 list_add_tail(&transport->send_ready,
973 &transport_list);
974 }
975
976 packet = &transport->packet;
977 sctp_packet_config(packet, vtag,
978 asoc->peer.ecn_capable);
979 }
980
981 SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
982 q, chunk,
983 chunk && chunk->chunk_hdr ?
984 sctp_cname(SCTP_ST_CHUNK(
985 chunk->chunk_hdr->type))
986 : "Illegal Chunk");
987
988 SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
989 "%p skb->users %d.\n",
990 ntohl(chunk->subh.data_hdr->tsn),
991 chunk->skb ?chunk->skb->head : NULL,
992 chunk->skb ?
993 atomic_read(&chunk->skb->users) : -1);
994
995 /* Add the chunk to the packet. */
Vlad Yasevich2e3216c2008-06-19 16:08:18 -0700996 status = sctp_packet_transmit_chunk(packet, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
998 switch (status) {
999 case SCTP_XMIT_PMTU_FULL:
1000 case SCTP_XMIT_RWND_FULL:
1001 case SCTP_XMIT_NAGLE_DELAY:
1002 /* We could not append this chunk, so put
1003 * the chunk back on the output queue.
1004 */
1005 SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
1006 "not transmit TSN: 0x%x, status: %d\n",
1007 ntohl(chunk->subh.data_hdr->tsn),
1008 status);
1009 sctp_outq_head_data(q, chunk);
1010 goto sctp_flush_out;
1011 break;
1012
1013 case SCTP_XMIT_OK:
1014 break;
1015
1016 default:
1017 BUG();
1018 }
1019
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001020 /* BUG: We assume that the sctp_packet_transmit()
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021 * call below will succeed all the time and add the
1022 * chunk to the transmitted list and restart the
1023 * timers.
1024 * It is possible that the call can fail under OOM
1025 * conditions.
1026 *
1027 * Is this really a problem? Won't this behave
1028 * like a lost TSN?
1029 */
1030 list_add_tail(&chunk->transmitted_list,
1031 &transport->transmitted);
1032
Vlad Yasevich6574df92009-01-22 14:52:43 -08001033 sctp_transport_reset_timers(transport, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034
1035 q->empty = 0;
1036
1037 /* Only let one DATA chunk get bundled with a
1038 * COOKIE-ECHO chunk.
1039 */
1040 if (packet->has_cookie_echo)
1041 goto sctp_flush_out;
1042 }
1043 break;
1044
1045 default:
1046 /* Do nothing. */
1047 break;
1048 }
1049
1050sctp_flush_out:
1051
1052 /* Before returning, examine all the transports touched in
1053 * this call. Right now, we bluntly force clear all the
1054 * transports. Things might change after we implement Nagle.
1055 * But such an examination is still required.
1056 *
1057 * --xguo
1058 */
1059 while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) {
1060 struct sctp_transport *t = list_entry(ltransport,
1061 struct sctp_transport,
1062 send_ready);
1063 packet = &t->packet;
1064 if (!sctp_packet_empty(packet))
1065 error = sctp_packet_transmit(packet);
1066 }
1067
1068 return error;
1069}
1070
1071/* Update unack_data based on the incoming SACK chunk */
1072static void sctp_sack_update_unack_data(struct sctp_association *assoc,
1073 struct sctp_sackhdr *sack)
1074{
1075 sctp_sack_variable_t *frags;
1076 __u16 unack_data;
1077 int i;
1078
1079 unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1;
1080
1081 frags = sack->variable;
1082 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) {
1083 unack_data -= ((ntohs(frags[i].gab.end) -
1084 ntohs(frags[i].gab.start) + 1));
1085 }
1086
1087 assoc->unack_data = unack_data;
1088}
1089
1090/* Return the highest new tsn that is acknowledged by the given SACK chunk. */
1091static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack,
1092 struct sctp_association *asoc)
1093{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 struct sctp_transport *transport;
1095 struct sctp_chunk *chunk;
1096 __u32 highest_new_tsn, tsn;
1097 struct list_head *transport_list = &asoc->peer.transport_addr_list;
1098
1099 highest_new_tsn = ntohl(sack->cum_tsn_ack);
1100
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001101 list_for_each_entry(transport, transport_list, transports) {
1102 list_for_each_entry(chunk, &transport->transmitted,
1103 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104 tsn = ntohl(chunk->subh.data_hdr->tsn);
1105
1106 if (!chunk->tsn_gap_acked &&
1107 TSN_lt(highest_new_tsn, tsn) &&
1108 sctp_acked(sack, tsn))
1109 highest_new_tsn = tsn;
1110 }
1111 }
1112
1113 return highest_new_tsn;
1114}
1115
1116/* This is where we REALLY process a SACK.
1117 *
1118 * Process the SACK against the outqueue. Mostly, this just frees
1119 * things off the transmitted queue.
1120 */
1121int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack)
1122{
1123 struct sctp_association *asoc = q->asoc;
1124 struct sctp_transport *transport;
1125 struct sctp_chunk *tchunk = NULL;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001126 struct list_head *lchunk, *transport_list, *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 sctp_sack_variable_t *frags = sack->variable;
1128 __u32 sack_ctsn, ctsn, tsn;
1129 __u32 highest_tsn, highest_new_tsn;
1130 __u32 sack_a_rwnd;
1131 unsigned outstanding;
1132 struct sctp_transport *primary = asoc->peer.primary_path;
1133 int count_of_newacks = 0;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001134 int gap_ack_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135
1136 /* Grab the association's destination address list. */
1137 transport_list = &asoc->peer.transport_addr_list;
1138
1139 sack_ctsn = ntohl(sack->cum_tsn_ack);
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001140 gap_ack_blocks = ntohs(sack->num_gap_ack_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 /*
1142 * SFR-CACC algorithm:
1143 * On receipt of a SACK the sender SHOULD execute the
1144 * following statements.
1145 *
1146 * 1) If the cumulative ack in the SACK passes next tsn_at_change
1147 * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be
1148 * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for
1149 * all destinations.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE
1151 * is set the receiver of the SACK MUST take the following actions:
1152 *
1153 * A) Initialize the cacc_saw_newack to 0 for all destination
1154 * addresses.
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001155 *
1156 * Only bother if changeover_active is set. Otherwise, this is
1157 * totally suboptimal to do on every SACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 */
Vlad Yasevichab5216a2008-06-19 18:17:24 -04001159 if (primary->cacc.changeover_active) {
1160 u8 clear_cycling = 0;
1161
1162 if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) {
1163 primary->cacc.changeover_active = 0;
1164 clear_cycling = 1;
1165 }
1166
1167 if (clear_cycling || gap_ack_blocks) {
1168 list_for_each_entry(transport, transport_list,
1169 transports) {
1170 if (clear_cycling)
1171 transport->cacc.cycling_changeover = 0;
1172 if (gap_ack_blocks)
1173 transport->cacc.cacc_saw_newack = 0;
1174 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175 }
1176 }
1177
1178 /* Get the highest TSN in the sack. */
1179 highest_tsn = sack_ctsn;
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001180 if (gap_ack_blocks)
1181 highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182
1183 if (TSN_lt(asoc->highest_sacked, highest_tsn)) {
1184 highest_new_tsn = highest_tsn;
1185 asoc->highest_sacked = highest_tsn;
1186 } else {
1187 highest_new_tsn = sctp_highest_new_tsn(sack, asoc);
1188 }
1189
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001190
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 /* Run through the retransmit queue. Credit bytes received
1192 * and free those chunks that we can.
1193 */
1194 sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195
1196 /* Run through the transmitted queue.
1197 * Credit bytes received and free those chunks which we can.
1198 *
1199 * This is a MASSIVE candidate for optimization.
1200 */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001201 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202 sctp_check_transmitted(q, &transport->transmitted,
1203 transport, sack, highest_new_tsn);
1204 /*
1205 * SFR-CACC algorithm:
1206 * C) Let count_of_newacks be the number of
1207 * destinations for which cacc_saw_newack is set.
1208 */
1209 if (transport->cacc.cacc_saw_newack)
1210 count_of_newacks ++;
1211 }
1212
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001213 if (gap_ack_blocks) {
Vlad Yasevich2cd9b822008-06-19 17:59:13 -04001214 list_for_each_entry(transport, transport_list, transports)
1215 sctp_mark_missing(q, &transport->transmitted, transport,
1216 highest_new_tsn, count_of_newacks);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 }
1218
1219 /* Move the Cumulative TSN Ack Point if appropriate. */
1220 if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn))
1221 asoc->ctsn_ack_point = sack_ctsn;
1222
1223 /* Update unack_data field in the assoc. */
1224 sctp_sack_update_unack_data(asoc, sack);
1225
1226 ctsn = asoc->ctsn_ack_point;
1227
1228 /* Throw away stuff rotting on the sack queue. */
1229 list_for_each_safe(lchunk, temp, &q->sacked) {
1230 tchunk = list_entry(lchunk, struct sctp_chunk,
1231 transmitted_list);
1232 tsn = ntohl(tchunk->subh.data_hdr->tsn);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001233 if (TSN_lte(tsn, ctsn)) {
1234 list_del_init(&tchunk->transmitted_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 sctp_chunk_free(tchunk);
Vlad Yasevich5f9646c2008-02-05 14:23:44 -05001236 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237 }
1238
1239 /* ii) Set rwnd equal to the newly received a_rwnd minus the
1240 * number of bytes still outstanding after processing the
1241 * Cumulative TSN Ack and the Gap Ack Blocks.
1242 */
1243
1244 sack_a_rwnd = ntohl(sack->a_rwnd);
1245 outstanding = q->outstanding_bytes;
1246
1247 if (outstanding < sack_a_rwnd)
1248 sack_a_rwnd -= outstanding;
1249 else
1250 sack_a_rwnd = 0;
1251
1252 asoc->peer.rwnd = sack_a_rwnd;
1253
1254 sctp_generate_fwdtsn(q, sack_ctsn);
1255
1256 SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001257 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
1259 "%p is 0x%x. Adv peer ack point: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001260 __func__, asoc, ctsn, asoc->adv_peer_ack_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001261
1262 /* See if all chunks are acked.
1263 * Make sure the empty queue handler will get run later.
1264 */
David S. Miller79af02c2005-07-08 21:47:49 -07001265 q->empty = (list_empty(&q->out_chunk_list) &&
David S. Miller79af02c2005-07-08 21:47:49 -07001266 list_empty(&q->retransmit));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 if (!q->empty)
1268 goto finish;
1269
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001270 list_for_each_entry(transport, transport_list, transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271 q->empty = q->empty && list_empty(&transport->transmitted);
1272 if (!q->empty)
1273 goto finish;
1274 }
1275
1276 SCTP_DEBUG_PRINTK("sack queue is empty.\n");
1277finish:
1278 return q->empty;
1279}
1280
1281/* Is the outqueue empty? */
1282int sctp_outq_is_empty(const struct sctp_outq *q)
1283{
1284 return q->empty;
1285}
1286
1287/********************************************************************
1288 * 2nd Level Abstractions
1289 ********************************************************************/
1290
1291/* Go through a transport's transmitted list or the association's retransmit
1292 * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked.
1293 * The retransmit list will not have an associated transport.
1294 *
1295 * I added coherent debug information output. --xguo
1296 *
1297 * Instead of printing 'sacked' or 'kept' for each TSN on the
1298 * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5.
1299 * KEPT TSN6-TSN7, etc.
1300 */
1301static void sctp_check_transmitted(struct sctp_outq *q,
1302 struct list_head *transmitted_queue,
1303 struct sctp_transport *transport,
1304 struct sctp_sackhdr *sack,
1305 __u32 highest_new_tsn_in_sack)
1306{
1307 struct list_head *lchunk;
1308 struct sctp_chunk *tchunk;
1309 struct list_head tlist;
1310 __u32 tsn;
1311 __u32 sack_ctsn;
1312 __u32 rtt;
1313 __u8 restart_timer = 0;
1314 int bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001315 int migrate_bytes = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316
1317 /* These state variables are for coherent debug output. --xguo */
1318
1319#if SCTP_DEBUG
1320 __u32 dbg_ack_tsn = 0; /* An ACKed TSN range starts here... */
1321 __u32 dbg_last_ack_tsn = 0; /* ...and finishes here. */
1322 __u32 dbg_kept_tsn = 0; /* An un-ACKed range starts here... */
1323 __u32 dbg_last_kept_tsn = 0; /* ...and finishes here. */
1324
1325 /* 0 : The last TSN was ACKed.
1326 * 1 : The last TSN was NOT ACKed (i.e. KEPT).
1327 * -1: We need to initialize.
1328 */
1329 int dbg_prt_state = -1;
1330#endif /* SCTP_DEBUG */
1331
1332 sack_ctsn = ntohl(sack->cum_tsn_ack);
1333
1334 INIT_LIST_HEAD(&tlist);
1335
1336 /* The while loop will skip empty transmitted queues. */
1337 while (NULL != (lchunk = sctp_list_dequeue(transmitted_queue))) {
1338 tchunk = list_entry(lchunk, struct sctp_chunk,
1339 transmitted_list);
1340
1341 if (sctp_chunk_abandoned(tchunk)) {
1342 /* Move the chunk to abandoned list. */
1343 sctp_insert_list(&q->abandoned, lchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001344
1345 /* If this chunk has not been acked, stop
1346 * considering it as 'outstanding'.
1347 */
1348 if (!tchunk->tsn_gap_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001349 if (tchunk->transport)
1350 tchunk->transport->flight_size -=
1351 sctp_data_size(tchunk);
Vlad Yasevich8c4a2d42007-02-21 02:06:04 -08001352 q->outstanding_bytes -= sctp_data_size(tchunk);
1353 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354 continue;
1355 }
1356
1357 tsn = ntohl(tchunk->subh.data_hdr->tsn);
1358 if (sctp_acked(sack, tsn)) {
1359 /* If this queue is the retransmit queue, the
1360 * retransmit timer has already reclaimed
1361 * the outstanding bytes for this chunk, so only
1362 * count bytes associated with a transport.
1363 */
1364 if (transport) {
1365 /* If this chunk is being used for RTT
1366 * measurement, calculate the RTT and update
1367 * the RTO using this value.
1368 *
1369 * 6.3.1 C5) Karn's algorithm: RTT measurements
1370 * MUST NOT be made using packets that were
1371 * retransmitted (and thus for which it is
1372 * ambiguous whether the reply was for the
1373 * first instance of the packet or a later
1374 * instance).
1375 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001376 if (!tchunk->tsn_gap_acked &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 !tchunk->resent &&
1378 tchunk->rtt_in_progress) {
Vlad Yasevich4c9f5d52006-06-17 22:56:08 -07001379 tchunk->rtt_in_progress = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 rtt = jiffies - tchunk->sent_at;
1381 sctp_transport_update_rto(transport,
1382 rtt);
1383 }
1384 }
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001385
1386 /* If the chunk hasn't been marked as ACKED,
1387 * mark it and account bytes_acked if the
1388 * chunk had a valid transport (it will not
1389 * have a transport if ASCONF had deleted it
1390 * while DATA was outstanding).
1391 */
1392 if (!tchunk->tsn_gap_acked) {
1393 tchunk->tsn_gap_acked = 1;
1394 bytes_acked += sctp_data_size(tchunk);
1395 if (!tchunk->transport)
1396 migrate_bytes += sctp_data_size(tchunk);
1397 }
1398
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001399 if (TSN_lte(tsn, sack_ctsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 /* RFC 2960 6.3.2 Retransmission Timer Rules
1401 *
1402 * R3) Whenever a SACK is received
1403 * that acknowledges the DATA chunk
1404 * with the earliest outstanding TSN
1405 * for that address, restart T3-rtx
1406 * timer for that address with its
1407 * current RTO.
1408 */
1409 restart_timer = 1;
1410
1411 if (!tchunk->tsn_gap_acked) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 /*
1413 * SFR-CACC algorithm:
1414 * 2) If the SACK contains gap acks
1415 * and the flag CHANGEOVER_ACTIVE is
1416 * set the receiver of the SACK MUST
1417 * take the following action:
1418 *
1419 * B) For each TSN t being acked that
1420 * has not been acked in any SACK so
1421 * far, set cacc_saw_newack to 1 for
1422 * the destination that the TSN was
1423 * sent to.
1424 */
1425 if (transport &&
1426 sack->num_gap_ack_blocks &&
1427 q->asoc->peer.primary_path->cacc.
1428 changeover_active)
1429 transport->cacc.cacc_saw_newack
1430 = 1;
1431 }
1432
1433 list_add_tail(&tchunk->transmitted_list,
1434 &q->sacked);
1435 } else {
1436 /* RFC2960 7.2.4, sctpimpguide-05 2.8.2
1437 * M2) Each time a SACK arrives reporting
1438 * 'Stray DATA chunk(s)' record the highest TSN
1439 * reported as newly acknowledged, call this
1440 * value 'HighestTSNinSack'. A newly
1441 * acknowledged DATA chunk is one not
1442 * previously acknowledged in a SACK.
1443 *
1444 * When the SCTP sender of data receives a SACK
1445 * chunk that acknowledges, for the first time,
1446 * the receipt of a DATA chunk, all the still
1447 * unacknowledged DATA chunks whose TSN is
1448 * older than that newly acknowledged DATA
1449 * chunk, are qualified as 'Stray DATA chunks'.
1450 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451 list_add_tail(lchunk, &tlist);
1452 }
1453
1454#if SCTP_DEBUG
1455 switch (dbg_prt_state) {
1456 case 0: /* last TSN was ACKed */
1457 if (dbg_last_ack_tsn + 1 == tsn) {
1458 /* This TSN belongs to the
1459 * current ACK range.
1460 */
1461 break;
1462 }
1463
1464 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1465 /* Display the end of the
1466 * current range.
1467 */
1468 SCTP_DEBUG_PRINTK("-%08x",
1469 dbg_last_ack_tsn);
1470 }
1471
1472 /* Start a new range. */
1473 SCTP_DEBUG_PRINTK(",%08x", tsn);
1474 dbg_ack_tsn = tsn;
1475 break;
1476
1477 case 1: /* The last TSN was NOT ACKed. */
1478 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1479 /* Display the end of current range. */
1480 SCTP_DEBUG_PRINTK("-%08x",
1481 dbg_last_kept_tsn);
1482 }
1483
1484 SCTP_DEBUG_PRINTK("\n");
1485
1486 /* FALL THROUGH... */
1487 default:
1488 /* This is the first-ever TSN we examined. */
1489 /* Start a new range of ACK-ed TSNs. */
1490 SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
1491 dbg_prt_state = 0;
1492 dbg_ack_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001493 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494
1495 dbg_last_ack_tsn = tsn;
1496#endif /* SCTP_DEBUG */
1497
1498 } else {
1499 if (tchunk->tsn_gap_acked) {
1500 SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
1501 "data TSN: 0x%x\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001502 __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503 tsn);
1504 tchunk->tsn_gap_acked = 0;
1505
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001506 if (tchunk->transport)
1507 bytes_acked -= sctp_data_size(tchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508
1509 /* RFC 2960 6.3.2 Retransmission Timer Rules
1510 *
1511 * R4) Whenever a SACK is received missing a
1512 * TSN that was previously acknowledged via a
1513 * Gap Ack Block, start T3-rtx for the
1514 * destination address to which the DATA
1515 * chunk was originally
1516 * transmitted if it is not already running.
1517 */
1518 restart_timer = 1;
1519 }
1520
1521 list_add_tail(lchunk, &tlist);
1522
1523#if SCTP_DEBUG
1524 /* See the above comments on ACK-ed TSNs. */
1525 switch (dbg_prt_state) {
1526 case 1:
1527 if (dbg_last_kept_tsn + 1 == tsn)
1528 break;
1529
1530 if (dbg_last_kept_tsn != dbg_kept_tsn)
1531 SCTP_DEBUG_PRINTK("-%08x",
1532 dbg_last_kept_tsn);
1533
1534 SCTP_DEBUG_PRINTK(",%08x", tsn);
1535 dbg_kept_tsn = tsn;
1536 break;
1537
1538 case 0:
1539 if (dbg_last_ack_tsn != dbg_ack_tsn)
1540 SCTP_DEBUG_PRINTK("-%08x",
1541 dbg_last_ack_tsn);
1542 SCTP_DEBUG_PRINTK("\n");
1543
1544 /* FALL THROUGH... */
1545 default:
1546 SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
1547 dbg_prt_state = 1;
1548 dbg_kept_tsn = tsn;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001549 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001550
1551 dbg_last_kept_tsn = tsn;
1552#endif /* SCTP_DEBUG */
1553 }
1554 }
1555
1556#if SCTP_DEBUG
1557 /* Finish off the last range, displaying its ending TSN. */
1558 switch (dbg_prt_state) {
1559 case 0:
1560 if (dbg_last_ack_tsn != dbg_ack_tsn) {
1561 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_ack_tsn);
1562 } else {
1563 SCTP_DEBUG_PRINTK("\n");
1564 }
1565 break;
1566
1567 case 1:
1568 if (dbg_last_kept_tsn != dbg_kept_tsn) {
1569 SCTP_DEBUG_PRINTK("-%08x\n", dbg_last_kept_tsn);
1570 } else {
1571 SCTP_DEBUG_PRINTK("\n");
1572 }
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001573 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574#endif /* SCTP_DEBUG */
1575 if (transport) {
1576 if (bytes_acked) {
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001577 /* We may have counted DATA that was migrated
1578 * to this transport due to DEL-IP operation.
1579 * Subtract those bytes, since the were never
1580 * send on this transport and shouldn't be
1581 * credited to this transport.
1582 */
1583 bytes_acked -= migrate_bytes;
1584
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585 /* 8.2. When an outstanding TSN is acknowledged,
1586 * the endpoint shall clear the error counter of
1587 * the destination transport address to which the
1588 * DATA chunk was last sent.
1589 * The association's overall error counter is
1590 * also cleared.
1591 */
1592 transport->error_count = 0;
1593 transport->asoc->overall_error_count = 0;
1594
1595 /* Mark the destination transport address as
1596 * active if it is not so marked.
1597 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001598 if ((transport->state == SCTP_INACTIVE) ||
1599 (transport->state == SCTP_UNCONFIRMED)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 sctp_assoc_control_transport(
1601 transport->asoc,
1602 transport,
1603 SCTP_TRANSPORT_UP,
1604 SCTP_RECEIVED_SACK);
1605 }
1606
1607 sctp_transport_raise_cwnd(transport, sack_ctsn,
1608 bytes_acked);
1609
1610 transport->flight_size -= bytes_acked;
Gui Jianfeng8b73a072008-04-17 14:22:18 -07001611 if (transport->flight_size == 0)
1612 transport->partial_bytes_acked = 0;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04001613 q->outstanding_bytes -= bytes_acked + migrate_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 } else {
1615 /* RFC 2960 6.1, sctpimpguide-06 2.15.2
1616 * When a sender is doing zero window probing, it
1617 * should not timeout the association if it continues
1618 * to receive new packets from the receiver. The
1619 * reason is that the receiver MAY keep its window
1620 * closed for an indefinite time.
1621 * A sender is doing zero window probing when the
1622 * receiver's advertised window is zero, and there is
1623 * only one data chunk in flight to the receiver.
1624 */
1625 if (!q->asoc->peer.rwnd &&
1626 !list_empty(&tlist) &&
1627 (sack_ctsn+2 == q->asoc->next_tsn)) {
1628 SCTP_DEBUG_PRINTK("%s: SACK received for zero "
1629 "window probe: %u\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001630 __func__, sack_ctsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 q->asoc->overall_error_count = 0;
1632 transport->error_count = 0;
1633 }
1634 }
1635
1636 /* RFC 2960 6.3.2 Retransmission Timer Rules
1637 *
1638 * R2) Whenever all outstanding data sent to an address have
1639 * been acknowledged, turn off the T3-rtx timer of that
1640 * address.
1641 */
1642 if (!transport->flight_size) {
1643 if (timer_pending(&transport->T3_rtx_timer) &&
1644 del_timer(&transport->T3_rtx_timer)) {
1645 sctp_transport_put(transport);
1646 }
1647 } else if (restart_timer) {
1648 if (!mod_timer(&transport->T3_rtx_timer,
1649 jiffies + transport->rto))
1650 sctp_transport_hold(transport);
1651 }
1652 }
1653
1654 list_splice(&tlist, transmitted_queue);
1655}
1656
1657/* Mark chunks as missing and consequently may get retransmitted. */
1658static void sctp_mark_missing(struct sctp_outq *q,
1659 struct list_head *transmitted_queue,
1660 struct sctp_transport *transport,
1661 __u32 highest_new_tsn_in_sack,
1662 int count_of_newacks)
1663{
1664 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665 __u32 tsn;
1666 char do_fast_retransmit = 0;
1667 struct sctp_transport *primary = q->asoc->peer.primary_path;
1668
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001669 list_for_each_entry(chunk, transmitted_queue, transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671 tsn = ntohl(chunk->subh.data_hdr->tsn);
1672
1673 /* RFC 2960 7.2.4, sctpimpguide-05 2.8.2 M3) Examine all
1674 * 'Unacknowledged TSN's', if the TSN number of an
1675 * 'Unacknowledged TSN' is smaller than the 'HighestTSNinSack'
1676 * value, increment the 'TSN.Missing.Report' count on that
1677 * chunk if it has NOT been fast retransmitted or marked for
1678 * fast retransmit already.
1679 */
Neil Hormanc226ef92008-07-25 12:44:09 -04001680 if (chunk->fast_retransmit == SCTP_CAN_FRTX &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681 !chunk->tsn_gap_acked &&
1682 TSN_lt(tsn, highest_new_tsn_in_sack)) {
1683
1684 /* SFR-CACC may require us to skip marking
1685 * this chunk as missing.
1686 */
1687 if (!transport || !sctp_cacc_skip(primary, transport,
1688 count_of_newacks, tsn)) {
1689 chunk->tsn_missing_report++;
1690
1691 SCTP_DEBUG_PRINTK(
1692 "%s: TSN 0x%x missing counter: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001693 __func__, tsn,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 chunk->tsn_missing_report);
1695 }
1696 }
1697 /*
1698 * M4) If any DATA chunk is found to have a
1699 * 'TSN.Missing.Report'
Vlad Yasevich27852c22006-02-02 16:57:31 -08001700 * value larger than or equal to 3, mark that chunk for
Linus Torvalds1da177e2005-04-16 15:20:36 -07001701 * retransmission and start the fast retransmit procedure.
1702 */
1703
Vlad Yasevich27852c22006-02-02 16:57:31 -08001704 if (chunk->tsn_missing_report >= 3) {
Neil Hormanc226ef92008-07-25 12:44:09 -04001705 chunk->fast_retransmit = SCTP_NEED_FRTX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 do_fast_retransmit = 1;
1707 }
1708 }
1709
1710 if (transport) {
1711 if (do_fast_retransmit)
1712 sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
1713
1714 SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
1715 "ssthresh: %d, flight_size: %d, pba: %d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001716 __func__, transport, transport->cwnd,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001717 transport->ssthresh, transport->flight_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718 transport->partial_bytes_acked);
1719 }
1720}
1721
1722/* Is the given TSN acked by this packet? */
1723static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn)
1724{
1725 int i;
1726 sctp_sack_variable_t *frags;
1727 __u16 gap;
1728 __u32 ctsn = ntohl(sack->cum_tsn_ack);
1729
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001730 if (TSN_lte(tsn, ctsn))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731 goto pass;
1732
1733 /* 3.3.4 Selective Acknowledgement (SACK) (3):
1734 *
1735 * Gap Ack Blocks:
1736 * These fields contain the Gap Ack Blocks. They are repeated
1737 * for each Gap Ack Block up to the number of Gap Ack Blocks
1738 * defined in the Number of Gap Ack Blocks field. All DATA
1739 * chunks with TSNs greater than or equal to (Cumulative TSN
1740 * Ack + Gap Ack Block Start) and less than or equal to
1741 * (Cumulative TSN Ack + Gap Ack Block End) of each Gap Ack
1742 * Block are assumed to have been received correctly.
1743 */
1744
1745 frags = sack->variable;
1746 gap = tsn - ctsn;
1747 for (i = 0; i < ntohs(sack->num_gap_ack_blocks); ++i) {
1748 if (TSN_lte(ntohs(frags[i].gab.start), gap) &&
1749 TSN_lte(gap, ntohs(frags[i].gab.end)))
1750 goto pass;
1751 }
1752
1753 return 0;
1754pass:
1755 return 1;
1756}
1757
1758static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist,
Al Viro9f81bcd2006-11-20 17:26:34 -08001759 int nskips, __be16 stream)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760{
1761 int i;
1762
1763 for (i = 0; i < nskips; i++) {
1764 if (skiplist[i].stream == stream)
1765 return i;
1766 }
1767 return i;
1768}
1769
1770/* Create and add a fwdtsn chunk to the outq's control queue if needed. */
1771static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn)
1772{
1773 struct sctp_association *asoc = q->asoc;
1774 struct sctp_chunk *ftsn_chunk = NULL;
1775 struct sctp_fwdtsn_skip ftsn_skip_arr[10];
1776 int nskips = 0;
1777 int skip_pos = 0;
1778 __u32 tsn;
1779 struct sctp_chunk *chunk;
1780 struct list_head *lchunk, *temp;
1781
Wei Yongjun76595022009-03-12 09:49:19 +00001782 if (!asoc->peer.prsctp_capable)
1783 return;
1784
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785 /* PR-SCTP C1) Let SackCumAck be the Cumulative TSN ACK carried in the
1786 * received SACK.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001787 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788 * If (Advanced.Peer.Ack.Point < SackCumAck), then update
1789 * Advanced.Peer.Ack.Point to be equal to SackCumAck.
1790 */
1791 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1792 asoc->adv_peer_ack_point = ctsn;
1793
1794 /* PR-SCTP C2) Try to further advance the "Advanced.Peer.Ack.Point"
1795 * locally, that is, to move "Advanced.Peer.Ack.Point" up as long as
1796 * the chunk next in the out-queue space is marked as "abandoned" as
1797 * shown in the following example:
1798 *
1799 * Assuming that a SACK arrived with the Cumulative TSN ACK 102
1800 * and the Advanced.Peer.Ack.Point is updated to this value:
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001801 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802 * out-queue at the end of ==> out-queue after Adv.Ack.Point
1803 * normal SACK processing local advancement
1804 * ... ...
1805 * Adv.Ack.Pt-> 102 acked 102 acked
1806 * 103 abandoned 103 abandoned
1807 * 104 abandoned Adv.Ack.P-> 104 abandoned
1808 * 105 105
1809 * 106 acked 106 acked
1810 * ... ...
1811 *
1812 * In this example, the data sender successfully advanced the
1813 * "Advanced.Peer.Ack.Point" from 102 to 104 locally.
1814 */
1815 list_for_each_safe(lchunk, temp, &q->abandoned) {
1816 chunk = list_entry(lchunk, struct sctp_chunk,
1817 transmitted_list);
1818 tsn = ntohl(chunk->subh.data_hdr->tsn);
1819
1820 /* Remove any chunks in the abandoned queue that are acked by
1821 * the ctsn.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001822 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001823 if (TSN_lte(tsn, ctsn)) {
1824 list_del_init(lchunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001825 sctp_chunk_free(chunk);
1826 } else {
1827 if (TSN_lte(tsn, asoc->adv_peer_ack_point+1)) {
1828 asoc->adv_peer_ack_point = tsn;
1829 if (chunk->chunk_hdr->flags &
1830 SCTP_DATA_UNORDERED)
1831 continue;
1832 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0],
1833 nskips,
1834 chunk->subh.data_hdr->stream);
1835 ftsn_skip_arr[skip_pos].stream =
1836 chunk->subh.data_hdr->stream;
1837 ftsn_skip_arr[skip_pos].ssn =
1838 chunk->subh.data_hdr->ssn;
1839 if (skip_pos == nskips)
1840 nskips++;
1841 if (nskips == 10)
1842 break;
1843 } else
1844 break;
1845 }
1846 }
1847
1848 /* PR-SCTP C3) If, after step C1 and C2, the "Advanced.Peer.Ack.Point"
1849 * is greater than the Cumulative TSN ACK carried in the received
1850 * SACK, the data sender MUST send the data receiver a FORWARD TSN
1851 * chunk containing the latest value of the
1852 * "Advanced.Peer.Ack.Point".
1853 *
1854 * C4) For each "abandoned" TSN the sender of the FORWARD TSN SHOULD
1855 * list each stream and sequence number in the forwarded TSN. This
1856 * information will enable the receiver to easily find any
1857 * stranded TSN's waiting on stream reorder queues. Each stream
1858 * SHOULD only be reported once; this means that if multiple
1859 * abandoned messages occur in the same stream then only the
1860 * highest abandoned stream sequence number is reported. If the
1861 * total size of the FORWARD TSN does NOT fit in a single MTU then
1862 * the sender of the FORWARD TSN SHOULD lower the
1863 * Advanced.Peer.Ack.Point to the last TSN that will fit in a
1864 * single MTU.
1865 */
1866 if (asoc->adv_peer_ack_point > ctsn)
1867 ftsn_chunk = sctp_make_fwdtsn(asoc, asoc->adv_peer_ack_point,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001868 nskips, &ftsn_skip_arr[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001869
1870 if (ftsn_chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -07001871 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1873 }
1874}